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Note: This page contains sample records for the topic "aerodynamic particle sizing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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1

A Study of the Effect of Size on Ice Nucleation in the Aerodynamic Range of Particles  

Science Conference Proceedings (OSTI)

The effect of size on ice nucleation has been experimentally investigated for aerosol particles in the aerodynamic range. Aerosol particles are separated according to their aerodynamic diameter while airborne and deposited on a membrane filter ...

F. Prodi; G. Santachiara; V. Prodi

1982-07-01T23:59:59.000Z

2

Aerodynamic particle size measurement by laser--Doppler velocimetry. Publication number 343  

DOE Green Energy (OSTI)

A method of measuring the aerodynamic diameter of aerosol particles was investigated. The method consists of accelerating particles in a coverging nozzle and measuring their velocities near the exit of th nozzle with a laser--Doppler velocimeter. The experimental studies utilized a test nozzle with a converging angle of approximately 15/sup 0/ and an exit diameter of about .1 cm. The pressure drop across the nozzle was varied from 2.54 to 276 cm of H/sub 2/O, and particle velocity was observed to vary from approximately 0.5 to 1.0 times the gas velocity at the exit of the nozzle. A theoretical analysis utilized boundary layer theory to predict the velocity of the gas in the nozzle, and then the equations of particle motion were integrated to give the theoretical particle velocities. These values agreed with the experimental values to within a few percent. The effects of nozzle geometry, flow rate, particle density, and particle size were studied using the results of calculations made with dimensionless equations. The velocity of a particle in a given nozzle and flow depends upon the aerodynamic diameter of the particle and the particle density. The geometry and flow can be chosen to minimize the effect of particle density. Assuming that the density of particles in the atmosphere ranges from 1 g/cm/sup 3/ to 3 g/cm/sup 3/, the aerodynamic diameter of particles can be measured with an uncertainty of +- 10% in the size range from .5 ..mu..m to 10 ..mu..m.

Wilson, J.C.

1977-12-01T23:59:59.000Z

3

Developing Supersonic Impactor and Aerodynamic Lens for Separation and Handling of Nano-Sized Particles  

SciTech Connect

A computational model for supersonic flows of compressible gases in an aerodynamic lens with several lenses and in a supersonic/hypersonic impactor was developed. Airflow conditions in the aerodynamic lens were analyzed and contour plots for variation of Mach number, velocity magnitude and pressure field in the lens were evaluated. The nano and micro-particle trajectories in the lens and their focusing and transmission efficiencies were evaluated. The computational model was then applied to design of a aerodynamic lens that could generate focus particle beams while operating under atmospheric conditions. The computational model was also applied to airflow condition in the supersonic/hypersonic impactor. Variations of airflow condition and particle trajectories in the impactor were evaluated. The simulation results could provide understanding of the performance of the supersonic and hypersonic impactors that would be helpful for the design of such systems.

Goodarz Ahmadi

2008-06-30T23:59:59.000Z

4

Tandem Differential Mobility Analyzer/Aerodynamic Particle Sizer (APS) Handbook  

SciTech Connect

The tandem differential mobility analyzer (TDMA) is a single instrument that cycles through a series of complementary measurements of the physical properties of size-resolved submicron particles. In 2008, the TDMA was augmented through the addition of an aerodynamic particle sizer (APS), which extends the upper limit of the measured size distribution into the supermicron range. These two instruments are operated in parallel, but because they are controlled by a common computer and because the size distributions measured by the two are integrated in the produced datastreams, they are described together here. Throughout the day, the TDMA sequentially measures submicron aerosol size distributions and size-resolved hygroscopic growth distributions. More specifically, the instrument is operated as a scanning DMA to measure size distributions and as a TDMA to measure size-resolved hygroscopicity. A typical measurement sequence requires roughly 45 minutes. Each morning additional measurements are made of the relative humidity (RH) dependent hygroscopicity and temperature-dependent volatility of size-resolved particles. When the outside temperature and RH are within acceptable ranges, the hydration state of size-resolved particles is also characterized. The measured aerosol distributions complement the array of aerosol instruments in the Aerosol Observing System (AOS) and provide additional details of the light-scattering and cloud-nucleating characteristics of the aerosol.

Collins, D

2010-06-18T23:59:59.000Z

5

Indigenous development and performance evaluation of BARC aerodynamic size separator (BASS)  

E-Print Network (OSTI)

Commercially available cascade impactors, commonly used for aerodynamic size separation of aerosol particles, are based on the principle of inertial impaction. As of now, these instruments are imported at a cost of several lakhs of rupees; hence an effort has been made to develop an aerodynamic particle sizer indigenously in BARC. This unit, referred to as BARC Aerodynamic Size Separator (BASS), separates aerosols into seven size classes ranging from 0.53 mu m to 10 mu m and operates at a flow rate of 45 Ipm. Intercomparison studies between the standard Andersen Mark-II (Grasbey Andersen Inc.) impactor and BASS using nebulizer generated aerosols have consistently shown excellent performance by BASS in all respects. In particular, BASS yielded the parameters of polydisperse aerosols quite accurately. Experiments to evaluate the individual stage cut-off diameters show that these are within 8% of their designed value for all stages except the higher two stages which indicate about 30% lower values than the desig...

Singh, S; Khan, A; Mayya, Y S; Narayanan, K P; Purwar, R C; Sapra, B K; Sunny, F

2002-01-01T23:59:59.000Z

6

Aerodynamic size associations of natural radioactivity with ambient aerosols  

SciTech Connect

The aerodynamic size of /sup 214/Pb, /sup 212/Pb, /sup 210/Pb, /sup 7/Be, /sup 32/P, /sup 35/S (as SO/sub 4//sup 2 -/), and stable SO/sub 4//sup 2 -/ was measured using cascade impactors. The activity distribution of /sup 212/Pb and /sup 214/Pb, measured by alpha spectroscopy, was largely associated with aerosols smaller than 0.52 ..mu..m. Based on 46 measurements, the activity median aerodynamic diameter of /sup 212/Pb averaged 0.13 ..mu..m (sigma/sub g/ = 2.97), while /sup 214/Pb averaged 0.16 ..mu..m (sigma/sub g/ = 2.86). The larger median size of /sup 214/Pb was attributed to ..cap alpha..-recoil depletion of smaller aerosols following decay of aerosol-associated /sup 218/Po. Subsequent /sup 214/Pb condensation on all aerosols effectively enriches larger aerosols. /sup 212/Pb does not undergo this recoil-driven redistribution. Low-pressure impactor measurements indicated that the mass median aerodynamic diameter of SO/sub 4//sup 2 -/ was about three times larger than the activity median diameter /sup 212/Pb, reflecting differences in atmospheric residence times as well as the differences in surface area and volume distributions of the atmospheric aerosol. Cosmogenic radionuclides, especially /sup 7/Be, were associated with smaller aerosols than SO/sub 4//sup 2 -/ regardless of season, while /sup 210/Pb distributions in summer measurements were similar to sulfate but smaller in winter measurements. Even considering recoil following /sup 214/Po ..cap alpha..-decay, the avervage /sup 210/Pb labeled aerosol grows by about a factor of two during its atmospheric lifetime. The presence of 5 to 10% of the /sup 7/Be on aerosols greater than 1 ..mu..m was indicative of post-condensation growth, probably either in the upper atmosphere or after mixing into the boundary layer.

Bondietti, E.A.; Papastefanou, C.; Rangarajan, C.

1986-04-01T23:59:59.000Z

7

ARM - Measurement - Aerosol particle size  

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

particle size particle size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol particle size Linear size (e.g. radius or diameter) of an aerosol particle. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments AEROSMASSSPEC : Aerosol Mass Spectrometer CPI : Cloud Particle Imager DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments DRUM-AEROSOL : Drum Aerosol Sampler AEROSOL-TOWER-EML : EML Tower based Aerosol Measurements

8

Characterization of aerodynamic drag force on single particles: Final report  

Science Conference Proceedings (OSTI)

An electrodynamic balance was used to measure the drag coefficient and also to record the size and shape of spheres, and coal and oil shale particles (100 ..mu..m to 200 ..mu..m in size). The electrodynamic balance consisted of a central, and two end electrodes. The resulting electric field stably suspended a charged particle. A suspended particle, back illuminated by a light emitting diode, was viewed by a video camera. The image was analyzed for particle position control and was calibrated to give the diameter of spheres, or the area equivalent diameter of nonspherical particles. The drag coefficient was calculated from the air velocity and the dc voltage required to keep the particle at the balance center. The particle Reynolds number varied from 0.2 to 13. Three particles each of coal and oil shale were captured and photographed by a scanning electron microscope and the motion of all the particles was recorded on video tape. Drag coefficient vs Reynolds number data for spheres agreed well with correlations. Data for thirteen particles each of coal and oil shale indicated a power law relationship between drag coefficient and Reynolds number. All these particles exhibited higher drag than spheres and were also observed to rotate. The rotation, however, did not affect the drag coefficient. The choice of characteristic dimension affects the drag characteristics of oil shale more strongly than for coal, owing to the flake-like shape of oil shale. 38 figs., 5 tabs.

Kale, S.R.

1987-10-01T23:59:59.000Z

9

ARM - Measurement - Particle size distribution  

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

size distribution size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Particle size distribution The number of particles present in any given volume of air within a specified size range. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer TDMA : Tandem Differential Mobility Analyzer UHSAS : Ultra-High Sensitivity Aerosol Spectrometer Field Campaign Instruments

10

Particle size distribution instrument. Topical report 13  

DOE Green Energy (OSTI)

The development of an instrument to measure the concentration of particles in gas is described in this report. An in situ instrument was designed and constructed which sizes individual particles and counts the number of occurrences for several size classes. Although this instrument was designed to detect the size distribution of slag and seed particles generated at an experimental coal-fired magnetohydrodynamic power facility, it can be used as a nonintrusive diagnostic tool for other hostile industrial processes involving the formation and growth of particulates. Two of the techniques developed are extensions of the widely used crossed beam velocimeter, providing simultaneous measurement of the size distribution and velocity of articles.

Okhuysen, W.; Gassaway, J.D.

1995-04-01T23:59:59.000Z

11

ARM - Measurement - Aerosol particle size distribution  

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

particle size distribution particle size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol particle size distribution The number of aerosol particles present in any given volume of air within a specificied size range Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments SMPS : Scanning mobility particle sizer TDMA : Tandem Differential Mobility Analyzer UHSAS : Ultra-High Sensitivity Aerosol Spectrometer Field Campaign Instruments

12

ARM - Measurement - Cloud particle size distribution  

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

size distribution size distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud particle size distribution The number of cloud particles present in any given volume of air within a specified size range, including liquid and ice. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments WSACR : Scanning ARM Cloud Radar, tuned to W-Band (95GHz) Field Campaign Instruments CPI : Cloud Particle Imager CLDAEROSMICRO : Cloud and Aerosol Microphysical Properties

13

Physicochemical Characterization of Capstone Depleted Uranium Aerosols II: Particle Size Distributions as a Function of Time  

SciTech Connect

The Capstone Depleted Uranium (DU) Aerosol Study, which generated and characterized aerosols containing depleted uranium from perforation of armored vehicles with large-caliber DU penetrators, incorporated a sampling protocol to evaluated particle size distributions. Aerosol particle size distribution is an important parameter that influences aerosol transport and deposition processes as well as the dosimetry of the inhaled particles. These aerosols were collected on cascade impactor substrates using a pre-established time sequence following the firing event to analyze the uranium concentration and particle size of the aerosols as a function of time. The impactor substrates were analyzed using beta spectrometry, and the derived uranium content of each served as input to the evaluation of particle size distributions. Activity median aerodynamic diameters (AMADs) of the particle size distributions were evaluated using unimodal and bimodal models. The particle size data from the impactor measurements was quite variable. Most size distributions measured in the test based on activity had bimodal size distributions with a small particle size mode in the range of between 0.2 and 1.2 um and a large size mode between 2 and 15 um. In general, the evolution of particle size over time showed an overall decrease of average particle size from AMADs of 5 to 10 um shortly after perforation to around 1 um at the end of the 2-hr sampling period. The AMADs generally decreased over time because of settling. Additionally, the median diameter of the larger size mode decreased with time. These results were used to estimate the dosimetry of inhaled DU particles.

Cheng, Yung-Sung; Kenoyer, Judson L.; Guilmette, Raymond A.; Parkhurst, MaryAnn

2009-03-01T23:59:59.000Z

14

Effect of Coke Particle Size on Sinter Quality  

Science Conference Proceedings (OSTI)

Abstract Scope, The effect of different Coke particle size on sinter quality has been investigated. Eight different coke particle sizes were chosen and sinter ...

15

Method for determining aerosol particle size, device for determining aerosol particle size  

DOE Patents (OSTI)

A method for determining the mass median diameter D of particles contained in a fluid is provided wherein the data of the mass of a pre-exposed and then a post-exposed filter is mathematically combined with data concerning the pressure differential across the same filter before and then after exposure to a particle-laden stream. A device for measuring particle size is also provided wherein the device utilizes the above-method for mathematically combining the easily quantifiable data.

Novick, Vincent J.

1997-12-01T23:59:59.000Z

16

Method for determining aerosol particle size, device for determining aerosol particle size  

DOE Patents (OSTI)

A method for determining the mass median diameter D of particles contained in a fluid is provided wherein the data of the mass of a pre-exposed and then a post-exposed filter is mathematically combined with data concerning the pressure differential across the same filter before and then after exposure to a particle-laden stream. A device for measuring particle size is also provided wherein the device utilizes the above-method for mathematically combining the easily quantifiable data. 2 figs.

Novick, V.J.

1998-10-06T23:59:59.000Z

17

Effect of Coke particle size on sinter quality  

Science Conference Proceedings (OSTI)

Meeting, 2011 TMS Annual Meeting & Exhibition. Symposium, EMPMD Technical Division Student Poster Contest. Presentation Title, Effect of Coke particle size ...

18

Preliminary Investigations of the Effect of Particle Size and Tip Size ...  

Science Conference Proceedings (OSTI)

Presentation Title, Preliminary Investigations of the Effect of Particle Size and Tip Size in the Current Activated Tip-Based Sintering (CATS) of Nickel Powder ...

19

Direct Characterization of Airborne Particles Associated with Arsenic-rich Mine Tailings: Particle Size Mineralogy and Texture  

SciTech Connect

Windblown and vehicle-raised dust from unvegetated mine tailings can be a human health risk. Airborne particles from As-rich abandoned Au mine tailings from Nova Scotia, Canada have been characterized in terms of particle size, As concentration, As oxidation state, mineral species and texture. Samples were collected in seven aerodynamically fractionated size ranges (0.5-16 {micro}m) using a cascade impactor deployed at three tailings fields. All three sites are used for recreational activities and off-road vehicles were racing on the tailings at two mines during sample collection. Total concentrations of As in the <8 {micro}m fraction varied from 65 to 1040 ng/m{sup 3} of air as measured by proton-induced X-ray emission (PIXE) analysis. The same samples were analysed by synchrotron-based microfocused X-ray absorption near-edge spectroscopy ({micro}XANES) and X-ray diffraction ({micro}XRD) and found to contain multiple As-bearing mineral species, including Fe-As weathering products. The As species present in the dust were similar to those observed in the near-surface tailings. The action of vehicles on the tailings surface may disaggregate material cemented with Fe arsenate and contribute additional fine-grained As-rich particles to airborne dust. Results from this study can be used to help assess the potential human health risks associated with exposure to airborne particles from mine tailings.

M Corriveau; H Jamieson; M Parsons; J Campbell; A Lanzirotti

2011-12-31T23:59:59.000Z

20

Particle Size Effects on the Morphology and Bioactivity of Flame ...  

Science Conference Proceedings (OSTI)

Flame spraying was used to manufacture coatings with different levels of porosity by altering both the deposition conditions and the feedstock particle size ...

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Influence of Powder Particle Size Distribution and Pressure on the ...  

Science Conference Proceedings (OSTI)

during HIP were determined as a function of applied pressure, temperature and initial powder particle size distribution for the nickel base superalloy. RENE 95.

22

Particle Size Distribution Model for Leaching Kinetics of Alumina  

Science Conference Proceedings (OSTI)

Presentation Title, Particle Size Distribution Model for Leaching Kinetics of Alumina. Author(s), Li Bao, Ting-an Zhang, Weimin Long, Anh V Nguyen, Guozhi Lv, ...

23

Alpha spectrometric characterization of process-related particle size distributions from active particle sampling at the Los Alamos National Laboratory uranium foundry  

SciTech Connect

Uranium particles within the respirable size range pose a significant hazard to the health and safety of workers. Significant differences in the deposition and incorporation patterns of aerosols within the respirable range can be identified and integrated into sophisticated health physics models. Data characterizing the uranium particle size distribution resulting from specific foundry-related processes are needed. Using personal air sampling cascade impactors, particles collected from several foundry processes were sorted by activity median aerodynamic diameter onto various Marple substrates. After an initial gravimetric assessment of each impactor stage, the substrates were analyzed by alpha spectrometry to determine the uranium content of each stage. Alpha spectrometry provides rapid nondestructive isotopic data that can distinguish process uranium from natural sources and the degree of uranium contribution to the total accumulated particle load. In addition, the particle size bins utilized by the impactors provide adequate resolution to determine if a process particle size distribution is: lognormal, bimodal, or trimodal. Data on process uranium particle size values and distributions facilitate the development of more sophisticated and accurate models for internal dosimetry, resulting in an improved understanding of foundry worker health and safety.

Plionis, Alexander A [Los Alamos National Laboratory; Peterson, Dominic S [Los Alamos National Laboratory; Tandon, Lav [Los Alamos National Laboratory; Lamont, Stephen P [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

24

Crushed Coal Particle Size Distribution Monitoring  

Science Conference Proceedings (OSTI)

This report summarizes an evaluation of different commercially available technologies for on-line monitoring of crushed coal size distribution with a subsequent laboratory test of the most promising system. The technology evaluation focused on image-based approaches for evaluating crushed coal size distribution that would address previous challenges encountered, including depth of field, image scale dependency upon the distance of the sample from the lens, image shadows caused by perimeter lighting, ...

2013-09-11T23:59:59.000Z

25

Particle impact damping: influence of material and size  

E-Print Network (OSTI)

In this study, particle impact damping is measured for a cantilever beam with a particle-filled enclosure attached to its free end. Many particle materials are tested: lead spheres, steel spheres, glass spheres, tungsten carbide pellets, lead dust, steel dust, and sand. The effects of particle size are also investigated. Particle diameters are varied from about 0.2 mm to 3 mm. The experimental data collected is offered as a resourceful database for future development of an analytical model of particle impact damping.

Marhadi, Kun Saptohartyadi

2003-12-01T23:59:59.000Z

26

Microsoft Word - Nano-sized Ion Exchange Particles.docx  

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

Reducing Ion Exchange Particles to Nano-Size Shows Big Potential Reducing Ion Exchange Particles to Nano-Size Shows Big Potential AIKEN, S.C. (January 30, 2012) - Sometimes bigger isn't better. Researchers at the U.S. Department of Energy's Savannah River National Laboratory have successfully shown that they can replace useful little particles of monosodium titanate (MST) with even tinier nano-sized particles, making them even more useful for a variety of applications. MST is an ion exchange material used to decontaminate radioactive and industrial wastewater solutions, and has been shown to be an effective way to deliver metals into living cells for some types of medical treatment. Typically, MST, and a modified form known as mMST developed by SRNL and Sandia National Laboratories, are in the form of fine powders, spherically-shaped particles about 1 to 10 microns in diameter

27

Particle-Size-Distribution of Nevada Test Site Soils  

SciTech Connect

The amount of each size particle in a given soil is called the particle-size distribution (PSD), and the way it feels to the touch is called the soil texture. Sand, silt, and clay are the three particle sizes of mineral material found in soils. Sand is the largest sized particle and it feels gritty; silt is medium sized and it feels floury; and clay is the smallest and if feels sticky. Knowing the particle-size distribution of a soil sample helps to understand many soil properties such as how much water, heat, and nutrients the soil will hold, how fast water and heat will move through the soil, and what kind of structure, bulk density and consistence the soil will have. Furthermore, the native particle-size distribution of the soil in the vicinity of ground zero of a nuclear detonation plays a major role in nuclear fallout. For soils that have a high-sand content, the near-range fallout will be relatively high and the far-range fallout will be relatively light. Whereas, for soils that have a high-silt and high-clay content, the near-range fallout will be significantly lower and the far-range fallout will be significantly higher. As part of a program funded by the Defense Threat Reduction Agency (DTRA), the Lawrence Livermore National Laboratory (LLNL) has recently measured the PSDs from the various major areas at the Nevada Test Site where atmospheric detonations and/or nuclear weapon safety tests were performed back in the 50s and 60s. The purpose of this report is to document those results.

Spriggs, G; Ray-Maitra, A

2007-09-17T23:59:59.000Z

28

Influence of Particle Size Distribution on Random Close Packing  

E-Print Network (OSTI)

The densest amorphous packing of rigid particles is known as random close packing. It has long been appreciated that higher densities are achieved by using collections of particles with a variety of sizes. The variety of sizes is often quantified by the polydispersity of the particle size distribution: the standard deviation of the radius divided by the mean radius. Several prior studies quantified the increase of the packing density as a function of polydispersity. Of course, a particle size distribution is also characterized by its skewness, kurtosis, and higher moments, but the influence of these parameters has not been carefully quantified before. In this work, we numerically generate many packings with different particle radii distributions, varying polydispersity and skewness independently of one another. We find two significant results. First, the skewness can have a significant effect on the packing density and in some cases can have a larger effect than polydispersity. Second, the packing fraction is relatively insensitive to the value of the kurtosis. We present a simple empirical formula for the value of the random close packing density as a function of polydispersity and skewness.

Kenneth W. Desmond; Eric R. Weeks

2013-03-19T23:59:59.000Z

29

Current Development Status of a Particle Size Analyzer for Coated Particle Fuel  

Science Conference Proceedings (OSTI)

Work was performed to develop a prototype Particle Size Analyzer (PSA) for application to coated particle fuel characterization. This system was based on a light obscuration method and targeted towards high throughput analysis. Although never matured to the point of replacing existing lower throughput optical microscopy shadowgraph methods, the system was successfully applied to automating the counting of large particle samples for increased accuracy in calculating mean particle properties based on measurements of multiparticle samples. The measurement of particle size with the PSA was compared to current shadowgraph techniques and found to result in considerably greater throughput at the cost of larger measurement uncertainty. The current algorithm used by the PSA is more sensitive to particle shape and this is a likely cause of the greater uncertainty when attempting to measure average particle diameter. The use of the PSA to measure particle shape will require further development. Particle transport through the PSA and stability of the light source/detector are key elements in the successful application of this technique. A number of system pitfalls were studied and addressed.

Nelson, Andrew T [ORNL; Hunn, John D [ORNL; Karnowski, Thomas Paul [ORNL

2007-08-01T23:59:59.000Z

30

A Laboratory Method for Ash Particle Size Determination  

Science Conference Proceedings (OSTI)

Increasing stringent particulate emissions limits are putting more pressure on power producers to improve electrostatic precipitator (ESP) performance. In an effort to select the most cost effective upgrade option, many power plant engineers are using ESP computer models to estimate the impact of the available options. These models are sensitive to the fly ash particle size distribution used in the calculations, but the actual distribution is rarely known. Furthermore, measuring this distribution has, in...

2005-03-23T23:59:59.000Z

31

Electronic and Geometric Structures of Small Gold Metal Particles: Particles Size Effects and the Relationship to Catalytic Activity  

SciTech Connect

The structure of supported gold nano-particles is affected by the size of the particles. Smaller metal particles have decreased gold - gold bond lengths, a higher d electron count, and have a more reactive d band. The influence of support is negligible compared to that of particle size.

Bokhoven, Jeroen A. van [Institute for chemical and Bioengineering, ETH Zurich (Switzerland); Miller, Jeffrey T. [BP Research Center, Naperville, IL 60565-8406 (United States)

2007-02-02T23:59:59.000Z

32

Deliquescence properties and particle size change of hygroscopic aerosols  

DOE Green Energy (OSTI)

Ambient aerosols frequently contain large proportions of hygroscopic inorganic salts such as sulfates and nitrates, which may induce adverse health effects upon inhalation. The inhaled salt particles are invariably exposed to a humid environment; their deposition along the respiratory tract will necessarily depend upon the size change resulting from water vapor condensation. This paper discusses the deliquescent properties of pure and mixed salt aerosols and the particle size change as a function of relative humidity. Experimental results are presented for the growth of mixed chlorides (NaCl-KCl), mixed sulfates (H{sub 2}SO{sub 4}-(NH{sub 4}){sub 2}SO{sub 4}), and mixed (NH/sub 4/){sub 2}SOsub 4}-NH{sub 4}NO{sub 3} aerosol systems. It is shown that the behavior of the mixed salt aerosols in a moist atmosphere can be predicted from phase diagrams and pertinent thermodynamic properties of the bulk solutions. The evaporation of a saline droplet in an atmosphere of decreasing humidities is also investigated experimentally. For each deliquescent salt aerosol, there is a threshold humidity below which the solution droplets will quickly evaporate to become crystalline particles. The information is useful in the selection of a suitable humidification procedure to generate test aerosols for exposure studies.

Tang, I.N.

1979-01-01T23:59:59.000Z

33

Size based separation of submicron nonmagnetic particles through magnetophoresis in structured obstacle arrays  

E-Print Network (OSTI)

The focus of this work was on developing a novel scalable size based separation technology for nonmagnetic particles in the submicron size range utilizing magnetophoretic forces. When a nonmagnetic particle is immersed in ...

Annavarapu, V. N. Ravikanth (Venkata Nagandra Ravikanth)

2010-01-01T23:59:59.000Z

34

Effect of particle size on the carrier-distillation analysis of PuO$sub 2$  

SciTech Connect

A study was made to determine the effect of particle size on the carrier- distillation analysis of PuO/sub 2/ and to explain how to avoid the difficulties caused by large PuO/sub 2/ particles. The relative intensity of five elements was determined for three particle sizes and it was shown that it increases as the particle size becomes smaller. Further the line intensity of the added internal standard Co also increased with decreasing particle size. Accurate spectrochemical results were obtained when the PuO/sub 2/ particle size was reduced to 45 mu m or less. (JSR)

Martell, C.J.

1974-01-01T23:59:59.000Z

35

Evaluation of Measurements of Particle Size and Sample Area from Optical Array Probes  

Science Conference Proceedings (OSTI)

The technique of using shadow images of particles, obtained in coherent illumination to measure particle size, is analyzed. The theory of Fresnel diffraction for an opaque disc was used to analyze shadow images of transparent spherical particles. ...

A. V. Korolev; S. V. Kuznetsov; Yu E. Makarov; V. S. Novikov

1991-08-01T23:59:59.000Z

36

Background dust emission following grassland fire: a snapshot across the particle-size spectrum highlights how high-resolution measurements enhance detection  

SciTech Connect

Dust emission rates vary temporally and with particle size. Many studies of dust emission focus on a particular temporal scale and the portion of the particle-size spectrum associated with a single instrument; fewer studies have assessed dust emission across the particle-size spectrum and associated temporal scales using multiple instruments. Particularly lacking are measurements following disturbances such as fire that are high-resolution and focused on finer particles - those with direct implications for human health and potential for long-distance biogeochemical transport - during less windy but more commonly occurring background conditions. We measured dust emissions in unburned and burned semiarid grassland using four different instruments spanning different combinations of temporal resolution and particle-size spectrum: Big Springs Number Eight (BSNE) and Sensit instruments for larger saltating particles, DustTrak instruments for smaller suspended particles, and Total Suspended Particulate (TSP) samplers for measuring the entire range of particle sizes. Unburned and burned sites differed in vegetation cover and aerodynamic roughness, yet surprisingly differences in dust emission rates were only detectable for saltation using BSNE and for smaller aerosols using DustTrak. Our results, surprising in the lack of consistently detected differences, indicate that high-resolution DustTrak measurements offered the greatest promise for detecting differences in background emission rates and that BSNE samplers, which integrate across height, were effective for longer intervals. More generally, our results suggest that interplay between particle size, temporal resolution, and integration across time and height can be complex and may need to be considered more explicitly for effective sampling for background dust emissions.

Whicker, Jeffrey J [Los Alamos National Laboratory; Martin, Luis M [UNIV OF ARIZONA; Field, Jason P [UNIV OF ARIZONA; Villegas, Juan C [UNIV OF ARIZONA; Brehsears, David D [UNIV OF ARIZONA; Law, Darin J [UNIV OF ARIZONA; Urgeghe, Anna M [UNIV OF ARIZONA

2009-01-01T23:59:59.000Z

37

The Use of Direct Observations over the Aerosol Particle Size Distribution for Inverting Lidar Data  

Science Conference Proceedings (OSTI)

The work is concerned with the inversion of horizontal lidar data into the aerosol particle size distribution (APSD). The aerosol is assumed to consist of spherical particles of continental and oceanic origin. The particular refraction index is ...

Kusiel S. Shifrin; Ilia G. Zolotov

2003-10-01T23:59:59.000Z

38

The Modified Gamma Size Distribution Applied to Inhomogeneous and Nonspherical Particles: Key Relationships and Conversions  

Science Conference Proceedings (OSTI)

The four-parameter modified gamma distribution (MGD) is the most general mathematically convenient model for size distributions of particle types ranging from aerosols and cloud droplets or ice particles to liquid and frozen precipitation. The ...

Grant W. Petty; Wei Huang

2011-07-01T23:59:59.000Z

39

Compilation and Integration of K Basin Sludge Particle Size Analysis Data  

SciTech Connect

This report consolidates and integrates all of the particle size analysis data generated during the Hanford K Basin sludge characterization campaigns. The provides the most representative particle size distribution curves for the various K Basin sludge types. Understanding the particle size distribution of the sludge is necessary to design sludge retrieval and processing systems and to address sludge transportation and storage safety issues due to the potential reactivity of sludge.

Bredt, Paul R. (BATTELLE (PACIFIC NW LAB)); Tingey, Joel M. (BATTELLE (PACIFIC NW LAB)); Schmidt, Andrew J. (BATTELLE (PACIFIC NW LAB))

2000-11-06T23:59:59.000Z

40

A novel particle tracking method with individual particle size measurement and its application to ordering in glassy hard sphere colloids  

E-Print Network (OSTI)

Particle tracking is a key to single-particle-level confocal microscopy observation of colloidal suspensions, emulsions, and granular matter. The conventional tracking method has not been able to provide accurate information on the size of individual particle. Here we propose a novel method to localise spherical particles of arbitrary relative sizes from either 2D or 3D (confocal) images either in dilute or crowded environment. Moreover this method allows us to estimate the size of each particle reliably. We use this method to analyse local bond orientational ordering in a supercooled polydisperse colloidal suspension as well as the heterogeneous crystallisation induced by a substrate. For the former, we reveal non-trivial couplings of crystal-like bond orientational order and local icosahedral order with the spatial distribution of particle sizes: Crystal-like order tends to form in regions where very small particles are depleted and the slightly smaller size of the central particle stabilizes icosahedral order. For the latter, on the other hand, we found that very small particles are expelled from crystals and accumulated on the growth front of crystals. We emphasize that such information has not been accessible by conventional tracking methods.

Mathieu Leocmach; Hajime Tanaka

2013-01-30T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

In vitro digestibility of starch in sorghum differing in endosperm hardness and flour particle size.  

E-Print Network (OSTI)

??In vitro digestibility of starch in sorghum grains differing in endosperm hardness and flour particle size was assayed by an Englyst resistant starch (RS) method.… (more)

Xu, Xiaoli

2008-01-01T23:59:59.000Z

42

The Effect of Coke Particle Size on Thermal Profile of Sintering ...  

Science Conference Proceedings (OSTI)

Baking process and sinter production was performed for different ranges of coke particle size while other parameter like, iron ore, lime and sintering mixture ...

43

The Sensitivity of Microwave Remote Sensing Observations of Precipitation to Ice Particle Size Distributions  

Science Conference Proceedings (OSTI)

This study investigates the effect of variable size distribution and density of precipitation ice particles on microwave brightness temperatures. For this purpose, a set of self-consistent relationships among rain rate, size parameters of an ...

Ralf Bennartz; Grant W. Petty

2001-03-01T23:59:59.000Z

44

Method for preparing spherical thermoplastic particles of uniform size  

DOE Patents (OSTI)

Spherical particles of thermoplastic material of virtually uniform roundness and diameter are prepared by cutting monofilaments of a selected diameter into rod-like segments of a selected uniform length which are then heated in a viscous liquid to effect the formation of the spherical particles.

Day, J.R.

1975-11-17T23:59:59.000Z

45

Remote Sensing of Cirrus Particle Size Vertical Profile Using...  

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

and shapes. The vertical variation of ice crystal size can alter the radiative heatingcooling profiles in cirrus cloudy atmospheres and hence is an important component in the...

46

The Role of Ice Particle Shapes and Size Distributions in the Single Scattering Properties of Cirrus Clouds  

Science Conference Proceedings (OSTI)

The roles of ice particle size distributions (SDs) and particle shapes in cirrus cloud solar radiative transfer are investigated by analyzing SDs obtained from optical array probe measurements (particle sizes larger than 20–40 ?m) during ...

Andreas Macke; Peter N. Francis; Greg M. McFarquhar; Stefan Kinne

1998-09-01T23:59:59.000Z

47

Mathematical model parameters for describing the particle size spectra of knife-milled corn stover  

Science Conference Proceedings (OSTI)

Particle size distributions of Corn stover (Zea mays L.) created by a knife mill were determined using integral classifying screens with sizes from 12.7 to 50.8 mm, operating at speeds from 250 to 500 rpm, and mass input rates ranging from 1 to 9 kg min_1. Particle distributions were classified using American Society of Agricultural and Biological Engineers (ASABE) standardised sieves for forage analysis that incorporated a horizontal sieving motion. The sieves were made from machined-aluminium with their thickness proportional to the sieve opening dimensions. A wide range of analytical descriptors that could be used to mathematically represent the range of particle sizes in the distributions were examined. The correlation coefficients between geometric mean length and screen size, feed rate, and speed were 0.980, 0.612, and _0.027, respectively. Screen size and feed rate directly influenced particle size, whereas operating speed had a weak indirect relation with particle size. The Rosin Rammler equation fitted the chopped corn stover size distribution data with coefficient of determination (R2) > 0.978. This indicated that particle size distribution of corn stover was well-fit by the Rosin Rammler function. This can be attributed to the fact that Rosin Rammler expression was well suited to the skewed distribution of particle sizes. Skewed distributions occurred when significant quantities of particles, either finer or coarser, existed or were removed from region of the predominant size. The mass relative span was slightly greater than 1, which indicated that it was a borderline narrow to wide distribution of particle sizes. The uniformity coefficient was corn stover produced fine-skewed mesokurtic particles with 12.7 50.8 mm screens. Size-related parameters, namely, geometric mean length, Rosin Rammler size parameter, median length, effective length, and size guide number, were well predicted at R2 values of 0.981, 0.982, 0.979, 0.950 and 0.978, respectively as a function of knife mill screen size, feed rate, and speed. Results of this analysis of particle sizes could be applied to the selection of knife mill operating parameters to produce a particular size of corn stover chop, and could serve as a guide for the relationships among various analytic descriptors of biomass particle distributions.

Bitra, V.S.P [University of Tennessee; Womac, A.R. [University of Tennessee; Yang, Y.T. [University of Tennessee; Miu, P.I. [University of Tennessee; Igathanathane, C. [Mississippi State University (MSU)

2009-09-01T23:59:59.000Z

48

EFFECTS OF SAMPLE SIZE ON CHARACTERIZATION OF WOOD-PARTICLE LENGTH DISTRIBUTION  

E-Print Network (OSTI)

EFFECTS OF SAMPLE SIZE ON CHARACTERIZATION OF WOOD-PARTICLE LENGTH DISTRIBUTION Quang V. Cao of sample size on fitting length distribution of wood particles used for manufacturing wood-based composites moments and the ability of the sample distributions to characterize the population represented

49

Sieveless particle size distribution analysis of particulate materials through computer vision  

Science Conference Proceedings (OSTI)

This paper explores the inconsistency of ''length-based separation'' by mechanical sieving of particulate materials with standard sieves, which is the standard method of particle size distribution (PSD) analysis. We observed inconsistencies of length-based ... Keywords: Biomass sieve analysis, Dimension, Image processing, ImageJ plugin, Particle size distribution, Physical property

C. Igathinathane; L. O. Pordesimo; E. P. Columbus; W. D. Batchelor; S. Sokhansanj

2009-05-01T23:59:59.000Z

50

A study on the effect of particle size on coal flotation kinetics using fuzzy logic  

Science Conference Proceedings (OSTI)

This paper investigates the effect of particle size on the flotation kinetics of coal in a batch flotation cell. The relationship between flotation kinetics constant and theoretical flotation recovery with particle size was estimated with nonlinear equations. ... Keywords: Coal, Flotation kinetics, Fuzzy logic, Modeling

Emad Abkhoshk; Mohammad Kor; Bahram Rezai

2010-07-01T23:59:59.000Z

51

Particle Size Changes in Rumens of Cattle Grazing Kansas Flint Hills Range  

E-Print Network (OSTI)

Particle Size Changes in Rumens of Cattle Grazing Kansas Flint Hills Range J.R. FORWOOD, C.E. OWENSBY, AND G. TOWNE Abstract A ruminally fistulated Hereford steer and heifer grazing Kansas Flint Hills particle size changes in rumens of cattle grazing native Kansas Flint Hills range forage. Materials

Owensby, Clenton E.

52

Particle size distributions of ground corn and DDGS from dry grind processing  

E-Print Network (OSTI)

ABSTRACT. Ethanol production has increased in the past decade as a result of growth in the dry grind industry. In the dry grind process, the first step is grinding of corn. The particle size of the resulting ground corn can affect the fermentation process and the particle size of dried distillers ’ grains with solubles (DDGS), a coproduct of dry grind processing. Few data are available that characterize particle size distributions of ground corn or DDGS. The objective was to determine particle size distributions of ground corn and DDGS. Samples of ground corn and DDGS were obtained from nine dry grind plants; particle size distribution, geometric mean diameter (dgw) and geometric standard deviation (Sgw) were determined. The dgw of ground corn and of DDGS were not different among processing plants. The overall mean dgw of ground corn was not different from that of DDGS. Most of the ground corn (80 g/100 g) and DDGS (70 g/100 g) were recovered in the three largest particle size categories. The particle size distributions of ground corn were not correlated (r Corn, DDGS, Distillers dried grains with solubles, Ethanol. Corn is processed into ethanol by one of two major processes: dry grinding or wet milling. Wet milling is more complex than dry grinding because fiber and germ components are separated; this requires considerable equipment and capital. In the dry grind process,

K. D. Rausch; R. L. Belyea; M. R. Ellersieck; V. Singh; D. B. Johnston; M. E. Tumbleson

2005-01-01T23:59:59.000Z

53

Aerosols and Ice Particle Size in Tropical Cumulonimbus  

Science Conference Proceedings (OSTI)

A retrieval of ice crystal size near the tops of active deep cumulonimbus clouds (Cb) throughout the Tropics over a 12-yr period is presented based on radiances from the 3.7-?m channel of the Advanced Very High Resolution Radiometer (AVHRR). ...

Steven C. Sherwood

2002-05-01T23:59:59.000Z

54

Size-Resolved Particle Number and Volume Emission Factors for On-Road  

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

Size-Resolved Particle Number and Volume Emission Factors for On-Road Size-Resolved Particle Number and Volume Emission Factors for On-Road Gasoline and Diesel Motor Vehicles Title Size-Resolved Particle Number and Volume Emission Factors for On-Road Gasoline and Diesel Motor Vehicles Publication Type Journal Article Year of Publication 2009 Authors Ban-Weiss, George, Melissa M. Lunden, Thomas W. Kirchstetter, and Robert A. Harley Journal Journal of Aerosol Science Keywords emission, motor vehicle, particle number, size distribution, tunnel Abstract Average particle number concentrations and size distributions from ~61 000 light-duty (LD) vehicles and ~2500 medium-duty (MD) and heavy-duty (HD) trucks were measured during the summer of 2006 in a San Francisco Bay area traffic tunnel. One of the traffic bores contained only LD vehicles, and the other contained mixed traffic, allowing pollutants to be apportioned between LD vehicles and diesel trucks. Particle number emission factors (particle diameter Dp > 3 nm) were found to be (3.9 ± 1.4) x 1014 and (3.3 ± 1.3) x 1015 # kg-1 fuel burned for LD vehicles and diesel trucks, respectively. Size distribution measurements showed that diesel trucks emitted at least an order of magnitude more particles for all measured sizes (10 < Dp < 290 nm) per unit mass of fuel burned. The relative importance of LD vehicles as a source of particles increased as Dp decreased. Comparing the results from this study to previous measurements at the same site showed that particle number emission factors have decreased for both LD vehicles and diesel trucks since 1997. Integrating size distributions with a volume weighting

55

Influence of Particle Size on Reaction Selectivity in Cyclohexene Hydrogenation and Dehydrogenation over Silica-Supported Monodisperse Pt Particles  

DOE Green Energy (OSTI)

The role of particle size during the hydrogenation/dehydrogenation of cyclohexene (10 Torr C{sub 6}H{sub 10}, 200-600 Torr H{sub 2}, and 273-650 K) was studied over a series of monodisperse Pt/SBA-15 catalysts. The conversion of cyclohexene in the presence of excess H{sub 2} (H{sub 2}:C{sub 6}H{sub 10} ratio = 20-60) is characterized by three regimes: hydrogenation of cyclohexene to cyclohexane at low temperature (< 423 K), an intermediate temperature range in which both hydrogenation and dehydrogenation occur; and a high temperature regime in which the dehydrogenation of cyclohexene dominates (> 573 K). The rate of both reactions demonstrated maxima with temperature, regardless of Pt particle size. For the hydrogenation of cyclohexene, a non-Arrhenius temperature dependence (apparent negative activation energy) was observed. Hydrogenation is structure insensitive at low temperatures, and apparently structure sensitive in the non-Arrhenius regime; the origin of the particle-size dependent reactivity with temperature is attributed to a change in the coverage of reactive hydrogen. Small particles were more active for dehydrogenation and had lower apparent activation energies than large particles. The selectivity can be controlled by changing the particle size, which is attributed to the structure sensitivity of both reactions in the temperature regime where hydrogenation and dehydrogenation are catalyzed simultaneously.

