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1

Manipulation of Thermal Phonons  

E-Print Network [OSTI]

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...

Hsu, Chung-Hao

2013-03-28T23:59:59.000Z

2

Phonon thermal transport through tilt grain boundaries in strontium titanate  

SciTech Connect (OSTI)

In this work, we perform nonequilibrium molecular dynamics simulations to study phonon scattering at two tilt grain boundaries (GBs) in SrTiO{sub 3}. Mode-wise energy transmission coefficients are obtained based on phonon wave-packet dynamics simulations. The Kapitza conductance is then quantified using a lattice dynamics approach. The obtained results of the Kapitza conductance of both GBs compare well with those obtained by the direct method, except for the temperature dependence. Contrary to common belief, the results of this work show that the optical modes in SrTiO{sub 3} contribute significantly to phonon thermal transport, accounting for over 50% of the Kapitza conductance. To understand the effect of the GB structural disorder on phonon transport, we compare the local phonon density of states of the atoms in the GB region with that in the single crystalline grain region. Our results show that the excess vibrational modes introduced by the structural disorder do not have a significant effect on phonon scattering at the GBs, but the absence of certain modes in the GB region appears to be responsible for phonon reflections at GBs. This work has also demonstrated phonon mode conversion and simultaneous generation of new modes. Some of the new modes have the same frequency as the initial wave packet, while some have the same wave vector but lower frequencies.

Zheng, Zexi; Chen, Xiang; Yang, Shengfeng; Xiong, Liming; Chen, Youping [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States); Deng, Bowen; Chernatynskiy, Aleksandr [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2014-08-21T23:59:59.000Z

3

Acoustic phonon engineering of thermal properties of silicon-based nanostructures  

E-Print Network [OSTI]

with the high electrical conductivity and low thermal conductivity [7]. It has been shown theoretically investigate the influence of the cladding materials on the phonon thermal conductivity in Si-based planar thermal conduction in the Si-based planar heterostructures and rectangular hetero-nanowires. The phonon

4

Ballistic phonon thermal conductance in graphene nano-ribbon: First-principles calculations  

SciTech Connect (OSTI)

Ballistic phonon thermal conductances for graphene nanoribbons are investigated using first-principles calculations with the density functional perturbation theory and the Landauer theory. The phonon thermal conductance per unit width for GNR is larger than that for graphene and increases with decreasing ribbon width. The normalized thermal conductances with regard to a thermal quantum for GNRs are higher than those for the single-walled carbon nanotube that have circumferential lengths corresponding to the width of GNR.

Nakamura, Jun; Tomita, Hiroki [Department of Engineering Sciences, The University of Electro-Communications (UEC-Tokyo), 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585 (Japan)

2013-12-04T23:59:59.000Z

5

Spectral inhomogeneity induced by vacancies and thermal phonons and associated observables in time-and frequency-domain nonlinear  

E-Print Network [OSTI]

Spectral inhomogeneity induced by vacancies and thermal phonons and associated observables in time by vacancies and thermally populated phonons, specializing to molecular iodine isolated in an Ar matrix. At experimentally relevant temperatures, for a vacancy concentration of 1.4%, both defect-induced and phonon

Apkarian, V. Ara

6

INTERFACES AND BOUNDARIES THE SOLID-SOLID INTERFACE IN THERMAL PHONON RADIATION  

E-Print Network [OSTI]

materials as it happens if a metal film deposited on a dielectric crystal is heated and emits thermal pho the thermal boundary resistance predicted by this (>.But no convicting resultsINTERFACES AND BOUNDARIES THE SOLID-SOLID INTERFACE IN THERMAL PHONON RADIATION Institute fiir

Paris-Sud XI, Université de

7

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.

8

Electron-Phonon Coupling and Thermal Conductance at a Metal-Semiconductor Interface: First-principles Analysis  

E-Print Network [OSTI]

The mechanism of heat transfer and the contribution of electron-phonon coupling to thermal conductance of a metal-semiconductor interface remains unclear in the present literature. We report ab initio simulations of a technologically important titanium silicide (metal) - silicon (semiconductor) interface to estimate the Schottky barrier height (SBH), and the strength of electron-phonon and phonon-phonon heat transfer across the interface. The electron and phonon dispersion relations of TiSi$_2$ with C49 structure and the TiSi$_2$-Si interface are obtained using first-principles calculations within the density functional theory (DFT) framework. These are used to estimate electron-phonon linewidths and the associated Eliashberg function that quantifies coupling. We show that the coupling strength of electrons with interfacial phonon modes is of the same order of magnitude as coupling of electrons to phonon modes in the bulk metal, and its contribution to electron-phonon interfacial conductance is comparable to ...

Sadasivam, Sridhar; Fisher, Timothy S

2015-01-01T23:59:59.000Z

9

Thermally stimulated 3–15 THz emission at plasmon-phonon frequencies in polar semiconductors  

SciTech Connect (OSTI)

The possibilities of distinguishing highly coherent terahertz emission at a specified frequency from the incoherent thermal emission of a hot body are considered. It is experimentally shown that the smooth planar surface (with no diffraction guides) of heated GaAs and AlGaAs wafers emits directed continuous-wave (cw) terahertz radiation at coupled surface plasmon-phonon vibrational frequencies. The recording of terahertz reflectance spectra is demonstrated as a method for the identification of plasmons, optical phonons, and coupled plasmon-phonon vibrations in semiconductors.

Požela, J., E-mail: pozela@pfi.lt; Požela, K.; Šil?nas, A.; Širmulis, E.; Kašalynas, I.; Jucien?, V.; Venckevi?ius, R. [Center for Physical Sciences and Technology, Semiconductor Physics Institute (Lithuania)

2014-12-15T23:59:59.000Z

10

Size-dependent interface phonon transmission and thermal conductivity of nanolaminates  

E-Print Network [OSTI]

resistance between different materials exists since the interface breaks the regular lattice structure and superlattices as the interface distance or periodic thickness reduces. The interface thermal resistance has beenSize-dependent interface phonon transmission and thermal conductivity of nanolaminates L. H. Liang

Li, Baowen

11

Phonon and thermal properties of exfoliated TaSe2 thin films T. R. Pope,2  

E-Print Network [OSTI]

Phonon and thermal properties of exfoliated TaSe2 thin films Z. Yan,1 C. Jiang,1 T. R. Pope,2 C. F diselenide (2H-TaSe2) obtained via the "graphene-like" mechanical exfoliation of crystals grown by chemical films exfoliated from TaSe2 and other metal dichalcogenides, as well as for evaluating self

12

Ballistic Phonon Thermal Transport in Multiwalled Carbon Nanotubes H.-Y. Chiu,1  

E-Print Network [OSTI]

coupled with the electrical stress of carrying 1012 A=m2 . We also demonstrate a current-driven self-heating can readily conduct heat by ballistic phonon propagation. We determine the thermal conductance quantum of a carbon nano- tube attached to an atomic force microscope (AFM) tip has been observed to be independent

Bockrath, Marc

13

Phononic crystal devices  

DOE Patents [OSTI]

Phononic crystals that have the ability to modify and control the thermal black body phonon distribution and the phonon component of heat transport in a solid. In particular, the thermal conductivity and heat capacity can be modified by altering the phonon density of states in a phononic crystal. The present invention is directed to phononic crystal devices and materials such as radio frequency (RF) tags powered from ambient heat, dielectrics with extremely low thermal conductivity, thermoelectric materials with a higher ratio of electrical-to-thermal conductivity, materials with phononically engineered heat capacity, phononic crystal waveguides that enable accelerated cooling, and a variety of low temperature application devices.

El-Kady, Ihab F. (Albuquerque, NM); Olsson, Roy H. (Albuquerque, NM)

2012-01-10T23:59:59.000Z

14

Phonon-hopping thermal conduction in quantum dot superlattices Manu Shamsa, Weili Liu, and Alexander A. Balandina  

E-Print Network [OSTI]

or polycrystalline materials in terms of thermal transport. © 2005 American Institute of Physics. DOI: 10 strongly depends on interface conditions, is considered as a major thermal resistive mecha- nismPhonon-hopping thermal conduction in quantum dot superlattices Manu Shamsa, Weili Liu

15

Lighting system with thermal management system  

DOE Patents [OSTI]

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

Arik, Mehmet; Weaver, Stanton; Stecher, Thomas; Seeley, Charles; Kuenzler, Glenn; Wolfe, Jr., Charles; Utturkar, Yogen; Sharma, Rajdeep; Prabhakaran, Satish; Icoz, Tunc

2013-05-07T23:59:59.000Z

16

Thermal pumping of light-emitting diodes  

E-Print Network [OSTI]

The work presented here is a study of thermally enhanced injection in light-emitting diodes (LEDs). This effect, which we refer to as "thermal pumping", results from Peltier energy exchange from the lattice to charge ...

Gray, Dodd (Dodd J.)

2011-01-01T23:59:59.000Z

17

Phonon-assisted transient electroluminescence in Si  

SciTech Connect (OSTI)

The phonon-replica infrared emission is observed at room temperature from indirect band gap Si light-emitting diode under forward bias. With increasing injection current density, the broadened electroluminescence spectrum and band gap reduction are observed due to joule heating. The spectral-resolved temporal response of electroluminescence reveals the competitiveness between single (TO) and dual (TO?+?TA) phonon-assisted indirect band gap transitions. As compared to infrared emission with TO phonon-replica, the retarder of radiative recombination at long wavelength region (?1.2??m) indicates lower transition probability of dual phonon-replica before thermal equivalent.

Cheng, Tzu-Huan, E-mail: f94943139@ntu.edu.tw [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan (China); Chu-Su, Yu [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan and Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Liu, Chien-Sheng [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan (China); Lin, Chii-Wann [Institute of Biomedical Engineering and Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China)

2014-06-30T23:59:59.000Z

18

Nonlinear vs. bolometric radiation response and phonon thermal conductance in graphene-superconductor junctions  

SciTech Connect (OSTI)

Graphene is a promising candidate for building fast and ultra-sensitive bolometric detectors due to its weak electron-phonon coupling and low heat capacity. In order to realize a practical graphene-based bolometer, several important issues, including the nature of radiation response, coupling efficiency to the radiation and the thermal conductance need to be carefully studied. Addressing these issues, we present graphene-superconductor junctions as a viable option to achieve efficient and sensitive bolometers, with the superconductor contacts serving as hot electron barriers. For a graphene-superconductor device with highly transparent interfaces, the resistance readout in the presence of radio frequency radiation is dominated by non-linear response. On the other hand, a graphene-superconductor tunnel device shows dominantly bolometric response to radiation. For graphene devices fabricated on SiO{sub 2} substrates, we confirm recent theoretical predictions of T{sup 2} temperature dependence of phonon thermal conductance in the presence of disorder in the graphene channel at low temperatures.

Vora, Heli; Nielsen, Bent; Du, Xu [Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York (United States)

2014-02-21T23:59:59.000Z

19

Effect of phonon confinement on lattice thermal conductivity of lead Telluride quantum well structure  

SciTech Connect (OSTI)

The paper examines the effect of spatial confinement of acoustic phonons on average group velocity and consequently the lattice thermal conductivity of a free-standing PbTe quantum well structure and their temperature dependence. The average group velocity at 100 Å decreases 30% to the bulk value and falls more rapidly on reducing the width of quantum well. Moreover, the lattice thermal conductivity of 100 Å wide PbTe quantum well with value of 0.60 W/mK shows considerable decrease of 70% compared to it’s bulk value. It is observed that the effect of reduction in well width is less pronounce as temperature increases. This appears mainly due to dominance of umklapp processes over the confinement effects.

Tripathi, Madhvendra Nath, E-mail: ommadhav27@gmail.com [Department of Pure and Applied Physics, Guru Ghasidas Vishwavidyalaya, Bilaspur-495009, Chhattisgarh (India)

2014-04-24T23:59:59.000Z

20

Thermoelectric HVAC and Thermal Comfort Enablers for Light-Duty...  

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

Thermoelectric HVAC and Thermal Comfort Enablers for Light-Duty Vehicle Applications Thermoelectric HVAC and Thermal Comfort Enablers for Light-Duty Vehicle Applications 2012 DOE...

Note: This page contains sample records for the topic "lighting phonons thermal" 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

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

SciTech Connect (OSTI)

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

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

2009-03-15T23:59:59.000Z

22

ResearchArticle BuildingThermal,Lighting,  

E-Print Network [OSTI]

ResearchArticle BuildingThermal,Lighting, andAcousticsModeling E-mail: yanda@tsinghua.edu.cn A detailed loads comparison of three building energy modeling programs: EnergyPlus, DeST and DOE-2.1E Dandan and partitions. This comparison study did not produce another test suite, but rather a methodology to design

23

Phonon manipulation with phononic crystals.  

SciTech Connect (OSTI)

In this work, we demonstrated engineered modification of propagation of thermal phonons, i.e. at THz frequencies, using phononic crystals. This work combined theoretical work at Sandia National Laboratories, the University of New Mexico, the University of Colorado Boulder, and Carnegie Mellon University; the MESA fabrication facilities at Sandia; and the microfabrication facilities at UNM to produce world-leading control of phonon propagation in silicon at frequencies up to 3 THz. These efforts culminated in a dramatic reduction in the thermal conductivity of silicon using phononic crystals by a factor of almost 30 as compared with the bulk value, and about 6 as compared with an unpatterned slab of the same thickness. This work represents a revolutionary advance in the engineering of thermoelectric materials for optimal, high-ZT performance. We have demonstrated the significant reduction of the thermal conductivity of silicon using phononic crystal structuring using MEMS-compatible fabrication techniques and in a planar platform that is amenable to integration with typical microelectronic systems. The measured reduction in thermal conductivity as compared to bulk silicon was about a factor of 20 in the cross-plane direction [26], and a factor of 6 in the in-plane direction. Since the electrical conductivity was only reduced by a corresponding factor of about 3 due to the removal of conductive material (i.e., porosity), and the Seebeck coefficient should remain constant as an intrinsic material property, this corresponds to an effective enhancement in ZT by a factor of 2. Given the number of papers in literature devoted to only a small, incremental change in ZT, the ability to boost the ZT of a material by a factor of 2 simply by reducing thermal conductivity is groundbreaking. The results in this work were obtained using silicon, a material that has benefitted from enormous interest in the microelectronics industry and that has a fairly large thermoelectric power factor. In addition, the techniques and scientific understanding developed in the research can be applied to a wide range of materials, with the caveat that the thermal conductivity of such a material be dominated by phonon, rather than electron, transport. In particular, this includes several thermoelectric materials with attractive properties at elevated temperatures (i.e., greater than room temperature), such as silicon germanium and silicon carbide. It is reasonable that phononic crystal patterning could be used for high-temperature thermoelectric devices using such materials, with applications in energy scavenging via waste-heat recovery and thermoelectric cooling for high-performance microelectronic circuits. The only part of the ZT picture missing in this work was the experimental measurement of the Seebeck coefficient of our phononic crystal devices. While a first-order approximation indicates that the Seebeck coefficient should not change significantly from that of bulk silicon, we were not able to actually verify this assumption within the timeframe of the project. Additionally, with regards to future high-temperature applications of this technology, we plan to measure the thermal conductivity reduction factor of our phononic crystals as elevated temperatures to confirm that it does not diminish, given that the nominal thermal conductivity of most semiconductors, including silicon, decreases with temperature above room temperature. We hope to have the opportunity to address these concerns and further advance the state-of-the-art of thermoelectric materials in future projects.

Kim Bongsang; Hopkins, Patrick Edward; Leseman, Zayd C.; Goettler, Drew F.; Su, Mehmet F. (University of New Mexico, Albuquerque, NM); El-Kady, Ihab Fathy; Reinke, Charles M.; Olsson, Roy H., III

2012-01-01T23:59:59.000Z

24

Thermal-neutron capture in light nuclei  

SciTech Connect (OSTI)

We have made considerable progress toward the goal of carrying out thermal-neutron capture {gamma}-ray measurements on all stable isotopes below A=60. Information processed till now has significantly augmented the existing knowledge on the detailed nuclear level structure of many light nuclides. Most of this knowledge comes from our {gamma}-ray energies, level placements, and branching ratios of secondary transitions between low-lying states. Spectroscopic information is also contained in the cross sections of the primary transitions originating from the capturing state. This is deduced from the success of ``direct`` theories of neutron capture for many nuclides, especially those of light and near closed-shell character. 23 refs, 1 tab, 3 figs.

Raman, S. [Oak Ridge National Lab., TN (United States); Jurney, E.T.; Lynn, J.E. [Los Alamos National Lab., NM (United States)

1996-10-01T23:59:59.000Z

25

Phonon wave-packet simulations of Ar/Kr interfaces for thermal rectification  

E-Print Network [OSTI]

by designing them to have extremely low thermal conductivities in the one direction.4 Thermally rectifying extremely difficult. Materials that exhibit thermal rectification would drastically improve our ability and dissimilar materials which have shown thermal rectify- ing behavior. In 2002, Terraneo et al.6 demonstrated

Walker, D. Greg

26

Phonon-Polaritons enhance near field thermal transfer across the phase transition of VO2  

E-Print Network [OSTI]

conductivity contrasts of larger than an order of magnitude exist for switchable materials. Yet the control or very low temperatures. A first effort of rectification of thermal transfer in near field by 40 shown that whereas thermal conductivity and far field heat transfer are difficult to tune, in near field

Paris-Sud XI, Université de

27

Optical characterization of complex mechanical and thermal transport properties  

E-Print Network [OSTI]

Time-resolved impulsive stimulated light scattering (ISS), also known as transient grating spectroscopy, was used to investigate phonon mediated thermal transport in semiconductors and mechanical degrees of freedom linked ...

Johnson, Jeremy A. (Jeremy Andrew)

2011-01-01T23:59:59.000Z

28

Experimental nonclassicality of single-photon-added thermal light states  

SciTech Connect (OSTI)

We report the experimental realization and tomographic analysis of quantum light states obtained by exciting a classical thermal field by a single photon. Such states, although completely incoherent, possess a tunable degree of quantumness which is here exploited to put to a stringent experimental test some of the criteria proposed for the proof and the measurement of state nonclassicality. The quantum character of the states is also given in quantum information terms by evaluating the amount of entanglement that they can produce.

Zavatta, Alessandro [Istituto Nazionale di Ottica Applicata (CNR), L.go E. Fermi, 6, I-50125, Florence (Italy); Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Parigi, Valentina [Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); LENS, Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence (Italy); Bellini, Marco [Istituto Nazionale di Ottica Applicata (CNR), L.go E. Fermi, 6, I-50125, Florence (Italy); LENS, Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence (Italy)

2007-05-15T23:59:59.000Z

29

Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors  

E-Print Network [OSTI]

Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors developed for the optimization of light-emitting diodes (LED) and solar thermal collectors. The surface a light-extraction efficiency of only 3.7%). The solar thermal collector we considered consists

Mayer, Alexandre

30

Wide-Area Thermal Processing of Light-Emitting Materials  

SciTech Connect (OSTI)

Silicon carbide based materials and devices have been successfully exploited for diverse electronic applications. However, they have not achieved the same success as Si technologies due to higher material cost and higher processing temperatures required for device development. Traditionally, SiC is not considered for optoelectronic applications because it has an indirect bandgap. However, AppliCote Associates, LLC has developed a laser-based doping process which enables light emission in SiC through the creation of embedded p-n junctions. AppliCote laser irradiation of silicon carbide allows two different interaction mechanisms: (1) Laser conversion or induced phase transformation which creates carbon rich regions that have conductive properties. These conductive regions are required for interconnection to the light emitting semiconducting region. (2) Laser doping which injects external dopant atoms into the substrate that introduces deep level transition states that emit light when electrically excited. The current collaboration with AppliCote has focused on the evaluation of ORNL's unique Pulse Thermal Processing (PTP) technique as a replacement for laser processing. Compared to laser processing, Pulse Thermal Processing can deliver similar energy intensities (20-50 kW/cm2) over a much larger area (up to 1,000 cm2) at a lower cost and much higher throughput. The main findings of our investigation; which are significant for the realization of SiC based optoelectronic devices, are as follows: (1) The PTP technique is effective in low thermal budget activation of dopants in SiC similar to the laser technique. The surface electrical conductivity of the SiC samples improved by about three orders of magnitude as a result of PTP processing which is significant for charge injection in the devices; (2) The surface composition of the SiC film can be modified by the PTP technique to create a carbon-rich surface (increased local C:Si ratio from 1:1 to 2.9:1). This is significant as higher thermal and electrical conductivities of the surface layer are critical for a successful development of integrated optoelectronic devices; and (3) PTP provides low thermal budget dopant activation with a controlled depth profile, which can be exploited for high performance device development with selective patterning of the substrate. This project has successfully demonstrated that a low thermal budget annealing technique, such as PTP, is critical to defining the path for low cost electronic devices integrated on glass or polymeric substrates. This project is complimentary to the goals of the Solid State Lighting Program within DOE. It involves new manufacturing techniques for light emitting materials that are potentially much lower cost and energy efficient than existing products. Significant opportunity exists for further exploration of AppliCote's material and device technology in combination with ORNL's PTP technique, modeling, and characterization capabilities.

Duty, C.; Quick, N. (AppliCote Associates, LLC) [AppliCote Associates, LLC

2011-09-30T23:59:59.000Z

31

Lighting system with thermal management system having point contact synthetic jets  

DOE Patents [OSTI]

Lighting system having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system includes a plurality of synthetic jets. The synthetic jets are arranged within the lighting system such that they are secured at contact points.

Arik, Mehmet; Weaver, Stanton Earl; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Sharma, Rajdeep

2013-12-10T23:59:59.000Z

32

Nonequilibrium phonon effects in midinfrared quantum cascade lasers  

SciTech Connect (OSTI)

We investigate the effects of nonequilibrium phonon dynamics on the operation of a GaAs-based midinfrared quantum cascade laser over a range of temperatures (77–300?K) via a coupled ensemble Monte Carlo simulation of electron and optical-phonon systems. Nonequilibrium phonon effects are shown to be important below 200?K. At low temperatures, nonequilibrium phonons enhance injection selectivity and efficiency by drastically increasing the rate of interstage electron scattering from the lowest injector state to the next-stage upper lasing level via optical-phonon absorption. As a result, the current density and modal gain at a given field are higher and the threshold current density lower and considerably closer to experiment than results obtained with thermal phonons. By amplifying phonon absorption, nonequilibrium phonons also hinder electron energy relaxation and lead to elevated electronic temperatures.

Shi, Y. B., E-mail: yshi9@wisc.edu; Knezevic, I., E-mail: knezevic@engr.wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706-1691 (United States)

2014-09-28T23:59:59.000Z

33

Detecting phonon blockade with photons  

SciTech Connect (OSTI)

Measuring the quantum dynamics of a mechanical system, when few phonons are involved, remains a challenge. We show that a superconducting microwave resonator linearly coupled to the mechanical mode constitutes a very powerful probe for this scope. This new coupling can be much stronger than the usual radiation pressure interaction by adjusting a gate voltage. We focus on the detection of phonon blockade, showing that it can be observed by measuring the statistics of the light in the cavity. The underlying reason is the formation of an entangled state between the two resonators. Our scheme realizes a phonotonic Josephson junction, giving rise to coherent oscillations between phonons and photons as well as a self-trapping regime for a coupling smaller than a critical value. The transition from the self-trapping to the oscillating regime is also induced dynamically by dissipation.

Didier, Nicolas; Pugnetti, Stefano; Fazio, Rosario [NEST, Scuola Normale Superiore and Istituto di Nanoscienze - CNR, Pisa (Italy); Blanter, Yaroslav M. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

2011-08-01T23:59:59.000Z

34

Thermal and lighting performance of toplighting systems in the hot and humid climate of Thailand  

E-Print Network [OSTI]

performance of three toplighting systems were compared. For the thermal performance, total cooling loads, heat gains and losses, and interior temperature were evaluated. The lighting performance parameters examined were daylight factor, illuminance level...

Harntaweewongsa, Siritip

2006-10-30T23:59:59.000Z

35

Strong enhancement of light absorption and highly directive thermal emission in graphene  

E-Print Network [OSTI]

Strong enhancement of light absorption and highly directive thermal emission in graphene Mingbo Pu: Graphene is a two-dimensional material with exotic electronic, optical and thermal properties. The optical absorption in monolayer graphene is limited by the fine structure constant . Here we demonstrated the strong

Chen, Po

36

Waverly Light and Power- Residential Solar Thermal Rebates  

Broader source: Energy.gov [DOE]

Waverly Light and Power (WL&P) offers rebates for solar hot water heating systems to its residential customers. All purchases must be pre-approved through WL&P's solar water heater...

37

Optical and mechanical mode tuning in an optomechanical crystal with light-induced thermal effects  

SciTech Connect (OSTI)

We report on the modification of the optical and mechanical properties of a silicon 1D optomechanical crystal cavity due to thermo-optic effects in a high phonon/photon population regime. The cavity heats up due to light absorption in a way that shifts the optical modes towards longer wavelengths and the mechanical modes to lower frequencies. By combining the experimental optical results with finite-difference time-domain simulations, we establish a direct relation between the observed wavelength drift and the actual effective temperature increase of the cavity. By assuming that the Young's modulus decreases accordingly to the temperature increase, we find a good agreement between the mechanical mode drift predicted using a finite element method and the experimental one.

Navarro-Urrios, D., E-mail: daniel.navarrourrios@nano.cnr.it [Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Edifici ICN2, 08193 Bellaterra (Spain); NEST, Istituto Nanoscienze–CNR and Scuola Normale Superiore, Piazza San Silvestro 12, Pisa I-56127 (Italy); Gomis-Bresco, J.; Alzina, F. [Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Edifici ICN2, 08193 Bellaterra (Spain); Capuj, N. E. [Depto. Física, Universidad de la Laguna, 38206 La Laguna (Spain); Griol, A.; Puerto, D.; Martínez, A. [Nanophotonics Technology Center, Universitat Politècnica de València, Valencia (Spain); Sotomayor-Torres, C. M. [Catalan Institute of Nanoscience and Nanotechnology, Campus UAB, Edifici ICN2, 08193 Bellaterra (Spain); Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona (Spain)

2014-09-07T23:59:59.000Z

38

Thermal And Mechanical Analysis of High-power Light-emitting Diodes with Ceramic Packages  

E-Print Network [OSTI]

In this paper we present the thermal and mechanical analysis of high-power light-emitting diodes (LEDs) with ceramic packages. Transient thermal measurements and thermo-mechanical simulation were performed to study the thermal and mechanical characteristics of ceramic packages. Thermal resistance from the junction to the ambient was decreased from 76.1 oC/W to 45.3 oC/W by replacing plastic mould to ceramic mould for LED packages. Higher level of thermo-mechanical stresses in the chip were found for LEDs with ceramic packages despite of less mismatching coefficients of thermal expansion comparing with plastic packages. The results suggest that the thermal performance of LEDs can be improved by using ceramic packages, but the mounting process of the high power LEDs with ceramic packages is critically important and should be in charge of delaminating interface layers in the packages.

J. Hu; L. Yang; M. -W. Shin

2008-01-07T23:59:59.000Z

39

Synthetic thermoelectric materials comprising phononic crystals  

DOE Patents [OSTI]

Synthetic thermoelectric materials comprising phononic crystals can simultaneously have a large Seebeck coefficient, high electrical conductivity, and low thermal conductivity. Such synthetic thermoelectric materials can enable improved thermoelectric devices, such as thermoelectric generators and coolers, with improved performance. Such synthetic thermoelectric materials and devices can be fabricated using techniques that are compatible with standard microelectronics.

El-Kady, Ihab F; Olsson, Roy H; Hopkins, Patrick; Reinke, Charles; Kim, Bongsang

2013-08-13T23:59:59.000Z

40

Belgirate, Italy, 28-30 September 2005 MECHANISM AND THERMAL EFFECT OF DELAMINATION IN LIGHT-EMITTING  

E-Print Network [OSTI]

for the investigation of the thermal behavior of the delaminated LEDs. Increase of thermal resistance with the degreeBelgirate, Italy, 28-30 September 2005 MECHANISM AND THERMAL EFFECT OF DELAMINATION IN LIGHT-EMITTING DIODE PACKAGES Jianzheng Hu, Lianqiao Yang, and Moo Whan Shin Department of Materials Science

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Hypersonic phononic crystals  

E-Print Network [OSTI]

Manipulation of the distribution of phonons inM a solid is important for both basic science and applications ranging from heat management to reduction of noise in electronic circuits and creating materials with superior ...

Gorishnyy, Taras

2007-01-01T23:59:59.000Z

42

PHONONS IN INTRINSIC JOSEPHSON SYSTEMS  

SciTech Connect (OSTI)

Subgap structures in the I-V curves of layered superconductors are explained by the excitation of phonons by Josephson oscillations. In the presence of a magnetic field applied parallel to the layers additional structures due to fluxon motion appear. Their coupling with phonons is investigated theoretically and a shift of the phonon resonances in strong magnetic fields is predicted.

C. PREIS; K. SCHMALZL; ET AL

2000-10-01T23:59:59.000Z

43

ISSN:1369 7021 Elsevier Ltd 2012JUNE 2012 | VOLUME 15 | NUMBER 6266 Phononics in  

E-Print Network [OSTI]

dispersion, which can be written as = VSq, where VS is the sound velocity, while the optical phonons crystals. Phonons ­ quanta of crystal lattice vibrations ­ reveal themselves in all electrical, thermal-plane orientation. Alexander A. Balandina,* and Denis L. Nikaa,b aDepartment of Electrical Engineering and Materials

44

Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin Temperatures I. V. Borzenets,1  

E-Print Network [OSTI]

Phonon Bottleneck in Graphene-Based Josephson Junctions at Millikelvin Temperatures I. V. Borzenets and superconducting branches in superconductor-graphene-superconductor Josephson junctions. We attribute thermalization by phonons at low temperatures (T & 1 K). The relationship between the applied power

Finkelstein, Gleb

45

Thermal performance of typical light frame walls with reflective surface insulations  

SciTech Connect (OSTI)

A series of tests were conducted in a guarded hotbox to evaluate the thermal performance (R-value) of wall constructions typical of light-frame buildings that are commonly used in agricultural applications. The systems were insulated with either a commercially available foil-faced bubble pack material (FFBP) or foil-faced polyisocyanurate (PIR) foam board. Tests were conducted under two different temperature conditions, chosen to be representative of a midwestern winter and summer. This paper reports temperatures of the surfaces bounding the reflective airspaces measured and the R-value calculated. These data were used in the ASHRAE series/parallel calculations and the resultant R-value was compared to the measured R-value. Agreement was usually better than 10%.

Miller, R.G. (Jim Walter Research Corp., St. Petersburg, FL (US)); Riskowski, G.L.; Christianson, L.L. (Agricultural Engineering Dept., Univ. of Illinois at Urbana-Champaign, IL (US))

1989-01-01T23:59:59.000Z

46

Hanbury Brown-Twiss effect and thermal light ghost imaging: A unified approach  

E-Print Network [OSTI]

. Wu, and X. H. Chen, Opt. Lett. 30, 2354 #1;2005#2;. #3;12#4; D. Z. Cao, J. Xiong, and K. Wang, Phys. Rev. A 71, 013801 #1;2005#2;; M. D?Angelo, A. Valencia, M. H. Rubin and Y. Shih, ibid. 72, 013810 #1;2005#2;; K. Wang and D. Z. Cao, ibid. 70... direction #1;one dimension#2;. This however does not affect the physics. For the thermal light at the source, the first-order correla- tion can be written as a series of the form #3;15,16#4;, #5;Es+#1;x1#2;Es#1;x2#2;#6; #6; 1 ? #7;#1;x1 ? x2#2;2 + #8...

Wang, Li-Gang; Qamar, Sajid; Zhu, Shi-Yao; Zubairy, M. Suhail

2009-01-01T23:59:59.000Z

47

Phonon dispersion in graphene  

E-Print Network [OSTI]

Taking into account the constraints imposed by the lattice symmetry, the phonon dispersion is calculated for graphene with interactions between the first and second nearest neighbors in the framework of the Born-von Karman model. Analytical expressions are obtained for the out-of-plane (bending) modes determined only by two force constants as well as for the in-plane modes with four force constants. Values of the force constants are found in fitting to elastic constants and Raman frequencies observed in graphite.

L. A. Falkovsky

2007-08-11T23:59:59.000Z

48

Mineralogy of the light-toned outcrop at Meridiani Planum as seen by the Miniature Thermal Emission Spectrometer and implications  

E-Print Network [OSTI]

Mineralogy of the light-toned outcrop at Meridiani Planum as seen by the Miniature Thermal Emission a spectral library used to determine the mineralogy of the outcrop from this spectral shape. Linear mineralogy to chemistry shows good agreement with the chemical composition of the outcrops determined by APXS

Glotch, Timothy D.

49

Phonons and vibrons as markers of the  

E-Print Network [OSTI]

temperature In conjugated polimers and nanotubes phonon sidebands are observed poly(p-phenylene vinylene) PRL

Marini, Andrea

50

Demand Shifting with Thermal Mass in Light and Heavy Mass Commercial Buildings  

SciTech Connect (OSTI)

The potential for utilizing building thermal mass for load shifting and peak demand reduction has been demonstrated in a number of simulation, laboratory, and field studies. This project studied the potential of pre-cooling and demand limiting in a heavy mass and a light mass building in the Bay Area of California. The conclusion of the work to date is that pre-cooling has the potential to improve the demand responsiveness of commercial buildings while maintaining acceptable comfort conditions. Results indicate that pre-cooling increases the depth (kW) and duration (kWh) of the shed capacity of a given building, all other factors being equal. Due to the time necessary for pre-cooling, it is only applicable to day-ahead demand response programs. Pre-cooling can be very effective if the building mass is relatively heavy. The effectiveness of night pre-cooling under hot weather conditions has not been tested. Further work is required to quantify and demonstrate the effectiveness of pre-cooling in different climates. Research is also needed to develop screening tools that can be used to select suitable buildings and customers, identify the most appropriate pre-cooling strategies, and estimate the benefits to the customer and the utility.

Xu, Peng; Zagreus, Leah

2009-05-01T23:59:59.000Z

51

Calculation of Confined Phonon Spectrum in Narrow Silicon Nanowires using the Valence Force Field Method  

E-Print Network [OSTI]

that the thermal conductivity in such materials can be drastically reduced compared to bulk Si. Values as low conductance and boundary scattering- limited diffusive thermal conductivity. We find that the phononic dispersion and the ballistic thermal conductance are functions of the geometrical features of the structures

52

Structure of crystalline oxide ceramics studied by phonon spectroscopy  

SciTech Connect (OSTI)

This paper describes a method for gaining detailed insight into the structure and phonon spectrum of polycrystalline oxide ceramics. We examine how the diffusion coefficient of subterahertz phonons is related to the properties of a system of grain boundaries and to the grain size and structure and demonstrate that the temperature dependence of the phonon diffusion coefficient at liquid-helium temperatures is determined by the spectral properties of the intergranular layer, which allows one to estimate the volumeaveraged intergranular layer thickness and acoustic impedance. We also analyse the effect of plastic deformation via twinning on the formation of the structure of grains and intergranular layers, which determine the thermophysical, acoustic and optical properties of ceramic materials. (extreme light fields and their applications)

Kaminskii, Alexandr A; Taranov, A V; Khazanov, E N

2013-03-31T23:59:59.000Z

53

Thermal conductivity of the quark matter for the SU(2) light-flavor sector  

E-Print Network [OSTI]

We investigate the thermal conductivity ($\\kappa$) of the quark matter at finite quark chemical potential $(\\mu)$ and temperature $(T)$, employing the Green-Kubo formula, for the SU(2) light-flavor sector with the finite current-quark mass $m=5$ MeV. As a theoretical framework, we construct an effective thermodynamic potential from the $(\\mu,T)$-modified liquid-instanton model (mLIM). Note that all the relevant model parameters are designated as functions of $T$, using the trivial-holonomy caloron solution. By solving the self-consistent equation of mLIM, we acquire the constituent-quark mass $M_0$ as a function of $T$ and $\\mu$, satisfying the universal-class patterns of the chiral phase transition. From the numerical results for $\\kappa$, we observe that there emerges a peak at $\\mu\\approx200$ MeV for the low-$T$ region, i.e. $T\\lesssim100$ MeV. As $T$ increase over $T\\approx100$ MeV, the curve for $\\kappa$ is almost saturated as a function of $T$ in the order of $\\sim10^{-1}\\,\\mathrm{GeV}^2$, and grows with respect to $\\mu$ smoothly. At the normal nuclear-matter density $\\rho_0=0.17\\,\\mathrm{fm}^{-3}$, $\\kappa$ shows its maximum $6.22\\,\\mathrm{GeV}^2$ at $T\\approx10$ MeV, then decreases exponentially down to $\\kappa\\approx0.2\\,\\mathrm{GeV}^2$. We also compute the ratio of $\\kappa$ and the entropy density, i.e. $\\kappa/s$ as a function of $(\\mu,T)$ which is a monotonically decreasing function for a wide range of $T$, then approaches a lower bound at very high $T$: $\\kappa/s_\\mathrm{min}\\gtrsim0.3\\,\\mathrm{GeV}^{-1}$ in the vicinity of $\\mu=0$.

Seung-il Nam

2015-03-04T23:59:59.000Z

54

Thermal conductivity of bulk nanostructured lead telluride  

SciTech Connect (OSTI)

Thermal conductivity of lead telluride with embedded nanoinclusions was studied using Monte Carlo simulations with intrinsic phonon transport properties obtained from first-principles-based lattice dynamics. The nanoinclusion/matrix interfaces were set to completely reflect phonons to model the maximum interface-phonon-scattering scenario. The simulations with the geometrical cross section and volume fraction of the nanoinclusions matched to those of the experiment show that the experiment has already reached the theoretical limit of thermal conductivity. The frequency-dependent analysis further identifies that the thermal conductivity reduction is dominantly attributed to scattering of low frequency phonons and demonstrates mutual adaptability of nanostructuring and local disordering.

Hori, Takuma [Department of Mechanical Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8656 (Japan); Chen, Gang [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Shiomi, Junichiro, E-mail: shiomi@photon.t.u-tokyo.ac.jp [Department of Mechanical Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8656 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan)

2014-01-13T23:59:59.000Z

55

Thermal Issues Associated with the Lighting Systems, Electronics Racks, and Pre-Amplifier Modules in the National Ignition System  

SciTech Connect (OSTI)

This report summarizes an investigation of the thermal issues related to the National Ignition Facility. The influence of heat sources such as lighting fixtures, electronics racks, and pre-amplifier modules (PAMs) on the operational performance of the laser guide beam tubes and optical alignment hardware in the NE laser bays were investigated with experiments and numerical models. In particular, empirical heat transfer data was used to establish representative and meaningful boundary conditions and also serve as bench marks for computational fluid dynamics (CFD) models. Numerical models, constructed with a commercial CFD code, were developed to investigate the extent of thermal plumes and radiation heat transfer from the heat sources. From these studies, several design modifications were recommended including reducing the size of all fluorescent lights in the NIF laser bays to single 32 W bulb fixtures, maintaining minimum separation distances between light fixtures/electronics racks and beam transport hardware, adding motion sensors in areas of the laser bay to control light fixture operation during maintenance procedures, properly cooling all electronics racks with air-water heat exchangers with heat losses greater than 25 W/rack to the M1 laser bay, ensuring that the electronics racks are not overcooked and thus maintain their surface temperatures to within a few degrees centigrade of the mean air temperature, and insulating the electronic bays and optical support structures on the PAMs.

A. C. Owen; J. D. Bernardin; K. L. Lam

1998-08-01T23:59:59.000Z

56

Rate of decoherence for an electron weakly coupled to a phonon gas  

E-Print Network [OSTI]

We study the dynamics of an electron weakly coupled to a phonon gas. The initial state of the electron is the superposition of two spatially localized distant bumps moving towards each other, and the phonons are in a thermal state. We investigate the dynamics of the system in the kinetic regime and show that the time evolution makes the non-diagonal terms of the density matrix of the electron decay, destroying the interference between the two bumps. We show that such a damping effect is exponential in time, and the related decay rate is proportional to the total scattering cross section of the electron-phonon interaction.

