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1

Advancing Reactive Tracer Methods for Measuring Thermal Evolution...  

Open Energy Info (EERE)

History Facebook icon Twitter icon Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Geothermal Lab Call Project...

2

Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2-  

Open Energy Info (EERE)

Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Geothermal Lab Call Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Project Type / Topic 1 Laboratory Call for Submission of Applications for Research, Development and Analysis of Geothermal Technologies Project Type / Topic 2 Tracers and Tracer Interpretation Project Description The concepts and theory behind the use of heat-sensitive tracers to study the thermal evolution of geothermal reservoirs was developed in the late 1980's under the Hot Dry Rock Project. Those studies described-conceptually and mathematically-the application of reactive tracers to tracking thermal fronts and to reservoir sizing. Later mathematical treatments focused on application of a single reactive tracer test to recover the temperature profile of a single streamtube. Previous tracer work has mainly focused on identifying conservative tracers. In these studies, chemicals that degraded at reservoir temperatures were discarded. Benzoic acids and dicarboxylic acids, which were found by Adams to degrade, may be useful as reactive tracers. Organic esters and amide tracers that undergo hydrolysis have been investigated and their use as reactive tracers appears feasible over a temperature range of 100ºC to 275ºC. However their reaction rates are pH dependent and sorption reactions have not been evaluated. While reactive tracer parameters have been measured in the lab, reactive tracers have not been extensively tested in the field. Thus, while reactive tracers appear to be a promising means of monitoring the thermal evolution of a geothermal reservoir, the concept has yet to be tested at the scale necessary for successful implementation, and tools for analyzing results of such tracer tests under the non-ideal conditions of an actual geothermal system have yet to be developed.

3

Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report  

DOE Green Energy (OSTI)

The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat from the subsurface or to maintain pressures within the reservoir (e.g., Rose et al., 2001). As these injected fluids move along fractures, they acquire heat from the rock matrix and remove it from the reservoir as they are extracted to the surface. A consequence of such injection is the migration of a cold-fluid front through the reservoir (Figure 1) that could eventually reach the production well and result in the lowering of the temperature of the produced fluids (thermal breakthrough). Efficient operation of an EGS as well as conventional geothermal systems involving cold-fluid injection requires accurate and timely information about thermal depletion of the reservoir in response to operation. In particular, accurate predictions of the time to thermal breakthrough and subsequent rate of thermal drawdown are necessary for reservoir management, design of fracture stimulation and well drilling programs, and forecasting of economic return. A potential method for estimating migration of a cold front between an injection well and a production well is through application of reactive tracer tests, using chemical whose rate of degradation is dependent on the reservoir temperature between the two wells (e.g., Robinson 1985). With repeated tests, the rate of migration of the thermal front can be determined, and the time to thermal breakthrough calculated. While the basic theory behind the concept of thermal tracers has been understood for some time, effective application of the method has yet to be demonstrated. This report describes results of a study that used several methods to investigate application of reactive tracers to monitoring the thermal evolution of a geothermal reservoir. These methods included (1) mathematical investigation of the sensitivity of known and hypothetical reactive tracers, (2) laboratory testing of novel tracers that would improve method sensitivity, (3) development of a software tool for design and interpretation of reactive tracer tests and (4) field testing of the reactive tracer temperature monitoring concept.

Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; Laurence C. Hull; George D. Redden

2011-07-01T23:59:59.000Z

4

Thermal Convection: Patterns, Evolution and Stability by M. Lappa  

E-Print Network (OSTI)

Review of the book "Thermal Convection: Patterns, Evolution and Stability" by M. Lappa. Invited by the journal Geophysical and Astrophysical Fluid Dynamics.

Simitev, R D

2010-01-01T23:59:59.000Z

5

Thermal conductivity Measurements of Kaolite  

Science Conference Proceedings (OSTI)

Testing was performed to determine the thermal conductivity of Kaolite 1600, which primarily consists of Portland cement and vermiculite. The material was made by Thermal Ceramics for refractory applications. Its combination of light weight, low density, low cost, and noncombustibility made it an attractive alternative to the materials currently used in ES-2 container for radioactive materials. Mechanical properties and energy absorption tests of the Kaolite have been conducted at the Y-12 complex. Heat transfer is also an important factor for the application of the material. The Kaolite samples are porous and trap moisture after extended storage. Thermal conductivity changes as a function of moisture content below 100 C. Thermal conductivity of the Kaolite at high temperatures (up to 700 C) are not available in the literature. There are no standard thermal conductivity values for Kaolite because each sample is somewhat different. Therefore, it is necessary to measure thermal conductivity of each type of Kaolite. Thermal conductivity measurements will help the modeling and calculation of temperatures of the ES-2 containers. This report focuses on the thermal conductivity testing effort at ORNL.

Wang, H

2003-02-21T23:59:59.000Z

6

Damage Evolution in Thermal Barrier Coatings with Thermal Cycling  

Science Conference Proceedings (OSTI)

Abstract Scope, Thermal barrier coatings typically fail on cooling after prolonged thermal cycling by the growth of sub-critical interface separations. Observations...

7

Nanosecond time resolved thermal emission measurements during...  

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

Nanosecond time resolved thermal emission measurements during pulse excimer laser interaction with materials Title Nanosecond time resolved thermal emission measurements during...

8

The West Coast Thermal Trough: Climatology and Synoptic Evolution  

Science Conference Proceedings (OSTI)

Although the West Coast thermal trough (WCTT) is the most important mesoscale feature over the U.S. west coast during the warm season, its initiation, evolution, and structure are not well understood. Originating in the southwest United States, ...

Matthew C. Brewer; Clifford F. Mass; Brian E. Potter

2012-12-01T23:59:59.000Z

9

Quantum mechanical evolution towards thermal equilibrium  

E-Print Network (OSTI)

The circumstances under which a system reaches thermal equilibrium, and how to derive this from basic dynamical laws, has been a major question from the very beginning of thermodynamics and statistical mechanics. Despite considerable progress, it remains an open problem. Motivated by this issue, we address the more general question of equilibration. We prove, with virtually full generality, that reaching equilibrium is a universal property of quantum systems: Almost any subsystem in interaction with a large enough bath will reach an equilibrium state and remain close to it for almost all times. We also prove several general results about other aspects of thermalisation besides equilibration, for example, that the equilibrium state does not depend on the detailed micro-state of the bath.

Noah Linden; Sandu Popescu; Anthony J. Short; Andreas Winter

2008-12-12T23:59:59.000Z

10

Design Evolution Study Thermal Operating Methodology  

Science Conference Proceedings (OSTI)

This study provides results supporting the conclusion that the repository can be operated over a varying range of thermal modes and therefore temperatures. In particular, this work focused on limiting the peak, postclosure waste package surface temperature to less than 85 degrees Celsius, a possible limit due to corrosion considerations. These operating modes were compared by varying the waste package in drift spacing (0.1-2.83 meters), drift pitch (drift spacing centerline to centerline of 40-120 meters), ventilation duration (75-300 years), and ventilation efficiency (50-80%). The resulting graphical representation shows where the constant temperature of the waste package (85 degrees Celsius) lies with respect to drift pitch and waste package spacing. The waste considered in this study is the strict youngest fuel first 5 years old fuel. Using only strict youngest fuel first 5 years old fuel in the waste stream results in an average heat load per waste package of 12.48kW/Pkg. With this high average heat load, it is not possible to achieve a maximum waste package surface temperature of 85 degrees Celsius or less. By aging 63% of the strict youngest fuel first 5 years old fuel for 27 years, it becomes possible to maintain the waste package surface temperature at 85 degrees Celsius or less. The 27 years of aging comes from the fact that the repository could be closed in as little as 50 years. It takes 23 years to emplace the waste and therefore the last fuel received for emplacement is 27 years prior to closures. The strict youngest fuel first 5 years old fuel waste stream with 63% aged for 27 years, results in an average power level of 8.4kW/Pkg. This lower heat load allows the controlled parameters of drift pitch, waste package spacing, aging, and ventilation duration to be varied to achieve the desired results. This study compares the hot strict youngest fuel first 5 years old fuel to the previous waste stream, which has an average of 26-year-old fuel. The 26-year-old fuel waste stream has an average power level of 7.2 kW/Pkg. This comparison illustrated how the parameters important to thermal performance differ for these two assumptions about the waste stream.

T.L. Mitchell

2002-04-29T23:59:59.000Z

11

Infrared Thermography Measurements of Window Thermal Test Specimen...  

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

Infrared Thermography Measurements of Window Thermal Test Specimen: Surface Temperatures Title Infrared Thermography Measurements of Window Thermal Test Specimen: Surface...

12

Thermal evolution of rotating strange stars in color superconductivity phase  

E-Print Network (OSTI)

Under the combination effect of the recommencement heating due to spin-down of strange stars and the heat perseveration due to weak conduct heat of the crust, the Cooper pair breaking and formation(PBF) in color superconduction quark matter arises. We investigated the cooling of the strange stars with a crust in color superconductivity phase including both decomfinement heating and PBF process. We find that deconfinement heating can delay the thermal evolution of strange stars and the PBF process suppresses the early temperature rise of the stars. The cooling strange stars behave within the brightness constraint of young compact objects when the color superconductivity gap is small enough.

X. P. Zheng; X. Zhou; Y. W. Yu

2006-07-04T23:59:59.000Z

13

A THERMAL EVOLUTION MODEL OF CENTAUR 10199 CHARIKLO  

SciTech Connect

Centaur 10199 Chariklo appears to have a varying spectral behavior. While three different spectral studies detect the presence of water ice at the surface, two more recent studies do not detect any absorption bands. In this article, we consider the possibility that Chariklo undergoes cometary activity that could be responsible for the observed spectral variations. We simulate its thermal evolution, finding that crystalline water ice should be present in the object core, and amorphous water ice should be found at the surface. Upon entering the inner solar system, Chariklo might experience some cometary activity due to ice crystallization if the obliquity is high, due to the adjustment of the internal structure to a new thermal equilibrium. No other activity is expected from this source, unless an external source like an impact provides the heat needed. In the case of such an event, we find that dust emitted in a coma is unlikely to be responsible for the observed spectral variations. In contrast, water ice grains in the coma would reproduce this pattern, meaning that the water ice detected after Chariklo's discovery was present in these grains and not on the object surface. Nonetheless, any activity would require an external additional heat source to be triggered, through an outburst, which might favor the spatial variations hypothesis.

Guilbert-Lepoutre, A., E-mail: aguilbert@ucla.edu [Department of Earth and Space Sciences, UCLA, Los Angeles, CA 90095 (United States)

2011-03-15T23:59:59.000Z

14

Predicting Thermal Conductivity Evolution of Polycrystalline Materials Under Irradiation Using Multiscale Approach  

SciTech Connect

A multiscale methodology was developed to predict the evolution of thermal conductivity of polycrystalline fuel under irradiation. In the mesoscale level, phase field model was used to predict the evolution of gas bubble microstructure. Generation of gas atoms and vacancies were taken into consideration. In the macroscopic scale, a statistical continuum mechanics model was applied to predict the anisotropic thermal conductivity evolution during irradiation. Microstructure predicted by phase field model was fed into statistical continuum mechanics model to predict properties and behavior. Influence of irradiation intensity, exposition time and morphology were investigated. This approach provides a deep understanding on microstructure evolution and property prediction from a basic scientific viewpoint.

Li, Dongsheng; Li, Yulan; Hu, Shenyang Y.; Sun, Xin; Khaleel, Mohammad A.

2012-03-01T23:59:59.000Z

15

Measuring the evolution of internet peering agreements  

Science Conference Proceedings (OSTI)

There is much interest in studying the structure and evolution of the Internet at the Autonomous System (AS) level. However, limitations of public data sources in detecting settlement-free peering links meant that prior work focused almost exclusively ... Keywords: autonomous systems, economics, internet topology, peering

Amogh Dhamdhere; Himalatha Cherukuru; Constantine Dovrolis; Kc Claffy

2012-05-01T23:59:59.000Z

16

The impact of magnetic field on the thermal evolution of neutron stars  

E-Print Network (OSTI)

The impact of strong magnetic fields B>10e13 G on the thermal evolution of neutron stars is investigated, including crustal heating by magnetic field decay. For this purpose, we perform 2D cooling simulations with anisotropic thermal conductivity considering all relevant neutrino emission processes for realistic neutron stars. The standard cooling models of neutron stars are called into question by showing that the magnetic field has relevant (and in many cases dominant) effects on the thermal evolution. The presence of the magnetic field significantly affects the thermal surface distribution and the cooling history of these objects during both, the early neutrino cooling era and the late photon cooling era. The minimal cooling scenario is thus more complex than generally assumed. A consistent magneto-thermal evolution of magnetized neutron stars is needed to explain the observations.

Deborah N. Aguilera; Jos A. Pons; Juan A. Miralles

2007-12-09T23:59:59.000Z

17

The impact of magnetic field on the thermal evolution of neutron stars  

E-Print Network (OSTI)

The impact of strong magnetic fields B>10e13 G on the thermal evolution of neutron stars is investigated, including crustal heating by magnetic field decay. For this purpose, we perform 2D cooling simulations with anisotropic thermal conductivity considering all relevant neutrino emission processes for realistic neutron stars. The standard cooling models of neutron stars are called into question by showing that the magnetic field has relevant (and in many cases dominant) effects on the thermal evolution. The presence of the magnetic field significantly affects the thermal surface distribution and the cooling history of these objects during both, the early neutrino cooling era and the late photon cooling era. The minimal cooling scenario is thus more complex than generally assumed. A consistent magneto-thermal evolution of magnetized neutron stars is needed to explain the observations.

Aguilera, Deborah N; Miralles, Juan A

2007-01-01T23:59:59.000Z

18

Purity of Gaussian states: Measurement schemes and time evolution in noisy channels  

SciTech Connect

We present a systematic study of the purity for Gaussian states of single-mode continuous variable systems. We prove the connection of purity to observable quantities for these states, and show that the joint measurement of two conjugate quadratures is necessary and sufficient to determine the purity at any time. The statistical reliability and the range of applicability of the proposed measurement scheme are tested by means of Monte Carlo simulated experiments. We then consider the dynamics of purity in noisy channels. We derive an evolution equation for the purity of general Gaussian states both in thermal and in squeezed thermal baths. We show that purity is maximized at any given time for an initial coherent state evolving in a thermal bath, or for an initial squeezed state evolving in a squeezed thermal bath whose asymptotic squeezing is orthogonal to that of the input state.

Paris, Matteo G.A. [Quantum Optics and Information Group, INFM UdR di Pavia, I-27100 Pavia (Italy); Illuminati, Fabrizio; Serafini, Alessio; De Siena, Silvio [Dipartimento di Fisica 'E. R. Caianiello', Universita di Salerno, INFM UdR Salerno, INFN Sez. Napoli, Grupo Collegato Salerno, Via S. Allende, 84081 Baronissi, SA (Italy)

2003-07-01T23:59:59.000Z

19

Measurement of Thermal Diffusity and Flow Resistance for TCAP Materials  

DOE Green Energy (OSTI)

SRS uses the Thermal Cycling Absorption Process (TCAP) to separate isotopes of hydrogen. The frequency of thermal cycles is a limit of the productivity of the process and that frequency is largely determined by the thermal diffusivity of the absorbent material. For a given tube diameter, a larger thermal diffusivity decreases the time required for each cycle. In 1998, the Engineering Development Laboratory measured thermal diffusivity and thermal conductivity for three TCAP materials in helium.

STEIMKE, JOHN

2004-11-11T23:59:59.000Z

20

Thermal evolution behavior of carbides and {gamma} Prime precipitates in FGH96 superalloy powder  

SciTech Connect

The characteristics of rapidly solidified FGH96 superalloy powder and the thermal evolution behavior of carbides and {gamma} Prime precipitates within powder particles were investigated. It was observed that the reduction of powder size and the increase of cooling rate had transformed the solidification morphologies of atomized powder from dendrite in major to cellular structure. The secondary dendritic spacing was measured to be 1.02-2.55 {mu}m and the corresponding cooling rates were estimated to be in the range of 1.4 Multiplication-Sign 10{sup 4}-4.7 Multiplication-Sign 10{sup 5} K{center_dot}s{sup -1}. An increase in the annealing temperature had rendered the phase transformation of carbides evolving from non-equilibrium MC Prime carbides to intermediate transition stage of M{sub 23}C{sub 6} carbides, and finally to thermodynamically stable MC carbides. The superfine {gamma} Prime precipitates were formed at the dendritic boundaries of rapidly solidified superalloy powder. The coalescence, growth, and homogenization of {gamma}' precipitates occurred with increasing annealing temperature. With decreasing cooling rate from 650 Degree-Sign C{center_dot}K{sup -1} to 5 Degree-Sign C{center_dot}K{sup -1}, the morphological development of {gamma} Prime precipitates had been shown to proceed from spheroidal to cuboidal and finally to solid state dendrites. Meanwhile, a shift had been observed from dendritic morphology to recrystallized structure between 900 Degree-Sign C and 1050 Degree-Sign C. Moreover, accelerated evolution of carbides and {gamma}' precipitates had been facilitated by the formation of new grain boundaries which provide fast diffusion path for atomic elements. - Highlights: Black-Right-Pointing-Pointer Microstructural characteristic of FGH96 superalloy powder was investigated. Black-Right-Pointing-Pointer The relation between microstructure, particle size, and cooling rate was studied. Black-Right-Pointing-Pointer Thermal evolution behavior of {gamma} Prime and carbides in loose FGH96 powder was studied.

Zhang Lin, E-mail: zhanglincsu@163.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Liu Hengsan, E-mail: lhsj63@sohu.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); He Xinbo, E-mail: xb_he@163.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Rafi-ud-din, E-mail: rafiuddi@gmail.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Qu Xuanhui, E-mail: quxh@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Qin Mingli, E-mail: mlqin75@hotmail.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Li Zhou, E-mail: zhouli621@126.com [National Key Lab of High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing, 100095 (China); Zhang Guoqing, E-mail: g.zhang@126.com [National Key Lab of High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing, 100095 (China)

2012-05-15T23:59:59.000Z

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


21

Major transitions in evolution linked to thermal gradients above hydrothermal vents  

E-Print Network (OSTI)

The emergence of the main divisions of today's life: (1) unicellular prokaryotes, (2) unicellular eukaryotes, (3) multicellular eukaryotes, and (4) metazoans, are examples of the--still unexplained--major transitions in evolution. Regarding the origin of life, I have proposed that primordial life functioned as heat engine (thermosynthesis) while thermally cycled in convecting volcanic hot springs. Here I argue for a role of thermal gradients above submarine hydrothermal vents (SHV) in several major transitions. The last decade has witnessed the emergence of phononics, a novel discipline in physics based on controlled heat transport in thermal gradients. It builds thermal analogs to electronic devices: the thermal diode, the thermal transistor, the thermal switch, the thermal amplifier, the thermal memory--the thermal computer has been proposed. Encouraged by (1) the many similarities between microtubules (MT) and carbon nanotubes, which have a very high thermal conductivity, and (2) the recent discovery of a silk protein which also has a very high thermal conductivity, I combine and extend the mentioned ideas, and propose the general conjecture that several major transitions of evolution were effected by thermal processes, with four additional partial conjectures: (1) The first organisms used heat engines during thermosynthesis in convection cells; (2) The first eukaryotic cells used MT during thermosynthesis in the thermal gradient above SHV; (3) The first metazoans used transport of water or in water during thermosynthesis above SHV under an ice-covered ocean during the Gaskiers Snowball Earth; and (4) The first mammalian brain used a thermal machinery based on thermal gradients in or across the cortex. When experimentally proven these conjectures, which are testable by the methods of synthetic biology, would significantly enhance our understanding of life.

Anthonie W. J. Muller

2012-12-03T23:59:59.000Z

22

3 omega method for specific heat and thermal conductivity measurements  

E-Print Network (OSTI)

We present a 3 omega method for simultaneously measuring the specific heat and thermal conductivity of a rod- or filament-like specimen using a way similar to a four-probe resistance measurement. The specimen in this method needs to be electrically conductive and with a temperature-dependent resistance, for acting both as a heater to create a temperature fluctuation and as a sensor to measure its thermal response. With this method we have successfully measured the specific heat and thermal conductivity of platinum wire specimens at cryogenic temperatures, and measured those thermal quantities of tiny carbon nanotube bundles some of which are only 10^-9 g in mass.

L. Lu; W. Yi; D. L. Zhang

2002-02-06T23:59:59.000Z

23

An Empirical Model of UO2 Thermal Conductivity Based on Laser Flash Measurements of Thermal Diffusivity  

Science Conference Proceedings (OSTI)

Thermal conductivity of irradiated fuel materials, which can be derived from measured thermal diffusivity (TD), is a key consideration in thermal performance and design of a fuel rod. However, without interpretation, the measured TD data cannot be used directly to calculate fuel temperatures during irradiation. This report provides such interpretation and presents an empirical model for the degradation of UO2 thermal conductivity with burn-up.

1998-10-07T23:59:59.000Z

24

Thermal Conductivity Measurements of Thermoelectric Films  

Science Conference Proceedings (OSTI)

... which allow solid-state conversion of thermal to electrical energy, have a ... and exhaust system, which can run either an electric motor or accessories ...

2013-03-15T23:59:59.000Z

25

Stochastic Measures and Modular Evolution in Non-equilibrium Thermodynamics  

E-Print Network (OSTI)

We present an application of the theory of stochastic processes to model and categorize non-equilibrium physical phenomena. The concepts of uniformly continuous probability measures and modular evolution lead to a systematic hierarchical structure for (physical) correlation functions and non-equilibrium thermodynamical potentials. It is proposed that macroscopic evolution equations (such as dynamic correlation functions) may be obtained from a non-equilibrium thermodynamical description, by using the fact that extended thermodynamical potentials belong to a certain class of statistical systems whose probability distribution functions are defined by a stationary measure; although a measure which is, in general, different from the equilibrium Gibbs measure. These probability measures obey a certain hierarchy on its stochastic evolution towards the most probable (stationary) measure. This in turns defines a convergence sequence. We propose a formalism which considers the mesoscopic stage (typical of non-local dissipative processes such as the ones described by extended irreversible thermodynamics) as being governed by stochastic dynamics due to the effect of non-equilibrium fluctuations. Some applications of the formalism are described.

Enrique Hernandez-Lemus; Jesus K. Estrada-Gil

2009-08-15T23:59:59.000Z

26

Measuring Thermal Conductivity of Powder Insulation at Cryogenic Temperatures.  

E-Print Network (OSTI)

?? A device to measure bulk effective thermal conductivity of powder insulation at cryogenic temperatures has been designed and tested. The design consists of two (more)

Barrios, Matthew Nicklas

2006-01-01T23:59:59.000Z

27

Measurements of the Thermal Neutron Scattering Kernel  

E-Print Network (OSTI)

world's most powerful neutron source, the $1.4 billion Spallation Neutron Source At 1.4MW, SNS produces. SNS will feature 24 beamlines for physics, chemistry, biology, materials research. www.sns.gov #12 · Coproduction of epithermal, thermal and cold neutrons #12;SNS Instrument Beam Lines 1st experimentproposed 2nd

Danon, Yaron

28

THE INFLUENCE OF PRESSURE-DEPENDENT VISCOSITY ON THE THERMAL EVOLUTION OF SUPER-EARTHS  

Science Conference Proceedings (OSTI)

We study the thermal evolution of super-Earths with a one-dimensional (1D) parameterized convection model that has been adopted to account for a strong pressure dependence of the viscosity. A comparison with a 2D spherical convection model shows that the derived parameterization satisfactorily represents the main characteristics of the thermal evolution of massive rocky planets. We find that the pressure dependence of the viscosity strongly influences the thermal evolution of super-Earths-resulting in a highly sluggish convection regime in the lower mantles of those planets. Depending on the effective activation volume and for cooler initial conditions, we observe with growing planetary mass even the formation of a conductive lid above the core-mantle boundary (CMB), a so-called CMB-lid. For initially molten planets our results suggest no CMB-lids but instead a hot lower mantle and core as well as sluggish lower mantle convection. This implies that the initial interior temperatures, especially in the lower mantle, become crucial for the thermal evolution-the thermostat effect suggested to regulate the interior temperatures in terrestrial planets does not work for massive planets if the viscosity is strongly pressure dependent. The sluggish convection and the potential formation of the CMB-lid reduce the convective vigor throughout the mantle, thereby affecting convective stresses, lithospheric thicknesses, and heat fluxes. The pressure dependence of the viscosity may therefore also strongly affect the propensity of plate tectonics, volcanic activity, and the generation of a magnetic field of super-Earths.

Stamenkovic, Vlada; Noack, Lena; Spohn, Tilman [Institute of Planetology, Westfaelische Wilhelms-Universitaet Muenster, Wilhelm-Klemm-Str. 10, 48149 Muenster (Germany); Breuer, Doris, E-mail: Vlada.Stamenkovic@dlr.de, E-mail: Lena.Noack@dlr.de, E-mail: Doris.Breuer@dlr.de, E-mail: Tilman.Spohn@dlr.de [Institute of Planetary Research, German Aerospace Center DLR, Rutherfordstrasse 2, 12489 Berlin (Germany)

2012-03-20T23:59:59.000Z

29

Could strange stars be in the color-flavor-locked phase: Tested by their thermal evolutions  

E-Print Network (OSTI)

The thermal evolution of strange stars in both normal and color-flavor-locked (CFL) phases are investigated together with the evolutions of the stellar rotation and the r-mode instability. The heating effects due to the deconfinement transition of the stellar crust and the dissipation of the r-modes are considered. As a result, the cooling of the stars in the normal phase is found to be not very different from the standard one. In contrast, for the stars in the CFL phase, a big bump during the first hundred years and a steep decay ($\\sim$7% in ten years) at the ages of $\\sim10^{4-6}$ yrs are predicted in their thermal evolution curves. These unique features provide an effective observational test for determining whether or not the CFL phase is reached in strange stars. This thermal test method is independent of and complementary to the rotational test method, which is a direct consequence of the r-mode instability.

Quan Cheng; Yun-Wei Yu; Xiao-Ping Zheng

2013-04-08T23:59:59.000Z

30

Quantum measurements in continuous time, non Markovian evolutions and feedback  

E-Print Network (OSTI)

In this article we reconsider a version of quantum trajectory theory based on the stochastic Schr\\"odinger equation with stochastic coefficients, which was mathematically introduced in the '90s, and we develop it in order to describe the non Markovian evolution of a quantum system continuously measured and controlled thanks to a measurement based feedback. Indeed, realistic descriptions of a feedback loop have to include delay and thus need a non Markovian theory. The theory allows to put together non Markovian evolutions and measurements in continuous time in agreement with the modern axiomatic formulation of quantum mechanics. To illustrate the possibilities of such a theory, we apply it to a two-level atom stimulated by a laser. We introduce closed loop control too, via the stimulating laser, with the aim to enhance the "squeezing" of the emitted light, or other typical quantum properties. Note that here we change the point of view with respect to the usual applications of control theory. In our model the "system" is the two-level atom, but we do not want to control its state, to bring the atom to a final target state. Our aim is to control the "Mandel $Q$-parameter" and the spectrum of the emitted light; in particular the spectrum is not a property at a single time, but involves a long interval of times (a Fourier transform of the autocorrelation function of the observed output is needed).

Alberto Barchielli; Matteo Gregoratti

2011-11-29T23:59:59.000Z

31

Electrical, Frequency and Thermal Measurement and Modelling of Supercapacitor Performance  

E-Print Network (OSTI)

Electrical, Frequency and Thermal Measurement and Modelling of Supercapacitor Performance Yasser--This paper presents an evaluation of commercial supercapacitors performance (ESR, C, self-discharge, Pmax, Emax, coulumbic efficiency, etc), under different conditions. Characterization of supercapacitor

Paris-Sud XI, Université de

32

Microelectronic Thermal Anemometer for the Measurement of Surface Wind  

Science Conference Proceedings (OSTI)

The paper describes the development and first prototype results of a microelectronic thermal anemometer without moving parts, for the measurement of velocity and direction of surface wind. The central part of the instrument is an integrated-...

B. W. Van Oudheusden; J. H. Huijsing

1991-06-01T23:59:59.000Z

33

The evolution of solid density within a thermal explosion II. Dynamic proton radiography of cracking and solid consumption by burning  

Science Conference Proceedings (OSTI)

We report proton transmission images obtained subsequent to the laser assisted thermal ignition of a sample of PBX 9501 (a plastic bonded formulation of the explosive nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)). We describe the laser assisted thermal ignition technique as a means to synchronize a non-linear thermal ignition event while preserving the subsequent post-ignition behavior. We have obtained dynamic proton transmission images at two spatial magnifications and viewed both the radial and transverse axis of a solid cylindrical sample encased in aluminum. Images have been obtained with 3 to 15 {mu}s temporal resolution and approximately 100 {mu}m spatial resolution at the higher magnification. We observe case expansion from very early in the experiment, until case fragmentation. We observe spatially anisotropic features in the transmission which we attribute to cracking in the solid explosive, in agreement with previous measurements conducted on two dimensional samples with optical viewing. Digital analysis of the images also reveals spatially isotropic features which we attribute to the evolution of the loss of density by burning subsequent to thermal ignition.

Smilowitz, L.; Henson, B. F.; Romero, J. J.; Asay, B. W.; Saunders, A.; Merrill, F. E.; Morris, C. L.; Kwiatkowski, K.; Grim, G.; Mariam, F.; Schwartz, C. L.; Hogan, G.; Nedrow, P.; Murray, M. M.; Thompson, T. N.; Espinoza, C.; Lewis, D.; Bainbridge, J.; McNeil, W.; Rightley, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); and others

2012-05-15T23:59:59.000Z

34

Measurement and quantification of aggregate thermal coefficient of expansion  

E-Print Network (OSTI)

The coefficient of thermal expansion of concrete affects thermal related distresses in pavements. Factors affecting expansion of concrete and aggregates along with existing models are reviewed. A test method to measure the coefficient of thermal expansion of aggregates is proposed. Existing methods used to analyze oxide contents are evaluated. A relation between the oxide content of various elements in aggregates and the CTE of aggregate is presented. Results obtained from the proposed method are presented. A model is also presented for the CTE of concrete based on aggregate properties.

Chande, Gautam U

1997-01-01T23:59:59.000Z

35

A model for residual stress evolution in air-plasma-sprayed zirconia thermal barrier coatings  

Science Conference Proceedings (OSTI)

Ruby fluorescence spectroscopy indicates that residual stress in air-plasma-sprayed zirconia thermal barrier coatings is a function of the local interface geometry. The stress profile of a simulated rough interface characterized by ``peaks'' and ``valleys'' was modeled with a finite-element approach that accounted for thermal mismatch, oxide scale growth, and top coat sintering. Dependence of the stress profile on interface geometry and microstructure was investigated, and the results were compared with measured stresses.

Nair, B. G.; Singh, J. P.; Grimsditch, M.

2000-02-28T23:59:59.000Z

36

Evolution of seismic velocities in heavy oil sand reservoirs during thermal recovery process  

E-Print Network (OSTI)

In thermally enhanced recovery processes like cyclic steam stimulation (CSS) or steam assisted gravity drainage (SAGD), continuous steam injection entails changes in pore fluid, pore pressure and temperature in the rock reservoir, that are most often unconsolidated or weakly consolidated sandstones. This in turn increases or decreases the effective stresses and changes the elastic properties of the rocks. Thermally enhanced recovery processes give rise to complex couplings. Numerical simulations have been carried out on a case study so as to provide an estimation of the evolution of pressure, temperature, pore fluid saturation, stress and strain in any zone located around the injector and producer wells. The approach of Ciz and Shapiro (2007) - an extension of the poroelastic theory of Biot-Gassmann applied to rock filled elastic material - has been used to model the velocity dispersion in the oil sand mass under different conditions of temperature and stress. A good agreement has been found between these pre...

Nauroy, Jean-Franois; Guy, N; Baroni, Axelle; Delage, Pierre; Mainguy, Marc; 10.2516/ogst/2012027

2013-01-01T23:59:59.000Z

37

Thermal and Structural Constraints on the Tectonic Evolution of the Idaho-Wyoming-Utah Thrust Belt  

E-Print Network (OSTI)

The timing of motion on thrust faults in the Idaho-Wyoming-Utah (IWU) thrust belt comes from synorogenic sediments, apatite thermochronology and direct dating of fault rocks coupled with good geometrical constraints of the subsurface structure. The thermal history comes from the analyses of apatite thermochronology, thermal maturation of hydrocarbon source rocks and isotope analysis of fluid inclusions from syntectonic veins. New information from zircon fission track and zircon (U-Th)/He analysis provide constraints on the thermal evolution of the IWU thrust belt over geological time. These analyses demonstrate that the time-temperature pathway of the rocks sampled never reached the required conditions to reset the thermochronometers necessary to provide new timing constraints. Previous thermal constraints for maximum temperatures of IWU thrust belt rocks, place the lower limit at ~110C and the upper limit at ~328C. New zircon fission track results suggest an upper limit at ~180C for million year time scales. ID-TIMS and LA-ICPMS of syntectonic calcite veins suggest that new techniques for dating times of active deformation are viable given that radiogenic isotope concentrations occur at sufficient levels within the vein material.

Chapman, Shay Michael

2013-08-01T23:59:59.000Z

38

Soil Thermal Properties Manual for Underground Power Transmission: Soil Thermal Property Measurements, Soil Thermal Stability, and the Use of Corrective Thermal Backfills  

Science Conference Proceedings (OSTI)

The thermal properties of soil used to bury underground transmission cables -- often only crudely estimated in the past -- can have a large impact on the capacity of a transmission system. This guide provides comprehensive information on soil thermal property measurement, surveying, interpretation, and improvement.

1997-12-02T23:59:59.000Z

39

Experimental measurements of the thermal conductivity of ash deposits: Part 1. Measurement technique  

Science Conference Proceedings (OSTI)

This paper describes a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. Since ash deposit thermal conductivity is thought to be strongly dependent on deposit microstructure, the technique is designed to minimize the disturbance of the natural deposit microstructure. Traditional techniques for measuring deposit thermal conductivity generally do not preserve the sample microstructure. Experiments are described that demonstrate the technique, quantify experimental uncertainty, and determine the thermal conductivity of highly porous, unsintered deposits. The average measured conductivity of loose, unsintered deposits is 0.14 {+-} 0.03 W/(m K), approximately midway between rational theoretical limits for deposit thermal conductivity.

A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

2000-04-01T23:59:59.000Z

40

Thermal Transport Measurement of Silicon-Germanium Nanowires  

E-Print Network (OSTI)

Thermal properties of one dimensional nanostructures are of interest for thermoelectric energy conversion. Thermoelectric efficiency is related to non dimensional thermoelectric figure of merit, ZT=S^2 o T/k, where S ,o , k and T are Seebeck coefficient, electrical conductivity, thermal conductivity and the absolute temperature respectively. These physical properties are interdependent. Therefore, making materials with high ZT is a very challenging task. However, nanoscale materials can overcome some of these limitations. When the size of nanomaterials is comparable to wavelength and mean free path of energy carriers, especially phonons, size effect contributes to the thermal conductivity reduction without bringing about major changes in the electrical conductivity and the Seebeck coefficient. Therefore, the figure of merit ZT can be manipulated. For example, the thermal conductivities of several silicon nanowires were more than two orders of magnitude lower than that of bulk silicon values due to the enhanced boundary scattering. Among the nanoscale semiconductor materials, Silicon-Germanium(SiGe) alloy nanowire is a promising candidate for thermoelectric materials The thermal conductivities of SiGe core-shell nanowires with core diameters of 96nm, 129nm and 177nm were measured using a batch fabricated micro device in a temperature range of 40K-450K. SiGe nanowires used in the experiment were synthesized via the Vapour-Liquid-Solid (VLS) growth method. The thermal conductivity data was compared with thermal conductivity of Si and Ge nanowires. The data was compared with SiGe alloy thin film, bulk SiGe, Si/SixGe1-x superlattice nanowire, Si/Si0.7Ge0.3 superlattice thin film and also with the thermal conductivity of Si0.5Ge0.5 calculated using the Einstein model. The thermal conductivities of these SiGe alloy nanowires observed in this work are ~20 times lower than Si nanowires, ~10 times lower than Ge nanowires, ~3-4 times lower than Si/SixGe1-x superlattice thin film, Si/SixGe1-x superlattice nanowire and about 3 time lower than bulk SiGe alloy. The low values of thermal conductivity are majorly due to the effect of alloy scattering, due to increased boundary scattering as a result of nanoscale diameters, and the interface diffuse scattering by core-shell effect. The influence of core-shell effect, alloy scattering and boundary scattering effect in reducing the thermal conductivity of these nanowires opens up opportunities for tuning thermoelectric properties which can pave way to thermoelectric materials with high figures of merit in the future.

Gwak, Yunki

2009-08-01T23:59:59.000Z

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


41

VALIDATION OF A THERMAL CONDUCTIVITY MEASUREMENT SYSTEM FOR FUEL COMPACTS  

SciTech Connect

A high temperature guarded-comparative-longitudinal heat flow measurement system has been built to measure the thermal conductivity of a composite nuclear fuel compact. It is a steady-state measurement device designed to operate over a temperature range of 300 K to 1200 K. No existing apparatus is currently available for obtaining the thermal conductivity of the composite fuel in a non-destructive manner due to the compacts unique geometry and composite nature. The current system design has been adapted from ASTM E 1225. As a way to simplify the design and operation of the system, it uses a unique radiative heat sink to conduct heat away from the sample column. A finite element analysis was performed on the measurement system to analyze the associated error for various operating conditions. Optimal operational conditions have been discovered through this analysis and results are presented. Several materials have been measured by the system and results are presented for stainless steel 304, inconel 625, and 99.95% pure iron covering a range of thermal conductivities of 10 W/m*K to 70 W/m*K. A comparison of the results has been made to data from existing literature.

Jeff Phillips; Colby Jensen; Changhu Xing; Heng Ban

2011-03-01T23:59:59.000Z

42

DIRECT MEASUREMENT OF HEAT FLUX FROM COOLING LAKE THERMAL IMAGERY  

SciTech Connect

Laboratory experiments show a linear relationship between the total heat flux from a water surface to air and the standard deviation of the surface temperature field, {sigma}, derived from thermal images of the water surface over a range of heat fluxes from 400 to 1800 Wm{sup -2}. Thermal imagery and surface data were collected at two power plant cooling lakes to determine if the laboratory relationship between heat flux and {sigma} exists in large heated bodies of water. The heat fluxes computed from the cooling lake data range from 200 to 1400 Wm{sup -2}. The linear relationship between {sigma} and Q is evident in the cooling lake data, but it is necessary to apply band pass filtering to the thermal imagery to remove camera artifacts and non-convective thermal gradients. The correlation between {sigma} and Q is improved if a correction to the measured {sigma} is made that accounts for wind speed effects on the thermal convection. Based on more than a thousand cooling lake images, the correlation coefficients between {sigma} and Q ranged from about 0.8 to 0.9.

Garrett, A; Eliel Villa-Aleman, E; Robert Kurzeja, R; Malcolm Pendergast, M; Timothy Brown, T; Saleem Salaymeh, S

2007-12-19T23:59:59.000Z

43

ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL  

Science Conference Proceedings (OSTI)

This paper develops the zero-dimensional (0D) hydrodynamic coronal loop model 'Enthalpy-based Thermal Evolution of Loops' (EBTEL) proposed by Klimchuk et al., which studies the plasma response to evolving coronal heating, especially impulsive heating events. The basis of EBTEL is the modeling of mass exchange between the corona and transition region (TR) and chromosphere in response to heating variations, with the key parameter being the ratio of the TR to coronal radiation. We develop new models for this parameter that now include gravitational stratification and a physically motivated approach to radiative cooling. A number of examples are presented, including nanoflares in short and long loops, and a small flare. The new features in EBTEL are important for accurate tracking of, in particular, the density. The 0D results are compared to a 1D hydro code (Hydrad) with generally good agreement. EBTEL is suitable for general use as a tool for (1) quick-look results of loop evolution in response to a given heating function, (2) extensive parameter surveys, and (3) situations where the modeling of hundreds or thousands of elemental loops is needed. A single run takes a few seconds on a contemporary laptop.

Cargill, P. J. [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Klimchuk, J. A., E-mail: p.cargill@imperial.ac.uk [NASA Goddard Space Flight Center, Solar Physics Laboratory, Code 671, Greenbelt, MD 20771 (United States)

2012-06-20T23:59:59.000Z

44

THERMAL PERFORMANCE MEASUREMENTS ON ULTIMATE HEAT SINKS - COOLING PONDS  

Office of Scientific and Technical Information (OSTI)

THERMAL PERFORMANCE MEASUREMENTS THERMAL PERFORMANCE MEASUREMENTS ON ULTIMATE HEAT SINKS - COOLING PONDS R. K. Hadlock 0 . B. Abbey Battelle Pacific Northwest Laboratories Prepared for U. S. Nuclear Regulatory Commission b + NOTICE This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Nuclear Regulatory Commission, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, nor assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, pro- duct or process disclosed, nor represents that its use would not infringe privately owned rights. F Available from National Technical Information Service

45

Influence of long-term thermal aging on the microstructural evolution of nuclear reactor pressure vessel materials: An atom probe study  

Science Conference Proceedings (OSTI)

Atom probe field ion microscopy (APFIM) investigations of the microstructure of unaged (as-fabricated) and long-term thermally aged ({approximately} 100,000 h at 280 C) surveillance materials from commercial reactor pressure vessel steels were performed. This combination of materials and conditions permitted the investigation of potential thermal-aging effects. This microstructural study focused on the quantification of the compositions of the matrix and carbides. The APFIM results indicate that there was no significant microstructural evolution after a long-term thermal exposure in weld, plate, or forging materials. The matrix depletion of copper that was observed in weld materials was consistent with the copper concentration in the matrix after the stress-relief heat treatment. The compositions of cementite carbides aged for 100,000 h were compared with the Thermocalc{trademark} prediction. The APFIM comparisons of materials under these conditions are consistent with the measured change in mechanical properties such as the Charpy transition temperature.

Pareige, P.; Russell, K.F.; Stoller, R.E.; Miller, M.K. [Oak Ridge National Lab., TN (United States)

1998-03-01T23:59:59.000Z

46

Measurement of Thermal Dependencies of PBG Fiber Properties  

SciTech Connect

Photonic crystal fibers (PCFs) represent a class of optical fibers which have a wide spectrum of applications in the telecom and sensing industries. Currently, the Advanced Accelerator Research Department at SLAC is developing photonic bandgap particle accelerators, which are photonic crystal structures with a central defect used to accelerate electrons and achieve high longitudinal electric fields. Extremely compact and less costly than the traditional accelerators, these structures can support higher accelerating gradients and will open a new era in high energy physics as well as other fields of science. Based on direct laser acceleration in dielectric materials, the so called photonic band gap accelerators will benefit from mature laser and semiconductor industries. One of the key elements to direct laser acceleration in hollow core PCFs, is maintaining thermal and structural stability. Previous simulations demonstrate that accelerating modes are sensitive to the geometry of the defect region and the variations in the effective index. Unlike the telecom modes (for which over 95% of the energy propagates in the hollow core) most of the power of these modes is located in the glass at the periphery of the central hole which has a higher thermal constant than air ({gamma}{sub SiO{sub 2}} = 1.19 x 10{sup -6} 1/K, {gamma}{sub air} = -9 x 10{sup -7} 1/K with {gamma} = dn/dT). To fully control laser driven acceleration, we need to evaluate the thermal and structural consequences of such modes on the PCFs. We are conducting series of interferometric tests to quantify the dependencies of the HC-633-02 (NKT Photonics) propagation constant (k{sub z}) on temperature, vibration amplitude, stress and electric field strength. In this paper we will present the theoretical principles characterizing the thermal behavior of a PCF, the measurements realized for the fundamental telecom mode (TE{sub 00}), and the experimental demonstration of TM-like mode propagation in the HC-633-02 fiber.

