Determining window solar heat gain coefficient
Harrison, S.J.; Wonderen, S.J. van . Solar Calorimetry Lab.)
1994-08-01
The solar heat gain characteristics of fenestration systems impact daytime building energy performance, occupant comfort and utility load demands. A measure of the fraction of available solar energy entering a building interior per unit window area is defined as the solar heat gain coefficient (SHGC). Together with a window's thermal transmittance (U-value), the SHGC is used to compare fenestration products, and it allows for the calculation of energy rating number and annual energy performance. The need to measure and compared advances in window technology has led to the development of experimental and analytical methods for the determination of SHGC performance. Several test facilities currently or previously capable of performing SHGC measurements exist worldwide. Results experimentally determined using these facilities have provided design data for handbook tables, and have been instrumental in the development and validation of predictive analytical methods and computer simulation tools. However, these facilities have operated without a standard test procedure for SHGC performance. Consequently, recent efforts have been focused on developing consensus test procedures for the evaluation of window energy performance.
McKisson, John E.; Barbosa, Fernando
2015-09-01
A method for designing a completely passive bias compensation circuit to stabilize the gain of multiple pixel avalanche photo detector devices. The method includes determining circuitry design and component values to achieve a desired precision of gain stability. The method can be used with any temperature sensitive device with a nominally linear coefficient of voltage dependent parameter that must be stabilized. The circuitry design includes a negative temperature coefficient resistor in thermal contact with the photomultiplier device to provide a varying resistance and a second fixed resistor to form a voltage divider that can be chosen to set the desired slope and intercept for the characteristic with a specific voltage source value. The addition of a third resistor to the divider network provides a solution set for a set of SiPM devices that requires only a single stabilized voltage source value.
Evaluation of solar heat gain coefficient for solar-control glazings and shading devices
Harrison, S.J.; Wonderen, S.J. van
1998-10-01
The determination of solar heat gain coefficient (SHGC) values for complex fenestration systems is required to evaluate building energy performance, to estimate peak electrical loads, and to ensure occupant comfort. In the past, simplified techniques have been used to calculate the values of SHGC for fenestration systems. As glazing systems that incorporate complex geometries become more common, test methods are required to evaluate these products and to aid in the development of new computational tools. Recently, a unique facility and test method for the experimental determination of SHGC values were developed and demonstrated for simple fenestration systems. The study described in this paper further applies this method to a variety of commercially available glazing and shading systems (e.g., heat-absorbing insulated glazing units (IGUs), reflective film and suspended film IGUs), and shading devices (i.e., slat blinds and shades). Testing was conducted in a solar simulator facility using a specially designed window calorimeter. The results of this study demonstrate the feasibility of the solar simulator-based test method for the evaluation of SHGC values for solar-control glazings and shading devices.
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
... (not first class) on international flights (business class ... pilot programs that include "GAIN SHARING" principles. ... ATTN: Customer Relations If you wish to discuss this report ...
Storage Resource Unit (SRU) Formula Coefficients
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Formula Coefficients Storage Resource Unit (SRU) Formula Coefficients The coefficients in the Storage Resource Unit (SRU) formula were arrived at from the following considerations:...
Harold Gaines | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
As far back as he can remember, Harold Gaines has had an interest in electronics. "I'm not exactly sure what really triggered that interest in electronics, but it was there," he said. To view a larger version of the image, click on it. As far back as he can remember, Harold Gaines has had an interest in electronics. "I'm not exactly sure what really triggered that interest in electronics, but it was there," he said. To view a larger version of the image, click on it. Harold
α -cluster asymptotic normalization coefficients for nuclear...
Office of Scientific and Technical Information (OSTI)
-cluster asymptotic normalization coefficients for nuclear astrophysics Citation Details In-Document Search Title: -cluster asymptotic normalization coefficients for nuclear ...
Linda Gaines | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Linda Gaines Transportation System Analyst News Idle hands: New and improved IdleBox tool to aid in reduction of idling E-mail lgaines@anl.gov Publications View Publications Projects Idle Reduction Publications Idle Reduction Research Idle Reduction Tools and Outreach Materials Lithium-Ion Battery Recycling Publications Lithium-Ion Battery Recycling and Life Cycle Analysis Reducing Vehicle Idling
Fuel Temperature Coefficient of Reactivity
Loewe, W.E.
2001-07-31
A method for measuring the fuel temperature coefficient of reactivity in a heterogeneous nuclear reactor is presented. The method, which is used during normal operation, requires that calibrated control rods be oscillated in a special way at a high reactor power level. The value of the fuel temperature coefficient of reactivity is found from the measured flux responses to these oscillations. Application of the method in a Savannah River reactor charged with natural uranium is discussed.
Photomultiplier tube gain regulating system
Johnson, Wayne F.
1976-01-01
This invention relates to an improved system for regulating the gain of a photomultiplier tube, and was designed for use with the photomultiplier tubes of a GeMSAEC fast analyzers. It has the following advantages over the prior system: noise is virtually eliminated; sample analysis can begin after 3 to 4 revolutions of the rotor; fluorescent and light scattering solutions can be used as a reference; and the reference solution can be in any cuvette on the rotor.
Transport coefficients of gluonic fluid
Das, Santosh K.; Alam, Jan-e
2011-06-01
The shear ({eta}) and bulk ({zeta}) viscous coefficients have been evaluated for a gluonic fluid. The elastic, gg{yields}gg and the inelastic, number nonconserving, gg{yields}ggg processes have been considered as the dominant perturbative processes in evaluating the viscous coefficients to entropy density (s) ratios. Recently the processes: gg{yields}ggg has been revisited and a correction to the widely used Gunion-Bertsch (GB) formula has been obtained. The {eta} and {zeta} have been evaluated for gluonic fluid with the formula recently derived. At large {alpha}{sub s} the value of {eta}/s approaches its lower bound, {approx}1/4{pi}.
Conductivities and Seebeck Coefficients of Boron Carbides:'...
Office of Scientific and Technical Information (OSTI)
Coefficients of Boron Carbides: ''Softening-Bipolaron'' Hopping Citation Details In-Document Search Title: Conductivities and Seebeck Coefficients of Boron Carbides: ...
Portable vapor diffusion coefficient meter
Ho, Clifford K.
2007-06-12
An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.
Students gain work experience at WIPP
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Students Gain Work Experience at WIPP CARLSBAD, N.M., January 10, 2000 -- Students from two Eddy County high schools are gaining valuable experience by spending time with employees...
Insight Gained from Simplified Dynamic Analysis
Broader source: Energy.gov [DOE]
Insight Gained from Simplified Dynamic Analysis ... or Everything Old is New Again October 21, 2014 Greg Mertz Consultant
Determination of optimal gains for constrained controllers
Kwan, C.M.; Mestha, L.K.
1993-08-01
In this report, we consider the determination of optimal gains, with respect to a certain performance index, for state feedback controllers where some elements in the gain matrix are constrained to be zero. Two iterative schemes for systematically finding the constrained gain matrix are presented. An example is included to demonstrate the procedures.
SCALE Continuous-Energy Eigenvalue Sensitivity Coefficient Calculations
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Perfetti, Christopher M.; Rearden, Bradley T.; Martin, William R.
2016-02-25
Sensitivity coefficients describe the fractional change in a system response that is induced by changes to system parameters and nuclear data. The Tools for Sensitivity and UNcertainty Analysis Methodology Implementation (TSUNAMI) code within the SCALE code system makes use of eigenvalue sensitivity coefficients for an extensive number of criticality safety applications, including quantifying the data-induced uncertainty in the eigenvalue of critical systems, assessing the neutronic similarity between different critical systems, and guiding nuclear data adjustment studies. The need to model geometrically complex systems with improved fidelity and the desire to extend TSUNAMI analysis to advanced applications has motivated the developmentmore » of a methodology for calculating sensitivity coefficients in continuous-energy (CE) Monte Carlo applications. The Contributon-Linked eigenvalue sensitivity/Uncertainty estimation via Tracklength importance CHaracterization (CLUTCH) and Iterated Fission Probability (IFP) eigenvalue sensitivity methods were recently implemented in the CE-KENO framework of the SCALE code system to enable TSUNAMI-3D to perform eigenvalue sensitivity calculations using continuous-energy Monte Carlo methods. This work provides a detailed description of the theory behind the CLUTCH method and describes in detail its implementation. This work explores the improvements in eigenvalue sensitivity coefficient accuracy that can be gained through the use of continuous-energy sensitivity methods and also compares several sensitivity methods in terms of computational efficiency and memory requirements.« less
LED Efficacy: What America Stands to Gain
Broader source: Energy.gov (indexed) [DOE]
diode) lighting technology have been realized in the past decade, as evidenced by the high-performing products now gaining share in growing numbers of lighting market ...
Gaines Cavern Wind Project | Open Energy Information
ess":"","icon":"","group":"","inlineLabel":"","visitedicon":"" References "AWEA-US-Wind-Industry-Market-Reports" Retrieved from "http:en.openei.orgwindex.php?titleGaine...
Gaining creative control over semiconductor nanowires
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Gaining creative control over semiconductor nanowires Using a microfluidic reactor, Los ... Using a microfluidic reactor, Los Alamos researchers transformed the SLS process into a ...
CHOW,WENG W.; JONES,ERIC D.; MODINE,NORMAND A.; KURTZ,STEVEN R.; ALLERMAN,ANDREW A.
2000-05-23
The optical gain spectra for GaInNAs/GaAs quantum wells are computed using a microscopic laser theory. From these spectra, the peak gain and carrier radiative decay rate as functions of carrier density are determined. These dependences allow the study of the lasing threshold current density of GaInNAs/GaAs quantum well structures.
LED Efficacy: What America Stands to Gain | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Efficacy: What America Stands to Gain LED Efficacy: What America Stands to Gain LED Efficacy-What America Stands to Gain_ November 2015.pdf (280.37 KB)
A new method for predicting the solar heat gain of complex fenestration systems
Klems, J.H.; Warner, J.L.
1992-10-01
A new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorptances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient. This method has been used to determine the solar heat gain coefficient of a double-glazed window with an interior white shade. The resulting solar heat gain coefficient was compared to a direct measurement of the same system using the Mobile Window Thermal Test (MoWiTT) Facility for measuring window energy performance, and the two results agreed. This represents the first in a series of planned validations and applications of the new method.
Engine improvement and efficiency gained by teamwork
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Engine improvement and efficiency gained by teamwork Engine improvement and efficiency gained by teamwork Together, Cummins and LANL have reduced costs and increased efficiency in diesel engines. April 3, 2012 Engine for R&D Research and development (R&D) efforts focus on improving engine efficiency while meeting future federal and state emissions regulations through a combination of: combustion technologies that minimize in-cylinder formation of emissions ...the company realized a more
Code System to Calculate Correlation & Regression Coefficients.
Energy Science and Technology Software Center (OSTI)
1999-11-23
Version 00 PCC/SRC is designed for use in conjunction with sensitivity analyses of complex computer models. PCC/SRC calculates the partial correlation coefficients (PCC) and the standardized regression coefficients (SRC) from the multivariate input to, and output from, a computer model.
Reducing gain shifts in photomultiplier tubes
Cohn, Charles E.
1976-01-01
A means is provided for reducing gain shifts in multiplier tubes due to varying event count rates. It includes means for limiting the number of cascaded, active dynodes of the multiplier tube to a predetermined number with the last of predetermined number of dynodes being the output terminal of the tube. This output is applied to an amplifier to make up for the gain sacrificed by not totally utilizing all available active stages of the tube. Further reduction is obtained by illuminating the predetermined number of dynodes with a light source of such intensity that noise appearing at the output dynode associated with the illumination is negligible.
Method and system for edge cladding of laser gain media
Bayramian, Andrew James; Caird, John Allyn; Schaffers, Kathleen Irene
2014-03-25
A gain medium operable to amplify light at a gain wavelength and having reduced transverse ASE includes an input surface and an output surface opposing the input surface. The gain medium also includes a central region including gain material and extending between the input surface and the output surface along a longitudinal optical axis of the gain medium. The gain medium further includes an edge cladding region surrounding the central region and extending between the input surface and the output surface along the longitudinal optical axis of the gain medium. The edge cladding region includes the gain material and a dopant operable to absorb light at the gain wavelength.
Sensitivity of fenestration solar gain to source spectrum and angle of incidence
McCluney, W.R.
1996-12-31
The solar heat gain coefficient (SHGC) is the fraction of solar radiant flux incident on a fenestration system entering a building as heat gain. In general it depends on both the angle of incidence and the spectral distribution of the incident solar radiation. In attempts to improve energy performance and user acceptance of high-performance glazing systems, manufacturers are producing glazing systems with increasing spectral selectivity. This poses potential difficulties for calculations of solar heat gain through windows based upon the use of a single solar spectral weighting function. The sensitivity of modern high-performance glazing systems to both the angle of incidence and the shape of the incident solar spectrum is examined using a glazing performance simulation program. It is found that as the spectral selectivity of the glazing system increases, the SHGC can vary as the incident spectral distribution varies. The variations can be as great as 50% when using several different representative direct-beam spectra. These include spectra having low and high air masses and a standard spectrum having an air mass of 1.5. The variations can be even greater if clear blue diffuse skylight is considered. It is recommended that the current broad-band shading coefficient method of calculating solar gain be replaced by one that is spectral based.
Enhancing optical gains in Si nanocrystals via hydrogenation...
Office of Scientific and Technical Information (OSTI)
Variable stripe length technique was used to obtain gains. At 0.3 Wcmsup 2 pumping power density of pulsed laser, net gains were observed together with gain enhancements after ...
Loss/gain on ignition test report
Winstead, M.L.
1996-01-10
Document provides the results of tests done on Product Cans from the HC-21C sludge stabilization process. Tests included running a simulated Thermogravimetric Analysis, TGA, on the processed material that have received Loss On Ignition (LOI) sample results that show a gain on ignition or a high LOI and reprocessing product cans with high LOIs. Also, boat material temperatures in the furnace were tracked during the testing.
Effects of Gain Changes on RPM Performance
Lousteau, Angela L; York, Robbie Lynn; Livesay, Jake
2012-03-01
The mission of the U.S. Department of Energy/National Nuclear Security Administration's (DOE/NNSA's) Office of the Second Line of Defense (SLD) is to strengthen the capability of foreign governments to deter, detect, and interdict the illicit trafficking of special nuclear and other radioactive materials across international borders and through the global maritime shipping system. The goal of this mission is to reduce the probability of these materials being fashioned into a weapon of mass destruction or radiological dispersal device that could be used against the United States or its international partners. This goal is achieved primarily through the installation and operation of radiation detection equipment at border crossings, airports, seaports, and other strategic locations around the world. In order to effectively detect the movement of radioactive material, the response of these radiation detectors to various materials in various configurations must be well characterized. Oak Ridge National Laboratory (ORNL) investigated two aspects of Radiation Portal Monitor (RPM) settings, based on a preliminary investigation done by the Los Alamos National Laboratory (LANL): source-to-detector distance effect on amplifier gain and optimized discriminator settings. This report discusses this investigation. A number of conclusions can be drawn from the ORNL testing. First, for increased distance between the source and the detector, thus illuminating the entire detector rather than just the center of the detector (as is done during detector alignments), an increase in gain may provide a 5-15% increase in sensitivity (Fig. 4). However, increasing the gain without adjusting the discriminator settings is not recommended as this makes the monitor more sensitive to electronic noise and temperature-induced fluctuations. Furthermore, if the discriminators are adjusted in relation to the increase in gain, thus appropriately discriminating against electronic noise, the sensitivity
Diffusion and transport coefficients in synthetic opals
Sofo, J. O.; Mahan, G. D.; Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200
2000-07-15
Opals are structures composed of close-packed spheres in the size range of nano to micrometers. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the thermal and electrical conductivity is used to estimate the transport coefficients of opal structures as a function of the neck size and the mean free path of the carriers. The theory presented is also applicable to the diffusion problem in other periodic structures. (c) 2000 The American Physical Society.
Shear viscosity coefficient of liquid lanthanides
Patel, H. P. Thakor, P. B. Prajapati, A. V.; Sonvane, Y. A.
2015-05-15
Present paper deals with the computation of shear viscosity coefficient (η) of liquid lanthanides. The effective pair potential v(r) is calculated through our newly constructed model potential. The Pair distribution function g(r) is calculated from PYHS reference system. To see the influence of local field correction function, Hartree (H), Tailor (T) and Sarkar et al (S) local field correction function are used. Present results are compared with available experimental as well as theoretical data. Lastly, we found that our newly constructed model potential successfully explains the shear viscosity coefficient (η) of liquid lanthanides.
Gratings for Increasing Solid-State Laser Gain and Efficiency
Erlandson, A C; Britten, J A; Bonlie, J D
2010-04-16
We introduce new concepts for increasing the efficiency of solid state lasers by using gratings deposited on laser slabs or disks. The gratings improve efficiency in two ways: (1) by coupling out of the slab deleterious amplified spontaneous emission (ASE) and (2) by increasing the absorption efficiency of pump light. The gratings also serve as antireflective coatings for the extracting laser beam. To evaluate the potential for such coatings to improve laser performance, we calculated optical properties of a 2500 groove/mm, tantala-silica grating on a 1cm x 4cm x 8cm titanium-doped sapphire slab and performed ray-trace calculations for ASE and pump light. Our calculations show substantial improvements in efficiency due to grating ASE-coupling properties. For example, the gratings reduce pump energy required to produce a 0.6/cm gain coefficient by 9%, 20% and 35% for pump pulse durations of 0.5 {micro}s, 1{micro}s and 3{micro}s, respectively. Gratings also increase 532-nm pump-light absorption efficiency, particularly when the product slab overall absorption is small. For example, when the single-pass absorption is 1 neper, absorption efficiency increases from 66%, without gratings, to 86%, when gratings are used.
Semiconductor radiation detector with internal gain
Iwanczyk, Jan; Patt, Bradley E.; Vilkelis, Gintas
2003-04-01
An avalanche drift photodetector (ADP) incorporates extremely low capacitance of a silicon drift photodetector (SDP) and internal gain that mitigates the surface leakage current noise of an avalanche photodetector (APD). The ADP can be coupled with scintillators such as CsI(Tl), NaI(Tl), LSO or others to form large volume scintillation type gamma ray detectors for gamma ray spectroscopy, photon counting, gamma ray counting, etc. Arrays of the ADPs can be used to replace the photomultiplier tubes (PMTs) used in conjunction with scintillation crystals in conventional gamma cameras for nuclear medical imaging.
Compensated gain control circuit for buck regulator command charge circuit
Barrett, David M.
1996-01-01
A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit.
Compensated gain control circuit for buck regulator command charge circuit
Barrett, D.M.
1996-11-05
A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit. 5 figs.
Measurement of the iodine partition coefficient
Furrer, M.; Cripps, R.C.; Gubler, R.
1985-08-01
The hydrolysis of iodine is complicated because it involves a number of species that differ considerably in their individual volatilities. Large uncertainties exist in the thermodynamic data of some of the iodine species, especially at temperatures above 25C. Because of this, an experiment was undertaken to measure the partition coefficient under varying physical and chemical conditions. Measurements of P were made for a temperature range of 21 to 113C under well-defined conditions (liquid molar concentration, pH, and redox potential) for inorganic iodine. The experimental results are interpreted with the aid of an analytical model and published thermodynamic data. A good agreement between calculated and measured values was found. The experimental setup allows the determination of very high partition coefficients up to a value of 2.0 X 10W. This is demonstrated by adding cesium-iodide to the fuel pool water of a boiling water reactor.
Coefficients of thermal expansiion of common encapsulants
Adolf, D.B.
1988-07-01
The coefficient of thermal expansion (CTE) of common electronic encapsulating polymers were measured over the temperature range of /minus/ 50/degree/C to approximately 120/degree/C. CTE's are presented for these systems as continuous functions of temperature in contrast to previous measurements. Comparison between the historical '' property chart'' CTE's and those obtained in this study are made when possible. The procedures used in this study are presented in detail so that, unlike the property chart, users will fully understand the accuracy and limitations of these values. 27 figs., 5 tabs.
Bounds on Transport Coefficients of Porous Media
Berryman, J G
2005-03-21
An analytical formulation of conductivity bounds by Bergman and Milton is used in a different way to obtain rigorous bounds on the real transport coefficients (electrical conductivity, thermal conductivity, and/or fluid permeability) of a fluid-saturated porous medium. These bounds do not depend explicitly on the porosity, but rather on two formation factors--one associated with the pore space and the other with the solid frame. Hashin-Shtrikman bounds for transport in random polycrystals of porous-material laminates will also be discussed.
CONSTRUCTION OF KEY CLEANUP PROJECT GAINS GOOD GROUND AT SRS...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
CONSTRUCTION OF KEY CLEANUP PROJECT GAINS GOOD GROUND AT SRS CONSTRUCTION OF KEY CLEANUP PROJECT GAINS GOOD GROUND AT SRS June 1, 2010 - 12:00pm Addthis CONSTRUCTION OF KEY CLEANUP ...
Klems, J.H.
2000-08-01
The computational methods for calculating the properties of glazing systems containing shading from the properties of their components have been developed, but the measurement standards and property data bases necessary to apply them have not. It is shown that with a drastic simplifying assumption these methods can be used to calculate system solar-optical properties and solar heat gain coefficients for arbitrary glazing systems, while requiring limited data about the shading. Detailed formulas are presented, and performance multipliers are defined for the approximate treatment of simple glazings with shading. As higher accuracy is demanded, the formulas become very complicated.
Progress toward high-gain laser fusion
Storm, E.
