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


1

ARM - Measurement - Aerosol absorption  

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

absorption absorption 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 absorption The process in which radiation energy is retained by aerosols. 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 IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) PSAP : Particle Soot Absorption Photometer PASS : Photoacoustic Soot Spectrometer External Instruments OMI : Ozone Monitoring Instrument

2

A New Method for Measuring Aerosol Absorption  

Science Conference Proceedings (OSTI)

A new technique has recently been developed to measure aerosol absorption by means of a microdensitometer. Black particulate material is collected into six spots on membrane filters by a laboratory-tested impaction/concentration technique. Follow-...

B. B. Murphey; S. I. Reynolds

1988-08-01T23:59:59.000Z

3

Method and apparatus for aerosol particle absorption spectroscopy  

DOE Patents (OSTI)

A method and apparatus for determining the absorption spectra, and other properties, of aerosol particles. A heating beam source provides a beam of electromagnetic energy which is scanned through the region of the spectrum which is of interest. Particles exposed to the heating beam which have absorption bands within the band width of the heating beam absorb energy from the beam. The particles are also illuminated by light of a wave length such that the light is scattered by the particles. The absorption spectra of the particles can thus be determined from an analysis of the scattered light since the absorption of energy by the particles will affect the way the light is scattered. Preferably the heating beam is modulated to simplify the analysis of the scattered light. In one embodiment the heating beam is intensity modulated so that the scattered light will also be intensity modulated when the particles absorb energy. In another embodiment the heating beam passes through an interferometer and the scattered light reflects the Fourier Transform of the absorption spectra.

Campillo, Anthony J. (Nesconset, NY); Lin, Horn-Bond (Manorville, NY)

1983-11-15T23:59:59.000Z

4

Evidence that the spectral dependence of light absorption by aerosols is  

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

Evidence that the spectral dependence of light absorption by aerosols is Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon Title Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon Publication Type Journal Article LBNL Report Number LBNL-55056 Year of Publication 2004 Authors Kirchstetter, Thomas W., Tihomir Novakov, and Peter V. Hobbs Journal Journal of Geophysical Research: Atmospheres Volume 109 Issue D21 Keywords aerosol light absorption, biomass burning, organic carbon Abstract The wavelength dependence of light absorption by aerosols collected on filters is investigated throughout the near-ultraviolet to near-infrared spectral region. Measurements were made using an optical transmission method. Aerosols produced by biomass combustion, including wood and savanna burning, and by motor vehicles, including diesel trucks, are included in the analysis. These aerosol types were distinguished by different wavelength (λ) dependences in light absorption. Light absorption by the motor vehicle aerosols exhibited relatively weak wavelength dependence; absorption varied approximately as λ-1, indicating that black carbon (BC) was the dominant absorbing aerosol component. By contrast, the biomass smoke aerosols had much stronger wavelength dependence, approximately λ-2. The stronger spectral dependence was the result of enhanced light absorption at wavelengths shorter than 600 nm and was largely reduced when much of the sample organic carbon (OC) was extracted by dissolution in acetone. This indicates that OC in addition to BC in the biomass smoke aerosols contributed significantly to measured light absorption in the ultraviolet and visible spectral regions and that OC in biomass burning aerosols may appreciably absorb solar radiation. Estimated absorption efficiencies and imaginary refractive indices are presented for the OC extracted from biomass burning samples and the BC in motor vehicle-dominated aerosol samples. The uncertainty of these constants is discussed. Overall, results of this investigation show that low-temperature, incomplete combustion processes, including biomass burning, can produce light-absorbing aerosols that exhibit much stronger spectral dependence than high-temperature combustion processes, such as diesel combustion.

5

Influence of Absorbing Aerosols on the Inference of Solar Surface Radiation Budget and Cloud Absorption  

Science Conference Proceedings (OSTI)

This study addresses the impact of absorbing aerosols on the retrieval of the solar surface radiation budget (SSRB) and on the inference of cloud absorption using multiple global datasets. The data pertain to the radiation budgets at the top of ...

Zhanqing Li

1998-01-01T23:59:59.000Z

6

Absorption of Visible Radiation by Atmospheric Aerosol Particles Fog and Cloud Water Residues  

Science Conference Proceedings (OSTI)

Light absorption by samples of atmospheric aerosol particles as a function of size was studied using the integrating sphere method. In addition, the optical properties of fog and cloud-water residues were determined. The samples were taken at two ...

Karl Andre; Ralph Dlugi; Gottfried Schnatz

1981-01-01T23:59:59.000Z

7

The impact of biogenic carbon emissions on aerosol absorption inMexico City  

Science Conference Proceedings (OSTI)

In order to determine the wavelength dependence of atmospheric aerosol absorption in the Mexico City area, the absorption angstrom exponents (AAEs) were calculated from aerosol absorption measurements at seven wavelengths obtained with a seven-channel aethalometer during two field campaigns, the Mexico City Metropolitan Area study in April 2003 (MCMA 2003) and the Megacity Initiative: Local and Global Research Observations in March 2006 (MILAGRO). The AAEs varied from 0.76 to 1.56 in 2003 and from 0.54 to 1.52 in 2006. The AAE values determined in the afternoon were consistently higher than the corresponding morning values, suggesting the photochemical formation of absorbing secondary organic aerosols (SOA) in the afternoon. The AAE values were compared to stable and radiocarbon isotopic measurements of aerosol samples collected at the same time to determine the sources of the aerosol carbon. The fraction of modern carbon (fM) in the aerosol samples, as determined from {sup 14}C analysis, showed that 70% of the carbonaceous aerosols in Mexico City were from modern sources, indicating a significant impact from biomass burning during both field campaigns. The {sup 13}C/{sup 12}C ratios of the aerosol samples illustrate the significant impact of Yucatan forest fires (C-3 plants) in 2003 and local grass fires (C-4 plants) at site T1 in 2006. A direct comparison of the fM values, stable carbon isotope ratios, and calculated aerosol AAEs suggested that the wavelength dependence of the aerosol absorption was controlled by the biogenically derived aerosol components.

Marley, N; Gaffney, J; Tackett, M J; Sturchio, N; Hearty, L; Martinez, N; Hardy, K D; Machany-Rivera, A; Guilderson, T P; MacMillan, A; Steelman, K

2009-02-24T23:59:59.000Z

8

Investigations of the Absorption Properties of Near-Ground Aerosol by the Methods of Optical-Acoustic Spectrometry and Diff...  

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

Investigations of the Absorption Properties of Investigations of the Absorption Properties of Near-Ground Aerosol by the Methods of Optical-Acoustic Spectrometry and Diffuse Extinction V. S. Kozlov, M. V. Panchenko, A. B. Tikhomirov, and B. A. Tikhomirov Institute of Atmospheric Optics Tomsk, Russia Introduction Aerosol absorption is an important factor in the formation of non-selective radiation extinction in the visible wavelength range, and plays a great role in solving many radiative and climatic problems. The principal absorbing substance in atmospheric aerosol is soot (crystal carbon), which strongly affects the atmospheric transparency, albedo of clouds, and snow cover. The non-selective absorption by finely dispersed soot aerosol is considered to be one of the most plausible reasons for the appearance of

9

Another Look at the Influence of Absorbing Aerosols in Drops on Cloud Absorption: Large Aerosols  

Science Conference Proceedings (OSTI)

Since as early as 1969, solar absorbing aerosols inside of cloud drops have been suggested to influence cloud radiative properties. The absorbing aerosols were invoked to help explain two anomalies: 1) the maximum visible albedo of thick ...

Carynelisa Erlick; Dana Schlesinger

2008-02-01T23:59:59.000Z

10

Wavelength Dependence of the Absorption of Black Carbon Particles: Predictions and Results from the TARFOX Experiment and Implications for the Aerosol Single Scattering Albedo  

Science Conference Proceedings (OSTI)

Measurements are presented of the wavelength dependence of the aerosol absorption coefficient taken during the Tropical Aerosol Radiative Forcing Observational Experiment (TARFOX) over the northern Atlantic. The data show an approximate ??1 ...

Robert W. Bergstrom; Philip B. Russell; Phillip Hignett

2002-02-01T23:59:59.000Z

11

Root Absorption  

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

Root Absorption Root Absorption Name: Carolyn Location: N/A Country: N/A Date: N/A Question: MY Neice is doing a science fair project on plants. More specifically she needs to know if you water your flowering plants with colored water, does the flower change colors and if so, why? Replies: Dear Carolyn, Dyeing flowers works best on cut stems in water: http://youth.net/nsrc/sci/sci032.html#anchor598182 Title: The Effect Of Color On The Speed Of Dyeing Flowers Some rooted plants can change flower color by altering the soil pH: http://www.cahe.nmsu.edu/pubs/yard/1996/120996.html Sincerely, Anthony R. Brach This sounds like a good question for a science project. I think she should do the project first and get some data and then try to answer the question herself. If she can't figure it out, then she should look for some help.

12

Iron Absorption  

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

Iron Absorption Iron Absorption Name: Mary Location: N/A Country: N/A Date: N/A Question: I wrote before to Steve and got a answer back. I would like more information. The cirmcustances were that I first had anaemia and then I went for a gastroscopy. The results of which were I had insufficient acid been produced in the stomach. I was told that acid was nessary for the absorbion of iron and it was because of this that I became anaemic. I was told to eat plently of red meat not too many vegetables. Is there any other information you can give me? Replies: It is very difficult to say for sure without seeing you chart and I am not your doctor. But it sounds to me like you are deficient in the vitamin B12. In your stomach you have 3 basic types of cells. One is called chief cells which secrete the precursor of the enzyme pepsin which begins the breakdown of protein. Another is called the parietal cells which secrete your stomach acid and a substance called intrinsic factor. Now-switch to your bone marrow which is where your red blood cells are made. In order for your red blood cells to mature in the bone marrow, vitamin B12 is necessary. B12 can only be obtained from animal food sources such as meat, milk and eggs. Unfortunately, B12 cannot be absorbed in the stomach without intrinsic factor. If there is sufficient B12 present in the diet, it can be stored in the liver. If you aren't eating enough animal sources your B12 will be taken from your liver until you run out. You could also be deficient in intrinsic factor. So while the outcome is anemia (not enough red blood cells) the problem could be from a few different things. Follow your doctor's recommendations and eat more sources of B12

13

X-RAY ABSORPTION SPECTROSCOPY FOR THE CHEMICAL CHARACTERIZATION OF ATMOSPHERIC AEROSOLS  

E-Print Network (OSTI)

CHARACTERIZATION OF ATMOSPHERIC AEROSOLS J. M. Jaklevic andOF ATMOSPHERIC AEROSOLS X~RAY J. M. Jaklevic and A. C.from the atmospheric aerosol. Modern air sampling technology

Jaklevic, J. M.

2011-01-01T23:59:59.000Z

14

Reduction in biomass burning aerosol light absorption upon humidification: Roles of inorganically-induced hygroscopicity, particle collapse, and photoacoustic heat and mass transfer  

Science Conference Proceedings (OSTI)

Smoke particle emissions from the combustion of biomass fuels typical for the western and southeastern United States were studied and compared under high humidity and ambient conditions in the laboratory. The fuels used are Montana ponderosa pine (Pinus ponderosa), southern California chamise (Adenostoma fasciculatum), and Florida saw palmetto (Serenoa repens). Information on the non-refractory chemical composition of biomass burning aerosol from each fuel was obtained with an aerosol mass spectrometer and through estimation of the black carbon concentration from light absorption measurements at 870 nm. Changes in the optical and physical particle properties under high humidity conditions were observed for hygroscopic smoke particles containing substantial inorganic mass fractions that were emitted from combustion of chamise and palmetto fuels. Light scattering cross sections increased under high humidity for these particles, consistent with the hygroscopic growth measured for 100 nm particles in HTDMA measurements. Photoacoustic measurements of aerosol light absorption coefficients reveal a 20% reduction with increasing relative humidity, contrary to the expectation of light absorption enhancement by the liquid coating taken up by hygroscopic particles. This reduction is hypothesized to arise from two mechanisms: 1. Shielding of inner monomers after particle consolidation or collapse with water uptake; 2. The contribution of mass transfer through evaporation and condensation at high relative humidity to the usual heat transfer pathway for energy release by laser heated particles in the photoacoustic measurement of aerosol light absorption. The mass transfer contribution is used to evaluate the fraction of aerosol surface covered with liquid water solution as a function of RH.

lewis, Kristen A.; Arnott, W. P.; Moosmuller, H.; Chakrabarti, Raj; Carrico, Christian M.; Kreidenweis, Sonia M.; Day, Derek E.; Malm, William C.; Laskin, Alexander; Jimenez, Jose L.; Ulbrich, Ingrid M.; Huffman, John A.; Onasch, Timothy B.; Trimborn, Achim; Liu, Li; Mishchenko, M.

2009-11-27T23:59:59.000Z

15

Variability of Absorption and Optical Properties of Key Aerosol Types Observed in Worldwide Locations  

Science Conference Proceedings (OSTI)

Aerosol radiative forcing is a critical, though variable and uncertain, component of the global climate. Yet climate models rely on sparse information of the aerosol optical properties. In situ measurements, though important in many respects, ...

Oleg Dubovik; Brent Holben; Thomas F. Eck; Alexander Smirnov; Yoram J. Kaufman; Michael D. King; Didier Tanr; Ilya Slutsker

2002-02-01T23:59:59.000Z

16

Energy Basics: Absorption Cooling  

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

cooling. Other potential heat sources include propane, solar-heated water, or geothermal-heated water. Although mainly used in industrial or commercial settings, absorption...

17

Solar absorption surface panel  

DOE Patents (OSTI)

A composite metal of aluminum and nickel is used to form an economical solar absorption surface for a collector plate wherein an intermetallic compound of the aluminum and nickel provides a surface morphology with high absorptance and relatively low infrared emittance along with good durability.

Santala, Teuvo J. (Attleboro, MA)

1978-01-01T23:59:59.000Z

18

Absorption heat pump system  

DOE Patents (OSTI)

The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Grossman, Gershon (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

19

Absorption heat pump system  

DOE Patents (OSTI)

The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Grossman, G.

1982-06-16T23:59:59.000Z

20

Solar selective absorption coatings  

DOE Patents (OSTI)

A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

Mahoney, Alan R. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Martinez, F. Edward (Horseheads, NY)

2004-08-31T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Solar selective absorption coatings  

DOE Patents (OSTI)

A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

Mahoney, Alan R. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Martinez, F. Edward (Horseheads, NY)

2003-10-14T23:59:59.000Z

22

Optical absorption measurement system  

DOE Patents (OSTI)

The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.

Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.

1986-09-17T23:59:59.000Z

23

Optical absorption measurement system  

DOE Patents (OSTI)

The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.

Draggoo, Vaughn G. (Livermore, CA); Morton, Richard G. (San Diego, CA); Sawicki, Richard H. (Pleasanton, CA); Bissinger, Horst D. (Livermore, CA)

1989-01-01T23:59:59.000Z

24

Seven-effect absorption refrigeration  

DOE Patents (OSTI)

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

DeVault, Robert C. (Knoxville, TN); Biermann, Wendell J. (Fayetteville, NY)

1989-01-01T23:59:59.000Z

25

Seven-effect absorption refrigeration  

DOE Patents (OSTI)

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

DeVault, R.C.; Biermann, W.J.

1989-05-09T23:59:59.000Z

26

Absorption heat pump system  

DOE Patents (OSTI)

An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)

1984-01-01T23:59:59.000Z

27

The Quantum Absorption Refrigerator  

E-Print Network (OSTI)

A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power J_c vanishes as J_c proportional to T_c^{alpha}, when T_c approach 0, where alpha =d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath.

Amikam Levy; Ronnie Kosloff

2011-09-04T23:59:59.000Z

28

Ultraviolet absorption hygrometer  

DOE Patents (OSTI)

An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined.

Gersh, Michael E. (Bedford, MA); Bien, Fritz (Concord, MA); Bernstein, Lawrence S. (Bedford, MA)

1986-01-01T23:59:59.000Z

29

Absorption Heat Pump Water Heater  

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

Absorption Heat Pump Water Heater Absorption Heat Pump Water Heater Kyle Gluesenkamp Building Equipment Group, ETSD gluesenkampk@ornl.gov 865-241-2952 April 3, 2013 CRADA - GE Development of High Performance Residential Gas Water Heater Image courtesy John Wilkes 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: Absorption technology could greatly boost water heater efficiency, but faces barriers of high first cost and working fluid challenges. Impact of Project: Energy factor of gas storage water

30

Absorption Heat Pump Water Heater  

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

Absorption Heat Pump Water Heater Absorption Heat Pump Water Heater Kyle Gluesenkamp Building Equipment Group, ETSD gluesenkampk@ornl.gov 865-241-2952 April 3, 2013 CRADA - GE Development of High Performance Residential Gas Water Heater Image courtesy John Wilkes 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: Absorption technology could greatly boost water heater efficiency, but faces barriers of high first cost and working fluid challenges. Impact of Project: Energy factor of gas storage water

31

Energy Basics: Absorption Heat Pumps  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...

32

X-ray Absorption Spectroscopy  

SciTech Connect

This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

Yano, Junko; Yachandra, Vittal K.

2009-07-09T23:59:59.000Z

33

The role of solar absorption in climate and climate change  

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

role of solar absorption in climate and role of solar absorption in climate and climate change William Collins UC Berkeley and Lawrence Berkeley Lab with Andrew Conley, David Fillmore, and Phil Rasch National Center for Atmospheric Research Boulder, Colorado, USA 2 Prior Research on Absorption and Climate Field Experiments: * Central Equatorial Pacific Experiment * Indian Ocean Experiment Modeling studies of clouds: * The color of the planet * Climate with enhanced cloud absorption Synthesis of models and aerosol observations: * Development of aerosol assimilation * Application to aerosol/climate interactions 3 Natural and anthropogenic aerosols India, March 2000 California, October 2003 Africa, March 2003 4 Historical and projected sulfate emissions * Emissions from India have tripled in last 20 years of 20 th century..

34

Retrieval of Aerosol Scattering and Absorption Properties from Photopolarimetric Observations over the Ocean during the CLAMS Experiment  

Science Conference Proceedings (OSTI)

The extensive set of measurements performed during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment provides a unique opportunity to evaluate aerosol retrievals over the ocean from multiangle, multispectral ...

Jacek Chowdhary; Brian Cairns; Michael I. Mishchenko; Peter V. Hobbs; Glenn F. Cota; Jens Redemann; Ken Rutledge; Brent N. Holben; Ed Russell

2005-04-01T23:59:59.000Z

35

Energy Basics: Absorption Heat Pumps  

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

but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat...

36

Compact Absorption Chiller - Energy Innovation Portal  

The Compact Absorption Chiller uses microchannel technologies in an absorption heat pump which produces cooling using heat as the primary energy source.

37

NETL: Pressure Swing Absorption Device  

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

Pressure Swing Absorption Device and Process for Separating CO2 from Shifted Syngas and its Capture for Subsequent Storage Pressure Swing Absorption Device and Process for Separating CO2 from Shifted Syngas and its Capture for Subsequent Storage Project No.: DE-FE0001323 New Jersey Institute of Technology is developing an advanced pressure swing absorption-based (PSAB) device via laboratory-based experiments. The device will be used to accomplish a cyclic process to process low temperature post-shift-reactor synthesis gas resulting from the gasification process into purified hydrogen at high pressure for use by the combustion turbine of an integrated gasification combined cycle (IGCC) plant. The overall goal of the proposed work is to develop an advanced PSAB device and cyclic process for use in a coal-fired IGCC plant to produce purified hydrogen at high pressure and a highly purified CO2 stream suitable for use or sequestration.

38

Absorption-heat-pump system  

DOE Patents (OSTI)

An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Grossman, G.; Perez-Blanco, H.

1983-06-16T23:59:59.000Z

39

Oxygen Absorption in Cooling Flows  

E-Print Network (OSTI)

The inhomogeneous cooling flow scenario predicts the existence of large quantities of gas in massive elliptical galaxies, groups, and clusters that have cooled and dropped out of the flow. Using spatially resolved, deprojected X-ray spectra from the ROSAT PSPC we have detected strong absorption over energies ~0.4-0.8 keV intrinsic to the central ~1 arcmin of the galaxy, NGC 1399, the group, NGC 5044, and the cluster, A1795. These systems have amongst the largest nearby cooling flows in their respective classes and low Galactic columns. Since no excess absorption is indicated for energies below ~0.4 keV the most reasonable model for the absorber is warm, collisionally ionized gas with T=10^{5-6} K where ionized states of oxygen provide most of the absorption. Attributing the absorption only to ionized gas reconciles the large columns of cold H and He inferred from Einstein and ASCA with the lack of such columns inferred from ROSAT, and also is consistent with the negligible atomic and molecular H inferred from HI, and CO observations of cooling flows. The prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified by Chandra, XMM, and ASTRO-E.

David A. Buote

2000-01-19T23:59:59.000Z

40

Absorption Heat Pump Basics | Department of Energy  

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

Absorption Heat Pump Basics Absorption Heat Pump Basics Absorption Heat Pump Basics August 19, 2013 - 11:11am Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption coolers available that work on the same principal, but are not reversible and cannot serve as a heat source. These are also called gas-fired coolers. How Absorption Heat Pumps Work Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Absorption Heat Pumps | Department of Energy  

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

Absorption Heat Pumps Absorption Heat Pumps Absorption Heat Pumps June 24, 2012 - 2:11pm Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption (or gas-fired) coolers available that work on the same principle. Unlike some absorption heat pumps, however, these are not reversible and cannot serve as a heat source. Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its

42

Absorption Heat Pumps | Department of Energy  

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

Absorption Heat Pumps Absorption Heat Pumps Absorption Heat Pumps June 24, 2012 - 2:11pm Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption (or gas-fired) coolers available that work on the same principle. Unlike some absorption heat pumps, however, these are not reversible and cannot serve as a heat source. Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its

43

Photodetector with enhanced light absorption  

DOE Patents (OSTI)

A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

Kane, James (Lawrenceville, NJ)

1985-01-01T23:59:59.000Z

44

Purge needs in absorption chillers  

Science Conference Proceedings (OSTI)

Absorption chillers are regaining a significant share of large tonnage chiller sales, such as they had 20 years ago. Gas-fired chillers are now available that have a base energy (ultimate fuel usage) consumption rate per ton comparable to that in electric units. Effective purging in an absorption chiller is an absolute necessity to achieve the low chilled water temperature needed for dehumidification and to fully benefit from the energy savings offered by double-effect cycles. Although the purge system is usually not shown on the typical cycle schematic, its proper functioning is a key requirement for satisfactory machine operation. This article discusses the effect of noncondensible (N/C) gases on the absorption cooling process and the basics of purge systems. In addition, the article discusses the rationale for the important design step of selecting the location of the N/C probe, and discusses purge systems applicable to the direct-fired, double-effect machines now entering the marketplace.

Murray, J.G. (Battelle, Columbus, OH (United States))

1993-10-01T23:59:59.000Z

45

Localized light absorption by nanoscale semiconducting tips ...  

Science Conference Proceedings (OSTI)

Page 1. Localized light absorption ... constructive interference between transmitted light and internal reflections at resonant radii Page 14. ...

2013-04-03T23:59:59.000Z

46

Advanced regenerative absorption refrigeration cycles  

DOE Patents (OSTI)

Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

Dao, Kim (14 Nace Ave., Piedmont, CA 94611)

1990-01-01T23:59:59.000Z

47

Save by absorption heat pumping  

SciTech Connect

The author compares absorption heat pumping (AHP) to mechanical vapor compressor (MVC) heat pumping. The moving part of the AHP is a pump easy to maintain and inexpensive to spare. The mechanical component of the MVC is a vapor compressor which requires more maintenance and is cost-prohibitive to spare. Also, in the MVC system, a purified product stream is heat pumped in an open compressor, thus risking product contamination. In the AHP system, the cold and hot utilities are heat pumped. Therefore, product integrity with an AHP system is well protected as in a conventional fractionation column.

Davidson, W.F.; Campagne, W.V.L.

1987-12-01T23:59:59.000Z

48

Backscatter absorption gas imaging system  

DOE Patents (OSTI)

A video imaging system for detecting hazardous gas leaks. Visual displays of invisible gas clouds are produced by radiation augmentation of the field of view of an imaging device by radiation corresponding to an absorption line of the gas to be detected. The field of view of an imager is irradiated by a laser. The imager receives both backscattered laser light and background radiation. When a detectable gas is present, the backscattered laser light is highly attenuated, producing a region of contrast or shadow on the image. A flying spot imaging system is utilized to synchronously irradiate and scan the area to lower laser power requirements. The imager signal is processed to produce a video display.

McRae, Jr., Thomas G. (Livermore, CA)

1985-01-01T23:59:59.000Z

49

Quantum-enhanced absorption refrigerators  

E-Print Network (OSTI)

Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators.

Luis A. Correa; Jos P. Palao; Daniel Alonso; Gerardo Adesso

2013-08-19T23:59:59.000Z

50

Absorption Cooling Basics | Department of Energy  

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

Cooling Basics Cooling Basics Absorption Cooling Basics August 16, 2013 - 2:26pm Addthis Absorption coolers use heat rather than electricity as their energy source. Because natural gas is the most common heat source for absorption cooling, it is also referred to as gas-fired cooling. Other potential heat sources include propane, solar-heated water, or geothermal-heated water. Although mainly used in industrial or commercial settings, absorption coolers are commercially available for large residential homes. How Absorption Cooling Works An absorption cooling cycle relies on three basic principles: When a liquid is heated it boils (vaporizes) and when a gas is cooled it condenses Lowering the pressure above a liquid reduces its boiling point Heat flows from warmer to cooler surfaces.

51

Computation of X-Ray Absorption  

Science Conference Proceedings (OSTI)

... of the absorption at other energies, assuming they ... and at DoE's National Energy Research Scientific ... With the improved efficiency of FeffMPI now in ...

2011-01-21T23:59:59.000Z

52

Absorption Chillers and Heat Pumps - Technology, Applications...  

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

applications. The last decade saw intensive research and development efforts of gas-fired absorption systems for both heating and cooling applications in the USA, Europe and Japan....

53

Evaluation of Mg for Local Energy Absorption  

Science Conference Proceedings (OSTI)

The AZ31 material exhibited the best energy absorption performance, .... Effects of Alloying Elements and Cooling Rate on Morphology of Phases in CaO Added

54

Solar selective absorption coatings - Energy Innovation Portal  

A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron ...

55

A Fast Line-by-Line Method for Atmospheric Absorption Computations: The Automatized Atmospheric Absorption Atlas  

Science Conference Proceedings (OSTI)

A computationally fast line-by-line method for the determination of atmospheric absorption is described. This method is based on the creation of an Automatized Atmospheric Absorption Atlas (4A) covering all possible plausible atmospheric ...

N. A. Scott; A. Chedin

1981-07-01T23:59:59.000Z

56

Atmospheric Precorrected Differential Absorption technique to retrieve columnar water vapor  

Science Conference Proceedings (OSTI)

Differential absorption techniques are suitable to retrieve the total column water vapor contents from imaging spectroscopy data. A technique called Atmospheric Precorrected Differential Absorption (APDA) is derived directly from simplified radiative transfer equations. It combines a partial atmospheric correction with a differential absorption technique. The atmospheric path radiance term is iteratively corrected during the retrieval of water vapor. This improves the results especially over low background albedos. The error of the method for various ground reflectance spectra is below 7% for most of the spectra. The channel combinations for two test cases are then defined, using a quantitative procedure, which is based on MODTRAN simulations and the image itself. An error analysis indicates that the influence of aerosols and channel calibration is minimal. The APDA technique is then applied to two AVIRIS images acquired in 1991 and 1995. The accuracy of the measured water vapor columns is within a range of {+-}5% compared to ground truth radiosonde data.

Schlaepfer, D.; Itten, K.I. [Univ. of Zuerich (Switzerland). Dept. of Geography] [Univ. of Zuerich (Switzerland). Dept. of Geography; Borel, C.C. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Keller, J. [Paul Scherrer Inst., Villigen (Switzerland)] [Paul Scherrer Inst., Villigen (Switzerland)

1998-09-01T23:59:59.000Z

57

Cavity-enhanced absorption for optical refrigeration  

E-Print Network (OSTI)

A 20-fold increase over the single path optical absorption is demonstrated with a low loss medium placed in a resonant cavity. This has been applied to laser cooling of Yb:ZBLAN glass resulting in 90% absorption of the incident pump light. A coupled-cavity scheme to achieve active optical impedance matching is analyzed.

Seletskiy, Denis V; Sheik-Bahae, Mansoor

2009-01-01T23:59:59.000Z

58

Absorption chillers: Technology for the future  

SciTech Connect

In an era of heightened awareness of energy efficiency and the associated environmental impacts, many industries worldwide are exploring ``environmentally friendly`` technologies that provide equivalent or improved performance while reducing or eliminating harmful side-effects. The refrigeration and air-conditioning industry, due to its reliance on CFCs and HCFCs, has invested in research in alternatives to the industry standard vapor compression machines. One alternative technology with great promise is chemical absorption. Absorption chillers offer comparable refrigeration output with reduced SO{sub 2}, CO{sub 2}, and NO{sub x} emissions. Absorption chillers do not use CFCs or HCFCs, refrigerants that contribute to ozone depletion and global warming. Additionally, gas-fired absorption chillers can save significant amounts in energy costs when used in combination with a vapor compression chiller in a hybrid system. The hybrid system can take advantage of the comparatively low price of natural gas (per unit ton) and rely on the high performance of vapor compression when electricity prices are lower. The purpose of this article is to provide an introduction for those new to absorption technology as well as a discussion of selected high efficiency cycles, a discussion on the technology of coupling absorption with vapor compression systems to form a hybrid system, and the environmental impacts of absorption.

Garland, P.W. [Oak Ridge National Lab., TN (United States); Garland, R.W. [Dept. of Energy, Washington, DC (United States)

1997-12-31T23:59:59.000Z

59

Variable effect desorber-resorber absorption cycle  

DOE Patents (OSTI)

An absorption refrigeration system has an intermediate temperature desorber-resorber pair. A valve between the desorber-resorber pair is modulated to control the capacity for load matching.

Biermann, Wendell J. (Fayetteville, NY)

1985-01-01T23:59:59.000Z

60

Conceptual design of an advanced absorption cycle: the double-effect regenerative absorption refrigeration cycle  

DOE Green Energy (OSTI)

An advanced absorption refrigeration cycle was proposed as a heat-activated refrigeration system. Referred to as the double-effect regenerative absorption cycle of cycle 2R, it improves the performance of the conventional single-effect absorption cycle at high heat source temperatures. The performance of cycle 2R continually improves as input temperatures rise, in contrast to the conventional double-effect absorption cycle that has a sharp cut-off temperature below which it ceases to operate. Cycle 2R operates with two subcycles, the first-effect and the second-effect subcycles.

Dao, K.

1978-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Solar absorption aqua-ammonia absorption system simulation base on climate of Malaysia  

Science Conference Proceedings (OSTI)

Solar energy is one of the most well known green sources of energy. This research presents a feasibility study of evacuated solar thermal collector by aqua-ammonia ejector absorption systems as a small scale air conditioning unit. The modeling has been ... Keywords: ejector, evacuated tubes, solar assisted absorption system

Poorya Ooshaksaraei; Sohif Mat; M. Yahya; Ahmad Mahir Razali; Azami Zaharim; K. Sopian

2010-01-01T23:59:59.000Z

62

Posters Long-Pathlength Infrared Absorption Measurements  

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

3 3 Posters Long-Pathlength Infrared Absorption Measurements in the 8- to 14-µm Atmospheric Window: Self-Broadening Coefficient Data T. J. Kulp (a) and J. Shinn Geophysics and Environmental Research Program Lawrence Livermore National Laboratory Livermore, California Introduction The accurate characterization of the latent infrared (IR) absorption in the atmospheric window regions continues to be an area of research interest for the global climate modeling community. In the window between 8 and 14 µm, this absorption can be attributed primarily to water vapor. It consists of 1) weak lines originating from the edge of the water vapor pure rotational band (at low wavenumbers) and the trailing P-branch of the υ 2 rovibrational band (at the high-wavenumber boundary of the window); and 2) the

63

Energy Saving with Absorption Refrigeration Technologies  

E-Print Network (OSTI)

Absorption refrigeration technology can be an economical and cost effective means of reducing energy cost and/or improving the efficiency and output of your process. We believe the potential benefits of absorption refrigeration technology have generally been overlooked by the process industry. This paper will address the application of the lithium bromide-water cycle in various energy saving modes. A waste heat powered absorption chiller producing chilled water can reduce energy consumption in a process plant by replacing an existing mechanical refrigeration system or replacing cooling tower water with a lower temperature cooling medium at negligible increase in energy cost. A variety of waste heat sources can be used at temperatures as low as 150 F.

Davis, R. C.

1984-01-01T23:59:59.000Z

64

Enhanced absorption cycle computer model. Final report  

DOE Green Energy (OSTI)

Absorption heat pumps have received renewed and increasing attention in the past two decades. The rising cost of electricity has made the particular features of this heat-powered cycle attractive for both residential and industrial applications. Solar-powered absorption chillers, gas-fired domestic heat pumps, and waste-heat-powered industrial temperatures boosters are a few of the applications recently subjected to intensive research and development. The absorption heat pump research community has begun to search for both advanced cycles in various multistage configurations and new working fluid combinations with potential for enhanced performance and reliability. The development of working absorptions systems has created a need for reliable and effective system simulations. A computer code has been developed for simulation of absorption systems at steady state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system`s components and property subroutines containing thermodynamic properties of the working fluids. The user conveys to the computer an image of his cycle by specifying the different subunits and their interconnections. Based on this information, the program calculates the temperature, flow rate, concentration, pressure, and vapor fraction at each state point in the system, and the heat duty at each unit, from which the coefficient of performance (COP) may be determined. This report describes the code and its operation, including improvements introduced into the present version. Simulation results are described for LiBr-H{sub 2}O triple-effect cycles, LiCl-H{sub 2}O solar-powered open absorption cycles, and NH{sub 3}-H{sub 2}O single-effect and generator-absorber heat exchange cycles. An appendix contains the User`s Manual.

Grossman, G.; Wilk, M. [Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering

1993-09-01T23:59:59.000Z

65

Potassium emission absorption system. Topical report 12  

DOE Green Energy (OSTI)

The Potassium Emission Absorption System is one of the advanced optical diagnostics developed at Mississippi State University to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the upstream of an MHD flow, the system directly measures gas temperature and neutral potassium atom number density through spectroscopic emission absorption techniques. From these measurements the electron density can be inferred from a statistical equilibrium calculation and the electron conductivity in the MHD channel found by use of an electron mobility model. The instrument has been utilized for field test measurements on MHD facilities for almost a decade and has been proven to provide useful measurements as designed for MHD nozzle, channel, and diffuser test sections. The theory of the measurements, a system description, its capabilities, and field test measurement results are reported here. During the development and application of the instrument several technical issues arose which when addressed advanced the state of the art in emission absorption measurement. Studies of these issues are also reported here and include: two-wavelength measurements for particle-laden flows, potassium D-line far wing absorption coefficient, bias in emission absorption measurements arising from dirty windows and misalignments, non-coincident multiwavelength emission absorption sampling errors, and lineshape fitting for boundary layer flow profile information. Although developed for NLHD application, the instrument could be applied to any high temperature flow with a resonance line in the 300 to 800 nm range, for instance other types of flames, rocket plumes or low temperature plasmas.

Bauman, L.E.

1995-04-01T23:59:59.000Z

66

Absorption Cooling Optimizes Thermal Design for Cogeneration  

E-Print Network (OSTI)

Contrary to popular concept, in most cases, thermal energy is the real VALUE in cogeneration and not the electricity. The proper consideration of the thermal demands is equal to or more important than the electrical demands. High efficiency two-stage absorption chillers of the type used at Rice University Cogen Plant offer the most attractive utilization of recoverable thermal energy. With a coefficient of performance (COP) up to 1.25, the two-stage, parallel flow absorption chiller can offer over fifty (50) percent more useful thermal energy from the same waste heat source--gas turbine exhaust, I.C. engine exhaust and jacketwater, incinerator exhaust, or steam turbine extraction.

Hufford, P. E.

1986-01-01T23:59:59.000Z

67

Laser isotope separation by multiple photon absorption  

DOE Patents (OSTI)

Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, in the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO.sub.2 laser light may be used to highly enrich .sup.34 S in natural SF.sub.6 and .sup.11 B in natural BCl.sub.3.

Robinson, C. Paul (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Lyman, John L. (Los Alamos, NM); Aldridge, III, Jack P. (Los Alamos, NM)

1977-01-01T23:59:59.000Z

68

Laser isotope separation by multiple photon absorption  

DOE Patents (OSTI)

Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO.sub.2 laser light may be used to highly enrich .sup.34 S in natural SF.sub.6 and .sup.11 B in natural BCl.sub.3.

Robinson, C. Paul (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Lyman, John L. (Los Alamos, NM); Aldridge, III, Jack P. (Los Alamos, NM)

1987-01-01T23:59:59.000Z

69

Survey of absorption cooling technology in solar applications  

DOE Green Energy (OSTI)

A comprehensive survey of the current state of the absorption cooling technology has been conducted. This survey discusses the basic and applied absorption cooling/heating technology, analyses the current state of the art including the discussion of limitations and possible solutions, identifies areas where promising developments are indicated, lists the current products and activities of the absorption industry, and presents the current RD and D efforts of the U.S. government. The main subjects covered in the survey are as follows: Principles of absorption cooling technology (NH/sub 3/-H/sub 2/O cycle and H/sub 2/O-LiBr Cycle), Adaptation of absorption cooling technology for solar cooling applications, Thermal performance of absorption cooling units, Comparison of NH/sub 3/-H/sub 2/O absorption with H/sub 2/O-LiBr absorption, Commercially available solar absorption units, General trends of the absorption cooling industry toward solar application, Absorption cooling system performance in actual installations, Limitations of absorption cooling technology, Solar-powered absorption heat pumps, and U.S. ERDA activities relating to solar absorption cooling. The treatment of the subjects is intended to be basic and comprehensive in order that the general readers may understand the current aspects of absorption technology in solar cooling applications. 36 references.

Auh, P C

1977-07-01T23:59:59.000Z

70

A New Absorption Cycle: The Single-Effect Regenerative Absoprtion Refrigeration Cycle  

E-Print Network (OSTI)

REGENERATIVE ABSORPTION REFRIGERATION CYCLE ABSTRACT A new absorption cycle , using heat as the energy

Dao, K.

2011-01-01T23:59:59.000Z

71

ABSORPTION HEAT PUMP IN THE DISTRICT HEATING  

E-Print Network (OSTI)

#12;ABSORPTION HEAT PUMP IN THE DISTRICT HEATING PLANT Dr.sc.ing. Agnese Lickrastina M.Sc. Normunds European Heat Pump Summit 2013, Nuremberg, 15-16.10.2013 · Riga District Heating company · Operation #12;JSC RGAS SILTUMS · the biggest District Heating company in Latvia and in the Baltic states

Oak Ridge National Laboratory

72

Absorption of solar radiation by solar neutrinos  

E-Print Network (OSTI)

We calculate the absorption probability of photons radiated from the surface of the Sun by a left-handed neutrino with definite mass and a typical momentum for which we choose |p_1|=0.2 MeV, producing a heavier right-handed antineutrino. Considering two transitions the \

G. Duplancic; P. Minkowski; J. Trampetic

2003-04-16T23:59:59.000Z

73

Corrosion inhibitor for aqueous ammonia absorption system  

DOE Patents (OSTI)

A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

Phillips, Benjamin A. (Benton Harbor, MI); Whitlow, Eugene P. (St. Joseph, MI)

1998-09-22T23:59:59.000Z

74

Corrosion inhibitor for aqueous ammonia absorption system  

DOE Patents (OSTI)

A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

Phillips, B.A.; Whitlow, E.P.

1998-09-22T23:59:59.000Z

75

Absorption machine with desorber-resorber  

DOE Patents (OSTI)

An absorption refrigeration system utilizing a low temperature desorber and intermediate temperature resorber. The system operates at three temperatures and three pressures to increase the efficiency of the system and is capable of utilizing a lower generator temperature than previously used.

Biermann, Wendell J. (Fayetteville, NY)

1985-01-01T23:59:59.000Z

76

Coupled dual loop absorption heat pump  

DOE Patents (OSTI)

A coupled dual loop absorption system which utilizes two separate complete loops. Each individual loop operates at three temperatures and two pressures. This low temperature loop absorber and condenser are thermally coupled to the high temperature loop evaporator, and the high temperature loop condenser and absorber are thermally coupled to the low temperature generator.

Sarkisian, Paul H. (Watertown, MA); Reimann, Robert C. (Lafayette, NY); Biermann, Wendell J. (Fayetteville, NY)

1985-01-01T23:59:59.000Z

77

Laser light absorption with density profile modifications  

SciTech Connect

Two-dimensional computer simulations studied plasma heating by electron plasma waves. The results emphasize the importance of nonlinear steepening of the density profile near the critical density. A typical simulation result is presented in order to illustrate these profile modifications. It is shown that large dc magnetic field generation is an inherent property of the absorption of obliquely-incident light. (MOW)

Kruer, W.; Valeo, E.; Estabrook, K.; Langdon, B.; Lasinski, B.

1974-12-01T23:59:59.000Z

78

Overview-absorption/Rankine solar cooling program  

DOE Green Energy (OSTI)

The tasks being performed in the absorption and Rankine program areas run the gamut from basic work on fluids to development of chillers and chiller components, to field and reliability testing of complete cooling systems. In the absorption program, there are six current and five essentially completed projects. In the Rankine program, there are five current projects directly supported by DOE, and three projects funded through and managed by NASA/MSFC (Manned Space Flight Center, Huntsville, Alabama). The basic features of these projects are discussed. The systems under development in five of these current projects have been selected for field testing in the new SOLERAS program, a joint US-Saudi Arabian enterprise. Some technical highlights of the program are presented.

Wahlig, M.; Heitz, A.; Boyce, B.

1980-03-01T23:59:59.000Z

79

Integrated vacuum absorption steam cycle gas separation  

Science Conference Proceedings (OSTI)

Methods and systems for separating a targeted gas from a gas stream emitted from a power plant. The gas stream is brought into contact with an absorption solution to preferentially absorb the targeted gas to be separated from the gas stream so that an absorbed gas is present within the absorption solution. This provides a gas-rich solution, which is introduced into a stripper. Low pressure exhaust steam from a low pressure steam turbine of the power plant is injected into the stripper with the gas-rich solution. The absorbed gas from the gas-rich solution is stripped in the stripper using the injected low pressure steam to provide a gas stream containing the targeted gas. The stripper is at or near vacuum. Water vapor in a gas stream from the stripper is condensed in a condenser operating at a pressure lower than the stripper to concentrate the targeted gas. Condensed water is separated from the concentrated targeted gas.

Chen, Shiaguo (Champaign, IL); Lu, Yonggi (Urbana, IL); Rostam-Abadi, Massoud (Champaign, IL)

2011-11-22T23:59:59.000Z

80

SIMULATION OF A SOLAR ABSORPTION COOLING SYSTEM  

E-Print Network (OSTI)

This paper describes the dynamic modeling of a solar absorption cooling plant that will be built for both research and demonstration purposes by the end of 2007. The synchronizing of cooling loads with solar radiation intensity is an important advantage when utilizing solar energy in air conditioning in buildings. The first part of this work deals with the dynamic modeling of an evacuated tube collector. A field of these collectors feed a single-effect absorption chiller of 35 kW nominal cooling capacity. The simulation model has been done in a modular way under TRNSYS16. In a second part, simulation and optimization of the system has been investigated in order to determine the effect of several parameters (collector area, tank volume...) on chiller performance.

