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Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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1

Silica Geothermometers | Open Energy Information  

Open Energy Info (EERE)

Silica Geothermometers Silica Geothermometers Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Silica Geothermometers Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: Geochemical Data Analysis Parent Exploration Technique: Liquid Geothermometry Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Used to estimate reservoir temperatures. Dictionary.png Silica Geothermometers: No definition has been provided for this term. Add a Definition Introduction Some experts have stated that the factor that changes the risk assessment of a geothermal prospect the fastest is obtaining attractive chemical confirmation (geothermometry, gas analyses) that a thermal resource exists

2

A BASIC program for calculating subsurface water temperatures using chemical geothermometers—implication to geothermal reservoir estimation  

Science Conference Proceedings (OSTI)

Keywords: BASIC, Na-K-Ca geothermometer, Na/K ratio, geothermometer, silica geothermometer, subsurface temperature

Ali El-Naqa; Nasser Abu Zeid

1993-11-01T23:59:59.000Z

3

Cation Geothermometers | Open Energy Information  

Open Energy Info (EERE)

Cation Geothermometers Cation Geothermometers Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Cation Geothermometers Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: Geochemical Data Analysis Parent Exploration Technique: Liquid Geothermometry Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Used to estimate reservoir temperatures. Dictionary.png Cation Geothermometers: No definition has been provided for this term. Add a Definition Introduction Some experts have stated that the factor that changes the risk assessment of a geothermal prospect the fastest is obtaining attractive chemical confirmation (geothermometry, gas analyses) that a thermal resource exists

4

Multicomponent Geothermometers | Open Energy Information  

Open Energy Info (EERE)

Multicomponent Geothermometers Multicomponent Geothermometers Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Multicomponent Geothermometers Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: Geochemical Data Analysis Parent Exploration Technique: Liquid Geothermometry Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Multicomponent Geothermometers: The multicomponent geothermometry method consists of using full chemical analyses of water samples to compute the saturation indices (log(Q/K)) of reservoir minerals over a range of temperatures. The saturation indices are graphed as a function of temperature, and the clustering of log(Q/K) curves

5

A CO2-Silica Geothermometer for Low Temperature Geothermal Resource Assessment, with Application to Resources in the Safford Basin, Arizona  

DOE Green Energy (OSTI)

Geothermics is the study of the earth's heat energy, it's affect on subsurface temperature distribution, it's physical and chemical sources, and it's role in dynamic geologic processes. The term, geothermometry, is applied to the determination of equilibrium temperatures of natural chemical systems, including rock, mineral, and liquid phases. An assemblage of minerals or a chemical system whose phase composition is a function of temperature and pressure can be used as a geothermometer. Thus a geothermometer is useful to determine the formation temperature of rock or the last equilibrium temperature of a flowing aqueous solution such as ground water and hydrothermal fluids.

Witcher, James C.; Stone, Claudia

1983-11-01T23:59:59.000Z

6

Definition: Multicomponent Geothermometers | Open Energy Information  

Open Energy Info (EERE)

Multicomponent Geothermometers Multicomponent Geothermometers Jump to: navigation, search Dictionary.png Multicomponent Geothermometers The multicomponent geothermometry method consists of using full chemical analyses of water samples to compute the saturation indices (log(Q/K)) of reservoir minerals over a range of temperatures. The saturation indices are graphed as a function of temperature, and the clustering of log(Q/K) curves near zero at any specific temperature (for a group of certain reservoir minerals) is used to infer the reservoir temperature.[1] References ↑ Berkeley Lab Earth Sciences Division Website: GeoT: A Computer Program for Multicomponent Geothermometry and Geochemical Speciation Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like. rieved from

7

CO/sub 2/-silica geothermometer for low temperature geothermal resource assessment, with application to resources in the Safford Basin, Arizona  

DOE Green Energy (OSTI)

This study investigates silica-water reactions in low-temperature geothermal water in areas near Safford, southeastern Arizona, and derives a pCO2 correction for conductive silica geothermometers. Use and limitations of the technique are also discussed. Data collection, interpretation approach, and basic geochemistry, as it applies to this study, are outlined. In addition, the geology, thermal regime, geohydrology, and gross geochemistry of the Safford area are reviewed. Finally, geothermal potential, as indicated by this study and previous studies is discussed.

Witcher, J.C.; Stone, C.

1983-11-01T23:59:59.000Z

8

Chemical Geothermometers And Mixing Models For Geothermal Systems | Open  

Open Energy Info (EERE)

Geothermometers And Mixing Models For Geothermal Systems Geothermometers And Mixing Models For Geothermal Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Chemical Geothermometers And Mixing Models For Geothermal Systems Details Activities (1) Areas (1) Regions (0) Abstract: Qualitative chemical geothermometers utilize anomalous concentrations of various "indicator" elements in groundwaters, streams, soils, and soil gases to outline favorable places to explore for geothermal energy. Some of the qualitative methods, such as the delineation of mercury and helium anomalies in soil gases, do not require the presence of hot springs or fumaroles. However, these techniques may also outline fossil thermal areas that are now cold. Quantitative chemical geothermometers and mixing models can provide information about present probable minimum

9

Application Of An Artificial Neural Network Model To A Na-K Geothermometer  

Open Energy Info (EERE)

Application Of An Artificial Neural Network Model To A Na-K Geothermometer Application Of An Artificial Neural Network Model To A Na-K Geothermometer Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Application Of An Artificial Neural Network Model To A Na-K Geothermometer Details Activities (3) Areas (2) Regions (0) Abstract: A new geothermometer model is proposed by applying data obtained from a known Na-K geothermometer to an artificial neural network. In this model, Na and K values were implemented as input signals and geothermometers as the output signal. Multi-layer perceptrons and back propagation were used as training algorithms for the artificial neural network. Reservoir temperatures of some geothermal fields in Turkey determined by this method are in accord with those determined from other methods.

10

New Improved Equations For Na-K, Na-Li And Sio2 Geothermometers...  

Open Energy Info (EERE)

Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Detection And Rejection Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: New...

11

A New Improved Na-K Geothermometer By Artificial Neural Networks | Open  

Open Energy Info (EERE)

Improved Na-K Geothermometer By Artificial Neural Networks Improved Na-K Geothermometer By Artificial Neural Networks Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A New Improved Na-K Geothermometer By Artificial Neural Networks Details Activities (0) Areas (0) Regions (0) Abstract: A new Na/K geothermometer equation has been developed. The temperature function is:Concentrations are in mg/kg. The new improved geothermometer equation was developed by artificial neural networks. The normalized mean square error (NMSE) used in the new improved Na/K equation for temperatures ranging from 94 to 345°C is 0.179, which is lower than the corresponding NMSE 0.226, 0.598, 0.656, 0.268, 0.328 and 0.225 for the equations of Arnorsson et al. (1983; Geochim. Cosmochim. Acta 47, 567-577), Truesdell (1975; Proc. 2nd UN Symposium), Tonani (1980; Proc. Adv. Eur.

12

Physicochemical basis of the Na-K-Ca geothermometer  

DOE Green Energy (OSTI)

Regular changes in solution composition were observed experimentally during granite reaction with dilute NaCl (+CaCl/sub 2/) solutions; these changes closely follow the empirical Na-K-Ca geothermometer relationship. Initial minerals forming the granite (quartz, plagioclase, K-feldspar, and biotite) were etched by the reactions. Alteration phases formed include calcium-zeolite at <300/sup 0/C, feldspar overgrowths at >300/sup 0/C, and minor amounts of clay and calcsilicate at all temperatures. Amphibole overgrowths were also found at 340/sup 0/C. Quartz is near saturation in all experiments, and preliminary calculations of aqueous species distributions and mineral affinities indicate that the solutions achieve super-saturation with feldspars as the temperature increase. A consistent variation attributable to pH differences was observed in the empirical geothermometer relationship for all experimental data. At 340/sup 0/C, the experimental solutions appear to have deviated slightly from the empirical Na-K-Ca relationship. Such deviations may also be found in natural systems that attain such temperatures.

Janecky, D.R.; Charles, R.W.; Bayhurst, G.K.; Benjamin, T.M.

1986-08-01T23:59:59.000Z

13

New Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier  

Open Energy Info (EERE)

Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Detection And Rejection Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: New Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Detection And Rejection Details Activities (1) Areas (1) Regions (0) Abstract: We present new improved equations for three still widely used Na/K, Na/Li and SiO2 geothermometers (obtained by statistical treatment of the data and application of outlier detection and rejection as well as theory of error propagation) and compare them with those by Fournier and others. New equations are also developed for estimating errors associated with the use of these new geothermometric equations and comparing them with the performance of the original equations. The errors in the use of the new

14

An Empirical Na-K-Ca Geothermometer For Natural Waters | Open Energy  

Open Energy Info (EERE)

Empirical Na-K-Ca Geothermometer For Natural Waters Empirical Na-K-Ca Geothermometer For Natural Waters Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Empirical Na-K-Ca Geothermometer For Natural Waters Details Activities (0) Areas (0) Regions (0) Abstract: An empirical method of estimating the last temperature of water-rock interaction has been devised. It is based upon molar Na, K and Ca concentrations in natural waters from temperature environments ranging from 4 to 340°C. The data for most geothermal waters cluster near a straight line when plotted as the function vs reciprocal of absolute temperature, where Β is either or depending upon whether the water equilibrated above or below 100°C. For most waters tested, the method gives better results than the methods suggested by other workers. The ratio

15

Improved silica geothermometer for low temperature geothermal resource assessment. Monthly progress report No. 2, February-March, 1983  

DOE Green Energy (OSTI)

Progress is reported on: literature search, collection of available lithologic and driller's logs, construction of geologic cross sections, and collection of water samples. (MHR)

Not Available

1983-03-01T23:59:59.000Z

16

Qrtzgeotherm: An ActiveX component for the quartz solubility geothermometer  

Science Conference Proceedings (OSTI)

An ActiveX component, QrtzGeotherm, to calculate temperature and vapor fraction in a geothermal reservoir using quartz solubility geothermometry was written in Visual Basic 6.0. Four quartz solubility equations along the liquid-vapor saturation curve: ... Keywords: ActiveX component, Computer program, QrtzGeotherm, QrtzGeothrm, Quartz geothermometry, Solubility equations, Visual Basic 6.0

Mahendra P. Verma

2008-12-01T23:59:59.000Z

17

Geochemical Techniques | Open Energy Information  

Open Energy Info (EERE)

Geochemical Techniques Geochemical Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Geochemical Techniques Details Activities (0) Areas (0) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: None Parent Exploration Technique: Exploration Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Geochemical Techniques: No definition has been provided for this term. Add a Definition Related Techniques Geochemical Techniques Geochemical Data Analysis Geothermometry Gas Geothermometry Isotope Geothermometry Liquid Geothermometry Cation Geothermometers Multicomponent Geothermometers Silica Geothermometers Thermal Ion Dispersion

18

Spreadsheets for Geothermal Water and Gas Geochemistry | Open...  

Open Energy Info (EERE)

and plots four common ternaries, three3 "YT" gas geothermometer grids and two gas ratio geothermometer grids, mainly derived from the work of Werner Giggenbach. Typical...

19

Geochemical studies at four northern Nevada hot spring areas. [Kyle Hot Springs, Leach Hot Springs, Buffalo Hot Springs, and Beowave Hot Springs  

DOE Green Energy (OSTI)

Water samples from both hot and cold sources in the hydrologic areas surrounding the hot springs were collected and analyzed. Analyses of major, trace, and radio-element abundances of the water samples and of associated rock samples are presented. From this study it is possible that trace- and major-element abundances and/or ratios may be discerned which are diagnostic as chemical geothermometers, complementing those of silica and alkali elements that are presently used. Brief discussions of mixing calculations, possible new chemical geothermometers, and interelement relationships are also included.

Wollenberg, H.; Bowman, H.; Asaro, F.

1977-08-01T23:59:59.000Z

20

Geothermometry At Long Valley Caldera Area (Sorey, Et Al., 1991) | Open  

Open Energy Info (EERE)

Long Valley Caldera Area (Sorey, Et Long Valley Caldera Area (Sorey, Et Al., 1991) Exploration Activity Details Location Long Valley Caldera Area Exploration Technique Geothermometry Activity Date Usefulness could be useful with more improvements DOE-funding Unknown Notes Silica-geothermometer temperature estimates for the Casa Diablo and RDO-8 well samples ( 196-202 degrees C) are lower than the corresponding cation-geothermometer temperature estimates, indicating loss of silica with declining reservoir temperature or dilution with low-silica waters. At shallow depths in the caldera References Michael L. Sorey, Gene A. Suemnicht, Neil C. Sturchio, Gregg A. Nordquist (1991) New Evidence On The Hydrothermal System In Long Valley Caldera, California, From Wells, Fluid Sampling, Electrical Geophysics, And

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Silica Sand  

NLE Websites -- All DOE Office Websites (Extended Search)

the molds and cores in foundries that make steel castings, and for casting gray iron, brass, aluminum and magnesium metals. Since silica sand has a very high melting point, it is...

22

Geothermometry At Desert Queen Area (Garchar & Arehart, 2008) | Open Energy  

Open Energy Info (EERE)

Queen Area (Garchar & Arehart, 2008) Queen Area (Garchar & Arehart, 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Desert Queen Area (Garchar & Arehart, 2008) Exploration Activity Details Location Desert Queen Area Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown Notes Temperatures of the reservoir at depth are estimated to be between 92-141 degrees C and were calculated using the δ18O(SO4-H2O) geothermometer. It is unclear whether these temperatures reflect waters from the outflow zone of the Desert Peak geothermal system, or waters from a different reservoir at Desert Queen. Quartz, chalcedony, amorphous silica, Na-K-Ca, and δ18O(SO4-H2O) geothermometer calculations were performed.

23

Geothermometry At Raft River Geothermal Area (1980) | Open Energy  

Open Energy Info (EERE)

Geothermometry At Raft River Geothermal Area (1980) Geothermometry At Raft River Geothermal Area (1980) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Geothermometry Activity Date 1980 Usefulness not indicated DOE-funding Unknown Notes Geothermometer temperatures of shallow samples suggest significant re-equilibration at temperatures below those found in the deep wells. Silica geothermometer temperatures of water samples from the deep wells are in reasonable agreement with measured temperatures, whereas Na-K-Ca temperatures are significantly higher than measured temperatures. The chemical characteristics of the water, as indicated by chloride concentration, are extremely variable in shallow and deep samples. Chloride concentrations of the deep samples range from 580 to 2200 mg/kg.

24

Geothermometry At Central Nevada Seismic Zone Region (Shevenell...  

Open Energy Info (EERE)

DOE-funding Unknown References Lisa Shevenell, Ted De Rocher (2005) Evaluation Of Chemical Geothermometers For Calculating Reservoir Temperatures At Nevada Geothermal Power...

25

Geothermometry At Walker-Lane Transitional Zone Region (Shevenell...  

Open Energy Info (EERE)

DOE-funding Unknown References Lisa Shevenell, Ted De Rocher (2005) Evaluation Of Chemical Geothermometers For Calculating Reservoir Temperatures At Nevada Geothermal Power...

26

Visibly photoluminescent silica aerogels  

NLE Websites -- All DOE Office Websites (Extended Search)

Visibly photoluminescent silica aerogels Title Visibly photoluminescent silica aerogels Publication Type Journal Article Year of Publication 1997 Authors Ayers, Michael R., and...

27

Silica Scaling Removal Process  

NLE Websites -- All DOE Office Websites (Extended Search)

Silica Scaling Removal Process Silica Scaling Removal Process Silica Scaling Removal Process Scientists at Los Alamos National Laboratory have developed a novel technology to remove both dissolved and colloidal silica using small gel particles. Available for thumbnail of Feynman Center (505) 665-9090 Email Silica Scaling Removal Process Applications: Cooling tower systems Water treatment systems Water evaporation systems Potential mining applications (produced water) Industry applications for which silica scaling must be prevented Benefits: Reduces scaling in cooling towers by up to 50% Increases the number of cycles of concentration substantially Reduces the amount of antiscaling chemical additives needed Decreases the amount of makeup water and subsequent discharged water (blowdown) Enables considerable cost savings derived from reductions in

28

Silica Scaling Removal Process  

NLE Websites -- All DOE Office Websites (Extended Search)

systems Water treatment systems Water evaporation systems Potential mining applications (produced water) Industry applications for which silica scaling must be prevented Benefits:...

29

Silica Scaling Removal Process  

NLE Websites -- All DOE Office Websites (Extended Search)

applications for which silica scaling must be prevented Benefits: Reduces scaling in cooling towers by up to 50% Increases the number of cycles of concentration substantially...

30

Hydrogen separation using silica membranes  

Science Conference Proceedings (OSTI)

Silica membranes were synthesized on tubular supports of alumina by dipping in silica colloidal solutions. The quality and the performance of the silica membranes were tested by experiments on single gas permeation and gas separation of mixed N2, ... Keywords: Knudsen diffusion, colloidal solution, gas permeation, hydrogen separation, silica membranes

Salvador Alfaroa; Miguel A. Valenzuelaa; Pedro Bosch

2008-11-01T23:59:59.000Z

31

Silica Embedded Metal Hydrides  

DOE Green Energy (OSTI)

A method to produce silica embedded metal hydride was developed. The product is a composite in which metal hydride particles are embedded in a matrix of silica. The silica matrix is highly porous. Hydrogen gas can easily reach the embedded metal hydride particles. The pores are small so that the metal hydride particles cannot leave the matrix. The porous matrix also protects the metal hydride particles from larger and reactive molecules such as oxygen, since the larger gas molecules cannot pass through the small pores easily. Tests show that granules of this composite can absorb hydrogen readily and withstand many cycles without making fines.

Heung, L.K. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wicks, G.G.

1998-08-01T23:59:59.000Z

32

Kinetics of silica polymerization  

DOE Green Energy (OSTI)

The polymerization of silicic acid in geothermal brine-like aqueous solutions to produce amorphous silica in colloidal form has been studied experimentally and theoretically. A large amount of high quality experimental data has been generated over the temperature rang 23 to 100{sup 0}C. Wide ranges of dissolved silica concentration, pH, and sodium chloride concentration were covered. The catalytic effects of fluoride and the reaction inhibiting effects of aluminum and boron were studied also. Two basic processes have been separately studied: the formation of new colloidal particles by the homogeneous nucleation process and the deposition of dissolved silica on pre-existing colloidal particles. A rigorous theory of the formation of colloidal particles of amorphous silica by homogeneous nucleation was developed. This theory employs the Lothe-Pound formalism, and is embodied in the computer code SILNUC which quantitatively models the homogeneous nucleation and growth of colloidal silica particles in more than enough detail for practical application. The theory and code were extensively used in planning the experimental work and analyzing the data produced. The code is now complete and running in its final form. It is capable of reproducing most of the experimental results to within experimental error. It is also capable of extrapolation to experimentally inaccessible conditions, i.e., high temperatures, rapidly varying temperature and pH, etc.

Weres, O.; Yee, A.; Tsao, L.

1980-05-01T23:59:59.000Z

33

Silica aerogel: synthesis and applications  

Science Conference Proceedings (OSTI)

Silica aerogels have drawn a lot of interest both in science and technology because of their low bulk density (up to 95% of their volume is air), hydrophobicity, low thermal conductivity, high surface area, and optical transparency. Aerogels are synthesized ...

Jyoti L. Gurav; In-Keun Jung; Hyung-Ho Park; Eul Son Kang; Digambar Y. Nadargi

2010-01-01T23:59:59.000Z

34

Sample Desorption/Ionization From Mesoporous Silica  

NLE Websites -- All DOE Office Websites (Extended Search)

Sample Desorption/Ionization From Mesoporous Silica Sample Desorption/Ionization From Mesoporous Silica Sample Desorption/Ionization From Mesoporous Silica Mesoporous silica is shown to be a sample holder for laser desorption/ionization of mass spectrometry. Available for thumbnail of Feynman Center (505) 665-9090 Email Sample Desorption/Ionization From Mesoporous Silica Mesoporous silica is shown to be a sample holder for laser desorption/ionization of mass spectrometry. Supported mesoporous silica was prepared by coating an ethanolic silicate solution having a removable surfactant onto a substrate to produce a self-assembled, ordered, nanocomposite silica thin film. The surfactant was chosen to provide a desired pore size between about 1 nanometer diameter and 50 nanometers diameter. Removal of the surfactant resulted in a mesoporous silica thin

35

Geothermometry At Upper Hot Creek Ranch Area (Benoit & Blackwell, 2006) |  

Open Energy Info (EERE)

Geothermometry At Upper Hot Creek Ranch Area (Benoit & Blackwell, 2006) Geothermometry At Upper Hot Creek Ranch Area (Benoit & Blackwell, 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Upper Hot Creek Ranch Area (Benoit & Blackwell, 2006) Exploration Activity Details Location Upper Hot Creek Ranch Area Exploration Technique Geothermometry Activity Date Usefulness useful DOE-funding Unknown Notes Ten water samples were collected for chemical analysis and interpretation. Analyses of three samples of the UHCR thermal give predicted subsurface temperatures ranging from 317 to 334 oF from the Na-K-Ca, silica (quartz), and Na-Li geothermometers. The fact that all three thermometers closely agree gives the predictions added credibility. References Dick Benoit, David Blackwell (2006) Exploration Of The Upper Hot

36

Removal of dissolved and colloidal silica  

DOE Patents (OSTI)

Small amorphous silica particles are used to provide a relatively large surface area upon which silica will preferentially adsorb, thereby preventing or substantially reducing scaling caused by deposition of silica on evaporative cooling tower components, especially heat exchange surfaces. The silica spheres are contacted by the cooling tower water in a sidestream reactor, then separated using gravity separation, microfiltration, vacuum filtration, or other suitable separation technology. Cooling tower modifications for implementing the invention process have been designed.

Midkiff, William S. (Ruidoso, NM)

2002-01-01T23:59:59.000Z

37

Stabilized fuel with silica support structure  

DOE Patents (OSTI)

This report describes a stabilized fuel which is supported by a silica support structure. The silica support structure provides a low density, high porosity vehicle for safely carrying hydrocarbon fuels. The silica support structure for hydrocarbon fuel does not produce toxic material residues on combustion which would pose environmentally sensitive disposal problems. The silica stabilized fuel composition is useful as a low temperature, continuous burning fire starter for wood or charcoal.

Poco, J.F.; Hrubesh, L.W.

1991-12-31T23:59:59.000Z

38

Elevated Silica Project at Palisades -- Final Report  

Science Conference Proceedings (OSTI)

Silica concentrations as high as 2-5 ppm in the primary water during startup at some pressurized water reactor (PWR) plants exceed the prevailing industry diagnostic limit of 1 ppm and raise concerns about the possible formation of tenacious silicate deposits on the fuel. To minimize the costs of removing excess silica at fuel outages, EPRI initiated an investigation on the effect of silica on fuel performance. This report documents the final stage of this research, a fuel surveillance project at Palisad...

2000-10-27T23:59:59.000Z

39

PWR RCS Elevated Silica - Fuel Surveillance  

Science Conference Proceedings (OSTI)

Many PWR plants have recently experienced silica concentration as high as 2-5 ppm in the primary water at startup. That level exceeds the prevailing industry diagnostic limit of 1 ppm for safeguarding fuel from potential deposition of tenacious silicates. The high silica experience is primarily limited to plants using silica-containing Boroflex storage racks, which tend to decay in the intense radiation environment in the storage pool. Some plants using recycled boric acid have also experienced high star...

1999-07-28T23:59:59.000Z

40

Cellular membrane trafficking of mesoporous silica nanoparticles  

Science Conference Proceedings (OSTI)

This dissertation mainly focuses on the investigation of the cellular membrane trafficking of mesoporous silica nanoparticles. We are interested in the study of endocytosis and exocytosis behaviors of mesoporous silica nanoparticles with desired surface functionality. The relationship between mesoporous silica nanoparticles and membrane trafficking of cells, either cancerous cells or normal cells was examined. Since mesoporous silica nanoparticles were applied in many drug delivery cases, the endocytotic efficiency of mesoporous silica nanoparticles needs to be investigated in more details in order to design the cellular drug delivery system in the controlled way. It is well known that cells can engulf some molecules outside of the cells through a receptor-ligand associated endocytosis. We are interested to determine if those biomolecules binding to cell surface receptors can be utilized on mesoporous silica nanoparticle materials to improve the uptake efficiency or govern the mechanism of endocytosis of mesoporous silica nanoparticles. Arginine-glycine-aspartate (RGD) is a small peptide recognized by cell integrin receptors and it was reported that avidin internalization was highly promoted by tumor lectin. Both RGD and avidin were linked to the surface of mesoporous silica nanoparticle materials to investigate the effect of receptor-associated biomolecule on cellular endocytosis efficiency. The effect of ligand types, ligand conformation and ligand density were discussed in Chapter 2 and 3. Furthermore, the exocytosis of mesoporous silica nanoparticles is very attractive for biological applications. The cellular protein sequestration study of mesoporous silica nanoparticles was examined for further information of the intracellular pathway of endocytosed mesoporous silica nanoparticle materials. The surface functionality of mesoporous silica nanoparticle materials demonstrated selectivity among the materials and cancer and normal cell lines. We aimed to determine the specific organelle that mesoporous silica nanoparticles could approach via the identification of harvested proteins from exocytosis process. Based on the study of endo- and exocytosis behavior of mesoporous silica nanoparticle materials, we can design smarter drug delivery vehicles for cancer therapy that can be effectively controlled. The destination, uptake efficiency and the cellular distribution of mesoporous silica nanoparticle materials can be programmable. As a result, release mechanism and release rate of drug delivery systems can be a well-controlled process. The deep investigation of an endo- and exocytosis study of mesoporous silica nanoparticle materials promotes the development of drug delivery applications.

Fang, I-Ju

2012-06-21T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Text of The Solubility of Silica in Calcium Ferrite Slags  

Science Conference Proceedings (OSTI)

To successfully use lime flux, the dissolution of silica in calcium-ferrite slags must ... samples were chemically analyzed by standard methods for calcium, silica, ...

42

Synthesis and properties of chitosan-silica hybrid aerogels  

NLE Websites -- All DOE Office Websites (Extended Search)

Synthesis and properties of chitosan-silica hybrid aerogels Title Synthesis and properties of chitosan-silica hybrid aerogels Publication Type Journal Article Year of Publication...

43

Synthesis and properties of Chitosan-silica hybrid aerogels  

E-Print Network (OSTI)

chitosan-silica composite aerogels can be easily synthesizedphysical properties of these aerogels. These materials may1. Top: Chitosan-silica aerogel (sample 4), Bottom: Same

Ayers, Michael R.; Hunt, Arlon J.

2001-01-01T23:59:59.000Z

44

Investigations of silica alcogel aging using coherent light  

NLE Websites -- All DOE Office Websites (Extended Search)

Investigations of silica alcogel aging using coherent light Title Investigations of silica alcogel aging using coherent light Publication Type Journal Article Year of Publication...

45

Pressure Drops Due to Silica Scaling  

DOE Green Energy (OSTI)

Experience with reinjection returns in many geothermal fields has prompted a move towards injecting waste fluids at some distance from the production field. This means that often, reinjection pipelines cover very long distances. If the waste water in the pipelines is supersaturated with respect to amorphous silica, then the deposition of silica in these pipelines is almost certain. Although the deposit may be of negligible thickness, the inner surface characteristics of the pipe will be different to those of clean mild steel. During a silica scaling experiment. geothermal brine was passed through a series of pipes of different sizes and over a period of three weeks, silica scale formed on the inner surface. The pressure drop along a distance of approximately 5m was measured by a water manometer in all test pipe sections. Significant pressure drop was observed during this time and can be correlated with the increase in the friction factor of the pipe walls due to silica scaling.

Brown, K.L.; Freeston, D.H.; Dimas, Z.O.; Slatter, A.

1995-01-01T23:59:59.000Z

46

LIGHT SCATTERING STUDIES OF SILICA AEROGELS  

E-Print Network (OSTI)

S.S. , "Coherent Expanded Aerogels," J. of Phys. Chern.Production of Silica Aerogel," Physica Scripta 23, Nicolaon,S.J. , "Preparation des aerogels de silice a partir

Hunt, A.J.

2010-01-01T23:59:59.000Z

47

Silica-coated liposomes for insulin delivery  

Science Conference Proceedings (OSTI)

Liposomes coated with silica were explored as protein delivery vehicles for their enhanced stability and improved encapsulation efficiency. Insulin was encapsulated within the fluidic phosphatidylcholine lipid vesicles by thin film hydration at pH 2.5, ...

Neelam Dwivedi; M. A. Arunagirinathan; Somesh Sharma; Jayesh Bellare

2010-01-01T23:59:59.000Z

48

Chemistry of silica in Cerro Prieto brines  

DOE Green Energy (OSTI)

The precipitation of amorphous silica from synthetic geothermal brines which resemble the flashed brine at Cerro Prieto has been studied. It was found that part of the dissolved silica quickly polymerizes to form suspended colloidal silica. The colloidal silica flocculates and settles slowly at unmodified brine pH values near 7.35. Raising the pH of the brine to about 7.8 by adding base and stirring for a few minutes causes rapid and complete flocculation and settling. These results have been confirmed in the field using actual Cerro Prieto brine. Both in the laboratory and in the field quaternary amines were found to be effective with some brine compositions but not with others. Polyacrylamides do not work at all. These results suggest the following simple preinjection brine treatment process: age the brine for 10 to 20 minutes in a covered holding tank, add 20 to 30 ppM lime (CaO), stir for 5 minutes, and separate the flocculated silica from the brine using a conventional clarifier. The brine coming out of such a process will be almost completely free of suspended solids. The pilot plant tests needed to reduce this conceptual process to practice are discussed. The rate of deposition of silica scale from synthetic brines was separately studied. It was found that a modest decrease in pH could significantly reduce the scaling rate at a reasonable cost. The equilibrium chemistry of Cerro Prieto brine was studied theoretically. These calculations indicate that increasing the brine pH to remove silica might cause some precipitation of carbonate minerals, but also that this problem could easily be eliminated at a reasonable cost if it did arise.

Weres, O.; Tsao, L.; Iglesias, E.

1980-04-01T23:59:59.000Z

49

Chemistry of Silica in Cerro Prieto Brines  

DOE Green Energy (OSTI)

The precipitation of amorphous silica from synthetic geothermal, brines which resemble the flashed brine at Cerro Prieto has been studied. It was found that part of the dissolved silica quickly polymerizes to form suspended colloidal silica. The colloidal silica flocculates and settles slowly at unmodified brine pH values near 7.35. Raising the pH of the brine to about 7.8 by adding base and stirring for a few minutes causes rapid and complete flocculation and settling. these results have been confirmed in the field using actual Cerro Prieto brine. Both in the laboratory and in the field quaternary amines were found to be effective with some brine compositions but not with others. Polyacrylamides do not work at all. These results suggest the following simple preinjection brine treatment process: age the brine for 10-20 minutes in a covered holding tank, add 20-30 ppm lime (CaO), stir for 5 minutes, and separate the flocculated silica from the brine using a conventional clarifier. The brine coming out of such a process will be almost completely free of suspended solids. The pilot plant tests needed to reduce this conceptual process to practice are discussed. The rate of deposition of silica scale from synthetic brines was separately studied. It was found that a modest decrease in pH could significantly reduce the scaling rate at a reasonable cost. The equilibrium chemistry of Cerro Prieto brine was studied theoretically. These calculations indicate that increasing the brine pH to remove silica might cause some precipitation of carbonate minerals, but also that this problem could easily be eliminated at a reasonable cost if it did arise.

Weres, Oleh; Iglesias, Eduardo; Tsao, Leon

1980-04-01T23:59:59.000Z

50

High resolution patterning of silica aerogels  

SciTech Connect

Three-dimensional metallic structures are fabricated with high spatial resolution in silica aerogels. In our method, silica hydrogels are prepared with a standard base-catalyzed route, and exchanged with an aqueous solution typically containing Ag{sup +} ions (1 M) and 2-propanol (0.2 M). The metal ions are reduced photolytically with a table-top ultraviolet lamp, or radiolytically, with a focused X-ray beam. We fabricated dots and lines as small as 30 x 70 {micro}m, protruding for several mm into the bulk of the materials. The hydrogels are eventually supercritically dried to yield aerogels, without any measurable change in the shape and spatial resolution of the lithographed structures. Transmission electron microscopy shows that illuminated regions are composed by Ag clusters with a size of several {micro}m, separated by thin layers of silica.

Bertino, M.F.; Hund, J.F.; Sosa, J.; Zhang, G.; Sotiriou-Leventis, C.; Leventis, N.; Tokuhiro, A.T.; Terry, J. (UMR-MUST); (IIT)

2008-10-30T23:59:59.000Z

51

Measurement of muonium emission from silica aerogel  

E-Print Network (OSTI)

Emission of muonium ($\\mu^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics of muonium emission were established from silica aerogel samples with densities in the range from 29 mg cm$^{-3}$ to 178 mg cm$^{-3}$. Spectra of muonium decay times correlated with distances from the aerogel surfaces, which are sensitive to the speed distributions, follow general features expected from a diffusion process, while small deviations from a simple room-temperature thermal diffusion model are identified. The parameters of the diffusion process are deduced from the observed yields.

Bakule, P; Contreras, D; Esashi, M; Fujiwara, Y; Fukao, Y; Hirota, S; Iinuma, H; Ishida, K; Iwasaki, M; Kakurai, T; Kanda, S; Kawai, H; Kawamura, N; Marshall, G M; Masuda, H; Matsuda, Y; Mibe, T; Miyake, Y; Okada, S; Olchanski, K; Olin, A; Onishi, H; Saito, N; Shimomura, K; Strasser, P; Tabata, M; Tomono, D; Ueno, K; Yokoyama, K; Yoshida, S

2013-01-01T23:59:59.000Z

52

Measurement of muonium emission from silica aerogel  

E-Print Network (OSTI)

Emission of muonium ($\\mu^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics of muonium emission were established from silica aerogel samples with densities in the range from 29 mg cm$^{-3}$ to 178 mg cm$^{-3}$. Spectra of muonium decay times correlated with distances from the aerogel surfaces, which are sensitive to the speed distributions, follow general features expected from a diffusion process, while small deviations from a simple room-temperature thermal diffusion model are identified. The parameters of the diffusion process are deduced from the observed yields.

P. Bakule; G. A. Beer; D. Contreras; M. Esashi; Y. Fujiwara; Y. Fukao; S. Hirota; H. Iinuma; K. Ishida; M. Iwasaki; T. Kakurai; S. Kanda; H. Kawai; N. Kawamura; G. M. Marshall; H. Masuda; Y. Matsuda; T. Mibe; Y. Miyake; S. Okada; K. Olchanski; A. Olin; H. Onishi; N. Saito; K. Shimomura; P. Strasser; M. Tabata; D. Tomono; K. Ueno; K. Yokoyama; S. Yoshida

2013-06-17T23:59:59.000Z

53

Safety Bulletin 2007-08 Silica Dust Exposure  

NLE Websites -- All DOE Office Websites (Extended Search)

minerals. Potential work exposure to airborne crystalline silica includes abrasive blasting, sandblasting, rock cutting, chipping, drilling, grinding, jack hammering, concrete...

54

A threshold Cherenkov detector for K separation using silica aerogel  

E-Print Network (OSTI)

A threshold Cherenkov detector for Kþ =pþ separation using silica aerogel R. Siudak a,b , A August 2008 Keywords: Threshold Cherenkov detector Silica aerogel Reaction pp ! Kþ ðLp� Kþ =pþ separation in the focal plane of a magnetic spectrograph. Silica aerogel with refractive index of n ¼ 1:05 is applied

Magiera, Andrzej

55

Characterization of vanadium/silica and copper/silica aerogel catalysts  

DOE Green Energy (OSTI)

Vanadium/silica and copper/silica aerogels have been prepared using the sol-gel method followed by CO{sub 2} exchange and supercritical extraction. Structural properties of samples supercritically dried, oxidized and used in reactions studies conducted with a feed representing the average composition of automobile exhaust from a lean burn engine were investigated using laser Raman spectroscopy and temperature-programmed reduction. No evidence of crystalline V{sub 2}O{sub 5} was found for the vanadium/silica aerogel, freshly extracted, oxidized or following exposure to reaction conditions using these techniques. However, results obtained for the copper/silica sample indicate that changes in the structure of the copper species had occurred as the sample was oxidized and exposed to reaction conditions.

Owens, L.; Tillotson, T.M.; Hair, L.M. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Dept.

1995-09-01T23:59:59.000Z

56

Molecular sieving silica membrane fabrication process  

DOE Patents (OSTI)

A process is described for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film. 11 figs.

Raman, N.K.; Brinker, C.J.

1999-08-10T23:59:59.000Z

57

Moisture transport in silica gel particle beds  

DOE Green Energy (OSTI)

A theoretical and experimental study of the performance of silica gel packed particle beds is described. A bench-scale test rig was used to obtain data for parameter values pertinent to solar air-conditioning applications. Both adsorption and desorption experiments were performed for Regular Density (RD) silica gel for a wide range of particle size. Adsorption data were also obtained for Intermediate Density (ID) gel. A model of heat and mass transfer in the bed was developed with special attention paid to the modeling of solid side resistance. For this latter purpose an extensive review of the available literature on moisture adsorption and moisture transport in silica gel was made. Both Knudsen and surface diffusion are found to be important mechanisms of moisture transport in Intermediate Density gels while surface diffusion is dominant in Regular Density gels. A general equation for moisture transport in a spherical silica gel particle was developed and was incorporated into the model equations governing heat and mass transfer between the gel particles and air flowing through a packed particle bed. A computer code DESICCANT was written to solve the coupled set of partial differential equations using a finite difference numerical method. The agreement between theory and experiment for adsorption on RD gel is satisfactory, and is somewhat better for the outlet water vapor concentration than for the outlet air temperature. The agreement for desorption from RD gel and adsorption to ID gel is satisfactory, but not as good as for adsorption on RD gel.

Pesaran, A.A.

1983-02-01T23:59:59.000Z

58

Significant Silica Solubility in Geothermal Steam  

DOE Green Energy (OSTI)

Although it is widely believed that silica solubility in low pressure (5 to 10 bar) geothermal steam is negligible, when one takes into account steam flows exceeding 10 million tonnes a year--at Wairakei, for instance--it is found that the amount transmitted in the vapor has the potential to give significant deposits on turbine nozzles and blades. A 150 MWe power station, when based on flows from a hot water reservoir at (a) 250 C or (b) 315 C, and with separator pressures of 6 bar, is found to carry about 100 and 200 kg/year respectively in the steam phase. In the case of a similar sized station exploiting a dry steam reservoir such as The Geysers, equivalent silica flows are obtained, dissolved in steam and carried as dust--the latter as solid particles precipitating from the vapor en route from source to turbine, and not preexisting in the formations as is commonly considered. Choking or coating of subterranean rock near such dry steam wells due to exsolving silica, may be the principal cause of declining steam discharge under production. Silica from completely dry or superheated steam can also seal the cap and sides of steam reservoirs when expanding below the criticus temperature (236 C) in a way previously thought possible only by hot water or wet steam.

James, Russell

1986-01-21T23:59:59.000Z

59

Molecular sieving silica membrane fabrication process  

DOE Patents (OSTI)

A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

Raman, Narayan K. (400 Maple St. SE., Apartment 112, Albuquerque, NM 87106); Brinker, Charles Jeffrey (14 Eagle Nest Dr., NE., Albuquerque, NM 87122)

1998-01-01T23:59:59.000Z

60

Molecular sieving silica membrane fabrication process  

DOE Patents (OSTI)

A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

Raman, Narayan K. (Monroeville, PA); Brinker, Charles Jeffrey (Albuquerque, NM)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Conversion of geothermal waste to commercial products including silica  

DOE Patents (OSTI)

A process for the treatment of geothermal residue includes contacting the pigmented amorphous silica-containing component with a depigmenting reagent one or more times to depigment the silica and produce a mixture containing depigmented amorphous silica and depigmenting reagent containing pigment material; separating the depigmented amorphous silica and from the depigmenting reagent to yield depigmented amorphous silica. Before or after the depigmenting contacting, the geothermal residue or depigmented silica can be treated with a metal solubilizing agent to produce another mixture containing pigmented or unpigmented amorphous silica-containing component and a solubilized metal-containing component; separating these components from each other to produce an amorphous silica product substantially devoid of metals and at least partially devoid of pigment. The amorphous silica product can be neutralized and thereafter dried at a temperature from about 25.degree. C. to 300.degree. C. The morphology of the silica product can be varied through the process conditions including sequence contacting steps, pH of depigmenting reagent, neutralization and drying conditions to tailor the amorphous silica for commercial use in products including filler for paint, paper, rubber and polymers, and chromatographic material.

Premuzic, Eugene T. (East Moriches, NY); Lin, Mow S. (Rocky Point, NY)

2003-01-01T23:59:59.000Z

62

Carbon nanomaterials in silica aerogel matrices  

SciTech Connect

Silica aerogels are ultra low-density, high surface area materials that are extremely good thermal insulators and have numerous technical applications. However, their mechanical properties are not ideal, as they are brittle and prone to shattering. Conversely, single-walled carbon nanotubes (SWCNTs) and graphene-based materials, such as graphene oxide, have extremely high tensile strength and possess novel electronic properties. By introducing SWCNTs or graphene-based materials into aerogel matrices, it is possible to produce composites with the desirable properties of both constituents. We have successfully dispersed SWCNTs and graphene-based materials into silica gels. Subsequent supercritical drying results in monolithic low-density composites having improved mechanical properties. These nanocomposite aerogels have great potential for use in a wide range of applications.

Hamilton, Christopher E [Los Alamos National Laboratory; Chavez, Manuel E [Los Alamos National Laboratory; Duque, Juan G [Los Alamos National Laboratory; Gupta, Gautam [Los Alamos National Laboratory; Doorn, Stephen K [Los Alamos National Laboratory; Dattelbaum, Andrew M [Los Alamos National Laboratory; Obrey, Kimberly A D [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

63

(129)Xe NMR of Mesoporous Silicas  

DOE Green Energy (OSTI)

The porosities of three mesoporous silica materials were characterized with {sup 129}Xe NMR spectroscopy. The materials were synthesized by a sol-gel process with r = 0, 25, and 70% methanol by weight in an aqueous cetyltrimethylammonium bromide solution. Temperature dependent chemical shifts and spin lattice relaxation times reveal that xenon does not penetrate the pores of the largely disordered (r= 70%) silica. For both r = 0 and 25%, temperature dependent resonances corresponding to physisorbed xenon were observed. An additional resonance for the r = 25% sample was attributed to xenon between the disordered cylindrical pores. 2D NMR exchange experiments corroborate the spin lattice relaxation data which show that xenon is in rapid exchange between the adsorbed and the gas phase.

Anderson, M.T.; Asink, R.A.; Kneller, J.M.; Pietrass, T.

1999-04-23T23:59:59.000Z

64

Interaction of silica nano-particles with a flat silica surface through neutron reflectometry  

SciTech Connect

Neutron reflectometry (NR) was employed to study the interaction of nanosized silica particles with a flat silica surface in aqueous solutions. Unlike other experimental tools that are used to study surface interactions, NR can provide information on the particle density profile in the solution near the interface. Two types of silica particles (25 and 100 nm) were suspended in aqueous solutions of varying ionic strength. Theoretical calculations of the surface interaction potential between a particle and a flat silica surface using the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory were compared to the experimental data. The theory predicts that the potential energy is highly dependent on the ionic strength. In high ionic strength solutions, NR reveals a high concentration of particles near the flat silica surface. Under the same conditions, theoretical calculations show an attractive force between a particle and a flat surface. For low ionic strength solutions, the particle concentration near the surface obtained from NR is the same as the bulk concentration, while depletion of particles near the surface is expected because of the repulsion predicted by the DLVO theory.

Chung, Eunhyea [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Halbert, Candice E [ORNL; Ankner, John Francis [ORNL; Wang, Wei [ORNL; Tsouris, Costas [ORNL

2012-01-01T23:59:59.000Z

65

Recent progress in silica aerogel Cherenkov radiator  

E-Print Network (OSTI)

In this paper, we present recent progress in the development of hydrophobic silica aerogel as a Cherenkov radiator. In addition to the conventional method, the recently developed pin-drying method for producing high-refractive-index aerogels with high transparency was studied in detail. Optical qualities and large tile handling for crack-free aerogels were investigated. Sufficient photons were detected from high-performance aerogels in a beam test.

Tabata, Makoto; Kawai, Hideyuki; Kubo, Masato; Sato, Takeshi

2012-01-01T23:59:59.000Z

66

Thermal Conductivity of Cubic and Hexagonal Mesoporous Silica Thin Films  

E-Print Network (OSTI)

K.L. Fang, “Anisotropic thermal conductivity of nanoporousmesoporous silica as a thermal isolation layer”, Ceramicsand V. Wittwer, “Some thermal and optical properties of a

Coquil, Thomas; Richman, Eric K.; Hutchinson, Neal J.; Tolbert, S H; Pilon, Laurent

2009-01-01T23:59:59.000Z

67

Dynamic performance characterization of bound, porous silica gel desiccant  

DOE Green Energy (OSTI)

Drying of air with silica gel is a well established procedure. However, for the specific use of silica gel in a novel desiccant air conditioning system, which continually cools the silica gel and utilizes solar energy for silica gel regeneration, conventional packed bed devices are not suitable. For this system to operate effectively the silica gel must not rise in its temperature or its capacity will be greatly diminished. Dynamic dehumidificatuion performance was investigted for a silica gel desiccant fabricated in bound, porous paper-like sheets. Sheets of various thickness (0.7 to 3 mm) were fabricated and tested under several dynamic flow conditions in a flat rectangular channel apparatus. During each experiment conditions of inlet moisture, air flowrate, and sheet temperature were maintained constant. Comparisons were also made with conventional silica gel pellets and with other forms of bound silica gel. The sheets show superior utilization of silica gel in short times (30 minutes or less). Tests were also made to examine the sheet structure in order to explore the effect of temperature on the porous structure, and to obtain pore size distributions.

Onischak, M.; Gidaspow, D.; Perkari, S.; Sasaki, T.

1979-10-01T23:59:59.000Z

68

Mesoporous Silica-Supported Rhodium Nanocatalysts for Selective...  

NLE Websites -- All DOE Office Websites (Extended Search)

Mesoporous Silica-Supported Rhodium Nanocatalysts for Selective Production of Ethanol From Syngas and Conversion of Ethanol to Hydrogen Description Coal will likely play a major...

69

Heat Transfer through Materials: Application to Silica Aerogels...  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Transfer through Materials: Application to Silica Aerogels and Building Envelopes Speaker(s): Brangre Lartigue Date: December 19, 2005 - 12:00pm Location: Bldg. 90 After...

70

Feasibility of using silica aerogel as insulation for buildings.  

E-Print Network (OSTI)

?? For recent years, silica aerogel has attracted great attention and been extensively used in different technical fields owning to its remarkable properties in optics,… (more)

Huang, Lang

2012-01-01T23:59:59.000Z

71

Dual-Layer Asymmetric Microporous Silica Membranes  

DOE Green Energy (OSTI)

We report a novel sol-gel dip-coating process to form dual-layer microporous silica membranes with improved membrane performance and reproducibility. First, we deposit a surfactant-templated silica (STS) intermediate layer on top of a commercial {gamma}-alumina support both to improve its ''surface finish'' and to prevent a subsequently deposited microporous overlayer from penetrating into the support. Second, membranes are processed under clean room conditions to avoid dust contamination and, third, membranes are vacuum-calcined to promote further pore shrinkage and impart surface hydrophobicity. The resulting asymmetric membrane exhibits a gradual change in pore diameter from 50{angstrom} ({gamma}-alumina support layer) to 10-12{angstrom} (STS intermediate layer), and then to 3-4{angstrom} (30nm thick, ultramicroporous silica top-layer). Compared to a single-layer process using only the microporous overlayer, the dual-layer process improves both flux and selectivity. For the industrially important problem of natural gas purification, the combined CO{sub 2} flux [(3{approx} 0.5) x 10{sup {minus}4} cm{sup 3}(STP)/(s{center_dot}cm{sup 2}{center_dot}cm-Hg)] and CO{sub 2}/CH{sub 4} separation factors [200{approx}600] are superior to all previously reported values for separation of a 50/50 (v/v) CO{sub 2}/CH{sub 4} gas mixture. In addition, the membrane selectively separated hydrogen from a simulated reformate from partial oxidation of methanol as evidenced by a high concentration of hydrogen recovery.

TSAI,CHUNG-YI; TAM,SIU-YUE; LU,YUNFENG; BRINKER,C. JEFFREY

1999-11-19T23:59:59.000Z

72

Hydrophobic silica aerogel production at KEK  

E-Print Network (OSTI)

We present herein a characterization of a standard method used at the High Energy Accelerator Research Organization (KEK) to produce hydrophobic silica aerogels and expand this method to obtain a wide range of refractive index (n = 1.006-1.14). We describe in detail the entire production process and explain the methods used to measure the characteristic parameters of aerogels, namely the refractive index, transmittance, and density. We use a small-angle X-ray scattering (SAXS) technique to relate the transparency to the fine structure of aerogels.

Tabata, Makoto; Kawai, Hideyuki; Sumiyoshi, Takayuki; Yokogawa, Hiroshi

2011-01-01T23:59:59.000Z

73

Hydrophobic silica aerogel production at KEK  

E-Print Network (OSTI)

We present herein a characterization of a standard method used at the High Energy Accelerator Research Organization (KEK) to produce hydrophobic silica aerogels and expand this method to obtain a wide range of refractive index (n = 1.006-1.14). We describe in detail the entire production process and explain the methods used to measure the characteristic parameters of aerogels, namely the refractive index, transmittance, and density. We use a small-angle X-ray scattering (SAXS) technique to relate the transparency to the fine structure of aerogels.