Laouar, Rachik

2011-07-06T23:59:59.000Z

47

LengthEvolution from Measurement Standard to a ...  

Science Conference Proceedings (OSTI)

... measurements. References. [1] HG Jarrard, DB McNeill, A Dictionary of Scientific Units, Chapman and Hall, 1964, p. 85. ...

2011-12-15T23:59:59.000Z

48

Photoluminescence study of the structural evolution of amorphous and crystalline silicon nanoclusters during the thermal annealing of silicon suboxide films with different stoichiometry  

SciTech Connect

The effect of the stoichiometry of thin silicon suboxide films on the processes of the formation and evolution of silicon nanoclusters during thermal annealing is studied by photoluminescence measurements. The samples are produced by the thermal sputtering of a SiO powder in an oxygen atmosphere, with the subsequent deposition of a 500 nm-thick SiO{sub x} layer onto a Si substrate. The morphological properties and size of Si nanoclusters are explored by analyzing the photoluminescence spectra and kinetics. A comparative study of the luminescence properties of thin SiO{sub x} layers with different stoichiometric parameters, x = 1.10, 1.29, 1.56, and 1.68, is accomplished for samples annealed at different temperatures in the range 850 to 1200 Degree-Sign C. The dependences of the photoluminescence decay time on the annealing temperature, the stoichiometric parameter of the initial silicon suboxide film, and the nanocluster size are studied.

Zhigunov, D. M., E-mail: dmzhigunov@physics.msu.ru; Shvydun, N. V.; Emelyanov, A. V.; Timoshenko, V. Yu.; Kashkarov, P. K. [Lomonosov Moscow State University, Physics Department (Russian Federation); Seminogov, V. N. [Russian Academy of Sciences, Institute of Laser and Information Technologies (Russian Federation)

2012-03-15T23:59:59.000Z

49

Thirty Stage Annular Centrifugal Contactor Thermal Profile Measurements  

Science Conference Proceedings (OSTI)

A thirty stage 5 cm annular centrifugal contactor cascade has been assembled and tested to obtain thermal profiles during both ambient and heated input conditions of operation. Thermocouples were installed on every stage as well as feed inputs and Real-time data was taken during experiments lasting from two to eight hours at total flow rates of 0.5 to 1.4 liters per minute. Ambient temperature profile results show that only a small amount of heat is generated by the mechanical energy of the contactors. Steady state temperature profiles mimic the ambient temperature of the lab but are higher toward the middle of the cascade. Heated inlet solutions gave temperature profiles with smaller temperature gradients, more driven by the temperature of the inlet solutions than ambient lab temperature. Temperature effects of solution mixing, even at rotor speeds of 4000 rpm, were not measurable.

David H. Meikrantz; Troy G. Garn; Jack D. Law

2010-02-01T23:59:59.000Z

50

Simulated evolution of fractures and fracture networks subject to thermal cooling: A coupled discrete element and heat conduction model  

SciTech Connect

Advancement of EGS requires improved prediction of fracture development and growth during reservoir stimulation and long-term operation. This, in turn, requires better understanding of the dynamics of the strongly coupled thermo-hydro-mechanical (THM) processes within fractured rocks. We have developed a physically based rock deformation and fracture propagation simulator by using a quasi-static discrete element model (DEM) to model mechanical rock deformation and fracture propagation induced by thermal stress and fluid pressure changes. We also developed a network model to simulate fluid flow and heat transport in both fractures and porous rock. In this paper, we describe results of simulations in which the DEM model and network flow & heat transport model are coupled together to provide realistic simulation of the changes of apertures and permeability of fractures and fracture networks induced by thermal cooling and fluid pressure changes within fractures. Various processes, such as Stokes flow in low velocity pores, convection-dominated heat transport in fractures, heat exchange between fluid-filled fractures and solid rock, heat conduction through low-permeability matrices and associated mechanical deformations are all incorporated into the coupled model. The effects of confining stresses, developing thermal stress and injection pressure on the permeability evolution of fracture and fracture networks are systematically investigated. Results are summarized in terms of implications for the development and evolution of fracture distribution during hydrofracturing and thermal stimulation for EGS.

Huang, Hai; Plummer, Mitchell; Podgorney, Robert

2013-02-01T23:59:59.000Z

51

A Method to Correct the Thermal Dome Effect of Pyranometers in Selected Historical Solar Irradiance Measurements  

Science Conference Proceedings (OSTI)

In using pyranometers to measure solar irradiance, it is important to know the magnitudes and the consequences of the thermal effect, which is introduced by the glass domes of the instruments. Historically, the thermal dome effect was not ...

Qiang Ji

2007-03-01T23:59:59.000Z

52

Spatially localized measurement of thermal conductivity using a hybrid photothermal technique  

SciTech Connect

A photothermal technique capable of measuring thermal conductivity with micrometer lateral resolution is presented. This technique involves measuring separately the thermal diffusivity, D, and thermal effusivity, e, to extract the thermal conductivity, k=(e2/D)1/2. To generalize this approach, sensitivity analysis was conducted for materials having a range of thermal conductivities. Experimental validation was sought using two substrate materials, SiO2 and CaF2, both coated with thin titanium films. The measured conductivities compare favorably with literature values.

David H Hurley; Marat Khafizov; Zilong Hua; Rory Kennedy; Heng Ban

2012-05-01T23:59:59.000Z

53

Remote Sensing Measurements of Tropospheric Ozone by Ground-Based Thermal Emission Spectroscopy  

Science Conference Proceedings (OSTI)

Remote sensing measurements of the troposphere were obtained by a new technique in which spectra of the downward thermal radiation from tropospheric ozone were measured with a Fourier transform infrared spectrometer. The measurements were ...

W. F. J. Evans; E. Puckrin

1999-01-01T23:59:59.000Z

54

MagmaHeatNS1D: One-dimensional visualization numerical simulator for computing thermal evolution in a contact metamorphic aureole  

Science Conference Proceedings (OSTI)

MagmaHeatNS1D is an IDL (Interactive Data Language) program that is aimed at numerically modeling heat transfer from an igneous intrusion to its host rocks and providing important thermal state information for minerals and organic matters in a contact ... Keywords: Contact metamorphism, Heat transfer model, Igneous intrusion, Maturation, Numerical simulation, Thermal evolution

Dayong Wang

2013-04-01T23:59:59.000Z

55

Developing Test Procedures for Measuring Stored Thermal Energy in Firefighter Protective Clothing.  

E-Print Network (OSTI)

??This research studied stored thermal energy in fire fighter's turnout systems. It developed a novel laboratory apparatus and test protocols for measuring the contribution of (more)

Eni, Egbe Uchechi

2005-01-01T23:59:59.000Z

56

Measurement of thermal noise in multilayer coatings with optimized layer thickness  

Science Conference Proceedings (OSTI)

A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise for a prescribed reflectivity. Coatings with the layer thicknesses optimized to minimize thermal noise could be useful in future generation interferometric gravitational wave detectors where coating thermal noise is expected to limit the sensitivity of the instrument. We present the results of direct measurements of the thermal noise of a standard quarter-wavelength coating and a low noise optimized coating. The measurements indicate a reduction in thermal noise in line with modeling predictions.

Villar, Akira E.; Black, Eric D.; DeSalvo, Riccardo; Libbrecht, Kenneth G.; Michel, Christophe; Morgado, Nazario; Pinard, Laurent; Pinto, Innocenzo M.; Pierro, Vincenzo; Galdi, Vincenzo; Principe, Maria; Taurasi, Ilaria [LIGO Laboratory, California Institute of Technology, Mail Code 264-33, Pasadena, California 91125 (United States); Laboratoire des Materiaux Avances, Universite Claude Bernard Lyon 1, CNRS/IN2P3, Villeurbaune (France); Waves Group, University of Sannio at Benevento, Benevento, Italy, INFN and LSC (Italy)

2010-06-15T23:59:59.000Z

57

First Results of Scanning Thermal Diffusivity Microscope (STDM) Measurements on Irradiated Monolithic and Dispersion Fuel  

SciTech Connect

The thermal conductivity of the fuel material in a reactor before and during irradiation is a sensitive and fundamental parameter for thermal hydraulic calculations that are useds to correctly determine fuel heat fluxes and meat temperatures and to simulate performance of the fuel elements during operation. Several techniques have been developed to measure the thermal properties of fresh fuel to support these calculations, but it is crucial to also investigate the change of thermal properties during irradiation.

T. K. Huber; M. K. Figg; J. R. Kennedy; A. B. Robinson; D. M. Wachs

2012-07-01T23:59:59.000Z

58

Interim procedure to measure the thermal performance of window systems  

SciTech Connect

The purpose of the report is to review the current sources of information on U-values and to describe the state of thermal test methods used for windows in order to provide the Bonneville Power Administration with some general guidelines in the application of thermal test data for use in the Model Conservation Standards (MCS) by the Northwest Power Planning Council. At present, considerable controversy exists in the window industry regarding the thermal testing of windows, therefore no consensus-based standards are available.

McCabe, M.E.; Goss, W.P.

1987-06-01T23:59:59.000Z

59

Software architecture graphs as complex networks: A novel partitioning scheme to measure stability and evolution  

Science Conference Proceedings (OSTI)

The stability and evolution of the structure of consecutive versions of a series of software architecture graphs are analysed using the theory of complex networks. Brief comparisons are drawn between the scale-free behaviour and second order phase transitions. ... Keywords: Complexity, Directed network, Lehman's laws, Power law, Scale-free, Software measurement, Software metric

S. Jenkins; S. R. Kirk

2007-06-01T23:59:59.000Z

60

In situ measurements of stress evolution in silicon thin films during  

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

In situ measurements of stress evolution in silicon thin films during In situ measurements of stress evolution in silicon thin films during electrochemical lithiation and delithiation Title In situ measurements of stress evolution in silicon thin films during electrochemical lithiation and delithiation Publication Type Journal Article Year of Publication 2010 Authors Sethuraman, Vijay A., Michael J. Chon, Maxwell Shimshak, Venkat Srinivasan, and Pradeep R. Guduru Journal Journal of Power Sources Volume 195 Start Page 5062 Issue 15 Pagination 5062-5066 Date Published 08/2010 Keywords In situ stress measurement, Lithium-ion battery, Mechanical dissipation, Multi-beam optical sensor (MOS), Open-circuit relaxation, Silicon anode Abstract We report in situ measurements of stress evolution in a silicon thin-film electrode during electrochemical lithiation and delithiation by using the multi-beam optical sensor (MOS) technique. Upon lithiation, due to substrate constraint, the silicon electrode initially undergoes elastic deformation, resulting in rapid rise of compressive stress. The electrode begins to deform plastically at a compressive stress of ca. -1.75 GPa; subsequent lithiation results in continued plastic strain, dissipating mechanical energy. Upon delithiation, the electrode first undergoes elastic straining in the opposite direction, leading to a tensile stress of ca. 1 GPa; subsequently, it deforms plastically during the rest of delithiation. The plastic flow stress evolves continuously with lithium concentration. Thus, mechanical energy is dissipated in plastic deformation during both lithiation and delithiation, and it can be calculated from the stress measurements; we show that it is comparable to the polarization loss. Upon current interruption, both the film stress and the electrode potential relax with similar time constants, suggesting that stress contributes significantly to the chemical potential of lithiated silicon.

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


61

CALIBRATING 100 YEARS OF POLAR FACULAE MEASUREMENTS: IMPLICATIONS FOR THE EVOLUTION OF THE HELIOSPHERIC MAGNETIC FIELD  

Science Conference Proceedings (OSTI)

Although the Sun's polar magnetic fields are thought to provide important clues for understanding the 11 year sunspot cycle, including the observed variations of its amplitude and period, the current database of high-quality polar field measurements spans relatively few sunspot cycles. In this paper, we address this deficiency by consolidating Mount Wilson Observatory polar faculae data from four data reduction campaigns, validating it through a comparison with facular data counted automatically from Michelson Doppler Imager (MDI) intensitygrams, and calibrating it against polar field measurements taken by the Wilcox Solar Observatory and average polar field and total polar flux calculated using MDI line-of-sight magnetograms. Our results show that the consolidated polar facular measurements are in excellent agreement with both polar field and polar flux estimates, making them an ideal proxy to study the evolution of the polar magnetic field. Additionally, we combine this database with sunspot area measurements to study the role of the polar magnetic flux in the evolution of the heliospheric magnetic field (HMF). We find that there is a strong correlation between HMF and polar flux at solar minimum and that, taken together, polar flux and sunspot area are better at explaining the evolution of the HMF during the last century than sunspot area alone.

Munoz-Jaramillo, Andres; DeLuca, Edward E. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Sheeley, Neil R. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Zhang, Jie, E-mail: amunoz@cfa.harvard.edu, E-mail: edeluca@cfa.harvard.edu, E-mail: neil.sheeley@nrl.navy.mil, E-mail: jzhang7@gmu.edu [School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, VA 22030 (United States)

2012-07-10T23:59:59.000Z

62

The Effect of Latent Heat Release on the Evolution of a Warm Occluded Thermal Structure  

Science Conference Proceedings (OSTI)

The effect of latent heat release on the development of the occluded thermal structure in a major winter storm is examined through comparison of full physics (FP) and no-latent-heat-release (NLHR) simulations of the event performed using the ...

Derek J. Posselt; Jonathan E. Martin

2004-02-01T23:59:59.000Z

63

Bond strength and stress measurements in thermal barrier coatings  

DOE Green Energy (OSTI)

Thermal barrier coatings have been used extensively in aircraft gas turbines for more than 15 years to insulate combustors and turbine vanes from the hot gas stream. Plasma sprayed thermal barrier coatings (TBCs) provide metal temperature reductions as much as 300{degrees}F, with improvements in durability of two times or more being achieved. The introduction of TBCs deposited by electron beam physical vapor deposition (EB-PVD) processes in the last five years has provided a major improvement in durability and also enabled TBCs to be applied to turbine blades for improved engine performance. This program evaluates the bond strength of yttria stabilized zirconia coatings with MCrAlY and Pt-Al bond coats utilizing diffraction and fluorescence methods.

Gell, M.; Jordan, E.

1995-12-31T23:59:59.000Z

64

Critical Evaluation of Current Skin Thermal Property Measurements  

E-Print Network (OSTI)

Burn treatment is an area of major importance in medicine, however, there is not currently an analytic method to determine the depth and magnitude of burns. Complications, such as a relative lack of knowledge of the specific thermal properties of skin and the relation between heat transfer and biological processes, have prevented a comprehensive model to explain the field of bioheat transfer. Research was conducted to estimate the relevant thermal and material properties in the field of bioheat transfer. Subsequently, an experiment was proposed, and a mathematical model was developed for the experiment, to allow for detection of burns through the use of heat transfer analysis. Burned skin and healthy skin differ in that there is no blood flow and thus no directionality to the heat transfer in burned skin. Thus, the experiment was designed to determine if there was a directionality was present in the heat transfer in the skin. Using the estimated skin properties, calculations were done to determine the viability of the proposed experiment. The experiment was refined to account for the findings and modified to more accurately detect burns in human skin. 1

Anand Mani

2013-01-01T23:59:59.000Z

65

Development of a nanostructure thermal property measurement platform compatible with a transmission electron microscope  

E-Print Network (OSTI)

Measurements of the electrical and thermal transport properties of one-dimensional nanostructures (e.g., nanotubes and nanowires) typically are obtained without detailed knowledge of the specimen's atomicscale structure ...

Harris, C. Thomas (Charles Thomas)

2010-01-01T23:59:59.000Z

66

Effective thermal conductivity measurements relevant to deep borehole nuclear waste disposal  

E-Print Network (OSTI)

The objective of this work was to measure the effective thermal conductivity of a number of materials (particle beds, and fluids) proposed for use in and around canisters for disposal of high level nuclear waste in deep ...

Shaikh, Samina

2007-01-01T23:59:59.000Z

67

A17: Heat Capacity and Thermal Expansion Measurements of Solar ...  

Science Conference Proceedings (OSTI)

One of the main tasks for getting reliable cp and enthalpy data of solar salts is therefore to find the right measurement parameters and crucible material/salt...

68

Estimation of Thermal Resistance from Room Temperature Electrical Resistance Measurements for Different LHC Beam Screen Support Systems  

E-Print Network (OSTI)

In this note the thermal resistance between the LHC beam screen and cold bore is estimated from room temperature electrical resistance measurements. The results indicate that the beam screen without supports should have a comparable, if not better, thermal performance than the one with the existing spring supports. This prediction from electrical resistance measurements is confirmed by recent preliminary thermal measurements.

Jenninger, B

1999-01-01T23:59:59.000Z

69

Evolution of Thermally Pulsing Asymptotic Giant Branch Stars III. Dust production at supersolar metallicities  

E-Print Network (OSTI)

We extend the formalism presented in our recent calculations of dust ejecta from the Thermally Pulsing Asymptotic Giant Branch (TP-AGB) phase, to the case of super-solar metallicity stars. The TP-AGB evolutionary models are computed with the COLIBRI code. We adopt our preferred scheme for dust growth. For M-giants, we neglect chemisputtering by H$_2$ molecules and, for C-stars we assume a homogeneous growth scheme which is primarily controlled by the carbon over oxygen excess. At super-solar metallicities, dust forms more efficiently and silicates tend to condense significantly closer to the photosphere (r~1.5 R$_*$) - and thus at higher temperatures and densities - than at solar and sub-solar metallicities (r~2-3 R$_*$). In such conditions, the hypothesis of thermal decoupling between gas and dust becomes questionable, while dust heating due to collisions plays an important role. The heating mechanism delays dust condensation to slightly outer regions in the circumstellar envelope. We find that the same mech...

Nanni, Ambra; Marigo, Paola; Girardi, Lo

2013-01-01T23:59:59.000Z

70

A field measurement system for the study of thermal comfort  

E-Print Network (OSTI)

metal screen. A platinum RTD measured air sors usedin theAir Temperature platinum RTD IVlEASURENIENT ACCURACY,Surface Temperature platinum RTD M: 06 m N/A N/A -+ 0 5C

Benton, C.; Bauman, Fred; Fountain, M.

1990-01-01T23:59:59.000Z

71

The thermal conductivity of rock under hydrothermal conditions: measurements and applications  

SciTech Connect

The thermal conductivities of most major rock-forming minerals vary with both temperature and confining pressure, leading to substantial changes in the thermal properties of some rocks at the high temperatures characteristic of geothermal systems. In areas with large geothermal gradients, the successful use of near-surface heat flow measurements to predict temperatures at depth depends upon accurate corrections for varying thermal conductivity. Previous measurements of the thermal conductivity of dry rock samples as a function of temperature were inadequate for porous rocks and susceptible to thermal cracking effects in nonporous rocks. We have developed an instrument for measuring the thermal conductivity of water-saturated rocks at temperatures from 20 to 350 C and confining pressures up to 100 MPa. A transient line-source of heat is applied through a needle probe centered within the rock sample, which in turn is enclosed within a heated pressure vessel with independent controls on pore and confining pressure. Application of this technique to samples of Franciscan graywacke from The Geysers reveals a significant change in thermal conductivity with temperature. At reservoir-equivalent temperatures of 250 C, the conductivity of the graywacke decreases by approximately 25% relative to the room temperature value. Where heat flow is constant with depth within the caprock overlying the reservoir, this reduction in conductivity with temperature leads to a corresponding increase in the geothermal gradient. Consequently, reservoir temperature are encountered at depths significantly shallower than those predicted by assuming a constant temperature gradient with depth. We have derived general equations for estimating the thermal conductivity of most metamorphic and igneous rocks and some sedimentary rocks at elevated temperature from knowledge of the room temperature thermal conductivity. Application of these equations to geothermal exploration should improve estimates of subsurface temperatures derived from heat flow measurements.

Williams, Colin F.; Sass, John H.

1996-01-24T23:59:59.000Z

72

Measure of Diffusion Model Error for Thermal Radiation Transport  

E-Print Network (OSTI)

The diffusion approximation to the equation of transfer (Boltzmann transport equation) is usually applied to media where scattering dominates the interactions. Diffusion approximation helps in significant savings in terms of code complexity and computational time. However, this approximation often has significant error. Error due to the inherent nature of a physics model is called model error. Information about the model error associated with the diffusion approximation is clearly desirable. An indirect measure of model error is a quantity that is related in some way to the error but not equal to the error. In general, indirect measures of error are expected to be less costly than direct measures. Perhaps the most well-known indirect measure of the diffusion model error is the variable-Eddington tensor. This tensor provides a great deal of information about the angular dependence of the angular intensity solution, but it is not always simple to interpret. We define a new indirect measure of the diffusion model error called the diffusion model error source (DME source). When this DME source is added to the diffusion equation, the transport solution for the angular-integrated intensity is obtained. In contrast to the variable-Eddington tensor, our DME source is a scalar that is conceptually easy to interpret. In addition to defining the DME source analytically, we show how to generate this source numerically relative to the Sn radiative transfer equations with linear-discontinuous spatial discretization. This numerical source is computationally tested and shown to reproduce the Sn solution for a number of problems. Our radiative transfer model solves a coupled, time dependent, multi-frequency, 1-D slab equation and material heat transfer equation. We then use diffusion approximation to solve the same problem. The difference due to this approximation can be modelled by a diffusion source. The diffusion source is defined as an amount of inhomogeneous source that, when added to a diffusion calculation, gives a solution for the angle-integrated intensity that is equal to the transport solution.

Kumar, Akansha

2013-05-01T23:59:59.000Z

73

Report on Thermal Neutron Diffusion Length Measurement in Reactor Grade Graphite Using MCNP and COMSOL Multiphysics  

E-Print Network (OSTI)

Neutron diffusion length in reactor grade graphite is measured both experimentally and theoretically. The experimental work includes Monte Carlo (MC) coding using 'MCNP' and Finite Element Analysis (FEA) coding suing 'COMSOL Multiphysics' and Matlab. The MCNP code is adopted to simulate the thermal neutron diffusion length in a reactor moderator of 2m x 2m with slightly enriched uranium ($^{235}U$), accompanied with a model designed for thermal hydraulic analysis using point kinetic equations, based on partial and ordinary differential equation. The theoretical work includes numerical approximation methods including transcendental technique to illustrate the iteration process with the FEA method. Finally collision density of thermal neutron in graphite is measured, also specific heat relation dependability of collision density is also calculated theoretically, the thermal neutron diffusion length in graphite is evaluated at $50.85 \\pm 0.3cm$ using COMSOL Multiphysics and $50.95 \\pm 0.5cm$ using MCNP. Finally ...

Mirfayzi, S R

2013-01-01T23:59:59.000Z

74

Autonomous Measurements of Sea Surface Temperature Using In Situ Thermal Infrared Data  

Science Conference Proceedings (OSTI)

In situ and autonomous measurements of sea surface temperature (SST) have been performed with a thermal infrared radiometer mounted on a fixed oil rig. The accuracy limit was established at 0.3 K for these SST measurements in order to meet the ...

Raquel Nicls; Vicente Caselles; Csar Coll; Enric Valor; Eva Rubio

2004-04-01T23:59:59.000Z

75

MEASUREMENT OF THE HUMIDITY OF SOILS BY DIFFUSION OF A BEAM OF THERMAL NEUTRONS  

SciTech Connect

From earlier results on the measurement of soil humidity an apparatus was constructed and calibrated for the measurement of the humidity of soils by diffusion of a beam of thermal neutrons. The construction and calibration of this apparatus are described in detail. (J.S.R.)

Wack, B.

1962-02-01T23:59:59.000Z

76

Direct Measurement of EGR Cooler Deposit Thermal Properties for Improved Understanding of Cooler Fouling  

DOE Green Energy (OSTI)

Exhaust gas recirculation (EGR) cooler fouling has become a significant issue for compliance with NOX emissions standards. This paper reports results of a study of fundamental aspects of EGR cooler fouling. An apparatus and procedure were developed to allow surrogate EGR cooler tubes to be exposed to diesel engine exhaust under controlled conditions. The resulting fouled tubes were removed and analyzed. Volatile and non-volatile deposit mass was measured for each tube. Thermal diffusivity of the deposited soot cake was measured by milling a window into the tube and using the Xenon flash lamp method. The heat capacity of the deposit was measured at temperatures up to 430 C and was slightly higher than graphite, presumably due to the presence of hydrocarbons. These measurements were combined to allow calculation of the deposit thermal conductivity, which was determined to be 0.041 W/mK, only ~1.5 times that of air and much lower than the 304 stainless steel tube (14.7 W/mK). The main determinant of the deposit thermal conductivity is density, which was measured to be just 2% that of the density of the primary soot particles (or 98% porous). The deposit layer thermal resistance was calculated and compared with estimates of the thermal resistance calculated from gas temperature data during the experiment. The deposit properties were also used to further analyze the temperature data collected during the experiment.

Wang, Hsin [ORNL; Sluder, Scott [ORNL; Storey, John Morse [ORNL

2009-01-01T23:59:59.000Z

77

Soil Thermal Resistivity and Thermal Stability Measuring Instrument: Volume 5: Abridged Manual for Use of the Statistical Weather Analysis Program  

Science Conference Proceedings (OSTI)

Numerous considerations influence the thermal design of an underground power cable, including the soil thermal resistivity, thermal diffusivity, and thermal stability. Each of these properties is a function of soil moisture which is, in turn, a function of past weather, soil composition, and biological burden. The Neher-McGrath formalism has been widely used for thermal cable design. However, this formalism assumes knowledge of soil thermal properties. For design purposes, these parameters should be trea...

1981-12-01T23:59:59.000Z

78

Simultaneous measurement of the thermal conductivity and thermal diffusivity of unconsolidated materials by the transient hot wire method  

Science Conference Proceedings (OSTI)

This paper describes a new design for the transient hot wire method that can obtain the thermal conductivity and thermal diffusivity of unconsolidated materials. In this method

Greg C. Glatzmaier; W. Fred Ramirez

1985-01-01T23:59:59.000Z

79

Evolution of block-copolymer order through a moving thermal zone  

Science Conference Proceedings (OSTI)

We investigate block-copolymer (BCP) thin film ordering kinetics during annealing across a moving in-plane temperature gradient. We operate in the so-called cold zone annealing (CZA) regime, where ordering temperatures are above the glass-transition, but well below the order-disorder transition. By measuring the order through the in-plane gradient, using atomic force microscopy and grazing-incidence small-angle X-ray scattering (GISAXS), we confirm that CZA greatly enhances ordering kinetics, as compared to uniform oven annealing. The maximal ordering occurs over a narrow range of the heating-up phase, and not during the subsequent cooling phase. The large grain sizes obtained using CZA are due to enhanced kinetics, and not the preferential formation of certain grain orientations. Kinetic enhancement is apparent even below the bulk glass-transition temperature. We suggest that the in-plane temperature gradient drives enhanced kinetics.

Yager, Kevin G.; Fredin, Nathaniel J.; Zhang, Xiaohua; Berry, Brian C.; Karim, Alamgir; Jones, Ronald L. (Akron)

2012-07-11T23:59:59.000Z

80

Estimation of in-situ thermal conductivities from temperature gradient measurements  

Science Conference Proceedings (OSTI)

A mathematical model has been developed to study the effect of variable thermal conductivity of the formations, and the wellbore characteristics, on the fluid temperature behavior inside the wellbore during injection or production and after shut-in. During the injection or production period the wellbore fluid temperature is controlled mainly by the fluid flow rate and the heat lost from the fluid to the formation. During the shut-in period, the fluid temperature is strongly affected by differences in the formation thermal conductivities. Based on the results of the present analysis, two methods for estimating in-situ thermal conductivity were derived. First, the line source concept is extended to estimate values of the formation thermal conductivities utilizing the fluid temperature record during the transient period of injection or production and shut-in. The second method is applied when a well is under thermal equilibrium conditions. Values of the formation thermal conductivities can also be estimated by using a continuous temperature gradient log and by measuring the thermal conductivity of the formation at a few selected wellbore locations.

Hoang, V.T.

1980-12-01T23:59:59.000Z

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81

Formation and evolution of interstellar filaments; Hints from velocity dispersion measurements  

E-Print Network (OSTI)

We investigate the gas velocity dispersions of a sample of filaments recently detected as part of the Herschel Gould Belt Survey in the IC5146, Aquila, and Polaris interstellar clouds. To measure these velocity dispersions, we use 13CO, C18O, and N2H+ line observations obtained with the IRAM 30m telescope. Correlating our velocity dispersion measurements with the filament column densities derived from Herschel data, we show that interstellar filaments can be divided into two regimes: thermally subcritical filaments, which have transonic velocity dispersions (c_s ~dispersions scaling roughly as the square root of column density (\\sigma_tot ~ \\Sigma^0.5), and are self-gravitating. The higher velocity dispersions of supercritical filaments may not directly arise from supersonic interstellar turbulence but may be driven by gravitational contraction/accretion...

Arzoumanian, Doris; Peretto, Nicolas; Konyves, Vera

2013-01-01T23:59:59.000Z

82

EVOLUTION OF THE VELOCITY-DISPERSION FUNCTION OF LUMINOUS RED GALAXIES: A HIERARCHICAL BAYESIAN MEASUREMENT  

SciTech Connect

We present a hierarchical Bayesian determination of the velocity-dispersion function of approximately 430,000 massive luminous red galaxies observed at relatively low spectroscopic signal-to-noise ratio (S/N {approx} 3-5 per 69 km s{sup -1}) by the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III. We marginalize over spectroscopic redshift errors, and use the full velocity-dispersion likelihood function for each galaxy to make a self-consistent determination of the velocity-dispersion distribution parameters as a function of absolute magnitude and redshift, correcting as well for the effects of broadband magnitude errors on our binning. Parameterizing the distribution at each point in the luminosity-redshift plane with a log-normal form, we detect significant evolution in the width of the distribution toward higher intrinsic scatter at higher redshifts. Using a subset of deep re-observations of BOSS galaxies, we demonstrate that our distribution-parameter estimates are unbiased regardless of spectroscopic S/N. We also show through simulation that our method introduces no systematic parameter bias with redshift. We highlight the advantage of the hierarchical Bayesian method over frequentist 'stacking' of spectra, and illustrate how our measured distribution parameters can be adopted as informative priors for velocity-dispersion measurements from individual noisy spectra.

Shu Yiping; Bolton, Adam S.; Dawson, Kyle S.; Brownstein, Joel R. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112 (United States); Schlegel, David J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Wake, David A. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Brinkmann, Jon [Apache Point Observatory, Apache Point Road, P.O. Box 59, Sunspot, NM 88349 (United States); Weaver, Benjamin A., E-mail: yiping.shu@utah.edu, E-mail: bolton@astro.utah.edu [Center for Cosmology and Particle Physics, New York University, NY 10003 (United States)

2012-04-15T23:59:59.000Z

83

Measurements of Electron Thermal Transport due to Electron Temperature Gradient Modes in a Basic Experiment  

Science Conference Proceedings (OSTI)

Production and identification of electron temperature gradient modes have already been reported [X. Wei, V. Sokolov, and A. K. Sen, Phys. Plasmas 17, 042108 (2010)]. Now a measurement of electron thermal conductivity via a unique high frequency triple probe yielded a value of {chi}{sub perpendiculare} ranging between 2 and 10 m{sup 2}/s, which is of the order of a several gyrobohm diffusion coefficient. This experimental result appears to agree with a value of nonlocal thermal conductivity obtained from a rough theoretical estimation and not inconsistent with gyrokinetic simulation results for tokamaks. The first experimental scaling of the thermal conductivity versus the amplitude of the electron temperature gradient fluctuation is also obtained. It is approximately linear, indicating a strong turbulence signature.

Sokolov, V.; Sen, A. K. [Plasma Research Laboratory, Columbia University, New York, New York 10027 (United States)

2011-10-07T23:59:59.000Z

84

Report on Thermal Neutron Diffusion Length Measurement in Reactor Grade Graphite Using MCNP and COMSOL Multiphysics  

E-Print Network (OSTI)

Neutron diffusion length in reactor grade graphite is measured both experimentally and theoretically. The experimental work includes Monte Carlo (MC) coding using 'MCNP' and Finite Element Analysis (FEA) coding suing 'COMSOL Multiphysics' and Matlab. The MCNP code is adopted to simulate the thermal neutron diffusion length in a reactor moderator of 2m x 2m with slightly enriched uranium ($^{235}U$), accompanied with a model designed for thermal hydraulic analysis using point kinetic equations, based on partial and ordinary differential equation. The theoretical work includes numerical approximation methods including transcendental technique to illustrate the iteration process with the FEA method. Finally collision density of thermal neutron in graphite is measured, also specific heat relation dependability of collision density is also calculated theoretically, the thermal neutron diffusion length in graphite is evaluated at $50.85 \\pm 0.3cm$ using COMSOL Multiphysics and $50.95 \\pm 0.5cm$ using MCNP. Finally the total neutron cross-section is derived using FEA in an inverse iteration form.

S. R. Mirfayzi

2013-01-08T23:59:59.000Z

85

Characterization of the Thermal Structure inside an Urban Canyon: Field Measurements and Validation of a Simple Model  

Science Conference Proceedings (OSTI)

The results of measurement campaigns are analyzed to investigate the thermal structure in an urban canyon and to validate a simplified model simulating the air and surface temperatures from surface energy budgets. Starting from measurements at ...

Lorenzo Giovannini; Dino Zardi; Massimiliano de Franceschi

2013-01-01T23:59:59.000Z

86

Measurement of neutron capture on $^{48}$Ca at thermal and thermonuclear energies  

E-Print Network (OSTI)

At the Karlsruhe pulsed 3.75\\,MV Van de Graaff accelerator the thermonuclear $^{48}$Ca(n,$\\gamma$)$^{49}$Ca(8.72\\,min) cross section was measured by the fast cyclic activation technique via the 3084.5\\,keV $\\gamma$-ray line of the $^{49}$Ca-decay. Samples of CaCO$_3$ enriched in $^{48}$Ca by 77.87\\,\\% were irradiated between two gold foils which served as capture standards. The capture cross-section was measured at the neutron energies 25, 151, 176, and 218\\,keV, respectively. Additionally, the thermal capture cross-section was measured at the reactor BR1 in Mol, Belgium, via the prompt and decay $\\gamma$-ray lines using the same target material. The $^{48}$Ca(n,$\\gamma$)$^{49}$Ca cross-section in the thermonuclear and thermal energy range has been calculated using the direct-capture model combined with folding potentials. The potential strengths are adjusted to the scattering length and the binding energies of the final states in $^{49}$Ca. The small coherent elastic cross section of $^{48}$Ca+n is explained through the nuclear Ramsauer effect. Spectroscopic factors of $^{49}$Ca have been extracted from the thermal capture cross-section with better accuracy than from a recent (d,p) experiment. Within the uncertainties both results are in agreement. The non-resonant thermal and thermonuclear experimental data for this reaction can be reproduced using the direct-capture model. A possible interference with a resonant contribution is discussed. The neutron spectroscopic factors of $^{49}$Ca determined from shell-model calculations are compared with the values extracted from the experimental cross sections for $^{48}$Ca(d,p)$^{49}$Ca and $^{48}$Ca(n,$\\gamma$)$^{49}$Ca.

H. Beer; C. Coceva; P. V. Sedyshev; Yu. P. Popov; H. Herndl; R. Hofinger; P. Mohr; H. Oberhummer

1996-08-07T23:59:59.000Z

87

Thermal performance of clean horizontal radiant barriers under winter conditions: Laboratory measurements and mathematical modeling  

Science Conference Proceedings (OSTI)

Several field experiments have been performed on attic radiant barriers under winter conditions; however, most of them have been confined to the fairly mild climates of Florida, Oklahoma, and Tennessee. Only one field experiment in a very cold climate (Canada) has been performed. In addition, no previous laboratory experiments under winter conditions have been performed on an attic both with and without a radiant barrier. This paper presents the results of laboratory measurements of the thermal performance of clean horizontal radiant barriers in a simulated residential attic module under nighttime or low solar gain daytime winter conditions. Comparing tests under the same conditions with and without a radiant barrier shows that the addition of a clean horizontal radiant barrier to insulation at the R-22 to R-25 level decreases the ceiling heat flow by 6 to 8%. The experimental results were found to be in very good agreement with predictions made with a mathematical model for the thermal performance of attics.

Wilkes, K.E.; Childs, P.W.

1992-01-01T23:59:59.000Z

88

Thermal performance of clean horizontal radiant barriers under winter conditions: Laboratory measurements and mathematical modeling  

Science Conference Proceedings (OSTI)

Several field experiments have been performed on attic radiant barriers under winter conditions; however, most of them have been confined to the fairly mild climates of Florida, Oklahoma, and Tennessee. Only one field experiment in a very cold climate (Canada) has been performed. In addition, no previous laboratory experiments under winter conditions have been performed on an attic both with and without a radiant barrier. This paper presents the results of laboratory measurements of the thermal performance of clean horizontal radiant barriers in a simulated residential attic module under nighttime or low solar gain daytime winter conditions. Comparing tests under the same conditions with and without a radiant barrier shows that the addition of a clean horizontal radiant barrier to insulation at the R-22 to R-25 level decreases the ceiling heat flow by 6 to 8%. The experimental results were found to be in very good agreement with predictions made with a mathematical model for the thermal performance of attics.

Wilkes, K.E.; Childs, P.W.

1992-08-01T23:59:59.000Z

89

Thermal neutron capture cross section of gadolinium by pile-oscillation measurements in MINERVE  

SciTech Connect

Natural gadolinium is used as a burnable poison in most LWR to account for the excess of reactivity of fresh fuels. For an accurate prediction of the cycle length, its nuclear data and especially its neutron capture cross section needs to be known with a high precision. Recent microscopic measurements at Rensselaer Polytechnic Inst. (RPI) suggest a 11% smaller value for the thermal capture cross section of {sup 157}Gd, compared with most of evaluated nuclear data libraries. To solve this inconsistency, we have analyzed several pile-oscillation experiments, performed in the MINERVE reactor. They consist in the measurement of the reactivity variation involved by the introduction in the reactor of small-samples, containing different mass amounts of natural gadolinium. The analysis of these experiments is done through the exact perturbation theory, using the PIMS calculation tool, in order to link the reactivity effect to the thermal capture cross section. The measurement of reactivity effects is used to deduce the 2200 m.s-1 capture cross section of {sup nat}Gd which is (49360 {+-} 790) b. This result is in good agreement with the JEFF3.1.1 value (48630 b), within 1.6% uncertainty at 1{sigma}, but is strongly inconsistent with the microscopic measurements at RPI which give (44200 {+-} 500) b. (authors)

Leconte, P.; Di-Salvo, J.; Antony, M.; Pepino, A. [CEA, DEN, DER, Cadarache, F-13108 Saint-Paul-Lez-Durance (France); Hentati, A. [International School in Nuclear Engineering, Cadarache, F-13108 Saint-Paul-Lez-Durance (France)

2012-07-01T23:59:59.000Z

90

Bottke et al.: Yarkovsky Effect and Asteroid Evolution 395 The Effect of Yarkovsky Thermal Forces on the Dynamical  

E-Print Network (OSTI)

Miroslav Broz Charles University, Prague The Yarkovsky effect is a thermal radiation force that causes states, shapes, and internal structures of the sur- viving bodies. The largest impact events are believed with short cosmic-ray- exposure (CR

Bottke, William F.

91

Measurement of effective thermal conductivity of wheat as a function of moisture content  

Science Conference Proceedings (OSTI)

Grain drying and storage are one of the main activities of agricultural industry. Increasing energy costs have stressed the importance of calculation of heat and mass transfer in a grain bulk in order to be able to optimize drying facilities. Another limitation during drying is the preservation of grain structure and its nutritional values, Muehlbauer and Christ have shown that damage to the grain structure and grain nutritional value is dependent upon grain temperature and drying time. Therefore, proper conditions during drying and storage of cereal grains require the knowledge of the thermophysical properties of the grains. The effective thermal conductivity of two varieties of Triticum durum wheat and a wheat product, bulgur, is determined at different moisture contents and at ambient temperature by the transient lime heat source method. The moisture contents of the samples ranged from 9.17 to 38.65% wet basis and the bulk densities ranged from 675 to 827 kg/m{sup 3}. Under those conditions, the measured effective thermal conductivities ranged from 0.159 to 0.201 W/m.K. The effective thermal conductivity is found to be linearly increasing with moisture content. The results are also in good agreement with literature values.

Tavman, S. [Ege Univ., Izmir (Turkey). Food Engineering Dept.] [Ege Univ., Izmir (Turkey). Food Engineering Dept.; Tavman, I.H. [Dokuz Eyluel Univ., Izmir (Turkey). Mechanical Engineering Dept.] [Dokuz Eyluel Univ., Izmir (Turkey). Mechanical Engineering Dept.

1998-07-01T23:59:59.000Z

92

A Theory for the Retrievals of Virtual Temperature from Remote Measurements of Horizontal Winds and Thermal Radiation  

Science Conference Proceedings (OSTI)

This paper develops a theory for the estimation of virtual temperature from remote measurements of (i) emitted thermal radiation by microwave and infrared radiometers and (ii) horizontal winds by Doppler radars (or lidars). The problem of ...

Tzvi Gal-Chen

1988-06-01T23:59:59.000Z

93

A compact and miniaturized high resolution capacitance dilatometer for measuring thermal expansion and magnetostriction  

SciTech Connect

We describe the design, construction, calibration, and two different applications of a miniature capacitance dilatometer. The device is suitable for thermal expansion and magnetostriction measurements from 300 K down to about 25 mK, with a resolution of 0.02 A at low temperatures. The main body of the dilatometer is fabricated from a single block of a Be-Cu alloy by electrical discharge milling. This creates an extremely compact high-resolution measuring cell. We have successfully tested and operated dilatometers of this new type with the commonly used physical property measurement system by quantum design, as well as with several other cryogenic refrigeration systems down to 25 mK and in magnetic fields up to 20 T. Here, the capacitance is measured with a commercially available capacitance bridge. Using a piezoelectric rotator from Attocube Systems, the cell can be rotated at T= 25 mK inside of an inner vacuum chamber of 40 mm diameter. The miniaturized design for the one-axis rotation setup allows a rotation of 360 Degree-Sign .

Kuechler, R.; Bauer, T.; Brando, M.; Steglich, F. [Max Planck Institute for Chemical Physics of Solids, Noethnitzer Str. 40, 01187 Dresden (Germany)

2012-09-15T23:59:59.000Z

94

The Characteristics and Evolution of Supercooled Water in Wintertime Storms over the Sierra Nevada: A Summary of Microwave Radiometric Measurements Taken during the Sierra Cooperative Pilot Project  

Science Conference Proceedings (OSTI)

A comprehensive examination of the evolution and vertical distribution of supercooled liquid water in Sierra Nevada winter storms was completed as part of the Sierra Cooperative Pilot Project. Measurements of supercooled water in 63 storms, which ...