Rioux, R. M.; Hsu, B. B.; Grass, M. E.; Song, H.; Somorjai, Gabor A.

2008-07-11T23:59:59.000Z

56

Aerodynamic Contrails: Microphysics and Optical Properties  

Science Conference Proceedings (OSTI)

Aerodynamic contrails form when air flows across the wings of subsonic aircraft in cruise. During a short adiabatic expansion phase, high supersaturations trigger burstlike homogeneous ice formation on ambient liquid aerosol particles within a ...

B. Kärcher; B. Mayer; K. Gierens; U. Burkhardt; H. Mannstein; R. Chatterjee

2009-02-01T23:59:59.000Z

57

SIZE DISTRIBUTIONS OF SOLAR FLARES AND SOLAR ENERGETIC PARTICLE EVENTS  

Science Conference Proceedings (OSTI)

We suggest that the flatter size distribution of solar energetic proton (SEP) events relative to that of flare soft X-ray (SXR) events is primarily due to the fact that SEP flares are an energetic subset of all flares. Flares associated with gradual SEP events are characteristically accompanied by fast ({>=}1000 km s{sup -1}) coronal mass ejections (CMEs) that drive coronal/interplanetary shock waves. For the 1996-2005 interval, the slopes ({alpha} values) of power-law size distributions of the peak 1-8 A fluxes of SXR flares associated with (a) >10 MeV SEP events (with peak fluxes {>=}1 pr cm{sup -2} s{sup -1} sr{sup -1}) and (b) fast CMEs were {approx}1.3-1.4 compared to {approx}1.2 for the peak proton fluxes of >10 MeV SEP events and {approx}2 for the peak 1-8 A fluxes of all SXR flares. The difference of {approx}0.15 between the slopes of the distributions of SEP events and SEP SXR flares is consistent with the observed variation of SEP event peak flux with SXR peak flux.

Cliver, E. W. [Space Vehicles Directorate, Air Force Research Laboratory, Sunspot, NM 88349 (United States); Ling, A. G. [Atmospheric Environmental Research, Lexington, MA 02421 (United States); Belov, A. [IZMIRAN, Troitsk, Moscow Region 142190 (Russian Federation); Yashiro, S. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-10T23:59:59.000Z

58

Effect of different support morphologies and pt particle sizes in electrocatalysts for fuel cell applications  

Science Conference Proceedings (OSTI)

The performance of a low temperature fuel cell is strongly correlated with parameters like the platinum particle size, platinum dispersion on the carbon support, and electronic and protonic conductivity in the catalyst layer as well as its porosity. ...

G. Sevjidsuren; S. Zils; S. Kaserer; A. Wolz; F. Ettingshausen; D. Dixon; A. Schoekel; C. Roth; P. Altantsog; D. Sangaa; Ch. Ganzorig

2010-01-01T23:59:59.000Z

59

A Study of Cirrus Ice Particle Size Distribution Using TC4 Observations  

Science Conference Proceedings (OSTI)

An analysis of two days of in situ observations of ice particle size spectra, in convectively generated cirrus, obtained during NASA’s Tropical Composition, Cloud, and Climate Coupling (TC4) mission is presented. The observed spectra are examined ...

Lin Tian; Gerald M. Heymsfield; Lihua Li; Andrew J. Heymsfield; Aaron Bansemer; Cynthia H. Twohy; Ramesh C. Srivastava

2010-01-01T23:59:59.000Z

60

Thermal conductivity of fluids containing suspension of nanometer-sized particles  

E-Print Network (OSTI)

Nanofluids, which are fluids containing suspension of nanometer-sized particles, have been reported to possess substantially higher thermal conductivity than their respective base fluids. This thesis reports on an experimental ...

Ma, Jack Jeinhao

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Remote Sensing of Cirrus Cloud Particle Size and Optical Depth Using Polarimetric Sensor Measurements  

Science Conference Proceedings (OSTI)

This paper presents a conceptual approach toward the remote sensing of cirrus cloud particle size and optical depth using the degree of polarization and polarized reflectance associated with the first three Stokes parameters, I, Q, and U, for the ...

S. C. Ou; K. N. Liou; Y. Takano; R. L. Slonaker

2005-12-01T23:59:59.000Z

62

System size dependence of particle production at the SPS  

SciTech Connect

Recent results on the system size dependence of net-baryon and hyperon production as measured at the CERN SPS are discussed. The observed N{sub part} dependences of yields, but also of dynamical properties, such as average transverse momenta, can be described in the context of the core corona approach. Other observables, such as antiproton yields and net-protons at forward rapidities, do not follow the predictions of this model. Possible implications for a search for a critical point in the QCD phase diagram are discussed. Event-by-event fluctuations of the relative core to corona source contributions might influence fluctuation observables (e.g., multiplicity fluctuations). The magnitude of this effect is investigated.

Blume, C., E-mail: blume@ikf.uni-frankfurt.de [J.W. Goethe-Universitaet, Institut fuer Kernphysik (Germany)

2012-05-15T23:59:59.000Z

63

On the clustering of finite-size particles in a turbulent flow  

E-Print Network (OSTI)

We investigate experimentally the spatial distributions of heavy and neutrally buoyant particles of finite size in a fully turbulent flow. As their Stokes number (i.e. ratio of the particle viscous relaxation time to a typical flow time scale) is close to 1, one may expect both classes of particles to aggregate in specific flow regions. This is not observed. Using a Vorono\\"i analysis we show that neutrally buoyant particles sample turbulence homogeneously, whereas heavy particles do cluster. One implication for the understanding and modeling of particle laden flows, is that the Stokes number cannot be the sole key parameter as soon as the dynamics of finite-size objects is considered.

Fiabane, Lionel; Volk, Romain; Pinton, Jean-Francois; Bourgoin, Mickael

2012-01-01T23:59:59.000Z

64

Standard Test Method for Particle Size Distribution of Alumina or Quartz Powders by Electrical Sensing Zone Technique  

E-Print Network (OSTI)

Standard Test Method for Particle Size Distribution of Alumina or Quartz Powders by Electrical Sensing Zone Technique

American Society for Testing and Materials. Philadelphia

1992-01-01T23:59:59.000Z

65

Discrete Particle Swarm Optimization for the Multi-Level Lot-Sizing Problem  

Science Conference Proceedings (OSTI)

This paper presents a Discrete Particle Swarm Optimization (DPSO) approach for the Multi-Level Lot-Sizing Problem (MLLP), which is an uncapacitated lot sizing problem dedicated to materials requirements planning (MRP) systems. The proposed DPSO approach ... Keywords: DPSO, MLLP, MRP, Metaheuristic, Sequential Heuristic

Laurent Deroussi; David Lemoine

2011-01-01T23:59:59.000Z

66

A Balloon-Borne Instrument for Measuring the Charge and Size of Precipitation Particles inside Thunderstorms  

Science Conference Proceedings (OSTI)

A new balloon-borne instrument created by the authors and referred to as the q-d instrument that measures the charge q and size d of precipitation particles is discussed. The instrument measures charge with an induction cylinder size with an ...

Monte G. Bateman; W. David Rust; Thomas C. Marshall

1994-02-01T23:59:59.000Z

67

Turbulent particle deposition in a rectangular chamber: Study of the effect of particle size and ventilation regimes  

SciTech Connect

The interaction of aerosol particles with wall surfaces is important in modeling their behavior. This interaction is usually represented in theoretical models as a loss term. The loss rate is the rate at which particles deposit or react with the surfaces. This loss term is important in many branches of aerosol science including human health and indoor air quality. Increased surface deposition usually means lower concentrations of airborne particles and hence, lower exposure to the inhabitants. If the efficiency of the particle deposition is influenced by factors other than the particle size, such as a natural convection of the air, this has to be taken into account to evaluate the results. In this research, test aerosol sized from 15 nm to 3 {micro}m are produced by several different aerosol generators; the gas burner, the Collison nebulizer, the condensation aerosol generator, the orifice atomizer and the Vibrating Orifice Aerosol Generator (VOAG). A rectangular chamber whose dimensions are 75 x 75 x 180 cm{sup 3} was used in this study. The particles were injected into the chamber, with a known ventilation and the concentration decay was monitored by the Ultrafine Condensation Particle Counter (UCPC) and Optical Particle Counter (OPC). During the measurement, the air inside the chamber is moved by natural convection and ventilation effect. The results shows that the particle loss rate under the higher air exchange rate is larger and this is not only due to air exchange itself but also the wall deposition. The theoretical model presented by Benes and Holub (1996) agree with the experimental data better than the Crump and Seinfield (1981) model with the hypothesis of Plandtl`s mixing length. 118 refs.

Nomura, Yoshio

1996-04-01T23:59:59.000Z

68

An Aggregate Model for the Particle Size Distribution in Saturn's Rings  

E-Print Network (OSTI)

Saturn's rings are known to consist of a large number of water ice particles. They form a flat disk, as the result of an interplay of angular momentum conservation and the steady loss of energy in dissipative particle collisions. For particles in the size range from a few centimeters to about a few meters a power law distribution of radii r^(-q), with q = 3, is implied by the light scattering properties of the rings. In contrast, for larger sizes the distribution drops steeply with increasing r. It has been suggested that this size distribution may arise from a balance between aggregation and fragmentation of ring particles, but to date neither the power-law dependence, nor the upper size-cutoff have been explained or quantified within a unique theory. Here we present a new kinetic model for the collisional evolution of the size distribution and show that the exponent q is expected to be constrained to the interval 2.75 < q < 3.5. An exponential cutoff towards larger particle sizes establishes naturally...

Brilliantov, Nikolai; Hayakawa, Hisao; Bodrova, Anna; Spahn, Frank; Schmidt, Juergen

2013-01-01T23:59:59.000Z

69

Electric double layer for spherical particles in salt-free concentrated suspensions including ion size effects  

E-Print Network (OSTI)

The equilibrium electric double layer (EDL) that surrounds the colloidal particles is determinant for the response of a suspension under a variety of static or alternating external fields. An ideal salt-free suspension is composed by the charged colloidal particles and the ionic countercharge released by the charging mechanism. The existing macroscopic theoretical models can be improved by incorporating different ionic effects usually neglected in previous mean-field approaches, which are based on the Poisson-Boltzmann equation (PB). The influence of the finite size of the ions seems to be quite promising because it has been shown to predict phenomena like charge reversal, which has been out of the scope of classical PB approximations. In this work we numerically obtain the surface electric potential and the counterions concentration profiles around a charged particle in a concentrated salt-free suspension corrected by the finite size of the counterions. The results show the large importance of such corrections for moderate to high particle charges at every particle volume fraction, specially, when a region of closest approach of the counterions to the particle surface is considered. We conclude that finite ion size considerations are obeyed for the development of new theoretical models to study nonequilibrium properties in concentrated colloidal suspensions, particularly the salt-free ones with small and highly charged particles.

R. Roa; F. Carrique; E. Ruiz-Reina

2011-02-01T23:59:59.000Z

70

Optimal Sizing of a Stand-alone Wind/Photovoltaic Generation Unit using Particle Swarm Optimization  

Science Conference Proceedings (OSTI)

A hybrid wind/photovoltaic generation system is designed to supply power demand. The aim of this design is minimization of the overall cost of the generation scheme over 20 years of operation. Full demand supply is modeled as constraint for optimization ... Keywords: genetic algorithm, optimal sizing, particle swarm optimization, photovoltaic, wind energy

Ali Kashefi Kaviani; Hamid Reza Baghaee; Gholam Hossein Riahy

2009-02-01T23:59:59.000Z

71

Particle size for greatest penetration of HEPA filters - and their true efficiency  

SciTech Connect

The particle size that most greatly penetrates a filter is a function of filter media construction, aerosol density, and air velocity. In this paper the published results of several experiments are compared with a modern filtration theory that predicts single-fiber efficiency and the particle size of maximum penetration. For high-efficiency particulate air (HEPA) filters used under design conditions this size is calculated to be 0.21 ..mu..m diam. This is in good agreement with the experimental data. The penetration at 0.21 ..mu..m is calculated to be seven times greater than at the 0.3 ..mu..m used for testing HEPA filters. Several mechanisms by which filters may have a lower efficiency in use than when tested are discussed.

da Roza, R.A.

1982-12-01T23:59:59.000Z

72

SURFACE AREA, VOLUME, MASS, AND DENSITY DISTRIBUTIONS FOR SIZED BOMASS PARTICLES  

DOE Green Energy (OSTI)

This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period July 01, 2004 to December 31, 2004 which covers the first six months of the project. Presently work is in progress to characterize surface area, volume, mass, and density distributions for sized biomass particles. During this reporting period, supply requests were processed and supplies including biomass test particles (hardwood sawdust AI14546) in the size range of 100-200 microns were obtained from a cofiring pilot plant research facility owned by Southern Company, Birmingham, AL. Morehouse has completed setting up of the gravimetric technique measurement system in the heat transfer laboratory, department of physics and dual degree engineering, Morehouse College. Simultaneously, REM, our subcontractor, has completed setting up of the electrodynamic balance (EDB) measurement system to characterize shape and mass for individual biomass particles. Testing of the gravimetric system, and calibration of the cameras and imaging systems using known sizes of polystyrene particles are in progress.

Ramanathan Sampath

2004-05-01T23:59:59.000Z

73

Effects of Sludge Particle Size and Density on Hanford Waste Processing  

SciTech Connect

The U.S. Department of Energy Office of River Protection's Waste Treatment and Immobilization Plant (WTP) will process and treat radioactive waste that is stored in tanks at the Hanford Site in southeastern Washington State. Piping and pumps have been selected to transport the high-level waste (HLW) slurries in the WTP. Pipeline critical-velocity calculations for these systems require the input of a bounding particle size and density. Various approaches based on statistical analyses have been used in the past to provide an estimate of this bounding size and density. In this paper, representative particle size and density distributions (PSDDs) of Hanford waste insoluble solids have been developed based on the new approach that relates measured particle size distributions (PSDs) to solid-phase compounds. This work was achieved through extensive review of available Hanford waste PSDs and solid-phase compound data. Composite PSDs representing the waste in up to 19 Hanford waste tanks were developed, and the insoluble solid phase compounds for the 177 Hanford waste tanks, their relative fractions, crystal densities, and particle size and shape were developed. With such a large combination of particle sizes and particle densities, a Monte Carlo simulation approach was used to model the PSDDs. Further detail was added by including an agglomeration of these compounds where the agglomerate density was modeled with a fractal dimension relation. The Monte Carlo simulations were constrained to hold the following relationships: 1) the composite PSDs are reproduced, 2) the solid-phase compound mass fractions are reproduced, 3) the expected in situ bulk-solids density is qualitatively reproduced, and 4) a representative fraction of the sludge volume comprising agglomerates is qualitatively reproduced to typical Hanford waste values. Four PSDDs were developed and evaluated. These four PSDD scenarios correspond to permutations where the master PSD was sonicated or not-sonicated before being analyzed and whether agglomerates existed or not in the PSD samples. When critical pipeline velocity calculations are applied to these results, several percent of Hanford tank waste sludge are expected to exceed pipeline velocities of 4 ft/sec. Operation and waste processing at pipeline velocities in the >4 to 6 ft/sec range appear to be compatible with the Hanford sludge in 3-inch pipes. (authors)

Poloski, A.P.; Wells, B.E.; Mahoney, L.A.; Daniel, R.C.; Tingey, J.M.; Cooley, S.K. [Pacific Northwest National Laboratory, Richland, WA (United States)

2008-07-01T23:59:59.000Z

74

Effects of Sludge Particle Size and Density on Hanford Waste Processing  

SciTech Connect

The U.S. Department of Energy Office of River Protection’s Waste Treatment and Immobilization Plant (WTP) will process and treat radioactive waste that is stored in tanks at the Hanford Site in southeastern Washington State. Piping and pumps have been selected to transport the high-level waste (HLW) slurries in the WTP. Pipeline critical-velocity calculations for these systems require the input of a bounding particle size and density. Various approaches based on statistical analyses have been used in the past to provide an estimate of this bounding size and density. In this paper, representative particle size and density distributions (PSDDs) of Hanford waste insoluble solids have been developed based on a new approach that relates measured particle-size distributions (PSDs) to solid-phase compounds. This work was achieved through extensive review of available Hanford waste PSDs and solid-phase compound data. Composite PSDs representing the waste in up to 19 Hanford waste tanks were developed, and the insoluble solid-phase compounds for the 177 Hanford waste tanks, their relative fractions, crystal densities, and particle size and shape were developed. With such a large combination of particle sizes and particle densities, a Monte Carlo simulation approach was used to model the PSDDs. Further detail was added by including an agglomeration of these compounds where the agglomerate density was modeled with a fractal dimension relation. The Monte Carlo simulations were constrained to hold the following relationships: 1) the composite PSDs are reproduced, 2) the solid-phase compound mass fractions are reproduced, 3) the expected in situ bulk-solids density is qualitatively reproduced, and 4) a representative fraction of the sludge volume comprising agglomerates is qualitatively reproduced to typical Hanford waste values. Four PSDDs were developed and evaluated. These four PSDD scenarios correspond to permutations where the master PSD was sonicated or not-sonicated before being analyzed and whether agglomerates existed or not in the PSD samples. When critical pipeline velocity calculations are applied to these results, several percent of Hanford tank waste sludge are expected to exceed pipeline velocities of <3 to 4 ft/sec. Operation and waste processing at pipeline velocities in the >4 to 6 ft/sec range appear to be compatible with the Hanford sludge in 3-inch pipes.

Poloski, Adam P.; Wells, Beric E.; Mahoney, Lenna A.; Daniel, Richard C.; Tingey, Joel M.; Cooley, Scott K.

2008-02-04T23:59:59.000Z

75

Effects of ice particle size vertical inhomogeneity on the passive remote sensing of ice clouds  

Science Conference Proceedings (OSTI)

The solar reflectance bi-spectral (SRBS) and infrared split-window (IRSpW) methods are two of the most popular techniques for passive ice cloud property retrievals from multispectral imagers. Ice clouds are usually assumed to be vertically homogeneous in global operational algorithms based on these methods, although significant vertical variations of ice particle size are typically observed in ice clouds. In this study we investigate uncertainties in retrieved optical thickness, effective particle size, and ice water path introduced by a homogeneous cloud assumption in both the SRBS and IRSpW methods, and focus on whether the assumption can lead to significant discrepancies between the two methods. The study simulates the upwelling spectral radiance associated with vertically structured clouds and passes the results through representative SRBS and IRSpW retrieval algorithms. Cloud optical thickness is limited to values for which IRSpW retrievals are possible (optical thickness less than about 7). When the ice cloud is optically thin and yet has a significant ice particle size vertical variation, it is found that both methods tend to underestimate the effective radius and ice water path. The reason for the underestimation is the nonlinear dependence of ice particle scattering properties (extinction and single scattering albedo) on the effective radius. Because the nonlinearity effect is stronger in the IRSpW than the SRBS method, the IRSpW-based IWP tends to be smaller than the SRBS counterpart. When the ice cloud is moderately optically thick and ice particle size increases monotonically towards cloud base, the two methods are in qualitative agreement; in the event that ice particle size decreases towards cloud base, the effective radius and ice water path retrievals based on the SRBS method are substantially larger than those from the IRSpW. The main findings of this study suggest that the homogenous cloud assumption can affect the SRBS and IRSpW methods to different extents and, consequently, can lead to significantly different retrievals. Therefore caution should be taken when comparing and combining the ice cloud property retrievals from these two methods.

Zhang, Zhibo; Platnick, Steven; Yang, Ping; Heidinger, Andrew K.; Comstock, Jennifer M.

2010-09-03T23:59:59.000Z

76

SURFACE AREA, VOLUME, MASS, AND DENSITY DISTRIBUTIONS FOR SIZED BIOMASS PARTICLES  

DOE Green Energy (OSTI)

This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period July 01, 2005 to December 31, 2005 which covers the third six months of the project. Presently work is in progress to characterize surface area, volume, mass, and density distributions for sized biomass particles. During this reporting period, Morehouse continued to obtain additional mean mass measurements for biomass particles employing the gravimetric technique measurement system that was set up in the last reporting period. Simultaneously, REM, our subcontractor, has obtained raw data for surface area, volume, and drag coefficient to mass ratio (C{sub d}/m) information for several biomass particles employing the electrodynamic balance (EDB) measurement system that was calibrated in the last reporting period. Preliminary results of the mean mass and the shape data obtained are reported here, and more data collection is in progress.

Ramanathan Sampath

2006-01-01T23:59:59.000Z

77

SURFACE AREA, VOLUME, MASS, AND DENSITY DISTRIBUTIONS FOR SIZED BIOMASS PARTICLES  

DOE Green Energy (OSTI)

This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period January 01, 2006 to June 30, 2006 which covers the fourth six months of the project. Presently work is in progress to characterize surface area, volume, mass, and density distributions for sized biomass particles. During this reporting period, Morehouse completed obtaining additional mean mass measurements for biomass particles employing the gravimetric technique measurement system that was set up in a previous reporting period. Simultaneously, REM, our subcontractor, has completed obtaining raw data for surface area, volume, and drag coefficient to mass ratio (Cd/m) information for 9 more biomass particles employing the electrodynamic balance (EDB) measurement system that was calibrated before in this project. Results of the mean mass data obtained to date are reported here, and analysis of the raw data collected by REM is in progress.

Ramanathan Sampath

2006-06-30T23:59:59.000Z

78

Phase Transformations of Micron-Sized H2SO4/H2O Particles Studied by Infrared Spectroscopy  

E-Print Network (OSTI)

indicate that solid phase forma- tion from STS does not occur until the ice frost point is reached.2Phase Transformations of Micron-Sized H2SO4/H2O Particles Studied by Infrared Spectroscopy Scot T been developed for investigations of phase transitions of micron-sized particles through infrared

79

SIZE AND TEMPERATURE DEPENDENCE IN THE FAR-IR SPECTRA OF WATER ICE PARTICLES  

SciTech Connect

Spectra of water-ice aerosol particles have been measured in the far-IR region using synchrotron radiation. The particles in the nanoscale size regime of 1-100 nm were formed by rapid collisional cooling at temperatures ranging from 4 to 190 K. The spectra show the characteristic bands centered near 44 {mu}m (230 cm{sup -1}) and 62 {mu}m (160 cm{sup -1}) associated with the intermolecular lattice modes of crystalline ice at all temperatures, in contrast to previous studies of thin films formed by vapor deposition where amorphous ice is generated below 140 K. The bands shift to higher wavenumber values as the temperature is reduced, consistent with the trend seen in earlier studies, but in our experiments the actual peak positions in the aerosol particle spectra are consistently higher by ca. 4 cm{sup -1}. This finding has implications for the potential use of these spectral features as a temperature probe. The particle sizes are small enough for their spectra to be free of scattering effects, and therefore provide a means to assess imaginary refractive index values obtained through Kramers-Kronig analyses of thin film spectra.

Medcraft, Chris; McNaughton, Don; Thompson, Chris D. [School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800 (Australia); Appadoo, Dominique [Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168 (Australia); Bauerecker, Sigurd [Institut fuer Physikalische und Theoretische Chemie, Technische Universitaet Braunschweig, Hans-Sommer-Strasse 10, D-38106 Braunschweig (Germany); Robertson, Evan G., E-mail: E.Robertson@latrobe.edu.au [Department of Chemistry and La Trobe Institute of Molecular Sciences, La Trobe University, Bundoora, Victoria 3086 (Australia)

2012-10-10T23:59:59.000Z

80

Improved particle impactor assembly for size selective high volume air sampler  

DOE Patents (OSTI)

Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented apertures of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind, the relatively larger particles and passes through two elongate apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. By appropriate selection of dimensions and the number of inlet apertures air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the inlet apertures, to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks. 6 figs.

Langer, G.

1987-03-23T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

The Size and Scattering Coefficient of Urban Aerosol Particles at Washington, DC as a Function of Relative Humidity  

Science Conference Proceedings (OSTI)

The relative humidity dependence of the size and scattering coefficient of atmospheric aerosol particles was measured at Washington, DC during the period 26–31 July 1979. Particle growth curves (i.e., curves of the ratio r/r0, of particle radius ...

James W. Fitzgerald; William A. Hoppel; Michael A. Vietti

1982-08-01T23:59:59.000Z

82

Nano-sized particles, processes of making, compositions and uses thereof  

DOE Patents (OSTI)

The present invention describes methods for preparing high quality nanoparticles, i.e., metal oxide based nanoparticles of uniform size and monodispersity. The nanoparticles advantageously comprise organic alkyl chain capping groups and are stable in air and in nonpolar solvents. The methods of the invention provide a simple and reproducible procedure for forming transition metal oxide nanocrystals, with yields over 80%. The highly crystalline and monodisperse nanocrystals are obtained directly without further size selection; particle size can be easily and fractionally increased by the methods. The resulting nanoparticles can exhibit magnetic and/or optical properties. These properties result from the methods used to prepare them. Also advantageously, the nanoparticles of this invention are well suited for use in a variety of industrial applications, including cosmetic and pharmaceutical formulations and compositions.

O' Brien, Stephen (New York, NY); Yin, Ming (Los Alamos, NM)

2012-05-22T23:59:59.000Z

83

Sieveless particle size distribution analysis of particulate materials through computer vision  

DOE Green Energy (OSTI)

This paper explores the inconsistency of length-based separation by mechanical sieving of particulate materials with standard sieves, which is the standard method of particle size distribution (PSD) analysis. We observed inconsistencies of length-based separation of particles using standard sieves with manual measurements, which showed deviations of 17 22 times. In addition, we have demonstrated the falling through effect of particles cannot be avoided irrespective of the wall thickness of the sieve. We proposed and utilized a computer vision with image processing as an alternative approach; wherein a user-coded Java ImageJ plugin was developed to evaluate PSD based on length of particles. A regular flatbed scanner acquired digital images of particulate material. The plugin determines particles lengths from Feret's diameter and width from pixel-march method, or minor axis, or the minimum dimension of bounding rectangle utilizing the digital images after assessing the particles area and shape (convex or nonconvex). The plugin also included the determination of several significant dimensions and PSD parameters. Test samples utilized were ground biomass obtained from the first thinning and mature stand of southern pine forest residues, oak hard wood, switchgrass, elephant grass, giant miscanthus, wheat straw, as well as Basmati rice. A sieveless PSD analysis method utilized the true separation of all particles into groups based on their distinct length (419 639 particles based on samples studied), with each group truly represented by their exact length. This approach ensured length-based separation without the inconsistencies observed with mechanical sieving. Image based sieve simulation (developed separately) indicated a significant effect (P < 0.05) on number of sieves used in PSD analysis, especially with non-uniform material such as ground biomass, and more than 50 equally spaced sieves were required to match the sieveless all distinct particles PSD analysis. Results substantiate that mechanical sieving, owing to handling limitations and inconsistent length-based separation of particles, is inadequate in determining the PSD of non-uniform particulate samples. The developed computer vision sieveless PSD analysis approach has the potential to replace the standard mechanical sieving. The plugin can be readily extended to model (e.g., Rosin Rammler) the PSD of materials, and mass-based analysis, while providing several advantages such as accuracy, speed, low cost, automated analysis, and reproducible results.

Igathinathane, C. [Mississippi State University (MSU); Pordesimo, L. O. [Mississippi State University (MSU); Columbus, Eugene P [ORNL; Batchelor, William D [ORNL; Sokhansanj, Shahabaddine [ORNL

2009-05-01T23:59:59.000Z

84

Analytical Solutions to the Stochastic Kinetic Equation for Liquid and Ice Particle Size Spectra. Part I: Small-Size Fraction  

Science Conference Proceedings (OSTI)

The kinetic equation of stochastic condensation for cloud drop size spectra is extended to account for crystalline clouds and also to include the accretion–aggregation process. The size spectra are separated into small and large size fractions ...

Vitaly I. Khvorostyanov; Judith A. Curry

2008-07-01T23:59:59.000Z

85

The Occurrence of Particle Size Distribution Bimodality in Midlatitude Cirrus as Inferred from Ground-Based Remote Sensing Data  

Science Conference Proceedings (OSTI)

Data collected in midlatitude cirrus clouds by instruments on jet aircraft typically show particle size distributions that have distinct distribution modes in both the 10–30-?m maximum dimension (D) size range and the 200–300-?m D size range or ...

Yang Zhao; Gerald G. Mace; Jennifer M. Comstock

2011-06-01T23:59:59.000Z

86

Surface Area, Volume, Mass, and Density Distributions for Sized Biomass Particles  

DOE Green Energy (OSTI)

This final technical report describes work performed at Morehouse College under DOE Grant No. DE-FC26-04NT42130 during the period July 01, 2004 to June 30, 2007 which covers the entire performance period of the project. 25 individual biomass particles (hardwood sawdust AI14546 in the size range of 100-200 microns) were levitated in an electrodynamic balance (EDB) and their external surface area, volume, and drag coefficient/mass (C{sub d}/m) ratios were characterized applying highly specialized video based and high-speed diode array imaging systems. Analysis methods were employed using shape and drag information to calculate mass and density distributions for these particles. Results of these measurements and analyses were validated by independent mass measurements using a particle weighing and counting technique. Similar information for 28 PSOC 1451D bituminous coal particles was retrieved from a previously published work. Using these two information, density correlations for coal/biomass blends were developed. These correlations can be used to estimate the density of the blend knowing either the volume fraction or the mass fraction of coal in the blend. The density correlations presented here will be useful in predicting the burning rate of coal/biomass blends in cofiring combustors. Finally, a discussion on technological impacts and economic projections of burning biomass with coal in US power plants is presented.

Ramanathan Sampath

2007-06-30T23:59:59.000Z

87

Chemical Synthesis of Nano-Sized particles of Lead Oxide and their Characterization Studies  

E-Print Network (OSTI)

The quantum dots of semiconductor display novel and interesting phenomena that have not been in the bulk material. The color tunability is one of the most attractive characteristics in II-VI semiconductor nanoparticles such as CdS, ZnS, CdSe, ZnSe and PbO. In this work, the semiconductor lead oxide nanoparticles are prepared by chemical method. The average particle size, specific surface area, crystallinity index are estimated from XRD analysis. The structural, functional groups and optical characters are analyzed with using of SEM, FTIR and UV- Visible techniques. The optical band gap value has also been determined.

M. Alagar; T. Theivasanthi; A. Kubera Raja

2012-04-04T23:59:59.000Z

88

Particle size distribution of airborne plutonium near a chemical separations facility  

Science Conference Proceedings (OSTI)

Particulate matter containing Pu-238 and Pu-239,240 emitted from a stack at the Savannah River Plant was collected and fractionated by size with cascade impactors. Two impactor measurements were made at a distance of 200 meters from the H-Area stack and a third was at a distance of 420 meters. Annual collections were made for three years. The Pu-238 and Pu 239,240 concentrations were determined for each of the size fractions. The fractions collected at 200 m from the 62 m stack showed a biphasic curve for both Pu-238 and Pu-239,240. The highest concentration for both Pu-238 and Pu-239,240 were found in the <0.49 ..mu..m fraction, with the secondary peak occurring in the fractions greater than 3.0 ..mu..m. At 420 meters from the stack, the size distribution curves for Pu-238 and Pu-239,240 were not biphasic; only one peak appeared and that was for the fraction less than 0.49 ..mu..m. The doses to different organs from plutonium inhalation were calculated for the particle size distributions obtained in this study. The maximum potential 50-year dose commitment to the bone, the critical organ, for one year continuous exposure was 13 mrem for Pu-238 and 0.44 mrem for Pu-239,240 at 200 meters from the H-Area stack.

Gay, D.D.; Watts, J.R.

1981-12-01T23:59:59.000Z

89

Evaluation of fine-particle size catalysts using bituminous and subbituminous coals  

SciTech Connect

The objectives of Sandia`s fine-particle size catalyst testing project are to evaluate and compare the activities of fine-particle size catalysts being developed in DOE/PETC`s Advanced Research Coal Liquefaction Program by using Sandia`s standard coal liquefaction test procedures. The first test procedure uses bituminous coal (DECS-17 Blind Canyon coal), phenanthrene as the reaction solvent, and a factorial experimental design that is used to evaluate catalysts over ranges of temperature, time, and catalyst loading. The best catalyst evaluated to date is West Virginia University`s iron catalyst that was impregnated onto the coal. Current work is aimed at developing a standard test procedure using subbituminous Wyodak coal. Ibis test is being developed using Pacific Northwest Laboratories` 6-line ferrihydrite catalyst and coal samples impregnated with either molybdenum or iron at Argonne National Laboratories. Results of testing catalysts with bituminous coal will be summarized and the development of the subbituminous coal test procedure will be presented.

Stohl, F.V.; Diegert, K.V.; Goodnow, D.C.

1996-06-01T23:59:59.000Z

90

Improved Normalization of the Size Distribution of Atmospheric Particles Retrieved from Aureole Measurements Using the Diffraction Approximation  

Science Conference Proceedings (OSTI)

This paper describes an improvement in the diffraction approximation used to retrieve the size distribution of atmospheric particles from solar aureole radiance measurements. Normalization using total optical thickness based on measurement of the ...

J. G. DeVore

2011-08-01T23:59:59.000Z

91

On the Aerosol Particle Size Distribution Spectrum in Alaskan Air Mass Systems: Arctic Haze and Non-Haze Episodes  

Science Conference Proceedings (OSTI)

Aerosols in central Alaskan winter air mass system were classified according to size by diffusive separation and light-scattering spectrometry. Particles entering central Alaska from the Pacific Marine environment had number concentrations ...

Glenn E. Shaw

1983-05-01T23:59:59.000Z

92

Efficient recovery of nano-sized iron oxide particles from synthetic acid-mine drainage (AMD) water using fuel cell  

E-Print Network (OSTI)

Efficient recovery of nano-sized iron oxide particles from synthetic acid-mine drainage (AMD) water electricity. Here we show that this approach can also be used as a technique to generate spherical nano

93

Particles in the Lower Troposphere over the High Plains of the United States. Part I: Size Distributions, Elemental Compositions and Morphologies  

Science Conference Proceedings (OSTI)

Airborne measurements are presented of particle size distributions obtained during spring and summer at various locations in the High Plains of the United States. Two main particle modes are apparent: an accumulation mode between particle ...

Peter V. Hobbs; David A. Bowdle; Lawrence F. Radke

1985-12-01T23:59:59.000Z

94

Scattering by Nonspherical Particles of Size Comparable to a Wavelength: A New Semi-Empirical Theory and Its Application to Tropospheric Aerosols  

Science Conference Proceedings (OSTI)

We propose an approximate method for evaluating the interaction Of randomly oriented. nonspherical particles with the total intensity component of electromagnetic radiation. When the particle size parameter x (the ratio of particle circumference ...

James B. Pollack; Jeffrey N. Cuzzi

1980-04-01T23:59:59.000Z

95

Electrical Mobility Spectrometer Using a Diethylene Glycol Condensation Particle Counter for Measurement of Aerosol Size Distributions Down to 1 nm  

Science Conference Proceedings (OSTI)

We report a new scanning mobility particle spectrometer (SMPS) for measuring number size distributions of particles down to {approx}1 nm mobility diameter. This SMPS includes an aerosol charger, a TSI 3085 nano differential mobility analyzer (nanoDMA), an ultrafine condensation particle counter (UCPC) using diethylene glycol (DEG) as the working fluid, and a conventional butanol CPC (the 'booster') to detect the small droplets leaving the DEG UCPC. The response of the DEG UCPC to negatively charged sodium chloride particles with mobility diameters ranging from 1-6 nm was measured. The sensitivity of the DEG UCPC to particle composition was also studied by comparing its response to positively charged 1.47 and 1.70 nm tetra-alkyl ammonium ions, sodium chloride, and silver particles. A high resolution differential mobility analyzer was used to generate the test particles. These results show that the response of this UCPC to sub-2 nm particles is sensitive to particle composition. The applicability of the new SMPS for atmospheric measurement was demonstrated during the Nucleation and Cloud Condensation Nuclei (NCCN) field campaign (Atlanta, Georgia, summer 2009). We operated the instrument at saturator and condenser temperatures that allowed the efficient detection of sodium chloride particles but not of air ions having the same mobility. We found that particles as small as 1 nm were detected during nucleation events but not at other times. Factors affecting size distribution measurements, including aerosol charging in the 1-10 nm size range, are discussed. For the charger used in this study, bipolar charging was found to be more effective for sub-2 nm particles than unipolar charging. No ion induced nucleation inside the charger was observed during the NCCN campaign.

Jiang, J.; Kuang, C.; Chen, M.; Attoui, M.; McMurry, P. H.

2011-02-01T23:59:59.000Z

96

Continuum representation of a continuous size distribution of particles engaged in rapid granular flow  

Science Conference Proceedings (OSTI)

Natural and industrial granular flows often consist of several particle sizes, approximately forming a continuous particle size distribution (PSD). Continuous PSDs are ubiquitous, though existing kinetic-theory-based, hydrodynamic models for rapid granular flows are limited to a discrete number of species. The objective of this work is twofold: (i) to determine the number of discrete species required to accurately approximate a continuous PSD and (ii) to validate these results via a comparison with molecular dynamics (MD) simulations of continuous PSDs. With regard to the former, several analytic (Gaussian and lognormal) and experimental (coal and lunar soil simulants) distributions are investigated. Transport coefficients (pressure, shear viscosity, etc.) of the granular mixture given by the polydisperse theory of Garz´o et al. [“Enskog theory for polydisperse granular mixtures. I. Navier-Stokes order transport,” Phys. Rev. E 76, 031303 (2007);“Enskog theory for polydisperse granular mixtures. I. Navier-Stokes order transport,” 76, 031304 (2007)] are compared using an increasing number of species s to approximate the given PSD. These discrete approximations are determined by matching the first 2s moments of the approximation and the given continuous distribution. Relatively few species are required to approximate moderately wide distributions (Gaussian, lognormal), whereas even wider distributions (coal and lunar soil simulants) require a larger number of species. Regarding the second objective, a comparison between MD simulations and kinetictheory predictions for a simple shear flow of both Gaussian and lognormal PSDs reveal essentially no loss of accuracy stemming from the polydisperse theory itself (as compared to theories for monodisperse systems) or from the discrete approximations of continuous PSDs used in the polydisperse theory. C #2; 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4744987

Murray, J.A.; Benyahia, S.; Metzger, P.; Hrenya, C.M.

2012-01-01T23:59:59.000Z

97

Characterization of Particle Size Standard NIST 1019b with SynchrotronX-ray Microtomography and Digital Data Extraction  

Science Conference Proceedings (OSTI)

We show that synchrotron x-ray microtomography ({mu}CT) followed by digital data extraction can be used to examine the size distribution and particle morphologies of the polydisperse (750 to 2450 {micro}m diameter) particle size standard NIST 1019b. Our size distribution results are within errors of certified values with data collected at 19.5 {micro}m/voxel. One of the advantages of using {mu}CT to investigate the particles examined here is that the morphology of the glass beads can be directly examined. We use the shape metrics aspect ratio and sphericity to examine of individual standard beads morphologies as a function of spherical equivalent diameters. We find that the majority of standard beads possess near-spherical aspect ratios and sphericities, but deviations are present at the lower end of the size range. The majority (> 98%) of particles also possess an equant form when examined using a common measure of equidimensionality. Although the NIST 1019b standard consists of loose particles, we point out that an advantage of {mu}CT is that coherent materials comprised of particles can be examined without disaggregation.

Friedrich, Jon M.; Rivers, Mark L.; Perlowitz, Michael A.; Meinhart, Zachary; Ramirez, Vanessa V. (UC); (Fordham)

2012-07-11T23:59:59.000Z

98

THE EFFECTS OF FLAME TEMPERATURE, PARTICLE SIZE AND EUROPIUM DOPING CONCENTRATION ON THE PROPERTIES OF Y2O3:EU PARTICLES FORMED IN A FLAME AEROSOL PROCESS  

E-Print Network (OSTI)

Y2O3:Eu particles are phosphors that have found wide applications. Flamesynthesized Y2O3:Eu particles may have either the cubic or the monoclinic structure. The effects of particle size and Eu doping concentration on crystal structure and the surface elemental composition of the flame-synthesized Y2O3:Eu particles had not been previously reported. In this study, a flame aerosol process was used to generate polydisperse Y2O3:Eu particle. H2 was used as the fuel gas, with either air or O2 gas as the oxidizer. The precursor was aqueous solutions of the metal nitrates, atomized using a 1.7-MHz ultrasonic atomizer. The product particles were analyzed by transmission electron microscopy (TEM), X-ray diffractometer (XRD), Selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), fluorescence spectrophotometer, and inductively coupled plasma mass spectrometer (ICP-MS). The Y2O3:Eu particles generated in H2/O2 flames were spherical and fully dense, with diameters in the range of 10~3000 nm. In particle samples with lower Eu doping concentrations, a critical particle diameter was found, whose value increased with increasing Eu doping concentration. Particles well below the critical diameter had the monoclinic structure; those well above the critical diameter had the cubic structure. At sufficiently high Eu doping concentrations, all Y2O3:Eu generated in H2/O2 flames had the monoclinic structure. On the other hand, all particles generated in the H2/air flames had the cubic structure. For the Y2O3:Eu particles generated in H2/O2 flames, XPS results showed that the surface Eu concentration was several times higher than the doping concentration. For Y2O3:Eu particles generated in H2/air flames, the surface Eu concentration was equal to the doping concentration. For both types of particles, the photoluminescence intensity reached a maximum corresponding to a surface Eu concentration 40~50%. The photoluminescence intensity then decreased rapidly with higher Eu doping concentration. The effect of particle size and Eu doping concentration on crystal structure may be explained by the interplay between surface energy and polymorphism. A mechanism for this surface enrichment phenomenon was proposed based on the binary Eu2O3-Y2O3 phase diagram.

