Powered by Deep Web Technologies
Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


1

Effects of asymmetry on electron spin dynamics in gallium arsenide quantum wells.  

E-Print Network (OSTI)

??This work presents optical studies of electron spin dynamics in gallium arsenide (GaAs) quantum wells, focusing on the effect of inversion asymmetric confinement potentials on… (more)

Eldridge, Peter Stephen

2009-01-01T23:59:59.000Z

2

Oxidation of gallium arsenide  

DOE Patents (OSTI)

This invention relates to gallium arsenide semiconductors and, more particularly, to the oxidation of surface layers of gallium arsenide semiconductors for semiconductor device fabrication.

Hoffbauer, M.A.; Cross, J.B.

1991-11-16T23:59:59.000Z

3

TESLA-FEL 2007-03 Application of low cost GaAs LED as neutron  

E-Print Network (OSTI)

neutrons in unbiased Gallium Arsenide (GaAs) Light Emitting Diodes (LED) resulted in a reduction Keywords: COTS components, Displacement damage, Electron Linear Accelerator, GaAs Light emitting diode (LED) Gallium Arsenide (GaAs) light emitting diode (LED) for the assessment of integrated neutron fluence

4

Single event upsets in gallium arsenide dynamic logic  

SciTech Connect

The advantages and disadvantages of using gallium arsenide (GaAs) dynamic logic in computers and digital systems are briefly discussed, especially with respect to space applications. A short introduction to the topology and operation of GaAs Two-Phase Dynamic FET Logic (TDFL) circuits is presented. Experiments for testing the SEU sensitivity of GaAs TDFL, using a laser to create charge collection events, are described. Results are used to estimate the heavy-ion, soft error rate for TDFL in a spacecraft in geosynchronous orbit, and the dependence of the SEU sensitivity on clock frequency, clock voltage, and clock phase. Analysis of the data includes a comparison between the SEU sensitivities of TDFL and the more common static form of GaAs logic, Directly Coupled FET Logic (DCFL). This is the first reported SEU testing of GaAs dynamic logic.

Fouts, D.J. (Naval Postgraduate School, Monterey, CA (United States). ECE Dept.); Weatherford, T. (SFA Inc., Landover, MD (United States)); McMorrow, C.; Melinger, J.S.; Campbell, A.B. (Naval Research Lab., Washington, DC (United States))

1994-12-01T23:59:59.000Z

5

Simple intrinsic defects in GaAs : numerical supplement.  

SciTech Connect

This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

Schultz, Peter Andrew

2012-04-01T23:59:59.000Z

6

Single event upsets in gallium arsenide pseudo-complementary MESFET logic  

SciTech Connect

An introduction to gallium arsenide (GaAs) Pseudo-Complementary MESFET Logic (PCML) circuits is presented. PCML was developed to reduce the sensitivity of high-speed GaAs logic to radiation-induced single event upsets (SEUs). Experiments for testing the single-event upset (SEU) sensitivity of GaAs PCML integrated circuits (ICs) are described. The results of the experiments are analyzed. This new type of high-speed, low-power, GaAs logic provides decreased sensitivity to SEUs compared to more traditional circuit designs such as Directly-Coupled FET Logic (DCFL). PCML is fully compatible with existing GaAs E/D MESFET fabrication processes, such as those commonly used to make DCFL.

Fouts, D.J.; Wolfe, K.; Van Dyk, S.E. [Naval Postgraduate School, Monterey, CA (United States). Dept. of Electrical and Computer Engineering; Weatherford, T.R. [SFA Inc., Landover, MD (United States); McMorrow, D.; Melinger, J.S.; Tran, L.H.; Campbell, A.B. [Naval Research Lab., Washington, DC (United States)

1995-12-01T23:59:59.000Z

7

Outdoor Performance of a Thin-Film Gallium-Arsenide Photovoltaic Module  

SciTech Connect

We deployed a 855 cm2 thin-film, single-junction gallium arsenide (GaAs) photovoltaic (PV) module outdoors. Due to its fundamentally different cell technology compared to silicon (Si), the module responds differently to outdoor conditions. On average during the test, the GaAs module produced more power when its temperature was higher. We show that its maximum-power temperature coefficient, while actually negative, is several times smaller in magnitude than that of a Si module used for comparison. The positive correlation of power with temperature in GaAs is due to temperature-correlated changes in the incident spectrum. We show that a simple correction based on precipitable water vapor (PWV) brings the photocurrent temperature coefficient into agreement with that measured by other methods and predicted by theory. The low operating temperature and small temperature coefficient of GaAs give it an energy production advantage in warm weather.

Silverman, T. J.; Deceglie, M. G.; Marion, B.; Cowley, S.; Kayes, B.; Kurtz, S.

2013-06-01T23:59:59.000Z

8

Composition and Leaching of FGD Gypsum and Mined Gypsum  

Science Conference Proceedings (OSTI)

Flue gas desulfurization (FGD) equipment on new and existing coal-fired power plants controls sulfur dioxide (SO2) emissions, and produces a solid that is removed in either slurry or dry form. EPRI sponsored an investigation to characterize FGD gypsum8212the solid produced by wet FGD systems with forced air oxidation8212from a representative sampling of U.S. power plants. A single contractor collected 32 samples from 29 power plants in 13 states. In addition, 11 natural gypsum samples from mines in the U...

2011-11-03T23:59:59.000Z

9

Flue Gas Desulfurization Gypsum Agricultural Network  

Science Conference Proceedings (OSTI)

Flue gas desulfurization (FGD) gypsum is a solid produced by wet FGD systems with forced air oxidation and is chemically similar to mined gypsum. These gypsums, used as beneficial agricultural amendments, were evaluated for their effects on earthworm populations and trace element concentrations in soils and earthworms at four field sites (Ohio, Indiana, Alabama, and Wisconsin). These sites are part of a network study on agricultural uses of FGD gypsum conducted at sites across the United States. ...

2012-09-19T23:59:59.000Z

10

Coated gallium arsenide neutron detectors : results of characterizationmeasurements.  

DOE Green Energy (OSTI)

Effective detection of special nuclear materials (SNM) is essential for reducing the threat associated with stolen or improvised nuclear devices. Passive radiation detection technologies are primarily based on gamma-ray detection and subsequent isotope identification or neutron detection (specific to neutron sources and SNM). One major effort supported by the Department of Homeland Security in the area of advanced passive detection is handheld or portable neutron detectors for search and localization tasks in emergency response and interdiction settings. A successful SNM search detector will not only be able to confirm the presence of fissionable materials but also establish the location of the source in as short of time as possible while trying to minimize false alarms due to varying background or naturally occurring radioactive materials (NORM). For instruments based on neutron detectors, this translates to detecting neutrons from spontaneous fission or alpha-n reactions and being able to determine the direction of the source (or localizing the source through subsequent measurements). Polyethylene-coated gallium arsenide detectors were studied because the detection scheme is based on measuring the signal in the gallium arsenide wafers from the electrical charge of the recoil protons produced from the scattering of neutrons from the hydrogen nucleus. The inherent reaction has a directional dependence because the neutron and hydrogen nucleus have equivalent masses. The assessment and measurement of polyethylene-coated gallium arsenide detector properties and characteristics was the first phase of a project being performed for the Department of Homeland Security and the results of these tests are reported in this report. The ultimate goal of the project was to develop a man-portable neutron detection system that has the ability to determine the direction of the source from the detector. The efficiency of GaAs detectors for different sizes of polyethylene layers and different angles between the detector and the neutron source were determined. Preliminary measurements with a neutron generator based on a deuterium-tritium reaction ({approx}14 MeV neutrons) were performed and the results are discussed. This report presents the results of these measurements in terms of efficiency and angular efficiency and compares them to Monte Carlo calculations to validate the calculation scheme in view of further applications. Based on the results of this study, the polyethylene-coated gallium arsenide detectors provide adequate angular resolution based on proton recoil detection from the neutron scattering reaction from hydrogen. However, the intrinsic efficiency for an individual detector is extremely low. Because of this low efficiency, large surface area detectors ( or a large total surface area from many small detectors) would be required to generate adequate statistics to perform directional detection in near-real time. Large surface areas could be created by stacking the detector wafers with only a negligible attenuation of source neutrons. However, the cost of creating such a large array of GaAs is cost-prohibitive at this time.

Klann, R. T.; Perret, G.; Sanders, J.

2006-09-29T23:59:59.000Z

11

Phospho-gypsum recovery process  

SciTech Connect

This patent describes a process for treating phospho-gypsum waste product which is produced in the manufacture of phosphoric acid by the wet-acid process in which suitable phosphate rock is treated with sulforic acid to product phosphoric acid and in which a mixture of phospho-gypsum waste product and carbonaceous material is heated to produce gaseous SO/sub 2/, P/sub 2/O/sub 5/ containing materials and HF containing materials. The improvement comprises drying a mixture of phospho-gypsum waste product and carbonaceous material, removing a first gaseous stream containing water, acids and fluorine, separating the fluorine from the first gaseous stream by reacting with lime or limestone to produce fluorspar, recovering the fluorspar, calcining the dried phospho-gypsum under reducing conditions to produce a second gaseous stream containing SO/sub 2/, CO/sub 2/, O/sub 2/ and N/sub 2/ with substantially no fluorine values, and utilizing the second gaseous stream in a sulfuric acid manufacturing plant.

Wilson, E.K. Sr.; Spigolon, S.J.

1988-03-29T23:59:59.000Z

12

Flue Gas Desulfurization Gypsum Agricultural Network  

Science Conference Proceedings (OSTI)

Increasing volumes of flue gas desulfurization (FGD) gypsum will become available for agricultural use as more utilities install forced oxidation scrubbers and the wallboard market for the resulting gypsum becomes saturated. This interim report describes work performed in 2007 and 2008 to develop a national research network to gain data and experience to support the beneficial uses of FGD products, especially FGD gypsum, in agriculture and other land applications.

2008-12-12T23:59:59.000Z

13

Flue Gas Desulfurization Gypsum Agricultural Network  

Science Conference Proceedings (OSTI)

Research on flue gas desulfurization gypsum (FGDG) has been conducted under the auspices of the Flue Gas Desulfurization Gypsum Agricultural Network program sponsored by the Electric Power Research Institute (EPRI) in collaboration with individual utilities, the U.S. Environmental Protection Agency, U.S. Department of Agriculture-Agricultural Research Service, and universities. This report describes work conducted in northwestern New Mexico in 2008–2012 as part of that effort. Two separate ...

2012-10-15T23:59:59.000Z

14

Gypsum, Colorado: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Gypsum, Colorado: Energy Resources Gypsum, Colorado: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 39.6469295°, -106.9517109° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":39.6469295,"lon":-106.9517109,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

15

Process for forming pure silver ohmic contacts to N- and P-type gallium arsenide materials  

DOE Patents (OSTI)

Disclosed is an improved process for manufacturing gallium arsenide semiconductor devices having as its components a n-type gallium arsenide substrate layer and a p-type gallium arsenide diffused layer. The improved process comprises forming a pure silver ohmic contact to both the diffuse layer and the substrate layer wherein the n-type layer comprises a substantially low doping carrier concentration.

Hogan, S.J.

1983-03-13T23:59:59.000Z

16

Pure silver ohmic contacts to N- and P- type gallium arsenide materials  

DOE Patents (OSTI)

Disclosed is an improved process for manufacturing gallium arsenide semiconductor devices having as its components an n-type gallium arsenide substrate layer and a p-type gallium arsenide diffused layer. The improved process comprises forming a pure silver ohmic contact to both the diffused layer and the substrate layer, wherein the n-type layer comprises a substantially low doping carrier concentration.

Hogan, Stephen J. (Golden, CO)

1986-01-01T23:59:59.000Z

17

Analytical determination of fluorides in South African chemical gypsum.  

E-Print Network (OSTI)

??Fluoride ion is an accompanying impurity in a wide variety of chemical gypsum throughout the world. In this study, the Ion Selective Electrode (ISE) method,… (more)

Motalane, Mpempe Paulus

2005-01-01T23:59:59.000Z

18

Method for improving the growth of cadmium telluride on a gallium arsenide substrate  

DOE Patents (OSTI)

A method for preparing a gallium arsenide substrate, prior to growing a layer of cadmium telluride on a support surface thereof. The preparation includes the steps of cleaning the gallium arsenide substrate and thereafter forming prepatterned shapes on the support surface of the gallium arsenide substrate. The layer of cadmium telluride then grown on the prepared substrate results in dislocation densities of approximately 1{times}10{sup 6}/cm{sup 2} or less. The prepatterned shapes on the support surface of the gallium arsenide substrate are formed by reactive ion etching an original outer surface of the gallium arsenide substrate and into the body of the gallium arsenide substrate to a depth of at least two microns. The prepatterned shapes have the appearance of cylindrical mesas each having a diameter of at lease twelve microns. After the mesas are formed on the support surface of the gallium arsenide substrate, the substrate is again cleaned.

Reno, J.L.

1990-12-31T23:59:59.000Z

19

Carbon Dioxide Sequestration with Flue Gas Desulfurization (FGD) Gypsum  

Science Conference Proceedings (OSTI)

Carbonation of industrial alkaline residues can be used as a CO2 sequestration technology to reduce carbon dioxide emissions. In this study, alkaline Ca-rich flue gas desulfurization (FGD) gypsum samples were carbonated to a varying extent. These materials ... Keywords: FGD gypsum, carbonation, carbon dioxide

Hongqi Wang; Ningning Sun; Rona J. Donahoe

2009-07-01T23:59:59.000Z

20

A Study of the Activated GaAs Surface for Application as an Electron Source in Particle Accelerators  

Science Conference Proceedings (OSTI)

The use of type III-V semiconductor materials as photocathodes has in recent years become a focus for the High Energy Physics community. Once activated to a negative electron affinity (NEA) state and illuminated by a laser, these materials can be used as a high-brightness source of both polarised and un-polarised electrons in some modern accelerators, for example, ALICE (Accelerators and Lasers in Combined Experiments) at Daresbury Laboratory. This paper will focus on the use of gallium arsenide (GaAs) as a photocathode, and detail the reconfiguration and re-commissioning of two vacuum systems that support standard surface science techniques such as ultraviolet/X-ray photoelectron spectroscopy (UPS/XPS), low energy electron diffraction (LEED) and auger electron spectroscopy (AES). The paper will present details of cleaning GaAs in order to maximise quantum efficiency and will provide evidence from XPS and LEED to demonstrate what is happening at the atomic level.

Chanlek, N. [University of Manchester, Manchester, M13 9PL (United Kingdom); STFC Daresbury Laboratory, Warrington, WA4 4AD (United Kingdom); Herbert, J. D.; Jones, L. B.; Middleman, K. J. [STFC Daresbury Laboratory, Warrington, WA4 4AD (United Kingdom); Jones, R. M. [University of Manchester, Manchester, M13 9PL (United Kingdom)

2009-08-04T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

A Review of Manufacturing Uses for Gypsum Produced by Flue Gas Desulfurization Systems  

Science Conference Proceedings (OSTI)

Gypsum is widely used as a source material to manufacture products for building construction applications8212primarily wallboard, cement, and concrete8212and has a number of other commercial applications. The mineral is mined throughout the world (natural gypsum) and also is produced as a result of various industrial processes (synthetic gypsum). The largest source of synthetic gypsum used for manufacturing applications is flue gas desulfurization (FGD) gypsum, the product of wet flue gas desulfurization...

2006-03-07T23:59:59.000Z

22

Crack coalescence in molded gypsum and Carrara marble  

E-Print Network (OSTI)

This thesis investigates the fracturing and coalescence behavior in prismatic laboratory molded gypsum and Carrara marble specimens, which consist of either one or two preexisting open flaws, under uniaxial compression. ...

Wong, Ngai Yuen

2008-01-01T23:59:59.000Z

23

Rapid liquid phase epitaxial growth studies of GaAs: Final report, July 1984-June 1987  

Science Conference Proceedings (OSTI)

Single crystal layers of gallium arsenide have been grown on (111) and (100) oriented GaAs substrates from a flowing, GaAs saturated, gallium solution with a few degrees temperature differential across the liquid/solid interface. Very high growth rates, on the order of 8..mu..m per minute, have been observed. Such rates are in agreement with the growth theory developed as part of this program, and are about two orders greater than those typically achieved in conventional, static solution, liquid phase epitaxy. Both undoped and p-doped (Si) GaAs layers have been grown and some of their material properties measured. Good crystallinity was inferred from the narrowness of x-ray diffraction lines and from the intensities of the photoluminescence responses of all specimens sampled. While these results do not prove that the epi material is of photovoltaic quality, they indicate both a high crystallographic perfection and a low density of life-time poisoning impurities; conditions which are usually necessary for PV device development. Thus far, smooth surfaces have not been produced directly by the rapid liquid phase epitaxy (RLPE) process. The rough surface morphologies are due, at least in part, to incomplete wipe off of the liquid when the substrate is withdrawn at the end of the growth cycle. Another potential source is growth instabilities which will be discussed later. This report summarizes the three year research program of the RLPE process sponsored by DOE-SOLERAS.

Gerritsen, H.J.; Crisman, E.E.

1987-01-01T23:59:59.000Z

24

IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 2, APRIL 2012 123 Gallium Arsenide Solar Cell Absorption  

E-Print Network (OSTI)

IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 2, APRIL 2012 123 Gallium Arsenide Solar Cell Absorption flat gallium arsenide solar cell, we show that it is possible to modify the flow of light and enhance above the solar cell. The incoupling element is lossless and, thus, has the advantage that no energy

Grandidier, Jonathan

25

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production  

SciTech Connect

This report presents and discusses results from Task 5 of the study ''Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,'' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. The FGD process is used to control the sulfur dioxide emissions which would result in acid rain if not controlled. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies developed for power plants involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the atmosphere when the synthetic gypsum material is used as a feedstock for wallboard production. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope includes five discrete tasks, each conducted at various USG wallboard plants using synthetic gypsum from different FGD systems. The five tasks were to include (1) a baseline test, then variations representing differing power plant (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5, which was to evaluate gypsum produced from an alternate FGD reagent, could not be conducted as planned. Instead, Task 5 was conducted at conditions similar to a previous task, Task 3, although with gypsum from an alternate FGD system. In this project, process stacks in the wallboard plant have been sampled using the Ontario Hydro method. The stack locations sampled for each task include a dryer for the wet gypsum as it enters the plant and a gypsum calciner. The stack of the dryer for the wet wallboard product was also tested as part of this task, and was tested as part of Tasks 1 and 4. Also at each site, in-stream process samples were collected and analyzed for mercury concentration before and after each significant step in wallboard production. The Ontario Hydro results, process sample mercury concentration data, and process data were used to construct mercury mass balances across the wallboard plants. Task 5 was conducted at a wallboard plant processing synthetic gypsum from a power plant that fires Eastern bituminous coal. The power plant is equipped with a selective catalytic reduction (SCR) system for NOX emissions control, but the SCR was bypassed during the time period the gypsum tested was produced. The power plant has a single-loop, open spray tower, limestone reagent FGD system, with forced oxidation conducted in a reaction tank integral with the FGD absorber. The FGD system has gypsum fines blow down as part of the dewatering step. Gypsum fines blow down is believed to be an important variable that impacts the amount of mercury in the gypsum byproduct and possibly its stability during the wallboard process. The results of the Task 5 stack testing, as measured by the Ontario Hydro method, detected that an average of 51% of the incoming mercury in the FGD gypsum was emitted during wallboard production. These losses were distributed as 2% or less each across the wet gypsum dryer and product wallboard dryer, and about 50% across the gypsum calciner. Emissions were similar to what Task 3 results showed, on both a percentage and a mass basis, for gypsum produced by a power plant firing bituminous coal and also having gypsum fines blow down as part of the FGD dewatering scheme. As was seen in the Task 1 through 4 results, most of the mercury detected in the stack testing on the wet gypsum dryer and kettle calciner was in the form of elemental mercury. In the wallboard dryer kiln, a more signific

Jessica Marshall Sanderson

2006-06-01T23:59:59.000Z

26

Heat load of a P-doped GaAs photocathode in SRF electron gun  

Science Conference Proceedings (OSTI)

Many efforts were made over the last decades to develop a better polarized electron source for the high energy physics. Several laboratories operate DC guns with the Gallium-Arsenide photo-cathode, which yield a highly polarized electron beam. However, the beam's emittance might well be improved using a Superconducting RF electron gun, which delivers beams of higher brightness than DC guns does, because the field gradient at the cathode is higher. SRF guns with metal cathodes and CsTe cathodes have been tested successfully. To produce polarized electrons, a Gallium-Arsenide photo-cathode must be used: an experiment to do so in a superconducting RF gun is under way at BNL. Since the cathode will be normal conducting, the problem about the heat load stemming from the cathode arises. We present our measurements of the electrical resistance of GaAs at cryogenic temperatures, a prediction of the heat load and the verification by measuring the quality factor of the gun with and without cathode.

Wang, E.; Ben-Zvi, I.; Kewisch, J.; Burrill, A.; Rao, T.; Wu, Q.; Jain, A.; Gupta, R.; Holmes, D.

2010-05-23T23:59:59.000Z

27

Flue Gas Desulfurization Gypsum Agricultural Network: North Dakota Sites 1 and 2 (Wheat)  

Science Conference Proceedings (OSTI)

This report describes work performed in 2007 and 2008 to evaluate potential beneficial agricultural uses of flue gas desulfurization (FGD) gypsum at two sites in North Dakota. This work was part of a national research network evaluating beneficial uses of FGD gypsum in agriculture. The objectives of this research were to determine the influence of FGD gypsum applications on soil quality and on wheat (Triticum aestivum L.) yields and seed quality. Three application rates of FGD gypsum were compared with s...

2011-12-16T23:59:59.000Z

28

Time dependence of mechanical properties of specimens made from "grey gypsum"  

Science Conference Proceedings (OSTI)

The paper present monitoring of mechanical properties of grey calcined gypsum. The samples of dimension 40 × 40 × 160 mm were made from this material and put in laboratory conditions (relatively humidity 50 % and temperature 20 °C). Material ... Keywords: calcined gypsum, creep of gypsum, destructive methods, mechanical properties, shrinkage

P. Padev?t; P. Tesárek; T. Plachý

2010-11-01T23:59:59.000Z

29

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production  

Science Conference Proceedings (OSTI)

This report presents and discusses results from the project 'Fate of Mercury in Synthetic Gypsum Used for Wallboard Production', performed at five different full-scale commercial wallboard plants. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies involve the capture of mercury in FGD systems. The objective of this study has been to determine whether any mercury is released into the atmosphere at wallboard manufacturing plants when the synthetic gypsum material is used as a feedstock for wallboard production. The project has been co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope included seven discrete tasks, each including a test conducted at various USG wallboard plants using synthetic gypsum from different wet FGD systems. The project was originally composed of five tasks, which were to include (1) a base-case test, then variations representing differing power plant: (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5,could not be conducted as planned and instead was conducted at conditions similar to Task 3. Subsequently an opportunity arose to test gypsum produced from the Task 5 FGD system, but with an additive expected to impact the stability of mercury, so Task 6 was added to the project. Finally, Task 7 was added to evaluate synthetic gypsum produced at a power plant from an additional coal type. In the project, process stacks in the wallboard plant were sampled using the Ontario Hydro method. In every task, the stack locations sampled included a gypsum dryer and a gypsum calciner. In Tasks 1 and 4 through 7, the stack of the dryer for the wet wallboard product was also tested. Also at each site, in-stream process samples were collected and analyzed for mercury concentration before and after each significant step in wallboard production. These results and process data were used to construct mercury mass balances across the wallboard plants. The results from the project showed a wide range of percentage mercury losses from the synthetic gypsum feedstocks as measured by the Ontario Hydro method at the process stacks, ranging from 2% to 55% of the mercury in the gypsum feedstock. For the tasks exceeding 10% mercury loss across the wallboard plant, most of the loss occurred across the gypsum calciner. When total wallboard emissions remained below 10%, the primary emission location varied with a much less pronounced difference in emission between the gypsum dryer, calciner and board dryer. For all seven tasks, the majority of the mercury emissions were measured to be in the elemental form (Hg{sup 0}). Overall, the measured mercury loss mass rates ranged from 0.01 to 0.17 grams of mercury per dry ton of synthetic gypsum processed, or 0.01 to 0.4 pounds of mercury released per million square feet of wallboard produced from synthetic gypsum. The Coal Combustion Product Production and Use Survey from the American Coal Ash Association (ACAA) indicate that 7,579,187 short tons of synthetic gypsum were used for wallboard production in 2006. Extrapolating the results of this study to the ACAA industry usage rate, we estimate that mercury releases from wallboard production plants in 2006 ranged between 150 to 3000 pounds for the entire U.S. wallboard industry. With only seven sets of wallboard plant measurements, it is difficult to draw firm conclusions about what variables impact the mercury loss percentages across the wallboard plants. One significant o

Jessica Sanderson

2007-12-31T23:59:59.000Z

30

Flue Gas Desulfurization Scrubber Maintenance Guide: Gypsum Dewatering Area  

Science Conference Proceedings (OSTI)

Flue Gas Desulfurization Scrubber Maintenance Guide: Gypsum Dewatering Area provides fossil plant maintenance personnel with current maintenance information on this system. This report will assist the plant maintenance personnel in improving the reliability and reducing the maintenance costs for this area of their scrubber system.

2009-12-08T23:59:59.000Z

31

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production  

SciTech Connect

This report presents and discusses results from Task 6 of the study 'Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the atmosphere when the synthetic gypsum material is used as a feedstock for wallboard production. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope now includes six discrete tasks, each conducted at various USG wallboard plants using synthetic gypsum from different FGD systems. The project was originally composed of five tasks, which were to include (1) a baseline test, then variations representing differing power plant: (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5, which was to include testing with an alternate FGD reagent, could not be conducted as planned. Instead, Task 5 was conducted at conditions similar to Task 3, although with gypsum from an alternate FGD system. Subsequent to conducting Task 5 under these revised conditions, an opportunity arose to test gypsum produced at the same FGD system, but with an additive (Degussa Corporation's TMT-15) being used in the FGD system. TMT-15 was expected to impact the stability of mercury in synthetic gypsum used to produce wallboard, so Task 6 was added to the project to test this theory. In this project, process stacks in the wallboard plant have been sampled using the Ontario Hydro method. For every task, the stack locations sampled have included a dryer for the wet gypsum as it enters the plant and a gypsum calciner. For Tasks 1, 4, 5 and 6, the stack of the dryer for the wet wallboard product was also tested. Also at each site, in-stream process samples were collected and analyzed for mercury concentration before and after each significant step in wallboard production. The Ontario Hydro results, process sample mercury concentration data, and process data were used to construct mercury mass balances across the wallboard plants. Task 6 was conducted at a wallboard plant processing synthetic gypsum from a power plant that fires Eastern bituminous coal. The power plant has a single-loop, open spray tower limestone forced oxidation FGD system, with the forced oxidation conducted in the reaction tank integral with the FGD absorber. The FGD system has gypsum fines blow down as part of the dewatering step. The power plant is equipped with a selective catalytic reduction (SCR) system for NOX emissions control, and the SCR was in service during the time period the gypsum tested was produced. Also, as mentioned above, Degussa additive TMT-15 was being added to the FGD system when this gypsum was produced. The results of the Task 6 stack testing, as measured by the Ontario Hydro method, detected that an average of 55% of the incoming mercury was emitted during wallboard production. These losses were distributed as about 4% across the dryer mill, 6% across the board dryer kiln, and 45% across the kettle calciner. Emissions were similar to what Task 5 results showed on a percentage basis, but about 30% lower on a mass basis. The same power plant FGD system produced the synthetic gypsum used in Task 5 (with no use of TMT-15) and in Task 6 (with TMT-15 added to the FGD system). The lower emissions on a mass basis appeared

Jessica Sanderson; Gary M. Blythe; Mandi Richardson

2006-12-01T23:59:59.000Z

32

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production  

Science Conference Proceedings (OSTI)

This report presents and discusses results from Task 6 of the study 'Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the atmosphere when the synthetic gypsum material is used as a feedstock for wallboard production. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope now includes six discrete tasks, each conducted at various USG wallboard plants using synthetic gypsum from different FGD systems. The project was originally composed of five tasks, which were to include (1) a baseline test, then variations representing differing power plant: (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5, which was to include testing with an alternate FGD reagent, could not be conducted as planned. Instead, Task 5 was conducted at conditions similar to Task 3, although with gypsum from an alternate FGD system. Subsequent to conducting Task 5 under these revised conditions, an opportunity arose to test gypsum produced at the same FGD system, but with an additive (Degussa Corporation's TMT-15) being used in the FGD system. TMT-15 was expected to impact the stability of mercury in synthetic gypsum used to produce wallboard, so Task 6 was added to the project to test this theory. In this project, process stacks in the wallboard plant have been sampled using the Ontario Hydro method. For every task, the stack locations sampled have included a dryer for the wet gypsum as it enters the plant and a gypsum calciner. For Tasks 1, 4, 5 and 6, the stack of the dryer for the wet wallboard product was also tested. Also at each site, in-stream process samples were collected and analyzed for mercury concentration before and after each significant step in wallboard production. The Ontario Hydro results, process sample mercury concentration data, and process data were used to construct mercury mass balances across the wallboard plants. Task 6 was conducted at a wallboard plant processing synthetic gypsum from a power plant that fires Eastern bituminous coal. The power plant has a single-loop, open spray tower limestone forced oxidation FGD system, with the forced oxidation conducted in the reaction tank integral with the FGD absorber. The FGD system has gypsum fines blow down as part of the dewatering step. The power plant is equipped with a selective catalytic reduction (SCR) system for NOX emissions control, and the SCR was in service during the time period the gypsum tested was produced. Also, as mentioned above, Degussa additive TMT-15 was being added to the FGD system when this gypsum was produced. The results of the Task 6 stack testing, as measured by the Ontario Hydro method, detected that an average of 55% of the incoming mercury was emitted during wallboard production. These losses were distributed as about 4% across the dryer mill, 6% across the board dryer kiln, and 45% across the kettle calciner. Emissions were similar to what Task 5 results showed on a percentage basis, but about 30% lower on a mass basis. The same power plant FGD system produced the synthetic gypsum used in Task 5 (with no use of TMT-15) and in Task 6 (with TMT-15 added to the FGD system). The lower emissions on a mass basis appeared

Jessica Sanderson; Gary M. Blythe; Mandi Richardson

2006-12-01T23:59:59.000Z

33

J Sci Food Agric 1991, 57, 527-541 Dissolution of Various Sources of Gypsum in Aqueous  

E-Print Network (OSTI)

grade (AR), three sources of Jlue-gas desulphurisation (FGD) gypsum, phosphogypsum (PG),and mined gypsum, particle size, phosphogypsum, second order reaction. INTRODUCTION The beneficial effects of gypsum used as soil amendments: mined and industrial gypsum, the latter (phosphogypsum) being obtained mostly

Ahmad, Sajjad

34

First principles predictions of intrinsic defects in aluminum arsenide, AlAs : numerical supplement.  

SciTech Connect

This Report presents numerical tables summarizing properties of intrinsic defects in aluminum arsenide, AlAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz, 'First principles predictions of intrinsic defects in Aluminum Arsenide, AlAs', Materials Research Society Symposia Proceedings 1370 (2011; SAND2011-2436C), and intended for use as reference tables for a defect physics package in device models.

Schultz, Peter Andrew

2012-04-01T23:59:59.000Z

35

Flue Gas Desulfurization Gypsum Agricultural Network: Indiana Kingman Research Station (Corn and Soybeans)  

Science Conference Proceedings (OSTI)

Flue gas desulfurization gypsum (FGDG) is an excellent source of gypsum (CaSO4•2H2O) that is created when sulfur dioxide is removed from the exhaust gases during the combustion of coal for energy production. Research on FGDG has been conducted as part of the Flue Gas Desulfurization Gypsum Agricultural Network program sponsored by the Electric Power Research Institute in collaboration with individual utilities, the U.S. EPA, the United States Department of Agriculture’s Agricultural ...

2013-10-07T23:59:59.000Z

36

EFFECT OF GYPSUM ON AVAILABLE PHOSPHORUS EVALUATED BY MEHLICH-1, ION EXCHANGE RESIN, AND Pi-PAPER IN A BRAZILIAN TROPICAL OXISOL  

E-Print Network (OSTI)

Pure gypsum Source average Phosphate Rock (100 mg kg -1 P)Pure gypsum Source average Phosphate Rock (100 mg kg -1 P) bPure gypsum Source average Phosphate Rock (100 mg kg -1 P)

Silva, Rodrigo Coqui da; Chien, Sen Hsuing; Prochnow, Luís Ignácio

2009-01-01T23:59:59.000Z

37

Monolithic series-connected gallium arsenide converter development  

DOE Green Energy (OSTI)

We report the development of monolithic GaAs photovoltaic devices intended to convert light generated by a laser or other bright source to electricity. The converters described here can provide higher operating voltage than is possible using a single-junction converter, owing to use of a monolithic circuit that forms a planar series-connected string of single-junction sub-cells. This planar monolithic circuit is arranged to deliver the desired voltage and current during operation at the maximum power point. The paper describes two-, six-, and twelve-junction converters intended for illumination by a laser diode with a wavelength of 0.8 {mu}m. Design and characterization data are presented for optical power in the range of 100 mW to 1 W. The best conversion efficiency exceeds 50%. 9 refs., 4 figs., 2 tabs.

Spitzer, M.B.; McClelland, R.W.; Dingle, B.D.; Dingle, J.E.; Hill, D.S. (Kopin Corp., Taunton, MA (United States)); Rose, B.H. (Sandia National Labs., Albuquerque, NM (United States))

1991-01-01T23:59:59.000Z

38

Biological availability of nickel arsenides: toxic effects of particulate Ni/sub 5/As/sub 2/  

SciTech Connect

Considerations of (1) oil shale retort operating conditions, (2) oil shale elemental composition, (3) nickel and arsenic physico-chemical properties, and (4) oil shale matrix structure lead to the suggestion that nickel arsenides may be formed during the oil shale retorting process. The biological effects of nickel arsenides have not been previously studied. However, similarities between nickel subarsenide and nickel subsulfide and nickel subselenimide, both of which are known potent carcinogens, have caused concern that nickel arsenides may have adverse effects on biological systems. To determine if fugitive nickel arsenides from an oil shale retort could pose a threat to personnel in the workplace or to other living organisms in the environment, a program to study the toxicity of nickel arsenides has been initiated. Five stable nickel arsenides (Ni/sub 5/As/sub 2/, Ni/sub 2/As, Ni/sub 11/As/sub 8/, NiAs, and NiAs/sub 2/) and nickel arsenic sulfide (NiAsS) are considered possible species for study.

Gurley, L.R.; Tobey, R.A.; Valdez, J.G.; Halleck, M.S.; Barham, S.S.

1981-01-01T23:59:59.000Z

39

Evaluation of the Impact of Limestone on Gypsum Crystal Habit in Wet FGD Scrubbers  

Science Conference Proceedings (OSTI)

This document summarizes the results of a laboratory program focused on determining what key limestone components are responsible for impacting wet flue gas desulfurization (FGD) byproduct gypsum properties. Tests were conducted using several commercial limestone samples for which documented full-scale limestone forced oxidation wet FGD operating experience exists. These include limestone samples known to produce FGD gypsum with both ‘good’ and ‘poor’ crystallization ...

2012-12-28T23:59:59.000Z

40

GaAs photoconductive semiconductor switch  

DOE Patents (OSTI)

A high gain, optically triggered, photoconductive semiconductor switch (PCSS) implemented in GaAs as a reverse-biased pin structure with a passivation layer above the intrinsic GaAs substrate in the gap between the two electrodes of the device. The reverse-biased configuration in combination with the addition of the passivation layer greatly reduces surface current leakage that has been a problem for prior PCSS devices and enables employment of the much less expensive and more reliable DC charging systems instead of the pulsed charging systems that needed to be used with prior PCSS devices.

Loubriel, Guillermo M. (Sandia Park, NM); Baca, Albert G. (Albuquerque, NM); Zutavern, Fred J. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

NETL: Environmental Research - Fate of Mercury in Synthetic Gypsum Used for  

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

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production Fate of Mercury in Synthetic Gypsum Used for Wallboard Production This project will provide information about the fate of mercury in synthetic gypsum produced by wet FGD systems on coal-fired power plants, when used as feedstock for wallboard production. Wet FGD systems play a key role in current and future efforts to limit the air emissions of mercury control from coal-fired plants. Potential emissions of mercury from FGD byproduct gypsum during wallboard production could limit overall mercury control levels achieved by the coal power industry. Furthermore, any adverse effects of elevated mercury levels in wallboard products could undermine the use of FGD gypsum as a feedstock for wallboard plants. Under a Cooperative Agreement with DOE-NETL, USG Corp., a major producer of wallboard, will provide high-quality data on the extent and location of mercury release during the wallboard production process, and provide additional information on the potential for mercury leaching at the end of the wallboard life cycle, when it is disposed in municipal landfills.

42

Thin film gallium arsenide solar cell research. Third quarterly project report, September 1, 1980-November 30, 1980. [Antireflection coating  

DOE Green Energy (OSTI)

The major objective of this contract is to produce gallium arsenide solar cells of 10% conversion efficiency in films of less than 10 micrometers thick which have been deposited by chemical vapor deposition on graphite or tungsten coated graphite substrates. Major efforts during this quarter were directed to: (1) the optimization of the deposition of gallium arsenide films of 10 ..mu..m thickness or less on tungsten/graphic substrates, (2) the investigation of the effectiveness of various grain boundary passivation techniques, (3) the deposition of tantalum pentoxide by ion beam sputtering as an antireflection coating, (4) the deposition of gallium aluminium arsenide by the organometallic process, and (5) the fabrication and characterization of large area Schottky barrier type solar cells from gallium arsenide films of about 10 ..mu..m thickness. Various grain boundary passivation techniques, such as the anodic oxidation, thermal oxidation, and ruthenium treatment, have been investigated. The combination of thermal oxidation and ruthenium treatment has been used to fabricate Schottky barrier type solar cells. Large area MOS solar cells of 9 cm/sup 2/ area with AMl efficiency of 8.5% have been fabricated from ruthenium treated gallium arsenide films of 10 ..mu..m thickness. The construction of the apparatus for the deposition of gallium aluminum arsenide by the organometallic process has been completed. The deposition of good quality tantalum pentoxide film as an antireflection coating has been carried out by the ion beam sputtering technique. The short-circuit current density and AMl efficiency of the solar cells are increased by approximately 60%, with a slight increase in the open-circuit voltage. Details are presented. (WHK)

Chu, S. S.

1980-12-01T23:59:59.000Z

43

Flue Gas Desulfurization Gypsum Agricultural Network: Wisconsin Arlington Research Station Fields 295 and 27 (Alfalfa)  

Science Conference Proceedings (OSTI)

This report describes field research in Wisconsin as part of the Flue Gas Desulfurization Gypsum (FGDG) Agricultural Network. The objective of this study, conducted during 2009-2010, was to evaluate potential beneficial agricultural uses of FGDG as a soil amendment to improve alfalfa production. FGDG was compared to a commercially available gypsum product (C-GYP) widely sold in the U.S. Midwest and other areas. A study was established in two fields (Field 295 in 2009/2010 and Field 27 in 2010) at ...

2013-05-06T23:59:59.000Z

44

Flue Gas Desulfurization Gypsum Agricultural Network: North Dakota Sites 3, 4, and 5 (Canola)  

Science Conference Proceedings (OSTI)

Flue gas desulfurization gypsum (FGDG) is a very pure form of gypsum that is a by-product from the combustion of coal for energy production. This report describes 2008-2009 work to evaluate potential beneficial agricultural uses of FGDG at three sites near Langdon, North Dakota. This work was part of a national research network evaluating beneficial uses of FGDG in agriculture, in this case, fertilization of dryland canola by FGDG. The objectives of this research were to 1) determine the influence of FGD...

2011-11-28T23:59:59.000Z

45

Flue Gas Desulfurization Gypsum Agricultural Network: Ohio Sites 1 (Mixed Hay) and 2 (Corn)  

Science Conference Proceedings (OSTI)

The objectives of this work conducted during 2008–2010 were to evaluate potential beneficial agricultural uses of flue gas desulphurization gypsum (FGDG) in eastern Ohio and to assess the potential for environmental effects of the use of FGDG. Two field experiments were conducted at the eastern Ohio research site, one involving a mixed-grass hay field and the other a corn (Zea mays L.) field. FGDG and mined gypsum product were applied one time at rates of 0.2, 2.0, and 20 megagrams ...

2012-09-17T23:59:59.000Z

46

Manufacture of ammonium sulfate fertilizer from FGD-gypsum. Technical report, March 1--May 31, 1995  

Science Conference Proceedings (OSTI)

Goal is to assess technical and economic feasibility for producing fertilizer-grade ammonium sulfate from gypsum produced in limestone flue gas desulfurization (FGD). This is the 1st year of a 2-year program among Illinois State Geological Survey, University of Illinois (Urbana-Champaign), Allied-Signal, Marketing Chem. Process Inc., Henry Fertilizer, Illinois Power Co., and Central Illinois Public Services. In previous quarter, chemistry and process conditions were reviewed and a reactor system set up and used to conduct laboratory tests. FGD-gypsum from Abbott power plant was used. The scrubber, a Chiyoda Thoroughbred 121 FGD, produced a filter cake (98.36% gypsum and < 0.01% CaSO{sub 3}). Conversion of FGD- gypsum to ammonium sulfate was tested at 60-70{degree}C for 5-6 hr. Yield up to 82% and purity up to 95% were achieved for the ammonium sulfate production. During this quarter, more bench-scale experiments including a mass balance analysis were conducted; a yield up to 83% and up to 99% purity were achieved. A literature survey was completed and a preliminary process flow sheet was developed. Economics of the process is being estimated.

Chou, M.I.M.; Rostam-Abadi, Ml; Lytle, J.M.; Bruinius, J.A.; Li, Y.C. [Illinois State Geological Survey, Urbana, IL (United States); Hoeft, R. [Illinois Univ., Urbana, IL (United States); Dewey, S. [AlliedSignal-Chemicals (United States); Achorn, F. [Southeast Marketing Chem. Process INc. (SE-ME) (United States)

1995-12-31T23:59:59.000Z

47

Flue Gas Desulfurization Scrubber Maintenance Guide: Wastewater Treatment and Gypsum Handling Area  

Science Conference Proceedings (OSTI)

The Flue Gas Desulfurization Scrubber Maintenance Guide: Wastewater Treatment and Gypsum Handling Area provides fossil plant maintenance personnel with current maintenance information on these systems. This guide will assist plant maintenance personnel in improving the reliability and reducing the maintenance costs for these areas of their scrubber system.

2009-12-23T23:59:59.000Z

48

Dynamics of formation of photoresponse in a detector structure made of gallium arsenide  

SciTech Connect

The influence of capture effects on the characteristics of detectors of the ionizing radiation based on semi-insulating gallium arsenide is considered. Generation of nonequilibrium electrons and holes along the entire thickness of the active region was performed under illumination with an infrared light-emitting diode with a wavelength of 0.9 {mu}m. In this case, the situation emerging in the device structure under the effect of X-ray radiation or a high-energy electron beam was simulated. It is shown that the variation in the shape of the output signal with time in this case is caused by variation in the electric field profile due to the capture of holes at deep centers in gallium arsenide. An absolutely different distribution of the electric field emerges in the structure under irradiation of a semitransparent cathode of the structure with a red light-emitting diode, emission of which penetrates into the active region for mere 1 {mu}m. In this case, the transformation of the electric field is caused by the capture of electrons. Under the prolonged effect of such radiation, a space-charge-limited current mode emerges in the device.

Ayzenshtat, G. I., E-mail: ayzen@mail.tomsknet.ru; Lelekov, M. A.; Tolbanov, O. P. [Tomsk State University (Russian Federation)

2008-04-15T23:59:59.000Z

49

Gypsum treated fly ash as a liner for waste disposal facilities  

SciTech Connect

Fly ash has potential application in the construction of base liners for waste containment facilities. While most of the fly ashes improve in the strength with curing, the ranges of permeabilities they attain may often not meet the basic requirement of a liner material. An attempt has been made in the present context to reduce the hydraulic conductivity by adding lime content up to 10% to two selected samples of class F fly ashes. The use of gypsum, which is known to accelerate the unconfined compressive strength by increasing the lime reactivity, has been investigated in further improving the hydraulic conductivity. Hydraulic conductivities of the compacted specimens have been determined in the laboratory using the falling head method. It has been observed that the addition of gypsum reduces the hydraulic conductivity of the lime treated fly ashes. The reduction in the hydraulic conductivity of the samples containing gypsum is significantly more for samples with high amounts of lime contents (as high as 1000 times) than those fly ashes with lower amounts of lime. However there is a relatively more increase in the strengths of the samples with the inclusion of gypsum to the fly ashes at lower lime contents. This is due to the fact that excess lime added to fly ash is not effectively converted into pozzolanic compounds. Even the presence of gypsum is observed not to activate these reactions with excess lime. On the other hand the higher amount of lime in the presence of sulphate is observed to produce more cementitious compounds which block the pores in the fly ash. The consequent reduction in the hydraulic conductivity of fly ash would be beneficial in reducing the leachability of trace elements present in the fly ash when used as a base liner.

Sivapullaiah, Puvvadi V., E-mail: siva@civil.iisc.ernet.in [Department of Civil Engineering, Indian Institute of Science, Bangalore 560012 (India); Baig, M. Arif Ali, E-mail: reach2arif@gmail.com [Department of Civil Engineering, Indian Institute of Science, Bangalore 560012 (India)

2011-02-15T23:59:59.000Z

50

Gallium arsenide thin films on tungsten/graphite substrates. Phase II. Quarterly project report No. 2, December 1, 1977-February 28, 1978  

DOE Green Energy (OSTI)

The objectives of this contract are to investigate thin films of gallium arsenide on tungsten/graphite substrates and to prepare solar cells with an AM1 efficiency of 6% or higher by August 1978. Efforts during this quarter have been directed to: (1) the deposition and characterization of gallium arsenide films on tungsten/graphite substrates by the arsenic and arsine processes, (2) the construction and operation of an apparatus for the deposition of titanium dioxide films, and (3) the fabrication and evaluation of MOS solar cells on tungsten/graphite substrates. Gallium arsenide films have been deposited on tungsten/graphite substrates by the reaction of gallium, hydrogen chloride, and arsenic in a hydrogen flow. The structural and electrical properties of these films are very similar to those obtained by the arsine process. The initial stage of the deposition of gallium arsenide films on tungsten/graphite substrates has been investigated by the scanning electron microscopy.

