Powered by Deep Web Technologies
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.


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

Interaction between Thermal Phonons and Dislocations in LiF  

Science Journals Connector (OSTI)

Thermal conductivity measurements on deformed LiF crystals from 0.04 to 0.8 K have indicated a strong polarization- and frequency-dependent dynamic scattering of thermal phonons by mobile dislocations. Heat-pulse experiments at 3.6 K have verified both the strength and polarization dependence of the scattering mechanism. The scattering of thermal phonons by sessile dislocations was too weak to be detected.

A. C. Anderson and M. E. Malinowski

1972-04-15T23:59:59.000Z

3

Phonon-cavity-enhanced low-temperature thermal conductance of a semiconductor nanowire with narrow constrictions  

Science Journals Connector (OSTI)

We study the effect of the phonon cavity lying in a narrow constriction of a semiconductor nanowire on the ballistic phonon thermal conductance at low temperatures. At higher temperatures, the thermal conductance of the nanowire with phonon cavity is lower than that of the nanowire without phonon cavity since more discontinuous interfaces scatter phonons. On the contrary, it is found that the cavity can enhance the thermal conductance at very low temperatures despite phonons are scattered by its interfaces. The enhancement originates from the coupling between more excited cavity modes in the phonon cavity and phonon modes in the constrictions.

Wei-Qing Huang; Gui-Fang Huang; Ling-Ling Wang; Bai-Yun Huang

2007-06-27T23:59:59.000Z

4

Thermal transport in phononic crystals: The role of zone folding effect  

Science Journals Connector (OSTI)

Recent experiments [Yu et al. Nature Nanotech 5 718 (2010); Tang et al. Nano Lett. 10 4279 (2010); Hopkins etal. Nano Lett. 11 107(2011)] on silicon based nanoscale phononic crystals demonstrated substantially reduced thermal conductivity compared to bulk Si which cannot be explained by incoherent phonon boundary scattering within the Boltzmann Transport Equation (BTE). In this paper partial coherent treatment of phonons where phonons are regarded as either wave or particles depending on their frequencies was considered. Phonons with mean free path smaller than the characteristic size of phononic crystals are treated as particles and the transport in this regime is modeled by BTE with phonon boundary scattering taken into account. On the other hand phonons with mean free path longer than the characteristic size are treated as waves. In this regime phonon dispersion relations are computed using the Finite Difference Time Domain(FDTD) method and are found to be modified due to the zone folding effect. The new phonon spectra are then used to compute phonon group velocity and density of states for thermal conductivitymodeling. Our partial coherent model agrees well with the recent experimental results on in-plane thermal conductivity of phononic crystals. Our study highlights the importance of zone folding effect on thermal transport in phononic crystals.

Edward Dechaumphai; Renkun Chen

2012-01-01T23:59:59.000Z

5

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

6

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

SciTech Connect

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

7

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

8

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

9

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

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

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

12

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

13

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

14

Research Article Building Thermal, Lighting,  

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

Article Building Thermal, Lighting, and Acoustics Modeling E-mail: yanda@tsinghua.edu.cn A detailed loads comparison of three building energy modeling programs: EnergyPlus, DeST and DOE-2.1E Dandan Zhu 1 , Tianzhen Hong 2 , Da Yan 1 (), Chuang Wang 1 1. Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084, China 2. Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA Abstract Building energy simulation is widely used to help design energy efficient building envelopes and HVAC systems, develop and demonstrate compliance of building energy codes, and implement building energy rating programs. However, large discrepancies exist between simulation results

15

Greenhouse Thermal Environment and Light Control  

Science Journals Connector (OSTI)

Greenhouse thermal environment results from the interactions among ... heating, ventilation, and cooling systems; supplemental lighting; and properties of the greenhouse crop are among the most important. As greenhouse

L. D. Albright

1997-01-01T23:59:59.000Z

16

Phonon-assisted transient electroluminescence in Si  

SciTech Connect

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

17

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

SciTech Connect

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

18

Correlation between structure, phonon spectra, thermal expansion, and thermomechanics of single-layer MoS2  

Science Journals Connector (OSTI)

Using first-principles simulation, the correlation between structure, phonon spectra, thermal expansion, and thermomechanics of single-layer MoS2 is established. The laminar structure results in the low-dimension ZA mode with a parabolic dispersion and negative Grüneisen constants (?), while the nonorthogonal covalent Mo–S bonds (or intralayer thickness) result in the interatom and interdirection vibrational hybridizations, which tend to increase ?. There is a negative-positive crossover in thermal expansion coefficient at 20 K, because of the competition between the modes with negative and positive ?. Although the phononic activation at finite temperatures has a stiffening effect on the bulk modulus, the dominant effect from thermal expansion softens the lattice upon heating. The intralayer thickness results in the similarity between the thermal expansions of SL and bulk MoS2. Our numerical results explicitly support that the experimentally measured thermal shifts of the Raman modes are dominated by multiphonon scattering, but not thermal expansion.

Liang Feng Huang; Peng Lai Gong; Zhi Zeng

2014-07-15T23:59:59.000Z

19

Thermal conductivity and phonon linewidths of monolayer MoS{sub 2} from first principles  

SciTech Connect

Using ab initio calculations, we have investigated the phonon linewidths and the thermal conductivity (?) of monolayer MoS{sub 2}. ? for a typical sample size of 1??m is 83 W/m K at room temperature in the completely rough edge limit, suggesting ? is not a limiting factor for the electronic application of monolayer MoS{sub 2}. ? can be further increased by 30% in 10??m sized samples. Due to strong anharmonicity, isotope enhancement of room temperature ? is only 10% for 1??m sized samples. However, linewidths can be significantly reduced, for instance, for Raman active modes A{sub 1g} and E{sub 2g}{sup 1}, in isotopically pure samples.

Li, Wu, E-mail: wu.li.phys2011@gmail.com; Carrete, J.; Mingo, Natalio, E-mail: natalio.mingo@cea.fr [CEA-Grenoble, 17 Rue des Martyrs, Grenoble 38000 (France)] [CEA-Grenoble, 17 Rue des Martyrs, Grenoble 38000 (France)

2013-12-16T23:59:59.000Z

20

Phonon Viscosity  

Science Journals Connector (OSTI)

The Boltzmann equation for thermal phonons in a dielectric crystal in the presence of a slowly varying but otherwise arbitrary, strain field is solved formally by expanding the phonon distribution function in terms of eigenfunctions of the collision operator. The macroscopic stress is then calculated in terms of the macroscopic strain and the phonon distribution function by using the quasiharmonic approximation. The resulting equation for the stress is of the same form as that given by thermoelasticity, except for the presence of an extra term which is linear in the strain rate. The coefficient of the strain rate in this term is identified with the phonon viscosity tensor, and a formal expression for this tensor is obtained.

H. J. MARIS

1969-12-15T23:59:59.000Z

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.


21

Influence of confined phonon modes on the thermal behavior of AlAs/GaAs quantum cascade structures  

Science Journals Connector (OSTI)

The thermal behavior of AlAs/GaAs quantum cascade structures is used to demonstrate the existence of confined and interface optical-phonon modes. The high conduction-band offset of this material system greatly improves the confinement of the electronic states and allows the realization of electroluminescence structures, where the optical power as a function of the temperature solely depends on the change of the upper-state lifetime induced by the longitudinal-optical-phonon population. We observed that the latter is proportional to the Bose-Einstein factor, with an appropriate phonon mode energy, which does not simply correspond to that of the GaAs bulk phonon (36-meV energy). In particular we show that the agreement between theory and experiment can be substantially improved when the confined and interface modes are taken into account in our calculation. Our results are corroborated by the threshold temperature dependence of lasers, with an active region based on similar structures.

C. Becker; C. Sirtori; H. Page; A. Robertson; V. Ortiz; X. Marcadet

2002-01-30T23:59:59.000Z

22

Phonon manipulation with phononic crystals.  

SciTech Connect

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

23

NEUTRON: a program for computing phonon extinction rules of inelastic neutron scattering and thermal diffuse scattering experiments  

Science Journals Connector (OSTI)

NEUTRON is a program for the determination of phonon extinction rules in inelastic neutron scattering experiments.

Kirov, A.K.

2003-07-19T23:59:59.000Z

24

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

25

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

26

Gallium arsenide thermal conductivity and optical phonon relaxation times from first-principles calculations  

E-Print Network (OSTI)

In this paper, thermal conductivity of crystalline GaAs is calculated using first-principles lattice dynamics. The harmonic and cubic force constants are obtained by fitting them to the force-displacement data from density ...

Luo, Tengfei

27

Waverly Light and Power - Residential Solar Thermal Rebates | Department of  

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

Solar Thermal Rebates Solar Thermal Rebates Waverly Light and Power - Residential Solar Thermal Rebates < Back Eligibility Residential Savings Category Heating & Cooling Solar Water Heating Maximum Rebate $3,500 Program Info Start Date 07/01/2009 State Iowa Program Type Utility Rebate Program Rebate Amount 30/sq. foot of collector area Provider Waverly Light and Power 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 application process. In addition, residential customers must obtain a county-issued permit prior to installing a solar water heating system. There is a limit of one rebate per address. Funding is available until the rebate fund is exhausted.

28

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

29

Phonons in twisted bilayer graphene  

Science Journals Connector (OSTI)

We theoretically investigate phonon dispersion in AA-stacked, AB-stacked, and twisted bilayer graphene with various rotation angles. The calculations are performed using the Born–von Karman model for the intralayer atomic interactions and the Lennard-Jones potential for the interlayer interactions. It is found that the stacking order affects the out-of-plane acoustic phonon modes the most. The difference in the phonon densities of states in the twisted bilayer graphene and in AA- or AB-stacked bilayer graphene appears in the phonon frequency range 90–110 cm?1. Twisting bilayer graphene leads to the emergence of different phonon branches—termed hybrid folded phonons—which originate from the mixing of phonon modes from different high-symmetry directions in the Brillouin zone. The frequencies of the hybrid folded phonons depend strongly on the rotation angle and can be used for noncontact identification of the twist angles in graphene samples. The obtained results and the tabulated frequencies of phonons in twisted bilayer graphene are important for the interpretation of experimental Raman data and in determining the thermal conductivity of these material systems.

Alexandr I. Cocemasov; Denis L. Nika; Alexander A. Balandin

2013-07-15T23:59:59.000Z

30

Experimental nonclassicality of single-photon-added thermal light states  

SciTech Connect

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

31

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

32

Wide-Area Thermal Processing of Light-Emitting Materials  

SciTech Connect

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

33

Detecting phonon blockade with photons  

SciTech Connect

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

NREL: Vehicles and Fuels Research - Light-Duty Vehicle Thermal...  

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

and passenger thermal comfort. Analogous to crash-test dummies, these manikins measure heat loss and skin temperature through numerous sensors, making it possible to efficiently...

35

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

36

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

37

Glass-like thermal conductivity in high efficiency thermoelectric materials  

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

Discusses strategies to design thermoelectric materials with extremely low lattice thermal conductivity through modifications of the phonon band structure and phonon relaxation time.

38

Lattice-Boltzmann modeling of phonon hydrodynamics  

Science Journals Connector (OSTI)

Based on the phonon Boltzmann equation, a lattice-Boltzmann model for phonon hydrodynamics is developed. Both transverse and longitudinal polarized phonons that interact through normal and umklapp processes are considered in the model. The collision term is approximated by the relaxation time model where normal and umklapp processes tend to relax distributions of phonons to their corresponding equilibrium distribution functions—the displaced Planck distribution and the Planck distribution, respectively. A macroscopic phonon thermal wave equation (PTWE), valid for the second-sound mode, is derived through the technique of Chapman-Enskog expansion. Compared to the dual-phase-lag (DPL) -based thermal wave equation, the PTWE has an additional fourth-ordered spatial derivative term. The fundamental difference between the two models is discussed through examining a propagating thermal pulse in a single-phased medium and the transient and steady-state transport phenomena on a two-layered structure subjected to different temperatures at boundaries. Results show that transport phenomena are significantly different between the two models. The behavior exhibited by the DPL model, as thermal wave behavior goes over to diffusive behavior, ?T??q is incompatible with any microscopic phonon propagating mode. Unlike the DPL model, in which ?T only has an effect on the transient phenomena, in the PTWE model ?T shows effects on phenomena at both transient and steady state. With the intrinsic compatibility to the microscopic state, discontinuous quantities, such as a jump of temperature at a boundary or at an interface, can be calculated naturally and straightforwardly with the present lattice-Boltzmann method.

Wen-Shu Jiaung and Jeng-Rong Ho

2008-06-23T23:59:59.000Z

39

Development of cryogenic phonon detectors based on CaMoO4 and ZnWO4 scintillating crystals for direct dark matter search experiments  

E-Print Network (OSTI)

This work reports on the development of the first phonon detectors based on CaMoO4 and ZnWO4 scintillating crystals for the CRESST-II experiment. In particular, a novel technique for the production of the ZnWO4 phonon detector with a separate thermometer carrier was investigated. The influence of the thermal and mechanical treatment on the scintillation light output of CaMoO4 and ZnWO4 crystals at room temperature is discussed.

I. Bavykina; G. Angloher; D. Hauff; M. Kiefer; F. Petricca; F. Proebst

2008-11-12T23:59:59.000Z

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

Infrared-induced single-phonon desorption of HD from LiF (100)  

Science Journals Connector (OSTI)

Low-intensity (10-5–10-2 watts/cm2) IR radiation at 9–15 ?m desorbs HD from 1.5–4.2-K LiF (100) at a rate (maximum 0.001 monolayer/s) proportional to the light intensity. This process is independent of temperature below 4.2 K, the velocity distribution is approximated by a temperature of 21 K, and the desorption efficiency increases with increasing wavelength. Desorption is attributed to single phonons created in a cascade following optical absorption. Thermal desorption is excluded as a possible mechanism except at high surface temperatures and coverages.

Paul M. Ferm; Sarah R. Kurtz; Kathryn A. Pearlstine; Gary M. McClelland

1987-06-15T23:59:59.000Z

43

Ballistic-phonon propagation in LiF  

Science Journals Connector (OSTI)

The interaction between high-frequency ballistic phonons and mass defects in LiF of natural isotopic composition has been studied with the use of a heat-pulse technique. Studies were made as a function of input power for samples of various length oriented along the [111] direction. The results indicate that surface imperfections have a profound effect on the transmission of high-frequency phonons. The experiments on suitably prepared surfaces yield a phonon scattering rate which is in excellent agreement with theoretical predictions and thermal conductivity measurements.

R. Soltis and J. Trivisonno

1984-11-15T23:59:59.000Z

44

PHONONS IN INTRINSIC JOSEPHSON SYSTEMS  

SciTech Connect

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

45

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

46

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

47

Phonons in narrow carbon nanotubes  

Science Journals Connector (OSTI)

Accurate calculations of the phonon dispersion relations, phonon density of states, and phonon eigenvectors of the narrow single-wall carbon nanotubes in optimized geometry are carried out. The method applied is based on the force constants for graphene which reflect the long-range character of the dynamical matrix. Further, the relaxation and symmetry imposed modifications of the force constants are performed and the calculations are carried out by means of the fully symmetry implemented POLSym code. Shortcomings of the widely used frozen phonon model are overcome. The results obtained are compared to the Raman scattering measurements on the zeolite-grown nanotubes.

Ivanka Miloševi?; Edib Dobardži?; Milan Damnjanovi?

2005-08-09T23:59:59.000Z

48

Phonon dispersion, phonon specific heat, and Debye temperature of high-temperature superconductors  

Science Journals Connector (OSTI)

A simple model representing the low-frequency acoustical and optical modes of the high-temperature superconductors (HTSC’s) leads to a surprisingly realistic representation of the low-temperature specific heats cv(T) and the corresponding Debye temperatures FTHETA(T) of the HTSC’s. The model allows us to relate the characteristics and peculiarities of cv(T) and FTHETA(T) directly to various features of the low-frequency phonon dispersion, and it is found that cv and FTHETA can exhibit rather well the identifiable features of phonon anomalies. For instance, a surprising result is that optic Einstein-like modes at ?E=2 THz (h?E/kB=96 K) in our model begin to have an effect at 6 K. This behavior has potentially important consequences for the procedure of separating the phonon contribution from the measured specific heat, in order to obtain the nonphonon specific-heat contributions. Another consequence of the occurrence of these Einstein modes is the presence of low-frequency phonons with large wave vectors, which means that umklapp scattering can begin to play a role at temperatures lower than usually assumed. This, in turn, may require a modification of the customary qualitative picture of the low-temperature electrical and thermal conductivities.

F. W. de Wette and A. D. Kulkarni

1992-12-01T23:59:59.000Z

49

Anisotropic phonon-dislocation scattering in deformed LiF  

Science Journals Connector (OSTI)

By direct imaging of ballistic phonons having equivalent temperatures near 4 K in LiF, we have found that a subset of fast-transverse phonons can propagate without scattering even in heavily deformed samples. The highly anisotropic phonon-scattering cross section is consistent with the concept of fluttering dislocations. The magnitude of the scattering cross section has been obtained for the first time. For small plastic deformation the measured cross section agrees with that calculated theoretically using a measured dislocation density. However, at large deformation the calculated cross section is too small, supporting the speculation that a larger density of dislocation dipoles may provide the dominant scattering. Also consistent with the concept of fluttering dislocations, ? irradiation reduces the phonon scattering created by deformation, presumably by pinning of the dislocations. It is demonstrated that the method of phonon imaging used here provides details of phonon scattering processes which are not available from conventional thermal-transport measurements, especially when the scattering is anisotropic.

G. A. Northrop; E. J. Cotts; A. C. Anderson; J. P. Wolfe

1983-05-15T23:59:59.000Z

50

Three-dimensional thermal analysis of wirelessly powered light-emitting systems  

Science Journals Connector (OSTI)

...geometrical parameters and thermal conductivities of the...bio-implanted applications. thermal analysis|wireless...wireless power, instead of batteries, could bring additional...battery replacement and battery biocompatibility. Recently...bio-integrated applications. The thermal behaviour of such systems...

2012-01-01T23:59:59.000Z

51

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

2007-02-17T23:59:59.000Z

52

Phonon dispersion in graphene  

Science Journals Connector (OSTI)

Taking into account constraints imposed by the lattice symmetry we calculate analytically [1] the phonon dispersion for graphene with interactions between first and second neighbors. We find that the out?of?plane (bending) modes are not coupled with in?plane modes and described only with two force constants one of which is determined by the corresponding Raman frequency and another by the smallest elastic constant C44. In contrast to calculations by Saito et al we find the linear dispersion of the bending (out?of?plane) mode around the ? point with a small but finite sound velocity =1.57 km/s. The sound velocity of this mode is very sensitive to small variations of the force constants. The sound velocities of in?plane modes are = 20.3 km/s and =13.1 km/s. Because of the lack of information for graphene we compare the present theory with experiments on graphite. The low phonon frequencies in the critical points turn out less than their values in graphite since the atoms in graphene are more free to move in the out?of?plane direction in comparison with graphite. Accuracy of the comparison can be estimated using the value of the observed splitting of the ZA and ZO' modes in graphite which is around 130 1/cm. [1] L.A. Falkovsky cond?mat/0702409.

Leonid A. Falkovsky

2008-01-01T23:59:59.000Z

53

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

54

Thermal and Magnetic Parameters in Solar Flares Derived from GOES X-Ray Light Curves  

Science Journals Connector (OSTI)

......6110 6190 6220 6310 Thermal and Magnetic Parameters in Solar Flares Derived from...impulsive phase of 20 solar flares and to estimate the thermal and magnetic parameters...parameters and the thermal ones, have been applied not only to solar flares, but also......

Tetsuya T. Yamamoto; Takashi Sakurai

2010-06-25T23:59:59.000Z

55

Structure of crystalline oxide ceramics studied by phonon spectroscopy  

SciTech Connect

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

56

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

SciTech Connect

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

57

Lighting  

SciTech Connect

The lighting section of ASHRAE standard 90.1 is discussed. It applies to all new buildings except low-rise residential, while excluding specialty lighting applications such as signage, art exhibits, theatrical productions, medical and dental tasks, and others. In addition, lighting for indoor plant growth is excluded if designed to operate only between 10 p.m. and 6 a.m. Lighting allowances for the interior of a building are determined by the use of the system performance path unless the space functions are not fully known, such as during the initial stages of design or for speculative buildings. In such cases, the prescriptive path is available. Lighting allowances for the exterior of all buildings are determined by a table of unit power allowances. A new addition the exterior lighting procedure is the inclusion of facade lighting. However, it is no longer possible to trade-off power allotted for the exterior with the interior of a building or vice versa. A significant change is the new emphasis on lighting controls.

McKay, H.N. (Hayden McKay Lighting Design, New York, NY (US))

1990-02-01T23:59:59.000Z

58

Human segmentation by geometrically fusing visible-light and thermal imageries  

Science Journals Connector (OSTI)

From depth sensors to thermal cameras, the increased availability of camera sensors beyond the visible spectrum has created many exciting applications. Most of these applications require combining information from these hyperspectral cameras with a regular ... Keywords: Human segmentation, Multi-camera fusion, Sensor fusion, Thermal cameras

Jian Zhao, Sen-Ching S. Cheung

2014-11-01T23:59:59.000Z

59

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

SciTech Connect

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

60

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

SciTech Connect

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

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

Thermal and Magnetic Parameters in Solar Flares Derived from GOES X-Ray Light Curves  

Science Journals Connector (OSTI)

......released amount of energy in a solar flare, and there...the derived thermal energy with the magnetic free energy. It is found that...Japan and Nobeyama Solar Radio Observatory...is a collaborative project involving the NRL......

Tetsuya T. Yamamoto; Takashi Sakurai

2010-06-25T23:59:59.000Z

62

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

63

PT-Symmetric Phonon Laser  

E-Print Network (OSTI)

By exploiting recent developments associated with coupled microcavities, we introduce the concept of PT-symmetric phonon laser with balanced gain and loss. This is accomplished by introducing gain to one of the microcavities such that it balances the passive loss of the other. In the vicinity of the gain-loss balance, a strong nonlinear relation emerges between the intracavity photon intensity and the input power. This then leads to a giant enhancement of both optical pressure and mechanical gain, resulting in a highly efficient phonon-lasing action. These results provide a promising approach for manipulating optomechanical systems through PT-symmetric concepts. Potential applications range from enhancing mechanical cooling to designing phonon-laser amplifiers.

H. Jing; Sahin K. Ozdemir; Xin-You Lv; Jing Zhang; Lan Yang; Franco Nori

2014-03-04T23:59:59.000Z

64

The effect of stiffness and mass on coupled oscillations in a phononic crystal  

SciTech Connect

Insight into phononic bandgap formation is presented using a first principles-type approach where phononic lattices are treated as coupled oscillators connected via massless tethers. The stiffness of the tethers and the mass of the oscillator are varied and their influences on the bandgap formation are deduced. This analysis is reinforced by conducting numerical simulations to examine the modes bounding the bandgap and highlighting the effect of the above parameters. The analysis presented here not only sheds light on the origins of gap formation, but also allows one to define design rules for wide phononic gaps and maximum gap-to-midgap ratios.

Baboly, M. Ghasemi; Su, M. F.; Alaie, S.; Goettler, D. F.; Leseman, Z. C., E-mail: zleseman@unm.edu [Department of Mechanical Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Reinke, C. M.; El-Kady, I. [Department of Advanced Photonic Microsystems, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Department of Advanced Photonic Microsystems, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

2013-11-15T23:59:59.000Z

65

Kapitza resistance between electron and phonon gases in the 1D case  

Science Journals Connector (OSTI)

......it saturates, as it does in the metallic case...that only at lambdat does electron-phonon coupling...approach proposed for the calculation of thermal resistance...the thermal conductance does not qualitatively depend...Waadeland H., Jones W. B. Handbook of Continued Fractions......

K. V. Reich

2013-01-01T23:59:59.000Z

66

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

SciTech Connect

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

67

Vibrational Energy-Spectra of Protein Molecules and Non-thermally Biological Effect of Infrared Light  

Science Journals Connector (OSTI)

The quantum energy-spectra including high excited states of the ... from metabolically active E. Coli. From this energy spectra we know that the infrared light with 1–3 ? m and 5– ... accordance with the non-line...

Xiao-feng Pang

2001-02-01T23:59:59.000Z

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

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

SciTech Connect

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

70

Light  

Science Journals Connector (OSTI)

Sunlight contains energy which can be directly converted into electricity in solar cells of various types. This is an example of what is called 'direct conversion', involving no moving parts or heat conversion processes. This chapter looks at photovoltaic and photoelectric devices and also at other ideas for using light energy, some of which operate in the infrared part of the spectrum. Solar electric power is a rapidly developing field, opening up many opportunities for novel applications, as well as requirements, including for storage, with one idea being solar-powered hydrogen production and then direct conversion to electricity in fuel cells. Direct conversion is not always efficient, and this chapter introduces the concept of 'energy return on energy invested'. In speculative mood this chapter also looks at the idea of a global grid, allowing daytime solar generation to be used on the night side of the planet.

David Elliott ? Pages 4-1 to 4-20

71

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

72

Phonon distribution in a model polariton system  

Science Journals Connector (OSTI)

We consider a simple model polariton problem and show that the phonons in this system will never exhibit sub-Poissonian statistics. We furthermore observe that the probability distribution of the phonons will be classical at all temperatures, although the polariton complex as a whole can have a nonclassical behavior below a threshold temperature whose value will depend on the photon-phonon coupling strength.

Sharmishtha Ghoshal and Ashok Chatterjee

1995-07-01T23:59:59.000Z

73

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

74

Plasmon-phonon coupling in graphene  

Science Journals Connector (OSTI)

Collective excitations of coupled electron-phonon systems are calculated for both monolayer and bilayer graphenes, taking into account the nonperturbative Coulomb coupling between electronic excitations in graphene and the substrate longitudinal-optical phonon modes. We find that the plasmon-phonon coupling in monolayer graphene is strong at all densities but in bilayer graphene the coupling is significant only at high densities satisfying the resonant condition ?pl??ph. The difference arises from the peculiar screening properties associated with chirality of graphene. Plasmon-phonon coupling explains the measured quasilinear plasmon dispersion in the long-wavelength limit, thus resolving a puzzle in the experimental observations.