Yim, Hoon

2009-05-01T23:59:59.000Z

99

Numerical modeling of the aerodynamics, heat exchange, and combustion of a polydisperse ensemble of coke-ash particles in ascending axisymmetric two-phase flow  

Science Conference Proceedings (OSTI)

A two-dimensional stationary model of motion, heat and mass exchange, and chemical reaction of polydisperse coke and ash particles in ascending gas-suspension flow has been constructed with allowance for the turbulent and pseudo turbulent mechanisms of transfer in the dispersed phase. The system of equations that describes motion and heat transfer in the solid phase has been closed at the level of the equations for the second moments of velocity and temperature pulsations, whereas the momentum equations of the carrying medium have been closed using the equation for turbulent gas energy, which allows for the influence of the particles and heterogeneous reactions.

B.B. Rokhman [National Academy of Sciences of Ukraine, Kiev (Ukraine). Institute of Coal Power Technologies

2009-07-15T23:59:59.000Z

100

The effects of moisture and particle size of feedlot biomass on co-firing burner performance  

E-Print Network (OSTI)

Biomass (conventional and non-conventional) fuels co-fired with coal for power and steam generation are being tested and evaluated at several generation stations in the United States. The co-firing technology is expected to reduce landfill requirements for biomass wastes, and to provide a renewable, low pollution and zero net carbon dioxide fuel. The choice of the biomass depends upon local availability and cost of the transportation. The renewable biomass fuels range from agro to animal waste based fuels. For coal fired power plants located around feedlots where cattle are raised, the renewable biomass is the cattle manure, called feedlot biomass (FB). Thus coal could be mixed with feedlot biomass and then fired in existing boiler burners. A 30 KW (100,000 Btu/hr) boiler burner facility was built at Texas A&M University Boiler Burner Laboratory and the burner was fired with coal or coal-FB blends. Most of the previous data concerned with coal performance results from co-firing of low moisture FB (25%); so feeding at low flow rate becomes a problem. In order to test the effects of moisture on burner performance, the reactor was modified with external water injection through an atomizer in order to simulate higher moisture. The atomizer uses an airblast to atomize the water into finer droplets. At fixed equivalence ratio and swirl number for the secondary inlet air stream, the test variables selected were simulated moisture contents and particle sizes of feedlot biomass. Measurements of NO[], O?, CO and CO? along the furnace are reported. The summaries of results are as follows. With the atomized air only (i.e. without external water injection), the NO[] concentrations increased from 350 ppm to 650 ppm while CO decreased from 46,000 ppm to 18,000 ppm (data measured at the first probe, 6" from the burner). The external water injection used to simulate high moisture FB decreased the pollutant emissions (NO[]) from 570 ppm (zero external water with atomizing air injection) to 300 ppm (40% water in FB) but increased CO from 2,500 ppm (zero external water with atomizing air injection) to 10,500 ppm (40% water in FB) (data of moisture effect measured at the last probe, 36" from the burner) due to more incomplete burning. The small particles FB produced less NO[] but more CO than those from other sizes.

Chen, Chen-Jung

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Evaluation of fine-particle size catalysts using standard test procedures  

SciTech Connect

The goal of this project is to evaluate and compare the activities/selectivities of fine-particle size catalysts being developed in the DOE/PETC Advanced Research (AR) Liquefaction Program by using standard coal liquefaction activity test procedures. Since bituminous and subbituminous coals have significantly different properties, it is feasible that catalysts may perform differently with these coal types. Because all previous testing has been done with the DECS-17 Blind Canyon bituminous coal, it is important to develop the capability of evaluating catalysts using a subbituminous coal. Initial efforts towards developing a subbituminous coal test are aimed at comparing the reactivities of the Wyodak subbituminous coal and the Blind Canyon bituminous coal. Therefore, the same factorial experimental design was used with the Wyodak coal as was used previously with the Blind Canyon coal. In addition, PNL`s 6-line ferrihydrite catalyst precursor was used in the development of the Wyodak coal test procedure because this catalyst is the best powder catalyst found to date in Sandia`s tests with Blind Canyon coal. Results show that Blind Canyon coal yields higher DHP amounts in the reaction products and higher tetrahydrofuran conversions at the higher severity conditions. Wyodak coal gives higher heptane conversions and higher gas yields for all conditions tested.

Stohl, F.V.; Diegert, K.V.; Goodnow, D.C.

1996-07-01T23:59:59.000Z

102

EFFECTS OF QUARTZ PARTICLE SIZE AND SUCROSE ADDITION ON MELTING BEHAVIOR OF A MELTER FEED FOR HIGH-LEVEL GLASS  

SciTech Connect

The behavior of melter feed (a mixture of nuclear waste and glass-forming additives) during waste-glass processing has a significant impact on the rate of the vitrification process. We studied the effects of silica particle size and sucrose addition on the volumetric expansion (foaming) of a high-alumina feed and the rate of dissolution of silica particles in feed samples heated at 5 C/min up to 1200 C. The initial size of quartz particles in feed ranged from 5 to 195 {micro}m. The fraction of the sucrose added ranged from 0 to 0.20 g per g glass. Extensive foaming occurred only in feeds with 5-{micro}m quartz particles; particles {ge}150 {micro}m formed clusters. Particles of 5 {micro}m completely dissolved by 900 C whereas particles {ge}150 {micro}m did not fully dissolve even when the temperature reached 1200 C. Sucrose addition had virtually zero impact on both foaming and the dissolution of silica particles. Over 100 sites in the United States are currently tasked with the storage of nuclear waste. The largest is the Hanford Site located in southeastern Washington State with 177 subterranean tanks containing over fifty-million gallons of nuclear waste from plutonium production from 1944 through 1987. This waste will be vitrified at the Hanford Tank Waste Treatment and Immobilization Plant. In the vitrification process, feed is charged into a melter and converted into glass to be ultimately stored in a permanent repository. The duration of waste-site cleanups by the vitrification process depends on the rate of melting, i.e., on the rate of the feed-to-glass conversion. Foaming associated with the melting process and the rate of dissolution of quartz particles (silica being the major glass-forming additive) are assumed to be important factors that influence the rate of melting. Previous studies on foaming of high-alumina feed demonstrated that varying the makeup of a melter feed has a significant impact on foaming. The volume of feeds that contained 5-{micro}m quartz particles substantially increased because of foaming. The extent of foaming decreased as the particle size of quartz increased. Moreover, samples containing quartz particles 195 {micro}m formed agglomerates at temperatures above 900 C that only slowly dissolved in the melt. This study continues previous work on the feed-melting process, specifically on the effects of the size of silica particles on the formation of nuclear-waste glasses to determine a suitable range of silica particle sizes that causes neither excessive foaming nor undesirable agglomeration. Apart from varying the silica-particle size, carbon was added in the form of sucrose. Sucrose has been used to accelerate the rate of melting. In this study, we have observed its impact on feed foaming and quartz dissolution.

MARCIAL J; KRUGER AA; HRMA PR; SCHWEIGER MJ; SWEARINGEN KJ; TEGROTENHUIS WE; HENAGER SH

2010-07-28T23:59:59.000Z

103

A Bayesian Approach to Upscaling and Downscaling of Aircraft Measurements of Ice Particle Counts and Size Distributions  

Science Conference Proceedings (OSTI)

This study addresses the issue of how to upscale cloud-sized in situ measurements of ice to yield realistic simulations of ice clouds for a variety of modeling studies. Aircraft measurements of ice particle counts along a 79 km zigzag path were ...

A. R. Jameson; A. J. Heymsfield

104

A Model Predicting the Evolution of Ice Particle Size Spectra and Radiative Properties of Cirrus Clouds. Part I: Microphysics  

Science Conference Proceedings (OSTI)

A Lagrangian time-dependent three-dimensional model was developed that predicts the evolution of ice particle size spectra in cirrus clouds in terms of the growth processes of vapor diffusion and aggregation, as well as the cloud updraft profile. ...

David L. Mitchell

1994-03-01T23:59:59.000Z

105

A Bayesian Approach to Upscaling and Downscaling of Aircraft Measurements of Ice Particle Counts and Size Distributions  

Science Conference Proceedings (OSTI)

This study addresses the issue of how to upscale cloud-sized in situ measurements of ice to yield realistic simulations of ice clouds for a variety of modeling studies. Aircraft measurements of ice particle counts along a 79-km zigzag path were ...

A. R. Jameson; A. J. Heymsfield

2013-09-01T23:59:59.000Z

106

Aerosol Particle Size Distribution (0.1–1.0 ?m) during the Chinooks of 1979 over Calgary, Canada  

Science Conference Proceedings (OSTI)

During the winter months of 1979, an Active Scattering Aerosol Spectrometer was operated in down-town Calgary to measure the effect of chinooks on the aerosol particle size distribution in the range 0.1–1.0 ?m. An Aerovironment Acoustic Sounder ...

C. V. Mathai; A. W. Harrison; T. Mathews

1980-05-01T23:59:59.000Z

107

Hydrated and Dried Aerosol-Size-Distribution Measurements from the Particle Measuring Systems FSSP-300 Probe and the Deiced PCASP-100X Probe  

Science Conference Proceedings (OSTI)

Comparisons of particle-size distributions measured by Particle Measuring Systems FSSP-300 and PCASP-100X probes through a range of relative humidities reveal that the deiced PCASP-100X probe dries hydrated submicron aerosols before measurement. ...

J. Walter Strapp; W. R. Leaitch; P. S. K. Liu

1992-10-01T23:59:59.000Z

108

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

Science Conference Proceedings (OSTI)

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

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

2012-10-23T23:59:59.000Z

109

Ground-Based Remote Sensing of Cloud Particle Sizes during the 26 November 1991 FIRE II Cirrus Case: Comparisons with In Situ Data  

Science Conference Proceedings (OSTI)

The paper presents the results of retrieving characteristic particle sizes for the November 26 1991 FIRE II case using two methods that utilize ground-based remotes sensors. The size information for the complete vertical depth of the cloud was ...

S. Y. Matrosov; A. J. Heymsfield; J. M. Intrieri; B. W. Orr; J. B. Snider

1995-12-01T23:59:59.000Z

110

Influence of content and particle size of waste pet bottles on concrete behavior at different w/c ratios  

SciTech Connect

The goal of this work was to study the mechanical behavior of concrete with recycled Polyethylene Therephtalate (PET), varying the water/cement ratio (0.50 and 0.60), PET content (10 and 20 vol%) and the particle size. Also, the influence of the thermal degradation of PET in the concrete was studied, when the blends were exposed to different temperatures (200, 400, 600 {sup o}C). Results indicate that PET-filled concrete, when volume proportion and particle size of PET increased, showed a decrease in compressive strength, splitting tensile strength, modulus of elasticity and ultrasonic pulse velocity; however, the water absorption increased. On the other hand, the flexural strength of concrete-PET when exposed to a heat source was strongly dependent on the temperature, water/cement ratio, as well as on the PET content and particle size. Moreover, the activation energy was affected by the temperature, PET particles location on the slabs and water/cement ratio.

Albano, C. [Universidad Central de Venezuela, Facultad de Ingenieria, Caracas (Venezuela, Bolivarian Republic of)], E-mail: carmen.albano@ucv.ve; Camacho, N. [Universidad Central de Venezuela, Facultad de Ingenieria, Caracas (Venezuela, Bolivarian Republic of)], E-mail: nelsoncamachog@gmail.com; Hernandez, M. [Universidad Simon Bolivar, Departamento de Mecanica, Caracas (Venezuela, Bolivarian Republic of); Matheus, A.; Gutierrez, A. [Universidad Central de Venezuela, Facultad de Ingenieria, Caracas (Venezuela, Bolivarian Republic of)

2009-10-15T23:59:59.000Z

111

Physicochemical Characterization of Capstone Depleted Uranium Aerosols I: Uranium Concentration in Aerosols as a Function of Time and Particle Size  

SciTech Connect

During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing depleted uranium were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol sample was first quantified by radioanalytical methods, and selected samples, primarily those from the cyclone separator grit chambers, were analyzed radiochemically. Deposition occurred inside the vehicles as particles settled on interior surfaces. Settling rates of uranium from the aerosols were evaluated using filter cassette samples that collected aerosol as total mass over eight sequential time intervals. A moving filter was used to collect aerosol samples over time particularly within the first minute after the shot. The results demonstrate that the peak uranium concentration in the aerosol occurred in the first 10 s, and the concentration decreased in the Abrams tank shots to about 50% within 1 min and to less than 2% 30 min after perforation. In the Bradley vehicle, the initial (and maximum) uranium concentration was lower than those observed in the Abrams tank and decreased more slowly. Uranium mass concentrations in the aerosols as a function of particle size were evaluated using samples collected in the cyclone samplers, which collected aerosol continuously for 2 h post perforation. The percentages of uranium mass in the cyclone separator stages from the Abrams tank tests ranged from 38% to 72% and, in most cases, varied with particle size, typically with less uranium associated with the smaller particle sizes. Results with the Bradley vehicle ranged from 18% to 29% and were not specifically correlated with particle size.

Parkhurst, MaryAnn; Cheng, Yung-Sung; Kenoyer, Judson L.; Traub, Richard J.

2009-03-01T23:59:59.000Z

112

No-slip boundary condition in finite-size dissipative particle dynamics  

Science Conference Proceedings (OSTI)

Dissipative particle dynamics (DPD) is an efficient, particle based mesoscopic numerical scheme to simulate dynamics of complex fluids and micro-flows, with spatio-temporal scales in the range of micrometers and microseconds. While the traditional DPD ... Keywords: Boundary conditions, DPD, Density fluctuations, Impenetrability, No-slip, Tunable slip

S. Kumar Ranjith; B. S. V. Patnaik; Srikanth Vedantam

2013-01-01T23:59:59.000Z

113

Detailed modeling of size distribution functions and hydrogen content in combustion-formed particles  

SciTech Connect

A kinetic modeling approach is proposed to delve into the nature and chemistry of combustion-produced particles. A sectional method is used for the first time on this purpose. It is based on modeling of gas-to-particle transitions by sections containing 125 lumped species with C numbers ranging from 24 to 4 x 10{sup 8} and H/C ratio ranging from 0 to 1. This allows not only the mass evolution of particles, but also their hydrogen content to be followed. The model is tested in an atmospheric pressure premixed flat flame of ethylene/oxygen with C/O = 0.8 and cold gas flow velocity of 4 cm/s. Comparison of modeled results with experimental data is satisfying in terms of species concentrations and H/C ratio of the particles. Analysis of model results in comparison with the experimental data has shown that it is possible to distinguish different precursors of particles moving from the exit of the burner into the post-oxidation region of the flame. At particle inception, i.e. just downstream from the flame front, gas-phase PAHs are responsible for particle nucleation and oligomers of aromatic hydrocarbons and small pericondensed hydrocarbons are predominantly present. Then the dehydrogenation process takes place and soot formation starts; in this zone large pericondensed and stacked structures are produced. Further up soot maturation generally linked with dehydrogenation is present, but still a few particles with higher H/C and with low coagulation efficiency are produced and remain present along the flame. The model, in accordance with experimental structural soot analysis, shows that in soot particles condensed structures typical of clusters of large pericondensed hydrocarbons are present whereas high-molecular mass condensed species mainly comprise oligomers of small aromatic compounds of clusters of small pericondensed hydrocarbons. (author)

Sirignano, Mariano; D'Anna, Andrea [Dipartimento di Ingegneria Chimica, Universita di Napoli ''Federico II'', Napoli (Italy); Kent, John [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney (Australia)

2010-06-15T23:59:59.000Z

114

Freight Wing Trailer Aerodynamics  

SciTech Connect

Freight Wing Incorporated utilized the opportunity presented by this DOE category one Inventions and Innovations grant to successfully research, develop, test, patent, market, and sell innovative fuel and emissions saving aerodynamic attachments for the trucking industry. A great deal of past scientific research has demonstrated that streamlining box shaped semi-trailers can significantly reduce a truck's fuel consumption. However, significant design challenges have prevented past concepts from meeting industry needs. Market research early in this project revealed the demands of truck fleet operators regarding aerodynamic attachments. Products must not only save fuel, but cannot interfere with the operation of the truck, require significant maintenance, add significant weight, and must be extremely durable. Furthermore, SAE/TMC J1321 tests performed by a respected independent laboratory are necessary for large fleets to even consider purchase. Freight Wing used this information to create a system of three practical aerodynamic attachments for the front, rear and undercarriage of standard semi trailers. SAE/TMC J1321 Type II tests preformed by the Transportation Research Center (TRC) demonstrated a 7% improvement to fuel economy with all three products. If Freight Wing is successful in its continued efforts to gain market penetration, the energy and environmental savings would be considerable. Each truck outfitted saves approximately 1,100 gallons of fuel every 100,000 miles, which prevents over 12 tons of CO2 from entering the atmosphere. If all applicable trailers used the technology, the country could save approximately 1.8 billion gallons of diesel fuel, 18 million tons of emissions and 3.6 billion dollars annually.

Graham, Sean (Primary Investigator); Bigatel, Patrick

2004-10-17T23:59:59.000Z

115

Soot particle sizing during high-pressure Diesel spray combustion via time-resolved laser-induced incandescence  

Science Conference Proceedings (OSTI)

Single-pulse time-resolved laser-induced incandescence (TiRe-LII) signal transients from soot particulates were acquired during unsteady high pressure Diesel combustion in a constant volume cell for typical top dead center conditions during a Diesel engine cycle. Measurements were performed for initial gas pressures between 1 and 3 MPa, injection pressures between 50 and 130 MPa and laser probe timings between 5 and 16 ms after start of fuel injection. In separate experiments and for the same cell operating conditions gas temperatures were deduced from spectrally resolved soot pyrometry measurements. Implementing the LII model of Kock et al. [Combust. Flame 147 (2006) 79-92] ensemble mean soot particle diameters were evaluated from least-squares fitting of theoretical cooling curves to experimental TiRe-LII signal transients. Since in the experiments the environmental gas temperature and the width of an assumed particle size distribution were not known, the effects of the initial choice of these parameters on retrieved particle diameters were investigated. It is shown that evaluated mean particle diameters are only slightly biased by the choice of typical size distribution widths and gas temperatures. For a fixed combustion phase mean particle diameters are not much affected by gas pressure, however they become smaller at high fuel injection pressure. At a mean chamber pressure of 1.39 MPa evaluated mean particle diameters increased by a factor of two for probe delays between 5 and 16 ms after start of injection irrespective of the choices of first-guess fitting variables, indicating a certain robustness of data analysis procedure. (author)

Ryser, R.; Gerber, T.; Dreier, T. [Reaction Analysis Group, Department of General Energy, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

2008-11-15T23:59:59.000Z

116

Soot particle sizing during high-pressure Diesel spray combustion via time-resolved laser-induced incandescence  

Science Conference Proceedings (OSTI)

Single-pulse time-resolved laser-induced incandescence (TiRe-LII) signal transients from soot particulates were acquired during unsteady high pressure Diesel combustion in a constant volume cell for typical top dead center conditions during a Diesel engine cycle. Measurements were performed for initial gas pressures between 1 and 3 MPa, injection pressures between 50 and 130 MPa and laser probe timings between 5 and 16 ms after start of fuel injection. In separate experiments and for the same cell operating conditions gas temperatures were deduced from spectrally resolved soot pyrometry measurements. Implementing the LII model of Kock et al. [Combust. Flame 147 (20006) 79-92] ensemble mean soot particle diameters were evaluated from least-squares fitting of theoretical cooling curves to experimental TiRe-LII signal transients. Since in the experiments the environmental gas temperature and the width of an assumed particle size distribution were not known, the effects of the initial choice of these parameters on retrieved particle diameters were investigated. It is shown that evaluated mean particle diameters are only slightly biased by the choice of typical size distribution widths and gas temperatures. For a fixed combustion phase mean particle diameters are not much affected by gas pressure, however they become smaller at high fuel injection pressure. At a mean chamber pressure of 1.39 MPa evaluated mean particle diameters increased by a factor of two for probe delays between 5 and 16 ms after start of injection irrespective of the choices of first-guess fitting variables, indicating a certain robustness of data analysis procedure. (author)

Ryser, R.; Gerber, T.; Dreier, T. [Reaction Analysis Group, Department of General Energy, Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

2009-01-15T23:59:59.000Z

117

KNIFE MILL COMMINUTION ENERGY ANALYSIS OF SWITCHGRASS, WHEAT STRAW, AND CORN STOVER AND CHARACTERIZATION OF PARTICLE SIZE DISTRIBUTIONS  

Science Conference Proceedings (OSTI)

Biomass preprocessing and pretreatment technologies such as size reduction and chemical preconditioning are aimed at reducing the cost of ethanol production from lignocellulosic biomass. Size reduction is an energy-intensive biomass preprocessing unit operation. In this study, switchgrass, wheat straw, and corn stover were chopped in an instrumented knife mill to evaluate size reduction energy and corresponding particle size distribution as determined with a standard forage sieve analyzer. Direct mechanical power inputs were determined using a dedicated data acquisition system for knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. A speed of 250 rpm gave optimum performance of the mill. Optimum feed rates for 25.4 mm screen and 250 rpm were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively. Total specific energy (MJ/Mg) was defined as the size reduction energy required to operate the knife mill plus that imparted to the biomass. Effective specific energy was defined as the energy imparted to the biomass. For these conditions, total specific energies were 27.3, 37.9, and 31.9 MJ/Mg and effective specific energies were 10.1, 15.5, and 3.2 MJ/Mg for switchgrass, wheat straw, and corn stover, respectively. These results demonstrated that biomass selection affects the size reduction energy, even for biomass with similar features. Second-order polynomial equations for the total specific energy requirement fitted well (R2 > 0.95) as a function of knife mill screen size, mass feed rate, and speed for biomass materials tested. The Rosin-Rammler equation fitted the cumulative undersize mass of switchgrass, wheat straw, and corn stover chop passed through ASABE sieves with high R2 (>0.983). Knife mill chopping of switchgrass, wheat straw, and corn stover resulted in particle size distributions classified as 'well-graded strongly fine-skewed mesokurtic', 'well-graded fine-skewed mesokurtic', and 'well-graded fine-skewed mesokurtic', respectively, for small knife mill screen sizes (12.7 to 25.4 mm) and distributions classified as 'well-graded fine-skewed mesokurtic', 'well-graded strongly fine-skewed mesokurtic', and 'well-graded fine-skewed mesokurtic', respectively, for the large screen size (50.8 mm). Total and effective specific energy values per unit size reduction of wheat straw were greater compared to those for switchgrass. Corn stover resulted in reduced total and effective specific energy per unit size reduction compared to wheat straw for the same operating conditions, but higher total specific energy per unit size reduction and lesser effective specific energy per unit size reduction compared to switchgrass. Data on minimized total specific energy with corresponding particle spectra will be useful for preparing feed material with a knife mill for subsequent grinding with finer size reduction devices.

Bitra, V.S.P. [University of Tennessee, Knoxville (UTK); Womac, A.R. [University of Tennessee, Knoxville (UTK); Sokhansanj, Shahabaddine [ORNL; Igathinathane, C. [North Dakota State University

2010-01-01T23:59:59.000Z

118

Investigation of the effect of coal particle sizes on the interfacial and rheological properties of coal-water slurry fuels: Final report, July 1, 1994-June 30, 1996  

SciTech Connect

The scope of the project is two fold: (1) examining particle size effect on interfacial properties of CWS fuels by measuring static and dynamic surface tension properties of specially prepared CWS samples containing different ranges of coal particle sizes, and (2) studying the effect of particle size on CWS atomization characteristics by measuring mean diameters of several different CWS sprays generated by sonic air blasting. The results show that both static and dynamic surface tensions decrease with increasing coal particle size and mean droplet diameter of CW-S sprays also decreases with increasing coal particle size. Based on the experimental evidence we conjecture that three different energies are competing in slurry atomization: (1) the internal capillary holding between particles and water, (2) the interfacial surface tensile energy at the slurry surface contacting air, and (3) the external air blast shear energy acting against the former two energies. The internal capillary holding force decreases with increasing particle size. This force is believed to play a major role in determining the effect of particle size on CWS atomization.

Kihm, K.D.

1996-10-01T23:59:59.000Z

119

Effect of particle size and volume fraction on tensile properties of fly ash/polyurea composites  

E-Print Network (OSTI)

particles. In addition, the composites filled with 20% fly ash became softer. These samples showed lower, composites, tensile properties 1. INTRODUCTION Fly ash, a waste by-product generated abundantly in electric processibility of the filled materials5 . Furthermore, as a waste by-product, its usage decreases the overall

Nemat-Nasser, Sia

120

WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES  

E-Print Network (OSTI)

of a building was explored [2]. Referred to such applications, a VAWT can be so small in physical size that its by the present authors to study the aerodynamic performance of small VAWTs using the experimental and numerical1 WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES J. J. Miau*1

Leu, Tzong-Shyng "Jeremy"

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121

Influence by small dispersive coal dust particles of different fractional consistence on characteristics of iodine air filter at nuclear power plant  

E-Print Network (OSTI)

The main purpose of research is to determine the influence by the small dispersive coal dust particles of the different fractional consistence on the technical characteristics of the vertical iodine air filter at nuclear power plant. The research on the transport properties of the small dispersive coal dust particles in the granular filtering medium of absorber in the vertical iodine air filter is completed in the case, when the modeled aerodynamic conditions are similar to the real aerodynamic conditions. It is shown that the appearance of the different fractional consistence of small dispersive coal dust particles with the decreasing dimensions down to the micro and nano sizes at the action of the air dust aerosol stream normally results in a significant change of distribution of the small dispersive coal dust particles masses in the granular filtering medium of an absorber in the vertical iodine air filter, changing the vertical iodine air filter aerodynamic characteristics. The precise characterization of...

Neklyudov, I M; Fedorova, L I; Poltinin, P Ya

2013-01-01T23:59:59.000Z

122

Combustion characteristics of fuel droplets with addition of nano and micron-sized aluminum particles  

E-Print Network (OSTI)

Combustion characteristics of fuel droplets with addition of nano and micron-sized aluminum form 27 July 2010 Accepted 3 September 2010 Keywords: High-energy-density fuels Droplet combustion n-decane-based fuels. Five distinctive stages (preheating and ignition, classical combustion

Qiao, Li

123

Description of sprays using joint hyperbolic distribution in particle size and velocity  

SciTech Connect

The joint probability density functions of droplet size and velocity have been represented in sprays by the two-dimensional hyperbolic distribution. A distribution is provided, and a procedure to compute its eight parameters outlined. Analytical expressions for certain statistical quantities, such as mean diameters, momentum, kinetic energy etc., applicable under certain restrictions, are obtained. The computations for a water spray issuing from a Danfoss 60{degrees} solid cone oil-burner nozzle demonstrate not only that the hyperbolic distribution provides an excellent approximation for the joint size and velocity distributions for the measurements taken along the entire length of the spray axis, but also that such representation presents a clear insight into the physics of the motion and the related size formation. The computations reveal a developing region, with areas dominated by breakup or coalescence of droplets, followed by a developed state with little change in droplet size but continuously decreasing velocity. It is concluded that this novel approach is well suited to the description of sprays.

Bhatia, J.C.; Durst, F. (LSTM-Erlangen, Lehrstuhl fur Stromungsmechanik, Universitat Erlangen-Nurnberg, 8520 Erlangen (DE))

1990-09-01T23:59:59.000Z

124

The Occurrence of Particle Size Distribution Bimodality in Midlatitude Cirrus as Inferred from Ground-Based Remote Sensing Data  

SciTech Connect

To better understand the role of small particles in the microphysical processes and the radiative properties of cirrus, the reliability of historical in-situ data must be understood. Recent studies call into question the validity of that data because of shattering of large crystals on probe and aircraft surfaces thereby artificially amplifying the concentration of crystals smaller than approximately 50 ?m. We contend that the general character of the in-situ measurements must be consistent, in a broad sense, with statistics derived from long-term remote sensing data. To examine this consistency, an algorithm using Doppler radar moments and Raman lidar extinction is developed to retrieve a bimodal particle size distribution and its uncertainty. Using case studies and statistics compiled over one year we show that the existence of high concentrations (> 1 cm-3 ) of small (sub 50 ?m) particles in cirrus are not consistent with any reasonable interpretation of the remote sensing data. We conclude that the high concentrations of small particles found in many aircraft data sets are therefore likely an artifact of the in situ measurement process.

Zhao, Yang; Mace, Gerald G.; Comstock, Jennifer M.

2011-06-01T23:59:59.000Z

125

Modeling Simulation Of Pyrolysis Of Biomass: Effect Of Thermal Conductivity, Reactor Temperature And Particle Size On Product Concentrations  

E-Print Network (OSTI)

The simultaneous chemical kinetics and heat transfer model is used to predict the effects of the most important physical and thermal properties (thermal conductivity, reactor temperature and particle size) of the feedstock on the convective-radiant pyrolysis of biomass fuels. The effects of these parameters have been analyzed for different geometries such as slab, cylinder and sphere. Finite difference method is employed for solving heat transfer model equation while Runge-Kutta 4 th order method is used for solving chemical kinetics model equations. Simulations are carried out for equivalent radius ranging from 0.0000125 m to 0.02 m, and temperature ranging from 303 K to 2100 K.

Chaurasia And Babu; A. S. Chaurasia; B. V. Babu

2003-01-01T23:59:59.000Z

126

Measurements of Plutonium and Americium in Soil Samples from Project 57 using the Suspended Soil Particle Sizing System (SSPSS)  

Science Conference Proceedings (OSTI)

As part of the preliminary site characterization conducted for Project 57, soils samples were collected for separation into several size-fractions using the Suspended Soil Particle Sizing System (SSPSS). Soil samples were collected specifically for separation by the SSPSS at three general locations in the deposited Project 57 plume, the projected radioactivity of which ranged from 100 to 600 pCi/g. The primary purpose in focusing on samples with this level of activity is that it would represent anticipated residual soil contamination levels at the site after corrective actions are completed. Consequently, the results of the SSPSS analysis can contribute to dose calculation and corrective action-level determinations for future land-use scenarios at the site.

John L. Bowen; Rowena Gonzalez; David S. Shafer

2001-05-01T23:59:59.000Z

127

The Impact of Oil Consumption Mechanisms on Diesel Exhaust Particle Size Distributions and Detailed Exhaust Chemical Composition  

DOE Green Energy (OSTI)

Detailed exhaust emission data have been taken from a Cummins N-14 single cylinder research engine in which the oil consumption was varied by different engine modifications. Low sulfur fuel was used, and oil consumption was varied by modifying the intake valve stem seals, the exhaust valve stem seals, the oil control ring and combinations of these modifications. Detailed measurements of exhaust gas particle size distributions and chemical composition were made for the various oil consumption configurations for a range of engine loads and speeds. The particulate mass was measured with TEOM and traditional gravimetric filter methods. Filter data for EC/OC, sulfates and trace metals have been taken and analyzed. The trace metals in the particulate mass serve as the basis for assessing oil consumption at the different operating conditions. The data indicate that the oil consumption for the steady state testing done here was approximately an order of magnitude below oil consumption values cited in the literature. We did measure changes in the details of the chemical composition of the particulate for the different engine operating conditions, but it did not correlate with changes in the oil consumption. Furthermore, the data indicate that the particle size distribution is not strongly impacted by low level oil consumption variations observed in this work.

Stetter, J; Forster, N; Ghandhi, J; Foster, D

2003-08-24T23:59:59.000Z

128

Aerosol Size Distribution, Particle Concentration, and Optical Property Variability near Caribbean Trade Cumulus Clouds: Isolating Effects of Vertical Transport and Cloud Processing from Humidification Using Aircraft Measurements  

Science Conference Proceedings (OSTI)

This paper examines the effect of trade wind cumulus clouds on aerosol properties in the near-cloud environment using data from the Rain in Cumulus over the Ocean (RICO) campaign. Aerosol size distributions, particle concentrations, and optical ...

Robert M. Rauber; Guangyu Zhao; Larry Di Girolamo; Marilé Colón-Robles

2013-10-01T23:59:59.000Z

129

Determining Size Distributions and Composition of Particles Suspended in Water: A New SEM–EDS Protocol with Validation and Comparison to Other Methods  

Science Conference Proceedings (OSTI)

Knowledge of particle size distributions (PSDs) in seawater is important for understanding several facets of marine science, such as the behavior of light scattering in seawater, phytoplankton dynamics, and biogeochemical cycling. Here, a method ...

Heather Groundwater; Michael S. Twardowski; Heidi M. Dierssen; Antoine Sciandra; Scott A. Freeman

2012-03-01T23:59:59.000Z

130

Ostwald Ripening and Its Effect on PuO2 Particle Size in Hanford Tank Waste  

Science Conference Proceedings (OSTI)

Between 1944 and 1989, the Hanford Site produced 60 percent (54.5 metric tons) of the United States weapons plutonium and produced an additional 12.9 metric tons of fuels-grade plutonium. High activity wastes, including plutonium lost from the separations processes used to isolate the plutonium, were discharged to underground storage tanks during these operations. Plutonium in the Hanford tank farms is estimated to be {approx}700 kg but may be up to {approx}1000 kg. Despite these apparent large quantities, the average plutonium concentration in the {approx}200 million liter tank waste volume is only about 0.003 grams per liter ({approx}0.0002 wt%). The plutonium is largely associated with low solubility metal hydroxide/oxide sludges where its low concentration and intimate mixture with neutron-absorbing elements (e.g., iron) are credited in nuclear criticality safety. However, concerns have been expressed that plutonium, in the form of plutonium hydrous oxide, PuO{sub 2} {center_dot} xH{sub 2}O, could undergo sufficient crystal growth through Ostwald ripening in the alkaline tank waste to potentially be separable from neutron absorbing constituents by settling or sedimentation. It was found that plutonium that entered the alkaline tank waste by precipitation through neutralization from acid solution is initially present as 2- to 3-nm (0.002- to 0.003-{mu}m) scale PuO{sub 2} {center_dot} xH{sub 2}O crystallite particles and grows from that point at exceedingly slow rates, posing no risk to physical segregation. These conclusions are reached by both general considerations of Ostwald ripening and specific observations of the behaviors of PuO{sub 2} and PuO{sub 2} {center_dot} xH{sub 2}O upon aging in alkaline solution.

Delegard, Calvin H.

2011-09-29T23:59:59.000Z

131

A GCM Parameterization of Ice Particle Mean Effective Sizes for High Latitude Cirrus Clouds and It's Comparison with Mid-Latitude Parmaterization  

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

GCM Parameterization of Ice Particle Mean Effective GCM Parameterization of Ice Particle Mean Effective Sizes for High Latitude Cirrus Clouds and It's Comparison with Mid-Latitude Parameterization F. S. Boudala Department of Oceanography Dalhousie University Halifax, Nova Scotia, Canada Q. Fu Department of Atmospheric Sciences University of Washington Seattle, Washington G. A. Issac Meteorological Service of Canada Toronto, Ontario, Canada Introduction Single-scattering properties of ice clouds depend on both ice water content (IWC) and effective size of cloud particles (Fu 1996; Fu et al. 1998). However, only the IWC information is provided in numerical models. Stephens et al. (1990) showed that the ice cloud feedback on a CO 2 warming simulation could be either positive or negative depending on the value of the ice particle size assumed. Parameterizations

132

Particle size effect of hydride formation and surface hydrogen absorption of nanosized palladium catalysts : L{sub 3} edge vs K edge x-ray absorption spectroscopy.  

Science Conference Proceedings (OSTI)

The particle size effect on the formation of palladium hydride and on surface hydrogen adsorption was studied at room temperature using in situ X-ray absorption spectroscopy at the Pd K and L{sub 3} edges. Hydride formation was indirectly observed by lattice expansion in Pd K edge XANES spectra and by EXAFS analysis. Hydride formation was directly detected in the L{sub 3} edge spectra. A characteristic spectral feature caused by the formation of a Pd-H antibonding state showed strong particle size dependence. The L{sub 3} edge spectra were reproduced using full multiple scattering analysis and density of state calculations, and the contributions of bulk absorbed and surface hydrogen to the XANES spectra could be distinguished. The ratio of hydrogen on the surface versus that in the bulk increased with decreasing particle size, and smaller particles dissolved less hydrogen.

Tew, M. W.; Miller, J. T.; van Bokhoven, J. A. (Chemical Sciences and Engineering Division); ( SUF-USR); (ETH Zurich)

2009-08-01T23:59:59.000Z

133

Irreversible volume growth in polymer-bonded powder systems: effects of crystalline anisotropy, particle size distribution, and binder strength  

Science Conference Proceedings (OSTI)

Pressed-powdered crystallites of intrinsically anisotropic materials have been shown to undergo irreversible volume expansion when subjected to repeated cycles of heating and cooling. We develop a coarse-grained (micron-scale) interaction Hamiltonian for this system and perform molecular dynamics simulations, which quantitatively reproduce the experimentally observed irreversible growth. The functional form and values of the interaction parameters at the coarse-grained level are motivated by our knowledge at the atomic/molecular scale, and allows a simple way to incorporate the effect of polymeric binder. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy of the powder material, is mediated by particles much smaller than the average crystallite size, and can be significantly reduced in the presence of high-strength polymeric binder with elevated glass transition temperatures.

Maiti, A; Gee, R H; Hoffman, D; Fried, L E

2007-08-22T23:59:59.000Z

134

Oxygen Reduction on Well-Defined Core-Shell Nanocatalysts: Particle Size, Facet, and Pt Shell Thickness Effects  

DOE Green Energy (OSTI)

We examined the effects of the thickness of the Pt shell, lattice mismatch, and particle size on specific and mass activities from the changes in effective surface area and activity for oxygen reduction induced by stepwise Pt-monolayer depositions on Pd and Pd{sub 3}Co nanoparticles. The core?shell structure was characterized at the atomic level using Z-contrast scanning transmission electron microscopy coupled with element-sensitive electron energy loss spectroscopy. The enhancements in specific activity are largely attributed to the compressive strain effect based on the density functional theory calculations using a nanoparticle model, revealing the effect of nanosize-induced surface contraction on facet-dependent oxygen binding energy. The results suggest that moderately compressed (111) facets are most conducive to oxygen reduction reaction on small nanoparticles and indicate the importance of concerted structure and component optimization for enhancing core?shell nanocatalysts activity and durability.

Wang, J.X.; Inada, H.; Wu, L.; Zhu, Y.; Choi, Y.; Liu, P.; Zhou, W.-P.; Adzic, R.R.

2009-11-09T23:59:59.000Z

135

Aerodynamic Contrails: Phenomenology and Flow Physics  

Science Conference Proceedings (OSTI)

Aerodynamic contrails have been recognized for a long time although they appear sporadically. Usually one observes them under humid conditions near the ground, where they are short-lived phenomena. Aerodynamic contrails appear also at cruise ...

K. Gierens; B. Kärcher; H. Mannstein; B. Mayer

2009-02-01T23:59:59.000Z

136

Investigation of aerodynamic braking devices for wind turbine applications  

DOE Green Energy (OSTI)

This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.

Griffin, D.A. [R. Lynette & Associates, Seattle, WA (United States)

1997-04-01T23:59:59.000Z

137

Experimental and analytical research on the aerodynamics of wind driven turbines. Final report  

DOE Green Energy (OSTI)

This aerodynamic research program was aimed at providing a reliable, comprehensive data base on a series of wind turbine models covering a broad range of the prime aerodynamic and geometric variables. Such data obtained under controlled laboratory conditions on turbines designed by the same method, of the same size, and tested in the same wind tunnel had not been available in the literature. Moreover, this research program was further aimed at providing a basis for evaluating the adequacy of existing wind turbine aerodynamic design and performance methodology, for assessing the potential of recent advanced theories and for providing a basis for further method development and refinement.

Rohrbach, C.; Wainauski, H.; Worobel, R.

1977-12-01T23:59:59.000Z

138

Microstructure of TRISO Coated Particles from the AGR-1 Experiment I: SiC Grain Size and Grain Boundary Character  

SciTech Connect

Pre-irradiation SiC microstructures in TRISO coated fuel particles from the AGR-1 experiment were quantitatively characterized using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). From EBSD it was determined that only the cubic polymorph of as-deposited SiC was present and the SiC had a high fraction of CSL S3 grain boundaries. Additionally, the local area misorientation (LAM), which is a qualitative measurement of strain in the SiC lattice, was mapped for each fuel variant. The morphology of the SiC / IPyC interfaces were characterized by TEM following site-specific focused ion beam (FIB) specimen preparation. It was determined that the SiC layer had a heavily faulted microstructure typical of CVD deposited SiC and that the average grain diameter increased from the SiC/IPyC interface for all the fuel variants, except V3 that showed a constant grain size across the layer.

Rita Kirchhofer; John D, Hunn; Paul A. Demkowicz; James I. Cole; Brian P. Gorman

2013-01-01T23:59:59.000Z

139

Direct mechanical energy measures of hammer mill comminution of switchgrass, wheat straw, and corn stover and analysis of their particle size distributions  

Science Conference Proceedings (OSTI)

Biomass particle size impacts handling, storage, conversion, and dust control systems. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented hammer mill. Direct energy inputs were determined for hammer mill operating speeds from 2000 to 3600 rpm for 3.2 mm integral classifying screen and mass input rate of 2.5 kg/min with 90 - and 30 -hammers. Overall accuracy of specific energy measurement was calculated as 0.072 MJ/Mg. Particle size distributions created by hammer mill were determined for mill operating factors using ISO sieve sizes from 4.75 to 0.02 mm in conjunction with Ro-Tap sieve analyzer. A wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Total specific energy (MJ/Mg) was defined as size reduction energy to operate the hammer mill plus that imparted to biomass. Effective specific energy was defined as energy imparted to biomass. Total specific energy for switchgrass, wheat straw, and corn stover grinding increased by 37, 30, and 45% from 114.4, 125.1, and 103.7 MJ/Mg, respectively, with an increase in hammer mill speed from 2000 to 3600 rpm for 90 -hammers. Corresponding total specific energy per unit size reduction was 14.9, 19.7, and 13.5 MJ/Mg mm, respectively. Effective specific energy of 90 -hammers decreased marginally for switchgrass and considerably for wheat straw and it increased for corn stover with an increase in speed from 2000 to 3600 rpm. However, effective specific energy increased with speed to a certain extent and then decreased for 30 -hammers. Rosin Rammler equation fitted the size distribution data with R2 > 0.995. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Hammer milling of switchgrass, wheat straw, and corn stover with 3.2 mm screen resulted in well-graded fine-skewed mesokurtic particles. Uniformity coefficient was corn stover, which indicated a moderate assortment of particles. Size-related parameters, namely, geometric mean diameter, Rosin Rammler size parameter, median diameter, and effective size had strong correlation among themselves and good negative correlation with speed. Distribution-related parameters, namely, Rosin Rammler distribution parameter, mass relative span, inclusive graphic skewness, graphic kurtosis, uniformity index, uniformity coefficient, coefficient of gradation and distribution geometric standard deviation had strong correlation among themselves and a weak correlation with mill speed. Results of this extensive analysis of specific energy and particle sizes can be applied to selection of hammer mill operating factors to produce a particular size of switchgrass, wheat straw, and corn stover grind, and will serve as a guide for relations among the energy and various analytic descriptors of biomass particle distributions.