Mark F. Heggli; Robert M. Rauber

1988-09-01T23:59:59.000Z

95

Experimental Development and Demonstration of Ultrasonic Measurement Diagnostics for Sodium Fast Reactor Thermal-hydraulics  

Science Conference Proceedings (OSTI)

This research project will address some of the principal technology issues related to sodium-cooled fast reactors (SFR), primarily the development and demonstration of ultrasonic measurement diagnostics linked to effective thermal convective sensing under normatl and off-normal conditions. Sodium is well-suited as a heat transfer medium for the SFR. However, because it is chemically reactive and optically opaque, it presents engineering accessibility constraints relative to operations and maintenance (O&M) and in-service inspection (ISI) technologies that are currently used for light water reactors. Thus, there are limited sensing options for conducting thermohydraulic measurements under normal conditions and off-normal events (maintenance, unanticipated events). Acoustic methods, primarily ultrasonics, are a key measurement technology with applications in non-destructive testing, component imaging, thermometry, and velocimetry. THis project would have yielded a better quantitative and qualitative understanding of the thermohydraulic condition of solium under varied flow conditions. THe scope of work will evaluate and demonstrate ultrasonic technologies and define instrumentation options for the SFR.

Tokuhiro, Akira; Jones, Byron

2013-09-13T23:59:59.000Z

96

Thermal Conductivity Measurement of Xe-Implanted Uranium Dioxide Thick Films using Multilayer Laser Flash Analysis  

SciTech Connect

The Fuel Cycle Research and Development program's Advanced Fuels campaign is currently pursuing use of ion beam assisted deposition to produce uranium dioxide thick films containing xenon in various morphologies. To date, this technique has provided materials of interest for validation of predictive fuel performance codes and to provide insight into the behavior of xenon and other fission gasses under extreme conditions. In addition to the structural data provided by such thick films, it may be possible to couple these materials with multilayer laser flash analysis in order to measure the impact of xenon on thermal transport in uranium dioxide. A number of substrate materials (single crystal silicon carbide, molybdenum, and quartz) containing uranium dioxide films ranging from one to eight microns in thickness were evaluated using multilayer laser flash analysis in order to provide recommendations on the most promising substrates and geometries for further investigation. In general, the uranium dioxide films grown to date using ion beam assisted deposition were all found too thin for accurate measurement. Of the substrates tested, molybdenum performed the best and looks to be the best candidate for further development. Results obtained within this study suggest that the technique does possess the necessary resolution for measurement of uranium dioxide thick films, provided the films are grown in excess of fifty microns. This requirement is congruent with the material needs when viewed from a fundamental standpoint, as this length scale of material is required to adequately sample grain boundaries and possible second phases present in ceramic nuclear fuel.

Nelson, Andrew T. [Los Alamos National Laboratory

2012-08-30T23:59:59.000Z

97

Evolution of Design Methodologies for Next Generation of Reactor Pressure Vessels and Extensive Role of Thermal-Hydraulic Numerical Tools  

SciTech Connect

The thermal-hydraulic design of the first pressurized water reactors was mainly based on an experimental approach, with a large series of tests on the main equipment [control rod guide tubes, reactor pressure vessel (RPV) plenums, etc.] to check performance.Development of computational fluid dynamics codes and computers now allows for complex simulations of hydraulics phenomena. Provided adequate qualification, these numerical tools are an efficient means to determine hydraulics in the given design and to perform sensitivities for optimization of new designs. Experiments always play their role, first for qualification and then for validation at the last stage of the design. The design of the European Pressurized Water Reactor (EPR), jointly developed by Framatome ANP, Electricite de France (EDF), and the German utilities, is based on both hydraulics calculations and experiments handled in a complementary approach.This paper describes the collective effort launched by Framatome ANP and EDF on hydraulics calculations for the RPV of the EPR. It concerns three-dimensional calculations of RPV inlets, including the cold legs, the RPV downcomer and lower plenum, and the RPV upper plenum up to and including the hot legs. It covers normal operating conditions but also accidental conditions such as pressurized thermal shock in a small-break loss-of-coolant accident. Those hydraulics studies have provided much useful information for the mechanical design of RPV internals.

Bellet, Serge [Electricite de France - Septen (EDF) (France); Goreaud, Nicolas [Framatome ANP(France); Nicaise, Norbert [Framatome ANP (France)

2005-11-15T23:59:59.000Z

98

Evolution of the design methodologies for the next generation of RPV Extensive role of the thermal-hydraulics numerical tools  

SciTech Connect

The thermal-hydraulic design of the first PWR's was mainly based on an experimental approach, with a large series of test on the main equipment (control rod guide tubes, RPV plenums..), to check its performances. Development of CFD-codes and computers now allows for complex simulations of hydraulic phenomena. Provided adequate qualification, these numerical tools are efficient means to determine hydraulics in given design, and to perform sensitivities for optimization of new designs. Experiments always play their role, first for qualification, and for validation at the last stage of the design. The design of the European Pressurized water Reactor (EPR), is based on both hydraulic calculations and experiments, handled in a complementary approach. This paper describes the effort launched by Framatome-ANP on hydraulic calculations for the Reactor Pressure Vessel (RPV) of the EPR reactor. It concerns 3D-calculations of RPV-inlet including cold legs, RPV-downcomer and lower plenum, RPV-upper plenum up to and including hot legs. It covers normal operating conditions, but also accidental conditions as PTS (Pressurized Thermal Shock) in small break loss of coolant accident (SB-LOCA). Those hydraulic studies have provided numerous useful information for the mechanical design of RPV-internals. (authors)

Goreaud, Nicolas; Nicaise, Norbert [Framatome ANP, Tour Areva 92 084 Paris La Defense (France); Stoudt, Roger [Framatome ANP, 3315 Old forest road, Lynchburg, VA 24501 (United States)

2004-07-01T23:59:59.000Z

99

High-resolution thermal expansion measurements under helium-gas pressure  

Science Conference Proceedings (OSTI)

We report on the realization of a capacitive dilatometer, designed for high-resolution measurements of length changes of a material for temperatures 1.4 K Less-Than-Or-Slanted-Equal-To T Less-Than-Or-Slanted-Equal-To 300 K and hydrostatic pressure P Less-Than-Or-Slanted-Equal-To 250 MPa. Helium ({sup 4}He) is used as a pressure-transmitting medium, ensuring hydrostatic-pressure conditions. Special emphasis has been given to guarantee, to a good approximation, constant-pressure conditions during temperature sweeps. The performance of the dilatometer is demonstrated by measurements of the coefficient of thermal expansion at pressures P Asymptotically-Equal-To 0.1 MPa (ambient pressure) and 104 MPa on a single crystal of azurite, Cu{sub 3}(CO{sub 3}){sub 2}(OH){sub 2}, a quasi-one-dimensional spin S = 1/2 Heisenberg antiferromagnet. The results indicate a strong effect of pressure on the magnetic interactions in this system.

Manna, Rudra Sekhar; Wolf, Bernd; Souza, Mariano de; Lang, Michael [Physics Institute, Goethe University Frankfurt(M), SFB/TR49, D-60438 Frankfurt am Main (Germany)

2012-08-15T23:59:59.000Z

100

MONITORING POWER PLANT EFFICIENCY USING THE MICROWAVE-EXCITED THERMAL-ACOUSTIC EFFECT TO MEASURE UNBURNED CARBON  

Science Conference Proceedings (OSTI)

The objective of this project is to explore microwave-excited thermal-acoustic (META) phenomena for quantitative analysis of granular and powdered materials, with the culmination of the research to be an on-line carbon-in-ash monitor for coal-fired power plants. This technique of analyzing unburned carbon in fly ash could be a less tedious and time consuming method as compared to the traditional LOI manual procedure. Phase 1 of the research focused on off-line single-frequency thermal-acoustic measurements where an off-line fly ash monitor was constructed that could operate as analytical tool to explore instrument and methodology parameters for quantifying the microwave-excited thermal-acoustic effect of carbon in fly ash, and it was determined that the off-line thermal-acoustic technique could predict the carbon content of a random collection of fly ashes with a linear correlation constant of R{sup 2} = 0.778. Much higher correlations are expected for fly ashes generated from a single boiler. Phase 2 of the research developing a methodology to generate microwave spectra of various powders, including fly ash, coal, and inorganic minerals, and to determine if these microwave spectra could be used for chemical analyses. Although different minerals produced different responses, higher resolution microwave spectra would be required to be able to distinguish among minerals. Phase 3 of the research focused on the development of an on-line fly ash monitor that could be adapted to measure either a thermal-acoustic or thermal-elastic response to due microwave excitation of fly ash. The thermal-acoustic response was successfully employed for this purpose but the thermal-elastic response was too weak to yield a useful on-line device.

Robert C. Brown; Robert J. Weber; Jeffrey J. Swetelitsch

2005-01-01T23:59:59.000Z

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


101

Ground truth measurements plan for the Multispectral Thermal Imager (MTI) satellite  

SciTech Connect

Sandia National Laboratories (SNL), Los Alamos National Laboratory (LANL), and the Savannah River Technology Center (SRTC) have developed a diverse group of algorithms for processing and analyzing the data that will be collected by the Multispectral Thermal Imager (MTI) after launch late in 1999. Each of these algorithms must be verified by comparison to independent surface and atmospheric measurements. SRTC has selected 13 sites in the continental U.S. for ground truth data collections. These sites include a high altitude cold water target (Crater Lake), cooling lakes and towers in the warm, humid southeastern US, Department of Energy (DOE) climate research sites, the NASA Stennis satellite Validation and Verification (V and V) target array, waste sites at the Savannah River Site, mining sites in the Four Corners area and dry lake beds in the southwestern US. SRTC has established mutually beneficial relationships with the organizations that manage these sites to make use of their operating and research data and to install additional instrumentation needed for MTI algorithm V and V.

Garrett, A.J.

2000-01-03T23:59:59.000Z

102

STEPA Temperature Profiler for Measuring the Oceanic Thermal Boundary Layer at the OceanAir Interface  

Science Conference Proceedings (OSTI)

A fast measuring system has been designed and built to determine the oceanic thermal microstructure at the oceanair interface. The system consists of a profiler sonde, which amends through the uppermost few meters of the ocean with a time of ...

Theodor C. Mammen; Nikolaus von Bosse

1990-04-01T23:59:59.000Z

103

Shocked H2O ice: Thermal emission measurements and the criteria for phase changes during impact events  

E-Print Network (OSTI)

Shocked H2O ice: Thermal emission measurements and the criteria for phase changes during impact/s will initiate phase changes on icy surfaces. Thus, shock-induced melting and vaporization of ice is a widespread from shocked H2O ice and derive peak and post-shock temperatures. Under shock pressures between 8

Stewart, Sarah T.

104

Thermal evolution of the full three-dimensional magnetic excitations in the multiferroic BiFeO3  

SciTech Connect

We present neutron inelastic scattering measurements of the full three-dimensional spin-wave dispersion in the multiferroic material BiFeO3 for temperatures from 5K to 700K. Despite the presence of strong electromagnetic coupling, the magnetic excitations behave like conventional magnons over all parts of the Brillouin zone. At low temperature the spin-waves are well-defined coherent modes, described by a classical model for a G-type antiferromagnet. A softening of the spin-wave velocity and broadening in energy is already present at room temperature, which is well below the N eel temperature TN 640K, and increases on heating. In addition, a strong hybridization of the Fe 3d and O 2p states is found to modify the distribution of the spin-wave spectral weight significantly, which implies that the spins are not restricted to the Fe atomic sites as previously believed.

Xu, Zhijun [ORNL; Wen, Jinsheng [University of California, Berkeley; Berlijn, Tom [ORNL; Gehring, Peter M [ORNL; Stock, Christopher K [ORNL; Stone, Matthew B [ORNL; Gu, G. D. [Brookhaven National Laboratory (BNL); Shapiro, S. M. [Brookhaven National Laboratory (BNL); Birgeneau, R J [University of California, Berkeley & LBNL; Xu, Guangyong [Brookhaven National Laboratory (BNL)

2012-01-01T23:59:59.000Z

105

Photoacoustic Thermal Characterization of a Natural Biofoam ...  

Science Conference Proceedings (OSTI)

... thermal properties that permit its use as an effective insulation material. ... Evolution of Crystallographic Texture of Cold Roll Bonding and Annealing Ti-Al- Nb Multilayer Sheets ... Thermodynamic Measurement of CaO-P2O5-SiO2 System.

106

Measurement of single and double glazing thermal performance under realistic conditions using the mobile window thermal test (MoWiTT) facility  

SciTech Connect

The thermal performance of single glazing, clear double glazing, and double glazing with a low-emissivity coating was measured in both south-facing and north-facing orientations under realistic field conditions using the new MoWiTT field test facility. The time-dependent net heat flow through each fenestration was found to be consistent with the predictions of the standard simplified heat transfer model, provided that an angle-dependent shading coefficient is used and diffuse solar gain is included in the calculation. Summer-condition average U-values were derived for each glazing type and were found to agree with the expected values for both types of double glazing. The measured U-value for single glazing was lower than predicted.

Klems, J.; Keller, H.

1986-11-01T23:59:59.000Z

107

Measuring Feedback Using the Intergalactic Medium State and Evolution Inferred from the Soft X-ray Background  

E-Print Network (OSTI)

We explore the intergalactic medium (IGM) as a potential source of the unresolved soft X-ray background (XRB) and the feasibility to extract the IGM state and evolution from XRB observations. We build two analytical models, the continuum field model and the halo model, to calculate the IGM XRB mean flux, angular auto correlation and cross correlation with galaxies. Our results suggest that the IGM may contribute a significant fraction to the unresolved soft XRB flux and correlations. We calibrated non-Gaussian errors estimated against our $512^3$ moving mesh hydro simulation and estimate that the ROSAT all sky survey plus Sloan galaxy photometric redshift survey would allow a $\\sim 10%$ accuracy in the IGM XRB-galaxy cross correlation power spectrum measurement for $800small scales, non-gravitational heating, e.g. feedback, dominates over gravity and leaves unique signatures in the IGM XRB, which allows a comparable accuracy in the measurement of the amount of non-gravitational heating and the length scales where non-gravitational energy balances gravity.

Pengjie Zhang; Ue-Li Pen

2002-02-06T23:59:59.000Z

108

Evolution of the Sensor Fish Device for Measuring Physical Conditions in Severe Hydraulic Environments  

DOE Green Energy (OSTI)

To assist in deriving biological specifications for design of turbine rehabilitation measures, new ''fish-friendly'' turbines, and spillway designs and operations, scientists at the Pacific Northwest National Laboratory (PNNL) have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. The Sensor Fish was developed with the support of the U.S. Department of Energy's Advanced Hydropower Turbine System program. Field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

Carlson, Thomas J.; Duncan, Joanne P.

2003-02-28T23:59:59.000Z

109

Thermal imaging measurement of lateral diffusivity and non-invasive material defect detection  

DOE Patents (OSTI)

A system and method for determining lateral thermal diffusivity of a material sample using a heat pulse; a sample oriented within an orthogonal coordinate system; an infrared camera; and a computer that has a digital frame grabber, and data acquisition and processing software. The mathematical model used within the data processing software is capable of determining the lateral thermal diffusivity of a sample of finite boundaries. The system and method may also be used as a nondestructive method for detecting and locating cracks within the material sample.

Sun, Jiangang (Westmont, IL); Deemer, Chris (Downers Grove, IL)

2003-01-01T23:59:59.000Z

110

Heat transfer simulation and thermal measurements of microfabricated x-ray transparent heater stages  

SciTech Connect

A microfabricated amorphous silicon nitride membrane-based nanocalorimeter is proposed to be suitable for an x-ray transparent sample platform with low power heating and built-in temperature sensing. In this work, thermal characterization in both air and vacuum are analyzed experimentally and via simulation. Infrared microscopy and thermoreflectance microscopy are used for thermal imaging of the sample area in air. While a reasonably large isothermal area is found on the sample area, the temperature homogeneity of the entire sample area is low, limiting use of the device as a heater stage in air or other gases. A simulation model that includes conduction, as well as radiation and convection heat loss, is presented with radiation and convection parameters determined experimentally. Simulated temperature distributions show that the homogeneity can be improved by using a thicker thermal conduction layer or reducing the pressure of the gas in the environment but neither are good solutions for the proposed use. A new simple design that has improved temperature homogeneity and a larger isothermal area while maintaining a thin thermal conduction layer is proposed and fabricated. This new design enables applications in transmission x-ray microscopes and spectroscopy setups at atmospheric pressure.

Baldasseroni, C. [Department of Materials Science and Engineering, University of California Berkeley, Berkeley, California 94720 (United States); Queen, D. R.; Cooke, David W.; Hellman, F. [Department of Physics, University of California Berkeley, Berkeley, California 94720 (United States); Maize, K.; Shakouri, A. [Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064 (United States)

2011-09-15T23:59:59.000Z

111

Modified Fowler-Milne method for the spectroscopic determination of thermal plasma temperature without the measurement of continuum radiation  

Science Conference Proceedings (OSTI)

A technique based on the Fowler-Milne method for the spectroscopic determination of thermal plasma temperatures without measuring continuum radiation is presented. This technique avoids the influence of continuum radiation with the combined line and continuum emission coefficients to derive the plasma temperatures. The amount of continuum emission coefficient is estimated by using an expression related to the Biberman factors. Parameters that affect the accuracy of the proposed technique and errors in the measured plasma temperatures are analyzed. It is shown that, by using the Ar I 696.5 nm line with a bandwidth of 3.27 nm without taking into account the continuum radiation, the plasma temperature measured will be lower on the order of up to 1000-3000 K for temperatures from 20 000 to 24 000 K. The theoretically predicted temperature errors are in good agreement with the experimental results, indicating that the proposed technique is reliable for plasma temperature measurement.

Ma Shuiliang [State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001 (China); Plasma Research Laboratory, Australian National University, Canberra ACT 0200 (Australia); Gao Hongming; Wu Lin [State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001 (China)

2011-01-15T23:59:59.000Z

112

Measurement of the Equivalent Thermal Resistance of Rooftop Lawns in a Hot-Climate Wind Tunnel  

E-Print Network (OSTI)

In a very hot summer equivalent to a Guangzhou summer, the reduction of heat coming into rooms is very important with respect to thermal comfort and energy efficiency. The objective of this study is to investigate the evaporation cooling effect on a rooftop lawn. A hot-climate wind tunnel experiment was carried out in order to obtain and analyze the heat and moisture transport in the rooftop lawn. Furthermore, a calculation with the energy conservation equation was carried out using the results of the hot-climate wind tunnel experiment. The calculated equivalent thermal resistance and synthesis exterior surface heat transfer coefficient were in fairly good agreement with that in the design standard for energy efficiency of residential buildings in the hot summer and warm winter zone, while the average velocity in hot-climate wind tunnel equals the summer average outdoor velocity in Guangzhou.

Meng, Q.; Zhang, Y.; Zhang, L.

2006-01-01T23:59:59.000Z

113

The Development of Thermals from Rest  

Science Conference Proceedings (OSTI)

Conventional techniques for releasing a thermal in laboratory experiments induce enough initial motion to affect seriously the thermal's subsequent evolution. We have invented a mechanism for releasing thermals from very close to a state of rest. ...

Odn Snchez; David J. Raymond; Larry Libersky; Albert G. Petschek

1989-07-01T23:59:59.000Z

114

Considerations and measurements of latent-heat-storage salts for secondary thermal battery applications  

Science Conference Proceedings (OSTI)

Given its potential benefits, the practicality of using a latent heat-storage material as the basis for a passive thermal management system is being assessed by Chloride Silent Power Ltd. (CSPL) with technical assistance from Beta Power, Inc. and Sandia National Laboratories (SNL). Based on the experience gained in large-scale solar energy storage programs, fused salts were selected as the primary candidates for the heat-storage material. The initial phase of this assessment was directed to an EV battery being designed at CSPL for the ETX-II program. Specific tasks included the identification and characterization of potential fused salts, a determination of placement options for the salts within the battery, and an assessment of the ultimate benefit to the battery system. The results obtained to date for each of these tasks are presented in this paper.

Koenig, A.A.; Braithwaite, J.W.; Armijo, J.R.

1988-05-16T23:59:59.000Z

115

Uncertainty analysis routine for the Ocean Thermal Energy Conversion (OTEC) biofouling measurement device and data reduction procedure. [HTCOEF code  

DOE Green Energy (OSTI)

Biofouling and corrosion of heat exchanger surfaces in Ocean Thermal Energy Conversion (OTEC) systems may be controlling factors in the potential success of the OTEC concept. Very little is known about the nature and behavior of marine fouling films at sites potentially suitable for OTEC power plants. To facilitate the acquisition of needed data, a biofouling measurement device developed by Professor J. G. Fetkovich and his associates at Carnegie-Mellon University (CMU) has been mass produced for use by several organizations in experiments at a variety of ocean sites. The CMU device is designed to detect small changes in thermal resistance associated with the formation of marine microfouling films. An account of the work performed at the Pacific Northwest Laboratory (PNL) to develop a computerized uncertainty analysis for estimating experimental uncertainties of results obtained with the CMU biofouling measurement device and data reduction scheme is presented. The analysis program was written as a subroutine to the CMU data reduction code and provides an alternative to the CMU procedure for estimating experimental errors. The PNL code was used to analyze sample data sets taken at Keahole Point, Hawaii; St. Croix, the Virgin Islands; and at a site in the Gulf of Mexico. The uncertainties of the experimental results were found to vary considerably with the conditions under which the data were taken. For example, uncertainties of fouling factors (where fouling factor is defined as the thermal resistance of the biofouling layer) estimated from data taken on a submerged buoy at Keahole Point, Hawaii were found to be consistently within 0.00006 hr-ft/sup 2/-/sup 0/F/Btu, while corresponding values for data taken on a tugboat in the Gulf of Mexico ranged up to 0.0010 hr-ft/sup 2/-/sup 0/F/Btu. Reasons for these differences are discussed.

Bird, S.P.

1978-03-01T23:59:59.000Z

116

Determination of thermal parameters of one-dimensional nanostructures through a thermal transient method  

E-Print Network (OSTI)

of heat capacity and thermal conductivity measurements bythe heat pulse method for thermal transport measurements ofG. Speci?c heat and thermal conductivity measurements on

Arriagada, A.; Yu, E. T.; Bandaru, P. R.

2009-01-01T23:59:59.000Z

117

High temperature thermal conductivity measurements of UO/sub 2/ by Direct Electrical Heating. Final report. [MANTRA-III  

SciTech Connect

High temperature properties of reactor type UO/sub 2/ pellets were measured using a Direct Electrical Heating (DEH) Facility. Modifications to the experimental apparatus have been made so that successful and reproducible DEH runs may be carried out while protecting the pellets from oxidation at high temperature. X-ray diffraction measurements on the UO/sub 2/ pellets have been made before and after runs to assure that sample oxidation has not occurred. A computer code has been developed that will model the experiment using equations that describe physical properties of the material. This code allows these equations to be checked by comparing the model results to collected data. The thermal conductivity equation for UO/sub 2/ proposed by Weilbacher has been used for this analysis. By adjusting the empirical parameters in Weilbacher's equation, experimental data can be matched by the code. From the several runs analyzed, the resulting thermal conductivity equation is lambda = 1/4.79 + 0.0247T/ + 1.06 x 10/sup -3/ exp(-1.62/kT/) - 4410. exp(-3.71/kT/) where lambda is in w/cm K, k is the Boltzman constant, and T is the temperature in Kelvin.

Bassett, B

1980-10-01T23:59:59.000Z

118

Solar and Thermal Radiation Errors on Upper-Air Radiosonde Temperature Measurements  

Science Conference Proceedings (OSTI)

Atmospheric temperature and humidity profiles are important for weather prediction, but climate change has increased the interest in upper-air observations asking for very high quality reference measurements. Here we show an experimental approach ...

R. Philipona; A. Kruchi; G. Romanens; G. Levrat; P. Ruppert; E. Brocard; P. Jeannet; D. Ruffieux; B. Calpini

119

Characterization of Thermal Effects in Pyranometers: A Data Correction Algorithm for Improved Measurement of Surface Insolation  

Science Conference Proceedings (OSTI)

Pyranometers are reliable, economical radiometers commonly used to measure solar irradiances at the surface in a long-term, monitoring mode. This paper presents a discussion of the response of these instruments to varying environmental conditions,...

Brett C. Bush; Francisco P. J. Valero; A. Sabrina Simpson; Lionel Bignone

2000-02-01T23:59:59.000Z

120

Solar and Thermal Radiation Errors on Upper-Air Radiosonde Temperature Measurements  

Science Conference Proceedings (OSTI)

Atmospheric temperature and humidity profiles are important for weather prediction, but climate change has increased the interest in upper-air observations asking for very high-quality reference measurements. This paper discusses an experimental ...

R. Philipona; A. Kruchi; G. Romanens; G. Levrat; P. Ruppert; E. Brocard; P. Jeannet; D. Ruffieux; B. Calpini

2013-10-01T23:59:59.000Z

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


121

Measurements of Carbonaceous Aerosols using Semi-Continuous Thermal-Optical Method  

Science Conference Proceedings (OSTI)

Carbonaceous aerosols are major components in air pollution as a result of energy consumption, thus measurement of them is important to waste management. Increasing interest has been drawn to the identification, measurement, analysis, and modeling of carbon aerosols in the past decade. This book chapter will provide a review of current state-of-art techniques to determine carbonaceous aerosols in relation to air pollution and waste management. The chapter will be composed of four parts. The introduction will discuss why carbon aerosols including elemental carbon (EC), organic carbon (OC), and total carbon (TC=EC+OC) are important to energy consumption, air pollution, waste management, and global climate change. Key definitions will be introduced. Relevant terminologies will be provided. The second part will be a review of the current state-of the art measurement techniques that are used to determine carbon aerosols. Both on-line and off-line methods will be described. Comparisons of different techniques that provide the same physical quantity will be provided based on recent literature findings. Differences among the physical parameters determined by various techniques will be discussed. The third part will focus on data analysis and products obtained from carbon aerosol measurements. In addition to EC, OC, and TC, primary organic carbon (POC) and secondary organic carbon (SOC) are of interest to researchers to understand the source and sink of carbonaceous aerosols. Techniques used to determine POC and SOC, such as the EC tracer method and positive matrix factorization, will be described and their differences discussed. Examples will be provided showing field data comparison between the Sunset organic carbon and elemental carbon field analyzer and the Aerodyne aerosol mass spectrometer, both of which are widely used for on-line aerosol measurements. The last part will report new trends and summarize future research needs in carbon aerosol measurement. Emerging problems will be identified and research priorities will be recommended.

Yu, Xiao-Ying

2011-08-01T23:59:59.000Z

122

Representative Air Temperature of Thermally Heterogeneous Urban Areas Using the Measured Pressure Gradient  

Science Conference Proceedings (OSTI)

A method to measure an area-averaged ground air temperature based on the hydrostatic equation is shown. The method was devised to overcome the problem of finding the most representative surface air temperature over a wide region, a problem that ...

Hirofumi Sugawara; Ken-ichi Narita; Takehiko Mikami

2004-08-01T23:59:59.000Z

123

A Thermal Device for Aircraft Measurement of the Solid Water Content of Clouds  

Science Conference Proceedings (OSTI)

A constant temperature probe for the measurement of solid water content of clouds is described. The probe is operated at a temperature of approximately 25C, and is designed to collect and melt ice particles that impact in an open half-cylinder, ...

W. D. King; D. E. Turvey

1986-09-01T23:59:59.000Z

124

Research options for the development of sensors to measure the thermal state of solid steel bodies.  

SciTech Connect

The purpose of the study reported here is to assist Battelle's Pcacific Northwest Laboratory (PNL) in planning a research and development program to develop temperature sensors for metal and ceramic industries. This study focuses on sensors to measure internal temperatures within bodies of hot steel. A series of literature surveys, interviews, field visits, and meetings with steel-industry organizations was conducted in seeking answers to questions posed by PNL. These questions, with responses, are summarized.

Gaspar, T.A.; Lownie, H.W. Jr.

1983-02-01T23:59:59.000Z

125

Least squares support vector machines with tuning based on chaotic differential evolution approach applied to the identification of a thermal process  

Science Conference Proceedings (OSTI)

In the past decade, support vector machines (SVMs) have gained the attention of many researchers. SVMs are non-parametric supervised learning schemes that rely on statistical learning theory which enables learning machines to generalize well to unseen ... Keywords: Chaotic differential evolution, Identification, Least squares support vector machines

Glauber Souto dos Santos; Luiz Guilherme Justi Luvizotto; Viviana Cocco Mariani; Leandro dos Santos Coelho

2012-04-01T23:59:59.000Z

126

Isotopic yield measurement in the heavy mass region for {sup 239}Pu thermal neutron induced fission  

SciTech Connect

Despite the huge number of fission yield data available in the different evaluated nuclear data libraries, such as JEFF-3.1.1, ENDF/B-VII.0, and JENDL-4.0, more accurate data are still needed both for nuclear energy applications and for our understanding of the fission process itself. It is within the framework of this that measurements on the recoil mass spectrometer Lohengrin (at the Institut Laue-Langevin, Grenoble, France) was undertaken, to determine isotopic yields for the heavy fission products from the {sup 239}Pu(n{sub th},f) reaction. In order to do this, a new experimental method based on {gamma}-ray spectrometry was developed and validated by comparing our results with those performed in the light mass region with completely different setups. Hence, about 65 fission product yields were measured with an uncertainty that has been reduced on average by a factor of 2 compared to that previously available in the nuclear data libraries. In addition, for some fission products, a strongly deformed ionic charge distribution compared to a normal Gaussian shape was found, which was interpreted as being caused by the presence of a nanosecond isomeric state. Finally, a nuclear charge polarization has been observed in agreement, with the one described on other close fissioning systems.

Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Koester, U.; Faust, H.; Letourneau, A.; Panebianco, S. [CEA, DEN-Cadarache, F-13108 Saint-Paul-lez-Durance (France); Institut Laue Langevin, 6 rue Jules Horowitz, B.P. 156, F-38042, Grenoble (France); CEA, DSM-Saclay, IRFU/SPhN, F-91191 Gif-sur-Yvette (France)

2011-09-15T23:59:59.000Z

127

Measuring the Optical Performance of Evacuated Receivers via an Outdoor Thermal Transient Test: Preprint  

DOE Green Energy (OSTI)

Modern parabolic trough solar collectors operated at high temperatures to provide the heat input to Rankine steam power cycles employ evacuated receiver tubes along the collector focal line. High performance is achieved via the use of a selective surface with a high absorptance for incoming short-wave solar radiation and a low emittance for outgoing long-wave infrared radiation, as well as the use of a hard vacuum to essentially eliminate convective and conductive heat losses. This paper describes a new method that determines receiver overall optical efficiency by exposing a fluid-filled, pre-cooled receiver to one sun outdoors and measuring the slope of the temperature curve at the point where the receiver temperature passes the glass envelope temperature (that is, the point at which there is no heat gain or loss from the absorber). This transient test method offers the potential advantages of simplicity, high accuracy, and the use of the actual solar spectrum.

Kutscher, C.; Burkholder, F.; Netter, J.

2011-08-01T23:59:59.000Z

128

Improved 3-omega measurement of thermal conductivity in liquid, gases, and powders using a metal-coated optical fiber  

Science Conference Proceedings (OSTI)

A novel 3?thermal conductivitymeasurement technique called metal-coated 3? is introduced for use with liquids

Scott N. Schiffres; Jonathan A. Malen

2011-01-01T23:59:59.000Z

129

Measurement of plutonium and americium volatilities under thermal process conditions. Final report  

Science Conference Proceedings (OSTI)

We have used the transpiration method to measure volatilities of Pu and Am from PuO{sub 2}(s) and PuO{sub 2}/2% AmO{sub 2}(s) in the presence of steam and oxygen at temperatures of 1230--1430 K. We find the volatile species to be PuO{sub 2}(OH){sub 2}(g) and AmO{sub 2}(OH){sub 2}(g) at vapor pressures on the order of 10{sup {minus}10} atm and 10 {sup {minus}12} atm respectively under measurement conditions. For the Pu volatilization reaction, PuO{sub 2}(s) + 1/2 0{sub 2}(9) + H{sub 2}0(g) = PuO{sub 2}(OH){sub 2}(g), we obtain a free energy of reaction of {Delta}G{sup O}{sub T} = 231.3--0.0109 T in kj/mol, and for the Am volatilization reaction, AmO{sub 2}(s.s. in PuO{sub 2}) + 1/2 0{sub 2}(9) + H{sub 2}0(g) = AmO{sub 2}(OH){sub 2}(g), we obtain AG{sup O}{sub T} = 223.9--0.0109 T in kj/mol. We apply these results to the Rocky Flats Plant Fluidized Bed Incinerator to assess the amount of volatile Pu and Am produced in the secondary combustor chamber. Taking operating conditions of 550C combustor temperature, 40 kmols/h of total gas flow at 1 atm pressure, 0.1 atm 0{sub 2}(9), 0.05 atm H{sub 2}0(g), PuO{sub 2} (s) containing 200 ppm AmO{sub 2} in the bed, and 6000 h of operating time per year, gives volatilization rates of 7 {times} 10 {sup {minus}6}g Pu and 4 {times} 10 {sup {minus}9}g Am/y.

Krikorian, O.H.; Condit, R.H.; Fontes, A.S. Jr.; Fleming, D.L.; Magana, J.W.; Morris, W.F.; Adamson, M.G.

1993-04-28T23:59:59.000Z

130

Induced-polarization measurements at Roosevelt Hot Springs Thermal area, Utah  

DOE Green Energy (OSTI)

An induced polarization survey was conducted at Roosevelt Hot Springs, using the dipole-dipole array. The survey consisted of two profile lines, one across the southern end of the system (2200N) and another across the northern portion (5950N). A total of 15 line-km of profiles was run, with 100 m and 300 m dipoles out to n spacings of 4 to 6. Apparent resistivity amplitude and phase data were gathered with a phase-sensitive receiver at frequencies between 32 Hz and 1/256 Hz. The data are presented in the form of apparent resistivity of phase pseudosections. Induced polarization effects in geothermal environments can result from clays and pyrite which are associated with hydrothermal alteration. Laboratory measurements on altered material show some induced polarization effects at frequencies below 1 Hz which are thought to be due to pyrite. A higher frequency polarization (> 1 Hz) is attributed to the effects of clays. The primary purpose of this survey was to investigate the feasibility of mapping clay alteration zones, and separating them from other conductive features, by making use of their polarization characteristics. The field data show some small, low frequency phase anomalies which may be the result of pyrite deposition. The higher frequencies show considerable phase effects, which can be the result of clays, but the effects of electromagnetic coupling have not, as yet, been assessed.

Chu, J.J.; Sill, W.R.; Ward, S.H.

1979-06-01T23:59:59.000Z

131

Thermal conductivity of thermal-battery insulations  

DOE Green Energy (OSTI)

The thermal conductivities of a variety of insulating materials used in thermal batteries were measured in atmospheres of argon and helium using several techniques. (Helium was used to simulate the hydrogen atmosphere that results when a Li(Si)/FeS{sub 2} thermal battery ages.) The guarded-hot-plate method was used with the Min-K insulation because of its extremely low thermal conductivity. For comparison purposes, the thermal conductivity of the Min-K insulating board was also measured using the hot-probe method. The thermal-comparator method was used for the rigid Fiberfrax board and Fiberfrax paper. The thermal conductivity of the paper was measured under several levels of compression to simulate the conditions of the insulating wrap used on the stack in a thermal battery. The results of preliminary thermal-characterization tests with several silica aerogel materials are also presented.

Guidotti, R.A.; Moss, M.

1995-08-01T23:59:59.000Z

132

Activation Measurements for Thermal Neutrons, U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki; and Measurement of 63 Ni in Copper Samples From Hiroshima by Accelerator Mass Spectrometry  

SciTech Connect

The present paper presents the {sup 36}Cl measurement effort in the US. A large number of {sup 36}Cl measurements have been made in both granite and concrete samples obtained from various locations and distances in Hiroshima and Nagasaki. These measurements employed accelerator mass spectrometry (AMS) to quantify the number of atoms of {sup 36}Cl per atom of total Cl in the sample. Results from these measurements are presented here and discussed in the context of the DS02 dosimetry reevaluation effort for Hiroshima and Nagasaki atomic-bomb survivors. The production of {sup 36}Cl by bomb neutrons in mineral samples from Hiroshima and Nagasaki was primarily via the reaction {sup 35}Cl(n,{gamma}){sup 36}Cl. This reaction has a substantial thermal neutron cross-section (43.6 b at 0.025 eV) and the product has a long half-life (301,000 y). hence, it is well suited for neutron-activation detection in Hiroshima and Nagasaki using AMS more than 50 years after the bombings. A less important reaction for bomb neutrons, {sup 39}K(n,{alpha}){sup 36}Cl, typically produces less than 10% of the {sup 36}Cl in mineral samples such as granite and concrete, which contain {approx} 2% potassium. In 1988, only a year after the publication of the DS86 final report (Roesch 1987), it was demonstrated experimentally that {sup 36}Cl measured using AMS should be able to detect the thermal neutron fluences at the large distances most relevant to the A-bomb survivor dosimetry. Subsequent measurements in mineral samples from both Hiroshima and Nagasaki validated the experimental findings. The potential utility of {sup 36}Cl as a thermal neutron detector in Hiroshima was first presented by Haberstock et al. who employed the Munich AMS facility to measure {sup 36}Cl/Cl ratios in a gravestone from near the hypocenter. That work subsequently resulted in an expanded {sup 36}Cl effort in Germany that paralleled the US work. More recently, there have also been {sup 36}Cl measurements made by a Japanese group. The impetus for the extensive {sup 36}Cl and other neutron activation measurements was the recognized need to validate the neutron component of the dose in Hiroshima. Although this was suggested at the time of the DS86 Final Report, where it was stated that the calculated neutron doses for survivors could possibly be wrong, the paucity of neutron validation measurements available at that time prevented adequate resolution of this matter. It was not until additional measurements and data evaluations were made that it became clear that more work was required to better understand the discrepancies observed for thermal neutrons in Hiroshima. This resulted in a large number of additional neutron activation measurements in Hiroshima and Nagasaki by scientists in the US, Japan, and Germany. The results presented here for {sup 36}Cl, together with measurements made by other scientists and for other isotopes, now provide a much improved measurement basis for the validation of neutrons in Hiroshima.

Tore Straume; Alfredo A. Marchetti; Stephen D. Egbert; James A. Roberts; Ping Men; Shoichiro Fujita; Kiyoshi Shizuma; Masaharu Hoshi; G. Rugel; W. Ruhm; G. Korschinek; J. E. McAninch; K. L. Carroll; T. Faestermann; K. Knie; R. E. Martinelli; A. Wallner; C. Wallner

2005-01-14T23:59:59.000Z

133

Measurement of probe displacement to the thermal resolution limit in photonic force microscopy using a miniature quadrant photodetector  

Science Conference Proceedings (OSTI)

A photonic force microscope comprises of an optically trapped micro-probe and a position detection system to track the motion of the probe. Signal collection for motion detection is often carried out using the backscattered light off the probe-however, this mode has problems of low S/N due to the small backscattering cross sections of the micro-probes typically used. The position sensors often used in these cases are quadrant photodetectors. To ensure maximum sensitivity of such detectors, it would help if the detector size matched with the detection beam radius after the condenser lens (which for backscattered detection would be the trapping objective itself). To suit this condition, we have used a miniature displacement sensor whose dimensions makes it ideal to work with 1:1 images of micrometer-sized trapped probes in the backscattering detection mode. The detector is based on the quadrant photo-integrated chip in the optical pick-up head of a compact disc player. Using this detector, we measured absolute displacements of an optically trapped 1.1 {mu}m probe with a resolution of {approx}10 nm for a bandwidth of 10 Hz at 95% significance without any sample or laser stabilization. We characterized our optical trap for different sized probes by measuring the power spectrum for each probe to 1% accuracy, and found that for 1.1 {mu}m diameter probes, the noise in our position measurement matched the thermal resolution limit for averaging times up to 10 ms. We also achieved a linear response range of around 385 nm with cross talk between axes {approx_equal}4% for 1.1 {mu}m diameter probes. The detector has extremely high bandwidth (few MHz) and low optical power threshold-other factors that can lead to its widespread use in photonic force microscopy.

Pal, Sambit Bikas; Haldar, Arijit; Roy, Basudev; Banerjee, Ayan [Department of Physical Sciences, IISER-Kolkata, West Bengal 741252 (India)

2012-02-15T23:59:59.000Z

134

thermal_resistance_measurements  

Science Conference Proceedings (OSTI)

... "The NBS Line-Heat-Source Guarded Hot Plate for Thick Materials",FJ Powell and BG Rennex, Proceedings ASHRAE/DOE Conference - II, Atlanta ...

2013-12-16T23:59:59.000Z

135

Correlation Between Thermal Conductivity and Microstructural ...  

Science Conference Proceedings (OSTI)

Characterization of MOX fuel pellets by Photothermal microscopy Correlation Between Thermal Conductivity and Microstructural Evolutions in CeO2 Upon...

136

Dog Evolution  

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

Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Dog Evolution Name: amy w Location: NA Country: NA Date: NA Question: Are dogs...

137

Silicon nucleation and film evolution on silicon dioxide using disilane: Rapid thermal chemical vapor deposition of very smooth silicon at high deposition rates  

SciTech Connect

An investigation of Si{sub 2}H{sub 6} and H{sub 2} for rapid thermal chemical vapor deposition (RTCVD) of silicon on SiO{sub 2} has been performed at temperatures ranging from 590 to 900 C and pressures ranging from 0.1 to 1.5 Torr. Deposition at 590 C yields amorphous silicon films with the corresponding ultrasmooth surface with a deposition rate of 68 nm/min. Cross-sectional transmission electron microscopy of a sample deposited at 625 C and 1 Torr reveals a bilayer structure which is amorphous at the growth surface and crystallized at the oxide interface. Higher temperatures yield polycrystalline films where the surface roughness depends strongly on both deposition pressure and temperature. Silane-based amorphous silicon deposition in conventional systems yields the expected ultrasmooth surfaces, but at greatly reduced deposition rates unsuitable for single-wafer processing. However, disilane, over the process window considered here, yields growth rates high enough to be appropriate for single-wafer manufacturing, thus providing a viable means for deposition of very smooth silicon films on SiO{sub 2} in a single-wafer environment.