E. H. Hwang; Rajdeep Sensarma; S. Das Sarma

2010-11-03T23:59:59.000Z

75

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

76

Strain-controlled thermal conductivity in ferroic twinned films  

E-Print Network (OSTI)

Large reversible changes of thermal conductivity are induced by mechanical stress, and the corresponding device is a key element for phononics applications. We show that the thermal conductivity ? of ferroic twinned thin ...

Li, Suzhi

77

Hybrid functional calculation of electronic and phonon structure of BaSnO{sub 3}  

SciTech Connect

Barium stannate, BaSnO{sub 3} (BSO), with a cubic perovskite structure, has been highlighted as a promising host material for the next generation transparent oxide electrodes. This study examined theoretically the electronic structure and phonon structure of BSO using hybrid density functional theory based on the HSE06 functional. The electronic structure results of BSO were corrected by extending the phonon calculations based on the hybrid density functional. The fundamental thermal properties were also predicted based on a hybrid functional calculation. Overall, a detailed understanding of the electronic structure, phonon modes and phonon dispersion of BSO will provide a theoretical starting-point for engineering applications of this material. - Graphical Abstract: (a) Crystal structure of BaSnO{sub 3}. The center ball is Ba and small (red) ball on edge is oxygen and SnO{sub 6} octahedrons are plotted as polyhedron. (b) Electronic band structure along the high symmetry point in the Brillouin zone using the HSE06 hybrid functional. (c) The phonon dispersion curve calculated using the HSE06 hybrid functional (d) Zone center lowest energy F{sub 1u} phonon mode. Highlights: Black-Right-Pointing-Pointer We report the full hybrid functional calculation of not only the electronic structure but also the phonon structure for BaSnO{sub 3}. Black-Right-Pointing-Pointer The band gap calculation of HSE06 revealed an indirect gap with 2.48 eV. Black-Right-Pointing-Pointer The effective mass at the conduction band minimum and valence band maximum was calculated. Black-Right-Pointing-Pointer In addition, the phonon structure of BSO was calculated using the HSE06 functional. Black-Right-Pointing-Pointer Finally, the heat capacity was calculated and compared with the recent experimental result.

Kim, Bog G., E-mail: boggikim@pusan.ac.kr [Department of Physics, Pusan National University, Pusan 609-735 (Korea, Republic of); Jo, J.Y. [Department of Physics, Pusan National University, Pusan 609-735 (Korea, Republic of); Cheong, S.W. [Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States)

2013-01-15T23:59:59.000Z

78

Phonon eigenvectors of chiral nanotubes  

Science Journals Connector (OSTI)

Although a commonly neglected fact, the physical properties of chiral carbon nanotubes may differ significantly 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 into axial and circumferential modes as in armchair and zig-zag nanotubes. The atomic displacement may, instead, point in any tangential direction and even show an angular dependence of its direction around the circumference, as the results of ab initio calculations demonstrate.

S. Reich; C. Thomsen; P. Ordejón

2001-10-26T23:59:59.000Z

79

Phonon dispersion of graphite J. Maultzsch  

E-Print Network (OSTI)

the acoustic branches below 400 cm-1 were measured by inelastic neutron scattering [1]. The optical phonons. The phonon dispersion of graphite was determined by inelastic X-ray scattering along the -K, K-M, and -K. This coupling dominates the scattering mechanism in both electronic transport and Raman scattering. Many

Nabben, Reinhard

80

Thermal Conductance of Thin Silicon Nanowires  

Science Journals Connector (OSTI)

The thermal conductance of individual single crystalline silicon nanowires with diameters less than 30 nm has been measured from 20 to 100 K. The observed thermal conductance shows unusual linear temperature dependence at low temperatures, as opposed to the T3 dependence predicted by the conventional phonon transport model. In contrast to previous models, the present study suggests that phonon-boundary scattering is highly frequency dependent, and ranges from nearly ballistic to completely diffusive, which can explain the unexpected linear temperature dependence.

Renkun Chen, Allon I. Hochbaum, Padraig Murphy, Joel Moore, Peidong Yang, and Arun Majumdar

2008-09-02T23:59:59.000Z

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.


81

Progress from DOE EF RC: Solid-State Solar-Thermal Energy Conversion Center (S3TEC)  

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

Introduction to the solid-state solar-thermal energy conversion center plus discussion on phonon transport and solar thermoelectric energy conversion

82

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

83

Screening effects in the electron–optical-phonon interaction  

Science Journals Connector (OSTI)

We show that recently reported [Alexandrov and Schrieffer, Phys. Rev. B 56, 13 731 (1997)] unusual hardening of optical phonons renormalized by the electron-phonon interaction is due to the neglect of screening effects. When the electron-ion interaction is properly screened, optical phonons soften in three dimensions. It is important that for short-wavelength optical phonons screening is static, while for long-wavelength optical phonons screening is dynamic. In two-dimensional and one-dimensional cases due to crossing of the nonperturbed optical mode with gapless plasmons, the spectrum of renormalized optical phonon–plasmon mode shows split momentum dependence.

Michael Reizer

2000-01-01T23:59:59.000Z

84

Anharmonic Three-Phonon Processes in Lithium Fluoride  

Science Journals Connector (OSTI)

The ultrasonic attenuation was measured in lithium fluoride for longitudinal and both transverse waves along the [110] axis at 0.4 and 1.0 Gc/sec from liquid-helium to room temperatures. After subtracting the low-temperature residual attenuation, the anharmonic attenuation of the slow transverse mode was found to vary linearly with frequency and as T3.5 below 30°K. For the fast transverse and the longitudinal modes, the temperature variation is more rapid and not expressible as a single power of temperature. The attenuation of the longitudinal mode showed some dependence on beam intensity. The attenuation of the slow transverse waves at 15°K was found to be somewhat higher than predicted by the Landau-Rumer theory. The strength of three-phonon processes had been deduced by Berman and Brock from the isotope thermal resistance of lithium fluoride. These results refer to phonons of frequencies around 300 Gc/sec. Assuming a linear variation with frequency, the present attenuation values agree to almost within a factor 2 with the values deduced by Berman and Brock at the same temperatures. Velocities of the three modes are given as functions of crystallographic direction.

J. de Klerk and P. G. Klemens

1966-07-15T23:59:59.000Z

85

TiO2/graphene composite from thermal reaction of graphene oxide and its photocatalytic activity in visible light  

Science Journals Connector (OSTI)

In this study, the P25 TiO2 nanoparticles and graphene sheets (GSs) composite were prepared from a facile thermal reaction of graphene oxide. Its microstructures and photocatalytic properties were ... nm in the a...

Yupeng Zhang; Chunxu Pan

2011-04-01T23:59:59.000Z

86

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

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

87

Theory of Raman scattering in coupled electron-phonon systems  

Science Journals Connector (OSTI)

The Raman spectrum is calculated for a coupled conduction-electron–phonon system in the zero-momentum-transfer limit. The Raman scattering is due to electron-hole excitations and phonons as well. The phonons of those branches that contribute to the electron self-energy and the correction of the electron-phonon vertex are assumed to have flat energy dispersion (the Einstein phonons). The effect of electron-impurity scattering is also incorporated. Both the electron-phonon interaction and the electron-impurity interaction cause the fluctuation of the electron distribution between different parts of the Fermi surface, which results in overdamped zero-sound modes of various symmetries. The scattering cross section is obtained by solving the Bethe-Salpeter equation. The spectrum shows a lower threshold at the smallest Einstein phonon energy when only the electron-phonon interaction is taken into consideration. When impurities are also taken into consideration, the threshold disappears.

K. Itai

1992-01-01T23:59:59.000Z

88

Polymer Nanofibers with Outstanding Thermal Conductivity and Thermal Stability: Fundamental Linkage between Molecular Characteristics and Macroscopic Thermal Properties  

E-Print Network (OSTI)

Polymer nanofibers with high thermal conductivities and outstanding thermal stabilities are highly desirable in heat transfer-critical applications such as thermal management, heat exchangers and energy storage. In this work, we unlock the fundamental relations between the thermal conductivity and thermal stability of polymer nanofibers and their molecular characteristics by studying the temperature-induced phase transitions and thermal transport of a series of polymer nanofibers. Ten different polymer nanofibers with systematically chosen molecular structures are studied using large scale molecular dynamics simulations. We found that high thermal conductivity and good thermal stability can be achieved in polymers with rigid backbones, exemplified by {\\pi}-conjugated polymers, due to suppressed segmental rotations and large phonon group velocities. The low probability of segmental rotation does not only prevent temperature-induced phase transition but also enables long phonon mean free paths due to reduced di...

Zhang, Teng; Luo, Tengfei

2014-01-01T23:59:59.000Z

89

Coherence of phonon avalanches in ruby  

Science Journals Connector (OSTI)

Phonon avalanches resonant with the optically inverted Zeeman-split ?(2E) doublet of Cr3+ have been measured and analyzed in a single crystal of 500-at. ppm ruby (Al2O3:Cr3+) with a geometry adapted to the study of coherence. A set of coherent Bloch equations governing the interacting acoustic wave and spin polarizations is found to provide an excellent description of the results, and to be far superior to incoherent rate equations for the phonon and level populations. The dephasing time conforms with the width of the inhomogeneously broadened transition connecting the ?(2E) states, which indicates that dephasing primarily occurs by the spread in frequencies.

L. G. Tilstra; A. F. M. Arts; H. W. de Wijn

2003-10-20T23:59:59.000Z

90

Electron-phonon coupling in the actinides  

Science Journals Connector (OSTI)

We have calculated the electron-phonon coupling constant for the first eight elements Fr–Pu in the seventh row of the Periodic Table within a fully relativistic formulation. The underlying self-consistent energy bands were obtained by means of the relativistic linear-muffin-tin-orbital method including angular momenta s, p, d, f, and g, and the electron-phonon parameters were estimated within the rigid-atomic-sphere approximation. The comparison with previous scalar relativistic results reveals significant changes only for Ac and Pu.

H. L. Skriver; O. Eriksson; I. Mertig; E. Mrosan

1988-02-01T23:59:59.000Z

91

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

92

Multipurpose characterization of glazing systems with silica aerogel: In-field experimental analysis of thermal-energy, lighting and acoustic performance  

Science Journals Connector (OSTI)

Abstract Thermal-energy, acoustic and lighting performance of innovative glazing systems with aerogel inclusion is evaluated through in-field experiments. The study is carried out by monitoring two dedicated prototype buildings located in central Italy, and the consistency of results with in-lab analyses is investigated. Analyses showed that aerogel can decrease energy consumption for heating by up to 50% in winter, and its capability to keep the thermal zone warmer even several days after that the heating system is switched off. Acoustic analyses confirmed in-lab measurements, showing aerogel capability to increase the façade acoustic insulation index by 3 dB. Lighting analyses showed aerogel effect to lower the daily average illuminance level by about 10% during sunny days. In cloudy weather conditions, with low level of solar radiation and indoor illuminance, the effect was relatively higher. In those cases when windows include shading elements such as protruding roof or deep window pad, aerogel effect was not clearly identified through continuous monitoring. The results of this integrated in-field experimental campaign showed that aerogel filled glazing cameras represent effective and innovative solutions for energy saving in winter, useful for improving acoustic façade performance with limited penalties in terms of daylighting.

Franco Cotana; Anna Laura Pisello; Elisa Moretti; Cinzia Buratti

2014-01-01T23:59:59.000Z

93

Exciton-phonon bound complex in single-walled carbon nanotubes revealed by high-field magneto-optical spectroscopy  

SciTech Connect

High-field magneto-optical spectroscopy was performed on highly enriched (6,5) single-walled carbon nanotubes. Spectra of phonon sidebands in both 1st and 2nd sub-bands were unchanged by an external magnetic field up to 52?T. The dark K-momentum singlet (D-K-S) exciton, which plays an important role for the external quantum efficiency of the system for both sub-bands in the near-infrared and the visible light region, respectively, was clarified to be the origin of the phonon sidebands.

Zhou, Weihang; Nakamura, Daisuke; Takeyama, Shojiro, E-mail: takeyama@issp.u-tokyo.ac.jp [Institute for Solid State Physics, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)] [Institute for Solid State Physics, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Sasaki, Tatsuya; Saito, Hiroaki [Institute for Solid State Physics, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan) [Institute for Solid State Physics, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Department of Applied Physics, University of Tokyo, Hongo 113-8656 (Japan); Liu, Huaping [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)] [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Kataura, Hiromichi [Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562 (Japan)] [Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562 (Japan)

2013-12-02T23:59:59.000Z

94

Effects of electron-electron and electron-phonon interactions in weakly disordered conductors and heterostructures  

Science Journals Connector (OSTI)

We investigate quantum corrections to the conductivity due to the interference of electron-electron (electron-phonon) scattering and elastic electron scattering from impurities and defects in weakly disordered conductors. The interference corrections are proportional to the Drude conductivity and have various temperature dependences. The electron-electron interaction results in a T2 ln T correction in bulk conductors. In a quasi-two-dimensional (quasi-2D) conductor, d1) this correction is linear in temperature and differs from that for 2D electrons [G. Zala et al., Phys. Rev. B 64, 214204 (2001)] by a numerical factor. In quasi-one-dimensional conductors with 3D and 2D electron spectra (a wire with radius rphonons gives the T2 ln T correction. In bulk semiconductors the interaction of electrons with thermal phonons via the screened deformation potential results in a T6 term and via unscreened deformation potential leads to a T2 term. For a two-dimensional electron gas in heterostructures, the screened deformation potential gives rise to a T4 term and the unscreened deformation potential leads to a T2 ln T term. At low temperatures the interference of electron-electron and electron-impurity scattering dominates in the temperature-dependent conductivity. At higher temperatures the conductivity is determined by the electron-phonon-impurity interference, which prevails over pure electron-phonon scattering in a wide temperature range, which extends with increasing disorder.

A. Sergeev; M. Yu. Reizer; V. Mitin

2004-02-18T23:59:59.000Z

95

Enhancing phonon flow through one-dimensional interfaces by impedance matching  

Science Journals Connector (OSTI)

We extend concepts from microwave engineering to thermal interfaces and explore the principles of impedance matching in 1D. The extension is based on the generalization of acoustic impedance to nonlinear dispersions using the contact broadening matrix ?(?) extracted from the phonon self energy. For a single junction we find that for coherent and incoherent phonons the optimal thermal conductance occurs when the matching ?(?) equals the Geometric Mean of the contact broadenings. This criterion favors the transmission of both low and high frequency phonons by requiring that (1) the low frequency acoustic impedance of the junction matches that of the two contacts by minimizing the sum of interfacial resistances and (2) the cut-off frequency is near the minimum of the two contacts thereby reducing the spillage of the states into the tunneling regime. For an ultimately scaled single atom/spring junction the matching criterion transforms to the arithmetic mean for mass and the harmonic mean for spring constant. The matching can be further improved using a composite graded junction with an exponential varying broadening that functions like a broadband antireflection coating. There is however a trade off as the increased length of the interface brings in additional intrinsic sources of scattering.

2014-01-01T23:59:59.000Z

96

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

SciTech Connect

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

97

On Renormalized Einstein Phonons and Green Function  

Science Journals Connector (OSTI)

The problem of interacting Einstein phonons is treated by deriving the Green function through a functional derivative approach employing the Hamiltonian of Born-von Kaacute;rmán. In this case the Dyson equation yields an exact solution for the Green function whose poles are the frequency versus wave vector dispersion relation. The Green function is used to calculate the internal energy and the Helmholtz free energy of the crystal. The latter is derived by integrating the average interactionenergy over the coupling parameter.

Ramesh C. Shukla; Eric R. Muller

1971-01-01T23:59:59.000Z

98

Temperature Dependence of Microwave Phonon Attenuation  

Science Journals Connector (OSTI)

Measurements of the temperature dependence of the attenuation of 9-Gc/sec phonons are presented. They include measurements on crystals of quartz, CdS, GaAs, Ge, Si, CaF2, Al2O3, and MgO in several directions and modes of polarization. The attenuation in most of the materials is proportional to Tn, where the average value of n=4.1±1.2 for the fast transverse waves, 4.0±1.7 for the slow transverse waves, 4.8±1.4 for the longitudinal waves. For MgO and Al2O3 the attenuation is proportional to the frequency of the sound between 3 and 9 Gc/sec. An empirical correlation of the data is that the attenuation of 9-Gc/sec phonons is 3 dB/cm when (T?)?0.1, where ?=Debye temperature of the crystal . Values of the third-order elastic constants are used to make absolute comparisons of the theory of attenuation by three-phonon processes with the data. The agreement is good in some cases but not in others.

M. Pomerantz

1965-07-19T23:59:59.000Z

99

Thermal Conductivity of LiF and NaF and the Ziman Limit  

Science Journals Connector (OSTI)

A model calculation of lattice thermal conductivity is presented and applied to measurements on LiF and NaF crystals of high purity. The treatment is in the spirit of a Callaway analysis, but at a somwhat more fundamental level: The Ziman variational principle for thermal conductivity derived from the phonon Boltzmann equation is used, with the phonon distribution function approximated by a displaced Planck part plus another term reducing the deviation from equilibrium for high-frequency phonons. An isotropic Debye approximation for the phonon spectra of LiF and NaF gives a good fit to the conductivity data, with only two semi-adjustable parameters (Grüneisen constant and a zone-edge longitudinal phonon frequency) for the anharmonic contribution. The most important feature of the calculation is the failure of the thermal conductivity to approach the Ziman limit of resistanceless phonon-phonon N processes. This is due to the important role played by high-frequency phonons in thermal conduction. Even for an infinite perfect crystal at arbitrarily low temperatures, the Ziman limit underestimates the conductivity by at least 50%. If this prediction is correct, it is not a peculiarity of LiF and NaF alone, and should be of importance for the theory of second-sound propagation in insulators.

David Benin

1972-03-15T23:59:59.000Z

100

Mode dependent lattice thermal conductivity of single layer graphene  

SciTech Connect

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

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

Theoretical studies on phonon spectra of high temperature superconductor YBaCuFeO5  

Science Journals Connector (OSTI)

The role of superconductivity can be understood by the assignments of spectral features to lattice vibrations. Raman and infrared studies have contributed significantly to the explication of high Tc superconductor mechanics. In the present work, normal coordinate calculations have been carried out to study the vibrational analysis of perovskite like antiferromagnetic compound YBaCuFeO5. It is important to have knowledge of phonon frequency spectrum for the interpretation of physical properties such as thermal, elastic, infrared, etc., which can be achieved by means of theoretical models of lattice dynamics. A three-body force shell model (TBSM) which takes into account many body interactions is applied to study the lattice dynamics of high Tc superconductors YBaCuFeO5. For the interpretation of infrared and Raman spectrum, the phonon frequencies at the centre of Brillouin zone are presented and vibrational assignments are discussed. The calculations yield not only the phonon frequencies at the centre, but also throughout the Brillouin zone.

A. Punitha; Sujin P. Jose; S. Mohan

2012-01-01T23:59:59.000Z

102

Rotational character change of the one-phonon and two-phonon $?$ vibration in odd-$A$ nuclei  

E-Print Network (OSTI)

\\item[Background] The $\\gamma$ vibration is the most typical low-lying collective motion prevailing the nuclear chart. But only few one-phonon rotational bands in odd-$A$ nuclei have been known. Furthermore, two-phonon states, even the band head, have been observed in a very limited number of nuclides not only of odd-$A$ but even-even. \\item[Purpose] Among them, that in $^{105}$Mo is unique in that Coriolis effects are expected to be stronger than in $^{103}$Nb and $^{105}$Nb on which theoretical studies were reported. Then the purpose of the present work is to study $^{105}$Mo paying attention to rotational character change of the one-phonon and two-phonon bands in comparison with the present author's previous studies on $^{103}$Nb and $^{105}$Nb. \\item[Method] The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. \\item[Results] The present model reproduces the observed yrast zero-phonon and one-phonon bands well. The emerging general feature of the rotational character change from low spin to high spin is elucidated. In particular, the reason why the one-phonon band does not exhibit signature splitting is clarified. The calculated collectivity of the two-phonon states, however, is located higher than observed. \\item[Conclusions] The observed spectra of the yrast zero-phonon and one-phonon bands have been reproduced well. But properties of the two-phonon states, in particular the anharmonicity of the spectra, have not been accounted for.

Masayuki Matsuzaki

2014-10-21T23:59:59.000Z

103

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

104

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

105

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

106

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

107

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

SciTech Connect

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

108

Exciton-exciton and exciton-phonon interactions in an interfacial GaAs quantum dot ensemble  

Science Journals Connector (OSTI)

Using optical two-dimensional Fourier transform spectroscopy, we report temperature- and excitation-density-dependent measurements of the homogeneous linewidth of the exciton ground-state transition in a single layer of interfacial GaAs quantum dots (QDs). We show that the homogeneous linewidth increases nonlinearly with temperature from 6 to 50 K and that the thermal broadening is well described by an activation term and offset. The absence of a phonon-activation peak in the two-dimensional spectra reveals that elastic scattering of excitons with acoustic phonons via virtual transitions between the ground and excited states significantly contributes to the thermal broadening. We find that the combination of increasing virtual activation energy and exciton-phonon coupling strength with decreasing QD size results in greater thermal broadening for excitons localized in smaller QDs. The homogeneous linewidth also exhibits a strong excitation-density dependence and is shown to increase linearly as the photon density increases from 2×1011 to 1×1012 photons pulse-1 cm-2 at 6 K. This trend is attributed to strong coupling of excitons within the same QD and is independent of the quantum-well exciton population density.

G. Moody; M. E. Siemens; A. D. Bristow; X. Dai; D. Karaiskaj; A. S. Bracker; D. Gammon; S. T. Cundiff

2011-03-23T23:59:59.000Z

109

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

110

Phonon Quasidiffusion in Cryogenic Dark Matter Search Large Germanium Detectors  

E-Print Network (OSTI)

We present results on quasidiffusion studies in large, 3 inch diameter, 1 inch thick [100] high purity germanium crystals, cooled to 50 mK in the vacuum of a dilution refrigerator, and exposed with 59.5 keV gamma-rays from an Am-241 calibration source. We compare data obtained in two different detector types, with different phonon sensor area coverage, with results from a Monte Carlo. The Monte Carlo includes phonon quasidiffusion and the generation of phonons created by charge carriers as they are drifted across the detector by ionization readout channels.

S. W. Leman; B. Cabrera; K. A. McCarthy; M. Pyle; R. Resch; B. Sadoulet; K. M. Sundqvist; P. L. Brink; M. Cherry; E. Do Couto E Silva; E. Figueroa-Feliciano; N. Mirabolfathi; B. Serfass; A. Tomada

2011-07-18T23:59:59.000Z

111

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

112

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.

113

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

114

Study of Thermal Properties of Graphene-Based Structures Using the Force Constant Method  

E-Print Network (OSTI)

to have an extremely low thermal conductivity because of the strong sensitivity of phonon transport be excellent candidates for thermoelectric applications that require very low values of thermal conductivity, 2012) Abstract The thermal properties of graphene-based materials are theoretically investigated

115

Phonon Transport and Thermodynamics Probed with Neutron Scattering...  

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

Phonon Transport and Thermodynamics Probed with Neutron Scattering Oct 22 2014 10:00 AM - 11:00 AM Olivier Delaire, Scattering and Thermophysics Group, MSTD, ORNL, Oak Ridge...

116

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.

117

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

118

Spectral-Spatial Diffusion of Resonantly Trapped Phonons  

Science Journals Connector (OSTI)

The observation of spectral and spatial diffusion of phonons in an Al2O3 crystal containing both inelastic and resonance-elastic scattering centers (two different species of impurity ions) is reported. Phonons were generated by pulsed far-infrared excitation at a fixed frequency and monitored by time-resolved detection at a different frequency. Analysis of the data leads to the determination of the basic parameters of spectral and spatial diffusion.

U. Happek; T. Holstein; K. F. Renk

1985-05-13T23:59:59.000Z

119

Thermal conductivity of graphene nanoribbons in noble gaseous environments  

SciTech Connect

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

120

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

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

Nanoscale thermal transport. II. 2003–2012  

SciTech Connect

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

122

Phonon spectrum and interaction between nanotubes in single-walled carbon nanotube bundles at high pressures and temperatures  

SciTech Connect

The Raman spectra of single-walled carbon nanotubes at temperatures up to 730 K and pressures up to 7 GPa have been measured. The behavior of phonon modes and the interaction between nanotubes in bundles have been studied. It has been found that the temperature shift of the vibrational G mode is completely reversible, whereas the temperature shift of radial breathing modes is partially irreversible and the softening of the modes and narrowing of phonon bands are observed. The temperature shift and softening of radial breathing modes are also observed when samples are irradiated by laser radiation with a power density of 6.5 kW/mm{sup 2}. The dependence of the relative frequency {Omega}/{Omega}{sub 0} for G{sup +} and G{sup -} phonon modes on the relative change A{sub 0}/A in the triangular lattice constant of bundles of nanotubes calculated using the thermal expansion coefficient and compressibility coefficient of nanotube bundles shows that the temperature shift of the G mode is determined by the softening of the C-C bond in nanotubes. An increase in the equilibrium distances between nanotubes at the breaking of random covalent C-C bonds between nanotubes in bundles of nanotubes is in my opinion the main reason for the softening of the radial breathing modes.

Meletov, K. P., E-mail: mele@issp.ac.ru [Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation)

2012-12-15T23:59:59.000Z

123

Rotational character change of the one-phonon and two-phonon $\\gamma$ vibration in odd-$A$ nuclei  

E-Print Network (OSTI)

\\item[Background] The $\\gamma$ vibration is the most typical low-lying collective motion prevailing the nuclear chart. But only few one-phonon rotational bands in odd-$A$ nuclei have been known. Furthermore, two-phonon states, even the band head, have been observed in a very limited number of nuclides not only of odd-$A$ but even-even. \\item[Purpose] Among them, that in $^{105}$Mo is unique in that Coriolis effects are expected to be stronger than in $^{103}$Nb and $^{105}$Nb on which theoretical studies were reported. Then the purpose of the present work is to study $^{105}$Mo paying attention to rotational character change of the one-phonon and two-phonon bands in comparison with the present author's previous studies on $^{103}$Nb and $^{105}$Nb. \\item[Method] The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. \\item[Results] The present model reproduces the observed yrast zero-phonon and...