Bitra, V.S.P [University of Tennessee; Womac, A.R. [University of Tennessee; Chevanan, Nehru [University of Tennessee; Miu, P.I. [University of Tennessee; Smith, D.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Sokhansanj, Shahabaddine [ORNL

2009-07-01T23:59:59.000Z

140

Ice Cloud Particle Size Distributions and Pressure-Dependent Terminal Velocities from In Situ Observations at Temperatures from 0 to ?86 C  

Science Conference Proceedings (OSTI)

The primary goal of this study is to derive ice particle terminal velocities from micron to cm sizes and for atmospheric pressures covering the range 200–1000 hPa from data spanning a wide range of locations, temperatures, and altitudes and to ...

Andrew J. Heymsfield; Carl Schmitt; Aaron Bansemer

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141

Particle Size Estimation in Ice-Phase Clouds Using Multifrequency Radar Reflectivity Measurements at 95, 33, and 2.8 GHz  

Science Conference Proceedings (OSTI)

Multifrequency radar measurements collected at 2.8 (S band), 33.12 (Ka band), and 94.92 GHz (W band) are processed using a neural network to estimate median particle size and peak number concentration in ice-phase clouds composed of dry crystals ...

Stephen M. Sekelsky; Warner L. Ecklund; John M. Firda; Kenneth S. Gage; Robert E. McIntosh

1999-01-01T23:59:59.000Z

142

A Parameterization of the Particle Size Spectrum of Ice Clouds in Terms of the Ambient Temperature and the Ice Water Content  

Science Conference Proceedings (OSTI)

A data set obtained in cirrus clouds has been examined to deduce any dependencies of the particle size spectral form or the crystal habit on the temperature. It was found that both form of the spectra and crystal habit changed systematically with ...

Andrew J. Heymsfield; C. M. R. Platt

1984-03-01T23:59:59.000Z

143

Performance of a Focused Cavity Aerosol Spectrometer for Measurements in the Stratosphere of Particle Size in the 0.06–2.0-µm-Diameter Range  

Science Conference Proceedings (OSTI)

A focused cavity aerosol spectrometer aboard a NASA ER-2 high-altitude aircraft provided high-resolution measurements of the size of the stratospheric particles in the 0.06–2.0-µm-diameter range in flights following the eruption of Mount Pinatubo ...

H.H. Jonsson; J.C. Wilson; C.A. Brock; R.G. Knollenberg; T.R. Newton; J.E. Dye; D. Baumgardner; S. Borrmann; G.V. Ferry; R. Pueschel; Dave C. Woods; Mike C. Pitts

1995-02-01T23:59:59.000Z

144

On Techniques to Characterize and Correlate Grain Size, Grain Boundary Orientation and the Strength of the SiC Layer of TRISO Coated Particles: A Preliminary Study  

Science Conference Proceedings (OSTI)

The mechanical properties of the silicon carbide (SiC) layer of the TRi-ISOtropic (TRISO) coated particle (CP) for high temperature gas reactors (HTGR) are performance parameters that have not yet been standardized by the international HTR community. Presented in this paper are the results of characterizing coated particles to reveal the effect of annealing temperature (1000 to 2100°C) on the strength and grain size of unirradiated coated particles. This work was further expanded to include possible relationships between the grain size and strength values. The comparative results of two strength measurement techniques and grain size measured by the Lineal intercept method are included. Preliminary grain boundary characterization results determined by electron backscatter diffraction (EBSD) are included. These results are also important for future fission product transport studies, as grain boundary diffusion is identified as a possible mechanism by which 110mAg, one of the fission activation products, might be released through intact SiC layers. Temperature is a parameter known to influence the grain size of SiC and therefore it is important to investigate the effect of high temperature annealing on the SiC grain size. Recommendations and future work will also be briefly discussed.

I.J.van Rooyen; J.L. Dunzik Gougar; T. Trowbridge; Philip M van Rooyen

2012-10-01T23:59:59.000Z

145

Aerodynamic Losses and Heat Transfer in a Blade Cascade with...  

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

Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3 Blade Cascade with 3 - - D D Endwall Endwall Contouring Contouring...

146

Aerodynamic Drag and Gyroscopic Stability  

E-Print Network (OSTI)

This paper describes the effects on aerodynamic drag of rifle bullets as the gyroscopic stability is lowered from 1.3 to 1.0. It is well known that a bullet can tumble for stability less than 1.0. The Sierra Loading Manuals (4th and 5th Editions) have previously reported that ballistic coefficient decreases significantly as gyroscopic stability, Sg, is lowered below 1.3. These observations are further confirmed by the experiments reported here. Measured ballistic coefficients were compared with gyroscopic stabilities computed using the Miller Twist Rule for nearly solid metal bullets with uniform density and computed using the Courtney-Miller formula for plastic-tipped bullets. The experiments reported here also demonstrate a decrease in aerodynamic drag near Sg = 1.23 +/- 0.02. It is hypothesized that this decrease in drag over a narrow band of Sg values is due to a rapid damping of coning motions (precession and nutation). Observation of this drag decrease at a consistent value of Sg demonstrates the relative accuracy of the twist formulas used to compute Sg. The relationship between Sg and drag may be used to test the applicability of existing twist formulas to given bullet designs and to evaluate the accuracy of alternate formulas in cases where the existing twist formulas are not as accurate.

Elya R. Courtney; Michael W. Courtney

2013-08-15T23:59:59.000Z

147

DOE Project on Heavy Vehicle Aerodynamic Drag  

SciTech Connect

Class 8 tractor-trailers consume 11-12% of the total US petroleum use. At highway speeds, 65% of the energy expenditure for a Class 8 truck is in overcoming aerodynamic drag. The project objective is to improve fuel economy of Class 8 tractor-trailers by providing guidance on methods of reducing drag by at least 25%. A 25% reduction in drag would present a 12% improvement in fuel economy at highway speeds, equivalent to about 130 midsize tanker ships per year. Specific goals include: (1) Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles; (2) Develop innovative drag reducing concepts that are operationally and economically sound; and (3) Establish a database of experimental, computational, and conceptual design information, and demonstrate the potential of new drag-reduction devices. The studies described herein provide a demonstration of the applicability of the experience developed in the analysis of the standard configuration of the Generic Conventional Model. The modeling practices and procedures developed in prior efforts have been applied directly to the assessment of new configurations including a variety of geometric modifications and add-on devices. Application to the low-drag 'GTS' configuration of the GCM has confirmed that the error in predicted drag coefficients increases as the relative contribution of the base drag resulting from the vehicle wake to the total drag increases and it is recommended that more advanced turbulence modeling strategies be applied under those circumstances. Application to a commercially-developed boat tail device has confirmed that this restriction does not apply to geometries where the relative contribution of the base drag to the total drag is reduced by modifying the geometry in that region. Application to a modified GCM geometry with an open grille and radiator has confirmed that the underbody flow, while important for underhood cooling, has little impact on the drag coefficient of the vehicle. Furthermore, the evaluation of the impact of small changes in radiator or grille dimensions has revealed that the total drag is not particularly sensitive to those changes. This observation leads to two significant conclusions. First, a small increase in radiator size to accommodate heat rejection needs related to new emissions restrictions may be tolerated without significant increases in drag losses. Second, efforts to reduce drag on the tractor requires that the design of the entire tractor be treated in an integrated fashion. Simply reducing the size of the grille will not provide the desired result, but the additional contouring of the vehicle as a whole which may be enabled by the smaller radiator could have a more significant effect.

McCallen, R; Salari, K; Ortega, J; Castellucci, P; Pointer, D; Browand, F; Ross, J; Storms, B

2007-01-04T23:59:59.000Z

148

Effects of dry bulk density and particle size fraction on gas transport parameters in variably saturated landfill cover soil  

SciTech Connect

Highlights: > The effects of soil physical properties on gas transport parameters were investigated. > Higher values of D{sub p} and k{sub a} exhibited in the '+gravel' than the '-gravel' fraction at same soil-air content ({epsilon}). > Recent power law models for D{sub p} (WLR) and k{sub a} (RPL) were modified. > Model parameters were linearly related to easily measurable dry bulk density ({rho}{sub b}). - Abstract: Landfill sites are emerging in climate change scenarios as a significant source of greenhouse gases. The compacted final soil cover at landfill sites plays a vital role for the emission, fate and transport of landfill gases. This study investigated the effects of dry bulk density, {rho}{sub b}, and particle size fraction on the main soil-gas transport parameters - soil-gas diffusivity (D{sub p}/D{sub o}, ratio of gas diffusion coefficients in soil and free air) and air permeability (k{sub a}) - under variably-saturated moisture conditions. Soil samples were prepared by three different compaction methods (Standard and Modified Proctor compaction, and hand compaction) with resulting {rho}{sub b} values ranging from 1.40 to 2.10 g cm{sup -3}. Results showed that D{sub p} and k{sub a} values for the '+gravel' fraction (<35 mm) became larger than for the '-gravel' fraction (<2 mm) under variably-saturated conditions for a given soil-air content ({epsilon}), likely due to enhanced gas diffusion and advection through less tortuous, large-pore networks. The effect of dry bulk density on D{sub p} and k{sub a} was most pronounced for the '+gravel' fraction. Normalized ratios were introduced for all soil-gas parameters: (i) for gas diffusivity D{sub p}/D{sub f}, the ratio of measured D{sub p} to D{sub p} in total porosity (f), (ii) for air permeability k{sub a}/k{sub a,pF4.1}, the ratio of measured k{sub a} to k{sub a} at 1235 kPa matric potential (=pF 4.1), and (iii) for soil-air content, the ratio of soil-air content ({epsilon}) to total porosity (f) (air saturation). Based on the normalized parameters, predictive power-law models for D{sub p}({epsilon}/f) and k{sub a}({epsilon}/f) models were developed based on a single parameter (water blockage factor M for D{sub p} and P for k{sub a}). The water blockage factors, M and P, were found to be linearly correlated to {rho}{sub b} values, and the effects of dry bulk density on D{sub p} and k{sub a} for both '+gravel' and '-gravel' fractions were well accounted for by the new models.

Wickramarachchi, Praneeth, E-mail: praneeth1977@yahoo.co.uk [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Kawamoto, Ken; Hamamoto, Shoichiro [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Institute for Environmental Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Nagamori, Masanao [Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115 (Japan); Moldrup, Per [Environmental Engineering Section, Dept. of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, DK-9000 Aalborg (Denmark); Komatsu, Toshiko [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Institute for Environmental Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan)

2011-12-15T23:59:59.000Z

149

Influence by small dispersive coal dust particles of different fractional consistence on characteristics of iodine air filter at nuclear power plant  

E-Print Network (OSTI)

The main purpose of research is to determine the influence by the small dispersive coal dust particles of the different fractional consistence on the technical characteristics of the vertical iodine air filter at nuclear power plant. The research on the transport properties of the small dispersive coal dust particles in the granular filtering medium of absorber in the vertical iodine air filter is completed in the case, when the modeled aerodynamic conditions are similar to the real aerodynamic conditions. It is shown that the appearance of the different fractional consistence of small dispersive coal dust particles with the decreasing dimensions down to the micro and nano sizes at the action of the air dust aerosol stream normally results in a significant change of distribution of the small dispersive coal dust particles masses in the granular filtering medium of an absorber in the vertical iodine air filter, changing the vertical iodine air filter aerodynamic characteristics. The precise characterization of the aerodynamic resistance of a model of the vertical iodine air filter is completed. The comparative analysis of the technical characteristics of the vertical and horizontal iodine air filters is also made.

I. M. Neklyudov; O. P. Ledenyov; L. I. Fedorova; P. Ya. Poltinin

2013-02-18T23:59:59.000Z

150

Investigation of the particle size distribution and particle density characteristics of Douglas fir hogged fuel fly ash collected under known combustion conditions. Technical Progress Report No. 2  

DOE Green Energy (OSTI)

The increased interest in wood as a fuel source, coupled with the increasing demand to control the emission generated by wood combustion, has created a need for information characterizing the emissions that occur for given combustion conditions. This investigation characterizes the carbon char and inorganic fly ash size and density distribution for each of thirty-eight Douglas fir bark samples collected under known conditions of combustion.

Lang, A.J.; Junge, D.C.

1978-12-01T23:59:59.000Z

151

Design and development of an ultrafine particle reflection-time-of-flight mass spectrometer  

E-Print Network (OSTI)

The primary motivation for the research is to study the effect of small particles on global climate. The study can also help to understand the dynamics involved with gas to particle conversion, which is being debated to be a rich source for atmospheric aerosol. However, the most important use would be to study health effects, since small particles easily diffuse into the lungs, with seemingly little physiological filtration mechanism. The research work involves the design, development and characterization of a single-ultrafine-particle mass spectrometer. The instrument aerodynamically size selects fine and ultrafine aerosol particles (size range 20 nm-1 []m), with a constant Stokes number, and focuses them into a vacuum chamber. This is achieved by changing the upstream pressure of the inlet, which changes aerodynamic drag experienced by the particle. After its entry into the chamber, the particle is ablated by a high power excimer laser, which produces ions from the original molecular constituents. Reflectron time-of-flight mass spectrometry is utilized to analyze the ions, and thus the chemical composition of the particle that was hit. The present work is aimed to overcome the shortcomings of previous instruments, while allowing for increased portability. The instrument is designed, fabricated and experimentally characterized. The first phase involves analysis of the particle beam generated by the inlet. An atomizer generates aerosols from a solution of 5% oleic acid and ethanol. The polydisperse aerosol is passed through a differential mobility analyzer to make a monodisperse mixture, which is transmitted through the inlet. The monodisperse particle beam is intercepted by glass slides, and the spot sizes are indicative of the beam shape and width at the slide positions. A theoretical analysis of the fluid flow field and particle trajectory is developed to correlate with the experimental results. The second phase involves calibration of the mass spectra, and measuring some particulate composition from the laboratory room air.

Das, Rishiraj

2002-01-01T23:59:59.000Z

152

Surface and Particle-Size Effects on Hydrogen Desorption from Catalyst-Doped MgH2  

SciTech Connect

With their high capacity, light-metal hydrides like MgH2 remain under scrutiny as reversible H-storage materials, especially to develop control of H-desorption properties by decreasing size (ball-milling) and/or adding catalysts. By employing density functional theory and simulated annealing, we study initial H2 desorption from semi-infinite stepped rutile (110) surface and Mg31H62 nanoclusters, with(out) transition-metal catalyst dopants (Ti or Fe). While Mg31H62 structures are disordered (amorphous), the semi-infinite surfaces and nanoclusters have similar single, double, and triple H-to-metal bond configurations that yield similar H-desorption energies. Hence, there is no size effect on desorption energetics with reduction in sample size, but dopants do reduce the H-desorption energy. All desorption energies are endothermic, in contrast to a recent report.

Reich, J.M.; Wang, Lin-Lin; Johnson, Duane D.

2012-09-04T23:59:59.000Z

153

Comminution process to produce engineered wood particles of uniform size and shape with disrupted grain structure from veneer  

DOE Patents (OSTI)

Comminution process of wood veneer to produce wood particles, by feeding wood veneer in a direction of travel substantially normal to grain through a counter rotating pair of intermeshing arrays of cutting discs arrayed axially perpendicular to the direction of veneer travel, wherein the cutting discs have a uniform thickness (Td), to produce wood particles characterized by a length dimension (L) substantially equal to the Td and aligned substantially parallel to grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) substantially equal to the veneer thickness (Tv) and aligned normal to W and L, wherein the W.times.H dimensions define a pair of substantially parallel end surfaces with end checking between crosscut fibers.

Dooley, James H; Lanning, David N

2013-07-30T23:59:59.000Z

154

Hypervelocity particle breakup: analysis and experiment. Feasibility report  

SciTech Connect

During the reentry destruction of an isotopic generator, the mechanisms of fuel form ablation must be predictable to properly assess the nuclear hazard associated with the event. Ultimate land deposition patterns and contaminant densities are directly a function of the final ablative particle size. One mechanism of fuel form ablation is the mechanical breakup of molten material by aerodynamic forces created during hypervelocity reentry. The object of this study was to determine the feasibility of describing the breakup phenomenon by statistical mechanical analytic techniques, and to determine the applicability of employing a light gas gun and a controlled environmental range to experimentally observe the breakup phenomenon. (auth)

Osmeyer, W.E.; Olsen, T.M.; Braun, W.

1966-06-01T23:59:59.000Z

155

Particle size effect on TL emission of ZnS nanoparticles and determination of its kinetic parameters  

Science Conference Proceedings (OSTI)

Nanoparticles have large surface area, and most of the ions are lying on its surface. Could these surface ions be contributed in thermoluminescence emission or enhanced nonradiative transition? In view of this, we have prepared small sizes of ZnS nanoparticles ...

L. Robindro Singh; S. Dorendrajit Singh

2012-01-01T23:59:59.000Z

156

16.100 Aerodynamics, Fall 2002  

E-Print Network (OSTI)

This course extends fluid mechanic concepts from Unified Engineering to the aerodynamic performance of wings and bodies in sub/supersonic regimes. 16.100 generally has four components: subsonic potential flows, including ...

Darmofal, David L.

157

System Size, Energy and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy Ion Collisions  

E-Print Network (OSTI)

We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, \\sqrtsnn = 22.4, 62.4 and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. Making a global comparison of Cu+Cu and Au+Au results, we find that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same Npart/2A value rather than the same Npart value. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.

B. Alver; B. B. Back; M. D. Baker; M. Ballintijn; D. S. Barton; R. R. Betts; R. Bindel; W. Busza; Z. Chai; V. Chetluru; E. García; T. Gburek; K. Gulbrandsen; J. Hamblen; I. Harnarine; C. Henderson; D. J. Hofman; R. S. Hollis; R. Ho?y?ski; B. Holzman; A. Iordanova; J. L. Kane; P. Kulinich; C. M. Kuo; W. Li; W. T. Lin; C. Loizides; S. Manly; A. C. Mignerey; R. Nouicer; A. Olszewski; R. Pak; C. Reed; E. Richardson; C. Roland; G. Roland; J. Sagerer; I. Sedykh; C. E. Smith; M. A. Stankiewicz; P. Steinberg; G. S. F. Stephans; A. Sukhanov; A. Szostak; M. B. Tonjes; A. Trzupek; G. J. van Nieuwenhuizen; S. S. Vaurynovich; R. Verdier; G. I. Veres; P. Walters; E. Wenger; D. Willhelm; F. L. H. Wolfs; B. Wosiek; K. Wo?niak; S. Wyngaardt; B. Wys?ouch

2007-09-25T23:59:59.000Z

158

Particle-resolved simulation of aerosol size, composition, mixing state, and the associated optical and cloud condensation nuclei activation properties in an evolving urban plume  

SciTech Connect

The recently developed particle-resolved aerosol box model PartMC-MOSAIC was used to simulate the evolution of aerosol mixing state and the associated optical and cloud condensation nuclei (CCN) activation properties in an idealized urban plume. The model explicitly resolved the size and composition of individual particles from a number of sources and tracked their evolution due to condensation/evaporation, coagulation, emission, and dilution. The ensemble black carbon (BC) specific absorption cross section increased by 40% over the course of two days as a result of BC aging by condensation and coagulation. Three- and four-fold enhancements in CCN/CN ratios were predicted to occur within 6 hours for 0.2% and 0.5% supersaturations (S), respectively. The particle-resolved results were used to evaluate the errors in the optical and CCN activation properties that would be predicted by a conventional sectional framework that assumes monodisperse, internally-mixed particles within each bin. This assumption artificially increased the ensemble BC specific absorption by 14-30% and decreased the single scattering albedo by 0.03-0.07 while the bin resolution had a negligible effect. In contrast, the errors in CCN/CN ratios were sensitive to the bin resolution, and they depended on the chosen supersaturation. For S = 0.2%, the CCN/CN ratio predicted using 100 internally-mixed bins was up to 25% higher than the particle-resolved results, while it was up to 125% higher using 10 internally-mixed bins. Errors introduced in the predicted optical and CCN properties by neglecting coagulation were also quantified.

Zaveri, Rahul A.; Barnard, James C.; Easter, Richard C.; Riemer, Nicole; West, Matthew

2010-09-11T23:59:59.000Z

159

Experimental and analytical research on the aerodynamics of wind driven turbines. Final report  

DOE Green Energy (OSTI)

The successful development of reliable, cost competitive horizontal axis, propeller-type wind energy conversion systems (WECS) is strongly dependent on the availability of advanced technology for each of the system components. This aerodynamic research program was aimed at providing a reliable, comprehensive data base on a series of wind turbine models covering a broad range of the prime aerodynamic and geometric variables. Such data obtained under controlled laboratory conditions on turbines designed by the same method, of the same size, and tested in the same wind tunnel had not been available in the literature. Moreover, this research program was further aimed at providing a basis for evaluating the adequacy of existing wind turbine aerodynamic design and performance methodology, for assessing the potential of recent advanced theories and for providing a basis for further method development and refinement.

Rohrbach, C.; Wainauski, H.; Worobel, R.

1977-12-01T23:59:59.000Z

160

Comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips  

DOE Patents (OSTI)

A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel, wherein the cutting discs have a uniform thickness (T.sub.D), and wherein at least one of L.sub.C, W.sub.C, and H.sub.C is greater than T.sub.D.

Dooley, James H; Lanning, David N

2013-08-13T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Oxidative Dehydrogenation of Cyclohexane on Cobalt Oxide (Co3O4) Nanoparticles: The Effect of Particle Size on Activity and Selectivity  

Science Conference Proceedings (OSTI)

The oxidative dehydrogenation of cyclohexane by cobalt oxide nanoparticles was studied via temperature programmed reaction combined with in situ grazing incidence X-ray absorption spectroscopy and grazing incidence smallangle X-ray scattering and theoretical calculations on model Co3O4 substrates. Both 6 and 12 nm Co3O4 nanoparticles were made through a surfactant-free preparation and dispersed on an Al2O3 surface formed by atomic layer deposition. Under reaction conditions the nanoparticles retained their oxidation state and did not sinter. They instead underwent an assembly/ disassembly process and could reorganize within their assemblies. The selectivity of the catalyst was found to be size- and temperature-dependent, with larger particles preferentially producing cyclohexene at lower temperatures and smaller particles predominantly resulting in benzene at higher temperatures. The mechanistic features thought to control the oxidative dehydrogenation of cyclohexane and other light alkanes on cobalt oxide were established by carrying out density functional theory calculations on the activation of propane, a surrogate model alkane, over model Co3O4 surfaces. The initial activation of the alkane (propane) proceeds via hydrogen abstraction over surface oxygen sites. The subsequent activation of the resulting alkoxide intermediate occurs at a second surface oxygen site to form the alkene (propene) which then desorbs from the surface. Hydroxyl recombination results in the formation of water which desorbs from the surface. Oxygen is necessary to regenerate the surface oxygen sites, catalyze C?H activation steps, and minimize catalyst degradation.

Tyo, Eric C.; Yin, Chunrong; Di Vece, Marcel; Qian, Qiang; Kwon, Gihan; Lee, Sungsik; Lee, Byeongdu; Debartolo, Janae E.; Seifert, Soenke; Winans, R. E.; Si, Rui; Ricks, Brian; Goergen, Simone; Rutter, Matthew; Zugic, Branko; Flytzani-Stephanopoulos, Maria; Wang, Zhi Wei; Palmer, Richard E.; Neurock, Matthew; Vajda, S.

2012-10-02T23:59:59.000Z

162

7, 15951622, 2007 Particle size  

E-Print Network (OSTI)

...........................................................................................26 Time-resolved measurements of surface diffusion induced by ultrashort laser pulses K. Stépán, M-ray radiation-induced damage in DNA monitored by XPS Sylwia Ptasinska...................................................................................................................67 Dissociative Electron Attachment to Fragile Biomolecules Using Laser Induced Acoustic Desorption

Paris-Sud XI, Université de

163

Adhesive-based selection by a tentacle-feeding polychaete for particle size, shape and bacterial coating in silt and sand  

E-Print Network (OSTI)

tendency of less spherical particles to pack more tightly (Donev et al., 2004), potentially in uencing

Jumars, Pete

164

Freight Wing Trailer Aerodynamics Final Technical Report  

Science Conference Proceedings (OSTI)

Freight Wing Incorporated utilized the opportunity presented by a DOE category two Inventions and Innovations grant to commercialize and improve upon aerodynamic technology for semi-tuck trailers, capable of decreasing heavy vehicle fuel consumption, related environmental damage, and U.S. consumption of foreign oil. Major project goals included the demonstration of aerodynamic trailer technology in trucking fleet operations, and the development and testing of second generation products. A great deal of past scientific research has demonstrated that streamlining box shaped semi-trailers can significantly reduce a truck’s fuel consumption. However, significant design challenges have prevented past concepts from meeting industry needs. Freight Wing utilized a 2003 category one Inventions and Innovations grant to develop practical solutions to trailer aerodynamics. Fairings developed for the front, rear, and bottom of standard semi-trailers together demonstrated a 7% improvement to fuel economy in scientific tests conducted by the Transportation Research Center (TRC). Operational tests with major trucking fleets proved the functionality of the products, which were subsequently brought to market. This category two grant enabled Freight Wing to further develop, test and commercialize its products, resulting in greatly increased understanding and acceptance of aerodynamic trailer technology. Commercialization was stimulated by offering trucking fleets 50% cost sharing on trial implementations of Freight Wing products for testing and evaluation purposes. Over 230 fairings were implemented through the program with 35 trucking fleets including industry leaders such as Wal-Mart, Frito Lay and Whole Foods. The feedback from these testing partnerships was quite positive with product performance exceeding fleet expectations in many cases. Fleet feedback also was also valuable from a product development standpoint and assisted the design of several second generation products intended to further improve efficiency, lower costs, and enhance durability. Resulting products demonstrated a 30% efficiency improvement in full scale wind tunnel tests. The fuel savings of our most promising product, the “Belly Fairing” increased from 4% to 6% in scientific track and operational tests. The project successfully demonstrated the economic feasibility of trailer aerodynamics and positioned the technology to realize significant public benefits. Scientific testing conducted with partners such as the EPA Smartway program and Transport Canada clearly validated the fuel and emission saving potential of the technology. The Smartway program now recommends trailer aerodynamics as a certified fuel saving technology and is offering incentives such as low interest loans. Trailer aerodynamics can save average trucks over 1,100 gallons of fuel an 13 tons of emissions every 100,000 miles, a distance many trucks travel annually. These fuel savings produce a product return on investment period of one to two years in average fleet operations. The economic feasibility of the products was validated by participating fleets, several of which have since completed large implementations or demonstrated an interest in volume orders. The commercialization potential of the technology was also demonstrated, resulting in a national distribution and manufacturing partnership with a major industry supplier, Carrier Transicold. Consequently, Freight Wing is well positioned to continue marketing trailer aerodynamics to the trucking industry. The participation of leading fleets in this project served to break down the market skepticism that represents a primary barrier to widespread industry utilization. The benefits of widespread utilization of the technology could be quite significant for both the transportation industry and the public. Trailer aerodynamics could potentially save the U.S. trucking fleet over a billion gallons of fuel and 20 million tons of emissions annually.

Sean Graham

2007-10-31T23:59:59.000Z

165

Flow simulations using particles: bridging computer graphics and CFD  

Science Conference Proceedings (OSTI)

The simulation of the motion of interacting particles is a deceivingly simple, yet powerful and natural method for exploring and animating flows in physical systems as diverse as planetary dark accretion and sea waves, unsteady aerodynamics and nanofluidics.

Petros Koumoutsakos; Georges-Henri Cottet; Diego Rossinelli

2008-08-01T23:59:59.000Z

166

Aerodynamic interference between two Darrieus wind turbines  

DOE Green Energy (OSTI)

The effect of aerodynamic interference on the performance of two curved bladed Darrieus-type vertical axis wind turbines has been calculated using a vortex/lifting line aerodynamic model. The turbines have a tower-to-tower separation distance of 1.5 turbine diameters, with the line of turbine centers varying with respect to the ambient wind direction. The effects of freestream turbulence were neglected. For the cases examined, the calculations showed that the downwind turbine power decrement (1) was significant only when the line of turbine centers was coincident with the ambient wind direction, (2) increased with increasing tipspeed ratio, and (3) is due more to induced flow angularities downstream than to speed deficits near the downstream turbine.

Schatzle, P.R.; Klimas, P.C.; Spahr, H.R.

1981-04-01T23:59:59.000Z

167

Predictions of particle size and lattice diffusion pathway requirements for sodium-ion anodes using eta-Cu6Sn5 thin films as a model system  

SciTech Connect

Geometrically well-defined Cu6Sn5 thin films were used as model systems to estimate the diffusion depth and diffusion pathway requirements of Li and Na ions in alloy anodes. eta-Cu6Sn5 anodes have an initial reversible capacity towards Li of 545 mAh g-1 (Li3.96Sn or 19.8 Li/Cu6Sn5) and a very low initial irreversible capacity of 1.6 Li/Cu6Sn5. In contrast, the reaction with Na is limited with a reversible capacity of 160 mAh g-1 compared to the expected 516 mAh g-1. The potential profile is analogous to that of pure Sn with an average potential of 0.3 V. X-ray diffraction and 119Sn-M ssbauer measurements show that this limited capacity is likely resulting from the limited diffusion of Na into the anode particles not the formation of a low Na-content phase. This is substantiated by the analysis of the structure of eta-Cu6Sn5 which revealed zig-zag and tunnel diffusion pathways with spherical voids with a diameter very close to that of Na+. Moreover, our results also indicate that an alloy of eta-Cu6Sn5 should have optimized particle sizes of about 10 nm in diameter to increase the Na-capacity significantly. An alternative system consisting of a mixture of Cu6Sn5 and Sn of nominal composition Cu6Sn10 has been studied as possible Na-ion anode material possessing higher storage capacity than pure Cu6Sn5. Indeed this mixture of phase delivers a larger initial reversible storage capacity up to 400 mAh g-1. Finally, we have evidenced that the presence of Cu in Cu6Sn5 and in Cu6Sn10 suppresses the anomalous electrolyte decomposition normally measured for pure Sn at 1.2 V during discharge.

Baggetto, Loic [ORNL; Jumas, Dr. Jean-Claude [Institut Charles Gerhardt, University of Montpellier II, FRANCE; Gorka, Joanna [ORNL; Bridges, Craig A [ORNL; Veith, Gabriel M [ORNL

2013-01-01T23:59:59.000Z

168

A computational study of tandem dual wheel aerodynamics and the effect of fenders and fairings on spray dispersion  

SciTech Connect

With the goal of understanding how to mitigate the safety hazard of splash and spray around heavy vehicles, a computational study of the aerodynamics and spray dispersion about a simplified trailer wheel assembly has been completed. A tandem dual slick (TDS) wheel model that neglects complex geometric features such as brakes, wheel bolts and wheel cutouts but with the same dimensions as an actual trailer wheel assembly was used . A detailed simulation of the wheels alone demonstrated that the flow field is both unsteady and complex, containing a number of vortical structures that interact strongly with spray. Preliminary simulations with fenders and fairings demonstrated that these devices prevent the ballistic transport of drops larger than approximately 0.1 mm, but the fine mist speculated to be responsible for visibility reduction is unaffected. This work suggests that to use computational fluid dynamics (CFD) to design and evaluate spray mitigation strategies the jet or sheet breakup processes can be modeled using an array of injectors of small (< 0.01 mm) water droplets; however the choice of size distribution, injection locations, directions and velocities is largely unknown and requires further study. Possible containment strategies would include using flow structures to 'focus' particles into regions away from passing cars or surface treatments to capture small drops.

Paschkewitz, J S

2006-01-13T23:59:59.000Z

169

Wind Turbine Blade Flow Fields and Prospects for Active Aerodynamic Control: Preprint  

DOE Green Energy (OSTI)

This paper describes wind turbine flow fields that can cause adverse aerodynamic loading and can impact active aerodynamic control methodologies currently contemplated for wind turbine applications.

Schreck, S.; Robinson, M.

2007-08-01T23:59:59.000Z

170

GEOPHYSICAL RESEARCH LETTERS, VOL. 9, NO. 10, PAGES 1207-1210, OCTOBEX 1982 PARTICLE SIZE DISTRIBUTION OF NITRATE AND SULFATE IN THE MARINE ATMOSPHERE  

E-Print Network (OSTI)

(also produced from gas-to-particle conversion reactions) which is present primarily on submicron of the what man-41 impaction-surf ace filters. These were extracted in Millipore filtering-centrifuge tubes

Prospero, Joseph M.

171

Single Wall Diesel Particulate Filter (DPF) Filtration Efficiency Studies Using Laboratory Generated Particles  

DOE Green Energy (OSTI)

Diesel offers higher fuel efficiency, but produces higher exhaust particulate matter. Diesel particulate filters are presently the most efficient means to reduce these emissions. These filters typically trap particles in two basic modes: at the beginning of the exposure cycle the particles are captured in the filter holes, and at longer times the particles form a "cake" on which particles are trapped. Eventually the "cake" removed by oxidation and the cycle is repeated. We have investigated the properties and behavior of two commonly used filters: silicon carbide (SiC) and cordierite (DuraTrap® RC) by exposing them to nearly-spherical ammonium sulfate particles. We show that the transition from deep bed filtration to "cake" filtration can easily be identified by recording the change in pressure across the filters as a function of exposure. We investigated performance of these filters as a function of flow rate and particle size. The filters trap small and large particles more efficiently than particles that are ~80 to 200 nm in aerodynamic diameter. A comparison between the experimental data and a simulation using incompressible lattice-Boltzmann model shows very good qualitative agreement, but the model overpredicts the filter’s trapping efficiency.

Yang, Juan; Stewart, Marc; Maupin, Gary D.; Herling, Darrell R.; Zelenyuk, Alla

2009-04-15T23:59:59.000Z

172

Generation of concentration density maxima of small dispersive coal dust particles in horizontal iodine air filter at air-dust aerosol blow  

E-Print Network (OSTI)

The spatial distributions of the small dispersive coal dust particles with the nano and micro sizes in the granular filtering medium with the cylindrical coal granules in the absorber in the horizontal iodine air filter during its long term operation at the nuclear power plant are researched. It is shown that the concentration density maxima of the small dispersive coal dust particles appear in the granular filtering medium with the cylindrical coal absorbent granules in the horizontal iodine air filter at an action by the air dust aerosol blow. The comparison of the measured aerodynamic resistances of the horizontal and vertical iodine air filters is conducted. The main conclusion is that the magnitude of the aerodynamic resistance of the horizontal iodine air filters is much smaller in comparison with the magnitude of the aerodynamic resistance of the vertical iodine air filters at the same loads of the air dust aerosol volumes. It is explained that the direction of the air dust aerosol blow and the directi...

Neklyudov, I M; Fedorova, L I; Poltinin, P Ya

2013-01-01T23:59:59.000Z

173

The essential work of fracture as a means for characterizing the influence of particle size and volume fraction on the fracture toughness of plates of Al/SiC composites  

SciTech Connect

Over the past 20 years, particulate-reinforced aluminium-matrix composites have been increasingly considered for weight-saving applications in the automotive and aerospace industries. The addition of ceramic particles can lead to higher modulus, yield strength and tensile strength. However, the low ductility and fracture toughness of MMCs remain a major obstacle for applications. When the particle volume fraction is high and when plane strain conditions prevail, the inelastic zone surrounding the crack tip is generally small enough as to allow the testing of fracture toughness on laboratory size specimens using conventional linear elastic fracture mechanics (LEFM) methods. However, for composites containing low volume fractions of particles and/or for samples in the shape of thin plates, extensive yielding invalidates LEFM methods. In such cases, fracture toughness may be measured using the essential work of fracture (EWF) approach. This work aims at investigating the application of the EWF method for measuring the fracture toughness of Al/SiC composite plates with different reinforcement sizes and volume fractions. It will be shown that this method allows to highlight the respective contributions of reinforcement size and matrix strain hardening to the toughness of the plates.

Marchal, Y.; Delannay, F. [Universite Catholique de Louvain, Louvain-la-Neuve (Belgium). Dept. des Sciences des Materiaux et des Procedes; Froyen, L. [Katholieke Universiteit Leuven (Belgium). Dept. Metaalkunde en Toegepaste Materiaalkunde

1996-07-15T23:59:59.000Z

174

OPTIMIZATION OF COAL PARTICLE FLOW PATTERNS IN LOW NOX BURNERS  

SciTech Connect

It is well understood that the stability of axial diffusion flames is dependent on the mixing behavior of the fuel and combustion air streams. Combustion aerodynamic texts typically describe flame stability and transitions from laminar diffusion flames to fully developed turbulent flames as a function of increasing jet velocity. Turbulent diffusion flame stability is greatly influenced by recirculation eddies that transport hot combustion gases back to the burner nozzle. This recirculation enhances mixing and heats the incoming gas streams. Models describing these recirculation eddies utilize conservation of momentum and mass assumptions. Increasing the mass flow rate of either fuel or combustion air increases both the jet velocity and momentum for a fixed burner configuration. Thus, differentiating between gas velocity and momentum is important when evaluating flame stability under various operating conditions. The research efforts described herein are part of an ongoing project directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for optimizing low NO{sub x} burners. Experimental studies include both cold-and hot-flow evaluations of the following parameters: primary and secondary inlet air velocity, coal concentration in the primary air, coal particle size distribution and flame holder geometry. Hot-flow experiments will also evaluate the effect of wall temperature on burner performance.

Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Stephanus Budilarto

2001-09-04T23:59:59.000Z

175

CFD calculations of S809 aerodynamic characteristics  

DOE Green Energy (OSTI)

Steady-state, two-dimensional CFD calculations were made for the S809 laminar-flow, wind-turbine airfoil using the commercial code CFD-ACE. Comparisons of the computed pressure and aerodynamic coefficients were made with wind tunnel data from the Delft University 1.8 m x 1.25 m low-turbulence wind tunnel. This work highlights two areas in CFD that require further investigation and development in order to enable accurate numerical simulations of flow about current generation wind-turbine airfoils: transition prediction and turbulence modeling. The results show that the laminar-to-turbulent transition point must be modeled correctly to get accurate simulations for attached flow. Calculations also show that the standard turbulence model used in most commercial CFD codes, the k-{epsilon} model, is not appropriate at angles of attack with flow separation.

Wolfe, W.P. [Sandia National Labs., Albuquerque, NM (United States); Ochs, S.S. [Iowa State Univ., Ames, IA (United States)

1997-01-01T23:59:59.000Z

176

Methods of reducing vehicle aerodynamic drag  

Science Conference Proceedings (OSTI)

A small scale model (length 1710 mm) of General Motor SUV was built and tested in the wind tunnel for expected wind conditions and road clearance. Two passive devices, rear screen which is plate behind the car and rear fairing where the end of the car is aerodynamically extended, were incorporated in the model and tested in the wind tunnel for different wind conditions. The conclusion is that rear screen could reduce drag up to 6.5% and rear fairing can reduce the drag by 26%. There were additional tests for front edging and rear vortex generators. The results for drag reduction were mixed. It should be noted that there are aesthetic and practical considerations that may allow only partial implementation of these or any drag reduction options.

Sirenko V.; Rohatgi U.

2012-07-08T23:59:59.000Z

177

A Model Predicting the Evolution of Ice Particle Size Spectra and Radiative Properties of Cirrus Clouds. Part II: Dependence of Absorption and Extinction on Ice Crystal Morphology  

Science Conference Proceedings (OSTI)

This study builds upon the microphysical modeling described in Part I by deriving formulations for the extinction and absorption coefficients in terms of the size distribution parameters predicted from the microphysical model. The optical depth ...

David L. Mitchell; W. Patrick Arnott

1994-03-01T23:59:59.000Z

178

Aerodynamic performance measurements in a counter-rotating aspirated compressor.  

E-Print Network (OSTI)

??This thesis is an experimental investigation of the aerodynamic performances of a counter-rotating aspirated compressor. This compressor is implemented in a blow-down facility, which gives… (more)

Onnée, Jean-François

2005-01-01T23:59:59.000Z

179

Ris-R-1543(EN) Aerodynamic investigation of Winglets on  

E-Print Network (OSTI)

an aerodynamic load such that the vortex from the winglet spreads out the influence of the tip vortex decreasing, or profile drag, of the winglet is smaller than the decrease in induced drag such that the total drag

180

Aerodynamic performance measurements in a counter-rotating aspirated compressor  

E-Print Network (OSTI)

This thesis is an experimental investigation of the aerodynamic performances of a counter-rotating aspirated compressor. This compressor is implemented in a blow-down facility, which gives rigorous simulation of the ...

Onnée, Jean-François

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Full-scale wind turbine rotor aerodynamics research  

DOE Green Energy (OSTI)

The United States Department of Energy and the National Renewable Energy Laboratory (NREL) are conducting research to improve wind turbine technology at the NREL National Wind Technology Center (NWTC). One program, the Combined Experiment, has focused on making measurements needed to understand aerodynamic and structural responses of horizontal-axis wind turbines (HAWT). A new phase of this program, the Unsteady Aerodynamics Experiment, will focus on quantifying unsteady aerodynamic phenomena prevalent in stall-controlled HAWTs. Optimally twisted blades and innovative instrumentation and data acquisition systems will be used in these tests. Data can now be acquired and viewed interactively during turbine operations. This paper describes the NREL Unsteady Aerodynamics Experiment and highlights planned future research activities.

Simms, D A; Butterfield, C P

1994-11-01T23:59:59.000Z

182

Aerodynamic optimization of a solar powered race vehicle  

E-Print Network (OSTI)

Aerodynamic optimization was performed on Tesseract, the MIT Solar Electric Vehicle Team's 2003-2005 solar car using Wind Tunnel 8 at Jacobs/Sverdrup Drivability Test Facility in Allen Park, MI. These tests include angle ...