Makoto Tabata; Ichiro Adachi; Hideyuki Kawai; Takayuki Sumiyoshi; Hiroshi Yokogawa

2011-12-14T23:59:59.000Z

74

Silica scaling in simulated geothermal brines  

DOE Green Energy (OSTI)

A 6.3 1/sec (100 GPM) titanium corrosion test loop was modified to provide a dynamic facility for studying the formation of silica deposits, their properties and fates, as a function of brine composition, temperature, and flow conditions. Scale formation was studied in a segmented heat exchanger operating under realistic conditions; the segmented design permitted examination of scale formations in five temperature regimes. The program was terminated after minimal exploratory operation because of reduced sponsor perceptions of the need for concern with scaling problems. The runs which were completed dealt cursorily with brine concentration and pH effects. Results are presented.

Bohlmann, E.G.; Shor, A.J.; Berlinski, P.; Mesmer, R.E.

1981-04-01T23:59:59.000Z

75

Fibrous composites comprising carbon nanotubes and silica  

DOE Patents (OSTI)

Fibrous composite comprising a plurality of carbon nanotubes; and a silica-containing moiety having one of the structures: (SiO).sub.3Si--(CH.sub.2).sub.n--NR.sub.1R.sub.2) or (SiO).sub.3Si--(CH.sub.2).sub.n--NCO; where n is from 1 to 6, and R.sub.1 and R.sub.2 are each independently H, CH.sub.3, or C.sub.2H.sub.5.

Peng, Huisheng (Shanghai, CN); Zhu, Yuntian Theodore (Cary, NC); Peterson, Dean E. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)

2011-10-11T23:59:59.000Z

76

Silica-Coated Titania and Zirconia Colloids for Subsurface Transport  

E-Print Network (OSTI)

, Environmental Engineering Program, Yale University, New Haven, Connecticut 06520-8286, and Department of Civil transport experiments. Electrophoretic mobility measurements showed that coating with silica imparted electrophoretic mobility and size (by dynamic light scattering) over a 90-day period showed that the silica

Elimelech, Menachem

77

Functionalization of silica nanoparticles for polypropylene nanocomposite applications  

Science Conference Proceedings (OSTI)

Synthetic silica nanospheres of 20 and 100nm diameter were produced via the sol-gel method to be used as filler in polypropylene (PP) composites. Modification of the silica surface was further performed by reaction with organic chlorosilanes in order ...

Diego Bracho, Vivianne N. Dougnac, Humberto Palza, Raúl Quijada

2012-01-01T23:59:59.000Z

78

Community Geothermal Technology Program: Silica bronze project. Final report  

DOE Green Energy (OSTI)

Objective was to incorporate waste silica from the HGP-A geothermal well in Pohoiki with other refractory materials for investment casting of bronze sculpture. The best composition for casting is about 50% silica, 25% red cinders, and 25% brick dust; remaining ingredient is a binder, such as plaster and water.

Bianchini, H.

1989-10-01T23:59:59.000Z

79

Simulations Reveal That Earth's Silica Is Predominantly Superficial - NERSC  

NLE Websites -- All DOE Office Websites (Extended Search)

Reveal Reveal Earth's Silica Is Predominantly Superficial Simulations Reveal Earth's Silica Is Predominantly Superficial May 24, 2010 Silica is one of the most common minerals on Earth. Not only does it make up two-thirds of our planet's crust, it is also used to create a variety of materials from glass to ceramics, computer chips and fiber optic cables. Yet new quantum mechanics results generated by a team of physicists from Ohio State University (OSU) show that this mineral only populates our planet superficially-in other words, silica is relatively uncommon deep within the Earth. Cross-section of the Earth Using several of the largest supercomputers in the nation, including the National Energy Research Scientific Computing Center's (NERSC) Cray XT4 "Franklin" system, the team simulated the behavior of silica in

80

Exploration of the Upper Hot Creek Ranch Geothermal Resource, Nye County, Nevada  

DOE Green Energy (OSTI)

The Upper Hot Creek Ranch (UHCR) geothermal system had seen no significant exploration activity prior to initiation of this GRED III project. Geochemical geothermometers calculated from previously available but questionable quality analyses of the UHCR hot spring waters indicated possible subsurface temperatures of +320 oF. A complex Quaternary and Holocene faulting pattern associated with a six mile step over of the Hot Creek Range near the UHCR also indicated that this area was worthy of some exploration activity. Permitting activities began in Dec. 2004 for the temperature-gradient holes but took much longer than expected with all drilling permits finally being received in early August 2005. The drilling and geochemical sampling occurred in August 2005. Ten temperature gradient holes up to 500’ deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five. Four of the five holes drilled to depths of 300 to 400’ encountered temperatures close to the expected regional thermal background conditions. These four holes failed to find any evidence of a large thermal anomaly surrounding the UHCR hot springs. The fifth hole, located within a narrow part of Hot Creek Canyon, encountered a maximum temperature of 81 oF at a depth of 105’ but had cooler temperatures at greater depth. Temperature data from this hole can not be extrapolated to greater depths. Any thermal anomaly associated with the UHCR geothermal system is apparently confined to the immediate vicinity of Hot Creek Canyon where challenges such as topography, a wilderness study area, and wetlands issues will make further exploration time consuming and costly. Ten water samples were collected for chemical analysis and interpretation. Analyses of three samples of the UHCR thermal give predicted subsurface temperatures ranging from 317 to 334 oF from the Na-K-Ca, silica (quartz), and Na-Li geothermometers. The fact that all three thermometers closely agree gives the predictions added credibility. Unfortunately, the final result of this exploration is that a moderate temperature geothermal resource has been clearly identified but it appears to be restricted to a relatively small area that would be difficult to develop.

Dick Benoit; David Blackwell

2005-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Exploration of the Upper Hot Creek Ranch Geothermal Resource, Nye County, Nevada  

DOE Green Energy (OSTI)

The Upper Hot Creek Ranch (UHCR) geothermal system had seen no significant exploration activity prior to initiation of this GRED III project. Geochemical geothermometers calculated from previously available but questionable quality analyses of the UHCR hot spring waters indicated possible subsurface temperatures of +320 oF. A complex Quaternary and Holocene faulting pattern associated with a six mile step over of the Hot Creek Range near the UHCR also indicated that this area was worthy of some exploration activity. Permitting activities began in Dec. 2004 for the temperature-gradient holes but took much longer than expected with all drilling permits finally being received in early August 2005. The drilling and geochemical sampling occurred in August 2005. Ten temperature gradient holes up to 500’ deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five. Four of the five holes drilled to depths of 300 to 400’ encountered temperatures close to the expected regional thermal background conditions. These four holes failed to find any evidence of a large thermal anomaly surrounding the UHCR hot springs. The fifth hole, located within a narrow part of Hot Creek Canyon, encountered a maximum temperature of 81 oF at a depth of 105’ but had cooler temperatures at greater depth. Temperature data from this hole can not be extrapolated to greater depths. Any thermal anomaly associated with the UHCR geothermal system is apparently confined to the immediate vicinity of Hot Creek Canyon where challenges such as topography, a wilderness study area, and wetlands issues will make further exploration time consuming and costly. Ten water samples were collected for chemical analysis and interpretation. Analyses of three samples of the UHCR thermal give predicted subsurface temperatures ranging from 317 to 334 oF from the Na-K-Ca, silica (quartz), and Na-Li geothermometers. The fact that all three thermometers closely agree gives the predictions added credibility. Unfortunately, the final result of this exploration is that a moderate temperature geothermal resource has been clearly identified but it appears to be restricted to a relatively small area that would be difficult to develop.

Dick Benoit; David Blackwell

2006-01-01T23:59:59.000Z

82

Laser Damage Precursors in Fused Silica  

Science Conference Proceedings (OSTI)

There is a longstanding, and largely unexplained, correlation between the laser damage susceptibility of optical components and both the surface quality of the optics, and the presence of near surface fractures in an optic. In the present work, a combination of acid leaching, acid etching, and confocal time resolved photoluminescence (CTP) microscopy has been used to study laser damage initiation at indentation sites. The combination of localized polishing and variations in indentation loads allows one to isolate and characterize the laser damage susceptibility of densified, plastically flowed and fractured fused silica. The present results suggest that: (1) laser damage initiation and growth are strongly correlated with fracture surfaces, while densified and plastically flowed material is relatively benign, and (2) fracture events result in the formation of an electronically defective rich surface layer which promotes energy transfer from the optical beam to the glass matrix.

Miller, P; Suratwala, T; Bude, J; Laurence, T A; Shen, N; Steele, W A; Feit, M; Menapace, J; Wong, L

2009-11-11T23:59:59.000Z

83

Water dynamics in controlled pore silica glasses  

DOE Green Energy (OSTI)

Water in porous silica glass is a suitable system for investigating the effect of confinement on translational diffusion. These systems are important because of their relevance in catalytic and separation processes. Two factors are to be considered in the case of confined water: (1) the effects of hydrophilic and hydrophobic surfaces on interfacial water and (2) how the dynamics of the hydrogen bond network changes due to the volume of confinement. Here quasi-elastic neutron scattering experiments at room temperature on water filled controlled pore glasses with radius of 15, 24 and 32 {angstrom}, are presented and analyzed using the random-jump diffusion model. Both the average residence time and the mean jump distance increase with decreasing pore radius.

Bordallo, H. N.; Herwig, K. W.; Dozier, W. D.; Drake, F.

1999-12-09T23:59:59.000Z

84

Ambient-pressure silica aerogel films  

SciTech Connect

Very highly porous (aerogel) silica films with refractive index in the range 1.006--1.05 (equivalent porosity 98.5--88%) were prepared by an ambient-pressure process. It was shown earlier using in situ ellipsometric imaging that the high porosity of these films was mainly attributable to the dilation or `springback` of the film during the final stage of drying. This finding was irrefutably reconfirmed by visually observing a `springback` of >500% using environmental scanning electron microscopy (ESEM). Ellipsometry and ESEM also established the near cent per cent reversibility of aerogel film deformation during solvent intake and drying. Film thickness profile measurements (near the drying line) for the aerogel, xerogel and pure solvent cases are presented from imaging ellipsometry. The thickness of these films (crack-free) were controlled in the range 0.1-3.5 {mu}m independent of refractive index.

Prakash, S.S. [New Mexico Univ., Albuquerque, NM (United States); Brinker, C.J. [New Mexico Univ., Albuquerque, NM (United States)]|[Sandia National Labs., Albuquerque, NM (United States); Hurd, A.J. [Sandia National Labs., Albuquerque, NM (United States)

1994-12-31T23:59:59.000Z

85

Thermal springs in the Salmon River basin, central Idaho  

DOE Green Energy (OSTI)

The Salmon River basin within the study area occupies an area of approximately 13,000 square miles in central Idaho. Geologic units in the basin are igneous, sedimentary, and metamorphic rocks; however, granitic rocks of the Idaho batholith are predominant. Water from thermal springs ranges in temperature from 20.5/sup 0/ to 94.0/sup 0/ Celsius. The waters are slightly alkaline and are generally a sodium carbonate or bicarbonate type. Dissolved-solids concentrations are variable and range from 103 to 839 milligrams per liter. Estimated reservoir temperatures determined from the silicic acid-corrected silica, sodium-potassium-calcium, and sulfate-water isotope geothermometers range from 30/sup 0/ to 184/sup 0/ Celsius. Tritium concentrations in sampled thermal waters are near zero and indicate the waters are at least 100 years old. Stable-isotope data indicate it is unlikely that a single hot-water reservoir supplies hot springs in the basin. Thermal springs discharged at least 15,800 acre-feet of water in 1980. Associated convective heat flux is 2.7 x 10/sup 7/ calories per second.

Young, H.W.; Lewis, R.E.

1982-02-01T23:59:59.000Z

86

Synthesis of Monolithic Iron Incorporated Silica Aerogels by Ambient ...  

Science Conference Proceedings (OSTI)

With the Fe to Si molar ratio not exceeding 0.10, the bulk density of iron incorporated silica aerogels increased to 0.55g/cm3, while the porosity reduced to 76% ...

87

Definition: Geothermometry | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Geothermometry Jump to: navigation, search Dictionary.png Geothermometry Chemical geothermometers are used to estimate reservoir temperatures for most of the systems. The geothermometers are based on temperature- dependent, water-rock reactions which control the chemical and isotopic composition of the thermal water. This method is applicable only to hot-water systems because the common chemical constituents of thermal water (SiO2, Na, K, Ca, Mg, Cl, HCO3, and CO3) are soluble in liquid water but lack significant solubility in steam.[1] View on Wikipedia Wikipedia Definition Geothermobarometry is the science of measuring the previous pressure and temperature history of a metamorphic or intrusive igneous rocks.

88

Geothermal Literature Review At Teels Marsh Area (Shevenell, Et Al., 2008)  

Open Energy Info (EERE)

Teels Marsh Area (Shevenell, Et Al., 2008) Teels Marsh Area (Shevenell, Et Al., 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermal Literature Review At Teels Marsh Area (Shevenell, Et Al., 2008) Exploration Activity Details Location Teels Marsh Area Exploration Technique Geothermal Literature Review Activity Date Usefulness useful DOE-funding Unknown Notes In conjunction with field checking of the borate crusts, existing databases were consulted and a cold spring was found in the literature at Teels Marsh that had a geochemical analysis. Geothermometry from this analysis predicted anomalous subsurface temperatures of 192degrees C (Mg-corrected Na-K-Ca geothermometer) and 118degrees C (quartz geothermometer). References Lisa Shevenell, Mark Coolbaugh, Chris Sladek, Rick Zehner, Chris

89

Mesoporous-silica films, fibers, and powders by evaporation  

SciTech Connect

This invention pertains to surfactant-templated nanometer-scale porosity of a silica precursor solution and forming a mesoporous material by first forming the silica precursor solution into a preform having a high surface area to volume ratio, then rapid drying or evaporating a solvent from the silica precursor solution. The mesoporous material may be in any geometric form, but is preferably in the form of a film, fiber, powder or combinations thereof. The rapid drying or evaporation of solvent from the solution is accomplished by layer thinning, for example spin casting, liquid drawing, and liquid spraying respectively. Production of a film is by layer thinning, wherein a layer of the silica precursor solution is formed on a surface followed by removal of an amount of the silica precursor solution and leaving a geometrically thinner layer of the silica precursor solution from which the solvent quickly escapes via evaporation. Layer thinning may be by any method including but not limited to squeegeeing and/or spin casting. In powder formation by spray drying, the same conditions of fast drying exists as in spin-casting (as well as in fiber spinning) because of the high surface-area to volume ratio of the product. When a powder is produced by liquid spraying, the particles or micro-bubbles within the powder are hollow spheres with walls composed of mesoporous silica. Mesoporous fiber formation starts with a similar silica precursor solution but with an added pre-polymer making a pituitous mixture that is drawn into a thin strand from which solvent is evaporated leaving the mesoporous fiber(s).

Bruinsma, Paul J. (Kennewick, WA); Baskaran, Suresh (Kennewick, WA); Bontha, Jagannadha R. (Richland, WA); Liu, Jun (West Richland, WA)

1999-01-01T23:59:59.000Z

90

Silica Extraction at the Mammoth Lakes Geothermal Site  

DOE Green Energy (OSTI)

The purpose of this project is to develop a cost-effective method to extract marketable silica (SiO{sub 2}) from fluids at the Mammoth Lakes, California geothermal power plant. Marketable silica provides an additional revenue source for the geothermal power industry and therefore lowers the costs of geothermal power production. The use of this type of ''solution mining'' to extract resources from geothermal fluids eliminates the need for acquiring these resources through energy intensive and environmentally damaging mining technologies. We have demonstrated that both precipitated and colloidal silica can be produced from the geothermal fluids at Mammoth Lakes by first concentrating the silica to over 600 ppm using reverse osmosis (RO). The RO permeate can be used in evaporative cooling at the plant; the RO concentrate is used for silica and potentially other (Li, Cs, Rb) resource extraction. Preliminary results suggest that silica recovery at Mammoth Lakes could reduce the cost of geothermal electricity production by 1.0 cents/kWh.

Bourcier, W; Ralph, W; Johnson, M; Bruton, C; Gutierrez, P

2006-06-07T23:59:59.000Z

91

Controlled drug release from bifunctionalized mesoporous silica  

Science Conference Proceedings (OSTI)

Serial of trimethylsilyl-carboxyl bifunctionalized SBA-15 (TMS/COOH/SBA-15) have been studied as carriers for controlled release of drug famotidine (Famo). To load Famo with large capacity, SBA-15 with high content of carboxyl groups was successfully synthesized by one-pot synthesis under the assistance of KCl. The mesostructure of carboxyl functionalized SBA-15 (COOH/SBA-15) could still be kept even though the content of carboxyl groups was up to 57.2%. Increasing carboxyl content could effectively enhance the loading capacity of Famo. Compared with pure SBA-15, into which Famo could be hardly adsorbed, the largest drug loading capacity of COOH/SBA-15 could achieve 396.9 mg/g. The release of Famo from mesoporous silica was studied in simulated intestine fluid (SIF, pH=7.4). For COOH/SBA-15, the release rate of Famo decreased with narrowing pore size. After grafting TMS groups on the surface of COOH/SBA-15 with hexamethyldisilazane, the release of Famo was greatly delayed with the increasing content of TMS groups. - Graphical abstract: Trimethylsilyl-carboxyl bifunctionalized SBA-15 has been studied as carrier for controlled release of drug famotidine. To load drug with large capacity, SBA-15 with high content of carboxyl groups was successfully synthesized. After grafting trimethylsilyl groups on the surface of carboxyl functionalized SBA-15, the release of Famo was greatly delayed with the increasing content of TMS groups.

Xu Wujun; Gao Qiang [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Xu Yao [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)], E-mail: xuyao@sxicc.ac.cn; Wu Dong; Sun Yuhan [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Shen Wanling [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Deng Feng [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

2008-10-15T23:59:59.000Z

92

Silica gel sorption properties under adiabatic conditions  

DOE Green Energy (OSTI)

The SERI Sorption Test Facility was modified from isothermal operation to adiabatic operating conditions so that we could measure the adsorption/desorption characteristics of silica-gel-coated, parallel-channel geometry as a function of operating conditions and aspect ratio under adiabatic conditions. We performed single-blow experiments on two single-passage test cells with different aspect ratios, air flow rates, and inlet conditions. Both adsorption and desorption runs were performed. As the air flow rate and aspect ratio increase when other parameters are kept constant, the desiccant matrix loses its sorption capacity faster. The test cell operated near isothermal conditions rather than adiabatically because the cell walls had a large thermal mass compared with the amount of desiccant used. Since constructing single-passage test cells with small thermal masses that can be operated adiabatically at the Sorption Test Facility is difficult, further testing at this facility will be primarily for isothermal operation. The adiabatic experiments can best be done with multipassage test cells having small thermal masses relative to desiccant mass. A single-blow test facility for performing experiments with multipassage test cells was fabricated in FY 1984, and experiments were performed in an FY 1985 desiccant project.

Pesaran, A.A.; Choudhury, K.

1986-02-01T23:59:59.000Z

93

Silica recovery and control in Hawaiian geothermal fluids  

DOE Green Energy (OSTI)

A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

Thomas, D.M.

1992-06-01T23:59:59.000Z

94

Silica recovery and control in Hawaiian geothermal fluids. Final report  

DOE Green Energy (OSTI)

A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

Thomas, D.M.

1992-06-01T23:59:59.000Z

95

Field study of tracer and geochemistry behavior during hydraulic fracturing of a hot dry rock geothermal reservoir  

DOE Green Energy (OSTI)

This study presents tracer and geochemistry data from several hydraulic fracturing experiments at the Fenton Hill, NM, HDR geothermal reservoir. Tracers have been injected at various times during these tests: (1) initially, before any flow communication existed between the wells; (2) shortly after a flow connection was established; and (3) after the outlet flow had increased to its steady state value. An idealized flow model consisting of a combination of main fracture flow paths and fluid leakoff into secondary permeability explains the different tracer response curves for these cases, and allows us to predict the fracture volume of the main paths. The geochemistry during these experiments supports our previously developed models postulating the existence of a high concentration indigenous ''pore fluid.'' Also, the quartz and Na-K-Ca geothermometers have been used successfully to identify the temperatures and depths at which fluid traveled while in the reservoir. The quartz geothermometer is somewhat more reliable because at these high temperatures (about 250/sup 0/C) the injected fluid can come to equilibrium with quartz in the reservoir. The Na-K-Ca geothermometer relies on obtaining a sample of the indigenous pore fluid, and thus is somewhat susceptible to problems of dilution with the injection fluid. 14 refs., 6 figs., 1 tab.

Robinson, B.A.

1986-01-01T23:59:59.000Z

96

Low-temperature geothermal assessment of the Santa Clara and Virgin River Valleys, Washington County, Utah  

DOE Green Energy (OSTI)

Exploration techniques included the following: (1) a temperature survey of springs, (2) chemical analyses and calculated geothermometer temperatures of water samples collected from selected springs and wells, (3) chemical analyses and calculated geothermometer temperatures of spring and well water samples in the literature, (4) thermal gradients measured in accessible wells, and (5) geology. The highest water temperature recorded in the St. George basin is 42/sup 0/C at Pah Tempe Hot Springs. Additional spring temperatures higher than 20/sup 0/C are at Veyo Hot Spring, Washington hot pot, and Green Spring. The warmest well water in the study area is 40/sup 0/C in Middleton Wash. Additional warm well water (higher than 24.5/sup 0/C) is present north of St. George, north of Washington, southeast of St. George, and in Dameron Valley. The majority of the Na-K-Ca calculated reservoir temperatures range between 30/sup 0/ and 50/sup 0/C. Anomalous geothermometer temperatures were calculated for water from Pah Tempe and a number of locations in St. George and vicinity. In addition to the known thermal areas of Pah Tempe and Veyo Hot Spring, an area north of Washington and St. George is delineated in this study to have possible low-temperature geothermal potential.

Budding, K.E.; Sommer, S.N.

1986-01-01T23:59:59.000Z

97

Silica-polystyrene nanocomposite particles synthesized by nitroxide-mediated polymerization and their encapsulation through miniemulsion polymerization  

Science Conference Proceedings (OSTI)

Polystyrene (PS) chains with molecular weights comprised between 8000 and 64000 g?mol-1and narrow polydispersities were grown from the surface of silica nanoparticles (Aerosil A200 fumed silica and Stöber silica, resp.) through nitroxide-mediated ...

Bérangère Bailly; Anne-Carole Donnenwirth; Christèle Bartholome; Emmanuel Beyou; Elodie Bourgeat-Lami

2006-01-01T23:59:59.000Z

98

Molecular oxygen sensors based on photoluminescent silica aerogels  

NLE Websites -- All DOE Office Websites (Extended Search)

Molecular oxygen sensors based on photoluminescent silica aerogels Molecular oxygen sensors based on photoluminescent silica aerogels Title Molecular oxygen sensors based on photoluminescent silica aerogels Publication Type Journal Article Year of Publication 1998 Authors Ayers, Michael R., and Arlon J. Hunt Journal Journal of Non-Crystalline Solids Volume 225 Pagination 343-347 Keywords aerogel, air pressure, oxygen concentration, oxygen molecules, photoluminescence Abstract Photoluminescent silica aerogel acts as the active element of an optical sensor for molecular oxygen. The luminescent aerogel is prepared by the action of energized reducing gases on a standard silica aerogel. Intensity of aerogel photoluminescence decreases as the collision frequency between oxygen molecules and the luminescent carriers in the aerogel matrix increases. This behavior is a characteristic of many photoluminescent materials and arises from a transfer of energy from the aerogel to surrounding oxygen molecules. A sensor for oxygen concentration or air pressure can therefore be simply constructed utilizing an ultraviolet source for excitation and a suitable detector for the emitted visible signal. Stern-Volmer quenching constants for the aerogel sensing element are 1.55×10-2 Torr-1 for hydrophilic aerogel and 2.4×10-3 Torr-1 for hydrophobic aerogel.

99

Methods to quantify contamination effects on silica gel samples  

DOE Green Energy (OSTI)

This report describes a study to establish methods for measuring sorption degradation of contaminated solid desiccants and determining the identity and nature of the contaminants. A literature search was conducted to determine how contaminants affect the sorption properties of silica gel and advanced solid desiccant materials; the search yielded 73 papers. Silica gel was chosen for the contamination study; nine samples from various batches and suppliers were tested. Methods were established (1) to measure the degradation of desiccant adsorption capacity caused by regeneration processes and/or exposure to contaminants and (2) to determine the nature of these contaminants. Sorption measurements on a limited number of fresh silica gel samples showed that the water adsorption capacity varied about +-10%. The silica gel sample regenerated with electric heaters exhibited a maximum capacity degradation of 7%. Silica gel samples processed in other ways lost between 20% and 47% capacity, depending on the age and cycle of regeneration. The contaminants found were silicon, oxygen, carbon, and nitrogen using x-ray photoelectron spectroscopy. Contamination can degrade the water sorption capacity of desiccants.

Pesaran, A.A.; Thomas, T.M.; Penney, T.R.; Czanderna, A.W.

1986-09-01T23:59:59.000Z

100

Kinetics of silica deposition from simulated geothermal brines  

DOE Green Energy (OSTI)

Supersaturated brines were passed through columns packed with several forms of silica (crystalline ..cap alpha.. quartz, polycrystalline ..cap alpha.. quartz, and porous Vycor). Also, silica deposition on ThO/sub 2/ microspheres and titanium powder was studied under controlled conditions of supersaturation, pH, temperature, and salinity. The residence time was varied by adjustments of flow rate and column length. The silica contents of the input and effluent solutions were determined colorimetrically by a molybdate method which does not include polymers without special pretreatment. Essentially identical deposition behavior was observed once the substrate was thoroughly coated with amorphous silica and the BET surface area of the coated particles was taken into account. The reaction rate is not diffusion limited in the columns. The silica deposition is a function of the monomeric Si(OH)/sub 4/ concentration in the brine. The deposition on all surfaces examined was spontaneously nucleated. The dependence on the supersaturation concentration, hydroxide ion concentration, surface area, temperature and salinity were examined. Fluoride was shown to have no effect at pH 5.94 and low salinity. The empirical rate law which describes the data in 1 m NaCl in the pH range 5-7 and temperatures from 60 to 120/sup 0/C is given.

Bohlmann, E.G.; Mesmer, R.E.; Berlinski, P.

1980-03-01T23:59:59.000Z

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101

FIRST LABORATORY OBSERVATION OF SILICA GRAINS FROM CORE COLLAPSE SUPERNOVAE  

SciTech Connect

We report the discovery of two supernova silica (SiO{sub 2}) grains in the primitive carbonaceous chondrites LaPaZ 031117 and Grove Mountains 021710. Only five presolar silica grains have been previously reported from laboratory measurements but they all exhibit enrichments in {sup 17}O relative to solar, indicating origins in the envelopes of asymptotic giant branch stars. The two SiO{sub 2} grains identified in this study are characterized by moderate enrichments in {sup 18}O relative to solar, indicating that they originated in Type II supernova ejecta. If compared to theoretical models, the oxygen isotopic compositions of these grains can be reproduced by mixing of different supernova zones. While both theoretical models of grain condensation and recent NASA Spitzer Space Telescope observations have suggested the presence of silica in supernova ejecta, no such grains had been identified, until now, in meteorites. The discovery of these two silica grains provides definitive evidence of the condensation of silica dust in supernova ejecta.

Haenecour, Pierre; Floss, Christine; Zinner, Ernst [Laboratory for Space Sciences, McDonnell Center for the Space Sciences and Physics Department, Washington University, One Brookings Drive, St. Louis, MO 63130-4899 (United States); Zhao Xuchao; Lin Yangting, E-mail: haenecour@wustl.edu [Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China)

2013-05-01T23:59:59.000Z

102

Dewetting of silica surfaces upon reactions with supercritical CO2 and brine: Pore-scale studies in micromodels  

E-Print Network (OSTI)

Influence of Compressed Carbon Dioxide on the Capillarity ofof supercritical carbon dioxide on silica. Langmuir 2001,Silica Surfaces and the Carbon Dioxide Molecule. J Phys Chem

Kim, Y.

2013-01-01T23:59:59.000Z

103

Silica membranes for hydrogen separation from coal gas. Final report  

DOE Green Energy (OSTI)

This project is a continuation of a previous DOE-UCR project (DE-FG22- 89PC89765) dealing with the preparation of silica membranes highly permselective to hydrogen at elevated temperatures, suitable for hydrogen separation from coal gas. The membranes prepared in the previous project had very high selectivity but relatively low permeance. Therefore, the general objectives of this project were to improve the permeance of these membranes and to obtain fundamental information about membrane structure and properties. The specific objectives were: (1) to explore new silylation reagents and reaction conditions with the purpose of reducing the thickness and increasing the permeance of silica membranes prepared by chemical vapor deposition (CVD), (2) to characterize the membrane structure, (3) to delineate mechanism and kinetics of deposition, (4) to measure the permeability of silica layers at different extents of deposition, and (5) to mathematically model the relationship between structure and deposition kinetics.

Gavalas, G.R.

1996-01-01T23:59:59.000Z

104

The dissociation of liquid silica at high pressure and temperature  

Science Conference Proceedings (OSTI)

Liquid silica at high pressure and temperature is shown to undergo significant structural modifications and profound changes in its electronic properties. Temperature measurements on shock waves in silica at 70-1000 GPa indicate that the specific heat of liquid SiO{sub 2} rises well above the Dulong-Petit limit, exhibiting a broad peak with temperature that is attributable to the growing structural disorder caused by bond-breaking in the melt. The simultaneous sharp rise in optical reflectivity of liquid SiO{sub 2} indicates that dissociation causes the electrical and therefore thermal conductivities of silica to attain metallic-like values of 1-5 x 10{sup 5} S/m and 24-600 W/m.K respectively.

Hicks, D; Boehly, T; Eggert, J; Miller, J; Celliers, P; Collins, G

2005-11-17T23:59:59.000Z

105

PATCHY SILICA-COATED SILVER NANOWIRES AS SERS SUBSTRATES  

SciTech Connect

We report a class of core-shell nanomaterials that can be used as efficient surface-enhancement Raman scattering (SERS) substrates. The core consists of silver nanowires, prepared through a chemical reduction process, that are used to capture 4- mercaptobenzoic acid (4-MBA), a model analyte. The shell was prepared through a modified Stöber method and consists of patchy or full silica coats. The formation of silica coats was monitored via transmission electron microscopy, UV-visible spectroscopy and phase-analysis light scattering for measuring effective surface charge. Surprisingly, the patchy silica coated silver nanowires are better SERS substrate than silver nanowires; nanomolar concentration of 4-MBA can be detected. In addition, “nano-matryoshka” configurations were used to quantitate/explore the effect of the electromagnetic field at the tips of the nanowire (“hot spots”) in the Raman scattering experiment.

Murph, S.; Murphy, C.

2013-03-29T23:59:59.000Z

106

Electrospinning of silica nanofibers: characterization and application to biosensing  

E-Print Network (OSTI)

Electrospinning is a technique to achieve nanometer scale fibers. Similar to the conventional spin methods of making fabric, the viscous polymer solution is ejected from a spinneret; stretched and solidified in the air, the solution forms the fibers. The different part of electrospinning among others is that the fibers are driven by the electrostatic force, which induces the repulsion inside the liquid and further reduces the diameter. The resultant product is a non-woven membrane, which is porous; and the pore size is around several nanometers to a micrometer wide. In this work, the relationship between the diameter of electrospun silica fibers, experimental parameters such as concentration and voltage, and between pore size of the fiber membrane and experimental time were studied. Materials used in the process are Polyvinylpyrrolidone (PVP), butanol and spin-on-glass coating solution, which act as polymer carrier, solvent, and silica-precursor, respectively. Polymer/silica precursor composite fibers were ejected from the needle of a plastic syringe when an electrical field, as high as several kV/cm, was applied. Then silica fibers were achieved by baking the composite ones at 773 oK for 12 h. Electrospun silica nanofibers were characterized as a function of polymer solution parameters. The calcined fibers were examined by using a field emission scanning electron microscope. The results showed that the fiber diameters decrease with decreasing proportion of polymer and silica precursor, and increase with a higher electric field. Pore sizes, defined as the grid areas enclosed by fibers on nearby layers, were also examined and showed no time-dependent tendency when the electrospin time was between 1-5 min. Fiber membranes were then used as the platform for protein detection. The results were compared with the control, which used glass slides as the platform. The results make it possible to make a more sensitive biosensing device.

Tsou, Pei-Hsiang

2006-08-01T23:59:59.000Z

107

Potential Health Effects of Crystalline Silica Exposures from Coal Fly Ash: A Literature Review  

Science Conference Proceedings (OSTI)

The amount of crystalline silica in coal fly ash (CFA) depends on a variety of factors, including the amount of silica in the pre-combustion coal, the combustion process, and emission control technologies among others. Occupational exposures to crystalline silica in CFA are related to these factors as well as activities associated with exposures and durations of exposure. This review summarizes the occupational and environmental health literature relevant to the presence of crystalline silica in CFA from...

2006-03-27T23:59:59.000Z

108

Analysis of the elastic behaviour of silica aerogels taken as a percolating system  

E-Print Network (OSTI)

289 Analysis of the elastic behaviour of silica aerogels taken as a percolating system T. Woignier of silica aerogels are performed using the three points flexural technique. The elastic behaviour is studied measurement - for silica aerogels. These highly porous materials are obtained from a sol-gel process. Solvent

Paris-Sud XI, Université de

109

Capacity degradation of field-tested silica gel samples  

DOE Green Energy (OSTI)

Researchers at the Solar Energy Research Institute (SERI) have begun preliminary studies to quantify the effect of contamination of silica gel used in dehumidification processes of desiccant cooling systems. Sorption capacity degradation of field tested samples was measured, and the source of degradation was quantified using surface analysis experimental methods.

Penney, T.R.; Pesaran, A.A.; Thomas, T.M.

1985-06-01T23:59:59.000Z

110

Fractal Studies on Titanium-Silica Aerogels using SMARTer  

SciTech Connect

Power-law scattering approximation has been employed to reveal the fractal structures of solid-state titanium-silica aerogel samples. All small-angle neutron scattering (SANS) measurements were performed using 36 meters SANS BATAN spectrometer (SMARTer) at the neutron scattering laboratory (NSL) in Serpong, Indonesia. The mass fractal dimension of titanium-silica aerogels at low scattering vector q range increases from -1.4 to -1.92 with the decrease of acid concentrations during sol-gel process. These results are attributed to the titanium-silica aerogels that are growing to more polymeric and branched structures. At high scattering vector q range the Porod slope of -3.9 significantly down to -2.24 as the roughness of particle surfaces becomes higher. The cross over between these two regimes decreases from 0.4 to 0.16 nm{sup -1} with the increase of acid concentrations indicating also that the titanium-silica aerogels are growing.

Putra, E. Giri Rachman; Ikram, A.; Bharoto; Santoso, E. [Neutron Scattering Laboratory, BATAN, Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia); Fang, T. Chiar; Ibrahim, N. [Department of Physics, Faculty of Science Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor (Malaysia); Mohamed, A. Aziz [Materials Technology Group, Industrial Technology Division Agensi Nuklear Malaysia, 43000 Kajang (Malaysia)

2008-03-17T23:59:59.000Z

111

High temperature thermographic measurements of laser heated silica  

SciTech Connect

In situ spatial and temporal surface temperature profiles of CO{sub 2} laser-heated silica were obtained using a long wave infrared (LWIR) HgCdTe camera. Solutions to the linear diffusion equation with volumetric and surface heating are shown to describe the temperature evolution for a range of beam powers, over which the peak surface temperature scales linearly with power. These solutions were used with on-axis steady state and transient experimental temperatures to extract thermal diffusivity and conductivity for a variety of materials, including silica, spinel, sapphire, and lithium fluoride. Experimentally-derived thermal properties agreed well with reported values and, for silica, thermal conductivity and diffusivity are shown to be approximately independent of temperature between 300 and 2800K. While for silica our analysis based on a temperature independent thermal conductivity is shown to be accurate, for other materials studied this treatment yields effective thermal properties that represent reasonable approximations for laser heating. Implementation of a single-wavelength radiation measurement in the semi-transparent regime is generally discussed, and estimates of the apparent temperature deviation from the actual outer surface temperature are also presented. The experimental approach and the simple analysis presented yield surface temperature measurements that can be used to validate more complex physical models, help discriminate dominant heat transport mechanisms, and to predict temperature distribution and evolution during laser-based material processing.

Elhadj, S; Yang, S T; Matthews, M J; Cooke, D J; Bude, J D; Johnson, M; Feit, M; Draggoo, V; Bisson, S E

2009-11-02T23:59:59.000Z

112

Fabrication of magnetite/silica/titania core-shell nanoparticles  

Science Conference Proceedings (OSTI)

Fe3O4/SiO2/TiO2 core-shell nanoparticles were synthesized via a sol-gel method with the aid of sonication. Fe3O4 nanoparticles were being encapsulated within discrete silica nanospheres, ...

Suh Cem Pang; Sze Yun Kho; Suk Fun Chin

2012-01-01T23:59:59.000Z

113

Coagulation chemistries for silica removal from cooling tower water.  

SciTech Connect

The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

2010-02-01T23:59:59.000Z

114

Flue gas injection control of silica in cooling towers.  

Science Conference Proceedings (OSTI)

Injection of CO{sub 2}-laden flue gas can decrease the potential for silica and calcite scale formation in cooling tower blowdown by lowering solution pH to decrease equilibrium calcite solubility and kinetic rates of silica polymerization. Flue gas injection might best inhibit scale formation in power plant cooling towers that use impaired makeup waters - for example, groundwaters that contain relatively high levels of calcium, alkalinity, and silica. Groundwaters brought to the surface for cooling will degas CO{sub 2} and increase their pH by 1-2 units, possibly precipitating calcite in the process. Recarbonation with flue gas can lower the pHs of these fluids back to roughly their initial pH. Flue gas carbonation probably cannot lower pHs to much below pH 6 because the pHs of impaired waters, once outgassed at the surface, are likely to be relatively alkaline. Silica polymerization to form scale occurs most rapidly at pH {approx} 8.3 at 25 C; polymerization is slower at higher and lower pH. pH 7 fluids containing {approx}220 ppm SiO{sub 2} require > 180 hours equilibration to begin forming scale whereas at pH 8.3 scale formation is complete within 36 hours. Flue gas injection that lowers pHs to {approx} 7 should allow substantially higher concentration factors. Periodic cycling to lower recoveries - hence lower silica concentrations - might be required though. Higher concentration factors enabled by flue gas injection should decrease concentrate volumes and disposal costs by roughly half.

Brady, Patrick Vane; Anderson, Howard L., Jr.; Altman, Susan Jeanne

2011-06-01T23:59:59.000Z

115

Plutonium complexation by phosphonate-functionalized mesoporous silica  

Science Conference Proceedings (OSTI)

MCM-41-type mesoporous silica functionalized with the CMPO-based 'Ac-Phos' silane has been reported in the literature (1) to show good capacity as an acftinide sorbent material, with potential applications in environmental sequestration, aqueous waste separation and/or vitrification, and chemical sensing of actinides in solution. The study explores the complexation of Pu(IV and VI) and other selected actinides and lanthanides by SBA-15 type mesoporous silica functionalized with Ac-Phos. The Pu binding kinetics and binding capacity were determined for both the Ac-Phos functionalized and unmodified SBA-15. They analyzed the binding geometry and redox behavior of Pu(VI) by X-ray absorption spectroscopy (XAS). They discuss the synthesis and characterization of the functionalized mesoporous material, batch sorption experiments, and the detailed analyses of the actinide complexes that are formed. Structural measurements are paired with high-level quantum mechanical modeling to elucidate the binding mechanisms.

Parsons-Moss, T; Schwaiger, L K; Hubaud, A; Hu, Y J; Tuysuz, H; Yang, P; Balasubramanian, K; Nitsche, H

2010-10-27T23:59:59.000Z

116

Method for dissolution and stabilization of silica-rich fibers  

DOE Patents (OSTI)

This invention is comprised of a method for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters.

Jantzen, C.M.

1992-12-31T23:59:59.000Z

117

Laser supported solid state absorption fronts in silica  

SciTech Connect

We develop a model based on simulation and experiment that explains the behavior of solid-state laser-supported absorption fronts generated in fused silica during high intensity (up to 5GW/cm{sup 2}) laser exposure. We find that the absorption front velocity is constant in time and is nearly linear in laser intensity. Further, this model can explain the dependence of laser damage site size on these parameters. This behavior is driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. The regime of parameter space critical to this problem spans and extends that measured by other means. It serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.

Carr, C W; Bude, J D

2010-02-09T23:59:59.000Z

118

Method for dissolution and stabilization of silica-rich fibers  

DOE Patents (OSTI)

A method is described for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters. 1 fig.

Jantzen, C.M.

1997-11-11T23:59:59.000Z

119

Molecular engineering of porous silica using aryl templates  

DOE Patents (OSTI)

A process is described for manipulating the porosity of silica using a series of organic template groups covalently incorporated into the silicate matrix. The templates in the bridged polysilsesquioxanes are selectively removed from the material by oxidation with oxygen plasma or other means, leaving engineered voids or pores. The size of these pores is dependent upon the length or size of the template or spacer. The size of the templates is measured in terms of Si-Si distances which range from about 0.67 nm to 1.08 nm. Changes introduced by the loss of the templates result in a narrow range of micropores (i.e. <2 nm). Both aryl and alkyl template groups are used as spacers. Novel microporous silica materials useful as molecular sieves, desiccants, and catalyst supports are produced. 3 figs.

Loy, D.A.; Shea, K.J.

1994-06-14T23:59:59.000Z

120

Molecular engineering of porous silica using aryl templates  

SciTech Connect

A process for manipulating the porosity of silica using a series of organic template groups covalently incorporated into the silicate matrix. The templates in the bridged polysilsesquioxanes are selectively removed from the material by oxidation with oxygen plasma or other means, leaving engineered voids or pores. The size of these pores is dependent upon the length or size of the template or spacer. The size of the templates is measured in terms of Si-Si distances which range from about 0.67 nm to 1.08 nm. Changes introduced by the loss of the templates result in a narrow range of micropores (i.e. <2 nm). Both aryl and alkyl template groups are used as spacers. Novel microporous silica materials useful as molecular seives, dessicants, and catalyst supports are produced.

Loy, Douglas A. (Albuquerque, NM); Shea, Kenneth J. (Irvine, CA)

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Fluorescent Functionalized Mesoporous Silica for Radioactive Material Extraction  

Science Conference Proceedings (OSTI)

Mesoporous silica with covalently bound salicylic acid molecules incorporated in the structure was synthesized with a one-pot, co-condensation reaction at room temperature. The as-synthesized material has a large surface area, uniform particle size, and an ordered pore structure as determined by characterization with transmission electron microscopy, thermal gravimetric analysis, and infrared spectra, etc. Using the strong fluorescence and metal coordination capability of salicylic acid, functionalized mesoporous silica (FMS) was developed to track and extract radionuclide contaminants, such as uranyl [U(VI)] ions encountered in subsurface environments. Adsorption measurements showed a strong affinity of the FMS toward U(VI) with a Kd value of 105 mL/g, which is four orders of magnitude higher than the adsorption of U(VI) onto most of the sediments in natural environments. The new materials have a potential for synergistic environmental monitoring and remediation of the radionuclide U(VI) from contaminated subsurface environments.

Li, Juan; Zhu, Kake; Shang, Jianying; Wang, Donghai; Nie, Zimin; Guo, Ruisong; Liu, Chongxuan; Wang, Zheming; Li, Xiaolin; Liu, Jun

2012-08-01T23:59:59.000Z

122

Functionalized bimodal mesoporous silicas as carriers for controlled aspirin delivery  

Science Conference Proceedings (OSTI)

The bimodal mesoporous silica modified with 3-aminopropyltriethoxysilane was performed as the aspirin carrier. The samples' structure, drug loading and release profiles were characterized with X-ray diffraction, scanning electron microscopy, N{sub 2} adsorption and desorption, Fourier transform infrared spectroscopy, TG analysis, elemental analysis and UV-spectrophotometer. For further exploring the effects of the bimodal mesopores on the drug delivery behavior, the unimodal mesoporous material MCM-41 was also modified as the aspirin carrier. Meantime, Korsmeyer-Peppas equation f{sub t}=kt{sup n} was employed to analyze the dissolution data in details. It is indicated that the bimodal mesopores are beneficial for unrestricted drug molecules diffusing and therefore lead to a higher loading and faster releasing than that of MCM-41. The results show that the aspirin delivery properties are influenced considerably by the mesoporous matrix, whereas the large pore of bimodal mesoporous silica is the key point for the improved controlled-release properties. - Graphical abstract: Loading (A) and release profiles (B) of aspirin in N-BMMs and N-MCM-41 indicated that BMMs have more drug loading capacity and faster release rate than that MCM-41. Highlights: > Bimodal mesoporous silicas (BMMs) and MCM-41 modified with amino group via post-treatment procedure. > Loading and release profiles of aspirin in modified BMMs and MCM-41. > Modified BMMs have more drug loading capacity and faster release rate than that modified MCM-41.

Gao Lin [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Sun Jihong, E-mail: jhsun@bjut.edu.cn [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Li Yuzhen [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

2011-08-15T23:59:59.000Z

123

Silica aerogel: An intrinsically low dielectric constant material  

Science Conference Proceedings (OSTI)

Silica aerogels are highly porous solids having unique morphologies in wavelength of visible which both the pores and particles have sizes less than the wavelength of visible light. This fine nanostructure modifies the normal transport mechanisms within aerogels and endows them with a variety of exceptional physical properties. For example, aerogels have the lowest measured thermal conductivity and dielectric constant for any solid material. The intrinsically low dielectric properties of silica aerogels are the direct result of the extremely high achievable porosities, which are controllable over a range from 75% to more than 99.8 %, and which result in measured dielectric constants from 2.0 to less than 1.01. This paper discusses the synthesis of silica aerogels, processing them as thin films, and characterizing their dielectric properties. Existing data and other physical characteristics of bulk aerogels (e.g., thermal stablity, thermal expansion, moisture adsorption, modulus, dielectric strength, etc.), which are useful for evaluating them as potential dielectrics for microelectronics, are also given.

Hrubesh, L.W.

1995-04-01T23:59:59.000Z

124

Multimodality Imaging with Silica-Based Targeted Nanoparticle Platforms  

SciTech Connect

Objectives: To synthesize and characterize a C-Dot silica-based nanoparticle containing 'clickable' groups for the subsequent attachment of targeting moieties (e.g., peptides) and multiple contrast agents (e.g., radionuclides with high specific activity) [1,2]. These new constructs will be tested in suitable tumor models in vitro and in vivo to ensure maintenance of target-specificity and high specific activity. Methods: Cy5 dye molecules are cross-linked to a silica precursor which is reacted to form a dye-rich core particle. This core is then encapsulated in a layer of pure silica to create the core-shell C-Dot (Figure 1) [2]. A 'click' chemistry approach has been used to functionalize the silica shell with radionuclides conferring high contrast and specific activity (e.g. 64Cu and 89Zr) and peptides for tumor targeting (e.g. cRGD and octreotate) [3]. Based on the selective Diels-Alder reaction between tetrazine and norbornene, the reaction is bioorthogonal, highyielding, rapid, and water-compatible. This radiolabeling approach has already been employed successfully with both short peptides (e.g. octreotate) and antibodies (e.g. trastuzumab) as model systems for the ultimate labeling of the nanoparticles [1]. Results: PEGylated C-Dots with a Cy5 core and labeled with tetrazine have been synthesized (d = 55 nm, zeta potential = -3 mV) reliably and reproducibly and have been shown to be stable under physiological conditions for up to 1 month. Characterization of the nanoparticles revealed that the immobilized Cy5 dye within the C-Dots exhibited fluorescence intensities over twice that of the fluorophore alone. The nanoparticles were successfully radiolabeled with Cu-64. Efforts toward the conjugation of targeting peptides (e.g. cRGD) are underway. In vitro stability, specificity, and uptake studies as well as in vivo imaging and biodistribution investigations will be presented. Conclusions: C-Dot silica-based nanoparticles offer a robust, versatile, and multi-functional platform to enhance in vivo detection sensitivity and non-invasively assay receptor expression/status of tumor cellular targets, including those of low abundance, using nuclear-NIR fluorescence imaging approaches [2]. Improvements in molecular diagnostics, refined by the availability of nanotechnology platforms, will be a key determinant in driving early-stage disease detection and prevention, ultimately leading to decreases in mortality.

Jason S. Lewis

2012-04-09T23:59:59.000Z

125

Preparation of silica stabilized biological templates for the production of metal and layered nanoparticles  

Science Conference Proceedings (OSTI)

The present invention relates to a system and method providing for increased silica growth on a bio-template, wherein the bio-template is pretreated with aniline to produce a uniform silica attractive surface and yielding a significant silica layers of at least 10 nm, and more preferably at least 20 nm in thickness, thereby providing for a high degree of stability to the bio-template.