Chu, S.S.

1978-03-01T23:59:59.000Z

51

Selective growth experiments on gallium arsenide (100) surfaces patterned using UV-nanoimprint lithography  

Science Conference Proceedings (OSTI)

We describe a nanoimprint lithography (NIL) process and subsequent solid-source molecular beam epitaxy (SSMBE) growth of III-V semiconductors on patterned substrates. In particular, growth of GaAs, GaInAs, and GaInP, and effects of growth temperature ... Keywords: Molecular beam epitaxy, Nanoimprint lithography, Patterned substrates, Selective growth

A. Tukiainen; J. Viheriälä; T. Niemi; T. Rytkönen; J. Kontio; M. Pessa

2006-12-01T23:59:59.000Z

52

Energy-saving cements obtained from chemical gypsum and other industrial wastes  

SciTech Connect

The main sources, properties and uses of chemical gypsum are reviewed and the possibility of its utilization for the manufacturing process of calcium sulfoaluminate cements is explored. In this process other industrial wastes, as sources of reactive silica and alumina, can be employed. Phosphogypsum, blast-furnace slag and fly ash were the main by-products investigated. The principal properties of calcium sulfoaluminate cements, such as synthesis, hydration and strength, were discussed. Some durability problems and suggested solutions were particularly emphasized.

Beretka, J. [CSIRO Div. of Building, Construction and Engineering, Highett, Victoria (Australia)] [CSIRO Div. of Building, Construction and Engineering, Highett, Victoria (Australia); Cioffi, R. [Univ. Degli Studi di Napoli Federico II (Italy). Dipt. di Ingegneria dei Materiali e della Produzione] [Univ. Degli Studi di Napoli Federico II (Italy). Dipt. di Ingegneria dei Materiali e della Produzione; Marroccoli, M.; Valenti, G.L. [Univ. della Basilicata, Potenza (Italy). Dipt. di Ingegneria e Fisica dell`Ambiente] [Univ. della Basilicata, Potenza (Italy). Dipt. di Ingegneria e Fisica dell`Ambiente

1996-12-31T23:59:59.000Z

53

In-Plane Electronic Anisotropy of Underdoped ___122___ Fe-Arsenide Superconductors Revealed by Measurements of Detwinned Single Crystals  

SciTech Connect

The parent phases of the Fe-arsenide superconductors harbor an antiferromagnetic ground state. Significantly, the Neel transition is either preceded or accompanied by a structural transition that breaks the four fold symmetry of the high-temperature lattice. Borrowing language from the field of soft condensed matter physics, this broken discrete rotational symmetry is widely referred to as an Ising nematic phase transition. Understanding the origin of this effect is a key component of a complete theoretical description of the occurrence of superconductivity in this family of compounds, motivating both theoretical and experimental investigation of the nematic transition and the associated in-plane anisotropy. Here we review recent experimental progress in determining the intrinsic in-plane electronic anisotropy as revealed by resistivity, reflectivity and ARPES measurements of detwinned single crystals of underdoped Fe arsenide superconductors in the '122' family of compounds.

Fisher, Ian Randal

2012-05-08T23:59:59.000Z

54

Atomic hydrogen cleaning of polarized GaAs photocathodes  

DOE Green Energy (OSTI)

Atomic hydrogen cleaning followed by heat cleaning at 450 C was used to prepare negative-electron-affinity GaAs photocathodes. When hydrogen ions were eliminated, quantum efficiencies of 15% were obtained for bulk GaAs cathodes, higher than the results obtained using conventional 600 C heat cleaning. The low-temperature cleaning technique was successfully applied to thin, strained GaAs cathodes used for producing highly polarized electrons. No depolarization was observed even when the optimum cleaning time of about 30 seconds was extended by a factor of 100.

Maruyama, Takashi

2003-04-03T23:59:59.000Z

55

Preparation of GaAs photocathodes at low temperature  

SciTech Connect

The preparation of an atomically clean surface is a necessary step in the formation of negative electron affinity (NEA) GaAs. Traditional methods to this end include cleaving, heat cleaning and epitaxial growth. Cleaving has the advantage of yielding a fresh surface after each cleave, but is limited to small areas and is not suitable for specialized structures. Heat cleaning is both simple and highly successful, so it is used as a preparation method in virtually all laboratories employing a NEA source on a regular basis. Due to its high cost and complexity, epitaxial growth of GaAs with subsequent in vacuo transfer is not a practical solution for most end users of GaAs as a NEA electron source. While simple, the heating cleaning process has a number of disadvantages. Here, a variety of cleaning techniques related to preparation of an atomically clean GaAs surface without heating to 600 C are discussed and evaluated.

Mulhollan, G.; Clendenin, J.; Tang, H.

1996-10-01T23:59:59.000Z

56

GaAs Films Prepared by RF-Magnetron Sputtering  

DOE Green Energy (OSTI)

The authors reported on the optical absorption, adhesion, and microstructure of RF-magnetron sputtered films of hydrogenated amorphous and microcrystalline GaAs films for the 1 to 25 {micro}m infrared wavelength rate. Sputtering parameters which were varied include sputtering power, temperature and pressure, and hydrogen sputtering-gas concentration. TEM results show a sharp transition from purely amorphous GaAs to a mixture of microcrystalline GaAs in an amorphous matrix at 34 {+-} 2 C. By optimizing the sputtering parameters, the optical absorption coefficient can be decreased below 100 cm{sup -1} for wavelengths greater than about 1.25 {micro}m. These results represent the lowest reported values of optical absorption for sputtered films of GaAs directly measured by spectrophotometry for the near-infrared wavelength region.

L.H. Ouyang; D.L. Rode; T. Zulkifli; B. Abraham-Shrauner; N. Lewis; M.R. Freeman

2001-08-01T23:59:59.000Z

57

GyPSuM: A Detailed Tomographic Model of Mantle Density and Seismic Wave Speeds  

SciTech Connect

GyPSuM is a tomographic model fo mantle seismic shear wave (S) speeds, compressional wave (P) speeds and detailed density anomalies that drive mantle flow. the model is developed through simultaneous inversion of seismic body wave travel times (P and S) and geodynamic observations while considering realistic mineral physics parameters linking the relative behavior of mantle properties (wave speeds and density). Geodynamic observations include the (up to degree 16) global free-air gravity field, divergence of the tectonic plates, dynamic topography of the free surface, and the flow-induced excess ellipticity of the core-mantle boundary. GyPSuM is built with the philosophy that heterogeneity that most closely resembles thermal variations is the simplest possible solution. Models of the density field from Earth's free oscillations have provided great insight into the density configuration of the mantle; but are limited to very long-wavelength solutions. Alternatively, simply scaling higher resolution seismic images to density anomalies generates density fields that do not satisfy geodynamic observations. The current study provides detailed density structures in the mantle while directly satisfying geodynamic observations through a joint seismic-geodynamic inversion process. Notable density field observations include high-density piles at the base of the superplume structures, supporting the fundamental results of past normal mode studies. However, these features are more localized and lower amplitude than past studies would suggest. When we consider all seismic anomalies in GyPSuM, we find that P and S-wave speeds are strongly correlated throughout the mantle. However, correlations between the high-velocity S zones in the deep mantle ({approx} 2000 km depth) and corresponding P-wave anomalies are very low suggesting a systematic divergence from simplified thermal effects in ancient subducted slab anomalies. Nevertheless, they argue that temperature variations are the primary cause of P-wave, S-wave, and density anomalies in the mantle.

Simmons, N A; Forte, A M; Boschi, L; Grand, S P

2010-03-30T23:59:59.000Z

58

Elimination of charge-enhancement effects in GaAs FETs with a low-temperature grown GaAs buffer layer  

Science Conference Proceedings (OSTI)

The use of low temperature grown GaAs (LT GaAs) buffer layer in GaAs FETs is shown via computer simulation and experimental measurement to reduce ion-induced charge collection by two to three orders of magnitude. This reduction in collected charge is associated with the efficient reduction of charge-enhancement mechanisms in the FETs. Error rate calculations indicate that the soft error rate of LT GaAs integrated circuits will be reduced by several orders of magnitude when compared to conventional FET-based GaAs ICs.

McMorrow, D.; Weatherford, T.R.; Curtice, W.R.; Knudson, A.R.; Buchner, S.; Melinger, J.S.; Tran, L.H.; Campbell, A.B. [Naval Research Lab., Washington, DC (United States)

1995-12-01T23:59:59.000Z

59

Boron arsenide thin film solar cell development. Quarterly report No. 1  

DOE Green Energy (OSTI)

A large portion of the effort expended in the first quarter was devoted to the design, assembly, and testing of the film growth apparatus. The reactor has been completed and tested by depositing boron from diborane gas onto heated quartz substrates. The objective of this effort was to achieve film growth, which has been accomplished. Within the last month, attempts to grow boron arsenide films have been made by introducing both diborane and arsine into the reactor. Thin films have been grown on quartz and sapphire (alumina) substrates. Variations in film thickness, composition, degree of crystallinity, and conductivity have been observed as a result of variation of the deposition parameters, such as type and flow rate of carrier gases, substrate temperature, and substrate materials. X-ray analysis of several samples indicates that films containing boron and arsenic have been grown. No crystalline films have been produced to date. Electrical and optical measurements indicate some correlation between at least one of the films grown and the results achieved by Chu, et al. on BAs. Thus far, the electrical conductivity, film topography, optical absorption, index of refraction, impurity type, and photo-conductivity have been investigated on one sample. This material appears to be B/sub x/As/sub y/ and could be BAs. Further investigations will be required to be conclusive.

Boone, J.L.; Van Doren, T.P.

1979-07-01T23:59:59.000Z

60

The use of gypsum and a coal desulfurization by-product to ameliorate subsoil acidity for alfalfa growth  

E-Print Network (OSTI)

Acid soils limit the growth of aluminum-(Al) sensitive crops such as alfalfa (Medicago sativa L.). Management of acid subsoils can be difficult due to physical and economic constraints. Field experiments were conducted at two locations to evaluate the effectiveness of surface-applied gypsum and a flue gas desulfurization by-product for reducing the toxic effects of acid subsoils on alfalfa. The materials were applied at rates of 0, 5, 10, and 15 Mg ha-1. In addition, a glasshouse experiment was conducted that used 0, 5, and 10 Mg ha-1 of gypsum only. Field studies were concluded 41 and 45 months after treatment application at the two locations. No effect of material on alfalfa yield or tissue mineral concentration was observed. Also, rate did not affect yield. However, there were differences in plant tissue mineral concentration in several harvests that were related to rate. Soil was sampled periodically to 120 cm and indicated movement of Ca and S into the soil profile to depths of 60 and 120 cm, respectively. Subsoil pHH2O and pHCaCl2 were not affected by treatment. Extractable and exchangeable Al were not reduced by movement of Ca and S into the soil. In the glasshouse study, alfalfa yields and root growth were not affected by gypsum rate. As gypsum rate increased, plant tissue S increased, but K and Mg decreased. Alfalfa roots did not grow below 60 cm, even though there was indication of material movement to 90 cm in the soil. Although sulfur moved to 75 cm, no effect on soil Al was observed. Leachate collected from the bottoms of columns indicated that soil cations were leached as a result of gypsum application. Gypsum and the flue gas desulfurization by-product did not significantly affect the acid soils used in these studies or improve alfalfa growth.

Chessman, Dennis John

2003-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

AN INNOVATIVE INTEGRATED APPROACH TO MINIMIZING GYPSUM AND PYRITE WASTES BY CONVERSION TO MARKETABLE PRODUCTS  

Science Conference Proceedings (OSTI)

The objective of this research program is to develop a novel integrated process to eliminate millions of tons of gypsum and pyrite wastes generated annually by the U.S. energy industries and reduce the emission of millions of tons of greenhouse gas carbon dioxide. This was accomplished by converting gypsum and pyrite wastes to marketable products such as lime, direct reduced iron (DRI), and sulfur products and obviating the need to calcine millions of tons of limestone for use in utility scrubbers. Specific objectives included: (1) Develop a novel, integrated process for utilizing two major wastes generated by mining and energy industries to produce lime for recycling and other marketable products. (2) Study individual chemical reactions involved in pyrite decomposition, DRI production, and Muller-Kuhne process for lime regeneration to determine optimum process variables such as temperature, time, and reactant composition. (3) Investigate techniques for effective concentration of pyrite from tailing waste and methods for effective separation of DRI from calcium sulfide.

Daniel Tao

2000-06-27T23:59:59.000Z

62

Potential Agricultural Uses of Flue Gas Desulfurization Gypsum in the Northern Great Plains  

Science Conference Proceedings (OSTI)

Flue gas desulfurization gypsum (FGDG) is a byproduct from the combustion of coal for electrical energy production. Currently, FGDG is being produced by 15 electrical generating stations in Alabama, Florida, Indiana, Iowa, Kentucky, Ohio, North Carolina, South Carolina, Tennessee, Texas, and Wisconsin. Much of this byproduct is used in the manufacturing of wallboard. The National Network for Use of FGDG in Agriculture was initiated to explore alternative uses of this byproduct. In the northern Great Plains (North Dakota, South Dakota, and Montana), FGDG has the potential to be used as a Ca or S fertilizer, as an acid soil ameliorant, and for reclaiming or mitigating sodium-affected soils. Greater than 1.4 million Mg of FGDG could initially be used in these states for these purposes. Flue gas desulfurization gypsum can be an agriculturally important resource for helping to increase the usefulness of problem soils and to increase crop and rangeland production. Conducting beneficial use audits would increase the public awareness of this product and help identify to coal combustion electrical generating stations the agriculturally beneficial outlets for this byproduct.

DeSutter, T.M.; Cihacek, L.J. [North Dakota State University, Fargo, ND (United States). Department of Soil Science

2009-07-15T23:59:59.000Z

63

Gallium arsenide-based ternary compounds and multi-band-gap solar cell research  

DOE Green Energy (OSTI)

Aim of this contract is the achievement of a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed is metalorganic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or may contain a p-n junction of its own and form the bottom cell of a two junction tandem solar cell structure. The III-V material for the single-junction case is GaAs and for the two-junction case is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include the following: (1) a 17.6% efficient GaAs-on-Si solar cell; (2) an 18.5% efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8% efficient GaAs-on-GaAs solar cell; (4) a 28.7% efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

Vernon, S. (Spire Corp., Bedford, MA (United States))

1993-02-01T23:59:59.000Z

64

Active devices for high temperature microcircuitry. [Silicon and gallium arsenide devices  

DOE Green Energy (OSTI)

As part of a program to develop high temperature electronics for geothermal well instrumentation, a number of solid state diode and transistor types were characterized from room temperature to 300/sup 0/C. The temperature dependence and aging stability of transport and leakage properties were measured. Included in the study were silicon diodes, bipolar transistors, JFETs, MOSFETs, and GaAs MESFETs and JFETs. In summary the results are: diodes and bipolar transistors became extremely leaky at high temperature and are therefore of limited use; silicon MOSFETs and GaAs devices showed unacceptable aging instabilities at high temperatures; silicon JFETs from certain manufacturers were sufficiently stable and had suitable temperature dependent characteristics so that operational circuits could be made. Comparisons were made of experimental device characteristics and those predicted by theory. The theoretical calculations were done using standard equations revised to include appropriate temperature dependent parameters. Close agreement between theory and experiment was found, indicating that unexpected high temperature effects were insignificant. In order to facilitate the use of devices in high temperature hybrids, it was necessary to develop bonding and prescreening techniques. A large variance of JFET 300/sup 0/C operating parameters was found even within a single production lot. Consequently, high temperature prescreening allowed each circuit to be specifically ''pretuned.'' Standard solder, epoxy, and chip and wire attachment technologies were not functional at 300/sup 0/C. Gold-germanium solder, aluminum wire to DuPont 9910 gold film, and diffusion barrier pads were developed to allow high temperature attachment.

Palmer, D.W.; Draper, B.L.; McBrayer, J.D.; White, K.R.

1978-02-01T23:59:59.000Z

65

Epitaxial EuO thin films on GaAs  

SciTech Connect

We demonstrate the epitaxial growth of EuO on GaAs by reactive molecular beam epitaxy. Thin films are grown in an adsorption-controlled regime with the aid of an MgO diffusion barrier. Despite the large lattice mismatch, it is shown that EuO grows well on MgO(001) with excellent magnetic properties. Epitaxy on GaAs is cube-on-cube and longitudinal magneto-optic Kerr effect measurements demonstrate a large Kerr rotation of 0.57 deg., a significant remanent magnetization, and a Curie temperature of 69 K.

Swartz, A. G.; Ciraldo, J.; Wong, J. J. I.; Li Yan; Han Wei; Lin Tao; Shi, J.; Kawakami, R. K. [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States); Mack, S.; Awschalom, D. D. [Center for Spintronics and Quantum Computation, University of California, Santa Barbara, California 93106 (United States)

2010-09-13T23:59:59.000Z

66

An experiment to test the viability of a gallium-arsenide cathode in a SRF electron gun  

SciTech Connect

Strained gallium arsenide cathodes are used in electron guns for the production of polarized electrons. In order to have a sufficient quantum efficiency lifetime of the cathode the vacuum in the gun must be 10{sup -11} Torr or better, so that the cathode is not destroyed by ion back bombardment or through contamination with residual gases. All successful polarized guns are DC guns, because such vacuum levels can not be obtained in normal conducting RF guns. A superconductive RF gun may provide a sufficient vacuum level due to cryo-pumping of the cavity walls. We report on the progress of our experiment to test such a gun with normal GaAs-Cs crystals.

Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Wu, Q.; Todd, R.; Wang, E.; Bluem, H.; Holmes, D.; Schultheiss, T.

2009-05-04T23:59:59.000Z

67

A GaAs transceiver chip for optical data transmission  

SciTech Connect

The present article describes a transceiver VLSI chip for optical data transmission, at 1 Gbit/s (1.4 Gbit/s in selected production), made in GaAs technology. The transceiver makes the parallel-to-serial and serial-to-parallel conversion as well as the encoding and decoding of 32 bit data words. The circuit operates in a completely asynchronous mode, allowing the possibility of switching on-off the transmission in few nsec and of using the transceiver not only in point-to-point topologies, but also in flooding topologies (i.e. star connections). The radiation hardness and the relatively low power consumption, respect to TTL, of the GaAs, extend the use of the chip to a large number of applications in present and future high energy physics experimental apparatus.

Mirabelli, G.; Petrolo, E.; Valente, E. (Ist. Nazionale di Fisica Nucleare, Roma (Italy)); Cardarelli, R.; Santonico, R. (Sezione di Roma 2 and Univ. di Roma (Italy). Ist. Nazionale di Fisica Nucleare); Ferrer, M.L. (Lab. Nazionali di Frascati (Italy). Ist. Nazionale di Fisica Nucleare)

1993-08-01T23:59:59.000Z

68

SEU design consideration for MESFETs on LT GaAs  

SciTech Connect

Computer simulation results are reported on transistor design and single-event charge collection modeling of metal-semiconductor field effect transistors (MESFETs) fabricated in the Vitesse H-GaAsIII{reg_sign} process on Low Temperature grown (LT) GaAs epitaxial layers. Tradeoffs in Single Event Upset (SEU) immunity and transistor design are discussed. Effects due to active loads and diffusion barriers are examined.

Weatherford, T.R.; Radice, R.; Eskins, D. [Naval Postgraduate School, Monterey, CA (United States)] [and others

1997-12-01T23:59:59.000Z

69

Direct measurement of interfacial structure in epitaxial Gd2O3 on GaAs (001) using scanning tunneling microscopy  

Science Conference Proceedings (OSTI)

The epitaxial growth of Gd"2O"3 on GaAs (001) has given a low interfacial density of states, resulting in the demonstration of the first inversion-channel GaAs metal-oxide-semiconductor field-effect transistor. Motivated by the significance of this discovery, ... Keywords: Electronic information, GaAs, Gd2O3, Interfacial stacking, Scanning tunneling microscopy

Y. P. Chiu; M. C. Shih; B. C. Huang; J. Y. Shen; M. L. Huang; W. C. Lee; P. Chang; T. H. Chiang; M. Hong; J. Kwo

2011-07-01T23:59:59.000Z

70

Universal Heat Conduction in the Iron Arsenide Superconductor KFe2As2: Evidence of a d-Wave State  

SciTech Connect

The thermal conductivity ? of the iron arsenide superconductor KFe2As2 was measured down to 50 mK for a heat current parallel and perpendicular to the tetragonal c axis. A residual linear term at T?0, ?0/T is observed for both current directions, confirming the presence of nodes in the superconducting gap. Our value of ?0/T in the plane is equal to that reported by Dong et al. [ Phys. Rev. Lett. 104 087005 (2010)] for a sample whose residual resistivity ?0 was 10 times larger. This independence of ?0/T on impurity scattering is the signature of universal heat transport, a property of superconducting states with symmetry-imposed line nodes. This argues against an s-wave state with accidental nodes. It favors instead a d-wave state, an assignment consistent with five additional properties: the magnitude of the critical scattering rate ?c for suppressing Tc to zero; the magnitude of ?0/T, and its dependence on current direction and on magnetic field; the temperature dependence of ?(T).

Reid, J.-Ph.; Tanatar, Makariy A.; Juneau-Fecteau, A.; Gordon, R.T.; Rene de Cotret, S.; Doiron-Leyraud, N.; Saito, T.; Fukazawa, H.; Kohori, Y.; Kihou, K.; Lee, C.H.; Iyo, A.; Eisaki, H.; Prozorov, Ruslan; Taillefer, Louis

2012-08-21T23:59:59.000Z

71

Single-Crystalline Thin Film Used in Photovoltaics  

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

Single-crystalline thin films are made from gallium arsenide (GaAs), a compound semiconductor that is a mixture of gallium and arsenic.

72

Terahertz waveguide spectroscopy of two-dimensional plasmons in GaAs  

E-Print Network (OSTI)

The electrical characteristics of high-mobility, two-dimensional electron gas (2DEG) systems, such as GaAs quantum wells, have been well-studied at low frequencies and in extreme conditions of high magnetic fields and ...

Harris, C. Thomas (Charles Thomas)

2010-01-01T23:59:59.000Z

73

Thin films of gallium arsenide on low-cost substrates. Quarterly technical progress report No. 8 and topical report No. 3, April 2-July 1, 1978  

DOE Green Energy (OSTI)

The seventh quarter of work on the contract is summarized. The metalorganic chemical vapor deposition (MO-CVD) technique has been applied to the growth of thin films of GaAs and GaAlAs on inexpensive polycrystalline or amorphous substrate materials (primarily glasses and metals) for use in fabrication of large-area low-cost photovoltaic device structures. Trimethylgallium (TMG), arsine (AsH/sub 3/), and trimethylaluminum (TMAl) are mixed in appropriate concentrations at room temperature in the gaseous state and pyrolyzed at the substrate, which is heated in a vertical reactor chamber to temperatures of 725 to 750/sup 0/C, to produce the desired film composition and properties. The technical activities during the quarter were concentrated on (1) a continuing evaluation of various graphite materials as possible substrates for MO-CVD growith of the polycrystalline GaAs solar cells; (2) attempts to improve the quality (especially the grain size) of polycrystalline GaAs films on Mo sheet and Mo/glass substrates by using HCl vapor during the MO-CVD growith process; (3) further studies of the transport properties of polycrystalline GaAs films, wth emphasis on n-type films; (4) continuing investigations of the properties of p-n junctions in polycrystalline GaAs, with emphasis on the formation and properties of p/sup +//n/n/sup +/ deposited structures; and (5) assembling apparatus and establishing a suitable technique for producing TiO/sub 2/ layers for use as AR coatings on GaAs cells. Progress is reported. (WHK)

Ruth, R.P.; Dapkus, P.D.; Dupuis, R.D.; Johnson, R.E.; Manasevit, H.M.; Moudy, L.A.; Yang, J.J.; Yingling, R.D.

1978-07-01T23:59:59.000Z

74

Single-event phenomena in GaAs devices and circuits  

Science Conference Proceedings (OSTI)

The single-event upset (SEU) characteristics of GaAs devices and circuits are reviewed. GaAs FET-based integrated circuits (IC`s) are susceptible to upsets from both cosmic-ray heavy ions and protons trapped in the Earth`s radiation belts. The origin of the SEU sensitivity of GaAs IC`s is discussed in terms of both device-level and circuit-level considerations. At the device level, efficient charge-enhancement mechanisms through which more charge can be collected than is deposited by the ion have a significant negative impact on the SEU characteristics of GaAs IC`s. At the circuit level, different GaAs digital logic topologies exhibit different levels of sensitivity to SEU because of variations in parameters, including logic levels, capacitances, and the degree of gate or peripheral isolation. The operational and SEU characteristics of several different GaAs logic families are discussed. Recent advances in materials and processing that provide possible solutions to the SEU problem are addressed.

McMorrow, D.; Melinger, J.S.; Campbell, A.B. III; Weatherford, T.R. [Naval Research Lab., Washington, DC (United States); Buchner, S.; Knudson, A.R.; Tran, L.H. [SFA Inc., Landover, MD (United States)

1996-04-01T23:59:59.000Z

75

Heavy ion SEU immunity of a GaAs complementary HIGFET circuit fabricated on a low temperature grown buffer layer  

SciTech Connect

The authors compare dynamic SEU characteristics of GaAs complementary HIGFET devices fabricated on conventional semi-insulating substrates versus low temperature grown GaAs (LT GaAs) buffer layers. Heavy ion test results on shift register and flip-flop devices from the same process lot demonstrate that the LT GaAs layer provides immunity from upsets, even at an LET value of 90 MeV {center_dot} cm{sup 2}/mg. This result is also consistent with pulsed laser measurements performed on the same flip-flop circuits used in the ion test.

Marshall, P.W.; Weatherford, T.; Carts, M. [Naval Research Lab., Washington, DC (United States)]|[SFA, Inc., Landover, MD (United States); Dale, C.J.; McMorrow, D. [Naval Research Lab., Washington, DC (United States); Peczalski, A.; Baier, S.; Nohava, J.; Skogen, J. [Honeywell Systems and Research Center, Bloomington, MN (United States)

1995-12-01T23:59:59.000Z

76

Ternary rare-earth zinc arsenides REZn{sub 1-x}As{sub 2} (RE=La-Nd, Sm)  

SciTech Connect

The ternary rare-earth zinc arsenides REZn{sub 1-x}As{sub 2} (RE=La-Nd, Sm) were prepared by reaction of the elements at 800 deg. C. Single-crystal and powder X-ray diffraction analysis revealed a defect SrZnBi{sub 2}-type average structure for the La member (Pearson symbol tI16, space group I4/mmm, Z=4; a=4.0770(9) A, c=20.533(5) A), in contrast to defect HfCuSi{sub 2}-type average structures for the remaining RE members (Pearson symbol tP8, space group P4/nmm, Z=2; a=4.0298(5)-3.9520(4) A, c=10.222(1)-10.099(1) A in the progression from Ce to Sm). The homogeneity range is not appreciable (estimated to be narrower than 0.6<1-x<0.7 in SmZn{sub 1-x}As{sub 2}) and the formula REZn{sub 0.67}As{sub 2} likely represents the Zn-rich phase boundary. The Ce-Nd members are Curie-Weiss paramagnets. LaZn{sub 0.67}As{sub 2} shows activated behavior in its electrical resistivity, whereas SmZn{sub 0.67}As{sub 2} exhibits anomalies in its temperature dependence of the electrical resistivity. - Graphical abstract: LaZn{sub 1-x}As{sub 2} adopts a SrZnBi{sub 2}-type structure whereas the remaining members of the REZn{sub 1-x}As{sub 2} series (RE=Ce-Nd, Sm) adopt a HfCuSi{sub 2}-type structure. Highlights: > REZn{sub 1-x}As{sub 2} adopts SrZnBi{sub 2}-type (RE=La) or HfCuSi{sub 2}-type (RE=Ce-Nd, Sm) structures. > Trends in RE substitution and local distortion around Zn-centered tetrahedra can be rationalized by geometrical factors. > Zn vacancies occur to reduce Zn-As and As-As antibonding interactions.

Stoyko, Stanislav S. [Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada); Mar, Arthur, E-mail: arthur.mar@ualberta.ca [Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada)

2011-09-15T23:59:59.000Z

77

GaAs ohmic contacts for high temperature devices  

DOE Green Energy (OSTI)

Instrumentation requirements for geothermal wells, jet engines, and nuclear reactors have exceeded the high temperature capability of silicon devices. As one part of a program to develop high temperature compound semiconductor devices, four basic ohmic contact systems for n-type GaAs have been evaluated for contact resistance as a function of temperature (24 to 350/sup 0/C) and time (at 300/sup 0/C): Ni/AuGe; Ag/Si and Ag/Ni/Si; Al/Ge and Al/AlGe; and Au/Nb/Si and Pt/Nb/Si. Optimization of processing parameters produced viable high temperature contacts with all but the Al/Ge systems. Aging at 300/sup 0/C changed the contact resistivity in only the Ag/Ni/Si contacts. Film adhesion was excellent for the Al/Ge, Ni/AuGe, and Ag/Si systems as measured with ultrasonic Al wire bond pull strengths. Lower adhesion was noticed with Nb/Si systems measured with gold wire bond pull strengths.

Coquat, J.A.; Palmer, D.W.

1980-01-01T23:59:59.000Z

78

Effects of low-temperature buffer-layer thickness and growth temperature on the SEE sensitivity of GaAs HIGFET circuits  

Science Conference Proceedings (OSTI)

Heavy-ion Single Event Effects (SEE) test results reveal the role of growth temperature and buffer layer thickness in the use of a low-temperature grown GaAs (LT GaAs) buffer layer for suppressing SEE sensitivity in GaAs HIGFET circuits.

Weatherford, T.R.; Fouts, D.J. [Naval Postgraduate School, Monterey, CA (United States); Marshall, P.W. [Naval Research Lab., Washington, DC (United States)]|[SFA, Inc., Largo, MD (United States); Marshall, C.J. [Naval Research Lab., Washington, DC (United States); Mathes, B.; LaMacchia, M. [Motorola Government Systems, Scottsdale, AZ (United States)

1997-12-01T23:59:59.000Z

79

The control of size and areal density of InAs self-assembled quantum dots in selective area molecular beam epitaxy on GaAs (001) surface  

Science Conference Proceedings (OSTI)

The growth of InAs quantum dots (QDs) on GaAs (001) substrates by selective area molecular beam epitaxy (SA-MBE) with dielectric mask is investigated. The GaAs polycrystals on the mask, which is formed during growth due to low GaAs selectivity between ... Keywords: InAs quantum dots, Molecular beam epitaxy, Selective area epitaxy

J. C. Lin; P. W. Fry; R. A. Hogg; M. Hopkinson; I. M. Ross; A. G. Cullis; R. S. Kolodka; A. I. Tartakovskii; M. S. Skolnick

2006-12-01T23:59:59.000Z

80

Micro-Photoluminescence Characterization of Low Density Droplet GaAs Quantum Dots for Single Photon Sources  

Science Conference Proceedings (OSTI)

The GaAs quantum dots in AlGaAs barriers were grown by droplet epitaxy, emitting around 700 nm in wavelength which is compatible with low cost Si based detectors. The excitation power dependent and time resolved micro-photoluminescence measurements identified optical characteristics of exciton and biexciton states which are attributed to good quantum confinements in GaAs QDs.

Ha, S.-K.; Song, J. D.; Lim, J. Y.; Choi, W. J.; Han, I. K.; Lee, J. I. [Nano Convergence Devices Center, KIST, Seoul 136-791 (Korea, Republic of); Bounouar, S.; Donatini, F.; Dang, L. S.; Poizat, J. P. [CEA/CNRS/UJF team 'Nanophysics and semiconductors', Institute Neel/CNRS-UJF, 38042 Grenoble (France); Kim, J. S. [Department of Physics, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

2011-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Heteroepitaxial growth of InAs on GaAs(001) by in situ STM located inside MBE growth chamber  

Science Conference Proceedings (OSTI)

The growth of InAs on GaAs(001) is of great interest primarily due to the self-assembly of arrays of quantum dots (QDs) with excellent opto-electronic properties. However, a basic understanding of their spontaneous formation is lacking. Advanced experimental ... Keywords: GaAs, InAs, Molecular beam epitaxy, Quantum dots, Scanning tunneling microscopy

S. Tsukamoto; G. R. Bell; Y. Arakawa

2006-12-01T23:59:59.000Z

82

Influence of post deposition annealing on Y2O3-gated GaAs MOS capacitors and their reliability issues  

Science Conference Proceedings (OSTI)

The feasibility of employing yttrium oxide (Y"2O"3) as high-k gate dielectrics for GaAs metal-oxide-semiconductor (MOS) devices has been investigated. MOS capacitors were fabricated using RF-sputtered deposited Y"2O"3 films on NH"4OH treated n-GaAs substrate. ... Keywords: GaAs, TDDB, Trapping centroid, Y2O3

P. S. Das; A. Biswas

2011-03-01T23:59:59.000Z

83

Particle-induced mitigation of SEU sensitivity in high data rate GaAs HIGFET technologies  

Science Conference Proceedings (OSTI)

Proton and heavy ion data on two GaAs HIGFET logic families, one source coupled (SCFL) and the other complementary (C-HIGFET), show the importance of dynamic testing and develop a new technique for mitigating SEU sensitivity by minimizing charge enhancement effects.

Marshall, P.W.; Weatherford, T.R. [Naval Research Lab., Washington, DC (United States)]|[SFA, Inc., Landover, MD (United States); Dale, C.J. [Naval Research Lab., Washington, DC (United States); La Macchia, M. [Motorola, Inc., Phoenix, AZ (United States); LaBel, K.A. [National Aeronautics and Space Administration, Greenbelt, MD (United States)

1995-12-01T23:59:59.000Z

84

Pulsed laser-induced charge collection in GaAs MESFETs  

Science Conference Proceedings (OSTI)

Pulsed picosecond lasers with variable wavelength have been used to investigate the details of charge collection in GaAs MESFETs. In short gate-length devices, charge collection at the drain may be much larger than at the gate and greater than the charge produced by the laser pulses.

Knudson, A.R.; Campbell, A.B.; McMorrow (Naval Research Lab., Washington, DC (USA)); Buchner, S.; Kang, K. (Martin Marietta Labs., Baltimore, MD (USA)); Weatherford, T. (SFA Inc., Landover, MD (US)); Srinivas, V.; Swartzlander, G.A. Jr.; Chen, Y.J. (Maryland Univ., Baltimore, MD (USA))

1990-12-01T23:59:59.000Z

85

Time response of the high-field electron distribution function in GaAs  

Science Conference Proceedings (OSTI)

Numerical calculations have been made of the high-field electron distribution function for GaAs, its small-signal frequency response and its behavior in large sinusoidal electric fields-The response speed is limited by the low scattering rate within ...

H. D. Rees

1969-09-01T23:59:59.000Z

86

Entanglement in GaAs and CdSe quantum dots: Exact calculations and DFT approximations  

Science Conference Proceedings (OSTI)

We consider two electrons confined in spherical GaAs and CdSe quantum dots and calculate their ground-state spatial entanglement exactly within a parabolic confinement model. We propose a perturbative scheme to approximate the above entanglement within ... Keywords: Density-functional theory, Entanglement, Quantum dots, Quantum information, Semiconductors

J. P. Coe; A. Sudbery; I. D'Amico

2009-03-01T23:59:59.000Z

87

A search for spin-polarized photoemission from GaAs using light with orbital angular momentum  

Science Conference Proceedings (OSTI)

Laser light with photon energy near the bandgap of GaAs and with different amounts of orbital angular momentum was used to produce photoemission from unstrained GaAs. The degree of electron spin polarization was measured using a micro-Mott polarimeter and found to be consistent with zero with an upper limit of ~3% for light with up to ±5{bar h} of orbital angular momentum. In contrast, the degree of spin polarization was 32.32 ± 1.35% using circularly-polarized laser light at the same wavelength, which is typical of bulk GaAs.

Nathan Clayburn, James McCarter, Joan Dreiling, Bernard Poelker, Dominic Ryan, Timothy Gay

2013-01-01T23:59:59.000Z

88

The Surface Activation Layer of GaAs Negative Electron Affinity Photocathode Activated by Cs, Li and NF3  

Science Conference Proceedings (OSTI)

The lifetime of GaAs photocathodes can be greatly improved by introducing Li in the Cs+NF{sub 3} activation process. The surface activation layer of such photocathodes is studied by synchrotron radiation photoemission and is compared with GaAs photocathodes activated without Li. The charge distributions of N, F and Cs experience significant changes when Li is added in the activation. In addition, the presence of Li causes NF{sub x} molecules to take an orientation with F atoms on top. All these changes induced by Li hold the key for the lifetime improvement of GaAs photocathodes.

Sun, Yun; /SLAC, SSRL; Kirby, R.E.; /Saxet Surface Sci.; Maruyama, T.; /SLAC; Mulhollan, G.A.; Bierman, J.C.; /Saxet Surface Sci.; Pianetta, P.; /SLAC, SSRL

2009-12-11T23:59:59.000Z

89

Surface science analysis of GaAs photocathodes following sustained electron beam delivery  

DOE Green Energy (OSTI)

Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power Free Electron Lasers (FEL). Photocathode quantum efficiency (QE) degradation is due to residual gasses in the electron source vacuum system being ionized and accelerated back to the photocathode. These investigations are a first attempt to characterize the nature of the photocathode degradation, and employ multiple surface and bulk analysis techniques to investigate damage mechanisms including sputtering of the Cs-oxidant surface monolayer, other surface chemistry effects, and ion implantation. Surface and bulk analysis studies were conducted on two GaAs photocathodes, which were removed from the JLab FEL DC photoemission gun after delivering electron beam, and two control samples. The analysis techniques include Helium Ion Microscopy (HIM), Rutherford Backscattering Spectrometry (RBS), Atomic Force Microscopy (AFM) and Secondary Ion Mass Spectrometry (SIMS). In addition, two high-polarization strained superlattice GaAs photocathode samples, one removed from the Continuous Electron Beam Accelerator Facility (CEBAF) photoinjector and one unused, were also analyzed using Transmission Electron Microscopy (TEM) and SIMS. It was found that heat cleaning the FEL GaAs wafer introduces surface roughness, which seems to be reduced by prolonged use. The bulk GaAs samples retained a fairly well organized crystalline structure after delivering beam but shows evidence of Cs depletion on the surface. Within the precision of the SIMS and RBS measurements the data showed no indication of hydrogen implantation or lattice damage from ion back bombardment in the bulk GaAs wafers. In contrast, SIMS and TEM measurements of the strained superlattice photocathode show clear crystal damage in the wafer from ion back bombardment.

Carlos Hernandez-Garcia, Fay Hannon, Marcy Stutzman, V. Shutthanandan, Z. Zhu, M. Nandasri, S. V. Kuchibhatla, S. Thevuthasan, W. P. Hess

2012-06-01T23:59:59.000Z

90

Perturbation potential produced by a monolayer of InAs on GaAs,,100... Z. Barticevic,1  

E-Print Network (OSTI)

, using the linear muffin-tin orbital tight-binding method, for the potential of an InAs 001 monolayerAs sand- wiched in bulk 001 -GaAs. This result evidences the impor- tance of excitonic effects in InAs ML of InAs in bulk GaAs 001 have been done mainly using the sp3 s* tight-binding TB method. In spite of its

Vargas, Patricio

91

Spin-Resolved Electronic Structure of Ultrathin Epitaxial Fe Films on Vicinal and Singular GaAs(100) Substrates  

SciTech Connect

Recently there has been considerable interest in the study of spin injection at ferromagnetic semiconductor heterojunctions and ferromagnetic metal--semiconductor contacts. Studies of ntype semiconductors have demonstrated spin-coherent transport over large distances5 and the persistence of spin coherence over a sizeable time scale. Clearly such investigations have been stimulated by the potential of the development of ''spintronics'', electronic devices utilizing the information of the electron spin states. To understand and improve the magnetic properties of ultrathin Fe films on GaAs has been the aim of many research groups over recent years. The interest in this system has both technological and fundamental scientific motivations. Technologically, Fe on GaAs may serve to realize spin electronic devices. From a fundamental science point of view, Fe on GaAs serves as a prototype for studies of the interplay between the crystalline structure and morphology of an ultrathin film, its electronic structure and the long range magnetic order it exhibits. Furthermore, it is well known that an oxidized Cs layer on GaAs substantially alters the work-function of the GaAs surface, which plays a very important role in the application of GaAs as a spin polarized electron source.

Morton, S A; Waddill, G D; Spangenberg, M; Seddon, E A; Neal, J; Shen, T; Tobin, J G

2003-03-10T23:59:59.000Z

92

Single event induced charge transport modeling of GaAs MESFETs  

SciTech Connect

Previous studies examining single event charge collection in GaAs MESFETs have revealed enhanced charge collection, in which the drain charge collection can be as high as 8 times the amount of charge deposited in the device. The understanding of these charge amplifying mechanisms requires correlation between experimental and simulation analysis. Two-dimensional computer simulations of charge collection phenomena in GaAs MESFETs have been performed for alpha and laser ionization. In both cases more charge is collected than is created by the ionizing event. The simulations indicate that a bipolar transport mechanism (t < 60 ps) and a channel modulation mechanism (t > 40 ps) are responsible for this enhanced charge collection.

Weatherford, T.R.; Knudson, A.R. (SFA Inc., Landover, MD (United States)); McMorrow, D.; Campbell, A.B. (Naval Research Lab., Washington, DC (United States)); Curtice, W.R. (W.R. Curtice Consulting, Princeton Junction, NJ (United States))

1993-12-01T23:59:59.000Z

93

Heavy ion and proton analysis of a GaAs C-HIGFET SCRAM  

Science Conference Proceedings (OSTI)

The authors present heavy ion and proton upset measurements, including total dose, and displacement damage on a one micron, GaAs, complementary-heterostructure insulated-gate FET (C-HIGFET) 1k x 1 SRAM. SEU characteristics show a two order of magnitude improvement over GaAs MESFET technology. Heavy-ion upset equilibrium measurements show that all cells upset with equal probability at the five percent LET threshold. This indicates that for this device the shape of the cross section versus LET curve is a result of a probability distribution that applies to all cells and is not the result of variations in cell sensitivities. The data set also indicates that the traditional two-dimensional cos([theta]) normalization to LET and fluence are not applicable to this technology.

Cutchin, J.H.; Marshall, P.W.; Weatherford, T.R. (SFA Inc., Landover, MD (United States) Naval Research Lab., Washington, DC (United States)); Langworthy, J.; Petersen, E.L.; Campbell, A.B. (Naval Research Lab., Washington, DC (United States)); Hanka, S.; Peczalski, A. (Honeywell, Inc., Minneapolis, MN (United States))

1993-12-01T23:59:59.000Z

94

SEU rate prediction and measurement of GaAs SRAMs onboard the CRRES satellite  

SciTech Connect

The Combined Release and Radiation Effects Satellite (CRRES) launched in July of 1990 included experiments to study effects of Single Event Upset (SEU) on various microelectronic ICs. The MicroElectronics Package (MEP) subsection of the satellite experiments monitored upset rates on 65 devices over a 15 month period. One of the purposes of the SEU experiments was to determine if the soft error modeling techniques were of sufficient accuracy to predict error rates, and if not, to determine where the deficiencies existed. An analysis is presented on SPICE predicted, SEU ground tested, and CRRES observed heavy ion and proton soft error rates of GaAs SRAMs. Upset rates overestimated the susceptibility of the GaAs SRAMs. Differences are accounted to several factors.

Weatherford, T.R.; McDonald, P.T. (SFA, Inc., Landover, MD (United States) Naval Research Lab., Washington, DC (United States)); Campbell, A.B.; Langworthy, J.B. (Naval Research Lab., Washington, DC (United States))

1993-12-01T23:59:59.000Z

95

Effects of atomic hydrogen and deuterium exposure on high polarization GaAs photocathodes  

DOE Green Energy (OSTI)

Strained-layer GaAs and strained-superlattice GaAs photocathodes are used at Jefferson Laboratory to create high average current beams of highly spin-polarized electrons. High electron yield, or quantum efficiency (QE), is obtained only when the photocathode surface is atomically clean. For years, exposure to atomic hydrogen or deuterium has been the photocathode cleaning technique employed at Jefferson Laboratory. This work demonstrates that atomic hydrogen cleaning is not necessary when precautions are taken to ensure that clean photocathode material from the vendor is not inadvertently dirtied while samples are prepared for installation inside photoemission guns. Moreover, this work demonstrates that QE and beam polarization can be significantly reduced when clean high-polarization photocathode material is exposed to atomic hydrogen from an rf dissociator-style atomic hydrogen source. Surface analysis provides some insight into the mechanisms that degrade QE and polarization due to atomic hydrogen cleaning.

M. Baylac; P. Adderley; J. Brittian; J. Clark; T. Day; J. Grames; J. Hansknecht; M. Poelker; M. Stutzman; A. T. Wu; A. S. Terekhov

2005-12-01T23:59:59.000Z

96

Triggering GaAs lock-on switches with laser diode arrays  

Science Conference Proceedings (OSTI)

Many of the applications that require the unique capabilities of Photoconductive Semiconductor Switches (PCSS) demand a compact package. We have been able to demonstrate that GaAs switches operated in the high gain mode called lock-on'' meet the required electrical switching parameters of several such applications using small switch sizes. The only light source that has enough power to trigger a PCSS and is compatible with a small package is a laser diode. This paper will describe the progress that leads to the triggering of high power PCSS switches with laser diodes. Our goal is to switch up to 5 kA in a single shot mode and up to 100 MW repetitively at up to 10 kHz. These goals are feasible since the switches can be used in parallel or in series. Low light level triggering became possible after the discovery of a high electric field, high gain switching mode in GaAs (and later in InP). At electric fields below 3 kV/cm GaAs switches are activated by creation of, at most, only one conduction electron- valence hole pair per photon absorbed in the sample. This linear mode demands high laser power and, after the light is extinguished, the carriers live for only a few nanoseconds. At higher electric fields GaAs behaves as a light activated Zener diode. The laser light generates carriers as in the linear mode and the field induces gain such that the amount of light required to trigger the switch is reduced by a factor of up to 500. The gain continues until the field across the sample drops to a material dependent lock-on field. At this point the switch will carry as much current as, and for as long as, the circuit can maintain the lock-on field. The gain in the switch allows for the use of laser diodes. 8 refs., 11 figs.

