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Creator | Title | Description | Subject | Date |
| 26 |
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Lupton, John Mark | Device model for polymer light emitting diodes: effect of temperature and oxidation | We present a temperature-dependent single carrier device model for polymer light-emitting diodes. The model includes both the injection of charge carriers over a barrier and the transport of charges across the device. To test the model, the temperature dependence of an LED based on the conjugated po... | Single carrier; Temperature dependent; Poly(phenylene vinylene); Transport measurements; ITO; Disorder | 1999 |
| 27 |
 |
Vardeny, Zeev Valentine; Raikh, Mikhail E. | Excitations in opal photonic crystals infiltrated with polarizable media | Photonic crystals (PC) are a class of artificial structures with a periodic dielectric function. PCs can be a laboratory for testing fundamental processes involving interactions of radiation with matter in novel conditions. We have studied the optical properties of opal PCs that are infiltrated with... | Opal photonic crystals; Polarizable media; Bragg gap; Polaritonic gap; Photonic stop band | 2002 |
| 28 |
 |
Vardeny, Zeev Valentine | Optical probes of photoexcitations in fullerene thin films from femtoseconds to milliseconds | We have studied photoexcitations in various fiillerene thin films using transient photomodulation and photoluminescence from 100 fs to 50 ms and absorption-detected magnetic resonance (ADMR). We show that singlet Frenkel type excitons are the primary photoexcitations; their recombination kinetics in... | Photoexcitations; Femtosecond; Transient photomodulation; Transient photoluminescence; Frenkel type excitons; Triplet excitons | 1995 |
| 29 |
 |
Vardeny, Zeev Valentine | Picosecond photomodulation spectroscopy in amorphous semiconductors | Picosecond trapping of photogenerated carriers in gap states of doped, compensated and undoped amorphous hydrogenated silicon (a-Si:H) and of a-Si:H based superlattices was studied by the pump and probe photomodulation technique. In undoped a-Si:H the photogenerated carries are trapped in band-tail ... | Picosecond spectroscopy | 1987 |
| 30 |
 |
Vardeny, Zeev Valentine; Gellermann, Werner | Two-photon absorption spectra of luminescent conducting polymers measured over a wide spectral range | We report the two-photon absorption (TPA) spectra of poly(2,5-dibutoxy-p-phenylene acetylene) (PPADBO), poly(2,5-dioctyloxy-p-phenylene vinylene) (PPV-DOO), and poly(3-hexylthiophene) (PAT6) in the spectral range extending from 576 nm to 846 nm. Using the Z-scan technique on the polymers in solutio... | Two-photon absorption; Two-photon saturation; Luminescent polymers; Dispersion; Polymer solution; PPA-DBO | 1997 |
| 31 |
 |
Sekercioglu, Cagan | The need to quantify ecosystem services provided by birds | What are birds worth-what is their actual dollar value to human society? To most of us in the ornithological community, birds are invaluable. But in these times we need more specific rationales to convince policy makers and business leaders to include bird conservation in land-use and development de... | | 2011-01-01 |
| 32 |
 |
Vardeny, Zeev Valentine | Laser action in conducting polymers | We discuss both cooperative radiation and stimulated emission and consider their role in spectral narrowing of luminescent conducting polymers. We argue that cooperative radiation is favored in films with poor optical confinement. On the other hand, directional stimulated emission can be observed in... | Laser action; Cooperative radiation; Stimulated emission; PPV; Disubstituted polyacetylene; Excitons; Spectral narrowing; Plastic lasers; Superfluorescence; Microcavity lasers | 1997 |
| 33 |
 |
Vardeny, Zeev Valentine | Photoresponse and electroresponse of polymers light emitting diodes | We have studied the photoresponse and electroresponse of light emitting diodes (LEDs ) made from a variety of soluble conducting polymers sandwiched between indium tin oxide (ITO) and metals including calcium, aluminum and copper. Under illumination all freshly prepared LEDs exhibit relatively large... | Photoresponse; Electroresponse; Photovoltage; I-V curves | 1995 |