Violette, K.E.; Oeztuerk, M.C.; Christensen, K.N.; Maher, D.M. [North Carolina State Univ., Raleigh, NC (United States)

1996-02-01T23:59:59.000Z

138

Developing models of aerosol representation to investigate composition, evolution, optical properties, and CCN spectra using measurements of size-resolved hygroscopicity  

E-Print Network (OSTI)

A Differential Mobility Analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) was used to measure size distributions, hygroscopicity, and volatility during the May 2003 Aerosol Intensive Operational Period at the Central Facility of the Atmospheric Radiation Measurement Southern Great Plains site. Hygroscopic growth factor distributions for particles at eight dry diameters ranging from 0.012 µm to 0.600 µm were measured. These measurements, along with backtrajectory clustering, were used to infer aerosol composition and evolution. The hygroscopic growth of the smallest and largest particles analyzed was typically less than that of particles with dry diameters of about 0.100 µm. Condensation of secondary organic aerosol on nucleation mode particles may be responsible for the minimal growth observed at the smallest sizes. Growth factor distributions of the largest particles typically contained a non-hygroscopic mode believed to be composed of dust. A model was developed to characterize the hygroscopic properties of particles within a size distribution mode through analysis of the fixed-size hygroscopic growth measurements. This model was used to examine three cases in which the sampled aerosol evolved over a period of hours or days. Additionally, size and hygroscopicity information were combined to model the aerosol as a population of multi-component particles. With this model, the aerosol hygroscopic growth factor f(RH), relating the submicron scattering at high RH to that at low RH, is predicted. The f(RH) values predicted when the hygroscopic fraction of the aerosol is assumed to be metastable agree better with measurements than do those predicted under the assumption of crystalline aerosol. Agreement decreases at RH greater than 65%. This multi-component aerosol model is used to derive cloud condensation nuclei (CCN) spectra for comparison with spectra measured directly with two Desert Research Institute (DRI) CCN spectrometers. Among the 1490 pairs of DMA/TDMA-predicted and DRI-measured CCN concentrations at various critical supersaturations from 0.02-1.05%, the sample number-weighted mean R2 value is 0.74. CCN concentrations are slightly overpredicted at both the lowest (0.02-0.04%) and highest (0.80-1.05%) supersaturations measured. Overall, this multi-component aerosol model based on size distributions and size-resolved hygroscopicity yields reasonable predictions of the humidity-dependent optical properties and CCN spectra of the aerosol.

Gasparini, Roberto

2003-05-01T23:59:59.000Z

139

Measurement of thermal neutron cross section and resonance integral for the {sup 170}Er(n,{gamma}){sup 171}Er reaction by using a {sup 55}Mn monitor  

Science Conference Proceedings (OSTI)

The thermal neutron cross section and the resonance integral of the reaction {sup 170}Er(n,{gamma}){sup 171}Er were measured by the Cd-ratio method using a {sup 55}Mn monitor as single comparator. Analytical grade MnO{sub 2} and Er{sub 2}O{sub 3} powder samples with and without a cylindrical 1 mm Cd shield box were irradiated in an isotropic neutron field obtained from three {sup 241}Am-Be neutron sources. The induced activities in the samples were measured with a 120.8% relative efficiency p-type HPGe detector. The correction factors for gamma-ray attenuation (F{sub g}), thermal neutron self-shielding (G{sub th}), and resonance neutron self-shielding (G{sub epi}) effects, and the epithermal neutron spectrum shape factor ({alpha}) were taken into account. The thermal neutron cross section for the (n,{gamma}) reaction in {sup 170}Er has been determined to be 8.00 {+-} 0.56 b, relative to that of the {sup 55}Mn monitor. However, some previously reported experimental results compared to the present result show a large discrepancy ranging from 8.3 to 86%. The present result is, in general, in good agreement with the recently measured values by 9%. According to the definition of Cd cut-off energy at 0.55 eV, the resonance integral obtained is 44.5 {+-} 4.0 b, which is determined relative to the reference integral value of the {sup 55}Mn monitor by using cadmium ratios. The existing experimental data for the resonance integral are distributed between 18 and 43 b. The present resonance integral value agrees only with the measurement of 43 {+-} 5 b by Gillette [Thermal Cross Section and Resonance Integral Studies, ORNL-4155, 15 (1967)] within uncertainty limits.

Yuecel, Haluk [Turkish Atomic Energy Authority (TAEK), Besevler Campus, 06100 Tandogan-Ankara (Turkey); Budak, M. Gueray; Karadag, Mustafa [Gazi University, Gazi Education Faculty, 06500 Teknikokullar-Ankara (Turkey)

2007-09-15T23:59:59.000Z

140

Thermal performance measurements of sealed insulating glass units with low-E coatings using the MoWiTT (Mobile Window Thermal Test) field-test facility  

SciTech Connect

Using data obtained in a mobile field-test facility, measured performance of clear and low-emissivity double-glazing units is presented for south-facing and north-facing orientations. The changes in U-value and shading coefficient resulting from addition of the low-E coating are found to agree with theoretical expectations for the cold spring test conditions. Accurate nighttime U-values were derived from the data and found to agree with calculations. Expected correlation between U-value and wind speed was not observed in the data; a plausible experimental reason for this is advanced.

Klems, J.; Keller, H.

1986-12-01T23:59:59.000Z

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141

A High-Accuracy Multiwavelength Radiometer for In Situ Measurements in the Thermal Infrared. Part II: Behavior in Field Experiments  

Science Conference Proceedings (OSTI)

The performances of the new conveyable low-noise infrared radiometer for measurements of atmosphere and ground surface targets, or CLIMAT, are presented for in situ measurements. For this, quantitative analyses were carried out on measurements ...

Grard Brogniez; Christophe Pietras; Michel Legrand; Philippe Dubuisson; Martial Haeffelin

2003-07-01T23:59:59.000Z

142

Thermal neutron detection system  

DOE Patents (OSTI)

According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

2000-01-01T23:59:59.000Z

143

Measurement of Three Critical Parameters as a Basis for a Simple Thermal Barrier Coating Life Prediction Methodology  

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

Three Critical Parameters Three Critical Parameters As A Basis for A Simple Thermal Barrier Coating Life Prediction Methodology University of Connecticut Eric Jordan and Maurice Gell SCIES Project 02- 01- SR 097 DOE COOPERATIVE AGREEMENT DE-FC26-02NT41431 Tom J. George, Program Manager, DOE/NETL Richard Wenglarz, Manager of Research, SCIES Project Awarded (05/01/02, 36 Month Duration) $ 478,495 Total Contract Value ($ 478,495 DOE) Gas Turbine Need * Industrial Gas Turbine Performance & Durability Depend Strongly On Use Of Thermal Barrier Coatings * Aggressive Application of TBCs Limited By Lack of NDI And Lifing Methods University of Connecticut Gas Turbine Need Non-Destructive Assessment of Remaining Life Strongly Impacts Operating Cost * Reduce occurrence of unplanned shut down * Reduce wasteful precautionary part replacement

144

THE {sup 12}C/{sup 13}C RATIO ON TITAN FROM CASSINI INMS MEASUREMENTS AND IMPLICATIONS FOR THE EVOLUTION OF METHANE  

SciTech Connect

We have re-evaluated the Cassini Ion Neutral Mass Spectrometer (INMS) {sup 12}C/{sup 13}C ratios in the upper atmosphere of Titan based on new calibration sensitivities and an improved model for the NH{sub 3} background in the {sup 13}CH{sub 4} mass channel. The INMS measurements extrapolated to the surface give a {sup 12}C/{sup 13}C in CH{sub 4} of 88.5 {+-} 1.4. We compare the results to a revised ratio of 91.1 {+-} 1.4 provided by the Huygens Gas Chromatograph Mass Spectrometer and 86.5 {+-} 7.9 provided by the Cassini Infrared Spectrometer and determine implications of the revised ratios for the evolution of methane in Titan's atmosphere. Because the measured {sup 12}C/{sup 13}C is within the probable range of primordial values, we can only determine an upper boundary for the length of time since methane began outgassing from the interior, assuming that outgassing of methane (e.g., cryovolcanic activity) has been continuous ever since. We find that three factors play a crucial role in this timescale: (1) the escape rate of methane, (2) the difference between the current and initial ratios and the rate of methane, and (3) production or resupply due to cryovolcanic activity. We estimate an upper limit for the outgassing timescale of 470 Myr. This duration can be extended to 940 Myr if production rates are large enough to counteract the fractionation due to escape and photochemistry. There is no lower limit to the timescale because the current ratios are within the range of possible primordial values.

Mandt, Kathleen E.; Waite, J. Hunter; Teolis, Benjamin; Magee, Brian A.; Bell, Jared [Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228 (United States); Westlake, Joseph H. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD (United States); Nixon, Conor A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Mousis, Olivier [Institut UTINAM, Universite de Franche-Comte, CNRS/INSU, UMR 6213, Observatoire des Sciences de l'Univers de Besancon (France); Lunine, Jonathan I. [Department of Astronomy, Cornell University, Ithaca, NY (United States)

2012-04-20T23:59:59.000Z

145

A High-Accuracy Multiwavelength Radiometer for In Situ Measurements in the Thermal Infrared. Part I: Characterization of the Instrument  

Science Conference Proceedings (OSTI)

The new infrared radiometer (conveyable low-noise infrared radiometer for measurements of atmosphere and ground surface targets, or CLIMAT) is a highly sensitive field instrument designed to measure brightness temperatures or radiances in the ...

Michel Legrand; Christophe Pietras; Grard Brogniez; Martial Haeffelin; Nader Khalil Abuhassan; Michal Sicard

2000-09-01T23:59:59.000Z

146

February 20, 1991 Thermalization of high Energy Particles in a  

E-Print Network (OSTI)

revised February 20, 1991 Thermalization of high Energy Particles in a Cold Gas K.T. Waldeer and H to be answered are as to the thermalization time, the temporal evolution of the energy spectra of the gas T . We ask for the thermalization time and the temporal evolution of the energy spectra. We

Waldeer, Thomas

147

Temporal Evolution of the Solar-Wind Electron Core Density at Solar Minimum by Correlating SWEA Measurements from STEREO A and B  

E-Print Network (OSTI)

E. : 2006, Living Rev. Solar Phys. 3, 1. McComas, D.J. ,Temporal Evolution of the Solar-Wind Electron Core DensityGiammanco, C. , et al. : 2009, Solar Phys. 256, 365. Opitz,

2010-01-01T23:59:59.000Z

148

Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U  

SciTech Connect

We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for {sup 99}Mo, {sup 95}Zr, {sup 137}Cs, {sup 140}Ba, {sup 141,143}Ce, and {sup 147}Nd. Modest incident-energy dependence exists for the {sup 147}Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by {approx}5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried over to the ENDF/B-VII.0 library, except for {sup 99}Mo where the present results are about 4%-relative higher for neutrons incident on {sup 239}Pu and {sup 235}U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the {sup 147}Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

Selby, H.D., E-mail: hds@lanl.go [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2010-12-15T23:59:59.000Z

149

Chemical Evolution  

E-Print Network (OSTI)

In this series of lectures we first describe the basic ingredients of galactic chemical evolution and discuss both analytical and numerical models. Then we compare model results for the Milky Way, Dwarf Irregulars, Quasars and the Intra-Cluster- Medium with abundances derived from emission lines. These comparisons allow us to put strong constraints on the stellar nucleosynthesis and the mechanisms of galaxy formation.

Francesca Matteucci

2007-04-05T23:59:59.000Z

150

Pressure Measurements in a PBX 9501 Gauged Acceptor When Impacted by a Steel Plate that is Accelerated by a Thermally Cooked Off PBX 9501 Charge  

DOE Green Energy (OSTI)

Measuring the violence of a thermal explosion of a cased explosive is important for evaluating safety issues of explosive devices in fires. A sympathetic initiation scenario was studied here where a 9.0 cm diameter by 2.5 cm thick disc of PBX 9501 donor charge encased in a 304 stainless steel assembly was heated on top and bottom flat surfaces until it thermally exploded. The initial heating rate at the metal/explosive interface was 5 C per minute until it reaches 170 C; then this temperature is held for 35 minutes to allow temperature equilibration to within a few degrees throughout the explosive. The heating resumed at a rate of 1 C per minute until the PBX 9501 donor thermally exploded. A PBX 9501 acceptor charge with carbon resistor and manganin foil pressure gauges inserted at various depths was placed at a 10 cm standoff distance from the donor charge's top steel cover plate. Piezoelectric arrival time pins were placed in front of the acceptor surface to measure the velocity and shape of the impacting plate. The stainless steel cover plate of the donor charge had a nominal velocity of 0.55 {+-} 0.04 mm/{micro}s upon impact and was non-symmetrically warped. The impact of the tilted curved plate induced a three-dimensional compression wave into the acceptor. The rise times of the pressure waves were nominally 1.5 {micro}s with the closest carbon resistor gauges giving peak pressure of 10 kb that decayed to 3 kb for a wave run distance of 2.4 cm.

Forbes, J W; Garcia, F; Urtiew, P A; Vandersall, K S; Greenwood, D W; Tarver, C M

2002-03-11T23:59:59.000Z

151

Thermal Characterization of Nanostructures and Advanced Engineered Materials  

E-Print Network (OSTI)

A. and McEuen, P. L. , Thermal Transport Measurements ofTomanek, D. , Unusually High Thermal Conductivity of Carbonand Lau, C. N. , Superior thermal conductivity of single-

Goyal, Vivek Kumar

2011-01-01T23:59:59.000Z

152

Comparison of different experimental and analytical measures of the thermal annealing response of neutron-irradiated RPV steels  

Science Conference Proceedings (OSTI)

The thermal annealing response of several materials as indicated by Charpy transition temperature (TT) and upper-shelf energy (USE), crack initiation toughness, K{sub Jc}, predictive models, and automated-ball indentation (ABI) testing are compared. The materials investigated are representative reactor pressure vessel (RPV) steels (several welds and a plate) that were irradiated for other tasks of the Heavy-Section Steel Irradiation (HSSI) Program and are relatively well characterized in the unirradiated and irradiated conditions. They have been annealed at two temperatures, 343 and 454 C (650 and 850 F) for varying lengths of time. The correlation of the Charpy response and the fracture toughness, ABI, and the response predicted by the annealing model of Eason et al. for these conditions and materials appears to be reasonable. The USE after annealing at the temperature of 454 C appears to recover at a faster rate than the TT, and even over-recovers (i.e., the recovered USE exceeds that of the unirradiated material).

Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1997-05-01T23:59:59.000Z

153

Preliminary measurements of the thermal conductivity of rocks from LASL geothermal test holes GT-1 and GT-2  

DOE Green Energy (OSTI)

The conductivities on a number of dry rocks have been measured in an air environment. These experimental values are probably about 10 percent lower than the in situ values. Initial attempts to prepare ''wet'' rock samples (rocks saturated with water) have so far resulted in only ''damp'' rocks. Considerable effort will be required to characterize the crack system in ''solid'' rocks and to predict the probable conductivity values for in situ conditions.

Sibbitt, W.L.

1975-12-01T23:59:59.000Z

154

THERMAL RECOVERY  

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

THERMAL RECOVERY Thermal recovery comprises the techniques of steamflooding, cyclic steam stimulation, and in situ combustion. In steamflooding, high-temperature steam is injected...

155

National Solar Thermal Test Facility  

SciTech Connect

This is a brief report about a Sandia National Laboratory facility which can provide high-thermal flux for simulation of nuclear thermal flash, measurements of the effects of aerodynamic heating on radar transmission, etc

Cameron, C.P.

1989-12-31T23:59:59.000Z

156

A statistical method for estimating wood thermal diffusivity and probe geometry using in situ heat response curves from sap flow measurements  

SciTech Connect

The heat pulse method is widely used to measure water flux through plants; it works by inferring the velocity of water through a porous medium from the speed at which a heat pulse is propagated through the system. No systematic, non-destructive calibration procedure exists to determine the site-specific parameters necessary for calculating sap velocity, e.g., wood thermal diffusivity and probe spacing. Such parameter calibration is crucial to obtain the correct transpiration flux density from the sap flow measurements at the plant scale; and consequently, to up-scale tree-level water fluxes to canopy and landscape scales. The purpose of this study is to present a statistical framework for estimating the wood thermal diffusivity and probe spacing simutaneously from in-situ heat response curves collected by the implanted probes of a heat ratio apparatus. Conditioned on the time traces of wood temperature following a heat pulse, the parameters are inferred using a Bayesian inversion technique, based on the Markov chain Monte Carlo sampling method. The primary advantage of the proposed methodology is that it does not require known probe spacing or any further intrusive sampling of sapwood. The Bayesian framework also enables direct quantification of uncertainty in estimated sap flow velocity. Experiments using synthetic data show that repeated tests using the same apparatus are essential to obtain reliable and accurate solutions. When applied to field conditions, these tests are conducted during different seasons and automated using the existing data logging system. The seasonality of wood thermal diffusivity is obtained as a by-product of the parameter estimation process, and it is shown to be affected by both moisture content and temperature. Empirical factors are often introduced to account for the influence of non-ideal probe geometry on the estimation of heat pulse velocity, and they are estimated in this study as well. The proposed methodology can be applied for the calibration of existing heat ratio sap flow systems at other sites. It is especially useful when an alternative transpiration calibration device, such as a lysimeter, is not available.

Chen, Xingyuan; Miller, Gretchen R.; Rubin, Yoram; Baldocchi, Dennis

2012-09-13T23:59:59.000Z

157

Skin Evolution  

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

Skin Evolution Skin Evolution Name: Olga Location: N/A Country: N/A Date: N/A Question: Do you think it is possible that our ancestors were actually black, and that a gene mutation for an enzyme in the metabollic pathway of melanin meant that not enough melanin was produced some of us ended up with white skin. Primitive apes have black skin, and we evolved from them, so doesn't this mean that humans orginally had black skin??? Replies: Most likely, yes, humans probably evolved from dark-skinned ancestors. I will take issue, however, with your statement that "primitive apes have black skin;" we can't say that for absolute certain, because we have no primitive apes to compare to. All we have now are modern apes. All modern apes - homo sapiens, pan troglodytes, gorilla gorilla - are highly, probably equally, evolved. (One could make an argument that homo sapiens is in many ways more generalized - note the generalized dentition, fragile skeleton, etc. - than other modern apes, and thus could be said to be more primitive.) As far as that goes, the only modern apes with white skin I know of are a color variant of homo sapiens.

158

Preliminary requirements for thermal storage subsystems in solar thermal applications  

DOE Green Energy (OSTI)

Methodologies for the analysis of value and comparing thermal storage concepts are presented. Value is a measure of worth and is determined by the cost of conventional fuel systems. Value data for thermal storage in large solar thermal electric power applications are presented. Thermal storage concepts must be compared when all are performing the same mission. A method for doing that analysis, called the ranking index, is derived. Necessary data to use the methodology are included.

Copeland, R.J.

1980-04-01T23:59:59.000Z

159

Thermal regimes of Malaysian sedimentary basins  

Science Conference Proceedings (OSTI)

Properly corrected and calibrated thermal data are important in estimating source-rock maturation, diagenetics, evolution of reservoirs, pressure regimes, and hydrodynamics. Geothermal gradient, thermal conductivity, and heat flow have been determined for the sedimentary succession penetrated by exploratory wells in Malaysia. Geothermal gradient and heat-flow maps show that the highest average values are in the Malay Basin. The values in the Sarawak basin are intermediate between those of the Malay basin and the Sabah Basin, which contains the lowest average values. Temperature data were analyzed from more than 400 wells. An important parameter that was studied in detail is the circulation time. The correct circulation time is essential in determining the correct geothermal gradient of a well. It was found that the most suitable circulation time for the Sabah Basin is 20 hr, 30 hr for the Sarawak Basin and 40 hr for the Malay Basin. Values of thermal conductivity, determined from measurement and calibrated calculations, were grouped according to depositional units and cycles in each basin.

Abdul Halim, M.F. (Petronas Research and Scientific Services, Selangor (Malaysia))

1994-07-01T23:59:59.000Z

160

Ground surface temperature reconstructions: Using in situ estimates for thermal conductivity acquired with a fiber-optic distributed thermal perturbation sensor  

E-Print Network (OSTI)

with homogeneous thermal properties, to invert cooling data.thermal simulations of DTPS testing showing modeled coolingand cooling. The match between measured and modeled thermal

Freifeld, B.M.

2009-01-01T23:59:59.000Z

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


161

Solar Thermal Conversion  

DOE Green Energy (OSTI)

The thermal conversion process of solar energy is based on well-known phenomena of heat transfer (Kreith 1976). In all thermal conversion processes, solar radiation is absorbed at the surface of a receiver, which contains or is in contact with flow passages through which a working fluid passes. As the receiver heats up, heat is transferred to the working fluid which may be air, water, oil, or a molten salt. The upper temperature that can be achieved in solar thermal conversion depends on the insolation, the degree to which the sunlight is concentrated, and the measures taken to reduce heat losses from the working fluid.

Kreith, F.; Meyer, R. T.

1982-11-01T23:59:59.000Z

162

Updraft Evolution: A Perspective from Cloud Base  

Science Conference Proceedings (OSTI)

A Queen Air, instrumented to make 1-Hz measurements of the kinematic, dynamic, and thermodynamic fields, and radar, mesonet, and soundings from the Cooperative Convective Precipitation Experiment 1981 is used to monitor the evolution of the ...

Gary M. Barnes

1995-09-01T23:59:59.000Z

163

High temperature thermographic measurements of laser heated silica  

SciTech Connect

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

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

2009-11-02T23:59:59.000Z

164

Evaluation of the thermal resistance of a roof-mounted multi-reflective radiant barrier for tropical and humid conditions: Experimental study from field measurements  

E-Print Network (OSTI)

This paper deals with the experimental evaluation of a roof-mounted multi-reflective radiant barrier (MRRB), installed according to the state of the art, on a dedicated test cell. An existing experimental device was completed with a specific system for the regulation of the airflow rate in the upper air layer included in a typical roof from Reunion Island. Several experimental sequences were conducted to determine the thermal resistance of the roof according to several parameters and following a specific method. The mean method, well known in international standards (ISO 9869 - 1994) for the determination of the thermal resistance using dynamic data, was used. The method was implemented in a building simulation code in order to allow the determination of the thermal indicator automatically. Experimental results are proposed according to different seasonal periods and for different values of the airflow rate in the upper air layer.

Frdric Miranville; Ali Hamada Fakra; Stphane Guichard; Harry Boyer; Jean Philippe Praene; Dimitri Bigot

2012-12-19T23:59:59.000Z

165

Evaluation of the thermal resistance of a roof-mounted multi-reflective radiant barrier for tropical and humid conditions: Experimental study from field measurements  

E-Print Network (OSTI)

This paper deals with the experimental evaluation of a roof-mounted multi-reflective radiant barrier (MRRB), installed according to the state of the art, on a dedicated test cell. An existing experimental device was completed with a specific system for the regulation of the airflow rate in the upper air layer included in a typical roof from Reunion Island. Several experimental sequences were conducted to determine the thermal resistance of the roof according to several parameters and following a specific method. The mean method, well known in international standards (ISO 9869 - 1994) for the determination of the thermal resistance using dynamic data, was used. The method was implemented in a building simulation code in order to allow the determination of the thermal indicator automatically. Experimental results are proposed according to different seasonal periods and for different values of the airflow rate in the upper air layer

Miranville, Frdric; Guichard, Stphane; Boyer, Harry; Praene, Jean Philippe; Bigot, Dimitri

2012-01-01T23:59:59.000Z

166

Non thermal emission in clusters of galaxies  

E-Print Network (OSTI)

I briefly review our current knowledge of the non thermal emission from galaxy clusters and discuss future prospect with Simbol-X. Simbol-X will map the hard X-ray emission in clusters, determine its origin and disentangle the thermal and non-thermal components. Correlated with radio observations, the observation of the non-thermal X-ray emission, when confirmed, will allow to map both the magnetic field and the relativistic electron properties, key information to understand the origin and acceleration of relativistic particles in clusters and its impact on cluster evolution.

Arnaud, M

2008-01-01T23:59:59.000Z

167

Evolution strategies: basic introduction  

Science Conference Proceedings (OSTI)

This tutorial gives a basic introduction to evolution strategies, a class of evolutionary algorithms. Key features such as mutation, recombination and selection operators are explained, and specifically the concept of self-adaptation of strategy parameters ... Keywords: evolution strategies

Thomas Bck

2013-07-01T23:59:59.000Z

168

Differential Thermal Analysis of Nickel-Base Superalloys  

Science Conference Proceedings (OSTI)

Differential thermal analysis was performed on over 200 nickel-base superalloys that ... differential thermal analysis (DTA) to simply and accurately measure.

169

Time Evolution of Entanglement Entropy from Black Hole Interiors  

E-Print Network (OSTI)

We compute the time-dependent entanglement entropy of a CFT which starts in relatively simple initial states. The initial states are the thermofield double for thermal states, dual to eternal black holes, and a particular pure state, dual to a black hole formed by gravitational collapse. The entanglement entropy grows linearly in time. This linear growth is directly related to the growth of the black hole interior measured along "nice" spatial slices. These nice slices probe the spacelike direction in the interior, at a fixed special value of the interior time. In the case of a two-dimensional CFT, we match the bulk and boundary computations of the entanglement entropy. We briefly discuss the long time behavior of various correlators, computed via classical geodesics or surfaces, and point out that their exponential decay comes about for similar reasons. We also present the time evolution of the wavefunction in the tensor network description.

Thomas Hartman; Juan Maldacena

2013-03-05T23:59:59.000Z

170

Time Evolution of Entanglement Entropy from Black Hole Interiors  

E-Print Network (OSTI)

We compute the time-dependent entanglement entropy of a CFT which starts in relatively simple initial states. The initial states are the thermofield double for thermal states, dual to eternal black holes, and a particular pure state, dual to a black hole formed by gravitational collapse. The entanglement entropy grows linearly in time. This linear growth is directly related to the growth of the black hole interior measured along "nice" spatial slices. These nice slices probe the spacelike direction in the interior, at a fixed special value of the interior time. In the case of a two-dimensional CFT, we match the bulk and boundary computations of the entanglement entropy. We briefly discuss the long time behavior of various correlators, computed via classical geodesics or surfaces, and point out that their exponential decay comes about for similar reasons. We also present the time evolution of the wavefunction in the tensor network description.

Hartman, Thomas

2013-01-01T23:59:59.000Z

171

Chemical evolution STRUCTURE OF GALAXIES  

E-Print Network (OSTI)

Outline Absorption Chemical evolution STRUCTURE OF GALAXIES 8. Absorption; chemical evolution Piet Piet van der Kruit, Kapteyn Astronomical Institute Absorption; chemical evolution #12;Outline Absorption Chemical evolution Outline Absorption Holmberg's analysis Analysis of Disney et al. Edge

Kruit, Piet van der

172

Nanoscale thermal transport and the thermal conductance of interfaces  

E-Print Network (OSTI)

absorption depends on temperature of the nanotube · Assume heat capacity is comparable to graphite · Cooling conductance · Pump probe apparatus · Transient absorption ­ Carbon nanotubes and thermal transport at hard optical absorption of nanoparticles and nanotubes in liquid suspensions. ­ Measure the thermal relaxation

Braun, Paul

173

Characterization of Thermal Properties of Curaua Fibers by ...  

Science Conference Proceedings (OSTI)

... among others, are required especially in the case of an insulating natural fiber. In the present work, thermal properties of the curaua fibers were investigated by ... Evolution of Crystallographic Texture of Cold Roll Bonding and Annealing...

174

Numerical Investigation of Spectral Evolution of Wind Waves. Part II: Dissipation Term and Evolution Tests  

Science Conference Proceedings (OSTI)

Numerical simulations of the wind-wave spectrum evolution are conducted by means of new observation-based wind-input and wave dissipation functions obtained in the Lake George field experiment. This experiment allowed simultaneous measurements of ...

Alexander V. Babanin; Kakha N. Tsagareli; I. R. Young; David J. Walker

2010-04-01T23:59:59.000Z

175

Thermal conductivity of aqueous foam  

Science Conference Proceedings (OSTI)

Thermal conductivity plays an important part in the response of aqueous foams used as geothermal drilling fluids. The thermal conductivity of these foams was measured at ambient conditions using the thermal conductivity probe technique. Foam densities studied were from 0.03 to 0.2 g/cm/sup 3/, corresponding to liquid volume fractions of the same magnitude. Microscopy of the foams indicated bubble sizes in the range 50 to 300 ..mu..m for nitrogen foams, and 30 to 150 ..mu..m for helium foams. Bubble shapes were observed to be polyhedral at low foam densities and spherical at the higher densities. The measured conductivity values ranged from 0.05 to 0.12 W/m-K for the foams studied. The predicted behavior in foam conductivity caused by a change in the conductivity of the discontinuous gas phase was observed using nitrogen or helium gas in the foams. Analysis of the probe response data required an interpretation using the full intergral solution to the heat conduction equation, since the thermal capacity of the foam was small relative to the thermal mass of the probe. The measurements of the thermal conductivity of the foams were influenced by experimental effects such as the probe input power, foam drainage, and the orientation of the probe and test cell. For nitrogen foams, the thermal conductivity vs liquid volume fraction was observed to fall between predictions based on the parallel ordering and Russell models for thermal conduction in heterogeneous materials.

Drotning, W.D.; Ortega, A.; Havey, P.E.

1982-05-01T23:59:59.000Z

176

Inhomogeneous holographic thermalization  

E-Print Network (OSTI)

The sudden injection of energy in a strongly coupled conformal field theory and its subsequent thermalization can be holographically modeled by a shell falling into anti-de Sitter space and forming a black brane. For a homogeneous shell, Bhattacharyya and Minwalla were able to study this process analytically using a weak field approximation. Motivated by event-by-event fluctuations in heavy ion collisions, we include inhomogeneities in this model, obtaining analytic results in a long wavelength expansion. In the early-time window in which our approximations can be trusted, the resulting evolution matches well with that of a simple free streaming model. Near the end of this time window, we find that the stress tensor approaches that of second-order viscous hydrodynamics. We comment on possible lessons for heavy ion phenomenology.

V. Balasubramanian; A. Bernamonti; J. de Boer; B. Craps; L. Franti; F. Galli; E. Keski-Vakkuri; B. Mller; A. Schfer

2013-07-26T23:59:59.000Z

177

Thermal Properties  

Science Conference Proceedings (OSTI)

Table 12   Thermal conductivities of polymers and other materials...40,000 2.8 Aluminum 24,000 1.7 Steel 5000 0.35 Granite 350 0.02 Crown glass (75 wt% silica) 90 0.006 Source: Ref 4...

178

Thermal transient anemometer  

DOE Patents (OSTI)

A thermal transient anemometer is disclosed having a thermocouple probe which is utilized to measure the change in temperature over a period of time to provide a measure of fluid flow velocity. The thermocouple probe is located in the fluid flow path and pulsed to heat or cool the probe. The cooling of the heated probe or the heating of the cooled probe from the fluid flow over a period of time is measured to determine the fluid flow velocity. The probe is desired to be locally heated near the tip to increase the efficiency of devices incorporating the probe. 12 figs.

Bailey, J.L.; Vresk, J.

1989-07-18T23:59:59.000Z

179

LABORATORY VI ENERGY AND THERMAL PROCESSES  

E-Print Network (OSTI)

LABORATORY VI ENERGY AND THERMAL PROCESSES Lab VI - 1 The change of the internal energy of a system temperature by sweating to cool down. Running seems to be the conversion of chemical energy to thermal energy energy into thermal energy, you decide to make some measurements in the laboratory. To make

Minnesota, University of

180

PCM energy storage during defective thermal cycling.  

E-Print Network (OSTI)

??Incomplete thermal cycling affects storage capacities of phase change materials (PCMs). Existing PCM measuring methods are presented with their drawbacks. A new device named the (more)

Koekenbier, S.F.

2011-01-01T23:59:59.000Z

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


181

Measuring the Impact of Experimental Parameters upon the Estimated Thermal Conductivity of Closed-Cell Foam Insulation Subjected to an Accelerated Aging Protocol ? Two Year Results  

SciTech Connect

The thermal conductivity of many closed-cell foam insulation products changes over time as production gases diffuse out of the cell matrix and atmospheric gases diffuse into the cells. Thin slicing has been shown to be an effective means of accelerating this process in such a way as to produce meaningful results. Efforts to produce a more prescriptive version of the ASTM C 1303 standard test method have led to a broad ruggedness test. This test includes the aging of full size insulation specimens for time periods up to five years for later comparison to the predicted results. Experimental parameters under investigation include: slice thickness, slice origin (at the surface or from the core of the slab), thin slice stack composition, product facings, original product thickness, product density, and product type. This paper will compare the results after two years of full-thickness aging.

Stovall, Therese K [ORNL

2009-01-01T23:59:59.000Z

182

High Temperature Measurements Of Martensitic transformations Using Digital Holography  

SciTech Connect

During thermal cycling of nickel-aluminum-platinum (NiAlPt) and single crystal Fe-15Cr-15Ni alloys, the structural changes associated with the martensite to austenite phase transformation were measured using dual-wavelength digital holography. Real-time in-situ measurements reveal the formation of striations within the NiPtAl alloy at 70 C and the FeCrNi alloy at 520 C. The results demonstrate that digital holography is an effective technique for acquiring non-contact, high precision information of the surface evolution of alloys at high temperatures.

Thiesing, Benjamin [Northern Arizona University; Mann, Christopher J [Northern Arizona University; Dryepondt, Sebastien N [ORNL

2013-01-01T23:59:59.000Z

183

Modelling the chemical evolution  

E-Print Network (OSTI)

Advanced observational facilities allow to trace back the chemical evolution of the Universe, on the one hand, from local objects of different ages and, secondly, by direct observations of redshifted objects. The chemical enrichment serves as one of the cornerstones of cosmological evolution. In order to understand this chemical evolution in morphologically different astrophysical objects models are constructed based on analytical descriptions or numerical methods. For the comparison of their chemical issues, as there are element abundances, gradients, and ratios, with observations not only the present-day values are used but also their temporal evolution from the first era of metal enrichment. Here we will provide some insight into basics of chemical evolution models, highlight advancements, and discuss a few applications.

Hensler, Gerhard

2010-01-01T23:59:59.000Z

184

THERMALLY DRIVEN ATMOSPHERIC ESCAPE  

Science Conference Proceedings (OSTI)

Accurately determining the escape rate from a planet's atmosphere is critical for determining its evolution. A large amount of Cassini data is now available for Titan's upper atmosphere and a wealth of data is expected within the next decade on escape from Pluto, Mars, and extra-solar planets. Escape can be driven by upward thermal conduction of energy deposited well below the exobase, as well as by nonthermal processes produced by energy deposited in the exobase region. Recent applications of a model for escape driven by upward thermal conduction, called the slow hydrodynamic escape model, have resulted in surprisingly large loss rates for the atmosphere of Titan, Saturn's largest moon. Based on a molecular kinetic simulation of the exobase region, these rates appear to be orders of magnitude too large. Therefore, the slow hydrodynamic model is evaluated here. It is shown that such a model cannot give a reliable description of the atmospheric temperature profile unless it is coupled to a molecular kinetic description of the exobase region. Therefore, the present escape rates for Titan and Pluto must be re-evaluated using the atmospheric model described here.

Johnson, Robert E., E-mail: rej@virginia.ed [Engineering Physics, Thornton Hall B102, University of Virginia, Charlottesville, VA 22902 (United States); Physics Department, New York University, New York, NY 10003 (United States)

2010-06-20T23:59:59.000Z

185

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network (OSTI)

aquifers for thermal energy storage. Problems outlined aboveModeling of Thermal Energy Storage in Aquifers," Proceed-ings of Aquifer Thermal Energy Storage Workshop, Lawrence

Tsang, C.-F.

2011-01-01T23:59:59.000Z

186

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network (OSTI)

using aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"Proceed- ings of Aquifer Thermal Energy Storage Workshop,

Tsang, C.-F.

2011-01-01T23:59:59.000Z

187

Geological and thermochronological evolution of the lower crust of southern Africa  

E-Print Network (OSTI)

Geochronological, thermochronological and isotopic studies of kimberlite-borne crustal xenoliths have been used to elucidate the architecture and thermal evolution of the continental lithosphere of southern Africa. U-Pb ...

Schmitz, Mark D. (Mark David), 1972-

2002-01-01T23:59:59.000Z

188

Nuclear Instruments and Methods in Physics Research A 432 (1999) 403}409 Measurement of the thermal and fast neutron #ux in a research  

E-Print Network (OSTI)

. Introduction A new type of "bre detector was developed at Nagoya University recently [1}3] and tested of these two materials are rather similar, the quartz "bre is superior regarding the radiation level in which, development of such a detector is of clear importance, and the measurements reported in this paper contribute

Pázsit, Imre

189

The evolution of Lua  

Science Conference Proceedings (OSTI)

We report on the birth and evolution of Lua and discuss how it moved from a simple configuration language to a versatile, widely used language that supports extensible semantics, anonymous functions, full lexical scoping, proper tail calls, and coroutines.

Roberto Ierusalimschy; Luiz Henrique de Figueiredo; Waldemar Celes

2007-06-01T23:59:59.000Z

190

Wafer heating mechanisms in a molecular gas, inductively coupled plasma: in situ, real time wafer surface measurements and three-dimensional thermal modeling  

Science Conference Proceedings (OSTI)

The authors report measurements and modeling of wafer heating mechanisms in an Ar/O{sub 2} inductively coupled plasma (ICP). The authors employed a commercially available on-wafer sensor system (PlasmaTemp developed by KLA-Tencor) consisting of an on-board electronics module housing battery power and data storage with 30 temperature sensors embedded onto the wafer at different radial positions. This system allows for real time, in situ wafer temperature measurements. Wafer heating mechanisms were investigated by combining temperature measurements from the PlasmaTemp sensor wafer with a three-dimensional heat transfer model of the wafer and a model of the ICP. Comparisons between pure Ar and Ar/O{sub 2} discharges demonstrated that two additional wafer heating mechanisms can be important in molecular gas plasmas compared to atomic gas discharges. The two mechanisms are heating from the gas phase and O-atom surface recombination. These mechanisms were shown to contribute as much as 60% to wafer heating under conditions of low bias power. This study demonstrated how the 'on-wafer' temperature sensor not only yields a temperature profile distribution across the wafer, but can be used to help determine plasma characteristics, such as ion flux profiles or plasma processing temperatures.

Titus, M. J.; Graves, D. B. [Department of Chemical Engineering, University of California, Berkeley, California 94720 (United States)

2008-09-15T23:59:59.000Z

191

Null-Control and Measurable Sets  

E-Print Network (OSTI)

We prove the interior and boundary null-controllability of some parabolic evolutions with controls acting over measurable sets with positive measure.

Apraiz, J

2011-01-01T23:59:59.000Z

192

Effect of Thermal Exposure on Microstructural Evolution in Alloy 718 ...  

Science Conference Proceedings (OSTI)

For an esposure time of 3300 hours at 650cC, the alpha-Cr phase uras obsesved in ... aCr formation may readily occur ivhen the bolts arc exposed in ser\\.ice at.

193

Residual Stress Evolution in Plasma-Sprayed Thermal Barrier ...  

Science Conference Proceedings (OSTI)

... Office of Industrial Technologies, Project Officer, Patricia Hoffman, Advanced Turbine Systems Program, is gratefully acknowledged. Page 4. ...

2002-02-15T23:59:59.000Z

194

Modified Thermal-Optical Analysis Using Spectral Absorption Selectivity to  

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

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

195

CHARACTERIZATION OF CURRENT SHEET EVOLUTION IN A PULSED  

E-Print Network (OSTI)

CHARACTERIZATION OF CURRENT SHEET EVOLUTION IN A PULSED ELECTROMAGNETIC ACCELERATOR J.W. Berkery evolution in a pulsed electromagnetic accelerator is presented based on temporally and spatially resolved field in a pulsed electromagnetic accelerator has been presented. The magnetic field measurements have

Choueiri, Edgar

196

Evolution Vs. Thermodynamics  

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

Evolution Vs. Thermodynamics Evolution Vs. Thermodynamics Name: Murphy iii Status: N/A Age: N/A Location: N/A Country: N/A Date: Around 1993 Question: Does the THEORY of evolution contradict the Second Law of thermodynamics? If not, how can an organic system grow in complexity in light of that law? Do not even try to tell me that hot methane soup has less chaos than cool DNA. Replies: The second law only says that the entropy (disorder) of a complete closed system must increase with time, not that the orderliness of one part of that system cannot increase. Increasing complexity of life must be balanced with more increase of disorder somewhere else in the system. Life itself increases order, but only of a small part of the overall system, whose entropy, when all parts are added up, must always be increasing

197

Thermal indicator for wells  

DOE Patents (OSTI)

Minute durable plate-like thermal indicators are employed for precision measuring static and dynamic temperatures of well drilling fluids. The indicators are small enough and sufficiently durable to be circulated in the well with drilling fluids during the drilling operation. The indicators include a heat resistant indicating layer, a coacting meltable solid component and a retainer body which serves to unitize each indicator and which may carry permanent indicator identifying indicia. The indicators are recovered from the drilling fluid at ground level by known techniques.

Gaven, Jr., Joseph V. (Oakton, VA); Bak, Chan S. (Newbury Park, CA)

1983-01-01T23:59:59.000Z

198

Multispectral thermal imaging  

SciTech Connect

Many remote sensing applications rely on imaging spectrometry. Here the authors use imaging spectrometry for thermal and multispectral signatures measured from a satellite platform enhanced with a combination of accurate calibrations and on-board data for correcting atmospheric distortions. The approach is supported by physics-based end-to-end modeling and analysis, which permits a cost-effective balance between various hardware and software aspects. The goal is to develop and demonstrate advanced technologies and analysis tools toward meeting the needs of the customer; at the same time, the attributes of this system can address other applications in such areas as environmental change, agriculture, and volcanology.

Weber, P.G.; Bender, S.C.; Borel, C.C.; Clodius, W.B.; Smith, B.W. [Los Alamos National Lab., NM (United States). Space and Remote Sensing Sciences Group; Garrett, A.; Pendergast, M.M. [Westinghouse Savannah River Corp., Aiken, SC (United States). Savannah River Technology Center; Kay, R.R. [Sandia National Lab., Albuquerque, NM (United States). Monitoring Systems and Technology Center

1998-12-01T23:59:59.000Z

199

Seasonal thermal energy storage  

DOE Green Energy (OSTI)

This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

1984-05-01T23:59:59.000Z

200

Evolution of supercomputers  

Science Conference Proceedings (OSTI)

Supercomputers are prevalent and vital to scientific research and industrial fields, and may be used to represent the level of national scientific development. A summary of the evolution of supercomputers will help direct the future development of supercomputers ... Keywords: architecture, challenging applications, novel devices, scientific computing, supercomputer

Xianghui Xie; Xing Fang; Sutai Hu; Dong Wu

2010-12-01T23:59:59.000Z

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


201

The evolution of Lisp  

Science Conference Proceedings (OSTI)

Lisp is the world's greatest programming language---or so its proponents think. The structure of Lisp makes it easy to extend the language or even to implement entirely new dialects without starting from scratch. Overall, the evolution of Lisp has been ...