Loubriel, G.M.; Helgeson, W.D.; McLaughlin, D.L.; O'Malley, M.W.; Zutavern, F.J. (Sandia National Labs., Albuquerque, NM (USA)); Rosen, A.; Stabile, P.J. (David Sarnoff Research Center, Princeton, NJ (USA))

1990-01-01T23:59:59.000Z

97

Proton and heavy ion upsets in GaAs MESFET devices  

Science Conference Proceedings (OSTI)

This paper reports on proton and heavy SEU data that has been obtained for devices made by several GaAs MESFET manufacturers. Proton energy dependence and proton and heavy ion upset cross sections are reported. Measurements of charge collection from latches designed with various gate widths show that charge collection depths appear deeper than the 1 {mu}m depth expected. Critical charge does not scale linearly with area. Proton upset cross sections are reduced with increased device width.

Weatherford, T.R.; Tran, L. (Sachs/Freeman Associates, Inc., Bowie, MD (United States)); Stapor, W.J.; Petersen, E.L.; Langworthy, J.B.; McMorrow, D. (Naval Research Lab., Washington, DC (United States)); Abdel-Kader, W.G.; McNulty, P.J. (Clemson Univ., SC (United States). Dept. of Physics and Astronomy)

1991-12-01T23:59:59.000Z

98

DIRECT DETERMINATION OF THE STACKING ORDER IN GD2O3 EPI LAYERS ON GAAS.  

SciTech Connect

We have used Coherent Bragg Rod Analysis (COBRA) to investigate the atomic structure of a 5.6 nm thick Gd{sub 2}O{sub 3} film epitaxially grown on a (100) GaAs substrate. COBRA is a method to directly obtain the structure of systems periodic in two-dimensions by determining the complex scattering factors along the substrate Bragg rods. The system electron density and atomic structure are obtained by Fourier transforming the complex scattering factors into real space. The results show that the stacking order of the first seven Gd{sub 2}O{sub 3} film layers resembles the stacking order of Ga and As layers in GaAs then changes to the stacking order of cubic bulk Gd{sub 2}O{sub 3}. This behavior is distinctly different from the measured stacking order in a 2.7 nm thick Gd{sub 2}O{sub 3} in which the GaAs stacking order persists throughout the entire film.

YACOBY,Y.; SOWWAN,M.; PINDAK,R.; CROSS,J.; WALKO,D.; STERN,E.; PITNEY,J.; MACHARRIE,R.; HONG,M.; CLARKE,R.

2002-12-06T23:59:59.000Z

99

Gallium arsenide-based ternary compounds and multi-band-gap solar cell research. Annual subcontract report, 15 April 1988--14 June 1990  

DOE Green Energy (OSTI)

Aim of this contract is the achievement of a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed is metalorganic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or may contain a p-n junction of its own and form the bottom cell of a two junction tandem solar cell structure. The III-V material for the single-junction case is GaAs and for the two-junction case is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include the following: (1) a 17.6% efficient GaAs-on-Si solar cell; (2) an 18.5% efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8% efficient GaAs-on-GaAs solar cell; (4) a 28.7% efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

Vernon, S. [Spire Corp., Bedford, MA (United States)

1993-02-01T23:59:59.000Z

100

Gallium arsenide-based ternary compounds and multi-band-gap solar cell research. Final subcontract report, 1 April 1988--31 March 1990  

DOE Green Energy (OSTI)

This report describes work to achieve a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed throughout this work is metal-organic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or it may contain a p-n junction of its own and form the bottom cell of a two-junction tandem solar cell structure. The III-V material for the single-junction case is GaAs, and for the two-junction case it is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include (1) a 17.6%-efficient GaAs-on-Si solar cell; (2) an 18.5%-efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8%-efficient GaAs-on-GaAs solar cell; (4) a 28.7%-efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) the measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

Vernon, S. [Spire Corp., Bedford, MA (United States)

1993-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


101

Development of polycrystal GaAs solar cells. Quarterly technical progress report No. 1, January 15-April 30, 1979  

DOE Green Energy (OSTI)

The objective of this program is to develop a thin film GaAs solar cell technology with the potential of yielding cells with 12 to 15% efficiency and to develop thin film growth techniques which are compatible with the low cost production goal of $500/kW-peak. Progress is reported on a study of junction formation in large grain polycrystal GaAs; characterization of the electronic properties of polycrystal GaAs grown by MBE on low cost foreign substrates; optimizing the structure of AlGaAs-GaAs heterojunction Schottky barrier solar cells; and a variety of grain boundary measurements, including Scanning Light Microscopy (SLM), Deep Level Transient Spectroscopy (DLTS), SIMS, and temperature dependent resistivity.

Miller, D.L.; Cohen, M.J.; Harris, J.S. Jr.; Ballantyne, J.; Hoyte, A.; Stefanakos, E.

1979-05-01T23:59:59.000Z

102

Magnetism and transport properties of epitaxial Fe-Ga thin films on GaAs(001)  

SciTech Connect

Epitaxial Fe-Ga thin films in disordered bcc {alpha}-Fe crystal structure (A2) have been grown on GaAs(001) by molecular beam epitaxy. The saturated magnetization (M{sub S}) decreased from 1371 to 1105 kA/m with increasing Ga concentration from 10.5 to 24.3 % at room temperature. The lattice parameter increased with the increase in Ga content because of the larger atomic radius of Ga atom than that of Fe. The increase in carrier density with Ga content caused in lower resistivity.

Duong Anh Tuan; Shin, Yooleemi; Cho, Sunglae [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Dang Duc Dung [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Department of General Physics, School of Engineering Physics, Ha Noi University of Science and Technology, 1 Dai Co Viet road, Ha Noi (Viet Nam); Vo Thanh Son [Centers for Nanobioenineering and Spintronics, Chungnam National University, Daejon 350-746 (Korea, Republic of)

2012-04-01T23:59:59.000Z

103

Status of High Polarization DC High Voltage GaAs Photoguns  

SciTech Connect

This talk will review the state of the art of high polarization GaAs photoguns used worldwide. Subject matter will include drive laser technology, photocathode material, gun design, vacuum requirements and photocathode lifetime as a function of beam current. Recent results have demonstrated high current, 85% polarized beams with high reliability and long lifetime under operational conditions. Research initiatives for ensuring production of high average and peak current beams for future accelerator facilities such as ELIC and the ILC will be also discussed.

P. A. Adderley; J. Brittian; J. Clark; J. Grames; J. Hansknecht; J. McCarter; M. Poelker; M. L. Stutzman; R. Suleiman; K. E. L. Surles-Law

2007-08-01T23:59:59.000Z

104

Nano structuring of GaAs(100) surface using low energy ion irradiation  

SciTech Connect

Nanostructuring of semi insulating GaAs (100) has been observed after irradiation of 50 keV Ar{sup +} ion beam in a wide angular range of 0 deg. to 60 deg. with respect to surface normal. Atomic Force Microscopy (AFM) analysis shows the formation of nano dots at smaller angle of irradiation. At higher angle of irradiation, self organized ripples were developed on the surface. The rms roughness estimated from the AFM analysis shows exponential growth with angle of irradiation. In the high frequency regime, PSD analysis suggests that surface morphology of the irradiated samples is governed by the surface diffusion and mass transport dominated processes.

Kumar, Tanuj; Khan, S. A.; Verma, S.; Kanjilal, D. [Inter-university Accelerator Centre, Aruna Asaf Ali Marg, New Delhi-110067 (India)

2012-06-05T23:59:59.000Z

105

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

106

Triggering GaAs lock-on switches with laser diode arrays  

SciTech Connect

Laser diode arrays have been used to trigger GaAs Photoconducting Semiconductor Switches (PCSS) charged to voltages of up to 60 kV and conducting currents of 580 A. The driving forces behind the use of laser diode arrays are compactness, elimination of complicated optics, and the ability to run at high repetition rates. Laser diode arrays are compactness, elimination of complicated optics, and the ability to run at high repetition rates. Laser diode arrays can trigger GaAs at high fields as the result of a new switching mode (lock-on) with very high carrier number gain. We have achieved switching of up to 10 MW in a 60 {Omega} system, with a pulse rise time of 500 ps. At 1.2 MW we have achieved repetition rates of 1 kHz with switch rise time of 500 ps for 10{sup 5} shots. The laser diode array used for these experiments delivers a 166 W pulse. In a single shot mode we have switched 4 kA with a flash lamp pumped laser and 600 A with the 166 W array. 7 refs., 5 figs.

Loubriel, G.M.; Buttram, M.T.; Helgeson, W.D.; McLaughlin, D.L.; O'Malley, M.W.; Zutavern, F.J. (Sandia National Labs., Albuquerque, NM (USA)); Rosen, A.; Stabile, P.J. (David Sarnoff Research Center, Princeton, NJ (USA))

1990-01-01T23:59:59.000Z

107

Charge collection in GaAs MESFETs fabricated in semi-insulating substrates  

SciTech Connect

Charge-collection in GaAs MESFETs fabricated in semi-insulating substrates is investigated. Current transients are measured at short times ({approximately} few picoseconds) after either an alpha-particle strike or a laser pulse. In addition, the total charge is obtained by integrating the collected current. Measurements show the existence of three mechanisms for charge collection: (1) the drift of holes and electrons to the gate and drain electrodes, respectively, (2) bipolar-gain, and (3) channel-modulation. The charge collected by drift of holes or electrons gives rise to an instrument limited response (within 20 ps) after a laser pulse. The bipolar-gain mechanism peaks in approximately {approximately} 200 ps and is responsible for most of the collected charge. The channel-modulation mechanism is responsible for charge collection at longer times. These results are different than previous results for MESFETs fabricated on top of a buried p-layer, where most of the charge was found to be collected by the channel-modulation mechanism. These results indicate that in order to harden GaAs transistors to single event upset, one must use techniques that reduce the effects of the bipolar-gain and channel-modulation mechanisms.

Schwank, J.R.; Sexton, F.W. [Sandia National Labs., Albuquerque, NM (United States); Weatherford, T.R.; McMorrow, D.; Knudson, A.R.; Melinger, J.S. [Naval Research Lab., Washington, DC (United States)

1995-12-01T23:59:59.000Z

108

I-V analysis of high-energy lithium-ion-irradiated Si and GaAs solar cells  

E-Print Network (OSTI)

Space-grade Si and GaAs solar cells were irradiated with 15 and 40 MeV lithium ions. Dark-IV analysis (with and without illumination) reveals differences in the effects of such irradiation on the different cell types

A. Meulenberg Jr; B. Jayashree; Ramani; M. C. Radhakrishna; A. K. Saif

2007-09-07T23:59:59.000Z

109

Development of polycrystal GaAs solar cells. Quarterly technical progress report No. 3, August 1, 1979-October 30, 1979  

DOE Green Energy (OSTI)

Progress at Rockwell International, Cornell University, and North Carolina A and T State University on the development of thin film polycrystal GaAs solar cells with a 10% conversion efficiency is described. Highlights include the growth of Ge on Fe substrates and the investigation of various grain boundary passivation schemes. (WHK)

Miller, D.L.; Cohen, M.J.; Harris, J.S. Jr.; Ballantyne, J.; Stefanakos, E.

1979-12-01T23:59:59.000Z

110

Ultrafast dynamics of Coulomb correlated excitons in GaAs quantum wells  

Science Conference Proceedings (OSTI)

The author measures the transient nonlinear optical response of room temperature excitons in gallium arsenide quantum wells via multi-wave mixing experiments. The dynamics of the resonantly excited excitons is directly reflected by the ultrafast decay of the induced nonlinear polarization, which radiates the detected multi-wave mixing signal. She characterizes this ultrafast coherent emission in both amplitude and phase, using time- and frequency-domain measurement techniques, to better understand the role of Coulomb correlation in these systems. To interpret the experimental results, the nonlinear optical response of a dense medium is calculated using a model including Coulomb interaction. She contributes three new elements to previous theoretical and experimental studies of these systems. First, surpassing traditional time-integrated measurements, she temporally resolves the amplitude of the ultrafast coherent emission. Second, in addition to measuring the third-order four-wave mixing signal, she also investigates the fifth-order six-wave mixing response. Third, she characterizes the ultrafast phase dynamics of the nonlinear emission using interferometric techniques with an unprecedented resolution of approximately 140 attoseconds. The author finds that effects arising from Coulomb correlation dominate the nonlinear optical response when the density of excitons falls below 3 {times} 10{sup 11} cm{sup {minus}2}, the saturation density. These signatures of Coulomb correlation are investigated for increasing excitation density to gradually screen the interactions and test the validity of the model for dense media. The results are found to be qualitatively consistent with both the predictions of the model and with numerical solutions to the semiconductor Bloch equations. Importantly, the results also indicate current experimental and theoretical limitations, which should be addressed in future research.

Mycek, M.A. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

1995-12-01T23:59:59.000Z

111

Picosecond radiation-induced current transients in digital GaAs MESFETs  

Science Conference Proceedings (OSTI)

Picosecond-resolution measurements of the current transients produced when energetic ions (alpha particles) interact with high-speed digital GaAs MESFETs are presented. Measurements as a function of device bias and temperature reveal the presence of several different contributions to the charge-collection transients, ranging in time scale from picoseconds to microseconds. The effects of permanent radiation damage are found to degrade device performance to the extent that reliable measurement of the ion-induced transients is difficult and, in many cases, impossible. The use of above-bandgap picosecond laser excitation is revealed to be a viable alternative to the use of heavy ions for characterization of the charge-collection dynamics in semiconductor devices.

McMorrow, D.; Campbell, A.B.; Knudson, A.R.; Weatherford, T.R.

1992-05-22T23:59:59.000Z

112

Single-event dynamics of high-performance HBTs and GaAs MESFETs  

SciTech Connect

Picosecond charge-collection transients measured for GaAs/AlGaAs HBTs following 3.0 MeV [alpha]-particle and 620 nm picosecond laser excitation reveal charge-collection efficiencies up to twenty-eight times smaller than for GaAs MESFETs, with [approximately]90% of the charge collected within 75 ps of the ionizing event. The small charge-collection efficiency of the HBTs is a consequence of the ultrafast charge-collection dynamics in these devices. The authors show that picosecond laser excitation reproduces nicely the ion-induced transients, providing a valuable tool for the investigation of charge-collection and SEU phenomena in these devices.

McMorrow, D.; Melinger, J.S.; Campbell, A.B. (Naval Research Lab., Washington, DC (United States)); Weatherford, T.; Knudson, A.R.; Tran, L.H.

1993-12-01T23:59:59.000Z

113

Charge collection in GaAs MESFET circuits using a high energy microbeam  

Science Conference Proceedings (OSTI)

The mechanisms responsible for single event upsets can be studied more realistically in transistors that are part of an integrated test circuit than in single isolated test transistors with fixed biases on all the nodes. Both energetic, heavy ions and focused, pulsed laser light were used to generate transient voltages at a number of different nodes in a GaAs MESFET integrated test circuit. Three-dimensional maps of charge collection regions were generated with the use of the scanning ion microprobe at Gesellschaft fuer Schwerionenforschung (GSI). The results showed that charge was collected from all areas of the circuit, but with different efficiencies at different injection sites. Regions not covered with metal were exposed to pulsed laser light. The resulting transients had pulse shapes similar to those generated by ions and amplitudes that also depended on ion strike location. These results illustrate the usefulness of the ion microprobe technique for obtaining spatial and temporal information about SEU in integrated circuits.

Buchner, S.; Weatherford, T.; Knudson, A.; McDonald, P. [SFA, Landover, MD (United States); Campbell, A.B.; McMorrow, D. [Naval Research Lab., Washington, DC (United States); Fischer, B.; Metzger, S.; Schloegl, M. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)

1996-12-01T23:59:59.000Z

114

Fano Resonance in GaAs 2D Photonic Crystal Nanocavities  

SciTech Connect

We report the results of polarization resolved reflectivity experiments in GaAs air-bridge photonic crystals with L3 cavities. We show that the fundamental L3 cavity mode changes, in a controlled way, from a Lorentzian symmetrical lineshape to an asymmetrical form when the linear polarization of the incident light is rotated in the plane of the crystal. The different lineshapes are well fitted by the Fano asymmetric equation, implying that a Fano resonance is present in the reflectivity. We use the scattering matrix method to model the Fano interference between a localized discrete state (the cavity fundamental mode) and a background of continuum states (the light reflected from the crystal slab in the vicinity of the cavity) with very good agreement with the experimental data.

Valentim, P. T.; Guimaraes, P.S. S. [Departamento de Fisica, Universidade Federal de Minas Gerais, Belo Horizonte (Brazil); Instituto Nacional de Ciencia e Tecnologia de Nanodispositivos Semicondutores - INCT-DISSE (Brazil); Luxmoore, I. J.; Szymanski, D.; Whittaker, D. M.; Fox, A. M.; Skolnick, M. S. [Department of Physics and Astronomy, University of Sheffield, Sheffield (United Kingdom); Vasco, J. P. [Instituto de Fisica, Universidad de Antioquia, Medellin (Colombia); Vinck-Posada, H. [Departamento de Fisica, Facultad de Ciencias, Universidad Nacional de Colombia, Bogota (Colombia)

2011-12-23T23:59:59.000Z

115

Excitation Power Dependence Of Photoluminescence From GaAs Quantum Dot Prepared By Droplet Epitaxy Method  

Science Conference Proceedings (OSTI)

GaAs quantum dot (QD) was grown by droplet epitaxy (DE) method and the excitation power dependence of photoluminescence (PL) were carried out. To investigate the effect of annealing temperature on QDs optical properties, the two step RTA process was carried out in a various temperature range from 800 to 1000 deg. C. As the thermal annealing temperature increases, the PL peak position is blue-shifted due to the change of the composition and size distribution of QDs, and the highest PL intensity is observed at the sample annealed at 900 deg. C. The integrated PL intensity (I{sub PL}) is plotted against the excitation density in a log-log scale and the slope was calculated.

Choi, H. Y.; Kim, D. Y.; Cho, M. Y.; Kim, G. S.; Jeon, S. M.; Yim, K. G.; Kim, M. S.; Leem, J. Y. [Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Gimhae (Korea, Republic of); Lee, D. Y. [Epi-manufacturing Technology, Samsung LED Co., Ltd., Suwon (Korea, Republic of); Kim, J. S. [Division of Advanced Materials Engineering, Chonbuk National University, Jeonju (Korea, Republic of); Kim, J. S. [Department of Physics, Yeungnam University, Gyeongsan (Korea, Republic of); Son, J. S. [Department of Visual Optics, Kyungwoon University, Gumi (Korea, Republic of); Lee, J. I. [Advanced Instrument Technology Center, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

2011-12-23T23:59:59.000Z

116

Energy distribution of nonequilibrium electrons and optical phonons in GaAs under band-to-band pumping by intense short pulses of light  

SciTech Connect

Deviation from the Fermi distribution of nonequilibrium electrons and distribution of 'hot' optical phonons in GaAs under band-to-band pumping by picosecond pulses of light are calculated.

Altybaev, G. S.; Kumekov, S. E., E-mail: skumekov@mail.ru; Mahmudov, A. A. [Satpaev Kazakh National Technical University (Kazakhstan)

2009-03-15T23:59:59.000Z

117

High quality metamorphic graded buffers with lattice-constants intermediate to GaAs an InP for device applications  

E-Print Network (OSTI)

We have investigated the use of a continuous, linear grading scheme for compositionally-graded metamorphic InxGal-As buffers on GaAs, which can be used as virtual substrates for optical emitters operating at wavelengths > ...

Lee, Kenneth Eng Kian

2009-01-01T23:59:59.000Z

118

Self-cleaning and surface recovery with arsine pretreatment in ex situ atomic-layer-deposition of Al2O3 on GaAs  

E-Print Network (OSTI)

. heavily doped GaAs 001 substrates at 650 °C with TMG Ga CH3 3 and arsine AsH3 V/III=23 with disilane Si2H6

119

Arsenides, Phosphides - Programmaster.org  

Science Conference Proceedings (OSTI)

May 27, 2010 ... Besides the known challenges of III/V on IV heteroepitaxy, like charge .... Although carbon tetrahalogenides, such as CBr4, CCl4, and CBrCl3, ...

120

Deep-Level Transient Spectroscopy in InGaAsN Lattice-Matched to GaAs: Preprint  

Science Conference Proceedings (OSTI)

This conference paper describes the deep-level transient spectroscopy (DLTS) measurements have been performed on the quaternary semiconductor InGaAsN. A series of as-grown, metal-organic chemical vapor deposited samples having varying composition were grown and measured. A GaAs sample was used as a baseline for comparison. After adding only In to GaAs, we did not detect significant additional defects; however, adding N and both N and In led to larger hole-trap peaks and additional electron-trap peaks in the DLTS data. The samples containing about 2% N, with and without about 6% In, had electron traps with activation energies of about 0.2 and 0.3 eV. A sample with 0.4% N had an electron trap with an activation energy of 0.37 eV.

Johnston, S. W.; Ahrenkiel, R. K.; Friedman, D. J.; Kurtz, S. R.

2002-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

dc field-emission analysis of GaAs and plasma-source ion-implanted stainless steel  

DOE Green Energy (OSTI)

Field-emission studies have been performed on a GaAs wafer and a sample of its stainless-steel (SS) support electrode that are part of a photocathode gun for the 10 kW Upgrade infrared free electron laser at Jefferson Lab. The objective of the studies presented here is to characterize the effect of both the cleanliness of the wafer and the plasma-source ion-implanted layer on the electrode to suppress field emission. Field emission is the limiting factor to achieve the required 6 MV/m at the surface of the wafer. Potential field emitters are first located on the surface of 1 in. diameter samples with a dc scanning field-emission microscope at 60 MV/m, then each emitter is characterized in a scanning electron microscope equipped with an energy dispersive spectrometer. The GaAs wafer was hydrogen cleaned before the study. The results show three emitters caused by indium contamination during wafer handling. The GaAs wafer thus shows good high-voltage characteristics and the need to maintain cleanliness during handling. The SS sample is hand polished with diamond paste to a 1-m surface finish, then implanted with N2/SiO2 in a plasma-source ion-implantation chamber in preparation for the field-emission studies.

C. Hernandez; T. Wang; T. Siggins; D. Bullard; H. F. Dylla; C. Reece; N. D. Theodore; D. M. Manos

2003-06-01T23:59:59.000Z

122

High efficiency thin-film GaAs solar cells. First interim report, March 1--August 30, 1977  

DOE Green Energy (OSTI)

The objective is to demonstrate the feasibility of producing high-efficiency (15% or greater) thin-film GaAs solar cells with costs suitable for terrestrial solar electric power generation. The approach is that of growing GaAs by organio-metallic chemical vapor deposition on recrystallized germanium (Ge) films previously deposited on metal substrates and fabricating AMOS (Antireflecting Metal-Oxide-Semiconductor) solar cells on the GaAs. Previously it had been determined that a water vapor-grown native oxide (temperature = 25/sup 0/C) was the most useful native oxide for AMOS cells. A new chemical surface preparation prior to oxide growth led to more uniform oxides and reduced interface contamination, yielding lower reverse saturation current densities, a near-unity diode ideality factor, and better reproducibility. Substituting silver (Ag) for gold metallization showed no change in starting cell efficiency, but did greatly improve high temperature stability of the AMOS solar cell. A new study was completed on antireflection coatings on AMOS GaAs solar cells, taking into account the spectral response of the cell and nature of the solar spectra, and the results submitted for publication. XPS (X-ray Photoelectron Spectroscopy) studies had found earlier that the more efficient native oxides had primarily As/sub 2/O/sub 3/ and Ga/sub 2/O/sub 3/ with little GaAsO/sub 4/. A new chemical step etching was developed which can be used to profile the oxide in 5- to 7-A/sup 0/ steps without modifying the oxide chemistry as does ion sputtering. A new Schottky barrier structure is described which can give cell efficiencies up to 16% without oxide interfacial layer effects and 20 to 22% with a moderate interfacial layer effect. AMOS solar cells fabricated on sliced polycrystalline GaAs wafers with 100- to 500-..mu..m grains using Sb/sub 2/O/sub 3/ deposited oxides showed 14% cell efficiency compared to 16.2% in a region with few grains.

Stirn, R.J.

1977-12-01T23:59:59.000Z

123

Nuclear radiation detectors based on a matrix of ion-implanted p-i-n diodes on undoped GaAs epilayers  

Science Conference Proceedings (OSTI)

Samples of nuclear detectors which represent matrices of p-i-n diodes were fabricated based on undoped gallium arsenide epitaxial layers by ion implantation technology. The detectors have a size of the active area of 0.4 Multiplication-Sign 0.4 and 0.9 Multiplication-Sign 0.9 cm{sup 2}. Electrical characteristics of fabricated detectors and results of measurements of fast neutrons spectra of {sup 241}Am-Be source by the recoil protons method are discussed.

Baryshnikov, F. M.; Britvich, G. I.; Chernykh, A. V.; Chernykh, S. V.; Chubenko, A. P.; Didenko, S. I.; Koltsov, G. I. [National University of Science and Technology 'MISIS', Leninskiy prospect 4, 119049 Moscow (Russian Federation); Institute for High Energy Physics, Polshhad nauki 1, 142281 Protvino (Russian Federation); National University of Science and Technology 'MISIS', Leninskiy prospect 4, 119049 Moscow (Russian Federation); P.N. Lebedev Physical Institute of the RAS, Leninskiy prospect 53, 119991 Moscow (Russian Federation); National University of Science and Technology 'MISIS', Leninskiy prospect 4, 119049 Moscow (Russian Federation)

2012-11-06T23:59:59.000Z

124

Exposure of GaAs to atomic hydrogen for cleaning prior to NEA photocathode activation  

DOE Green Energy (OSTI)

Creating an atomically clean semiconductor surface is an essential step in preparing negative electron affinity (NEA) photoemission cathodes. While bulk GaAs can be satisfactorily cleaned by chemical etching and in situ heat cleaning, many high polarization electron source materials are either much too thin, or have oxides and carbides which are too tightly bound, to be cleaned by these methods. Some polarized source candidate materials may be degraded during the heat cleaning step. It is well established that the exposure of many III-V, II-VI, and elemental semiconductors to atomic hydrogen, typically at elevated temperatures, produces semiconductor surfaces free of contamination. Furthermore, this cleaning, possibly followed by thermal annealing, leaves surfaces which show sharp LEED patterns, indicating good stoichiometry and surface order. Atomic hydrogen cleaning should eliminate the chemical etching step, and might reduce the temperature and/or temperature-time product presently used in forming NEA cathodes. The process is readily adaptable to in situ use in ultrahigh vaccum.

Sinclair, C.K.; Poelker, B.M.; Price, J.S. [Jefferson Lab., Newport News, VA (United States)

1998-12-31T23:59:59.000Z

125

HfO2 Gate Dielectric on (NH4)2S Passivated (100) GaAs Grown by Atomic Layer Deposition  

Science Conference Proceedings (OSTI)

The interface between hafnium oxide grown by atomic layer deposition and (100) GaAs treated with HCl cleaning and (NH{sub 4}){sub 2}S passivation has been characterized. Synchrotron radiation photoemission core level spectra indicated successful removal of the native oxides and formation of passivating sulfides on the GaAs surface. Layer-by-layer removal of the hafnia film revealed a small amount of As{sub 2}O{sub 3} formed at the interface during the dielectric deposition. Traces of arsenic and sulfur out-diffusion into the hafnia film were observed after a 450 C post-deposition anneal, and may be the origins for the electrically active defects. Transmission electron microscopy cross section images showed thicker HfO{sub 2} films for a given precursor exposure on S-treated GaAs versus the non-treated sample. In addition, the valence-band and the conduction-band offsets at the HfO{sub 2}/GaAs interface were deduced to be 3.18 eV and a range of 0.87-0.97 eV, respectively. It appears that HCl+(NH{sub 4})2{sub S} treatments provide a superior chemical passivation for GaAs and initial surface for ALD deposition.

Chen, P.T.; /Stanford U., Materials Sci. Dept.; Sun, Y.; /SLAC, SSRL; Kim, E.; McIntyre, P.C.; /Stanford U., Materials Sci. Dept.; Tsai, W.; Garner, M.; /Intel, Santa Clara; Pianetta, P.; /SLAC, SSRL; Nishi, Y.; /Stanford U., Elect. Eng. Dept.; Chui, C.O.; /UCLA

2007-09-28T23:59:59.000Z

126

June 15, 2006 GYPSUM DRYWALL  

E-Print Network (OSTI)

cone, the horizontal flow of SCC is measured. In addition, SCC must also be able to pass through tight not be able to flow through tight spaces, such as congested reinforcement, and would exhibit poor segregation, increased sand-aggregate ratio (S/A), and reduced maximum aggregate size. In proportioning SCC, it is common

127

National Gypsum | Open Energy Information  

Open Energy Info (EERE)

Information About Partnership with NREL Partnership with NREL Yes Partnership Type Test & Evaluation Partner Partnering Center within NREL Electricity Resources & Building...

128

GaAs structures with InAs and As quantum dots produced in a single molecular beam epitaxy process  

Science Conference Proceedings (OSTI)

Epitaxial GaAs layers containing InAs semiconductor quantum dots and As metal quantum dots are grown by molecular beam epitaxy. The InAs quantum dots are formed by the Stranskii-Krastanow mechanism, whereas the As quantum dots are self-assembled in the GaAs layer grown at low temperature with a large As excess. The microstructure of the samples is studied by transmission electron microscopy. It is established that the As metal quantum dots formed in the immediate vicinity of the InAs semiconductor quantum dots are larger in size than the As quantum dots formed far from the InAs quantum dots. This is apparently due to the effect of strain fields of the InAs quantum dots upon the self-assembling of As quantum dots. Another phenomenon apparently associated with local strains around the InAs quantum dots is the formation of V-like defects (stacking faults) during the overgrowth of the InAs quantum dots with the GaAs layer by low-temperature molecular beam epitaxy. Such defects have a profound effect on the self-assembling of As quantum dots. Specifically, on high-temperature annealing needed for the formation of large-sized As quantum dots by Ostwald ripening, the V-like defects bring about the dissolution of the As quantum dots in the vicinity of the defects. In this case, excess arsenic most probably diffuses towards the open surface of the sample via the channels of accelerated diffusion in the planes of stacking faults.

Nevedomskii, V. N., E-mail: nevedom@mail.ioffe.ru; Bert, N. A.; Chaldyshev, V. V., E-mail: Chald@gvg.ioffe.ru [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Preobrazhenskii, V. V.; Putyato, M. A.; Semyagin, B. R. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Division (Russian Federation)

2009-12-15T23:59:59.000Z

129

Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge  

DOE Patents (OSTI)

A multi-junction, monolithic, photovoltaic solar cell device is provided for converting solar radiation to photocurrent and photovoltage with improved efficiency. The solar cell device comprises a plurality of semiconductor cells, i.e., active p/n junctions, connected in tandem and deposited on a substrate fabricated from GaAs or Ge. To increase efficiency, each semiconductor cell is fabricated from a crystalline material with a lattice constant substantially equivalent to the lattice constant of the substrate material. Additionally, the semiconductor cells are selected with appropriate band gaps to efficiently create photovoltage from a larger portion of the solar spectrum. In this regard, one semiconductor cell in each embodiment of the solar cell device has a band gap between that of Ge and GaAs. To achieve desired band gaps and lattice constants, the semiconductor cells may be fabricated from a number of materials including Ge, GaInP, GaAs, GaInAsP, GaInAsN, GaAsGe, BGaInAs, (GaAs)Ge, CuInSSe, CuAsSSe, and GaInAsNP. To further increase efficiency, the thickness of each semiconductor cell is controlled to match the photocurrent generated in each cell. To facilitate photocurrent flow, a plurality of tunnel junctions of low-resistivity material are included between each adjacent semiconductor cell. The conductivity or direction of photocurrent in the solar cell device may be selected by controlling the specific p-type or n-type characteristics for each active junction.

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO); Friedman, Daniel J. (Lakewood, CO)

2001-01-01T23:59:59.000Z

130

Highly polarized emission in spin resolved photoelectron spectroscopy of alpha-Fe(001)/GaAs(001)  

SciTech Connect

Highly spin-polarized sources of electrons, Integrated into device design, remain of great interest to the spintronic and magneto-electronic device community Here, the growth of Fe upon GaAs(001) has been studied with photoelectron spectroscopy (PES), including Spin Resolved PES. Despite evidence of atomic level disorder such as intermixing, an over-layer with the spectroscopic signature of alpha-Fe(001), with a bcc real space ordering, Is obtained The results will be discussed in light of the possibility of using such films as a spin-polarized source in device applications.

Tobin, James; Yu, Sung Woo; Morton, Simon; Waddill, George; Thompson, Jamie; Neal, James; Spangenberg, Matthais; Shen, T.H.

2009-05-19T23:59:59.000Z

131

The Influence of High-Energy Lithium Ion Irradiation on Electrical Characteristics of Silicon and GaAs Solar Cells  

E-Print Network (OSTI)

Space-grade Si and GaAs solar cells were irradiated with 15 & 40 MeV Li ions. Illuminated (AM0 condition) and unilluminated I-V curves reveal that the effect of high-energy Li ion irradiation has produced similar effects to that of proton irradiation. However, an additional, and different, defect mechanism is suggested to dominate in the heavier-ion results. Comparison is made with proton-irradiated solar-cell work and with non-ionizing energy-loss (NIEL) radiation-damage models.

B. Jayashree; Ramani; M. C. Radhakrishna; Anil Agrawal; Saif Ahmad Khan; A. Meulenberg

2006-10-20T23:59:59.000Z

132

Direct measurement of the spin gaps in a gated GaAs two-dimensional electron gas  

E-Print Network (OSTI)

. For the low-field regime where ?s destroyed by the disorder, and there is no spin-splitting for the magnetic field less than Bc. As shown in Figure 7, the ‘spin gap’ measured by the conventional activation energy studies... linearly to zero at a critical magnetic field Bc ~ 3.47 T. The spin gap is expected to have the form ?s = g0?BB + Eex = g * ?BB [12], where Eex is the many-body exchange energy which lifts the g-factor from its bare value (0.44 in GaAs) to its enhanced...

Huang, Tsai-Yu; Liang, Chi-Te; Chen, Yang Fang; Simmons, Michelle Y; Kim, Gil-Ho; Ritchie, David A

2013-03-25T23:59:59.000Z

133

AlGaAs/GaAs nano-hetero-epitaxy on a patterned GaAs substrate by MBE  

SciTech Connect

An AlGaAs/GaAs resonant tunneling diode (RTD) with submicron size was fabricated on {l_brace}111{r_brace} oblique facets of GaAs with selective MBE. The method is based on the fact that a certain facet structure is formed on a patterned substrate in selective MBE because the growth rate depends strongly on the facet structure. The fabrication of a double-barrier structure was attempted on a {l_brace}111{r_brace}B facet. The current-voltage characteristics of the sample showed negative differential resistance at 77K demonstrating that we have achieved an RTD on a submicron facet.

Nishiwaki, T.; Yamaguchi, M.; Sawaki, N. [Department of Electronics, Nagoya University, Chikusa-ku, Nagoya, 464-8603 (Japan)

2007-04-10T23:59:59.000Z

134

Outdoor Testing of GaInP2/GaAs Tandem Cells with Top Cell Thickness Varied  

DOE Green Energy (OSTI)

In this study, we measure the performance of GaInP2/GaAs tandem cells under direct beam sunlight outdoors in order to quantify their sensitivity to both spectral variation and GaInP2 top-cell thickness. A set of cells with five different top-cell thicknesses was mounted on a two-axis tracker with the incident sunlight collimated to exclude all except the direct beam. Current-voltage (I-V) curves were taken throughout the course of several days, along with measurements of the direct solar spectrum. Our two major conclusions are: (1) GaInP2/GaAs tandem cells designed for either the ASTM G-173 direct (G-173D) spectrum or the "air mass 1.5 global" (AM1.5G) spectrum perform the best, and (2) cells can be characterized indoors and modeled using outdoor spectra with the same result. These results are equally valid for GaInP2/GaAs/Ge triple-junction cells.

McMahon, W. E.; Emergy, K. E.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S.; Kramer, C. M.; Duda, A.; Kurtz, S.

2005-08-01T23:59:59.000Z

135

On-Sun Comparison of GaInP2/GaAs Tandem Cells with Top Cell Thickness Varied  

DOE Green Energy (OSTI)

This study compares the on-sun performance of a set of GaInP2/GaAs tandem cells with different GaInP2 top-cell thicknesses. Because high-efficiency III-V cells are best suited to concentrating photovoltaic (CPV) applications, the cells were mounted on a two-axis tracker with the incident sunlight collimated to exclude all except the direct beam. Current-voltage (I-V) curves were taken throughout the course of several days, along with measurements of the direct solar spectrum. Our two major conclusions are: (1) GaInP2/GaAs tandem cells designed for an ''air mass 1.5 global'' (AM 1.5G) or a ''low aerosol optical depth'' (Low AOD) spectrum perform the best, and (2) cells can be characterized indoors and modeled using outdoor spectra to predict the correct result. These results are equally valid for GaInP2/GaAs/Ge triple-junction cells.

McMahon, W. E.; Emery, K. E.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S.; Kramer, C. M.; Duda, A.; Kurtz, S.

2005-02-01T23:59:59.000Z

136

Photovoltaic Single-Crystalline, Thin-Film Cell Basics | Department of  

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

Single-Crystalline, Thin-Film Cell Basics Single-Crystalline, Thin-Film Cell Basics Photovoltaic Single-Crystalline, Thin-Film Cell Basics August 20, 2013 - 2:50pm Addthis Single-crystalline thin films are made from gallium arsenide (GaAs), a compound semiconductor that is a mixture of gallium and arsenic. Gallium arsenide (GaAs) is a compound semiconductor, a mixture of gallium and arsenic. Gallium is a byproduct of the smelting of other metals, notably aluminum and zinc, and it is rarer than gold. Arsenic is not rare, but it is poisonous. Gallium arsenide has been developed for use in solar cells at about the same time that it has been developed for light-emitting diodes, lasers, and other electronic devices that use light. GaAs solar cells offer several benefits: The GaAs bandgap is 1.43 eV-nearly ideal for single-junction solar

137

C-V characteristics of epitaxial germanium metal-oxide-semiconductor capacitor on GaAs substrate with ALD Al2O3 dielectric  

Science Conference Proceedings (OSTI)

Epitaxial germanium metal-oxide-semiconductor capacitors (MOSCAP) were fabricated on GaAs substrate using atomic layer deposited Al"2O"3 gate dielectric with surface treatments including pure HF and HF plus rapid thermal oxidation (RTO). The electrical ... Keywords: ALD Al2O3, CMOS integration, Ge MOSCAP, Ge epitaxial film, RTO

Shih Hsuan Tang; Chien I. Kuo; Hai Dang Trinh; Mantu Hudait; Edward Yi Chang; Ching Yi Hsu; Yung Hsuan Su; Guang-Li Luo; Hong Quan Nguyen

2012-09-01T23:59:59.000Z

138

Interfaces of high-k dielectrics on GaAs: Their common features and the relationship with Fermi level pinning (Invited Paper)  

Science Conference Proceedings (OSTI)

Numerous metal oxides have been studied worldwide as possible high-k gate dielectric candidates for MOS devices on alternative semiconductor materials (Ge, III/V compounds). We will discuss thermal and plasma-enhanced atomic layer deposition (ALD) of ... Keywords: Atomic layer deposition ALD, Atomistic modeling, GaAs MOS, High-k

Matty Caymax; Guy Brammertz; Annelies Delabie; Sonja Sioncke; Dennis Lin; Marco Scarrozza; Geoffrey Pourtois; Wei-E Wang; Marc Meuris; Marc Heyns

2009-07-01T23:59:59.000Z

139

Electrical properties and interfacial chemical environments of in situ atomic layer deposited Al2O3 on freshly molecular beam epitaxy grown GaAs  

Science Conference Proceedings (OSTI)

Interfacial chemical analyses and electrical characterization of in situ atomic layer deposited (ALD) Al"2O"3 on freshly molecular beam epitaxy (MBE) grown n- and p- GaAs (001) with a (4x6) surface reconstruction are performed. The capacitance-voltage ... Keywords: Atomic layer deposition, III-V compound semiconductor, Molecular beam epitaxy

Y. H. Chang; M. L. Huang; P. Chang; C. A. Lin; Y. J. Chu; B. R. Chen; C. L. Hsu; J. Kwo; T. W. Pi; M. Hong

2011-04-01T23:59:59.000Z

140

SUPPRESSION OF ANTIPHASE DISORDER IN GaAs GROWN ON RELAXED GeSi BUFFERS BY METAL-ORGANIC CHEMICAL VAPOR DEPOSITION  

E-Print Network (OSTI)

sublattices, the zinc-blende crystal structure possesses lower symmetry than the diamond cubic structure of wrong nearest-neighbor bonds, they are electrically active defects responsible for scattering and non of antiphase disorder requires control of the substrate surface structure prior to GaAs growth. The usage

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Optical anisotropy of GaSb type-II nanorods on vicinal (111)B GaAs  

SciTech Connect

We form self-assembled GaSb type-II nanorods on a vicinal (111)B GaAs substrate by molecular beam epitaxy and study their optical anisotropy. The GaSb nanorods are elongated and aligned along the [-1 0 1] direction, where the average length, width, and height are about 84, 30, and 2.5 nm. In polarized photoluminescence (PL) measurements, the peak of the GaSb nanorods is observed at about 1.1 eV, where the PL intensity is largest for the [-1 0 1] polarization and smallest for the polarization perpendicular to it. The degree of polarization is more than 20% and depends on the recombination energy. By comparing with a theoretical model based on 4 x 4 Luttinger-Kohn Hamiltonian, we find that the experimental results are explained by considering the Sb/As inter-diffusion and the nanorod height distribution.

Kawazu, Takuya; Noda, Takeshi; Mano, Takaaki; Sakuma, Yoshiki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Akiyama, Yoshihiro [Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya (Japan); Sakaki, Hiroyuki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya (Japan)

2011-12-05T23:59:59.000Z

142

Quaternary Bismide Alloy ByGa1-yAs1-xBix Lattice Matched to GaAs  

DOE Green Energy (OSTI)

We report on the lattice matched quaternary alloy, B{sub y}Ga{sub 1-y}As{sub 1-x}Bi{sub x} grown by molecular beam epitaxy at conditions conducive to bismuth incorporation. Incorporating a smaller atom (boron) along with the larger atom (bismuth) allows for a reduction of the epi-layer strain and lattice matching to GaAs for compositions of Bi:B{approx_equal}1.3:1. The addition of boron flux does not significantly affect the bismuth incorporation and no change in the band gap energy is observed with increasing boron content. However, excess, non-substitutional boron is incorporated which leads to an increase in hole density, as well as an increase in the density of shallow in-gap states as observed by the loss of localization of photo-excited excitons.

Deaton, D. A.; Ptak, A. J.; Alberi, K.; Mascarenhas, A.

2012-07-15T23:59:59.000Z

143

Effects of laser irradiation on the self-assembly of MnAs nanoparticles in a GaAs matrix  

SciTech Connect

We investigate the effects of laser irradiation on the self-assembly of MnAs nanoparticles during solid-phase decomposition in a GaAs matrix. It is found that laser irradiation suppresses the growth of MnAs nanoparticles from small to large size, and that the median diameter D{sub 1} in the size distribution of small MnAs nanoparticles depends on the incident photon energy E following D{sub 1} {approx} E{sup -1/5}. We explain this behavior by the desorption of Mn atoms on the MnAs nanoparticle surface due to resonant optical absorption, in which incident photons excite intersubband electronic transitions between the quantized energy levels in the MnAs nanoparticles.

Hai, Pham Nam; Nomura, Wataru [Department of Electrical Engineering and Information Systems, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Yatsui, Takashi; Ohtsu, Motoichi; Tanaka, Masaaki [Department of Electrical Engineering and Information Systems, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Nanophotonics Research Center, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2012-11-05T23:59:59.000Z

144

Structural and magnetic properties of MnAs nanoclusters formed by Mn ion implantation in GaAs  

SciTech Connect

Ferromagnetic (FM) nanostructures embedded in semiconductors are of fundamental interest since their physical properties could be used in new devices such as memories, sensors or spintronics. In this work, we present results obtained on the synthesis and characterization of nanosized MnAs ferromagnets buried in GaAs. These nanocrystals are formed either by single Mn implantation or Mn + As co-implantation at room temperature into GaAs wafers at 141 and 180 keV respectively. Two doses, 1 x 10{sup 16} and 2 x 10{sup 16} ions {center_dot} cm{sup -2} for each impurity, are tested. Pieces of the wafers are then annealed by RTA or classical furnace annealing at various temperatures under N{sub 2} atmosphere for increasing times. HRTEM and diffraction analysis show that under such conditions MnAs precipitates form with a regular hexagonal structure, the 3m orientation-relationship of precipitates with respect to the matrix offers the most energetically stable configuration. Size distributions are systematically extracted from statistical analysis of ''2 beam'' TEM images. The precipitate mean diameters of nanocrystals populations range from 9 to 13 nm depending on the annealing conditions. Magnetization measurements by SQUID magnetometry on the same samples reveal a progressive transition from a superparamagnetic behavior at room temperature to an FM one at 2K, reflecting a distribution of blocking temperature, due to distribution of size and to dipolar interactions. Curie temperatures in the range of 360K were measured.

Serres, A.; Benassayag, G.; Respaud, M.; Armand, C.; Pesant, J.C.; Mari, A.; Liliental-Weber, Z.; Claverie, A.

2002-08-01T23:59:59.000Z

145

Molecular Beam Epitaxial Growth of Bi2Te3 and Sb2Te3 Topological Insulators on GaAs (111) Substrates: A Potential Route to Fabricate Topological Insulator p-n Junction  

E-Print Network (OSTI)

High quality Bi2Te3 and Sb2Te3 topological insulators films were epitaxially grown on GaAs (111) substrate using solid source molecular beam epitaxy. Their growth and behavior on both vicinal and non-vicinal GaAs (111) substrates were investigated by reflection high-energy electron diffraction, atomic force microscopy, x-ray diffraction, and high resolution transmission electron microscopy. It is found that non-vicinal GaAs (111) substrate is better than a vicinal substrate to provide high quality Bi2Te3 and Sb2Te3 films. Hall and magnetoresistance measurements indicate that p type Sb2Te3 and n type Bi2Te3 topological insulator films can be directly grown on a GaAs (111) substrate, which may pave a way to fabricate topological insulator p-n junction on the same substrate, compatible with the fabrication process of present semiconductor optoelectronic devices.