Culver, James N; Royston, Elizabeth; Brown, Adam; Harris, Michael

2013-02-26T23:59:59.000Z

126

XAS of uranium(VI) sorbed onto silica, alumina, and montmorillonite  

Science Conference Proceedings (OSTI)

The purpose of this work is to determine the speciation (oxidation state and molecular structure) of uranium sorbed onto surfaces of silica

E. R. Sylwester; P. G. Allen; E. A. Hudson

2000-01-01T23:59:59.000Z

127

Synthesis and new structure shaping mechanism of silica particles formed at high pH  

SciTech Connect

For the sol-gel synthesis of silica particles under high pH catalytic conditions (pH>12) in water/ethanol solvent, we have deduced that the competing dynamics of chemical etching and sol-gel process can explain the types of silica particles formed and their morphologies. We have demonstrated that emulsion droplets that are generated by adding tetraethyl orthosilicate (TEOS) to a water-ethanol solution serve as soft templates for hollow spherical silica (1-2 {mu}m). And if the emulsion is converted by the sol-gel process, one finds that suspended solid silica spheres of diameter of {approx}900 nm are formed. Moreover, several other factors are found to play fundamental roles in determining the final morphologies of silica particles, such as by variation of the pH (in our case, using OH{sup -}) to a level where condensation dominates; by changing the volume ratios of water/ethanol; and using an emulsifier (specifically, CTAB) - Graphical abstract: 'Local chemical etching' and sol-gel process have been proposed to interpret the control of morphologies of silica particles through varying initial pHs in syntheses. Highlights: Black-Right-Pointing-Pointer Different initial pHs in our syntheses provides morphological control of silica particles. Black-Right-Pointing-Pointer 'Local chemical etching' and sol-gel process describes the formation of silica spheres. Black-Right-Pointing-Pointer The formation of emulsions generates hollow silica particles.

Zhang, Henan; Zhao, Yu [Department of Chemistry, The City College of The University of New York, 160 Convent Avenue, New York, NY 10031 (United States)] [Department of Chemistry, The City College of The University of New York, 160 Convent Avenue, New York, NY 10031 (United States); Akins, Daniel L., E-mail: akins@sci.ccny.cuny.edu [Department of Chemistry, The City College of The University of New York, 160 Convent Avenue, New York, NY 10031 (United States)

2012-10-15T23:59:59.000Z

128

Silica Exposure Assessment of Oil And Gas Drilling Workers During Hydraulic Fracking Process.  

E-Print Network (OSTI)

??The problem investigated in this study was that of identifying the silica exposure to the employees of an oil gas company during the fracking process… (more)

Li, Jigang

2011-01-01T23:59:59.000Z

129

Luminescent organosilicon polymers and sol-gel synthesis of nano-structured silica  

E-Print Network (OSTI)

sol-­?gel  synthesis  of  nano-­?structured  silica     by  a   Malvern  Zetasizer  Nano  series  instrument.  Zeta  of   aggregates   of   nano-­?C60.   Aquatic   Toxicol.  

Martinez, H. Paul

2011-01-01T23:59:59.000Z

130

Synthesis of Mesocellular Silica Foams with Tunable Window and Cell Dimensions  

E-Print Network (OSTI)

Polystyrene microspheres coated with cationic surfactants are easily prepared by micro- emulsion templates. These silica foams resemble dense aerogels. Introduction Because of their greatly enhanced pore

Yang, Peidong

131

Silicon Surface Texturing by Electro-Deoxidation of a Thin Silica ...  

Science Conference Proceedings (OSTI)

Presentation Title, Silicon Surface Texturing by Electro-Deoxidation of a Thin Silica Layer in Molten Salt. Author(s), Eimutis Juzeliunas, Antony Cox, Derek Fray

132

Cellular Effect of High Doses of Silica-Coated Quantum Dot ...  

Cellular Effect of High Doses of Silica-Coated Quantum Dot Profiled with High Throughput Gene Expression Analysis and High Content Cellomics ...

133

Thermal annealing of laser damage precursors on fused silica surfaces  

Science Conference Proceedings (OSTI)

Previous studies have identified two significant precursors of laser damage on fused silica surfaces at fluenes below {approx} 35 J/cm{sup 2}, photoactive impurities in the polishing layer and surface fractures. In the present work, isothermal heating is studied as a means of remediating the highly absorptive, defect structure associated with surface fractures. A series of Vickers indentations were applied to silica surfaces at loads between 0.5N and 10N creating fracture networks between {approx} 10{micro}m and {approx} 50{micro}m in diameter. The indentations were characterized prior to and following thermal annealing under various times and temperature conditions using confocal time-resolved photo-luminescence (CTP) imaging, and R/1 optical damage testing with 3ns, 355nm laser pulses. Significant improvements in the damage thresholds, together with corresponding reductions in CTP intensity, were observed at temperatures well below the glass transition temperature (T{sub g}). For example, the damage threshold on 05.N indentations which typically initiates at fluences 35 J/cm{sup 2} through the use of a {approx} 750 C thermal treatment. Larger fracture networks required longer or higher temperature treatment to achieve similar results. At an annealing temperature > 1100 C, optical microscopy indicates morphological changes in some of the fracture structure of indentations, although remnants of the original fracture and significant deformation was still observed after thermal annealing. This study demonstrates the potential of using isothermal annealing as a means of improving the laser damage resistance of fused silica optical components. Similarly, it provides a means of further understanding the physics associated with optical damage and related mitigation processes.

Shen, N; Miller, P E; Bude, J D; Laurence, T A; Suratwala, T I; Steele, W A; Feit, M D; Wang, L L

2012-03-19T23:59:59.000Z

134

Thermal annealing of laser damage precursors on fused silica surfaces  

SciTech Connect

Previous studies have identified two significant precursors of laser damage on fused silica surfaces at fluenes below {approx} 35 J/cm{sup 2}, photoactive impurities in the polishing layer and surface fractures. In the present work, isothermal heating is studied as a means of remediating the highly absorptive, defect structure associated with surface fractures. A series of Vickers indentations were applied to silica surfaces at loads between 0.5N and 10N creating fracture networks between {approx} 10{micro}m and {approx} 50{micro}m in diameter. The indentations were characterized prior to and following thermal annealing under various times and temperature conditions using confocal time-resolved photo-luminescence (CTP) imaging, and R/1 optical damage testing with 3ns, 355nm laser pulses. Significant improvements in the damage thresholds, together with corresponding reductions in CTP intensity, were observed at temperatures well below the glass transition temperature (T{sub g}). For example, the damage threshold on 05.N indentations which typically initiates at fluences <8 J/cm{sup 2} could be improved >35 J/cm{sup 2} through the use of a {approx} 750 C thermal treatment. Larger fracture networks required longer or higher temperature treatment to achieve similar results. At an annealing temperature > 1100 C, optical microscopy indicates morphological changes in some of the fracture structure of indentations, although remnants of the original fracture and significant deformation was still observed after thermal annealing. This study demonstrates the potential of using isothermal annealing as a means of improving the laser damage resistance of fused silica optical components. Similarly, it provides a means of further understanding the physics associated with optical damage and related mitigation processes.

Shen, N; Miller, P E; Bude, J D; Laurence, T A; Suratwala, T I; Steele, W A; Feit, M D; Wang, L L

2012-03-19T23:59:59.000Z

135

Optical and radiographical characterization of silica aerogel for Cherenkov radiator  

E-Print Network (OSTI)

We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying method enables us to produce highly transparent hydrophobic aerogels with high refractive index by shrinking wet-gels. In order to investigate the uniformity in the density (i.e., refractive index) of an individual aerogel monolith, we use the laser Fraunhofer method, an X-ray absorption technique, and Cherenkov imaging by a ring imaging Cherenkov detector in a beam test. We observed an increase in density at the edge of the aerogel tiles, produced by pin-drying.

Tabata, Makoto; Hatakeyama, Yoshikiyo; Kawai, Hideyuki; Morita, Takeshi; Nishikawa, Keiko

2012-01-01T23:59:59.000Z

136

Measurement of Radiation Damage on Silica Aerogel \\v Cerenkov Radiator  

E-Print Network (OSTI)

We measured the radiation damage on silica aerogel \\v Cerenkov radiators originally developed for the $B$-factory experiment at KEK. Refractive index of the aerogel samples ranged from 1.012 to 1.028. The samples were irradiated up to 9.8~MRad of equivalent dose. Measurements of transmittance and refractive index were carried out and these samples were found to be radiation hard. Deteriorations in transparency and changes of refractive index were observed to be less than 1.3\\% and 0.001 at 90\\% confidence level, respectively. Prospects of using aerogels under high-radiation environment are discussed.

S. K. Sahu et al

1996-04-11T23:59:59.000Z

137

Preparation of silica aerogels with improved mechanical properties and extremely low thermal conductivities through modified sol-gel process  

E-Print Network (OSTI)

Reported silica aerogels have a thermal conductivity as low as 15 mW/mK. The fragility of silica aerogels, however, makes them impractical for structural applications. The purpose of the study is to improve the ductility ...

Zuo, Yanjia

2010-01-01T23:59:59.000Z

138

Synthesis of silica nanoparticles by sol-gel: size-dependent properties, surface modification, and applications in silica-polymer nanocomposites — a review  

Science Conference Proceedings (OSTI)

Application of silica nanoparticles as fillers in the preparation of nanocomposite of polymers has drawnmuch attention, due to the increased demand for new materials with improved thermal, mechanical, physical, and chemical properties. Recent developments ...

Ismail Ab Rahman; Vejayakumaran Padavettan

2012-01-01T23:59:59.000Z

139

Electrochromic nanocomposite of silica/polyaniline prepared from a water-in-oil microemulsion solution  

Science Conference Proceedings (OSTI)

A composite nanoparticle of silica/polyaniline was synthesized from a microemulsion and it was tested as an electrochromic film. The compositions for the stable microemulsion system was selected as 65.4 wt% cyclohexane, 30.4 wt% surfactant and 4.2 wt% ... Keywords: electrochromic, inorganic-organic hybrid, nanoparticle, operation life time, polyaniline, silica

Taejin Hwang; Heung Yeol Lee; Hohyeong Kim; Gyuntak Kim

2010-11-01T23:59:59.000Z

140

Young's modulus evaluation by SAWs for porous silica low-k film with cesium doping  

Science Conference Proceedings (OSTI)

Young's moduli of porous silica low-k films with cesium (Cs) doping are determined by surface acoustic waves (SAWs) in this study. Four low-k samples doped with 0-30ppmwt% Cs in the precursor solution are investigated to check the mechanical promotion ... Keywords: Cesium doping, Low-k film, Porous silica, Surface acoustic waves, Young's modulus

X. Xiao; X. M. Shan; Y. Kayaba; K. Kohmura; H. Tanaka; T. Kikkawa

2011-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Mechanism of silica precipitation by lowering pH in chemi-thermomechanical pulping black liquors  

Science Conference Proceedings (OSTI)

Black liquor is a complex colloidal system obtained by chemical pulping process. It comprises of lignin, nearly 50% of the total organic and Silica approx. 2-3% (OD basis) of the total inorganic components. Black liquor is fed to chemical recovery plant ... Keywords: black liquors, desilication and concentrators, lignin, silica

Muhammad Ikram Aujla; Ishtiaq-Ur-Rehman Ishtiaq-Ur-Rehman; Asad Javaid

2007-12-01T23:59:59.000Z

142

Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky*  

E-Print Network (OSTI)

Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Vapors Jiangquan time-domain spectroscopy (THz-TDS) study of hydrophobic and hydrophilic silica aerogels, and the adsorption of several molecular vapors in the hydrophilic silica aerogel. The hydrophobic and hydrophilic

Oklahoma State University

143

Geology, characteristics, and resource potential of the low-temperature geothermal system near Midway, Wasatch County, Utah. Report of Investigation No. 142  

DOE Green Energy (OSTI)

To evaluate the geothermal energy potential of the hot springs system near Midway, Wasatch Co., Utah, consideration was given to heat flow, water chemistry, and structural controls. Abnormal heat flow was indicated qualitatively by snow-melt patterns and quantitatively by heat-flow measurements that were obtained from two of four temperature-gradient wells drilled in the area. These measurements indicated that the area north of the town of Midway is characterized by heat flow equal to 321.75 MW/m/sup 2/, which is over four times the value generally considered as normal heat flow. Chemical analyses of water from six selected thermal springs and wells were used in conjunction with the silica and Na-K-Ca geothermometers to estimate the reservoir temperature of the thermal system. Because the calculated temperature was more than 25/sup 0/C above the maximum observed temperature, a mixing model calculation was used to project an upper limit for the reservoir temperature. Based on these calculations, the system has a reservoir temperature ranging from 46 to 125/sup 0/C. Structural information obtained from published geologic maps of the area and from an unpublished gravity survey, enabled two models to be developed for the system. The first model, based on geologic relationships in the mountains to the north and west of Midway, assumes that the heat for the thermal system comes from a relatively young intrusive or related hydrothermal convection system in the vicinity of the Mayflower mine. Meteoric waters would be heated as they approach the heat source and then move laterally to the south through faults and fractures in the rocks. These thermal waters then rise to the surface through fractures in the crest of an anticline underneath the Midway area. The second model, based on the gravity survey, assumes an igneous intrusion directly beneath Midway as the heat source.

Kohler, J.F.

1979-06-01T23:59:59.000Z

144

Encapsulated in silica: genome, proteome and physiology of the thermophilic bacterium Anoxybacillus flavithermus  

SciTech Connect

Gram-positive bacteria of the genus Anoxybacillus have been found in diverse thermophilic habitats, such as geothermal hot springs and manure, and in processed foods such as gelatin and milk powder. Anoxybacillus flavithermus is a facultatively anaerobic bacterium found in super-saturated silica solutions and in opaline silica sinter. The ability of A. flavithermus to grow in super-saturated silica solutions makes it an ideal subject to study the processes of sinter formation, which might be similar to the biomineralization processes that occurred at the dawn of life. We report here the complete genome sequence of A. flavithermus strain WK1, isolated from the waste water drain at the Wairakei geothermal power station in New Zealand. It consists of a single chromosome of 2,846,746 base pairs and is predicted to encode 2,863 proteins. In silico genome analysis identified several enzymes that could be involved in silica adaptation and biofilm formation, and their predicted functions were experimentally validated in vitro. Proteomic analysis confirmed the regulation of biofilm-related proteins and crucial enzymes for the synthesis of long-chain polyamines as constituents of silica nanospheres. Microbial fossils preserved in silica and silica sinters are excellent objects for studying ancient life, a new paleobiological frontier. An integrated analysis of the A. flavithermus genome and proteome provides the first glimpse of metabolic adaptation during silicification and sinter formation. Comparative genome analysis suggests an extensive gene loss in the Anoxybacillus/Geobacillus branch after its divergence from other bacilli.

Saw, Jimmy H [Los Alamos National Laboratory; Mountain, Bruce W [NEW ZEALAND; Feng, Lu [NANKAI UNIV; Omelchenko, Marina V [NCBI/NLM/NIH; Hou, Shaobin [UNIV OF HAWAII; Saito, Jennifer A [UNIV OF HAWAII; Stott, Matthew B [NEW ZEALAND; Li, Dan [NANKAI UNIV; Zhao, Guang [NANKAI UNIV; Wu, Junli [NANKAI UNIV; Galperin, Michael Y [NCBI/NLM/NIH; Koonin, Eugene V [NCBI/NLM/NIH; Makarova, Kira S [NCBI/NLM/NIH; Wolf, Yuri I [NCBI/NLM/NIH; Rigden, Daniel J [UNIV OF LIVERPOOL; Dunfield, Peter F [UNIV OF CALGARY; Wang, Lei [NANKAI UNIV; Alam, Maqsudul [UNIV OF HAWAII

2008-01-01T23:59:59.000Z

145

Problems of Silica Scaling at Cerro Prieto Geothrmal Power Station  

DOE Green Energy (OSTI)

In the Cerro Prieto Geothermal field, where the predominant fluid in the reservoir is water, they have had problems with silica and other deposits in the first exploration wells as well as in production wells. Scaling problems have also been encountered in silencers, cyclone separators, drains, water pipes, etc. Some scale problems have also been encountered in the turbine blades of the geothermal electric plant. Most of these problems have been solved by corrective procedures which, in some cases, have turned into routine. Scale deposition is a problem that certainly diminishes the useful capacity of geothermal fluids with water predominance, but it does not actually endanger the installations, since this problem is under control.

Mercado, S.; Guiza, J.

1976-01-01T23:59:59.000Z

146

Hydrogen and oxygen adsorption stoichiometries on silica supported ruthenium nanoparticles  

DOE Green Energy (OSTI)

Treatment under H{sub 2} at 300 C of Ru(COD)(COT) dispersed on silica yields 2 nm ruthenium nanoparticles, [Ru{sub p}/SiO{sub 2}], according to EXAFS, HRTEM and XPS. H{sub 2} adsorption measurements on [Ru{sub p}/SiO{sub 2}] in the absence of O{sub 2} show that Ru particles adsorb up to ca. 2 H per surface ruthenium atoms (2H/Ru{sub s}) on various samples; this technique can therefore be used to measure the dispersion of Ru particles. In contrast, O{sub 2} adsorption on [Ru{sub p}/SiO{sub 2}] leads to a partial oxidation of the bulk at 25 C, to RuO{sub 2} at 200 C and to sintering upon further reduction under H{sub 2}, showing that O{sub 2} adsorption cannot be used to measure the dispersion of Ru particles.

Berthoud, Romain; Delichere, Pierre; Gajan, David; Lukens, Wayne; Pelzer, Katrin; Basset, Jean-Marie; Candy, Jean-Pierre; Coperet, Christophe

2008-12-01T23:59:59.000Z

147

Performance predictions of silica-gel desiccant dehumidifiers  

DOE Green Energy (OSTI)

The analysis of a cross-cooled desiccant dehumidifier using silica gel in the form of sheets is described. This unit is the principal component of solar powered desiccant air conditioning system. The mathematical model has first been formulated describing the dynamics of the dehumidifier. The model leads to a system of nonlinear coupled heat and mass transfer equations for the sorption processes and linear heat transfer equations for the purging processes. The model accounts for the gas film resistance and for the moisture diffusion in the desiccant. The governing equations are solved by a finite difference scheme to obtain periodic steady state solutions. The accuracy of the theoretical predictions is ascertained by comparing them with the experimental results. The performance of the dehumidifier, for a chosen set of initial conditions and dehumidifier parameters, has also been given.

Mathiprakasam, B.; Lavan, Z.

1980-01-01T23:59:59.000Z

148

Preparation of silica or alumina pillared crystalline titanates  

Science Conference Proceedings (OSTI)

Layered crystalline titanates (CT) [Anthony and Dosch, US Patent 5 177 045 (1993)] are pillared with tetraethyl orthosilicate, 3-aminopropyltrimethoxysilane, and aluminum acetylacetonate to prepare porous and high surface area supports for sulfided NiMo catalyst. Tetra-ethyl orthosilicate or aluminum acetylacetonate intercalated CT are prepared by stepwise intercalation. First, the basal distance is increased by n-alkylammonium ions prior to intercalation with inorganic compounds. However, an aqueous solution of 3-aminopropyltrimethoxysilane could directly pillar CT without first swelling the titanate with n-alkylamine. The catalytic activities for hydrogenation of pyrene of sulfided NiMo supported silica or alumina pillared CT were higher than those of commercial catalysts (Shell324 and Amocat1C). The silicon and aluminum contents of the pillared CT, used as supports, have a considerable effect on the catalytic activities and physical properties of the supports.

Udomsak, S.; Nge, R.; Dufner, D.C.; Anthony, R.G. [Texas A and M Univ., College Station, TX (United States); Lott, S.E. [Sandia National Labs., Albuquerque, NM (United States)

1994-05-01T23:59:59.000Z

149

Determination of silica deposition rates and thresholds applied towards protection of injection reservoirs  

SciTech Connect

This program was instituted to quantify certain aspects of silica scaling deposition processes at the Miravalles Geothermal Field, Costa Rica. The program objective was to identify the highest temperature at which silica scale will develop from partially evaporated and significantly cooled geothermal liquid under operating conditions. Integral to the study objective was the quantification of certain aspects of silica deposition processes at the Miravalles Geothermal Field, Costa Rica. There, the objective was to reduce the scaling risk associated with adding a bottoming-cycle to generate more electricity from the liquids already being produced.

Geothermal Development Associates; Don Michels Associates

1999-07-01T23:59:59.000Z

150

Method for inhibiting silica precipitation and scaling in geothermal flow systems  

DOE Patents (OSTI)

A method for inhibiting silica scaling and precipitation in geothermal flow systems by on-line injection of low concentrations of cationic nitrogen-containing compounds, particularly polymeric imines, polymeric amines, and quaternary ammonium compounds.

Harrar, Jackson E. (Castro Valley, CA); Lorensen, Lyman E. (Orinda, CA); Locke, Frank E. (Lafayette, CA)

1982-01-01T23:59:59.000Z

151

Method for inhibiting silica precipitation and scaling in geothermal flow systems  

DOE Patents (OSTI)

A method for inhibiting silica scaling and precipitation in geothermal flow systems by on-line injection of low concentrations of cationic nitrogen-containing compounds, particularly polymeric imines, polymeric amines, and quaternary ammonium compounds is described.

Harrar, J.E.; Lorensen, L.E.; Locke, F.E.

1980-06-13T23:59:59.000Z

152

Suitability of Silica Gel to Process INEEL Sodium Bearing Waste - Letter Report  

SciTech Connect

The suitability of using the silica gel process for Idaho National Engineering and Environmental Laboratory (INEEL) sodium bearing waste was investigated during fiscal year 2000. The study was co-funded by the Tanks Focus Area as part of TTP No. ID-77WT-31 and the High Level Waste Program. The task also included the investigation of possible other absorbents. Scoping tests and examination of past work showed that the silica gel absorption/adsorption and drying method was the most promising; thus only silica gel was studied and not other absorbents. The documentation on the Russian silica gel process provided much of the needed information but did not provide some of the processing detail so these facts had to be inferred or gleaned from the literature.

Kirkham, Robert John; Herbst, Alan Keith

2000-09-01T23:59:59.000Z

153

Luminescence properties of mesoporous silica nanoparticles encapsulating different europium complexes: application for biolabelling  

Science Conference Proceedings (OSTI)

In this work we have synthesized and characterized new hybrid nanoplatforms for luminescent biolabeling based on the concept of Eu3+ complexes encapsulation in mesoporous silica nanoparticles (?100 nm). Eu complexes have been selected ...

S. Lechevallier, J. Jorge, R. M. Silveira, N. Ratel-Ramond, D. Neumeyer, M. J. Menu, M. Gressier, A. L. Marçal, A. L. Rocha, M. A. U. Martines, E. Magdeleine, J. Dexpert-Ghys, M. Verelst

2013-01-01T23:59:59.000Z

154

Mesoporous silica SBA-16 functionalized with alkoxysilane groups: preparation, characterization, and release profile study  

Science Conference Proceedings (OSTI)

A mesoporous material sphere based on silica, SBA-16, was chemically modified with alkoxysilane using two different solvents: methanol and toluene. The influence of the chemical modification of the matrix on the release rate of a model drug was also ...

Gracielle Ferreira Andrade; Daniel Cristian Ferreira Soares; Ramon Kenned de Sousa Almeida; Edésia Martins Barros Sousa

2012-01-01T23:59:59.000Z

155

Synthesis of SiC ceramics by the carbothermal reduction of mineralized wood with silica  

DOE Green Energy (OSTI)

This paper describes the synthesis of SiC by the carbothermal reduction of mineralized wood with silica in acidic condition. The biomorphic cellular SiC ceramics were prepared by controlling the amount of silica and the size of SiC nanoparticles. Up to 20wt% of SiO2 was mineralized into wood cellular structures and the hierarchical structures such as cells, lumen, and pits were mainly retained after the thermal treatment at 1400 C.

Shin, Yongsoon; Wang, Chong M.; Exarhos, Gregory J.

2005-01-06T23:59:59.000Z

156

Assessment of Methods to Consolidate Iodine-Loaded Silver-Functionalized Silica Aerogel  

SciTech Connect

The U.S. Department of Energy is currently investigating alternative sorbents for the removal and immobilization of radioiodine from the gas streams in a nuclear fuel reprocessing plant. One of these new sorbents, Ag0-functionalized silica aerogels, shows great promise as a potential replacement for Ag-bearing mordenites because of its high selectivity and sorption capacity for iodine. Moreover, a feasible consolidation of iodine-loaded Ag0-functionalized silica aerogels to a durable SiO2-based waste form makes this aerogel an attractive choice for sequestering radioiodine. This report provides a preliminary assessment of the methods that can be used to consolidate iodine-loaded Ag0-functionalized silica aerogels into a final waste form. In particular, it focuses on experimental investigation of densification of as prepared Ag0-functionalized silica aerogels powders, with or without organic moiety and with or without sintering additive (colloidal silica), with three commercially available techniques: 1) hot uniaxial pressing (HUP), 2) hot isostatic pressing (HIP), and 3) spark plasma sintering (SPS). The densified products were evaluated with helium gas pycnometer for apparent density, with the Archimedes method for apparent density and open porosity, and with high-resolution scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) for the extent of densification and distribution of individual elements. The preliminary investigation of HUP, HIP, and SPS showed that these sintering methods can effectively consolidate powders of Ag0-functionalized silica aerogel into products of near-theoretical density. Also, removal of organic moiety and adding 5.6 mass% of colloidal silica to Ag0-functionalized silica aerogel powders before processing provided denser products. Furthermore, the ram travel data for SPS indicated that rapid consolidation of powders can be performed at temperatures below 950°C.

Matyas, Josef; Engler, Robert K.

2013-09-01T23:59:59.000Z

157

Geothermometry At Central Nevada Seismic Zone Region (Shevenell & De  

Open Energy Info (EERE)

Region (Shevenell & De Region (Shevenell & De Rocher, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Central Nevada Seismic Zone Region (Shevenell & De Rocher, 2005) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown References Lisa Shevenell, Ted De Rocher (2005) Evaluation Of Chemical Geothermometers For Calculating Reservoir Temperatures At Nevada Geothermal Power Plants Retrieved from "http://en.openei.org/w/index.php?title=Geothermometry_At_Central_Nevada_Seismic_Zone_Region_(Shevenell_%26_De_Rocher,_2005)&oldid=401374" Category: Exploration Activities What links here

158

Geothermometry At Walker-Lane Transitional Zone Region (Shevenell & De  

Open Energy Info (EERE)

Shevenell & De Shevenell & De Rocher, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Walker-Lane Transitional Zone Region (Shevenell & De Rocher, 2005) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown References Lisa Shevenell, Ted De Rocher (2005) Evaluation Of Chemical Geothermometers For Calculating Reservoir Temperatures At Nevada Geothermal Power Plants Retrieved from "http://en.openei.org/w/index.php?title=Geothermometry_At_Walker-Lane_Transitional_Zone_Region_(Shevenell_%26_De_Rocher,_2005)&oldid=399607" Category: Exploration Activities What links here Related changes

159

Exploratory energy research program of the University of Hawaii at Manoa. Progress report  

DOE Green Energy (OSTI)

Progress is reported from the University of Hawaii on: UHM rooftop solar energy laboratory; solar pond cleansing techniques; combustion properties of biomass pyrolysis products; high-temperature solar concentrator absorber; biological abatement of hydrogen sulfide during geothermal energy production; geothermal systems on submarine rift zones of the Hawaiian chain; nitrogenous products of OTEC chlorination; interaction of hydrogen and deuterium with transition metals and their alloys at high pressures; shallow magma chambers and geothermal potential of Haleakala, Maui; effects of OTEC waste water on phytoplankton; sodium-lithium geothermometer; breaking wave forces on OTEC pipes; seismic and thermal properties on basalts. (PSB)

Not Available

1984-01-01T23:59:59.000Z

160

Hydrology and geochemistry of thermal ground water in southwestern Idaho and north-central Nevada  

DOE Green Energy (OSTI)

The study area occupies about 14,500 square miles in southwestern Idaho and north-central Nevada. Thermal ground water occurs under artesian conditions, in discontinuous or compartmented zones, in igneous or sedimentary rocks of Tertiary age. Ground-water movement is generally northward. Temperatures of the ground water range from about 30/sup 0/ to more than 80/sup 0/C. Chemical analyses of water from 12 wells and 9 springs indicate that nonthermal waters are a calcium bicarbonate type; thermal waters are a sodium bicarbonate type. Chemical geothermometers indicate probable maximum reservoir temperatures are near 100/sup 0/C. Concentration of tritium in the thermal water water is near zero.

Young, H.W.; Lewis, R.E.

1980-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
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161

Property:ThermalInfo | Open Energy Information  

Open Energy Info (EERE)

Property Property Edit with form History Facebook icon Twitter icon » Property:ThermalInfo Jump to: navigation, search Property Name ThermalInfo Property Type Text Subproperties This property has the following 93 subproperties: A Acoustic Logs Active Seismic Methods Active Sensors Aeromagnetic Survey Airborne Electromagnetic Survey Analytical Modeling C Caliper Log Cation Geothermometers Cement Bond Log Conceptual Model Controlled Source Frequency-Domain Magnetics Cross-Dipole Acoustic Log Cuttings Analysis D Data Acquisition-Manipulation Data Collection and Mapping Data Techniques Data and Modeling Techniques Density Log Direct-Current Resistivity Survey Drilling Methods E Earth Tidal Analysis Electric Micro Imager Log Electromagnetic Sounding Methods Elemental Analysis with Fluid Inclusion

162

Dispersion Morphology of Poly(methyl acrylate)/Silica Nanocomposites  

SciTech Connect

Nearly monodisperse poly(methyl acrylate) (PMA) and spherical SiO{sub 2} nanoparticles (NP, d = 14 {+-} 4 nm) were co-cast from 2-butanone, a mutually good solvent and a displacer of adsorbed PMA from silica. The effects of NP content and post-casting sample history on the dispersion morphology were found by small-angle X-ray scattering supplemented by transmission electron microscopy. Analysis of the X-ray results show that cast and thermally annealed samples exhibited a nearly random particle dispersion. That the same samples, prior to annealing, were not well-dispersed is indicative of thermodynamic miscibility during thermal annealing over the range of NP loadings studied. A simple mean-field thermodynamic model suggests that miscibility results primarily from favorable polymer segment/NP surface interactions. The model also indicates, and experiments confirm, that subsequent exposure of the composites to the likely displacer ethyl acetate results in entropic destabilization and demixing into NP-rich and NP-lean phases.

D Janes; J Moll; S Harton; C Durning

2011-12-31T23:59:59.000Z

163

Assistant template and co-template agents in modeling mesoporous silicas and post-synthesizing organofunctionalizations  

SciTech Connect

Mesoporous SBA-16 silicas were synthesized through a direct methodology using the template (F127) combined with co-templates (ethanol and n-butanol), with tetraethylorthosilicate as the silica source. These ordered mesoporous silica were characterized by elemental analyses, infrared spectroscopy, solid-state nuclear magnetic resonance for {sup 13}C (CP/MAS) and {sup 29}Si (HP/DEC) nuclei, nitrogen sorption/desorption processes, small angle X-ray analyses (SAXS) and transmission electron microscopy (TEM). SAXS and TEM results confirmed the space group Im3m and cubic 3D symmetry, typical for highly ordered SBA-16. The sorption/desorption data for SBA-16 and when functionalized gave type IV isotherms, with hysteresis loop H2. Surface areas of 836; 657 and 618 m{sup 2} g{sup -1} and average pore diameters of 7.99; 8.10 and 9.85 nm, for SBA-16A, SBA-16B and SBA-16C were obtained, respectively. When functionalized the silicas presented a reduction in surface area, pore volume and pore diameter due to the pendant chains that interfere with nitrogen sorption in these measurements. The co-template ethanol favors the ordered mesopores with highest wall thicknesses. - Graphical Abstract: The mesoporous SBA-16 can be synthesized from binary (F127/TEOS) or ternary (F127/alcohol/TEOs) systems to give well-ordered mesoporous silicas. The co-templates ethanol or butanol gave the final material with highest wall thickness, mainly with ethanol. After these syntheses the pores were successfully organofunctionalized to give a good incorporation of the silylating agents. The final silicas presented of well-arranged solid characteristics as expressing by three distinct peaks, as indexed by the corresponding planes. Highlights: Black-Right-Pointing-Pointer Syntheses of mesoporous silicas by using ternary (F127/agent/TEOS) and binary (F127/TEOS) systems. Black-Right-Pointing-Pointer Use of co-templates to synthesize mesoporous silicas with larger wall thicknesses. Black-Right-Pointing-Pointer Immobilization of pendant chains inside the porous silicas. Black-Right-Pointing-Pointer Ordered mesoposous silicas as new materials for possible applications on sorption and delivering drug systems.

Oliveira, Vaeudo V. [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil)] [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil); Airoldi, Claudio, E-mail: airoldi@iqm.unicamp.br [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil)] [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil)

2012-12-15T23:59:59.000Z

164

Silica precipitation and scaling in a dynamic loop system. [Design and testing of titanium corrosion test loop  

DOE Green Energy (OSTI)

A titanium corrosion test loop was modified to provide a dynamic facility for studying the formation of silica precipitates and scale from simulated geothermal brines as a function of composition, temperature, and flow conditions. A schematic of the modified loop system is presented. The principal components and connecting piping are all constructed of commercially pure titanium. These components include a centrifugal pump, silica saturator column, segmented heat exchanger, reheat heat exchanger, and a high pressure feed pump (stainless steel). The system is designed to circulate simulated geothermal brines saturated with silica to approximately 300/sup 0/C for study of silica scaling. Data obtained from a test run are included. (JGB)

Bohlmann, E.G.; Shor, A.J.; Berlinski, P.

1977-01-01T23:59:59.000Z

165

Thin film nanoporous silica and graphene based biofuel cells (iBFCs) for low-power implantable medical device applications.  

E-Print Network (OSTI)

??This thesis describes the fabrication and characterization of an inorganic catalyst based glucose Biofuel cell using nanoporous (mesoporous) silica thin-film as a functional membrane. The… (more)

Sharma, Tushar

2011-01-01T23:59:59.000Z

166

Solubility of Gases in Glass. II. He, Ne, and H2 in Fused Silica  

Science Conference Proceedings (OSTI)

The statistical thermodynamics of the gas?in?glass system provides a basic model of both physical and chemical solubility. The physical solubility result is essentially equivalent to that for monatomic solubility. The chemical solubility result is dependent upon the specific system involved. The model was compared with experiment for a variety of systems. Helium and neon in fused silica were examples of the physical solubility of monatomic gases. Variations of the thermal history of the fused silica did not appear to have a measurable effect on physical solubility as evidenced in the helium data. Hydrogen in fused silica was an example of the physical solubility of polyatomic gases. Physical solubility was measured by a modified Seiverts technique and was characterized by a linear dependence on pressure. Binding energies for the physically dissolved species were of the order expected for van der Waals bonding. Vibrational frequencies were on the order of 1013 sec?1 with the heavier species having the lower frequencies. Hydrogen in fused silica was also an example of the chemical solubility of polyatomic gases. The literature gave data for the chemical solution of hydrogen in fused silica

James F. Shackelford; Perry L. Studt; Richard M. Fulrath

1972-01-01T23:59:59.000Z

167

Synthesis of palladium-doped silica nanofibers by sol-gel reaction and electrospinning process  

Science Conference Proceedings (OSTI)

Nanofiber is drawing great attention nowadays with their high surface area per volume and flexibility in surface functionalities that make them favorable as a proton exchange membrane in fuel cell application. In this study, incorporation of palladium nanoparticles in silica nanofibers was prepared by combination of a tetraorthosilane (TEOS) sol-gel reaction with electrospinning process. This method can prevent the nanoparticles from aggregation by direct mixing of palladium nanoparticles in silica sol. The as-produced electrospun fibers were thermally treated to remove poly(vinyl pyrrolidone) (PVP) and condensation of silanol in silica framework. PVP is chosen as fiber shaping agent because of its insulting and capping properties for various metal nanoparticles. Scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the silica fibers and Pd nanoparticles on the fibers. Spun fibers with average diameter ranged from 100nm to 400nm were obtained at optimum operating condition and distribution of Pd nanoparticles on silica fibers was investigated.

San, Thiam Hui; Daud, Wan Ramli Wan; Kadhum, Abdul Amir Hassan; Mohamad, Abu Bakar; Kamarudin, Siti Kartom; Shyuan, Loh Kee; Majlan, Edy Herianto [Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia and Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2012-06-29T23:59:59.000Z

168

Direct encapsulation of water-soluble drug into silica microcapsules for sustained release applications  

SciTech Connect

Direct encapsulation of water-soluble drug into silica microcapsules was facilely achieved by a sol-gel process of tetraethoxysilane (TEOS) in W/O emulsion with hydrochloric acid (HCl) aqueous solution containing Tween 80 and drug as well as cyclohexane solution containing Span 80. Two water-soluble drugs of gentamicin sulphate (GS) and salbutamol sulphate (SS) were chosen as model drugs. The characterization of drug encapsulated silica microcapsules by scanning electronic microscopy (SEM), FTIR, thermogravimetry (TG) and N{sub 2} adsorption-desorption analyses indicated that drug was successfully entrapped into silica microcapsules. The as-prepared silica microcapsules were uniform spherical particles with hollow structure, good dispersion and a size of 5-10 {mu}m, and had a specific surface area of about 306 m{sup 2}/g. UV-vis and thermogravimetry (TG) analyses were performed to determine the amount of drug encapsulated in the microcapsules. The BJH pore size distribution (PSD) of silica microcapsules before and after removing drug was examined. In vitro release behavior of drug in simulated body fluid (SBF) revealed that such system exhibited excellent sustained release properties.

Wang Jiexin; Wang Zhihui [Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Chen Jianfeng [Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China)], E-mail: chenjf@mail.buct.edu.cn; Yun, Jimmy [Nanomaterials Technology Pte. Ltd., 28 Ayer Rajah Crescent 03-03, Singapore 139959 (Singapore)

2008-12-01T23:59:59.000Z

169

Solidification of Acidic, High Nitrate Nuclear Wastes by Grouting or Absorption on Silica Gel  

Science Conference Proceedings (OSTI)

The use of grout and silica gel were explored for the solidification of four types of acidic, high nitrate radioactive wastes. Two methods of grouting were tested: direct grouting and pre-neutralization. Two methods of absorption on silica gel were also tested: direct absorption and rotary spray drying. The waste simulant acidity varied between 1 N and 12 N. The waste simulant was neutralized by pre-blending calcium hydroxide with Portland cement and blast furnace slag powders prior to mixing with the simulant for grout solidification. Liquid sodium hydroxide was used to partially neutralize the simulant to a pH above 2 and then it was absorbed for silica gel solidification. Formulations for each of these methods are presented along with waste form characteristics and properties. Compositional variation maps for grout formulations are presented which help determine the optimum "recipe" for a particular waste stream. These maps provide a method to determine the proportions of waste, calcium hydroxide, Portland cement, and blast furnace slag that provide a waste form that meets the disposal acceptance criteria. The maps guide researchers in selecting areas to study and provide an operational envelop that produces acceptable waste forms. The grouts both solidify and stabilize the wastes, while absorption on silica gel produces a solid waste that will not pass standard leaching procedures (TCLP) if required. Silica gel wastes can be made to pass most leach tests if heated to 600ºC.

A. K. Herbst; S. V. Raman; R. J. Kirkham

2004-01-01T23:59:59.000Z

170

Characterization of Dry-Air Aged Granules of Silver-Functionalized Silica Aerogel  

Science Conference Proceedings (OSTI)

This is a letter report to complete level 3 milestone "Assess aging characteristics of silica aerogels" for DOE FCRD program. Recently, samples of Ag0-functionalized silica aerogel were aged in flowing dry air for up to 6 months and then loaded with iodine. This dry-air aging simulated the impact of long-term exposure to process gases during process idling. The 6-month aged sample exhibited an iodine sorption capacity of 32 mass%, which was 9 mass % lower than that for an un-aged Ag0-functionalized silica aerogel. In an attempt to understand this decrease in sorption capacity, we characterized physical properties of the aged samples with Brunauer-Emmett-Teller (BET) nitrogen adsorption, X-ray diffraction (XRD), and high resolution scanning electron microscopy (SEM). The results showed no impact of aging on the aerogel microstructure or the silver nanoparticles in the aerogel, including their spatial distribution and morphology.

Matyas, Josef; Fryxell, Glen E.; Robinson, Matthew J.

2012-09-01T23:59:59.000Z

171

Very large-scale structures in sintered silica aerogels as evidenced by atomic force microscopy and ultra-small angle  

E-Print Network (OSTI)

Very large-scale structures in sintered silica aerogels as evidenced by atomic force microscopy of silica aerogels has been extensively studied mainly by scattering techniques (neutrons, X-rays, light) and atomic force microscopy (AFM) experiments have been carried out on aerogels at dierent steps of densi

Demouchy, Sylvie

172

Mercury Binding Sites in Thiol-Functionalized Mesostructured Silica  

SciTech Connect

Thiol-functionalized mesostructured silica with anhydrous compositions of (SiO{sub 2}){sub 1-x}(LSiO{sub 1.5}){sub x}, where L is a mercaptopropyl group and x is the fraction of functionalized framework silicon centers, are effective trapping agents for the removal of mercuric(II) ions from water. In the present work, we investigate the mercury-binding mechanism for representative thiol-functionalized mesostructures by atomic pair distribution function (PDF) analysis of synchrotron X-ray powder diffraction data and by Raman spectroscopy. The mesostructures with wormhole framework structures and compositions corresponding to x = 0.30 and 0.50 were prepared by direct assembly methods in the presence of a structure-directing amine porogen. PDF analyses of five mercury-loaded compositions with Hg/S ratios of 0.50-1.30 provided evidence for the bridging of thiolate sulfur atoms to two metal ion centers and the formation of chain structures on the pore surfaces. We find no evidence for Hg-O bonds and can rule out oxygen coordination of the mercury at greater than the 10% level. The relative intensities of the PDF peaks corresponding to Hg-S and Hg-Hg atomic pairs indicate that the mercury centers cluster on the functionalized surfaces by virtue of thiolate bridging, regardless of the overall mercury loading. However, the Raman results indicate that the complexation of mercury centers by thiolate depends on the mercury loading. At low mercury loadings (Hg/S {le} 0.5), the dominant species is an electrically neutral complex in which mercury most likely is tetrahedrally coordinated to bridging thiolate ligands, as in Hg(SBu{sup t}){sub 2}. At higher loadings (Hg/S 1.0-1.3), mercury complex cations predominate, as evidenced by the presence of charge-balancing anions (nitrate) on the surface. This cationic form of bound mercury is assigned a linear coordination to two bridging thiolate ligands.

Billinge, Simon J.L.; McKimmey, Emily J.; Shatnawi, Mouath; Kim, HyunJeong; Petkov, Valeri; Wermeille, Didier; Pinnavaia, Thomas J. (MSU); (CMU); (Iowa State)

2010-07-13T23:59:59.000Z

173

Permeability reduction of unconsolidated media due to stress-induced silica dissolution  

SciTech Connect

Permeability measurements were made on both glass beads and Ottowa sand under uniform confining stress conditions. Extreme permeability reduction (95%) of the glass beads was observed at temperatures exceeding 150/sup 0/C and confining pressures of 13.8 MPa with distilled water as the flowing fluid. Permeability reduction in the Ottowa sand (40%) was also observed at high temperature and confining pressure. Effluent analysis revealed high concentrations of silica. Subsequent 300 hour experiments with Ottowa sand exhibited a steady decrease in permeability with time. SEM photographs of post experiment cores, indicate that the permeability reduction is mainly due to stress induced silica dissolution at grain contacts.

Udell, K.S.; Lofy, J.D.

1985-03-01T23:59:59.000Z

174

Theoretical study of the light scattering from two alternating concentric double silica-gold nanoshell  

SciTech Connect

The cross section of two alternating concentric double silica-gold nanoshell (DSGNS) is obtained as a function of wavelength. Numerical calculations show that two alternating concentric DSGNSs display two separated scattering peaks that the intensity and position of the scattering peaks depend on two gold shells thicknesses and silica layer thickness between them. By varying thicknesses of the layers of the gold shells, two alternating concentric DSGNS can be designed with the scattering peak from the visible to infrared regions of the spectrum.

Khosravi, H. [Department of Physics, Kermanshah Azad University, Kermanshah, 67189-97551 (Iran, Islamic Republic of); Daneshfar, N. [Department of Physics, Razi University, Kermanshah, 67149-67346 (Iran, Islamic Republic of); Bahari, A. [Department of Physics, Lorestan University, Lorestan, 68137-17133 (Iran, Islamic Republic of)

2010-05-15T23:59:59.000Z

175

Lithium/V6O13 cells using silica nanoparticle-based composite electrolyte  

E-Print Network (OSTI)

Lithium/V6O13 cells using silica nanoparticle-based composite electrolyte Yangxing Li, Peter S) both in liquid electrolyte consisting of oligomeric poly(ethyleneglycol)dimethylether'/lithium bis of suppressing lithium dendrite growth due to the rigidity and immobility of the electrolyte structure

Khan, Saad A.

176

Inhibition of Lithium Dendrites by Fumed Silica-Based Composite Electrolytes  

E-Print Network (OSTI)

Inhibition of Lithium Dendrites by Fumed Silica-Based Composite Electrolytes Xiang-Wu Zhang State University, Raleigh, North Carolina 27695-7905, USA Lithium dendrite formation is investigated via in situ microscopy in a liquid electrolyte containing polyethylene glycol dimethyl ether lithium bis

Khan, Saad A.

177

Silica-alumina trihydrate filled epoxy castings resistant to arced SF.sub.6  

SciTech Connect

A cured, insulating, casting composition, having a coefficient of linear thermal expansion of below about 38 .times. 10.sup.-6 in./in./.degree. C and being resistant to arced sulfur hexafluoride gas, in contact with a metal surface in a sulfur hexafluoride gas environment, is made from hydantoin epoxy resin, anhydride curing agent and a filler combination of fused silica and alumina trihydrate.

Chenoweth, Terrence E. (Monroeville, PA); Yeoman, Frederick A. (Murrysville, PA)

1978-01-01T23:59:59.000Z

178

TESLA-FEL 2004-01 Silica Aerogel Radiators for Bunch Length  

E-Print Network (OSTI)

TESLA-FEL 2004-01 Silica Aerogel Radiators for Bunch Length Measurements J. B¨ahr a , V. Djordjadze aerogel are used to measure the electron bunch length at the photo injector test facility at DESY Zeuthen by the usage of aerogel is calculated analytically and Monte Carlo simulations are performed. It is shown

179

Silica control and materials tests at the Salton Sea geothermal field  

DOE Green Energy (OSTI)

The Lawrence Livermore Laboratory maintains and operates a test facility near Niland, California, in the Imperial Valley for field studies on SSGF brine chemistry, scale and solids control, materials, and injection. Recent work in silica control and materials testing is reviewed.

Quong, R.; Harrar, J.E.; McCright, R.D.; Locke, R.D.; Lorensen, L.E.; Tardiff, G.E.

1979-06-07T23:59:59.000Z

180

Coupling of Advanced Oxidation and Adsorption Processes onto Silica-Titania Composites for Low Level  

E-Print Network (OSTI)

was mercury adsorption onto calcium sulfate (CaSO4), a byproduct of the flue gas desulfurization (FGD) wet., Powers K.W., and Pitoniak E.R. (2004) Method for Purifying Flue Gases from Combustion Sources. PatentCoupling of Advanced Oxidation and Adsorption Processes onto Silica-Titania Composites for Low

Choate, Paul M.

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Facile and sensitive epifluorescent silica nanoparticles for the rapid screening of EHEC  

Science Conference Proceedings (OSTI)

This study was to develop antibodies conjugated fluorescent dye-doped silica nanoparticles (FDS-NPs) aiming to increase signals for the rapid detection of Escherichia coli O157:H7 with glass slide method. The FDS-NPs were produced with microemulsion/solgel ...

Pravate Tuitemwong, Nut Songvorawit, Kooranee Tuitemwong

2013-01-01T23:59:59.000Z

182

Refractive index and density in F- and Cl-doped silica glasses  

Science Conference Proceedings (OSTI)

The refractive index and density of fluorine- and chlorine-doped silica glasses were measured as functions of fictive temperature. The halogen concentrations were observed to have a refractive index or density that is independent of the fictive temperature were found. This implies that these properties are not affected by any heat-treatment conditions.

Kakiuchida, Hiroshi; Shimodaira, Noriaki; Sekiya, Edson H.; Saito, Kazuya; Ikushima, Akira J. [Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya, Aichi 468-8511 (Japan); Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya, Aichi 468-8511, Japan and Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa, Yokohama, Kanagawa 221-8755 (Japan); Research Center for Advanced Photon Technology, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya, Aichi 468-8511 (Japan)

2005-04-18T23:59:59.000Z

183

Effects of Surface Modification Conditions on Hydrophobicity of Silica-based Coating Additives  

SciTech Connect

Superhydrophobic silica (SHS) powders are being evaluated as a potential additive to the polyurethane topcoats used in Chemical Agent Resistant Coating (CARC) systems, with the goal of improving water repellency and corrosion protection characteristics. The current generation of CARC topcoats is already highly loaded with solids, and thus there is a premium on minimization of the total SHS powder required to achieve the desired properties. Therefore, efficient surface modification of the silica and proper dispersion in the coating will be required. The effect of a dispersant on the surface modification of silica particles by chlorosilanes was addressed in this study. The properties of various SHS powders were characterized by thermogravimetric analysis and mass spectroscopy. Correlations between powder modification conditions and the ultimate effects of the modified particles on hydrophobicity of CARC topcoats were assessed. The use of contact and rolling angle measurements along with scanning electron microscopy are discussed as they pertain to the ability to quantify the effects of modified silicas on corrosion prevention coatings. Furthermore, a systematic approach to modifying and testing both powders and top coats of corrosion prevention systems is presented.