J. P. Praene; D. Morau; F. Lucas; F. Garde; H. Boyer; J. P. Praene

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

TENDER ENERGY X-RAY ABSORPTION  

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

TENDER ENERGY X-RAY ABSORPTION TENDER ENERGY X-RAY ABSORPTION SPECTROSCOPY (TES) Project Team: S. Bare 1,2 , J. Brandes 3 , T. Buonassisi 4 , J. Chen 5,2 , M. Croft 6 , E. DiMasi 7 , A. Frenkel 8,2 , D. Hesterberg 9 , S. Hulbert 7,2 , S. Khalid 7 , S. Myneni 10 , P. Northrup 7,11 , E.T. Rasbury 11 , B. Ravel 12 , R. Reeder 11 , J. Rodriguez 7,2 , D. Sparks 5,13 , V. Stojanoff 7 , G. Waychunas 14 1 UOP LLC, 2 Synchrotron Catalysis Consortium, 3 Skidaway Inst. of Oceanography, 4 MIT Laboratory for Photovoltaics Research, 5 Univ. of Delaware, 6 Rutgers Univ., 7 Brookhaven National Lab, 8 Yeshiva Univ., 9 North Carolina State Univ., 10 Princeton Univ., 11 Stony Brook Univ., 12 NIST, 13 Delaware Environmental Inst., 14 Lawrence Berkeley National Lab TECHNIQUES: High performance and in-situ X-ray absorption spectroscopy and spatially-resolved XAS of

82

Triple effect absorption chiller utilizing two refrigeration circuits  

Science Conference Proceedings (OSTI)

This patent describes a heat absorption method for an absorption chiller. It comprises: providing a firs absorption system circuit for operation within a first temperature range, providing a second absorption system circuit for operation within a second temperature range; heat exchanging refrigerant and absorber solution; thermal communication with an external heat load. This patent describes a heat absorption apparatus for use as an absorption chiller. It includes: a first absorption system circuit for operation within a first temperature range; a second absorption system circuit for operation within a second temperature range which has a lower maximum temperature relative to the first temperature range; the first circuit having generator means, condenser means, evaporator means, and absorber means operatively connected together; the second circuit having generator means condenser means, evaporator means, and absorber means operative connected together; and the first circuit condenser means and the first circuit absorber means being in heat exchange communication with the second circuit generator means.

DeVault, R.C.

1988-03-22T23:59:59.000Z

83

Ultrabroadband light absorption by a sawtooth anisotropic metamaterial slab  

E-Print Network (OSTI)

We present an ultrabroadband thin-film infrared absorber made of sawtoothed anisotropic metamaterial. Absorptivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption ...

Cui, Yanxia

84

Solar Radiation Absorption due to Water Vapor: Advanced Broadband Parameterizations  

Science Conference Proceedings (OSTI)

Accurate parameterizations for calculating solar radiation absorption in the atmospheric column due to water vapor lines and continuum are proposed for use in broadband shortwave radiative transfer codes. The error in the absorption values is ...

Tatiana A. Tarasova; Boris A. Fomin

2000-11-01T23:59:59.000Z

85

Development of laser absorption sensors for combustion gases.  

E-Print Network (OSTI)

??In situ sensors based on laser absorption spectroscopy are developed to monitor key species in combustion exhaust gases. Direct absorption (DA) and wavelength-modulation-spectroscopy (WMS) strategies (more)

Chao, Xing.

2012-01-01T23:59:59.000Z

86

Enhanced light absorption of solar cells and photodetectors by ...  

Enhanced light absorption of solar cells and photodetectors by diffraction is described. Triangular, rectangular, and blazed subwavelength periodic structures are ...

87

Gas Powered Air Conditioning Absorption vs. Engine-Drive  

E-Print Network (OSTI)

It used to be that the only alternative to costly electric air conditioning was the double-effect gas-fired absorption chiller/heaters. Beginning in the 1980's, they were the "star" equipment promoted by gas companies throughout the nation. Although not a new technology at the time, neither was the gas engine. But now in the 19901s, gas engine-drive (GED) chillers have "hit" the air conditioning market with a "bang". In the Lone Star Gas Company area in 1995, GED chillers are now being considered in as many projects as are Absorption. units. Where once the only studies being analyzed were absorption vs. electric chiller operation costs. Now, the choice is: Why, Where, and How to choose between gas fired Absorption and GED chillers. WHY Absorption or Engine ? . Absorption uses the most environmentally friendly refrigerant - water. . Absorption chillers are chiller/heaters Absorption chillers are manufactured by the four US major manufacturers Absorption chillers have few moving parts . Engine chillers provide "free" hot water Engine chillers retrofit with DX systems . Engine chillers use less gas per ton WHERE Do Absorption And Engine Chillers Belong? . Absorption: Office buildings, restaurants, industries, churches, universities . Engine: Hospitals, universities, hotels, apartments, industries HOW To Choose Between Absorption And Engine Chillers? Energy cost Operation and maintenance costs Equipment cost Environmental concerns Thermal requirements . Space requirements Staff experience

Phillips, J. N.

1996-01-01T23:59:59.000Z

88

Split-flow regeneration in absorptive air separation  

DOE Patents (OSTI)

A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs. 4 figs.

Weimer, R.F.

1987-11-24T23:59:59.000Z

89

Distributed Bragg Reflectors With Reduced Optical Absorption  

DOE Patents (OSTI)

A new class of distributed Bragg reflectors has been developed. These distributed Bragg reflectors comprise interlayers positioned between sets of high-index and low-index quarter-wave plates. The presence of these interlayers is to reduce photon absorption resulting from spatially indirect photon-assisted electronic transitions between the high-index and low-index quarter wave plates. The distributed Bragg reflectors have applications for use in vertical-cavity surface-emitting lasers for use at 1.55 .mu.m and at other wavelengths of interest.

Klem, John F. (Albuquerque, NM)

2005-08-16T23:59:59.000Z

90

Dilution cycle control for an absorption refrigeration system  

DOE Patents (OSTI)

A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.

Reimann, Robert C. (Lafayette, NY)

1984-01-01T23:59:59.000Z

91

500F Absorption Heat Pump Under Development  

E-Print Network (OSTI)

Economic industrial heat pumping to temperatures above 500F (260C) is promised in the near future. A new absorption fluid is the key. Tested under DOE sponsorship, the new fluid has proven to be thermally stable and noncorrosive to austenitic stainless steel up to 500F, or mild steel up to 430F. Heat transfer properties are comparable to those of the conventional LiBr-H20 system. Paired with water as the working fluid, laboratory tests have shown that useful temperature lifts of over 162F (90C) ?T can be achieved allowing 10F heat exchangers. The fluid is nontoxic and noncombustible. Good economics for the system should stem from (1) high temperature capabilities for wider and more highly valued uses, (2) high internal temperature lifts for low heat exchanger surface areas, (3) predominantly carbon steel components, and (4) better COP in the heat amplifier mode than current absorption heat pumps. Recent laboratory results are presented including temperature applicability maps.

Davidson, W. F.; Erickson, D. C.

1986-06-01T23:59:59.000Z

92

Residential solar-absorption chiller thermal dynamics  

DOE Green Energy (OSTI)

Research is reported on the transient performance of a commercial residential 3 ton lithium bromide-water absorption chiller designed for solar firing. Emphasis was placed on separating the chiller response from that of the entire test facility so that its transient response could solely be observed and quantified. It was found that the entire system time response and thermal capacitance has a major impact on performance degradation due to transient operation. Tests run to ascertain computer algorithms which simulate system isolated chiller performance, revealed processes hitherto undocumented. Transient operation is simulated by three distinct algorithms associated with the three phases of chiller operation. The first phase is start up time. It was revealed during testing that the time required to reach steady state performance values, when the chiller was turned on, was a linear function of steady state water supply temperatures. The second phase is quasi steady state performance. Test facility's performance compared favorably with the manufacturer's published data. The third phase is the extra capacity produced during spin down. Spin down occurs when the hot water supply pump is turned off while the other system pumps remain operating for a few minutes, thus allowing extra chiller capacity to be realized. The computer algorithms were used to generate plots which show the operational surface of an isolated absorption chiller subjected to off design and transient operation.

Guertin, J.M.; Wood, B.D.; McNeill, B.W.

1981-03-01T23:59:59.000Z

93

Solar absorption cooling plant in Seville  

SciTech Connect

A solar/gas cooling plant at the Engineering School of Seville (Spain) was tested during the period 2008-2009. The system is composed of a double-effect LiBr + water absorption chiller of 174 kW nominal cooling capacity, powered by: (1) a pressurized hot water flow delivered by mean of a 352 m{sup 2} solar field of a linear concentrating Fresnel collector and (2) a direct-fired natural gas burner. The objective of the project is to indentify design improvements for future plants and to serve as a guideline. We focused our attention on the solar collector size and dirtiness, climatology, piping heat losses, operation control and coupling between solar collector and chiller. The daily average Fresnel collector efficiency was 0.35 with a maximum of 0.4. The absorption chiller operated with a daily average coefficient of performance of 1.1-1.25, where the solar energy represented the 75% of generator's total heat input, and the solar cooling ratio (quotient between useful cooling and insolation incident on the solar field) was 0.44. (author)

Bermejo, Pablo; Pino, Francisco Javier; Rosa, Felipe [Departamento de Ingenieria Energetica, Universidad de Sevilla, Camino de los Descubrimiento s/n, 41092 Sevilla (Spain)

2010-08-15T23:59:59.000Z

94

Absorptive Recycle of Distillation Waste Heat  

E-Print Network (OSTI)

When the heat source available to a distillation process is at a significantly higher temperature than the reboiler temperature, there is unused availability (ability to perform work) in the heat supplied to the reboiler. Similarly, if the reflux condenser operates above ambient temperature, the rejected heat also contains unused availability. By incorporating an absorption heat pump (AHP) into the distillation process, these sources of unused availability can be tapped so as to recycle (and hence, conserve) up to 50% of the required distillation energy. In contrast to compressor driven heat pumps, this savings is accomplished without need for a separate substantial input of mechanical power. A different AHP configuration is used depending on whether the excess availability is in the source heat or reject heat. In the excessive source temperature case, the higher temperature source heat is applied to the AHP, which then supplies the total reboiler requirement and recycles half the reject heat, with the remainder being rejected conventionally. In the excessive reject temperature case, all the reject heat is supplied to a reverse absorption heat pump (HAHP) which recycles half to reboiler temperature while reducing the remainder to ambient temperature.

Erickson, D. C.; Lutz, E. J., Jr.

1982-01-01T23:59:59.000Z

95

Performance bound for quantum absorption refrigerators  

E-Print Network (OSTI)

An implementation of quantum absorption chillers with three qubits has been recently proposed, that is ideally able to reach the Carnot performance regime. Here we study the working efficiency of such self-contained refrigerators, adopting a consistent treatment of dissipation effects. We demonstrate that the coefficient of performance at maximum cooling power is upper bounded by 3/4 of the Carnot performance. The result is independent of the details of the system and the equilibrium temperatures of the external baths. We provide design prescriptions that saturate the bound in the limit of a large difference between the operating temperatures. Our study suggests that delocalized dissipation, which must be taken into account for a proper modelling of the machine-baths interaction, is a fundamental source of irreversibility which prevents the refrigerator from approaching the Carnot performance arbitrarily closely in practice. The potential role of quantum correlations in the operation of these machines is also investigated.

Luis A. Correa; Jos P. Palao; Gerardo Adesso; Daniel Alonso

2012-12-18T23:59:59.000Z

96

Spray generators for absorption refrigeration systems  

DOE Patents (OSTI)

A spray generator for an absorption refrigeration system that includes a heat exchanger comprised of a multiplicity of variably spaced heat exchange tubes. The tubes are spaced close together near the top of the heat exchanger and spaced more widely apart near the bottom of the heat exchanger. Dilute absorbent solution is sprayed down through the heat exchanger. The close nesting of the tubes in the top portion of the heat exchanger retards liquid flow and aids heating of the solution. The wide spacing of the tubes in the lower section of the heat exchanger facilitate vapor flow out of the heat exchanger and eliminates liquid "blow-off". The top tubes are covered by a baffle to prevent the liquid solution from splashing out of the heat exchanger off of these top tubes.

Sibley, Howard W. (Baldwinsville, NY)

1979-06-19T23:59:59.000Z

97

Gas separation using ultrasound and light absorption  

SciTech Connect

An apparatus and method for separating a chosen gas from a mixture of gases having no moving parts and utilizing no chemical processing is described. The separation of particulates from fluid carriers thereof has been observed using ultrasound. In a similar manner, molecular species may be separated from carrier species. It is also known that light-induced drift may separate light-absorbing species from carrier species. Therefore, the combination of temporally pulsed absorption of light with ultrasonic concentration is expected to significantly increase the efficiency of separation by ultrasonic concentration alone. Additionally, breaking the spatial symmetry of a cylindrical acoustic concentrator decreases the spatial distribution of the concentrated particles, and increases the concentration efficiency.

Sinha, Dipen N. (Los Alamos, NM)

2012-07-31T23:59:59.000Z

98

Carbon Dioxide Capture by Absorption with Potassium Carbonate  

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

Carbon Dioxide Capture by Absorption Carbon Dioxide Capture by Absorption with Potassium Carbonate Background Although alkanolamine solvents, such as monoethanolamine (MEA), and solvent blends have been developed as commercially-viable options for the absorption of carbon dioxide (CO 2 ) from waste gases, natural gas, and hydrogen streams, further process improvements are required to cost-effectively capture CO 2 from power plant flue gas. The promotion of potassium carbonate (K

99

The role of solar absorption in climate and climate change  

E-Print Network (OSTI)

1 The role of solar absorption in climate and climate change William Collins UC Berkeley alter the radiative energy budget of the climate. · We will focus on solar reflection, absorption.43 -0.84 CO2 0.31 0.04 -0.31 (CH4) 0.22 0.40 -0.53 Change in Shortwave Absorption (2000-1860) Solar CH4

100

Ultrabroad-Band, Greatly Enhanced Light Absorption by Monolayer Graphene  

E-Print Network (OSTI)

We demonstrate greatly enhanced light absorption by monolayer graphene over a broad spectral range, from visible to near infrared, based on the attenuated total reflection. In the experiment, graphene is sandwiched between two dielectric media referred as superstrate and substrate. Based on numerical calculation and experimental results, the closer the refractive indices of the superstrate and the substrate, the higher the absorption of graphene will be. The light absorption of monolayer graphene up to 42.7% is experimentally achieved.

Zhao, Wangshi; Lu, Zhaolin

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Overview on absorption cooling technology in solar applications  

DOE Green Energy (OSTI)

The following topics are reviewed briefly: chiller performance, commercial availability, system performance, internal energy storage, water-cooling limitation, COP limitation, absorption heat pump, and DOE activities. (MHR)

Auh, P.C.

1978-01-01T23:59:59.000Z

102

Numerical simulation of microwave absorption of regenerative heat ...  

Science Conference Proceedings (OSTI)

The regenerative heat exchanger has a good absorption when the mullite refractory .... Point Alloys and Refractory Compounds with Its Own Chemical Energy.

103

Geothermal: Sponsored by OSTI -- Chapter 13. Absorption Refrigeration  

Office of Scientific and Technical Information (OSTI)

GEOTHERMAL TECHNOLOGIES LEGACY COLLECTION - Sponsored by OSTI -- Chapter 13. Absorption Refrigeration Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us |...

104

Energy Saving Absorption Heat Pump Water Heater - Energy ...  

ORNLs new absorption heat pump and water heater technology offers substantial energy savings and can reduce the use of fossil fuels by buildings. While ...

105

Fast magnetosonic wave propagation and absorption in Tokamaks  

DOE Green Energy (OSTI)

Fast magnetostatic wave propagation and absorption in a tokamak model consisting of an axially symmetric cylindrical plasma column with a radially varying density profile is considered.

Phillips, C.K.; Perkins, F.W.; Hwang, D.Q.

1985-07-01T23:59:59.000Z

106

CO2 Capture from Flue Gas by Phase Transitional Absorption  

Science Conference Proceedings (OSTI)

A novel absorption process called Phase Transitional Absorption was invented. What is the Phase Transitional Absorption? Phase Transitional Absorption is a two or multi phase absorption system, CO{sub 2} rich phase and CO{sub 2} lean phase. During Absorption, CO{sub 2} is accumulated in CO{sub 2} rich phase. After separating the two phases, CO{sub 2} rich phase is forward to regeneration. After regeneration, the regenerated CO{sub 2} rich phase combines CO{sub 2} lean phase to form absorbent again to complete the cycle. The advantage for Phase Transitional Absorption is obvious, significantly saving on regeneration energy. Because CO{sub 2} lean phase was separated before regeneration, only CO{sub 2} rich phase was forward to regeneration. The absorption system we developed has the features of high absorption rate, high loading and working capacity, low corrosion, low regeneration heat, no toxic to environment, etc. The process evaluation shows that our process is able to save 80% energy cost by comparing with MEA process.

Liang Hu

2009-06-30T23:59:59.000Z

107

Compression Behavior and Energy Absorption of Aluminum Alloys ...  

Science Conference Proceedings (OSTI)

Presentation Title, Compression Behavior and Energy Absorption of ... Abstract Scope, The usage of advanced high strength steels and Aluminum Alloys as...

108

Optimization of Hierarchical Lattice Structures for Energy Absorption  

Science Conference Proceedings (OSTI)

... potential to outperform foams in many applications, including energy absorption. ... of Fe-C Alloy as a Function of Cooling Rate and Local Solidification Time.

109

Advanced Exergy Analysis for a Solar Double Stage Absorption Chiller.  

E-Print Network (OSTI)

??Solar driven absorption chiller technology as an alternative mechanism for cooling has been the focus of tremendous recent interest due to its potential advantages for (more)

Hu, Yang

2012-01-01T23:59:59.000Z

110

Platinum Group Metal Oxide Absorption Properties of Perovskite ...  

Science Conference Proceedings (OSTI)

In this study, the absorption properties of various perovskite-type oxide is .... Influence of Different Cooling Structure on Surface Crack of HSLA Steel Plate by

111

J-51: Effect of Phonon Emission and Absorption in Electron ...  

Science Conference Proceedings (OSTI)

We present investigation on effects of phonon emission/absorption in ... Energy Harvesting and Cooling with Flexible and Light-Weight Organic Nanocomposites.

112

Diffraction: Enhanced Light Absorption of Solar Cells and ...  

Sandia National Laboratories Diffraction: Enhanced Light Absorption of Solar Cells and Photodetectors HTTPS://IP.SANDIA.GOV Sandia National Laboratories is a multi ...

113

Solar absorption refrigeration system using new working fluid pairs  

Science Conference Proceedings (OSTI)

Absorption refrigeration systems powered by solar energy increasingly attract research interests in the last years. In this study, thermodynamic analyses for different working fluid pairs are performed. A computer simulation model has been developed ... Keywords: NH3-LiNO3, absorption, crystallization, generator, performance, refrigeration, solar energy

Jasim M. Abdulateef; Kamaruzzaman Sopian; M. A. Alghoul; Mohd Yusof Sulaiman; Azami Zaharim; Ibrahim Ahmad

2008-02-01T23:59:59.000Z

114

Onsite Wastewater Treatment Systems: Septic Tank/Soil Absorption Field  

E-Print Network (OSTI)

For septic tank and soil absorption systems to work properly, homeowners must choose the right kind of system for their household size and soil type, and they must maintain them regularly. This publication explains the treatment, design, operation, and maintenance of septic tank and soil absorption systems.

Lesikar, Bruce J.

2008-10-23T23:59:59.000Z

115

WEATHER MODIFICATION BY CARBON DUST ABSORPTION OF SOLAR ENERGY  

E-Print Network (OSTI)

"10 of Io absorbed by Ocean Fig. 1. Contrast of clear air tropical condition with normal solar absorption the surrounding air primarily ('" 94%) by direct solar energy absorption and rapid molecular conduction~ensive ground generators into the boundary layer. By warming the boundary layer air under proper conditions

Gray, William

116

Measurement of Absorption in Rooms with Sound Absorbing Ceilings  

Science Conference Proceedings (OSTI)

Serious difficulties have been encountered in attempts to measure the absorption coefficients of sound absorbing ceilings in large offices. An analysis of the sound field is made and it is concluded (1) that the reverberation time formula is usually invalid if the absorption is concentrated on one surface of the room

J. R. Power

1938-01-01T23:59:59.000Z

117

Triple effect absorption chiller utilizing two refrigeration circuits  

DOE Patents (OSTI)

A triple effect absorption method and apparatus having a high coefficient of performance. Two single effect absorption circuits are combined with heat exchange occurring between a condenser and absorber of a high temperature circuit, and a generator of a low temperature circuit. The evaporators of both the high and low temperature circuits provide cooling to an external heat load.

DeVault, Robert C. (Knoxville, TN)

1988-01-01T23:59:59.000Z

118

Molecular Line Absorption in a Scattering Atmosphere. Part I: Theory  

Science Conference Proceedings (OSTI)

This paper revisits the classical problem of particle scatteringgaseous absorption and considers the extent to which the growth of absorption lines of a known gas can be used to obtain information about the scattering particles. The focus of the ...

Graeme L. Stephens; Andrew Heidinger

2000-05-01T23:59:59.000Z

119

ESRF HIGHLIGHTS 2005 X-RAY ABSORPTION AND MAGNETIC SCATTERING  

E-Print Network (OSTI)

96 ESRF HIGHLIGHTS 2005 X-RAY ABSORPTION AND MAGNETIC SCATTERING References [1] C. Antoniak, J to original phenomena. These effects are observed in charge-density wave (CDW) materials. Upon cooling of the screw like dislocation shown in Figure 121b. #12;97 HIGHLIGHTS 2005 ESRF X-RAY ABSORPTION AND MAGNETIC

Paris-Sud 11, Université de

120

Permeation absorption sampler with multiple detection  

DOE Patents (OSTI)

A system for detecting analytes in air or aqueous systems includes a permeation absorption preconcentrator sampler for the analytes and analyte detectors. The preconcentrator has an inner fluid-permeable container into which a charge of analyte-sorbing liquid is intermittently injected, and a fluid-impermeable outer container. The sample is passed through the outer container and around the inner container for trapping and preconcentrating the analyte in the sorbing liquid. The analyte can be detected photometrically by injecting with the sorbing material a reagent which reacts with the analyte to produce a characteristic color or fluorescence which is detected by illuminating the contents of the inner container with a light source and measured the absorbed or emitted light, or by producing a characteristic chemiluminescence which can be detected by a suitable light sensor. The analyte can also be detected amperometrically. Multiple inner containers may be provided into which a plurality of sorbing liquids are respectively introduced for simultaneously detecting different analytes. baffling may be provided in the outer container. A calibration technique is disclosed. 9 figs.

Zaromb, S.

1989-03-30T23:59:59.000Z

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


121

Absorption media for irreversibly gettering thionyl chloride  

DOE Patents (OSTI)

Thionyl chloride is a hazardous and reactive chemical used as the liquid cathode in commercial primary batteries. Contrary to previous thinking, ASZM-TEDA.RTM. carbon (Calgon Corporation) reversibly absorbs thionyl chloride. Thus, several candidate materials were examined as irreversible getters for thionyl chloride. The capacity, rate and effect of temperature were also explored. A wide variety of likely materials were investigated through screening experiments focusing on the degree of heat generated by the reaction as well as the material absorption capacity and irreversibility, in order to help narrow the group of possible getter choices. More thorough, quantitative measurements were performed on promising materials. The best performing getter was a mixture of ZnO and ASZM-TEDA.RTM. carbon. In this example, the ZnO reacts with thionyl chloride to form ZnCl.sub.2 and SO.sub.2. The SO.sub.2 is then irreversibly gettered by ASZM-TEDA.RTM. carbon. This combination of ZnO and carbon has a high capacity, is irreversible and functions effectively above -20.degree. C.

Buffleben, George (Tracy, CA); Goods, Steven H. (Livermore, CA); Shepodd, Timothy (Livermore, CA); Wheeler, David R. (Albuquerque, NM); Whinnery, Jr., LeRoy (Danville, CA)

2002-01-01T23:59:59.000Z

122

The Effect of Gas Absorption on the Scattered Radiation in the Solar Almucantar: Results of Numerical Simulation  

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

Gas Absorption on the Gas Absorption on the Scattered Radiation in the Solar Almucantar: Results of Numerical Simulation T. Yu. Chesnokova, K. M. Firsov, I. M. Nasrtdinov, S. M. Sakerin, V. V. Veretennikov, and T. B. Zhuravleva Institute of Atmospheric Optics Tomsk, Russia Introduction The methods for reconstruction of the aerosol optical characteristics (e.g., aerosol size distribution, and single-scattering albedo) from diffuse and direct radiation measured in the solar almucantar has been widely used during the last decade. The photometers with filters in the "atmospheric transparency windows" in the wavelength range 0.4 to 1 m were applied for measurements. Usually it was assumed that one could neglect the molecular absorption of the measured diffuse radiation. Further development

123

Development of solar driven absorption air conditioners and heat pumps  

DOE Green Energy (OSTI)

The objective of this project is the development of absorption refrigeration systems for solar active heating and cooling applications. The approaches being investigated are those using air-cooled condenser-absorbers and those leading to coefficient of performances (COP) that increase continuously with heat source temperature. This is primarily an experimental project, with the emphasis on designing, fabricating and testing absorption chillers in operating regimes that are particularly suited for solar energy applications. The first phase of this project has been concluded and has experimentally demonstrated that the conventional single-effect ammonia-water absorption cycle can be used (with minor modifications) for solar cooling. The second phase of this project explores the commercial potential of the single-effect (SE) NH/sub 3//H/sub 2/O absorption air conditioner. (WHK)

Dao, K.; Wahlig, M.; Wali, E.; Rasson, J.; Molishever, E.

1980-03-01T23:59:59.000Z

124

Use Low-Grade Waste Steam to Power Absorption Chillers  

SciTech Connect

This revised ITP tip sheet on waste steam to power absorption chillers provides how-to advice for improving the system using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

125

Alteration of Atmospheric Solar Absorption by Clouds: Simulation and Observation  

Science Conference Proceedings (OSTI)

This study investigated theoretically and experimentally two parameters employed in recent attempts to address cloud absorption anomaly. One is the ratio, R, of shortwave cloud radiative forcing (CRF) at the surface to that at the top of the ...

Zhanqing Li; Louis Moreau

1996-05-01T23:59:59.000Z

126

Integrating giant microwave absorption with magnetic refrigeration in one  

E-Print Network (OSTI)

Integrating giant microwave absorption with magnetic refrigeration in one multifunctional with magnetic refrigeration in one multifunctional material. This integration not only advances our EMI problem, it is becoming very urgent to design and fabricate the electromagnetic compatibility (EMC

Wang, Wei Hua

127

Absorption of Solar Radiation by Atmospheric O4  

Science Conference Proceedings (OSTI)

Spectroscopic measurements of the atmospheric solar radiation attenuation reveal that the near ultravioletvisiblenear-infrared absorption of the oxygen collision complex (O2)2, thus far omitted from models, is important for the direct heating ...

Klaus Pfeilsticker; Frank Erle; Ulrich Platt

1997-04-01T23:59:59.000Z

128

Multi-Phase Galaxy Formation and Quasar Absorption Systems  

E-Print Network (OSTI)

Abstract. The central problem of galaxy formation is understanding the cooling and condensation of gas in dark matter halos. It is now clear that to match observations this requires further physics than the simple assumptions of single phase gas cooling. A model of multi-phase cooling (Maller & Bullock 2004) can successfully account for the upper cutoff in the masses of galaxies and provides a natural explanation of many types of absorption systems (Mo & Miralda-Escude 1996). Absorption systems are our best probes of the gaseous content of galaxy halos and therefore provide important constraints on models for gas cooling into galaxies. All physical processes that effect gas cooling redistribute gas and therefore are detectable in absorption systems. Detailed studies of the nature of gas in galaxy halos using absorption systems are crucial for building a correct theory of galaxy formation.

P. R. Williams; C. Shu; B. Mnard; Ariyeh H. Maller

2005-01-01T23:59:59.000Z

129

Multi-Phase Galaxy Formation and Quasar Absorption Systems  

E-Print Network (OSTI)

The central problem of galaxy formation is understanding the cooling and condensation of gas in dark matter halos. It is now clear that to match observations this requires further physics than the simple assumptions of single phase gas cooling. A model of multi-phase cooling (Maller & Bullock 2004) can successfully account for the upper cutoff in the masses of galaxies and provides a natural explanation of many types of absorption systems (Mo & Miralda-Escude 1996). Absorption systems are our best probes of the gaseous content of galaxy halos and therefore provide important constraints on models for gas cooling into galaxies. All physical processes that effect gas cooling redistribute gas and therefore are detectable in absorption systems. Detailed studies of the nature of gas in galaxy halos using absorption systems are crucial for building a correct theory of galaxy formation.

Ariyeh H. Maller

2005-05-06T23:59:59.000Z

130

Multi-Phase Galaxy Formation and Quasar Absorption Systems  

E-Print Network (OSTI)

The central problem of galaxy formation is understanding the cooling and condensation of gas in dark matter halos. It is now clear that to match observations this requires further physics than the simple assumptions of single phase gas cooling. A model of multi-phase cooling (Maller & Bullock 2004) can successfully account for the upper cutoff in the masses of galaxies and provides a natural explanation of many types of absorption systems (Mo & Miralda-Escude 1996). Absorption systems are our best probes of the gaseous content of galaxy halos and therefore provide important constraints on models for gas cooling into galaxies. All physical processes that effect gas cooling redistribute gas and therefore are detectable in absorption systems. Detailed studies of the nature of gas in galaxy halos using absorption systems are crucial for building a correct theory of galaxy formation.

Maller, A H

2005-01-01T23:59:59.000Z

131

Gas Absorption into a Moving Spheroidal Water Drop  

Science Conference Proceedings (OSTI)

Theoretical and experimental studies have been carried out to describe the absorption of sulfur dioxide by moving spheroidal water drops under transient flow conditions. These investigations allow the determination of the rate at which SO2 is ...

H. Amokrane; B. Caussade

1999-06-01T23:59:59.000Z

132

A Theory of Gravity Wave Absorption by a Boundary Layer  

Science Conference Proceedings (OSTI)

A one-layer model of the atmospheric boundary layer (BL) is proposed to explain the nature of lee-wave attenuation and gravity wave absorption seen in numerical simulations. Two complex coefficients are defined: the compliance coefficient and the ...

Ronald B. Smith; Qingfang Jiang; James D. Doyle

2006-02-01T23:59:59.000Z

133

Heat and Mass transfer in an absorption process with mixed absorbent solution.  

E-Print Network (OSTI)

??Falling film absorption process is studied for the simulation of the absorber of the absorption solar cooling system. In this study, we use different absorbents (more)

Chi, Ten-yen

2011-01-01T23:59:59.000Z

134

Quantifying Cloud-Induced Shortwave Absorption: An Examination of Uncertainties and of Recent Arguments for Large Excess Absorption  

Science Conference Proceedings (OSTI)

The quantification of cloud-induced shortwave atmospheric absorption is a painstaking task and often the subject of contention. Several analytical methods previously used for this purpose are examined in detail applying each method to a set of ...

D. G. Imre; E. H. Abramson; P. H. Daum

1996-11-01T23:59:59.000Z

135

Characterizing the formation of secondary organic aerosols  

E-Print Network (OSTI)

and Flagan, R.C. (1990) Aerosol Sci. and Technol. 13 , 230.and Seinfeld, J.H. (2002) Aerosol Science and Technology ,light absorption by atmospheric aerosol, in preparation for

Lunden, Melissa; Black, Douglas; Brown, Nancy

2004-01-01T23:59:59.000Z

136

Dynamic Absorption Model for Off-Gas Separation  

Science Conference Proceedings (OSTI)

Modeling and simulations will aid in the future design of U.S. advanced reprocessing plants for the recovery and recycle of actinides in used nuclear fuel. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, a rate based, dynamic absorption model is being developed in gPROMS software. Inputs include liquid and gas stream constituents, column properties, liquid and gas phase reactions, number of stages, and inlet conditions. It simulates multiple component absorption with countercurrent flow and accounts for absorption by mass transfer and chemical reaction. The assumption of each stage being a discrete well-mixed entity was made. Therefore, the model is solved stagewise. The simulation outputs component concentrations in both phases as a function of time from which the rate of absorption is determined. Temperature of both phases is output as a function of time also. The model will be used able to be used as a standalone model in addition to in series with other off-gas separation unit operations. The current model is being generated based on NOx absorption; however, a future goal is to develop a CO2 specific model. The model will have the capability to be modified for additional absorption systems. The off-gas models, both adsorption and absorption, will be made available via the server or web for evaluation by customers.

Veronica J. Rutledge

2011-07-01T23:59:59.000Z

137

Properties of O VI Absorption in the Local Interstellar Medium  

E-Print Network (OSTI)

We report on the properties of LISM O VI absorption observed with 20 km/s resolution FUSE observations of 39 white dwarfs (WDs) ranging in distance from 37 to 230 pc with a median distance of 109 pc. LISM O VI is detected with >2sigma significance along 24 of 39 lines of sight. The column densities range from log N(O VI) = 12.38 to 13.60 with a median value of 13.10. The line of sight volume density, n(O VI) = N(O VI)/d exhibits a large dispersion ranging from (0.68 to 13.0)x10(-8) cm(-3) with an average value 3.6x10(-8) cm(-3) twice larger than found for more distant sight lines in the Galactic disk. The narrowest profiles are consistent with thermal Doppler broadening of O VI near its temperature of peak abundance, 2.8x10(5) K. Comparison of the average velocities of O VI and C II absorption reveals 10 cases where the O VI absorption is closely aligned with the C II absorption as expected if the O VI is formed in a condensing interface between the cool and warm absorption and a hot exterior gas. The comparison also reveals 13 cases where O VI absorption is displaced to positive velocity by 7 to 29 km/s from the average velocity of C II. The positive velocity O VI appears to be tracing the evaporative flow of O VI from a young interface between warm gas and a hot exterior medium. However, it is possible the positive velocity O VI is instead tracing cooling hot Local Bubble (LB) gas. The properties of the O VI absorption in the LISM are broadly consistent with the expectations of the theory of conductive interfaces caught in the old condensing phase and possibly in the young evaporative phase of their evolution.

Blair D. Savage; Nicholas Lehner

2005-09-15T23:59:59.000Z

138

High throughput liquid absorption preconcentrator sampling instrument  

DOE Patents (OSTI)

A system for detecting trace concentrations of an analyte in air includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container comprising a wettable material. The wettable material is continuously wetted with an analyte-sorbing liquid which flows from one part of the container to a lower end. Sampled air flows through the container in contact with the wetted material with a swirling motion which results in efficient transfer of analyte vapors or aerosol particles to the sorbing liquid and preconcentration of traces of analyte in the liquid. The preconcentrated traces of analyte may be either detected within the container or removed therefrom for injection into a separate detection means or for subsequent analysis. 12 figs.

Zaromb, S.; Bozen, R.M.

1990-03-26T23:59:59.000Z

139

X-RAY ABSORPTION OF HIGH-REDSHIFT QUASARS  

SciTech Connect

The soft X-ray photoelectric absorption of high-z quasars has been known for two decades, but has no unambiguous astrophysical context. We construct the largest sample to date of 58 high-redshift quasars (z > 0.45) selected from the XMM-Newton archive based on a high photon count criterion (>1800). We measure the optical depth {tau} at 0.5 keV and find that 43% of the quasars show significant absorption. We aim to find which physical parameters of the quasars, e.g., redshift, radio luminosity, radio loudness, or X-ray luminosity, drive their observed absorption. We compare the absorption behavior with redshift with the pattern expected if the diffuse intergalactic medium (IGM) is responsible for the observed absorption. We also compare the absorption with a comparison sample of gamma-ray burst (GRB) X-ray afterglows. Although the z > 2 quasar opacity is consistent with diffuse IGM absorption, many intermediate-z (0.45 < z < 2) quasars are not sufficiently absorbed for this scenario, and are appreciably less absorbed than GRBs. Only 10/37 quasars at z < 2 are absorbed, and only 5/30 radio-quiet quasars are absorbed. We find a weak correlation between {tau} and z, and an even weaker correlation between {tau} and radio luminosity. These findings lead to the conclusion that although a diffuse IGM origin for the quasar absorption is unlikely, the optical depth does seem to increase with redshift, roughly as (1 + z){sup 2.2{+-}0.6}, tending to {tau} Almost-Equal-To 0.4 at high redshifts, similar to the high-z GRBs. This result can be explained by an ionized and clumpy IGM at z < 2, and a cold, diffuse IGM at higher redshift. If, conversely, the absorption occurs at the quasar, and owing to the steep L{sub x} {proportional_to}(1 + z){sup 7.1{+-}0.5} correlation in the present sample, the host column density scales as N{sub H}{proportional_to}L{sub x}{sup 0.7{+-}0.1}.

Eitan, Assaf; Behar, Ehud, E-mail: sassafe@tx.technion.ac.il, E-mail: behar@physics.technion.ac.il [Physics Department, Technion, Haifa 32000 (Israel)

2013-09-01T23:59:59.000Z

140

Simulated X-Ray Absorption Spectroscopy on the Water Dimer  

DOE Green Energy (OSTI)

The ability of an individual H{sub 2}O molecule to form multiple hydrogen bonds with neighboring molecules makes it an ideal substance for the study of hydrogen bonding. X-ray absorption spectroscopy (XAS) can be used to study what intermolecular structures the hydrogen-bonded water molecules form. XAS excites core electrons from the oxygen 1 s atomic orbital to an unoccupied orbital. The resulting absorption spectrum shows the energy levels of the unoccupied orbitals, which in turn is dependent on the intermolecular structure of the H{sub 2}O system. Previous studies using molecular dynamics computer simulations have concluded that the intermolecular structure of liquid water is a distorted tetrahedron. Yet x-ray absorption spectra show discrepancies between liquid water and ice Ih, which is already known to have a rigid tetrahedral structure. The research group, which is based in the University of Sweden in Stockholm and the Stanford Synchrotron Radiation Laboratory at the Stanford Linear Accelerator Center, has studied the possible presence of broken hydrogen bonds in the liquid water intermolecular structure to explain these deviations. Computer simulations are used to construct theoretical absorption spectra for models of liquid water including broken hydrogen bonds. Creating such models requires controlling variables. The simplest method of isolating individual variables, such as hydrogen bond length and angles, is to study the water dimer. Here, the water dimer is used to study how the absorption spectra change with the way the water molecules are positioned and oriented relative to each other.

Wung, A

2004-02-05T23:59:59.000Z

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


141

Contribution of organic carbon to wood smoke particulate matter absorption  

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

Contribution of organic carbon to wood smoke particulate matter absorption Contribution of organic carbon to wood smoke particulate matter absorption of solar radiation Title Contribution of organic carbon to wood smoke particulate matter absorption of solar radiation Publication Type Journal Article Year of Publication 2012 Authors Kirchstetter, Thomas W., and Tracy L. Thatcher Journal Atmospheric Chemistry and Physics Volume 12 Pagination 6067-6072 Abstract A spectroscopic analysis of 115 wintertime partic- ulate matter samples collected in rural California shows that wood smoke absorbs solar radiation with a strong spectral se- lectivity. This is consistent with prior work that has demon- strated that organic carbon (OC), in addition to black car- bon (BC), appreciably absorbs solar radiation in the visible and ultraviolet spectral regions. We apportion light absorp-

142

Laser supported solid state absorption fronts in silica  

SciTech Connect

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

Carr, C W; Bude, J D

2010-02-09T23:59:59.000Z

143

tude des machines frigorifiques absorption et absorption-diffusion utilisant un mlange d'alcanes : tude systmique et modlisation rigoureuse de l'absorbeur.  

E-Print Network (OSTI)

??Le prsent travail est consacr en premier lieu l'investigation des limites de fonctionnement et de performances des machines frigorifiques absorption et absorption-diffusion utilisant (more)

Dardour, Houda

2012-01-01T23:59:59.000Z

144

Direct Refrigeration from Heat Recovery Using 2-Stage Absorption Chillers  

E-Print Network (OSTI)

Although the cost of some fossil fuels has moderated, the importance of energy conservation by heat recovery has not diminished. The application of waste heat generated steam to produce chilled water is not new. However, there is a newly developed absorption chiller which can produce chilled water 44% more efficiently than the conventional single stage absorption chillers. The new 2-stage parallel flow system makes the chiller package more compact, more efficient, and easier to operate. Many types of waste heat, not just steam, can be used directly in this new chiller without the need for costly recovery and conversion systems.

Hufford, P. E.

1983-01-01T23:59:59.000Z

145

Overview of active solar absorption/Rankine cooling program  

DOE Green Energy (OSTI)

The individual absorption and Rankine projects are identified, along with the main features and accomplishments/status of each and future plans. Included are four projects funded by SOLERAS, a joint US/Saudi Arabian effort. In the absorption program, there are three active component development projects, four systems field test projects, one advanced fluid study project and one advanced cycle study project currently funded by DOE. In the Rankine program, there are five active component development projects, two system field test projects, and one advanced study project. (LEW)

Wahlig, M.; Heitz, A.; Angerman, H.; Glas, R.; Warren, M.

1981-07-01T23:59:59.000Z

146

Solar evacuated tube collector: absorption chiller systems simulation  

DOE Green Energy (OSTI)

A residential air conditioning system incorporating an Arkla Solaire absorption chiller and Corning Glass Works evacuated tube collectors is simulated and the design parameters studied. Mathematical models of the evacuated tube collector and Arkla absorption chiller based on experimental results of the components have been created and incorporated into a complete system simulation. The chiller model includes transient start-up effects and the evacuated tube collector model includes numerous optical effects. A standard Arkla chiller in a humid climate (Washington, D.C.) and an Arkla unit with a modified charge for dry climates (Fort Collins, Colorado) are studied. Design parameters considered include the use of chilled water storage to reduce transient start-up effects of the absorption unit, the effects of removing heat from the solar system for preheating service hot water, the use of a tempering valve to prevent over-firing of the absorption unit in dry climates, and solar storage sizing considerations. The study results and conclusions are used to specify a cooling system design.

Leflar, J.A.; Duff, W.S.

1977-12-01T23:59:59.000Z

147

Methods for deacidizing gaseous mixtures by phase enhanced absorption  

SciTech Connect

An improved process for deacidizing a gaseous mixture using phase enhanced gas-liquid absorption is described. The process utilizes a multiphasic absorbent that absorbs an acid gas at increased rate and leads to reduced overall energy costs for the deacidizing operation.

Hu, Liang

2012-11-27T23:59:59.000Z

148

Water-lithium bromide double-effect absorption cooling analysis  

SciTech Connect

A numerical model was developed for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine, and the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very-important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy.

Vliet, G.C.; Lawson, M.B.; Lithgow, R.A.

1980-12-01T23:59:59.000Z

149

Absorption Approximation with Scattering Effect for Infrared Radiation  

Science Conference Proceedings (OSTI)

A scheme that can handle cloud infrared scattering based on the absorption approximation is developed. In a two-stream mode, the new scheme produces more accurate results than those from the modified two-stream discrete ordinate method. For low ...

J. Li; Qiang Fu

2000-09-01T23:59:59.000Z

150

Microwave Absorption Measurements of Melting Spherical and Nonspherical Hydrometeors  

Science Conference Proceedings (OSTI)

Measurements were made of the absorption behavior of melting and freezing hydrometeors using resonant cavity perturbation techniques at a wavelength of 2.82 cm. Melting ice spheres with equivalent melted diameters between 1.15 and 2.00 mm exhibit ...

Robert John Hansman Jr.

1986-08-01T23:59:59.000Z

151

RECTIFIED ABSORPTION METHOD FOR THE SEPARATION OF HYDROGEN ISOTOPES  

DOE Patents (OSTI)

A method is described for separating and recovering heavy hydrogen isotopes from gaseous mixtures by multiple stage cyclic absorption and rectification from an approximate solvent. In particular, it is useful for recovering such isoteoes from ammonia feedstock streams containing nitrogen solvent. Modifications of the process ranging from isobaric to isothermal are provided. Certain impurities are tolerated, giving advantages over conventional fractional distillation processes. (AEC)

Hunt, C.D.; Hanson, D.N.

