Modeling, Analysis, and Interpretation of Photoelectron Energy Spectra at Enceladus Observed by Cassini

NASA Astrophysics Data System (ADS)

Taylor, S. A.; Coates, A. J.; Jones, G. H.; Wellbrock, A.; Fazakerley, A. N.; Desai, R. T.; Caro-Carretero, R.; Michiko, M. W.; Schippers, P.; Waite, J. H.

2018-01-01

The Electron Spectrometer (ELS) of the Cassini Plasma Spectrometer has observed photoelectrons produced in the plume of Enceladus. These photoelectrons are observed during Enceladus encounters in the energetic particle shadow where the spacecraft is largely shielded from penetrating radiation by the moon. We present a complex electron spectrum at Enceladus including evidence of two previously unidentified electron populations at 6-10 eV and 10-16 eV. We estimate that the proportion of "hot" (>15 eV) to "cold" (<15 eV) electrons during the Enceladus flybys is ≈ 0.1-0.5%. We have constructed a model of photoelectron production in the plume and compared it with ELS Enceladus flyby data by scaling and energy shifting according to spacecraft potential. We suggest that the complex structure of the electron spectrum observed can be explained entirely by photoelectron production in the plume ionosphere.

Instrument Packages for the Cold, Dark, High Radiation Environments

NASA Technical Reports Server (NTRS)

Clark, P. E.; Millar, P. S.; Yeh, P. S.; Beamna, B.; Brigham, D.; Feng, S.

2011-01-01

We are developing a small cold temperature instrument package concept that integrates a cold temperature power system and radhard ultra low temperature ultra low power electronics components and power supplies now under development into a cold temperature surface operational version of a planetary surface instrument package. We are already in the process of developing a lower power lower tem-perature version for an instrument of mutual interest to SMD and ESMD to support the search for volatiles (the mass spectrometer VAPoR, Volatile Analysis by Pyrolysis of Regolith) both as a stand alone instrument and as part of an environmental monitoring package.

Cu(In,Ga)Se2 surface treatment with Na and NaF: A combined photoelectron spectroscopy and surface photovoltage study in ultra-high vacuum

NASA Astrophysics Data System (ADS)

Parvan, V.; Mizrak, A.; Majumdar, I.; Ümsür, B.; Calvet, W.; Greiner, D.; Kaufmann, C. A.; Dittrich, T.; Avancini, E.; Lauermann, I.

2018-06-01

Either metallic Na or NaF were deposited onto Cu(In,Ga)Se2 surfaces and studied by photoelectron spectroscopy and surface photovoltage spectroscopy without breaking the ultra-high vacuum. The deposition of elemental Na at room temperature led to the formation of an intermediate Cu and Ga rich layer at the CIGSe surface, whereas for NaF the composition of the CIGSe surface remained unchanged. A metal like surface induced by an inverted near surface region with a reduced number of defect states was formed after the deposition of Na. Under the chosen experimental conditions, the near surface layer was independent on the amount of Na and stable in time. In contrast, the usage of NaF weakened the inversion and led to an increased band bending compared to the untreated CIGSe sample. The SPV signals decreased with proceeding time after the deposition of NaF.

Ultra-thin grain-oriented silicon steel sheet fabricated by a novel way: Twin-roll strip casting and two-stage cold rolling

NASA Astrophysics Data System (ADS)

Wang, Yin-Ping; Liu, Hai-Tao; Song, Hong-Yu; Liu, Jia-Xin; Shen, Hui-Ying; Jin, Yang; Wang, Guo-Dong

2018-04-01

0.05-0.15 mm-thick ultra-thin grain-oriented silicon steel sheets were successfully produced by a novel processing route including strip casting, hot rolling, normalizing, two-stage cold rolling with intermediate annealing, primary recrystallization annealing and secondary recrystallization annealing. The evolutions of microstructure, texture and inhibitor along the processing were briefly investigated. The results showed that the initial Goss orientation originated due to the heterogenous nucleation of δ-ferrite grains during solidification. Because of the lack of shear deformation, only a few Goss grains were observed in the hot rolled sheet. After the first cold rolling and intermediate annealing, Goss texture was enhanced and distributed in the whole thickness. A small number of Goss grains having a high fraction of high energy boundaries exhibited in the primary recrystallization annealed sheet. A large number of fine and dispersed MnS and AlN and a few co-precipitates MnS and AlN with the size range of 10-70 nm were also observed. Interestingly, a well-developed secondary recrystallization microstructure characterized by 10-60 mm grains and a sharp Goss texture were finally produced in the 0.05-0.15 mm-thick ultra-thin sheets. A magnetic induction B8 of 1.72-1.84 T was obtained. Another new finding was that a few {2 3 0}〈0 0 1〉 and {2 1 0}〈1 2 7〉 grains also can grow up abnormally because of the high fraction of high energy boundaries and the size and number advantage, respectively. These non-Goss grains finally deteriorated the magnetic properties of the ultra-thin sheets. In addition, low surface energies of {hk0} planes may also contribute to the abnormal growth of Goss, {2 3 0}〈0 0 1〉 and {2 1 0}〈1 2 7〉 grains.

Laser-Free Cold-Atom Gymnastics

NASA Astrophysics Data System (ADS)

Gould, Harvey; Feinberg, Benedict; Munger, Charles T., Jr.; Nishimura, Hiroshi

2017-01-01

We have performed beam transport simulations on ultra cold (2 μK) and cold (130 μK) neutral Cs atoms in the F = M = + 4 (magnetic weak-field seeking) ground state. We use inhomogeneous magnetic fields to focus and accelerate the atoms. Acceleration of neutral atoms by an inhomogeneous magnetic field was demonstrated by Stern and Gerlach in 1922. In the simulations, a two mm diameter cloud of atoms is released to fall under gravity. A magnetic coil focuses the falling atoms. After falling 41 cm, the atoms are reflected in the magnetic fringe field of a solenoid. They return to their starting height, about 0.7 s later, having passed a second time through the focusing coil. The simulations show that > 98 % of ultra cold Cs atoms and > 70 % of cold Cs atoms will survive at least 15 round trips (assuming perfect vacuum). More than 100 simulations were run to optimize coil currents and focusing coil diameter and height. Simulations also show that atoms can be launched into a fountain. An experimental apparatus to test the simulations, is being constructed. This technique may find application in atomic fountain clocks, interferometers, and gravitometers, and may be adaptable for use in microgravity. It may also work with Bose-Einstein condensates of paramagnetic atoms.

Interaction-induced conducting-non-conducting transition of ultra-cold atoms in one-dimensional optical lattices

NASA Astrophysics Data System (ADS)

Chien, Chih-Chun; Gruss, Daniel; Di Ventra, Massimiliano; Zwolak, Michael

2013-06-01

The study of time-dependent, many-body transport phenomena is increasingly within reach of ultra-cold atom experiments. We show that the introduction of spatially inhomogeneous interactions, e.g., generated by optically controlled collisions, induce negative differential conductance in the transport of atoms in one-dimensional optical lattices. Specifically, we simulate the dynamics of interacting fermionic atoms via a micro-canonical transport formalism within both a mean-field and a higher-order approximation, as well as with a time-dependent density-matrix renormalization group (DMRG). For weakly repulsive interactions, a quasi-steady-state atomic current develops that is similar to the situation occurring for electronic systems subject to an external voltage bias. At the mean-field level, we find that this atomic current is robust against the details of how the interaction is switched on. Further, a conducting-non-conducting transition exists when the interaction imbalance exceeds some threshold from both our approximate and time-dependent DMRG simulations. This transition is preceded by the atomic equivalent of negative differential conductivity observed in transport across solid-state structures.

Laser and Optical Subsystem for NASA's Cold Atom Laboratory

NASA Astrophysics Data System (ADS)

Kohel, James; Kellogg, James; Elliott, Ethan; Krutzik, Markus; Aveline, David; Thompson, Robert

2016-05-01

We describe the design and validation of the laser and optics subsystem for NASA's Cold Atom Laboratory (CAL), a multi-user facility being developed at NASA's Jet Propulsion Laboratory for studies of ultra-cold quantum gases in the microgravity environment of the International Space Station. Ultra-cold atoms will be generated in CAL by employing a combination of laser cooling techniques and evaporative cooling in a microchip-based magnetic trap. Laser cooling and absorption imaging detection of bosonic mixtures of 87 Rb and 39 K or 41 K will be accomplished using a high-power (up to 500 mW ex-fiber), frequency-agile dual wavelength (767 nm and 780 nm) laser and optical subsystem. The CAL laser and optical subsystem also includes the capability to generate high-power multi-frequency optical pulses at 784.87 nm to realize a dual-species Bragg atom interferometer. Currently at Humboldt-Universität zu Berlin.

Recent approaches for bridging the pressure gap in photoelectron microspectroscopy

PubMed Central

Kolmakov, Andrei; Gregoratti, Luca; Kiskinova, Maya; Günther, Sebastian

2016-01-01

Ambient-pressure photoelectron spectroscopy (APPES) and microscopy are at the frontier of modern chemical analysis at liquid-gas, solid-liquid and solid-gas interfaces, bridging science and engineering of functional materials. Complementing the current state-of-the art of the instruments, we survey in this short review several alternative APPES approaches, developed recently in the scanning photoelectron microscope (SPEM) at the Elettra laboratory. In particular, we report on experimental setups for dynamic near-ambient pressure environment, using pulsed-gas injection in the vicinity of samples or reaction cells with very small apertures, allowing for experiments without introducing additional differential pumping stages. The major part of the review is dedicated to the construction and performance of novel environmental cells using ultrathin electron-transparent but molecularly impermeable membranes to isolate the gas or liquid ambient from the electron detector operating in ultra-high vacuum (UHV). We demonstrate that two dimensional materials, such as graphene and derivatives, are mechanically robust to withstand atmospheric - UHV pressure differences and are sufficiently transparent for the photoelectrons emitted from samples immersed in the liquid or gaseous media. There are many unique opportunities for APPES using X-rays over a wide energy range. We show representative results that illustrate the potential of these ‘ambient-pressure’ approaches. Combined with the ca 100 nm lateral resolution of SPEM, they can overcome the pressure gap challenges and address the evolution of chemical composition and electronic structure at surface and interfaces under realistic operation conditions with unprecedented lateral and spectral resolution. PMID:28008215

Photodetachment spectroscopy and resonant photoelectron imaging of cryogenically-cooled deprotonated 2-hydroxypyrimidine anions

NASA Astrophysics Data System (ADS)

Huang, Dao-Ling; Zhu, Guo-Zhu; Liu, Yuan; Wang, Lai-Sheng

2017-02-01

We report a photodetachment and high-resolution photoelectron imaging study of cold deprotonated 2-hydroxypyrimidine anions, C4H3N2O-. Photodetachment spectroscopy reveals an excited dipole-bound state (DBS) of C4H3N2O- with a binding energy of 598 ± 5 cm-1 below the detachment threshold of 26,010 ± 5 cm-1. Twenty vibrational levels of the DBS are observed as resonances in the photodetachment spectrum, with three below the detachment threshold and seventeen above the threshold. By tuning the detachment laser to the above-threshold vibrational resonances, highly non-Franck-Condon photoelectron spectra are obtained. Nine fundamental vibrational frequencies are resolved, including six symmetry-forbidden modes. The 598 cm-1 binding energy for the DBS is quite high due to the large dipole moment of the C4H3N2Orad (>6 D). However, no evidence of a second DBS is observed below the detachment threshold.

Condensation of galactic cold dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Visinelli, Luca

2016-07-07

We consider the steady-state regime describing the density profile of a dark matter halo, if dark matter is treated as a Bose-Einstein condensate. We first solve the fluid equation for “canonical” cold dark matter, obtaining a class of density profiles which includes the Navarro-Frenk-White profile, and which diverge at the halo core. We then solve numerically the equation obtained when an additional “quantum pressure” term is included in the computation of the density profile. The solution to this latter case is finite at the halo core, possibly avoiding the “cuspy halo problem” present in some cold dark matter theories. Withinmore » the model proposed, we predict the mass of the cold dark matter particle to be of the order of M{sub χ}c{sup 2}≈10{sup −24} eV, which is of the same order of magnitude as that predicted in ultra-light scalar cold dark matter models. Finally, we derive the differential equation describing perturbations in the density and the pressure of the dark matter fluid.« less

Photoelectron Diffraction from Valence States of Oriented Molecules

NASA Astrophysics Data System (ADS)

Krüger, Peter

2018-06-01

The angular distribution of photoelectrons emitted from valence states of oriented molecules is investigated. The principles underlying the angular pattern formation are explained in terms of photoelectron wave interference, caused by initial state delocalization and final state photoelectron scattering. Computational approaches to photoelectron spectroscopy from molecules are briefly reviewed. Here a combination of molecular orbital calculations for the initial state and multiple scattering theory for the photoelectron final state is used and applied to the 3σ and 4σ orbitals of nitrogen and the highest occupied molecular orbital of pentacene. Appreciable perpendicular emission and circular dichroism in angular distributions is found, two effects that cannot be described by the popular plane wave approximation to the photoelectron final state.

Electronic structure of germanium selenide investigated using ultra-violet photo-electron spectroscopy

NASA Astrophysics Data System (ADS)

Mishra, P.; Lohani, H.; Kundu, A. K.; Patel, R.; Solanki, G. K.; Menon, Krishnakumar S. R.; Sekhar, B. R.

2015-07-01

The valence band electronic structure of GeSe single crystals has been investigated using angle resolved photoemission spectroscopy (ARPES) and x-ray photoelectron spectroscopy. The experimentally observed bands from ARPES, match qualitatively with our LDA-based band structure calculations along the Γ-Z, Γ-Y and Γ-T symmetry directions. The valence band maximum occurs nearly midway along the Γ-Z direction, at a binding energy of -0.5 eV, substantiating the indirect band gap of GeSe. Non-dispersive features associated with surface states and indirect transitions have been observed. The difference in hybridization of Se and Ge 4p orbitals leads to the variation of dispersion along the three symmetry directions. The predominance of the Se 4pz orbitals, evidenced from theoretical calculations, may be the cause for highly dispersive bands along the Γ-T direction. Detailed electronic structure analysis reveals the significance of the cation-anion 4p orbitals hybridization in the valence band dispersion of IV-VI semiconductors. This is the first comprehensive report of the electronic structure of a GeSe single crystal using ARPES in conjugation with theoretical band structure analysis.

Quantification of the toxic hexavalent chromium content in an organic matrix by X-ray photoelectron spectroscopy (XPS) and ultra-low-angle microtomy (ULAM)

NASA Astrophysics Data System (ADS)

Greunz, Theresia; Duchaczek, Hubert; Sagl, Raffaela; Duchoslav, Jiri; Steinberger, Roland; Strauß, Bernhard; Stifter, David

2017-02-01

Cr(VI) is known for its corrosion inhibitive properties and is, despite legal regulations, still a potential candidate to be added to thin (1-3 μm) protective coatings applied on, e.g., electrical steel as used for transformers, etc. However, Cr(VI) is harmful to the environment and to the human health. Hence, a reliable quantification of it is of decisive interest. Commonly, an alkaline extraction with a photometric endpoint detection of Cr(VI) is used for such material systems. However, this procedure requires an accurate knowledge on sample parameters such as dry film thickness and coating density that are occasionally associated with significant experimental errors. We present a comprehensive study of a coating system with a defined Cr(VI) pigment concentration applied on electrical steel. X-ray photoelectron spectroscopy (XPS) was employed to resolve the elemental chromium concentration and the chemical state. Turning to the fact that XPS is extremely surface sensitive (<10 nm) and that the lowest commonly achievable lateral resolution is a number of times higher than the coating thickness (∼2 μm), a bulk analysis was achieved with XPS line scans on extended wedge-shaped tapers through the coating. For that purpose a special sample preparation step performed on an ultra-microtome was required prior to analysis. Since a temperature increase leads to a reduction of Cr(VI) we extend our method on samples, which were subjected to different curing temperatures. We show that our proposed approach now allows to determine the elemental and Cr(VI) concentration and distribution inside the coating.

The Coldest Object in the Universe: Probing the Mass Distribution of the Ultra-Cold Outflow and Dusty Disk in the Boomerang Nebula

NASA Technical Reports Server (NTRS)

Sahai, R.; Vlemmings, W.; Nyman, L. A.

2014-01-01

Our Cycle 0 ALMA observations confirmed that the Boomerang Nebula is the coldest known object in the universe, with a massive high-speed outflow that has cooled significantly below the temperature of the cosmic background (CMB). The Boomerang's prodigious mass-loss rate (0.001 solar mass M yr (exp -1) and low-luminosity (300L ) make it a key object for understanding the remarkable transition of the circumstellar envelopes of AGB stars into bipolar planetary nebulae. We have obtained new ACA CO 1-0 data that recover much of the flux lost in the Cycle O data, and reveal heretofore unseen distant regions of the ultra-cold outflow reheated to temperatures above the CMB. Our CO J=3-2 data reveal the precise, highly collimated shape of an inner bipolar structure and its dense central waist, with unprecedented angular resolution (0.4 in). The waist shows a core-halo structure in the thermal dust emission at 0.88 millimeter, and its derived flux at this wavelength, compared with the 3.3, 2.6, and 1.3 millimeter fluxes support the presence of about 5 x 10 (exp -4) solar mass of very large (approximately millimeter-sized), cold (approximately 30K) grains. We also find the unexpected presence of weak SO emission, possibly resulting from the release of S from grains due to high-speed shocks.

The Coldest Object in the Universe: Probing the Mass Distribution of the Ultra-Cold Outflow and Dusty Disk in the Boomerang Nebula

NASA Astrophysics Data System (ADS)

Sahai, R.; Vlemmings, W.; Nyman, L.

2015-12-01

Our Cycle 0 ALMA observations confirmed that the Boomerang Nebula is the coldest known object in the Universe, with a massive high-speed outflow that has cooled significantly below the temperature of the cosmic background (CMB). The Boomerang's prodigious mass-loss rate (0.001M⊙) and low-luminosity (300L⊙) make it a key object for understanding the remarkable transition of the circumstellar envelopes of AGB stars into bipolar planetary nebulae. We have obtained new ACA CO 1-0 data that recover much of the flux lost in the Cycle 0 data, and reveal heretofore unseen distant regions of the ultra-cold outflow re-heated to temperatures above the CMB. Our CO J=3-2 data reveal the precise, highly collimated shape of an inner bipolar structure and its dense central waist, with unprecedented angular resolution (0.4”). The waist shows a core-halo structure in the thermal dust emission at 0.88 mm, and its derived flux at this wavelength, compared with the 3.3, 2.6, and 1.3 mm fluxes support the presence of about 5×10-4 M⊙ of very large (˜mm-sized), cold (˜30K) grains. We also find the unexpected presence of weak SO emission, possibly resulting from the release of S from grains due to high-speed shocks.

Physiology and Pathophysiology in Ultra-Marathon Running

PubMed Central

Knechtle, Beat; Nikolaidis, Pantelis T.

2018-01-01

In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time) is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer ultra

Physiology and Pathophysiology in Ultra-Marathon Running.

PubMed

Knechtle, Beat; Nikolaidis, Pantelis T

2018-01-01

In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time) is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10-20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35-45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer ultra

EDITORIAL: Cold Quantum GasesEditorial: Cold Quantum Gases

NASA Astrophysics Data System (ADS)

Vassen, W.; Hemmerich, A.; Arimondo, E.

2003-04-01

This Special Issue of Journal of Optics B: Quantum and Semiclassical Optics brings together the contributions of various researchers working on theoretical and experimental aspects of cold quantum gases. Different aspects of atom optics, matter wave interferometry, laser manipulation of atoms and molecules, and production of very cold and degenerate gases are presented. The variety of subjects demonstrates the steadily expanding role associated with this research area. The topics discussed in this issue, extending from basic physics to applications of atom optics and of cold atomic samples, include: bulletBose--Einstein condensation bulletFermi degenerate gases bulletCharacterization and manipulation of quantum gases bulletCoherent and nonlinear cold matter wave optics bulletNew schemes for laser cooling bulletCoherent cold molecular gases bulletUltra-precise atomic clocks bulletApplications of cold quantum gases to metrology and spectroscopy bulletApplications of cold quantum gases to quantum computing bulletNanoprobes and nanolithography. This special issue is published in connection with the 7th International Workshop on Atom Optics and Interferometry, held in Lunteren, The Netherlands, from 28 September to 2 October 2002. This was the last in a series of Workshops organized with the support of the European Community that have greatly contributed to progress in this area. The scientific part of the Workshop was managed by A Hemmerich, W Hogervorst, W Vassen and J T M Walraven, with input from members of the International Programme Committee who are listed below. The practical aspects of the organization were ably handled by Petra de Gijsel from the Vrije Universiteit in Amsterdam. The Workshop was funded by the European Science Foundation (programme BEC2000+), the European Networks 'Cold Quantum Gases (CQG)', coordinated by E Arimondo, and 'Cold Atoms and Ultraprecise Atomic Clocks (CAUAC)', coordinated by J Henningsen, by the German Physical Society (DFG), by

Intense ionizing radiation from laser-induced processes in ultra-dense deuterium D(-1)

NASA Astrophysics Data System (ADS)

Olofson, Frans; Holmlid, Leif

2014-09-01

Nuclear fusion in ultra-dense deuterium D(-1) has been reported from our laboratory in a few studies using pulsed lasers with energy < 0.2 J. The direct observation of massive particles with energy 1-20 MeV u-1 is conclusive proof for fusion processes, either as a cause or as a result. Continuing the step-wise approach necessary for untangling a complex problem, the high-energy photons from the laser-induced plasma are now studied. The focus is here on the photoelectrons formed. The photons penetrating a copper foil have energy > 80 keV. The total charge created is up to 2 μC or 1 × 1013 photoelectrons per laser shot at 0.13 J pulse energy, assuming isotropic photon emission. The variation of the photoelectron current with laser intensity is faster than linear for some systems, which indicates rapid approach to volume ignition. On a permanent magnet at approximately 1 T, a laser pulse-energy threshold exists for the laser-induced processes probably due to the floating of most clusters of D(-1) in the magnetic field. This Meissner effect was reported previously.

Dual analyzer system for surface analysis dedicated for angle-resolved photoelectron spectroscopy at liquid surfaces and interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niedermaier, Inga; Kolbeck, Claudia; Steinrück, Hans-Peter

The investigation of liquid surfaces and interfaces with the powerful toolbox of ultra-high vacuum (UHV)-based surface science techniques generally has to overcome the issue of liquid evaporation within the vacuum system. In the last decade, however, new classes of liquids with negligible vapor pressure at room temperature—in particular, ionic liquids (ILs)—have emerged for surface science studies. It has been demonstrated that particularly angle-resolved X-ray Photoelectron Spectroscopy (ARXPS) allows for investigating phenomena that occur at gas-liquid and liquid-solid interfaces on the molecular level. The results are not only relevant for IL systems but also for liquids in general. In all ofmore » these previous ARXPS studies, the sample holder had to be tilted in order to change the polar detection angle of emitted photoelectrons, which restricted the liquid systems to very thin viscous IL films coating a flat solid support. We now report on the concept and realization of a new and unique laboratory “Dual Analyzer System for Surface Analysis (DASSA)” which enables fast ARXPS, UV photoelectron spectroscopy, imaging XPS, and low-energy ion scattering at the horizontal surface plane of macroscopically thick non-volatile liquid samples. It comprises a UHV chamber equipped with two electron analyzers mounted for simultaneous measurements in 0° and 80° emission relative to the surface normal. The performance of DASSA on a first macroscopic liquid system will be demonstrated.« less

Photoelectron Spectroscopy Study of Quinonimides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, Ekram; Deng, Shihu M.; Gozem, Samer

Structures and energetics of o-, m- and p-quinonimide anions (OC6H4N) and quinoniminyl radicals have been investigated by using negative ion photoelectron spectroscopy. Modeling of the photoelectron spectrum of the ortho isomer shows that the ground state of the anion is a triplet, while the quinoniminyl radical has a doublet ground state with a doublet-quartet splitting of 35.5 kcal/mol. The para radical has doublet ground state, but a band for a quartet state is missing from the photoelectron spectrum indicating that the anion has a singlet ground state, in contrast to previously reported calculations. The theoretical modeling is revisited here, andmore » it is shown that accurate predictions for the electronic structure of the para quinonimide anion require both an accurate account of electron correlation and a sufficiently diffuse basis set. Electron affinities of o- and p-quinoniminyl radicals are measured to be 1.715 ± 0.010 and 1.675 ± 0.010 eV, respectively. The photoelectron spectrum of the m-quinonimide anion shows that the ion undergoes several different rearrangements, including a rearrangement to the energetically favorable para isomer. Such rearrangements preclude a meaningful analysis of the experimental spectrum.« less

X-ray Photoelectron Spectroscopy Database (Version 4.1)

National Institute of Standards and Technology Data Gateway

SRD 20 X-ray Photoelectron Spectroscopy Database (Version 4.1) (Web, free access)   The NIST XPS Database gives access to energies of many photoelectron and Auger-electron spectral lines. The database contains over 22,000 line positions, chemical shifts, doublet splittings, and energy separations of photoelectron and Auger-electron lines.

Energetic (above 60 eV) atmospheric photoelectrons

NASA Technical Reports Server (NTRS)

Winningham, J. D.; Decker, D. T.; Kozyra, J. U.; Nagy, A. F.; Jasperse, J. R.

1989-01-01

Data from low altitude plasma instrument (LAPI) on Dynamics Explorer 2 document a population of high-energy (up to 800 eV) atmospheric photoelectrons that has not been reported in the published literature. The source of these photoelectrons is postulated to be the soft X-ray portion of the whole sun spectrum. This conclusion is supported by sunrise-sunset characteristics that track those of the classical (below 60 eV) EUV-produced photoelectrons, and theoretical results from two models that incorporate the soft X-ray portion of the solar spectrum. The models include K-shell ionization effects and predict peaks in the photoelectron spectrum due to Auger electrons emitted from oxygen and nitrogen. The peak for nitrogen is observed as predicted, but the peak for oxygen is barely observable. Excellent quantitative agreement is achieved between theory and experiment by using reasonable adjustments to the few published soft X-ray spectra based on solar activity. The upflowing energetic photoelectrons provide a heretofore unknown source of electrons to the magnetosphere. They occur whenever and wherever the sun is up, that is, at all invariant latitudes. Their density is low, but they are steady and ubiquitous. If scattering and trapping occur on closed field lines, then photoelectrons could contribute as a significant particle source and thus represent a new facet of magnetosphere-ionosphere coupling.

Synthesis and photoluminescence of ultra-pure germanium nanoparticles

NASA Astrophysics Data System (ADS)

Chivas, R.; Yerci, S.; Li, R.; Dal Negro, L.; Morse, T. F.

2011-09-01

We have used aerosol deposition to synthesize defect and micro-strain free, ultra-pure germanium nanoparticles. Transmission electron microscopy images show a core-shell configuration with highly crystalline core material. Powder X-ray diffraction measurements verify the presence of highly pure, nano-scale germanium with average crystallite size of 30 nm and micro-strain of 0.058%. X-ray photoelectron spectroscopy demonstrates that GeO x ( x ⩽ 2) shells cover the surfaces of the nanoparticles. Under optical excitation, these nanoparticles exhibit two separate emission bands at room temperature: a visible emission at 500 nm with 0.5-1 ns decay times and an intense near-infrared emission at 1575 nm with up to ˜20 μs lifetime.

Precision analysis of the photomultiplier response to ultra low signals

NASA Astrophysics Data System (ADS)

Degtiarenko, Pavel

2017-11-01

A new computational model for the description of the photon detector response functions measured in conditions of low light is presented, together with examples of the observed photomultiplier signal amplitude distributions, successfully described using the parameterized model equation. In extension to the previously known approximations, the new model describes the underlying discrete statistical behavior of the photoelectron cascade multiplication processes in photon detectors with complex non-uniform gain structure of the first dynode. Important features of the model include the ability to represent the true single-photoelectron spectra from different photomultipliers with a variety of parameterized shapes, reflecting the variability in the design and in the individual parameters of the detectors. The new software tool is available for evaluation of the detectors' performance, response, and efficiency parameters that may be used in various applications including the ultra low background experiments such as the searches for Dark Matter and rare decays, underground neutrino studies, optimizing operations of the Cherenkov light detectors, help in the detector selection procedures, and in the experiment simulations.

Precision analysis of the photomultiplier response to ultra low signals

DOE PAGES

Degtiarenko, Pavel

2017-08-05

Here, a new computational model for the description of the photon detector response functions measured in conditions of low light is presented, together with examples of the observed photomultiplier signal amplitude distributions, successfully described using the parameterized model equation. In extension to the previously known approximations, the new model describes the underlying discrete statistical behavior of the photoelectron cascade multiplication processes in photon detectors with complex non-uniform gain structure of the first dynode. Important features of the model include the ability to represent the true single-photoelectron spectra from different photomultipliers with a variety of parameterized shapes, reflecting the variability inmore » the design and in the individual parameters of the detectors. The new software tool is available for evaluation of the detectors’ performance, response, and efficiency parameters that may be used in various applications including the ultra low background experiments such as the searches for Dark Matter and rare decays, underground neutrino studies, optimizing operations of the Cherenkov light detectors, help in the detector selection procedures, and in the experiment simulations.« less

Analytic approach to photoelectron transport.

NASA Technical Reports Server (NTRS)

Stolarski, R. S.

1972-01-01

The equation governing the transport of photoelectrons in the ionosphere is shown to be equivalent to the equation of radiative transfer. In the single-energy approximation this equation is solved in closed form by the method of discrete ordinates for isotropic scattering and for a single-constituent atmosphere. The results include prediction of the angular distribution of photoelectrons at all altitudes and, in particular, the angular distribution of the escape flux. The implications of these solutions in real atmosphere calculations are discussed.

Bimolecular reaction dynamics from photoelectron spectroscopy of negative ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradforth, S.E.

1992-11-01

The transition state region of a neutral bimolecular reaction may be experimentally investigated by photoelectron spectroscopy of an appropriate negative ion. The photoelectron spectrum provides information on the spectroscopy and dynamics of the short lived transition state and may be used to develop model potential energy surfaces that are semi-quantitative in this important region. The principles of bound [yields] bound negative ion photoelectron spectroscopy are illustrated by way of an example: a full analysis of the photoelectron bands of CN[sup [minus

Peculiarities of Spacecraft Photoelectron Shield Formation in Magnetic Field

NASA Astrophysics Data System (ADS)

Veselov, Mikhail; Chugunin, Dmitriy

Traditionally, the current balance equations for a spacecraft in space plasma rely on the electric field of positively charged spacecraft. Equilibrium potential V is derived from currents outward and toward the spacecraft body. The currents are in turn functions of V. However, in reality photoelectrons move in both the electric field of the spacecraft and the Earth or the interplanetary magnetic field. This causes an anisotropic distribution of photoelectrons along a magnetic field line with the characteristic size of the order of several photoelectron gyro-radii. As a result, confinement of photoelectrons in the spacecraft-related electric field is much longer. Thus, a fraction of returned photoelectrons in the electron current toward the spacecraft can be rather great and may even dominate several times over the ambient electrons’ fraction. Modeled ph-electron trajectories as well as general photoelectron shield distribution around spacecraft are represented, and comparison of experimental data on the electron density with the magnetic flux tube model is discussed.

Perspective: Electrospray photoelectron spectroscopy: From multiply-charged anions to ultracold anions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lai-Sheng, E-mail: Lai-Sheng-Wang@brown.edu

2015-07-28

Electrospray ionization (ESI) has become an essential tool in chemical physics and physical chemistry for the production of novel molecular ions from solution samples for a variety of spectroscopic experiments. ESI was used to produce free multiply-charged anions (MCAs) for photoelectron spectroscopy (PES) in the late 1990 s, allowing many interesting properties of this class of exotic species to be investigated. Free MCAs are characterized by strong intramolecular Coulomb repulsions, which create a repulsive Coulomb barrier (RCB) for electron emission. The RCB endows many fascinating properties to MCAs, giving rise to meta-stable anions with negative electron binding energies. Recent developmentmore » in the PES of MCAs includes photoelectron imaging to examine the influence of the RCB on the electron emission dynamics, pump-probe experiments to examine electron tunneling through the RCB, and isomer-specific experiments by coupling PES with ion mobility for biological MCAs. The development of a cryogenically cooled Paul trap has led to much better resolved PE spectra for MCAs by creating vibrationally cold anions from the room temperature ESI source. Recent advances in coupling the cryogenic Paul trap with PE imaging have allowed high-resolution PE spectra to be obtained for singly charged anions produced by ESI. In particular, the observation of dipole-bound excited states has made it possible to conduct vibrational autodetachment spectroscopy and resonant PES, which yield much richer vibrational spectroscopic information for dipolar free radicals than traditional PES.« less

Cold Shock Induction of Thermal Sensitivity in Listeria monocytogenes

PubMed Central

Miller, Arthur J.; Bayles, Darrell O.; Eblen, B. Shawn

2000-01-01

Cold shock at 0 to 15°C for 1 to 3 h increased the thermal sensitivity of Listeria monocytogenes. In a model broth system, thermal death time at 60°C was reduced by up to 45% after L. monocytogenes Scott A was cold shocked for 3 h. The duration of the cold shock affected thermal tolerance more than did the magnitude of the temperature downshift. The Z values were 8.8°C for controls and 7.7°C for cold-shocked cells. The D values of cold-shocked cells did not return to control levels after incubation for 3 h at 28°C followed by heating at 60°C. Nine L. monocytogenes strains that were cold shocked for 3 h exhibited D60 values that were reduced by 13 to 37%. The D-value reduction was greatest in cold-shocked stationary-phase cells compared to cells from cultures in either the lag or exponential phases of growth. In addition, cold-shocked cells were more likely to be inactivated by a given heat treatment than nonshocked cells, which were more likely to experience sublethal injury. The D values of chloramphenicol-treated control cells and chloramphenicol-treated cold-shocked cells were no different from those of untreated cold-shocked cells, suggesting that cold shock suppresses synthesis of proteins responsible for heat protection. In related experiments, the D values of L. monocytogenes Scott A were decreased 25% on frankfurter skins and 15% in ultra-high temperature milk if the inoculated products were first cold shocked. Induction of increased thermal sensitivity in L. monocytogenes by thermal flux shows potential to become a practical and efficacious preventative control method. PMID:11010880

Photoelectron imaging of doped helium nanodroplets

NASA Astrophysics Data System (ADS)

Neumark, Daniel

2008-03-01

Photoelectron images of helium nanodroplets doped with Kr and Ne atoms are reported. The images and resulting photoelectron spectra were obtained using tunable synchrotron radiation to ionize the droplets. Droplets were excited at 21.6 eV, corresponding to a strong droplet electronic excitation. The rare gas dopant is then ionized via a Penning excitation transfer process. The electron kinetic energy distributions reflect complex ionization and electron escape dynamics.

Bimolecular reaction dynamics from photoelectron spectroscopy of negative ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradforth, Stephen Edmund

1992-11-01

The transition state region of a neutral bimolecular reaction may be experimentally investigated by photoelectron spectroscopy of an appropriate negative ion. The photoelectron spectrum provides information on the spectroscopy and dynamics of the short lived transition state and may be used to develop model potential energy surfaces that are semi-quantitative in this important region. The principles of bound {yields} bound negative ion photoelectron spectroscopy are illustrated by way of an example: a full analysis of the photoelectron bands of CN -, NCO - and NCS -. Transition state photoelectron spectra are presented for the following systems Br + HI, Clmore » + HI, F + HI, F + CH 30H,F + C 2H 5OH,F + OH and F + H 2. A time dependent framework for the simulation and interpretation of the bound → free transition state photoelectron spectra is subsequently developed and applied to the hydrogen transfer reactions Br + HI, F + OH → O( 3P, 1D) + HF and F + H 2. The theoretical approach for the simulations is a fully quantum-mechanical wave packet propagation on a collinear model reaction potential surface. The connection between the wavepacket time evolution and the photoelectron spectrum is given by the time autocorrelation function. For the benchmark F + H 2 system, comparisons with three-dimensional quantum calculations are made.« less

Photoelectron studies of machined brass surfaces

NASA Astrophysics Data System (ADS)

Potts, A. W.; Merrison, J. P.; Tournas, A. D.; Yacoot, A.

UV photoelectron spectroscopy has been used to determine the surface composition of machined brass. The results show a considerable change between the photoelectron surface composition and the bulk composition of the same sample determined by energy-dispersive X-ray fluorescence. On the surface the lead composition is increased by ˜900 G. This is consistent with the important part that lead is believed to play in improving the machinability of this alloy.

Photoelectron spectrometer for attosecond spectroscopy of liquids and gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, I.; Huppert, M.; Wörner, H. J., E-mail: hwoerner@ethz.ch

2015-12-15

A new apparatus for attosecond time-resolved photoelectron spectroscopy of liquids and gases is described. It combines a liquid microjet source with a magnetic-bottle photoelectron spectrometer and an actively stabilized attosecond beamline. The photoelectron spectrometer permits venting and pumping of the interaction chamber without affecting the low pressure in the flight tube. This pressure separation has been realized through a sliding skimmer plate, which effectively seals the flight tube in its closed position and functions as a differential pumping stage in its open position. A high-harmonic photon spectrometer, attached to the photoelectron spectrometer, exit port is used to acquire photon spectramore » for calibration purposes. Attosecond pulse trains have been used to record photoelectron spectra of noble gases, water in the gas and liquid states as well as solvated species. RABBIT scans demonstrate the attosecond resolution of this setup.« less

Radiation sterilization of medical devices. Effects of ionizing radiation on ultra-high molecular-weight polyethylene

NASA Astrophysics Data System (ADS)

Buchalla, R.; Schüttler, C.; Bögl, K. W.

1995-02-01

Sterilization by ionizing radiation has become, next to ethylene oxide treament, the most important "cold" sterilization process for medical devices made from plastics. The effects of ionizing radiation on the most important polymer for medical devices, ultra-high molecular-weight polyethylene, are briefly described in this review.

A Compact, High-Flux Cold Atom Beam Source

NASA Technical Reports Server (NTRS)

Kellogg, James R.; Kohel, James M.; Thompson, Robert J.; Aveline, David C.; Yu, Nan; Schlippert, Dennis

2012-01-01

The performance of cold atom experiments relying on three-dimensional magneto-optical trap techniques can be greatly enhanced by employing a highflux cold atom beam to obtain high atom loading rates while maintaining low background pressures in the UHV MOT (ultra-high vacuum magneto-optical trap) regions. Several techniques exist for generating slow beams of cold atoms. However, one of the technically simplest approaches is a two-dimensional (2D) MOT. Such an atom source typically employs at least two orthogonal trapping beams, plus an additional longitudinal "push" beam to yield maximum atomic flux. A 2D atom source was created with angled trapping collimators that not only traps atoms in two orthogonal directions, but also provides a longitudinal pushing component that eliminates the need for an additional push beam. This development reduces the overall package size, which in turn, makes the 2D trap simpler, and requires less total optical power. The atom source is more compact than a previously published effort, and has greater than an order of magnitude improved loading performance.

Damage and annealing recovery of boron-implanted ultra-shallow junction: The correlation between beam current and surface configuration

NASA Astrophysics Data System (ADS)

Chang, Feng-Ming; Wu, Zong-Zhe; Lin, Yen-Fu; Kao, Li-Chi; Wu, Cheng-Ta; JangJian, Shiu-Ko; Chen, Yuan-Nian; Lo, Kuang Yao

2018-03-01

The condition of the beam current in the implantation process is a key issue in the damage rate and structural evolution in the sequent annealing process, especially for ultra-shallow layers. In this work, we develop a compensative optical method combined with UV Raman, X-ray photoelectron spectroscopy (XPS), and X-ray absorption near edge spectroscopy (XANES) to inspect the influence of the beam current in the implantation process. The optima condition of the beam current in the implantation process is determined by higher effective Si-B bond portion in UV Raman spectra and less the peak of B-B bond in XPS spectra which is caused by B cluster defects. Results of XANES indicate that the B oxide layer is formed on the surface of the ultra-shallow junction. The defects in the ultra-shallow junction after annealing are analyzed by novel optical analyses, which cannot be inspected by a traditional thermal wave and resistance measurement. This work exhibits the structural variation of the ultra-shallow junction via a variant beam current and provides a valuable metrology in examining the chemical states and the effective activation in the implantation technology.

Photoelectron photoion molecular beam spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trevor, D.J.

1980-12-01

The use of supersonic molecular beams in photoionization mass spectroscopy and photoelectron spectroscopy to assist in the understanding of photoexcitation in the vacuum ultraviolet is described. Rotational relaxation and condensation due to supersonic expansion were shown to offer new possibilities for molecular photoionization studies. Molecular beam photoionization mass spectroscopy has been extended above 21 eV photon energy by the use of Stanford Synchrotron Radiation Laboratory (SSRL) facilities. Design considerations are discussed that have advanced the state-of-the-art in high resolution vuv photoelectron spectroscopy. To extend gas-phase studies to 160 eV photon energy, a windowless vuv-xuv beam line design is proposed.

Potentiation of buprenorphine antinociception with ultra-low dose naltrexone in healthy subjects.

PubMed

Hay, J L; La Vincente, S F; Somogyi, A A; Chapleo, C B; White, J M

2011-03-01

Previous reports have demonstrated greater antinociception following administration of a buprenorphine/naloxone combination compared to buprenorphine alone among healthy volunteers. The aim of the current investigation was to determine whether buprenorphine antinociception could be enhanced with the addition of ultra-low dose naltrexone, using a range of dose ratios. A repeated-measures, double-blind, cross-over trial was undertaken with 10 healthy participants. The effects of each buprenorphine:naltrexone ratio (100:1, 133:1, 166:1, and 200:1) on cold pressor tolerance time and respiration were compared to the effects of buprenorphine only. The 166:1 ratio was associated with significantly greater tolerance time to cold pressor pain than buprenorphine alone. Minimal respiratory depression and few adverse events were observed in all conditions. These findings suggest that, as previously described with naloxone, the addition of ultra-low dose naltrexone can enhance the antinociceptive effect of buprenorphine in humans. This potentiation is dose-ratio dependent and occurs without a concomitant increase in adverse effects. Copyright © 2010 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

Photoelectron Imaging as a Quantum Chemistry Visualization Tool

ERIC Educational Resources Information Center

Grumbling, Emily R.; Pichugin, Kostyantyn; Mabbs, Richard; Sanov, Andrei

2011-01-01

An overview and simple example of photoelectron imaging is presented, highlighting its efficacy as a pedagogical tool for visualizing quantum phenomena. Specifically, photoelectron imaging of H[superscript -] (the simplest negative ion) is used to demonstrate several quantum mechanical principles. This example could be incorporated into an…

Conformational effects in photoelectron circular dichroism

NASA Astrophysics Data System (ADS)

Turchini, S.