Riccardo Adami; Laszlo Erdos

2008-02-08T23:59:59.000Z

57

Direct evaluation of ballistic phonon transport in a multi-walled carbon nanotube  

SciTech Connect (OSTI)

Phonon confinement and in situ thermal conductance measurements in an individual multi-walled carbon nanotube (MWNT) are reported. Focused ion beam (FIB) irradiation was used to successively shorten a 4.8??m long MWNT, eventually yielding a 0.3??m long MWNT. After the first FIB irradiation, a 41% reduction in conductance was achieved, compared with that of the pristine MWNT. This was because the contributions from phonons with long free paths were excluded by scattering at FIB-induced defects. Phonon transport in linked multiple-length nanotubes was also investigated.

Hayashi, Hiroyuki [Department of Aeronautics and Astronautics, Kyushu University, Fukuoka 819-0395 (Japan); Takahashi, Koji, E-mail: takahashi@aero.kyushu-u.ac.jp [Department of Aeronautics and Astronautics, Kyushu University, Fukuoka 819-0395 (Japan); JST, CREST, Kyushu University, Fukuoka 819-0395 (Japan); International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Ikuta, Tatsuya; Nishiyama, Takashi [Department of Aeronautics and Astronautics, Kyushu University, Fukuoka 819-0395 (Japan); JST, CREST, Kyushu University, Fukuoka 819-0395 (Japan); Takata, Yasuyuki [JST, CREST, Kyushu University, Fukuoka 819-0395 (Japan); International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Zhang, Xing [International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China)

2014-03-17T23:59:59.000Z

58

An informatics based analysis of the impact of isotope substitution on phonon modes in graphene  

SciTech Connect (OSTI)

It is shown by informatics that the high frequency short ranged modes exert a significant influence in impeding thermal transport through isotope substituted graphene nanoribbons. Using eigenvalue decomposition methods, we have extracted features in the phonon density of states spectra that reveal correlations between isotope substitution and phonon modes. This study also provides a data driven computational framework for the linking of materials chemistry and transport properties in 2D systems.

Broderick, Scott; Srinivasan, Srikant; Rajan, Krishna [Department of Material Science and Engineering, Iowa State University, Ames, Iowa 50011 (United States); Ray, Upamanyu; Balasubramanian, Ganesh, E-mail: bganesh@iastate.edu [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2014-06-16T23:59:59.000Z

59

Microsecond switchable thermal antenna  

SciTech Connect (OSTI)

We propose a thermal antenna that can be actively switched on and off at the microsecond scale by means of a phase transition of a metal-insulator material, the vanadium dioxide (VO{sub 2}). This thermal source is made of a periodically patterned tunable VO{sub 2} nanolayer, which support a surface phonon-polariton in the infrared range in their crystalline phase. Using electrodes properly registered with respect to the pattern, the VO{sub 2} phase transition can be locally triggered by ohmic heating so that the surface phonon-polariton can be diffracted by the induced grating, producing a highly directional thermal emission. Conversely, when heating less, the VO{sub 2} layers cool down below the transition temperature, the surface phonon-polariton cannot be diffracted anymore so that thermal emission is inhibited. This switchable antenna could find broad applications in the domain of active thermal coatings or in those of infrared spectroscopy and sensing.

Ben-Abdallah, Philippe, E-mail: pba@institutoptique.fr; Benisty, Henri; Besbes, Mondher [Laboratoire Charles Fabry, UMR 8501, Institut d'Optique, CNRS, Université Paris-Sud 11, 2, Avenue Augustin Fresnel, 91127 Palaiseau Cedex (France)

2014-07-21T23:59:59.000Z

60

Unconventional plasmon-phonon coupling in graphene  

E-Print Network [OSTI]

We predict the existence of coupled plasmon-phonon excitations in graphene by using the self-consistent linear response formalism. The unique electron-phonon interaction in graphene leads to unconventional mixing of plasmon ...

Jablan, Marinko

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Neutron Scattering Investigation of Phonon Scattering Rates in Ag1-xSb1+xTe2+x (x = 0, 0.1, and 0.2)  

SciTech Connect (OSTI)

The phonon dispersions and scattering rates of the thermoelectric material AgSbTe$_{2}$ were measured as a function of temperature with inelastic neutron scattering. The results show that phonon scattering rates are large and weakly dependent on temperature. The lattice thermal conductivity was calculated from the measured phonon lifetimes and group velocities, providing good agreement with bulk transport measurements. The measured phonon scattering rates and their temperature dependence are compared with models of phonon scattering by anharmonicity and point defect. We find that these processes cannot account for the large total phonon scattering rates observed, and their lack of temperature dependence. Neutron and synchrotron diffraction measurements on single crystals revealed an extensive nanostructure from cation ordering, which is likely responsible for the strong phonon scattering.

Abernathy, Douglas L [ORNL; Budai, John D [ORNL; Delaire, Olivier A [ORNL; Ehlers, Georg [ORNL; Hong, Tao [ORNL; Karapetrova, Evguenia A. [Argonne National Laboratory (ANL); Ma, Jie [ORNL; May, Andrew F [ORNL; McGuire, Michael A [ORNL; Specht, Eliot D [ORNL

2014-01-01T23:59:59.000Z

62

Phonon-mediated coupling between quantum dots through an off-resonant microcavity  

E-Print Network [OSTI]

We present experimental results showing phonon-mediated coupling between two quantum dots embedded inside a photonic crystal microcavity. With only one of the dots being spectrally close to the cavity, we observe both frequency up-conversion and down-conversion of the pump light via a $\\sim1.2$ THz phonon. We demonstrate this process for both weak and strong regimes of dot-cavity coupling, and provide a simple theoretical model explaining our observations.

Arka Majumdar; Michal Bajcsy; Armand Rundquist; Erik Kim; Jelena Vuckovic

2011-11-30T23:59:59.000Z

63

Demand Shifting with Thermal Mass in Light and Heavy Mass Commercial Buildings  

E-Print Network [OSTI]

as a Demand Response (DR) strategy for commercial buildings.demand response program because the added demand reduction from different buildingsdemand response, thermal mass INTRODUCTION The structural mass within existing commercial buildings

Xu, Peng

2010-01-01T23:59:59.000Z

64

Light stable isotope study of the Roosevelt Hot Springs thermal area, Southwestern Utah  

SciTech Connect (OSTI)

The isotopic composition of hydrogen, oxygen, and carbon has been determined for regional cold springs, thermal fluids, and rocks and minerals from the Roosevelt Hot Springs thermal area. The geothermal system has developed within plutonic granitic rocks and amphibolite facies gneiss, relying upon fracture-controlled permeability for the migration of the thermal fluids. Probably originating as meteoric waters in the upper elevations of the Mineral Mountains, the thermal waters sampled in the production wells display an oxygen isotopic shift of at least +1.2. Depletions of delta /sup 18/O in wole rock, K-feldspar, and biotite have a positive correlation with alteration intensity. W/R mass ratios, calculated from the isotopic shifts of rock and water, range up to 3.0 in a producing horizon of one well, although the K-feldspar has experienced only 30% exchange with the thermal waters. While veinlet quartz has equilibrated with the thermal waters, the /sup 18/O values of K-mica clay, an alteration product of plagioclase, mimic the isotopic composition of K-feldspar and whole rock. This suggests that locally small W/R ratios enable plagioclase to influence its alteration products by isotopic exchange.

Rohrs D.T.; Bowman, J.R.

1980-05-01T23:59:59.000Z

65

Multiscale thermal transport.  

SciTech Connect (OSTI)

A concurrent computational and experimental investigation of thermal transport is performed with the goal of improving understanding of, and predictive capability for, thermal transport in microdevices. The computational component involves Monte Carlo simulation of phonon transport. In these simulations, all acoustic modes are included and their properties are drawn from a realistic dispersion relation. Phonon-phonon and phonon-boundary scattering events are treated independently. A new set of phonon-phonon scattering coefficients are proposed that reflect the elimination of assumptions present in earlier analytical work from the simulation. The experimental component involves steady-state measurement of thermal conductivity on silicon films as thin as 340nm at a range of temperatures. Agreement between the experiment and simulation on single-crystal silicon thin films is excellent, Agreement for polycrystalline films is promising, but significant work remains to be done before predictions can be made confidently. Knowledge gained from these efforts was used to construct improved semiclassical models with the goal of representing microscale effects in existing macroscale codes in a computationally efficient manner.

Graham, Samuel Jr. (; .); Wong, C. C.; Piekos, Edward Stanley

2004-02-01T23:59:59.000Z

66

Full-dispersion Monte Carlo simulation of phonon transport in micron-sized graphene nanoribbons  

SciTech Connect (OSTI)

We simulate phonon transport in suspended graphene nanoribbons (GNRs) with real-space edges and experimentally relevant widths and lengths (from submicron to hundreds of microns). The full-dispersion phonon Monte Carlo simulation technique, which we describe in detail, involves a stochastic solution to the phonon Boltzmann transport equation with the relevant scattering mechanisms (edge, three-phonon, isotope, and grain boundary scattering) while accounting for the dispersion of all three acoustic phonon branches, calculated from the fourth-nearest-neighbor dynamical matrix. We accurately reproduce the results of several experimental measurements on pure and isotopically modified samples [S. Chen et al., ACS Nano 5, 321 (2011);S. Chen et al., Nature Mater. 11, 203 (2012); X. Xu et al., Nat. Commun. 5, 3689 (2014)]. We capture the ballistic-to-diffusive crossover in wide GNRs: room-temperature thermal conductivity increases with increasing length up to roughly 100??m, where it saturates at a value of 5800?W/m K. This finding indicates that most experiments are carried out in the quasiballistic rather than the diffusive regime, and we calculate the diffusive upper-limit thermal conductivities up to 600?K. Furthermore, we demonstrate that calculations with isotropic dispersions overestimate the GNR thermal conductivity. Zigzag GNRs have higher thermal conductivity than same-size armchair GNRs, in agreement with atomistic calculations.

Mei, S., E-mail: smei4@wisc.edu; Knezevic, I., E-mail: knezevic@engr.wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Maurer, L. N. [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Aksamija, Z. [Department of Electrical and Computer Engineering, University of Massachusetts-Amherst, Amherst, Massachusetts 01003 (United States)

2014-10-28T23:59:59.000Z

67

Nanoscale transport of phonons: Dimensionality, subdiffusion, molecular damping, and interference effects  

SciTech Connect (OSTI)

We examine heat transport carried by acoustic phonons in the systems composed of nanoscale chains of masses coupled to two thermal baths of different temperatures. Thermal conductance is obtained by using linearized Landauer-type formula for heat flux with phonon transmission probability calculated within atomistic Green's functions (AGF) method. AGF formalism is extended onto dissipative chains of masses with harmonic coupling beyond nearest-neighbor approximation, while atomistic description of heat reservoirs is also included into computational scheme. In particular, the phonon lifetimes and the phonon frequency shifts are discussed for harmonic lattices of different dimensions. Further, resonant structure of phonon transmission spectrum is analyzed with respect to reservoir-induced effects, molecular damping, and mass-to-mass harmonic coupling. Analysis of transmission zeros (antiresonances) and their accompanied Fano-shape resonances are discussed as a result of interference effects between different vibrational modes. Finally, we also predict subdiffusive transport regime for low-frequency ballistic phonons propagated along a linear chain of harmonically coupled masses.

Walczak, Kamil; Yerkes, Kirk L. [Aerospace Systems Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States)

2014-05-07T23:59:59.000Z

68

The USDOE Forrestal Lighting Retrofit: Analysis of Electricity and Thermal Savings  

E-Print Network [OSTI]

,705 or 76% of the total monetary savings. The measured energy savings performed within 90% of the estimated savings. Quite surprisingly, the thermal savings which were not included in initial estimates by the USDOE accounted for $102,824 or 24...

Haberl, J. S.; Bou-Saada, T. E.

1995-01-01T23:59:59.000Z

69

Determination of the electron–phonon coupling constant in tungsten  

SciTech Connect (OSTI)

We used two methods to determine the effective electron-phonon coupling constant (G{sub 0}) in tungsten. Our first principles calculations predict G{sub 0}?=?1.65?×?10{sup 17?}W m{sup ?3} K{sup ?1}. The temporal decay of the femtosecond-resolution optical reflectivity for a (100) surface of bulk W was measured using a pump-probe scheme and analysed using ab initio parameterised two temperature model, which includes both the effects of the electron-phonon coupling and thermal conduction into bulk. This analysis gives G{sub 0}?=?1.4(3)?×?10{sup 17?}W m{sup ?3} K{sup ?1}, in good agreement with the theoretical prediction. The described effective method of calculating and measuring G{sub 0} in bulk materials can be easily extended to other metals.

Daraszewicz, Szymon L.; Duffy, Dorothy M.; Shluger, Alexander L. [Department of Physics and Astronomy, London Centre for Nanotechnology, University College London, Gower Street, WC1E 6BT London (United Kingdom); Giret, Yvelin [Department of Physics and Astronomy, London Centre for Nanotechnology, University College London, Gower Street, WC1E 6BT London (United Kingdom); The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan); Tanimura, Hiroshi; Tanimura, Katsumi [The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan)

2014-07-14T23:59:59.000Z

70

Quantifying electron-phonon coupling in CdTe12xSex nanocrystals via coherent phonon manipulation  

E-Print Network [OSTI]

Quantifying electron-phonon coupling in CdTe12xSex nanocrystals via coherent phonon manipulation B to manipulate coherent phonon excitation and quantify the strength of electron-phonon coupling in CdTe1Ã?xSex nanocrystals (NCs). Raman active CdSe and CdTe longitudinal optical phonon (LO) modes are excited and probed

Xu, Xianfan

71

Anisotropies in Non-Thermal Distortions of Cosmic Light from Photon-Axion Conversion  

E-Print Network [OSTI]

Ultralight axions which couple sufficiently strongly to photons can leave imprints on the sky at diverse frequencies by mixing with cosmic light in the presence of background magnetic fields. We explore such direction dependent grey-body distortions of the CMB spectrum, enhanced by resonant conditions in the IGM plasma. We also find that if such axions are produced in the early universe and represent a subdominant dark radiation component today, they could convert into X-rays in supervoids, and brighten them at X-ray frequencies.

Guido D'Amico; Nemanja Kaloper

2015-01-07T23:59:59.000Z

72

Anisotropies in Non-Thermal Distortions of Cosmic Light from Photon-Axion Conversion  

E-Print Network [OSTI]

Ultralight axions which couple sufficiently strongly to photons can leave imprints on the sky at diverse frequencies by mixing with cosmic light in the presence of background magnetic fields. We explore such direction dependent grey-body distortions of the CMB spectrum, enhanced by resonant conditions in the IGM plasma. We also find that if such axions are produced in the early universe and represent a subdominant dark radiation component today, they could convert into X-rays in supervoids, and brighten them at X-ray frequencies.

D'Amico, Guido

2015-01-01T23:59:59.000Z

73

Friction as Basis for a Phonon Maser  

E-Print Network [OSTI]

Evidence is provided from experiment, for the hypothesis that defect organization (internal friction) is a means for operation of a phonon maser.

Randall D. Peters

2003-08-08T23:59:59.000Z

74

Light storage via coherent population oscillation in a thermal cesium vapor  

E-Print Network [OSTI]

We report on the storage of light via the phenomenon of Coherent Population Oscillation (CPO) in an atomic cesium vapor at room temperature. In the experiment the optical information of a probe field is stored in the CPO of two ground states of a Lambda three-level system formed by the Zeeman sublevels of the hyperfine transition F = 3 - F' = 2 of cesium D2 line. We show directly that this CPO based memory is very insensitive to stray magnetic field inhomogeneities and presents a lifetime which is mainly limited only by atomic motion. A theoretical simulation of the measured spectra was also developed and is in very good agreement with the experiment.

A. J. F. de Almeida; J. Sales; M. -A. Maynard; T. Laupretre; F. Bretenaker; D. Felinto; F. Goldfarb; J. W. R. Tabosa

2014-09-19T23:59:59.000Z

75

acoustic phonon scattering: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

type of phononic crystals manufactured Institute of Physics. DOI: 10.10631.2167794 The propagation of acoustic waves in periodic composite Deymier, Pierre 19 Carrier and Phonon...

76

Thermal properties of light nuclei from $^{12}$C+$^{12}$C fusion-evaporation reactions  

E-Print Network [OSTI]

The $^{12}$C+$^{12}$C reaction at 95 MeV has been studied through the complete charge identification of its products by means of the GARFIELD+RCo experimental set-up at INFN Laboratori Nazionali di Legnaro (LNL). In this paper, the first of a series of two, a comparison to a dedicated Hauser-Feshbach calculation allows to select a set of dissipative events which corresponds, to a large extent, to the statistical evaporation of highly excited $^{24}$Mg. Information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain is also extracted. The set of data puts strong constraints on the behaviour of the level density of light nuclei above the threshold for particle emission. In particular, a fast increase of the level density parameter with excitation energy is supported by the data. Residual deviations from a statistical behaviour are seen in two specific channels, and tentatively associated with a contamination from direct reactions and/or $\\alpha$-clustering effects. These channels are studied in further details in the second paper of the series.

L Morelli; G Baiocco; M D'Agostino; F Gulminelli; M Bruno; U Abbondanno; S Appannababu; S Barlini; M Bini; G Casini; M Cinausero; M Degerlier; D Fabris; N Gelli; F Gramegna; V L Kravchuk; T Marchi; G Pasquali; S Piantelli; S Valdré; Ad R Raduta

2014-04-14T23:59:59.000Z

77

Enhancement of coherent energy transfer by disorder and temperature in light harvesting processes  

E-Print Network [OSTI]

We investigate the influence of static disorder and thermal excitations on excitonic energy transport in the light-harvesting apparatus of photosynthetic systems by solving the Schr\\"{o}dinger equation and taking into account the coherent hoppings of excitons, the rates of exciton creation and annihilation in antennas and reaction centers, and the coupling to thermally excited phonons. The antennas and reaction centers are modeled, respectively, as the sources and drains which provide the channels for creation and annihilation of excitons. Phonon modes below a maximum frequency are coupled to the excitons that are continuously created in the antennas and depleted in the reaction centers, and the phonon population in these modes obeys the Bose-Einstein distribution at a given temperature. It is found that the energy transport is not only robust against the static disorder and the thermal noise, but it can also be enhanced by increasing the randomness and temperature in most parameter regimes. Relevance of our work to the highly efficient energy transport in photosynthetic systems is discussed.

Shi-Jie Xiong; Ye Xiong; Yang Zhao

2012-08-27T23:59:59.000Z

78

Specific heat of twisted bilayer graphene: Engineering phonons by atomic plane rotations  

SciTech Connect (OSTI)

We have studied the phonon specific heat in single-layer, bilayer, and twisted bilayer graphene. The calculations were performed using the Born-von Karman model of lattice dynamics for intralayer atomic interactions and spherically symmetric interatomic potential for interlayer interactions. We found that at temperature T?phonon specific heat reveals an intriguing dependence on the twist angle in bilayer graphene, which is particularly pronounced at low temperature. The results suggest a possibility of phonon engineering of thermal properties of layered materials by twisting the atomic planes.

Nika, Denis L. [E. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Department of Physics and Engineering, Moldova State University, Chisinau MD-2009, Republic of Moldova (Moldova, Republic of); Nano-Device Laboratory, Department of Electrical Engineering and Materials Science and Engineering Program, Bourns College of Engineering, University of California—Riverside, Riverside, California, 92521 (United States); Cocemasov, Alexandr I. [E. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Department of Physics and Engineering, Moldova State University, Chisinau MD-2009, Republic of Moldova (Moldova, Republic of); Balandin, Alexander A., E-mail: balandin@ee.ucr.edu [Nano-Device Laboratory, Department of Electrical Engineering and Materials Science and Engineering Program, Bourns College of Engineering, University of California—Riverside, Riverside, California, 92521 (United States)

2014-07-21T23:59:59.000Z

79

Phonon-induced dynamic resonance energy transfer  

E-Print Network [OSTI]

In a network of interacting quantum systems achieving fast coherent energy transfer is a challenging task. While quantum systems are susceptible to a wide range of environmental factors, in many physical settings their interactions with quantized vibrations, or phonons, of a supporting structure are the most prevalent. This leads to noise and decoherence in the network, ultimately impacting the energy-transfer process. In this work, we introduce a novel type of coherent energy-transfer mechanism for quantum systems, where phonon interactions are able to actually enhance the energy transfer. Here, a shared phonon interacts with the systems and dynamically adjusts their resonances, providing remarkable directionality combined with quantum speed- up. We call this mechanism phonon-induced dynamic resonance energy transfer and show that it enables long-range coherent energy transport even in highly disordered systems.

James Lim; Mark Tame; Ki Hyuk Yee; Joong-Sung Lee; Jinhyoung Lee

2014-05-08T23:59:59.000Z

80

Phonons in thin optically irradiated superconductors ; spectrum and possible definition of a phonon temperature  

E-Print Network [OSTI]

615 Phonons in thin optically irradiated superconductors ; spectrum and possible definition supraconducteur en présence d'une irradiation optique pour différentes intensités de la lumière. Nous effec- tuons of the coupled-quasiparticle pair phonon system in a superconducting film in the présence of an optical

Boyer, Edmond

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


81

How Does Folding Modulate Thermal Conductivity of Graphene? Nuo Yang1,2  

E-Print Network [OSTI]

of thermal conductivity is due to scattering of low frequency phonons by the folds. Our results suggest dimensional materials. Keywords Folded graphene ribbon, thermal conductivity, phonon transport, scattering #12 conductivity of low-dimensional silicon and carbon materials11 and graphene ribbons12 were studied by EMD

Li, Baowen

82

Maskless direct laser writing with visible light: Breaking through the optical resolving limit with cooperative manipulations of nonlinear reverse saturation absorption and thermal diffusion  

SciTech Connect (OSTI)

In this work, the resolving limit of maskless direct laser writing is overcome by cooperative manipulation from nonlinear reverse saturation absorption and thermal diffusion, where the nonlinear reverse saturation absorption can induce the formation of below diffraction-limited energy absorption spot, and the thermal diffusion manipulation can make the heat quantity at the central region of energy absorption spot propagate along the thin film thickness direction. The temperature at the central region of energy absorption spot transiently reaches up to melting point and realizes nanolithography. The sample “glass substrate/AgInSbTe” is prepared, where AgInSbTe is taken as nonlinear reverse saturation absorption thin film. The below diffraction-limited energy absorption spot is simulated theoretically and verified experimentally by near-field spot scanning method. The “glass substrate/Al/AgInSbTe” sample is prepared, where the Al is used as thermal conductive layer to manipulate the thermal diffusion channel because the thermal diffusivity coefficient of Al is much larger than that of AgInSbTe. The direct laser writing is conducted by a setup with a laser wavelength of 650?nm and a converging lens of NA=0.85, the lithographic marks with a size of about 100?nm are obtained, and the size is only about 1/10 the incident focused spot. The experimental results indicate that the cooperative manipulation from nonlinear reverse saturation absorption and thermal diffusion is a good method to realize nanolithography in maskless direct laser writing with visible light.

Wei, Jingsong, E-mail: weijingsong@siom.ac.cn [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Wang, Rui [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

2014-03-28T23:59:59.000Z

83

Infrared phonon modes in multiferroic single-crystal FeTe2O5Br  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Reflection and transmission as a function of temperature (7–300 K and 5–300 K respectively) have been measured on single crystals of the multiferroic compound FeTe2O5Br utilizing light spanning from the far infrared to the visible. The complex dielectric function and other optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have led to the observation of 43 of the 53 modes predicted along the b axis of the monoclinic cell. The phonon response parallel to the a and c axes are also presented. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

Miller, K. H.; Xu, X. S.; Berger, H.; Craciun, V.; Xi, Xiaoxiang; Martin, C.; Carr, G. L.; Tanner, D. B.

2013-06-01T23:59:59.000Z

84

Deviational simulation of phonon transport in graphene ribbons with ab initio scattering  

SciTech Connect (OSTI)

We present a deviational Monte Carlo method for solving the Boltzmann-Peierls equation with ab initio 3-phonon scattering, for temporally and spatially dependent thermal transport problems in arbitrary geometries. Phonon dispersion relations and transition rates for graphene are obtained from density functional theory calculations. The ab initio scattering operator is simulated by an energy-conserving stochastic algorithm embedded within a deviational, low-variance Monte Carlo formulation. The deviational formulation ensures that simulations are computationally feasible for arbitrarily small temperature differences, while the stochastic treatment of the scattering operator is both efficient and exhibits no timestep error. The proposed method, in which geometry and phonon-boundary scattering are explicitly treated, is extensively validated by comparison to analytical results, previous numerical solutions and experiments. It is subsequently used to generate solutions for heat transport in graphene ribbons of various geometries and evaluate the validity of some common approximations found in the literature. Our results show that modeling transport in long ribbons of finite width using the homogeneous Boltzmann equation and approximating phonon-boundary scattering using an additional homogeneous scattering rate introduces an error on the order of 10% at room temperature, with the maximum deviation reaching 30% in the middle of the transition regime.

Landon, Colin D.; Hadjiconstantinou, Nicolas G. [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-10-28T23:59:59.000Z

85

Point source in a phononic grating: stop bands give rise to phonon-focusing caustics  

E-Print Network [OSTI]

We use locally-excited gigahertz surface phonon wavepackets in microscopic line structures of different pitches to reveal profound anisotropy in the radiation pattern of a point source in a grating. Time-domain data obtained ...

Maznev, Alex

86

Strongly Enhanced Thermal Transport in a Lightly Doped Mott Insulator at Low Temperature V. Zlatic1,2  

E-Print Network [OSTI]

for various power generation or refrigeration applications which involve so-called green technologies for the charge and thermal transport in a slightly doped Mott insulator that is described by the Falicov, since the magnetic order rarely has a large effect on charge and heat transport in strongly correlated

Freericks, Jim

87

The phonon density of states of (alpha) and (delta)-Plutonium by inelastic x-ray scattering  

SciTech Connect (OSTI)

Inelastic x-ray scattering measurements of the phonon density of states (DOS) were performed on polycrystalline samples of pure {alpha}-Pu and {delta}-Pu{sub 0.98}Ga{sub 0.02} at room temperature. The heat capacity of {alpha}-Pu is well reproduced by contributions calculated from the measured phonon DOS plus conventional thermal expansion and electronic contributions, showing that {alpha}-Pu is a 'well-behaved' metal in this regard. A comparison of the phonon DOS of the two phases at room temperature surprised us in that the vibrational entropy difference between them is only a quarter of the total entropy difference expected from known thermodynamic measurements. The missing entropy is too large to be accounted for by conventional electronic entropy and evidence from the literature rules out a contribution from spin fluctuations. Possible alternative sources for the missing entropy are discussed.

Manley, M E; Said, A; Fluss, M J; Wall, M; Lashley, J C; Alatas, A; Moore, K T

2008-10-08T23:59:59.000Z

88

Establishment of correlated states in a quantum dot interacting with an acoustic phonon reservoir  

E-Print Network [OSTI]

We investigate the effects of a low frequency (acoustic) phonon bath on the dynamics of a quantum dot modelled as a cascade three-level system. We show that the phonon bath appears to the upper transition of the cascade system as a broadband reservoir of inverted rather than conventional harmonic oscillators. The action of the annihilation and creation operators of the inverted oscillator are interchanges relative to those of the usual harmonic oscillator that it serves as a linear amplifier to the system, and thereby gives rise to unusual features in the dynamics of the quantum dot. We find that the phonon bath, although being in a thermal state, affects the quantum dot as a correlated-type reservoir which results in the decay of the system to a correlated two-photon state with the population distribution no longer obeying a Boltzmann distribution. It is particularly interesting that even for a zero temperature phonon reservoir the steady state is a correlated state which under appropriate conditions on the Rabi frequencies and the damping rates can reduce to a strongly correlated pure state. It is shown that the two-photon correlations result in a significant squeezing and strong two-photon correlations in the radiation field emitted by the quantum dot. The presence of the correlations in the system is manifest in the presence of quantum beats in the time evolution of the populations and the radiation intensity. The effect of the ordinary spontaneous emission on the features induced by the phonon bath is also discussed.

Hui Huang; Gao-xiang Li; Wen-ju Gu; Zbigniew Ficek

2014-08-20T23:59:59.000Z

89

Thermally activated delayed fluorescence from {sup 3}n?* to {sup 1}n?* up-conversion and its application to organic light-emitting diodes  

SciTech Connect (OSTI)

Intense n?* fluorescence from a nitrogen-rich heterocyclic compound, 2,5,8-tris(4-fluoro-3-methylphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3MF), is demonstrated. The overlap-forbidden nature of the n?* transition and the higher energy of the {sup 3}??* state than the {sup 3}n?* one lead to a small energy difference between the lowest singlet (S{sub 1}) and triplet (T{sub 1}) excited states of HAP-3MF. Green-emitting HAP-3MF has a moderate photoluminescence quantum yield of 0.26 in both toluene and doped film. However, an organic light-emitting diode containing HAP-3MF achieved a high external quantum efficiency of 6.0%, indicating that HAP-3MF harvests singlet excitons through a thermally activated T{sub 1} ? S{sub 1} pathway in the electroluminescent process.

Li, Jie; Zhang, Qisheng; Nomura, Hiroko [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Miyazaki, Hiroshi [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Functional Materials Laboratory, Nippon Steel and Sumikin Chemical Co., Ltd, 46–80 Nakabaru, Sakinohama, Tobata, Kitakyushu, Fukuoka 804–8503 (Japan); Adachi, Chihaya, E-mail: adachi@cstf.kyushu-u.ac.jp [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

2014-07-07T23:59:59.000Z

90

Neutron Scattering Study of Anharmonic Phonon Dynamics in Thermoelectr...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

4:10 pm LOCATION: Physics 0003 Understanding the Electroweak Symmetry Breaking: The Higgs Boson and Beyond, Chen Li, Oak Ridge National Laboratory Knowledge on phonon...

91

Mode dependent lattice thermal conductivity of single layer graphene  

SciTech Connect (OSTI)

Molecular dynamics simulation is performed to extract the phonon dispersion and phonon lifetime of single layer graphene. The mode dependent thermal conductivity is calculated from the phonon kinetic theory. The predicted thermal conductivity at room temperature exhibits important quantum effects due to the high Debye temperature of graphene. But the quantum effects are reduced significantly when the simulated temperature is as high as 1000?K. Our calculations show that out-of-plane modes contribute about 41.1% to the total thermal conductivity at room temperature. The relative contribution of out-of-plane modes has a little decrease with the increase of temperature. Contact with substrate can reduce both the total thermal conductivity of graphene and the relative contribution of out-of-plane modes, in agreement with previous experiments and theories. Increasing the coupling strength between graphene and substrate can further reduce the relative contribution of out-of-plane modes. The present investigations also show that the relative contribution of different mode phonons is not sensitive to the grain size of graphene. The obtained phonon relaxation time provides useful insight for understanding the phonon mean free path and the size effects in graphene.

Wei, Zhiyong; Yang, Juekuan; Bi, Kedong; Chen, Yunfei, E-mail: yunfeichen@seu.edu.cn [Jiangsu Key Laboratory for Design and Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096 (China)

2014-10-21T23:59:59.000Z

92

Phonon Confinement Effects in Hybrid Virus-Inorganic Nanotubes for  

E-Print Network [OSTI]

Phonon Confinement Effects in Hybrid Virus-Inorganic Nanotubes for Nanoelectronic Applications as nanotemplates, viruses can actually improve the electron transport properties in semiconductor nanotubes grown nanotubes deposited on tobacco mosaic viruses, the confined acoustic phonons are found to be redistributed

Fonoberov, Vladimir

93

Phonon eigenvectors of chiral nanotubes S. Reich and C. Thomsen  

E-Print Network [OSTI]

Phonon eigenvectors of chiral nanotubes S. Reich and C. Thomsen Institut fu¨r Festko of chiral carbon nanotubes may differ signifi- cantly from those of the usually considered, simpler achiral tubes. We show that the phonon eigenvectors, e.g., of the high-energy eigenmodes no longer fall

Nabben, Reinhard

94

Phonon dispersion of carbon nanotubes J. Maultzscha,*, S. Reicha  

E-Print Network [OSTI]

Phonon dispersion of carbon nanotubes J. Maultzscha,*, S. Reicha , C. Thomsena , E. Dobardz the phonon dispersion relations of single-wall carbon nanotubes calculated within a force-constants approach 6 and 12 cm21 independent of the tube diameter. The order of the high-energy modes at the G

Nabben, Reinhard

95

DEVELOPMENT OF PHONON-MEDIATED CRYOGENIC PARTICLE DETECTORS WITH  

E-Print Network [OSTI]

of detectors which are able to reject background events by simultane- ously measuring energy deposited into phonons versus electron hole pairs. By using the phonon sensors with the ionization sensors to compare (background radiation) and nuclear recoil events (dark matter events). These detec- tors with built

California at Berkeley, University of

96

Phonon Mediated Off-Resonant Quantum Dot-Cavity Coupling  

E-Print Network [OSTI]

A theoretical model for the phonon-mediated off-resonant coupling between a quantum dot and a cavity, under resonant excitation of the quantum dot, is presented. We show that the coupling is caused by electron-phonon interaction in the quantum dot and is enhanced by the cavity. We analyze recently observed resonant quantum dot spectroscopic data by our theoretical model.

Arka Majumdar; Yiyang Gong; Erik D. Kim; Jelena Vuckovic

2010-12-14T23:59:59.000Z

97

Observation of acoustic umklapp-phonons in water-stabilized DNA by neutron scattering  

SciTech Connect (OSTI)

We have investigated static and dynamic properties of wet-spun DNA fibers in their C, A, and B conformations using the thermal neutron scattering. Over-damped and underdamped longitudinal acoustic umklapp phonons are observed in the vicinity of a hydration-dependent two-dimensional sheet of diffuse scattering perpendicular to the helix axis. A quantitative analysis of this mode is presented for the B-DNA sample in terms of a harmonic one-dimensional liquid, i.e., taking into account all orders of fluctuations. The resulting effective dispersion does not extrapolate to zero frequency at the position of the sheet.

Grimm, H.; Stiller, H.; Majkrzak, C.F.; Rupprecht, A.; Dahlborg, U.

1987-10-12T23:59:59.000Z

98

High efficiency incandescent lighting  

DOE Patents [OSTI]

Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

2014-09-02T23:59:59.000Z

99

Ballistic thermal point contacts made of GaAs nanopillars  

SciTech Connect (OSTI)

We measure the thermal conductance of GaAs pillars that are only a few nanometers long. Our observations can be understood with a simple model, in which the pillars constitute thermal point contacts between 3D phonon reservoirs. Moreover, first measurements of the electronic transport through these pillars are presented.

Bartsch, Th.; Wetzel, A.; Sonnenberg, D.; Schmidt, M.; Heyn, Ch.; Hansen, W. [Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg (Germany)

2013-12-04T23:59:59.000Z

100

Non-thermal Plasma Chemistry Non-thermal Thermal  

E-Print Network [OSTI]

-thermal Plasma Chemical Flow Reactor #12;Werner von Siemens ,, ... construction of an apparatus generation (1857) pollution control volatile organic components, NOx reforming, ... radiation sources excimer;Leuchtstoffröhre Plasma-Bildschirm Energiesparlampe #12;electrical engineering light sources textile industry

Greifswald, Ernst-Moritz-Arndt-Universität

Note: This page contains sample records for the topic "lighting phonons thermal" 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

NONLINEAR ANALYSIS OF RUBBER-BASED POLYMERIC MATERIALS WITH THERMAL RELAXATION MODELS  

E-Print Network [OSTI]

NONLINEAR ANALYSIS OF RUBBER-BASED POLYMERIC MATERIALS WITH THERMAL RELAXATION MODELS R. V. N of the material and their close connection with the effect of thermal relaxation time can be best appreciated (phonons). A relaxation time appears naturally as the characteristic of thermal resistance in the solid

Melnik, Roderick

102

Thermal conductance of metal-diamond interfaces at high pressure Gregory T. Hohensee  

E-Print Network [OSTI]

are concerned with the exchange of thermal energy across an interface between two materials. This topic-nonmetal interface, a two-temperature model predicts a thermal resistance of Rep = 1/ gL in series with the phononThermal conductance of metal-diamond interfaces at high pressure Gregory T. Hohensee Department

Cahill, David G.

103

Ultralow Thermal Conductivity in Organoclay Nanolaminates Synthesized via Simple Self-Assembly  

E-Print Network [OSTI]

transform fully dense solids into ultralow thermal conductivity materials. Here we report a simple self of nanolaminate spacing. A simple series resistance model describes the behavior and gives an interfacial thermal thermal conductance For phonon-mediated heat conduction, a material is generally thought to reach its

Braun, Paul

104

Electron and Phonon Engineering in Nanostructured Thermoelectric Materials Zhifeng Ren  

E-Print Network [OSTI]

2.00pm Electron and Phonon Engineering in Nanostructured Thermoelectric Materials Zhifeng Ren Department of Physics, Boston College, Chestnut Hill, Massachusetts Abstract Thermoelectric materials a successful case for potentially large scale application using thermoelectric materials. Biography Dr Zhifeng

Levi, Anthony F. J.

105

Phonon diodes and transistors from magneto-acoustics  

E-Print Network [OSTI]

By sculpting the magnetic field applied to magneto-acoustic materials, phonons can be used for information processing. Using a combination of analytic and numerical techniques, we demonstrate designs for diodes (isolators) ...

Sklan, Sophia Robin

106

The Electron-Phonon Interaction as Studied by Photoelectron Spectroscopy  

SciTech Connect (OSTI)

With recent advances in energy and angle resolution, the effects of electron-phonon interactions are manifest in many valence-band photoelectron spectra (PES) for states near the Fermi level in metals.

D.W. Lynch

2004-09-30T23:59:59.000Z

107

Heart - Shaped Nuclei: Condensation of Rotational Aligned Octupole Phonons  

E-Print Network [OSTI]

The strong octupole correlations in the mass region $A\\approx 226$ are interpreted as rotation-induced condensation of octupole phonons having their angular momentum aligned with the rotational axis. Discrete phonon energy and parity conservation generate oscillations of the energy difference between the lowest rotational bands with positive and negative parity. Anharmonicities tend to synchronize the the rotation of the condensate and the quadrupole shape of the nucleus forming a rotating heart shape.

S. Frauendorf

2007-10-24T23:59:59.000Z

108

On virtual phonons, photons and electrons  

E-Print Network [OSTI]

A macroscopic realization of the strange virtual particles is presented. The classical Helmholtz and the quantum mechanical Schr\\"odinger equations are analogous differential equations. Their imaginary solutions are called evanescent modes in the case of elastic and electromagnetic fields. In the case of non-relativistic quantum mechanical fields they are called tunneling solutions. The imaginary solutions of this differential equation point to strange consequences: They are non local, they are not observable, and they described as virtual particles. During the last two decades QED calculations of the imaginary solutions have been experimentally confirmed for phonons, photons, and for electrons. The experimental proofs of the predictions of the non-relativistic quantum mechanics and of the Wigner phase time approach for the elastic, the electromagnetic and the Schr\\"odinger fields will be presented in this article. The results are zero tunneling time and an interaction time (i.e. a phase shift) at the barrier interfaces. The measured barrier interaction time (i.e. the barrier transmission time) scales approximately inversely with the particle energy.

G. Nimtz

2009-07-09T23:59:59.000Z

109

Phonon dispersion curves determination in (delta)-phase Pu-Ga alloys  

SciTech Connect (OSTI)

We have designed and successfully employed a novel microbeam on large grain sample concept to conduct high resolution inelastic x-ray scattering (HRIXS) experiments to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features may be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. We also conducted thermal diffuse scattering experiments to study the T(111) dispersion at low temperatures with an attempt to gain insight into bending of the T(111) branch in relationship to the {delta} {yields} {alpha}{prime} transformation.