1961-10-17T23:59:59.000Z

152

H{alpha} ABSORPTION IN TRANSITING EXOPLANET ATMOSPHERES  

SciTech Connect

Absorption of stellar H{alpha} by the upper atmosphere of the planet HD 189733b has recently been detected by Jensen et al. Motivated by this observation, we have developed a model for atomic hydrogen in the n = 2 state and compared the resulting H{alpha} line profile to the observations. The model atmosphere is in hydrostatic balance, as well as thermal and photoionization equilibrium. Collisional and radiative transitions are included in the determination of the n = 2 state level population. We find that H{alpha} absorption is dominated by an optical depth {tau} {approx} 1 shell, composed of hydrogen in the metastable 2s state that is located below the hydrogen ionization layer. The number density of the 2s state within the shell is found to vary slowly with radius, while that of the 1s state falls rapidly. Thus while the Ly{alpha} absorption, for a certain wavelength, occurs inside a relatively well defined impact parameter, the contribution to H{alpha} absorption is roughly uniform over the entire atomic hydrogen layer. The model can approximately reproduce the observed Ly{alpha} and H{alpha} integrated transit depths for HD 189733b by using an ionization rate enhanced over that expected for the star by an order of magnitude. For HD 209458b, we are unable to explain the asymmetric H{alpha} line profile observed by Jensen et al., as the model produces a symmetric line profile with transit depth comparable to that of HD 189733b. In an appendix, we study the effect of the stellar Ly{alpha} absorption on the net cooling rate.

Christie, Duncan; Arras, Phil; Li Zhiyun, E-mail: dac5zm@virginia.edu, E-mail: pla7y@virginia.edu, E-mail: zl4h@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

2013-08-01T23:59:59.000Z

153

Temperature activated absorption during laser-induced damage: The evolution of laser-supported solid-state absorption fronts  

SciTech Connect

Previously we have shown that the size of laser induced damage sites in both KDP and SiO{sub 2} is largely governed by the duration of the laser pulse which creates them. Here we present a model based on experiment and simulation that accounts for this behavior. Specifically, we show that solid-state laser-supported absorption fronts are generated during a damage event and that these fronts propagate at constant velocities for laser intensities up to 4 GW/cm{sup 2}. It is the constant absorption front velocity that leads to the dependence of laser damage site size on pulse duration. We show that these absorption fronts are driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport, and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. In addition to the practical application of selecting an optimal laser for pre-initiation of large aperture optics, this work serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.

Carr, C W; Bude, J D; Shen, N; Demange, P

2010-10-26T23:59:59.000Z

154

Enhanced Solar Energy Absorption by Internally-mixed Black Carbon in Snow Grains  

Science Conference Proceedings (OSTI)

Here we explore light absorption by snowpack containing black carbon (BC) particles residing within ice grains. Basic considerations of particle volumes and BC/snow mass concentrations show that there are generally 0:05-109 BC particles for each ice grain. This suggests that internal BC is likely distributed as multiple inclusions within ice grains, and thus the dynamic effective medium approximation (DEMA) (Chylek and Srivastava, 1983) is a more appropriate optical representation for BC/ice composites than coated-sphere or standard mixing approximations. DEMA calculations show that the 460 nm absorption cross-section of BC/ice composites, normalized to the mass of BC, is typically enhanced by factors of 1.8-2.1 relative to interstitial BC. BC effective radius is the dominant cause of variation in this enhancement, compared with ice grain size and BC volume fraction. We apply two atmospheric aerosol models that simulate interstitial and within-hydrometeor BC lifecycles. Although only {approx}2% of the atmospheric BC burden is cloud-borne, 71-83% of the BC deposited to global snow and sea-ice surfaces occurs within hydrometeors. Key processes responsible for within-snow BC deposition are development of hydrophilic coatings on BC, activation of liquid droplets, and subsequent snow formation through riming or ice nucleation by other species and aggregation/accretion of ice particles. Applying deposition fields from these aerosol models in offline snow and sea-ice simulations, we calculate that 32-73% of BC in global surface snow resides within ice grains. This fraction is smaller than the within-hydrometeor deposition fraction because meltwater flux preferentially removes internal BC, while sublimation and freezing within snowpack expose internal BC. Incorporating the DEMA into a global climate model, we simulate increases in BC/snow radiative forcing of 43-86%, relative to scenarios that apply external optical properties to all BC. We show that snow metamorphism driven by diffusive vapor transfer likely proceeds too slowly to alter the mass of internal BC while it is radiatively active, but neglected processes like wind pumping and convection may play much larger roles. These results suggest that a large portion of BC in surface snowpack may reside within ice grains and increase BC/snow radiative forcing, although measurements to evaluate this are lacking. Finally, previous studies of BC/snow forcing that neglected this absorption enhancement are not necessarily biased low, because of application of absorption-enhancing sulfate coatings to hydrophilic BC, neglect of coincident absorption by dust in snow, and implicit treatment of cloud-borne BC resulting in longer-range transport.

Flanner, M. G.; Liu, Xiaohong; Zhou, Cheng; Penner, Joyce E.; Jiao, C.

2012-05-30T23:59:59.000Z

155

The Influence of Dust on the Absorptivity of Radiant Barriers  

E-Print Network (OSTI)

The purpose of this project was to model and quantify the increase of the absorptivity of radiant barriers caused by the accumulation of dust on the surface of radiant barriers. This research was the continuation of a previous work by the author at Texas A&M University in which a radiation energy balance inside the attic enclosure was developed. The particles were considered as flat, circular planes, all having the same radii. That early model showed that there was a linear relationship between the fraction of area of the foil covered by dust and the mean absorptivity of the dusty radiant barrier. In the present work, it was found that the assumption of treating the dust particles as plane circles, underestimated the effective area of the particles by about 20%. Experimental measurements indicated that dust particles achieved the same temperature as the radiant barrier. The new model used the linear relationship just described, and simulated the dust particles as flat circular planes having random radii and laying in random locations within the radiant barrier surface. The new model calculated the fraction of radiant barrier area covered by particles using a digital array in which the clean barrier was represented as zeroes and the dust particles were represented as a set of ones appropriately dimensioned inside the array. The experimentation used natural dust and Arizona Road Test Dust. Using an infrared emissometer, the emissivities (absorptivities) of the clean and dusty barriers were measured and using an electronic scale, the dust loading was measured. An electron microscope was used to experimentally find the fraction of radiant barrier covered by the dust particles to correlate the experimentally found absorptivity with the experimentally found fraction of dust coverage. The limited experimental data available were also used to correlate the absorptivity of the dusty radiant barrier with the time of dust accumulation and the location of the barrier inside the attic. A linear relationship between the absorptivity and the time of dust accumulation was found that can be applied to predict future barrier effectiveness based upon the rate of dust accumulation for a given location.

Noboa, Homero L.

1993-08-01T23:59:59.000Z

156

INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS  

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

mNAL PERFORMANCE REPORT mNAL PERFORMANCE REPORT for INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS DE-FG05-85ER13439 1-AUG-1985 to 31-JUL-1994 Robert F. Curl and Graham P. Glass Principal Investigators Introduction This research was directed at the detection, monitoring, and study (by infrared absorption spectroscopy) of the chemical kinetic behavior of small free radical species thought to be important intermediates in combustion. The work typically progressed from the detection and analysis of the infrared spectrum of combustion radical to the utilization of the infrared spectrum thus obtained in the investigation of chemical kinetics of the radical species. The methodology employed was infrared kinetic spectroscopy. In this technique the radical is produced by UV flash photolysis using an excimer laser and then

157

Absorption Spectra and Plotting Exciton Wavefunctions BerkeleyGW Workshop  

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

Hands on Session 5: Converging Hands on Session 5: Converging Absorption Spectra and Plotting Exciton Wavefunctions BerkeleyGW Workshop 11/23/2013 Diana Qiu Converging Absorption General Parameters: ● K-grid sampling (WFN_fi, WFNq_fi) - Generally need to be finer when excitons are localized in k-space ● Number of valence bands and conduction bands (eqp.dat) - Needs to capture all the transitions in the energy range of interest Parameters Particular to BGW: ● Coarse k-grid (WFN_co, same as for epsilon) - Need to be fine enough to capture correct screening ● Number of coarse grid bands used in interpolation (eqp_co.dat) - Interpolation quality reported in dcc_mat.dat and dvv_mat.dat files Plotting Exciton Wavefunctions ● Plotxct.x calculates the exciton wavefunction in real-space with the

158

Lithium bromide absorption chiller passes gas conditioning field test  

Science Conference Proceedings (OSTI)

A lithium bromide absorption chiller has been successfully used to provide refrigeration for field conditioning of natural gas. The intent of the study was to identify a process that could provide a moderate level of refrigeration necessary to meet the quality restrictions required by natural-gas transmission companies, minimize the initial investment risk, and reduce operating expenses. The technology in the test proved comparatively less expensive to operate than a propane refrigeration plant. Volatile product prices and changes in natural-gas transmission requirements have created the need for an alternative to conventional methods of natural-gas processing. The paper describes the problems with the accumulation of condensed liquids in pipelines, gas conditioning, the lithium bromide absorption cycle, economics, performance, and operating and maintenance costs.

Lane, M.J.; Huey, M.A. [Nicol and Associates, Richardson, TX (United States)

1995-07-31T23:59:59.000Z

159

Experimental study and parameterization of gas absorption by water drops  

Science Conference Proceedings (OSTI)

Mass transfer between liquid drops and a continuous gas phase occurs in a large number of industrial processes and many engineering disciplines such as chemical and nuclear engineering, atmospheric sciences, environmental engineering, and so on. Liquid-phase mass-transfer coefficients are determined for the absorption of sulfur dioxide by water drops larger than 1.1 mm in dia. A local model based on the large eddy interfacial model proposed for Fortescue and Pearson (1967) is obtained by the characteristic interfacial scaling. In particular, the agitation process of the liquid phase in the interfacial region is characterized by the interfacial liquid friction velocity. Experiments of sulfur dioxide absorption and desorption from large individually free-falling water drops are also carried out in a 5-m rain shaft under various environmental conditions. These experimental results agree well with those from the local model characterizing the interfacial process in water drops greater than 1.1 mm in dia.

Amokrane, H.; Saboni, A.; Caussade, B. (CNRS, Toulouse (France). Inst. de Mecanique des Fluides)

1994-12-01T23:59:59.000Z

160

Radiation-induced transient absorption in optical fibers  

Science Conference Proceedings (OSTI)

Transient absorption in optical fibers has been studied with emphasis on fast absorption components. Radiation damage was induced with a Febetron 706 electron accelerator, modified to deliver an electron pulse width of 1.1 ns. Dye lasers were synchronized to the accelerator to provide a light pulse through the fiber during the radiation pulse. The output light pulse was detected with a biplanar vacuum photodiode. Four scope traces were used on each electron pulse to monitor the Febetron output, the input drive pulse, and two records of the output pulse on two sweep speeds. Detailed data were acquired for times less than 100 ns after irradiation. An insulated enslosure was used to vary fiber temperature from -30/sup 0/C to + 250/sup 0/C. Several fibers were studied with emphasis on ITT T303 PCS fiber. Data were acquired at 600 and 850 nm. Theoretical modeling of the data is presented.

Looner, L.D.; Turquet de Beauregard, G.; Lyons, P.B.; Kelly, R.E.

1981-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

WATER-LITHIUM BROMIDE DOUBLE-EFFECT ABSORPTION COOLING ANALYSIS  

Office of Scientific and Technical Information (OSTI)

WATER-LITHIUM BROMIDE DOUBLE-EFFECT WATER-LITHIUM BROMIDE DOUBLE-EFFECT ABSORPTION COOLING ANALYSIS Gary C . V l i e t , Michael B . Lawson, and Rudolf0 A . Lithgow Center f o r Energy Studies The University of Texas a t Austin December 1980 Final Report f o r Contract: DE AC03-79SF10540 (Mu1 tiple-Effect Absorption Cycle Solar Cooling) with the U.S. Department of Energy DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately

162

Phenolic Compounds of Sorghum, their Chemopreventive Properties and Absorption  

E-Print Network (OSTI)

Sorghum contains many phenolic compounds which have potential antioxidant, anti-inflammatory, and chemopreventive properties as well as natural colorants in foods. Phenolic compounds of stalks, sheaths, leaves, glumes and grains from tan (ARTx631/RTx436), red (Tx2911) and purple (Tx3362) sorghum plants were characterized by UPLC-MS/MS. Antiproliferative properties of selected sorghum extracts were evaluated using HT-29 colon cancer cells and absorption of their polyphenolics was determined by a Caco-2 in vitro model system. Phenolic acids, flavones, 3-deoxyanthocyanidins and chalcones were found in all plant components. Phenolic acids were predominant in the stalks, sheaths and grains of all sorghum types. Flavone glycosides were predominant in leaves, sheaths and stalks while flavone aglycones in glumes and grains. 3-Deoxyanthocyanidins and chalcones were mostly found in sheaths, leaves, glumes and grains of Tx2911 (red) and Tx3362 (purple) genotypes. Sorghum leaves showed high levels of flavone glycosides while glumes had high levels of flavones aglycones. Glume extract of ATx631/RTx436 (tan) and Tx2911 genotypes had the strongest antiproliferation activity (IC_(50) = 85-178 g/ml), these extracts had also the highest levels of flavone aglycones (19.6-49.8 mg/g). Absorption of flavones (30.4-42.3 %) was higher than 3-deoxyantocyanidins (1.4-11.3%), while absorption of methoxylated 3-deoxyanthocyanidins (11.3%) was higher than non-methoxylated 3-deoxyanthocyanidins (1.4 1.6 %). Flavones had high absorption compared to other sorghum phenolics suggesting that sorghum flavone aglycones are more bioavailable than other sorghum phenolic compounds. Consequently, sorghum glumes could be used as used as a source of phytochemicals to increase value of sorghum crop.

Taleon Alban, Victor Manuel

2013-08-01T23:59:59.000Z

163

Waste heat driven absorption refrigeration process and system  

DOE Patents (OSTI)

Absorption cycle refrigeration processes and systems are provided which are driven by the sensible waste heat available from industrial processes and other sources. Systems are disclosed which provide a chilled water output which can be used for comfort conditioning or the like which utilize heat from sensible waste heat sources at temperatures of less than 170.degree. F. Countercurrent flow equipment is also provided to increase the efficiency of the systems and increase the utilization of available heat.

Wilkinson, William H. (Columbus, OH)

1982-01-01T23:59:59.000Z

164

Measuring of exhaust gas emissions using absorption spectroscopy  

Science Conference Proceedings (OSTI)

This paper describes an optical fibre sensor for the detection of NOx (NO2 and NO) and CO2 in the exhaust system of a road vehicle. The measurement is based on a free path interaction zone which is interrogated using ... Keywords: absorption spectroscopy, air pollution, carbon dioxide, emissions measurement, exhaust gas emissions, gas sensors, infrared, nitrogen dioxide, nitrogen oxide, optical fibre sensors, ultraviolet, vehicle emissions

Eamonn Hawe; Gerard Dooly; Colin Fitzpatrick; Paul Chambers; Elfed Lewis; W. Z. Zhao; T. Sun; K. T. V. Grattan; M. Degner; H. Ewald; S. Lochmann; G. Bramman; C. Wei; D. Hitchen; J. Lucas; A. Al-Shamma'a; E. Merlone-Borla; P. Faraldi; M. Pidria

2008-02-01T23:59:59.000Z

165

Method for making a photodetector with enhanced light absorption  

DOE Patents (OSTI)

A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

Kane, James (Lawrenceville, NJ)

1987-05-05T23:59:59.000Z

166

Absorption of ion Bernstein waves by impurity cyclotron harmonics  

DOE Green Energy (OSTI)

This paper analyzes the damping of externally-launched ion Bernstein waves by absorption at the cyclotron harmonics of the impurity ions. The inclusion of the non-magnetic energy flux term reduces the damping rate by nearly two orders of magnitude from the previous calculation. Excessive impurity damping can be avoided by launching ion Bernstein waves at a frequency just below the second (or higher) cyclotron harmonic of hydrogen.

Ono, M.

1982-05-01T23:59:59.000Z

167

The resonance absorption probability function for neutron and multiplicative integral  

E-Print Network (OSTI)

The analytical approximations for the moderating neutrons flux density like Fermi spectra, widely used in reactor physics, involve the probability function for moderating neutron to avoid the resonant absorption obtained using some restrictive assumptions regarding the acceptable resonances width. By means of multiplicative integral (Volterra integral) theory for a commutative algebra an analytical expression for the probability function is obtained rigorously without any restrictive assumptions.

Rusov, V D; Kosenko, S I; Chernegenko, S A

2012-01-01T23:59:59.000Z

168

The resonance absorption probability function for neutron and multiplicative integral  

E-Print Network (OSTI)

The analytical approximations for the moderating neutrons flux density like Fermi spectra, widely used in reactor physics, involve the probability function for moderating neutron to avoid the resonant absorption obtained using some restrictive assumptions regarding the acceptable resonances width. By means of multiplicative integral (Volterra integral) theory for a commutative algebra an analytical expression for the probability function is obtained rigorously without any restrictive assumptions.

V. D. Rusov; V. A. Tarasov; S. I. Kosenko; S. A. Chernegenko

2012-08-05T23:59:59.000Z

169

PROMINENCE PLASMA DIAGNOSTICS THROUGH EXTREME-ULTRAVIOLET ABSORPTION  

SciTech Connect

In this paper, we introduce a new diagnostic technique that uses EUV and UV absorption to determine the electron temperature and column emission measure, as well as the He/H relative abundance of the absorbing plasma. If a realistic assumption on the geometry of the latter can be made and a spectral code such as CHIANTI is used, then this technique can also yield the absorbing plasma hydrogen and electron density. This technique capitalizes on the absorption properties of hydrogen and helium at different wavelength ranges and temperature regimes. Several cases where this technique can be successfully applied are described. This technique works best when the absorbing plasma is hotter than 15,000 K. We demonstrate this technique on AIA observations of plasma absorption during a coronal mass ejection eruption. This technique can be easily applied to existing observations of prominences and cold plasmas in the Sun from almost all space missions devoted to the study of the solar atmosphere, which we list.

Landi, E. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Reale, F. [Dipartimento di Fisica e Chimica, Universita di Palermo, Piazza del Parlamento 1, I-90134 Palermo (Italy)

2013-07-20T23:59:59.000Z

170

Waste Heat Powered Ammonia Absorption Refrigeration Unit for LPG Recovery  

SciTech Connect

An emerging DOE-sponsored technology has been deployed. The technology recovers light ends from a catalytic reformer plant using waste heat powered ammonia absorption refrigeration. It is deployed at the 17,000 bpd Bloomfield, New Mexico refinery of Western Refining Company. The technology recovers approximately 50,000 barrels per year of liquefied petroleum gas that was formerly being flared. The elimination of the flare also reduces CO2 emissions by 17,000 tons per year, plus tons per year reductions in NOx, CO, and VOCs. The waste heat is supplied directly to the absorption unit from the Unifiner effluent. The added cooling of that stream relieves a bottleneck formerly present due to restricted availability of cooling water. The 350oF Unifiner effluent is cooled to 260oF. The catalytic reformer vent gas is directly chilled to minus 25oF, and the FCC column overhead reflux is chilled by 25oF glycol. Notwithstanding a substantial cost overrun and schedule slippage, this project can now be considered a success: it is both profitable and highly beneficial to the environment. The capabilities of directly-integrated waste-heat powered ammonia absorption refrigeration and their benefits to the refining industry have been demonstrated.

Donald C, Energy Concepts Co.; Lauber, Eric, Western Refining Co.

2008-06-20T23:59:59.000Z

171

Heat exchanger bypass system for an absorption refrigeration system  

DOE Patents (OSTI)

A heat exchanger bypass system for an absorption refrigeration system is disclosed. The bypass system operates to pass strong solution from the generator around the heat exchanger to the absorber of the absorption refrigeration system when strong solution builds up in the generator above a selected level indicative of solidification of strong solution in the heat exchanger or other such blockage. The bypass system includes a bypass line with a gooseneck located in the generator for controlling flow of strong solution into the bypass line and for preventing refrigerant vapor in the generator from entering the bypass line during normal operation of the refrigeration system. Also, the bypass line includes a trap section filled with liquid for providing a barrier to maintain the normal pressure difference between the generator and the absorber even when the gooseneck of the bypass line is exposed to refrigerant vapor in the generator. Strong solution, which may accumulate in the trap section of the bypass line, is diluted, to prevent solidification, by supplying weak solution to the trap section from a purge system for the absorption refrigeration system.

Reimann, Robert C. (Lafayette, NY)

1984-01-01T23:59:59.000Z

172

Energy savings in petroleum refining using absorption heat pumping  

SciTech Connect

There is now a new and highly economic technology available for saving energy in petroleum refineries. This technology--absorption heat pumping--is gaining rapid acceptance overseas, but to date is relatively unknown and untried in the U.S. Packaged units now can be supplied in virtually any capacity rating desired. These units are economical, with paybacks typically in less than two years, and are highly reliable compared to heat pumps incorporating large rotating members. This paper provides an overview of how an absorption heat pump (AHP) works, the different configurations possible, and how they can be applied to fractional distillation in a petroleum refinery. A detailed example flowsheet and economic estimate are presented for a specific petroleum refinery application--modernization of the energy intensive alkylation unit--which is of interest currently. A stand-alone isobutane splitter is compared to a mechanically heat pumped alternative and an absorption heat pumped alternative. In general, the AHP requires less than half the capital investment of the next best alternative and provides numerous important intangible benefits as well. The AHP will show even larger margins of advantage on columns involving higher temperature differentials between top and bottom (temperature ''lifts'').

Davidson, W.F.; Campagne, W.V.L.

1985-03-01T23:59:59.000Z

173

Calibration of X-ray absorption in our Galaxy  

E-Print Network (OSTI)

Prediction of the soft X-ray absorption along lines of sight through our Galaxy is crucial for understanding the spectra of extragalactic sources, but requires a good estimate of the foreground column density of photoelectric absorbing species. Assuming uniform elemental abundances this reduces to having a good estimate of the total hydrogen column density, N(Htot)=N(HI)+2N(H2). The atomic component, N(HI), is reliably provided using the mapped 21 cm radio emission but estimating the molecular hydrogen column density, N(H2), expected for any particular direction, is difficult. The X-ray afterglows of GRBs are ideal sources to probe X-ray absorption in our Galaxy because they are extragalactic, numerous, bright, have simple spectra and occur randomly across the entire sky. We describe an empirical method, utilizing 493 afterglows detected by the Swift XRT, to determine N(Htot) through the Milky Way which provides an improved estimate of the X-ray absorption in our Galaxy and thereby leads to more reliable meas...

Willingale, R; Beardmore, A P; Tanvir, N R; O'Brien, P T

2013-01-01T23:59:59.000Z

174

Building Technologies Office: Gas-Fired Absorption Heat Pump Water Heater  

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

Gas-Fired Absorption Gas-Fired Absorption Heat Pump Water Heater Research Project to someone by E-mail Share Building Technologies Office: Gas-Fired Absorption Heat Pump Water Heater Research Project on Facebook Tweet about Building Technologies Office: Gas-Fired Absorption Heat Pump Water Heater Research Project on Twitter Bookmark Building Technologies Office: Gas-Fired Absorption Heat Pump Water Heater Research Project on Google Bookmark Building Technologies Office: Gas-Fired Absorption Heat Pump Water Heater Research Project on Delicious Rank Building Technologies Office: Gas-Fired Absorption Heat Pump Water Heater Research Project on Digg Find More places to share Building Technologies Office: Gas-Fired Absorption Heat Pump Water Heater Research Project on AddThis.com...

175

Effects of Enhanced Shortwave Absorption on Coupled Simulations of the Tropical Climate System  

Science Conference Proceedings (OSTI)

The effects of enhanced shortwave absorption on coupled simulations of the tropical climate have been tested using the National Center for Atmospheric Research Climate System Model. The enhancement in cloudy-sky shortwave absorption is consistent ...

William D. Collins

2001-03-01T23:59:59.000Z

176

Evaluation and Improvement of an Iterative Scattering Correction Scheme for in situ Absorption and Attenuation Measurements  

Science Conference Proceedings (OSTI)

The performance of several scattering correction schemes for reflecting-tube absorption and beam attenuation measurements is evaluated with data collected in European shelf seas. Standard scattering correction procedures for absorption ...

David McKee; Jacek Piskozub; Rdiger Rttgers; Rick A. Reynolds

2013-07-01T23:59:59.000Z

177

Practical Handbook of Soybean Processing and UtilizationChapter 12 Bleaching/Absorption Treatment  

Science Conference Proceedings (OSTI)

Practical Handbook of Soybean Processing and Utilization Chapter 12 Bleaching/Absorption Treatment Processing eChapters Processing AOCS Press Downloadable pdf of Chapter 12 Bleaching/Absorption Treatment fro

178

Advantages and disadvantages of using absorption chillers to lower utility bills  

SciTech Connect

Absorption chillers have a proven history of providing low-cost reliable cooling and should continue to do so in the future. Absorption chiller systems can provide significant energy savings for a particular application. To maximize savings, the various system arrangements should be evaluated; for example, single effect versus double effect, chiller versus chiller/heater, straight absorption chiller or the electric/absorption hybrid.

Kistler, P.

1997-04-01T23:59:59.000Z

179

ABSORPTION HEAT PUMP SYSTEM AND METHOD OF USING THE SAME - Energy ...  

An absorption heat pump system that can include a first assembly, ... Building Energy Efficiency; ... Solar Thermal; Startup America;

180

New packing in absorption systems for trapping benzene from coke-oven gas  

SciTech Connect

The efficiency of benzene removal from coke-oven gas in absorption units OAO Alchevskkoks with new packing is assessed.

V.V. Grabko; V.M. Li; T.A. Shevchenko; M.A. Solov'ev [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

2009-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


181

X-ray Absorption in Type II Quasars: Implications for the Equatorial Paradigm of Broad Absorption Line Quasars  

E-Print Network (OSTI)

In this article, the hydrogen column densities derived from X-ray observations of type II (hidden) quasars and broad absorption line quasars (BALQSOs) are compared. These column densities represent the amount of absorbing material between the X-ray source and the observer. A sample of type II QSOs with strong narrow emission lines, weak UV continuum and no broad emission lines that also have deep X-ray observations was collected from the literature for analysis. The standard model of equatorial BAL (broad absorption line) winds predicts that the column densities of this type II QSO sample should significantly exceed BALQSO column densities. Based on the existing published deep hard X-ray observations this does not seem to be true, the BALQSO absorption columns are anomalously large. Actually, the limited existing data indicate that BALQSOs have column densities which are larger than the type II QSO column densities at a statistically significant level. The implication to BAL outflows and the fundamental physical geometry of QSOs is discussed.

Brian Punsly

2006-05-01T23:59:59.000Z

182

A Numerical Model for the Dynamic Simulation of a Recirculation Single-Effect Absorption Chiller  

E-Print Network (OSTI)

A Numerical Model for the Dynamic Simulation of a Recirculation Single- Effect Absorption Chiller A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller. Keywords: absorption; chiller; modelling; transient; water-lithium bromide; falling film hal-00713904

Recanati, Catherine

183

Theoretical and Experimental Analysis of a Single Stage Ammonia-Water Absorption Chiller Performance  

Science Conference Proceedings (OSTI)

The ammonia-water absorption chillers are thermally driven devices producing a cooling effect. It can be operated without any use of electrical or mechanical energy. The advantage of absorption chillers is precisely that they can utilize low grade energy. ... Keywords: absorption system, performance, ammonia-water, thermodynamic model

Kong Dingfeng; Liu Jianhua; Zhang Liang; Zheng Guangping; Fang Zhiyun

2009-10-01T23:59:59.000Z

184

AN AMMONIA-WATER ABSORPTION-HIAT-PUMP CYCLE Donald Kuhlenschmidt, Member ASHRAE  

E-Print Network (OSTI)

. Merrick, Member ASHRAE ABSTRACT The scate-of-art in ammonia-water absorption cooling has been applied. Reversible absorption cycles for heating and cooling are possible but with additional cost and complexity concentration change making possible the use of a solution-cooled absorber wherin some heat of absorption can

Oak Ridge National Laboratory

185

Reactivation of sub-bandgap absorption in chalcogen-hyperdoped silicon  

Science Conference Proceedings (OSTI)

Silicon doped with nonequilibrium concentrations of chalcogens using a femtosecond laser exhibits near-unity absorption of sub-bandgap photons to wavelengths of at least 2500 nm. Previous studies have shown that sub-bandgap absorptance decreases with thermal annealing up to 1175 K and that the absorption deactivation correlates with chalcogen diffusivity. In this work, we show that sub-bandgap absorptance can be reactivated by annealing at temperatures between 1350 and 1550 K followed by fast cooling (>50 K/s). Our results suggest that the defects responsible for sub-bandgap absorptance are in equilibrium at high temperatures in hyperdoped Si:chalcogen systems.

Newman, Bonna K.; Buonassisi, Tonio [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Sher, Meng-Ju [Department of Physics, Harvard University, 9 Oxford Street, Cambridge, Massachusetts 02138 (United States); Mazur, Eric [Department of Physics, Harvard University, 9 Oxford Street, Cambridge, Massachusetts 02138 (United States); School of Engineering and Applied Sciences, Harvard University, 9 Oxford Street, Cambridge, Massachusetts 02138 (United States)

2011-06-20T23:59:59.000Z

186

Buffer-gas-induced absorption resonances in Rb vapor RID B-9041-2008  

E-Print Network (OSTI)

We observe transformation of the electromagnetically induced transparency (EIT) resonance into an absorption resonance in a Lambda interaction configuration in a cell filled with Rb-87 and a buffer gas. This transformation occurs as one-photon detuning of the coupling fields is varied from the atomic transition. No such absorption resonance is found in the absence of a buffer gas. The width of the absorption resonance is several times smaller than the width of the EIT resonance, and the changes of absorption near these resonances are about the same. Similar absorption resonances are detected in the Hanle configuration in a buffered cell.

Mikhailov, E. E.; Novikova, I.; Rostovtsev, Y. V.; Welch, George R.

2004-01-01T23:59:59.000Z

187

X-ray Diagnostics of Broad Absorption Line Quasar Geometry  

E-Print Network (OSTI)

A new generation of sensitive X-ray measurements are indicating that the existence of X-ray attenuation column densities, $N_{H}>10^{24}\\mathrm{cm}^{-2}$ is quite common amongst broad absorption line quasars (BALQSOs). This is significant to the geometry of the broad absorption line (BAL) outflow. In particular, such an X-ray shield also shields equatorial accretion disk winds from the UV, thereby preventing high velocity equatorial outflows from being launched. By contrast, bipolar winds initiated by continuum radiation pressure from the funnel of a slim accretion disk flare outward (like a trumpet) and offer vastly different absorbing columns to the X-ray and UV emission which are emitted from distinct regions of the disk, $\\sim 6M$ and $\\sim 10M-40M$, respectively (where $M$ is the radius of the black hole). Recent numerical work indicates that it is also possible to launch bipolar outflows from the inner regions of a thin disk. The recent discovery with VLBI that the Galactic analog of a BALQSO, the X-ray binary Circinus X-1 (with high velocity P Cygni X-ray absorption lines) is viewed virtually along the radio jet axis (and therefore along the spin axis of the black hole and the normal to the accretion disk) has rekindled interest in the bipolar models of BALQSOs. We explore this possibility by studying the nearest BAL QSO, MRK 231. High resolution 2-D optical spectroscopy and VLBI mappings of the radio jet axis indicates that the BAL outflow is parallel to the parsec scale radio jet.

Brian Punsly; Sebastian Lipari

2005-03-09T23:59:59.000Z

188

Absorption Features in Spectra of Magnetized Neutron Stars  

SciTech Connect

The X-ray spectra of some magnetized isolated neutron stars (NSs) show absorption features with equivalent widths (EWs) of 50-200 eV, whose nature is not yet well known.To explain the prominent absorption features in the soft X-ray spectra of the highly magnetized (B{approx}10{sup 14} G) X-ray dim isolated NSs (XDINSs), we theoretically investigate different NS local surface models, including naked condensed iron surfaces and partially ionized hydrogen model atmospheres, with semi-infinite and thin atmospheres above the condensed surface. We also developed a code for computing light curves and integral emergent spectra of magnetized neutron stars with various temperature and magnetic field distributions over the NS surface. We compare the general properties of the computed and observed light curves and integral spectra for XDINS RBS 1223 and conclude that the observations can be explained by a thin hydrogen atmosphere above the condensed iron surface, while the presence of a strong toroidal magnetic field component on the XDINS surface is unlikely.We suggest that the harmonically spaced absorption features in the soft X-ray spectrum of the central compact object (CCO) 1E 1207.4-5209 (hereafter 1E 1207) correspond to peaks in the energy dependence of the free-free opacity in a quantizing magnetic field, known as quantum oscillations. To explore observable properties of these quantum oscillations, we calculate models of hydrogen NS atmospheres with B{approx}10{sup 10}-10{sup 11} G(i.e., electron cyclotron energy E{sub c,e}{approx}0.1-1 keV) and T{sub eff} = 1-3 MK. Such conditions are thought to be typical for 1E 1207. We show that observable features at the electron cyclotron harmonics with EWs {approx_equal}100-200 eV can arise due to these quantum oscillations.

Suleimanov, V. [Insitute for Astronomy and Astrophysics, Kepler Center for Astro and Particle Physics, Eberhard Karls University, Sand 1, 72076 Tuebingen (Germany); Kazan Federal University, Kremlevskaya str. 18, 42008 Kazan (Russian Federation); Hambaryan, V.; Neuhaeuser, R. [Astrophysikalisches Institut und Universitaets-Sternwarte Jena, Schillergaesschen 2-3, 07745 Jena (Germany); Potekhin, A. Y. [Ioffe Physical-Technical Institute, Politekhnicheskaya str., 26, St. Petersburg 194021 (Russian Federation); Pavlov, G. G. [Pennsylvania State University, 525 Davey Lab., University Park, PA 16802 (United States); Adelsberg, M. van [Kavli Institute for Theoretical Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States); Werner, K. [Insitute for Astronomy and Astrophysics, Kepler Center for Astro and Particle Physics, Eberhard Karls University, Sand 1, 72076 Tuebingen (Germany)

2011-09-21T23:59:59.000Z

189

Modified Thermal-Optical Analysis Using Spectral Absorption Selectivity to  

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

Modified Thermal-Optical Analysis Using Spectral Absorption Selectivity to Modified Thermal-Optical Analysis Using Spectral Absorption Selectivity to Distinguish Black Carbon from Pyrolized Organic Carbon Title Modified Thermal-Optical Analysis Using Spectral Absorption Selectivity to Distinguish Black Carbon from Pyrolized Organic Carbon Publication Type Journal Article Year of Publication 2008 Authors Hadley, Odelle L., Craig E. Corrigan, and Thomas W. Kirchstetter Journal Environmental Science and Technology Volume 42 Pagination 8459-8464 Abstract This study presents a method for analyzing the black carbon (BC) mass loading on a quartz fiber filter using a modified thermal-optical analysis method, wherein light transmitted through the sample is measured over a spectral region instead of at a single wavelength. Evolution of the spectral light transmission signal depends on the relative amounts of light-absorbing BC and char, the latter of which forms when organic carbon in the sample pyrolyzes during heating. Absorption selectivities of BC and char are found to be distinct and are used to apportion the amount of light attenuated by each component in the sample. Light attenuation is converted to mass concentration on the basis of derived mass attenuation efficiencies (MAEs) of BC and char. The fractions of attenuation due to each component are scaled by their individual MAE values and added together as the total mass of light absorbing carbon (LAC). An iterative algorithm is used to find the MAE values for both BC and char that provide the best fit to the carbon mass remaining on the filter (derived from direct measurements of thermally evolved CO2) at temperatures higher than 480 degrees C. This method was applied to measure the BC concentration in precipitation samples collected in northern California. The uncertainty in the measured BC concentration of samples that contained a high concentration of organics susceptible to char ranged from 12% to 100%, depending on the mass loading of BC on the filter. The lower detection limit for this method was approximately 0.35 microg of BC, and the uncertainty approached 20% for BC mass loading greater than 1.0 microg of BC.

190

Attosecond tracking of light absorption and refraction in fullerenes  

E-Print Network (OSTI)

The collective response of matter is ubiquitous and widely exploited, e.g. in plasmonic, optical and electronic devices. Here we trace on an attosecond time scale the birth of collective excitations in a finite system and find distinct new features in this regime. Combining quantum chemical computation with quantum kinetic methods we calculate the time-dependent light absorption and refraction in fullerene that serve as indicators for the emergence of collective modes. We explain the numerically calculated novel transient features by an analytical model and point out the relevance for ultra-fast photonic and electronic applications. A scheme is proposed to measure the predicted effects via the emergent attosecond metrology.

Moskalenko, A S; Berakdar, J

2012-01-01T23:59:59.000Z

191

Hadronic absorption cross sections of B{sub c}  

Science Conference Proceedings (OSTI)

The cross sections of B{sub c} absorption by {pi} mesons are calculated using a hadronic Lagrangian based on the SU(5) flavor symmetry. Calculated cross sections are found to be in the ranges 2-7 mb and 0.2-2 mb for the processes B{sub c}{sup +}{pi}{yields}DB and B{sub c}{sup +}{pi}{yields}D*B*, respectively, when the monopole form factor is included. These results could be useful in calculating the production rate of B{sub c} mesons in relativistic heavy ion collisions.

Lodhi, M. A. K. [Department of Physics, MS 1051, Texas Tech University, Lubbock, Texas 79409 (United States); Akram, Faisal; Irfan, Shaheen [Center for High Energy Physics, Punjab University, Lahore (Pakistan)

2011-09-15T23:59:59.000Z

192

Pion absorption and rescattering in the ANP model revisited  

E-Print Network (OSTI)

Single pion leptoproduction in the region of the (3,3) resonance is currently of high interest for at least two reasons: (i) These reactions constitute an important part of the total cross section in low energy reactions and are utilized to detect neutrino oscillations in current and future long baseline experiments. (ii) Intranuclear rescattering of the pions in heavy nuclei results in interesting and sizable modifications of the free nucleon cross sections which are testable in electroproduction experiments. In this article we give a basic introduction to the pion multiple scattering model of Adler, Nussinov, and Paschos (ANP) with special emphasis on pion absorption. We also estimate the probability of multiple scattering.

Schienbein, I

2003-01-01T23:59:59.000Z

193

Pion absorption and rescattering in the ANP model revisited  

E-Print Network (OSTI)

Single pion leptoproduction in the region of the (3,3) resonance is currently of high interest for at least two reasons: (i) These reactions constitute an important part of the total cross section in low energy reactions and are utilized to detect neutrino oscillations in current and future long baseline experiments. (ii) Intranuclear rescattering of the pions in heavy nuclei results in interesting and sizable modifications of the free nucleon cross sections which are testable in electroproduction experiments. In this article we give a basic introduction to the pion multiple scattering model of Adler, Nussinov, and Paschos (ANP) with special emphasis on pion absorption. We also estimate the probability of multiple scattering.

I. Schienbein; J. -Y. Yu

2003-08-01T23:59:59.000Z

194

Remark on: the neutron spherical optical-model absorption.  

SciTech Connect

The energy-dependent behavior of the absorption term of the spherical neutron optical potential for doubly magic {sup 208}Pb and the neighboring {sup 209}Bi is examined. These considerations suggest a phenomenological model that results in an intuitively attractive energy dependence of the imaginary potential that provides a good description of the observed neutron cross sections and that is qualitatively consistent with theoretical concepts. At the same time it provides an alternative to some of the arbitrary assumptions involved in many conventional optical-model interpretations reported in the literature and reduces the number of the parameters of the model.

Smith, A. B.; Nuclear Engineering Division

2007-06-30T23:59:59.000Z

195

Bubble Pump Design for Single Pressure Absorption Refrigeration Cycles  

E-Print Network (OSTI)

A model has been developed for the design and optimization of a small bubble pump to be used in a single pressure absorption refrigeration cycle to lift the working fluid mixture against gravity and overcome flow friction. This analytical model is developed from two-phase flow fundamentals and incorporates the design parameters of the bubble pump. Parametric studies are carried out and a design optimization for maximum efficiency is performed for various operating conditions. Optimum efficiency is defined as the liquid pumped per unit of bubble pump heat input. The results show the optimum bubble pump tube diameter over a range of operating conditions.

Sam V. Shelton; Susan White Stewart

2002-01-01T23:59:59.000Z

196

High Energy Absorption Top Nozzle For A Nuclaer Fuel Assembly  

DOE Patents (OSTI)

A high energy absorption top nozzle for a nuclear fuel assembly that employs an elongated upper tubular housing and an elongated lower tubular housing slidable within the upper tubular housing. The upper and lower housings are biased away from each other by a plurality of longitudinally extending springs that are restrained by a longitudinally moveable piston whose upward travel is limited within the upper housing. The energy imparted to the nozzle by a control rod scram is mostly absorbed by the springs and the hydraulic affect of the piston within the nozzle.

Sparrow, James A. (Irmo, SC); Aleshin, Yuriy (Columbia, SC); Slyeptsov, Aleksey (Columbia, SC)

2004-05-18T23:59:59.000Z

197

Absorption of chromium and reduction of chromate by subterranean clover  

E-Print Network (OSTI)

In order to optimize phytoremediation techniques, it is important to first understand the plant physiological processes associated with enhanced absorption and translocation of the target metal in the plant. The emphasis in the current study is with chromium. The specific objectives were to: (1) determine the oxidation state of chromium in the plant using electron paramagnetic resonance (EPR) spectroscopy and x-ray absorption near edge spectroscopy (XANES), (2) investigate the probable mode of complication in plants grown in different Cr sources by EPR spectroscopy, (3) determine the distribution of Cr in plant tissues using synchrotron x-ray fluorescent (SXRF) microphone spectroscopy, and (4) determine the effect of root plasma membrane bound ferric reductive activity on Cr(VI) absorption. Subterranean clover (Trifolium brachycalvcinum Katzn. and Morley cv. Koala), utilized because of the relatively high tolerance, absorption, and translocation of CrO??, was grown hydroponically in a nutrient solution with Cr(III)Cl?, Cr(III)-oxalate, Cr(III)-citrate, Cr(III)-EDTA or K?Cr(VI)O? at a range of concentrations and exposure times. The uptake and translocation of Cr by the plant was dependent on the form and concentration of Cr supplied. Inorganic sources of Cr(III) precipitated in or on the roots of the plants as Cr(OH)?. In all cases, Cr predominantly existed in the plant as a Cr(III)-organic complex. There is some indication that Cr(III)-citrate and Cr(III)-oxalate were absorbed by the plant and, in the case of Cr(III)-citrate, translocated to the leaves. At high Cr(VI) treatment concentrations, Cr(VI), Cr(V), and Cr(III) were observed in the roots and Cr(V) and Cr(III) in the shoots. At low concentrations the plant could effectively reduce Cr(VI) to Cr(III), which is an important component of the detoxification mechanism. At low concentrations of Cr(VI), once in the vascular system, Cr was transported as a Cr(III)-organic complex to the leaf margins. At high concentrations of Cr(VI), SXRF microphone imaging revealed higher concentrations of Cr in the leaf veins than at the margin, indicating that Cr translocation to the leaf margin might be limited by Cr toxicity. Iron deficiency enhanced Cr uptake, particularly in the roots, indicating the possible involvement of ferric reductive in Cr uptake and reduction.

Howe, Julie Ann

1999-01-01T23:59:59.000Z

198

IHT: Tools for Computing Insolation Absorption by Particle Laden Flows  

DOE Green Energy (OSTI)

This report describes IHT, a toolkit for computing radiative heat exchange between particles. Well suited for insolation absorption computations, it is also has potential applications in combustion (sooting flames), biomass gasification processes and similar processes. The algorithm is based on the 'Photon Monte Carlo' approach and implemented in a library that can be interfaced with a variety of computational fluid dynamics codes to analyze radiative heat transfer in particle-laden flows. The emphasis in this report is on the data structures and organization of IHT for developers seeking to use the IHT toolkit to add Photon Monte Carlo capabilities to their own codes.

Grout, R. W.