2017-12-01

Photoelectron circular dichroism (PECD) is a novel type of spectroscopy, which presents surprising sensitivity to conformational effects in chiral systems. While classical photoelectron spectroscopy mainly responds to conformational effects in terms of energy level shifts, PECD provides a rich and detailed response to tiny changes in electronic and structural properties by means of the intensity dispersion of the circular dichroism as a function of photoelectron kinetic energy. In this work, the basics of PECD will be outlined, emphasizing the role of interference from the l,l+/- 1 outgoing partial wave of the photoelectron in the PECD transition matrix element, which is responsible for the extreme sensitivity to conformational effects. Examples using molecular systems and interfaces will shed light on the powerful application of PECD to classical conformational effects such as group substitution, isomerism, conformer population and clustering. Moreover, the PECD results will be reported in challenging new fields where conformations play a key role, such as vibrational effects, transient chirality and time- resolved experiments. To date, PECD has mostly been based on synchrotron radiation facilities, but it also has a future as a table-top lab experiment by means of multiphoton ionization. An important application of PECD as an analytical tool will be reported. The aim of this review is to illustrate that in PECD, the presence of conformational effects is essential for understanding a wide range of effects from a new perspective, making it different from classical spectroscopy.

Photoelectron spectroscopic and microspectroscopic probes of ferroelectrics

NASA Astrophysics Data System (ADS)

Tǎnase, Liviu C.; Abramiuc, Laura E.; Teodorescu, Cristian M.

2017-12-01

This contribution is a review of recent aspects connected with photoelectron spectroscopy of free ferroelectric surfaces, metals interfaced with these surfaces, graphene-like layers together with some exemplifications concerning molecular adsorption, dissociations and desorptions occurring from ferroelectrics. Standard photoelectron spectroscopy is used nowadays in correlation with other characterization techniques, such as piezoresponse force microscopy, high resolution transmission electron spectroscopy, and ferroelectric hysteresis cycles. In this work we will concentrate mainly on photoelectron spectroscopy and spectro-microscopy characterization of ferroelectric thin films, starting from atomically clean ferroelectric surfaces of lead zirco-titanate, then going towards heterostructures using this material in combination with graphene-like carbon layers or with metals. Concepts involving charge accumulation and depolarization near surface will be revisited by taking into account the newest findings in this area.

Coherent control of photoelectron wavepacket angular interferograms

NASA Astrophysics Data System (ADS)

Hockett, P.; Wollenhaupt, M.; Baumert, T.

2015-11-01

Coherent control over photoelectron wavepackets, via the use of polarization-shaped laser pulses, can be understood as a time and polarization-multiplexed process, where the final (time-integrated) observable coherently samples all instantaneous states of the light-matter interaction. In this work, we investigate this multiplexing via computation of the observable photoelectron angular interferograms resulting from multi-photon atomic ionization with polarization-shaped laser pulses. We consider the polarization sensitivity of both the instantaneous and cumulative continuum wavefunction; the nature of the coherent control over the resultant photoelectron interferogram is thus explored in detail. Based on this understanding, the use of coherent control with polarization-shaped pulses as a methodology for a highly multiplexed coherent quantum metrology is also investigated, and defined in terms of the information content of the observable.

Further demonstration of the VRLA-type UltraBattery under medium-HEV duty and development of the flooded-type UltraBattery for micro-HEV applications

NASA Astrophysics Data System (ADS)

Furukawa, J.; Takada, T.; Monma, D.; Lam, L. T.

The UltraBattery has been invented by the CSIRO Energy Technology in Australia and has been developed and produced by the Furukawa Battery Co., Ltd., Japan. This battery is a hybrid energy storage device which combines a super capacitor and a lead-acid battery in single unit cells, taking the best from both technologies without the need of extra, expensive electronic controls. The capacitor enhances the power and lifespan of the lead-acid battery as it acts as a buffer during high-rate discharging and charging, thus enabling it to provide and absorb charge rapidly during vehicle acceleration and braking. The laboratory results of the prototype valve-regulated UltraBatteries show that the capacity, power, available energy, cold cranking and self-discharge of these batteries have met, or exceeded, all the respective performance targets set for both minimum and maximum power-assist HEVs. The cycling performance of the UltraBatteries under micro-, mild- and full-HEV duties is at least four times longer than that of the state-of-the-art lead-acid batteries. Importantly, the cycling performance of UltraBatteries is proven to be comparable or even better than that of the Ni-MH cells. On the other hand, the field trial of UltraBatteries in the Honda Insight HEV shows that the vehicle has surpassed 170,000 km and the batteries are still in a healthy condition. Furthermore, the UltraBatteries demonstrate very good acceptance of the charge from regenerative braking even at high state-of-charge, e.g., 70% during driving. Therefore, no equalization charge is required for the UltraBatteries during field trial. The HEV powered by UltraBatteries gives slightly higher fuel consumption (cf., 4.16 with 4.05 L/100 km) and CO 2 emissions (cf., 98.8 with 96 g km -1) compared with that by Ni-MH cells. There are no differences in driving experience between the Honda Insight powered by UltraBatteries and by Ni-MH cells. Given such comparable performance, the UltraBattery pack costs

Photoelectron spectroscopy of nitromethane anion clusters

NASA Astrophysics Data System (ADS)

Pruitt, Carrie Jo M.; Albury, Rachael M.; Goebbert, Daniel J.

2016-08-01

Nitromethane anion and nitromethane dimer, trimer, and hydrated cluster anions were studied by photoelectron spectroscopy. Vertical detachment energies, estimated electron affinities, and solvation energies were obtained from the photoelectron spectra. Cluster structures were investigated using theoretical calculations. Predicted detachment energies agreed with experiment. Calculations show water binds to nitromethane anion through two hydrogen bonds. The dimer has a non-linear structure with a single ionic Csbnd H⋯O hydrogen bond. The trimer has two different solvent interactions, but both involve the weak Csbnd H⋯O hydrogen bond.

Ion-Atom Cold Collisions and Atomic Clocks

NASA Technical Reports Server (NTRS)

Prestage, John D.; Maleki, Lute; Tjoelker, Robert L.

1997-01-01

Collisions between ultracold neutral atoms have for some time been the subject of investigation, initially with hydrogen and more recently with laser cooled alkali atoms. Advances in laser cooling and trapping of neutral atoms in a Magneto-Optic Trap (MOT) have made cold atoms available as the starting point for many laser cooled atomic physics investigations. The most spectacularly successful of these, the observation of Bose-Einstein Condensation (BEC) in a dilute ultra-cold spin polarized atomic vapor, has accelerated the study of cold collisions. Experimental and theoretical studies of BEC and the long range interaction between cold alkali atoms is at the boundary of atomic and low temperature physics. Such studies have been difficult and would not have been possible without the development and advancement of laser cooling and trapping of neutral atoms. By contrast, ion-atom interactions at low temperature, also very difficult to study prior to modern day laser cooling, have remained largely unexplored. But now, many laboratories worldwide have almost routine access to cold neutral atoms. The combined technologies of ion trapping, together with laser cooling of neutrals has made these studies experimentally feasible and several very important, novel applications might come out of such investigations . This paper is an investigation of ion-atom interactions in the cold and ultra-cold temperature regime. Some of the collisional ion-atom interactions present at room temperature are very much reduced in the low temperature regime. Reaction rates for charge transfer between unlike atoms, A + B(+) approaches A(+) + B, are expected to fall rapidly with temperature, approximately as T(sup 5/2). Thus, cold mixtures of atoms and ions are expected to coexist for very long times, unlike room temperature mixtures of the same ion-atom combination. Thus, it seems feasible to cool ions via collisions with laser cooled atoms. Many of the conventional collisional interactions

Effects of anisotropic electron-ion interactions in atomic photoelectron angular distributions

NASA Technical Reports Server (NTRS)

Dill, D.; Starace, A. F.; Manson, S. T.

1974-01-01

The photoelectron asymmetry parameter beta in LS-coupling is obtained as an expansion into contributions from alternative angular momentum transfers j sub t. The physical significance of this expansion of beta is shown to be that: (1) the electric dipole interaction transfers to the atom a charcteristic single angular momentum j sub t = sub o, where sub o is the photoelectron's initial orbital momentum; and (2) angular momentum transfers indicate the presence of anisotropic interaction of the outgoing photoelectron with the residual ion. For open shell atoms the photoelectron-ion interaction is generally anisotropic; photoelectron phase shifts and electric dipole matrix elements depend on both the multiplet term of the residual ion and the total orbital momentum of the ion-photoelectron final state channel. Consequently beta depends on the term levels of the residual ion and contains contributions from all allowed values of j sub t. Numerical calculations of the asymmetry parameters and partial cross sections for photoionization of atomic sulfur are presented.

Anion photoelectron imaging spectroscopy of glyoxal

NASA Astrophysics Data System (ADS)

Xue, Tian; Dixon, Andrew R.; Sanov, Andrei

2016-09-01

We report a photoelectron imaging study of the radical-anion of glyoxal. The 532 nm photoelectron spectrum provides the first direct spectroscopic determination of the adiabatic electron affinity of glyoxal, EA = 1.10 ± 0.02 eV. This assignment is supported by a Franck-Condon simulation of the experimental spectrum that successfully reproduces the observed spectral features. The vertical detachment energy of the radical-anion is determined as VDE = 1.30 ± 0.04 eV. The reported EA and VDE values are attributed to the most stable (C2h symmetry) isomers of the neutral and the anion.

Auroral and photoelectron fluxes in cometary ionospheres

NASA Astrophysics Data System (ADS)

Bhardwaj, A.; Haider, S. A.; Spinghal, R. P.

1990-05-01

The analytical yield spectrum method has been used to ascertain photoelectron and auroral electron fluxes in cometary ionospheres, with a view to determining the effects of cometocentric distances, solar zenith angle, and solar minimum and maximum conditions. Auroral electron fluxes are thus calculated for monoenergetic and observed primary electron spectra; auroral electrons are found to make a larger contribution to the observed electron spectrum than EUV-generated photoelectrons. Good agreement is established with extant theoretical works.

Anion photoelectron spectroscopy of radicals and clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Travis, Taylor R.

1999-12-01

Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying 2Σ and 2π states of C 2nH (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C 2H and C 4H. Other radicals studied include NCN and I 3. The author was able to observe the low-lying singlet and triplet states of NCNmore » for the first time. Measurement of the electron affinity of I 3 revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.« less

Long-Range Coulomb Effect in Intense Laser-Driven Photoelectron Dynamics.

PubMed

Quan, Wei; Hao, XiaoLei; Chen, YongJu; Yu, ShaoGang; Xu, SongPo; Wang, YanLan; Sun, RenPing; Lai, XuanYang; Wu, ChengYin; Gong, QiHuang; He, XianTu; Liu, XiaoJun; Chen, Jing

2016-06-03

In strong field atomic physics community, long-range Coulomb interaction has for a long time been overlooked and its significant role in intense laser-driven photoelectron dynamics eluded experimental observations. Here we report an experimental investigation of the effect of long-range Coulomb potential on the dynamics of near-zero-momentum photoelectrons produced in photo-ionization process of noble gas atoms in intense midinfrared laser pulses. By exploring the dependence of photoelectron distributions near zero momentum on laser intensity and wavelength, we unambiguously demonstrate that the long-range tail of the Coulomb potential (i.e., up to several hundreds atomic units) plays an important role in determining the photoelectron dynamics after the pulse ends.

Long-Range Coulomb Effect in Intense Laser-Driven Photoelectron Dynamics

PubMed Central

Quan, Wei; Hao, XiaoLei; Chen, YongJu; Yu, ShaoGang; Xu, SongPo; Wang, YanLan; Sun, RenPing; Lai, XuanYang; Wu, ChengYin; Gong, QiHuang; He, XianTu; Liu, XiaoJun; Chen, Jing

2016-01-01

In strong field atomic physics community, long-range Coulomb interaction has for a long time been overlooked and its significant role in intense laser-driven photoelectron dynamics eluded experimental observations. Here we report an experimental investigation of the effect of long-range Coulomb potential on the dynamics of near-zero-momentum photoelectrons produced in photo-ionization process of noble gas atoms in intense midinfrared laser pulses. By exploring the dependence of photoelectron distributions near zero momentum on laser intensity and wavelength, we unambiguously demonstrate that the long-range tail of the Coulomb potential (i.e., up to several hundreds atomic units) plays an important role in determining the photoelectron dynamics after the pulse ends. PMID:27256904

X-ray Photoelectron Spectroscopy of High-κ Dielectrics

NASA Astrophysics Data System (ADS)

Mathew, A.; Demirkan, K.; Wang, C.-G.; Wilk, G. D.; Watson, D. G.; Opila, R. L.

2005-09-01

Photoelectron spectroscopy is a powerful technique for the analysis of gate dielectrics because it can determine the elemental composition, the chemical states, and the compositional depth profiles non-destructively. The sampling depth, determined by the escape depth of the photoelectrons, is comparable to the thickness of current gate oxides. A maximum entropy algorithm was used to convert photoelectron collection angle dependence of the spectra to compositional depth profiles. A nitrided hafnium silicate film is used to demonstrate the utility of the technique. The algorithm balances deviations from a simple assumed depth profile against a calculated depth profile that best fits the angular dependence of the photoelectron spectra. A flow chart of the program is included in this paper. The development of the profile is also shown as the program is iterated. Limitations of the technique include the electron escape depths and elemental sensitivity factors used to calculate the profile. The technique is also limited to profiles that extend to the depth of approximately twice the escape depth. These limitations restrict conclusions to comparison among a family of similar samples. Absolute conclusions about depths and concentrations must be used cautiously. Current work to improve the algorithm is also described.

Statistical observations of martian 20-30 eV photoelectrons by MAVEN/SWEA

NASA Astrophysics Data System (ADS)

Garnier, P.; Steckiewicz, M.; Andre, N.; Mazelle, C. X.; Sauvaud, J. A.; Sakai, S.; Cravens, T.; Mitchell, D. L.; Lillis, R. J.; Espley, J. R.; Brain, D.; Andersson, L.; Jakosky, B. M.

2016-12-01

Photoelectron peaks in the 20-30 eV energy range are commonly observed in planetary atmospheres, produced by intense photoionization from solar 30.4 nm photons. At Mars, these photoelectrons are known to escape the planet down its tail (Frahm et al., 2006). Assuming overall charge neutrality, the number of corresponding electrons must be identical to the number of ion charges escaping the planet. Studying the photoelectrons is thus important to understand and quantify the erosion of the martian atmosphere. Moreover, the photoelectrons also play a significant role for the heating and ionization of the atmosphere. The MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft has provided detailed observations of the Martian environment for the last two years thanks to its unique orbital coverage and comprehensive plasma instrument suite. The low periapsis altitudes (down to 125 km altitude) and combined presence of an electron spectrometer (Solar Wind Electron Analyzer, SWEA) and of a magnetometer (MAG) provide a unique opportunity to investigate the source region of the photoelectrons and their transport and escape down the tail. We will present statistical results of an automatic detection of 20-30 eV photoelectrons at Mars, based on a simple algorithm using three levels of confidence. More than 150,000 spectra (each averaged over 30s) revealed clear photoelectron peaks from October 2014 to May 2016. The analysis reveals several interesting features such as: the evolution of the peak shape from their source region to higher altitudes, the influence of the magnetic field topology on photoelectron transport, a clear dusk-dawn asymmetry in agreement with the recently-discovered neutral density asymmetry, the statistical influence of the EUV and solar wind parameters and the location of the photoelectron boundary. These results will also be compared with an electron transport code (Sakai et al., 2015, 2016) to better constrain the photoelectron production and transport.

Charge transfer from an adsorbed ruthenium-based photosensitizer through an ultra-thin aluminium oxide layer and into a metallic substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gibson, Andrew J.; Temperton, Robert H.; Handrup, Karsten

2014-06-21

The interaction of the dye molecule N3 (cis-bis(isothiocyanato)bis(2,2-bipyridyl-4,4′-dicarbo-xylato) -ruthenium(II)) with the ultra-thin oxide layer on a AlNi(110) substrate, has been studied using synchrotron radiation based photoelectron spectroscopy, resonant photoemission spectroscopy, and near edge X-ray absorption fine structure spectroscopy. Calibrated X-ray absorption and valence band spectra of the monolayer and multilayer coverages reveal that charge transfer is possible from the molecule to the AlNi(110) substrate via tunnelling through the ultra-thin oxide layer and into the conduction band edge of the substrate. This charge transfer mechanism is possible from the LUMO+2 and 3 in the excited state but not from the LUMO,more » therefore enabling core-hole clock analysis, which gives an upper limit of 6.0 ± 2.5 fs for the transfer time. This indicates that ultra-thin oxide layers are a viable material for use in dye-sensitized solar cells, which may lead to reduced recombination effects and improved efficiencies of future devices.« less

CRF-PEPICO: Double velocity map imaging photoelectron photoion coincidence spectroscopy for reaction kinetics studies

NASA Astrophysics Data System (ADS)

Sztáray, Bálint; Voronova, Krisztina; Torma, Krisztián G.; Covert, Kyle J.; Bodi, Andras; Hemberger, Patrick; Gerber, Thomas; Osborn, David L.

2017-07-01

Photoelectron photoion coincidence (PEPICO) spectroscopy could become a powerful tool for the time-resolved study of multi-channel gas phase chemical reactions. Toward this goal, we have designed and tested electron and ion optics that form the core of a new PEPICO spectrometer, utilizing simultaneous velocity map imaging for both cations and electrons, while also achieving good cation mass resolution through space focusing. These optics are combined with a side-sampled, slow-flow chemical reactor for photolytic initiation of gas-phase chemical reactions. Together with a recent advance that dramatically increases the dynamic range in PEPICO spectroscopy [D. L. Osborn et al., J. Chem. Phys. 145, 164202 (2016)], the design described here demonstrates a complete prototype spectrometer and reactor interface to carry out time-resolved experiments. Combining dual velocity map imaging with cation space focusing yields tightly focused photoion images for translationally cold neutrals, while offering good mass resolution for thermal samples as well. The flexible optics design incorporates linear electric fields in the ionization region, surrounded by dual curved electric fields for velocity map imaging of ions and electrons. Furthermore, the design allows for a long extraction stage, which makes this the first PEPICO experiment to combine ion imaging with the unimolecular dissociation rate constant measurements of cations to detect and account for kinetic shifts. Four examples are shown to illustrate some capabilities of this new design. We recorded the threshold photoelectron spectrum of the propargyl and the iodomethyl radicals. While the former agrees well with a literature threshold photoelectron spectrum, we have succeeded in resolving the previously unobserved vibrational structure in the latter. We have also measured the bimolecular rate constant of the CH2I + O2 reaction and observed its product, the smallest Criegee intermediate, CH2OO. Finally, the second

Kinetic study of GeO disproportionation into a GeO{sub 2}/Ge system using x-ray photoelectron spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Shengkai; Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656; CREST, Japan Science and Technology Agency

2012-08-06

GeO disproportionation into GeO{sub 2} and Ge is studied through x-ray photoelectron spectroscopy. Direct evidence for the reaction 2GeO {yields} GeO{sub 2} + Ge after annealing in ultra-high vacuum is presented. Activation energy for GeO disproportionation is found to be about 0.7 {+-} 0.2 eV through kinetic and thermodynamic calculations. A kinetic model of GeO disproportionation is established by considering oxygen transfer in the GeO network. The relationship between GeO disproportionation and GeO desorption induced by GeO{sub 2}/Ge interfacial reaction is discussed, and the apparent contradiction between GeO desorption via interfacial redox reaction and GeO disproportionation into Ge and GeO{submore » 2} is explained by considering the oxygen vacancy.« less

Molybdenum disulfide for ultra-low detection of free radicals: electrochemical response and molecular modeling

NASA Astrophysics Data System (ADS)

Gupta, Ankur; Rawal, Takat B.; Neal, Craig J.; Das, Soumen; Rahman, Talat S.; Seal, Sudipta

2017-06-01

Two-dimensional (2D) molybdenum disulfide (MoS2) offers attractive properties due to its band gap modulation and has led to significant research-oriented applications (i.e. DNA and protein detection, cell imaging (fluorescent label) etc.). In biology, detection of free radicals (i.e. reactive oxygen species and reactive nitrogen (NO*) species are very important for early discovery and treatment of diseases. Herein, for the first time, we demonstrate the ultra-low (pico-molar) detection of pharmaceutically relevant free radicals using MoS2 for electrochemical sensing. We present pico- to nano- molar level sensitivity in smaller MoS2 with S-deficiency as revealed by x-ray photoelectron spectroscopy. Furthermore, the detection mechanism and size-dependent sensitivity have been investigated by density functional theory (DFT) showing the change in electronic density of states of Mo atoms at edges which lead to the preferred adsorption of H2O2 on Mo edges. The DFT analysis signifies the role of size and S-deficiency in the higher catalytic activity of smaller MoS2 particles and, thus, ultra-low detection.

Ultra-high vacuum compatible preparation chain for intermetallic compounds

NASA Astrophysics Data System (ADS)

Bauer, A.; Benka, G.; Regnat, A.; Franz, C.; Pfleiderer, C.

2016-11-01

We report the development of a versatile material preparation chain for intermetallic compounds, which focuses on the realization of a high-purity growth environment. The preparation chain comprises an argon glovebox, an inductively heated horizontal cold boat furnace, an arc melting furnace, an inductively heated rod casting furnace, an optically heated floating-zone furnace, a resistively heated annealing furnace, and an inductively heated annealing furnace. The cold boat furnace and the arc melting furnace may be loaded from the glovebox by means of a load-lock permitting to synthesize compounds starting with air-sensitive elements while handling the constituents exclusively in an inert gas atmosphere. All furnaces are all-metal sealed, bakeable, and may be pumped to ultra-high vacuum. We find that the latter represents an important prerequisite for handling compounds with high vapor pressure under high-purity argon atmosphere. We illustrate the operational aspects of the preparation chain in terms of the single-crystal growth of the heavy-fermion compound CeNi2Ge2.

Rhabdomyolysis and exercise-associated hyponatremia in ultra-bikers and ultra-runners.

PubMed

Chlíbková, Daniela; Knechtle, Beat; Rosemann, Thomas; Tomášková, Ivana; Novotný, Jan; Žákovská, Alena; Uher, Tomáš

2015-01-01

Exercise-associated hyponatremia (EAH), rhabdomyolysis and renal failure appear to be a unique problem in ultra-endurance racers. We investigated the combined occurrence of EAH and rhabdomyolysis in seven different ultra-endurance races and disciplines (i.e. multi-stage mountain biking, 24-h mountain biking, 24-h ultra-running and 100-km ultra-running). Two (15.4%) ultra-runners (man and woman) from hyponatremic ultra-athletes (n = 13) and four (4%) ultra-runners (four men) from the normonatremic group (n = 100) showed rhabdomyolysis following elevated blood creatine kinase (CK) levels > 10,000 U/L without the development of renal failure and the necessity of a medical treatment. Post-race creatine kinase, plasma and urine creatinine significantly increased, while plasma [Na(+)] and creatine clearance decreased in hyponatremic and normonatremic athletes, respectively. The percentage increase of CK was higher in the hyponatremic compared to the normonatremic group (P < 0.05). Post-race CK levels were higher in ultra-runners compared to mountain bikers (P < 0.01), in faster normonatremic (P < 0.05) and older and more experienced hyponatremic ultra-athletes (P < 0.05). In all finishers, pre-race plasma [K(+)] was related to post-race CK (P < 0.05). Hyponatremic ultra-athletes tended to develop exercise-induced rhabdomyolysis more frequently than normonatremic ultra-athletes. Ultra-runners tended to develop rhabdomyolysis more frequently than mountain bikers. We found no association between post-race plasma [Na(+)] and CK concentration in both hypo- and normonatremic ultra-athletes.

Photoelectron Effects on the Self-Consistent Potential in the Collisionless Polar Wind

NASA Technical Reports Server (NTRS)

Khazanov, G. V.; Liemohn, M. W.; Moore, T. E.

1997-01-01

The presence of unthermalized photoelectrons in the sunlit polar cap leads to an enhanced ambipolar potential drop and enhanced upward ion acceleration. Observations in the topside ionosphere have led to the conclusion that large-scale electrostatic potential drops exist above the spacecraft along polar magnetic field lines connected to regions of photoelectron production. A kinetic approach is used for the O(+), H(+), and photoelectron (p) distributions, while a fluid approach is used to describe the thermal electrons (e) and self-consistent electric field (E(sub II)) electrons are allowed to carry a flux that compensates for photoelectron escape, a critical assumption. Collisional processes are excluded, leading to easier escape of polar wind particles and therefore to the formation of the largest potential drop consistent with this general approach. We compute the steady state electric field enhancement and net potential drop expected in the polar wind due to the presence of photoelectrons as a function of the fractional photoelectron content and the thermal plasma characteristics. For a set of low-altitude boundary conditions typical of the polar wind ionosphere, including 0.1% photoelectron content, we found a potential drop from 500 km to 5 R(sub E) of 6.5 V and a maximum thermal electron temperature of 8800 K. The reasonable agreement of our results with the observed polar wind suggests that the assumptions of this approach are valid.

Miniaturized Lab System for Future Cold Atom Experiments in Microgravity

NASA Astrophysics Data System (ADS)

Kulas, Sascha; Vogt, Christian; Resch, Andreas; Hartwig, Jonas; Ganske, Sven; Matthias, Jonas; Schlippert, Dennis; Wendrich, Thijs; Ertmer, Wolfgang; Maria Rasel, Ernst; Damjanic, Marcin; Weßels, Peter; Kohfeldt, Anja; Luvsandamdin, Erdenetsetseg; Schiemangk, Max; Grzeschik, Christoph; Krutzik, Markus; Wicht, Andreas; Peters, Achim; Herrmann, Sven; Lämmerzahl, Claus

2017-02-01

We present the technical realization of a compact system for performing experiments with cold 87Rb and 39K atoms in microgravity in the future. The whole system fits into a capsule to be used in the drop tower Bremen. One of the advantages of a microgravity environment is long time evolution of atomic clouds which yields higher sensitivities in atom interferometer measurements. We give a full description of the system containing an experimental chamber with ultra-high vacuum conditions, miniaturized laser systems, a high-power thulium-doped fiber laser, the electronics and the power management. In a two-stage magneto-optical trap atoms should be cooled to the low μK regime. The thulium-doped fiber laser will create an optical dipole trap which will allow further cooling to sub- μK temperatures. The presented system fulfills the demanding requirements on size and power management for cold atom experiments on a microgravity platform, especially with respect to the use of an optical dipole trap. A first test in microgravity, including the creation of a cold Rb ensemble, shows the functionality of the system.

Analysis of photoelectron effect on the antenna impedance via Particle-In-Cell simulation

NASA Astrophysics Data System (ADS)

Miyake, Y.; Usui, H.

2008-08-01

We present photoelectron effects on the impedance of electric field antennas used for plasma wave investigations. To illustrate the photoelectron effects, we applied electromagnetic Particle-In-Cell simulation to the self-consistent antenna impedance analysis. We confirmed the formation of a dense photoelectron region around the sunlit surfaces of the antenna and the spacecraft. The dense photoelectrons enhance the real part, and decrease the absolute value of the imaginary part, of antenna impedance at low frequencies. We also showed that the antenna conductance can be analytically calculated from simulation results of the electron current flowing into or out of the antenna. The antenna impedance in the photoelectron environment is represented by a parallel equivalent circuit consisting of a capacitance and a resistance, which is consistent with empirical knowledge. The results also imply that the impedance varies with the spin of the spacecraft, which causes the variation of the photoelectron density around the antenna.

Increased photoelectron transmission in High-pressure photoelectron spectrometers using "swift acceleration"

NASA Astrophysics Data System (ADS)

Edwards, Mårten O. M.; Karlsson, Patrik G.; Eriksson, Susanna K.; Hahlin, Maria; Siegbahn, Hans; Rensmo, Håkan; Kahk, Juhan M.; Villar-Garcia, Ignacio J.; Payne, David J.; Åhlund, John

2015-06-01

A new operation mode of a HPXPS (high-pressure X-ray photoelectron spectroscopy) analyzer is evaluated on a HPXPS system fitted with an Al Kα X-ray source. A variety of metal foil samples (gold, silver and copper) were measured in different sample gas environments (N2 and H2O), and a front aperture diameter of 0.8 mm. The new design concept is based upon "swiftly" accelerating the photoelectrons to kinetic energies of several keV after they pass the analyzer front aperture. Compared to the standard mode, in which the front section between the two first apertures is field-free, this gives a wider angular collection and a lower tendency for electron losses in collisions with gas molecules within the analyzer. With the swift-acceleration mode we attain, depending on the experimental conditions, up to about 3 times higher peak intensities in vacuum and about 10 to 20 times higher peak intensities in the 6-9 mbar regime, depending on kinetic energy. These experimental findings agree well with simulated transmission functions for the analyzer. The new mode of operation enables faster data acquisition than the standard mode of operation, particularly valuable in a home laboratory environment. Further demonstrations of performance are highlighted by measurements of the valence band structure in dye-sensitized solar cell photoelectrodes under a 2 mbar H2O atmosphere, a molecularly modified surface of interest in photoelectrochemical devices.

Photoelectron wave function in photoionization: plane wave or Coulomb wave?

PubMed

Gozem, Samer; Gunina, Anastasia O; Ichino, Takatoshi; Osborn, David L; Stanton, John F; Krylov, Anna I

2015-11-19

The calculation of absolute total cross sections requires accurate wave functions of the photoelectron and of the initial and final states of the system. The essential information contained in the latter two can be condensed into a Dyson orbital. We employ correlated Dyson orbitals and test approximate treatments of the photoelectron wave function, that is, plane and Coulomb waves, by comparing computed and experimental photoionization and photodetachment spectra. We find that in anions, a plane wave treatment of the photoelectron provides a good description of photodetachment spectra. For photoionization of neutral atoms or molecules with one heavy atom, the photoelectron wave function must be treated as a Coulomb wave to account for the interaction of the photoelectron with the +1 charge of the ionized core. For larger molecules, the best agreement with experiment is often achieved by using a Coulomb wave with a partial (effective) charge smaller than unity. This likely derives from the fact that the effective charge at the centroid of the Dyson orbital, which serves as the origin of the spherical wave expansion, is smaller than the total charge of a polyatomic cation. The results suggest that accurate molecular photoionization cross sections can be computed with a modified central potential model that accounts for the nonspherical charge distribution of the core by adjusting the charge in the center of the expansion.

Observation of circular dichroism in photoelectron angular distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Appling, J.R.; White, M.G.; Orlando, T.M.

1986-12-01

The first observations of dichroic effects in photoelectron angular distributions are reported for photoionization of aligned molecular excited states with circularly polarized light. Photoelectron angular distributions resulting from the two-color, (2+1) REMPI of NO via the A /sup 2/summation/sup +/, v = 0, J = 3/2,5/2 excited states exhibit significant left--right asymmetry. The experimental CD angular distributions are found to be well described by the general theoretical framework recently developed by Dubs, Dixit, and McKoy and are in good qualitative agreement with their calculated REMPI--CD distributions.

Observation of circular dichroism in photoelectron angular distributions

NASA Astrophysics Data System (ADS)

Appling, Jeffrey R.; White, Michael G.; Orlando, Thomas M.; Anderson, Scott L.

1986-12-01

The first observations of dichroic effects in photoelectron angular distributions are reported for photoionization of aligned molecular excited states with circularly polarized light. Photoelectron angular distributions resulting from the two-color, (2+1) REMPI of NO via the A 2∑+, v=0, J=3/2,5/2 excited states exhibit significant left-right asymmetry. The experimental CD angular distributions are found to be well described by the general theoretical framework recently developed by Dubs, Dixit, and McKoy and are in good qualitative agreement with their calculated REMPI-CD distributions.

Particle Simulations of the Guard Electrode Effects on the Photoelectron Distribution Around an Electric Field Sensor

NASA Astrophysics Data System (ADS)

Miyake, Y.; Usui, H.; Kojima, H.

2010-12-01

In tenuous space plasma environment, photoelectrons emitted due to solar illumination produce a high-density photoelectron cloud localized in the vicinity of a spacecraft body and an electric field sensor. The photoelectron current emitted from the sensor has also received considerable attention because it becomes a primary factor in determining floating potentials of the sunlit spacecraft and sensor bodies. Considering the fact that asymmetric photoelectron distribution between sunlit and sunless sides of the spacecraft occasionally causes a spurious sunward electric field, we require quantitative evaluation of the photoelectron distribution around the spacecraft and its influence on electric field measurements by means of a numerical approach. In the current study, we applied the Particle-in-Cell plasma simulation to the analysis of the photoelectron environment around spacecraft. By using the PIC modeling, we can self-consistently consider the plasma kinetics. This enables us to simulate the formation of the photoelectron cloud as well as the spacecraft and sensor charging in a self-consistent manner. We report the progress of an analysis on photoelectron environment around MEFISTO, which is an electric field instrument for the BepiColombo/MMO spacecraft to Mercury’s magnetosphere. The photoelectron guard electrode is a key technology for ensuring an optimum photoelectron environment. We show some simulation results on the guard electrode effects on surrounding photoelectrons and discuss a guard operation condition for producing the optimum photoelectron environment. We also deal with another important issue, that is, how the guard electrode can mitigate an undesirable influence of an asymmetric photoelectron distribution on electric field measurements.

Angular distribution of photoelectrons at 584A using polarized radiation

NASA Technical Reports Server (NTRS)

Hancock, W. H.; Samson, J. A. R.

1975-01-01

Photoelectron angular distributions for Ar, Xe, N2, O2, CO, CO2, and NH3 were obtained at 584 A by observing the photoelectrons at a fixed angle and simply rotating the plane of polarization of a highly polarized photon source. The radiation from a helium dc glow discharge source was polarized (84%) using a reflection type polarizer.

Renner-Teller effects in the photoelectron spectra of CNC, CCN, and HCCN.

PubMed

Coudert, Laurent H; Gans, Bérenger; Garcia, Gustavo A; Loison, Jean-Christophe

2018-02-07

The line intensity of photoelectron spectra when either the neutral or cationic species display a Renner-Teller coupling is derived and applied to the modeling of the photoelectron spectra of CNC, CCN, and HCCN. The rovibronic energy levels of these three radicals and of their cations are investigated starting from ab initio results. A model treating simultaneously the bending mode and the overall rotation is developed to deal with the quasilinearity problem in CNC + , CCN + , and HCCN and accounts for the large amplitude nature of their bending mode. This model is extended to treat the Renner-Teller coupling in CNC, CCN, and HCCN + . Based on the derived photoelectron line intensity, the photoelectron spectra of all three molecules are calculated and compared to the experimental ones.

The PhotoElectron Boundary as observed by MAVEN instruments

NASA Astrophysics Data System (ADS)

Garnier, P.; Steckiewicz, M.; Mazelle, C. X.; Xu, S.; Mitchell, D. L.; Holmberg, M.; Halekas, J. S.; Andersson, L.; Brain, D.; Connerney, J. E. P.; Espley, J. R.; Lillis, R. J.; Luhmann, J. G.; Savaud, J. A.; Jakosky, B. M.

2017-12-01

Photoelectron peaks in the 20-30 eV energy range are commonly observed in planetary atmospheres (Earth, Mars, Titan...), produced by the intense photoionization from solar 30.4 nm photons. At Mars, these photoelectrons result from the ionization of CO2 and O atmospheric neutrals, and are known to escape the planet down its tail, making them tracers for the atmospheric escape (Frahm et al., 2006). Furthermore, their presence or absence allows us to define the so-called PhotoElectron Boundary (PEB), that separates the sunlit photoelectron-dominated ionosphere from the solar wind controlled environment, as initially observed by the Mars Global Surveyor (MGS) MAG/ER instrument (Mitchell et al. (2000, 2001). We provide here a detailed statistical analysis of the location and properties of the PEB based on the Mars Atmosphere and Volatile Evolution (MAVEN) mission electron and magnetic field data. Our dataset includes 1696 dayside PEB crossings obtained from September 2014 until May 2016 (the observations of escaping photoelectrons in the wake being not included). The PEB appears as mostly sensitive to the solar wind dynamic and crustal magnetic fields pressures, for which a quantitative dependance is derived and compared with two other important boundaries : the bow shock and magnetic pileup boundary. The PEB altitude is highly variable, leading to a variable wake cross section for escape (up to +- 50%), which is important for deriving global escape rates from in situ photoelectron escape rates. The PEB is not always sharp, and is, despite a strong variability, characterized on average by : a magnetic field topology typical for the edge of the Magnetic Pile Up Region above it, more field aligned fluxes above than below, and a clear change of the altitude dependence of both electron fluxes and total density (that appears different from the ionopause). The PEB thus appears as a transition region between two plasma and field configurations which is determined by the

The Martian Photoelectron Boundary as Seen by MAVEN

NASA Astrophysics Data System (ADS)

Garnier, P.; Steckiewicz, M.; Mazelle, C.; Xu, S.; Mitchell, D.; Holmberg, M. K. G.; Halekas, J. S.; Andersson, L.; Brain, D. A.; Connerney, J. E. P.; Espley, J. R.; Lillis, R. J.; Luhmann, J. G.; Sauvaud, J.-A.; Jakosky, B. M.

2017-10-01

Photoelectron peaks in the 20-30 eV energy range are commonly observed in the planetary atmospheres, produced by the intense photoionization from solar 30.4 nm photons. At Mars, these photoelectrons are known to escape the planet down its tail, making them tracers for the atmospheric escape. Furthermore, their presence or absence allow to define the so-called photoelectron boundary (PEB), which separates the photoelectron dominated ionosphere from the external environment. We provide here a detailed statistical analysis of the location and properties of the PEB based on the Mars Atmosphere and Volatile EvolutioN (MAVEN) electron and magnetic field data obtained from September 2014 to May 2016 (including 1696 PEB crossings). The PEB appears as mostly sensitive to the solar wind dynamic and crustal fields pressures. Its variable altitude thus leads to a variable wake cross section for escape (up to ˜+50%), which is important for deriving escape rates. The PEB is not always sharp and is characterized on average by the following: a magnetic field topology typical for the end of magnetic pileup region above it, more field-aligned fluxes above than below, and a clear change of the altitude slopes of both electron fluxes and total density (that appears different from the ionopause). The PEB thus appears as a transition region between two plasma and fields configurations determined by the draping topology of the interplanetary magnetic field around Mars and much influenced by the crustal field sources below, whose dynamics also impacts the estimated escape rate of ionospheric plasma.

Photoelectron Imaging Spectroscopy as a Window to Unexpected Molecules

NASA Astrophysics Data System (ADS)

Blackstone, Christopher C.

2017-06-01

Targeting an anion with the formula CH_{3}O_{3} for exploration with photoelectron imaging spectroscopy, we determine its identity to be dihydroxymethanolate, an anion largely absent in the literature, and the conjugate base of the hypothetical species orthoformic acid. Comparing the observed photoelectron spectrum to CCSD-EOM-IP and CCSD-EOM-SF calculations completed in QChem and Franck-Condon overlap simulations in PESCAL, we are able to determine with confidence the connectivity of the atoms in this molecule.

Photoelectron angular distribution from free SiO2 nanoparticles as a probe of elastic electron scattering.

PubMed

Antonsson, E; Langer, B; Halfpap, I; Gottwald, J; Rühl, E

2017-06-28

In order to gain quantitative information on the surface composition of nanoparticles from X-ray photoelectron spectroscopy, a detailed understanding of photoelectron transport phenomena in these samples is needed. Theoretical results on the elastic and inelastic scattering have been reported, but a rigorous experimental verification is lacking. We report in this work on the photoelectron angular distribution from free SiO 2 nanoparticles (d = 122 ± 9 nm) after ionization by soft X-rays above the Si 2p and O 1s absorption edges, which gives insight into the relative importance of elastic and inelastic scattering channels in the sample particles. The photoelectron angular anisotropy is found to be lower for photoemission from SiO 2 nanoparticles than that expected from the theoretical values for the isolated Si and O atoms in the photoelectron kinetic energy range 20-380 eV. The reduced angular anisotropy is explained by elastic scattering of the outgoing photoelectrons from neighboring atoms, smearing out the atomic distribution. Photoelectron angular distributions yield detailed information on photoelectron elastic scattering processes allowing for a quantification of the number of elastic scattering events the photoelectrons have undergone prior to leaving the sample. The interpretation of the experimental photoelectron angular distributions is complemented by Monte Carlo simulations, which take inelastic and elastic photoelectron scattering into account using theoretical values for the scattering cross sections. The results of the simulations reproduce the experimental photoelectron angular distributions and provide further support for the assignment that elastic and inelastic electron scattering processes need to be considered.

Photoelectrons in the Quiet Polar Wind

NASA Technical Reports Server (NTRS)

Glocer, A.; Khazanov, G.; Liemohn, M.

2017-01-01

This study presents a newly coupled model capable of treating the superthermal electron population in the global polar wind solution. The model combines the hydrodynamic Polar Wind Outflow Model (PWOM) with the kinetic SuperThermal Electron Transport (STET) code. The resulting PWOM-STET coupled model is described and then used to investigate the role of photoelectrons in the polar wind. We present polar wind results along single stationary field lines under dayside and nightside conditions, as well as the global solution reconstructed from nearly 1000 moving field lines. The model results show significant day-night asymmetries in the polar wind solution owing to the higher ionization and photoelectron fluxes on the dayside compared to the nightside. Field line motion is found to modify this dependence and create global structure by transporting field lines through different conditions of illumination and through the localized effects of Joule heating.

Activation of the E1 Ultra High Pressure Propulsion Test Facility at Stennis Space Center

NASA Technical Reports Server (NTRS)

Messer, Bradley; Messer, Elisabeth; Sewell, Dale; Sass, Jared; Lott, Jeff; Dutreix, Lionel, III

2001-01-01

After a decade of construction and a year of activation the El Ultra High Pressure Propulsion Test Facility at NASA's Stennis Space Center is fully operational. The El UHP Propulsion Test Facility is a multi-cell, multi-purpose component and engine test facility . The facility is capable of delivering cryogenic propellants at low, high, and ultra high pressures with flow rates ranging from a few pounds per second up to two thousand pounds per second. Facility activation is defined as a series of tasks required to transition between completion of construction and facility operational readiness. Activating the El UHP Propulsion Test Facility involved independent system checkouts, propellant system leak checks, fluid and gas sampling, gaseous system blow downs, pressurization and vent system checkouts, valve stability testing, valve tuning cryogenic cold flows, and functional readiness tests.