| 34 |
 |
Vardeny, Zeev Valentine | Spin and spectral signatures of polaron pairs in π-conjugated polymers | We have studied polaron pair photoexcitations in a variety of π-conjugated polymer films by photoinduced absorption (PA) and optically-detected magnetic resonance (ODMR). An exchange interaction between polarons broadens the ODMR spectrum, permitting the unambiguous identification of the polaron pa... | Polaron pair; ODMR; Photoinduced absorption; Spin signatures; Spectral signatures; pi-conjugated polymers | 1997 |
| 35 |
 |
Armentrout, Peter B. | Transition metal cluster ion chemistry | The reactivity and thermochemistry of ionic metal atoms and clusters has been explored using guided ion beam mass spectrometry. With this apparatus, cross sections of ion-molecule reactions can be measured from thermal energies to hundreds of eV. Application to metal cluster chemistry demonstrates... | Metal clusters; Manganese ions; Endothermic reactions | 1986 |
| 36 |
 |
Armentrout, Peter B. | Methane activation by cobalt cluster cations, Con+ (n=2-16): reaction mechanisms and thermochemistry of cluster-CHx (x=0-3) complexes | The kinetic energy dependences of the reactions of Con + (n=2-16) with CD4 are studied in a guided ion beam tandem mass spectrometer over the energy range of 0-10 eV. The main products are hydride formation, ConD+, dehydrogenation to form ConCD2 +, and double dehydrogenation yielding ConC+. | Cobalt ions; Transition metal ions; Bond energies; Endothermic reactions; Dehydrogenation; Deuterated methane | 2009 |
| 37 |
 |
Vardeny, Zeev Valentine; Raikh, Mikhail E. | Cooperative emission from a disordered system: a classical model | The effect of disorder on the collective emission from a system of classical oscillators is studied theoretically. Three types of disorder are considered: random orientation of dipole moments, finite spread in frequencies of the individual oscillators (diagonal disorder), and dipole-dipole interacti... | Cooperative emission; Disordered system; Dipole-dipole interaction; Oscillators | 1997 |
| 38 |
 |
Sokolsky, Pierre | High Resolution Fly's Eye - status and preliminary results on cosmic ray composition above 10^18 eV | We describe the current status of the High Resolution Fly's Eye detector. Event reconstruction and associated systematics for stereo reconstruction are discussed and recent preliminary results on the study of the composition of ultra-high energy cosmic rays by the Xmax method are presented. These r... | Ultra-high energy cosmic rays; Fluorescence; Stereo detection | 2002 |
| 39 |
 |
Vardeny, Zeev Valentine | Photoexcitations in disubstituted acetylene polymers | We have used a variety of optical techniques to study the photoexcitations dynamics in several disubstituted acetylene polymer thin films. We found that although these polymers have a degenerate ground state, as determined by iodine doping and C6Q photodoping, they show strong photoluminescence (PL)... | Photoexcitations; Disubstituted acetylene polymers; Trans-Polyacetylene; Electron-electron interactions | 1997 |
| 40 |
 |
Vardeny, Zeev Valentine; Gellermann, Werner | Two-photon absorption measured in the presence of strong one-photon saturation in cumulene-containing polymer | The Z-scan technique is used to extract the real and imaginary third order nonlinear susceptibilities, Rex(3) and Imx(3), respectively. A series of Z scans were conducted at 590 nm (near one-photon resonance) on a cumulene-containing polymer, poly(p-phenylene-l,4-diphenyl-l,2,3-butatriene) or PPC3, ... | Molecular second hyperpolarizability; One-photon saturation; Polymer solution; Chain length | 1997 |
| 41 |
 |
Ailion, David Charles; Morris, Alan H. | Asymmetric spin echo sequences. a simple new method for obtaining NMR 1H spectral images | The nuclear magnetic resonance (NMR) signal decay produced by reversible tissue-induced dephasing of the magnetization components in the transverse plane (reversible tissue-induced dephasing) was measured and expressed as a function of a new transverse relaxation time T'2 (T2 prime) for samples of ... | Asymmetric spin echo; Signal decay; Chemical shift; Tissue characterization; Lung aeration; Fatty liver | 1985 |