Augenbergs, Peteris K

2006-01-01T23:59:59.000Z

183

Reduced-order aerodynamic models for aeroelastic control of turbomachines  

E-Print Network (OSTI)

Aeroelasticity is a critical consideration in the design of gas turbine engines, both for stability and forced response. Current aeroelastic models cannot provide high-fidelity aerodynamics in a form suitable for design ...

Willcox, Karen Elizabeth

184

Test, Evaluation, and Demonstration of Practical Devices/Systems to Reduce Aerodynamic Drag of Tractor/Semitrailer Combination Unit Trucks  

DOE Green Energy (OSTI)

Class 8 heavy-duty trucks account for over three-quarters of the total diesel fuel used by commercial trucks (trucks with GVWRs more than 10,000 pounds) in the United States each year. At the highway speeds at which these trucks travel (i.e., 60 mph or greater), aerodynamic drag is a major part of total horsepower needed to move the truck down the highway, Reductions in aerodynamic drag can yield measurable benefits in fuel economy through the use of relatively inexpensive and simple devices. The goal of this project was to examine a number of aerodynamic drag reduction devices and systems and determine their effectiveness in reducing aerodynamic drag of Class 8 tractor/semitrailer combination-units, thus contributing to DOE's goal of reducing transportation petroleum use. The project team included major heavy truck manufacturers in the United States, along with the management and industry expertise of the Truck Manufacturers Association as the lead investigative organization. The Truck Manufacturers Association (TMA) is the national trade association representing the major North American manufacturers of Class 6-8 trucks (GVWRs over 19,500 lbs). Four major truck manufacturers participated in this project with TMA: Freightliner LLC; International Truck and Engine Corporation; Mack Trucks Inc.; and Volvo Trucks North America, Inc. Together, these manufacturers represent over three-quarters of total Class 8 truck sales in the United States. These four manufacturers pursued complementary research efforts as part of this project. The project work was separated into two phases conducted over a two-year period. In Phase I, candidate aerodynamic devices and systems were screened to focus research and development attention on devices that offered the most potential. This was accomplished using full-size vehicle tests, scale model tests, and computational fluid dynamics analyses. In Phase II, the most promising devices were installed on full-size trucks and their effect on fuel economy was determined, either through on-road testing or full-size wind tunnel testing. All of the manufacturers worked with devices and systems that offer practical solutions to reduce aerodynamic drag, accounting for functionality, durability, cost effectiveness, reliability, and maintainability. The project team members and their roles and responsibilities are shown in Figure 2-1. Figure 2-2 shows the Phase I and II project schedules for all four projects and associated management activities.

Scott Smith; Karla Younessi; Matt Markstaller; Dan Schlesinger; Bhaskar Bhatnagar; Donald Smith; Bruno Banceu; Ron Schoon; V.K. Sharma; Mark Kachmarsky; Srikant Ghantae; Michael Sorrels; Conal Deedy; Justin Clark; Skip Yeakel; Michael D. Laughlin; Charlotte Seigler; Sidney Diamond

2007-04-30T23:59:59.000Z

185

Side-by-Side Comparison of Particle Count and Mass Concentration  

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

Side-by-Side Comparison of Particle Count and Mass Concentration Side-by-Side Comparison of Particle Count and Mass Concentration Measurements in a Residence Title Side-by-Side Comparison of Particle Count and Mass Concentration Measurements in a Residence Publication Type Report Year of Publication 2011 Authors Chan, Wanyu R., and Federico Noris Publisher Lawrence Berkeley National Laboratory City Berkeley Keywords energy analysis and environmental impacts department Abstract Particulate matter (PM) is a contaminant of concern in many indoor environments, including residential and commercial buildings. Health guidelines for exposure to particles are in units of mass concentrations. Relative to time-integrated mass measurements collected on filters, real-time particle counters are less time-consuming to operate. Studies found reasonable correlation between these two measurement techniques, but agreement may vary in different sampling environments, and depends on the instruments used. We performed a side-by-side comparison of particle counts and mass concentrations estimated by three types of real-time instruments: MetOne BT-637 optical particle counter (OPC), TSI DustTrak aerosol monitor, and TSI aerodynamic particle sizer (APS) spectrometer. In addition to these real-time instruments, time-integrated particle mass was also collected using PM2.5 and PM10 Personal Environmental Monitors (PEMs) manufactured by SKC. Sampling was conducted for two consecutive days in an occupied single-family house in Berkeley, California. Concentration profiles had similar trends, with DustTraks reporting higher particle mass concentrations, partially explained by the density value assumed in the calibration. We made assumptions for particle size and density to calculate the PM2.5 and PM10 mass concentrations for the MetOne and APS, and compared with the filter-based measurements. Despite uncertainties and assumptions, there was generally good agreement for the different methods.

186

Generation of concentration density maxima of small dispersive coal dust particles in horizontal iodine air filter at air-dust aerosol blow  

E-Print Network (OSTI)

The spatial distributions of the small dispersive coal dust particles with the nano and micro sizes in the granular filtering medium with the cylindrical coal granules in the absorber in the horizontal iodine air filter during its long term operation at the nuclear power plant are researched. It is shown that the concentration density maxima of the small dispersive coal dust particles appear in the granular filtering medium with the cylindrical coal absorbent granules in the horizontal iodine air filter at an action by the air dust aerosol blow. The comparison of the measured aerodynamic resistances of the horizontal and vertical iodine air filters is conducted. The main conclusion is that the magnitude of the aerodynamic resistance of the horizontal iodine air filters is much smaller in comparison with the magnitude of the aerodynamic resistance of the vertical iodine air filters at the same loads of the air dust aerosol volumes. It is explained that the direction of the air dust aerosol blow and the direction of the gravitation force in the horizontal iodine air filter are orthogonal, hence the effective accumulation of the small dispersive coal dust particles takes place at the bottom of absorber in the horizontal iodine air filter. It is found that the air dust aerosol stream flow in the horizontal iodine air filter is not limited by the appearing structures, made of the precipitated small dispersive coal dust particles, in distinction from the vertical iodine air filter, in the process of long term operation of the iodine air filters at the nuclear power plant.

I. M. Neklyudov; O. P. Ledenyov; L. I. Fedorova; P. Ya. Poltinin

2013-06-11T23:59:59.000Z

187

Four-stage computational technology with adaptive numerical methods for computational aerodynamics  

Science Conference Proceedings (OSTI)

Computational aerodynamics is a key technology in aircraft design which is ahead of physical experiment and complements it. Of course all three components of computational modeling are actively developed: mathematical models of real aerodynamic processes

2012-01-01T23:59:59.000Z

188

ACARS Aerodynamic (Research Incorporated) Communication and Recording System  

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

ix ix Acrononyms and Abbreviations Acronyms and Abbreviations ACARS Aerodynamic (Research Incorporated) Communication and Recording System ACSYS Arctic Climate System Study AER Atmospheric Environmental Research, Inc. AERI Atmospheric Emitted Radiance Interferometer AFOSR Air Force Office of Scientific Research AGARD Advisory Group for Aerospace Research and Development ALFA AER Local Forecast and Assimilation (model) AMIP Atmospheric Model Intercomparison Project ARCS Atmosphere Radiation and Cloud Stations ARCSS Arctic System Science (NSF) ARCSYM Arctic Regional Climate System Model ARINC Aerodynamic Research Incorporated Communication ARM Atmospheric Radiation Measurement program AS anvil stratus ASTER Atmosphere-Surface Turbulent Exchange Research ASTEX Altantic Stratocumulus Transition EXperiment

189

Aerodynamic performance measurements of a film-cooled turbine stage  

E-Print Network (OSTI)

The goal of this research is to measure the aerodynamic performance of a film-cooled turbine stage and to quantify the loss caused by film-cooling. A secondary goal of the research is to provide a detailed breakdown of the ...

Keogh, Rory (Rory Colm), 1968-

2001-01-01T23:59:59.000Z

190

Plasma Aerodynamic Control Effectors for Improved Wind Turbine Performance  

DOE Green Energy (OSTI)

Orbital Research Inc is developing an innovative Plasma Aerodynamic Control Effectors (PACE) technology for improved performance of wind turbines. The PACE system is aimed towards the design of "smart" rotor blades to enhance energy capture and reduce aerodynamic loading and noise using flow-control. The PACE system will provide ability to change aerodynamic loads and pitch distribution across the wind turbine blade without any moving surfaces. Additional benefits of the PACE system include reduced blade structure weight and complexity that should translate into a substantially reduced initial cost. During the Phase I program, the ORI-UND Team demonstrated (proof-of-concept) performance improvements on select rotor blade designs using PACE concepts. Control of both 2-D and 3-D flows were demonstrated. An analytical study was conducted to estimate control requirements for the PACE system to maintain control during wind gusts. Finally, independent laboratory experiments were conducted to identify promising dielectric materials for the plasma actuator, and to examine environmental effects (water and dust) on the plasma actuator operation. The proposed PACE system will be capable of capturing additional energy, and reducing aerodynamic loading and noise on wind turbines. Supplementary benefits from the PACE system include reduced blade structure weight and complexity that translates into reduced initial capital costs.

Mehul P. Patel; Srikanth Vasudevan; Robert C. Nelson; Thomas C. Corke

2008-08-01T23:59:59.000Z

191

Exponential Size Distributions for Snow  

Science Conference Proceedings (OSTI)

Using airborne data from several recent field projects, the authors have taken another look at the properties of exponential ice particle size distributions (PSDs) when the PSDs are broad. Two primary questions are addressed: for what ranges of ...

Andrew J. Heymsfield; Paul Field; Aaron Bansemer

2008-12-01T23:59:59.000Z

192

Chemistry of airborne particles from metallurgical processing  

E-Print Network (OSTI)

Airborne particles fall into one of three size ranges. The nucleation range consists of nanoparticles created from vapor atom collisions. The decisive parameter for particle size and composition is the supercooling of the ...

Jenkins, Neil Travis, 1973-

2003-01-01T23:59:59.000Z

193

NISTIR 7097 Particle Size Analysis by Laser  

E-Print Network (OSTI)

kind (solid, liquid, gas) are dispersed in a continuous phase of a different composition or state; more into a continuous medium. dispersion medium A continuous liquid or gas phase into which a powder is dispersed prior that powders be dispersed prior to analysis by LDS; dispersion efficiency will depend on factors such as solids

194

Size Effects  

Science Conference Proceedings (OSTI)

Mar 5, 2013 ... An Explanation of the Power-Exponent in the Size Effect on Strength in ... in terms of the Taylor-type resistance in the dislocation network in the specimen. ... hysteresis and loss in pseudoelasticity with decrease in sample size.

195

An Aerodynamic Design Technique For Optimizing Fan Blade Spacing  

E-Print Network (OSTI)

INTRODUCTION Aerodynamic shape optimization involves designing the most efficient shapes of bodies that move through fluids. An optimization algorithm perturbs the shape of an airfoil until it finds the shape which best exhibits a given design objective. For an inverse design technique, this objective is a prescribed aerodynamic distribution, usually the surface pressure distribution. Liebeck pressure distributions [1], for example, have been demonstrated to generate airfoils with high lift to drag ratios. When designing fans, consideration must be given not only to the shape of the fan blades, but also to the distance separating the fan blades. This spacing is defined by the pitch/chord ratio t/l, where the pitch, t, is the distance between fan blades, and the chord, l, is the length of each fan blade. In this work, an inverse algorithm is developed, then used to design fan blade shapes and to find the optimal blade spacing.

T. Rogalsky; R.W. Derksen; Rt N; Rt N; S. Kocabiyik

1999-01-01T23:59:59.000Z

196

Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD  

DOE Green Energy (OSTI)

An investigation was conducted into the capabilities and accuracy of a representative computational fluid dynamics code to predict the flow field and aerodynamic characteristics of typical wind-turbine airfoils. Comparisons of the computed pressure and aerodynamic coefficients were made with wind tunnel data. This work highlights two areas in CFD that require further investigation and development in order to enable accurate numerical simulations of flow about current generation wind-turbine airfoils: transition prediction and turbulence modeling. The results show that the laminar-to turbulent transition point must be modeled correctly to get accurate simulations for attached flow. Calculations also show that the standard turbulence model used in most commercial CFD codes, the k-e model, is not appropriate at angles of attack with flow separation. 14 refs., 28 figs., 4 tabs.

Wolfe, W.P. [Sandia National Labs., Albuquerque, NM (United States); Ochs, S.S. [Iowa State Univ., Ames, IA (United States). Aerospace Engineering Dept.

1997-09-01T23:59:59.000Z

197

Particle analysis in an acoustic cytometer  

SciTech Connect

The present invention is a method and apparatus for acoustically manipulating one or more particles. Acoustically manipulated particles may be separated by size. The particles may be flowed in a flow stream and acoustic radiation pressure, which may be radial, may be applied to the flow stream. This application of acoustic radiation pressure may separate the particles. In one embodiment, the particles may be separated by size, and as a further example, the larger particles may be transported to a central axis.

Kaduchak, Gregory; Ward, Michael D

2012-09-18T23:59:59.000Z

198

Sizing and burn time measurements of micron-sized metal powders  

SciTech Connect

Detailed ignition and combustion mechanisms are needed to develop optimized propellant and energetic formulations using micron-sized metal powders, such as aluminum. Combustion researchers have traditionally used relatively coarse metal particles to characterize the burn time dependence on particle size. However, measurements of burn times for particles below 10 {mu}m in diameter are still needed for aluminum powders and other metal fuels. The apparatus described here sizes the particles just before the ignition event, providing a direct correlation between individual particle size and its burn time. Two lasers were utilized: a 785 nm laser diode for sizing the particles and a 125 W CO{sub 2} laser for particle ignition. The particles crossed the 785 nm laser beam just before crossing the CO{sub 2} laser beam. The particle size was determined from the amplitude of the scattered 785 nm light pulse. The burn time was determined from the duration of the visible light emission produced from the ignited particle. The in situ measured particle size distributions compared well with the size distributions measured for the same powders by a commercial instrument using low angle laser light scattering. Our measurements with two nominally spherical aluminum powders, suggest that the burn times increase from 0.5 to {approx}2.5 ms as the particle diameters increase from 3 to 8 {mu}m.

Gill, Robert J.; Mohan, Salil; Dreizin, Edward L. [New Jersey Institute of Technology Newark, New Jersey 07102 (United States)

2009-06-15T23:59:59.000Z

199

ARM - Measurement - Cloud droplet size  

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

droplet size droplet size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud droplet size Linear size (e.g. radius or diameter) of a cloud particle Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments CPI : Cloud Particle Imager CVI-AIR : Counterflow Virtual Impactor MIRAI : JAMSTEC Research Vessel Mirai PDI : Phase Doppler Interferometer UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments SPEC-CPI : Stratton Park Engineering Company - Cloud particle imager

200

Single Particle Difraction at FLASH  

SciTech Connect

Single-pulse coherent diffraction patterns have been collected from randomly injected single particles with a soft X-ray free-electron laser (FEL). The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of the object before that object turns into a plasma and explodes. A diffraction pattern of a single particle will only be recorded when the particle arrival into the FEL interaction region coincides with FEL pulse arrival and detector integration. The properties of the experimental apparatus coinciding with these three events set the data acquisition rate. For our single particle FLASH diffraction imaging experiments: (1) an aerodynamic lens stack prepared a particle beam that consisted of particles moving at 150-200 m/s positioned randomly in space and time, (2) the 10 fs long FEL pulses were delivered at a fixed rate, and (3) the detector was set to integrate and readout once every two seconds. The effect of these experimental parameters on the rate of data acquisition using randomly injected particles will be discussed. Overall, the ultrashort FEL pulses do not set the limit of the data acquisition, more important is the effective interaction time of the particle crossing the FEL focus, the pulse sequence structure and the detector readout rate. Example diffraction patterns of randomly injected ellipsoidal iron oxide nanoparticles in different orientations are presented. This is the first single particle diffraction data set of identical particles in different orientations collected on a shot-to-shot basis. This data set will be used to test algorithms for recovering 3D structure from single particle diffraction.

Bogan, M.; Boutet, S.; Starodub, Dmitri; Decorwin-Martin, Philippe; /SLAC; Chapman, H.; Bajt, S.; Schulz, J.; /DESY; Hajdu, Janos; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; /Uppsala U.; Marchesini, Stefano; /LBL, Berkeley; Barty, Anton; Benner, W.Henry; Frank, Matthias; Hau-Riege, Stefan P.; Woods, Bruce; /LLNL, Livermore; Rohner, Urs; /Tofwerk AG, Thun

2010-06-11T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Apparatus for measuring particle properties  

DOE Patents (OSTI)

An apparatus for determining particle properties from detected light scattered by the particles. The apparatus uses a light beam with novel intensity characteristics to discriminate between particles that pass through the beam and those that pass through an edge of the beam. The apparatus can also discriminate between light scattered by one particle and light scattered by multiple particles. The particle's size can be determined from the intensity of the light scattered. The particle's velocity can be determined from the elapsed time between various intensities of the light scattered.

Rader, Daniel J. (Albuquerque, NM); Castaneda, Jaime N. (Albuquerque, NM); Grasser, Thomas W. (Albuquerque, NM); Brockmann, John E. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

202

IEA Wind Annex XX: HAWT Aerodynamics and Models from Wind Tunnel Measurements; Final Report  

DOE Green Energy (OSTI)

This work characterizes undocumented physical relationships that govern aerodynamic force time variations that take place in connection with rotational augmentation on rotating wind turbine blades.

Schreck, S.

2008-12-01T23:59:59.000Z

203

Unsteady Aerodynamics Experiment Phase VI: Wind Tunnel Test Configurations and Available Data Campaigns  

DOE Green Energy (OSTI)

The primary objective of the insteady aerodynamics experiment was to provide information needed to quantify the full-scale, three-dimensional aerodynamic behavior of horizontal-axis wind turbines. This report is intended to familiarize the user with the entire scope of the wind tunnel test and to support the use of the resulting data.

Hand, M. M.; Simms, D. A.; Fingersh, L. J.; Jager, D. W.; Cotrell, J. R.; Schreck, S.; Larwood, S. M.

2001-12-01T23:59:59.000Z

204

Study on Aerodynamic Design of Horizontal Axis Wind Turbine Generator System  

Science Conference Proceedings (OSTI)

In this paper the choosing principles of design parameters and multi-airfoils in horizontal axis wind turbine (HAWT) generator system aerodynamic design are introduced. On the basis of the comparison analysis of wind turbine aerodynamic design method ... Keywords: Schmitz, airfoil, partial load, horizontal axis wind turbine (HAWT), blade tip speed ratio (BTSR)

Li Dong; Mingfu Liao; Yingfeng Li; Xiaoping Song; Ke Xu

2009-10-01T23:59:59.000Z

205

25th AIAA Applied Aerodynamics Conference 25 -28 June 2007, Miami, FL AIAA 2007-4442  

E-Print Network (OSTI)

25th AIAA Applied Aerodynamics Conference 25 - 28 June 2007, Miami, FL AIAA 2007-4442 Copyright , Diego Saer3 and Ge-Cheng Zha4 University of Miami, Coral Gables, Florida 33124 A flying wing personal and Aerospace Engineering A #12;25th AIAA Applied Aerodynamics Conference 25 - 28 June 2007, Miami, FL AIAA 2007

Zha, Gecheng

206

Computationally fast harmonic balance methods for unsteady aerodynamic predictions of helicopter rotors  

Science Conference Proceedings (OSTI)

A harmonic balance technique for the analysis of unsteady flows about helicopter rotors in forward flight and hover is presented in this paper. The aerodynamics of forward flight are highly nonlinear, with transonic flow on the advancing blade, subsonic ... Keywords: Computational fluid dynamics, Frequency-domain methods, Harmonic balance technique, Helicopter rotors, Unsteady aerodynamics

Kivanc Ekici; Kenneth C. Hall; Earl H. Dowell

2008-06-01T23:59:59.000Z

207

Wind turbine aerodynamics using ALE---VMS: validation and the role of weakly enforced boundary conditions  

Science Conference Proceedings (OSTI)

In this article we present a validation study involving the full-scale NREL Phase VI two-bladed wind turbine rotor. The ALE---VMS formulation of aerodynamics, based on the Navier---Stokes equations of incompressible flows, is employed in conjunction ... Keywords: ALE---VMS, Finite elements, NREL 5MW offshore, NREL Phase VI, Weakly enforced essential boundary conditions, Wind turbine aerodynamics

Ming-Chen Hsu; Ido Akkerman; Yuri Bazilevs

2012-10-01T23:59:59.000Z

208

Wind turbine trailing-edge aerodynamic brake design  

DOE Green Energy (OSTI)

This report describes the design of a centrifugally actuated aerodynamic-overspeed device for a horizontal-axis wind turbine. The device will meet the following criteria; (1) It will be effective for airfoil angles of attack 0{degrees} to 45{degrees}. (2) It will be stowed inside the blade profile prior to deployment. (3) It will be capable of offsetting the positive torque produced by the overall blade. (4) Hinge moments will be minimized to lower actuator loads and cost. (5) It will be evaluated as a potential power modulating active rotor-control system. A literature review of aerodynamic braking devices was conducted. Information from the literature review was used to conceptualize the most effective devices for subsequent testing and design. Wind-tunnel test data for several braking devices are presented in this report. Using the data for the most promising configuration, a preliminary design was developed for a MICON 65/13 wind turbine with Phoenix 7.9-m rotor blades.

Quandt, G.

1996-01-01T23:59:59.000Z

209

Real-time Shape-based Particle Separation and Detailed In-situ Particle Shape Characterization  

SciTech Connect

Particle shape is an important attribute that is very difficult to characterize. We present a new portable system that offers, for the first time, the opportunity to separate particles with different shapes and characterize their chemical and physical properties, including their dynamic shape factors (DSFs) in the transition and free-molecular regimes, with high precision, in-situ, and in real-time. The system uses a new generation aerosol particle mass analyzer (APM) to classify particles based on their masses and transport them to a differential mobility analyzer (DMA) that is used to select particles of one charge, one mass, and one shape. These highly uniform particles are ready for use and/or characterization by any application or analytical tool. We combine APM and DMA with our single particle mass spectrometer, SPLAT II, to form the ADS, and demonstrate its utility to measure in real-time individual particle compositions and vacuum aerodynamic diameters to yield, for each selected shape, particle DSFs in two flow regimes. We apply the ADS to characterize aspherical ammonium sulfate and NaCl particles and show that both particle types have wide distribution of particle shapes with DSFs from nearly 1 to 1.5.

Beranek, Josef; Imre, D.; Zelenyuk, Alla

2012-02-07T23:59:59.000Z

210

Vacuum chamber with a supersonic flow aerodynamic window  

DOE Patents (OSTI)

A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Hanson, Clark L. (Livermore, CA)

1982-01-01T23:59:59.000Z

211

Vacuum chamber with a supersonic-flow aerodynamic window  

DOE Patents (OSTI)

A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Hanson, C.L.

1980-10-14T23:59:59.000Z

212

Aerodynamic testing of a rotating wind turbine blade  

DOE Green Energy (OSTI)

Aerodynamic, load, flow-visualization, and inflow measurements were taken on a downwind horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor recorded video images of tufts attached to the low-pressure side of the blade. Strain gages, mounted every 10% of the blade's span, provided load and pressure measurements. Pressure taps at 32 chordwise positions recorded pressure distributions. Wind inflow was measured via a vertical-plane array of anemometers located 10 m upwind. The objectives of the test were to address whether airfoil pressure distributions measured on a rotating blade differed from those measured in the wind tunnel, if radial flow near or in the boundary layer of the airfoil affected pressure distributions, if dynamic stall could result in increased dynamic loads, and if the location of the separation boundary measured on the rotating blade agreed with that measured in two-dimensional flow in the wind tunnel. 6 refs., 9 figs., 1 tab.

Butterfield, C.P.; Nelsen, E.N.

1990-01-01T23:59:59.000Z

213

Aeroacoustics and aerodynamic performance of a rotor with flatback airfoils.  

Science Conference Proceedings (OSTI)

The aerodynamic performance and aeroacoustic noise sources of a rotor employing flatback airfoils have been studied in field test campaign and companion modeling effort. The field test measurements of a sub-scale rotor employing nine meter blades include both performance measurements and acoustic measurements. The acoustic measurements are obtained using a 45 microphone beamforming array, enabling identification of both noise source amplitude and position. Semi-empirical models of flatback airfoil blunt trailing edge noise are developed and calibrated using available aeroacoustic wind tunnel test data. The model results and measurements indicate that flatback airfoil noise is less than drive train noise for the current test turbine. It is also demonstrated that the commonly used Brooks, Pope, and Marcolini model for blunt trailing edge noise may be over-conservative in predicting flatback airfoil noise for wind turbine applications.

Paquette, Joshua A.; Barone, Matthew Franklin; Christiansen, Monica (Pennsylvania State University, State College, PA); Simley, Eric (University of Colorado, Boulder, CO)

2010-06-01T23:59:59.000Z

214

Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer  

DOE Green Energy (OSTI)

The gas turbine has the potential for power production at the highest possible efficiency. The challenge is to ensure that gas turbines operate at the optimum efficiency so as to use the least fuel and produce minimum emissions. A key component to meeting this challenge is the turbine. Turbine performance, both aerodynamics and heat transfer, is one of the barrier advanced gas turbine development technologies. This is a result of the complex, highly three-dimensional and unsteady flow phenomena in the turbine. Improved turbine aerodynamic performance has been achieved with three-dimensional highly-loaded airfoil designs, accomplished utilizing Euler or Navier-Stokes Computational Fluid Dynamics (CFD) codes. These design codes consider steady flow through isolated blade rows. Thus they do not account for unsteady flow effects. However, unsteady flow effects have a significant impact on performance. Also, CFD codes predict the complete flow field. The experimental verification of these codes has traditionally been accomplished with point data - not corresponding plane field measurements. Thus, although advanced CFD predictions of the highly complex and three-dimensional turbine flow fields are available, corresponding data are not. To improve the design capability for high temperature turbines, a detailed understanding of the highly unsteady and three-dimensional flow through multi-stage turbines is necessary. Thus, unique data are required which quantify the unsteady three-dimensional flow through multi-stage turbine blade rows, including the effect of the film coolant flow. Also, as design CFD codes do not account for unsteady flow effects, the next logical challenge and the current thrust in CFD code development is multiple-stage analyses that account for the interactions between neighboring blade rows. Again, to verify and or direct the development of these advanced codes, complete three-dimensional unsteady flow field data are needed.

Fleeter, S.; Lawless, P.B. [Purdue Univ., West Lafayette, IN (United States). School of Mechanical Engineering

1995-12-31T23:59:59.000Z

215

Inertial Particle Dynamics in a Hurricane  

E-Print Network (OSTI)

The motion of inertial (i.e., finite-size) particles is analyzed in a three-dimensional unsteady simulation of Hurricane Isabel. As established recently, the long-term dynamics of inertial particles in a fluid is governed ...

Sapsis, Themistoklis

216

Particle separation  

DOE Patents (OSTI)

Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

Moosmuller, Hans (Reno, NV); Chakrabarty, Rajan K. (Reno, NV); Arnott, W. Patrick (Reno, NV)

2011-04-26T23:59:59.000Z

217

Optical double-slit particle measuring system  

DOE Patents (OSTI)

A method for in situ measurement of particle size is described. The size information is obtained by scanning an image of the particle across a double-slit mask and observing the transmitted light. This method is useful when the particle size of primary interest is 3..mu..m and larger. The technique is well suited to applications in which the particles are non-spherical and have unknown refractive index. It is particularly well suited to high temperature environments in which the particle incandescence provides the light source.

Tichenor, D.A.; Wang, J.C.F.; Hencken, K.R.

1982-03-25T23:59:59.000Z

218

Advanced Electric Systems and Aerodynamics for Efficiency Improvements in Heavy Duty Trucks  

Science Conference Proceedings (OSTI)

The Advanced Electric Systems and Aerodynamics for Efficiency Improvements in Heavy Duty Trucks program (DE-FC26-04NT42189), commonly referred to as the AES program, focused on areas that will primarily benefit fuel economy and improve heat rejection while driving over the road. The AES program objectives were to: (1) Analyze, design, build, and test a cooling system that provided a minimum of 10 percent greater heat rejection in the same frontal area with no increase in parasitic fan load. (2) Realize fuel savings with advanced power management and acceleration assist by utilizing an integrated starter/generator (ISG) and energy storage devices. (3) Quantify the effect of aerodynamic drag due to the frontal shape mandated by the area required for the cooling system. The program effort consisted of modeling and designing components for optimum fuel efficiency, completing fabrication of necessary components, integrating these components into the chassis test bed, completing controls programming, and performance testing the system both on a chassis dynamometer and on the road. Emission control measures for heavy-duty engines have resulted in increased engine heat loads, thus introducing added parasitic engine cooling loads. Truck electrification, in the form of thermal management, offers technological solutions to mitigate or even neutralize the effects of this trend. Thermal control offers opportunities to avoid increases in cooling system frontal area and forestall reduced fuel economy brought about by additional aerodynamic vehicle drag. This project explored such thermal concepts by installing a 2007 engine that is compliant with current regulations and bears additional heat rejection associated with meeting these regulations. This newer engine replaced the 2002 engine from a previous project that generated less heat rejection. Advanced power management, utilizing a continuously optimized and controlled power flow between electric components, can offer additional fuel economy benefits to the heavy-duty trucking industry. Control software for power management brings added value to the power distribution and energy storage architecture on board a truck with electric accessories and an ISG. The research team has built upon a previous truck electrification project, formally, 'Parasitic Energy Loss Reduction and Enabling Technologies for Class 7/8 Trucks', DE-FC04-2000AL6701, where the fundamental concept of electrically-driven accessories replacing belt/gear-driven accessories was demonstrated on a Kenworth T2000 truck chassis. The electrical accessories, shown in Figure 1, were controlled to provide 'flow on demand' variable-speed operation and reduced parasitic engine loads for increased fuel economy. These accessories also provided solutions for main engine idle reduction in long haul trucks. The components and systems of the current project have been integrated into the same Kenworth T2000 truck platform. Reducing parasitic engine loading by decoupling accessory loads from the engine and driving them electrically has been a central concept of this project. Belt or gear-driven engine accessories, such as water pump, air conditioning compressor, or air compressor, are necessarily tied to the engine speed dictated by the current vehicle operating conditions. These conventional accessory pumps are sized to provide adequate flow or pressure at low idle or peak torque speeds, resulting in excess flow or pressure at cruising or rated speeds. The excess flow is diverted through a pressure-minimizing device such as a relief valve thereby expending energy to drive unnecessary and inefficient pump operation. This inefficiency causes an increased parasitic load to the engine, which leads to a loss of usable output power and decreased fuel economy. Controlling variable-speed electric motors to provide only the required flow or pressure of a particular accessory system can yield significant increases in fuel economy for a commercial vehicle. Motor loads at relatively high power levels (1-5 kW, or higher) can be efficiently provided

Larry Slone; Jeffrey Birkel

2007-10-31T23:59:59.000Z

219

Advanced Electric Systems and Aerodynamics for Efficiency Improvements in Heavy Duty Trucks  

DOE Green Energy (OSTI)

The Advanced Electric Systems and Aerodynamics for Efficiency Improvements in Heavy Duty Trucks program (DE-FC26-04NT42189), commonly referred to as the AES program, focused on areas that will primarily benefit fuel economy and improve heat rejection while driving over the road. The AES program objectives were to: (1) Analyze, design, build, and test a cooling system that provided a minimum of 10 percent greater heat rejection in the same frontal area with no increase in parasitic fan load. (2) Realize fuel savings with advanced power management and acceleration assist by utilizing an integrated starter/generator (ISG) and energy storage devices. (3) Quantify the effect of aerodynamic drag due to the frontal shape mandated by the area required for the cooling system. The program effort consisted of modeling and designing components for optimum fuel efficiency, completing fabrication of necessary components, integrating these components into the chassis test bed, completing controls programming, and performance testing the system both on a chassis dynamometer and on the road. Emission control measures for heavy-duty engines have resulted in increased engine heat loads, thus introducing added parasitic engine cooling loads. Truck electrification, in the form of thermal management, offers technological solutions to mitigate or even neutralize the effects of this trend. Thermal control offers opportunities to avoid increases in cooling system frontal area and forestall reduced fuel economy brought about by additional aerodynamic vehicle drag. This project explored such thermal concepts by installing a 2007 engine that is compliant with current regulations and bears additional heat rejection associated with meeting these regulations. This newer engine replaced the 2002 engine from a previous project that generated less heat rejection. Advanced power management, utilizing a continuously optimized and controlled power flow between electric components, can offer additional fuel economy benefits to the heavy-duty trucking industry. Control software for power management brings added value to the power distribution and energy storage architecture on board a truck with electric accessories and an ISG. The research team has built upon a previous truck electrification project, formally, 'Parasitic Energy Loss Reduction and Enabling Technologies for Class 7/8 Trucks', DE-FC04-2000AL6701, where the fundamental concept of electrically-driven accessories replacing belt/gear-driven accessories was demonstrated on a Kenworth T2000 truck chassis. The electrical accessories, shown in Figure 1, were controlled to provide 'flow on demand' variable-speed operation and reduced parasitic engine loads for increased fuel economy. These accessories also provided solutions for main engine idle reduction in long haul trucks. The components and systems of the current project have been integrated into the same Kenworth T2000 truck platform. Reducing parasitic engine loading by decoupling accessory loads from the engine and driving them electrically has been a central concept of this project. Belt or gear-driven engine accessories, such as water pump, air conditioning compressor, or air compressor, are necessarily tied to the engine speed dictated by the current vehicle operating conditions. These conventional accessory pumps are sized to provide adequate flow or pressure at low idle or peak torque speeds, resulting in excess flow or pressure at cruising or rated speeds. The excess flow is diverted through a pressure-minimizing device such as a relief valve thereby expending energy to drive unnecessary and inefficient pump operation. This inefficiency causes an increased parasitic load to the engine, which leads to a loss of usable output power and decreased fuel economy. Controlling variable-speed electric motors to provide only the required flow or pressure of a particular accessory system can yield significant increases in fuel economy for a commercial vehicle. Motor loads at relatively high power levels (1-5 kW, or higher) can be efficiently provided

Larry Slone; Jeffrey Birkel

2007-10-31T23:59:59.000Z

220

Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3-D Endwall Contouring  

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

Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3 Blade Cascade with 3 - - D D Endwall Endwall Contouring Contouring Principal Investigator Principal Investigator Sumanta Acharya, Professor Sumanta Acharya, Professor Louisiana State University, Baton Rouge, Louisiana Louisiana State University, Baton Rouge, Louisiana Collaborators Collaborators Gazi Mahmood, Ph.D., Research Asqociate Gazi Mahmood, Ph.D., Research Asqociate Arun Saha, Ph.D., Research Associate Arun Saha, Ph.D., Research Associate Ross Gustafson, M.S. student Ross Gustafson, M.S. student SCIES Project 02 SCIES Project 02 - - 01 01 - - SR098 SR098 DOE COOPERATIVE AGREEMENT DE DOE COOPERATIVE AGREEMENT DE - - FC26 FC26 - - 02NT41431 02NT41431 Tom J. George, Program Manager, DOE/NETL

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

A Comparison of Sensible and Latent Heat Flux Calculations Using the Bowen Ratio and Aerodynamic Methods  

Science Conference Proceedings (OSTI)

An analysis technique is outlined that calculates the sensible and latent heat fluxes by the Bowen ratio and aerodynamic methods, using profile measurements at any number of heights. Field measurements at two sites near Churchill, Manitoba, ...

David H. Halliwell; Wayne R. Rouse

1989-08-01T23:59:59.000Z

222

Aerodynamic Properties of Urban Areas Derived from Analysis of Surface Form  

Science Conference Proceedings (OSTI)

Several methods to determine the aerodynamic characteristics of a site through analysis of its surface form (morphometry) are considered in relation to cities. The measures discussed include zero-plane displacement length (zd), roughness length (...

C. S. B. Grimmond; T. R. Oke

1999-09-01T23:59:59.000Z

223

LES Analysis of the Aerodynamic Surface Properties for Turbulent Flows over Building Arrays with Various Geometries  

Science Conference Proceedings (OSTI)

This paper describes aerodynamic roughness properties for turbulent flows over various building arrays that represent realistic urban surface geometries. First, building morphological characteristics such as roughness density ?f and building ...

Hiromasa Nakayama; Tetsuya Takemi; Haruyasu Nagai

2011-08-01T23:59:59.000Z

224

Derivation of Effective Aerodynamic Surface Roughness in Urban Areas from Airborne Lidar Terrain Data  

Science Conference Proceedings (OSTI)

An automated technique was developed that uses only airborne lidar terrain data to derive the necessary parameters for calculation of effective aerodynamic surface roughness in urban areas. The technique provides parameters for geometric models ...

Donald E. Holland; Judith A. Berglund; Joseph P. Spruce; Rodney D. McKellip

2008-10-01T23:59:59.000Z

225

Prediction of loaded airfoil unsteady aerodynamic gust response by a locally analytical method  

Science Conference Proceedings (OSTI)

A complete first order model is formulated to analyze the effects of steady loading on the incompressible unsteady aerodynamics generated by a two-dimensional gust convected with the steady mean flow past an arbitrary airfoil at finite nonzero angle ...

Hsiao-Wei D. Chiang; Sanford Fleeter

1988-12-01T23:59:59.000Z

226

Which Bulk Aerodynamic Algorithms are Least Problematic in Computing Ocean Surface Turbulent Fluxes?  

Science Conference Proceedings (OSTI)

Bulk aerodynamic algorithms are needed to compute ocean surface turbulent fluxes in weather forecasting and climate models and in the development of global surface flux datasets. Twelve such algorithms are evaluated and ranked using direct ...

Michael A. Brunke; Chris W. Fairall; Xubin Zeng; Laurence Eymard; Judith A. Curry

2003-02-01T23:59:59.000Z

227

Challenges in Simulation of Aerodynamics, Hydrodynamics, and Mooring-Line Dynamics of Floating Offshore Wind Turbines  

Science Conference Proceedings (OSTI)

This paper presents the current major modeling challenges for floating offshore wind turbine design tools and describes aerodynamic and hydrodynamic effects due to rotor and platform motions and usage of non-slender support structures.

Matha, D.; Schlipf, M.; Cordle, A.; Pereira, R.; Jonkman, J.

2011-10-01T23:59:59.000Z

228

Stabilized space---time computation of wind-turbine rotor aerodynamics  

Science Conference Proceedings (OSTI)

We show how we use the Deforming-Spatial-Domain/Stabilized Space---Time (DSD/SST) formulation for accurate 3D computation of the aerodynamics of a wind-turbine rotor. As the test case, we use the NREL 5MW offshore baseline wind-turbine rotor. This class ... Keywords: DSD/SST formulation, Rotating turbulent flow, Space---time variational multiscale method, Torque values, Wind-turbine aerodynamics

Kenji Takizawa; Bradley Henicke; Tayfun E. Tezduyar; Ming-Chen Hsu; Yuri Bazilevs

2011-09-01T23:59:59.000Z

229

Computer subroutine for estimating aerodynamic blade loads on Darrieus vertical axis wind turbines. [FORCE code  

DOE Green Energy (OSTI)

An important aspect of structural design of the Darrieus rotor is the determination of aerodynamic blade loads. This report describes a load generator which has been used at Sandia for quasi-static and dynamic rotor analyses. The generator is based on the single streamtube aerodynamic flow model and is constructed as a FORTRAN IV subroutine to facilitate its use in finite element structural models. Input and output characteristics of the subroutine are described and a complete listing is attached as an appendix.

Sullivan, W. N.; Leonard, T. M.

1980-11-01T23:59:59.000Z

230

AN ENGINE EXHAUST PARTICLE SIZERTM SPECTROMETER FOR TRANSIENT EMISSION PARTICLE MEASUREMENTS  

DOE Green Energy (OSTI)

There has been increased interest in obtaining size distribution data during transient engine operation where both particle size and total number concentrations can change dramatically. Traditionally, the measurement of particle emissions from vehicles has been a compromise based on choosing between the conflicting needs of high time resolution or high particle size resolution for a particular measurement. Currently the most common technique for measuring submicrometer particle sizes is the Scanning Mobility Particle Sizer (SMPSTM) system. The SMPS system gives high size resolution but requires an aerosol to be stable over a long time period to make a particle size distribution measurement. A Condensation Particle Counter (CPC) is commonly used for fast time response measurements but is limited to measuring total concentration only. This paper describes a new instrument, the Engine Exhaust Particle SizerTM (EEPSTM) spectrometer, which has high time resolution and a reasonable size resolution. The EEPS was designed specifically for measuring engine exhaust and, like the SMPS system, uses a measurement based on electrical mobility. Particles entering the instrument are charged to a predictable level, then passed through an annular space where they are repelled outward by the voltage from a central column. When the particles reach electrodes on the outer cylindrical (a column of rings), they create a current that is measured by an electrometer on one or more of the rings. The electrometer currents are measured multiple times per second to give high time resolution. A sophisticated realtime inversion algorithm converts the currents to particle size and concentration for immediate display.

Johnson, T; Caldow, R; Pucher, A; Mirme, A; Kittelson, D

2003-08-24T23:59:59.000Z

231

AN ENGINE EXHAUST PARTICLE SIZER{trademark} SPECTROMETER FOR TRANSIENT EMISSION PARTICLE MEASUREMENTS  

DOE Green Energy (OSTI)

There has been increased interest in obtaining size distribution data during transient engine operation where both particle size and total number concentrations can change dramatically. Traditionally, the measurement of particle emissions from vehicles has been a compromise based on choosing between the conflicting needs of high time resolution or high particle size resolution for a particular measurement. Currently the most common technique for measuring submicrometer particle sizes is the Scanning Mobility Particle Sizer (SMPSTM) system. The SMPS system gives high size resolution but requires an aerosol to be stable over a long time period to make a particle size distribution measurement. A Condensation Particle Counter (CPC) is commonly used for fast time response measurements but is limited to measuring total concentration only. This paper describes a new instrument, the Engine Exhaust Particle SizerTM (EEPSTM) spectrometer, which has high time resolution and a reasonable size resolution. The EEPS was designed specifically for measuring engine exhaust and, like the SMPS system, uses a measurement based on electrical mobility. Particles entering the instrument are charged to a predictable level, then passed through an annular space where they are repelled outward by the voltage from a central column. When the particles reach electrodes on the outer cylindrical (a column of rings), they create a current that is measured by an electrometer on one or more of the rings. The electrometer currents are measured multiple times per second to give high time resolution. A sophisticated realtime inversion algorithm converts the currents to particle size and concentration for immediate display.