Matsuzaki, Masayuki

2014-01-01T23:59:59.000Z

124

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

125

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

126

High temperature phonon dispersion in graphene using classical molecular dynamics  

SciTech Connect

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

127

Exciton formation assisted by LO phonons in quantum wells  

Science Journals Connector (OSTI)

Kinetics of exciton formation involving LO phonons is investigated in quantum wells. Considering the formation of an exciton from a free excited electron-hole pair due to LO-phonon emission, an expression is derived for the rate of formation of an exciton as a function of carrier densities, temperature, and wave vector K? of the center of mass of excitons in quantum wells, and the formation time of an exciton is also calculated. The theory is applied to GaAs quantum wells, in which it is found that the exciton formation dominantly occurs at K??0.

I.-K. Oh, Jai Singh, A. Thilagam, and A. S. Vengurlekar

2000-07-15T23:59:59.000Z

128

Direct Conversion of Light into Work - Energy Innovation Portal  

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

Thermal Solar Thermal Industrial Technologies Industrial Technologies Find More Like This Return to Search Direct Conversion of Light into Work Lawrence Berkeley National...

129

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

130

Enhanced Electron-Phonon Coupling at Metal Surfaces  

SciTech Connect

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

131

Phonons in a nanoparticle mechanically coupled to a substrate  

Science Journals Connector (OSTI)

The discrete nature of the vibrational modes of an isolated nanometer-scale solid dramatically modifies its low-energy electron and phonon dynamics from that of a bulk crystal. However, nanocrystals are usually coupled—even if only weakly so—to an environment consisting of other nanocrystals, a support matrix, or a solid substrate, and this environmental interaction will modify the vibrational properties at low frequencies. In this paper we investigate the modification of the vibrational modes of a spherical insulating nanoparticle caused by a weak mechanical coupling to a semi-infinite substrate. The phonons of the bulk substrate act as a bath of harmonic oscillators, and the coupling to this reservoir shifts and broadens the nanoparticle’s modes. The vibrational density of states in the nanoparticle is obtained by solving the Dyson equation for the phonon propagator, and we show that environmental interaction is especially important at low frequencies. As a probe of the modified phonon spectrum, we consider nonradiative energy relaxation of a localized electronic impurity state in the nanoparticle, for which good agreement with a recent experiment is found.

Kelly R. Patton and Michael R. Geller

2003-04-30T23:59:59.000Z

132

ccsd00000617 Phonon dispersion in the 1-layer cuprate  

E-Print Network (OSTI)

neutron scattering. PACS numbers: 74.72.Jt, 74.25.Kc, 78.70.Ck x Present address: Physique des Milieux-ray scattering (IXS). The experimental phonon dispersion and the dynamical structure factor are compared for volumes smaller then 0.1 mm 3 (see Bertinotti et al 1997). Such a size is insuÃ?cient for inelastic neutron

133

Comparative study of the electronic structure, phonon spectra, and electron-phonon interaction of ZrB2 and TiB2  

SciTech Connect

The electronic structure, optical and x-ray absorption spectra, angledependence of the cyclotron masses and extremal cross sections of the Fermisurface, phonon spectra, electron-phonon Eliashberg and transport spectralfunctions, temperature dependence of electrical resistivity of the MB2 (M=Tiand Zr) diborides were investigated from first principles using the fullpotential linear muffin-tin orbital method. The calculations of the dynamicmatrix were carried out within the framework of the linear response theory. Agood agreement with experimental data of optical and x-ray absorption spectra,phonon spectra, electron-phonon spectral functions, electrical resistivity,cyclotron masses and extremal cross sections of the Fermi surface was achieved.

Sichkar, S. M. [Institute of Metal Physics; Antonov, V. N. [Ames Laboratory; Antropov, V. P. [Ames Laboratory

2013-02-28T23:59:59.000Z

134

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

SciTech Connect

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

135

Self-consistent thermal simulation of GaAs/Al0.45Ga0.55As quantum cascade lasers  

Science Journals Connector (OSTI)

This paper presents a self-consistent thermal model for quantum cascade lasers (QCLs) that takes into account the nonuniform heat generation distribution in the active region as well as the temperature dependences of the heat generation rate and thermal ... Keywords: Heating, Monte Carlo, Nonlinear effects, Phonon transport, Quantum cascade lasers, Thermal model

Y. B. Shi; Z. Aksamija; I. Knezevic

2012-03-01T23:59:59.000Z

136

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

137

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

138

Cross-plane thermal properties of transition metal dichalcogenides  

SciTech Connect

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

139

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

SciTech Connect

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

140

The change of microstructure and thermal properties in ion irradiated carbon nanotube mats as a function of ion penetration depth  

SciTech Connect

A stack of three carbon nanotube (CNT) mats was irradiated with 3 MeV He ions. The change in structural and thermal properties of individual mats as a function of ion penetration depth was characterized using electron microscopy and laser flash techniques. Ion irradiation can enhance thermal conductivity of the mats by introducing inter-tube displacements, which improve phonon transport across adjacent nanotubes. The enhancement, however, is reduced at higher damage levels due to the increasing phonon-defect scattering within the tubes. This study demonstrates the feasibility of using ion irradiation to manipulate thermal transport in carbon nanotubes.

Aitkaliyeva, A. [Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States)] [Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States); Shao, L. [Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States) [Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States); Department of Nuclear Engineering, Texas A and M University, College Station, Texas 77843 (United States)

2013-02-11T23:59:59.000Z

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

Phonon drag of electrons in Ag{sub 2}S  

SciTech Connect

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

142

Magnon damping by magnon-phonon coupling in manganese perovskites  

SciTech Connect

Inelastic neutron scattering was used to systematically investigate the spin-wave excitations (magnons) in ferromagnetic manganese perovskites. In spite of the large differences in the Curie temperatures (T{sub C}'s) of different manganites, their low-temperature spin waves have very similar dispersions with the zone-boundary magnon softening and broadening that cannot be explained by the canonical double exchange mechanism. From the wave-vector dependence of the magnon lifetime effects and its correlation with the dispersions of the optical-phonon modes, we argue that a strong magnetoelastic (magnon-phonon) coupling is responsible for the observed low-temperature anomalous spin dynamical behavior of the manganites. (c) 2000 The American Physical Society.

Dai, Pengcheng [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States)] [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Hwang, H. Y. [Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States)] [Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States); Zhang, Jiandi [Department of Physics, Florida International University, University Park, Miami, Florida 33199 (United States)] [Department of Physics, Florida International University, University Park, Miami, Florida 33199 (United States); Fernandez-Baca, J. A. [Oak Ridge Natinal Laboratory, Oak Ridge, Tennessee 37831-6393 (United States)] [Oak Ridge Natinal Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Cheong, S.-W. [Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States) [Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States); Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States); Kloc, C. [Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States)] [Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States); Tomioka, Y. [Joint Research Center for Atom Technology (JRCAT), Tsukuba 305 8562, (Japan)] [Joint Research Center for Atom Technology (JRCAT), Tsukuba 305 8562, (Japan); Tokura, Y. [Joint Research Center for Atom Technology (JRCAT), Tsukuba 305 8562, (Japan) [Joint Research Center for Atom Technology (JRCAT), Tsukuba 305 8562, (Japan); Department of Applied Physics, University of Tokyo, Tokyo 113 8656, (Japan)

2000-04-01T23:59:59.000Z

143

Generation of an Covariance Matrix by Monte Carlo Sampling of the Phonon Frequency Spectrum  

Science Journals Connector (OSTI)

Abstract Formats and procedures are currently established for representing covariances in the ENDF library for many reaction types. However, no standard exists for thermal neutron inelastic scattering cross section covariance data. These cross sections depend on the material's dynamic structure factor, or S ( ? , ? ) . The structure factor is a function of the phonon density of states (DOS). Published ENDF thermal neutron scattering libraries are commonly produced by modeling codes, such as NJOY/LEAPR, which utilize the DOS as the fundamental input and directly output the S ( ? , ? ) matrix. To calculate covariances for the computed S ( ? , ? ) data, information about uncertainties in the DOS is required. The DOS may be viewed as a probability distribution function of available atomic vibrational energy states in a solid. In this work, density functional theory and lattice dynamics in the harmonic approximation were used to simulate the structure of silicon dioxide (?-quartz) to produce the DOS. A range for the variation in the partial DOS for silicon in ?-quartz was established based on limits of variation in the crystal lattice parameters. Uncertainty in an experimentally derived DOS may also be incorporated with the same methodology. A description of possible variation in the DOS allowed Monte Carlo generation of a set of perturbed DOS spectra which were sampled to produce the S ( ? , ? ) covariance matrix for scattering with silicon in ?-quartz. With appropriate sensitivity matrices, it is shown that the S ( ? , ? ) covariance matrix can be propagated to generate covariance matrices for integrated cross sections, secondary energy distributions, and coupled energy-angle distributions.

J.C. Holmes; A.I. Hawari

2014-01-01T23:59:59.000Z

144

Thermal expansion and lattice dynamics of RB66 compounds at low temperatures  

SciTech Connect

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

145

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

SciTech Connect

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

146

Thermal optimization of high power LED arrays with a fin cooling system  

Science Journals Connector (OSTI)

In this paper, we describe an optimization process of thermal design for the light lamp which utilizes the Light Emitting Diode (LED) module as a lighting source. The thermal performance of the LED module was sho...

Sun Ho Jang; Moo Whan Shin

2011-10-01T23:59:59.000Z

147

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

SciTech Connect

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

148

Contributions of Scattering of Polaritons by Phonons to Emission of Radiation by Solids  

Science Journals Connector (OSTI)

A brief discussion of the coupled exciton-photon (polariton) fields is given. Probabilities per unit time associated with the scattering of polaritons by acoustical and optical phonons are calculated to terms of first order in the exciton-phonon interaction. Results applicable to cadmium sulfide at 77°K are obtained. Two phonon-assisted emission bands are found. One is positioned approximately one longitudinal optical (LO) phonon below the exciton-photon resonance energy EA, and is due to the inelastic scattering of polaritons above the knee of the lowest-lying polariton branch to states below the knee with the simultaneous creation of LO phonons. The second band is positioned very close to EA and is also due primarily to LO-phonon scattering.

W. C. TAIT and R. L. WEIHER

1969-02-15T23:59:59.000Z

149

Superfluorescence and amplified spontaneous emission of 29-cm-1 phonons in ruby  

Science Journals Connector (OSTI)

Superfluorescence and amplified spontaneous emission of 29-cm-1 phonons are observed following inversion of the E¯(2E)-2A¯(2E) acoustic transition of Cr3+ in ruby. The conditions for both of these manifestations of phonon avalanches are selected via the Cr3+ concentration. Superfluorescence is described in terms of a pendulum equation of the acoustic Bloch vector. Rate equations of the level and phonon populations account for amplified spontaneous emission.

M. H. F. Overwijk; J. I. Dijkhuis; H. W. de Wijn

1990-10-15T23:59:59.000Z

150

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

151

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

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

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

152

Electron-phonon interactions and superconductivity in Si, Ge, and Sn  

Science Journals Connector (OSTI)

The pseudopotential-total-energy method is used to calculate the phonon frequency, the electron density of states at the Fermi level, and the electron-phonon coupling constant for the group-IV elements in the metallic ?-Sn structure. For these elements, the normal-state behavior is similar to that found in other simple and transition metals; the phonon frequencies, force constants, and electron-phonon matrix elements increase with increasing average electron density. With use of a semiempirical treatment of the electron-phonon coupling calculated for one phonon wave vector, the superconducting transition temperatures at normal and high pressures are examined. The superconducting transition temperature decreases while the magnitude of its pressure coefficient increases in going to heavier elements. This behavior is in good agreement with experiment. For Si and Ge, the superconducting behavior is similar to that of white tin. Because of competition and compensation between the cutoff in the phonon spectrum and the electron-phonon matrix element, the electron-phonon coupling ?’s are similar for the three elements. Hence, the Debye temperature, which is the prefactor of the McMillan equation, dominates in determining the superconducting critical temperatures.

K. J. Chang and Marvin L. Cohen

1986-10-01T23:59:59.000Z

153

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

SciTech Connect

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

154

Journal of Luminescence 9495 (2001) 747750 Phonon spectrum in a nanoparticle mechanically  

E-Print Network (OSTI)

Journal of Luminescence 94­95 (2001) 747­750 Phonon spectrum in a nanoparticle mechanically coupled nanoparticle that is in weak mechanical contact with a semi-infinite substrate. The work is motivated by a recent experiment by Yang et al., where the low-energy phonon density-of-states of Y2O3 nanoparticles

Geller, Michael R.

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

Heat transport properties of clean spin ladders coupled to phonons: Umklapp scattering and drag  

E-Print Network (OSTI)

Heat transport properties of clean spin ladders coupled to phonons: Umklapp scattering and drag E; published 17 December 2007 We study the low-temperature heat transport in clean two-leg spin-ladder compounds coupled to three- dimensional phonons. We argue that the very large heat conductivities observed

Mehta, Pankaj

157

A novel neutron spin echo technique for measuring phonon linewidths using magnetic Wollaston prisms  

Science Journals Connector (OSTI)

A neutron spin echo spectrometer based on neutron magnetic Wollaston prisms is introduced to measure the linewidth of dispersive phonon excitations over the entire Brillouin zone with ?eV resolution. By tuning the instrument electromagnetically, the linewidths of phonon excitations with high energy and large group velocity can be measured.

Li, F.

2014-10-17T23:59:59.000Z

158

Exciton-phonon coupled states in CuCl quantum cubes  

Science Journals Connector (OSTI)

The size dependence of excitonic states and vibrational modes in CuCl cubic quantum dots embedded in NaCl crystals was studied by means of site-selective persistent spectral hole burning spectroscopy. It is shown that the interaction of the longitudinal optical (LO) phonon with the exciton results in the formation of coupled exciton-phonon modes when the energy of the LO phonon approaches the energy spacings between the ground and excited states of the exciton. The energy anticrossings of the LO phonon modes with two higher optically allowed excited states of the exciton in CuCl QD’s were clearly observed at confinement energies of about 10 and 6 meV, respectively. In addition, the linewidth of the LO phonon sideband in CuCl QD’s in NaCl crystals was found to increase abruptly from 0.3 meV to about 1.2 meV at a confinement energy of about 23 meV, which appears to result from the exciton-phonon mixing of the LO phonon mode with the first excited state of the exciton. The experimental results are qualitatively understood by the LO phonon renormalization theory.

Jialong Zhao; Selvakumar V. Nair; Yasuaki Masumoto

2000-12-29T23:59:59.000Z

159

Spectral diffusion of molecular electronic transitions in amorphous solids: Weak and strong two-level-system phonon coupling  

SciTech Connect

The two-level-system (TLS) model of glasses is used with nonphenomenological TLS distribution functions [R. Jankowiak [ital et] [ital al]., J. Phys. Chem. 90, 3896 (1986)] to account for the time-dependent spectral-diffusion data for cresyl violet and zinc porphin in ethanol glasses at low temperatures [K. A. Littau and M. D. Fayer, Chem. Phys. Lett. 176, 551 (1991); H. C. Meijers and D. A. Wiersma, Phys. Rev. Lett. 68, 381 (1992)]. The two distributions of faster and slower TLS relaxation rates required to fit the data are characterized for both weak and strong TLS-phonon coupling. Comparison of the values obtained for the TLS parameters with those determined earlier for specific heat, thermal conductivity, pure dephasing, and spontaneous filling of nonphotochemical holes establishes that the faster and slower distributions are associated with intrinsic and extrinsic TLS. The pronounced effects of strong coupling on the TLS relaxation-rate distributions are discussed.

Jankowiak, R.; Small, G.J. (Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States))

1993-06-01T23:59:59.000Z

160

Phonon contribution to the shear viscosity of a superfluid Fermi gas in the unitarity limit  

SciTech Connect

We present a detailed analysis of the contribution of small-angle Nambu–Goldstone boson (phonon) collisions to the shear viscosity, ?, in a superfluid atomic Fermi gas close to the unitarity limit. We show that the experimental values of the shear viscosity coefficient to entropy ratio, ?/s, obtained at the lowest reached temperature can be reproduced assuming that phonons give the leading contribution to ?. The phonon contribution is evaluated considering 1?2 processes and taking into account the finite size of the experimental system. In particular, for very low temperatures, T?0.1T{sub F}, we find that phonons are ballistic and the contribution of phonons to the shear viscosity is determined by the processes that take place at the interface between the superfluid and the normal phase. This result is independent of the detailed form of the phonon dispersion law and leads to two testable predictions: the shear viscosity should correlate with the size of the optical trap and it should decrease with decreasing temperature. For higher temperatures the detailed form of the phonon dispersion law becomes relevant and, within our model, we find that the experimental data for ?/s can be reproduced assuming that phonons have an anomalous dispersion law. -- Highlights: •We study the contribution of phonons to shear viscosity of a cold Fermi gas at unitary. •The shear viscosity to entropy ratio (?/s) is reproduced for T?0.1T{sub F} assuming an anomalous dispersion law for phonons.

Mannarelli, Massimo [I.N.F.N., Laboratori Nazionali del Gran Sasso, Assergi (AQ) (Italy)] [I.N.F.N., Laboratori Nazionali del Gran Sasso, Assergi (AQ) (Italy); Manuel, Cristina [Instituto de Ciencias del Espacio (IEEC/CSIC), Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain)] [Instituto de Ciencias del Espacio (IEEC/CSIC), Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain); Tolos, Laura, E-mail: tolos@ice.csic.es [Instituto de Ciencias del Espacio (IEEC/CSIC), Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain) [Instituto de Ciencias del Espacio (IEEC/CSIC), Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain); Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany)

2013-09-15T23:59:59.000Z

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.


161

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

162

Thermal conductance of metal-metal interfaces  

Science Journals Connector (OSTI)

The thermal conductance of interfaces between Al and Cu is measured in the temperature range 78thermal conductance of the as-deposited Al-Cu interface is 4GWm?2K?1 at room temperature, an order-of-magnitude larger than the phonon-mediated thermal conductance of typical metal-dielectric interfaces. The magnitude and the linear temperature dependence of the conductance are described well by a diffuse-mismatch model for electron transport at interfaces.

Bryan C. Gundrum; David G. Cahill; Robert S. Averback

2005-12-30T23:59:59.000Z

163

Single-phonon and multi-phonon excitations of the $?$ vibration in rotating odd-$A$ nuclei  

E-Print Network (OSTI)

Multi-phonon excitations in atomic nuclei were observed very rarely although collective motions in quantum many-body systems are described as bosonic excitations. In particular, the first two-phonon $\\gamma$ vibrational ($2\\gamma$) excitation in odd-$A$ nuclei was reported in 2006 and only a few have been known. Quite recently, conspicuously enhanced $B(E2)$s feeding $2\\gamma$ states were observed in $^{105}$Nb and conjectured that their parent states are candidates of $3\\gamma$ states. In the present work, the model space is enlarged from the present author's previous calculation for $^{103}$Nb. The purpose is twofold: One is to see how the description of $2\\gamma$ states is improved, and the other is to examine the existence of collective $3\\gamma$ states, and when they exist, study their collectivity through calculating interband $B(E2)$s. The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. Interband $B(E2)$s are calculated by adopting the method of the generalized intensity relation. The present calculation reproduces the observed spectra of $0\\gamma$ - $2\\gamma$ states well and gives collective $3\\gamma$ states with enhanced $B(E2)$s to $2\\gamma$ states in $^{103}$Nb and $^{105}$Nb. The most collective $3\\gamma$ state with the highest $K$ at zero rotation is thought to be the main component of the observed band.

Masayuki Matsuzaki

2014-06-13T23:59:59.000Z

164

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

SciTech Connect

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

165

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

166

Solid-State Lighting Patents Resulting from DOE-Funded Projects  

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

Electroluminescent Material and Photoluminescent Materials NP * Lighting System with Heat Distribution Face Plate NP, PCT * Lighting System with Thermal Management System NP,...

167

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.

168

Piezoelectric surface acoustical phonon amplification in graphene on a GaAs substrate  

SciTech Connect

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

169

Phonon Contribution to the Free Energy of Interacting Adatom Pairs  

Science Journals Connector (OSTI)

The free energy ?F due to the interaction through the crystal phonon field of two identical atoms adsorbed on a (100) surface of a simple cubic monatomic lattice is studied within the framework of the Montroll-Potts model. The zero-point energy of interaction, ?E0, is found analytically in the limit of large separation distances, and numerical results are presented for small separation distances. The leading temperature-dependent terms in the expansion of ?F are given in closed form in both the low- and high-temperature limits. The results are given as a function of the mass and separation distance of the adsorbed atoms and as a function of the force constant binding the adsorbed atoms to the surface. For all values of the model parameters, it is found that the free energy decreases with the separation distance. Thus, two adatoms on a surface are attracted toward each other.

S. L. Cunningham, L. Dobrzynski, and A. A. Maradudin

1973-05-15T23:59:59.000Z

170

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

SciTech Connect

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

171

Light Portal  

Science Journals Connector (OSTI)

The Light Portal was designed to organize and mark the pedestrian paths that circumnavigate the rectangle of the...

2006-01-01T23:59:59.000Z

172

A step closer to visualizing the electron___phonon interplay  

SciTech Connect

The origin of the very high superconducting transition temperature (Tc) in ceramic copper oxide superconductors is one of the greatest mysteries in modern physics. In the superconducting state, electrons form pairs (known as Cooper pairs) and condense into the superfluid state to conduct electric current with zero resistance. For conventional superconductors, it is well established that the 2 electrons in a Cooper pair are 'bonded' by lattice vibrations (phonons), whereas in high-Tc superconductors, the 'glue' for the Cooper pairs is still under intense discussion. Although the high transition temperature and the unconventional pairing symmetry (d-wave symmetry) have led many researchers to believe that the pairing mechanism results from electron-electron interaction, increasing evidence shows that electron-phonon coupling also significantly influences the low-energy electronic structures and hence may also play an important role in high-Tc superconductivity. In a recent issue of PNAS, Carbone et al. use ultrafast electron diffraction, a recently developed experimental technique, to attack this problem from a new angle, the dynamics of the electronic relaxation process involving phonons. Their results provide fresh evidence for the strong interplay between electronic and atomic degrees of freedom in high-Tc superconductivity. In general, ultrafast spectroscopy makes use of the pump-probe method to study the dynamic process in material. In such experiments, one first shoots an ultrafast (typically 10-100 fs) 'pumping' pulse at the sample to drive its electronic system out of the equilibrium state. Then after a brief time delay ({Delta}t) of typically tens of femtoseconds to tens of picoseconds, a 'probing' pulse of either photons or electrons is sent in to probe the sample's transient state. By varying {Delta}t, one can study the process by which the system relaxes back to the equilibrium state, thus acquiring the related dynamic information. This pump-probe experiment is reminiscent of the standard method used by bell makers for hundreds of years to judge the quality of their products (hitting a bell then listening to how the sound would fade away), albeit the relevant time scale here is way beyond tens of femtoseconds. Traditionally, ultrafast spectroscopy was carried out to study gas-phase reactions, but it has also been applied to study condensed phase systems since the development of reliable solid-state ultrafast lasers approximately a decade ago. In addition, the ability to control pulse width, wavelength, and amplification of the output of Ti:Sapphire lasers has further increased the capability of this experimental method. During the past decade, many ultrafast pump-probe experiments have been carried out in various fields by using different probing methods, such as photo-resistivity, fluorescence yield, and photoemission, and they have revealed much new information complementary to the equilibrium spectroscopy methods used before. Carbone et al. used the photon-pump, electron (diffraction)-probe method. The pumping photon pulse first drives the electrons in the sample into an oscillating mode along its polarization direction. Then during the delay time, these excited electrons can transfer excess energy to the adjacent nuclei and cause crystal lattice vibration on their way back to the equilibrium state. An ultrashort electron pulse is shot at the sample at various time delays {Delta}t and the diffraction pattern is collected. Because the electron diffraction pattern is directly related to the crystal lattice structure and its motion, this technique provides a natural way to study the electron-phonon coupling problem. Furthermore, by adjusting the pump pulse's relative polarization with respect to the Cu-O bond direction, Carbone et al. were able to acquire the electron-phonon coupling strength along different directions. Focusing on the lattice dynamic along the c axis, Carbone et al. found that the c-axis phonons in the optimally-doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (Bi2212) are coupled to the electrons

Chen, Y.L.; Lee, W.S.; Shen, Z.X.; /Stanford U., Appl. Phys. Dept. /Stanford U., Phys. Dept. /SLAC, PULSE

2011-01-04T23:59:59.000Z

173

Light's twist  

Science Journals Connector (OSTI)

...equal to the optical power divided by the speed of light, and hence go unnoticed in our everyday lives...approaching object equal to the power in the light beam (P) divided by the speed of light. The movement of the approaching object does...

2014-01-01T23:59:59.000Z

174

Light Properties Light travels at the speed of light `c'  

E-Print Network (OSTI)

LIGHT!! #12;Light Properties Light travels at the speed of light `c' C = 3 x 108 m/s Or 190.nasa.gov #12;The speed of light The speed of light `c' is equal to the frequency ` times the wavelength,000 miles/second!! Light could travel around the world about 8 times in one second #12;What is light?? Light

Mojzsis, Stephen J.