Wong, J; Clatterbuck, D; Occelli, F; Farber, D; Schwartz, A; Wall, M; Boro, C; Krisch, M; Beraud, A; Chiang, T; Xu, R; Hong, H; Zschack, P; Tamura, N

2006-02-07T23:59:59.000Z

110

Thermal trim for luminaire  

DOE Patents [OSTI]

A luminaire with a thermal pathway to reduce the junction temperature of the luminaire's light source, and methods for so doing, are disclosed. The luminaire includes a can, a light engine, and a trim, that define a substantially continuous thermal pathway from the light engine to a surrounding environment. The can defines a can cavity and includes a can end region. The light engine is within the can cavity and includes a light source and a heat sink, including a heat sink end region, coupled thereto. The trim is at least partially disposed within the can cavity and includes a first trim end region coupled to the heat sink end region and a second trim end region coupled to the can end region. Thermal interface material may be located between: the heat sink and the trim, the trim and the can, and/or the heat sink and the light source.

Bazydola, Sarah; Ghiu, Camil-Daniel; Harrison, Robert; Jeswani, Anil

2013-11-19T23:59:59.000Z

111

Thermal conductivity of graphene nanoribbons in noble gaseous environments  

SciTech Connect (OSTI)

We investigate the thermal conductivity of suspended graphene nanoribbons in noble gaseous environments using molecular dynamics simulations. It is reported that the thermal conductivity of perfect graphene nanoribbons decreases with the gaseous pressure. The decreasing is more obvious for the noble gas with large atomic number. However, the gaseous pressure cannot change the thermal conductivity of defective graphene nanoribbons apparently. The phonon spectra of graphene nanoribbons are also provided to give corresponding supports.

Zhong, Wei-Rong, E-mail: wrzhong@hotmail.com; Xu, Zhi-Cheng; Zheng, Dong-Qin [Department of Physics and Siyuan Laboratory, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Ai, Bao-Quan, E-mail: aibq@scnu.edu.cn [Laboratory of Quantum Information Technology, ICMP and SPTE, South China Normal University, Guangzhou 510006 (China)

2014-02-24T23:59:59.000Z

112

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

113

High temperature phonon dispersion in graphene using classical molecular dynamics  

SciTech Connect (OSTI)

Phonon dispersion and phonon density of states of graphene are calculated using classical molecular dynamics simulations. In this method, the dynamical matrix is constructed based on linear response theory by computing the displacement of atoms during the simulations. The computed phonon dispersions show excellent agreement with experiments. The simulations are done in both NVT and NPT ensembles at 300 K and found that the LO/TO modes are getting hardened at the ? point. The NPT ensemble simulations capture the anharmonicity of the crystal accurately and the hardening of LO/TO modes is more pronounced. We also found that at 300 K the C-C bond length reduces below the equilibrium value and the ZA bending mode frequency becomes imaginary close to ? along K-? direction, which indicates instability of the flat 2D graphene sheets.

Anees, P., E-mail: anees@igcar.gov.in; Panigrahi, B. K. [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Valsakumar, M. C., E-mail: anees@igcar.gov.in [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad-500046 (India)

2014-04-24T23:59:59.000Z

114

Anharmonic phonons and magnons in BiFeO3  

SciTech Connect (OSTI)

The phonon density of states (DOS) and magnetic excitation spectrum of polycrystalline BiFeO3 were measured for temperatures 200 < T < 750K , using inelastic neutron scattering (INS). Our results indicate that the magnetic spectrum of BiFeO3 closely resembles that of similar Fe perovskites, such as LaFeO3, despite the cycloid modulation in BiFeO3. We do not find any evidence for a spin gap. A strong T-dependence of the phonon DOS was found, with a marked broadening of the whole spectrum, providing evidence of strong anharmonicity. This anharmonicity is corroborated by large amplitude motions of Bi and O ions observed with neutron diffraction. These results highlight the importance of spin-phonon coupling in this material.

Delaire, Olivier A [ORNL; Ma, Jie [ORNL; Stone, Matthew B [ORNL; Huq, Ashfia [ORNL; Gout, Delphine J [ORNL; Brown, Craig [National Institute of Standards and Technology (NIST); Wang, Kefeng [Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing; Ren, Zhifeng [Boston College, Chestnut Hill

2012-01-01T23:59:59.000Z

115

Chirality dependence of coherent phonon amplitudes in single-wall carbon nanotubes  

E-Print Network [OSTI]

We simulate the ultrafast dynamics of laser-induced coherent phonons in single-wall carbon nanotubes (SWNTs). In particular, we examine the coherent phonon amplitude of the radial breathing mode (RBM) as a function of ...

Dresselhaus, Mildred

116

Unraveling the interlayer-related phonon self-energy renormalization in bilayer graphene  

E-Print Network [OSTI]

In this letter, we present a step towards understanding the bilayer graphene (2LG) interlayer (IL)-related phonon combination modes and overtones as well as their phonon self-energy renormalizations by using both gate-modulated ...

Araujo, Paulo Antonio Trinidade

117

Nanoscale thermal transport. II. 2003–2012  

SciTech Connect (OSTI)

A diverse spectrum of technology drivers such as improved thermal barriers, higher efficiency thermoelectric energy conversion, phase-change memory, heat-assisted magnetic recording, thermal management of nanoscale electronics, and nanoparticles for thermal medical therapies are motivating studies of the applied physics of thermal transport at the nanoscale. This review emphasizes developments in experiment, theory, and computation in the past ten years and summarizes the present status of the field. Interfaces become increasingly important on small length scales. Research during the past decade has extended studies of interfaces between simple metals and inorganic crystals to interfaces with molecular materials and liquids with systematic control of interface chemistry and physics. At separations on the order of ?1?nm, the science of radiative transport through nanoscale gaps overlaps with thermal conduction by the coupling of electronic and vibrational excitations across weakly bonded or rough interfaces between materials. Major advances in the physics of phonons include first principles calculation of the phonon lifetimes of simple crystals and application of the predicted scattering rates in parameter-free calculations of the thermal conductivity. Progress in the control of thermal transport at the nanoscale is critical to continued advances in the density of information that can be stored in phase change memory devices and new generations of magnetic storage that will use highly localized heat sources to reduce the coercivity of magnetic media. Ultralow thermal conductivity—thermal conductivity below the conventionally predicted minimum thermal conductivity—has been observed in nanolaminates and disordered crystals with strong anisotropy. Advances in metrology by time-domain thermoreflectance have made measurements of the thermal conductivity of a thin layer with micron-scale spatial resolution relatively routine. Scanning thermal microscopy and thermal analysis using proximal probes has achieved spatial resolution of 10?nm, temperature precision of 50 mK, sensitivity to heat flows of 10 pW, and the capability for thermal analysis of sub-femtogram samples.

Cahill, David G., E-mail: d-cahill@illinois.edu; Braun, Paul V. [Department of Materials Science and Engineering and the Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States); Chen, Gang [Department of Mechanical Engineering, MIT, Cambridge, Massachusetts 02139 (United States); Clarke, David R. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Fan, Shanhui [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Goodson, Kenneth E. [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Keblinski, Pawel [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); King, William P. [Department of Mechanical Sciences and Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Mahan, Gerald D. [Department of Physics, Penn State University, University Park, Pennsylvania 16802 (United States); Majumdar, Arun [Department of Mechanical Engineering, University of California, Berkeley, California 94720 (United States); Maris, Humphrey J. [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States); Phillpot, Simon R. [Department of Materials Science and Engineering, University of Florida, Gainseville, Florida 32611 (United States); Pop, Eric [Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Shi, Li [Department of Mechanical Engineering, University of Texas, Autin, Texas 78712 (United States)

2014-03-15T23:59:59.000Z

118

Phonon-assisted robust and deterministic two-photon biexciton preparation in a quantum dot  

E-Print Network [OSTI]

We investigate both experimentally and theoretically a simple yet more robust and flexible alternative to Rabi oscillation-type biexciton preparation protocols traditionally used for semiconductor quantum dots. The quantum dot is excited by a strong laser pulse positively detuned from the two-photon resonance yielding an on demand initialization of the biexciton state by making use of the phonon-induced thermalization of the photon dressed states. It is shown that for excitation pulses in the picosecond range, a stable and high fidelity of up to $f_{XX}=0.98\\pm 0.01$ is reached. Notably, the generated photons show similar coherence properties as measured in the resonant two-photon scheme. This protocol is a powerful tool for the control of complex solid state systems combining radiative cascades, entanglement and resonant cavity modes.

S. Bounouar; M. Müller; A. M. Barth; M. Glässl; V. M. Axt; P. Michler

2014-08-29T23:59:59.000Z

119

Basal-plane thermal conductivity of few-layer molybdenum disulfide  

SciTech Connect (OSTI)

We report the in-plane thermal conductivity of suspended exfoliated few-layer molybdenum disulfide (MoS{sub 2}) samples that were measured by suspended micro-devices with integrated resistance thermometers. The obtained room-temperature thermal conductivity values are (44–50) and (48–52) W m{sup ?1} K{sup ?1} for two samples that are 4 and 7 layers thick, respectively. For both samples, the peak thermal conductivity occurs at a temperature close to 120?K, above which the thermal conductivity is dominated by intrinsic phonon-phonon scattering although phonon scattering by surface disorders can still play an important role in these samples especially at low temperatures.

Jo, Insun; Ou, Eric; Shi, Li, E-mail: lishi@mail.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Pettes, Michael Thompson [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Department of Mechanical Engineering and the Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Wu, Wei [Department of Mechanical Engineering and the Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States)

2014-05-19T23:59:59.000Z

120

Infrared phonon modes in multiferroic single-crystal FeTe2O5Br  

SciTech Connect (OSTI)

Reflection and transmission as a function of temperature (7–300 K and 5–300 K respectively) have been measured on single crystals of the multiferroic compound FeTe2O5Br utilizing light spanning from the far infrared to the visible. The complex dielectric function and other optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have led to the observation of 43 of the 53 modes predicted along the b axis of the monoclinic cell. The phonon response parallel to the a and c axes are also presented. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

Miller, K. H.; Xu, X. S.; Berger, H.; Craciun, V.; Xi, Xiaoxiang; Martin, C.; Carr, G. L.; Tanner, D. B.

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Exploiting structured environments for efficient energy transfer: The phonon antenna mechanism  

E-Print Network [OSTI]

A non-trivial interplay between quantum coherence and dissipative environment-driven dynamics is becoming increasingly recognised as key for efficient energy transport in photosynthetic pigment-protein complexes, and converting these biologically-inspired insights into a set of design principles that can be implemented in artificial light-harvesting systems has become an active research field. Here we identify a specific design principle - the phonon antenna - that demonstrates how inter-pigment coherence is able to modify and optimize the way that excitations spectrally sample their local environmental fluctuations. We place this principle into a broader context and furthermore we provide evidence that the Fenna-Matthews-Olson complex of green sulphur bacteria has an excitonic structure that is close to such an optimal operating point, and suggest that this general design principle might well be exploited in other biomolecular systems.

M. del Rey; A. W. Chin; S. F. Huelga; M. B. Plenio

2012-11-29T23:59:59.000Z

122

Indoor air movement acceptability and thermal comfort in hot-humid climates  

E-Print Network [OSTI]

HVAC) and the thermal envelope of buildings, but designments concern the thermal envelope, lighting and acoustics,HVAC and building’s thermal envelope. Yet requirements for

Candido, Christhina Maria

2010-01-01T23:59:59.000Z

123

Active Thermal Extraction of Near-field Thermal Radiation  

E-Print Network [OSTI]

Radiative heat transport between materials supporting surface-phonon polaritons is greatly enhanced when the materials are placed at sub-wavelength separation as a result of the contribution of near-field surface modes. However, the enhancement is limited to small separations due to the evanescent decay of the surface waves. In this work, we propose and numerically demonstrate an active scheme to extract these modes to the far-field. Our approach exploits the monochromatic nature of near-field thermal radiation to drive a transition in a laser gain medium, which, when coupled with external optical pumping, allows the resonant surface mode to be emitted into the far-field. Our study demonstrates a new approach to manipulate thermal radiation that could find applications in thermal management.

Ding, Ding

2015-01-01T23:59:59.000Z

124

Enhanced Electron-Phonon Coupling at Metal Surfaces  

SciTech Connect (OSTI)

The Born-Oppenheimer approximation (BOA) decouples electronic from nuclear motion, providing a focal point for most quantum mechanics textbooks. However, a multitude of important chemical, physical and biological phenomena are driven by violations of this approximation. Vibronic interactions are a necessary ingredient in any process that makes or breaks a covalent bond, for example, conventional catalysis or enzymatically delivered biological reactions. Metastable phenomena associated with defects and dopants in semiconductors, oxides, and glasses entail violation of the BOA. Charge exchange in inorganic polymers, organic slats and biological systems involves charge- induced distortions of the local structure. A classic example is conventional superconductivity, which is driven by the electron-lattice interaction. High-resolution angle-resolved photoemission experiments are yielding new insight into the microscopic origin of electron-phonon coupling (EPC) in anisotropic two-dimensional systems. Our recent surface phonon measurement on the surface of a high-Tc material clearly indicates an important momentum dependent EPC in these materials. In the last few years we have shifted our research focus from solely looking at electron phonon coupling to examining the structure/functionality relationship at the surface of complex transition metal compounds. The investigation on electron phonon coupling has allowed us to move to systems where there is coupling between the lattice, the electrons and the spin.

Plummer, Ward E.

2010-08-04T23:59:59.000Z

125

Phonon-enhanced crystal growth and lattice healing  

DOE Patents [OSTI]

A system for modifying dislocation distributions in semiconductor materials is provided. The system includes one or more vibrational sources for producing at least one excitation of vibrational mode having phonon frequencies so as to enhance dislocation motion through a crystal lattice.

Buonassisi, Anthony; Bertoni, Mariana; Newman, Bonna

2013-05-28T23:59:59.000Z

126

Phonons in quantum dots and their role in exciton dephasing  

E-Print Network [OSTI]

-nitrides. Values are taken from [5]. The values for the nitride compounds are taken from density functional dots (QDs). The state of the art is reported in detail in the present book. A large application- driven the theory of acoustic phonons in QDs is explained in Sec. 3. Special emphasis is given to continuum

Zimmermann, Roland

127

Freie Universitt Berlin Transient reflectivity and coherent phonon  

E-Print Network [OSTI]

Freie Universität Berlin Transient reflectivity and coherent phonon excitation: An ultrafast probe-Hubbard? . . . . . . 35 1.3.3 The photoinduced phase transition . . . . . . . . . . . . . . . . . . . 36 I #12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 2.1.1 Generation of ultrashort laser pulses: the mode-locked Ti:Sapphire oscillator

Wolf, Martin

128

Phonon dispersion and quantization tuning of strained carbon nanotubes for flexible electronics  

SciTech Connect (OSTI)

Graphene and carbon nanotubes are materials with large potentials for applications in flexible electronics. Such devices require a high level of sustainable strain and an understanding of the materials electrical properties under strain. Using supercell theory in conjunction with a comprehensive molecular mechanics model, the full band phonon dispersion of carbon nanotubes under uniaxial strain is studied. The results suggest an overall phonon softening and open up the possibility of phonon quantization tuning with uniaxial strain. The change in phonon quantization and the resulting increase in electron-phonon and phonon-phonon scattering rates offer further explanation and theoretical basis to the experimental observation of electrical properties degradation for carbon nanotubes under uniaxial strain.

Gautreau, Pierre; Chu, Yanbiao; Basaran, Cemal [Electronic Packaging Laboratory, State University of New York at Buffalo, 102 Ketter Hall, Buffalo, New York 14260 (United States); Ragab, Tarek [Electronic Packaging Laboratory, State University of New York at Buffalo, 102 Ketter Hall, Buffalo, New York 14260 (United States); Nanotechnology Research Laboratory, University of Tabuk, Tabuk, 71491, Saudi Arabia and Faculty of Engineering, Alexandria University, Alexandria 21526 (Egypt)

2014-06-28T23:59:59.000Z

129

Thermal conductance of graphene and dimerite Jin-Wu Jiang,1 Jian-Sheng Wang,1 and Baowen Li1,2,*  

E-Print Network [OSTI]

Thermal conductance of graphene and dimerite Jin-Wu Jiang,1 Jian-Sheng Wang,1 and Baowen Li1,2,* 1; published 20 May 2009 We investigate the phonon thermal conductance of graphene regarding the graphene sheet as the large-width limit of graphene strips in the ballistic limit. We find that the thermal conductance

Li, Baowen

130

Battle against Phonons (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum  

ScienceCinema (OSTI)

'Battle against Phonons' was submitted by the Solid-State Solar-Thermal Energy Conversion (S3TEC) EFRC to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. This video was selected as one of five winners by a distinguished panel of judges for the special award, 'Best with Popcorn'. S3TEC, an EFRC directed by Gang Chen at the Massachusetts Institute of Technology is a partnership of scientists from four research institutions: MIT (lead), Oak Ridge National Laboratory, Boston College, and Rensselaer Polytechnic Institute. The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of the Solid-State Solar Thermal Energy Conversion Center is 'to create novel, solid-state materials for the conversion of sunlight into electricity using thermal and photovoltaic processes.' Research topics are: solar photovoltaic, photonic, metamaterial, optics, solar thermal, thermoelectric, phonons, thermal conductivity, defects, ultrafast physics, interfacial characterization, matter by design, novel materials synthesis, charge transport, defect tolerant materials, and scalable processing.

Chen, Gang (Director, Solid-State Solar-Thermal Energy Conversion Center); S3TEC Staff

2011-11-02T23:59:59.000Z

131

Cross-plane thermal properties of transition metal dichalcogenides  

SciTech Connect (OSTI)

In this work, we explore the thermal properties of hexagonal transition metal dichalcogenide compounds with different average atomic masses but equivalent microstructures. Thermal conductivity values of sputtered thin films were compared to bulk crystals. The comparison revealed a >10 fold reduction in thin film thermal conductivity. Structural analysis of the films revealed a turbostratic structure with domain sizes on the order of 5-10 nm. Estimates of phonon scattering lengths at domain boundaries based on computationally derived group velocities were consistent with the observed film microstructure, and accounted for the reduction in thermal conductivity compared to values for bulk crystals.

Muratore, C. [Department of Chemical and Materials Engineering, University of Dayton, Dayton, Ohio 45469 (United States) [Department of Chemical and Materials Engineering, University of Dayton, Dayton, Ohio 45469 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Varshney, V. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States) [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Universal Technology Corporation, Dayton, Ohio 45432 (United States); Gengler, J. J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States) [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Spectral Energies LLC, Dayton, Ohio 45431 (United States); Hu, J. J.; Bultman, J. E. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States) [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); University of Dayton Research Institute, Dayton, Ohio 45469 (United States); Smith, T. M. [Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States)] [Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Shamberger, P. J.; Roy, A. K.; Voevodin, A. A. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)] [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Qiu, B.; Ruan, X. [Department of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)] [Department of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)

2013-02-25T23:59:59.000Z

132

Light Steel Framing: Improving the Integral Design   

E-Print Network [OSTI]

Light Steel Framing has been extensively used in cold climate countries due to its good thermal and structural behaviour. Improved thermal behaviour results in positive environmental impact essential for sustainable ...

Amundarain, Aitor; Torero, Jose L; Usmani, Asif; Al-Remal, Ahmad M

2006-09-11T23:59:59.000Z

133

Thermal Fluids  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Thermal Fluids The Thermal Fluids and Heat Transfer program works on thermal hydraulic reactor safety code development and experimental heat transferthermal hydraulics. The...

134

Structural and phonon transmission study of Ge-Au-Ge eutectically bonded interfaces  

SciTech Connect (OSTI)

This thesis presents a structural analysis and phonon transparency investigation of the Ge-Au-Ge eutectic bond interface. Interface development was intended to maximize the interfacial ballistic phonon transparency to enhance the detection of the dark matter candidate WIMPs. The process which was developed provides an interface which produces minimal stress, low amounts of impurities, and insures Ge lattice continuity through the interface. For initial Au thicknesses of greater than 1,000 {angstrom} Au per substrate side, eutectic epitaxial growth resulted in a Au dendritic structure with 95% cross sectional and 90% planar Au interfacial area coverages. In sections in which Ge bridged the interface, lattice continuity across the interface was apparent. Epitaxial solidification of the eutectic interface with initial Au thicknesses < 500 A per substrate side produced Au agglomerations thereby reducing the Au planar interfacial area coverage to as little as 30%. The mechanism for Au coalescence was attributed to lateral diffusion of Ge and Au in the liquid phase during solidification. Phonon transmission studies were performed on eutectic interfaces with initial Au thicknesses of 1,000 {angstrom}, 500 {angstrom}, and 300 {angstrom} per substrate side. Phonon imaging of eutectically bonded samples with initial Au thicknesses of 300 {angstrom}/side revealed reproducible interfacial percent phonon transmissions from 60% to 70%. Line scan phonon imaging verified the results. Phonon propagation TOF spectra distinctly showed the predominant phonon propagation mode was ballistic. This was substantiated by phonon focusing effects apparent in the phonon imaging data. The degree of interface transparency to phonons and resulting phonon propagation modes correlate with the structure of the interface following eutectic solidification. Structural studies of samples with initial Au thickness of 1,000 {angstrom}/side appear to correspond with the phonon transmission study.

Knowlton, W.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.

1995-07-01T23:59:59.000Z

135

Plasmon-phonon interactions in topological insulator rings  

E-Print Network [OSTI]

The great potential of Dirac electrons for plasmonics and photonics has been readily recognized after their discovery in graphene, followed by applications to smart optical devices. Dirac carriers are also found in topological insulators (TI) --quantum systems having an insulating gap in the bulk and intrinsic Dirac metallic states at the surface--. Here, we investigate the plasmonic response of ring structures patterned in Bi$_2$Se$_3$ TI films, which we investigate through terahertz (THz) spectroscopy. The rings are observed to exhibit a bonding and an antibonding plasmon modes, which we tune in frequency by varying their diameter. We develop an analytical theory based on the THz conductivity of unpatterned films, which accurately describes the strong plasmon-phonon hybridization and Fano interference experimentally observed as the bonding plasmon is swiped across the promineng 2\\,THz phonon exhibited by this material. This work opens the road for the investigation of plasmons in topological insulators and ...

Autore, Marta; Di Gaspare, Alessandra; Giliberti, Valeria; Limaj, Odeta; Roy, Pascale; Brahlek, Matthew; Koirala, Nikesh; Oh, Seongshik; de Abajo, Francisco Javier Garcìa; Lupi, Stefano

2015-01-01T23:59:59.000Z

136

Phonon drag of electrons in Ag{sub 2}S  

SciTech Connect (OSTI)

The temperature dependences of the heat-conductivity coefficient {chi} and the thermopower 6h of Ag{sub 2}S are investigated in the range of 4.2-300 K. It is found that the value of 6h sharply increases (6h {infinity} T{sup -3}) with decreasing T at T < 100 K and passes through a maximum at 16-18 K. The heat-conductivity coefficient passes through a maximum at {approx}30 K. The sharp increase in 6h is found to be caused by the effect of long-wavelength-phonon drag of electrons. It is shown that the shift of the 6h and {chi} peaks, as well as the temperature dependence of the phonon thermopower 6h{sub ph} {infinity} T{sup -3}, agrees with the Herring theory.

Aliev, S. A.; Aliev, F. F., E-mail: farzali@physics.ab.az; Gasanov, Z. S.; Abdullayev, S. M.; Selim-zade, R. I. [Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

2010-06-15T23:59:59.000Z

137

Disentangling phonon and impurity interactions in ?-doped Si(001)  

SciTech Connect (OSTI)

We present a study of the phonon and impurity interactions in a shallow two dimensional electron gas formed in Si(001). A highly conductive ultra-narrow n-type dopant ?-layer, which serves as a platform for quantum computation architecture, is formed and studied by angle resolved photoemission spectroscopy (ARPES) and temperature dependent nanoscale 4-point probe (4PP). The bandstructure of the ?-layer state is both measured and simulated. At 100?K, good agreement is only achieved by including interactions; electron-impurity scattering (W{sub 0}?=?56 to 61?meV); and electron-phonon coupling (??=?0.14?±?0.04). These results are shown to be consistent with temperature dependent 4PP resistance measurements which indicate that at 100?K, ?7?8 of the measured resistance is due to impurity scattering with the remaining 1/8 coming from phonon interactions. In both resistance and bandstructure measurements, the impurity contribution exhibits a variability of ?9% for nominally identical samples. The combination of ARPES and 4PP affords a thorough insight into the relevant contributions to electrical resistance in reduced dimensionality electronic platforms.

Mazzola, Federico; Wells, Justin W., E-mail: quantum.wells@gmail.com [Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim (Norway); Polley, Craig M. [MAX IV Laboratory, Lund University, 221 00 Lund (Sweden); School of Physics, Centre of Excellence for Quantum Computation and Communication Technology, University of New South Wales, Sydney, NSW 2052 (Australia); Miwa, Jill A. [Department of Physics and Astronomy, Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, 8000 Aarhus C (Denmark); Simmons, Michelle Y. [School of Physics, Centre of Excellence for Quantum Computation and Communication Technology, University of New South Wales, Sydney, NSW 2052 (Australia)

2014-04-28T23:59:59.000Z

138

Phonons in a one-dimensional microfluidic crystal  

E-Print Network [OSTI]

The development of a general theoretical framework for describing the behaviour of a crystal driven far from equilibrium has proved difficult1. Microfluidic crystals, formed by the introduction of droplets of immiscible fluid into a liquid-filled channel, provide a convenient means to explore and develop models to describe non-equilibrium dynamics2, 3, 4, 5, 6, 7, 8, 9, 10, 11. Owing to the fact that these systems operate at low Reynolds number (Re), in which viscous dissipation of energy dominates inertial effects, vibrations are expected to be over-damped and contribute little to their dynamics12, 13, 14. Against such expectations, we report the emergence of collective normal vibrational modes (equivalent to acoustic 'phonons') in a one-dimensional microfluidic crystal of water-in-oil droplets at Reapprox10-4. These phonons propagate at an ultra-low sound velocity of approx100 mum s-1 and frequencies of a few hertz, exhibit unusual dispersion relations markedly different to those of harmonic crystals, and give rise to a variety of crystal instabilities that could have implications for the design of commercial microfluidic systems. First-principles theory shows that these phonons are an outcome of the symmetry-breaking flow field that induces long-range inter-droplet interactions, similar in nature to those observed in many other systems including dusty plasma crystals15, 16, vortices in superconductors17, 18, active membranes19 and nucleoprotein filaments20.

Tsevi Beatus; Tsvi Tlusty; Roy Bar-Ziv

2010-08-06T23:59:59.000Z

139

Solid state lighting component  

DOE Patents [OSTI]

An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.

Yuan, Thomas; Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald

2010-10-26T23:59:59.000Z

140

Solid state lighting component  

DOE Patents [OSTI]

An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.

Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald; Yuan, Thomas

2012-07-10T23:59:59.000Z

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


141

Thermal expansion and lattice dynamics of RB66 compounds at low temperatures  

SciTech Connect (OSTI)

Thermal characteristics of the phonon and magnon subsystems of icosahedral borides RB66 (R = Gd, Tb, Dy, Ho, Eu, or Lu) have been studied based on the obtained experimental data on the thermal expansion of the borides and the earlier results on their heat capacity in the range of 2–300 K. The contribution to the expansion of borides containing paramagnetic R 3+ ions, which is characteristic of transition to the spin-glass state, has been revealed. The phonon spectrum moments of RB66 compounds and the Grüneisen parameters have been calculated.

Novikov, V V [Petrovsky Bryansk State University; Avdashchenko, D V [Petrovsky Bryansk State University; Mitroshenkov, N V [Petrovsky Bryansk State University; Matovnikov, A V [Petrovsky Bryansk State University; Budko, Serguei L [Ames Laboratory

2014-10-01T23:59:59.000Z

142

Phonon lifetime in SiSn and its suitability for hot-carrier solar cells  

SciTech Connect (OSTI)

We present a phononic and electronic study of SiSn in the zinc-blende phase. A detailed description of the longitudinal optical (LO) phonon decay in a three-phonon process is presented together with the corresponding lifetime. The necessity to go beyond the zone center phonon approximation in this case is highlighted as it reveals a steep dependence of the lifetime on the initial phonon wavenumber, which differs from usual semiconductors. The electronic band structure is calculated within the GW formalism and shows a small direct band gap. It is shown that the LO-phonon resulting from electron cooling has a lifetime four to eight orders of magnitude above all the known value in semiconductors for this process. We finally show the suitability of SiSn for hot-carrier solar cells, as it is endowed with ultra-slow cooling of hot carriers.

Levard, Hugo; Laribi, Sana; Guillemoles, Jean-François [Institute for Research and Development on Photovoltaic Energy (IRDEP), UMR 7174, EDF R and D/CNRS/Chimie ParisTech, 6 quai Watier, 78401 Chatou (France)

2014-06-02T23:59:59.000Z

143

Lighting system with heat distribution face plate  

DOE Patents [OSTI]

Lighting systems having a light source and a thermal management system are provided. The thermal management system includes synthetic jet devices, a heat sink and a heat distribution face plate. The synthetic jet devices are arranged in parallel to one and other and are configured to actively cool the lighting system. The heat distribution face plate is configured to radially transfer heat from the light source into the ambient air.

Arik, Mehmet; Weaver, Stanton Earl; Stecher, Thomas Elliot; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Li, Ri

2013-09-10T23:59:59.000Z

144

Thermal trim for a luminaire  

DOE Patents [OSTI]

A luminaire with a thermal pathway to reduce the junction temperature of the luminaire's light source, and methods for so doing, are disclosed. The luminaire includes a can, a light engine, and a trim, that define a substantially continuous thermal pathway from the light engine to a surrounding environment. The can defines a can cavity and includes a can end region. The light engine is within the can cavity and includes a light source and a heat sink, including a heat sink end region, coupled thereto. The trim is at least partially disposed within the can cavity and includes a first trim end region coupled to the heat sink end region and a second trim end region coupled to the can end region. Thermal interface material may be located between: the heat sink and the trim, the trim and the can, and/or the heat sink and the light source.

Bazydola, Sarah; Ghiu, Camil-Daniel; Harrison, Robert; Jeswani, Anil

2013-02-19T23:59:59.000Z

145

Identification of excitonic phonon sideband by photoluminescence spectroscopy of single-walled carbon-13 nanotubes  

E-Print Network [OSTI]

1 Identification of excitonic phonon sideband by photoluminescence spectroscopy of single of the most promising approaches for the determination of the structure distribution in a bulk SWNT sample

Maruyama, Shigeo

146

E-Print Network 3.0 - additional phonon modes Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

at Stony Brook, Department of Electrical Engineering and Computer Engineering, Optoelectronics Research Group Collection: Engineering 19 Phonon populations and electrical power...

147

E-Print Network 3.0 - absorption phonon raman Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Powered by Explorit Topic List Advanced Search Sample search results for: absorption phonon raman Page: << < 1 2 3 4 5 > >> 1 SELECTION RULES FOR SECOND ORDER INFRARED...

148

Second Harmonic Generation and Confined Acoustic Phonons in Highly Excited Semiconductor Nanocrystals  

E-Print Network [OSTI]

Second harmonic generation and confined acoustic phonons inenhancement of second harmonic generation, and the effect ofmeasurements. The second harmonic signal showed a sublinear

Son, Dong Hee; Wittenberg, Joshua S.; Banin, Uri; Alivisatos, A. Paul

2006-01-01T23:59:59.000Z

149

Anisotropic surface phonon dispersion of the hydrogen-terminated Si(110)-(1×1) surface: One-dimensional phonons propagating along the glide planes  

SciTech Connect (OSTI)

We have measured the surface phonon dispersion curves on the hydrogen-terminated Si(110)-(1×1) surface with the two-dimensional space group of p2mg along the two highly symmetric and rectangular directions of ?X{sup ¯} and ?X{sup ?¯} using high-resolution electron-energy-loss spectroscopy. All the essential energy-loss peaks on H:Si(110) were assigned to the vibrational phonon modes by using the selection rules of inelastic electron scattering including the glide-plane symmetry. Actually, the surface phonon modes of even-symmetry to the glide plane (along ?X{sup ¯}) were observed in the first Brillouin zone, and those of odd-symmetry to the glide plane were in the second Brillouin zone. The detailed assignment was made by referring to theoretical phonon dispersion curves of Gräschus et al. [Phys. Rev. B 56, 6482 (1997)]. We found that the H–Si stretching and bending modes, which exhibit highly anisotropic dispersion, propagate along ?X{sup ¯} direction as a one-dimensional phonon. Judging from the surface structure as well as our classical and quantum mechanical estimations, the H–Si stretching phonon propagates by a direct repulsive interaction between the nearest neighbor H atoms facing each other along ?X{sup ¯}, whereas the H–Si bending phonon propagates by indirect interaction through the substrate Si atomic linkage.

Matsushita, Stephane Yu; Matsui, Kazuki; Kato, Hiroki; Suto, Shozo, E-mail: suto@surface.phys.tohoku.ac.jp [Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan)] [Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Yamada, Taro [RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)] [RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)

2014-03-14T23:59:59.000Z

150

A deviational Monte Carlo formulation of ab initio phonon transport and its application to the study of kinetic effects in graphene ribbons  

E-Print Network [OSTI]

We present a deviational Monte Carlo method for solving the Boltzmann equation for phonon transport subject to the linearized ab initio 3-phonon scattering operator. Phonon dispersion relations and transition rates are ...

Landon, Colin Donald

2014-01-01T23:59:59.000Z

151

Lattice NRQCD study of S- and P-wave bottomonium states in a thermal medium with $N_f=2+1$ light flavors  

E-Print Network [OSTI]

We investigate the properties of S-and P-wave bottomonium states in the vicinity of the deconfinement transition temperature. The light degrees of freedom are represented by dynamical lattice QCD configurations of the HotQCD collaboration with $N_f = 2 + 1$ flavors. Bottomonium correlators are obtained from bottom quark propagators, computed in Non-Relativistic QCD (NRQCD) under the background of these gauge field configurations. The spectral functions for the $^3S_1$ ($\\Upsilon$) and $^3P_1$ ($\\chi_{b1}$) channel are extracted from the Euclidean time correlators using a novel Bayesian approach in the temperature region $140 {\\rm MeV} \\le T \\le 249 {\\rm MeV}$ and the results are contrasted to those from the standard Maximum Entropy Method. We find that the new Bayesian approach is far superior to the Maximum Entropy Method and enables us to study reliably the first peak in the spectral functions even under the limitations present in the finite temperature setup. We find that $\\chi_{b1}$ survives up to $T=249 {\\rm MeV}$, the highest temperature considered in our study and put stringent constraints on the size of the medium modification of $\\Upsilon$ and $\\chi_{b1}$ states.

Seyong Kim; Peter Petreczky; Alexander Rothkopf

2014-09-12T23:59:59.000Z

152

Nanoscale size dependence parameters on lattice thermal conductivity of Wurtzite GaN nanowires  

SciTech Connect (OSTI)

Graphical abstract: Temperature dependence of calculated lattice thermal conductivity of Wurtzite GaN nanowires. Highlights: Black-Right-Pointing-Pointer A modified Callaway model is used to calculate lattice thermal conductivity of Wurtzite GaN nanowires. Black-Right-Pointing-Pointer A direct method is used to calculate phonon group velocity for these nanowires. Black-Right-Pointing-Pointer 3-Gruneisen parameter, surface roughness, and dislocations are successfully investigated. Black-Right-Pointing-Pointer Dislocation densities are decreases with the decrease of wires diameter. -- Abstract: A detailed calculation of lattice thermal conductivity of freestanding Wurtzite GaN nanowires with diameter ranging from 97 to 160 nm in the temperature range 2-300 K, was performed using a modified Callaway model. Both longitudinal and transverse modes are taken into account explicitly in the model. A method is used to calculate the Debye and phonon group velocities for different nanowire diameters from their related melting points. Effect of Gruneisen parameter, surface roughness, and dislocations as structure dependent parameters are successfully used to correlate the calculated values of lattice thermal conductivity to that of the experimentally measured curves. It was observed that Gruneisen parameter will decrease with decreasing nanowire diameters. Scattering of phonons is assumed to be by nanowire boundaries, imperfections, dislocations, electrons, and other phonons via both normal and Umklapp processes. Phonon confinement and size effects as well as the role of dislocation in limiting thermal conductivity are investigated. At high temperatures and for dislocation densities greater than 10{sup 14} m{sup -2} the lattice thermal conductivity would be limited by dislocation density, but for dislocation densities less than 10{sup 14} m{sup -2}, lattice thermal conductivity would be independent of that.

Mamand, S.M., E-mail: soran.mamand@univsul.net [Department of Physics, College of Science, University of Sulaimani, Sulaimanyah, Iraqi Kurdistan (Iraq); Omar, M.S. [Department of Physics, College of Science, University of Salahaddin, Arbil, Iraqi Kurdistan (Iraq)] [Department of Physics, College of Science, University of Salahaddin, Arbil, Iraqi Kurdistan (Iraq); Muhammad, A.J. [Department of Physics, College of Science, University of Kirkuk, Kirkuk (Iraq)] [Department of Physics, College of Science, University of Kirkuk, Kirkuk (Iraq)

2012-05-15T23:59:59.000Z

153

Anomalous Microfluidic Phonons Induced by the Interplay of Hydrodynamic Screening and Incompressibility  

E-Print Network [OSTI]

Anomalous Microfluidic Phonons Induced by the Interplay of Hydrodynamic Screening the acoustic normal modes (``phonons'') of a 1D microfluidic droplet crystal at the crossover between 2D flow.55.Dÿ, 47.60.+i, 47.63.mf, 63.22.+m Microfluidic two-phase flow offers experimental tools to investigate

Tlusty, Tsvi

154

A first principles pseudopotential in the calculation of the phonon limited resistivity of sodium and potassium  

E-Print Network [OSTI]

of properties of aluminum and lithium. It is obtained from the induced electron density around an ion propriétés de l'aluminium et du lithium. Il s'obtient à partir de la densité électronique induite autour d potential and from this, the phonons to calculate the electron-phonon interaction to predict the resistivity

Boyer, Edmond

155

Raman spectra of out-of-plane phonons in bilayer graphene  

E-Print Network [OSTI]

The double resonance Raman spectra of the overtone of the out-of-plane tangential optical (oTO) phonon and of combinations of the LO, ZO, and ZA phonons with one another are calculated for bilayer graphene. In the case of ...

Sato, Kentaro

156

Effect of temperature on phonon contribution to Green function of high-temperature superconducting cuprates  

SciTech Connect (OSTI)

The phonon contribution to the nodal electron Green function in cuprates is considered. It is shown that the temperature dependence of the real part of the self-energy component of the Green function for cuprates with a hole doping level close to optimal is described by the electron-phonon interaction in the framework of the extended Eliashberg model.

Korneeva, L. A., E-mail: korneeva_mila@mail.ru; Mazur, E. A. [National Research Nuclear University MEPhI (Russian Federation)

2012-08-15T23:59:59.000Z

157

Breathing coherent phonons and caps fragmentation in carbon nanotubes following ultrafast laser pulses  

E-Print Network [OSTI]

driven by ultrafast laser pulses.1­3 The necessary conditions for generating such coherent phonons are i is larger than the duration of currently available ultrafast pulses. ii Measurements4­7 determinedBreathing coherent phonons and caps fragmentation in carbon nanotubes following ultrafast laser

Dumitrica,Traian

158

Commercial Lighting  

Broader source: Energy.gov [DOE]

Commercial lighting accounts for more than 20 percent of total commercial building energy use. The Energy Department works to reduce lighting energy use through research and deployment.

159

Lattice thermal conductivity of filled skutterudites: An anharmonicity perspective  

SciTech Connect (OSTI)

We report a phenomenological model to calculate the high-temperature lattice thermal conductivity of filled skutterudite antimonides. The model needs no phonon resonant scattering terms. Instead, we assume that umklapp processes dominate the high-temperature phonon scattering. In order to represent the anharmonicity introduced by the filling atom, we introduce a Gaussian term into the relaxation time of the umklapp process. The developed model agrees remarkably well with the experimental results of RE{sub f}Co{sub 4}Sb{sub 12} and RE{sub f}Fe{sub 4}Sb{sub 12} (RE?=?Yb, Ba, and Ca) alloys. To further test the validity of our model, we calculate the lattice thermal conductivity of nanostructured or multi-filled skutterudites. The calculation results are also in good agreement with experiment, increasing our confidence in the developed anharmonicity model.