2013-10-01T23:59:59.000Z

199

Trans-spectral absorption and scattering of electromagnetic radiation by diesel soot  

Science Conference Proceedings (OSTI)

The mass density normalized absorption and total scattering coefficients have been measured using in situ techniques at selected wavelengths from the visible to {similar to}1 cm for soot generated by the open combustion of diesel fuel. Particle morphologies are complex although similar to those of soots of other hydrocarbons and methods of generation. An ellipsoidal model has been applied as an approximation to the often multiconnected, chainlike aerosol and then compared with the measured results. The experimental results show an approximate ({lambda}){sup {minus}1} dependence over more than five decades of wavelength data. There is only general agreement with the simplified calculations in this feature as well as in the magnitude.

Bruce, C.W. (U.S. Army Atmospheric Sciences Laboratory, White Sands Missile Range, NM 88002 (USA)); Stromberg, T.F. (New Mexico State University, Physics Department, Las Cruces, New Mexico 88003 (USA)); Gurton, K.P. (U.S. Army Atmospheric Sciences Laboratory, White Sands Missile Range, NM 88002 (USA)); Mozer, J.B. (New Mexico State University, Physics Department, Las Cruces, New Mexico 88003 (USA))

1991-04-20T23:59:59.000Z

200

Absorption process for producing oxygen and nitrogen and solution therefor  

DOE Patents (OSTI)

Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption. In an alternate mode of operation, the carrier solution is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, and at a sufficiently high temperature to keep the carrier in its deoxygenated form during desorption. Under such conditions, exceptionally high oxygen concentrations on the order of 95% to 99% are obtained, as well as a long carrier lifetime in excess of 3 months, making the process commercially feasible. 1 figure

Roman, I.C.; Baker, R.W.

1990-09-25T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Triple loop heat exchanger for an absorption refrigeration system  

DOE Patents (OSTI)

A triple loop heat exchanger for an absorption refrigeration system is disclosed. The triple loop heat exchanger comprises portions of a strong solution line for conducting relatively hot, strong solution from a generator to a solution heat exchanger of the absorption refrigeration system, conduit means for conducting relatively cool, weak solution from the solution heat exchanger to the generator, and a bypass system for conducting strong solution from the generator around the strong solution line and around the solution heat exchanger to an absorber of the refrigeration system when strong solution builds up in the generator to an undesirable level. The strong solution line and the conduit means are in heat exchange relationship with each other in the triple loop heat exchanger so that, during normal operation of the refrigeration system, heat is exchanged between the relatively hot, strong solution flowing through the strong solution line and the relatively cool, weak solution flowing through the conduit means. Also, the strong solution line and the bypass system are in heat exchange relationship in the triple loop heat exchanger so that if the normal flow path of relatively hot, strong solution flowing from the generator to an absorber is blocked, then this relatively, hot strong solution which will then be flowing through the bypass system in the triple loop heat exchanger, is brought into heat exchange relationship with any strong solution which may have solidified in the strong solution line in the triple loop heat exchanger to thereby aid in desolidifying any such solidified strong solution.

Reimann, Robert C. (Lafayette, NY)

1984-01-01T23:59:59.000Z

202

THE ABSORPTION OF HYDROGEN ON LOW PRESSURE HYDRIDE MATERIALS  

DOE Green Energy (OSTI)

For this study, hydrogen getter materials (Zircaloy-4 and pure zirconium) that have a high affinity for hydrogen (and low overpressure) have been investigated to determine the hydrogen equilibrium pressure on Zircaloy-4 and pure zirconium. These materials, as with most getter materials, offered significant challenges to overcome given the low hydrogen equilibrium pressure for the temperature range of interest. Hydrogen-zirconium data exists for pure zirconium at 500 C and the corresponding hydrogen overpressure is roughly 0.01 torr. This manuscript presents the results of the equilibrium pressures for the absorption and desorption of hydrogen on zirconium materials at temperatures ranging from 400 C to 600 C. The equilibrium pressures in this temperature region range from 150 mtorr at 600 C to less than 0.1 mtorr at 400 C. It has been shown that the Zircaloy-4 and zirconium samples are extremely prone to surface oxidation prior to and during heating. This oxidation precludes the hydrogen uptake, and therefore samples must be heated under a minimum vacuum of 5 x 10{sup -6} torr. In addition, the Zircaloy-4 samples should be heated at a sufficiently low rate to maintain the system pressure below 0.5 mtorr since an increase in pressure above 0.5 mtorr could possibly hinder the H{sub 2} absorption kinetics due to surface contamination. The results of this study and the details of the testing protocol will be discussed.

Morgan, G.; Korinko, P.

2012-04-03T23:59:59.000Z

203

Lyman-alpha wing absorption in cool white dwarf stars  

E-Print Network (OSTI)

Kowalski & Saumon (2006) identified the missing absorption mechanism in the observed spectra of cool white dwarf stars as the Ly-alpha red wing formed by the collisions between atomic and molecular hydrogen and successfully explained entire spectra of many cool DA-type white dwarfs. Owing to the important astrophysical implications of this issue, we present here an independent assessment of the process. For this purpose, we compute free-free quasi-molecular absorption in Lyman-alpha due to collisions with H and H2 within the one-perturber, quasi-static approximation. Line cross-sections are obtained using theoretical molecular potentials to describe the interaction between the radiating atom and the perturber. The variation of the electric-dipole transition moment with the interparticle distance is also considered. Six and two allowed electric dipole transitions due to H-H and H-H2 collisions, respectively, are taken into account. The new theoretical Lyman-alpha line profiles are then incorporated in our ...

Rohrmann, R D; Kepler, S O

2010-01-01T23:59:59.000Z

204

Hydrogen Absorption in Pd-based Nanostructures - Final Report  

DOE Green Energy (OSTI)

Pd is known to absorb hydrogen. Molecules are normally chemisorbed at the surface in a process where the molecule breaks into two hydrogen atoms, and the protons are then absorbed into the bulk. This process consists of electron filling holes in the Pd 4d band near the Fermi energy, which due to the high density of states at the Fermi energy, is an energetically favorable process. Our aim with this project was to determine possible changes in magnetic properties with Pd nm-length-scale thick layers intercalated by magnetic materials. Before the start of this work, the literature indicated that there were several possible scenarios by which this could happen: i) the Pd will be magnetized due to a proximity effect with nearby magnetic layers, resulting in changes in the magnetization due to H2 absorption; ii) some H will be absorbed into the magnetic layers, causing a change in the magnetic exchange interactions; or iii) absorption of H2 will cause an expansion of the lattice, resulting in a magnetoelastic effect which changes the magnetic properties.

David Lederman

2012-10-22T23:59:59.000Z

205

Membrane-Based Absorption Refrigeration Systems: Nanoengineered Membrane-Based Absorption Cooling for Buildings Using Unconcentrated Solar & Waste Heat  

Science Conference Proceedings (OSTI)

BEETIT Project: UFL is improving a refrigeration system that uses low quality heat to provide the energy needed to drive cooling. This system, known as absorption refrigeration system (ARS), typically consists of large coils that transfer heat. Unfortunately, these large heat exchanger coils are responsible for bulkiness and high cost of ARS. UFL is using new materials as well as system design innovations to develop nanoengineered membranes to allow for enhanced heat exchange that reduces bulkiness. UFLs design allows for compact, cheaper and more reliable use of ARS that use solar or waste heat.

None

2010-09-01T23:59:59.000Z

206

Active Reflection Absorption for a Three Dimensional Multidirectional Wave Generator  

E-Print Network (OSTI)

In order to implement an accurate system that allows for absorption of reflected waves impinging to a wave maker (Active Reflection Absorption), it was required to apply a method to estimate properly the direction of arrival of the waves that does it in the fastest way possible. Our wavemaker control system has been prepared to handle an algorithm provided by Bosch-Rexroth where the wave angle estimation is practically locked to a very narrow frequency band (spatial gain-mixer). The system was evaluated with physical tests in a 3D wave basin for different conditions of reflected waves arriving with an angle to the wavemaker front, and acceptable performance has been found for the 3D ARA mode. However, for certain conditions over-compensation or sub-compensation can develop resulting in a poor absorption. This is mainly related to not being able to determine accurately the direction from which the reflected waves travel towards the wavemaker. The present work employed concepts found in the areas of antenna array signal processing and signal propagation, which were applied to this problem. This approach coupled naturally with our wavemaker system since it was prepared with 48 gages that can be employed in an array antenna fashion. A program was codified from an algorithm found in literature to calculate the Direction of Arrival (DOA) of the reflected waves. The focus for the testing of this program was with regular waves. The tests were conducted to validate the program with different angles of incidence and show that for regular waves the program was able to detect accurately the DOA of these in as few as 5 snapshots, with a minimum of 7 gages used as the antenna input. With data obtained directly from the control system of our wavemaker using regular waves, the program was able to determine the DOA. The computational burden of the algorithm is not significant in the case of regular waves. A modification of the program is required to analyze the DOA of reflected irregular waves, which could increase the computational burden. Actual implementation of this program to our control system depends on cooperation with Bosch-Rexroth.

Cruz Castro, Oscar

2009-08-01T23:59:59.000Z

207

CO2 Capture by Absorption with Potassium Carbonate  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. Ethylenediamine was detected in a degraded solution of MEA/PZ solution, suggesting that piperazine is subject to oxidation. Stripper modeling has demonstrated that vacuum strippers will be more energy efficient if constructed short and fat rather than tall and skinny. The matrix stripper has been identified as a configuration that will significantly reduce energy use. Extensive measurements of CO{sub 2} solubility in 7 m MEA at 40 and 60 C have confirmed the work by Jou and Mather. Corrosion of carbon steel without inhibitors increases from 19 to 181 mpy in lean solutions of 6.2 m MEA/PZ as piperazine increases from 0 to 3.1 m.

Gary T. Rochelle; Eric Chen; Babatunde Oyenekan; Andrew Sexton; Jason Davis; Marcus Hilliard; Amornvadee Veawab

2006-09-30T23:59:59.000Z

208

Optimum hot water temperature for absorption solar cooling  

SciTech Connect

The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

2009-10-15T23:59:59.000Z

209

Performance comparison of absorption and desiccant solar cooling systems  

DOE Green Energy (OSTI)

Cooling systems are required to operate over a wide range of outdoor and load conditions; however, the performance of solar cooling components is often specified and compared at a typical design point such as ARI conditions. A method is presented to directly compare the performance of different desiccant and absorption cooling systems by using psychrometric analysis of air distribution cycles under a range of outdoor conditions that systems encounter over a year. Using analysis of cooling load distributions for a small commercial office building in Miami and Phoenix a seasonal COP is calculated for each system. The heat input can be provided by solar or by an auxiliary heat source, such as natural gas.

Warren, M.L.; Wahlig, M.

1986-01-01T23:59:59.000Z

210

Light absorption cell combining variable path and length pump  

DOE Patents (OSTI)

This invention is comprised of a device for use in making spectrophotometric measurements of fluid samples. In particular, the device is a measurement cell containing a movable and a fixed lens with a sample of the fluid therebetween and through which light shines. The cell is connected to a source of light and a spectrophotometer via optic fibers. Movement of the lens varies the path length and also pumps the fluid into and out of the cell. Unidirectional inlet and exit valves cooperate with the movable lens to assure a one-way flow of fluid through the cell. A linear stepper motor controls the movement of the lens and cycles it from a first position closer to the fixed lens and a second position farther from the fixed lens, preferably at least 10 times per minute for a nearly continuous stream of absorption spectrum data.

Prather, W.S.

1992-12-31T23:59:59.000Z

211

CO2 Capture by Absorption with Potassium Carbonate  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. The pilot plant data have been reconciled using 17% inlet CO{sub 2}. A rate-based model demonstrates that the stripper is primarily controlled by liquid film mast transfer resistance, with kinetics at vacuum and diffusion of reactants and products at normal pressure. An additional major unknown ion, probably glyoxylate, has been observed in MEA degradation. Precipitation of gypsum may be a feasible approach to removing sulphate from amine solutions and providing for simultaneous removal of CO{sub 2} and SO{sub 2}. Corrosion of carbon steel in uninhibited MEA solution is increased by increased amine concentration, by addition of piperazine, and by greater CO{sub 2} loading.

Gary T. Rochelle; Eric Chen; Babatunde Oyenekan; Andrew Sexton; Jason Davis; Marcus Hilliard; Amorvadee Veawab

2006-07-28T23:59:59.000Z

212

X-ray absorption studies of battery materials  

SciTech Connect

X-ray absorption spectroscopy (XAS) is ideal for {ital in}{ital situ} studies of battery materials because both the probe and signal are penetrating x rays. The advantage of XAS being element specific permits investigation of the environment of a constituent element in a composite material. This makes it very powerful for studying electrode additives and corrosion of individual components of complex metal hydride alloys. The near edge part of the spectrum (XANES) provides information on oxidation state and site symmetry of the excited atom. This is particularly useful in study of corrosion and oxidation changes in cathode materials during charge/discharge cycle. Extended fine structure (EXAFS) gives structural information. Thus the technique provides both chemical and structural information. Since XAS probes only short range order, it can be applied to study of amorphous electrode materials and electrolytes. This paper discusses advantages and limitations of the method, as well as some experimental aspects.

McBreen, J.

1996-10-01T23:59:59.000Z

213

Comparative Global Warming Impacts of Electric Vapor-Compression and Direct-fired Absorption Equipment  

Science Conference Proceedings (OSTI)

This report compares the global warming impacts of electric vapor-compression and gas-fired absorption-cycle equipment for commercial cooling applications. Absorption chillers do not use ozone depleting refrigerants but substitution of alternative refrigerants in electrically driven vapor-compression cycle equipment also offers radically reduced or eliminated potential for stratospheric ozone depletion. Therefore, when comparing absorption-cycle and vapor-compression equipment, net global warming impacts...

1994-03-01T23:59:59.000Z

214

The spin-orbit interaction enhanced terahertz absorption in graphene around the K point  

Science Conference Proceedings (OSTI)

We present a quantitative analysis on the effect of the spin-orbit interaction in the optical absorption of @p-electrons in graphene. It has been shown that the optical absorption amplitude of graphene around the K point in the Brillouin zone has a node ... Keywords: 73.50.Mx, 78.66.-w, 81.05.Uw, Absorption, Graphene, Spin-orbit interaction

A. R. Wright; G. X. Wang; W. Xu; Z. Zeng; C. Zhang

2009-04-01T23:59:59.000Z

215

IR differential-absorption lidars for ecological monitoring of the environment  

Science Conference Proceedings (OSTI)

A review of studies on lidar sensing of the environment by the method of IR differential absorption is presented. The differential-absorption method is described and its various applications are considered. A comparison of this method with other methods of lidar sensing showed that a differential-absorption lidar successfully supplements a Raman lidar. The basic parameters are presented for IR lidars fabricated recently by various research groups. The outlook for the IR lidar sensing of the atmosphere is discussed. (review)

Vasil'ev, B I [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Mannoun, Oussama [Moscow Institute of Physics and Technology (State University), Dolgoprudnyi, Moscow Region (Russian Federation)

2006-09-30T23:59:59.000Z

216

Intersubband Absorption at 1.55 ?M In Aln/Gan Multi Quantum Wells ...  

Science Conference Proceedings (OSTI)

Intersubband Absorption at 1.55 ?M In Aln/Gan Multi Quantum Wells Grown at 770 C by Metal Organic Vapor Phase Epitaxy using Pulse Injection Method.

217

Design Method for Light Absorption Enhancement in Ultra-Thin Film ...  

Science Conference Proceedings (OSTI)

ultra-thin film organic solar cells (OSCs) to improve the light absorption. ... In the promising field of solar cells, organic solar cells (OSCs) are advantageous in its...

218

Energy Absorption of Novel Macro-Porous Three-phase Syntactic ...  

Science Conference Proceedings (OSTI)

Presentation Title, Energy Absorption of Novel Macro-Porous Three-phase ... and high-momentum impacts to critical infrastructure, it has become increasingly...

219

Operation Synopsis of Gas-Fired Double-Effect Absorption Chillers  

E-Print Network (OSTI)

Absorption refrigeration systems are one of the oldest systems available. The fundamentals of absorption refrigeration were formulated about 1777, and the first successful absorption machine was developed in 1850. The first U.S. patent for an absorption refrigeration system was issued in 1860. Absorption systems can use many different heat sources to produce the refrigeration effect: natural gas, steam, solar, and oil. While absorption systems were popular in the U.S. in the early part of the 20th century, their use declined in the mid twentieth century for several reasons: (1) increased reliability of vapor compression systems, (2) dropping electric prices (in real dollars), and (3) rapidly increasing gas prices. In recent years, there has been a resurgence of interest in absorption refrigeration and cooling. Natural gas prices have moderated while electric prices continue to rise. The reliability and performance of absorption systems have been substantially improved with new technology from Japan. This paper summarizes the results of the operation of three absorption systems located in the greater Dallas/Ft. Worth area.

Phillips, J.

1986-01-01T23:59:59.000Z

220

J-13: Effect of Co Substitution on Microwave Absorption of BaFe12O19  

Science Conference Proceedings (OSTI)

Presentation Title, J-13: Effect of Co Substitution on Microwave Absorption of ... Energy Harvesting and Cooling with Flexible and Light-Weight Organic...

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

L-6: Energy Absorption of Aluminum Foam-Filled Tubes under Quasi ...  

Science Conference Proceedings (OSTI)

In addition, the energy absorption of foamtube configuration was 4.5 times of ... Steel-Aluminium Composite Castings for High-Performance Die Cooling...

222

Absorption cooling in district heating network: Temperature difference examination in hot water circuit.  

E-Print Network (OSTI)

?? Absorption cooling system driven by district heating network is relized as a smart strategy in Sweden. During summer time when the heating demand is (more)

Yuwardi, Yuwardi

2013-01-01T23:59:59.000Z

223

The Study of Heat and Mass Transfer In The Generator For an Absorption Air Conditioning System.  

E-Print Network (OSTI)

??This thesis is aimed to study the heat and mass transfer performance of a generator for the absorption cooling system. Both aqueous lithium bromide (LiBr) (more)

Hsu, Yu-lien

2012-01-01T23:59:59.000Z

224

Simulation study for an absorption solar cooling system operated under Taiwan climate.  

E-Print Network (OSTI)

??In this thesis, solar energy is utilized as the driving energy for an absorption cooling system, and a TRNSYS computer code is employed to simulate (more)

Chiu, Yi-ying

2008-01-01T23:59:59.000Z

225

Diacylglycerol Oil, 2nd EditionChapter 2 Digestion and Absorption of Glycerides  

Science Conference Proceedings (OSTI)

Diacylglycerol Oil, 2nd Edition Chapter 2 Digestion and Absorption of Glycerides Food Science Health Nutrition Biochemistry eChapters Food Science & Technology Health - Nutrition - Biochemistry Press Dow

226

Polarization dependence of the absorption coefficient for an array of strained quantum wires  

Science Conference Proceedings (OSTI)

The polarization dependence of the absorption coefficient for compressively and tensilely strained quantum wires is investigated as a function of strain

Igor Vurgaftman; Jasprit Singh

1995-01-01T23:59:59.000Z

227

In situ X-ray absorption spectroscopy--A probe of cathode materials...  

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

2006 Authors Deb, Aniruddha, and Elton J. Cairns Journal Fluid Phase Equilibria Volume 241 Pagination 4-19 Keywords absorption-fine-structure, in situ electrochemistry,...

228

Relating Secondary Organic Aerosol Characteristics with Cloud Condensation Nuclei Activity  

E-Print Network (OSTI)

and absorb solar and terrestrial radiation, influence cloudand absorb solar and terrestrial radiation, influence cloudand absorption of solar and thermal radiation by aerosol

Tang, Xiaochen

2013-01-01T23:59:59.000Z

229

BNL | Aerosol Lifecycle IOP  

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

Program Program Aerosol Life Cycle IOP The primary objectives that make up the Aerosol Life Cycle IOP can be broken down into three categories: Scientific; Logistical; and GVAX preparation. Scientific Objectives The science goals are to conduct intensive aerosol observations in a region exposed to anthropogenic, biogenic, and marine emissions with atmospheric processing times depending on air mass trajectories and time of day. Take advantage of new instruments in the MAOS (e.g., SP2, HR-PTRMS, ACSM, Trace Gas Suite, PASS-3, Aethelometer, UHSAS). Within this broad umbrella are embedded three main foci: Aerosol light absorption: How does the aerosol mass absorption coefficient (absorption per unit mass of BC) vary with atmospheric processing? Do observations agree with a shell-core model?

230

Applications of Lagrangian Dispersion Modeling to the Analysis of Changes in the Specific Absorption of Elemental Carbon  

DOE Green Energy (OSTI)

We use a Lagrangian dispersion model driven by a mesoscale model with four-dimensional data assimilation to simulate the dispersion of elemental carbon (EC) over a region encompassing Mexico City and its surroundings, the study domain for the 2006 MAX-MEX experiment, which was a component of the MILAGRO campaign. The results are used to identify periods when biomass burning was likely to have had a significant impact on the concentrations of elemental carbon at two sites, T1 and T2, downwind of the city, and when emissions from the Mexico City Metropolitan Area (MCMA) were likely to have been more important. They are also used to estimate the median ages of EC affecting the specific absorption of light, aABS, at 870 nm as well as to identify periods when the urban plume from the MCMA was likely to have been advected over T1 and T2. Values of aABS at T1, the nearer of the two sites to Mexico City, were smaller at night and increased rapidly after mid-morning, peaking in the mid-afternoon. The behavior is attributed to the coating of aerosols with substances such as sulfate or organic carbon during daylight hours, but such coating appears to be limited or absent at night. Evidence for this is provided by scanning electron microscope images of aerosols collected at three sampling sites. During daylight hours the values of aABS did not increase with aerosol age for median ages in the range of 1-4 hours. There is some evidence for absorption increasing as aerosols were advected from T1 to T2 but the statistical significance of that result is not strong.

Doran, J. C.; Fast, Jerome D.; Barnard, James C.; Laskin, Alexander; Desyaterik, Yury; Gilles, Marry K.; Hopkins, Rebecca J.

2008-03-07T23:59:59.000Z

231

Oxygen production by molten alkali metal salts using multiple absorption-desorption cycles  

DOE Patents (OSTI)

A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs.

Cassano, Anthony A. (Allentown, PA)

1985-01-01T23:59:59.000Z

232

Oxygen production by molten alkali metal salts using multiple absorption-desorption cycles  

DOE Patents (OSTI)

A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs. 3 figs.

Cassano, A.A.

1985-07-02T23:59:59.000Z

233

Analysis of a commercial absorption-refrigeration water-ammonia (ARWA) cycle using Aspen Plus simulator  

Science Conference Proceedings (OSTI)

The Robur absorption-refrigeration-water-ammonia (ARWA) cycle is analyzed using Aspen Plus flowsheet simulator. The results are compared with experimental and some manufacturer data reported in the open literature. Among performance parameters analyzed ... Keywords: Aspen, COP, absorption, ammonia, refrigeration, simulation, water

N. A. Darwish; S. H. Al-Hashimi; A. S. Al-Mansoori

2008-08-01T23:59:59.000Z

234

Dynamic analysis and control of sieve tray gas absorption column using MATALB and SIMULINK  

Science Conference Proceedings (OSTI)

The present work highlights the powerful combination of SIMULINK/MATLAB software as an effective flowsheeting tool which was used to simulate steady state, open and closed loop dynamics of a sieve tray gas absorption column. A complete mathematical model, ... Keywords: Control, Dynamic modelling, Gas absorption, MATLAB, SIMULINK

Menwer Attarakih; Mazen Abu-Khader; Hans-JRg Bart

2013-02-01T23:59:59.000Z

235

The energy absorption problem of a brane-world black hole  

E-Print Network (OSTI)

We have studied the wave dynamics and the energy absorption problem for the scalar field as well as the brane-localized gravitational field in the background of a braneworld black hole. Comparing our results with the four-dimensional Schwarzschild black hole, we have observed the signature of the extra dimension in the energy absorption spectrum.

Lihui Liu; Bin Wang; Guohong Yang

2007-01-18T23:59:59.000Z

236

Use of Simulation To Optimize NOx Abatement by Absorption and Selective Catalytic Reduction  

E-Print Network (OSTI)

Use of Simulation To Optimize NOx Abatement by Absorption and Selective Catalytic Reduction Andrew the effect of the ammonia feed ratio on the NOx reduction efficiency for the SCR model. Optimal NOx removal NOx in an inert gas slows its absorption in the absorber and its reduction in the SCR because

Liu, Y. A.

237

Wave absorption at the second harmonic of the electron-cyclotron frequency in a tokamak plasma  

SciTech Connect

Wave absorption in the ISX-B tokamak (Phys. Rev. Lett. 44, 647 (1980)) at the second harmonic (..omega.. = 2..omega../sub c/e) of the electron-cyclotron frequency is reported. Measurements of the absorption of a wave polarized in the extraordinary mode and propagating perpendicular to the toroidal magnetic field are in agreement with computations.

McDermott, F.S.; Bekefi, G.; England, A.C.; Attenberger, S.E.; Batchelor, D.B.; Edmonds, P.H.; Goldfinger, R.C.; Kindsfather, R.R.; Lazarus, E.A.; Murakami, M.

1985-08-01T23:59:59.000Z

238

NH3- H2O absorption systems used for research and student activities  

Science Conference Proceedings (OSTI)

In the context of the sustainable development and of the future environment and energy concerns, a new laboratory was developed based on absorption systems (a chiller-heater and a heat pump). The installation together with the proposed experimental activity ... Keywords: absorption systems, education and research activity, environment, heat pump

Ioan Boian; Alexandru Serban; Stan Fota; Florea Chiriac

2009-10-01T23:59:59.000Z

239

All Green Residential Solar Energy to Heat Absorption Cooling / Heating Systems  

Science Conference Proceedings (OSTI)

An all-green residential solar to heat absorption cooling / heating system system is designed. It describes the components of the system and working principle, and analyze the prospects of the system and academic value. Finally, To Changsha, for example, ... Keywords: solar, ground-source heat pump, absorption, heat tube

Xu Feng

2013-01-01T23:59:59.000Z

240

Numerical investigations on the pressure wave absorption and the gas cooling interacting in a  

E-Print Network (OSTI)

1 Numerical investigations on the pressure wave absorption and the gas cooling interacting understanding of the physical phenomena involved, as for example the cooling and the shock wave absorption volume method, variable porosity, arc cooling I. INTRODUCTION Medium voltage cells have to be designed

Sart, Remi

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Control of absorption columns in the bioethanol process: Influence of measurement uncertainties  

Science Conference Proceedings (OSTI)

The alcohol lost by evaporation during the bioethanol fermentation process may be collected and recovered using an absorption column. This equipment is also used in the carbonic gas treatment, a by-product from the sugar cane fermentation. In the present ... Keywords: Absorption column, Artificial neural network control, Bioethanol, Concentration measurement uncertainty, Fermentation

Eduardo Eyng; Ana M. F. Fileti

2010-03-01T23:59:59.000Z

242

Toward a Minimal Representation of Aerosols in Climate Models: Comparative Decomposition of Aerosol Direct, Semidirect, and Indirect Radiative Forcing  

Science Conference Proceedings (OSTI)

The authors have decomposed the anthropogenic aerosol radiative forcing into direct contributions from each aerosol species to the planetary energy balance through absorption and scattering of solar radiation, indirect effects of anthropogenic ...

S. J. Ghan; X. Liu; R. C. Easter; R. Zaveri; P. J. Rasch; J.-H. Yoon; B. Eaton

2012-10-01T23:59:59.000Z

243

Modeling broadband X-ray absorption of massive star winds  

E-Print Network (OSTI)

We present a method for computing the net transmission of X-rays emitted by shock-heated plasma distributed throughout a partially optically thick stellar wind from a massive star. We find the transmission by an exact integration of the formal solution, assuming the emitting plasma and absorbing plasma are mixed at a constant mass ratio above some minimum radius, below which there is assumed to be no emission. This model is more realistic than either the slab absorption associated with a corona at the base of the wind or the exospheric approximation that assumes all observed X-rays are emitted without attenuation from above the radius of optical depth unity. Our model is implemented in XSPEC as a pre-calculated table that can be coupled to a user-defined table of the wavelength dependent wind opacity. We provide a default wind opacity model that is more representative of real wind opacities than the commonly used neutral ISM tabulation. Preliminary modeling of \\textit{Chandra} grating data indicates that the ...

Leutenegger, Maurice A; Zsarg, Janos; Martell, Erin M; MacArthur, James P; Owocki, Stanley P; Gagn, Marc; Hillier, D John

2010-01-01T23:59:59.000Z

244

ABSIM. Simulation of Absorption Systems in Flexible and Modular Form  

Science Conference Proceedings (OSTI)

The computer code has been developed for simulation of absorption systems at steady-state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system's components. When all the equations have been established, a mathematical solver routine is employed to solve them simultaneously. Property subroutines contained in a separate data base serve to provide thermodynamic properties of the working fluids. The code is user-oriented and requires a relatively simple input containing the given operating conditions and the working fluid at each state point. the user conveys to the computer an imagev of the cycle by specifying the different components and their interconnections. Based on this information, the program calculates the temperature, flowrate, concentration, pressure and vapor fraction at each state point in the system and the heat duty at each unit, from which the coefficient of performance may be determined. A graphical user-interface is provided to fcilitate interactive input and study of the output.

Grossman, G. (Israel Institute of Thechnology, Haifa, (Israel))

1994-06-01T23:59:59.000Z

245

ABSIM. Simulation of Absorption Systems in Flexible and Modular Form  

Science Conference Proceedings (OSTI)

The computer code has been developed for simulation of absorption systems at steady-state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system`s components. When all the equations have been established, a mathematical solver routine is employed to solve them simultaneously. Property subroutines contained in a separate data base serve to provide thermodynamic properties of the working fluids. The code is user-oriented and requires a relatively simple input containing the given operating conditions and the working fluid at each state point. the user conveys to the computer an image of the cycle by specifying the different components and their interconnections. Based on this information, the program calculates the temperature, flowrate, concentration, pressure and vapor fraction at each state point in the system and the heat duty at each unit, from which the coefficient of performance may be determined. A graphical user-interface is provided to facilitate interactive input and study of the output.

Grossman, G. [Israel Institute of Thechnology, Haifa, (Israel)

1994-06-01T23:59:59.000Z

246

Modelling Alkali Line Absorption and Molecular Bands in Cool DAZs  

E-Print Network (OSTI)

Two peculiar stars showing an apparent extremely broadened and strong NaI D absorption have been discovered in surveys for cool white dwarfs by Oppenheimer et al. (2001) and Harris et al. (SDSS, 2003). We discuss the nature of these objects using PHOENIX atmosphere models for metal-poor brown dwarfs/very low mass stars, and new white dwarf LTE and NLTE models for hydrogen- and helium-dominated atmospheres with metals. These include complete molecular formation in chemical equilibrium and a model for the alkali resonance line broadening based on the damping profiles of Allard et al. (2003), as well as new molecular line opacities for metal hydrides. First results of our calculations indicate good agreement with a hydrogen-dominated WD atmosphere with a Na abundance roughly consistent with a state of high accretion. We analyse deviations of the abundances of Na, K, Mg and Ca from the cosmic pattern and comment on implications of these results for standard accretion scenarios.

Derek Homeier; Nicole F. Allard; France Allard; Peter H. Hauschildt; Andreas Schweitzer; Phillip C. Stancil; Philippe F. Weck

2005-01-05T23:59:59.000Z

247

Gas-Fired Absorption Heat Pump Water Heater Research Project | Department  

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

Emerging Technologies » Gas-Fired Absorption Heat Pump Water Emerging Technologies » Gas-Fired Absorption Heat Pump Water Heater Research Project Gas-Fired Absorption Heat Pump Water Heater Research Project The U.S. Department of Energy (DOE) is currently conducting research into carbon gas-fired absorption heat pump water heaters. This project will employ innovative techniques to increase water heating energy efficiency over conventional gas storage water heaters by 40%. Project Description This project seeks to develop a natural gas-fired water heater using an absorption heat. The development effort is targeting lithium bromide aqueous solutions as a working fluid in order to avoid the negative implications of using more toxic ammonia. Project Partners Research is being undertaken through a Cooperative Research and Development

248

OPTIMUM ENERGY ABSORPTION OF A SHORT-PULSE LASER IN A DOPED DIELECTRIC SLAB  

SciTech Connect

A model is used to calculate energy absorption efficiency when a short-pulse laser impinges on a dielectric slab doped with an impurity for which the electrons have a resonant line at the laser wavelength. The amount of the energy resonant absorption is due to the overlapping between laser spectrum and resonance spectrum. The energy absorption efficiency can be maximized for a certain degree of doping concentration (at a given pulselength) and also for a certain pulselength (at a given doping concentration). For a modest amount of impurity, the resonant absorption may increase the fraction of energy absorption up to tens of percent of laser energy at 100s optical cycles when the laser wavelength is tuned within 1% of the resonant line. Dimensionless parameters are constructed so that the scaling to various parameters: laser wavelength, laser pulselength, dielectric constant, slab thickness, impurity concentration, resonant linewidth, and separation between the laser wavelength and the line resonance, could easily be obtained.

L. ANG

2001-05-01T23:59:59.000Z

249

Transient heat and mass transfer in a drop experiencing absorption with internal circulation  

SciTech Connect

Absorption of gas and vapor into moving liquid droplet is frequently encountered in numerous applications in chemical industries and refrigeration technology. Here, transient heat and mass transfer associated with a moving liquid drop during absorption was numerically studied in this work. The roles played by the internal circulation inside the droplet and the exothermic heat effect were demonstrated. The numerical results reveal that the significant absorption enhancement by internal circulation becomes negligible with the increase of exothermic absorption heat. The highly exothermic system of LiBr/H{sub 2}O, which is used as a typical refrigerant/absorbent combination in commercial absorption heat pump (AHP), was selected as an example to illustrate this point.

Lu, H.H.; Wu, T.C.; Yang, Y.M.; Maa, J.R. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering] [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering

1998-11-01T23:59:59.000Z

250

Isotope Enrichment Detection by Laser Ablation - Dual Tunable Diode Laser Absorption Spectrometry  

Science Conference Proceedings (OSTI)

The rapid global expansion of nuclear energy is motivating the expedited development of new safeguards technology to mitigate potential proliferation threats arising from monitoring gaps within the uranium enrichment process. Current onsite enrichment level monitoring methods are limited by poor sensitivity and accuracy performance. Offsite analysis has better performance, but this approach requires onsite hand sampling followed by time-consuming and costly post analysis. These limitations make it extremely difficult to implement comprehensive safeguards accounting measures that can effectively counter enrichment facility misuse. In addition, uranium enrichment by modern centrifugation leads to a significant proliferation threat, since the centrifuge cascades can quickly produce a significant quantity of highly enriched uranium (HEU). The Pacific Northwest National Laboratory is developing an engineered safeguards approach having continuous aerosol particulate collection and uranium isotope analysis to provide timely detection of HEU production in a low enriched uranium facility. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy, to characterize the 235U/238U isotopic ratio by subtle differences in atomic absorption wavelengths arising from differences in each isotopes nuclear mass, volume, and spin (hyperfine structure for 235U). Environmental sampling media is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes a 10 to 20-m sample diameter. The ejected plasma forms a plume of atomic vapor. A plume for a sample containing uranium has atoms of the 235U and 238U isotopes present. Tunable diode lasers are directed through the plume to selectively excite each isotope and their presence is detected by monitoring absorbance signals on a shot-to-shot basis. Single-shot detection sensitivity approaching the femtogram range and abundance uncertainty less than 10% have been demonstrated with measurements on surrogate materials. In this paper we present measurement results on samples containing background materials (e.g., dust, minerals, soils) laced with micron-sized target particles having isotopic ratios ranging from 1 to 50%.

Anheier, Norman C.; Bushaw, Bruce A.

2009-07-01T23:59:59.000Z

251

Design Considerations, Installation and Operation of the Two-Stage Parallel Flow Absorption Chiller  

E-Print Network (OSTI)

This presentation describes the actual design consideration and field operation experience of two-stage parallel flow absorption chillers. The applications include new construction, rehabilitation of old HVAC systems, cogeneration, and industrial process heat recovery. The high performance (COP = 1.14), and reduced maintenance cost of the two-stage parallel flow absorption chiller provides a notable improvement over the conventional single stage absorption chillers (COP = .6). The infamous reputation of the single stage absorption chiller for crystallization, poor mechanical performance, and general unreliability has been completely neutralized by new design concepts incorporated in the two-stage parallel flow absorption chiller/heater. The ease of maintenance and virtual elimination of crystallization has vastly improved chilled water production and mechanical longevity. The two-stage parallel flow absorption chiller is adaptable to various heat sources including direct fired multi-fuel, steam, exhaust, hot water, thermal fluids, etc. This makes this chiller a worthy consideration as an alternate to electrically driven refrigeration. The two-stage parallel flow absorption chiller has been operating in the United States since 1979 and there is presently over 24,000 tons of installed capacity online. Installations include office buildings, hospitals, computer centers, industrial process water and others.

Hufford, P. E.

1984-01-01T23:59:59.000Z

252

High-throughput liquid-absorption air-sampling apparatus and methods  

DOE Patents (OSTI)

A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is <10 cm of water, usually <5 cm of water. The sampler's collection efficiency is usually >20% for vapors or airborne particulates in the 2-3.mu. range and >50% for particles larger than 4.mu.. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives.

Zaromb, Solomon (95706 William Dr., Hinsdale, IL 60521)

2000-01-01T23:59:59.000Z

253

A New In Situ Laser Long-Path Absorption Instrument for the Measurement of Tropospheric OH Radicals  

Science Conference Proceedings (OSTI)

The authors describe a high-resolution long-path differential optical absorption spectrometer developed for the measurement of tropospheric hydroxyl radical concentrations. The instrument uses an atmospheric absorption light path of up to 3000-m ...

Hans-Peter Dorn; Uwe Brandenburger; Theo Brauers; Martin Hausmann

1995-10-01T23:59:59.000Z

254

The Use of New Parameterizations for Gaseous Absorption in the CLIRAD-SW Solar Radiation Code for Models  

Science Conference Proceedings (OSTI)

The new gaseous absorption parameterizations are incorporated in the CLIRAD-SW solar radiation code for models, openly distributed for the scientific community. In the new parameterizations, the magnitude of absorption coefficients in each ...

T. A. Tarasova; B. A. Fomin

2007-06-01T23:59:59.000Z

255

MOAS: An Absorption Laser Spectrometer for Sensitive and Local Monitoring of Tropospheric OH and Other Trace Gases  

Science Conference Proceedings (OSTI)

Hydroxyl radical (OH) multipass absorption spectroscopy (MOAS) is a laser optical method for the absolute and in situ monitoring of tropospheric OH with high spatial and temporal resolution. This technique is based on direct absorption ...

W. Armerding; M. Spiekermann; J. Walter; F. J. Comes

1995-10-01T23:59:59.000Z

256

Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma  

SciTech Connect

Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.

Xi Yanbin; Liu Yue [MOE Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2012-07-15T23:59:59.000Z

257

Broadband light absorption enhancement in polymer photovoltaics using metal nanowall gratings as transparent electrodes  

SciTech Connect

The authors investigate light absorption in organic solar cells in which indium tin oxide (ITO) is replaced by a new metallic architecture (grating) as a transparent electrode. Different from typical metal nanowire gratings, our gratings consist of metal nanowalls with nanoscale footprint and (sub)microscale height [Adv. Mater. 23, 2469 (2011)], thus ensuring high optical transmittance and electrical conductivity. Simulations reveal that a broadband and polarization-insensitive light absorption enhancement is achieved via two mechanisms, when such silver nanowall gratings are employed in P3HT:PCBM based solar cells. Overall absorption enhanced by ~23% compared to a reference cell with ITO electrode.

Ye, Zhuo; Chaudhary, Sumit; Kuang, Ping; Ho, Kai-Ming

2012-05-15T23:59:59.000Z

258

Transient radiation-induced absorption in the materials for a GSGG laser  

Science Conference Proceedings (OSTI)

Materials used in the optical elements of a 1,061 m GSGG (gadolinium scandium gallium garnet) laser have been tested for transient radiation-induced absorption. The transient radiation-induced absorption in KK1, Schott S7005 and S7010, and M382 glasses have been determined for discrete wavelengths in the range 440--750 nm. Also, the transient radiation-induced absorption in {open_quotes}pure{close_quotes} and MgO doped LiNbO{sub 3} has been measured at 1,061 nm. Mathematical expressions composed of exponentials are fitted to the data.

Brannon, P.J.

1993-11-01T23:59:59.000Z

259

Infrared Intracavity Laser Absorption Spectrometer , A. V. Muravjovb  

E-Print Network (OSTI)

Spectroscopy (ICLAS) at Mid-IR (MIR, 3-5 µm wavelengths), Long-Wave IR (LWIR, 8-12 µm wavelengths of vapors that will be simple, low-power, man portable, and composed of all off-the-shelf components aerosols, drugs, and banned or invasive plants or animals. Also, biomedical breath analysis and non

Peale, Robert E.

260

CO2 Capture by Absorption with Potassium Carbonate  

SciTech Connect

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. The best solvent and process configuration, matrix with MDEA/PZ, offers 22% and 15% energy savings over the baseline and improved baseline, respectively, with stripping and compression to 10 MPa. The energy requirement for stripping and compression to 10 MPa is about 20% of the power output from a 500 MW power plant with 90% CO{sub 2} removal. The stripper rate model shows that a ''short and fat'' stripper requires 7 to 15% less equivalent work than a ''tall and skinny'' one. The stripper model was validated with data obtained from pilot plant experiments at the University of Texas with 5m K{sup +}/2.5m PZ and 6.4m K{sup +}/1.6m PZ under normal pressure and vacuum conditions using Flexipac AQ Style 20 structured packing. Experiments with oxidative degradation at low gas rates confirm the effects of Cu{sup +2} catalysis; in MEA/PZ solutions more formate and acetate is produced in the presence of Cu{sup +2}. At 150 C, the half life of 30% MEA with 0.4 moles CO{sub 2}/mole amine is about 2 weeks. At 100 C, less than 3% degradation occurred in two weeks. The solubility of potassium sulfate in MEA solution increases significantly with CO{sub 2} loading and decreases with MEA concentration. The base case corrosion rate in 5 M MEA/1,2M PZ is 22 mpy. With 1 wt% heat stable salt, the corrosion rate increases by 50% to 160% in the order: thiosulfate< oxalate

Gary T. Rochelle; Eric Chen; Babatunde Oyenekan; Andrew Sexton; Jason Davis; Marus Hiilliard; Qing Xu; David Van Wagener; Jorge M. Plaza

2006-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

CO2 Capture by Absorption with Potassium Carbonate  

Science Conference Proceedings (OSTI)

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. The best K{sup +}/PZ solvent, 4.5 m K{sup +}/4.5 m PZ, requires equivalent work of 31.8 kJ/mole CO{sub 2} when used with a double matrix stripper and an intercooled absorber. The oxidative degradation of piperazine or organic acids is reduced significantly by inhibitor A, but the production of ethylenediamine is unaffected. The oxidative degradation of piperazine in 7 m MEA/2 m PZ is catalyzed by Cu{sup ++}. The thermal degradation of MEA becomes significant at 120 C. The solubility of potassium sulfate in MEA/PZ solvents is increased at greater CO{sub 2} loading. The best solvent and process configuration, matrix with MDEA/PZ, offers 22% and 15% energy savings over the baseline and improved baseline, respectively, with stripping and compression to 10 MPa. The energy requirement for stripping and compression to 10 MPa is about 20% of the power output from a 500 MW power plant with 90% CO{sub 2} removal. The stripper rate model shows that a ''short and fat'' stripper requires 7 to 15% less equivalent work than a ''tall and skinny'' one. The stripper model was validated with data obtained from pilot plant experiments at the University of Texas with 5m K{sup +}/2.5m PZ and 6.4m K{sup +}/1.6m PZ under normal pressure and vacuum conditions using Flexipac AQ Style 20 structured packing. Experiments with oxidative degradation at low gas rates confirm the effects of Cu{sup +2} catalysis; in MEA/PZ solutions more formate and acetate is produced in the presence of Cu{sup +2}. At 150 C, the half life of 30% MEA with 0.4 moles CO{sub 2}/mole amine is about 2 weeks. At 100 C, less than 3% degradation occurred in two weeks. The solubility of potassium sulfate in MEA solution increases significantly with CO{sub 2} loading and decreases with MEA concentration. The base case corrosion rate in 5 M MEA/1.2M PZ is 22 mpy. With 1 wt% heat stable salt, the corrosion rate increases by 50% to 160% in the order: thiosulfate< oxalate

Gary T. Rochelle; Andrew Sexton; Jason Davis; Marcus Hilliard; Qing Xu; David Van Wagener; Jorge M. Plaza

2007-03-31T23:59:59.000Z

262

Effect of adding flash tank on the evaporator's thermal load of the combined ejector-absorption cooling system  

Science Conference Proceedings (OSTI)

A modified combined absorption-ejector cooling system using aqua-ammonia (NH3-H2O) refrigerant has been investigated. Removable flash tank was added between the condenser and the evaporator. The modified cycle brings the advantage of improving in the ... Keywords: absorption system, combined absorption cooling system, ejectors, evaporators

Ranj Sirwan; Yusoff Ali; A. Zaharim; K. Sopian

2011-10-01T23:59:59.000Z

263

SIMULATION OF A SOLAR ABSORPTION COOLING SYSTEM J.P. Praene*, D. Morau, F. Lucas, F. Garde, H. Boyer  

E-Print Network (OSTI)

SIMULATION OF A SOLAR ABSORPTION COOLING SYSTEM J.P. Praene*, D. Morau, F. Lucas, F. Garde, H; accepted: 15 Oct 2007 This paper describes the dynamic modeling of a solar absorption cooling plant collector. A field of these collectors feed a single-effect absorption chiller of 35 kW nominal cooling

264

Nonlinear Effects of Coexisting Surface and Atmospheric Forcing of Anthropogenic Absorbing Aerosols: Impact on the South Asian Monsoon Onset  

Science Conference Proceedings (OSTI)

The direct radiative effect of absorbing aerosols consists of absorption-induced atmospheric heating together with scattering- and absorption-induced surface cooling. It is thus important to understand whether some of the reported climate impacts ...