175

Lighting Systems  

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

Purple LED lamp Purple LED lamp Lighting Systems Lighting research is aimed at improving the energy efficiency of lighting systems in buildings and homes across the nation. The goal is to reduce lighting energy consumption by 50% over twenty years by improving the efficiency of light sources, and controlling and delivering illumination so that it is available, where and when needed, and at the required intensity. Research falls into four main areas: Sources and Ballasts, Light Distribution Systems, Controls and Communications, and Human Factors. Contacts Francis Rubinstein FMRubinstein@lbl.gov (510) 486-4096 Links Lighting Research Group Batteries and Fuel Cells Buildings Energy Efficiency Applications Commercial Buildings Cool Roofs and Heat Islands Demand Response Energy Efficiency Program and Market Trends

176

Isotope effect of the phonons mean free path in graphene by micro-Raman measurement  

Science Journals Connector (OSTI)

The isotope labeled graphene was synthesized in the concentration of 13C carbon atom in 1%, 25%, 50%, 75% and 99%. The isotope effect on the phonon behavior in graphene was investigated based on the micro-Raman a...

CanKun Zhang; QiongYu Li; Bo Tian…

2014-10-01T23:59:59.000Z

177

THE DEPLOYMENT OF ZIP NON-EQUILIBRIUM PHONON DETECTORS IN CDMS II  

E-Print Network (OSTI)

operating these Si and Ge Z-sensitive Ionization and Phonon (ZIP) detectors at the Stanford Underground Facility are reported. 1 Surface electron events The Cryogenic Dark Matter Search (CDMS) 1 utilizes

California at Berkeley, University of

178

Terahertz quantum cascade lasers based on resonant phonon scattering for depopulation  

Science Journals Connector (OSTI)

...Michael Pepper Terahertz quantum cascade lasers based on resonant phonon...development of terahertz (THz) quantum cascade lasers (QCLs), in which the depopulation...intersubband|quantum wells|quantum cascade lasers|longitudinal optical...

2004-01-01T23:59:59.000Z

179

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

NLE Websites -- All DOE Office Websites (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...

180

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

SciTech Connect

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

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

Probing Confined Phonon Modes in Individual CdSe Nanoplatelets using Surface-Enhanced Raman Scattering  

E-Print Network (OSTI)

range of disciplines ranging from solar cells and single-photon sources to molecular tagging and sensing. As well as exciton confinement, the phonons inside these ultra-thin semiconductor structures also feel confinement effects. Here we demonstrate... -level precision. This is of great interest to a broad range of nanofabrication technologies where accurate film thickness control is required. This also opens the potential to excite and track local phonon interactions within and in neighbouring nanostructures...

Sigle, Daniel O; Hugall, James T; Ithurria, Sandrine; Dubertret, Benoit; Baumberg, Jeremy J

2014-01-01T23:59:59.000Z

182

Parity conservation in electron-phonon scattering in zigzag graphene nanoribbon  

SciTech Connect

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

183

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

SciTech Connect

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

184

Exciton–phonon complexes and optical properties in CdSe nanocrystals  

Science Journals Connector (OSTI)

A method to calculate the quantum states of exciton–phonon complexes in semiconductor nanocrystals is presented. The exciton–phonon complexes are built from a basis set made of products of phonon states and electron–hole pairs, which are coupled through the electron–phonon Fröhlich interaction, and the electron–hole Coulomb and exchange interactions. In CdSe nanocrystals, the conduction band electrons are described by the effective mass equation, while the holes are represented by the spherical 4 ? 4 Baldereschi–Lipari Hamiltonian. It is shown that a flexible and complete electron–hole basis, not limited to the 1s–1S3/2 octet, is essential to obtain converged eigenvalues and the correct polaron shift to the exciton energy. A study of the spectral properties is presented; in particular, the spectral region which involves the lowest exciton–phonon complex eigenstates is analysed in details. Specifically, the non-adiabatic nature of the exciton–phonon dynamics in the nanocrystals examined is clearly shown by the vibron eigenstates that were obtained.

E Menéndez-Proupin; N G Cabo-Bizet; C Trallero-Giner

2006-01-01T23:59:59.000Z

185

Gold nanoparticle assemblies: Interplay between thermal effects and optical response  

E-Print Network (OSTI)

1 Gold nanoparticle assemblies: Interplay between thermal effects and optical response Bruno nanoparticle assemblies depends on many parameters regarding both material morphology and light excitation-embedded gold nanoparticles can result in the generation of thermal excitations through different energy

Boyer, Edmond

186

Study on generating of thermal neutron scattering cross sections for LiH  

SciTech Connect

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

187

Lighting Renovations  

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

188

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

189

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.

190

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

191

Electric thermal storage demonstration program  

SciTech Connect

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

192

Electric thermal storage demonstration program  

SciTech Connect

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

193

Electric thermal storage demonstration program  

SciTech Connect

In early 1989, MMWEC, a joint action agency comprised of 30 municipal light departments in Massachusetts and on affiliate in Rhode Island, responded to a DOE 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. This report discusses the demonstration of ETS equipment at four member light departments.

Not Available

1992-01-01T23:59:59.000Z

194

Electric thermal storage demonstration program  

SciTech Connect

In early 1989, MMWEC, a joint action agency comprised of 30 municipal light departments in Massachusetts and on affiliate in Rhode Island, responded to a DOE 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. This report discusses the demonstration of ETS equipment at four member light departments.

Not Available

1992-02-01T23:59:59.000Z

195

Northern Lights  

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

Northern Lights Northern Lights Nature Bulletin No. 178-A February 6, 1965 Forest Preserve District of Cook County Seymour Simon, President Roland F. Eisenbeis, Supt. of Conservation NORTHERN LIGHTS To a person seeing the Aurora Borealis or "northern lights" for the first time, it is an uncanny awe-inspiring spectacle. Sometimes it begins as a glow of red on the northern horizon, ominously suggesting a great fire, gradually changing to a curtain of violet-white, or greenish-yellow light extending from east to west. Some times this may be transformed to appear as fold upon fold of luminous draperies that march majestically across the sky; sometimes as a vast multitude of gigantic flaming swords furiously slashing at the heavens; sometimes as a flowing crown with long undulating colored streamers fanning downward and outward.

196

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

SciTech Connect

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

2011-05-01T23:59:59.000Z

197

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

198

Low temperature thermal transport in partially perforated silicon nitride membranes.  

SciTech Connect

The thermal transport in partially trenched silicon nitride membranes has been studied in the temperature range from 0.3 to 0.6 K, with the transition edge sensor (TES), the sole source of membrane heating. The test configuration consisted of Mo/Au TESs lithographically defined on silicon nitride membranes 1 {micro}m thick and 6 mm{sup 2} in size. Trenches with variable depth were incorporated between the TES and the silicon frame in order to manage the thermal transport. It was shown that sharp features in the membrane surface, such as trenches, significantly impede the modes of phonon transport. A nonlinear dependence of thermal resistance on trench depth was observed. Partial perforation of silicon nitride membranes to control thermal transport could be useful in fabricating mechanically robust detector devices.

Yefremenko, V.; Wang, G.; Novosad, V.; Datesman, A.; Pearson, J.; Divan, R.; Chang, C. L.; Downes, T. P.; Mcmahon, J. J.; Bleem, L. E.; Crites, A. T.; Meyer, S. S.; Carlstrom, J. E.; Univ. of Chicago

2009-05-04T23:59:59.000Z

199

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

200

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

SciTech Connect

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

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

Solid-State Lighting: LED Lighting Facts  

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

Market-Based Programs Printable Version Share this resource Send a link to Solid-State Lighting: LED Lighting Facts to someone by E-mail Share Solid-State Lighting: LED Lighting Facts on Facebook Tweet about Solid-State Lighting: LED Lighting Facts on Twitter Bookmark Solid-State Lighting: LED Lighting Facts on Google Bookmark Solid-State Lighting: LED Lighting Facts on Delicious Rank Solid-State Lighting: LED Lighting Facts on Digg Find More places to share Solid-State Lighting: LED Lighting Facts on AddThis.com... LED Lighting Facts CALiPER Program Standards Development Technical Information Network Gateway Demonstrations Municipal Consortium Design Competitions LED Lighting Facts LED lighting facts - A Program of the U.S. DOE DOE's LED Lighting Facts® program showcases LED products for general

202

Thermal treatment  

Science Journals Connector (OSTI)

Thermal treatment can be regarded as either a pre-treatment of waste prior to final disposal, or as a means of valorising waste by recovering energy. It includes both the burning of mixed MSW in municipal inciner...

Dr. P. White; Dr. M. Franke; P. Hindle

1995-01-01T23:59:59.000Z

203

Thermal Processes  

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

Some thermal processes use the energy in various resources, such as natural gas, coal, or biomass, to release hydrogen, which is part of their molecular structure. In other processes, heat, in...

204

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

SciTech Connect

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

205

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

206

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

207

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

208

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

SciTech Connect

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

209

Dispersion relations of surface phonons in LiF(001) and NaF(001)  

Science Journals Connector (OSTI)

Recent atom-scattering experimental data have stimulated a new investigation on the surface phonons of some alkali halides. In the framework of Green's-function method applied to breathing-shell model dynamics we have calculated the dispersion curves and a few K-selected densities of states of surface phonons for the (001) surface of NaF and LiF at room temperature. Particular attention is paid to the change in ion polarizabilities occurring at the surface and its effect on the Rayleigh wave frequencies at the zone boundary.

G. Benedek; G. P. Brivio; L. Miglio; V. R. Velasco

1982-07-15T23:59:59.000Z

210

Pressure increase of the electron-phonon interaction in superconducting hexagonal silicon  

Science Journals Connector (OSTI)

Using an ab initio pseudopotential approach, the pressure dependence of the electron-phonon interaction parameter ? and the phonon frequencies for metallic hexagonal phases of silicon is calculated. With changing pressure ? is found to go first through a minimum and then reach its maximum value near the phase transition from simple hexagonal (sh) to hexagonal close packed (hcp). At this point the superconducting transition temperature Tc is expected to be above 10 K. In the hcp phase Si is predicted to be superconducting with Tc in the same range as in the sh phase.

Michel M. Dacorogna; K. J. Chang; Marvin L. Cohen

1985-08-01T23:59:59.000Z

211

Linear-response calculation of electron-phonon coupling parameters Department of Physics, Georgetown University, Washington, D.C. 20057-0995  

E-Print Network (OSTI)

Linear-response calculation of electron-phonon coupling parameters Amy Y. Liu Department of Physics, California 94551-0969 Received 19 December 1995 An ab initio method for calculating electron-phonon coupling for the calculation of lattice dynamics. Results for the mass enhancement parameter and the electron-phonon spectral

Liu, Amy Y.

212

Light's twist  

Science Journals Connector (OSTI)

...Glasgow G12 8QQ, UK An invited Perspective to mark the election of Miles Padgett to the fellowship of the Royal Society in 2014. That...energy and momentum flow within light beams can twist to form vortices such as eddies in a stream. These...

2014-01-01T23:59:59.000Z

213

Photo-, Thermally, and pH-Responsive Microgels  

Science Journals Connector (OSTI)

Photo-, Thermally, and pH-Responsive Microgels† ... Microgels with photo-, thermally, and pH-responsive properties in aqueous suspension have been synthesized and characterized using dynamic light scattering and UV?visible spectroscopy. ... This synthesis has the significant advantage of forming monodisperse particles with thermally, photo-, and pH-responsive properties. ...

Antonio Garcia; Manuel Marquez; Tong Cai; Rohit Rosario; Zhibing Hu; Devens Gust; Mark Hayes; Sean A. Vail; Choong-Do Park

2006-10-19T23:59:59.000Z

214

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

215

Inelastic Thermal Neutron Scattering Cross Sections for Reactor-grade Graphite  

Science Journals Connector (OSTI)

Abstract Current calculations of the inelastic thermal neutron scattering cross sections of graphite are based on representing the material using ideal single crystal models. However, the density of reactor-grade graphite is usually in the range of 1.5 g/cm3 to approximately 1.8 g/cm3, while ideal graphite is characterized by a density of nearly 2.25 g/cm3. This difference in density is manifested as a significant fraction of porosity in the structure of reactor-grade graphite. To account for the porosity effect on the cross sections, classical molecular dynamics (MD) techniques were employed to simulate graphite structures with porosity concentrations of 10% and 30%, which are taken to be representative of reactor-grade graphite. The phonon density of states for the porous systems were generated as the power spectrum of the MD velocity autocorrelation functions. The analysis revealed that for porous graphite the phonon density of states exhibit a rise in the lower frequency region that is relevant to neutron thermalization. Using the generated phonon density of states, the inelastic thermal neutron scattering cross sections were calculated using the NJOY code system. While marked discrepancies exist between measurements and calculations based on ideal graphite models, favorable agreement is found between the calculations based on the porous graphite models and measured data.

A.I. Hawari; V.H. Gillete

2014-01-01T23:59:59.000Z

216

Texas Electric Lighting Report  

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

electric lighting electric lighting The SNAP House's lighting design aims for elegant simplicity in concept, use, and maintenance. Throughout the house, soft, ambient light is juxtaposed with bright, direct task lighting. All ambient and most task lighting is integrated directly into the architectural design of the house. An accent light wall between the bedroom and bathroom provides a glowing light for nighttime navigation.

217

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

218

Optical phonons and the soft mode in 2H-NbSe2  

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

219

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

220

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

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

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

222

Superconducting phonon structure in the transition from tunneling to contact regime  

Science Journals Connector (OSTI)

We study the variation of the phonon structure in the conductance curves of superconducting variable-barrier junctions formed using a scanning tunneling microscope. The observed vanishing of this structure as the tunneling barrier decreases is explained as a result of the mixing of electronic states in the Andreev reflection process, whose importance increases as the tunneling barrier decreases.

J. G. Rodrigo; N. Agraït; C. Sirvent; S. Vieira

1994-09-01T23:59:59.000Z

223

Terahertz Time Domain Spectroscopy of Phonon-Depopulation Based Quantum Cascade Lasers  

SciTech Connect

A 3.1 THz phonon depopulation-based quantum-cascade-laser is investigated using terahertz time domain spectroscopy. A gain of 25 cm{sup -1} and absorption features due to the lower laser level being populated from a parasitic electronic channel are highlighted.

Rungsawang, R.; Dhillon, S. S.; Jukam, N.; Oustinov, D.; Madeo, J.; Tignon, J. [Laboratoire Pierre Aigrain, Ecole Normale Superieure, UMR8551 CNRS, UPMC Univ. Paris 6, F-75005 Paris (France); Colombelli, R. [Institut d'Electronique Fondamentale, Universite Paris Sud, UMR8622 CNRS, 91405 Orsay (France); Dean, P.; Salih, M.; Khanna, S. P.; Linfield, E.; Davies, A. G. [School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT (United Kingdom)

2011-12-23T23:59:59.000Z

224

Al composition dependency of interface phonon in the wurtzite quantum cascade laser  

Science Journals Connector (OSTI)

The interface (IF) phonons of the wurtzite quantum cascade lasers (QCL) are investigated using the transfer-...0.2Ga0.8N/GaN and Al0.15Ga0.85N/GaN QCLs, and two IF modes can be changed into other modes if their w...

Gui-chu Chen ???; Guang-han Fan ???

2010-05-01T23:59:59.000Z

225

Dielectric tensor and plasmon-phonon modes in semiconductors with anisotropic conduction valleys  

Science Journals Connector (OSTI)

The wavevector- and frequency-dependent self-consistent field approximation dielectric tensor of an n-type semiconductor with anisotropic, multi-valley and parabolic conduction band is derived taking into account the optical phonon contribution. The high-frequency and long-wavelength form of this tensor, calculated in the degenerate plasma limit, is used for the normal mode analysis. The dispersion equation for the plasmon-phonon modes with long wavelength is found to have an isotropic-like form, epsilon 1(q, omega )=0, except for the case of the lower-frequency mode in the strongly anisotropic, very dense conduction band plasma; epsilon 1(q, omega ) is the appropriate wave-vector-direction-dependent longitudinal dielectric function. The plasmon-phonon modes dispersion relation is established up to terms quadratic in the wavevector and the dependence of the frequencies on the propagation direction is discussed. The dispersibility of the lower-frequency mode has a maximum close to the point where the phonon frequency omega LO is equal to the plasma frequency omega p. Special attention is paid to lead salts and numerical estimates are made for PbTe.

S Goettig

1981-01-01T23:59:59.000Z

226

Phonons in a nanoparticle mechanically coupled to a substrate Kelly R. Patton and Michael R. Geller  

E-Print Network (OSTI)

Phonons in a nanoparticle mechanically coupled to a substrate Kelly R. Patton and Michael R. Geller investigate the modification of the vibrational modes of a spherical insulating nanoparticle caused by a weak oscillators, and the coupling to this reservoir shifts and broadens the nanoparticle's modes. The vibrational

Geller, Michael R.

227

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

228

Exciton coherence-size and phonon-mediated optical nonlinearities in restricted geometries  

E-Print Network (OSTI)

Exciton coherence-size and phonon-mediated optical nonlinearities in restricted geometries Oleg(x'~`) of a one- dimensionalmolecular crystal or a polymer. We show that the coherence-lengthis determined, the optical responseof molecular clusters, monolayers, and crystals is related to the dynamics of delocalized~coherent

Mukamel, Shaul

229

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

230

Resonant impurity scattering and electron-phonon scattering in the electrical resistivity of Cr thin films  

E-Print Network (OSTI)

Resonant impurity scattering and electron-phonon scattering in the electrical resistivity of Cr The resistivity as a function of temperature from 0.6 to 300 K for epitaxial and polycrystalline Cr thin films residual resistivity up to 400 cm and a minimum at low temperatures below 100 K . This is strong

Hellman, Frances

231

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

SciTech Connect

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

232

Hot-phonon effects in femtosecond luminescence spectra of electron-hole plasmas in CdS  

Science Journals Connector (OSTI)

The carrier intraband relaxation in CdS is studied with femtosecond time resolution using the luminescence up-conversion technique. The cooling dynamics of high-density carriers clearly show the nonequilibrium build-up of high populations of certain modes for both longitudinal optical and acoustic phonons. The acoustic-mode disturbances develop on the subpicosecond time scale and are observed as a transient reduction of the carrier energy-loss rate through the retardation of the optical-phonon decay (the effect of the ‘‘acoustic-phonon bottleneck’’).

V. Klimov; P. Haring Bolivar; H. Kurz

1995-08-15T23:59:59.000Z

233

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

234

Lighting Test Facilities  

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

Custom Projects Lighting Test Facilities SSL Guidelines Industrial Federal Agriculture LED Street and Area Lighting Field Test of Exterior LED Down Lights Abstract Outdoor...

235

Light Water Reactor Sustainability  

NLE Websites -- All DOE Office Websites (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...

236

High-frequency response and acoustic phonon contribution of the linear electro-optic effect in DAST  

Science Journals Connector (OSTI)

We present a simple method to measure the contribution from acoustic phonons to the linear electro-optic effect. A step voltage with a short rise time (600 ps) is applied to the...

Spreiter, R; Bosshard, Ch; Pan, F; Günter, P

1997-01-01T23:59:59.000Z

237

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

SciTech Connect

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

238

Engineering phonon-photon interactions with a driven trapped ion in a cavity  

Science Journals Connector (OSTI)

We show how to generate quadratic and biquadratic phonon-photon interactions through a driven three-level ion inside a cavity. With such a system it is possible to squeeze the cavity-field state, the ion motional state, or even the entangled phonon-photon state. We present a detailed analysis of the cavity-field squeezing process, distinguishing three different regimes of this amplification mechanism: the subcritical, critical, and supercritical regimes, which depend, apart from the coupling parameters, on the excitation of the vibrational state. As an application of the engineered Hamiltonians, we show how to implement a Fock-state filter for the vibrational mode. Different aspects of the technique of adiabatic elimination emerge in this analysis.

R. L. Rodrigues; M. H. Y. Moussa; C. J. Villas-Bôas

2006-12-12T23:59:59.000Z

239

Engineering phonon-photon interactions with a driven trapped ion in a cavity  

E-Print Network (OSTI)

We show how to generate quadratic and bi-quadratic phonon-photon interactions through a driven three-level ion inside a cavity. With such a system it is possible to squeeze the cavity-field state, the ion motional state or even the entangled phonon-photon state. We present a detailed analysis of the cavity-field squeezing process, distinguishing three different regimes of this amplification mechanism: the subcritical, critical, and supercritical regimes, which depend, apart from the coupling parameters, on the excitation of the vibrational state. As an application of the engineered Hamiltonians, we show how to implement a Fock-state filter for the vibrational mode. New aspects of the technique of adiabatic elimination emerge in this analysis.

R. L. Rodrigues; M. H. Y. Moussa; C. J. Villas-Boas

2006-09-26T23:59:59.000Z

240

The electron-phonon interaction from fundamental local gauge symmetries in solids  

E-Print Network (OSTI)

The elastic properties of solids are described in close analogy with General Relativity, by locally gauging the translational group of space-time. Electron interactions with the crystal lattice are thus generated by enforcing full gauge invariance, with the introduction of a gauge field. Elementary excitations are associated with the local gauge, contrasting to the usual interpretation as being Goldstone bosons emerging from global symmetry breaking. In the linear limit of the theory, the gauge field displays elastic waves, that we identify with acoustic phonons, when the field is quantized. Coupling with the electronic part of the system yields the standard electron-phonon interaction. If spin-orbit effects are included, unusual couplings emerge between the strain field and the electronic spin current, leading to novel physics that may be relevant for spintronic applications.

C. A. Dartora; G. G. Cabrera

2013-07-12T23:59:59.000Z

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

Phonon-drag thermopower in anisotropic AlAs quantum wells  

SciTech Connect

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

242

Light Bodies: Exploring Interactions with Responsive Lights  

E-Print Network (OSTI)

reinterpretation of street lighting. Before fixed infrastructure illuminated cities at night, people carried Urban street lighting today is a networked, fixed infrastructure that relies on the electrical grid. WeLight Bodies: Exploring Interactions with Responsive Lights Susanne Seitinger MIT Media Laboratory

Hunt, Galen

243

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

244

Lighting | Department of Energy  

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

Lighting Lighting Lighting When you're shopping for lightbulbs, compare lumens and use the Lighting Facts label to be sure you're getting the amount of light, or level of brightness, you want. You can save money and energy while lighting your home and still maintaining good light quantity and quality. Consider energy-efficient lighting options to use the same amount of light for less money. Learn strategies for comparing and buying lighting products and using them efficiently. Featured Lighting Choices to Save You Money Light your home for less money while using the same amount of light. How Energy-Efficient Light Bulbs Compare with Traditional Incandescents Energy-efficient light bulbs are available today and could save you about $50 per year in energy costs when you replace 15 traditional incandescent bulbs in your home.

245

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

246

Effect of boundary scattering on the thermal conductivity of TiNiSn-based half-Heusler alloys  

Science Journals Connector (OSTI)

TiNiSn-based half-Heusler alloys have been of significant interest for their potential as thermoelectric materials. They exhibit promising electronic transport properties as revealed through high Seebeck coefficient and moderate electrical resistivity values. The chief disadvantage of these materials is a comparatively high lattice thermal conductivity. Attempts to “tune” the lattice thermal conductivity (?L) in these materials have led to the comparison and analysis of the thermal conductivity of two series of Ti- and Zr-based half-Heusler alloys. In the first series, Ti1?yZryNiSn0.95Sb0.05, a significant reduction in ?L is observed, with the substitution of large concentrations of Zr (y?25%) at Ti site, which is most likely due to mass fluctuation scattering. In the second series, TiNiSn1?xSbx, a nonsystematic increase in ?L is observed, with minute amounts of Sb doping (x?5%) at the Sn site. Extensive microstructural analysis in a TiNiSn1?xSbx series reveals a correlation between ?L and the average grain diameter in these materials, which is in good agreement with theoretical predictions related to phonon boundary scattering. In addition, a comparison of the calculated phonon mean free path in each of the series of compounds shows some insight into the two different phonon scattering mechanisms.

S. Bhattacharya; M. J. Skove; M. Russell; T. M. Tritt; Y. Xia; V. Ponnambalam; S. J. Poon; N. Thadhani

2008-05-30T23:59:59.000Z

247

Architectural Lighting Analysis in Virtual Lighting Laboratory  

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

Architectural Lighting Analysis in Virtual Lighting Laboratory Architectural Lighting Analysis in Virtual Lighting Laboratory Speaker(s): Mehlika Inanici Date: July 7, 2003 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Satkartar K. Kinney Virtual Lighting Laboratory is a Radiance-based lighting analysis tool and methodology that proposes transformations in the utilization of computer visualization in lighting analysis and design decision-making. It is a computer environment, where the user has been provided with matrices of illuminance and luminance values extracted from high dynamic range images. The principal idea is to provide the laboratory to the designer and researcher to explore various lighting analysis techniques instead of imposing limited number of predetermined metrics. In addition, it introduces an analysis approach for temporal and spatial lighting

248

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

249

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

250

Monte Carlo simulations of electron thermalization in alkali iodide and alkaline-earth fluoride scintillators  

SciTech Connect

A Monte Carlo model of electron thermalization in inorganic scintillators, which was developed and applied to CsI in a previous publication [Wang et al., J. Appl. Phys. 110, 064903 (2011)], is extended to another material of the alkali halide class, NaI, and to two materials from the alkaline-earth halide class, CaF{sub 2} and BaF{sub 2}. This model includes electron scattering with both longitudinal optical (LO) and acoustic phonons as well as the effects of internal electric fields. For the four pure materials, a significant fraction of the electrons recombine with self-trapped holes and the thermalization distance distributions of the electrons that do not recombine peak between approximately 25 and 50 nm and extend up to a few hundreds of nanometers. The thermalization time distributions of CaF{sub 2}, BaF{sub 2}, NaI, and CsI extend to approximately 0.5, 1, 2, and 7 ps, respectively. The simulations show that the LO phonon energy is a key factor that affects the electron thermalization process. Indeed, the higher the LO phonon energy is, the shorter the thermalization time and distance are. The thermalization time and distance distributions show no dependence on the incident {gamma}-ray energy. The four materials also show different extents of electron-hole pair recombination due mostly to differences in their electron mean free paths (MFPs), LO phonon energies, initial densities of electron-hole pairs, and static dielectric constants. The effect of thallium doping is also investigated for CsI and NaI as these materials are often doped with activators. Comparison between CsI and NaI shows that both the larger size of Cs{sup +} relative to Na{sup +}, i.e., the greater atomic density of NaI, and the longer electron mean free path in NaI compared to CsI contribute to an increased probability for electron trapping at Tl sites in NaI versus CsI.