1988-09-28
A 1985-1986 Review of the US inertial confinement fusion program by the National Academy of Sciences concluded that five more years might be required to obtain enough data to determine the future course of the program. Since then, data from the Nova laser and from the Halite/Centurion program have resolved most of the outstanding problems identified by the NAS review. In particular, we now believe that we can produce a sufficiently uniform target; that we can keep the energy content in hot electrons and high-energy photons low enough (/approximately/1--10% of drive energy, depending on target design) and achieve enough pulse-shaping accuracy (/approximately/10%, with a dynamic range of 100:1) to keep the fuel on a near-Fermi-degenerate adiabat; that we can produce an /approximately/100-Mbar pressure pulse of sufficient uniformity (/approximately/1%), and can we control hydrodynamic instabilities so that the mix of the pusher into the hot spot is low enough to permit marginal ignition. These results are sufficiently encouraging that the US Department of Energy is planning to complete a 10-MJ laboratory microfusion facility to demonstrate high-gain ICF in the laboratory within a decade. 22 refs., 1 fig.
Caterpillar and Cummins Gain Edge Through Argonnne's Rare Computer...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Caterpillar and Cummins Gain Edge Through Argonnne's Rare Computer Modeling and Analysis Resources PDF icon catcumminscomputingsuccessstorydec2015...
Mechanism of the metallic metamaterials coupled to the gain material
Huang, Zhixiang; Droulias, Sotiris; Koschny, Thomas; Soukoulis, Costas M.
2014-10-11
We present evidence of strong coupling between the gain material and the metallic metamaterials. It is of vital importance to understand the mechanism of the coupling of metamaterials with the gain medium. Using a four-level gain system, the numerical pump-probe experiments are performed in several configurations (splitring resonators (SRRs), inverse SRRs and fishnets) of metamaterials, demonstrating reduction of the resonator damping in all cases and hence the possibility for loss compensation. We find that the differential transmittance ?T/T can be negative in different SRR configurations, such as SRRs on the top of the gain substrate, gain in the SRR gap and gain covering the SRR structure, while in the fishnet metamaterial with gain ?T/T is positive.
Mechanism of the metallic metamaterials coupled to the gain material
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Huang, Zhixiang; Droulias, Sotiris; Koschny, Thomas; Soukoulis, Costas M.
2014-10-11
We present evidence of strong coupling between the gain material and the metallic metamaterials. It is of vital importance to understand the mechanism of the coupling of metamaterials with the gain medium. Using a four-level gain system, the numerical pump-probe experiments are performed in several configurations (splitring resonators (SRRs), inverse SRRs and fishnets) of metamaterials, demonstrating reduction of the resonator damping in all cases and hence the possibility for loss compensation. We find that the differential transmittance ?T/T can be negative in different SRR configurations, such as SRRs on the top of the gain substrate, gain in the SRR gapmoreand gain covering the SRR structure, while in the fishnet metamaterial with gain ?T/T is positive.less
Stirling cycle simulation without differential coefficients
Organ, A.J.
1995-12-31
With a simple transformation, the gas processes in the Stirling machine are described for all time and location in an algebraic equation free of differential coefficients of the unknowns. Local instantaneous heat transfer and friction are represented in function of local instantaneous Reynolds number, N{sub re}. The method avoids problems of numerical discretization, stability, convergence, artificial dispersion and diffusion. The paper presents the algebra of the transformation. Specimen solutions cover the temperature field of the gas circuit (exchangers and regenerator) over a representative cycle. When programmed for workstation the core code occupies some 2 dozen lines, and processing calls for seconds of CPU time. Availability of the solution means that intimate details of the gas processes are susceptible to examination using the most basic of computing facilities.
Critical Materials Institute Gains Ten Industrial and Research Affiliates |
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Department of Energy Critical Materials Institute Gains Ten Industrial and Research Affiliates Critical Materials Institute Gains Ten Industrial and Research Affiliates April 12, 2016 - 10:32am Addthis News release from the Ames Laboratory, April 11, 2016. The Critical Materials Institute, a U.S. Department of Energy Innovation Hub led by the Ames Laboratory, has gained ten new affiliates to its research program, seeking ways to eliminate and reduce reliance on rare-earth metals and other
Use of a photonic crystal for optical amplifier gain control
Lin, Shawn-Yu; Fleming, James G.; El-Kady, Ihab
2006-07-18
An optical amplifier having a uniform gain profile uses a photonic crystal to tune the density-of-states of a gain medium so as to modify the light emission rate between atomic states. The density-of-states of the gain medium is tuned by selecting the size, shape, dielectric constant, and spacing of a plurality of microcavity defects in the photonic crystal. The optical amplifier is particularly useful for the regeneration of DWDM signals in long optical fibers.
USDA Global Agricultural Information Network (GAIN) | Open Energy...
Agriculture Information Network (GAIN) provides timely information on the agricultural economy, products and issues in foreign countries since 1995 that are likely to have an...
Material gain: Research a step toward more efficient solar panels |
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
MIT-Harvard Center for Excitonics Material gain: Research a step toward more efficient solar panels 10.7.2014
Ames Laboratory-developed titanium powder processing gains internation...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
processing gains international customer base Contacts: For release: Dec. 7, 2015 Iver Anderson, Division of Materials Sciences and Engineering, 515-294-9791 Steve Karsjen, Public...
Goodyear Tire Plant Gains Traction on Energy Savings After Completing...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Goodyear operates more than 60 facilities in 26 countries, including the Union City, Tennessee, plant pictured above. Goodyear Tire Plant Gains Traction on Energy Savings After ...
Efficient surface plasmon amplification in gain-assisted silver nanotubes and associated dimers
Yu, HaiQun; Jiang, ShuMin; Wu, DaJian
2015-04-21
SPASER (surface plasmon amplification by stimulated emission of radiation) properties in active SiO{sub 2}Ag nanotubes and associated dimers have been investigated by using the scattering theory and the finite element method. In the active Ag nanotube, as the gain coefficient of the core increases to a critical value, a super-resonance occurs. The SPASER phenomenon also can be found in the active Ag nanotube dimer. The strong couplings between two nanotubes lead to larger gain threshold for the active Ag nanotube dimer compared with the active Ag nanotube. At the super-resonance, the maximal surface enhanced Raman scattering factor at the hot spot in the active Ag nanotube dimer can achieve about 8??10{sup 18}, which is large enough for single molecule detection. Furthermore, with increasing the separation between two Ag nanotubes, the gain threshold value for the super-resonance of the active Ag nanotube dimer decreases, while the corresponding super-resonance wavelength increases first and then decreases.
Scanning measurement of Seebeck coefficient of a heated sample
Snyder, G. Jeffrey; Iwanaga, Shiho
2016-04-19
A novel scanning Seebeck coefficient measurement technique is disclosed utilizing a cold scanning thermocouple probe tip on heated bulk and thin film samples. The system measures variations in the Seebeck coefficient within the samples. The apparatus may be used for two dimensional mapping of the Seebeck coefficient on the bulk and thin film samples. This technique can be utilized for detection of defective regions, as well as phase separations in the sub-mm range of various thermoelectric materials.
Scale dependence of sorption coefficients for contaminant transport...
Office of Scientific and Technical Information (OSTI)
fractured rock Citation Details In-Document Search Title: Scale dependence of sorption coefficients for contaminant transport in saturated fractured rock You are ...
Scale dependence of sorption coefficients for contaminant transport...
Office of Scientific and Technical Information (OSTI)
fractured rock Citation Details In-Document Search Title: Scale dependence of sorption coefficients for contaminant transport in saturated fractured rock No abstract prepared. ...
Temperature coefficients for PV modules and arrays: Measurement...
Office of Scientific and Technical Information (OSTI)
The term temperature coefficient has been applied to several different photovoltaic ... Resource Relation: Conference: 26. IEEE photovoltaic specialists conference, Anaheim, CA ...
TEMPERATURE COEFFICIENTS FOR PV MODULES AND ARRAYS: MEASUREMENT...
Office of Scientific and Technical Information (OSTI)
ASTM also specifies that temperature coefficients are determined using a standard solar ... fixture, illuminating the cell with a solar simulator, measuring the cell's ...
Diffusion coefficient of three-dimensional Yukawa liquids
Dzhumagulova, K. N.; Ramazanov, T. S.; Masheeva, R. U.
2013-11-15
The purpose of this work is an investigation of the diffusion coefficient of the dust component in complex plasma. The computer simulation of the Yukawa liquids was made on the basis of the Langevin equation, which takes into account the influence of buffer plasma on the dust particles dynamics. The GreenKubo relation was used to calculate the diffusion coefficient. Calculations of the diffusion coefficient for a wide range of the system parameters were performed. Using obtained numerical data, we constructed the interpolation formula for the diffusion coefficient. We also show that the interpolation formula correctly describes experimental data obtained under microgravity conditions.
Isopiestic Determination of the Osmotic and Activity Coefficients...
Office of Scientific and Technical Information (OSTI)
model with an ionic-strength dependent third virial coefficient, as well as those of ... Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 58 ...
Predicting Local Transport Coefficients at Solid-Gas Interfaces...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the predictability of the coefficient quantifying this local process, the surface permeability , by means of a two-scale simulation approach. Methane tracer-release from the...
Absolute Time-Resolved X-Ray Laser Gain Measurement
Mocek, T.; Sebban, S.; Zeitoun, Ph.; Faivre, G.; Hallou, A.; Rousseau, J.P.; Maynard, G.; Cros, B.; Fajardo, M.; Kazamias, S.; Dubau, J.; Aubert, D.; Lacheze-Murel, G. de
2005-10-21
We present the first direct measurement of the time evolution of the gain of a soft x-ray laser amplifier. The measurement is based on the injection of a seed pulse, obtained by high-order harmonic generation, into an x-ray laser medium. Strong amplification occurs when the seed pulse is synchronized with the gain period. By precisely varying the delay between the x-ray laser plasma creation and the seed pulse injection, the actual temporal evolution of the soft x-ray amplifier gain is obtained with a subpicosecond resolution.
Fresnel reflection from a cavity with net roundtrip gain
Mansuripur, Tobias S.; Mansuripur, Masud
2014-03-24
A planewave incident on an active etalon with net roundtrip gain may be expected to diverge in field amplitude, yet applying the Fresnel formalism to Maxwell's equations admits a convergent solution. We describe this solution mathematically and provide additional insight by demonstrating the response of such a cavity to an incident beam of light. Cavities with net roundtrip gain have often been overlooked in the literature, and a clear understanding of their behavior yields insight to negative refraction in nonmagnetic media, a duality between loss and gain, amplified total internal reflection, and the negative-index lens.
Big performance gains at NERSC hack-a-thon
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Optimization hack-a-thon Big performance gains at NERSC hack-a-thon February 27, 2015 by Jack Deslippe & Richard Gerber At this year's NERSC user group meeting we tried something...
Review of health and productivity gains from better IEQ
Fisk, William J.
2000-08-01
The available scientific data suggest that existing technologies and procedures can improve indoor environmental quality (IEQ) in a manner that significantly increases productivity and health. While there is considerable uncertainty in the estimates of the magnitudes of productivity gains that may be obtained, the projected gains are very large. For the U.S., the estimated potential annual savings and productivity gains are $6 to $14 billion from reduced respiratory disease, $2 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance that are unrelated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment.
Two energy technology projects from Los Alamos gain DOE funding
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Energy technology projects gain DOE funding Two energy technology projects from Los Alamos gain DOE funding Funding to help businesses move promising energy technologies from DOE's National Laboratories to the marketplace. June 21, 2016 This first department-wide round of funding through the Technology Commercialization Fund (TCF) will support 54 projects at 12 national labs involving 52 private-sector partners. This first department-wide round of funding through the Technology Commercialization
Hewlett Packard Labs Gains Insights with Innovative ALS Research Tools
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Hewlett Packard Labs Gains Insights with Innovative ALS Research Tools Hewlett Packard Labs Gains Insights with Innovative ALS Research Tools Print Thursday, 05 May 2016 11:21 For the past eight years, Hewlett Packard Labs, the central research organization of Hewlett Packard Enterprise (HPE), has been using cutting-edge ALS techniques to advance some of their most promising technological research. Hewlett Packard Labs researchers, including Suhas Kumar, Catherine Graves, and John Paul Strachan,
Army Veteran Gains Experience at EM Site | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Army Veteran Gains Experience at EM Site Army Veteran Gains Experience at EM Site May 29, 2014 - 12:00pm Addthis Army Capt. Mark Spurlock is photographed while stationed in Afghanistan. Army Capt. Mark Spurlock is photographed while stationed in Afghanistan. Army Capt. Mark Spurlock Army Capt. Mark Spurlock Army Capt. Mark Spurlock is photographed while stationed in Afghanistan. Army Capt. Mark Spurlock AIKEN, S.C. - Army Capt. Mark Spurlock supports the EM program at the Savannah River Site as
Internships Help Future Energy Leaders Gain Hands-On Experience |
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Department of Energy Internships Help Future Energy Leaders Gain Hands-On Experience Internships Help Future Energy Leaders Gain Hands-On Experience August 23, 2013 - 10:19am Addthis EM Office of External Affairs Acting Communications Director Dave Borak talks with EM intern Valerie Edwards. | Photo courtesy of the Energy Department. EM Office of External Affairs Acting Communications Director Dave Borak talks with EM intern Valerie Edwards. | Photo courtesy of the Energy Department. Rebecca
Micro- and macroscale coefficients of friction of cementitious materials
Lomboy, Gilson; Sundararajan, Sriram; Wang, Kejin
2013-12-15
Millions of metric tons of cementitious materials are produced, transported and used in construction each year. The ease or difficulty of handling cementitious materials is greatly influenced by the material friction properties. In the present study, the coefficients of friction of cementitious materials were measured at the microscale and macroscale. The materials tested were commercially-available Portland cement, Class C fly ash, and ground granulated blast furnace slag. At the microscale, the coefficient of friction was determined from the interaction forces between cementitious particles using an Atomic Force Microscope. At the macroscale, the coefficient of friction was determined from stresses on bulk cementitious materials under direct shear. The study indicated that the microscale coefficient of friction ranged from 0.020 to 0.059, and the macroscale coefficient of friction ranged from 0.56 to 0.75. The fly ash studied had the highest microscale coefficient of friction and the lowest macroscale coefficient of friction. -- Highlights: •Microscale (interparticle) coefficient of friction (COF) was determined with AFM. •Macroscale (bulk) COF was measured under direct shear. •Fly ash had the highest microscale COF and the lowest macroscale COF. •Portland cement against GGBFS had the lowest microscale COF. •Portland cement against Portland cement had the highest macroscale COF.
New recommended heat gains for commercial cooking equipment
Fisher, D.R.
1998-12-31
Radiant heat gain from cooking equipment can significantly impact the air-conditioning load and/or human comfort in a commercial kitchen. This paper presents and discusses updated heat gain data for several types of commercial cooking equipment based on recent testing by gas and electric utility research organizations. The cooking equipment was tested under exhaust-only, wall-canopy hoods. The fundamentals of appliance heat gain are reviewed and the new data are compared with data published in the 1993 ASHRAE Handbook--Fundamentals, chapter 26, nonresidential cooling and heating load calculations. These updated data are now incorporated in the 1997 ASHRAE Handbook--Fundamentals, chapter 28, nonresidential cooling and heating load calculations. The paper also discusses appliance heat gain with respect to sizing air-conditioning systems for commercial kitchens and presents representative radiant factors that may be used to estimate heat gain from other sizes or types of gas and electric cooking equipment when appliance specific heat gain data are not avoidable.
A new method for predicting the solar heat gain of complex fenestration systems
Klems, J.H.; Warner, J.L.; Kelley, G.O.
1995-03-01
A new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorbances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient. The method has been applied to one of the most optically complex systems in common use, a venetian blind in combination with multiple glazings. A comparison between the scanner-based calculation method and direct system calorimetric measurements made on the LBL MoWiTT facility showed good agreement, and is a significant validation of the method accuracy and feasibility.
Klems, Joseph H.
2001-03-01
The computational methods for calculating the properties of glazing systems containing shading from the properties of their components have been developed, but the measurement standards and property data bases necessary to apply them have not. It is shown that with a drastic simplifying assumption these methods can be used to calculate system solar-optical properties and solar heat gain coefficients for arbitrary glazing systems, while requiring limited data about the shading. Detailed formulas are presented, and performance multipliers are defined for the approximate treatment of simple glazings with shading. As higher accuracy is demanded, the formulas become very complicated.
Seal assembly for materials with different coefficients of thermal expansion
Minford, Eric
2009-09-01
Seal assembly comprising (a) two or more seal elements, each element having having a coefficient of thermal expansion; and (b) a clamping element having a first segment, a second segment, and a connecting segment between and attached to the first and second segments, wherein the two or more seal elements are disposed between the first and second segments of the clamping element. The connecting segment has a central portion extending between the first segment of the clamping element and the second segment of the clamping element, and the connecting segment is made of a material having a coefficient of thermal expansion. The coefficient of thermal expansion of the material of the connecting segment is intermediate the largest and smallest of the coefficients of thermal expansion of the materials of the two or more seal elements.
ORISE: Dose Coefficients for Intakes of Radionuclides via Contaminated
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Wounds Dose Coefficients for Intakes of Radionuclides via Contaminated Wounds Dose coefficients for 38 radionuclides based on NCRP Wound Model and ICRP biokinetic models This report is intended to assist health physics and medical staff in more rapidly assessing the potential dosimetric consequences of a contaminated wound. The National Council on Radiation Protection and Measurements Wound Model describing the retention of selected radionuclides at the site of a contaminated wound and their
Higher order matrix differential equations with singular coefficient matrices
Fragkoulis, V. C.; Kougioumtzoglou, I. A.; Pantelous, A. A.; Pirrotta, A.
2015-03-10
In this article, the class of higher order linear matrix differential equations with constant coefficient matrices and stochastic process terms is studied. The coefficient of the highest order is considered to be singular; thus, rendering the response determination of such systems in a straightforward manner a difficult task. In this regard, the notion of the generalized inverse of a singular matrix is used for determining response statistics. Further, an application relevant to engineering dynamics problems is included.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khalifah, Peter
2015-02-01
The problem of numerically evaluating absorption correction factors for cylindrical samples has been revisited using a treatment that fully takes advantage of the sample symmetry. It is shown that the path lengths for all points within the sample at all possible diffraction angles can be trivially determined once the angle-dependent distance distribution for a single line of points is calculated. This provides advantages in both computational efficiency and in gaining an intuitive understanding of the effects of absorption on diffraction data. A matrix of absorption coefficients calculated for µR products between 0 and 20 for diffraction angles θD of 0°more » to 90° were used to examine the influence of (1) capillary diameter and of (2) sample density on the overall scattered intensity as a function of diffraction angle, where µ is the linear absorption coefficient for the sample and R is the capillary radius. Based on this analysis, the optimal sample loading for a capillary experiment to maximize diffraction at angles of 0 – 50° is in general expected to be achieved when the maximum radius capillary compatible with the beam is used, and when the sample density is adjusted to be 3/(4µR) of its original density.« less
Khalifah, Peter
2015-02-01
The problem of numerically evaluating absorption correction factors for cylindrical samples has been revisited using a treatment that fully takes advantage of the sample symmetry. It is shown that the path lengths for all points within the sample at all possible diffraction angles can be trivially determined once the angle-dependent distance distribution for a single line of points is calculated. This provides advantages in both computational efficiency and in gaining an intuitive understanding of the effects of absorption on diffraction data. A matrix of absorption coefficients calculated for µR products between 0 and 20 for diffraction angles θ_{D} of 0° to 90° were used to examine the influence of (1) capillary diameter and of (2) sample density on the overall scattered intensity as a function of diffraction angle, where µ is the linear absorption coefficient for the sample and R is the capillary radius. Based on this analysis, the optimal sample loading for a capillary experiment to maximize diffraction at angles of 0 – 50° is in general expected to be achieved when the maximum radius capillary compatible with the beam is used, and when the sample density is adjusted to be 3/(4µR) of its original density.
Hosni, M.H.; Jones, B.W.; Sipes, J.M.; Xu, Y.
1998-10-01
An accurate determination of the cooling load is important in the proper sizing of air-conditioning equipment. Improvements on the thermal insulation characteristics of building materials and recent advances in building envelope systems have reduced the building cooling load from external sources. However, the number of internal cooling load sources have increased due to the addition of various office and laboratory equipment (e.g., microcomputer, monitor, printer copier, scanner, overhead projector, microwave oven, incubator, etc.). In this article, typical office and laboratory equipment such as desktop computers (with a Pentium and a 486DX2-33 processor), monitors, a copier, a laser printer, and a biological incubator are evaluated to determine the total heat gain and the split between radiant and convective heat gain from these items. In addition, two standard objects with well-defined radiant heat loss characteristics, a heated flat slab, and a heated sphere are used to verify the accuracy of measurement and data reduction procedures. The total heat gain from tested office equipment was significantly less than the name plate ratings even when operated continuously. The actual power consumption ranged from 14% to 36% of the name plate ratings. Thus, care must be taken when using equipment nameplate ratings in estimating total heat gain for air-conditioning equipment sizing.
Coupling coefficients for tensor product representations of quantum SU(2)
Groenevelt, Wolter
2014-10-15
We study tensor products of infinite dimensional irreducible {sup *}-representations (not corepresentations) of the SU(2) quantum group. We obtain (generalized) eigenvectors of certain self-adjoint elements using spectral analysis of Jacobi operators associated to well-known q-hypergeometric orthogonal polynomials. We also compute coupling coefficients between different eigenvectors corresponding to the same eigenvalue. Since the continuous spectrum has multiplicity two, the corresponding coupling coefficients can be considered as 2 2-matrix-valued orthogonal functions. We compute explicitly the matrix elements of these functions. The coupling coefficients can be considered as q-analogs of Bessel functions. As a results we obtain several q-integral identities involving q-hypergeometric orthogonal polynomials and q-Bessel-type functions.
Identification of Bayesian posteriors for coefficients of chaos expansions
Arnst, M. Ghanem, R.; Soize, C.