Johnson, T: Caldow, R; Pucher, A Mirme, A Kittelson, D

2003-08-24T23:59:59.000Z

232

Part I--A Rational Aerodynamic Design Procedure  

E-Print Network (OSTI)

'The design of a turbine stage is described in which all leading parameters (stage loading, flow coefficient, pitch/chord ratio, blade profile shape and aspect ratio) have been selected conservatively to accord with current ideas for ensuring a reasonably high level of aerodynamic efficiency. From consideration of the influence of stage loading KpAT V~ U,2, flow coefficient ~ and rotor exit swirl angle c ~ 3, the stage design was selected such that these parameters were 1.15, 0.65 and 10 degrees respectively. At the design speed of U ~ = 34 the resulting stage pressure ratio is approximately 1.65. Such a stage duty is 'light ' by aero engine standards but very comparable to much industrial gas turbine design practice. Blade spacing and profile shapes are 'finally selected in such a way as to preclude severe opposing pressure gradients on the suction surface which might result in local separation of the boundary layer from the blade surfaces. The methods applied and described for predicting blade surface velocities are simple and approximate only, and might readily be imitated by designers not wishing or able to exploit more elaborate and complex digital techniques.

M. No; D. J. L. Smith; I. H. Johnston; D. J. L. Smith; D. J. Fullbrook; D. J. L. Smith; I. H. Johnston

1967-01-01T23:59:59.000Z

233

Particle Lifetimes  

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

Reviewing Particle Lifetimes Reviewing Particle Lifetimes The lifetimes of elementary particles are statistical in nature. In a given sample, one particle might decay immediately, another in 1 nanosecond, yet another after 10 milliseconds, and still another in 50 years. What we call the lifetime is the time it takes for a sample to decay so 1/e (~30%) of the sample is left; after 2 lifetimes, 1/e2 of the sample is left, and so on. Take, for example, a sample of cosmic ray muons produced in the upper atmosphere. These muons, when observed at (relative) rest in the laboratory, have a mean lifetime T. Now, since particle decay is statistical in nature, the number of undecayed particles after a given time is a negative exponential function: N(t) = No e-t/T where N(t) is the number of muons at time t, No is the initial number of

234

PARTICLE ACCELERATOR  

DOE Patents (OSTI)

A fixed-field alternating gradient accelerator for simultaneous acceleration of two particle beams in opposite directions is described. (T.R.H.)

Ohkawa, T.

1959-06-01T23:59:59.000Z

235

On the Form of Stationary Size Distributions Established by Coagulation and Sedimentation  

Science Conference Proceedings (OSTI)

In stationary solutions of the equations for nucleation, coagulation and sedimentation, the concentration of large particles falls off more strongly than any power of particle size. The tails of stationary size distributions established by these ...

Warren H. White

1983-07-01T23:59:59.000Z

236

Observations of Precipitation Size and Fall Speed Characteristics within Coexisting Rain and Wet Snow  

Science Conference Proceedings (OSTI)

Ground-based measurements of particle size and fall speed distributions using a Particle Size and Velocity (PARSIVEL) disdrometer are compared among samples obtained in mixed precipitation (rain and wet snow) and rain in the Oregon Cascade ...

Sandra E. Yuter; David E. Kingsmill; Louisa B. Nance; Martin Löffler-Mang

2006-10-01T23:59:59.000Z

237

Distributions of Raindrop Sizes and Fall Velocities in a Semiarid Plateau Climate: Convective versus Stratiform Rains  

Science Conference Proceedings (OSTI)

Joint size and fall velocity distributions of raindrops were measured with a Particle Size and Velocity (PARSIVEL) precipitation particle disdrometer in a field experiment conducted during July and August 2007 at a semiarid continental site ...

Shengjie Niu; Xingcan Jia; Jianren Sang; Xiaoli Liu; Chunsong Lu; Yangang Liu

2010-04-01T23:59:59.000Z

238

Method for producing ceramic particles and agglomerates  

DOE Patents (OSTI)

A method for generating spherical and irregularly shaped dense particles of ceramic oxides having a controlled particle size and particle size distribution. An aerosol containing precursor particles of oxide ceramics is directed into a plasma. As the particles flow through the hot zone of the plasma, they melt, collide, and join to form larger particles. If these larger particles remain in the hot zone, they continue melting and acquire a spherical shape that is retained after they exit the hot zone, cool down, and solidify. If they exit the hot zone before melting completely, their irregular shape persists and agglomerates are produced. The size and size distribution of the dense product particles can be controlled by adjusting several parameters, the most important in the case of powder precursors appears to be the density of powder in the aerosol stream that enters the plasma hot zone. This suggests that particle collision rate is responsible for determining ultimate size of the resulting sphere or agglomerate. Other parameters, particularly the gas flow rates and the microwave power, are also adjusted to control the particle size distribution.

Phillips, Jonathan (Santa Fe, NM); Gleiman, Seth S. (Santa Fe, NM); Chen, Chun-Ku (Albuquerque, NM)

2001-01-01T23:59:59.000Z

239

Colloid Science of Metal Nanoparticle Catalysts in 2D and 3D Structures. Challenges of Nucleation, Growth, Composition, Particle Shape, Size Control and their Influence on Activity and Selectivity  

SciTech Connect

Recent breakthroughs in synthesis in nanosciences have achieved control of size and shapes of nanoparticles that are relevant for catalyst design. In this article, we review the advance of synthesis of nanoparticles, fabrication of two and three dimensional model catalyst system, characterization, and studies of activity and selectivity. The ability to synthesize monodispersed platinum and rhodium nanoparticles in the 1-10 nm range permitted us to study the influence of composition, structure, and dynamic properties of monodispersed metal nanoparticle on chemical reactivity and selectivity. We review the importance of size and shape of nanoparticles to determine the reaction selectivity in multi-path reactions. The influence of metal-support interaction has been studied by probing the hot electron flows through the metal-oxide interface in catalytic nanodiodes. Novel designs of nanoparticle catalytic systems are discussed.

Somorjai, Gabor A.; Park, Jeong Y.

2008-02-13T23:59:59.000Z

240

Quantitative organic vapor-particle sampler  

DOE Patents (OSTI)

A quantitative organic vapor-particle sampler for sampling semi-volatile organic gases and particulate components. A semi-volatile organic reversible gas sorbent macroreticular resin agglomerates of randomly packed microspheres with the continuous porous structure of particles ranging in size between 0.05-10 .mu.m for use in an integrated diffusion vapor-particle sampler.

Gundel, Lara (Berkeley, CA); Daisey, Joan M. (Walnut Creek, CA); Stevens, Robert K. (Cary, NC)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Particle deposition in ventilation ducts  

SciTech Connect

Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.

Sippola, Mark R.

2002-09-01T23:59:59.000Z

242

The Formation of Systems with Tightly-packed Inner Planets (STIPs) via Aerodynamic Drift  

E-Print Network (OSTI)

The NASA Kepler mission has revealed an abundant class of Systems with Tightly-packed Inner Planets (STIPs). The current paradigm for planet formation suggests that small planetesimals will quickly spiral into the host star due to aerodynamic drag, preventing rocky planet formation. In contrast, we find that aerodynamic drift, when acting on an ensemble of solids, can concentrate mass at short orbital periods in gaseous disks. Sublimation fronts may further aid this process. Kepler data suggest that the innermost known planets are found near the silicate sublimation zone. STIP planets should have a wide range of volatile fractions due to aerodynamic drift and H2 dissociation-driven gas accretion. We further propose that the low mass of Mars is evidence that the Solar System was once a proto-STIP.

Boley, Aaron C

2013-01-01T23:59:59.000Z

243

Calibration of the Cloud Particle Imager Probes Using Calibration Beads and Ice Crystal Analogs: The Depth of Field  

Science Conference Proceedings (OSTI)

This paper explains and develops a correction algorithm for measurement of cloud particle size distributions with the Stratton Park Engineering Company, Inc., Cloud Particle Imager (CPI). Cloud particle sizes, when inferred from images taken with ...

Paul J. Connolly; Michael J. Flynn; Z. Ulanowski; T. W. Choularton; M. W. Gallagher; K. N. Bower

2007-11-01T23:59:59.000Z

244

RESONATOR PARTICLE SEPARATOR  

DOE Patents (OSTI)

A wave guide resonator structure is described for use in separating particles of equal momentum but differing in mass and having energies exceeding one billion electron volts. The particles are those of sub-atomic size and are generally produced as a result of the bombardment of a target by a beam such as protons produced in a high-energy accelerator. In this wave guide construction, the particles undergo preferential deflection as a result of the presence of an electric field. The boundary conditions established in the resonator are such as to eliminate an interfering magnetic component, and to otherwise phase the electric field to obtain a traveling wave such as one which moves at the same speed as the unwanted particle. The latter undergoes continuous deflection over the whole length of the device and is, therefore, eliminated while the wanted particle is deflected in opposite directions over the length of the resonator and is thus able to enter an exit aperture. (AEC)

Blewett, J.P.

1962-01-01T23:59:59.000Z

245

Numerical prediction of aerodynamic characteristics of prismatic cylinder by finite element method with Spalart-Allmaras turbulence model  

Science Conference Proceedings (OSTI)

Aerodynamic characteristic of prismatic cylinders is numerically investigated by using finite element method with Spalart-Allmaras turbulence model. The developed model is verified against the available experimental and numerical results for turbulent ... Keywords: Aerodynamic characteristic, Afterbody shape, Finite element method, Prismatic cylinder, Turbulent flow, Unsteady S-A model

Yan Bao; Dai Zhou; Cheng Huang; Qier Wu; Xiang-qiao Chen

2011-02-01T23:59:59.000Z

246

Original papers: Aerodynamic analysis and CFD simulation of several cellulose evaporative cooling pads used in Mediterranean greenhouses  

Science Conference Proceedings (OSTI)

The present work makes an aerodynamic analysis and computational fluid dynamics (CFD) simulation of the four commercial models of corrugated cellulose evaporative cooling pads that are most widely used in Mediterranean greenhouses. The geometric characteristics ... Keywords: Aerodynamic analysis, CFD, Evaporative cooling, Fan and pad, Greenhouse, Pressure drop

A. Franco; D. L. Valera; A. Peña; A. M. Pérez

2011-05-01T23:59:59.000Z

247

Online Particle Physics Information - Particles & Properties...  

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

Particles & Properties Data Review of Particle Physics (RPP) A biennial comprehensive review summarizing much of the known data about the field of particle physics produced by the...

248

The Particle Adventure | Particle decays and annihiliations ...  

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

virtual particles. Virtual particles do not violate the conservation of energy. The kinetic energy plus mass of the initial decaying particle and the final decay products is...

249

The Particle Adventure | Accelerators and Particle Detectors  

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

Waves and particles The world's meterstick Mass and energy Energy-mass conversion Accelerators How to obtain particles to accelerate Accelerating particles Accelerating...

250

Review of Particle Physics  

E-Print Network (OSTI)

11. Particle Physics Education Sites . . . . . . . . .ONLINE PARTICLE PHYSICS INFORMATION 1.11. Particle Physics Education Sites . . . . . . . . . . 12.

Nakamura, Kenzo

2010-01-01T23:59:59.000Z

251

Heterogeneous mixtures of elliptical particles: Directly resolving local and global properties and responses  

Science Conference Proceedings (OSTI)

In our earlier papers, Prosperetti's seminal Physalis method for fluid flows was extended to directly resolve electric fields in finite-sized particles and to investigate accurately the mutual fluid-particle, particle-particle, and particle-boundary ... Keywords: Directly resolving particles, Discontinuous interface condition, Elliptical particles, Elongated rod-like particle, Force and torque on particles, Heterogeneous functional materials, Interactions, Local charge distribution, Orientation and anisotropy, Singularity in elliptic coordinates

Qianlong Liu; Kenneth L. Reifsnider

2013-02-01T23:59:59.000Z

252

Elementary Particles  

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

Elementary Particles Elementary Particles Elementary Particles Detectors Accelerators Visit World Labs For Children - for younger people Electric Forces & Fields For Children The Electric Force For Children Electric Force Fields For Children Charges and Fields For Children Vibrating Charges and Electromagnetic Waves Electrons For Older People The Discovery of the Electron Traveling Waves For Older People Waves and Wave-Like Motion For Children Catch the Wave For Children Vibrating Charges and Electromagnetic Waves For Children Electromagnetic Waves Standing Waves For Older People Physics 128 Lecture Standing Waves For Older People Resonance in Strings and Springs For Older People Standing Wave - 1st Harmonic For Older People Standing Wave - 2nd Harmonic Atom For Older People Bohr Atom

253

Carbon particles  

DOE Patents (OSTI)

A method and apparatus whereby small carbon particles are made by pyrolysis of a mixture of acetylene carried in argon. The mixture is injected through a nozzle into a heated tube. A small amount of air is added to the mixture. In order to prevent carbon build-up at the nozzle, the nozzle tip is externally cooled. The tube is also elongated sufficiently to assure efficient pyrolysis at the desired flow rates. A key feature of the method is that the acetylene and argon, for example, are premixed in a dilute ratio, and such mixture is injected while cool to minimize the agglomeration of the particles, which produces carbon particles with desired optical properties for use as a solar radiant heat absorber.

Hunt, Arlon J. (Oakland, CA)

1984-01-01T23:59:59.000Z

254

Trillion Particles,  

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

Trillion Trillion Particles, 120,000 cores, and 350 TBs: Lessons Learned from a Hero I/O Run on Hopper Surendra Byna ∗ , Andrew Uselton ∗ , Prabhat ∗ , David Knaak † , and Yun (Helen) He ∗ ∗ Lawrence Berkeley National Laboratory, USA. Email: {sbyna, acuselton, prabhat, yhe}@lbl.gov † Cray Inc., USA. Email: knaak@cray.com Abstract-Modern petascale applications can present a variety of configuration, runtime, and data management challenges when run at scale. In this paper, we describe our experiences in running VPIC, a large-scale plasma physics simulation, on the NERSC production Cray XE6 system Hopper. The simulation ran on 120,000 cores using ∼80% of computing resources, 90% of the available memory on each node and 50% of the Lustre scratch file system. Over two trillion particles were simulated for 23,000 timesteps, and 10 one-trillion particle dumps, each ranging between

255

A computer program for monitoring and controlling ultrasonic anemometers for aerodynamic measurements in animal buildings  

Science Conference Proceedings (OSTI)

Ultrasonic anemometers (USAs) are widely implemented in animal housing to measure the air velocity in different measuring points throughout the whole barn, which ultimately leads to determine the velocity fields and the air flow patterns drawing a clear ... Keywords: Aerodynamics, Air profile, Airflow, Computer program, Precision livestock farming, Ultrasonic anemometer

M. Samer; C. Loebsin; K. von Bobrutzki; M. Fiedler; C. Ammon; W. Berg; P. Sanftleben; R. Brunsch

2011-10-01T23:59:59.000Z

256

A New Drag Relation for Aerodynamically Rough Flow over the Ocean  

Science Conference Proceedings (OSTI)

From almost 7000 near-surface eddy-covariance flux measurements over the sea, the authors deduce a new air–sea drag relation for aerodynamically rough flow:Here u* is the measured friction velocity, and UN10 is the neutral-stability wind speed at ...

Edgar L Andreas; Larry Mahrt; Dean Vickers

2012-08-01T23:59:59.000Z

257

Aerodynamic and Performance Measurements on a SWT-2.3-101 Wind Turbine  

DOE Green Energy (OSTI)

This paper provides an overview of a detailed wind turbine field experiment being conducted at NREL under U.S. Department of Energy sponsorship. The purpose of the experiment is to obtain knowledge about the aerodynamics, performance, noise emission and structural characteristics of the Siemens SWT-2.3-101 wind turbine.

Medina, P.; Singh, M.; Johansen, J.; Jove, A.R.; Machefaux, E.; Fingersh, L. J.; Schreck, S.

2011-10-01T23:59:59.000Z

258

Estimating Monthly Averaged Air-Sea Transfers of Heat and Momentum Using the Bulk Aerodynamic Method  

Science Conference Proceedings (OSTI)

Air-sea transfers of sensible heat, latent heat and momentum are computed from 25 years of middle-latitude and subtropical ocean weather ship data in the North Atlantic and North Pacific using the bulk aerodynamic method. The results show that ...

Steven K. Esbensen; Richard W. Reynolds

1981-04-01T23:59:59.000Z

259

Fan Aerodynamic Performance Guarantees: Do Your Policies, Procedures and Penalties Provide Adequate Certainty?  

E-Print Network (OSTI)

With few exceptions, fan vendors do not provide a written guarantee regarding aerodynamic performance. Some fan vendors even go so far as to state in their terms and conditions of sale that fan performance is not guaranteed unless it is specifically reque

Kaufman, S. G.; Martin, V.; Falk, M. A.

2004-01-01T23:59:59.000Z

260

Particle dispersing system and method for testing semiconductor manufacturing equipment  

DOE Patents (OSTI)

The system and method prepare a gas stream comprising particles at a known concentration using a particle disperser for moving particles from a reservoir of particles into a stream of flowing carrier gas. The electrostatic charges on the particles entrained in the carrier gas are then neutralized or otherwise altered, and the resulting particle-laden gas stream is then diluted to provide an acceptable particle concentration. The diluted gas stream is then split into a calibration stream and the desired output stream. The particles in the calibration stream are detected to provide an indication of the actual size distribution and concentration of particles in the output stream that is supplied to a process chamber being analyzed. Particles flowing out of the process chamber within a vacuum pumping system are detected, and the output particle size distribution and concentration are compared with the particle size distribution and concentration of the calibration stream in order to determine the particle transport characteristics of a process chamber, or to determine the number of particles lodged in the process chamber as a function of manufacturing process parameters such as pressure, flowrate, temperature, process chamber geometry, particle size, particle charge, and gas composition.

Chandrachood, Madhavi (Sunnyvale, CA); Ghanayem, Steve G. (Sunnyvale, CA); Cantwell, Nancy (Milpitas, CA); Rader, Daniel J. (Albuquerque, NM); Geller, Anthony S. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

PARTICLE ACCELERATOR  

DOE Patents (OSTI)

ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.

Teng, L.C.

1960-01-19T23:59:59.000Z

262

Structural effects of unsteady aerodynamic forces on horizontal-axis wind turbines  

DOE Green Energy (OSTI)

Due to its renewable nature and abundant resources, wind energy has the potential to fulfill a large portion of this nation`s energy needs. The simplest means of utilizing wind energy is through the use of downwind, horizontal-axis wind turbines (HAWT) with fixed-pitch rotors. This configuration regulates the peak power by allowing the rotor blade to aerodynamically stall. The stall point, the point of maximum coefficient of lift, is currently predicted using data obtained from wind tunnel tests. Unfortunately, these tests do not accurately simulate conditions encountered in the field. Flow around the tower and nacelle coupled with inflow turbulence and rotation of the turbine blades create unpredicted aerodynamic forces. Dynamic stall is hypothesized to occur. Such aerodynamic loads are transmitted into the rotor and tower causing structural resonance that drastically reduces the design lifetime of the wind turbine. The current method of alleviating this problem is to structurally reinforce the tower and blades. However, this adds unneeded mass and, therefore, cost to the turbines. A better understanding of the aerodynamic forces and the manner in which they affect the structure would allow for the design of more cost effective and durable wind turbines. Data compiled by the National Renewable Energy Laboratory (NREL) for a downwind HAWT with constant chord, untwisted, fixed-pitch rotors is analyzed. From these data, the actual aerodynamic characteristics of the rotor are being portrayed and the potential effects upon the structure can for the first time be fully analyzed. Based upon their understanding, solutions to the problem of structural resonance are emerging.

Miller, M.S.; Shipley, D.E. [Univ. of Colorado, Boulder, CO (United States). BioServe Space Technologies

1994-08-01T23:59:59.000Z

263

Aerodynamic Design Criteria for Class 8 Heavy Vehicles Trailer Base Devices to Attain Optimum Performance  

SciTech Connect

Lawrence Livermore National Laboratory (LLNL) as part of its Department of Energy (DOE), Energy Efficiency and Renewable Energy (EERE), and Vehicle Technologies Program (VTP) effort has investigated class 8 tractor-trailer aerodynamics for many years. This effort has identified many drag producing flow structures around the heavy vehicles and also has designed and tested many new active and passive drag reduction techniques and concepts for significant on the road fuel economy improvements. As part of this effort a database of experimental, computational, and conceptual design for aerodynamic drag reduction devices has been established. The objective of this report is to provide design guidance for trailer base devices to improve their aerodynamic performance. These devices are commonly referred to as boattails, base flaps, tail devices, and etc. The information provided here is based on past research and our most recent full-scale experimental investigations in collaboration with Navistar Inc. Additional supporting data from LLNL/Navistar wind tunnel, track test, and on the road test will be published soon. The trailer base devices can be identified by 4 flat panels that are attached to the rear edges of the trailer base to form a closed cavity. These devices have been engineered in many different forms such as, inflatable and non-inflatable, 3 and 4-sided, closed and open cavity, and etc. The following is an in-depth discussion with some recommendations, based on existing data and current research activities, of changes that could be made to these devices to improve their aerodynamic performance. There are 6 primary factors that could influence the aerodynamic performance of trailer base devices: (1) Deflection angle; (2) Boattail length; (3) Sealing of edges and corners; (4) 3 versus 4-sided, Position of the 4th plate; (5) Boattail vertical extension, Skirt - boattail transition; and (6) Closed versus open cavity.

Salari, K; Ortega, J

2010-12-13T23:59:59.000Z

264

RESONATOR PARTICLE SEPARATOR  

DOE Patents (OSTI)

A wave-guide resonator structure is designed for use in separating particles of equal momentum but differing in mass, having energies exceeding one billion eiectron volts. The particles referred to are those of sub-atomic size and are generally produced as a result of the bombardment of a target by a beam such as protons produced in a high energy accelerator. In the resonator a travelling electric wave is produced which travels at the same rate of speed as the unwanted particle which is thus deflected continuously over the length of the resonator. The wanted particle is slightly out of phase with the travelling wave so that over the whole length of the resonator it has a net deflection of substantially zero. The travelling wave is established in a wave guide of rectangular cross section in which stubs are provided to store magnetic wave energy leaving the electric wave energy in the main structure to obtain the desired travelling wave and deflection. The stubs are of such shape and spacing to establish a critical mathemitical relationship. (AEC)

Blewett, J.P.; Kiesling, J.D.

1963-06-11T23:59:59.000Z

265

Determining size-specific emission factors for environmental tobacco smoke  

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

Determining size-specific emission factors for environmental tobacco smoke Determining size-specific emission factors for environmental tobacco smoke particles Title Determining size-specific emission factors for environmental tobacco smoke particles Publication Type Journal Article Year of Publication 2003 Authors Klepeis, Neil E., Michael G. Apte, Lara A. Gundel, Richard G. Sextro, and William W. Nazaroff Journal Aerosol Science & Technology Volume 37 Start Page Chapter Pagination 780-790 Date Published October 2003 Abstract Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides -- in addition to estimates of the emissions size distribution and integrated emission factors -- estimates of deposition rate, an enhanced understanding of particle dynamics, and information about model performance. We applied the method to size-specific environmental tobacco smoke (ETS) particle concentrations measured every minute with an 8-channel optical particle counter (PMS-LASAIR; 0.1-2+ micrometer diameters) and every 10 or 30 min with a 34-channel differential mobility particle sizer (TSI-DMPS; 0.01-1+ micrometer diameters) after a single cigarette or cigar was machine-smoked inside a low air-exchange rate 20m^3 chamber. The aerosol dynamics model provided good fits to observed concentrations when using optimized values of mass emission rate and deposition rate for each particle size range as input. Small discrepancies observed in the first 1-2 hours after smoking are likely due to the effect of particle evaporation, a process neglected by the model. Size-specific ETS particle emission factors were fit with log-normal distributions, yielding an average mass median diameter of 0.2 micrometers and an average geometric standard deviation of 2.3 with no systematic differences between cigars and cigarettes. The equivalent total particle emission rate, obtained by integrating each size distribution, was 0.2-0.7 mg/min for cigars and 0.7-0.9 mg/min for cigarettes

266

Aerodynamic effects on fuel spray characteristics: Air-assist atomizer  

SciTech Connect

Results are presented on the internal structure of a kerosene fuel spray, generated with an air-assist type nozzle. Effects of atomization air flow rate and combustion air swirl on droplet transport processes have been investigated. Spatially-resolved measurements have been obtained on mean droplet size, number density and velocity, at different combustion air swirl and atomization air flow rates. An ensemble light scattering technique, based on measurement of the polarization ratio, and laser velocimetry have been used for these measurements. The results indicate that as atomization air flow rate increases, the spray becomes confined to a narrower spray angle; in addition, mean droplet size decreases and number density increases significantly along the spray centerline. Larger droplets are found generally on the spray boundary, and smaller ones near the spray centerline. In all cases, there is a gradual increase in mean droplet size along the spray centerline with axial distance. Under burning conditions the flame plume becomes short and intense, with fewer droplets penetrating through the flame envelope. Combustion air swirl and atomization air have a significant effect on the transport of droplets and on combustion characteristics of spray flames. 20 refs., 9 figs.

Presser, C.; Semerjian, H.G.; Gupta, A.K.

1988-01-01T23:59:59.000Z

267

Small Particles in Cirrus  

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

Particles in Cirrus Particles in Cirrus Because the reflective properties of ice crystals in cirrus clouds can greatly influence the amount of solar energy that reaches the Earth, scientists use information about the shape and size of ice crystals as input to climate models. These data are obtained by satellite instruments, ground-based sensors, and research aircraft equipped with probes. However, notable discrepancies among these measurements have led to considerable uncertainty in how to represent these properties in climate models. From December 2009 through April 2010, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will sponsor the use of an instrumented aircraft to obtain the most comprehensive set of measurements of ice crystals in cirrus clouds yet obtained. In conjunction with

268

NREL Studies Wind Farm Aerodynamics to Improve Siting (Fact Sheet), The Spectrum of Clean Energy Innovation, NREL (National Renewable Energy Laboratory)  

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

Studies Wind Farm Studies Wind Farm Aerodynamics to Improve Siting NREL researchers have used high-tech instruments and high- performance computing to understand atmospheric turbulence and turbine wake behavior in order to improve wind turbine design and siting within wind farms. The knowledge gained from this research could lead to improved turbine design standards, increased productivity in large wind farms, and a lower cost of energy from wind power. This is key, because as turbines grow in size-approximately doubling in height over the past five years-they present more complex challenges to wind turbine designers and operators. To gain new insights into turbine wind wakes, NREL and the Renewable and Sustainable Energy Institute (RASEI) joined together with the National Oceanic and Atmospheric Administration (NOAA), the

269

Microfluidic approaches to the synthesis of complex polymeric particles  

E-Print Network (OSTI)

The synthesis of micron-sized polymeric particles with precise control over shape, monodispersity and chemistry is a technologically important objective. Varied applications including medical diagnostics. designer fabrics ...

Dendukuri, Dhananjay, 1978-

2007-01-01T23:59:59.000Z

270

Nanometer Particles: Modern Methods of Research  

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

Nanometer Particles: Modern Methods of Research Nanometer Particles: Modern Methods of Research Speaker(s): Rashid Mavliev Date: August 10, 1999 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Richard Sextro "Nanometer particles" (with diameter below 50 - 100 nm) have attracted attention during recent years because of their increasing role in industries such as powder technology and semiconductors. They also play a critical role in atmospheric processes. At this size range the properties of particles are different from those of bulk materials and single molecules. This promises new technological innovations and potential scientific discoveries. At the same time it makes the detection and characterization of such particles imperative. Optical methods, which allow for simultaneous measurement of size and concentration of particles

271

Cat heart Size  

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

heart Size Name: Iris Status: student Grade: K-3 Location: OR Country: USA Date: NA Question: Can you tell me the size of a cats heart? Replies: Iris A cat's heart is about the...

272

Cat heart Size  

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

Cat heart Size Name: Rebecca Status: student Grade: 6-8 Location: FL Country: USA Date: Spring 2011 Question: What is the average size of a cat's heart? Replies: Hi Rebecca, That...

273

Hopper Job Size Charts  

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

charts shows the fraction of hours used on Hopper in each of 5 job-core-size bins. 2012 Usage by Job Size Chart 2011 . This chart shows the fraction of hours used on Hopper by jobs...

274

Particle swarm optimization with opposite particles  

Science Conference Proceedings (OSTI)

The particle swarm optimization algorithm is a kind of intelligent optimization algorithm. This algorithm is prone to be fettered by the local optimization solution when the particle's velocity is small. This paper presents a novel particle swarm ...

Rujing Wang; Xiaoming Zhang

2005-11-01T23:59:59.000Z

275

Particle Size Analysis of Multimodal Gamma-Prime (?') Distributions ...  

Science Conference Proceedings (OSTI)

Evolution of Internal Strain with Temperature in Depleted Uranium in the Presence of Hydrides · EXAFS Study of Local Atomic Environment in Annealed and ...

276

Certification of SRM 114q: Part II (Particle size distribution)  

Science Conference Proceedings (OSTI)

... Physical and Chemical Properties2 • Analytical Chemistry ... and Conformance Testing • Statistical Engineering ... and the requirements for sample ...

2011-08-04T23:59:59.000Z

277

Particle Size Effect in Nanomaterials Using Phase Field Simulations  

Science Conference Proceedings (OSTI)

This reduction can also be predicted by Herring's scaling law. However, it is observed that the sintering of nanomaterials deviates from Herring scaling law.

278

Certification of SRM 114q: Part II (Particle size distribution)  

Science Conference Proceedings (OSTI)

... LA: Ronald J. Rajki California Portland Cement ... Mitsubishi Cement Corp., Lucerne Valley, CA: Tom ... of diffracted light around the central beam can ...

2006-12-07T23:59:59.000Z

279

Particle Size on the Deformation Mechanism in an Advanced ...  

Science Conference Proceedings (OSTI)

field emission gun scanning electron microscope (FEGSEM). Deformation ... with post mortem electron microscopy studies that the load transfer observed can be ...

280

Effect of Particle Size on the Microstructure of Rapidly Solidified ...  

Science Conference Proceedings (OSTI)

A Study on the Stress Test of Truck Frames for Freight Trains · A Study on the ... Defect Energetics and Fission Product Transport in ZrC · Deformation Field and ...

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Effect of Magnesium Doping on the Structure, Particle Size and ...  

Science Conference Proceedings (OSTI)

Synthesis and Characterization of Plasma Polymerized Thin Films Deposited from Benzene and Hexamethyldisiloxane Using (PECVD) Method · Synthesis and ...

282

Whole wheat flour milling: effects of variety and particle size.  

E-Print Network (OSTI)

??Nutrition from whole grains has become an integral part of a healthy diet. Consumers are focused on adding fiber and whole grains to be healthy… (more)

Turner, Justin B.

2012-01-01T23:59:59.000Z

283

Substrate Temperature Effects on Adhesion and Particle Size of ...  

Science Conference Proceedings (OSTI)

Author(s), Alan Boardman, Ashutosh Tiwari. On-Site Speaker (Planned), Alan Boardman. Abstract Scope, Gold thin film layers were prepared by magnetron ...

284

Comprehensive Effect of Coke Breeze and Limestone Particle Size ...  

Science Conference Proceedings (OSTI)

Chemical Enrichment of Precious Metals in Iron Sulfides Using Microwave Energy · Chloridizing ... Co-Gasification Behavior of Metallurgical Coke with High and Low Reactivity .... Thermal Plasma Torches for Metallurgical Applications.

285

The Particle Adventure | Glossary  

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

Charge A quantum number carried by a particle. Determines whether the particle can participate in an interaction process. A particle with electric charge has electrical...

286

The Particle Adventure | Glossary  

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

Stable Does not decay. A particle is stable if there exist no processes in which a particle disappears and in its place different particles appear...

287

The Particle Adventure | Glossary  

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

Event What occurs when two particles collide or a single particle decays. Particle theories predict the probabilities of various possible events occurring when many similar...

288

A comparative study of the aerodynamics of several wind turbines using flow visualization  

Science Conference Proceedings (OSTI)

This paper reports flow visualization techniques used to study the flows over the Enertech 21-5, Carter 25, and Enertech 44-50. Despite centrifugal effects superimposed on the aerodynamics, tufting (gross aerodynamic behavior) and oil flow (average boundary layer behavior), tests reveal the nature and many of the details of the flows involved. Results were compared to expected flow patterns based on angles of attack calculated from the PROPPC code. Chord Reynolds numbers ranged between 75,000 (Enertech 21-5) to 1,340,000 (Enertech 44-50). The typical low Reynolds number flow characteristics of these airfoils, including laminar separation bubbles, turbulent reattachment, and complete separation were observed. full or partial reattachment due to tower shadow was observed on each machine. Spanwise flow was observed near the leading edge of the Enertech 21-5. Cyclic radial flow from tower dam effect was also noted.

Eggleston, D.M. (Control Engineering, Univ. of Texas of the Permian Basin, Odessa, TX (US)); Starcher, K. (Alternative Energy Inst., West Texas State Univ., Canyon, TX (US))

1990-11-01T23:59:59.000Z

289

Effects of flow curvature on the aerodynamics of Darrieus wind turbines  

DOE Green Energy (OSTI)

A theoretical and experimental investigation was conducted which clearly showed the effects of flow curvature to be significant determinants of Darrieus turbine blade aerodynamics; qualitatively, these results apply equally to straight or curved bladed machines. Unusually large boundary layer radial pressure gradients and virtually altered camber and incidence are the phenomena of primary importance. Conformal mapping techniques were developed which transform the geometric turbine airfoils in curved flow to their virtual equivalents in rectilinear flow, thereby permitting the more accurate selection of airfoil aerodynamic coefficients from published sectional data. It is demonstrated that once the flow idiosyncracies are fully understood, they may be used to advantage to improve the wind energy extraction efficiency of these machines.

Migliore, P. G.; Wolfe, W. P.

1980-07-01T23:59:59.000Z

290

July 2004 Working Group Meeting on Heavy Vehicle Aerodynamic Drag: Presentation, Summary of Comments, and Conclusions  

SciTech Connect

A Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held in Portland, Oregon on July 1, 2004. The purpose of the meeting was to provide a summary of achievements, discuss pressing issues, present a general overview of future plans, and to provide a forum for dialogue with the Department of Energy (DOE) and industry representatives. The meeting was held in Portland, because the DOE Aero Team participated in an exclusive session on Heavy Truck Vehicle Aerodynamic Drag at the 34th AIAA Fluid Dynamics Conference and Exhibit in Portland on the morning of July 1st, just preceding our Working Group meeting. Even though the paper session was on the last day of the Conference, the Team presented to a full room of interested attendees.

McCallen, R; Salari, K; Ortega, J; Castellucci, P; Eastwood, C; DeChant, L; Hassan, B; Browand, F; Arcas, D; Ross, J; Heineck, J; Storms, B; Walker, S; Leonard, A; Roy, C; Whitfield, D; Pointer, D; Sofu, T; Englar, R; Funk, R

2004-08-17T23:59:59.000Z

291

A Multi-Year Program Plan for the Aerodynamic Design of Heavy Vehicles  

DOE Green Energy (OSTI)

The project tasks and deliverables are as follows: Computations and Experiments--(1) Simulation and analysis of a range of generic shapes, simplified to more complex, representative of tractor and integrated tractor-trailer flow characteristics using computational tools, (2) The establishment of an experimental data base for tractor-trailer models for code/computational method development and validation. The first shapes to be considered will be directed towards the investigation of tractor-trailer gaps and mismatch of tractor-trailer heights. (3) The evaluation and documentation of effective computational approaches for application to heavy vehicle aerodynamics based on the benchmark results with existing and advanced computational tools compared to experimental data, and (4) Computational tools and experimental methods for use by industry, National Laboratories, and universities for the aerodynamic modeling of heavy truck vehicles. Evaluation of current and new technologies--(1) The evaluation and documentation of current and new technologies for drag reduction based on published literature and continued communication with the heavy vehicle industry (e.g., identification and prioritization of tractor-trailer drag-sources, blowing and/or suction devices, body shaping, new experimental methods or facilities), and the identification and analysis of tractor and integrated tractor-trailer aerodynamic problem areas and possible solution strategies. (2) Continued industrial site visits. It should be noted that ''CFD tools'' are not only the actual computer codes, but descriptions of appropriate numerical solution methods. Part of the project effort will be to determine the restrictions or avenues for technology transfer.

None

2001-09-01T23:59:59.000Z

292

Influence of grain size, morphology and aggregation on galena dissolution.  

E-Print Network (OSTI)

??The acidic, non-oxidative dissolution of galena nanocrystals has been studied using both microscopic and wet-chemical methods. The effects of particle size, shape, aggregation state, and… (more)

Liu, Juan

2009-01-01T23:59:59.000Z

293

Terminal Velocities of Droplets and Crystals: Power Laws with Continuous Parameters over the Size Spectrum  

Science Conference Proceedings (OSTI)

This paper presents a unified treatment of cloud particle fall velocities for both liquid and crystalline cloud particles over the entire size range observed in the atmosphere. The fall velocity representation is formulated in terms of the Best (...

Vitaly I. Khvorostyanov; Judith A. Curry

2002-06-01T23:59:59.000Z

294

Vapor scavenging by atmospheric aerosol particles  

Science Conference Proceedings (OSTI)

Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

Andrews, E.

1996-05-01T23:59:59.000Z

295

Size separation in vibrated granular matter  

E-Print Network (OSTI)

We review recent developments in size separation in vibrated granular materials. Motivated by a need in industry to efficiently handle granular materials and a desire to make fundamental advances in non-equilibrium physics, experimental and theoretical investigations have shown size separation to be a complex phenomena. Large particles in a vibrated granular system invariably rise to the top. However, they may also sink to the bottom, or show other patterns depending on subtle variations in physical conditions. While size ratio is a dominant factor, particle specific properties such as density, inelasticity and friction can play an important role. The nature of the energy input, boundary conditions and interstitial air have been also shown to be significant factors in determining spatial distributions. The presence of convection can enhance mixing or lead to size separation. Experimental techniques including direct visualization and magnetic resonance imaging are being used to investigate these properties. Molecular dynamics and Monte Carlo simulation techniques have been developed to probe size separation. Analytical methods such as kinetic theory are being used to study the interplay between particle size and density in the vibro-fluidized regime, and geometric models have been proposed to describe size separation for deep beds. Besides discussing these studies, we will also review the impact of inelastic collision and friction on the density and velocity distributions to gain a deeper appreciation of the non-equilibrium nature of the system. While a substantial number of studies have been accomplished, considerable work is still required to achieve a firm description of the phenomena.

A. Kudrolli

2004-02-06T23:59:59.000Z

296

Sub-micron particle sampler apparatus  

DOE Patents (OSTI)

Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar.RTM. and the assembly is then crushed into a pellet. This effectively traps the sub-micron sized particles for later analysis.

Gay, Don D. (Aiken, SC); McMillan, William G. (Ulmers, SC)

1987-01-01T23:59:59.000Z

297

Method for sampling sub-micron particles  

DOE Patents (OSTI)

Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar.RTM. and the assembly is then crushed into a pellet. This effectively traps the sub-micron sized particles for later analysis.

Gay, Don D. (Aiken, SC); McMillan, William G. (Ulmers, SC)

1985-01-01T23:59:59.000Z

298

AEROSOL PARTICLE COLLECTOR DESIGN STUDY  

Science Conference Proceedings (OSTI)

A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

Lee, S; Richard Dimenna, R

2007-09-27T23:59:59.000Z

299

Superoleophilic particles and coatings and methods of making the same  

DOE Patents (OSTI)

Superoleophilic particles and surfaces and methods of making the same are described. The superoleophilic particles can include porous particles having a hydrophobic coating layer deposited thereon. The coated porous particles are characterized by particle sizes ranging from at least 100 nm to about 10 .mu.m and a plurality of nanopores. Some of the nanopores provide flow through porosity. The superoleophilic particles also include oil pinned within the nanopores of the porous particles The plurality of porous particles can include (i) particles including a plurality of spaced apart nanostructured features comprising a contiguous, protrusive material, (ii) diatomaceous earth particles, or (iii) both. The surfaces can include the superoleophilic particles coupled to the surface.

Simpson, John T; D& #x27; Urso, Brian

2013-07-30T23:59:59.000Z

300

Aerodynamic characteristics of seven symmetrical airfoil sections through 180-degree angle of attack for use in aerodynamic analysis of vertical axis wind turbines  

Science Conference Proceedings (OSTI)

When work began on the Darrieus vertical axis wind turbine (VAWT) program at Sandia National Laboratories, it was recognized that there was a paucity of symmetrical airfoil data needed to describe the aerodynamics of turbine blades. Curved-bladed Darrieus turbines operate at local Reynolds numbers (Re) and angles of attack (..cap alpha..) seldom encountered in aeronautical applications. This report describes (1) a wind tunnel test series conducted at moderate values of Re in which 0 less than or equal to ..cap alpha.. less than or equal to 180/sup 0/ force and moment data were obtained for four symmetrical blade-candidate airfoil sections (NACA-0009, -0012, -0012H, and -0015), and (2) how an airfoil property synthesizer code can be used to extend the measured properties to arbitrary values of Re (10/sup 4/ less than or equal to Re less than or equal to 10/sup 7/) and to certain other section profiles (NACA-0018, -0021, -0025).

Sheldahl, R E; Klimas, P C

1981-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Doppler Cloud Radar Derived Drop Size Distributions in Liquid Water Stratus Clouds  

Science Conference Proceedings (OSTI)

A cloud particle size retrieval algorithm that uses radar reflectivity factor and Doppler velocity obtained by a 35-GHz Doppler radar and liquid water path estimated from microwave radiometer radiance measurements is developed to infer the size ...