Shao-Yi Lee; Ho-Jeong Shin; Chien Wang

2013-08-01T23:59:59.000Z

265

CO2 Absorption Rate and Solubility in Monoethanolamine/Piperazine/Water  

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

Absorption Rate and Solubility in Monoethanolamine/Piperazine/Water Absorption Rate and Solubility in Monoethanolamine/Piperazine/Water Hongyi Dang (dang@che.utexas.edu) Gary T. Rochelle* (gtr@che.utexas.edu, 512-471-7230) The University of Texas at Austin Department of Chemical Engineering Austin, Texas 78712 Prepared for presentation at the First National Conference on Carbon Sequestration, Washington, DC, May 14-17, 2001 ABSTRACT The solubility and absorption rate of carbon dioxide into monoethanolamine/ piperazine/water were measured in a wetted wall column at 40-60°C. The total amine concentration was varied from 1.0 M to 5.0 M with monoethanolamine blends containing 0 to 1.2 M piperazine. CO 2 solubility and solution speciation were simulated by nine equilibrium reactions. Two of the equilibrium constants were adjusted to match literature data. The rate of absorption was

266

Geek-Up[6.10.10]: Attosecond Absorption Spectroscopy and Kinked Nanopores |  

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

6.10.10]: Attosecond Absorption Spectroscopy and Kinked 6.10.10]: Attosecond Absorption Spectroscopy and Kinked Nanopores Geek-Up[6.10.10]: Attosecond Absorption Spectroscopy and Kinked Nanopores August 6, 2010 - 6:07pm Addthis A classical diagram of a krypton atom shows its 36 electrons arranged in shells. | Photo Courtesy of: Berkeley Lab. A classical diagram of a krypton atom shows its 36 electrons arranged in shells. | Photo Courtesy of: Berkeley Lab. Elizabeth Meckes Elizabeth Meckes Director of User Experience & Digital Technologies, Office of Public Affairs Thanks to the attosecond absorption spectroscopy process, an international team of scientists from Max Planck Institute of Quantum Optics (MPQ), Lawrence Berkeley National Laboratory and the University of California at Berkeley were able to observe an atom's electrons moving in real time -

267

Improvements in Shortwave Bulk Scattering and Absorption Models for the Remote Sensing of Ice Clouds  

Science Conference Proceedings (OSTI)

This study summarizes recent improvements in the development of bulk scattering/absorption models at solar wavelengths. The approach combines microphysical measurements from various field campaigns with single-scattering properties for nine habits ...

Bryan A. Baum; Ping Yang; Andrew J. Heymsfield; Carl G. Schmitt; Yu Xie; Aaron Bansemer; Yong-Xiang Hu; Zhibo Zhang

2011-05-01T23:59:59.000Z

268

High-frequency absorption of the dynamic mixed state in the surface superconductivity region  

SciTech Connect

We analyze the absorption of a high-frequency electromagnetic field in the type II superconductor Pb{sub 0.8}In{sub 0.2} in magnetic fields H{sub c2} < H < H{sub c3}. The absorption component proportional to the rate of variation of the external magnetic field is detected. We assume that this absorption component is associated with the dynamic mixed state of the superconducting shell containing 2D magnetic flux vortices (Kulik vortices). The motion of these vortices under the action of the critical current ensures the required difference between the external and internal magnetic inductions of the superconducting shell upon a change in the external magnetic field. This model correctly describes the observed behavior of absorption of rf electromagnetic radiation.

Berezin, V. A., E-mail: berezin@iptm.ru; Tulin, V. A., E-mail: tulin@iptm.ru [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)

2013-03-15T23:59:59.000Z

269

Observation of Water Vapor Greenhouse Absorption over the Gulf of Mexico Using Aircraft and Satellite Data  

Science Conference Proceedings (OSTI)

Through its interaction with radiation, water vapor provides an important link between the ocean and atmosphere. One way this occurs is through the greenhouse effect; observations of water vapor greenhouse absorption in the Gulf of Mexico during ...

David Marsden; Francisco P. J. Valero

2004-03-01T23:59:59.000Z

270

United States Department of Energy large commercial absorption chiller development program  

Science Conference Proceedings (OSTI)

The US Department of Energy (DOE) is working with partners from the gas cooling industry to improve energy efficiency and US competitiveness by using advanced absorption technologies that eliminate the use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), refrigerants that contribute to ozone depletion and global warming. Absorption cooling uses natural gas as the heat source, which produces much lower NO{sub x} emissions than oil- or coal-generated electricity. Gas-fired chillers also have the advantage of helping reduce peak electrical usage during summer months. To assist industry in developing advanced absorption cooling technologies, DOE sponsors the Large Commercial Chiller Development Program. The goal of the program is to improve chiller cooling efficiency by 30--50% compared with the best currently available absorption systems.

Garland, P.W.; DeVault, R.C.; Zaltash, A.

1998-11-01T23:59:59.000Z

271

Comparison of Daily Averaged Reflection, Transmission, and Absorption for Selected Radiative Flux Transfer Approximations  

Science Conference Proceedings (OSTI)

This paper compares accuracy for the daily averaged reflection, transmission, and absorption of solar flux derived from the delta-four-stream approximation and a few selected two-stream approximations. In the chosen variety of two-stream ...

Xun Zhu; Albert Arking

1994-12-01T23:59:59.000Z

272

Pressure Measurements Using an Airborne Differential Absorption Lidar. Part I: Analysis of the Systematic Error Sources  

Science Conference Proceedings (OSTI)

Systematic error sources that require correction when making remote airborne measurements of the atmospheric pressure field in the lower troposphere, using an oxygen differential absorption lidar, are analyzed. A detailed analysis of this ...

Cyrille N. Flamant; Geary K. Schwemmer; C. Laurence Korb; Keith D. Evans; Stephen P. Palm

1999-05-01T23:59:59.000Z

273

Land Surface Pressure Estimate from Measurements in the Oxygen A Absorption Band  

Science Conference Proceedings (OSTI)

The POLDER (polarization and directionality of the earth reflectances) instrument to be launched in 1996 carries two channels that cover the oxygen A absorption band (near IR). The authors investigate the possibility of using these measurements ...

Franois-Marie Bron; Sophie Bouffis

1996-01-01T23:59:59.000Z

274

Effect of Air Bubbles on Absorption of Solar Radiation by Water Droplets  

Science Conference Proceedings (OSTI)

It was suggested that absorption by a weakly absorbing droplet may be increased substantially by the presence of air bubbles within a droplet. The authors use an exact solution of the scattering of electromagnetic waves by a spherical particle ...

Petr Chlek; Gorden Videen; Dat Ngo

1998-02-01T23:59:59.000Z

275

Modification Research of Si3N4-SiC Heat Absorption Ceramic ...  

Science Conference Proceedings (OSTI)

Presentation Title, Modification Research of Si3N4-SiC Heat Absorption Ceramic Material Used for Tower Type Solar Thermal Power Plant. Author(s), Meng Liu,...

276

Photovoltaic device with increased light absorption and method for its manufacture  

DOE Patents (OSTI)

A photovoltaic cell having a light-directing optical element integrally formed in an encapsulant layer thereof. The optical element redirects light to increase the internal absorption of light incident on the photovoltaic device.

Glatfelter, Troy (Royal Oak, MI); Vogeli, Craig (New Baltimore, MI); Call, Jon (Royal Oak, MI); Hammond, Ginger (Imlay City, MI)

1993-07-20T23:59:59.000Z

277

The Absorption of Solar Radiation by Cloud Droplets: An Application of Anomalous Diffraction Theory  

Science Conference Proceedings (OSTI)

In this paper we demonstrate that the anomalous diffraction theory of van de Hulst with some modifications, provides a reasonable approximation of the volume extinction and absorption coefficients. We also show how the shortwave radiative ...

Steven A. Ackerman; Graeme L. Stephens

1987-06-01T23:59:59.000Z

278

Analysis of advanced conceptual designs for single-family-size absorption chillers  

DOE Green Energy (OSTI)

The objective of this research study is the development of radically new fluid systems, specifically tailored to the needs and requirements of solar-absorption cooling for single-family-size residences. Progress is reported.

Macriss, R.A.; Zawacki, T.S.; Kouo, M.T.; Sneed, D.M.

1978-01-01T23:59:59.000Z

279

Initial Field Measurements of Atmospheric Absorption at 911 ?m Wavelengths  

Science Conference Proceedings (OSTI)

A field adapted spectrophone system employing a tuneable CO2 laser source (over wavelengths 9.210.8 ?m) was used to measure atmospheric gaseous and particulate absorption at an isolated desert location in the southwestern United States. ...

C. W. Bruce; Y. P. Yee; B. D. Hinds; R. J. Brewer; J. Minjares; R. G. Pinnick

1980-08-01T23:59:59.000Z

280

Dynamic model for small-capacity ammonia-water absorption chiller .  

E-Print Network (OSTI)

??Optimization of the performance of absorption systems during transient operations such as start-up and shut-down is particularly important for small-capacity chillers and heat pumps to (more)

Viswanathan, Vinodh Kumar

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Computing the Atmospheric Absorption for the DMSP Operational Linescan System Infrared Channel  

Science Conference Proceedings (OSTI)

An accurate and rapid means is presented for computing the atmospheric absorption for the infrared channel (10.212.7 ?m) on the Defense Meteorological Satellite Program operational linescan system (OLS) for use in remote sensing studies of ...

Thomas J. Greenwald; Charles J. Drummond

1999-12-01T23:59:59.000Z

282

Interpolation and Profile Correction (IPC) Method for Shortwave Radiative Transfer in Spectral Intervals of Gaseous Absorption  

Science Conference Proceedings (OSTI)

The new interpolation and profile correction (IPC) method for radiance/flux calculations in gaseous absorption bands is presented. The IPC method is designed to allow an arbitrary spectral resolution including monochromatic mode. It features a ...

Alexei I. Lyapustin

2003-03-01T23:59:59.000Z

283

Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air  

E-Print Network (OSTI)

Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and ...

Scholten, Elke

284

An Atmospheric Soliton Observed with Doppler Radar, Differential Absorption Lidar, and a Molecular Doppler Lidar  

Science Conference Proceedings (OSTI)

Airborne Leandre II differential absorption lidar (DIAL), S-band dual-polarization Doppler radar (S-Pol), and Goddard Lidar Observatory for Winds (GLOW) Doppler lidar data are used, in conjunction with surface mesonet and special sounding data, ...

Steven E. Koch; Cyrille Flamant; James W. Wilson; Bruce M. Gentry; Brian D. Jamison

2008-08-01T23:59:59.000Z

285

Nutrition and Biochemistry of PhospholipidsChapter 7 Digestion and Absorption of Sphingolipids in Food  

Science Conference Proceedings (OSTI)

Nutrition and Biochemistry of Phospholipids Chapter 7 Digestion and Absorption of Sphingolipids in Food Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry AOCS Press 1B40289065CAC949E574965E9527473B AOCS P

286

High-Precision, High-Resolution Measurements of Absorption in the Oxygen A-Band  

Science Conference Proceedings (OSTI)

Issues arising in the application of high-resolution, high-precision spectroscopy to remote sensing are discussed in the context of deriving surface pressure from absorption in the O2 A-band. This application requires spectral resolution ...

D. M. OBrien; S. A. English; Grant Da Costa

1997-02-01T23:59:59.000Z

287

Measurement of Individual Hydrometeor Absorption Cross Sections Utilizing Microwave Cavity Perturbation Techniques  

Science Conference Proceedings (OSTI)

A technique for measurement of individual hydrometeor absorption cross sections is presented. Cross sections are inferred by inserting the hydrometeor into a high Q resonant cavity and measuring the Q perturbation. Tests were conducted in a 10.64 ...

Robert John Hansman Jr.

1984-12-01T23:59:59.000Z

288

UV Absorption Hygrometer for Fast-Response Airborne Water Vapor Measurements  

Science Conference Proceedings (OSTI)

A next-generation vacuum-ultraviolet (Lyman-alpha) absorption hygrometer for high-rate research aircraft humidity measurements designed by the National Center for Atmospheric Research is described. It retains the high data rate, optical and ...

Stuart P. Beaton; Mike Spowart

2012-09-01T23:59:59.000Z

289

Water Vapor Profiling Using a Widely Tunable, Amplified Diode-Laser-Based Differential Absorption Lidar (DIAL)  

Science Conference Proceedings (OSTI)

A differential absorption lidar (DIAL) instrument for automated profiling of water vapor in the lower troposphere has been designed, tested, and is in routine operation at Montana State University. The laser transmitter for the DIAL instrument ...

Amin R. Nehrir; Kevin S. Repasky; John L. Carlsten; Michael D. Obland; Joseph A. Shaw

2009-04-01T23:59:59.000Z

290

Ionic Liquids: Breakthrough Absorption Technology for Post-Combustion CO2 Capture  

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

Ionic Liquids: Breakthrough Absorption Ionic Liquids: Breakthrough Absorption Technology for Post-Combustion CO 2 Capture Background Development of innovative environmental control technologies is key to maintaining coal as an affordable and environmentally sound energy source. Carbon dioxide (CO 2 ) emissions control technologies, specifically post-combustion CO 2 capture, for coal- fired power plants is a major focus area in addressing climate change concerns. Post-

291

Testing of Crystallization Temperature of a New Working Fluid for Absorption Heat Pump Systems  

SciTech Connect

Lithium bromide/water (LiBr/water) absorption systems are potential candidates for absorption heat pump water heating applications since they have been widely commercialized for cooling applications. One drawback to LiBr/water absorption water heater systems is that they are unable to operate at typical water heating temperatures due to solution crystallization hazards. Binary or ternary mixtures, serving as working fluids, were reported (Ally, 1988; Herold et al., 1991; Iyoki and Uemura, 1981; Yasuhide Nemoto et al., 2010; Zogg et al., 2005) to help improve the absorption performance or avoid crystallization of absorption heat pump systems. A recent development (De Lucas et al., 2007) investigated the use of a ternary mixture of aqueous mixture of lithium bromide and sodium formate (CHO2Na). The new working fluid composition maintains a ratio of LiBr/CHO2Na of 2 by weight. This new working fluid is a potential competitor to aqueous LiBr solution in absorption system due to higher water vapor absorption rates and lower generation temperature needed (De Lucas et al., 2004). There exists data on equilibrium performance and other physical properties of this new working fluid. However, there is no available data on crystallization behavior. Crystallization temperature is crucial for the design of absorption heat pump water heater in order to avoid crystallization hazards during operation. We have therefore conducted a systematic study to explore the crystallization temperature of LiBr/CHO2Na water solution and compared it against aqueous LiBr solutions. These results were then used to evaluate the feasibility of using the new working fluid in water heating applications showing limited potential.

Wang, Kai [ORNL; Kisari, Padmaja [ORNL; Abdelaziz, Omar [ORNL; Vineyard, Edward Allan [ORNL

2010-01-01T23:59:59.000Z

292

Angular constraint on light-trapping absorption enhancement in solar cells  

E-Print Network (OSTI)

Light trapping for solar cells can reduce production cost and improve energy conversion efficiency. Understanding some of the basic theoretical constraints on light trapping is therefore of fundamental importance. Here, we develop a general angular constraint on the absorption enhancement in light trapping. We show that there is an upper limit for the angular integration of absorption enhancement factors. This limit is determined by the number of accessible resonances supported by an absorber.

Yu, Zongfu

2010-01-01T23:59:59.000Z

293

Method of determining pH by the alkaline absorption of carbon dioxide  

DOE Patents (OSTI)

A method for measuring the concentration of hydroxides in alkaline solutions in a remote location using the tendency of hydroxides to absorb carbon dioxide. The method includes the passing of carbon dioxide over the surface of an alkaline solution in a remote tank before and after measurements of the carbon dioxide solution. A comparison of the measurements yields the absorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to absorption fraction.

Hobbs, David T. (1867 Lodgepole Ave., N. Augusta, SC 29841)

1992-01-01T23:59:59.000Z

294

ON THE DIVERSITY AND COMPLEXITY OF ABSORPTION LINE PROFILES PRODUCED BY OUTFLOWS IN ACTIVE GALACTIC NUCLEI  

Science Conference Proceedings (OSTI)

Understanding the origin of active galactic nucleus (AGN) absorption line profiles and their diversity could help to explain the physical structure of the accretion flow, and also to assess the impact of accretion on the evolution of the AGN host galaxies. Here, we present our first attempt to systematically address the issue of the origin of the complexities observed in absorption profiles. Using a simple method, we compute absorption line profiles against a continuum point source for several simulations of accretion disk winds. We investigate the geometrical, ionization, and dynamical effects on the absorption line shapes. We find that significant complexity and diversity of the absorption line profile shapes can be produced by the non-monotonic distribution of the wind velocity, density, and ionization state. Non-monotonic distributions of such quantities are present even in steady-state, smooth disk winds, and naturally lead to the formation of multiple and detached absorption troughs. These results demonstrate that the part of a wind where an absorption line is formed is not representative of the entire wind. Thus, the information contained in the absorption line is incomplete if not even insufficient to well estimate gross properties of the wind such as the total mass and energy fluxes. In addition, the highly dynamical nature of certain portions of disk winds can have important effects on the estimates of the wind properties. For example, the mass outflow rates can be off by up to two orders of magnitude with respect to estimates based on a spherically symmetric, homogeneous, constant velocity wind.

Giustini, Margherita [INAF-Istituto di Astrofisica Spaziale e Fisica cosmica di Bologna, via Gobetti 101, I-40129 Bologna (Italy); Proga, Daniel [Department of Physics and Astronomy, University of Nevada Las Vegas, 4505 Maryland Pkwy, Las Vegas, NV 891541-4002 (United States)

2012-10-10T23:59:59.000Z

295

X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin  

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

X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films Title X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films Publication Type Journal Article LBNL Report Number LBNL-50574 Year of Publication 2002 Authors Richardson, Thomas J., Baker Farangis, Jonathan L. Slack, Ponnusamy Nachimuthu, Rupert C. C. Perera, Nobumichi Tamura, and Michael D. Rubin Journal Journal of Alloys and Compounds Volume 356-357 Start Page 204 Pagination 204-207 Date Published 08/2003 Keywords A. hydrogen storage materials, NEXAFS, thin film s; C. EXAFS, x-ray diffraction Abstract Mixed metal thin films containing magnesium and a first-row transition element exhibit very large changes in both reflectance and transmittance on exposure to hydrogen gas. Changes in electronic structure and coordination of the magnesium and transition metal atoms during hydrogen absorption were studied using dynamic in situ transmission mode X-ray absorption spectroscopy. Mg K-edge and Ni, Co, and Ti L-edge spectra reflect both reversible and irreversible changes in the metal environments. A significant shift in the nickel L absorption edge shows it to be an active participant in hydride formation. The effect on cobalt and titanium is much less dramatic, suggesting that these metals act primarily as catalysts for formation of magnesium hydride.

296

FUSE Observations of Interstellar and Intergalactic Absorption Toward the X-ray Bright BL Lac Object Mrk 421  

E-Print Network (OSTI)

High-quality Far-Ultraviolet Spectroscopic Explorer (FUSE) observations at 20 km /s resolution of interstellar and intergalactic absorption from 910 to 1187 A are presented for the X-ray bright BL Lac object Mrk 421. In this study we consider the O VI absorption between -140 to 165 km /s and its relationship to the lower ionization absorption and to the strong absorption produced by O VII and O VIII at X-ray wavelengths. The O VI absorption extending from -140 to 60 km /s is associated with strong low ionization gas absorption and originates in the Galactic thick disk / halo. This O VI appears to be produced by a combination of processes, including conductive interfaces between warm and hot gas and possibly cooling Galactic Fountain gas and hot halo gas bubbles. The O VI absorption extending from 60 to 165 km /s has unusual ionization properties in that there is very little associated low ionization absorption, with the exception of C III. This absorption is not observed toward two foreground halo stars, implying that it occurs in gas more distant than 3.5 kpc from the Galactic disk. Over the 60 to 165 km/s velocity range, O VI and C III absorption have the same kinematic behavior. N(O VI)/N(C III) = 10+/-3 over the 60 to 120 km/s velocity range. Given the association of O VI with C III, it is unlikely that the high velocity O VI co-exists with the hotter gas responsible for the O VII and O VIII absorption. The O VI positive velocity absorption wing might be tracing cooler gas entrained in a hot Galactic Fountain outflow. The O VII and O VIII absorption observed by Chandra and XMM-Newton may trace the hot gas in a highly extended (~100 kpc) Galactic corona or hot gas in the Local Group.

B. D. Savage; B. P. Wakker; A. J. Fox; K. R. Sembach

2004-12-15T23:59:59.000Z

297

Refractive index and absorption detector for liquid chromatography based on Fabry-Perot interferometry  

DOE Patents (OSTI)

A refractive index and absorption detector for liquid chromatography. It is based in part on a Fabry-Perot interferometer and is used for the improved detection of refractive index and absorption. It includes a Fabry-Perot interferometer having a normally fixed first partially reflecting mirror and a movable second partially reflecting mirror. A chromatographic flow-cell is positioned between the mirrors along the optical axis of a monochromatic laser beam passing through the interferometer. A means for deriving information about the interference fringes coming out of the interferometer is used with a mini-computer to compute the refractive index of the specimen injected into the flow cell. The minicomputer continuously scans the interferometer for continuous refractive index readings and outputs the continuous results of the scans on a chart recorder. The absorption of the specimen can concurrently be scanned by including a second optical path for an excitation laser which will not interfere with the first laser, but will affect the specimen so that absorption properties can be detected. By first scanning for the refractive index of the specimen, and then immediately adding the excitation laser and subsequently scanning for the refractive index again, the absorption of the specimen can be computed and recorded.

Yeung, Edward S. (Ames, IA); Woodruff, Steven D. (Ames, IA)

1984-06-19T23:59:59.000Z

298

Refractive index and absorption detector for liquid chromatography based on Fabry-Perot interferometry  

DOE Patents (OSTI)

A refractive index and absorption detector are disclosed for liquid chromatography. It is based in part on a Fabry-Perot interferometer and is used for the improved detection of refractive index and absorption. It includes a Fabry-Perot interferometer having a normally fixed first partially reflecting mirror and a movable second partially reflecting mirror. A chromatographic flow-cell is positioned between the mirrors along the optical axis of a monochromatic laser beam passing through the interferometer. A means for deriving information about the interference fringes coming out of the interferometer is used with a mini-computer to compute the refractive index of the specimen injected into the flow cell. The minicomputer continuously scans the interferometer for continuous refractive index readings and outputs the continuous results of the scans on a chart recorder. The absorption of the specimen can concurrently be scanned by including a second optical path for an excitation laser which will not interfere with the first laser, but will affect the specimen so that absorption properties can be detected. By first scanning for the refractive index of the specimen, and then immediately adding the excitation laser and subsequently scanning for the refractive index again, the absorption of the specimen can be computed and recorded. 10 figs.

Yeung, E.S.; Woodruff, S.D.

1984-06-19T23:59:59.000Z

299

Water-lithium bromide double-effect absorption cooling analysis. Final report  

DOE Green Energy (OSTI)

This investigation involved the development of a numerical model for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine, and the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy. The dynamic model should be valuable as a design tool for developing new absorption machines or modifying current machines to make them optimal based on current and future energy costs.

Vliet, G.C.; Lawson, M.B.; Lithgow, R.A.

1980-12-01T23:59:59.000Z

300

Performance characteristics and modeling of carbon dioxide absorption by amines in a packed column  

Science Conference Proceedings (OSTI)

Carbon dioxide (CO[sub 2]) is widely recognized as a major greenhouse gas contributing to global warming. To mitigate the global warming problem, removal of CO[sub 2] from the industrial flue gases is necessary. Absorption of carbon dioxide by amines in a packed column was experimentally investigated. The amines employed in the present study were the primary mono-ethanolamine (MEA) and tertiary N-methyldiethanolamine (MDEA), two very popular amines widely used in the industries for gas purification. The CO[sub 2] absorption characteristics by these two amines were experimentally examined under various operating conditions. A theoretical model was developed for describing the CO[sub 2] absorption behavior. Test data have revealed that the model predictions and the observed CO[sub 2] absorption breakthrough curves agree very well, validating the proposed model. Preliminary regeneration tests of exhausted amine solution were also conducted. The results indicated that the tertiary amine is easier to regenerate with less loss of absorption capacity than the primary one.

Lin, S.H.; Shyu, C.T. (Yuan Ze Univ., Taoyuan (Taiwan, Province of China). Dept. of Chemical Engineering)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen  

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

Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen in an Ionic Liquid Speaker(s): John Prausnitz Waheed Afzal Date: September 18, 2012 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Robert Hart Because of its low thermal conductivity, krypton is a useful gas for the vapor space of double- (or triple-) pane windows. However krypton is more expensive than argon, currently used for most of multi-pane windows. The high price of krypton is due to the energy-intensive cryogenic process for its recovery from oxygen that is obtained from air. Ionic liquids may provide a cost-effective absorption process for separation of krypton from the oxygen stream of a liquid-air plant. The polarizability of krypton is higher than that of oxygen; therefore, krypton solubility may be

302

Heating of solar chromosphere by electromagnetic wave absorption in a plasma slab model  

E-Print Network (OSTI)

The heating of chromospheric inter-network regions by means of the absorption of electromagnetic (EM) waves that originate from the photospheric blackbody radiation is studied in the framework of a plasma slab model. The absorption is provided by the electron-neutral collisions. Given the uncertain nature of the collision cross-section due to the plasma micro-turbulence, it is shown that for plausible physical parameters, the heating flux produced by the absorption of EM waves in the chromosphere is between $20 - 45$ % of the chromospheric radiative loss flux requirement. It is also established that there is an optimal value for the collision cross-section, $5 \\times 10^{-18}$ m$^{2}$, that produces the maximal heating flux of 1990 W m$^{-2}$.

Tsiklauri, David

2010-01-01T23:59:59.000Z

303

Dynamic performance testing of prototype 3 ton air-cooled carrier absorption chiller  

SciTech Connect

The performance of a prototype 3 ton cooling capacity air-cooled lithium bromide/water absorption chiller was tested using an absorption chiller test facility which was modified to expand its testing capabilities to include air-cooled chillers in addition to water-cooled chillers. Temperatures of the three externally supplied fluid loops: hot water, chilled water, and cooling air, were varied in order to determine the effects this would have on the two principal measures of chiller performance: cooling capacity and thermal coefficient of performance (COP). A number of interrelated factors were identified as contributing to less than expected performance. For comparison, experimental correlations of other investigators for this and other similar absorption chillers are presented. These have been plotted as both contour and three-dimensional performance maps in order to more clearly show the functional dependence of the chiller performance on the fluid loop temperatures.

Borst, R.R.; Wood, B.D.

1985-05-01T23:59:59.000Z

304

Use of an open-cycle absorption system for heating and cooling  

DOE Green Energy (OSTI)

Solar cooling for commercial applications using open-cycle absorption refrigeration systems has been investigated and found to be feasible. If an open-cycle absorption system can be operated as a chemical heat pump for winter heating operation, the system would offer year-round operation that could make the system economically viable for many regions of the US. An analysis of heating operation for the open-cycle system is presented using a computer program that simulates heat and mass transfer processes for any environmental condition. The open-cycle absorption refrigeration system can be operated as a chemical heat pump. Simulations for winter heating operation were run for five US cities, with solar COP's in the range of .06 to .16. At these levels, the OCAR system can provide full heating and cooling operation for office buildings in many southern US cities.

Schlepp, D. R.; Collier, R. K.

1981-03-01T23:59:59.000Z

305

LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery  

SciTech Connect

This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

Ko, Suk M. (Huntsville, AL)

1980-01-01T23:59:59.000Z

306

Investigation of Ion Absorption of the High Harmonic Fast Wave in NSTX using HPRT  

DOE Green Energy (OSTI)

Understanding high harmonic fast wave (HHFW) power absorption by ions in a spherical torus (ST) is of critical importance to assessing the wave's viability as a means of heating and especially driving current. In this work, the HPRT code is used to calculate absorption for helium and deuterium, with and without minority hydrogen in National Spherical Torus Experiment (NSTX) plasmas using experimental EFIT code equilibria and kinetic profiles. HPRT is a two-dimensional ray-tracing code which uses the full hot plasma dielectric to compute the perpendicular wave number along the hot electron and cold ion plasma ray path. Ion and electron absorption dependence on antenna phasing, ion temperature, beta (subscript t), and minority temperature and concentration is analyzed. These results form the basis for comparisons with other codes, such as CURRAY, METS, TORIC, and AORSA.

Rosenberg, A.; Menard, J.E.; and LeBlanc, B.P.

2001-05-18T23:59:59.000Z

307

Absorption spectroscopy in hollow-glass waveguides using infrared laser diodes  

Science Conference Proceedings (OSTI)

Hollow-glass waveguides may be a viable technology that, in some cases, may supplant heavier multi-pass cells such as White or Herriott cells for performing trace detection using tunable diode laser absorption spectroscopy. We report here a series of experiments for testing the suitability of waveguides for infrared spectroscopy. The loss characteristics of 1 mm bore diameter waveguides have been measured for straight and coiled lengths. Using direct absorption spectroscopy we have found that the absorption pathlength is approximately equal to the physical length of the waveguide. Broadband FM diode laser spectroscopy produces a comparable signal-to-noise ratio with less than a second of signal averaging. Finally, we have also performed near-infrared spectroscopy of nitrous oxide flowing through a waveguide using a telecommunications diode laser.

Blake, Thomas A.; Kelly, James F.; Stewart, Timothy L.; Hartman, John S.; Sharpe, Steven W.; Sams, Robert L.

2002-07-10T23:59:59.000Z

308

Collisionless absorption of light waves incident on overdense plasmas with steep density gradients  

Science Conference Proceedings (OSTI)

Collisionless absorption of laser light incident on overdense plasmas with steep density gradients is studied analytically and numerically. For the normal incidence case, it is shown that both sheath inverse bremsstrahlung and the anomalous skin effect are limiting cases of the same collisionless absorption mechanism. Using particle-in-cell (PIC) plasma simulations, the effects of finite sheath-transit time and finite density gradient are investigated. The analyses are extended to oblique incident cases. For p-polarized obliquely incident light, the results are significantly different from those for the normal incidence case. Most noticeable is the absorption enhancement for the p-polarized light due to the interaction of the electrons with the normal (parallel to the density gradient) component of the laser electric field in the sheath region.

Yang, T.Y.B.; Kruer, W.L.; Langdon, A.B.

1995-07-31T23:59:59.000Z

309

Heat and mass transfer in a falling film absorber of ammonia-water absorption systems  

SciTech Connect

For ammonia-water generator-absorber heat exchanger (GAX) systems to work at high coefficient of performance, the heat and mass transfer components have to operate at optimum performance within a narrow range of conditions for the recovery of internal energy. In the present work, an analysis is performed to study the absorption process of an ammonia-water vapor mixture by an aqueous solution of ammonia in a falling film absorber. The combined heat and mass transfer processes involved are analyzed through an integral formulation of the continuity, momentum, energy, and diffusion equations. The effects of vapor flow direction relative to the solution, cooling ability, ammonia concentration of solution and vapor, and interfacial momentum and heat transfer rate on absorption processes are investigated. The characteristics of the absorption process are found to be governed by the relative significance of the mass transfer resistance and the driving forces between the solution film and the vapor mixture.

Kim, B. [Hongik Univ., Seoul (Korea, Republic of). Dept. of Mechanical Engineering

1998-07-01T23:59:59.000Z

310

High-resolution absorption spectroscopy of the circumgalactic medium of the Milky Way  

E-Print Network (OSTI)

In this article we discuss the importance of high-resolution absorption spectroscopy for our understanding of the distribution and physical nature of the gaseous circumgalactic medium (CGM) that surrounds the Milky Way. Observational and theoretical studies indicate a high complexity of the gas kinematics and an extreme multi-phase nature of the CGM in low-redshift galaxies. High-precision absorption-line measurements of the Milky Way's gas environment thus are essential to explore fundamental parameters of circumgalactic gas in the local Universe, such as mass, chemical composition, and spatial distribution. We shortly review important characteristics of the Milky Way's CGM and discuss recent results from our multi-wavelength observations of the Magellanic Stream. Finally, we discuss the potential of studying the warm-hot phase of the Milky Way's CGM by searching for extremely weak [FeX] l6374.5 and [FeIVX] l5302.9 absorption in optical QSO spectra.

Richter, P; Bekhti, N Ben; Murphy, M T; Bomans, D; Frank, S

2013-01-01T23:59:59.000Z

311

On Absorption by Circumstellar Dust, With the Progenitor of SN2012aw as a Case Study  

E-Print Network (OSTI)

We use the progenitor of SN2012aw to illustrate the consequences of modeling circumstellar dust using Galactic (interstellar) extinction laws that (1) ignore dust emission in the near-IR and beyond; (2) average over dust compositions, and (3) mis-characterize the optical/UV absorption by assuming that scattered photons are lost to the observer. The primary consequences for the progenitor of SN2012aw are that both the luminosity and the absorption are significantly over-estimated. In particular, the stellar luminosity is most likely in the range 10^4.8 0.3 micron) and total (absorption plus scattering) V-band optical depth (tau < 20). These do not include the contributions of dust emission, but provide a simple, physical alternative to incorrectly using interstellar extinction laws.

Kochanek, C S; Dai, X

2012-01-01T23:59:59.000Z

312

Ab-initio calculations of the hydrogen-uranium system. Part I: Surface phenomena, absorption, transport and trapping  

DOE Green Energy (OSTI)

Density functional theory was applied to the initial steps of uranium hydriding: surface phenomena, absorption, bulk transport and trapping. H adsorbs exothermically to the (0 0 1) surface, yet H absorption into the bulk is endothermic, with off-center octahedral absorption having the lowest absorption energy of 0.39 eV, relative to molecular H{sub 2}. H absorption in interstitial sites causes a local softening of the bulk modulus. Diffusion of H in unstrained {alpha}-U has a barrier of 0.6 eV. The energy of H absorption adjacent to the chemical impurities C, S, Si was lowered by an amount proportional to the size of the impurity atom, and the resulting lattice strain Si > S > C. Thus, impurities may promote hydriding by providing surfaces or prestrained zones for H uptake.

Taylor, Christopher D [Los Alamos National Laboratory; Lillard, R Scott [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

313

Study of photoinduced absorption by the method of modified laser photothermal radiometry  

SciTech Connect

The application of the method of modified laser photothermal radiometry for studying the photoinduced absorption in thin films is considered. The sensitivity of the method is estimated. The mechanism of induced near-IR absorption in titanium dioxide films is proposed and the nature of surface defects responsible for this process is explained. It is shown that kinetic equations describing monomolecular recombination are consistent with the experimental dependences for the thermal activation energy of defects equal to 0.17{+-}0.04 eV. (laser applications and other topics in quantum electronics)

Skvortsov, L A; Maksimov, E M; Tuchkov, A A [Academy of Cryptography, Communication and Informatics, Moscow (Russian Federation)

2008-10-31T23:59:59.000Z

314

Two-dimensional disorder for broadband, omnidirectional and polarization-insensitive absorption  

E-Print Network (OSTI)

The surface of thin-film solar cells can be tailored with photonic nanostructures to allow light trapping in the absorbing medium. This in turn increases the optical thickness of the film and thus enhances their absorption. Such a coherent light trapping is generally accomplished with deterministic photonic architectures. Here, we experimentally explore the use of a different nanostructure, a disordered one, for this purpose. We show that the disorder-induced modes in the film allow improvements in the absorption over a broad range of frequencies and impinging angles.

Burresi, Matteo; Vynck, Kevin; Prasciolu, Mauro; Tormen, Massimo; Wiersma, Diederik S

2012-01-01T23:59:59.000Z

315

Resonant absorption of a short-pulse laser in a doped dielectric  

SciTech Connect

A simple model is used to calculate the energy absorption efficiency when a laser of short pulse length impinges on a dielectric slab that is doped with an impurity with a resonant line at the laser frequency. It is found that the energy absorption efficiency is maximized for a certain degree of doping concentration (at a given pulse length) and also for a certain pulselength (at a given doping concentration). Dimensionless parameters are constructed, allowing calculations with one set of parameters be used to infer the results expected for other sets of parameters. {copyright} {ital 1999 American Institute of Physics.}

Ang, L.K.; Lau, Y.Y.; Gilgenbach, R.M. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2104 (United States)

1999-05-01T23:59:59.000Z

316

Ultra-sensitive surface absorption spectroscopy using sub-wavelength diameter optical fibers  

E-Print Network (OSTI)

The guided modes of sub-wavelength diameter air-clad optical fibers exhibit a pronounced evanescent field. The absorption of particles on the fiber surface is therefore readily detected via the fiber transmission. We show that the resulting absorption for a given surface coverage can be orders of magnitude higher than for conventional surface spectroscopy. As a demonstration, we present measurements on sub-monolayers of 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) molecules at ambient conditions, revealing the agglomeration dynamics on a second to minutes timescale.

F. Warken; E. Vetsch; D. Meschede; M. Sokolowski; A. Rauschenbeutel

2007-01-12T23:59:59.000Z

317

Method of determining pH by the alkaline absorption of carbon dioxide  

DOE Patents (OSTI)

A method is described for measuring the concentration of hydroxides in alkaline solutions in a remote location using the tendency of hydroxides to absorb carbon dioxide. The method includes the passing of carbon dioxide over the surface of an alkaline solution in a remote tank before and after measurements of the carbon dioxide solution. A comparison of the measurements yields the absorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to absorption fraction. 2 figs.

Hobbs, D.T.

1992-10-06T23:59:59.000Z

318

Atomic hydrogen density measurements in an ion source plasma using a vacuum ultraviolet absorption spectrometer  

DOE Green Energy (OSTI)

A system to determine the density and temperature of ground state hydrogen atoms in a plasma by vacuum ultraviolet laser absorption spectroscopy is described. The continuous tunability of the spectrometer allows for analysis at any of the Lyman transitions. The narrow bandwidth of the laser system allows for the accurate determination of the absorption lineshape and hence the translational temperature. The utility of the system is exemplified by data obtained on an ion-source plasma. The measurements demonstrate the quality of the data as well as illustrating the behavior of this ion source under varying discharge conditions. 9 refs., 5 figs., 1 tab.

Stutzin, G.C.; Young, A.T.; Schlachter, A.S.; Stearns, J.W.; Leung, K.N.; Kunkel, W.B.; Worth, G.T.; Stevens, R.R.

1989-01-01T23:59:59.000Z

319

Speed and Temperature Effects in the Energy Absorption of Axially Crushed Composite Tubes  

E-Print Network (OSTI)

Time-Temperature Superposition 237 8.3.1 Thermally Activated Processes 237 8.3.2 Application to Tube Crushing 238 8.4 Crush Mode 241 8.4.1 Crush Zone Micrographs 241 8.4.2 Frond:Buckling Transition 254 8.4.3 Speed Sensitivity of the Crush Mode 256 8... -copy note i Abstract ii Contents v Symbols viii Superscript x Subscripts x Brackets xi Acknowledgements xii 1 Introduction 1 1.1 Impact Energy Absorption 1 1.2 Current Methods 2 1.3 Composite Materials 2 1.4 Calculation of Specific Energy Absorption 3 2...

Fontana, Quentin, P V

1990-06-05T23:59:59.000Z

320

Initial evolution of supports of solutions of quasilinear parabolic equations with degenerate absorption potential  

SciTech Connect

The propagation of supports of solutions of second-order quasilinear parabolic equations is studied; the equations are of the type of nonstationary diffusion, having semilinear absorption with an absorption potential which degenerates on the initial plane. We find sufficient conditions, which are sharp in a certain sense, on the relationship between the boundary regime and the type of degeneration of the potential to ensure the strong localization of solutions. We also establish a weak localization of solutions for an arbitrary potential which degenerates only on the initial plane. Bibliography: 12 titles.

Stepanova, Ekaterina V; Shishkov, Andrey E

2013-03-31T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Quantum dynamics of an optical cavity coupled to a thin semitransparent membrane: Effect of membrane absorption  

Science Conference Proceedings (OSTI)

We study the quantum dynamics of the cavity optomechanical system formed by a Fabry-Perot cavity with a thin vibrating membrane at its center. We determine in particular to what extent optical absorption by the membrane hinders reaching a quantum regime for the cavity-membrane system. We show that even though membrane absorption may significantly lower the cavity finesse and also heat the membrane, one can still simultaneously achieve ground state cooling of a vibrational mode of the membrane and stationary optomechanical entanglement with state-of-the-art apparatuses.

Biancofiore, C.; Karuza, M.; Galassi, M.; Natali, R.; Vitali, D. [School of Science and Technology, Physics Division, University of Camerino, via Madonna delle Carceri, 9, I-62032 Camerino (Italy) and INFN, Sezione di Perugia (Italy); Tombesi, P.; Di Giuseppe, G. [School of Science and Technology, Physics Division, University of Camerino, via Madonna delle Carceri, 9, I-62032 Camerino (Italy) and INFN, Sezione di Perugia (Italy); CriptoCam S.r.l., via Madonna delle Carceri 9, I-62032 Camerino (Italy)

2011-09-15T23:59:59.000Z

322

Transient radiation-induced absorption in materials for the DOI laser  

Science Conference Proceedings (OSTI)

This is the final report on a series of experiments concerned with transient radiation-induced absorption in materials for a Cr,Nd:GSGG laser. Both the Sandia National Laboratories SPR III pulsed reactor and the Hermes III pulsed X-ray machine are used as radiation sources. The time dependence and the magnitude of the induced absorption in filter glasses and in doped and undoped LiNbO{sub 3} Q-switch materials have been measured. Gain has been observed in Cr,Nd:GSGG, the laser medium, when it is irradiated by X-rays.

Brannon, P.J.