Geng, Huiyuan, E-mail: genghuiyuan@hit.edu.cn; Meng, Xianfu; Zhang, Hao; Zhang, Jian [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

2014-10-28T23:59:59.000Z

160

Carbon Nanotubes: Thermal Properties Columbia University, New York, New York, U.S.A.  

E-Print Network [OSTI]

of the low-energy excitations. In 3-D graphite, 2-D graphene, and nanotubes, phonons are the dominantCarbon Nanotubes: Thermal Properties J. Hone Columbia University, New York, New York, U.S.A. INTRODUCTION As nanoscale graphitic structures, carbon nanotubes are of great interest not only

Hone, James

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161

Evolution of the phonon density of states of LaCoO3 over the spin state transition  

SciTech Connect (OSTI)

The phonon spectra of LaCoO3 were studied by inelastic neutron scattering in the temperature range of 4 120 K. The DFT calculations of the lattice dynamics have been made for interpretation of the experimental data. The observed and calculated phonon frequencies were found to be in a reasonable agreement. The evolution of the phonon density of states over the spin state transition was analyzed. In the low-temperature range (T < 50 K), an increase in the energy of resolved breathing, stretching, and bending phonon modes was found, followed by their softening and broadening at higher temperatures due to the spin state transition and relevant orbital-phonon coupling.

Golosova, N. O. [Joint Institute for Nuclear Research, Dubna, Russia; Kozlenko, D. P. [Joint Institute for Nuclear Research, Dubna, Russia; Kolesnikov, Alexander I [ORNL; Kazimirov, V. Yu. [Joint Institute for Nuclear Research, Dubna, Russia; Smirnov, M. B. [St. Petersburg State University, St. Petersburg, Russia; Jirak, Z. [Institute of Physics, Czech Republic; Savenko, B. N. [Joint Institute for Nuclear Research, Dubna, Russia

2011-01-01T23:59:59.000Z

162

Lattice thermal conductivity of UO{sub 2} using ab-initio and classical molecular dynamics  

SciTech Connect (OSTI)

We applied the non-equilibrium ab-initio molecular dynamics and predict the lattice thermal conductivity of the pristine uranium dioxide for up to 2000?K. We also use the equilibrium classical molecular dynamics and heat-current autocorrelation decay theory to decompose the lattice thermal conductivity into acoustic and optical components. The predicted optical phonon transport is temperature independent and small, while the acoustic component follows the Slack relation and is in good agreement with the limited single-crystal experimental results. Considering the phonon grain-boundary and pore scatterings, the effective lattice thermal conductivity is reduced, and we show it is in general agreement with the sintered-powder experimental results. The charge and photon thermal conductivities are also addressed, and we find small roles for electron, surface polaron, and photon in the defect-free structures and for temperatures below 1500?K.

Kim, Hyoungchul [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136–791 (Korea, Republic of); Kim, Moo Hwan [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kaviany, Massoud, E-mail: kaviany@umich.edu [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2014-03-28T23:59:59.000Z

163

Thermal resistance and phonon scattering at the interface between carbon nanotube and amorphous polyethylene  

E-Print Network [OSTI]

polyethylene Sho Hida a , Takuma Hori a , Takuma Shiga a , James Elliott b , Junichiro Shiomi a,c, a Department dynamics study of heat conduction in carbon nanotube (CNT)/polyethylene (PE) composites. Particular across the CNT/polyethylene interfaces ($1 Ã? 10Ã?7 m2 K WÃ?1 ) and a moder- ate but non

Elliott, James

164

Visible light plasmonic heating of Au-ZnO for the catalytic reduction of CO{sub 2}  

SciTech Connect (OSTI)

Plasmonic excitation of Au nanoparticles attached to the surface of ZnO catalysts using low power 532 nm laser illumination leads to significant heating of the catalyst and the conversion of CO{sub 2} and H{sub 2} reactants to CH{sub 4} and CO products. Temperature-calibrated Raman spectra of ZnO phonons show that intensity-dependent plasmonic excitation can controllably heat Au–ZnO from 30 to #1;~600 {degrees}#3;C and simultaneously tune the CH{sub 4} : CO product ratio. The laser induced heating and resulting CH{sub 4} : CO product distribution agrees well with predictions from thermodynamic models and temperatureprogrammed reaction experiments indicating that the reaction is a thermally driven process resulting from the plasmonic heating of the Au–ZnO. The apparent quantum yield for CO{sub 2} conversion under continuous wave (cw) 532 nm laser illumination is 0.030%. The Au–ZnO catalysts are robust and remain active after repeated laser exposure and cycling. The light intensity required to initiate CO{sub 2} reduction is low (#1;~2.5 x#4; 10{sup 5} W m{sup #5;-2}) and achievable with solar concentrators. Our results illustrate the viability of plasmonic heating approaches for CO{sub 2} utilization and other practical thermal catalytic applications.

Wang, Congjun; Ranasingha, Oshadha; Natesakhawat, Sittichai; Ohodnicki, Paul R.; Ohodnicki, Andio, Mark; Lewis, James; P Matranga, Christopher

2013-05-01T23:59:59.000Z

165

Nonadiabatic phonons within the doped graphene layers of XC6 compounds Mark P. M. Dean,1,* Christopher A. Howard,2 Siddharth S. Saxena,1 and Mark Ellerby2  

E-Print Network [OSTI]

Nonadiabatic phonons within the doped graphene layers of XC6 compounds Mark P. M. Dean,1 a systematic study of the phonons and the electron-phonon interaction within the doped graphene layers of these compounds. The out-of-plane carbon phonon softens as the spacing of the graphene layers is reduced

Sheldon, Nathan D.

166

Piezoelectric surface acoustical phonon amplification in graphene on a GaAs substrate  

SciTech Connect (OSTI)

We study the interaction of Dirac Fermions in monolayer graphene on a GaAs substrate in an applied electric field by the combined action of the extrinsic potential of piezoelectric surface acoustical phonons of GaAs (piezoelectric acoustical (PA)) and of the intrinsic deformation potential of acoustical phonons in graphene (deformation acoustical (DA)). We find that provided the dc field exceeds a threshold value, emission of piezoelectric (PA) and deformation (DA) acoustical phonons can be obtained in a wide frequency range up to terahertz at low and high temperatures. We found that the phonon amplification rate R{sup PA,DA} scales with T{sub BG}{sup S?1} (S=PA,DA), T{sub BG}{sup S} being the Block?Gru{sup ¨}neisen temperature. In the high-T Block?Gru{sup ¨}neisen regime, extrinsic PA phonon scattering is suppressed by intrinsic DA phonon scattering, where the ratio R{sup PA}/R{sup DA} scales with ?1/?(n), n being the carrier concentration. We found that only for carrier concentration n?10{sup 10}cm{sup ?2}, R{sup PA}/R{sup DA}>1. In the low-T Block?Gru{sup ¨}neisen regime, and for n=10{sup 10}cm{sup ?2}, the ratio R{sup PA}/R{sup DA} scales with T{sub BG}{sup DA}/T{sub BG}{sup PA}?7.5 and R{sup PA}/R{sup DA}>1. In this regime, PA phonon dominates the electron scattering and R{sup PA}/R{sup DA}<1 otherwise. This study is relevant to the exploration of the acoustic properties of graphene and to the application of graphene as an acoustical phonon amplifier and a frequency-tunable acoustical phonon device.

Nunes, O. A. C., E-mail: oacn@unb.br [Institute of Physics, University of Brasilia, Brasilia, 70910-900 DF (Brazil)

2014-06-21T23:59:59.000Z

167

Phonon blocking by two dimensional electron gas in polar CdTe/PbTe heterojunctions  

SciTech Connect (OSTI)

Narrow-gap lead telluride crystal is an important thermoelectric and mid-infrared material in which phonon functionality is a critical issue to be explored. In this Letter, efficient phonon blockage by forming a polar CdTe/PbTe heterojunction is explicitly observed by Raman scattering. The unique phonon screening effect can be interpreted by recent discovery of high-density two dimensional electrons at the polar CdTe/PbTe(111) interface which paves a way for design and fabrication of thermoelectric devices.

Zhang, Bingpo; Cai, Chunfeng; Zhu, He; Wu, Feifei; Ye, Zhenyu; Chen, Yongyue; Li, Ruifeng; Kong, Weiguang; Wu, Huizhen, E-mail: hzwu@zju.edu.cn [Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, Zhejiang 310027 (China)

2014-04-21T23:59:59.000Z

168

Phonon densities of states of face-centered-cubic Ni-Fe alloys  

SciTech Connect (OSTI)

Inelastic neutron scattering and nuclear resonant inelastic x-ray scattering were used to determine the phonon densities of states of face-centered-cubic Ni-Fe alloys. Increasing Fe concentration results in an average softening of the phonon modes. Chemical ordering of the Ni0.72Fe0.28 alloy results in a reduction of the partial vibrational entropy of the Fe atoms but does not significantly change the partial vibrational entropy of the Ni atoms. Changes in the phonon densities of states with composition and chemical ordering are discussed and analyzed with a cluster expansion method.

Lucas, Matthew [United States Air Force Research Laboratory, Wright-Patterson Air Force Base] [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Mauger, L [California Institute of Technology, W. M. Keck Laboratory, Pasadena] [California Institute of Technology, W. M. Keck Laboratory, Pasadena; Munoz, Jorge A. [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena; Halevy, I [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena; Horwath, J [United States Air Force Research Laboratory, Wright-Patterson Air Force Base] [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Semiatin, S L [United States Air Force Research Laboratory, Wright-Patterson Air Force Base] [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Leontsev, S. O. [University of Kentucky, Lexington] [University of Kentucky, Lexington; Stone, Matthew B [ORNL] [ORNL; Abernathy, Douglas L [ORNL] [ORNL; Xiao, Yuming [Carnegie Institution of Washington] [Carnegie Institution of Washington; Chow, P [HPCAT Geophysical Lab, Argonne, IL] [HPCAT Geophysical Lab, Argonne, IL; Fultz, B. [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena

2013-01-01T23:59:59.000Z

169

Influence of electron–phonon interactions in single dopant nanowire transistors  

SciTech Connect (OSTI)

Single dopant nanowire transistors can be viewed as the ultimate miniaturization of nano electronic devices. In this work, we theoretically investigate the influence of the electron-phonon coupling on their transport properties using a non-equilibrium Green's function approach in the self-consistent Born approximation. For an impurity located at the center of the wire we find that, at room temperature, acoustic phonons broaden the impurity level so that the bistability predicted in the ballistic regime is suppressed. Optical phonons are found to have a beneficial impact on carrier transport via a phonon-assisted tunneling effect. We discuss the position and temperature dependence of these effects, showing that such systems might be very promising for engineering of ultimate devices.

Carrillo-Nuñez, H., E-mail: carrillh@iis.ee.ethz.ch; Bescond, M., E-mail: marc.bescond@im2np.fr; Cavassilas, N.; Dib, E.; Lannoo, M. [IM2NP, UMR CNRS 6242, Bât. IRPHE, Technopôle de Château-Gombert, 13384 Marseille, Cedex 13 (France)

2014-10-28T23:59:59.000Z

170

Effects of Electron-Phonon Coupling in Single-Molecule Magnet...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electron-Phonon Coupling in Single-Molecule Magnet Transport Junctions Using a Hybrid Density Functional Theory and Model Hamiltonian Approach Apr 04 2014 10:00 AM - 11:00 AM Alex...

171

Heart-shaped nuclei: Condensation of rotational-aligned octupole phonons  

SciTech Connect (OSTI)

The strong octupole correlations in the mass region A{approx_equal}226 are interpreted as rotation-induced condensation of octupole phonons having their angular momentum aligned with the rotational axis. Discrete phonon energy and parity conservation generate oscillations of the energy difference between the lowest rotational bands with positive and negative parity. Anharmonicities tend to synchronize the rotation of the condensate and the quadrupole shape of the nucleus forming a rotating heart shape.

Frauendorf, S. [ISP, Forschungszentrum Dresden-Rossendorf, Dresden, Germany (Germany); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2008-02-15T23:59:59.000Z

172

Parity conservation in electron-phonon scattering in zigzag graphene nanoribbon  

SciTech Connect (OSTI)

In contrast with carbon nanotubes, the absence of translational symmetry (or periodical boundary condition) in the restricted direction of zigzag graphene nanoribbon removes the selection rule of subband number conservation. However, zigzag graphene nanoribbons with even dimers do have the inversion symmetry. We, therefore, propose a selection rule of parity conservation for electron-phonon interactions. The electron-phonon scattering matrix in zigzag graphene nanoribbons is developed using the tight-binging model within the deformation potential approximation.

Chu, Yanbiao; Gautreau, Pierre; Basaran, Cemal, E-mail: cjb@buffalo.edu [Electronic Packaging Laboratory, University at Buffalo, SUNY, Buffalo, New York 14260 (United States)

2014-09-15T23:59:59.000Z

173

Smart Lighting Controller!! Smart lighting!  

E-Print Network [OSTI]

1! Smart Lighting Controller!! #12;2! Smart lighting! No need to spend energy lighting the room if://blogs.stthomas.edu/realestate/2011/01/24/residential-real-estate-professionals-how-do-you- develop feedback! There is a connection between the output and the input! Therefore forces inputs to same voltage

Anderson, Betty Lise

174

Effects of ternary mixed crystal and size on optical phonons in wurtzite nitride core-shell nanowires  

SciTech Connect (OSTI)

Within the framework of dielectric continuum and Loudon's uniaxial crystal models, existence conditions dependent on components and frequencies for optical phonons in wurtzite nitride core-shell nanowires (CSNWs) are discussed to obtain dispersion relations and electrostatic potentials of optical phonons in In{sub x}Ga{sub 1?x}N/GaN CSNWs. The results show that there may be four types of optical phonons in In{sub x}Ga{sub 1?x}N/GaN CSNWs for a given ternary mixed crystal (TMC) component due to the phonon dispersion anisotropy. This property is analogous to wurtzite planar heterojunctions. Among the optical phonons, there are two types of quasi-confined optical (QCO) phonons (named, respectively, as QCO-A and QCO-B), one type of interface (IF) phonons and propagating (PR) phonons existing in certain component and frequency domains while the dispersion relations and electrostatic potentials of same type of optical phonons vary with components. Furthermore, the size effect on optical phonons in CSNWs is also discussed. The dispersion relations of IF and QCO-A are independent of the boundary location of CSNWs. Meanwhile, dispersion relations and electrostatic potentials of QCO-B and PR phonons vary obviously with size, especially, when the ratio of a core radius to a shell radius is small, and dispersion relation curves of PR phonons appear to be close to each other, whereas, this phenomenon disappears when the ratio becomes large. Based on our conclusions, one can further discuss photoelectric properties in nitride CSNWs consisting of TMCs associated with optical phonons.

Li, J.; Guan, J. Y.; Zhang, S. F.; Ban, S. L.; Qu, Y., E-mail: quyuan@imu.edu.cn [School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021 (China)

2014-04-21T23:59:59.000Z

175

Commercial Lighting and LED Lighting Incentives  

Broader source: Energy.gov [DOE]

Incentives for energy efficient commercial lighting equipment as well as commercial LED lighting equipment are available to businesses under the Efficiency Vermont Lighting and LED Lighting...

176

Lighting Renovations  

Broader source: Energy.gov [DOE]

When undertaking a lighting renovation in a Federal building, daylighting is the primary renewable energy opportunity. Photovoltaics (PV) also present an excellent opportunity. While this guide...

177

Cerenkov Light  

ScienceCinema (OSTI)

The bright blue glow from nuclear reactors is Cerenkov light. Karl Slifer describes how nuclear physicists can use this phenomenon to study the nucleus of the atom.

Slifer, Karl

2014-05-22T23:59:59.000Z

178

Cerenkov Light  

SciTech Connect (OSTI)

The bright blue glow from nuclear reactors is Cerenkov light. Karl Slifer describes how nuclear physicists can use this phenomenon to study the nucleus of the atom.

Slifer, Karl

2013-06-13T23:59:59.000Z

179

Study on generating of thermal neutron scattering cross sections for LiH  

SciTech Connect (OSTI)

LiH is designated as a promising moderator and shielding material because of its low density, high melting point and large fraction of H atoms. However, lack of the thermal neutron cross sections of LiH makes numerical calculation deviate from experimental data to some extent. As a result, it is necessary to study LiH thermal kernel effect. The phonon property of LiH has been investigated by first-principles calculations using the plane-wave pseudo potential method with CASTEP code. The scattering law and the thermal neutron scattering cross sections for Li and H have been generated using this distribution. The results have been compared with zirconium hydride data. The GASKET and NJOY/LEAPR codes have been used in the calculation of scattering law, whose results have been compared with the reference; the discrepancy mainly comes from phonon spectrums and its expansion. LEAPR had the capability to compute scattering through larger energy and momentum transfers than GASKET did. By studying LiH phonon spectrum and constructing the model of LiH thermal kernel and scattering matrix, the ACE format LiH thermal neutron cross sections for MCNP software could be made and used for reactor Neutronics calculation. (authors)

Wang, L.; Jiang, X.; Zhao, Z.; Chen, L. [Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

2013-07-01T23:59:59.000Z

180

Integrated LED-based luminare for general lighting  

DOE Patents [OSTI]

Lighting apparatus and methods employing LED light sources are described. The LED light sources are integrated with other components in the form of a luminaire or other general purpose lighting structure. Some of the lighting structures are formed as Parabolic Aluminum Reflector (PAR) luminaires, allowing them to be inserted into conventional sockets. The lighting structures display beneficial operating characteristics, such as efficient operation, high thermal dissipation, high output, and good color mixing.

Dowling, Kevin J.; Lys, Ihor A.; Roberge, Brian; Williamson, Ryan C.; Roberts, Ron; Datta, Michael; Mollnow, Tomas; Morgan, Frederick M.

2013-03-05T23:59:59.000Z

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Background-subtraction using contour-based fusion of thermal and visible imagery  

E-Print Network [OSTI]

rights reserved. Keywords: Background-subtraction; Fusion; Thermal imagery; Infrared; FLIR; Contour of the electromagnetic spectrum, long-wave infrared (thermal) and visible light. Thermal (FLIR) and color video cameras

Davis, James W.

182

Light Matters (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)  

ScienceCinema (OSTI)

'Light Matters' was submitted by the Center for Light-Material Interactions in Energy Conversion (LMI) to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. This video was selected as one of five winners by a distinguished panel of judges for its 'striking photography and visual impact'. LMI, an EFRC directed by Harry Atwater at the California Institute of Technology is a partnership of scientists from three institutions: CalTech (lead), University of California, Berkeley, and the University of Illinois at Urbana-Champaign. The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of Light-Material Interactions in Energy Conversion is 'to tailor the morphology, complex dielectric structure, and electronic properties of matter to sculpt the flow of sunlight, enabling light conversion to electrical and chemical energy with unprecedented efficiency.' Research topics are: catalysis (imines hydrocarbons), solar photovoltaic, solar fuels, photonic, solid state lighting, metamaterial, optics, phonons, thermal conductivity, solar electrodes, photsynthesis, CO{sub 2} (convert), greenhouse gas, and matter by design.

Atwater, Harry (Director, Light-Material Interactions in Energy Conversion (LMI), California Institute of Technology); LMI Staff

2011-11-02T23:59:59.000Z

183

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

SciTech Connect (OSTI)

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

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

2008-08-15T23:59:59.000Z

184

Electric thermal storage demonstration program  

SciTech Connect (OSTI)

In early 1989, MMWEC, a joint action agency comprised of 30 municipal light departments in Massachusetts and one affiliate in Rhode Island, responded to a Department of Energy request to proposal for the Least Cost Utility Planning program. The MMWEC submission was for the development of a program, focused on small rural electric utilities, to promote the use of electric thermal storage heating systems in residential applications. In this progress report, cost savings at Bolyston light department is discussed. (JL)

Not Available

1992-02-01T23:59:59.000Z

185

Electric thermal storage demonstration program  

SciTech Connect (OSTI)

In early 1989, MMWEC, a joint action agency comprised of 30 municipal light departments in Massachusetts and one affiliate in Rhode Island, responded to a Department of Energy request to proposal for the Least Cost Utility Planning program. The MMWEC submission was for the development of a program, focused on small rural electric utilities, to promote the use of electric thermal storage heating systems in residential applications. In this progress report, cost savings at Bolyston light department is discussed. (JL)

Not Available

1992-01-01T23:59:59.000Z

186

Graphene optical-to-thermal converter  

E-Print Network [OSTI]

Infrared plasmons in doped graphene nanostructures produce large optical absorption that can be used for narrow-band thermal light emission at tunable frequencies that strongly depend on the doping charge. By virtue of Kirchhoff's law, thermal light emission is proportional to the absorption, thus resulting in narrow emission lines associated with the electrically controlled plasmons of heated graphene. Here we show that realistic designs of graphene plasmonic structures can release over 90% of the emission through individual infrared lines with 1% bandwidth. We examine anisotropic graphene structures in which efficient heating can be produced upon optical pumping tuned to a plasmonic absorption resonance situated in the blue region relative to the thermal emission. An incoherent thermal light converter is thus achieved. Our results open a radically different approach for designing tunable nanoscale infrared light sources.

Manjavacas, Alejandro; Greffet, Jean-Jacques; de Abajo, F Javier García

2014-01-01T23:59:59.000Z

187

Phonon characteristics of high {Tc} superconductors from neutron Doppler broadening measurements  

SciTech Connect (OSTI)

Statistical information on the phonon frequency spectrum of materials can be measured by neutron transmission techniques if they contain nuclei with low energy resonances, narrow enough to be Doppler-broadened, in their neutron cross sections. The authors have carried out some measurements using this technique for materials of the lanthanum barium cuprate class, La{sub 2{minus}x}Ba{sub x}CuO{sub 4}. Two samples with slightly different concentrations of oxygen, one being superconductive, the other not, were examined. Pure lanthanum cuprate was also measured. Lanthanum, barium and copper all have relatively low energy narrow resonances. Thus it should be possible to detect differences in the phonons carried by different kinds of atom in the lattice. Neutron cross section measurements have been made with high energy resolution and statistical precision on the 59m flight path of LANSCE, the pulsed spallation neutron source at Los Alamos National Laboratory. Measurements on all three materials were made over a range of temperatures from 15K to 300K, with small steps through the critical temperature region near 27K. No significant changes in the mean phonon energy of the lanthanum atoms were observed near the critical temperature of the super-conducting material. It appears however that the mean phonon energy of lanthanum in the superconductor is considerably higher than that in the non-superconductors. The samples used in this series of experiments were too thin in barium and copper to determine anything significant about their phonon spectra.

Trela, W.J.; Kwei, G.H.; Lynn, J.E. [Los Alamos National Lab., NM (United States); Meggers, K. [Univ. of Kiel (Germany)

1994-12-01T23:59:59.000Z

188

Net electron-phonon scattering rates in InN/GaN multiple quantum wells: The effects of an energy dependent acoustic deformation potential  

SciTech Connect (OSTI)

The rates of charge carrier relaxation by phonon emission are of substantial importance in the field of hot carrier solar cell, primarily in investigation of mechanisms to slow down hot carrier cooling. In this work, energy and momentum resolved deformation potentials relevant to electron-phonon scattering are computed for wurtzite InN and GaN as well as an InN/GaN multiple quantum well (MQW) superlattice using ab-initio methods. These deformation potentials reveal important features such as discontinuities across the electronic bandgap of the materials and variations over tens of eV. The energy dependence of the deformation potential is found to be very similar for wurtzite nitrides despite differences between the In and Ga pseudopotentials and their corresponding electronic band structures. Charge carrier relaxation by this mechanism is expected to be minimal for electrons within a few eV of the conduction band edge. However, hole scattering at energies more accessible to excitation by solar radiation is possible between heavy and light hole states. Moderate reductions in overall scattering rates are observed in MQW relative to the bulk nitride materials.

Xia, H., E-mail: h.xia@unsw.edu.au; Patterson, R.; Feng, Y.; Shrestha, S.; Conibeer, G. [School of Photovoltaics and Renewable Energy Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia)

2014-08-11T23:59:59.000Z

189

The graphene phonon dispersion with C{sup 12} and C{sup 13} isotopes  

SciTech Connect (OSTI)

Using very uniform large scale chemical vapor deposition grown graphene transferred onto silicon, we were able to identify 15 distinct Raman lines associated with graphene monolayers. This was possible thanks to a combination of different carbon isotopes and different Raman laser energies and extensive averaging without increasing the laser power. This allowed us to obtain a detailed experimental phonon dispersion relation for many points in the Brillouin zone. We further identified a D+D' peak corresponding to a double phonon process involving both an inter- and intra-valley phonon. In order to both eliminate substrate effects and to probe large areas, we undertook to study Raman scattering for large scale chemical vapor deposition (CVD) grown graphene using two different isotopes (C12 and C13) so that we can effectively exclude and subtract the substrate contributions, since a heavier mass downshifts only the vibrational properties, while keeping all other properties the same.

Whiteway, Eric; Bernard, Simon; Yu, Victor; Hilke, Michael [Department of Physics, McGill University, Montréal H3A 2T8 (Canada); Austing, D. Guy [National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

2013-12-04T23:59:59.000Z

190

Room-temperature condensation in whispering gallery microresonators assisted by longitudinal optical phonons  

E-Print Network [OSTI]

We report condensation of hexagonal whispering gallery modes (WGM) at room temperature in ZnO microwires that embody nearly perfect polygonal whispering gallery microresonators. The condensate regime is achieved in the UV spectral range only at energies below the first longitudinal optical (LO) phonon replica of the free ZnO A-exciton transition and at non-zero wave vectors. We demonstrate that the multimodality of the WGM system and the high population of free excitons and phonons with various momenta strongly enhance the probability of an interaction of quasiparticles of the cavity exciton-photon system with LO phonons. We further examine the far-field mode pattern of lasing WGM and demonstrate their spatial coherence.

Dietrich, Christof P; Michalsky, Tom; Lange, Martin; Grundmann, Marius

2015-01-01T23:59:59.000Z

191

PHYSICAL REVIEW B 86, 045413 (2012) Cooling of photoexcited carriers in graphene by internal and substrate phonons  

E-Print Network [OSTI]

for cooling of photoexcited carriers in graphene via the remote surface polar phonon modes (SPPPHYSICAL REVIEW B 86, 045413 (2012) Cooling of photoexcited carriers in graphene by internal through coupling to both intrinsic and remote (substrate) surface polar phonons using the Boltzmann

Perebeinos, Vasili

192

Strong Suppression of Electronic Coherence Time by Flexural Phonons in Graphene --- Example of a New Dephasing Mechanism  

E-Print Network [OSTI]

We investigate decoherence of an electron in graphene caused by electron-flexural phonon interaction.We find out that the flexural phonons can produce dephasing rate comparable to the electron-electron one. The problem appears to be quite special...

Zhao, Wei

2014-07-08T23:59:59.000Z

193

Quantum phase transition in the Frenkel-Kontorova chain: From pinned instanton glass to sliding phonon gas  

E-Print Network [OSTI]

glass is transformed into the sliding phonon gas with gapless phonon excitations. This transition materials 5­7 , and, more re- cently, to charge-density waves 8 and dry friction 9,10 . Despite the fact Aubry discovered 6 a new type of ground state that has fractal properties known as ``devil's staircase

Shepelyansky, Dima

194

Electromagnetically induced transparency from two-phonon processes in quadratically coupled membranes  

SciTech Connect (OSTI)

We describe how electromagnetically induced transparency can arise in quadratically coupled optomechanical systems. Due to quadratic coupling, the underlying optical process involves a two-phonon process in an optomechanical system, and this two-phonon process makes the mean displacement, which plays the role of atomic coherence in traditional electromagnetically induced transparency (EIT), zero. We show how the fluctuation in displacement can play a role similar to atomic coherence and can lead to EIT-like effects in quadratically coupled optomechanical systems. We show how such effects can be studied using the existing optomechanical systems.

Huang, Sumei; Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

2011-02-15T23:59:59.000Z

195

Effect of electron-phonon interaction on resistivity of some heavy fermion (HF) systems  

SciTech Connect (OSTI)

Here, we have analyzed the electron-phonon interaction in the Periodic Anderson Model (PAM) to describe the temperature dependence of resistivity in some heavy fermion (HF) systems for finite wave vector (q) and for finite temperature (T). Since the resistivity is related to the imaginary part of the electron self energy, the expression for the same is evaluated through double time temperature dependant Green function technique of the Zubarev type. The effect of different system parameters namely the position of 4f level, E{sub 0} and the electron - phonon coupling strengths on resistivity have been studied. The results obtained give satisfactory explanations to the experimental observations.

Sahoo, J., E-mail: jitendrasahoo2008@gmail.com [Assistant Director, Regional Office of Vocational Education, Sambalpur, Odisha-768004 (India); Shadangi, N. [Dept. of Physics, Silicon Institute of Technology, Sambalpur, Odisha-768200 (India); Nayak, P. [School of Physics, Sambalpur University, Sambalpur, Odisha-768019 (India)

2014-04-24T23:59:59.000Z

196

Mode Coupling of Phonons in a Dense One-Dimensional Microfluidic Crystal  

E-Print Network [OSTI]

Long-living coupled transverse and longitudinal phonon modes are explored in dense and regular arrangements of flat microfluidic droplets. The collective oscillations are driven by hydrodynamic interactions between the confined droplets and can be excited in a controlled way. Experimental results are quantitatively compared to simulation results obtained by multi-particle collision dynamics. The observed transverse modes are acoustic phonons and can be described by a linearized far-field theory, whereas the longitudinal modes arise from a non-linear mode coupling due to the lateral variation of the flow field under confinement.

Jean-Baptiste Fleury; Ulf D Schiller; Shashi Thutupalli; Gerhard Gompper; Ralf Seemann

2013-10-14T23:59:59.000Z

197

The Effect of Nanoparticles on Thermal Conductivity of Nanocomposite Thin Films at Low Temperatures  

E-Print Network [OSTI]

Generalized equation of phonon radiative transport”. Appliedtransport cross section to solve the generalized equation for phonon radiative

Katika, Kamal M.; Pilon, Laurent

2008-01-01T23:59:59.000Z

198

Lattice thermal conductivity of nanograined half-Heusler solid solutions  

SciTech Connect (OSTI)

We report a phenomenological model of atomic weight, lattice constant, temperature, and grain size to calculate the high-temperature lattice thermal conductivity of nanograined solid solutions. The theoretical treatment developed here is reasonably consistent with the experimental results of n-type MNiSn and p-type MCoSb alloys, where M is the combination of Hf, Zr, and Ti. For disordered half-Heusler alloys with moderated grain sizes, we predict that the reduction in lattice thermal conductivity due to grain boundary scattering is independent of the scattering parameter, which characterizes the phonon scattering cross section of point defects. In addition, the lattice thermal conductivity falls off with temperature as T{sup –1?2} around the Debye temperature.

Geng, Huiyuan, E-mail: genghuiyuan@hit.edu.cn; Meng, Xianfu; Zhang, Hao; Zhang, Jian [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

2014-05-19T23:59:59.000Z

199

Light Computing  

E-Print Network [OSTI]

A configuration of light pulses is generated, together with emitters and receptors, that allows computing. The computing is extraordinarily high in number of flops per second, exceeding the capability of a quantum computer for a given size and coherence region. The emitters and receptors are based on the quantum diode, which can emit and detect individual photons with high accuracy.

Gordon Chalmers

2006-10-13T23:59:59.000Z

200

ENHANCEMENT OF SUPERCONDUCTING Tc IN Pd-H LIKE COMPOUNDS BY OPTICAL PHONONS  

E-Print Network [OSTI]

1227 ENHANCEMENT OF SUPERCONDUCTING Tc IN Pd-H LIKE COMPOUNDS BY OPTICAL PHONONS J. P. BURGER and D.450 1. Introduction. - The high superconducting tran- sition temperatures recently observed in Pd [1 interaction inhibiting superconductivity in pure Pd. As the density of states in Pd-H is rather similar [5

Boyer, Edmond

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Carrier recombination and generation rates for intravalley and intervalley phonon scattering in graphene  

E-Print Network [OSTI]

in graphene Farhan Rana,* Paul A. George, Jared H. Strait, Jahan Dawlaty, Shriram Shivaraman, Mvs and recombination rates for intravalley and intervalley phonon scattering in graphene are presented. The transverse carriers in graphene. DOI: 10.1103/PhysRevB.79.115447 PACS number s : 73.63.Bd, 73.50.Gr, 72.10.Di, 73

Afshari, Ehsan

202

Ab initio studies of electron-phonon coupling in single-walled nanotubes  

E-Print Network [OSTI]

Ab initio studies of electron-phonon coupling in single-walled nanotubes M. Machón , S. Reich , J in single-walled nanotubes and graphene. The perturbation of the electronic energies due to the atomic mode show different behaviours for armchair and zig-zag nanotubes. Raman spectroscopy is a powerful

Nabben, Reinhard

203

High-Energy Phonon Branches of an Individual Metallic Carbon Nanotube J. Maultzsch,1  

E-Print Network [OSTI]

High-Energy Phonon Branches of an Individual Metallic Carbon Nanotube J. Maultzsch,1 S. Reich,1 U, 70569 Stuttgart, Germany (Received 13 December 2002; published 19 August 2003) We present excitation-energy dependent Raman measurements between 2.05 and 2.41 eVon the same individual carbon nanotube. We find

Nabben, Reinhard

204

Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau  

E-Print Network [OSTI]

Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau-sud Campus Polytechnique RD 128 91127 Palaiseau cedex, France Heat transfer between two plates of polar far-field value. In this article, we show that nanoscale heat transfer is dominated by the coupling

Paris-Sud XI, Université de

205

Optical phonons and the soft mode in 2H-NbSe2  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We present an investigation of the lattice dynamics of the charge density wave (CDW) compound 2H-NbSe2. We analyze the precise nature of the wave vector-dependent electron-phonon coupling (EPC) and derive the bare dispersion of the CDW soft phonon mode using inelastic x-ray scattering combined with ab initio calculations. Experimentally, phonon modes along the ??M line, i.e., q = (h,0,0), with 0 ? h ? 0.5 and the same longitudinal symmetry (?1) as the CDW soft mode, were investigated up to 32 meV. In agreement with our calculations, we observe significant EPC in the optic modes at h ? 0.2. We analyze the EPC in the optic, as well as acoustic, mode and show that the q dependences stem from scattering processes between two bands at the Fermi surface that both have a Nb 4d character. Finally, we demonstrate that the soft mode dispersion at T = 33 K (=TCDW) can be well described on the basis of a strongly q-dependent EPC matrix element and an acousticlike bare phonon dispersion in agreement with observations near room temperature.

Weber, F.; Hott, R.; Heid, R.; Bohnen, K.-P.; Rosenkranz, S.; Castellan, J.-P.; Osborn, R.; Said, A. H.; Leu, B. M.; Reznik, D.

2013-06-01T23:59:59.000Z

206

The Jahn?Teller effect and electron?phonon ... (J. Phys.: Condens...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

S0953-8984(01)21276-4 The Jahn-Teller effect and electron-phonon interaction in La 0.25 Ca 0.75 Mn 1-x Cr x O 3 H-D Zhou, G Li, H Chen, R-K Zheng, X-J Fan and X-G Li Structure...

207

Development of phonon-polarization THz spectroscopy, and the investigation of relaxor ferroelectrics  

E-Print Network [OSTI]

This thesis develops phonon-polariton based THz spectroscopy and uses this technique to make the first THz frequency dielectric measurements of a relaxor ferroelectric crystal, in particular KTao0.982Nb0.018O3 (KTN 1.8). ...

Paxton, Benjamin John

2006-01-01T23:59:59.000Z

208

Magneto-optical conductivity in graphene including electron-phonon coupling Adam Pound1  

E-Print Network [OSTI]

8S 4M1 3 The Canadian Institute for Advanced Research, Toronto, Ontario, Canada, M5G 1Z8 and 4 of spectral weight in each Landau level (LL) into phonon-assisted peaks in the spectral function. Other new, upright cone forming the conduction band and the lower, inverted cone forming the valence band

Ahlers, Guenter

209

Acoustic-phonon propagation in rectangular semiconductor nanowires with elastically dissimilar barriers  

E-Print Network [OSTI]

Engineering, University of California--Riverside, Riverside, California 92521, USA Received 15 February 2005 dissimilar materials. As example systems, we have considered GaN nanowires with AlN and plastic barrier­5 The modification of the acoustic phonon dispersion in semiconductor superlattices has been mostly studied, both

210

Resonance laser-plasma excitation of coherent terahertz phonons in the bulk of fluorine-bearing crystals under high-intensity femtosecond laser irradiation  

SciTech Connect (OSTI)

The dynamics of coherent phonons in fluorine-containing crystals was investigated by pump-probe technique in the plasma production regime. Several phonon modes, whose frequencies are overtones of the 0.38-THz fundamental frequency, were simultaneously observed in a lithium fluoride crystal. Phonons with frequencies of 1 and 0.1 THz were discovered in a calcium fluoride crystal and coherent phonons with frequencies of 1 THz and 67 GHz were observed in a barium fluoride crystal. Furthermore, in the latter case the amplitudes of phonon mode oscillations were found to significantly increase 15 ps after laser irradiation. (interaction of laser radiation with matter)

Potemkin, F V; Mareev, E I [International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Khodakovskii, N G [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Mikheev, P M

2013-08-31T23:59:59.000Z

211

Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen  

DOE Patents [OSTI]

A process is described for selective thermal oxidation or photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts. 19 figs.

Frei, H.; Blatter, F.; Sun, H.

1999-06-22T23:59:59.000Z

212

Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen  

DOE Patents [OSTI]

A process for selective thermal oxidation or photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

Frei, Heinz (Berkeley, CA); Blatter, Fritz (Basel, CH); Sun, Hai (Saint Charles, MO)

1999-01-01T23:59:59.000Z

213

Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen  

DOE Patents [OSTI]

A process for a combined selective thermal oxidation and photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly combined selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

Frei, Heinz (Berkeley, CA); Blatter, Fritz (Basel, CH); Sun, Hai (Saint Charles, MO)

2001-01-01T23:59:59.000Z

214

JOURNAL DE PHYSIQUE Colloque C4, supplkment au no 10, Octobre 1972, page C4-119 HEAT PULSE INTERACTION  

E-Print Network [OSTI]

made of the 3 phonon normal process scattering rate in dielectric solids from thermal conductivity data between available phonon states in a three vap = Q(ua,p- ~p,a)- (6) phonon normal process and is Article floride is considered in the light of these results. Introduction. - Several measurements [I] have been

Boyer, Edmond

215

Electron/phonon coupling in group-IV transition-metal and rare-earth nitrides  

SciTech Connect (OSTI)

Transport electron/phonon coupling parameters and Eliashberg spectral functions ?{sub tr}{sup 2}F(??) are determined for group-IV transition-metal (TM) nitrides TiN, ZrN, and HfN, and the rare-earth (RE) nitride CeN using an inversion procedure based upon temperature-dependent (4 < T < 300 K) resistivity measurements of high-crystalline-quality stoichiometric epitaxial films grown on MgO(001) by magnetically-unbalanced reactive magnetron sputtering. Transport electron/phonon coupling parameters ?{sub tr} vary from 1.11 for ZrN to 0.82 for HfN, 0.73 for TiN, and 0.44 for CeN. The small variation in ?{sub tr} among the TM nitrides and the weak coupling in CeN are consistent with measured superconducting transition temperatures 10.4 (ZrN), 9.18 (HfN), 5.35 (TiN), and <4 K for CeN. The Eliashberg spectral function describes the strength and energy spectrum of electron/phonon coupling in conventional superconductors. Spectral peaks in ?{sup 2}F(??), corresponding to regions in energy-space for which electrons couple to acoustic ??{sub ac} and optical ??{sub op} phonon modes, are centered at ??{sub ac} = 33 and ??{sub op} = 57 meV for TiN, 25 and 60 meV for ZrN, 18 and 64 meV for HfN, and 21 and 39 meV for CeN. The acoustic modes soften with increasing cation mass; optical mode energies remain approximately constant for the TM nitrides, but are significantly lower for the RE nitride due to a lower interatomic force constant. Optical/acoustic peak-intensity ratios are 1.15 ± 0.1 for all four nitrides, indicating similar electron/phonon coupling strengths ?{sub tr}(??) for both modes.