Armstrong, Beth L [ORNL; Pawel, Steven J [ORNL; Hunter, Scott Robert [ORNL; Haynes, James A [ORNL; Hillesheim, Daniel A [ORNL

2013-01-01T23:59:59.000Z

184

Gas chemistry and thermometry of the Cerro Prieto, Mexico, geothermal field  

SciTech Connect

Gas compositions of Cerro Prieto wells in 1977 reflected strong boiling in the reservoir around wells M-20 and M-25. This boiling zone appeared to be collapsing in 1982 when a number of wells in this area of the field were shut-in. In 1977 and 1982, gas compositions also showed boiling zones corresponding to faults H and L postulated by Halfman et al. (1982). Four gas geothermometers were applied, based on reservoir equilibria and calculated fugacities. The Fisher - Tropsch reaction predicted high temperatures and appeared to re-equilibrate slowly, whereas the H/sub 2/S reaction predicted low temperatures and appeared to re-equilibrate rapidly. Hydrogen and NH/sub 3/ reactions were intermediate. Like gas compositions, the geothermometers reflected reservoir processes, such as boiling. Surface gas compositions are related to well compositions, but contain large concentrations of N/sub 2/ originating from air dissolved in groundwater. The groundwater appears to originate in the east and flow over the production field before mixing with reservoir gases near the surface.

Nehring, N.L.; D'Amore, F.D.

1984-01-01T23:59:59.000Z

185

Dating thermal events at Cerro Prieto using fission-track annealing  

DOE Green Energy (OSTI)

The duration of heating in the Cerro Prieto reservoir was estimated by relating the fading of spontaneous fission tracks in detrital apatite to observed temperatures. The rate of fading is a function of both time and temperature. The apparent fission track age of the detrital apatites then, is a function of both their source age and their time-temperature history. Data from laboratory experiments and geologic fading studies were compiled from published sources to produce lines of iso-annealing for apatite in time-temperature space. Fission track ages were calculated for samples from two wells at Cerro Prieto, one with an apparently simple and one with an apparently complex thermal history. Temperatures were estimated by empirical vitrinite reflectance geothermometry, fluid inclusion homogenization and oxygen isotope equilibrium. These estimates were compared with logs of measured borehole temperatures. The temperature in well T-366, where complete annealing first occurs, was estimated to be between 160 and 180{sup 0}C. Complete annealing at these temperatures requires 10{sup 4} and 10{sup 3} years, respectively. Well M-94 has an apparently complex thermal history. Geothermometers in this well indicate temperatures some 50 to 100{sup 0}C higher than those measured directly in the borehole. Fission tracks are partially preserved in M-94 where paleotemperatures were as high as 200{sup 0}C and are erased where geothermometers indicate temperatures of 250{sup 0}C. This implies a thermal event less than 10{sup 1} years and greater than 10{sup 0} years in duration.

Sanford, S.J.; Elders, W.A.

1981-01-01T23:59:59.000Z

186

Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, April 1--June 30, 1998  

DOE Green Energy (OSTI)

The program objective aims to identify the highest temperature at which silica scale will develop from partially evaporated and significantly cooled geothermal liquid. The approach involves tracking deposition of silica scale by monitoring the apparent electrical conductivity of the geothermal liquid in an isolation chamber. A decrease in apparent conductivity occurs because silica deposited on electrode surfaces is less conductive than the geothermal liquid. The major technical hurdle is building a conductivity monitoring system that is sensitive enough to distinguish between no silica deposition and almost no silica deposition, while accounting for other factors which also affect conductivity, such as temperature and varying fluid composition.

NONE

1998-07-01T23:59:59.000Z

187

Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, January 1, 1988--March 31, 1998  

DOE Green Energy (OSTI)

The program objective aims to identify the highest temperature at which silica scale will develop from partially evaporated and significantly cooled geothermal liquid. The approach involves tracking deposition of silica scale by monitoring the apparent electrical conductivity of the geothermal liquid in an isolation chamber. A decrease in apparent conductivity occurs because the deposited silica is less conductive than the geothermal liquid. The major technical hurdle is building a conductivity monitoring system that is sensitive enough to distinguish between no silica deposition and almost no silica deposition, while accounting for other factors which also affect conductivity, such as temperature and varying fluid composition.

NONE

1998-05-01T23:59:59.000Z

188

Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, July 1--September 30, 1998  

DOE Green Energy (OSTI)

The program objective aims to identify the highest temperature at which silica scale will develop from partially evaporated and significantly cooled geothermal liquid. The approach involves tracking deposition of silica scale by monitoring the apparent electrical conductivity of the geothermal liquid in an isolation chamber. A decrease in apparent conductivity occurs because silica deposited on electrode surfaces is less conductive than the geothermal liquid. The major technical hurdle is building a conductivity monitoring system that is sensitive enough to distinguish between no silica deposition and almost no silica deposition, while accounting for other factors which also affect conductivity, such as temperature and varying fluid composition.

NONE

1998-11-01T23:59:59.000Z

189

Interstitial BiO molecule as a center of broadband IR luminescence in bismuth-doped silica glass  

E-Print Network (OSTI)

IR luminescence and absorption in bismuth-doped silica glass-core fibers observed recently (see [arXiv:1106.2969v1 [physics.optics]) are argued to be caused by transitions in interstitial BiO molecules

Sokolov, V O; Dianov, E M

2011-01-01T23:59:59.000Z

190

Extreme Chromatography: Faster, Hotter, SmallerChapter 5 High-efficiency Liquid Chromatography Separations Achieved by Monolithic Silica Columns  

Science Conference Proceedings (OSTI)

Extreme Chromatography: Faster, Hotter, Smaller Chapter 5 High-efficiency Liquid Chromatography Separations Achieved by Monolithic Silica Columns Methods and Analyses eChapters Methods - Analyses Books AOCS Press Downloada

191

Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices ?  

E-Print Network (OSTI)

To identify ? ± and K ± in the region of 1.0 ? 2.5 GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to ?/K separation up to a few GeV/c with an efficiency greater than 90 % was considered. 1

I. Adachi; T. Sumiyoshi; K. Hayashi; N. Iida; R. Enomoto; K. Tsukada; R. Suda; S. Matsumoto; K. Natori; M. Yokoyama; H. Yokogawa

1994-01-01T23:59:59.000Z

192

Mesoporous silica film from a solution containing a surfactant and methods of making same  

DOE Patents (OSTI)

The present invention is a mesoporous silica film having a low dielectric constant and method of making having the steps of combining a surfactant in a silica precursor solution, spin-coating a film from this solution mixture, forming a partially hydroxylated mesoporous film, and dehydroxylating the hydroxylated film to obtain the mesoporous film. It is advantageous that the small polyoxyethylene ether surfactants used in spin-coated films as described in the present invention will result in fine pores smaller on average than about 20 nm. The resulting mesoporous film has a dielectric constant less than 3, which is stable in moist air with a specific humidity. The present invention provides a method for superior control of film thickness and thickness uniformity over a coated wafer, and films with low dielectric constant.

Liu, Jun (West Richland, WA); Domansky, Karel (Cambridge, MA); Li, Xiaohong (Richland, WA); Fryxell, Glen E. (Kennewick, WA); Baskaran, Suresh (Kennewick, WA); Kohler, Nathan J. (Richland, WA); Thevuthasan, Suntharampillai (Kennewick, WA); Coyle, Christopher A. (Richland, WA); Birnbaum, Jerome C. (Richland, WA)

2001-01-01T23:59:59.000Z

193

Flow cytometric analysis of respiratory tract cells exposed to oil shale and silica particulates. [Hamsters  

SciTech Connect

Flow cytometric techniques were used to measure the cytological and biochemical damage to respiratory tract cells in animals exposed to particulates. Hamsters were exposed to raw and spent oil shale particulates and silica by intratracheal instillation. Exfoliated lung cells were obtained by sacrificing the animals and lavaging the respiratory tract posterior to the trachea with saline. Cell samples were fixed in ethanol and stained with mithramycin for fluorescence analysis of DNA content. DNA content distributions from hamsters exposed to spent oil shale and silica particulates showed atypical changes 28 to 35 days later. Cell counts and total numbers of macrophages, leukocytes, and epithelial cells in the lavage fluid also showed marked changes related to time after exposure.

Steinkamp, J.A.; Wilson, J.S.

1979-01-01T23:59:59.000Z

194

Petrography study on altered flint aggregate by alkali-silica reaction  

SciTech Connect

The aim of our study is to improve our understanding of an alkali-silica reaction (ASR) via petrography. We used a chemical concrete subsystem: flint aggregate, portlandite and KOH. The altered flint aggregate is followed by optical microscopy and scanning electron microscopy (SEM) before and after acid treatment at different intervals. After acid treatment, the observations showed an increase in aggregate porosity and revealed internal degradation of the aggregate. This degradation created amorphous zones. Before acid treatment, the analyses on polished sections by scanning electron microscopy coupled with energy dispersive spectroscopy (EDS) enabled visualization of K{sup +} and Ca{sup 2+} penetration into the aggregate. The appearance of amorphous zones and penetration of positive ions into the aggregate are correlated with the increase in the molar fraction of silanol sites. This degradation is specific to the alkali-silica reaction.

Bulteel, D. [Departement Genie Civil de l'Ecole Nationale Superieure des Techniques Industrielles et des Mines de Douai, 941 rue Charles Bourseul, B.P. 838, F-59508, DOUAI Cedex (France)]. E-mail: bulteel@ensm-douai.fr; Rafai, N. [Laboratoire d'Etude et de Recherches des Materiaux a Arles, F-13631 ARLES (France); Degrugilliers, P. [Departement Genie Civil de l'Ecole Nationale Superieure des Techniques Industrielles et des Mines de Douai, 941 rue Charles Bourseul, B.P. 838, F-59508, DOUAI Cedex (France); Garcia-Diaz, E. [Departement Genie Civil de l'Ecole Nationale Superieure des Techniques Industrielles et des Mines de Douai, 941 rue Charles Bourseul, B.P. 838, F-59508, DOUAI Cedex (France)

2004-11-15T23:59:59.000Z

195

The Role of High Calcium Fly Ashes in Controlling Alkali-Silica Reactions in Concrete  

Science Conference Proceedings (OSTI)

The alkali-silica reaction (ASR) is a deleterious chemical reaction that can result in the deterioration of concrete structures. This report builds upon the results of a research and development study, funded by a broadly-based multi-national industry consortium, that is developing an engineering database on the long-term effectiveness of Class F fly ash and other supplementary cementing materials (SCMs) in counteracting ASR in concrete.

2002-11-20T23:59:59.000Z

196

A New Concept for the Fabrication of Hydrogen Selective Silica Membranes  

DOE Green Energy (OSTI)

We are attempting to fabricate H{sub 2}-selective silica-based films by ''layer-by-layer'' deposition as a new approach for thin films. A sonication-assisted deposition method was mainly used for ''layer-by-layer'' deposition. In addition, other approaches such as a dip-coating and the use of a polymer matrix with a layered silicate were contrived as well. This report shows the progress done during the 2nd Year of this award.

Michael Tsapatsis

2006-07-31T23:59:59.000Z

197

Modified Murnaghan equation of state applied to shock compression of silica, basalt, and dolomite  

DOE Green Energy (OSTI)

An equation of state previously used by the author is developed further and applied to geologic media. The equation is of the same form as the Murnaghan equation of state, but with the elastic constant terms replaced by the cohesive energy density (internal pressure), and the exponential term given as a sum of the Gruneisen parameter and the gaseous adiabatic exponent. Data for shock compression of silica, basalt, and dolomite are analyzed according to the equation.

Rogers, L.A.

1965-12-20T23:59:59.000Z

198

Sulfate Fining Chemistry in Oxidized and Reduced Soda-Lime-Silica Glasses  

SciTech Connect

Various reducing agents were used and their additions were varied to (1) increase glass quality through eliminating defects from silica scum, (2) decrease SOx emissions through changing the kind and quantity of reducing agents, and (3) improve production efficiency through increased flexibility of glass redox control during continuous processing. The work included measuring silica sand dissolution and sulfate decomposition in melts from glass batches. Glass batches were heated at a temperature-increase rate deemed similar to that experienced in the melting furnace. The sulfate decomposition kinetics was investigated with thermogravimetric analysis-differential thermal analysis and evolved gas analysis. Sulfur concentrations in glasses quenched at different temperatures were determined using X-ray fluorescence spectroscopy. The distribution of residual sand (that which was not dissolved during the initial batch reactions) in the glass was obtained as a function of temperature with optical microscopy in thin-sections of melts. The fraction of undissolved sand was measured with X-ray diffraction. The results of the present study helped Visteon Inc. reduce the energy consumption and establish the batch containing 0.118 mass% of graphite as the best candidate for Visteon glass production. The improved glass batch has a lower potential for silica scum formation and for brown fault occurrence in the final glass product. It was established that bubbles trapped in the melt even at 1450 C have a high probability to be refined when reaching the hot zone in the glass furnace. Furthermore, silica sand does not accumulate at the glass surface and dissolves faster in the batch with graphite than in the batch with carbocite.

Matyas, Josef; Hrma, Pavel R.

2005-05-13T23:59:59.000Z

199

In-depth survey report of silica flour dust during packing, transfer, and shipping at the Central Silica Company, Glass Rock Plant, Glass Rock, Ohio  

Science Conference Proceedings (OSTI)

A visit was made to the Central Silica Company, Glass Rock, Ohio to evaluate methods used to control employee exposure to silica dust. The control methods at this company included careful handling and transfer of damp materials, exhaust ventilation, good housekeeping procedures, and the use of respiratory protection. Evaluations were made of the packing area, transfer point, inside loading trucks, and ambient air at sections of the flour building. Control systems included a good exhaust-ventilation system and four ventilation hoods. Evaluations were made of samples collected by an MSA gravimeter dust sampler, the Del High volume electrostatic precipitation, and bulk and rafter samples. Dust control methods appeared to be effective due to the existence of good engineering controls, good work practices, and an effective respiratory protection program. Additional control measures included the handling of the ore as a damp material, thus reducing the generation of dust particles. Outside dust sources were being reduced. Most of the product was shipped in bulk. Plastic wrapping was used around pallet loads to reduce bag breakage and dust dispersion. A filtered air system controlled low dust levels in the Pebble Mill control room. Enclosed screens operated under negative pressure separated fine from coarse product at the process building.

Caplan, P.E.; Reed, L.D.; Amendola, A.A.; Cooper, T.C.

1981-12-01T23:59:59.000Z

200

Multiscale Filler Structure in Simplified Industrial Nanocomposite Silica/SBR Systems Studied by SAXS and TEM  

E-Print Network (OSTI)

Simplified silica (Zeosil 1165 MP) and SBR (140k carrying silanol end-groups) nanocomposites have been formulated by mixing of a reduced number of ingredients with respect to industrial applications. The thermo-mechanical history of the samples during the mixing process was monitored and adjusted to identical final temperatures. The filler structure on large scales up to micrometers was studied by transmission electron microscopy (TEM) and very small-angle X-ray scattering (SAXS). A complete quantitative model extending from the primary silica nanoparticle (of radius \\approx 10 nm), to nanoparticles aggregates, up to micrometer-sized branches with typical lateral dimension of 150 nm is proposed. Image analysis of the TEM-pictures yields the fraction of zones of pure polymer, which extend between the branches of a large-scale filler network. This network is compatible with a fractal of average dimension 2.4 as measured by scattering. On smaller length scales, inside the branches, small silica aggregates are present. Their average radius has been deduced from a Kratky analysis, and it ranges between 35 and 40 nm for all silica fractions investigated here (\\phi_si = 8-21% vol.). A central piece of our analysis is the description of the interaggregate interaction by a simulated structure factor for polydisperse spheres representing aggregates. A polydispersity of 30% in aggregate size is assumed, and interactions between these aggregates are described with a hard core repulsive potential. The same distribution in size is used to evaluate the polydisperse form factor. Comparison with the experimental intensity leads to the determination of the average aggregate compacity (assumed identical for all aggregates in the distribution, between 31% and 38% depending on \\phi_si), and thus aggregation number (ca. 45, with a large spread). Because of the effect of aggregate compacity and of pure polymer zones, the volume fraction of aggregates is higher in the branches than \\phi_si. The repulsion between aggregates has a strong effect on the apparent isothermal compressibility: it leads to a characteristic low-q depression, which cannot be interpreted as aggregate mass decrease in our data. In addition, the reinforcement effect of these silica structures in the SBR-matrix is characterized with oscillatory shear and described with a model based on the same aggregate compacity. Finally, our results show that it is possible to analyze the complex structure of interacting aggregates in nanocomposites of industrial origin in a self-consistent and quantitative manner.

Guilhem Baeza; ANNE-CAROLINE GENIX; Christophe Degrandcourt; Laurent Petitjean; Jérémie Gummel; Marc Couty; Julian OBERDISSE

2012-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Quartz dissolution and silica deposition in hot-dry-rock geothermal systems  

DOE Green Energy (OSTI)

The kinetics of quartz dissolution control the produced fluid dissolved silica concentration in geothermal systems in which the downhole residence time is finite. The produced fluid of the Phase I, Run Segment 5 experimental Hot Dry Rock (HDR) geothermal system at Fenton Hill, NM, was undersaturated with respect to quartz in one pass through the reservoir, suggesting that the rate of granite dissolution governed the outlet dissolved silica concentration in this system. The literature data for the rate of quartz dissolution in water from 65 to 625/sup 0/C is correlated using an empirical rate law which is first order in quartz surface area and degree of undersaturation of the fluid. The Arrhenius plot (ln k vs T/sup -1/) is linear over eight orders of magnitude of the rate constant, verifying the validity of the proposed rate expression. Carefully performed quartz dissolution experiments in the present study duplicated the literature data and completed the data base in the temperature range from 150 to 250/sup 0/C. Identical experiments using crushed granite indicate that the rate of quartz dissolution in the presence of granite could be as much as 1 to 2 orders of magnitude faster than the rates observed in the pure quartz experiments. A temperature dependent HDR reservoir model incorporates the quartz dissolution rate law to simulate the dissolved silica behavior during the Fenton Hill Run Segment 5 experiment. For this low-permeability, fracture-dominated reservoir, the assumptions of one-dimensional plug flow through a vertically-inclined rectangular fracture and one-dimensional rock heat conduction perpendicular to the direction of flow are employed. These simplifications lead to an analytical solution for the temperature field in the reservoir.

Robinson, B.A.

1982-07-01T23:59:59.000Z

202

Self-Assembled Mercaptan on Mesoporous Silica (SAMMS) technology of mercury removal and stabilization  

SciTech Connect

This paper explains the technology developed to produce Self-Assembled Mercaptan on Mesoporous Silica (SAMMS) for mercury removal from aqueous wastewater and from organic wastes. The characteristics of SAMMS materials, including physical characteristics and mercury loading, and its application for mercury removal and stabilization are discussed. Binding kinetics and binding speciations are reported. Preliminary cost estimates are provided for producing SAMMS materials and for mercury removal from wastewater. The characteristics of SAMMS in mercury separation were studied at PNNL using simulated aqueous tank wastes and actual tritiated pump oil wastes from Savannah River Site; preliminary results are outlined. 47 refs., 16 figs., 16 tabs.

Feng, Xiangdong; Liu, Jun; Fryxell, G.E. [and others

1997-09-01T23:59:59.000Z

203

Atomic structure of Au-nanoparticles on silica support by X-ray PDF study  

SciTech Connect

We investigated the atomic structure of gold nanoparticles with an average size of 5 nm in diameter, supported by silica. We used high-energy X-ray diffraction and the atomic pair distribution function (PDF) to probe the local atomic structure. Measurements were performed from 25 to 950 C. The structure is approximately fcc in average but exhibits small distortions. The structural distortion increases with the temperature and could be related to the catalytic activity of gold nanoparticles. Above 425 C, rapid particle growth and coalescence were observed.

Dmowski, W. [University of Tennessee, Knoxville (UTK); Yin, Hongfeng [ORNL; Dai, Sheng [ORNL; Overbury, Steven {Steve} H [ORNL; Egami, T. [University of Tennessee, Knoxville (UTK)

2010-01-01T23:59:59.000Z

204

Atomic Structure of Au Nanoparticles on a Silica Support by an X-ray PDF Study  

SciTech Connect

We investigated the atomic structure of gold nanoparticles with an average size of {approx}5 nm in diameter, supported by silica. We used high-energy X-ray diffraction and the atomic pair distribution function (PDF) to probe the local atomic structure. Measurements were performed from 25 to 950 C. The structure is approximately fcc in average but exhibits small distortions. The structural distortion increases with the temperature and could be related to the catalytic activity of gold nanoparticles. Above 425 C, rapid particle growth and coalescence were observed.

Dmowski, Wojtek; Yin, Hongfeng; Dai, Sheng; Overbury, Steven H.; Egami, Takeshi (Tennessee-K); (ORNL)

2010-05-04T23:59:59.000Z

205

Characterization of the polymer-filler interface in (gamma)-irradiated silica-reinforced polysiloxane composites  

DOE Green Energy (OSTI)

The changes in hydrogen bonding at the interface of silica-reinforced polysiloxane composites due to aging in gamma radiation environments were examined in this study. Solvent swelling was utilized to determine the individual contributions of the matrix polymer and polymer-filler interactions to the overall crosslink density. The results show how the polymer-filler hydrogen bonding dominates the overall crosslink density of the material. Air irradiated samples displayed decreased hydrogen bonding at the polymer-filler interface, while vacuum irradiation revealed the opposite effect.

Chien, A T; Balazs, B; LeMay, J

2000-04-03T23:59:59.000Z

206

Mesoporous Silica Nanomaterials for Applications in Catalysis, Sensing, Drug Delivery and Gene Transfection  

SciTech Connect

The central theme of this dissertation is represented by the versatility of mesoporous silica nanomaterials in various applications such as catalysis and bio-applications, with main focus on biological applications of Mesoporous Silica Nanospheres (MSN). The metamorphosis that we impose to these materials from catalysis to sensing and to drug and gene delivery is detailed in this dissertation. First, we developed a synthetic method that can fine tune the amount of chemically accessible organic functional groups on the pores surface of MSN by exploiting electrostatic and size matching between the cationic alkylammonium head group of the cetyltrimethylammonium bromide (CTAB) surfactant and various anionic organoalkoxysilane precursors at the micelle-water interface in a base-catalyzed condensation reaction of silicate. Aiming nature imitation, we demonstrated the catalytic abilities of the MSNs, We utilized an ethylenediamine functional group for chelating Cu{sup 2+} as a catalytic functional group anchored inside the mesopores. Thus, a polyalkynylene-based conducting polymer (molecular wire) was synthesized within the Cu-functionalized MSNs silica catalyst. For sensing applications, we have synthesized a poly(lactic acid) coated mesoporous silica nanosphere (PLA-MSN) material that serves as a fluorescence sensor system for detection of amino-containing neurotransmitters in neutral aqueous buffer. We exploited the mesoporosity of MSNs for encapsulating pharmaceutical drugs. We examined bio-friendly capping molecules such as polyamidoamine dendrimers of generations G2 to G4, to prevent the drug leaching. Next, the drug delivery system employed MSNs loaded with Doxorubicin, an anticancer drug. The results demonstrated that these nano-Trojan horses have ability to deliver Doxorubicin to cancer cells and induce their death. Finally, to demonstrate the potential of MSN as an universal cellular transmembrane nanovehicle, we anchored positively charged dendrimers on the surface of MSN and utilize them to complex cationic DNA. The p-EGFP-CI gene-coated MSN nanocomposite was able to transfect cancer cell lines, such as human HeLa and CHO cancer cell lines. The gene carrier ability of MSNs was further proved by transfecting primary cells and cotransfecting of two different genes in cancer cell lines. In sum, MSN are versatile partners in several types of applications.

Daniela Rodica Radu

2005-12-19T23:59:59.000Z

207

Femtosecond laser pulse filamentation under anomalous dispersion in fused silica. Part 1. Numerical investigation  

SciTech Connect

We report the results of investigation of femtosecond laser pulse filamentation in fused silica by varying the wavelength in the range from 800 to 2300 nm. It is shown that in the case of the anomalous group-velocity dispersion, a sequence of 'light bullets' with a high spatial and temporal localisation of the light field is formed along the filament. The relation of the formation and propagation of light bullets with the formation of an isolated anti-Stokes wing of the supercontinuum spectrum is established. (nonlinear optical phenomena)

Smetanina, E O; Kompanets, V O; Chekalin, Sergei V; Kandidov, V P

2012-10-31T23:59:59.000Z

208

Silica Deposition in Field and Laboratory Thermal Tests of Yucca Mountain Tuff  

SciTech Connect

A field thermal test was conducted by the Yucca Mountain Site Characterization Project to observe changes in the Topopah Spring Tuff middle nonlithophysal zone geohydrologic system due to thermal loading. A laboratory-scale crushed-tuff hydrothermal column test was used to investigate the tuff as a potential construction material within a nuclear-waste repository. Results of similar column tests have been cited as indications that silica deposition would plug the rock fractures above a repository and create unfavorable drainage conditions. Data from field and laboratory tests are used here to predict the magnitude of fracture sealing. For the crushed-tuff column test, a one-meter-high column was packed with crushed tuff to a porosity of about 50%. Water filling the lowermost 10 cm of the column was boiled and the vapor condensed at the top of the column, percolating down to the boiling zone. After 100 days, intergranular pore space in the saturated portion of the column was almost filled with amorphous silica. The Drift Scale Test at Yucca Mountain is a heating test in the unsaturated zone. It consists of a four-year heating phase, now complete, followed by a four-year cooling phase. Heaters in a 60-m-long drift and in the adjacent rock have heated the drift walls to 200 C. As the rock was heated, fluids naturally present in the rock migrated away from the heat sources. A boiling zone now separates an inner dry-out zone from an outer condensation zone. A heat-pipe region exists in the outer margin of the boiling zone above the heated drift. Amorphous silica coatings up to a few micrometers thick were deposited in this region. Deposits were observed in less than 10% of the fractures in the heat pipe region. Drift-scale test results yield a silica deposition rate of about 250 {micro}m/1000 years in 10% of the fractures in the heat-pipe region. We did not calculate deposition rates from our column test, but a rate of 9.1 mm/1000 years in all fractures of the heat-pipe region is predicted by Sun and Rimstidt (2002) from the results of a similar test. We believe the rate based on field-test observations is a better prediction because the field test more closely resembles the expected environment in a repository. Rates based on column-test results may be reasonable for local zones of preferred fluid flow.

S.S. Levy; S.J. Chipera; M.G. Snow

2002-08-30T23:59:59.000Z

209

Acidity and catalytic activity of zeolite catalysts bound with silica and alumina  

E-Print Network (OSTI)

Zeolites ZSM-5 (SiO2/Al2O3=30~280) and Y(SiO2/Al2O3=5.2~80) are bound with silica gel (Ludox HS-40 and Ludox AS-40) and alumina (?- Al2O3 and boehmite) by different binding methods, namely, gel-mixing, powder-mixing and powder-wet-mixing methods. The acidities of the bound catalysts and the zeolite powder are determined by NH3-TPD and FTIR. The textures of these catalysts are analyzed on a BET machine with nitrogen as a probe molecule. The micropore surface area and micropore volume are determined by t-plot method. Micropore volume distribution is determined by Horvath-Kawazoe approach with a cylindrical pore model. Mesopore volume distribution is determined by BJH method from the nitrogen desorption isotherm. Silica from the binder may react with extra-framework alumina in zeolites to form a new protonic acid. SiO2-bound catalysts have less strong acidity, Bronsted acidity and Lewis acidity than the zeolite powder. Also, the strength of strong acid sites of the zeolites is reduced when silica is embedded. Micropore surface area and micropore volume are reduced by about 19% and 18%, respectively, indicating some micropores of ZSM-5 are blocked on binding with silica. SiO2-bound ZSM-5 catalysts have less catalytic activity for butane transformation (cracking and disproportionation) and ethylene oligomerization than ZSM-5 powder. When alumina is used as a binder, both the total acid sites and Lewis acid sites are increased. Micropore surface area and micropore volume of ZSM-5 powder are reduced by 26% and 23%, respectively, indicating some micropores of ZSM-5 are blocked by the alumina binder. Alumina-bound catalysts showed a lower activity for butane transformation and ethylene oligomerization than ZSM-5 powder. Alkaline metals content in the binder is a crucial factor that influences the acidity of a bound catalyst. The metal cations neutralize more selectively Bronsted acid sites than Lewis acid sites. Alkaline metal cations in the binder and micropore blockage cause the bound catalysts to have a lower catalytic activity than the zeolite powder.

Wu, Xianchun

2003-12-01T23:59:59.000Z

210

Comparison of artificial neural network and fuzzy logic models for prediction of long-term compressive strength of silica fume concrete  

Science Conference Proceedings (OSTI)

In this study, an artificial neural network (ANN) and fuzzy logic (FL) study were developed to predict the compressive strength of silica fume concrete. A data set of a laboratory work, in which a total of 48 concretes were produced, was utilized in ... Keywords: Compressive strength, Concrete, Fuzzy logic, Neural networks, Silica fume

Fatih Özcan; Cengiz D. Ati?; Okan Karahan; Erdal Uncuo?lu; Harun Tanyildizi

2009-09-01T23:59:59.000Z

211

SILICA GEL BEHAVIOR UNDER DIFFERENT EGS CHEMICAL AND THERMAL CONDITIONS: AN EXPERIMENTAL STUDY  

Science Conference Proceedings (OSTI)

Fractures and fracture networks are the principal pathways for migration of water and contaminants in groundwater systems, fluids in enhanced geothermal systems (EGS), oil and gas in petroleum reservoirs, carbon dioxide leakage from geological carbon sequestration, and radioactive and toxic industrial wastes from underground storage repositories. When dealing with EGS fracture networks, there are several major issues to consider, e.g., the minimization of hydraulic short circuits and losses of injected geothermal fluid to the surrounding formation, which in turn maximize heat extraction and economic production. Gel deployments to direct and control fluid flow have been extensively and successfully used in the oil industry for enhanced oil recovery. However, to the best of our knowledge, gels have not been applied to EGS to enhance heat extraction. In-situ gelling systems can either be organic or inorganic. Organic polymer gels are generally not thermostable to the typical temperatures of EGS systems. Inorganic gels, such as colloidal silica gels, however, may be ideal blocking agents for EGS systems if suitable gelation times can be achieved. In the current study, we explore colloidal silica gelation times and rheology as a function of SiO{sub 2} concentration, pH, salt concentration, and temperature, with preliminary results in the two-phase field above 100 C. Results at 25 C show that it may be possible to choose formulations that will gel in a reasonable and predictable amount of time at the temperatures of EGS systems.

Hunt, J D; Ezzedine, S M; Bourcier, W; Roberts, S

2012-01-19T23:59:59.000Z

212

Highly ordered Zn-doped mesoporous silica: An efficient catalyst for transesterification reaction  

Science Conference Proceedings (OSTI)

Designing highly ordered material with nanoscale periodicity is of great significance in the field of solid state chemistry. Herein, we report the synthesis of highly ordered 2D-hexagonal mesoporous zinc-doped silica using a mixture of anionic and cationic surfactants under hydrothermal conditions. Powder XRD, N{sub 2} sorption, TEM analysis revealed highly ordered 2D-hexagonal arrangements of the pores with very good surface area (762 m{sup 2} g{sup -1}) in this Zn-rich mesoporous material. Chemical analysis shows very high loading of zinc (ca. 12.0 wt%) in the material together with retention of hexagonal pore structure. Interestingly, high temperature calcination resulted into zinc silicate phase, unlike any ZnO phase, which otherwise is expected under heat treatments. High surface area together with Zn loading in this mesoporous material has been found useful for the catalytic activity of the materials in the acid-catalyzed transesterification reactions of various esters under mild liquid phase conditions. - Graphical abstract: Zn-rich 2D-hexagonal mesoporous materials are synthesized hydrothermally, which show very good catalytic activity in the transesterification reaction under mild liquid phase reaction conditions. Highlights: > Zn-rich 2D-hexagonal mesoporous silica. > High surface area material. > Efficient catalyst in liquid phase transesterification reaction. > Biodiesel production.

Pal, Nabanita; Paul, Manidipa [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Bhaumik, Asim, E-mail: msab@iacs.res.in [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

2011-07-15T23:59:59.000Z

213

Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices  

E-Print Network (OSTI)

To identify $\\pi^{\\pm}$ and $K^{\\pm}$ in the region of $1.0\\sim 2.5$ GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to $\\pi / K$ separation up to a few GeV/c %in the momentum range of $1.0 \\sim 2.5$ GeV/c with an efficiency greater than $90$ \\% was considered.

I. Adachi et al

1994-12-13T23:59:59.000Z

214

Power scaling analysis of fiber lasers and amplifiers based on non-silica materials  

SciTech Connect

A developed formalism for analyzing the power scaling of diffraction limited fiber lasers and amplifiers is applied to a wider range of materials. Limits considered include thermal rupture, thermal lensing, melting of the core, stimulated Raman scattering, stimulated Brillouin scattering, optical damage, bend induced limits on core diameter and limits to coupling of pump diode light into the fiber. For conventional fiber lasers based upon silica, the single aperture, diffraction limited power limit was found to be 36.6kW. This is a hard upper limit that results from an interaction of the stimulated Raman scattering with thermal lensing. This result is dependent only upon physical constants of the material and is independent of the core diameter or fiber length. Other materials will have different results both in terms of ultimate power out and which of the many limits is the determining factor in the results. Materials considered include silica doped with Tm and Er, YAG and YAG based ceramics and Yb doped phosphate glass. Pros and cons of the various materials and their current state of development will be assessed. In particular the impact of excess background loss on laser efficiency is discussed.

Dawson, J W; Messerly, M J; Heebner, J E; Pax, P H; Sridharan, A K; Bullington, A L; Beach, R J; Siders, C W; Barty, C P; Dubinskii, M

2010-03-30T23:59:59.000Z

215

High resolution transmission electron microscopy of melamine-formaldehyde aerogels and silica aerogels  

Science Conference Proceedings (OSTI)

The goal of the high resolution transmission electron microscopy (HRTEM) was to image the structure of two tetramethyl orthosilicate (TMOS) and two melamine-formaldehyde (MF) aerogels at the single polymer chain level{sup 1,2}. With this level of structural resolution we hoped to interrelate each aerogel's structure with its physical properties and its method of synthesis. Conventional single-step base catalysed TMOS aerogels show strings of spheroidal particles linked together with minimal necking. The spheroidal particles range from 86--132 {Angstrom} and average 113{plus minus}10 {Angstrom} in diameter{sup 2}. In contrast the TMOS aerogels reported on here were made by a two step method. After extended silica chains are grown in solution under acidic conditions with a substoichiometric amount of water, the reaction is stopped and the methanol hydrolysed from TMOS is removed. Then base catalysis and additional water are added to cause gel formation is a nonalcoholic solvent. The MF aerogels were prepared for HRTEM by fracturing them on a stereo microscope stage with razor knife so that fractured pieces with smooth flat surfaces could be selected for platinum-carbon replication. The two silica (TMOS) aerogels were both transparent and difficult to see. These aerogels were fractured on a stereo microscope stage with tweezers. 6 refs., 4 figs.

Ruben, G.C. (Dartmouth Coll., Hanover, NH (United States). Dept. of Biological Sciences)

1991-09-01T23:59:59.000Z

216

Highly ordered magnetic mesoporous silicas for effective elimination of carbon monoxide  

Science Conference Proceedings (OSTI)

Catalysts based on crystalline nanoparticles of Fe metal supported on mesoporous silica have been developed. The synthetic process involves hydrogen reduction processing for high abundant Fe metal nanoparticles within the mesopores, in which impregnated Fe salt in the inner nanopores of mesoporous silica is thermally treated under hydrogen at 500 Degree-Sign C. Detailed characterization was achieved by XRD, XPS, BET, and HR-TEM techniques. The catalytic efficiency was demonstrated as a function of the used amounts and reaction time. The results show that more than 90% of the carbon monoxide was eliminated at room temperature during a period 80 min with 0.5 g of catalyst. - Graphical abstract: Strategy for the preparation of highly abundant Fe nanoparticle embedded MS catalyst by hydrogen reduction process and HR-TEM images of cross-sectional and top view. Highlights: Black-Right-Pointing-Pointer MS based heterogeneous catalyst with Fe nanoparticles were demonstrated for CO elimination. Black-Right-Pointing-Pointer Highly Fe nanoparticle embedded MS catalyst prepared by hydrogen reduction process. Black-Right-Pointing-Pointer Systematic characterization was achieved by XRD, XPS, BET, and HR-TEM analyses. Black-Right-Pointing-Pointer More than 90% of the CO was eliminated at RT during 80 min with 0.5 g of catalyst.

Lee, Jiho [Korea Institute of Ceramic Engineering and Technology, Seoul 153-801 (Korea, Republic of); Department of Chemistry, Inha University, Incheon 402-751 (Korea, Republic of); Ho Chang, Jeong, E-mail: jhchang@kicet.re.kr [Korea Institute of Ceramic Engineering and Technology, Seoul 153-801 (Korea, Republic of)

2012-04-15T23:59:59.000Z

217

SYNTHESIS OF OXYGENATED PRODUCTS FROM CARBON MONOXIDE AND HYDROGEN OVER SILICA- AND ALUMINA-SUPPORTED RUTHENIUM CATALYSTS  

E-Print Network (OSTI)

Formation Over a 1.01; Ru/A1 o Catalyst at 498K H/CO P (atm)a silica-supported Ru catalyst Fig. 2 Effect of feed flowan alumina-supported Ru catalyst Fig. 3 Effect of reaction

Kellner, C.Stephen

2013-01-01T23:59:59.000Z

218

Molecular Dynamics Studies on the Effects of Water Speciation on Interfacial Structure and Dynamics in Silica-Filled PDMS Composites  

DOE Green Energy (OSTI)

Significant changes in materials properties of siloxane based polymers can be obtained by the addition of inorganic fillers. In silica-filled polydimethylsiloxane (PDMS) based composites the mechanism of this reinforcing behavior is presumably hydrogen bonding between surface hydroxyls and backbone siloxane species. We have chosen to investigate in detail the effect of chemisorbed and physisorbed water on the interfacial structure and dynamics in silica-filled PDMS based composites. Toward this end, we have combined molecular dynamics simulations and experimental studies employing DMA and Nh4R analysis. Our results suggest that the polymer-silica contact distance and the mobility of interfacial polymer chains significantly decreased as the hydration level at the interface was reduced. The reduced mobility of the PDMS chains in the interfacial domain reduced the overall, bulk, motional properties of the polymer, thus causing an effective ''stiffening'' of the polymer matrix. The role of the long-ranged Coulombic interactions on the structural features and chain dynamics of the polymer were also examined. Both are found to be strongly influenced by the electrostatic interactions as identified by the bond orientation time correlation function and local density distribution functions. These results have important implications for the design of nanocomposite silica-siloxane materials.

Gee, R H; Maxwell, R S; Dinh, L N; Balazs, B

2001-11-21T23:59:59.000Z

219

Reducing Logistics Footprints and Replenishment Demands: Nano-engineered Silica Aerogels a Proven Method for Water Treatment  

SciTech Connect

Rapid deployment and the use of objective force aggressively reduce logistic footprints and replenishment demands. Maneuver Sustainment requires that Future Combat Systems be equipped with water systems that are lightweight, have small footprints, and are highly adaptable to a variety of environments. Technologies employed in these settings must be able to meet these demands. Lawrence Livermore National Laboratory has designed and previously field tested nano-engineered materials for the treatment of water. These materials have been either based on silica aerogel materials or consist of composites of these aerogels with granular activated carbon (GAC). Recent tests have proven successful for the removal of contaminants including uranium, hexavalent chromium, and arsenic. Silica aerogels were evaluated for their ability to purify water that had been spiked with the nerve agent VX (O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate). These results demonstrated that silica aerogels were able to remove the VX from the supply water and were nearly 30 times more adsorbent than GAC. This performance could result in REDUCING CHANGEOUT FREQUENCY BY A FACTOR OF 30 or DECREASING the VOLUME of adsorbent BY A FACTOR OF 30; thereby significantly reducing logistic footprints and replenishment demands. The use of the nano-engineered Silica Aerogel/GAC composites would provide a water purification technology that meets the needs of Future Combat Systems.

Daily, W; Coleman, S; Love, A; Reynolds, J; O'Brien, K; Gammon, S

2004-09-22T23:59:59.000Z

220

Durability of LDPE nanocomposites with clay, silica, and zinc oxide: part I: mechanical properties of the nanocomposite materials  

Science Conference Proceedings (OSTI)

Three types of LDPE-based nanocomposites with montmorillonite clay, silica, and zinc oxide were prepared by melt blending the nanofiller with the resin. As a prelude to studying their durability, the extent of reinforcement of the LDPE matrix by the ...

Halim Hamid Redhwi, Mohammad Nahid Siddiqui, Anthony L. Andrady, Syed Hussain

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
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221

Silver nanoparticles confined in SBA-15 mesoporous silica and the application as a sensor for detecting hydrogen peroxide  

Science Conference Proceedings (OSTI)

Silver nanoparticles within the pore channels of selectively grafted mesoporous silica SBA-15 were synthesized. Silanols on the external surface of as-SBA-15 were first capped by -Si(CH3)3 groups. After removal of the template of ...

Dong-Hai Lin; Yan-Xia Jiang; Ying Wang; Shi-Gang Sun

2008-01-01T23:59:59.000Z

222

A New Concept for the Fabrication of Hydrogen Selective Silica Membranes  

NLE Websites -- All DOE Office Websites (Extended Search)

New CoNCept for the fAbriCAtioN of New CoNCept for the fAbriCAtioN of hydrogeN SeleCtive SiliCA MeMbrANeS Background As stated in the National Research Council report on Novel Approaches to Carbon Management, a novel membrane is needed that can achieve the separation of carbon dioxide (CO 2 ) and hydrogen (H 2 ) at a high temperature and pressure. Extensive efforts over the last several decades have explored high temperature H 2 -selective membranes made of silicon dioxide (SiO 2 ) and other oxides, palladium (Pd) and other metals or alloys and, more recently, various zeolites and non-aluminosilicate molecular sieves. Although promising separation results have been reported for many of them, these technologies, they all suffer from high production costs for membrane fabrication and from long term stability problems. This project revisits

223

Post-Harvest Processing Methods for Reduction of Silica and Alkali Metals in Wheat Straw  

SciTech Connect

Silica and alkali metals in wheat straw limit its use for bioenergy and gasification. Slag deposits occur via the eutectic melting of SiO2 with K2O, trapping chlorides at surfaces and causing corrosion. A minimum melting point of 950°C is desirable, corresponding to SiO2:K2O of about 3:1. Mild chemical treatments were used to reduce Si, K, and Cl, while varying temperature, concentration, %-solids, and time. Dilute acid was more effective at removing K and Cl, while dilute alkali was more effective for Si. Reduction of minerals in this manner may prove economical for increasing utilization of the straw for combustion or gasification.

Thompson, David Neal; Lacey, Jeffrey Alan; Shaw, Peter Gordon

2002-04-01T23:59:59.000Z

224

Development of transparent silica aerogel over a wide range of densities  

E-Print Network (OSTI)

We have succeeded in developing hydrophobic silica aerogels over a wide range of densities (i.e. refractive indices). A pinhole drying method was invented to make possible producing highly transparent aerogels with entirely new region of refractive indices of 1.06-1.26. Obtained aerogels are more transparent than conventional ones, and the refractive index is well controlled in the pinhole drying process. A test beam experiment was carried out in order to evaluate the performance of the pinhole-dried aerogels as a Cherenkov radiator. A clear Cherenkov ring was successfully observed by a ring imaging Cherenkov counter. We also developed monolithic and hydrophobic aerogels with a density of 0.01 g/cm^3 (a low refractive index of 1.0026) as a cosmic dust capturer for the first time. Consequently, aerogels with any refractive indices between 1.0026 and 1.26 can be produced freely.

Makoto Tabata; Ichiro Adachi; Yoshikazu Ishii; Hideyuki Kawai; Takayuki Sumiyoshi; Hiroshi Yokogawa

2011-12-21T23:59:59.000Z

225

Tanpopo cosmic dust collector: Silica aerogel production and bacterial DNA contamination analysis  

E-Print Network (OSTI)

Hydrophobic silica aerogels with ultra-low densities have been designed and developed as cosmic dust capture media for the Tanpopo mission which is proposed to be carried out on the International Space Station. Glass particles as a simulated cosmic dust with 30 \\mu m in diameter and 2.4 g/cm^3 in density were successfully captured by the novel aerogel at a velocity of 6 km/s. Background levels of contaminated DNA in the ultra-low density aerogel were lower than the detection limit of a polymerase chain reaction assay. These results show that the manufactured aerogel has good performance as a cosmic dust collector and sufficient quality in respect of DNA contamination. The aerogel is feasible for the biological analyses of captured cosmic dust particles in the astrobiological studies.

Tabata, Makoto; Yokobori, Shin-ichi; Kawai, Hideyuki; Takahashi, Jun-ichi; Yano, Hajime; Yamagishi, Akihiko

2011-01-01T23:59:59.000Z

226

Development of transparent silica aerogel over a wide range of densities  

E-Print Network (OSTI)

We have succeeded in developing hydrophobic silica aerogels over a wide range of densities (i.e. refractive indices). A pinhole drying method was invented to make possible producing highly transparent aerogels with entirely new region of refractive indices of 1.06-1.26. Obtained aerogels are more transparent than conventional ones, and the refractive index is well controlled in the pinhole drying process. A test beam experiment was carried out in order to evaluate the performance of the pinhole-dried aerogels as a Cherenkov radiator. A clear Cherenkov ring was successfully observed by a ring imaging Cherenkov counter. We also developed monolithic and hydrophobic aerogels with a density of 0.01 g/cm^3 (a low refractive index of 1.0026) as a cosmic dust capturer for the first time. Consequently, aerogels with any refractive indices between 1.0026 and 1.26 can be produced freely.

Tabata, Makoto; Ishii, Yoshikazu; Kawai, Hideyuki; Sumiyoshi, Takayuki; Yokogawa, Hiroshi; 10.1016/j.nima.2010.02.241

2011-01-01T23:59:59.000Z

227

X-ray radiographic technique for measuring density uniformity of silica aerogel  

E-Print Network (OSTI)

This paper proposes a new X-ray radiographic technique for measuring density uniformity of silica aerogels used as radiator in proximity-focusing ring-imaging Cherenkov detectors. To obtain high performance in a large-area detector, a key characteristic of radiator is the density (i.e. refractive index) uniformity of an individual aerogel monolith. At a refractive index of n = 1.05, our requirement for the refractive index uniformity in the transverse plane direction of an aerogel tile is |\\delta (n - 1)/(n - 1)| aerogels from a trial production and that of Panasonic products (SP-50) as a reference, and to confirm they have sufficient density uniformity within \\pm 1% along the transverse plane direction. The measurement results show that the proposed technique can quantitatively estimate the density uniformity of aerogels.

Makoto Tabata; Yoshikiyo Hatakeyama; Ichiro Adachi; Takeshi Morita; Keiko Nishikawa

2012-12-14T23:59:59.000Z

228

Performance predictions of silica-gel desiccant dehumidifiers. Technical report No. 3  

SciTech Connect

The analysis of a cross-cooled desiccant dehumidifier using silica gel in the form of sheets is described. This unit is the principal component of solar powered desiccant air conditioning system. The mathematical model has first been formulated describing the dynamics of the dehumidifier. The model leads to a system of nonlinear coupled heat and mass transfer equations for the sorption processes and linear heat transfer equations for the purging processes. The model accounts for the gas film resistance and for the moisture diffusion in the desiccant. The governing equations are solved by a finite difference scheme to obtain periodic steady state solutions. The accuracy of the theoretical predictions is ascertained by comparing them with the experimental results. The performance of the dehumidifier, for a chosen set of initial conditions and dehumidifier parameters, has also been given.

Mathiprakasam, B.; Lavan, Z.