Guy L. Steele; Richard P. Gabriel

1996-01-01T23:59:59.000Z

202

Insights From Laboratory Experiments On Simulated Faults With Application To Fracture Evolution In Geothermal Systems  

Science Conference Proceedings (OSTI)

Laboratory experiments provide a wealth of information related to mechanics of fracture initiation, fracture propagation processes, factors influencing fault strength, and spatio-temporal evolution of fracture properties. Much of the existing literature reports on laboratory studies involving a coupling of thermal, hydraulic, mechanical, and/or chemical processes. As these processes operate within subsurface environments exploited for their energy resource, laboratory results provide insights into factors influencing the mechanical and hydraulic properties of geothermal systems. I report on laboratory observations of strength and fluid transport properties during deformation of simulated faults. The results show systematic trends that vary with stress state, deformation rate, thermal conditions, fluid content, and rock composition. When related to geophysical and geologic measurements obtained from engineered geothermal systems (e.g. microseismicity, wellbore studies, tracer analysis), laboratory results provide a means by which the evolving thermal reservoir can be interpreted in terms of physico-chemical processes. For example, estimates of energy release and microearthquake locations from seismic moment tensor analysis can be related to strength variations observed from friction experiments. Such correlations between laboratory and field data allow for better interpretations about the evolving mechanical and fluid transport properties in the geothermal reservoir ultimately leading to improvements in managing the resource.

Stephen L. Karner, Ph.D

2006-06-01T23:59:59.000Z

203

Mapping the evolution of scientific ideas  

SciTech Connect

Despite the apparent conceptual boundaries of scientific fields, a formal description for their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society PACS numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using Cfinder, an overlapping community finding algorithm, and describe the time evolution of these fields using a community evolution method over the course of 1985-2006. The communities we identify map to known scientific fields, and their age strongly depends on t.heir size, impact and activity. Our analysis further suggests that communities that redefine themselves by merging and creating new groups of ideas tend to have more fitness as measured by the impact per paper, and hence communities with a higher fitness tend to be short-lived. The described approach to quantify the evolution of ideas may be relevant in making predictions about the future of science and how to guide its development.

Roberts, David [Los Alamos National Laboratory; Herrera, Mark [UNIV OF MARYLAND; Gulbahce, Natali [UNIV OF BOSTON

2009-01-01T23:59:59.000Z

204

Dynamical Processes of Block Evolution  

Science Conference Proceedings (OSTI)

The dynamical processes associated with block evolution are investigated by analyzing a GCM run, forced with perpetual January conditions. The core of the analysis lies on the temporal evolution of the blocks and on vorticity budget terms ...

Benjamin A. Cash; Sukyoung Lee

2000-10-01T23:59:59.000Z

205

Estimating evolution of freshness in Internet cache directories under the capture-recapture methodology  

Science Conference Proceedings (OSTI)

In this paper, we describe a new web sampling scheme for measuring the evolution of freshness in search engines. The methodology used is the capture-recapture, which is mainly applied for estimating evolution rates in wildlife biological studies. After ... Keywords: Capture-recapture methodology, Freshness, Internet search services, Web caching, Web evolution

Ioannis Anagnostopoulos; Christos Anagnostopoulos; Dimitrios D. Vergados

2010-04-01T23:59:59.000Z

206

Phase Transformation and Microstructural Evolution  

Science Conference Proceedings (OSTI)

Jul 15, 2013 ... Relationship between Microstructural Evolution, Order-disorder Transformation and Plastic Inhomogeneities during Deformation of Beta Brass.

207

The molecular evolution of development  

E-Print Network (OSTI)

The molecular evolution of development Michael D. Purugganan Summary Morphological differences in understanding the genetic basis behind the evolution of developmental systems. Molecular evolutionary genetics-day attempts to study the evolution of development are centered at the molecular level and exploit

Purugganan, Michael D.

208

Structural evolution and characterization of heteroepitaxial GaSb thin films on Si(111) substrates  

Science Conference Proceedings (OSTI)

This paper describes the structural evolution and characterization of heteroepitaxial GaSb thin films on Si(111) substrates. The growth process used a combination of atomic sources which included the rf sputtering of Sb and the thermal effusion of Ga. The formation of crystalline GaSb thin films required that initially a monolayer thick Sb buffer layer be applied directly to a clean H-passivated Si(111) substrate surface. The resulting film was characterized by high resolution x-ray diffraction, Rutherford backscattering spectrometry, transmission electron microscopy, secondary ion mass spectroscopy, and atomic force microscopy (AFM). The AFM images were taken from the material after several periods of growth to determine the evolution of crystal structure with thickness. Atomic force microscopy images of the film surface showed that the heteroepitaxial layers were formed via the Stranski-Krastanov growth mechanism. This result is consistent with the heteroepitaxial growth of systems representing large differences in lattice constant. The hole mobility and carrier concentration in the deposited material were determined by the Hall measurement, performed at room temperature and on a 140 nm thick sample, to be 66 cm{sup 2}/V sec and 3x10{sup 19} cm{sup -3}, respectively. The carrier mobility was relatively low as expected for measurements taken at room temperature.

Nguyen, Thang; Varhue, Walter; Cross, Michael; Pino, Robinson; Adams, Edward; Lavoie, Mark; Lee, Jaichan [School of Engineering, University of Vermont, Burlington, Vermont 05405 (United States); IBM Corporation, Essex Junction, Vermont 05452 (United States); Department of Materials Science and Engineering, Sung Kyun Kwan University, Suwon 440-746 (Korea, Republic of)

2007-04-01T23:59:59.000Z

209

Thermal well-test method  

DOE Patents (OSTI)

A well-test method involving injection of hot (or cold) water into a groundwater aquifer, or injecting cold water into a geothermal reservoir. By making temperature measurements at various depths in one or more observation wells, certain properties of the aquifer are determined. These properties, not obtainable from conventional well test procedures, include the permeability anisotropy, and layering in the aquifer, and in-situ thermal properties. The temperature measurements at various depths are obtained from thermistors mounted in the observation wells.

Tsang, Chin-Fu (Albany, CA); Doughty, Christine A. (Berkeley, CA)

1985-01-01T23:59:59.000Z

210

Observing the evolution of a quantum system that does not evolve  

E-Print Network (OSTI)

This article deals with the problem of gathering information on the time evolution of a single metastable quantum system whose evolution is impeded by the quantum Zeno effect. It has been found it is in principle possible to obtain some information on the time evolution and, depending on the specific system, even to measure its average decay rate, even if the system does not undergo any evolution at all.

Simone De Liberato

2007-05-16T23:59:59.000Z

211

Transient plane source measurements of the thermal ...  

Science Conference Proceedings (OSTI)

... conductivity of (2.12.2) W/(m K). While the HS bounds are fairly tight in Fig. ... Res 33:363371 8. Xu Y, Chung DDL (2000) Effect of sand addition on ...

2007-11-14T23:59:59.000Z

212

Upgrades in thermal protection for downhole instruments  

DOE Green Energy (OSTI)

Measurement of geophysical parameters in progressively deeper and hotter wells has prompted design changes that improve the performance of downhole instruments and their associated thermal protection systems. This report provides a brief description of the mechanical and thermal loads to which these instruments and systems are subjected. Each design change made to the passive thermal protection system is described along with its resulting improvement. An outline of work being done to scope an active thermal protection system and the preliminary qualitative results are also described. 3 refs., 4 figs.

Bennett, G.A.

1985-01-01T23:59:59.000Z

213

Chemical preconcentrator with integral thermal flow sensor  

DOE Patents (OSTI)

A chemical preconcentrator with integral thermal flow sensor can be used to accurately measure fluid flow rate in a microanalytical system. The thermal flow sensor can be operated in either constant temperature or constant power mode and variants thereof. The chemical preconcentrator with integral thermal flow sensor can be fabricated with the same MEMS technology as the rest of the microanlaytical system. Because of its low heat capacity, low-loss, and small size, the chemical preconcentrator with integral thermal flow sensor is fast and efficient enough to be used in battery-powered, portable microanalytical systems.

Manginell, Ronald P. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM)

2003-01-01T23:59:59.000Z

214

A coupled THC model of the FEBEX in situ test with bentonite swelling and chemical and thermal osmosis  

SciTech Connect

The performance assessment of a geological repository for radioactive waste requires quantifying the geochemical evolution of the bentonite engineered barrier. This barrier will be exposed to coupled thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes. This paper presents a coupled THC model of the FEBEX (Full-scale Engineered Barrier EXperiment) in situ test which accounts for bentonite swelling and chemical and thermal osmosis. Model results attest the relevance of thermal osmosis and bentonite swelling for the geochemical evolution of the bentonite barrier while chemical osmosis is found to be almost irrelevant. The model has been tested with data collected after the dismantling of heater 1 of the in situ test. The model reproduces reasonably well the measured temperature, relative humidity, water content and inferred geochemical data. However, it fails to mimic the solute concentrations at the heater-bentonite and bentonite-granite interfaces because the model does not account for the volume change of bentonite, the CO{sub 2}(g) degassing and the transport of vapor from the bentonite into the granite. The inferred HCO{sub 3}{sup -} and pH data cannot be explained solely by solute transport, calcite dissolution and protonation/deprotonation by surface complexation, suggesting that such data may be affected also by other reactions.

Zheng, L.; Samper, J.; Montenegro, L.

2011-04-01T23:59:59.000Z

215

CPC thermal collector test plan  

DOE Green Energy (OSTI)

A comprehensive set of test procedures has evolved at Argonne National Laboratory for establishing the performance of compound parabolic and related concentrating thermal collectors with large angular fields of view. The procedures range from separate thermal and optical tests, to overall performance tests. A calorimetric ratio technique has been developed to determine the heat output of a collector without knowledge of the heat transfer fluid's mass flow rate and heat capacity. Sepcial attention is paid to the problem of defining and measuring the incident solar flux with respect to which the collector efficiency is to be calculated.

Reed, K A

1977-01-01T23:59:59.000Z

216

HEATS: Thermal Energy Storage  

SciTech Connect

HEATS Project: The 15 projects that make up ARPA-Es HEATS program, short for High Energy Advanced Thermal Storage, seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

None

2012-01-01T23:59:59.000Z

217

Evolution of Dust Extinction and Supernova Cosmology  

E-Print Network (OSTI)

We have made a quantitative calculation for the systematic evolution of average extinction by interstellar dust in host galaxies of high-redshift Type Ia supernovae, by using a realistic model of photometric and chemical evolution of galaxies and supernova rate histories in various galaxy types. We find that average B band extinction at z \\sim 0.5 is typically 0.1-0.2 mag larger than present, under a natural assumption that dust optical depth is proportional to gas column density and gas metallicity. This systematic evolution causes average reddening with E(B-V) \\sim 0.025-0.05 mag with the standard extinction curve, and this is comparable with the observational uncertainty of the reddening of high-redshift supernovae. Therefore, our result does not contradict the observations showing no significant reddening in high-z supernovae. However, the difference in apparent magnitude between an open universe and a \\Lambda-dominated flat universe is only \\sim 0.2 mag at z \\sim 0.5, and hence this systematic evolution of extinction should be taken into account in a reliable measurement of cosmological parameters. Considering this uncertainty, we show that it is difficult to discriminate between an open and \\Lambda-dominated flat cosmologies from the current data.

Tomonori Totani; Chiaki Kobayashi

1999-10-04T23:59:59.000Z

218

Geometrical phase of thermal state in hydrogen atom  

E-Print Network (OSTI)

In this paper, the geometric phase of thermal state in hydrogen atom under the effects of external magnetic field is considered. Especially the effects of the temperature upon the geometric phase is discussed. Also we discuss the time evolution of entanglement of the system. They show some similar behaviors.

Guo-Qiang Zhu

2006-05-08T23:59:59.000Z

219

Transient evolution of a photon gas in the nonlinear QED vacuum  

SciTech Connect

Thermally induced vacuum polarization stemming from QED radiative corrections to the electromagnetic field equations is studied. The physical behavior of thermal radiation, in the nonlinear QED vacuum first described by Heisenberg and Euler, is a problem of some theoretical importance in view of its relation to the cosmic microwave background (CMB), early universe evolution, and Hawking-Unruh radiation. The questions of evolution toward equilibrium, stability, and invariance of thermal radiation under such conditions are of great interest. Our analysis presents novel aspects associated with photon-photon scattering in a photon gas in the framework of quantum kinetic theory. Within the context of the Euler-Heisenberg theory, we show that a homogeneous, isotropic photon gas with arbitrary spectral distribution function evolves toward an equilibrium state with a Bose-Einstein distribution. The transient evolution toward equilibrium of a gas of photons undergoing photon-photon scattering is studied in detail via the Boltzmann transport equation.

Wu, S Q; Hartemann, F V

2011-10-04T23:59:59.000Z

220

Thermophysical Property Measurements Under Reduced Gravity ...  

Science Conference Proceedings (OSTI)

Presentation Title, Thermophysical Property Measurements Under Reduced Gravity Conditions: Evolution and Status of theThermoLab Project. Author(s), H-J

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


221

Intergranular Thermal Residual Strain in Rolled and Texture-free ? ...  

Science Conference Proceedings (OSTI)

In this study, the intergranular thermal residual strains are determined from ... rolled and texture-free ?-uranium measured by neutron diffraction during cooling.

222

Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet...  

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

Thermophysical Properties In our Thermal Storage Materials Laboratory, we use a variety of instruments to measure the thermophysical properties of heat transfer fluids and storage...

223

Early maturation processes in coal.1 Part 1: Pyrolysis mass balances and structural evolution of coalified wood from the2  

E-Print Network (OSTI)

Early maturation processes in coal.1 Part 1: Pyrolysis mass balances and structural evolution of coalified wood from the2 Morwell Brown Coal seam3 4 Elodie Salmon a, c , Françoise Behar a , François Lorant force21 field to simulate the thermal stress. The Morwell coal has been selected to study the thermal22

Paris-Sud XI, Université de

224

Thermal contact resistance  

E-Print Network (OSTI)

This work deals with phenomena of thermal resistance for metallic surfaces in contact. The main concern of the work is to develop reliable and practical methods for prediction of the thermal contact resistance for various ...

Mikic, B. B.

1966-01-01T23:59:59.000Z

225

Definition: British thermal unit | Open Energy Information  

Open Energy Info (EERE)

thermal unit thermal unit Jump to: navigation, search Dictionary.png British thermal unit The amount of heat required to raise the temperature of one pound of water one degree Fahrenheit; often used as a unit of measure for the energy content of fuels.[1][2] View on Wikipedia Wikipedia Definition The British thermal unit (BTU or Btu) is a traditional unit of energy equal to about 1055 joules. It is the amount of energy needed to cool or heat one pound of water by one degree Fahrenheit. In scientific contexts the BTU has largely been replaced by the SI unit of energy, the joule. The unit is most often used as a measure of power (as BTU/h) in the power, steam generation, heating, and air conditioning industries, and also as a measure of agricultural energy production (BTU/kg). It is still used

226

Quantum Mechanics Measurements, Mutually  

E-Print Network (OSTI)

Quantum Mechanics Measurements, Mutually Unbiased Bases and Finite Geometry Or why six is the first) #12;Quantum Mechanics for Dummies Finite dimensional quantum states are represented by trace one,1 -icS1,1[ ] #12;Quantum systems evolve and are measured. The evolution of a quantum system using

Gruner, Daniel S.

227

Thermal and Electrical Transport in Oxide Heterostructures  

E-Print Network (OSTI)

of thermal conductivity . . . . . . . . . . . . . . . .4.4 Thermal transport in2.3.2 Thermal transport . . . . . . . . . . . . . . . .

Ravichandran, Jayakanth

2011-01-01T23:59:59.000Z

228

Thermal Spray Coatings  

Science Conference Proceedings (OSTI)

Table 35   Thermal spray coatings used for hardfacing applications...piston ring (internal combustion);

229

Plasma-Thermal Synthesis  

INLs Plasma-Thermal Synthesis process improves the conversion process for natural gas into liquid hydrocarbon fuels.

230

Ocean Thermal Energy Conversion  

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

A process called ocean thermal energy conversion (OTEC) uses the heat energy stored in the Earth's oceans to generate electricity.

231

Nanocomposite Thermal Spray Coatings.  

Science Conference Proceedings (OSTI)

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

232

Thermal Management of Solar Cells  

E-Print Network (OSTI)

phonon transmission and interface thermal conductance acrossF. Miao, et al. , "Superior Thermal Conductivity of Single-Advanced Materials for Thermal Management of Electronic

Saadah, Mohammed Ahmed

2013-01-01T23:59:59.000Z

233

Effect of heat treatment temperature on binder thermal conductivities  

SciTech Connect

The effect of heat treatment on the thermal conductivities of a pitch and a polyfurfuryl alcohol binder residue was investigated. Graphites specially prepared with these two binders were used for the experiments. Measured thermal conductivities were treated in terms of a two-component system, and the binder thermal conductivities were calculated. Both binder residues showed increased thermal conductivity with increased heat treatment temperature. (auth)

Wagner, P.

1975-12-01T23:59:59.000Z

234

Stability of thermal modes in cool prominence plasmas  

E-Print Network (OSTI)

Context: Magnetohydrodynamic thermal modes may play an important role in the formation, plasma condensation, and evolution of solar prominences. Unstable thermal modes due to unbalance between radiative losses and heating can lead to rapid plasma cooling and condensation. An accurate description of the radiative loss function is therefore crucial for this process. Aims: We study the stability of thermal modes in unbounded and uniform plasmas with properties akin to those in solar prominences. Effects due to partial ionization are taken into account. Three different parametrizations of the radiative loss function are used. Methods: By means of a normal mode analysis, we investigate linear nonadiabatic perturbations superimposed on the equilibrium state. We find an approximate instability criterion for thermal modes, while the exact linear growth rate is obtained by numerically solving the general dispersion relation. The stability of thermal disturbances is compared for the three different loss functions consi...

Soler, Roberto; Parenti, Susanna

2012-01-01T23:59:59.000Z

235

Halo Star Evolution  

E-Print Network (OSTI)

In this review, I will discuss a few problems which point to the need for improved stellar evolution models of halo stars. Current stellar evolution models do not match the observed $^7$Li abundance patterns, suggesting that the input physics and/or the assumptions used in constructing the models are in need of revision. It appears that all halo stars have suffered some $^7$Li depletion, implying that the primordial $^7$Li abundance is higher than that presently observed in hot halo stars. Observations of abundances of various elements in globular cluster giant branch stars have suggested for some time now that some form of deep mixing, which is not present in theoretical models, occurs in halo stars. The driving mechanism for this mixing, and its incorporation into stellar models remain one of the key problems in stellar modeling. Current theoretical isochrones are able to provide a good match to observed colour-magnitude diagrams. However, there is some evidence that the theoretical luminosity functions are in disagreement with observations. This is an area which requires further study, as it suggests that the relative main sequence/giant branch lifetimes predicted by the models are incorrect. A discussion of some of the uncertainties involved in determining the ages of globular clusters is presented. The absolute ages of globular clusters provide a lower bound to the age of the universe, and so are of great interest to cosmologists. Unfortunately, present uncertainties in stellar models lead to a rather large range in the inferred ages of globular clusters of 11 -- 18 Gyr.

Brian Chaboyer

1995-09-08T23:59:59.000Z

236

Probing the evolution of antiferromagnetism in multiferroics  

SciTech Connect

This study delineates the evolution of magnetic order in epitaxial films of the room-temperature multiferroic BiFeO3 system. Using angle- and temperature-dependent dichroic measurements and spectromicroscopy, we have observed that the antiferromagnetic order in the model multiferroic BiFeO3 evolves systematically as a function of thickness and strain. Lattice-mismatch-induced strain is found to break the easy-plane magnetic symmetry of the bulk and leads to an easy axis of magnetization which can be controlled through strain. Understanding the evolution of magnetic structure and how to manipulate the magnetism in this model multiferroic has significant implications for utilization of such magnetoelectric materials in future applications.

Holcomb, M.; Martin, L.; Scholl, A.; He, Q.; Yu, P.; Yang, C.-H.; Yang, S.; Glans, P.-A.; Valvidares, M.; Huijben, M.; Kortright, J.; Guo,, J.; Chu, Y.-H.; Ramesh, R.

2010-06-09T23:59:59.000Z

237

Debris Thermal Hydraulics Modeling of QUENCH Experiments  

SciTech Connect

Porous debris formation and behavior in QUENCH experiments (QUENCH-02, QUENCH-03) plays a considerable role and its adequate modeling is important for thermal analysis. This work is aimed to the development of a numerical module which is able to model thermal hydraulics and heat transfer phenomena occurring during the high-temperature stage of severe accident with the formation of debris region and molten pool. The original approach for debris evolution is developed from classical principles using a set of parameters including debris porosity; average particle diameter; temperatures and mass fractions of solid, liquid and gas phases; specific interface areas between different phases; effective thermal conductivity of each phase, including radiative heat conductivity; mass and energy fluxes through the interfaces. The debris model is based on the system of continuity, momentum and energy conservation equations, which consider the dynamics of volume-averaged velocities and temperatures of fluid, solid and gaseous phases of porous debris. The different mechanisms of debris formation are considered, including degradation of fuel rods according to temperature criteria, taking into consideration some correlations between rod layers thicknesses; degradation of rod layer structure due to thermal expansion of melted materials inside intact rod cladding; debris formation due to sharp temperature drop of previously melted material due to reflood; and transition to debris of material from elements lying above. The porous debris model was implemented to best estimate numerical code RATEG/SVECHA/HEFEST developed for modeling thermal hydraulics and severe accident phenomena in a reactor. The model is used for calculation of QUENCH experiments. The results obtained by the model are compared to experimental data concerning different aspects of thermal behavior: thermal hydraulics of porous debris, radiative heat transfer in a porous medium, the generalized melting and refreezing behavior of materials, hydrogen production. (authors)

Kisselev, Arcadi E.; Kobelev, Gennadii V.; Strizhov, Valerii F.; Vasiliev, Alexander D. [Nuclear Safety Institute - IBRAE, 52 Bolshaya Tulskaya Ulitsa, Moscow, 113191 (Russian Federation)

2006-07-01T23:59:59.000Z

238

Building Energy Software Tools Directory: Thermal Comfort  

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

Thermal Comfort Thermal Comfort logo. Provides a user-friendly interface for calculating thermal comfort parameters and making thermal comfort predictions using several thermal...

239

Satellite-based Microwave Observations of Tropopause-Level Thermal Anomalies: Qualitative Applications in Extratropical Cyclone Events  

Science Conference Proceedings (OSTI)

The evolution of upper-tropospheric thermal patterns associated with extratropical cyclone events is often not well represented by the conventional observational network, especially in marine situations. In this paper, a potential tool for ...

Christopher S. Velden

1992-12-01T23:59:59.000Z

240

Thermal well-test method  

DOE Patents (OSTI)

A well-test method involving injection of hot (or cold) water into a groundwater aquifer, or injecting cold water into a geothermal reservoir is disclosed. By making temperature measurements at various depths in one or more observation wells, certain properties of the aquifer are determined. These properties, not obtainable from conventional well test procedures, include the permeability anisotropy, and layering in the aquifer, and in-situ thermal properties. The temperature measurements at various depths are obtained from thermistors mounted in the observation wells.

Tsang, C.F.; Doughty, C.A.

1984-02-24T23:59:59.000Z

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


241

THERMAL CONDUCTIVITY ANALYSIS OF GASES  

DOE Patents (OSTI)

This patent describes apparatus for the quantitative analysis of a gaseous mixture at subatmospheric pressure by measurement of its thermal conductivity. A heated wire forms one leg of a bridge circuit, while the gas under test is passed about the wire at a constant rate. The bridge unbalance will be a measure of the change in composition of the gas, if compensation is made for the effect due to gas pressure change. The apparatus provides a voltage varying with fluctuations of pressure in series with the indicating device placed across the bridge, to counterbalance the voltage change caused by fluctuations in the pressure of the gaseous mixture.

Clark, W.J.

1949-06-01T23:59:59.000Z

242

Thermal decomposition of mercuric sulfide  

Science Conference Proceedings (OSTI)

The rate of thermal decomposition of mercuric sulfide (HgS) has been measured at temperatures from 265 to 345 C. These data have been analyzed using a first-order chemical reaction model for the time dependence of the reaction and the Arrhenius equation for the temperature dependence of the rate constant. Using this information, the activation energy for the reaction was found to be 55 kcal/mol. Significant reaction vessel surface effects obscured the functional form of the time dependence of the initial portion of the reaction. The data and the resulting time-temperature reaction-rate model were used to predict the decomposition rate of HgS as a function of time and temperature in thermal treatment systems. Data from large-scale thermal treatment studies already completed were interpreted in terms of the results of this study. While the data from the large-scale thermal treatment studies were consistent with the data from this report, mass transport effects may have contributed to the residual amount of mercury which remained in the soil after most of the large-scale runs.

Leckey, J.H.; Nulf, L.E.

1994-10-28T23:59:59.000Z

243

Thermal Stability of Li-Ion Cells  

DOE Green Energy (OSTI)

The thermal stability of Li-ion cells with intercalating carbon anodes and metal oxide cathodes was measured as a function of state of charge and temperature for two advanced cell chemistries. Cells of the 18650 design with Li{sub x}CoO{sub 2} cathodes (commercial SONY cells) and Li{sub x}Ni{sub 0.8}Co{sub 0.2}O{sub 2} cathodes were measured for thermal reactivity in the open circuit cell condition. Accelerating rate calorimetry (ARC) was used to measure cell thermal runaway as a function of state of charge (SOC). Microcalorimetry was used to measure the time dependence of heat generating side reactions also as a function of SOC. Components of cells were measured using differential scanning calorimetry (DSC) to study the thermal reactivity of the individual electrodes to determine the temperature regimes and conditions of the major thermal reactions. Thermal decomposition of the SEI layer at the anodes was identified as the initiating source for thermal runaway. The cells with Li{sub x}CoO{sub 2} cathodes showed greater sensitivity to SOC and higher accelerating heating rates than seen for the cells with Li{sub x}Ni{sub 0.8}Co{sub 0.2}O{sub 2}cathodes. Lower temperature reactions starting as low as 40 C were also observed that were SOC dependent but not accelerating. These reactions were also measured in the microcalorimeter and observed to decay over time with a power-law dependence and are believed to result in irreversible capacity loss in the cells.

ROTH,EMANUEL P.

1999-09-17T23:59:59.000Z

244

Radiolytic evolution of gases from Z-9 soils  

DOE Green Energy (OSTI)

The total gas evolution rate was correlated with the plutonium and combined moisture and organic soil content. The maximum measured gas evolution rate was 1.3 x 10/sup -6/ gram-mole/hour - gram of plutonium. The major components of the evolved gas were determined to be 49.5 mole percent, (M%) nitrogen, 23.3 M% hydrogen, 14.1 M% oxygen and 13.1 M% carbon dioxide. This composition was determined from gas evolved by water-rich soil. Soils which are rich in organics may evolve gas with less oxygen. The data established the magnitude of the hydrogen evolution problem. Evolution of both oxygen and hydrogen means that the gas mixture will remain within the explosive range, once the lower explosion limit is exceeded.

Pajunen, A. L.

1977-07-01T23:59:59.000Z

245

Gas evolution from geopressured brines  

DOE Green Energy (OSTI)

The process of gas evolution from geopressured brine is examined using as a basis the many past studies of gas evolution from liquids in porous media. A discussion of a number of speculations that have been made concerning gas evolution from geopressured brines is provided. According to one, rapid pressure reduction will cause methane gas to evolve as when one opens a champagne bottle. It has been further speculated that evolved methane gas would migrate up to form an easily producible cap. As a result of detailed analyses, it can be concluded that methane gas evolution from geopressured brines is far too small to ever form a connected gas saturation except very near to the producing well. Thus, no significant gas cap could ever form. Because of the very low solubility of methaned in brine, the process of methane gas evolution is not at all analogous to evolution of carbon dioxide from champagne. A number of other speculations and questions on gas evolution are analyzed, and procedures for completing wells and testing geopressured brine reservoirs are discussed, with the conclusion that presently used procedures will provide adequate data to enable a good evaluation of this resource.

Matthews, C.S.

1980-06-01T23:59:59.000Z

246

Catalytic thermal barrier coatings  

Science Conference Proceedings (OSTI)

A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

Kulkarni, Anand A. (Orlando, FL); Campbell, Christian X. (Orlando, FL); Subramanian, Ramesh (Oviedo, FL)

2009-06-02T23:59:59.000Z

247

Evolution Securities Ltd formerly Evolution Beeson Gregory | Open Energy  

Open Energy Info (EERE)

Securities Ltd formerly Evolution Beeson Gregory Securities Ltd formerly Evolution Beeson Gregory Jump to: navigation, search Name Evolution Securities Ltd (formerly Evolution Beeson Gregory) Place London, United Kingdom Zip EC2V 7AN Product Evolution Securities is the investment banking business of Evolution Group plc providing equity research, institutional sales and trading and corporate finance advice. Coordinates 51.506325°, -0.127144° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.506325,"lon":-0.127144,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

248

Thermally Conductive Graphite Foam  

oriented graphite planes, similar to high performance carbon fibers, which have been estimated to exhibit a thermal conductivity greater than 1700 ...

249

Thermal Barrier Coatings  

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

Thermal Barrier Coatings Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implementing United States...

250

Advanced thermally stable jet fuels  

Science Conference Proceedings (OSTI)

The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume (Sections 1 through 5).

Schobert, H.H.

1999-01-31T23:59:59.000Z

251

Preparation and Thermal Characterization of Carbon Nanotubes-Based Composites for Applications in Electronics Packaging  

Science Conference Proceedings (OSTI)

The thermal resistance of nanocomposite layers formed by Single Wall Carbon Nanotubes (SWCNT) dispersed in epoxy resins has been measured under conditions similar to the ones used to dissipate heat in microelettronic devices. Thevariation of thermal ... Keywords: Carbon Nanotubes, Thermal Management, Epoxy Resin, Nanocomposite, TIM, Thermal Interface Materials

Francesco Toschi; Emanuela Tamburri; Valeria Guglielmotti; Maria Letizia Terranova; Andrea Reale; Aldo Di Carlo; Daniele Passeri; Marco Rossi; Carlo Falessi; Annamaria Fiorello; Roberta Buttiglione

2008-02-01T23:59:59.000Z

252

Thermal instability in the collisionally cooled gas  

E-Print Network (OSTI)

We have presented the non-equilibrium (time-dependent) cooling rate and ionization state calculations for a gas behind shock waves with $v \\sim 50-150$ km s$^{-1}$ ($T_s \\sim 0.5 - 6\\times 10^5$ K). Such shock waves do not lead to the radiative precursor formation, i.e. the thermal evolution of a gas behind the shock waves are controlled by collisions only. We have found that the cooling rate in a gas behind the shock waves with $v \\sim 50-120$ km s$^{-1}$ ($T_s \\sim 0.5 - 3\\times 10^5$ K) differs considerably from the cooling rate for a gas cooled from $T = 10^8$ K. It is well-known that a gas cooled from $T = 10^8$ K is thermally unstable for isobaric and isochoric perturbations at $T \\simgt 2\\times 10^4$ K. We have studied the thermal instability in a collisionally controlled gas for shock waves with $v \\sim 50-150$ km s$^{-1}$. We have found that the temperature range, where the postshock gas is thermally unstable, is significantly modified and depends on both gas metallicity and ionic composition of a ga...

Vasiliev, Evgenii O

2011-01-01T23:59:59.000Z

253

GALAXY EVOLUTION FROM 'DIS' INTEGRATED LIGHT  

SciTech Connect

Masking the horizontal branch and giant stars allows unambiguous measurements of mean age and metallicity in simple old stellar populations from metal and hydrogen line strengths. Billion year resolution is possible in the luminous halos of early-type galaxies, constraining formation models. Most of the nuisance parameters in stellar evolution are avoided by isolating the main sequence for analysis. The initial mass function and s-process element diagnostics may also be accessible. Integral field spectrographs have a significant advantage for this work, which is confusion limited by the presence of bright stars in medium to high surface brightness applications.

Mould, Jeremy, E-mail: jmould@swin.edu.au [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia)

2012-08-10T23:59:59.000Z

254

Variable pressure thermal insulating jacket  

DOE Patents (OSTI)

A device for controlled insulation of a thermal device. The device includes a thermal jacket with a closed volume able to be evacuated to form an insulating jacket around the thermal source. A getter material is in communcation with the closed volume of the thermal jacket. The getter material can absorb and desorb a control gas to control gas pressure in the volume of the thermal jacket to control thermal conductivity in the thermal jacket.

Nelson, Paul A. (Wheaton, IL); Malecha, Richard F. (Naperville, IL); Chilenskas, Albert A. (Chicago, IL)

1994-01-01T23:59:59.000Z

255

Variable pressure thermal insulating jacket  

DOE Patents (OSTI)

A device for controlled insulation of a thermal device is disclosed. The device includes a thermal jacket with a closed volume able to be evacuated to form an insulating jacket around the thermal source. A getter material is in communication with the closed volume of the thermal jacket. The getter material can absorb and desorb a control gas to control gas pressure in the volume of the thermal jacket to control thermal conductivity in the thermal jacket. 10 figs.

Nelson, P.A.; Malecha, R.F.; Chilenskas, A.A.

1994-09-20T23:59:59.000Z

256

Thermal Emission from Gamma-Ray Bursts  

E-Print Network (OSTI)

In recent years, there are increasing evidence for a thermal emission component that accompanies the overall non-thermal spectra of the prompt emission phase in GRBs. Both the temperature and flux of the thermal emission show a well defined temporal behavior, a broken power law in time. The temperature is nearly constant during the first few seconds, afterwards it decays with power law index alpha ~0.7. The thermal flux also decays at late times as a power law with index beta ~2.1. This behavior is very ubiquitous, and was observed in a sample currently containing 32 BATSE bursts. These results are naturally explained by considering emission from the photosphere. The photosphere of a relativistically expanding plasma wind strongly depends on the angle to the line of sight, theta. As a result, thermal emission can be seen after tens of seconds. By introducing probability density function P(r,theta) of a thermal photon to escape the plasma at radius r and angle theta, the late time behavior of the flux can be reproduced analytically. During the propagation below the photosphere, thermal photons lose energy as a result of the slight misalignment of the scattering electrons velocity vectors, which leads to photon comoving energy decay epsilon'(r)~r^{-2/3}. This in turn can explain the decay of the temperature observed at late times. Finally, I show that understanding the thermal emission is essential in understanding the high energy, non-thermal spectra. Moreover, thermal emission can be used to directly measure the Lorentz factor of the flow and the initial jet radius.

Asaf Pe'er

2008-09-04T23:59:59.000Z

257

Solar Thermal Demonstration Project  

SciTech Connect

HVAC Retrofit and Energy Efficiency Upgrades at Clark High School, Las Vegas, Nevada The overall objectives of this project are to increase usage of alternative/renewable fuels, create a better and more reliable learning environment for the students, and reduce energy costs. Utilizing the grant resources and local bond revenues, the District proposes to reduce electricity consumption by installing within the existing limited space, one principal energy efficient 100 ton adsorption chiller working in concert with two 500 ton electric chillers. The main heating source will be primarily from low nitrogen oxide (NOX), high efficiency natural gas fired boilers. With the use of this type of chiller, the electric power and cost requirements will be greatly reduced. To provide cooling to the information technology centers and equipment rooms of the school during off-peak hours, the District will install water source heat pumps. In another measure to reduce the cooling requirements at Clark High School, the District will replace single pane glass and metal panels with ??Kalwall?? building panels. An added feature of the ??Kalwall? system is that it will allow for natural day lighting in the student center. This system will significantly reduce thermal heat/cooling loss and control solar heat gain, thus delivering significant savings in heating ventilation and air conditioning (HVAC) costs.

Biesinger, K.; Cuppett, D.; Dyer, D.

2012-01-30T23:59:59.000Z

258

A Numerical Investigation of Squall Lines. Part II: The Mechanics of Evolution  

Science Conference Proceedings (OSTI)

The physical processes involved in the evolution of the model squall line presented in Part I of this study are examined. It is found that both the thermal and dynamic effects are important in the development of the midlevel meso-?-scale low ...

Kit Kong Szeto; Han-Ru Cho

1994-02-01T23:59:59.000Z

259

Chemical evolution with radial mixing  

E-Print Network (OSTI)

Models of the chemical evolution of our Galaxy are extended to include radial migration of stars and flow of gas through the disc. The models track the production of both iron and alpha elements. A model is chosen that provides an excellent fit to the metallicity distribution of stars in the Geneva-Copenhagen survey (GCS) of the solar neighbourhood, and a good fit to the local Hess diagram. The model provides a good fit to the distribution of GCS stars in the age-metallicity plane although this plane was not used in the fitting process. Although this model's star-formation rate is monotonic declining, its disc naturally splits into an alpha-enhanced thick disc and a normal thin disc. In particular the model's distribution of stars in the ([O/Fe],[Fe/H]) plane resembles that of Galactic stars in displaying a ridge line for each disc. The thin-disc's ridge line is entirely due to stellar migration and there is the characteristic variation of stellar angular momentum along it that has been noted by Haywood in survey data. Radial mixing of stellar populations with high sigma_z from inner regions of the disc to the solar neighbourhood provides a natural explanation of why measurements yield a steeper increase of sigma_z with age than predicted by theory. The metallicity gradient in the ISM is predicted to be steeper than in earlier models, but appears to be in good agreement with data for both our Galaxy and external galaxies. The models are inconsistent with a cutoff in the star-formation rate at low gas surface densities. The absolute magnitude of the disc is given as a function of time in several photometric bands, and radial colour profiles are plotted for representative times.

Ralph Schoenrich; James Binney

2008-09-17T23:59:59.000Z

260

Thermal protection apparatus  

DOE Patents (OSTI)

An apparatus which thermally protects sensitive components in tools used in a geothermal borehole. The apparatus comprises a Dewar within a housing. The Dewar contains heat pipes such as brass heat pipes for thermally conducting heat from heat sensitive components to a heat sink such as ice.

Bennett, Gloria A. (Los Alamos, NM); Elder, Michael G. (Los Alamos, NM); Kemme, Joseph E. (Albuquerque, NM)

1985-01-01T23:59:59.000Z

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


261

Thermal protection apparatus  

DOE Patents (OSTI)

The disclosure is directed to an apparatus for thermally protecting sensitive components in tools used in a geothermal borehole. The apparatus comprises a Dewar within a housing. The Dewar contains heat pipes such as brass heat pipes for thermally conducting heat from heat sensitive components such as electronics to a heat sink such as ice.

Bennett, G.A.; Elder, M.G.; Kemme, J.E.

1984-03-20T23:59:59.000Z

262

Thermal masses in leptogenesis  

E-Print Network (OSTI)

We investigate the validity of using thermal masses in the kinematics of final states in the decay rate of heavy neutrinos in leptogenesis calculations. We find that using thermal masses this way is a reasonable approximation, but corrections arise through quantum statistical distribution functions and leptonic quasiparticles.

Kiessig, Clemens P

2009-01-01T23:59:59.000Z

263

Thermal treatment wall  

DOE Patents (OSTI)

A thermal treatment wall emplaced to perform in-situ destruction of contaminants in groundwater. Thermal destruction of specific contaminants occurs by hydrous pyrolysis/oxidation at temperatures achievable by existing thermal remediation techniques (electrical heating or steam injection) in the presence of oxygen or soil mineral oxidants, such as MnO.sub.2. The thermal treatment wall can be installed in a variety of configurations depending on the specific objectives, and can be used for groundwater cleanup, wherein in-situ destruction of contaminants is carried out rather than extracting contaminated fluids to the surface, where they are to be cleaned. In addition, the thermal treatment wall can be used for both plume interdiction and near-wellhead in-situ groundwater treatment. Thus, this technique can be utilized for a variety of groundwater contamination problems.

Aines, Roger D. (Livermore, CA); Newmark, Robin L. (Livermore, CA); Knauss, Kevin G. (Livermore, CA)

2000-01-01T23:59:59.000Z

264

Solar thermal aircraft  

DOE Patents (OSTI)

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Bennett, Charles L. (Livermore, CA)

2007-09-18T23:59:59.000Z

265

Stability and Evolution of Supernova Fallback Disks  

E-Print Network (OSTI)

We show that thin accretion disks made of Carbon or Oxygen are subject to the same thermal ionization instability as Hydrogen and Helium disks. We argue that the instability applies to disks of any metal content. The relevance of the instability to supernova fallback disks probably means that their power-law evolution breaks down when they first become neutral. We construct simple analytical models for the viscous evolution of fallback disks to show that it is possible for these disks to become neutral when they are still young (ages of a few 10^3 to 10^4 years), compact in size (a few 10^9 cm to 10^11 cm) and generally accreting at sub-Eddington rates (Mdot ~ a few 10^14 - 10^18 g/s). Based on recent results on the nature of viscosity in the disks of close binaries, we argue that this time may also correspond to the end of the disk activity period. Indeed, in the absence of a significant source of viscosity in the neutral phase, the entire disk will likely turn to dust and become passive. We discuss various applications of the evolutionary model, including anomalous X-ray pulsars and young radio pulsars. Our analysis indicates that metal-rich fallback disks around newly-born neutron stars and black holes become neutral generally inside the tidal truncation radius (Roche limit) for planets, at \\~10^11 cm. Consequently, the efficiency of the planetary formation process in this context will mostly depend on the ability of the resulting disk of rocks to spread via collisions beyond the Roche limit. It appears easier for the merger product of a doubly degenerate binary, whether it is a massive white dwarf or a neutron star, to harbor planets because it can spread beyond the Roche limit before becoming neutral.[Abridged

Kristen Menou; Rosalba Perna; Lars Hernquist

2001-02-27T23:59:59.000Z

266

Thermally-related safety issues associated with thermal batteries.  

DOE Green Energy (OSTI)

Thermal batteries can experience thermal runaway under certain usage conditions. This can lead to safety issues for personnel and cause damage to associated test equipment if the battery thermally self destructs. This report discusses a number of thermal and design related issues that can lead to catastrophic destruction of thermal batteries under certain conditions. Contributing factors are identified and mitigating actions are presented to minimize or prevent undesirable thermal runaway.

Guidotti, Ronald Armand

2006-06-01T23:59:59.000Z

267

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

SciTech Connect

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

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

2013-01-01T23:59:59.000Z

268

Efficient thermal management for multiprocessor systems  

E-Print Network (OSTI)

2.2.4 Thermal Modeling . . . . . . . .63 Table 4.3: Thermal Hot Spots . . . . . . . . . . . . . .Performance-Efficient Thermal Management . . . . . . . . . .

Co?kun, Ay?e K?v?lc?m

2009-01-01T23:59:59.000Z

269

Cooling thermal storage  

Science Conference Proceedings (OSTI)

This article gives some overall guidelines for successful operation of cooling thermal storage installations. Electric utilities use rates and other incentives to encourage thermal storage, which not only reduces their system peaks but also transfers a portion of their load from expensive daytime inefficient peaking plants to less expensive nighttime base load high efficiency coal and nuclear plants. There are hundreds of thermal storage installations around the country. Some of these are very successful; others have failed to achieve all of their predicted benefits because application considerations were not properly addressed.

Gatley, D.P.

1987-04-01T23:59:59.000Z

270

Multilayer thermal barrier coating systems  

DOE Patents (OSTI)

The present invention generally describes multilayer thermal barrier coating systems and methods of making the multilayer thermal barrier coating systems. The thermal barrier coating systems comprise a first ceramic layer, a second ceramic layer, a thermally grown oxide layer, a metallic bond coating layer and a substrate. The thermal barrier coating systems have improved high temperature thermal and chemical stability for use in gas turbine applications.