Ultra-high vacuum surface analysis study of rhodopsin incorporation into supported lipid bilayers.

PubMed

Michel, Roger; Subramaniam, Varuni; McArthur, Sally L; Bondurant, Bruce; D'Ambruoso, Gemma D; Hall, Henry K; Brown, Michael F; Ross, Eric E; Saavedra, S Scott; Castner, David G

2008-05-06

Planar supported lipid bilayers that are stable under ambient atmospheric and ultra-high-vacuum conditions were prepared by cross-linking polymerization of bis-sorbylphosphatidylcholine (bis-SorbPC). X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to investigate bilayers that were cross-linked using either redox-initiated radical polymerization or ultraviolet photopolymerization. The redox method yields a more structurally intact bilayer; however, the UV method is more compatible with incorporation of transmembrane proteins. UV polymerization was therefore used to prepare cross-linked bilayers with incorporated bovine rhodopsin, a light-activated, G-protein-coupled receptor (GPCR). A previous study (Subramaniam, V.; Alves, I. D.; Salgado, G. F. J.; Lau, P. W.; Wysocki, R. J.; Salamon, Z.; Tollin, G.; Hruby, V. J.; Brown, M. F.; Saavedra, S. S. J. Am. Chem. Soc. 2005, 127, 5320-5321) showed that rhodopsin retains photoactivity after incorporation into UV-polymerized bis-SorbPC, but did not address how the protein is associated with the bilayer. In this study, we show that rhodopsin is retained in supported bilayers of poly(bis-SorbPC) under ultra-high-vacuum conditions, on the basis of the increase in the XPS nitrogen concentration and the presence of characteristic amino acid peaks in the ToF-SIMS data. Angle-resolved XPS data show that the protein is inserted into the bilayer, rather than adsorbed on the bilayer surface. This is the first study to demonstrate the use of ultra-high-vacuum techniques for structural studies of supported proteolipid bilayers.

Low temperature growth of ultra-high mass density carbon nanotube forests on conductive supports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugime, Hisashi; Esconjauregui, Santiago; Yang, Junwei

2013-08-12

We grow ultra-high mass density carbon nanotube forests at 450 °C on Ti-coated Cu supports using Co-Mo co-catalyst. X-ray photoelectron spectroscopy shows Mo strongly interacts with Ti and Co, suppressing both aggregation and lifting off of Co particles and, thus, promoting the root growth mechanism. The forests average a height of 0.38 μm and a mass density of 1.6 g cm{sup −3}. This mass density is the highest reported so far, even at higher temperatures or on insulators. The forests and Cu supports show ohmic conductivity (lowest resistance ∼22 kΩ), suggesting Co-Mo is useful for applications requiring forest growth onmore » conductors.« less

Production, Thermalization and Transport of Photoelectrons in the Mars Environment

NASA Astrophysics Data System (ADS)

Mitchell, D. L.; Xu, S.; Mazelle, C. X.; Steckiewicz, M.; Luhmann, J. G.; Connerney, J. E. P.; Andersson, L.

2016-12-01

The Solar Wind Electron Analyzer (SWEA) on the MAVEN spacecraft provides a detailed look at the production, thermalization, and transport of photoelectrons in the Mars environment. The MAVEN orbit routinely samples altitudes down to 150 km over wide ranges of solar zenith angle, local time, longitude, latitude and altitude. The altitude range extends into the region of photochemical equilibrium. SWEA's nominal energy resolution of 17% (ΔE/E, FWHM) is insufficient to resolve the photoelectron peaks at 23 and 27 eV, which result from photoionization of CO2 and O by the intense He II line in the solar EUV spectrum. However, during some orbits the spacecraft charged to -18 V near periapsis, which shifted the He II photoelectron features to lower energies, thus allowing them to be resolved. During several week-long deep dip campaigns, the periapsis altitude was lowered to 120 km. Thermalization of primary photoelectrons is very rapid at this altitude, resulting in a residual population at 7 eV, where the cross section to interaction with CO2 has a minimum. At altitudes above the 200 km, collisions become negligible (mean free path > 100 km), and the motion of suprathermal electrons is controlled by the magnetic field. Electron energy-pitch angle distributions reveal transport of photoelectrons from the day to the night hemisphere on both closed crustal magnetic loops and on open lines that extend into the tail. Mapping of such open field lines reveals the regions of the tail with access to the day-side ionosphere, which provide a conduit for ion outflow and loss.

Titan's plasma interaction: photoelectrons and negative ions

NASA Astrophysics Data System (ADS)

Coates, Coates; Welbrock, Anne; Desai, Ravi; Waite, Hunter

2016-06-01

We present a review of some of the most important results from the CAPS electron spectrometer.These include the role of photoelectrons and polar wind escape processes, and remarkable negative ion observations.

Lithium cluster anions: photoelectron spectroscopy and ab initio calculations.

PubMed

Alexandrova, Anastassia N; Boldyrev, Alexander I; Li, Xiang; Sarkas, Harry W; Hendricks, Jay H; Arnold, Susan T; Bowen, Kit H

2011-01-28

Structural and energetic properties of small, deceptively simple anionic clusters of lithium, Li(n)(-), n = 3-7, were determined using a combination of anion photoelectron spectroscopy and ab initio calculations. The most stable isomers of each of these anions, the ones most likely to contribute to the photoelectron spectra, were found using the gradient embedded genetic algorithm program. Subsequently, state-of-the-art ab initio techniques, including time-dependent density functional theory, coupled cluster, and multireference configurational interactions methods, were employed to interpret the experimental spectra.

X-ray photoelectron spectroscopy of select multi-layered transition metal carbides (MXenes)

NASA Astrophysics Data System (ADS)

Halim, Joseph; Cook, Kevin M.; Naguib, Michael; Eklund, Per; Gogotsi, Yury; Rosen, Johanna; Barsoum, Michel W.

2016-01-01

In this work, a detailed high resolution X-ray photoelectron spectroscopy (XPS) analysis is presented for select MXenes-a recently discovered family of two-dimensional (2D) carbides and carbonitrides. Given their 2D nature, understanding their surface chemistry is paramount. Herein we identify and quantify the surface groups present before, and after, sputter-cleaning as well as freshly prepared vs. aged multi-layered cold pressed discs. The nominal compositions of the MXenes studied here are Ti3C2Tx, Ti2CTx, Ti3CNTx, Nb2CTx and Nb4C3Tx, where T represents surface groups that this work attempts to quantify. In all the cases, the presence of three surface terminations, sbnd O, sbnd OH and sbnd F, in addition to OH-terminations relatively strongly bonded to H2O molecules, was confirmed. From XPS peak fits, it was possible to establish the average sum of the negative charges of the terminations for the aforementioned MXenes. Based on this work, it is now possible to quantify the nature of the surface terminations. This information can, in turn, be used to better design and tailor these novel 2D materials for various applications.

Additive manufacturing of magnetic shielding and ultra-high vacuum flange for cold atom sensors.

PubMed

Vovrosh, Jamie; Voulazeris, Georgios; Petrov, Plamen G; Zou, Ji; Gaber, Youssef; Benn, Laura; Woolger, David; Attallah, Moataz M; Boyer, Vincent; Bongs, Kai; Holynski, Michael

2018-01-31

Recent advances in the understanding and control of quantum technologies, such as those based on cold atoms, have resulted in devices with extraordinary metrological performance. To realise this potential outside of a lab environment the size, weight and power consumption need to be reduced. Here we demonstrate the use of laser powder bed fusion, an additive manufacturing technique, as a production technique relevant to the manufacture of quantum sensors. As a demonstration we have constructed two key components using additive manufacturing, namely magnetic shielding and vacuum chambers. The initial prototypes for magnetic shields show shielding factors within a factor of 3 of conventional approaches. The vacuum demonstrator device shows that 3D-printed titanium structures are suitable for use as vacuum chambers, with the test system reaching base pressures of 5 ± 0.5 × 10 -10 mbar. These demonstrations show considerable promise for the use of additive manufacturing for cold atom based quantum technologies, in future enabling improved integrated structures, allowing for the reduction in size, weight and assembly complexity.

Characterization of a cold-active bacterium isolated from the South Pole “Ice Tunnel”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madigan, Michael T.; Kempher, Megan L.; Bender, Kelly S.

Abstract Extremely cold microbial habitats on Earth (those below -30 °C) are rare and have not been surveyed for microbes as extensively as environments in the 0 to -20 °C range. Using cryoprotected growth media incubated at -5 °C, we enriched a cold-active Pseudomonas species from -50 °C ice collected from a utility tunnel for wastewater pipes under Amundsen–Scott South Pole Station, Antarctica. The isolate, strain UC-1, is related to other cold-active Pseudomonas species, most notably P. psychrophila, and grew at -5 °C to +34–37 °C; growth of UC-1 at +3 °C was significantly faster than at +34 °C. Strainmore » UC-1 synthesized a surface exopolymer and high levels of unsaturated fatty acids under cold growth conditions. A 16S rRNA gene diversity screen of the ice sample that yielded strain UC-1 revealed over 1200 operational taxonomic units (OTUs) distributed across eight major classes of Bacteria. Many of the OTUs were Clostridia and Bacteriodia and some of these were probably of wastewater origin. However, a significant fraction of the OTUs were Proteobacteria and Actinobacteria of likely environmental origin. Our results shed light on the lower temperature limits to life and the possible existence of functional microbial communities in ultra-cold environments.« less

Rovibrational photoionization dynamics of methyl and its isotopomers studied by high-resolution photoionization and photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Schulenburg, A. M.; Alcaraz, Ch.; Grassi, G.; Merkt, F.

2006-09-01

High-resolution photoionization and pulsed-field-ionization zero-kinetic-energy photoelectron spectra of CH3, CH2D, CHD2, and CD3 have been recorded in the vicinity of the first adiabatic ionization threshold following single-photon excitation from the ground neutral state using a narrow-bandwidth vacuum-ultraviolet laser. The radicals were produced from the precursor molecules methyl-bromide, methyl-iodide, dimethyl-thioether, acetone, and nitromethane by 193nm excimer photolysis in a quartz capillary and were subsequently cooled to a rotational temperature Trot≈30K in a supersonic expansion. Nitromethane was identified as a particularly suitable photolytic precursor of methyl for studies by photoionization and threshold photoelectron spectroscopy. Thanks to the cold rotational temperature reached in the supersonic expansion, the rotational structure of the threshold ionization spectra could be resolved, and the photoionization dynamics investigated. Rydberg series converging on excited rotational levels of CH3+ could be observed in the range of principal quantum number n =30-50, and both rotational autoionization and predissociation were identified as decay processes in the threshold region. The observed photoionization transitions can be understood in the realm of an orbital model for direct ionization but the intensity distributions can only be fully accounted for if the rotational channel interactions mediated by the quadrupole of the cation are considered. Improved values of the adiabatic ionization thresholds were derived for all isotopomers [CH3: 79356.2(15)cm-1, CH2D: 79338.8(15)cm-1, CHD2: 79319.1(15)cm-1, and CD3: 79296.4(15)cm-1].

The production and photoelectron spectrum of thiazyl iodide. NSI

NASA Astrophysics Data System (ADS)

Allaf, A. W.; Matti, G. Y.; Suffolk, R. J.; Watts, J. D.

1989-02-01

The previously unknown molecule thiazyl iodide, NSI, has been prepared and studied by HeI photoelectron and low-resolution infrared spectroscopy. It has been produced by an on-line process using thiazyl chloride, NSCl, as precursor. The observed photoelectron spectrum has been rationalised using ab initio molecular-orbital calculations. The first ionisation energy is 10.06±0.05 eV, assigned to a largely non-bonding orbital with major components on nitrogen and iodine. Gas-phase infrared spectra yield a value for ν 1 of 1295 cm -1.

Time-resolved inner-shell photoelectron spectroscopy: From a bound molecule to an isolated atom

NASA Astrophysics Data System (ADS)

Brauße, Felix; Goldsztejn, Gildas; Amini, Kasra; Boll, Rebecca; Bari, Sadia; Bomme, Cédric; Brouard, Mark; Burt, Michael; de Miranda, Barbara Cunha; Düsterer, Stefan; Erk, Benjamin; Géléoc, Marie; Geneaux, Romain; Gentleman, Alexander S.; Guillemin, Renaud; Ismail, Iyas; Johnsson, Per; Journel, Loïc; Kierspel, Thomas; Köckert, Hansjochen; Küpper, Jochen; Lablanquie, Pascal; Lahl, Jan; Lee, Jason W. L.; Mackenzie, Stuart R.; Maclot, Sylvain; Manschwetus, Bastian; Mereshchenko, Andrey S.; Mullins, Terence; Olshin, Pavel K.; Palaudoux, Jérôme; Patchkovskii, Serguei; Penent, Francis; Piancastelli, Maria Novella; Rompotis, Dimitrios; Ruchon, Thierry; Rudenko, Artem; Savelyev, Evgeny; Schirmel, Nora; Techert, Simone; Travnikova, Oksana; Trippel, Sebastian; Underwood, Jonathan G.; Vallance, Claire; Wiese, Joss; Simon, Marc; Holland, David M. P.; Marchenko, Tatiana; Rouzée, Arnaud; Rolles, Daniel

2018-04-01

Due to its element and site specificity, inner-shell photoelectron spectroscopy is a widely used technique to probe the chemical structure of matter. Here, we show that time-resolved inner-shell photoelectron spectroscopy can be employed to observe ultrafast chemical reactions and the electronic response to the nuclear motion with high sensitivity. The ultraviolet dissociation of iodomethane (CH3I ) is investigated by ionization above the iodine 4 d edge, using time-resolved inner-shell photoelectron and photoion spectroscopy. The dynamics observed in the photoelectron spectra appear earlier and are faster than those seen in the iodine fragments. The experimental results are interpreted using crystal-field and spin-orbit configuration interaction calculations, and demonstrate that time-resolved inner-shell photoelectron spectroscopy is a powerful tool to directly track ultrafast structural and electronic transformations in gas-phase molecules.

Characterizing convective cold pools: Characterizing Convective Cold Pools

DOE PAGES

Drager, Aryeh J.; van den Heever, Susan C.

2017-05-09

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

Characterizing convective cold pools: Characterizing Convective Cold Pools

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drager, Aryeh J.; van den Heever, Susan C.

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

Angle-resolved photoelectron spectroscopy of formaldehyde and methanol

NASA Astrophysics Data System (ADS)

Keller, P. R.; Taylor, J. W.; Grimm, F. A.; Carlson, Thomas A.

1984-10-01

Angle-resolved photoelectron spectroscopy was employed to obtain the angular distribution parameter, β, for the valence orbitals (IP < 21.1 eV) of formaldehyde and methanol over the 10-30 eV photon energy range using dispersed polarized synchrotron radiation as the excitation source. It was found that the energy dependence of β in the photoelectron energy range between 2 and 10 eV can be related to the molecular-orbital type from which ionization occurs. This generalized energy behavior is discussed with regard to earlier energy-dependence studies on molecules of different orbital character. Evidence is presented for the presence of resonance photoionization phenomena in formaldehyde in agreement with theoretical cross-section calculations.

Photoelectron circular dichroism in different ionization regimes

NASA Astrophysics Data System (ADS)

Wollenhaupt, Matthias

2016-12-01

Photoelectron circular dichroism (PECD) describes an asymmetry in the photoelectron angular distribution (PAD) from photoionization of randomly oriented enantiomers with circularly polarized light. Beaulieu et al present a comprehensive set of measured PADs from multiphoton ionization of limonene and fenchone in different ionization regimes (multiphoton and tunneling) and analyze the resulting PECD (Beaulieu et al 2016 New J. Phys. 18 102002). From their observations the authors conclude that the PECD is universal in the sense that the molecular chirality is encoded in the PAD independent of the ionization regime. The analysis is supplemented by a classical model based on electron scattering in a chiral potential. The paper presents beautiful data and is an important step towards a more complete physical picture of PECD. The results and their interpretation stimulate the ongoing vivid debate on the role of resonances in multiphoton PECD.

Designing Ratchets in Ultra-cold Atoms for the Advanced Undergraduate Laboratory

NASA Astrophysics Data System (ADS)

Hachtel, Andrew; Gillette, Matthew; Clements, Ethan; Zhong, Shan; Ducay, Rey; Bali, Samir

2014-05-01

We propose to perform ratchet experiments in cold Rubidium atoms using state-of-the-art home-built tapered amplifier and imaging systems. Our tapered amplifier system amplifies the output from home-built external cavity tunable diode lasers up to a factor 100 and costs less than 5,000, in contrast to commercial tapered amplifier systems, which cost upward of 20,000. We have developed an imaging system with LabVIEW integration, which allows for approximately 2 millisecond exposures and microsecond control of experimental parameters. Our imaging system also costs less than 5,000 in comparison to commercial options, which cost between 40-50,000. Progress toward implementation of a one-dimensional rocking ratchet is described. We gratefully acknowledge funding from the American Chemical Society Petroleum Research Fund and Miami University. We also acknowledge the Miami University Instrumentation Laboratory for their invaluable contributions.

SMUVS: Spitzer Matching survey of the UltraVISTA ultra-deep Stripes

NASA Astrophysics Data System (ADS)

Caputi, Karina; Ashby, Matthew; Fazio, Giovanni; Huang, Jiasheng; Dunlop, James; Franx, Marijn; Le Fevre, Olivier; Fynbo, Johan; McCracken, Henry; Milvang-Jensen, Bo; Muzzin, Adam; Ilbert, Olivier; Somerville, Rachel; Wechsler, Risa; Behroozi, Peter; Lu, Yu

2014-12-01

We request 2026.5 hours to homogenize the matching ultra-deep IRAC data of the UltraVISTA ultra-deep stripes, producing a final area of ~0.6 square degrees with the deepest near- and mid-IR coverage existing in any such large area of the sky (H, Ks, [3.6], [4.5] ~ 25.3-26.1 AB mag; 5 sigma). The UltraVISTA ultra-deep stripes are contained within the larger COSMOS field, which has a rich collection of multi-wavelength, ancillary data, making it ideal to study different aspects of galaxy evolution with high statistical significance and excellent redshift accuracy. The UltraVISTA ultra-deep stripes are the region of the COSMOS field where these studies can be pushed to the highest redshifts, but securely identifying high-z galaxies, and determining their stellar masses, will only be possible if ultra-deep mid-IR data are available. Our IRAC observations will allow us to: 1) extend the galaxy stellar mass function at redshifts z=3 to z=5 to the intermediate mass regime (M~5x10^9-10^10 Msun), which is critical to constrain galaxy formation models; 2) gain a factor of six in the area where it is possible to effectively search for z>=6 galaxies and study their properties; 3) measure, for the first time, the large-scale structure traced by an unbiased galaxy sample at z=5 to z=7, and make the link to their host dark matter haloes. This cannot be done in any other field of the sky, as the UltraVISTA ultra-deep stripes form a quasi-contiguous, regular-shape field, which has a unique combination of large area and photometric depth. 4) provide a unique resource for the selection of secure z>5 targets for JWST and ALMA follow up. Our observations will have an enormous legacy value which amply justifies this new observing-time investment in the COSMOS field. Spitzer cannot miss this unique opportunity to open up a large 0.6 square-degree window to the early Universe.

Imaging photoelectron circular dichroism of chiral molecules by femtosecond multiphoton coincidence detection.

PubMed

Lehmann, C Stefan; Ram, N Bhargava; Powis, Ivan; Janssen, Maurice H M

2013-12-21

Here, we provide a detailed account of novel experiments employing electron-ion coincidence imaging to discriminate chiral molecules. The full three-dimensional angular scattering distribution of electrons is measured after photoexcitation with either left or right circular polarized light. The experiment is performed using a simplified photoelectron-photoion coincidence imaging setup employing only a single particle imaging detector. Results are reported applying this technique to enantiomers of the chiral molecule camphor after three-photon ionization by circularly polarized femtosecond laser pulses at 400 nm and 380 nm. The electron-ion coincidence imaging provides the photoelectron spectrum of mass-selected ions that are observed in the time-of-flight mass spectra. The coincident photoelectron spectra of the parent camphor ion and the various fragment ions are the same, so it can be concluded that fragmentation of camphor happens after ionization. We discuss the forward-backward asymmetry in the photoelectron angular distribution which is expressed in Legendre polynomials with moments up to order six. Furthermore, we present a method, similar to one-photon electron circular dichroism, to quantify the strength of the chiral electron asymmetry in a single parameter. The circular dichroism in the photoelectron angular distribution of camphor is measured to be 8% at 400 nm. The electron circular dichroism using femtosecond multiphoton excitation is of opposite sign and about 60% larger than the electron dichroism observed before in near-threshold one-photon ionization with synchrotron excitation. We interpret our multiphoton ionization as being resonant at the two-photon level with the 3s and 3p Rydberg states of camphor. Theoretical calculations are presented that model the photoelectron angular distribution from a prealigned camphor molecule using density functional theory and continuum multiple scattering X alpha photoelectron scattering calculations

Imaging photoelectron circular dichroism of chiral molecules by femtosecond multiphoton coincidence detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehmann, C. Stefan; Ram, N. Bhargava; Janssen, Maurice H. M., E-mail: m.h.m.janssen@vu.nl

2013-12-21

Here, we provide a detailed account of novel experiments employing electron-ion coincidence imaging to discriminate chiral molecules. The full three-dimensional angular scattering distribution of electrons is measured after photoexcitation with either left or right circular polarized light. The experiment is performed using a simplified photoelectron-photoion coincidence imaging setup employing only a single particle imaging detector. Results are reported applying this technique to enantiomers of the chiral molecule camphor after three-photon ionization by circularly polarized femtosecond laser pulses at 400 nm and 380 nm. The electron-ion coincidence imaging provides the photoelectron spectrum of mass-selected ions that are observed in the time-of-flightmore » mass spectra. The coincident photoelectron spectra of the parent camphor ion and the various fragment ions are the same, so it can be concluded that fragmentation of camphor happens after ionization. We discuss the forward-backward asymmetry in the photoelectron angular distribution which is expressed in Legendre polynomials with moments up to order six. Furthermore, we present a method, similar to one-photon electron circular dichroism, to quantify the strength of the chiral electron asymmetry in a single parameter. The circular dichroism in the photoelectron angular distribution of camphor is measured to be 8% at 400 nm. The electron circular dichroism using femtosecond multiphoton excitation is of opposite sign and about 60% larger than the electron dichroism observed before in near-threshold one-photon ionization with synchrotron excitation. We interpret our multiphoton ionization as being resonant at the two-photon level with the 3s and 3p Rydberg states of camphor. Theoretical calculations are presented that model the photoelectron angular distribution from a prealigned camphor molecule using density functional theory and continuum multiple scattering X alpha photoelectron scattering calculations

An analytical investigation: Effect of solar wind on lunar photoelectron sheath

NASA Astrophysics Data System (ADS)

Mishra, S. K.; Misra, Shikha

2018-02-01

The formation of a photoelectron sheath over the lunar surface and subsequent dust levitation, under the influence of solar wind plasma and continuous solar radiation, has been analytically investigated. The photoelectron sheath characteristics have been evaluated using the Poisson equation configured with population density contributions from half Fermi-Dirac distribution of the photoemitted electrons and simplified Maxwellian statistics of solar wind plasma; as a consequence, altitude profiles for electric potential, electric field, and population density within the photoelectron sheath have been derived. The expression for the accretion rate of sheath electrons over the levitated spherical particles using anisotropic photoelectron flux has been derived, which has been further utilized to characterize the charging of levitating fine particles in the lunar sheath along with other constituent photoemission and solar wind fluxes. This estimate of particle charge has been further manifested with lunar sheath characteristics to evaluate the altitude profile of the particle size exhibiting levitation. The inclusion of solar wind flux into analysis is noticed to reduce the sheath span and altitude of the particle levitation; the dependence of the sheath structure and particle levitation on the solar wind plasma parameters has been discussed and graphically presented.

Photoelectron angular distributions from rotationally resolved autoionizing states of N 2

DOE PAGES

Chartrand, A. M.; McCormack, E. F.; Jacovella, U.; ...

2017-12-08

The single-photon, photoelectron-photoion coincidence spectrum of N 2 has been recorded at high (~1.5 cm -1) resolution in the region between the N 2 + X 2Σ g +, v + = 0 and 1 ionization thresholds by using a double imaging spectrometer and intense vacuum-ultraviolet light from the Synchrotron SOLEIL. This approach provides the relative photoionization cross section, the photoelectron energy distribution, and the photoelectron angular distribution as a function of photon energy. The region of interest contains autoionizing valence states, vibrationally autoionizing Rydberg states converging to vibrationally excited levels of the N 2 + X 2Σ g +more » ground state, and electronically autoionizing states converging to the N 2 + A 2Π and B 2Σ u + states. The wavelength resolution is sufficient to resolve rotational structure in the autoionizing states, but the electron energy resolution is insufficient to resolve rotational structure in the photoion spectrum. Here, a simplified approach based on multichannel quantum defect theory is used to predict the photoelectron angular distribution parameters, β, and the results are in reasonably good agreement with experiment.« less

The effect of ultra-violet light curing on the molecular structure and fracture properties of an ultra low-k material

NASA Astrophysics Data System (ADS)

Smith, Ryan Scott

As the gate density increases in microelectronic devices, the interconnect delay or RC response also increases and has become the limiting delay to faster devices. In order to decrease the RC time delay, a new metallization scheme has been chosen by the semiconductor industry. Copper has replaced aluminum as the metal lines and new low-k dielectric materials are being developed to replace silicon dioxide. A promising low-k material is porous organosilicate glass or p-OSG. The p-OSG film is a hybrid material where the silicon dioxide backbone is terminated with methyl or hydrogen, reducing the dielectric constant and creating mechanically weak films that are prone to fracture. A few methods of improving the mechanical properties of p-OSG films have been attempted-- exposing the film to hydrogen plasma, electron beam curing, and ultra-violet light curing. Hydrogen plasma and electron-beam curing suffer from a lack of specificity and can cause charging damage to the gates. Therefore, ultra-violet light curing (UV curing) is preferable. The effect of UV curing on an ultra-low-k, k~2.5, p-OSG film is studied in this dissertation. Changes in the molecular structure were measured with Fourier Transform Infrared Spectroscopy and X-ray Photoelectron Spectroscopy. The evolution of the molecular structure with UV curing was correlated with material and fracture properties. The material properties were film shrinkage, densification, and an increase in dielectric constant. From the changes in molecular structure and material properties, a set of condensation reactions with UV light are predicted. The connectivity of the film increases with the condensation reactions and, therefore, the fracture toughness should also increase. The effect of UV curing on the critical and sub-critical fracture toughness was also studied. The critical fracture toughness was measured at four different mode-mixes-- zero, 15°, 32°, and 42°. It was found that the critical fracture toughness

Photoelectron Spectroscopy in Advanced Placement Chemistry

ERIC Educational Resources Information Center

Benigna, James

2014-01-01

Photoelectron spectroscopy (PES) is a new addition to the Advanced Placement (AP) Chemistry curriculum. This article explains the rationale for its inclusion, an overview of how the PES instrument records data, how the data can be analyzed, and how to include PES data in the course. Sample assessment items and analysis are included, as well as…

A photoelectron spectroscopic investigation of vinyl fluoride (C2H3F): the HeI, threshold and CIS photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Locht, R.; Leyh, B.; Dehareng, D.; Hottmann, K.; Baumgärtel, H.

2010-01-01

The threshold photoelectron spectrum (TPES) and the constant ion state (CIS) spectra of the individual ionic states of C2H3F have been recorded using synchrotron radiation. For comparison a well-resolved HeI photoelectron spectrum (HeI-PES) has also been measured and analysed in detail. The TPES has been measured between 9.5 eV and 35 eV photon energy. Numerous vibrational structures, reported for the first time, observed in the ground state and the six excited states of the cation are analysed. Quantum chemical calculations have been performed and provide strong support to the assignments. State-selected CIS spectra highlighted the major importance of autoionization for the production of almost all ionized states of C2H3F observed in this work.

A comparative study on NbOx films reactively sputtered from sintered and cold gas sprayed targets

NASA Astrophysics Data System (ADS)

Lorenz, Roland; O'Sullivan, Michael; Fian, Alexander; Sprenger, Dietmar; Lang, Bernhard; Mitterer, Christian

2018-04-01

The aim of this work is to evaluate novel cold gas sprayed Nb targets in a reactive sputter deposition process of thin films with respect to the widely used sintered Nb targets. With the exception of a higher target discharge voltage of ∼100 V for the cold gas sprayed targets and the thus higher film growth rate compared to sintered targets, NbOx films with comparable microstructure and properties were obtained for both target variants. The amorphous films with thicknesses between 2.9 and 4.9 μm present an optical shift from dark and non-transparent towards transparent properties, as the oxygen partial pressure increases. X-ray photoelectron spectroscopy confirms the occurrence of the Nb5+ oxidation state for the highest oxygen partial pressure, while Nb4+ is additionally present at lower oxygen partial pressure settings. With a maximal transparency of ∼80% and a refractive index of ∼2.5, the transparent films show characteristics similar to Nb2O5.

Photoelectron diffraction and holography: Some new directions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fadley, C.S.

1993-08-01

Photoelectron diffraction has by now become a versatile and powerful technique for studying surface structures, with special capabilities for resolving chemical and magnetic states of atoms and deriving direct structural information from both forward scattering along bond directions and back-scattering path length differences. Further fitting experiment to theory can lead to structural accuracies in the {plus_minus}0.03 ){Angstrom} range. Holographic inversions of such diffraction data also show considerable promise for deriving local three-dimensional structures around a given emitter with accuracies of {plus_minus}0.2--0.3 {Angstrom}. Resolving the photoelectron spin in some way and using circularly polarized radiation for excitation provide added dimensions formore » the study of magnetic systems and chiral experimental geometries. Synchrotron radiation with the highest brightness and energy resolution, as well as variable polarization, is crucial to the full exploitation of these techniques.« less

A novel ultra-low carbon grain oriented silicon steel produced by twin-roll strip casting

NASA Astrophysics Data System (ADS)

Wang, Yang; Zhang, Yuan-Xiang; Lu, Xiang; Fang, Feng; Xu, Yun-Bo; Cao, Guang-Ming; Li, Cheng-Gang; Misra, R. D. K.; Wang, Guo-Dong

2016-12-01

A novel ultra-low carbon grain oriented silicon steel was successfully produced by strip casting and two-stage cold rolling method. The microstructure, texture and precipitate evolution under different first cold rolling reduction were investigated. It was shown that the as-cast strip was mainly composed of equiaxed grains and characterized by very weak Goss texture ({110}<001>) and λ-fiber (<001>//ND). The coarse sulfides of size 100 nm were precipitated at grain boundaries during strip casting, while nitrides remained in solution in the as-cast strip and the fine AlN particles of size 20-50 nm, which were used as grain growth inhibitors, were formed in intermediate annealed sheet after first cold rolling. In addition, the suitable Goss nuclei for secondary recrystallization were also formed during intermediate annealing, which is totally different from the conventional process that the Goss nuclei originated in the subsurface layer of the hot rolled sheet. Furthermore, the number of AlN inhibitors and the intensity of desirable Goss texture increased with increasing first cold rolling reduction. After secondary recrystallization annealing, very large grains of size 10-40 mm were formed and the final magnetic induction, B8, was as high as 1.9 T.

Photoelectron spectra of carbonyls. Propellenes and propellanones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dougherty, D.; Bloomfield, J.J.; Newkome, G.R.

1976-09-23

The HeI photoelectron spectra (UPS) of a number of unsaturated (4.4.2)propellanes and (4.4.2)propellane-dione derivatives are presented. The interpretation of the UPS data is based on through-space and through-bond interaction models and on CNDO/s computations. An analysis of the photoelectron spectra of (4.4.2)propella-3,8-diene-11,12-dione (1), (4.4.2)propell-3-ene-11,12-dione (2), (4.4.2)propellane-11,12-dione (3), (4.4.2)propella-3,8-dien-11-one (4), and (4.4.2) propella-3,8-diene (5) involves the assignment of n/sub +/, n/sub -/, ..pi../sub +/, ..pi../sub -/, and sigma/sub square/ (i.e., cyclobutane sigma) ionization events. The analysis of the data for 5, (4.4.2)propella-3,8,11-triene (6), (4.4.2)propella-3,11-diene (7), and (4.4.2)propell-11-ene (8) leads to the conclusion that the photoelectron spectrum of 6 should be reassigned.more » The /sup 1/GAMMA/sub n..pi..*/ reverse arrow /sup 1/GAMMA/sub 1/ absorption spectra of 1,2, and 3 have been investigated as a function of temperature. The low energy of this transition in 1 is attributed to a high degree of CO/CO coplanarity, the high energy of this transition in 3 is attributed to CO/CO noncoplanarity, and the isomerism evident in 2 is attributed to multiple minima of the potential energy along the CO/CO dihedral angle coordinate of the ground state.« less

Comparative study on gamma irradiation and cold plasma pretreatment for a cellulosic substrate modification with phenolic compounds

NASA Astrophysics Data System (ADS)

Irimia, Anamaria; Ioanid, Ghiocel Emil; Zaharescu, Traian; Coroabă, Adina; Doroftei, Florica; Safrany, Agnes; Vasile, Cornelia

2017-01-01

The efficiency of the activation of the cellulose/chitin mix substrate by cold plasma or γ-radiation exposure in order to modify it with bioactive compounds was studied. The eugenol or vegetable oils such as grape seed oil and rosehip seed oil have been grafted onto activated substrate. The examination of modified cellulose/chitin mix substrate by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy confirms that the structural and morphological changes took place in both cases. The grafting degrees of the surface layer estimated from XPS data varied from 31.1% to 58.7% for air cold plasma activation and from 9.7% to 22.8% for γ-irradiation treatment. They depend both on bioactive compound used and procedure of substrate activation. Higher grafting degree are obtain by using vegetable oils than in the case of modification with eugenol and the air cold plasma activation seems to be much efficient than γ-irradiation. By grafting the polymeric substrate with bioactive compounds, antimicrobial and antioxidant properties have been conferred. Such materials can be considered promising for food packaging applications and medical textiles and also the applied procedures are environmental friendly ones.

Interatomic scattering in energy dependent photoelectron spectra of Ar clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patanen, M.; Benkoula, S.; Nicolas, C.

2015-09-28

Soft X-ray photoelectron spectra of Ar 2p levels of atomic argon and argon clusters are recorded over an extended range of photon energies. The Ar 2p intensity ratios between atomic argon and clusters’ surface and bulk components reveal oscillations similar to photoelectron extended X-ray absorption fine structure signal (PEXAFS). We demonstrate here that this technique allows us to analyze separately the PEXAFS signals from surface and bulk sites of free-standing, neutral clusters, revealing a bond contraction at the surface.

A formula for calculating theoretical photoelectron fluxes resulting from the He/+/ 304 A solar spectral line

NASA Technical Reports Server (NTRS)

Richards, P. G.; Torr, D. G.

1981-01-01

A simplified method for the evaluation of theoretical photoelectron fluxes in the upper atmosphere resulting from the solar radiation at 304 A is presented. The calculation is based on considerations of primary and cascade (secondary) photoelectron production in the two-stream model, where photoelectron transport is described by two electron streams, one moving up and one moving down, and of loss rates due to collisions with neutral gases and thermal electrons. The calculation is illustrated for the case of photoelectrons at an energy of 24.5 eV, and it is noted that the 24.5-eV photoelectron flux may be used to monitor variations in the solar 304 A flux. Theoretical calculations based on various ionization and excitation cross sections of Banks et al. (1974) are shown to be in generally good agreement with AE-E measurements taken between 200 and 235 km, however the use of more recent, larger cross sections leads to photoelectron values a factor of two smaller than observations but in agreement with previous calculations. It is concluded that a final resolution of the photoelectron problem may depend on a reevaluation of the inelastic electron collision cross sections.

Improving photoelectron counting and particle identification in scintillation detectors with Bayesian techniques

NASA Astrophysics Data System (ADS)

Akashi-Ronquest, M.; Amaudruz, P.-A.; Batygov, M.; Beltran, B.; Bodmer, M.; Boulay, M. G.; Broerman, B.; Buck, B.; Butcher, A.; Cai, B.; Caldwell, T.; Chen, M.; Chen, Y.; Cleveland, B.; Coakley, K.; Dering, K.; Duncan, F. A.; Formaggio, J. A.; Gagnon, R.; Gastler, D.; Giuliani, F.; Gold, M.; Golovko, V. V.; Gorel, P.; Graham, K.; Grace, E.; Guerrero, N.; Guiseppe, V.; Hallin, A. L.; Harvey, P.; Hearns, C.; Henning, R.; Hime, A.; Hofgartner, J.; Jaditz, S.; Jillings, C. J.; Kachulis, C.; Kearns, E.; Kelsey, J.; Klein, J. R.; Kuźniak, M.; LaTorre, A.; Lawson, I.; Li, O.; Lidgard, J. J.; Liimatainen, P.; Linden, S.; McFarlane, K.; McKinsey, D. N.; MacMullin, S.; Mastbaum, A.; Mathew, R.; McDonald, A. B.; Mei, D.-M.; Monroe, J.; Muir, A.; Nantais, C.; Nicolics, K.; Nikkel, J. A.; Noble, T.; O'Dwyer, E.; Olsen, K.; Orebi Gann, G. D.; Ouellet, C.; Palladino, K.; Pasuthip, P.; Perumpilly, G.; Pollmann, T.; Rau, P.; Retière, F.; Rielage, K.; Schnee, R.; Seibert, S.; Skensved, P.; Sonley, T.; Vázquez-Jáuregui, E.; Veloce, L.; Walding, J.; Wang, B.; Wang, J.; Ward, M.; Zhang, C.

2015-05-01

Many current and future dark matter and neutrino detectors are designed to measure scintillation light with a large array of photomultiplier tubes (PMTs). The energy resolution and particle identification capabilities of these detectors depend in part on the ability to accurately identify individual photoelectrons in PMT waveforms despite large variability in pulse amplitudes and pulse pileup. We describe a Bayesian technique that can identify the times of individual photoelectrons in a sampled PMT waveform without deconvolution, even when pileup is present. To demonstrate the technique, we apply it to the general problem of particle identification in single-phase liquid argon dark matter detectors. Using the output of the Bayesian photoelectron counting algorithm described in this paper, we construct several test statistics for rejection of backgrounds for dark matter searches in argon. Compared to simpler methods based on either observed charge or peak finding, the photoelectron counting technique improves both energy resolution and particle identification of low energy events in calibration data from the DEAP-1 detector and simulation of the larger MiniCLEAN dark matter detector.

Photo-electronic current transport in back-gated graphene transistor

NASA Astrophysics Data System (ADS)

Srivastava, Ashok; Chen, Xinlu; Pradhan, Aswini K.

2017-04-01

In this work, we have studied photo-electronic current transport in a back-gated graphene field-effect transistor. Under the light illumination, band bending at the metal/graphene interface develops a built-in potential which generates photonic current at varying back-gate biases. A typical MOSFET type back-gated transistor structure uses a monolayer graphene as the channel layer formed over the silicon dioxide/silicon substrate. It is shown that the photo-electronic current consists of current contributions from photovoltaic, photo-thermoelectric and photo-bolometric effects. A maximum external responsivity close to 0.0009A/W is achieved at 30μW laser power source and 633nm wavelength.

Effect of pH on Semiconducting Property of Passive Film Formed on Ultra-High-Strength Corrosion-Resistant Steel in Sulfuric Acid Solution

NASA Astrophysics Data System (ADS)

Sun, Min; Xiao, Kui; Dong, Chaofang; Li, Xiaogang; Zhong, Ping

2013-10-01

Because Cr9Ni5MoCo14 is a new ultra-high-strength corrosion-resistant steel, it is important to study its corrosion behavior in sulfuric acid solution, which is used to simulate the aggressive environment. The effect of pH on the electrochemical and semiconducting properties of passive films formed on ultra-high-strength corrosion-resistant steel in sulfuric acid solution was investigated by means of the potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and X-ray photoelectron spectroscopy (XPS). The results indicated that Cr9Ni5MoCo14 steel showed a passive state in acid solutions. The corrosion behavior of this Cr9Ni5MoCo14 alloy was influenced by the passive film formed on the surface, including thickness, stability, and partitioning of elements of the passive film. The passive current density decreases with increasing pH, and the corrosion resistance was enhanced by the increasing thickness and depletion of the defects within the passive film. Moreover, an enrichment of chromium (primarily the oxides of Cr) and depletion of iron in the passive film led to improved corrosion resistance. These results can provide a theoretical basis for use of this alloy and further development of ultra-high-strength corrosion-resistant steel in today's society.

Modelling Photoelectron Production in the Enceladus Plume and Comparison with Observations by CAPS-ELS

NASA Astrophysics Data System (ADS)

Taylor, S. A.; Coates, A. J.; Jones, G.; Wellbrock, A.; Waite, J. H., Jr.

2016-12-01

The Electron Spectrometer (ELS) of the Cassini Plasma Spectrometer (CAPS) measures electrons in the energy range 0.6-28,000 eV with an energy resolution of 16.7%. ELS has observed photoelectrons produced in the plume of Enceladus. These photoelectrons are found during Enceladus encounters in the energetic particle shadow where the spacecraft is shielded from penetrating radiation by the moon [Coates et al, 2013]. Observable is a population of photoelectrons at 20-30eV, which are seen at other bodies in the solar system and are usually associated with ionisation by the strong solar He II (30.4 nm) line. We have identified secondary peaks at 40-50eV detected by ELS which are also interpreted as a warmer population of photoelectrons created through the ionisation of neutrals in the Enceladus torus. We have constructed a model of photoelectron production in the plume and compared it with ELS Enceladus flyby data using automated fitting procedures. This has yielded estimates for electron temperature and density as well as a spacecraft potential estimate which is corrected for.

On the analysis of photo-electron spectra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, C.-Z., E-mail: gao@irsamc.ups-tlse.fr; CNRS, LPT; Dinh, P.M.