1980-01-01T23:59:59.000Z

229

Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) |  

Open Energy Info (EERE)

Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) Exploration Activity Details Location Yellowstone Caldera Geothermal Region Exploration Technique Isotopic Analysis-Fluid Activity Date 1977 Usefulness not indicated DOE-funding Unknown Exploration Basis Estimate deep reservoir temperature Notes The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested. Methods are described to calculate the effects of boiling and dilution. The geothermometer, is applied to thermal systems of Yellowstone Park, Wyoming, Long Valley, California, and Raft River, Idaho to estimate deep reservoir temperatures

230

Compound and Elemental Analysis At Walker-Lane Transitional Zone Region  

Open Energy Info (EERE)

Laney, 2005) Laney, 2005) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Compound and Elemental Analysis Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

231

Isotopic Analysis-Fluid At Long Valley Caldera Geothermal Area (1977) |  

Open Energy Info (EERE)

Fluid At Long Valley Caldera Geothermal Area (1977) Fluid At Long Valley Caldera Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Long Valley Caldera Geothermal Area (1977) Exploration Activity Details Location Long Valley Caldera Geothermal Area Exploration Technique Isotopic Analysis-Fluid Activity Date 1977 Usefulness not indicated DOE-funding Unknown Exploration Basis Estimate deep reservoir temperature Notes The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested. Methods are described to calculate the effects of boiling and dilution. The geothermometer, is applied to thermal systems of Yellowstone Park, Wyoming, Long Valley, California, and Raft River, Idaho to estimate deep reservoir temperatures

232

Geothermometry At Coso Geothermal Area (1980) | Open Energy Information  

Open Energy Info (EERE)

Geothermometry At Coso Geothermal Area (1980) Geothermometry At Coso Geothermal Area (1980) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Geothermometry Activity Date 1980 Usefulness useful DOE-funding Unknown Exploration Basis Fluid temperature of feed water Notes Cation and sulfate isotope geothermometers indicate that the reservoir feeding water to the Coso Hot Spring well has a temperature of about 240 -250 C, and the reservoir feeding the CGEH well has a temperature of about 205 C. The variation in the chemical composition of water from the two wells suggests a model in which water-rock chemical equilibrium is maintained as a convecting solution cools from about 245-205 C by conductive heat loss. References Fournier, R.O.; Thompson, J.M.; Austin, C.F. (10 May 1980)

233

Geothermometry At Central Nevada Seismic Zone Region (Laney, 2005) | Open  

Open Energy Info (EERE)

Region Region (Laney, 2005) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

234

Property:StratInfo | Open Energy Information  

Open Energy Info (EERE)

StratInfo StratInfo Jump to: navigation, search Property Name StratInfo Property Type Text Subproperties This property has the following 82 subproperties: 2 2-M Probe Survey A Active Seismic Methods Airborne Electromagnetic Survey Analytical Modeling C Caliper Log Cation Geothermometers Cement Bond Log Chemical Logging Compound and Elemental Analysis Conceptual Model Controlled Source Frequency-Domain Magnetics Cuttings Analysis D Data Acquisition-Manipulation Data Techniques Data and Modeling Techniques Drilling Methods E Earth Tidal Analysis Electric Micro Imager Log Electromagnetic Sounding Methods Elemental Analysis with Fluid Inclusion F FLIR Flow Test Fluid Inclusion Analysis Fluid Lab Analysis Formation Testing Techniques Frequency-Domain Electromagnetic Survey G Gas Geothermometry

235

Geochemistry of the Wendel-Amedee Geothermal System-California | Open  

Open Energy Info (EERE)

Geochemistry of the Wendel-Amedee Geothermal System-California Geochemistry of the Wendel-Amedee Geothermal System-California Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Geochemistry of the Wendel-Amedee Geothermal System-California Abstract The fluid chemistry of the geothermal system that feed Amedee and Wendel Hot Springs in eastern California is complex. Two thermal fluids have been identified based on the concentrations of the conservative elements C1 and B, fluid enthalpies, and the application of chemical geothermometers. One is characterized by temperatures above 120°C and a TDS content of 1300 ppm, and will be used by GeoProducts Corporation to produce electricity. The second did lower in temperature, 75°C, and has a TDS content of 650 ppm. This fluid may be used fore direct heat application at the Susanville

236

Water Sampling At Rhodes Marsh Area (Coolbaugh, Et Al., 2006) | Open Energy  

Open Energy Info (EERE)

Rhodes Marsh Area (Coolbaugh, Et Al., 2006) Rhodes Marsh Area (Coolbaugh, Et Al., 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Water Sampling At Rhodes Marsh Area (Coolbaugh, Et Al., 2006) Exploration Activity Details Location Rhodes Marsh Area Exploration Technique Water Sampling Activity Date Usefulness useful DOE-funding Unknown Notes Follow up (to ASTER satellite imaging) analysis of spring and well waters yielded geothermometer reservoir estimates up to 162°C References Mark F. Coolbaugh, Chris Kraft, Chris Sladek, Richard E. Zehner, Lisa Shevenell (2006) Quaternary Borate Deposits As A Geothermal Exploration Tool In The Great Basin Retrieved from "http://en.openei.org/w/index.php?title=Water_Sampling_At_Rhodes_Marsh_Area_(Coolbaugh,_Et_Al.,_2006)&oldid=387552"

237

Lithium In Tufas Of The Great Basin- Exploration Implications For  

Open Energy Info (EERE)

In Tufas Of The Great Basin- Exploration Implications For In Tufas Of The Great Basin- Exploration Implications For Geothermal Energy And Lithium Resources Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Lithium In Tufas Of The Great Basin- Exploration Implications For Geothermal Energy And Lithium Resources Details Activities (8) Areas (4) Regions (0) Abstract: Lithium/magnesium, lithium/sodium, and to a lesser extent, potassium/magnesium ratios in calcium carbonate tufa columns provide a fingerprint for distinguishing tufa columns formed from thermal spring waters versus those formed from non-thermal spring waters. These ratios form the basis of the Mg/Li, Na/Li, and K/Mg fluid geothermometers commonly used in geothermal exploration, which are based on the fact that at elevated temperatures, due to mineral-fluid equilibria, lithium

238

Calculation of geothermal reservoir temperatures and steam fractions from gas compositions  

DOE Green Energy (OSTI)

This paper deals with the chemical equilibria and physical characteristics of the fluid in the reservoir (temperature, steam fraction with respect to total water, gas/steam ratio, redox conditions), which seem to be responsible for the observed concentrations of some reactive species found in the geothermal fluids (CO2, H2, H2S and CH4). Gas geochemistry is of particular interest in vapor-dominated fields where the fluid discharged consists of almost pure steam containing a limited number of volatile chemical species. Considering several geothermal systems, a good correlation has been obtained among the temperatures calculated from the gas geothermometers and the temperatures measured in the reservoir of evaluated by other physical or chemical methods. 24 refs., 5 figs.

D'Amore, F.; Truesdell, A.H.

1985-01-01T23:59:59.000Z

239

An evaluation of the geothermal potential of the Tecuamburro Volcano area of Guatemala  

DOE Green Energy (OSTI)

Radiometric ages indicate that the Tecuamburro Volcano and three adjacent lava domes grew during the last 38,300 years, and that a 360-m-wide phreatic crater, Laguna Ixpaco, was formed near the base of these domes about 2900 years ago. Laguna Ixpaco is located within the Chupadero crater, from which pyroxene pumice deposits were erupted 38,300 years ago. Thus, the likelihood is great for a partly molten or solid-but-still-hot near-surface intrusion beneath the area. Fumaroles and hot springs issue locally from the Tecuamburro volcanic complex and near Laguna Ixpaco. Analyses of gas and fluid samples from these and other nearby thermal manifestations yield chemical-geothermometer temperatures of about 150{degree} to 300{degree}C, with the highest temperatures at Ixpaco. The existence of a commercial-grade geothermal reservoir beneath the Ixpaco area seems likely. 84 refs., 70 figs., 12 tabs.

Heiken, G.; Duffield, W. (eds.)

1990-09-01T23:59:59.000Z

240

Isotopic Analysis-Fluid At Raft River Geothermal Area (1977) | Open Energy  

Open Energy Info (EERE)

Isotopic Analysis-Fluid At Raft River Geothermal Area (1977) Isotopic Analysis-Fluid At Raft River Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Raft River Geothermal Area (1977) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date 1977 Usefulness not indicated DOE-funding Unknown Exploration Basis Estimate deep reservoir temperature Notes The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested. Methods are described to calculate the effects of boiling and dilution. The geothermometer, is applied to thermal systems of Yellowstone Park, Wyoming, Long Valley, California, and Raft River, Idaho to estimate deep reservoir temperatures

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Geothermal reservoir temperatures estimated from the oxygen isotope  

Open Energy Info (EERE)

reservoir temperatures estimated from the oxygen isotope reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Geothermal reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes Details Activities (3) Areas (3) Regions (0) Abstract: The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested as a geothermometer in three areas of the western United States. Limited analyses of spring and borehole fluids and existing experimental rate studies suggest that dissolved sulfate and water are probably in isotopic equilibrium in all reservoirs of significant size with temperatures above

242

Compound and Elemental Analysis At Central Nevada Seismic Zone Region  

Open Energy Info (EERE)

Compound and Elemental Analysis At Central Nevada Compound and Elemental Analysis At Central Nevada Seismic Zone Region (Laney, 2005) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Compound and Elemental Analysis Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in

243

Water Sampling At Northern Basin & Range Region (Laney, 2005) | Open Energy  

Open Energy Info (EERE)

Water Sampling At Northern Basin & Range Region Water Sampling At Northern Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Water Sampling Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

244

Compound and Elemental Analysis At Lassen Volcanic National Park Area  

Open Energy Info (EERE)

Janik & Mclaren, 2010) Janik & Mclaren, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Compound and Elemental Analysis At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Exploration Activity Details Location Lassen Volcanic National Park Area Exploration Technique Compound and Elemental Analysis Activity Date Usefulness not indicated DOE-funding Unknown Notes Analyses of eight well samples taken consecutively during the flow test showed an inverse correlation between NH3 and Cl_ concentrations. The last sample taken had a pH of 8.35 and contained 2100 ppm Cl_ and 0.55 ppm NH3. Ratios of Na+/K+ and Na+/Cl_ remained nearly constant throughout the flow test. Cation geothermometers (with inherent uncertainties of at least

245

Geothermometry At Northern Basin & Range Region (Laney, 2005) | Open Energy  

Open Energy Info (EERE)

Geothermometry At Northern Basin & Range Region (Laney, 2005) Geothermometry At Northern Basin & Range Region (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Northern Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of

246

Geothermometry At Lassen Volcanic National Park Area (Janik & Mclaren,  

Open Energy Info (EERE)

Geothermometry At Lassen Volcanic National Park Area (Janik & Mclaren, Geothermometry At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Exploration Activity Details Location Lassen Volcanic National Park Area Exploration Technique Geothermometry Activity Date Usefulness useful DOE-funding Unknown Notes Analyses of eight well samples taken consecutively during the flow test showed an inverse correlation between NH3 and Cl_ concentrations. The last sample taken had a pH of 8.35 and contained 2100 ppm Cl_ and 0.55 ppm NH3. Ratios of Na+/K+ and Na+/Cl_ remained nearly constant throughout the flow test. Cation geothermometers (with inherent uncertainties of at least

247

Exploration Of The Upper Hot Creek Ranch Geothermal Resource, Nye County,  

Open Energy Info (EERE)

Of The Upper Hot Creek Ranch Geothermal Resource, Nye County, Of The Upper Hot Creek Ranch Geothermal Resource, Nye County, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Exploration Of The Upper Hot Creek Ranch Geothermal Resource, Nye County, Nevada Details Activities (2) Areas (1) Regions (0) Abstract: The Upper Hot Creek Ranch (UHCR) geothermal system had seen no significant exploration activity prior to initiation of this GRED III project. Geochemical geothermometers calculated from previously available but questionable quality analyses of the UHCR hot spring waters indicated possible subsurface temperatures of +320 oF. A complex Quaternary and Holocene faulting pattern associated with a six mile step over of the Hot Creek Range near the UHCR also indicated that this area was worthy of some

248

Isotopic Analysis At Nw Basin & Range Region (Laney, 2005) | Open Energy  

Open Energy Info (EERE)

Isotopic Analysis At Nw Basin & Range Region (Laney, 2005) Isotopic Analysis At Nw Basin & Range Region (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Nw Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of

249

Origin And Characterization Of Geothermal Waters At Desert Queen, Nevada |  

Open Energy Info (EERE)

Origin And Characterization Of Geothermal Waters At Desert Queen, Nevada Origin And Characterization Of Geothermal Waters At Desert Queen, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Origin And Characterization Of Geothermal Waters At Desert Queen, Nevada Details Activities (1) Areas (1) Regions (0) Abstract: The Desert Queen geothermal system, which is in close proximity to two locations where geothermal energy is currently being harnessed, may host an additional reservoir. A _18O vs _D plot indicates that Desert Queen waters likely originate from the Humboldt River, and reflects Humboldt River water that is clearly evaporated. Temperatures of the reservoir at depth are estimated to be between 92-141°C and were calculated using the _18O(SO4-H2O) geothermometer. It is unclear whether these temperatures

250

Compound and Elemental Analysis At Buffalo Valley Hot Springs Area (Laney,  

Open Energy Info (EERE)

Compound and Elemental Analysis At Buffalo Valley Hot Compound and Elemental Analysis At Buffalo Valley Hot Springs Area (Laney, 2005) Exploration Activity Details Location Buffalo Valley Hot Springs Area Exploration Technique Compound and Elemental Analysis Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in

251

Property:ExplorationCostPerMetric | Open Energy Information  

Open Energy Info (EERE)

ExplorationCostPerMetric ExplorationCostPerMetric Jump to: navigation, search Property Name ExplorationCostPerMetric Property Type String Description the unit ratio denominator for exploration cost Allows Values 100 feet cut;30 foot core;compound;day;element;foot;hour;mile;point;process;sample;sq. mile;station;Subject;well Subproperties This property has the following 107 subproperties: A Active Seismic Methods Active Seismic Techniques Active Sensors Analytical Modeling B Borehole Seismic Techniques C Cation Geothermometers Chemical Logging Conceptual Model Core Holes Cross-Dipole Acoustic Log D DC Resistivity Survey (Dipole-Dipole Array) DC Resistivity Survey (Mise-Á-La-Masse) DC Resistivity Survey (Pole-Dipole Array) DC Resistivity Survey (Schlumberger Array) DC Resistivity Survey (Wenner Array)

252

Geothermometry At Nw Basin & Range Region (Laney, 2005) | Open Energy  

Open Energy Info (EERE)

Geothermometry At Nw Basin & Range Region (Laney, Geothermometry At Nw Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

253

Compound and Elemental Analysis At Northern Basin & Range Region (Laney,  

Open Energy Info (EERE)

Laney, Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Compound and Elemental Analysis At Northern Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Compound and Elemental Analysis Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being

254

Hydrothermal Heat Discharge In The Cascade Range, Northwestern United  

Open Energy Info (EERE)

Page Page Edit History Facebook icon Twitter icon » Hydrothermal Heat Discharge In The Cascade Range, Northwestern United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Hydrothermal Heat Discharge In The Cascade Range, Northwestern United States Details Activities (3) Areas (1) Regions (0) Abstract: Hydrothermal heat discharge in the Cascade Range includes the heat discharged by thermal springs, by "slightly thermal" springs that are only a few degrees warmer than ambient temperature, and by fumaroles. Thermal-spring heat discharge is calculated on the basis of chloride-flux measurements and geothermometer temperatures and totals ~ 240 MW in the U.S. part of the Cascade Range, excluding the transient post-1980 discharge

255

Interpretation of chemical analyses of waters collected from two geothermal  

Open Energy Info (EERE)

Interpretation of chemical analyses of waters collected from two geothermal Interpretation of chemical analyses of waters collected from two geothermal wells at Coso, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Interpretation of chemical analyses of waters collected from two geothermal wells at Coso, California Details Activities (1) Areas (1) Regions (0) Abstract: Wellhead and downhole water samples were collected and analyzed from a 114.3-m well at Coso Hot Springs (Coso No. 1) and a 1477-m well (CGEH No. 1) 3.2 km to the west. The same chloride concentration is present in hot waters entering both wells (about 2350 mg/kg), indicating that a hot-water-dominated geothermal system is present. The maximum measured temperatures are 142 degrees C in the Coso No. 1 well and 195 degrees C in the CGEH No. 1 well. Cation and sulfate isotope geothermometers indicate

256

Geothermometry At Walker-Lane Transitional Zone Region (Laney, 2005) | Open  

Open Energy Info (EERE)

Laney, 2005) Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Walker-Lane Transitional Zone Region (Laney, 2005) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being

257

Isotopic Analysis At Walker-Lane Transitional Zone Region (Laney, 2005) |  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Walker-Lane Transitional Isotopic Analysis- Fluid At Walker-Lane Transitional Zone Region (Laney, 2005) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in

258

Property:ExplorationTimePerMetric | Open Energy Information  

Open Energy Info (EERE)

ExplorationTimePerMetric ExplorationTimePerMetric Jump to: navigation, search Property Name ExplorationTimePerMetric Property Type String Description the unit ratio denominator for exploration time Allows Values job;10 mile;10 stn;100 mile;sq. mile;foot Subproperties This property has the following 121 subproperties: A Active Seismic Methods Active Seismic Techniques Active Sensors Analytical Modeling B Borehole Seismic Techniques C Cation Geothermometers Chemical Logging Compound and Elemental Analysis Conceptual Model Core Holes Cross-Dipole Acoustic Log D DC Resistivity Survey (Dipole-Dipole Array) DC Resistivity Survey (Mise-Á-La-Masse) DC Resistivity Survey (Pole-Dipole Array) DC Resistivity Survey (Schlumberger Array) DC Resistivity Survey (Wenner Array) Data Collection and Mapping Data Techniques

259

Isotopic Analysis At Central Nevada Seismic Zone Region (Laney, 2005) |  

Open Energy Info (EERE)

Laney, 2005) Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Central Nevada Seismic Zone Region (Laney, 2005) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being

260

Compound and Elemental Analysis At Nw Basin & Range Region (Laney, 2005) |  

Open Energy Info (EERE)

Nw Basin & Range Nw Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Compound and Elemental Analysis Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Thermal Waters Along The Konocti Bay Fault Zone, Lake County, California- A  

Open Energy Info (EERE)

Waters Along The Konocti Bay Fault Zone, Lake County, California- A Waters Along The Konocti Bay Fault Zone, Lake County, California- A Re-Evaluation Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Thermal Waters Along The Konocti Bay Fault Zone, Lake County, California- A Re-Evaluation Details Activities (3) Areas (1) Regions (0) Abstract: The Konocti Bay fault zone (KBFZ), initially regarded by some as a promising target for liquid-dominated geothermal systems, has been a disappointment. At least five exploratory wells were drilled in the vicinity of the KBFZ, but none were successful. Although the Na-K-Ca and Na-Li geothermometers indicate that the thermal waters discharging in the vicinity of Howard and Seigler Springs may have equilibrated at temperatures greater than 200°C, the spring temperatures and fluid

262

Isotopic Analysis At Northern Basin & Range Region (Laney, 2005) | Open  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Northern Basin & Range Isotopic Analysis- Fluid At Northern Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in

263

Geothermometry At Nevada Test And Training Range Area (Sabin, Et Al., 2004)  

Open Energy Info (EERE)

2004) 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Nevada Test And Training Range Area (Sabin, Et Al., 2004) Exploration Activity Details Location Nevada Test And Training Range Area Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown Notes Groundwater data are limited to a portion of NAFR; data are more plentiful beyond the range boundaries. Geothermometry yields calculated groundwater temperatures generally ranging from 30 to 105degrees C, with a rough correlation between the SiO2-chalcedony and the Na-K-Na (Mg-corrected) geothermometers. References A. E. Sabin, J. D. Walker, J. Unruh, F. C. Monastero (2004) Toward The Development Of Occurrence Models For Geothermal Resources In The

264

Water Sampling At Central Nevada Seismic Zone Region (Laney, 2005) | Open  

Open Energy Info (EERE)

Central Nevada Seismic Zone Region Central Nevada Seismic Zone Region (Laney, 2005) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Water Sampling Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

265

Water Sampling At Teels Marsh Area (Coolbaugh, Et Al., 2006) | Open Energy  

Open Energy Info (EERE)

Teels Marsh Area (Coolbaugh, Et Al., 2006) Teels Marsh Area (Coolbaugh, Et Al., 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Water Sampling At Teels Marsh Area (Coolbaugh, Et Al., 2006) Exploration Activity Details Location Teels Marsh Area Exploration Technique Water Sampling Activity Date Usefulness useful DOE-funding Unknown Notes Follow up (to ASTER satellite imaging) analysis of spring and well waters yielded geothermometer reservoir estimates up to 192°C References Mark F. Coolbaugh, Chris Kraft, Chris Sladek, Richard E. Zehner, Lisa Shevenell (2006) Quaternary Borate Deposits As A Geothermal Exploration Tool In The Great Basin Retrieved from "http://en.openei.org/w/index.php?title=Water_Sampling_At_Teels_Marsh_Area_(Coolbaugh,_Et_Al.,_2006)&oldid=388168

266

Property:LithologyInfo | Open Energy Information  

Open Energy Info (EERE)

LithologyInfo LithologyInfo Jump to: navigation, search Property Name LithologyInfo Property Type Text Subproperties This property has the following 93 subproperties: 2 2-M Probe Survey A Active Seismic Methods Active Sensors Aerial Photography Aeromagnetic Survey Analytical Modeling C Caliper Log Cation Geothermometers Cement Bond Log Chemical Logging Compound and Elemental Analysis Conceptual Model Controlled Source Frequency-Domain Magnetics Cross-Dipole Acoustic Log D Data Acquisition-Manipulation Data Collection and Mapping Data Techniques Data and Modeling Techniques Drilling Methods E Electric Micro Imager Log Electromagnetic Sounding Methods Elemental Analysis with Fluid Inclusion F FLIR Fault Mapping Field Techniques Flow Test Fluid Inclusion Analysis Fluid Lab Analysis Formation Testing Techniques

267

Geothermometry At Clear Lake Area (Thompson, Et Al., 1992) | Open Energy  

Open Energy Info (EERE)

Clear Lake Area (Thompson, Et Al., 1992) Clear Lake Area (Thompson, Et Al., 1992) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Clear Lake Area (Thompson, Et Al., 1992) Exploration Activity Details Location Clear Lake Area Exploration Technique Geothermometry Activity Date Usefulness useful DOE-funding Unknown Notes Based on the above discussion, we favor a model in which thermal water rises somewhere between Howard and Seigler Springs. At Howard Springs we see evidence for the most representative deep thermal water because the C1 is elevated (highest measured C1 concentrations occur at Howard Springs). Moreover, the Na-Li, Na-K and Na-K-Ca geothermometers suggest temperatures greater than 240 degrees C. References J. M. Thompson, R. H. Mariner, L. D. White, T. S. Presser, W. C.

268

Colorado's hydrothermal resource base: an assessment  

DOE Green Energy (OSTI)

As part of its effort to more accurately describe the nations geothrmal resource potential, the US Department of Energy/Division of Geothermal Energy contracted with the Colorado Geological survey to appraise the hydrothermal (hot water) geothermal resources of Colorado. Part of this effort required that the amount of energy that could possibly be contained in the various hydrothermal systems in Colorado be estimated. The findings of that assessment are presented. To make these estimates the geothermometer reservoir temperatures estimated by Barrett and Pearl (1978) were used. In addition, the possible reservoir size and extent were estimated and used. This assessment shows that the total energy content of the thermal systems in Colorado could range from 4.872 x 10{sup 15} BTU's to 13.2386 x 10{sup 15} BTU's.

Pearl, R.H.

1981-01-01T23:59:59.000Z

269

The Geyser Bight geothermal area, Umnak Island, Alaska  

DOE Green Energy (OSTI)

The Geyser Bight geothermal area contains one of the hottest and most extensive areas of thermal springs in Alaska, and is the only site in the state with geysers. Heat for the geothermal system is derived from crustal magma associated with Mt. Recheshnoi volcano. Successive injections of magma have probably heated the crust to near its minimum melting point and produced the only high-SiO[sub 2] rhyolites in the oceanic part of the Aleutian arc. At least two hydrothermal reservoirs are postulated to underlie the geothermal area and have temperatures of 165 and 200 C, respectively, as estimated by geothermometry. Sulfate-water isotope geothermometers suggest a deeper reservoir with a temperature of 265 C. The thermal spring waters have relatively low concentrations of Cl (600 ppm) but are rich in B (60 ppm) and As (6 ppm). The As/Cl ratio is among the highest reported for geothermal waters. 41 refs., 12 figs., 8 tabs.

Motyka, R.J. (Alaska Div. of Geological and Geophysical Surveys, Juneau, AK (United States)); Nye, C.J. (Alaska Div. of Geological and Geophysical Surveys, Fairbanks, AK (United States) Univ. of Alaska, Fairbanks, AK (United States). Geophysical Inst.); Turner, D.L. (Univ. of Alaska, Fairbanks, AK (United States). Geophysical Inst.); Liss, S.A. (Alaska Div. of Geological and Geophysical Surveys, Fairbanks, AK (United States))

1993-08-01T23:59:59.000Z

270

Property:HydroInfo | Open Energy Information  

Open Energy Info (EERE)

HydroInfo HydroInfo Jump to: navigation, search Property Name HydroInfo Property Type Text Subproperties This property has the following 77 subproperties: 2 2-M Probe Survey A Acoustic Logs Active Seismic Methods Aeromagnetic Survey Analytical Modeling C Caliper Log Cation Geothermometers Cement Bond Log Conceptual Model Core Analysis Core Holes Cuttings Analysis D Data Acquisition-Manipulation Data Techniques Data and Modeling Techniques Drilling Methods E Electric Micro Imager Log Electromagnetic Sounding Methods Elemental Analysis with Fluid Inclusion F FLIR Formation Testing Techniques Frequency-Domain Electromagnetic Survey G Gamma Log Gas Flux Sampling Gas Geothermometry Geochemical Data Analysis G cont. Geochemical Techniques Geodetic Survey Geophysical Methods Geothermal Literature Review

271

Water Sampling At Walker-Lane Transitional Zone Region (Laney, 2005) | Open  

Open Energy Info (EERE)

Water Sampling At Walker-Lane Transitional Zone Water Sampling At Walker-Lane Transitional Zone Region (Laney, 2005) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Water Sampling Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in

272

Water Sampling At Buffalo Valley Hot Springs Area (Laney, 2005) | Open  

Open Energy Info (EERE)

Water Sampling At Buffalo Valley Hot Springs Area Water Sampling At Buffalo Valley Hot Springs Area (Laney, 2005) Exploration Activity Details Location Buffalo Valley Hot Springs Area Exploration Technique Water Sampling Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

273

Water Sampling At Nw Basin & Range Region (Laney, 2005) | Open Energy  

Open Energy Info (EERE)

Water Sampling At Nw Basin & Range Region (Laney, Water Sampling At Nw Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Water Sampling Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in 2004. Samples are now being collected at sites identified by other

274

Compound and Elemental Analysis At Clear Lake Area (Thompson, Et Al., 1992)  

Open Energy Info (EERE)

Et Al., 1992) Et Al., 1992) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Compound and Elemental Analysis At Clear Lake Area (Thompson, Et Al., 1992) Exploration Activity Details Location Clear Lake Area Exploration Technique Compound and Elemental Analysis Activity Date Usefulness useful DOE-funding Unknown Notes Based on the above discussion, we favor a model in which thermal water rises somewhere between Howard and Seigler Springs. At Howard Springs we see evidence for the most representative deep thermal water because the C1 is elevated (highest measured C1 concentrations occur at Howard Springs). Moreover, the Na-Li, Na-K and Na-K-Ca geothermometers suggest temperatures greater than 240 degrees C. References J. M. Thompson, R. H. Mariner, L. D. White, T. S. Presser, W. C.

275

Geothermometry At Buffalo Valley Hot Springs Area (Laney, 2005) | Open  

Open Energy Info (EERE)

Buffalo Valley Hot Springs Area (Laney, 2005) Buffalo Valley Hot Springs Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermometry At Buffalo Valley Hot Springs Area (Laney, 2005) Exploration Activity Details Location Buffalo Valley Hot Springs Area Exploration Technique Geothermometry Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being

276

CX-007389: Categorical Exclusion Determination | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

89: Categorical Exclusion Determination 89: Categorical Exclusion Determination CX-007389: Categorical Exclusion Determination Advances in Hydrogeochemical Indicators for the Discovery of New Geothermal Resources in the Great Basin CX(s) Applied: A9, B3.6 Date: 12/21/2011 Location(s): Colorado Offices(s): Golden Field Office The Colorado School of Mines (CSM) would utilize DOE and cost share funds to develop and calibrate new hydrogeochemical indicators and geothermometers for cost effective discovery and management of geothermal resources specific to the Great Basin. Laboratory work would occur at the Department of Geology and Geological Engineering at CSM in Golden, CO. CX-007389.pdf More Documents & Publications CX-007391: Categorical Exclusion Determination CX-005689: Categorical Exclusion Determination

277

Isotopic Analysis At Buffalo Valley Hot Springs Area (Laney, 2005) | Open  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Buffalo Valley Hot Isotopic Analysis- Fluid At Buffalo Valley Hot Springs Area (Laney, 2005) Exploration Activity Details Location Buffalo Valley Hot Springs Area Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Geochemical Sampling of Thermal and Non-thermal Waters in Nevada, Shevenell and Garside. The objective of this project is to obtain geochemical data from springs (and some wells) for which data are not publicly available, or for which the analyses are incomplete, poor, or nonexistent. With these data, geothermometers are being calculated and a preliminary assessment of the geothermal potential and ranking of the sampled areas is being conducted using the new geochemical data. Objectives changed slightly in

278

Robust conductive mesoporous carbon?silica composite films with highly ordered and oriented orthorhombic structures from triblock-copolymer template co-assembly  

Science Conference Proceedings (OSTI)

In this work, we describe a facile approach to improve the robustness of conductive mesoporous carbon-based thin films by the addition of silica to the matrix through the triconstituent organic-inorganic-organic co-assembly of resol (carbon precursor) and tetraethylorthosilicate (silica precursor) with triblock-copolymer Pluronic F127. The pyrolysis of the resol-silica-pluronic F127 film yields a porous composite thin film with well-defined mesostructure. X-Ray diffraction (XRD), grazing incidence small angle X-ray scattering (GISAXS), and electron microscopy measurements indicate that the obtained carbon-based thin films have a highly ordered orthorhombic mesostructure (Fmmm) with uniform large pore size ({approx}3 nm). The orthorhombic mesostructure is oriented and the (010) plane is parallel to the silicon wafer substrate. The addition of silica to the matrix impacts the pore size, surface area, porosity, modulus and conductivity. For composite films with approximately 40 wt% silica, the conductivity is decreased by approximately an order of magnitude in comparison to a pure carbon mesoporous film, but the conductivity is comparable to typical printed carbon inks used in electrochemical sensing, {approx}10 S cm{sup -1}. The mechanical properties of these mesoporous silica-carbon hybrid films are similar to the pure carbon analogs with a Young's modulus between 10 GPa and 15 GPa, but the material is significantly more porous. Moreover, the addition of silica to the matrix appears to improve the adhesion of the mesoporous film to a silicon wafer. These mesoporous silica-carbon composite films have appropriate characteristics for use in sensing applications.

Song, Lingyan; Feng, Dan; Campbell, Casey G.; Gu, Dong; Forster, Aaron M.; Yager, Kevin G.; Fredin, Nathaniel; Lee, Hae-Jeong; Jones, Ronald L.; Zhao, Dongyuan; Vogt, Bryan D. (AZU)

2012-07-11T23:59:59.000Z

279

An AC phase measuring interferometer for measuring dn/dT of fused silica and calcium fluoride at 193 nm  

Science Conference Proceedings (OSTI)

A novel method for the measurement of the change in index of refraction vs. temperature (dn/dT) of fused silica and calcium fluoride at the 193 nm wavelength has been developed in support of thermal modeling efforts for the development of 193 nm-based photolithographic exposure tools. The method, based upon grating lateral shear interferometry, uses a transmissive linear grating to divide a 193 nm laser beam into several beam paths by diffraction which propagate through separate identical material samples. One diffracted order passing through one sample overlaps the undiffracted beam from a second sample and forms interference fringes dependent upon the optical path difference between the two samples. Optical phase delay due to an index change from heating one of the samples causes the interference fringes to change sinusoidally with phase. The interferometer also makes use of AC phase measurement techniques through lateral translation of the grating. Results for several samples of fused silica and calcium fluoride are demonstrated.

Shagam, R.N.

1998-09-01T23:59:59.000Z

280

Effect of high silica content on scale deposition and pipe-wall loss in oilfield steam generators  

Science Conference Proceedings (OSTI)

Studies were conducted on site in the Coalinga, Belridge, and Midway Sunset fields in California to research the cause of metal losses detected in the radiant section return bends and immediate piping downstream form the stem generators. This paper reports on the surveillance of silica content in the influent and effluent streams of the selected steam generators and the results of X-ray inspection of bends, elbows, welds, and pipings which indicated that a correlation is likely to exist between the silica and bicarbonate concentration in the feedwater and the silicate scale buildup, and incident rate of wall loss and the cause of wall loss/pipe failures is a combination of corrosion and erosion mechanisms accelerated at higher steam qualities.

Khatib, Z.I.; Olson, E.E.; Place, M.C. Jr. (Shell Development Co., Houston, TX (United States))

1992-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Electron-beam induced electric-hydraulic expansion in a silica-shelled gallium microball-nanotube structure  

Science Conference Proceedings (OSTI)

Heteroshape-heteroscale structure of silica-shelled Ga microball-nanotube was fabricated. Under in situ electron-beam irradiation, an abnormally large and fast expansion of Ga was observed. Failed by a sole routine heating effect of electron-beam, the expansion was explained by an electric-hydraulic expansion effect taking into account a huge inner pressure induced by the repelling Coulomb force of positively charged Ga ions on the Ga microball surface. The ions were accumulated due to knocking-out of Ga electrons under irradiation and shielding effect of a silica shell which prevents the charge balance restoration. A circuit model is proposed to calculate the accumulation of Ga ions.

Gao, Y. H.; Sun, M.; Su, J. [Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology (HUST), LuoyuRoad 1037, Wuhan 430074 (China); Zhi, C. Y.; Golberg, D.; Bando, Y. [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan); Duan, X. F. [Institute of Physics, Beijing National Laboratory of Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2011-08-22T23:59:59.000Z

282

Silane Modification of Glass and Silica Surfaces to Obtain Equally Oil-Wet Surfaces in Glass-Covered Silicon Micromodel Applications  

SciTech Connect

The wettability of silicon and glass surfaces can be modified by silanization. However, similar treatments of glass and silica surfaces using the same silane do not necessarily yield the same wettability as determined by the oil-water contact angle. In this technical note, surface cleaning pretreatments were investigated to determine conditions that would yield oil-wet surfaces on glass with similar wettability to silica surfaces treated with the same silane, and both air-water and oil-water contact angles were determined. Air-water contact angles were less sensitive to differences between silanized silica and glass surfaces, often yielding similar values while the oil-water contact angles were quite different. Borosilicate glass surfaces cleaned with standard cleaning solution 1 (SC1) yield intermediate-wet surfaces when silanized with hexamethyldisilazane, while the same cleaning and silanization yields oil-wet surfaces on silica. However, cleaning glass in boiling concentrated nitric acid creates a surface that can be silanized to obtain oil-wet surfaces using HDMS. Moreover, this method is effective on glass with prior thermal treatment at an elevated temperature of 400oC. In this way, silica and glass can be silanized to obtain equally oil-wet surfaces using HMDS. It is demonstrated that pretreatment and silanization is feasible in silicon-silica/glass micromodels previously assembled by anodic bonding, and that the change in wettability has a significant observable effect on immiscisble fluid displacements in the pore network.

Grate, Jay W.; Warner, Marvin G.; Pittman, Jonathan W.; Dehoff, Karl J.; Wietsma, Thomas W.; Zhang, Changyong; Oostrom, Martinus

2013-08-05T23:59:59.000Z

283

Eighth CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag, and Natural Pozzolans in Concrete  

Science Conference Proceedings (OSTI)

The nine papers in this CD are collected by the U. S. Advisory Committee for presentation at the Eighth CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag, and Natural Pozzolans in Concrete, May 23–29, 2004, Las Vegas, Nevada. They are being published by EPRI, Palo Alto, CA to make them available to all attendees, and other interested people, in a compact form for future reference and use.

2004-05-05T23:59:59.000Z

284

Geochemistry of thermal/mineral waters in the Clear Lake region, California, and implications for hot dry rock geothermal development  

DOE Green Energy (OSTI)

Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connote types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast, ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connote end-members. The latter end-member has enriched [delta]D as well as enriched d[sup l8]O, very different from typical high-temperature geothermal reservoir waters. Tritium data and modeling of ages indicate most Clear Lake region waters are 500 to > 10,000 yr., although mixing of old and young components is implied by the data. The age of end-member connate water is probably > 10,000 yr. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is [le] 150[degrees]C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures [le] 150[degrees]C (except for Sulphur Bank Mine). Hot dry rock technologies are the best way to commercially exploit the known high temperatures existing beneath the Clear Lake region, particularly within the main Clear Lake volcanic field.

Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.; Mansfield, J.

1993-02-01T23:59:59.000Z

285

Hydrogeochemical evaluation of conventional and hot dry rock geothermal resource potential in the Clear Lake region, California  

DOE Green Energy (OSTI)

Chemistry, stable isotope, and tritium contents of thermal/mineral waters in the Clear Lake region were used to evaluate conventional and hot dry rock (HDR) geothermal potential for electrical generation. Thermal/mineral waters of the Clear Lake region are broadly classified as thermal meteoric and connate types based on chemical and isotopic criteria. Ratios of conservative components such as B/Cl are extremely different among all thermal/mineral waters of the Clear Lake region except for clusters of waters emerging from specific areas such as the Wilbur Springs district and the Agricultural Park area south of Mt. Konocti. In contrast ratios of conservative components in large, homogeneous geothermal reservoirs are constant. Stable isotope values of Clear Lake region waters show a mixing trend between thermal meteoric and connate (generic) end-members. The latter end-member has enriched {delta}D as well as enriched {delta}{sup 18}O, from typical high-temperature geothermal reservoir waters. Tritium data indicate most Clear Lake region waters are mixtures of old and young fluid components. Subsurface equilibration temperature of most thermal/mineral waters of the Clear Lake region is {le}150{degree}C based on chemical geothermometers but it is recognized that Clear Lake region waters are not typical geothermal fluids and that they violate rules of application of many geothermometers. The combined data indicate that no large geothermal reservoir underlies the Clear Lake region and that small localized reservoirs have equilibration temperatures {le}150{degree}C (except for Sulphur Bank mine). HDR technologies are probably the best way to commercially exploit the known high-temperatures existing beneath the Clear Lake region particularly within and near the main Clear Lake volcanic field.

Goff, F.; Adams, A.I.; Trujillo, P.E.; Counce, D.

1993-05-01T23:59:59.000Z

286

Cr(VI) adsorption on functionalized amorphous and mesoporous silica from aqueous and non-aqueous media  

Science Conference Proceedings (OSTI)

A mesoporous silica (SBA-15) and amorphous silica (SG) have been chemically modified with 2-mercaptopyridine using the homogeneous route. This synthetic route involved the reaction of 2-mercaptopyridine with 3-chloropropyltriethoxysilane prior to immobilization on the support. The resulting material has been characterized by powder X-ray diffraction, nitrogen gas sorption, FT-IR and MAS NMR spectroscopy, thermogravimetry and elemental analysis. The solid was employed as a Cr(VI) adsorbent from aqueous and non-aqueous solutions at room temperature. The effect of several variables (stirring time, pH, metal concentration and solvent polarity) has been studied using the batch technique. The results indicate that under the optimum conditions, the maximum adsorption value for Cr(VI) was 1.83 {+-} 0.03 mmol/g for MP-SBA-15, whereas the adsorption capacity of the MP-SG was 0.86 {+-} 0.02 mmol/g. On the basis of these results, it can be concluded that it is possible to modify chemically SBA-15 and SG with 2-mercaptopyridine and to use the resulting modified silicas as effective adsorbents for Cr(VI)

Perez-Quintanilla, Damian [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain)]. E-mail: damian.perez@urjc.es; Hierro, Isabel del [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Fajardo, Mariano [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Sierra, Isabel [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain)]. E-mail: isabel.sierra@urjc.es

2007-08-07T23:59:59.000Z

287

A New Concept for the Fabrication of Hydrogen Selective Silica Membranes  

DOE Green Energy (OSTI)

It is attempted to synthesize hydrogen selective silica-based membranes through a novel thin film deposition concept. This report describes the progress made during the 1st Year of this award. All project Tasks, for Year 1, were completed and the first thin films were prepared and characterized. The goal of this work is to use crystalline layered silicates to form hydrogen selective membranes for use in high temperature hydrogen/carbon dioxide separations. It was proposed to: (A) Synthesize layered silicate materials; (B) Prepare dispersions of as synthesized or delaminated layered silicates; (C) Prepare membranes by coating the layered silicates on macro-mesoporous supports; and (D) Test the membranes for H{sub 2}/CO{sub 2} selectivity at high temperature and pressures and for structural and functional stability at high temperature in the presence of water vapor. All Year 1 project Tasks are completed. Layered silicate particles were synthesized hydrothermally. Crystal shape and size was optimized for the formation of thin films. Calcination procedures that avoid particle agglomeration were developed and suspensions of the calcined silicate particles were prepared. The silicate particles and suspensions were characterized by X-Ray Diffraction, Electron Microscopy and Dynamic Light Scattering. The characterization data indicate that plate like morphology, large aspect ratio and good dispersion have been achieved. A deposition process that leads to uniform, high-coverage ({approx}100%) coating of the layered silicate particles on porous alpha-alumina supports was developed.

Michael Tsapatsis

2005-10-01T23:59:59.000Z

288

Enzymatic Conversion of CO2 to Bicarbonate in Functionalized Mesoporous Silica  

Science Conference Proceedings (OSTI)

We report here that carbonic anhydrase (CA), the fastest enzyme that can covert carbon dioxide to bicarbonate, can be spontaneously entrapped in functionalized mesoporous silica (FMS) with super-high loading density (up to 0.5 mg of protein/mg of FMS) due to the dominant electrostatic interaction. The binding of CA to HOOC-FMS can result in the protein’s conformational change comparing to the enzyme free in solution, but can be overcome with increased protein loading density. The higher the protein loading density, the less conformational change, hence the higher enzymatic activity and the higher enzyme immobilization efficiency. The electrostatically bound CA can be released by changing pH. The released enzyme still displayed the native conformational structure and the same high enzymatic activity as that prior to the enzyme entrapment. This work opens up a new approach converting carbon dioxide to biocarbonate in a biomimetic nanoconfiguration that can be integrated with the other part of biosynthesis process for the assimilation of carbon dioxide.

Yu, Yuehua; Chen, Baowei; Qi, Wen N.; Li, Xiaolin; Shin, Yongsoon; Lei, Chenghong; Liu, Jun

2012-05-01T23:59:59.000Z

289

Helium Adsorption in Silica Aerogel near the Liquid-Vapor Critical Point  

E-Print Network (OSTI)

We have investigated the adsorption and desorption of helium near its liquid-vapor critical point in silica aerogels with porosities between 95 % and 98%. We used a capacitive measurement technique which allowed us to probe the helium density inside the aerogel directly, even though the samples were surrounded by bulk helium. The aerogel’s very low thermal conductivity resulted in long equilibration times so we monitored the pressure and the helium density, both inside the aerogel and in the surrounding bulk, and waited at each point until all had stabilized. Our measurements were made at temperatures far from the critical point, where a well defined liquid-vapor interface exists, and at temperatures up to the bulk critical point. Hysteresis between adsorption and desorption isotherms persisted to temperatures close to the liquid-vapor critical point and there was no sign of an equilibrium liquid-vapor transition once the hysteresis disappeared. Many features of our isotherms can be described in terms of capillary condensation, although this picture becomes less applicable as the liquid-vapor critical point is approached and it is unclear how it can be applied to aerogels, whose tenuous structure includes a wide range of length scales. I.

Tobias Herman; James Day; John Beamish

2008-01-01T23:59:59.000Z

290

Compressed Silica Aerogels for the Study of Superfluid [superscript 3]He  

SciTech Connect

We have performed Small Angle X-ray Scattering (SAXS) on uniaxially strained aerogels and measured the strain-induced structural anisotropy. We use a model to connect our SAXS results to anisotropy of the {sup 3}He quasiparticle mean free path in aerogel. Measurements of the low temperature phase diagram of superfluid {sup 3}He in 98% aerogel indicate a stable B-phase and a metastable A-like phase. Vicente et al. proposed that the relative stability of these phases can be attributed to local anisotropic scattering of the 3He quasiparticles by the aerogel network. This network consists of silica strands with a diameter of {approx} 30 {angstrom} and average separation {zeta}{sub a} {approx} 300 {angstrom}. Vicente et al. also proposed using uniaxial strain of the aerogel to produce global anisotropy. We have performed SAXS on two uniaxially strained aerogels and found that strain introduces anisotropy on the {approx}100 {angstrom} length scale. We relate this to anisotropy of the quasiparticle mean free path, {lambda}.

Pollanen, J.; Choi, H.; Davis, J.P.; Blinstein, S.; Lippman, T.M.; Lurio, L.B.; Mulders, N.; Halperin, W.P. (NIU); (Delaware); (NWU)

2007-03-02T23:59:59.000Z

291

FUNCTIONALIZED SILICA AEROGELS: ADVANCED MATERIALS TO CAPTURE AND IMMOBILIZE RADIOACTIVE IODINE  

Science Conference Proceedings (OSTI)

To support the future expansion of nuclear energy, an effective method is needed to capture and safely store radiological iodine-129 released during reprocessing of spent nuclear fuel. Various materials have been investigated to capture and immobilize iodine. In most cases, however, the materials that are effective for capturing iodine cannot subsequently be sintered/densified to create a stable composite that could be a viable waste form. We have developed chemically modified, highly porous, silica aerogels that show sorption capacities higher than 440 mg of I2 per gram at 150 C. An iodine uptake test in dry air containing 4.2 ppm of iodine demonstrated no breakthrough after 3.5 h and indicated a decontamination factor in excess of 310. Preliminary densification tests showed that the I2-loaded aerogels retained more than 92 wt% of I2 after thermal sintering with pressure assistance at 1200 C for 30 min. These high capture and retention efficiencies for I2 can be further improved by optimizing the functionalization process and the chemistry as well as the sintering conditions.

Matyas, Josef; Fryxell, Glen E.; Busche, Brad J.; Wallace, Krys; Fifield, Leonard S.

2011-11-16T23:59:59.000Z

292

Helium adsorption in silica aerogel near the liquid-vapor critical point  

E-Print Network (OSTI)

We have investigated the adsorption and desorption of helium near its liquid-vapor critical point in silica aerogels with porosities between 95% and 98%. We used a capacitive measurement technique which allowed us to probe the helium density inside the aerogel directly, even though the samples were surrounded by bulk helium. The aerogel's very low thermal conductivity resulted in long equilibration times so we monitored the pressure and the helium density, both inside the aerogel and in the surrounding bulk, and waited at each point until all had stabilized. Our measurements were made at temperatures far from the critical point, where a well defined liquid-vapor interface exists, and at temperatures up to the bulk critical point. Hysteresis between adsorption and desorption isotherms persisted to temperatures close to the liquid-vapor critical point and there was no sign of an equilibrium liquid-vapor transition once the hysteresis disappeared. Many features of our isotherms can be described in terms of capillary condensation, although this picture becomes less applicable as the liquid-vapor critical point is approached and it is unclear how it can be applied to aerogels, whose tenuous structure includes a wide range of length scales.

Tobias Herman; James Day; John Beamish

2005-05-18T23:59:59.000Z

293

Tuning the properties of Ge-quantum dots superlattices in amorphous silica matrix through deposition conditions  

Science Conference Proceedings (OSTI)

In this work, we investigate the structural properties of Ge quantum dot lattices in amorphous silica matrix, prepared by low-temperature magnetron sputtering deposition of (Ge+SiO{sub 2})/SiO{sub 2} multilayers. The dependence of quantum dot shape, size, separation, and arrangement type on the Ge-rich (Ge + SiO{sub 2}) layer thickness is studied. We show that the quantum dots are elongated along the growth direction, perpendicular to the multilayer surface. The size of the quantum dots and their separation along the growth direction can be tuned by changing the Ge-rich layer thickness. The average value of the quantum dots size along the lateral (in-plane) direction along with their lateral separation is not affected by the thickness of the Ge-rich layer. However, the thickness of the Ge-rich layer significantly affects the quantum dot ordering. In addition, we investigate the dependence of the multilayer average atomic composition and also the quantum dot crystalline quality on the deposition parameters.

Pinto, S. R. C.; Ramos, M. M. D.; Gomes, M. J. M. [University of Minho, Centre of Physics and Physics Department, Braga 4710-057 (Portugal); Buljan, M. [Ruder Boskovic Institute, Bijenicka cesta 54, Zagreb 10000 (Croatia); Chahboun, A. [University of Minho, Centre of Physics and Physics Department, Braga 4710-057 (Portugal); Physics Department, FST Tanger, Tanger BP 416 (Morocco); Roldan, M. A.; Molina, S. I. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. I., Universidad de Cadiz, Cadiz (Spain); Bernstorff, S. [Sincrotrone Trieste, SS 14 km163, 5, Basovizza 34012 (Italy); Varela, M.; Pennycook, S. J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Barradas, N. P.; Alves, E. [Instituto Superior Tecnico e Instituto Tecnologico e Nuclear-, EN10, Sacavem 2686-953 (Portugal)

2012-04-01T23:59:59.000Z

294

Tuning the properties of Ge-quantum dots superlattices in amorphous silica matrix through deposition conditions  

Science Conference Proceedings (OSTI)

In this work, we investigate the structural properties of Ge quantum dot lattices in amorphous silica matrix, prepared by low-temperature magnetron sputtering deposition of (Ge+SiO{sub 2})/SiO{sub 2} multilayers. The dependence of quantum dot shape, size, separation, and arrangement type on the Ge-rich (Ge + SiO{sub 2}) layer thickness is studied. We show that the quantum dots are elongated along the growth direction, perpendicular to the multilayer surface. The size of the quantum dots and their separation along the growth direction can be tuned by changing the Ge-rich layer thickness. The average value of the quantum dots size along the lateral (in-plane) direction along with their lateral separation is not affected by the thickness of the Ge-rich layer. However, the thickness of the Ge-rich layer significantly affects the quantum dot ordering. In addition, we investigate the dependence of the multilayer average atomic composition and also the quantum dot crystalline quality on the deposition parameters.