Vance, Steven J. (Orlando, FL); Goedjen, John G. (Oviedo, FL); Sabol, Stephen M. (Orlando, FL); Sloan, Kelly M. (Longwood, FL)

2000-01-01T23:59:59.000Z

271

REACTOR GROUT THERMAL PROPERTIES  

DOE Green Energy (OSTI)

Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.

2011-01-28T23:59:59.000Z

272

Thermal insulations using vacuum panels  

DOE Patents (OSTI)

Thermal insulation vacuum panels are formed of an inner core of compressed low thermal conductivity powders enclosed by a ceramic/glass envelope evaluated to a low pressure.

Glicksman, Leon R. (Lynnfield, MA); Burke, Melissa S. (Pittsburgh, PA)

1991-07-16T23:59:59.000Z

273

Ocean Thermal | Open Energy Information  

Open Energy Info (EERE)

Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon Ocean Thermal Jump to: navigation, search TODO: Add description List of Ocean Thermal Incentives...

274

Comparison of Thermal Insulation Materials.  

E-Print Network (OSTI)

??This thesis is about comparing of different thermal insulation materials of different manufactures. In our days there are a lot of different thermal insulation materials (more)

Chaykovskiy, German

2010-01-01T23:59:59.000Z

275

Definition: Thermal energy | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Thermal energy Jump to: navigation, search Dictionary.png Thermal energy The kinetic energy associated with the random motions of the molecules of a material or object; often used interchangeably with the terms heat and heat energy. Measured in joules, calories, or Btu.[1][2][3] View on Wikipedia Wikipedia Definition Thermal energy is the part of the total potential energy and kinetic energy of an object or sample of matter that results in the system temperature. It is represented by the variable Q, and can be measured in Joules. This quantity may be difficult to determine or even meaningless unless the system has attained its temperature only through warming (heating), and not been subjected to work input or output, or any other

276

Integrability vs Quantum Thermalization  

E-Print Network (OSTI)

Non-integrability is often taken as a prerequisite for quantum thermalization. Still, a generally accepted definition of quantum integrability is lacking. With the basis in the driven Rabi model we discuss this careless usage of the term "integrability" in connection to quantum thermalization. The model would be classified as non-integrable according to the most commonly used definitions, for example, the only preserved quantity is the total energy. Despite this fact, a thorough analysis conjectures that the system will not thermalize. Thus, our findings suggest first of all (i) that care should be paid when linking non-integrability with thermalization, and secondly (ii) that the standardly used definitions for quantum integrability are unsatisfactory.

Jonas Larson

2013-04-12T23:59:59.000Z

277

Contact thermal lithography  

E-Print Network (OSTI)

Contact thermal lithography is a method for fabricating microscale patterns using heat transfer. In contrast to photolithography, where the minimum achievable feature size is proportional to the wavelength of light used ...

Schmidt, Aaron Jerome, 1979-

2004-01-01T23:59:59.000Z

278

Properties of Thermal Glueballs  

E-Print Network (OSTI)

We study the properties of the 0++ glueball at finite temperature using SU(3) quenched lattice QCD. We find a significant thermal effects near T_c. We perform the \\chi^2 fit analyses adopting two Ansaetze for the spectral function, i.e., the conventional narrow-peak Ansatz and an advanced Breit-Wigner Ansatz. The latter is an extension of the former, taking account of the appearance of the thermal width at T>0. We also perform the MEM analysis. These analyses indicate that the thermal effect on the glueball is a significant thermal-width broadening \\Gamma(T_c) \\sim 300 MeV together with a modest reduction in the peak center \\Delta\\omega_0(T_c) \\sim 100 MeV.

Noriyoshi Ishii; Hideo Suganuma

2003-12-27T23:59:59.000Z

279

Thermal springs of Wyoming  

SciTech Connect

This bulletin attempts, first, to provide a comprehensive inventory of the thermal springs of Wyoming; second, to explore the geologic and hydrologic factors producing these springs; and, third, to analyze the springs collectively as an indicator of the geothermal resources of the state. A general discussion of the state's geology and the mechanisms of thermal spring production, along with a brief comparison of Wyoming's springs with worldwide thermal features are included. A discussion of geothermal energy resources, a guide for visitors, and an analysis of the flora of Wyoming's springs follow the spring inventory. The listing and analysis of Wyoming's thermal springs are arranged alphabetically by county. Tabulated data are given on elevation, ownership, access, water temperature, and flow rate. Each spring system is described and its history, general characteristics and uses, geology, hydrology, and chemistry are discussed. (MHR)

Breckenridge, R.M.; Hinckley, B.S.

1978-01-01T23:59:59.000Z

280

Thermal springs of Wyoming  

DOE Green Energy (OSTI)

This bulletin attempts, first, to provide a comprehensive inventory of the thermal springs of Wyoming; second, to explore the geologic and hydrologic factors producing these springs; and, third, to analyze the springs collectively as an indicator of the geothermal resources of the state. A general discussion of the state's geology and the mechanisms of thermal spring production, along with a brief comparison of Wyoming's springs with worldwide thermal features are included. A discussion of geothermal energy resources, a guide for visitors, and an analysis of the flora of Wyoming's springs follow the spring inventory. The listing and analysis of Wyoming's thermal springs are arranged alphabetically by county. Tabulated data are given on elevation, ownership, access, water temperature, and flow rate. Each spring system is described and its history, general characteristics and uses, geology, hydrology, and chemistry are discussed. (MHR)

Breckenridge, R.M.; Hinckley, B.S.

1978-01-01T23:59:59.000Z

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


281

Solar Thermal Manufacturing Activities  

Reports and Publications (EIA)

This report, Solar Thermal Collector Manufacturing Activities, providesan overview and tables with historical data spanning 2000-2009. These tables willcorrespond to similar tables to be presented in the Renewable Energy Annual 2009 andare numbered accordingly.

Michele Simmons

2010-12-01T23:59:59.000Z

282

Thermal Modeling and Device Noise Properties of Three-Dimensional-SOI Technology  

E-Print Network (OSTI)

Thermal test structures and ring oscillators (ROs) are fabricated in 0.18-mum three-dimensional (3-D)-SOI technology. Measurements and electrothermal simulations show that thermal and parasitic effects due to 3-D packaging ...

Chen, Tze Wee

283

Adiabatic evolution under quantum control  

E-Print Network (OSTI)

One of the difficulties in adiabatic quantum computation is the limit on the computation time. Here we propose two schemes to speed-up the adiabatic evolution. To apply this controlled adiabatic evolution to adiabatic quantum computation, we design one of the schemes without any prior knowledge of the instantaneous eigenstates of the final Hamiltonian. Whereas in another scheme, the control is constructed with the instantaneous eigenstate that is the target state of the control. As an illustration, we study a two-level system driven by a time-dependent magnetic field under the control. The physics behind the control scheme is explained.

Wang, W; Yi, X X

2009-01-01T23:59:59.000Z

284

Texas Thermal Comfort Report  

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

thermal comfort thermal comfort Too often, the systems in our houses are both physically and intellectually inaccessible. In the SNAP House, HVAC components are integrated into the overall structure, and act as an experiential threshold between public and private spaces. They are located in a central, structural chase that supports the clerestory and gives the systems a functional presence within the interior. Each individual component is contained within a single chase

285

Photovoltaic-thermal collectors  

DOE Patents (OSTI)

A photovoltaic-thermal solar cell including a semiconductor body having antireflective top and bottom surfaces and coated on each said surface with a patterned electrode covering less than 10% of the surface area. A thermal-absorbing surface is spaced apart from the bottom surface of the semiconductor and a heat-exchange fluid is passed between the bottom surface and the heat-absorbing surface.

Cox, III, Charles H. (Carlisle, MA)

1984-04-24T23:59:59.000Z

286

Thermal Energy Storage  

Science Conference Proceedings (OSTI)

This Technology Brief provides an update on the current state of cool thermal energy storage systems (TES) for end-use applications. Because of its ability to shape energy use, TES is strategic technology that allows end-users to reduce their energy costs while simultaneously providing benefits for electric utilities through persistent peak demand reduction and peak shifting. In addition to discussing the concepts of thermal energy storage, the Brief discusses the current state of TES technologies and dr...

2008-12-16T23:59:59.000Z

287

Heat transfer through porous multiphase systems measurement, modelling and applications in printing of coated papers.  

E-Print Network (OSTI)

??This work examines the thermal transfer through porous media by means of measurement of the effective thermal conductivity and modelling of the structural parameters. While (more)

Gerstner, Philip

2010-01-01T23:59:59.000Z

288

Measuring Advances in HVAC Distribution System Design  

E-Print Network (OSTI)

Gabel and Andresen, HVAC Secondary Toolkil. Atlanta: ASHRAE,P_02 Measuring Advances in HVAC Distribution System Designdesign and operation of the HVAC thermal distribution system

Franconi, E.

2011-01-01T23:59:59.000Z

289

Noisy evolution of graph-state entanglement  

Science Conference Proceedings (OSTI)

A general method for the study of the entanglement evolution of graph states under the action of Pauli maps was recently proposed in Cavalcanti et al. [Phys. Rev. Lett. 103, 030502 (2009)]. This method is based on lower and upper bounds to the entanglement of the entire state as a function only of the state of a (typically) considerably smaller subsystem undergoing an effective noise process related to the original map. This provides a huge decrease in the size of the matrices involved in the calculation of entanglement in these systems. In the present paper we elaborate on this method in detail and generalize it to other natural situations not described by Pauli maps. Specifically, for Pauli maps we introduce an explicit formula for the characterization of the resulting effective noise. Beyond Pauli maps, we show that the same ideas can be applied to the case of thermal reservoirs at arbitrary temperature. In the latter case, we discuss how to optimize the bounds as a function of the noise strength. We illustrate our ideas with explicit exemplary results for several different graphs and particular decoherence processes. The limitations of the method are also discussed.

Aolita, L.; Dhara, C. [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, E-08860 Castelldefels, Barcelona (Spain); Cavalcanti, D. [Centre for Quantum Technologies, University of Singapore (Singapore); Chaves, R.; Davidovich, L. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21941-972 Rio de Janeiro, RJ (Brazil); Acin, A. [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, E-08860 Castelldefels, Barcelona (Spain); ICREA-Institucio Catalana de Recerca i Estudis Avancats, Lluis Companys 23, E-08010 Barcelona (Spain)

2010-09-15T23:59:59.000Z

290

On the focusing of thermal images  

Science Conference Proceedings (OSTI)

In this paper we present a new thermographic image database, suitable for the analysis of automatic focusing measures. This database contains the images of 10 scenes, each of which is represented once for each of 96 different focus positions. Using this ... Keywords: Database, Focus, Image quality, Thermal image

Marcos Faundez-Zanuy; Ji? Mekyska; Virginia Espinosa-Dur

2011-08-01T23:59:59.000Z

291

Thermal Stability of Chelated Indium Activable Tracers  

SciTech Connect

The thermal stability of indium tracer chelated with organic ligands ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) was measured for reservoir temperatures of 150, 200, and 240 C. Measurements of the soluble indium concentration was made as a function of time by neutron activation analysis. From the data, approximate thermal decomposition rates were estimated. At 150 C, both chelated tracers were stable over the experimental period of 20 days. At 200 C, the InEDTA concentration remained constant for 16 days, after which the thermal decomposition occurred at a measured rate constant of k = 0.09 d{sup -1}. The thermal decomposition of InNTA at 200 C showed a first order reaction with a measured rate constant of k = 0.16 d{sup -1}. At 240 C, both indium chelated tracers showed rapid decomposition with rate constants greater than 1.8 d{sup -1}. The data indicate that for geothermal reservoir with temperatures up to about 200 C, indium chelated tracers can be used effectively for transit times of at least 20 days. These experiments were run without reservoir rock media, and do not account for concomitant loss of indium tracer by adsorption processes.

Chrysikopoulos, Costas; Kruger, Paul

1986-01-21T23:59:59.000Z

292

Thermal conductivity modeling of building faade materials  

Science Conference Proceedings (OSTI)

An experimental research has been conducted to assess the thermo-physical properties of three building materials in both dry and moist state: beech wood, autoclaved aerated concrete and brick. The objectives of the paper envisage the measurement of the ... Keywords: building materials, contact temperature, determining method, finite element, numerical modeling, thermal conductivity

Monica Chereches; Nelu-Cristian Chereches; Catalin Popovici

2010-04-01T23:59:59.000Z

293

MODELING THE RED SEQUENCE: HIERARCHICAL GROWTH YET SLOW LUMINOSITY EVOLUTION  

SciTech Connect

We explore the effects of mergers on the evolution of massive early-type galaxies by modeling the evolution of their stellar populations in a hierarchical context. We investigate how a realistic red sequence population set up by z {approx} 1 evolves under different assumptions for the merger and star formation histories, comparing changes in color, luminosity, and mass. The purely passive fading of existing red sequence galaxies, with no further mergers or star formation, results in dramatic changes at the bright end of the luminosity function and color-magnitude relation. Without mergers there is too much evolution in luminosity at a fixed space density compared to observations. The change in color and magnitude at a fixed mass resembles that of a passively evolving population that formed relatively recently, at z {approx} 2. Mergers among the red sequence population ('dry mergers') occurring after z = 1 build up mass, counteracting the fading of the existing stellar populations to give smaller changes in both color and luminosity for massive galaxies. By allowing some galaxies to migrate from the blue cloud onto the red sequence after z = 1 through gas-rich mergers, younger stellar populations are added to the red sequence. This manifestation of the progenitor bias increases the scatter in age and results in even smaller changes in color and luminosity between z = 1 and z = 0 at a fixed mass. The resultant evolution appears much slower, resembling the passive evolution of a population that formed at high redshift (z {approx} 3-5), and is in closer agreement with observations. We conclude that measurements of the luminosity and color evolution alone are not sufficient to distinguish between the purely passive evolution of an old population and cosmologically motivated hierarchical growth, although these scenarios have very different implications for the mass growth of early-type galaxies over the last half of cosmic history.

Skelton, Rosalind E. [Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Somerville, Rachel S., E-mail: ros.skelton@yale.edu [Department of Physics and Astronomy, Rutgers, State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States)

2012-07-01T23:59:59.000Z

294

Large-scale magnetic fields, curvature fluctuations and the thermal history of the Universe  

E-Print Network (OSTI)

It is shown that gravitating magnetic fields affect the evolution of curvature perturbations in a way that is reminiscent of a pristine non-adiabatic pressure fluctuation. The gauge-invariant evolution of curvature perturbations is used to constrain the magnetic power spectrum. Depending on the essential features of the thermodynamic history of the Universe, the explicit derivation of the bound is modified. The theoretical uncertainty in the constraints on the magnetic energy spectrum is assessed by comparing the results obtained in the case of the conventional thermal history with the estimates stemming from less conventional (but phenomenologically allowed) post-inflationary evolutions.

Massimo Giovannini

2007-07-05T23:59:59.000Z

295

Thermal Performance Engineer's Handbook: Introduction to Thermal Performance  

Science Conference Proceedings (OSTI)

The two-volume Thermal Performance Engineer Handbook will assist thermal performance engineers in identifying and investigating the cause of megawatt (MWe) losses as well as in proposing new ways to increase MWe output. Volume 1 contains a thermal performance primer to provide a brief review of thermodynamic principles involved in the stream power plant thermal cycle. The primer also contains brief descriptions of the equipment and systems in the cycle that can be sources of thermal losses. Also in Volum...

1998-04-01T23:59:59.000Z

296

The Annual Evolution of Geostrophic Flow in the Gulf of Maine: 19861987  

Science Conference Proceedings (OSTI)

The annual evolution of the geostrophic flow structure in the Gulf of Maine was studied with a combined set of moored pressure time-series measurements and five hydrographic surveys from August 1986 through September 1987. A series of quasi-...

Wendell S. Brown; James D. Irish

1992-05-01T23:59:59.000Z

297

Evolution of the Southern Hemisphere Subpolar Middle Atmosphere during Summer and Autumn  

Science Conference Proceedings (OSTI)

The evolution of zonal wind and zonal wavenumber one (wave 1) in the Southern Hemisphere subpolar middle atmosphere is described for the period December 1978May 1979 using temperature and ozone measurements from the Limb Infrared Monitor of the ...

T. Miles; W. L. Grose; E. E. Remsberg; G. Lingenfelser

1994-03-01T23:59:59.000Z

298

Multiparameter Radar and Aircraft Study of Raindrop Spectral Evolution in Warm-based Clouds  

Science Conference Proceedings (OSTI)

Radar measurements of reflectivity differential reflectivity, and X-band (3-cm wavelength) specific attenuation are used to inter some microphysical characteristics of warm-based convective clouds with emphasis on raindrop spectral evolution. The ...

V. N. Bringi; D. A. Burrows; S. M. Menon

1991-06-01T23:59:59.000Z

299

Case Study of a Hailstorm in Colorado. Part I: Radar Echo Structure and Evolution  

Science Conference Proceedings (OSTI)

A detailed description is given of the morphology and evolution of a moderate hailstorm in terms primarily of quantitative S-band reflectivity factor measurements. During the early phase of the storm's life its movement was strongly influenced by ...

G. Brant Foote; Charles G. Wade

1982-12-01T23:59:59.000Z

300

Characterization of Thermal Properties of Depleted Uranium Metal Microspheres  

E-Print Network (OSTI)

Nuclear fuel comes in many forms; oxide fuel is the most commonly used in current reactor systems while metal fuel is a promising fuel type for future reactors due to neutronic performance and increased thermal conductivity. As a key heat transfer parameter, thermal conductivity describes the heat transport properties of a material based upon the density, specific heat, and thermal diffusivity. A materials ability to transport thermal energy through its structure is a measurable property known as thermal diffusivity; the units for thermal diffusivity are given in area per unit time (e.g., m2/s). Current measurement methods for thermal diffusivity include LASER (or light) Flash Analysis and the hot-wire method. This study examines an approach that combines these previous two methods to characterize the diffusivity of a packed bed of microspheres of depleted uranium (DU) metal, which have a nominal diameter of 250 micrometers. The new apparatus is designated as the Crucible Heater Test Assembly (CHTA), and it induces a radial transient across a packed sample of microspheres then monitors the temperature profile using an array of thermocouples located at different distances from the source of the thermal transient. From the thermocouple data and an accurate time log, the thermal diffusivity of the sample may be calculated. Results indicate that DU microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer. At 500C, the thermal conductivity of the DU microspheres was 0.431 13% W/m-K compared to approximately 32 W/m-K for solid uranium metal. Characterization of the developed apparatus revealed a method that may be useful for measuring the thermal diffusivity of powders and liquids.

Humrickhouse, Carissa Joy

2012-05-01T23:59:59.000Z

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

Thermal Management of Solar Cells  

E-Print Network (OSTI)

UNIVERSITY OF CALIFORNIA RIVERSIDE Thermal Management ofUniversity of California, Riverside Acknowledgments First, I

Saadah, Mohammed Ahmed

2013-01-01T23:59:59.000Z

302

Multilayer Nanoscale Thermal Barrier Coatings  

Science Conference Proceedings (OSTI)

Advanced high-efficiency gas turbines require thermal barrier coatings (TBCs) with low thermal conductivity and excellent thermal-cycling resistance. The multilayer TBC developed in this project has a thermal conductivity about half that of conventional TBCs and also rejects up to 70 percent of incoming radiant energy.

1999-05-26T23:59:59.000Z

303

Droplet evolution in expanding flow of warm dense matter  

E-Print Network (OSTI)

We propose a simple, self-consistent kinetic model for the evolution of a mixture of droplets and vapor expanding adiabatically in vacuum after rapid, almost isochoric heating. We study the evolution of the two-phase fluid at intermediate times between the molecular and the hydrodynamic scales, focusing on out-of-equilibrium and surface effects. We use the van der Waals equation of state as a test bed to implement our model and study the phenomenology of the upcoming second neutralized drift compression experiment (NDCX-II) at Lawrence Berkeley National Laboratory (LBNL) that uses ion beams for target heating.We find an approximate expression for the temperature difference between the droplets and the expanding gas and we check it with numerical calculations. The formula provides a useful criterion to distinguish the thermalized and nonthermalized regimes of expansion. In the thermalized case, the liquid fraction grows in a proportion that we estimate analytically, whereas, in case of too rapid expansion, a s...

Armijo, Julien; 10.1103/PhysRevE.83.051507

2011-01-01T23:59:59.000Z

304

Measuring the Evolution of Internet Peering Amogh Dhamdhere1  

E-Print Network (OSTI)

between two ASes changes relationship type, and produce a state transition diagram for each AS type. These state transition diagrams can be input to a model of macroscopic AS-level topology dynam- ics); this is expected, as they tend to peer aggressively to reduce upstream transit costs. We compare the growth rates

California at San Diego, University of

305

Solar-thermal technology  

DOE Green Energy (OSTI)

Solar-thermal technology converts sunlight into thermal energy. It stands alongside other solar technologies including solar-electric and photovoltaic technologies, both of which convert sunlight into electricity. Photovoltaic technology converts by direct conversion, and solar-electric converts by using sunlight`s thermal energy in thermodynamic power cycles. The numerous up-and-running solar energy systems prove solar-thermal technology works. But when is it cost-effective, and how can HVAC engineers and facility owners quickly identify cost-effective applications? This article addresses these questions by guiding the reader through the basics of solar-thermal technology. The first section provides an overview of today`s technology including discussions of collectors and typical systems. The next section presents an easy method for identifying potentially cost-effective applications. This section also identifies sources for obtaining more information on the technology--collector ratings and performance, solar manufacturers, and solar design and analysis tools. The article discusses only those collectors and systems that are most often used. Many others are on the market--the article does not, by omission, mean to infer that one is better than the other.

Bennett, C. [Sandia National Labs., Albuquerque, NM (United States)

1995-09-01T23:59:59.000Z

306

THE LONG-TERM EVOLUTION OF DOUBLE WHITE DWARF MERGERS  

SciTech Connect

In this paper, we present a model for the long-term evolution of the merger of two unequal mass C/O white dwarfs (WDs). After the dynamical phase of the merger, magnetic stresses rapidly redistribute angular momentum, leading to nearly solid-body rotation on a viscous timescale of 10{sup -4}-1 yr, long before significant cooling can occur. Due to heating during the dynamical and viscous phases, the less massive WD is transformed into a hot, slowly rotating, and radially extended envelope supported by thermal pressure. Following the viscous phase of evolution, the maximum temperature near the envelope base may already be high enough to begin off-center convective carbon burning. If not, Kelvin-Helmholtz contraction of the inner region of the envelope on a thermal timescale of 10{sup 3}-10{sup 4} yr compresses the base of the envelope, again yielding off-center burning. As a result, the long-term evolution of the merger remnant is similar to that seen in previous calculations: the burning shell diffuses inward over {approx}10{sup 4} yr, eventually yielding a high-mass O/Ne WD or a collapse to a neutron star, rather than a Type Ia supernova. During the cooling and shell-burning phases, the merger remnant radiates near the Eddington limit. Given the double WD merger rate of a few per 1000 yr, a few dozen of these {approx}10{sup 38} erg s{sup -1} sources should exist in a Milky Way type galaxy. While the end result is similar to that of previous studies, the physical picture and the dynamical state of the matter in our model differ from previous work. Furthermore, substantial remaining uncertainties related to the convective structure near the photosphere and mass loss during the thermal evolution may significantly affect our conclusions. Thus, future work within the context of the physical model presented here is required to better address the eventual fate of double WD mergers, including those for which one or both of the components is a He WD.

Shen, Ken J.; Kasen, Daniel [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Bildsten, Lars [Kavli Institute for Theoretical Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States); Quataert, Eliot, E-mail: kenshen@astro.berkeley.edu [Department of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)

2012-03-20T23:59:59.000Z

307

Thermal conductivity and other properties of cementitious grouts  

DOE Green Energy (OSTI)

The thermal conductivity and other properties cementitious grouts have been investigated in order to determine suitability of these materials for grouting vertical boreholes used with geothermal heat pumps. The roles of mix variables such as water/cement ratio, sand/cement ratio and superplasticizer dosage were measured. In addition to thermal conductivity, the cementitious grouts were also tested for bleeding, permeability, bond to HDPE pipe, shrinkage, coefficient of thermal expansion, exotherm, durability and environmental impact. This paper summarizes the results for selected grout mixes. Relatively high thermal conductivities were obtained and this leads to reduction in predicted bore length and installation costs. Improvements in shrinkage resistance and bonding were achieved.

Allan, M.

1998-08-01T23:59:59.000Z

308

THERMAL CONDUCTIVITY AND OTHER PROPERTIES OF CEMENTITIOUS GROUTS  

DOE Green Energy (OSTI)

The thermal conductivity and other properties cementitious grouts have been investigated in order to determine suitability of these materials for grouting vertical boreholes used with geothermal heat pumps. The roles of mix variables such as water/cement ratio, sand/cement ratio and superplasticizer dosage were measured. In addition to thermal conductivity, the cementitious grouts were also tested for bleeding, permeability, bond to HDPE pipe, shrinkage, coefficient of thermal expansion, exotherm, durability and environmental impact. This paper summarizes the results for selected grout mixes. Relatively high thermal conductivities were obtained and this leads to reduction in predicted bore length and installation costs. Improvements in shrinkage resistance and bonding were achieved.

ALLAN,M.

1998-05-01T23:59:59.000Z

309

Evolve: tool support for architecture evolution  

Science Conference Proceedings (OSTI)

Incremental change is intrinsic to both the initial development and subsequent evolution of large complex software systems. Evolve is a graphical design tool that captures this incremental change in the definition of software architecture. It ... Keywords: software architecture evolution

Andrew McVeigh; Jeff Kramer; Jeff Magee

2011-05-01T23:59:59.000Z

310

Article for thermal energy storage  

DOE Patents (OSTI)

A thermal energy storage composition is provided which is in the form of a gel. The composition includes a phase change material and silica particles, where the phase change material may comprise a linear alkyl hydrocarbon, water/urea, or water. The thermal energy storage composition has a high thermal conductivity, high thermal energy storage, and may be used in a variety of applications such as in thermal shipping containers and gel packs.

Salyer, Ival O. (Dayton, OH)

2000-06-27T23:59:59.000Z

311

Thermal characterization of Li-ion cells using calorimetric techniques  

DOE Green Energy (OSTI)

The thermal stability of Li-ion cells with intercalating carbon anodes and metal oxide cathodes was measured as a function of state of charge and temperature for two advanced cell chemistries. Cells of the 18650 design with Li{sub x}CoO{sub 2} cathodes (commercial Sony cells) and Li{sub x}Ni{sub 0.8}Co{sub 0.2}O{sub 2} cathodes were measured for thermal reactivity. Accelerating rate calorimetry (ARC) was used to measure cell thermal runaway as a function of state of charge (SOC), microcalorimetry was used to measure the time dependence of thermal output, and differential scanning calorimetry (DSC) was used to study the thermal reactivity of the individual components. Thermal decomposition of the anode solid electrolyte interphase (SEI) layer occurred at low temperatures and contributes to the initiation of thermal runaway. Low temperature reactions from 40 C--70 C were observed during the ARC runs that were SOC dependent. These reactions measured in the microcalorimeter decayed over time with power-law dependence and were highly sensitive to SOC and temperature. ARC runs of aged and cycled cells showed complete absence of these low-temperature reactions but showed abrupt exothermic spikes between 105--135 C. These results suggest that during aging the anode SEI layer is decomposing from a metastable state to a stable composition that is breaking down at elevated temperatures.

ROTH,EMANUEL P.

2000-05-31T23:59:59.000Z

312

Quantum Gibbs distribution from dynamical thermalization in classical nonlinear lattices  

E-Print Network (OSTI)

We study numerically time evolution in classical lattices with weak or moderate nonlinearity which leads to interactions between linear modes. Our results show that in a certain strength range a moderate nonlinearity generates a dynamical thermalization process which drives the system to the quantum Gibbs distribution of probabilities, or average oscillation amplitudes. The effective dynamical temperature of the lattice varies from large positive to large negative values depending on energy of initially excited modes. This quantum Gibbs distribution is drastically different from usually expected energy equipartition over linear modes corresponding to a regime of classical thermalization. Possible experimental observations of this dynamical thermalization are discussed for cold atoms in optical lattices, nonlinear photonic lattices and optical fiber arrays.

Leonardo Ermann; Dima L. Shepelyansky

2013-07-22T23:59:59.000Z

313

Guiding Architects in Selecting Architectural Evolution Alternatives  

SciTech Connect

Although there exist methods and tools to support architecture evolution, the derivation and evaluation of alternative evolution paths are realized manually. In this paper, we introduce an approach, where architecture specification is converted to a graph representation. Based on this representation, we automatically generate possible evolution paths, evalute quality attributes for different architecture configurations, and optimize the selection of a particular path accordingly. We illustrate our approach by modeling the software architecture evolution of a crisis management system.

Ciraci, Selim; Sozer, Hasan; Aksit, Mehmet

2011-09-09T23:59:59.000Z

314

Thermal insulated glazing unit  

SciTech Connect

An improved insulated glazing unit is provided which can attain about R5 to about R10 thermal performance at the center of the glass while having dimensions about the same as those of a conventional double glazed insulated glazing unit. An outer glazing and inner glazing are sealed to a spacer to form a gas impermeable space. One or more rigid, non-structural glazings are attached to the inside of the spacer to divide the space between the inner and outer glazings to provide insulating gaps between glazings of from about 0.20 inches to about 0.40 inches. One or more glazing surfaces facing each thermal gap are coated with a low emissivity coating. Finally, the thermal gaps are filled with a low conductance gas such as krypton gas.

Selkowitz, Stephen E. (Piedmont, CA); Arasteh, Dariush K. (Oakland, CA); Hartmann, John L. (Seattle, WA)

1991-01-01T23:59:59.000Z

315

THERMAL NEUTRON BACKSCATTER IMAGING.  

DOE Green Energy (OSTI)

Objects of various shapes, with some appreciable hydrogen content, were exposed to fast neutrons from a pulsed D-T generator, resulting in a partially-moderated spectrum of backscattered neutrons. The thermal component of the backscatter was used to form images of the objects by means of a coded aperture thermal neutron imaging system. Timing signals from the neutron generator were used to gate the detection system so as to record only events consistent with thermal neutrons traveling the distance between the target and the detector. It was shown that this time-of-flight method provided a significant improvement in image contrast compared to counting all events detected by the position-sensitive {sup 3}He proportional chamber used in the imager. The technique may have application in the detection and shape-determination of land mines, particularly non-metallic types.

VANIER,P.; FORMAN,L.; HUNTER,S.; HARRIS,E.; SMITH,G.

2004-10-16T23:59:59.000Z

316

Thermal insulated glazing unit  

DOE Patents (OSTI)

An improved insulated glazing unit is provided which can attain about R5 to about R10 thermal performance at the center of the glass while having dimensions about the same as those of a conventional double glazed insulated glazing unit. An outer glazing and inner glazing are sealed to a spacer to form a gas impermeable space. One or more rigid, non-structural glazings are attached to the inside of the spacer to divide the space between the inner and outer glazings to provide insulating gaps between glazings of from about 0.20 inches to about 0.40 inches. One or more glazing surfaces facing each thermal gap are coated with a low emissivity coating. Finally, the thermal gaps are filled with a low conductance gas such as krypton gas. 2 figs.

Selkowitz, S.E.; Arasteh, D.K.; Hartmann, J.L.

1988-04-05T23:59:59.000Z

317

Thermal imaging diagnostics of high-current electron beams  

SciTech Connect

The thermal imaging diagnostics of measuring pulsed electron beam energy density is presented. It provides control of the electron energy spectrum and a measure of the density distribution of the electron beam cross section, the spatial distribution of electrons with energies in the selected range, and the total energy of the electron beam. The diagnostics is based on the thermal imager registration of the imaging electron beam thermal print in a material with low bulk density and low thermal conductivity. Testing of the thermal imaging diagnostics has been conducted on a pulsed electron accelerator TEU-500. The energy of the electrons was 300-500 keV, the density of the electron current was 0.1-0.4 kA/cm{sup 2}, the duration of the pulse (at half-height) was 60 ns, and the energy in the pulse was up to 100 J. To register the thermal print, a thermal imager Fluke-Ti10 was used. Testing showed that the sensitivity of a typical thermal imager provides the registration of a pulsed electron beam heat pattern within one pulse with energy density over 0.1 J/cm{sup 2} (or with current density over 10 A/cm{sup 2}, pulse duration of 60 ns and electron energy of 400 keV) with the spatial resolution of 0.9-1 mm. In contrast to the method of using radiosensitive (dosimetric) materials, thermal imaging diagnostics does not require either expensive consumables, or plenty of processing time.

Pushkarev, A.; Kholodnaya, G.; Sazonov, R.; Ponomarev, D. [Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

2012-10-15T23:59:59.000Z

318

THERMAL PHASES OF EARTH-LIKE PLANETS: ESTIMATING THERMAL INERTIA FROM ECCENTRICITY, OBLIQUITY, AND DIURNAL FORCING  

SciTech Connect

In order to understand the climate on terrestrial planets orbiting nearby Sun-like stars, one would like to know their thermal inertia. We use a global climate model to simulate the thermal phase variations of Earth analogs and test whether these data could distinguish between planets with different heat storage and heat transport characteristics. In particular, we consider a temperate climate with polar ice caps (like the modern Earth) and a snowball state where the oceans are globally covered in ice. We first quantitatively study the periodic radiative forcing from, and climatic response to, rotation, obliquity, and eccentricity. Orbital eccentricity and seasonal changes in albedo cause variations in the global-mean absorbed flux. The responses of the two climates to these global seasons indicate that the temperate planet has 3 Multiplication-Sign the bulk heat capacity of the snowball planet due to the presence of liquid water oceans. The obliquity seasons in the temperate simulation are weaker than one would expect based on thermal inertia alone; this is due to cross-equatorial oceanic and atmospheric energy transport. Thermal inertia and cross-equatorial heat transport have qualitatively different effects on obliquity seasons, insofar as heat transport tends to reduce seasonal amplitude without inducing a phase lag. For an Earth-like planet, however, this effect is masked by the mixing of signals from low thermal inertia regions (sea ice and land) with that from high thermal inertia regions (oceans), which also produces a damped response with small phase lag. We then simulate thermal light curves as they would appear to a high-contrast imaging mission (TPF-I/Darwin). In order of importance to the present simulations, which use modern-Earth orbital parameters, the three drivers of thermal phase variations are (1) obliquity seasons, (2) diurnal cycle, and (3) global seasons. Obliquity seasons are the dominant source of phase variations for most viewing angles. A pole-on observer would measure peak-to-trough amplitudes of 13% and 47% for the temperate and snowball climates, respectively. Diurnal heating is important for equatorial observers ({approx}5% phase variations), because the obliquity effects cancel to first order from that vantage. Finally, we compare the prospects of optical versus thermal direct imaging missions for constraining the climate on exoplanets and conclude that while zero- and one-dimensional models are best served by thermal measurements, second-order models accounting for seasons and planetary thermal inertia would require both optical and thermal observations.

Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States); Voigt, Aiko [Max Planck Institute for Meteorology, Bundesstr. 53, D-20146 Hamburg (Germany); Abbot, Dorian S., E-mail: n-cowan@nortwestern.edu [Department of Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States)

2012-09-20T23:59:59.000Z

319

Fuzzy Categorization of Weather Conditions for Thermal Mapping  

Science Conference Proceedings (OSTI)

Thermal mapping is a technique that uses a vehicle-mounted infrared radiometer to measure the variation of road surface temperature (RST). Conventionally, the technique is conducted under three qualitatively categorized weather conditions: ...

J. Shao

2000-10-01T23:59:59.000Z

320

Cause of super-thermal electron heating during magnetotail reconnection  

E-Print Network (OSTI)

[1] We present a candidate mechanism for the energization of super-thermal electrons during magnetic reconnection in the Earth's magnetotail. By analyzing in-situ measurements of electron distribution functions we characterize ...

Egedal-Pedersen, Jan

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


321

Raman Spectroscopy of High Thermal Conductivity AlN Ceramics ...  

Science Conference Proceedings (OSTI)

Thermal conductivity of AlN ceramics was measured by laser flash method. Raman spectroscopy was used to characterize oxygen related defects of AlN ... Transport in Co-Based Materials for Fuel Cells and Oxygen Separation Membranes.

322

MoWiTT: The Mobile Window Thermal Test Facility  

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

Airflow schematic MoWiTT: The Mobile Window Thermal Test Facility In the MoWiTT facility, efficient window-and-frame systems are measured to understand the flow of energy through...

323

Aero-Thermal Performance Testing of Silicon Carbide Flexible TPS ...  

Science Conference Proceedings (OSTI)

... and gas-phase measurements including infrared pyrometry, cold-wall heat flux, total pressure, and ... A Review of Metallic Systems Used in Offshore, Sour Environments: The Effect of ... High-temperature Foam-reinforced Thermal Insulation.

324

Thermal Gradient Holes At Coso Geothermal Area (1976) | Open Energy  

Open Energy Info (EERE)

Thermal Gradient Holes At Coso Geothermal Area (1976) Thermal Gradient Holes At Coso Geothermal Area (1976) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Coso Geothermal Area (1976) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date 1976 Usefulness useful DOE-funding Unknown Notes Temperatures have been obtained to depths up to 133 m in 22 boreholes with measurements being made at least four times in each borehole. Geothermal gradients ranged from 240C/km to 450 0C/km. References Combs, J. (1 December 1976) Heat flow determinations and implied thermal regime of the Coso geothermal area, California Retrieved from "http://en.openei.org/w/index.php?title=Thermal_Gradient_Holes_At_Coso_Geothermal_Area_(1976)&oldid=511217"

325

Thermal energy storage material  

DOE Patents (OSTI)

A thermal energy storage material which is stable at atmospheric temperature and pressure and has a melting point higher than 32.degree.F. is prepared by dissolving a specific class of clathrate forming compounds, such as tetra n-propyl or tetra n-butyl ammonium fluoride, in water to form a substantially solid clathrate. The resultant thermal energy storage material is capable of absorbing heat from or releasing heat to a given region as it transforms between solid and liquid states in response to temperature changes in the region above and below its melting point.

Leifer, Leslie (Hancock, MI)

1976-01-01T23:59:59.000Z

326

Thermal test options  

SciTech Connect

Shipping containers for radioactive materials must be qualified to meet a thermal accident environment specified in regulations, such at Title 10, Code of Federal Regulations, Part 71. Aimed primarily at the shipping container design, this report discusses the thermal testing options available for meeting the regulatory requirements, and states the advantages and disadvantages of each approach. The principal options considered are testing with radiant heat, furnaces, and open pool fires. The report also identifies some of the facilities available and current contacts. Finally, the report makes some recommendations on the appropriate use of these different testing methods.

Koski, J.A.; Keltner, N.R.; Sobolik, K.B.

1993-02-01T23:59:59.000Z

327

Thermal ignition combustion system  

DOE Patents (OSTI)

The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

1988-04-19T23:59:59.000Z

328

Thermal Insulation Systems  

E-Print Network (OSTI)

Thermal insulation systems are receiving a high degree of attention in view of increasing energy cost. Industrial, commercial and residential energy users are all well aware of energy cost increases and great emphasis is being directed to energy cost reduction programs. One of the best places to start with energy conservation is to employ proper insulation systems. This article discusses the significant properties of thermal insulation materials primarily for industrial application. Some of the information is applicable to commercial and residential insulation. Only hot service conditions will be covered.

Stanley, T. F.

1982-01-01T23:59:59.000Z

329

Coating thermal noise of a finite-size cylindrical mirror  

E-Print Network (OSTI)

Thermal noise of a mirror is one of the limiting noise sources in the high precision measurement such as gravitational-wave detection, and the modeling of thermal noise has been developed and refined over a decade. In this paper, we present a derivation of coating thermal noise of a finite-size cylindrical mirror based on the fluctuation-dissipation theorem. The result agrees to a previous result with an infinite-size mirror in the limit of large thickness, and also agrees to an independent result based on the mode expansion with a thin-mirror approximation. Our study will play an important role not only to accurately estimate the thermal-noise level of gravitational-wave detectors but also to help analyzing thermal noise in quantum-measurement experiments with lighter mirrors.

Kentaro Somiya; Kazuhiro Yamamoto

2009-03-17T23:59:59.000Z

330

Stochastic Master Equations in Thermal Environment  

E-Print Network (OSTI)

We derive the stochastic master equations which describe the evolution of open quantum systems in contact with a heat bath and undergoing indirect measurements. These equations are obtained as a limit of a quantum repeated measurement model where we consider a small system in contact with an infinite chain at positive temperature. At zero temperature it is well-known that one obtains stochastic differential equations of jump-diffusion type. At strictly positive temperature, we show that only pure diffusion type equations are relevant.

S Attal; C Pellegrini

2010-04-20T23:59:59.000Z

331

Evolution of twisted magnetic fields  

SciTech Connect

The magnetic field of the solar corona evolves quasistatically in response to slowly changing photospheric boundary conditions. The magnetic topology is preserved by the low resistivity of the solar atmosphere. We show that a magnetic flux coordinate system simplifies the problem of calculating field evolution with invariant topology. As an example, we calculate the equilibrium of a thin magnetic flux tube with small twist per unit length.

Zweibel, E.G.; Boozer, A.H.

1985-02-01T23:59:59.000Z

332

Solar thermal financing guidebook  

DOE Green Energy (OSTI)

This guidebook contains information on alternative financing methods that could be used to develop solar thermal systems. The financing arrangements discussed include several lease alternatives, joint venture financing, R and D partnerships, industrial revenue bonds, and ordinary sales. In many situations, alternative financing arrangements can significantly enhance the economic attractiveness of solar thermal investments by providing a means to efficiently allocate elements of risk, return on investment, required capital investment, and tax benefits. A net present value approach is an appropriate method that can be used to investigate the economic attractiveness of alternative financing methods. Although other methods are applicable, the net present value approach has advantages of accounting for the time value of money, yielding a single valued solution to the financial analysis, focusing attention on the opportunity cost of capital, and being a commonly understood concept that is relatively simple to apply. A personal computer model for quickly assessing the present value of investments in solar thermal plants with alternative financing methods is presented in this guidebook. General types of financing arrangements that may be desirable for an individual can be chosen based on an assessment of his goals in investing in solar thermal systems and knowledge of the individual's tax situation. Once general financing arrangements have been selected, a screening analysis can quickly determine if the solar investment is worthy of detailed study.

Williams, T.A.; Cole, R.J.; Brown, D.R.; Dirks, J.A.; Edelhertz, H.; Holmlund, I.; Malhotra, S.; Smith, S.A.; Sommers, P.; Willke, T.L.

1983-05-01T23:59:59.000Z

333

Thermal Reactor Safety  

Science Conference Proceedings (OSTI)

Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

Not Available

1980-06-01T23:59:59.000Z

334

Thermal barrier coating  

SciTech Connect

A thermal barrier coating for hot gas path components of a combustion turbine based on a zirconia-scandia system. A layer of zirconium scandate having the hexagonal Zr.sub.3 Sc.sub.4 O.sub.12 structure is formed directly on a superalloy substrate or on a bond coat formed on the substrate.