Zhaoquan Zeng; Timothy A. Morgan; Dongsheng Fan; Chen Li; Yusuke Hirono; Xian Hu; Yanfei Zhao; Joon Sue Lee; Zhiming M. Wang; Jian Wang; Shuiqing Yu; Michael E. Hawkridge; Mourad Benamara; Gregory J. Salamo

2013-01-03T23:59:59.000Z

146

Electrically active Er doping in InAs, In{sub 0.53}Ga{sub 0.47}As, and GaAs  

SciTech Connect

The electron concentration in dilute alloys of Er in GaAs, In{sub 0.53}Ga{sub 0.47}As, and InAs grown by molecular beam epitaxy is studied as a function of Er concentration and In content. Using first-principles calculations based on hybrid density functional theory, we attribute an observed increase in conduction electron concentration to Er incorporation on interstitial sites. Er also incorporates on substitutional sites where it is isovalent and electrically inactive. The formation energy of interstitial Er in InAs is significantly smaller than in GaAs, allowing for more electrically active Er in InAs. The results provide insight into characteristics of rare-earth elements as dopants in semiconductors.

Burke, Peter G.; Ismer, Lars; Lu Hong; Frantz, Elan; Janotti, Anderson; Van de Walle, Chris G.; Bowers, John E.; Gossard, Arthur C. [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

2012-12-03T23:59:59.000Z

147

Metal organic chemical vapor deposition of 111-v compounds on silicon  

DOE Patents (OSTI)

Expitaxial composite comprising thin films of a Group III-V compound semiconductor such as gallium arsenide (GaAs) or gallium aluminum arsenide (GaAlAs) on single crystal silicon substrates are disclosed. Also disclosed is a process for manufacturing, by chemical deposition from the vapor phase, epitaxial composites as above described, and to semiconductor devices based on such epitaxial composites. The composites have particular utility for use in making light sensitive solid state solar cells.

Vernon, Stanley M. (Wellesley, MA)

1986-01-01T23:59:59.000Z

148

Time-evolution of the GaAs(0 0 1) pre-roughening process Z. Ding a,*, D.W. Bullock a  

E-Print Network (OSTI)

Time-evolution of the GaAs(0 0 1) pre-roughening process Z. Ding a,*, D.W. Bullock a , P.M. Thibado) 254. [9] J. Tersoff, M.D. Johnson, B.G. Orr, Phys. Rev. Lett. 78 (1997) 282. [10] V.P. LaBella, D.W.M. Thibado, G.J. Salamo, Y. Baharav, J. Vac. Sci. Technol. B 17 (1999) 253. [12] J.B. Smathers, D.W. Bullock

Thibado, Paul M.

149

GALLIUM ARSENIDE SEMICONDUCTOR-BASED NEUTRON DETECTOR  

NEUTRON DETECTOR BENEFITS Portable, ... High Flux Isotope Reactor and Spallation Neutron Source. Several Homeland Security. LINKS TO ONLINE ...

150

Final Technical Progress Report: High-Efficiency Low-Cost Thin-Film GaAs Photovoltaic Module Development Program; July 14, 2010 - January 13, 2012  

DOE Green Energy (OSTI)

This is the final technical progress report of the High-Efficiency Low-Cost Thin-Film GaAs Photovoltaic Module Development Program. Alta Devices has successfully completed all milestones and deliverables established as part of the NREL PV incubator program. During the 18 months of this program, Alta has proven all key processes required to commercialize its solar module product. The incubator focus was on back end process steps directed at conversion of Alta's high quality solar film into high efficiency 1-sun PV modules. This report describes all program deliverables and the work behind each accomplishment.

Mattos, L.

2012-03-01T23:59:59.000Z

151

2 {mu}m laterally coupled distributed-feedback GaSb-based metamorphic laser grown on a GaAs substrate  

SciTech Connect

We report a type-I GaSb-based laterally coupled distributed-feedback (DFB) laser grown on a GaAs substrate operating continuous wave at room temperature. The laser structure was designed to operate near a wavelength of 2 {mu}m and was grown metamorphically with solid-source molecular beam epitaxy. The device was fabricated using a 6th-order deep etch grating structure as part of the sidewalls of the narrow ridge waveguide. The DFB laser emits total output power of up to 40 mW in a single longitudinal mode operation at a heat-sink temperature of 20 Degree-Sign C.

Apiratikul, P.; He, L.; Richardson, C. J. K. [Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740 (United States)] [Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740 (United States)

2013-06-10T23:59:59.000Z

152

InGaAsN Solar Cells with 1.0eV Bandgap, Lattice Matched to GaAs  

DOE Green Energy (OSTI)

The design, growth by metal-organic chemical vapor deposition, and processing of an In{sub 0.07}Ga{sub 0.93}As{sub 0.98}N{sub 0.02} solar Al, with 1.0 ev bandgap, lattice matched to GaAs is described. The hole diffusion length in annealed, n-type InGaAsN is 0.6-0.8 pm, and solar cell internal quantum efficiencies > 70% arc obwined. Optical studies indicate that defects or impurities, from InGAsN doping and nitrogen incorporation, limit solar cell performance.

Allerman, A.A.; Banas, J.J.; Gee, J.M.; Hammons, B.E.; Jones, E.D.; Kurtz, S.R.

1998-11-24T23:59:59.000Z

153

Growth and Properties of the Dilute Bismide Semiconductor GaAs1-xBix a Complementary Alloy to the Dilute Nitrides  

DOE Green Energy (OSTI)

In this review we describe the growth and properties of the dilute bismide semiconductor alloy GaAs{sub 1-x}Bi{sub x} and show how its properties are in certain respects complementary to the dilute nitride alloy, GaN{sub y}As{sub 1-y}. Like the dilute nitrides the dilute bismides show a giant band gap bowing effect in which a small concentration of the alloying element has a disproportionate effect on the band gap, however in the case of the bismide the band gap reduction is associated with an increase in the energy of the valence band maximum (VBM) rather than a reduction in the energy of the conduction band minimum (CBM). Under standard GaAs growth conditions Bi acts as a surfactant with associated improvements in surface quality. In order to incorporate Bi, growth temperatures below 400 C are used with As{sub 2}/Ga flux ratios close to unity. The electron mobility of GaAs is only weakly affected by Bi alloying, in contrast to the dilute nitrides where the electron mobility decreases rapidly with N alloying. Bi alloying also produces a giant bowing effect in the spin orbit splitting in the valence band. Strong room temperature photoluminescence is observed. Prospects for future device applications of this new compound semiconductor alloy are discussed.

Tiedje, T.; Young, E. C.; Mascarenhas, A.

2008-01-01T23:59:59.000Z

154

On-Sun Comparison of GaInP2/GaAs Tandem Cells with Top-Cell Thickness Varied  

DOE Green Energy (OSTI)

This study compares the on-sun performance of a set of GaInP2/GaAs tandem cells with different GaInP2 top-cell thicknesses. Because high-efficiency III-V cells are best suited to concentrating photovoltaic (CPV) applications, the cells were mounted on a two-axis tracker with the incident sunlight collimated to exclude all except the direct beam. Current-voltage (I-V) curves were taken throughout the course of several days, along with the direct solar spectrum. Our two major conclusions are: (1) GaInP2/GaAs tandem cells designed for an ''air mass 1.5 global'' (AM 1.5G) or a ''low aerosol optical depth'' (Low AOD) spectrum perform the best, and (2) a simple device model using the measured direct spectra as an input gives the same result. These results are equally valid for GaInP2/GaAs/Ge triple-junction cells.

McMahon, W. E.; Emery, K. A.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S.; Kramer, C. M.; Duda, A.; Kurtz, S.

2005-01-01T23:59:59.000Z

155

Activated Carbon and FGD Gypsum Standard Reference ...  

Science Conference Proceedings (OSTI)

... have been effectively reduced in recent years, but atmospheric emissions of mercury from the operation of coal-fired power plants still remain the ...

2012-10-01T23:59:59.000Z

156

The effect of encapsulation on the morphology and chemical composition of InAs/GaAs quantum dots grown by molecular beam epitaxy  

Science Conference Proceedings (OSTI)

In order to fabricate an effective device structure based on InAs quantum dots (QDs), the QD layers must be encapsulated within a matrix that has a wider band gap. This encapsulation is usually achieved by the overgrowth of GaAs. Coherent strained InAs/GaAs ... Keywords: encapsulation, indium arsenide, quantum dots, transmission electron microscopy

D. Zhi; M. Wei; R. E. Dunin-Borkowski; P. A. Midgley; D. W. Pashley; T. S. Jones; B. A. Joyce; P. F. Fewster; P. J. Goodhew

2004-06-01T23:59:59.000Z

157

Electron mobility and effective mass in composite InGaAs quantum wells with InAs and GaAs nanoinserts  

Science Conference Proceedings (OSTI)

The paper is concerned with the theoretical and experimental studies of the band structure and electrical properties of InAlAs/InGaAs/InAlAs/InP heterostructures containing a composite InGaAs quantum well with InAs and GaAs nanoinserts. From the Shubnikov-de Haas effect, the effective cyclotron mass m{sub c}* is determined experimentally and calculated with consideration for the nonparabolicity of the electron energy spectrum. An approach to estimation of the effective mass is proposed and tested. The approach is based on weighted averaging of the m{sub c}* of the composite quantum well's constituent materials. A first proposed heterostructure containing two InAs inserts symmetrically arranged in the quantum well makes a 26% reduction in m{sub c}* compared to m{sub c}* in the lattice-matched In{sub 0.53}Ga{sub 0.47}As quantum well possible.

Ponomarev, D. S., E-mail: ponomarev_dmitr@mail.ru; Vasil'evskii, I. S. [National Nuclear Research University 'Moscow Engineering Physics Institute (MEPhI)' (Russian Federation); Galiev, G. B.; Klimov, E. A. [Russian Academy of Sciences, Institute of Ultrahigh-Frequency Semiconductor Electronics (Russian Federation); Khabibullin, R. A. [National Nuclear Research University 'Moscow Engineering Physics Institute (MEPhI)' (Russian Federation); Kulbachinskii, V. A.; Uzeeva, N. A. [Moscow State University (Russian Federation)

2012-04-15T23:59:59.000Z

158

Transport and strain relaxation in wurtzite InAs-GaAs core-shell heterowires  

Science Conference Proceedings (OSTI)

Indium-arsenide-gallium-arsenide (InAs-GaAs) core-shell, wurtzite nanowires have been grown on GaAs (001) substrates. The core-shell geometries (core radii 11 to 26 nm, shell thickness >2.5 nm) exceeded equilibrium critical values for strain relaxation via dislocations, apparent from transmission electron microscopy. Partial axial relaxation is detected in all nanowires increasing exponentially with size, while radial strain relaxation is >90%, but undetected in nanowires with both smaller core radii electron field-effect mobility compared to bare InAs nanowires.

Kavanagh, Karen L. [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Salfi, Joe; Savelyev, Igor; Blumin, Marina; Ruda, Harry E. [Centre for Advanced Nanotechnology, University of Toronto, 170 College Street, Toronto, Ontario M5S 3E4 (Canada)

2011-04-11T23:59:59.000Z

159

Determination of bandgap states in p-type In[subscript 0.49]Ga[subscript 0.51]P grown on SiGe/Si and GaAs by deep level optical spectroscopy and deep level transient spectroscopy  

E-Print Network (OSTI)

The presence and properties of traps in p-type In[subscript 0.49]Ga[subscript 0.51]P grown on low dislocation density, metamorphic Ge/SiGe/Si substrates and GaAs substrates were determined using deep level transient ...

Gonza?lez, M.

160

Boron arsenide thin film solar cell development. Final report  

DOE Green Energy (OSTI)

Pyrolytic decomposition of diborane and arsine has been used in attempts to grow polycrystalline BAs films. This method, however, produced only amorphous films for deposition temperatures below 920/sup 0/C and polycrystalline boron subarsenide (B/sub 12/As/sub 2/) flms for deposition temperatures above this value. The amorphous films have been determined to have a significant arsenic content but the actual stoichiometry was not obtained. The films were adherent on single crystal sapphire (0001), (111) silicon, (0001) SiC, and polycrystalline SiC but were found not to be adherent to substrates of fused quartz, tungsten, and molybdenum. It was also found that all films deposited above 650/sup 0/C were p-type while those deposited below 600/sup 0/C were usually n-type. Polycrystalline BAs and B/sub 12/As/sub 2/ was produced by reaction of the elements in a closed tube. The amorphous films showed an indirect or non-direct optical bandgap from 1.0 to 1.7 eV with the most probable values between 1.2 to 1.4 eV. The crystalline BAs powder shows a bandgap near 1.0 eV. Photoconductance time constants have been measured for films deposited on (0001) sapphire and (0001) SiC. Attempts at doping the amorphous films were generally unsuccessful. A polycrystalline powder sample was successfully doped with sulfur. Attempts were made to produce a Schottky barrier diode by evaporating Al dots onto an amorphous film on graphite without a post-evaporation anneal. An MIS structure was also attempted by baking an amorphous film in air at 280/sup 0/C before evaporation of aluminum. Although nonlinear characteristics were obtained, none of the devices showed any photovoltaic response. A p-type amorphous film was deposited on an n-type silicon substrate to form a p-n heterojunction. This device did exhibit a photovoltaic response but it is believed that the photogeneration was occurring primarily in the silicon substrate.

Boone, J.L.; Van Doren, T.P.

1980-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


161

R6, Low Field Electron Transport in Mixed Arsenide Antimonide ...  

Science Conference Proceedings (OSTI)

Mixed anion InAsySb1-y quantum wells (QW) with high electron mobility are excellent candidates for direct integration with high hole ...

162

Session B: Gallium Arsenide Processing Room: University Center ...  

Science Conference Proceedings (OSTI)

We report thin film InP based resonant tunneling diodes (RTD) and tunneling hot electron transfer amplifiers (THETA) contact bonded to silicon substates.

163

New Limestone-Gypsum Flue Gas Desulfuization Technology  

Science Conference Proceedings (OSTI)

A new wet FGD processes which SO2 was absorbed in the spray tower using granular limestone simultaneously adding acetic acid had been proposed. The main difference compared to conventional wet FGD process was to utilize granular limestone directly as ... Keywords: new wet FGD, bubbling reactor, granular limestone, acetic acid, SO2

Sheng-yu Liu; Bin Qu; Jin Gao; Jian-ying Liu; Zhi-xiang Ye; Cheng-hua Xu

2009-10-01T23:59:59.000Z

164

Molecular beam epitaxial growth of metamorphic AlInSb/GaInSb high-electron-mobility-transistor structures on GaAs substrates for low power and high frequency applications  

Science Conference Proceedings (OSTI)

We report on molecular beam epitaxial growth of AlInSb/GaInSb metamorphic high-electron-mobility-transistor structures for low power, high frequency applications on 4 in. GaAs substrates. The structures consist of a Ga{sub 0.4}In{sub 0.6}Sb channel embedded in Al{sub 0.4}In{sub 0.6}Sb barrier layers which are grown on top of an insulating metamorphic buffer, which is based on the linear exchange of Ga versus In and a subsequent exchange of As versus Sb. Precise control of group V fluxes and substrate temperature in the Al{sub 0.4}In{sub 0.6}As{sub 1-x}Sb{sub x} buffer is essential to achieve high quality device structures. Good morphological properties were achieved demonstrated by the appearance of crosshatching and root mean square roughness values of 2.0 nm. Buffer isolation is found to be >100 k{Omega}/{open_square} for optimized growth conditions. Hall measurements at room temperature reveal electron densities of 2.8x10{sup 12} cm{sup -2} in the channel at mobility values of 21.000 cm{sup 2}/V s for single-sided Te volume doping and 5.4x10{sup 12} cm{sup -2} and 17.000 cm{sup 2}/V s for double-sided Te {delta}-doping, respectively.

Loesch, R.; Aidam, R.; Kirste, L.; Leuther, A. [Fraunhofer Institute for Applied Solid-State Physics (IAF), Tullastrasse 72, 79108 Freiburg (Germany)

2011-02-01T23:59:59.000Z

165

InGaAsN/GaAs heterojunction for multi-junction solar cells  

DOE Patents (OSTI)

An InGaAsN/GaAs semiconductor p-n heterojunction is disclosed for use in forming a 0.95-1.2 eV bandgap photodetector with application for use in high-efficiency multi-junction solar cells. The InGaAsN/GaAs p-n heterojunction is formed by epitaxially growing on a gallium arsenide (GaAs) or germanium (Ge) substrate an n-type indium gallium arsenide nitride (InGaAsN) layer having a semiconductor alloy composition In.sub.x Ga.sub.1-x As.sub.1-y N.sub.y with 0GaAs layer, with the InGaAsN and GaAs layers being lattice-matched to the substrate. The InGaAsN/GaAs p-n heterojunction can be epitaxially grown by either molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD). The InGaAsN/GaAs p-n heterojunction provides a high open-circuit voltage of up to 0.62 volts and an internal quantum efficiency of >70%.

Kurtz, Steven R. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM); Klem, John F. (Albuquerque, NM); Jones, Eric D. (Edgewood, NM)

2001-01-01T23:59:59.000Z

166

Argonne CNM Highlight: Superhydrophobicity on Silver Nanoplates  

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

Superhydrophobicity on Silver Nanoplates Superhydrophobicity on Silver Nanoplates Superhydrophobic silver nanoplates Representations of water droplets on a GaAs substrate covered with the Ag nanoplates; as featured on back cover of the journal issue Gallium arsenide wafers decorated with silver nanoplates result in composite surfaces of varying hydrophobocity. CNM researchers and collaborators at Clemson have accomplished this in part by coating the silver nanoplates with self-assembled monolayers of alkyl thiol molecules. By carefully controlling reaction conditions, the size, thickness, and surface roughness of the individual silver nanoplates are tuned to produce different topographic structures and roughness of the composite surfaces. This in turn influences the surface hydrophobicity. The composite surfaces

167

Electronic structure of BAs and boride III-V alloys  

SciTech Connect

Boron arsenide, the typically ignored member of the Group-III--V arsenide series BAs-AlAs-GaAs-InAs is found to resemble silicon electronically: its {Gamma} conduction-band minimum is p-like ({Gamma}{sub 15}), not s-like ({Gamma}{sub 1c}), it has an X{sub 1c}-like indirect band gap, and its bond charge is distributed almost equally on the two atoms in the unit cell, exhibiting nearly perfect covalency. The reasons for these are tracked down to the anomalously low atomic p orbital energy in the boron and to the unusually strong s--s repulsion in BAs relative to most other Group-III--V compounds. We find unexpected valence-band offsets of BAs with respect to GaAs and AlAs. The valence-band maximum (VBM) of BAs is significantly higher than that of AlAs, despite the much smaller bond length of BAs, and the VBM of GaAs is only slightly higher than in BAs. These effects result from the unusually strong mixing of the cation and anion states at the VBM. For the BAs-GaAs alloys, we find (i) a relatively small ({approx}3.5 eV) and composition-independent band-gap bowing. This means that while addition of small amounts of nitrogen to GaAs lowers the gap, addition of small amounts of boron to GaAs raises the gap; (ii) boron ''semilocalized'' states in the conduction band (similar to those in GaN-GaAs alloys); and (iii) bulk mixing enthalpies that are smaller than in GaN-GaAs alloys. The unique features of boride Group-III--V alloys offer new opportunities in band-gap engineering.

Hart, Gus L. W.; Zunger, Alex

2000-11-15T23:59:59.000Z

168

Electronic structure of BAs and boride III–V alloys  

E-Print Network (OSTI)

Boron arsenide, the typically-ignored member of the III–V arsenide series BAs–AlAs–GaAs– InAs is found to resemble silicon electronically: its ? conduction band minimum is p-like (?15), not s-like (?1c), it has an X1c-like indirect band gap, and its bond charge is distributed almost equally on the two atoms in the unit cell, exhibiting nearly perfect covalency. The reasons for these are tracked down to the anomalously low atomic p orbital energy in the boron and to the unusually strong s–s repulsion in BAs relative to most other III–V compounds. We find unexpected valence band offsets of BAs with respect to GaAs and AlAs. The valence band maximum (VBM) of BAs is significantly higher than that of AlAs, despite the much smaller bond length of BAs, and the VBM of GaAs is only slightly higher than in BAs. These effects result from the unusually strong mixing of the cation and anion states at the VBM. For the BAs–GaAs alloys, we find (i) a relatively small (?3.5 eV) and composition-independent band gap bowing. This means that while addition of small amounts of nitrogen to GaAs lowers the gap, addition of small amounts of boron to GaAs raises the gap (ii) boron “semi-localized” states in the conduction band (similar to those in GaN–GaAs alloys), and (iii) bulk mixing enthalpies which are smaller than in GaN–GaAs alloys. The unique features of boride III–V alloys offer new opportunities in band gap engineering. I.

Gus L. W. Hart; Alex Zunger

2000-01-01T23:59:59.000Z

169

Scanning tunneling optical resonance microscopy applied to indium arsenide quantum dot structures.  

E-Print Network (OSTI)

??The technique of Scanning Tunneling Optical Resonance Microscopy (STORM) has been investigated for use on nanostructures. It has been demonstrated as a viable technique to… (more)

Byrnes, Daniel P.

2008-01-01T23:59:59.000Z

170

Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits  

E-Print Network (OSTI)

New York Master of Science, Electrical Engineering (AppliedYork Bachelor of Science, Electrical Engineering RochesterElectronic Thin Film Science: For Electrical Engineers and

Bickford, Justin Robert

2008-01-01T23:59:59.000Z

171

Sparse gallium arsenide to silicon metal waferbonding for heterogeneous monolithic microwave integrated circuits  

E-Print Network (OSTI)

and V. I. Tsimbal, “Electrical Resistivity of Pd-In Alloys,”and V. I. Tsimbal, “Electrical Resistivity of Pd-In Alloys,”and V. I. Tsimbal, “Electrical Resistivity of Pd-In Alloys,”

Bickford, Justin Robert

2008-01-01T23:59:59.000Z

172

Magnetism and superconductivi[t]y in Pr-based filled skutterudite arsenides  

E-Print Network (OSTI)

5.4.2 Electrical Resistivity . . . . . . . . . . . . . . .3.2 Electrical Resistivity . . . . . . . . . . . . . .3.2.3 CEF E?ects on Electrical Resistivity . . 3.3

Sayles, Todd Allen

2008-01-01T23:59:59.000Z

173

Socio-economic and Environmental Impact Analysis of Khothagpa Gypsum Mine  

E-Print Network (OSTI)

of marble, quartzite, granite, talc, iron ore, and pink shale. Mining in Bhutan started in the early 1970s and it was mostly carried out by the government enterprises. Gradually under the auspices of policy of privatization, mining sector operations...

Galay, Karma

2008-01-01T23:59:59.000Z

174

Concentration of 226Ra in soil and sugar cane after application of calcareous, gypsum or phosphogypsum.  

E-Print Network (OSTI)

??All kinds of soil possess 226Ra, and its absorption by the plants, depends on the specific characteristics of each region and of the cultivated species.… (more)

Maria Rosely de Oliveira Breckenfeld

2007-01-01T23:59:59.000Z

175

High-efficiency solar cell and method for fabrication  

DOE Patents (OSTI)

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD). 4 figs.

Hou, H.Q.; Reinhardt, K.C.

1999-08-31T23:59:59.000Z

176

High-efficiency solar cell and method for fabrication  

DOE Patents (OSTI)

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

Hou, Hong Q. (Albuquerque, NM); Reinhardt, Kitt C. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

177

Beyond Silicon: Cutting the Costs of Solar Power | U.S. DOE Office of Science (SC)  

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

Beyond Silicon: Cutting the Costs of Solar Power Beyond Silicon: Cutting the Costs of Solar Power Stories of Discovery & Innovation Beyond Silicon: Cutting the Costs of Solar Power Enlarge Photo Courtesy of University of Illinois Mechanically flexible, high efficiency solar module that uses an interconnected array of microscale GaAs photovoltaic cells, grown in a multilayer stack on a wafer and then printed onto a sheet of plastic. Enlarge Photo 04.15.11 Beyond Silicon: Cutting the Costs of Solar Power New method of fabricating semiconductors from gallium arsenide promises more affordable solar power, improved semiconductor devices. The biggest single barrier to widespread adoption of solar power continues to be the cost of solar cells. University of Illinois materials scientists supported by the DOE Office of Science have scored a

178

Spire Semiconductor formerly Bandwidth Semiconductor LLC | Open Energy  

Open Energy Info (EERE)

Semiconductor formerly Bandwidth Semiconductor LLC Semiconductor formerly Bandwidth Semiconductor LLC Jump to: navigation, search Name Spire Semiconductor (formerly Bandwidth Semiconductor LLC) Place Hudson, New Hampshire Zip 3051 Product Spire-owned US-based manufacturer of gallium-arsenide (GaAs) cells; offers design and manufacturing capabilities of concentrator cells. References Spire Semiconductor (formerly Bandwidth Semiconductor LLC)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Spire Semiconductor (formerly Bandwidth Semiconductor LLC) is a company located in Hudson, New Hampshire . References ↑ "Spire Semiconductor (formerly Bandwidth Semiconductor LLC)" Retrieved from "http://en.openei.org/w/index.php?title=Spire_Semiconductor_formerly_Bandwidth_Semiconductor_LLC&oldid=351621"

179

Ion Trap in a Semiconductor Chip  

E-Print Network (OSTI)

The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling and Bose-Einstein condensation of cold gases to the precise quantum control of individual atomic ion. Work on miniaturizing electromagnetic traps to the micrometer scale promises even higher levels of control and reliability. Compared with 'chip traps' for confining neutral atoms, ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass spectrometer arrays, compact atomic clocks, and most notably, large scale quantum information processors. Here we report the operation of a micrometer-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool, and measure heating of a single 111Cd+ ion in an integrated radiofrequency trap etched from a doped gallium arsenide (GaAs) heterostructure.

D. Stick; W. K. Hensinger; S. Olmschenk; M. J. Madsen; K. Schwab; C. Monroe

2006-01-09T23:59:59.000Z

180

Coherence and Spin in GaAs Quantum Dots  

E-Print Network (OSTI)

. The eletrical proper- ties of our thin films on the 101¯0 substrate are comparable with those of a single

Heller, Eric

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Low-energy positron diffraction from GaAs(110)  

Science Conference Proceedings (OSTI)

Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K and analyzed using a multiple scattering model of the low-energy positron diffraction (LEPD) process. Excellent correspondence between the measured and calculated intensities is obtained for a reconstruction that is primarily a bond-length-conserving rotation of the top layer, with As relaxed outward and Ga inward with a tilt angle {omega}{sub 1} = 28.6 {plus minus} 3{degree}, confirming the results of previous structure analyses for this surface. The quality of the description of the measured intensities, as measured by the x-ray {ital R} factor, is significantly better for LEPD than for low-energy electron diffraction. This result is attributed to the repulsive character of the positron-ion core potential and a resulting more surface sensitive diffraction process for LEPD.

Lessor, D.L. (Pacific Northwest Laboratory, K5-17 ISB-1, Richland, Washington 99352 (United States)); Duke, C.B. (Xerox Webster Research Center, 800 Phillips Road, 0114-38D, Webster, New York 14580 (United States)); Chen, X.M.; Brandes, G.R.; Canter, K.F. (Department of Physics, Brandeis University, Waltham, Massachusetts 02254 (United States)); Ford, W.K. (Advanced Materials Center and Department of Physics, Montana State University, Bozeman, Montana 59717 (United States))

1992-07-01T23:59:59.000Z

182

Accelerated aging of GaAs concentrator solar cells  

DOE Green Energy (OSTI)

An accelerated aging study of AlGaAs/GaAs solar cells has been completed. The purpose of the study was to identify the possible degradation mechanisms of AlGaAs/GaAs solar cells in terrestrial applications. Thermal storage tests and accelerated AlGaAs corrosion studies were performed to provide an experimental basis for a statistical analysis of the estimated lifetime. Results of this study suggest that a properly designed and fabricated AlGaAs/GaAs solar cell can be mechanically rugged and environmentally stable with projected lifetimes exceeding 100 years.

Gregory, P.E.

1982-04-01T23:59:59.000Z

183

P2 Coordinators GAA Dist List Oct 06.doc  

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

) Robert (Bruce) Webster webster@netl.doe.gov 412-386-4475 National Petroleum & Oil Shale Reserves (CO, UT, WY) Michael Taylor mike.taylor@rmotc.doe.gov 307-437-9606...

184

Structural and physical properties of layered oxy-arsenides LnRuAsO (Ln=La, Nd, Sm, Gd)  

Science Conference Proceedings (OSTI)

Polycrystalline samples of LaRuAsO, NdRuAsO, SmRuAsO, and GdRuAsO have been synthesized and studied using powder x-ray diffraction, electrical transport, magnetization, and heat capacity measurements. Variations in structural properties across the series reveal a trend toward more ideal tetrahedral coordination around Ru as the size of the rare earth element is reduced. The lattice parameters of these Ru compounds show a more anisotropic response to variation in Ln than their Fe analogs, and significant anisotropy in thermal expansion is also observed. Transport measurements show metallic behavior, and carrier concentrations near 10{sup 21}-10{sup 22} electrons per cm{sup 3} are inferred from simple analysis of Hall effect measurements. Anomalies in resistivity, magnetization, and heat capacity indicate antiferromagnetic ordering of rare earth moments at 5 K for GdRuAsO, 4.5 K for SmRuAsO, and heat capacity of LaRuAsO, NdRuAsO, SmRuAsO, and GdRuAsO. Highlights: Black-Right-Pointing-Pointer Experimental investigation of LaRuAsO, NdRuAsO, SmRuAsO, and GdRuAsO. Black-Right-Pointing-Pointer Anisotropic lattice response to changing Ln radius and temperature. Black-Right-Pointing-Pointer Ru coordination becomes more ideal as Ln radius is reduced. Black-Right-Pointing-Pointer Transport measurements reveal metallic conduction dominated by electrons. Black-Right-Pointing-Pointer Magnetic measurements indicate antiferromagnetic ordering Nd, Sm, and Gd moments.

McGuire, Michael A., E-mail: McGuireMA@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); May, Andrew F.; Sales, Brian C. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2012-07-15T23:59:59.000Z

185

Bismuth in gallium arsenide: Structural and electronic properties of GaAs{sub 1-x}Bi{sub x} alloys  

Science Conference Proceedings (OSTI)

The structural and electronic properties of cubic GaAs{sub 1-x}Bi{sub x} alloys with bismuth concentration 0.0, 0.25, 0.50, 0.75 and 1.0 are studied using the 'special quasi-random structures' (SQS) approach of Zunger along with the generalized gradient approximation (GGA) and the Engel-Vosko generalized gradient approximation (EV-GGA). The lattice constant, bulk modulus, derivative of bulk modulus and energy gap vary with bismuth concentration nonlinearly. The present calculations show that the band gap decreases substantially with increasing bismuth concentration and that spin-orbit coupling influences the nature of bonding at high Bi concentrations. - Graphical abstract: Bowing effect of spin-orbit split-off band values versus Bi content with and without spin-orbit coupling for GaAs{sub 1-x}Bi{sub x} (at x=0.25, 0.50 and 0.75). Calculations are done with GGA. Highlights: Black-Right-Pointing-Pointer Structural and electronic properties of GaAs{sub 1-x}Bi{sub x} alloys were studied. Black-Right-Pointing-Pointer We present results of lattice constant, energy gap, bulk modulus and derivative. Black-Right-Pointing-Pointer The band gap decreases substantially with increasing Bi concentration. Black-Right-Pointing-Pointer Calculations of the density of states and charge densities are also presented. Black-Right-Pointing-Pointer We have performed calculations without and with spin-orbit coupling.

Reshak, Ali Hussain, E-mail: maalidph@yahoo.co.uk [School of Complex Systems, FFWP-South Bohemia University, Nove Hrady 37333 (Czech Republic); School of Material Engineering, Malaysia University of Perlis, P.O Box 77, d/a Pejabat Pos Besar, 01007 Kangar, Perlis (Malaysia); Kamarudin, H. [School of Material Engineering, Malaysia University of Perlis, P.O Box 77, d/a Pejabat Pos Besar, 01007 Kangar, Perlis (Malaysia); Auluck, S. [National Physical Laboratory Dr. KS Krishnan Marg, New Delhi 110012 (India); Kityk, I.V. [Electrical Engineering Department, Technological University of Czestochowa, Al. Armii Krajowej 17/19, Czestochowa (Poland)

2012-02-15T23:59:59.000Z

186

Gypsum scale formation on a heated copper plate under natural convection conditions and produced water remediation technologies review  

E-Print Network (OSTI)

Scaling or crystallization fouling of unwanted salts is one of the most challenging and expensive problems encountered in different applications such as heat exchangers and thermal water treatment technologies. Formation ...

Mirhi, Mohamad H. (Mohamad Hussein)

2013-01-01T23:59:59.000Z

187

Using gypsUm and Other CalCiUm amendments in sOUthwestern sOils  

E-Print Network (OSTI)

materials, waste products of phosphate fertilizer production (phosphogypsum) or from power plant stack

Sanderson, Mike

188

Crystallographic and magnetic phase transitions in the layered ruthenium oxy-arsenides TbRuAsO and DyRuAsO  

Science Conference Proceedings (OSTI)

The crystallographic and physical properties of TbRuAsO and DyRuAsO at and below room temperature are reported, including full structure refinements from powder X-ray diffraction data and measured electrical and thermal transport properties, magnetic susceptibility, and heat capacity. Both compounds are isostructural to LaFeAsO (ZrCuSiAs-type, P4/nmm) at room temperature. However, DyRuAsO undergoes a symmetry-lowering crystallographic phase transition near 25 K, and adopts an orthorhombic structure (Pmmn) below this temperature. This structural distortion is unlike those observed in the analogous Fe compounds. Magnetic phase transitions are observed in both compounds which suggest antiferromagnetic ordering of lanthanide moments occurs near 7.0 K in TbRuAsO and 10.5 K in DyRuAsO. The nature of the structural distortion as well as thermal conductivity and heat capacity behaviors indicate strong coupling between the magnetism and the lattice. The behaviors of both materials show magnetic ordering of small moments on Ru may occur at low temperatures.

McGuire, Michael A [ORNL; May, Andrew F [ORNL; Sales, Brian C [ORNL

2012-01-01T23:59:59.000Z

189

Lattice distortions in layered type arsenides LnTAs{sub 2} (Ln=La-Nd, Sm, Gd, Tb; T=Ag, Au): Crystal structures, electronic and magnetic properties  

SciTech Connect

The lanthanide coinage-metal diarsenides LnTAs{sub 2} (Ln=La, Ce-Nd, Sm; T=Ag, Au) have been reinvestigated and their structures have been refined from single crystal X-ray data. Two different distortion variants of the HfCuSi{sub 2} type are found: PrAgAs{sub 2}, NdAgAs{sub 2}, SmAgAs{sub 2}, GdAgAs{sub 2}, TbAgAs{sub 2}, NdAuAs{sub 2} and SmAuAs{sub 2} crystallize as twofold superstructures in space group Pmcn with the As atoms of their planar layers forming zigzag chains, whereas LaAgAs{sub 2}, CeAgAs{sub 2} and PrAuAs{sub 2} adopt a fourfold superstructure (space group Pmca) with cis-trans chains of As atoms. The respective atomic positions can be derived from the HfCuSi{sub 2} type by group-subgroup relations. The compounds with zigzag chains of As atoms exhibit metallic behaviour while those with cis-trans chains are semiconducting as measured on powder pellets. The majority of the compounds including 4f elements show antiferromagnetic ordering at T{sub N}<20 K. - Text3: Zigzig vs. cis-trans.

Rutzinger, D.; Bartsch, C. [Anorganische Chemie, Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, D-01062 Dresden (Germany); Doerr, M. [Institut fuer Festkoerperphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Rosner, H. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Str. 40, D-01187 Dresden (Germany); Neu, V. [IFW Dresden, Institut fuer metallische Werkstoffe, Helmholtzstr. 20, D-01069 Dresden (Germany); Doert, Th., E-mail: thomas.doert@chemie.tu-dresden.d [Anorganische Chemie, Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, D-01062 Dresden (Germany); Ruck, M. [Anorganische Chemie, Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, D-01062 Dresden (Germany)

2010-03-15T23:59:59.000Z

190

NIST: X-Ray Mass Attenuation Coefficients - Table 4  

Science Conference Proceedings (OSTI)

... Gafchromic Sensor, Tissue-Equivalent Gas, Methane Based. Gallium Arsenide, Tissue-Equivalent Gas, Propane Based. Glass ...

191

Self-organized GaAs patterns on misoriented GaAs (111)B substrates using dilute nitrides by molecular beam epitaxy  

Science Conference Proceedings (OSTI)

Recently, the growth of patterned surfaces is being used to demonstrate the site control of the three-dimensional nanostructures, and in particular quantum dots. Nevertheless the pre-patterning techniques show some disadvantages. In this work, we report ... Keywords: Dilute nitrides, InAs, Molecular beam epitaxy, Patterned surface, Quantum dots

R. Gargallo; J. Miguel-Sánchez; Á. Guzmán; U. Jahn; E. Muñoz

2006-12-01T23:59:59.000Z

192

Size Effect on the Mechanical Behaviour of GaAs Nanowires  

Science Conference Proceedings (OSTI)

Multiple-Stripe Lithiation Mechanism of Individual SnO2 Nanowires in a Flooding Geometry · Multiscale Modeling of Anisotropic Growth in Lithiated Silicon ...

193

Performance of GAASP/GAAS Superlattice Photocathodes in High Energy Experiments using Polarized Electrons  

Science Conference Proceedings (OSTI)

The GaAsP/GaAs strained superlattice photocathode structure has proven to be a significant advance for polarized electron sources operating with high peak currents per microbunch and relatively low duty factor. This is the characteristic type of operation for SLAC and is also planned for the ILC. This superlattice structure was studied at SLAC [1], and an optimum variation was chosen for the final stage of E-158, a high-energy parity violating experiment at SLAC. Following E-158, the polarized source was maintained on standby with the cathode being re-cesiated about once a week while a thermionic gun, which is installed in parallel with the polarized gun, supplied the linac electron beams. However, in the summer of 2005, while the thermionic gun was disabled, the polarized electron source was again used to provide electron beams for the linac. The performance of the photocathode 24 months after its only activation is described and factors making this possible are discussed.

Brachmann, A.; Clendenin, J.E.; Maruyama, T.; Garwin, E.L.; Ioakemidi, K.; Prescott, C.Y.; Turner, J.L.; /SLAC; Prepost, R.; /Wisconsin U., Madison

2006-02-27T23:59:59.000Z

194

F5, Large Area Growth of GaAs Solar Cell Based on Nanowire ...  

Science Conference Proceedings (OSTI)

G2, ZnSnN2: A New Earth-Abundant Semiconductor for Solar Energy Conversion · G3, Electrodeposition of Indium Sulfide Films from Organic Electrolytes.

195

GaAs series connected photovoltaic converters for high voltage capacitor charging applications  

DOE Green Energy (OSTI)

This report describes the design features of series connected photovoltaic arrays which will be required to charge capacitors to relatively high (400V) voltages in time periods on the order of 1 microsecond. The factors which determine the array voltage and the capacitor charge time are given. Individual element junction designs, along with an interconnect scheme, and a semiconductor process to realize them are presented. Finally, the input laser optical required to meet the requirements is determined.

Rose, B.H.

1997-09-01T23:59:59.000Z

196

Development and fabrication of advanced cover glass for a GaAs solar cell  

DOE Green Energy (OSTI)

This report summarizes work on improving solar cell conversion efficiencies by modifying the cell cover glass. Two approaches were investigated during the course of this work: grooved cover glasses to reduce the effect of top contact obscuration and secondary concentrators to improve concentrator solar cell performances in tracking modules. The grooved cover glass work used an array of metallized V shaped grooves in a thin cover glass (plastic) window to deflect incident light rays away from solar cell front surface regions covered by the solar cell electrical contact metallization onto unobstructed, optically active regions of the solar cell. Secondary concentrators are being considered for use on concentrator solar cells to improve overall system conversion efficiency and reduce receiver module cost. Secondary concentrators designed and fabricated during this project consist of small glass cones to attach directly to the top of the receiver solar cell. When appropriately designed, these secondary concentrator glass cones increase sunlight concentration on the solar cell, improve solar flux uniformity on the cell, improve system tolerance to tracking error, and allow for concentration ratios greater than can be ordinarily achieved with acrylic Fresnel lenses.

Borden, P.G.; Kaminar, N.R.; Grounner, M.

1984-01-01T23:59:59.000Z

197

MINORITY CARRIER TRAP MEASUREMENTS IN SCHOTTKY BARRIER S ON N-TYPE LPE GaAs  

E-Print Network (OSTI)

, T. and JEPPSON, B., Japan J. Appl. Phys. 12 (1973) 7. [6] HASEGAWA, F. and MAJERFELD, A., Electron

Paris-Sud XI, Université de

198

P8, Fabrication of Subwavelength Pillar Arrays on GaAs by Confined ...  

Science Conference Proceedings (OSTI)

DD3, A New Approach to Make ZnO-Cu2O Heterojunctions for Solar Cells ... E2, AlGaAs/GaAs/GaN Wafer Fused HBTs with Ar Implanted Extrinsic Collectors.

199

Exciton localization mechanisms in wurtzite/zinc-blende GaAs nanowires  

E-Print Network (OSTI)

, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom 2Laboratoire des Mate´riaux Semiconducteurs, Ecole Polytechnique Fe´de´rale de Lausanne, 1015 Lausanne, Switzerland 3Walter Schottky Institut and Physik Department, Technische... et al. PHYSICAL REVIEW B 87, 125304 (2013) *Corresponding author: pmc53@cam.ac.uk †Present address: IBM Zurich Research Laboratory, CH-8803 Ru¨schlikon, Switzerland. 1P. Caroff, K. A. Dick, J. Johansson, M. E. Messing, K. Deppert, and L. Samuelson...

Graham, Alexandra; Corfdir, Pierre; Heiss, Martin; Conesa-Boj, Sonia; Uccelli, Emanuele; Fontcuberta i Morral, Anna; Phillips, Richard

200

EE5, Growth and Thermal Conductivity of Polycrystalline GaAs ...  

Science Conference Proceedings (OSTI)

A simple yet extensively used configuration for thermal management in high .... Microstructure and Properties of Colloidal ITO Films and Cold-Sputtered ITO Films .... Hybrid Inorganic-Organic Molecular Magnets on an Ultrathin Insulating Film.

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Radiation-induced surface degradation of GaAs and high electron mobility transistor structures  

Science Conference Proceedings (OSTI)

Transistor heterostructures with high-carrier-mobility have been studied. It is shown that, as the {gamma}-irradiation dose {Phi} increases, their degradation occurs in the following sequence. (i) At {Phi} 0.2-eV decrease in the diffusion energy of intrinsic defects and, probably, atmospheric oxygen. (ii) At {Phi} > 10{sup 7} rad, highly structurally disordered regions larger than 1 {mu}m are formed near microscopic defects or dislocations. (iii) At {Phi} > 10{sup 8} rad, there occurs degradation of the internal AlGaAs/InGaAs/GaAs interfaces and the working channel. An effective method for studying the degradation processes in heterostructures is to employ a set of structural diagnostic methods to analyze processes of radiation-induced and aging degradation, in combination with theoretical simulation of the occurring processes.

Bobyl, A. V.; Konnikov, S. G.; Ustinov, V. M.; Baidakova, M. V.; Maleev, N. A.; Sakseev, D. A. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Konakova, R. V., E-mail: konakova@isp.kiev.ua; Milenin, V. V.; Prokopenko, I. V. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine)

2012-06-15T23:59:59.000Z

202

Excitation-Dependent Recombination and Diffusion Near an Isolated Dislocation in GaAs  

DOE Green Energy (OSTI)

In low-magnification, plan-view photoluminescence images of a nominally lattice-matched, undoped GaAs/GaInP heterostructure, we observe a random distribution of isolated dark spots. We attribute the dark spots to crystal dislocations, where nonradiative recombination is augmented by transitions utilizing defect-related energy levels between the conduction and valence bands. We note that, when the laser excitation intensity is reduced, the darkened regions expand. At lower excitation, the density of photogenerated electrons and holes is reduced, and they are more likely to reach the defective region before encountering a partner for radiative recombination. When we model the behavior with a simulation that allows for Laplacian diffusion and defect-related recombination only through mid-bandgap energy levels, we do not obtain good agreement between experimental and simulated images. But if we allow for an arbitrary distribution of defect levels, such that the occupation of the levels and bands can change independently, we have more flexibility for fitting the density-dependent recombination rates. The more sophisticated model produces results that are more consistent with experimental images.

Gfroerer, T. H.; Crowley, C. M.; Read, C. M.; Wanlass, M. W.

2012-06-01T23:59:59.000Z

203

ENVIRONMEWAL PROECTlOH requirements (hat are the subject of Table of -tents AGENCY todav's notice mav not be chall~nsed L DefiniKom  

E-Print Network (OSTI)

. Various approaches, such as application of lime, gypsum, and phosphogypsum, have been used to overcome

204

subr:im bulletin (April 2009)  

E-Print Network (OSTI)

gypsum, phosphogypsum and other phosphate based amendments also have good abilities to adsorb lead. d

205

In Situ Stabilization of Trace Metals in a Copper-Contaminated Soil using P-Spiked Linz-Donawitz Slag  

E-Print Network (OSTI)

(phosphogypsum, desulfogypsum and titan-gypsum for example). Though, some other are still studied, especially

Paris-Sud XI, Université de

206

INTERNATIONONAL INSTITUTE FOR AEROSPACE.SURVEY AND EARTH SCIENCES Atkilt Girma, MSc  

E-Print Network (OSTI)

practices. Common mineral amendments that could be used are: gypsum, phosphogypsum, calcite and other acid

Rossiter, D G "David"

207

Register Closing Effects on Forced Air Heating System Performance  

E-Print Network (OSTI)

with gypsum wallboard and plywood, with carefully tapedenvelope and covered using plywood plates as illustrated in

Walker, Iain S.

2003-01-01T23:59:59.000Z

208

High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application  

DOE Green Energy (OSTI)

The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong potential for net gains in efficiency at high concentration.

Hubbard, Seth

2012-09-12T23:59:59.000Z

209

About the 12th International Conference on Metal Organic Vapor ...  

Science Conference Proceedings (OSTI)

... phosphide based materials; Gallium arsenide based materials; High brightness LEDs and solid state lighting; Growth of device structures: LEDs, laser diodes, ...