Pinto, S. [University of Minho, Portugal; Roldan Gutierrez, Manuel A [ORNL; Ramos, M. M.D. [University of Minho, Portugal; Gomes, M.J.M. [University of Minho, Portugal; Molina, S. I. [Universidad de Cadiz, Spain; Pennycook, Stephen J [ORNL; Varela del Arco, Maria [ORNL; Buljan, M. [R. Boskovic Institute, Zagreb, Croatia; Barradas, N. [Instituto Tecnologico e Nuclear (ITN), Lisbon, Portugal; Alves, E. [Instituto Tecnologico e Nuclear (ITN), Lisbon, Portugal; Chahboun, A. [FST Tanger, Morocco; Bernstorff, S. [Sincrotrone Trieste, Basovizza, Italy

2012-01-01T23:59:59.000Z

295

Pyrolysis and hydropyrolysis of diphenylmethane and sulphur-containing compounds immobilised on silica  

DOE Green Energy (OSTI)

The use of high pressures and dispersed catalysts, such as sulphided molybdenum (Mo) in fixed-bed hydropyrolysis of coals give rise to increased tar yields. In order to improve our understanding of these phenomena, Particularly in relation to cleavage of C-C and C-S bonds, experiments have been conducted on samples of silica-immobilised benzene, diphenylmethane, thioanisole and dibenzothiophene (DBT). These model substrates have the inherent advantage that they do not soften and thus stay in the reactor. Moreover, for the surface-immobilized benzene, the SiO-C bond linking the substrate to the surface is reasonably stable and does not show significant cleavage until 550{degrees}C (peak maximum) with a high yield of benzene being achieved at 150 bar hydrogen pressure. For the diphenylmethane substrate, the use of 150 bar hydrogen pressure and the Mo catalyst both reduced the peak evolution temperatures for benzene and toluene clearly demonstrating their separate contributions to promoting C-C bond cleavage. Desulphurisation of the DBT substrate occurred only in hydrogen and the thermal decomposition of the thioanisole substrate was altered markedly by the Mo catalyst.

Mitchell, S.C.; Lafferty, C.J.; Garcia, R.; Ismail, K.; Snape, C.E. [Strathclyde Univ., Glasgow (United Kingdom). Dept. of Pure and Applied Chemistry; Buchanan, A.C. III; Britt, P.F. [Oak Ridge National Lab., TN (United States); Klavetter, E. [Sandia National Labs., Albuquerque, NM (United States); en

1992-08-01T23:59:59.000Z

296

Thermal and solar-optical properties of silica aerogel for use in insulated windows  

SciTech Connect

Silica aerogel is a porous insulating material that is transport to solar radiation. To understand its insulating performance in a window system, it is necessary to first study component heat transfer paths. Aerogel's absorption coefficient, a measure of the attenuation of radiation heat transfer, was determined over the spectral range 1-200 ..mu..m. Although radiation heat transfer is negligible over much of this region, there is a transmission window between 3-6 ..mu..m. At ambient temperatures, for aerogel thicknesses of 0.5-5.0 cm, radiation heat transfer through an unmodified aerogel window is less than 15% of the total heat flux. For evacuated or high-temperature furnace windows, this contribution can be over 50%. Thermal radiative transfer can be somewhat decreased by allowing the aerogel to absorb moisture, but solar transmission and optical clarity are sacrificed. Absorption of water vapor over time causes irreversible structural changes that increase scattering in the solar spectrum. Aerogel's thermal performance can be improved by replacing the pore gas with one of lower conductivity or by evacuating the aerogel to pressure below 0.1 atm. A hypothetical evacuated aerogel window has a calcuated U-Value of approx. =0.5 W/m/sup 2/-K for a gap spacing of 12.5 mm, which is four times better than currently available low-emissivity gas-filled units of similar size. 8 refs., 9 figs.

Hartmann, J.; Rubin, M.; Arasteh, D.

1987-06-01T23:59:59.000Z

297

Elastic properties of silica aerogels from a new rapid supercritical extraction process  

Science Conference Proceedings (OSTI)

Silica aerogels were produced by a new process from Tetramethoxysilane (TMOS) with ammonia as base catalyst. the process involves pouring the liquid sol in a stainless steel mold and immediately heating it to supercritical conditions. Gelation and aging occurs during heating and reaction rates are high die to high average temperatures. the gel fills the container completely, which enables relatively fast venting of the supercritical fluid by providing a constraint for swelling and failure of the gel monolith. The whole process can be completed in 6 h or less. Longitudinal and shear moduli were measured in the dried aerogels by ultrasonic velocity measurements both as a function of chemical composition of the original sol and of position in the aerogel. It was found that the sound velocity exhibits marked maxima on the surface of the cylindrical specimens and specifically close to the ends, where the fluid left during venting. Specimens with high catalyst concentration and high water:TMOS ratio exhibited higher average moduli.

Gross, J.; Coronado, P.R.; Hair, L.M.; Hrubesh, L.W.

1997-08-11T23:59:59.000Z

298

Corrugation of Phase-Separated Lipid Bilayers Supported by Nanoporous Silica Xerogel Surfaces  

Science Conference Proceedings (OSTI)

Lipid bilayers supported by substrates with nanometer-scale surface corrugations holds interest in understanding both nanoparticle-membrane interactions and the challenges of constructing models of cell membranes on surfaces with desirable properties, e.g. porosity. Here, we successfully form a two-phase (gel-fluid) lipid bilayer supported by nanoporous silica xerogel. Surface topology, diffusion, and lipid density in comparison to mica-supported lipid bilayers were characterized by AFM, FRAP, FCS, and quantitative fluorescence microscopy, respectively. We found that the two-phase lipid bilayer follows the xerogel surface contours. The corrugation imparted on the lipid bilayer results in a lipid density that is twice that on a flat mica surface. In direct agreement with the doubling of actual bilayer area in a projected area, we find that the lateral diffusion coefficient (D) of lipids on xerogel ({approx}1.7 {micro}m{sup 2}/s) is predictably lower than on mica ({approx}4.1 {micro}m{sup 2}/s) by both FRAP and FCS techniques. Furthermore, the gel-phase domains on xerogel compared to mica were larger and less numerous. Overall, our results suggest the presence of a relatively defect-free continuous two-phase bilayer that penetrates approximately midway into the first layer of {approx}50 nm xerogel beads.

Goksu, E I; Nellis, B A; Lin, W; Satcher Jr., J H; Groves, J T; Risbud, S H; Longo, M L

2008-10-30T23:59:59.000Z

299

The effect of particle-particle interaction forces on the flow properties of silica slurries  

SciTech Connect

Preliminary work has been completed to investigate the effect of particle-particle interaction forces on the flow properties of silica slurries. Classically hydro-transport studies have focused on the flow of coarse granular material in Newtonian fluids. However, with current economical and environmental pressures, the need to increase solid loadings in pipe flow has lead to studies that examine non-Newtonian fluid dynamics. The flow characteristics of non-Newtonian slurries can be greatly influenced through controlling the solution chemistry. Here we present data on an 'ideal' slurry where the particle size and shape is controlled together with the solution chemistry. We have investigated the effect of adsorbed cations on the stability of a suspension, the packing nature of a sediment and the frictional forces to be overcome during re-slurrying. A significant change in the criteria assessed was observed as the electrolyte concentration was increased from 0.1 mM to 1 M. In relation to industrial processes, such delicate control of the slurry chemistry can greatly influence the optimum operating conditions of non-Newtonian pipe flows. (authors)

Harbottle, David; Fairweather, Michael; Biggs, Simon [Institute of Particle Science and Engineering, School of Process, Environmental and Materials Engineering, University of Leeds, UK, LS2 9JT (United Kingdom); Rhodes, Dominic [Nexia Solutions, Sellafield, Cumbria (United Kingdom)

2007-07-01T23:59:59.000Z

300

Corrections for Measurements of Tritium in Subterranean Vapor using Silica Gel  

Science Conference Proceedings (OSTI)

Hazardous contaminants buried within vadose zones can accumulate in soil gas. The concentrations and spatial extent of these contaminants are measured to evaluate potential transport to ground water for public risk evaluation. Tritium is an important contaminant found in and monitored for in vadose zones across numerous sites within the United States nuclear weapons complex, including Los Alamos National Laboratory. The extraction, collection, and laboratory analysis of tritium from subterranean soil gas presents numerous technical challenges that have not been fully studied. Particularly, the lack of soil moisture in the soil gas in the vadose zone makes it difficult to obtain enough sample moisture (e.g., > 5 g) to provide for the required sensitivity, and often, only small amounts of moisture can be collected. Further, although silica gel has high affinity for water vapor and is prebaked prior to sampling, there is still sufficient residual moisture in the prebaked gel to dilute the relatively small amount of sampled moisture; thereby, significantly lowering the 'true' tritium concentration in the soil gas. This paper provides an evaluation of the magnitude of the bias from dilution, provides methods to correct past measurements by applying a correction factor (CF), and evaluates the uncertainty of the CF values. For this, ten-thousand Monte Carlo calculations were perfonned and distribution parameters of CF values were detennined and evaluated. The mean and standard deviation of the distribution of CF values were 1.53 {+-} 0.36, and the minimum, median, and maximum values were 1.14, 1.43, and 5.27, respectively.

Whicker, Jeffrey [Los Alamos National Laboratory; Dewart, Jean M [Los Alamos National Laboratory; Allen, Shannon P [Los Alamos National Laboratory; Eisele, William F [Los Alamos National Laboratory; Mcnaughton, Michael C [Los Alamos National Laboratory; Green, Andrew A [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
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301

Pore size effects on the sorption of supercritical carbon dioxide in mesoporous CPG-10 silica  

Science Conference Proceedings (OSTI)

Excess sorption isotherms of supercritical carbon dioxide in mesoporous CPG-10 silica glasses with nominal pore sizes of 75 (7.5 nm) and 350 (35 nm) were measured gravimetrically at 35 C and 50 C and pressures of 0-200 bar. Formation of broad maxima in the excess sorption was observed at fluid densities below the bulk critical density. Positive values of excess sorption were measured at bulk densities below about 0.65-0.7 g/cm3, whereas zero and negative values were obtained at higher densities, indicating that the interfacial fluid becomes less dense than the corresponding bulk fluid at high fluid densities. A shift of the excess sorption peak position to higher fluid density is found with increasing pore width. The excess sorption of CO2 normalized to the specific surface area is higher for the 35 nm pore size material, suggesting pore confinement effects. Conversely, the pore volume normalized excess sorption is higher for the 7.5 nm pore size material. Assessment of mean pore density reveals regions of constant pore fluid density, located between the excess sorption peak and the adsorption/depletion transition. Both materials exhibit such regions of constant mean pore fluid density as a function of bulk CO2 density at the lower temperature of 35 C, but not at 50 C. The results of this study suggest that the CO2 storage capacity in quartz-rich reservoirs is higher for sites with low temperature and rock textures characterized by narrow pores with high surface to volume ratios.

Rother, Gernot [ORNL; Krukowski, Elizabeth G [ORNL; Wallacher, Dirk [Helmholtz-Zentrum Berlin; Grimm, Nico [Helmholtz-Zentrum Berlin; Bodnar, Robert J [ORNL; Cole, David [Ohio State University

2012-01-01T23:59:59.000Z

302

Synthesis of Novel Polypeptide-Silica Hybrid Materials through Surface-Initiated N-carboxyanhydride Polymerization  

E-Print Network (OSTI)

There is an increasing demand for materials that are physically robust, easily recovered, and able to perform a wide variety of chemical functions. By combining hard and soft matter synergistically, organic-inorganic hybrid materials are potentially useful for a number of applications (e.g. catalysis, separations, sensing). In this respect, organic/ordered mesoporous silica (OMS) hybrids have attracted considerable attention, with an increasing emphasis on complex organic moieties achieved through multi-step reactions and polymerizations. It is on this front that we have focused our work, specifically in regard to polypeptides. Polypeptides are well suited organic components for hybrids as they provide a wide range of possible side chain chemistries (NH2, -SH, -COOH, -OH, etc.), chirality, and have conformations that are known to be responsive to external stimuli (pH, electrolytes, solvents, etc.). Our work has shown that N-carboxyanhydride chemistry offers a facile single step approach to the incorporation of dense polypeptide brushes in OMS. Modifying the initiator loading, pore size, pore topology, and monomer identity significantly impacted the properties of the obtained composites and peptide brush layers. Extending this work, a synthesis paradigm for preferentially grafting poly-L-lysine to the external and internal surfaces of SBA-15, a widely used OMS material, was developed. We observed that the pores of these hybrids could be opened and closed by the reversible swelling of the polypeptide layer. Similarly, novel bifunctional hybrids were synthesized by grafting polypeptides to the external surface of monodisperse OMS spheres that contain a thiol-functionalized core. The accessibility of the internal thiols to a fluorescent dye shows the potential of these hybrids for applications such as controlled uptake/release.

Lunn, Jonathan D.

2010-05-01T23:59:59.000Z

303

The Deep-Sea Natural Products, Biogenic Polyphosphate (Bio-PolyP) and Biogenic Silica (Bio-Silica), as Biomimetic Scaffolds for Bone Tissue Engineering: Fabrication of a Morphogenetically-Active Polymer  

E-Print Network (OSTI)

Abstract: Bone defects in human, caused by fractures/nonunions or trauma, gain increasing impact and have become a medical challenge in the present-day aging population. Frequently, those fractures require surgical intervention which ideally relies on autografts or suboptimally on allografts. Therefore, it is pressing and likewise challenging to develop bone substitution materials to heal bone defects. During the differentiation of osteoblasts from their mesenchymal progenitor/stem cells and of osteoclasts from their hemopoietic precursor cells, a lineage-specific release of growth factors and a trans-lineage homeostatic cross-talk via signaling molecules take place. Hence, the major hurdle is to fabricate a template that is functioning in a way mimicking the morphogenetic, inductive role(s) of the native extracellular matrix. In the last few years, two naturally occurring polymers that are produced by deep-sea sponges, the biogenic polyphosphate (bio-polyP) and biogenic silica (bio-silica) have also been identified as promoting morphogenetic on both osteoblasts andMar. Drugs 2013, 11 719

Xiaohong Wang; Heinz C. Schröder; Qingling Feng; Florian Draenert; Werner E. G. Müller

2013-01-01T23:59:59.000Z

304

Experimental and numerical study of the effective thermal conductivity of silica nanocomposites with thermal boundary resistance  

SciTech Connect

The thermal interface resistance at the macro scale is mainly described by the physical gap between two interfaces and constriction resistance due to this gap. The small gaps between the two material faces makes up the majority of thermal interface resistance at the macro scale. So, most of the studies have been focused on characterizing effect of surface geometry and material properties to thermal interface resistance. This resistance is more widely known as thermal contact resistance, represented with Rc. There are various models to predict thermal contact resistance at macro scale. These models predict thermal resistance Rc for given two materials by utilizing their bulk thermomechanical properties. Although, Rc represents thermal resistance accurately for macro size contacts between two metals, it is not suitable to describe interface resistance of particles in modern TIMs, aka particulate composites. The particles inside recently available TIMs are micron size and with effort to further increase surface area this particle size is approaching nano scale. At this small scale, Rc does not accurately predict thermal interface, as it is very difficult to characterize the surface topography. The thermal discontinuity at perfectly bonded interface of two dissimilar materials is termed as thermal boundary resistance (Rb) or Kapitza resistance. The macroscopic assumptions that thermal discontinuity only exists due to gaps and surface geometry leads to substantial error in determining interface thermal properties at micron and nano scale. The phenomenon of thermal boundary resistance is an inherent material property and arises due to fundamental mechanism of thermal transport. For metal-matrix particulate composites, Rb plays more important role than Rc. The free flowing nature of the polymer would eliminate most of the gaps between the two materials at their interface. This means almost all of the thermal resistance at particle/matrix interface would occur due to Rb. The current study presents experimental study of thermal boundary resistance for silica nano particles embedded inside epoxy resin. The bulk conductivity of the sample is measured and Rc is back calculated using Hasselman-Johnson s (H-J) equation. The numerical validation of the equation is also presented, including extrapolation study to predict effective conductivity of the nanocomposite TIM.

Kothari, Rushabh M [ORNL; Dinwiddie, Ralph Barton [ORNL; Wang, Hsin [ORNL

2013-01-01T23:59:59.000Z

305

The Effects of Using Alkali-Silica Reaction Affected Recycled Concrete Aggregate in Hot Mix Asphalt  

E-Print Network (OSTI)

The effects of using alkali-silica reaction (ASR) affected recycled concrete aggregate (ASR-RCA) in hot mix asphalt (HMA) were investigated in this study. Dilatometer and modified beam tests were performed to determine the possibility of new ASR occurring in reactive aggregates within the HMA or re-expansion of existing gel. The Lottman test and micro-calorimeter were used to determine the moisture susceptibility of HMA made with ASR-RCA. A differential scanning calorimeter (DSC) with thermogravimetric analysis (TGA) was used to evaluate the drying of an artificial gel and x-ray diffraction (XRD) was used to check for the potential presence of gel in the filler fraction of the ASR-RCAs. Micro-deval and freeze-thaw tests were evaluated for their potential to indicate the presence of excess micro-cracks or ASR gel. Expansion testing indicated that both ASR-RCAs were still reactive with 0.5 N NaOH solution saturated with calcium hydroxide (CH) at 60 degrees C. Dilatometer testing of HMA specimens in NaOH CH solution at 60 degrees C indicated a reaction between the asphalt binder and the solution, but little, if any, ASR. The lack of expansion in the modified beam test supports the binder-solution interaction. However, dilatometer testing in deicer solution at the same temperature indicated that some ASR may have occurred along with the primary binder-solution interaction. The volume change characteristics associated with the binder-solution interaction with and without ASR was supported by the change in pH and alkali concentration of the test solution. DSC/TGA testing indicated that the artificial gel dehydrated at approximately 100 degrees C. XRD analysis of the filler indicated that some gel may have accumulated in this fraction. Moisture damage testing indicated good resistance to moisture damage by HMA mixtures made with ASR-RCA especially compared to a virgin siliceous aggregate. Micro-deval and freeze-thaw tests can detect the presence of micro-cracks due to ASR in ASR-RCAs as higher mass loss than the virgin aggregate. The potential distress mechanisms that may occur when using ASR-RCA in an HMA pavement were identified. Results obtained using accelerated laboratory conditions were extrapolated based on anticipated field conditions. Guidelines for the mitigation of potential distresses in HMA made with ASR-RCA are presented.

Geiger, Brian James

2010-08-01T23:59:59.000Z

306

Structural Assessment of D-Regions Affected by Alkali-Silica Reaction/Delayed Ettringite Formation  

E-Print Network (OSTI)

A combined experimental and analytical program was conducted to investigate the effects of Alkali-Silica Reaction (ASR) and Delayed Ettringite Formation (DEF) on D-regions in reinforced concrete (RC) bridge bents. Four large-scale RC specimens, which represent cantilever and straddle bents in Texas bridges in each specimen, were constructed. The first specimen represented the unexposed control specimen, while the other three were conditioned in the field with supplemental watering to promote ASR/DEF and served as the exposed specimens. The control and two exposed specimens with various levels of ASR/DEF, after eight months and two years of field conditioning, were load tested to failure. The last specimen remains in field with additional exposure to promote ASR/DEF and will be load tested in future studies. The width and length of preload-induced cracks and developing cracks that initiated in the exposed specimens and grew over time, indicating concrete expansion due to ASR/DEF mechanisms, were measured. Petrographic analysis results of concrete cores extracted from the exposed specimens after their load testing confirmed the formation of ASR gel and minimum accumulation of ettringite. The structural testing results showed that the failure mechanism in all three tested specimens was due to a brittle shear failure in the beam-column joint. However, slightly greater stiffness, strength, and ductility were observed in the exposed specimens as a result of the activation of the reinforcing steel in the specimens due to the expansion of the concrete primarily from ASR, which effectively prestressed and confined the core concrete. Sectional analysis and Strut-and-Tie Modeling (STM) of the experimental specimens were applied. Three-dimensional nonlinear Finite Element Analyses (FEA) were also conducted to numerically simulate the overall structural performance, internal response, and out-of-plane behavior of the experimental specimens. The effects of varying constitutive relations of the concrete in tension on models of the specimens were compared with the measured experimental response. A method to mimic ASR/DEF effects on exposed specimens was proposed and incorporated into the FEA approach. As a result, forces that prestress and confine the core concrete were effectively applied through the reinforcing steel prior to subsequent structural loading. The three-dimensional FEA approach was able to simulate the out-of-plane behavior of the beam-column joint and the proposed method yielded comparable results with the measured overall and internal behavior of specimens.

Liu, Shih-Hsiang 1979-

2012-12-01T23:59:59.000Z

307

Compressive Creep Performance and High Temperature Dimensional Stability of Conventional Silica Refractories  

Science Conference Proceedings (OSTI)

Furnace designers and refractory engineers recognize that optimized furnace superstructure design and refractory selection are needed as glass production furnaces are continually striving toward greater output and efficiencies. Harsher operating conditions test refractories to the limit, while changing production technology (such as the conversion to oxy-fuel from traditional air-fuel firing) can alter the way the materials perform. Refractories for both oxy- and air-fuel fired furnace superstructures are subjected to high temperatures during service that may cause them to excessively creep or subside if the refractory material is not creep resistant, or if it is subjected to high stress, or both. Furnace designers can ensure that superstructure structural integrity is maintained if the creep behavior of the refractory material is well understood and well represented by appropriate engineering creep models. Several issues limit the abilities of furnace designers to (1) choose the optimum refractory for their applications, (2) optimize the engineering design, or (3) predict the service mechanical integrity of their furnace superstructures. Published engineering creep data are essentially non-existent for almost all commercially available refractories used for glass furnace superstructures. The limited data that do exist are supplied by the various refractory suppliers. Unfortunately, these suppliers generally have different ways of conducting their mechanical testing and they also interpret and report their data differently; this makes it hard for furnace designers to draw fair comparisons between competing grades of candidate refractories. Furthermore, the refractory supplier's data are often not available in a form that can be readily used for furnace design and for the prediction and design of long-term structural integrity of furnace superstructures. With the aim of providing such comparable data, the US DOE's Office of Industrial Technology and its Advanced Industrial Materials program is sponsoring work to conduct creep testing and analysis on refractories of interest to the glass industry. An earlier stage of the project involved identifying which refractories to test and this is described elsewhere. Conventional silica was one such identified refractory category, and the present report describes the creep behavior of this class of refractories. To portray a more complete understanding of how these refractories perform at service temperatures, their fundamental corrosion resistances, dimensional stabilities, and microstructure were characterized as well.

Karakus, M.; Kirkland, T.P.; Liu, K.C.; Moore, R.E.; Pint, B.A.; Wereszczak, A.A.

1999-03-01T23:59:59.000Z

308

Experimental study of the performance of a laminar flow silica gel desiccant packing suitable for solar air conditioning application  

DOE Green Energy (OSTI)

An experimental study of the performance of a low pressure drop silica gel desiccant packing has been carried out. The packing is in the form of narrow passages lined with a single layer of small silica gel particles. A near optimum particle size of 0.25 mm, and a range of passage widths of 1.46 to 3.75 mm were chosen based on the predictions of a computer simulation model. A test chamber was constructed with sufficient thermal insulation to allow close to adiabatic conditions for the 12 cm x 12 cm cross section of packing. Step change adsorption and desorption tests were performed for various plate spacings, air flow rates, air inlet conditions, and gel initial water contents. Air outlet moisture content and temperature, as well as pressure drop were measured. The experimental results were compared with predictions of the computer simulation model: This model is based on gas side controlled heat and mass transfer, with the small solid side mass transfer resistance incorporated in a crude manner, and heat transfer into the packing handled as a lumped thermal capacitance. Reasonable agreement was obtained between theoretical prediction and experiment. The match was found to improve with increased passage width. The discrepancies are chiefly attributed to an excessive air bypass, and to inaccurate accounting for heat transfer from the sides of the unit. Use of the computer code for prototype scale design purposes is recommended.

Biswas, P.

1983-02-01T23:59:59.000Z

309

Nanoporous Polytetrafluoroethylene/Silica Composite Separator as a High-Performance All-Vanadium Redox Flow Battery Membrane  

SciTech Connect

Driven by the motivation of searching for low-cost membrane alternatives, a novel nanoporous polytetrafluoroethylene/silica composite separator has been prepared and evaluated for its use in all-vanadium mixed-acid redox flow battery. This separator consisting of silica particles enmeshed in a polytetrafluoroethylene fibril matrix has no ion exchange capacity and is featured with unique nanoporous structures, which function as the ion transport channels in redox flow battery operation, with an average pore size of 38nm and a porosity of 48%. This separator has produced excellent electrochemical performance in the all-vanadium mixed-acid system with energy efficiency delivery comparable to Nafion membrane and superior rate capability and temperature tolerance. The separator also demonstrates an exceptional capacity retention capability over extended cycling, offering additional operational latitude towards conveniently mitigating the capacity decay that is inevitable for Nafion. Because of the inexpensive raw materials and simple preparation protocol, the separator is particularly low-cost, estimated to be at least an order of magnitude more inexpensive than Nafion. Plus the proven chemical stability due to the same backbone material as Nafion, this separator possesses a good combination of critical membrane requirements and shows great potential to promote market penetration of the all-vanadium redox flow battery by enabling significant reduction of capital and cycle costs.

Wei, Xiaoliang; Nie, Zimin; Luo, Qingtao; Li, Bin; Chen, Baowei; Simmons, Kevin L.; Sprenkle, Vincent L.; Wang, Wei

2013-09-02T23:59:59.000Z

310

Cathodoluminescence microscopy and petrographic image analysis of aggregates in concrete pavements affected by alkali-silica reaction  

SciTech Connect

Various microscopic techniques (cathodoluminescence, polarizing and electron microscopy) were combined with image analysis with the aim to determine a) the modal composition and degradation features within concrete, and b) the petrographic characteristics and the geological types (rocks, and their provenance) of the aggregates. Concrete samples were taken from five different portions of Highway Nos. D1, D11, and D5 (the Czech Republic). Coarse and fine aggregates were found to be primarily composed of volcanic, plutonic, metamorphic and sedimentary rocks, as well as of quartz and feldspar aggregates of variable origins. The alkali-silica reaction was observed to be the main degradation mechanism, based upon the presence of microcracks and alkali-silica gels in the concrete. Use of cathodoluminescence enabled the identification of the source materials of the quartz aggregates, based upon their CL characteristics (i.e., color, intensity, microfractures, deformation, and zoning), which is difficult to distinguish only employing polarizing and electron microscopy. - Highlights: Black-Right-Pointing-Pointer ASR in concrete pavements on the Highways Nos. D1, D5 and D11 (Czech Republic). Black-Right-Pointing-Pointer Cathodoluminescence was combined with various microscopic techniques and image analysis. Black-Right-Pointing-Pointer ASR was attributed to aggregates. Black-Right-Pointing-Pointer Source materials of aggregates were identified based on cathodoluminescence characteristics. Black-Right-Pointing-Pointer Quartz comes from different volcanic, plutonic and metamorphic parent rocks.

Stastna, A., E-mail: astastna@gmail.com [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2 (Czech Republic); Sachlova, S.; Pertold, Z.; Prikryl, R. [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2 (Czech Republic); Leichmann, J. [Department of Geological Sciences, Faculty of Science, Masaryk University in Brno, Kotlarska 267/2, 611 37 Brno (Czech Republic)

2012-03-15T23:59:59.000Z

311

Mesoporous Silica with Site-Isolated Amine and Phosphotungstic Acid Groups: A Solid Catalyst with Tunable Antagonistic Functions for One-Pot Tandem Reactions  

Science Conference Proceedings (OSTI)

A bifunctional solid catalyst is prepared by combining acid and base functions on mesoporous silica supports. The co-existence of these functions is shown by a two-step reaction sequence in one pot. Excellent product yields, which cannot be obtained by separated acid and base functions in one pot, show the validity of our concept.

Shiju N. R.; Syed K.; Alberts A.; Brown D. and Rothenberg G.

2011-09-15T23:59:59.000Z

312

Formation of mesoporous materials from silica dissolved in various NaOH concentrations: effect of pH and ionic strength  

Science Conference Proceedings (OSTI)

We describe the effects of NaOH/SiO2 ratio and pH on the formation of mesoporous materials, which was synthesized via an alkalimetal hydroxide fusion method, from amorphous silica dissolved in NaOH. Physical properties (e.g., specific surface ...

Jayhyun Park; Yosep Han; Hyunjung Kim

2012-01-01T23:59:59.000Z

313

Aerogels: stiff foams composed of up to 99.8% air Silica aerogel is the world's lowest-density solid: 1 mg/cm3  

E-Print Network (OSTI)

#12;Aerogels: stiff foams composed of up to 99.8% air Silica aerogel is the world's lowest-density solid: 1 mg/cm3 Aerogels hold 15 different records for material properties, including best insulator 2.38 g piece of aerogel supports a 2.5 kg brick. #12;#12;#12;l = m Ã? n unit vector in orbital space

Fominov, Yakov

314

The sorption of thorium, protacintium and plutonium onto silica particles in the presence of a colloidal third phase  

E-Print Network (OSTI)

The fate of actinides in the environment is of interest for a several reasons. In oceanic surface waters actinides such as thorium and protactinium, and in particular their ratio, are used as tracers of processes such as boundary scavenging and paleocirculation. Thorium is also used to estimate residence times and particle and colloid fluxes from the euphotic zone, which is useful in global carbon budgets used to assess effects of global warming. Terrestrially, contaminated areas in need of remediation, such as former nuclear weapons production facilities, remain as repositories for no longer needed actinide stockpiles or waste by-products such as plutonium. All three of these actinides: thorium, protactinium, and plutonium are known to be particle-reactive but the extent to which they sorb to immobile particles and mobile colloids can vary with environmental conditions. Understanding controls on adsorption is important in understanding uses and any limitations of these radioactive tracers caused by colloids. Often laboratory studies to understand actinide behavior are conducted at concentrations (micro- to millimolar), which are orders of magnitude higher than they are found in the environment (femto- to picomolar). Colloids, a size class of particles operationally defined as 1 nm to 1 µm in size, are ubiquitous in aquatic systems. The effect colloids have on actinide particle association, i.e. competitive or enhancing, can have a profound influence on the ultimate behavior of the actinide. The overall aim of this study is to assess sorption of thorium, protactinium and plutonium onto silica particles as a proxy for inorganic particles found in surface or ocean waters. In addition to the binary system of actinide/silica, the ternary system actinide/ organic colloid/ silica were also carried out to determine the affect of the organic colloid has on particle association. In particular, extracellular polymeric substances (EPS) extracted from laboratory grown bacteria and phytoplankton cultures were utilized as they too are ubiquitous in aquatic systems and have shown to strongly complex actinide ions, with EPS involved in oceanic scavenging of Th, as well as immobilization/mobilization of Pu in contaminated areas on land.

Roberts, Kimberly Ann

2008-05-01T23:59:59.000Z

315

Drug delivery from hydrophobic-modified mesoporous silicas: Control via modification level and site-selective modification  

SciTech Connect

Dimethylsilyl (DMS) modified mesoporous silicas were successfully prepared via co-condensation and post-grafting modification methods. The post-grafting modification was carried out by the reaction of the as-synthesized MCM-41 material (before CTAB removal) with diethoxydimethylsinale (DEDMS). N{sub 2} adsorption-desorption and {sup 29}Si MAS NMR characterization demonstrated that different amount of DMS groups were successfully incorporated into the co-condensation modified samples, and the functional DMS groups were placed selectively on the pore openings and external pore surfaces in the post-grafting modified samples. Subsequently, the controlled drug delivery properties from the resulting DMS-modified mesoporous silicas were investigated in detail. The drug adsorption experiments showed that the adsorption capacities were mainly depended on the content of silanol group (CSG) in the corresponding carriers. The in vitro tests exhibited that the incorporation of DMS groups greatly retarded the ibuprofen release rate. Moreover, the ibuprofen release profiles could be well modulated by varying DMS modification levels and site-selective distribution of functional groups in mesoporous carriers. - The distribution of DMS groups on the pore surfaces of the mesostructures strongly affects the drug release rate. The P-M41-1 and the P-M41-2 possess the close DMS modification levels as the C-M41-10, but the ibuprofen release rates from the P-M41-1 and P-M41-2 are much slower than that from the C-M41-10.

Tang Qunli, E-mail: tangqunli@hnu.c [College of Materials Science and Engineering, and Center for High-Resolution Electron Microscopy, Hunan University, Changsha 410082 (China); State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Chen Yuxi; Chen Jianghua; Li Jin [College of Materials Science and Engineering, and Center for High-Resolution Electron Microscopy, Hunan University, Changsha 410082 (China); Xu Yao; Wu Dong; Sun Yuhan [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

2010-01-15T23:59:59.000Z

316

Comparison of laser-based mitigation of fused silica surface damage using mid- versus far-infrared lasers  

SciTech Connect

Laser induced growth of optical damage can limit component lifetime and therefore operating costs of large-aperture fusion-class laser systems. While far-infrared (IR) lasers have been used previously to treat laser damage on fused silica optics and render it benign, little is known about the effectiveness of less-absorbing mid-IR lasers for this purpose. In this study, they quantitatively compare the effectiveness and efficiency of mid-IR (4.6 {micro}m) versus far-IR (10.6 {micro}m) lasers in mitigating damage growth on fused silica surfaces. The non-linear volumetric heating due to mid-IR laser absorption is analyzed by solving the heat equation numerically, taking into account the temperature-dependent absorption coefficient {alpha}(T) at {lambda} = 4.6 {micro}m, while far-IR laser heating is well-described by a linear analytic approximation to the laser-driven temperature rise. In both cases, the predicted results agree well with surface temperature measurements based on infrared radiometry, as well as sub-surface fictive temperature measurements based on confocal Raman microscopy. Damage mitigation efficiency is assessed using a figure of merit (FOM) relating the crack healing depth to laser power required, under minimally-ablative conditions. Based on their FOM, they show that for cracks up to at least 500 {micro}m in depth, mitigation with a 4.6 {micro}m mid-IR laser is more efficient than mitigation with a 10.6 {micro}m far-IR laser. This conclusion is corroborated by direct application of each laser system to the mitigation of pulsed laser-induced damage possessing fractures up to 225 {micro}m in depth.

Yang, S T; Matthews, M J; Elhadj, S; Cooke, D; Guss, G M; Draggoo, V G; Wegner, P J

2009-12-16T23:59:59.000Z

317

A density functional theory study of the oxidation of methanol to formaldehyde over vanadia supported on silica, titania, and zirconia  

DOE Green Energy (OSTI)

Density functional theory was used to investigate the mechanism and kinetics of methanol oxidation to formaldehyde over vanadia supported on silica, titania, and zirconia. The catalytically active site was modeled as an isolated VO{sub 4} unit attached to the support. The calculated geometry and vibrational frequencies of the active site are in good agreement with experimental measurements both for model compounds and oxide-supported vanadia. Methanol adsorption is found to occur preferentially with the rupture of a V-O-M bond (M = Si, Ti, Zr) and with preferential attachment of a methoxy group to V. The vibrational frequencies of the methoxy group are in good agreement with those observed experimentally as are the calculated isobars. The formation of formaldehyde is assumed to occur via the transfer of an H atom of a methoxy group to the O atom of the V=O group. The activation energy for this process is found to be in the range of 199-214 kJ/mol and apparent activation energies for the overall oxidation of methanol to formaldehyde are predicted to lie in the range of 112-123 kJ/mol, which is significantly higher than that found experimentally. Moreover, the predicted turnover frequency (TOF) for methanol oxidation is found to be essentially independent of support composition, whereas experiments show that the TOF is 10{sup 3} greater for titania- and zirconia-supported vanadia than for silica-supported vanadia. Based on these findings, it is proposed that the formation of formaldehyde from methoxy groups may require pairs of adjacent VO{sub 4} groups or V{sub 2}O{sub 7} dimer structures.

Khaliullin, Rustam Z.; Bell, Alexis T.

2002-09-05T23:59:59.000Z

318

Remaining Sites Verification Package for the 100-F-44:4, Discovery Pipeline in Silica Gel Pit, Waste Site Reclassification Form 2008-030  

SciTech Connect

The 100-F-44:4, Discovery Pipeline in Silica Gel Pit subsite is located in the 100-FR-1 Operable Unit of the Hanford Site, near the location of the former 110-F Gas Storage Tanks structure. The 100-F-44:4 subsite is a steel pipe discovered October 17, 2004, during trenching to locate the 118-F-4 Silica Gel Pit. Based on visual inspection and confirmatory investigation sampling data, the 100-F-44:4 subsite is a piece of non-hazardous electrical conduit debris. The 100-F-44:4 subsite supports unrestricted future use of shallow zone soil and is protective of groundwater and the Columbia River. No residual contamination exists within the deep zone. Therefore, no deep zone institutional controls are required.

J. M. Capron

2008-09-23T23:59:59.000Z

319

SERI Desiccant Cooling Test Facility. Status report. Preliminary data on the performance of a rotary parallel-passage silica-gel dehumidifier  

DOE Green Energy (OSTI)

This report describes the SERI Desiccant Cooling Test Facility. The facility can test bench-scale rotary dehumidifiers over a wide range of controlled conditions. We constructed and installed in the test loop a prototype parallel-passage rotary dehumidifier that has spirally wound polyester tape coated with silica gel. The initial tests gave satisfactory results indicating that approximately 90% of the silica gel was active and the overall Lewis number of the wheel was near unity. The facility has several minor difficulties including an inability to control humidity satisfactorily and nonuniform and highly turbulent inlet velocities. To completely validate the facility requires a range of dehumidifier designs. Several choices are available including constructing a second parallel-passage dehumidifier with the passage spacing more uniform.

Schultz, K.J.

1986-04-01T23:59:59.000Z

320

On-line tests of organic additives for the inhibition of the precipitation of silica from hypersaline geothermal brine IV. Final tests of candidate additives  

DOE Green Energy (OSTI)

The Lawrence Livermore Laboratory Brine Treatment Test System at Niland, Imperial Valley, California, has been used to evaluate a number of cationic polymers and surfactants as scale control agents. An initial group of compounds was narrowed to four on the basis of their activity as silica precipitation inhibitors. Three of these and certain combinations of compounds were then given a 40-h test to determine their effectiveness in retarding scales formed at 220, 125, and 90/sup 0/C. The best single compound was Corcat P-18 (Cordova Chemical Co. polyethylene imine, M.W. approx. = 1800). It had no effect on the scale at 220/sup 0/C, but it reduced the scales at 125 and 90/sup 0/C by factors of 4 and 18, respectively, and it also has activity as a corrosion inhibitor. Other promising compounds are PAE HCl (Dynapol poly(aminoethylene, HCl salt)), which also somewhat reduces the 220/sup 0/C scale; Ethoquad 18/25 (Armak methyl polyoxyethylene(15) octadecylammonium chloride); and Mirapol A-15 (a Miranol Chemical polydiquaternary compound). The best additive formulation for the brines of the Salton Sea Geothermal Field appears to be a mixture of one of these silica precipitation inhibitors with a small amount of hydrochloric acid and a phosphonate crystalline deposit inhibitor. Speculations are presented as to the mechanism of inhibition of silica precipitation and recommendations for further testing of these additives.

Harrar, J.E.; Locke, F.E.; Otto, C.H. Jr.; Lorensen, L.E.; Frey, W.P.; Snell, E.O.

1980-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Synthesis of Through-bond Energy Transfer Cassettes and Their Encapsulation in Silica and Calcium Phosphate Nanoparticles  

E-Print Network (OSTI)

Water-soluble fluorescent probes with emission in the 600-800 nm region have significant potential in biological applications such as cell imaging. Most fluorescent probes however suffer from limited fluorescence brightness in aqueous media due to aggregation and self-quenching. Their photostability in animal models for an extended period of time is also a concern. One way of improving their photophysical properties is to encapsulate them in a protective matrix to form fluorescent nanoparticles. We have synthesized a set of six through-bond energy transfer cassettes which emit in the 600-800 nm region with Fluorescein or BODIPY as donor and benzophenoxazine dye Nile Red or cyanine dye Cy5 as acceptor. Their photophysical properties in organic and aqueous media were evaluated. Some of these cassettes were encapsulated in silica or calcium phosphate nanoparticles (20 nm in diameter) to improve their solubility and photophysical properties in aqueous media. We also synthesized some water-soluble benzophenoxazine based fluorophores and the impact of different water-soluble groups on their emission characteristics in aqueous media was studied. Selected fluorophores were used for in vitro cellular imaging studies.

Jose, Jiney

2009-12-01T23:59:59.000Z

322

Trace element and REE composition of five samples of the Yucca Mountain calcite-silica deposits. Special report No. 8  

SciTech Connect

The attached materials document the results of part of a recent effort of geochemical sampling and analysis at Yucca Mountain and nearby regions. The efforts come as a result of interest in comprehensive analyses of rare earth elements (REE), lanthanum (La) through lutecium (Lu). Several additional, non-REE analyses were obtained as well. Commercially available REE analyses have proved to be insufficiently sensitive for geochemical purposes. Dr. Roman Schmitt at the Radiation Center at Oregon State University in Corvallis was sent five samples as a trial effort. The results are very encouraging. The purpose of compiling Dr. Schmitt`s report and the other materials is to inform the sponsor of his independent observations of these results and other information that sent to him. To provide a more complete appreciation of the utility of REE analyses a copy of Dave Vaniman`s recent article is included in which he notes that REE analyses from Yucca Mountain indicate the occurrence of two distinctly different REE patterns as do several other chemical parameters of the calcite-silica deposits. Our four samples with high equivalent CaCO{sub 3} were collected from sites we believe to be spring deposits. One sample, 24D, is from southern Crater Flat which is acknowledged by U.S.G.S. investigators to be a spring deposit. All four of these samples have REE patterns similar to those from the saturated zone reported by Vaniman.

Livingston, D.

1993-07-01T23:59:59.000Z

323

Visible Light Absorption of Binuclear TiOCoII Charge-Transfer UnitAssembled in Mesoporous Silica  

SciTech Connect

Grafting of CoII(NCCH3)2Cl2 onto mesoporous Ti-MCM-41 silicain acetonitrile solution affords binuclear Ti-O-CoII sites on the poresurface under complete replacement of the precursor ligands byinteractions with anchored Ti centers and the silica surface. The CoIIligand field spectrum signals that the Co centers are anchored on thepore surface in tetrahedral coordination. FT-infrared action spectroscopyusing ammonia gas adsorption reveals Co-O-Si bond modes at 831 and 762cm-1. No Co oxide clusters are observed in the as-synthesized material.The bimetallic moieties feature an absorption extending from the UV intothe visible to about 600 nm which is attributed to the TiIV-O-CoII?3TiIII-O-CoIII metal-to-metal charge-transfer (MMCT) transition. Thechromophore is absent in MCM-41 containing Ti and Co centers isolatedfrom each other; this material was synthesized by grafting CoII onto aTi-MCM-41 sample with the Ti centers protected by a cyclopentadienylligand. The result indicates that the appearance of the charge-transferabsorption requires that the metal centers are linked by an oxo bridge,which is additionally supported by XANES spectroscopy. The MMCTchromophore of Ti-O-CoII units has sufficient oxidation power to serve asvisible light electron pump for driving multi-electron transfer catalystsof demanding uphill reactions such as water oxidation.

Han, Hongxian; Frei, Heinz

2007-01-30T23:59:59.000Z

324

Laser damage by ns and sub-ps pulses on hafnia/silica anti-reflection coatings on fused silica double-sided polished using zirconia or ceria and washed with or without an alumina wash step.  

SciTech Connect

Sandia's Large Optics Coating Operation has extensive results of laser induced damage threshold (LIDT) testing of its anti-reflection (AR) and high reflection coatings on substrates pitch polished using ceria and washed in a process that includes an alumina wash step. The purpose of the alumina wash step is to remove residual polishing compound to minimize its role in laser damage. These LIDT tests are for multi longitudinal mode, ns class pulses at 1064 nm and 532 nm (NIF-MEL protocol) and mode locked, sub-ps class pulses at 1054 nm (Sandia measurements), and show reasonably high and adequate laser damage resistance for coatings in the beam trains of Sandia's Z-Backlighter terawatt and petawatt lasers. An AR coating in addition to coatings of our previous reports confirms this with LIDTs of 33.0 J/cm{sup 2} for 3.5 ns pulses and 1.8 J/cm{sup 2} for 350 fs pulses. In this paper, we investigate both ceria and zirconia in doublesided polishing (common for large flat Z-Backlighter laser optics) as they affect LIDTs of an AR coating on fused silica substrates washed with or without the alumina wash step. For these AR coated, double-sided polished surfaces, ceria polishing in general affords better resistance to laser damage than zirconia polishing and laser damage is less likely with the alumina wash step than without it. This is supported by specific results of laser damage tests with 3.5 ns, multi longitudinal mode, single shot pulses at 1064 nm and 532 nm, with 7.0 ns, single and multi longitudinal mode, single and multi shot pulses at 532 nm, and with 350 fs, mode-locked, single shot pulses at 1054 nm.

Bellum, John Curtis; Rambo, Patrick K.; Schwarz, Jens; Kletecka, Damon; Atherton, Briggs W.; Kimmel, Mark W.; Smith, Ian Craig; Smith, Douglas (Plymouth Grating Laboratory, Carver, MA); Hobbs, Zachary (Sydor Optics, Inc., Rochester, NY)

2010-10-01T23:59:59.000Z

325

Synthesis of Silica Supported AuCu Nanoparticle Catalysts and the Effects of Pretreatment Conditions for the CO Oxidation Reaction  

SciTech Connect

Supported gold nanoparticles have generated an immense interest in the field of catalysis due to their extremely high reactivity and selectivity. Recently, alloy nanoparticles of gold have received a lot of attention due to their enhanced catalytic properties. Here we report the synthesis of silica supported AuCu nanoparticles through the conversion of supported Au nanoparticles in a solution of Cu(C{sub 2}H{sub 3}O{sub 2}){sub 2} at 300 C. The AuCu alloy structure was confirmed through powder XRD (which indicated a weakly ordered alloy phase), XANES, and EXAFS. It was also shown that heating the AuCu/SiO{sub 2} in an O{sub 2} atmosphere segregated the catalyst into a Au-CuO{sub x} heterostructure between 150 C to 240 C. Heating the catalyst in H{sub 2} at 300 C reduced the CuO{sub x} back to Cu{sup 0} to reform the AuCu alloy phase. It was found that the AuCu/SiO{sub 2} catalysts were inactive for CO oxidation. However, various pretreatment conditions were required to form a highly active and stable Au-CuO{sub x}/SiO{sub 2} catalyst to achieve 100% CO conversion below room-temperature. This is explained by the in situ FTIR result, which shows that CO molecules can be chemisorbed and activated only on the Au-CuOx/SiO{sub 2} catalyst but not on the AuCu/SiO{sub 2} catalyst.

J Bauer; D Mullins; M Li; Z Wu; E Payzant; S Overbury; S Dai

2011-12-31T23:59:59.000Z

326

Mass fractal characteristics of silica sonogels as determined by small-angle x-ray scattering and nitrogen adsorption  

SciTech Connect

A sample series of silica sonogels was prepared using different water-tetraethoxysilane molar ratio (r{sub w}) in the gelation step of the process in order to obtain aerogels with different bulk densities after the supercritical drying. The samples were analyzed by means of small-angle x-ray-scattering (SAXS) and nitrogen-adsorption techniques. Wet sonogels exhibit mass fractal structure with fractal dimension D increasing from {approx}2.1 to {approx}2.4 and mass-fractal correlation length {xi} diminishing from {approx}13 nm to {approx}2 nm, as r{sub w} is changed in the nominal range from 66 to 6. The process of obtaining aerogels from sonogels and heat treatment at 500 deg. C, in general, increases the mass-fractal dimension D, diminishes the characteristic length {xi} of the fractal structure, and shortens the fractal range at the micropore side for the formation of a secondary structured particle, apparently evolved from the original wet structure at a high resolution level. The overall mass-fractal dimension D of aerogels was evaluated as {approx}2.4 and {approx}2.5, as determined from SAXS and from pore-size distribution by nitrogen adsorption, respectively. The fine structure of the 'secondary particle' developed in the obtaining of aerogels could be described as a surface-mass fractal, with the correlated surface and mass-fractal dimensions decreasing from {approx}2.4 to {approx}2.0 and from {approx}2.7 to {approx}2.5, respectively, as the aerogel bulk density increases from 0.25 (r{sub w}=66) up to 0.91 g/cm{sup 3} (r{sub w}=6)

Donatti, D.A.; Vollet, D.R.; Ibanez Ruiz, A.; Mesquita, A.; Silva, T.F.P. [Unesp-Universidade Estadual Paulista, IGCE, Departamento de Fisica, P.O. Box 178 CEP, 13500-970 Rio Claro, Sao Paulo (Brazil)

2005-01-01T23:59:59.000Z

327

Preliminary study of lead isotopes in the carbonate-silica veins of Trench 14, Yucca Mountain, Nevada  

Science Conference Proceedings (OSTI)

The sub-vertical carbonate-silica veins filling the Bow Ridge Fault, where exposed in Trench 14 on the east side of Yucca Mountain, carry a lead isotopic signature that can be explained in terms of local sources. Two isotopically distinguishable--silicate and carbonate--fractions of lead are recognized within the vein system as well as in overlying surficial calcrete deposits. The acid-insoluble silicate fraction is contributed largely from the decomposing Miocene volcanic tuff, which forms the wall rock of the fault zone and is a ubiquitous component of the overlying soil. Lead contained in the silicate fraction approaches in isotopic composition that of the Miocene volcanic rocks of Yucca Mountain, but diverges from it in some samples by being more enriched in uranogenic isotopes. The carbonate fraction of lead in both vein and calcrete samples resides dominantly in the HCl- and CH{sub 3}COOH-soluble calcite. HCl evidently also attacks and removes lead from silicate phases, but the milder CH{sub 3}COOH dissolution procedure oftentimes identifies a significantly more radiogenic lead in the calcite. Wind-blown particulate matter brought to the area from Paleozoic and Late Proterozoic limestones in surrounding mountains may be the ultimate source of the calcite. Isotopically more uniform samples suggest that locally the basaltic ash and other volcanic rock have contributed most of the lead to both fractions of the vein system. An important finding of this study is that the data does not require the more exotic mechanisms or origins that have been proposed for the veins. Instead, the remarkably similar lead isotopic properties of the veins to those of the soil calcretes support their interpretation as a surficial, pedogenic phenomenon.