Wang Zhiguo; Gao Fei; Kerisit, Sebastien [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Xie Yulong [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Campbell, Luke W. [National Security Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

2012-07-01T23:59:59.000Z

251

Monte Carlo simulations of electron thermalization in alkali iodide and alkaline-earth fluoride scintillators  

SciTech Connect

A Monte Carlo model of electron thermalization in inorganic scintillators, which was developed and applied to CsI in a previous publication [Wang et al., J. Appl. Phys. 110, 064903 (2011)], is extended to another material of the alkali halide class, NaI, and to two materials from the alkaline-earth halide class, CaF2 and BaF2. This model includes electron scattering with both longitudinal optical (LO) and acoustic phonons as well as the effects of internal electric fields. For the four pure materials, a significant fraction of the electrons recombine with self-trapped holes and the thermalization distance distributions of the electrons that do not recombine peak between approximately 25 and 50 {per_thousand}nm and extend up to a few hundreds of nanometers. The thermalization time distributions of CaF2, BaF2, NaI, and CsI extend to approximately 0.5, 1, 2, and 7 ps, respectively. The simulations show that the LO phonon energy is a key factor that affects the electron thermalization process. Indeed, the higher the LO phonon energy is, the shorter the thermalization time and distance are. The thermalization time and distance distributions show no dependence on the incident {gamma}-ray energy. The four materials also show different extents of electron-hole pair recombination due mostly to differences in their electron mean free paths (MFPs), LO phonon energies, initial densities of electron-hole pairs, and static dielectric constants. The effect of thallium doping is also investigated for CsI and NaI as these materials are often doped with activators. Comparison between CsI and NaI shows that both the larger size of Cs+ relative to Na+, i.e., the greater atomic density of NaI, and the longer electron mean free path in NaI compared to CsI contribute to an increased probability for electron trapping at Tl sites in NaI versus CsI.

Wang, Zhiguo; Xie, YuLong; Campbell, Luke W.; Gao, Fei; Kerisit, Sebastien N.

2012-07-01T23:59:59.000Z

252

Magnetic-field induced absorption of zero-phonon lines in tris(bipyridine)ruthenium(2+) bis(hexafluorophosphate) and diperchlorate single crystals  

Science Journals Connector (OSTI)

Magnetic-field induced absorption of zero-phonon lines in tris(bipyridine)ruthenium(2+) bis(hexafluorophosphate) and diperchlorate single crystals ...

G. Hensler; E. Gallhuber; H. Yersin

1987-06-01T23:59:59.000Z

253

Investigation of spin phonon coupling in BiFeO{sub 3} based system by Fourier transform infrared spectroscopy  

SciTech Connect

In the present work, the low temperature infrared absorption spectra of BiFeO{sub 3} (BFO) are measured to explore the spin-phonon coupling in this compound. At 303?K, 4 weak transverse optic (TO) IR-active phonon modes E(TO6), E(TO7), E(TO8), and E(TO9) are observed. First two modes are corresponded to the Fe{sup 3+} cations caused by the internal vibration of FeO{sub 6} octahedra, E(TO8) is correlated to Fe-O bending vibration and E(TO9) is assigned to Fe-O stretching vibrations, respectively. At 213?K, two new modes E(TO5) and A1(TO3) are emerging out. Both are assigned to Fe{sup 3+} cations caused by the internal vibration of FeO{sub 6} octahedra. These modes get stronger and stronger with lowering the temperature due to the lattice contraction. When the temperatures decreases to T???213?K, an additional phonon mode is start appearing at around 638?cm{sup ?1} suggesting local lattice distortion of FeO{sub 6} octahedra. The temperature is corresponding with the FC and zero field cooled bifurcation temperature, which is related to the onset of spin glass behaviour. The occurrence of this additional phonon mode at this particular temperature suggests that there is strong spin-phonon coupling in BFO. This argument is further supported by the temperature dependence of this additional phonon peak. It shows anomaly around 124?K, which is related to spin reorientation of Fe{sup 3+} ions. This result clearly indicates that spin glass state and spin reorientation of Fe{sup 3+} is accompanied with the local structure distortion of FeO{sub 6} octahedra, providing evidence for the strong spin-phonon coupling in the BFO.

Gaikwad, V. M.; Acharya, S. A., E-mail: saha275@yahoo.com [Department of Physics, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur (India)

2013-11-21T23:59:59.000Z

254

Photo-Thermal Effects in Fiber Bragg Gratings  

Science Journals Connector (OSTI)

The photo-thermal effect describes the absorption of light and a change in grating characteristics via dn/dT, which can mask fast non-linear optical effects. The effect is...

Littler, Ian C; Grujic, Thomas; Eggleton, Benjamin J

255

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

256

Precision control of thermal transport in cryogenic single-crystal silicon devices  

E-Print Network (OSTI)

We report on the diffusive-ballistic thermal conductance of multi-moded single-crystal silicon beams measured below 1 K. It is shown that the phonon mean-free-path $\\ell$ is a strong function of the surface roughness characteristics of the beams. This effect is enhanced in diffuse beams with lengths much larger than $\\ell$, even when the surface is fairly smooth, 5-10 nm rms, and the peak thermal wavelength is 0.6 $\\mu$m. Resonant phonon scattering has been observed in beams with a pitted surface morphology and characteristic pit depth of 30 nm. Hence, if the surface roughness is not adequately controlled, the thermal conductance can vary significantly for diffuse beams fabricated across a wafer. In contrast, when the beam length is of order $\\ell$, the conductance is dominated by ballistic transport and is effectively set by the beam area. We have demonstrated a uniformity of $\\pm$8% in fractional deviation for ballistic beams, and this deviation is largely set by the thermal conductance of diffuse beams tha...

Rostem, Karwan; Colazo, Felipe A; Crowe, Erik J; Denis, Kevin L; Lourie, Nathan P; Moseley, Samuel H; Stevenson, Thomas R; Wollack, Edward J

2014-01-01T23:59:59.000Z

257

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

258

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

259

Seasonal thermal energy storage  

SciTech Connect

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

260

Evidence of spin phonon coupling in magnetoelectric NiFe{sub 2}O{sub 4}/PMN-PT composite  

SciTech Connect

The coupling of phonon with spin in strain coupled magnetoelectric NiFe{sub 2}O{sub 4} (NFO)/0.65Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–0.35PbTiO{sub 3} (PMN-PT) composite was investigated by temperature-dependent Raman spectroscopy and magnetic measurements in the range 30–350?°C. Pure NFO shows usual ferromagnetic behaviour in this temperature range while NFO/PMN-PT composite show dramatic change in magnetic moment across ferroelectric transition temperature (T{sub c}???180?°C) of PMN-PT. The temperature evolution of the Raman spectra for the composite shows significant phonon anomalies in T-site (Fe-O) and O-site (Ni/Fe-O) phonon modes at ferroelectric transition temperature is attributed to spin phonon coupling in NFO/PMN-PT composite. The strain mediated magnetoelectric coupling mechanism in this composite is apparent from the observed spin phonon interaction.

Ahlawat, Anju; Satapathy, S., E-mail: srinu73@rrcat.gov.in, E-mail: srinusatapathy@gmail.com; Gupta, P. K. [Nano Functional Materials Laboratory, Laser Materials Development and Devices Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)] [Nano Functional Materials Laboratory, Laser Materials Development and Devices Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Sathe, V. G.; Choudhary, R. J. [UGC-DAE Consortium for Scientific Research, Indore 452017 (India)] [UGC-DAE Consortium for Scientific Research, Indore 452017 (India)

2013-12-16T23:59:59.000Z

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.


261

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

262

Angle-Resolved Photoemission Spectroscopy on Electronic Structure and Electron-Phonon Coupling in Cuprate Superconductors  

SciTech Connect

In addition to the record high superconducting transition temperature (T{sub c}), high temperature cuprate superconductors are characterized by their unusual superconducting properties below T{sub c}, and anomalous normal state properties above T{sub c}. In the superconducting state, although it has long been realized that superconductivity still involves Cooper pairs, as in the traditional BCS theory, the experimentally determined d-wave pairing is different from the usual s-wave pairing found in conventional superconductors. The identification of the pairing mechanism in cuprate superconductors remains an outstanding issue. The normal state properties, particularly in the underdoped region, have been found to be at odd with conventional metals which is usually described by Fermi liquid theory; instead, the normal state at optimal doping fits better with the marginal Fermi liquid phenomenology. Most notable is the observation of the pseudogap state in the underdoped region above T{sub c}. As in other strongly correlated electrons systems, these unusual properties stem from the interplay between electronic, magnetic, lattice and orbital degrees of freedom. Understanding the microscopic process involved in these materials and the interaction of electrons with other entities is essential to understand the mechanism of high temperature superconductivity. Since the discovery of high-T{sub c} superconductivity in cuprates, angle-resolved photoemission spectroscopy (ARPES) has provided key experimental insights in revealing the electronic structure of high temperature superconductors. These include, among others, the earliest identification of dispersion and a large Fermi surface, an anisotropic superconducting gap suggestive of a d-wave order parameter, and an observation of the pseudogap in underdoped samples. In the mean time, this technique itself has experienced a dramatic improvement in its energy and momentum resolutions, leading to a series of new discoveries not thought possible only a decade ago. This revolution of the ARPES technique and its scientific impact result from dramatic advances in four essential components: instrumental resolution and efficiency, sample manipulation, high quality samples and well-matched scientific issues. The purpose of this treatise is to go through the prominent results obtained from ARPES on cuprate superconductors. Because there have been a number of recent reviews on the electronic structures of high-T{sub c} materials, we will mainly present the latest results not covered previously, with a special attention given on the electron-phonon interaction in cuprate superconductors. What has emerged is rich information about the anomalous electron-phonon interaction well beyond the traditional views of the subject. It exhibits strong doping, momentum and phonon symmetry dependence, and shows complex interplay with the strong electron-electron interaction in these materials. ARPES experiments have been instrumental in identifying the electronic structure, observing and detailing the electron-phonon mode coupling behavior, and mapping the doping evolution of the high-T{sub c} cuprates. The spectra evolve from the strongly coupled, polaronic spectra seen in underdoped cuprates to the Migdal-Eliashberg like spectra seen in the optimally and overdoped cuprates. In addition to the marked doping dependence, the cuprates exhibit pronounced anisotropy with direction in the Brillouin zone: sharp quasiparticles along the nodal direction that broaden significantly in the anti-nodal region of the underdoped cuprates, an anisotropic electron-phonon coupling vertex for particular modes identified in the optimal and overdoped compounds, and preferential scattering across the two parallel pieces of Fermi surface in the antinodal region for all doping levels. This also contributes to the pseudogap effect. To the extent that the Migdal-Eliashberg picture applies, the spectra of the cuprates bear resemblance to that seen in established strongly coupled electron-phonon superconductors such as Pb. On the other

Zhou, X.J.

2010-04-30T23:59:59.000Z

263

Light Old and New  

Science Journals Connector (OSTI)

The Sun, Moon and stars have been our lights since the earliest times. We have learned ... have much more recently filled our homes and streets with artificial lighting. We are, however, in danger of...natural lights

Bob Mizon

2002-01-01T23:59:59.000Z

264

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

265

Lighting | Department of Energy  

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

to installing LEDs in existing fixtures. Tips and Advice Tips: Lighting Lighting choices save you money. Energy-efficient light bulbs are available in a wide variety of sizes...

266

Natural lighting and skylights  

E-Print Network (OSTI)

There are many physiological and psychological factors which enter into the proper design of space for human occupancy. One of these elements is light. Both natural light and manufactured light are basic tools with which any designer must work...

Evans, Benjamin Hampton

1961-01-01T23:59:59.000Z

267

Parametric light generation  

Science Journals Connector (OSTI)

...potential to deliver coherent light with high spectral purity...universal constants such as the speed of light. Single- frequency CW...assessment of optical switching speeds in telecommunication technology...A (2003) Parametric light generation 2749 ment of...

2003-01-01T23:59:59.000Z

268

Thermal Control & System Integration  

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

269

The Light Reactions: A Guide to Recent Acquisitions for the Picture Gallery  

Science Journals Connector (OSTI)

...corresponding to a typical household battery. This reaction is the basis for energy...function in light harvesting as well as thermal dissipation of excess light is a high-resolution...polypeptide of photosystem II functions in thermal dissipation. Plant Cell 14, 1801-1816...

Sabeeha Merchant; Michael R. Sawaya

270

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.

271

Comprehensive phonon "map" offers direction for engineering new  

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

4 4 SHARE Comprehensive phonon "map" offers direction for engineering new thermoelectric devices Olivier Delaire, researcher in Oak Ridge National Laboratory's Materials Science and Technology Division, at the Spallation Neutron Source's Wide Angular-Range Chopper Spectrometer. Using neutrons to map heat as it propagates through materials, Delaire and his research group are studying how to design better thermoelectric devices that convert a temperature difference into an electric voltage. Olivier Delaire, researcher in Oak Ridge National Laboratory's Materials Science and Technology Division, at the Spallation Neutron Source's Wide Angular-Range Chopper Spectrometer. Using neutrons to map heat as it propagates through materials, Delaire and his research group are studying

272

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

273

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

274

Lighting Group: Links  

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

Links Links Links Organizations Illuminating Engineering Society of North America (IESNA) International Commission on Illumination (CIE) International Association of Lighting Designers (IALD) International Association of Energy-Efficient Lighting Lightfair International Energy Agency - Task 21: Daylight in Buildings: Design Tools and Performance Analysis International Energy Agency - Task 31: Daylighting Buildings in 21st Century National Association on Qualifications for the Lighting Professions (NCQLP) National Association of Independent Lighting Distributors (NAILD) International Association of Lighting Management Companies (NALMCO) Research Centers California Lighting Technology Center Lighting Research Center Lighting Research at Canada Institute for Research in Construction

275

Advanced Demand Responsive Lighting  

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

Demand Demand Responsive Lighting Host: Francis Rubinstein Demand Response Research Center Technical Advisory Group Meeting August 31, 2007 10:30 AM - Noon Meeting Agenda * Introductions (10 minutes) * Main Presentation (~ 1 hour) * Questions, comments from panel (15 minutes) Project History * Lighting Scoping Study (completed January 2007) - Identified potential for energy and demand savings using demand responsive lighting systems - Importance of dimming - New wireless controls technologies * Advanced Demand Responsive Lighting (commenced March 2007) Objectives * Provide up-to-date information on the reliability, predictability of dimmable lighting as a demand resource under realistic operating load conditions * Identify potential negative impacts of DR lighting on lighting quality Potential of Demand Responsive Lighting Control

276

Modeling LED street lighting  

Science Journals Connector (OSTI)

LED luminaires may deliver precise illumination patterns to control light pollution, comfort, visibility, and light utilization efficiency. Here, we provide simple equations to...

Moreno, Ivan; Avendaño-Alejo, Maximino; Saucedo-A, Tonatiuh; Bugarin, Alejandra

2014-01-01T23:59:59.000Z

277

Lighting | Open Energy Information  

Open Energy Info (EERE)

TODO: Add description List of Lighting Incentives Retrieved from "http:en.openei.orgwindex.php?titleLighting&oldid267174" Category: Articles with outstanding TODO tasks...

278

Cree LED Lighting Solutions Formerly LED Lighting Fixtures LLF...  

Open Energy Info (EERE)

LED Lighting Solutions Formerly LED Lighting Fixtures LLF Jump to: navigation, search Name: Cree LED Lighting Solutions (Formerly LED Lighting Fixtures (LLF)) Place: Morrisville,...

279

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

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

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

280

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

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

Phononic-Crystal-Based Acoustic Sieve for Tunable Manipulations of Particles by a Highly Localized Radiation Force  

Science Journals Connector (OSTI)

The ability to manipulate microscale and nanoscale particles is highly desirable for various applications ranging from targeting drug delivery to additive manufacturing. Here we report an acoustic sieve that is capable of aligning, trapping, sorting, and transferring a large number of particles according to their size or mass density, all in a tunable manner. The concept is based on the highly localized periodic radiation force induced by the resonance transmission of an acoustic wave across a phononic crystal plate, a phenomenon analogous to the surface-phonon-enhanced optical force, yet the physical concept has not been explored in acoustics. The acoustic sieve demonstrates the effective manipulation of massive particles using an artificially engineered acoustic field by a phononic crystal, and it has potential application for a wide range of applications.

Fei Li; Feiyan Cai; Zhengyou Liu; Long Meng; Ming Qian; Chen Wang; Qian Cheng; Menglu Qian; Xin Liu; Junru Wu; Jiangyu Li; Hairong Zheng

2014-06-11T23:59:59.000Z

282

Radiative cooling of bulk silicon by incoherent light pump  

SciTech Connect

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

283

Efficient generation of near infra-red single photons from the zero-phonon line of a single molecule  

E-Print Network (OSTI)

Using the zero-phonon line (ZPL) emission of a single molecule, we realized a triggered source of near-infra-red (lambda=785 nm) single photons at a high repetition rate. A Weierstrass solid immersion lens is used to image single molecules with an optical resolution of 300 nm (~0.4*lambda) and a high collection efficiency. Because dephasing of the transition dipole due to phonons vanishes at liquid helium temperatures, our source is attractive for the efficient generation of single indistinguishable photons.

Jean-Baptiste Trebbia; Hartmut Ruf; Philippe Tamarat; Brahim Lounis

2010-11-29T23:59:59.000Z

284

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

285

Desorption by phonon cascades for gas-solid systems with many physisorbed surface bound states  

Science Journals Connector (OSTI)

We give the extension of our quantum-statistical theory of desorption for systems with many physisorbed bound states in the surface potential. Rate equations are set up and the desorption time td is properly identified as the smallest eigenvalue of the matrix of transition probabilities. The latter are calculated exactly in second-order perturbation theory for a surface Morse potential. We show that desorption in weakly coupled systems with many bound states proceeds predominantly through one-phonon cascades. Two-phonon contributions are shown to be small. Desorption times are calculated for the He-LiF, He-NaF, He-graphite, H-NaCl, He-Ar, and Xe-W systems. The temperature regime over which a Frenkel-Arrhenius parametrization td=td0exp(QkBT) can be invoked is given. Our theory which is essentially parameter-free produces prefactors td0 in the whole experimental range of physisorption from 10-7 to 10-14 sec.

Z. W. Gortel; H. J. Kreuzer; R. Teshima

1980-12-15T23:59:59.000Z

286

Thermal Conductivity of Hexagonal Close-Packed Solid Helium Four at High Densities  

Science Journals Connector (OSTI)

Thermal conductivity measurements between 1.1° K and 7° K have been made on solid helium samples grown under constant pressures from 185 atm to 1050 atm. At high temperatures the phonon mean free path l¯ for the highest conductivity samples at six different densities is in good agreement with the expression, l¯=Aexp(?DbT), where ?D is the Debye temperature at T=0° K, A=2.5×10-8 cm, b=2.13. Several samples grown from gas repurified by an adsorption trap exhibited mean free paths in agreement with this expression over almost four orders of magnitude. Slightly impure samples showed a considerable attenuation in the peak thermal conductivity at pressures above 320 atm. There was some evidence for anisotropy of the thermal conductivity in the umklapp region and for Poiseuille flow in the low-temperature region, but both these effects were considerably smaller than reported by other investigators for specimens grown at lower pressures.

W. D. Seward, D. Lazarus, and S. C. Fain, Jr.

1969-02-05T23:59:59.000Z

287

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

288

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

289

Heat dissipation performance of a high-brightness LED package assembly using high-thermal conductivity filler  

Science Journals Connector (OSTI)

This paper presents a thermal analysis and experimental validation of natural convective heat transfer of a high-brightness light-emitting diode (LED) package assembly. The substrate...

Yung, K C; Liem, H; Choy, H S

2013-01-01T23:59:59.000Z

290

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

291

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

292

Thermal conductivity of nitrogenated ultrananocrystalline diamond films M. Shamsa,1,a  

E-Print Network (OSTI)

light on the nature of thermal conduction in partially disordered nanostructured materials and can be used for estimating the thermal resistance of doped UNCD films. © 2008 American Institute of Physics, chemical inertness, record high thermal conductivity, high mobility of charge carriers, and high electron

293

Spectrally Enhanced Lighting  

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

November 2007 November 2007 AfterImage + s p a c e 1 Spectrally Enhanced Lighting Spectrally Enhanced Lighting Brian Liebel, PE, LC Brian Liebel, PE, LC November 29, 2007 November 29, 2007 Federal Utilities Partnership Working Group Federal Utilities Partnership Working Group November 29, 2007 November 29, 2007 29 November 2007 AfterImage + s p a c e 2 Spectrally Enhanced Lighting Spectrally Enhanced Lighting Spectrally Enhanced Lighting Spectrally Enhanced Lighting This is not a technology; just a This is not a technology; just a different way to quantify light based on different way to quantify light based on well established scientific findings well established scientific findings Can be used in conjunction with ANY Can be used in conjunction with ANY type of lighting design to gain

294

Natural light controls and guides in buildings. Energy saving for electrical lighting, reduction of cooling load  

Science Journals Connector (OSTI)

Abstract The residential sector is responsible for approximately a quarter of energy consumption in Europe. This consumption, together with that of other buildings, mainly from the tertiary sector, makes up 40% of total energy consumption and 36% of CO2 emissions. Artificial lighting makes up 14% of electrical consumption in the European Union and 19% worldwide. Through the use of well-designed natural lighting, controlled by technologies or systems which guarantee accessibility from all areas inside buildings, energy consumption for lighting and air conditioning can be kept to a minimum. The authors of this article carried out a state of the art on the technologies or control systems of natural light in buildings, concentrating on those control methods which not only protect the occupants from direct solar glare but also maximize natural light penetration in buildings based on the occupants? preferences, whilst allowing for a reduction in electrical consumption for lighting and cooling. All of the control and/or natural light guidance systems and/or strategies guarantee the penetration of daylight into the building, thus reducing the electrical energy consumption for lighting and cooling. At the same time they improve the thermal and visual comfort of the users of the buildings. However various studies have also brought to light certain disadvantages to these systems.

E.J. Gago; T. Muneer; M. Knez; H. Köster

2015-01-01T23:59:59.000Z

295

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

296

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

297

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

298

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

E-Print Network (OSTI)

_?^(-1)?T^2 to? ??_?^(-1)?T when temperature increases. We also find ?_?^(-1) to be a non-monotonous function of n. These distinctive features of the new contribution can provide an effective way to identify flexural phonons in graphene through...

Zhao, Wei

2014-07-08T23:59:59.000Z

299

ccsd00003220, Low-q dispersion of transverse acoustic phonons in YBa 2 Cu 3 O 7  

E-Print Network (OSTI)

in the superconducting state of cuprates. In particular, Inelastic Neutron [1, 2] and X-ray [3] Scattering (INS, IXS High-resolution (#1;E=1.3 meV) inelastic X-ray scattering (IXS) in optimally doped untwinned YBa 2 Cu 3.70.Ck Keywords: Y-based cuprates, phonons, X-ray scattering. #3; Electronic address: gauzzi

300

Efficient generation of near infra-red single photons from the zero-phonon line of a single molecule  

E-Print Network (OSTI)

@u-bordeaux1.fr Abstract: Using the zero-phonon line (ZPL) emission of a single molecule, we realized immersion lens is used to image single molecules with an optical resolution of 300 nm (~0.4) and a high on controlled single molecule fluorescence", Phys. Rev. Lett. 83, 2722-2725 (1999). 4. B. Lounis, and W. E

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.


301

HEATS: Thermal Energy Storage  

SciTech Connect

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

302

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

303

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.

Stricker, Stefan

2014-01-01T23:59:59.000Z

304

Thermally efficient compact fluorescent fixture systems  

SciTech Connect

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

305

Crystal structure and phonon instability of high-temperature ?-Ca(BH4)2  

Science Journals Connector (OSTI)

Ca(BH4)2 is an interesting candidate for high-density hydrogen storage since it contains a large amount of hydrogen by weight and volume, and has been shown to reversibly release and absorb hydrogen, albeit at moderately high temperatures. Ca(BH4)2 undergoes a polymorphic transformation around 400–440 K from a low-temperature ?-Ca(BH4)2 phase to a high-temperature ?-Ca(BH4)2 phase. The crystal structure of ?-Ca(BH4)2 has only recently been resolved, and its thermodynamic phase stability is still not well understood. Using a combined experimental and theoretical approach, we have independently determined the structure of ?-Ca(BH4)2 and assessed its thermodynamic stability in the quasiharmonic approximation. The space-group P42/m gives an excellent agreement between experiment and theory, confirming the result of a recent study [Buchter et al., J. Phys. Chem. B 112, 8042 (2008)]. Using density-functional theory (DFT), we obtained a value of 10.9 kJ/mol for the static total-energy difference between the ?-Ca(BH4)2 and the ?-Ca(BH4)2 phases at T=0?K (without vibrations). Using DFT linear-response calculations, we find that the [1212?] acoustic phonon branch of ?-Ca(BH4)2 is dynamically unstable on the Brillouin-zone boundary at the T=0?K lattice parameters predicted from static DFT calculations. This phonon branch is very sensitive to the lattice parameters and can be stabilized by including lattice expansion due to zero-point vibrational contributions in the quasiharmonic approximation. This expanded stable ?-Ca(BH4)2 structure has a room-temperature vibrational entropy that is 16?J/mol?K higher than that of the ?-Ca(BH4)2 phase, qualitatively consistent with the observed stabilization of the former at elevated temperatures. The main contribution to the entropy difference between the ?-Ca(BH4)2 and ?-Ca(BH4)2 phases comes from the low-frequency region dominated by translational and rotational phonon modes.