Mei, A. B.; Rockett, A. [Departments of Materials Science, Physics, and the Materials Research Laboratory, University of Illinois, 104 South Goodwin, Urbana, Illinois 61801 (United States)] [Departments of Materials Science, Physics, and the Materials Research Laboratory, University of Illinois, 104 South Goodwin, Urbana, Illinois 61801 (United States); Hultman, L. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-58183 Linköping (Sweden)] [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-58183 Linköping (Sweden); Petrov, I.; Greene, J. E. [Departments of Materials Science, Physics, and the Materials Research Laboratory, University of Illinois, 104 South Goodwin, Urbana, Illinois 61801 (United States) [Departments of Materials Science, Physics, and the Materials Research Laboratory, University of Illinois, 104 South Goodwin, Urbana, Illinois 61801 (United States); Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-58183 Linköping (Sweden)

2013-11-21T23:59:59.000Z

216

Lighting Inventory Lighting Theatre and Drama  

E-Print Network [OSTI]

Lighting Inventory Lighting Theatre and Drama Description Totals R.Halls Wells- Metz Light ERS ETC SourceFour 25 25 50 degree ERS Strand Lighting 64 14 24 12 14 36 degree ERS ETC Source Four 15 15 36 degree ERS Strand Lighting 124 60 58 2 4 26 degree ERS ETC SourceFour 2 2 26 degree ERS Strand

Indiana University

217

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network [OSTI]

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

Tsang, C.-F.

2011-01-01T23:59:59.000Z

218

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

219

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

220

Light Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011 LawrenceEfeedstocks and the climateLife a Light

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Light' Darkness  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011 LawrenceEfeedstocks and the climateLifeLight to

222

Residential Lighting  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared atEffectquestionnairesU.S. EnergyEnergy EfficiencyLighting

223

Phonon self-energy and origin of anomalous neutron scattering spectra in SnTe and PbTe thermoelectrics  

SciTech Connect (OSTI)

The anharmonic lattice dynamics of rock-salt thermoelectric compounds SnTe and PbTe are investigated with inelastic neutron scattering (INS) and first-principles calculations. The experiments show that, surprisingly, although SnTe is closer to the ferroelectric instability, phonon spectra in PbTe exhibit a more anharmonic character. This behavior is reproduced in first-principles calculations of the temperature-dependent phonon self-energy. Our simulations reveal how the nesting of phonon dispersions induces prominent features in the self-energy, which account for the measured INS spectra and their temperature dependence. We establish that the phase-space for three-phonon scattering processes, rather than just the proximity to the lattice instability, is the mechanism determining the complex spectrum of the transverse-optical ferroelectric mode.

Li, Chen [ORNL] [ORNL; Ma, Jie [ORNL] [ORNL; May, Andrew F [ORNL] [ORNL; Cao, Huibo [ORNL] [ORNL; Christianson, Andrew D [ORNL] [ORNL; Ehlers, Georg [ORNL] [ORNL; Singh, David J [ORNL] [ORNL; Sales, Brian C [ORNL] [ORNL; Delaire, Olivier A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

224

Light Water Reactor Sustainability  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 Light Water Reactor Sustainability Program ACCOMPLISHMENTS REPORT 2013 Accomplishments Report | Light Water Reactor Sustainability 2 T he mission of the Light Water Reactor...

225

Light Water Reactor Sustainability  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

4 Light Water Reactor Sustainability ACCOMPLISHMENTS REPORT 2014 Accomplishments Report | Light Water Reactor Sustainability 2 T he mission of the Light Water Reactor...

226

Metallic halide lights and lighting systems. (Latest citations from the US Patent Bibliographic file with exemplary claims). Published Search  

SciTech Connect (OSTI)

The bibliography contains citations of selected patents concerning the design and operation of metallic halide lights and lighting systems. High pressure, high intensity, and low wattage discharge lamps are described. Citations discuss power sources, lamp life, lamp control circuits, thermal switches, and heat reflective coatings. Applications in sport stadium lighting, vehicle headlights, and crop-lighting are included. (Contains a minimum of 170 citations and includes a subject term index and title list.)

Not Available

1994-11-01T23:59:59.000Z

227

Observation of phononic helical edge states in a mechanical 'topological insulator'  

E-Print Network [OSTI]

A topological insulator is characterized by a dichotomy between the interior and the edge of a finite system: While the bulk has a non-zero energy gap, the edges are forced to sustain excitations traversing these gaps. Originally proposed for electrons governed by quantum mechanics, it has remained an important open question if the same physics can be observed for systems obeying Newton's equations of motion. Here, we report on measurements that characterize the collective behavior of mechanical oscillators exhibiting the phenomenology of the quantum spin hall effect. The phononic edge modes are shown to be helical and we demonstrate their topological protection via the stability against imperfections. Our results open the door to the design of topological acoustic meta-materials that can capitalize on the stability of the surfaces phonons as reliable wave guides.

Süsstrunk, Roman

2015-01-01T23:59:59.000Z

228

Exciton-phonon information flow in the energy transfer process of photosynthetic complexes  

E-Print Network [OSTI]

Non-Markovian and non-equilibrium phonon effects are believed to be key ingredients in the energy transfer in photosynthetic complexes, especially in complexes which exhibit a regime of intermediate exciton-phonon coupling. In this work, we harness a recently developed measure for non-Markovianity to elucidate the information flow between electronic and vibrational degrees of freedom. We study the measure in the hierarchical equation of motion approach which captures strong system-bath coupling effects and non-equilibrium molecular reorganization. We find that, for a model dimer system and the Fenna-Matthews-Olson complex, non-Markovianity is significant under realistic physiological conditions. A first step towards experimental quantification is provided by the study of four-wave mixing initial states.

Rebentrost, Patrick

2010-01-01T23:59:59.000Z

229

One dimensional polaron effects and current inhomogeneities in sequential phonon emission  

SciTech Connect (OSTI)

We have constructed a physical model to explain the tunneling current oscillations reported by Hickmott et al., for GaAs/AlGaAs heterostructures in high magnetic fields. We propose that the periodic structure observed is due to space charge which builds up in the undepleted layer when electrons enter it with energy just below the phonon emission threshold. Such electrons interact with the lattice to form polarons whose energy is pinned to the phonon energy, and thus has a very small group velocity. The polaron effect is strongly enhanced by the confinement of the electrons by the strong magnetic field. We infer from the current-voltage data that most of the tunneling current flows through a small area of the sample. The combined model gives reasonable quantitative agreement with experiment. 6 refs., 6 figs.

Hellman, E.S.; Harris, J.S.; Hanna, C.; Laughlin, R.B.

1985-07-01T23:59:59.000Z

230

Investigation of phonon excitations in {sup 114}Cd with the (n,n{sup '}{gamma}) reaction  

SciTech Connect (OSTI)

Properties of low-spin states in {sup 114}Cd have been studied with the (n,n{sup '}{gamma}) reaction. Gamma-ray angular distributions and excitation functions have been used to characterize the decays of the excited levels. Level lifetimes have been obtained with the Doppler-shift attenuation method. Sixteen new levels and many new transitions have been suggested below 3.5 MeV in excitation energy. Levels belonging to the phonon multiplets have been proposed based on their decay patterns and collectivity, and the existing intruder structure has been extended. A two-phonon 1{sub ms}{sup +} state has been suggested. Excitation of the hexadecapole moment has been considered. Data have been compared with the theoretical calculations of the interacting boson model.

Bandyopadhyay, D.; Lesher, S. R.; Fransen, C.; Boukharouba, N.; McEllistrem, M. T. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Garrett, P. E.; Green, K. L. [Department of Physics, University of Guelph, Guelph, Ontario N1G2W1 (Canada); Yates, S. W. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States)

2007-11-15T23:59:59.000Z

231

Phonon-drag thermopower in anisotropic AlAs quantum wells  

SciTech Connect (OSTI)

In the present work we have developed a generalized theory of phonon-drag thermopower ?{sup g} for a highly anisotropic two-dimensional electron gas. For electrons confined in AlAs quantum wells we calculate ?{sup g} as function of temperature. We show that ?{sup g} exhibits a strong anisotropic behavior depending on valley occupancy which can be tuned by well width and strain. Also a great enhancement of ?{sup g} is observed compared to GaAs quantum wells.

Lehmann, Dietmar [Institute of Theoretical Physics, Technische Universität Dresden, D-01062 Dresden (Germany); Tsaousidou, Margarita [Materials Science Department, University of Patras, Patras 26 504 (Greece); Kubakaddi, Shrishail [Department of Physics, Karnatak University, Dharwad-580 003 (India)

2013-12-04T23:59:59.000Z

232

Covariant density functional theory with two-phonon coupling in nuclei  

SciTech Connect (OSTI)

A full description of excited states within the framework of density functional theory requires energy dependent self energies. We present a new class of many-body models. It allows a parameter free description of the fragmentation of nuclear states induced by mode coupling of two-quasiparticle and two-phonon configurations. The method is applied for an investigation of low-lying dipole excitations in Sn isotopes with large neutron excess.

Ring, P.; Litvinova, E.; Tselyaev, V. [Physik Department, Technische Universitat Muenchen, D-85747 Garching (Germany) and State Key Lab Nucl. Phys. and Tech., School of Physics, Peking University, Beijing 100871 (China); GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Nuclear Physics Department, St. Petersburg State University, 198504 St. Petersburg (Russian Federation)

2012-10-20T23:59:59.000Z

233

Sustainable Office Lighting Options  

E-Print Network [OSTI]

Sustainable Office Lighting Options Task Lighting: Task lighting is a localized method of lighting a workspace so that additional, unnecessary lighting is eliminated, decreasing energy usage and costs. Illumination levels in the targeted work areas are higher with task lighting than with the ambient levels

Massachusetts at Amherst, University of

234

Uv-Light Stabilization Additive Package For Solar Cell Module And Laminated Glass Applications  

DOE Patents [OSTI]

An ultraviolet light stabilization additive package is used in an encapsulant material that may be used in solar cell modules, laminated glass and a variety of other applications. The ultraviolet light stabilization additive package comprises a first hindered amine light stabilizer and a second hindered amine light stabilizer. The first hindered amine light stabilizer provides thermal oxidative stabilization, and the second hindered amine light stabilizer providing photo-oxidative stabilization.

Hanoka, Jack I. (Brookline, MA); Klemchuk, Peter P. (Watertown, CT)

2002-03-05T23:59:59.000Z

235

Thermal sensor with an improved coating  

DOE Patents [OSTI]

The disclosure is directed to an apparatus for detecting radiation having wavelengths from about 0.4 .mu.m to about 5.6 .mu.m. An optical coating is applied to a thermal sensor that is normally transparent to radiation with such wavelengths. The optical coating is thin and light and includes a modifier and an absorber. The thermal sensor can be a pyroelectric detector such as strontium barium niobate.

LaDelfe, Peter C. (Los Alamos, NM); Stotlar, Suzanne C. (Los Alamos, NM)

1986-01-01T23:59:59.000Z

236

Low-Temperature Light Detectors with Neganov-Luke Amplification  

E-Print Network [OSTI]

The simultaneous measurement of phonons and scintillation light induced by incident particles in a scintillating crystal such as CaWO4 is a powerful technique for the active rejection of background induced by gamma's and beta's as well as neutrons in direct Dark Matter searches. However, less than ~1% of the energy deposited in a CaWO4 crystal is detected as light. Thus, very sensitive light detectors are needed for an efficient event-by-event background discrimination. Due to the Neganov-Luke effect, the threshold of low-temperature light detectors based on semiconducting substrates can be improved significantly by drifting the photon-induced electron-hole pairs in an applied electric field. We present measurements with low-temperature light detectors based on this amplification mechanism. The Neganov-Luke effect makes it possible to improve the signal-to-noise ratio of our light detectors by a factor of ~9 corresponding to an energy threshold of ~21 eV. We also describe a method for an absolute energy calib...

Isaila, C; Feilitzsch, F v; Gütlein, A; Kemmer, J; Lachenmaier, T; Lanfranchi, J -C; Pfister, S; Potzel, W; Roth, S; Sivers, M v; Strauss, R; Westphal, W; Wiest, F

2011-01-01T23:59:59.000Z

237

Blue diode-pumped solid-state-laser based on ytterbium doped laser crystals operating on the resonance zero-phonon transition  

DOE Patents [OSTI]

The invention provides an efficient, compact means of generating blue laser light at a wavelength near .about.493+/-3 nm, based on the use of a laser diode-pumped Yb-doped laser crystal emitting on its zero phonon line (ZPL) resonance transition at a wavelength near .about.986+/-6 nm, whose fundamental infrared output radiation is harmonically doubled into the blue spectral region. The invention is applied to the excitation of biofluorescent dyes (in the .about.490-496 nm spectral region) utilized in flow cytometry, immunoassay, DNA sequencing, and other biofluorescence instruments. The preferred host crystals have strong ZPL fluorecence (laser) transitions lying in the spectral range from .about.980 to .about.992 nm (so that when frequency-doubled, they produce output radiation in the spectral range from 490 to 496 nm). Alternate preferred Yb doped tungstate crystals, such as Yb:KY(WO.sub.4).sub.2, may be configured to lase on the resonant ZPL transition near 981 nm (in lieu of the normal 1025 nm transition). The laser light is then doubled in the blue at 490.5 nm.

Krupke, William F. (Pleasanton, CA); Payne, Stephen A. (Castro Valley, CA); Marshall, Christopher D. (Livermore, CA)

2001-01-01T23:59:59.000Z

238

Thermal conductivity changes upon neutron transmutation of {sup 10}B doped diamond  

SciTech Connect (OSTI)

{sup 10}B doped p-type diamond samples were subjected to neutron transmutation reaction using thermal neutron flux of 0.9 × 10{sup 13} cm{sup ?2} s{sup ?1} and fast neutron flux of 0.09 × 10{sup 13} cm{sup ?2} s{sup ?1}. Another sample of epilayer grown on type IIa (110) single crystal diamond substrate was subjected to equal thermal and fast neutron flux of 10{sup 14}?cm{sup ?2} s{sup ?1}. The defects in the diamond samples were previously characterized by different methods. In the present work, thermal conductivity of these diamond samples was determined at room temperature by transient thermoreflectance method. The thermal conductivity change in the samples as a function of neutron fluence is explained by the phonon scattering from the point defects and disordered regions. The thermal conductivity of the diamond samples decreased more rapidly initially and less rapidly for larger neutron fluence. In addition, the thermal conductivity in type IIb diamond decreased less rapidly with thermal neutron fluence compared to the decrease in type IIa diamond subjected to fast neutron fluence. It is concluded that the rate of production of defects during transmutation reaction is slower when thermal neutrons are used. The thermal conductivity of epilayer of diamond subjected to high thermal and fast neutron fluence is associated with the covalent carbon network in the composite structure consisting of disordered carbon and sp{sup 2} bonded nanocrystalline regions.

Jagannadham, K., E-mail: jag-kasichainula@ncsu.edu [Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Verghese, K. [Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Butler, J. E. [Code 6174, Naval research Laboratory, Washington, District of Columbia 20375 (United States)

2014-08-28T23:59:59.000Z

239

Controls for Solid-State Lighting  

SciTech Connect (OSTI)

This study predicts new hybrid lighting applications for LEDs. In hybrid lighting, LEDs provide a low-energy 'standby' light level while another, more powerful, efficient light source provides light for occupied periods. Lighting controls will allow the two light sources to work together through an appropriate control strategy, typically motion-sensing. There are no technical barriers preventing the use of low through high CRI LEDs for standby lighting in many interior and exterior applications today. The total luminous efficacy of LED systems could be raised by increasing the electrical efficiency of LED drivers to the maximum practically achievable level (94%). This would increase system luminous efficacy by 20-25%. The expected market volumes for many types of LEDs should justify the evolution of new LED drivers that use highly efficient ICs and reduce parts count by means of ASICs. Reducing their electronics parts count by offloading discrete components onto integrated circuits (IC) will allow manufacturers to reduce the cost of LED driver electronics. LED luminaire manufacturers will increasingly integrate the LED driver and thermal management directly in the LED fixture. LED luminaires of the future will likely have no need for separable lamp and ballast because the equipment life of all the LED luminaire components will all be about the same (50,000 hours). The controls and communications techniques used for communicating with conventional light sources, such as dimmable fluorescent lighting, are appropriate for LED illumination for energy management purposes. DALI has been used to control LED systems in new applications and the emerging ZigBee protocol could be used for LEDs as well. Major lighting companies are already moving in this direction. The most significant finding is that there is a significant opportunity to use LEDs today for standby lighting purposes. Conventional lighting systems can be made more efficient still by using LEDs to provide a low-energy standby state when lower light levels are acceptable.

Rubinstein, Francis

2007-06-22T23:59:59.000Z

240

Spectroscopy of particle-phonon coupled states in 133Sb by the cluster transfer reaction of 132Sn on 7Li: an advanced test of nuclear interactions  

E-Print Network [OSTI]

Spectroscopy of particle-phonon coupled states in 133Sb by the cluster transfer reaction of 132Sn on 7Li: an advanced test of nuclear interactions

Leoni S, University of Milano and INFN Milano (Italy); Bocchi G, University of Milano and INFN Milano (Italy); Bottoni S, University of Milano and INFN Milano (Italy); Bracco A, University of Milano and INFN Milano (Italy); Camera F, University of Milano and INFN Milano (Italy; Crespi F, University of Milano and INFN Milano (Italy); Morales A, University of Milano and INFN Milano (Italy); Fornal B, IFJ-PAN Krakow (Poland); Szpak B, IFJ-PAN Krakow (Poland); Bednarczyk P, IFJ-PAN Krakow (Poland); Cieplicka N, IFJ-PAN Krakow (Poland); Krolas W, IFJ-PAN Krakow ( Poland); Maj A, IFJ-PAN Krakow (Poland); Rusek K, Heavy Ion Laboratory University of Warsaw (Poland); Bazzacco D, INFN Padova (Italy); Lunardi S, University of Padova and INFN Padova (Italy); Mengoni D, University of Padova and INFN Padova (Italy); Recchia F, University of Padova and INFN Padova (Italy); Ur C, INFN Padova (Italy); Valiente-Dobon J, LNL-INFN (Italy); Gramegna F, LNL-INFN (Italy); Marchi T, LNL-INFN (Italy); Huyse M, KU Leuven (Belgium); Raabe R, KU Leuven (Belgium); VanDuppen P, KU Leuven (Belgium); Sferrazza M, Université libre de Bruxelles (Belgium); Georgiev G, CSNSM Orsay (France); Blazhev A, Institut fur Kernphysik der Universitat zu Köln (Germany); Rosiak D, Institut fur Kernphysik der Universitat zu Köln (Germany); Siebeck B, Institut fur Kernphysik der Universitat zu Köln (Germany); Seidlitz M, Institut fur Kernphysik der Universitat zu Köln (Germany); Reiter P, Institut fur Kernphysik der Universitat zu Köln (Germany); Warr N, Institut fur Kernphysik der Universitat zu Koln (Germany); Hartig AL, TU Darmstadt (Germany); Henrich C, TU Darmstadt (Germany); Ilieva S, TU Darmstadt (Germany); Kroell T, TU Darmstadt (Germany); Thurauf M, TU Darmstadt (Germany); Gernhaeuser R, TU Munchen (Germany); Mucher D, TU Munchen (Germany); Janssens R, Argonne National Laboratory (USA); Carpenter MP, Argonne National Laboratory (USA); Zhu S, Argonne National Laboratory (USA); Kowalska M, ISOLDE-CERN (Switzerland); CERN. Geneva. ISOLDE and neutron Time-of-Flight Experiments Committee; INTC

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Temperature Dependence of the Optical Transition Energies of Carbon Nanotubes: The Role of Electron-Phonon Coupling and Thermal Expansion  

E-Print Network [OSTI]

Temperature Dependence of the Optical Transition Energies of Carbon Nanotubes: The Role of Electron to measure the optical transition energies Eii of individual single wall carbon nanotubes. Eii is observed of nanotubes we are able to use the temperature as a parame- ter to tune the electronic energies of nanotubes

Cronin, Steve

242

Thermal conductivity of self-assembled nano-structured ZnO bulk ceramics  

SciTech Connect (OSTI)

In this study, we describe the changes in thermal conductivity behavior of ZnO-Al micro- and nano-two-phase self-assembled composites with varying grain sizes. The reduction in thermal conductivity values of micro-composites was limited to {approx}15% for ZnO-4% Al. However, nano-composites exhibited large reduction, by a factor of about three, due to uniform distribution of nano-precipitates (ZnAl2O4) and large grain boundary area. Interestingly, the micro-composites revealed continuous decrease in thermal conductivity with increase in Al substitution while the nano-composites exhibited the lowest magnitudes for 2% Al concentration. Raman spectra indicated that phonon confinement in ZnO-Al nano-composites causes drastic decrease in the value of thermal conductivity.

Zhao, Yu [Bio-Inspired Materials and Devices Laboraory (BMDL); Yan, Yongke [Bio-Inspired Materials and Devices Laboraory (BMDL); Kumar, Ashok [Bio-Inspired Materials and Devices Laboraory (BMDL); Wang, Hsin [ORNL; Porter, Wallace D [ORNL

2012-01-01T23:59:59.000Z

243

Thermal conductivity of thermal-battery insulations  

SciTech Connect (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

244

Light front Casimir effect at finite temperature  

E-Print Network [OSTI]

The correct description of the standard Casimir effect for periodic boundary conditions via light front formalism implies in these conditions imposed at fixed Minkowski times [Almeida {\\it et al.} Phys. Rev. {\\bf D 87}, 065028 (2013); Chabysheva and Hiller, Phys. Rev. {\\bf D 88}, 085006 (2013)] instead of fixed light front times. The unphysical nature of this latter condition is manifested in the vacuum part by no regularization yielding a finite Casimir energy density [Lenz and Steinbacher, Phys. Rev. {\\bf D 67}, 045010 (2003)]. In the present paper, we extend this discussion and analyze the problem of the light front quantization with simultaneous presence of a thermal bath and boundary conditions. Considering both the oblique light front as well as Dirac light front coordinates, we show that the imposition of periodic boundary conditions at fixed Minkowski times recovers the expected behaviors for the energy density and Casimir entropy. We also investigate how the unphysical nature of the periodic boundary...

Rodrigues, P L M; Alves, Danilo T; Alves, Van Sérgio; Silva, Charles R

2015-01-01T23:59:59.000Z

245

Coherent Phonon-Grain Boundary Scattering in Silicon Inverse Opals Bibek R. Parajuli,,  

E-Print Network [OSTI]

in the structure. The corresponding material thermal conductivity is in the range 5-12 W/mK and has an anomalous T1 the lattice structure resulting in significant increase in thermal resistance. At microscopic length scales thermal conductivity of the material. Previous theoretical work on thermal transport in inverse opals12

Braun, Paul

246

Lighting Options for Homes.  

SciTech Connect (OSTI)

This report covers many aspects of various lighting options for homes. Types of light sources described include natural light, artificial light, incandescent lamps, fluorescent lamps, and high intensity discharge lamps. A light source selection guide gives the physical characteristics of these, design considerations, and common applications. Color, strategies for efficient lighting, and types of lighting are discussed. There is one section giving tips for various situations in specific rooms. Rooms and types of fixtures are shown on a matrix with watts saved by using the recommended type lighting for that room and room location. A major emphasis of this report is saving energy by utilizing the most suitable, recommended lighting option. (BN)

Baker, W.S.

1991-04-01T23:59:59.000Z

247

Mobile lighting apparatus  

DOE Patents [OSTI]

A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

2013-05-14T23:59:59.000Z

248

High Temperature Thermal Array for Next Generation Solar Thermal...  

Broader source: Energy.gov (indexed) [DOE]

High Temperature Thermal Array for Next Generation Solar Thermal Power Production High Temperature Thermal Array for Next Generation Solar Thermal Power Production This...

249

EK101 Engineering Light Smart Lighting  

E-Print Network [OSTI]

EK101 Engineering Light Smart Lighting Homework for 9/10 1. Make an estimate (using if the patent is granted.) 3. What is a lumen? A lux? How are the two related? How would you use a lux meter, (Lux, Lumens/m2) Luminous Flux: Perceivable light power from a source, (Lumens) Use the lux meter

Bifano, Thomas

250

Influence of Complex Exciton-Phonon Coupling on Optical Absorption and Energy Transfer of Quantum Aggregates  

E-Print Network [OSTI]

We present a theory that efficiently describes the quantum dynamics of an electronic excitation that is coupled to a continuous, highly structured phonon environment. Based on a stochastic approach to non-Markovian open quantum systems, we develop a dynamical framework that allows us to handle realistic systems where a fully quantum treatment is desired yet the usual approximation schemes fail. The capability of the method is demonstrated by calculating spectra and energy transfer dynamics of mesoscopic molecular aggregates, elucidating the transition from fully coherent to incoherent transfer.

Jan Roden; Alexander Eisfeld; Wolfgang Wolff; Walter T. Strunz

2009-11-04T23:59:59.000Z

251

Cooling carbon nanotubes to the phononic ground state with constant electron current  

E-Print Network [OSTI]

We present a quantum theory of cooling of a mechanical resonator using back-action with constant electron current. The resonator device is based on a doubly clamped nanotube, which mechanically vibrates and acts as a double quantum dot for electron transport. Mechanical vibrations and electrons are coupled electrostatically using an external gate. The fundamental eigenmode is cooled by absorbing phonons when electrons tunnel through the double quantum dot. We identify the regimes in which ground state cooling can be achieved for realistic experimental parameters.

Stefano Zippilli; Giovanna Morigi; Adrian Bachtold

2009-03-06T23:59:59.000Z

252

Specific light in sculpture  

E-Print Network [OSTI]

Specific light is defined as light from artificial or altered natural sources. The use and manipulation of light in three dimensional sculptural work is discussed in an historic and contemporary context. The author's work ...

Powell, John William

1989-01-01T23:59:59.000Z

253

Seasonal thermal energy storage  

SciTech Connect (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

254

Pulse thermal processing of functional materials using directed plasma arc  

DOE Patents [OSTI]

A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.

Ott, Ronald D. (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Dudney, Nancy J. (Knoxville, TN); Harper, David C. (Kingston, TN)

2007-05-22T23:59:59.000Z

255

Thermal unobtainiums? The perfect thermal conductor and  

E-Print Network [OSTI]

contribute to thermal resistance · Isotopically pure diamond has highest thermal conductivity of any material materials: disordered layered crystals Conclude with some thoughts on promising, high-risk, research even in a computer model. #12;Thermal resistance is created by Umklapp scattering (U

Braun, Paul

256

Shear-horizontal surface acoustic wave phononic device with high density filling material for ultra-low power sensing applications  

SciTech Connect (OSTI)

Finite element simulations of a phononic shear-horizontal surface acoustic wave (SAW) sensor based on ST 90°-X Quartz reveal a dramatic reduction in power consumption. The phononic sensor is realized by artificially structuring the delay path to form an acoustic meta-material comprised of a periodic microcavity array incorporating high-density materials such as tantalum or tungsten. Constructive interference of the scattered and secondary reflected waves at every microcavity interface leads to acoustic energy confinement in the high-density regions translating into reduced power loss. Tantalum filled cavities show the best performance while tungsten inclusions create a phononic bandgap. Based on our simulation results, SAW devices with tantalum filled microcavities were fabricated and shown to significantly decrease insertion loss. Our findings offer encouraging prospects for designing low power, highly sensitive portable biosensors.

Richardson, M.; Bhethanabotla, V. R., E-mail: bhethana@usf.edu [Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, Florida 33620 (United States); Sankaranarayanan, S. K. R. S. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2014-06-23T23:59:59.000Z

257

Indication of Te segregation in laser-irradiated ZnTe observed by in situ coherent-phonon spectroscopy  

SciTech Connect (OSTI)

We irradiate a ZnTe single crystal with 10-fs laser pulses at a repetition rate of 80?MHz and investigate its resulting gradual modification by means of coherent-phonon spectroscopy. We observe the emergence of a phonon mode at about 3.6?THz whose amplitude and lifetime grow monotonously with irradiation time. The speed of this process depends sensitively on the pump-pulse duration. Our observations strongly indicate that the emerging phonon mode arises from a Te phase induced by multiphoton absorption of incident laser pulses. A potential application of our findings is laser-machining of microstructures in the bulk of a ZnTe crystal, a highly relevant electrooptic material.

Shimada, Toru [Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany); Hirosaki University, 1 Bunkyo-cho, Hirosaki, Aomori 036-8152 (Japan); Kamaraju, N., E-mail: nkamaraju@lanl.gov [Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany); Los Alamos National Laboratory, Center for Integrated Nanotechnologies, Los Alamos, New Mexico 87545 (United States); Frischkorn, Christian [Department of Physics, Free University of Berlin, Arnimallee 14, 14195 Berlin (Germany); Wolf, Martin; Kampfrath, Tobias [Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany)

2014-09-15T23:59:59.000Z

258

Polymer and small molecule based hybrid light source  

DOE Patents [OSTI]

An organic electroluminescent device, includes: a substrate; a hole-injecting electrode (anode) coated over the substrate; a hole injection layer coated over the anode; a hole transporting layer coated over the hole injection layer; a polymer based light emitting layer, coated over the hole transporting layer; a small molecule based light emitting layer, thermally evaporated over the polymer based light emitting layer; and an electron-injecting electrode (cathode) deposited over the electroluminescent polymer layer.

Choong, Vi-En (Carlsbad, CA); Choulis, Stelios (Nuremberg, DE); Krummacher, Benjamin Claus (Regensburg, DE); Mathai, Mathew (Monroeville, PA); So, Franky (Gainesville, FL)

2010-03-16T23:59:59.000Z

259

Thermal Control & System Integration  

Broader source: Energy.gov [DOE]

The thermal control and system integration activity focuses on issues such as the integration of motor and power control technologies and the development of advanced thermal control technologies....

260

Thermal Storage Applications for Commercial/Industrial Facilities  

E-Print Network [OSTI]

THERMAL STORAGE APPLICATIONS FOR COMMERCIAL/INDUSTRIAL FACILITIES Roger 1. Knipp, PE. Dallas Power & Light Company Dallas, Texas ABSTRACT Texas Utilities Electric Company has been actively encouraging installations of thermal storage... since 1981. Financial incentives and advantageous rates can make thermal storage an attractive cooling concept in Texas Utilities Electric Company service area. Currently, 14 million square feet of commercial building space in Dallas is either...

Knipp, R. L.

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Light front Casimir effect at finite temperature  

E-Print Network [OSTI]

The correct description of the standard Casimir effect for periodic boundary conditions via light front formalism implies in these conditions imposed at fixed Minkowski times [Almeida {\\it et al.} Phys. Rev. {\\bf D 87}, 065028 (2013); Chabysheva and Hiller, Phys. Rev. {\\bf D 88}, 085006 (2013)] instead of fixed light front times. The unphysical nature of this latter condition is manifested in the vacuum part by no regularization yielding a finite Casimir energy density [Lenz and Steinbacher, Phys. Rev. {\\bf D 67}, 045010 (2003)]. In the present paper, we extend this discussion and analyze the problem of the light front quantization with simultaneous presence of a thermal bath and boundary conditions. Considering both the oblique light front as well as Dirac light front coordinates, we show that the imposition of periodic boundary conditions at fixed Minkowski times recovers the expected behaviors for the energy density and Casimir entropy. We also investigate how the unphysical nature of the periodic boundary conditions imposed at fixed light front times manifests in the thermal part of the energy and entropy, showing that in the classical limit the Casimir entropy decreases linearly with the temperature (not becoming independent of the temperature as expected), and also that the Kirchhoff theorem is not respected.

P. L. M. Rodrigues; Silvana Perez; Danilo T. Alves; Van Sérgio Alves; Charles R. Silva

2015-01-06T23:59:59.000Z

262

Radiative cooling of bulk silicon by incoherent light pump  

SciTech Connect (OSTI)

In contrast to radiative cooling by light up conversion caused exclusively by a low-entropy laser pump and employing thermally assisted fluorescence/luminescence as a power out, we demonstrate light down conversion cooling by incoherent pumps, 0.47–0.94??m light emitting diodes, and employing thermal emission (TE) as a power out. We demonstrate ?3.5?K bulk cooling of Si at 450?K because overall energy of multiple below bandgap TE photons exceeds the energy of a single above bandgap pump photon. We show that using large entropy TE as power out helps avoid careful tuning of an incoherent pump wavelength and cool indirect-bandgap semiconductors.

Malyutenko, V. K., E-mail: malyut@isp.kiev.ua; Bogatyrenko, V. V.; Malyutenko, O. Yu. [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)] [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)

2013-12-23T23:59:59.000Z

263

Superlensing effect for surface acoustic waves in a pillar-based phononic crystal with negative refractive index  

SciTech Connect (OSTI)

We demonstrate super resolution imaging for surface acoustic waves using a phononic structure displaying negative refractive index. This phononic structure is made of a monolithic square lattice of cylindrical pillars standing on a semi-infinite medium. The pillars act as acoustic resonator and induce a surface propagating wave with unusual dispersion. We found, under specific geometrical parameters, one propagating mode that exhibits negative refraction effect with negative effective index close to ?1. Furthermore, a flat lens with finite number of pillars is designed to allow the focusing of an acoustic point source into an image with a resolution of (?)/3 , overcoming the Rayleigh diffraction limit.

Addouche, Mahmoud, E-mail: mamoud.addouche@femto-st.fr; Al-Lethawe, Mohammed A., E-mail: mohammed.abdulridha@femto-st.fr; Choujaa, Abdelkrim, E-mail: achoujaa@femto-st.fr; Khelif, Abdelkrim, E-mail: abdelkrim.khelif@femto-st.fr [Institut FEMTO-ST, Université de Franche-Comté, CNRS, 32 Avenue de l'Observatoire, 25044 Besançon Cedex (France)

2014-07-14T23:59:59.000Z

264

Trends in the electron-phonon coupling parameter in some metallic hydrides  

SciTech Connect (OSTI)

We present an evaluation of the electron-phonon coupling parameter lambda, using the McMillan formalism, for several classes of stoichiometric mono- and dihydrides with a metallic underlying fcc structure. We calculate the electronic term eta and use experimental estimates for the phonon energies when available. We derive systematic trends concerning both contributions to eta stemming, respectively, from the metallic site M and the hydrogen site H. We show that eta/sub H/ is generally small, but it may become large if the Fermi energy is in the metal s-p band as in the filled d-band transition-metal (TM) hydrides such as PdH; eta/sub H/ may also be large when a metal-hydrogen antibonding band crosses the Fermi level, a case which happens in AlH and may happen for some unstable dihydrides. The metallic contribution eta/sub M/ is calculated to be small for all stable mono- and dihydrides like PdH, NiH, ZrH/sub 2/, NbH/sub 2/, etc., but nothing in principle prevents this contribution from becoming as large as in some pure TM, if one sweeps the Fermi level through the whole metallic d band. Good agreement with the available experimental data is obtained concerning the occurrence of superconductivity in the compounds considered.

Gupta, M.; Burger, J.P.

1981-12-15T23:59:59.000Z

265

Position and energy-resolved particle detection using phonon-mediated microwave kinetic inductance detectors  

SciTech Connect (OSTI)

We demonstrate position and energy-resolved phonon-mediated detection of particle interactions in a silicon substrate instrumented with an array of microwave kinetic inductance detectors (MKIDs). The relative magnitude and delay of the signal received in each sensor allow the location of the interaction to be determined with < or approx. 1mm resolution at 30 keV. Using this position information, variations in the detector response with position can be removed, and an energy resolution of {sigma}{sub E} = 0.55 keV at 30 keV was measured. Since MKIDs can be fabricated from a single deposited film and are naturally multiplexed in the frequency domain, this technology can be extended to provide highly pixelized athermal phonon sensors for {approx}1 kg scale detector elements. Such high-resolution, massive particle detectors would be applicable to rare-event searches such as the direct detection of dark matter, neutrinoless double-beta decay, or coherent neutrino-nucleus scattering.

Moore, D. C.; Golwala, S. R.; Cornell, B. [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125 (United States); Bumble, B.; Day, P. K.; LeDuc, H. G. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States); Zmuidzinas, J. [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125 (United States); Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

2012-06-04T23:59:59.000Z

266

Role of phonon scattering by elastic strain field in thermoelectric Sr{sub 1?x}Y{sub x}TiO{sub 3??}  

SciTech Connect (OSTI)

Perovskite-type SrTiO{sub 3??} ceramics are multifunctional materials with significant potential as n-type thermoelectric (TE) materials. The electronic and thermal transport properties of spark plasma sintered polycrystalline Sr{sub 1?x}Y{sub x}TiO{sub 3??} (x?=?0.05, 0.075, 0.1) ceramics are systematically investigated from (15–800) K. The Sr{sub 0.9}Y{sub 0.1}TiO{sub 3??} simultaneously exhibits a large Seebeck coefficient, ??>??80??V/K and moderately high electrical resistivity, ????0.8?m?-cm at a carrier concentration of ?10{sup 21}?cm{sup ?3} at 300?K resulting in a high TE power factor defined herein as (?{sup 2}?T)???0.84?W/m-K at 760?K. Despite the similar atomic masses of Sr (87.6?g/mol) and Y (88.9?g/mol), the lattice thermal conductivity (?{sub L}) of Sr{sub 1?x}Y{sub x}TiO{sub 3??} is significantly reduced with increased Y-doping, owing to the smaller ionic radii of Y{sup 3+} (?1.23?Å, coordination number 12) compared to Sr{sup 2+} (?1.44?Å, coordination number 12) ions. In order to understand the thermal conductivity reduction mechanism, the ?{sub L} in the Sr{sub 1?x}Y{sub x}TiO{sub 3??} series are phenomenologically modeled with a modified Callaway's equation from 30–600?K. Phonon scattering by elastic strain field due to ionic radii mismatch is found to be the prominent scattering mechanism in reducing ?{sub L} of these materials. In addition, the effect of Y-doping on the elastic moduli of Sr{sub 1?x}Y{sub x}TiO{sub 3??} (x?=?0, 0.1) is investigated using resonant ultrasound spectroscopy, which exhibits an anomaly in x?=?0.1 in the temperature range 300–600?K. As a result, the phonon mean free path is found to be further reduced in the Sr{sub 0.9}Y{sub 0.1}TiO{sub 3??} compared to that of SrTiO{sub 3??}, resulting in a considerably low thermal conductivity ????2.7?W/m-K at 760?K. Finally, we report a thermoelectric figure of merit (ZT)???0.3 at 760?K in the Sr{sub 0.9}Y{sub 0.1}TiO{sub 3??}, the highest ZT value reported in the Y-doped SrTiO{sub 3} ceramics thus far.

Bhattacharya, S., E-mail: bbhatta@clemson.edu, E-mail: ttritt@clemson.edu [Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634 (United States); Mehdizadeh Dehkordi, A. [Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634 (United States); Tennakoon, S.; Adebisi, R.; Gladden, J. R. [Department of Physics and National Center for Physical Acoustics, University of Mississippi, University, Mississippi 38677 (United States); Darroudi, T. [Electron Microscope Facility, Clemson Research Park, Clemson University, Clemson, South Carolina 29625 (United States); Alshareef, H. N. [Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Tritt, T. M., E-mail: bbhatta@clemson.edu, E-mail: ttritt@clemson.edu [Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634 (United States); Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634 (United States)

2014-06-14T23:59:59.000Z

267

Temperature-Dependent Phonon Conduction and Nanotube Engagement in Metalized Single Wall Carbon  

E-Print Network [OSTI]

storage materials.9 They potentially offer the unique combination of low thermal resistance, MWNT) films are promising materials for thermal management1-4 and electronics applications,4,14,15 and physically deposited metals,3,15 yield large nanotube-substrate thermal interface resistances in the range

Maruyama, Shigeo

268

Ballistic Phonon Transport in Ultra-Thin Silicon Layers: Effects of Confinement and Orientation  

E-Print Network [OSTI]

­23]. The thermal conductivity in bulk Si is isotropic, however, in low-dimensional materials the choice formalism to calculate the thermal conductance. We consider the major thin layer surface orientations {100}, {110}, {111}, and {112}. For every surface orientation, we study thermal conductance as a function

269

Method and apparatus for thermal management of vehicle exhaust systems  

DOE Patents [OSTI]

A catalytic converter is surrounded by variable conductance insulation for maintaining the operating temperature of the catalytic converter at an optimum level, for inhibiting heat loss when raising catalytic converter temperature to light-off temperature, for storing excess heat to maintain or accelerate reaching light-off temperature, and for conducting excess heat away from the catalytic converter after reaching light-off temperature. The variable conductance insulation includes vacuum gas control and metal-to-metal thermal shunt mechanisms. Radial and axial shielding inhibits radiation and convection heat loss. Thermal storage media includes phase change material, and heat exchanger chambers and fluids carry heat to and from the catalytic converter.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1995-01-01T23:59:59.000Z

270

DDbar Correlations probing Thermalization in High-Energy Nuclear Collisions  

E-Print Network [OSTI]

We propose to measure azimuthal correlations of heavy-flavor hadrons to address the status of thermalization at the partonic stage of light quarks and gluons in high-energy nuclear collisions. In particular, we show that hadronic interactions at the late stage cannot significantly disturb the initial back-to-back azimuthal correlations of DDbar pairs. Thus, a decrease or the complete absence of these initial correlations does indicate frequent interactions of heavy-flavor quarks and also light partons in the partonic stage, which are essential for the early thermalization of light partons.