Bowker, Jeffrey Charles (Gibsonia, PA); Sabol, Stephen M. (Orlando, FL); Goedjen, John G. (Oviedo, FL)

2001-01-01T23:59:59.000Z

335

Cylindrical thermal contact conductance  

E-Print Network (OSTI)

Thermal contact conductance is highly important in a wide variety of applications, from the cooling of electronic chips to the thermal management of spacecraft. The demand for increased efficiency means that components need to withstand higher temperatures and heat transfer rates. Many situations call for contact heat transfer through nominally cylindrical interfaces, yet relatively few studies of contact conductance through cylindrical interfaces have been undertaken. This study presents a review of the experimental and theoretical investigations of the heat transfer characteristics of composite cylinders, presenting data available in open literature in comparison with relevant correlations. The present investigation presents a study of the thermal contact conductance of cylindrical interfaces. The experimental investigation of sixteen different material combinations offers an opportunity to develop predictive correlations of the contact conductance, in conjunction with an analysis of the interface pressure as a function of the thermal state of the individual cylindrical shells. Experimental results of the present study are compared with previously published conductance data and conductance models.

Ayers, George Harold

2003-08-01T23:59:59.000Z

336

Thermal distribution systems in commercial buildings  

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

Thermal distribution systems in commercial buildings Thermal distribution systems in commercial buildings Title Thermal distribution systems in commercial buildings Publication Type Journal Article LBNL Report Number LBNL-51860 Year of Publication 2003 Authors Diamond, Richard C., Craig P. Wray, Darryl J. Dickerhoff, Nance Matson, and Duo Wang Start Page Chapter Abstract Previous research suggests that HVAC thermal distribution systems in commercial buildings suffer from thermal losses, such as those caused by duct air leakage and poor duct location. Due to a lack of metrics and data showing the potentially large energy savings from reducing these losses, the California building industry has mostly overlooked energy efficiency improvements in this area. The purpose of this project is to obtain the technical knowledge needed to properly measure and understand the energy efficiency of these systems. This project has three specific objectives: to develop metrics and diagnostics for determining system efficiencies, to develop design and retrofit information that the building industry can use to improve these systems, and to determine the energy impacts associated with duct leakage airflows in an existing large commercial building. The primary outcome of this project is the confirmation that duct leakage airflows can significantly impact energy use in large commercial buildings: our measurements indicate that adding 15% duct leakage at operating conditions leads to an increase in fan power of about 25 to 35%. This finding is consistent with impacts of increased duct leakage airflows on fan power that have been predicted by previous simulations. Other project outcomes include the definition of a new metric for distribution system efficiency, the demonstration of a reliable test for determining duct leakage airflows, and the development of new techniques for duct sealing. We expect that the project outcomes will lead to new requirements for commercial thermal distribution system efficiency in future revisions of California's Title 24.

337

Efficient power modeling and software thermal sensing for runtime temperature monitoring  

Science Conference Proceedings (OSTI)

The evolution of microprocessors has been hindered by increasing power consumption and heat dissipation on die. An excessive amount of heat creates reliability problems, reduces the lifetime of a processor, and elevates the cost of cooling and packaging ... Keywords: Power, thermal

Wei Wu; Lingling Jin; Jun Yang; Pu Liu; Sheldon X.-D. Tan

2007-08-01T23:59:59.000Z

338

A Climatological Study of Thermally Driven Wind Systems of the U.S. Intermountain West  

Science Conference Proceedings (OSTI)

This paper investigates the diurnal evolution of thermally driven plain-mountain winds, up- and down-valley winds, up- and downslope winds, and land-lake breezes for summer fair weather conditions in four regions of the Intermountain West where ...

Jebb Q. Stewart; C. David Whiteman; W. James Steenburgh; Xindi Bian

2002-05-01T23:59:59.000Z

339

Thermal radiation from an expanding viscous medium  

E-Print Network (OSTI)

The effects of viscosity on the space time evolution of QGP produced in nuclear collisions at RHIC energies have been studied. The entropy generated due to the viscous motion of the fluid has been taken into account in constraining the initial temperature by the final multiplicity (measured at the freeze-out point). The viscous effects on the photon spectra has been introduced consistently through the evolution dynamics and phase space factors of the particles participating in the production process. We notice a stronger effect on the photon spectra originating from QGP than hadronic matter. A detectable shift is observed in the space-time integrated p_T distribution of photons due to dissipative effects.

Sukanya Mitra; Payal Mohanty; Sourav Sarkar; Jan-e Alam

2011-07-13T23:59:59.000Z

340

THE THERMAL SUNYAEV-ZEL'DOVICH TOMOGRAPHY  

Science Conference Proceedings (OSTI)

The thermal Sunyaev-Zel'dovich (tSZ) effect directly measures the thermal pressure of free electrons integrated along the line of sight and thus contains valuable information on the thermal history of the universe. However, the redshift information is entangled in the projection along the line of sight. This projection effect severely degrades the power of the tSZ effect to reconstruct the thermal history. We investigate the tSZ tomography technique to recover this otherwise lost redshift information by cross-correlating the tSZ effect with galaxies of known redshifts, or alternatively with matter distribution reconstructed from weak-lensing tomography. We investigate in detail the three-dimensional distribution of the gas thermal pressure and its relation with the matter distribution, through our adiabatic hydrodynamic simulation and the one with additional gastrophysics including radiative cooling, star formation, and supernova feedback. (1) We find a strong correlation between the gas pressure and matter distribution, with a typical cross-correlation coefficient r {approx}> 0.7 at k {approx}tight correlation will enable robust cross-correlation measurement between SZ surveys such as Planck, ACT, and SPT and lensing surveys such as DES and LSST, at {approx}>20{sigma}-100{sigma} level. (2) We propose a tomography technique to convert the measured cross-correlation into the contribution from gas in each redshift bin to the tSZ power spectrum. Uncertainties in gastrophysics may affect the reconstruction at {approx}2% level, due to the {approx}1% impact of gastrophysics on r found in our simulations. However, we find that the same gastrophysics affects the tSZ power spectrum at {approx}40% level, so it is robust to infer the gastrophysics from the reconstructed redshift-resolved contribution.

Shao Jiawei; Zhang Pengjie; Lin Weipeng; Jing Yipeng, E-mail: jwshao@shao.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China)

2011-04-01T23:59:59.000Z

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


341

THERMAL INSULATION MATERIALS TEST METHOD ...  

Science Conference Proceedings (OSTI)

... _____ 01/W01 CAN/CGSB-51.2-M88 Thermal Insulation, Calcium Silicate, for Piping, Machinery and Boilers _____ ...

2012-05-22T23:59:59.000Z

342

Liquid metal thermal electric converter  

DOE Patents (OSTI)

A liquid metal thermal electric converter which converts heat energy to electrical energy. The design of the liquid metal thermal electric converter incorporates a unique configuration which directs the metal fluid pressure to the outside of the tube which results in the structural loads in the tube to be compressive. A liquid metal thermal electric converter refluxing boiler with series connection of tubes and a multiple cell liquid metal thermal electric converter are also provided.

Abbin, Joseph P. (Albuquerque, NM); Andraka, Charles E. (Albuquerque, NM); Lukens, Laurance L. (Albuquerque, NM); Moreno, James B. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

343

NVLAP Thermal Insulation Materials LAP  

Science Conference Proceedings (OSTI)

... for thermal insulation materials. The final report for Round 31 was released in February 2010. Proficiency testing is on hold ...

2013-07-18T23:59:59.000Z

344

Directed evolution tools in bioproduct and bioprocess development 49 Chapter 3. Directed Evolution Tools in Bioproduct and  

E-Print Network (OSTI)

Directed evolution tools in bioproduct and bioprocess development 49 Chapter 3. Directed Evolution natural evolution in the laboratory is termed "directed (molecular) evolution" or "in vitro evolution" [3]. Since it was first described in the 1970s, directed evolution has grown in popularity and found a wide

Zhao, Huimin

345

AQUIFER THERMAL ENERGY STORAGE-A SURVEY  

E-Print Network (OSTI)

High temperature underground thermal energy storage, inProceedings, Thermal Energy Storage in Aquifers Workshop:underground thermal energy storage, in ATES newsletter:

Tsang, Chin Fu

2012-01-01T23:59:59.000Z

346

Thermal Transport in Graphene Multilayers and Nanoribbons  

E-Print Network (OSTI)

1 CHAPTER 2 Thermal transport atvalues of graphenes thermal conductivity and different1 Thermal conductivity : metals and non - metallic

Subrina, Samia

2011-01-01T23:59:59.000Z

347

Modeling thermal comfort in stratified environments  

E-Print Network (OSTI)

Arens E. , and Wang D. 2004. "Thermal sensation and comfortin transient non-uniform thermal environments", European7730, 1994, Moderate Thermal Environments Determination of

Zhang, H.; Huizenga, C.; Arens, Edward A; Yu, T.

2005-01-01T23:59:59.000Z

348

Thermal Conduction in Graphene and Graphene Multilayers  

E-Print Network (OSTI)

1 1.2 Thermal transport atxv Introduction xii 1.1 Thermal conductivity and65 4.13 Thermal conductivity of graphene as a function of

Ghosh, Suchismita

2009-01-01T23:59:59.000Z

349

Indoor Thermal Comfort, an Evolutionary Biology Perspective  

E-Print Network (OSTI)

ASHRAE Standard 55-2004: Thermal environmental conditionsA behavioural approach to thermal comfort assessment inBerger, X. , 1998. Human thermal comfort at Nimes in summer

Stoops, John L.

2006-01-01T23:59:59.000Z

350

AQUIFER THERMAL ENERGY STORAGE-A SURVEY  

E-Print Network (OSTI)

1978, High temperature underground thermal energy storage,in Proceedings, Thermal Energy Storage in Aquifers Workshop:High temperature underground thermal energy storage, in ATES

Tsang, Chin Fu

2012-01-01T23:59:59.000Z

351

THERMAL ENERGY STORAGE IN AQUIFERS WORKSHOP  

E-Print Network (OSTI)

B. Quale. Seasonal storage of thermal energy in water in theand J. Schwarz, Survey of Thermal Energy Storage in AquifersSecond Annual Thermal Energy Storage Contractors'

Authors, Various

2011-01-01T23:59:59.000Z

352

Holographic Thermal Helicity  

E-Print Network (OSTI)

We study the thermal helicity, defined in arXiv:1211.3850, of a conformal field theory with anomalies in the context of AdS$_{2n+1}$/CFT$_{2n}$. To do so, we consider large charged rotating AdS black holes in the Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant using fluid/gravity expansion. We compute the anomaly-induced current and stress tensor of the dual CFT in leading order of the fluid/gravity derivative expansion and show their agreement with the field theoretical replacement rule for the thermal helicity. Such replacement rule is reflected in the bulk by new replacement rules obeyed by the Hall currents around the black hole.

Tatsuo Azeyanagi; R. Loganayagam; Gim Seng Ng; Maria J. Rodriguez

2013-11-12T23:59:59.000Z

353

Reactor Thermal-Hydraulics  

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

Thermal-Hydraulics Thermal-Hydraulics Dr. Tanju Sofu, Argonne National Laboratory In a power reactor, the energy produced in fission reaction manifests itself as heat to be removed by a coolant and utilized in a thermodynamic energy conversion cycle to produce electricity. A simplified schematic of a typical nuclear power plant is shown in the diagram below. Primary coolant loop Steam Reactor Heat exchanger Primary pump Secondary pump Condenser Turbine Water Although this process is essentially the same as in any other steam plant configuration, the power density in a nuclear reactor core is typically four orders of magnitude higher than a fossil fueled plant and therefore it poses significant heat transfer challenges. Maximum power that can be obtained from a nuclear reactor is often limited by the

354

Thermally stable diamond brazing  

DOE Patents (OSTI)

A cutting element and a method for forming a cutting element is described and shown. The cutting element includes a substrate, a TSP diamond layer, a metal interlayer between the substrate and the diamond layer, and a braze joint securing the diamond layer to the substrate. The thickness of the metal interlayer is determined according to a formula. The formula takes into account the thickness and modulus of elasticity of the metal interlayer and the thickness of the TSP diamond. This prevents the use of a too thin or too thick metal interlayer. A metal interlayer that is too thin is not capable of absorbing enough energy to prevent the TSP diamond from fracturing. A metal interlayer that is too thick may allow the TSP diamond to fracture by reason of bending stress. A coating may be provided between the TSP diamond layer and the metal interlayer. This coating serves as a thermal barrier and to control residual thermal stress.

Radtke, Robert P. (Kingwood, TX)

2009-02-10T23:59:59.000Z

355

Thermal spallation drilling  

DOE Green Energy (OSTI)

Thermal spallation drilling is an underdeveloped process with great potential for reducing the costs of drilling holes and mining shafts and tunnels in most very hard rocks. Industry has used this process to drill blast holes for emplacing explosives and to quarry granite. Some theoretical work has been performed, and many signs point to a great future for this process. The Los Alamos National Laboratory has studied the theory of the spallation process and is conducting experiments to prove out the system and to adapt it for use with a conventional rotary rig. This report describes work that has been accomplished at the Laboratory on the development of thermal spallation drilling and some work that is projected for the future on the system. 3 references, 3 figures.

Williams, R.E.

1985-01-01T23:59:59.000Z

356

Solar thermal power  

DOE Green Energy (OSTI)

Solar thermal power is produced by three types of concentrating systems, which utilize parabolic troughs, dishes, and heliostats as the solar concentrators. These systems are at various levels of development and commercialization in the United States and in Europe. The U.S. Industry is currently developing these systems for export at the end of this century and at the beginning of the next one for remote power, village electrification, and grid-connected power. U.S. utilities are not forecasting to need power generation capacity until the middle of the first decade of the 21{sup st} century. At that time, solar thermal electric power systems should be cost competitive with conventional power generation in some unique U.S. markets. In this paper, the authors describe the current status of the development of trough electric, dish/engine, and power tower solar generation systems. 46 refs., 20 figs., 8 tabs.

Mancini, T.R.; Kolb, G.J.; Prairie, M.R. [Sandia National Labs., Albuquerque, NM (United States)

1997-12-31T23:59:59.000Z

357

Thermal Stabilization Blend Plan  

SciTech Connect

This Blend Plan documents the feed material items that are stored in 2736-2 vaults, the 2736-ZB 638 cage, the 192C vault, and the 225 vault that will be processed through the thermal stabilization furnaces. The purpose of thermal stabilization is to heat the material to 1000 degrees Celsius to drive off all water and leave the plutonium and/or uranium as oxides. The stabilized material will be sampled to determine the Loss On Ignition (LOI) or percent water. The stabilized material must meet water content or LOI of less than 0.5% to be acceptable for storage under DOE-STD-3013-99 specifications. Out of specification material will be recycled through the furnaces until the water or LOI limits are met.

RISENMAY, H.R.

2000-05-02T23:59:59.000Z

358

Report on THMC Modeling of the Near Field Evolution of a Generic Clay  

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

on THMC Modeling of the Near Field Evolution of a Generic on THMC Modeling of the Near Field Evolution of a Generic Clay Repository: Model Validation and Demonstration Rev 2 Report on THMC Modeling of the Near Field Evolution of a Generic Clay Repository: Model Validation and Demonstration Rev 2 Shale and clay-rich rock formations have been considered as potential host rocks for geological disposal of high-level radioactive waste throughout the world. Coupled thermal, hydrological, mechanical, and chemical (THMC) processes have a significant impact on the long-term safety of a repository in this type of rocks. The validity of the two-part Hooke's model (TPHM), a new constitutive relationship, and associated formulations regarding rock hydraulic/mechanical properties is demonstrated by the consistency between observations from a mine-by test at the Mont Terri site

359

Evolution of blind cave fish  

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

Evolution of blind cave fish Evolution of blind cave fish Name: rudeeric Location: N/A Country: N/A Date: N/A Question: I am a biology teacher, now starting a unit on evolution. Just about every book on the topic mentions the blind and albino cave fish. But I've always been bothered by this example. Why is being blind and white an advantage for animals in a cave? I understand that they have no use for eyes or pigment, but this sounds like we're back to Lamarck's law of use and disuse. Wouldn't there first have to be the mutations to cause these? And in order for the changes to become common, they would have to be advantageous. Although there is no use for the eyes or pigment, what is the advantage to losing them? Replies: I can think of one important use for the loss of pigment in fish. It has been documented with the early breeding of black mollies and black angelfish, that the fry were extremely hard to keep alive. The breeders found that these fish required much greatly quantities of protein to produce the pigment melanin, and therefore supplementing the fry with protein quantities that were many times higher than those required by less pigmented fish kept them alive. Imagine then, a situation where a random mutation of albinism in a cave dwelling fish results in a population that can use the protein that it consumes for growth and reproduction, rather than for pigment production. The albino fish could quickly out-produce the pigmented fish. What the "real" explanation would be as described by an evolutionary biologist, I have no idea.

360

Concentrating Solar Thermal Technology  

Science Conference Proceedings (OSTI)

After nearly 20 years of commercial dormancy, concentrating solar thermal (CST) power development and investment activity is heating up globally. Encouraged by volatile energy prices, carbon markets, and renewable-friendly policies, an increasing number of established companies, newcomers, utilities, and government agencies are planning to deploy CST systems to tap the technologies' improving conversion efficiencies and low-cost electricity production potential. This renewable energy technology perspecti...

2009-03-27T23:59:59.000Z

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


361

THERMAL NEUTRONIC REACTOR  

DOE Patents (OSTI)

A novel thermal reactor was designed in which a first reflector formed from a high atomic weight, nonmoderating material is disposed immediately adjacent to the reactor core. A second reflector composed of a moderating material is disposed outwardly of the first reflector. The advantage of this novel reflector arrangement is that the first reflector provides a high slow neutron flux in the second reflector, where irradiation experiments may be conducted with a small effect on reactor reactivity.

Spinrad, B.I.

1960-01-12T23:59:59.000Z

362

Thermal reactor safety  

SciTech Connect

Information is presented concerning new trends in licensing; seismic considerations and system structural behavior; TMI-2 risk assessment and thermal hydraulics; statistical assessment of potential accidents and verification of computational methods; issues with respect to improved safety; human factors in nuclear power plant operation; diagnostics and activities in support of recovery; LOCA transient analysis; unresolved safety issues and other safety considerations; and fission product transport.

1980-06-01T23:59:59.000Z

363

Thermally actuated thermionic switch  

DOE Patents (OSTI)

A thermally actuated thermionic switch which responds to an increase of temperature by changing from a high impedance to a low impedance at a predictable temperature set point. The switch has a bistable operation mode switching only on temperature increases. The thermionic material may be a metal which is liquid at the desired operation temperature and held in matrix in a graphite block reservoir, and which changes state (ionizes, for example) so as to be electrically conductive at a desired temperature.

Barrus, D.M.; Shires, C.D.

1982-09-30T23:59:59.000Z

364

Structural Evolution of Carbon During Oxidation  

SciTech Connect

The examination of the structural evolution of carbon during oxidation has proven to be of scientific interest. Early modeling work of fluidized bed combustion showed that most of the reactions of interest occurs iOn the micropores, and this work has concentrated on these pores. This work has concentrated on evolution of macroporosity and rnicroporosity of carbons during kinetic controlled oxidation using SAXS, C02 and TEM analysis. Simple studies of fluidized bed combustion of coal chars has shown that many of the events considered fragmentation events previously may in fact be "hidden" or nonaccessible porosity. This makes the study of the microporous combustion characteristics of carbon even more important. The generation of a combustion resistant grid, coupled with measurements of the SAXS and C02 surface areas, fractal analysis and TEM studies has confined that soot particles shrink during their oxidation, as previously suspected. However, this shrinkage results in an overall change in structure. This structure becomes, on a radial basis, much more ordered near the edges, while the center itself becomes transparent to the TEM beam, implying a total lack of structure in this region. Although complex, this carbon structure is probably burning as to keep the density of the soot particles nearly the same. The TEM techniques developed for examination of soots has also been applied to Spherocarb. The Spherocarb during oxidation also increases its ordering,. This ordering, by present theories, would imply that the reactivity would go. However, the reactivity goes up, implying that structure of carbon is secondary in importance to catalytic effects.

Adel F. Sarofim; Angelo Kandas

1998-10-28T23:59:59.000Z

365

Mobile Window Thermal Test  

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

Mobile Window Thermal Test (MoWiTT) Facility Mobile Window Thermal Test (MoWiTT) Facility winter.jpg (469135 bytes) The window has come a long way since the days when it was a single pane of glass in a wood frame. Low-emissivity windows were designed to help buildings retain some of the energy that would have leaked out of less efficient windows. Designing efficient window-and-frame systems is one strategy for reducing the energy use of buildings. But the net energy flowing through a window is a combination of temperature- driven thermal flows and transmission of incident solar energy, both of which vary with time. U-factor and solar heat gain coefficient (SHGC), the window properties that control these flows, depend partly on ambient conditions. Window energy flows can affect how much energy a building uses, depending on when the window flows are available to help meet other energy demands within the building, and when they are adverse, adding to building energy use. This leads to a second strategy for reducing building energy use: using the beneficial solar gain available through a window, either for winter heating or for daylighting, while minimizing adverse flows.

366

Enhancing Thermal Conductivity and Reducing Friction  

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

Laboratory currently has several projects underway to develop advanced fluids, films, coatings, and Laboratory currently has several projects underway to develop advanced fluids, films, coatings, and processes to improve thermal conductivity and reduce friction. These measures are helping to increase energy efficiency for next-generation transportation applications. Superhard and Slick Coating (SSC) Opportunity: Friction, wear, and lubrication strongly affect the energy efficiency, durability, and environmental compatibility of

367

Pyrolysis of epoxies used for thermal-battery headers  

DOE Green Energy (OSTI)

Thermally activated batteries use an epoxy for encapsulation of the electrical feedthroughs in the header of the battery. When the thermal battery is thermally abused, the encapsulant can pyrolyze and generate large internal pressures. This causes the battery to vent in extreme cases. The nature of these gases has never been adequately documented. Therefore, a study was undertaken to address this deficiency. The pyrolysis of various encapsulants that have been used, or are being considered for use, in thermally activated batteries was studied over a temperature range of 155 to 455 C. The composition of the pyrolysis decomposition products was determined by gas chromatography/mass spectrometry (GS/MS). This determination is helpful in assessing the potential environmental and health effect for personnel exposed to such gases. In addition, the thermal stability of the various epoxies was measured by thermogravimetric analysis (TGA).

Guidotti, R.A.; Thornberg, S.M.; Campbell-Domme, B.

1995-08-01T23:59:59.000Z

368

CALIFORNIA SOLAR INITIATIVE-THERMAL PROGRAMHANDBOOK  

E-Print Network (OSTI)

CALIFORNIA SOLAR INITIATIVE-THERMAL PROGRAMHANDBOOK CALIFORNIA PUBLIC UTILITIES California Solar Initiative Thermal Program Handbook i 1. Introduction to CSI-Thermal Program...........................................................................................................................11 #12;Table of Contents California Solar Initiative Thermal Program Handbook ii 2.5 Surface

369

Dynamic Evolution for Risk-Neutral Densities  

E-Print Network (OSTI)

We solved the scaled formulation for problems (7) and (10) and obtained the dynamic evolution for the densities (see Figure 1). For this data set, we.

370

Relationship between Microstructural Evolution, Order-disorder ...  

Science Conference Proceedings (OSTI)

However, the scientific literature about microstructure and texture evolution in beta brass is scarce. This paper deals with the compression tests performed on the...

371

Comparative economics: evolution and the modern economy  

E-Print Network (OSTI)

A comparison of primate economies. Journal of Bioeconomics,1999). Complexity and the economy. Science, 284, 107109.evolution and the modern economy Ghabrial, A. S. , &

Vermeij, Geerat J.

2009-01-01T23:59:59.000Z

372

Computational Modeling of Defect Evolution under Irradiation  

Science Conference Proceedings (OSTI)

Mar 14, 2012 ... Radiation Effects in Ceramic Oxide and Novel LWR Fuels: Computational Modeling of Defect Evolution under Irradiation Sponsored by: The...

373

Numerical Modeling and Optimization of Microstructure Evolution ...  

Science Conference Proceedings (OSTI)

Presentation Title, Numerical Modeling and Optimization of Microstructure Evolution ... A Hybrid Model on Low Energy Ion Beam Processing Leading to Phase...

374

EVOLUTION AND ADVANCED CHARACTERIZATION OF THIN ...  

Science Conference Proceedings (OSTI)

EVOLUTION OF THIN FILM MICROSTRUCTURE AND MORPHOLOGY DURING CHEMICAL VAPOR DEPOSITION: D.P.Adams, T.M. Mayer, E. Chason, B.S....

375

Hydrogen Evolution Behaviour during Tensile Deformation in ...  

Science Conference Proceedings (OSTI)

Hydrogen evolution behaviour during tensile deformation and fracture was also investigated by using a testing machine equipped with a quadrupole mass...

376

Thermal and non-thermal energies in solar flares  

E-Print Network (OSTI)

The energy of the thermal flare plasma and the kinetic energy of the non-thermal electrons in 14 hard X-ray peaks from 9 medium-sized solar flares have been determined from RHESSI observations. The emissions have been carefully separated in the spectrum. The turnover or cutoff in the low-energy distribution of electrons has been studied by simulation and fitting, yielding a reliable lower limit to the non-thermal energy. It remains the largest contribution to the error budget. Other effects, such as albedo, non-uniform target ionization, hot target, and cross-sections on the spectrum have been studied. The errors of the thermal energy are about equally as large. They are due to the estimate of the flare volume, the assumption of the filling factor, and energy losses. Within a flare, the non-thermal/thermal ratio increases with accumulation time, as expected from loss of thermal energy due to radiative cooling or heat conduction. Our analysis suggests that the thermal and non-thermal energies are of the same magnitude. This surprising result may be interpreted by an efficient conversion of non-thermal energy to hot flare plasma.

Pascal Saint-Hilaire; Arnold O. Benz

2005-03-03T23:59:59.000Z

377

Field Studies of Subjective Effects on Thermal Comfort in a University Classroom  

E-Print Network (OSTI)

Two field studies were conducted in a university classroom in the autumn of 2004 in Harbin. The objective of these studies was to assess the thermal conditions and the subjective effects on occupant thermal comfort. A field study was carried out when the undergraduate students were not taught the theory of thermal comfort. A second study was conducted after the undergraduate students knew something about thermal comfort. The thermal comfort variables were measured when the students were filling in the subjective questionnaires on thermal sensation and thermal comfort. A total of 167 sets of questionnaire responses were obtained. The indoor thermal environmental data for the two days are almost the same; however the thermal acceptability is different. The acceptability of the first study is 96.0%, which is higher than the acceptability of 91.5% according to the PPD. In contrast, the acceptability of the second study is 57.4%, which is very low compared with the acceptability of 95.0% according to the PPD. The students' thermal acceptability of the thermal environment before learning the theory of thermal comfort is higher than after learning about thermal comfort. These results confirm the existence of subjective effects on thermal comfort.

Wang, J.; Wang, Z.

2006-01-01T23:59:59.000Z

378

CONSISTENT SELF-SIMILAR MAGNETOHYDRODYNAMICS EVOLUTION OF CORONAL TRANSIENTS  

Science Conference Proceedings (OSTI)

The self-similar model of coronal transients by B. C. Low is reconsidered. Due to a modification of the basic set of the initial assumptions of the model, a new class of more consistent solutions is found. The main advantage of these new solutions is that they do not contain areas with a physically inconsistent negative pressure. Instead, the novel solutions are derived on the basis of a special prescription for the thermal pressure of the transients that guarantees, by design, its positiveness throughout the whole evolution domain. The possible importance of these solutions for understanding the physics of the transient interplanetary coronal mass ejections (ICMEs; originating from the Sun), and magnetic clouds as a subclass of these, is discussed. A practical example is cited illustrating the application of our analytic results to describe some properties of real ICMEs. Some directions and scopes for further research are outlined.

Shapakidze, David; Rogava, Andria [E. Kharadze Georgian National Astrophysical Observatory, Ilia Chavchavadze State University, Tbilisi (Georgia); Debosscher, Arnold; Poedts, Stefaan [Centre for Plasma Astrophysics, Katholieke Universiteit Leuven, Leuven (Belgium)

2010-03-20T23:59:59.000Z

379

Principles of software evolution: 5th international workshop on principles of software evolution (IWPSE 2002)  

Science Conference Proceedings (OSTI)

We present an overview of the 5th International Workshop on Principles of Software Evolution (IWPSE 2002).

Mikio Aoyama; Katsuro Inoue; Vclav Rajlich

2002-05-01T23:59:59.000Z

380

Manipulation of Thermal Phonons  

E-Print Network (OSTI)

Developing materials that can conduct electricity easily, but block the motion of phonons is necessary in the applications of thermoelectric devices, which can generate electricity from temperature differences. In converse, a key requirement as chips get faster is to obtain better ways to dissipate heat. Controlling heat transfer in these crystalline materials devices such as silicon is important. The heat is actually the motion or vibration of atoms known as phonons. Finding ways to manipulate the behavior of phonons is crucial for both energy applications and the cooling of integrated circuits. A novel class of artificially periodic structured materials phononic crystals might make manipulation of thermal phonons possible. In many fields of physical sciences and engineering, acoustic wave propagation in solids attracts many researchers. Wave propagation phenomena can be analyzed by mathematically solving the acoustic wave equation. However, wave propagation in inhomogeneous media with various geometric structures is too complex to find an exact solution. Hence, the Finite Difference Time Domain method is developed to investigate these complicated problems. In this work, the Finite-Difference Time-Domain formula is derived from acoustic wave equations based on the Taylors expansion. The numerical dispersion and stability problems are analyzed. In addition, the convergence conditions of numerical acoustic wave are stated. Based on the periodicity of phononic crystal, the Blochs theorem is applied to fulfill the periodic boundary condition of the FDTD method. Then a wide-band input signal is used to excite various acoustic waves with different frequencies. In the beginning of the calculation process, the wave vector is chosen and fixed. By means of recording the displacement field and taking the Fourier transformation, we can obtain the eigenmodes from the resonance peaks of the spectrum and draw the dispersion relation curve of acoustic waves. With the large investment in silicon nanofabrication techniques, this makes tungsten/silicon phononic crystal a particularly attractive platform for manipulating thermal phonons. Phononic crystal makes use of the fundamental properties of waves to create band gap over which there can be no propagation of acoustic waves in the crystal. This crystal can be applied to deterministically manipulate the phonon dispersion curve affected by different crystal structures and to modify the phonon thermal conductivity accordingly. We can expect this unique metamaterial is a promising route to creating unprecedented thermal properties for highly-efficient energy harvesting and thermoelectric cooling.

Hsu, Chung-Hao

2013-05-01T23:59:59.000Z

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


381

Thermal Stabilization Blend Plan  

SciTech Connect

The Blend Plan was written to identify items stored outside of the 213 MBA that will be moved into the MBA for thermal stabilization processing. Product quality oxide items stored in our vaults are found in Appendix A. A table is included in Appendix A which details the isotopic values for the oxide items and calculates the amount of material of any specific run that can be placed in a product can and maintain the 15 watt limit to meet storage vault specifications. This Revision of the Blend Plan adds items of lesser dose rate to lower the exposure of the workers until additional shielding can be added to the gloveboxes.

RISENMAY, H.R.

2000-04-20T23:59:59.000Z

382

Advanced solar thermal technology  

SciTech Connect

The application of dish solar collectors to industrial process heat (IPH) has been reviewed. IPH represents a market for displacement of fossil fuels (10 quads/y). A 10% market penetration would indicate a substantial market for solar thermal systems. Apparently, parabolic dish systems can produce IPH at a lower cost than that of troughs or compound parabolic concentrators, even though dish fabrication costs per unit area are more expensive. Successful tests of point-focusing collectors indicate that these systems can meet the energy requirements for process heat applications. Continued efforts in concentrator and transport technology development are needed. 7 figures.

Leibowitz, L.P.; Hanseth, E.; Liu, T.M.

1982-06-01T23:59:59.000Z

383

Storage and retrieval of thermal light in warm atomic vapor  

SciTech Connect

We report slowed propagation and storage and retrieval of thermal light in warm rubidium vapor using the effect of electromagnetically induced transparency (EIT). We first demonstrate slowed propagation of the probe thermal light beam through an EIT medium by measuring the second-order correlation function of the light field using the Hanbury-Brown-Twiss interferometer. We also report an experimental study on the effect of the EIT slow-light medium on the temporal coherence of thermal light. Finally, we demonstrate the storage and retrieval of the thermal light beam in the EIT medium. The direct measurement of the photon number statistics of the retrieved light field shows that the photon number statistics are preserved during the storage and retrieval processes.

Cho, Young-Wook; Kim, Yoon-Ho [Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)

2010-09-15T23:59:59.000Z

384

Structural stability vs. thermal performance: old dilemma, new solutions  

SciTech Connect

In many building envelopes, actual thermal performance falls quite a bit short of nominal design parameters given in standards. Very often only windows, doors, and a small part of the wall area meet standards requirements. In the other parts of the building envelope, unaccounted thermal bridges reduce the effective thermal resistance of the insulation material. Such unaccounted heat losses compromise the thermal performance of the whole building envelope. For the proper analysis of the thermal performance of most wall and roof details, measurements and three-dimensional thermal modeling are necessary. For wall thermal analysis the whole-wall R-value calculation method can be very useful. In ties method thermal properties of all wall details are incorporated as an area weighted average. For most wall systems, the part of the wall that is traditionally analyzed, is the clear wall, that is, the flat part of the wall that is uninterrupted by details. It comprises only 50 to 80% of the total area of the opaque wall. The remaining 20 to 50% of the wall area is not analyzed nor are its effects incorporated in the thermal performance calculations. For most of the wall technologies, traditionally estimated R-values are 20 to 30% higher than whole-wall R-values. Such considerable overestimation of wall thermal resistance leads to significant errors in building heating and cooling load estimations. In this paper several examples are presented of the use of the whole-wall R-value procedure for building envelope components. The advantages of the use of the whole wall R-value calculation procedure are also discussed. For several building envelope components, traditional clear-wall R-values are compared with the results of whole-wall thermal analysis to highlight significant limits on the use of the traditional methods and the advantages of advanced computer modeling.

Kosny, J.; Christian, J.E.

1996-10-01T23:59:59.000Z

385

THERMAL PROPERTIES OF FIBERBOARD OVERPACK MATERIALS IN THE 9975 SHIPPING PACKAGE  

DOE Green Energy (OSTI)

The 9975 shipping package incorporates a cane fiberboard overpack for thermal insulation and impact resistance. Thermal properties (thermal conductivity and specific heat capacity) have been measured on cane fiberboard and a similar wood fiber-based product at several temperatures representing potential storage conditions. While the two products exhibit similar behavior, the measured specific heat capacity varies significantly from prior data. The current data are being developed as the basis to verify that this material remains acceptable over the extended storage time period.

VORMELKER, PHILLIP; DAUGHERTY, W. L.

2005-06-10T23:59:59.000Z

386

Magnetohydrodynamic evolution of magnetic skeletons  

E-Print Network (OSTI)

The heating of the solar corona is likely to be due to reconnection of the highly complex magnetic field that threads throughout its volume. We have run a numerical experiment of an elementary interaction between the magnetic field of two photospheric sources in an overlying field that represents a fundamental building block of the coronal heating process. The key to explaining where, how and how much energy is released during such an interaction is to calculate the resulting evolution of the magnetic skeleton. A skeleton is essentially the web of magnetic flux surfaces (called separatrix surfaces) that separate the coronal volume into topologically distinct parts. For the first time the skeleton of the magnetic field in a 3D numerical MHD experiment is calculated and carefully analysed, as are the ways in which it bifurcates into different topologies. A change in topology normally changes the number of magnetic reconnection sites. In our experiment, the magnetic field evolves through a total of six distinct ...

Haynes, A L; Galsgaard, K; Priest, E R; Haynes, Andrew L.; Parnell, Clare E.; Galsgaard, Klaus; Priest, Eric R.

2007-01-01T23:59:59.000Z

387

Hard thermal effective action in QCD through the thermal operator  

E-Print Network (OSTI)

Through the application of the thermal operator to the zero temperature retarded Green's functions, we derive in a simple way the well known hard thermal effective action in QCD. By relating these functions to forward scattering amplitudes for on-shell particles, this derivation also clarifies the origin of important properties of the hard thermal effective action, such as the manifest Lorentz and gauge invariance of its integrand.

Ashok Das; J. Frenkel

2007-03-08T23:59:59.000Z

388

2 Technology Description: Solar Thermal Parabolic Trough Solar Thermal  

E-Print Network (OSTI)

Parabolic troughs track sun, concentrate incident light onto a centralized, tubular receiver that runs length of each trough Thermal fluid circulates through all receivers in solar field Thermal fluid brought to one or more centralized power production facilities Heat transferred to a steam cycle, drives a steam turbine to generate power Cooled thermal fluid is then recirculated th through h solar fi field ld Wet cooling is common, dry cooling possible

Timothy J. Skone; Risks Of Implementation

2012-01-01T23:59:59.000Z

389

An overview: Component development for solar thermal systems  

DOE Green Energy (OSTI)

In this paper, I review the significant issues and the development of solar concentrators and thermal receivers for central-receiver power plants and dish/engine systems. Due to the breadth of the topic area, I have arbitrarily narrowed the content of this paper by choosing not to discuss line-focus (trough) systems and energy storage. I will focus my discussion on the development of heliostats, dishes, and receivers since the 1970s with an emphasis on describing the technologies and their evolution, identifying some key observations and lessons learned, and suggesting what the future in component development may be.

Mancini, T.R.

1994-10-01T23:59:59.000Z

390

Transformer Thermal Modeling: Improving Reliability Using Data Quality Control  

E-Print Network (OSTI)

1 Transformer Thermal Modeling: Improving Reliability Using Data Quality Control Daniel J. Tylavsky--Eventually all large transformers will be dynamically loaded using models updated regularly from field measured data. Models obtained from measured data give more accurate results than models based on transformer

391

Method to determine thermal profiles of nanoscale circuitry  

DOE Patents (OSTI)

A platform that can measure the thermal profiles of devices with nanoscale resolution has been developed. The system measures the local temperature by using an array of nanoscale thermometers. This process can be observed in real time using a high resolution imagining technique such as electron microscopy. The platform can operate at extremely high temperatures.

Zettl, Alexander K; Begtrup, Gavi E

2013-04-30T23:59:59.000Z

392

Ratings of Transmission Lines: Applications, Computations, and Thermal Models  

Science Conference Proceedings (OSTI)

The thermal rating of overhead transmission lines can be complex, because there is no way to directly measure the line rating and because high current load events occur only rarely in most parts of the power system. A thermal line rating is a prediction of how the conductor will behave thermally, mechanically, and electrically in the event of a high electrical current. It is possible to calculate ratings incorrectly and not discover that this is true until a most inopportune timeduring a system emergency...

2011-12-16T23:59:59.000Z

393

Atmospheric Environment 39 (2005) 34313443 Chemical evolution of an isolated power plant plume during  

E-Print Network (OSTI)

; Texas 2000 Air Quality Study; Aerosol growth; Airborne measurements 1. Introduction Power plantsAtmospheric Environment 39 (2005) 3431­3443 Chemical evolution of an isolated power plant plume from a coal-burning power plant were measured during a research flight of the DOE G-1 during the Texas

394

Stress evolution during Ni-Si compound formation for fully silicided (FUSI) gates  

Science Conference Proceedings (OSTI)

The stress (force) evolution during the formation of different Ni silicide phases was monitored by in situ curvature measurements, for the reaction of thin Ni films of various thicknesses with 100nm polycrystalline-Si deposited on oxidized (100) Si substrates. ... Keywords: In situ XRD, In situ curvature measurements, Ni-silicides

C. Torregiani; C. Van Bockstael; C. Detavernier; C. Lavoie; A. Lauwers; K. Maex; J. A. Kittl

2007-11-01T23:59:59.000Z

395

Thermal and Structural Equilibrium Studies of Organic Thermal ...  

Science Conference Proceedings (OSTI)

These organic materials undergo a solid-solid state phase transition before melting which will store large amounts of thermal energy. The binary system of...

396

Electric Vehicle Battery Thermal Issues and Thermal Management Techniques (Presentation)  

SciTech Connect

This presentation examines the issues concerning thermal management in electric drive vehicles and management techniques for improving the life of a Li-ion battery in an EDV.

Rugh, J. P.; Pesaran, A.; Smith, K.

2013-07-01T23:59:59.000Z

397

Quantifying nonclassicality: global impact of local unitary evolutions  

E-Print Network (OSTI)

We show that only those composite quantum systems possessing nonvanishing quantum correlations have the property that any nontrivial local unitary evolution changes their global state. We derive the exact relation between the global state change induced by local unitary evolutions and the amount of quantum correlations. We prove that the minimal change coincides with the geometric measure of discord (defined via the Hilbert- Schmidt norm), thus providing the latter with an operational interpretation in terms of the capability of a local unitary dynamics to modify a global state. We establish that two-qubit Werner states are maximally quantum correlated, and are thus the ones that maximize this type of global quantum effect. Finally, we show that similar results hold when replacing the Hilbert-Schmidt norm with the trace norm.

S. M. Giampaolo; A. Streltsov; W. Roga; D. Bru; F. Illuminati

2012-06-18T23:59:59.000Z

398

Aiding evolution with concern-oriented guides  

Science Conference Proceedings (OSTI)

Program documentation is often incomplete and out of date due to its tediousness and perceived low value. This requires evolution tasks to be preceded by time-consuming exploration. In this paper, we explore a concern-oriented approach to documentation ... Keywords: aspect-oriented software development, concern modeling, documentation, separation of concerns, software evolution, user guidance

Barthlmy Dagenais; Harold Ossher

2007-03-01T23:59:59.000Z

399

PERSPECTIVE Directed Evolution of Novel Protein Functions  

E-Print Network (OSTI)

PERSPECTIVE Directed Evolution of Novel Protein Functions Huimin Zhao1,2 1 Department of Chemical.interscience.wiley.com). DOI 10.1002/bit.21455 ABSTRACT: Directed evolution has been successfully used to engineer proteins for basic and applied biological research. However, engineering of novel protein functions by directed

Zhao, Huimin

400

The Evolution of Rotor and Blade Design  

DOE Green Energy (OSTI)

The objective of this paper is to provide a historical perspective of the evolution of rotor and blade design during the last 20 years. This evolution is a balanced integration of economic, aerodynamic, structural dynamic, noise, and aesthetic considerations, which are known to be machine type and size dependent.

Tangler, J.

2000-08-01T23:59:59.000Z

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


401

Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models  

E-Print Network (OSTI)

1 Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models distilled from measure data, rather than models derived from transformer heat for measuring the acceptability of transformer thermal models. For a model to be acceptable, it must have

402

Method for determining thermal conductivity and thermal capacity per unit volume of earth in situ  

DOE Patents (OSTI)

A method for determining the thermal conductivity of the earth in situ is based upon a cylindrical probe (10) having a thermopile (16) for measuring the temperature gradient between sets of thermocouple junctions (18 and 20) of the probe after it has been positioned in a borehole and has reached thermal equilibrium with its surroundings, and having means (14) for heating one set of thermocouple junctions (20) of the probe at a constant rate while the temperature gradient of the probe is recorded as a rise in temperature over several hours (more than about 3 hours). A fluid annulus thermally couples the probe to the surrounding earth. The recorded temperature curves are related to the earth's thermal conductivity, k.sub..infin., and to the thermal capacity per unit volume, (.gamma.c.sub.p).sub..infin., by comparison with calculated curves using estimates of k.sub..infin. and (.gamma.c.sub.p).sub..infin. in an equation which relates these parameters to a rise in the earth's temperature for a known and constant heating rate.