2010-05-01
This article is concerned with the identification of probabilistic characterizations of random variables and fields from experimental data. The data used for the identification consist of measurements of several realizations of the uncertain quantities that must be characterized. The random variables and fields are approximated by a polynomial chaos expansion, and the coefficients of this expansion are viewed as unknown parameters to be identified. It is shown how the Bayesian paradigm can be applied to formulate and solve the inverse problem. The estimated polynomial chaos coefficients are hereby themselves characterized as random variables whose probability density function is the Bayesian posterior. This allows to quantify the impact of missing experimental information on the accuracy of the identified coefficients, as well as on subsequent predictions. An illustration in stochastic aeroelastic stability analysis is provided to demonstrate the proposed methodology.
Lattice-structures and constructs with designed thermal expansion coefficients
Spadaccini, Christopher; Hopkins, Jonathan
2014-10-28
A thermal expansion-managed lattice structure having a plurality of unit cells each having flexure bearing-mounted tabs supported on a base and actuated by thermal expansion of an actuator having a thermal expansion coefficient greater than the base and arranged so that the tab is inwardly displaced into a base cavity. The flexure bearing-mounted tabs are connected to other flexure-bearing-mounted tabs of adjacent unit cells so that the adjacent unit cells are spaced from each other to accommodate thermal expansion of individual unit cells while maintaining a desired bulk thermal expansion coefficient of the lattice structure as a whole.
Sandia Research on Rooftop Structural Strength Gains Attention
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
on Rooftop Structural Strength Gains Attention - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management
High gain preamplifier based on optical parametric amplification
Jovanovic, Igor; Bonner, Randal A.
2004-08-10
A high-gain preamplifier based on optical parametric amplification. A first nonlinear crystal is operatively connected to a second nonlinear crystal. A first beam relay telescope is operatively connected to a second beam relay telescope, to the first nonlinear crystal, and to the second nonlinear crystal. A first harmonic beamsplitter is operatively connected to a second harmonic beamsplitter, to the first nonlinear crystal, to the second nonlinear crystal, to the first beam relay telescope, and to the second beam relay telescope.
Hewlett Packard Labs Gains Insights with Innovative ALS Research Tools
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Hewlett Packard Labs Gains Insights with Innovative ALS Research Tools Print For the past eight years, Hewlett Packard Labs, the central research organization of Hewlett Packard Enterprise (HPE), has been using cutting-edge ALS techniques to advance some of their most promising technological research. Hewlett Packard Labs researchers, including Suhas Kumar, Catherine Graves, and John Paul Strachan, recently made the cover of Applied Physics Letters with an ALS-based project that revealed key
Students gain valuable supercomputing skills while getting paid
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Computer summer institute Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue: September 1, 2016 all issues All Issues » submit Students gain valuable supercomputing skills while getting paid Laboratory summer institute provides unique internship experience September 1, 2015 Laboratory intern Destiny Velasquez. Laboratory intern Destiny Velasquez. Contact Community Programs Director Kathy Keith Email Editor Ute Haker Email Over the past
Wind Gains ground, hitting 33 GW of installed capacity
2010-06-15
The U.S. currently has 33 GW of installed wind capacity. Wind continues to gain ground, accounting for 42 percent of new capacity additions in the US in 2008.Globally, there are now 146 GW of wind capacity with an impressive and sustained growth trajectory that promises to dominate new generation capacities in many developing countries. The U.S., however, lags many European countries, with wind providing roughly 2 percent of electricity generation.
U-142: HP Onboard Administrator Bugs Let Remote Users Gain Access...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
2: HP Onboard Administrator Bugs Let Remote Users Gain Access, Obtain Information, and Conduct URL Redirection Attacks U-142: HP Onboard Administrator Bugs Let Remote Users Gain...
Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients
Dan Wendt; Greg Mines
2011-10-01
Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients Dan Wendt, Greg Mines Idaho National Laboratory The use of mixed working fluids in binary power plants can provide significant increases in plant performance, provided the heat exchangers are designed to take advantage of these fluids non-isothermal phase changes. In the 1980's testing was conducted at DOE's Heat Cycle Research Facility (HCRF) where mixtures of different compositions were vaporized at supercritical pressures and then condensed. This testing had focused on using the data collected to verify that Heat Transfer Research Incorporated (HTRI) codes were suitable for the design of heat exchangers that could be used with mixtures. The HCRF data includes mixture compositions varying from 0% to 40% isopentane and condenser tube orientations of 15{sup o}, 60{sup o}, and 90{sup o} from horizontal. Testing was performed over a range of working fluid and cooling fluid conditions. Though the condenser used in this testing was water cooled, the working fluid condensation occurred on the tube-side of the heat exchanger. This tube-side condensation is analogous to that in an air-cooled condenser. Tube-side condensing heat transfer coefficient information gleaned from the HCRF testing is used in this study to assess the suitability of air-cooled condenser designs for use with mixtures. Results of an air-cooled binary plant process model performed with Aspen Plus indicate that that the optimal mixture composition (producing the maximum net power for the scenario considered) is within the range of compositions for which data exist. The HCRF data is used to assess the impact of composition, tube orientation, and process parameters on the condensing heat transfer coefficients. The sensitivity of the condensing coefficients to these factors is evaluated and the suitability of air-cooled condenser designs with mixtures is assessed. This paper summarizes the evaluation of the HCRF
STARS A Two Stage High Gain Harmonic Generation FEL Demonstrator
M. Abo-Bakr; W. Anders; J. Bahrdt; P. Budz; K.B. Buerkmann-Gehrlein; O. Dressler; H.A. Duerr; V. Duerr; W. Eberhardt; S. Eisebitt; J. Feikes; R. Follath; A. Gaupp; R. Goergen; K. Goldammer; S.C. Hessler; K. Holldack; E. Jaeschke; Thorsten Kamps; S. Klauke; J. Knobloch; O. Kugeler; B.C. Kuske; P. Kuske; A. Meseck; R. Mitzner; R. Mueller; M. Neeb; A. Neumann; K. Ott; D. Pfluckhahn; T. Quast; M. Scheer; Th. Schroeter; M. Schuster; F. Senf; G. Wuestefeld; D. Kramer; Frank Marhauser
2007-08-01
BESSY is proposing a demonstration facility, called STARS, for a two-stage high-gain harmonic generation free electron laser (HGHG FEL). STARS is planned for lasing in the wavelength range 40 to 70 nm, requiring a beam energy of 325 MeV. The facility consists of a normal conducting gun, three superconducting TESLA-type acceleration modules modified for CW operation, a single stage bunch compressor and finally a two-stage HGHG cascaded FEL. This paper describes the faciliy layout and the rationale behind the operation parameters.
Office of Energy Efficiency and Renewable Energy (EERE)
A remote authenticated user with 'Create Table' privileges can gain 'SYS' privileges on the target system.
Sign problem in Z-coefficient for particle emission angular distributi...
Office of Scientific and Technical Information (OSTI)
Sign problem in Z-coefficient for particle emission angular distributions Citation Details In-Document Search Title: Sign problem in Z-coefficient for particle emission angular ...
Sign problem in Z-coefficient for particle emission angular distributi...
Office of Scientific and Technical Information (OSTI)
Sign problem in Z-coefficient for particle emission angular distributions Citation Details In-Document Search Title: Sign problem in Z-coefficient for particle emission angular...
Alternative Fuels Data Center: Little Rock Gains Momentum with Natural Gas
Buses Little Rock Gains Momentum with Natural Gas Buses to someone by E-mail Share Alternative Fuels Data Center: Little Rock Gains Momentum with Natural Gas Buses on Facebook Tweet about Alternative Fuels Data Center: Little Rock Gains Momentum with Natural Gas Buses on Twitter Bookmark Alternative Fuels Data Center: Little Rock Gains Momentum with Natural Gas Buses on Google Bookmark Alternative Fuels Data Center: Little Rock Gains Momentum with Natural Gas Buses on Delicious Rank
Scale dependency of the effective matrix diffusion coefficient
Liu, H.H.; Bodvarsson, G.S.; Zhang, G.
2003-05-30
It has been recognized that matrix diffusion is an important process for retarding solute transport in fractured rock. Based on analyses of tracer transport data from a number of field tests, we demonstrate for the first time that the effective matrix-diffusion coefficient may be scale dependent and generally increases with test scale. A preliminary theoretical explanation of this scale dependency is also presented, based on the hypothesis that solute travel paths within a fracture network are fractals.
Theoretical rate coefficients for allyl + HO2 and allyloxy decomposition
Goldsmith, C. F.; Klippenstein, S. J.; Green, W. H.
2011-01-01
The kinetics of the allyl + HO{sub 2} bimolecular reaction, the thermal decomposition of C{sub 3}H{sub 5}OOH, and the unimolecular reactions of C{sub 3}H{sub 5}O are studied theoretically. High-level ab initio calculations of the C{sub 3}H{sub 5}OOH and C{sub 3}H{sub 5}O potential energy surfaces are coupled with RRKM master equation methods to compute the temperature- and pressure-dependence of the rate coefficients. Variable reaction coordinate transition state theory is used to characterize the barrierless transition states for the allyl + HO{sub 2} and C{sub 3}H{sub 5}O + OH reactions. The predicted rate coefficients for allyl + HO{sub 2} ? C{sub 3}H{sub 5}OOH ? products are in good agreement with experimental values. The calculations for allyl + HO{sub 2} ? C{sub 3}H{sub 6} + O{sub 2} underpredict the observed rate. The new rate coefficients suggest that the reaction of allyl + HO{sub 2} will promote chain-branching significantly more than previous models suggest.
Relative Gain Monitoring of the GlueX Calorimeters
Anassontzis, Efstratios G.; Kourkoumelis, C.; Vasileiadis, G.; Voulgaris, G.; Kappos, E.; Beattie, T.; Krueger, S.; Lolos, G. J.; Papandreou, Z.; Semenov, A. Yu.; Frye, John M.; Leckey, John P.; Shepherd, Matt; Bogart, T.; Smith, Elton S.
2014-02-01
The relative gain of the photodetectors for the GlueX Barrel and Forward calorimeters will be monitored using modular LED driver systems. The BCAL system consists of a global controller that feeds power, bias voltage and trigger signals to 96 local controllers situated at the ends of the 48 BCAL modules, which drive 40 LEDs associated with the 40 light guides at the end of each module. The FCAL system consists also of a global controller, a local controller for each acrylic quadrant covering the face of the FCAL, and ten 4-LED pulser boards per local controller connected in a star configuration along the edges of the acrylic panes. The respective systems are currently being installed on the detectors and their tested performance is presented herein.
Gain and frequency tuning within the mouse cochlear apex
Oghalai, John S.; Raphael, Patrick D.; Gao, Simon; Lee, Hee Yoon; Groves, Andrew K.; Zuo, Jian; Applegate, Brian E.
2015-12-31
Normal mammalian hearing requires cochlear outer hair cell active processes that amplify the traveling wave with high gain and sharp tuning, termed cochlear amplification. We have used optical coherence tomography to study cochlear amplification within the apical turn of the mouse cochlea. We measured not only classical basilar membrane vibratory tuning curves but also vibratory responses from the rest of the tissues that compose the organ of Corti. Basilar membrane tuning was sharp in live mice and broad in dead mice, whereas other regions of the organ of Corti demonstrated phase shifts consistent with additional filtering beyond that provided by basilar membrane mechanics. We use these experimental data to support a conceptual framework of how cochlear amplification is tuned within the mouse cochlear apex. We will also study transgenic mice with targeted mutations that affect different biomechanical aspects of the organ of Corti in an effort to localize the underlying processes that produce this additional filtering.
Progress on achieving the ICF conditions needed for high gain
Lindl, J.D.
1988-12-23
Progress during the past two years has moved us much closer to demonstrating the scientific and technological requirements for high gain ICF in the laboratory. This progress has been made possible by operating at the third harmonic of 1..mu..m light which dramatically reduces concern about hot electrons and by advances in diagnostics such as 100 ps x-ray framing cameras which greatly increase the data available from each experiment. Making use of many of these new capabilities, major improvements in confinement conditions have been achieved for ICF implosions. In particular, in an optimized hohlraum on Nova, radiation driven implosions with convergence ratio in excess of 30 (volume compression /approximately/3 /times/ 10/sup 4/) have performed essentially as predicted by spherical implosion calculations. This paper presents these results as well as examples of advances in several other areas and discusses the implications for the future of ICF with lasers and heavy ion beam drivers. 8 refs., 10 figs.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Chitra Sivaraman; Connor Flynn
2004-10-01
10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Chitra Sivaraman; Connor Flynn
2004-10-01
1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Chitra Sivaraman; Connor Flynn
10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Chitra Sivaraman; Connor Flynn
10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Sivaraman, Chitra; Flynn, Connor
2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Chitra Sivaraman; Connor Flynn
1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Newsom, Rob; Goldsmith, John
1998-03-01
10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Sivaraman, Chitra; Flynn, Connor
2004-10-01
2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
ORISE: Dose Coefficients for Intakes of Radionuclides via Contaminated Wounds
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Dose CoeffiCients for intakes of raDionuCliDes via ContaminateD WounDs R. E. Toohey*, L. Bertelli + , S. L. Sugarman*, A. L. Wiley* and D. M. Christensen* *Radiation Emergency Assistance Center/Training Site, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37031-0117; + Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545. Ver. 2, Aug 2014 The NCRP Wound Model describing the retention of selected radionuclides at the site of a contaminated
Trigonometric Pade approximants for functions with regularly decreasing Fourier coefficients
Labych, Yuliya A; Starovoitov, Alexander P [Gomel State University, Gomel (Belarus)
2009-08-31
Sufficient conditions describing the regular decrease of the coefficients of a Fourier series f(x)=a{sub 0}/2 + {sigma} a{sub n} cos kx are found which ensure that the trigonometric Pade approximants {pi}{sup t}{sub n,m}(x;f) converge to the function f in the uniform norm at a rate which coincides asymptotically with the highest possible one. The results obtained are applied to problems dealing with finding sharp constants for rational approximations. Bibliography: 31 titles.
Electrical and Optical Gain Lever Effects in InGaAs Double Quantum Well Diode Lasers
Pocha, M D; Goddard, L L; Bond, T C; Nikolic, R J; Vernon, S P; Kallman, J S; Behymer, E M
2007-01-03
In multisection laser diodes, the amplitude or frequency modulation (AM or FM) efficiency can be improved using the gain lever effect. To study gain lever, InGaAs double quantum well (DQW) edge emitting lasers have been fabricated with integrated passive waveguides and dual sections providing a range of split ratios from 1:1 to 9:1. Both the electrical and the optical gain lever have been examined. An electrical gain lever with greater than 7 dB enhancement of AM efficiency was achieved within the range of appropriate DC biasing currents, but this gain dropped rapidly outside this range. We observed a 4 dB gain in the optical AM efficiency under non-ideal biasing conditions. This value agreed with the measured gain for the electrical AM efficiency under similar conditions. We also examined the gain lever effect under large signal modulation for digital logic switching applications. To get a useful gain lever for optical gain quenched logic, a long control section is needed to preserve the gain lever strength and a long interaction length between the input optical signal and the lasing field of the diode must be provided. The gain lever parameter space has been fully characterized and validated against numerical simulations of a semi-3D hybrid beam propagation method (BPM) model for the coupled electron-photon rate equation. We find that the optical gain lever can be treated using the electrical injection model, once the absorption in the sample is known.
Klems, J.H.
1993-10-01
A new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorptances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient. A preceding paper outlined the method and provided the physical derivation of the calculation. In this second of a series of related papers the detailed development of the matrix layer calculation is presented.
Mixing coefficients for subchannel analyses with supercritical water
Vogt, Bastian; Laurien, Eckart; Class, Andreas G.; Schulenberg, Thomas
2007-07-01
This paper is related to pressure drop and mixing correlations which are used in subchannel codes. The commercial CFD code STAR-CD has been applied for central subchannels of a supercritical water reactor fuel assembly design. First, pressure drop coefficients for cross flow have been evaluated for this geometry using steady state calculations. Different from established correlations for cross flow in rod bundles, the effects of strong axial flow in the bundle have been taken into account for the presented geometry, flow conditions and fluid properties. In the second part of the paper the unsteady RANS CFD-method is applied and assessed with respect to the prediction of flow pulsation phenomena and turbulent mixing. The results are compared with experimental correlations for the turbulent mixing coefficient and the flow pulsation frequency. It is found that the applied unsteady RANS method is able to predict the flow pulsation frequency but over-predicts the turbulent mixing by a factor of around 3.5. (authors)
Applications of the second virial coefficient: protein crystallization and solubility
Wilson, William W.; DeLucas, Lawrence J.
2014-04-30
This article highlights some of the ground-based studies emanating from NASAs Microgravity Protein Crystal Growth (PCG) program, and includes a more detailed discussion of the history and the progress made in one of the NASA-funded PCG investigations involving the use of measured second virial coefficients (B values) as a diagnostic indicator of solution conditions conducive to protein crystallization. This article begins by highlighting some of the ground-based studies emanating from NASAs Microgravity Protein Crystal Growth (PCG) program. This is followed by a more detailed discussion of the history of and the progress made in one of the NASA-funded PCG investigations involving the use of measured second virial coefficients (B values) as a diagnostic indicator of solution conditions conducive to protein crystallization. A second application of measured B values involves the determination of solution conditions that improve or maximize the solubility of aqueous and membrane proteins. These two important applications have led to several technological improvements that simplify the experimental expertise required, enable the measurement of membrane proteins and improve the diagnostic capability and measurement throughput.
9 GeV energy gain in a beam-driven plasma wakefield accelerator...
Office of Scientific and Technical Information (OSTI)
9 GeV energy gain in a beam-driven plasma wakefield accelerator Citation Details In-Document Search Title: 9 GeV energy gain in a beam-driven plasma wakefield accelerator An ...
Winning the Future: Tonto Apache Tribe Uses DOE Funding to Gain...
Winning the Future: Tonto Apache Tribe Uses DOE Funding to Gain Momentum on Solar Energy Development Winning the Future: Tonto Apache Tribe Uses DOE Funding to Gain Momentum on ...
U-056: Linux Kernel HFS Buffer Overflow Lets Local Users Gain...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
6: Linux Kernel HFS Buffer Overflow Lets Local Users Gain Root Privileges U-056: Linux Kernel HFS Buffer Overflow Lets Local Users Gain Root Privileges December 9, 2011 - 8:00am...
V-115: Apple iOS Bugs Let Local Users Gain Elevated Privileges...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
5: Apple iOS Bugs Let Local Users Gain Elevated Privileges V-115: Apple iOS Bugs Let Local Users Gain Elevated Privileges March 20, 2013 - 12:08am Addthis PROBLEM: Apple iOS Bugs...
EM Employee to Gain Expertise in Japan Through Unique One-Year...
Employee to Gain Expertise in Japan Through Unique One-Year Fellowship EM Employee to Gain Expertise in Japan Through Unique One-Year Fellowship March 31, 2014 - 12:00pm Addthis ...
Rajan, M. S. Mani; Mahalingam, A.
2013-04-15
In this paper, we introduce a system of the nonlinear Schroedinger-Maxwell-Bloch equation with variable coefficients which represents the propagation of optical pulses in an inhomogeneous erbium doped fiber with loss/gain driven by an external potential. The one and two soliton solutions in explicit forms are generated by using the Darboux transformation and the associated Lax pair. We consider the distributed amplification system, and some main features of the solutions are demonstrated graphically. We also consider the concept of soliton propagation in a dispersion managed erbium doped fiber and through symbolic computation, we have carried out our study from an analytic viewpoint.
Kumar, Hitender; Malik, Anand; Chand, Fakir
2012-10-15
We obtain exact spatiotemporal periodic traveling wave solutions to the generalized (3+1)-dimensional cubic-quintic nonlinear Schroedinger equation with spatial distributed coefficients. For restrictive parameters, these periodic wave solutions acquire the form of localized spatial solitons. Such solutions exist under certain conditions, and impose constraints on the functions describing dispersion, nonlinearity, and gain (or loss). We then demonstrate the nonlinear tunneling effects and controllable compression technique of three-dimensional bright and dark solitons when they pass unchanged through the potential barriers and wells affected by special choices of the diffraction and/or the nonlinearity parameters. Direct numerical simulation has been performed to show the stable propagation of bright soliton with 5% white noise perturbation.
GAiN: Distributed Array Computation with Python
Daily, Jeffrey A.
2009-04-24
Scientific computing makes use of very large, multidimensional numerical arrays - typically, gigabytes to terabytes in size - much larger than can fit on even the largest single compute node. Such arrays must be distributed across a "cluster" of nodes. Global Arrays is a cluster-based software system from Battelle Pacific Northwest National Laboratory that enables an efficient, portable, and parallel shared-memory programming interface to manipulate these arrays. Written in and for the C and FORTRAN programming languages, it takes advantage of high-performance cluster interconnections to allow any node in the cluster to access data on any other node very rapidly. The "numpy" module is the de facto standard for numerical calculation in the Python programming language, a language whose use is growing rapidly in the scientific and engineering communities. numpy provides a powerful N-dimensional array class as well as other scientific computing capabilities. However, like the majority of the core Python modules, numpy is inherently serial. Our system, GAiN (Global Arrays in NumPy), is a parallel extension to Python that accesses Global Arrays through numpy. This allows parallel processing and/or larger problem sizes to be harnessed almost transparently within new or existing numpy programs.
Tang, Linlong; Du, Jinglei; Shi, Haofei Wei, Dongshan; Du, Chunlei
2014-10-15
We exploit inter-layer radiative transitions to provide gains to amplify terahertz waves in graphene heterostructures. This is achieved by properly doping graphene sheets and aligning their energy bands so that the processes of stimulated emissions can overwhelm absorptions. We derive an expression for the gain estimation and show the gain is insensitive to temperature variation. Moreover, the gain is broadband and can be strong enough to compensate the free carrier loss, indicating graphene based room temperature terahertz lasers are feasible.