K. Schweda; X. Zhu; M. Bleicher; S. L. Huang; H. Stoecker; N. Xu; P. Zhuang

2006-10-30T23:59:59.000Z

271

Thermal Management of Solar Cells  

E-Print Network [OSTI]

a better thermal conductance and when ceramic particles areor ceramic fillers that enhances thermal conductivity. Solid

Saadah, Mohammed Ahmed

2013-01-01T23:59:59.000Z

272

Ballistic thermal transport in a cylindrical semiconductor nanowire modulated with bridge contacts  

SciTech Connect (OSTI)

Using the scattering-matrix method, we studied ballistic phonon transmission and thermal conductance at low temperatures in a cylindrical quantum wire with bridge contacts. The transmission coefficient exhibited a stepped profile, which became more evident as the bridge radius increased. When the dimensions of the bridge are identical to those of main wires, we observed a quantum platform of the thermal conductance, even in the presence of interface scattering. When the dimensions of the bridge are smaller than those of main wires, however, we could not observe the quantum platform. We also revealed other interesting physical properties, such as universal quantum thermal conductance and resonant transmission. A brief analysis of these results is given.

Zhang, Yong, E-mail: apzhangyong@126.com; Xie, Zhong-Xiang, E-mail: xiezxhu@163.com; Yu, Xia; Wang, Hai-Bin [Department of Mathematics and Physics, Hunan Institute of Technology, Hengyang 421002 (China); Li, Ke-Min [Department of Physics and Electronics Information, Hunan Institute of Science and Technology, Yueyang 414004 (China)

2014-10-14T23:59:59.000Z

273

Lighting and Daylight Harvesting  

E-Print Network [OSTI]

exposing us to the latest products and technologies. Daylight Harvesting A system of controlling the direction and the quantity of light both natural and artificial within a given space. This implies: Control of fenestration in terms of size..., transmission and direction. Control of reflected light within a space. Control of electric light in terms of delivery and amount Daylight harvesting systems are typically designed to maintain a minimum recommended light level. This light level...

Bos, J.

2011-01-01T23:59:59.000Z

274

Thermalization properties at mK temperatures of a nanoscale optomechanical resonator with acoustic-bandgap shield  

E-Print Network [OSTI]

Optical measurements of a nanoscale silicon optomechanical crystal cavity with a mechanical resonance frequency of 3.6GHz are performed at sub-kelvin temperatures. We infer optical-absorption-induced heating and damping of the mechanical resonator from measurements of phonon occupancy and motional sideband asymmetry. At the lowest probe power and lowest fridge temperature (10mK), the localized mechanical resonance is found to couple at a rate of 400Hz (Q=9x10^6) to a thermal bath of temperature 270mK. These measurements indicate that silicon optomechanical crystals cooled to millikelvin temperatures should be suitable for a variety of experiments involving coherent coupling between photons and phonons at the single quanta level.

Sean M. Meenehan; Justin D. Cohen; Simon Groeblacher; Jeff T. Hill; Amir H. Safavi-Naeini; Markus Aspelmeyer; Oskar Painter

2014-03-14T23:59:59.000Z

275

Thermal element for maintaining minimum lamp wall temperature in fluorescent fixtures  

DOE Patents [OSTI]

In a lighting fixture including a lamp and a housing, an improvement is disclosed for maintaining a lamp envelope area at a cooler, reduced temperature relative to the enclosed housing ambient. The improvement comprises a thermal element in thermal communication with the housing extending to and springably urging thermal communication with a predetermined area of the lamp envelope surface.

Siminovitch, Michael J. (Richmond, CA)

1992-01-01T23:59:59.000Z

276

Thermal boundary resistance between single-walled carbon nanotubes and surrounding matrices  

E-Print Network [OSTI]

Thermal boundary resistance between single-walled carbon nanotubes and surrounding matrices Carl Keywords: carbon nanotube, thermal boundary resistance, molecular dynamics 1 #12;I. INTRODUCTION the thermal conductivity of insulating materials15,16 . The mechanical strength and light weight of polymers

Maruyama, Shigeo

277

Thermal element for maintaining minimum lamp wall temperature in fluorescent fixtures  

DOE Patents [OSTI]

In a lighting fixture including a lamp and a housing, an improvement is disclosed for maintaining a lamp envelope area at a cooler, reduced temperature relative to the enclosed housing ambient. The improvement comprises a thermal element in thermal communication with the housing extending to and springably urging thermal communication with a predetermined area of the lamp envelope surface. 12 figs.

Siminovitch, M.J.

1992-11-10T23:59:59.000Z

278

PHONONS-DEFECTS INTERACTIONS IN CdTe J. L. TISSOT, P. L. VUILLERMOZ and A. LAUGIER  

E-Print Network [OSTI]

267 PHONONS-DEFECTS INTERACTIONS IN CdTe J. L. TISSOT, P. L. VUILLERMOZ and A. LAUGIER Laboratoire Einstein, 69621 Villeurbanne Cedex, France Résumé. 2014 Les défauts électriquement inactifs dans CdTe ont of electrically inactive defects has been performed on CdTe single crystals by two different experimental

Boyer, Edmond

279

PHYSICAL REVIEW B 84, 205305 (2011) Spin-phonon coupling in single Mn-doped CdTe quantum dot  

E-Print Network [OSTI]

PHYSICAL REVIEW B 84, 205305 (2011) Spin-phonon coupling in single Mn-doped CdTe quantum dot C. L dynamics of a single Mn atom in a laser driven CdTe quantum dot is addressed theoretically. Recent of single Mn-doped CdTe dots, information about the quantum spin state of a single Mn atom is extracted from

Paris-Sud XI, Université de

280

PHYSICAL REVIEW B 88, 144307 (2013) Direct observation of the phonon dispersion of a three-dimensional solid/solid  

E-Print Network [OSTI]

,17 In previous works, the phononics are solid/fluid systems consisting of periodically arranged solid inclusions-dimensional solid/solid hypersonic colloidal crystal Gaohua Zhu,1,* Nichlas Z. Swinteck,2 Songtao Wu,1 Jin S. Zhang crystal, comprised of close-packed polystyrene spheres embedded in a background matrix of solid

Deymier, Pierre

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates: A split of phonon band gap  

E-Print Network [OSTI]

Propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates: A split of phonon the propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates made of tungsten B spectra, Raman scattering spectra, and propagating modes of acoustic waves on corrugated surfaces.14

Li, Baowen

282

Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium: a first-principles study  

E-Print Network [OSTI]

Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium CEA-DIF, 91297 Arpajon, France (Dated: April 3, 2014) The electronic behavior of various solid metals modelled based on the free electron classical theory, the free electron number is a key parameter. However

Paris-Sud XI, Université de

283

Solar Thermal Demonstration Project  

SciTech Connect (OSTI)

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 â??Kalwallâ?? building panels. An added feature of the â??Kalwallâ? 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

284

Electronic properties and electron-phonon coupling in zirconium and niobium hydrides  

SciTech Connect (OSTI)

The electronic structure of the two 4d transition-metal cubic dihydrides ZrH/sub 2/ and NbH/sub 2/ is investigated by means of an augmented-plane-wave (APW) band-structure calculation. The position of the Fermi level in a peak of the density of states (DOS) in the case of cubic ZrH/sub 2/ leads to an interpretation of the tetragonal distortion observed in all the group-IV transition-metal dihydrides in terms of a Jahn-Teller effect which lifts the degeneracy of the doubly degenerate band in the GAMMAL direction; these results are in agreement with magnetic susceptibility, electronic specific heat and thermoelectric power data. The main features of the DOS of the metal 4d states are similar for ZrH/sub 2/ and NbH/sub 2/, while the position and width of the low-lying bands are found to depend substantially upon the compound under study. These two bands which result from metal-hydrogen and hydrogen-hydrogen interactions overlap the metal d bands located at higher energies, contrary to the case of rare-earth dihydrides for which an energy gap was obtained. Our theoretical results are in good agreement with photoemission and x-ray emission spectra. We have evaluated the electron-phonon coupling constant lambda using the results of our APW calculation in conjunction with neutron scattering data. For both ZrH/sub 2/ and NbH/sub 2/, and contrary to the case of superconducting PdH, the electron-optical phonon contribution is small, due essentially to the low value of the DOS of s type at the H site at the Fermi energy and to the hardening of the optic modes. Moreover, the electronic term of the electron--acoustic-phonon contribution is reduced from its value in the pure metal. The two compounds are not found to be superconducting, in agreement with experimental results.

Gupta, M.

1982-01-15T23:59:59.000Z

285

Thermally efficient compact fluorescent fixture systems  

SciTech Connect (OSTI)

Compact fluorescent lamps that can be inserted into conventional light fixtures are rapidly gaining acceptance as both a viable retrofit and new design approach to reducing lighting loads. Ideally, the compact fluorescent lamp should have the same light output as the incandescent lamp it replaces, but overheating inside typically small enclosed fixtures can reduce lumen output and hence lighting fixture efficiency by 15 to 20 percent. Fortunately, simple fixture modifications can erase this efficiency penalty, so that the full efficiency benefit of replacing incandescent lamps with fluorescent lamps can be realized. The paper describes such modifications and presents experimental data documenting the potential efficiency enhancement associated with thermal control systems. 4 refs., 7 figs.

Siminovitch, M.J.; Rubinstein, F.M.; Packer, M.

1991-04-01T23:59:59.000Z

286

Phononic pairing glue in cuprates and related high-temperature superconductors  

E-Print Network [OSTI]

Along with some other researches we have realised that the true origin of high-temperature superconductivity should be found in the strong Coulomb repulsion combined with a significant electronphonon interaction. Both interactions are strong (on the order of 1 eV) compared with the low Fermi energy of doped carries which makes the conventional BCS-Eliashberg theory inapplicable in cuprates and related doped insulators. Based on our recent analytical and numerical results I argue that high-temperature superconductivity from repulsion is impossible for any strength of the Coulomb interaction. Major steps of our alternative polaronic theory are outlined starting from the generic Hamiltonian with the unscreened (bare) Coulomb and electron-phonon interactions accounting for critical temperatures of high-temperature superconductors without any adjustable parameters.

A. S. Alexandrov

2011-12-16T23:59:59.000Z

287

49 (2012-5) Investigation of phonon transport in alloyed crystals by perturbation approach  

E-Print Network [OSTI]

�6�6, 20 K TA1 TA2 LA mi/m=0.2 mi/m=0.5 mi/m=0.8 mi/m=1.2 mi/m=1.8 mi/m=2.0 mi/m=3.0 mi/m=5.0 2% mi/m=1 concentration at 20 K. 1 10 ­4 10 ­3 10 ­2 10 ­1 ms(THz) Frequency (THz) 6�6�6, 20 K TA1 TA2 LA mi/m=0.2 mi/m=0.5 mi/m=0.8 mi/m=1.5 mi/m=1.8 mi/m=2.0 mi/m=3.0 mi/m=5.0 2% 4 4 Fig. 3 Phonon scattering rates due

Maruyama, Shigeo

288

Low-phonon-frequency chalcogenide crystalline hosts for rare earth lasers operating beyond three microns  

DOE Patents [OSTI]

The invention comprises a RE-doped MA.sub.2 X.sub.4 crystalline gain medium, where M includes a divalent ion such as Mg, Ca, Sr, Ba, Pb, Eu, or Yb; A is selected from trivalent ions including Al, Ga, and In; X is one of the chalcogenide ions S, Se, and Te; and RE represents the trivalent rare earth ions. The MA.sub.2 X.sub.4 gain medium can be employed in a laser oscillator or a laser amplifier. Possible pump sources include diode lasers, as well as other laser pump sources. The laser wavelengths generated are greater than 3 microns, as becomes possible because of the low phonon frequency of this host medium. The invention may be used to seed optical devices such as optical parametric oscillators and other lasers.

Payne, Stephen A. (Castro Valley, CA); Page, Ralph H. (San Ramon, CA); Schaffers, Kathleen I. (Pleasanton, CA); Nostrand, Michael C. (Livermore, CA); Krupke, William F. (Pleasanton, CA); Schunemann, Peter G. (Malden, MA)

2000-01-01T23:59:59.000Z

289

Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting phase  

E-Print Network [OSTI]

In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type--II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.

M. N. Chernodub; Jos Van Doorsselaere; Henri Verschelde

2014-06-16T23:59:59.000Z

290

Holographic thermalization patterns  

E-Print Network [OSTI]

We investigate the behaviour of various correlators in N=4 super Yang Mills theory, taking finite coupling corrections into account. In the thermal limit we investigate the flow of the quasinormal modes as a function of the 't Hooft coupling. Then by using a specific model of holographic thermalization we investigate the deviation of the spectral densities from their thermal limit in an out-of-equilibrium situation. The main focus lies on the thermalization pattern with which the various plasma constituents of different energies approach their final thermal distribution as the coupling constant decreases from the infinite coupling limit. All results point towards the weakening of the usual top down thermalization pattern.

Stefan Stricker

2014-03-11T23:59:59.000Z

291

HEATS: Thermal Energy Storage  

SciTech Connect (OSTI)

HEATS Project: The 15 projects that make up ARPA-E’s 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

292

The importance of anharmonicity in thermal transport across solid-solid interfaces  

SciTech Connect (OSTI)

Understanding interfacial thermal transport is of great importance for applications like energy devices and thermal management of electronics. Despite the significant efforts in the past few decades, thermal transport across solid-solid interfaces is still not fully understood and cannot be accurately predicted. Anharmonicity is often ignored in many prediction models, such as the mismatch models, the wave-packet method, and the Atomic Green's function. In this paper, we use molecular dynamics to systematically study the role of anharmonicity in thermal transport across solid-solid interfaces. The interatomic interactions are modeled using force constants up to the third order. This model allows controlling the anharmonicity independently by tuning the cubic force constants. The interfacial thermal conductance as a function of anharmonicity inside the materials and that at the interface is studied. We found that the anharmonicity inside the materials plays an important role in the interfacial thermal transport by facilitating the energy communication between different phonon modes. The anharmonicity at the interface has much less impact on the interfacial thermal transport. These results are important to the modification of traditional models to improve their prediction power.

Wu, Xufei [Aerospace and Mechanical Engineering, University of Notre Dame, 371 Fitzpatrick Hall-Notre Dame, Indiana 46556 (United States); Luo, Tengfei, E-mail: tluo@nd.edu [Aerospace and Mechanical Engineering, University of Notre Dame, 371 Fitzpatrick Hall-Notre Dame, Indiana 46556 (United States); Center for Sustainable Energy at Notre Dame, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2014-01-07T23:59:59.000Z

293

Thermal emission in the ultrastrong coupling regime  

E-Print Network [OSTI]

We study thermal emission of a cavity quantum electrodynamic system in the ultrastrong-coupling regime where the atom-cavity coupling rate becomes comparable the cavity resonance frequency. In this regime, the standard descriptions of photodetection and dissipation fail. Following an approach that was recently put forward by Ridolfo et al.[arXiv:1206.0944], we are able to calculate the emission of systems with arbitrary strength of light matter interaction, by expressing the electric field operator in the cavity-emitter dressed basis. Here we present thermal photoluminescence spectra, calculated for given temperatures and for different couplings in particular for available circuit QED parameters.

A. Ridolfo; M. Leib; S. Savasta; M. J. Hartmann

2012-10-08T23:59:59.000Z

294

Kyler Nelson Light Timer  

E-Print Network [OSTI]

designated by the user, the Arduino board will dim the light to save energy. The user designates the time instance, the light is dimmed using pulse width modulation (PWM) in the Arduino's pin number 11

Kachroo, Pushkin

295

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

296

AIRPORT LIGHTING Session Highlights  

E-Print Network [OSTI]

AIRPORT LIGHTING Session Highlights In May 2002, the Airport Technical Assistance Program, also known as AirTAP, sponsored three airport-lighting training sessions at different locations in Minnesota information on airport lighting and navigational aid equipment selection, funding, maintenance, and operation

Minnesota, University of

297

Advanced Demand Responsive Lighting  

E-Print Network [OSTI]

Advanced Demand Responsive Lighting Host: Francis Rubinstein Demand Response Research Center demand responsive lighting systems ­ Importance of dimming ­ New wireless controls technologies · Advanced Demand Responsive Lighting (commenced March 2007) #12;Objectives · Provide up-to-date information

298

Light emitting device comprising phosphorescent materials for white light generation  

DOE Patents [OSTI]

The present invention relates to phosphors for energy downconversion of high energy light to generate a broadband light spectrum, which emit light of different emission wavelengths.

Thompson, Mark E.; Dapkus, P. Daniel

2014-07-22T23:59:59.000Z

299

Light Duty Combustion Research: Advanced Light-Duty Combustion...  

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

Combustion Research: Advanced Light-Duty Combustion Experiments Light Duty Combustion Research: Advanced Light-Duty Combustion Experiments 2009 DOE Hydrogen Program and Vehicle...

300

Thermal Processes | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Hydrogen Production Current Technology Thermal Processes Thermal Processes Some thermal processes use the energy in various resources, such as natural gas, coal, or biomass,...

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


301

Multiwavelength Thermal Emission  

E-Print Network [OSTI]

Multiwavelength Astronomy NASA #12;Thermal Emission #12;Thermal Emission Non-thermal p-p collisions Optical IR Radio/ Microwave sources of emission massive stars, WHIM, Ly many dust, cool objects-ray ~GeV Gamma-ray ~TeV sources of emission AGN, clusters, SNR, binaries, stars AGN (obscured), shocks

California at Santa Cruz, University of

302

Thermal Performance Benchmarking (Presentation)  

SciTech Connect (OSTI)

This project will benchmark the thermal characteristics of automotive power electronics and electric motor thermal management systems. Recent vehicle systems will be benchmarked to establish baseline metrics, evaluate advantages and disadvantages of different thermal management systems, and identify areas of improvement to advance the state-of-the-art.

Moreno, G.

2014-11-01T23:59:59.000Z

303

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

304

Photonic crystal light source  

DOE Patents [OSTI]

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)

2004-07-27T23:59:59.000Z

305

Holographic thermalization and gravitational collapse in the spacetime dominated by quintessence dark energy  

E-Print Network [OSTI]

In this paper, the thermalization has been studied holographically. Explicitly in the gravity side, we consider the gravitational collapse of a thin shell of dust in a spacetime dominated by quintessence dark energy. With the thermalization probes such as the normalized geodesic length and minimal area surface, we study the effect of the state parameter for the quintessence dark energy on the thermalization. Our results show that the smaller the state parameter of quintessence is, the harder the plasma to thermalize. We also investigate the thermalization velocity and thermalization acceleration. We hope our results here can shed light on the nature of the quintessence dark energy.

Xiao-Xiong Zeng; De-You Chen; Li-Fang Li

2014-12-21T23:59:59.000Z

306

An Innovative High Thermal Conductivity Fuel Design  

SciTech Connect (OSTI)

Thermal conductivity of the fuel in today's Light Water Reactors, Uranium dioxide, can be improved by incorporating a uniformly distributed heat conducting network of a higher conductivity material, Silicon Carbide. The higher thermal conductivity of SiC along with its other prominent reactor-grade properties makes it a potential material to address some of the related issues when used in UO2 [97% TD]. This ongoing research, in collaboration with the University of Florida, aims to investigate the feasibility and develop a formal methodology of producing the resultant composite oxide fuel. Calculations of effective thermal conductivity of the new fuel as a function of %SiC for certain percentages and as a function of temperature are presented as a preliminary approach. The effective thermal conductivities are obtained at different temperatures from 600K to 1600K. The corresponding polynomial equations for the temperature-dependent thermal conductivities are given based on the simulation results. Heat transfer mechanism in this fuel is explained using a finite volume approach and validated against existing empirical models. FLUENT 6.1.22 was used for thermal conductivity calculations and to estimate reduction in centerline temperatures achievable within such a fuel rod. Later, computer codes COMBINE-PC and VENTURE-PC were deployed to estimate the fuel enrichment required, to maintain the same burnup levels, corresponding to a volume percent addition of SiC.

Jamil A. Khan

2009-11-21T23:59:59.000Z

307

Light extraction from organic light-emitting diodes for lighting applications by sand-blasting  

E-Print Network [OSTI]

Light extraction from organic light-emitting diodes for lighting applications by sand@ust.hk Abstract: Light extraction from organic light-emitting diodes (OLEDs) by scattering the light is one of the effective methods for large-area lighting applications. In this paper, we present a very simple and cost

308

Phonon Heat Conduction in Corrugated Silicon Nanowires Below the Casimir Limit Christophe Blanc,1  

E-Print Network [OSTI]

very low thermal conductances of highly rough silicon nanowires [7, 18], far below the amorphous limit, 2013) The thermal conductance of straight and corrugated monocrystalline silicon nanowires has been of nanostructured materials or low dimen- sional materials has attracted growing interest [1­4], es- pecially

Paris-Sud XI, Université de

309

SMART LIGHTING SYSTEMS ULTIMATE LIGHTING The Smart Lighting  

E-Print Network [OSTI]

Integration (Holistic Integrated Design) · Sensors as important as LEDs · Interconnected systems (human, building, grid) · Artistic Design Freedom · Lighting is Health, Entertainment, Information and Illumination Cost at any brightness · Chip level integrated electronics THE ERC RESEARCH COVERS THE ENTIRE SUPPLY

Linhardt, Robert J.

310

Interfacial electron and phonon scattering processes in high-powered nanoscale applications.  

SciTech Connect (OSTI)

The overarching goal of this Truman LDRD project was to explore mechanisms of thermal transport at interfaces of nanomaterials, specifically linking the thermal conductivity and thermal boundary conductance to the structures and geometries of interfaces and boundaries. Deposition, fabrication, and post possessing procedures of nanocomposites and devices can give rise to interatomic mixing around interfaces of materials leading to stresses and imperfections that could affect heat transfer. An understanding of the physics of energy carrier scattering processes and their response to interfacial disorder will elucidate the potentials of applying these novel materials to next-generation high powered nanodevices and energy conversion applications. An additional goal of this project was to use the knowledge gained from linking interfacial structure to thermal transport in order to develop avenues to control, or 'tune' the thermal transport in nanosystems.

Hopkins, Patrick E.

2011-10-01T23:59:59.000Z

311

Physics of band-gap formation and its evolution in the pillar-based phononic crystal structures  

SciTech Connect (OSTI)

In this paper, the interplay of Bragg scattering and local resonance is theoretically studied in a phononic crystal (PnC) structure composed of a silicon membrane with periodic tungsten pillars. The comparison of phononic band gaps (PnBGs) in three different lattice types (i.e., square, triangular, and honeycomb) with different pillar geometries shows that different PnBGs have varying degrees of dependency on the lattice symmetry based on the interplay of the local resonances and the Bragg effect. The details of this interplay is discussed. The significance of locally resonating pillars, specially in the case of tall pillars, on PnBGs is discussed and verified by examining the PnBG position and width in perturbed lattices via Monte Carlo simulations. It is shown that the PnBGs caused by the local resonance of the pillars are more resilient to the lattice perturbations than those caused by Bragg scattering.

Pourabolghasem, Reza; Mohammadi, Saeed; Eftekhar, Ali Asghar; Adibi, Ali [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Khelif, Abdelkrim [Institut FEMTO-ST, Université de Franche-Comté, CNRS, 32 Avenue de l'Observatoire, 25044 Besançon Cedex (France)

2014-07-07T23:59:59.000Z

312

Evidence for coupling between collective state and phonons in two-dimensional charge-density-wave systems  

SciTech Connect (OSTI)

We report on a Raman scattering investigation of the charge-density-wave (CDW), quasi two-dimensional rare-earth tri-tellurides RTe{sub 3} (R = La, Ce, Pr, Nd, Sm, Gd and Dy) at ambient pressure, and of LaTe{sub 3} and CeTe{sub 3} under externally applied pressure. The observed phonon peaks can be ascribed to the Raman active modes for both the undistorted as well as the distorted lattice in the CDW state by means of a first principles calculation. The latter also predicts the Kohn anomaly in the phonon dispersion, driving the CDW transition. The integrated intensity of the two most prominent modes scales as a characteristic power of the CDW-gap amplitude upon compressing the lattice, which provides clear evidence for the tight coupling between the CDW condensate and the vibrational modes.

Lavagnini, M.; /Zurich, ETH; Baldini, M.; /INFN, Rome; Sacchetti, A.; /Zurich, ETH; Castro, D.Di; /Zurich, ETH; Delley, B.; /PSI, Villigen; Monnier, R.; /Zurich, ETH; Chu, J.-H.; Ru, N.; Fisher, I.R.; /Stanford U., Geballe Lab.; Postorino, P.; /INFN, Rome; Degiorgi, L.; /Zurich, ETH

2010-02-15T23:59:59.000Z

313

Influence of longitudinal isotope substitution on the thermal conductivity of carbon nanotubes: Results of nonequilibrium molecular dynamics and local density functional calculations  

SciTech Connect (OSTI)

We report reverse nonequilibrium molecular dynamics calculations of the thermal conductivity of isotope substituted (10,10) carbon nanotubes (CNTs) at 300 K. {sup 12}C and {sup 14}C isotopes both at 50% content were arranged either randomly, in bands running parallel to the main axis of the CNTs or in bands perpendicular to this axis. It is found that the systems with randomly distributed isotopes yield significantly reduced thermal conductivity. In contrast, the systems where the isotopes are organized in patterns parallel to the CNTs axis feature no reduction in thermal conductivity when compared with the pure {sup 14}C system. Moreover, a reduction of approximately 30% is observed in the system with the bands of isotopes running perpendicular to the CNT axis. The computation of phonon dispersion curves in the local density approximation and classical densities of vibrational states reveal that the phonon structure of carbon nanotubes is conserved in the isotope substituted systems with the ordered patterns, yielding high thermal conductivities in spite of the mass heterogeneity. In order to complement our conclusions on the {sup 12}C-{sup 14}C mixtures, we computed the thermal conductivity of systems where the {sup 14}C isotope was turned into pseudo-atoms of 20 and 40 atomic mass units.

Leroy, Frédéric, E-mail: f.leroy@theo.chemie.tu-darmstadt.de; Böhm, Michael C., E-mail: boehm@theo.chemie.tu-darmstadt.de [Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt (Germany); Schulte, Joachim [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany)] [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany); Balasubramanian, Ganesh [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)] [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2014-04-14T23:59:59.000Z

314

Intensity-Intensity Correlations of Classically Entangled Light  

E-Print Network [OSTI]

An experiment is proposed to show that after initial frequency and polarization selection, classical thermal light from two independent sources can be made path-polarization entangled. Such light will show new intensity-intensity correlations involving both path and polarization phases, formally similar to those for four-particle GHZ states. For fixed polarization phases, the correlations reduce to the Hanbury Brown-Twiss phase correlations. It is also shown that these classical correlations violate noncontextuality.

Partha Ghose; Anirban Mukherjee

2014-01-03T23:59:59.000Z

315

Arnold Schwarzenegger LIGHTING RESEARCH PROGRAM  

E-Print Network [OSTI]

Project Summaries ELEMENT 2: ADVANCE LIGHTING TECHNOLOGIES PROJECT 2.1 LIGHT EMITTING DIODE (LED light emitting diodes (LED) technology for general lighting applications by developing a task lamp

316

Phonon mediated spin relaxation in a moving quantum dot: Doppler shift, Cherenkov radiation, and spin relaxation boom  

E-Print Network [OSTI]

We study relaxation of a moving spin qubit caused by phonon noise. As we vary the speed of the qubit, we observe several interesting features in spin relaxation and the associated phonon emission, induced by Doppler effect. In particular, in the supersonic regime, the phonons emitted by the relaxing qubit is concentrated along certain directions, similar to the shock waves produced in classical Cherenkov effect. As the speed of the moving qubit increases from the subsonic regime to the supersonic regime, the qubit experiences a peak in the spin relaxation rate near the speed of sound, which we term a spin relaxation boom in analogy to the classical sonic boom. We also find that the moving spin qubit may have a lower relaxation rate than a static qubit, which hints at the possibility of coherence-preserving transportation for a spin qubit. While the physics we have studied here has strong classical analogies, we do find that quantum confinement for the spin qubit plays an important role in all the phenomena we observe. Specifically, it produces a correction on the Cherenkov angle, and removes the divergence in relaxation rate at the sonic barrier. It is our hope that our results would encourage further research into approaches for transferring and preserving quantum information in spin qubit architectures.

Xinyu Zhao; Peihao Huang; Xuedong Hu

2015-02-27T23:59:59.000Z

317

New Light Sources for Tomorrow's Lighting Designs  

E-Print Network [OSTI]

, pioneered for headlam~for the automotive industry, has led to the development of halo en capsule lamps for general lighting. The original90-watt family PAR 38 lamps using tungsten halogen capsules produces the sa amount of useful light in the beam as a I... quartz PAR lamps with similar benefi . Each of these tungsten halogen capsule PAR wattages are av ilable in narrow spot, spot, and flood beam patterns. The most recent developments in the PAR halogen psule family include two entirely new lamp designs...

Krailo, D. A.

318

National Synchrotron Light Source  

ScienceCinema (OSTI)

A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

BNL

2009-09-01T23:59:59.000Z

319

LED Lighting Retrofit  

E-Print Network [OSTI]

? Municipal Street Lighting Consortium ? American Public Power Association (APPA) ? Demonstration in Energy Efficiency Development (DEED) ? Source of funding and database of completed LED roadway projects 6 Rules of the Road ESL-KT-11-11-57 CATEE 2011..., 2011 ? 9 Solar-Assisted LED Case Study LaQuinta Hotel, Cedar Park, Texas ? Utilizes 18 - ActiveLED Solar-Assisted Parking Lot Lights ? Utilizes ?power management? to extend battery life while handling light output ? Reduces load which reduces PV...

Shaw-Meadow, N.

2011-01-01T23:59:59.000Z

320

Total Light Management  

Broader source: Energy.gov [DOE]

Presentation covers total light management, and is given at the Spring 2010 Federal Utility Partnership Working Group (FUPWG) meeting in Providence, Rhode Island.

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Lighting Technology Panel  

Broader source: Energy.gov [DOE]

Presentation covers the Lighting Technology Panel for the Federal Utility Partnership Working Group (FUPWG) meeting, held on November 18-19, 2009. 

322

Comparing Light Bulbs  

Broader source: Energy.gov [DOE]

In this exercise, students will use a light to demonstrate the difference between being energy-efficient and energy-wasteful, and learn what energy efficiency means.

323

Solid-State Lighting  

Broader source: Energy.gov (indexed) [DOE]

research and design. Quality LED luminaires require program designed to successfully move solid-state lighting precise design of several components -LED arrays, electronic into the...

324

Low-temperature thermal conductivity of antiferromagnetic S?=?1/2 chain material CuCl{sub 2}·2((CH{sub 3}){sub 2}SO)  

SciTech Connect (OSTI)

We study the heat transport of S?=?1/2 chain compound CuCl{sub 2}·2((CH{sub 3}){sub 2}SO) along the b axis (vertical to the chain direction) at very low temperatures. The zero-field thermal conductivity (?) shows a distinct kink at about 0.9?K, which is related to the long-range antiferromagnetic (AF) transition. With applying magnetic field along the c axis, ?(H) curves also show distinct changes at the phase boundaries between the AF and the high-field disordered states. These results indicate a strong spin-phonon interaction and the magnetic excitations play a role in the b-axis heat transport as phonon scatterers.

Ke, W. P.; Zhang, F. B.; Zhao, Z. Y.; Fan, C.; Sun, X. F., E-mail: xfsun@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Shi, J. [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhao, X., E-mail: xiazhao@ustc.edu.cn [School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-05-07T23:59:59.000Z

325

Mass-density and Phonon-frequency Relaxation Dynamics of Water and Ice at Cooling  

E-Print Network [OSTI]

Coulomb repulsion between the bonding electron pair in the H-O covalent bond (denoted by "-") and the nonbonding electron pair of O (":") and the specific-heat disparity between the O:H and the H-O segments of the entire hydrogen bond (O:H-O) are shown to determine the O:H-O bond angle-length-stiffness relaxation dynamics and the density anomalies of water and ice. The bonding part with relatively lower specific-heat is more easily activated by cooling, which serves as the "master" and contracts, while forcing the "slave" with higher specific-heat to elongate (via Coulomb repulsion) by different amounts. In the liquid and solid phases, the O:H van der Waals bond serves as the master and becomes significantly shorter and stiffer while the H-O bond becomes slightly longer and softer (phonon frequency is a measure of bond stiffness), resulting in an O:H-O cooling contraction and the seemingly "regular" process of cooling densification. In the water-ice transition phase, the master and the slave swap roles, thus resulting in an O:H-O elongation and volume expansion during freezing. In ice, the O--O distance is longer than it is in water, resulting in a lower density, so that ice floats.

Chang Q. Sun

2013-04-02T23:59:59.000Z

326

Compressibilities and phonon spectra of high-hardness transition metal-nitride materials  

SciTech Connect (OSTI)

We report compressibilities measured by synchrotron X-ray diffraction and phonon spectra from Raman scattering at high pressure in the diamond anvil cell (DAC) for cubic transition metal nitrides TiN{sub 1-x}, {gamma}-Mo{sub 2}N and VN{sub x}. The high-hardness metal nitride compounds have large values of the bulk modulus. B1-structured nitrides normally have no allowed first-order Raman spectra. However, they exhibit broad bands that reflect the vibrational density of states g({omega}) associated with breakdown of q=0 selection rules because of the presence of N{sup 3-} vacancies on anion sites. Peaks in g({omega}) at low frequency are identified with the longitudinal and transverse acoustic (TA) branches. The maximum in the TA band is correlated with the superconducting transition temperature in these materials (T{sub c}). In situ Raman scattering measurements in the DAC thus permit predictions of the T{sub c} variation with pressure for cubic nitrides and isostructural carbide materials.

Shebanova, O.; Soignard, E.; Mcmillan, P.F. (ASU); (UCL)

2010-01-20T23:59:59.000Z

327

Taunton Municipal Lighting Plant- Residential and Non-Profit Weatherization Program (Massachusetts)  

Broader source: Energy.gov [DOE]

Taunton Municipal Lighting Plant (TMLP) offers the 'House N Home' Thermal Rebate Program which provides financial incentives to residential and non-Profit customers for making buildings more energy...

328

Light-Weight, Low-Cost, Single-Phase, Liquid-Cooled Cold Plate (Presentation)  

SciTech Connect (OSTI)

This presentation, 'Light-Weight, Low-Cost, Single-Phase Liquid-Cooled Cold Plate,' directly addresses program goals of increased power density, specific power, and lower cost of power electronics components through improved thermal management.

Narumanchi, S.

2013-07-01T23:59:59.000Z

329

Light-Weight, Single-Phase, Liquid-Cooled Cold Plate (Presentation)  

SciTech Connect (OSTI)

This presentation, 'Light-Weight, Low-Cost, Single-Phase Liquid-Cooled Cold Plate,' directly addresses program goals of increased power density, specific power, and lower cost of power electronics components through improved thermal management.

Narumanchi, S.

2013-07-01T23:59:59.000Z

330

Thermal Conduction in Suspended Graphene Layers A. A.BALANDIN, S. GHOSH, D. L. NIKA AND E. P. POKATILOV  

E-Print Network [OSTI]

' properties. Materials with very high or very low thermal conductivities attract particular attention due and engineering research communities to the thermal conductivity of materials. This is explained by both in its atomic structure and the knowledge of thermal conductivity can shed light on many other materials

331

Thermal comfort during surgery  

E-Print Network [OSTI]

THERMAL COMFORT DURING SURGERY A Thesis by DAVID HAROLD MANNING Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1978 Major Subject: Industrial... Engineering THERMAL COMFORT DURING SURGERY A Thesis by DAVID HAROLD MANNING Approved as to style and content by: airman of C it ee Head of Department Member Me er December 1978 ABSTRACT Thermal Comfort During Surgery (December 1978) David Harold...

Manning, David Harold

1978-01-01T23:59:59.000Z

332

Thermal Infrared Remote Sensing  

E-Print Network [OSTI]

Thermal Infrared Remote Sensing Thermal Infrared Remote Sensing #12;0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4 and x-ray Ultraviolet Infrared Microwave and radio waves Wavelength in meters (m) Electromagnetic.77 700 red limit 30k0.041 2.48 green500 near-infrared far infrared ultraviolet Thermal Infrare refers

333

Detecting coherent phonon wave effects in superlattices using time-domain thermoreflectance  

E-Print Network [OSTI]

Superlattices (SLs), structures consisting of periodic layers of thin films of several angstroms to tens of nanometers thick, have unique electrical and thermal properties that make them well suited for applications in ...

Luckyanova, Maria N. (Maria Nickolayevna)

2012-01-01T23:59:59.000Z

334

OpenGL Lighting 13. OpenGL Lighting  

E-Print Network [OSTI]

OpenGL Lighting 13. OpenGL Lighting · Overview of Lighting in OpenGL In order for lighting to have an effect in OpenGL, two things are required: A light An object to be lit Lights can be set to any color determine how they reflect the light which hits them. The color(s) of an object is determined

McDowell, Perry

335

Light intensity compressor  

DOE Patents [OSTI]

In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

Rushford, Michael C. (Livermore, CA)

1990-01-01T23:59:59.000Z

336

Splayed mirror light pipes  

SciTech Connect (OSTI)

An expression is given for the transmission of the rectangular-section mirror light pipe. The expression is used to model throughputs for simulated solar conditions over a calender year. It is found that the splaying of a mirror light pipe results in a significant increase in throughputs particularly in winter months. (author)

Swift, P.D. [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

2010-02-15T23:59:59.000Z

337

Explosively pumped laser light  

DOE Patents [OSTI]

A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

Piltch, Martin S. (Los Alamos, NM); Michelotti, Roy A. (Los Alamos, NM)

1991-01-01T23:59:59.000Z

338

Reducing home lighting expenses  

SciTech Connect (OSTI)

Ways to reduce lighting expenses are summarized. These include: turning off lights when not in use; keeping fixtures and lamps clean; replacing lamps with more efficient types; using three-way bulbs; use of daylighting; buying fewer lamps and reducing lamp wattage; consider repainting rooms; replacing recessed fixtures with tracklighting; and using efficient lamps for outdoor use. (MCW)

Aimone, M.A.

1981-02-01T23:59:59.000Z

339

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

340

NANO REVIEW Open Access Thermal conductivity and thermal boundary  

E-Print Network [OSTI]

NANO REVIEW Open Access Thermal conductivity and thermal boundary resistance of nanostructures and the thermal transport prop- erties is a key point to design materials with preferred thermal properties with the heat dissipation on them. The influence of the interfacial roughness on the thermal conductivity

Boyer, Edmond

Note: This page contains sample records for the topic "lighting phonons thermal" 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

The thermal performance of fixed and variable selective transmitters in commercial architecture  

E-Print Network [OSTI]

A parametric model is developed for use in evaluating the relative thermal and lighting performance of a variety of existing and proposed types of commercial glazing materials. The glazing materials considered are divided ...