2015-09-15

We analyze Photo-Electron Spectra (PES) for a variety of excitation mechanisms from a simple mono-frequency laser pulse to involved combination of pulses as used, e.g., in attosecond experiments. In the case of simple pulses, the peaks in PES reflect the occupied single-particle levels in combination with the given laser frequency. This usual, simple rule may badly fail in the case of excitation pulses with mixed frequencies and if resonant modes of the system are significantly excited. We thus develop an extension of the usual rule to cover all possible excitation scenarios, including mixed frequencies in the attosecond regime. We find thatmore » the spectral distributions of dipole, monopole and quadrupole power for the given excitation taken together and properly shifted by the single-particle energies provide a pertinent picture of the PES in all situations. This leads to the derivation of a generalized relation allowing to understand photo-electron yields even in complex experimental setups.« less

X-Ray photoelectron diffraction and photoelectron holography as methods for investigating the local atomic structure of the surface of solids

NASA Astrophysics Data System (ADS)

Kuznetsov, M. V.; Ogorodnikov, I. I.; Vorokh, A. S.

2014-01-01

The state-of-the-art theory and experimental applications of X-ray photoelectron diffraction (XPD) and photoelectron holography (PH) are discussed. These methods are rapidly progressing and serve to examine the surface atomic structure of solids, including nanostructures formed on surfaces during adsorption of gases, epitaxial film growth, etc. The depth of analysis by these methods is several nanometres, which makes it possible to characterize the positions of atoms localized both on and beneath the surface. A remarkable feature of the XPD and PH methods is their sensitivity to the type of examined atoms and, in the case of high energy resolution, to the particular chemical form of the element under study. The data on experimental applications of XPD and PH to studies of various surface structures are analyzed and generalized. The bibliography includes 121 references.

Cold Stress

MedlinePlus

... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

X-ray photoelectron spectroscopy of select multi-layered transition metal carbides (MXenes)

DOE PAGES

Halim, Joseph; Cook, Kevin M.; Naguib, Michael; ...

2015-12-01

A detailed high resolution X-ray photoelectron spectroscopy (XPS) analysis is presented in this work for select MXenes—a recently discovered family of two-dimensional (2D) carbides and carbonitrides. Given their 2D nature, understanding their surface chemistry is paramount. Thus we identify and quantify the surface groups present before, and after, sputter-cleaning as well as freshly prepared vs. aged multi-layered cold pressed discs. The nominal compositions of the MXenes studied here are Ti 3C 2T x, Ti 2CT x, Ti 3CNTx, Nb 2CT x and Nb 4C 3T x, where T represents surface groups that this work attempts to quantify. In all themore » cases, the presence of three surface terminations, single bondO, single bondOH and single bondF, in addition to OH-terminations relatively strongly bonded to H 2O molecules, was confirmed. Moreover, from XPS peak fits, it was possible to establish the average sum of the negative charges of the terminations for the aforementioned MXenes. Based on this work, it is now possible to quantify the nature of the surface terminations. This information can, in turn, be used to better design and tailor these novel 2D materials for various applications.« less

Hypothermic general cold adaptation induced by local cold acclimation.

PubMed

Savourey, G; Barnavol, B; Caravel, J P; Feuerstein, C; Bittel, J H

1996-01-01

To study relationships between local cold adaptation of the lower limbs and general cold adaptation, eight subjects were submitted both to a cold foot test (CFT, 5 degrees C water immersion, 5 min) and to a whole-body standard cold air test (SCAT, 1 degree C, 2 h, nude at rest) before and after a local cold acclimation (LCA) of the lower limbs effected by repeated cold water immersions. The LCA induced a local cold adaptation confirmed by higher skin temperatures of the lower limbs during CFT and a hypothermic insulative general cold adaptation (decreased rectal temperature and mean skin temperature P < 0.05) without a change either in metabolic heat production or in lower limb skin temperatures during SCAT after LCA. It was concluded that local cold adaptation was related to the habituation process confirmed by decreased plasma concentrations of noradrenaline (NA) during LCA (P < 0.05). However, the hypothermic insulative general cold adaptation was unrelated either to local cold adaptation or to the habituation process, because an increased NA during SCAT after LCA (P < 0.05) was observed but was rather related to a "T3 polar syndrome" occurring during LCA.

Photoelectric dust levitation around airless bodies revised using realistic photoelectron velocity distributions

NASA Astrophysics Data System (ADS)

Senshu, H.; Kimura, H.; Yamamoto, T.; Wada, K.; Kobayashi, M.; Namiki, N.; Matsui, T.

2015-10-01

The velocity distribution function of photoelectrons from a surface exposed to solar UV radiation is fundamental to the electrostatic status of the surface. There is one and only one laboratory measurement of photoelectron emission from astronomically relevant material, but the energy distribution function was measured only in the emission angle from the normal to the surface of 0 to about π / 4. Therefore, the measured distribution is not directly usable to estimate the vertical structure of a photoelectric sheath above the surface. In this study, we develop a new analytical method to calculate an angle-resolved velocity distribution function of photoelectrons from the laboratory measurement data. We find that the photoelectric current and yield for lunar surface fines measured in a laboratory have been underestimated by a factor of two. We apply our new energy distribution function of photoelectrons to model the formation of photoelectric sheath above the surface of asteroid 433 Eros. Our model shows that a 0.1 μm-radius dust grain can librate above the surface of asteroid 433 Eros regardless of its launching velocity. In addition, a 0.5 μm grain can hover over the surface if the grain was launched at a velocity slower than 0.4 m/s, which is a more stringent condition for levitation than previous studies. However, a lack of high-energy data on the photoelectron energy distribution above 6 eV prevents us from firmly placing a constraint on the levitation condition.

Generation of single photons with highly tunable wave shape from a cold atomic ensemble

PubMed Central

Farrera, Pau; Heinze, Georg; Albrecht, Boris; Ho, Melvyn; Chávez, Matías; Teo, Colin; Sangouard, Nicolas; de Riedmatten, Hugues

2016-01-01

The generation of ultra-narrowband, pure and storable single photons with widely tunable wave shape is an enabling step toward hybrid quantum networks requiring interconnection of remote disparate quantum systems. It allows interaction of quantum light with several material systems, including photonic quantum memories, single trapped ions and opto-mechanical systems. Previous approaches have offered a limited tuning range of the photon duration of at most one order of magnitude. Here we report on a heralded single photon source with controllable emission time based on a cold atomic ensemble, which can generate photons with temporal durations varying over three orders of magnitude up to 10 μs without a significant change of the readout efficiency. We prove the nonclassicality of the emitted photons, show that they are emitted in a pure state, and demonstrate that ultra-long photons with nonstandard wave shape can be generated, which are ideally suited for several quantum information tasks. PMID:27886166

Holographic Reconstruction of Photoelectron Diffraction and Its Circular Dichroism for Local Structure Probing

NASA Astrophysics Data System (ADS)

Matsui, Fumihiko; Matsushita, Tomohiro; Daimon, Hiroshi

2018-06-01

The local atomic structure around a specific element atom can be recorded as a photoelectron diffraction pattern. Forward focusing peaks and diffraction rings around them indicate the directions and distances from the photoelectron emitting atom to the surrounding atoms. The state-of-the-art holography reconstruction algorithm enables us to image the local atomic arrangement around the excited atom in a real space. By using circularly polarized light as an excitation source, the angular momentum transfer from the light to the photoelectron induces parallax shifts in these diffraction patterns. As a result, stereographic images of atomic arrangements are obtained. These diffraction patterns can be used as atomic-site-resolved probes for local electronic structure investigation in combination with spectroscopy techniques. Direct three-dimensional atomic structure visualization and site-specific electronic property analysis methods are reviewed. Furthermore, circular dichroism was also found in valence photoelectron and Auger electron diffraction patterns. The investigation of these new phenomena provides hints for the development of new techniques for local structure probing.

Development of the Science Data System for the International Space Station Cold Atom Lab

NASA Technical Reports Server (NTRS)

van Harmelen, Chris; Soriano, Melissa A.

2015-01-01

Cold Atom Laboratory (CAL) is a facility that will enable scientists to study ultra-cold quantum gases in a microgravity environment on the International Space Station (ISS) beginning in 2016. The primary science data for each experiment consists of two images taken in quick succession. The first image is of the trapped cold atoms and the second image is of the background. The two images are subtracted to obtain optical density. These raw Level 0 atom and background images are processed into the Level 1 optical density data product, and then into the Level 2 data products: atom number, Magneto-Optical Trap (MOT) lifetime, magnetic chip-trap atom lifetime, and condensate fraction. These products can also be used as diagnostics of the instrument health. With experiments being conducted for 8 hours every day, the amount of data being generated poses many technical challenges, such as downlinking and managing the required data volume. A parallel processing design is described, implemented, and benchmarked. In addition to optimizing the data pipeline, accuracy and speed in producing the Level 1 and 2 data products is key. Algorithms for feature recognition are explored, facilitating image cropping and accurate atom number calculations.

Photoelectron imaging using an ellipsoidal display analyzer

NASA Astrophysics Data System (ADS)

Dütemeyer, T.; Quitmann, C.; Kitz, M.; Dörnemann, K.; Johansson, L. S. O.; Reihl, B.

2001-06-01

We have built an ellipsoidal display analyzer (EDA) for angle-resolved photoelectron spectroscopy and related techniques. The instrument is an improved version of a design by Eastman et al. [Nucl. Instrum. Methods 172, 327 (1980)] and measures the angle-resolved intensity distribution of photoelectrons at fixed energy I(θ,φ)|E=const.. Such two-dimensional cuts through the Brillouin zone are recorded using a position-sensitive detector. The large acceptance angle (Δθ=43° in the polar direction and Δφ=360° in the azimuthal direction) leads to a collection efficiency which exceeds that of conventional hemispherical analyzers by a factor of about 3000. Using ray-tracing calculations we analyze the electron optical properties of the various analyzer components and optimize their arrangement. This minimizes distortions and aberrations in the recorded images and greatly improves the performance compared to previous realizations of this analyzer. We present examples demonstrating the performance of the analyzer and its versatility. Using a commercial He-discharge lamp we are able to measure complete angular distribution patterns in less than 5 s. The energy and angular resolution are ΔEEDA=85 meV and Δθ=1.2°, respectively. Complete stacks of such cuts through the Brillouin zone at different kinetic energies E can be acquired automatically using custom software. The raw data are processed leading to a three-dimensional set (I(EB,k∥) of photoelectron intensity versus binding energy E and wave vector k∥. From this all relevant information, like the dispersion relations EB(k∥) along arbitrary directions of the Brillouin zone or Fermi-surface maps, can then be computed. An additional electron gun enables low-energy electron diffraction, Auger electron spectroscopy, and electron energy-loss spectroscopy. Switching between electrons and photons as the excitation source is possible without any movement of the sample or analyzer. Because of the high acquisition

Photoelectron spectroscopy of heavy atoms and molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, M.G.

1979-07-01

The importance of relativistic interactions in the photoionization of heavy atoms and molecules has been investigated by the technique of photoelectron spectroscopy. In particular, experiments are reported which illustrate the effects of the spin-orbit interaction in the neutral ground state, final ionic states and continuum states of the photoionization target.

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography.

PubMed

Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; Liu, Peng; Chen, Zhangjin; Yang, Weifeng; Hu, Shilin; Lin, C D; Chen, Jing

2016-06-22

Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. In addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. We showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules.

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography

PubMed Central

Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; Liu, Peng; Chen, Zhangjin; Yang, Weifeng; Hu, Shilin; Lin, C. D.; Chen, Jing

2016-01-01

Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. In addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. We showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules. PMID:27329071

Photoelectron interference fringes by super intense x-ray laser pulses

NASA Astrophysics Data System (ADS)

Toyota, Koudai; Tolstikhin, Oleg I.; Morishita, Toru; Watanabe, Shinichi

2009-09-01

The photoelectron spectra of H- produced by circularly polarized strong high-frequency laser pulses are theoretically studied. An oscillating substructure in the above-threshold ionization (ATI) peaks is observed, which extends the validity of the earlier findings in the 1D calculations [K. Toyota et al., Phys. Rev. A 76, 043418 (2007)] and 3D calculations for linear polarization [O. I. Tolstikhin, Phys. Rev. A 77, 032712 (2008)]. Its origin is due to an interference between a pair of photoelectron wave packets created in the rising and falling part of the pulse, which appears clearly in the stabilization regime.

Dark field photoelectron emission microscopy of micron scale few layer graphene

NASA Astrophysics Data System (ADS)

Barrett, N.; Conrad, E.; Winkler, K.; Krömker, B.

2012-08-01

We demonstrate dark field imaging in photoelectron emission microscopy (PEEM) of heterogeneous few layer graphene (FLG) furnace grown on SiC(000-1). Energy-filtered, threshold PEEM is used to locate distinct zones of FLG graphene. In each region, selected by a field aperture, the k-space information is imaged using appropriate transfer optics. By selecting the photoelectron intensity at a given wave vector and using the inverse transfer optics, dark field PEEM gives a spatial distribution of the angular photoelectron emission. In the results presented here, the wave vector coordinates of the Dirac cones characteristic of commensurate rotations of FLG on SiC(000-1) are selected providing a map of the commensurate rotations across the surface. This special type of contrast is therefore a method to map the spatial distribution of the local band structure and offers a new laboratory tool for the characterisation of technically relevant, microscopically structured matter.

Rosetta photoelectron emission and solar ultraviolet flux at comet 67P

NASA Astrophysics Data System (ADS)

Johansson, Fredrik L.; Odelstad, E.; Paulsson, J. J. P.; Harang, S. S.; Eriksson, A. I.; Mannel, T.; Vigren, E.; Edberg, N. J. T.; Miloch, W. J.; Simon Wedlund, C.; Thiemann, E.; Eparvier, F.; Andersson, L.

2017-07-01

The Langmuir Probe instrument on Rosetta monitored the photoelectron emission current of the probes during the Rosetta mission at comet 67P/Churyumov-Gerasimenko, in essence acting as a photodiode monitoring the solar ultraviolet radiation at wavelengths below 250 nm. We have used three methods of extracting the photoelectron saturation current from the Langmuir probe measurements. The resulting data set can be used as an index of the solar far and extreme ultraviolet at the Rosetta spacecraft position, including flares, in wavelengths which are important for photoionization of the cometary neutral gas. Comparing the photoemission current to data measurements by MAVEN/EUVM and TIMED/SEE, we find good correlation when 67P was at large heliocentric distances early and late in the mission, but up to 50 per cent decrease of the expected photoelectron current at perihelion. We discuss possible reasons for the photoemission decrease, including scattering and absorption by nanograins created by disintegration of cometary dust far away from the nucleus.

Designable ultra-smooth ultra-thin solid-electrolyte interphases of three alkali metal anodes.

PubMed

Gu, Yu; Wang, Wei-Wei; Li, Yi-Juan; Wu, Qi-Hui; Tang, Shuai; Yan, Jia-Wei; Zheng, Ming-Sen; Wu, De-Yin; Fan, Chun-Hai; Hu, Wei-Qiang; Chen, Zhao-Bin; Fang, Yuan; Zhang, Qing-Hong; Dong, Quan-Feng; Mao, Bing-Wei

2018-04-09

Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical polishing, which removes microscopic defects and creates ultra-smooth ultra-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the ultra-smooth ultra-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm -2 with 100% depth of discharge. Our work illustrates that an ultra-smooth ultra-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.

Some Chinese folk prescriptions for wind-cold type common cold.

PubMed

Hai-Long, Zhai; Shimin, Chen; Yalan, Lu

2015-07-01

Although self-limiting, the common cold (gǎn mào) is highly prevalent. There are no effective antivirals to cure the common cold and few effective measures to prevent it, However, for thousands years, Chinese people have treated the common cold with natural herbs, According to the traditional Chinese medicine (TCM) theory ( zhōng yī lǐ lùn), the common cold is considered as an exterior syndrome, which can be further divided into the wind-cold type ( fēng hán xíng), the wind-heat type ( fēng rè xíng), and the summer heat dampness type ( shǔ rè xíng). Since the most common type of common cold caught in winter and spring is the wind-cold type, the article introduced some Chinese folk prescriptions for the wind-cold type common cold with normal and weak physique, respectively. For thousands of years, Chinese folk prescriptions for the common cold, as complementary and alternative medicine (CAM; bǔ chōng yǔ tì dài yī xué), have been proven to be effective, convenient, cheap, and most importantly, safe. The Chinese folk prescriptions ( zhōng guó mín jiān chǔ fāng) for the wind-cold type common cold are quite suitable for general practitioners or patients with the wind-cold type common cold, to treat the disease. Of course, their pharmacological features and mechanisms of action need to be further studied.

Interfacial Chemistry-Induced Modulation of Schottky Barrier Heights: In Situ Measurements of the Pt-Amorphous Indium Gallium Zinc Oxide Interface Using X-ray Photoelectron Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flynn, Brendan T.; Oleksak, Richard P.; Thevuthasan, Suntharampillai

A method to modulate the Schottky barrier heights for platinum and amorphous indium gallium zinc oxide (a-IGZO) interfaces is demonstrated through thermal processing and background ambient pressure control. The interfacial chemistries that modulate barrier heights for the Pt/a-IGZO system were investigated using in-situ X-ray photoelectron spectroscopy. A significant reduction of indium, from In3+ to In0, occurs during deposition of Pt on to the a-IGZO surface in ultra-high vacuum. Post-annealing and controlling the background ambient O2 pressure allows tuning the degree of indium reduction and the corresponding Schottky barrier height between 0.17 to 0.77 eV. Understanding the detailed interfacial chemistries atmore » Pt/a-IGZO interfaces may allow for improved electronic device performance, including Schottky diodes, memristors, and metalsemiconductor field-effect transistors.« less

Interfacial Chemistry-Induced Modulation of Schottky Barrier Heights: In Situ Measurements of the Pt–Amorphous Indium Gallium Zinc Oxide Interface Using X-ray Photoelectron Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flynn, Brendan T.; Oleksak, Richard P.; Thevuthasan, Suntharampillai

A method to modulate the Schottky barrier heights for platinum and amorphous indium gallium zinc oxide (a-IGZO) interfaces is demonstrated through thermal processing and background ambient pressure control. The interfacial chemistries that modulate barrier heights for the Pt/a-IGZO system were investigated using in-situ X-ray photoelectron spectroscopy. A significant reduction of indium, from In 3+ to In 0, occurs during deposition of Pt on to the a-IGZO surface in ultra-high vacuum. Post-annealing and controlling the background ambient O 2 pressure allows tuning the degree of indium reduction and the corresponding Schottky barrier height between 0.17 to 0.77 eV. Understanding the detailedmore » interfacial chemistries at Pt/a-IGZO interfaces may allow for improved electronic device performance, including Schottky diodes, memristors, and metalsemiconductor field-effect transistors.« less

Graphene Membranes for Atmospheric Pressure Photoelectron Spectroscopy.

PubMed

Weatherup, Robert S; Eren, Baran; Hao, Yibo; Bluhm, Hendrik; Salmeron, Miquel B

2016-05-05

Atmospheric pressure X-ray photoelectron spectroscopy (XPS) is demonstrated using single-layer graphene membranes as photoelectron-transparent barriers that sustain pressure differences in excess of 6 orders of magnitude. The graphene serves as a support for catalyst nanoparticles under atmospheric pressure reaction conditions (up to 1.5 bar), where XPS allows the oxidation state of Cu nanoparticles and gas phase species to be simultaneously probed. We thereby observe that the Cu(2+) oxidation state is stable in O2 (1 bar) but is spontaneously reduced under vacuum. We further demonstrate the detection of various gas-phase species (Ar, CO, CO2, N2, O2) in the pressure range 10-1500 mbar including species with low photoionization cross sections (He, H2). Pressure-dependent changes in the apparent binding energies of gas-phase species are observed, attributable to changes in work function of the metal-coated grids supporting the graphene. We expect atmospheric pressure XPS based on this graphene membrane approach to be a valuable tool for studying nanoparticle catalysis.

Effects of anisotropic electron-ion interactions in atomic photoelectron angular distributions

NASA Technical Reports Server (NTRS)

Dill, D.; Starace, A. F.; Manson, S. T.

1975-01-01

A summary of the angular momentum transfer formulation of the differential photoionization cross section is presented and photoionization amplitudes in LS coupling are considered. The application of the theoretical concepts and relations developed is illustrated with the aid of an example involving the calculation of the angular distribution of photoelectrons ionized from atomic sulfur according to a certain reaction. The investigation shows that anisotropic electron-ion interactions in atomic sulfur lead to measurable differences between photoelectron angular distribution asymmetry parameters corresponding to alternative ionic term levels.

UHPLC/Q-TOFMS-based metabolomics for the characterization of cold and hot properties of Chinese materia medica.

PubMed

Wang, Yang; Zhou, Shujun; Wang, Meng; Liu, Shuying; Hu, Yuanjia; He, Chengwei; Li, Peng; Wan, Jian-Bo

2016-02-17

The cold/hot property of Chinese materia medica (CMM) and the application of its corresponding knowledge in the diagnosis, differentiation and treatment of diseases have been considered to be the extremely important part of traditional Chinese medicine (TCM). As highly abstracted TCM theory, the cold/hot property of CMMs is still not fully understood and remains to be elucidated by systems biology approach. The cold and hot properties of CMM are mainly defined by the response of the body to a given CMM. Metabolomics is a promising systems biology method to profile entire endogenous metabolites and monitor their fluctuations related to an exogenous stimulus. Thus, a metabolomics approach was applied to characterize the cold and hot properties of CMMs. Mice were intragastrically administered three selected cold property CMMs (i.e., Rheum palmatum L., radix et rhizoma; Coptis chinensis Franch, rhizome and Scutellaria baicalensis Georgi, radix) and three hot property CMMs (i.e., Cinnamomum cassia (L.) J. Presl, cortex; Zingiber officinale Roscoe, rhizoma and Evodia rutaecarpa (Juss.) Benth., fructus) once daily for one week. The comprehensive metabolome changes in the plasma of mice after treatment with cold or hot property CMMs were characterized by ultra-high performance liquid chromatography/time of flight mass spectrometry (UHPLC/Q-TOF-MS), and the potential biomarkers related to cold and hot properties of CMM were explored. Metabolites perturbation in plasma occurs after treatment with cold CMMs and hot CMMs in mice, and 15 and 16 differential biomarkers were identified to be associated with the cold and hot properties of CMMs, respectively. Among them, LPC (18:0), LPC (18:1), LPC (20:4) and LPC (20:5) showed decreased trends in the cold property CMM treated groups, but increased in the hot property CMM treated groups. There is a strong connection between the cold/hot property of CMMs and lysophosphatidylcholines metabolism. This study offers new insight

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography

DOE PAGES

Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; ...

2016-06-22

Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. Inmore » addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. Here, we showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules.« less

Noise thermometry at ultra-low temperatures.

PubMed

Rothfuss, D; Reiser, A; Fleischmann, A; Enss, C

2016-03-28

The options for primary thermometry at ultra-low temperatures are rather limited. In practice, most laboratories are using (195)Pt NMR thermometers in the microkelvin range. In recent years, current sensing direct current superconducting quantum interference devices (DC-SQUIDs) have enabled the use of noise thermometry in this temperature range. Such devices have also demonstrated the potential for primary thermometry. One major advantage of noise thermometry is the fact that no driving current is needed to operate the device and thus the heat dissipation within the thermometer can be reduced to a minimum. Ultimately, the intrinsic power dissipation is given by the negligible back action of the readout SQUID. For thermometry in low-temperature experiments, current noise thermometers and magnetic flux fluctuation thermometers have proved to be most suitable. To make use of such thermometers at ultra-low temperatures, we have developed a cross-correlation technique that reduces the amplifier noise contribution to a negligible value. For this, the magnetic flux fluctuations caused by the Brownian motion of the electrons in our noise source are measured inductively by two DC-SQUID magnetometers simultaneously and the signals from these two channels are cross-correlated. Experimentally, we have characterized a thermometer made of a cold-worked high-purity copper cylinder with a diameter of 5 mm and a length of 20 mm for temperatures between 42 μK and 0.8 K. For a given temperature, a measuring time below 1 min is sufficient to reach a precision of better than 1%. The extremely low power dissipation in the thermometer allows continuous operation without heating effects. © 2016 The Author(s).

Ar 3p photoelectron sideband spectra in two-color XUV + NIR laser fields

NASA Astrophysics Data System (ADS)

Minemoto, Shinichirou; Shimada, Hiroyuki; Komatsu, Kazma; Komatsubara, Wataru; Majima, Takuya; Mizuno, Tomoya; Owada, Shigeki; Sakai, Hirofumi; Togashi, Tadashi; Yoshida, Shintaro; Yabashi, Makina; Yagishita, Akira

2018-04-01

We performed photoelectron spectroscopy using femtosecond XUV pulses from a free-electron laser and femtosecond near-infrared pulses from a synchronized laser, and succeeded in measuring Ar 3p photoelectron sideband spectra due to the two-color above-threshold ionization. In our calculations of the first-order time-dependent perturbation theoretical model based on the strong field approximation, the photoelectron sideband spectra and their angular distributions are well reproduced by considering the timing jitter between the XUV and the NIR pulses, showing that the timing jitter in our experiments was distributed over the width of {1.0}+0.4-0.2 ps. The present approach can be used as a method to evaluate the timing jitter inevitable in FEL experiments.

2007 TY430: A COLD CLASSICAL KUIPER BELT TYPE BINARY IN THE PLUTINO POPULATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheppard, Scott S.; Ragozzine, Darin; Trujillo, Chadwick, E-mail: sheppard@dtm.ciw.edu

2012-03-15

Kuiper Belt object 2007 TY430 is the first wide, equal-sized, binary known in the 3:2 mean motion resonance with Neptune. The two components have a maximum separation of about 1 arcsec and are on average less than 0.1 mag different in apparent magnitude with identical ultra-red colors (g - i = 1.49 {+-} 0.01 mag). Using nearly monthly observations of 2007 TY430 from 2007 to 2011, the orbit of the mutual components was found to have a period of 961.2 {+-} 4.6 days with a semi-major axis of 21000 {+-} 160 km and eccentricity of 0.1529 {+-} 0.0028. The inclinationmore » with respect to the ecliptic is 15.68 {+-} 0.22 deg and extensive observations have allowed the mirror orbit to be eliminated as a possibility. The total mass for the binary system was found to be 7.90 {+-} 0.21 Multiplication-Sign 10{sup 17} kg. Equal-sized, wide binaries and ultra-red colors are common in the low-inclination 'cold' classical part of the Kuiper Belt and likely formed through some sort of three-body interactions within a much denser Kuiper Belt. To date 2007 TY430 is the only ultra-red, equal-sized binary known outside of the classical Kuiper Belt population. Numerical simulations suggest 2007 TY430 is moderately unstable in the outer part of the 3:2 resonance and thus 2007 TY430 is likely an escaped 'cold' classical object that later got trapped in the 3:2 resonance. Similar to the known equal-sized, wide binaries in the cold classical population, the binary 2007 TY430 requires a high albedo and very low density structure to obtain the total mass found for the pair. For a realistic minimum density of 0.5 g cm{sup -3} the albedo of 2007 TY430 would be greater than 0.17. For reasonable densities, the radii of either component should be less than 60 km, and thus the relatively low eccentricity of the binary is interesting since no tides should be operating on the bodies at their large distances from each other. The low prograde inclination of the binary also makes it unlikely that the

The Production of Cold Gas Within Galaxy Outflows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scannapieco, Evan

2017-03-01

I present a suite of three-dimensional simulations of the evolution of initially hot material ejected by starburst-driven galaxy outflows. The simulations are conducted in a comoving frame that moves with the material, tracking atomic/ionic cooling, Compton cooling, and dust cooling and destruction. Compton cooling is the most efficient of these processes, while the main role of atomic/ionic cooling is to enhance density inhomogeneities. Dust, on the other hand, has little effect on the outflow evolution, and is rapidly destroyed in all the simulations except for the case with the smallest mass flux. I use the results to construct a simplemore » steady-state model of the observed UV/optical emission from each outflow. The velocity profiles in this case are dominated by geometric effects, and the overall luminosities are extremely strong functions of the properties of the host system, as observed in ultra-luminous infrared galaxies (ULIRGs). Furthermore the luminosities and maximum velocities in several models are consistent with emission-line observations of ULIRGs, although the velocities are significantly greater than observed in absorption-line studies. It may be that absorption line observations of galaxy outflows probe entrained cold material at small radii, while emission-line observations probe cold material condensing from the initially hot medium at larger distances.« less

Compliance of Ultra-Orthodox and secular pedestrians with traffic lights in Ultra-Orthodox and secular locations.

PubMed

Rosenbloom, Tova; Shahar, Amit; Perlman, Amotz

2008-11-01

Following a previous study that revealed the disobedience of Ultra-Orthodox citizens, as compared to secular citizens, of traffic lights at crosswalks, the present study examined the road habits of 995 Ultra-Orthodox and secular pedestrians in neighboring Ultra-Orthodox and secular cities. Using an observation grid designed specially for this study, the pedestrians were observed at two crosswalks--one in an Ultra-Orthodox city and one in a secular city--as far as similar traffic parameters, using a logistic regression. The tendency to cross on a red light was assessed as a function of estimated age, gender, religiosity, location (religious/secular), the duration of the red light, the number of vehicles crossing and the number of pedestrians waiting at the curb. Ultra-Orthodox pedestrians committed more violations than secular pedestrians did, and there were more road violations in the Ultra-Orthodox location than there were in the secular location. Fewer traffic violations were committed by "local" pedestrians (Ultra-Orthodox pedestrians in the Ultra-Orthodox location and secular pedestrians in the secular location) than by "foreigners" (Ultra-Orthodox pedestrians in the secular location and secular pedestrians in the Ultra-Orthodox location). The odds of crossing on a red light decreased as a function of both the number of people waiting at the curb and the number of vehicles. Consistent with previous research, males crossed on red much more than females did, regardless of religiosity and location. Our discussion focuses on theoretical and practical explanations of the findings.

Effect of collisions on photoelectron sheath in a gas

NASA Astrophysics Data System (ADS)

Sodha, Mahendra Singh; Mishra, S. K.

2016-02-01

This paper presents a study of the effect of the collision of electrons with atoms/molecules on the structure of a photoelectron sheath. Considering the half Fermi-Dirac distribution of photo-emitted electrons, an expression for the electron density in the sheath has been derived in terms of the electric potential and the structure of the sheath has been investigated by incorporating Poisson's equation in the analysis. The method of successive approximations has been used to solve Poisson's equation with the solution for the electric potential in the case of vacuum, obtained earlier [Sodha and Mishra, Phys. Plasmas 21, 093704 (2014)], being used as the zeroth order solution for the present analysis. The inclusion of collisions influences the photoelectron sheath structure significantly; a reduction in the sheath width with increasing collisions is obtained.

Instrumentation for the Atmospheric Explorer photoelectron spectrometer

NASA Technical Reports Server (NTRS)

Peletier, D. P.

1973-01-01

The photoelectron spectrometer (PES) is part of the complements of scientific instruments aboard three NASA Atmosphere Explorer (AE) satellites. The PES measures the energy spectrum, angular distribution, and intensity of electrons in the earth's thermosphere. Measurements of energies between 2 and 500 eV are made at altitudes as low as 130 km. The design, characteristics, and performance of the instrument are described.

Model independent approach to the single photoelectron calibration of photomultiplier tubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saldanha, R.; Grandi, L.; Guardincerri, Y.

2017-08-01

The accurate calibration of photomultiplier tubes is critical in a wide variety of applications in which it is necessary to know the absolute number of detected photons or precisely determine the resolution of the signal. Conventional calibration methods rely on fitting the photomultiplier response to a low intensity light source with analytical approximations to the single photoelectron distribution, often leading to biased estimates due to the inability to accurately model the full distribution, especially at low charge values. In this paper we present a simple statistical method to extract the relevant single photoelectron calibration parameters without making any assumptions aboutmore » the underlying single photoelectron distribution. We illustrate the use of this method through the calibration of a Hamamatsu R11410 photomultiplier tube and study the accuracy and precision of the method using Monte Carlo simulations. The method is found to have significantly reduced bias compared to conventional methods and works under a wide range of light intensities, making it suitable for simultaneously calibrating large arrays of photomultiplier tubes.« less

X-Ray photoelectron Spectroscopy Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelhard, Mark H.; Droubay, Timothy C.; Du, Yingge

2017-01-03

With capability for obtaining quantitative elemental composition, chemical and electronic state, and overlayer thickness information from the top ~10 nm of a sample surface, X-ray Photoelectron Spectroscopy (XPS) or Electron Spectroscopy for Chemical Analysis (ESCA) is a versatile and widely used technique for analyzing surfaces. The technique is applied to a host of materials, from insulators to conductors in virtually every scientific field and sub-discipline. More recently, XPS has been extended under in-situ and operando conditions. Following a brief introduction to XPS principles and instrument components, this article exemplifies widely ranging XPS applications in material and life sciences.

Age-related changes in ultra-triathlon performances

PubMed Central

2012-01-01

Background The age-related decline in performance has been investigated in swimmers, runners and triathletes. No study has investigated the age-related performance decline in ultra-triathletes. The purpose of this study was to analyse the age-related declines in swimming, cycling, running and overall race time for both Triple Iron ultra-triathlon (11.4-km swimming, 540-km cycling and 126.6-km running) and Deca Iron ultra-triathlon (38-km swimming, 1,800-km cycling and 420-km running). Methods The age and performances of 423 male Triple Iron ultra-triathletes and 119 male Deca Iron ultra-triathletes were analysed from 1992 to 2010 using regression analyses and ANOVA. Results The mean age of the finishers was significantly higher for Deca Iron ultra-triathletes (41.3 ± 3.1 years) compared to a Triple Iron ultra-triathletes (38.5 ± 3.3 years) (P < 0.05). For both ultra-distances, the fastest overall race times were achieved between the ages of 25 and 44 years. Deca Iron ultra-triathletes achieved the same level of performance in swimming and cycling between 25 and 54 years of age. Conclusions The magnitudes of age-related declines in performance in the three disciplines of ultra-triathlon differ slightly between Triple and Deca Iron ultra-triathlon. Although the ages of Triple Iron ultra-triathletes were on average younger compared to Deca Iron ultra-triathletes, the fastest race times were achieved between 25 and 44 years for both distances. Further studies should investigate the motivation and training of ultra-triathletes to gain better insights in ultra-triathlon performance. PMID:23849327

Cold plate

DOEpatents

Marroquin, Christopher M.; O'Connell, Kevin M.; Schultz, Mark D.; Tian, Shurong

2018-02-13

A cold plate, an electronic assembly including a cold plate, and a method for forming a cold plate are provided. The cold plate includes an interface plate and an opposing plate that form a plenum. The cold plate includes a plurality of active areas arranged for alignment over respective heat generating portions of an electronic assembly, and non-active areas between the active areas. A cooling fluid flows through the plenum. The plenum, at the non-active areas, has a reduced width and/or reduced height relative to the plenum at the active areas. The reduced width and/or height of the plenum, and exterior dimensions of cold plate, at the non-active areas allow the non-active areas to flex to accommodate surface variations of the electronics assembly. The reduced width and/or height non-active areas can be specifically shaped to fit between physical features of the electronics assembly.

75 FR 63810 - Grant of Authority for Subzone Status; SICK, Inc. (Photo-Electronic Industrial Sensors...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-18

... Status; SICK, Inc. (Photo- Electronic Industrial Sensors); Bloomington, MN Pursuant to its authority... to establish a special- purpose subzone at the photo-electronic industrial sensor manufacturing and... manufacturing and distribution of photo-electronic industrial sensors at the SICK, Inc., facility located in...

Imprints of the Molecular Electronic Structure in the Photoelectron Spectra of Strong-Field Ionized Asymmetric Triatomic Model Molecules

NASA Astrophysics Data System (ADS)

Paul, Matthias; Yue, Lun; Gräfe, Stefanie

2018-06-01

We examine the circular dichroism in the angular distribution of photoelectrons of triatomic model systems ionized by strong-field ionization. Following our recent work on this effect [Paul, Yue, and Gräfe, J. Mod. Opt. 64, 1104 (2017), 10.1080/09500340.2017.1299883], we demonstrate how the symmetry and electronic structure of the system is imprinted into the photoelectron momentum distribution. We use classical trajectories to reveal the origin of the threefolded pattern in the photoelectron momentum distribution, and show how an asymmetric nuclear configuration of the triatomic system effects the photoelectron spectra.

What predicts performance in ultra-triathlon races? – a comparison between Ironman distance triathlon and ultra-triathlon

PubMed Central

Knechtle, Beat; Zingg, Matthias Alexander; Rosemann, Thomas; Stiefel, Michael; Rüst, Christoph Alexander

2015-01-01

Objective This narrative review summarizes recent intentions to find potential predictor variables for ultra-triathlon race performance (ie, triathlon races longer than the Ironman distance covering 3.8 km swimming, 180 km cycling, and 42.195 km running). Results from studies on ultra-triathletes were compared to results on studies on Ironman triathletes. Methods A literature search was performed in PubMed using the terms “ultra”, “triathlon”, and “performance” for the aspects of “ultra-triathlon”, and “Ironman”, “triathlon”, and “performance” for the aspects of “Ironman triathlon”. All resulting papers were searched for related citations. Results for ultra-triathlons were compared to results for Ironman-distance triathlons to find potential differences. Results Athletes competing in Ironman and ultra-triathlon differed in anthropometric and training characteristics, where both Ironmen and ultra-triathletes profited from low body fat, but ultra-triathletes relied more on training volume, whereas speed during training was related to Ironman race time. The most important predictive variables for a fast race time in an ultra-triathlon from Double Iron (ie, 7.6 km swimming, 360 km cycling, and 84.4 km running) and longer were male sex, low body fat, age of 35–40 years, extensive previous experience, a fast time in cycling and running but not in swimming, and origins in Central Europe. Conclusion Any athlete intending to compete in an ultra-triathlon should be aware that low body fat and high training volumes are highly predictive for overall race time. Little is known about the physiological characteristics of these athletes and about female ultra-triathletes. Future studies need to investigate anthropometric and training characteristics of female ultra-triathletes and what motivates women to compete in these races. Future studies need to correlate physiological characteristics such as maximum oxygen uptake (VO2max) with ultra

Photoelectron energy-loss study of the Bi2CaSr2Cu2O8 superconductor

NASA Astrophysics Data System (ADS)

Shen, Z.-X.; Lindberg, P. A. P.; Dessau, D. S.; Lindau, I.; Spicer, W. E.; Mitzi, D. B.; Bozovic, I.; Kapitulnik, A.

1989-03-01

Using energy-loss spectroscopy of photoelectrons from a single crystal of Bi2CaSr2Cu2O8, we show that the electronic structure of the near-surface region is the same as that of the bulk. Utilizing the fact that photoelectrons of different elements are excited at different locations in the unit cell, we identify the energy-loss features as due to valence plasmon excitations, and one-electron excitations by comparing the photoelectron energy-loss spectra of the different elements.

[Cold-induced urticaria].

PubMed

Delorme, N; Drouet, M; Thibaudeau, A; Verret, J L

2002-09-01

Cold urticaria is characterized by the development of urticaria, usually superficial and/or angioedematous reaction after cold contact. It was found predominantly in young women. The diagnosis is based on the history and ice cube test. Patients with a negative ice cube test may have represented systemic cold urticaria (atypical acquired cold urticaria) induced by general body cooling. The pathogenesis is poorly understood. Cold urticaria can be classified into acquired and familial disorders, with an autosomal dominant inheritance. Idiopathic cold urticaria is most common type but the research of a cryopathy is necessary. Therapy is often difficult. It is essential that the patient be warned of the dangers of swimming in cold water because systemic hypotension can occur. H1 antihistamines can be used for treatment of cold urticaria but the clinical responses are highly variable. The combination with an H2 antagonists is more effective. Doxepin may be useful in the treatment. Leukotriene receptor antagonists may be a novel, promising drug entity. In patients who do not respond to previous treatments, induction of cold tolerance may be tried.

Cold Rydberg atoms in circular states

NASA Astrophysics Data System (ADS)

Anderson, David; Schwarzkopf, Andrew; Raithel, Georg

2012-06-01

Circular-state Rydberg atoms are interesting in that they exhibit a unique combination of extraordinary properties; long lifetimes (˜n^5), large magnetic moments (l=|m|=n-1) and no first order Stark shift. Circular states have found applications in cavity quantum electrodynamics and precision measurements [1,2], among other studies. In this work we present the production of circular states in an atom trapping apparatus using an adiabatic state-switching method (the crossed-field method [3]). To date, we have observed lifetimes of adiabatically prepared states of several milliseconds. Their relatively large ionization electric fields have been verified by time-of-flight signatures of ion trajectories. We intend to explore the magnetic trapping of circular state Rydberg atoms, as well as their production and interaction properties in ultra-cold and degenerate samples.[4pt] [1] P. Bertet et al., Phys. Rev. Lett., 88, 14 (2002)[0pt] [2] M. Brune et al., Phys. Rev. Lett., 72, 21 (1994)[0pt] [3] D. Delande and J.C. Gay, Europhys. Lett., 5, 303-308 (1988).

Effect of Nb on Delayed Fracture Resistance of Ultra-High Strength Martensitic Steels

NASA Astrophysics Data System (ADS)

Song, Rongjie; Fonstein, Nina; Pottore, Narayan; Jun, Hyun Jo; Bhattacharya, Debanshu; Jansto, Steve

Ultra-high strength steels are materials of considerable interest for automotive and structural applications and are increasingly being used in those areas. Higher strength, however, makes steels more prone to hydrogen embrittlement (HE). The effects of Nb and other alloying elements on the hydrogen-induced delayed fracture resistance of cold rolled martensitic steels with ultra-high strength 2000 MPa were studied using an acid immersion test, thermal desorption analysis (TDA) and measuring of permeation. The microstructure was characterized by high resolution field emission Scanning Electron Microscopy (SEM) with Electron Backscattered Diffraction (EBSD) and Transmission Electron Microscopy (TEM). It was shown that the combined addition of Nb significantly improved the delayed fracture resistance of investigated steel. The addition of Nb to alloyed martensitic steels resulted in very apparent grain refinement of the prior austenite grain size. The Nb microalloyed steel contained a lower diffusible hydrogen content during thermal desorption analysis as compared to the base steel and had a higher trapped hydrogen amount after charging. The reason that Nb improved the delayed fracture resistance of steels can be attributed mostly to both hydrogen trapping and grain refinement.