Red, green, and blue lasing enabled by single-exciton gain in colloidal quantum dot films
Nurmikko, Arto V.; Dang, Cuong
2016-06-21
The methods and materials described herein contemplate the use films of colloidal quantum dots as a gain medium in a vertical-cavity surface-emitting laser. The present disclosure demonstrates a laser with single-exciton gain in the red, green, and blue wavelengths. Leveraging this nanocomposite gain, the results realize a significant step toward full-color single-material lasers.
Fuel temperature reactivity coefficient calculation by Monte Carlo perturbation techniques
Shim, H. J.; Kim, C. H.
2013-07-01
We present an efficient method to estimate the fuel temperature reactivity coefficient (FTC) by the Monte Carlo adjoint-weighted correlated sampling method. In this method, a fuel temperature change is regarded as variations of the microscopic cross sections and the temperature in the free gas model which is adopted to correct the asymptotic double differential scattering kernel. The effectiveness of the new method is examined through the continuous energy MC neutronics calculations for PWR pin cell problems. The isotope-wise and reaction-type-wise contributions to the FTCs are investigated for two free gas models - the constant scattering cross section model and the exact model. It is shown that the proposed method can efficiently predict the reactivity change due to the fuel temperature variation. (authors)
Calculation of combined diffusion coefficients in SF{sub 6}-Cu mixtures
Zhong, Linlin; Wang, Xiaohua Rong, Mingzhe Wu, Yi; Murphy, Anthony B.
2014-10-15
Diffusion coefficients play an important role in the description of the transport of metal vapours in gas mixtures. This paper is devoted to the calculation of four combined diffusion coefficients, namely, the combined ordinary diffusion coefficient, combined electric field diffusion coefficient, combined temperature diffusion coefficient, and combined pressure diffusion coefficient in SF{sub 6}-Cu mixtures at temperatures up to 30 000 K. These four coefficients describe diffusion due to composition gradients, applied electric fields, temperature gradients, and pressure gradients, respectively. The influence of copper fluoride and sulfide species on the diffusion coefficients is shown to be negligible. The effect of copper proportion and gas pressures on these diffusion coefficients is investigated. It is shown that increasing the proportion of copper generally increases the magnitude of the four diffusion coefficients, except for copper mole fractions of 90% or more. It is further found that increasing the pressure reduces the magnitude of the coefficients, except for the combined temperature diffusion coefficient, and shifts the maximum of all four coefficients towards higher temperatures. The results presented in this paper can be applied to the simulation of high-voltage circuit breaker arcs.
Enhancing optical gains in Si nanocrystals via hydrogenation and cerium ion doping
Wang, Dong-Chen; Li, Yan-Li; Song, Sheng-Chi; Guo, Wen-Ping; Lu, Ming; Chen, Jia-Rong
2014-07-28
We report optical gain enhancements in Si nanocrystals (Si-NCs) via hydrogenation and Ce{sup 3+} ion doping. Variable stripe length technique was used to obtain gains. At 0.3 W/cm{sup 2} pumping power density of pulsed laser, net gains were observed together with gain enhancements after hydrogenation and/or Ce{sup 3+} ion doping; gains after loss corrections were between 89.52 and 341.95 cm{sup −1}; and the photoluminescence (PL) lifetime was found to decrease with the increasing gain enhancement. At 0.04 W/cm{sup 2} power density, however, no net gain was found and the PL lifetime increased with the increasing PL enhancement. The results were discussed according to stimulated and spontaneous excitation and de-excitation mechanisms of Si-NCs.
Power coefficient of tornado-type wind turbines
Rangwalla, A.A.; Hsu, C.T.
1983-11-01
In a tornado-type wind turbine the wind collecting tower is equipped with adjustable vanes that can be opened on the windward side and closed on the leeward side. The wind enters the tower tangentially through these open vanes and exits from the top. As a result, a vortex is formed inside the tower. A vertical axis turbine which is located underneath the tower floor admits air vertically and exhausts it into the vortex core. The pressure drop in the vortex core can be high, depending upon the vortex concentration, thus enhancing manyfold the total pressure drop across the turbine. The power coefficient C /SUB p/ of this system depends mainly on how low a pressure can be created in the vortex core. A maximum C /SUB p/ of about 2.5 was obtained by Yen for a spiral shaped tower. This is about 6.25 times the C /SUB p/ of conventional windmills. Analytical studies have been carried out by several investigators to study the C /SUB p/ of this vortex machine. Loth considered the conservation of angular momentum and obtained a C /SUB p/ based on the tower frontal area, which is not impressive.
Determination of the Evaporation Coefficient of D2O
Drisdell, Walter S.; Cappa, Christopher D.; Smith, Jared D.; Saykally, Richard J.; Cohen, Ronald C.
2008-03-26
The evaporation rate of D{sub 2}O has been determined by Raman thermometry of a droplet train (12-15 {micro}m diameter) injected into vacuum ({approx}10{sup -5} torr). The cooling rate measured as a function of time in vacuum was fit to a model that accounts for temperature gradients between the surface and the core of the droplets, yielding an evaporation coefficient ({gamma}{sub e}) of 0.57 {+-} 0.06. This is nearly identical to that found for H{sub 2}O (0.62 {+-} 0.09) using the same experimental method and model, and indicates the existence of a kinetic barrier to evaporation. The application of a recently developed transition state theory (TST) model suggests that the kinetic barrier is due to librational and hindered translational motions at the liquid surface, and that the lack of an isotope effect is due to competing energetic and entropic factors. The implications of these results for cloud and aerosol particles in the atmosphere are discussed.
Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing
Thomas, Stanley W.
1995-01-01
The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible.
Image intensifier gain uniformity improvements in sealed tubes by selective scrubbing
Thomas, S.W.
1995-04-18
The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible. 4 figs.
Wang, H.-L.; Liu, B.
2014-03-21
This paper investigates what is the largest magnetoelectric (ME) coefficient of ME composites, and how to realize it. From the standpoint of energy conservation, a theoretical analysis is carried out on an imaginary lever structure consisting of a magnetostrictive phase, a piezoelectric phase, and a rigid lever. This structure is a generalization of various composite layouts for optimization on ME effect. The predicted theoretical ultimate ME coefficient plays a similar role as the efficiency of ideal heat engine in thermodynamics, and is used to evaluate the existing typical ME layouts, such as the parallel sandwiched layout and the serial layout. These two typical layouts exhibit ME coefficient much lower than the theoretical largest values, because in the general analysis the stress amplification ratio and the volume ratio can be optimized independently and freely, but in typical layouts they are dependent or fixed. To overcome this shortcoming and achieve the theoretical largest ME coefficient, a new design is presented. In addition, it is found that the most commonly used electric field ME coefficient can be designed to be infinitely large. We doubt the validity of this coefficient as a reasonable ME effect index and consider three more ME coefficients, namely the electric charge ME coefficient, the voltage ME coefficient, and the static electric energy ME coefficient. We note that the theoretical ultimate value of the static electric energy ME coefficient is finite and might be a more proper measure of ME effect.
The Next Generation Nuclear Plant - Insights Gained from the INEEL Point Design Studies
Philip E. MacDonald; A. M. Baxter; P. D. Bayless; J. M. Bolin; H. D. Gougar; R. L. Moore; A. M. Ougouag; M. B. Richards; R. L. Sant; J. W. Sterbentz; W. K. Terry
2004-08-01
This paper provides the results of an assessment of two possible versions of the Next Generation Nuclear Plant (NGNP), a prismatic fuel type helium gas-cooled reactor and a pebble-bed fuel helium gas reactor. Insights gained regarding the strengths and weaknesses of the two designs are also discussed. Both designs will meet the three basic requirements that have been set for the NGNP: a coolant outlet temperature of 1000 C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors. Two major modifications of the current Gas Turbine- Modular Helium Reactor (GT-MHR) design were needed to obtain a prismatic block design with a 1000 C outlet temperature: reducing the bypass flow and better controlling the inlet coolant flow distribution to the core. The total power that could be obtained for different core heights without exceeding a peak transient fuel temperature of 1600 C during a high or low-pressure conduction cooldown event was calculated. With a coolant inlet temperature of 490 C and 10% nominal core bypass flow, it is estimated that the peak power for a 10-block high core is 686 MWt, for a 12-block high core is 786 MWt, and for a 14-block core is about 889 MWt. The core neutronics calculations showed that the NGNP will exhibit strongly negative Doppler and isothermal temperature coefficients of reactivity over the burnup cycle. In the event of rapid loss of the helium gas, there is negligible core reactivity change. However, water or steam ingress into the core coolant channels can produce a relatively large reactivity effect. Two versions of an annular pebble-bed NGNP have also been developed, a 300 and a 600 MWt module. From this work we learned how to design passively safe pebble bed reactors that produce more than 600 MWt. We also found a way to improve both the fuel utilization and safety by modifying the pebble design (by adjusting the fuel zone radius in the pebble to optimize the fuel
Wang, Jinyang; Zhong, Haimin; Qiu, Wenda; Chen, Liuping; Feng, Huajie
2014-03-14
The binary infinite dilute diffusion coefficients, D{sub 12}{sup ?}, of some alkylbenzenes (Ph-C{sub n}, from Ph-H to Ph-C{sub 12}) from 313 K to 333 K at 15 MPa in supercritical carbon dioxide (scCO{sub 2}) have been studied by molecular dynamics (MD) simulation. The MD values agree well with the experimental ones, which indicate MD simulation technique is a powerful way to predict and obtain diffusion coefficients of solutes in supercritical fluids. Besides, the local structures of Ph-C{sub n}/CO{sub 2} fluids are further investigated by calculating radial distribution functions and coordination numbers. It qualitatively convinces that the first solvation shell of Ph-C{sub n} in scCO{sub 2} is significantly influenced by the structure of Ph-C{sub n} solute. Meanwhile, the mean end-to-end distance, the mean radius of gyration and dihedral angle distribution are calculated to gain an insight into the structural properties of Ph-C{sub n} in scCO{sub 2}. The abnormal trends of radial distribution functions and coordination numbers can be reasonably explained in term of molecular flexibility. Moreover, the computed results of dihedral angle clarify that flexibility of long-chain Ph-C{sub n} is the result of internal rotation of C-C single bond (?{sub c-c}) in alkyl chain. It is interesting that compared with n-alkane, because of the existence of benzene ring, the flexibility of alkyl chain in Ph-C{sub n} with same carbon atom number is significantly reduced, as a result, the carbon chain dependence of diffusion behaviors for long-chain n-alkane (n ? 5) and long-chain Ph-C{sub n} (n ? 4) in scCO{sub 2} are different.
DOE Challenge Home Gaining Recognition as a Leader Webinar (Text Version) |
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Department of Energy Challenge Home Gaining Recognition as a Leader Webinar (Text Version) DOE Challenge Home Gaining Recognition as a Leader Webinar (Text Version) Below is a text version of the webinar titled "Gaining Recognition as a Leader," originally presented in May 2013. In addition to this text version of the audio, you can access a recording of the webinar. Sam Rashkin: Slide 1: This is about the DOE Challenge Home as a way for builders to be recognized a leader.
Bahlali, Khaled Djehiche, Boualem Mezerdi, Brahim
2007-12-15
We establish a stochastic maximum principle in optimal control of a general class of degenerate diffusion processes with global Lipschitz coefficients, generalizing the existing results on stochastic control of diffusion processes. We use distributional derivatives of the coefficients and the Bouleau Hirsh flow property, in order to define the adjoint process on an extension of the initial probability space.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Sivaraman, Chitra; Flynn, Connor
10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Sivaraman, Chitra; Flynn, Connor
2010-12-15
10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm
Burr, M.T.
1995-10-01
Few regions of the world exemplify the variety of approaches to power sector reform as thoroughly as Latin America. At one end of the spectrum stands Chile, which has successfully restructured its electric power industry, privatizing a large share of its formerly state-owned utility assets. Of all power markets in Latin America, Chile`s is the most open to private developers, with transparent pricing policies and competitive procurement procedures. At the other end of the spectrum, Venezuela`s privatization program has stalled, and the power market has become less accessible to private investment than before the current administration was elected. Many Latin American countries share some important challenges. First, a lack of credit worthiness among electric utilities makes it difficult to finance power projects that rely on long-term power sales agreements. Second, lingering fallout from Mexico`s financial crisis continues to affect commercial lenders` confidence in Latin America in general. Third, efforts at privatization and power market liberalization have proceeded in fits and starts, with some countries seeming to take as many steps backwards as forward. Nevertheless, Latin America remains one of the most attractive regions of the world for independent power development. This paper examines recent developments in key markets.
U-068:Linux Kernel SG_IO ioctl Bug Lets Local Users Gain Elevated...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Linux Kernel SGIO ioctl Bug Lets Local Users Gain Elevated Privileges PLATFORM: Red Hat Enterprise Linux Desktop (v. 6) Red Hat Enterprise Linux HPC Node (v. 6) Red Hat...
T-563: Red Hat Directory Server Bugs Let Local Users Gain Elevated...
Broader source: Energy.gov (indexed) [DOE]
server and command line utilities for server administration. Addthis Related Articles T-671: Red Hat system-config-firewall Lets Local Users Gain Root Privileges V-041: Red Hat...
DOE Program Offers Participants Unique Opportunity to Gain Carbon Capture and Storage Knowledge
Broader source: Energy.gov [DOE]
Future leaders and innovators in the area of carbon capture and storage can gain a unique and intensive tutorial on the subject by participating in the U.S. Department of Energy’s Research Experience in Carbon Sequestration program.
High-gain direct-drive target design for laser fusion
Bodner, S. E.; Colombant, D. G.; Schmitt, A. J.; Klapisch, M.
2000-06-01
A new laser fusion target concept is presented with a predicted energy gain of 127 using a 1.3 MJ KrF laser. This energy gain is sufficiently high for an economically attractive fusion reactor. X rays from high- and low-Z materials are used in combination with a low-opacity ablator to spatially tune the isentrope, thereby providing both high fuel compression and a reduction of the ablative Rayleigh-Taylor instability. (c) 2000 American Institute of Physics.
New Projects Set to Target Efficiency, Environmental Gains at Advanced Coal
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Gasification Facilities | Department of Energy Projects Set to Target Efficiency, Environmental Gains at Advanced Coal Gasification Facilities New Projects Set to Target Efficiency, Environmental Gains at Advanced Coal Gasification Facilities July 27, 2010 - 1:00pm Addthis Washington, D.C. -- Four projects that will demonstrate an innovative technology that could eventually enhance hydrogen fuel production, lower greenhouse gas (GHG) emissions, improve efficiencies and lower consumer
Road to Fuel Savings: Clean Diesel Trucks Gain Momentum with Nissan and
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Cummins Collaboration | Department of Energy Road to Fuel Savings: Clean Diesel Trucks Gain Momentum with Nissan and Cummins Collaboration Road to Fuel Savings: Clean Diesel Trucks Gain Momentum with Nissan and Cummins Collaboration August 28, 2014 - 9:51am Addthis Pictured here is a clean diesel engine for light trucks that was part of Cummins research and development effort from 1997-2004. Supported with funding by the Energy Department, this engine is as clean and quiet as a gasoline
Potential of Thermoelectrics forOccupant Comfort and Fuel Efficiency Gains
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
in Vehicle Applications | Department of Energy of Thermoelectrics forOccupant Comfort and Fuel Efficiency Gains in Vehicle Applications Potential of Thermoelectrics forOccupant Comfort and Fuel Efficiency Gains in Vehicle Applications Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs. 2006_deer_bell.pdf (1.19 MB) More Documents & Publications Vehicle Fuel Economy
Lipton, Robert Polizzi, Anthony
2014-10-14
We employ metamaterial beam-wave interaction structures for tuning the gain and bandwidth of short traveling wave tubes. The interaction structures are made from metal rings of uniform cross section, which are periodically deployed along the length of the traveling wave tube. The aspect ratio of the ring cross sections is adjusted to control both gain and bandwidth. The frequency of operation is controlled by the filling fraction of the ring cross section with respect to the size of the period cell.
Gain media edge treatment to suppress amplified spontaneous emission in a high power laser
Hackel, Lloyd A.; Soules, Thomas F.; Fochs, Scott N.; Rotter, Mark D.; Letts, Stephan A.
2008-12-09
A novel method and apparatus for suppressing ASE and parasitic oscillation modes in a high average power laser is introduced. By roughening one or more peripheral edges of a solid-state crystal or ceramic laser gain media and by bonding such edges using a substantially high index bonding elastomer or epoxy to a predetermined electromagnetic absorbing arranged adjacent to the entire outer surface of the peripheral edges of the roughened laser gain media, ASE and parasitic oscillation modes can be effectively suppressed.
Gain media edge treatment to suppress amplified spontaneous emission in a high power laser
Hackel, Lloyd A.; Soules, Thomas F.; Fochs, Scott N.; Rotter, Mark D.; Letts, Stephan A.
2011-02-22
A novel method and apparatus for suppressing ASE and/or parasitic oscillation modes in a laser is introduced. By roughening one or more peripheral edges of a solid-state crystal or ceramic laser gain media and by bonding such edges to a predetermined electromagnetic absorbing material arranged adjacent to the entire outer surface of the peripheral edges of the roughened laser gain media, ASE, parasitic oscillation modes and/or residual pump energy can be effectively suppressed.
Klems, J.H.
1993-10-01
A new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorptances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient. In this first in a series of related papers describing the project, the assumptions and limitations of the calculation method are described and the derivation of the matrix calculation technique from the initial integral equations is presented.
Transport coefficients in Lorentz plasmas with the power-law kappa-distribution
Jiulin, Du
2013-09-15
Transport coefficients in Lorentz plasma with the power-law κ-distribution are studied by means of using the transport equation and macroscopic laws of Lorentz plasma without magnetic field. Expressions of electric conductivity, thermoelectric coefficient, and thermal conductivity for the power-law κ-distribution are accurately derived. It is shown that these transport coefficients are significantly modified by the κ-parameter, and in the limit of the parameter κ→∞ they are reduced to the standard forms for a Maxwellian distribution.
HTO washout model: on the relationship between exchange rate and washout coefficient
Golubev, A.; Balashov, Y.; Mavrin, S.; Golubeva, V.; Galeriu, D.
2015-03-15
Washout coefficient Λ is widely used as a parameter in washout models. These models describes overall HTO washout with rain by a first-order kinetic equation, while washout coefficient Λ depends on the type of rain event and rain intensity and empirical parameters a, b. The washout coefficient is a macroscopic parameter and we have considered in this paper its relationship with a microscopic rate K of HTO isotopic exchange in atmospheric humidity and drops of rainwater. We have shown that the empirical parameters a, b can be represented through the rain event characteristics using the relationships of molecular impact rate, rain intensity and specific rain water content while washout coefficient Λ can be represented through the exchange rate K, rain intensity, raindrop diameter and terminal raindrop velocity.
Hardy-Littlewood theorem for trigonometric series with {alpha}-monotone coefficients
Dyachenko, Mikhail I; Nursultanov, Erlan D
2009-12-31
The Hardy-Littlewood theorem is established for trigonometric series with {alpha}-monotone coefficients. Inequalities of Hardy-Littlewood kind are proved. Examples of series demonstrating that the results obtained are sharp are constructed. Bibliography: 15 titles.
FITTING OF THE DATA FOR DIFFUSION COEFFICIENTS IN UNSATURATED POROUS MEDIA
B. Bullard
1999-05-01
The purpose of this calculation is to evaluate diffusion coefficients in unsaturated porous media for use in the TSPA-VA analyses. Using experimental data, regression techniques were used to curve fit the diffusion coefficient in unsaturated porous media as a function of volumetric water content. This calculation substantiates the model fit used in Total System Performance Assessment-1995 An Evaluation of the Potential Yucca Mountain Repository (TSPA-1995), Section 6.5.4.
Coefficient indicates if rod pump can unload water from gas well
Hu Yongquan; Wu Zhijun
1995-09-11
A sucker rod pump can efficiently dewater gas wells if the separation coefficient is sufficiently high. To determine this separation coefficient, it is not sufficient to only know if the system meets the criteria of rod string stress, horsehead load, and crankshaft torque. This paper reviews water production and gas locking problems at the Sichuan gas field and identifies the methodologies used to optimize the pumping efficiency of the area wells.
Microsoft PowerPoint - User Experience with Module Performance Coefficients.pptx
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
borregosolar.com © Borrego Solar Systems, Inc. Private & Confidential Generating Change Since 1980 User Experience with Module Performance Coefficients Bradley Hibberd 2013 Sandia PV Performance Modeling Workshop Santa Clara, CA May 1-2 2013 Published by Sandia National Laboratories with the Permission of the Author www.borregosolar.com © Borrego Solar Systems, Inc. Private & Confidential User Experience with Module Performance Coefficients ‣ Performance Modeling for Projects * For
Microscopic model for intersubband gain from electrically pumped quantum-dot structures
Michael, Stephan; Chow, Weng Wah; Schneider, Han Christian
2014-10-03
We study theoretically the performance of electrically pumped self-organized quantum dots as a gain material in the mid-infrared range at room temperature. We analyze an AlGaAs/InGaAs based structure composed of dots-in-a-well sandwiched between two quantum wells. We numerically analyze a comprehensive model by combining a many-particle approach for electronic dynamics with a realistic modeling of the electronic states in the whole structure. We investigate the gain both for quasi-equilibrium conditions and current injection. We find, comparing different structures, that steady-state gain can only be realized by an efficient extraction process, which prevents an accumulation of electrons in continuum states, that make the available scattering pathways through the quantum-dot active region too fast to sustain inversion.