Bartovics, William A

1984-01-01T23:59:59.000Z

342

NEUTRONIC AND THERMAL HYDRAULIC DESIGNS OF ANNULAR FUEL FOR HIGH POWER DENSITY BWRS  

E-Print Network [OSTI]

As a promising new fuel for high power density light water reactors, the feasibility of using annular fuel for BWR services is explored from both thermal hydraulic and neutronic points of view. Keeping the bundle size ...

Morra, P.

343

VIRTUAL LIGHT: DIGITALLY-GENERATED LIGHTING FOR VIDEO CONFERENCING APPLICATIONS  

E-Print Network [OSTI]

VIRTUAL LIGHT: DIGITALLY-GENERATED LIGHTING FOR VIDEO CONFERENCING APPLICATIONS Andrea Basso method to improve the lighting conditions of a real scene or video sequence. In particular we concentrate on modifying real light sources intensities and inserting virtual lights into a real scene viewed from a fixed

Fisher, Kathleen

344

Lighting affects appearance LightSource emits photons  

E-Print Network [OSTI]

1 Lighting affects appearance #12;2 LightSource emits photons Photons travel in a straight line). And then some reach the eye/camera. #12;3 Reflectance Model how objects reflect light. Model light sources Algorithms for computing Shading: computing intensities within polygons Determine what light strikes what

Jacobs, David

345

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

346

Mechanical Engineering & Thermal Group  

E-Print Network [OSTI]

Mechanical Engineering & Thermal Group The Mechanical Engineering (ME) & Thermal Group at LASP has, and ground- based mechanical systems. Instrument Design Building on decades of design experience that has evolved with the complexity of instrument design demands, LASP mechanical engineers develop advanced

Mojzsis, Stephen J.

347

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

348

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

349

Tunable thermal link  

DOE Patents [OSTI]

Disclosed is a device whereby the thermal conductance of a multiwalled nanostructure such as a multiwalled carbon nanotube (MWCNT) can be controllably and reversibly tuned by sliding one or more outer shells with respect to the inner core. As one example, the thermal conductance of an MWCNT dropped to 15% of the original value after extending the length of the MWCNT by 190 nm. The thermal conductivity returned when the tube was contracted. The device may comprise numbers of multiwalled nanotubes or other graphitic layers connected to a heat source and a heat drain and various means for tuning the overall thermal conductance for applications in structure heat management, heat flow in nanoscale or microscale devices and thermal logic devices.

Chang, Chih-Wei; Majumdar, Arunava; Zettl, Alexander K.

2014-07-15T23:59:59.000Z

350

Thermal Recovery Methods  

SciTech Connect (OSTI)

Thermal Recovery Methods describes the basic concepts of thermal recovery and explains the injection patterns used to exploit reservoir conditions. Basic reservoir engineering is reviewed with an emphasis on changes in flow characteristics caused by temperature. The authors discuss an energy balance for steam and combustion drive, and they explain in situ reactions. Heat loss, combustion drive, and steam displacement also are examined in detail, as well as cyclic steam injection, downhole ignition, well heating, and low-temperature oxidation. Contents: Thermal processes; Formation and reservoir evaluations; Well patterns and spacing; Flow and process equations; Laboratory simulation of thermal recovery; Heat loss and transmission; Displacement and production; Equipment; Basic data for field selection; Laboratory evaluation of combustion characteristics; Thermal properties of reservoirs and fluids.

White, P.D.; Moss, J.T.

1983-01-01T23:59:59.000Z

351

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

352

PHYSICAL REVIEW B 85, 035438 (2012) Enhancing and tuning phonon transport at vibrationally mismatched solid-solid interfaces  

E-Print Network [OSTI]

role in defining the thermal properties of nanostructured materials in which heat transfer thermal conductance associated with interface scattering by adding more material along the direction, and RBD is an equivalent thermal resistance. The fact that hBD has become the limiting thermal conductance

Zhigilei, Leonid V.

353

Scattering Solar Thermal Concentrators  

Broader source: Energy.gov (indexed) [DOE]

is a rendering of a scattering solar concentrator. Light collected by a cylindrical Fresnel lens is focused within a curved glass "guide" sheet, where it is redirected into...

354

Phonon-roton modes of liquid 4He beyond the roton in MCM-41  

SciTech Connect (OSTI)

We present neutron scattering measurements of the phonon-roton (P-R) mode of superfluid 4He confined in 47 A MCM-41 at T = 0.5 K at wave vectors, Q, beyond the roton wave vector (QR = 1.92 A-1). Measurements beyond the roton require access to high wave vectors (up to Q = 4 A-1) with excellent energy resolution and high statistical precision. The present results show for the first time that at T = 0.5 K the P-R mode in MCM-41 extends out to wave-vector Q 3.6 A-1 with the same energy and zero width (within precision) as observed in bulk superfluid 4He. Layer modes in the roton region are also observed. Specifically, the P-R mode energy, !Q, increases with Q for Q > QR and reaches a plateau at a maximum energy !Q = 2 where is the roton energy, = 0.74 0.01 meV in MCM-41. This upper limit means the P-R mode decays to two rotons when its energy exceeds 2 . It also means that the P-R mode does not decay to two layers modes. If the P-R could decay to two layer modes, !Q would plateau at a lower energy, !Q = 2 L where L = 0.60 meV is the energy of the roton like minimum of the layer mode. The observation of the P-R mode with energy up to 2 shows that the P-R mode and the layer modes are independent modes with apparently little interaction between them.

Azuah, Richard T [NIST Center for Neutron Research (NCRN), Gaithersburg, MD] NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Omar Diallo, Souleymane [ORNL] ORNL; Adams, Mark A. [ISIS Facility, Rutherford Appleton Laboratory (ISIS)] ISIS Facility, Rutherford Appleton Laboratory (ISIS); Kirichek, Oleg [ISIS Facility, Rutherford Appleton Laboratory (ISIS)] ISIS Facility, Rutherford Appleton Laboratory (ISIS); Glyde, Henry R [University of Delaware] University of Delaware

2013-01-01T23:59:59.000Z

355

Green Light Pulse Oximeter  

DOE Patents [OSTI]

A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

Scharf, John Edward (Oldsmar, FL)

1998-11-03T23:59:59.000Z

356

White light velocity interferometer  

DOE Patents [OSTI]

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

Erskine, David J. (Oakland, CA)

1997-01-01T23:59:59.000Z

357

White light velocity interferometer  

DOE Patents [OSTI]

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

Erskine, D.J.

1997-06-24T23:59:59.000Z

358

White light velocity interferometer  

DOE Patents [OSTI]

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

Erskine, David J. (Oakland, CA)

1999-01-01T23:59:59.000Z

359

White light velocity interferometer  

DOE Patents [OSTI]

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

Erskine, D.J.

1999-06-08T23:59:59.000Z

360

Optical device with low electrical and thermal resistance bragg reflectors  

DOE Patents [OSTI]

A compound-semiconductor optical device and method. The optical device is provided with one or more asymmetrically-graded heterojunctions between compound semiconductor layers for forming a distributed Bragg reflector mirror having an improved electrical and thermal resistance. Efficient light-emitting devices such as light-emitting diodes, resonant-cavity light-emitting diodes, and vertical-cavity surface-emitting lasers may be formed according to the present invention, which may be applied to the formation of resonant-cavity photodetectors.

Lear, Kevin L. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Lakeview Light and Power- Commercial Lighting Rebate Program  

Broader source: Energy.gov [DOE]

Lakeview Light and Power offers a commercial lighting rebate program. Rebates apply to the installation of energy efficient lighting retrofits in non-residential buildings. The rebate program is...

362

Light Duty Efficient, Clean Combustion  

SciTech Connect (OSTI)

Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy's Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of the following objectives were met with fuel efficiency improvement targets exceeded: (1) Improve light duty vehicle (5000 lb. test weight) fuel efficiency by 10.5% over today's state-of-the-art diesel engine on the FTP city drive cycle; (2) Develop and design an advanced combustion system plus aftertreatment system that synergistically meets Tier 2 Bin 5 NOx and PM emissions standards while demonstrating the efficiency improvements; (3) Maintain power density comparable to that of current conventional engines for the applicable vehicle class; and (4) Evaluate different fuel components and ensure combustion system compatibility with commercially available biofuels. Key accomplishments include: (1) A 25% improvement in fuel efficiency was achieved with the advanced LDECC engine equipped with a novel SCR aftertreatment system compared to the 10.5% target; (2) An 11% improvement in fuel efficiency was achieved with the advanced LDECC engine and no NOx aftertreamtent system; (3) Tier 2 Bin 5 and SFTP II emissions regulations were met with the advanced LDECC engine equipped with a novel SCR aftertreatment system; (4) Tier 2 Bin 5 emissions regulations were met with the advanced LDECC engine and no NOx aftertreatment, but SFTP II emissions regulations were not met for the US06 test cycle - Additional technical barriers exist for the no NOx aftertreatment engine; (5) Emissions and efficiency targets were reached with the use of biodiesel. A variety of biofuel feedstocks (soy, rapeseed, etc.) was investigated; (6) The advanced LDECC engine with low temperature combustion was compatible with commercially available biofuels as evaluated by engine performance testing and not durability testing; (7) The advanced LDECC engine equipped with a novel SCR aftertreatment system is the engine system architecture that is being further developed by the Cummins product development organization. Cost reduction and system robustness activities have been identified for future deployment; (8) The new engine and aftertreatment component technologies are being developed by the Cummins Component Business units (e.g. fuel system, turbomachinery, aftertreatment, electronics, etc.) to ensure commercial viability and deployment; (9) Cummins has demonstrated that the technologies developed for this program are scalable across the complete light duty engine product offerings (2.8L to 6.7L engines); and (10) Key subsystems developed include - sequential two stage turbo, combustions system for low temperature combustion, novel SCR aftertreatment system with feedback control, and high pressure common rail fuel system. An important element of the success of this project was leveraging Cummins engine component technologies. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 40% improvement in thermal efficiency for the engine plus aftertreatment system. The 40% improvement is in-line with the current light duty vehicle efficiency targets set by the 2010 DoE Vehicle Technologies MYPP and supported through co-operative projects such as the Cummins Advanced Technology Powertrains for Light-Duty Vehicles (ATP-LD) started in 2010.

Donald Stanton

2010-12-31T23:59:59.000Z

363

Light Duty Efficient, Clean Combustion  

SciTech Connect (OSTI)

Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy’s Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of the following objectives were met with fuel efficiency improvement targets exceeded: 1. Improve light duty vehicle (5000 lb. test weight) fuel efficiency by 10.5% over today’s state-ofthe- art diesel engine on the FTP city drive cycle 2. Develop & design an advanced combustion system plus aftertreatment system that synergistically meets Tier 2 Bin 5 NOx and PM emissions standards while demonstrating the efficiency improvements. 3. Maintain power density comparable to that of current conventional engines for the applicable vehicle class. 4. Evaluate different fuel components and ensure combustion system compatibility with commercially available biofuels. Key accomplishments include: ? A 25% improvement in fuel efficiency was achieved with the advanced LDECC engine equipped with a novel SCR aftertreatment system compared to the 10.5% target ? An 11% improvement in fuel efficiency was achieved with the advanced LDECC engine and no NOx aftertreamtent system ? Tier 2 Bin 5 and SFTP II emissions regulations were met with the advanced LDECC engine equipped with a novel SCR aftertreatment system ? Tier 2 Bin 5 emissions regulations were met with the advanced LDECC engine and no NOx aftertreatment, but SFTP II emissions regulations were not met for the US06 test cycle – Additional technical barriers exist for the no NOx aftertreatment engine ? Emissions and efficiency targets were reached with the use of biodiesel. A variety of biofuel feedstocks (soy, rapeseed, etc.) was investigated. ? The advanced LDECC engine with low temperature combustion was compatible with commercially available biofuels as evaluated by engine performance testing and not durability testing. ? The advanced LDECC engine equipped with a novel SCR aftertreatment system is the engine system architecture that is being further developed by the Cummins product development organization. Cost reduction and system robustness activities have been identified for future deployment. ? The new engine and aftertreatment component technologies are being developed by the Cummins Component Business units (e.g. fuel system, turbomachinery, aftertreatment, electronics, etc.) to ensure commercial viability and deployment ? Cummins has demonstrated that the technologies developed for this program are scalable across the complete light duty engine product offerings (2.8L to 6.7L engines) ? Key subsystems developed include – sequential two stage turbo, combustions system for low temperature combustion, novel SCR aftertreatment system with feedback control, and high pressure common rail fuel system An important element of the success of this project was leveraging Cummins engine component technologies. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 40% improvement in thermal efficiency for the engine plus aftertreatment system. The 40% improvement is in-line with the current light duty vehicle efficiency targets set by the 2010 DoE Vehicle Technologies MYPP and supported through co-operative projects such as the Cummins Advanced Technology Powertrains for Light- Duty Vehicles (ATP-LD) started in 2010.

Stanton, Donald W

2011-06-03T23:59:59.000Z

364

Prediction of Thermal Conductivity for Irradiated SiC/SiC Composites by Informing Continuum Models with Molecular Dynamics Data  

SciTech Connect (OSTI)

This article proposes a new method to estimate the thermal conductivity of SiC/SiC composites subjected to neutron irradiation. The modeling method bridges different scales from the atomic scale to the scale of a 2D SiC/SiC composite. First, it studies the irradiation-induced point defects in perfect crystalline SiC using molecular dynamics (MD) simulations to compute the defect thermal resistance as a function of vacancy concentration and irradiation dose. The concept of defect thermal resistance is explored explicitly in the MD data using vacancy concentrations and thermal conductivity decrements due to phonon scattering. Point defect-induced swelling for chemical vapor deposited (CVD) SiC as a function of irradiation dose is approximated by scaling the corresponding MD results for perfect crystal ?-SiC to experimental data for CVD-SiC at various temperatures. The computed thermal defect resistance, thermal conductivity as a function of grain size, and definition of defect thermal resistance are used to compute the thermal conductivities of CVD-SiC, isothermal chemical vapor infiltrated (ICVI) SiC and nearly-stoichiometric SiC fibers. The computed fiber and ICVI-SiC matrix thermal conductivities are then used as input for an Eshelby-Mori-Tanaka approach to compute the thermal conductivities of 2D SiC/SiC composites subjected to neutron irradiation within the same irradiation doses. Predicted thermal conductivities for an irradiated Tyranno-SA/ICVI-SiC composite are found to be comparable to available experimental data for a similar composite ICVI-processed with these fibers.

Nguyen, Ba Nghiep; Gao, Fei; Henager, Charles H.; Kurtz, Richard J.

2014-05-01T23:59:59.000Z

365

High-Temperature Thermal Array for Next Generation Solar Thermal...  

Broader source: Energy.gov (indexed) [DOE]

Thermal Array for Next Generation Solar Thermal Power Production Award Number: DE-EE00025828 Report Date: March 15, 2013 PI: Stephen Obrey * Technical approach is focused on...

366

Light Vector Mesons  

E-Print Network [OSTI]

This article reviews the current status of experimental results obtained in the measurement of light vector mesons produced in proton-proton and heavy ion collisions at different energies. The review is focused on two phenomena related to the light vector mesons; the modification of the spectral shape in search of Chiral symmetry restoration and suppression of the meson production in heavy ion collisions. The experimental results show that the spectral shape of light vector mesons are modified compared to the parameters measured in vacuum. The nature and the magnitude of the modification depends on the energy density of the media in which they are produced. The suppression patterns of light vector mesons are different from the measurements of other mesons and baryons. The mechanisms responsible for the suppression of the mesons are not yet understood. Systematic comparison of existing experimental results points to the missing data which may help to resolve the problem.

Alexander Milov

2008-12-21T23:59:59.000Z

367

National Synchrotron Light Source  

ScienceCinema (OSTI)

A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

None

2010-01-08T23:59:59.000Z

368

Efficient Light Sources Today  

E-Print Network [OSTI]

This paper reviews new lamp and lighting technology in terms of application and economic impact. Included are the latest advances in High Intensity Discharge systems, energy saving fluorescent lamps and ballasts, and the new state of the art high...

Hart, A. L.

1982-01-01T23:59:59.000Z

369

Natural lighting and skylights  

E-Print Network [OSTI]

outlined herein, the feasibility of using scale models for studying skylights is also an established fact. The method of analysis by models can be a valuable tool to any designer who is concerned about day-lighting....

Evans, Benjamin Hampton

1961-01-01T23:59:59.000Z

370

Reading Municipal Light Department- Business Lighting Rebate Program  

Broader source: Energy.gov [DOE]

Reading Municipal Light Department (RMLD) offers incentives for non-residential customers to install energy efficient lights and sensors in existing facilities. In addition to rebates for the...

371

Types of Lighting in Commercial Buildings - Lighting Characteristics  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

of a light source's accuracy in rendering different colors when compared to a reference light source. The highest attainable CRI is 100. Lamps with CRIs above 70 are...

372

Columbia Water and Light- HVAC and Lighting Efficiency Rebates  

Broader source: Energy.gov [DOE]

Columbia Water and Light (CWL) offers rebates to its commercial and industrial customers for the purchase of high efficiency HVAC installations and efficient lighting. Incentives for certain...

373

Induction Lighting: An Old Lighting Technology Made New Again...  

Broader source: Energy.gov (indexed) [DOE]

around the same time that his rival, Thomas Edison, was working to improve the incandescent light bulb. In the early 1990s, several major lighting manufacturers introduced...

374

Peninsula Light Company- Commercial Efficient Lighting Rebate Program  

Broader source: Energy.gov [DOE]

Peninsula Light Company (PLC) offers a rebate program for commercial customers who wish to upgrade to energy efficient lighting. Participating customers must be served by PLC commercial service....

375

Tungsten black absorber for solar light with wide angular operation range Eden Rephaeli1,a  

E-Print Network [OSTI]

Tungsten black absorber for solar light with wide angular operation range Eden Rephaeli1,a of Physics. DOI: 10.1063/1.2936997 In solar-thermal applications, one aims to convert sun- light to heat that displays near-complete absorptivity throughout the entire solar spectrum over a wide angular range

Fan, Shanhui

376

On the duration of the Paleocene-Eocene thermal maximum Ursula Rohl and Thomas Westerhold  

E-Print Network [OSTI]

On the duration of the Paleocene-Eocene thermal maximum (PETM) Ursula Ro¨hl and Thomas Westerhold of California, Santa Cruz, California 95064, USA [1] The Paleocene-Eocene thermal maximum (PETM) is one of global warming and a massive perturbation of the global carbon cycle from injection of isotopically light

Zachos, James

377

Light and Energy -Daylight measurements  

E-Print Network [OSTI]

Light and Energy - Daylight measurements #12;Light and Energy - Daylight measurements Authors: Jens;3 Title Light and Energy Subtitle Daylight measurements Authors Jens Christoffersen, Ásta Logadóttir ........................................................................................................ 5 Daylight quantity

378

Energy Conservation in Industrial Lighting  

E-Print Network [OSTI]

In order to reduce energy use in lighting Union Carbide recently issued drastically reduced new lighting level standards. A computerized lighting cost program was also developed. Using this program a number of additional energy saving techniques...

Meharg, E.

1979-01-01T23:59:59.000Z

379

Lighting and the Bottom Line  

E-Print Network [OSTI]

A discussion of the cost of light and how it relates to the cost of people. The new Illuminating Engineering Society recommended method of determining lighting levels will be explained. Also several ways of providing good lighting to increase...

Christensen, M.

1981-01-01T23:59:59.000Z

380

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

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Solar Thermal Conversion  

SciTech Connect (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

382

Enhancement of surface phonon modes in the Raman spectrum of ZnSe nanoparticles on adsorption of 4-mercaptopyridine  

SciTech Connect (OSTI)

By chemically etching a thin film of crystalline ZnSe with acid, we observe a strong Raman enhancement of the surface phonon modes of ZnSe on adsorption of a molecule (4-mercaptopyridine). The surface is composed of oblate hemi-ellipsoids, which has a large surface-to-bulk ratio. The assignment of the observed modes (at 248 and 492 cm{sup ?1}) to a fundamental and first overtone of the surface optical mode is consistent with observations from high-resolution electron energy loss spectroscopy as well as calculations.

Islam, Syed K.; Lombardi, John R. [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)] [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)

2014-02-21T23:59:59.000Z

383

Influence of Controlled Viscous Dissipation on the Propagation of Strongly Nonlinear Waves in Stainless Steel Based Phononic Crystals  

E-Print Network [OSTI]

Strongly nonlinear phononic crystals were assembled from stainless steel spheres. Single solitary waves and splitting of an initial pulse into a train of solitary waves were investigated in different viscous media using motor oil and non-aqueous glycerol to introduce a controlled viscous dissipation. Experimental results indicate that the presence of a viscous fluid dramatically altered the splitting of the initial pulse into a train of solitary waves. Numerical simulations qualitatively describe the observed phenomena only when a dissipative term based on the relative velocity between particles is introduced.

E. B. Herbold; V. F. Nesterenko; C. Daraio

2005-12-22T23:59:59.000Z

384

Light diffusing fiber optic chamber  

DOE Patents [OSTI]

A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

Maitland, Duncan J. (Lafayette, CA)

2002-01-01T23:59:59.000Z

385

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

386

Thermal excitation of plasmons for near-field thermophotovoltaics  

SciTech Connect (OSTI)

The traditional approaches of exciting plasmons consist of either using electrons (e.g., electron energy loss spectroscopy) or light (Kretchman and Otto geometry) while more recently plasmons have been excited even by single photons. A different approach: thermal excitation of a plasmon resonance at high temperatures using alternate plasmonic media was proposed by S. Molesky et al. [Opt. Express 21, A96–A110 (2013)]. Here, we show how the long-standing search for a high temperature narrowband near-field emitter for thermophotovoltaics can be fulfilled by thermally exciting plasmons. We also describe a method to control Wein's displacement law in the near-field using high temperature epsilon-near-zero metamaterials. Finally, we show that our work opens up an interesting direction of research for the field of slow light: thermal emission control.

Guo, Yu; Molesky, Sean; Hu, Huan; Cortes, Cristian L.; Jacob, Zubin, E-mail: zjacob@ualberta.ca [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)

2014-08-18T23:59:59.000Z

387

July 18, 2012 Using QECBs for Street Lighting Upgrades  

E-Print Network [OSTI]

lighting technologies (e.g. light-emitting diodes, induction lighting) can reduce street light energy

388

Efficiency Maine Residential Lighting Program  

Broader source: Energy.gov [DOE]

Efficiency Maine's Residential Lighting Program works directly with retailers and manufacturers to encourage residential customers to purchase energy-efficient lighting. Rebate amounts average $1...

389

Defect correlated fluorescent quenching and electron phonon coupling in the spectral transition of Eu{sup 3+} in CaTiO{sub 3} for red emission in display application  

SciTech Connect (OSTI)

This paper reports on the defect correlated self-quenching and spectroscopic investigation of calcium titanate (CaTiO{sub 3}) phosphors. A series of CaTiO{sub 3} phosphors doped with trivalent europium (Eu{sup 3+}) and codoped with potassium (K{sup +}) ions were prepared by the solid state reaction method. The X-ray diffraction results revealed that the obtained powder phosphors consisted out of a single-phase orthorhombic structure and it also indicated that the incorporation of the dopants/co-dopants did not affect the crystal structure. The scanning electron microscopy images revealed the irregular morphology of the prepared phosphors consisting out of ?m sized diameter particles. The Eu{sup 3+} doped phosphors illuminated with ultraviolet light showed the characteristic red luminescence corresponding to the {sup 5}D{sub 0}?{sup 7}F{sub J} transitions of Eu{sup 3+}. As a charge compensator, K{sup +} ions were incorporated into the CaTiO{sub 3}:Eu{sup 3+} phosphors, which enhanced the photoluminescence (PL) intensities depending on the doping concentration of K{sup +}. The concentration quenching of Eu{sup 3+} in this host is discussed in the light of ion-ion interaction, electron phonon coupling, and defect to ion energy transfer. The spectral characteristics and the Eu-O ligand behaviour were determined using the Judd-Ofelt theory from the PL spectra instead of the absorption spectra. The CIE (International Commission on Illumination) parameters were calculated using spectral energy distribution functions and McCamy's empirical formula. Photometric characterization indicated the suitability of K{sup +} compensated the CaTiO{sub 3}:Eu{sup 3+} phosphor for pure red emission in light-emitting diode applications.

Som, S., E-mail: sudipta.som@gmail.com, E-mail: swarthc@ufs.ac.za; Kumar, Vinod; Kumar, Vijay; Terblans, J. J.; Swart, H. C., E-mail: sudipta.som@gmail.com, E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, Box 339, Bloemfontein 9300 (South Africa); Kunti, A. K.; Dutta, S.; Chowdhury, M.; Sharma, S. K. [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India)

2014-05-21T23:59:59.000Z

390

Thermally Polymerized Rylene Nanoparticles  

E-Print Network [OSTI]

Rylene dyes functionalized with varying numbers of phenyl trifluorovinyl ether (TFVE) moieties were subjected to a thermal emulsion polymerization to yield shape-persistent, water-soluble chromophore nanoparticles. Perylene ...

Andrew, Trisha Lionel

391

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...

Stanley, T. F.

1982-01-01T23:59:59.000Z

392

Thermally driven circulation  

E-Print Network [OSTI]

Several problems connected by the theme of thermal forcing are addressed herein. The main topic is the stratification and flow field resulting from imposing a specified heat flux on a fluid that is otherwise confined to a ...

Nelken, Haim

1987-01-01T23:59:59.000Z

393

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

394

Method and apparatus for thermal management of vehicle exhaust systems  

DOE Patents [OSTI]

A catalytic converter is surrounded by variable conductance insulation for maintaining the operating temperature of the catalytic converter at an optimum level, for inhibiting heat loss when raising catalytic converter temperature to light-off temperature, for storing excess heat to maintain or accelerate reaching light-off temperature, and for conducting excess heat away from the catalytic converter after reaching light-off temperature. The variable conductance insulation includes vacuum gas control and metal-to-metal thermal shunt mechanisms. Radial and axial shielding inhibits radiation and convection heat loss. Thermal storage media includes phase change material, and heat exchanger chambers and fluids carry heat to and from the catalytic converter. 7 figs.

Benson, D.K.; Potter, T.F.

1995-12-26T23:59:59.000Z

395

Thermal dilepton rates from quenched lattice QCD  

E-Print Network [OSTI]

We present new lattice results on the continuum extrapolation of the vector current correlation function. Lattice calculations have been carried out in the deconfined phase at a temperature of 1.1 Tc, extending our previous results at 1.45 Tc, utilizing quenched non-perturbatively clover-improved Wilson fermions and light quark masses. A systematic analysis on multiple lattice spacings allows to perform the continuum limit of the correlation function and to extract spectral properties in the continuum limit. Our current analysis suggests the results for the electrical conductivity are proportional to the temperature and the thermal dilepton rates in the quark gluon plasma are comparable for both temperatures. Preliminary results of the continuum extrapolated correlation function at finite momenta, which relates to thermal photon rates, are also presented.

H. -T. Ding; A. Francis; O. Kaczmarek; F. Karsch; E. Laermann; S. Mukherjee; M. Müller; W. Soeldner

2013-01-30T23:59:59.000Z

396

Dynamic modelling for thermal micro-actuators using thermal networks  

E-Print Network [OSTI]

Dynamic modelling for thermal micro-actuators using thermal networks Beatriz L´opez-Wallea,1 and analytical calculations. Key words: Micro-actuators, Thermal modelling, Electrical analogy, Thermal network 1 and MicroMechatronic Systems Department (AS2M), 24 rue Alain Savary, 25000 Besan¸con, France Abstract

Paris-Sud XI, Université de

397

Lighting affects appearance LightSource emits photons  

E-Print Network [OSTI]

1 Lighting affects appearance #12;2 LightSource emits photons Photons travel in a straight line). And then some reach the eye/camera. #12;3 Basic fact: Light is linear Double intensity of sources, double photons reaching eye. Turn on two lights, and photons reaching eye are same as sum of number when each

Jacobs, David

398

ECE 466: LED Lighting Systems -Incandescent lightings rise and  

E-Print Network [OSTI]

versus cost - Power Electronic Drives for CFL and LED light sources to achieve dimmable operation - Basic electric AC and DC circuits at Sophomore level or equivalents Absolutes Lighting System Requirements index as a metric of a light source - Power Electronic Energy sources driving light sources in a compact

Schumacher, Russ

399

Lighting and Surfaces 11.1 Introduction to Lighting  

E-Print Network [OSTI]

-object-at-a-time. "Intrinsic" light is the light emitted by the object itself, such as the glow from a TV screen, a light-emitting diode, or a star. "Ambient" light is an illumination that seems to come from all sides. In the real

Boyd, John P.

400

Explaining the observed long coherence effects by 2D photon echo experiments in photosynthetic EET : Two-Component Phonon Spectrum model  

E-Print Network [OSTI]

We propose a simple stochastic model which successfully explains the long coherence effects observed in photosynthetic Excitation Energy Transport (EET) by 2D photon echo experiments of G. S. Engel et. al. (Nature, {\\bf 446} 782, (2007)). Our Two-Component Phonon Spectrum (TCPS) model is based upon the division of phonon degrees of freedom into a systematic component which is treated through polaron transformation and a stochastic component which is treated through dynamical disorder. This model successfully explains the observed long coherence upto $ \\sim 600 fsec$ in EET experiments.

Singh, Navinder; Amritkar, R E

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Explaining the observed long coherence effects by 2D photon echo experiments in photosynthetic EET : Two-Component Phonon Spectrum model  

E-Print Network [OSTI]

We propose a simple stochastic model which successfully explains the long coherence effects observed in photosynthetic Excitation Energy Transport (EET) by 2D photon echo experiments of G. S. Engel et. al. (Nature, {\\bf 446} 782, (2007)). Our Two-Component Phonon Spectrum (TCPS) model is based upon the division of phonon degrees of freedom into a systematic component which is treated through polaron transformation and a stochastic component which is treated through dynamical disorder. This model successfully explains the observed long coherence upto $ \\sim 600 fsec$ in EET experiments.

Navinder Singh; V. M. Kenkre; R. E. Amritkar

2011-12-16T23:59:59.000Z

402

Sandia National Laboratories: White Light Creation Architectures  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

TechnologiesWhite Light Creation Architectures White Light Creation Architectures Overview of SSL White Light Creation Architectures The entire spectral range of visible light can...

403

Pupillary efficient lighting system  

DOE Patents [OSTI]

A lighting system having at least two independent lighting subsystems each with a different ratio of scotopic illumination to photopic illumination. The radiant energy in the visible region of the spectrum of the lighting subsystems can be adjusted relative to each other so that the total scotopic illumination of the combined system and the total photopic illumination of the combined system can be varied independently. The dilation or contraction of the pupil of an eye is controlled by the level of scotopic illumination and because the scotopic and photopic illumination can be separately controlled, the system allows the pupil size to be varied independently of the level of photopic illumination. Hence, the vision process can be improved for a given level of photopic illumination.

Berman, Samuel M. (San Francisco, CA); Jewett, Don L. (Mill Valley, CA)

1991-01-01T23:59:59.000Z

404

Light harvesting arrays  

DOE Patents [OSTI]

A light harvesting array useful for the manufacture of devices such as solar cells comprises: (a) a first substrate comprising a first electrode; and (b) a layer of light harvesting rods electrically coupled to the first electrode, each of the light harvesting rods comprising a polymer of Formula I: X.sup.1.paren open-st.X.sup.m+1).sub.m (I) wherein m is at least 1, and may be from two, three or four to 20 or more; X.sup.1 is a charge separation group (and preferably a porphyrinic macrocycle, which may be one ligand of a double-decker sandwich compound) having an excited-state of energy equal to or lower than that of X.sup.2, and X.sup.2 through X.sup.m+1 are chromophores (and again are preferably porphyrinic macrocycles).

Lindsey, Jonathan S. (Raleigh, NC)

2002-01-01T23:59:59.000Z

405

Light emitting ceramic device  

DOE Patents [OSTI]

A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, is herein claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.

Valentine, Paul; Edwards, Doreen D.; Walker, Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard

2010-05-18T23:59:59.000Z

406

Radioluminescent lighting technology  

SciTech Connect (OSTI)

The glow-in-the-dark stereotype that characterizes the popular image of nuclear materials is not accidental. When the French scientist, Henri Becquerel, first discovered radioactivity in 1896, he was interested in luminescence. Radioluminescence, the production of light from a mixture of energetic and passive materials, is probably the oldest practical application of the unstable nucleus. Tritium-based radioluminescent lighting, in spite of the biologically favorable character of the gaseous tritium isotope, was included in the general tightening of environmental and safety regulations. Tritium light manufacturers would have to meet two fundamental conditions: (1) The benefit clearly outweighed the risk, to the extent that even the perceived risk of a skeptical public would be overcome. (2) The need was significant enough that the customer/user would be willing and able to afford the cost of regulation that was imposed both in the manufacture, use and eventual disposal of nuclear materials. In 1981, researchers at Oak Ridge National Laboratory were investigating larger radioluminescent applications using byproduct nuclear material such as krypton-85, as well as tritium. By 1982, it appeared that large source, (100 Curies or more) tritium gas tube, lights might be useful for marking runways and drop zones for military operations and perhaps even special civilian aviation applications. The successful development of this idea depended on making the light bright enough and demonstrating that large gas tube sources could be used and maintained safely in the environment. This successful DOE program is now in the process of being completed and closed-out. Working closely with the tritium light industry, State governments and other Federal agencies, the basic program goals have been achieved. This is a detailed report of what they have learned, proven, and discovered. 91 refs., 29 figs., 5 tabs. (JF)

Not Available

1990-01-01T23:59:59.000Z

407

1D-to-3D transition of phonon heat conduction in polyethylene using molecular dynamics simulations  

E-Print Network [OSTI]

The thermal conductivity of nanostructures generally decreases with decreasing size because of classical size effects. The axial thermal conductivity of polymer chain lattices, however, can exhibit the opposite trend, ...

Henry, Asegun

408

MANDATORY MEASURES INDOOR LIGHTING CONTROLS  

E-Print Network [OSTI]

MANDATORY MEASURES INDOOR LIGHTING CONTROLS (Reference: Sub-Chapter 4, Section 130.1) #12;SECTION 4 MANDATORY LIGHTING CONTROLS 1. 130.1 (a) Area Controls: Manual controls that control lighting in each area separately 2. 130.1 (b) Multi-level Controls: Allow occupants to choose the appropriate light level for each

California at Davis, University of

409

MANDATORY MEASURES INDOOR LIGHTING CONTROLS  

E-Print Network [OSTI]

MANDATORY MEASURES INDOOR LIGHTING CONTROLS (Reference: Sub-Chapter 4, Section 130.1) #12;SECTION 3 MANDATORY LIGHTING CONTROLS 1. 130.1 (a) Area Controls: Manual controls that control lighting in each area separately 2. 130.1 (b) Multi-level Controls: "Dimmability." Allow occupants to choose the appropriate light

California at Davis, University of

410

LIGHTING 101 1. Common terminology  

E-Print Network [OSTI]

SECTION 3 LIGHTING 101 1. Common terminology 2. Sources & luminaires 3. Controls #12;SECTION 3SECTION 3 DISCUSSION: COMMON LIGHTING TERMINOLOGY 1. What are the definitions of the following lighting terms? 2. Do you use these terms in professional practice? 3. What other lighting terminology do you use

California at Davis, University of

411

MANDATORY MEASURES INDOOR LIGHTING CONTROLS  

E-Print Network [OSTI]

MANDATORY MEASURES INDOOR LIGHTING CONTROLS (Reference: Sub-Chapter 4, Section 130.1) #12;SECTION 5 MANDATORY LIGHTING CONTROLS 1. Area Controls: Manual controls that control lighting in each area separately 2. Multi-level Controls: Allow occupants to choose the appropriate light level for each area 3. Shut

California at Davis, University of

412

LIGHTING 101 1. Common terminology  

E-Print Network [OSTI]

LIGHTING 101 1. Common terminology 2. Sources and luminaires 3. Controls #12;SECTION 2 DISCUSSION: COMMON LIGHTING TERMINOLOGY 1. What are the definitions of the following lighting terms? 2. Do you use these terms in professional practice? 3. What other lighting terminology do you use on the job? SLIDE 14

California at Davis, University of

413

Extreme Ultraviolet Light Chris Cosio  

E-Print Network [OSTI]

Prospectus Extreme Ultraviolet Light Chris Cosio #12;The field of extreme ultraviolet light (XUV to the way XUV interacts with object, XUV properties are difficult to observe. Extreme ultraviolet light is absorbed by all objects it comes in contact with. Furthermore, extreme ultraviolet light also has low

Hart, Gus

414

Oxycarbonitride phosphors and light emitting devices using the same  

DOE Patents [OSTI]

Disclosed herein is a novel family of oxycarbidonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbidonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

2013-10-08T23:59:59.000Z

415

Oxycarbonitride phosphors and light emitting devices using the same  

DOE Patents [OSTI]

Disclosed herein is a novel family of oxycarbonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

2014-07-08T23:59:59.000Z

416

Flip-chip light emitting diode with resonant optical microcavity  

SciTech Connect (OSTI)

A flip-chip light emitting diode with enhanced efficiency. The device structure employs a microcavity structure in a flip-chip configuration. The microcavity enhances the light emission in vertical modes, which are readily extracted from the device. Most of the rest of the light is emitted into waveguided lateral modes. Flip-chip configuration is advantageous for light emitting diodes (LEDs) grown on dielectric substrates (e.g., gallium nitride LEDs grown on sapphire substrates) in general due to better thermal dissipation and lower series resistance. Flip-chip configuration is advantageous for microcavity LEDs in particular because (a) one of the reflectors is a high-reflectivity metal ohmic contact that is already part of the flip-chip configuration, and (b) current conduction is only required through a single distributed Bragg reflector. Some of the waveguided lateral modes can also be extracted with angled sidewalls used for the interdigitated contacts in the flip-chip configuration.

Gee, James M.; Bogart, Katherine H.; Fischer, Arthur J.

2005-11-29T23:59:59.000Z

417

Recent applications of thermal imagers for security assessment  

SciTech Connect (OSTI)

This paper discusses recent applications by Sandia National Laboratories of cooled and uncooled thermal infrared imagers to wide-area security assessment systems. Thermal imagers can solve many security assessment problems associated with the protection of high-value assets at military bases, secure installations, and commercial facilities. Thermal imagers can provide surveillance video from security areas or perimeters both day and night without expensive security lighting. Until fairly recently, thermal imagers required open-loop cryogenic cooling to operate. The high cost of these systems and associated maintenance requirements restricted their widespread use. However, recent developments in reliable, closed-loop, linear drive cryogenic coolers and uncooled infrared imagers have dramatically reduced maintenance requirements, extended MTBF, and are leading to reduced system cost. These technology developments are resulting in greater availability and practicality for military as well as civilian security applications.

Bisbee, T.L.

1997-06-01T23:59:59.000Z

418

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

419

Simultaneous sensing of light and sound velocities of fluids in a two-dimensional phoXonic crystal with defects  

SciTech Connect (OSTI)

We theoretically investigate the potentiality of dual phononic-photonic (the so-called phoxonic) crystals for liquid sensing applications. We study the transmission through a two-dimensional (2D) crystal made of infinite cylindrical holes in a silicon substrate, where one row of holes oriented perpendicular to the propagation direction is filled with a liquid. The infiltrated holes may have a different radius than the regular holes. We show, in the defect structure, the existence of well-defined features (peaks or dips) in the transmission spectra of acoustic and optical waves and estimate their sensitivity to the sound and light velocity of the analyte. Some of the geometrical requirements behave in opposite directions when searching for an efficient sensing of either sound or light velocities. Hence, a compromise in the choice of the parameters may become necessary in making the phoxonic sensor.