1995-01-01T23:59:59.000Z

323

L- and M-shell absorption measurements of radiatively heated Fe plasma  

SciTech Connect

Measurements of iron-plasma absorption spectrum over 150-1200 eV photon energy range were reported at temperature T = (72 {+-} 4) eV. The electron temperature was diagnosed with the absorption spectrum of aluminum mixed with iron. The density was not diagnosed directly but obtained from a radiative hydrodynamic simulation with the Multi-1D code. The broad photon energy range enables simultaneous observation of the L-shell and M-shell transitions that dominate the radiation transport at this temperature. The spectrally resolved transmission data were compared to the detailed-configuration-accounting model calculations and reasonable agreement was found.

Zhang Jiyan; Li Hang; Zhao Yang; Xiong Gang; Yuan Zheng; Zhang Haiying; Yang Guohong; Yang Jiamin; Liu Shenye; Jiang Shaoen; Ding Yongkun; Zhang Baohan; Zheng Zhijian [Research Center of Laser Fusion, P. O. Box 919-986, Mianyang 621900 (China); Xu Yan; Meng Xujun; Yan Jun [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

2012-11-15T23:59:59.000Z

324

Investigation of the principle of flame rectification in order to improve detection of the propane flame in absorption refrigerators.  

E-Print Network (OSTI)

?? Electrical properties of a propane flame was investigated to improve detection of the flame in absorption refrigerators. The principle of flame rectification, which uses (more)

Mllberg, Andreas

2005-01-01T23:59:59.000Z

325

PERFORMANCE OF AN EXPERIMENTAL SOLAR-DRIVEN ABSORPTION AIR CONDITIONER--ANNUAL REPORT JULY 1975-SEPT. 1976  

E-Print Network (OSTI)

cooled, ammonia-water absorption chiller as a starting pointabsorption cycle under such conJitions. A nominal three-ton,continuous operation, heat-actuated water chiller

Dao, K.

2010-01-01T23:59:59.000Z

326

The Effect of the Water Vapor and Carbon Dioxide on the Radiation Absorption and Temperature Profile in Troposphere.  

E-Print Network (OSTI)

??The work on this paper focus on the effect of the water vapor and carbon dioxide on the absorption of atmospheric radiation and the temperature (more)

Li, Chieh

2013-01-01T23:59:59.000Z

327

The evaluation of a solar-driven aqua-ammonia diffusion absorption heating and cooling cycle / M.C. Potgieter.  

E-Print Network (OSTI)

??Several steps are followed in order to evaluate the cycle as the title suggests. The diffusion absorption refrigerator (DAR) cycle performance is evaluated when using (more)

Potgieter, Marthinus Christiaan

2013-01-01T23:59:59.000Z

328

Absorptive capacity configurations in supply chains: gearing for partner-enabled market knowledge creation  

Science Conference Proceedings (OSTI)

The need for continual value innovation is driving supply chains to evolve from a pure transactional focus to leveraging interorganizational partner ships for sharing information and, ultimately, market knowledge creation. Supply chain partners are (1) ... Keywords: absorptive capacity, configuration approaches, interorganizational information systems, knowledge management, process modularity, rich information, supply chain

Arvind Malhotra; Sanjay Gosain; Omar Sawy

2005-03-01T23:59:59.000Z

329

Quantification of rapid environmental redox processes with quick-scanning x-ray absorption  

E-Print Network (OSTI)

manganese oxide x-ray absorption near-edge structure kinetics In the environment, chemical reactions to determining chemical kinetic rate constants and reaction mechanisms, both of which are required to fully understand environmental chemical processes. Kinetic measurements with traditional techniques, such as batch

Sparks, Donald L.

330

Three-dimensional simulations of anomalous absorption of laser radiation by plasma with supercritical density  

Science Conference Proceedings (OSTI)

A three-dimensional (3D) model of the interaction of laser radiation with plasma in the framework of Maxwell-Vlasov equations has been used to calculate the anomalous optical absorption in plasma of supercritical density. The results of calculations confirmed the development of anomalous absorption that was previously revealed by 2D models, which were insufficient for comparison to the experiment. Calculations were performed for a system containing about 10{sup 6} macroparticles that allowed the absorption coefficient and other characteristics of anomalous absorption in plasma with an inhomogeneous surface to be determined as functions of various parameters of the incident radiation and plasma target. Results are analyzed and estimations are obtained for the contributions of ionization processes and pair collisions of electrons, which show that these factors were quite reasonably ignored in the model. All quantitative results are obtained for the third harmonic of neodymium laser ({lambda} = 0.351 {mu}m) at a tenfold excess of the substance density over a critical value for this radiation.

Ginzburg, S. L.; Dyachenko, V. F. [Russian Academy of Sciences, Keldysh Institute for Applied Mathematics (Russian Federation); Imshennik, V. S. [Alikhanov Institute for Theoretical and Experimental Physics (Russian Federation); Paleychik, V. V.

2012-02-15T23:59:59.000Z

331

The Correlation of Coupled Heat and Mass Transfer Experimental Data for Vertical Falling Film Absorption  

Science Conference Proceedings (OSTI)

Absorption chillers are gaining global acceptance as quality comfort cooling systems. These machines are the central chilling plants and the supply for cotnfort cooling for many large commercial buildings. Virtually all absorption chillers use lithium bromide (LiBr) and water as the absorption fluids. Water is the refrigerant. Research has shown LiBr to he one of the best absorption working fluids because it has a high affinity for water, releases water vapor at relatively low temperatures, and has a boiling point much higher than that of water. The heart of the chiller is the absorber, where a process of simultaneous heat and mass transfer occurs as the refrigerant water vapor is absorbed into a falling film of aqueous LiBr. The more water vapor absorbed into the falling film, the larger the chiller?s capacity for supporting comfort cooling. Improving the performance of the absorber leads directly to efficiency gains for the chiller. The design of an absorber is very empirical and requires experimental data. Yet design data and correlations are sparse in the open literature. The experimental data available to date have been derived at LiBr concentrations ranging from 0.30 to 0.60 mass fraction. No literature data are readily available for the design operating conditions of 0.62 and 0.64 mass fraction of LiBr and absorber pressures of 0.7 and 1.0 kPa.

Keyhani, M.; Miller, W.A.

1999-11-14T23:59:59.000Z

332

The absorbent's solution flow process, non-parametric identification into an absorption chiller for air conditioning  

Science Conference Proceedings (OSTI)

The lithium bromide chillers supplied from solar collectors are used to provide proper environmental conditions into industrial and civil buildings. To maintain the appropriate values for the temperature into the chiller's boiler, a control unit is introduced ... Keywords: absorption chiller, flow process, system identification

Adrian Danila

2011-04-01T23:59:59.000Z

333

Analysis and comparison of active solar desiccant and absorption cooling systems. Part 1; Model description  

DOE Green Energy (OSTI)

A comparative analysis has been performed to compare the cooling and dehumidification performance of future ventilation-mode desiccant systems, proposed advanced absorption systems, and conventional vapor compression systems. A common framework has been developed for direct comparison of these different cooling technologies; this method is described in this paper.

Warren, M.L. (ASI Controls, San Ramon, CA (US)); Wahlig, M. (Lawrence Berkeley Lab., CA (USA). Applied Science Div.)

1991-02-01T23:59:59.000Z

334

Near-field scattering from red pigment particles: Absorption and spectral dependence  

E-Print Network (OSTI)

cornea,5 the effi- ciency of phosphors,6 and the appearance of reflective dis- play materials,7 paint,8Near-field scattering from red pigment particles: Absorption and spectral dependence L. E. Mc of pigment particles embedded in a transparent resin, the optical characteristics of the resulting film

French, Roger H.

335

An Efficient Method for Computing the Absorption of Solar Radiation by Water Vapor  

Science Conference Proceedings (OSTI)

An efficient method has been developed to compute the absorption of solar radiation by water vapor. The method is based on the molecular line parameters compiled by McClatchey et al. (1973) and makes use of the far-wing scaling approximation and ...

Ming-Dah Chou; Albert Arking

1981-04-01T23:59:59.000Z

336

Acid effects on the measurement of mercury by cold vapor atomic absorption spectrometry  

Science Conference Proceedings (OSTI)

The influence of nitric, hydrochloric and sulfuric acids on the measurement of mercury by cold vapor atomic absorption spectrometry has been investigated. Small pre-reduction peaks associated with the instability of mercury were observed in solutions containing less than or equal to 12.5, tuna using both of these approaches to overcome the interference problem proved to be successful.

Adeloju, S.B.; Mann, T.F.

1987-07-01T23:59:59.000Z

337

Forecasting of Chaotic Cloud Absorption Time Series for Meteorological and Plume Dispersion Modeling  

Science Conference Proceedings (OSTI)

A nonlinear forecasting method based on the reconstruction of a chaotic strange attractor from about 1.5 years of cloud absorption data obtained from half-hourly Meteosat infrared images was used to predict the behavior of the time series 24 h in ...

V. Prez-Muuzuri

1998-11-01T23:59:59.000Z

338

Absorptivity of semiconductors used in the production of solar cell panels  

SciTech Connect

The dependence of the absorptivity of semiconductors on the thickness of the absorbing layer is studied for crystalline silicon (c-Si), amorphous silicon (a-Si), cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS), and copper gallium diselenide (CuGaSe{sub 2}, CGS). The calculations are performed with consideration for the spectral distribution of AM1.5 standard solar radiation and the absorption coefficients of the materials. It is shown that, in the region of wavelengths {lambda} = {lambda}{sub g} = hc/E{sub g}, almost total absorption of the photons in AM1.5 solar radiation is attained in c-Si at the thickness d = 7-8 mm, in a-Si at d = 30-60 {mu}m, in CdTe at d = 20-30 {mu}m, and in CIS and CGS at d = 3-4 {mu}m. The results differ from previously reported data for these materials (especially for c-Si). In previous publications, the thickness needed for the semiconductor to absorb solar radiation completely was identified with the effective light penetration depth at a certain wavelength in the region of fundamental absorption for the semiconductor.

Kosyachenko, L. A., E-mail: lakos@chv.ukrpack.net; Grushko, E. V.; Mikityuk, T. I. [Chernivtsy National University (Ukraine)

2012-04-15T23:59:59.000Z

339

Solar Energy to Drive Absorption Cooling Systems Suitable for Small Building Applications  

E-Print Network (OSTI)

Air conditioning systems have a major impact on energy demand. With fossil fuels fast depleting, it is imperative to look for cooling systems that require less high-grade energy for their operation. In this context, absorption cooling systems have become increasingly popular in recent years from the viewpoints of energy and environment. Two types of the absorption chillers, the single effect and the half-effect systems, can operate using low temperature hot water. This paper presents the simulation results and an overview of the performance of low capacity single stage and half-effect absorption cooling systems, suitable for residential and small building applications. The primary heat source is solar energy supplied from flat plate collectors. The complete systems (solar collectors and absorption cooling system) were simulated using a developed software program. The energy and exergy analysis is carried out for each component of the two systems. When evaporator temperature is maintained constant at 5 C and the condenser temperature is fixed at 28 C, 32 C and 36 C respectively the percentage of the used energy covered by solar collectors and the percentage of auxiliary heating load were calculated versus time of day.

Gomri, R.

2010-01-01T23:59:59.000Z

340

Tailoring the absorption in a photonic crystal membrane: A modal Romain Peretti*a  

E-Print Network (OSTI)

crystal, absorption enhancement, photovoltaic solar cell, indoor solar cell, sensor 1. INTRODUCTION is of prime importance for solar [1] and indoor [2] photovoltaic cells or for sensors [3]. Parallel to this photovoltaic devices and sensors, we propose to implement photonic crystals on thin absorbing layers

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

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

E-Print Network (OSTI)

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

Grandidier, Jonathan

342

Sources of hot electrons in laser-plasma interaction with emphasis on Raman and turbulence absorption  

SciTech Connect

Heating targets with high power lasers results in a sizable fraction of the absorbed energy going into electrons of temperature much greater than thermal which can pre-heat the pellet core and accelerate fast ion blowoff which results in poor momentum transfer and hence poor compression efficiency. The present emphasis is to build lasers of higher frequency, ..omega../sub 0/, which at the same W/cm/sup 2/ results in more absorption into cooler electrons. Two physical reasons are that the laser can propagate to a higher electron density, n, infinity..omega../sub 0//sup 2/ resulting in more collisional inverse bremsstrahlung absorption proportional to n, and because the hot temperatures from some plasma absorption processes increase as the oscillatory velocity of an electron in the laser electric field v/sub 0//c = eE/(m/sub e/..omega../sub 0/). The heated electron temperatures from other plasma processes (Raman for example approx.(m/sub e//2)v/sup 2//sub phase/ and the higher laser frequency helps by increasing the competing collisional absorption and decreasing the Raman gain.

Estabrook, K.; Kruer, W.L.; Phillion, D.W.; Turner, R.E.; Campbell, E.M.

1982-04-06T23:59:59.000Z

343

The Effects of Very Large Drops on Cloud Absorption. Part I: Parcel Models  

Science Conference Proceedings (OSTI)

In an effort to bring more realism cloud-radiation calculations, arising-parcel model of cloud microphysics and a 191 waveband model of atmospheric radiation (ATRAD) have been brought to bear on the problem of cloud absorption of solar radiation, ...

W. J. Wiscombe; R. M. Welch; W. D. Hall

1984-04-01T23:59:59.000Z

344

An energy dispersive x-ray absorption spectroscopy beamline, X6A, at NSLS  

Science Conference Proceedings (OSTI)

An energy dispersive x-ray absorption spectroscopy instrument has been built at the X6A beam port of the x-ray ring at the National Synchrotron Light Source (NSLS). This instrument allows the collection of extended x-ray-absorption fine structure and/or x-ray absorption near-edge structure spectra for many elements on the millisecond time scale. The beamline employs a four-point crystal bender and a rectangular Si 220 crystal to access incident energies between 6.5 and 21 keV. Because the polychromator focuses the synchrotron beam to a narrow 100-[mu]m line, this experimental apparatus is ideal for x-ray absorption spectroscopy experiments in special environments such as at high pressures, for [ital in] [ital situ] experiments, and/or for very small samples. In this manuscript we will describe the instrument design and present data with which to evaluate the instrument. This beamline is available through the NSLS user proposal system.

Lee, P.L.; Beno, M.A.; Jennings, G.; Ramanathan, M.; Knapp, G.S.; Huang, K. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)); Bai, J. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) Department of Physics, Brooklyn College of CUNY, Brooklyn, New York 11210 (United States)); Montano, P.A. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) Department of Physics, University of Illinois, Chicago, Chicago, Illinois 60680 (United States))

1994-01-01T23:59:59.000Z

345

Ionization and absorption effects in high-order harmonic generation in gas-filled hollow fibers  

E-Print Network (OSTI)

, and dkq n ~u! qdKn ~u! being the phase-mismatch compo- nents due to the dispersion of the gas, waveguide! involved in Eq. ~10! depends not only on gas dispersion, but also on the dispersion of waveguide modes by the dispersion and absorption of a gas medium rather than by the parameters of the fiber itself. In other words

von der Linde, D.

346

Diffusion-absorption heat pump. Final report, November 1990-December 1994  

SciTech Connect

The gas-fired domestic refrigerator is a successful gas-fired appliance which fills a market niche where either low noise or independence from electric power is important. Such applications include hotel room refrigerators, recreational vehicles and remote area refrigeration. Current diffusion-absorption machines have poor performance. The current work is expected to demonstrate significant performance improvements over current technology.

Herold, K.E.

1996-06-01T23:59:59.000Z

347

Experiments on solar absorption using a greenhouse-effect gas in a thermal solar collector  

Science Conference Proceedings (OSTI)

This paper investigates an augmentation to the thermal solar absorption of solar collectors by introducing a greenhouse gas between the glazing and the absorber part of the solar collector. Experiments are designed and conducted to compare the effect of adding the gas on the efficiency of the collector without that addition. The maximum temperature rise of the absorber

Abdul Hai M. B. Alami

2010-01-01T23:59:59.000Z

348

Statistical Analysis of the Whole Body Absorption Depending on Anatomical Human Characteristics at the  

E-Print Network (OSTI)

overexposure, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Institute Absorption Rate (WBSAR). The study is conducted for the case of an exposure to a front plane wave at the 2100 the importance of the internal morphological factors such as muscle and fat proportions in the characterization

Paris-Sud XI, Université de

349

The Strengths of Near-Infrared Absorption Features Relevant to Interstellar and Planetary Ices  

E-Print Network (OSTI)

The abundances of ices in planetary environments have historically been obtained through measurements of near-infrared absorption features (lambda = 1.0-2.5 microns), and near-IR transmission measurements of materials present in the interstellar medium are becoming more common. For transmission measurements, the band strength (or absorption intensity) of an absorption feature must be known in order to determine the column density of an ice component. In the experiments presented here, we have measured the band strengths of the near-IR absorption features for several molecules relevant to the study of interstellar icy grain mantles and icy planetary bodies: CO (carbon monoxide), CO2 (carbon dioxide), C3O2 (carbon suboxide), CH4 (methane), H2O (water), CH3OH (methanol), and NH3 (ammonia). During a vacuum deposition, the sizes of the near-IR features were correlated with that of a studied mid-IR feature whose strength is well known from previous ice studies. These data may be used to determine ice abundances fro...

Gerakines, P A; Davis, A; Richey, C R

2005-01-01T23:59:59.000Z

350

Simulation and analysis of high efficiency absorption systems for solar cooling  

DOE Green Energy (OSTI)

A flexible modular computer code was developed for simulation of absorption systems. The code is capable to investigate, on a comparable basis, various cycles configurations with a variety of working fluids. In Phase 1 of the program, two open cycle absorption systems for solar energy were successfully simulated. Modifications which were applied to the code in Phase 2, allowed the analysis of systems with volatile absorbents, as used in advanced, high COP, absorption systems such as the GAX cycle. Ammonia-water database was developed into equation form and introduced to the code. That eliminated discontinuities in evaluating differentials used in the solver. Properties calculated with these equations fit well the tabulated data. This and other modifications allowed to model absorption cycles using ammonia-water. Single effect cycles converged in most ranges. Direct analysis of the code to advanced cycles, such as GAX, still encountered some convergence problems. It was, however, possible to analyze the GAX cycle in groups. The results show that high COP's are obtainable and are compatible with those reached by LBL. The properties of two additional pairs, that were developed in BG Univ., are reported. 27 refs., 13 figs., 13 tabs.

Shavit, A.; Haim, I. (Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering); Borde, I.; Jelinek, M. (Ben-Gurion Univ. of the Negev, Beersheba (Israel). Applied Research Inst.)

1989-05-31T23:59:59.000Z

351

Diacylglycerol Oil, 2nd EditionChapter 3 Digestion and Absorption of Diacylglycerol  

Science Conference Proceedings (OSTI)

Diacylglycerol Oil, 2nd Edition Chapter 3 Digestion and Absorption of Diacylglycerol Food Science Health Nutrition Biochemistry eChapters Food Science & Technology Health - Nutrition - Biochemistry D1F83BF1E780DD52F8F757EB9E0989F4

352

X-ray Absorption Due to Cold Gas in Cluster Cooling Cores  

E-Print Network (OSTI)

We have calculated the emergent X-ray properties for models of cluster cooling flows including the effects of accumulated cooled material. The opacity of this cooled gas can reduce the overall X-ray luminosity of the cooling flow, and values of Mdot based on these luminosities can underestimate the true value by factors of ~2. We find that accumulated cooled material can produce emergent surface brightness profiles much like those observed even for nearly homogeneous gas distributions. Consequently, much more of the gas may be cooling below X-ray emitting temperatures in the central regions of cooling flows (r cooling flows may have been underestimated. We show that distributed absorption in cooling flows produces a number of observable effects in the spectrum which may allow it to be differentiated from absorption due to gas in our Galaxy. These include a characteristic suppression of the continuum below ~2 keV, absorption features such as a redshifted O K-edge, and diminished intensity of resonance emission lines. Spectra including the effects of intrinsic absorption are not well fit by foreground absorbing models. Attempting to fit such models to the spatially resolved spectra can lead to underestimates of the true absorbing column by factors of 3-20. Fits to integrated spectra of the entire cooling flow region can either underestimate or overestimate the mass of the absorbing gas depending on the specifics of the model. We discuss the potential detection of these effects with AXAF, XMM, and Astro-E.

Michael W. Wise; Craig L. Sarazin

1999-03-09T23:59:59.000Z

353

The puzzle of the soft X-ray excess in AGN: absorption or reflection?  

E-Print Network (OSTI)

The 2-10 keV continuum of AGN is generally well represented by a single power law. However, at smaller energies the continuum displays an excess with respect to the extrapolation of this power law, called the ''soft X-ray excess''. Until now this soft X-ray excess was attributed, either to reflection of the hard X-ray source by the accretion disk, or to the presence of an additional comptonizing medium, giving a steep spectrum. An alternative solution proposed by Gierlinski and Done (2004) is that a single power law well represents both the soft and the hard X-ray emission and the impression of the soft X-ray excess is due to absorption of a primary power law by a relativistic wind. We examine the advantages and drawbacks of reflection versus absorption models, and we conclude that the observed spectra can be well modeled, either by absorption (for a strong excess), or by reflection (for a weak excess). However the physical conditions required by the absorption models do not seem very realistic: we would prefer an ''hybrid model''.

L. Chevallier; S. Collin; A. -M. Dumont; B. Czerny; M. Mouchet; A. C. Goncalves; R. W. Goosmann

2006-01-19T23:59:59.000Z

354

Absorption of zinc and iron by rats fed meals containing sorghum food products  

Science Conference Proceedings (OSTI)

Zinc and iron absorption from freeze-dried traditionally-prepared sorghum food products was studied in rats. After a period of marginal zinc or iron depletion, rats were fed test meals containing 1 of 4 sorghum foods cooked maize gruel or an inorganic mineral each of which was extrinsically labeled with either /sup 65/Zn or /sup 59/Fe before being added to the diets. Absorption was determined by whole body percent retention of the initial radioisotope dose over a period of 19 days. Iron was highly available from all products tested (75-83%) with no significant differences in absorption among groups (p>0.05). Zinc from fermented Aceta (97%) was more available than that from the other sorghum products (69-78%) or maize gruel (76%). Zinc from acid To (78%) and Aceta (97%) was as available as that from zinc oxide in the control diet (93%) (p>0.05). There were no significant differences in zinc absorption among groups fed Acid To (78%), neutral To (76), alkali To (69%) or maize gruel (76%) (psorghum foods. Iron and zinc were highly available from all sorghum foods. Reduction phytate by fermentation increased Zn availability.

Stuart, S.M.A.; Johnson, P.E.; Hamaker, B.; Kirleis, A.

1986-03-05T23:59:59.000Z

355

The Statistics of the Number of Neutron Collisions Prior to Absorption  

E-Print Network (OSTI)

The Statistics of the Number of Neutron Collisions Prior to Absorption Sara A. Pozzi* Oak Ridge University of Technology, Department of Reactor Physics, SE - 41296 Göteborg, Sweden Received May 19, 2005 of the number of collisions undergone by fast neutrons during slowing down until they are absorbed. We assume

Pázsit, Imre

356

Aspects of Graviton Detection: Graviton Emission and Absorption by Atomic Hydrogen  

E-Print Network (OSTI)

Graviton absorption cross sections and emission rates for hydrogen are calculated by both semi-classical and field theoretic methods. We point out several mistakes in the literature concerning spontaneous emission of gravitons and related phenomena, some of which are due to a subtle issue concerning gauge invariance of the linearized interaction Hamiltonian.

Stephen Boughn; Tony Rothman

2006-05-09T23:59:59.000Z

357

Monte Carlo Study of the Scattering Error of a Quartz Reflective Absorption Tube  

Science Conference Proceedings (OSTI)

A Monte Carlo model was used to study the scattering error of an absorption meter with a divergent light beam and a limited acceptance angle of the receiver. Reflections at both ends of the tube were taken into account. Calculations of the effect ...

Jacek Piskozub; Piotr J. Flatau; J. V. Ronald Zaneveld

2001-03-01T23:59:59.000Z

358

Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation  

SciTech Connect

This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose of this work was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. PNL researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH{sub 4}{sup +}). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

Anheier, N.C. Jr.; McDonald, C.E.; Cuta, J.M.; Cuta, F.M.; Olsen, K.B.

1995-05-01T23:59:59.000Z

359

Oxygen K-edge absorption spectra of small molecules in the gas phase  

SciTech Connect

The absorption spectra of O/sub 2/, CO, CO/sub 2/ and OCS have been recorded in a transmission mode in the energy region from 500 to 950 eV. Recent observation of EXAFS in these molecules is confirmed in this study. 7 refs., 3 figs.

Yang, B.X.; Kirz, J.; Sham, T.K.

1986-01-01T23:59:59.000Z

360

Atomic-absorption analysis in a graphite furnace fitted with a metal ballast collector  

SciTech Connect

One reason for the deterioration in sensitivity in the electrothermal atomic absorption spectroscopy of petroleum products is the uncontrolled spread and diffusion of the liquid throughout the furnace. This paper describes a metal ballast collector whose wettability and sorptive properties contain the sample and allow for its uniform and controlled evaporation and atomization.

Katskov, D.A.; Vasil' eva, L.A.; Grinshtein, I.L.; Savel' eva, G.O.

1987-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

Performance and Technique of Coherent 2-?m Differential Absorption and Wind Lidar for Wind Measurement  

Science Conference Proceedings (OSTI)

A coherent 2-?m differential absorption and wind lidar (Co2DiaWiL) has been built with a high-power Q-switched Tm,Hm:YLF laser to measure CO2 concentration and radial wind speed. The performance of the Co2DiaWiL is described and analyzed, with a ...

Hironori Iwai; Shoken Ishii; Ryoko Oda; Kohei Mizutani; Shinya Sekizawa; Yasuhiro Murayama

2013-03-01T23:59:59.000Z

362

ROSAT Evidence for Intrinsic Oxygen Absorption in Cooling Flow Galaxies and Groups  

E-Print Network (OSTI)

Using spatially resolved, deprojected ROSAT PSPC spectra of 10 of the brightest cooling flow galaxies and groups with low Galactic column densities we have detected intrinsic absorption over energies ~0.4-0.8 keV in half of the sample. Since no intrinsic absorption is indicated for energies below ~0.4 keV, the most reasonable model for the absorber is collisionally ionized gas at temperatures T=10^{5-6} K with most of the absorption arising from ionized states of oxygen but with a significant contribution from carbon and nitrogen. The soft X-ray emission of this warm gas can explain the sub-Galactic column densities of cold gas inferred within the central regions of most of the systems. Attributing the absorption to ionized gas reconciles the large columns of cold H and He inferred from EINSTEIN and ASCA with the lack of such columns inferred from ROSAT. Within the central ~10-20 kpc, where the constraints are most secure, the estimated mass of the ionized absorber is consistent with most (perhaps all) of the matter deposited by a cooling flow over the lifetime of the flow. Since the warm absorber produces no significant H or He absorption the large absorber masses are consistent with the negligible atomic and molecular H inferred from HI and CO observations of cooling flows. It is also found that if T > ~2x10^5 K then the optical and UV emission implied by the warm gas does not violate published constraints. Finally, we discuss how the prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified with new CHANDRA and XMM observations. (Abridged)

David A. Buote

2000-01-19T23:59:59.000Z

363

Effect of bile diversion on satiety and fat absorption from liquid and solid dietary sources  

Science Conference Proceedings (OSTI)

In previous studies, liquid fat has been used to determine the effect of bile diversion on fat absorption. Since protein digests, in addition to bile salts, are capable of solubilizing lipids, we hypothesized that fat incorporated in the protein-rich matrix of solid food would be less sensitive to bile diversion than fat ingested as an oil or liquid. Using (3H)glycerol triether as a nonabsorbable fat recovery marker, we determined how much (14C)triolein was absorbed from solid (chicken liver) and liquid (margarine) dietary sources. After a standard liquid/solid meal with either the chicken liver or margarine labeled, midintestinal chyme was collected for 6 hr, extracted, and counted for 14C and 3H activity. Zero, eighty, or one hundred percent of endogenous bile was diverted. Fat absorption from both chicken liver and margarine was nearly complete by midintestine with 0% diversion and was little affected by diversion of 80% of bile. Complete biliary diversion significantly decreased fat absorption from margarine (87.9 +/- 4.4 to 37.2 +/- 9.2%, P less than 0.05) but reduced (14C)triolein absorption from chicken liver less consistently and insignificantly (78.8 +/- 6.9 to 43.9 +/- 10.6%). These data indicate that fat absorption is not solely dependent on bile and support the hypothesis that fat ingested in a cellular matrix is less dependent on bile than liquid fat. Using these same animals but with the midintestinal cannulas plugged to expose the distal intestine to unabsorbed luminal nutrients, we also demonstrated that bile diversion of an initial meal reduced food consumption at a meal offered 3 hr later.

Doty, J.E.; Gu, Y.G.; Meyer, J.H.

1988-12-01T23:59:59.000Z

364

Parameterizations for the Absorption of Solar Radiation by O2 and CO2 with Application to Climate Studies  

Science Conference Proceedings (OSTI)

Simple and accurate parameterizations have been developed for computing the absorption of solar radiation due to O2 and CO2. The parameterizations are based on the findings that temperature has a minimal effect on the absorption and that the one-...

Ming-Dah Chou

1990-02-01T23:59:59.000Z

365

Synchrotron radiation x-ray absorption fine-structure and Raman studies on CdZnTe ternary alloys  

E-Print Network (OSTI)

The synchrotron radiation (SR) X-ray absorption fine-structure spectroscopy (XAFS) technology has been employed to obtained Zn K-edge absorption spectra for Cd1[subscript 1-x]Zn[subscript x]Te alloy with x = 0.03, 0.10, ...

Becla, Piotr

366

Investigations of Heme Protein Absorption Line Shapes, Vibrational Relaxation, and Resonance Raman Scattering on Ultrafast Time Scales  

E-Print Network (OSTI)

Investigations of Heme Protein Absorption Line Shapes, Vibrational Relaxation, and Resonance Raman of the deoxy photoproduct involves an initially broadened and red-shifted absorption band, which is observed the heme and the protein/solvent matrix in cooling the locally hot heme. Finally, we discuss the effects

Kumar, Anand T.N.

367

Isotope Enrichment Detection by Laser Ablation - Laser Absorption Spectrometry: Automated Environmental Sampling and Laser-Based Analysis for HEU Detection  

SciTech Connect

The global expansion of nuclear power, and consequently the uranium enrichment industry, requires the development of new safeguards technology to mitigate proliferation risks. Current enrichment monitoring instruments exist that provide only yes/no detection of highly enriched uranium (HEU) production. More accurate accountancy measurements are typically restricted to gamma-ray and weight measurements taken in cylinder storage yards. Analysis of environmental and cylinder content samples have much higher effectiveness, but this approach requires onsite sampling, shipping, and time-consuming laboratory analysis and reporting. Given that large modern gaseous centrifuge enrichment plants (GCEPs) can quickly produce a significant quantity (SQ ) of HEU, these limitations in verification suggest the need for more timely detection of potential facility misuse. The Pacific Northwest National Laboratory (PNNL) is developing an unattended safeguards instrument concept, combining continuous aerosol particulate collection with uranium isotope assay, to provide timely analysis of enrichment levels within low enriched uranium facilities. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy to characterize the uranium isotopic ratio through subtle differences in atomic absorption wavelengths. Environmental sampling (ES) media from an integrated aerosol collector is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes material from a 10 to 20-m diameter spot of the surface of the sampling media. The plume of ejected material begins as high-temperature plasma that yields ions and atoms, as well as molecules and molecular ions. We concentrate on the plume of atomic vapor that remains after the plasma has expanded and then cooled by the surrounding cover gas. Tunable diode lasers are directed through this plume and each isotope is detected by monitoring absorbance signals on a shot-to-shot basis. The media is translated by a micron resolution scanning system, allowing the isotope analysis to cover the entire sample surface. We also report, to the best of our knowledge, the first demonstration of laser-based isotopic measurements on individual micron-sized particles that are minor target components in a much larger heterogeneous mix of background particles. This composition is consistent with swipe and environmental aerosol samples typically collected for safeguards ES purposes. Single-shot detection sensitivity approaching the femtogram range and relative isotope abundance uncertainty better than 10% has been demonstrated using gadolinium isotopes as surrogate materials.

Anheier, Norman C.; Bushaw, Bruce A.

2010-01-01T23:59:59.000Z

368

X-RAY ABSORPTION SPECTROSCOPY OF TRANSITION METAL-MAGNESIUM HYDRIDE FILMS  

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

Spectroscopy of Transition Metal-Magnesium Spectroscopy of Transition Metal-Magnesium Hydride Thin Films T. J. Richardson a, *, B. Farangis a , J. L. Slack a , P. Nachimuthu b , R. Pereira b , N. Tamura b , and M. Rubin a a Environmental Energy Technologies Division, b Advanced Light Source, Ernest Orlando Lawrence Berkeley National Laboratory Berkeley, California 94720, USA *Corresponding author, E-mail address: tjrichardson@lbl.gov Abstract Mixed metal thin films containing magnesium and a first-row transition element exhibit very large changes in both reflectance and transmittance on exposure to hydrogen gas. Changes in electronic structure and coordination of the magnesium and transition metal atoms during hydrogen absorption were studied using dynamic in situ transmission mode X-ray absorption

369

Temperature controlled multiple pass absorption cell for gas phase chemical kinetics studies  

Science Conference Proceedings (OSTI)

The application of a Herriott-type optical multiple pass cell for absorption detection of transient species in temperature controlled laser pump-probe kinetics experiments is described. Using reaction initiation by laser photolysis in combination with reaction monitoring by absorption of a multiple pass laser allows confinement of the probed reaction volume to the temperature controlled region of a slow flow reactor. For transient measurements, this apparatus provides enhanced sensitivity from increased path length and accurate temperature control by limiting the pump-probe interaction volume. In addition, for a polarized probe laser, a simple arrangement using a polarizing beam splitter and a {lambda}/4 plate allows doubling of the path length. {copyright} {ital 1997 American Institute of Physics.}

Pilgrim, J.S.; Jennings, R.T.; Taatjes, C.A. [Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551-0969 (United States)

1997-04-01T23:59:59.000Z

370

Analysis of advanced conceptual designs for single-family-sized absorption chillers. Annual report  

DOE Green Energy (OSTI)

The objectives of the research reported is to develop and analyze new concepts for absorption cycles to improve the performance or reduce the cost of a 3-ton absorption chiller that can be used with solar collected heat. New refrigerant-absorbent pairs are investigated, as are additives to currently used refrigerant-absorbent pairs. Results are given of a literature search on those topics. An initial screening is reported to check the values of the heats of mixing of candidate refrigerants and adsorbents, and also to screen several candidate absorbents against water as a refrigerant. A modified apparatus and procedures for measurement of refrigerant-absorbent solubilities are described. Pressure-temperature-composition data for the R-22/E-181 pair were measured. Based on theory and the information found in the literature, a set of criteria and guidelines was developed that gives the desirable properties of the refrigerants, absorbents, and pairs. (LEW)

Not Available

1978-09-27T23:59:59.000Z

371

Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials  

SciTech Connect

Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.

Fischer, D.A. [National Institute of Standards and Technology, Gaithersburg, MD (United States); Mitchell, G.E.; Dekoven, B.M. [Dow Chemical Co., Midland, MI (United States); Yeh, A.T.; Gland, J.L. [Michigan Univ., Ann Arbor, MI (United States); Moodenbaugh, A.R. [Brookhaven National Lab., Upton, NY (United States)

1993-06-01T23:59:59.000Z

372

Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials  

SciTech Connect

Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.

Fischer, D.A. (National Institute of Standards and Technology, Gaithersburg, MD (United States)); Mitchell, G.E.; Dekoven, B.M. (Dow Chemical Co., Midland, MI (United States)); Yeh, A.T.; Gland, J.L. (Michigan Univ., Ann Arbor, MI (United States)); Moodenbaugh, A.R. (Brookhaven National Lab., Upton, NY (United States))

1993-01-01T23:59:59.000Z

373

New constraints in absorptive capacity and the optimum rate of petroleum output  

SciTech Connect

Economic policy in four oil-producing countries is analyzed within a framework that combines a qualitative assessment of the policy-making process with an empirical formulation based on historical and current trends in these countries. The concept of absorptive capacity is used to analyze the optimum rates of petroleum production in Iran, Iraq, Saudi Arabia, and Kuwait. A control solution with an econometric model is developed which is then modified for alternative development strategies based on analysis of factors influencing production decisions. The study shows the consistencies and inconsistencies between the goals of economic growth, oil production, and exports, and the constraints on economic development. Simulation experiments incorporated a number of the constraints on absorptive capacity. Impact of other constraints such as income distribution and political stability is considered qualitatively. (DLC)

El Mallakh, R

1980-01-01T23:59:59.000Z

374

Cascade Reverse Osmosis Air Conditioning System: Cascade Reverse Osmosis and the Absorption Osmosis Cycle  

SciTech Connect

BEETIT Project: Battelle is developing a new air conditioning system that uses a cascade reverse osmosis (RO)-based absorption cycle. Analyses show that this new cycle can be as much as 60% more efficient than vapor compression, which is used in 90% of air conditioners. Traditional vapor-compression systems use polluting liquids for a cooling effect. Absorption cycles use benign refrigerants such as water, which is absorbed in a salt solution and pumped as liquidreplacing compression of vapor. The refrigerant is subsequently separated from absorbing salt using heat for re-use in the cooling cycle. Battelle is replacing thermal separation of refrigerant with a more efficient reverse osmosis process. Research has shown that the cycle is possible, but further investment will be needed to reduce the number of cascade reverse osmosis stages and therefore cost.

None

2010-09-01T23:59:59.000Z

375

Cooling flows, central galaxy--cluster alignments, X-ray absorption and dust  

E-Print Network (OSTI)

We present the analysis of pointed ROSAT PSPC observations of five of the most luminous, intermediate redshift ($0.1 cooling flows. The alignment between CCGs and their host clusters has been investigated. For those clusters with cooling flows, the position angles of the X-ray emission from the clusters and the optical emission from the CCGs agrees within 5 degrees. For the one probable non-cooling flow cluster in the sample, Abell 2208, the alignment is significantly poorer. We examine the evidence for intrinsic X-ray absorption in the clusters. The X-ray spectra for Abell 1068 and Abell 1664 show that the cooling flows in these clusters are intrinsically absorbed by equivalent hydrogen column densities $\\geq 10^{21} atom cm$^{-2}$. The optical spectra of the CCGs in these clusters exhibit substantial intrinsic reddening, at levels consistent with the X-ray absorption results if standard dust to gas ratios are assumed.

S. W. Allen; A. C. Fabian; A. C. Edge; H. Bohringer; D. A. White

1995-03-28T23:59:59.000Z

376

X-ray Absorption Due to Cold Gas in Cluster Cooling Cores  

E-Print Network (OSTI)

We have calculated the emergent X-ray properties for models of cluster cooling flows including the effects of accumulated cooled material. The opacity of this cooled gas can reduce the overall X-ray luminosity of the cooling flow, and values of Mdot based on these luminosities can underestimate the true value by factors of ~2. We find that accumulated cooled material can produce emergent surface brightness profiles much like those observed even for nearly homogeneous gas distributions. Consequently, much more of the gas may be cooling below X-ray emitting temperatures in the central regions of cooling flows (r cooling flows may have been underestimated. We show that distributed absorption in cooling flows produces a number of observable effects in the spectrum which may allow it to be differentiated from absorption due to gas in our Galaxy. Th...

Wise, M W; Wise, Michael W.; Sarazin, Craig L.

1999-01-01T23:59:59.000Z

377

Absorption and emission line studies of gas in the Milky Way halo  

E-Print Network (OSTI)

We perform a systematic study of physical properties and distribution of neutral and ionised gas in the halo of the Milky Way (MW). Beside the large neutral intermediate- and high-velocity cloud (IVC, HVC) complexes there exists a population of partly ionised gaseous structures with low-column densities that have a substantial area filling factor. The origin and nature of these structures are still under debate. We analyse the physical parameters of the MW halo gas and the relation to quasar (QSO) metal-absorption line systems at low and high redshifts. For this purpose we combine new HI 21-cm data from the EBHIS and GASS surveys with optical quasar absorption line data to study the filling factor and distribution of these gaseous clouds in the halo at HI densities below 10^19 1/cm^2. This study is important to understand the evolution of the MW in particular and the gas accretion mechanisms of galaxies in general.

Bekhti, N Ben; Winkel, B; Kerp, J; Kalberla, P; Klein, U; Murphy, M T

2010-01-01T23:59:59.000Z

378

Regeneration of an aqueous solution from an acid gas absorption process by matrix stripping  

DOE Patents (OSTI)

Carbon dioxide and other acid gases are removed from gaseous streams using aqueous absorption and stripping processes. By replacing the conventional stripper used to regenerate the aqueous solvent and capture the acid gas with a matrix stripping configuration, less energy is consumed. The matrix stripping configuration uses two or more reboiled strippers at different pressures. The rich feed from the absorption equipment is split among the strippers, and partially regenerated solvent from the highest pressure stripper flows to the middle of sequentially lower pressure strippers in a "matrix" pattern. By selecting certain parameters of the matrix stripping configuration such that the total energy required by the strippers to achieve a desired percentage of acid gas removal from the gaseous stream is minimized, further energy savings can be realized.

Rochelle, Gary T. (Austin, TX); Oyenekan, Babatunde A. (Katy, TX)

2011-03-08T23:59:59.000Z

379

Analysis and comparison of active solar desiccant and absorption cooling systems. Part 2; Annual simulation results  

DOE Green Energy (OSTI)

A comparative analysis has been performed to compare the cooling and dehumidification performance of future ventilation mode desiccant systems, proposed advanced absorption systems, and conventional vapor compression systems. A common framework has been developed for direct comparison of these different cooling technologies; this method is described in a companion paper. This paper presents the application of this method to annual simulations of cooling system performance in five cities.

Warren, M.L. (ASI Controls, San Ramon, CA (US)); Wahlig, M. (Lawrence Berkeley Lab., CA (USA). Applied Science Div.)

1991-02-01T23:59:59.000Z

380

Electromagnetic Energy, Absorption, and Casimir Forces. I. Uniform Dielectric Media in Thermal Equilibrium  

E-Print Network (OSTI)

The derivation of Casimir forces between dielectrics can be simplified by ignoring absorption, calculating energy changes due to displacements of the dielectrics, and only then admitting absorption by allowing permittivities to be complex. As a first step towards a better understanding of this situation we consider in this paper the model of a dielectric as a collection of oscillators, each of which is coupled to a reservoir giving rise to damping and Langevin forces on the oscillators and a noise polarization acting as a source of a fluctuating electromagnetic (EM) field in the dielectric. The model leads naturally to expressions for the quantized EM fields that are consistent with those obtained by different approaches, and also results in a fluctuation-dissipation relation between the noise polarization and the imaginary part of the permittivity; comparison with the Rytov fluctuation-dissipation relation employed in the well-known Lifshitz theory for the van der Waals (or Casimir) force shows that the Lifshitz theory is actually a classical stochastic electrodynamical theory. The approximate classical expression for the energy density in a band of frequencies at which absorption in a dielectric is negligible is shown to be exact as a spectral thermal equilibrium expectation value in the quantum-electrodynamical theory. Our main result is the derivation of an expression for the QED energy density of a uniform dispersive, absorbing media in thermal equilibrium. The spectral density of the energy is found to have the same form with or without absorption. We also show how the fluctuation-dissipation theorem ensures a detailed balance of energy exchange between the (absorbing) medium, the reservoir and the EM field in thermal equilibrium.

F. S. S. Rosa; D. A. R. Dalvit; P. W. Milonni

2009-11-14T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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

ABSORPTION OF I$sup 131$ BY THYROID GLAND IN ATHLETES DURING PHYSICAL EXERTION  

SciTech Connect

Radioiodine absorption by the thyroid gland after prolonged physical exercise (3000 m race) was studied in 16 athletes, aged 20 to 24 years. Two hours after administration of the isotope the level of its accumulation in the gland was halved. In 24 and 72 hours the content of radioiodine in the gland was higher than in experimental conditions without physical exercise. The phenomenon described evidently reflects the normal reaction of the thyroid gland of athletes to habitual physical exercise. (auth)

Khorol, I.S.