210

The role of screening of the electron-phonon interaction in relaxation of photoexcited electron-hole plasma in semiconductors  

Science Conference Proceedings (OSTI)

The role of screening of the interaction of the electron-hole plasma with optical phonons is analytically evaluated by the example of gallium arsenide.

Kumekov, S. E. [Kazakh National Technical University (Kazakhstan)], E-mail: skumekov@mail.ru

2008-08-15T23:59:59.000Z

211

Photoluminescence study of GaAs films on Si(100) grown by atomic hydrogen-assisted molecular beam epitaxy  

Science Conference Proceedings (OSTI)

Keywords: atomic hydrogen-mediated epitaxy, lattice-mismatched heteroepitaxy, minority carrier lifetime, molecular beam epitaxy, photoluminescence decay, solar cells

Yoshitaka Okada; Shigeru Ohta; Akio Kawabata; Hirofumi Shimomura; Mitsuo Kawabe

1994-03-01T23:59:59.000Z

212

J1, MBE Growth of Metamorphic InGaP on GaAs and GaP for Wide ...  

Science Conference Proceedings (OSTI)

I4, Electrical Spin Injection in a Hybrid Organic/Inorganic Spin-Polarized Light Emitting Diode (Spin-LED) · I5, Properties of MnAs/GaMnAs/MnAs Magnetic ...

213

Efficiency-improvement study for GaAs solar cells. Final report, March 31, 1980-September 30, 1981  

DOE Green Energy (OSTI)

High-yield fabrication of good quality AlGaAs/GaAs concentration solar cells has been a limiting factor in widespread utilization of these high conversion efficiency (22 to 24%) photovoltaic cells. Reported is a series of investigations to correlate solar cell yield with substrate quality, growth techniques, layer composition, and metallization processes. In addition, several diagnostic techniques are described to aid in device characterization.

Cape, J.A.; Oliver, J.R.; Zehr, S.W.

1982-04-01T23:59:59.000Z

214

By-Products Utilization  

E-Print Network (OSTI)

.I. has recently established a technology of using a gypsum-containing cementitious material from coal of the cement in concrete mixtures could be replaced with the gypsum wallboard-Class C fly ash blend

Wisconsin-Milwaukee, University of

215

Report Sample 5  

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

tall Fermenter 2 102,000 gallons, 82 feet tall Fermenter 3 73,000 gallons, 82 feet tall Fermentation PLC Building 150 square feet Gypsum and Lime Area Gypsum Filter, Lime...

216

Leaching of CUB Using a CSTX  

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

4 2H 2 O). FGD produced gypsum is mainly used as a substitute for natural gypsum in the manufacturing of wallboard, though it is also be used, to a lesser extent, as a soil...

217

Janet and Grant Brians: Brians Ranch  

E-Print Network (OSTI)

Brians: Well, putting on compost and gypsum have been two ofback in the soil, and compost and things. But we didn’tthen putting gypsum and compost in, gradually it’s getting

Farmer, Ellen

2010-01-01T23:59:59.000Z

218

Institut National Polytechnique de Toulouse (INP Toulouse) Mcanique, Energtique, Gnie civil et Procds (MEGeP)  

E-Print Network (OSTI)

-1200 Texasgulf Gypsum (Phosphogypsum) 50 1500-1800 ISG Resources, Inc. Peanut Maker (semi-granular) 71 1100

Mailhes, Corinne

219

6 Agronomic Recommendations and Procedures 2007 Peanut Production Guide  

E-Print Network (OSTI)

-1200 Texasgulf Gypsum (Phosphogypsum) 50 --- 1500-1800 ISG Resources, Inc. Peanut Maker (Semi-Granular) 71

Liskiewicz, Maciej

220

Agronomic Recommendations and Procedures 2007 Peanut Production Guide  

E-Print Network (OSTI)

-1200 Texasgulf Gypsum (Phosphogypsum) 50 --- 1500-1800 ISG Resources, Inc. Peanut Maker (Semi-Granular) 71

Liskiewicz, Maciej

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


221

Contributors: Maria Balota, Crop Physiologist  

E-Print Network (OSTI)

-1200 Texasgulf Gypsum (Phosphogypsum) 50 1500-1800 ISG Resources, Inc. Peanut Maker (semi-granular) 71 1100

Liskiewicz, Maciej

222

Publications from Research Conducted at FIE-TAX | ORNL Neutron...  

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

Thaler A., Ni N., Canfield P. C., McQueeney R. J., Schmalian J., Goldman A. I., "Unconventional pairing in the iron arsenide superconductors", Physical Review B 81, 140501...

223

Energy Basics: Single-Crystalline Thin Film Used in Photovoltaics  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

is not rare, but it is poisonous. Gallium arsenide has been developed for use in solar cells at about the same time that it has been developed for light-emitting diodes,...

224

Test vehicle detector characterization system for the Boeing YAL-1 airborne laser  

E-Print Network (OSTI)

The test vehicle detector characterization system provides a convenient and efficient tool for rapidly evaluating the optical sensitivity of the GAP6012, GAP100, GAP300, and GAP1000 indium gallium arsenide detectors used ...

Steininger-Holmes, Jason Thomas

2008-01-01T23:59:59.000Z

225

NREL preprints for the 23rd IEEE Photovoltaic Specialists Conference  

DOE Green Energy (OSTI)

Topics covered include various aspects of solar cell fabrication and performance. Aluminium-gallium arsenides, cadmium telluride, amorphous silicon, and copper-indium-gallium selenides are all characterized in their applicability in solar cells.

Fitzgerald, M. [ed.

1993-05-01T23:59:59.000Z

226

A near-infrared photoluminescence study of GaAs nanocrystals in SiO2 films formed by sequential ion implantation  

E-Print Network (OSTI)

and these unusual behaviors open new applications including large-gain, low-threshold quan- tum lasers, light-emitting diodes, single-electron transistors, and so on. A number of different techniques have been de- veloped

Heaton, Thomas H.

227

AlGaAsSb buffer/barrier on GaAs substrate for InAs channel devices with high electron mobility and practical reliability  

Science Conference Proceedings (OSTI)

Keywords: AlGaAsSb, Hall elements, InAs, Sb, buffer/barriers, deep quantum well, field effect transistors, reliability

S. Miya; S. Muramatsu; N. Kuze; K. Nagase; T. Iwabuchi; A. Ichii; M. Ozaki; I. Shibasaki

1996-03-01T23:59:59.000Z

228

Process for reducing radioactive contamination in phosphogypsum  

Science Conference Proceedings (OSTI)

A process of two crystallization stages for reducing radioactive contamination of phosphogypsum is disclosed. In the process anhydrite crystals are obtained through dehydration of the radiation containing phosphogypsum in strong sulfuric acid; a portion of the anhydrite crystals containing the radioactive contamination is converted to substantially radiation free gypsum by crystallizing out on a large solids concentration of radiation free gypsum seed crystals; and coarse radiation free gypsum crystals are separated from small anhydrite crystal relics containing substantially all of the radioactive contamination.

Gaynor, J.C.; Palmer, J.W.

1983-06-14T23:59:59.000Z

229

Hyperspectral Mineral Mapping For Geothermal Exploration On The...  

Open Energy Info (EERE)

possible presence of geothermal activity. So far, remotely-sensed gypsum anomalies have led to the identification of at least two previously unknown groups of warm and hot...

230

A Mineralogical Petrographic And Geochemical Study Of Samples...  

Open Energy Info (EERE)

montmorillonite, alunite, anhydrite, gypsum, calcite, and opaque minerals. The chemical composition of the minerals (104 analyses) was determined with Electron Probe...

231

The Effect of Circulating Coal Slurry Water Hardness on Coal ...  

Science Conference Proceedings (OSTI)

In order to investigate the effect of gypsum on flotation and coal slurry settling during coal slurry recirculation, the water hardness and proton conductivity of coal ...

232

Building and Fire Publications  

Science Conference Proceedings (OSTI)

... deRis, JL; Fire-Resistance and Sound-Insulation Ratings for Walls, Partitions, and Floors. ... Testing of Gypsum/Steel-Stud Wall Assemblies. ...

233

Building and Fire Publications  

Science Conference Proceedings (OSTI)

... loadbearing Gypsum/Steel-Stud Wall Assemblies. ... Spread Over Polyurethane Foam-Covered Walls. ... Low-Density Fibrous-Glass Thermal Insulation. ...

234

Microsoft Word - 42080DraftFinalReport060608.doc  

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

which were to include 1) a base-case test, then variations representing differing power plant: 2) emissions control configurations, 3) treatment of fine gypsum particles, 4)...

235

GESSO AGRÍCOLA E ADUBAÇÃO NITROGENADA NA CULTURA DO MILHO EM SISTEMA PLANTIO DIRETO.  

E-Print Network (OSTI)

??A considerably part of the high nitrogen (N) rates applied in corn is not absorbed due root growth restriction by subsoil acidity. Gypsum is able… (more)

RENATO ZARDO FILHO

2012-01-01T23:59:59.000Z

236

Experimental and analytical investigation of the seismic performance of low-rise masonry veneer buildings  

E-Print Network (OSTI)

Linderman, R.R. , “Narrow plywood shear panels”, Earthquakeracking behavior of plywood, OSB, gypsum, and fiberbondof sheathing type, i.e. , plywood versus wafer board, on the

Okail, Hussein

2010-01-01T23:59:59.000Z

237

EFFECT OF TEMPERATURE AND HUMIDITY ON FORMALDEHYDE EMISSIONS IN TEMPORARY HOUSING UNITS  

E-Print Network (OSTI)

constructed with ?-inch plywood with a vinyl or PVC skin ortile, gypsum board, shiplap, plywood, terracotta brick) thatsamples are all made from plywood. Humidity Equilibration

Parthasarathy, Srinandini

2010-01-01T23:59:59.000Z

238

Fire Protection of Structural Steel in High-Rise Buildings  

Science Conference Proceedings (OSTI)

... for Structural Fire Safety Design and Retrofit of Structures ... products or gypsum with a light weight aggregate ... in both cost and time savings in design ...

2005-04-29T23:59:59.000Z

239

Paper RILEM 3041 final  

Science Conference Proceedings (OSTI)

... Each of these compounds may react with the ingressing sulfates (represented in the form of gypsum) according to stoichiometric amounts defined ...

2004-07-14T23:59:59.000Z

240

Hydrogeochemical genesis of groundwaters with abnormal fluoride ...  

Science Conference Proceedings (OSTI)

fluoride concentrations from Zhongxiang City, Hubei Province, central China. Qinghai ..... gypsum source calcium can be calculated by subtracting the amount of ...

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Glossary of Terms - Sandia National Laboratories  

A management representation letter is required by General Accepted Auditing Standards (GAAS) and General Accepted Government Auditing Standards (GAGAS).

242

Collaborative Technologies for Distributed Science - Fusion Energy and High-Energy Physics (A25539)  

E-Print Network (OSTI)

General Atomics Report GA-A25539 (2006)24th Symposium on Fusion Technology Warsaw, pl, 2006999613320

Schissel, D.P.

2006-08-24T23:59:59.000Z

243

Buildings Energy Data Book: 1.6 Embodied Energy of Building Assemblies  

Buildings Energy Data Book (EERE)

6 6 Embodied Energy of Commercial Interior Wall Assemblies in the U.S. Embodied Energy CO2 Equivalent Interior Wall Type (2) (MMBtu/SF) (1) Emissions (lbs/SF) 2x4 wood stud (16" OC) + gypsum board (3) 0.03 2.84 2x4 wood stud (24" OC) + gypsum board (3) 0.03 2.78 2x4 wood stud (24" OC) + 2 gypsum boards (4) 0.04 4.45 Steel stud (16" OC) + gypsum board (4) 0.04 3.99 Steel stud (24" OC) + gypsum board (4) 0.04 3.64 Steel stud (24" OC) + 2 gypsum boards 0.05 5.31 6" Concrete block + gypsum board 0.21 34.02 6" Concrete block 0.19 32.34 Clay brick (4") unpainted 0.05 6.97 Note(s): Source(s): Assumptions: Values are general estimations for the U.S. 60 year building lifetime. Low rise building. 1) Embodied Energy: Energy use includes extraction, processing, transportation, construction, and disposal of each material. 2) All interior walls include two coats of latex paint

244

Clean process to destroy arsenic-containing organic compounds with recovery of arsenic  

DOE Patents (OSTI)

A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic. 1 fig.

Upadhye, R.S.; Wang, F.T.

1996-08-13T23:59:59.000Z

245

Evidence for three-dimensional Fermi-surface topology of the layered electron-doped iron superconductor Ba(Fe1 xCox)2As2  

SciTech Connect

The electronic structure of electron doped iron-arsenide superconductors Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} has been measured with Angle Resolved Photoemission Spectroscopy. The data reveal a marked photon energy dependence of points in momentum space where the bands cross the Fermi energy, a distinctive and direct signature of three-dimensionality in the Fermi surface topology. By providing a unique example of high temperature superconductivity hosted in layered compounds with three-dimensional electronic structure, these findings suggest that the iron-arsenides are unique materials, quite different from the cuprates high temperature superconductors.

Vilmercati, P. [University of Tennessee, Knoxville (UTK); Fedorov, A. V. [Lawrence Berkeley National Laboratory (LBNL); Vobornik, I. [TASC National Laboratory, Trieste, Italy; Manju, U. [TASC National Laboratory, Trieste, Italy; Panaccione, G. [TASC National Laboratory, Trieste, Italy; Goldoni, A. [Sincrotrone Trieste, Basovizza, Italy; Safa-Sefat, Athena [ORNL; McGuire, Michael A [ORNL; Sales, Brian C [ORNL; Jin, Rongying [ORNL; Mandrus, David [ORNL; Singh, David J [ORNL; Mannella, Norman [ORNL

2009-01-01T23:59:59.000Z

246

Luminescence properties of light-emitting diodes based on GaAs with the up-conversion Y{sub 2}O{sub 2}S:Er,Yb luminophor  

SciTech Connect

Y{sub 2}O{sub 2}S luminophors doped with Er{sup 3+} and Yb{sup 3+} ions are produced by means of solid-phase synthesis and deposited onto standard AL123A infrared light-emitting diodes. When excited with 940 nm radiation from a light-emitting diode, the structures exhibit intense visible up-conversion luminescence. A maximal brightness of 2340 cd/m{sup 2} of green and red up-conversion luminescence at corresponding wavelengths around 550 and 600 nm is observed for the Y{sub 2}O{sub 2}S compound doped with 2 at % Er{sup 3+} ions and 6 at % Yb{sup 3+} ions. The ratio of the intensity of green (or red) up-conversion luminescence to the intensity of infrared Stokes luminescence increases with increasing applied voltage. The efficiency of visible emission of the light-emitting diode structures is {eta} = 1.2 lm/W at an applied voltage of 1.5 V.

Gruzintsev, A. N., E-mail: gran@ipmt-hpm.ac.ru [Russian Academy of Sciences, Institute of Problems of Microelectronics Technology (Russian Federation); Barthou, C.; Benalloul, P. [Institute des NanoSciences (France)

2008-03-15T23:59:59.000Z

247

Incorporation of aqueous reaction kinetics and biodegradation into TOUGHREACT: Application of a multi-region model to hydrobiogeoChemical transport of denitrification and sulfate reduction  

E-Print Network (OSTI)

chemical and microbial species is solved on a component-by-component basis. The system of mixed equilibrium-kinetickinetic rate of dissolution and precipitation of minerals. Mineral Gypsum Goethite Pyrite Calcite Chemical

Xu, Tianfu

2008-01-01T23:59:59.000Z

248

Mapping evaporate minerals by ASTER  

Science Conference Proceedings (OSTI)

Evaporate minerals are important industrial raw materials that have been used in diverse industries for many years. As one of the most extensively used evaporate minerals, gypsum is an important raw material in the construction, agriculture, textile, ...

N. Serkan Oztan; M. Lutfi Suzen

2011-03-01T23:59:59.000Z

249

The utilization of flue gas desulfurization waste by-products in construction brick  

E-Print Network (OSTI)

Millions of tons of waste by-products from Texas coal burning plants are produced each year. Two common byproducts are the fuel ashes and calcium sulfate (gypsum). Fuel ashes result from the burning of coal. Gypsum is a byproduct of the air purification system, called Flue Gas Desulfurization (FGD). Abatement of these waste products is a growing concern, not only for the industry, but the environment as well. It is possible to produce a gypsum brick unit that can meet the engineering properties required by the Americans Society of Testing Materials (ASTM) standards by using these by-products. This can be accomplished at a cost less than the least expensive common fired clay brick that is used in construction operations. The gypsum brick can be manufactured using established methods that are currently in operation.

Berryman, Charles Wayne

1992-01-01T23:59:59.000Z

250

Effects of tunneling on groundwater flow and swelling of clay-sulfate rocks  

E-Print Network (OSTI)

[1] Swelling of clay-sulfate rocks is a major threat in tunneling. It is triggered by the transformation of the sulfate mineral anhydrite into gypsum as a result of water inflow in anhydrite-containing layers after tunnel ...

Butscher, Christoph

251

Arsenic speciation in pyrite and secondary weathering phases, Mother Lode gold district, Tuolumne County, California  

E-Print Network (OSTI)

minerals; goe, goethite; jar, jarosite; gyp, gypsum; hem,zone e DP-038 X DP-057 X goe, gyp goe, gyp goe goe jar,gyp jar, gyp jar jar, gyp jar, gyp jar jar jar, cal jar, gyp

Savage, K.S.; Tingle, Tracy N.; O'Day, Peggy A.; Waychunas, Glenn A.; Bird, Dennis K.

2004-01-01T23:59:59.000Z

252

Infiltration heat recovery in building walls: Computational fluid dynamics investigations results  

E-Print Network (OSTI)

e.g. , gypsum wallboard or plywood) with space between theproperties are those of plywood: density is 544 kg/m 3 ,a layer of sheathing (plywood) on each side of vertical

Abadie, Marc O.; Finlayson, Elizabeth U.; Gadgil, Ashok J.

2002-01-01T23:59:59.000Z

253

IN-SITU MEASUREMENT OF WALL THERMAL PERFORMANCE: DATA INTERPRETATION AND APPARATUS DESIGN RECOMMENDATIONS  

E-Print Network (OSTI)

6 ft) wall section, made from plywood, extruded polystyrene,to the receiving the plywood laboratory test, sheathing wasto the massive layers of plywood and gypsum board on the two

Modera, M.P.; Sherman, M.H.; de Vinuesa, S.G.

2008-01-01T23:59:59.000Z

254

Techniques for reducing exposures to volatile organic compounds associated with new construction and renovation  

E-Print Network (OSTI)

applied to gypsum board and plywood substrates. This wasapplied to 1.1-m 2 of plywood. The carpet and vinyl flooringThe SGLPs were applied to plywood. The two non-VOC paints,

Hodgson, A.T.; Shimer, D.A.

1999-01-01T23:59:59.000Z

255

Cool roofs as an energy conservation measure for federal buildings  

E-Print Network (OSTI)

of ¼” asphalt shingle, ½” plywood, with an attic cavity andbuilt-up roofs with ½ inch plywood, attic space, and an R-11a combination of stucco, plywood, insulation and gypsum, or

Taha, Haider; Akbari, Hashem

2003-01-01T23:59:59.000Z

256

Table 2.2 Nonfuel (Feedstock) Use of Combustible Energy, 2010...  

U.S. Energy Information Administration (EIA) Indexed Site

* * * * 0 0 1 327410 Lime * 0 0 0 0 0 0 * 327420 Gypsum * 0 * 0 0 0 0 * 327993 Mineral Wool * 0 * 0 * 0 0 * 331 Primary Metals 420 * * 28 * 334 23 34 331111 Iron and Steel Mills...

257

" Row: NAICS Codes; Column: Energy Sources...  

U.S. Energy Information Administration (EIA) Indexed Site

1,"*","*",5,"*",4,"*",23 327420," Gypsum",85,1845,"*","*",74,"*",0,0,2 327993," Mineral Wool",50,3978,0,"*",33,"*",0,"*","*" 331,"Primary Metals",1910,133236,3,1,610,1,17,9,133...

258

PureAir.p65  

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

or more with 2.0-4.5 percent sulfur coals. The design range for calcium to sulfur stoichiometric ratio (SR) was 1.01-1.07 with the upper value set by gypsum purity requirements...

259

Preliminary materials assessment for the Satellite Power System (SPS)  

DOE Green Energy (OSTI)

Presently, there are two SPS reference design concepts (one using silicon solar cells; the other using gallium arsenide solar cells). A materials assessment of both systems was performed based on the materials lists set forth in the DOE/NASA SPS Reference System Report: Concept Development and Evaluation Program. This listing identified 22 materials (plus miscellaneous and organics) used in the SPS. Tracing the production processes for these 22 materials, a total demand for over 20 different bulk materials (copper, silicon, sulfuric acid, etc.) and nealy 30 raw materials (copper ore, sand, sulfur ore, etc.) was revealed. Assessment of these SPS material requirements produced a number of potential material supply problems. The more serious problems are those associated with the solar cell materials (gallium, gallium arsenide, sapphire, and solar grade silicon), and the graphite fiber required for the satellite structure and space construction facilities. In general, the gallium arsenide SPS option exhibits more serious problems than the silicon option, possibly because gallium arsenide technology is not as well developed as that for silicon. Results are presented and discussed in detail. (WHK)

Teeter, R.R.; Jamieson, W.M.

1980-01-01T23:59:59.000Z

260

I'm happy to report that The Earth Observer is beginning its 20th year as a NASA publication. The first issue  

E-Print Network (OSTI)

arsenide GHG greenhouse gas GHP geothermal heat pump GSA General Services Administration GSHP ground source heat pump GS-IHP ground source integrated heat pump GUI graphical user interface GW gigawatt GWh Reliability and Security TES thermal energy storage TM3PS Tactical Modular Mobile Microgrid Power Systems TPD

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

An Ultra High Speed Test System  

Science Conference Proceedings (OSTI)

The test-head subsystem presented uses gallium arsenide pin electronics to provide nonrepeating zero data rates up to 1.2 Gb/s. The device under test is connected to laser-scanned optical sensors, and the test system receivers use an electrooptic measurement ...

Francois Henley

1989-01-01T23:59:59.000Z

262

SOLERAS - University Research Project. Progress report No. 3, 1984-85 annual report  

Science Conference Proceedings (OSTI)

The accomplishments of solar energy research projects maintained by nine US universities are summarized. Some research topics covered include: photosynthesis; passive cooling; crystal growth of gallium arsenides; concentrating optics for PV conversion; amorphous silicon alloys; solar insolation; solar ponds; and wind power. (BCS)

Not Available

1985-09-01T23:59:59.000Z

263

SOLERAS - University Research Project. Progress report 1, December 1984  

Science Conference Proceedings (OSTI)

Progress to date on each of the research efforts in direct solar energy applications at public and private institutions of higher education and research in the United States is addressed. Some research topics covered include: concentrating optics for PV conversion; wind power; solar ponds; photosynthesis; amorphous silicon alloys; passive cooling; crystal growth of gallium arsenides; and solar insolation.

Not Available

1984-12-01T23:59:59.000Z

264

Investigation of a mercury speciation technique for flue gas desulfurization materials  

Science Conference Proceedings (OSTI)

Most of the synthetic gypsum generated from wet flue gas desulfurization (FGD) scrubbers is currently being used for wallboard production. Because oxidized mercury is readily captured by the wet FGD scrubber, and coal-fired power plants equipped with wet scrubbers desire to benefit from the partial mercury control that these systems provide, some mercury is likely to be bound in with the FGD gypsum and wallboard. In this study, the feasibility of identifying mercury species in the FGD gypsum and wallboard samples was investigated using a large sample size thermal desorption method and samples from power plants in Pennsylvania. Potential candidates of pure mercury standards including mercuric chloride, mercurous chloride, mercury oxide, mercury sulfide, and mercuric sulfate were analyzed to compare their results with those obtained from FGD gypsum and dry wallboard samples. Although any of the thermal evolutionary curves obtained from these pure mercury standards did not exactly match with those of the FGD gypsum and wallboard samples, it was identified that Hg{sub 2}Cl{sub 2} and HgCl{sub 2} could be candidates. An additional chlorine analysis from the gypsum and wallboard samples indicated that the chlorine concentrations were approximately 2 orders of magnitude higher than the mercury concentrations, suggesting possible chlorine association with mercury. 21 refs., 5 figs., 3 tabs.

Lee, J.Y.; Cho K.; Cheng L.; Keener, T.C.; Jegadeesan G.; Al-Abed, S.R. [University of Cincinnati, Cincinnati, OH (United States). Department of Chemical and Materials Engineering

2009-08-15T23:59:59.000Z

265

Temperature Measurements in Full-Scale Wood Stud Shear Walls  

E-Print Network (OSTI)

This report presents the results of 10 full-scale fire resistance tests conducted at the National Fire Laboratory on load-bearing gypsum board protected, wood stud shear wall assemblies with and without resilient channels on the fire-exposed side. The two assembly arrangements studied were: symmetrical installation 1x1 (one layer of gypsum board on each of the exposed and unexposed sides) and asymmetrical installation of the shear membrane (one layer of gypsum board on both the exposed and unexposed sides and a shear wall membrane as a base layer alternating between the exposed (2x1) and unexposed sides (1x2)) on a wood stud frame. The gypsum board was 12.7 mm thick Type X. The insulations used were glass and rock fibres. The shear membranes used were plywood and oriented strand board (OSB). Tests were conducted to determine the effects of the placement of the shear membrane on the exposed/unexposed face, type of shear membrane, insulation type, load intensity and resilient channel installations on the fire resistance of gypsum board protected, wood stud shear wall assemblies. Details of the results, including the temperatures and deflections measured during the fire tests, are presented. ACKNOWLEDGEMENTS This research is part of a consortium project on the fire resistance and sound performance of wall assemblies - Phase II, among the following partners: . Canadian Wood Council . Canadian Home Builders Association . Canadian Sheet Steel Building Institute . Gypsum Manufacturers of Canada . Owens-Corning Canada . Roxul Inc.

V. K. R. Sultan; M. A. Denham; V. K. R. Kodur; M. A. Sultan; E. M. A. Denham; Canadian Wood Council; Shear Walls; Shear Walls; Shear Walls; Shear Walls

1996-01-01T23:59:59.000Z

266

Impact of elliptical cross-section on the propagation delay of multi-channel gate-all-around MOSFET based inverters  

Science Conference Proceedings (OSTI)

Multi-channel (MC) gate-all-around (GAA) metal-oxide-semiconductor field-effect transistor (MOSFET) is one of the promising candidates for the next-generation high performance devices. However, due to fabrication imperfections the cross-section of GAA ... Keywords: Effective diameter, Gate-all-around (GAA), Metal-oxide-semiconductor field-effect transistor (MOSFET), Multi-channel, Propagation delay, Scaling

Subindu Kumar, Shankaranand Jha

2013-09-01T23:59:59.000Z

267

Profiling the Built-In Electrical Potential in III-V Multijunction Solar Cells (Poster)  

DOE Green Energy (OSTI)

We have observed three electrical potentials at the top, tunneling, and bottom junctions of GnInP{sub 2}/GaAs tandem-junction solar cells, by performing the UHV-SKPM measurement. The effect of laser illumination was avoided by using GaAs laser with photon energy of 1.4 eV for the AFM operation. We also observed higher potentials at the atomic steps than on the terraces for both p-type GaInP{sub 2} epitaxial layer and p-type GaAs substrate, and found that the potential at steps of GaAs substrate depends on the step directions.

Jiang, C.-S.; Friedman, D. J.; Moutinho, H. R.; Al-Jassim, M. M.

2006-05-01T23:59:59.000Z

268

NIST Terahertz Reflection Measurements  

Science Conference Proceedings (OSTI)

... b) Superimposed Fourier Transform amplitude and power reflection map ... laser for broadband (0.2-2.5) THz GaAs antenna generation and detection ...

2013-04-01T23:59:59.000Z

269

Optical Tech Div 1999 - Technical Highlights - Figure 6  

Science Conference Proceedings (OSTI)

... of wavelength are shown for six materials: germanium (Ge), silicon (Si), gallium arside (GaAs), magnesium oxide (MgO), lithium fluoride (LiF), and ...

270

Optical Technology Division 1999 - Technical Highlights ...  

Science Conference Proceedings (OSTI)

... of wavelength are shown for six materials: germanium (Ge), silicon (Si), gallium arside (GaAs), magnesium oxide (MgO), lithium fluoride (LiF), and ...

271

NIST Steven Brown  

Science Conference Proceedings (OSTI)

... Award for "Electron and nuclear spin interactions ... single GaAs quantum dots," Physical Review Letters ... Ph.D. Applied Physics, University of Michigan ...

2011-10-11T23:59:59.000Z

272

JEM Abstracts: May 1997  

Science Conference Proceedings (OSTI)

They enable conversion of electrical energy to mechanical energy, they underlie ... Direct Etching of GaAs Using Chlorofluorocarbon (CFC) Alternative Gases

273

Poster Session - Programmaster.org  

Science Conference Proceedings (OSTI)

Feb 14, 2010... such as electrical short circuit or debris for equipment manufacturers and .... Reliability test vehicles comprise a GaAs chip which was flip chip ...

274

Technical Program, Thursday Morning Sessions  

Science Conference Proceedings (OSTI)

Step-Free InAs Quantum Well Selectively Grown on GaAs (111)B Substrate: ... Jonas Johansson, Lars Samuelson and Werner Seifert, Solid State Physics, Lund  ...

275

Accelerating Scientific Discovery Through Computation and ...  

Science Conference Proceedings (OSTI)

... electronic structure of GaAs nanocrystals, inclu- sion of ... lowest hole state in a CdS nano- crystal. ... well region of a nanoheterostructured nanocrystal. ...

2009-09-08T23:59:59.000Z

276

Solar Photovoltaics Research and Technology: The Revolution ...  

Science Conference Proceedings (OSTI)

Moreover, technology progress and ownership for next-generation solar PV mandates a ... Dislocations in Si-Doped LEC GaAs Revisited: A Spectrum Image

277

Project Summaries  

Science Conference Proceedings (OSTI)

... this will increase productive utilization of the Raritan cluster to close to 100%. ... on a substrate of GaAs results in formation of mounds, rather than ...

2006-02-06T23:59:59.000Z

278

JEM Abstracts: January 1995  

Science Conference Proceedings (OSTI)

... arsenic stabilized growth of GaAs resulted in low mobility, p-type material. ... Electron Irradiation Induced Defects and Schottky Diode Characteristics for ...

279

JEM Abstracts: April 1995  

Science Conference Proceedings (OSTI)

Selected area electron diffraction (SAD) patterns at the interface confirmed that ..... Mobility of Modulation Doped AlGaAs/Low-Temperature MBE-Grown GaAs ...

280

Ultrafast shift and injection currents observed in wurtzite semiconductors via emitted terahertz radiation  

E-Print Network (OSTI)

and injection currents have been generated in bulk GaAs and strained GaAs quantum wells QWs , respectivelyUltrafast shift and injection currents observed in wurtzite semiconductors via emitted terahertz; published online 18 November 2005 Shift and injection currents are generated in the wurtzite semiconductors

Van Driel, Henry M.

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

The MOCVD Growth Technique  

Science Conference Proceedings (OSTI)

...can be expressed as: (C 2 H 5 ) 3 Ga + AsH 3 â?? GaAs + 3C 2 H 6 (Eq 23) (CH 3 ) 3 Ga + AsH 3 â?? GaAs + 3CH 4 (Eq 24) The

282

The effects of quantum dot coverage in InAs/(In)GaAs nanostructures for long wavelength emission  

Science Conference Proceedings (OSTI)

We present a study on the effects of quantum dot coverage on the properties of InAs dots embedded in GaAs and in metamorphic In0.15Ga0.85As confining layers grown by molecular beam epitaxy on GaAs substrates. We show that redshifted ... Keywords: Long wavelength emission, Molecular beam epitaxy, Quantum dot ripening, Quantum dots

G. Trevisi; L. Seravalli; P. Frigeri; M. Prezioso; J. C. Rimada; E. Gombia; R. Mosca; L. Nasi; C. Bocchi; S. Franchi

2009-03-01T23:59:59.000Z

283

Defect gap states on III-V semiconductor-oxide interfaces (invited)  

Science Conference Proceedings (OSTI)

Interfaces models of (100)GaAs and various high K oxides such as HfO"2, Gd"2O"3 or Al"2O"3 are used to study the interfacial defects and mis-bonded sites which can introduce states into the semiconductor gap, and cause the Fermi level pinning observed ... Keywords: Calculation, FET, GaAs, Interface states, Oxide, Passivation

J. Robertson; L. Lin

2011-07-01T23:59:59.000Z

284

Comparison of quantum confinement effects between quantum wires and dots  

E-Print Network (OSTI)

? wire . Si GaAs InAs InP CdSe CdS CdTe ? dot ? dot ? wire ?systems like InP and CdSe. Here, we like to address thesematerials: Si, InP, InAs, GaAs, CdSe, CdS, and CdTe. Unlike

Li, Jingbo; Wang, Lin-Wang

2004-01-01T23:59:59.000Z

285

Design of a wideband multi-standard antenna switch for wireless communication devices  

Science Conference Proceedings (OSTI)

A wideband Low Power Single Pole 6-Throw (SP6T) antenna switch has been designed for GSM/DCS/802.11b mobile standards using a newly improved architecture and fabricated using a pseudomorphic depletion mode 0.18@mm HEMT GaAs process. The switch exhibits ... Keywords: Antenna switch, GaAs, MMIC, Mobile telecommunications, Wideband, pHEMT transistors

Vlad Marian; Jacques Verdier; Bruno Allard; Christian Vollaire

2011-05-01T23:59:59.000Z

286

Monolithic high voltage nonlinear transmission line fabrication process  

DOE Patents (OSTI)

A process for fabricating sequential inductors and varistor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varistor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process. 6 figs.

Cooper, G.A.

1994-10-04T23:59:59.000Z

287

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology. Annual subcontract report, 1 August 1991--31 July 1992  

DOE Green Energy (OSTI)

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, {approximately} 1 {times} 10{sup 5} cm{sup {minus}5}, as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 {times}10{sup 7} cm{sup {minus}2}. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. [Spire Corp., Bedford, MA (United States)

1993-04-01T23:59:59.000Z

288

Monolithic high voltage nonlinear transmission line fabrication process  

DOE Patents (OSTI)

A process for fabricating sequential inductors and varactor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varactor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process.

Cooper, Gregory A. (346 Primrose Dr., Pleasant Hill, CA 94523)

1994-01-01T23:59:59.000Z

289

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology  

DOE Green Energy (OSTI)

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, [approximately] 1 [times] 10[sup 5] cm[sup [minus]5], as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 [times]10[sup 7] cm[sup [minus]2]. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. (Spire Corp., Bedford, MA (United States))

1993-04-01T23:59:59.000Z

290

Profile NeutronDetector 9-16-04..pmd  

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

GALLIUM ARSENIDE SEMICONDUCTOR-BASED GALLIUM ARSENIDE SEMICONDUCTOR-BASED NEUTRON DETECTOR B E N E F I T S Portable, Accurate Device Detects and Monitors Neutrons and Nuclear Materials * More accurate and sensitive than other technologies * Performance won't degrade over time * Easy implementation and deployment * Rugged, lightweight, and portable for field use * Reduces false readings * Requires less power * Low mass-production cost (about $1 per chip) * Neutron detection * Detecting and monitoring nuclear materials and weapons * Permanent installations and portable field operation * High-vacuum environments (e.g., physics labs and space platforms) An advanced neutron detector developed by Argonne National Laboratory and Kansas State University accurately detects neutrons and finds concealed nuclear weapons and materials, even in harsh or challenging environments. The key

291

Development of electrochemical photovoltaic cells. Third technical progress report, November 1, 1979-January 31, 1980  

DOE Green Energy (OSTI)

The development of stable, efficient, electrochemical photovoltaic cells based on silicon and gallium arsenide in non-aqueous electrolyte systems is being investigated. The effect of surface condition of silicon electrodes on electrochemical and physical characteristics has been studied. An electrode-supporting electrolyte interaction in acetonitrile has been identified which leads to etching of the surface. Improved performance can result, which has practical significance. Gallium arsenide electrodes have been electrochemically characterized in cells containing propylene carbonate with a ferrocene/ferricenium redox additive. Degradation of the ferricenium salt under illumination has been investigated. Other redox couples studied to date have not given promising results. Long-term stability experiments have been deferred while a better understanding of electrode behavior is being obtained.

Byker, H.J.; Schwerzel, R.E.; Wood, V.E.; Austin, A.E.; Brooman, E.W.

1980-03-07T23:59:59.000Z

292

Buildings Energy Data Book: 9.4 High Performance Buildings  

Buildings Energy Data Book (EERE)

4 4 Case Study, The Philip Merrill Environmental Center, Annapolis, Maryland (Office) Building Design Floor Area: 31,000 SF Floors: 2 Footprint: 220 ft. x (1) 2 Floors of open office space Attached pavilion containing: Meeting space Kitchen Staff dining Conference room Shell Windows U-Factor SHGC (2) Type: Double Pane, Low-e, Argon Filled Insulating Glass 0.244 0.41 Wall/Roof Material Effective R-Value Interior Wall plywood, gypsum, SIP foam, and sheathing 28.0 Exterior Wall gypsum and insulated metal framing 9.3 Roof plywood, gypsum, SIP foam, and sheathing 38.0 HVAC 18 ground source heat pumps fin and tube radiators connected to a propane boiler 1 air condtioning unit Lighting Power Densities (W/SF) First Floor: 1.2 Second Floor: 1.6 Conference Room: 1.4 Energy/Power PV System: 4.2 kW thin-film system

293

World Supply and Demand  

Science Conference Proceedings (OSTI)

Table 4   Gallium arsenide ingot, wafer, and device manufacturers...X Sweden Semitronics AB X United Kingdom General Electricity Company (U.K.) X X X X X MCP Electronic Materials Ltd. X United States Airtron Division of Litton Industries X Anadigics Inc. X X X Applied Solar Energy Corporation X X AT & T Bell Laboratories X X X X Bertram Laboratories X Crystal Specialties,...

294

Sulfide-Driven Arsenic Mobilization from Arsenopyrite and Black Shale Pyrite  

Science Conference Proceedings (OSTI)

We examined the hypothesis that sulfide drives arsenic mobilization from pyritic black shale by a sulfide-arsenide exchange and oxidation reaction in which sulfide replaces arsenic in arsenopyrite forming pyrite, and arsenide (As-1) is concurrently oxidized to soluble arsenite (As+3). This hypothesis was tested in a series of sulfide-arsenide exchange experiments with arsenopyrite (FeAsS), homogenized black shale from the Newark Basin (Lockatong formation), and pyrite isolated from Newark Basin black shale incubated under oxic (21% O2), hypoxic (2% O2, 98% N2), and anoxic (5% H2, 95% N2) conditions. The oxidation state of arsenic in Newark Basin black shale pyrite was determined using X-ray absorption-near edge structure spectroscopy (XANES). Incubation results show that sulfide (1 mM initial concentration) increases arsenic mobilization to the dissolved phase from all three solids under oxic and hypoxic, but not anoxic conditions. Indeed under oxic and hypoxic conditions, the presence of sulfide resulted in the mobilization in 48 h of 13-16 times more arsenic from arsenopyrite and 6-11 times more arsenic from isolated black shale pyrite than in sulfide-free controls. XANES results show that arsenic in Newark Basin black shale pyrite has the same oxidation state as that in FeAsS (-1) and thus extend the sulfide-arsenide exchange mechanism of arsenic mobilization to sedimentary rock, black shale pyrite. Biologically active incubations of whole black shale and its resident microorganisms under sulfate reducing conditions resulted in sevenfold higher mobilization of soluble arsenic than sterile controls. Taken together, our results indicate that sulfide-driven arsenic mobilization would be most important under conditions of redox disequilibrium, such as when sulfate-reducing bacteria release sulfide into oxic groundwater, and that microbial sulfide production is expected to enhance arsenic mobilization in sedimentary rock aquifers with major pyrite-bearing, black shale formations.

Zhu, W.; Young, L; Yee, N; Serfes, M; Rhine, E; Reinfelder, J

2008-01-01T23:59:59.000Z

295

SOLERAS - University Research Project. Progress report 2  

Science Conference Proceedings (OSTI)

Progress to date on each of the research efforts in direct solar energy applications at public and private institutions of higher education and research in the United States is addressed. Some research topics covered include: concentrating optics for PV conversion; wind power; solar ponds; photosynthesis; amorphous silicon alloys; passive cooling; crystal growth of gallium arsenides; and solar insolation. The period of work covered by these reports is June 1984 through February 1985.

Not Available

1985-03-01T23:59:59.000Z

296

NEWTON, Ask a Scientist at Argonne National Labs  

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

Mica, Gypsum, and Hardness Mica, Gypsum, and Hardness Name: Melissa Status: educator Grade: 4 Location: NC Country: USA Date: Winter 2011-2012 Question: I have a question regarding the hardness of mica and gypsum. Gypsum is a 2 on Moh's hardness scale and mica is somewhere between a 2 and 3. However, mica breaks and scratches very easily by a penny, paper clip, and fingernail and gypsum does not. What is a good way to explain to my students how gypsum is still "softer" on the scale? Obviously, mica breaks apart very easily. Replies: Melissa, Mineral hardness and mineral cleavage are separate issues. Mineral hardness is a measure of a mineral's ability to resist being scratched. Mineral cleavage is the ability for a mineral to split along weakly-bonded atomic planes. The micas have one good mineral cleavage. That is, mica splits nicely in along one plane. Halite (table salt), on the other hand, splits equally well in three orthogonal directions (that is, along three planes, each of which is at 90 degrees to the others). Shake out some table salt on an overhead projector and have the students walk up to the screen. They will see that all salt has cubic mineral cleavage. I don't know how much snow you get in North Carolina, but if you get some salt that is used to melt ice you will note that it too has cubic cleavage. When you break up the large salt crystals you will observe that they break into smaller cubes. When you break the mica, it will break into smaller sheets.

297

Advanced Flue Gas Desulfurization (AFGD) demonstration project: Volume 2, Project performance and economics. Final technical report  

SciTech Connect

The project objective is to demonstrate removal of 90--95% or more of the SO{sub 2} at approximately one-half the cost of conventional scrubbing technology; and to demonstrate significant reduction of space requirements. In this project, Pure Air has built a single SO{sub 2} absorber for a 528-MWe power plant. The absorber performs three functions in a single vessel: prequencher, absorber, and oxidation of sludge to gypsum. Additionally, the absorber is of a co- current design, in which the flue gas and scrubbing slurry move in the same direction and at a relatively high velocity compared to conventional scrubbers. These features all combine to yield a state- of-the-art SO{sub 2} absorber that is more compact and less expensive than conventional scrubbers. The project incorporated a number of technical features including the injection of pulverized limestone directly into the absorber, a device called an air rotary sparger located within the base of the absorber, and a novel wastewater evaporation system. The air rotary sparger combines the functions of agitation and air distribution into one piece of equipment to facilitate the oxidation of calcium sulfite to gypsum. Additionally, wastewater treatment is being demonstrated to minimize water disposal problems inherent in many high-chloride coals. Bituminous coals primarily from the Indiana, Illinois coal basin containing 2--4.5% sulfur were tested during the demonstration. The Advanced Flue Gas Desulfurization (AFGD) process has demonstrated removal of 95% or more of the SO{sub 2} while providing a commercial gypsum by-product in lieu of solid waste. A portion of the commercial gypsum is being agglomerated into a product known as PowerChip{reg_sign} gypsum which exhibits improved physical properties, easier flowability and more user friendly handling characteristics to enhance its transportation and marketability to gypsum end-users.

NONE

1996-04-30T23:59:59.000Z

298

Characterization studies for the reuse of phosphogypsum as a raw material in the civil construction industry of Brazil  

SciTech Connect

NORM stands for 'naturally occurring radioactive material', which is a material that naturally contains one or more radionuclides, mainly, uranium, thorium and potassium-40, and their radioactive decay products, such as radium and radon. An example of this material is the Phosphogypsum (PG), which results from the processing of phosphate ore into phosphoric acid for fertilizer production. In order to support regulation of the reuse of phosphogypsum as a raw material of the Brazilian civil construction industry, a characterization study was performed. The physical and chemical properties of PG and natural gypsum were determinate by evaluating the results of thermal (DTA and TG), X-ray fluorescence (XRF), X-ray diffraction (XRD) and laser granulometric analyses. The radioactivity concentration of each sample was measured by gamma spectrometry analyses. The results of thermal analyses demonstrated that phosphogypsum must be treated (initially heated in an electrical oven at 60 deg. C for 24 hours, then sieved and heated again at 160 deg. C for one hour) to obtain the same mineralogical properties of the gypsum used in the civil construction industry. The X- ray fluorescence analysis showed that PG and natural gypsum are similar with both being composed mainly of S, O, Ca, P and small quantities of trace elements (Ce, Ti, La, Sr, Zr, and Pr). The main crystalline compounds found in PG samples were gypsita (CaSO{sub 4}.2H{sub 2}O) and in natural gypsum were bassanite (CaSO{sub 4}.0.5H{sub 2}O). The concentration of Ra-226, Ra-228 and Pb-210 present in PG samples was 467 Bq/kg, 224 Bq/kg and 395 Bq/kg, respectively. The levels of radioactivity in natural gypsum samples were much lower (around 3 Bq/kg). The same behavior was observed for the uranium and thorium content. The results of all the analyses showed that phosphogypsum can be a viable substitute for gypsum, after certain, beneficial processes. (authors)

Jacomino, V.M. [Development Center of Nuclear Technology, Belo Horizonte, MG (Brazil); Canut, M.; Magalhaes Gomes, A.; Yoshida, M.I. [Federal Univ. of Minas Geris, Belo Horizonte, MG (Brazil); Fields, D. [Roane State Community College, Mathematics and Sciences Div., Roane State Community College, Harriman, TN (United States)

2007-07-01T23:59:59.000Z

299

DEDALOS NREL: Cooperative Research and Development Final Report, CRADA Number CRD-07-237  

DOE Green Energy (OSTI)

Currently High Concentration Photovoltaic (HCPV) terrestrial modules are based on the combination of optic elements that concentrate the sunlight into much smaller GaAs space cells to produce electricity. GaAs cell technology has been well developed for space applications during the last two decades, but the use of GaAs cells under concentrated sunlight in terrestrial applications leaves unanswered questions about performance, durability and reliability. The work to be performed under this CRADA will set the basis for the design of high-performance, durable and reliable HCPV terrestrial modules that will bring down electricity production costs in the next five years.