Microscopic model for intersubband gain from electrically pumped quantum-dot structures
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Michael, Stephan; Chow, Weng Wah; Schneider, Han Christian
2014-10-03
We study theoretically the performance of electrically pumped self-organized quantum dots as a gain material in the mid-infrared range at room temperature. We analyze an AlGaAs/InGaAs based structure composed of dots-in-a-well sandwiched between two quantum wells. We numerically analyze a comprehensive model by combining a many-particle approach for electronic dynamics with a realistic modeling of the electronic states in the whole structure. We investigate the gain both for quasi-equilibrium conditions and current injection. We find, comparing different structures, that steady-state gain can only be realized by an efficient extraction process, which prevents an accumulation of electrons in continuum states, thatmore » make the available scattering pathways through the quantum-dot active region too fast to sustain inversion.« less
Sharma, Rohit; Singh, Kuldip
2014-03-15
In the present work, two cases of thermal plasma have been considered; the ground state plasma in which all the atoms and ions are assumed to be in the ground state and the excited state plasma in which atoms and ions are distributed over various possible excited states. The variation of Z?, frozen isentropic coefficient and the isentropic coefficient with degree of ionization and non-equilibrium parameter ?(= T{sub e}/T{sub h}) has been investigated for the ground and excited state helium and argon plasmas at pressures 1?atm, 10?atm, and 100?atm in the temperature range from 6000?K to 60?000?K. For a given value of non-equilibrium parameter, the relationship of Z? with degree of ionization does not show any dependence on electronically excited states in helium plasma whereas in case of argon plasma this dependence is not appreciable till degree of ionization approaches 2. The minima of frozen isentropic coefficient shifts toward lower temperature with increase of non-equilibrium parameter for both the helium and argon plasmas. The lowering of non-equilibrium parameter decreases the frozen isentropic coefficient more emphatically in helium plasma at high pressures in comparison to argon plasma. The increase of pressure slightly reduces the ionization range over which isentropic coefficient almost remains constant and it does not affect appreciably the dependence of isentropic coefficient on non-equilibrium parameter.
Fuel Cycle Analysis Framework Base Cases for the IAEA/INPRO GAINS Collaborative Project
Brent Dixon
2012-09-01
Thirteen countries participated in the Collaborative Project GAINS Global Architecture of Innovative Nuclear Energy Systems Based on Thermal and Fast Reactors Including a Closed Fuel Cycle, which was the primary activity within the IAEA/INPRO Program Area B: Global Vision on Sustainable Nuclear Energy for the last three years. The overall objective of GAINS was to develop a standard framework for assessing future nuclear energy systems taking into account sustainable development, and to validate results through sample analyses. This paper details the eight scenarios that constitute the GAINS framework base cases for analysis of the transition to future innovative nuclear energy systems. The framework base cases provide a reference for users of the framework to start from in developing and assessing their own alternate systems. Each base case is described along with performance results against the GAINS sustainability evaluation metrics. The eight cases include four using a moderate growth projection and four using a high growth projection for global nuclear electricity generation through 2100. The cases are divided into two sets, addressing homogeneous and heterogeneous scenarios developed by GAINS to model global fuel cycle strategies. The heterogeneous world scenario considers three separate nuclear groups based on their fuel cycle strategies, with non-synergistic and synergistic cases. The framework base case analyses results show the impact of these different fuel cycle strategies while providing references for future users of the GAINS framework. A large number of scenario alterations are possible and can be used to assess different strategies, different technologies, and different assumptions about possible futures of nuclear power. Results can be compared to the framework base cases to assess where these alternate cases perform differently versus the sustainability indicators.
Fact #653: December 13, 2010 Import Cars and Trucks Gaining Ground |
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Department of Energy 3: December 13, 2010 Import Cars and Trucks Gaining Ground Fact #653: December 13, 2010 Import Cars and Trucks Gaining Ground The market share for import cars and light trucks has been growing nearly every year since the mid-1990's. Import car market share more than doubled in that time -- from 14.9% in 1996 to 33.7% in 2009. Imports cars have a larger share of the market than import trucks, but import truck market share has nearly tripled since the mid-1990's. Import
RePower Kitsap Helps S.T.A.R. Program Gain Momentum in Washington |
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Department of Energy Kitsap Helps S.T.A.R. Program Gain Momentum in Washington RePower Kitsap Helps S.T.A.R. Program Gain Momentum in Washington The logo for RePower Kitsap. REALTORS® in western Washington have been lining up to attend the Sustainability Training for Accredited Real Estate Professionals (S.T.A.R.) offered in Kitsap County by Earth Advantage in through RePower Kitsap. The free, accredited S.T.A.R. course-sponsored in partnership with the RePower program, U.S. Department of
Comaskey, Brian J.; Ault, Earl R.; Kuklo, Thomas C.
2005-07-05
A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.
Long wavelength, high gain InAsSb strained-layer superlattice photoconductive detectors
Biefeld, Robert M.; Dawson, L. Ralph; Fritz, Ian J.; Kurtz, Steven R.; Zipperian, Thomas E.
1991-01-01
A high gain photoconductive device for 8 to 12 .mu.m wavelength radiation including an active semiconductor region extending from a substrate to an exposed face, the region comprising a strained-layer superlattice of alternating layers of two different InAs.sub.1-x Sb.sub.x compounds having x>0.75. A pair of spaced electrodes are provided on the exposed face, and changes in 8 to 12 .mu.m radiation on the exposed face cause a large photoconductive gain between the spaced electrodes.
High energy gain in three-dimensional simulations of light sail acceleration
Sgattoni, A.; Sinigardi, S.; Macchi, A.
2014-08-25
The dynamics of radiation pressure acceleration in the relativistic light sail regime are analysed by means of large scale, three-dimensional (3D) particle-in-cell simulations. Differently to other mechanisms, the 3D dynamics leads to faster and higher energy gain than in 1D or 2D geometry. This effect is caused by the local decrease of the target density due to transverse expansion leading to a “lighter sail.” However, the rarefaction of the target leads to an earlier transition to transparency limiting the energy gain. A transverse instability leads to a structured and inhomogeneous ion distribution.
Behavior of the particle transport coefficients near the density limit in MTX
Marinak, M.M.
1993-04-01
The perturbed particle transport coefficients were determined for a range of plasma conditions in the Alcator C tokamak, a component of the Microwave Tokamak Experiment (MTX), from analysis of density perturbations created in gas modulation experiments. Density measurements from a 15 chord far-infrared interferometer were sufficiently detailed to allow radial profiles of the transport coefficients to be resolved. Gas modulation experiments were carried out on plasmas over a range of relatively low currents and a wide variety of line-averaged densities, including values near the Greenwald density limit. With this technique the perturbed diffusion coefficient D and the perturbed convection velocity V can be determined simultaneously. Measured profiles of D rise toward the outside of the plasma column in a manner generally similar to those determined previously for {chi}{sub e,HP} from sawtooth heat pulse propagation. Values of D are typically smaller than those of {chi}{sub e,HP} given for the same line-averaged densities by a factor of 2-5. Diffusion coefficients from a series of discharges at constant current showed little variation with density through most of the saturated ohmic confinement regime. At the Greenwald density limit threshold a dramatic increase occurred in both the perturbed convective and diffusive transport coefficients in the outer region of the plasma. The increases were most pronounced at the outermost range of the radii where coefficients were determined (r/a = 0.8), but were apparent over a region which extended well into the plasma interior. Density profiles maintained a similar shape near the density limit, congruous with the similar behavior of the transport coefficients. No dramatic deterioration was evident in the global energy confinement.
Delivering pump light to a laser gain element while maintaining access to the laser beam
Beach, Raymond J.; Honea, Eric C.; Payne, Stephen A.
2001-01-01
A lens duct is used for pump delivery and the laser beam is accessed through an additional component called the intermediate beam extractor which can be implemented as part of the gain element, part of the lens duct or a separate component entirely.
Dynamic measurement of heat loss coefficients through Trombe wall glazing systems
Balcomb, J.D.
1981-01-01
A Trombe wall presents a unique opportunity to measure the heat-loss coefficient through the glazing system because the wall itself can be used as a heat meter. Since the instantaneous heat flux through the outer wall surface can be determined, the heat loss coefficient at night can be calculated by dividing by the wall surface-to-ambient temperature difference. This technique has been used to determine heat-loss coefficients for Los Alamos test rooms during the winter of 1980-1981. Glazing systems studied include single and double glazing both with and without night insulation used in conjunction with a flat black paint, and both single and double glazing used in conjunction with a selective surface.
Mean ionic activity coefficients in aqueous NaCl solutions from molecular dynamics simulations
Mester, Zoltan; Panagiotopoulos, Athanassios Z.
2015-01-28
The mean ionic activity coefficients of aqueous NaCl solutions of varying concentrations at 298.15 K and 1 bar have been obtained from molecular dynamics simulations by gradually turning on the interactions of an ion pair inserted into the solution. Several common non-polarizable water and ion models have been used in the simulations. Gibbs-Duhem equation calculations of the thermodynamic activity of water are used to confirm the thermodynamic consistency of the mean ionic activity coefficients. While the majority of model combinations predict the correct trends in mean ionic activity coefficients, they overestimate their values at high salt concentrations. The solubility predictions also suffer from inaccuracies, with all models underpredicting the experimental values, some by large factors. These results point to the need for further ion and water model development.
Observed drag coefficients in high winds in the near offshore of the South China Sea
Bi, Xueyan; Liu, Yangan; Gao, Zhiqiu; Liu, Feng; Song, Qingtao; Huang, Jian; Huang, Huijun; Mao, Weikang; Liu, Chunxia
2015-07-14
This paper investigates the relationships between friction velocity, 10 m drag coefficient, and 10 m wind speed using data collected at two offshore observation towers (one over the sea and the other on an island) from seven typhoon episodes in the South China Sea from 2008 to 2014. The two towers were placed in areas with different water depths along a shore-normal line. The depth of water at the tower over the sea averages about 15 m, and the depth of water near the island is about 10 m. The observed maximum 10 min average wind speed at a height of 10 m is about 32 m s⁻¹. Momentum fluxes derived from three methods (eddy covariance, inertial dissipation, and flux profile) are compared. The momentum fluxes derived from the flux profile method are larger (smaller) over the sea (on the island) than those from the other two methods. The relationship between the 10 m drag coefficient and the 10 m wind speed is examined by use of the data obtained by the eddy covariance method. The drag coefficient first decreases with increasing 10 m wind speed when the wind speeds are 5–10 m s⁻¹, then increases and reaches a peak value of 0.002 around a wind speed of 18 m s⁻¹. The drag coefficient decreases with increasing 10 m wind speed when 10 m wind speeds are 18–27 m s⁻¹. A comparison of the measurements from the two towers shows that the 10 m drag coefficient from the tower in 10 m water depth is about 40% larger than that from the tower in 15 m water depth when the 10 m wind speed is less than 10 m s⁻¹. Above this, the difference in the 10 m drag coefficients of the two towers disappears.
EMPIRICAL DETERMINATION OF EINSTEIN A-COEFFICIENT RATIOS OF BRIGHT [Fe II] LINES
Giannini, T.; Antoniucci, S.; Nisini, B.; Lorenzetti, D.; Alcal, J. M.; Bacciotti, F.; Podio, L.; Bonito, R.; Stelzer, B.
2015-01-01
The Einstein spontaneous rates (A-coefficients) of Fe{sup +} lines have been computed by several authors with results that differ from each other by up to 40%. Consequently, models for line emissivities suffer from uncertainties that in turn affect the determination of the physical conditions at the base of line excitation. We provide an empirical determination of the A-coefficient ratios of bright [Fe II] lines that would represent both a valid benchmark for theoretical computations and a reference for the physical interpretation of the observed lines. With the ESO-Very Large Telescope X-shooter instrument between 3000 and 24700 , we obtained a spectrum of the bright Herbig-Haro object HH1. We detect around 100 [Fe II] lines, some of which with a signal-to-noise ratios ?100. Among these latter lines, we selected those emitted by the same level, whose dereddened intensity ratios are direct functions of the Einstein A-coefficient ratios. From the same X-shooter spectrum, we got an accurate estimate of the extinction toward HH1 through intensity ratios of atomic species, H I recombination lines and H{sub 2} ro-vibrational transitions. We provide seven reliable A-coefficient ratios between bright [Fe II] lines, which are compared with the literature determinations. In particular, the A-coefficient ratios involving the brightest near-infrared lines (?12570/?16440 and ?13209/?16440) are in better agreement with the predictions by the Quinet et al. relativistic Hartree-Fock model. However, none of the theoretical models predict A-coefficient ratios in agreement with all of our determinations. We also show that literature data of near-infrared intensity ratios better agree with our determinations than with theoretical expectations.
Observed drag coefficients in high winds in the near offshore of the South China Sea
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bi, Xueyan; Liu, Yangan; Gao, Zhiqiu; Liu, Feng; Song, Qingtao; Huang, Jian; Huang, Huijun; Mao, Weikang; Liu, Chunxia
2015-07-14
This paper investigates the relationships between friction velocity, 10 m drag coefficient, and 10 m wind speed using data collected at two offshore observation towers (one over the sea and the other on an island) from seven typhoon episodes in the South China Sea from 2008 to 2014. The two towers were placed in areas with different water depths along a shore-normal line. The depth of water at the tower over the sea averages about 15 m, and the depth of water near the island is about 10 m. The observed maximum 10 min average wind speed at a heightmore » of 10 m is about 32 m s⁻¹. Momentum fluxes derived from three methods (eddy covariance, inertial dissipation, and flux profile) are compared. The momentum fluxes derived from the flux profile method are larger (smaller) over the sea (on the island) than those from the other two methods. The relationship between the 10 m drag coefficient and the 10 m wind speed is examined by use of the data obtained by the eddy covariance method. The drag coefficient first decreases with increasing 10 m wind speed when the wind speeds are 5–10 m s⁻¹, then increases and reaches a peak value of 0.002 around a wind speed of 18 m s⁻¹. The drag coefficient decreases with increasing 10 m wind speed when 10 m wind speeds are 18–27 m s⁻¹. A comparison of the measurements from the two towers shows that the 10 m drag coefficient from the tower in 10 m water depth is about 40% larger than that from the tower in 15 m water depth when the 10 m wind speed is less than 10 m s⁻¹. Above this, the difference in the 10 m drag coefficients of the two towers disappears.« less
Observed drag coefficients in high winds in the near offshore of the South China Sea
Bi, Xueyan; Liu, Yangan; Gao, Zhiqiu; Liu, Feng; Song, Qingtao; Huang, Jian; Huang, Huijun; Mao, Weikang; Liu, Chunxia
2015-07-14
This paper investigates the relationships between friction velocity, 10 m drag coefficient, and 10 m wind speed using data collected at two offshore observation towers (one over the sea and the other on an island) from seven typhoon episodes in the South China Sea from 2008 to 2014. The two towers were placed in areas with different water depths along a shore-normal line. The depth of water at the tower over the sea averages about 15 m, and the depth of water near the island is about 10 m. The observed maximum 10 min average wind speed at a height of 10 m is about 32 m s?. Momentum fluxes derived from three methods (eddy covariance, inertial dissipation, and flux profile) are compared. The momentum fluxes derived from the flux profile method are larger (smaller) over the sea (on the island) than those from the other two methods. The relationship between the 10 m drag coefficient and the 10 m wind speed is examined by use of the data obtained by the eddy covariance method. The drag coefficient first decreases with increasing 10 m wind speed when the wind speeds are 510 m s?, then increases and reaches a peak value of 0.002 around a wind speed of 18 m s?. The drag coefficient decreases with increasing 10 m wind speed when 10 m wind speeds are 1827 m s?. A comparison of the measurements from the two towers shows that the 10 m drag coefficient from the tower in 10 m water depth is about 40% larger than that from the tower in 15 m water depth when the 10 m wind speed is less than 10 m s?. Above this, the difference in the 10 m drag coefficients of the two towers disappears.
Lee, C.M.; Addy, H.E.; Bond, T.H.; Chun, K.S.
1987-01-01
The main objective of this report was to derive equations to estimate neat transfer coefficients in both the combustion chamber and coolant passage of a rotary engine. This was accomplished by making detailed temperature and pressure measurements in a direct-injection stratified-charge rotary engine under a range of conditions. For each specific measurement point, the local physical properties of the fluids were calculated. Then an empirical correlation of the coefficients was derived by using a multiple regression program. This correlation expresses the Nusselt number as a function of the Prandtl number and Reynolds number.
Bendib, A.; Tahraoui, A.; Bendib, K.; Mohammed El Hadj, K.; Hueller, S.
2005-03-01
The transport coefficients of fully ionized plasmas under the influence of a high-frequency electric field are derived solving numerically the electron Fokker-Planck equation using a perturbation method, parametrized as a function of the electron mean-free-path {lambda}{sub ei} compared to the spatial scales L. The isotropic and anisotropic contributions of the inverse bremsstrahlung heating are considered. Electron-electron collision terms are kept in the analysis, which allows us to consider with sufficient accuracy to describe plasmas with arbitrary atomic number Z. Practical numerical fits of the transport coefficients are proposed as functions of Z and the collisionality parameter {lambda}{sub ei}/L.
Metastable Changes to the Temperature Coefficients of Thin-Film Photovoltaic Modules
Deceglie, M. G.; Silverman, T. J.; Marion, B.; Kurtz, S. R.
2014-07-01
Transient changes in the performance of thin-film modules with light exposure are a well-known and widely reported phenomenon. These changes are often the result of reversible metastabilities rather than irreversible changes. Here we consider how these metastable changes affect the temperature dependence of photovoltaic performance. We find that in CIGS modules exhibiting a metastable increase in performance with light exposure, the light exposure also induces an increase in the magnitude of the temperature coefficient. It is important to understand such changes when characterizing temperature coefficients and when analyzing the outdoor performance of newly installed modules.
Diffusion coefficients of Fokker-Planck equation for rotating dust grains in a fusion plasma
Bakhtiyari-Ramezani, M. Alinejad, N.; Mahmoodi, J.
2015-11-15
In the fusion devices, ions, H atoms, and H{sub 2} molecules collide with dust grains and exert stochastic torques which lead to small variations in angular momentum of the grain. By considering adsorption of the colliding particles, thermal desorption of H atoms and normal H{sub 2} molecules, and desorption of the recombined H{sub 2} molecules from the surface of an oblate spheroidal grain, we obtain diffusion coefficients of the Fokker-Planck equation for the distribution function of fluctuating angular momentum. Torque coefficients corresponding to the recombination mechanism show that the nonspherical dust grains may rotate with a suprathermal angular velocity.
Evaluation of Pseudo-Static Coefficients According to Performance-Based Criteria
Biondi, Giovanni; Maugeri, Michele; Cascone, Ernesto
2008-07-08
A rational procedure is presented for the selection of the equivalent seismic coefficient to be introduced in the pseudo-static analysis of geotechnical systems which, at failure, behave as a 1-degree of freedom system. It is shown that although pseudo-static and displacement analyses may be regarded as alternative methods of analysis, the seismic coefficient may be related to earthquake-induced permanent displacements and, then, to the expected level of damage. Following the proposed procedure a pseudo-static analysis in accordance with performance based design can be carried out.
Gibson, LaTosha M; Gopalan, Balaji; Pisupati, Sarma V; Shadle, Lawrence J
2013-10-01
New robust Lagrangian computational fluid dynamic (CFD) models are powerful tools that can be used to study the behavior of a diverse population of coal particle sizes, densities, and mineral compositions in entrained gasifiers. By using this approach, the responses of the particles impacting the wall were characterized over a range of velocities (1 to 8 m/s) and incident angles (90 to 20°). Within CFD models, the kinematic coefficient of restitution is the boundary condition defining the particle wall behavior. Four surfaces were studied to simulate the physical conditions of different entrained-flow gasification particle–surface collision scenarios: 1) a flat metal plate 2) a low viscosity silicon adhesive, 3) a high viscosity silicon adhesive, and 4) adhered particles on a flat metal plate with Young's modulus of elasticity ranging from 0.9 to 190 GPa. Entrained flow and drop experiments were conducted with granular coke particles, polyethylene beads and polystyrene pellets. The particle normal and tangential coefficients of restitution were measured using high speed imaging and particle tracking. The measured coefficients of restitution were observed to have a strong dependence on the rebound angles for most of the data. Suitable algebraic expressions for the normal and the tangential component of the coefficient of restitution were developed based upon ANOVA analysis. These expressions quantify the effect of normalized Young's modulus, particle equancy, and relative velocity on the coefficient of restitution. The coefficient of restitution did not have a strong dependence on the particle velocity over the range considered as long as the velocity was above the critical velocity. However, strong correlations were found between the degree of equancy of the particles and the mean coefficient of restitution such that the coefficient of restitution decreased for smaller particle equancies. It was concluded that the degree of equancy and the normalized Young
Role of self-trapped holes in the photoconductive gain of β-gallium oxide Schottky diodes
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Armstrong, Andrew M.; Crawford, Mary H.; Jayawardena, Asanka; Ahyi, Ayayi; Dhar, Sarit
2016-03-10
Solar-blind photodetection and photoconductive gain > 50 corresponding to a responsivity > 8 A/W was observed for β-Ga2O3 Schottky photodiodes. We investigated the origin of photoconductive gain. Current-voltage characteristics of the diodes did not indicate avalanche breakdown, which excludes carrier multiplication by impact ionization as the source for gain. However, photocapacitance measurements indicated a mechanism for hole localization for above-band gap illumination, suggesting self-trapped hole formation. Comparison of photoconductivity and photocapacitance spectra indicated that self-trapped hole formation coincides with the strong photoconductive gain. We conclude that self-trapped hole formation near the Schottky diode lowers the effective Schottky barrier in reversemore » bias, producing photoconductive gain. Ascribing photoconductive gain to an inherent property like self-trapping of holes can explain the operation of a variety of β-Ga2O3 photodetectors.« less
Robust random number generation using steady-state emission of gain-switched laser diodes
Yuan, Z. L. Lucamarini, M.; Dynes, J. F.; Frhlich, B.; Plews, A.; Shields, A. J.