Young-Su Lee; Yoonyoung Kim; Young Whan Cho; Daniel Shapiro; Chris Wolverton; Vidvuds Ozoli?š

2009-03-13T23:59:59.000Z

306

Non-thermal Plasma Chemistry Non-thermal Thermal  

E-Print Network (OSTI)

automotive industry optics biomedical technology environmental technology Plasma Technology Quote from: Pla-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

Greifswald, Ernst-Moritz-Arndt-Universität

307

Origin of the exceptional negative thermal expansion in metal-organic framework-5 Zn4O(1,4-benzenedicarboxylate)3  

Science Journals Connector (OSTI)

Metal organic framework-5 (MOF-5) was recently suggested to possess an exceptionally large negative thermal-expansion coefficient. Our direct experimental measurement of the thermal expansion of MOF-5 using neutron powder diffraction, in the temperature range of 4 to 600 K, shows that the linear thermal-expansion coefficient is ??16×10?6?K?1. To understand the origin of this large negative thermal-expansion behavior, we performed first-principles lattice dynamics calculations. The calculated thermal-expansion coefficients within quasiharmonic approximation agree well with the experimental data. We found that almost all low-frequency lattice vibrational modes (below ?23?meV) involve the motion of the benzene rings and the ZnO4 clusters as rigid units and the carboxyl groups as bridges. These so-called “rigid-unit modes” exhibit various degrees of phonon softening (i.e., the vibrational energy decreases with contracting crystal lattice) and thus are directly responsible for the large negative thermal expansion in MOF-5. Initial efforts were made to observe the phonon softening experimentally.

W. Zhou; H. Wu; T. Yildirim; J. R. Simpson; A. R. Hight Walker

2008-08-20T23:59:59.000Z

308

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

309

The play of light in crystals  

Science Journals Connector (OSTI)

And God said: 'Let there be light', and there was light. Genesis 1 3 When trapped in a crystal, light interacts with electrons, phonons (crystal lattice vibrations) and defects, generating many effects which are important not only for pure physics, by broadening our comprehension of nature, but also for practical applications. These include: photo-galvanic effects; discrete light scattering on lattice vibrations; laser radiation, first observed in ruby crystals; nonlinear effects resulting in generation of harmonics, so that under incidence of an intense coherent light beam onto a crystal it emits (or reflects) light of different wavelengths; transformation of the electron avalanche in semiconductors and semiconductor microstructures into the flow of coherent 'laser' light; and the capability of polarized light to magnetize electrons and nuclei in a crystal. This is far from being a complete list of the remarkable optical effects that scientists have observed and studied in crystals. Countless scientific papers and monographs have been devoted to these investigations, with quite a number of them leading to the award of Nobel Prizes. Here I'm going to speak very briefly, simplifying the problem as best I can, about a remarkable optical phenomenon in crystals: the generation by light of a quasiparticle called an 'exciton'. Why is it a 'quasiparticle', i.e. 'as if' a particle, and not a true particle? Because it exists in a crystal and not in vacuum and moves in a periodically changing field created by the atoms (ions) of the crystal lattice. In this respect, an electron in a crystal is also a quasiparticle. The idea of the exciton dawned upon Yakov Ilyich Frenkel, the well-known physicist of the Physico-Technical Institute (PhysTech), in 1931. Omitting the details that would require knowledge not only of quantum physics, but also of the history of its development, I'll say only that the Frenkel exciton is the excited state of the crystal, which is created, for instance, by light and which, arising in one of the crystal cells, spreads over the whole crystal, because the cells differ absolutely in no way from one another. Physicists call such a situation translation symmetry. Without going into the mechanism of the energy transfer from cell to cell, note only that the whole crystal, like a gigantic molecule, assumes in the excited exciton state. The word 'exciton' was coined by Frenkel himself, who had formed it from old Greek exito, meaning 'I excite'. Yakov Ilyich liked to give names to newly-discovered particles, and it was he who invented the name 'phonon' for the vibrational quantum of the crystal lattice. Few physicists know that the godfather of this term, forever established in physics, was Frenkel. When Frenkel reported his study on the exciton at PhysTech, one of his young colleagues couldn't help joking: 'Yasha, why didn't you name this particle in Russian---vozbudon'? (From the Russian vozbudit, meaning 'to excite'.) In contrast to the electron, which can also be excited by light in a crystal, the exciton is electrically neutral. Moving in the crystal it transfers energy, but not a charge. A neutral exciton is very much like an atom. But this 'atom' is generated by light within a crystal. The model of such a quasi-atom is particularly obvious in semiconductor crystals, where it can be conceived as an electron and a positively charged hole bound by Coulomb interaction. It is very much like the Dirac electron--positron pair, whose existence ensues from the well-known Dirac equation taking into account relativistic invariance---the same equation that has revealed to mankind the existence of antimatter. I think that it was under the influence of Dirac's ideas that the Englishman Mott and the American Wannier suggested an exciton model analogous to the positronium atom (an electron and a positron bound to each other by Coulomb interaction). It should be noted that both Mott and Wannier worked at Bristol University where Dirac had worked. Usually, the Wannier--Mott exciton is called hydrogen-like, bearing in mind its s

Boris Petrovitch Zakharchenya

2008-01-01T23:59:59.000Z

310

Thermal analysis of injectable, cellular-scale optoelectronics with pulsed power  

Science Journals Connector (OSTI)

...analysis|optoelectronics|light-emitting diode|scaling law| 1. Introduction...analysis for a single inorganic light-emitting diode in the tissue In the device...Thermal analysis for inorganic light-emitting diode arrays in the tissue The results...

2013-01-01T23:59:59.000Z

311

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

312

Solar Thermal Processes  

Science Journals Connector (OSTI)

The use of solar energy for desalination purposes was one of ... The process is based on the use of solar thermal energy to evaporate water, thus separating pure ... brine. In this chapter an overview of solar thermal

M.T. Chaibi; Ali M. El-Nashar

2009-01-01T23:59:59.000Z

313

Thermal Neutron Scattering  

Science Journals Connector (OSTI)

... of its title. It is not for the nuclear physicist, nor even for the neutron physicist, but for the student of solids and liquids. "Thermal ... physicist, but for the student of solids and liquids. "Thermal neutron ...

G. E. BACON

1968-11-09T23:59:59.000Z

314

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

315

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 in the mean-field approach 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.

Chernodub, M N; Verschelde, Henri

2014-01-01T23:59:59.000Z

316

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

317

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

2014-01-01T23:59:59.000Z

318

Capacitive Coupling of Two Transmission Line Resonators Mediated by the Phonon Number of a Nanoelectromechanical Oscillator  

E-Print Network (OSTI)

Detection of quantum features in mechanical systems at the nanoscale constitutes a challenging task, given the weak interaction with other elements and the available technics. Here we describe how the interaction between two monomodal transmission-line resonators (TLRs) mediated by vibrations of a nano-electromechanical oscillator can be described. This scheme is then employed for quantum non-demolition detection of the number of phonons in the nano-electromechanical oscillator through a direct current measurement in the output of one of the TLRs. For that to be possible an undepleted field inside one of the TLR works as a amplifier for the interaction between the mechanical resonator and the remaining TLR. We also show how how the non-classical nature of this system can be used for generation of tripartite entanglement and conditioned mechanical coherent superposition states, which may be further explored for detection processes.

O. P. de Sá Neto; M. C. de Oliveira; F. Nicacio; G. J. Milburn

2014-05-05T23:59:59.000Z

319

Phonon exchange in dilute Fermi-Bose mixtures: Tailoring the Fermi-Fermi interaction  

Science Journals Connector (OSTI)

We consider a mixture of a single-component Bose gas and a two-component Fermi gas at temperatures where the Bose gas is almost fully condensed. In such a mixture, two fermionic atoms can interact with each other by exchanging a phonon that propagates through the Bose condensate. We calculate the interaction potential due to this mechanism, and determine the effective s-wave scattering length for two fermions that interact, both directly by the interatomic potentials as well as by the above-mentioned exchange mechanism. We find that the effective scattering length is quite sensitive to changes in the condensate density, and becomes strongly energy dependent. In addition, we consider the mechanical stability of these mixtures, and also calculate the dispersion and the damping of the various collisionless collective modes of the gas.

M. J. Bijlsma; B. A. Heringa; H. T. C. Stoof

2000-04-05T23:59:59.000Z

320

Solid-State Lighting: Solid-State Lighting  

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

Solid-State Lighting Search Solid-State Lighting Search Search Help Solid-State Lighting HOME ABOUT THE PROGRAM R&D PROJECTS MARKET-BASED PROGRAMS SSL BASICS INFORMATION RESOURCES FINANCIAL OPPORTUNITIES EERE » Building Technologies Office » Solid-State Lighting Printable Version Share this resource Send a link to Solid-State Lighting: Solid-State Lighting to someone by E-mail Share Solid-State Lighting: Solid-State Lighting on Facebook Tweet about Solid-State Lighting: Solid-State Lighting on Twitter Bookmark Solid-State Lighting: Solid-State Lighting on Google Bookmark Solid-State Lighting: Solid-State Lighting on Delicious Rank Solid-State Lighting: Solid-State Lighting on Digg Find More places to share Solid-State Lighting: Solid-State Lighting on AddThis.com... Pause/Resume Photo of a large room with people standing around poster boards.

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 Group: Overview  

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

Overview Overview Overview of the Lighting Research Group The Lighting Research Group at Lawrence Berkeley National Laboratory performs research aimed at improving the energy efficiency of lighting systems in buildings and homes, throughout the State of California and across the Nation. The goal is to reduce lighting energy consumption by 50% over twenty years by improving the efficiency of light sources, and controlling and delivering illumination so that it is available, where and when needed, and at the required intensity. Research in the Lighting Group falls into three main areas: Sources and Ballasts, Light Distribution Systems and Controls and Communications. Click on a link below for more information about each of these research areas. Sources and Ballasts investigates next generation light sources, such as

322

Smart street lighting management  

Science Journals Connector (OSTI)

In this work, we propose a new street lighting energy management system in order to reduce ... demand” meaning that energy, in this case light, is provided only when needed. In ... demand model, which in the case...

S. Pizzuti; M. Annunziato; F. Moretti

2013-08-01T23:59:59.000Z

323

Adaptive Street Lighting Controls  

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

This two-part DOE Municipal Solid-State Street Lighting Consortium webinar focused on LED street lighting equipped with adaptive control components. In Part I, presenters Amy Olay of the City of...

324

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

325

Street light holography  

Science Journals Connector (OSTI)

The production of a hologram is demonstrated using only a camera aluminum foil and a mercury vapor street light.

R. R. Turtle

1977-01-01T23:59:59.000Z

326

Outdoor Lighting Resources  

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

DOE offers a variety of resources to guide municipalities, utilities, and others in their evaluation of LED street lighting products.

327

Optical phonon modes in InGaN/GaN dot-in-a-wire heterostructures grown by molecular beam epitaxy  

SciTech Connect

We report on the studies of optical phonon modes in nearly defect-free GaN nanowires embedded with intrinsic InGaN quantum dots by using oblique angle transmission infrared spectroscopy. These phonon modes are dependent on the nanowire fill-factor, doping densities of the nanowires, and the presence of InGaN dots. These factors can be applied for potential phonon based photodetectors whose spectral responses can be tailored by varying a combination of these three parameters. The optical anisotropy along the growth (c-) axis of the GaN nanowire contributes to the polarization agility of such potential photodetectors.

Titus, J.; Perera, A. G. U. [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States)] [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States); Nguyen, H. P. T.; Mi, Z. [Department of Electrical and Computer Engineering, McGill University, Montreal, Quebec H3A 2A7 (Canada)] [Department of Electrical and Computer Engineering, McGill University, Montreal, Quebec H3A 2A7 (Canada)

2013-03-25T23:59:59.000Z

328

Spin-phonon coupling in Gd(Co{sub 1/2}Mn{sub 1/2})O{sub 3} perovskite  

SciTech Connect

We have investigated the temperature-dependent Raman-active phonons and the magnetic properties of Gd(Co{sub 1/2}Mn{sub 1/2})O{sub 3} perovskite ceramics in the temperature range from 40?K to 300?K. The samples crystallized in an orthorhombic distorted simple perovskite, whose symmetry belongs to the Pnma space group. The data reveal spin-phonon coupling near the ferromagnetic transition occurring at around 120?K. The correlation of the Raman and magnetization data suggests that the structural order influences the magnitude of the spin-phonon coupling.

Silva, R. X. [Curso Ciências Naturais, Universidade Federal do Maranhão, Campus VII, 65400-000 Codó-MA (Brazil); Departamento de Física, Universidade Federal do Maranhão, Campus do Bacanga, 65085-580 São Luis-MA (Brazil); Reichlova, H. [Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6 (Czech Republic); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 12116 Praha 2 (Czech Republic); Marti, X. [Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6 (Czech Republic); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 12116 Praha 2 (Czech Republic); Department of Materials Science and Engineering, University of California Berkeley, Berkeley, California 94720-7300 (United States); Barbosa, D. A. B. [Departamento de Física, Universidade Federal do Maranhão, Campus do Bacanga, 65085-580 São Luis-MA (Brazil); Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, Florida 32224 (United States); Lufaso, M. W. [Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, Florida 32224 (United States); Araujo, B. S.; Ayala, A. P. [Departamento de Física, Universidade Federal do Ceará, Campus do Pici, P.O. Box 6030, 60455-970 Fortaleza-CE (Brazil); and others

2013-11-21T23:59:59.000Z

329

Experimental demonstration of mode-selective phonon excitation of 6H-SiC by a mid-infrared laser with anti-Stokes Raman scattering spectroscopy  

SciTech Connect

Mode-selective phonon excitation by a mid-infrared laser (MIR-FEL) is demonstrated via anti-Stokes Raman scattering measurements of 6H-silicon carbide (SiC). Irradiation of SiC with MIR-FEL and a Nd-YAG laser at 14 K produced a peak where the Raman shift corresponds to a photon energy of 119 meV (10.4 ?m). This phenomenon is induced by mode-selective phonon excitation through the irradiation of MIR-FEL, whose photon energy corresponds to the photon-absorption of a particular phonon mode.

Yoshida, Kyohei; Hachiya, Kan; Okumura, Kensuke; Mishima, Kenta; Inukai, Motoharu; Torgasin, Konstantin; Omer, Mohamed [Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)] [Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Sonobe, Taro [Kyoto University Research Administration Office, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)] [Kyoto University Research Administration Office, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Zen, Heishun; Negm, Hani; Kii, Toshiteru; Masuda, Kai; Ohgaki, Hideaki [Institute of Advanced Energy, Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)] [Institute of Advanced Energy, Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)

2013-10-28T23:59:59.000Z

330

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

331

Thermal Performance Benchmarking (Presentation)  

SciTech Connect

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

332

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

333

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

334

Resonant energy transfer in light harvesting and light emitting applications.  

E-Print Network (OSTI)

??The performance of light emitting and light harvesting devices is improved by utilising resonant energy transfer. In lighting applications, the emission energy of a semiconductor… (more)

Chanyawadee, Soontorn

2009-01-01T23:59:59.000Z

335

Solid-State Lighting: Solid-State Lighting Videos  

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

Solid-State Lighting Videos to Solid-State Lighting Videos to someone by E-mail Share Solid-State Lighting: Solid-State Lighting Videos on Facebook Tweet about Solid-State Lighting: Solid-State Lighting Videos on Twitter Bookmark Solid-State Lighting: Solid-State Lighting Videos on Google Bookmark Solid-State Lighting: Solid-State Lighting Videos on Delicious Rank Solid-State Lighting: Solid-State Lighting Videos on Digg Find More places to share Solid-State Lighting: Solid-State Lighting Videos on AddThis.com... Conferences & Meetings Presentations Publications Webcasts Videos Tools Solid-State Lighting Videos On this page you can access DOE Solid-State Lighting (SSL) Program videos. Photo of a museum art gallery with LED lights in track fixtures overhead. The City of Los Angeles LED Streetlight Program

336

Solid-State Lighting: Solid-State Lighting  

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

Lighting Lighting Printable Version Share this resource Send a link to Solid-State Lighting: Solid-State Lighting to someone by E-mail Share Solid-State Lighting: Solid-State Lighting on Facebook Tweet about Solid-State Lighting: Solid-State Lighting on Twitter Bookmark Solid-State Lighting: Solid-State Lighting on Google Bookmark Solid-State Lighting: Solid-State Lighting on Delicious Rank Solid-State Lighting: Solid-State Lighting on Digg Find More places to share Solid-State Lighting: Solid-State Lighting on AddThis.com... Pause/Resume Photo of a large room with people standing around poster boards. Register Now for DOE's 11th Annual SSL R&D Workshop January 28-30, join other SSL R&D professionals from industry, government, and academia to learn, share, and shape the future of lighting.

337

Solid-State Lighting: Solid-State Lighting Contacts  

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

About the About the Program Printable Version Share this resource Send a link to Solid-State Lighting: Solid-State Lighting Contacts to someone by E-mail Share Solid-State Lighting: Solid-State Lighting Contacts on Facebook Tweet about Solid-State Lighting: Solid-State Lighting Contacts on Twitter Bookmark Solid-State Lighting: Solid-State Lighting Contacts on Google Bookmark Solid-State Lighting: Solid-State Lighting Contacts on Delicious Rank Solid-State Lighting: Solid-State Lighting Contacts on Digg Find More places to share Solid-State Lighting: Solid-State Lighting Contacts on AddThis.com... Contacts Partnerships Solid-State Lighting Contacts For information about Solid-State Lighting, contact James Brodrick Lighting Program Manager Building Technologies Office U.S. Department of Energy

338

Solid-State Lighting: Adaptive Street Lighting Controls  

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

Adaptive Street Lighting Adaptive Street Lighting Controls to someone by E-mail Share Solid-State Lighting: Adaptive Street Lighting Controls on Facebook Tweet about Solid-State Lighting: Adaptive Street Lighting Controls on Twitter Bookmark Solid-State Lighting: Adaptive Street Lighting Controls on Google Bookmark Solid-State Lighting: Adaptive Street Lighting Controls on Delicious Rank Solid-State Lighting: Adaptive Street Lighting Controls on Digg Find More places to share Solid-State Lighting: Adaptive Street Lighting Controls on AddThis.com... Conferences & Meetings Presentations Publications Webcasts Videos Tools Adaptive Street Lighting Controls This two-part DOE Municipal Solid-State Street Lighting Consortium webinar focused on LED street lighting equipped with adaptive control components.

339

Alliant Energy Interstate Power and Light - Residential Renewable Energy  

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

Alliant Energy Interstate Power and Light - Residential Renewable Alliant Energy Interstate Power and Light - Residential Renewable Energy Rebates Alliant Energy Interstate Power and Light - Residential Renewable Energy Rebates < Back Eligibility Residential Savings Category Solar Buying & Making Electricity Heating & Cooling Water Heating Wind Maximum Rebate Solar Thermal Water Heater: $750 Program Info State Iowa Program Type Utility Rebate Program Rebate Amount Energy Efficient Solar PV: $1.25/kWh x estimated first year output Standard Solar PV: $0.75/kWh x estimated first year output Energy Efficient Wind: $0.75/kWh x estimated first year output Standard Wind: 0.25/kWh x estimated first year output Solar Thermal Water Heater (electric): $0.35 x annual kWh savings Solar Thermal Water Heater (natural gas): $2.50 x annual therm savings

340

Control of light speed: From slow light to superluminal light  

E-Print Network (OSTI)

A scheme for controlling light speed from slower-than-c to faster-than-c in an atomic system is presented in this paper. The scheme is based on far detuning Raman effect. Two far detuning coupling fields with small frequency difference will produce two absorptive peaks for the probe field in a $\\Lambda$ structure, and an optical pump between the two ground states can change the absorptive peaks into enhanced peaks, which makes the normal dispersion between the two peaks change into anomalous dispersion, so the probe field can change from slow light to superluminal propagation.

Qun-Feng Chen; Yong-Sheng Zhang; Bao-Sen Shi; Guang-Can Guo

2008-07-01T23:59:59.000Z

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.


341

Thermal Insulation in Solar Thermal Devices  

Science Journals Connector (OSTI)

Thermal Insulation is a device or a practice which is used in a system for minimising heat losses caused due to transfer of heat from hotter to colder regions. It is one of the cheapest methods of energy conse...

B. C. Raychaudhuri

1986-01-01T23:59:59.000Z

342

Emerging Lighting Technology  

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

Emerging Lighting Technology Emerging Lighting Technology Bruce Kinzey Pacific Northwest National Laboratory FUPWG - Portland, OR April 20, 2011 www.ssl.energy.gov 2 | Solid-State Lighting Program GATEWAY Demonstration Program * Purpose: demonstrate new SSL products in real-world applications that save energy, match or improve illumination, and are cost- effective * Demos generate critical field experience providing: - Feedback to manufacturers - Data for utility incentives - Market readiness of specific applications to users - Advancement in lighting knowledge Central Park, NY Photo: Ryan Pyle Smithsonian American Art Museum, Washington, D.C. Photo: Scott Rosenfeld www.ssl.energy.gov 3 | Solid-State Lighting Program LED Product Explosion www.ssl.energy.gov 4 | Solid-State Lighting Program LEDs are Not a Universal Lighting

343

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.

344

Solid-State Lighting: Solid-State Lighting Manufacturing Workshop  

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

Solid-State Lighting Solid-State Lighting Manufacturing Workshop to someone by E-mail Share Solid-State Lighting: Solid-State Lighting Manufacturing Workshop on Facebook Tweet about Solid-State Lighting: Solid-State Lighting Manufacturing Workshop on Twitter Bookmark Solid-State Lighting: Solid-State Lighting Manufacturing Workshop on Google Bookmark Solid-State Lighting: Solid-State Lighting Manufacturing Workshop on Delicious Rank Solid-State Lighting: Solid-State Lighting Manufacturing Workshop on Digg Find More places to share Solid-State Lighting: Solid-State Lighting Manufacturing Workshop on AddThis.com... Conferences & Meetings Past Conferences Presentations Publications Webcasts Videos Tools Solid-State Lighting Manufacturing Workshop Nearly 200 lighting industry leaders, chip makers, fixture and component

345

Transport properties, specific heat and thermal conductivity of GaN nanocrystalline ceramic  

SciTech Connect

The structural and transport properties (resistivity, thermopower and Hall effect), specific heat and thermal conductivity have been measured for GaN nanocrystalline ceramic prepared by hot pressing. It was found that the temperature dependence of resistivity in temperature range 10-300 K shows the very low activation energy, which is ascribed to the shallow donor doping originating in amorphous phase of sample. The major charge carriers are electrons, what is indicated by negative sign of Hall constant and Seebeck coefficient. The thermopower attains large values (-58 {mu}V/K at 300 K) and was characterized by linear temperature dependence which suggests the diffusion as a major contribution to Seebeck effect. The high electron concentration of 1.3x10{sup 19} cm{sup -3} and high electronic specific heat coefficient determined to be 2.4 mJ/molK{sup 2} allow to conclude that GaN ceramic demonstrates the semimetallic-like behavior accompanied by very small mobility of electrons ({approx}0.1 cm{sup 2}/V s) which is responsible for its high resistivity. A low heat conductivity of GaN ceramics is associated with partial amorphous phase of GaN grains due to high pressure sintering. - Graphical Abstract: Thermal resistivity and thermopower measurements indicates the high phonon scattering and lack of phonon-drag contribution to thermopower in GaN nanoceramics pressed under 4 GPa at 800 {sup o}C.

Sulkowski, Czeslaw [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland); ChuchmaLa, Andrzej, E-mail: andrzej.chuchmala@pwr.wroc.p [Wroclaw University of Technology, Institute of Electrical Engineering Fundamentals (I7), Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Zaleski, Andrzej J.; Matusiak, Marcin; Mucha, Jan; GLuchowski, PaweL; Strek, WiesLaw [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland)

2010-10-15T23:59:59.000Z

346

Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program:  

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

Reactor Pressure Vessel Task of Light Water Reactor Sustainability Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Initial Assessment of Thermal Annealing Needs and Challenges Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Initial Assessment of Thermal Annealing Needs and Challenges The most life-limiting structural component in light-water reactors (LWR) is the reactor pressure vessel (RPV) because replacement of the RPV is not considered a viable option at this time. LWR licenses are now being extended from 40y to 60y by the U.S. Nuclear Regulatory Commission (NRC) with intentions to extend licenses to 80y and beyond. The RPV materials exhibit varying degrees of sensitivity to irradiation-induced embrittlement (decreased toughness) , as shown in Fig. 1.1, and extending operation from

347

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

348

Light Water Reactor Sustainability Technical Documents | Department of  

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

Initiatives » Nuclear Reactor Technologies » Light Water Reactor Initiatives » Nuclear Reactor Technologies » Light Water Reactor Sustainability Program » Light Water Reactor Sustainability Technical Documents Light Water Reactor Sustainability Technical Documents September 30, 2011 Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Initial Assessment of Thermal Annealing Needs and Challenges The most life-limiting structural component in light-water reactors (LWR) is the reactor pressure vessel (RPV) because replacement of the RPV is not considered a viable option at this time. LWR licenses are now being extended from 40y to 60y by the U.S. Nuclear Regulatory Commission (NRC) with intentions to extend licenses to 80y and beyond. The RPV materials exhibit varying degrees of sensitivity to irradiation-induced embrittlement

349

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

SciTech Connect

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

350

Lighting the Night: Technology, Urban Life and the Evolution of Street Lighting [Light in Place  

E-Print Network (OSTI)

May 1912), 783. 8. "New Street Lights Increase Trade 3 5 Perlight, including street light, became part of America'sBeautiful-inspired street­ lights graced wealthy residen­

Holden, Alfred

1992-01-01T23:59:59.000Z

351

First-Principles Determination of Ultrahigh Thermal Conductivity of Boron Arsenide: A Competitor for Diamond?  