Seiji Kato; Gerald G. Mace; Eugene E. Clothiaux; James C. Liljegren; Richard T. Austin

2001-10-01T23:59:59.000Z

302

Comparison of Raindrop Size Distribution Measurements by Collocated Disdrometers  

Science Conference Proceedings (OSTI)

An impact-type Joss–Waldvogel disdrometer (JWD), a two-dimensional video disdrometer (2DVD), and a laser optical OTT Particle Size and Velocity (PARSIVEL) disdrometer (PD) were used to measure the raindrop size distribution (DSD) over a 6-month ...

Ali Tokay; Walter A. Petersen; Patrick Gatlin; Matthew Wingo

2013-08-01T23:59:59.000Z

303

Are Black Holes Elementary Particles?  

E-Print Network (OSTI)

Quantum black holes are the smallest and heaviest conceivable elementary particles. They have a microscopic size but a macroscopic mass. Several fundamental types have been constructed with some remarkable properties. Quantum black holes in the neighborhood of the Galaxy could resolve the paradox of ultra-high energy cosmic rays detected in Earth’s atmosphere. They may also play a role as dark matter in cosmology. 1 1

Yuan K. Ha

2009-01-01T23:59:59.000Z

304

Development of Pneumatic Aerodynamic Devices to Improve the Performance, Economics, and Safety of Heavy Vehicles  

SciTech Connect

Under contract to the DOE Office of Heavy Vehicle Technologies, the Georgia Tech Research Institute (GTRI) is developing and evaluating pneumatic (blown) aerodynamic devices to improve the performance, economics, stability and safety of operation of Heavy Vehicles. The objective of this program is to apply the pneumatic aerodynamic aircraft technology previously developed and flight-tested by GTRI personnel to the design of an efficient blown tractor-trailer configuration. Recent experimental results obtained by GTRI using blowing have shown drag reductions of 35% on a streamlined automobile wind-tunnel model. Also measured were lift or down-load increases of 100-150% and the ability to control aerodynamic moments about all 3 axes without any moving control surfaces. Similar drag reductions yielded by blowing on bluff afterbody trailers in current US trucking fleet operations are anticipated to reduce yearly fuel consumption by more than 1.2 billion gallons, while even further reduction is possible using pneumatic lift to reduce tire rolling resistance. Conversely, increased drag and down force generated instantaneously by blowing can greatly increase braking characteristics and control in wet/icy weather due to effective ''weight'' increases on the tires. Safety is also enhanced by controlling side loads and moments caused on these Heavy Vehicles by winds, gusts and other vehicles passing. This may also help to eliminate the jack-knifing problem if caused by extreme wind side loads on the trailer. Lastly, reduction of the turbulent wake behind the trailer can reduce splash and spray patterns and rough air being experienced by following vehicles. To be presented by GTRI in this paper will be results developed during the early portion of this effort, including a preliminary systems study, CFD prediction of the blown flowfields, and design of the baseline conventional tractor-trailer model and the pneumatic wind-tunnel model.

Robert J. Englar

2000-06-19T23:59:59.000Z

305

Numerical simulation of VAWT stochastic aerodynamic loads produced by atmospheric turbauence: VAWT-SAL code  

DOE Green Energy (OSTI)

Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). A principal source of blade fatigue is thought to be the stochastic (i.e., random) aerodynamic loads created by atmospheric turbulence. This report describes the theoretical background of the VAWT Stochastic Aerodynamic Loads (VAWT-SAL) computer code, whose purpose is to numerically simulate these random loads, given the rotor geometry, operating conditions, and assumed turbulence properties. A Double-Multiple-Stream Tube (DMST) analysis is employed to model the rotor's aerodynamic response. The analysis includes the effects of Reynolds number variations, different airfoil sections and chord lengths along the blade span, and an empirical model for dynamic stall effects. The mean ambient wind is assumed to have a shear profile which is described by either a power law or a logarithmic variation with height above ground. Superimposed on this is a full 3-D field of turbulence: i.e., in addition to random fluctuations in time, the turbulence is allowed to vary randomly in planes perpendicular to the mean wind. The influence of flow retardation on the convection of turbulence through the turbine is also modeled. Calculations are presented for the VAWT 34-m Test Bed currently in operation at Bushland, Texas. Predicted time histories of the loads, as well as their Fourier spectra, are presented and discussed. Particular emphasis is placed on the differences between so-called steady-state'' (mean wind only) predictions, and those produced with turbulence present. Somewhat surprisingly, turbulence is found to be capable of either increasing or decreasing the average output power, depending on the turbine's tip-speed ratio. A heuristic explanation for such behavior is postulated, and a simple formula is derived for predicting the magnitude of this effect without the need for a full stochastic simulation. 41 refs., 32 figs., 1 tab.

Homicz, G.F.

1991-09-01T23:59:59.000Z

306

Fine Particle Emissions from Combustion Systems  

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

Fine Particle Emissions from Combustion Systems Fine Particle Emissions from Combustion Systems Speaker(s): Allen Robinson Date: November 11, 2005 - 12:00pm Location: 90-3122 Combustion systems such as motor vehicles and power plants are major sources of fine particulate matter. This talk describes some of the changes in fine particle emissions that occur as exhaust from combustion systems mix with background air. This mixing cools and dilutes the exhaust which influences gas-particle partitioning of semi-volatile species, the aerosol size distribution, and the fine particle mass. Dilution sampling is used to characterize fine particle emissions from combustion systems because it simulates the rapid cooling and dilution that occur as exhaust mixes with the atmosphere. Results from dilution sampler

307

Mapping Particle Charges in Battery Electrodes  

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

Mapping Particle Charges in Battery Electrodes Print Mapping Particle Charges in Battery Electrodes Print The deceivingly simple appearance of batteries masks their chemical complexity. A typical lithium-ion battery in a cell phone consists of trillions of particles. When a lithium-ion battery is charged or discharged lithium ions move from one electrode to another, filling and unfilling individual, variably-sized battery particles. The rates of these processes determine how much power a battery can deliver. Despite the technological innovations and widespread use of batteries, the mechanism behind charging and discharging particles remains largely a mystery, partly because it is difficult to visualize the motion of lithium ions for a significant number of battery particles at nanoscale resolution.

308

Mapping Particle Charges in Battery Electrodes  

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

Mapping Particle Charges in Battery Electrodes Print Mapping Particle Charges in Battery Electrodes Print The deceivingly simple appearance of batteries masks their chemical complexity. A typical lithium-ion battery in a cell phone consists of trillions of particles. When a lithium-ion battery is charged or discharged lithium ions move from one electrode to another, filling and unfilling individual, variably-sized battery particles. The rates of these processes determine how much power a battery can deliver. Despite the technological innovations and widespread use of batteries, the mechanism behind charging and discharging particles remains largely a mystery, partly because it is difficult to visualize the motion of lithium ions for a significant number of battery particles at nanoscale resolution.

309

A Numerical Determination of the Evolution of Cloud Drop Spectra due to Condensation on Natural Aerosol Particles  

Science Conference Proceedings (OSTI)

The time variation in size of aerosol particles growing by condensation is studied numerically by means of an air parcel model which allows entrainment of air and aerosol particles. Particles of four types of aerosols typically occurring in ...

In Young Lee; G. Hänel; H. R. Pruppacher

1980-08-01T23:59:59.000Z

310

Proton Size Anomaly  

SciTech Connect

A measurement of the Lamb shift in muonic hydrogen yields a charge radius of the proton that is smaller than the CODATA value by about 5 standard deviations. We explore the possibility that new scalar, pseudoscalar, vector, and tensor flavor-conserving nonuniversal interactions may be responsible for the discrepancy. We consider exotic particles that, among leptons, couple preferentially to muons and mediate an attractive nucleon-muon interaction. We find that the many constraints from low energy data disfavor new spin-0, spin-1, and spin-2 particles as an explanation.

Barger, Vernon [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Chiang, Cheng-Wei [Department of Physics and Center for Mathematics and Theoretical Physics, National Central University, Chungli, Taiwan 32001 (China); Institute of Physics, Academia Sinica, Nankang, Taipei 11925 (China); Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Keung, Wai-Yee [Department of Physics, University of Illinois, Chicago, Illinois 60607 (United States); Marfatia, Danny [Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045 (United States); Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2011-04-15T23:59:59.000Z

311

Land animal sizes  

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

Land animal sizes Name: tamar c Status: NA Age: NA Location: NA Country: NA Date: Around 1993 Question: Why are today's land mammals so much smaller than prehistoric mammals?...

312

Multimodal Raindrop Size Distributions  

Science Conference Proceedings (OSTI)

The raindrop size distributions (DSDs) observed over a short span usually have an erratic shape, with several relative maxima. This multimodal structure is studied from disdrometer data acquired in tropical and midlatitude areas. It is shown that ...

Henri Sauvageot; Manlandon Koffi

2000-08-01T23:59:59.000Z

313

Raindrop Size Distribution  

Science Conference Proceedings (OSTI)

This paper reviews some of the published results relating to raindrop-size distributions and couples this with some of the authors' results in order to show that the mathematical description of the distribution can be divided into three ...

M. C. Hodson

1986-07-01T23:59:59.000Z

314

ARM - Measurement - Hydrometeor size  

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

size size ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor size The size of a hydrometeor, measured directly or derived from other measurements . Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments DISDROMETER : Impact Disdrometer LDIS : Laser Disdrometer External Instruments CPOL : C-Band Polarimetric Radar Field Campaign Instruments EC-CONVAIR580-BULK : Environment Canada Convair 580 Bulk Parameters

315

Aerodynamics overview of the ground transportation systems (GTS) project for heavy vehicle drag reduction  

DOE Green Energy (OSTI)

The focus of the research was to investigate the fundamental aerodynamics of the base flow of a tractor trailer that would prove useful in fluid flow management. Initially, industry design needs and constraints were defined. This was followed by an evaluation of state-of-the-art Navier-Stokes based computational fluid dynamics tools. Analytical methods were then used in combination with computational tools in a design process. Several geometries were tested at 1:8 scale in a low speed wind tunnel. In addition to the baseline geometry, base add-on devices of the class of ogival boattails and slants were analyzed.

Gutierrez, W.T.; Hassan, B.; Croll, R.H.; Rutledge, W.H.

1995-12-31T23:59:59.000Z

316

The Particle Adventure | Particle decays and annihiliations ...  

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

alphabet: (alpha), (beta), and (gamma). Alpha particles are helium nuclei (2 p, 2 n): Beta particles are speedy electrons: Gamma radiation is a high-energy photon: These three...

317

The Particle Adventure  

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

Is this particle really the Higgs... Is this particle really the Higgs Boson? Does it swim and quack like a duck? While decays of this kind had been observed for the new particle...

318

The Particle Adventure | Glossary  

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

Boson A particle that has integer intrinsic angular momentum (spin) measured in units of h-bar (spin 0, 1, 2, ...). All particles are either fermions or bosons. The particles...

319

The Particle Adventure | Glossary  

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

Rest Mass The rest mass (m) of a particle is the mass defined by the energy of the isolated (free) particle at rest, divided by the speed of light squared. When particle physicists...

320

The Particle Adventure | Glossary  

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

Decay A process in which a particle disappears and in its place different particles appear. The sum of the masses of the produced particles is always less than the mass of the...

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

In-Situ Monitoring of Particle Growth at PEMFC Cathode under Accelerated Cycling Conditions  

SciTech Connect

An in-situ method to measure changes in catalyst particle size at the cathode of a proton exchange membrane fuel cell is demonstrated. Synchrotron X-rays, 58 keV, were used to measure the pair distribution function on an operating fuel cell and observe the growth of catalyst particles under accelerated degradation conditions. The stability of Pt/C and PtCo/C with different initial particle sizes was monitored over 3000 potential cycles. The increase in particle size was fit to a linear trend as a function of cycles. The most stable electrocatalyst was found to be the alloyed PtCo with the larger initial particle size.

Redmond, Erin L.; Setzler, Brian P.; Juhas, Pavol; Billinge, Simon J.L.; Fuller, Thomas F. (GIT); (Columbia)

2012-10-25T23:59:59.000Z

322

In-Situ Monitoring of Particle Growth at PEMFC Cathode under Accelerated Cycling Conditions  

SciTech Connect

An in-situ method to measure changes in catalyst particle size at the cathode of a proton exchange membrane fuel cell is demonstrated. Synchrotron X-rays, 58 keV, were used to measure the pair distribution function on an operating fuel cell and observe the growth of catalyst particles under accelerated degradation conditions. The stability of Pt/C and PtCo/C with different initial particle sizes was monitored over 3000 potential cycles. The increase in particle size was fit to a linear trend as a function of cycles. The most stable electrocatalyst was found to be the alloyed PtCo with the larger initial particle size.

Billinge S. J.; Redmond, E.L.; Setzler, B.P.; Juhas, P.; Fullera, T.F.

2012-05-01T23:59:59.000Z

323

Engineered plant biomass feedstock particles  

DOE Patents (OSTI)

A novel class of flowable biomass feedstock particles with unusually large surface areas that can be manufactured in remarkably uniform sizes using low-energy comminution techniques. The feedstock particles are roughly parallelepiped in shape and characterized by a length dimension (L) aligned substantially with the grain direction and defining a substantially uniform distance along the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L. The particles exhibit a disrupted grain structure with prominent end and surface checks that greatly enhances their skeletal surface area as compared to their envelope surface area. The L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers. The W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers. The L.times.W dimensions define a pair of substantially parallel top surfaces characterized by some surface checking between longitudinally arrayed fibers. At least 80% of the particles pass through a 1/4 inch screen having a 6.3 mm nominal sieve opening but are retained by a No. 10 screen having a 2 mm nominal sieve opening. The feedstock particles are manufactured from a variety of plant biomass materials including wood, crop residues, plantation grasses, hemp, bagasse, and bamboo.

Dooley, James H. (Federal Way, WA); Lanning, David N. (Federal Way, WA); Broderick, Thomas F. (Lake Forest Park, WA)

2011-10-18T23:59:59.000Z

324

Sub-micron particle sampler apparatus and method for sampling sub-micron particles  

DOE Patents (OSTI)

Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however, the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar and the assembly is then crushed into a pellet. This effectively traps the sub-micron sized particles for later analysis. 6 figures.

Gay, D.D.; McMillan, W.G.

1984-04-12T23:59:59.000Z

325

Nuclear & Particle Physics Directorate  

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

Nuclear & Particle Physics Directorate Nuclear and Particle Physics (NPP) at BNL comprises the Collider-Accelerator Department (including the NASA Space Radiation Laboratory,...

326

Particle Physics Booklet 2008  

E-Print Network (OSTI)

212 25. Accelerator physics of colliders ? 26. High-energythe full Review. PARTICLE PHYSICS BOOKLET TABLE OF CONTENTSrev. ) Summary Tables of Particle Physics Gauge and Higgs

et al., C. Amsler

2008-01-01T23:59:59.000Z

327

Small Particles, Big Impact  

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

Small Particles, Big Impact Small Particles, Big Impact Small-scale effects of Aerosols Add up Over Time August 24, 2011 | Tags: Climate Research, Earth Sciences, Environmental...

328

Glossary Term - Beta Particle  

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

Decay Previous Term (Beta Decay) Glossary Main Index Next Term (Bohr Radius) Bohr Radius Beta Particle Beta particles are either electrons or positrons ejected from the nucleus....

329

Glossary Term - Alpha Particle  

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

Decay Previous Term (Alpha Decay) Glossary Main Index Next Term (Atomic Number) Atomic Number Alpha Particle alphaparticle.gif Produced during alpha decay, an alpha particle is a...

330

The Particle Adventure | Glossary  

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

Virtual Particle A particle that exists only for an extremely brief instant in an intermediary process. Then the Heisenberg Uncertainty Principle allows an apparent violation of...

331

The Particle Adventure | Glossary  

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

Annihilation A process in which a particle meets its corresponding antiparticle and both disappear. The energy appears in some other form, perhaps as a different particle and its...

332

The Particle Adventure | Glossary  

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

Chamber The outer layers of a particle detector capable of registering tracks of charged particles. Except for the chargeless neutrinos, only muons reach this layer from the...

333

The Particle Adventure | Glossary  

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

Hadron A particle made of strongly-interacting constituents (quarks andor gluons). These include the meson and baryons. Such particles participate in residual strong interactions...

334

Aerodynamically induced radial forces in a centrifugal gas compressor: Part 2 -- Computational investigation  

SciTech Connect

Radial loads and direction of a centrifugal gas compressor containing a high specific speed mixed flow impeller and a single tongue volute were determined both experimentally and computationally at both design and off-design conditions. The experimental methodology was developed in conjunction with a traditional ASME PTC-10 closed-loop test to determine radial load and direction. The experimental study is detailed in Part 1 of this paper (Moore and Flathers, 1998). The computational method employs a commercially available, fully three-dimensional viscous code to analyze the impeller and the volute interaction. An uncoupled scheme was initially used where the impeller and volute were analyzed as separate models using a common vaneless diffuser geometry. The two calculations were then repeated until the boundary conditions at a chosen location in the common vaneless diffuser were nearly the same. Subsequently, a coupled scheme was used where the entire stage geometry was analyzed in one calculation, thus eliminating the need for manual iteration of the two independent calculations. In addition to radial load and direction information, this computational procedure also provided aerodynamic stage performance. The effect of impeller front face and rear face cavities was also quantified. The paper will discuss computational procedures, including grid generation and boundary conditions, as well as comparisons of the various computational schemes to experiment. The results of this study will show the limitations and benefits of Computational Fluid Dynamics (CFD) for determination of radial load, direction, and aerodynamic stage performance.

Flathers, M.B.; Bache, G.E.

1999-10-01T23:59:59.000Z

335

Advanced Aerodynamic Devices to Improve the Performance, Economics, Handling, and Safety of Heavy Vehicles  

Science Conference Proceedings (OSTI)

Research is being conducted at the Georgia Tech Research Institute (GTRI) to develop advanced aerodynamic devices to improve the performance, economics, stability, handling and safety of operation of Heavy Vehicles by using previously-developed and flight-tested pneumatic (blown) aircraft technology. Recent wind-tunnel investigations of a generic Heavy Vehicle model with blowing slots on both the leading and trailing edges of the trailer have been conducted under contract to the DOE Office of Heavy Vehicle Technologies. These experimental results show overall aerodynamic drag reductions on the Pneumatic Heavy Vehicle of 50% using only 1 psig blowing pressure in the plenums, and over 80% drag reductions if additional blowing air were available. Additionally, an increase in drag force for braking was confirmed by blowing different slots. Lift coefficient was increased for rolling resistance reduction by blowing only the top slot, while downforce was produced for traction increase by blowing only the bottom. Also, side force and yawing moment were generated on either side of the vehicle, and directional stability was restored by blowing the appropriate side slot. These experimental results and the predicted full-scale payoffs are presented in this paper, as is a discussion of additional applications to conventional commercial autos, buses, motor homes, and Sport Utility Vehicles.

Robert J. Englar

2001-05-14T23:59:59.000Z

336

Size-dependent piezoelectricity  

E-Print Network (OSTI)

In this paper, a consistent theory is developed for size-dependent piezoelectricity in dielectric solids. This theory shows that electric polarization can be generated as the result of coupling to the mean curvature tensor, unlike previous flexoelectric theories that postulate such couplings with other forms of curvature and more general strain gradient terms ignoring the possible couple- stresses. The present formulation represents an extension of recent work that establishes a consistent size-dependent theory for solid mechanics. Here by including scale-dependent measures in the energy equation, the general expressions for force- and couple-stresses, as well as electric displacement, are obtained. Next, the constitutive relations, displacement formulations, the uniqueness theorem and the reciprocal theorem for the corresponding linear small deformation size-dependent piezoelectricity are developed. As with existing flexoelectric formulations, one finds that the piezoelectric effect can also exist in isotrop...

Hadjesfandiari, Ali R

2013-01-01T23:59:59.000Z

337

Physics Out Loud - Particle Resonance  

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

Particle Accelerator Previous Video (Particle Accelerator) Physics Out Loud Main Index Next Video (Photomultiplier Tube) Photomultiplier Tube Particle Resonance How is a particle...

338

Modeling Cirrus Clouds. Part I: Treatment of Bimodal Size Spectra and Case Study Analysis  

Science Conference Proceedings (OSTI)

A model has been developed that predicts the evolution of bimodal size spectra in cirrus clouds. This was done by predicting two size distributions: one for ice particles less than about 150 µm and another for larger particles. The sum of these ...

David L. Mitchell; Steven K. Chai; Yangang Liu; Andrew J. Heymsfield; Yayi Dong

1996-10-01T23:59:59.000Z

339

Pore size estimation  

Science Conference Proceedings (OSTI)

A novel method for characterization of any porous structure is presented. The principle of the method is simple scanning a plane surface of a cellular material and consequent digital image analysis of the scan. Eleven samples of bread baked from dough ... Keywords: foams, image analysis, modelling the structure, plane cut visualization, pore size distribution, voronoi tessellation

Tomas Matousek; Petr Ponizil; Filip Kremen; Iva Buresova; Petra Dvorakova

2011-07-01T23:59:59.000Z

340

A concentration rebound method for measuring particle penetration and  

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

A concentration rebound method for measuring particle penetration and A concentration rebound method for measuring particle penetration and deposition in the indoor environment Title A concentration rebound method for measuring particle penetration and deposition in the indoor environment Publication Type Journal Article LBNL Report Number LBNL-51631 Year of Publication 2003 Authors Thatcher, Tracy L., Melissa M. Lunden, Kenneth L. Revzan, Richard G. Sextro, and Nancy J. Brown Journal Aerosol Science & Technology Volume 37 Start Page Chapter Pagination 847-864 Abstract Continuous, size resolved particle measurements were performed in two houses in order to determine size- dependent particle penetration into and deposition in the indoor environment. The experiments consisted of three parts: measurement of the particle loss rate following artificial elevation of indoor particle concentrations,

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Impact of Hight Velocity Cold Spray Particles  

SciTech Connect

This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped that the results presented will allow better understanding of the bonding process during cold spray.

Dykhuizen, R.C.; Gilmore, D.L.; Jiang, X.; Neiser, R.A.; Sampath, S.; Smith, M.F.

1998-12-01T23:59:59.000Z

342

Scattering Functions of Yolk-Shell Particles  

SciTech Connect

The single-particle small-angle scattering properties of the yolk-shell particle, a new type of core-shell particle with a mobile core within the hosting shell, are systematically investigated. The Debye spatial autocorrelation function, pair distance distribution function and intraparticle structure factor (form factor) are calculated and compared to the corresponding scattering functions of reference systems of hard sphere and concentric core-shell particles with identical sizes. Based on our theoretical calculations, we find that the broken centrosymmetry, originating from the mobility of the trapped yolk, results in an imaginary scattering amplitude. As a result, it contributes an additional destructive interference term which smears certain features present in the scattering functions of the reference systems. Based on our theoretical models, we present the prospect of jointly using small angle neutron and x-ray scattering techniques to quantitatively determine the structural characteristics of yolk-shell particles.

Li, Xin [ORNL] [ORNL; Liu, Kao-Hsiang [National Taiwan University] [National Taiwan University; Wu, Bin [ORNL] [ORNL; Sanchez-Diaz, Luis E [ORNL] [ORNL; Smith, Gregory Scott [ORNL] [ORNL; Chen, Wei-Ren [ORNL] [ORNL

2013-01-01T23:59:59.000Z

343

Size-Controlled Dissolution of Organic-Coated Silver Nanoparticles  

Science Conference Proceedings (OSTI)

The solubility of Ag NPs can affect their toxicity and persistence in the environment. We measured the solubility of organic-coated silver nanoparticles (Ag NPs) having particle diameters ranging from 5 to 80 nm that were synthesized using various methods, and with different organic polymer coatings including poly(vinylpyrrolidone) and gum arabic. The size and morphology of Ag NPs were characterized by transmission electron microscopy (TEM). X-ray absorption fine structure (XAFS) spectroscopy and synchrotron-based total X-ray scattering and pair distribution function (PDF) analysis were used to determine the local structure around Ag and evaluate changes in crystal lattice parameters and structure as a function of NP size. Ag NP solubility dispersed in 1 mM NaHCO{sub 3} at pH 8 was found to be well correlated with particle size based on the distribution of measured TEM sizes as predicted by the modified Kelvin equation. Solubility of Ag NPs was not affected by the synthesis method and coating as much as by their size. Based on the modified Kelvin equation, the surface tension of Ag NPs was found to be {approx}1 J/m{sup 2}, which is expected for bulk fcc (face centered cubic) silver. Analysis of XAFS, X-ray scattering, and PDFs confirm that the lattice parameter, {alpha}, of the fcc crystal structure of Ag NPs did not change with particle size for Ag NPs as small as 6 nm, indicating the absence of lattice strain. These results are consistent with the finding that Ag NP solubility can be estimated based on TEM-derived particle size using the modified Kelvin equation for particles in the size range of 5-40 nm in diameter.

Ma, Rui; Levard, Clément; Marinakos, Stella M.; Cheng, Yingwen; Liu, Jie; Michel, F. Marc; Brown, Jr., Gordon E.; Lowry, Gregory V. (Duke)

2012-04-02T23:59:59.000Z

344

Method of particle trajectory recognition in particle flows of high particle concentration using a candidate trajectory tree process with variable search areas  

DOE Patents (OSTI)

The application relates to particle trajectory recognition from a Centroid Population comprised of Centroids having an (x, y, t) or (x, y, f) coordinate. The method is applicable to visualization and measurement of particle flow fields of high particle. In one embodiment, the centroids are generated from particle images recorded on camera frames. The application encompasses digital computer systems and distribution mediums implementing the method disclosed and is particularly applicable to recognizing trajectories of particles in particle flows of high particle concentration. The method accomplishes trajectory recognition by forming Candidate Trajectory Trees and repeated searches at varying Search Velocities, such that initial search areas are set to a minimum size in order to recognize only the slowest, least accelerating particles which produce higher local concentrations. When a trajectory is recognized, the centroids in that trajectory are removed from consideration in future searches.

Shaffer, Franklin D.

2013-03-12T23:59:59.000Z

345

The Particle Adventure | Particle decays and annihiliations ...  

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

like everyday objects and have momentum, but they also have wave properties. Quantum mechanics, the mathematical basis for our theories about particles, explains the behavior of...

346

The Particle Adventure | Particle decays and annihiliations ...  

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

Particle decays and annihiliations - Electron positron annhiliation When an electron and positron (antielectron) collide at high energy, they can annihilate to produce charm...

347

A Deformable Model for Bringing Particles in Anders Lindbjerg Dahl1  

E-Print Network (OSTI)

in for example a fermentation process, oil droplets in water, coal particles in a power plant, and spray the particle size. This can be handled by only including the particles in focus, but most of the depicted all particles in focus. Therefore we need to handle the out-of-focus blur, but this also provide

Dahl, Anders Lindbjerg

348

Engineered plant biomass feedstock particles  

DOE Patents (OSTI)

A novel class of flowable biomass feedstock particles with unusually large surface areas that can be manufactured in remarkably uniform sizes using low-energy comminution techniques. The feedstock particles are roughly parallelepiped in shape and characterized by a length dimension (L) aligned substantially with the grain direction and defining a substantially uniform distance along the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L. The particles exhibit a disrupted grain structure with prominent end and surface checks that greatly enhances their skeletal surface area as compared to their envelope surface area. The L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers. The W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers. The L.times.W dimensions define a pair of substantially parallel top surfaces characterized by some surface checking between longitudinally arrayed fibers. The feedstock particles are manufactured from a variety of plant biomass materials including wood, crop residues, plantation grasses, hemp, bagasse, and bamboo.

Dooley, James H. (Federal Way, WA); Lanning, David N. (Federal Way, WA); Broderick, Thomas F. (Lake Forest Park, WA)

2011-10-11T23:59:59.000Z

349

Aircraft Particle Inlets: State-of-the-Art and Future Needs  

Science Conference Proceedings (OSTI)

Aircraft inlets connect airborne instruments for particle microphysical and chemical measurements with the ambient atmosphere. These inlets may bias the measurements due to their potential to enhance or remove certain particle size fractions in ...

M. Wendisch; H. Coe; D. Baumgardner; J-L. Brenguier; V. Dreiling; M. Fiebig; P. Formenti; M. Hermann; M. Krämer; Z. Levin; R. Maser; E. Mathieu; P. Nacass; K. Noone; S. Osborne; J. Schneider; L. Schütz; A. Schwarzenböck; F. Stratmann; J. C. Wilson

2004-01-01T23:59:59.000Z

350

Effects of Aerosol Particles on the Microphysics of Coastal Stratiform Clouds  

Science Conference Proceedings (OSTI)

Aerosol particles can act as cloud condensation nuclei and thereby influence the number and size of droplets in clouds. Consequently, anthropogenic particles have the potential to influence global climate by increasing cloud albedo and decreasing ...

Cynthia H. Twohy; Philip A. Durkee; Barry J. Huebert; Robert J. Charlson

1995-04-01T23:59:59.000Z

351

Laboratory evaluation of fan/filter units' aerodynamic and energy performance  

SciTech Connect

The paper discusses the benefits of having a consistent testing method to characterize aerodynamic and energy performance of FFUs. It presents evaluation methods of laboratory-measured performance of ten relatively new, 1220 mm x 610 mm (or 4 ft x 2 ft) fan-filter units (FFUs), and includes results of a set of relevant metrics such as energy performance indices (EPI) based upon the sample FFUs tested. This paper concludes that there are variations in FFUs' performance, and that using a consistent testing and evaluation method can generate compatible and comparable FFU performance information. The paper also suggests that benefits and opportunities exist for our method of testing FFU energy performance to be integrated in future recommended practices.

Xu, Tengfang; Jeng, Ming-Shan

2004-07-27T23:59:59.000Z

352

Particle Physics Education Sites  

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

쭺-¶ 쭺-¶ Particle Physics Education Sites ¡]¥H¤U¬°¥~¤åºô¯¸¡^ quick reference Education and Information - National Laboratory Education Programs - Women and Minorities in Physics - Other Physics Sites - Physics Alliance - Accelerators at National Laboratories icon Particle Physics Education and Information sites: top Introduction: The Particle Adventure - an interactive tour of particle physics for everyone: the basics of theory and experiment. Virtual Visitor Center of the Stanford Linear Accelerator Center. Guided Tour of Fermilab, - overviews of several aspects of Particle Physics. Also check out Particle Physics concepts. Probing Particles - a comprehensive and straight-forward introduction to particle physics. Big Bang Science - approaches particle physics starting from the theoretical origin of the universe.

353

Laser particle sorter  

DOE Patents (OSTI)

Method and apparatus are provided for sorting particles, such as biological particles. A first laser is used to define an optical path having an intensity gradient which is effective to propel the particles along the path but which is sufficiently weak that the particles are not trapped in an axial direction. A probe laser beam is provided for interrogating the particles to identify predetermined phenotypical characteristics of the particles. A second laser beam is provided to intersect the driving first laser beam, wherein the second laser beam is activated by an output signal indicative of a predetermined characteristic. The second laser beam is switchable between a first intensity and a second intensity, where the first intensity is effective to displace selected particles from the driving laser beam and the second intensity is effective to propel selected particles along the deflection laser beam. The selected particles may then be propelled by the deflection beam to a location effective for further analysis. 2 figs.

Martin, J.C.; Buican, T.N.

1987-11-30T23:59:59.000Z

354

Submicrometer-sized hollow nickel spheres synthesized by autocatalytic reduction  

SciTech Connect

A facile method to fabricate submicrometer-sized hollow nickel spheres by autocatalyzing the redox reaction around a sacrificial colloidal particle surface is presented in this paper. The size distribution of these spheres can be controlled by regulating the concentration of the alkali solution. The hollow nickel particles were characterized by field emission scanning electron microscopy, transmission electron microscopy and X-ray powder diffraction. The hollow spheres produced by this process may have potential applications in many fields, including chemistry, biotechnology and materials science.

Deng Yida [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 1954, Huashan Road, Shanghai 200030 (China)]. E-mail: denyda@sjtu.edu.cn; Zhao Ling [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 1954, Huashan Road, Shanghai 200030 (China); Liu Lei [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 1954, Huashan Road, Shanghai 200030 (China); Shen Bin [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 1954, Huashan Road, Shanghai 200030 (China); Hu Wenbin [State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 1954, Huashan Road, Shanghai 200030 (China)

2005-10-06T23:59:59.000Z

355

Scavenging of Aerosol Particles by Precipitation  

Science Conference Proceedings (OSTI)

Airborne measurements have been made of aerosol particle size distributions (>0.01 ?m) in aged air masses, in the plumes from several coal power plants and a large Kraft paper mill, and in the emissions from a volcano, before and after rain or ...

Lawrence F. Radke; Peter V. Hobbs; Mark W. Eltgroth

1980-06-01T23:59:59.000Z

356

Computer simulation of grain growth with mobile particles  

SciTech Connect

The authors have studied the influence of mobile particles on grain growth kinetics. Three time regimes are evident in the observed coarsening. Initially, most grains grow unhindered by particles, with a growth exponent close to 1/2. As with static impurities, once the mean grain size approaches the average inter-particle separation the microstructure becomes effectively pinned. With mobile impurities, however, the loaded grain boundaries eventually resume their motion. The depinning time is observed to be independent of particle concentration. The observed kinetic behavior, growth exponents, and depinning time are in agreement with a simple theoretical model with different mobilities for boundaries with and without attached particles.

Hassold, G.N. [GMI Engineering and Management Inst., Flint, MI (United States). Dept. of Science and Mathematics] [GMI Engineering and Management Inst., Flint, MI (United States). Dept. of Science and Mathematics; Srolovitz, D.J. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering] [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

1995-05-15T23:59:59.000Z

357

Controlled emulsion droplet solvent evaporation for particle production  

E-Print Network (OSTI)

In this work, we are motivated by the need to produce particles of well-controlled size, shape and morphology for general application in catalysis, environmental remediation, nanomedicine, pharmaceuticals, the development ...

Chang, Emily P

2013-01-01T23:59:59.000Z

358

Optical Properties of Aerosol Particles over the Northeast Pacific  

Science Conference Proceedings (OSTI)

In July 2002, atmospheric aerosol measurements were conducted over the northeast Pacific Ocean as part of the Subarctic Ecosystem Response to Iron Enhancement Study (SERIES). The following aerosol quantities were measured: particle number size ...

Julia Marshall; Ulrike Lohmann; W. Richard Leaitch; Nicole Shantz; Lisa Phinney; Desiree Toom-Sauntry; Sangeeta Sharma

2005-08-01T23:59:59.000Z

359

Size Effect of Ruthenium Nanoparticles in Catalytic Carbon Monoxide Oxidation  

Science Conference Proceedings (OSTI)

Carbon monoxide oxidation over ruthenium catalysts has shown an unusual catalytic behavior. Here we report a particle size effect on CO oxidation over Ru nanoparticle (NP) catalysts. Uniform Ru NPs with a tunable particle size from 2 to 6 nm were synthesized by a polyol reduction of Ru(acac){sub 3} precursor in the presence of poly(vinylpyrrolidone) stabilizer. The measurement of catalytic activity of CO oxidation over two-dimensional Ru NPs arrays under oxidizing reaction conditions (40 Torr CO and 100 Torr O{sub 2}) showed an activity dependence on the Ru NP size. The CO oxidation activity increases with NP size, and the 6 nm Ru NP catalyst shows 8-fold higher activity than the 2 nm catalysts. The results gained from this study will provide the scientific basis for future design of Ru-based oxidation catalysts.

Joo, Sang Hoon; Park, Jeong Y.; Renzas, J. Russell; Butcher, Derek R.; Huang, Wenyu; Somorjai, Gabor A.

2010-04-04T23:59:59.000Z

360

Field Observations of In-Cloud Nucleation and the Modification of Atmospheric Aerosol Size Distributions after Cloud Evaporation  

Science Conference Proceedings (OSTI)

The authors measured aerosol and droplet size distributions in the range from 0.1 to 50 µm, concentrations and sizes of precipitation particles, concentrations of condensation nuclei, and state parameters in and in the vicinity of a towering ...

A. J. Alkezweeny

1995-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

SMALL PARTICLE HEAT EXCHANGERS  

E-Print Network (OSTI)

ON ~m Small Particle Heat Exchangers Arion J. Hunt June 1978d. LBL 7841 Small Particle Heat Exchangers by Arlon J. Huntgenerally to non-solar heat exchangers. These may be of the

Hunt, A.J.

2011-01-01T23:59:59.000Z

362

The Particle Adventure  

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

Boson - 2 Finding the Mass of the Higgs Boson - Part 2 Adding up the masses of the particles from the Higgs decay doesn't work, because these particles have enormous kinetic energy...

363

The Particle Adventure | Glossary  

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

Fermion Any particle that has odd-half-integer (12, 32, ...) intrinsic angular momentum (spin), measured in units of h-bar. All particles are either fermions or bosons. Fermions...

364

The Particle Adventure | Glossary  

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

Interaction A process in which a particle decays or it responds to a force due to the presence of another particle (as in a collision). The four fundamental interactions are...

365

The Particle Adventure | Glossary  

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

Pauli Exclusion Principle The principle that no two particles in the same quantum state may exist in the same place at the same time. Particles that obey this principle are called...

366

The Particle Adventure | Glossary  

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

Particle A particle with no internal substructure. In the Standard Model the quarks, leptons, photons, gluons, W+ and W- bosons, and the Z bosons are fundamental. All other objects...

367

The Particle Adventure | Glossary  

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

Antiparticle For most particle types (and every fermion type) there is another particle type that has exactly the same mass but the opposite value of all other charges (quantum...

368

The Particle Adventure | Glossary  

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

Synchrotron A type of circular accelerator in which the particles travel in synchronized bunches at fixed radius...

369

The Particle Adventure | Glossary  

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

Fermilab Fermi National Accelerator Laboratory in Batavia, Illinois (near Chicago). Named for particle physics pioneer Enrico Fermi...

370

The Particle Adventure | Glossary  

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

CERN CERN (European Laboratory for Particle Physics) is the major European international accelerator laboratory located near Geneva, Switzerland...

371

The Particle Adventure | Glossary  

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

Tracking The reconstruction of a "track" left in a detector by the passage of a particle through the...

372

The Particle Adventure | How do we experiment with tiny particles...  

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

Accelerators and particle detectors - How do we experiment with tiny particles? - How to obtain particles to accelerate Electrons: Heating a metal causes electrons to be ejected. A...

373

The Particle Adventure | How do we experiment with tiny particles...  

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

Accelerators and particle detectors - How do we experiment with tiny particles? - Detector shapes Physicists are curious about the events that occur during and after a particle's...

374

Parameterizing Size Distribution in Ice Clouds  

SciTech Connect

PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 µm) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 µm), known as the “small mode”. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 µm wavelength relative to 11 µm wavelength due to the process of wave resonance or photon tunneling more active at 12 µm. This makes the 12/11 µm absorption optical depth ratio (or equivalently the 12/11 µm Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

DeSlover, Daniel; Mitchell, David L.

2009-09-25T23:59:59.000Z

375

The Particle Adventure | Particle decays and annihiliations ...  

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

Particle decays and annihiliations - Half life A lump of uranium left to itself will gradually decay, one nucleus at a time. The rate of decay is measured by how long it would take...

376

The Particle Adventure | Particle decays and annihiliations ...  

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

mass in a radioactive decay go? Recall that we said that when uranium decays into thorium and an alpha particle, 0.0046 u of mass appears to have been lost. As Einstein said,...

377

Numerical Studies of Particle Laden Flow in Dispersed Phase  

E-Print Network (OSTI)

To better understand the hydrodynamic flow behavior in turbulence, Particle-Fluid flow have been studied using our Direct Numerical(DNS) based software DSM on MUSCL-QUICK and finite volume algorithm. The particle flow was studied using Eulerian-Eulerian Quasi Brownian Motion(QBM) based approach. The dynamics is shown for various particle sizes which are very relevant to spray mechanism for Industrial applications and Bio medical applications.

Dutta, R

2012-01-01T23:59:59.000Z

378

Usage by Job Size  

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

Usage by Job Usage by Job Size Table Usage by Job Size Table page loading animation Usage Query Interface System All Hopper Edison Carver Planck Matgen Franklin Hopper 1 Magellan Dirac Bassi Jacquard Seaborg User Account (Repo) Execution Queue All Debug Interactive Premium Regular Short Regular Long Regular Small Regular Medium Regular Big Regular Extra Big Killable Low Transfer IO Task Special System Serial Big Memory Westmere === Inactive === Magellan Serial Magellan Short Magellan Small Magellan Medium Magellan Big Magellan Long Regular 1 Regular 1 Long Regular 16 Regular 32 Regular 48 Full Config Seaborg Serial Batch 16 Batch 32 Batch 64 Submit Queue all interactive debug premium regular low DOE Office all ASCR BER BES FES HEP NP Summary for jobs that completed after Jan Feb Mar Apr May Jun July Aug Sep Oct Nov Dec 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 @ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 : 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59

379

Measurements of Aerodynamic Roughness, Bowen Ratio, and Atmospheric Surface Layer Height by Eddy Covariance and Tethersonde Systems Simultaneously over a Heterogeneous Rice Paddy  

Science Conference Proceedings (OSTI)

The aerodynamic roughness, Bowen ratio, and friction velocity were measured over a rice paddy using tethersonde and eddy covariance (EC) systems. In addition, the height ranges of the atmospheric inertial sublayer (ISL) were derived using the ...

Jeng-Lin Tsai; Ben-Jei Tsuang; Po-Sheng Lu; Ken-Hui Chang; Ming-Hwi Yao; Yuan Shen

2010-04-01T23:59:59.000Z

380

Significant Decrease of Uncertainties in Sensible Heat Flux Simulation Using Temporally Variable Aerodynamic Roughness in Two Typical Forest Ecosystems of China  

Science Conference Proceedings (OSTI)

Aerodynamic roughness length zom is an important parameter for reliably simulating surface fluxes. It varies with wind speed, atmospheric stratification, terrain, and other factors. However, it is usually considered a constant. It is known that ...

Yanlian Zhou; Weimin Ju; Xiaomin Sun; Xuefa Wen; Dexin Guan

2012-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Physics Out Loud - Particle Accelerator  

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

Nucleus Previous Video (Nucleus) Physics Out Loud Main Index Next Video (Particle Resonance) Particle Resonance Particle Accelerator Andrew Hutton, Director of Accelerators at...

