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Creator | Title | Description | Subject | Date |
| 376 |
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Gondolo, Paolo | Limits on R-parity violation from cosmic ray antiprotons | We constrain the hadronic R-parity violating couplings in extensions to the minimal supersymmetric standard model. These interactions violate baryon and lepton number, and allow the lightest superpartner (LSP) to decay into standard model particles. The observed flux of cosmic ray antiprotons plac... | R-parity; Supersymmetric models | 1998-06 |
| 377 |
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Sokolsky, Pierre; Cassiday, George L. | Limits on deeply penetrating particles in the >10^17 eV cosmic-ray flux | We report on a search for deeply penetrating particles in the > 10^17 eV cosmic-ray flux using the University of Utah Fly's Eye detector. No such events have been found in 6 x 106 sec of running time. We consequently set limits on the following: quark matter in the primary cosmic-ray flux, high-ener... | | 1985-05 |
| 378 |
 |
Kieda, David B. | Limits on the isotropic diffuse flux of ultrahigh energy gamma radiation | Diffuse ultrahigh energy g radiation can arise from a variety of astrophysical sources, including the interaction of 1020 eV cosmic rays with the 2.7 K microwave background radiation or the collapse of topological defects created in the early Universe. We describe a sensitive search for diffuse g ... | G rays; Ultrahigh energy; Muons; Cosmic rays | 1997 |
| 379 |
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Vardeny, Zeev Valentine | Linear and nonlinear optical spectroscopies of PPV/PPE copolymer semiconductors | We used a variety of picosecond transient and cw spectroscopies to investigate the linear and nonlinear optical properties of films of PPE/PPV copolymer semiconductor. The spectroscopies used include absorption, electroabsorption (EA) and two-photon-absorption (TPA). In addition to the odd parity e... | Linear optical spectroscopy; Nonlinear optical spectroscopy; PPV/PPE copolymer; pi-conjugated polymers | 2005 |
| 380 |
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Vardeny, Zeev Valentine; Ehrenfreund, Eitan A. | Linear and nonlinear photoexcitation dynamics in ∏-conjugated polymers | Linear and nonlinear recombination kinetics with various lifetime distributions were identified for long-lived photoexcitations in a series of rr-conjugated polymer films using modulation frequency and excitation intensity dependencies of the photoinduced absorption. This includes monomolecular, bim... | Linear photoexcitation; Nonlinear photoexcitation; pi-conjugated polymers; Recombination kinetics | 2003-01 |
| 381 |
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Lupton, John Mark | Linewidth-limited energy transfer in single conjugated polymer molecules | Using low temperature single molecule spectroscopy on rigid-rod conjugated polymers we are able to identify homogeneously broadened, strongly polarized emission from individual chromophore units on a single chain. Gated fluorescence spectroscopy allows real time imaging of intramolecular energy tran... | Linewidth-limited; Energy transfer; Rigid-rod; Single molecule spectroscopy; Gated fluorescence spectroscopy; Chromophores; Intramolecular energy transfer; Spectral linewidth | 2003-12 |
| 382 |
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Saam, Brian; Laicher, Gernot | Liquid hyperpolarized 129Xe produced by phase exchange in a convection cell | We present a method for the production of liquid hyperpolarized 129Xe that employs spin-exchange optical pumping in the gas phase and subsequent phase exchange with a column of xenon liquid. A convection loop inside the sealed glass cell allows efficient transfer of magnetization between the gas an... | Liquid hyperpolarized 129Xe; Phase exchange; Spin-exchange optical pumping; SEOP; NMR; Spin polarization | 2004 |
| 383 |
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DeTar, C. | Locality of the fourth root of staggard fermion determinant in the interacting case | The fourth root approximation in LQCD simulations with dynamical staggered fermions requires justification. We test its validity numerically in the interacting theory in a renormalization group framework. | Physics; Renormalization | 2005-09-29 |
| 384 |