1963-11-01T23:59:59.000Z

382

Energy Absorption and Storage in a Hamiltonian System in Partial Contact with a Heat Bath  

E-Print Network (OSTI)

To understand the mechanism allowing for long-term storage of excess energy in proteins, we study a Hamiltonian system consisting of several coupled pendula in partial contact with a heat bath. It is found that energy absorption and storage are possible when the motion of each pendulum switches between oscillatory (vibrational) and rotational modes. The relevance of our mechanism to protein motors is discussed.

Naoko Nakagawa; Kunihiko Kaneko

1999-03-02T23:59:59.000Z

383

Evaluation of the absorption capacity of various absorbers by reversed-phase chromatography  

Science Conference Proceedings (OSTI)

An investigation of the separation of alkanes, alkenes, and cycloalkanes from benzene in coke oven gas was presented. The absorption index was determined for benzene and n-octane as a function of temperature in methylnaphthalene, coal oil, solar oil, polyalkylbenzenes, tetraline, and 1,7-dimethylnaphthalene by gas chromatography. It was concluded that the best absorbers for the recovery of benzene were tetraline and coal oil. The most efficient absorber present in wash oil was methylnaphthalene. (JMT)

Mariich, L.I.; Ambrozevich, F.N.; Platonova, L.L.

1982-01-01T23:59:59.000Z

384

Program on Technology Innovation: Combustion Exhaust Gas Monitoring with Laser Absorption Sensors  

Science Conference Proceedings (OSTI)

In current plant practice, the operator of a coal-fired boiler must typically rely on a limited number of point measurements of exhaust-gas oxygen and nitric oxides (NOX) to support combustion and selective catalytic reduction (SCR) control efforts with the goal of meeting emissions reduction mandates. As a possible alternative, tunable diode laser technology offers the potential for enabling a much richer set of measurements to be obtained using in situ, species-specific laser absorption sensors. This t...

2012-07-11T23:59:59.000Z

385

Development and proof-testing of advanced absorption refrigeration cycle concepts  

SciTech Connect

The overall objectives of this project are to evaluate, develop, and proof-test advanced absorption refrigeration cycles that are applicable to residential and commercial heat pumps for space conditioning. The heat pump system is to be direct-fired with natural gas and is to use absorption working fluids whose properties are known. Target coefficients of performance (COPs) are 1.6 at 47{degrees}F and 1.2 at 17{degrees} in the heating mode, and 0.7 at 95{degree}F in the cooling mode, including the effect of flue losses. The project is divided into three phases. Phase I entailed the analytical evaluation of advanced cycles and included the selection of preferred concepts for further development. Phase II involves the development and testing of critical components and of a complete laboratory breadboard version of the selected system. Phase III calls for the development of a prototype unit and is contingent on the successful completion of Phase II. This report covers Phase I work on the project. In Phase 1, 24 advanced absorption cycle/fluid combinations were evaluated, and computer models were developed to predict system performance. COP, theoretical pump power, and internal heat exchange were calculated for each system, and these calculations were used as indicators of operating and installed costs in order to rank the relative promise of each system. The highest ranking systems involve the cycle concept of absorber/generator heat exchange, generator heat exchanger/absorber heat exchange, regeneration, and resorption/desorption, in combination with the NH{sub 3}/H{sub 2}O/LiBr ternary absorption fluid mixture or with the NH{sub 3}/H{sub 2}O binary solution. Based upon these conclusions, the recommendation was made to proceed to Phase II, the laboratory breadboard proof-of- concept.

Modahl, R.J.; Hayes, F.C. (Trane Co., La Crosse, WI (United States). Applied Unitary/Refrigeration Systems Div.)

1992-03-01T23:59:59.000Z

386

Performance of an air-cooled ammonia-water absorption air conditioner at low generator temperatures  

DOE Green Energy (OSTI)

An ammonia--water absorption air conditioning system has been tested to investigate the stability of operation near the cut-off conditions. Circulation ratios were from 8 to 30. Relations for the estimation of the coefficient of performance and for the prediction of operating temperatures were derived and verified experimentally. Possible operating conditions for an air-cooled ammonia--water air conditioning system were concluded.

Dao, K.; Simmons, M.; Wolgast, R.; Wahlig, M.

1976-08-01T23:59:59.000Z

387

Optimal absorption pressure for CO/sub 2/ recovery from flue gas calculated  

SciTech Connect

This paper calculates the cost of separating carbon dioxide from flue gas for enhanced oil recovery (EOR). It diagrams a carbon dioxide recovery plant and presents tables with costs of carbon dioxide recovery at various absorption pressures, and cost in various EOR project. It shows that the utility cost is a dominant factor and that a gas compressor does not reduce the equipment cost effectively at low pressure and concludes that 70 psig is the optimal operating pressure.

Fang, C.S.; Fan, S.K.

1982-11-22T23:59:59.000Z

388

Water vapor and greenhouse trapping: The role of far infrared absorption  

SciTech Connect

Few observations have been made of atmospheric absorption across the far infra-red. Yet water vapour absorption in this spectral region may significantly effect climate. The impact of far infra-red absorption is assessed by calculating the spectral variation of the total and water vapour greenhouse effects, for the sub-arctic winter (SAW) and tropical (TRP) standard atmospheres. Although the calculated efficiency of greenhouse trapping peaks outside of the far infra-red, the low strength there of the Planck function causes relatively small absolute forcings, except in the carbon dioxide and ozone bands. The sensitivity of the normalised greenhouse effect to water vapour concentration is largest in the far infra-red for the SAW atmosphere, and in the window region for the TRP. The sensitivity differs most between the two atmospheres in the far infra-red, over the middle/upper troposphere; in the SAw case the contribution from the water vapour continuum is virtually eliminated. Improved spectral observations and simulations at far infra-red wavelengths thus appear necessary to better understand the contemporary greenhouse effect, and to validate models of climate change. 16 refs., 3 figs., 1 tab.

Sinha, A.; Harries, J.E. [Imperial College of Science, Technology and Medicine, Prince Consort Road (United Kingdom)

1995-08-15T23:59:59.000Z

389

Optimization of a solar powered absorption cycle under Abu Dhabi's weather conditions  

SciTech Connect

In order for the solar absorption air conditioners to become a real alternative to the conventional vapour compression systems, their performance has to be improved and their total cost has to be reduced. A solar powered absorption cycle is modeled using the Transient System Simulation (TRNSYS) program and Typical Meteorological Year 2 data of Abu Dhabi. It uses evacuated tube collectors to drive a 10 kW ammonia-water absorption chiller. Firstly, the system performance and its total cost are optimized separately using single objective optimization algorithms. The design variables considered are: the collector slope, the collector mass flow rate, the collector area and the storage tank volume. The single objective optimization results show that MATLAB global optimization methods agree with the TRNSYS optimizer. Secondly, MATLAB is used to solve a multi-objective optimization problem to improve the system's performance and cost, simultaneously. The optimum designs are presented using Pareto curve and show the potential improvements of the baseline system. (author)

Al-Alili, A.; Hwang, Y.; Radermacher, R. [Department of Mechanical Engineering, University of Maryland, College Park, MD (United States); Kubo, I. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi (United Arab Emirates)

2010-12-15T23:59:59.000Z

390

Effects of angiotensin II and ionomycin on fluid and bicarbonate absorption in the rat proximal tubule  

SciTech Connect

Microperfusion of proximal convoluted tubule(PCT) and peritubular capillaries was performed to examine the effects of angiotensin II(Ang II) and ionomycin on fluid and bicarbonate absorption. Bicarbonate was determined by microcalorimetry and C-14 inulin was used as a volume marker. The rates of bicarbonate absorption (JHCO/sub 3/) was 143 peq/min x mm and fluid absorption(Jv) was 2.70 nl/min x mm, when PCT and capillary perfusate contained normal Ringer solution. Addition of Ang II (10/sup -6/M) to the capillary perfusate caused reductions of JHCO/sub 3/ and Jv by 35%. A similar effect was observed when ionomycin was added to the capillary perfusate. Ang II antagonist, (Sar/sup 1/, Ile/sup 8/)-Angiotensin II(10/sup -6/M), completely blocked the inhibitory effect of Ang II on Jv and JHCO/sub 3/. Removal of calcium from both luminal and capillary perfusate did not change the effect of Ang II on Jv and JHCO/sub 3/. Our results indicate that Ang II inhibits the sodium-hydrogen exchanger in the proximal tubule via interacting with angiotensin receptor. The mechanism of Ang II action may involve mobilization of intracellular calcium.

Chatsudthipong, V.; Chan, Y.L.

1986-03-01T23:59:59.000Z

391

Vertical-tube aqueous LiBr falling film absorption using advanced surfaces  

SciTech Connect

A heat and mass transfer test stand was fabricated and used to investigate nonisothermal falling film absorption of water vapor into a solution of aqueous lithium bromide. The absorber was made of borosilicate glass for visual inspection of the failing film. Experiments were conducted on internally cooled tubes of about 0.019 m outside diameter and of 1.53 m length. Testing evaluated a single absorber tube`s performance at varying operating conditions, namely different cooling-water flow rates, solution flow rates, pressures, temperatures, and concentrations. Advanced surfaces were identified that enhanced absorber load and the mass of absorbed vapor. A pin-fin tube with 6.4mm pitch absorbed about 225% more mass than did a smooth tube. A grooved tube was the d best performer with 175% enhancement over the smooth tube. Increasing the cooling water flow rate to 1.893 {times} 10{sup {minus}4} m{sup 3}/s caused about a 300% increase in the mass absorbed for the grooved tube compared with the smooth tube. Results showed that the pin-fin tube with 6.4-mm pitch and the grooved tubes may enhance absorption to levels comparable to chemical enhancement in horizontal smooth tube absorbers. Absorber load, the transport coefficients, and pertinent absorption data are presented as functions of dimensionless numbers. These experimental data will prove useful in formulating analytical tools to predict vertical-tube absorber performance.

Miller, W.A. [Oak Ridge National Lab., TN (United States); Perez-Blanco, H. [Pennsylvania State Univ., University Park, PA (United States)

1993-10-01T23:59:59.000Z

392

Method and apparatus for measuring butterfat and protein content using microwave absorption techniques  

SciTech Connect

A self calibrating method and apparatus for measuring butterfat and protein content based on measuring the microwave absorption of a sample of milk at several microwave frequencies. A microwave energy source injects microwave energy into the resonant cavity for absorption and reflection by the sample undergoing evaluation. A sample tube is centrally located in the resonant cavity passing therethrough and exposing the sample to the microwave energy. A portion of the energy is absorbed by the sample while another portion of the microwave energy is reflected back to an evaluation device such as a network analyzer. The frequency at which the reflected radiation is at a minimum within the cavity is combined with the scatter coefficient S.sub.11 as well as a phase change to calculate the butterfat content in the sample. The protein located within the sample may also be calculated in a likewise manner using the frequency, S.sub.11 and phase variables. A differential technique using a second resonant cavity containing a reference standard as a sample will normalize the measurements from the unknown sample and thus be self-calibrating. A shuttered mechanism will switch the microwave excitation between the unknown and the reference cavities. An integrated apparatus for measuring the butterfat content in milk using microwave absorption techniques is also presented.

Fryer, Michael O. (Roberts, ID); Hills, Andrea J. (Iowa City, IA); Morrison, John L. (Idaho Falls, ID)

2000-01-01T23:59:59.000Z

393

A laboratory-scale burner seeded with potassium for calibration of potassium emission/absorption instruments  

DOE Green Energy (OSTI)

In magnetohydrodynamic (MHD) power systems, potassium may be used to enhance the electrical conductivity of the high temperature products of combustion. In order to better evaluate the performance of MHD generators, it is desirable to be able to measure the distribution of the electrical conductivity of the gases throughout the channel through which the hot gases are passing. One such system is based on the emission/absorption spectra of potassium as a function of temperature. Diagnostic instruments, based on the emission/absorption characteristics of potassium in a flame or plasma require calibration in known temperature and potassium concentration conditions. A laboratory-scale hydrogen/oxygen burner which is seeded with gaseous potassium has been designed, fabricated, and operated for the purpose of providing a calibration facility for the potassium emission/absorption spectrographic (PE/AS) instrument. A nickel block was machined appropriately to provide separate flows of oxygen, hydrogen, and potassium vapor in a hot nitrogen stream mixed with hydrogen. A potassium evaporator was designed and fabricated to allow hot nitrogen gas to bubble through hot molten potassium to provide a known mass fraction of potassium to the resultant flame. The vapor pressure variation of the potassium with temperature was used to predict the amount of potassium carried to the flame by assuming that the hot nitrogen stream resulted in a saturated mixture as it bubbled through the heated molten potassium. Operational aspects as well as safety considerations in the operation of this burner are described. 10 refs., 1 fig.

Bouchillon, C.W.

1991-01-01T23:59:59.000Z

394

THE EFFECT OF 3HE ON LOW PRESSURE HYDRIDE ABSORPTION MEASUREMENTS WITH TRITIUM  

DOE Green Energy (OSTI)

Absorption isotherm data exists for a wide variety of hydrogen-metal systems. When working with high purity gases, appropriately sized equipment, and hydrides with equilibrium pressures above several hundred Pa, data collection is relatively straightforward. Special consideration must be given to experiments involving low equilibrium pressure hydrides, as even sub-ppm levels of gas impurities can generate partial pressures many times greater than the equilibrium pressures to be measured. Tritium absorption experiments are further complicated by the continuous generation of helium-3. The time required to transfer and absorb a known quantity of tritium onto a sample ultimately limits the minimum pressure range that can be studied using the standard technique. Equations are presented which show the pressure of helium-3 in a sample cell based on the amount of tritium to be absorbed, the sample cell volume and temperature, and the decay time of tritium. Sample calculations for zirconium show that at 300 C, the estimated helium-3 pressure in the cell will be equal to the hydrogen absorption pressure after only milliseconds of tritium decay. An alternate method is presented that permits the collection of equilibrium data at pressures orders of magnitude lower than possible using a direct approach.

Staack, G.; Klein, J.

2011-01-20T23:59:59.000Z

395

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

Science Conference Proceedings (OSTI)

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

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

2004-01-01T23:59:59.000Z

396

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

397

EvaporationCondensation Effects on Resonant Photoacoustics of Volatile Aerosols  

Science Conference Proceedings (OSTI)

In determining the optical properties of the atmosphere, the measurement of light absorption by aerosols is particularly challenging, and yet it is important because of the influence of strongly absorbing black carbon on climate and atmospheric ...

Richard Raspet; William V. Slaton; W. Patrick Arnott; Hans Moosmller

2003-05-01T23:59:59.000Z

398

COSMOLOGICAL EVOLUTION OF ATOMIC GAS AND IMPLICATIONS FOR 21 cm H I ABSORPTION  

SciTech Connect

Galaxy disks are shown to contain a significant population of atomic clouds of 100 pc linear size which are self-opaque in the 21 cm transition. These objects have H I column densities as high as 10{sup 23} cm{sup -2} and contribute to a global opacity correction factor of 1.34 {+-} 0.05 that applies to the integrated 21 cm emission to obtain a total H I mass estimate. High-resolution, opacity-corrected images of the nearest external galaxies have been used to form a robust redshift zero distribution function of H I, f(N{sub HI}, X, z = 0), the probability of encountering a specific H I column density along random lines of sight per unit comoving distance. This is contrasted with previously published determinations of f(N{sub HI}, X) at z = 1 and 3. A systematic decline of moderate column density (18 < log(N{sub H)} < 21) H I is observed with decreasing redshift that corresponds to a decline in surface area of such gas by a factor of five since z = 3. The number of equivalent Damped Lyman Alpha absorbers (log(N{sub HI})>20.3) has also declined systematically over this redshift interval by a similar amount, while the cosmological mass density in such systems has declined by only a factor of two to its current, opacity-corrected value of {Omega}{sup DLA}{sub HI}(z = 0) = 5.4 {+-} 0.9 Multiplication-Sign 10{sup -4}. We utilize the tight but strongly nonlinear dependence of 21 cm absorption opacity on column density at z = 0 to transform our high-resolution H I images into ones of 21 cm absorption opacity. These images are used to calculate distribution and pathlength functions of integrated 21 cm opacity. We suggest that that this z = 0 calibration may also apply at higher redshift. In this case, the incidence of deep 21 cm absorption systems is predicted to show very little evolution with redshift, while that of faint absorbers should decline by a factor of 5 between z = 3 and the present. We explicitly consider the effects of H I absorption against background sources that are extended relative to the 100 pc intervening absorber size scale. Extended background sources result in dramatically altered distribution and pathlength functions which are insensitive to the predicted redshift evolution. Future surveys of 21 cm absorption will require very high angular resolution, of about 15 mas, for their unambiguous interpretation.

Braun, Robert, E-mail: Robert.Braun@csiro.au [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia)

2012-04-10T23:59:59.000Z

399

Quantitative broadband absorption and scattering spectroscopy in turbid media by combined frequency-domain and steady state methodologies  

DOE Patents (OSTI)

A technique for measuring broadband near-infrared absorption spectra of turbid media that uses a combination of frequency-domain and steady-state reflectance methods. Most of the wavelength coverage is provided by a white-light steady-state measurement, whereas the frequency-domain data are acquired at a few selected wavelengths. Coefficients of absorption and reduced scattering derived from the frequency-domain data are used to calibrate the intensity of the steady-state measurements and to determine the reduced scattering coefficient at all wavelengths in the spectral window of interest. The absorption coefficient spectrum is determined by comparing the steady-state reflectance values with the predictions of diffusion theory, wavelength by wavelength. Absorption spectra of a turbid phantom and of human breast tissue in vivo, derived with the combined frequency-domain and steady-state technique, agree well with expected reference values.

Tromberg, Bruce J. (Irvine, CA); Berger, Andrew J. (Rochester, NY); Cerussi, Albert E. (Lake Forest, CA); Bevilacqua, Frederic (Costa Mesa, CA); Jakubowski, Dorota (Irvine, CA)

2008-09-23T23:59:59.000Z

400

Rate-Based Modeling of Reactive Absorption of CO2 and H2S into Aqueous Methyldiethanolamine  

E-Print Network (OSTI)

at Austin, Austin, Texas 78712 A general framework was developed to model the transport processes that take into the mass and energy balance at a given segment or tray of the column for the simulataneous absorption of CO

Rochelle, Gary T.

Note: This page contains sample records for the topic "aerosol absorption absorption" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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401

Influence of technological factors on statics of hydrogen sulfide absorption from coke-oven gas by the ammonia process  

SciTech Connect

The basic technological factors that determine the effectiveness of hydrogen sulfide absorption from coke-oven gas by the cyclic ammonia process are the initial H/sub 2/S content of the gas, the degree of purification, the absorption temperature and the NH/sub 3/ and CO/sub 2/ contents of the absorbent solution. The effects of these factors on the statics of hydrogen sulfide absorption are studied. The investigation is based on the phase-equilibrium distributions of components in the absorption-desorption gas-cleaning cycle. The mathematical model is presented which includes the solution of a system of chemical equilibrium equations for reactions in the solution, material balances, and electrical neutrality. 4 references, 5 figures, 1 table.

Nazarov, V.G.; Kamennykh, B.M.; Rus'yanov, N.D.

1983-01-01T23:59:59.000Z

402

Spectrally Consistent Scattering, Absorption, and Polarization Properties of Atmospheric Ice Crystals at Wavelengths from 0.2 to 100 ?m  

Science Conference Proceedings (OSTI)

A data library is developed containing the scattering, absorption, and polarization properties of ice particles in the spectral range from 0.2 to 100 ?m. The properties are computed based on a combination of the Amsterdam discrete dipole ...

Ping Yang; Lei Bi; Bryan A. Baum; Kuo-Nan Liou; George W. Kattawar; Michael I. Mishchenko; Benjamin Cole

2013-01-01T23:59:59.000Z

403

Measurement and modeling of infrared nonlinear absorption coefficients and laser-induced damage thresholds in Ge and GaSb  

SciTech Connect

Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, we measure two-photon and free-carrier absorption coefficients for Ge and GaSb at 2.05 and 2.5 {mu}m for the first time, to our knowledge. Results agreed well with published theory. Single-shot damage thresholds were also measured at 2.5 {mu}m and agreed well with modeled thresholds using experimentally determined parameters including nonlinear absorption coefficients and temperature dependent linear absorption. The damage threshold for a single-layer Al{sub 2}O{sub 3} anti-reflective coating on Ge was 55% or 35% lower than the uncoated threshold for picosecond or nanosecond pulses, respectively.

Wagner, T. J.; Bohn, M. J.; Coutu, R. A. Jr. [Air Force Institute of Technology, Wright Patterson Air Force Base, Ohio 45433 (United States); Gonzalez, L. P.; Murray, J. M.; Guha, S. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States); Schepler, K. L. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States)

2010-10-15T23:59:59.000Z

404

Depth profiling the optical absorption and thermal reflection coefficient via an analysis based on the method of images (abstract)  

Science Conference Proceedings (OSTI)

The problem of depth profiling optical absorption in a thermally depth variable solid is a problem of direct interest for the analysis of complex structured materials. In this work

J. F. Power

2003-01-01T23:59:59.000Z

405

A Refined Method of Parameterizing Absorption Coefficients among Multiple Gases Simultaneously from Line-by-Line Data  

Science Conference Proceedings (OSTI)

An extension of the correlated-k distribution method that uses spectral-mapping techniques was derived to parameterize line-by-line absorption coefficients for multiple gases simultaneously for use in three-dimensional atmospheric models. In a ...

Mark Z. Jacobson

2005-02-01T23:59:59.000Z

406

Eye-Safe Diode-Laser-Based Micropulse Differential Absorption Lidar (DIAL) for Water Vapor Profiling in the Lower Troposphere  

Science Conference Proceedings (OSTI)

A second-generation diode-laser-based master oscillator power amplifier (MOPA) configured micropulse differential absorption lidar (DIAL) instrument for profiling of lower-tropospheric water vapor is presented. The DIAL transmitter is based on a ...

Amin R. Nehrir; Kevin S. Repasky; John L. Carlsten

2011-02-01T23:59:59.000Z

407

Modeling of Solar-Powered Single-Effect Absorption Cooling System and Supermarket Refrigeration/HVAC System.  

E-Print Network (OSTI)

?? This thesis consists of two different research problems. In the first one, the aim is to model and simulate a solar-powered, single-effect, absorption refrigeration (more)

Bahman, Ammar Mohammad Khalil

2011-01-01T23:59:59.000Z

408

Modeling of Solar-Powered Single-Effect Absorption Cooling System and Supermarket Refrigeration/HVAC System.  

E-Print Network (OSTI)

??This thesis consists of two different research problems. In the first one, the aim is to model and simulate a solar-powered, single-effect, absorption refrigeration system (more)

Bahman, Ammar

2011-01-01T23:59:59.000Z

409

Effects of metallic absorption and the corrugated layer on the optical extraction efficiency of organic light-emitting diodes  

E-Print Network (OSTI)

The absorption of a metallic cathode in OLEDs is analyzed by using FDTD calculation. As the light propagates parallel to the layer, the intensity of Ez polarization decreases rapidly. The intensity at 2.0 um from the dipole is less than a quarter of that at 0.5 um. The strong absorption by a cathode can be a critical factor when considering the increase of optical extraction by means of bending the optical layers. The calculation indicates that the corrugation of layers helps the guided light escape the guiding layer, but also increases the absorption into a metallic cathode. The final optical output power of the corrugated OLED can be smaller than that of the flat OLED. On the contrary, the corrugated structure with a non-absorptive cathode increases the optical extraction by nearly two times.

Lee, Baek-Woon

2011-01-01T23:59:59.000Z

410

Influence of the cobalt particle size in the CO hydrogenation reaction studied by in situ X-ray absorption spectroscopy  

E-Print Network (OSTI)

Cobalt, nanoparticles, Fischer-Tropsch, X-ray absorption (oxides [5] and Fischer-Tropsch (FT) synthesis [6,7]. Itswhich is inactive for Fischer-Tropsch synthesis. This oxide

Herranz, Tirma

2010-01-01T23:59:59.000Z

411

Microscale Quantification of the Absorption by Dissolved and Particulate Material in Coastal Waters with an ac-9  

Science Conference Proceedings (OSTI)

Measuring coastal and oceanic absorption coefficients of dissolved and particulate matter in the visible domain usually requires a methodology for amplifying the natural signal because conventional spectrophotometers lack the necessary ...

Michael S. Twardowski; James M. Sullivan; Percy L. Donaghay; J. Ronald V. Zaneveld

1999-06-01T23:59:59.000Z

412

Pressure Swing Absorption Device and Process for Separating CO2 from Shifted Syngas and its Capture for Subsequent Storage  

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

Pressure Swing Absorption Device and Pressure Swing Absorption Device and Process for Separating CO 2 from Shifted Syngas and its Capture for Subsequent Storage Background Pulverized coal-fired power plants provide more than 50 percent of electricity needs while accounting for a third of the total carbon dioxide (CO 2 ) emissions in the United States. However, capturing CO 2 from the flue gas stream in coal-fired power plants using current commercial CO 2 capture technology could consume up

413

Development and Evaluation of a Novel Integrated Vacuum Carbonate Absorption Process  

Science Conference Proceedings (OSTI)

This project was aimed at obtaining process engineering and scale-up data at a laboratory scale to investigate the technical and economic feasibility of a patented post-combustion carbon dioxide (CO{sub 2}) capture process?the Integrated Vacuum Carbonate Absorption Process (IVCAP). Unique features of the IVCAP include its ability to be fully-integrated with the power plants steam cycle and potential for combined sulfur dioxide (SO{sub 2}) removal and CO{sub 2} capture. Theoretical and experimental studies of this project were aimed at answering three major technical questions: 1) What additives can effectively reduce the water vapor saturation pressure and energy requirement for water vaporization in the vacuum stripper of the IVCAP? 2) What catalysts can promote CO{sub 2} absorption into the potassium carbonate (PC) solution to achieve an overall absorption rate comparable to monoethanolamine (MEA) and are the catalysts stable at the IVCAP conditions and in the flue gas environment? 3) Are any process modifications needed to combine SO{sub 2} and CO{sub 2} removal in the IVCAP? Lab-scale experiments and thermodynamic and process simulation studies performed to obtain detailed information pertinent to the above three technical questions produced the following results: 1) Two additives were identified that lower the saturation pressure of water vapor over the PC solution by about 20%. 2) The carbonic anhydrase (CA) enzyme was identified as the most effective catalyst for promoting CO{sub 2} absorption. The absorption rate into the CO{sub 2}-lean PC solution promoted with 300 mg/L CA was several times slower than the corresponding 5 M MEA solution, but absorption into the CO{sub 2}-rich PC solution was comparable to the CO{sub 2}-rich MEA solution. The tested CA enzymes demonstrated excellent resistance to major flue gas impurities. A technical-grade CA enzyme was stable at 40{degrees}C (104{degrees}F) over a six-month test period, while its half-life was about two months at 50{degrees}C (122{degrees}F). Enzyme immobilization improved the CA enzymes thermal stability by up to three times compared to its free counterpart. 3) Two process modifications were proposed to improve the technical performance of the IVCAP for combined SO{sub 2} removal and CO{sub 2} capture. The results from a techno-economic study of a 528 MWe (gross) pulverized coal-fired, subcritical steam power plant revealed that the cost of CO{sub 2} avoidance with the IVCAP was about 30% lower than conventional MEA-based processes. The levelized cost of electricity (LCOE) of the IVCAP ranged from $40 to 46/MWh, an increase of 60 to 70% compared to a reference power plant without CO{sub 2} capture. The overall conclusion of this study is that the IVCAP is a technically feasible and economically more attractive process than available MEA-based processes. A scale-up study using the slipstream of an actual coal-derived flue gas and development of a more stable CA enzyme are recommended for future studies.

Lu, Yongqi; Rostam-Abadi, Massoud; Ye, Xinhuai; Zhang, Shihan; Ruhter, David; Khodayari, Arezoo; Rood, Mark

2012-04-30T23:59:59.000Z

414

NETL: Bench-Scale Development of a Hybrid Membrane-Absorption CO2 Capture  

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

Bench-Scale Development of a Hybrid Membrane-Absorption CO2 Capture Process Bench-Scale Development of a Hybrid Membrane-Absorption CO2 Capture Process Project No.: DE-FE0013118 Membrane Technology and Research (MTR) is developing and evaluating a hybrid membrane-absorption CO2 capture system. This work builds on prior DOE-funded work and combines MTR's Polaris(tm) membrane, in a low-pressure-drop, large area, plate-and-frame module, with UT Austin's piperazine (PZ) solvent and advanced, high-temperature and pressure regeneration technology. Preliminary estimates indicate that this hybrid system could lower the regeneration energy by 30 percent compared to that required with 30 weight percent monoethanolamine (MEA). MTR is evaluating two variations of the hybrid design consisting of the cross-flow Polaris membrane, which enriches flue gas to approximately 20 percent CO2, and an advanced 5 molal PZ advanced flash stripper with cold-rich bypass. The flash stripper will be optimized to take advantage of the higher CO2 concentration. In the first variation, the two systems are operated in series; in the second, the flue gas flow is split and treated by each system in parallel. The first phase of this project will include an examination of both hybrid configurations, using an integrated process model and a preliminary techno-economic assessment. In the second phase, MTR will manufacture and test a low pressure drop, large-area membrane module and UT Austin will modify their 0.1 MWe pilot plant and operate it under simulated series and parallel configurations. Based on the model and test results, the most promising configuration will be identified. In the final stage of the project, the membrane module will be integrated into the pilot plant where the fully integrated hybrid system, in its most promising cost optimized configuration, will be tested on simulated flue gas.

415

Geothermal absorption refrigeration for food processing industries. Final report, December 13, 1976--November 13, 1977  

DOE Green Energy (OSTI)

The first step in the economic analysis of the integration of geothermally powered absorption refrigeration into a food processing plant was an evaluation of the potential geothermal sites in the Western United States. The evaluation covered availability of raw materials, transportation, adequate geothermal source, labor, and other requirements for food processing plants. Several attractive geothermal sites were identified--Raft River, Idaho; Sespe Hot Springs, California; Vale Hot Springs, Oregon; Weisler-Crane Creek, Idaho; Cosco Hot Springs, California; and the Imperial Valley, California. The most economically attractive food processing industry was then matched to the site based on its particular energy, raw material, and transportation requirements. The more promising food processors identified were for frozen potato or vegetable products, freeze-dried products, and meat processing. For the refrigeration temperature range of +32/sup 0/F to -40/sup 0/F and geothermal temperature range of 212/sup 0/F to 300/sup 0/F, an absorption refrigeration system had to be identified, designed, and evaluated. Both the conventional ammonia/water and an organic absorption refrigeration system using monochlorodifluoromethane (R-22) as the refrigerant and dimethyl formamide (DMF) as the absorbent were studied. In general, only a 60/sup 0/F to 100/sup 0/F temperature drop would be effectively used for refrigeration leaving the remainder of the allowable temperature drop available for other use. The economic evaluation of the geothermal system installed in a food processing plant required the comparison of several principal alternatives. These alternatives were evaluated for three different food processing plants located at their optimum geothermal site: a forzen potato product processing plant located at Raft River, Idaho; a freeze-dried product plant located at Sespe Hot Springs, California; a beef slaughter operation located in the Imperial Valley of California. (JGB)

Harris, R.L.; Olson, G.K.; Mah, C.S.; Bujalski, J.H.

1977-11-01T23:59:59.000Z

416

Advanced cogeneration and absorption chillers potential for service to Navy bases. Final report  

SciTech Connect

The US military uses millions of Btu`s of thermal energy to heat, cool and deliver process thermal energy to buildings on military bases, much of which is transmitted through a pipeline system incorporating thousands of miles of pipe. Much of this pipeline system is in disrepair and is nearing the end of its useful life, and the boilers which supply it are old and often inefficient. In 1993, Brookhaven National Laboratory (BNL) proposed to SERDP a three-year effort to develop advanced systems of coupled diesel cogenerators and absorption chillers which would be particularly useful in providing a continuation of the services now provided by increasingly antiquated district systems. In mid-February, 1995, BNL learned that all subsequent funding for our program had been canceled. BNL staff continued to develop the Program Plan and to adhere to the requirements of the Execution Plan, but began to look for ways in which the work could be made relevant to Navy and DoD energy needs even without the extensive development plan formerly envisioned. The entire program was therefore re-oriented to look for ways in which small scale cogeneration and absorption chilling technologies, available through procurement rather than development, could provide some solutions to the problem of deteriorated district heating systems. The result is, we believe, a striking new approach to the provision of building services on military bases: in many cases, serious study should be made of the possibility that the old district heating system should be removed or abandoned, and small-scale cogenerators and absorption chillers should be installed in each building. In the remainder of this Summary, we develop the rationale behind this concept and summarize our findings concerning the conditions under which this course of action would be advisable and the economic benefits which will accrue if it is followed. The details are developed in the succeeding sections of the report.

Andrews, J.W.; Butcher, T.A.; Leigh, R.W.; McDonald, R.J.; Pierce, B.L.

1996-04-01T23:59:59.000Z

417

ON ABSORPTION BY CIRCUMSTELLAR DUST, WITH THE PROGENITOR OF SN 2012aw AS A CASE STUDY  

SciTech Connect

We use the progenitor of SN 2012aw to illustrate the consequences of modeling circumstellar dust using Galactic (interstellar) extinction laws that (1) ignore dust emission in the near-IR and beyond, (2) average over dust compositions, and (3) mischaracterize the optical/UV absorption by assuming that scattered photons are lost to the observer. The primary consequences for the progenitor of SN 2012aw are that both the luminosity and the absorption are significantly overestimated. In particular, the stellar luminosity is most likely in the range 10{sup 4.8} < L {sub *}/L {sub Sun} < 10{sup 5.0} and the star was not extremely massive for a Type IIP progenitor, with M {sub *} < 15 M {sub Sun }. Given the properties of the circumstellar dust and the early X-ray/radio detections of SN 2012aw, the star was probably obscured by an ongoing wind with M-dot {approx}10{sup -5.5} to 10{sup -5.0} M {sub Sun} yr{sup -1} at the time of the explosion, roughly consistent with the expected mass-loss rates for a star of its temperature (T{sub *} {approx_equal} 3600{sup +300} {sub -200} K) and luminosity. In the spirit of Galactic extinction laws, we supply simple interpolation formulae for circumstellar extinction by dusty graphitic and silicate shells as a function of wavelength ({lambda} {>=} 0.3 {mu}m) and total (absorption plus scattering) V-band optical depth ({tau}{sub V} {<=} 20). These do not include the contributions of dust emission, but provide a simple, physical alternative to incorrectly using interstellar extinction laws.

Kochanek, C. S.; Khan, R. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Dai, X. [Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019 (United States)

2012-11-01T23:59:59.000Z

418

WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITH NuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?  

SciTech Connect

We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain Almost-Equal-To 400-600 hard X-ray ({approx}> 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed (N{sub H} {approx}< 10{sup 24} cm{sup -2}). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N{sub H} Almost-Equal-To 7 Multiplication-Sign 10{sup 24} cm{sup -2} if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe K{alpha} line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.

Luo, B.; Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Alexander, D. M.; Hickox, R. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Harrison, F. A.; Fuerst, F.; Grefenstette, B. W.; Madsen, K. K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Bauer, F. E. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Comastri, A. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Farrah, D. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Fiore, F. [Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monteporzio Catone (Italy); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Matt, G. [Dipartimento di Matematica e Fisica, Universita degli Studi Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy); Ogle, P. [IPAC, California Institute of Technology, Mail Code 220-6, Pasadena, CA 91125 (United States); and others

2013-08-01T23:59:59.000Z

419

Local structure of indium oxynitride from x-ray absorption spectroscopy  

SciTech Connect

Synchrotron x-ray absorption near edge structures (XANES) measurements of In L{sub 3} edge is used in conjunction with first principles calculations to characterize rf magnetron sputtered indium oxynitride at different O contents. Good agreement between the measured and the independently calculated spectra are obtained. Calculations show that the XANES spectra of this alloy are sensitive to the coordination numbers of the In atoms, i.e., fourfold for indium nitride-like structures and sixfold for indium oxide-like structures, but not to the substitution of nearest neighbor N by O or vice versa.

T-Thienprasert, J.; Onkaw, D.; Rujirawat, S.; Limpijumnong, S. [School of Physics, Suranaree University of Technology and National Synchrotron Research Center, Nakhon Ratchasima 30000 (Thailand); Nukeaw, J.; Sungthong, A. [Nanotechnology Research Center of KMITL and Department of Applied Physics, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand); Porntheeraphat, S. [Thai Microelectronics Center, National Electronics and Computer Technology Center, Pathumthani 12120 (Thailand); Singkarat, S. [Fast Neutron Research Facility, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2008-08-04T23:59:59.000Z

420

Spectral energy distribution of the metagalactic ionizing radiation field from QSO absorption spectra  

E-Print Network (OSTI)

A computational procedure is presented to estimate the spectral shape of the ionizing background between 1 and 10 Ryd by analyzing optically thin absorption systems in the spectra of high redshift quasars. The procedure is based on the response surface methodology from the theory of experimental design. The shape of the recovered UV background at z~3 shows a significant intensity decrease between 3 and 4 Ryd compared to the metagalactic spectrum of Haardt & Madau (1996). This decrease is interpreted as produced by HeII Gunn-Peterson effect. There are no features indicating a contribution from galaxies to the UV background which is therefore dominated by QSOs at z~3.

I. I. Agafonova; M. Centurion; S. A. Levshakov; P. Molaro

2005-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" 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.
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421

Light trapping in a 30-nm organic photovoltaic cell for efficient carrier collection and light absorption  

E-Print Network (OSTI)

We describe surface patterning strategies that permit high photon-collection efficiency together with high carrier-collection efficiency in an ultra-thin planar heterojunction organic photovoltaic cell. Optimized designs reach up to 50% photon collection efficiency in a P3HT layer of only 30 nm, representing a 3- to 5-fold improvement over an unpatterned cell of the same thickness. We compare the enhancement of light confinement in the active layer with an ITO top layer for TE and TM polarized light, and demonstrate that the light absorption can increase by a factor of 2 due to a gap-plasmon mode in the active layer.

Tsai, Cheng-Chia; Banerjee, Ashish; Osgood, Richard M; Englund, Dirk

2012-01-01T23:59:59.000Z

422

Correlation between the Mean Matter Density and the Width of the Saturated Lyman Alpha Absorption  

E-Print Network (OSTI)

We report a scaling of the mean matter density with the width of the saturated Lyman alpha absorptions. This property is established using the ``pseudo-hydro'' technique (Croft et al. 1998). It provides a constraint for the inversion of the Lyman alpha forest, which encounters difficulty in the saturated region. With a Gaussian density profile and the scaling relation, a simple inversion of the simulated Lyman alpha forests shows that the one-dimensional mass power spectrum is well recovered on scales above 2 Mpc/h, or roughly k small scales, but improvement is possible with a more sophisticated algorithm.

Zhan, H

2003-01-01T23:59:59.000Z

423

Correlation between the Mean Matter Density and the Width of the Saturated Lyman Alpha Absorption  

E-Print Network (OSTI)

We report a scaling of the mean matter density with the width of the saturated Lyman alpha absorptions. This property is established using the ``pseudo-hydro'' technique (Croft et al. 1998). It provides a constraint for the inversion of the Lyman alpha forest, which encounters difficulty in the saturated region. With a Gaussian density profile and the scaling relation, a simple inversion of the simulated Lyman alpha forests shows that the one-dimensional mass power spectrum is well recovered on scales above 2 Mpc/h, or roughly k small scales, but improvement is possible with a more sophisticated algorithm.

Hu Zhan

2003-05-24T23:59:59.000Z

424

Triple-effect absorption refrigeration system with double-condenser coupling  

DOE Patents (OSTI)

A triple effect absorption refrigeration system is provided with a double-condenser coupling and a parallel or series circuit for feeding the refrigerant-containing absorbent solution through the high, medium, and low temperature generators utilized in the triple-effect system. The high temperature condenser receiving vaporous refrigerant from the high temperature generator is double coupled to both the medium temperature generator and the low temperature generator to enhance the internal recovery of heat within the system and thereby increase the thermal efficiency thereof.

DeVault, Robert C. (Knoxville, TN); Biermann, Wendell J. (Fayetteville, NY)

1993-01-01T23:59:59.000Z

425

Triple-effect absorption refrigeration system with double-condenser coupling  

DOE Patents (OSTI)

A triple effect absorption refrigeration system is provided with a double-condenser coupling and a parallel or series circuit for feeding the refrigerant-containing absorbent solution through the high, medium, and low temperature generators utilized in the triple-effect system. The high temperature condenser receiving vaporous refrigerant from the high temperature generator is double coupled to both the medium temperature generator and the low temperature generator to enhance the internal recovery of heat within the system and thereby increase the thermal efficiency thereof.

DeVault, R.C.; Biermann, W.J.

1993-04-27T23:59:59.000Z

426

The Cauchy problem for a quasilinear parabolic equation with gradient absorption  

SciTech Connect

The qualitative properties of solutions to the Cauchy problem for a degenerate parabolic equation containing a nonlinear operator of Baouendi-Grushin type and with gradient absorption whose density depends on time, as well as the space variables, are investigated. Bounds for the diameter of the support of the solution which are sharp with respect to time are obtained, together with its maximum. A condition which determines whether or not the phenomenon of decay to zero of the total mass of the solution occurs is discovered. Bibliography: 35 titles.

Markasheva, Vera A; Tedeev, Anatoli F [Institute of Applied Mathematics and Mechanics, Ukraine National Academy of Sciences, Donetsk (Ukraine)

2012-04-30T23:59:59.000Z

427

X-ray absorption spectroscopy studies of electrochemically deposited thin oxide films.  

DOE Green Energy (OSTI)

We have utilized ''in situ'' X-ray Absorption Fine Structure Spectroscopy to investigate the structure and composition of thin oxide films of nickel and iron that have been prepared by electrodeposition on a graphite substrate from aqueous solutions. The films are generally disordered. Structural information has been obtained from the analysis of the data. We also present initial findings on the local structure of heavy metal ions, e.g. Sr and Ce, incorporated into the electrodeposited nickel oxide films. Our results are of importance in a number of technological applications, among them, batteries, fuel cells, electrochromic and ferroelectric materials, corrosion protection, as well as environmental speciation and remediation.

Balasubramanian, M.

1998-06-02T23:59:59.000Z

428

Simple Models of Metal-Line Absorption and Emission from Cool Gas Outflows  

E-Print Network (OSTI)

Because the FeII lines are connected by optically-thin transitions to fine-structure levels, their profiles more closely reproduce the intrinsic opacity of the wind. Together these results naturally explain the absorption and emission-line characteristics observed for star-forming galaxies at zabsorption-line profiles, the surface brightness profiles offer a unique means of assessing the morphology and size of galactic-scale winds. Furthermore, the kinematics and line-ratios offer powerful diagnostics of outflows, motivating deep, spatially-extended spectroscopic observations.

Prochaska, J Xavier; Rubin, Kate

2011-01-01T23:59:59.000Z

429

A Fern Fatale - X-ray Absorption Spectroscopy Imaging an Arsenic-Loving  

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

Fern Fatale - X-ray Absorption Spectroscopy Imaging of an Arsenic-Loving Fern Fatale - X-ray Absorption Spectroscopy Imaging of an Arsenic-Loving Fern For many people, arsenic is synonymous with poison, so it is perhaps a surprise that some plants, such as the fern Pteris vittata (Figure 1) seem to quite deliberately accumulate large amounts of it. What is more, the plant converts it to the most toxic inorganic form known. How does it do this? First some background; while there is some evidence that arsenic is required for health [1], this is debatable. On the other hand, the poisonous nature of arsenic compounds was understood by the ancient Greeks and Romans, and it has been used throughout history as a homicidal and suicidal agent. It is found in two environmentally common oxy acids; arsenous acid (H3AsO3), and arsenic acid (H3AsO4), whose salts are known as arsenites and arsenates, respectively. Of these, the trivalent arsenic species are the most toxic. The infamous agent of murder is arsenic trioxide (white arsenic or As2O3), which is simply the (reputedly tasteless) anhydride of arsenous acid.