2014-06-30
We demonstrate robust, high-speed random number generation using interference of the steady-state emission of guaranteed random phases, obtained through gain-switching a semiconductor laser diode. Steady-state emission tolerates large temporal pulse misalignments and therefore significantly improves the interference quality. Using an 8-bit digitizer followed by a finite-impulse-response unbiasing algorithm, we achieve random number generation rates of 8 and 20?Gb/s, for laser repetition rates of 1 and 2.5?GHz, respectively, with a 20% tolerance in the interferometer differential delay. We also report a generation rate of 80?Gb/s using partially phase-correlated short pulses. In relation to the field of quantum key distribution, our results confirm the gain-switched laser diode as a suitable light source, capable of providing phase-randomized coherent pulses at a clock rate of up to 2.5?GHz.
Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates
Shapiro, C.; Magee, A.; Zoeller, W.
2013-02-01
The Consortium for Advanced Residential Buildings (CARB) monitored three houses in Jacksonville, FL, to investigate the effectiveness of encapsulated and encapsulated/buried ducts in reducing thermal losses and gains from ductwork in unconditioned attics. Burying ductwork beneath loose-fill insulation has been identified as an effective method of reducing thermal losses and gains from ductwork in dry climates, but it is not applicable in humid climates where condensation may occur on the outside of the duct jacket. By encapsulating the ductwork in closed cell polyurethane foam (ccSPF) before burial beneath loose-fill mineral fiber insulation, the condensation potential may be reduced while increasing the R-value of the ductwork.
A bootstrapped, low-noise, and high-gain photodetector for shot noise measurement
Zhou, Haijun; Yang, Wenhai; Li, Zhixiu; Li, Xuefeng; Zheng, Yaohui
2014-01-15
We presented a low-noise, high-gain photodetector based on the bootstrap structure and the L-C (inductance and capacitance) combination. Electronic characteristics of the photodetector, including electronic noise, gain and frequency response, and dynamic range, were verified through a single-frequency Nd:YVO{sub 4} laser at 1064 nm with coherent output. The measured shot noise of 50 μW laser was 13 dB above the electronic noise at the analysis frequency of 2 MHz, and 10 dB at 3 MHz. And a maximum clearance of 28 dB at 2 MHz was achieved when 1.52 mW laser was illuminated. In addition, the photodetector showed excellent linearities for both DC and AC amplifications in the laser power range between 12.5 μW and 1.52 mW.
Prediction of internal temperature swings in direct-gain passive-solar buildings
Balcomb, J.D.
1983-01-01
The diurnal heat capacity method is presented for estimating inside-temperature swings attributable to direct winter solar gain. The procedures are simplified to be suitable for hand analysis, aided by tables of diurnal heat capacity for various materials. The method has been spot checked against computer simulation and has been used successfully by a group of 20 builders in New Mexico to analyze whether temperature swings would be excessive in their designs.
Are there Gains from Pooling Real-Time Oil Price Forecasts?
U.S. Energy Information Administration (EIA) Indexed Site
Are there Gains from Pooling Real- Time Oil Price Forecasts? Christiane Baumeister, Bank of Canada Lutz Kilian, University of Michigan Thomas K. Lee, U.S. Energy Information Administration February 12, 2014 Independent Statistics & Analysis www.eia.gov U.S. Energy Information Administration Washington, DC 20585 This paper is released to encourage discussion and critical comment. The analysis and conclusions expressed here are those of the authors and not necessarily those of the U.S. Energy
Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain
Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul
2010-05-14
Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective 'cool colored' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland U.S. latitudes, this metric RE891BN can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {le} 5:12 [23{sup o}]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool-roof net energy savings by as much as 23%. We define clear-sky air mass one global horizontal ('AM1GH') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer.
Broader source: Energy.gov [DOE]
A remote authenticated user can gain elevated privileges. A remote authenticated user can inject SQL commands. A remote user can spoof connections in certain cases.
Mass transfer coefficients developed from the air gasification of wood pellets
Botts, J.W.
1998-07-01
A convertible updraft/downdraft, fixed-bed gasifier was used in the gasification of 3/8-inch diameter wood pellets. The test data was used to develop mass transfer coefficients and describe the gasification process for each gasifier configuration. The results show that the production of the principal combustion gases, i.e., hydrogen (H{sub c}), carbon monozide (CO), and methane (CH{sub 4}), varies directly as to their mass transfer coefficient: H{sub 2}, CO, and CH{sub 4} = k h{sub DA}. Factoring the Reynolds (Re{sub d}) and Schmidt (Sc) numbers with the influence of the noncombustible gases, i.e., nitrogen (N{sub 2}), oxygen (O{sub 2}), and carbon dioxide (CO{sub 2}), is used to define the mass transfer coefficients. The general form describing this joint variation is: H{sub 2}, CO, and CH{sub 4} = kx (the effect of the noncombustible gases) x Re x Sc where Re = Reynolds number and Sc = Schmidt number. The developments of these mass transfer coefficients are shown for updraft and downdraft gasification.
Gas Chromatography Data Classification Based on Complex Coefficients of an Autoregressive Model
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhao, Weixiang; Morgan, Joshua T.; Davis, Cristina E.
2008-01-01
This paper introduces autoregressive (AR) modeling as a novel method to classify outputs from gas chromatography (GC). The inverse Fourier transformation was applied to the original sensor data, and then an AR model was applied to transform data to generate AR model complex coefficients. This series of coefficients effectively contains a compressed version of all of the information in the original GC signal output. We applied this method to chromatograms resulting from proliferating bacteria species grown in culture. Three types of neural networks were used to classify the AR coefficients: backward propagating neural network (BPNN), radial basis function-principal component analysismore » (RBF-PCA) approach, and radial basis function-partial least squares regression (RBF-PLSR) approach. This exploratory study demonstrates the feasibility of using complex root coefficient patterns to distinguish various classes of experimental data, such as those from the different bacteria species. This cognition approach also proved to be robust and potentially useful for freeing us from time alignment of GC signals.« less
GRIGSBY KM
2011-04-07
This report presents the atmospheric dispersion coefficients used in Tank Farms safety analysis. The basis equations for calculating radiological and toxicological exposures are also included. In this revision, the time averaging for toxicological consequence evaluations is clarified based on a review of DOE complex guidance and a review of tank farm chemicals.
FIELD-SCALE EFFECTIVE MATRIX DIFFUSION COEFFICIENT FOR FRACTURED ROCK:RESULTS FROM LITERATURE SURVEY
Q. Zhou; Hui-Hai Liu; F.J. Molz; Y. Zhang; G.S. Bodvarsson
2005-04-08
Matrix diffusion is an important mechanism for solute transport in fractured rock. We recently conducted a literature survey on the effective matrix diffusion coefficient, D{sub m}{sup e}, a key parameter for describing matrix diffusion processes at the field scale. Forty field tracer tests at 15 fractured geologic sites were surveyed and selected for the study, based on data availability and quality. Field-scale D{sub m}{sup e} values were calculated, either directly using data reported in the literature or by reanalyzing the corresponding field tracer tests. Surveyed data indicate that the effective-matrix-diffusion-coefficient factor F{sub D} (defined as the ratio of D{sub m}{sup e} to the lab-scale matrix diffusion coefficient [D{sub m}] of the same tracer) is generally larger than one, indicating that the effective matrix diffusion coefficient in the field is comparatively larger than the matrix diffusion coefficient at the rock-core scale. This larger value can be attributed to the many mass-transfer processes at different scales in naturally heterogeneous, fractured rock systems. Furthermore, we observed a moderate trend toward systematic increase in the F{sub D} value with observation scale, indicating that the effective matrix diffusion coefficient is likely to be statistically scale dependent. The F{sub D} value ranges from 1 to 10,000 for observation scales from 5 to 2,000 m. At a given scale, the F{sub D} value varies by two orders of magnitude, reflecting the influence of differing degrees of fractured rock heterogeneity at different sites. In addition, the surveyed data indicate that field-scale longitudinal dispersivity generally increases with observation scale, which is consistent with previous studies. The scale-dependent field-scale matrix diffusion coefficient (and dispersivity) may have significant implications for assessing long-term, large-scale radionuclide and contaminant transport events in fractured rock, both for nuclear waste disposal
Field-Scale Effective Matrix Diffusion Coefficient for FracturedRock: Results From Literature Survey
Zhou, Quanlin; Liu, Hui Hai; Molz, Fred J.; Zhang, Yingqi; Bodvarsson, Gudmundur S.
2005-03-28
Matrix diffusion is an important mechanism for solutetransport in fractured rock. We recently conducted a literature survey onthe effective matrix diffusion coefficient, Dem, a key parameter fordescribing matrix diffusion processes at the field scale. Forty fieldtracer tests at 15 fractured geologic sites were surveyed and selectedfor study, based on data availability and quality. Field-scale Dem valueswere calculated, either directly using data reported in the literature orby reanalyzing the corresponding field tracer tests. Surveyed dataindicate that the effective-matrix-diffusion-coefficient factor FD(defined as the ratio of Dem to the lab-scale matrix diffusioncoefficient [Dem]of the same tracer) is generally larger than one,indicating that the effective matrix diffusion coefficient in the fieldis comparatively larger than the matrix diffusion coefficient at therock-core scale. This larger value could be attributed to the manymass-transfer processes at different scales in naturally heterogeneous,fractured rock systems. Furthermore, we observed a moderate trend towardsystematic increase in the emDFmDDF value with observation scale,indicating that the effective matrix diffusion coefficient is likely tobe statistically scale dependent. The FD value ranges from 1 to 10,000for observation scales from 5 to 2,000 m. At a given scale, the FD valuevaries by two orders of magnitude, reflecting the influence of differingdegrees of fractured rock heterogeneity at different sites. In addition,the surveyed data indicate that field-scale longitudinal dispersivitygenerally increases with observation scale, which is consistent withprevious studies. The scale-dependent field-scale matrix diffusioncoefficient (and dispersivity) may have significant implications forassessing long-term, large-scale radionuclide and contaminant transportevents in fractured rock, both for nuclear waste disposal and contaminantremediation.
Bhadra, S; Hertzberg, BJ; Hsieh, AG; Croft, M; Gallaway, JW; Van Tassell, BJ; Chamoun, M; Erdonmez, C; Zhong, Z; Sholklapper, T; Steingart, DA
2015-01-01
The coefficient of restitution of alkaline batteries has been shown to increase as a function of depth of discharge. In this work, using non-destructive mechanical testing, the change in coefficient of restitution is compared to in situ energy-dispersive X-ray diffraction data to determine the cause of the macroscopic change in coefficient of restitution. The increase in coefficient of restitution correlates to the formation of a percolation pathway of ZnO within the anode of the cell, and the coefficient of restitution levels off at a value of 0.66 +/- 0.02 at 50% state of charge when the anode has densified into porous ZnO solid. Of note is the sensitivity of coefficient of restitution to the amount of ZnO formation that rivals the sensitivity of in situ energy-dispersive X-ray diffraction.
NREL Solar Research Gains Two R&D 100 Awards - News Releases | NREL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Solar Research Gains Two R&D 100 Awards July 17, 2008 An ultra-light, highly efficient solar cell and use of ink-jet printing to manufacture thin-film photovoltaics-both developed at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory-have been named among this year's most significant innovations by Research & Development (R&D) Magazine. Known as "the Oscars of Invention," the R&D 100 Award showcases the most significant new technologies
The effects of changing exercise levels on weight and age-relatedweight gain
Williams, Paul T.; Wood, Peter D.
2004-06-01
To determine prospectively whether physical activity canprevent age-related weight gain and whether changing levels of activityaffect body weight. DESIGN/SUBJECTS: The study consisted of 8,080 maleand 4,871 female runners who completed two questionnaires an average(+/-standard deviation (s.d.)) of 3.20+/-2.30 and 2.59+/-2.17 yearsapart, respectively, as part of the National Runners' Health Study.RESULTS: Changes in running distance were inversely related to changes inmen's and women's body mass indices (BMIs) (slope+/-standard error(s.e.): -0.015+/-0.001 and -0.009+/-0.001 kg/m(2) per Deltakm/week,respectively), waist circumferences (-0.030+/-0.002 and -0.022+/-0.005 cmper Deltakm/week, respectively) and percent changes in body weight(-0.062+/-0.003 and -0.041+/-0.003 percent per Deltakm/week,respectively, all P<0.0001). The regression slopes were significantlysteeper (more negative) in men than women for DeltaBMI and Deltapercentbody weight (P<0.0001). A longer history of running diminishedthe impact of changing running distance on men's weights. When adjustedfor Deltakm/week, years of aging in men and years of aging in women wereassociated with increases of 0.066+/-0.005 and 0.056+/-0.006 kg/m(2) inBMI, respectively, increases of 0.294+/-0.019 and 0.279+/-0.028 percentin Delta percentbody weight, respectively, and increases of 0.203+/-0.016and 0.271+/-0.033 cm in waist circumference, respectively (allP<0.0001). These regression slopes suggest that vigorous exercise mayneed to increase 4.4 km/week annually in men and 6.2 km/week annually inwomen to compensate for the expected gain in weight associated with aging(2.7 and 3.9 km/week annually when correct for the attenuation due tomeasurement error). CONCLUSIONS: Age-related weight gain occurs evenamong the most active individuals when exercise is constant.Theoretically, vigorous exercise must increase significantly with age tocompensate for the expected gain in weight associated withaging.
Analysis of FEL-based CeC amplification at high gain limit
Wang, G.; Litvinenko, V.; Jing, Y.
2015-05-03
An analysis of Coherent electron Cooling (CeC) amplifier based on 1D Free Electron Laser (FEL) theory was previously performed with exact solution of the dispersion relation, assuming electrons having Lorentzian energy distribution. At high gain limit, the asymptotic behavior of the FEL amplifier can be better understood by Taylor expanding the exact solution of the dispersion relation with respect to the detuning parameter. In this work, we make quadratic expansion of the dispersion relation for Lorentzian energy distribution and investigate how longitudinal space charge and electrons’ energy spread affect the FEL amplification process.
Possible energy gain for a plasma-liner-driven magneto-inertial fusion concept
Knapp, C. E.; Kirkpatrick, R. C.
2014-07-15
A one-dimensional parameter study of a Magneto-Inertial Fusion (MIF) concept indicates that significant gain may be achievable. This concept uses a dynamically formed plasma shell with inwardly directed momentum to drive a magnetized fuel to ignition, which in turn partially burns an intermediate layer of unmagnetized fuel. The concept is referred to as Plasma Jet MIF or PJMIF. The results of an adaptive mesh refinement Eulerian code (Crestone) are compared to those of a Lagrangian code (LASNEX). These are the first published results using the Crestone and LASNEX codes on the PJMIF concept.
Method and system for modulation of gain suppression in high average power laser systems
Bayramian, Andrew James
2012-07-31
A high average power laser system with modulated gain suppression includes an input aperture associated with a first laser beam extraction path and an output aperture associated with the first laser beam extraction path. The system also includes a pinhole creation laser having an optical output directed along a pinhole creation path and an absorbing material positioned along both the first laser beam extraction path and the pinhole creation path. The system further includes a mechanism operable to translate the absorbing material in a direction crossing the first laser beam extraction laser path and a controller operable to modulate the second laser beam.
Frequency dependence of mass flow gain factor and cavitation compliance of cavitating inducers
Otsuka, S.; Tsujimoto, Yoshinobu [Osaka Univ. (Japan); Kamijo, Kenjiro [National Aerospace Lab., Kakuda, Miyagi (Japan). Kakuda Research Center; Furuya, O. [AMP Technologies, Osaka (Japan)
1994-12-31
Unsteady cavitation characteristics are analyzed based on a closed cavity model in which the length of the cavity is allowed to oscillate. It is shown that the present model blends smoothly into quasisteady calculations in the low frequency limit, unlike fixed cavity length models. Effects of incidence angle and cavitation number on cavitation compliance and mass flow gain factor are shown as functions of reduce frequency. The cavity volume is evaluated by three methods and the results were used to confirm the accuracy and adequacy of the numerical calculation. By comparison with experimental data on inducers, it was shown that the present model can simulate the characteristics of unsteady cavitation qualitatively.
Futatani, Shimpei; Bos, Wouter J. T.; Morales, Jorge A.
2015-05-15
It can be shown that in the presence of a toroidal magnetic field induced by poloidal coils, combined with the electromagnetic field induced by a central solenoid, no static equilibrium is possible within the MHD description, as soon as non-zero resistivity is assumed. The resulting dynamic equilibrium was previously discussed for the case of spatially homogeneous resisitivity. In the present work, it is shown how a spatial inhomogeneity of the viscosity and resisitivity coefficients influences this equilibrium. Parameters in both the stable, tokamak-like regime and unstable, reversed field pinch-like regime are considered. It is shown that, whereas the magnitudes of the velocity and magnetic field fluctuations are strongly modified by the spatial variation of the transport coefficients, the qualitative flow behaviour remains largely unaffected.
Temperature coefficients for GaInP/GaAs/GaInNAsSb solar cells
Aho, Arto; Isoaho, Riku; Tukiainen, Antti; Polojärvi, Ville; Aho, Timo; Raappana, Marianna; Guina, Mircea
2015-09-28
We report the temperature coefficients for MBE-grown GaInP/GaAs/GaInNAsSb multijunction solar cells and the corresponding single junction sub-cells. Temperature-dependent current-voltage measurements were carried out using a solar simulator equipped with a 1000 W Xenon lamp and a three-band AM1.5D simulator. The triple-junction cell exhibited an efficiency of 31% at AM1.5G illumination and an efficiency of 37–39% at 70x real sun concentration. The external quantum efficiency was also measured at different temperatures. The temperature coefficients up to 80°C, for the open circuit voltage, the short circuit current density, and the conversion efficiency were determined to be −7.5 mV/°C, 0.040 mA/cm{sup 2}/°C, and −0.09%/°C, respectively.
On a regularization of a scalar conservation law with discontinuous coefficients
Shen, Chun
2014-03-15
This paper is devoted to a scalar conservation law with a linear flux function involving discontinuous coefficients. It is clear that the delta standing wave should be introduced into the Riemann solution in some nonclassical situation. In order to study the formation of delta standing wave, we consider a regularization of the discontinuous coefficient with the Helmholtz mollifier and then obtain a regularized system which depends on a regularization parameter ε > 0. The regularization mechanism is a nonlinear bending of characteristic curves that prevents their finite-time intersection. It is proved rigorously that the solutions of regularized system converge to the delta standing wave solution in the ε → 0 limit. Compared with the classical method of vanishing viscosity, here it is clear to see how the delta standing wave forms naturally along the characteristics.
Three-body interactions in complex fluids: Virial coefficients from simulation finite-size effects
Ashton, Douglas J.; Wilding, Nigel B.
2014-06-28
A simulation technique is described for quantifying the contribution of three-body interactions to the thermodynamical properties of coarse-grained representations of complex fluids. The method is based on a new approach for determining virial coefficients from the measured volume-dependent asymptote of a certain structural function. By comparing the third virial coefficient B{sub 3} for a complex fluid with that of an approximate coarse-grained model described by a pair potential, three body effects can be quantified. The strategy is applicable to both Molecular Dynamics and Monte Carlo simulation. Its utility is illustrated via measurements of three-body effects in models of star polymers and in highly size-asymmetrical colloid-polymer mixtures.
Werner, Thomas R.; Falco, Charles M.; Schuller, Ivan K.
1984-01-01
A thin film resistor having a controlled temperature coefficient of resistance (TCR) ranging from negative to positive degrees kelvin and having relatively high resistivity. The resistor is a multilayer superlattice crystal containing a plurality of alternating, ultra-thin layers of two different metals. TCR is varied by controlling the thickness of the individual layers. The resistor can be readily prepared by methods compatible with thin film circuitry manufacturing techniques.
Investigation of photon attenuation coefficient of some building materials used in Turkey
Dogan, B.; Altinsoy, N.
2015-03-30
In this study, some building materials regularly used in Turkey, such as concrete, gas concrete, pumice and brick have been investigated in terms of mass attenuation coefficient at different gamma-ray energies. Measurements were carried out by gamma spectrometry containing NaI(Tl) detector. Narrow beam gamma-ray transmission geometry was used for the attenuation measurements. The results are in good agreement with the theoretical calculation of XCOM code.
Partition coefficients for acetic, propionic, and butyric acids in a crude oil/water system
Reinsel, M.A.; Borkowski, J.J.; Sears, J.T. . National Science Foundation Engineering Research Center for Biofilm Engineering)
1994-07-01
The effects of pH, temperature, and organic acid concentration on the partition coefficients for short-chain organic acids were measured in a crude oil/water system. Acetic, propionic, and butyric acids, as probable substrates for microbial souring of oil reservoirs, were used in conjunction with two types of crude oil. Temperatures of 35--75 C, pH values of 4.0--7.0, and acid concentrations of 10--1,000 mg/L were studied. Initial naturally occurring levels of organic acids in the crude oils were also determined. pH had by far the largest effect on the partition coefficient for all three organic acids for both types oil. At conditions normally seen in an oil reservoir (pH 5--7), the great percentage (85+%) of these acids were dissolved in the aqueous phase. The log of the partition coefficient K increased approximately linearly with the number of carbon atoms in the acid. It was seen that organic acids are readily available carbon sources for sulfate-reducing bacteria (SRB) at normal reservoir conditions, and that crude oil may provide a source of organic acids in a low-pH, water-flooded reservoir.
A novel solution to the gated x-ray detector gain droop problem
Oertel, J. A. Archuleta, T. N.
2014-11-15
Microchannel plate (MCP), microstrip transmission line based, gated x-ray detectors used at the premier ICF laser facilities have a drop in gain as a function of mircostrip length that can be greater than 50% over 40 mm. These losses are due to ohmic losses in a microstrip coating that is less than the optimum electrical skin depth. The electrical skin depth for a copper transmission line at 3 GHz is 1.2 μm while the standard microstrip coating thickness is roughly half a single skin depth. Simply increasing the copper coating thickness would begin filling the MCP pores and limit the number of secondary electrons created in the MCP. The current coating thickness represents a compromise between gain and ohmic loss. We suggest a novel solution to the loss problem by overcoating the copper transmission line with five electrical skin depths (∼6 μm) of Beryllium. Beryllium is reasonably transparent to x-rays above 800 eV and would improve the carrier current on the transmission line. The net result should be an optically flat photocathode response with almost no measurable loss in voltage along the transmission line.