| 42 |
 |
Dawson, Kyle | CCD testing and characterization for dark energy survey | A description of the plans and infrastructure developed for CCD testing and characterization for the DES focal plane detectors is presented. Examples of the results obtained are shown and discussed in the context of the device requirements for the survey instrument. | DES | 2006 |
| 43 |
 |
Kieda, David B. | Science capabilities of the VERITAS array of 10m imaging atmospheric Cherenkov gamma-ray detectors | The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an array of seven 10m aperture telescopes used for gamma-ray astronomy in the 50 GeV to 50 TeV (1 TeV= 101 2 electron Volt) energy range. The gamma rays are detected by measuring the optical Cherenkov light emitted by the casc... | VERITAS | 2003 |
| 44 |
 |
Vardeny, Zeev Valentine | Specific heats and lattice dynamics of cuprous halides | The specific heats Cp(T) of CuCl, CuBr, and Cul were measured by the adiabatic calorimetric technique. The corresponding Debye temperature for each crystal is given and a comparison between the results is drawn. The room-temperature phonon dispersion relations for these cystals are fitted by a nine... | Cuprous halides; CuBr; CuCl; CuI | 1978-10 |
| 45 |
 |
Vardeny, Zeev Valentine; Nahata, Ajay | Thermal emission from metallic films perforated with subwavelength hole arrays | This report presents an overview of our study on the optical transmission and thermal light emission properties of subwavelength hole arrays fabricated in a square lattice with 4 um periodicity. The structures were fabricated in thin aluminum (Al) films on silicon (Si) substrates using conventional ... | | 2008 |
| 46 |
 |
Vardeny, Zeev Valentine | Ultrafast spectroscopy of excitons in semiconducting carbon nanotubes | Ultrafast relaxation dynamics of photoexcitations in semiconducting single walled carbon nanotubes (S-NTs) were investigated using polarized pump-probe photomodulation (with 150 fs time resolution) and cw polarized photoluminescence (PL). Both annealed and unannealed NT films and D 2 0 solutions of ... | Non-linear optical methods; Carbon nanotubes; ultrafast dynamics | 2005 |
| 47 |
 |
Vardeny, Zeev Valentine; Raikh, Mikhail E. | Coherent random lasing: trapping of light by the disorder | Recent discovery of the coherent lasing from various disordered materials adds a new dimension to the conventional physics of light propagation in multiply scattering media. It suggests that in the situation, when the propagation of light is diffusive on average, the coherent feedback can be provid... | Coherent random lasing; Coherent lasing; Disorder; Disordered materials; Random lasers; Random resonators; Power Fourier transform; Light propagation | 2004 |
| 48 |
 |
Golden, Kenneth M. | Critical behavior of transport in percolation-controlled smart composites | The electrical transport properties of many smart composites and other technologically important materials are dominated by the connectedness, or percolation properties of a particular component. Predicting the critical behavior of such media near their percolation threshold, where one typically obt... | Matrix-particle composites | 1997 |
| 49 |
 |
Kieda, David B. | Toward a revival of stellar intensity interferometry | Building on technological developments over the last 35 years, intensity interferometry now appears a feasible option by which to achieve diffraction-limited imaging over a square-kilometer synthetic aperture. Upcoming Atmospheric Cherenkov Telescope projects will consist of up to 100 telescopes, ... | Intensity interferometry; Air Cherenkov Telescope | 2008 |
| 50 |
 |
Kieda, David B. | Overview of the ANITA project | The ANITA project is designed to investigate ultra-high energy (>1017 eV) cosmic ray interactions throughout the universe by detecting the neutrinos created in those interactions. These high energy neutrinos are detectable through their interactions within the Antarctic ice sheet, which ANITA will u... | ANITA; Antarctic Impulsive Transient Antenna; High energy neutrinos; Antarctica; Balloon | 2003 |