382

Heating dynamics of CO{sub 2}-laser irradiated silica particles with evaporative shrinking: Measurements and modeling  

SciTech Connect

The heating dynamics of CO{sub 2}-laser heated micron-sized particles were determined for temperatures <3500 K measured using infrared imaging. A coupled mass and energy conservation model is derived to predict single particle temperatures and sizes, which were compared with data from particles deposited on non-absorbing substrates to assess the relevant heat transfer processes. Analysis reveals substrate conduction dominates all other heat losses, while laser absorption determined from Mie theory is strongly modulated by particle evaporative shrinking. This study provides insights into the light coupling and heating of particle arrays where the material optical properties are temperature-dependent and particle size changes are significant.

Elhadj, S.; Qiu, S. R.; Stolz, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Monterrosa, A. M. [Department of Nuclear Engineering and Department of Materials Science and Engineering, University of California, Berkeley, California 94704 (United States)

2012-05-01T23:59:59.000Z

383

Particle-jet interactions in an MHD second stage combustor  

DOE Green Energy (OSTI)

An Argonne two-phase combustion flow computer code is used to simulate reacting flows to aid in the development of an advanced combustor for magnetohydrodynamic power generation. The combustion code is a general hydrodynamics computer code for two-phase, two- dimensional, steady state, turbulent, and reacting flows, based on mass, momentum, and energy conservation laws for multiple gas species and particles. The combustion code includes turbulence, integral combustion, and particle evaporation submodels. A recently developed integral combustion submodel makes calculations more efficient and more stable while still preserving the major physical effects of the complex combustion processes. The combustor under investigation is a magnetohydrodynamic second stage combustor in which opposed jets of oxidizer are injected into a confined cross-stream of hot coal gas flow following a first stage swirl combustor. The simulation is intended to enhance the understanding the of seed particle evaporation in the combustor and evaluate the effects of combustor operating conditions on seed particle evaporation and vapor dispersion, which directly affect overall magnetohydrodynamic power generation. Computation results show that oxidizer jet angle and particle size may greatly affect particle evaporation and vapor dispersion. At a jet angle about 130 degrees, particle evaporation rate is the highest because of the highest average gas temperature. As particle size increases beyond 10 microns in diameter, the effects of particle size on wall deposition rate, evaporation delay, and downstream seed vapor dispersion become more pronounced. 16 refs., 10 figs.

Lottes, S.A.; Chang, S.L.

1992-01-01T23:59:59.000Z

384

Particle-jet interactions in an MHD second stage combustor  

DOE Green Energy (OSTI)

An Argonne two-phase combustion flow computer code is used to simulate reacting flows to aid in the development of an advanced combustor for magnetohydrodynamic power generation. The combustion code is a general hydrodynamics computer code for two-phase, two- dimensional, steady state, turbulent, and reacting flows, based on mass, momentum, and energy conservation laws for multiple gas species and particles. The combustion code includes turbulence, integral combustion, and particle evaporation submodels. A recently developed integral combustion submodel makes calculations more efficient and more stable while still preserving the major physical effects of the complex combustion processes. The combustor under investigation is a magnetohydrodynamic second stage combustor in which opposed jets of oxidizer are injected into a confined cross-stream of hot coal gas flow following a first stage swirl combustor. The simulation is intended to enhance the understanding the of seed particle evaporation in the combustor and evaluate the effects of combustor operating conditions on seed particle evaporation and vapor dispersion, which directly affect overall magnetohydrodynamic power generation. Computation results show that oxidizer jet angle and particle size may greatly affect particle evaporation and vapor dispersion. At a jet angle about 130 degrees, particle evaporation rate is the highest because of the highest average gas temperature. As particle size increases beyond 10 microns in diameter, the effects of particle size on wall deposition rate, evaporation delay, and downstream seed vapor dispersion become more pronounced. 16 refs., 10 figs.

Lottes, S.A.; Chang, S.L.

1992-07-01T23:59:59.000Z

385

Adhesive particle shielding  

DOE Patents (OSTI)

An efficient device for capturing fast moving particles has an adhesive particle shield that includes (i) a mounting panel and (ii) a film that is attached to the mounting panel wherein the outer surface of the film has an adhesive coating disposed thereon to capture particles contacting the outer surface. The shield can be employed to maintain a substantially particle free environment such as in photolithographic systems having critical surfaces, such as wafers, masks, and optics and in the tools used to make these components, that are sensitive to particle contamination. The shield can be portable to be positioned in hard-to-reach areas of a photolithography machine. The adhesive particle shield can incorporate cooling means to attract particles via the thermophoresis effect.

Klebanoff, Leonard Elliott (Dublin, CA); Rader, Daniel John (Albuquerque, NM); Walton, Christopher (Berkeley, CA); Folta, James (Livermore, CA)

2009-01-06T23:59:59.000Z

386

Engineered plant biomass feedstock particles  

DOE Patents (OSTI)

A new class of plant biomass feedstock particles characterized by consistent piece size and shape uniformity, high skeletal surface area, and good flow properties. The particles of plant biomass material having fibers aligned in a grain are characterized by a length dimension (L) aligned substantially parallel to the grain and defining a substantially uniform distance along the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L. In particular, the L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers, the W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers, and the L.times.W dimensions define a pair of substantially parallel top and bottom surfaces. The L.times.W surfaces of particles with L/H dimension ratios of 4:1 or less are further elaborated by surface checking between longitudinally arrayed fibers. The length dimension L is preferably aligned within 30.degree. parallel to the grain, and more preferably within 10.degree. parallel to the grain. The plant biomass material is preferably selected from among wood, agricultural crop residues, plantation grasses, hemp, bagasse, and bamboo.

Dooley, James H. (Federal Way, WA); Lanning, David N. (Federal Way, WA); Broderick, Thomas F. (Lake Forest Park, WA)

2012-04-17T23:59:59.000Z

387

Mathematical Modeling of Aerodynamic Space -to - Surface Flight with Trajectory for Avoid Intercepting Process for Safety and Security Issues  

E-Print Network (OSTI)

The research project has been made for mathematical modeling of aerospace system Space-to-Surface for avoid intercepting process by flight objects Surface-to-Air. The research has been completed and created mathematical models which used for research and statistical analysis. In mathematical modeling has been including a few models: Model of atmosphere, Model of speed of sound, Model of flight head in space, Model of flight in atmosphere, Models of navigation and guidance, Model and statistical analysis of approximation of aerodynamic characteristics. Modeling has been created for a Space-to-Surface system defined for an optimal trajectory in terminal phase. The modeling includes models for simulation atmosphere, aerodynamic flight and navigation by an infrared system. The modeling simulation includes statistical analysis of the modeling results.

Gorneff, Serge

2009-01-01T23:59:59.000Z

388

Coal Particle Flow Patterns for O2 Enriched, Low NOx Burners  

SciTech Connect

This project involved a systematic investigation examining the effect of near-flame burner aerodynamics on standoff distance and stability of turbulent diffusion flames and the resultant NO{sub x} emissions from actual pulverized coal diffusion flames. Specifically, the scope of the project was to understand how changes in near-flame aerodynamics and transport air oxygen partial pressure can influence flame attachment and coal ignition, two properties essential to proper operation of low NO{sub x} burners. Results from this investigation utilized a new 2M tall, 0.5m in diameter combustor designed to evaluate near-flame combustion aerodynamics in terms of transport air oxygen partial pressure (Po{sub 2}), coal fines content, primary fuel and secondary air velocities, and furnace wall temperature furnish insight into fundamental processes that occur during combustion of pulverized coal in practical systems. Complementary cold flow studies were conducted in a geometrically similar chamber to analyze the detailed motion of the gas and particles using laser Doppler velocimetry. This final technical report summarizes the key findings from our investigation into coal particle flow patterns in burners. Specifically, we focused on the effects of oxygen enrichment, the effect of fines, and the effect of the nozzle velocity ratio on the resulting flow patterns. In the cold flow studies, detailed measurements using laser Doppler velocimetry (LDV) were made to determine the details of the flow. In the hot flow studies, observations of flame stability and measurements of NO{sub x} were made to determine the effects of the flow patterns on burner operation.

Jennifer Sinclair Curtis

2005-08-01T23:59:59.000Z

389

Film Cooling, Heat Transfer and Aerodynamic Measurements in a Three Stage Research Gas Turbine  

E-Print Network (OSTI)

The existing 3-stage turbine research facility at the Turbomachinery Performance and Flow Research Laboratory (TPFL), Texas A and M University, is re-designed and newly installed to enable coolant gas injection on the first stage rotor platform to study the effects of rotation on film cooling and heat transfer. Pressure and temperature sensitive paint techniques are used to measure film cooling effectiveness and heat transfer on the rotor platform respectively. Experiments are conducted at three turbine rotational speeds namely, 2400rpm, 2550rpm and 3000rpm. Interstage aerodynamic measurements with miniature five hole probes are also acquired at these speeds. The aerodynamic data characterizes the flow along the first stage rotor exit, second stage stator exit and second stage rotor exit. For each rotor speed, film cooling effectiveness is determined on the first stage rotor platform for upstream stator-rotor gap ejection, downstream discrete hole ejection and a combination of upstream gap and downstream hole ejection. Upstream coolant ejection experiments are conducted for coolant to mainstream mass flow ratios of MFR=0.5%, 1.0%, 1.5% and 2.0% and downstream discrete hole injection tests corresponding to average hole blowing ratios of M = 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 and 2.0 for each turbine speed. To provide a complete picture of hub cooling under rotating conditions, experiments with simultaneous injection of coolant gas through upstream and downstream injection are conducted for an of MFR=1% and Mholes=0.75, 1.0 and 1.25 for the three turbine speeds. Heat transfer coefficients are determined on the rotor platform for similar upstream and downstream coolant injection. Rotation is found to significantly affect the distribution of coolant on the platform. The measured effectiveness magnitudes are lower than that obtained with numerical simulations. Coolant streams from both upstream and downstream injection orient themselves towards the blade suction side. Passage vortex cuts-off the coolant film for the lower MFR for upstream injection. As the MFR increases, the passage vortex effects are diminished. Effectiveness was maximum when Mholes was closer to one as the coolant ejection velocity is approximately equal to the mainstream relative velocity for this blowing ratio. Heat transfer coefficient and film cooling effectiveness increase with increasing rotational speed for upstream rotor stator gap injection while for downstream hole injection the maximum effectiveness and heat transfer coefficients occur at the reference speed of 2550rpm.

Suryanarayanan, Arun

2009-05-01T23:59:59.000Z

390

Dog's Heart Size and Activity  

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Dog's Heart Size and Activity Name: Addie Status: Student Grade: 4-5 Location: IN Country: USA Date: Winter 2009-2010 Question: Does the size of a dog affect it's heart rate before...

391

Automated size analysis for OCL  

Science Conference Proceedings (OSTI)

An essential tool in object oriented modeling is the specification of cardinalities of associations between classes. In Object Constraint Language (OCL) such constraints are expressed as conditions on the sizes of the collections that correspond to associations. ... Keywords: OCL, size abstraction, size analysis

Fang Yu; Tevfik Bultan; Erik Peterson

2007-09-01T23:59:59.000Z

392

Inflow Characterization and Aerodynamics Measurements on a SWT-2.3-101 Wind Turbine: Preprint  

DOE Green Energy (OSTI)

Post processing techniques for aerodynamic data acquired from a Siemens SWT-2.3-101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research And Development Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally the pressure measurements are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D CFD results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the nondimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

Medina, P.; Singh, M.; Johansen, J.; Jove, A.; Fingersh, L.; Schreck, S.

2012-01-01T23:59:59.000Z

393

Inflow Characterization and Aerodynamics Measurements on a SWT-2.3-101 Wind Turbine  

SciTech Connect

Post processing techniques for aerodynamic data acquired from a Siemens SWT-2.3101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research and Development Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally, the pressure measurements are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D Computational Fluid Dynamics (CFD) results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the non-dimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

Medina, P.; Singh, M.; Johansen, J.; Jove, A. R.; Fingersh, L.; Schreck, S.

2012-01-01T23:59:59.000Z

394

Phospholipid-assisted synthesis of size-controlled gold nanoparticles  

SciTech Connect

Morphology and size control of gold nanoparticles (AuNPs) by phospholipids (PLs) has been reported. It was found that gold entities could form nanostructures with different sizes controlled by PLs in an aqueous solution. During the preparation of 1.5 nm gold seeds, AuNPs were obtained from the reduction of gold complex by sodium borohydride and capped by citrate for stabilization. With the different ratios between seed solution and growth solution, which was composed by gold complex and PLs, gold seeds grew into larger nanoparticles step by step until enough large size up to 30 nm. The main discovery of this work is that common biomolecules, such as PLs can be used to control nanoparticle size. This conclusion has been confirmed by transmission electron micrographs, particle size analysis, and UV-vis spectra.

He Peng [Department of Chemistry, North Carolina State University, Raleigh, NC 27695 (United States)]. E-mail: phe@ncsu.edu; Zhu Xinyuan [Instrumental Analysis Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030 (China)]. E-mail: xyzhu@sjtu.edu.cn

2007-07-03T23:59:59.000Z

395

Laser ablation of nanoscale particles with 193 nm light  

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

Laser ablation of nanoscale particles with 193 nm light Laser ablation of nanoscale particles with 193 nm light Title Laser ablation of nanoscale particles with 193 nm light Publication Type Journal Article Year of Publication 2007 Authors Choi, Jong Hyun, Donald Lucas, and Catherine P. Koshland Journal Journal of Physics: Conference Series Volume 59 Start Page 54 Issue 1 Pagination 54-59 Abstract Laser interaction with nanoscale particles is distinct and different from laser-bulk material interaction, where a hot plasma is normally created. Here, we review our studies on 193 nm laser ablation of various nanoscale particles including NaCl, soot, polystyrene, and gold. The 20 ns laser beam with fluences up to 0.3 J/cm2 irradiates nanoparticles in a gas stream at laser repetition rates from 10 to 100 Hz. The particle size distributions before and after irradiation are measured with a scanning mobility particle sizer (SMPS), and particle morphology is examined with electron microscopy. All the nanomaterials studied exhibit a similar disintegration pattern and similar particle formation characteristics. No broadband emission associated with particle heating or optical breakdown is observed. The nanoparticles formed after irradiation have a smaller mean diameter and an order of magnitude higher number concentration with a more spherical shape compared to the original particles. We use the photon-atom ratio (PAR) to interpret the laser-particle interaction energetics.

396

Surrogate protein particle standards  

Science Conference Proceedings (OSTI)

... The large particles may be useful as a standard for the counting of ... drugs require visual inspection, at present there are no standards available for ...

2013-09-10T23:59:59.000Z

397

Particle Physics Education Sites  

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Particle Physics Education Sites quick reference Education and Information - National Laboratory Education Programs - Women and Minorities in Physics - Other Physics Sites -...

398

Nuclear & Particle Physics Directorate  

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at RHIC or the AGS should be submitted to the Associate Laboratory Director for Nuclear and Particle Physics, presently Steve Vigdor, Bldg. 510F, Brookhaven National...

399

Nuclear & Particle Physics Directorate  

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

Brookhaven National Laboratory Nuclear and Particle Physics Program Advisory Committee Meeting 12-14 September 2006 Tuesday, 12 September Room 2-160, Bldg. 510 (Physics) 0900...

400

Nuclear & Particle Physics Directorate  

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

Brookhaven National Laboratory Nuclear and Particle Physics Program Advisory Committee Meeting June 15-16, 2009 Agenda Reference Documents Letter to Barbara Jacak and Nu Xu (129...

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

Nuclear & Particle Physics Directorate  

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

Brookhaven National Laboratory Nuclear and Particle Physics Program Advisory Committee Meeting 7-8 June 2012 Agenda Related Documents: PHENIX Beam Use Proposal, STAR Beam Use...

402

The Particle Adventure | Glossary  

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

Electron The least massive electrically-charged particle, hence absolutely stable. It is the most common lepton, with electric charge -1...

403

The Particle Adventure  

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

The discovery of the Higgs boson is an enormous clue about the mechanism for giving mass to fundamental particles, as conceived by Higgs, Brout, Englert, Guralnik, Hagen, and...

404

Particle Data Group - Products  

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Group HOME: pdgLive Summary Tables Reviews, Tables, Plots Particle Listings Europe, Africa, Middle East, India, Pakistan, Russia and all other countries For copies of: ...

405

FPGA particle graphics hardware.  

E-Print Network (OSTI)

??Particle graphics simulations are well suited for modeling phenomena such as water, cloth, explosions, fire, smoke, and clouds. They are normally realized in software, as… (more)

Beeckler, John Sachs.

2006-01-01T23:59:59.000Z

406

The Particle Adventure | Glossary  

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

Charge Conservation The observation that electric charge is conserved in any process of transformation of one group of particles into another...

407

The Particle Adventure | Glossary  

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Standard Model Physicists have developed a theory of fundamental particles and interactions called the Standard Model. This site describes various aspects of this model...

408

The Particle Adventure | Glossary  

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

Weak Interaction The interaction responsible for all processes in which flavor changes, hence for the instability of heavy quarks and leptons, and particles that contain them. Weak...

409

The Particle Adventure | Glossary  

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

Antimatter Material made from antifermions. We define the fermions that are common in our universe as matter and their antiparticles as antimatter. In the particle theory there is...

410

The Particle Adventure | Glossary  

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

Z Boson A carrier particle of the weak interactions. It is involved in all weak processes that do not change flavor...

411

The Particle Adventure | Glossary  

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

W+, W- Boson A carrier particle of the weak interactions. It is involved in all electric-charge-changing weak processes...

412

The Particle Adventure | Glossary  

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Accelerator A machine used to accelerate particles to high speeds, and thus high energy compared to their rest-mass energy...

413

The Particle Adventure | Glossary  

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

Conservation When a quantity is always the same before and after a particle reaction, it is said to be conserved. Such quantities include electric charge, energy, and momentum...

414

Particle Event Pictures  

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- Identifying Particles - D0 Detector - CDF Detector - Links Project Contact: Thomas Jordan - jordant@fnal.gov Web Maintainer: qnet-webmaster@fnal.gov Last Update: April 13, 2001...

415

Quantum size effects in classical hadrodynamics  

SciTech Connect

The author discusses future directions in the development of classical hydrodynamics for extended nucleons, corresponding to nucleons of finite size interacting with massive meson fields. This new theory provides a natural covariant microscopic approach to relativistic nucleus-nucleus collisions that includes automatically spacetime nonlocality and retardation, nonequilibrium phenomena, interactions among all nucleons, and particle production. The present version of the theory includes only the neutral scalar ({sigma}) and neutral vector ({omega}) meson fields. In the future, additional isovector pseudoscalar ({pi}{sup +}, {pi}{sup {minus}}, {pi}{sup 0}), isovector vector ({rho}{sup +}, {rho}{sup {minus}}, {rho}{sup 0}), and neutral pseudoscalar ({eta}) meson fields should be incorporated. Quantum size effects should be included in the equations of motion by use of the spreading function of Moniz and Sharp, which generates an effective nucleon mass density smeared out over a Compton wavelength. However, unlike the situation in electrodynamics, the Compton wavelength of the nucleon is small compared to its radius, so that effects due to the intrinsic size of the nucleon dominate.

Nix, J.R.

1994-03-01T23:59:59.000Z

416

Thermophoretic separation of aerosol particles from a sampled gas stream  

DOE Patents (OSTI)

A method for separating gaseous samples from a contained atmosphere that includes aerosol particles uses the step of repelling particles from a gas permeable surface or membrane by heating the surface to a temperature greater than that of the surrounding atmosphere. The resulting thermophoretic forces maintain the gas permeable surface clear of aerosol particles. The disclosed apparatus utilizes a downwardly facing heated plate of gas permeable material to combine thermophoretic repulsion and gravity forces to prevent particles of any size from contacting the separating plate surfaces.

Postma, Arlin K. (Halfway, OR)

1986-01-01T23:59:59.000Z

417

Method for ion implantation induced embedded particle formation via reduction  

DOE Patents (OSTI)

A method for ion implantation induced embedded particle formation via reduction with the steps of ion implantation with an ion/element that will chemically reduce the chosen substrate material, implantation of the ion/element to a sufficient concentration and at a sufficient energy for particle formation, and control of the temperature of the substrate during implantation. A preferred embodiment includes the formation of particles which are nano-dimensional (<100 m-n in size). The phase of the particles may be affected by control of the substrate temperature during and/or after the ion implantation process.

Hampikian, Janet M (Decatur, GA); Hunt, Eden M (Atlanta, GA)

2001-01-01T23:59:59.000Z

418

Improvements of Droplet Size Distribution Measurements with the Fast-FSSP (Forward Scattering Spectrometer Probe)  

Science Conference Proceedings (OSTI)

The basics of single particle measurements are discussed and illustrated with measurements of the droplet size distribution with an optical spectrometer, the Forward Scattering Spectrometer Probe (FSSP), and its improved version, the Fast-FSSP. ...

Jean-Louis Brenguier; Thierry Bourrianne; Afraniode Araujo Coelho; Jacques Isbert; Robert Peytavi; Dominique Trevarin; Perry Weschler

1998-10-01T23:59:59.000Z

419

Effect of reaction conditions on size and morphology of ultrasonically prepared Ni(OH)2 powders  

E-Print Network (OSTI)

used as a hydrogenation catalyst and in the ceramic industry for sintered fritz and glazes morphology and small particle size is also important for producing metallic nanoparticles for ceramic matrix

Suslick, Kenneth S.

420

Measurements of Aerosol Size Distributions in the Lower Troposphere over Northern Europe  

Science Conference Proceedings (OSTI)

Airborne measurements of particle size distributions were made at several altitudes within and above the mixing layer at sites near Ahlhorn and Meppen (West Germany), Rodby (Denmark), and Bruz (France). The distributions were measured over the ...

Bruce W. Fitch; Ted S. Cress

1981-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerodynamic particle sizing" 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

The Sensitivity of the Radiation Budget in a Climate Simulation to Neglecting the Effect of Small Ice Particles  

Science Conference Proceedings (OSTI)

The sensitivity of the atmospheric radiation budget to ignoring small ice particles (D ? 100 ?m) in parameterization of the mean effective size of ice particles was investigated by using the Canadian Centre for Climate Modelling and Analysis (...

Faisal S. Boudala; George A. Isaac; N. A. McFarlane; J. Li

2007-07-01T23:59:59.000Z

422

Cloud Droplet Residual Particle Microphysics in Marine Stratocumulus Clouds Observed during the Monterey Area Ship Track Experiment  

Science Conference Proceedings (OSTI)

The effect of marine boundary layer pollution level (as determined by the aerosol particle number concentration) on the size distribution of aerosol particles that formed cloud droplets in marine stratiform clouds is examined. In situ ...

Elisabeth Öström; Kevin J. Noone; Robert A. Pockalny

2000-08-01T23:59:59.000Z

423

Airflow structures and nano-particle deposition in a human upper airway model  

Science Conference Proceedings (OSTI)

Considering a human upper airway model, or equivalently complex internal flow conduits, the transport and deposition of nano-particles in the 1-150 nm diameter range are simulated and analyzed for cyclic and steady flow conditions. Specifically, using ... Keywords: computational fluid-particle dynamics simulation, human airways, inspiratory flow, nano-size particle deposition

Z. Zhang; C. Kleinstreuer

2004-07-01T23:59:59.000Z

424

Some Particle Properties  

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

Particle Properties Particle Properties An Article Written Originally for Midlevel Teachers Back A particle, increasing its speed because of some force acting on it, gains energy of motion. An electron (negatively charged) gains one electron volt (eV) of energy in accelerating through a vacuum from the negative end to the positive end of a one-volt battery. The one eV of energy is given up to other particles as the electron crashes into the positive end. A proton (positively charged) traveling from positive to negative pole through the vacuum would also gain one eV of energy and give it up in its collision with particles in the negative end. This proton collision is similar to the proton beam collision with a target at Fermilab, but at Fermilab the proton energy is much greater.

425

Imaging alpha particle detector  

DOE Patents (OSTI)

A method and apparatus for detecting and imaging alpha particles sources is described. A conducting coated high voltage electrode (1) and a tungsten wire grid (2) constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source (3) to be quantitatively or qualitatively analyzed. A thin polyester film window (4) allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

Anderson, David F. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

426

HIGH ENERGY PARTICLE ACCELERATOR  

DOE Patents (OSTI)

An improved apparatus is presented for focusing charged particles in an accelerator. In essence, the invention includes means for establishing a magnetic field in discrete sectors along the path of moving charged particles, the magnetic field varying in each sector in accordance with the relation. B = B/ sub 0/ STAln (r-r/sub 0/)/r/sub 0/!, where B/sub 0/ is the value of the magnetic field at the equilibrium orbit of radius r/sub 0/ of the path of the particles, B equals the magnetic field at the radius r of the chamber and n equals the magnetic field gradient index, the polarity of n being abruptly reversed a plurality of times as the particles travel along their arcuate path. With this arrangement, the particles are alternately converged towards the axis of their equillbrium orbit and diverged therefrom in successive sectors with a resultant focusing effect.

Courant, E.D.; Livingston, M.S.; Snyder, H.S.

1959-04-14T23:59:59.000Z

427

Impacts of Venturi Turbulent Mixing on the Size Distributions of Sodium Chloride and Dioctyl-Phthalate Aerosols  

DOE Green Energy (OSTI)

Internal combustion engines are a major source of airborne particulate matter (PM). The size of the engine PM is in the sub-micrometer range. The number of engine particles per unit volume is high, normally in the range of 10{sup 12} to 10{sup 14}. To measure the size distribution of the engine particles dilution of an aerosol sample is required. A diluter utilizing a venturi ejector mixing technique is commercially available and tested. The purpose of this investigation was to determine if turbulence created by the ejector in the mini-dilutor changes the size of particles passing through it. The results of the NaCl aerosol experiments show no discernible difference in the geometric mean diameter and geometric standard deviation of particles passing through the ejector. Similar results were found for the DOP particles. The ratio of the total number concentrations before and after the ejector indicates that a dilution ratio of approximately 20 applies equally for DOP and NaCl particles. This indicates the dilution capability of the ejector is not affected by the particle composition. The statistical analysis results of the first and second moments of a distribution indicate that the ejector may not change the major parameters (e.g., the geometric mean diameter and geometric standard deviation) characterizing the size distributions of NaCl and DOP particles. However, when the skewness was examined, it indicates that the ejector modifies the particle size distribution significantly. The ejector could change the skewness of the distribution in an unpredictable and inconsistent manner. Furthermore, when the variability of particle counts in individual size ranges as a result of the ejector is examined, one finds that the variability is greater for DOP particles in the size range of 40-150 nm than for NaCl particles in the size range of 30 to 350 nm. The numbers or particle counts in this size region are high enough that the Poisson counting errors are small (<10%) compared with the tail regions. This result shows that the ejector device could have a higher bin-to-bin counting uncertainty for ''soft'' particles such as DOP than for a solid dry particle like NaCl. The results suggest that it may be difficult to precisely characterize the size distribution of particles ejected from the mini-dilution system if the particle is not solid.

Cheng, M-D.

2000-08-23T23:59:59.000Z

428

Particle production from Q-balls  

E-Print Network (OSTI)

Non topological solitons, Q-balls can arise in many particle theories with U(1) global symmetries. As was shown by Cohen et al. \\cite{Qballscohen}, if the corresponding scalar field couples to massless fermions, large Q-balls are unstable and evaporate, producing a fermion flux proportional to the Q-ball's surface. In this paper we analyse Q-ball instabilities as a function of Q-ball size ans fermion mass. In particular, we construct an exact quantum-mechanical description of the evaporating Q-ball. This new construction provides an alternative method to compute Q-Ball's evaporation rates. We shall also find the new expression for the upper bound on evaporation as a function of the produced fermion mass and study the effects of Q ball's size on particle production.

Stephen Clark

2005-10-06T23:59:59.000Z

429

SLAC Library - Online Particle Physics Information  

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

May 2002 May 2002 This list describes a broad set of online resources that are of value to the particle physics community. It is prescreened and highly selective. It describes the scope, size, and organization of the resources so that efficient choices can be made amongst many sites which may appear similar. A resource is excluded if it provides information primarily of interest to only one institution. Databases and resources focusing primarily on accelerator physics have been excluded in deference to the excellent compilation at the World Wide Web Virtual Library of Beam Physics and Accelerator Technology. My thanks to Betty Armstrong, Particle Data Group, the SLAC Library staff, and the many particle physics Web site and database maintainers who have all given me their generous assistance. Please send comments and

430

Bimodal and multimodal plant biomass particle mixtures  

DOE Patents (OSTI)

An industrial feedstock of plant biomass particles having fibers aligned in a grain, wherein the particles are individually characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L, wherein the L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers, the W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers, and the L.times.W dimensions define a pair of substantially parallel top and bottom surfaces, and wherein the particles in the feedstock are collectively characterized by having a bimodal or multimodal size distribution.

Dooley, James H.

2013-07-09T23:59:59.000Z

431

Predict particle collection in spray towers  

SciTech Connect

Spray tower wet scrubbers are used for control of particulates (as well as gaseous pollutants). The author has found that in cocurrent spray scrubbers, the most important parameter in determining particle collection efficiency is inlet dust particle size, followed by (in decreasing order of importance) gas velocity, collector droplet size, liquid-to-gas ratio, and length of scrubber. In countercurrent scrubbers, the most important parameters are collector droplet size, liquid-to-gas ratio, length of scrubber, and gas velocity. Note that some of these factors are directly related to collection, and some are related indirectly. This article provides equations, based on theoretical considerations and empirical data, for predicting particle collection efficiencies. The parameter ranges covered are typical of those encountered in the practical operation of conventional spray towers that use a ``cool`` (or cooled) inlet gas stream, so the equations are applicable to many industrial spray tower systems. The results are limited based on the ranges of the parameters evaluated, and while it may be possible to extrapolate beyond that, this has not been verified. (The initial model was for a flue-gas desulfurization system at a large power station that requires both particulate removal and SO{sub 2} absorption.)

Hesketh, H.E. [Southern Illinois Univ., Carbondale, IL (United States)

1995-10-01T23:59:59.000Z

432

Review of Particle Physics  

SciTech Connect

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2158 new measurements from 551 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on neutrino mass, mixing, and oscillations, QCD, top quark, CKM quark-mixing matrix, V{sub ud} and V{sub us}, V{sub cb} and V{sub ub}, fragmentation functions, particle detectors for accelerator and non-accelerator physics, magnetic monopoles, cosmological parameters, and big bang cosmology. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

Particle Data Group; Nakamura, Kenzo; al., et

2010-06-30T23:59:59.000Z

433

Development of a particle monitor for the CFFF  

DOE Green Energy (OSTI)

To evaluate and improve the performance of particulate control devices (dry electrostatic precipitator or DESP, wet electrostatic precipitator or WESP, Baghouse or BH), the entering particle loading, and size distribution if measurable, is needed. Standard extraction methods provide this data but we labor intensive and thus can not provide this data on-line in near-real-time as needed to determine best particulate device settings for changing operating conditions. Furthermore, the extreme particle number density of the solids in the process stream (10{sup 7} particles/cm{sup 3}) and the small particle sizes (mass mean diameter 0.5--1.0 {mu}m) are outside the capability of existing near-real-time particle loading and sizing devices. Thus, a particulate sample extraction and dilution system (SEDS) was constructed to allow on-line, near continuous determination of solid particulate size distribution with loading in the flue gas entering the particulate cleanup systems. The US Department of Energy Coal Fired Flow Facility (CFFF) SEDS was modeled on a Southern Research Institute developed system which dilutes the sampled flue gas to reduce moisture content, acid mist content, temperature and particulate loading as needed to allow direct, near continuous measurement using commercially available instrumentation. Because the 0.25--1.5 {mu}m particles which present the greatest difficulty for successful cleaning by an electrostatic precipitator are difficult to charge and are produced in large numbers by the high temperature MHD combustion, the CFFF SEDS was designed to measure primarily this size particles. In addition to the measurement uncertainties of the commercially obtained and calibrated particle counting instrument in the SEDS, the dilution process introduces other uncertainties. These uncertainties are being evaluated as the SEDS construction is being completed and as best operating parameters are being determined.

Parker, J.L.; Giel, T.V.; Winkleman, B.C.; Hodges, M.E.; Holt, J.K.; Douglas, J.R.

1993-06-01T23:59:59.000Z

434

Open Problems in $?$ Particle Condensation  

E-Print Network (OSTI)

$\\alpha$ particle condensation is a novel state in nuclear systems. We briefly review the present status on the study of $\\alpha$ particle condensation and address the open problems in this research field: $\\alpha$ particle condensation in heavier systems other than the Hoyle state, linear chain and $\\alpha$ particle rings, Hoyle-analogue states with extra neutrons, $\\alpha$ particle condensation related to astrophysics, etc.

Y. Funaki; M. Girod; H. Horiuchi; G. Roepke; P. Schuck; A. Tohsaki; T. Yamada

2010-03-05T23:59:59.000Z

435

The Particle Adventure | How do we experiment with tiny particles...  

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

Accelerators and particle detectors - How do we experiment with tiny particles? - Fixed target experiments In a fixed-target experiment, a charged particle such as an electron or a...

436

Diffusion Dynamics of Charged Dust Particles in Capacitively Coupled RF Discharge System  

SciTech Connect

Dusty plasma is loosely defined as electron-ion plasma with additional charged components of micron-sized dust particles. In this study, we developed a particle diagnostic technique based on light scattering and particle tracking velocimetry to investigate the dynamics of micron-sized titanium oxide particles in Argon gas capacitively coupled rf-discharge. The particle trajectories are constructed from sequence of image frames and treated as sample paths of charged Brownian motion. At specific sets of plasma parameters, disordered liquid-like dust particle configuration are observed. Mean-square-displacement of the particle trajectories are determined to characterize the transport dynamics. We showed that the dust particles in disordered liquid phase exhibit anomalous diffusion with different scaling exponents for short and large time scales, indicating the presence of slow and fast modes which can be related to caging effect and dispersive transport, respectively.

Chew, W. X.; Muniandy, S. V.; Wong, C. S.; Yap, S. L.; Tan, K. S. [Plasma Research Laboratory, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

437

Numerical modeling of a solid particle solar central receiver  

Science Conference Proceedings (OSTI)

The flow of air and particles and the heat transfer inside a solar heated, open cavity containing a falling cloud of 100 to 1000 micron solid particles have been studied. Two-way momentum and thermal coupling between the particles and the air is included in the analysis along with the effects of radiative transport within the particle cloud, among the cavity surfaces, and between the cloud and the surfaces. The flow field is assumed to be two dimensional with steady mean quantities. The PSI-Cell (particle source in cell) computer code is used to describe the gas-particle interaction. The method of discrete ordinates is used to obtain the radiative transfer within the cloud. The results include the velocity and temperature profiles of the particles and the air. In addition, the thermal performance of the solid particle solar receiver has been determined as a function of the following particle parameters: size, mass flow rate, absorptivity, and infrared scattering albedo. Other parameters which have been varied include the incident solar flux (both magnitude and distribution) and receiver size. A forced flow, applied across the cavity aperture, has also been investigated as a means of decreasing convective heat loss from the cavity. Comparison of the results from the model has been made with an experiment performed at the radiant heat facility in Albuquerque. The model has also been used to predict the entrainment of air and the decrease in particle drag which has been observed when measurements were made of particle velocity in a cloud of particles in free fall.

Evans, G.H.; Houf, W.G.; Greif, R.; Crowe, C.

1985-12-01T23:59:59.000Z

438

ARM - Measurement - Hydrometeor Size Distribution  

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

Size Distribution Size Distribution ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor Size Distribution The number of hydrometeors observed in a given size range. Categories Cloud Properties, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments LDIS : Laser Disdrometer Datastreams LDIS : Laser Disdrometer Datastreams PARS2 : OTT Parsivel2 Laser Disdrometer VDIS : Video Disdrometer Datastreams VDIS : Video Disdrometer Drop Size Distribution

439

Experimental and analytical research on the aerodynamics of wind turbines. Mid-term technical report, June 1--December 31, 1975  

SciTech Connect

The successful development of reliable, cost competitive horizontal axis, propeller-type wind energy conversion systems (WECS) is strongly dependent on the availability of advanced technology for each of the system components. Past experience and current studies of this type of wind energy conversion systems have shown that the wind turbine subsystem most significantly effects the system's cost effectiveness and performance capability. Thus adequate technology bases are essential for all elements of the wind turbine design. Information is presented concerning aerodynamic design and performance technology, wind turbine parametric performance study, selection of model wind turbine configurations, and structural design of wind turbine models.

Rohrbach, C.

1976-02-01T23:59:59.000Z

440

Experimental and analytical research on the aerodynamics of wind turbines. Mid-term technical report, June 1--December 31, 1975  

DOE Green Energy (OSTI)

The successful development of reliable, cost competitive horizontal axis, propeller-type wind energy conversion systems (WECS) is strongly dependent on the availability of advanced technology for each of the system components. Past experience and current studies of this type of wind energy conversion systems have shown that the wind turbine subsystem most significantly effects the system's cost effectiveness and performance capability. Thus adequate technology bases are essential for all elements of the wind turbine design. Information is presented concerning aerodynamic design and performance technology, wind turbine parametric performance study, selection of model wind turbine configurations, and structural design of wind turbine models.

Rohrbach, C.

1976-02-01T23:59:59.000Z

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441

The Particle Adventure | How do we experiment with tiny particles...  

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

experiment with tiny particles? - A linear or circular accelerator? All accelerators are either linear or circular, the difference being whether the particle is shot like a bullet...

442

The Particle Adventure | How do we experiment with tiny particles...  

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

Accelerators and particle detectors - How do we experiment with tiny particles? - Major accelerators We invite you to explore the basic plans of the world's major accelerators so...

443

The Particle Adventure | How do we experiment with tiny particles...  

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

Accelerators Accelerators solve two problems for physicists. First, since all particles behave like waves, physicists use accelerators to increase a particle's momentum, thus...

444

The Particle Adventure  

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

Shortcomings Shortcomings of the first data Shortcomings of the first data The data were convincing but not perfect, and there were significant shortcomings. For one thing, by July 4, 2012, there weren't enough statistics to measure whether the rate at which this particle (the Higgs boson) decays to various collections of less massive particles (the "branching ratios") are those predicted by the Standard Model. A "branching ratio" is simply the probability that a particle will decay via a given decay channel. These ratios are predicted by the Standard Model, and measured by observing the same particle decay over and over again. The next plot shows the best measurements we can make of the branching ratios with the data available in 2013. Since these are the ratios to the

445

Particle Physics Experiment  

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

What Is A Particle Physics Experiment? The word "experiment" often makes people envision a scientist in white lab coat and goggles walking into the lab, pouring some test tubes...

446

Particles and Prairies: Credits  

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

Particles and Prairies Video Sponsors: Funding for this program was provided in part by the U.S. Department of Energy Office of Energy Research, Illinois State Board of Education's...

447

Nuclear & Particle Physics Directorate  

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

Nuclear & Particle Physics Program Advisory Committee Meeting 21-22 June 2010 Agenda Submitted Proposals STAR Beam Use Proposal PHENIX Beam Use Proposal LoI: Feasibility Test of...

448

Nuclear & Particle Physics Directorate  

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

Draft Agenda Brookhaven Nuclear and Particle Physics Program Advisory Committee Meeting 6-8 June 2011 Reference Documents PAC Recommendations, 21-22 June 2010 Charge to PAC for...

449

The Particle Adventure  

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

How Do Fundamental Particles Get Mass? > How Does the Higgs Boson... How Does the Higgs Boson get its Mass? On the other hand, if a rumor crosses the room,... ...it creates the...

450

The Particle Adventure  

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

The Higgs Boson and Beyond > Is this Higgs Boson the Higgs Boson... Is this Higgs Boson the Higgs Boson of the Standard Model? We do know that the particle we discovered is a Higgs...

451

The Particle Adventure  

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

Boson Finding the Mass of the Higgs Boson How do you find the mass of the Higgs Boson when it decays into other particles before we detect it? If you were going to build a bicycle,...

452

Heterogeneous particle swarm optimizers  

Science Conference Proceedings (OSTI)

Particle swarm optimization (PSO) is a swarm intelligence technique originally inspired by models of flocking and of social influence that assumed homogeneous individuals. During its evolution to become a practical optimization tool, some heterogeneous ...

Marco A. Montes De Oca; Jorge Peña; Thomas Stützle; Carlo Pinciroli; Marco Dorigo

2009-05-01T23:59:59.000Z

453

Particle entrapping filamentry structures  

DOE Patents (OSTI)

Minute particulates are removed from a fluid flow by directing the fluid towards a particle entrapping element having a hair-like covering a flexible filaments. The filaments have fixed root ends and movable free ends that extend away from the roots and are shiftable in response to flow pressure and particle impacts. Particles lodge within the mass of filaments while the fluid component of the flow passes through particle entrapping element if the substrate is porous or is deflected away if the substrate is impervious. The structure does not necessarily cause a sizable pressure drop in the flow and can entrap large quantities of particulates. The invention has a variety of specific applications such as, for example, removal of smoke from the exhaust gases of vehicle engines or stationary fuel consuming installations. 11 figs.

Steele, W.A.; Leider, H.R.; Mohr, P.B.

1988-09-29T23:59:59.000Z

454

Particle Data Group - Downloads  

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

2 web edition of RPP for different platforms 2012 book edition of RPP Particle Physics Booklet (rpp-2012-booklet.pdf file, 7 MBytes); Review of Partilce Physics 1526 pages, Phys....

455

Particle Data Group - Downloads  

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

1 web edition of RPP for different platforms 2010 book edition of RPP Particle Physics Booklet (rpp-2010-booklet.pdf file, 6 MBytes); rpp-2010-JPhys-G-37-075021.pdf file (40...

456

Particle Data Group  

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

2 book, booklet will be available in August. Web edition of the Review of Particle Physics is now available. Funded By: US DOE US NSF CERN MEXT (Japan) INFN (Italy) MEC (Spain)...

457

Particle Data Group - Downloads  

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

6 MBytes); rpp-2010-JPhys-G-37-075021.pdf file (40 MBytes) of the published RPP 2010 book; Figures from the reviews in RPP The PDG Monte Carlo