Friedman, D.

2013-06-01T23:59:59.000Z

300

ELECTRON-VOLTAIC CELL STUDY  

SciTech Connect

The properties of Si, GaAs, Ge, and possible beta sources were considered, together with radiation damage to the three materials. Additionally, the characteristics of p-n junction cells under beta activity were derived, and the characteristics of GaAs and Si cells were obtained experimentally. The results indicate that a nuclear battery using GaAs or n-p Si cells with Pm/sup 147/ as the source would operate for 5 to 10 yr with very little radiation damage. Cell characteristics for a given source activity were calculated. 66 references. (D.C.W.)

Robison, W.C.; Nelson, M.D.

1963-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


301

Available Technologies: Low Resistance, p-Type Ohmic Contacts ...  

Novel Structured LED and OLED Devices, IB-2230. Co-implantation of Group VI Elements and Nitrogen for the Formation of Non-Alloyed Ohmic Contacts for n-type GaAs, IB ...

302

Lasing characteristics of GaSb/GaAs self-assembled quantum dots embedded in an InGaAs quantum well  

E-Print Network (OSTI)

be applicable to light sources in fiber-optic communication systems.13 However, there have been no reports intriguing optoelectronic device possibilities on GaAs substrates including lasers, detectors, or solar cells

Jalali. Bahram

303

GaAs/AlGaAs nanostructured composites for free-space and integrated optical devices  

E-Print Network (OSTI)

Fainman, "Influence of chlorine on etched sidewalls inFainman, “Influence of chlorine on etched sidewalls inthe RIBE of GaAs with chlorine (Cl 2 ), ion beam sputtering

Tsai, Chia-Ho

2006-01-01T23:59:59.000Z

304

M6, Enhancement of Hole Transport and Carrier Distribution in ...  

Science Conference Proceedings (OSTI)

DD1, Enhanced Spin Injection and Spin Lifetimes in Graphene ... FF5, GaInNAsSb Quantum Wells with Strain-Compensating GaAsP Layers for GaAs-

305

Rotor Scale Model Tests for Power Conversion Unit of GT-MHR (A26845)  

E-Print Network (OSTI)

Proc. Of 5th International Conf. On High Temperatore Reactor Technology, Prague, Czech Republic, 2010; General Atomics Report GA-A26845 (2010)5th International Conference on High Temperature Reactor Technology Prague, CZ, 2010999619072

Baxi, C.B.

2010-08-18T23:59:59.000Z

306

In-situ deposition of high-k dielectrics on III-V compound semiconductor in MOCVD system  

E-Print Network (OSTI)

In situ deposition of high-k materials to passivate the GaAs in metal organic chemical vapor deposition (MOCVD) system was well demonstrated. Both atomic layer deposition (ALD) and chemical vapor deposition (CVD) methods ...

Cheng, Cheng-Wei, Ph.D. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

307

Comprehensive Measurements and Modeling of SOL and Core Plasma Fueling and Carbon Sources in DIII-D (A25072)  

E-Print Network (OSTI)

Proc. 32nd Euro. Conf. On Plasma Phys., Tarragona, Spain, 2005; General Atomics Report GA-A25072 (2005)32nd EPS Conference on Controlled Fusion and Plasma Physics Tarragona, ES, 2005999610815

Groth, M.

2005-07-06T23:59:59.000Z

308

Nonlinear Dynamics and Energy Loss Mechanisms of ELMs (A25091)  

E-Print Network (OSTI)

Proc. 32nd Euro. Conf. On Plasma Phys., Tarragona, Spain, 2005; General Atomics Report GA-A25091 (2005)32nd EPS Conference on Controlled Fusion and Plasma Physics Tarragona, ES, 2005999610795

Snyder, P.B.

2005-06-27T23:59:59.000Z

309

Poster Presentations | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

(Smedley-Alkali) .pdf file (455KB) GaAs Detectors (Durbin) .pdf file (2.0MB) Detector R&D @ LBNL (Denes) .pdf file (2.5MB) Advanced Beam Physics @ UCLA (Musumeci) .pdf file...

310

Technical Session II Talks | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Technical Session II Talks Print Text Size: A A A RSS Feeds FeedbackShare Page Detector R&D at LBNL (Denes) .pdf file (6.2MB) GaAs Detector (Durbin) .pdf file (450KB) Advanced...

311

MSTC - Microsystems Science, Technology, and Components - RF...  

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

band RF input and supplies N identical outputs (N4 or 8). SiGe, GaAs, GaN RFICs. Passive RF detectors - Pyroelectric microdetectors that produce a DC output proportional to...

312

Thursday Morning Sessions (June 27)  

Science Conference Proceedings (OSTI)

"Interfacial Barrier of LTG-Al0.3Ga0.7As Epitaxial Passivation in GaAs FETs:" N.X. NGUYEN, J.P. Ibbetson, U.K. Mishra, Electrical and Computer Engineering ...

313

JEM Table of Contents: June 1994 - TMS  

Science Conference Proceedings (OSTI)

569-576] G. Sreenivas, S.S. Ang, and W.D. Brown. Molecular Beam Deposition of Low-Resistance Polycrystalline GaAs [pp. 577-580] K. Mochizuki T. Nakamura, ...

314

Cogenerating Photovoltaic and Thermal Solar Collector  

E-Print Network (OSTI)

heat US Department of Energy: Parabolic Trough SpectroLab Concentrating Terrestrial PV Cell C1MJ CDO peak load and irradiance hours of the day #12;Design · Parabolic solar collector · GaAs PV cells

Eirinaki, Magdalini

315

band density of states whereas the higher energy side is deter-mined by the thermal distribution. With increasing tem-  

E-Print Network (OSTI)

. wavelength, pm ~ Fig. 4 Demonstration ofthe application ofan InAs, -.Sb, light emitting diode as a CO, sensor light emitting diodes on GaAs or Si substrates. The devices readily result in a new generation of infra

Chen, Sheng

316

First principle thousand atom quantum dot calculations  

E-Print Network (OSTI)

and A. Zunger, Appl. Phys. Lett. system bulk_CdSe (100)_CdSe (lll).CdSe (110)_CdSe (110)_GaAs Ap AE (meV) g (llO)-Si

Wang, Lin-Wang; Li, Jingbo

2004-01-01T23:59:59.000Z

317

Diamond Gyrotron Windows on the DIII-D Tokamak (A25103)  

E-Print Network (OSTI)

Proc. 30th Infrared Millimeter Wave Conf., Williamsburg, Virginia, 2005; General Atomics Report GA-A25103 (2005)30th International Conference on Infrared and Millimeter Waves Williamsburg Virginia, US, 2005999610845

Gorelov, I.A.

2005-08-10T23:59:59.000Z

318

II4, Compositionally-Graded Layers Composed of Tandem InGaAs ...  

Science Conference Proceedings (OSTI)

The specification of the 6° miscut is important because it provides step ..... of Metamorphic InGaP on GaAs and GaP for Wide-Bandgap Photovoltaic Junctions.

319

Substrate engineering for monolithic integration of III-V semiconductors with Si CMOS technology  

E-Print Network (OSTI)

Ge virtual substrates, fabricated using Si1-xGex-.Ge, compositionally graded buffers, enable the epitaxial growth of device-quality GaAs on Si substrates, but monolithic integration of III-V semiconductors with Si CMOS ...

Dohrman, Carl Lawrence

2008-01-01T23:59:59.000Z

320

Program Session VIII: Quantum Structures II - TMS  

Science Conference Proceedings (OSTI)

Self-Limiting OMCVD Growth of GaAs on V-Grooved Substrates with Application to InGaAs/GaAs Quantum Wires: Giorgio Biasol, Frank Reinhardt, Anders ...

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Critical National Need Idea: High-performance Si-based ...  

Science Conference Proceedings (OSTI)

... These materials can be costly, in part, because of the high cost of single crystalline wafers such as SiC, GaAs, InP, Ge, CdZnTe, and GaSb, that are ...

2011-08-02T23:59:59.000Z

322

Search for Threshold Behavior in DIII-D Electron Heat Transport (A25092)  

E-Print Network (OSTI)

Proc. Of 32nd Euro. Conf. On Plasma Phys., Tarragona, Spain, 2005; General Atomics Report GA-A25092 (2005)32nd EPS Conference on Controlled Fusion and Plasma Physics Tarragona, ES, 2005999610780

Luce, T.C.

2005-07-07T23:59:59.000Z

323

Monolithic heteroepitaxial integration of III-V semiconductor lasers on Si substrates  

E-Print Network (OSTI)

Monolithic optoelectronic integration on silicon-based integrated circuits has to date been limited to date by the large material differences between silicon (Si) and the direct-bandgap GaAs compounds from which optoelectronic ...

Groenert, Michael

2002-01-01T23:59:59.000Z

324

preliminary technical program  

Science Conference Proceedings (OSTI)

Jun 20, 2000 ... 13. 2:40 PM, VII.A.-3. GaAs Single Electron Transistors and Logic Inverters Based on Schottky Wrap Gate Structures: S. Kasai1; H. Hasegawa1;.

325

Conceptual Design of the NGNP Reactor System (A27283)  

E-Print Network (OSTI)

Proc. Of 20th International Conf. On Nuclear Engineering, Anaheim, California, 2012; General Atomics Report GA-A27283 (2012)20th International Conference on Nuclear Engineering Anaheim California, US, 2012999619073

Richards, M.

2012-03-29T23:59:59.000Z

326

Slide 1  

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

Class 2400/1050/950 NGCC 11 90% Wet FGD / Econamine / Gypsum 10 Wet FGD / - / Gypsum Supercritical 3500/1100/1100 9 90% Wet FGD / Econamine / Gypsum 8 Wet FGD / - / Gypsum Subcritical 2400/1050/1050 PC 7 90% Selexol / Selexol / Claus 1800/1050/1050 IGCC 6 Sulfinol-M / - / Claus Shell 5 90% Selexol / Selexol / Claus 4 MDEA / - / Claus CoP E-Gas 3 90% Selexol / Selexol / Claus 2 Selexol / - / Claus GE F Class 1 CO 2 Cap Acid Gas Removal / CO 2 Separation / Sulfur Recovery Gasifier/ Boiler GT ST Cond. (psig/°F/°F) Plant Type Case GEE - GE Energy CoP - Conoco Phillips Carbon Sequestration Conference Presentation-May 8-11, 2006 5 Design Basis: Coal Type Illinois #6 Coal Ultimate Analysis (weight %) As Rec'd Dry Moisture 11.12 0 71.72 5.06 1.41 Chlorine 0.29 0.33 Sulfur 2.51 2.82 Ash 9.70 10.91 Oxygen (by difference) 6.88 7.75 100.0 100.0

327

Microsoft PowerPoint - Proceedings Cover Sheets  

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

Class Class 2400/1050/950 NGCC 11 90% Wet FGD / Econamine / Gypsum 10 Wet FGD / - / Gypsum Supercritical 3500/1100/1100 9 90% Wet FGD / Econamine / Gypsum 8 Wet FGD / - / Gypsum Subcritical 2400/1050/1050 PC 7 90% Selexol / Selexol / Claus 1800/1050/1050 IGCC 6 Sulfinol-M / - / Claus Shell 5 90% Selexol / Selexol / Claus 4 MDEA / - / Claus CoP E-Gas 3 90% Selexol / Selexol / Claus 2 Selexol / - / Claus GE F Class 1 CO 2 Cap Acid Gas Removal/ CO 2 Separation / Sulfur Recovery Gasifier/ Boiler GT ST Cond. (psig/°F/°F) Plant Type Case GEE - GE Energy CoP - Conoco Phillips Carbon Sequestration Conference Presentation-May 8-11, 2006 5 Design Basis: Coal Type 13,126 11,666 HHV (Btu/lb) 100.0 100.0 7.75 6.88 Oxygen (by difference) 10.91 9.70 Ash 2.82 2.51 Sulfur 0.33 0.29 Chlorine 1.41 5.06 71.72 0 Dry 1.25 Nitrogen 4.50 Hydrogen 63.75 Carbon 11.12 Moisture

328

materials analysis of inorganic, organic, and bioma-terials. See ELECTRON MICROSCOPE.  

E-Print Network (OSTI)

plaster is also used in the industry to designate plaster of paris. Plaster is usually applied in one). The finish coat consists of hydrated lime and gypsum plaster (in addition to the water). See LIME (INDUSTRY method of ceramic forming see CERAMICS. When the powdered hemihydrate is mixed with water to form a paste

Anderson, Peter M.

329

IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 8, NO. 2, MARCH 2000 247 A Model of a Bubbling Fluidized Bed Combustor  

E-Print Network (OSTI)

and the capability of using low quality fuel, such as nonpulverized coal, mine residues and waste. Furthermore Prandoni Abstract--Fluidized bed techniques are employed in coal com- bustion power plants, because to produce gypsum). In conventional combustion chambers, the pulverized coal takes less than a second to burn

Campi, Marco

330

Dept. of Sol Science, UW-Madison/UW-Extension, 1525 Observatory Dr., Madison, WI 53706/608-262-0485 November 2010 Issue #2 2010  

E-Print Network (OSTI)

plants burn low S coal and some have installed flue gas scrubbers to reduce sulfur emissions. Use is generated from burning coal. As a consequence of the 1990 Clean Air Act Amendment many coal-burning power power plants in the south- eastern part of the state producing FGD gypsum, with a third to come on

Balser, Teri C.

331

Suboxic deep seawater in the late Paleoproterozoic: Evidence from hematitic chert and iron formation related to seafloor-hydrothermal  

E-Print Network (OSTI)

trona. The high bicar- bonate content of an alkaline soda ocean would have led to Ca depletion in seawater due to precipitation of carbonate minerals, with the evaporation of seawater forming trona rather than gypsum or anhydrite [51,54]. Albite pseudomorphs after trona have been reported from

Bekker, Andrey

332

Annual Report 2011 Annual Report 2011  

E-Print Network (OSTI)

flue gases. This is done by adding ammonia at conditions (~950°C) that favors the reaction of NH3.................................................................................. 75 Hansen, Brian Brun GYPSUM CRYSTALLISATION AND FOAMING IN WET FLUE GAS DESULPHURISATION (FGD .......................................................................................................................... 119 Mogensen, David MATHEMATICAL MODELING OF SOLID OXIDE FUEL CELLS ......................... 123

Mosegaard, Klaus

333

Bacterial mobilization of polonium  

Science Conference Proceedings (OSTI)

Polonium has been observed as the sole {alpha}-emitting nuclide in groundwaters of central Florida, in the absence of its radiogenic parents, at levels of 1,000 dpm/1 or more. Because of the chemical similarity of Po to S (both occupy the same column in the periodic table), studies were begun to determine whether bacteria, particularly those species active in sulfur cycling, could account for the selective solubilization and mobilization of Po. Possible sources of Po are the U-rich phosphate rock and phosphogypsum (gypsum), a byproduct in the manufacture of phosphoric acid. This paper reports on a series of experiments involving the interaction of bacteria with this waste gypsum that resulted in the solubilization of Po. Bacteria were isolated from gypsum that were capable of mediating Po release in column experiments of Po. Bacteria were isolated from gypsum that were capable of mediating Po release in column experiments when fed a growth medium. Sulfate-reducing bacteria were particularly effective at mediating Po release provided the sulfide levels did not rise above 10 {mu}M, in which case Po was apparently coprecipitated as a metal sulfide. Conversely, the ability of sulfate-reducing bacteria to effectively remove dissolved Po when sulfide levels are high suggests that these bacteria may be used as an effective bioremediation tool at reducing groundwater Po levels. 22 refs., 10 figs.

LaRock, P.; Hyun, J.H. [Louisiana State Univ., Baton Rouge, LA (United States)] [Louisiana State Univ., Baton Rouge, LA (United States); Burnett, W.C. [Florida State Univ., Tallahassee, FL (United States)] [and others] [Florida State Univ., Tallahassee, FL (United States); and others

1996-11-01T23:59:59.000Z

334

An Overview of Phosphate Mining and Reclamation in  

E-Print Network (OSTI)

of fertilizer production is phosphogypsum (Equation 1 above). For every ton of fertilizer produced, 4.5 tons of phosphogypsum (CaSO4) are produced. While gypsum can be used for many products, the EPA does not allow the use-mine landscapes will look like that, or they see the CSAs and phosphogypsum stacks as permanent scars marring

Jawitz, James W.

335

Process for purifying phosphogysum  

Science Conference Proceedings (OSTI)

A process for reducing radioactive contamination of phosphogypsum. Phosphogypsum containing radioactive material is calcined to form hemihydrate crystals carrying the radioactive contaminants, and a portion of the crystals is converted to substantially radiation-free gypsum crystals which are readily separated from the hemihydrate crystal relics containing substantially all of the radioactive contamination.

Palmer, J.W.; Gaynor, J.C.

1983-12-20T23:59:59.000Z

336

DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited  

E-Print Network (OSTI)

reinforcement corrosion in reinforced concrete, recycling and reuse of waste materials and industrial by materials, and waste management. He developed new types of cements based on calcined clays and laterites, insoluble gypsum, and binders for wastes immobilization. To date, more than 200 scientific papers

US Army Corps of Engineers

337

" Level: National Data;" " ...  

U.S. Energy Information Administration (EIA) Indexed Site

Lime",60,0,0,0,0,0,0,0,0,0,0 327420," Gypsum","*",0,0,0,0,0,0,0,0,0,0 327993," Mineral Wool",0,0,0,0,0,0,0,0,0,0,0 331,"Primary Metals",3097,545,15,530,0,0,0,0,0,0,0 331111," Iron...

338

Released: March 2013  

U.S. Energy Information Administration (EIA) Indexed Site

,5,"*",5,3,"*",77,1,9,0 327420," Gypsum",44,5,"*","*",39,"*",0,0,"*",0 327993," Mineral Wool",39,12,0,"*",24,"*",0,3,"*",0 331,"Primary Metals",1608,400,1,9,566,3,356,314,92,133...

339

Table 7.6 Quantity of Purchased Energy Sources, 2010;  

U.S. Energy Information Administration (EIA) Indexed Site

Lime 103 1,502 * 1 3 * 4 * 9 327420 Gypsum 43 1,384 * * 37 * 0 0 * 327993 Mineral Wool 39 3,408 0 * 24 * 0 * * 331 Primary Metals 1,820 120,608 * 1 548 1 17 11 102 331111...

340

Level: National Data; Row: NAICS Codes; Column: Energy Sources  

Gasoline and Diesel Fuel Update (EIA)

0 W 0 0 0 0 W 327410 Lime 4 0 W 0 4 0 0 W 327420 Gypsum 0 0 0 0 0 0 0 0 327993 Mineral Wool 9 0 W W 4 0 0 W 331 Primary Metals 299 W 5 59 64 35 30 153 331111 Iron and Steel Mills...

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Released: June 2010  

U.S. Energy Information Administration (EIA) Indexed Site

327410," Lime","W",0,"W",0,0,"W",0,0 327420," Gypsum",0,0,0,0,0,0,0,0 327993," Mineral Wool","W","W",0,0,0,0,0,0 331,"Primary Metals",52,5,7,"W",5,11,6,"W" 331111," Iron and Steel...

342

Originally Released: July 2009  

Annual Energy Outlook 2012 (EIA)

5 77 327410 Lime 116 5 * 1 5 * 78 4 22 327420 Gypsum 86 6 * 1 76 * 0 0 2 327993 Mineral Wool 51 14 0 * 34 * 0 3 * 331 Primary Metals 1,744 R 458 19 6 585 R 4 21 359 292 331111 Iron...

343

Released: May 2013  

U.S. Energy Information Administration (EIA) Indexed Site

1502,1424,77,3,2,1,0,0,0 327420," Gypsum",1384,1174,210,37,16,20,0,0,0 327993," Mineral Wool",3408,2726,682,24,10,13,129,0,129 331,"Primary Metals",120608,97623,22985,548,172,376,1...

344

Released: June 2010  

U.S. Energy Information Administration (EIA) Indexed Site

Lime",4,"W","W",0,0,0,0,0 327420," Gypsum",18,"Q",0,0,0,0,10,0 327993," Mineral Wool",8,"W",0,"W",0,0,"W","W" 331,"Primary Metals",387,61,46,79,30,49,107,7 331111," Iron...

345

Originally Released: July 2009  

Annual Energy Outlook 2012 (EIA)

327410 Lime 116 5 * 1 5 * 78 4 22 0 327420 Gypsum 86 6 * 1 76 * 0 0 2 0 327993 Mineral Wool 51 14 0 * 35 * 0 3 * 0 331 Primary Metals 1,736 R 458 19 7 627 R 4 373 253 139 R 145...

346

Released: June 2010  

U.S. Energy Information Administration (EIA) Indexed Site

327410," Lime","W",0,"W",0,0,0,"W",0 327420," Gypsum",0,0,0,0,0,0,0,0 327993," Mineral Wool",0,0,0,0,0,0,0,0 331,"Primary Metals",5,0,3,0,0,0,3,0 331111," Iron and Steel...

347

Originally Released: July 2009  

Annual Energy Outlook 2012 (EIA)

Lime 116 1,431 * * 5 * 4 * 22 0 327420 Gypsum 86 1,845 * * 74 * 0 0 2 0 327993 Mineral Wool 51 4,032 0 * 34 * 0 * * 0 331 Primary Metals 1,736 R 134,325 R 3 1 609 R 1 17 10 139 R...

348

" Level: National Data;" " ...  

U.S. Energy Information Administration (EIA) Indexed Site

,6,5,2,0,0,"*",0,3,0,0,"*" 327420," Gypsum",70,61,61,0,0,0,0,0,0,0,"*" 327993," Mineral Wool",27,22,16,"*",2,"*",0,1,0,0,3 331,"Primary Metals",979,596,344,4,2,12,2,4,0,3,225...

349

Released: July 2009  

U.S. Energy Information Administration (EIA) Indexed Site

"X",0,"X",0,"X","X",0 327420," Gypsum","X","X","X","X","X","X","X","X" 327993," Mineral Wool",0,"X",0,0,0,"X","X",0 331,"Primary Metals",6,0,0,0.3,14.6,0,0.2,38.7 331111," Iron and...

350

Released: June 2010  

U.S. Energy Information Administration (EIA) Indexed Site

Lime","W",0,0,"W",0,0,0,0 327420," Gypsum","Q","Q",0,0,0,0,0,0 327993," Mineral Wool",6,3,0,"W",0,0,"W",0 331,"Primary Metals",163,38,14,31,18,22,22,7 331111," Iron and...

351

Released: June 2010  

U.S. Energy Information Administration (EIA) Indexed Site

Lime",12,"W","W","W","W",0,4,"W" 327420," Gypsum",0,0,0,0,0,0,0,0 327993," Mineral Wool",0,0,0,0,0,0,0,0 331,"Primary Metals",6,"W",0,"W",0,0,"W",0 331111," Iron and Steel...

352

JEBYNPROJEKTET -ekologisk produktion av livsmedel  

E-Print Network (OSTI)

/Composite Other Inorganic (a) Inerts (I) Rocks (2) Concrete (3) Brick (4) Soil & Fines (5) Asphalt (6) Gypsum crew. Therefore, it is important to establish a "buddy system" where waste sorters are grouped leader may program the scales accordingly. 343 When a sorter has a question regarding the material type

353

Service Building 4 Building Room Material Amount Percentage Priority Action  

E-Print Network (OSTI)

Service Building 4 Building Room Material Amount Percentage Priority Action Service Building 4 S160 65 sqft 15.00 P5 Manage S1J74 Friday, February 18, 2011 Page 1 of 2 #12;Building Room Material Amount Manage Mechanical Insulation 100 LF 55.00 P5 Manage Service Buliding 4 S16H6A Gypsum Wallboard Joint

Seldin, Jonathan P.

354

New GaInP/GaAs/GaInAs, Triple-Bandgap, Tandem Solar Cell for High-Efficiency Terrestrial Concentrator Systems  

DOE Green Energy (OSTI)

GaInP/GaAs/GaInAs three-junction cells are grown in an inverted configuration on GaAs, allowing high quality growth of the lattice matched GaInP and GaAs layers before a grade is used for the 1-eV GaInAs layer. Using this approach an efficiency of 37.9% was demonstrated.

Kurtz, S.; Wanlass, M.; Kramer, C.; Young, M.; Geisz, J.; Ward, S.; Duda, A.; Moriarty, T.; Carapella, J.; Ahrenkiel, P.; Emery. K.; Jones, K.; Romero, M.; Kibbler, A.; Olson, J.; Friedman, D.; McMahon, W.; Ptak, A.

2005-11-01T23:59:59.000Z

355

Accumulation and replacement of exchangeable sodium in soils of Southeast Texas under turfgrass and its effect on soil infiltration rate  

E-Print Network (OSTI)

Many municipal water supplies in Southeast Texas have a relatively high level of Ne and low total dissolved solids. Smectitic clays which respond to wetting by swelling, especially when wetted with high Na waters of low salinity are the major clays in soils of this area. This study assessed the degree of Na accumulation on cation exchange sites as affected by gypsum treatments in soils that support turfgrass (bermudagrass) and the response of soil infiltration rate to different rates of gypsum amendment by using rainfall simulation. A field experiment was conducted on a sodic, non-saline Boonville soil (fine, montmorillonitic, thennic Ruptic Vertic Albaqualf) amended with gypsum at rates equivalent to 5 0%, I 00% and 200% of the exchangeable Na in the soil to a depth of 15 cm. Application of gypsum resulted in similar infiltration rates (IR) which were lower than the untreated plots suggesting a significant difference between treated and untreated soils 9 wk after application. However, at 36 wk after application, treated and untreated soils had similar IR with no statistical difference between treatments. Soils of the study area varied somewhat in textural class, but generally had more than 20 % clay within the 0-IO cm depth. Clay content in the 0-10 cm depth was not correlated with IR at the 20-min measurement. These results suggest the channels developed by roots may enable water to enter the soil in spite of clay content and degree of sodic character. The gypsum treatments statistically affected the levels of extractable Ca and Na in some plots and some depths. Treated plots had higher extractable Ca than untreated plots for the 01 0 cm depth for all sites, but treatment rates did not show a significant difference for each site in the same depth. Levels of extractable Na were statistically lower for treated plots than untreated ones for the 0-I 0 cm depth at all sites. For all sites gypsum application did not have significant effects on levels of extractable Mg and K at all depths and times. Even though the pH of the soils tended to decrease with application of gypsum, untreated soils also showed a decrease in pH over the course of the study and pH was not statistically significant.

Aydemir, Salih

1996-01-01T23:59:59.000Z

356

Plating on difficult-to-plate metals: what's new  

SciTech Connect

Some of the changes since 1970 in procedures for plating on such materials as titanium, molybdenum, silicon, aluminum, and gallium arsenide are summarized. While basic procedures for plating some of these materials were developed as many as 30 to 40 years ago, changes in the end uses of the plated products have necessitated new plating processes. In some cases, vacuum techniques - such as ion bombardment, ion implantation, and vacuum metallization - have been introduced to improve the adhesion of electrodeposits. In other cases, these techniques have been used to deposit materials upon which electrodeposits are required.

Wiesner, H.J.

1980-07-30T23:59:59.000Z

357

Quantum interference and control of the dynamic Franz-Keldysh effect: Generation and detection of terahertz space-charge fields  

Science Conference Proceedings (OSTI)

The Dynamic Franz Keldysh Effect (DFKE) is produced and controlled in bulk gallium arsenide by quantum interference without the aid of externally applied fields and is spatially and temporally resolved using ellipsometric pump-probe techniques. The {approx}3 THz internal driving field for the DFKE is a transient space-charge field that is associated with a critically damped coherent plasma oscillation produced by oppositely traveling ballistic electron and hole currents that are injected by two-color quantum interference techniques. The relative phase and polarization of the two pump pulses can be used to control the DFKE.

Wang, Rui [Laboratory for Photonics and Quantum Electronics, 138 IATL, University of Iowa, Iowa City, Iowa 52242 (United States) [Laboratory for Photonics and Quantum Electronics, 138 IATL, University of Iowa, Iowa City, Iowa 52242 (United States); Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045 (United States); Jacobs, Paul; Smirl, Arthur L. [Laboratory for Photonics and Quantum Electronics, 138 IATL, University of Iowa, Iowa City, Iowa 52242 (United States)] [Laboratory for Photonics and Quantum Electronics, 138 IATL, University of Iowa, Iowa City, Iowa 52242 (United States); Zhao, Hui [Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045 (United States)] [Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045 (United States)

2013-06-24T23:59:59.000Z

358

Nanobeam Photonic Crystal Cavity Light-Emitting Diodes  

E-Print Network (OSTI)

We present results on electrically driven nanobeam photonic crystal cavities formed out of a lateral p-i-n junction in gallium arsenide. Despite their small conducting dimensions, nanobeams have robust electrical properties with high current densities possible at low drive powers. Much like their two-dimensional counterparts, the nanobeam cavities exhibit bright electroluminescence at room temperature from embedded 1,250 nm InAs quantum dots. A small room temperature differential gain is observed in the cavities with minor beam self-heating suggesting that lasing is possible. These results open the door for efficient electrical control of active nanobeam cavities for diverse nanophotonic applications.

Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

2011-01-01T23:59:59.000Z

359

The state of the art of thin-film photovoltaics  

DOE Green Energy (OSTI)

Thin-film photovoltaic technologies, based on materials such as amorphous or polycrystalline silicon, copper indium diselenide, cadmium telluride, and gallium arsenide, offer the potential for significantly reducing the cost of electricity generated by photovoltaics. The significant progress in the technologies, from the laboratory to the marketplace, is reviewed. The common concerns and questions raised about thin films are addressed. Based on the progress to date and the potential of these technologies, along with continuing investments by the private sector to commercialize the technologies, one can conclude that thin-film PV will provide a competitive alternative for large-scale power generation in the future.

Surek, T.

1993-10-01T23:59:59.000Z

360

Final Site-wide Environmental Impact Statement for Continued Operation of Lawrence Livermore National Laboratory and Supplemental Stockpile Stewardship and Management Programmatic Environmental Impact Statement  

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

SW/SPEIS Chapter 4 - Description of the Existing Environment SW/SPEIS Chapter 4 - Description of the Existing Environment March 2005 4.9-9 TABLE 4.9.3-1.-Federal and California Species with Protected or Sensitive Status Known to Occur at the Livermore Site and Site 300 in 2001 and 2002 Site Status Common Name Livermore Site Site 300 Federal Status Code State Status Code Plants Big tarplant a - X - CNPS List 1 B Hogwallow starfish - X - CNPS List 4 Large-flowered fiddleneck - X FE (CH) CNPS List 1 B Round-leaved filaree - X - CNPS List 2 Stinkbells - X - CNPS List 4 Diamond-petaled poppy - X FSC CNPS List 1 B Gypsum rock jasmine - X - CNPS List 4 Gypsum loving larkspur - X - CNPS List 4 Invertebrates Valley elderberry longhorn beetle - X FT - California linderiella fairy shrimp - X FSC - Amphibians

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Supplemental Record of Decision; Savannah River Site Waste  

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

241 241 Federal Register / Vol. 62, No. 96 / Monday, May 19, 1997 / Notices [FR Doc. 97-13033 Filed 5-16-97; 8:45 am] BILLING CODE 6450-01-P DEPARTMENT OF ENERGY [FE Docket No. 97-35-NG] Office of Fossil Energy; United States Gypsum Company; Order Granting Long-Term Authorization To Import Natural Gas From Canada AGENCY: Office of Fossil Energy, DOE. ACTION: Notice of order. SUMMARY: The Office of Fossil Energy of the Department of Energy gives notice that it has issued DOE/FE Order No. 1272 on May 6, 1997, granting United States Gypsum Company a ten-year authorization to import from Canada up to 5,000,000 Mcf per year (approximately 13,600 Mcf per day) of natural gas from November 1, 1998, through November 1, 2008. This natural gas will be purchased from Husky Oil Operations, Ltd., and may be imported

362

Microsoft Word - 42080DraftFinalReport060608.doc  

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

Fate of Mercury in Synthetic Gypsum Used for Fate of Mercury in Synthetic Gypsum Used for Wallboard Production Final Report Prepared by: Jessica Sanderson USG Corporation Gary M. Blythe and Mandi Richardson URS Corporation June 2008 Cooperative Agreement No: DE-FC26-04NT42080 USG Corporation 550 West Adams Street Chicago, Illinois 60661 Prepared for: Charles Miller National Energy Technology Laboratory U.S. Department of Energy 626 Cochrans Mill Road Pittsburgh, Pennsylvania 15236 iii DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus,

363

LOS ALAMOS, N.M., January 15, 2013-Researchers from Los Alamos National  

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

follows the 'Yellowknife follows the 'Yellowknife Road' to Martian wet area January 15, 2013 Instrument confirms presence of gypsum and related minerals LOS ALAMOS, N.M., January 15, 2013-Researchers from Los Alamos National Laboratory and the French Space Agency have tracked a trail of minerals that point to the prior presence of water at the Curiosity rover site on Mars. Researchers from the Mars Science Laboratory's ChemCam team today described how the laser instrument aboard the Curiosity Rover-an SUV-sized vehicle studying the surface of the Red Planet-has detected veins of gypsum running through an area known as Yellowknife Bay, located some 700 meters away from where the Curiosity Rover landed five months ago. - 2 - "These veins are composed mainly of hydrated calcium sulfate, such as bassanite

364

HYDRAULIC CEMENT PREPARATION FROM LURGI SPENT SHALE  

SciTech Connect

Low cost material is needed for grouting abandoned retorts. Experimental work has shown that a hydraulic cement can be produced from Lurgi spent shale by mixing it in a 1:1 weight ratio with limestone and heating one hour at 1000°C. With 5% added gypsum, strengths up to 25.8 MPa are obtained. This cement could make an economical addition up to about 10% to spent shale grout mixes, or be used in ordinary cement applications.

Mehta, P.K.; Persoff, P.; Fox, J.P.

1980-06-01T23:59:59.000Z

365

2011 Update on Mercury Capture by Wet FGD  

Science Conference Proceedings (OSTI)

This document describes recent progress on three EPRI-funded flue gas desulfurization (FGD) research and development projects. The three projects are focused on understanding and enhancing how mercury is captured by FGD systems; on how it partitions between the FGD liquor, fine solids, and bulk FGD solid byproduct; and/or on factors that may affect beneficial use of FGD gypsum. The first project is collecting data at bench scale to determine the reactions that control the changes oxidized mercury can und...

2011-12-21T23:59:59.000Z

366

International Earth Science Colloquium on the Aegean Region (1-5 October 2012, zmir, Turkey)  

E-Print Network (OSTI)

by a white efflorescent crust of halite crystals containing trona (Na(CO3) (HCO3).2H2O), gaylussite (Na2Ca accompanying halite. They can be grouped as Na-bearing carbonates (trona (Na(CO3)(HCO3).2H2O); nahcolite (Na formed by a sandy mixture with halite and ulexite, and minor amounts of dolomite, calcite, trona, gypsum

Seyitoðlu, Gürol

367

Optimal Configuration of Chemical Complexes Based on Economic,  

E-Print Network (OSTI)

chloride rather than gypsum Potassium chloride Trona process IMCC process Sylvinite ore plant #12-2,839,000 na 0 Acetic Acid 0-90,000 na 90,000 Trona KCl 0-578,610,000 na 39,706,000 IMCC KCl 0-1,4251,000 na 0 values Best to obtain KCl from the Trona plant Acetic acid plant was operating at the upper limit Profit

Pike, Ralph W.

368

A Prototype System for Economic, Environmental and Sustainable Optimization  

E-Print Network (OSTI)

chloride rather than gypsum Potassium chloride Trona process IMCC process Sylvinite ore plant #12-2,839,000 na 0 Acetic Acid 0-90,000 na 9.00E+04 Trona (S93) 0-578,610,000 na 3.97E+07 IMCC (S89) 0 KCl from the Trona plant Acetic acid plant was operating at the upper limit Profit declines

Pike, Ralph W.

369

Experimental and Analytical Research on Fracture Processes in ROck  

DOE Green Energy (OSTI)

Experimental studies on fracture propagation and coalescence were conducted which together with previous tests by this group on gypsum and marble, provide information on fracturing. Specifically, different fracture geometries wsere tested, which together with the different material properties will provide the basis for analytical/numerical modeling. INitial steps on the models were made as were initial investigations on the effect of pressurized water on fracture coalescence.

Herbert H.. Einstein; Jay Miller; Bruno Silva

2009-02-27T23:59:59.000Z

370

A Review of Agricultural and Other Land Application Uses of Flue Gas Desulfurization Products  

Science Conference Proceedings (OSTI)

The production of flue gas desulfurization (FGD) products, especially FGD gypsum, is expected to increase substantially over the next ten to twenty years in response to clean air initiatives. There are a large number of agricultural and other land application uses of FGD products that have received previous research and development attention, but only in specific locations of the United States and under limited conditions of crops, climate and soil types. This report discusses current and potential futur...

2006-03-13T23:59:59.000Z

371

,,,"Electricity","from Sources",,"Natural Gas","from Sources...  

U.S. Energy Information Administration (EIA) Indexed Site

"X",0,0,0,"X","X","X" 327420," Gypsum",1.6,2.4,1.7,0.1,0.8,0.1,0,"X",0 327993," Mineral Wool",0.5,0.5,1.9,0.2,0.4,0.3,"X","X","X" 331,"Primary Metals",0.7,0.8,1.4,0.7,1.1,0.9,0.1,0...

372

Released: June 2010  

U.S. Energy Information Administration (EIA) Indexed Site

0,0,"X",0,0,0,"X","X","X" 327420," Gypsum",1.5,2,1.9,0.1,0.3,0,0,"X",0 327993," Mineral Wool",0.3,0.3,2.7,0.2,0.3,0.2,"X","X","X" 331,"Primary Metals",0.6,0.6,0.7,0.7,0.9,0.9,0.1,0...

373

Released: June 2010  

U.S. Energy Information Administration (EIA) Indexed Site

0,"X",0,0,0,"X","X","X" 327420," Gypsum",1.6,2.4,1.7,0.1,0.4,0,0,"X",0 327993," Mineral Wool",0.5,0.5,1.9,0.2,0.4,0.2,"X","X","X" 331,"Primary Metals",0.7,0.8,1.4,0.7,1,0.9,0.1,0.2...

374

"Code(a)","Subsector and Industry","Total","Electricity","Fuel...  

U.S. Energy Information Administration (EIA) Indexed Site

me",0,0,0,0,0,0,0,0,0 327420," Gypsum",0.3,1.6,0,0,0.1,2.9,"X","X",0.1 327993," Mineral Wool",0.3,0.5,"X",2.7,0.2,2.2,"X",3,0.1 331,"Primary Metals",0.5,0.7,0.1,1.7,0.7,4,0,0.2,0.4...

375

Coal combustion products 2007 production and use report  

Science Conference Proceedings (OSTI)

The American Coal Ash Association's 2007 Annual Coal Combustion Products (CCP) are derived from data from more than 170 power plants. The amount of CCPs used was 40.55%, a decrease of 2.88% from 2006, attributed to reduced fuel burn and a decrease in demand in the building industry. Figures are given for the production of fly ash, flue gas desulfurization gypsum, bottom ash, FBC ash and boiler slag. The article summarises results of the survey. 1 ref., 1 tab.

NONE

2009-07-01T23:59:59.000Z

376

Molten Salt Synthesis and High Rate Performance of the ‘‘Desert-Rose’’ form of LiCoO2  

SciTech Connect

The synthesis of a novel nanostructure of LiCoO{sub 2}, and its performance as a cathode for a high-rate lithium ion battery, is described. The LiCoO{sub 2} nanostructure resembles the morphology of a known natural mineral: 'desert rose' gypsum. A range of measurement techniques are used to investigate the growth mechanism of this structure and the origin of its high rate charge/discharge properties.

H Chen; C Grey

2011-12-31T23:59:59.000Z

377

Building America Top Innovations Hall of Fame Profile Â… Attic Air Sealing Guidelines  

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

Terminology Terminology Air Barrier Material (ABM) --- A does not allow air to pass throu plywood/OSB, foam board, duc lumber. Backing --- Any material that s be sprayed so as to provide an glass batts. Baffle (B) --- Manufactured chu direct ventilation air flow up an foam board or cardboard. Thermal Blocking --- Any rigid heat sources like chimneys or metal and gypsum board. Fasteners --- Staples, screws o

378

Comparison of Coal Combustion Products to Other Common Materials  

Science Conference Proceedings (OSTI)

The chemical characteristics of coal combustion products (CCPs) are often discussed with reference to geologic materials and other industrial by-products; however, there are no systematic comparisons of these materials in the literature. This report compares the ranges in chemical characteristics of fly ash, bottom ash, and flue gas desulfurization (FGD) gypsum to the ranges observed for soil and rock, as well as other common products and by-products.

2010-09-30T23:59:59.000Z

379

Direct imaging of the structural domains in the iron pnictides AFe[subscript 2]As[subscript 2] (A=Ca, Sr, Ba)  

SciTech Connect

The parent compounds of recently discovered iron-arsenide superconductors, AFe{sub 2}As{sub 2} with alkaline earth A=Ca,Sr,Ba, undergo simultaneous structural and magnetic phase transitions at a temperature T{sub SM}. Using a combination of polarized light microscopy and spatially resolved high-energy synchrotron x-ray diffraction we show that the orthorhombic distortion leads to the formation of 45{sup o}-type structural domains in all parent compounds. Domains penetrate through the sample thickness in the c direction and are not affected by crystal imperfections such as growth terraces. The domains form regular stripe patterns in the plane with a characteristic dimension of 10--50 {mu}m. The direction of the stripes is fixed with respect to the tetragonal (100) and (010) directions but can change by 90{sup o} on thermal cycling through the transition. This domain pattern may have profound implications for intrinsic disorder and anisotropy of iron arsenides.

Tanatar, M.A.; Kreyssig, A.; Nandi, S.; Ni, N.; Bud'ko, S.L.; Canfield, P.C.; Goldman, A.I.; Prozorov, R.; (Ames)

2009-06-29T23:59:59.000Z

380

Monitoring interfacial dynamics by pulsed laser techniques. Final report  

DOE Green Energy (OSTI)

The research is aimed at understanding the structural, electronic, and reactive properties of semiconductors in solutions. Focus is on Si and GaAs surfaces because they are used in photovoltaic devices, etc. The pulsed laser techniques used included surface second harmonic generation in Si and laser induced photoluminescence in GaAs. SHG can measure space charge effects in the semiconductor under various conditions, ie, immersed in electrolyte, in presence of oxide overlayers, and under UHV conditions. The Si studies demonstrated the sensitivity of the phase of the SH response to space charge effects. With GaAs, time-correlated single photon counting methods were used in the picosecond time regime to examine the recombination luminescence following above band gap excitation (surface trapping velocities).

Richmond, G.

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Intense terahertz emission from molecular beam epitaxy-grown GaAs/GaSb(001)  

SciTech Connect

Intense terahertz (THz) electromagnetic wave emission was observed in undoped GaAs thin films deposited on (100) n-GaSb substrates via molecular beam epitaxy. GaAs/n-GaSb heterostructures were found to be viable THz sources having signal amplitude 75% that of bulk p-InAs. The GaAs films were grown by interruption method during the growth initiation and using various metamorphic buffer layers. Reciprocal space maps revealed that the GaAs epilayers are tensile relaxed. Defects at the i-GaAs/n-GaSb interface were confirmed by scanning electron microscope images. Band calculations were performed to infer the depletion region and electric field at the i-GaAs/n-GaSb and the air-GaAs interfaces. However, the resulting band calculations were found to be insufficient to explain the THz emission. The enhanced THz emission is currently attributed to a piezoelectric field induced by incoherent strain and defects.

Sadia, Cyril P.; Laganapan, Aleena Maria; Agatha Tumanguil, Mae; Estacio, Elmer; Somintac, Armando; Salvador, Arnel [National Institute of Physics, University of the Philippines Diliman, Quezon City 1101 (Philippines); Que, Christopher T. [Physics Department, De La Salle University, 2401 Taft Avenue, Manila 1004 (Philippines); Yamamoto, Kohji; Tani, Masahiko [Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507 (Japan)

2012-12-15T23:59:59.000Z

382

Improved substrate structures for InP-based devices  

DOE Patents (OSTI)

A substrate structure for an InP-based semiconductor device having an InP-based film is disclosed. The substrate structure includes a substrate region having a light-weight bulk substrate and an upper GaAs layer. An interconnecting region is disposed between the substrate region and the InP-based device. The interconnecting region includes a compositionally graded intermediate layer substantially lattice matched at its one end to the GaAs layer and substantially lattice matched at its opposite end to the InP-based film. The interconnecting region further includes a dislocation mechanism disposed between the GaAs layer and the InP-based film in cooperation with the graded intermediate layer, the buffer mechanism blocking and inhibiting propagation of threading dislocations between the substrate region and the InP-based device. 1 fig.

Wanlass, M.; Sheldon, P.

1988-09-30T23:59:59.000Z

383

Substrate structures for InP-based devices  

DOE Patents (OSTI)

A substrate structure for an InP-based semiconductor device having an InP based film is disclosed. The substrate structure includes a substrate region having a lightweight bulk substrate and an upper GaAs layer. An interconnecting region is disposed between the substrate region and the InP-based device. The interconnecting region includes a compositionally graded intermediate layer substantially lattice-matched at one end to the GaAs layer and substantially lattice-matched at the opposite end to the InP-based film. The interconnecting region further includes a dislocation mechanism disposed between the GaAs layer and the InP-based film in cooperation with the graded intermediate layer, the buffer mechanism blocking and inhibiting propagation of threading dislocations between the substrate region, and the InP-based device.

Wanlass, Mark W. (Golden, CO); Sheldon, Peter (Lakewood, CO)

1990-01-01T23:59:59.000Z

384

Loadbearing Capacity of Cold Formed Steel Joists Subjected to Severe Heating  

E-Print Network (OSTI)

This paper discusses the behaviour of lightweight steel framed (LSF) unrestrained floors, protected with gypsum board ceilings, in five standard fire resistance tests. Parameters investigated in this test series were joist spacing, number of gypsum board layers in the ceiling membrane, floor cavity insulation and presence of concrete topping in the sub-floor. The fire resistance of LSF floors appears to be essentially governed by the ability of gypsum board to remain in place under fire exposure; other factors are of secondary importance. Retrospective numerical thermal-structural simulations of these tests show good agreement with measured temperature and deformation histories. The development of floor deflections is governed by the thermal bowing of steel joists except for the last one or two minutes in the tests, when "run-away" deformations develop due to the formation of inelastic hinges near mid-span. Evaluation of bending moment resistance of heated joists using current design provisions for cold formed steel structures, adjusted to account for the deterioration of strength and stiffness of steel at elevated temperatures, leads to conservative and fairly accurate predictions of fire resistance.