Progress in laboratory high gain ICF (inertial confinement fusion): Prospects for the future
Storm, E.; Lindl, J.D.; Campbell, E.M.; Bernat, T.P.; Coleman, L.W.; Emmett, J.L.; Hogan, W.J.; Hunt, J.T.; Krupke, W.F.; Lowdermilk, W.H.
1988-01-01
Inertial confinement fusion (ICF), a thermonuclear reaction in a small (/approximately/5 mm diameter) fuel capsule filled with a few milligrams of deuterium and tritium, has been the subject of very fruitful experimentation since the early 1970's. High gain ICF is now on the threshold of practical applications. With a Laboratory Microfusion Facility (LMF), these applications will have major implications for national defense, basic and applied science, and power production. With a driver capable of delivering about 10 MJ in a 10-ns pulse at an intensity of /approximately/3 /times/ 10/sup 14/ W/cm/sup 2/, an appropriately configured cryogenic capsule could be compressed to a density of about 200 g/cm/sup 3/ and a temperature of 3--5 keV. Under these conditions, up to 10 mg of DT could be ignited, and with a burn efficiency of about 30%, release up to 1000 MJ of fusion energy, an energy gain of about 100. A thousand megajoules is equivalent to about one quarter ton of TNT, or about 7 gallons of oil--an amount of energy tractable under laboratory conditions and potentially very useful for a variety of applications. 61 refs., 33 figs.
9 GeV energy gain in a beam-driven plasma wakefield accelerator
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Litos, M.; Adli, E.; Allen, J. M.; An, W.; Clarke, C. I.; Corde, S.; Clayton, C. E.; Frederico, J.; Gessner, S. J.; Green, S. Z.; et al
2016-02-15
An electron beam has gained a maximum energy of 9 GeV per particle in a 1.3 m-long electron beam-driven plasma wakefield accelerator. The amount of charge accelerated in the spectral peak was 28.3 pC, and the root-mean-square energy spread was 5.0%. The mean accelerated charge and energy gain per particle of the 215 shot data set was 115 pC and 5.3 GeV, respectively, corresponding to an acceleration gradient of 4.0 GeV m-1 at the spectral peak. Moreover, the mean energy spread of the data set was 5.1%. Our results are consistent with the extrapolation of the previously reported energy gainmore » results using a shorter, 36 cm-long plasma source to within 10%, evincing a non-evolving wake structure that can propagate distances of over a meter in length. Wake-loading effects were evident in the data through strong dependencies observed between various spectral properties and the amount of accelerated charge.« less
Patterns and Implications of Gene Gain and Loss in the Evolution of Prochlorococcus
Lapidus, Alla; Kettler, Gregory C.; Martiny, Adam C.; Huang, Katherine; Zucker, Jeremy; Coleman, Maureen L.; Rodrigue, Sebastien; Chen, Feng; Lapidus, Alla; Ferriera, Steven; Johnson, Justin; Steglich, Claudia; Church, George M.; Richardson, Paul; Chisholm, Sallie W.
2007-07-30
Prochlorococcus is a marine cyanobacterium that numerically dominates the mid-latitude oceans and is the smallest known oxygenic phototroph. Numerous isolatesfrom diverse areas of the world's oceans have been studied and shown to be physiologically and genetically distinct. All isolates described thus far can be assigned to either a tightly clustered high-light (HL)-adapted clade, or a more divergent low-light (LL)-adapted group. The 16S rRNA sequences of the entire Prochlorococcus group differ by at most 3percent, and the four initially published genomes revealed patterns of genetic differentiation that help explain physiological differences among the isolates. Here we describe the genomes of eight newly sequenced isolates and combine them with the first four genomes for a comprehensive analysis of the core (shared by all isolates) and flexible genes of the Prochlorococcus group, and the patterns of loss and gain of the flexible genes over the course of evolution. There are 1,273 genes that represent the core shared by all 12 genomes. They are apparently sufficient, according to metabolic reconstruction, to encode a functional cell. We describe a phylogeny for all 12 isolates by subjecting their complete proteomes to three different phylogenetic analyses. For each non-core gene, we used a maximum parsimony method to estimate which ancestor likely first acquired or lost each gene. Many of the genetic differences among isolates, especially for genes involved in outer membrane synthesis and nutrient transport, are found within the same clade. Nevertheless, we identified some genes defining HL and LL ecotypes, and clades within these broad ecotypes, helping to demonstrate the basis of HL and LL adaptations in Prochlorococcus. Furthermore, our estimates of gene gain events allow us to identify highly variable genomic islands that are not apparent through simple pairwise comparisons. These results emphasize the functional roles, especially those connected to outer
Hodges residence: performance of a direct gain passive solar home in Iowa
Hodges, L.
1980-01-01
Results are presented for the performance of the Hodges residence, a 2200-square-foot earth-sheltered direct gain passive solar home in Ames, Iowa, during the 1979-80 heating season, its first occupied season. No night insulation was used on its 500 square feet of double-pane glass. Total auxiliary heat required was 43 GJ (41 MBtu) gross and 26 GJ (25 MBtu) net, amounting, respectively, to 60 and 36 kJ/C/sup 0/-day-m/sup 2/ (2.9 and 1.8 Btu/F/sup 0/-day-ft/sup 2/). The heating season was unusually cloudy and included the cloudiest January in the 21 years of Ames insolation measurements. Results are also presented for the performance of the hollowcore floor which serves as the main storage mass and for the comfort range in the house.
Hodges residence: performance of a direct gain passive solar home in Iowa
Hodges, L.
1980-01-01
Results are presented for the performance of the Hodges Residence, a 2200-square-foot earth-sheltered direct gain passive solar home in Ames, Iowa, during the 1979-80 heating season, its first occupied season. No night insulation was used on its 500 square feet of double-pane glass. Total auxiliary heat required was 43 GJ (41 MBTU) gross and 26 GJ (25 MBTU) net, amounting, respectively, to 60 and 36 kJ/C/sup 0/-day-m/sup 2/ (2.9 and 1.8 BTU/F/sup 0/-day-ft/sup 2/). The heating season was unusually cloudy and included the cloudiest January in the 21 years of Ames insolation measurements. Results are also presented for the performance of the hollow-core floor which serves as the main storage mass and for the comfort range in the house.
Diurnal heat storage in direct-gain passive-solar buildings
Balcomb, J.D.; Neeper, D.A.
1983-01-01
This paper presents a simplified method for predicting temperature swings in direct-gain buildings. It is called the DHC method due to the use of a diurnal heat capacity (DHC). Diurnal heat capacity is a measure of the effective amount of heat stored during a sunny day and then released at night - the typical 24-hour diurnal cycle. This enables prediction of the maximum temperature swings experienced in the building and can be calculated using a single 24-hour harmonic. The advantage is that closed-form analytic solutions can be obtained for a variety of simple and layered-wall configurations. Higher harmonic components are accounted for by a correction factor. The method is suitable for us by hand or on a programmable calculator.
Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.
1997-01-01
The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention provides a method for increasing the rate of strength gain of a hardenable mixture containing fly ash by exposing the fly ash to an aqueous slurry of calcium oxide (lime) prior to its incorporation into the hardenable mixture. The invention further relates to such hardenable mixtures, e.g., concrete and mortar, that contain fly ash pre-reacted with calcium oxide. In particular, the fly ash is added to a slurry of calcium oxide in water, prior to incorporating the fly ash in a hardenable mixture. The hardenable mixture may be concrete or mortar. In a specific embodiment, mortar containing fly ash treated by exposure to an aqueous lime slurry are prepared and tested for compressive strength at early time points.
Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.
1997-10-28
The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention provides a method for increasing the rate of strength gain of a hardenable mixture containing fly ash by exposing the fly ash to an aqueous slurry of calcium oxide (lime) prior to its incorporation into the hardenable mixture. The invention further relates to such hardenable mixtures, e.g., concrete and mortar, that contain fly ash pre-reacted with calcium oxide. In particular, the fly ash is added to a slurry of calcium oxide in water, prior to incorporating the fly ash in a hardenable mixture. The hardenable mixture may be concrete or mortar. In a specific embodiment, mortar containing fly ash treated by exposure to an aqueous lime slurry are prepared and tested for compressive strength at early time points. 2 figs.
Tsai, Cheng; Douglas, David R.; Li, Rui
2015-09-01
The coherent synchrotron radiation (CSR) of a high brightness electron beam traversing a series of dipoles, such as transport or recirculation arcs, may result in the microbunching instability (?BI). To accurately quantify the direct consequence of this effect, we further extend our previously developed semi-analytical Vlasov solver to include more relevant coherent radiation models than the steady-state free-space CSR impedance, such as the entrance and exit transient effects derived from upstream beam entering to and exiting from individual dipoles. The resultant microbunching gain functions and spectra for our example lattices are presented and compared with particle tracking simulation. Some underlying physics with inclusion of these effects are also discussed.
Fast iterative technique for the calculation of frequency dependent gain in excimer laser amplifiers
Sze, R.C.
1991-01-01
The motivation in initiating these calculations is to allow us to observe the frequency evolution of a laser pulse as it propagates through an amplifier and then through a sequence of amplifiers. The question we seek to answer is what pulse shape do we need to produce out of a front-end oscillator so that after it propagates through the whole Aurora KrF fusion amplifier chain will result in high energy, broad-band laser fields of a given bandwidth that can be focussed onto a fusion target. The propagation of a single frequency source through an amplifier with distributed loss was considered by Rigrod and was significantly expanded by Hunter and Hunter. The latter included amplified spontaneous emission (ASE) considerations both in the direction of and transverse to the coherent field. Analytic solutions that include forward and backward prapagating fields and ASE were derived which were transcendental in nature but allowed for fairly easy computer calculations. Transverse ASE were calculated using the unsaturated gain resulting from longitudinal fields and were used to compare this with the longitudinal field equations. Large computer programs are now available at LANL which include the influence of transverse ASE on the longitudinal fields. However, none of these considerations have worried about the changes in the frequency characteristics of the propagating field or of how each of the frequency field components contributes to the saturation of the gain. The inclusion of full frequency characteristics to the analytic solutions of Hunter and Hunter proved impossible at least for this author and a new calculational technique was developed and is the subject of this talk.
When and how does a prominence-like jet gain kinetic energy?
Liu, Jiajia; Liu, Rui; Zhang, Quanhao; Liu, Kai; Shen, Chenglong; Wang, S.; Wang, Yuming
2014-02-20
A jet is a considerable amount of plasma being ejected from the chromosphere or lower corona into the higher corona and is a common phenomenon. Usually, a jet is triggered by a brightening or a flare, which provides the first driving force to push plasma upward. In this process, magnetic reconnection is thought to be the mechanism to convert magnetic energy into thermal, nonthermal, and kinetic energies. However, most jets could reach an unusual high altitude and end much later than the end of its associated flare. This fact implies that there is another way to continuously transfer magnetic energy into kinetic energy even after the reconnection. The picture described above is well known in the community, but how and how much magnetic energy is released through a way other than reconnection is still unclear. By studying a prominence-like jet observed by SDO/AIA and STEREO-A/EUVI, we find that the continuous relaxation of the post-reconnection magnetic field structure is an important process for a jet to climb up higher than it could through only reconnection. The kinetic energy of the jet gained through the relaxation is 1.6 times that gained from the reconnection. The resultant energy flux is hundreds of times larger than the flux required for the local coronal heating, suggesting that such jets are a possible source to keep the corona hot. Furthermore, rotational motions appear all the time during the jet. Our analysis suggests that torsional Alfvn waves induced during reconnection could not be the only mechanism to release magnetic energy and drive jets.
Transverse piezoelectric coefficient measurement of flexible lead zirconate titanate thin films
Dufay, T.; Guiffard, B.; Seveno, R.; Thomas, J.-C.
2015-05-28
Highly flexible lead zirconate titanate, Pb(Zr,Ti)O{sub 3} (PZT), thin films have been realized by modified sol-gel process. The transverse piezoelectric coefficient d{sub 31} was determined from the tip displacement of bending-mode actuators made of PZT cantilever deposited onto bare or RuO{sub 2} coated aluminium substrate (16 μm thick). The influence of the thickness of ruthenium dioxide RuO{sub 2} and PZT layers was investigated for Pb(Zr{sub 0.57}Ti{sub 0.43})O{sub 3}. The modification of Zr/Ti ratio from 40/60 to 60/40 was done for 3 μm thick PZT thin films onto aluminium (Al) and Al/RuO{sub 2} substrates. A laser vibrometer was used to measure the beam displacement under controlled electric field. The experimental results were fitted in order to find the piezoelectric coefficient. Very large tip deflections of about 1 mm under low voltage (∼8 V) were measured for every cantilevers at the resonance frequency (∼180 Hz). For a given Zr/Ti ratio of 58/42, it was found that the addition of a 40 nm thick RuO{sub 2} interfacial layer between the aluminium substrate and the PZT layer induces a remarkable increase of the d{sub 31} coefficient by a factor of 2.7, thus corresponding to a maximal d{sub 31} value of 33 pC/N. These results make the recently developed PZT/Al thin films very attractive for both low frequency bending mode actuating applications and vibrating energy harvesting.
A time-domain estimation of wall conduction transfer function coefficients
Davies, M.G.
1996-11-01
The wall and roof transfer function coefficients, b{sub n} and d{sub n}, listed in the 1993 ASHRAE Fundamentals Handbook, have up to now been derived using laplace and Z-transform methods. This paper shows that they can be readily evaluated using straightforward time-domain solutions of the Fourier continuity equation. These include the response of a wall to a ramp increase in temperature and its transient response. The values of d{sub n} can be found from the first few terms in the series of wall decay times in the transient solution. The solutions are combined using a form of Fourier analysis. Appropriate layer transmission matrices enable one to find the wall`s overall characteristics readily. The wall response factors {phi}{sub j} can thus be found. The b{sub n} transfer coefficients are related to the {phi}{sub j} and d{sub n} values. The approach is illustrated using the data for wall group 6. Allowing for conversion from I-P to SI units, the present approach gives results that are almost identical to those listed. It shows, however, that the performance of the coefficients is very specific to the wall from which they were derived. The b{sub n} and d{sub n} values listed in the Handbook permit an estimate to be made of the wall response factors, including the time of peak flow and the first decay time. For heavy walls, however, values beyond d{sub 6} may be needed.
Lankford, Jr., James
1988-01-01
A method for producing a stable ceramic composition having a surface with a low friction coefficient and high wear resistance at high operating temperatures. A first deposition of a thin film of a metal ion is made upon the surface of the ceramic composition and then a first ion implantation of at least a portion of the metal ion is made into the near surface region of the composition. The implantation mixes the metal ion and the ceramic composition to form a near surface composite. The near surface composite is then oxidized sufficiently at high oxidizing temperatures to form an oxide gradient layer in the surface of the ceramic composition.
On the Reliability of Photovoltaic Short-Circuit Current Temperature Coefficient Measurements
Osterwald, Carl R.; Campanelli, Mark; Kelly, George J.; Williams, Rafell
2015-06-14
The changes in short-circuit current of photovoltaic (PV) cells and modules with temperature are routinely modeled through a single parameter, the temperature coefficient (TC). This parameter is vital for the translation equations used in system sizing, yet in practice is very difficult to measure. In this paper, we discuss these inherent problems and demonstrate how they can introduce unacceptably large errors in PV ratings. A method for quantifying the spectral dependence of TCs is derived, and then used to demonstrate that databases of module parameters commonly contain values that are physically unreasonable. Possible ways to reduce measurement errors are also discussed.
Zhang, Shuzeng; Li, Xiongbing; Jeong, Hyunjo Cho, Sungjong
2015-07-15
A novel method to determine acoustic parameters involved in measuring the nonlinearity parameter of fluids or solids is proposed. The approach is based on the measurement of fundamental and second harmonic pressures with a calibrated receiver, and on a nonlinear least squares data-fitting to multi-Gaussian beam (MGB) equations which explicitly define the attenuation and diffraction effects in the quasilinear regime. Results obtained in water validate the proposed method. The choice of suitable source pressure is discussed with regard to the quasilinear approximation involved. The attenuation coefficients are also acquired in nonlinear regime and their relations are discussed.
Stewart, M.; Lepadatu, S.; McCartney, L. N.; Cain, M. G.; Wright, L.; Crain, J.; Newns, D. M.; Martyna, G. J.
2015-02-01
The determination of the piezoelectric coefficient of thin films using interferometry is hindered by bending contributions. Using finite element analysis (FEA) simulations, we show that the Lefki and Dormans approximations using either single or double-beam measurements cannot be used with finite top electrode sizes. We introduce a novel method for characterising piezoelectric thin films which uses a differential measurement over the discontinuity at the electrode edge as an internal reference, thereby eliminating bending contributions. This step height is shown to be electrode size and boundary condition independent. An analytical expression is derived which gives good agreement with FEA predictions of the step height.
Williams, Paul T.
2006-01-06
Background: Body weight increases with aging. Short-term,longitudinal exercise training studies suggest that increasing exerciseproduces acute weight loss, but it is not clear if the maintenance oflong-term, vigorous exercise attenuates age-related weight gain inproportion to the exercise dose. Methods: Prospective study of 6,119 maleand 2,221 female runners whose running distance changed less than 5 km/wkbetween their baseline and follow-up survey 7 years later. Results: Onaverage, men who ran modest (0-24 km/wk), intermediate (24-48 km/wk) orprolonged distances (>_48 km/wk) all gained weight throughage 64,however, those who ran ?48 km/wk had one-half the average annual weightgain of those who ran<24 km/wk. Age-related weight gain, and itsreduction by running, were both greater in younger than older men. Incontrast, men s gain in waist circumference with age, and its reductionby running, were the same in older and younger men. Women increased theirbody weight and waist and hip circumferences over time, regardless ofage, which was also reduced in proportion to running distance. In bothsexes, running did not attenuate weight gain uniformly, but ratherdisproportionately prevented more extreme increases. Conclusion: Men andwomen who remain vigorously active gain less weight as they age and thereduction is in proportion to the exercise dose.
Gallagher, S.M.; Curran, H.J.; Metcalfe, W.K.; Healy, D.; Simmie, J.M.; Bourque, G.
2008-04-15
The oxidation of propane has been studied in the temperature range 680-970 K at compressed gas pressures of 21, 27, and 37 atm and at varying equivalence ratios of 0.5, 1.0, and 2.0. These data are consistent with other experiments presented in the literature for alkane fuels in that, when ignition delay times are plotted as a function of temperature, a characteristic negative coefficient behavior is observed. In addition, these data were simulated using a detailed chemical kinetic model. It was found that qualitatively the model correctly simulated the effect of change in equivalence ratio and pressure, predicting that fuel-rich, high-pressure mixtures ignite fastest, while fuel-lean, low-pressure mixtures ignite slowest. Moreover, reactivity as a function of temperature is well captured, with the model predicting negative temperature coefficient behavior similar to the experiments. Quantitatively the model is faster than experiment for all mixtures at the lowest temperatures (650-750 K) and is also faster than experiment throughout the entire temperature range for fuel-lean mixtures. (author)
Kaplan, D.I.; Seme, R.J.
1995-03-01
Burial of vitrified low-level waste (LLW) in the vadose zone of the Hanford Site is being considered as a long-term disposal option. Regulations dealing with LLW disposal require that performance assessment (PA) analyses be conducted. Preliminary modeling efforts for the Hanford Site LLW PA were conducted to evaluate the potential health risk of a number of radionuclides, including Ac, Am, C, Ce, Cm, Co, Cs, Eu, 1, Nb, Ni, Np, Pa, Pb, Pu, Ra, Ru, Se, Sn, Sr, Tc, Th, U, and Zr (Piepho et al. 1994). The radionuclides, {sup 129}I, {sup 237}Np, {sup 79}Se, {sup 99}Tc, and {sup 234,235,238}U, were identified as posing the greatest potential health hazard. It was also determined that the outcome of these simulations were very sensitive to the parameter describing the extent to which radionuclides sorbed to the subsurface matrix, described as a distribution coefficient (K{sub d}). The distribution coefficient is a ratio of the radionuclide concentration associated with the solid phase to that in the liquid phase. The literature-derived K{sub d} values used in these simulations were conservative, i.e., lowest values within the range of reasonable values used to provide an estimate of the maximum health threat. Thus, these preliminary modeling results reflect a conservative estimate rather than a best estimate of what is likely to occur. The potential problem with providing only a conservative estimate is that it may mislead us into directing resources to resolve nonexisting problems.
Rate coefficients for reaction of OH with acetone between 202 and 395 K
Wollenhaupt, M.; Carl, S.A.; Horowitz, A.; Crowley, J.N.
2000-03-30
The kinetics of the title reaction were investigated between 202 and 395 K and at 20, 50, and 100 Torr of Ar or N{sub 2} bath gas using pulsed laser photolysis (PLP) generation of OH combined with both resonance fluorescence (RF) and laser-induced fluorescence (LIF) detection. OH was generated either by the sequential 439 nm, two-photon dissociation of NO{sub 2} in the presence of H{sub 2}, or by HONO photolysis at 351 nm. The accuracy of the rate constants obtained was enhanced by optical absorption measurements of acetone concentrations both before and after the photolysis reactor. The temperature dependence is not describe by a simple Arrhenius expression but by k{sub 1} (202--395 K) = 8.8 x 10{sup {minus}12} exp({minus}1,320/T) + 1.7 x 10{sup {minus}14} exp(423/T) cm{sup 3} s{sup {minus}1}, indicating that a simple H atom abstraction may not be the only reaction mechanism. The estimated total error (95% confidence) associated wit the rate coefficient derived from this expression is estimated as 5% and is independent of temperature. The curvature in the Arrhenius plot results in a significantly larger rate coefficient at low temperatures than obtained by extrapolation of the previous measurement and implies greater significance for the reaction with OH as a sink for acetone in the upper troposphere than presently assumed.