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Mattis, Daniel C. | Localized magnetic moments in dilute metallic alloys: correlation effects | We discuss qualitatively the importance of the correlation energy in determining the ground state of a metal with an impurity atom. For a single, partly occupied impurity Estate orbital, the correlation energy acts to prevent the appearance of a nonvanishing ground-state spin, so that this simple no... | Magnetic moments; Metallic alloys; Correlation energy; Magnetic impurities; Orbital degeneracy | 1965-11 |
| 385 |
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Boehme, Christoph | Long-lived spin coherence in silicon with an electrical spin trap readout | Pulsed electrically detected magnetic resonance of phosphorous (31P) in bulk crystalline silicon at very high magnetic fields (B0 > 8:5 T) and low temperatures (T = 2:8 K) is presented. We find that the spin-dependent capture and reemission of highly polarized (>95%) conduction electrons by equall... | Spin coherence | 2008-11 |
| 386 |
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Mattis, Daniel C. | Long-ranged magnetic polarization effects | Two years ago a group1 at Bell Telephone Laboratories discovered an exceedingly long-ranged magnetic interaction among rare earth (RE) atoms dissolved in palladium. It is the purpose of the present note to suggest a theory for this phenomenon, which, it will be recalled, could not be explained by t... | Indirect exchange theory | 1964-05 |
| 387 |
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Ailion, David Charles | Low cost high linearity solid state digital double boxcar | In this article, we describe a digital solid state double boxcar of infinite holding time and very high linearity. It uses a Hewlett-Packard (HP2212 A-M3) voltage-to-frequency converter (VFC) whose output is accumulated on a running counter, thereby providing signal averaging with an infinite holdin... | High linearity; Boxcar; Instruments, Physics | 1969 |
| 388 |
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Ailion, David Charles | Low cost integrated circuit versatile pulse and frequency counter | In this paper we describe a compact multipurpose counter whose design is based on the use of plastic integrated circuits. The circuit contains about $90 worth of semiconductor components and is very easy to wire; nevertheless, it is extremely versatile. It consists of dual 107 and 106 counters which... | Integrated circuits; Counters; Physics instruments | 1969 |
| 389 |
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Saam, Brian | Low-field orientation dependence of 3He relaxation in spin-exchange cells | We have observed a significant dependence of 3He longitudinal relaxation times in glass spin-exchange optical pumping (SEOP) cells due only to the physical orientation of the cell in a 3 mT (30 G) applied magnetic field. The cells had no previous exposure to higher fields or were thoroughly degau... | Spin-exchange optical pumping; SEOP; 3He; Hyperpolarized noble gases; Longitudinal spin-relaxation; MEOP; Low-field orientation | 2004-02 |
| 390 |
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Ailion, David Charles | Low-field relaxation and the study of ultraslow atomic motions by magnetic resonance | Conventional resonance enables one to study motion of atoms by measurement of line width when the mean time r between jumps is less than 1/Aco, where Aa> is the rigid lattice line width, or by measurement of the spin-lattice relaxation time, Ti, when r ^ l / coo , where coo is the Larmor frequency. ... | Ultraslow atomic motion; Magnetic resonance | 1964 |
| 391 |
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Lupton, John Mark | Low-threshold polymeric distributed feedback lasers with metallic contacts | Optical losses in waveguides comprising metallic contacts are thought to be a major hurdle to the realization of organic laser diodes. We demonstrate here that careful tuning of the waveguide mode in flexible distributed feedback lasers can allow lasing action to occur in organic thin films in the p... | Metallic contacts; Organic laser diodes; Waveguides; Feedback lasers | 2004 |
| 392 |
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Bernstein, Paul S.; Gellermann, Werner | Macular pigment Raman detector for clinical applications | Clinical studies of carotenoid macular pigments (MP) have been limited by the lack of noninvasive, objective instruments. We introduce a novel noninvasive optical instrument, an MP Raman detector, for assessment of the carotenoid status of the human retina in vivo. The instrument uses resonant excit... | Diagnosis, Computer-Assisted; Equipment Failure Analysis; Sensitivity and Specificity | 2004 |
