Filters: Collection:"ir_uspace"
| Creator | Title | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 176 |  | Gerton, Jordan | Laser-free slow atom source | A slow atom source, which does not rely on lasers, has been developed and characterized. The device, acting as an atomic low-pass velocity filter, utilizes permanent magnets to passively select the slow atoms present in a thermal atomic beam. Slow atoms are guided along a curved, conduction-limite... | 1999-11 | |
| 177 |  | Wu, Yong-Shi | Matrix compactification on orientifolds | Generalizing previous results for orbifolds, in this paper we describe the compactification of the matrix model on an orientifold which is a quotient space Rd/G as a Yang-Mills theory residing on a quantum space. The information of the compactification is encoded in the action of the discrete symmet... | Spacetime; Orientifolds; Compactification; Quantum space | 1999-06 |
| 178 |  | Gerton, Jordan | Measurements of collective collapse in a Bose-Einstein condensate with attractive interactions | The occupation number of a magnetically trapped Bose-Einstein condensate is limited for atoms with attractive interactions. It has been predicted that, as this limit is approached, the condensate will collapse by a collective process. The measured spread in condensate number for samples of 7Li atom... | 1999-02 | |
| 179 |  | Wu, Yong-Shi | Near-horizon Virasoro symmetry and the entropy of de Sitter space in any dimension | De Sitter spacetime is known to have a cosmological horizon that enjoys thermodynamic-like properties similar to those of a black hole horizon. In this note we show that a universal argument can be given for the entropy of de Sitter spacetime in arbitrary dimensions, by generalizing a recent near ho... | 1999-05 | |
| 180 |  | Vardeny, Zeev Valentine | Optical studies of triplet excitations in poly(p-phenylene vinylene) | We have studied energy states in the triplet manifold in films of poly(p-phenylene vinylene) (PPV) using a multitude of optical spectroscopies including photoinduced absorption, photoluminescence, their optically detected magnetic resonances, as well as their photogeneration action spectra. We foun... | Triplet excitations; PPV | 1999-10 |
| 181 |  | Capecchi, Mario R. | Paralogous mouse Hox genes, Hoxa9, Hoxb9, and Hoxd9, function together to control development of the mammary gland in response to pregnancy. | Although the role of Hox genes in patterning the mammalian body plan has been studied extensively during embryonic and fetal development, relatively little is known concerning Hox gene function in adult animals. Analysis of mice with mutant Hoxa9, Hoxb9, and Hoxd9 genes shows that these paralogous g... | Embryonic and Fetal Development; Gene Expression Regulation, Developmental; Genotype; Mice, Knockout | 1999-01 |
| 182 |  | Vardeny, Zeev Valentine | Photogeneration action spectroscopy of neutral and charged excitations in films of ladder-type poly(para-phenylene) | The photogeneration quantum efficiency action spectra of long-lived neutral and charged excitations in films of a ladder-type poly(para-phenylene) were measured. We found that both triplet and polaron action spectra show, in addition to a step function increase at the optical gap, a monotonic rise a... | Photogeneration; Neutral excitations; Charged excitations; pi-conjugated polymers; Transient spectroscopy | 1999-04 |
| 183 |  | Vardeny, Zeev Valentine | Photogeneration and recombination processes of neutral and charged excitations in films of a ladder-type poly(para-phenylene) | We introduce a version of the cw photomodulation technique, measured far from the steady state, for obtaining the quantum efficiency, η, of long-lived photoexcitations in p-conjugated polymers. We apply this technique to films of a ladder-type poly(para-phenylene) [mLPPP] for studying the photoge... | Photogeneration; Recombination process; Neutral excitations; Charged excitations; Ladder-type poly(para-phenylene) | 1999-08 |
| 184 |  | Mishchenko, Eugene | Radiative transfer theory for vacuum fluctuations | A semiclassical kinetic theory is presented for the fluctuating photon flux emitted by a disordered medium in thermal equilibrium. The kinetic equation is the optical analog of the Boltzmann-Langevin equation for electrons. Vacuum fluctuations of the electromagnetic field provide a new source of flu... | Vacuum fluctuations | 1999-12 |
| 185 |  | Mishchenko, Eugene | Raman scattering in a two-dimensional electron gas: Boltzmann equation approach | The inelastic light scattering in a two-dimensional electron gas is studied theoretically using the Boltzmann equation techniques. Electron-hole excitations produce the Raman spectrum essentially different from the one predicted for the 3D case. In the clean limit it has the form of a strong nonsy... | Raman scattering; Boltzmann equation | 1999-06 |
| 186 |  | Research in brief: Spring 1999 | Summaries of Selected Research Projects at the University of Utah Health Sciences Center | Research: School of Medicine, College of Pharmacy;, College of Nursing, College of Health | 1999-09 | |
| 187 |  | Liu, Feng | Self-organized replication of 3D coherent island size and shape in multilayer heteroepitaxial films | A model is proposed to elucidate the evolution of the morphology of strained 3D islands in multilayer heteroepitaxial films. The model explains the experimental observation that islands grown in successive layers not only replicate, forming individual island columns, but self-organize to reach a com... | Coherent island size; Island shape; Heteroepitaxial films; Strained 3D islands; Heteroepitaxial films | 1999-03 |
| 188 |  | Liu, Feng | Step-induced optical anisotropy of vicinal Si(001) | It is demonstrated, using reflectance difference spectroscopy, scanning tunneling microscopy, and low-energy electron diffraction, combined with deliberate straining of the surface, that the presence of atomic steps dramatically changes the optical anisotropy of the Si(001) surface. The step-induce... | Step-induced; Optical anisotropy; Vicinal Si(001); Electron diffraction; Atomic steps | 1999-01 |