Science Journals Connector (OSTI)

We have calculated the thermal conductivities (?) of cubic III-V boron compounds using a predictive first principles approach. Boron arsenide is found to have a remarkable room temperature ? over 2000??W?m-1?K-1; this is comparable to those in diamond and graphite, which are the highest bulk values known. We trace this behavior in boron arsenide to an interplay of certain basic vibrational properties that lie outside of the conventional guidelines in searching for high ? materials, and to relatively weak phonon-isotope scattering. We also find that cubic boron nitride and boron antimonide will have high ? with isotopic purification. This work provides new insight into the nature of thermal transport at a quantitative level and predicts a new ultrahigh ? material of potential interest for passive cooling applications.

L. Lindsay; D. A. Broido; T. L. Reinecke

2013-07-08T23:59:59.000Z

352

Temperature Dependent Thermal Conductivity of Si/SiC Amorphous Multilayer Films  

SciTech Connect

The cross-plane thermal conductivity of 22 nm period Si/SiC amorphous multilayer films deposited by magnetron sputtering and measured using a differential 3{omega} method was found to decrease from 2.0 W/mK at 300 K to 1.1 W/mK at 80 K. Structural disorder in each of the constituent layers of the amorphous multilayer films was confirmed by high resolution transmission electron microscopy. Estimations of the relative contributions of interface and intrinsic layer thermal resistance based on microscopic phonon transport models indicate that mean free path reductions induced by the structural disorder within the multilayer films are responsible for the observed experimental trends.

Mazumder, M.; Solovyov, S.; Borca-Tasciuc, T.; Teehan, S.C.; Stinzianni, E.; Efstathiadis, H.

2010-03-01T23:59:59.000Z

353

Solid-State Lighting: Pedestrian-Friendly Nighttime Lighting  

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

Pedestrian-Friendly Nighttime Pedestrian-Friendly Nighttime Lighting to someone by E-mail Share Solid-State Lighting: Pedestrian-Friendly Nighttime Lighting on Facebook Tweet about Solid-State Lighting: Pedestrian-Friendly Nighttime Lighting on Twitter Bookmark Solid-State Lighting: Pedestrian-Friendly Nighttime Lighting on Google Bookmark Solid-State Lighting: Pedestrian-Friendly Nighttime Lighting on Delicious Rank Solid-State Lighting: Pedestrian-Friendly Nighttime Lighting on Digg Find More places to share Solid-State Lighting: Pedestrian-Friendly Nighttime Lighting on AddThis.com... Conferences & Meetings Presentations Publications Webcasts Videos Tools Pedestrian-Friendly Nighttime Lighting This November 19, 2013 webinar presented issues and considerations related to pedestrian-friendly nighttime lighting, such as color rendering, safety,

354

Lighting Research Group: Facilities  

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

Facilities Facilities Lighting Research Facilities at LBNL gonio-photometer Gonio-photometer We use this device to measure the intensity and direction of the light from a lamp or fixture. integrating sphere Integrating sphere This instrument allows us to get a fast and accurate measurement of the total light output of a lamp. We are not able to determine the direction of the light, only the intensity. power analyzer Power analyzer We use our power analyzer with the lamps in the gonio-photometer to measure input power, harmonic distortion, power factor, and many other signals that tell us how well a lamp is performing. spectro-radiometer Spectro-radiometer This device measures not only the intensity of a light source but also the intensity of the light at each wavelength.

355

Lighting Group: Software  

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

Software Software Lighting Software The Lighting Group has developed several computer programs in the course of conducting research on energy efficient lighting. Several of these programs have proven useful outside the research environment. One of the most popular programs for advanced lighting applications is Radiance. For more information on this program and its availability, click on the link below. RADIANCE Radiance is a suite of programs for the analysis and visualization of lighting in design. The primary advantage of Radiance over simpler lighting calculation and rendering tools is that there are no limitations on the geometry or the materials that may be simulated. Radiance is used by architects and engineers to predict illumination, visual quality and appearance of innovative design spaces, and by researchers to evaluate new

356

BALANCING NATURAL AND ARTIFICIAL LIGHTING IN ENERGY CONSERVING COMMERCIAL GREENHOUSES: A MONTHLY ENERGY MODEL  

Science Journals Connector (OSTI)

ABSTRACT A model is proposed to calculate the heating and lighting energy fluxes in any type of greenhouse. A probabilistic approach is used to estimate the fractional time that the lighting system has to provide supplemental light at a given level. The comparisons with a one-year measured data set are satisfactory. The lamps contributed significantly (42%) to the heating load. The energy conservation potential of adding a thermal curtain or a heat storage is determined. The balance between the natural and artificial light levels is discussed, as well as the constraints to the artificial lighting technology. KEYWORDS Greenhouse, artificial lighting, energy modelling, photosynthetically active radiation, storage, energy conservation.

Christian GUEYMARD

1988-01-01T23:59:59.000Z

357

Forbidden one-LO-phonon resonant Raman scattering and multiphonon scattering in pure CdTe crystals  

Science Journals Connector (OSTI)

We have performed experiments to show the resonant enhancement of the forbidden first-order LO mode at the E0+?0 gap of pure CdTe at 17 K. We explain this forbidden scattering in terms of intrinsic intraband Fröhlich interaction. In our experiments we also observe multiple-LO-phonon scattering up to four orders under both incoming and outgoing resonant conditions. The multiphonon spectra are briefly discussed and compared with other cadmium chalcogenides.

S. S. Islam, Shyama Rath, K. P. Jain, S. C. Abbi, C. Julien, and M. Balkanski

1992-08-15T23:59:59.000Z

358

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

359

Total Light Management  

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

Light Management Light Management Why is saving Energy Important World Electricity Consumption (2007) Top 20 Countries 0 500 1000 1500 2000 2500 3000 3500 4000 4500 U n i t e d S t a t e s C h i n a J a p a n R u s s i a I n d i a G e r m a n y C a n a d a A f r i c a F r a n c e B r a z i l K o r e a , S o u t h U n i t e d K i n g d o m I t a l y S p a i n A u s t r a l i a T a i w a n S o u t h A f r i c a M e x i c o S a u d i A r a b i a I r a n Billion kWh Source: US DOE Energy Information Administration Lighting Control Strategies 4 5 6 Occupancy/Vacancy Sensing * The greatest energy savings achieved with any lighting fixture is when the lights are shut off * Minimize wasted light by providing occupancy sensing or vacancy sensing 7 8 Daylight Harvesting * Most commercial space has enough natural light flowing into it, and the amount of artificial light being generated can be unnecessary * Cut back on the production of artificial lighting by

360

Domestic Lighting and Heating  

Science Journals Connector (OSTI)

... a 14 × 22 feet room with a nice spacious window at each end admitting surreptitious draughts in proportion to the amount of light they let in. ...

M. GHEURY DE BRAY

1926-02-06T23:59:59.000Z

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

Comparing Light Bulbs  

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

362

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

363

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

SciTech Connect

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

364

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

365

Lakeview Light and Power - Commercial Lighting Rebate Program | Department  

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

Lakeview Light and Power - Commercial Lighting Rebate Program Lakeview Light and Power - Commercial Lighting Rebate Program Lakeview Light and Power - Commercial Lighting Rebate Program < Back Eligibility Commercial Fed. Government Local Government Nonprofit State Government Savings Category Appliances & Electronics Commercial Lighting Lighting Program Info Funding Source Funded by Bonneville Power Administration Expiration Date 9/1/2013 State District of Columbia Program Type Utility Rebate Program Rebate Amount Commercial Lighting Installation: Up to 70% of cost Provider Lakeview Light and Power 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 funded by BPA and ends in September of 2010 or earlier if the funding is exhausted. Lakeview Light

366

Stimulated Brillouin scattering from multi-GHz-guided acoustic phonons in  

E-Print Network (OSTI)

laser light, we find that the spontaneous Brillouin signal develops a highly unusual multi modes can Bragg-scatter guided laser light into a counter-propagating optical mode, with a Doppler shift core is surrounded by a pure fused silica cladding, the difference in acoustic properties between

Loss, Daniel

367

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

368

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

SciTech Connect

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

369

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

370

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

371

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

SciTech Connect

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

372

AIRPORT LIGHTING Session Highlights  

E-Print Network (OSTI)

. These sessions were designed to offer practical-yet-specialized training and information outreach for personnel information on airport lighting and navigational aid equipment selection, funding, maintenance, and operation known as AirTAP, sponsored three airport-lighting training sessions at different locations in Minnesota

Minnesota, University of

373

LED Lighting Facts  

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

DOE's LED Lighting Facts® program showcases LED products for general illumination from manufacturers who commit to testing products and reporting performance results according to industry standards. For lighting buyers, designers, and energy efficiency programs, the program provides information essential to evaluating SSL products.

374

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

375

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

376

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 materials. Previous data yield no clear relation between interface resistance and interface structure resistance parallel to aligned carbon nanotube arrays. This work uses nanosecond thermoreflectance

Maruyama, Shigeo

377

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

378

Thermal Insulation of Houses  

Science Journals Connector (OSTI)

... THE Thermal Insulation (Dwellings) Bill which Mr. G. Nabarro introduced into the House of Commons on ... , sponsored by members of both major political parties, extends the principle of the Thermal Insulation (Industrial Buildings) Act of July 1957 to all new dwelling houses built in the ...

1958-02-22T23:59:59.000Z

379

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.

380

Columbia Water and Light - HVAC and Lighting Efficiency Rebates |  

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

Columbia Water and Light - HVAC and Lighting Efficiency Rebates Columbia Water and Light - HVAC and Lighting Efficiency Rebates Columbia Water and Light - HVAC and Lighting Efficiency Rebates < Back Eligibility Commercial Industrial Savings Category Heating & Cooling Commercial Heating & Cooling Cooling Heat Pumps Appliances & Electronics Commercial Lighting Lighting Maximum Rebate Lighting: 50% of invoiced cost up to $22,500 Program Info State Missouri Program Type Utility Rebate Program Rebate Amount HVAC Replacements: $570 - $3,770 Lighting: $300/kW reduction or half of project cost Provider Columbia Water and Light 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 measures are based upon the

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

Induction Lighting: An Old Lighting Technology Made New Again | Department  

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

Induction Lighting: An Old Lighting Technology Made New Again Induction Lighting: An Old Lighting Technology Made New Again Induction Lighting: An Old Lighting Technology Made New Again July 27, 2009 - 5:00am Addthis John Lippert Induction lighting is one of the best kept secrets in energy-efficient lighting. Simply stated, induction lighting is essentially a fluorescent light without electrodes or filaments, the items that frequently cause other bulbs to burn out quickly. Thus, many induction lighting units have an extremely long life of up to 100,000 hours. To put this in perspective, an induction lighting system lasting 100,000 hours will last more than 11 years in continuous 24/7 operation, and 25 years if operated 10 hours a day. The technology, however, is far from new. Nikola Tesla demonstrated induction lighting in the late 1890s around the same time that his rival,

382

Thermal Recovery Methods  

SciTech Connect

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

383

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

384

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

385

Reading Municipal Light Department - Business Lighting Rebate Program |  

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

Reading Municipal Light Department - Business Lighting Rebate Reading Municipal Light Department - Business Lighting Rebate Program Reading Municipal Light Department - Business Lighting Rebate Program < Back Eligibility Agricultural Commercial Fed. Government Industrial Institutional Local Government Nonprofit Schools State Government Savings Category Appliances & Electronics Commercial Lighting Lighting Maximum Rebate Commercial Customers: $10,000 per calendar year Municipal Customers: $15,000 per calendar year Program Info State Massachusetts Program Type Utility Rebate Program Rebate Amount T-8/T-5 Lamp with Electronic Ballasts: $11 - $35/fixture Interior High Output Lamp with Electronic Ballasts: $100/fixture De-lamping: $4 - $9/lamp Lighting Sensors: $20/sensor LED Exit Signs: $20/fixture Provider Incentive Programs

386

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

387

Nanoshell-mediated near-infrared thermal therapy of tumors under magnetic resonance guidance  

Science Journals Connector (OSTI)

...light into thermal energy. Nonetheless, pioneering...used for treatment planning, localization...the temperature distribution during the treatments...Echospeed, General Electric Medical Systems...Workstation, General Electric Medical Systems...sections to assess the distribution of tissue damage...

L. R. Hirsch; R. J. Stafford; J. A. Bankson; S. R. Sershen; B. Rivera; R. E. Price; J. D. Hazle; N. J. Halas; J. L. West

2003-01-01T23:59:59.000Z

388

Lighting fundamentals handbook: Lighting fundamentals and principles for utility personnel  

SciTech Connect

Lighting accounts for approximately 30% of overall electricity use and demand in commercial buildings. This handbook for utility personnel provides a source of basic information on lighting principles, lighting equipment, and other considerations related to lighting design. The handbook is divided into three parts. Part One, Physics of Light, has chapters on light, vision, optics, and photometry. Part Two, Lighting Equipment and Technology, focuses on lamps, luminaires, and lighting controls. Part Three, Lighting Design Decisions, deals with the manner in which lighting design decisions are made and reviews relevant methods and issues. These include the quantity and quality of light needed for visual tasks, calculation methods for verifying that lighting needs are satisfied, lighting economics and methods for evaluating investments in efficient lighting systems, and miscellaneous design issues including energy codes, power quality, photobiology, and disposal of lighting equipment. The handbook contains a discussion of the role of the utility in promoting the use of energy-efficient lighting. The handbook also includes a lighting glossary and a list of references for additional information. This convenient and comprehensive handbook is designed to enable utility lighting personnel to assist their customers in developing high-quality, energy-efficient lighting systems. The handbook is not intended to be an up-to-date reference on lighting products and equipment.

Eley, C.; Tolen, T. (Eley (Charles) Associates, San Francisco, CA (United States)); Benya, J.R. (Luminae Souter Lighting Design, San Francisco, CA (United States))

1992-12-01T23:59:59.000Z

389

Light and Bread Mold  

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

Light and Bread Mold Light and Bread Mold Name: CHASE Location: N/A Country: N/A Date: N/A Question: HOW CAN I EFICTIVELY TEST THE EFFECTS OF LIGHT ON BREAD MOLD? Replies: Hello Chase, In order to test the effects of light on bread mould you need to set up an experiment. There are two things you need to have in your experiment to make it a good experiment: 1. A 'control'. 2. Replicates 1. The 'control' Obviously in order to test the effects of light on bread mold you will need to actually shine some light on some bread mold and see what happens. This is your 'treatment'. However, it is vitally important that you know what would have happened without the treatment (in this case added light). Let's pretend that you do a test a you find that the bread mold under the light actually dies. How do you know if your bread mold died because light was added or because at that time of year all bread mold would die naturally or because by adding light you caused the temperature to rise and that killed the bread mold? The answer is that you do not know unless you have taken the trouble to find out with anouther test called the 'control'. The 'control' is a piece of bread mold, identical to the 'treatment' bread mold, which is placed in identical conditions to the 'treatment' piece of bread mold except that light is removed. Your 'control' piece of bread mold will need to be (to the best of your abillity) at the same temperature, in the same area, at similar humidity, etc. Part of the skill of designing a scientific experiment is being able think of all the possible things which might be affecting the bread mold and keeping them the same in both the 'treatment' and the 'control' (except, of course, for the presence of light) so that when you find a difference between the 'treatment' and the 'control' you are sure that it is the result of the light rather than something else.

390

Cool Pions move at less than the speed of light  

E-Print Network (OSTI)

At nonzero temperature, pions propagate through a thermal medium at less than the speed of light. About low temperature, this effect begins not at $\\sim T^2$, but at next to leading order, $\\sim T^4$. We also derive the generalization of the relation of Gell-Mann, Oakes, and Renner to nonzero temperature.

Robert D. Pisarski; Michel Tytgat

1996-06-27T23:59:59.000Z

391

Scattering Solar Thermal Concentrators  

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

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...

392

Florida Power and Light - Business Energy Efficiency Rebates | Department  

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

Florida Power and Light - Business Energy Efficiency Rebates Florida Power and Light - Business Energy Efficiency Rebates Florida Power and Light - Business Energy Efficiency Rebates < Back Eligibility Commercial Industrial Institutional Local Government Nonprofit Schools State Government Savings Category Home Weatherization Commercial Weatherization Heating & Cooling Commercial Heating & Cooling Cooling Manufacturing Other Construction Heat Pumps Heating Appliances & Electronics Commercial Lighting Lighting Insulation Design & Remodeling Water Heating Windows, Doors, & Skylights Maximum Rebate Chillers: $99/kW reduced Thermal Energy Storage: $580/kW shifted DX AC: $165/kW reduced (Unitary); $495/kW reduced (Room Unit) Energy Recovery Ventilators: $415/kW reduced Demand Control Ventilation: $600/kW reduced ECM Motors for DX Systems: $100/kW reduced

393

Lighting Basics | Department of Energy  

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

Lighting Basics Lighting Basics Lighting Basics August 15, 2013 - 5:12pm Addthis Text Version There are many different types of artificial lights, all of which have different applications and uses. Types of lighting include: Fluorescent Lighting High-intensity Discharge Lighting Incandescent Lighting LED Lighting Low-pressure Sodium Lighting. Which type is best depends on the application. See the chart below for a comparison of lighting types. Lighting Comparison Chart Lighting Type Efficacy (lumens/watt) Lifetime (hours) Color Rendition Index (CRI) Color Temperature (K) Indoors/Outdoors Fluorescent Straight Tube 30-110 7000-24,000 50-90 (fair to good) 2700-6500 (warm to cold) Indoors/outdoors Compact Fluorescent 50-70 10,000 65-88 (good) 2700-6500 (warm to cold) Indoors/outdoors

394

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

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

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...

395

Lighting Renovations | Department of Energy  

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

Lighting Renovations Lighting Renovations Lighting Renovations October 16, 2013 - 4:54pm Addthis 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 focuses on the renewable energy opportunities, energy efficiency may also present amble opportunity for energy and cost savings. Renewable Energy Options for Lighting Renovations Daylighting Photovoltaics Daylighting Daylighting maximizes the use of natural light in a space to reduce the need for artificial lighting. Incorporating daylighting into a lighting strategy should occur during the planning stage of design since it affects all aspects. Ambient light dimming controls are critical in daylighting, since the

396

Lighting Group: Controls: IBECS  

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

IBECS IBECS Integrated Building Environmental Communications System Objective The overall technical goal of the IBECS project is to develop an integrated building equipment communications network that will allow appropriate automation of lighting and envelope systems to increase energy efficiency, improve building performance, and enhance occupant experience in the space. This network will provide a low-cost means for occupants to control local lighting and window systems, thereby improving occupant comfort, satisfaction and performance. A related goal is to improve existing lighting control components and accelerate development of new daylighting technologies that will allow daylighting to be more extensively applied to a larger proportion of building floor space.

397

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

398

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

399

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

400

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

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

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

402

Spectrally Enhanced Lighting  

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

Spectrally enhanced lighting (SEL) is a cost-effective, low-risk design method for achieving significant energy savings. It entails shifting the color of lamps from the warmer to the cooler (whiter) end of the color spectrum, more closely matching daylight. Studies show that, with this color shift, occupants perceive lighting to be brighter and they are able to see more clearly. Since SEL provides the same levels of visual acuity with fewer lumens of output, SEL installations can be designed using fewer lamps or lower wattage lamps than traditional lighting.

403

Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program:  

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

Initial Assessment of Thermal Annealing Needs and Challenges Initial Assessment of Thermal Annealing Needs and Challenges Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Initial Assessment of Thermal Annealing Needs and Challenges The most life-limiting structural component in light-water reactors (LWR) is the reactor pressure vessel (RPV) because replacement of the RPV is not considered a viable option at this time. LWR licenses are now being extended from 40y to 60y by the U.S. Nuclear Regulatory Commission (NRC) with intentions to extend licenses to 80y and beyond. The RPV materials exhibit varying degrees of sensitivity to irradiation-induced embrittlement (decreased toughness) , as shown in Fig. 1.1, and extending operation from 40y to 80y implies a doubling of the neutron exposure for the RPV. Thus,

404

Peninsula Light Company - Commercial Efficient Lighting Rebate Program |  

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

Peninsula Light Company - Commercial Efficient Lighting Rebate Peninsula Light Company - Commercial Efficient Lighting Rebate Program Peninsula Light Company - Commercial Efficient Lighting Rebate Program < Back Eligibility Commercial Savings Category Appliances & Electronics Commercial Lighting Lighting Program Info State District of Columbia Program Type Utility Rebate Program Rebate Amount General: 30% - 70% of cost Provider Peninsula Light Company 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. Customers who upgrade to highly efficient fixtures and systems are eligible to receive a rebate generally covering 30% - 70% of the project cost. These retrofits improve light quality and reduce energy costs in participating facilities. PLC

405

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.

406

Lots of Light Literature  

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

Lots of Light Literature Lots of Light Literature The Teacher Resource Center contains a great variety of resources for all areas of science K-12. For the concepts of light here is a sampling of some of these resources. Science is Elementary - Spring 1995, vol. 6, no. 4. Science is Elementary is produced by the Museum Institute for Teaching Science, 79 Milk Street, Suite 210, Boston, MA 02109-3903. Science is Elementary is a newsletter we have admired for years. The topic of this issue deals with Color and Light. It contains content information to the teacher, trade secrets or teaching tips, "Book Looking" section and the section call "Sciencing" which includes a variety of activities. Science is Elementary is published quarterly. Subscription cost is: $22.00/year.

407

Solid-State Lighting  

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

-U.S. Senator Jeff Bingaman, Chair, Senate Committee on Energy and Natural Resources 2013-2025 * The Future of LED General Lighting 2013-2025 * The Promise of OLED General...

408

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

409

Comparing Light Bulbs  

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

Comparing Light Bulbs Grades: K-4, 5-8 Topic: Energy Efficiency and Conservation Owner: U.S. Environmental Protection Agency This educational material is brought to you by the U.S....

410

Effect of wettability on light oil steamflooding  

SciTech Connect

This report summarizes NIPER's research on four interrelated topics for Light Oil Steamflooding. Four interrelated topics are described: The methodology for measuring capillary pressure and wettability at elevated temperature, the use of silylating agents to convert water-wet Berea sandstones or unconsolidated quartz sands to oil-wetted surfaces, the evaluation of the thermal hydrolytic stability of these oil-wet surfaces for possible use in laboratory studies using steam and hot water to recover oil, and the effect of porous media of different wettabilities on oil recovery where the porous media is first waterflooded and then steamflooded.

Olsen, D.K.

1991-12-01T23:59:59.000Z

411

Effect of wettability on light oil steamflooding  

SciTech Connect

This report summarizes NIPER`s research on four interrelated topics for Light Oil Steamflooding. Four interrelated topics are described: The methodology for measuring capillary pressure and wettability at elevated temperature, the use of silylating agents to convert water-wet Berea sandstones or unconsolidated quartz sands to oil-wetted surfaces, the evaluation of the thermal hydrolytic stability of these oil-wet surfaces for possible use in laboratory studies using steam and hot water to recover oil, and the effect of porous media of different wettabilities on oil recovery where the porous media is first waterflooded and then steamflooded.

Olsen, D.K.

1991-12-01T23:59:59.000Z

412

Composition and temperature-induced effects on the phonon spectra of narrow-band-gap Hg1-xCdxTe  

Science Journals Connector (OSTI)

Compositional and temperature-dependent Raman and infrared spectroscopies on the narrow-band-gap II-VI alloy, Hg1-xCdxTe (0?x?0.29), are reported in this paper. Raman measurements over this composition range confirm the two-mode behavior of the optical phonons in the alloy, with the frequency positions exhibiting a monotonic change with the alloy composition x. A resonant enhancement of the HgTe-like forbidden longitudinal-optic mode is observed near the E1 band gap of the alloy. Alloy induced perturbations on the electronic states lead to a smearing and a weakening of the resonance with increasing alloy composition. The optical phonons in this small band-gap alloy exhibit anomalous frequency shifts as a function of temperature vis-à-vis normal wide-band-gap semiconductors. This anomaly is attributed to the strong electron-phonon interaction in narrow-band-gap systems, which overshadows the dominant anharmonic (phonon-phonon) interaction in usual semiconductors. A detailed compositional dependent second-order Raman spectra is also reported.

Shyama Rath, K. P. Jain, S. C. Abbi, C. Julien, and M. Balkanski

1995-12-15T23:59:59.000Z

413

Sandia National Laboratories: (Lighting and) Solid-State Lighting...  

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

on the third and upcoming revolution (illumination). Topics cover the basics of light-emitting diode (LED) operation; a 200-year history of lighting technology; the importance of...

414

Theory of delayed thermal fluorescence  

Science Journals Connector (OSTI)

A theory of nonradiative thermal activation involved in delayed thermal fluorescence has been developed from the viewpoint of the breakdown of the Born-Oppenheimer adiabatic approximation.

S. H. Lin

1971-01-01T23:59:59.000Z

415

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

416

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

417

Science Highlights- Center for Solar and Thermal Energy Conversion  

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

Modes by an Integrated Acoustic Etalon Heterobarrier for Converting Hot-Phonon Energy to Electric Potential MOCVD Growth of Vertically Aligned InGaN Nanowires Resolving...

418

Science Highlights- Center for Solar and Thermal Energy Conversion  

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

1 - Abstracts and Highlight Slides Efficiency of Thermoelectric Energy Conversion in Biphenyl-dithiol Junctions: Effect of Electron-Phonon Interactions Plasmonic Backscattering...

419

Nonequilibrium Green’s function method for quantum thermal transport  

Science Journals Connector (OSTI)

This review deals with the nonequilibrium Green’s function (NEGF) method applied to the problems of energy transport due to atomic vibrations (phonons),...