Keeney, J.A.; Bryson, J.W.
1995-12-31
A problem of particular interest in pressure vessel technology is the calculation of accurate stress-intensity factors for semielliptical surface cracks in cylinders. Computing costs for direct solution techniques can be prohibitive when applied to three-dimensional (3-D) geometries with time-varying boundary conditions such as those associated with pressurized thermal shock. An alternative superposition technique requires the calculation of a set of influence coefficients for a given 3-D crack model that can be superimposed to obtain mode-I stress-intensity factors. This paper presents stress-intensity-factor influence coefficients (SIFICs) for axially and circumferentially oriented finite-length semielliptical inner-surface flaws with aspect ratios (total crack length (2c) to crack depth (a)) of 2, 6, and 10 for clad cylinders having an internal radius to wall thickness (t) ratio of 10. SIFICs are computed for flaw depths in the range of 0.01 {le} a/t {le} 0.5 and two cladding thicknesses. The incorporate of this SIFIC data base in fracture mechanics codes will facilitate the generation of fracture mechanics solutions for a wide range of flaw geometries as may be required in structural integrity assessments of pressurized-water and boiling-water reactors.
Assessment of wear coefficients of nuclear zirconium claddings without and with pre-oxidation
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Qu, Jun; Cooley, Kevin M.; Shaw, Austin H.; Lu, Roger Y.; Blau, Peter J.
2016-03-16
In the cores of pressurized water nuclear reactors, water-flow induced vibration is known to cause claddings on the fuel rods to rub against their supporting grids. Such grid-to-rod-fretting (GTRF) may lead to fretting wear-through and the leakage of radioactive species. The surfaces of actual zirconium alloy claddings in a reactor are inevitably oxidized in the high-temperature pressurized water, and some claddings are even pre-oxidized. As a result, the wear process of the surface oxide film is expected to be quite different from the zirconium alloy substrate. In this paper, we attempt to measure the wear coefficients of zirconium claddings withoutmore » and with pre-oxidation rubbing against grid samples using a bench-scale fretting tribometer. Results suggest that the volumetric wear coefficient of the pre-oxidized cladding is 50 to 200 times lower than that of the untreated cladding. In terms of the linear rate of wear depth, the pre-oxidized alloy wears about 15 times more slowly than the untreated cladding. Finally, fitted with the experimentally-determined wear rates, a stage-wise GTRF engineering wear model demonstrates good agreement with in-reactor experience in predicting the trend of cladding lives.« less
Device and method for measuring the coefficient of performance of a heat pump
Brantley, Vanston R.; Miller, Donald R.
1984-01-01
A method and instrument is provided which allows quick and accurate measurement of the coefficient of performance of an installed electrically powered heat pump including auxiliary resistance heaters. Temperature sensitive resistors are placed in the return and supply air ducts to measure the temperature increase of the air across the refrigerant and resistive heating elements of the system. The voltages across the resistors which are directly proportional to the respective duct temperatures are applied to the inputs of a differential amplifier so that its output voltage is proportional to the temperature difference across the unit. A voltage-to-frequency converter connected to the output of the differential amplifier converts the voltage signal to a proportional frequency signal. A digital watt meter is used to measure the power to the unit and produces a signal having a frequency proportional to the input power. A digital logic circuit ratios the temperature difference signal and the electric power input signal in a unique manner to produce a single number which is the coefficient of performance of the unit over the test interval. The digital logic and an in-situ calibration procedure enables the instrument to make these measurements in such a way that the ratio of heat flow/power input is obtained without computations. No specialized knowledge of thermodynamics or electronics is required to operate the instrument.
Device and method for measuring the coefficient of performance of a heat pump
Brantley, V.R.; Miller, D.R.
1982-05-18
A method and instrument is provided which allows quick and accurate measurement of the coefficient of performance of an installed electrically powered heat pump including auxiliary resistane heaters. Temperature-sensitive resistors are placed in the return and supply air ducts to measure the temperature increase of the air across the refrigerant and resistive-heating elements of the system. The voltages across the resistors which are directly proportional to the respective duct tempertures are applied to the inputs of a differential amplifier so that its output voltage is proportional to the temperature difference across the unit. A voltage-to-frequency converter connected to the output of the differential amplifier converts the voltage signal to a proportional-frequency signal. A digital watt meter is used to measure the power to the unit and produces a signal having a frequency proportional to the input power. A digital logic circuit ratios the temperature difference signal and the electric power input signal in a unique manner to produce a single number which is the coefficient of performance of the unit over the test interval. The digital logic and an in-situ calibration procedure enables the instrument to make these measurements in such a way that the ratio of heat flow/power input is obtained without computations. No specialized knowledge of thermodynamics or electrons is required to operate the instrument.
Electron distribution function and recombination coefficient in ultracold plasma in a magnetic field
Bobrov, A. A.; Bronin, S. Ya.; Zelener, B. B.; Zelener, B. V.; Manykin, E. A.; Khikhlukha, D. R.
2013-07-15
The electron distribution function and diffusion coefficient in energy space have been calculated for the first time for a weakly coupled ultracold plasma in a magnetic field in the range of magnetic fields B = 100-50000 G for various temperatures. The dependence of these characteristics on the magnetic field is analyzed and the distribution function is shown to depend on the electron energy shift in a magnetic field. The position of the 'bottleneck' of the distribution function has been found to be shifted toward negative energies with increasing magnetic field. The electron velocity autocorrelators as a function of the magnetic field have been calculated; their behavior suggests that the frequency of collisions between charged particles decreases significantly with increasing magnetic field. The collisional recombination coefficient {alpha}{sub B} has been calculated in the diffusion approximation for a weakly coupled ultracold plasma in a magnetic field. An increase in magnetic field is shown to lead to a decrease in {alpha}{sub B} and this decrease can be several orders of magnitude.
Bellomo, Bruno; De Pasquale, Antonella; Gualdi, Giulia; Marzolino, Ugo
2010-12-15
We propose a procedure to fully reconstruct the time-dependent coefficients of convolutionless non-Markovian dissipative generators via a finite number of experimental measurements. By combining a tomography-based approach with a proper data sampling, our proposal allows to relate the time-dependent coefficients governing the dissipative evolution of a quantum system to experimentally accessible quantities. The proposed scheme not only provides a way to retrieve the full information about potentially unknown dissipative coefficients, but also, most valuably, can be employed as a reliable consistency test for the approximations involved in the theoretical derivation of a given non-Markovian convolutionless master equation.
Energy Science and Technology Software Center (OSTI)
1985-10-10
MARCOPOLO calculates the radial and axial diffusion coefficients in one-group and multi-group theory for a cylinderized cell (Wigner-Seitz theory) with several concentric zones according to the isotropic shock or linear anisotropic shock hypotheses.
Methods And System Suppressing Clutter In A Gain-Block, Radar-Responsive Tag System
Ormesher, Richard C.; Axline, Robert M.
2006-04-18
Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radar systems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radar system.
MAR,ALAN; LOUBRIEL,GUILLERMO M.; ZUTAVERN,FRED J.; O'MALLEY,MARTIN W.; HELGESON,WESLEY D.; BROWN,DARWIN JAMES; HJALMARSON,HAROLD P.; BACA,ALBERT G.; THORNTON,R.L.; DONALDSON,R.D.
1999-12-17
The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to over 100 million pulses. This was achieved by improving the ohmic contacts through the incorporation of a doped layer that is very effective in the suppression of filament formation, alleviating current crowding. Damage-free operation is now possible with virtually infinite expected lifetime at much higher current levels than before. The inherent damage-free current capacity of the bulk GaAs itself depends on the thickness of the doped layers and is at least 100A for a dopant diffusion depth of 4pm. The contact metal has a different damage mechanism and the threshold for damage ({approx}40A) is not further improved beyond a dopant diffusion depth of about 2{micro}m. In a diffusion-doped contact switch, the switching performance is not degraded when contact metal erosion occurs, unlike a switch with conventional contacts. This paper will compare thermal diffusion and epitaxial growth as approaches to doping the contacts. These techniques will be contrasted in terms of the fabrication issues and device characteristics.
Gain and tuning characteristics of mid-infrared InSb quantum dot diode lasers
Lu, Q.; Zhuang, Q.; Hayton, J.; Yin, M.; Krier, A.
2014-07-21
There have been relatively few reports of lasing from InSb quantum dots (QDs). In this work, type II InSb/InAs QD laser diodes emitting in the mid-infrared at 3.1??m have been demonstrated and characterized. The gain was determined to be 2.9?cm{sup ?1} per QD layer, and the waveguide loss was ?15?cm{sup ?1} at 4?K. Spontaneous emission measurements below threshold revealed a blue shift of the peak wavelength with increasing current, indicating filling of ground state heavy hole levels in the QDs. The characteristic temperature, T{sub 0}?=?101?K below 50?K, but decreased to 48?K at higher temperatures. The emission wavelength of these lasers showed first a blue shift followed by a red shift with increasing temperature. A hybrid structure was used to fabricate the laser by combining a liquid phase epitaxy grown p-InAs{sub 0.61}Sb{sub 0.13}P{sub 0.26} lower cladding layer and an upper n{sup +} InAs plasmon cladding layer which resulted in a maximum operating temperature (T{sub max}) of 120?K in pulsed mode, which is the highest reported to date.
Chow, W.W.; Jones, E.D.; Modine, N.A.; Allerman, A.A.; Kurtz, S.R.
1999-08-04
The optical gain spectra for compressive-strained and lattice-matched GaInNAs/GaAs quantum wells are computed using a microscopic laser theory. From these spectra, the peak gain and carrier radiative decay rate as functions of carrier density are determined. These dependences allow the study of lasing threshold current density for different GAInNAs/GaAs laser structures.
Record Seebeck coefficient and extremely low thermal conductivity in nanostructured SnSe
Serrano-Sánchez, F.; Gharsallah, M.; Nemes, N. M.; Mompean, F. J.; Martínez, J. L.; Alonso, J. A.
2015-02-23
SnSe has been prepared by arc-melting, as mechanically robust pellets, consisting of highly oriented polycrystals. This material has been characterized by neutron powder diffraction (NPD), scanning electron microscopy, and transport measurements. A microscopic analysis from NPD data demonstrates a quite perfect stoichiometry SnSe{sub 0.98(2)} and a fair amount of anharmonicity of the chemical bonds. The Seebeck coefficient reaches a record maximum value of 668 μV K{sup −1} at 380 K; simultaneously, this highly oriented sample exhibits an extremely low thermal conductivity lower than 0.1 W m{sup −1} K{sup −1} around room temperature, which are two of the main ingredients of good thermoelectric materials. These excellent features exceed the reported values for this semiconducting compound in single crystalline form in the moderate-temperatures region and highlight its possibilities as a potential thermoelectric material.
Shivaramu; Amutha, R.; Ramprasath, V.
1999-05-01
Effective atomic numbers for total gamma-ray interaction with some selected thermoluminescent dosimetric compounds such as barium acetate, barium sulfate, calcium carbonate, calcium sulfate, calcium sulfate dihydrate, cadmium sulfate (anhydrous), cadmium sulfate, strontium sulfate, and lithium fluoride have been calculated in the 1-keV to 20-MeV energy region. Experimental mass attenuation coefficients and effective atomic numbers for these compounds at selected photon energies of 26.3, 33.2, 59.54, and 661.6 keV have been obtained from good geometry transmission measurements and compared with theoretical values. The effect of absorption edge on effective atomic numbers and its variation with energy, and nonvalidity of the Bragg`s mixture rule at incident photon energies closer to the absorption edges of constituent elements of compounds are discussed.
On-Line Measurement of Lubricant Film Thickness Using Ultrasonic Reflection Coefficients
Drinkwater, B.W.; Dwyer-Joyce, R.S.; Harper, P.
2004-02-26
The ultrasonic reflectivity of a lubricant layer between two solid bodies depends on the ultrasonic frequency, the acoustic properties of the liquid and solid, and the layer thickness. In this paper, ultrasonic reflectivity measurements are used as a method for determining the thickness of lubricating films in bearing systems. An ultrasonic transducer is positioned on the outside of a bearing shell such that the wave is focused on the lubricant film layer. For a particular lubricant film the reflected pulse is processed to give a reflection coefficient spectrum. The lubricant film thickness is then obtained from either the layer stiffness or the resonant frequency. The method has been validated using static fluid wedges and the elastohydrodynamic film formed between a ball sliding on a flat. Film thickness values in the range 50-500 nm were recorded which agreed well with theoretical film formation predictions.
Wedge sampling for computing clustering coefficients and triangle counts on large graphs
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Seshadhri, C.; Pinar, Ali; Kolda, Tamara G.
2014-05-08
Graphs are used to model interactions in a variety of contexts, and there is a growing need to quickly assess the structure of such graphs. Some of the most useful graph metrics are based on triangles, such as those measuring social cohesion. Despite the importance of these triadic measures, algorithms to compute them can be extremely expensive. We discuss the method of wedge sampling. This versatile technique allows for the fast and accurate approximation of various types of clustering coefficients and triangle counts. Furthermore, these techniques are extensible to counting directed triangles in digraphs. Our methods come with provable andmore » practical time-approximation tradeoffs for all computations. We provide extensive results that show our methods are orders of magnitude faster than the state of the art, while providing nearly the accuracy of full enumeration.« less
Dobos, A. P.
2012-05-01
This paper describes an improved algorithm for calculating the six parameters required by the California Energy Commission (CEC) photovoltaic (PV) Calculator module model. Rebate applications in California require results from the CEC PV model, and thus depend on an up-to-date database of module characteristics. Currently, adding new modules to the database requires calculating operational coefficients using a general purpose equation solver - a cumbersome process for the 300+ modules added on average every month. The combination of empirical regressions and heuristic methods presented herein achieve automated convergence for 99.87% of the 5487 modules in the CEC database and greatly enhance the accuracy and efficiency by which new modules can be characterized and approved for use. The added robustness also permits general purpose use of the CEC/6 parameter module model by modelers and system analysts when standard module specifications are known, even if the module does not exist in a preprocessed database.
Electrical conductivity, Seebeck coefficient, and defect structure of Ca-doped YCrO sub 3
Carini, G.F. II.
1990-01-01
High temperature electrical conductivity, Seebeck coefficient, and thermogravimetric measurements were made as a function of oxygen activity to investigate the electrical transport behavior and defect structure of Ca-doped YCrO{sub 3}. Defect models were developed to correlate the electrical conductivity and thermogravimetric data by relating the concentration of charge carriers to the acceptor dopant and oxygen vacancy concentrations. These relations were found to adequately explain the experimental data. Thermodynamic properties were calculated which were consistent with the model. Calculations of the carrier concentrations, the activation energies, and the mobilities were also performed. The analysis of the electrical conductivity, Seebeck and mobility data suggested that the conduction process in Ca-doped YCrO{sub 3} occurs via the small polaron hopping mechanism. Kroger-Vink diagrams showing the regions of stability with respect to oxygen activity and temperature were constructed.
Utilization of sensitivity coefficients to guide the design of a thermal battery
Blackwell, B.F.; Dowding, K.J.; Cochran, R.J.; Dobranich, D.
1998-08-01
Equations are presented to describe the sensitivity of the temperature field in a heat-conducting body to changes in the volumetric heat source and volumetric heat capacity. These sensitivity equations, along with others not presented, are applied to a thermal battery problem to compute the sensitivity of the temperature field to 19 model input parameters. Sensitivity coefficients, along with assumed standard deviation in these parameters, are used to estimate the uncertainty in the temperature prediction. From the 19 parameters investigated, the battery cell heat source and volumetric heat capacity were clearly identified as being the major contributors to the overall uncertainty in the temperature predictions. The operational life of the thermal battery was shown to be very sensitive to uncertainty in these parameters.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ihlefeld, Jon F.; Brown-Shaklee, Harlan James; Sharma, Peter Anand
2015-04-28
The transport properties of ceramic materials strongly depend on oxygen activity, which is tuned by changing the partial oxygen pressure (pO2) prior to and during measurement. Within, we describe an instrument for highly stable measurements of Seebeck coefficient and electrical resistivity at temperatures up to 1300 K with controlled oxygen partial pressure. An all platinum construction is used to avoid potential materials instabilities that can cause measurement drift. Two independent heaters are employed to establish a small temperature gradient for Seebeck measurements, while keeping the average temperature constant and avoiding errors associated with pO2-induced drifts in thermocouple readings. Oxygen equilibriummore » is monitored using both an O2 sensor and the transient behavior of the resistance as a proxy. A pO2 range of 10-25–100 atm can be established with appropriate gas mixtures. Seebeck measurements were calibrated against a high purity platinum wire, Pt/Pt–Rh thermocouple wire, and a Bi2Te3 Seebeck coefficient Standard Reference Material. To demonstrate the utility of this instrument for oxide materials we present measurements as a function of pO2 on a 1 % Nb-doped SrTiO3 single crystal, and show systematic changes in properties consistent with oxygen vacancy defect chemistry. Thus, an approximately 11% increase in power factor over a pO2 range of 10-19–10-8 atm at 973 K for the donor-doped single crystals is observed.« less
Ceramic materials with low thermal conductivity and low coefficients of thermal expansion
Brown, J.; Hirschfeld, D.; Liu, D.M.; Yang, Y.; Li, T.; Swanson, R.E.; Van Aken, S.; Kim, J.M.
1992-04-07
Compositions, having the general formula (Ca[sub x]Mg[sub 1[minus]x])Zr[sub 4](PO[sub 4])[sub 6] where x is between 0.5 and 0.99, are produced by solid state and sol-gel processes. In a preferred embodiment, when x is between 0.5 and 0.8, the MgCZP materials have near-zero coefficients of thermal expansion. The MgCZPs of the present invention also show unusually low thermal conductivities, and are stable at high temperatures. Macrostructures formed from MgCZP are useful in a wide variety of high-temperature applications. In a preferred process, calcium, magnesium, and zirconium nitrate solutions have their pH adjusted to between 7 and 9 either before or after the addition of ammonium dihydrogen phosphate. After dehydration to a gel, and calcination at temperatures in excess of 850 C for approximately 16 hours, single phase crystalline MgCZP powders with particle sizes ranging from approximately 20 nm to 50 nm result. The MgCZP powders are then sintered at temperatures ranging from 1200 C to 1350 C to form solid macrostructures with near-zero bulk coefficients of thermal expansion and low thermal conductivities. Porous macrostructures of the MgCZP powders of the present invention are also formed by combination with a polymeric powder and a binding agent, and sintering at high temperatures. The porosity of the resulting macrostructures can be adjusted by varying the particle size of the polymeric powder used. 7 figs.
Ceramic materials with low thermal conductivity and low coefficients of thermal expansion
Brown, Jesse; Hirschfeld, Deidre; Liu, Dean-Mo; Yang, Yaping; Li, Tingkai; Swanson, Robert E.; Van Aken, Steven; Kim, Jin-Min
1992-01-01
Compositions having the general formula (Ca.sub.x Mg.sub.1-x)Zr.sub.4 (PO.sub.4).sub.6 where x is between 0.5 and 0.99 are produced by solid state and sol-gel processes. In a preferred embodiment, when x is between 0.5 and 0.8, the MgCZP materials have near-zero coefficients of thermal expansion. The MgCZPs of the present invention also show unusually low thermal conductivities, and are stable at high temperatures. Macrostructures formed from MgCZP are useful in a wide variety of high-temperature applications. In a preferred process, calcium, magnesium, and zirconium nitrate solutions have their pH adjusted to between 7 and 9 either before or after the addition of ammonium dihydrogen phosphate. After dehydration to a gel, and calcination at temperatures in excess of 850.degree. C. for approximately 16 hours, single phase crystalline MgCZP powders with particle sizes ranging from approximately 20 nm to 50 nm result. The MgCZP powders are then sintered at temperatures ranging from 1200.degree. C. to 1350.degree. C. to form solid macrostructures with near-zero bulk coefficients of thermal expansion and low thermal conductivities. Porous macrostructures of the MgCZP powders of the present invention are also formed by combination with a polymeric powder and a binding agent, and sintering at high temperatures. The porosity of the resulting macrostructures can be adjusted by varying the particle size of the polymeric powder used.
Ihlefeld, Jon F.; Brown-Shaklee, Harlan James; Sharma, Peter Anand
2015-04-28
The transport properties of ceramic materials strongly depend on oxygen activity, which is tuned by changing the partial oxygen pressure (pO_{2}) prior to and during measurement. Within, we describe an instrument for highly stable measurements of Seebeck coefficient and electrical resistivity at temperatures up to 1300 K with controlled oxygen partial pressure. An all platinum construction is used to avoid potential materials instabilities that can cause measurement drift. Two independent heaters are employed to establish a small temperature gradient for Seebeck measurements, while keeping the average temperature constant and avoiding errors associated with pO_{2}-induced drifts in thermocouple readings. Oxygen equilibrium is monitored using both an O_{2} sensor and the transient behavior of the resistance as a proxy. A pO_{2} range of 10^{-25}–10^{0} atm can be established with appropriate gas mixtures. Seebeck measurements were calibrated against a high purity platinum wire, Pt/Pt–Rh thermocouple wire, and a Bi_{2}Te3 Seebeck coefficient Standard Reference Material. To demonstrate the utility of this instrument for oxide materials we present measurements as a function of pO_{2} on a 1 % Nb-doped SrTiO_{3} single crystal, and show systematic changes in properties consistent with oxygen vacancy defect chemistry. Thus, an approximately 11% increase in power factor over a pO_{2} range of 10^{-19}–10^{-8} atm at 973 K for the donor-doped single crystals is observed.