Analysis of ultra-triathlon performances

PubMed Central

Lepers, Romuald; Knechtle, Beat; Knechtle, Patrizia; Rosemann, Thomas

2011-01-01

Despite increased interest in ultra-endurance events, little research has examined ultra-triathlon performance. The aims of this study were: (i) to compare swimming, cycling, running, and overall performances in three ultra-distance triathlons, double Ironman distance triathlon (2IMT) (7.6 km swimming, 360 km cycling, and 84.4 km running), triple Ironman distance triathlon (3IMT) (11.4 km, 540 km, and 126.6 km), and deca Ironman distance triathlon (10IMT) (38 km, 1800 km, and 420 km) and (ii) to examine the relationships between the 2IMT, 3IMT, and 10IMT performances to create predicted equations of the 10IMT performances. Race results from 1985 through 2009 were examined to identify triathletes who performed the three considered ultra-distances. In total, 73 triathletes (68 men and 5 women) were identified. The contribution of swimming to overall ultra-triathlon performance was lower than for cycling and running. Running performance was more important to overall performance for 2IMT and 3IMT compared with 10IMT The 2IMT and 3IMT performances were significantly correlated with 10IMT performances for swimming and cycling, but not for running. 10IMT total time performance might be predicted by the following equation: 10IMT race time (minutes) = 5885 + 3.69 × 3IMT race time (minutes). This analysis of human performance during ultra-distance triathlons represents a unique data set in the field of ultra-endurance events. Additional studies are required to determine the physiological and psychological factors associated with ultra-triathlon performance. PMID:24198579

Novel applications of X-ray photoelectron spectroscopy on unsupported nanoparticles

NASA Astrophysics Data System (ADS)

Kostko, Oleg; Xu, Bo; Jacobs, Michael I.; Ahmed, Musahid

X-ray photoelectron spectroscopy (XPS) is a powerful technique for chemical analysis of surfaces. We will present novel results of XPS on unsupported, gas-phase nanoparticles using a velocity-map imaging (VMI) spectrometer. This technique allows for probes of both the surfaces of nanoparticles via XPS as well as their interiors via near edge X-ray absorption fine structure (NEXAFS) spectroscopy. A recent application of this technique has confirmed that arginine's guanidinium group exists in a protonated state even in strongly basic solution. Moreover, the core-level photoelectron spectroscopy can provide information on the effective attenuation length (EAL) of low kinetic energy electrons. This contradictory value is important for determining the probing depth of XPS and in photolithography. A new method for determining EALs will be presented.

Cavity-enhanced frequency doubling from 795nm to 397.5nm ultra-violet coherent radiation with PPKTP crystals in the low pump power regime.

PubMed

Wen, Xin; Han, Yashuai; Bai, Jiandong; He, Jun; Wang, Yanhua; Yang, Baodong; Wang, Junmin

2014-12-29

We demonstrate a simple, compact and cost-efficient diode laser pumped frequency doubling system at 795 nm in the low power regime. In two configurations, a bow-tie four-mirror ring enhancement cavity with a PPKTP crystal inside and a semi-monolithic PPKTP enhancement cavity, we obtain 397.5nm ultra-violet coherent radiation of 35mW and 47mW respectively with a mode-matched fundamental power of about 110mW, corresponding to a conversion efficiency of 32% and 41%. The low loss semi-monolithic cavity leads to the better results. The constructed ultra-violet coherent radiation has good power stability and beam quality, and the system has huge potential in quantum optics and cold atom physics.

Electronic and Photoelectron Spectroscopy of Toluene

NASA Astrophysics Data System (ADS)

Gardner, Adrian M.; Green, Alistair M.; Tame-Reyes, Victor; Wright, Timothy G.

2012-06-01

Electronic and photoelectron spectra of toluene are presented and discussed. The utilization of a recently reported scheme for assigning the normal vibrations of substituted benzenes allows these spectra to be compared to those of other molecules with unprecedented clarity. Changes in vibrational activity within a series of substituted benzene molecules will be discussed, specifically the increased rate of intramolecular vibrational energy redistribution observed in molecules where the substituent is a methyl group. A. M. Gardner and T. G. Wright, J. Chem. Phys., 135, 114305 (2011)

Emitter-site-selective photoelectron circular dichroism of trifluoromethyloxirane

DOE PAGES

Ilchen, M.; Hartmann, G.; Rupprecht, P.; ...

2017-05-30

The angle-resolved inner-shell photoionization of R-trifluoromethyloxirane, C 3H 3F 3O, is studied experimentally and theoretically. Thereby, we investigate the photoelectron circular dichroism (PECD) for nearly symmetric O 1s and F 1s electronic orbitals, which are localized on different molecular sites. The respective dichroic β 1 and angular distribution β 2 parameters are measured at the photoelectron kinetic energies from 1 to 16 eV by using variably polarized synchrotron radiation and velocity map imaging spectroscopy. The present experimental results are in good agreement with the outcome of ab initio electronic structure calculations. We report a sizable chiral asymmetry β 1 ofmore » up to about 9% for the K -shell photoionization of oxygen atom. For the individual fluorine atoms, the present calculations predict asymmetries of similar size. However, being averaged over all fluorine atoms, it drops down to about 2%, as also observed in the present experiment. Our study demonstrates a strong emitter and site sensitivity of PECD in the one-photon inner-shell ionization of this chiral molecule.« less

Cold urticaria. Dissociation of cold-evoked histamine release and urticara following cold challenge.

PubMed

Keahey, T M; Greaves, M W

1980-02-01

Nine patients with acquired cold urticaria were studied to assess the effects of beta-adrenergic agents, xanthines, and corticosteroids on cold-evoked histamine release from skin in vivo. The patients, in all of whom an immediate urticarial response developed after cooling of the forearm, demonstrated release of histamine into the venous blood draining that forearm. Following treatment with aminophylline and albuterol in combination or prednisone alone, suppression of histamine release occurred in all but one patient. In some patients, this was accompanied by a subjective diminution in pruritus or buring, but there was no significant improvement in the ensuing edema or erythema. In one patient, total suppression of histamine release was achieved without any effect on whealing and erythema in response to cold challenge. Our results suggest that histamine is not central to the pathogenesis of vascular changes in acquired cold urticaria.

Bio-inspired photo-electronic material based on photosynthetic proteins

NASA Astrophysics Data System (ADS)

Lebedev, Nikolai; Trammell, Scott A.; Tsoi, Stanislav; Spano, Anthony; Kim, Jin Ho; Xu, Jimmy; Twigg, Mark E.; Schnur, Joel M.

2009-08-01

The construction of efficient light energy converting (photovoltaic and photo-electronic) devices is a current and great challenge in science and technology and one that will have important economic consequences. Several innovative nanoelectronic materials were proposed to achieve this goal, semiconductor quantum dots, metallic nanowires and carbon nanotubes (CNT) are among them. As a charge separating unit for light energy conversion, we propose the utilization of the most advanced photoelectronic material developed by nature, photosynthetic reaction center proteins. As a first step in this direction, we constructed a novel bioinorganic nanophotoelectronic material with photoactive photosynthetic reaction center (RC) proteins encapsulated inside a multiwall CNT arrayed electrode. The material consists of photosynthetic RC-cytochrome complexes acting as charge separating units bound to the inner walls of a CNT electrode and ubiquinone-10 (Q2) serving as a soluble electron-transfer mediator to the counter electrode. The proteins were immobilized inside carbon nanotubes by a Ni(NTA)-alkane-pyrene linker, forming a self-assembled monolayer (SAM) on the surface of inner CNT walls and allowing for unidirectional protein orientation. The material demonstrates an enhanced photoinduced electron transfer rate and shows substantial improvement in photocurrent density compared to that obtained with the same proteins when immobilized on planar graphite (HOPG) electrode. The results suggest that protein encapsulation in precisely organized arrayed tubular electrode architecture can considerably improve the performance of photovoltaic, photoelectronic, or biofuel cell devices. They demonstrate the potential for substantial advantages of precisely organized nano electrode tubular arrayed architecture for variety biotechnological applications.

Optical characterization of ultra-sensitive TES bolometers for SAFARI

NASA Astrophysics Data System (ADS)

Audley, Michael D.; de Lange, Gerhard; Gao, Jian-Rong; Khosropanah, Pourya; Mauskopf, Philip D.; Morozov, Dmitry; Trappe, Neil A.; Doherty, Stephen; Withington, Stafford

2014-07-01

We have characterized the optical response of prototype detectors for SAFARI, the far-infrared imaging spectrometer for the SPICA satellite. SAFARI's three bolometer arrays will image a 2'×2' field of view with spectral information over the wavelength range 34—210 μm. SAFARI requires extremely sensitive detectors (goal NEP ~ 0.2 aW/√Hz), with correspondingly low saturation powers (~5 fW), to take advantage of SPICA's cooled optics. We have constructed an ultra-low background optical test facility containing an internal cold black-body illuminator and have recently added an internal hot black-body source and a light-pipe for external illumination. We illustrate the performance of the test facility with results including spectral-response measurements. Based on an improved understanding of the optical throughput of the test facility we find an optical efficiency of 60% for prototype SAFARI detectors.

Symmetry adapted cluster-configuration interaction calculation of the photoelectron spectra of famous biological active steroids

NASA Astrophysics Data System (ADS)

Abyar, Fatemeh; Farrokhpour, Hossein

2014-11-01

The photoelectron spectra of some famous steroids, important in biology, were calculated in the gas phase. The selected steroids were 5α-androstane-3,11,17-trione, 4-androstane-3,11,17-trione, cortisol, cortisone, corticosterone, dexamethasone, estradiol and cholesterol. The calculations were performed employing symmetry-adapted cluster/configuration interaction (SAC-CI) method using the 6-311++G(2df,pd) basis set. The population ratios of conformers of each steroid were calculated and used for simulating the photoelectron spectrum of steroid. It was found that more than one conformer contribute to the photoelectron spectra of some steroids. To confirm the calculated photoelectron spectra, they compared with their corresponding experimental spectra. There were no experimental gas phase Hesbnd I photoelectron spectra for some of the steroids of this work in the literature and their calculated spectra can show a part of intrinsic characteristics of this molecules in the gas phase. The canonical molecular orbitals involved in the ionization of each steroid were calculated at the HF/6-311++g(d,p) level of theory. The spectral bands of each steroid were assigned by natural bonding orbital (NBO) calculations. Knowing the electronic structures of steroids helps us to understand their biological activities and find which sites of steroid become active when a modification is performing under a biological pathway.

Photoelectron Holographic Atomic Arrangement Imaging of Cleaved Bimetal-intercalated Graphite Superconductor Surface

PubMed Central

Matsui, Fumihiko; Eguchi, Ritsuko; Nishiyama, Saki; Izumi, Masanari; Uesugi, Eri; Goto, Hidenori; Matsushita, Tomohiro; Sugita, Kenji; Daimon, Hiroshi; Hamamoto, Yuji; Hamada, Ikutaro; Morikawa, Yoshitada; Kubozono, Yoshihiro

2016-01-01

From the C 1s and K 2p photoelectron holograms, we directly reconstructed atomic images of the cleaved surface of a bimetal-intercalated graphite superconductor, (Ca, K)C8, which differed substantially from the expected bulk crystal structure based on x-ray diffraction (XRD) measurements. Graphene atomic images were collected in the in-plane cross sections of the layers 3.3 Å and 5.7 Å above the photoelectron emitter C atom and the stacking structures were determined as AB- and AA-type, respectively. The intercalant metal atom layer was found between two AA-stacked graphenes. The K atomic image revealing 2 × 2 periodicity, occupying every second centre site of C hexagonal columns, was reconstructed, and the Ca 2p peak intensity in the photoelectron spectra of (Ca, K)C8 from the cleaved surface was less than a few hundredths of the K 2p peak intensity. These observations indicated that cleavage preferentially occurs at the KC8 layers containing no Ca atoms. PMID:27811975

Photoelectron imaging of autoionizing states of xenon: Effect of external electric fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shubert, V. Alvin; Pratt, Stephen T.

Velocity map photoelectron imaging was used to study the photoelectron angular distributions of autoionizing Stark states of atomic xenon excited just below the Xe{sup +} {sup 2} P{sub 1/2}{sup o} threshold at fields ranging from 50 to 700 V/cm. Two-color, two-photon resonant, three-photon excitation via the 6p{sup '}[1/2]{sub 0} level was used to probe the region of interest. The wavelength scans show a similar evolution of structure to that observed in single-photon excitation [Ernst et al., Phys. Rev. A 37, 4172 (1988)]. The photoelectron angular distributions following autoionization of the Stark states provide information on the decay of excited statesmore » in electron fields. In the present experiments, the large autoionization width of the ({sup 2} P{sub 1/2}{sup o})nd[3/2]{sub 1}{sup o} series dominates the decay processes, and thus controls the angular distributions. However, the angular distributions of the Stark states also indicate the presence of other decay channels contributing to the decay of these states.« less

Photoelectron Spectroscopy for Identification of Chemical States

NASA Technical Reports Server (NTRS)

Novakov, T.

1971-01-01

The technique of X-ray photoelectron spectroscopy and the fundamental electronic interactions constituting the basis of the method will be discussed. The method provides information about chemical states ("oxidation states") of atoms in molecules. In addition, quantitative elemental analysis can be performed using the same method. On the basis of this information identification of chemical species is possible. Examples of applications are discussed with particular references to the study of smog particulate matter.

Novel ways of creating and detecting topological order with cold atoms and ions

NASA Astrophysics Data System (ADS)

Lewenstein, Maciej

2015-03-01

In my talk I will focus on novel physics and novel quantum phases that are expected in lattice systems of ultra-cold atoms or ions in synthetic gauge fields, generated via lattice modulations and shaking. I will discuss fractal energy spectra and topological phases in long-range spin chains realized with trapped ions or atoms in nanofibers, and synthetic gauge fields in synthetic dimensions. I will spend large part of the talk discussing the ways to detect topological effects and order, via tomography of band insulators from quench dynamics, or via direct imaging of topological edge states. This work was supported by ERC AdG OSYRIS, EU IP SIQS, EU STREP EQUAM and Spanish Ministry Grant FOQUS.

Development of an Amorphous Selenium-Based Photodetector Driven by a Diamond Cold Cathode

PubMed Central

Masuzawa, Tomoaki; Saito, Ichitaro; Yamada, Takatoshi; Onishi, Masanori; Yamaguchi, Hisato; Suzuki, Yu; Oonuki, Kousuke; Kato, Nanako; Ogawa, Shuichi; Takakuwa, Yuji; Koh, Angel T. T.; Chua, Daniel H. C.; Mori, Yusuke; Shimosawa, Tatsuo; Okano, Ken

2013-01-01

Amorphous-selenium (a-Se) based photodetectors are promising candidates for imaging devices, due to their high spatial resolution and response speed, as well as extremely high sensitivity enhanced by an internal carrier multiplication. In addition, a-Se is reported to show sensitivity against wide variety of wavelengths, including visible, UV and X-ray, where a-Se based flat-panel X-ray detector was proposed. In order to develop an ultra high-sensitivity photodetector with a wide detectable wavelength range, a photodetector was fabricated using a-Se photoconductor and a nitrogen-doped diamond cold cathode. In the study, a prototype photodetector has been developed, and its response to visible and ultraviolet light are characterized. PMID:24152932

Achieving Zero Current for Polar Wind Outflow on Open Flux Tubes Subjected to Large Photoelectron Fluxes

NASA Technical Reports Server (NTRS)

Wilson, G. R.; Khazanov, G.; Horwitz, J. L.

1997-01-01

In this study we investigate how the condition of zero current on open flux tubes with polar wind outflow, subjected to large photoelectron fluxes, can be achieved. We employ a steady state collisionless semikinetic model to determine the density profiles of O(+), H(+), thermal electrons and photoelectrons coming from the ionosphere along with H(+), ions and electrons coming from the magnetosphere. The model solution attains a potential distribution which both satisfies the condition of charge neutrality and zero current. For the range of parameters considered in this study we find that a 45-60 volt discontinuous potential drop may develop to reflect most of the photoelectrons back toward the ionosphere. This develops because the downward flux of electrons from the magnetosphere to the ionosphere on typical open flux tubes (e.g. the polar rain) appears to be insufficient to balance the photoelectron flux from the ionosphere.

Global transcriptional profiling of a cold-tolerant rice variety under moderate cold stress reveals different cold stress response mechanisms.

PubMed

Zhao, Junliang; Zhang, Shaohong; Yang, Tifeng; Zeng, Zichong; Huang, Zhanghui; Liu, Qing; Wang, Xiaofei; Leach, Jan; Leung, Hei; Liu, Bin

2015-07-01

Gene expression profiling under severe cold stress (4°C) has been conducted in plants including rice. However, rice seedlings are frequently exposed to milder cold stresses under natural environments. To understand the responses of rice to milder cold stress, a moderately low temperature (8°C) was used for cold treatment prior to genome-wide profiling of gene expression in a cold-tolerant japonica variety, Lijiangxintuanheigu (LTH). A total of 5557 differentially expressed genes (DEGs) were found at four time points during moderate cold stress. Both the DEGs and differentially expressed transcription factor genes were clustered into two groups based on their expression, suggesting a two-phase response to cold stress and a determinative role of transcription factors in the regulation of stress response. The induction of OsDREB2A under cold stress is reported for the first time in this study. Among the anti-oxidant enzyme genes, glutathione peroxidase (GPX) and glutathione S-transferase (GST) were upregulated, suggesting that the glutathione system may serve as the main reactive oxygen species (ROS) scavenger in LTH. Changes in expression of genes in signal transduction pathways for auxin, abscisic acid (ABA) and salicylic acid (SA) imply their involvement in cold stress responses. The induction of ABA response genes and detection of enriched cis-elements in DEGs suggest that ABA signaling pathway plays a dominant role in the cold stress response. Our results suggest that rice responses to cold stress vary with the specific temperature imposed and the rice genotype. © 2014 Scandinavian Plant Physiology Society.

Consumers' conceptualization of ultra-processed foods.

PubMed

Ares, Gastón; Vidal, Leticia; Allegue, Gimena; Giménez, Ana; Bandeira, Elisa; Moratorio, Ximena; Molina, Verónika; Curutchet, María Rosa

2016-10-01

Consumption of ultra-processed foods has been associated with low diet quality, obesity and other non-communicable diseases. This situation makes it necessary to develop educational campaigns to discourage consumers from substituting meals based on unprocessed or minimally processed foods by ultra-processed foods. In this context, the aim of the present work was to investigate how consumers conceptualize the term ultra-processed foods and to evaluate if the foods they perceive as ultra-processed are in concordance with the products included in the NOVA classification system. An online study was carried out with 2381 participants. They were asked to explain what they understood by ultra-processed foods and to list foods that can be considered ultra-processed. Responses were analysed using inductive coding. The great majority of the participants was able to provide an explanation of what ultra-processed foods are, which was similar to the definition described in the literature. Most of the participants described ultra-processed foods as highly processed products that usually contain additives and other artificial ingredients, stressing that they have low nutritional quality and are unhealthful. The most relevant products for consumers' conceptualization of the term were in agreement with the NOVA classification system and included processed meats, soft drinks, snacks, burgers, powdered and packaged soups and noodles. However, some of the participants perceived processed foods, culinary ingredients and even some minimally processed foods as ultra-processed. This suggests that in order to accurately convey their message, educational campaigns aimed at discouraging consumers from consuming ultra-processed foods should include a clear definition of the term and describe some of their specific characteristics, such as the type of ingredients included in their formulation and their nutritional composition. Copyright © 2016 Elsevier Ltd. All rights reserved.

The cold driver: Cold stress while driving results in dangerous behavior.

PubMed

Morris, Drew M; Pilcher, June J

2016-10-01

Cool vehicle cabin temperatures can induce short-term non-hypothermic cold stress. The current study created a cold condition to examine the impact of cold stress on driving behavior. Forty-four participants drove a high-fidelity driving simulator during a thermal neutral or local torso cooled condition. Participants performed additional tasks to assess attention, psychomotor vigilance, and manual dexterity. Skin temperature was significantly lower in the cold condition while internal temperature was unaffected. Participants who had higher subjective ratings of cold followed lead vehicles closer and started to brake later. Participants in the cold condition followed the lead car 22% (0.82s) closer and started braking 20% (2.35s) later when approaching a stop sign during the car-following task. No change in attention, psychomotor vigilance, or dexterity was observed. The current results suggest that cold environmental conditions can contribute to dangerous driving behaviors. Measures of cold perception were also shown to predict changes in driving behavior. Copyright © 2016 Elsevier B.V. All rights reserved.

Cold-hearted or cool-headed: physical coldness promotes utilitarian moral judgment

PubMed Central

Nakamura, Hiroko; Ito, Yuichi; Honma, Yoshiko; Mori, Takuya; Kawaguchi, Jun

2014-01-01

In the current study, we examine the effect of physical coldness on personal moral dilemma judgment. Previous studies have indicated that utilitarian moral judgment—sacrificing a few people to achieve the greater good for others—was facilitated when: (1) participants suppressed an initial emotional response and deliberately thought about the utility of outcomes; (2) participants had a high-level construal mindset and focused on abstract goals (e.g., save many); or (3) there was a decreasing emotional response to sacrificing a few. In two experiments, we exposed participants to extreme cold or typical room temperature and then asked them to make personal moral dilemma judgments. The results of Experiment 1 indicated that coldness prompted utilitarian judgment, but the effect of coldness was independent from deliberate thought or abstract high-level construal mindset. As Experiment 2 revealed, coldness facilitated utilitarian judgment via reduced empathic feelings. Therefore, physical coldness did not affect the “cool-headed” deliberate process or the abstract high-level construal mindset. Rather, coldness biased people toward being “cold-hearted,” reduced empathetic concern, and facilitated utilitarian moral judgments. PMID:25324800

Photoelectron Spectroscopy of Substituted Phenylnitrenes

NASA Astrophysics Data System (ADS)

Wijeratne, Neloni R.; Da Fonte, Maria; Wenthold, Paul G.

2009-06-01

Nitrenes are unusual molecular structures with unfilled electronic valences that are isoelectronic with carbenes. Although, both can be generated by either thermal or photochemical decomposition of appropriate precursors they usually exhibit different reactivities. In this work, we carry out spectroscopic studies of substituted phenylnitrene to determine how the introduction of substituents will affect the reactivity and its thermochemical properties. All studies were carried out by using the newly constructed time-of-flight negative ion photoelectron spectrometer (NIPES) at Purdue University. The 355 nm photoelectron spectra of the o-, m-, and p-chlorophenyl nitrene anions are fairly similar to that measured for phenylnitrene anion. All spectra show low energy triplet state and a high energy singlet state. The singlet state for the meta isomer is well-resolved, with a well defined origin and observable vibrational structure. Whereas the singlet states for the ortho and para isomers have lower energy onsets and no resolved structure. The isomeric dependence suggests that the geometry differences result from the resonance interaction between the nitrogen and the substituent. Quinoidal resonance structures are possible for the open-shell singlet states of the o- and p-chlorinated phenyl nitrenes. The advantages of this type of electronic structures for the open-shell singlet states is that the unpaired electrons can be more localized on separate atoms in the molecules, minimizing the repulsion between. Because the meta position is not in resonance with the nitrenes, substitution at that position should not affect the structure of the open-shell singlet state. The measured electron affinities (EA) of the triplet phenylnitrenes are in excellent agreement with the values predicted by electronic structure calculations. The largest EA, 1.82 eV is found for the meta isomer, with para being the smallest, 1.70 eV.

Interactions of gaseous molecules with X-ray photons and photoelectrons in AP-XPS study of solid surface in gas phase.

PubMed

Tao, Franklin Feng; Nguyen, Luan

2018-04-18

Studies of the surface of a catalyst in the gas phase via photoelectron spectroscopy is an important approach to establish a correlation between the surface of a catalyst under reaction conditions or during catalysis and its corresponding catalytic performance. Unlike the well understood interactions between photoelectrons and the atomic layers of a surface in ultrahigh vacuum (UHV) and the well-developed method of quantitative analysis of a solid surface in UHV, a fundamental understanding of the interactions between X-ray photons and gaseous molecules and between photoelectrons and molecules of the gas phase in ambient pressure X-ray photoelectron spectroscopy (AP-XPS) is lacking. Through well designed experiments, here the impact of the interactions between photoelectrons and gaseous molecules and interactions between X-ray photons and gaseous molecules on the intensity of the collected photoelectrons have been explored. How the changes in photoelectron intensity resulting from these interactions influence measurement of the authentic atomic ratio of element M to A of a solid surface has been discussed herein, and methods to correct the measured nominal atomic ratio of two elements of a solid surface upon travelling through a gas phase to its authentic atomic ratio have been developed.

Theory of time-resolved photoelectron imaging. Comparison of a density functional with a time-dependent density functional approach

NASA Astrophysics Data System (ADS)

Suzuki, Yoshi-ichi; Seideman, Tamar; Stener, Mauro

2004-01-01

Time-resolved photoelectron differential cross sections are computed within a quantum dynamical theory that combines a formally exact solution of the nuclear dynamics with density functional theory (DFT)-based approximations of the electronic dynamics. Various observables of time-resolved photoelectron imaging techniques are computed at the Kohn-Sham and at the time-dependent DFT levels. Comparison of the results serves to assess the reliability of the former method and hence its usefulness as an economic approach for time-domain photoelectron cross section calculations, that is applicable to complex polyatomic systems. Analysis of the matrix elements that contain the electronic dynamics provides insight into a previously unexplored aspect of femtosecond-resolved photoelectron imaging.

Rosetta Langmuir Probe Photoelectron Emission and Solar Ultraviolet Flux at Comet 67P

NASA Astrophysics Data System (ADS)

Johansson, F. L.; Odelstad, E.; Paulsson, J. J.; Harang, S. S.; Eriksson, A. I.; Mannel, T.; Vigren, E.; Edberg, N. J. T.; Miloch, W. J.; Simon Wedlund, C.; Thiemann, E.; Epavier, F.; Andersson, L.

2017-12-01

The Langmuir Probe instrument on Rosetta monitored the photoelectron emission current of the probes during the Rosetta mission at comet 67P/Churyumov-Gerasimenko, in essence acting as a photodiode monitoring the solar ultraviolet radiation at wavelengths below 250 nm. We have used three methods of extracting the photoelectron saturation current from the Langmuir probe measurements. The resulting dataset can be used as an index of the solar far and extreme ultraviolet at the Rosetta spacecraft position, including flares, in wavelengths that are important for photoionisation of the cometary neutral gas. Comparing the photoemission current to data measurements by MAVEN/EUVM and TIMED/SEE, we find good correlation when 67P was at large heliocentric distances early and late in the mission, but up to 50 percent decrease of the expected photoelectron current at perihelion. We discuss possible reasons for the photoemission decrease, including scattering and absorption by nanograins created by disintegration of cometary dust far away from the nucleus.

Quantitative interpretation of molecular dynamics simulations for X-ray photoelectron spectroscopy of aqueous solutions

NASA Astrophysics Data System (ADS)

Olivieri, Giorgia; Parry, Krista M.; Powell, Cedric J.; Tobias, Douglas J.; Brown, Matthew A.

2016-04-01

Over the past decade, energy-dependent ambient pressure X-ray photoelectron spectroscopy (XPS) has emerged as a powerful analytical probe of the ion spatial distributions at the vapor (vacuum)-aqueous electrolyte interface. These experiments are often paired with complementary molecular dynamics (MD) simulations in an attempt to provide a complete description of the liquid interface. There is, however, no systematic protocol that permits a straightforward comparison of the two sets of results. XPS is an integrated technique that averages signals from multiple layers in a solution even at the lowest photoelectron kinetic energies routinely employed, whereas MD simulations provide a microscopic layer-by-layer description of the solution composition near the interface. Here, we use the National Institute of Standards and Technology database for the Simulation of Electron Spectra for Surface Analysis (SESSA) to quantitatively interpret atom-density profiles from MD simulations for XPS signal intensities using sodium and potassium iodide solutions as examples. We show that electron inelastic mean free paths calculated from a semi-empirical formula depend strongly on solution composition, varying by up to 30% between pure water and concentrated NaI. The XPS signal thus arises from different information depths in different solutions for a fixed photoelectron kinetic energy. XPS signal intensities are calculated using SESSA as a function of photoelectron kinetic energy (probe depth) and compared with a widely employed ad hoc method. SESSA simulations illustrate the importance of accounting for elastic-scattering events at low photoelectron kinetic energies (<300 eV) where the ad hoc method systematically underestimates the preferential enhancement of anions over cations. Finally, some technical aspects of applying SESSA to liquid interfaces are discussed.

Sex Difference in Draft-Legal Ultra-Distance Events - A Comparison between Ultra-Swimming and Ultra-Cycling.

PubMed

Salihu, Lejla; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat

2016-04-30

Recent studies reported that the sex difference in performance in ultra-endurance sports such as swimming and cycling changed over the years. However, the aspect of drafting in draft-legal ultra-endurance races has not yet been investigated. This study investigates the sex difference in ultra-swimming and ultra-cycling draft-legal races where drafting - swimming or cycling behind other participants to save energy and have more power at the end of the race to overtake them, is allowed. The change in performance of the annual best and the annual three best in an ultra-endurance swimming race (16-km 'Faros Swim Marathon') over 38 years and in a 24-h ultra-cycling race ('World Cycling Race') over 13 years were compared and analysed with respect to sex difference. Furthermore, performances of the fastest female and male finishers ever were compared. In the swimming event, the sex difference of the annual best male and female decreased non-significantly (P = 0.262) from 5.3% (1976) to 1.0% (2013). The sex gap of speed in the annual three fastest swimmers decreased significantly (P = 0.043) from 5.9 ± 1.6% (1979) to 4.7 ± 3.1% (2013). In the cycling event, the difference in cycling speed between the annual best male and female decreased significantly (P = 0.026) from 33.31% (1999) to 10.89% (2011). The sex gap of speed in the annual three fastest decreased significantly (P = 0.001) from 32.9 ± 0.6% (1999) to 16.4 ± 5.9% (2011). The fastest male swimmer ever (swimming speed 5.3 km/h, race time: 03:01:55 h:min:s) was 1.5% faster than the fastest female swimmer (swimming speed 5.2 km/h, race time: 03:04:09 h:min:s). The three fastest male swimmers ever (mean 5.27 ± 0.13 km/h) were 4.4% faster than the three fastest female swimmers (mean 5.05 ± 0.20 km/h) (P < 0.05). In the cycling event, the best male ever (cycling speed 45.8 km/h) was 26.4% faster than the best female (cycling speed 36.1 km/h). The three fastest male cyclists ever (45.9 km/h) (mean 45.85 ± 0.05 km

High-throughput Toroidal Grating Beamline for Photoelectron Spectroscopy at CAMD

PubMed Central

Kizilkaya, O; Jiles, R W; Patterson, M C; Thibodeaux, C A; Poliakoff, E D; Sprunger, P T; Kurtz, R L; Morikawa, E

2016-01-01

A 5 meter toroidal grating (5m-TGM) beamline has been commissioned to deliver 28 mrad of bending magnet radiation to an ultrahigh vacuum endstation chamber to facilitate angle resolved photoelectron spectroscopy. The 5m-TGM beamline is equipped with Au-coated gratings with 300, 600 and 1200 lines/mm providing monochromatized synchrotron radiation in the energy ranges 25-70 eV, 50–120 eV and 100–240 eV, respectively. The beamline delivers excellent flux (~1014-1017 photons/sec/100mA) and a combined energy resolution of 189 meV for the beamline (at 1.0 mm slit opening) and HA-50 hemispherical analyzer was obtained at the Fermi level of polycrystalline gold crystal. Our preliminary photoelectron spectroscopy results of phenol adsorption on TiO2 (110) surface reveals the metal ion (Ti) oxidation. PMID:27134636

Cold symptoms (image)

MedlinePlus

Colds are caused by a virus and can occur year-round. The common cold generally involves a runny nose, nasal congestion, and ... symptoms include sore throat, cough, and headache. A cold usually lasts about 7 days, with perhaps a ...

Combined angle-resolved X-ray photoelectron spectroscopy, density functional theory and kinetic study of nitridation of gallium arsenide

NASA Astrophysics Data System (ADS)

Mehdi, H.; Monier, G.; Hoggan, P. E.; Bideux, L.; Robert-Goumet, C.; Dubrovskii, V. G.

2018-01-01

The high density of interface and surface states that cause the strong Fermi pinning observed on GaAs surfaces can be reduced by depositing GaN ultra-thin films on GaAs. To further improve this passivation, it is necessary to investigate the nitridation phenomena by identifying the distinct steps occurring during the process and to understand and quantify the growth kinetics of GaAs nitridation under different conditions. Nitridation of the cleaned GaAs substrate was performed using N2 plasma source. Two approaches have been combined. Firstly, an AR-XPS (Angle Resolved X-ray Photoelectron Spectroscopy) study is carried out to determine the chemical environments of the Ga, As and N atoms and the composition depth profile of the GaN thin film which allow us to summarize the nitridation process in three steps. Moreover, the temperature and time treatment have been investigated and show a significant impact on the formation of the GaN layer. The second approach is a refined growth kinetic model which better describes the GaN growth as a function of the nitridation time. This model clarifies the exchange mechanism of arsenic with nitrogen atoms at the GaN/GaAs interface and the phenomenon of quasi-saturation of the process observed experimentally.

Coping with Cold Sores

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cold Sores KidsHealth / For Kids / Cold Sores What's in ... sore." What's that? Adam wondered. What Is a Cold Sore? Cold sores are small blisters that is ...

[Effects of covering the windowpane with plastic film on microclimate and sunshine of the living room in a cold region].

PubMed

Peng, G H

1990-05-01

Experiments were made to ascertain the effects of covering windowpane with plastic film in Hulunbeir region on microclimate and sunshine intensity in the living room. It was found that a good regulative effect on the room microclimate resulted by covering the windowpane with plastic film in the cold region. The room temperature rose distinctly. No evident effects were found on ultra-violet radiation and illumination. But the concentration of carbon dioxide increased to some extent. Attention should be paid to ventilation of the room.

Cold Stress and the Cold Pressor Test

ERIC Educational Resources Information Center

Silverthorn, Dee U.; Michael, Joel

2013-01-01

Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This…

Recent applications of hard x-ray photoelectron spectroscopy

DOE PAGES

Weiland, Conan; Rumaiz, Abdul K.; Pianetta, Piero; ...

2016-05-05

Recent applications of hard x-ray photoelectron spectroscopy (HAXPES) demonstrate its many capabilities in addition to several of its limitations. Examples are given, including measurement of buried interfaces and materials under in-situ or in-operando conditions, as well as measurements under x-ray standing-wave and resonant excitation. We also present physical considerations that differentiate HAXPES from photoemission measurements utilizing soft and ultraviolet x rays.

Hair sensor using a photoelectronic principle for sensing airflow and its direction

NASA Astrophysics Data System (ADS)

Huang, Kuang-Yuh; Huang, Chien-Tai

2011-01-01

Many organisms have diverse hair cells to instantaneously perceive the change of surroundings so that they can keep away from threats. These organs can precisely detect the tiny variations of airflow, water flow, sound, or pressure, and also resolve their affecting directions. Through this brilliant inspiration by the insects' cilia, we decided to design and develop a hair sensor for detecting two-dimensional airflow and pressure waves by using photoelectronic principles. The hair sensor inherently consists of an artificial cilium supported by an elastic membrane. A light-emitting diode and a quadrant photodiode are used as the photoelectronic sensor. The airflow or pressure wave directly stimulates the cilium to sway, and this motion contributes to let the projected light beam shift over the quadrant photodiode, whose four photodiodes produce then corresponding output signals. Because of dynamic and high-sensitive properties of the photoelectronic sensor, the hair sensor we developed possesses a high measurement resolution to be able to detect very tiny stimulation and its affecting direction. According to its multifaceted characteristics and simple structure, the hair sensor can be applied in numerous potential application fields, such as intrusion alarm system, noise detection system, as well as a tactile sensor.

Angular distribution of photoelectrons from atomic oxygen, nitrogen and carbon. [in upper atmosphere

NASA Technical Reports Server (NTRS)

Manson, S. J.; Kennedy, D. J.; Starace, A. F.; Dill, D.

1974-01-01

The angular distributions of photoelectrons from atomic oxygen, nitrogen, and carbon are calculated. Both Hartree-Fock and Hartree-Slater (Herman-Skillman) wave functions are used for oxygen, and the agreement is excellent; thus only Hartree-Slater functions are used for carbon and nitrogen. The pitch-angle distribution of photoelectrons is discussed, and it is shown that previous approximations of energy-independent isotropic or sin squared theta distributions are at odds with the authors' results, which vary with energy. This variation with energy is discussed, as is the reliability of these calculations.

A systematic search for dwarf counterparts to ultra compact high velocity clouds

NASA Astrophysics Data System (ADS)

Bennet, Paul; Sand, David J.; Crnojevic, Denija; Strader, Jay

2015-01-01

Observations of the Universe on scales smaller than typical, massive galaxies challenge the standard Lambda Cold Dark Matter paradigm for structure formation. It is thus imperative to discover and characterize the faintest dwarf galaxy systems, not just within the Local Group, but in relatively isolated environments as well in order to properly connect them with models of structure formation. Here we report on a systematic search of public ultraviolet and optical archives for dwarf galaxy counterparts to so-called Ultra Compact High Velocity Clouds (UCHVCs), which are compact, isolated HI sources recently found in the Galactic Arecibo L-band Feed Array-HI (GALFA-HI) and Arecibo Legacy Fast ALFA (ALFALFA-HI) surveys. Our search has uncovered at least three strong dwarf galaxy candidates, and we present their inferred star formation rate and structural properties here.

Cold Urticaria

MedlinePlus

... severe reactions. For some people with this condition, swimming in cold water could lead to very low ... generally occur with full skin exposure, such as swimming in cold water. Such a reaction could lead ...

The Far Ultra-Violet Imager on the Icon Mission

NASA Astrophysics Data System (ADS)

Mende, S. B.; Frey, H. U.; Rider, K.; Chou, C.; Harris, S. E.; Siegmund, O. H. W.; England, S. L.; Wilkins, C.; Craig, W.; Immel, T. J.; Turin, P.; Darling, N.; Loicq, J.; Blain, P.; Syrstad, E.; Thompson, B.; Burt, R.; Champagne, J.; Sevilla, P.; Ellis, S.

2017-10-01

ICON Far UltraViolet (FUV) imager contributes to the ICON science objectives by providing remote sensing measurements of the daytime and nighttime atmosphere/ionosphere. During sunlit atmospheric conditions, ICON FUV images the limb altitude profile in the shortwave (SW) band at 135.6 nm and the longwave (LW) band at 157 nm perpendicular to the satellite motion to retrieve the atmospheric O/N2 ratio. In conditions of atmospheric darkness, ICON FUV measures the 135.6 nm recombination emission of O+ ions used to compute the nighttime ionospheric altitude distribution. ICON Far UltraViolet (FUV) imager is a Czerny-Turner design Spectrographic Imager with two exit slits and corresponding back imager cameras that produce two independent images in separate wavelength bands on two detectors. All observations will be processed as limb altitude profiles. In addition, the ionospheric 135.6 nm data will be processed as longitude and latitude spatial maps to obtain images of ion distributions around regions of equatorial spread F. The ICON FUV optic axis is pointed 20 degrees below local horizontal and has a steering mirror that allows the field of view to be steered up to 30 degrees forward and aft, to keep the local magnetic meridian in the field of view. The detectors are micro channel plate (MCP) intensified FUV tubes with the phosphor fiber-optically coupled to Charge Coupled Devices (CCDs). The dual stack MCP-s amplify the photoelectron signals to overcome the CCD noise and the rapidly scanned frames are co-added to digitally create 12-second integrated images. Digital on-board signal processing is used to compensate for geometric distortion and satellite motion and to achieve data compression. The instrument was originally aligned in visible light by using a special grating and visible cameras. Final alignment, functional and environmental testing and calibration were performed in a large vacuum chamber with a UV source. The test and calibration program showed that ICON

Relationships of self-identified cold tolerance and cold-induced vasodilatation in the finger

NASA Astrophysics Data System (ADS)

Park, Joonhee; Lee, Joo-Young

2016-04-01

This study was conducted to investigate relationships of self-identified cold tolerance and cold-induced vasodilatation (CIVD) in the finger. Nine males and 34 females participated in the following 2 tests: a CIVD test and a self-reported survey. The CIVD test was conducted 30-min cold-water immersion (3.8 ± 0.3 °C) of the middle finger at an air temperature of 27.9 ± 0.1 °C. The self-reported questionnaire consisted of 28 questions about whole and local body cold and heat tolerances. By a cluster analysis on the survey results, the participants were divided into two groups: high self-identified cold tolerance (HSCT, n = 25) and low self-identified cold tolerance (LSCT, n = 18). LSCT had lower self-identified cold tolerance ( P < 0.001), preferred hot thermal stimulation ( P = 0.006), and wore heavier clothing during daily life ( P < 0.001) than HSCT. LSCT had significantly lower maximal finger temperatures ( T max) ( P = 0.040), smaller amplitude ( P = 0.029), and delayed onset time of CIVD ( P = 0.080) when compared to HSCT. Some questions examining the self-identified cold or heat tolerance had relationships with cold tolerance index, T max, and amplitude ( P < 0.1). These results indicate that self-identified cold tolerance classified through a standardized survey could be a good index to predict physiological cold tolerance.

Relationships of self-identified cold tolerance and cold-induced vasodilatation in the finger.

PubMed

Park, Joonhee; Lee, Joo-Young

2016-04-01

This study was conducted to investigate relationships of self-identified cold tolerance and cold-induced vasodilatation (CIVD) in the finger. Nine males and 34 females participated in the following 2 tests: a CIVD test and a self-reported survey. The CIVD test was conducted 30-min cold-water immersion (3.8 ± 0.3 °C) of the middle finger at an air temperature of 27.9 ± 0.1 °C. The self-reported questionnaire consisted of 28 questions about whole and local body cold and heat tolerances. By a cluster analysis on the survey results, the participants were divided into two groups: high self-identified cold tolerance (HSCT, n = 25) and low self-identified cold tolerance (LSCT, n = 18). LSCT had lower self-identified cold tolerance (P < 0.001), preferred hot thermal stimulation (P = 0.006), and wore heavier clothing during daily life (P < 0.001) than HSCT. LSCT had significantly lower maximal finger temperatures (T max) (P = 0.040), smaller amplitude (P = 0.029), and delayed onset time of CIVD (P = 0.080) when compared to HSCT. Some questions examining the self-identified cold or heat tolerance had relationships with cold tolerance index, T max, and amplitude (P < 0.1). These results indicate that self-identified cold tolerance classified through a standardized survey could be a good index to predict physiological cold tolerance.

Common cold

MedlinePlus

... treatments have been tried for colds, such as vitamin C, zinc supplements, and echinacea. Talk to your health ... Accessed February 1, 2017. Hemila H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane ...

Mechanical properties of Fe -10Ni -7Mn martensitic steel subjected to severe plastic deformation via cold rolling and wire drawing

NASA Astrophysics Data System (ADS)

Ghasemi-Nanesa, H.; Nili-Ahmadabadi, M.; Shirazi, H.