| 393 |
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Symko, Orest George | Magnetic anisotropy of Zn-Cr alloys at very low temperatures | The temperature dependent magnetization of Zn-Cr single crystals was measured from 2K down to 10 mK using a SQUID magnetometer. A large anisotropy is observed for the magnetization along the parallel and perpendicular axes of the crystal. For low concentrations impurity-impurity reactions do not do... | Magnetic anisotropy; Zn-Cr alloys; Temperature dependent magnetization | 1978 |
| 394 |
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Vardeny, Zeev Valentine | Magnetic field effects in ∏-conjugated polymer-fullerene blends: evidence for multiple components | We studied magnetoconductance (MC) and magnetoelectroluminescence (MEL) in organic diodes from blends of ∏-conjugated polymers and fullerenes at various concentrations, c. The MC response is composed of several components that depend on the applied bias voltage and c. A dominant positive low-field... | pi-conjugated polymers; Fullerene blends; Magnetic field effects; Magnetoconductance; Magnetoelectroluminescence; MC; MEL; Organic magnetoresistance; OMAR; Organic diodes | 2008-12 |
| 395 |
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Symko, Orest George | Magnetic memory of oil paintings | The color in oil paints is obtained sometimes from magnetic minerals. This fact implies that oil paintings could present an intrinsic magnetization. Magnetic imaging of an oil painting consists in the measurement of magnetic flux related to the magnetization of the painting. In this report results o... | Magnetic memory; Oil paintings; Authentication | 2007 |
| 396 |
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Symko, Orest George | Magnetic shielding and relaxation characteristics of superconducting YBa2Cu3O7 tubes | High-7c superconducting tubes have been developed for magnetic shielding of SQUIDs at 77 K. The characteristics of such tubes show that adequate shielding exists for magnetic fields up to a critical field determined by the current density of the tube. Relaxation phenomena with two different time de... | YBa2Cu3O7 tubes; High-Tc; SQUID | 1989 |
| 397 |
 |
Mattis, Daniel C. | Magnetic susceptibilities of finite Ising chains in the presence of defect sites | Any antiferromagnet with zero net magnetic moment exhibits limited response to an external homogeneous magnetic field. This changes dramatically in the presence of defect sites, even those that carry no spin. We examine the excess susceptibilities, longitudinal and transverse, due to one or more d... | Antiferromagnets; Defects; Ising chain; Longitudinal field; Transverse field | 2007-12 |
| 398 |
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Rogachev, Andrey | Magnetic-field dependent differential capacitance of polymer diodes | Using admittance spectroscopy, we found that bipolar organic diodes based on pi-conjugated polymer, 2-methoxy-5-(20-ethylhexyloxy), MEH-PPV, have strong divergent contribution to the device differential capacitance. It is positive at low bias voltages, turns negative at intermediate biases, and beco... | | 2012-01-01 |
| 399 |
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Rogachev, Andrey | Magnetic-field enhancement of superconductivity in ultranarrow wires | We study the effect of an applied magnetic field on sub-10-nm wide MoGe and Nb superconducting wires. We find that magnetic fields can enhance the critical supercurrent at low temperatures, and do so more strongly for narrower wires. We conjecture that magnetic moments are present, but their pair-... | Ultranarrow wires; Magnetic-field enhancement | 2006-09 |
| 400 |
 |
Vardeny, Zeev Valentine | Magnetic-field-dependent carrier injection at La2/3Sr1/3MnO3/ and organic semiconductors interfaces | We have fabricated organic diodes utilizing several ∏-conjugated organic semiconductors (OSEC) as spacer layers between La2=3Sr1=3MnO3 (LSMO) and various metallic electrodes, and measured their magnetoresistance (MR) and magnetoelectroluminescence (MEL) responses. The devices exhibit large negat... | Organic diodes; pi-conjugated organic semicondutors; OSEC; LSMO; MR; Magnetoelectroluminescence; MEL | 2005-07 |