| 189 |  | Vardeny, Zeev Valentine | Stimulated emission in high-gain organic media | Stimulated emission was studied in various scattering gain media, including thin p-conjugated polymer films, organic dyes-doped gel films, and opal crystals saturated with polymer and laser dye solutions. We found that at high excitation intensities a featureless amplified spontaneous emission ban... | Stimulated emission; High-gain organic media; pi-conjugated polymers; Scattering gain media; Organic dyes-doped gel films; Opal crystals | 1999-02 |
| 190 |  | DeTar, Carleton | String breaking in lattice QCD | The separation of a heavy quark and antiquark pair leads to the formation of a tube of flux, or string, which should break in the presence of light quark-antiquark pairs. This expected zero temperature phenomenon has proven elusive in simulations of lattice QCD. We present simulation results that ... | String breaking; Flux tube; Staggered quarks; Wilson loop; Polyakov loop | 1999-03 |
| 191 |  | Mattis, Daniel C. | Three-band model of high-Tc superconductivity | We reduce the three-band model of planar CuO2 to a single-band of composite fermions. We obtain hopping parameters teff(Rij), repulsive potentials Ueff and V(Ri j), and the superexchange interactions J(Ri j) necessary for both antiferromagnetism and superconductivity. The ratios of these quantitie... | Copper oxides; Composite fermions; Charge transport; Bloch energies; Superexchange | 1999-03 |
| 192 |  | Thalos, Mariam G. | Units of decision | I shall introduce the units of decision problem in the theory of decision, which as I shall explain is a sibling to the units of selection problem in evolutionary theory. And I shall present an argument to the effect that, contrary to Bayesian wisdom on the subject, undertaking decision in group set... | Decision theory; Collective will; Cooperation; Individualism | 1999-09 |
| 193 |  | Blumenthal, Donald K.; Underwood, Clayton J. | Adaptation of the protein kinase filter paper assay to a 96-well microtiter format. | The most widely used method for assaying protein kinase activities involves incorporation of radioactive phosphate into a protein or peptide substrate with subsequent binding or precipitaion of the radiolabeled substrate onto filter paper squares. We have adapted this assay for use with readily avai... | Protein Kinase Activities; Filter Papers; Radioactive Phosphate | 1999-02-01 |
| 194 |  | Harrison, Reid R. | Analog VLSI implementation of a visual interneuron: enhanced sensory processing through biophysical modeling | Flies are capable of rapid, coordinated flight through unstructured environments. This flight is guided by visual motion information that is extracted from photoreceptors in a robust manner. One feature of the fly's visual processing that adds to this robustness is the saturation of wide-fi_x000... | 1999-01-01 | |
| 195 |  | Stringfellow, Gerald B. | Bandgap control of GaInP using Sb as a surfactant | The use of surfactants to control specific aspects of the vapor-phase epitaxial growth process is beginning to be studied for both the elemental and III/V semiconductors. To date, most reported surfactant effects for semiconductors relate to the morphology of the growing films. However, semicondu... | Band-gap energy; Growth process; Epitaxial growth | 1999-09-27 |
| 196 |  | Regehr, John | CPU reservations and time constraints: implementation experience on windows NT | This paper presents an implementation of scheduling abstractions originally developed for the Rialto real-time operating system within a research version of Windows NT called Rialto/NT. These abstractions, CPU Reservations and Time Constraints, as described in the 1997 SOSP paper [Jones et al. 97], ... | 1999-01-01 | |
| 197 |  | Nichols, Shaun | Explicit factuality and comparative evidence. | We argue that Dienes & Perner's (D&P's) proposal needs to specify independent criteria when a subject explicitly represents factuality. This task is complicated by the fact that people typically "tacitly" believe that each of their beliefs is a fact. This problem does not arise for comparative evide... | Philosophy;; Factuality; Dienes & Perner's Proposal | 1999-12-16 |
| 198 |  | Harrison, Reid R. | Floating gate current mirror for gain correction in CMOS translinear circuits | The exponential behavior of MOSFETs in subthreshold operation has recently been exploited to build CMOS translinear circuits such as multipliers and log-domain filters. A major obstacle in developing a practical CMOS implementation is the variation in threshold voltage between devices. In transline... | 1999-01-01 | |
| 199 |  | Ehleringer, James R. | Grupos funcionales en arbustos deserticos del norte de Chile, definidos sobre la base de las fuentes de agua utilizadas | La productividad primaria y la estructura de la vegetación en ecosistemas áridos están determinadas por la disponibilidad de agua. En un estudio realizado en el secano costero del norte-centro de Chile (29/43'S; 71/14'O, 300 m) se compararon los mecanismos de utilización de distintas fuentes de... | Grupos funcionales; Functional groups; Arbustos deserticos; Desert shrubs; Fuentes de agua; Water sources; Water availability; Arid ecosystems; Pastoreo con caprinos; Goat overgrazing | 1999-01-01 |
| 200 |  | Regehr, John | Hierarchical schedulers, performance guarantees, and resource management | An attractive approach to scheduling applications with diverse CPU scheduling requirements is to use different schedulers for different applications. For example: real-time schedulers allow applications to perform computations before deadlines, time-sharing schedulers provide high throughput for com... | 1999-01-01 |