Poppendiek, Heinz F. (LaJolla, CA)

1982-01-01T23:59:59.000Z

403

Thermal-Hydrological Sensitivity Analysis of Underground Coal Gasification  

DOE Green Energy (OSTI)

This paper presents recent work from an ongoing project at Lawrence Livermore National Laboratory (LLNL) to develop a set of predictive tools for cavity/combustion-zone growth and to gain quantitative understanding of the processes and conditions (natural and engineered) affecting underground coal gasification (UCG). We discuss the application of coupled thermal-hydrologic simulation capabilities required for predicting UCG cavity growth, as well as for predicting potential environmental consequences of UCG operations. Simulation of UCG cavity evolution involves coupled thermal-hydrological-chemical-mechanical (THCM) processes in the host coal and adjoining rockmass (cap and bedrock). To represent these processes, the NUFT (Nonisothermal Unsaturated-saturated Flow and Transport) code is being customized to address the influence of coal combustion on the heating of the host coal and adjoining rock mass, and the resulting thermal-hydrological response in the host coal/rock. As described in a companion paper (Morris et al. 2009), the ability to model the influence of mechanical processes (spallation and cavity collapse) on UCG cavity evolution is being developed at LLNL with the use of the LDEC (Livermore Distinct Element Code) code. A methodology is also being developed (Morris et al. 2009) to interface the results of the NUFT and LDEC codes to simulate the interaction of mechanical and thermal-hydrological behavior in the host coal/rock, which influences UCG cavity growth. Conditions in the UCG cavity and combustion zone are strongly influenced by water influx, which is controlled by permeability of the host coal/rock and the difference between hydrostatic and cavity pressure. In this paper, we focus on thermal-hydrological processes, examining the relationship between combustion-driven heat generation, convective and conductive heat flow, and water influx, and examine how the thermal and hydrologic properties of the host coal/rock influence those relationships. Specifically, we conducted a parameter sensitivity analysis of the influence of thermal and hydrological properties of the host coal, caprock, and bedrock on cavity temperature and steam production.

Buscheck, T A; Hao, Y; Morris, J P; Burton, E A

2009-10-05T23:59:59.000Z

404

Thermal Noise Metrology  

Science Conference Proceedings (OSTI)

... of a one-port source and the ... from 8.2 gigahertz to 65 gigahertz for waveguide sources. ... remote-sensing measurements to primary noise standards. ...

2011-09-27T23:59:59.000Z

405

Thermal Flipping of Interstellar Grains  

E-Print Network (OSTI)

In interstellar dust grains, internal processes dissipate rotational kinetic energy. The dissipation is accompanied by thermal fluctuations, which transfer energy from the vibrational modes to rotation. Together, these processes are known as internal relaxation. For the past several years, internal relaxation has been thought to give rise to thermal flipping, with profound consequences for grain alignment theory. I show that thermal flipping is not possible in the limit that the inertia tensor does not vary with time.

Joseph C. Weingartner

2008-08-27T23:59:59.000Z

406

Quiescent thermal emission from neutron stars in LMXBs  

E-Print Network (OSTI)

The quiescent thermal emission from neutron stars in low mass X-ray binaries after active periods of intense activity in x-rays (outbursts) has been monitored. The theoretical modeling of the thermal relaxation of the neutron star crust may be used to establish constraints on the crust and envelope composition and transport properties, depending on the astrophysical scenarios assumed. We perform numerical simulations of the neutron star crust thermal evolution and compare them with inferred surface temperatures for five sources: MXB 1659-29, KS 1731-260, EXO 0748-676, XTE J1701-462 and IGR J17480-2446. We also present stationary envelope models to be used as a boundary condition for the crustal cooling models. We obtain a relation between the mass accretion rate and the temperature reached at the crust-envelope interface at the end of the active phase that accounts for early observations and reduces the number of free parameters of the problem. With this relation we are also able to set constraints to the envelope composition depending on the accretion mass rate. We find that the evolution of MXB 1659-29, KS 1731-260 and EXO 0748-676 can be well described within a deep crustal cooling scenario. Conversely, we find that other two sources can only be explained with models beyond crustal cooling. For the peculiar emission of XTE J1701-462 we propose alternative scenarios like residual accretion during quiescence, additional heat sources in the outer crust and/or thermal isolation of the inner crust due to a buried magnetic field. We also explain the very recent reported temperature of IGR J17480-2446 with an extra heat deposition in the outer crust coming from shallow sources.

Anabela Turlione; Deborah N. Aguilera; Jos A. Pons

2013-09-16T23:59:59.000Z

407

Paleomagnetic Measurements | Open Energy Information  

Open Energy Info (EERE)

Paleomagnetic Measurements Paleomagnetic Measurements Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Paleomagnetic Measurements Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Can determine detailed information about rock composition and morphology Stratigraphic/Structural: Historic structure and deformation of land Hydrological: Thermal: Dictionary.png Paleomagnetic Measurements: Paleomagnetism is the study of remnant magnetization in rocks. Paleomagnetic measurements are measurements of the magnetic properties in rocks; these properties are locked in during the formation of the rock. A

408

Actively driven thermal radiation shield  

DOE Patents (OSTI)

A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

Madden, Norman W. (Livermore, CA); Cork, Christopher P. (Pleasant Hill, CA); Becker, John A. (Alameda, CA); Knapp, David A. (Livermore, CA)

2002-01-01T23:59:59.000Z

409

Shock waves in thermal lensing  

E-Print Network (OSTI)

We review experimental investigation on spatial shock waves formed by the self-defocusing action of a laser beam propagation in a disordered thermal nonlinear media.

Gentilini, S; DeRe, E; Conti, C

2013-01-01T23:59:59.000Z

410

Thermal Barrier Coating Systems II  

Science Conference Proceedings (OSTI)

Oct 26, 2009... on the application requirements and not on substrate physical properties such as thermal expansion rate Esp. within the same class of alloys.

411

Thermal Oxidation of Titanium Wires  

Science Conference Proceedings (OSTI)

Structural and Thermal Study of Al2O3 Produced by Oxidation of Al-Powders Mixed with Corn Starch Study of Silicon Carbide/Silicon Nitride Composite...

412

Enhanced Thermal Conductivity Oxide Fuels  

SciTech Connect

the purpose of this project was to investigate the feasibility of increasing the thermal conductivity of oxide fuels by adding small fractions of a high conductivity solid phase.

Alvin Solomon; Shripad Revankar; J. Kevin McCoy

2006-01-17T23:59:59.000Z

413

Thermally activated miniaturized cooling system.  

E-Print Network (OSTI)

??A comprehensive study of a miniaturized thermally activated cooling system was conducted. This study represents the first work to conceptualize, design, fabricate and successfully test (more)

Determan, Matthew Delos

2008-01-01T23:59:59.000Z

414

Thermal barrier coatings  

DOE Patents (OSTI)

This disclosure addresses the issue of providing a metallic-ceramic overlay coating that potentially serves as an interface or bond coat layer to provide enhanced oxidation resistance to the underlying superalloy substrate via the formation of a diffusion barrier regime within the supporting base material. Furthermore, the metallic-ceramic coating is expected to limit the growth of a continuous thermally grown oxide (TGO) layer that has been primarily considered to be the principal cause for failure of existing TBC systems. Compositional compatibility of the metallic-ceramic with traditional yttria-stabilized zirconia (YSZ) top coats is provided to further limit debond or spallation of the coating during operational use. A metallic-ceramic architecture is disclosed wherein enhanced oxidation resistance is imparted to the surface of nickel-based superalloy or single crystal metal substrate, with simultaneous integration of the yttria stabilized zirconia (YSZ) within the metallic-ceramic overlayer.

Alvin, Mary Anne (Pittsburg, PA)

2010-06-22T23:59:59.000Z

415

Thermal protection apparatus  

DOE Patents (OSTI)

An apparatus for thermally protecting heat sensitive components of tools. The apparatus comprises a Dewar holding the heat sensitive components. The Dewar has spaced-apart inside walls, an open top end and a bottom end. A plug is located in the top end. The inside wall has portions defining an inside wall aperture located at the bottom of the Dewar and the outside wall has portions defining an outside wall aperture located at the bottom of the Dewar. A bottom connector has inside and outside components. The inside component sealably engages the inside wall aperture and the outside component sealably engages the outside wall aperture. The inside component is operatively connected to the heat sensitive components and to the outside component. The connections can be made with optical fibers or with electrically conducting wires.

Bennett, G.A.; Moore, T.K.

1986-08-20T23:59:59.000Z

416

SUPERFAST THERMALIZATION OF PLASMA  

DOE Patents (OSTI)

A method is given for the superfast thermalization of plasma by shock conversion of the kinetic energy stored in rotating plasma rings or plasmoids colliding at near supersonic speeds in a containment field to heat energy in the resultant confined plasma mass. The method includes means for generating rotating plasmoids at the opposite ends of a Pyrotron or Astron containment field. The plasmoids are magnetically accelerated towards each other into the opposite ends of time containment field. During acceleration of the plasmoids toward the center of the containment field, the intensity of the field is sequentially increased to adiabatically compress the plasmoids and increase the plasma energy. The plasmoids hence collide with a violent shock at the eenter of the containment field, causing the substantial kinetic energy stored in the plasmoids to be converted to heat in the resultant plasma mass. (AEC)

Chang, C.C.

1962-06-12T23:59:59.000Z

417

Underground Coal Thermal Treatment  

Science Conference Proceedings (OSTI)

The long-term objective of this work is to develop a transformational energy production technology by insitu thermal treatment of a coal seam for the production of substitute natural gas (SNG) while leaving much of the coal??s carbon in the ground. This process converts coal to a high-efficiency, low-GHG emitting gas fuel. It holds the potential of providing environmentally acceptable access to previously unusable coal resources. This topical report discusses the development of experimental capabilities, the collection of available data, and the development of simulation tools to obtain process thermo-chemical and geo-thermal parameters in preparation for the eventual demonstration in a coal seam. It also includes experimental and modeling studies of CO{sub 2} sequestration. Efforts focused on: ? Constructing a suite of three different coal pyrolysis reactors. These reactors offer the ability to gather heat transfer, mass transfer and kinetic data during coal pyrolysis under conditions that mimic in situ conditions (Subtask 6.1). ? Studying the operational parameters for various underground thermal treatment processes for oil shale and coal and completing a design matrix analysis for the underground coal thermal treatment (UCTT). This analysis yielded recommendations for terms of targeted coal rank, well orientation, rubblization, presence of oxygen, temperature, pressure, and heating sources (Subtask 6.2). ? Developing capabilities for simulating UCTT, including modifying the geometry as well as the solution algorithm to achieve long simulation times in a rubblized coal bed by resolving the convective channels occurring in the representative domain (Subtask 6.3). ? Studying the reactive behavior of carbon dioxide (CO{sub 2}) with limestone, sandstone, arkose (a more complex sandstone) and peridotite, including mineralogical changes and brine chemistry for the different initial rock compositions (Subtask 6.4). Arkose exhibited the highest tendency of participating in mineral reactions, which can be attributed to the geochemical complexity of its initial mineral assemblage. In experiments with limestone, continuous dissolution was observed with the release of CO{sub 2} gas, indicated by the increasing pressure in the reactor (formation of a gas chamber). This occurred due to the lack of any source of alkali to buffer the solution. Arkose has the geochemical complexity for permanent sequestration of CO{sub 2} as carbonates and is also relatively abundant. The effect of including NH{sub 3} in the injected gas stream was also investigated in this study. Precipitation of calcite and trace amounts of ammonium zeolites was observed. A batch geochemical model was developed using Geochemists Workbench (GWB). Degassing effect in the experiments was corrected using the sliding fugacity model in GWB. Experimental and simulation results were compared and a reasonable agreement between the two was observed.

P. Smith; M. Deo; E. Eddings; A. Sarofim; K. Gueishen; M. Hradisky; K. Kelly; P. Mandalaparty; H. Zhang

2011-10-30T23:59:59.000Z

418

Thermal Stabilization Blend Plan  

SciTech Connect

The Blend Plan was written to identify items stored outside of the 213 MBA that will be moved into the MBA for thermal stabilization processing. Product quality oxide items stored in our vaults are found in Appendix B. A table is included in Appendix B which details the isotopic values for the oxide items and calculates the amount of material of any specific run that can be placed in a product can and maintain the 15 watt limit to meet storage vault specifications. There is no chance of exceeding the 15 watt limit with items starting with the designations ''LAO'' or ''PBO.'' All items starting with the designations ''BO,'' ''BLO,'' and ''DZ0'' are at risk of exceeding the 15 watt specification if the can were to be filled.

RISENMAY, H.R.

1999-08-19T23:59:59.000Z

419

Thermally stabilized heliostat  

DOE Patents (OSTI)

An improvement in a heliostat having a main support structure and pivoting and tilting motors and gears and a mirror module for reflecting solar energy onto a collector, the improvement being characterized by an internal support structure within each mirror module and front and back sheets attached to the internal support structure, the front and back sheets having the same coefficient of thermal expansion such that no curvature is induced by temperature change, and a layer of adhesive adhering the mirror to the front sheet. The adhesive is water repellent and has adequate set strength to support the mirror but has sufficient shear tolerance to permit the differential expansion of the mirror and the front sheet without inducing stresses or currature effect. The adhesive also serves to dampen fluttering of the mirror and to protect the mirror backside against the adverse effects of weather. Also disclosed are specific details of the preferred embodiment.

Anderson, Alfred J. (Littleton, CO)

1983-01-01T23:59:59.000Z

420

Nitrogen heat pipe for cryocooler thermal shunt  

SciTech Connect

A nitrogen heat pipe was designed, built and tested for the purpose of providing a thermal shunt between the two stages of a Gifford-McMahan (GM) cryocooler during cooldown. The nitrogen heat pipe has an operating temperature range between 63 and 123 K. While the heat pipe is in the temperature range during the system cooldown, it acts as a thermal shunt between the first and second stage of the cryocooler. The heat pipe increases the heat transfer to the first stage of the cryocooler, thereby reducing the cooldown time of the system. When the heat pipe temperature drops below the triple point, the nitrogen working fluid freezes, effectively stopping the heat pipe operation. A small heat leak between cryocooler stages remains because of axial conduction along the heat pipe wall. As long as the heat pipe remains below 63 K, the heat pipe remains inactive. Heat pipe performance limits were measured and the optimum fluid charge was determined.

Prenger, F.C.; Hill, D.D.; Daney, D.E.; Daugherty, M.A. [Los Alamos National Lab., NM (United States); Green, G.F.; Roth, E.W. [Naval Surface Warfare Center, Annapolis, MD (United States)

1995-09-01T23:59:59.000Z

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


421

Green's function of the cosmological thermalization problem  

E-Print Network (OSTI)

Energy release in the early Universe leads to spectral distortions of the cosmic microwave background (CMB) which in the future might allow probing different physical processes in the pre-recombination (z>~10^3) epoch. Depending on the energy injection history, the associated distortion partially thermalizes due to the combined action of Compton scattering, double Compton scattering and Bremsstrahlung emission, a problem that in general is hard to solve. Various analytic approximations describing the resulting distortion exist, however, for small distortions and fixed background cosmology the Green's function of the problem can be computed numerically. Here we show that this approach gives very accurate results for general thermal histories, allowing fast and quasi-exact computation of the spectral distortion given the energy release rate. Our method can thus be used to forecast possible constraints on early-universe physics obtained from future measurements of the CMB spectrum.

Chluba, Jens

2013-01-01T23:59:59.000Z

422

Hall-Hroult Cell: Processes Modeling and Measurements  

Science Conference Proceedings (OSTI)

Feb 17, 2010 ... The thermal balance has a direct impact in current efficiency, however its measures are subjected to hardware and human errors, and normally...

423

Thermal sensation and comfort in transient non-uniform thermal environments  

E-Print Network (OSTI)

cooling applied cooling removed Thermal Sensation Skincooling = 14C cooling removed Thermal Sensation We measureda hand cooling test Models to predict thermal sensation and

Zhang, Hui; Huizenga, Charlie; Arens, Edward; Wang, Danni

2004-01-01T23:59:59.000Z

424

Thermal sensation and comfort in transient non-uniform thermal environments  

E-Print Network (OSTI)

environments. and evaluating thermal 6.0 References AttiaM, Engel P (1981) Thermal alliesthesial response in man isof vehicle climate with a thermal manikin - the relationship

Zhang, Hui; Huizenga, Charlie; Arens, Edward; Wang, Danni

2004-01-01T23:59:59.000Z

425

Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants  

E-Print Network (OSTI)

STUDY FOR SOLAR THERMAL POWER PLANTS, Ottawa, Ontario: 1999.Concentrated Solar Thermal Power Plants A Thesis submittedConcentrated Solar Thermal Power Plants by Corey Lee Hardin

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

426

Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants  

E-Print Network (OSTI)

PHASE CHANGE THERMAL ENERGY STORAGE FOR CONCENTRATING SOLARChange Materials for Thermal Energy Storage in ConcentratedChange Materials for Thermal Energy Storage in Concentrated

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

427

Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants  

E-Print Network (OSTI)

PHASE CHANGE THERMAL ENERGY STORAGE FOR CONCENTRATING SOLARMaterials for Thermal Energy Storage in Concentrated SolarMaterials for Thermal Energy Storage in Concentrated Solar

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

428

Thermal Correction to the Molar Polarizability of a Boltzmann Gas  

E-Print Network (OSTI)

Metrology in atomic physics has been crucial for a number of advanced determinations of fundamental constants. In addition to very precise frequency measurements, the molar polarizability of an atomic gas has recently also been measured very accurately. Part of the motivation for the measurements is due to ongoing efforts to redefine the International System of Units (SI) for which an accurate value of the Boltzmann constant is needed. Here, we calculate the dominant shift of the molar polarizability in an atomic gas due to thermal effects. It is given by the relativistic correction to the dipole interaction, which emerges when the probing electric field is Lorenz transformed into the rest frame of the atoms that undergo thermal motion. While this effect is small when compared to currently available experimental accuracy, the relativistic correction to the dipole interaction is much larger than the thermal shift of the polarizability induced by blackbody radiation.

Jentschura, U D; Mohr, P J

2013-01-01T23:59:59.000Z

429

Thermal Correction to the Molar Polarizability of a Boltzmann Gas  

E-Print Network (OSTI)

Metrology in atomic physics has been crucial for a number of advanced determinations of fundamental constants. In addition to very precise frequency measurements, the molar polarizability of an atomic gas has recently also been measured very accurately. Part of the motivation for the measurements is due to ongoing efforts to redefine the International System of Units (SI) for which an accurate value of the Boltzmann constant is needed. Here, we calculate the dominant shift of the molar polarizability in an atomic gas due to thermal effects. It is given by the relativistic correction to the dipole interaction, which emerges when the probing electric field is Lorenz transformed into the rest frame of the atoms that undergo thermal motion. While this effect is small when compared to currently available experimental accuracy, the relativistic correction to the dipole interaction is much larger than the thermal shift of the polarizability induced by blackbody radiation.

U. D. Jentschura; M. Puchalski; P. J. Mohr

2013-09-09T23:59:59.000Z

430

Magnetohydrodynamic evolution of magnetic skeletons  

E-Print Network (OSTI)

The heating of the solar corona is likely to be due to reconnection of the highly complex magnetic field that threads throughout its volume. We have run a numerical experiment of an elementary interaction between the magnetic field of two photospheric sources in an overlying field that represents a fundamental building block of the coronal heating process. The key to explaining where, how and how much energy is released during such an interaction is to calculate the resulting evolution of the magnetic skeleton. A skeleton is essentially the web of magnetic flux surfaces (called separatrix surfaces) that separate the coronal volume into topologically distinct parts. For the first time the skeleton of the magnetic field in a 3D numerical MHD experiment is calculated and carefully analysed, as are the ways in which it bifurcates into different topologies. A change in topology normally changes the number of magnetic reconnection sites. In our experiment, the magnetic field evolves through a total of six distinct topologies. Initially, no magnetic flux joins the two sources. Then a new type of bifurcation, called a global double-separator bifurcation, takes place: this bifurcation is likely to be one of the main ways in which new separators are created in the corona (separators are field lines at which 3D reconnection takes place). This is the first of five bifurcations in which the skeleton becomes progressively more complex before simplifying. Surprisingly, for such a simple initial state, at the peak of complexity there are five separators and eight flux domains present.

Andrew L. Haynes; Clare E. Parnell; Klaus Galsgaard; Eric R. Priest

2007-02-22T23:59:59.000Z

431

Chemical evolution with radial mixing  

E-Print Network (OSTI)

Models of the chemical evolution of our Galaxy are extended to include radial migration of stars and flow of gas through the disc. The models track the production of both iron and alpha elements. A model is chosen that provides an excellent fit to the metallicity distribution of stars in the Geneva-Copenhagen survey (GCS) of the solar neighbourhood, and an acceptable fit to the local Hess diagram. The model provides a good fit to the distribution of GCS stars in the age-metallicity plane although this plane was not used in the fitting process. Although this model's star-formation rate is monotonic declining, its disc naturally splits into an alpha-enhanced thick disc and a normal thin disc. In particular the model's distribution of stars in the ([O/Fe],[Fe/H]) plane resembles that of Galactic stars in displaying a ridge line for each disc. The thin-disc's ridge line is entirely due to stellar migration and there is the characteristic variation of stellar angular momentum along it that has been noted by Haywoo...

Schoenrich, Ralph

2008-01-01T23:59:59.000Z

432

Peg supported thermal insulation panel  

DOE Patents (OSTI)

A thermal insulation panel which is lightweight, load bearing, accommodates thermal stress, and has excellent high temperature insulation capability comprising high performance insulation between thin metal walls supported by high density, high strength glass pegs made in compliance with specified conditions of time, temperature and pressure.

Nowobilski, Jeffert J. (Orchard Park, NY); Owens, William J. (Kenmore, NY)

1985-01-01T23:59:59.000Z

433

Peg supported thermal insulation panel  

DOE Patents (OSTI)

A thermal insulation panel which is lightweight, load bearing, accommodates thermal stress, and has excellent high temperature insulation capability comprises high performance insulation between thin metal walls supported by high density, high strength glass pegs made in compliance with specified conditions of time, temperature and pressure. 2 figs.

Nowobilski, J.J.; Owens, W.J.

1985-04-30T23:59:59.000Z

434

Solar Thermal Electric Technology: 2009  

Science Conference Proceedings (OSTI)

This report summarizes the status and progress of the solar thermal and concentrating solar power (CSP) industry in 2009. It addresses relevant policies in the United States and internationally, technology status, trends, companies and organizations involved in the field, and modeling activities supported by the Electric Power Research Institute (EPRI) and the Solar Thermal Electric Project (STEP).

2010-06-23T23:59:59.000Z

435

Solar Thermal Electric Technology: 2008  

Science Conference Proceedings (OSTI)

This report summarizes the status and progress of the solar thermal and concentrating solar power (CSP) industry in 2008. It addresses technology status, trends, companies and organizations involved in the field, and modeling activities supported by EPRI and the Solar Thermal Electric Project (STEP).

2009-03-31T23:59:59.000Z

436

Multiple-code simulation study of the long-term EDZ evolution of geological nuclear waste repositories  

SciTech Connect

This simulation study shows how widely different model approaches can be adapted to model the evolution of the excavation disturbed zone (EDZ) around a heated nuclear waste emplacement drift in fractured rock. The study includes modeling of coupled thermal-hydrological-mechanical (THM) processes, with simplified consideration of chemical coupling in terms of time-dependent strength degradation or subcritical crack growth. The different model approaches applied in this study include boundary element, finite element, finite difference, particle mechanics, and elastoplastic cellular automata methods. The simulation results indicate that thermally induced differential stresses near the top of the emplacement drift may cause progressive failure and permeability changes during the first 100 years (i.e., after emplacement and drift closure). Moreover, the results indicate that time-dependent mechanical changes may play only a small role during the first 100 years of increasing temperature and thermal stress, whereas such time-dependency is insignificant after peak temperature, because decreasing thermal stress.

Rutqvist, J.; Backstrom, A.; Chijimatsu, M.; Feng, X.-T.; Pan, P.-Z.; Hudson, J.; Jing, L.; Kobayashi, A.; Koyama, T.; Lee, H.-S.; Huang, X.-H.; Rinne, M.; Shen, B.

2008-10-23T23:59:59.000Z

437

Measurement of gas temperature field in a flame spreading over solid fuel.  

E-Print Network (OSTI)

??An experimental measurement is developed to measure the gas temperature field in a flame spreading downward over thermally thin filter paper. A flame stabilizer apparatus (more)

Alghamdi, Abdulaziz Othman

2012-01-01T23:59:59.000Z

438

Near-field thermal transistor  

E-Print Network (OSTI)

Using a block of three separated solid elements, a thermal source and drain together with a gate made of an insulator-metal transition material exchanging near-field thermal radiation, we introduce a nanoscale analog of a field-effect transistor which is able to control the flow of heat exchanged by evanescent thermal photons between two bodies. By changing the gate temperature around its critical value, the heat flux exchanged between the hot body (source) and the cold body (drain) can be reversibly switched, amplified, and modulated by a tiny action on the gate. Such a device could find important applications in the domain of nanoscale thermal management and it opens up new perspectives concerning the development of contactless thermal circuits intended for information processing using the photon current rather than the electric current.

Ben-Abdallah, Philippe

2013-01-01T23:59:59.000Z

439

Investigation of the rank dependence of tar evolution  

SciTech Connect

The objective of this study are to develop an improved understanding of the process of coal tar evolution, its relationship to the structural characteristics of the parent coal, and the dependence of the chemical and physical properties of the tar products on the conditions of devolatilization. Data from this study are expected to allow hypothesis testing and refinements of coal devolatilization models relevant to the pulverized coal combustion process. A range of coal ranks, from a Texas lignite to a Pennsylvania anthracite, are employed in the investigation. In addition, a high temperature polymer, a polyimide, is utilized as an additional reference case. The polyimide serves as a truly polymeric reference material for examining the nitrogen evolution behavior of coal. The samples are subjected to elemental composition determination, infrared absorbance characterization, calorific value measurement, high temperature ash analysis, and maceral composition. Potential tar yields are determined by long hold time heated grid investigations of each coal at a final temperature and heating rate observed to maximize tar yields for the reference coal. Relative tar evolution kinetic behavior is determined by zero hold time heated grid investigations of each coal. 4 refs., 13 figs., 2 tabs.

Freihaut, J.D.; Proscia, W.M.

1990-01-01T23:59:59.000Z

440

Synthesis and textural evolution of alumina particles with mesoporous structures  

Science Conference Proceedings (OSTI)

Alumina particles with mesostructures were synthesized through a chemical precipitation method by using different inorganic aluminum salts followed by a heterogeneous azeotropic distillation and calcination process. The obtained mesoporous {gamma}-alumina particles were systematically characterized by the X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption measurement. Effects of the aluminum salt counter anion, pH value and the azeotropic distillation process on the structural or textural evolution of alumina particles were investigated. It is found that Cl{sup -} in the reaction solution can restrain the textural evolution of the resultant precipitates into two-dimensional crystallized pseudoboehmite lamellae during the heterogeneous azeotropic distillation, and then transformed into {gamma}-Al{sub 2}O{sub 3} particles with mesostructures after further calcination at 1173 K, whereas coexisting SO{sub 4}{sup 2-} can promote above morphology evolution and then transformed into {gamma}-Al{sub 2}O{sub 3} nanofibers after calcination at 1173 K. Moreover nearly all materials retain relatively high specific surface areas larger than 100 m{sup 2} g{sup -1} even after calcinations at 1173 K. - Graphical abstract: Co-existing Cl{sup -} is beneficial for the formation of {gamma}-alumina nanoparticles with mesostructures during the precipitation process. Interparticle and intraparticle mesopores can be derived from acidic solution and near neutral solution, respectively.

Liu Xun [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Peng Tianyou, E-mail: typeng@whu.edu.c [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Yao Jinchun; Lv Hongjin; Huang Cheng [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China)

2010-06-15T23:59:59.000Z

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


441

POST-FLARE ULTRAVIOLET LIGHT CURVES EXPLAINED WITH THERMAL INSTABILITY OF LOOP PLASMA  

Science Conference Proceedings (OSTI)

In the present work, we study the C8 flare that occurred on 2000 September 26 at 19:49 UT and observed by the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation spectrometer from the beginning of the impulsive phase to well beyond the disappearance in the X-rays. The emission first decayed progressively through equilibrium states until the plasma reached 2-3 MK. Then, a series of cooler lines, i.e., Ca X, Ca VII, Ne VI, O IV, and Si III (formed in the temperature range log T = 4.3-6.3 under equilibrium conditions), are emitted at the same time and all evolve in a similar way. Here, we show that the simultaneous emission of lines with such a different formation temperature is due to thermal instability occurring in the flaring plasma as soon as it has cooled below {approx}2 MK. We can qualitatively reproduce the relative start time of the light curves of each line in the correct order with a simple (and standard) model of a single flaring loop. The agreement with the observed light curves is greatly improved, and a slower evolution of the line emission is predicted, if we assume that the model loop consists of an ensemble of subloops or strands heated at slightly different times. Our analysis can be useful for flare observations with the Solar Dynamics Observatory/Extreme ultraviolet Variability Experiment.

Reale, F. [Dipartimento di Fisica, Universita degli Studi di Palermo, Piazza del Parlamento 1, 90134 Palermo (Italy); Landi, E. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Orlando, S. [INAF-Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo (Italy)

2012-02-10T23:59:59.000Z

442

The Evolution of Stellar Mass Density and its Implied Star Formation History  

E-Print Network (OSTI)

Using a compilation of measurements of the stellar mass density as a function of redshift we can infer the cosmic star formation history. For z histories. At higher redshifts the instantaneous indicators suggest star formation rates larger than that implied by the evolution of the stellar mass density. This discrepancy peaks at z = 3 where instantaneous indicators suggest a star formation rate around 0.6 dex higher than those of the best fit to the stellar mass history. We discuss a variety of explanations for this inconsistency, such as inaccurate dust extinction corrections, incorrect measurements of stellar masses and a possible evolution of the stellar initial mass function.

S. M. Wilkins; N. Trentham; A. M. Hopkins

2008-03-27T23:59:59.000Z

443

Thermalization in harmonic particle chains with velocity flips  

E-Print Network (OSTI)

We propose a new mathematical tool for the study of transport properties of models for lattice vibrations in crystalline solids. By replication of dynamical degrees of freedom, we aim at a new dynamical system where the "local" dynamics can be isolated and solved independently from the "global" evolution. The replication procedure is very generic but not unique as it depends on how the original dynamics are split between the local and global dynamics. As an explicit example, we apply the scheme to study thermalization of the pinned harmonic chain with velocity flips. We improve on the previous results about this system by showing that after a relatively short time period the average kinetic temperature profile satisfies the dynamic Fourier's law in a local microscopic sense without assuming that the initial data is close to a local equilibrium state. The bounds derived here prove that the above thermalization period is at most of the order L^(2/3), where L denotes the number of particles in the chain. In particular, even before the diffusive time scale Fourier's law becomes a valid approximation of the evolution of the kinetic temperature profile. As a second application of the dynamic replica method, we also briefly discuss replacing the velocity flips by an anharmonic onsite potential.

Jani Lukkarinen

2013-08-22T23:59:59.000Z

444

D17: Thermal Measurements of 3- and 4-Phase Ceramic ...  

Science Conference Proceedings (OSTI)

Abstract Scope, This project investigates using Object Oriented Finite Element Analysis Version 2 ... A16: Analysis of Surface Physic-Chemical Properties of Titanium Heat Treated ... B2: Investigation of Increasing Titanium Dioxide on Structural Changes in ... C9: Molten Salts Activated by High Energy Milling: a Useful,...

445

Thermal Conductivity Spectroscopy Technique to Measure Phonon Mean Free Paths  

E-Print Network (OSTI)

Size effects in heat conduction, which occur when phonon mean free paths (MFPs) are comparable to characteristic lengths, are being extensively explored in many nanoscale systems for energy applications. Knowledge of MFPs ...

Schmidt, A. J.

446

012- Measurement of Thermal Conductivity of Basic Refractories ...  

Science Conference Proceedings (OSTI)

085- Highly Efficient Comprehensive Utilization of Kaolin Tailings from ... 086- Improvement in Gas Tightness of YSZ Coatings Produced by Atmospheric Plasma Spraying ... 145- The Synergy of XRD and XRF in a Shale and Slate Analysis.

447

Infrared Thermography Measurements of Window Thermal Test Specimen Surface Temperatures  

E-Print Network (OSTI)

. Griffith ASHRAE Member, Howdy Goudey, and Dariush Arasteh P.E. ASHRAE Member Building Technologies Program. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) temperature conditions

448

ARM - Measurements  

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

Select below to highlight measurements in specified measurement categories. Aerosols The effect of aerosols is measured by instrument systems and lidars that provide data...

449

Thermally induced structural changes in coal combustion  

DOE Green Energy (OSTI)

The project objectives are (1) to measure the effect of devolatilization temperature and time on properties of the char and (2) characterize and quantify the effect of thermal annealing on char reactivity during char burnout under conditions of pulverized combustion. Coal devolatilization runs continued during the reporting period. Elemental analysis and N{sub 2} BET surface areas measurements were carried out on the three chars produced in the devolatilization runs. The results are presented. Experiments in the electrodynamic balance during the reporting period were focused on developing ways to measure the particle mass loss and, therefore, the reaction rate directly. This work is summarized in the attached Appendix. 4 refs., 1 fig., 1 tab.

Gavalas, G.R.; Flagan, R.C.

1990-12-07T23:59:59.000Z

450

Thermal bremsstrahlung probing the nuclear liquid-gas phase transition  

E-Print Network (OSTI)

We present the results of the analysis of the hard photon production in the $^{129}${Xe}+$^{\\rm nat}${Sn} at 50{\\it A} MeV system studied in the GANIL E300 experiment. The energy and angular hard photon distributions confirm the existence of a thermal component which follows the recently measured thermal bremsstrahlung systematics. Exploiting the performances of our complete detection system, consisting of TAPS and 3 charged particle multidetectors, we have also measured the hard photon multiplicity as a function of the charged particle multiplicity.

R. Ortega; D. d'Enterria; F. Fernandez; G. Martinez

2002-02-28T23:59:59.000Z

451

Thermal to electricity conversion using thermal magnetic properties  

DOE Patents (OSTI)

A system for the generation of Electricity from Thermal Energy using the thermal magnetic properties of a Ferromagnetic, Electrically Conductive Material (FECM) in one or more Magnetic Fields. A FECM is exposed to one or more Magnetic Fields. Thermal Energy is applied to a portion of the FECM heating the FECM above its Curie Point. The FECM, now partially paramagnetic, moves under the force of the one or more Magnetic Fields. The movement of the FECM induces an electrical current through the FECM, generating Electricity.

West, Phillip B [Idaho Falls, ID; Svoboda, John [Idaho Falls, ID

2010-04-27T23:59:59.000Z

452

Designing a Thermal Energy Storage Program for Electric Utilities  

E-Print Network (OSTI)

Electric utilities are looking at thermal energy storage technology as a viable demand side management (DSM) option. In order for this DSM measure to be effective, it must be incorporated into a workable, well-structured utility program. This paper describes a methodology to design a successful thermal energy storage program for electric utilities. The design process is addressed beginning with the market research phase. The research includes information obtained from utilities having successful thermal storage programs. In addition, information is gathered from interviews with local architects and engineers, air conditioning contractors and potential thermal energy storage customers. From this information a marketing plan is developed that addresses the target market, market penetration, promotional methods, incentive types and levels, internal and external training requirements and optimal organizational structure. The marketing plan also includes various rate structures, program procedures and evaluation techniques. In addition to the marketing plan, several case histories are addressed.

Niehus, T. L.

1994-01-01T23:59:59.000Z

453

Geochemical Sampling of Thermal Waters in Nevada | Open Energy Information  

Open Energy Info (EERE)

Geochemical Sampling of Thermal Waters in Nevada Geochemical Sampling of Thermal Waters in Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Geochemical Sampling of Thermal Waters in Nevada Abstract There are 1000 thermal springs in Nevada for which a location is known, but for which there are no available temperature (or chemical) measurements. Although many of these sites are within known geothermal areas and are located near springs for which temperature and/or geochemical data are available for one of the springs, many of these sites are not so located and require evaluation before the geothermal potential of the area can be assessed. In order to begin filling in data gaps, water sampling commenced in 2002 when over 70 analyses were obtained from springs with previously

454

Thermally-induced microstructural changes in a three-way automotive catalyst  

DOE Green Energy (OSTI)

The use of advanced electron microscopy techniques to characterize both the bulk and near-atomic level microstructural evolution of catalyst materials during different dynamometer/vehicle aging cycles is an integral part of understanding catalyst deactivation. The study described here was undertaken to evaluate thermally-induced microstructural changes which caused the progressive loss of catalyst performance in a three-way automotive catalyst. Several different catalyst processing variables, for example changing the washcoat ceria content, were also evaluated as a function of aging cycle and thermal history. A number of thermally-induced microstructural changes were identified using high resolution electron microscopy techniques that contributed to the deactivation of the catalyst, including sintering of all washcoat constituents, {gamma}-alumina transforming to {alpha}-, {beta}-, and {delta}-alumina, precious metal redistribution, and constituent encapsulation. The data accumulated in this study have been used to correlate microstructural evolution with thermal history and catalyst performance during various aging cycles and to subsequently evaluate different washcoat formulations for increased thermal stability.

More, K.L.; Kenik, E.A.; Coffey, D.W.; Geer, T.S. [Oak Ridge National Lab., TN (United States); Theis, J.; LaBarge, W.; Beckmeyer, R. [Delphi Automotive Systems, Flint, MI (United States)

1997-12-01T23:59:59.000Z

455

Cesium capsule thermal analysis  

SciTech Connect

Double-walled stainless steel capsules, produced by the Hanford Waste Encapsulation and Storage Facility (WESF), were designed to facilitate storage of radioactive cesium chloride (CsCl). The capsules were later determined to be a useful resource for irradiation facilities (IFs), and are currently being used at several commercial IFs. A capsule at one of these facilities recently failed, resulting in a release of the CsCl. A thermal analysis of a WESF capsule was performed by Pacific Northwest Laboratory (PNL) at the request of Westinghouse Hanford Company. In this analysis, parametric calculations demonstrates the impact that various parameters have on the temperature distribution within a capsule in a commercial irradiation facility. Specifically, the effect of varying the gas gap conductivity, the exterior heat sink temperatures, the exterior heat transfer distribution, the stainless steel emissivity, and the gamma heating rate were addressed. In addition, a calculation was performed to estimate the highest temperatures likely to have been encountered in one of these capsules. 8 refs., 17 figs., 4 tabs.

Eyler, L.L.; Dodge, R.E.

1989-12-01T23:59:59.000Z

456

Thermally activated heat pumps  

SciTech Connect

This article describes research to develop efficient gas-fired heat pumps heat and cool buildings without CFCs. Space heating and cooling use 46% of all energy consumed in US buildings. Air-conditioning is the single leading cause of peak demand for electricity and is a major user of chlorofluorocarbons (CFCs). Advanced energy conversion technology can save 50% of this energy and eliminate CFCs completely. Besides saving energy, advanced systems substantially reduce emissions of carbon dioxide (a greenhouse gas), sulfur dioxide, and nitrogen oxides, which contribute to smog and acid rain. These emissions result from the burning of fossil fuels used to generate electricity. The Office of Building Technologies (OBT) of the US Department of Energy supports private industry`s efforts to improve energy efficiency and increase the use of renewable energy in buildings. To help industry, OBT, through the Oak Ridge National Laboratory, is currently working on thermally activated heat pumps. OBT has selected the following absorption heat pump systems to develop: generator-absorber heat-exchange (GAX) cycle for heating-dominated applications in residential and light commercial buildings; double-condenser-coupled (DCC) cycle for commercial buildings. In addition, OBT is developing computer-aided design software for investigating the absorption cycle.

NONE

1995-05-01T23:59:59.000Z

457

Nowcasts of Thunderstorm Initiation and Evolution  

Science Conference Proceedings (OSTI)

This paper reports on experimental space-specific 30-min nowcasts of thunderstorm initiation, evolution, and movement. The experiments were conducted near Denver, Colorado, with the purpose of providing weather information for planning purposes ...

James W. Wilson; Cynthia K. Mueller

1993-03-01T23:59:59.000Z

458

Evolution of US air cargo productivity  

E-Print Network (OSTI)

This thesis provides an overview of the US air cargo industry since airline deregulation in 1978, including a brief overview of the historical evolution of air cargo transport in the US from the early 1900s until the late ...

Donatelli, David J

2012-01-01T23:59:59.000Z

459

Metromorphosis : evolution on the urban island  

E-Print Network (OSTI)

Cities are very much alive. Like islands, they provide a natural testing ground for evolution. With more than half of the world's population living in urban areas now, the influence cities have on the planet's life is ...

Vezina, Kenrick (Kenrick Freitas)

2011-01-01T23:59:59.000Z

460

Dynamic archive evolution strategy for multiobjective optimization  

Science Conference Proceedings (OSTI)

This paper proposes a new multiobjective evolutionary approachthe dynamic archive evolution strategy (DAES) to investigate the adaptive balance between proximity and diversity. In DAES, a novel dynamic external archive is proposed to store elitist ...

Yang Shu Min; Shao Dong Guo; Luo Yang Jie

2005-03-01T23:59:59.000Z

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461

Observations of the Evolution of Orogenic Blocking  

Science Conference Proceedings (OSTI)

The evolution of low-level flow upstream of the Continental Divide (Rocky Mountains) and the Wasatch Range from being unable to surmount the mountain range, to becoming unblocked and blocked again is studied observationally. During two months in ...

Georg J. Mayr; Thomas B. McKee

1995-05-01T23:59:59.000Z

462

Big data : evolution, components, challenges and opportunities  

E-Print Network (OSTI)

This work reviews the evolution and current state of the "Big Data" industry, and to understand the key components, challenges and opportunities of Big Data and analytics face in today business environment, this is analyzed ...

Zarate Santovena, Alejandro

2013-01-01T23:59:59.000Z

463

Evolution and statistics of biological regulatory networks  

E-Print Network (OSTI)

In this thesis, I study the process of evolution of the gene regulatory network in Escherichia coli. First, I characterize the portion of the network that has been documented, and then I simulate growth of the network. In ...

Chandalia, Juhi Kiran, 1979-

2005-01-01T23:59:59.000Z

464

Microstructure, Mechanical and Electrical Properties Evolution ...  

Science Conference Proceedings (OSTI)

... evolution and a number of utility properties of finished sheets were examined. ... Changes in Microstructure During High Strain Rate Superplastic ..... and Validation of New Thermodynamic and Mobility Databases for Aluminium Alloys.

465