2010-07-01

Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was epsilon ~7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

Analytic quantum-interference conditions in Coulomb corrected photoelectron holography

NASA Astrophysics Data System (ADS)

Maxwell, A. S.; Al-Jawahiry, A.; Lai, X. Y.; Figueira de Morisson Faria, C.

2018-02-01

We provide approximate analytic expressions for above-threshold ionization (ATI) transition probabilities and photoelectron angular distributions. These analytic expressions are more general than those existing in the literature and include the residual binding potential in the electron continuum propagation. They successfully reproduce the ATI side lobes and specific holographic structures such as the near-threshold fan-shaped pattern and the spider-like structure that extends up to relatively high photoelectron energies. We compare such expressions with the Coulomb quantum orbit strong-field approximation (CQSFA) and the full solution of the time-dependent Schrödinger equation for different driving-field frequencies and intensities, and provide an in-depth analysis of the physical mechanisms behind specific holographic structures. Our results shed additional light on what aspects of the CQSFA must be prioritized in order to obtain the key holographic features, and highlight the importance of forward scattered trajectories. Furthermore, we find that the holographic patterns change considerably for different field parameters, even if the Keldysh parameter is kept roughly the same.

Computational and photoelectron spectroscopic study of the dipole-bound anions, indole(H2O)1,2 (.).

PubMed

Buytendyk, A M; Buonaugurio, A M; Xu, S-J; Nilles, J M; Bowen, K H; Kirnosov, N; Adamowicz, L

2016-07-14

We report our joint computational and anion photoelectron spectroscopic study of indole-water cluster anions, indole(H2O)1,2 (-). The photoelectron spectra of both cluster anions show the characteristics of dipole-bound anions, and this is confirmed by our theoretical computations. The experimentally determined vertical electron detachment (VDE) energies for indole(H2O)1 (-) and indole(H2O)2 (-) are 144 meV and 251 meV, respectively. The corresponding theoretically determined VDE values for indole(H2O)1 (-) and indole(H2O)2 (-) are 124 meV and 255 meV, respectively. The vibrational features in the photoelectron spectra of these cluster anions are assigned as the vibrations of the water molecule.

Computational and photoelectron spectroscopic study of the dipole-bound anions, indole(H2O)1,2-

NASA Astrophysics Data System (ADS)

Buytendyk, A. M.; Buonaugurio, A. M.; Xu, S.-J.; Nilles, J. M.; Bowen, K. H.; Kirnosov, N.; Adamowicz, L.

2016-07-01

We report our joint computational and anion photoelectron spectroscopic study of indole-water cluster anions, indole(H2O)1,2-. The photoelectron spectra of both cluster anions show the characteristics of dipole-bound anions, and this is confirmed by our theoretical computations. The experimentally determined vertical electron detachment (VDE) energies for indole(H2O)1- and indole(H2O)2- are 144 meV and 251 meV, respectively. The corresponding theoretically determined VDE values for indole(H2O)1- and indole(H2O)2- are 124 meV and 255 meV, respectively. The vibrational features in the photoelectron spectra of these cluster anions are assigned as the vibrations of the water molecule.

Ultra-Large Solar Sail

NASA Technical Reports Server (NTRS)

Burton, Rodney; Coverstone, Victoria

2009-01-01

UltraSail is a next-generation ultra-large (km2 class) sail system. Analysis of the launch, deployment, stabilization, and control of these sails shows that high-payload-mass fractions for interplanetary and deep-space missions are possible. UltraSail combines propulsion and control systems developed for formation-flying microsatellites with a solar sail architecture to achieve controllable sail areas approaching 1 km2. Electrically conductive CP-1 polyimide film results in sail subsystem area densities as low as 5 g/m2. UltraSail produces thrust levels many times those of ion thrusters used for comparable deep-space missions. The primary innovation involves the near-elimination of sail-supporting structures by attaching each blade tip to a formation- flying microsatellite, which deploys the sail and then articulates the sail to provide attitude control, including spin stabilization and precession of the spin axis. These microsatellite tips are controlled by microthrusters for sail-film deployment and mission operations. UltraSail also avoids the problems inherent in folded sail film, namely stressing, yielding, or perforating, by storing the film in a roll for launch and deployment. A 5-km long by 2 micrometer thick film roll on a mandrel with a 1 m circumference (32 cm diameter) has a stored thickness of 5 cm. A 5 m-long mandrel can store a film area of 25,000 m2, and a four-blade system has an area of 0.1 sq km.

77 FR 59182 - Ultra-Deepwater Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-26

... DEPARTMENT OF ENERGY Ultra-Deepwater Advisory Committee AGENCY: Office of Fossil Energy... of the Ultra-Deepwater Advisory Committee is to provide advice on development and implementation of programs related to ultra-deepwater architecture and technology to the Secretary of Energy and provide...

Experimental Retrieval of Target Structure Information from Laser-Induced Rescattered Photoelectron Momentum Distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okunishi, M.; Pruemper, G.; Shimada, K.

We have measured two-dimensional photoelectron momentum spectra of Ne, Ar, and Xe generated by 800-nm, 100-fs laser pulses and succeeded in identifying the spectral ridge region (back-rescattered ridges) which marks the location of the returning electrons that have been backscattered at their maximum kinetic energies. We demonstrate that the structural information, in particular the differential elastic scattering cross sections of the target ion by free electrons, can be accurately extracted from the intensity distributions of photoelectrons on the ridges, thus effecting a first step toward laser-induced self-imaging of the target, with unprecedented spatial and temporal resolutions.

75 FR 48319 - Ultra-Deepwater Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-10

... DEPARTMENT OF ENERGY Ultra-Deepwater Advisory Committee AGENCY: Department of Energy, Office of...: Purpose of the Committee: The purpose of the Ultra-Deepwater Advisory Committee is to provide advice on development and implementation of programs related to ultra-deepwater architecture and technology to the...

76 FR 77990 - Ultra-Deepwater Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-15

... DEPARTMENT OF ENERGY Ultra-Deepwater Advisory Committee AGENCY: Office of Fossil Energy... Committee: The purpose of the Ultra-Deepwater Advisory Committee is to provide advice to the Secretary of Energy on development and implementation of programs related to ultra-deepwater natural gas and other...

76 FR 6775 - Ultra-Deepwater Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-08

... DEPARTMENT OF ENERGY Ultra-Deepwater Advisory Committee AGENCY: Department of Energy, Office of... Committee: The purpose of the Ultra-Deepwater Advisory Committee is to provide advice on development and implementation of programs related to ultra-deepwater architecture and technology to the Secretary of Energy and...

75 FR 54860 - Ultra Deepwater Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-09

... DEPARTMENT OF ENERGY Ultra Deepwater Advisory Committee AGENCY: Department of Energy, Office of... of an open meeting of the Ultra Deepwater Advisory Committee. The Committee was organized pursuant to.../advisorycommittees/UltraDeepwater.html . Issued in Washington, DC, on September 3, 2010. Carol A. Matthews, Committee...

Human whole body cold adaptation.

PubMed

Daanen, Hein A M; Van Marken Lichtenbelt, Wouter D

2016-01-01

Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold.

Human whole body cold adaptation

PubMed Central

Daanen, Hein A.M.; Van Marken Lichtenbelt, Wouter D.

2016-01-01

ABSTRACT Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold. PMID:27227100

UltraNet Target Parameters. Chapter 1

NASA Technical Reports Server (NTRS)

Kislitzin, Katherine T.; Blaylock, Bruce T. (Technical Monitor)

1992-01-01

The UltraNet is a high speed network capable of rates up to one gigabit per second. It is a hub based network with four optical fiber links connecting each hub. Each link can carry up to 256 megabits of data, and the hub backplane is capable of one gigabit aggregate throughput. Host connections to the hub may be fiber, coax, or channel based. Bus based machines have adapter boards that connect to transceivers in the hub, while channel based machines use a personality module in the hub. One way that the UltraNet achieves its high transfer rates is by off-loading the protocol processing from the hosts to special purpose protocol engines in the UltraNet hubs. In addition, every hub has a PC connected to it by StarLAN for network management purposes. Although there is hub resident and PC resident UltraNet software, this document treats only the host resident UltraNet software.

Circular dichroism in photoelectron images from aligned nitric oxide molecules

DOE PAGES

Sen, Ananya; Pratt, S. T.; Reid, K. L.

2017-05-03

We have used velocity map photoelectron imaging to study circular dichroism of the photoelectron angular distributions (PADs) of nitric oxide following two-color resonanceenhanced two-photon ionization via selected rotational levels of the A 2Σ +, v' = 0 state. By using a circularly polarized pump beam and a counter-propagating, circularly polarized probe beam, cylindrical symmetry is preserved in the ionization process, and the images can be reconstructed using standard algorithms. The VMI set up enables individual ion rotational states to be resolved with excellent collection efficiency, rendering the measurements considerably simpler to perform than previous measurements conducted with a conventional photoelectronmore » spectrometer. The results demonstrate that circular dichroism is observed even when cylindrical symmetry is maintained, and serve as a reminder that dichroism is a general feature of the multiphoton ionization of atoms and molecules. Furthermore, the observed PADs are in good agreement with calculations based on parameters extracted from previous experimental results obtained by using a time-offlight electron spectrometer.« less

Circular dichroism in photoelectron images from aligned nitric oxide molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sen, Ananya; Pratt, S. T.; Reid, K. L.

We have used velocity map photoelectron imaging to study circular dichroism of the photoelectron angular distributions (PADs) of nitric oxide following two-color resonanceenhanced two-photon ionization via selected rotational levels of the A 2Σ +, v' = 0 state. By using a circularly polarized pump beam and a counter-propagating, circularly polarized probe beam, cylindrical symmetry is preserved in the ionization process, and the images can be reconstructed using standard algorithms. The VMI set up enables individual ion rotational states to be resolved with excellent collection efficiency, rendering the measurements considerably simpler to perform than previous measurements conducted with a conventional photoelectronmore » spectrometer. The results demonstrate that circular dichroism is observed even when cylindrical symmetry is maintained, and serve as a reminder that dichroism is a general feature of the multiphoton ionization of atoms and molecules. Furthermore, the observed PADs are in good agreement with calculations based on parameters extracted from previous experimental results obtained by using a time-offlight electron spectrometer.« less

The impact of cold spells on mortality and effect modification by cold spell characteristics

NASA Astrophysics Data System (ADS)

Wang, Lijun; Liu, Tao; Hu, Mengjue; Zeng, Weilin; Zhang, Yonghui; Rutherford, Shannon; Lin, Hualiang; Xiao, Jianpeng; Yin, Peng; Liu, Jiangmei; Chu, Cordia; Tong, Shilu; Ma, Wenjun; Zhou, Maigeng

2016-12-01

In China, the health impact of cold weather has received little attention, which limits our understanding of the health impacts of climate change. We collected daily mortality and meteorological data in 66 communities across China from 2006 to 2011. Within each community, we estimated the effect of cold spell exposure on mortality using a Distributed Lag Nonlinear Model (DLNM). We also examined the modification effect of cold spell characteristics (intensity, duration, and timing) and individual-specific factors (causes of death, age, gender and education). Meta-analysis method was finally used to estimate the overall effects. The overall cumulative excess risk (CER) of non-accidental mortality during cold spell days was 28.2% (95% CI: 21.4%, 35.3%) compared with non-cold spell days. There was a significant increase in mortality when the cold spell duration and intensity increased or occurred earlier in the season. Cold spell effects and effect modification by cold spell characteristics were more pronounced in south China. The elderly, people with low education level and those with respiratory diseases were generally more vulnerable to cold spells. Cold spells statistically significantly increase mortality risk in China, with greater effects in southern China. This effect is modified by cold spell characteristics and individual-level factors.

Working smarter on cold cases: identifying factors associated with successful cold case investigations.

PubMed

Davis, Robert C; Jensen, Carl J; Burgette, Lane; Burnett, Kathryn

2014-03-01

Cold case squads have garnered much attention; however, they have yet to undergo significant empirical scrutiny. In the present study, the authors interviewed investigators and reviewed 189 solved and unsolved cold cases in Washington, D.C., to determine whether there are factors that can predict cold case solvability. In the interviews, new information from witnesses or information from new witnesses was cited as the most prevalent reason for case clearance. The case reviews determined that there were factors in each of the following domains that predicted whether cases would be solved during cold case investigations: Crime Context, Initial Investigation Results, Basis for Opening Cold Case, and Cold Case Investigator Actions. The results suggest that it is possible to prioritize cold case work based on the likelihood of investigations leading to clearances. © 2014 American Academy of Forensic Sciences.

X-ray Photoelectron Spectroscopy (XPS), Rutherford Back Scattering (RBS) studies

NASA Technical Reports Server (NTRS)

Neely, W. C.; Bozak, M. J.; Williams, J. R.

1993-01-01

X-ray photoelectron spectroscopy (XPS), Rutherford Back Scattering (RBS) studies of each of sample received were completed. Since low angle X-ray could not be performed because of instrumentation problems, Auger spectrometry was employed instead. The results of these measurements for each of the samples is discussed in turn.

Intense Vibronic Modulation of the Chiral Photoelectron Angular Distribution Generated by Photoionization of Limonene Enantiomers with Circularly Polarized Synchrotron Radiation.

PubMed

Rafiee Fanood, Mohammad M; Ganjitabar, Hassan; Garcia, Gustavo A; Nahon, Laurent; Turchini, Stefano; Powis, Ivan

2018-04-17

Photoionization of the chiral monoterpene limonene has been investigated using polarized synchrotron radiation between the adiabatic ionization threshold, 8.505 and 23.5 eV. A rich vibrational structure is seen in the threshold photoelectron spectrum and is interpreted using a variety of computational methods. The corresponding photoelectron circular dichroism-measured in the photoelectron angular distribution as a forward-backward asymmetry with respect to the photon direction-was found to be strongly dependent on the vibronic structure appearing in the photoelectron spectra, with the observed asymmetry even switching direction in between the major vibrational peaks. This effect can be ultimately attributed to the sensitivity of this dichroism to small phase shifts between adjacent partial waves of the outgoing photoelectron. These observations have implications for potential applications of this chiroptical technique, where the enantioselective analysis of monoterpene components is of particular interest. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diving into Cold Pools

NASA Astrophysics Data System (ADS)

van den Heever, S. C.; Grant, L. D.; Drager, A. J.

2017-12-01

Cold pools play a significant role in convective storm initiation, organization and longevity. Given their role in convective life cycles, recent efforts have been focused on improving the representation of cold pool processes within weather forecast models, as well as on developing cold pool parameterizations in order to better represent their impacts within global climate models. Understanding the physical processes governing cold pool formation, intensity and dissipation is therefore critical to these efforts. Cold pool characteristics are influenced by numerous factors, including those associated with precipitation formation and evaporation, variations in the environmental moisture and shear, and land surface interactions. The focus of this talk will be on the manner in which the surface characteristics and associated processes impact cold pool genesis and dissipation. In particular, the results from high-resolution modeling studies focusing on the role of sensible and latent heat fluxes, soil moisture and SST will be presented. The results from a recent field campaign examining cold pools over northern Colorado will also be discussed.

Probing dark matter with star clusters: a dark matter core in the ultra-faint dwarf Eridanus II

NASA Astrophysics Data System (ADS)

Contenta, Filippo; Balbinot, Eduardo; Petts, James A.; Read, Justin I.; Gieles, Mark; Collins, Michelle L. M.; Peñarrubia, Jorge; Delorme, Maxime; Gualandris, Alessia

2018-05-01

We present a new technique to probe the central dark matter (DM) density profile of galaxies that harnesses both the survival and observed properties of star clusters. As a first application, we apply our method to the `ultra-faint' dwarf Eridanus II (Eri II) that has a lone star cluster ˜45 pc from its centre. Using a grid of collisional N-body simulations, incorporating the effects of stellar evolution, external tides and dynamical friction, we show that a DM core for Eri II naturally reproduces the size and the projected position of its star cluster. By contrast, a dense cusped galaxy requires the cluster to lie implausibly far from the centre of Eri II (>1 kpc), with a high inclination orbit that must be observed at a particular orbital phase. Our results, therefore, favour a DM core. This implies that either a cold DM cusp was `heated up' at the centre of Eri II by bursty star formation or we are seeing an evidence for physics beyond cold DM.

Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock–induced oxidation

PubMed Central

Borowiec, Anne-Sophie; Sion, Benoit; Chalmel, Frédéric; D. Rolland, Antoine; Lemonnier, Loïc; De Clerck, Tatiana; Bokhobza, Alexandre; Derouiche, Sandra; Dewailly, Etienne; Slomianny, Christian; Mauduit, Claire; Benahmed, Mohamed; Roudbaraki, Morad; Jégou, Bernard; Prevarskaya, Natalia; Bidaux, Gabriel

2016-01-01

Testes of most male mammals present the particularity of being externalized from the body and are consequently slightly cooler than core body temperature (4–8°C below). Although, hypothermia of the testis is known to increase germ cells apoptosis, little is known about the underlying molecular mechanisms, including cold sensors, transduction pathways, and apoptosis triggers. In this study, using a functional knockout mouse model of the cold and menthol receptors, dubbed transient receptor potential melastatine 8 (TRPM8) channels, we found that TRPM8 initiated the cold-shock response by differentially modulating cold- and heat-shock proteins. Besides, apoptosis of germ cells increased in proportion to the cooling level in control mice but was independent of temperature in knockout mice. We also observed that the rate of germ cell death correlated positively with the reactive oxygen species level and negatively with the expression of the detoxifying enzymes. This result suggests that the TRPM8 sensor is a key determinant of germ cell fate under hypothermic stimulation.—Borowiec, A.-S., Sion, B., Chalmel, F., Rolland, A. D., Lemonnier, L., De Clerck, T., Bokhobza, A., Derouiche, S., Dewailly, E., Slomianny, C., Mauduit, C., Benahmed, M., Roudbaraki, M., Jégou, B., Prevarskaya, N., Bidaux, G. Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock–induced oxidation. PMID:27317670

Ultrafast photoelectron spectroscopy of small molecule organic films

NASA Astrophysics Data System (ADS)

Read, Kendall Laine

As research in the field of ultrafast optics has produced shorter and shorter pulses, at an ever-widening range of frequencies, ultrafast spectroscopy has grown correspondingly. In particular, ultrafast photoelectron spectroscopy allows direct observation of electrons in transient or excited states, regardless of the eventual relaxation mechanisms. High-harmonic conversion of 800nm, femtosecond, Ti:sapphire laser pulses allows excite/probe spectroscopy down into atomic core level states. To this end, an ultrafast, X-UV photoelectron spectroscopic system is described, including design considerations for the high-harmonic generation line, the time of flight detector, and the subsequent data collection electronics. Using a similar experimental setup, I have performed several ultrafast, photoelectron excited state decay studies at the IBM, T. J. Watson Research Center. All of the observed materials were electroluminescent thin film organics, which have applications as the emitter layer in organic light emitting devices. The specific materials discussed are: Alq, BAlq, DPVBi, and Alq doped with DCM or DMQA. Alq:DCM is also known to lase at low photoexcitation thresholds. A detailed understanding of the involved relaxation mechanisms is beneficial to both applications. Using 3.14 eV excite, and 26.7 eV probe, 90 fs laser pulses, we have observed the lowest unoccupied molecular orbital (LUMO) decay rate over the first 200 picoseconds. During this time, diffusion is insignificant, and all dynamics occur in the absence of electron transport. With excitation intensities in the range of 100μJ/cm2, we have modeled the Alq, BAlq, and DPVBi decays via bimolecular singlet-singlet annihilation. At similar excitations, we have modeled the Alq:DCM decay via Förster transfer, stimulated emission, and excimeric formation. Furthermore, the Alq:DCM occupied to unoccupied molecular orbital energy gap was seen to shrink as a function of excite-to-probe delay, in accordance with the

Common Cold

MedlinePlus

... cure for the common cold. But there are treatments that can make you feel better while you wait for the cold to go away on its own: Getting plenty of rest Drinking fluids Gargling with warm salt water Using cough drops or throat sprays Taking over-the-counter pain ...

The UltraLightweight Technology for Research in Astronomy (ULTRA) Project

NASA Astrophysics Data System (ADS)

Twarog, B. A.; Anthony-Twarog, B. J.; Shawl, S. J.; Hale, R.; Taghavi, R.; Fesen, R.; Etzel, P. B.; Martin, R.; Romeo, R.

2004-12-01

The collaborative focus of four academic departments (Univ. of Kansas Aerospace Engineering, Univ. of Kansas Physics & Astronomy, San Diego State University Astronomy and Dartmouth College Astronomy) and a private industry partner (Composite Mirror Applications, Inc.-CMA, Inc.) is a three-year plan to develop and test UltraLightweight Technology for Research in Astronomy (ULTRA). The ULTRA technology, using graphite fiber composites to fabricate mirrors and telescope structures, offers a versatile and cost-effective tool for optical astronomy, including the economical fabrication and operation of telescopes ranging from small (1m or smaller) aperture for education and research to extremely large (30m+) segmented telescopes (ELTs). The specific goal of this NSF-funded three-year Major Research Instrumentation project is to design, build, and test a 1m-class optical tube assembly (OTA) and mirrors constructed entirely from composites. In the first year of the project, the team has built and is field-testing two 0.4m prototypes to validate the optical surfaces and figures of the mirrors and to test and refine the structural dynamics of the OTA. Preparation for design and construction of the 1m telescope is underway. When completed in late 2005, the ULTRA telescope will be operated remotely from Mt. Laguna Observatory east of San Diego, where it will undergo a period of intensive optical and imaging tests. A 0.4m prototype OTA with mirrors (12 kg total weight) will be on display at the meeting. Support of this work by NSF through grants AST-0320784 and AST-0321247, NASA grant NCC5-600, the University of Kansas, and San Diego State University is gratefully acknowledged.

Measurement of Photoelectron Emission Using Vacuum Ultraviolet Ray Irradiation

NASA Astrophysics Data System (ADS)

Okamura, Shugo; Iwao, Toru; Yumoto, Motoshige; Miyake, Hiroaki; Nitta, Kumi

2009-01-01

Satellites have come to play many roles depending on their purpose, including communication, weather observation, astronomy observation, and space development. A satellite requires long life and high reliability in such a situation. However, at an altitude of several hundred kilometers, atomic oxygen (AO) is a destructive factor. With density of about 1015 atoms/m3, AO also has high reactivity. As the satellite collides with AO, surface materials of the satellite are degraded, engendering surface roughness and oxidation. Accordingly, it is necessary to monitor the surface conditions. In this study, photoemission characteristics of several materials, such as metals, glasses, and polymers are measured using a deuterium lamp and band pass filters. The threshold energy for photoemission and the quantum efficiency were evaluated from those measurements. Consequently, for the investigated materials the threshold energies for photoelectron emission were found to be 4.9-5.7 eV. The quantum efficiency of metals is about 100 times higher than that of other samples. The quantum efficiency of PS that includes a benzene ring is several times higher than that of either PP or PTFE, suggesting that deteriorated materials emit large amounts of photoelectrons.

Nonfreezing Cold-Induced Injuries

DTIC Science & Technology

2011-01-01

ty in both m i fitary and civilians who work ill cold conditions. Consequently recognition of those at risk , limiting their exposure and the...shown to have a higher risk for local cold injuries when exposed to cold in real life [10]. Felicijan et al found evidence for a significant...in cold conditions. Consequently recognition of those at risk , limiting their exposure and the appropriate and timely use of suitable protective

Interface effects in ultra-thin films: Magnetic and chemical properties

NASA Astrophysics Data System (ADS)

Park, Sungkyun

When the thickness of a magnetic layer is comparable to (or smaller than) the electron mean free path, the interface between magnetic and non-magnetic layers becomes very important factor to determine magnetic properties of the ultra-thin films. The quality of interface can enhance (or reduce) the desired properties. Several interesting physical phenomena were studied using these interface effects. The magnetic anisotropy of ultra-thin Co films is studied as function of non-magnetic underlayer thickness and non- magnetic overlayer materials using ex situ Brillouin light scattering (BLS). I observed that perpendicular magnetic anisotropy (PMA) increases with underlayer thickness and saturates after 5 ML. This saturation can be understood as a relaxation of the in-plane lattice parameter of Au(111) on top of Cu(111) to its bulk value. For the overlayer study, Cu, Al, and Au are used. An Au overlayer gives the largest PMA due to the largest in-plane lattice mismatch between Co and Au. An unusual effect was found by adding an additional layer on top of the Au overlayer. An additional Al capping layer on top of the Au overlayer reduces the PMA significantly. The possible explanation is that the misfit strain at the interface between the Al and the Au can be propagated through the Au layer to affect the magnetic properties of Co even though the in- plane lattice mismatch is less than 1%. Another interesting problem in interface interdiffusion and thermal stability in magnetic tunnel junction (MTJ) structures is studied using X-ray photoelectron spectroscopy (XPS). Since XPS is a very chemically sensitive technique, it allows us to monitor interface interdiffusion of the MTJ structures as-deposited and during post-deposition processing. For the plasma- oxidized samples, Fe only participates in the oxidation reduction process. In contrast to plasma-oxidized samples, there were no noticeable chemical shifts as- deposited and during post-deposition processing in air

Analysis of Ti and TiO2 nanolayers by total reflection X-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Kubala-Kukuś, A.; Banaś, D.; Stabrawa, I.; Szary, K.; Sobota, D.; Majewska, U.; Wudarczyk-Moćko, J.; Braziewicz, J.; Pajek, M.

2018-07-01

Total reflection X-ray photoelectron spectroscopy (TRXPS) is applied in the analysis of Ti and TiO2 nanolayers deposited on silicon and silicon dioxide substrates. The idea of application of total-reflection phenomenon for exciting X-ray used in the XPS technique is briefly discussed. The experimental setup and measurement conditions for the studied Ti and TiO2 layers are presented. The XPS spectra were registered both for the non-total and total reflection regimes. The survey spectra and C1s, N1s, Ti2p and O1s photoelectron peaks are shown. For energy calibration, the position of C1s photoelectron peak was applied (C-C component, binding energy 284.8 eV). The peak to background ratios are discussed as regards the dependence of the excitation angle. An increase of this ratio for the glancing angle 1°, being below critical angle of the X-ray beam and sample material, results in an improvement of XPS detection limit by factor up to 2. In the case of the Ti nanolayer, additionally, the thickness of the overlayer TiO2 is determined. As an example of applying the TRXPS technique, the analysis of Ti nanolayers implanted by highly charged Xe35+ ions of 280 keV energy is discussed. The Xe3d and O1s photoelectron peaks are presented and discussed.

Vitamin C and colds

MedlinePlus

Colds and vitamin C ... is that vitamin C can cure the common cold . However, research about this claim is conflicting. Although ... vitamin C may help reduce how long a cold lasts. They do not protect against getting a ...

Colds and flus - antibiotics

MedlinePlus

Antibiotics - colds and flu ... treat infections that are caused by a virus. Colds and flu are caused by viruses. If you ... J, Ericson K, Werner S. Treatment of the common cold in children and adults. Am Fam Physician. 2012; ...

Ultra Reliability Workshop Introduction

NASA Technical Reports Server (NTRS)

Shapiro, Andrew A.

2006-01-01

This plan is the accumulation of substantial work by a large number of individuals. The Ultra-Reliability team consists of representatives from each center who have agreed to champion the program and be the focal point for their center. A number of individuals from NASA, government agencies (including the military), universities, industry and non-governmental organizations also contributed significantly to this effort. Most of their names may be found on the Ultra-Reliability PBMA website.

[Sports and extreme conditions. Cardiovascular incidence in long term exertion and extreme temperatures (heat, cold)].

PubMed

Melin, B; Savourey, G

2001-06-30

During ultra-endurance exercise, both increase in body temperature and dehydration due to sweat losses, lead to a decrease in central blood volume. The heart rate drift allows maintaining appropriate cardiac output, in order to satisfy both muscle perfusion and heat transfer requirements by increasing skin blood flow. The resulting dehydration can impair thermal regulation and increase the risks of serious accidents as heat stroke. Endurance events, lasting more than 8 hours, result in large sweat sodium chloride losses. Thus, ingestion of large amounts of water with poor salt intake can induce symptomatic hyponatremia (plasma sodium < 130 mEq/L) which is also a serious accident. Heat environment increases the thermal constraint and when the air humidity is high, evaporation of sweat is compromise. Thus, thermal stress becomes uncompensable which increases the risk of cardiovascular collapse. Cold exposure induces physiological responses to maintain internal temperature by both limiting thermal losses and increasing metabolic heat production. Cold can induce accidental hypothermia and local frost-bites; moreover, it increases the risk of arrhythmia during exercise. Some guidelines (cardiovascular fitness, water and electrolyte intakes, protective clothing) are given for each extreme condition.

Coulomb-free and Coulomb-distorted recolliding quantum orbits in photoelectron holography

NASA Astrophysics Data System (ADS)

Maxwell, A. S.; Figueira de Morisson Faria, C.

2018-06-01

We perform a detailed analysis of the different types of orbits in the Coulomb quantum orbit strong-field approximation (CQSFA), ranging from direct to those undergoing hard collisions. We show that some of them exhibit clear counterparts in the standard formulations of the strong-field approximation for direct and rescattered above-threshold ionization, and show that the standard orbit classification commonly used in Coulomb-corrected models is over-simplified. We identify several types of rescattered orbits, such as those responsible for the low-energy structures reported in the literature, and determine the momentum regions in which they occur. We also find formerly overlooked interference patterns caused by backscattered Coulomb-corrected orbits and assess their effect on photoelectron angular distributions. These orbits improve the agreement of photoelectron angular distributions computed with the CQSFA with the outcome of ab initio methods for high energy phtotoelectrons perpendicular to the field polarization axis.

Thermoregulatory and Immune Responses During Cold Exposure: Effects of Repeated Cold Exposure and Acute Exercise

DTIC Science & Technology

2000-03-01

shivering thermogenesis and vasoconstriction) during cold exposure is unknown. Thus, a series of experiments were executed to determine if serial cold ...to cold exposure? The results of these studies suggest that 1) serial cold water blunts shivering leadmg™ower core temperatures, 2) thermoregulatory...fatigues (i.e., causes blunted shivering thermogenesis and vasoconstriction) during cold exposure is unknown. Thus, a series of experiments were

Teaching in a Cold Environment.

ERIC Educational Resources Information Center

Ewert, Alan

1979-01-01

Designed to help teachers deal with students in a cold environment, this article explains cold physiology and fundamental laws of heat; describes 14 common cold injuries and their current treatment; and lists a number of useful teaching techniques for cold environments. (SB)

Exercise in the Cold

PubMed Central

Fudge, Jessie

2016-01-01

Context: Hypothermia and frostbite injuries occur in cold weather activities and sporting events. Evidence Acquisition: A PubMed search was used to identify original research and review articles related to cold, frostbite, and hypothermia. Inclusion was based on their relevance to prevention and treatment of cold-related injuries in sports and outdoor activities. Dates of review articles were limited to those published after 2010. No date limit was set for the most recent consensus statements or original research. Study Design: Clinical review. Level of Evidence: Level 5. Results: Frostbite and hypothermia are well-documented entities with good prevention strategies and prehospital treatment recommendations that have changed very little with time. A layered approach to clothing is the best way to prevent injury and respond to weather changes. Each athlete, defined as a participant in a cold weather sport or activity, will respond to cold differently depending on anthropometric measurements and underlying medical risk factors. An understanding of wind-chill temperatures, wetness, and the weather forecast allows athletes and event coordinators to properly respond to changing weather conditions. At the first sign of a freezing cold injury, ensure warm, dry clothes and move to a protected environment. Conclusion: Cold injuries can be prevented, and cold weather activities are safe with proper education, preparation, and response to changing weather conditions or injury. PMID:26857732

Retrieving plasmonic near-field information: A quantum-mechanical model for streaking photoelectron spectroscopy of gold nanospheres

NASA Astrophysics Data System (ADS)

Li, Jianxiong; Saydanzad, Erfan; Thumm, Uwe

2016-11-01

Streaked photoemission from nanostructures is characterized by size- and material-dependent nanometer-scale variations of the induced nanoplasmonic response to the electronic field of the streaking pulse and thus holds promise of allowing photoelectron imaging with both subfemtosecond temporal and nanometer spatial resolution. In order to scrutinize the driven collective electronic dynamics in 10-200-nm-diameter gold nanospheres, we calculated the plasmonic field induced by streaking pulses in the infrared and visible spectral range and developed a quantum-mechanical model for streaked photoemission by extreme ultraviolet pulses. Our simulated photoelectron spectra reveal a significant amplitude enhancement and phase shift of the photoelectron streaking trace relative to calculations that exclude the induced plasmonic field. Both are most pronounced for streaking pulses tuned to the plasmon frequency and retrace the plasmonic electromagnetic field enhancement and phase shift near the nanosphere surface.

Cold adaptation increases rates of nutrient flow and metabolic plasticity during cold exposure in Drosophila melanogaster

PubMed Central

McCue, Marshall D.; Sunny, Nishanth E.; Szejner-Sigal, Andre; Morgan, Theodore J.; Allison, David B.; Hahn, Daniel A.

2016-01-01

Metabolic flexibility is an important component of adaptation to stressful environments, including thermal stress and latitudinal adaptation. A long history of population genetic studies suggest that selection on core metabolic enzymes may shape life histories by altering metabolic flux. However, the direct relationship between selection on thermal stress hardiness and metabolic flux has not previously been tested. We investigated flexibility of nutrient catabolism during cold stress in Drosophila melanogaster artificially selected for fast or slow recovery from chill coma (i.e. cold-hardy or -susceptible), specifically testing the hypothesis that stress adaptation increases metabolic turnover. Using 13C-labelled glucose, we first showed that cold-hardy flies more rapidly incorporate ingested carbon into amino acids and newly synthesized glucose, permitting rapid synthesis of proline, a compound shown elsewhere to improve survival of cold stress. Second, using glucose and leucine tracers we showed that cold-hardy flies had higher oxidation rates than cold-susceptible flies before cold exposure, similar oxidation rates during cold exposure, and returned to higher oxidation rates during recovery. Additionally, cold-hardy flies transferred compounds among body pools more rapidly during cold exposure and recovery. Increased metabolic turnover may allow cold-adapted flies to better prepare for, resist and repair/tolerate cold damage. This work illustrates for the first time differences in nutrient fluxes associated with cold adaptation, suggesting that metabolic costs associated with cold hardiness could invoke resource-based trade-offs that shape life histories. PMID:27605506

Synchrotron-based ambient pressure X-ray photoelectron spectroscopy of hydrogen and helium

NASA Astrophysics Data System (ADS)

Zhong, Jian-Qiang; Wang, Mengen; Hoffmann, William H.; van Spronsen, Matthijs A.; Lu, Deyu; Boscoboinik, J. Anibal

2018-02-01

Contrary to popular belief, it is possible to obtain X-ray photoelectron spectra for elements lighter than lithium, namely hydrogen and helium. The literature is plagued with claims of this impossibility, which holds true for lab-based X-ray sources. However, this limitation is merely technical and is related mostly to the low X-ray photoionization cross-sections of the 1s orbitals of hydrogen and helium. In this letter, we show that, using ambient pressure X-ray photoelectron spectroscopy (XPS), a bright-enough X-ray source allows the study of these elusive elements. This has important implications in the understanding of the limitations of one of the most useful techniques in materials science, and moreover, it potentially opens the possibility of using XPS to directly study the most abundant element in the universe.

Cold thermal injury from cold caps used for the prevention of chemotherapy-induced alopecia.

PubMed

Belum, Viswanath Reddy; de Barros Silva, Giselle; Laloni, Mariana Tosello; Ciccolini, Kathryn; Goldfarb, Shari B; Norton, Larry; Sklarin, Nancy T; Lacouture, Mario E

2016-06-01

The use of scalp cooling for the prevention of chemotherapy-induced alopecia (CIA) is increasing. Cold caps are placed onto the hair-bearing areas of the scalp for varying time periods before, during, and after cytotoxic chemotherapy. Although not yet reported, improper application procedures could result in adverse events (AEs). At present, there are no evidence-based scalp cooling protocols, and there is no regulatory oversight of their use. To report the occurrence of cold thermal injury (frostbite) on the scalp, following the use of cold caps for the prevention of CIA. We identified four patients who developed cold thermal injuries on the scalp following the application of cold caps. Medical records were analyzed to retrieve the demographic and clinical characteristics. The cold thermal injuries in our patients were grade 1/2 in severity and improved with topical interventions and interruption of cold cap use, although grade 1 persistent alopecia ensued in 3 patients. The true incidence of such injuries in this setting, however, remains unknown. Cold thermal injuries are likely infrequent and preventable AEs that may result from improper device application procedures during cold cap use. Although these untoward events are usually mild to moderate in severity, the potential occurrence of long-term sequelae (e.g., permanent alopecia and scarring) or the need to discontinue cold cap use, are not known. Prospective studies are needed to further elucidate the risk and standardize healthcare delivery methods, and to improve patient/supportive/healthcare provider education.

Cold Shock as a Screen for Genes Involved in Cold Acclimatization in Neurospora crassa

PubMed Central

Watters, Michael K.; Manzanilla, Victor; Howell, Holly; Mehreteab, Alexander; Rose, Erik; Walters, Nicole; Seitz, Nicholas; Nava, Jacob; Kekelik, Sienna; Knuth, Laura; Scivinsky, Brianna

2018-01-01

When subjected to rapid drops of temperature (cold shock), Neurospora responds with a temporary shift in its morphology. This report is the first to examine this response genetically. We report here the results of a screen of selected mutants from the Neurospora knockout library for alterations in their morphological response to cold shock. Three groups of knockouts were selected to be subject to this screen: genes previously suspected to be involved in hyphal development as well as knockouts resulting in morphological changes; transcription factors; and genes homologous to E. coli genes known to alter their expression in response to cold shock. A total of 344 knockout strains were subjected to cold shock. Of those, 118 strains were identified with altered responses. We report here the cold shock morphologies and GO categorizations of strains subjected to this screen. Of strains with knockouts in genes associated with hyphal growth or morphology, 33 of 131 tested (25%) showed an altered response to cold shock. Of strains with knockouts in transcription factor genes, 30 of 145 (20%) showed an altered response to cold shock. Of strains with knockouts in genes homologous to E. coli genes which display altered levels of transcription in response to cold shock, a total of 55 of 68 tested (81%) showed an altered cold shock response. This suggests that the response to cold shock in these two organisms is largely shared in common. PMID:29563189

A transportable cold atom inertial sensor for space applications

NASA Astrophysics Data System (ADS)

Ménoret, V.; Geiger, R.; Stern, G.; Cheinet, P.; Battelier, B.; Zahzam, N.; Pereira Dos Santos, F.; Bresson, A.; Landragin, A.; Bouyer, P.

2017-11-01

Atom interferometry has hugely benefitted from advances made in cold atom physics over the past twenty years, and ultra-precise quantum sensors are now available for a wide range of applications [1]. In particular, cold atom interferometers have shown excellent performances in the field of acceleration and rotation measurements [2,3], and are foreseen as promising candidates for navigation, geophysics, geo-prospecting and tests of fundamental physics such as the Universality of Free Fall (UFF). In order to carry out a test of the UFF with atoms as test masses, one needs to compare precisely the accelerations of two atoms with different masses as they fall in the Earth's gravitational field. The sensitivity of atom interferometers scales like the square of the time during which the atoms are in free fall, and on ground this interrogation time is limited by the size of the experimental setup to a fraction of a second. Sending an atom interferometer in space would allow for several seconds of excellent free-fall conditions, and tests of the UFF could be carried out with precisions as low as 10-15 [4]. However, cold atoms experiments rely on complex laser systems, which are needed to cool down and manipulate the atoms, and these systems are usually very sensitive to temperature fluctuations and vibrations. In addition, when operating an inertial sensor, vibrations are a major issue, as they deteriorate the performances of the instrument. This is why cold atom interferometers are usually used in ground based facilities, which provide stable enough environments. In order to carry out airborne or space-borne measurements, one has to design an instrument which is both compact and stable, and such that vibrations induced by the platform will not deteriorate the sensitivity of the sensor. We report on the operation of an atom interferometer on board a plane carrying out parabolic flights (Airbus A300 Zero-G, operated by Novespace). We have constructed a compact and stable

Angle Resolved Photoelectron and Auger Electron Diffraction as a Structural Probe for Surfaces, Interfaces, and Epitaxial Films.

NASA Astrophysics Data System (ADS)

Li, Hong

The recently developed techniques of angle-resolved photoelectron and Auger electron diffraction (ARXPD/AED) have shown promise in identifying the structures of epitaxial films. This is due to the realization that electrons scattered by other atoms are enhanced along the forward direction. In this dissertation research, we have further investigated the capabilities of the ARXPD/AED technique. First, the complete polar angle distribution of the Auger electron intensity from Cu(001) was measured from the (100) to the (110) azimuth. The presentation of the ARAED in the form of a contour map clearly shows the relationship of the constructive and destructive interference of electron scattering to the crystallographic index of the crystal. Secondly, the angular distributions of electron emissions with initial states of 3p, 3d, 4d, and the Auger emission with electron kinetic energies ranging from 348 eV to 1477 eV were measured for single crystal Ag(001). The results show that all of these electron emissions have similar electron forward scattering enhancements along the directions of nearest and next nearest neighbour atoms in the crystal. The forward scattering enhancements do not shift as the electron kinectic energy changes. The ARXPD/AED combined with low energy electron diffraction (LEED) has been demonstrated to be a very powerful technique in probing both the long range order and the short range order of the epitaxial films. The epitaxial films studied include Co on Cu(001), Fe on Ag(001), Co on Ag(001), and Co on an ultra-thin film of Fe(001), which was epitaxially grown on Ag(001). We find that up to 20 ML thickness of high quality metastable fcc Co can be stabilized on Cu(001) at room temperature. We have directly verified that the Fe on Ag(001) is bcc. The Co on Ag(001) is neither bcc nor fcc for coverages of less than 3 ML. Thick films of Co on Ag(001) are disordered, of which a very small portion has a local structure of bcc. The bcc Co phases has been

Characterisation of baroreflex sensitivity of recreational ultra-endurance athletes.