Jian-Sheng Wang; Bijay Kumar Agarwalla; Huanan Li; Juzar Thingna

2014-12-01T23:59:59.000Z

420

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

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

Lighting Design | Department of Energy  

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

Design Design Lighting Design July 29, 2012 - 6:28pm Addthis Energy-efficient indoor and outdoor lighting design focuses on ways to improve both the quality and efficiency of lighting. | Photo courtesy of ©iStockphoto.com/chandlerphoto. Energy-efficient indoor and outdoor lighting design focuses on ways to improve both the quality and efficiency of lighting. | Photo courtesy of ©iStockphoto.com/chandlerphoto. How does it work? Buy ENERGY STAR-rated lighting for the highest quality, energy-efficient lighting. Use timers and other controls to turn lights on and off. Use outdoor solar lighting. Energy-efficient indoor and outdoor lighting design focuses on ways to improve both the quality and efficiency of lighting. If you're constructing a new house, consider lighting as part of your whole-house design -- an

422

LED Lighting | Department of Energy  

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

LED Lighting LED Lighting LED Lighting July 29, 2012 - 4:43pm Addthis LED Lighting What are the key facts? Quality LED products can last 25 times longer than an incandescent bulb and use 75% less energy. LEDs are directional, focusing light in ways that are useful in homes and commercial settings. The light-emitting diode (LED) is one of today's most energy-efficient and rapidly-developing lighting technologies. Quality LED light bulbs last longer, are more durable, and offer comparable or better light quality than other types of lighting. Check out the top 8 things about LEDs to learn more. Energy Savings LED is a highly energy efficient lighting technology, and has the potential to fundamentally change the future of lighting in the United States. Residential LEDs -- especially ENERGY STAR rated products -- use at least

423

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 ............................................................................... 7 Measurement results: Kyosemi.................................................................. 9

424

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

425

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

426

Solar Thermal Energy Storage  

Science Journals Connector (OSTI)

Various types of thermal energy storage systems are introduced and their importance and desired characteristics are outlined. Sensible heat storage, which is one of the most commonly used storage systems in pract...

E. Paykoç; S. Kakaç

1987-01-01T23:59:59.000Z

427

Neutron stars - thermal emitters  

E-Print Network (OSTI)

Confronting theoretical models with observations of thermal radiation emitted by neutron stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the neutron stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized neutron stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized neutron stars to the observed thermally emitting objects.

Potekhin, A Y; Pons, J A

2014-01-01T23:59:59.000Z

428

LightManufacturing | Open Energy Information  

Open Energy Info (EERE)

LightManufacturing LightManufacturing Jump to: navigation, search Logo: LightManufacturing Name LightManufacturing Address 855 4th Street Place California Zip 93449 Sector Solar Product heliostat, helisotats, sun trackers, solar thermal manufacturing systems. Year founded 2009 Number of employees 11-50 Company Type For Profit Phone number 415 796-6475 Website http://www.lightmanufacturings Coordinates 35.135012°, -120.6228° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":35.135012,"lon":-120.6228,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

429

Texas Thermal Comfort Report  

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

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

430

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

431

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

432

Solid-State Lighting: Municipal Consortium LED Street Lighting Workshop  

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

Los Angeles, CA to someone Los Angeles, CA to someone by E-mail Share Solid-State Lighting: Municipal Consortium LED Street Lighting Workshop Presentations and Materials-Los Angeles, CA on Facebook Tweet about Solid-State Lighting: Municipal Consortium LED Street Lighting Workshop Presentations and Materials-Los Angeles, CA on Twitter Bookmark Solid-State Lighting: Municipal Consortium LED Street Lighting Workshop Presentations and Materials-Los Angeles, CA on Google Bookmark Solid-State Lighting: Municipal Consortium LED Street Lighting Workshop Presentations and Materials-Los Angeles, CA on Delicious Rank Solid-State Lighting: Municipal Consortium LED Street Lighting Workshop Presentations and Materials-Los Angeles, CA on Digg Find More places to share Solid-State Lighting: Municipal Consortium

433

Better Medicine Through Proper Lighting  

Science Journals Connector (OSTI)

Adverse lighting conditions can seriously hinder medical diagnoses. Through the use of properly filtered light, medical professionals may dramatically improve viewing conditions for...

Czajkowski, Amber

434

Pressure dependence of phonons and excitons in InSe films prepared by metal-organic chemical vapor deposition  

Science Journals Connector (OSTI)

The pressure dependence of the Raman spectra of phase-pure InSe thin films prepared by the low-pressure metal-organic chemical vapor deposition technique has been studied using a diamond-anvil high-pressure cell. Enhancement in the intensities of the Raman modes has been observed as a result of pressure-induced “tuning” of the energy of the M1-type hyperbolic exciton in InSe at ?2.54 eV through discrete incident laser photon energies. The pressure coefficients of the phonon modes and of the hyperbolic exciton in InSe have been determined.

In-Hwan Choi and Peter Y. Yu

2003-10-27T23:59:59.000Z

435

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

SciTech Connect

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

436

Absorption intensities of the multipole-field-induced zero-phonon transitions in solid HD, HT, and DT  

Science Journals Connector (OSTI)

Closed-form theoretical expressions are derived for the integrated absorption coefficient of various zero-phonon single and double transitions in heteronuclear isotopic variants of hydrogen in condensed phase. Theoretical analysis predicts a different kind of double transition in the spectra of solid HD, HT, and DT, where the rotational energy of one molecule changes by three quanta and the rotational energy of another molecule simultaneously changes by at least three quanta. The expressions for double transitions given in this paper may, for example, be applied to double transitions involving para-H2–HD or ortho-D2–HD pairs.

Adya P. Mishra; Robert W. Field; S. V. N. Bhaskara Rao; Richard D’Souza; T. K. Balasubramanian

2003-04-23T23:59:59.000Z

437

Momentum-dependent electron self-energy in nearly ferromagnetic systems: Comparison of spin fluctuations and phonons  

Science Journals Connector (OSTI)

The self-energy ? is calculated in a two-parameter spin-fluctuation model. In contrast to the electron-phonon system, paramagnons have considerable spectral weight at large energies, O(EF), even very near the magnetic transition. The momentum dependence of ? is important and leads to significant changes in the chemical potential and in the ratio m*/m and to restoration of particle conservation, which is violated in the paramagnon model. The Eliashberg strong-coupling theory must be modified. Our results support resolution of the question of paramagnon model versus Fermi-liquid theory in favor of the latter.

D. Fay, O. Loesener, and J. Appel

1988-03-01T23:59:59.000Z

438

The key role of charge carriers scattering on polar optical phonons in semiconductors for thermoelectric energy conversion  

Science Journals Connector (OSTI)

Abstract The Boltzmann equation for charge carriers in n-type InSb is solved by numerical procedure. Temperature and donor atoms concentration dependences of kinetic coefficients are studied with respect to the thermoelectric energy conversion efficiency. It is found that the mechanism of the charge carriers scattering on polar optical phonons is of crucial importance for thermoelectric figure of merit of semiconductors. High thermoelectric efficiency of compounds and alloys comprising such heavy atoms as Pb or Bi is explained by weakening of the above mentioned scattering mechanism due to gigantic values of dielectric constants of substances caused by high polarizability of heavy atoms.

V.G. Orlov; G.S. Sergeev

2013-01-01T23:59:59.000Z

439

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

440

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

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

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

Solar lighting | Open Energy Information  

Open Energy Info (EERE)

lighting lighting Jump to: navigation, search Introductory Facts About Solar Lights It is not just a normal light bulb.The solar light consists of a LED or Light Emitting Diode, which draw little power. Coupled with constantly recharging batteries, you will never run out of light! They will save the customer money. By Replacing all outdoor lighting with solar lights there is no need to plug in to the electrical system. The lights will automatically turn on at dusk and will be charged during the day. They help out the environment.Not only does not plugging in to the power system save money but also energy, therefore protecting the Earth. Easy to Install No wires necessary, just pop in the battery. They come in all designs Just because they are solar lights doesn't

442

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

443

Phonon dispersion of graphite by inelastic x-ray scattering * J. Maultzsch,1, E. Dobardzi,2 S. Reich,3 I. Milosevi,2 M. Damnjanovi,2 A. Bosak,4 M. Krisch,4 and  

E-Print Network (OSTI)

quality. It has been partly measured by inelastic neutron scattering INS , electron- energy lossPhonon dispersion of graphite by inelastic x-ray scattering M. Mohr,1, * J. Maultzsch,1, E-plane phonon dispersion of graphite obtained from inelastic x-ray scattering, including the optical

Nabben, Reinhard

444

Sandia National Laboratories: White Light Creation Architectures  

NLE Websites -- All DOE Office Websites (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...

445

Wisconsin Business Sheds Light on Lighting | Department of Energy  

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

Wisconsin Business Sheds Light on Lighting Wisconsin Business Sheds Light on Lighting Wisconsin Business Sheds Light on Lighting April 29, 2010 - 4:59pm Addthis When this photograph was taken, the upper floors of Wisconsin’s Department of Transportation were using a new lighting plan from EPS, while the lower ones were still using the pre-audit lighting scheme. | Photo Courtesy of Energy Performance Specialists, LLC When this photograph was taken, the upper floors of Wisconsin's Department of Transportation were using a new lighting plan from EPS, while the lower ones were still using the pre-audit lighting scheme. | Photo Courtesy of Energy Performance Specialists, LLC Joshua DeLung Wisconsin-based Energy Performance Specialists LLC is helping clients reduce energy consumption in a very simple way-by just using less.

446

National Synchrotron Light Source  

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

Environmental Assessment Environmental Assessment Proposed Upgrade and Improvement of the National Synchrotron Light Source Complex at Brookhaven National Laboratory, Upton, New York This Environmental Assessment addresses the proposed action by the U.S. Department of Energy to upgrade the facilities of the National Synchrotron Light Source Complex, namely the National Synchrotron Light Source (NSLS), the Accelerator Test Facility and the Source Development Laboratory. The environmental effects of a No-Action Alternative as well as a Proposed Action are evaluated in the Environmental Assessment. The “NSLS Environmental Assessment Fact Sheet” link below leads to a one-page summary of the Environmental Assessment. The “NSLS Environmental Assessment” link below leads to the whole 41-page

447

Lighting Technology Panel  

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

Technology Panel Technology Panel Federal Utility Partnership Working Group N b 2009 November 1 1 8, 2009 Doug Avery Southern California Edison Southern California Edison National Energy Conservation M d t Mandates * There are Federal and State Mandates to reduce energy consumption - California Investor Owned Electric Utilities are ordered to save around 3 Billion kWh's each y year from 2007-2113 - Federal buildings ordered to reduce electrical Federal buildings ordered to reduce electrical energy consumption 35% by 2012 Energy Consump ption gy Lighting accounts for 42 7% of energy consumption Lighting accounts for 42.7% of energy consumption Data Courtesy of SDG&E Data Courtesy of SDG&E Energy Consump ption gy More than ¾ of the lighting load is non-residential. Data Courtesy of SDG&E

448

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

449

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

450

Locations Everyone: Lights, Camera, Action!  

Science Journals Connector (OSTI)

Locations Everyone: Lights, Camera, Action! ... Harvard Institute of Proteomics Harvard Medical School ...

Robert F. Murphy; Joshua LaBaer

2008-12-05T23:59:59.000Z

451

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

452

Nonlinear theory of slow light  

Science Journals Connector (OSTI)

...describes a signal moving with the speed of light on a constant background (fast...profile, propagates with the speed of light, reaches the slow-light soliton...field and propagating with the speed of light has reached the soliton. In figure-6...

2011-01-01T23:59:59.000Z

453

Recent applications of thermal imagers for security assessment  

SciTech Connect

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

454

Another Side of Light - D  

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

D. Three quantum phenomena D. Three quantum phenomena In fluorescence, matter absorbs light waves of a high frequency and then emits light of the same or lower frequency. This process was studied and named by George Gabriel Stokes in the mid-19th century. Today, fluorescence is familiar to us from fluorescent light bulbs. A fluorescent bulb's filament produces ultraviolet light, which is absorbed by the bulb's inner coating, which then emits lower-frequency visible light-more visible light than an incandescent bulb produces with the same wattage. According to the hypothesis of light quanta, during fluorescence an atom absorbs a quantum of light whose energy is proportional to the light wave's frequency. If the atom doesn't supply any extra energy of its own, the light quantum emitted should either have the same energy or less energy

455

Tips: Lighting | Department of Energy  

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

Lighting Lighting Tips: Lighting May 4, 2012 - 3:16pm Addthis Lighting Choices Save You Money. Energy-efficient light bulbs are available in a wide variety of sizes and shapes. Lighting Choices Save You Money. Energy-efficient light bulbs are available in a wide variety of sizes and shapes. What does this mean for me? Replacing 15 inefficient incandescent bulbs in your home with energy-saving bulbs could save you about $50 per year. For the greatest savings, replace your old incandescent bulbs with ENERGY STAR-qualified bulbs. An average household dedicates about 10% of its energy budget to lighting. Switching to energy-efficient lighting is one of the fastest ways to cut your energy bills. Timers and motion sensors save you even more money by reducing the amount of time lights are on but not being used.

456

Taunton Municipal Lighting Plant - Residential and Non-Profit  

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

Taunton Municipal Lighting Plant - Residential and Non-Profit Taunton Municipal Lighting Plant - Residential and Non-Profit Weatherization Program (Massachusetts) Taunton Municipal Lighting Plant - Residential and Non-Profit Weatherization Program (Massachusetts) < Back Eligibility Nonprofit Residential Savings Category Home Weatherization Commercial Weatherization Sealing Your Home Ventilation Manufacturing Maximum Rebate General: $500 Each customer will be eligible for one rebate per the three year project window. Program Info Start Date 1/1/2012 Expiration Date 12/31/2012 State Massachusetts Program Type Utility Rebate Program Rebate Amount Up to 50% of total cost: Attic insulation Wall insulation Rim joist insulation Air-sealing measures Window treatments Pipe/duct insulation Provider Customer Care Taunton Municipal Lighting Plant (TMLP) offers the 'House N Home' Thermal

457

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

458

Carbon Power and Light - Residential and Commercial Energy Efficiency  

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

Carbon Power and Light - Residential and Commercial Energy Carbon Power and Light - Residential and Commercial Energy Efficiency Rebate Program Carbon Power and Light - Residential and Commercial Energy Efficiency Rebate Program < Back Eligibility Commercial Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heat Pumps Manufacturing Appliances & Electronics Water Heating Maximum Rebate Water Heater: $75 Program Info State Wyoming Program Type Utility Rebate Program Rebate Amount Water Heater: $1.50 - $3 /gallon, plus $50 Tri-State G&T incentive Resistive Heat: $8 /kW Electric Thermal Storage: $50 /unit or $12 /kW Air-Source Heat Pump: $125 - $150 /ton Geothermal Heat Pump: $150 /ton Terminal Unit: $85 Motors: $8 - $13 /hp (CPL and Tri-State Combined Rebate) Provider Carbon Power and Light, Inc.

459

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect

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

460

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

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

Tokyo Street Lights  

E-Print Network (OSTI)

that you have only 17, no 16, no 15 seconds left to get to the other side before the light changes and the impatient American drivers put the pedal to the metal and it's road kill time. Talk about stress! In Tokyo, crossing the street is a leisurely...

Hacker, Randi; Tsutsui, William

2008-03-12T23:59:59.000Z

462

Radioluminescent polymer lights  

SciTech Connect

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

463

Environmental Preferences LIGHT: Sunny.  

E-Print Network (OSTI)

Environmental Preferences LIGHT: Sunny. SOIL: Well-drained, deep sandy loam. FERTILITY: Medium beans BeansDiane Relf, Extension Specialist, Horticulture, Virginia Tech Alan McDaniel, Extension Specialist, Horticulture, Virginia Tech are yellow and waxy in appearance, their flavor is only subtly

Liskiewicz, Maciej

464

Studies in Light Production  

Science Journals Connector (OSTI)

... interested in that subject. The collection consists of ten chapters which have appeared in The Electrician, together with two others. It may at once be said that the contents are ... contents are not only extremely interesting, but will also serve as a useful and important handbook for lighting engineers. ...

1912-12-26T23:59:59.000Z

465

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

466

Scattering Solar Thermal Concentrators  

Energy.gov (U.S. Department of Energy (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."

467

Thermal ignition combustion system  

SciTech Connect

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.degree. C. and a specific heat greater than 480 J/kg.degree. 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.

Kamo, Roy (Columbus, IN); Kakwani, Ramesh M. (Columbus, IN); Valdmanis, Edgars (Columbus, IN); Woods, Melvins E. (Columbus, IN)

1988-01-01T23:59:59.000Z

468

Thermal ignition combustion system  

SciTech Connect

A thermal ignition combustion system adapted for use with an internal combustion engine is described comprising: (a) means for providing ignition chamber walls defining an ignition chamber, the chamber walls being made of a material having a thermal conductivity greater than 20 W/m/sup 0/C. and a specific heat greater than 480J/kg/sup 0/C., the ignition chamber being in constant communication with the main combustion chamber; (b) means for maintaining the temperature of the chamber walls above a threshold temperature capable of causing ignition of a fuel; and (c) means for conducting fuel to the ignition chamber.

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

1988-04-19T23:59:59.000Z

469

Thermal test options  

SciTech Connect

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

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

1993-02-01T23:59:59.000Z

470

Experimental Study of Thermal Performance and the Contribution of Plant-Covered Walls to the Thermal Behavior of Building  

Science Journals Connector (OSTI)

Abstract This paper presented on experimental investigation of the influence of plant-covered wall on the thermal behavior of buildings in the semi-arid regions during the summer period. Thermal performance of a green walls system on facade walls has been experimentally investigated in a test room. The test cell dimensions are 1x1.2x0.8 m. In this study the thermal analysis concerns two test cells that incorporate non-covered and covered with two types of plants (Jasmine and Aristolochia). A Light source is used to simulate solar radiation. The results showed that plant cover improved indoor thermal comfort in both summer, and reduced heat gains and losses through the wall structure. It is verified that a microclimate between the wall of the test cell and the green wall is created, and it is characterized by slightly lower temperatures and higher relative humidity.

Saifi Nadia; Settou Noureddine; Necib Hichem; Damene Djamila

2013-01-01T23:59:59.000Z

471

Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus  

SciTech Connect

Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

Harel, Elad [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

2012-05-07T23:59:59.000Z

472

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

E-Print Network (OSTI)

ENERGY STORAGE FOR CONCENTRATING SOLAR POWER PLANTS,”Thermal Energy Storage in Concentrated Solar Thermal PowerThermal Energy Storage in Concentrated Solar Thermal Power

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

473

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

E-Print Network (OSTI)

CHANGE THERMAL ENERGY STORAGE FOR CONCENTRATING SOLAR POWERfor Thermal Energy Storage in Concentrated Solar Thermalfor Thermal Energy Storage in Concentrated Solar Thermal

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

474

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

E-Print Network (OSTI)

and Background Solar thermal energy collection is anCHANGE THERMAL ENERGY STORAGE FOR CONCENTRATING SOLAR POWERfor Thermal Energy Storage in Concentrated Solar Thermal

Hardin, Corey Lee

2011-01-01T23:59:59.000Z

475

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

476

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

477

Thermal Reactor Safety  

SciTech Connect

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

478

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

479

Embodied Energy and Off-Grid Lighting  

E-Print Network (OSTI)

solar and wind energy systems. 7 If anticipated improvements in LED lighting system performance (Lighting Africa,

Alstone, Peter

2012-01-01T23:59:59.000Z

480

Incandescent Lighting | Department of Energy  

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

Incandescent Lighting Incandescent Lighting Incandescent Lighting October 17, 2013 - 6:15pm Addthis Incandescent lighting is the most common, and least energy efficient, type of lighting used in homes. | Photo courtesy of ©iStockphoto/TokenPhoto. Incandescent lighting is the most common, and least energy efficient, type of lighting used in homes. | Photo courtesy of ©iStockphoto/TokenPhoto. Incandescent lamps are often considered the least energy efficient type of electric lighting commonly found in residential buildings. Although inefficient, incandescent lamps possess a number of key advantages--they are inexpensive to buy, turn on instantly, are available in a huge array of sizes and shapes and provide a pleasant, warm light with excellent color rendition. However, because of their relative inefficiency and short life spans, they

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.


481

Incandescent Lighting | Department of Energy  

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

Incandescent Lighting Incandescent Lighting Incandescent Lighting October 17, 2013 - 6:15pm Addthis Incandescent lighting is the most common, and least energy efficient, type of lighting used in homes. | Photo courtesy of ©iStockphoto/TokenPhoto. Incandescent lighting is the most common, and least energy efficient, type of lighting used in homes. | Photo courtesy of ©iStockphoto/TokenPhoto. Incandescent lamps are often considered the least energy efficient type of electric lighting commonly found in residential buildings. Although inefficient, incandescent lamps possess a number of key advantages--they are inexpensive to buy, turn on instantly, are available in a huge array of sizes and shapes and provide a pleasant, warm light with excellent color rendition. However, because of their relative inefficiency and short life spans, they

482

Fluorescent Lighting | Department of Energy  

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

Fluorescent Lighting Fluorescent Lighting Fluorescent Lighting October 17, 2013 - 5:44pm Addthis Fluorescent Lighting Fluorescent Lighting Fluorescent lamps use 25%-35% of the energy used by incandescent products to provide a similar amount of light. They also last about 10 times longer (7,000-24,000 hours). The two general types of fluorescent lamps are: Compact fluorescent lamps (CFLs) -- commonly found with integral ballasts and screw bases, these are popular lamps often used in household fixtures Fluorescent tube and circline lamps -- typically used for task lighting such as garages and under cabinet fixtures, and for lighting large areas in commercial buildings. CFLs CFLs combine the energy efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures. CFLs fit most fixtures

483

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

484

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

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

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...

485

Impact of Ageing on Thermal Efficiency of Solar Thermal Collectors  

Science Journals Connector (OSTI)

Today it is common practice to calculate the performance of solar thermal systems or solar collectors based on the results of a thermal performance test carried out with a new solar collector. However, for an int...

Elke Streicher; Stephan Fischer…

2009-01-01T23:59:59.000Z

486

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

487

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

488

Using Phonon Resonances as a Route to All-Angle Negative Refraction in the Far-Infrared Region: The Case of Crystal Quartz  

Science Journals Connector (OSTI)

We consider how all-angle negative refraction may be induced in anisotropic crystals by making use of the phonon response. We investigate the example of crystal quartz at far-infrared wavelengths. Reflection and transmission measurements confirm the expected behavior, and show relatively high transmission efficiency at frequencies at which negative refraction occurs.

R. Rodrigues da Silva; R. Macêdo da Silva; T. Dumelow; J. A. P. da Costa; S. B. Honorato; A. P. Ayala

2010-10-12T23:59:59.000Z

489

Ab Initio Time-Domain Study of Phonon-Assisted Relaxation of Charge Carriers in a PbSe Quantum Dot  

E-Print Network (OSTI)

Ab Initio Time-Domain Study of Phonon-Assisted Relaxation of Charge Carriers in a PbSe Quantum Dot optical modes. Holes decay only slightly faster than electrons, rendering the hole-assisted Auger that was reported recently in relation to improved solar power conversion. 1. Introduction Nanometer-size crystals

490

Preliminary requirements for thermal storage subsystems in solar thermal applications  

SciTech Connect

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

491

Light with nonzero chemical potential  

Science Journals Connector (OSTI)

Thermodynamic states and processes involving light are discussed in which the chemical potential of light is nonzero. Light with nonzero chemical potential is produced in photochemical reactions for example in a light emitting diode. The chemical potential of black-body radiation becomes negative upon a Joule expansion. The isothermal diffusion of light which is a common phenomenon is driven by the gradient in the chemical potential. These and other examples support the idea that light can be interpreted as a gas of photons with properties similar to a material gas.

F. Herrmann; P. Würfel

2005-01-01T23:59:59.000Z

492

Lighting the Way with Compact Fluorescent Lighting | Department of Energy  

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

Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting April 28, 2009 - 5:00am Addthis John Lippert There is a major push today to get homeowners to adopt compact fluorescent lamp (CFL) light bulbs. They have been on the market for nearly three decades, and many homeowners still do not use them widely. But the tide is definitely turning. Their availability and the percentage of homeowners familiar with the technology and purchasing them for their homes have been steadily rising. The products have improved considerably compared to early products, and their prices have plummeted. The ENERGY STAR® Change a Light, Change the World Campaign has been running now for more than half a dozen years. This campaign is designed to

493

Types of Lighting in Commercial Buildings - Lighting Characteristics  

Annual Energy Outlook 2012 (EIA)

of Lighting Types Efficacy Efficacy is the amount of light produced per unit of energy consumed, expressed in lumens per watt (lmW). Lamps with a higher efficacy value are...

494

Lighting Designer Roundtable on Solid-State Lighting  

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

Roundtable meeting in Chicago of a group of lighting designers focused on examining solid-state lighting (SSL) market and technology issues and encouraging a discussion of designers’ experiences, ideas, and recommendations regarding SSL & SSL industry.

495

Lighting the Way with Compact Fluorescent Lighting | Department of Energy  

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

Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting Lighting the Way with Compact Fluorescent Lighting April 28, 2009 - 5:00am Addthis John Lippert There is a major push today to get homeowners to adopt compact fluorescent lamp (CFL) light bulbs. They have been on the market for nearly three decades, and many homeowners still do not use them widely. But the tide is definitely turning. Their availability and the percentage of homeowners familiar with the technology and purchasing them for their homes have been steadily rising. The products have improved considerably compared to early products, and their prices have plummeted. The ENERGY STAR® Change a Light, Change the World Campaign has been running now for more than half a dozen years. This campaign is designed to

496

National Synchrotron Light Source  

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

Report 2001 Report 2001 National Synchrotron Light Source For the period October 1, 2000 through September 30, 2001 Introduction Science Highlights Year in Review Operations Publications Abstracts Nancye Wright & Lydia Rogers The National Synchrotron Light Source Department is supported by the Office of Basic Energy Sciences United States Department of Energy Washington, D.C. Brookhaven National Laboratory Brookhaven Science Associates, Inc. Upton, New York 11973 Under Contract No. DE-AC02-98CH10886 Mary Anne Corwin Steven N. Ehrlich & Lisa M. Miller Managing Editor Science Editors Production Assistants Cover images (clockwise from top left) 1. from Science Highlight by K.R. Rajashankar, M.R. Chance, S.K. Burley, J. Jiang, S.C. Almo, A. Bresnick, T. Dodatko, R. Huang, G. He,

497

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

498

OLEDS FOR GENERAL LIGHTING  

SciTech Connect

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