Zartman, R.E.; Kwak, L.M.

1993-12-15T23:59:59.000Z

328

On-line tests of organic additives for the inhibition of the precipitation of silica from hypersaline geothermal brine II. Tests of nitrogen-containing compounds, silanes, and additional ethoxylated compounds  

DOE Green Energy (OSTI)

Several new classes of organic compounds have been screened as potential geothermal scale control agents by examining their effect on the precipitation of silica from Magmamax No. 1 brine. The substances were tested using the Lawrence Livermore Laboratory Brine Treatment Test System at the Niland, California, Test Site. Solutions of the test substances were injected into flowing brine at 210{sup 0}C, the brine was flashed to 125{sup 0}C, and then the kinetics of solids and silica precipitation from effluent brine held at 90{sup 0}C were measured. Three new types of compounds were shown to have activity as precipitation inhibitors: polyethylene imines, polyethyloxazalines, and quaternary ammonium compounds containing polyoxyethylene. Among the latter, Ethoquad 18/25, which is methyl-polyoxyethylene(15) octadecylammonium chloride, is the leading candidate antiscalant. It is a more powerful inhibitor of silica precipitation than the pure polyoxyethylene polymers, and it apparently has no high temperature solubility limitations. Measurements were made of the concentrations of monomeric silica and the effect of addition of inhibitor at various points in the Brine Treatment Test System. Five different silane compounds showed no activity toward silica.

Harrar, J.E.; Locke, F.E.; Otto, C.H. Jr.; Lorensen, L.E.; Frey, W.P.

1979-06-01T23:59:59.000Z

329

Nature of =~SiOCrO(2)CI And (=~SiO)(2)CrO(2) Sites Prepared By Grafting CrO(2)CI(2) Onto Silica  

SciTech Connect

The room-temperature reaction between chromyl chloride and Sylopol 952 silicas pretreated at 200, 450, and 800 C was investigated using IR, XANES, and EXAFS spectroscopy, as well as by DFT modeling. On the silicas pretreated at 200 and 450 C, the structurally uniform sites formed by the reaction with one surface hydroxyl group are described as {triple_bond}SiOCrO{sub 2}Cl. Unreacted silanols persist on these silicas even in the presence of excess CrO{sub 2}Cl{sub 2}, and on the silica pretreated at 200 C some participate in hydrogen bonding with the grafted monochlorochromate sites. On the silica pretreated at 800 C, both {triple_bond}SiOCrO{sub 2}Cl and ({triple_bond}SiO){sub 2}CrO{sub 2} sites are formed. The latter are produced despite the absence of hydrogen-bonded hydroxyl pairs on the support. The origin of the chromate sites is proposed to be the reaction between CrO{sub 2}Cl{sub 2} and hydroxyl-substituted siloxane 2-rings. These rings are likely formed at 800 C by condensation between a pair of vicinal silanols in which one of the silanols is also a member of a geminal pair.

Demmelmaier, C.A.; White, R.E.; Bokhoven, J.A.van; Scott, S.L.

2009-05-14T23:59:59.000Z

330

Optical characterization of n=1.03 silica aerogel used as radiator in the RICH of E. Aschenauer 9 , N. Bianchi 4 , G.P. Capitani 4 , P. Carter 3 , C Casalino 2 , E. Cisbani 6 , C. Coluzza 7 , R. De Leo 2;a ,  

E-Print Network (OSTI)

Optical characterization of n=1.03 silica aerogel used as radiator in the RICH of HERMES E Abstract The optical properties of silica aerogel tiles with a refractive index of 1.03 and dimensions 11, is completely interpretable as backscattering from inside the aerogel, revealing an absence of light reflection

331

Performance-based approach to evaluate alkali-silica reaction potential of aggregate and concrete using dilatometer method  

E-Print Network (OSTI)

The undesirable expansion of concrete because of a reaction between alkalis and certain type of reactive siliceous aggregates, known as alkali-silica reactivity (ASR), continues to be a major problem across the entire world. The renewed interest to minimize distress resulting from ASR has emphasized the need to develop predictable modeling of concrete ASR behavior under field conditions. Current test methods are either incapable or need long testing periods in which to only offer rather limited predictive estimates of ASR behavior in a narrow and impractical band of field conditions. Therefore, an attempt has been made to formulate a robust performance approach based upon basic properties of aggregate and concrete ASR materials derived from dilatometry and a kinetic-based mathematical expressions for ASR behavior. Because ASR is largely an alkali as well as a thermally activated process, the use of rate theory (an Arrhenius relationship between temperature and the alkali solution concentration) on the dilatometer time-expansion relationship, provides a fundamental aggregate ASR material property known as “activation energy.” Activation energy is an indicator of aggregate reactivity which is a function of alkalinity, particle size, crystallinity, calcium concentration, and others. The studied concrete ASR material properties represent a combined effects of mixture related properties (e.g., water-cementitious ratio, porosity, presence of supplementary cementitious materials, etc.) and maturity. Therefore, the proposed performance-based approach provides a direct accountability for a variety of factors that affect ASR, such as aggregate reactivity (activation energy), temperature, moisture, calcium concentration, solution alkalinity, and water-cementitious material ratio. Based on the experimental results, the following conclusion can be drawn concerning the performance-based approach to evaluate ASR potential of aggregate and concrete using dilatometer method; (i) the concept of activation energy can be used to represent the reactivity of aggregate subjected to ASR, (ii) the activation energy depends on the reactivity of aggregate and phenomenological alkalinity of test solution, and (iii) The proposed performance-based model provides a means to predict ASR expansion development in concrete.

Shon, Chang Seon

2008-05-01T23:59:59.000Z

332

Dynamics of Propane in Silica Mesopores Formed upon PropyleneHydrogenation over Pt Nanoparticles by Time-Resolved FT-IRSpectroscopy  

DOE Green Energy (OSTI)

Propylene hydrogenation over Pt nanoparticles supported onmesoporous silica type SBA-15 was monitored by time-resolved FT-IRspectroscopy at 23 ms resolution using short propylene gas pulses thatjoined a continuous flow of hydrogen in N2 (1 atm total pressure).Experiments were conducted in the temperature range 323-413 K. Propanewas formed within 100 milliseconds or faster. The CH stretching regionrevealed distinct bands for propane molecules emerging inside thenanoscale channels of the silica support. Spectral analysis gave thedistribution of the propane product between support and surrounding gasphase as function of time. Kinetic analysis showed that the escape ofpropane molecules from the channels occurred within hundreds ofmilliseconds (3.1 + 0.4 s-1 at 383 K). A steady state distribution ofpropane between gas phase and mesoporous support is established as theproduct is swept from the catalyst zone by the continuous flow ofhydrogen co-reactant. This is the first direct spectroscopic observationof emerging products of heterogeneous catalysis on nanoporous supportsunder reaction conditions.

Waslylenko, Walter; Frei, Heinz

2007-01-31T23:59:59.000Z

333

Quantifying Silica Reactivity in Subsurface Environments: Reaction Affinity and Solute Matrix Controls on Quartz and SiO2 Glass Dissolution Kinetics  

DOE Green Energy (OSTI)

During the three years of this project, Professor Dove's laboratory made tremendous progress in understanding controls on amorphous silica dissolution kinetics in aqueous solutions. Our findings have already received considerable attention. In hydrothermal and low temperature studies, the work focused on determining quantitative and mechanistic controls on the most abundant silica polymorphs in Earth environments--quartz and amorphous silica. Our studies achieved goals set forth in the original proposal to establish a new quantitative understanding of amorphous silica dissolution. This support has resulted in 10 journal, 12 abstracts and 2 thesis publications. The PI and students were also recognized with 6 awards during this period. The 1998 EMSP conference in Chicago was an important meeting for our project. The symposium, enabled P.I. Dove to establish valuable contacts with ''users'' having specific needs for the findings of our EMSP project related to the urgency of problems in the Tanks Focus Area (TFA). Since that time, our working relations developed as Dove interacted with TFA scientists and engineers on the problems of waste glass properties. These interactions refined our experimental objectives to better meet their needs. Dove presented the results of EMSP research findings to a TFA subgroup at a Product Acceptance Workshop held in Salt Lake City during December 1998. The travel costs to attend this unanticipated opportunity were paid from EMSP project funds. In January 2000, Dove also attended a similar meeting in Atlanta with PNNL, SRL and BNF scientists/engineers to discuss new issues and make another level of decisions on the Product Acceptance goals. Our EMSP-funded research interfaced very well with the ongoing studies of Dr. Pete McGrail and colleagues in the Applied Geochemistry Group at PNNL. The value of our work to ''users'' was further demonstrated when Dove's EMSP-funded Postdoc, Dr. Jonathan Icenhower was hired by the same PNNL group. With the Icenhower move from postdoc in the Dove lab to a senior scientist position at PNNL, we directly facilitated information transfer from the ''university to user'' environment. Icenhower brought experience in silica-water reactivity and the experimental expertise in high-quality methods of mineral-water reaction kinetics to the PNNL waste clean-up effort. In a further interaction, M.S. student Troy Lorier was hired at the Savannah River Laboratory for a staff position with the Bill Holtzcheiter glass group. His research meshed well with on-going efforts at SRL. In short, our EMSP project went well beyond the academic goals of producing high quality scientific knowledge to establish connections with on-site users to solve problems in TFA. This project also produced new talent for the waste immobilization effort. This EMSP project was highly successful and we thank our sponsors for the opportunity to advance scientific knowledge in this important area of research.

Patricia M. Dove

2000-12-13T23:59:59.000Z

334

Kinetics of Silica Polymerization  

E-Print Network (OSTI)

All toge tion and energy conversion system design strategiesthe overall energy extraction and conversion system must beenergy conversion process may be tailored to reduce or eliminate The benefits of a binary system

Weres, Oleh

2011-01-01T23:59:59.000Z

335

Preparation of silica aerogel using ionic liquids as solvents Sheng Dai,*a Y. H. Ju,ac H. J. Gao,b J. S. Lin,b S. J. Pennycookb and C. E. Barnesc  

E-Print Network (OSTI)

Preparation of silica aerogel using ionic liquids as solvents Sheng Dai,*a Y. H. Ju,ac H. J. Gaord December 1999 Ionic liquids have been used as effective solvents to synthesize aerogels; a long aging time can be used to produce stable aerogel structures without the need for supercritical drying

Gao, Hongjun

336

Numerical simulation study of silica and calcite dissolution around a geothermal well by injecting high pH solutions with chelating agent.  

SciTech Connect

Dissolution of silica, silicate, and calcite minerals in the presence of a chelating agent (NTA) at a high pH has been successfully performed in the laboratory using a high-temperature flow reactor. The mineral dissolution and porosity enhancement in the laboratory experiment has been reproduced by reactive transport simulation using TOUGHREACT. The chemical stimulation method has been applied by numerical modeling to a field geothermal injection well system, to investigate its effectiveness. Parameters from the quartz monzodiorite unit at the Enhanced Geothermal System (EGS) site at Desert Peak (Nevada) were used. Results indicate that the injection of a high pH chelating solution results in dissolution of both calcite and plagioclase minerals, and avoids precipitation of calcite at high temperature conditions. Consequently reservoir porosity and permeability can be enhanced especially near the injection well.

Xu, Tianfu; Rose, Peter; Fayer, Scott; Pruess, Karsten

2009-02-01T23:59:59.000Z

337

Mass spectrometric study of high-temperature dehydroxylation of disperse silicas and the interpretation of their IR spectra in the region of Si-O stretching vibrations  

SciTech Connect

Field-desorption mass spectrometry has been used to determine the lower boundary of the temperature interval for the removal of surface hydroxyl groups of aerosil. Both in the regime of cation desorption and in the regime of anion desorption, at temperatures above 900/sup 0/K, OH ions of the corresponding sign are registered. It is concluded that the thermal decomposition of the surface bonds triple bond Si-OH is homolytic in character. A mechanism is proposed for the dehydroxylation of SiO/sub 2/, according to which the initially formed radical centers triple bond Si and triple bond SiO change into ions: triple bond Si/sup +/ (I) and triple bond SiO/sup -/ (II). The bands at 888 and 908 cm/sup -1/ in the IR spectra of silicas obtained at high temperatures are assigned to vibrations of Si-O bonds in I and II, respectively.

Nazarenko, V.A.; Furman, V.I.; Guzikevich, A.G.; Gorlov, Yu.I.

1985-07-01T23:59:59.000Z

338

Time-resolved x-ray imaging of high-power laser-irradiated under-dense silica aerogels and agar foams  

SciTech Connect

This paper presents the results of experiments in which a high-power laser was used to irradiate low density (4 - 9 mg/cm{sup 3}) silica aerogel and agar foam targets. The laser-solid interaction and energy transport through the material were monitored with time-resolved imaging diagnostics, and the data show the production and propagation of an x-ray emission front in the plasma. The emission-front trajectory data are found to be in significant disagreement with detailed simulations, which predict a much more rapid heating of the cold material, and the data suggest that this discrepancy is not explainable by target inhomogeneities. Evidence suggests that energy transport into the cold material may be dominated by thermal conduction; however, no completely satisfactory explanation for the discrepancies is identified, and further experimental and theoretical research is necessary in order to resolve this important problem in laser-plasma interaction physics.

Koch, J.A.; Estabrook, K.G.; Bauer, J.D. [and others

1995-08-01T23:59:59.000Z

339

Mesoporous Silica Nanoparticles Loaded with Surfactant: Low Temperature Magic Angle Spinning 13C and 29Si NMR Enhanced by Dynamic Nuclear Polarization  

SciTech Connect

We show that dynamic nuclear polarization (DNP) can be used to enhance NMR signals of 13C and 29Si nuclei located in mesoporous organic/inorganic hybrid materials, at several hundreds of nanometers from stable radicals (TOTAPOL) trapped in the surrounding frozen disordered water. The approach is demonstrated using mesoporous silica nanoparticles (MSN), functionalized with 3-(N-phenylureido)propyl (PUP) groups, filled with the surfactant cetyltrimethylammonium bromide (CTAB). The DNP-enhanced proton magnetization is transported into the mesopores via 1H–1H spin diffusion and transferred to rare spins by cross-polarization, yielding signal enhancements ?on/off of around 8. When the CTAB molecules are extracted, so that the radicals can enter the mesopores, the enhancements increase to ?on/off ? 30 for both nuclei. A quantitative analysis of the signal enhancements in MSN with and without surfactant is based on a one-dimensional proton spin diffusion model. The effect of solvent deuteration is also investigated.

Lafon, Olivier [Universite de Lille Nord de France; Thankamony, Aany S. Lilly [Universite de Lille Nord de France; Kokayashi, Takeshi [Ames Laboratory; Carnevale, Diego [Ecole Polytechnique Federale de Lausanne; Vitzthum, Veronika [Ecole Polytechnique Federale de Lausanne; Slowing, Igor I. [Ames Laboratory; Kandel, Kapil [Ames Laboratory; Vezin, Herve [Universite de Lille Nord de France; Amoureux, Jean-Paul [Universite de Lille Nord de France; Bodenhausen, Geoffrey [Ecole Polytechnique Federale de Lausanne; Pruski, Marek [Ames Laboratory

2012-12-21T23:59:59.000Z

340

BACA Project: geothermal demonstration power plant. Final report  

DOE Green Energy (OSTI)

The various activities that have been conducted by Union in the Redondo Creek area while attempting to develop the resource for a 50 MW power plant are described. The results of the geologic work, drilling activities and reservoir studies are summarized. In addition, sections discussing the historical costs for Union's involvement with the project, production engineering (for anticipated surface equipment), and environmental work are included. Nineteen geothermal wells have been drilled in the Redondo Creek area of the Valles Caldera: a prominent geologic feature of the Jemez mountains consisting of Pliocene and Pleistocene age volcanics. The Redondo Creek area is within a complex longitudinal graben on the northwest flank of the resurgent structural dome of Redondo Peak and Redondo Border. The major graben faults, with associated fracturing, are geologically plausible candidates for permeable and productive zones in the reservoir. The distribution of such permeable zones is too erratic and the locations too imprecisely known to offer an attractive drilling target. Log analysis indicates there is a preferred mean fracture strike of N31W in the upper portion of Redondo Creek wells. This is approximately perpendicular to the major structure in the area, the northeast-striking Redondo Creek graben. The geothermal fluid found in the Redondo Creek reservoir is relatively benign with low brine concentrations and moderate H/sub 2/S concentrations. Geothermometer calculations indicate that the reservoir temperature generally lies between 500/sup 0/F and 600/sup 0/F, with near wellbore flashing occurring during the majority of the wells' production.

Not Available

1982-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Chemical and isotopic data for water from thermal springs and wells of Oregon  

DOE Green Energy (OSTI)

The thermal springs of Oregon range in composition from dilute NaHCO/sub 3/ waters to moderately saline CO/sub 2/-charged NaCl-NaHCO/sub 3/ waters. Most of the thermal springs are located in southeastern or southcentral Oregon, with a few in northeastern Oregon and near the contact of the Western Cascades with the High Cascades. Thermal springs in the central and northern parts of the Cascades generally issue moderately saline NaCl waters. Farther south in the Cascades, the thermal waters are high in CO/sub 2/ as well as chloride. Most thermal springs in northeastern Oregon issue dilute NaHCO/sub 3/ waters of high pH (>8.5). These waters are similar to the thermal waters which issue from the Idaho batholith, farther east. Most of the remaining thermal waters are Na mixed-anion waters. Based on the chemical geothermometers, Mickey Srpings, Hot Borax Lake, Alvord Hot Springs, Neal Hot Springs, Vale Hot Springs, Crump Well, Hunters (Lakeview) Hot Springs, and perhaps some of the springs in the Cascades are associated with the highest temperature systems (>150/sup 0/C).

Mariner, R.H.; Swanson, J.R.; Orris, G.J.; Presser, T.S.; Evans, W.C.

1981-01-01T23:59:59.000Z

342

Evaluation of low-temperature geothermal potential in north-central Box Elder County, Utah  

DOE Green Energy (OSTI)

The low-temperature geothermal resources of north-central Box Elder County, Utah were assessed. Exploration techniques used included chemical analyses of water from wells and springs, temperature surveys, and temperature-depth measurements in unused wells within the study area. The highest water temperatures (31/sup 0/, 30/sup 0/, and 29/sup 0/C) recorded in this research were located in three separate geographic regions, suggesting that no single warm water occurrence dominates the study area. Total dissolved solid (TDS) concentrations ranged from 294 to 11,590 mg/l. Areas of warm water occurrences generally had TDS values of greater than 1100 mg/l. Reservoir temperatures were estimated using chemical geothermometers. Calculated temperatures ranged between 50/sup 0/ and 100/sup 0/C. Temperature-depth measurements were logged in 16 unused wells. Thermal gradients calculated from the profiles ranged from isothermal to 267/sup 0/C/km. The background gradient for the study area appears to be slightly above the average Basin and Range gradient of 35/sup 0/C/km. The highest gradients were calculated for the area approximately eight kilometers west of Snowville, Utah, which is also an area of warm water. 61 refs., 15 figs., 6 tabs.

Davis, M.C.; Kolesar, P.T.

1984-12-01T23:59:59.000Z

343

Geothermal hydrology of Warner Valley, Oregon: a reconnaissance study  

DOE Green Energy (OSTI)

Warner Valley and its southern extension, Coleman Valley, are two of several high-desert valleys in the Basin and Range province of south-central Oregon that contain thermal waters. At least 20 thermal springs, defined as having temperatures of 20/sup 0/C or more, issue from Tertiary basaltic flows and tuffs in and near the valleys. Many shallow wells also produce thermal waters. The highest measured temperature is 127/sup 0/C, reported from a well known as Crump geyser, at a depth of 200 meters. The hottest spring, located near Crump geyser, has a surface temperature of 78/sup 0/C. The occurrence of these thermal waters is closely related to faults and fault intersections in the graben and horst structure of the valleys. Chemical analyses show that the thermal waters are of two types: sodium chloride and sodium bicarbonate waters. Chemical indicators show that the geothermal system is a hot-water rather than a vapor-dominated system. Conductive heat flow in areas of the valley unaffected by hydrothermal convection is probably about 75 milliwatts per square meter. The normal thermal gradient in valley-fill dpeosits in these areas may be about 40/sup 0/C per kilometer. Geothermometers and mixing models indicate that temperatures of equilibration are at least 170/sup 0/C for the thermal components of the hotter waters. The size and location of geothermal reservoirs are unknown.

Sammel, E.A.; Craig, R.W.

1981-01-01T23:59:59.000Z

344

Apacheta, a new geothermal prospect in Northern Chile  

DOE Green Energy (OSTI)

The discovery of two high-temperature fumaroles, with gas geochemistry compatible with an economic geothermal system, established Apacheta as one of the most attractive geothermal exploration prospects in northern Chile. These remote fumaroles at 5,150 m elevation were first sampled in 1999 by ENAP and its partners, following up on the reports of a CODELCO water exploration well that flowed small amounts of dry steam at 4,540 m elevation in the valley 4.5 km east of the fumaroles. The prospect is associated with a Plio-Pleistocene volcanic complex located within a NW-trending graben along the axis of the high Andes. The regional water table is 4,200 masl. There are no hot springs, just the 88 degrees C steam well and the 109 degrees and 118 degrees C fumaroles with gas compositions that indicate reservoir temperatures of greater than or equal to 250 degrees C, using a variety of gas geothermometers. An MT-TDEM survey was completed in 2001-2002 by Geotermica del Norte (SDN), an ENAP-C ODELCO partnership, to explore the Apacheta geothermal concession. The survey results indicated that base of the low resistivity clay cap has a structural apex just west of the fumaroles, a pattern typically associated with shallow permeability within a high temperature geothermal resource. SGN plans to drill at least one exploration well in 2002-03 to characterize a possible economic resource at Apacheta.

Urzua, Luis; Powell, Tom; Cumming, William B.; Dobson, Patrick

2002-05-24T23:59:59.000Z

345

Water information bulletin No. 30 geothermal investigations in Idaho  

DOE Green Energy (OSTI)

There are 899 thermal water occurrences known in Idaho, including 258 springs and 641 wells having temperatures ranging from 20 to 93/sup 0/C. Fifty-one cities or towns in Idaho containing 30% of the state's population are within 5 km of known geothermal springs or wells. These include several of Idaho's major cities such as Lewiston, Caldwell, Nampa, Boise, Twin Falls, Pocatello, and Idaho Falls. Fourteen sites appear to have subsurface temperatures of 140/sup 0/C or higher according to the several chemical geothermometers applied to thermal water discharges. These include Weiser, Big Creek, White Licks, Vulcan, Roystone, Bonneville, Crane Creek, Cove Creek, Indian Creek, and Deer Creek hot springs, and Raft River, Preston, and Magic Reservoir areas. These sites could be industrial sites, but several are in remote areas away from major transportation and, therefore, would probably be best utilized for electrical power generation using the binary cycle or Magma Max process. Present uses range from space heating to power generation. Six areas are known where commercial greenhouse operations are conducted for growing cut and potted flowers and vegetables. Space heating is substantial in only two places (Boise and Ketchum) although numerous individuals scattered throughout the state make use of thermal water for space heating and private swimming facilities. There are 22 operating resorts using thermal water and two commercial warm-water fish-rearing operations.

Mitchell, J.C.; Johnson, L.L.; Anderson, J.E.; Spencer, S.G.; Sullivan, J.F.

1980-06-01T23:59:59.000Z

346

Hydrogen and oxygen isotope geochemistry of cold and warm springs from the Tuscarora, Nevada thermal area  

DOE Green Energy (OSTI)

Eighteen cold and warm spring water samples from the Tuscarora, Nevada KGRA have been analyzed for hydrogen and oxygen isotope composition and fluid chemistry. Warm springs have deltaD values (-128 to -137 permil) significantly lower than those of cold springs to the north and east of the area, but similar to the deltaD values of cold springs to the west and south (-131 to -135 permil). The recharge area for the warm springs is unlikely to be to the immediate north, which is the local topographic highland in the area. The hydrogen isotope data would permit recharge from areas to the southwest or from high elevations to the southeast (Independence Mountains), a sector consistent with electrical resistivity evidence of fluid flow. Warm springs are HCO/sub 3//sup -/-rich waters, enriched by a factor of 3 to 10 in Na, HCO{sub 3}/{sup -} and SiO{sub 2} relative to local cold springs. Average quartz (no steam loss) and Na/K/Ca geothermometer estimates suggest subsurface temperatures of 145{sup 0} and 196{sup 0}C, respectively. The warm springs exhibit poor correlations between either hydrogen or oxygen isotope composition and water temperature or chemistry. The absence of such correlations suggests that there is no single coherent pattern of cold water mixing or evaporation in the thermal spring system.

Bowman, J.R.; Cole, D.

1982-06-01T23:59:59.000Z

347

Salt effects on isotope partitioning and their geochemical implications: An overview  

DOE Green Energy (OSTI)

Essential to the use of stable isotopes as natural tracers and geothermometers is the knowledge of equilibrium isotope partitioning between different phases and species, which is usually a function of temperature only. The one exception known to date is oxygen and hydrogen isotope fractionation between liquid water and other phases (steam, gases, minerals), which changes upon the addition of salts to water, i.e., the isotope salt salt effect. Our knowledge of this effect, the difference between activity and composition (a-X) of isotopic water molecules in salt solutions, is very limited and controversial, especially at elevated temperatures. For the last several years, we have been conducting a detailed, systematic experimental study at Oak Ridge National Laboratory to determine the isotope salt effects from room temperature to elevated temperatures (currently to 500{degree}C). From this effort, a simple, coherent picture of the isotope salt effect is emerging, that differs markedly from the complex results reported in the literature. In this communication, we present an overview on the isotope salt effect, obtained chiefly from our study. Observed isotope salt effects in salt solutions are significant even at elevated temperatures. The importance and implications of the isotope salt effect for isotopic studies of brine-dominated systems are also discussed in general terms.

Horita, J.; Cole, D.R.; Fortier, S.M. [and others

1996-01-01T23:59:59.000Z

348

Hydrogen and oxygen isotope geochemistry of cold and warm springs from the Tuscarora, Nevada Thermal Area  

DOE Green Energy (OSTI)

Eighteen cold and warm spring water samples from the Tuscarora, Nevada KGRA have been analyzed for hydrogen and oxygen isotope composition and fluid chemistry. Warm springs have deltaD values (128 to -137 permil) significantly lower than those of cold springs to the north and east of the area, but similar to the deltaD values of cold springs to the west and south (-131 to -135 permil). The recharge area for the warm springs is unlikely to be to the immediate north, which is the local topographic highland in the area. The hydrogen isotope data would permit recharge from areas to the southwest or from high elevations to the southeast (Independence Mountains), a sector consistent with electrical resistivity evidence of fluid flow. Warm springs are HCO/sub 3//sup -/-rich waters, enriched by a factor of 3 to 10 in Na, HCO/sub 3//sup -/ and SiO/sub 2/ relative to local cold springs. Average quartz (no steam loss) and Na/K/Ca geothermometer estimates suggest subsurface temperatures of 145/sup 0/ and 196/sup 0/C, respectively. The warm springs exhibit poor correlations between either hydrogen or oxygen isotope composition and water temperature or chemistry. The absence of such correlations suggests that there is no single coherent pattern of cold water mixing or evaporation in the thermal spring system.

Bowman, J.R.; Cole, D.

1982-10-01T23:59:59.000Z

349

Regional geothermal exploration in north central New Mexico. Final report  

DOE Green Energy (OSTI)

A broad-based geothermal resource reconnaissance study covering Bernalillo, Los Alamos, Rio Arriba, San Miguel, Sandoval, Santa Fe, Taos, Torrance, and Valencia counties in north central New Mexico was conducted from June 15, 1981, through September 30, 1983. Specific activities included the compilation of actual temperature, bottom-hole temperature gradient, and geotemperature data; tabulation of water chemistry data; field collection of temperature-depth data from existing wells; and drilling of temperature gradient holes in the Ojo Caliente, San Ysidro, Rio Puerco, and Polvadera areas. The data collected were used to perform: (1) a regional analysis of the geothermal energy potential of north central New Mexico; (2) two site-specific studies of the potential relationship between groundwater constrictions and geothermal resources; (3) an evaluation of the geothermal energy potential at Santa Ana Pueblo; (4) a general analysis of the geothermal energy resources of the Rio Grande Rift, including specific data on the Valles Caldera; and (5) an evaluation of the use of geothermometers on New Mexico groundwaters. Separate abstracts were prepared for individual chapters.

Icerman, L. (ed.) [ed.

1984-02-01T23:59:59.000Z

350

Reservoir simulation and geochemical study of Cerro Prieto I wells  

DOE Green Energy (OSTI)

Combined reservoir simulation and geochemical data analysis are used to investigate the effects of recharge and other reservoir processes occurring in the western part of the Cerro Prieto, Mexico, geothermal field (i.e., Cerro Prieto I area). Enthalpy-based temperatures and bottomhole temperatures are calculated based on simplified models of the system, considering different reservoir boundary conditions and zones of contrasting initial temperatures and reservoir properties. By matching the computed trends with geothermometer-based temperature and enthalpy histories of producing wells, the main processes active in the western area of Cerro Prieto are identified. This part of the geothermal system is strongly influenced by nearby groundwater aquifers; cooler waters readily recharge the reservoirs. In response to exploitation, the natural influx of cold water into the shallower alpha reservoir is mainly from the west and down Fault L, while the recharge to the deeper beta reservoir in this part of the field, seems to be only lateral, from the west and possibly south. 11 refs., 12 figs.

Lippmann, M.J. (Lawrence Berkeley Lab., CA (USA)); Truesdell, A.H. (Geological Survey, Menlo Park, CA (USA))

1990-03-01T23:59:59.000Z

351

Model of gypsum, calcite and silica solubilities for application to geothermal waters over a wide range of temperature, P/sub CO/sub 2// and ionic strength. Final technical report, October 1, 1983-September 30, 1984  

DOE Green Energy (OSTI)

This report describes the construction of a high temperature (25 to 250/sup 0/C), variable P/sub CO/sub 2// (1 to 40 atm), chemical model of mineral (including gypsum, calcite and amorphous silica) solubilities in the system: Na-K-Ca-H-Cl-SO/sub 4/-HCO/sub 3/-CO/sub 3/-CO/sub 2/-SiO/sub 2/-H/sub 2/O. This model was designed to support geothermal energy production needs.

Not Available

1984-01-01T23:59:59.000Z

352

Research and Development of a New Silica-Alumina Based Cementitious Material Largely Using Coal Refuse for Mine Backfill, Mine Sealing and Waste Disposal Stabilization  

SciTech Connect

Coal refuse and coal combustion byproducts as industrial solid waste stockpiles have become great threats to the environment. To activate coal refuse is one practical solution to recycle this huge amount of solid waste as substitute for Ordinary Portland Cement (OPC). The central goal of this project is to investigate and develop a new silica-alumina based cementitious material largely using coal refuse as a constituent that will be ideal for durable construction, mine backfill, mine sealing and waste disposal stabilization applications. This new material is an environment-friendly alternative to Ordinary Portland Cement. The main constituents of the new material are coal refuse and other coal wastes including coal sludge and coal combustion products (CCPs). Compared with conventional cement production, successful development of this new technology could potentially save energy and reduce greenhouse gas emissions, recycle vast amount of coal wastes, and significantly reduce production cost. A systematic research has been conducted to seek for an optimal solution for enhancing pozzolanic reactivity of the relatively inert solid waste-coal refuse in order to improve the utilization efficiency and economic benefit as a construction and building material.

Henghu Sun; Yuan Yao

2012-06-29T23:59:59.000Z

353

Methanol Decomposition over Palladium Particles Supported on Silica: Role of Particle Size and Co-Feeding Carbon Dioxide on the Catalytic Properties  

Science Conference Proceedings (OSTI)

Monodisperse palladium particles of six distinct and controlled sizes between 4-16 nm were synthesized in a one-pot polyol process by varying the molar ratios of the two palladium precursors used, which contained palladium in different oxidation states. This difference permitted size control by regulation of the nucleation rate because low oxidation state metals ions nucleate quickly relative to high oxidation state ions. After immobilization of the Pd particles on silica by mild sonication, the catalysts were characterized by X-ray absorption spectroscopy and applied toward catalytic methanol decomposition. This reaction was determined as structure sensitive with the intrinsic activity (turnover frequency) increasing with increasing particle size. Moreover, observed catalytic deactivation was linked to product (carbon monoxide) poisoning. Co-feeding carbon dioxide caused the activity and the amount of deactivation to decrease substantially. A reaction mechanism based on the formation of the {pi}-bond between carbon and oxygen as the rate-limiting step is in agreement with antipathetic structure sensitivity and product poisoning by carbon monoxide.

Hokenek, Selma; Kuhn, John N. (USF)

2012-10-23T23:59:59.000Z

354

A comparison study of carbon dioxide adsorption on polydimethylsiloxane, silica gel, and Illinois No. 6 coal using in situ infrared spectroscopy  

Science Conference Proceedings (OSTI)

Adsorption of supercritical carbon dioxide (CO{sub 2}) on polydimethylsiloxane (PDMS), silica gel (SiO{sub 2}), and Illinois No. 6 coal was compared using in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy at pressures up to 14 MPa and temperatures at 40{sup o}C and 50{sup o}C. Only physical adsorption of CO{sub 2} was recorded for PDMS, SiO{sub 2}, and Illinois no. 6. There was no evidence of the formation of carbonic acid, bicarbonates, carbonates, or any other reaction product between CO{sub 2} and PDMS, SiO{sub 2}, and Illinois No. 6 coal. Carbon dioxide adsorption on PDMS and SiO{sub 2} produced a linear isotherm while a typical Langmuir-like isotherm was observed for Illinois No. 6 coal. Attempts to measure CO{sub 2} induced swelling of the three materials was unsuccessful due to the design of the ATR-FTIR cell. 51 refs., 7 figs., 1 tab.

A.L. Goodman [U.S. Department of Energy, Pittsburgh, PA (USA). National Energy Technology Laboratory

2009-01-15T23:59:59.000Z

355

Synthesis of sulfated titania supported on mesoporous silica using direct impregnation and its application in esterification of acetic acid and n-butanol  

SciTech Connect

A new method has been developed for the preparation of sulfated titania (S-TiO{sub 2}) supported on mesoporous silica. The use of direct exchange of metal containing precursors for the surfactants in the as-synthesized MCM-41 substrate produced a product with high sulfur content without serious blockage of the pore structure of MCM-41. The pore sizes and volumes of the resultant S-TiO{sub 2}/MCM-41 composites were found to vary markedly with the loading of TiO{sub 2}. The strong acidic character of the composites obtained was examined by using them as catalysts for the esterification of acetic acid and n-butanol. - Abstract: XRD profiles of the composites of S-TiO{sub 2}/MCM-41 with different TiO{sub 2} contents. The low angle peaks indicate the MCM-41-like structure retained and a TiO{sub 2} phase appeared at high angle region. Display Omitted

Wang Yuhong, E-mail: yuhong_wang502@sit.edu.c [Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 200235 (China); Gan Yunting [Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 200235 (China); Whiting, Roger [School of Applied Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland (New Zealand); Lu Guanzhong [Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 200235 (China)

2009-09-15T23:59:59.000Z

356

Amorphisation mechanism of a flint aggregate during the alkali-silica reaction: X-ray diffraction and X-ray absorption XANES contributions  

Science Conference Proceedings (OSTI)

Flint samples at different stages of the Alkali-Silica Reaction were prepared and analyzed by X-ray diffraction (XRD) and silicon K-edge X-ray absorption near edge structure techniques (XANES). The results are compared to those of measurements performed on alpha quartz c-SiO{sub 2} and rough flint aggregate. The molar fraction of Q{sub 3} sites is determined as a function of the time of reaction. Up to 14 h of attack, the effect of the reaction seems of little importance. From 30 to 168 h, we showed an acceleration of the effect of the reaction on the crystal structure of the aggregate resulting in an amorphisation of the crystal. During this period, the amorphous fraction increases linearly with the number of Q{sub 3} sites. The results of the XANES confirm the amorphisation of the aggregate during the reaction and show the presence of silicon in a tetrahedral environment of oxygen whatever the time of attack.

Verstraete, J.; Khouchaf, L.; Bulteel, D.; Garcia-Diaz, E.; Flank, A.M; Tuilier, M.H

2004-04-01T23:59:59.000Z

357

Prediction and prevention of silica scaling at low levels of oversaturation: Case studies, and calculations for Uenotai Geothermal Field, Akita Prefecture, Japan  

DOE Green Energy (OSTI)

Production system design studies often include site-specific silica scaling field experiments, conducted because the onset and rate of scaling are believed difficult to predict, particularly at relatively low levels of oversaturation such as may exist in separators, flowlines, and injection wells. However, observed scaling occurrences (Cerro Prieto, Dixie Valley, Svartsengi, Otake, Hatchobaru, Milos, experimental work) actually conform fairly well to existing theory and rate equations. It should be possible to predict low level scaling with sufficient confidence for production and injection system design and, in cases where oversaturation is allowed, to design systems with foresight to suppress or manage the scale which develops. A promising suppression technology is fluid pH reduction by mixing with non-condensible gases and/or condensate. Calculations for injection lines at Uenotai geothermal field indicate molecular deposition at rates of 0.1 to 1 mm/yr, and some potential for particle deposition at points of turbulence, which can be suppressed by an order of magnitude with about 500 ppm CO{sub 2}. Further improvements of predictive technique will benefit from more uniformity in designing experiments, reporting results, and reporting measurements of scaling in actual production systems.

Klein, Christopher W.; Iwata, Shun; Takeuchi, Rituo; Naka, Tohsaku

1991-01-01T23:59:59.000Z

358

Mixed-Matric Membranes for CO2 and H2 Gas Separations Using Metal-Organic Framework and Mesoporus Hybrid Silicas  

Science Conference Proceedings (OSTI)

In this work, we have investigated the separation performance of polymer-based mixed-matrix membranes containing metal-organic frameworks and mesoporous hybrid silicas. The MOF/Matrimid{reg_sign} and MOP-18/Matrimid{reg_sign} membranes exhibited improved dispersion and mechanical strength that allowed high additive loadings with reduced aggregation, as is the case of the 80 wt% MOP-18/Matrimid{reg_sign} and the 80% (w/w) Cu-MOF/Matrimid{reg_sign} membranes. Membranes with up to 60% (w/w) ZIF-8 content exhibited similar mechanical strength and improved dispersion. The H{sub 2}/CO{sub 2} separation properties of MOF/Matrimid{reg_sign} mixed-matrix membranes was improved by either keeping the selectivity constant and increasing the permeability (MOF-5, Cu-MOF) or by improving both selectivity and permeability (ZIF-8). In the case of MOF-5/Matrimid{reg_sign} mixed-matrix membranes, the H{sub 2}/CO{sub 2} selectivity was kept at 2.6 and the H{sub 2} permeability increased from 24.4 to 53.8 Barrers. For the Cu-MOF/Matrimid{reg_sign} mixed-matrix membranes, the H{sub 2}/CO{sub 2} selectivity was kept at 2.05 and the H{sub 2} permeability increased from 17.1 to 158 Barrers. These two materials introduced porosity and uniform paths that enhanced the gas transport in the membranes. When ZIF-8/Matrimid{reg_sign} mixed-matrix membranes were studied, the H{sub 2}/CO{sub 2} selectivity increased from 2.9 to 4.4 and the permeability of H{sub 2} increased from 26.5 to 35.8 Barrers. The increased H{sub 2}/CO{sub 2} selectivity in ZIF-8/Matrimid{reg_sign} membranes was explained by the sieving effect introduced by the ZIF-8 crystals (pore window 0.34 nm) that restricted the transport of molecules larger than H{sub 2}. Materials with microporous and/or mesoporous cavities like carbon aerogel composites with zeolite A and zeolite Y, and membranes containing mesoporous ZSM-5 showed sieving effects for small molecules (e.g. H{sub 2} and CO{sub 2}), however, the membranes were most selective for CO{sub 2} due to the strong interaction of the zeolites with CO{sub 2}. For example, at 30 wt% ZSM-5 loading, the CO{sub 2}/CH{sub 4} selectivity increased from 34.7 (Matrimid{reg_sign}) to 56.4. The large increase in selectivity was the result of the increase in CO{sub 2} permeability from 7.3 (Matrimid{reg_sign}) to 14.6 Barrers. At 30 wt% ZSM-5 loading, the H{sub 2}/CH{sub 4} separation was also improved from 83.3 (Matrimid{reg_sign}) to 136.7 with an increase in H{sub 2} permeability from 17.5 (Matrimid{reg_sign}) to 35.3 Barrers. The 10% carbon aerogel-zeolite A and -zeolite Y composite/Matrimid{reg_sign} membranes exhibited an increase in the CO{sub 2}/CH{sub 4} separation from 34.7 to 71.5 (zeolite A composite) and to 57.4 (zeolite Y composite); in addition, the membrane exhibited an increase in the CO{sub 2}/N{sub 2} separation from 33.1 to 50 (zeolite A composite) and to 49.4 (zeolite Y composite), indicating that these type of materials have affinity for CO{sub 2}. The inclusion of mesoporosity enhanced the dispersion of the additive allowing loadings of up to 30% (w/w) without the formation of non-selective voids.

Inga Musselman; Kenneth Balkus, Jr.; John Ferraris

2009-01-07T23:59:59.000Z

359

BACA Project: geothermal demonstration power plant. Final report  

SciTech Connect

The various activities that have been conducted by Union in the Redondo Creek area while attempting to develop the resource for a 50 MW power plant are described. The results of the geologic work, drilling activities and reservoir studies are summarized. In addition, sections discussing the historical costs for Union's involvement with the project, production engineering (for anticipated surface equipment), and environmental work are included. Nineteen geothermal wells have been drilled in the Redondo Creek area of the Valles Caldera: a prominent geologic feature of the Jemez mountains consisting of Pliocene and Pleistocene age volcanics. The Redondo Creek area is within a complex longitudinal graben on the northwest flank of the resurgent structural dome of Redondo Peak and Redondo Border. The major graben faults, with associated fracturing, are geologically plausible candidates for permeable and productive zones in the reservoir. The distribution of such permeable zones is too erratic and the locations too imprecisely known to offer an attractive drilling target. Log analysis indicates there is a preferred mean fracture strike of N31W in the upper portion of Redondo Creek wells. This is approximately perpendicular to the major structure in the area, the northeast-striking Redondo Creek graben. The geothermal fluid found in the Redondo Creek reservoir is relatively benign with low brine concentrations and moderate H/sub 2/S concentrations. Geothermometer calculations indicate that the reservoir temperature generally lies between 500/sup 0/F and 600/sup 0/F, with near wellbore flashing occurring during the majority of the wells' production.

1982-12-01T23:59:59.000Z

360

Session 10: The Cerro Prieto Geothermal Field, Mexico: The Experiences Gained from Its Exploration and Development  

DOE Green Energy (OSTI)

The Cerro Prieto case study demonstrated the value of a multidisciplinary effort for exploring and developing a geothermal field. There was no problem in recognizing the geothermal potential of the Cerro Prieto area because of the many obvious surface manifestations. However, the delineation of the geothermal reservoir at depth was not so straightforward. Wells drilled near the abundant surface manifestations only produced fluids of relatively low enthalpy. Later it was determined that these zones of high heat loss corresponded to discharge areas where faults and fractures allowed thermal fluids to leak to the surface, and not to the main geothermal reservoir. The early gravity and seismic refraction surveys provided important information on the general structure of the area. Unaware of the existence of a higher density zone of hydrothermally altered sediments capping the geothermal reservoir, CFE interpreted a basement horst in the western part of the field and hypothesized that the bounding faults were controlling the upward flow of thermal fluids. Attempting to penetrate the sedimentary column to reach the ''basement horst'', CFE discovered the {alpha} geothermal reservoir (in well M-5). The continuation of the geothermal aquifer (actually the {beta} reservoir) east of the original well field was later confirmed by a deep exploration well (M-53). The experience of Cerro Prieto showed the importance of chemical ratios, and geothermometers in general, in establishing the subsurface temperatures and fluid flow patterns. Fluid chemical and isotopic compositions have also been helpful to determine the origin of the fluids, fluid-production mechanisms and production induced effects on the reservoir.

Lippman, M.J.; Goldstein, N.E.; Halfman, S.E.; Witherspoon, P.A.

1983-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Geothermal pilot study final report: creating an international geothermal energy community  

DOE Green Energy (OSTI)

The Geothermal Pilot Study under the auspices of the Committee on the Challenges of Modern Society (CCMS) was established in 1973 to apply an action-oriented approach to international geothermal research and development, taking advantage of the established channels of governmental communication provided by the North Atlantic Treaty Organization (NATO). The Pilot Study was composed of five substudies. They included: computer-based information systems; direct application of geothermal energy; reservoir assessment; small geothermal power plants; and hot dry rock concepts. The most significant overall result of the CCMS Geothermal Pilot Study, which is now complete, is the establishment of an identifiable community of geothermal experts in a dozen or more countries active in development programs. Specific accomplishments include the creation of an international computer file of technical information on geothermal wells and fields, the development of studies and reports on direct applications, geothermal fluid injection and small power plants, and the operation of the visiting scientist program. In the United States, the computer file has aready proven useful in the development of reservoir models and of chemical geothermometers. The state-of-the-art report on direct uses of geothermal energy is proving to be a valuable resource document for laypersons and experts in an area of increasing interest to many countries. Geothermal fluid injection studies in El Salvador, New Zealand, and the United States have been assisted by the Reservoir Assessment Substudy and have led to long-range reservoir engineering studies in Mexico. At least seven small geothermal power plants are in use or have been planned for construction around the world since the Small Power Plant Substudy was instituted--at least partial credit for this increased application can be assigned to the CCMS Geothermal Pilot Study. (JGB)

Bresee, J.C.; Yen, W.W.S.; Metzler, J.E. (eds.)

1978-06-01T23:59:59.000Z

362

Role of the nature of the support (alumina or silica), of the support porosity, and of the Pt dispersion in the selective reduction of NO by C{sub 3}H{sub 6} under lean-burn conditions  

SciTech Connect

During selective reduction of NO{sub x} under lean-burn conditions, a Pt particle size dependency has previously been observed with various supports. In this study, the authors have examined the influence of various parameters over a large range of initial metal dispersion: nature of the support (silica or alumina), support porosity, presence of impurities (particularly chlorine or sulfur), nature of the platinum precursor salt, and Pt particle size distribution. Furthermore, the authors have considered the mean particle size after sintering under the reactant mixture up to 773 K. Of the factors considered, only the Pt dispersion is of key importance. The intrinsic activity increases with decreasing dispersion (measured initially or after reaction) for each of the main reactions: reduction of NO into N{sub 2} or N{sub 2}O, oxidation of NO into NO{sub 2}, or oxidation of C{sub 3}H{sub 6} into CO{sub 2}. The dispersion does not clearly affect the selectivity.

Denton, P.; Giroir-Fendler, A.; Praliaud, H.; Primet, M.

2000-01-25T23:59:59.000Z

363

Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at Trenches 14 and 14D on the Bow Ridge Fault at Exile Hill, Nye County, Nevada  

SciTech Connect

Yucca Mountain, a proposed site for a high-level nuclear-waste repository, is located in southern Nevada, 20 km east of Beatty, and adjacent to the southwest comer of the Nevada Test Site (NTS) (fig. 1). Yucca Mountain is located within the Basin and Range province of the western United States. The climate is semiarid, and the flora is transitional between that of the Mojave Desert to the south and the Great Basin Desert to the north. As part of the evaluation, hydrologic conditions, especially water levels, of Yucca Mountain and vicinity during the Quaternary, and especially the past 20,000 years, are being characterized. In 1982, the US Geological Survey, in cooperation with the US Department of Energy (under interagency agreement DE-A104-78ET44802), excavated twenty-six bulldozer and backhoe trenches in the Yucca Mountain region to evaluate the nature and frequency of Quaternary faulting (Swadley and others, 1984). The trenches were oriented perpendicular to traces of suspected Quaternary faults and across projections of known bedrock faults into Quaternary deposits. Trench 14 exposes the Bow Ridge Fault on the west side of Exile Hill. Although the original purpose of the excavation of trench 14 was to evaluate the nature and frequency of Quaternary faulting on the Bow Ridge Fault, concern arose as to whether or not the nearly vertical calcium carbonate (the term ``carbonate`` in this study refers to calcium carbonate) and opaline silica veins in the fault zone were deposited by ascending waters (ground water). These veins resemble in gross morphology veins commonly formed by hydrothermal processes.