430

Time-resolved infrared absorption studies of the dynamics of radical reactions.  

Science Conference Proceedings (OSTI)

There is very little information available about the dynamics of radical+radical interactions. These processes are important in combustion being chain termination steps as well as generating new molecular species. To study these processes, a new experimental apparatus has been constructed to investigate radical-radical dynamics. The first radical or atomic species is produced with a known concentration in a microwave discharge flow system. The second is produced by pulsed laser photolysis of a suitable photolyte. The time dependence of individual rovibrational states of the product is followed by absorption of a continuous infrared laser. This approach will allow the reaction of interest to be differentiated from other radical reactions occurring simultaneously. The experimental approach is highly versatile, being able to detect a number of molecular species of particular interest to combustion processes such as water, methane, acetylene etc. at the state specific level. State specific infrared absorption coefficients of radicals can be measured in situ allowing for the determination of the absolute concentrations and hence branching ratios for reactions having multiple reaction pathways.

Macdonald, R. G. (Chemistry)

2008-01-01T23:59:59.000Z

431

Multi-Satellite Observations of Cygnus X-1 to Study the Focused Wind and Absorption Dips  

E-Print Network (OSTI)

High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray state of Cygnus X-1 is correlated with the properties of the wind which defines the environment of mass accretion. Chandra-HETGS observations close to orbital phase 0 allow for an analysis of the photoionzed stellar wind at high resolution, but because of the strong variability due to soft X-ray absorption dips, simultaneous multi-satellite observations are required to track and understand the continuum, too. Besides an earlier joint Chandra and RXTE observation, we present first results from a recent campaign which represents the best broad-band spectrum of Cyg X-1 ever achieved: On 2008 April 18/19 we observed this source with XMM-Newton, Chandra, Suzaku, RXTE, INTEGRAL, Swift, and AGILE in X- and gamma-rays, as well as with VLA in the radio. After superior conjunction of the black hole, we detect soft X-ray absorption dips likely due to clumps in the focused wind covering >95 % of the X-ray source, with column densities likely to be of several 10^23 cm^-2, which also affect photon energies above 20 keV via Compton scattering.

Manfred Hanke; Joern Wilms; Moritz Boeck; Michael A. Nowak; Norbert S. Schulz; Katja Pottschmidt; Julia C. Lee

2008-11-03T23:59:59.000Z

432

Multi-Satellite Observations of Cygnus X-1 to Study the Focused Wind and Absorption Dips  

E-Print Network (OSTI)

High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray state of Cygnus X-1 is correlated with the properties of the wind which defines the environment of mass accretion. Chandra-HETGS observations close to orbital phase 0 allow for an analysis of the photoionzed stellar wind at high resolution, but because of the strong variability due to soft X-ray absorption dips, simultaneous multi-satellite observations are required to track and understand the continuum, too. Besides an earlier joint Chandra and RXTE observation, we present first results from a recent campaign which represents the best broad-band spectrum of Cyg X-1 ever achieved: On 2008 April 18/19 we observed this source with XMM-Newton, Chandra, Suzaku, RXTE, INTEGRAL, Swift, and AGILE in X- and gamma-rays, as well as with VLA in the radio. After superior conjunction of the black hole, we detect soft X-ray absorption dips likely due to clumps in the focused wind covering >95 % of the X-ray source, with column de...

Hanke, Manfred; Boeck, Moritz; Nowak, Michael A; Schulz, Norbert S; Pottschmidt, Katja; Lee, Julia C

2008-01-01T23:59:59.000Z

433

Absorption and spectra of optical parameters in amorphous solid solutions of the Se-S system  

Science Conference Proceedings (OSTI)

A study of the optical properties of the Se-S system has revealed a correlation between the dependences of optical absorption coefficient {alpha}, effective concentration of charged defects N{sub t}, and characteristic energy E{sub 0} corresponding to the Urbach optical absorption in the spectral region where the Urbach rule works for the Se-S system on the S concentration. These optical properties are controlled by charged defects. It is shown that concentrations of intrinsic charged defects can be changed by variation in composition of the Se-S system. Reflectance spectra of amorphous solid solutions of the Se-S system are studied within the energy range 1-6 eV. Using the Kramers-Kronig method, spectral dependences of optical constants and derivative optical and dielectric functions are calculated. Variation in the spectra of optical parameters with composition of the Se-S system are explained within a cluster model in which the density of electron states is a function of atomic configurations in clusters, i.e., of the character of a short-range order.

Djalilov, N. Z.; Damirov, G. M., E-mail: gafil@phytsics.ab.az [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

2011-04-15T23:59:59.000Z

434

Simulation and performance analysis of a quadruple-effect lithium bromide-water absorption  

Science Conference Proceedings (OSTI)

In order to investigate the possibility of improving utilization of high temperature heat sources, such as natural gas, for absorption chillers, performance simulation has been conducted for a quadruple-effect lithium bromide-water cycle, capable of substantial performance improvement over state-of-the-art double-effect cycles. The system investigated includes four condensers and four desorbers coupled together, forming an extension of the conventional double-effect cycle; based on prior experience, a parallel flow system was perferred over series flow, and double-condenser coupling (DCC) was employed, extending from triple-effect cycles, to further improve performance. A modular computer code for simulation of absorption systems (ABSIM) was used to investigate the performances of the cycle. The simulation was carried out over a range of operating conditions, including investigation of the influence of some major design parameters. A coefficient of performance in the neighborhood of 2.0 (cooling) was calculated at the design point, with a heat supply temperature of 600{degrees}F at the solution outlet from the high temperature desorber. With some optimization of the weak (pumped) solution flowrate and of the solution split among the four desorbers, this COP may be raised above 2.2, without any increase in the heat transfer surface of the system`s components.

Grossman, G. [Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering; Zaltash, A.; DeVault, R.C. [Oak Ridge National Lab., TN (United States)

1994-04-01T23:59:59.000Z

435

REACTION KINETICS AND X-RAY ABSORPTION SPECTROSCOPY STUDIES OF YTTRIUM CONTAINING METAL HYDRIDE ELECTRODES  

DOE Green Energy (OSTI)

This was a study of electrode degradation mechanisms and the reaction kinetics of LaNi{sub 4.7}Sn{sub 0.3}, La{sub (1{minus}x)}, (x = 0.1, 0.2, and 0.3) and La{sub 0.7}Y{sub 0.3}Ni{sub 4.6}Sn{sub 0.3}Co{sub 0.1} metal hydride electrodes. Alloy characterization included x-ray diffraction (XRD), x-ray absorption (XAS), hydrogen absorption in a Sieverts apparatus, and electrochemical cycling of alloy electrodes. The atomic volume of H was determined for two of the alloys. Electrochemical kinetic measurements were made using steady state galvanostatic measurements, galvanodynamic sweep, and electrochemical impedance techniques. XAS was used to examine the degree of corrosion of the alloys with cycling. Alloying with Y decreased the corrosion rate. The results are consistent with corrosion inhibition by a Y containing passive film. The increase in the kinetics of the hydrogen oxidation reaction (HOR) with increasing depth of discharge was much greater on the Y containing alloys. This may be due to the dehydriding of the catalytic species on the surface of the metal hydride particles.

TICIANELLI,E.A.; MUKERJEE,S.; MCBREEN,J.; ADZIC,G.D.; JOHNSON,J.R.; REILLY,J.J.

1998-11-01T23:59:59.000Z

436

Thermal neutron absorption cross sections for igneous rocks: Newberry Caldera, Oregon  

DOE Green Energy (OSTI)

The thermal neutron absorption cross sections of geologic materials are of first-order importance to the interpretation of pulsed neutron porosity logs and of second-order importance to the interpretation of steady-state porosity logs using dual detectors. Even in the latter case, uncertainties in log response can be excessive whenever formations are encountered that possess absorption properties appreciably greater than the limestones used in most tool calibrations. These effects are of importance to logging operations directed at geothermal applications where formation vary from igneous to sedimentary and which may contain solution-deposited minerals with very large cross-section values. Most measurements of cross-section values for geologic materials have been made for hydrocarbon production applications. Hence, the specimen materials are sedimentary and clean in the sense that they are not altered by geothermal fluids. This investigation was undertaken to measure cross-section values from a sequence of igneous materials obtained from a single hole drilled in an active hydrothermal system. 3 refs., 1 fig.

Lysne, P.

1990-01-01T23:59:59.000Z

437

Solar reforming of methane in a direct absorption catalytic reactor on a parabolic dish  

DOE Green Energy (OSTI)

The concept of solar driven chemical reactions in a commercial-scale volumetric receiver/reactor on a parabolic concentrator was successfully demonstrated in the CAtalytically Enhanced Solar Absorption Receiver (CAESAR) test. Solar reforming of methane (CH{sub 4}) with carbon dioxide (CO{sub 2}) was achieved in a 64-cm diameter direct absorption reactor on a parabolic dish capable of 150 kW solar power. The reactor was a catalytic volumetric absorber consisting of a multi-layered, porous alumina foam disk coated with rhodium (Rh) catalyst. The system was operated during both steady-state and solar transient (cloud passage) conditions. The total solar power absorbed reached values up to 97 kW and the maximum methane conversion was 70%. Receiver thermal efficiencies ranged up to 85% and chemical efficiencies peaked at 54%. The absorber performed satisfactorily in promoting the reforming reaction during the tests without carbon formation. However, problems of cracking and degradation of the porous matrix, nonuniform dispersion of the Rh through the absorber, and catalyst deactivation due to sintering and possible encapsulation, must be resolved to achieve long-term operation and eventual commercialization. 17 refs., 11 figs., 1 tab.

Muir, J.F.; Hogan, R.E. Jr.; Skocypec, R.D. (Sandia National Labs., Albuquerque, NM (USA)); Buck, R. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Stuttgart (Germany, F.R.). Inst. fuer Technische Thermodynamik)

1990-01-01T23:59:59.000Z

438

Parameterization of the scattering and absorption properties of individual ice crystals  

SciTech Connect

We present parameterizations of the single-scattering properties for individual ice crystals of various habits based on the results computed from the accurate light scattering calculations. The projected area, volume, and single-scattering properties of ice crystals with various shapes and sizes are computed for 56 narrow spectral bands covering 0.2-5 {mu}m. The ice crystal habits considered in this study are hexagonal plates, solid and hollow columns, planar and spatial bullet rosette, and aggregates that are commonly observed in cirrus clouds. Using the observational relationships between the aspect ratios and the sizes of ice crystals, we can define the three-dimensional structure of these ice crystal habits with respect to their maximum dimensions for light scattering calculations. The volume and projected area of ice crystals, expressed in terms of the diameters of the corresponding equivalent spheres, are first parameterized by employing the ice crystal maximum dimensions. Further, various analytical expressions as functions of the effective dimensions of ice crystals have been developed to parameterize the extinction and absorption efficiencies, asymmetry factor, and the truncation of the forward peak energy in the phase function. The present parameterization scheme provides an efficient approach to obtain the basic scattering and absorption properties of nonspherical ice crystals. (c) 2000 American Geophysical Union.

Yang, Ping [Department of Atmospheric Sciences, University of California, Los Angeles (United States)] [Department of Atmospheric Sciences, University of California, Los Angeles (United States); Liou, K. N. [Department of Atmospheric Sciences, University of California, Los Angeles (United States)] [Department of Atmospheric Sciences, University of California, Los Angeles (United States); Wyser, Klaus [Department of Meteorology, Stockholm University, Stockholm (Sweden)] [Department of Meteorology, Stockholm University, Stockholm (Sweden); Mitchell, David [Atmospheric Sciences Center, Desert Research Institute, Reno, Nevada (United States)] [Atmospheric Sciences Center, Desert Research Institute, Reno, Nevada (United States)

2000-02-27T23:59:59.000Z

439

A method to correct IACT data for atmospheric absorption due to the Saharan Air Layer  

E-Print Network (OSTI)

Using the atmosphere as a detector volume, Imaging Air Cherenkov Telescopes (IACTs) depend highly on the properties and the condition of the air mass above the telescope. On the Canary Island of La Palma, where the Major Atmospheric Gamma-ray Imaging Cherenkov telescope (MAGIC) is situated, the Saharan Air Layer (SAL) can cause strong atmospheric absorption affecting the data quality and resulting in a reduced gamma flux. To correlate IACT data with other measurements, e.g. long-term monitoring or Multi-Wavelength (MWL) studies, an accurate flux determination is mandatory. Therefore, a method to correct the data for the effect of the SAL is needed. Three different measurements of the atmospheric absorption are performed on La Palma. From the determined transmission, a correction factor is calculated and applied to the MAGIC data. The different transmission measurements from optical and IACT data provide comparable results. MAGIC data of PG 1553+113, taken during a MWL campaign in July 2006, have been analyzed using the presented method, providing a corrected flux measurement for the study of the spectral energy distribution of the source.

Daniela Dorner; Kari Nilsson; Thomas Bretz

2008-08-02T23:59:59.000Z

440

Life Cycle cost Analysis of Waste Heat Operated Absorption Cooling Systems for Building HVAC Applications  

E-Print Network (OSTI)

In this paper, life cycle cost analysis (LCCA) of waste heat operated vapour absorption air conditioning system (VARS) incorporated in a building cogeneration system is presented and discussed. The life cycle cost analysis (LCCA) based on present worth cost (PWC) method, which covers the initial costs, operating costs, maintenance costs, replacement costs and salvage values is the useful tool to merit various cooling and power generation systems for building applications. A life cycle of 23 years was used to calculate the PWC of the system for annual operating hours of 8760 and the same is compared with the electric based vapour compression chiller (VCRS) of same capacity. The life cycle cost (LCC) of waste heat operated absorption chiller is estimated to be US $ 1.5 million which is about 71.5 % low compared to electric powered conventional vapour compression chiller. From the analysis it was found that the initial cost of VARS system was 125 % higher than that of VCRS, while the PWC of operating cost of VARS was 78.2 % lower compared to VCRS. The result shows that the waste heat operated VARS would be preferable from the view point of operating cost and green house gas emission reduction.

Saravanan, R.; Murugavel, V.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol absorption absorption" from the National Library of EnergyBeta (NLEBeta).
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441

A comparison of eight solar-driven absorption cooling systems in the National Solar Data Network  

Science Conference Proceedings (OSTI)

Large solar driven cooling systems of the absorption chiller type offer opportunities to apply solar energy to the air conditioning of buildings with the attendant savings in conventional energy resources. Many complex design problems are encountered in the attempt to implement this technology. For instance, the range of readily available solar installation operating temperatures is at the low end of the required range for effective operation of the chillers. A study has been made of eight such systems which were operated in a variety of climates during the 1980 cooling season and instrumented within the National Solar Data Network (NSDN). Presented here are summary results of this study. Considerably more detail on the performance of these systems is contained in the reference along with a brief discussion of absorption chillers and their application in solar designs. The performance of the monitored installations was not very good. Only two systems showed energy savings and they were insignificant considering the size of the buildings. Nevertheless valuable lessons were learned from the study. Each system had some desirable design features. Taking these features together, a projected composite system was posited which would have performed fairly well. Suggestions are presented which should lead to more effective designs for this type of renewable energy application.

Kelly, C.J.; Logee, T.L.

1982-01-01T23:59:59.000Z

442

THE PHYSICAL CONDITIONS OF THE INTRINSIC N V NARROW ABSORPTION LINE SYSTEMS OF THREE QUASARS  

SciTech Connect

We employ detailed photoionization models to infer the physical conditions of intrinsic narrow absorption line systems found in high-resolution spectra of three quasars at z = 2.6-3.0. We focus on a family of intrinsic absorbers characterized by N V lines that are strong relative to the Ly{alpha} lines. The inferred physical conditions are similar for the three intrinsic N V absorbers, with metallicities greater than 10 times the solar value (assuming a solar abundance pattern), and with high ionization parameters (log U {approx} 0). Thus, we conclude that the unusual strength of the N V lines results from a combination of partial coverage, a high ionization state, and high metallicity. We consider whether dilution of the absorption lines by flux from the broad emission line region can lead us to overestimate the metallicities and we find that this is an unlikely possibility. The high abundances that we infer are not surprising in the context of scenarios in which metal enrichment takes place very early on in massive galaxies. We estimate that the mass outflow rate in the absorbing gas (which is likely to have a filamentary structure) is less than a few M{sub sun} yr{sup -1} under the most optimistic assumptions, although it may be embedded in a much hotter, more massive outflow.

Wu Jian; Charlton, Jane C.; Misawa, Toru; Eracleous, Michael [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Ganguly, Rajib, E-mail: jwu@astro.psu.ed, E-mail: misawatr@shinshu-u.ac.j [Department of Computer Science, Engineering, and Physics, University of Michigan-Flint, 213 Murchie Science Building, 303 Kearsley Street, Flint, MI 48502 (United States)

2010-10-20T23:59:59.000Z

443

Ground-state ammonia and water in absorption towards Sgr B2  

E-Print Network (OSTI)

We have used the Odin submillimetre-wave satellite telescope to observe the ground state transitions of ortho-ammonia and ortho-water, including their 15N, 18O, and 17O isotopologues, towards Sgr B2. The extensive simultaneous velocity coverage of the observations, >500 km/s, ensures that we can probe the conditions of both the warm, dense gas of the molecular cloud Sgr B2 near the Galactic centre, and the more diffuse gas in the Galactic disk clouds along the line-of-sight. We present ground-state NH3 absorption in seven distinct velocity features along the line-of-sight towards Sgr B2. We find a nearly linear correlation between the column densities of NH3 and CS, and a square-root relation to N2H+. The ammonia abundance in these diffuse Galactic disk clouds is estimated to be about (0.5-1)e-8, similar to that observed for diffuse clouds in the outer Galaxy. On the basis of the detection of H218O absorption in the 3 kpc arm, and the absence of such a feature in the H217O spectrum, we conclude that the water...

Wirstrm, E S; Black, J H; Hjalmarson, ; Larsson, B; Olofsson, A O H; Encrenaz, P J; Falgarone, E; Frisk, U; Olberg, M; Sandqvist, Aa

2010-01-01T23:59:59.000Z

444

Lyman ? Absorption as a Sensitive Probe of the H I Column in Cooling Flows  

E-Print Network (OSTI)

Abstract. X-ray spectra of a significant fraction of cooling flow (CF) clusters of galaxies indicate the presence of large columns of cold absorbing gas. The physical nature of the absorbing medium remains a mystery. Searches for H I absorption using the 21 cm hyperfine structure line yielded null results in most cases. The purpose of this contribution is to point out that the Lyman ? absorption cross section is ? 10 7 times larger than for the 21 cm line, it can therefore be used as a very sensitive probe of the H I column in clusters, and can thus place stringent constraints on the nature of the X-ray absorber. This method is applied to the Perseus CF cluster where a medium resolution ( ? 250 km s ?1) UV spectrum is available. The upper limit on the H I column obtained using Lyman ? is at least ? 50 times smaller than the 21 cm detection, and ? 5,000 smaller than implied by X-ray spectra, indicating that the X-ray absorber is exceedingly devoid of H I. Higher resolution UV spectra with HST may improve the H I column limits by an additional factor of ? 4,000. This method can be applied to strongly constrain the nature of the X-ray absorbing medium in a significant fraction of CF clusters.

A. Laor

1996-01-01T23:59:59.000Z

445

Performance Modeling of a Solar Driven Absorption Cooling System for Carnegie Mellon University's Intelligent Workplace  

E-Print Network (OSTI)

The Robert L. Preger Intelligent Workplace (IW) is a 650 m2 (7,000 ft2) living laboratory of office space at Carnegie Mellon University (Pittsburgh, PA). The IW is involved in a project to develop, install, and test an effective solar thermal system for space heating and cooling. The proposed energy supply system configuration includes integrated compound parabolic concentrator (ICPC), a hot storage tank, a gas fired auxiliary heater, a steam generator, a steam driven absorption chiller and fan coils. A TRNSYS predictive model has been programmed and used to evaluate the performance of the system throughout a summer season. The effects on performance and on costs have been explored for various design variables and operating conditions. The performance calculations indicate that: - the 16.17 kW (55.2 kBtu/hr, 4.5 tons) absorption chiller is adequate to meet the IW south cooling requirements - 30-40m2 collectors can supply from 55 to 65% of the heat required to drive the chiller - estimated heat losses from the system can reach about 20-30% of the total heat collected.

Masson, S. V.; Qu, M.; Archer, D. H.

2006-01-01T23:59:59.000Z

446

Lyman $?$ Absorption as a Sensitive Probe of the H I Column in Cooling Flows  

E-Print Network (OSTI)

X-ray spectra of a significant fraction of cooling flow (CF) clusters of galaxies indicate the presence of a large column of ``cold'' absorbing gas. The physical nature of the absorbing medium remains a mystery. Searches for H I absorption using the 21 cm hyperfine structure line yielded null results in most cases. The purpose of this contribution is to point out that the Lyman $\\alpha$ absorption cross section is ~10^7 times larger than for the 21 cm line, it can therefore be used as a very sensitive probe of the H I column in clusters, and can thus place stringent constraints on the nature of the X-ray absorber. This method is applied to the Perseus CF cluster where a medium resolution (~250 km/s) UV spectrum is available. The upper limit on the H I column obtained using Lyman $\\alpha$ is at least ~50 times smaller than the 21 cm detection, and ~5,000 smaller than implied by X-ray spectra, indicating that the X-ray absorber is exceedingly devoid of H I. Higher resolution UV spectra with HST may improve the H I column limits by an additional factor of ~4,000. This method can be applied to strongly constrain the nature of the X-ray absorbing medium in a significant fraction of CF clusters .

Ari Laor

1996-09-24T23:59:59.000Z

447

The Nature of Interstellar Gas toward the Pleiades Revealed in Absorption Lines  

E-Print Network (OSTI)

We present high-resolution, high signal to noise absorption-line observations of CN, Ca II, Ca I, CH^+, and CH along twenty lines of sight toward members of the Pleiades. The acquired data enable the most detailed study to date of the interaction between cluster stars and the surrounding interstellar gas. Total equivalent widths are consistent with previous investigations except where weaker features are detected owing to our greater sensitivity. Mean b-values for the molecular species indicate that toward most of the Pleiades CH is associated with the production of CH^+ rather than CN. An analysis of radial velocities reveals a kinematic distinction between ionized atomic gas and molecular and neutral gas. Molecular components are found with velocities in the local standard of rest of either ~ +7 km s^-1 or ~ +9.5 km s^-1, with the higher-velocity components associated with the strongest absorption. Atomic gas traced by Ca II shows a strong central component at v_LSR ~ +7 km s^-1 exhibiting velocity gradients indicative of cloud-cluster interactions. Gas density estimates derived from measured CH/CH^+ column density ratios show good agreement with those inferred from H_2 rotational populations, yielding typical values of n ~ 50 cm^-3. Our models do not include the important time-dependent effects on CH^+ formation which may ultimately be needed to extract physical conditions in these clouds.

A. M. Ritchey; M. Martinez; K. Pan; S. R. Federman; D. L. Lambert

2006-06-27T23:59:59.000Z

448

Exciton and biexciton signatures in femotosecond transient absorption of {pi}-conjugated oligomers  

Science Conference Proceedings (OSTI)

The authors report femotosecond transient-absorption studies of a five-ring oligomer of polyphenylenevinylene (PPV) prepared in two different forms: as solid-state films and dilute solutions. Both types of samples exhibit a photoinduced absorption (PA) band with dynamics which closely match those of the stimulated emission (SE), demonstrating unambiguously that these features originate from the same species, namely from intrachain singlet excitons. Photo-chemical degradation of the solid-state samples is demonstrated to dramatically shorten the SE dynamics above a moderate incident pump fluence, whereupon the dynamics of the SE and the long-wavelength PA no longer coincide. In contrast to solutions, solid-state films exhibit an additional short-wavelength PA band with pump-independent dynamics, indicating the efficient formation of non-emissive inter-chain excitons. Correlations in the subpicosecond dynamics of the two PA features, as well as the pump intensity-dependence provide strong evidence that the formation of inter-chain excitons is mediated by intrachain two-exciton states. At high pump levels, the authors see a clear indication of interaction between excited states also in dilute solutions. This is manifested as a superlinear pump-dependence and shortening of the decay dynamics of the SE. They attribute this behavior to the formation of biexcitons resulting from coherent interaction between two excitons on a single chain.

Klimov, V.; McBranch, D. [Los Alamos National Lab., NM (United States); Barashkov, N.; Ferraris, J. [Univ. of Texas, Dallas, TX (United States)

1997-10-01T23:59:59.000Z

449

Absorption-Line Spectroscopy of Planetary Nebulae with FUSE: Probing the Molecular, Atomic, and Ionized Gas  

E-Print Network (OSTI)

The central stars of planetary nebulae (PNe) are natural targets for FUSE due to their UV brightness. The FUSE spectra of many PNe show absorption features due to circumstellar material in species ranging from H_2 and neutrals in the photodissociation region (PDR) to ions resident in the H II region. We report results from a program designed to search for nebular components in the H_2 Lyman and Werner resonance lines that are responsible for the fluorescent excitation of H_2 in strong FUV radiation fields. Our failure to detect H_2 in absorption in several PNe with strong near-infrared H_2 emission indicates that the molecular material has an asymmetrical or clumpy distribution. We also detect enrichments in the s-process product Ge, find that Fe is not depleted into dust along at least one line of sight through a PN, and show that starlight fluorescence can affect the populations of the excited fine-structure levels of O I.

Dinerstein, H L; Bowers, C W; Dinerstein, Harriet L.; Bowers, Charles W.

2004-01-01T23:59:59.000Z

450

Absorption-Line Spectroscopy of Planetary Nebulae with FUSE: Probing the Molecular, Atomic, and Ionized Gas  

E-Print Network (OSTI)

The central stars of planetary nebulae (PNe) are natural targets for FUSE due to their UV brightness. The FUSE spectra of many PNe show absorption features due to circumstellar material in species ranging from H_2 and neutrals in the photodissociation region (PDR) to ions resident in the H II region. We report results from a program designed to search for nebular components in the H_2 Lyman and Werner resonance lines that are responsible for the fluorescent excitation of H_2 in strong FUV radiation fields. Our failure to detect H_2 in absorption in several PNe with strong near-infrared H_2 emission indicates that the molecular material has an asymmetrical or clumpy distribution. We also detect enrichments in the s-process product Ge, find that Fe is not depleted into dust along at least one line of sight through a PN, and show that starlight fluorescence can affect the populations of the excited fine-structure levels of O I.

Harriet L. Dinerstein; N. C. Sterling; Charles W. Bowers

2004-10-25T23:59:59.000Z

451

The Nature of Interstellar Gas toward the Pleiades Revealed in Absorption Lines  

E-Print Network (OSTI)

We present high-resolution, high signal to noise absorption-line observations of CN, Ca II, Ca I, CH^+, and CH along twenty lines of sight toward members of the Pleiades. The acquired data enable the most detailed study to date of the interaction between cluster stars and the surrounding interstellar gas. Total equivalent widths are consistent with previous investigations except where weaker features are detected owing to our greater sensitivity. Mean b-values for the molecular species indicate that toward most of the Pleiades CH is associated with the production of CH^+ rather than CN. An analysis of radial velocities reveals a kinematic distinction between ionized atomic gas and molecular and neutral gas. Molecular components are found with velocities in the local standard of rest of either ~ +7 km s^-1 or ~ +9.5 km s^-1, with the higher-velocity components associated with the strongest absorption. Atomic gas traced by Ca II shows a strong central component at v_LSR ~ +7 km s^-1 exhibiting velocity gradient...

Ritchey, A M; Pan, K; Federman, S R; Lambert, D L

2006-01-01T23:59:59.000Z

452

Aerosol Observing System (AOS) Handbook  

Science Conference Proceedings (OSTI)

The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earths radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

Jefferson, A

2011-01-17T23:59:59.000Z

453

HELIUM IN NATAL H II REGIONS: THE ORIGIN OF THE X-RAY ABSORPTION IN GAMMA-RAY BURST AFTERGLOWS  

SciTech Connect

Soft X-ray absorption in excess of Galactic is observed in the afterglows of most gamma-ray bursts (GRBs), but the correct solution to its origin has not been arrived at after more than a decade of work, preventing its use as a powerful diagnostic tool. We resolve this long-standing problem and find that absorption by He in the GRB's host H II region is responsible for most of the absorption. We show that the X-ray absorbing column density (N{sub H{sub X}}) is correlated with both the neutral gas column density and with the optical afterglow's dust extinction (A{sub V} ). This correlation explains the connection between dark bursts and bursts with high N{sub H{sub X}} values. From these correlations, we exclude an origin of the X-ray absorption which is not related to the host galaxy, i.e., the intergalactic medium or intervening absorbers are not responsible. We find that the correlation with the dust column has a strong redshift evolution, whereas the correlation with the neutral gas does not. From this, we conclude that the column density of the X-ray absorption is correlated with the total gas column density in the host galaxy rather than the metal column density, in spite of the fact that X-ray absorption is typically dominated by metals. The strong redshift evolution of N{sub H{sub X}}/A{sub V} is thus a reflection of the cosmic metallicity evolution of star-forming galaxies and we find it to be consistent with measurements of the redshift evolution of metallicities for GRB host galaxies. We conclude that the absorption of X-rays in GRB afterglows is caused by He in the H II region hosting the GRB. While dust is destroyed and metals are stripped of all of their electrons by the GRB to great distances, the abundance of He saturates the He-ionizing UV continuum much closer to the GRB, allowing it to remain in the neutral or singly-ionized state. Helium X-ray absorption explains the correlation with total gas, the lack of strong evolution with redshift, as well as the absence of dust, metal or hydrogen absorption features in the optical-UV spectra.

Watson, Darach; Andersen, Anja C.; Fynbo, Johan P. U.; Hjorth, Jens; Kruehler, Thomas; Laursen, Peter; Leloudas, Giorgos; Malesani, Daniele [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Zafar, Tayyaba [Laboratoire d'Astrophysique de Marseille - LAM, Universite Aix-Marseille and CNRS, UMR 7326, 38 rue F. Joliot-Curie, F-13388, Marseille Cedex 13 (France); Gorosabel, Javier [Instituto de Astrofisica de Andalucia (IAA-CSIC), Glorieta de la Astronomia s/n, E-18008, Granada (Spain); Jakobsson, Pall, E-mail: darach@dark-cosmology.dk [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland)

2013-05-01T23:59:59.000Z

454

Modular Simulation of Absorption Systems User's Guide (Windows Version 5.0)  

SciTech Connect

ABSIM (an acronym for ABsorption SIMulation) is a user-oriented computer code designed for the simulation of absorption systems at steady state, in both flexible and modular form. ABSIM makes it possible to investigate various cycle configurations with different working fluids, to calculate their operating parameters, to predict their performance and to compare them with each other on a uniform basis. A graphical user interface enables the user to draw the cycle diagram on the computer screen, enter data interactively, run the program and view the results either in the form of a table or superimposed on the cycle diagram. Special utilities enable the user to plot the results and produce a pressure-temperature-concentration (P-T-X) diagram of the cycle. Most absorption systems consist of a number of standard components or units (e.g., absorber, condenser) that may be combined in different forms to produce various cycles. Recognizing this, ABSIM has been structured around unit subroutines, each of which contains the governing equations for the particular unit. These subroutines are activated by a main program that interprets the input for the cycle, calls the units, and links them to each other in an order corresponding to the user's specification to form the complete system. Each unit subroutine, when activated, addresses a property database for the thermodynamic properties of the working fluids. The equations generated by the code are listed and solved simultaneously by a mathematical solver routine. The code requires relatively simple inputs, consisting of the minimum information needed to define an absorption system properly. After drawing the cycle in terms of the units recognizable by the code and showing their interconnections, the user must specify the size of each exchange unit in terms of its heat and mass transfer characteristics, the working fluid(s) at each state point; and the given operating conditions, such as temperatures, flowrates, and the like, fixed at specific state points. Based on this information, the program calculates the temperature, flowrate, concentration, pressure, and the vapor fraction at each state point in the system and the heat duty at each unit, from which the coefficient of performance may be determined. ABSIM has been used successfully to simulate a variety of single-, double- and triple-stage absorption chillers, heat pumps and heat transformers using the working fluids LiBr-H{sub 2}O, H{sub 2}ONH{sub 3}, LiBr/H{sub 2}O-NH{sub 3}, LiBr/ZnBr{sub 2}-CH{sub 3}OH and more. Some of these results will be described briefly in Sect. 8. Eleven absorption fluids are presently available in the code's property database, and 12 units are available to compose practically every absorption cycle of interest. The code in its present form may be used not only to evaluate new cycles and working fluids, but also to investigate a system's behavior in off-design conditions, to analyze experimental data, and to perform preliminary design optimization. This user manual is organized into eight sections and two appendices. The remainder of this section describes the background for the ABSIM code and presents its special features in comparison with other simulation codes. Section 2 contains information on installation of the code and on basic operations for the first-time user. Section 3 describes the structure of the code, including the input, the output, and the main program. Section 4 describes the unit subroutines containing the governing equations for the 12 unit modules of the code. Section 5 reviews the property database that contains the thermodynamic properties of the working fluids. Section 6 describes the solver package and the method of solution for the equations generated by the code. Section 7 instructs the user on how to use the graphical interface. Some results of the simulation are described in Sect. 8. Appendix A is an input manual describing in detail each item in the input, its significance, and its format. Appendix B contains cycle diagrams and input and output files for se

Grossman, G

2000-09-25T23:59:59.000Z

455

Aerosol Properties and Chemical Apportionment of Aerosol Optical Depth at Locations off the U.S. East Coast in July and August 2001  

Science Conference Proceedings (OSTI)

Airborne in situ measurements of vertical profiles of the aerosol light scattering coefficient, light absorption coefficient, and single scattering albedo (?0) are presented for locations off the East Coast of the United States in JulyAugust ...

Brian I. Magi; Peter V. Hobbs; Thomas W. Kirchstetter; Tihomir Novakov; Dean A. Hegg; Song Gao; Jens Redemann; Beat Schmid

2005-04-01T23:59:59.000Z

456

Absorption Spectroscopy in Hollow-Glass Waveguides Using Infrared Diode Lasers[4817-25  

Science Conference Proceedings (OSTI)

Near- and mid-infrared diode lasers combined with flexible, hollow waveguides hold the promise of light weight, field portable, fast response gas sensors. The advantages of using the waveguides compared to White or Herriott multireflection cells include a small gas volume, a high photon fill factor in the waveguide, which increases molecule-light interactions, and reduction or elimination of optical fringing, which usually sets the practical limit of detectivity in absorption spectroscopy. Though hollow waveguides have been commercially available for several years, relatively few results have been reported in the literature. We present here results from our laboratory where we have injected infrared laser light into straight and coiled lengths of hollow waveguides and performed direct and wavelength modulated absorption spectroscopy on nitrous oxide, ethylene, and nitric oxide. Using a 1 mm bore, 3 meter long coiled waveguide coated for the near infrared, nitrous oxide transitions near 6595 cm-1 were observed under flowing conditions. Signal-to-noise ratios on the order of 1500:1 with RMS noise equal to 2 X 10-5 were measured. In the mid-infrared light from either a 10.1 or 5.3 micron lead salt diode laser was injected into a three meter length of 1 mm bore hollow waveguide coated for the mid-infrared. The waveguide was coiled with one loop at a diameter of 52 cm. Ethylene transitions were observed in the vicinity of 985 cm-1 with a static fill of 0.2 Torr of pure ethylene in the waveguide and nitric oxide transitions were observed in the vicinity of 1906 cm-1 using either a flow or a static fill of 1 ppm NO in nitrogen. In direct absorption the NO transitions are observed to have a signal-to-noise of approximately 5:1 for transitions with absorbances on the order of 10-3. Using wavelength modulated techniques the signal-to-noise ratio improves at least an order of magnitude. These encouraging results indicate that waveguides can be used for in situ gas monitoring.

Blake, Thomas A. (BATTELLE (PACIFIC NW LAB)); Kelly, James F. (BATTELLE (PACIFIC NW LAB)); Stewart, Timothy L. (BATTELLE (PACIFIC NW LAB)); Hartman, John S. (BATTELLE (PACIFIC NW LAB)); Sharpe, Steven W. (BATTELLE (PACIFIC NW LAB)); Sams, Robert L. (BATTELLE (PACIFIC NW LAB)); Alan Fried

2002-11-01T23:59:59.000Z

457

QUASARS PROBING QUASARS. IV. JOINT CONSTRAINTS ON THE CIRCUMGALACTIC MEDIUM FROM ABSORPTION AND EMISSION  

Science Conference Proceedings (OSTI)

We have constructed a sample of 29 close projected quasar pairs where the background quasar spectrum reveals absorption from optically thick H I gas associated with the foreground quasar. These unique sightlines allow us to study the quasar circumgalactic medium (CGM) in absorption and emission simultaneously, because the background quasar pinpoints large concentrations of gas where Ly{alpha} emission, resulting from quasar-powered fluorescence, resonant Ly{alpha} scattering, and/or cooling radiation, is expected. A sensitive search (1{sigma} surface-brightness limits of SB{sub Ly{alpha}}{approx_equal}3 Multiplication-Sign 10{sup -18} erg s{sup -1} cm{sup -2} arcsec{sup -2}) for diffuse Ly{alpha} emission in the environments of the foreground (predominantly radio-quiet) quasars is conducted using Gemini/GMOS and Keck/LRIS slit spectroscopy. We fail to detect large-scale {approx}100 kpc Ly{alpha} emission, either at the location of the optically thick absorbers or in the foreground quasar halos, in all cases except a single system. We interpret these non-detections as evidence that the gas detected in absorption is shadowed from the quasar UV radiation due to obscuration effects, which are frequently invoked in unified models of active galactic nuclei. Small-scale R {approx} 50 A) Ly{alpha}-emitter with luminosity L{sub Ly{alpha}} = 2.1 {+-} 0.32 Multiplication-Sign 10{sup 41} erg s{sup -1} at small impact parameter R = 134 kpc from one foreground quasar, and argue that it is more likely to result from quasar-powered fluorescence, than simply be a star-forming galaxy clustered around the quasar. Our observations imply that much deeper integrations with upcoming integral-field spectrometers such as MUSE and KCWI will be able to routinely detect a diffuse Ly{alpha} glow around bright quasars on scales R {approx} 100 kpc and thus directly image the CGM.

Hennawi, Joseph F.; Prochaska, J. Xavier, E-mail: xavier@ucolick.org [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)

2013-03-20T23:59:59.000Z

458

IMPROVED AND QUALITY-ASSESSED EMISSION AND ABSORPTION LINE MEASUREMENTS IN SLOAN DIGITAL SKY SURVEY GALAXIES  

Science Conference Proceedings (OSTI)

We present a new database of absorption and emission-line measurements based on the entire spectral atlas from the Sloan Digital Sky Survey (SDSS) 7th data release of galaxies within a redshift of 0.2. Our work makes use of the publicly available penalized pixel-fitting (pPXF) and gas and absorption line fitting (gandalf) IDL codes, aiming to improve the existing measurements for stellar kinematics, the strength of various absorption-line features, and the flux and width of the emissions from different species of ionized gas. Our fit to the stellar continuum uses both standard stellar population models and empirical templates obtained by combining a large number of stellar spectra in order to fit a subsample of high-quality SDSS spectra for quiescent galaxies. Furthermore, our fit to the nebular spectrum includes an exhaustive list of both recombination and forbidden lines. Foreground Galactic extinction is implicitly treated in our models, whereas reddening in the SDSS galaxies is included in the form of a simple dust screen component affecting the entire spectrum that is accompanied by a second reddening component affecting only the ionized gas emission. In order to check for systematic departures from the rather standard set of assumptions that enters our models, we provide a quality assessment for our fit to the SDSS spectra in our sample, for both the stellar continuum and the nebular emissions and across different wavelength regions. This quality assessment also allows the identification of objects with either problematic data or peculiar features. We hope to foster the discovery potential of our database; therefore, our spectral fit is available to the community. For example, based on the quality assessment around the H{alpha} and [N II] {lambda}6584 lines, approximately 1% of the SDSS spectra classified as 'galaxies' by the SDSS pipeline do in fact require additional broad lines to be matched, even though they do not show a strong continuum from an active nucleus, as do the SDSS objects classified as 'quasars'. Finally, we provide new spectral templates for galaxies of different Hubble types, obtained by combining the results of our spectral fit for a subsample of 452 morphologically selected objects.

Oh, Kyuseok; Yi, Sukyoung K. [Department of Astronomy, Yonsei University, Seoul 120-749 (Korea, Republic of); Sarzi, Marc [Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Schawinski, Kevin, E-mail: yi@yonsei.ac.kr [Yale Center for Astronomy and Astrophysics, Yale University, P.O. Box 208121, New Haven, CT 06511 (United States)

2011-08-01T23:59:59.000Z

459

X-ray absorption spectroscopy of aluminum z-pinch plasma with tungsten backlighter planar wire array source  

Science Conference Proceedings (OSTI)

Absorption features from K-shell aluminum z-pinch plasmas have recently been studied on Zebra, the 1.7 MA pulse power generator at the Nevada Terawatt Facility. In particular, tungsten plasma has been used as a semi-backlighter source in the generation of aluminum K-shell absorption spectra by placing a single Al wire at or near the end of a single planar W array. All spectroscopic experimental results were recorded using a time-integrated, spatially resolved convex potassium hydrogen phthalate (KAP) crystal spectrometer. Other diagnostics used to study these plasmas included x-ray detectors, optical imaging, laser shadowgraphy, and time-gated and time-integrated x-ray pinhole imagers. Through comparisons with previous publications, Al K-shell absorption lines are shown to be from much lower electron temperature ({approx}10-40 eV) plasmas than emission spectra ({approx}350-500 eV).

Osborne, G. C.; Kantsyrev, V. L.; Safronova, A. S.; Esaulov, A. A.; Weller, M. E.; Shrestha, I.; Shlyaptseva, V. V. [Physics Department, University of Nevada, Reno, Reno, Nevada 89557 (United States); Ouart, N. D. [Naval Research Laboratory, Washington, D.C. 20375 (United States)

2012-10-15T23:59:59.000Z

460

Extracting interstellar diffuse absorption bands from cool star spectra: Application to bulge clump giants in Baade's window  

E-Print Network (OSTI)

Interstellar diffuse bands are usually extracted from hot star spectra because they are characterized by smooth continua. It introduces a strong limitation on the number of available targets, and reduces potential studies of the IS matter and the use of absorptions for cloud mapping. We have developed a new automatic fitting method appropriate to interstellar absorptions in spectra of cool stars that possess stellar atmospheric parameters. We applied this method to the extraction of three DIBs in high resolution VLT FLAMES/GIRAFFE spectra of red clump stars from the bulge. By combining all stellar synthetic spectra, HITRAN-LBLRTM atmospheric transmission spectra and diffuse band empirical absorption profiles, we determine the 6196, 6204, and 6284 A DIB strength toward the 219 target stars and discuss the sources of uncertainties. In order to test the sensitivity of the DIB extraction, we intercompare the three results and compare the DIB equivalent widths with the reddening derived from an independent extinct...

Chen, Hui-Chen; Babusiaux, Carine; Puspitarini, Lucky; Bonifacio, Piercarlo; Hill, Vanessa

2012-01-01T23:59:59.000Z

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461

Interplay between multiple scattering, emission, and absorption of light in the phosphor of a white light-emitting diode  

E-Print Network (OSTI)

We study light transport in phosphor plates of white light-emitting diodes (LEDs). We measure the broadband diffuse transmission through phosphor plates of varying YAG:Ce$^{3+}$ density. We distinguish the spectral ranges where absorption, scattering, and re-emission dominate. Using diffusion theory, we derive the transport and absorption mean free paths from first principles. We find that both transport and absorption mean free paths are on the order of the plate thickness. This means that phosphors in commercial LEDs operate well within an intriguing albedo range around 0.7. We discuss how salient parameters that can be derived from first principles control the optical properties of a white LED.

Leung, V Y F; Tukker, T W; Mosk, A P; IJzerman, W L; Vos, W L

2013-01-01T23:59:59.0