M.A. Sultan; Steel Joists; Subjected To; Severe Heating; F. Alfawakhiri; Mohamed A. Sultan

2001-01-01T23:59:59.000Z

385

DPAL: A New Class of Lasers for CW Power Beaming at Ideal Photovoltaic Cell Wavelengths  

DOE Green Energy (OSTI)

The new class of diode pumped alkali vapor lasers (DPALs) offers high efficiency cw laser beams at wavelengths which efficiently couple to photovoltaic (PV) cells: silicon cells at 895 nm (cesium), and GaAs cells at 795 nm (rubidium) and at 770 nm (potassium). DPAL electrical efficiencies of 25-30% are projected, enabling PV cell efficiencies {approx}40% (Si) and {approx}60% (GaAs). Near-diffraction-limited DPAL device power scaling into the multi-kilowatt regime from a single aperture is projected.

Krupke, W F; Beach, R J; Payne, S A; Kanz, V K; Early, J T

2003-09-15T23:59:59.000Z

386

Suppression of nuclear spin diffusion at a GaAs/AlGaAs interface measured with a single quantum dot nano-probe  

E-Print Network (OSTI)

Nuclear spin polarization dynamics are measured in optically pumped individual GaAs/AlGaAs interface quantum dots by detecting the time-dependence of the Overhauser shift in photoluminescence (PL) spectra. Long nuclear polarization decay times of ~ 1 minute have been found indicating inefficient nuclear spin diffusion from the GaAs dot into the surrounding AlGaAs matrix in externally applied magnetic field. A spin diffusion coefficient two orders lower than that previously found in bulk GaAs is deduced.

A. E. Nikolaenko; E. A. Chekhovich; M. N. Makhonin; I. W. Drouzas; A. B. Vankov; J. Skiba-Szymanska; M. S. Skolnick; P. Senellart; A. Lemaitre; A. I. Tartakovskii

2009-01-15T23:59:59.000Z

387

Current-matched high-efficiency, multijunction monolithic solar cells  

DOE Patents (OSTI)

The efficiency of a two-junction (cascade) tandem photovoltaic device is improved by adjusting (decreasing) the top cell thickness to achieve current matching. An example of the invention was fabricated out of Ga.sub.0.52 In.sub.0.48 P and GaAs. Additional lattice-matched systems to which the invention pertains include Al.sub.x Ga.sub.1-x /GaAS (x= 0.3-0.4), GaAs/Ge and Ga.sub.y In.sub.l-y P/Ga.sub.y+0.5 In.sub.0.5-y As (0

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

1993-01-01T23:59:59.000Z

388

APPLIED PHYTO-REMEDIATION TECHNIQUES USING HALOPHYTES FOR OIL AND BRINE SPILL SCARS  

SciTech Connect

Produced salt water from historical oil and gas production was often managed with inadequate care and unfortunate consequences. In Kansas, the production practices in the 1930's and 1940's--before statewide anti-pollution laws--were such that fluids were often produced to surface impoundments where the oil would segregate from the salt water. The oil was pumped off the pits and the salt water was able to infiltrate into the subsurface soil zones and underlying bedrock. Over the years, oil producing practices were changed so that segregation of fluids was accomplished in steel tanks and salt water was isolated from the natural environment. But before that could happen, significant areas of the state were scarred by salt water. These areas are now in need of economical remediation. Remediation of salt scarred land can be facilitated with soil amendments, land management, and selection of appropriate salt tolerant plants. Current research on the salt scars around the old Leon Waterflood, in Butler County, Kansas show the relative efficiency of remediation options. Based upon these research findings, it is possible to recommend cost efficient remediation techniques for slight, medium, and heavy salt water damaged soil. Slight salt damage includes soils with Electrical Conductivity (EC) values of 4.0 mS/cm or less. Operators can treat these soils with sufficient amounts of gypsum, install irrigation systems, and till the soil. Appropriate plants can be introduced via transplants or seeded. Medium salt damage includes soils with EC values between 4.0 and 16 mS/cm. Operators will add amendments of gypsum, till the soil, and arrange for irrigation. Some particularly salt tolerant plants can be added but most planting ought to be reserved until the second season of remediation. Severe salt damage includes soil with EC values in excess of 16 mS/cm. Operators will add at least part of the gypsum required, till the soil, and arrange for irrigation. The following seasons more gypsum will be added and as the soil EC is reduced, plants can be introduced. If rapid remediation is required, a sufficient volume of topsoil, or sand, or manure can be added to dilute the local salinity, the bulk amendments tilled into the surface with added gypsum, and appropriate plants added. In this case, irrigation will be particularly important. The expense of the more rapid remediation will be much higher.

M.L. Korphage; Bruce G. Langhus; Scott Campbell

2003-03-01T23:59:59.000Z

389

Field Testing of Nano-PCM Enhanced Building Envelope Components  

SciTech Connect

The U.S. Department of Energy s (DOE) Building Technologies Program s goal of developing high-performance, energy efficient buildings will require more cost-effective, durable, energy efficient building envelopes. Forty-eight percent of the residential end-use energy consumption is spent on space heating and air conditioning. Reducing envelope-generated heating and cooling loads through application of phase change material (PCM)-enhanced envelope components can facilitate maximizing the energy efficiency of buildings. Field-testing of prototype envelope components is an important step in estimating their energy benefits. An innovative phase change material (nano-PCM) was developed with PCM encapsulated with expanded graphite (interconnected) nanosheets, which is highly conducive for enhanced thermal storage and energy distribution, and is shape-stable for convenient incorporation into lightweight building components. During 2012, two test walls with cellulose cavity insulation and prototype PCM-enhanced interior wallboards were installed in a natural exposure test (NET) facility at Charleston, SC. The first test wall was divided into four sections, which were separated by wood studs and thin layers of foam insulation. Two sections contained nano-PCM-enhanced wallboards: one was a three-layer structure, in which nano-PCM was sandwiched between two gypsum boards, and the other one had PCM dispersed homogeneously throughout graphite nanosheets-enhanced gypsum board. The second test wall also contained two sections with interior PCM wallboards; one contained nano-PCM dispersed homogeneously in gypsum and the other was gypsum board containing a commercial microencapsulated PCM (MEPCM) for comparison. Each test wall contained a section covered with gypsum board on the interior side, which served as control or a baseline for evaluation of the PCM wallboards. The walls were instrumented with arrays of thermocouples and heat flux transducers. Further, numerical modeling of the walls containing the nano-PCM wallboards were performed to determine their actual impact on wall-generated heating and cooling loads. The models were first validated using field data, and then used to perform annual simulations using Typical Meteorological Year (TMY) weather data. This article presents the measured performance and numerical analysis to evaluate the energy-saving potential of the nano-PCM-enhanced building components.

Biswas, Kaushik [ORNL; Childs, Phillip W [ORNL; Atchley, Jerald Allen [ORNL

2013-08-01T23:59:59.000Z

390

Wednesday Afternoon Sessions (June 26) - TMS  

Science Conference Proceedings (OSTI)

... of 70 mW at room temperature for 260 um cavity length and a differential quantum .... "Polycrystalline MBE-Grown GaAs for Solar Cells:" D.J. FRIEDMAN, S.R. .... low noise applications including receivers, transmitters, and OEICs is clear.

391

Quantum wells on indium gallium arsenic compositionally graded buffers realized by molecular beam epitaxy  

E-Print Network (OSTI)

For a long time, there has been a desire to extend the emission wavelength of GaAs-based quantum well lasers, with the aim of eventually replacing InP with GaAs as the substrate of choice for communication applications. ...

Choy, Henry Kwong Hin, 1974-

2005-01-01T23:59:59.000Z

392

Room-temperature electric-field controlled spin dynamics in ,,110... InAs quantum wells  

E-Print Network (OSTI)

Room-temperature electric-field controlled spin dynamics in ,,110... InAs quantum wells K. C. Halla pseudomagnetic fields exceeding 1 T when only 140 mV is applied across a single quantum well. Using this large­11 and the influence of the Rashba pseudomagnetic fields on the electron spin relaxation time in GaAs quantum wells

Flatte, Michael E.

393

Pulsed optically detected NMR of single GaAs/AlGaAs quantum wells  

E-Print Network (OSTI)

Pulsed optically detected NMR of single GaAs/AlGaAs quantum wells Marcus Eickhoff* and Dieter Suter, nanometer-sized quantum wells possible with excellent sensitivity and selectivity while avoiding.60.-k; 78.55.Cr; 78.67.De Keywords: ODNMR; Pulsed excitation; Quantum well; GaAs 1. Introduction Nuclear

Suter, Dieter

394

Influence of defect formation as a result of incorporation of a Mn {delta} layer on the photosensitiviy spectrum of InGaAs/GaAs quantum wells  

Science Conference Proceedings (OSTI)

The influence of defect formation upon the deposition of a Mn {delta} layer and a GaAs coating layer (with the use of laser evaporation) on the photosensitivity spectra of heterostructures with InGaAs/GaAs quantum wells located in the near-surface region has been studied.

Gorshkov, A. P., E-mail: gorskovap@phys.unn.ru; Karpovich, I. A.; Pavlova, E. D.; Kalenteva, I. L. [Lobachevsky State University of Nizhny Novgorod (Russian Federation)

2012-02-15T23:59:59.000Z

395

Mesoscopic Magnetic/Semiconductor Heterostructures  

Science Conference Proceedings (OSTI)

We report the experimental results of Fe and Fe3O4 nanostructures on GaAs(100) surfaces and hybrid Ferromagnetic/Semiconductor/Ferromagnetic (FM/SC/FM) spintronic devices. Element specific x-ray magnetic circular dichroism (XMCD) ... Keywords: Epitaxial ferromagnetic thin film, ferromagnetic/semiconductor hybrid structures, spintronics

Yong Bing Xu; E. Ahmad; Yong Xiong Lu; J. S. Claydon; Ya Zhai; G. van der Laan

2006-09-01T23:59:59.000Z

396

A 1-GSPS CMOS Flash A/D Converter for System-on-Chip Applications  

Science Conference Proceedings (OSTI)

Abstract: This paper presents an ultrafast CMOS flash A/D converter design and performance. Although the featured A/D converter is designed in CMOS, the performance is compatible to that of GaAs technology currently available. To achieve high-speed in ...

Jincheol Yoo; Kyusun Choi; Ali Tangel

2001-04-01T23:59:59.000Z

397

Theoretical calculations of the primary defects induced by pions and protons in SiC  

E-Print Network (OSTI)

In the present work, the bulk degradation of SiC in hadron (pion and proton) fields, in the energy range between 100 MeV and 10 GeV, is characterised theoretically by means of the concentration of primary defects per unit fluence. The results are compared to the similar ones corresponding to diamond, silicon and GaAs.

Sorina Lazanu; Ionel Lazanu; Emilio Borchi; Mara Bruzzi

2000-07-06T23:59:59.000Z

398

Optically-initiated silicon carbide high voltage switch  

DOE Patents (OSTI)

An improved photoconductive switch having a SIC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.

Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Sullivan, James S. (Livermore, CA); Sanders, David M. (Livermore, CA)

2012-02-28T23:59:59.000Z

399

All-optical injection and control of spin and electrical currents in quantum wells Ali Najmaie, R. D. R. Bhat, and J. E. Sipe  

E-Print Network (OSTI)

All-optical injection and control of spin and electrical currents in quantum wells Ali Najmaie, R of the injected carriers. This degeneracy is lifted in a quantum well semiconductor structure due to confinement injection of electrical and spin currents in the plane of a GaAs quantum well and its control through

Sipe,J. E.

400

Characterization of MEMS sensor for RF transmitted power measurement  

Science Conference Proceedings (OSTI)

In this report we introduce the procedure for performing a thermo mechanical design and analysis of thermal GaAs-based MEMS devices. It will provide the procedure how thermal analysis should be made and model equations used to describe conduction, convection, ... Keywords: GaAs microsystems, MEMS, power sensor, thermal converter, thermo-mechanical simulations

Jiri Jakovenko; Miroslav Husak

2006-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Regeneration Effect of Fluoride-rich Granular Activated Alumina on Desorption Regent NaOH Solution  

Science Conference Proceedings (OSTI)

As an effective adsorbent, granular activated alumina (GAA) has been widely used in defluoridation. In order to reduce cost and operate environment-friendly, the adsorbent should be regenerated. In this paper, column experiment was done to characterize ... Keywords: adsorption, regeneration, defluoridation, granular activated alumina

Baijie Niu; Wenming Ding; Dan Dang

2012-05-01T23:59:59.000Z

402

Automated Calculation of DIII-D Neutral Beam Availability (A23286)  

E-Print Network (OSTI)

In The Proc. Of The 18th IEEE/NPSS Symp. On Fusion Engineering, Albuquerque, New Mexico (Institute Of Electrical And Electronics Engineers, Inc., Piscataway, 1999) P. 511; And General Atomics Report GA-A23286 (1999)18th IEEE/NPSS Symposium on Fusion Engineering Albuquerque New Mexico, US, 1999985284369

Phillips, J.C.

1999-10-01T23:59:59.000Z

403

Design and Analyses of Transmission Lines for the 110 GHz ECH Upgrade to 6 MW for DIII-D (A23288)  

E-Print Network (OSTI)

In The Proc. Of The 18th IEEE/NPSS Symp. On Fusion Engineering, Albuquerque, New Mexico (Institute Of Electrical And Electronics Engineers, Inc., Piscataway, 1999) P. 499; And General Atomics Report GA-A23288 (1999)18th IEEE/NPSS Symposium on Fusion Engineering Albuquerque New Mexico, US, 1999997291689

Grunloh, H.J.

1999-10-01T23:59:59.000Z

404

Khesbn no. 79-80 - April 1975 - Journal  

E-Print Network (OSTI)

Tybiayaa^nx 80-79 py&na ,aû$anp ny¡o31 pK DnyiairïTa ,w p^dkpa.iya»x vi Bigpga'Da^n px ,anp lyay pa oiyoan yty^aaypvya nya ga^a "T pavT ax^x anp tra pnw ytiPT'» ya^aayaig pa

Admin, LAYCC

1975-01-01T23:59:59.000Z

405

Nanofaceting and alloy decomposition: From basic studies to advanced photonic devices  

Science Conference Proceedings (OSTI)

Most of the modern epitaxial structures for semiconductor lasers serving the needs of optical storage and fiber pumping are grown on misoriented GaAs(001) substrates. It has been found in metal-organic vapor-phase epitaxy that surface misorientation ... Keywords: Alloy decomposition, High resolution, Nanofaceting, Photonic bangap crystal laser, Polarized photoluminescence, Quantum well, Quantum wire, Transmission electron microscopy

V. A. Shchukin; N. N. Ledentsov; I. P. Soshnikov; N. V. Kryzhanovskaya; M. V. Maximov; N. D. Zakharov; P. Werner; D. Bimberg

2006-12-01T23:59:59.000Z

406

Lithography scaling issues associated with III-V MOSFETs  

Science Conference Proceedings (OSTI)

In this work we investigate fabrication issues associated with scaling down the gate length and source drain contact separation of a III-V MOSFET. We used high resolution electron-beam lithography and lift-off for gate and ohmic contact patterning to ... Keywords: E-beam, GaAs, Lift-off, MOSFET, PMMA, Resist thickness variation

O. Ignatova; S. Thoms; W. Jansen; D. S. Macintyre; I. Thayne

2010-05-01T23:59:59.000Z

407

Considerations of Selection of ECH System Transmission Line Waveguide Diameter for ITER (A25121)  

E-Print Network (OSTI)

Proc. 3rd Tech. Mtg On Electron Cyclotron Resonanxe Heating Physics And Technology For ITER, Como, Italy, 2005; General Atomics Report GA-A25121 (2005)3rd Technical Meeting on Electron Cyclotron Resonance Heating Physics and Technology for ITER Como, IT, 2005999610860

Olstad, R.A.

2005-07-07T23:59:59.000Z

408

Progress on Corrugated Waveguide Components Suitable for ITER ECH and Current Drive Transmission Lines (A27322)  

E-Print Network (OSTI)

Proc. Of 17th Electron Cyclotron Emission And Electron Cyclotron Resonance Heating, Deurne, The Netherlands, 2012; General Atomics Report GA-A27322 (2012)17th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating Deurne, NL, 2012999619079

Olstad, R.A.

2012-05-09T23:59:59.000Z

409

The Molecular Foundry User Proposal Form Proposal: MELOSH_05-04-2009_16-09-29  

E-Print Network (OSTI)

If other, then specify: Global Climate and Energy Project Affiliation Street Address: McCullough BuildingN and GaAs have been shown to exhibit very high quantum efficiencies with an appropriate surface coating.C.) If other, then specify: Affiliation Street Address: McCullough Building, Room 434, 476 Lomita Mall

Lee, Jason R.

410

Profiling the Built-in Electrical Potential in III-V Multijunction Solar Cells: Preprint  

DOE Green Energy (OSTI)

We report on a direct measurement of the electrical potential on cross-sections of GaInP2/GaAs multiple-junction solar cells by using an ultrahigh-vacuum scanning Kelvin probe microscope (UHV-SKPM). The UHV-SKPM allows us to measure the potential without air molecules being adsorbed on the cross-sectional surface. Moreover, it uses a GaAs laser with photon energy of 1.4 eV for the atomic force microscope (AFM) operation. This eliminated the light-absorption-induced bottom-junction flattening and top-junction enhancement, which happened in our previous potential measurement using a 1.85-eV laser for the AFM operation. Three potentials were measured at the top, tunneling, and bottom junctions. Values of the potentials are smaller than the potentials in the bulk. This indicates that the Fermi level on the UHV-cleaved (110) surface was pinned, presumably due to defects upon cleaving. We also observed higher potentials at atomic steps than on the terraces for both GaInP2 epitaxial layer and GaAs substrate. Combining scanning tunneling microscopy (STM) and SKPM measurements, we found that the potential height at steps of the GaAs substrate depends on the step direction, which is probably a direct result of unbalanced cations and anions at the steps.

Jiang, C.-S.; Friedman, D. J.; Moutinho, H. R.; Al-Jassim, M. M.

2006-05-01T23:59:59.000Z

411

Electron Subband Population and Mobility in Asymmetric Coupled Quantum Wells  

Science Conference Proceedings (OSTI)

The electron subband energy and population engineering by inserting a thin AlGaAs barrier inside a GaAs quantum well (QW) is considered. The specific voltage across the coupled QW's which arises due to the asymmetric deformation of electron wave function ... Keywords: electron-phonon scattering in a quantum well, photovoltaic effect

Juras Pozela; Karolis Pozela; Vida Juciene And Audrius Namajunas

1998-03-01T23:59:59.000Z

412

Energy Multiplier Module (EM^2) Using Innovation for Optimizing Small Reactor Capabilities (A27149)  

E-Print Network (OSTI)

Proc. Of IAEA Tech. Com. Mtg On Fuel And Fuel Cycle Options For Small And Medium Size Reactors, Vienna, Austria, 2011; General Atomics Report GA-A27149 (2011)IAEA Technical Committee Meeting on Fuel and Fuel Cycle Options for Small and Medium Size Reactors Vienna, AT, 2011999619070

Bertch, T.C.

2011-10-06T23:59:59.000Z

413

Selective Formation of Size-Controlled Silicon Nanocrystals by Photosynthesis in SiO Nanoparticle Thin Film  

Science Conference Proceedings (OSTI)

The SiOx thin film with a thickness of about 1 mum was formed on a GaAs substrate by bar-coating with the organic solution of the SiOx nanoparticles (~40 nm). The as-formed SiOx thin film consists of the SiOx ... Keywords: ${hbox{SiO}}_{x}$ , Nanocrystal, Raman, photosynthesis, self- limiting, silicon

Changyong Chen; S. Kimura; S. Nozaki; H. Ono; K. Uchida

2006-11-01T23:59:59.000Z

414

Optical and Quantum Electronics 27 (1995) 421-425 Precise nonselective chemically assisted  

E-Print Network (OSTI)

current density as low as 380Acm-2 with output power >11 mW are fabricated. Spatial uniformity is 5% overGaAs half-air-post VCSELs. Methods for analysing interference data for bulk GaAs and DBRs are also estab+ ion energy and the beam current density at sample are Acm -2, respectively

Lee, Yong-Hee

415

Bonding and gap states at GaAs-oxide interfaces  

Science Conference Proceedings (OSTI)

The nature of bonding and possible causes of Fermi level pinning at high mobility-high dielectric constant oxide GaAs:HfO"2 interfaces are discussed. It is argued that these are atoms with defective bonding, rather than states due to the bulk semiconductor ... Keywords: GaAs, bonding, interface

John Robertson; Liang Lin

2011-04-01T23:59:59.000Z

416

In situ atomic layer deposition and synchrotron-radiation photoemission study of Al2O3 on pristine n-GaAs(0 0 1)-4×6 surface  

Science Conference Proceedings (OSTI)

This work presents the in situ reflection high-energy electron diffraction (RHEED), scanning tunneling microscopy (STM) and synchrotron-radiation photoemission studies for the morphological and interfacial chemical characterization of in situ atomic ... Keywords: Atomic layer deposition, GaAs, Molecular beam epitaxy, Synchrotron-radiation photoemission

Y. H. Chang; M. L. Huang; P. Chang; J. Y. Shen; B. R. Chen; C. L. Hsu; T. W. Pi; M. Hong; J. Kwo

2011-07-01T23:59:59.000Z

417

Molecular beam epitaxy passivation studies of Ge and III-V semiconductors for advanced CMOS  

Science Conference Proceedings (OSTI)

Future CMOS technologies will require the use of substrate material with a very high mobility in order to fulfil the performance requirements. Therefore, combination of Ge p-MOS with n-MOS devices made out of high mobility III/V compounds, such as GaAs, ... Keywords: High mobility semiconductors, Molecular beam epitaxy (MBE), Passivation

C. Merckling; J. Penaud; D. Kohen; F. Bellenger; A. Alian; G. Brammertz; M. El-Kazzi; M. Houssa; J. Dekoster; M. Caymax; M. Meuris; M. M. Heyns

2009-07-01T23:59:59.000Z

418

Compound semiconductor MOSFETs  

Science Conference Proceedings (OSTI)

Enhancement mode, high electron mobility MOSFET devices have been fabricated using an oxide high-@k gate dielectric stack developed using molecular beam epitaxy. A template layer of Ga"2O"3, initially deposited on the surface of the III-V device unpins ... Keywords: Compound semiconductors, GaAs gate dielectric, III-V MOSFETs

R. Droopad; K. Rajagopalan; J. Abrokwah; P. Zurcher; M. Passlack

2007-09-01T23:59:59.000Z

419

The new -NMR facility at TRIUMF and applications in semiconductors  

E-Print Network (OSTI)

The new -NMR facility at TRIUMF and applications in semiconductors K.H. Chow a, Z. Salman b R facililty for conducting beta-detected nuclear magnetic resonance (-NMR) investigations of condensed matter facility are described, and some preliminary results on 8Li+ in GaAs are presented. Key words: -NMR

Baartman, Richard Abram

420

Friday Morning Sessions (June 28) - TMS  

Science Conference Proceedings (OSTI)

In spite of the fact that both bulk GaAs and GaN have rather large band gaps (1.5 and 3.2 eV respectively), we find a significant narrowing of the bandgap in the ...

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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

Optically initiated silicon carbide high voltage switch  

DOE Patents (OSTI)

An improved photoconductive switch having a SiC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.

Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Sullivan, James S. (Livermore, CA); Sanders; David M. (Livermore, CA)

2011-02-22T23:59:59.000Z

422

Performance, Diagnostics, Controls and Plans for the Gyrotron System on the DIII-D Tokamak (A27312)  

E-Print Network (OSTI)

Proc. Of 17th Electron Cyclotron Emission And Electron Cyclotron Resonance Heating, Deurne, The Netherlands, 2012; General Atomics Report GA-A27312 (2012)17th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating Deurne, NL, 2012999619078

Lohr, J.

2012-05-09T23:59:59.000Z

423

Real-Time Data Acquisition and Feedback Control Using Linux Intel Computers (A25101)  

E-Print Network (OSTI)

Proc. 5th IAEA Tech. Mtg On Control, Data Acquisition, And Remote Participation For Fusion Research, Budapest, Hungary, 2005; General Atomics Report GA-A25101 (2005)5th IAEA Technical Committee Meeting on Control, Data Acquisition and Remote Participation for Fusion Research Budapest, HU, 2005999610870

Penaflor, B.G.

2005-07-25T23:59:59.000Z

424

COBRA: Determining Atomic Positions in Thin-Film Structures and Interfaces  

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

COBRA: Determining Atomic Positions in Thin-Film Structures and Interfaces COBRA: Determining Atomic Positions in Thin-Film Structures and Interfaces Coherent Bragg rod analyses (COBRA) experiments using synchrotron x-rays at Argonne's Advanced Photon Source (MHATT-CAT and PNC-CAT beamlines) directly revealed the sub-angstrom atomic interaction of epitaxial films with substrates. Information on how atoms in the adjoining layers of the film and substrate rearrange to mimic each other may lead to improvements in semiconductor manufacturing and the development of novel heterostructure materials, such as multilayer ferroelectrics, magnetic nanostructures and thin film superconductors. COBRA electron density map of a Gd2O3 film on a gallium arsenide substrate. The peaks correspond to folded Gd atomic positions parallel to the plane of the substrate.

425

CX-005363: Categorical Exclusion Determination | Department of Energy  

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

5363: Categorical Exclusion Determination 5363: Categorical Exclusion Determination CX-005363: Categorical Exclusion Determination Solar Junction's 100 Megawatt Manufacturing Line CX(s) Applied: B1.31 Date: 03/04/2011 Location(s): San Jose, California Office(s): Loan Guarantee Program Office The Department of Energy's proposed action is to issue a loan guarantee to Solar Junction to finance a 100 megawatt (MW) solar cell manufacturing line for multifunction photovoltaic solar cells to expand their existing 7 MW Demonstration Facility at 401 Charcot Avenue, San Jose, California 95131. The proposed project will commercialize an entirely new class of high-efficiency solar cells and concentrating photovoltaic components that incorporate high performance junctions formed with a tunable band gap semiconductor material, Gallium Indium Nitride Arsenide.

426

Electron-doping  

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

Electron-doping Electron-doping evolution of the low-energy spin excitations in the iron arsenide superconductor BaFe 2-x Ni x As 2 Miaoyin Wang, 1 Huiqian Luo, 2 Jun Zhao, 1 Chenglin Zhang, 1 Meng Wang, 2,1 Karol Marty, 3 Songxue Chi, 4 Jeffrey W. Lynn, 4 Astrid Schneidewind, 5,6 Shiliang Li, 2, * and Pengcheng Dai 1,2,3,† 1 Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA 2 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190, China 3 Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA 4 NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA 5 Gemeinsame Forschergruppe HZB, Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109

427

2010-0124-NScD-Dai-SC in chalcoginide[2][1]  

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

Fig. 1. Magnetic structure Fig. 1. Magnetic structure of the (a) iron chalco- genide, and (b) iron pnic- tide systems, showing exchange couplings of the Heisenburg Hamiltonian. SNS shows novel spin waves in iron chalcogenide Fe 1.05 Te Measurements conducted at the Spallation Neutron Source at ORNL have determined exchange couplings in the mag- netically ordered chalcogenide Fe1.05Te, a nonsuperconducting member of the iron-based family of superconductors. The results show the exchange pairings thought to be related to superconductivity occur in a next-nearest-neighbor ordering of atoms, rather than in nearest-neighbor order as in a previously studied iron arsenide. Researchers from the University of Tennessee, ORNL, and other institutions collaborated to study the spin waves in Fe

428

TVDG LET Calculator  

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

To The B N L Tandem Van de Graaff Accelerator To The B N L Tandem Van de Graaff Accelerator TVDG LET Calculator This program calculates the Peak LET, Corresponding Energy and Range as well as the LET and Range at the Specified Energy for the Specified Ion in the Specified Target. Select the Target Material from the dropdown list. Select the Ion Specie from the dropdown list. Enter the Total Ion Energy in the text box. This is equal to the Atomic Mass times the Energy/Nucleon. Click the 'Calculate' button or press the 'Enter' key. The Peak LET, Corresponding Energy and Range as well as the LET and Range at the Specified Energy for the Specified Ion in the Specified Target will be returned. Select your Target from the list Air Aluminum Oxide Carbon Copper Gallium Arsenide Gold Polyester Polyethylene Silicon Silicon Dioxide Skin Soda Lime Glass Sodium Iodide Water Select your Ion from the list

429

Definition: Semiconductor | Open Energy Information  

Open Energy Info (EERE)

Semiconductor Semiconductor Jump to: navigation, search Dictionary.png Semiconductor Any material that has a limited capacity for conducting an electric current. Certain semiconductors, including silicon, gallium arsenide, copper indium diselenide, and cadmium telluride, are uniquely suited to the photovoltaic conversion process.[1] View on Wikipedia Wikipedia Definition A semiconductor is a material which has electrical conductivity to a degree between that of a metal (such as copper) and that of an insulator (such as glass). Semiconductors are the foundation of modern solid state electronics, including transistors, solar cells, light-emitting diodes (LEDs), quantum dots and digital and analog integrated circuits. A semiconductor may have a number of unique properties, one of which is the

430

NREL: News - NREL Reports 31.1% Efficiency for III-V Solar Cell  

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

913 913 NREL Reports 31.1% Efficiency for III-V Solar Cell Conversion-efficiency mark is a world record for a two-junction solar cell measured under one-sun illumination June 24, 2013 The Energy Department's National Renewable Energy Lab has announced a world record of 31.1% conversion efficiency for a two-junction solar cell under one sun of illumination. NREL Scientist Myles Steiner announced the new record June 19 at the 39th IEEE Photovoltaic Specialists Conference in Tampa, Fla. The previous record of 30.8% efficiency was held by Alta Devices. The tandem cell was made of a gallium indium phosphide cell atop a gallium arsenide cell, has an area of about 0.25 square centimeters and was measured under the AM1.5 global spectrum at 1,000 W/m2. It was grown inverted, similar to the NREL-developed inverted metamorphic multi-junction

431

NREL photovoltaic subcontract reports: Abstracts and document control information, 1 August 1991--31 July 1992  

DOE Green Energy (OSTI)

This report contains document control information and abstracts for the National Renewable Energy Laboratory (NREL) subcontracted photovoltaic program publications. It also lists source information on additional publications that describe US Department of Energy (DOE) PV research activities. It is not totally exhaustive, so it lists NREL contacts for requesting further information on the DOE and NREL PV programs. This report covers the period from August 1, 1991, through July 31, 1992. The purpose of continuing this type of publication is to help people keep abreast of specific PV interests, while maintaining a balance on the costs to the PV program. The information in this report is organized under PV technology areas: Amorphous silicon research; polycrystalline thin films (including copper indium diselenide, cadmium telluride, and thin-film silicon); crystalline materials and advanced concepts (including silicon, gallium arsenide, and other group III-V materials); and PV manufacturing technology development (which may include manufacturing information for various types of PV materials).

Not Available

1992-08-01T23:59:59.000Z

432

Polymer photovoltaic cells: enhanced efficiencies via a network of internal donor–acceptor heterojunctions  

E-Print Network (OSTI)

The carrier collection efficiency (?c) and energy conversion efficiency (?e) of polymer photovoltaic cells were improved by blending of the semiconducting polymer with C60 or its functionalized derivatives. Composite films of poly(2-methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) and fullerenes exhibit ?c of about 29 percent of electrons per photon and ?e of about 2.9 percent, efficiencies that are better by more than two orders of magnitude than those that have been achieved with devices made with pure MEH-PPV. The efficient charge separation results from photoinduced electron transfer from the MEH-PPV (as donor) to C60 (as acceptor); the high collection efficiency results from a bicontinuous network of internal donor-acceptor heterojunctions. The need to develop inexpensive renewable energy sources continues to stimulate new approaches to production of efficient, lowcost photovoltaic devices. Although inorganic semiconductors (silicon, amorphous silicon, gallium arsenide, and sulfide

G. Yu; J. Gao; J. C. Hummelen; F. Wudl; A. J. Heeger

1995-01-01T23:59:59.000Z

433

Regenerative mode photo electrochemical cells in molten salt electrolytes. 1st four monthly report (1/31/80)  

DOE Green Energy (OSTI)

The most promising photoelectrodes selected for use in the butyl pyridinium chloride-aluminum chloride room temperature molten salt are n-type silicon, gallium arsenide and cadmium telluride. The solubilities of these semiconductors are low, and their conduction and valence band edges are favorably located. Cadmium selenide and sulfide showed significant solubility in the melt, and the conduction band edge for p-type cadmium telluride was too close to the aluminum deposition potential. Several reversible redox couples have been identified, which could potentially be used in a photoelectrochemical cell. These include W/sup 5 +//W/sup 6 +/ and Eu/sup 2 +//Eu/sup 3 +/ as well as ferrocene and its derivatives.

Not Available

1980-01-01T23:59:59.000Z

434

Rosenkranz-082511 - Argonne National Laboratories, Materials Sicence  

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

Rosenkranz-082511 Rosenkranz-082511 MATERIALS SCIENCE COLLOQUIUM SPEAKER: Dr. Stephan Rosenkranz Materials Science Division Argonne National Laboratory TITLE: "Resonant spin excitations in Iron Arsenide superconductors" DATE: Thursday, August 25, 2011 TIME: 11:00 a.m. PLACE: Building 212 / A-157 HOST: Anand Bhattacharya Refreshments will be served at 10:45 a.m. ABSTRACT: The iron pnictides have attracted great interest following the discovery of superconductivity up to 50K and because of their superficial similarities with the cuprate superconductors. In both systems, superconductivity emerges when longrange antiferromagnetic order is suppressed by doping or pressure. This indicates that spin correlations are intimately connected with superconductivity and may be involved in the

435

The Story of a Cutting-Edge Solar Startup | Department of Energy  

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

The Story of a Cutting-Edge Solar Startup The Story of a Cutting-Edge Solar Startup The Story of a Cutting-Edge Solar Startup June 20, 2012 - 9:40am Addthis Erin R. Pierce Erin R. Pierce Digital Communications Specialist, Office of Public Affairs What does this project do? Watch the video to learn how Alta Devices manufacturers high performance solar cells at a low cost. Alta Devices is rethinking how high performance solar cells are made. The Silicon Valley startup has taken gallium arsenide -- an expensive semiconductor material that is incredibly efficient at turning sunlight into electricity -- and developed a commercially viable processes for manufacturing it into solar modules. In 2009, Alta Devices was selected to participate in the Energy Department's SunShot Incubator program. Now in its sixth iteration,

436

Analysis of photovoltaic/thermal electric power plant systems  

DOE Green Energy (OSTI)

A conceptual definition and performance evaluation of a 100 megawatt (MW) hybrid photovoltaic/thermal electric power plant has been carried out. The concept utilizes the ability of gallium arsenide photovoltaic cells to achieve high conversion efficiency at high incident fluxes and elevated temperatures. Solar energy is focused by a field of steerable mirrors (heliostats) onto a tower mounted receiver whose outer surface is covered with gallium arsenide (AlGaAs/GaAs) solar cells and whose inner surface is a water boiler. The solar cells convert a fraction of the incident radiation into electrical energy, and the remaining energy is extracted at approximately 200/sup 0/C and used to power a Rankine cycle turbine generator (bottoming cycle). Water is used as the solar cell array coolant, as the thermodynamic working fluid, and as the thermal energy storage medium. Parametric studies were conducted to select conceptual design parameters and operational characteristics which imply the lowest levelized busbar electric energy costs. Parameters varied were collector area, condenser surface area, fan power, ambient temperature, and electric and thermal energy storage capacities. The report describes the concept, outlines the design analysis method, summarizes the parametric study results, and defines the selected plant configuration. The lowest levelized busbar electric energy generation cost, 70 mills/kilowatt-hr., was achieved with a relatively small collector area, 0.8 x 10/sup 6/ square meters, and no stored energy. A rough comparison of this combined power plant with a similar photovoltaic plant, operated at lower solar cell temperature and with no bottoming cycle, showed the busbar cost of electricity (BBEC) from the combined system to be approximately 9% lower.

Gluck, D.F.; Kelley, W.A.

1979-03-01T23:59:59.000Z

437

Products of an Artificially Induced Hydrothermal System at Yucca Mountain  

DOE Green Energy (OSTI)

Studies of mineral deposition in the recent geologic past at Yucca Mountain, Nevada, address competing hypotheses of hydrothermal alteration and deposition from percolating groundwater. The secondary minerals being studied are calcite-opal deposits in fractures and lithophysal cavities of ash-flow tuffs exposed in the Exploratory Studies Facility (ESF), a 7.7-km tunnel excavated by the Yucca Mountain Site Characterization Project within Yucca Mountain. An underground field test in the ESF provided information about the minerals deposited by a short-lived artificial hydrothermal system and an opportunity for comparison of test products with the natural secondary minerals. The heating phase lasted nine months, followed by a nine-month cooling period. Natural pore fluids were the only source of water during the thermal test. Condensation and reflux of water driven away from the heater produced fluid flow in certain fractures and intersecting boreholes. The mineralogic products of the thermal test are calcite-gypsum aggregates of less than 4-micrometer crystals and amorphous silica as glassy scale less than 0.2 mm thick and as mounds of tubules with diameters less than 0.7 micrometers. The minute crystal sizes of calcite and gypsum from the field test are very different from the predominantly coarser calcite crystals (up to cm scale) in natural secondary-mineral deposits at the site. The complex micrometer-scale textures of the amorphous silica differ from the simple forms of opal spherules and coatings in the natural deposits, even though some natural spherules are as small as 1 micrometer. These differences suggest that the natural minerals, especially if they were of hydrothermal origin, may have developed coarser or simpler forms during subsequent episodes of dissolution and redeposition. The presence of gypsum among the test products and its absence from the natural secondary-mineral assemblage may indicate a higher degree of evaporation during the test than during the deposition of natural calcite-opal deposits.

S. Levy

2000-08-07T23:59:59.000Z

438

Oil-Well Cement and C3S Hydration Under High Pressure as Seen by In Situ X-Ray Diffraction, Temperatures ;= 80 degrees C with No Additives  

SciTech Connect

The hydration kinetics of a white cement and batches of both Class G and H oil-well cements were examined between 0 and 60 MPa, at {le}80 C, using in situ synchrotron X-ray diffraction. This gives a continuous measure of the C{sub 3}S (Ca{sub 3}SiO{sub 5}), CH (Ca(OH){sub 2}), C{sub 4}AF (Ca{sub 2}FeAlO{sub 5}), ettringite, and other phases in the hydrating slurries. Slurries prepared from single-phase C{sub 3}S; synthetic C{sub 4}AF, and gypsum; and white cement, synthetic C{sub 4}AF and gypsum were also examined. An increasing pressure enhanced the rate of hydration for all slurries. Analysis of the data, using a kinetic model, provided rate constants that were used to obtain activation volumes for C{sub 3}S hydration. For all the cement and C{sub 3}S slurries studied, similar activation volumes were obtained (average {Delta}V{double_dagger}{sup -}-35 cm{sup 3}/mol), indicating that the presence of cement phases other than C{sub 3}S has a modest influence on the pressure dependence of C{sub 3}S hydration. An alternative analysis, using the time at which 90% of the initial C{sub 3}S remained, gave similar activation volumes. Pressure accelerated the formation of ettringite from synthetic C{sub 4}AF in the presence of gypsum. However, in slurries containing cement, the pressure dependence of C{sub 3}S hydration plays a major role in determining the pressure dependence of ettringite formation.

Jupe, Andrew C.; Wilkinson, Angus P.; Funkhouser, Garry P. (Halliburton); (GIT)

2012-06-28T23:59:59.000Z

439

Origin, distribution, and movement of brine in the Permian Basin (U. S. A. ). A model for displacement of connate brine  

SciTech Connect

Na-Cl, halite Ca-Cl, and gypsum Ca-Cl brines with salinities from 45 to >300 g/L are identified and mapped in four hydrostratigraphic units in the Permian Basin area beneath western Texas and Oklahoma and eastern New Mexico, providing spatial and lithologic constraints on the interpretation of the origin and movement of brine. Na-Cl brine is derived from meteoric water as young as 5-10 Ma that dissolved anhydrite and halite, whereas Ca-Cl brine is interpreted to be ancient, modified-connate Permian brine that now is mixing with, and being displaced by, the Na-Cl brine. Displacement fronts appear as broad mixing zones with no significant salinity gradients. Evolution of Ca-Cl brine composition from ideal evaporated sea water is attributed to dolomitization and syndepositional recycling of halite and bittern salts by intermittent influx of fresh water and sea water. Halite Ca-Cl brine in the evaporite section in the northern part of the basin differs from gypsum Ca-Cl brine in the south-central part in salinity and Na/Cl ratio and reflects segregation between halite- and gypsum-precipitating lagoons during the Permian. Ca-Cl brine moved downward through the evaporite section into the underlying Lower Permian and Pennsylvanian marine section that is now the deep-basin brine aquifer, mixing there with pre-existing sea water. Buoyancy-driven convection of brine dominated local flow for most of basin history, with regional advection governed by topographically related forces dominant only for the past 5 to 10 Ma. 71 refs., 11 figs.

Bein, A.; Dutton, A.R. (Univ. of Texas, Austin (United States))

1993-06-01T23:59:59.000Z

440

Longer-term Characterization of Mercury Partitioning and Re-emissions in a Full-scale Wet Flue Gas Desulfurization System, Site 2  

Science Conference Proceedings (OSTI)

This document presents and discusses results from an EPRI project focused on understanding and enhancing how mercury is captured by a wet flue gas desulfurization (FGD) system and how it partitions among the FGD liquor, fine solids, and bulk FGD solid byproduct. A second objective was to close a mercury balance around the host unit by determining what portion of the coal mercury exits the stack with the scrubbed flue gas and how much ends up in the fly ash, byproduct gypsum, and FGD wastewater. During t...

2010-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


441

Interimadvies inzake de mogelijke consequenties voor de nederlandse bevolking van het toepassen van afvalstoffen met een verhoogd gehalte aan radionucliden als bouwmateriaal (interim recommendation regarding the eventual consequences for the people of the Netherlands resulting from the use of waste products with an increased radionuclide content as construction materials)  

Science Conference Proceedings (OSTI)

The report discusses the potential radiological consequences for the population of the Netherlands of using waste materials as building materials in housing construction. There is a growing need to use various waste products as building materials. Some of these substances, such as flyash and waste gypsum (in this case phosphogypsum), contain higher concentrations of radioactivity than the usual building materials. Unless these waste substances are re-used in some form or other, they will be direct dumped or discharged. A recommendation on an upper limit for the permissible level of radionuclides in building materials is urgently needed.

Not Available

1985-02-12T23:59:59.000Z

442

Mercury in FGD Byproducts  

Science Conference Proceedings (OSTI)

This report provides interim results from two EPRI co-funded projects that pertain to what happens to mercury in flue gas from coal-fired power boilers when the scrubbed by wet flue gas desulfurization (FGD) systems. The first project is co-sponsored by the U.S. Department of Energy's National Energy Technology Laboratory (NETL) and by USG Corporation under Cooperative Agreement DE-FC26-04NT42080, "Fate of Mercury in Synthetic Gypsum Used for Wallboard Production." The second project is being co-sponsore...

2005-12-07T23:59:59.000Z

443

Spin-polarized ballistic transport channel in a thin superlattice composed of zincblende half-metallic compounds  

SciTech Connect

The authors examine theoretically conduction processes near the Fermi energy of thin layers of zincblende structure half metals, using as an example a superlattice consisting of monolayers of GaAs and MnAs, a bilayer of CrAs, and a bilayer of GaAs. By artificially separating bilayers, they show that non-fourfold coordinated Cr states thwart half metallicity. However, capping the metal-As bilayers restores half metallicity and ballistic conduction of electrons around 0.3 eV above the Fermi level will give nearly 100% spin-polarized transmission in the direction of the thin superlattice. Recent developments suggest atomic layer epitaxy can be used to produce such thin layers for spintronics applications.

Qian, M C; Fong, C Y; Pickett, W E; Yang, L H; Pask, J E; Dag, S

2004-05-11T23:59:59.000Z

444

Beyond the Transistor | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Beyond the Transistor Beyond the Transistor Discovery & Innovation Stories of Discovery & Innovation Brief Science Highlights SBIR/STTR Highlights Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 10.12.11 Beyond the Transistor EFRC researchers fabricate a novel device for channeling light. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo Schematic of a GaAs 3D photonic crystal Image courtesy of the University of Illinois at Urbana-Champaign Schematic of a GaAs 3D photonic crystal (blue) containing an InGaAs light-emitting layer (red). The structure is lithographically patterned into the form of a cylindrical mesa with a ring electrode on the top surface (gold).

445

Electronic  

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

contribution contribution to friction on GaAs: An atomic force microscope study Yabing Qi, 1,2 J. Y. Park, 2 B. L. M. Hendriksen, 2 D. F. Ogletree, 2 and M. Salmeron 2,3 1 Applied Science and Technology Graduate Group, University of California, Berkeley, California 94720, USA 2 Materials Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA 3 Department of Materials Sciences and Engineering, University of California, Berkeley, California 94720, USA ͑Received 23 January 2008; revised manuscript received 11 April 2008; published 7 May 2008͒ The electronic contribution to friction at semiconductor surfaces was investigated by using a Pt-coated tip with 50 nm radius in an atomic force microscope sliding against an n-type GaAs͑100͒ substrate. The GaAs surface was covered by an approximately 1 nm thick oxide layer. Charge accumulation

446

Self-organized lattice of ordered quantum dot molecules  

SciTech Connect

Ordered groups of InAs quantum dots (QDs), lateral QD molecules, are created by self-organized anisotropic strain engineering of a (In,Ga)As/GaAs superlattice (SL) template on GaAs (311)B in molecular-beam epitaxy. During stacking, the SL template self-organizes into a two-dimensionally ordered strain modulated network on a mesoscopic length scale. InAs QDs preferentially grow on top of the nodes of the network due to local strain recognition. The QDs form a lattice of separated groups of closely spaced ordered QDs whose number can be controlled by the GaAs separation layer thickness on top of the SL template. The QD groups exhibit excellent optical properties up to room temperature.