Taylor, E.M.; Huckins, H.E.

1995-02-01T23:59:59.000Z

364

Lithiation of Silica through Partial Reduction  

DOE Green Energy (OSTI)

We demonstrate the reversible lithiation of SiO{sub 2} up to 2/3 Li per Si, and propose a mechanism for it based on molecular dynamics and density functional theory simulations. Our calculations show that neither interstitial Li (no reduction), nor the formation of Li{sub 2}O clusters and Si-Si bonds (full reduction) are energetically favorable. Rather, two Li effectively break a Si-O bond and become stabilized by oxygen, thus partially reducing the SiO{sub 2} anode: this leads to increased anode capacity when the reduction occurs at the Si/SiO{sub 2} interface. The resulting Li{sub x}SiO{sub 2} (x < 2/3) compounds have band-gaps in the range of 2.0-3.4 eV.

Ban, C.; Kappes, B. B.; Xu, Q.; Engtrakul, C.; Ciobanu, C. V.; Dillon, A. C.; Zhao, Y.

2012-06-11T23:59:59.000Z

365

Understanding Silica-Kaolinite Composite Sintering  

Science Conference Proceedings (OSTI)

Field Assisted Sintering of Oxide Ceramics: New Mechanisms · High-Speed Compaction of Powder Materials at High Voltage Electric Discharge Consolidation.

366

Silicon Nitride Nanowire Papers Synthesized by Silica ...  

Science Conference Proceedings (OSTI)

Aerosol Jet® Material Deposition for High Resolution Printed Electronic Applications ... Carbon Nanotube Coatings Laser Power and Energy Measurements ... Rational Tailoring of 1-D (Nanowires), 2-D (Graphene) and 3-D (Ceramic/Carbon ...

367

Deformation of Silica Aerogel During Fluid Adsorption  

E-Print Network (OSTI)

Aerogels are very compliant materials - even small stresses can lead to large deformations. In this paper we present measurements of the linear deformation of high porosity aerogels during adsorption of low surface tension fluids, performed using a Linear Variable Differential Transformer (LVDT). We show that the degree of deformation of the aerogel during capillary condensation scales with the surface tension, and extract the bulk modulus of the gel from the data. Furthermore we suggest limits on safe temperatures for filling and emptying low density aerogels with helium.

Tobias Herman; James Day; John Beamish

2005-06-30T23:59:59.000Z

368

Manufacturing complex silica aerogel target components  

SciTech Connect

Aerogel is a material used in numerous components in High Energy Density Physics targets. In the past these components were molded into the proper shapes. Artifacts left in the parts from the molding process, such as contour irregularities from shrinkage and density gradients caused by the skin, have caused LANL to pursue machining as a way to make the components.

Defriend Obrey, Kimberly Ann [Los Alamos National Laboratory; Day, Robert D [Los Alamos National Laboratory; Espinoza, Brent F [Los Alamos National Laboratory; Hatch, Doug [Los Alamos National Laboratory; Patterson, Brian M [Los Alamos National Laboratory; Feng, Shihai [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

369

Physiochemical Properties of Cryolite-Silica Melts  

Science Conference Proceedings (OSTI)

It is thus essential to develop a method for synthesis of solar silicon which is ... Case Study of the Development of a Light Weighted Refuse Collection Unit.

370

LIGHT SCATTERING STUDIES OF SILICA AEROGELS  

E-Print Network (OSTI)

van de Hulst, H.C. , Light Scattering by Small Particles,A New Polarization-Modulated Light Scattering Instrument,"and interpretation of light scattering effects in aerogels.

Hunt, A.J.

2010-01-01T23:59:59.000Z

371

Functional Composites: Fluorescent Carbon Nanotubes in Silica ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2012. Symposium, Functional and Innovative Composites. Presentation Title, Functional ...

372

Electrophoretic Deposition of Silica on Stainless Steel  

Science Conference Proceedings (OSTI)

Long-Term Surface Restoration Effect Introduced by Advanced Lubricant Additive · Nanocomposite Thermal Spray Coatings. New Hardfacing Overlay Claddings ...

373

Biomimetic oxidation studies. 11: Alkane functionalization in aqueous solution utilizing in situ formed [Fe{sub 2}O({eta}{sup 1}-H{sub 2}O)({eta}{sup 1}-OAc)(TPA){sub 2}]{sup 3+}, as an MMO model precatalyst, embedded in surface-derivatized silica and contained in micelles  

Science Conference Proceedings (OSTI)

The biomimetic, methane monooxygenase enzyme (MMO) precatalyst, [Fe{sub 2}O({eta}{sup 1}-H{sub 2}O)({eta}{sup 1}-OAc)(TPA){sub 2}]{sup 3+} (TPA = tris[(2-pyridyl)methyl]amine), 1, formed in situ at pH 4.2 from [Fe{sub 2}O({mu}-OAc)(TPA){sub 2}]{sup 3+}, 2, was embedded in an amorphous silicate surface modified by a combination of hydrophilic poly(ethylene oxide) and hydrophobic poly(propylene oxide). The resulting catalytic assembly was found to be a biomimetic model for the MMO active site within a hydrophobic macroenvironment, allowing alkane functionalization with tert-butyl hydroperoxide (TBHP)/O{sub 2} in an aqueous reaction medium (pH 4.2). For example, cyclohexane was oxidized to a mixture of cyclohexanone, cyclohexanol, and cyclohexyl-tert-butyl peroxide, in a ratio of {approximately}3:1:2. The balance between poly(ethylene oxide) and poly(propylene oxide), tethered on the silica surface, was crucial for maximizing the catalytic activity. The silica-based catalytic assembly showed reactivity somewhat higher in comparison to an aqueous micelle system utilizing the surfactant, cetyltrimethylammonium hydrogen sulfate at its critical micelle concentration, in which functionalization of cyclohexane with TBHP/O{sub 2} in the presence of 1 was also studied at pH 4.2 and was found to provide similar products: cyclohexanol, cyclohexanone, and cyclohexyl-tert-butyl peroxide, in a ratio of {approximately}2:3:1. Moreover, the mechanism for both the silica-based catalytic assembly and the aqueous micelle system was found to occur via the Haber-Weiss process, in which redox chemistry between 1 and TBHP provides both the t-BuO{sup {sm_bullet}} and t-BuOO{sup {sm_bullet}} radicals. The t-BuO{sup {sm_bullet}} radical initiates the C-H functionalization reaction to form the carbon radical, followed by O{sub 2} trapping, to provide cyclohexyl hydroperoxide, which produces the cyclohexanol and cyclohexanone in the presence of 1, whereas the coupling product emanates from t-BuOO{sup {sm_bullet}} and cyclohexyl radicals. A discussion concerning both approaches for alkane functionalization in water will be presented.

Neimann, K.; Neumann, R. [Hebrew Univ., Jerusalem (Israel); Rabion, A. [Lawrence Berkeley National Lab., CA (United States)]|[Groupement de Recherche de Lacq, Artix (France); Buchanan, R.M. [Univ. of Louisville, KY (United States). Dept. of Chemistry; Fish, R.H. [Lawrence Berkeley National Lab., CA (United States)

1999-07-26T23:59:59.000Z

374

Deep NLD Plasma Etching of Fused Silica and Borosilicate Glass  

E-Print Network (OSTI)

, 92697 Email: mahamed@uci.edu Abstract-- In this paper, we report development of deep plasma etching

Tang, William C

375

Tritium Removal from Tritiated Water Using Mesoporous Silica  

Science Conference Proceedings (OSTI)

Detritiation and Isotope Separation / Proceedings of the Ninth International Conference on Tritium Science and Technology (Part 2)

A. Taguchi; R. Akai; M. Saito; Y. Torikai; M. Matsuyama; M. Ogura; S. Uchida

376

Size-dependent Elasticity of Amorphous Silica Nanowire  

Science Conference Proceedings (OSTI)

Ion Exchanged Mixed Glass Cullet Proppants for Stimulation of Oil and Natural Gas Bearing Shales · Modeling the Electrical Conductivity in Glass Melts.

377

Preparation of ?-Diketone Modified Silica Gel and its Application to ...  

Science Conference Proceedings (OSTI)

Biosorption Characteristics of Pb(II) from Aqueous Solution onto Poplar Cotton · Characterization of Aluminum Cathode Sheets Used for Zinc Electrowinning.

378

APPLICATIONS OF GEOTHERMALLY- PRODUCED COLLOIDAL SILICA IN RESERVOIR...  

NLE Websites -- All DOE Office Websites (Extended Search)

under Contract DE-AC52-07NA27344. Acknowledgment This work was sponsored by the Geothermal Technologies Office in the Department of Energy. 4 TABLE OF CONTENTS 1. Project...

379

Investigation of Mechanical Properties of Silica/Epoxy Nano ...  

Science Conference Proceedings (OSTI)

Application of Biomass Waste Materials in the Nano Mineral Synthesis ... Effect of Initial Microstructure on the Processing of Titanium Using Equal ... of Ferroelectric Poly(Vinylidene Fluoride-Trifluoroethylene) Copolymer Films ... Sonochemistry as a Tool for Synthesis of Ion-Substituted Calcium Phosphate Nanoparticles.

380

Methods for globally treating silica optics to reduce optical damage  

SciTech Connect

A method for preventing damage caused by high intensity light sources to optical components includes annealing the optical component for a predetermined period. Another method includes etching the optical component in an etchant including fluoride and bi-fluoride ions. The method also includes ultrasonically agitating the etching solution during the process followed by rinsing of the optical component in a rinse bath.

Miller, Philip Edward; Suratwala, Tayyab Ishaq; Bude, Jeffrey Devin; Shen, Nan; Steele, William Augustus; Laurence, Ted Alfred; Feit, Michael Dennis; Wong, Lana Louie

2012-11-20T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Chitosan–silica Hybrid Materials for Biomedical Applications  

Science Conference Proceedings (OSTI)

Microstructural Characteristics of Nano Calcium Phosphates Doped with Fluoride and Titanium Ions · Microwave Assisted Synthesis of Nano Hydroxyapatite ...

382

Thermal dependence of electrical characteristics of micromachined silica microchannel plates  

E-Print Network (OSTI)

Thermal dependence of electrical characteristics ofresults of our studies on the thermal properties of silicatemperature with a negative thermal coefficient of -0.036

Tremsin, A S; Vallerga, J V; Siegmund, OHW; Beetz, C P; Boerstler, R W

2004-01-01T23:59:59.000Z

383

Experimental study of an advanced silica gel dehumidifier  

DOE Green Energy (OSTI)

This report contains results of work done to experimentally characterize the performance of an advanced, rotary, desiccant dehumidifier and to develop and validate analytical methods for evaluating its performance in air-conditioning systems. A facility, the Cyclic Test Facility, and a test and analysis procedure were developed to evaluate the performance of the dehumidifier. A series of tests was undertaken to understand the simultaneous heat- and mass-transfer processes. An advanced dehumidifier test article was tested under cyclic operation to fully characterize its performance. Brief accounts of this facility, with its hardware and instrumentation, and detailed accounts of the test data and data reduction and analysis methods are presented. The data provide an engineering data base for evaluating rotary dehumidifiers for cooling applications. The dehumidifier's performance, as measured by the effectiveness, agreed with theory to within plus or minus 10%. 16 refs., 16 figs., 1 tab.

Bharathan, D.; Parsons, J.M.; Maclaine-cross, I.L.

1987-11-01T23:59:59.000Z

384

Iron(III)-doped, silica : biodegradable, self-targeting nanoparticles  

E-Print Network (OSTI)

Mixtures Worksheet” Answer Key for “Solutions and MixturesSolutions and Mixtures (Answer Key) Purpose: Today you will

Mitchell, Kristina Kalani Pohaku

2011-01-01T23:59:59.000Z

385

Functionalized Mesoporous Silica: An Effective Adsorbent for the ...  

Science Conference Proceedings (OSTI)

Gold thiosulfate, however, is not well-adsorbed by activated charcoal, making industrial scale use of thiosulfate for gold leaching impractical at present. Because ...

386

Simulations Reveal That Earth's Silica Is Predominantly Superficial...  

NLE Websites -- All DOE Office Websites (Extended Search)

from glass to ceramics, computer chips and fiber optic cables. Yet new quantum mechanics results generated by a team of physicists from Ohio State University (OSU) show that...

387

Incorporation of silica into baroplastic core-shell nanoparticles  

E-Print Network (OSTI)

Core-shell baroplastics are nanophase materials that exhibit pressure-induced flow at low temperatures and high pressures. Core-shell baroplastics used in this work are comprised of a low Tg poly(butyl acrylate) (PBA) core ...

Hewlett, Sheldon A

2006-01-01T23:59:59.000Z

388

A Microporous Silica Membrane for CO 2 Capture: Relating Gas ...  

Science Conference Proceedings (OSTI)

New and Improved Refractory Materials for Gasifiers using Flexible Feedstock · On pursuit of high performance and low cost of anode-supported SOFC.

389

Statistical analysis of a silica gel rotary dehumidifier  

SciTech Connect

A regression analysis was conducted on experimental data obtained during the testing of a solid desiccant dehumidifier at the Solar Energy Research Institute (SERI has since been renamed the National Renewable Energy Laboratory). The data obtained was studied using statistical techniques to determine the regression equation for the temperature and humidity at the processed air outlet of the dehumidifier. These variables determine the cooling capacity and efficiency (Coefficient of Performance) of any desiccant cooling cycle. The analysis is used to determine the relative impact the input parameters have on the outlet temperature and humidity.

Kini, A.; Waugaman, D.G.; Kettleborough, C.F. (Texas A and M Univ., College Station (United States))

1993-01-01T23:59:59.000Z

390

Titania Coated Silica Microspheres for High Efficiency Dye ...  

Science Conference Proceedings (OSTI)

These microspheres, if used in DSSCs, can boost the efficiency of solar cell ... In- situ Characterization of Intercalation-induced Damage of High Purity Graphite ...

391

Uptake of Organic Pollutants by Silica-Polycation-Immobilized  

E-Print Network (OSTI)

-3780. Surfactant Effects on Alpha Factors in Full-Scale Wastewater Aeration Systems, Water Research, in press (Stenstrom and Gilbert, 1981). This is because surfactants are more effective at low interfacial velocity. Objective of this work is to quantify the effects of surfactant accumulation at bubble interfaces. Datasets

Dubin, Paul D.

392

Development of Silica/Vanadia/ Titania Catalysts for Removal of  

E-Print Network (OSTI)

(subbituminous or lignite) coals. Therefore, need exists for a low cost Hg oxidation/capturing process. Activated power plants. However, the incremental cost of Hg control via ACI is estimated to range from $3810. This superior oxidation capability is advantageous to power plants equipped with wet-scrubbers where oxidized Hg

Li, Ying

393

Consolidation of Silica/Graphene Oxide Composite by Spark ...  

Science Conference Proceedings (OSTI)

Synthesis and Characterization of Plasma Polymerized Thin Films Deposited from Benzene and Hexamethyldisiloxane Using (PECVD) Method · Synthesis and ...

394

Effects of Incorporation of Silica and Zirconia Nanoparticles on the ...  

Science Conference Proceedings (OSTI)

Composites with weak interface showed essentially no change in Tg and damping or even ... On the other hand, incorporation of the particles did not alter the thermal ... of a Novel Hybrid Bimodal Network Elastomer with Inorganic Cross

395

Preparation of Silica Encapsulated Stearic Acid as Composite ...  

Science Conference Proceedings (OSTI)

Conference Tools for 2014 TMS Annual Meeting & Exhibition ... Symposium, Energy Technologies and Carbon Dioxide Management. Presentation Title ... Corrosion Behavior of Differently Heat Treated Steels in CCS Environment with Supercritical CO2 ... Life Cycle Assessment of Different Gold Extraction Process.

396

Synthesis and Characterization of Magnetic Silica Nanoparticles for ...  

Science Conference Proceedings (OSTI)

Atomic -Scale Characterization of Nb-Doped SrTiO?3 Nanostructures for .... Metal Oxide Nanofibers Produced by a ForceSpinning Method for Battery Electrodes.

397

Fluorescent single walled nanotube/silica composite materials  

DOE Patents (OSTI)

Fluorescent composites of surfactant-wrapped single-walled carbon nanotubes (SWNTs) were prepared by exposing suspensions of surfactant-wrapped carbon nanotubes to tetramethylorthosilicate (TMOS) vapor. Sodium deoxycholate (DOC) and sodium dodecylsulphate (SDS) were the surfactants. No loss in emission intensity was observed when the suspension of DOC-wrapped SWNTs were exposed to the TMOS vapors, but about a 50% decrease in the emission signal was observed from the SDS-wrapped SWNTs nanotubes. The decrease in emission was minimal by buffering the SDS/SWNT suspension prior to forming the composite. Fluorescent xerogels were prepared by adding glycerol to the SWNT suspensions prior to TMOS vapor exposure, followed by drying the gels. Fluorescent aerogels were prepared by replacing water in the gels with methanol and then exposing them to supercritical fluid drying conditions. The aerogels can be used for gas sensing.

Dattelbaum, Andrew M.; Gupta, Gautam; Duque, Juan G.; Doorn, Stephen K.; Hamilton, Christopher E.; DeFriend Obrey, Kimberly A.

2013-03-12T23:59:59.000Z

398

Devitrification of Fused Silica into Cristobalite in Sintered Powder ...  

Science Conference Proceedings (OSTI)

A History of the Theories of Glass Structure: Can We Really Believe What is ... Field Assisted Viscous Flow and Crystallization in a Sodium Aluminosilicate Glass ... Mechanisms of the Conversion Reaction in FeF2 Cathodes Exposed to Li in ...

399

Superhydrophobic Coatings Using Double-Silane Treated Silica ...  

Disclosure Number 201202928 Technology Summary This invention relates to superhydrophobic coatings and more specifically to durability improvements. ...

400

Flame-Retardant Mechanism of Silica: Effects of Resin ...  

Science Conference Proceedings (OSTI)

... During the collapse of the mound, numerous white, thin flakes were formed, as ... loss rate (burning rate) curves (not shown) were very close to those ...

2003-08-28T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Lidar characterization of crystalline silica generation and gravel plant  

E-Print Network (OSTI)

W.E. Eichinger, Elastic Lidar: Theory, Practice and AnalysisApplication of elastic e lidar to PM 10 emissions fromg m ?3 ) QTZ (?g m ?3 ) The lidar horizontal scans collected

Trzepla-Nabaglo, K.; Shiraki, R.; Holm'en, B. A.

2006-01-01T23:59:59.000Z

402

A CFD simulation on how the different sizes of silica gel will affect the adsorption performance of silica gel  

Science Conference Proceedings (OSTI)

The application of computational fluid dynamics (CFD) in the area of porous media and adsorption cooling system is becoming more practical due to the significant improvement in computer power. The results from previous studies have shown that CFD can ...

John White

2012-01-01T23:59:59.000Z

403

Phase 2 and 3 Slim Hole Drilling and Testing at the Lake City, California Geothermal Field  

DOE Green Energy (OSTI)

During Phases 2 and 3 of the Lake City GRED II project two slim holes were cored to depths of 1728 and 4727 ft. Injection and production tests with temperature and pressure logging were performed on the OH-1 and LCSH-5 core holes. OH-1 was permanently modified by cementing an NQ tubing string in place below a depth of 947 ft. The LCSH-1a hole was drilled in Quaternary blue clay to a depth of 1727 ft and reached a temperature of 193 oF at a depth of 1649 ft. This hole failed to find evidence of a shallow geothermal system east of the Mud Volcano but the conductive temperature profile indicates temperatures near 325 oF could be present below depth of 4000 ft. The LCSH-5 hole was drilled to a depth of 4727 ft and encountered a significant shallow permeability between depths of 1443 and 1923 ft and below 3955 ft. LCSH-5 drilled impermeable Quaternary fanglomerate to a depth of 1270 ft. Below 1270 ft the rocks consist primarily of Tertiary sedimentary rocks. The most significant formation deep in LCSH-5 appears to be a series of poikoilitic mafic lava flows below a depth of 4244 ft that host the major deep permeable fracture encountered. The maximum static temperature deep in LCSH-5 is 323 oF and the maximum flowing temperature is 329 oF. This hole extended the known length of the geothermal system by ¾ of a mile toward the north and is located over ½ mile north of the northernmost hot spring. The OH-1 hole was briefly flow tested prior to cementing the NQ rods in place. This flow test confirmed the zone at 947 ft is the dominant permeability in the hole. The waters produced during testing of OH-1 and LCSH-5 are generally intermediate in character between the deep geothermal water produced by the Phipps #2 well and the thermal springs. Geothermometers applied to deeper fluids tend to predict higher subsurface temperatures with the maximum being 382 oF from the Phipps #2 well. The Lake City geothermal system can be viewed as having shallow (elevation > 4000 ft and temperatures of 270 to 310 oF), intermediate (elevation 2800 to 3700 ft and temperatures 270 to 320 oF ) and deep (elevations < 1000 ft and temperatures 323 to 337 oF) components. In the south part of the field, near Phipps #2 the shallow and deep components are present. In the central part of the field, near OH-1 the shallow and intermediate components are present and presumably the deep component is also present. In the north part of the field, the intermediate and deep components are present. Most or all of the fractures in the core have dips between 45 degrees and vertical and no strong stratigraphic control on the resource has yet been demonstrated. Conceptually, the Lake City geothermal resource seems to be located along the north-south trending range front in a relatively wide zone of fractured rock. The individual fractures do not seem to be associated with any readily identifiable fault. In fact, no major hydraulically conductive faults were identified by the core drilling.

Dick Benoit; David Blackwell; Joe Moore; Colin Goranson

2005-10-27T23:59:59.000Z

404

Stopping the growth of particles to silica-supported mono-nuclear Ru hydride surface species by tuning silica with surface silanes  

E-Print Network (OSTI)

chemical grafting of Ru(COD)(COT) through a covalent Ru-Siof a pentane solution of Ru(COD)(COT) under 3 bars of H 2 inhigh temperatures of grafted Ru(COD)(COT), leading to stable

Berthoud, Romain

2009-01-01T23:59:59.000Z

405

Quantifying Silica Reactivity in Subsurface Environments: An Integrated Experimental Study of Quartz and Amorphous Silica to Establish a baseline for Glass Durability  

SciTech Connect

An immediate EM science need is a reliable kinetic model that predicts long-term waste glass performance.

Patricia Dove; Nizhou Han; Y. Thomas He

2005-11-15T23:59:59.000Z

406

Synthesis of attrition-resistant heterogeneous catalysts using templated mesoporous silica  

DOE Patents (OSTI)

The present invention relates to catalysts in mesoporous structures. In a preferred embodiment, the invention comprises a method for encapsulating a dispersed insoluble compound in a mesoporous structure comprising combining a soluble oxide precursor, a solvent, and a surfactant to form a mixture; dispersing an insoluble compound in the mixture; spray-drying the mixture to produce dry powder; and calcining the powder to yield a porous structure comprising the dispersed insoluble compound.

Pham, Hien N. (Albuquerque, NM); Datye, Abhaya K. (Albuquerque, NM)

2003-04-15T23:59:59.000Z

407

A Well-Defined, Silica-Supported Tungsten Imido Alkylidene Olefin Metathesis Catalyst  

E-Print Network (OSTI)

olefin metathesis catalyst. Bouchra Rhers, a Alain Salameh,active propene metathesis catalyst, which can achieve 16000W-based olefin metathesis catalyst through the reaction of [

2006-01-01T23:59:59.000Z

408

Nanostructured Cobalt Oxide Clusters in Mesoporous Silica as Efficient Oxygen-Evolving Catalysts  

E-Print Network (OSTI)

as Efficient Oxygen- Evolving Catalysts Feng Jiao and Heinzof efficient and robust catalysts for the chemicaltransformations. Catalysts need to exhibit turnover

Jiao, Feng

2010-01-01T23:59:59.000Z

409

Synthesis, characterization, and evaluation of silica and polymer supported catalysts for the production of fine chemicals .  

E-Print Network (OSTI)

??Catalysis is an important field of study in chemical engineering and chemistry due to its application in a vast number of chemical transformations. Traditionally, catalysts… (more)

Shiels, Rebecca Anne

2008-01-01T23:59:59.000Z

410

Water Diffusion and Interaction in Nano-porous Silica from First ...  

Science Conference Proceedings (OSTI)

Ion Exchanged Mixed Glass Cullet Proppants for Stimulation of Oil and Natural Gas Bearing Shales · Modeling the Electrical Conductivity in Glass Melts.

411

/sup 29/Si NMR study of the surface of pyrogenic silica modified by methylchlorosilanes  

SciTech Connect

Cross-polarization /sup 29/Si NMR spectra have been used for aerosil modified by methyl-chlorosilanes to identify surface organosilicon compounds and their reactions during hydrolysis and methanolysis.

Brie, V.V.; Gorlov, Yu.I.; Chuiko, A.A.

1986-11-01T23:59:59.000Z

412

/sup 11/B and /sup 13/C NMR studies on silica modified by borate esters  

Science Conference Proceedings (OSTI)

/sup 11/B and /sup 13/C NMR has been applied along with programmed desorption and boron analysis to the surface of aerosol specimens modified by trimethoxyborane and dimethoxybutylborane. It is concluded that methanol is coordinated to the boron atoms in the dimethoxyborosilyl groups.

Kasperskii, V.A.; Brei, V.V.; Gorlov, Yu.I.; Chuiko, A.A.

1988-07-01T23:59:59.000Z

413

Nanostructural organization of naturally occurring composites-part II: silica-chitin-based biocomposites  

Science Conference Proceedings (OSTI)

Investigations of the micro-and nanostructures and chemical composition of the sponge skeletons as examples for natural structural biocomposites are of fundamental scientific relevance. Recently, we show that some demosponges (Verongula gigantea, Aplysina ...

Hermann Ehrlich; Dorte Janussen; Paul Simon; Vasily V. Bazhenov; Nikolay P. Shapkin; Christiane Erler; Michael Mertig; René Born; Sascha Heinemann; Thomas Hanke; Hartmut Worch; John N. Vournakis

2008-01-01T23:59:59.000Z

414

Charging of silica particles in an argon dusty plasma Edward Thomas, Jr.a)  

E-Print Network (OSTI)

and the National Science Foundation. 1 C. K. Goertz, Rev. Geophys. 27, 271 1989 . 2 M. Horanyi and D. A. Mendis. Aucillo and D. Flamm Academic, Boston, 1989 , p. 113. 14 E. C. Whipple, T. G. Northrop, and D. A. Mendis

Thomas Jr., Edward

415

Hierarchical and size dependent mechanical properties of silica and silicon nanostructures inspired by diatom algae  

E-Print Network (OSTI)

Biology implements fundamental principles that allow for attractive mechanical properties, as observed in biomineralized structures. For example, diatom algae contain nanoporous hierarchical silicified shells that provide ...

García, Andre Phillipé

2010-01-01T23:59:59.000Z

416

245 Oxidation Behaviors of Silica Coated Mo-Si-B Alloys  

Science Conference Proceedings (OSTI)

021 Radiation Interactions in Biologically Important Materials ... 050 Investigation of ZnO:N and ZnO:(Al,N) Films for Solar Driven Hydrogen Production ... 070 A Phenomenological Thermodynamic Potential of CaTiO3 Single Crystals.

417

Linear and Nonlinear Spectroscopic Probing of Solute Interactions with Chemically Modified Silica Surfaces  

DOE Green Energy (OSTI)

Solar energy conversion through biology would provide a renewable and nonpolluting abundance of energy. The bacterium Halobacterium salinarum converts solar to electrical energy by virtue of a transmembrane protein, bacteriorhodopsin. This transmembrane protein pumps protons across a nonconducting bilayer upon irradiation with green light. The bacterium evolved to perform this function inefficiently. If we were able to understand this process to engineer this protein for efficiency, then inexpensive energy production could be achieved. There are tens of thousands of different types of halobacteria, giving the opportunity to study different efficiencies and relating these to the protein structures. Technology does not yet exist to perform such screening. The goal of this research is to generate new separation technology that can ultimately enable such screening. This involves creating a method for separating oriented and functional transmembrane proteins that remain in an electrically insulating lipid bilayer, with aqueous solutions on either side of the bilayer. A pH change across the lipid bilayer upon irradiation of a known concentration of proteins would probe function. Differences in proton pumping efficiency for different proteins variants would provide structure-function information for engineering the proteins. A schematic diagram from the original proposal is shown here. The idea is that (a) a lipid bilayer supported on a hydrophilic polymer film will make the bilayer fluid, and (b) applying an electric field will cause electrophoretic migration of the transmembrane proteins. We demonstrated this concept experimentally in a paper that was published just after this new grant period started (Lipid Bilayers on Polyacrylamide Brushes for Inclusion of Membrane Proteins, Emily A. Smith, Jason W. Coym, Scott M. Cowell, Victor J. Hruby, Henry I. Yamamura, Mary J. Wirth, Langmuir, 21, 9644-9650, 2005). The electrophoretic mobility was slow (10{sup -8} cm{sup 2}/Vs), and we project that a two order of magnitude increase would make this a practical tool. We are investigating two ways of improving electrophoretic mobility: better polymer supports, and a novel nanoporous medium that suspends the bilayer over free solution.

Wirth, Mary J

2011-02-09T23:59:59.000Z

418

Mesoporous silica as a membrane for ultra-thin implantable direct glucose Tushar Sharma,a  

E-Print Network (OSTI)

failure warning systems, glucose and electrolyte sensors with systems such as an automated implantable car-linked hydro- gels, sulfonated polypropylene and cuprophan,20­22 have been used to facilitate glucose diffusion and separate the electrodes. Rao et al.20,23 and Atanasov and Wilkins24 have used hydro- phobic membranes

419

Kaolinite Effects on Sintering of Freeze-Cast Kaolinite-Silica ...  

Science Conference Proceedings (OSTI)

Aerosol Jet® Material Deposition for High Resolution Printed Electronic Applications ... Carbon Nanotube Coatings Laser Power and Energy Measurements ... Rational Tailoring of 1-D (Nanowires), 2-D (Graphene) and 3-D (Ceramic/Carbon ...

420

Computational fluid dynamics modelling and experimental study on a single silica gel type B  

Science Conference Proceedings (OSTI)

The application of computational fluid dynamics (CFDs) in the area of porous media and adsorption cooling system is becoming more practical due to the significant improvement in computer power. The results from previous studies have shown that CFD can ...

John White

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "geothermometers silica geothermometers" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

STATE-OF-THE-ART: FLY ASH, SILICA FUME AND SLAG UTILIZATION IN USA  

E-Print Network (OSTI)

Backfill. 1.0 Introduction At the present time, coal fired electric power plants in the USA produce, ease of handling, and moisture insensitivity, etc. [2,11]. 2.1.2 Backfills Fly ash is used

Wisconsin-Milwaukee, University of

422

Fracture Propagation and Permeability Change under Poro-thermoelastic Loads & Silica Reactivity in Enhanced Geothermal Systems  

SciTech Connect

Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Therefore, knowledge of the conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fractures are created in the reservoir using hydraulic fracturing. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result, it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have developed advanced poro-thermo-chemo-mechanical fracture models for rock fracture research in support of EGS design. The fracture propagation models are based on a regular displacement discontinuity formulation. The fracture propagation studies include modeling interaction of induced fractures. In addition to the fracture propagation studies, two-dimensional solution algorithms have been developed and used to estimate the impact of pro-thermo-chemical processes on fracture permeability and reservoir pressure. Fracture permeability variation is studied using a coupled thermo-chemical model with quartz reaction kinetics. The model is applied to study quartz precipitation/dissolution, as well as the variation in fracture aperture and pressure. Also, a three-dimensional model of injection/extraction has been developed to consider the impact poro- and thermoelastic stresses on fracture slip and injection pressure. These investigations shed light on the processes involved in the observed phenomenon of injection pressure variation (e.g., in Coso), and allow the assessment of the potential of thermal and chemical stimulation strategies.

Ahmad Ghassemi

2009-10-01T23:59:59.000Z

423

Mesoporous silica nanoparticles as smart and safe devices for regulating blood biomolecule levels  

SciTech Connect

Stimuli-responsive end-capped MSN materials are promising drug carriers that securely deliver a large payload of drug molecules without degradation or premature release. A general review of the recent progress in this field is presented, including a summary of a series of hard and soft caps for drug encapsulation and a variety of internal and external stimuli for controlled release of different therapeutics, a discussion of the biocompatibility of MSN both in vitro and in vivo, and a description of the sophisticated stimuli-responsive systems with novel capping agents and controlled release mechanism. The unique internal and external surfaces of MSN were utilized for the development of a glucose-responsive double delivery system end-capped with insulin. This unique system consists of functionalized MSNs capable of releasing insulin when the concentration of sugar in blood exceeds healthy levels. The insulin-free nanoparticles are then up taken by pancreatic cells, and release inside of them another biomolecule that stimulates the production of more insulin. The in vivo application of this system for the treatment of diabetes requires further understanding on the biological behaviors of these nanoparticles in blood vessels. The research presented in this dissertation demonstrated the size and surface effects on the interaction of MSNs with red blood cell membranes, and discovered how the surface of the nanoparticles can be modified to improve their compatibility with red blood cells and avoid their dangerous side effects. In order to optimize the properties of MSN for applying them as efficient intracellular drug carriers it is necessary to understand the factors that can regulate their internalization into and exocytosis out of the cells. The correlation between the particle morphology and aggregation of MSNs to the effectiveness of cellular uptake is discussed and compared with different cell lines. The differences in the degree of exocytosis of MSNs between healthy and cancer cells is reported and found to be responsible for the asymmetric transfer of the particles between both cell types. The fundamental studies on the hemocompatibility, endo- and exocytosis of MSN along with its ability to sequentially release multiple therapeutics in response to different stimuli, allow us to propose MSN as an intravascular vehicle with a great potential for various biomedical applications.

Zhao, Yan

2011-05-15T23:59:59.000Z

424

Low Frequency Acoustic Resonance Studies of the Liquid-Vapor Transition in Silica Aerogel  

E-Print Network (OSTI)

Fluid phase transitions in porous media are a powerful probe of the effect of confinement and disorder on phase transitions. Aerogel may provide a model system in which to study the effect of dilute impurities on a variety of phase transitions. In this paper we present a series of low frequency acoustic experiments on the effect of aerogel on the liquid-vapor phase transition. Acoustic resonators were used to study the liquid-vapor transition in two fluids (helium and neon) and in two different porosity aerogels (95% and 98%). While effective coexistence curves could be mapped out, the transition was sometimes difficult to pinpoint, leading to doubt as to whether this transition can be treated as an equilibrium macroscopic phase transition at all.

Tobias Herman; John Beamish

2005-06-30T23:59:59.000Z

425

Electrical, textural and structural characterization of EMIMAc silica ionogels and their corresponding aerogels  

E-Print Network (OSTI)

and their corresponding aerogels N.Bengourna*, L.Bonnet1,2 , R.Courson , F.Despetis1,2 , N.Olivi-Tran1,2 , P.Solignac1 of these concentrations on the corresponding aerogels: pore size distributions and effectives surfaces. The structure of the aerogels was measured with a SAXS apparatus and was typical of acid catalyzed aerogels. Conductivity

Paris-Sud XI, Université de

426

Thermal conductivity of pure silica MEL and MFI zeolite thin films  

E-Print Network (OSTI)

k materials”. Angewandte Chemie International Edition, 45(zeolite ?lms13”. Angewandte Chemie International Edition,

Coquil, Thomas; Lew, Christopher M.; Yan, Yushan; Pilon, Laurent

2010-01-01T23:59:59.000Z

427

Luminescent organosilicon polymers and sol-gel synthesis of nano-structured silica  

E-Print Network (OSTI)

Polysiloles.  Angewandte  Chemie  2001,  113  (11),  2162-­?Polysiloles.  Angewandte  Chemie  2001,  113  (11),  2162-­?Polysiloles.  Angewandte  Chemie  2001,  113  (11),  2162-­?

Martinez, H. Paul

2011-01-01T23:59:59.000Z

428

Reflectance of Surfactant-Templated Mesoporous Silica Thin Films: Simulations Versus Experiments  

E-Print Network (OSTI)

Annalen der Physik und Chemie, Leipzig (1895) 661–679. o [Annalen der Physik und Chemie 247 (9) [25] H. Lorentz, UeberAnnalen der Physik und Chemie 245 (4) (1880) 641–665. o [26

Hutchinson, Neal J.; Coquil, Thomas; Richman, Eric K.; Tolbert, Sarah H; Pilon, Laurent

2010-01-01T23:59:59.000Z

429

Alkaline Pressure Oxidation of Pyrite in the Presence of Silica – Characterization of the Passivating Film.  

E-Print Network (OSTI)

??Alkaline pressure oxidation, particularly in the presence of trona as additive, can be used to oxidize high carbonate refractory gold ores as it prevents the… (more)

Dani, Anirudha

2013-01-01T23:59:59.000Z

430

A New Concept for the Fabrication of Hydrogen Selective Silica Membranes  

DOE Green Energy (OSTI)

It was proposed to investigate a new concept for the synthesis of molecular sieve hydrogen selective membranes. This concept is based on the use of exfoliated layered zeolite precursors in coating processes to make nanocomposite films with inorganic or polymeric matrices. We discovered that creating exfoliated zeolite layers was much more difficult than anticipated because the methods originally proposed (based on existing literature reports) were not successful in providing exfoliated layers while preserving their porous structure. Although the original goals of fabricating high-selectivity-high-flux membranes that are stable under conditions present in a water-gas-shift reactor and that are able to selectively permeate hydrogen over all other components of the mixtures present in these reactors were not accomplished fully, significant progress has been made as follows: (1) Proof-of-concept hydrogen-selective nanocomposite membranes have been fabricated; (2) Methods to exfoliate layered zeolite precursors preserving the layer structure were identified; and (3) Unexpectedly, membranes exhibiting high ideal selectivity for carbon dioxide over nitrogen at room temperature were produced. The findings listed above provide confidence that the proposed novel concept can eventually be realized.

Michael Tsapatsis

2009-01-07T23:59:59.000Z

431

Persuance of Silica on Morphology and CO2/CH4 Gas Permeation ...  

Science Conference Proceedings (OSTI)

... in order to prevent condensation of water in the flat sheet membrane module. ... Mechanical and Physical Properties of Roof Tile Manufacturing from Red Mud.

432

Structure sensitive adsorption of hydrogen on ruthenium and ruthenium-silver catalysts supported on silica  

DOE Green Energy (OSTI)

Supported metal catalysts typically consist of particles with sizes less than 10 nm, and because of the small crystallite size, low coordination number sites (edges and corners) represent a significant fraction of all surface sites. Furthermore, it has been demonstrated that adsorption rates can be much greater at these low coordination sites than on basal plane sites. What has not been generally appreciated, however, is that preferential adsorption at edge and corner sites may explain the mechanism by which a promoter, or the addition of a second metal to form a bimetallic, can alter the selectivity and rate of reaction. For example, the measurements of hydrogen adsorption onto supported Ru-Ag catalysts show marked decreases in the amount of hydrogen adsorbed relative to the amount adsorbed on Ru catalysts. Although it is known that Ag does not dissociatively adsorb hydrogen, this decrease cannot be explained by a simple one-to-one site blocking mechanism unless Ag preferentially populates edges and corners, thereby reducing the number of Ru edge sites. Indeed, Monte Carlo simulations of Ru-Group IB metal catalysts predict that Group IB metal atoms preferentially populate corner and edge sites of ruthenium crystals. This evidence, taken together, suggests that adsorption occurs preferentially at Ru corner and edge sites, which act as portals onto basal planes. A model based on this portal theory for hydrogen adsorption onto supported ruthenium bimetallic catalysts has been developed using a rate equation approach. Specifically, the model accounts for the following features: (1) preferential adsorption through portals, (2) basal plane site-energy multiplicity, and (3) hydrogen spillover onto the support. A comparison of model predictions with experiment is presented for different concentration of Ag in Ru-Ag catalysts. The portal model of hydrogen adsorption can explain the observed decreased in the amount of hydrogen adsorbed on Ru-Ag catalysts. The model can be applied to understand the kinetics of ethane hydrogenolysis on Ru-Ag catalysts. The model is able to explain the change in the apparent order of hydrogenolysis reaction with respect to hydrogen from {minus}1.4 to {minus}2.4 when Ag is added to Ru/SiO{sub 2} catalyst.

Kumar, N.

1999-02-12T23:59:59.000Z

433

MOLECULAR DYNAMICS STUDY OF THE THERMAL CONDUCTIVITY OF AMORPHOUS NANOPOROUS SILICA  

E-Print Network (OSTI)

Domain size effects in molecular dynamics simulation ofC. H. , 2010. “Size effects in molecular dynamics thermaland nanowires using molecular dynamics simulations”.

Coquil, Thomas; Fang, Jin; Pilon, Laurent

2011-01-01T23:59:59.000Z

434

Nanostructured electrocatalyst for fuel cells : silica templated synthesis of Pt/C composites.  

DOE Green Energy (OSTI)

Platinum-based electrocatalysts are currently required for state-of-the-art fuel cells and represent a significant portion of the overall fuel cell cost. If fuel cell technology is to become competitive with other energy conversion technologies, improve the utilization of precious metal catalysts is essential. A primary focus of this work is on creating enhanced nanostructured materials which improve precious-metal utilization. The goal is to engineer superior electrocatalytic materials through the synthesis, development and investigation of novel templated open frame structures synthesized in an aerosol-based approach. Bulk templating methods for both Pt/C and Pt-Ru composites are evaluated in this study and are found to be limited due to the fact that the nanostructure is not maintained throughout the entire sample. Therefore, an accurate examination of structural effects was previously impossible. An aerosol-based templating method of synthesizing nanostructured Pt-Ru electrocatalysts has been developed wherein the effects of structure can be related to electrocatalytic performance. The aerosol-based templating method developed in this work is extremely versatile as it can be conveniently modified to synthesize alternative materials for other systems. The synthesis method was able to be extended to nanostructured Pt-Sn for ethanol oxidation in alkaline media. Nanostructured Pt-Sn electrocatalysts were evaluated in a unique approach tailored to electrocatalytic studies in alkaline media. At low temperatures, nanostructured Pt-Sn electrocatalysts were found to have significantly higher ethanol oxidation activity than a comparable nanostructured Pt catalyst. At higher temperatures, the oxygen-containing species contribution likely provided by Sn is insignificant due to a more oxidized Pt surface. The importance of the surface coverage of oxygen-containing species in the reaction mechanism is established in these studies. The investigations in this work present original studies of anion exchange ionomers as entrapment materials for rotating disc electrode (RDE) studies in alkaline media. Their significance is linked to the development of membrane electrode assemblies (MEAs) with the same ionomer for a KOH-free alkaline fuel cell (AFC).

Stechel, Ellen Beth; Switzer, Elise E.; Fujimoto, Cy H.; Atanassov, Plamen Borissov; Cornelius, Christopher James; Hibbs, Michael R.

2007-09-01T23:59:59.000Z

435

Structural Characterization of Germanium and Gold - Germanium Nanoclusters Embedded in Silica  

E-Print Network (OSTI)

X-ray diffraction at SSRL. I would also like to thankexperiments were performed at SSRL, a national user facilityRadiation Lightsource (SSRL) to assess the crystal structure

Guzman, Julian

2011-01-01T23:59:59.000Z

436

Brief Communication Liposome encapsulation of fluorescent nanoparticles: Quantum dots and silica  

E-Print Network (OSTI)

nanoparticles Chien-Sheng Chen1 , Jie Yao2 and Richard A. Durst1, * 1 Department of Food Science & Technology & Durst, 2000; Esch et al., 2001; Ahn-Yoon et al., 2003; Baeumner et al., 2004; Ho et al., 2004

Chen, Chien-Sheng

437

Ostwald ripening of platinum nanoparticles confined in a carbon nanotube/silica-templated cylindrical space  

Science Conference Proceedings (OSTI)

Sintering of nanoparticles mediated by an Ostwald ripening mechanism is generally assessed examining the final particle size distributions. Based on this methodology, a general approach for depositing platinum nanoparticles onto carbon nanotubes in solution ...

Cintia Mateo-Mateo, Carmen Vázquez-Vázquez, Moisés Pérez-Lorenzo, Verónica Salgueiriño, Miguel A. Correa-Duarte

2012-01-01T23:59:59.000Z

438

Mechanical properties of surface modified silica low-k thin films  

Science Conference Proceedings (OSTI)

The surface modification of sol-gel deposited low-k thin films has been carried out successfully by trimethylchlorosilane (TMCS) using wet chemical treatment method. Ellipsometer is used to determine the thickness of films. The changes in chemical structure ... Keywords: Contact angle, Hydrophobic, Nano-indentation, Sol-gel, Surface modification

Yogesh S. Mhaisagar, Bhavana N. Joshi, Ashok M. Mahajan

2014-02-01T23:59:59.000Z

439

Atomic layer deposition of ZnO on ultralow-density nanoporous silica aerogel monoliths  

Science Conference Proceedings (OSTI)

We report on atomic layer deposition of an ? 2 -nm-thick ZnO layer on the inner surface of ultralow-density ( ? 0.5 % of the full density) nanoporoussilica aerogel monoliths with an extremely large effective aspect ratio of ? 10 5 (defined as the ratio of the monolith thickness to the average pore size). The resultant monoliths are formed by amorphous- SiO 2 core/wurtzite-ZnO shell nanoparticles which are randomly oriented and interconnected into an open-cell network with an apparent density of ? 3 % and a surface area of ? 10 0 m 2 g ? 1 . Secondary ion mass spectrometry and high-resolution transmission electron microscopy imaging reveal excellent uniformity and crystallinity of ZnO coating. Oxygen K -edge and Zn L 3 -edge soft x-ray absorption near-edge structure spectroscopy shows broadened O p - as well as Zn s - and d -projected densities of states in the conduction band.

S. O. Kucheyev; J. Biener; Y. M. Wang; T. F. Baumann; K. J. Wu; T. van Buuren; A. V. Hamza; J. H. Satcher Jr.; J. W. Elam; M. J. Pellin

2005-01-01T23:59:59.000Z

440

Effect of Residual Tritiated Water on Air Detritiation Dryer Packed with Silica Gel  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

Yasunori Iwai; Toshihiko Yamanishi

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441

Vertical flux, ecology and dissolution of radiolaria in tropical oceans : implications for the silica cycle  

E-Print Network (OSTI)

Radiolarians which settle through the oceanic water column were recovered from three stations (western Tropical Atlantic-Station E, central Tropical Pacific-P1 and Panama Basin-PB) using PARFLUX sediment traps in moored ...

Takahashi, Kozo

1982-01-01T23:59:59.000Z

442

First-Principles Investigation of Low Energy E' Center Precursors in Amorphous Silica  

SciTech Connect

We show that oxygen vacancies are not necessary for the formation of E’ centers in amorphous SiO2 and that a single O-deficiency can lead to two charge traps. Employing molecular dynamics with a reactive potential and density functional theory we generate an ensemble of stoichiometric and oxygen-deficient amorphous SiO2 atomic structures and identify low-energy network defects. Three-coordinated Si atoms appear in several low-energy defects both in stoichiometric and O-deficient samples where, in addition to the neutral oxygen vacancy, they appear as isolated defects.

Anderson, Nathan L.; Vedula, Ravi P.; Schultz, Peter A.; Van Ginhoven, Renee M.; Strachan, Alejandro

2011-05-17T23:59:59.000Z

443

Temperature-dependent Structural Arrest of Silica Colloids in a Water–lutidine Binary Mixture  

Science Conference Proceedings (OSTI)

We study the onset of structural arrest and glass formation in a suspension of silicananoparticles in a water-lutidine binary mixture near its consolute point. By exploiting the near-critical fluid degrees of freedom to control the strength of an attraction between particles and multispeckle X-ray photon correlation spectroscopy to characterize the particles collective dynamics, we show that this model liquid undergoes a glass transition both on cooling and on heating, and that the intermediate liquid realizes unusual logarithmic relaxations. We are able to characterize in unprecedented detail how vitrification occurs for the two different glass transitions observed, and draw comparisons to recent theoretical predictions for glass formation in systems with attractive interactions.

Lu, X.; Mochrie, S.G.J.; Narayanan, S.; Sandy, A.R.; Sprung, M.

2010-12-21T23:59:59.000Z

444

Multiphase imaging of gas flow in a nanoporous material using remote detection NMR  

E-Print Network (OSTI)

determinations of silica aerogels by 129 Xe NMR spectroscopyapplications of silica aerogels”, J. Non-Cryst. Solids ,analysis of silica aerogels”, J. Non-Cryst. Solids , 186,

Harel, Elad; Granwehr, Josef; Seeley, Juliette A.; Pines, Alex

2005-01-01T23:59:59.000Z

445

REDUCTION OF NITRIC OXIDE BY CARBON MONOXIDE OVER A SILICA SUPPORTED PLATINUM CATALYST: INFRARED AND KINETIC STUDIES  

E-Print Network (OSTI)

System. • B. Procedures. Catalyst Preparation Infrared DiskPreparation. Catalyst Characterization. PreliminaryReduction by CO Over a Pt Catalyst," M.S. thesis, Department

Lorimer, D.H.

2011-01-01T23:59:59.000Z

446

Measurement of near-surface void fraction and macrolayer thickness in boiling water and silica-based nanofluid  

E-Print Network (OSTI)

Nanofluids are engineered fluids that contain a suspension of nanoparticles in a pure substance. Nanoparticles can be any variety of metals, metal oxides, or ceramics. They have been shown to increase heat transfer properties ...</