Amoudache, Samira [Institut d'Electronique, de Microélectronique et de Nanotechnologie, Université de Lille 1, 59655 Villeneuve d'Ascq (France); Laboratoire de Physique et Chimie Quantique, Université Mouloud Mammeri, B.P. 17 RP, 15000 Tizi-Ouzou (Algeria); Pennec, Yan, E-mail: yan.pennec@univ-lille1.fr; Djafari Rouhani, Bahram [Institut d'Electronique, de Microélectronique et de Nanotechnologie, Université de Lille 1, 59655 Villeneuve d'Ascq (France); Khater, Antoine [Institut des Molécules et Matériaux du Mans UMR 6283 CNRS, Université du Maine, 72085 Le Mans (France); Lucklum, Ralf [Institute of Micro and Sensor Systems (IMOS), Otto-von-Guericke-University, Magdeburg (Germany); Tigrine, Rachid [Laboratoire de Physique et Chimie Quantique, Université Mouloud Mammeri, B.P. 17 RP, 15000 Tizi-Ouzou (Algeria)

2014-04-07T23:59:59.000Z

420

Windows and lighting program  

SciTech Connect (OSTI)

More than 30% of all energy use in buildings is attributable to two sources: windows and lighting. Together they account for annual consumer energy expenditures of more than $50 billion. Each affects not only energy use by other major building systems, but also comfort and productivity -- factors that influence building economics far more than does direct energy consumption alone. Windows play a unique role in the building envelope, physically separating the conditioned space from the world outside without sacrificing vital visual contact. Throughout the indoor environment, lighting systems facilitate a variety of tasks associated with a wide range of visual requirements while defining the luminous qualities of the indoor environment. Windows and lighting are thus essential components of any comprehensive building science program. Despite important achievements in reducing building energy consumption over the past decade, significant additional savings are still possible. These will come from two complementary strategies: (1) improve building designs so that they effectively apply existing technologies and extend the market penetration of these technologies; and (2) develop advanced technologies that increase the savings potential of each application. Both the Windows and Daylighting Group and the Lighting System Research Group have made substantial contributions in each of these areas, and continue to do so through the ongoing research summarized here. 23 refs., 16 figs.

Not Available

1990-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Radioluminescent polymer lights  

SciTech Connect (OSTI)

The preparation of radioluminescent light sources where the tritium is located on the aryl-ring in a polymer has been demonstrated with deuterium/tritium substitution. This report discusses tests, results, and future applications of radioluminescent polymers. 10 refs. (FI)

Jensen, G.A.; Nelson, D.A.; Molton, P.M.

1990-09-01T23:59:59.000Z

422

Sweetness and light   

E-Print Network [OSTI]

1. Sweetness and Light. A novel. Judi lives in a nice, clean house with her seventeen year old stepson, who won’t talk to her in anything but monosyllables. His father, Nelson, and she are struggling to relate to each ...

Craig, Katie

2014-07-03T23:59:59.000Z

423

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect (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

424

Thermal insulated glazing unit  

SciTech Connect (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.

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

1991-01-01T23:59:59.000Z

425

Thermal insulated glazing unit  

SciTech Connect (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

426

Thermal test options  

SciTech Connect (OSTI)

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

427

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

428

Scattering Solar Thermal Concentrators  

Broader source: Energy.gov [DOE]

"This fact sheet describes a scattering solar thermal concentrators project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Pennsylvania State University, is working to demonstrate a new, scattering-based approach to concentrating sunlight that aims to improve the overall performance and reliability of the collector field. The research team aims to show that scattering solar thermal collectors are capable of achieving optical performance equal to state-of-the-art parabolic trough systems, but with the added benefits of immunity to wind-load tracking error, more efficient land use, and utilization of stationary receivers."

429

Strong electron-phonon coupling of the high-energy modes of carbon nanotubes M. Machn,1 S. Reich,2 and C. Thomsen1  

E-Print Network [OSTI]

Strong electron-phonon coupling of the high-energy modes of carbon nanotubes M. Machón,1 S. Reich,2 of the totally symmetric high-energy vibrational modes of carbon nanotubes. The matrix elements depend, for achiral nanotubes, only one of the graphite-derived high-energy modes is totally symmetric, the other

Nabben, Reinhard

430

Journal of Applied Physics --March 1, 2001 --Volume 89, Issue 5, pp. 2932-2938 Phonon heat conduction in a semiconductor nanowire  

E-Print Network [OSTI]

in the nonequilibrium phonon distribution due to partially diffuse boundary scattering. Numerical simulation. The value of this decrease and its interface roughness and temperature dependence are different from. Quantum Electron. 6, 511 (2000). [INSPEC] 7.X. Sun, Z. Zhang, and M. S. Dresselhaus, Appl. Phys. Lett. 74

431

Electron-electron and electron-phonon interactions in irradiated N-methyl pyridinium derivatives with TCNQ studied by optical spectroscopy  

E-Print Network [OSTI]

1417 Electron-electron and electron-phonon interactions in irradiated N-methyl pyridinium derivatives with TCNQ studied by optical spectroscopy A. Graja and R. Swietlik Institute of Molecular Physics le 13 mars 1985, accepti le ler avril 1985) Résumé. 2014 L'irradiation électronique des

Boyer, Edmond

432

Light Activated Self-Propelled Colloids  

E-Print Network [OSTI]

Light-activated self-propelled colloids are synthesized and their active motion is studied using optical microscopy. We propose a versatile route using different photoactive materials, and demonstrate a multiwavelength activation and propulsion. Thanks to the photoelectrochemical properties of two semiconductor materials (\\alpha Fe2 O3 and TiO2 ), a light with an energy higher than the bandgap triggers the reaction of decomposition of hydrogen peroxide and produces a chemical cloud around the particle. It induces a phoretic attraction with neighbouring colloids as well as an osmotic self- propulsion of the particle on the substrate. We use these mechanisms to form colloidal cargos as well as self-propelled particles where the light-activated component is embedded into a dielectric sphere. The particles are self-propelled along a direction otherwise randomized by thermal fluctuations, and exhibit a persistent random walk. For sufficient surface density, the particles spontaneously form "living crystals" which are mobile, break apart and reform. Steering the particle with an external magnetic field, we show that the formation of the dense phase results from the collisions heads-on of the particles. This effect is intrinsically non-equilibrium and a novel principle of organization for systems without detailed balance. Engineering families of particles self-propelled by different wavelength demonstrate a good understanding of both the physics and the chemistry behind the system and points to a general route for designing new families of self-propelled particles.

J. Palacci; S. Sacanna; S. -H. Kim; G. -R. Yi; D. J. Pine; P. M. Chaikin

2014-10-27T23:59:59.000Z

433

Full light absorption in single arrays of spherical nanoparticles  

E-Print Network [OSTI]

In this paper we show that arrays of core-shell nanoparticles function as effective thin absorbers of light. In contrast to known metamaterial absorbers, the introduced absorbers are formed by single planar arrays of spherical inclusions and enable full absorption of light incident on either or both sides of the array. We demonstrate possibilities for realizing different kinds of symmetric absorbers, including resonant, ultra-broadband, angularly selective, and all-angle absorbers. The physical principle behind these designs is explained considering balanced electric and magnetic responses of unit cells. Photovoltaic devices and thermal emitters are the two most important potential applications of the proposed designs.

Ra'di, Y; Kosulnikov, S U; Omelyanovich, M M; Morits, D; Osipov, A V; Simovski, C R; Tretyakov, S A

2015-01-01T23:59:59.000Z

434

Systems analysis of thermal storage  

SciTech Connect (OSTI)

During FY 1981, analyses were conducted on thermal storage concepts for solar thermal applications. These studies include estimates of both the obtainable costs of thermal storage concepts and their worth to a user (i.e., value). Based on obtainable costs and performance, an in-depth study evaluated thermal storage concepts for water/steam, organic fluid, and gas/Brayton solar thermal receivers. Promising and nonpromising concepts were identified. A study to evaluate thermal storage concepts for a liquid metal receiver was initiated. The value of thermal storage in a solar thermal industrial process heat application was analyzed. Several advanced concepts are being studied, including ground-mounted thermal storage for parabolic dishes with Stirling engines.

Copeland, R.J.

1981-08-01T23:59:59.000Z

435

Medical catheters thermally manipulated by fiber optic bundles  

DOE Patents [OSTI]

A maneuverable medical catheter comprising a flexible tube having a functional tip. The catheter is connected to a control source. The functional tip of the catheter carries a plurality of temperature activated elements arranged in parallel and disposed about the functional tip and held in spaced relation at each end. These elements expand when they are heated. A plurality of fiber optic bundles, each bundle having a proximal end attached to the control source and a distal end attached to one of the elements carry light into the elements where the light is absorbed as heat. By varying the optic fiber that is carrying the light and the intensity of the light, the bending of the elements can be controlled and thus the catheter steered. In an alternate embodiment, the catheter carries a medical instrument for gathering a sample of tissue. The instrument may also be deployed and operated by thermal expansion and contraction of its moving parts.

Chastagner, Philippe (608 Aumond Rd., Augusta, GA 30909)

1992-01-01T23:59:59.000Z

436

Investigation of bit patterned media, thermal flying height control sliders and heat assisted magnetic recording in hard disk drives  

E-Print Network [OSTI]

Talke, “The effect of UV stabilizer on photo degradation ofUV-Stabilizer terminal groups ([162]). Thermal degradationUV light interact with the lubricant molecules and generate hydrogen radicals that accelerate the degradation

Zheng, Hao

2011-01-01T23:59:59.000Z

437

Thermal Reactor Safety  

SciTech Connect (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

438

Thermal management of nanoelectronics  

E-Print Network [OSTI]

-state thermoelectric on- spot cooling, requiring efficient thermoelectric materials that can be integrated with the IC are further complicated by the fact that the material's ability to conduct heat deteriorates when at the packaging level but also at the nanoscale materials and device levels. THERMAL CHALLENGES AT NANOSCALE One

439

Thermal Infrared Remote Sensing  

E-Print Network [OSTI]

to us, like reflective ("nearreflective ("near--" infrared (0.7" infrared (0.7 -- 3.03.0 µµm)m) andand near-infrared far infrared ultraviolet Thermal Infrared refers to region o EM spectrum from ~3 - 14 µm.landscape. IMPORTANT: NEARIMPORTANT: NEAR--INFRARED is short enough wavelength toINFRARED is short enough wavelength

440

Low thermal conductivity skutterudites  

SciTech Connect (OSTI)

Recent experimental results on semiconductors with the skutterudite crystal structure show that these materials possess attractive transport properties and have a good potential for achieving ZT values substantially larger than for state-of-the-art thermoelectric materials. Both n-type and p-type conductivity samples have been obtained, using several preparation techniques. Associated with a low hole effective mass, very high carrier mobilities, low electrical resistivities and moderate Seebeck coefficients are obtained in p-type skutterudites. For a comparable doping level, the carrier mobilities of n-type samples are about an order of magnitude lower than the values achieved on p-type samples. However, the much larger electron effective masses and Seebeck coefficients on p-type samples. However, the much larger electron effective masses and Seebeck coefficients make n-type skutterudite promising candidates as well. Unfortunately, the thermal conductivities of the binary skutterudites compounds are too large, particularly at low temperatures, to be useful for thermoelectric applications. Several approaches to the reduction of the lattice thermal conductivity in skutterudites are being pursued: heavy doping, formation of solid solutions and alloys, study of novel ternary and filled skutterudite compounds. All those approaches have already resulted in skutterudite compositions with substantially lower thermal conductivity values in these materials. Recently, superior thermoelectric properties in the moderate to high temperature range were achieved for compositions combining alloying and filling of the skutterudite structure. Experimental results and mechanisms responsible for low thermal conductivity in skutterudites are discussed.

Fleurial, J.P.; Caillat, T.; Borshchevsky, A.

1997-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "lighting phonons thermal" 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

Thermal barrier coating  

DOE Patents [OSTI]

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

442

Nonequilibrium lighting plasmas  

SciTech Connect (OSTI)

In this paper the science of a variety of devices employing nonequilibrium lighting plasmas is reviewed. The devices include the fluorescent lamp, the low-pressure sodium lamp, the neon sign, ultraviolet lamps, glow indicators, and a variety of devices used by spectroscopists, such as the hollow cathode light source. The plasma conditions in representative commercial devices are described. Recent research on the electron gas, the role of heavy particles, spatial and temporal inhomogeneities, and new electrodeless excitation schemes is reviewed. Areas of future activity are expected to be in new applications of high-frequency electronics to commercial devices, new laser-based diagnostics of plasma conditions, and more sophisticated models requiring more reliable and extensive rate coefficient data.

Dakin, J.T. (GE Lighting, Nela Park, Cleveland, OH (US))

1991-12-01T23:59:59.000Z

443

Light cone matrix product  

SciTech Connect (OSTI)

We show how to combine the light-cone and matrix product algorithms to simulate quantum systems far from equilibrium for long times. For the case of the XXZ spin chain at {Delta} = 0.5, we simulate to a time of {approx} 22.5. While part of the long simulation time is due to the use of the light-cone method, we also describe a modification of the infinite time-evolving bond decimation algorithm with improved numerical stability, and we describe how to incorporate symmetry into this algorithm. While statistical sampling error means that we are not yet able to make a definite statement, the behavior of the simulation at long times indicates the appearance of either 'revivals' in the order parameter as predicted by Hastings and Levitov (e-print arXiv:0806.4283) or of a distinct shoulder in the decay of the order parameter.

Hastings, Matthew B [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

444

OLEDS FOR GENERAL LIGHTING  

SciTech Connect (OSTI)

The goal of this program was to reduce the long term technical risks that were keeping the lighting industry from embracing and developing organic light-emitting diode (OLED) technology for general illumination. The specific goal was to develop OLEDs for lighting to the point where it was possible to demonstrate a large area white light panel with brightness and light quality comparable to a fluorescence source and with an efficacy comparable to that of an incandescent source. it was recognized that achieving this would require significant advances in three area: (1) the improvement of white light quality for illumination, (2) the improvement of OLED energy efficiency at high brightness, and (3) the development of cost-effective large area fabrication techniques. The program was organized such that, each year, a ''deliverable'' device would be fabricated which demonstrated progress in one or more of the three critical research areas. In the first year (2001), effort concentrated on developing an OLED capable of generating high illumination-quality white light. Ultimately, a down-conversion method where a blue OLED was coupled with various down-conversion layers was chosen. Various color and scattering models were developed to aid in material development and device optimization. The first year utilized this approach to deliver a 1 inch x 1 inch OLED with higher illumination-quality than available fluorescent sources. A picture of this device is shown and performance metrics are listed. To their knowledge, this was the first demonstration of true illumination-quality light from an OLED. During the second year, effort concentrated on developing a scalable approach to large area devices. A novel device architecture consisting of dividing the device area into smaller elements that are monolithically connected in series was developed. In the course of this development, it was realized that, in addition to being scalable, this approach made the device tolerant to the most common OLED defect--electrical shorts. This architecture enabled the fabrication of a 6 inch x 6 inch OLED deliverable for 2002. A picture of this deliverable is shown and the performance metrics are listed. At the time, this was the highest efficiency, highest lumen output illumination-quality OLED in existence. The third year effort concentrated on improving the fabrication yield of the 6 inch x 6 inch devices and improving the underlying blue device efficiency. An efficiency breakthrough was achieved through the invention of a new device structure such that now 15 lumen per watt devices could be fabricated. A 2 feet x 2 feet OLED panel consisting of sixteen 6 inch x 6 inch high efficiency devices tiled together was then fabricated. Pictures of this panel are shown with performance metrics listed. This panel met all project objectives and was the final deliverable for the project. It is now the highest efficiency, highest lumen output, illumination-quality OLED in existence.

Anil Duggal; Don Foust; Chris Heller; Bill Nealon; Larry Turner; Joe Shiang; Nick Baynes; Tim Butler; Nalin Patel

2004-02-29T23:59:59.000Z

445

Fusion pumped light source  

DOE Patents [OSTI]

Apparatus is provided for generating energy in the form of light radiation. A fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The neutron flux is coupled directly with the lasing medium. The lasing medium includes a first component selected from Group O of the periodic table of the elements and having a high inelastic scattering cross section. Gamma radiation from the inelastic scattering reactions interacts with the first component to excite the first component, which decays by photon emission at a first output wavelength. The first output wavelength may be shifted to a second output wavelength using a second liquid component responsive to the first output wavelength. The light outputs may be converted to a coherent laser output by incorporating conventional optics adjacent the laser medium.

Pappas, Daniel S. (Los Alamos, NM)

1989-01-01T23:59:59.000Z

446

High-Temperature Thermal Array for Next Generation Solar Thermal...  

Broader source: Energy.gov (indexed) [DOE]

3 Q1 High-Temperature Thermal Array for Next Generation Solar Thermal Power Production - FY13 Q1 This document summarizes the progress of this Los Alamos National Laboratory...

447

Suppression of infrared instability in trans-sonic flows by condensation of zero-frequency short wave length phonons  

E-Print Network [OSTI]

We analyze the peculiar infrared instability that characterizes stationary inhomogeneous flows when their velocity crosses the sound speed by decreasing values. For definiteness, we work in the context of one dimensional atomic Bose condensates. These flows are unstable under ultra low real frequency perturbations because of the unbounded mode amplification near the sonic horizon. This results in a condensation of low frequency phonons which produces a spatially structured flow in the supersonic domain. Numerical simulations reveal that this zero-frequency undulation suppresses the instability when its spatial extension is infinite, and when its phase is near that of a "shadow soliton" solution attached to the sonic horizon. These phenomena are akin to the condensation of rotons in flowing superfluid helium-4 when exceeding the Landau velocity. They also pertain to shallow water waves propagating on transcritical flows.

Xavier Busch; Florent Michel; Renaud Parentani

2014-11-28T23:59:59.000Z

448

Suppression of infrared instability in trans-sonic flows by condensation of zero-frequency short wave length phonons  

E-Print Network [OSTI]

We analyze the peculiar infrared instability that characterizes stationary inhomogeneous flows when their velocity crosses the sound speed by decreasing values. For definiteness, we work in the context of one dimensional atomic Bose condensates. These flows are unstable under ultra low real frequency perturbations because of the unbounded mode amplification near the sonic horizon. This results in a condensation of low frequency phonons which produces a spatially structured flow in the supersonic domain. Numerical simulations reveal that this zero-frequency undulation suppresses the instability when its spatial extension is infinite, and when its phase is near that of a "shadow soliton" solution attached to the sonic horizon. These phenomena are akin to the condensation of rotons in flowing superfluid helium-4 when exceeding the Landau velocity. They also pertain to shallow water waves propagating on transcritical flows.

Xavier Busch; Florent Michel; Renaud Parentani

2015-02-06T23:59:59.000Z

449

The Tunable Hybrid Surface Phonon and Plasmon Polariton Modes in Boron Nitride Nanotube and Graphene Monolayer Heterostructures  

E-Print Network [OSTI]

The hybrid modes incorporating surface phonon polariton (SPhP) modes in boron nitride nanotubes (BNNTs) and surface plasmon polariton (SPP) modes in graphene monolayers are theoretically studied. The combination of the 1D BNNTs and 2D graphene monolayer further improves the modal characteristics with electrical tunability. Superior to the graphene monolayers, the proposed heterostructures supports single mode transmission with lateral optical confinement. The modal characteristics can be shifted from SPP-like toward SPhP-like. Both the figure of merit and field enhancement of hybrid modes are improved over 3 times than those of BNNT SPhP modes, which may further enable sub-wavelength mid-infrared applications.

Sun, Yu; Cheng, Jiangtao; Liu, Jiansheng

2014-01-01T23:59:59.000Z

450

Preliminary requirements for thermal storage subsystems in solar thermal applications  

SciTech Connect (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

451

High Energy Density Thermal Batteries: Thermoelectric Reactors for Efficient Automotive Thermal Storage  

SciTech Connect (OSTI)

HEATS Project: Sheetak is developing a new HVAC system to store the energy required for heating and cooling in EVs. This system will replace the traditional refrigerant-based vapor compressors and inefficient heaters used in today’s EVs with efficient, light, and rechargeable hot-and-cold thermal batteries. The high energy density thermal battery—which does not use any hazardous substances—can be recharged by an integrated solid-state thermoelectric energy converter while the vehicle is parked and its electrical battery is being charged. Sheetak’s converters can also run on the electric battery if needed and provide the required cooling and heating to the passengers—eliminating the space constraint and reducing the weight of EVs that use more traditional compressors and heaters.

None

2011-11-15T23:59:59.000Z

452

The NGST and the zodiacal light in the Solar system  

E-Print Network [OSTI]

We develop a physical model of the zodiacal cloud incorporating the real dust sources of asteroidal, cometary, and kuiperoidal origin. Using the inferred distribution of the zodiacal dust, we compute its thermal emission and scattering at several wavelengths (1.25, 5, and 20 $\\mu$m) as a function of NGST location assumed to be at 1 AU or 3 AU. Areas on the sky with a minimum of zodiacal light are determined.

Nick Gorkavyi; Leonid Ozernoy; John Mather; Tanya Taidakova

1999-10-29T23:59:59.000Z

453

Turbo-Charged Lighting Design  

E-Print Network [OSTI]

TURBO-CHARGED LIGHTING DESIGN William H. Clark II Design Engineer O'Connell Robertson & Assoc Austin/ Texas ABSTRACT The task of the lighting designer has become very complex, involving thousands of choices for fixture types and hundreds...

Clark, W. H. II

454

138 JOURNAL OF DISPLAY TECHNOLOGY, VOL. 2, NO. 2, JUNE 2006 Improving the Performance of Organic Light-Emitting  

E-Print Network [OSTI]

­LiF­Al is believed to be due to the enhancement of elec- tron injection by thermal treatment. Secondary ion mass spec Light-Emitting Diodes Containing BCP/LiF/Al by Thermal Annealing J. X. Sun, Student Member, IEEE, X. L. However, other devices consisting of Alq3 LiF/Al were less affected. It is believed that the thermal

455

Faster than Light Quantum Communication  

E-Print Network [OSTI]

Faster than light communication might be possible using the collapse of the quantum wave-function without any accompanying paradoxes.

A. Y. Shiekh

2008-04-05T23:59:59.000Z

456

Webinar: Fuel Cell Mobile Lighting  

Broader source: Energy.gov [DOE]

Video recording of the Fuel Cell Technologies Office webinar, Fuel Cell Mobile Lighting, originally presented on November 13, 2012.

457

Photodetector with enhanced light absorption  

DOE Patents [OSTI]

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

Kane, James (Lawrenceville, NJ)

1985-01-01T23:59:59.000Z

458

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

459

THERMAL ENERGY STORAGE IN AQUIFERS WORKSHOP  

E-Print Network [OSTI]

Survey of Thermal Energy Storage in Aquifers Coupled withconcept of thermal energy storage in aquifers was suggestedLow Temperature Thermal Energy Storage Program of Oak Ridge

Authors, Various

2011-01-01T23:59:59.000Z

460

Ocean Thermal Extractable Energy Visualization: Final Technical...  

Office of Environmental Management (EM)

Ocean Thermal Extractable Energy Visualization: Final Technical Report Ocean Thermal Extractable Energy Visualization: Final Technical Report Report about the Ocean Thermal...

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


461

OCEAN THERMAL ENERGY CONVERSION PROGRAMMATIC ENVIRONMENTAL ASSESSMENT  

E-Print Network [OSTI]

M.D. (editor) Ocean Thermal Energy Conversion (OTEC) Draftin Ocean Thermal Energy Conversion (OTEC) technology haveThe Ocean Thermal Energy Conversion (OTEC) 2rogrammatic

Sands, M.Dale

2013-01-01T23:59:59.000Z

462

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

463

First-principles study on negative thermal expansion of PbTiO{sub 3}  

SciTech Connect (OSTI)

It is well known that perovskite-type PbTiO{sub 3} behaves negative thermal expansion in a wide temperature range from room temperature to Curie temperature (763?K). The present study reports the first-principles study of the anisotropic thermal expansion of PbTiO{sub 3}, in the framework of the density-functional theory and the density-functional perturbation theory. The curve of temperature dependence of the unit cell volume is presented from 20 to 520?K through the calculation of the minimum of total free energy at each temperature point. The negative thermal expansion of PbTiO{sub 3} is calculated without empirical parameters. Furthermore, the distinctive thermodynamic act of PbTiO{sub 3} from expanding to contracting at tetragonal phase is reproduced. The ab-initio calculations reveal that this unique appearance depends on the phonon vibration. The dynamical contributions of various atoms are also calculated to account for the disparate role of Pb-O and Ti-O bond.

Wang, Fangfang; Chen, Jun; Xing, Xianran, E-mail: xing@ustb.edu.cn [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)] [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Xie, Ying; Fu, Honggang [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080 (China)] [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080 (China)

2013-11-25T23:59:59.000Z

464

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

465

MANDATORY MEASURES OUTDOOR LIGHTING CONTROLS  

E-Print Network [OSTI]

MANDATORY MEASURES OUTDOOR LIGHTING CONTROLS (Reference: Sub-Chapter 4, Section 130.2) #12;SECTION level of each multi-tier garage. · General lighting must have occupant sensing controls with at least one control step between 20% and 50% of design lighting power · No more than 500 watts of rated

California at Davis, University of

466

MANDATORY MEASURES OUTDOOR LIGHTING CONTROLS  

E-Print Network [OSTI]

MANDATORY MEASURES OUTDOOR LIGHTING CONTROLS (Reference: Sub-Chapter 4, Section 130.2) #12;SECTION 5 Additions and Alterations Any alteration that increases the connected lighting load must meet all No measures required OUTDOOR LIGHTING11/20/2014 #12;SECTION 5 BACKLIGHT, UPLIGHT, AND GLARE (BUG) RATINGS

California at Davis, University of

467

MANDATORY MEASURES OUTDOOR LIGHTING CONTROLS  

E-Print Network [OSTI]

MANDATORY MEASURES OUTDOOR LIGHTING CONTROLS (Reference: Sub-Chapter 4, Section 130.2) #12;SECTION performance in relation to lighting trespass, sky glow, and high angle brightness. This is necessary in order to reduce light pollution, which has a negative effect on wildlife and the surrounding environments

California at Davis, University of

468

Arnold Schwarzenegger, LIGHTING RESEARCH PROGRAM  

E-Print Network [OSTI]

;#12;Prepared By: Lighting Research Center Andrew Bierman, Project Lead Troy, New York 12180 Managed ByArnold Schwarzenegger, Governor LIGHTING RESEARCH PROGRAM PROJECT 3.2 ENERGY EFFICIENT LOAD- SHEDDING LIGHTING TECHNOLOGY Prepared For: California Energy Commission Public Interest Energy Research

469

STATE OF CALIFORNIA RESIDENTIAL LIGHTING  

E-Print Network [OSTI]

STATE OF CALIFORNIA RESIDENTIAL LIGHTING CEC-CF-6R-LTG-01 (Revised 08/09) CALIFORNIA ENERGY COMMISSION INSTALLATION CERTIFICATE CF-6R-LTG-01 Residential Lighting (Page 1 of 6) Site Address: Enforcement Agency: Permit Number: 2008 Residential Compliance Forms August 2009 1. Kitchen Lighting Does project

470

Low Conductivity Thermal Barrier Coatings  

E-Print Network [OSTI]

Low Conductivity Thermal Barrier Coatings A Dissertation Presented to The Faculty of the School conductivity of the coatings. The minimum thermal conductivity occurs at a low rotation rate and is 0.8 W intrinsic thermal conductivity, good phase stability and greater resistance to sintering and CMAS attack

Wadley, Haydn

471

Thermal Stabilization Blend Plan  

SciTech Connect (OSTI)

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

472

Thermal synthesis apparatus  

DOE Patents [OSTI]

An apparatus for thermal conversion of one or more reactants to desired end products includes an insulated reactor chamber having a high temperature heater such as a plasma torch at its inlet end and, optionally, a restrictive convergent-divergent nozzle at its outlet end. In a thermal conversion method, reactants are injected upstream from the reactor chamber and thoroughly mixed with the plasma stream before entering the reactor chamber. The reactor chamber has a reaction zone that is maintained at a substantially uniform temperature. The resulting heated gaseous stream is then rapidly cooled by passage through the nozzle, which "freezes" the desired end product(s) in the heated equilibrium reaction stage, or is discharged through an outlet pipe without the convergent-divergent nozzle. The desired end products are then separated from the gaseous stream.

Fincke, James R. (Idaho Falls, ID) [Idaho Falls, ID; Detering, Brent A. (Idaho Falls, ID) [Idaho Falls, ID

2009-08-18T23:59:59.000Z

473

Advanced method for increasing the efficiency of white light quantum dot LEDs  

SciTech Connect (OSTI)

Covering a light-emitting diode (LED) with quantum dots (QDs) can produce a broad spectrum of white light. However, current techniques for applying QDs to LEDs suffer from a high density of defects and a non-uniform distribution of QDs, which, respectively, diminish the efficiency and quality of emitted light. Oak Ridge National Laboratory (ORNL) has the unique capability to thermally anneal QD structures at extremely high power densities for very short durations. This process, called pulse thermal processing (PTP), reduces the number of point defects while maintaining the size and shape of the original QD nanostructure. Therefore, the efficiency of the QD wavelength conversion layer is improved without altering the emission spectrum defined by the size distribution of theQD nanoparticles. The current research uses a thermal model to predict annealing temperatures during PTP and demonstrates up to a 300% increase in photoluminescence for QDs on passive substrates.

Duty, Chad E [ORNL; Bennett, Charlee J C [ORNL; Sabau, Adrian S [ORNL; Jellison Jr, Gerald Earle [ORNL; Boudreaux, Philip R [ORNL; Walker, Steven C [ORNL; Ott, Ronald D [ORNL

2011-01-01T23:59:59.000Z

474

Thermal reactor safety  

SciTech Connect (OSTI)

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.

Not Available

1980-06-01T23:59:59.000Z

475

Cermet fuel thermal conductivity  

E-Print Network [OSTI]

CERMET FUEL THERMAL CONDUCTIVITY A Thesis by JOHN MARK ALVIS, JR. Submitted to the Graduate College of Texas A&. M University in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Nuclear... particles of low conductivity dispersed in a metal matrix of high conductivity. A computer code was developed in order to compute the conductivity of cermet fuels as predicted by existing models and an additional model derived in this work...

Alvis, John Mark

1988-01-01T23:59:59.000Z

476

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

477

Methods of forming thermal management systems and thermal management methods  

DOE Patents [OSTI]

A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

Gering, Kevin L.; Haefner, Daryl R.

2012-06-05T23:59:59.000Z

478

Pedestrian Friendly Outdoor Lighting  

SciTech Connect (OSTI)

This GATEWAY report discusses the problems of pedestrian lighting that occur with all technologies with a focus on the unique optical options and opportunities offered by LEDs through the findings from two pedestrian-focused projects, one at Stanford University in California, and one at the Chautauqua Institution in upstate New York. Incorporating user feedback this report reviews the tradeoffs that must be weighed among visual comfort, color, visibility, efficacy and other factors to stimulate discussion among specifiers, users, energy specialists, and in industry in hopes that new approaches, metrics, and standards can be developed to support pedestrian-focused communities, while reducing energy use.

Miller, Naomi J.; Koltai, Rita; McGowan, Terry

2013-12-31T23:59:59.000Z

479

Advances in Lighting  

E-Print Network [OSTI]

colour rendition. The quartz-halogen incandescent lam s operate at higher temperatures, and have a somewhat higher efficacy, but they are rarely used except for special applicati ns. 3-2 High Intensity Discharge Lamps. Mercury is the grandfather... of the H.I.D. lamps. Its blue-green light, has been used almost exclusively for streetlighti and, often with colour-improving phospho it is still being used in industrial and commercial applications. Reactor-type ballasted mercury lamps can now...

Tumber, A. J.

1981-01-01T23:59:59.000Z

480

Lights, Conformational Change... Action!  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011 LawrenceEfeedstocksHomesLighting the

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


481

Lighting | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating Solar Powerstories on climateJuno Beach,October,Lighthouse Solar Jump to:Lighting Jump

482

On the transition from photoluminescence to thermal emission and its implication on solar energy conversion  

E-Print Network [OSTI]

Photoluminescence (PL) is a fundamental light-matter interaction, which conventionally involves the absorption of energetic photon, thermalization and the emission of a red-shifted photon. Conversely, in optical-refrigeration the absorption of low energy photon is followed by endothermic-PL of energetic photon. Both aspects were mainly studied where thermal population is far weaker than photonic excitation, obscuring the generalization of PL and thermal emissions. Here we experimentally study endothermic-PL at high temperatures. In accordance with theory, we show how PL photon rate is conserved with temperature increase, while each photon is blue shifted. Further rise in temperature leads to an abrupt transition to thermal emission where the photon rate increases sharply. We also show how endothermic-PL generates orders of magnitude more energetic photons than thermal emission at similar temperatures. Relying on these observations, we propose and theoretically study thermally enhanced PL (TEPL) for highly eff...

Manor, Assaf; Rotschild, Carmel

2014-01-01T23:59:59.000Z

483

Thermal Diffusivity and Viscosity of Suspensions of Disc Shaped Nanoparticles  

E-Print Network [OSTI]

In this work we conduct a transient heat conduction experiment with an aqueous suspension of nanoparticle disks of Laponite JS, a sol forming grade, using laser light interferometry. The image sequence in time is used to measure thermal diffusivity and thermal conductivity of the suspension. Imaging of the temperature distribution is facilitated by the dependence of refractive index of the suspension on temperature itself. We observe that with the addition of 4 volume % of nano-disks in water, thermal conductivity of the suspension increases by around 30%. A theoretical model for thermal conductivity of the suspension of anisotropic particles by Fricke as well as by Hamilton and Crosser explains the trend of data well. In turn, it estimates thermal conductivity of the Laponite nanoparticle itself, which is otherwise difficult to measure in a direct manner. We also measure viscosity of the nanoparticle suspension using a concentric cylinder rheometer. Measurements are seen to follow quite well, the theoretical relation for viscosity of suspensions of oblate particles that includes up to two particle interaction. This result rules out the presence of clusters of particles in the suspension. The effective viscosity and thermal diffusivity data show that the shape of the particle has a role in determining enhancement of thermophysical properties of the suspension.

Susheel S. Bhandari; K. Muralidhar; Yogesh M Joshi

2014-03-05T23:59:59.000Z

484

Ecological Consequences of Artificial Night Lighting  

E-Print Network [OSTI]

of Artificial Night Lighting Catherine Rich and Travisof artificial night lighting. This book provides editedage of modern urban lighting was ushered in. Coincidentally,

Piselli, Kathy

2006-01-01T23:59:59.000Z

485

LIGHTING CONTROLS: SURVEY OF MARKET POTENTIAL  

E-Print Network [OSTI]

REFERENCES Task Report to Lighting Systems Research,Berkeley Laboratory, "Lighting Control System Market1980). Task Report to Lighting Systems Research, Lawrence

Verderber, R.R.

2010-01-01T23:59:59.000Z

486

Demand Responsive Lighting: A Scoping Study  

E-Print Network [OSTI]

3 3.0 Previous Experience with Demand Responsive Lighting11 4.3. Prevalence of Lighting13 4.4. Impact of Title 24 on Lighting

Rubinstein, Francis; Kiliccote, Sila

2007-01-01T23:59:59.000Z

487

Municipal Consortium LED Street Lighting Workshop Presentations...  

Broader source: Energy.gov (indexed) [DOE]

A Rational View of LM-79 Reports, IES Files, and Product Variation Gary Steinberg, GE Lighting Solutions Solid-State Street Lighting: Calculating Light Loss Factors Dana Beckwith,...

488

Municipal Consortium LED Street Lighting Workshop Presentations...  

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

National Association of Energy Services Companies Calculating Light Loss Factors for Solid-State Lighting Systems Chad Stalker, Philips Lumileds Lighting Intro to MSSLC's...

489

Sandia National Laboratories: Light Creation Materials  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

TechnologiesLight Creation Materials Light Creation Materials Overview of SSL Light Creation Materials Different families of inorganic semiconductor materials can...

490

Photon echo studies of photosynthetic light harvesting  

E-Print Network [OSTI]

of the B800-B820 light-harvesting complex. Proc Natl Acadphotosynthetic light harvesting Elizabeth L. Read Æ Hohjaitransfer events in light harvesting. Here, we outline the

Read, Elizabeth L.; Lee, Hohjai; Fleming, Graham R.

2009-01-01T23:59:59.000Z

491

Sandia National Laboratories: Light Creation Materials  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

EFRCOverviewLight Creation Materials Light Creation Materials Overview of SSL Light Creation Materials Different families of inorganic semiconductor materials can contribute to...

492

Thermal control structure and garment  

DOE Patents [OSTI]

A flexible thermally conductive structure. The structure generally includes a plurality of thermally conductive yarns, at least some of which are at least partially disposed adjacent to an elastomeric material. Typically, at least a portion of the plurality of thermally conductive yarns is configured as a sheet. The yarns may be constructed from graphite, metal, or similar materials. The elastomeric material may be formed from urethane or silicone foam that is at least partially collapsed, or from a similar material. A thermal management garment is provided, the garment incorporating a flexible thermally conductive structure.

Klett, James W. (Knoxville, TN); Cameron, Christopher Stan (Sanford, NC)

2012-03-13T23:59:59.000Z

493

Thermal transport in CO2 laser irradiated fused silica: in situ measurements and analysis  

SciTech Connect (OSTI)

In situ spatial and temporal temperature measurements of pristine fused silica surfaces heated with a 10.6 {micro}m CO{sub 2} laser were obtained using an infrared radiation thermometer based on a Mercury Cadmium Telluride (MCT) camera. Laser spot sizes ranged from 250 {micro}m to 1000 {micro}m diameter with peak axial irradiance levels of 0.13 to 16 kW/cm{sup 2}. For temperatures below 2800K, the measured steady-state surface temperature is observed to rise linearly with both increasing beam size and incident laser irradiance. The effective thermal conductivity estimated over this range was approximately 2W/mK, in good agreement with classical calculations based on phonon heat capacities. Similarly, time-dependent temperature measurements up to 2000K yielded thermal diffusivity values which were close to reported values of 7 x 10{sup -7} m{sup 2}/s. Above {approx}2800K, the fused silica surface temperature asymptotically approaches 3100K as laser power is further increased, consistent with the onset of evaporative heat losses near the silica boiling point. These results show that in the laser heating regime studied here, the T{sup 3} temperature dependent thermal conductivity due to radiation transport can be neglected, but at temperatures above 2800K heat transport due to evaporation must be considered. The thermal transport in fused silica up to 2800K, over a range of conditions, can then be adequately described by a linear diffusive heat equation assuming constant thermal properties.

Yang, S T; Matthews, M J; Elhadj, S; Draggoo, V G; Bisson, S E

2009-07-07T23:59:59.000Z

494

THERMAL PERFORMANCE OF MANAGED WINDOW SYSTEMS  

E-Print Network [OSTI]

on Thermal Performance of the Exterior Envelopes ofof thermal loads resulting from the building envelope areThermal Test Facility, LhL-9653, prepared for the ASHRAE/DOE Conference-on"t:heThermal Performance the Exterior Envelope

Selkowitz, S. E.

2011-01-01T23:59:59.000Z

495

Thermal management systems and methods  

DOE Patents [OSTI]

A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

Gering, Kevin L.; Haefner, Daryl R.

2006-12-12T23:59:59.000Z

496

Light Duty Efficient Clean Combustion  

Broader source: Energy.gov (indexed) [DOE]

(order of the components) Thermal management strategy Fuel injection strategies VGT turbo operation VVA 13 This presentation does not contain any proprietary or confidential...

497

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

498

Received 10 Aug 2012 | Accepted 20 Feb 2013 | Published 27 Mar 2013 Broadband phonon mean free path contributions  

E-Print Network [OSTI]

thermal conductivity1­9. Because of its ubiquity in electronics, crystalline silicon (c-Si) has emerged in the bulk material. Kinetic theory defines the thermal conductivity as k ¼ CvsLG=3, where C is the volumetric heat capacity, vs is the speed of sound and LG is the average (or grey) MFP. For c-Si, kinetic

McGaughey, Alan

499

Integrated Vehicle Thermal Management Systems (VTMS) Analysis...  

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

Integrated Vehicle Thermal Management Power Electronic Thermal System Performance and Integration Characterization and Development of Advanced Heat Transfer Technologies...

500

Ultratough, Thermally Stable Polycrystalline Diamond/Silicon...  

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

Ultratough, Thermally Stable Polycrystalline DiamondSilicon Carbide Nanocomposites for Drill Bits Ultratough, Thermally Stable Polycrystalline DiamondSilicon Carbide...