Lippen, T. von; Noetzel, R.; Hamhuis, G.J.; Wolter, J.H. [eiTT/COBRA Inter-University Research Institute, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)

2004-07-05T23:59:59.000Z

447

Formation mechanisms of spatially-directed zincblende gallium nitride nanocrystals  

Science Conference Proceedings (OSTI)

We report on the spatially selective formation of GaN nanocrystals embedded in GaAs. Broad-area N{sup +} implantation followed by rapid thermal annealing leads to the formation of nanocrystals at the depth of maximum ion damage. With additional irradiation using a Ga{sup +} focused ion beam, selective lateral positioning of the nanocrystals within the GaAs matrix is observed in isolated regions of increased vacancy concentration. Following rapid thermal annealing, the formation of zincblende GaN is observed in the regions of highest vacancy concentration. The nucleation of zincblende nanocrystals over the wurtzite phase of bulk GaN is consistent with the predictions of a thermodynamic model for the nanoscale size-dependence of GaN nucleation.

Wood, A. W. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Collino, R. R. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Cardozo, B. L. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Naab, F. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Wang, Y. Q. [Materials Science and Technology Division, Los Alamos National Lab, Los Alamos, New Mexico 87545 (United States); Goldman, R. S. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2011-12-15T23:59:59.000Z

448

CEBAF 200 kV Inverted Electron Gun  

Science Conference Proceedings (OSTI)

Two DC high voltage GaAs photoguns have been built at Jefferson Lab based on a compact inverted insulator design. One photogun provides the polarized electron beam at CEBAF and operates at 130 kV bias voltage. The other gun is used for high average current lifetime studies at a dedicated test facility and has been operated at bias voltage up to 225 kV. The advantages of higher DC voltage for CEBAF include reduced space-charge emittance growth and the potential for prolonged photocathode lifetime. However, a consequence of operating at higher voltages is the increased likelihood of field emission or breakdown, both of which are unacceptable. Highlights of the R&D studies leading toward a production 200keV GaAs photogun for CEBAF will be presented.

J.M. Grames, P.A. Adderley, J. Clark, J. Hansknecht, M. Poelker, M.L. Stutzman, R. Suleiman, K.E.L. Surles-Law

2011-03-01T23:59:59.000Z

449

Electron Traps Detected in p-type GaAsN Using Deep Level Transient Spectroscopy  

DOE Green Energy (OSTI)

The GaAsN alloy can have a band gap as small as 1.0 eV when the nitrogen composition is about 2%. Indium can also be added to the alloy to increase lattice matching to GaAs and Ge. These properties are advantageous for developing a highly-efficient, multi-junction solar cell. However, poor GaAsN cell properties, such as low open-circuit voltage, have led to inadequate performance. Deep-level transient spectroscopy of p-type GaAsN has identified an electron trap having an activation energy near 0.2 eV and a trap density of at least 1016 cm-3. This trap level appears with the addition of small amounts of nitrogen to GaAs, which also corresponds to an increased drop in open-circuit voltage.

Johnston, S.; Kurtz, S.; Friedman, D.; Ptak, A.; Ahrenkiel, R.; Crandall, R.

2005-01-01T23:59:59.000Z

450

Growth of BGaAs by Molecular-Beam Epitaxy and the Effects of a Bismuth Surfactant  

DOE Green Energy (OSTI)

Boron is potentially useful for strain balancing compressively strained materials such as InGaAs and GaAsBi that are being developed for use in optical and electronic devices. Understanding and improving the incorporation of boron in GaAs is an important first step toward the realization of these strain-balanced systems. Here, we show that the apparent boron incorporation in GaAs, determined from X-ray diffraction measurements, decreases as the substrate temperature is increased, although measurements of the metallurgical concentration of boron remain constant. This implies that boron is incorporating preferentially on non-substitutional sites as growth temperature is increased. The addition of a bismuth surfactant flux not only makes the epilayers smoother, but within a narrow range of substrate temperatures, restores the incorporation of substitutional boron.

Ptak, A. J.; Beaton, D. A.; Mascarenhas, A.

2012-07-15T23:59:59.000Z

451

Method of manufacturing flexible metallic photonic band gap structures, and structures resulting therefrom  

DOE Patents (OSTI)

A method of manufacturing a flexible metallic photonic band gap structure operable in the infrared region, comprises the steps of spinning on a first layer of dielectric on a GaAs substrate, imidizing this first layer of dielectric, forming a first metal pattern on this first layer of dielectric, spinning on and imidizing a second layer of dielectric, and then removing the GaAs substrate. This method results in a flexible metallic photonic band gap structure operable with various filter characteristics in the infrared region. This method may be used to construct multi-layer flexible metallic photonic band gap structures. Metal grid defects and dielectric separation layer thicknesses are adjusted to control filter parameters.

Gupta, Sandhya (Bloomington, MN); Tuttle, Gary L. (Ames, IA); Sigalas, Mihail (Ames, IA); McCalmont, Jonathan S. (Ames, IA); Ho, Kai-Ming (Ames, IA)

2001-08-14T23:59:59.000Z

452

Daylighting techniques used in indigenous buildings in the United Arab Emirates (UAE), an investigative approach  

E-Print Network (OSTI)

This study investigated the potential of the daylighting systems used in the indigenous architecture of the United Arab Emirates (UAE), located in Dubai (latitude 25° N longitude 55° E). The analysis tested the lighting performance of three daylighting systems under UAE climatic conditions. The purpose of this research was to investigate the daylighting performance of three of the most common daylighting systems found in the indigenous buildings of the UAE, traditional windows (Dreeshah), gypsum decorative panels and wind tower (Barjeel). The lighting performance of each of the three lighting systems was examined. The lighting performance parameters examined were illuminance level, light distribution, uniformity, and glare. IESNA standards, CIBSE guidelines and LEED 2.2 daylighting credit and recommendations were used as the minimum recommended level for all analyzed variables. On-site measurements (illuminance and luminance) were conducted to compare measured versus simulated measurements inside the space. Desktop Radiance 2.0 Beta was used as the lighting performance analysis tool under clear sky conditions. Results have shown that the gypsum decorative panel performs better than the other two systems in terms of light uniformity and distribution, regardless of a lower illuminance level. The double panel window prototype has poor lighting performance in terms of glare, light distribution and uniformity. Wind tower performed well under the area of the wind tower itself. Apart from that it also had a poor lighting performance in terms of glare, light distribution, and uniformity.

Alnuaimi, Maitha Mohammed

2007-08-01T23:59:59.000Z

453

Immobilization of heavy metals by calcium sulfoaluminate cement  

Science Conference Proceedings (OSTI)

Two types of calcium sulfoaluminate cement containing 20% and 30% phosphogypsum, respectively, were investigated for their ability in hazardous waste stabilization. Fourteen series of pastes were prepared, each containing the following soluble salt: Na{sub 2}CrO{sub 4}.4H{sub 2}O; Na{sub 2}Cr{sub 2}O{sub 7}.2H{sub 2}O; CrCl{sub 3}.6H{sub 2}O; Pb(NO{sub 3}){sub 2}; Zn(NO{sub 3}){sub 2}.6H{sub 2}O; ZnSO{sub 4}.7H{sub 2}O; and CdCl{sub 2}.5H2O. The level of pollution was 0.069 mol of heavy metal per Kg of cement. The study has been carried out by means of X-ray diffraction, thermal analysis, scanning electron microscopy, mercury intrusion porosimetry, electrical conductivity, and leaching tests. Very good retention of lead, cadmium, zinc and trivalent chromium is observed. The retention of hexavalent chromium depends upon the nature of the binder: the cement containing 20% gypsum develops the best behaviour. This is explained by the microstructure of the hydrated paste: in the paste containing 30% gypsum, delayed ettringite precipitates and damages the hardened paste.

Peysson, S. [Unite de Recherche en Genie Civil-MATERIAUX, Institut National des Sciences Appliquees de Lyon, Domaine Scientifique de la Doua, Batiment J. Tuset, 12, Avenue des Arts, 69 621 Villeurbanne Cedex (France); Pera, J. [Unite de Recherche en Genie Civil-MATERIAUX, Institut National des Sciences Appliquees de Lyon, Domaine Scientifique de la Doua, Batiment J. Tuset, 12, Avenue des Arts, 69 621 Villeurbanne Cedex (France)]. E-mail: Jean.Pera@insa-lyon.fr; Chabannet, M. [Unite de Recherche en Genie Civil-MATERIAUX, Institut National des Sciences Appliquees de Lyon, Domaine Scientifique de la Doua, Batiment J. Tuset, 12, Avenue des Arts, 69 621 Villeurbanne Cedex (France)

2005-12-15T23:59:59.000Z

454

Thermodynamics of geothermal fluids  

DOE Green Energy (OSTI)

A model to predict the thermodynamic properties of geothermal brines, based on a minimum amount of experimental data on a few key systems, is tested. Volumetric properties of aqueous sodium chloride, taken from the literature, are represented by a parametric equation over the range 0 to 300{sup 0}C and 1 bar to 1 kbar. Density measurements at 20 bar needed to complete the volumetric description also are presented. The pressure dependence of activity and thermal properties, derived from the volumetric equation, can be used to complete an equation of state for sodium chloride solutions. A flow calorimeter, used to obtain heat capacity data at high temperatures and pressures, is described. Heat capacity measurements, from 30 to 200{sup 0}C and 1 bar to 200 bar, are used to derive values for the activity coefficient and other thermodynamic properties of sodium sulfate solutions as a function of temperature. Literature data on the solubility of gypsum in mixed electrolyte solutions have been used to evaluate model parameters for calculating gypsum solubility in seawater and natural brines. Predictions of strontium and barium sulfate solubility in seawater also are given.

Rogers, P.S.Z.

1981-03-01T23:59:59.000Z

455

Protocol for determination of chemical warfare agent simulant movement through porous media  

SciTech Connect

In the event of an unplanned release of chemical warfare agent during any phase of the Chemical Stockpile Disposal Program (CSDP), a (small) potential exists for contamination of buildings and materials used in their construction. Guidelines for unrestricted access to potentially agent-contaminated private and public property are presently undefined due to uncertainties regarding the adequacy of decontaminating porous surfaces such as wood, masonry and gypsum wall board. Persistent agents such as VX or mustard are particularly problematic. The report which follows documents a measurement protocol developed in a scoping investigation characterizing the permeation of chemical warfare agent simulants (diisopropylmethyl phosphonate (DIMP) for warfare agent GB, dimethylmethyl phosphonate (DMMP) for warfare agent VX and chlorethylethyl sulfide (CEES) for warfare agent sulfur mustard) through several, common porous, construction materials. The porous media'' selected for examination were wood, brick, cinder block, and gypsum wall board. Simulants were tested rather than actual warfare agents because of their low toxicity, commercial availability, and the lack of surety capability at Oak Ridge National Laboratory (ORNL). The present work is considered a protocol for confirmation testing with live'' agents.

Jenkins, R.A.; Buchanan, M.V.; Merriweather, R.; Ilgner, R.H.; Gayle, T.M.; Moneyhun, J.H.; Watson, A.P.

1992-07-01T23:59:59.000Z

456

Protocol for determination of chemical warfare agent simulant movement through porous media  

SciTech Connect

In the event of an unplanned release of chemical warfare agent during any phase of the Chemical Stockpile Disposal Program (CSDP), a (small) potential exists for contamination of buildings and materials used in their construction. Guidelines for unrestricted access to potentially agent-contaminated private and public property are presently undefined due to uncertainties regarding the adequacy of decontaminating porous surfaces such as wood, masonry and gypsum wall board. Persistent agents such as VX or mustard are particularly problematic. The report which follows documents a measurement protocol developed in a scoping investigation characterizing the permeation of chemical warfare agent simulants [diisopropylmethyl phosphonate (DIMP) for warfare agent GB, dimethylmethyl phosphonate (DMMP) for warfare agent VX and chlorethylethyl sulfide (CEES) for warfare agent sulfur mustard] through several, common porous, construction materials. The ``porous media`` selected for examination were wood, brick, cinder block, and gypsum wall board. Simulants were tested rather than actual warfare agents because of their low toxicity, commercial availability, and the lack of surety capability at Oak Ridge National Laboratory (ORNL). The present work is considered a protocol for confirmation testing with ``live`` agents.

Jenkins, R.A.; Buchanan, M.V.; Merriweather, R.; Ilgner, R.H.; Gayle, T.M.; Moneyhun, J.H.; Watson, A.P.

1992-07-01T23:59:59.000Z

457

Prepared for:  

E-Print Network (OSTI)

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. This report presents and discusses results from the project “Fate of Mercury in Synthetic Gypsum Used for Wallboard Production, ” performed at five different full-scale commercial wallboard plants. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. This practice has

Jessica Sanderson; Gary M. Blythe; Mandi Richardson; Charles Miller

2008-01-01T23:59:59.000Z

458

Composite materials for thermal energy storage  

DOE Patents (OSTI)

The present invention discloses composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These phase change materials do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions, such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

Benson, David K. (Golden, CO); Burrows, Richard W. (Conifer, CO); Shinton, Yvonne D. (Northglenn, CO)

1986-01-01T23:59:59.000Z

459

Composite materials for thermal energy storage  

DOE Patents (OSTI)

A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

Benson, D.K.; Burrows, R.W.; Shinton, Y.D.

1985-01-04T23:59:59.000Z

460

Waste-form development for conversion to portland cement at Los Alamos National Laboratory (LANL) Technical Area 55 (TA-55)  

Science Conference Proceedings (OSTI)

The process used at TA-55 to cement transuranic (TRU) waste has experienced several problems with the gypsum-based cement currently being used. Specifically, the waste form could not reliably pass the Waste Isolation Pilot Plant (WIPP) prohibition for free liquid and the Environmental Protection Agency (EPA)-Toxicity Characteristic Leaching Procedure (TCLP) standard for chromium. This report describes the project to develop a portland cement-based waste form that ensures compliance to these standards, as well as other performance standards consisting of homogeneous mixing, moderate hydration temperature, timely initial set, and structural durability. Testing was conducted using the two most common waste streams requiring cementation as of February 1994, lean residue (LR)- and oxalate filtrate (OX)-based evaporator bottoms (EV). A formulation with a pH of 10.3 to 12.1 and a minimum cement-to-liquid (C/L) ratio of 0.80 kg/l for OX-based EV and 0.94 kg/L for LR-based EV was found to pass the performance standards chosen for this project. The implementation of the portland process should result in a yearly cost savings for raw materials of approximately $27,000 over the gypsum process.

Veazey, G.W.; Schake, A.R.; Shalek, P.D.; Romero, D.A.; Smith, C.A.

1996-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


461

lntersubbancl transitions in high indium content InGaAs/AIGaAs quantum wells  

E-Print Network (OSTI)

lntersubbancl transitions in high indium content InGaAs/AIGaAs quantum wells H. C. Chui, S. M. Lord report the first observation of intersubband transitions in In,Ga, -#s(y=O.3,0.5)/ AlGaAs quantum wells. These quantum wells were grown on a GaAs substrate with a linearly graded InGaAs buffer to achieve strain

Fejer, Martin M.

462

Manufacturing of ultra-high efficiency thin-film concentrator cells  

DOE Green Energy (OSTI)

This report describes a research project to study developments required to expedite commercializing the GaAs solar cell concentrator technology. We baseline the GaAs concentrator cell and 1000X module design into pilot operation at Kopin Corporation. To attain these improvements, we will use Kopin's existing pilot line to produce cleavage of lateral epitaxial film for transfer (CLEFT) GaAs solar cells; these cells already exhibit efficiencies of about 24% at air mass 1.5. We will modify the CLEFT cell to form concentrators that perform well at 500--1000 suns. We will derive the know-how for this modification from an integration of Kopin and VS Corporation technologies. The pilot line will be broadened to include cell receiver and module assembly, using VS Corporation technology obtained from Varian as a baseline. A second-generation design will be formulated to address improvements in the module, and these will be incorporated into the pilot line along with the CLEFT concentrator cell. In parallel, we integrate Kopin's CLEFT GaAs cell technology with the advanced AlGaAs and InGaAs material technology obtained by VS Corporation from Varian to develop a near-term, two-junction mechanical stack with an efficiency of 35%. The receiver thus developed will be compatible with a three-junction approach that has been proposed elsewhere by Kopin. Using a three-junction stack can yield an efficiency of over 40%, and when such cells become available, the pilot line process will have been designed to use them. 11 refs.

Gale, R. (Kopin Corp., Taunton, MA (United States))

1992-02-01T23:59:59.000Z

463

Study of clusters using negative ion photodetachment spectroscopy  

SciTech Connect

The weak van der Waals interaction between an open-shell halogen atom and a closed-shell atom or molecule has been investigated using zero electron kinetic energy (ZEKE) spectroscopy. This technique is also applied to study the low-lying electronic states in GaAs and GaAs{sup {minus}}. In addition, the spectroscopy and electron detachment dynamics of several small carbon cluster anions are studied using resonant multiphoton detachment spectroscopy.

Zhao, Yuexing

1995-12-01T23:59:59.000Z

464

Current and lattice matched tandem solar cell  

DOE Patents (OSTI)

A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga.sub.x In.sub.1-x P (0.505.ltoreq.X.ltoreq.0.515) top cell semiconductor lattice matched to a GaAs bottom cell semiconductor at a low-resistance heterojunction, preferably a p+/n+ heterojunction between the cells. The top and bottom cells are both lattice matched and current matched for high efficiency solar radiation conversion to electrical energy.

Olson, Jerry M. (Lakewood, CO)

1987-01-01T23:59:59.000Z

465

Heterojunction solar cell  

DOE Patents (OSTI)

A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

Olson, J.M.

1994-08-30T23:59:59.000Z

466

Heterojunction solar cell  

DOE Patents (OSTI)

A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.

Olson, Jerry M. (Lakewood, CO)

1994-01-01T23:59:59.000Z

467

Understanding the Potential and Limitations of Dilute Nitride Alloys for Solar Cells  

DOE Green Energy (OSTI)

Dilute nitride alloys provide a powerful tool for engineering the band gap and lattice constant of III-V alloys. However, nitrogen degrades the performance of GaAs solar cells. This project seeks to understand and demonstrate the limits of performance of GaInNAs alloys by (a) correlating deep-level transient spectroscopy (DLTS) data with device performance and (b) using molecular beam epitaxy (MBE) to reduce background impurity concentrations.

Kurtz, S.; Ptak, A.; Johnston, S.; Kramer, C.; Young, M.; Friedman, D.; Geisz, J.; McMahon, W.; Kibbler, A.; Olson, J.; Crandall, R.; Branz, H.

2005-11-01T23:59:59.000Z

468

Dry etching device quality high-? GaxGdyOz gate oxide in SiCl4 chemistry for low resistance ohmic contact realisation in fabricating III-V MOSFETs  

Science Conference Proceedings (OSTI)

This paper investigates the reactive ion etching (RIE) of Ga"xGd"yO"z, a device quality high-@k gate oxide for a low resistance ohmic contact realisation in fabricating III-V metal-oxide semiconductor field-effect-transistors (MOSFETs) based on high ... Keywords: Dry etching, Ga2O3-Gd2O3, GaxGdyOz, GaAs MOSFET, High-? oxide, RIE, SiCl4

X. Li; H. Zhou; R. J. W. Hill; P. Longo; M. Holland; I. G. Thayne

2010-05-01T23:59:59.000Z

469

Guiding effect of quantum wells in semiconductor lasers  

Science Conference Proceedings (OSTI)

The guiding effect of InGaAs quantum wells in GaAs- and InP-based semiconductor lasers has been studied theoretically and experimentally. The results demonstrate that such waveguides can be effectively used in laser structures with a large refractive index difference between the quantum well material and semiconductor matrix and a large number of quantum wells (e.g. in InP-based structures). (semiconductor lasers. physics and technology)

Aleshkin, V Ya; Dikareva, Natalia V; Dubinov, A A; Zvonkov, B N; Karzanova, Maria V; Kudryavtsev, K E; Nekorkin, S M; Yablonskii, A N

2013-05-31T23:59:59.000Z

470

High-harmonic XUV source for time- and angle-resolved photoemission spectroscopy  

Science Conference Proceedings (OSTI)

We present a laser-based apparatus for visible pump/XUV probe time- and angle-resolved photoemission spectroscopy (TRARPES) utilizing high-harmonic generation from a noble gas. Femtosecond temporal resolution for each selected harmonic is achieved by using a time-delay-compensated monochromator (TCM). The source has been used to obtain photoemission spectra from insulators (UO{sub 2}) and ultrafast pump/probe processes in semiconductors (GaAs).

Dakovski, Georgi L [Los Alamos National Laboratory; Li, Yinwan [Los Alamos National Laboratory; Durakiewicz, Tomasz [Los Alamos National Laboratory; Rodriguez, George [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

471

Recent Polarized Photocathode R& D at SLAC  

DOE Green Energy (OSTI)

The SLAC high-gradient-doped MOCVD-grown GaAs cathode presently in use consists of a strained GaAs low-doped layer (with a small admixture of P) capped by a few nanometers of highly Zn-doped GaAs, which is heat-cleaned at relatively high temperature and then activated by Cs/NF{sub 3} co-deposition. The high-gradient-doped structure solves the problem of the surface charge limit that the previously-used SLAC cathodes had, and this preparation procedure has produced satisfactory results. However, the preparation procedure has a few weaknesses that prevent cathodes from achieving the ultimate desired performance. The peak polarization is limited to 80% due to strain relaxation in the relatively thick strained layers. Also dopant loss causes the surface charge limit effect to reappear after multiple high-temperature heat-cleanings. In this paper, we will discuss recent progress made at SLAC that addresses these limitations, including using the MBE growth technique with Be doping and using the superlattice structure. In addition, to reduce the heat-cleaning temperature, an atomic hydrogen cleaning technique is explored.

Luh, Dah-An

2002-12-13T23:59:59.000Z

472

50 kWp Photovoltaic Concentrator Application Experiment, Phase I. Final report, 1 June 1978-28 February 1979  

DOE Green Energy (OSTI)

This program consists of a design study and component development for an experimental 50-kWp photovoltaic concentrator system to supply power to the San Ramon substation of the Pacific Gas and Electric Company. The photovoltaic system is optimized to produce peaking power to relieve the air conditioning load on the PG and E system during summer afternoons; and would therefore displace oil-fired power generation capacity. No electrical storage is required. The experiment would use GaAs concentrator cells with point-focus fresnel lenses operating at 400X, in independent tracking arrays of 440 cells each, generating 3.8 kWp. Fourteen arrays, each 9 feet by 33 feet, are connected electrically in series to generate the 50 kWp. The high conversion efficiency possible with GaAs concentrator cells results in a projected annual average system efficiency (AC electric power output to sunlight input) of better than 15%. The capability of GaAs cells for high temperature operation made possible the design of a total energy option, whereby thermal power from selected arrays could be used to heat and cool the control center for the installation. System design and analysis, fabrication and installation, environmental assessment, and cost projections are described in detail. (WHK)

Maget, H.J.R.

1979-06-15T23:59:59.000Z

473

Time-resolved resonance and linewidth of an ultrafast switched GaAs/AlAs microcavity  

E-Print Network (OSTI)

We explore a planar GaAs/AlAs photonic microcavity using pump-probe spectroscopy. Free carriers are excited in the GaAs with short pump pulses. The time-resolved reflectivity is spectrally resolved short probe pulses. We show experimentally that the cavity resonance and its width depend on the dynamic refractive index of both the lambda-slab and the lambda/4 GaAs mirrors. We clearly observe a double exponential relaxation of both the the cavity resonance and its width, which is due to the different recombination timescales in the lambda-slab and the mirrors. In particular, the relaxation time due to the GaAs mirrors approaches the photon storage time of the cavity, a regime for which nonlinear effects have been predicted. The strongly non-single exponential behavior of the resonance and the width is in excellent agreement to a transfer-matrix model taking into account two recombination times. The change in width leads to a change in reflectivity modulation depth. The model predicts an optimal cavity Q for any...

Harding, Philip J; Hartsuiker, Alex; Nowicki-Bringuier, Yoanna-Reine; Gerard, Jean-Michel; Vos, Willem L

2009-01-01T23:59:59.000Z

474

Advanced high efficiency concentrator cells  

DOE Green Energy (OSTI)

This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

Gale, R. (Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center)

1992-06-01T23:59:59.000Z

475

Advanced high efficiency concentrator cells. Final subcontractor report, 1 October 1988--31 March 1990  

DOE Green Energy (OSTI)

This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the ``reverse`` side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

Gale, R. [Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center

1992-06-01T23:59:59.000Z

476

New Materials for Future Generations of III-V Solar Cells  

DOE Green Energy (OSTI)

Three- and four-junction III-V devices are proposed for ultrahigh-efficiency solar cells using a new 1-eV material lattice-matched to GaAs, namely, GaInNAs. We demonstrate working prototypes of a GaInNAs-based solar cell lattice-matched to GaAs with photoresponse down to 1 eV. Under the AM1.5 direct spectrum with all the light higher in energy than the GaAs band gap filtered out, the prototypes grown with base doping of about 10{sup 17} cm-3 have open-circuit voltages ranging from 0.35 to 0.44 V, short-circuit current densities of 1.8 mA/cm2, and fill factors from 61% to 66%. To improve on the current record-efficiency tandem GaInP/GaAs solar cell by adding a GaInNAs junction, the short-circuit current density of this 1-eV cell must be significantly increased. Because these low short-circuit current densities are due to short diffusion lengths, we have demonstrated a depletion-width-enhanced variation of one of the prototype devices that trades off decreased voltage for increased photocurrent, with a short-circuit current density of 7.4 mA/cm2 and an open-circuit voltage of 0.28 V.

Geisz, J. F.; Friedman, D. J.; Olson, J. M.; Kramer, C.; Kibbler, A.; Kurtz, S. R.

1998-10-06T23:59:59.000Z

477

NETL: Clean Coal Technology Demonstration Program (CCTDP) - Round 2  

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

2 2 Environmental Control Technologies - SO2 Control Technologies Demonstration of Innovative Applications of Technology for the CT-121 FGD Process - Project Brief [PDF-265KB] Southern Company Services, Newnan, GA PROGRAM PUBLICATIONS Final Reports Demonstration of Innovative Applications of Technology for the CT-121 FGD Process, Final Report (Jan 1997) Volume 1, Executive Summary [PDF-4.6MB] Volume 2, Operation [PDF-32.8MB] Volume 2 Appendices [PDF-6.3MB] Volume 3, Equipment Vol 3a, Materials and Maintenance [PDF-34.6MB] Vol 3b, Instrumentation and Control [PDF-1.2MB] Vol 3c, Materials Test & Evaluation Program [PDF-28.2MB] Volume 4, Gypsum Stacking &Byproduct Evaluation [PDF-11.3MB] Volume 5, Environmental Monitoring Plan [PDF-3MB] Volume 5 Appendices [PDF-5.8MB]

478

Insulation Strategies to Meet Upcoming Code and Above Code Programs  

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

Insulation Strategies to Meet Insulation Strategies to Meet Upcoming Code and Above Code Programs 1 Christopher Little, BASF Corporation, Center for Building Excellence 3/2/2012 Presentation Overview Innovative insulating & wall assembly strategies  Typical assembly  New innovations  Features & benefits of each 2 3/2/2012 Typical Site Built Residential Wall Concept: Site built wood frame wall with exterior sheathing and batt insulation Components:  Exterior Finish (bulk moisture control)  Building wrap  Exterior sheathing 2x4 Studs @16" O.C.  Batt Insulation (+/- 3.7 R per inch)  Gypsum board Benefits: Relatively low cost ICF Site-built 3 3/2/2012 Typical Site Built Residential Wall Key performance deficiencies  Low effective R-value  Difficulty meeting IECC 2012 R-value

479

Buildings Energy Data Book: 9.4 High Performance Buildings  

Buildings Energy Data Book (EERE)

3 3 Case Study, The Visitor Center at Zion National Park, Utah (Service/Retail/Office) Building Design Vistors Center (1): 8,800 SF Comfort Station (2): 2,756 SF Fee Station: 170 SF Shell Windows Type U-Factor SHGC (3) South/East Glass Double Pane Insulating Glass, Low-e, Aluminum Frames, Thermally Broken 0.44 0.44 North/West Glass Double Pane Insulating Glass, Heat Mirror, Aluminum Frames, Thermally Broken 0.37 0.37 Window/Wall Ratio: 28% Wall/Roof Materials Effective R-Value Trombe Walls: Low-iron Patterned Trombe Wall, CMU (4) 2.3 Vistor Center Walls: Wood Siding, Rigid Insulation Board, Gypsum 16.5 Comfort Station Walls: Wood Siding, Rigid Insulation Board, CMU (4) 6.6 Roof: Wood Shingles; Sheathing; Insulated Roof Panels 30.9 HVAC Heating Cooling Trombe Walls Operable Windows Electric Radiant Ceiling Panels

480

CX-009806: Categorical Exclusion Determination | Department of Energy  

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

806: Categorical Exclusion Determination 806: Categorical Exclusion Determination CX-009806: Categorical Exclusion Determination C-CA-CAM Building Complex Demolition and Site Restoration CX(s) Applied: B1.11, B1.16, B1.17, B1.23, B1.24, B1.27, B1.30, B1.33, B1.34 Date: 01/09/2013 Location(s): Pennsylvania Offices(s): Naval Nuclear Propulsion Program The scope of the C-CA-CAM Building Complex demolition includes removal and disposal of concrete, gypsum, roof and wall panels, structural steel, abandoned interior and exterior utilities, and ancillary components and structures not suitable for reuse. The C-CA-CAM Building Complex site restoration will include backfilling, grading, and hydro seeding for erosion control. With a building footprint reduction of 25,448 square feet, a total of approximately 40,000 square feet total of site area will become

Note: This page contains sample records for the topic "arsenide gaas gypsum" 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.


481

CX-009806: Categorical Exclusion Determination | Department of Energy  

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

806: Categorical Exclusion Determination 806: Categorical Exclusion Determination CX-009806: Categorical Exclusion Determination C-CA-CAM Building Complex Demolition and Site Restoration CX(s) Applied: B1.11, B1.16, B1.17, B1.23, B1.24, B1.27, B1.30, B1.33, B1.34 Date: 01/09/2013 Location(s): Pennsylvania Offices(s): Naval Nuclear Propulsion Program The scope of the C-CA-CAM Building Complex demolition includes removal and disposal of concrete, gypsum, roof and wall panels, structural steel, abandoned interior and exterior utilities, and ancillary components and structures not suitable for reuse. The C-CA-CAM Building Complex site restoration will include backfilling, grading, and hydro seeding for erosion control. With a building footprint reduction of 25,448 square feet, a total of approximately 40,000 square feet total of site area will become

482

CX-003969: Categorical Exclusion Determination | Department of Energy  

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

9: Categorical Exclusion Determination 9: Categorical Exclusion Determination CX-003969: Categorical Exclusion Determination Mobile Plutonium Facility (MPF); Set Up and Test Thermogravimetric Analyzer CX(s) Applied: B3.1 Date: 08/19/2010 Location(s): Aiken, South Carolina Office(s): Savannah River Operations Office The Mobile Plutonium Facility (MPF) glovebox process will require the use of a thermogravimetric analyzer (TGA). A mock up of the MPF gloveboxes has been built in 751-1A. There is a need to set up the TGA in both the mock up facility and in the MPF to ensure the equipment is functional and provide training to those who will use the equipment in the future. A Perkin-Elmer STA-6000 TGA will be installed using vendor supplied information. Standard materials such as gypsum and sodium bicarbonate may be used for process

483

U.S. Department of Energy Categorical Exclusion Determination Form  

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

Thermogravimetric Analysis and Mass Spectrometer in SRNL GB-49 Thermogravimetric Analysis and Mass Spectrometer in SRNL GB-49 Savannah River Site Aiken/Aiken/South Carolina A thermogravimetric analyzer (TGA) combined with a mass spectrometer (MS) are located in 773-A, C-154/158. The TGA unit is installed inside an active glovebox (GB-49) that serves as radiological containment and is vented to the 773-A OGE system. The MS unit is located under GB-49 and pulls a small sample of gas from the TGA off-gas for analysis of volatile species like water vapor, carbon dioxide, nitrogen oxides, etc., that are formed during thermal treatment or decomposition of TGA samples. The MS exhaust vents into GB-49. Standard powder materials used (in < 1 g aliquots) to verify instrument operation include gypsum (CaSO4 2H2O), calcium oxalate, sodium bicarbonate, sand, hydrated salts, etc.

484

Taking stock, battening down, and gearing up: The industry prepares for the new rules  

SciTech Connect

As negotiators hammer out the 1990 Clean Air Act Amendment regulations, many control systems remain on the shelf. But the chemical industry's environmental managers have been far from idle, taking stock of emissions, tightening processes, and gearing up for what promises to be an expensive, dramatic change in the way the industry deals with air emissions. German firms are also trying to commercially leverage technologies developed to meet tough federal rules, especially those covering power plant emissions. Through its engineering business Uhde (Dortmund). Hoechst is licensing a flue-gas desulfurization technology used at its power plants since the late 1980s. The process uses activated coke - rather than the ammonia used in SCR - to oxidize SO[sub 2] to sulfur trioxide, which is then converted into reusable sulfuric acid, avoiding the gypsum produced by SCR processes.

Kirschner, E.

1992-11-04T23:59:59.000Z

485

North Carolina's 12th congressional district: Energy Resources | Open  

Open Energy Info (EERE)

12th congressional district: Energy Resources 12th congressional district: Energy Resources Jump to: navigation, search Equivalent URI DBpedia This article is a stub. You can help OpenEI by expanding it. This page represents a congressional district in North Carolina. US Recovery Act Smart Grid Projects in North Carolina's 12th congressional district Duke Energy Business Services LLC Smart Grid Project Duke Energy Business Services, LLC Smart Grid Demonstration Project Duke Energy Carolinas, LLC Smart Grid Project Registered Energy Companies in North Carolina's 12th congressional district Abundant Power Bank of America Camstar Systems Inc Celgard LLC Coalogix Inc Dragonfly Capital Duke Power Greenwood Capital Partners MCF Advisors LLC Methane Credit Metso Power National Gypsum NewGen Fuel Technologies Ltd NewGen Technologies Inc Formerly Bongiovi Entertainment Inc

486

Hyperspectral Mineral Mapping For Geothermal Exploration On The Pyramid  

Open Energy Info (EERE)

Hyperspectral Mineral Mapping For Geothermal Exploration On The Pyramid Hyperspectral Mineral Mapping For Geothermal Exploration On The Pyramid Lake Paiute Reservation, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Hyperspectral Mineral Mapping For Geothermal Exploration On The Pyramid Lake Paiute Reservation, Nevada Details Activities (2) Areas (1) Regions (0) Abstract: Over 2000 km2 (772 mi2) of 5 m resolution Hymap hyperspectral data was acquired over the Pyramid Lake Paiute Reservation in the Fall of 2004. Subsequent image processing and data analysis has identified reflectance spectra for alunite, kaolinite/halloysite, illite, gypsum, vegetation, and carbonate. A portable spectrometer is being used for in situ validation, along with laboratory measurements and X-ray diffraction analyses of samples collected in the field. We are in the process of

487

Multispectral Imaging At The Needles Area (Kratt, Et Al., 2005) | Open  

Open Energy Info (EERE)

Multispectral Imaging At The Needles Area (Kratt, Et Al., 2005) Multispectral Imaging At The Needles Area (Kratt, Et Al., 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Multispectral Imaging At The Needles Area (Kratt, Et Al., 2005) Exploration Activity Details Location The Needles Area Exploration Technique Multispectral Imaging Activity Date Usefulness not indicated DOE-funding Unknown Notes Over 2000 km2 of 5-m resolution Hymap hyperspectral data was acquired in 2004. Subsequent image processing and data analysis has identified reflectance spectra for alunite, kaolinite/halloysite, illite, gypsum, vegetation, and carbonate. A portable spectrometer is being used for in situ validation, along with laboratory measurements and x-ray diffraction analyses of samples collected in teh field. We are in the process of

488

Slide 1  

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

Carbon-dioxide Absorber Carbon-dioxide Absorber Retrofit Equipment (CARE) Program 2013 CO 2 Capture Technology Meeting Dr. Andrew Awtry, Principal Scientist, Neumann Systems Group andya@neumannsystemsgroup.com (719)247-8519 1 NeuStream ® Pollution-to-Products TM Systems Fertilizer Gold Ore Processing Plants Pulp & Paper Mills Steel Manufacturing Plants Aluminum Processing Plants Rare Earth Metals Gypsum Cement Plants Industrial Products Fossil Fuel Power Plants Fertilizer Sulfuric Acid CO 2 SO X NO X Enhanced Oil Recovery * Sulfur Oxides (SO X ) * Nitrogen Oxides (NO X ) * Carbon Dioxide (CO 2 ) * Particulates (PM) * Heavy Metals, Organics Pollutants Pollutants captured and transformed into vital industrial products $2.3M/yr* >$1 BILLION revenue from P-to-P from a single 550MW coal plant*

489

Rock Sampling At The Needles Area (Kratt, Et Al., 2005) | Open Energy  

Open Energy Info (EERE)

The Needles Area (Kratt, Et Al., 2005) The Needles Area (Kratt, Et Al., 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Rock Sampling At The Needles Area (Kratt, Et Al., 2005) Exploration Activity Details Location The Needles Area Exploration Technique Rock Sampling Activity Date Usefulness not indicated DOE-funding Unknown Notes Over 2000 km2 of 5-m resolution Hymap hyperspectral data was acquired in 2004. Subsequent image processing and data analysis has identified reflectance spectra for alunite, kaolinite/halloysite, illite, gypsum, vegetation, and carbonate. A portable spectrometer is being used for in situ validation, along with laboratory measurements and x-ray diffraction analyses of samples collected in teh field. We are in the process of producing and validating mineral maps that will be used to narrow the scope

490

A Mineralogical Petrographic And Geochemical Study Of Samples From Wells In  

Open Energy Info (EERE)

Mineralogical Petrographic And Geochemical Study Of Samples From Wells In Mineralogical Petrographic And Geochemical Study Of Samples From Wells In The Geothermal Field Of Milos Island (Greece) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Mineralogical Petrographic And Geochemical Study Of Samples From Wells In The Geothermal Field Of Milos Island (Greece) Details Activities (0) Areas (0) Regions (0) Abstract: This paper presents a study of hydrothermal alteration on Milos island, Greece. Examination of cores and cuttings from the two drill sites, obtained from a depth of about 1100 m in Milos geothermal field, showed that the hydrothermal minerals occurring in the rock include: K-feldspar, albite, chlorite, talc, diopside, epidote, muscovite, tremolite, kaolinite, montmorillonite, alunite, anhydrite, gypsum, calcite, and opaque minerals.

491

DOI: 10.1016/j.gca.2008.09.007 Measurement of the pure dissolution rate constant of a mineral in water  

E-Print Network (OSTI)

Abstract — We present here a methodology, using holographic interferometry, enabling to measure the pure surface reaction rate constant of the dissolution of a mineral in water, unambiguously free from the influence of mass transport. We use that technique to access to this value for gypsum and we demonstrate that it was never measured before but could be deduced a posteriori from the literature results if hydrodynamics is taken into account with accuracy. It is found to be much smaller than expected. This method enables to provide reliable rate constants for the test of dissolution models and the interpretation of in situ measurements, and gives clues to explain the inconsistency between dissolution rates of calcite and aragonite, for instance, in the literature. 1

Jean Colombani

2008-01-01T23:59:59.000Z

492

Measurement of the pure dissolution rate constant of a mineral in water  

E-Print Network (OSTI)

We present here a methodology, using holographic interferometry, enabling to measure the pure surface reaction rate constant of the dissolution of a mineral in water, unambiguously free from the influence of mass transport. We use that technique to access to this value for gypsum and we demonstrate that it was never measured before but could be deduced a posteriori from the literature results if hydrodynamics is taken into account with accuracy. It is found to be much smaller than expected. This method enables to provide reliable rate constants for the test of dissolution models and the interpretation of in situ measurements, and gives clues to explain the inconsistency between dissolution rates of calcite and aragonite, for instance, in the literature.

Colombani, Jean

2009-01-01T23:59:59.000Z

493

Measurement of the pure dissolution rate constant of a mineral in water  

E-Print Network (OSTI)

We present here a methodology, using holographic interferometry, enabling to measure the pure surface reaction rate constant of the dissolution of a mineral in water, unambiguously free from the influence of mass transport. We use that technique to access to this value for gypsum and we demonstrate that it was never measured before but could be deduced a posteriori from the literature results if hydrodynamics is taken into account with accuracy. It is found to be much smaller than expected. This method enables to provide reliable rate constants for the test of dissolution models and the interpretation of in situ measurements, and gives clues to explain the inconsistency between dissolution rates of calcite and aragonite, for instance, in the literature.

Jean Colombani

2009-11-26T23:59:59.000Z

494

CO2 Capture by Absorption with Potassium Carbonate  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. The pilot plant data have been reconciled using 17% inlet CO{sub 2}. A rate-based model demonstrates that the stripper is primarily controlled by liquid film mast transfer resistance, with kinetics at vacuum and diffusion of reactants and products at normal pressure. An additional major unknown ion, probably glyoxylate, has been observed in MEA degradation. Precipitation of gypsum may be a feasible approach to removing sulphate from amine solutions and providing for simultaneous removal of CO{sub 2} and SO{sub 2}. Corrosion of carbon steel in uninhibited MEA solution is increased by increased amine concentration, by addition of piperazine, and by greater CO{sub 2} loading.

Gary T. Rochelle; Eric Chen; Babatunde Oyenekan; Andrew Sexton; Jason Davis; Marcus Hilliard; Amorvadee Veawab

2006-07-28T23:59:59.000Z

495

Coal-ash spills highlight ongoing risk to ecosystems  

SciTech Connect

Two recent large-scale spills of coal combustion waste have highlighted the old problem of handling the enormous quantity of solid waste produced by coal. Both spills happened at power plants run by the Tennessee Valley Authority (TVA). In December 2008 a holding pond for coal ash collapsed at a power plant in Kingstom, Tenn., releasing coal-ash sludge onto farmland and into rivers: in January 2009 a break in a pipe removing water from a holding pond for gypsum caused a spill at Widows Creek Fossil Plant in Stevenson, Ala. The article discusses the toxic outcome of such disasters on ecosystems, quoting work by Willaim Hopkins at Virginia Polytechnic Institute and State University and recommendations and reports of the US EPA. 2 photos.

Chatterjee, R.

2009-05-01T23:59:59.000Z

496

Geology of Nevada: The  

E-Print Network (OSTI)

Geology plays a central role in Nevada’s human history, economy, and future. Cordilleran tectonics have created the Basin and Range landscape and interior drainage of the Great Basin, provided a rain shadow to make Nevada the nation’s driest state, and generated frequent earthquakes along normal and strike-slip faults. Geology is key to reducing risks from Nevada’s natural and anthropogenic hazards (earthquakes, flash floods, drought, land subsidence, erosion after wildland fires, landslides, swelling and collapsing soils, radon, arsenic, and others). Nevada’s geologic fortunes make it the leading state in the production of gold, silver, barite, lithium, and mercury and a major producer of geothermal power and gypsum. The metals are primarily related to igneous activity, with major pulses of magma during the Jurassic, Cretaceous, and Tertiary. Barite is mined from Paleozoic

Jonathan G. Price

2002-01-01T23:59:59.000Z

497

Advanced Flue Gas Desulfurization (AFGD) Demonstration Project. Technical progress report No. 15, July 1, 1993--September 30, 1993  

Science Conference Proceedings (OSTI)

The goal of this project is to demonstrate that, by combining state-of-the-art technology, highly efficient plant operation and maintenance capabilities and by-product gypsum sales, significant reductions of SO{sub 2} emissions can be achieved at approximately one-half the life cycle cost of a conventional Flue Gas Desulfurization (FGD) system. Further, this emission reduction is achieved without generating solid waste and while minimizing liquid wastewater effluent. Basically, this project entails the design, construction and operation of a nominal 600 MWe AFGD facility to remove SO{sub 2} from coal-fired power plant flue gas at the Northern Indiana Public Service Company`s Bailly Generating Station.

Not Available

1994-08-01T23:59:59.000Z

498

Calcifying Cyanobacteria - The potential of biomineralization for Carbon Capture and Storage  

DOE Green Energy (OSTI)

Employment of cyanobacteria in biomineralization of carbon dioxide by calcium carbonate precipitation offers novel and self-sustaining strategies for point-source carbon capture and sequestration. Although details of this process remain to be elucidated, a carbon-concentrating mechanism, and chemical reactions in exopolysaccharide or proteinaceous surface layers are assumed to be of crucial importance. Cyanobacteria can utilize solar energy through photosynthesis to convert carbon dioxide to recalcitrant calcium carbonate. Calcium can be derived from sources such as gypsum or industrial brine. A better understanding of the biochemical and genetic mechanisms that carry out and regulate cynaobacterial biomineralization should put us in a position where we can further optimize these steps by exploiting the powerful techniques of genetic engineering, directed evolution, and biomimetics.

Jansson, Christer G; Northen, Trent

2010-03-26T23:59:59.000Z

499

Quarterly minerals outlook, June 1983  

Science Conference Proceedings (OSTI)

An overview is presented of the mineral industry of Wyoming. Petroleum production shows a slight annual decline. Many producers have been shutting in their natural gas wells due to the sharp decline in demand. Activities in the base, precious, and ferrous metals industry are summarized. Uranium and trona production is down from the previous year. Other minerals mentioned are gypsum, limestone, bentonite, and phosphorus. Production of coal is given by county. Electric utilities have not used all the coal they bought last year, and construction of several power plants have been delayed indefinitely. Underground coal gasification projects are mentioned. Tables present production forecasts for coal to 1990, for oil and gas to 1988, and for uranium and trona to 1987. 5 tables.

Glass, G.B.

1983-01-01T23:59:59.000Z

500

Radon emanation coefficients for phosphogysum  

Science Conference Proceedings (OSTI)

Phosphogypsum is a by-product of the phosphate fertilizer industry which is stockpiled in large quantities world-wide. Phosphogypsum consists mainly of dihydrate gypsum (CaSO{sub 4}2H{sub 2}O) but also contains elevated concentrations of {sup 226}Ra and other inorganic species which originate from the processing of phosphate rock. {sup 222}Rn gas is the first decay product of {sup 226}Ra and ha