PubMed

Foulds, Heather J A; Cote, Anita T; Phillips, Aaron A; Charlesworth, Sarah A; Bredin, Shannon S D; Burr, Jamie F; Drury, Chipman Taylor; Ngai, Shirley; Fougere, Renee J; Ivey, Adam C; Warburton, Darren E R

2014-01-01

Altered autonomic function has been identified following ultra-endurance event participation among elite world-class athletes. Despite dramatic increases in recreational athlete participation in these ultra-endurance events, the physiological effects on these athletes are less known. This investigation sought to characterise changes in surrogate measures of autonomic function: heart rate variability (HRV), blood pressure variability (BPV) and baroreceptor sensitivity (BRS) following ultra-endurance race participation. Further, we sought to compare baseline measures among ultra-endurance athletes and recreationally active controls not participating in the ultra-endurance race. Recreational ultra-endurance athletes (n = 25, 44.6 ± 8.2 years, 8 females) and recreationally active age, sex and body mass index matched controls (n = 25) were evaluated. Measurements of HRV, BPV and BRS were collected pre- and post-race for recreational ultra-endurance athletes and at baseline, for recreationally active controls. Post-race, ultra-endurance athletes demonstrated significantly greater sympathetic modulation [low frequency (LF) power HRV: 50.3 ± 21.6 normalised units (n.u.) to 65.9 ± 20.4 n.u., p = 0.01] and significantly lower parasympathetic modulation [high frequency (HF) power HRV: 45.0 ± 22.4 n.u. to 23.9 ± 13.1 n.u., p < 0.001] and BRS. Baseline measurements BRS (spectral: 13.96 ± 10.82 ms·mmHg(-1) vs. 11.39 ± 5.33 ms·mmHg(-1)) were similar among recreational ultra-endurance athletes and recreationally active controls, though recreational ultra-endurance athletes demonstrated greater parasympathetic modulation of some HRV and BPV measures. Recreational ultra-endurance athletes experienced increased sympathetic tone and declines in BRS post-race, similar to previously reported elite world-class ultra-endurance athletes, though still within normal population ranges.

Cold urticaria: inhibition of cold-induced histamine release by doxantrazole.

PubMed

Bentley-Phillips, C B; Eady, R A; Greaves, M W

1978-10-01

Thirteen patients with cold urticaria were studied to assess the effect of the systemic drug doxantrazole, which has actions resembling disodium cromoglycate, on cold evoked histamine release. The patients, all of whom developed an immediate local whealing response after cooling of the forearm, demonstrated release of histamine into venous blood draining that forearm. Following doxantrazole treatment, significant suppression of histamine release occurred. In some but not all patients this was accompanied by diminution of urtication in response to cooling. A double-blind study was carried out in 3 subjects, all of whom showed diminished cold-stimulated histamine release after doxantrazole. Two of these showed clinical improvement. Doxantrazole had no effect on erythema due to intradermal histamine, but did suppress the erythematous reaction to intradermal injection of compound 48/80. Our results suggest that doxantrazole or related anti-allergic agents might be useful in the treatment of cold urticaria.

Cold-induced ependymin expression in zebrafish and carp brain: implications for cold acclimation.

PubMed

Tang, S J; Sun, K H; Sun, G H; Lin, G; Lin, W W; Chuang, M J

1999-10-01

Cold acclimation has been suggested to be mediated by alternations in the gene expression pattern in the cold-adapted fish. To investigate the mechanism of cold acclimation in fish brain at the molecular level, relevant subsets of differentially expressed genes of interest were identified and cloned by the PCR-based subtraction suppression hybridization. Characterization of the selected cold-induced cDNA clones revealed one encoding ependymin. This gene was shown to be brain-specific. The expression of ependymin was induced by a temperature shift from 25 degrees C to 6 degrees C in Cyprinus carpio or 12 degrees C in Danio rerio. Activation of ependymin was detected 2 h after cold exposure and peaked at more than 10-fold at 12 h. This peak level remains unchanged until the temperature returns to 25 degrees C. Although the amount of soluble ependymin protein in brain was not changed by cold treatment, its level in the fibrous insoluble polymers increased 2-fold after exposure to low temperature. These findings indicate that the increase in ependymin expression is an early event that may play an important role in the cold acclimation of fish.

77 FR 43117 - Meeting of the Cold War Advisory Committee for the Cold War Theme Study

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-23

... the Cold War Advisory Committee for the Cold War Theme Study AGENCY: National Park Service, Interior... Committee Act, 5 U.S.C. Appendix, that the Cold War Advisory Committee for the Cold War Theme Study will... National Park Service (NPS) concerning the Cold War Theme Study. DATES: The teleconference meeting will be...

Repeatability of a cold stress test to assess cold sensitization.

PubMed

House, C M; Taylor, R J; Oakley, E H N

2015-10-01

Non-freezing cold injury (NFCI) is a syndrome in which damage to peripheral tissues occurs without the tissues freezing following exposure to low ambient temperatures. To assess the test-retest reliability of a cold stress test (CST) used to assess cold sensitization. Volunteers with no self-reported history of NFCI undertook the CST on three occasions. Thermal images were taken of the foot and hand before, immediately after and 5min after immersion of the limb in cold water for 2min. Cold sensitization was graded by the two clinicians and the lead author. Spot temperatures from the toe and finger pads were recorded. There were 30 white and 19 black male participants. The ratings indicated substantial agreement [a Cohen's kappa (κ) value of 0.61-0.8] to within ± one grading category for the hands and feet of the white volunteers and the hands of the black volunteers. Limits of agreement (LoA) analysis for toe and finger pad temperatures indicated high agreement (absolute 95% LoA < 5.5°C). Test-retest reliability for the feet of the black volunteers was not supported by the gradings (κ = 0.38) and toe pad temperatures (absolute 95% LoA = 9.5°C and coefficient of variation = 11%). The test-retest reliability of the CST is considered adequate for the assessment of the cold sensitization of the hands and feet of white and the hands of black healthy non-patients. The study should be repeated with patients who have suffered a NFCI. © Crown copyright 2015.

Direct Visualization of Valence Electron Motion Using Strong-Field Photoelectron Holography

NASA Astrophysics Data System (ADS)

He, Mingrui; Li, Yang; Zhou, Yueming; Li, Min; Cao, Wei; Lu, Peixiang

2018-03-01

Watching the valence electron move in molecules on its intrinsic timescale has been one of the central goals of attosecond science and it requires measurements with subatomic spatial and attosecond temporal resolutions. The time-resolved photoelectron holography in strong-field tunneling ionization holds the promise to access this realm. However, it remains to be a challenging task hitherto. Here we reveal how the information of valence electron motion is encoded in the hologram of the photoelectron momentum distribution (PEMD) and develop a novel approach of retrieval. As a demonstration, applying it to the PEMDs obtained by solving the time-dependent Schrödinger equation for the prototypical molecule H2+ , the attosecond charge migration is directly visualized with picometer spatial and attosecond temporal resolutions. Our method represents a general approach for monitoring attosecond charge migration in more complex polyatomic and biological molecules, which is one of the central tasks in the newly emerging attosecond chemistry.

Direct Visualization of Valence Electron Motion Using Strong-Field Photoelectron Holography.

PubMed

He, Mingrui; Li, Yang; Zhou, Yueming; Li, Min; Cao, Wei; Lu, Peixiang

2018-03-30

Watching the valence electron move in molecules on its intrinsic timescale has been one of the central goals of attosecond science and it requires measurements with subatomic spatial and attosecond temporal resolutions. The time-resolved photoelectron holography in strong-field tunneling ionization holds the promise to access this realm. However, it remains to be a challenging task hitherto. Here we reveal how the information of valence electron motion is encoded in the hologram of the photoelectron momentum distribution (PEMD) and develop a novel approach of retrieval. As a demonstration, applying it to the PEMDs obtained by solving the time-dependent Schrödinger equation for the prototypical molecule H_{2}^{+}, the attosecond charge migration is directly visualized with picometer spatial and attosecond temporal resolutions. Our method represents a general approach for monitoring attosecond charge migration in more complex polyatomic and biological molecules, which is one of the central tasks in the newly emerging attosecond chemistry.

Above-threshold ionization of noble gases in elliptically polarized fields: Effects of atomic polarization on photoelectron angular distributions

NASA Astrophysics Data System (ADS)

Wang, YanLan; Yu, ShaoGang; Lai, XuanYang; Liu, XiaoJun; Chen, Jing

2017-06-01

We theoretically investigate the atomic polarization effect on photoelectron angular distributions (PADs) in above-threshold ionization of noble gases with elliptically polarized laser fields at wavelength of 800 nm, ellipticity of 0.25, and intensity of 1.5 ×1014W/cm2 . Simulations based on a semiclassical model that includes both the ionic Coulomb potential and the atomic polarization effect show surprisingly little difference between PADs for Ar, Kr, and Xe, which is in good agreement with recent experimental observations. Our calculations reveal that the atomic polarization effect increases the distance of the tunnel exit point of the photoelectron to the parent ion and weakens the strength of the interaction between the parent ion and the photoelectron on its subsequent classical propagation. As a result, the forward-scattering electrons which contribute to the main lobes in PADs are substantially suppressed. Our results indicate that the insensitivity of PADs for Ar, Kr, and Xe may be closely related to the influence of the atomic polarization effect on the photoelectron dynamics in the strong laser field.

Distinguishability of N Composition Profiles In SiON Films On Si By Angle-Resolved X-ray Photoelectron Spectroscopy

NASA Astrophysics Data System (ADS)

Powell, C. J.; Werner, W. S. M.; Smekal, W.

2007-09-01

We report on the use of the NIST Database for the Simulation of Electron Spectra for Surface Analysis (SESSA) to determine N 1s, O 1s, and Si 2p3/2 photoelectron intensities for a 25 Å SiON film on a Si substrate with different distributions of N in the film. These simulations were made to assess the distinguishability of angle-resolved x-ray photoelectron spectroscopy (ARXPS) signals for each N distribution. Our approach differs from conventional simulations of ARXPS data in that we do not neglect elastic scattering of the photoelectrons and the finite solid angle of the analyzer. Appreciable dispersion of the photoelectron intensities was found only for the N 1s intensities at an emission angle of 75° (with respect to the surface normal). Conventional analyses of ARXPS data that include such large emission angles are unlikely to be valid due to angle-dependent changes of the attenuation length. We demonstrate the magnitude of elastic-scattering and analyzer solid-angle effects on the calculated angular distributions.

Electronic Equipment Cold Plates

DTIC Science & Technology

1976-04-01

using fans or blowers to force the air through the cooling device». ^J^lJ^^i 5!°^ it ia ’«"^"o^ve. nonto«ic. nonfla—able, *nd possesses good ...Techniques GENERAL THERMAL CONTROL SYSTEMS AND THEIR REgUIREMENTS FLON DISTRIBUTION IN MANIFOLDS THE COLD PLATE IA ,! 1 3 S 12 15 33 32 32... IA .1 132 132 132 155 169 179 183 r (1) Air-Cooled Cold Plate No. (2) Air-Cooled Cold Plate No. (3) Air-cooled Cold Plate No. (4) Air-Cooled

Teaching in a Cold Environment.

ERIC Educational Resources Information Center

Ewert, Alan

Instructors who teach outdoors in an environment so cold as to cause injury must satisfy program objectives while avoiding cold injury to themselves and students, help students focus on learning instead of discomfort, and alleviate some students' intense fear of the cold. Dealing with the cold successfully requires a thorough knowledge of:…

7 CFR 58.144 - Pasteurization or ultra-pasteurization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Pasteurization or ultra-pasteurization. 58.144 Section... Service 1 Operations and Operating Procedures § 58.144 Pasteurization or ultra-pasteurization. When pasteurization or ultra-pasteurization is intended or required, or when a product is designated “pasteurized” or...

Rocket measurements of conjugate photoelectrons during the total solar eclipse of 7 March 1970 over Wallops Island.

NASA Technical Reports Server (NTRS)

Maier, E. J.; Narasinga Rao, B. C.

1972-01-01

Results of measurements made with a retarding potential analyzer on a Nike-Tomahawk rocket during the totality of the solar eclipse, showing definite evidence for the existence of photoelectrons from the conjugate hemisphere. Photoelectrons are observed in the altitude range from 120 to 260 km. The observed flux in the energy range from 2 to 30 eV is relatively constant above about 200 km, but decreased below that altitude. The flux of 5-eV energy electrons above 200 km altitude is about 10 to the 7th power electrons/cm/sec/eV. Higher-energy electrons were also observed, and it is possible that the energy content of these observed fluxes of conjugate-point photoelectrons is sufficient to maintain the observed electron densities and temperatures during the total eclipse.

Emission Depth Distribution Function of Al 2s Photoelectrons in Al2O3

NASA Astrophysics Data System (ADS)

Hucek, S.; Zemek, J.; Jablonski, A.; Tilinin, I. S.

The escape probability of Al 2s photoelectrons leaving an aluminum oxide sample (Al2O3) has been studied as a function of depth of origin. It has been found that the escape probability (the so-called emission depth distribution function - DDF) depends strongly on the photoelectron emission direction with respect to that of the incident X-ray beam. In particular, in the emission direction close to that of photon propagation, the DDF differs substantially from the simple Beer-Lambert law and exhibits a nonmonotonic behavior with a maximum in the near-surface region at a depth of about 10 Å. Experimental results are in good agreement with theoretical predictions based on Monte Carlo simulations of the electron transport and with analytical solution of the linearized Boltzmann kinetic equation with appropriate boundary conditions. Both theoretical approaches take into account multiple elastic scattering of photoelectrons on their way out of the sample. It is shown that the commonly used straight line approximation (SLA), which neglects elastic scattering effects, fails to describe adequately experimental data at emission directions close to minima of the differential photoelectric cross section.

Cold Temperatures Increase Cold Hardiness in the Next Generation Ophraella communa Beetles

PubMed Central

Zhou, Zhong-Shi; Rasmann, Sergio; Li, Min; Guo, Jian-Ying; Chen, Hong-Song; Wan, Fang-Hao

2013-01-01

The leaf beetle, Ophraella communa, has been introduced to control the spread of the common ragweed, Ambrosia artemisiifolia, in China. We hypothesized that the beetle, to be able to track host-range expansion into colder climates, can phenotypically adapt to cold temperatures across generations. Therefore, we questioned whether parental experience of colder temperatures increases cold tolerance of the progeny. Specifically, we studied the demography, including development, fecundity, and survival, as well as physiological traits, including supercooling point (SCP), water content, and glycerol content of O. communa progeny whose parents were maintained at different temperature regimes. Overall, the entire immature stage decreased survival of about 0.2%–4.2% when parents experienced cold temperatures compared to control individuals obtained from parents raised at room temperature. However, intrinsic capacity for increase (r), net reproductive rate (R 0) and finite rate of increase (λ) of progeny O. communa were maximum when parents experienced cold temperatures. Glycerol contents of both female and male in progeny was significantly higher when maternal and paternal adults were cold acclimated as compared to other treatments. This resulted in the supercooling point of the progeny adults being significantly lower compared to beetles emerging from parents that experienced room temperatures. These results suggest that cold hardiness of O. communa can be promoted by cold acclimation in previous generation, and it might counter-balance reduced survival in the next generation, especially when insects are tracking their host-plants into colder climates. PMID:24098666

Synchrotron-based ambient pressure X-ray photoelectron spectroscopy of hydrogen and helium

DOE PAGES

Zhong, Jian-Qiang; Wang, Mengen; Hoffmann, William H.; ...

2018-03-01

Contrary to popular belief, it is possible to obtain X-ray photoelectron spectra for elements lighter than lithium, namely hydrogen and helium. The literature is plagued with claims of this impossibility, which holds true for lab-based X-ray sources. However, this limitation is merely technical and is related mostly to the low X-ray photoionization cross-sections of the 1s orbitals of hydrogen and helium. Here, we show that, using ambient pressure X-ray photoelectron spectroscopy (XPS), a bright-enough X-ray source allows the study of these elusive elements. This has important implications in the understanding of the limitations of one of the most useful techniquesmore » in materials science, and moreover, it potentially opens the possibility of using XPS to directly study the most abundant element in the universe.« less

Synchrotron-based ambient pressure X-ray photoelectron spectroscopy of hydrogen and helium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Jian-Qiang; Wang, Mengen; Hoffmann, William H.

Contrary to popular belief, it is possible to obtain X-ray photoelectron spectra for elements lighter than lithium, namely hydrogen and helium. The literature is plagued with claims of this impossibility, which holds true for lab-based X-ray sources. However, this limitation is merely technical and is related mostly to the low X-ray photoionization cross-sections of the 1s orbitals of hydrogen and helium. Here, we show that, using ambient pressure X-ray photoelectron spectroscopy (XPS), a bright-enough X-ray source allows the study of these elusive elements. This has important implications in the understanding of the limitations of one of the most useful techniquesmore » in materials science, and moreover, it potentially opens the possibility of using XPS to directly study the most abundant element in the universe.« less

Photoelectron escape fluxes over the equatorial and midlatitude regions

NASA Technical Reports Server (NTRS)

Narasingarao, B. C.; Singh, R. N.; Maier, E. J.

1972-01-01

Satellite measurements of photoelectron escape flux around noontime made by Explorer 31 in 600-800 km altitude range are reported for the equatorial and midlatitude regions. The pitch angle distributions and the spectral distributions are derived from the data. Analyzed data show that the flux for equatorial regions is lower by a factor 2 to 3 in comparison to that of midlatitude regions. Theoretical calculations are also made to compare with observed escape fluxes.

X-ray mirror prototype based on cold shaping of thin glass foils

NASA Astrophysics Data System (ADS)

Basso, Stefano; Civitani, Marta; Ghigo, Mauro; Hołyszko, Joanna; Pareschi, Giovanni; Salmaso, Bianca; Vecchi, Gabriele; Burwitz, Vadim; Pelliciari, Carlo; Hartner, Gisela D.; Breunig, Elias

2017-08-01

The Slumping Glass Optics technology for the fabrication of astronomical X-ray mirrors has been developed in recent years in USA and Europe. The process has been used for making the mirrors of the Nustar, mission. The process starts with very thin glass foils hot formed to copy the profile of replication moulds. At INAF - Osservatorio Astronomico di Brera a process based on cold shaping is being developed, based on an integration method involving the use of interconnecting ribs for making stacks. Each glass foil in the stack is shaped onto a very precise integration mould and the correct shape is frozen by means of glued ribs that act as spacers between one layer and the next one (the first layers being attached to a thick substrate). Therefore, the increasing availability of flexible glass foils with a thickness of a few tens of microns (driven by electronic market for ultra-thin displays) opens new possibilities for the fabrication of X-ray mirrors. This solution appears interesting especially for the fabrication of mirrors for hard X-rays (with energy > 10 keV) based on multilayer coatings, taking advantage from the intrinsic low roughness of the glass foils that should grant a low scattering level. The stress frozen on the glass due to the cold shaping is not negligible, but it is kept into account in the errors of the X-ray optics design. As an exercise, we have considered the requirements and specs of the FORCE hard Xray mission concept (being studied by JAXA) and we have designed the mirror modules assuming the cold slumping as a fabrication method. In the meantime, a prototype (representative of the FORCE mirror modules) is being design and integrated in order to demonstrate the feasibility and the capacity to reach good angular resolution.

On some limitations on temporal resolution in imaging subpicosecond photoelectronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shchelev, M Ya; Andreev, S V; Degtyareva, V P

2015-05-31

Numerical modelling is used to analyse some effects restricting the enhancement of temporal resolution into the area better than 100 fs in streak image tubes and photoelectron guns. A particular attention is paid to broadening of an electron bunch as a result of Coulomb interaction. Possible ways to overcome the limitations under consideration are discussed. (extreme light fields and their applications)

Photoelectron spectra and biological activity of cinnamic acid derivatives revisited

NASA Astrophysics Data System (ADS)

Novak, Igor; Klasinc, Leo; McGlynn, Sean P.

2018-01-01

The electronic structures of several derivatives of cinnamic acid have been studied by UV photoelectron spectroscopy (UPS) and Green's function quantum chemical calculations. The spectra reveal the presence of dimers in the gas phase for p-coumaric and ferulic acids. The electronic structure analysis has been related to the biological properties of these compounds through the analysis of some structure-activity relationships (SAR).

Primary acquired cold urticaria.

PubMed

Lee, Chyh-Woei; Sheffer, Albert L

2003-01-01

Primary acquired cold urticaria (ACU) is the most common type of cold urticaria characterized by rapid onset of pruritic hives, swelling, and possible severe systemic reactions including hypotension and shock after cold exposure. Primary ACU is diagnosed by history of such symptoms, a positive immediate cold-contact stimulation test, and negative laboratory evaluation for underlying systemic disorders. Clinicians should be aware that patients with ACU may be susceptible to life-threatening systemic reactions especially during aquatic activities and that proper patient education is extremely important. This article reviews the clinical presentation, pathogenesis, diagnosis, and management of primary ACU.

Ultra-wide-field imaging in diabetic retinopathy; an overview.

PubMed

Ghasemi Falavarjani, Khalil; Wang, Kang; Khadamy, Joobin; Sadda, Srinivas R

2016-06-01

To present an overview on ultra-wide-field imaging in diabetic retinopathy. A comprehensive search of the pubmed database was performed using the search terms of "ultra-wide-field imaging", "ultra-wide-field fluorescein angiography" and "diabetic retinopathy". The relevant original articles were reviewed. New advances in ultra-wide-field imaging allow for precise measurements of the peripheral retinal lesions. A consistent finding amongst these articles was that ultra-wide-field imaging improved detection of peripheral lesion. There was discordance among the studies, however, on the correlation between peripheral diabetic lesions and diabetic macular edema. Visualization of the peripheral retina using ultra-wide-field imaging improves diagnosis and classification of diabetic retinopathy. Additional studies are needed to better define the association of peripheral diabetic lesions with diabetic macular edema.

Anion Photoelectron Spectroscopic Studies of NbCr(CO)_n- (n = 2,3) Heterobimetallic Carbonyl Complexes

NASA Astrophysics Data System (ADS)

Baudhuin, Melissa A.; Boopalachandran, Praveenkumar; Leopold, Doreen

2015-06-01

Anion photoelectron spectra and density functional calculations are reported for NbCr(CO)2- and NbCr(CO)3- complexes prepared by addition of Cr(CO)6 vapor to a flow tube equipped with a niobium cathode discharge source. Electron affinities (± 0.007 eV) are measured to be 1.668 eV for NbCr(CO)2 and 1.162 eV for NbCr(CO)3, values which exceed the 0.793 eV electron affinity previously measured for ligand-free NbCr. The vibrationally-resolved 488 nm photoelectron spectra are compared with Franck-Condon spectra predicted for various possible isomers and spin states of the anionic and neutral metal carbonyl complexes. Results are also compared with photoelectron spectra of the corresponding chromium carbonyl complexes and of NbCr and NbCr-, which have formal bond orders of 5.5 (2Δ) and 6 (1σ+), respectively. These comparisons help to elucidate the effects of sequential carbonylation on this multiple metal-metal bond, and of the formation of this bond on the chromium-carbonyl interactions.

Heat strain in cold.

PubMed

Rintamäki, Hannu; Rissanen, Sirkka

2006-07-01

In spite of increased environmental cold stress, heat strain is possible also in a cold environment. The body heat balance depends on three factors: environmental thermal conditions, metabolic heat production and thermal insulation of clothing and other protective garments. As physical exercise may increase metabolic heat production from rest values by ten times or even more, the required thermal insulation of clothing may vary accordingly. However, in most outdoor work, and often in indoor cold work, too, the thermal insulation of clothing is impractical, difficult or impossible to adjust according to the changes in physical activity. This is especially true with whole body covering garments like chemical protective clothing. As a result of this imbalance, heat strain may develop. In cold all the signs of heat strain (core temperature above 38 degrees C, warm or hot thermal sensations, increased cutaneous circulation and sweating) may not be present at the same time. Heat strain in cold may be whole body heat strain or related only to torso or core temperature. Together with heat strain in torso or body core, there can be at the same time even cold strain in peripheral parts and/or superficial layers of the body. In cold environment both the preservation of insulation and facilitation of heat loss are important. Development of clothing design is still needed to allow easy adjustments of thermal insulation.

Ultra-short ion and neutron pulse production

DOEpatents

Leung, Ka-Ngo; Barletta, William A.; Kwan, Joe W.

2006-01-10

An ion source has an extraction system configured to produce ultra-short ion pulses, i.e. pulses with pulse width of about 1 .mu.s or less, and a neutron source based on the ion source produces correspondingly ultra-short neutron pulses. To form a neutron source, a neutron generating target is positioned to receive an accelerated extracted ion beam from the ion source. To produce the ultra-short ion or neutron pulses, the apertures in the extraction system of the ion source are suitably sized to prevent ion leakage, the electrodes are suitably spaced, and the extraction voltage is controlled. The ion beam current leaving the source is regulated by applying ultra-short voltage pulses of a suitable voltage on the extraction electrode.

Effects of cold temperatures on the excitability of rat trigeminal ganglion neurons that are not for cold-sensing

PubMed Central

Kanda, Hirosato; Gu, Jianguo G.

2016-01-01

Except a small population of primary afferent neurons for sensing cold to generate the sensations of innocuous and noxious cold, it is generally believed that cold temperatures suppress the excitability of other primary afferent neurons that are not for cold-sensing. These not-for-cold-sensing neurons include the majority of non-nociceptive and nociceptive afferent neurons. In the present study we have found that not-for-cold-sensing neurons of rat trigeminal ganglia (TG) change their excitability in several ways at cooling temperatures. In nearly 70% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C increases their membrane excitability. We regard these neurons as cold-active neurons. For the remaining 30% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C either has no effect (regarded as cold-ineffective neurons) or suppress (regarded as cold-suppressive neurons) their membrane excitability. For cold-active neurons, the cold temperature of 15°C increases their excitability as is evidenced by the increases in action potential (AP) firing numbers and/or reduction of AP rheobase when these neurons are depolarized electrically. The cold temperature of 15°C significantly inhibits M-currents and increases membrane input resistance of cold-active neurons. Retigabine, an M-current activator, abolishes the effect of cold temperatures on AP firing but not the effect of cold temperature on AP rheobase levels. The inhibition of M-currents and the increases of membrane input resistance are likely two mechanisms by which cooling temperatures increase the excitability of not-for-cold-sensing TG neurons. PMID:26709732

Cold-Weather Sports

MedlinePlus

... Videos for Educators Search English Español Cold-Weather Sports KidsHealth / For Teens / Cold-Weather Sports What's in this article? What to Do? Classes ... weather. What better time to be outdoors? Winter sports can help you burn calories, increase your cardiovascular ...

Vibrationally induced inversion of photoelectron forward-backward asymmetry in chiral molecule photoionization by circularly polarized light

PubMed Central

Garcia, Gustavo A.; Nahon, Laurent; Daly, Steven; Powis, Ivan

2013-01-01

Electron–nuclei coupling accompanying excitation and relaxation processes is a fascinating phenomenon in molecular dynamics. A striking and unexpected example of such coupling is presented here in the context of photoelectron circular dichroism measurements on randomly oriented, chiral methyloxirane molecules, unaffected by any continuum resonance. Here, we report that the forward-backward asymmetry in the electron angular distribution, with respect to the photon axis, which is associated with photoelectron circular dichroism can surprisingly reverse direction according to the ion vibrational mode excited. This vibrational dependence represents a clear breakdown of the usual Franck–Condon assumption, ascribed to the enhanced sensitivity of photoelectron circular dichroism (compared with other observables like cross-sections or the conventional anisotropy parameter-β) to the scattering phase off the chiral molecular potential, inducing a dependence on the nuclear geometry sampled in the photoionization process. Important consequences for the interpretation of such dichroism measurements within analytical contexts are discussed. PMID:23828557

Cold Antimatter Plasmas, and Aspirations for Cold Antihydrogen

DTIC Science & Technology

2002-06-24

comparison of any baryon and antibaryon by almost a factor of CP606, Non-Neutral Plasma Physics IV, edited by F. Anderegg et al. © 2002 American...antiprotons 3 _one-electron .1 eV quantum cyclotron 0.001 K FIGURE 1. Particle energies a million. An improved baryon CPT test (e.g. involving cold...more precise tests of CPT invariance with baryons and leptons than have been realized so far. The pursuit of cold antihydrogen thus began some time ago

''Reading'' the photoelectron {beta}-parameter spectrum in a resonance region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolmatov, V. K.; Guler, E.; Manson, S. T.

2007-09-15

The behavior of the dipole photoelectron angular distribution parameter {beta}{sub nl}({omega}) in the vicinity of autoionizing resonances is discussed. It is shown that from this behavior, surprisingly, many photoionization parameters that cannot be measured experimentally can be extracted. These are the energy positions and ordering of autoionizing resonance minima in the partial photoionization cross sections {sigma}{sub l+1} and {sigma}{sub l-1}, the energies at which these two cross sections intersect, and signs and magnitudes of the cos({delta}{sub l+1}-{delta}{sub l-1}) ({delta}{sub l{+-}}{sub 1} being the phase shifts of the dipole photoionization amplitudes D{sub l{+-}}{sub 1}, respectively) through the autoionizing resonance energy region.more » Based on this, a deeper interpretation of such effects as the width-narrowing, width-fluctuating, and q-reversal in the {beta}{sub nl} parameter spectrum in the autoionizing resonance energy region is given. As an example, calculated data for partial photoionization cross sections {sigma}{sub 3d{r_reversible}}{sub f} and {sigma}{sub 3d{r_reversible}}{sub p}, and {beta}{sub 3d} parameters for 3d photoelectrons from Cr{sup +} are presented.« less

Graphene oxide windows for in situ environmental cell photoelectron spectroscopy.

PubMed

Kolmakov, Andrei; Dikin, Dmitriy A; Cote, Laura J; Huang, Jiaxing; Abyaneh, Majid Kazemian; Amati, Matteo; Gregoratti, Luca; Günther, Sebastian; Kiskinova, Maya

2011-08-28

The performance of new materials and devices often depends on processes taking place at the interface between an active solid element and the environment (such as air, water or other fluids). Understanding and controlling such interfacial processes require surface-specific spectroscopic information acquired under real-world operating conditions, which can be challenging because standard approaches such as X-ray photoelectron spectroscopy generally require high-vacuum conditions. The state-of-the-art approach to this problem relies on unique and expensive apparatus including electron analysers coupled with sophisticated differentially pumped lenses. Here, we develop a simple environmental cell with graphene oxide windows that are transparent to low-energy electrons (down to 400 eV), and demonstrate the feasibility of X-ray photoelectron spectroscopy measurements on model samples such as gold nanoparticles and aqueous salt solution placed on the back side of a window. These proof-of-principle results show the potential of using graphene oxide, graphene and other emerging ultrathin membrane windows for the fabrication of low-cost, single-use environmental cells compatible with commercial X-ray and Auger microprobes as well as scanning or transmission electron microscopes.

Photoelectron spectroscopy of a series of acetate and propionate esters

NASA Astrophysics Data System (ADS)

Śmiałek, Małgorzata A.; Guthmuller, Julien; MacDonald, Michael A.; Zuin, Lucia; Delwiche, Jacques; Hubin-Franskin, Marie-Jeanne; Lesniewski, Tadeusz; Mason, Nigel J.; Limão-Vieira, Paulo

2017-10-01

The electronic state and photoionization spectroscopy of a series of acetate esters: methyl acetate, isopropyl acetate, butyl acetate and pentyl acetate as well as two propionates: methyl propionate and ethyl propionate, have been determined using vacuum-ultraviolet photoelectron spectroscopy. These experimental investigations are complemented by ab initio calculations. The measured first adiabatic and vertical ionization energies were determined as: 10.21 and 10.45 eV for methyl acetate, 9.99 and 10.22 eV for isopropyl acetate, 10.07 and 10.26 eV for butyl acetate, 10.01 and 10.22 eV for pentyl acetate, 10.16 and 10.36 eV for methyl propionate and 9.99 and 10.18 eV for ethyl propionate. For the four smaller esters vibrational transitions were calculated and compared with those identified in the photoelectron spectrum, revealing the most distinctive ones to be a Csbnd O stretch combined with a Cdbnd O stretch. The ionization energies of methyl and ethyl esters as well as for a series of formates and acetates were compared showing a clear dependence of the value of the ionization energy on the size of the molecule with very little influence of its conformation.

Femtosecond Time-Resolved Photoelectron Imaging of Excited Doped Helium Nanodroplets

NASA Astrophysics Data System (ADS)

Saladrigas, Catherine; Bacellar, Camila; Leone, Stephen R.; Neumark, Daniel M.; Gessner, Oliver

2017-04-01

Helium nanodroplets are excellent matrices for high resolution spectroscopy and the study of ultracold chemistry. They are optically transparent. In their electronic ground state, interact very weakly with any atomic or molecular dopant. Electronically excited droplets, however, can strongly interact with dopants through a variety of relaxation mechanisms. Previously, these host-dopant interactions were studied in the energy domain, revealing Penning ionization processes enabled by energy transfer between the droplet host and atomic dopants. Using femtosecond time resolved XUV photoelectron imaging, we plan to perform complementary experiments in the time domain to gain deeper insight into the timescales of energy transfer processes and how they compete with internal droplet relaxation. First experiments will be performed using noble gas dopants, such as Kr and Ne, which will be compared to previous energy-domain studies. Femtosecond XUV pulses produced by high harmonic generation will be used to excite the droplets, IR and near-UV light will be used to monitor the relaxation dynamics. Using velocity map imaging, both photoelectron kinetic energies and angular distributions will be recorded as a function of time. Preliminary results and proposed experiments will be presented.

Comparative analysis of Hibiscus sabdariffa (roselle) hot and cold extracts in respect to their potential for α-glucosidase inhibition.

PubMed

Rasheed, Dalia M; Porzel, Andrea; Frolov, Andrei; El Seedi, Hesham R; Wessjohann, Ludger A; Farag, Mohamed A

2018-06-01

Roselle (Hibiscus sabdariffa) is a functional food with potential health benefits, consumed either as hot or cold beverage. To ensure quality control of its various products, accurate measurement of active metabolites is warranted. Herein, we propose a combination of ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) and nuclear magnetic resonance (NMR) analytical platforms for the untargeted characterization of metabolites in two roselle cultivars, Aswan and Sudan-1. The analyses revealed 33 metabolites, including sugars, flavonoids, anthocyanins, phenolic and aliphatic organic acids. Their relative contents in cultivars were assessed via principle component analysis (PCA) and orthogonal projection to latent structures analysis (OPLS). Impact of the different extraction methods (decoction, infusion and maceration) was compared by quantitative 1 H NMR spectroscopy, revealing cold maceration to be optimal for preserving anthocyanins, whereas infusion was more suited for recovering organic acids. The metabolite pattern revealed by the different extraction methods was found in good correlation for their ability to inhibit α-glucosidase enzyme. Copyright © 2018 Elsevier Ltd. All rights reserved.

Laser-produced lithium plasma as a narrow-band extended ultraviolet radiation source for photoelectron spectroscopy.

PubMed

Schriever, G; Mager, S; Naweed, A; Engel, A; Bergmann, K; Lebert, R

1998-03-01

Extended ultraviolet (EUV) emission characteristics of a laser-produced lithium plasma are determined with regard to the requirements of x-ray photoelectron spectroscopy. The main features of interest are spectral distribution, photon flux, bandwidth, source size, and emission duration. Laser-produced lithium plasmas are characterized as emitters of intense narrow-band EUV radiation. It can be estimated that the lithium Lyman-alpha line emission in combination with an ellipsoidal silicon/molybdenum multilayer mirror is a suitable EUV source for an x-ray photoelectron spectroscopy microscope with a 50-meV energy resolution and a 10-mum lateral resolution.

Photoelectron linear accelerator for producing a low emittance polarized electron beam

DOEpatents

Yu, David U.; Clendenin, James E.; Kirby, Robert E.

2004-06-01

A photoelectron linear accelerator for producing a low emittance polarized electric beam. The accelerator includes a tube having an inner wall, the inner tube wall being coated by a getter material. A portable, or demountable, cathode plug is mounted within said tube, the surface of said cathode having a semiconductor material formed thereon.

Geodynamic environments of ultra-slow spreading

NASA Astrophysics Data System (ADS)

Kokhan, Andrey; Dubinin, Evgeny

2015-04-01

Ultra-slow spreading is clearly distinguished as an outstanding type of crustal accretion by recent studies. Spreading ridges with ultra-slow velocities of extension are studied rather well. But ultra-slow spreading is characteristic feature of not only spreading ridges, it can be observed also on convergent and transform plate boundaries. Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on divergent plate boundaries: 1. On spreading ridges with ultra-slow spreading, both modern (f.e. Gakkel, South-West Indian, Aden spreading center) and ceased (Labrador spreading center, Aegir ridge); 2. During transition from continental rifting to early stages of oceanic spreading (all spreading ridges during incipient stages of their formation); 3. During incipient stages of formation of spreading ridges on oceanic crust as a result of ridge jumps and reorganization of plate boundaries (f.e. Mathematicians rise and East Pacific rise); 4. During propagation of spreading ridge into the continental crust under influence of hotspot (Aden spreading center and Afar triple junction), under presence of strike-slip faults preceding propagation (possibly, rift zone of California Bay). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on transform plate boundaries: 1. In transit zones between two "typical" spreading ridges (f.e. Knipovich ridge); 2. In semi strike-slip/extension zones on the oceanic crust (f.e. American-Antarctic ridge); 3. In the zones of local extension in regional strike-slip areas in pull-apart basins along transform boundaries (Cayman trough, pull-apart basins of the southern border of Scotia plate). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on convergent plate boundaries: 1. During back-arc rifting on the stage of transition into back-arc spreading (central

Avionics Box Cold Plate Damage Prevention

NASA Technical Reports Server (NTRS)

Stambolian, Damon B.; Larchar, Steven W.; Henderson, Gena; Tran, Donald; Barth, Tim

2012-01-01

Problem Introduction: 1. Prevent Cold Plate Damage in Space Shuttle. 1a. The number of cold plate problems had increased from an average of 16.5 per/year between 1990 through 2000, to an average of 39.6 per year between 2001through 2005. 1b. Each complete set of 80 cold plates cost approximately $29 million, an average of $362,500 per cold plate. 1c It takes four months to produce a single cold plate. 2. Prevent Cold Plate Damage in Future Space Vehicles.

Cold acclimation and cognitive performance: A review.

PubMed

Jones, Douglas M; Bailey, Stephen P; Roelands, Bart; Buono, Michael J; Meeusen, Romain

2017-12-01

Athletes, occupational workers, and military personnel experience cold temperatures through cold air exposure or cold water immersion, both of which impair cognitive performance. Prior work has shown that neurophysiological pathways may be sensitive to the effects of temperature acclimation and, therefore, cold acclimation may be a potential strategy to attenuate cold-induced cognitive impairments for populations that are frequently exposed to cold environments. This review provides an overview of studies that examine repeated cold stress, cold acclimation, and measurements of cognitive performance to determine whether or not cold acclimation provides beneficial protection against cold-induced cognitive performance decrements. Studies included in this review assessed cognitive measures of reaction time, attention, logical reasoning, information processing, and memory. Repeated cold stress, with or without evidence of cold acclimation, appears to offer no added benefit of improving cognitive performance. However, research in this area is greatly lacking and, therefore, it is difficult to draw any definitive conclusions regarding the use of cold acclimation to improve cognitive performance during subsequent cold exposures. Given the current state of minimal knowledge on this topic, athletes, occupational workers, and military commands looking to specifically enhance cognitive performance in cold environments would likely not be advised to spend the time and effort required to become acclimated to cold. However, as more knowledge becomes available in this area, recommendations may change. Copyright © 2017 Elsevier B.V. All rights reserved.

Inter-diffusion of copper and hafnium as studied by x-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Pearson, Justin; Chourasia, A. R.

The Cu/Hf interface has been characterized by x-ray photoelectron spectroscopy. Thin films (thicknesses ranging from 100 nm to 150 nm) of hafnium were deposited on a silicon substrate. About 80 nm of copper was then deposited on such samples. The e-beam method was used for the deposition. The samples were annealed for 30 min at temperatures of 100, 200, 300, 400, and 500°C. The inter-diffusion of copper and hafnium was investigated by sequential sputter depth profiling and x-ray photoelectron spectroscopy. The interdiffusion in each case was analyzed by the Matano-Boltzmann's procedure using the Fick's second law. The interdiffusion coefficients and the width of the interface as determined from the data have been correlated with the annealing temperature. Supported by Organized Research, TAMU-Commerce.

Electron scattering in large water clusters from photoelectron imaging with high harmonic radiation.

PubMed

Gartmann, Thomas E; Hartweg, Sebastian; Ban, Loren; Chasovskikh, Egor; Yoder, Bruce L; Signorell, Ruth

2018-06-06

Low-energy electron scattering in water clusters (H2O)n with average cluster sizes of n < 700 is investigated by angle-resolved photoelectron spectroscopy using high harmonic radiation at photon energies of 14.0, 20.3, and 26.5 eV for ionization from the three outermost valence orbitals. The measurements probe the evolution of the photoelectron anisotropy parameter β as a function of cluster size. A remarkably steep decrease of β with increasing cluster size is observed, which for the largest clusters reaches liquid bulk values. Detailed electron scattering calculations reveal that neither gas nor condensed phase scattering can explain the cluster data. Qualitative agreement between experiment and simulations is obtained with scattering calculations that treat cluster scattering as an intermediate case between gas and condensed phase scattering.

Direct work function measurement by gas phase photoelectron spectroscopy and its application on PbS nanoparticles.

PubMed

Axnanda, Stephanus; Scheele, Marcus; Crumlin, Ethan; Mao, Baohua; Chang, Rui; Rani, Sana; Faiz, Mohamed; Wang, Suidong; Alivisatos, A Paul; Liu, Zhi

2013-01-01

Work function is a fundamental property of a material's surface. It is playing an ever more important role in engineering new energy materials and efficient energy devices, especially in the field of photovoltaic devices, catalysis, semiconductor heterojunctions, nanotechnology, and electrochemistry. Using ambient pressure X-ray photoelectron spectroscopy (APXPS), we have measured the binding energies of core level photoelectrons of Ar gas in the vicinity of several reference materials with known work functions (Au(111), Pt(111), graphite) and PbS nanoparticles. We demonstrate an unambiguously negative correlation between the work functions of reference samples and the binding energies of Ar 2p core level photoelectrons detected from the Ar gas near the sample surface region. Using this experimentally determined linear relationship between the surface work function and Ar gas core level photoelectron binding energy, we can measure the surface work function of different materials under different gas environments. To demonstrate the potential applications of this ambient pressure XPS technique in nanotechnology and solar energy research, we investigate the work functions of PbS nanoparticles with various capping ligands: methoxide, mercaptopropionic acid, and ethanedithiol. Significant Fermi level position changes are observed for PbS nanoparticles when the nanoparticle size and capping ligands are varied. The corresponding changes in the valence band maximum illustrate that an efficient quantum dot solar cell design has to take into account the electrochemical effect of the capping ligand as well.

Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces

NASA Astrophysics Data System (ADS)

Wilmsmeyer, Amanda R.; Gordon, Wesley O.; Davis, Erin Durke; Mantooth, Brent A.; Lalain, Teri A.; Morris, John R.

2014-01-01

A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry to study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.

Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces.

PubMed

Wilmsmeyer, Amanda R; Gordon, Wesley O; Davis, Erin Durke; Mantooth, Brent A; Lalain, Teri A; Morris, John R

2014-01-01

A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry to study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.

Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilmsmeyer, Amanda R.; Morris, John R.; Gordon, Wesley O.

2014-01-15

A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry tomore » study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.« less

Cold thermal injury from cold caps used for the prevention of chemotherapy-induced alopecia

PubMed Central

Belum, Viswanath Reddy; de Barros Silva, Giselle; Laloni, Mariana Tosello; Ciccolini, Kathryn; Sklarin, Nancy T.; Lacouture, Mario E.

2017-01-01

INTRODUCTION The use of scalp cooling for the prevention of chemotherapy-induced alopecia (CIA) is increasing. Cold caps are placed onto the hair-bearing areas of the scalp for varying time periods before, during, and after cytotoxic chemotherapy cycles. Although not yet reported, improper application procedures could result in undesirable adverse events (AEs). At present, there are no evidence-based scalp cooling protocols, and there is no regulatory oversight of their use. OBJECTIVE To report the occurrence of cold thermal injury (frostbite) on the scalp, following the use of cold caps for the prevention of CIA. MATERIALS AND METHODS We identified four patients who developed cold thermal injuries on the scalp following the application of cold caps. Medical records were analyzed to retrieve the demographic, clinical, and histologic characteristics. RESULTS The cold thermal injuries in our patients were grade 1/2 in severity and improved with topical interventions, although mild persistent alopecia ensued in 3 patients. The true incidence of such injuries in this setting however, remains unknown. CONCLUSIONS Cold thermal cold injuries are likely an infrequent and preventable AE that may result from improper device application procedures during scalp cooling. Although these untoward events are usually mild to moderate in severity, the potential occurrence of long-term sequelae (e.g. permanent alopecia, scarring) are not known. Future prospective studies are needed to further elucidate the risk and standardized delivery methods, and patient/clinical education. PMID:27146710

Improvements in Cold-Plate Fabrication

NASA Technical Reports Server (NTRS)

Zaffetti, Mark A.; Taddey, Edmund P.; Laurin, Michael B.; Chabebe, Natalia

2012-01-01

Five improvements are reported in cold-plate fabrication. This cold plate is part of a thermal control system designed to serve on space missions. The first improvement is the merging of the end sheets of the cold plate with the face sheets of the structural honeycomb panel. The cold plate, which can be a brazed assembly, uses the honeycomb face sheet as its end sheet. Thus, when the honeycomb panel is fabricated, the face sheet that is used is already part of the cold plate. In addition to reducing weight, costs, and steps, the main benefit of this invention is that it creates a more structurally sound assembly. The second improvement involves incorporation of the header into the closure bar to pass the fluid to a lower layer. Conventional designs have used a separate header, which increases the geometry of the system. The improvement reduces the geometry, thus allowing the cold plate to fit into smaller area. The third improvement eliminates the need of hose, tube, or manifold to supply the cooling fluid externally. The external arrangement can be easily damaged and is vulnerable to leakage. The new arrangement incorporates an internal fluid transfer tube. This allows the fluid to pass from one cold plate to the other without any exposed external features. The fourth improvement eliminates separate fabrication of cold plate(s) and structural members followed by a process of attaching them to each other. Here, the structural member is made of material that can be brazed just as that of the cold plate. Now the structural member and the cold plate can be brazed at the same time, creating a monolithic unit, and thus a more structurally sound assembly. Finally, the fifth improvement is the elimination of an additional welding step that can damage the braze joints. A tube section, which is usually welded on after the braze process, is replaced with a more structurally sound configuration that can be brazed at the same time as the rest of the cold plate.

Ultra-Deep Drilling Cost Reduction; Design and Fabrication of an Ultra-Deep Drilling Simulator (UDS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindstrom, Jason

2010-01-31

Ultra-deep drilling, below about 20,000 ft (6,096 m), is extremely expensive and limits the recovery of hydrocarbons at these depths. Unfortunately, rock breakage and cuttings removal under these conditions is not understood. To better understand and thus reduce cost at these conditions an ultra-deep single cutter drilling simulator (UDS) capable of drill cutter and mud tests to sustained pressure and temperature of 30,000 psi (207 MPa) and 482 °F (250 °C), respectively, was designed and manufactured at TerraTek, a Schlumberger company, in cooperation with the Department of Energy’s National Energy Technology Laboratory. UDS testing under ultra-deep drilling conditions offers anmore » economical alternative to high day rates and can prove or disprove the viability of a particular drilling technique or fluid to provide opportunity for future domestic energy needs.« less

Development and ultra-structure of an ultra-thin silicone epidermis of bioengineered alternative tissue.

PubMed

Wessels, Quenton; Pretorius, Etheresia

2015-08-01

Burn wound care today has a primary objective of temporary or permanent wound closure. Commercially available engineered alternative tissues have become a valuable adjunct to the treatment of burn injuries. Their constituents can be biological, alloplastic or a combination of both. Here the authors describe the aspects of the development of a siloxane epidermis for a collagen-glycosaminoglycan and for nylon-based artificial skin replacement products. A method to fabricate an ultra-thin epidermal equivalent is described. Pores, to allow the escape of wound exudate, were punched and a tri-filament nylon mesh or collagen scaffold was imbedded and silicone polymerisation followed at 120°C for 5 minutes. The ultra-structure of these bilaminates was assessed through scanning electron microscopy. An ultra-thin biomedical grade siloxane film was reliably created through precision coating on a pre-treated polyethylene terephthalate carrier. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

A low-cost, ultra-fast and ultra-low noise preamplifier for silicon avalanche photodiodes

NASA Astrophysics Data System (ADS)

Gasmi, Khaled

2018-02-01

An ultra-fast and ultra-low noise preamplifier for amplifying the fast and weak electrical signals generated by silicon avalanche photodiodes has been designed and developed. It is characterized by its simplicity, compactness, reliability and low cost of construction. A very wide bandwidth of 300 MHz, a very good linearity from 1 kHz to 280 MHz, an ultra-low noise level at the input of only 1.7 nV Hz-1/2 and a very good stability are its key features. The compact size (70 mm  ×  90 mm) and light weight (45 g), as well as its excellent characteristics, make this preamplifier very competitive compared to any commercial preamplifier. The preamplifier, which is a main part of the detection system of a homemade laser remote sensing system, has been successfully tested. In addition, it is versatile and can be used in any optical detection system requiring high speed and very low noise electronics.

Deep influence of passive low energy consumption multi-storey residential building in cold region

NASA Astrophysics Data System (ADS)

Shuai, Zhang; Lihua, Zhao; Rong, Jin; Dong, Junyan

2018-02-01

The example of passive architecture demonstration building in Jilin Province, China, based on the practical experience of this project, the control index of passive and low energy consumption residential buildings in cold and passive buildings is referenced by reference to the German construction standard and the Chinese residence construction document, “passive ultra-low energy consumption green Building Technology Guide (Trial)”. The requirement of passive low energy residential buildings on the ground heat transfer coefficient limits is determined, and the performance requirements of passive residential buildings are discussed. This paper analyzes the requirement of the passive low energy residential building on the ground heat transfer coefficient limit, and probes into the influence factors of the ground thermal insulation of the passive low energy consumption residential building. The construction method of passive low energy consumption residential building is proposed.

Familial polymorphous cold eruption.

PubMed

Martin, S; Eastern, J; Knox, J M

1981-02-01

An erythematous, burning papular eruption, constitutional symptoms, fever, and arthropathy developed in a 65-year-old patient after cold exposure. Involvement of other family members occurred in an autosomal dominant pattern. Histopathologic examination of a biopsy specimen revealed telangiectasia and primarily neutrophilic perivascular inflammation, consistent with earlier biopsy reports of this syndrome. Although previously called "familial cold urticaria," this disease is not characterized by urticaria and may be best descriptively termed, "familial polymorphous cold eruption."

Cold chain monitoring during cold transportation of human corneas for transplantation.

PubMed

Net, M; Trias, E; Navarro, A; Ruiz, A; Diaz, P; Fontenla, J R; Manyalich, M

2003-08-01

As recommended by international standards the cornea should be maintained in a specific temperature range (2 degrees -8 degrees C) to guarantee its viability. However, there is no standard packaging method to maintain these conditions during transport. Our packaging system is similar to those used by the main eye banks in Spain and elsewhere in Europe. The objective is to monitor the cold chain in the current packaging method to validate the maintenance of temperature within the adequate range for a minimum 24-hour period. The effects of the following variables were studied: number and freezing temperature of the cold packs; air volume in the packaging system; position of the cornea in the packaging system; and the wall section of the container. Exterior temperature was maintained constant at 20 degrees to 24 degrees C. The cold chain was monitored using a device that measures temperature continuously and for which a histogram of temperature variation can be downloaded to a computer for further analysis. When the cold packs were frozen to -40 degrees C or the number of cold packs increased to four, the temperature decreased quickly to 0 degrees C and the transport period was not prolonged. The main objective was to improve isolation by reducing inner air volume, and maintaining the position of the cornea in the container. The currently used cold packaging systems (not frozen, 4 degrees C) do not maintain the temperature within the accepted range for the required distribution period. The improved system maintains the cornea at between 2 degrees C and 6 degrees C for a minimum of 24 hours.

Review on the progress of ultra-precision machining technologies

NASA Astrophysics Data System (ADS)

Yuan, Julong; Lyu, Binghai; Hang, Wei; Deng, Qianfa

2017-06-01

Ultra-precision machining technologies are the essential methods, to obtain the highest form accuracy and surface quality. As more research findings are published, such technologies now involve complicated systems engineering and been widely used in the production of components in various aerospace, national defense, optics, mechanics, electronics, and other high-tech applications. The conception, applications and history of ultra-precision machining are introduced in this article, and the developments of ultra-precision machining technologies, especially ultra-precision grinding, ultra-precision cutting and polishing are also reviewed. The current state and problems of this field in China are analyzed. Finally, the development trends of this field and the coping strategies employed in China to keep up with the trends are discussed.

Age and Ethnic Differences in Cold Weather and Contagion Theories of Colds and Flu

ERIC Educational Resources Information Center

Sigelman, Carol K.

2012-01-01

Age and ethnic group differences in cold weather and contagion or germ theories of infectious disease were explored in two studies. A cold weather theory was frequently invoked to explain colds and to a lesser extent flu but became less prominent with age as children gained command of a germ theory of disease. Explanations of how contact with…

Measurement of magnetic field aligned potential differences using high resolution conjugate photoelectron energy spectra

NASA Technical Reports Server (NTRS)

Peterson, W. K.; Doering, J. P.; Potemra, T. A.; Bostrom, C. O.; Brace, L. H.; Heelis, R. A.; Hanson, W. B.

1977-01-01

Simultaneous high-resolution observations of a distinctive feature in the energy spectrum of conjugate photoelectrons and spacecraft potential relative to the local ionosphere have allowed the net potential difference between magnetic conjugate points at latitudes below the region of low-energy (i.e., lower than 100 eV) auroral electron precipitation to be determined. Measurements made at 300 km from Atmosphere Explorer C show that there is normally no net potential difference between hemispheres in this region, which extended up to invariant latitudes as high as 74 deg. Two types of apparently related anomalous behavior were infrequently observed at high latitudes. During these periods the incident flux of conjugate photoelectrons was either decelerated by about 3 eV or was not detected.

Consumption of ultra-processed foods predicts diet quality in Canada.

PubMed

Moubarac, Jean-Claude; Batal, M; Louzada, M L; Martinez Steele, E; Monteiro, C A

2017-01-01

This study describes food consumption patterns in Canada according to the types of food processing using the Nova classification and investigates the association between consumption of ultra-processed foods and the nutrient profile of the diet. Dietary intakes of 33,694 individuals from the 2004 Canadian Community Health Survey aged 2 years and above were analyzed. Food and drinks were classified using Nova into unprocessed or minimally processed foods, processed culinary ingredients, processed foods and ultra-processed foods. Average consumption (total daily energy intake) and relative consumption (% of total energy intake) provided by each of the food groups were calculated. Consumption of ultra-processed foods according to sex, age, education, residential location and relative family revenue was assessed. Mean nutrient content of ultra-processed foods and non-ultra-processed foods were compared, and the average nutrient content of the overall diet across quintiles of dietary share of ultra-processed foods was measured. In 2004, 48% of calories consumed by Canadians came from ultra-processed foods. Consumption of such foods was high amongst all socioeconomic groups, and particularly in children and adolescents. As a group, ultra-processed foods were grossly nutritionally inferior to non-ultra-processed foods. After adjusting for covariates, a significant and positive relationship was found between the dietary share of ultra-processed foods and the content in carbohydrates, free sugars, total and saturated fats and energy density, while an inverse relationship was observed with the dietary content in protein, fiber, vitamins A, C, D, B6 and B12, niacin, thiamine, riboflavin, as well as zinc, iron, magnesium, calcium, phosphorus and potassium. Lowering the dietary share of ultra-processed foods and raising consumption of hand-made meals from unprocessed or minimally processed foods would substantially improve the diet quality of Canadian. Copyright © 2016

Vaccines for the common cold.

PubMed

Simancas-Racines, Daniel; Guerra, Claudia V; Hidalgo, Ricardo

2013-06-12

The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat and fever (usually < 37.8˚C). The widespread morbidity it causes worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. We searched CENTRAL (2012, Issue 12), MEDLINE (1948 to January week 1, 2013), EMBASE (1974 to January 2013), CINAHL (1981 to January 2013) and LILACS (1982 to January 2013). Randomised controlled trials (RCTs) of any virus vaccines to prevent the common cold in healthy people. Two review authors independently evaluated methodological quality and extracted trial data. Disagreements were resolved by discussion or by consulting a third review author. This review included one RCT with 2307 healthy participants; all of them were analysed. This trial compared the effect of an adenovirus vaccine against a placebo. No statistically significant difference in common cold incidence was found: there were 13 events in 1139 participants in the vaccines group and 14 events in 1168 participants in the placebo group; risk ratio (RR) 0.95, 95% confidence interval (CI) 0.45 to 2.02, P = 0.90). No adverse events related to the live vaccine were reported. This Cochrane review has found a lack of evidence on the effects of vaccines for the common cold in healthy people. Only one RCT was found and this did not show differences between comparison groups; it also had a high risk of bias. There are no conclusive data to support the use of

Comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones.

PubMed

Carnes, Stephanie; O'Brien, Stacey; Szewczak, Angelica; Tremeau-Cayel, Lauriane; Rowe, Walter F; McCord, Bruce; Lurie, Ira S

2017-09-01

A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite-5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cold perception and gene expression differ in Olea europaea seed coat and embryo during drupe cold acclimation.

PubMed

D'Angeli, S; Falasca, G; Matteucci, M; Altamura, M M

2013-01-01

FAD2 and FAD7 desaturases are involved in cold acclimation of olive (Olea europaea) mesocarp. There is no research information available on cold acclimation of seeds during mesocarp cold acclimation or on differences in the cold response of the seed coat and embryo. How FAD2 and FAD7 affect seed coat and embryo cold responses is unknown. Osmotin positively affects cold acclimation in olive tree vegetative organs, but its role in the seeds requires investigation. OeFAD2.1, OeFAD2.2, OeFAD7 and Oeosmotin were investigated before and after mesocarp acclimation by transcriptomic, lipidomic and immunolabelling analyses, and cytosolic calcium concentration ([Ca(2+)](cyt)) signalling, F-actin changes and seed development were investigated by epifluorescence/histological analyses. Transient [Ca(2+)](cyt) rises and F-actin disassembly were found in cold-shocked protoplasts from the seed coat, but not from the embryo. The thickness of the outer endosperm cuticle increased during drupe exposure to lowering of temperature, whereas the embryo protoderm always lacked cuticle. OeFAD2 transcription increased in both the embryo and seed coat in the cold-acclimated drupe, but linoleic acid (i.e. the product of FAD2 activity) increased solely in the seed coat. Osmotin was immunodetected in the seed coat and endosperm of the cold-acclimated drupe, and not in the embryo. The results show cold responsiveness in the seed coat and cold tolerance in the embryo. We propose a role for the seed coat in maintaining embryo cold tolerance by increasing endosperm cutinization through FAD2 and osmotin activities. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

X-ray photoelectron spectroscopic study of water adsorption on iron sulphide minerals

NASA Astrophysics Data System (ADS)

Knipe, S. W.; Mycroft, J. R.; Pratt, A. R.; Nesbitt, H. W.; Bancroff, G. M.

1995-03-01

Samples of natural pyrrhotite and pyrite were fractured within the analytical chamber of an X-ray photoelectron spectrometer. The pristine mineral surfaces were then exposed, in the absence of oxygen, to total doses of 100, 200, 400, 800, 1400, 28,000, and 300,000 Langmuirs (L) of D2O. X-ray photoelectron spectroscopic (XPS) analyses were performed between each water dose, to investigate the interaction of these iron sulphide surfaces with water vapour. Recorded Fe and S photoelectron spectra showed no evidence of oxidation products on either mineral, even at highest D2O doses, nor could an oxide oxygen signal be fitted in the spectra for either mineral. On pyrrhotite, the O 1s spectra are composed of contributions from dominantly hydroxyl (at 532.0 ± 0.2 eV ) and subordinate chemisorbed water (at 533.5 ± 0.2 eV) signals. The main O is peak on pyrite is also formed from hydroxyl (531.0 ± 0.3 eV) and adsorbed water/hydroxyl (at 532.3 eV) signals. However, some O is spectra recorded on pyrite have peaks at anomalously high binding energies (>535 eV ). The anomalous high binding energy species are attributed to electrically-isolated OH/H2O, as reported elsewhere, and to liquid-like water, which has not previously been described in the literature. Pyrrhotite and pyrite interact with water via fundamentally different processes. Pyrrhotite reaction involves the donation of electron charge through Fe vacancies, whereas the water species detected on pyrite interact with the Fe 3d (eg) molecular orbital, and it is suggested that hydrogen bonding with the disulphide moiety may be important.

Paroxysmal cold hemoglobinuria (PCH)

MedlinePlus

... page: //medlineplus.gov/ency/article/000557.htm Paroxysmal cold hemoglobinuria (PCH) To use the sharing features on this page, please enable JavaScript. Paroxysmal cold hemoglobinuria (PCH) is a rare blood disorder in ...

Ultra High Bypass Integrated System Test

NASA Image and Video Library

2015-09-14

NASA’s Environmentally Responsible Aviation Project, in collaboration with the Federal Aviation Administration (FAA) and Pratt & Whitney, completed testing of an Ultra High Bypass Ratio Turbofan Model in the 9’ x 15’ Low Speed Wind Tunnel at NASA Glenn Research Center. The fan model is representative of the next generation of efficient and quiet Ultra High Bypass Ratio Turbofan Engine designs.

Photoelectron emission yield experiments on evolution of sub-gap states in amorphous In-Ga-Zn-O thin films with post deposition hydrogen treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashi, Kazushi, E-mail: hayashi.kazushi@kobelco.com; Hino, Aya; Tao, Hiroaki

Total photoyield emission spectroscopy (TPYS) was applied to study the evolution of sub-gap states in hydrogen-treated amorphous In-Ga-Zn-O (a-IGZO) thin films. The a-IGZO thin films were subjected to hydrogen radicals and subsequently annealed in ultra-high vacuum (UHV) conditions. A clear onset of the electron emission was observed at around 4.3 eV from the hydrogen-treated a-IGZO thin films. After successive UHV annealing at 300 °C, the onset in the TPYS spectra was shifted to 4.15 eV, and the photoelectron emission from the sub-gap states was decreased as the annealing temperature was increased. In conjunction with the results of thermal desorption spectrometer, it was deducedmore » that the hydrogen atoms incorporated in the a-IGZO thin films induced metastable sub-gap states at around 4.3 eV from vacuum level just after the hydrogenation. It was also suggested that the defect configuration was changed due to the higher temperature UHV annealing, and that the hydrogen atoms desorbed with the involvement of Zn atoms. These experiments produced direct evidence to show the formation of sub-gap states as a result of hydrogen incorporation into the a-IGZO thin films.« less

Cold and Cough Medicines

MedlinePlus

... What can you do for your cold or cough symptoms? Besides drinking lots of fluids and getting ... medicines. There are lots of different cold and cough medicines, and they do different things. Nasal decongestants - ...

Electronic sideband locking of a broadly tunable 318.6 nm ultraviolet laser to an ultra-stable optical cavity

NASA Astrophysics Data System (ADS)

Bai, Jiandong; Wang, Jieying; He, Jun; Wang, Junmin

2017-04-01

We demonstrate frequency stabilization of a tunable 318.6 nm ultraviolet (UV) laser system using electronic sideband locking. By indirectly changing the frequency of a broadband electro-optic phase modulator, the laser can be continuously tuned over 4 GHz, while a 637.2 nm laser is directly stabilized to a high-finesse ultra-stable optical cavity. The doubling cavity also remains locked to the 637.2 nm light. We show that the tuning range depends mainly on the gain-flattening region of the modulator and the piezo-tunable range of the seed laser. The frequency-stabilized tunable UV laser system is able to compensate for the offset between reference and target frequencies, and has potential applications in precision spectroscopy of cold atoms.

Improved growth of GaN layers on ultra thin silicon nitride/Si (1 1 1) by RF-MBE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Mahesh; Roul, Basanta; Central Research Laboratory, Bharat Electronics, Bangalore 560013

High-quality GaN epilayers were grown on Si (1 1 1) substrates by molecular beam epitaxy using a new growth process sequence which involved a substrate nitridation at low temperatures, annealing at high temperatures, followed by nitridation at high temperatures, deposition of a low-temperature buffer layer, and a high-temperature overgrowth. The material quality of the GaN films was also investigated as a function of nitridation time and temperature. Crystallinity and surface roughness of GaN was found to improve when the Si substrate was treated under the new growth process sequence. Micro-Raman and photoluminescence (PL) measurement results indicate that the GaN filmmore » grown by the new process sequence has less tensile stress and optically good. The surface and interface structures of an ultra thin silicon nitride film grown on the Si surface are investigated by core-level photoelectron spectroscopy and it clearly indicates that the quality of silicon nitride notably affects the properties of GaN growth.« less

Photoelectron spectra and biological activity of cinnamic acid derivatives revisited.

PubMed

Novak, Igor; Klasinc, Leo; McGlynn, Sean P

2018-01-15

The electronic structures of several derivatives of cinnamic acid have been studied by UV photoelectron spectroscopy (UPS) and Green's function quantum chemical calculations. The spectra reveal the presence of dimers in the gas phase for p-coumaric and ferulic acids. The electronic structure analysis has been related to the biological properties of these compounds through the analysis of some structure-activity relationships (SAR). Copyright © 2017 Elsevier B.V. All rights reserved.

Eclipse and noneclipse differential photoelectron flux.

NASA Technical Reports Server (NTRS)

Knudsen, W. C.; Sharp, G. W.

1972-01-01

Differential photoelectron flux in the energy range of 3 to 50 eV has been measured in the lower ionosphere both during the March 7, 1970, solar eclipse and during a period 24 hours earlier. The two measurements were made with identical retarding potential analyzers carried on Nike-Apache rocket flights to a peak altitude of approximately 180 km. The differential electron flux spectrum within totality on the eclipse flight had the same shape but was a factor of 10 smaller in magnitude than that measured on the control day at altitudes between 120 and 180 km, an expected result for an eclipse function decreasing to 1/10 at totality. The differential flux spectrum measured in full sun has the same general energy dependence as that reported by Doering et al. (1970) but is larger by a factor of 2 to 10, depending on altitude.

Blood-collection device for trace and ultra-trace metal specimens evaluated.

PubMed

Moyer, T P; Mussmann, G V; Nixon, D E

1991-05-01

We evaluated the evacuated phlebotomy tube designed specifically for trace metal analysis by Sherwood Medical Co. Pools of human serum containing known concentrations of aluminum, arsenic, calcium, cadmium, copper, chromium, iron, lead, magnesium, manganese, mercury, selenium, and zinc were exposed to the tube and rubber stopper for defined periods ranging from 5 min to 24 h. Analysis for each element was performed in a randomized fashion under rigidly controlled conditions by use of standard electrothermal atomization atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy, and cold vapor atomic absorption spectrometry. In addition, for comparative purposes, we collected blood samples from normal volunteers by use of ultra-clean polystyrene phlebotomy syringes as well as standard evacuated phlebotomy tubes. We conclude that, except for lead, there was no significant contribution of any trace element studied from the evaluated tube and stopper to the serum. Because whole blood is the usual specimen for lead testing, the observation of a trace amount of lead in this tube designed for serum collection is trivial.

Effects of cold temperatures on the excitability of rat trigeminal ganglion neurons that are not for cold sensing.

PubMed

Kanda, Hirosato; Gu, Jianguo G

2017-05-01

Aside from a small population of primary afferent neurons for sensing cold, which generate sensations of innocuous and noxious cold, it is generally believed that cold temperatures suppress the excitability of primary afferent neurons not responsible for cold sensing. These not-for-cold-sensing neurons include the majority of non-nociceptive and nociceptive afferent neurons. In this study we have found that the not-for-cold-sensing neurons of rat trigeminal ganglia (TG) change their excitability in several ways at cooling temperatures. In nearly 70% of not-for-cold-sensing TG neurons, a cooling temperature of 15°C increases their membrane excitability. We regard these neurons as cold-active neurons. For the remaining 30% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C either has no effect (cold-ineffective neurons) or suppress their membrane excitability (cold-suppressive neurons). For cold-active neurons, the cold temperature of 15°C increases their excitability as is evidenced by increases in action potential (AP) firing numbers and/or the reduction in AP rheobase when these neurons are depolarized electrically. The cold temperature of 15°C significantly inhibits M-currents and increases membrane input resistance of cold-active neurons. Retigabine, an M-current activator, abolishes the effect of cold temperatures on AP firing, but not the effect of cold temperature on AP rheobase levels. The inhibition of M-currents and the increases of membrane input resistance are likely two mechanisms by which cooling temperatures increase the excitability of not-for-cold-sensing TG neurons. This article is part of the special article series "Pain". © 2015 International Society for Neurochemistry.

Immersion in Cold-Water Evaluation (ICE) and self-reported cold intolerance are reliable but unrelated measures.

PubMed

Traynor, Robyn; MacDermid, Joy C

2008-09-01

Intolerance to the cold is common following peripheral nerve injury and surgery of the upper extremity. Despite its prevalence, the exact pathophysiology and natural history of this condition are not well understood. Subjective, self-report questionnaires have been created and validated as reliable measures of post-traumatic cold intolerance. The difficulty currently lies in assigning an objective measure to this predominantly subjective phenomenon. The present study evaluated the test-retest reliability of a proposed objective measure of cold intolerance, the Immersion in Cold-water Evaluation (ICE), and its correlation with subjective measures in healthy control subjects. Two age groups were also compared to investigate the effect of age on cold intolerance and temperature recovery. On two separate testing days, subjects completed three health-related questionnaires and submersed their dominant hands in cold water. The temperature of their second and fifth digits was monitored during recovery. Both the objective cold-provocation testing and the subjective self-report questionnaires were highly reliable albeit not significantly correlated. No significant temperature recovery trend was noted between the age groups. Post-traumatic cold intolerance is postulated to have both a vascular and neural etiology among other contributing causes. The protocol studied here was centered predominantly on the former etiology, examining peripheral blood flow and associated temperature recovery. This study established ICE as a reliable means to objectively measure cold response, supplementing information provided by previously validated self-report methods.

Modeling and parameterization of photoelectrons emitted in condensed matter by linearly polarized synchrotron radiation

NASA Astrophysics Data System (ADS)

Jablonski, A.

2018-01-01

Growing availability of synchrotron facilities stimulates an interest in quantitative applications of hard X-ray photoemission spectroscopy (HAXPES) using linearly polarized radiation. An advantage of this approach is the possibility of continuous variation of radiation energy that makes it possible to control the sampling depth for a measurement. Quantitative applications are based on accurate and reliable theory relating the measured spectral features to needed characteristics of the surface region of solids. A major complication in the case of polarized radiation is an involved structure of the photoemission cross-section for hard X-rays. In the present work, details of the relevant formalism are described and algorithms implementing this formalism for different experimental configurations are proposed. The photoelectron signal intensity may be considerably affected by variation in the positioning of the polarization vector with respect to the surface plane. This information is critical for any quantitative application of HAXPES by polarized X-rays. Different quantitative applications based on photoelectrons with energies up to 10 keV are considered here: (i) determination of surface composition, (ii) estimation of sampling depth, and (iii) measurements of an overlayer thickness. Parameters facilitating these applications (mean escape depths, information depths, effective attenuation lengths) were calculated for a number of photoelectron lines in four elemental solids (Si, Cu, Ag and Au) in different experimental configurations and locations of the polarization vector. One of the considered configurations, with polarization vector located in a plane perpendicular to the surface, was recommended for quantitative applications of HAXPES. In this configurations, it was found that the considered parameters vary weakly in the range of photoelectron emission angles from normal emission to about 50° with respect to the surface normal. The averaged values of the mean

Time-resolved photoelectron spectroscopy of nitrobenzene and its aldehydes

NASA Astrophysics Data System (ADS)

Schalk, Oliver; Townsend, Dave; Wolf, Thomas J. A.; Holland, David M. P.; Boguslavskiy, Andrey E.; Szöri, Milan; Stolow, Albert

2018-01-01

We report the first femtosecond time-resolved photoelectron spectroscopy study of 2-, 3- and 4-nitrobenzaldehyde (NBA) and nitrobenzene (NBE) in the gas phase upon excitation at 200 nm. In 3- and 4-NBA, the dynamics follow fast intersystem crossing within 1-2 picoseconds. In 2-NBA and NBE, the dynamics are faster (∼ 0.5 ps). 2-NBA undergoes hydrogen transfer similar to solution phase dynamics. NBE either releases NO2 in the excited state or converts internally back to the ground state. We discuss why these channels are suppressed in the other nitrobenzaldehydes.

Age and ethnic differences in cold weather and contagion theories of colds and flu.

PubMed

Sigelman, Carol K

2012-02-01

Age and ethnic group differences in cold weather and contagion or germ theories of infectious disease were explored in two studies. A cold weather theory was frequently invoked to explain colds and to a lesser extent flu but became less prominent with age as children gained command of a germ theory of disease. Explanations of how contact with other people causes disease were more causally sophisticated than explanations of how cold weather causes it. Finally, Mexican American and other minority children were more likely than European American children to subscribe to cold weather theories, a difference partially but not wholly attributable to ethnic group differences in parent education. Findings support the value of an intuitive or naïve theories perspective in understanding developmental and sociocultural differences in concepts of disease and in planning health education to help both children and their parents shed misconceptions so that they can focus on effective preventive actions.

Vernalizing cold is registered digitally at FLC.

PubMed

Angel, Andrew; Song, Jie; Yang, Hongchun; Questa, Julia I; Dean, Caroline; Howard, Martin

2015-03-31

A fundamental property of many organisms is an ability to sense, evaluate, and respond to environmental signals. In some situations, generation of an appropriate response requires long-term information storage. A classic example is vernalization, where plants quantitatively sense long-term cold and epigenetically store this cold-exposure information to regulate flowering time. In Arabidopsis thaliana, stable epigenetic memory of cold is digital: following long-term cold exposure, cells respond autonomously in an all-or-nothing fashion, with the fraction of cells that stably silence the floral repressor flowering locus C (FLC) increasing with the cold exposure duration. However, during cold exposure itself it is unknown whether vernalizing cold is registered at FLC in individual cells in an all-or-nothing (digital) manner or is continuously varying (analog). Using mathematical modeling, we found that analog registration of cold temperature is problematic due to impaired analog-to-digital conversion into stable memory. This disadvantage is particularly acute when responding to short cold periods, but is absent when cold temperatures are registered digitally at FLC. We tested this prediction experimentally, exposing plants to short periods of cold interrupted with even shorter warm breaks. For FLC expression, we found that the system responds similarly to both interrupted and uninterrupted cold, arguing for a digital mechanism integrating long-term temperature exposure.

Vernalizing cold is registered digitally at FLC

PubMed Central

Angel, Andrew; Song, Jie; Yang, Hongchun; Questa, Julia I.; Dean, Caroline; Howard, Martin

2015-01-01

A fundamental property of many organisms is an ability to sense, evaluate, and respond to environmental signals. In some situations, generation of an appropriate response requires long-term information storage. A classic example is vernalization, where plants quantitatively sense long-term cold and epigenetically store this cold-exposure information to regulate flowering time. In Arabidopsis thaliana, stable epigenetic memory of cold is digital: following long-term cold exposure, cells respond autonomously in an all-or-nothing fashion, with the fraction of cells that stably silence the floral repressor FLOWERING LOCUS C (FLC) increasing with the cold exposure duration. However, during cold exposure itself it is unknown whether vernalizing cold is registered at FLC in individual cells in an all-or-nothing (digital) manner or is continuously varying (analog). Using mathematical modeling, we found that analog registration of cold temperature is problematic due to impaired analog-to-digital conversion into stable memory. This disadvantage is particularly acute when responding to short cold periods, but is absent when cold temperatures are registered digitally at FLC. We tested this prediction experimentally, exposing plants to short periods of cold interrupted with even shorter warm breaks. For FLC expression, we found that the system responds similarly to both interrupted and uninterrupted cold, arguing for a digital mechanism integrating long-term temperature exposure. PMID:25775579

Photoelectron imaging spectroscopy of niobium mononitride anion NbN{sup −}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berkdemir, Cuneyt; Department of Physics, Faculty of Science, Erciyes University, Kayseri 38039; Gunaratne, K. Don Dasitha

2016-07-21

In this gas-phase photoelectron spectroscopy study, we present the electron binding energy spectrum and photoelectron angular distributions of NbN{sup −} by the velocity-map imaging technique. The electron binding energy of NbN{sup −} is measured to be 1.42 ± 0.02 eV from the X band maximum which defines the 0-0 transition between ground states of anion and neutral. Theoretical binding energies which are the vertical and adiabatic detachment energies are computed by density functional theory to compare them with experiment. The ground state of NbN{sup −} is assigned to the {sup 2}Δ{sub 3/2} state and then the electronic transitions originating frommore » this state into X{sup 3}Δ{sub Ω} (Ω = 1-3), a{sup 1}Δ{sub 2}, A{sup 3}Σ{sub 1}{sup −}, and b{sup 1}Σ{sub 0}{sup +} states of NbN are reported to interpret the spectral features. As a prospective study for catalytic materials, spectral features of NbN{sup −} are compared with those of isovalent ZrO{sup −} and Pd{sup −}.« less

Electron Localization in Dissociating H 2 + by Retroaction of a Photoelectron onto Its Source

DOE PAGES

Waitz, M.; Asliturk, D.; Wechselberger, N.; ...

2016-01-26

We investigate the dissociation of H 2 + into a proton and a H 0 after single ionization with photons of an energy close to the threshold. We find that the p + and the H 0 do not emerge symmetrically in the case of the H 2 + dissociating along the 1sσ g ground state. Instead, a preference for the ejection of the p + in the direction of the escaping photoelectron can be observed. This symmetry breaking is strongest for very small electron energies. Our experiment is consistent with a recent prediction by Serov and Kheifets. In theirmore » model, which treats the photoelectron classically, the symmetry breaking is induced by the retroaction of the long-range Coulomb potential onto the dissociating H 2 +.« less

Spectromicroscope for the PHotoelectron Imaging of Nanostructures with X-rays (SPHINX): performance in biology, medicine and geology.

PubMed

Frazer, Bradley H; Girasole, Marco; Wiese, Lisa M; Franz, Torsten; De Stasio, Gelsomina

2004-05-01

Several X-ray PhotoElectron Emission spectroMicroscopes (X-PEEMs) exist around the world at this time. We present recent performance and resolution tests of one of them, the Spectromicroscope for PHotoelectron Imaging of Nanostructures with X-rays (SPHINX) X-PEEM, installed at the University of Wisconsin Synchrotron Radiation Center. With this state-of-the-art instrument we demonstrate chemical analysis capabilities on conducting and insulating specimens of diverse interests, and an unprecedented lateral resolution of 10 nm with monochromatic X-rays and 7.2 nm with ultraviolet illumination.

Theory and Application of Auger and Photoelectron Diffraction and Holography

NASA Astrophysics Data System (ADS)

Chen, Xiang

This dissertation addresses the theories and applications of three important surface analysis techniques: Auger electron diffraction (AED), x-ray photoelectron diffraction (XPD), and Auger and photoelectron holography. A full multiple-scattering scheme for the calculations of XPD, AED, and Kikuchi electron diffraction pattern from a surface cluster is described. It is used to simulate 64 eV M_{2,3}VV and 913 eV L_3VV AED patterns from Cu(001) surfaces, in order to test assertions in the literature that they are explicable by a classical "blocking" and channeling model. We find that this contention is not valid, and that only a quantum mechanical multiple-scattering calculation is able to simulate these patterns well. The same multiple scattering simulation scheme is also used to investigate the anomalous phenomena of peak shifts off the forward-scattering directions in photo -electron diffraction patterns of Mg KLL (1180 eV) and O 1s (955 eV) from MgO(001) surfaces. These shifts are explained by calculations assuming a short electron mean free path. Similar simulations of XPD from a CoSi_2(111) surface for Co-3p and Si-2p normal emission agree well with experimental diffraction patterns. A filtering process aimed at eliminating the self -interference effect in photoelectron holography is developed. A better reconstructed image from Si-2p XPD from a Si(001) (2 times 1) surface is seen at atomic resolution. A reconstruction algorithm which corrects for the anisotropic emitter waves as well as the anisotropic atomic scattering factors is used for holographic reconstruction from a Co-3p XPD pattern from a CoSi_2 surface. This new algorithm considerably improves the reconstructed image. Finally, a new reconstruction algorithm called "atomic position recovery by iterative optimization of reconstructed intensities" (APRIORI), which takes account of the self-interference terms omitted by the other holographic algorithms, is developed. Tests on a Ni-C-O chain and Si(111

Cold plasma decontamination of foods.

PubMed

Niemira, Brendan A

2012-01-01

Cold plasma is a novel nonthermal food processing technology that uses energetic, reactive gases to inactivate contaminating microbes on meats, poultry, fruits, and vegetables. This flexible sanitizing method uses electricity and a carrier gas, such as air, oxygen, nitrogen, or helium; antimicrobial chemical agents are not required. The primary modes of action are due to UV light and reactive chemical products of the cold plasma ionization process. A wide array of cold plasma systems that operate at atmospheric pressures or in low pressure treatment chambers are under development. Reductions of greater than 5 logs can be obtained for pathogens such as Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus. Effective treatment times can range from 120 s to as little as 3 s, depending on the food treated and the processing conditions. Key limitations for cold plasma are the relatively early state of technology development, the variety and complexity of the necessary equipment, and the largely unexplored impacts of cold plasma treatment on the sensory and nutritional qualities of treated foods. Also, the antimicrobial modes of action for various cold plasma systems vary depending on the type of cold plasma generated. Optimization and scale up to commercial treatment levels require a more complete understanding of these chemical processes. Nevertheless, this area of technology shows promise and is the subject of active research to enhance efficacy.

Future ultra-speed tube-flight

NASA Astrophysics Data System (ADS)

Salter, Robert M.

1994-05-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Future ultra-speed tube-flight

NASA Technical Reports Server (NTRS)

Salter, Robert M.

1994-01-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Cold medicines and children

MedlinePlus

... ingredient. Avoid giving more than one OTC cold medicine to your child. It may cause an overdose with severe side ... the dosage instructions strictly while giving an OTC medicine to your child. When giving OTC cold medicines to your child: ...

Electrochemical Corrosion Properties of Commercial Ultra-Thin Copper Foils

NASA Astrophysics Data System (ADS)

Yen, Ming-Hsuan; Liu, Jen-Hsiang; Song, Jenn-Ming; Lin, Shih-Ching

2017-08-01

Ultra-thin electrodeposited Cu foils have been developed for substrate thinning for mobile devices. Considering the corrosion by residual etchants from the lithography process for high-density circuit wiring, this study investigates the microstructural features of ultra-thin electrodeposited Cu foils with a thickness of 3 μm and their electrochemical corrosion performance in CuCl2-based etching solution. X-ray diffraction and electron backscatter diffraction analyses verify that ultra-thin Cu foils exhibit a random texture and equi-axed grains. Polarization curves show that ultra-thin foils exhibit a higher corrosion potential and a lower corrosion current density compared with conventional (220)-oriented foils with fan-like distributed fine-elongated columnar grains. Chronoamperometric results also suggest that ultra-thin foils possess superior corrosion resistance. The passive layer, mainly composed of CuCl and Cu2O, forms and dissolves in sequence during polarization.

Variable Mixed Orbital Character in the Photoelectron Angular Distribution of NO_{2}

NASA Astrophysics Data System (ADS)

Laws, Benjamin A.; Cavanagh, Steven J.; Lewis, Brenton R.; Gibson, Stephen T.

2017-06-01

NO_{2} a key component of photochemical smog and an important species in the Earth's atmosphere, is an example of a molecule which exhibits significant mixed orbital character in the HOMO. In photoelectron experiments the geometric properties of the parent anion orbital are reflected in the photoelectron angular distribution (PAD), an area of research that has benefited largely from the ability of velocity-map imaging (VMI) to simultaneously record both the energetic and angular information, with 100% collection efficiency. Photoelectron spectra of NO_{2}^{-}, taken over a range of wavelengths (355nm-520nm) with the ANU's VMI spectrometer, reveal an anomalous jump in the anisotropy parameter near threshold. Consequently, the orbital behavior of NO_{2}^{-} appears to be quite different near threshold compared to detachment at higher photon energies. This surprising effect is due to the Wigner Threshold law, which causes p orbital character to dominate the photodetachment cross-section near threshold, before the mixed s/d orbital character becomes significant at higher electron kinetic energies. By extending recent work on binary character models to form a more general expression, the variable mixed orbital character of NO_{2}^{-} is able to be described. This study provides the first multi-wavelength NO_{2} anisotropy data, which is shown to be in decent agreement with much earlier zero-core model predictions of the anisotropy parameter. K. J. Reed, A. H. Zimmerman, H. C. Andersen, and J. I. Brauman, J. Chem. Phys. 64, 1368, (1976). doi:10.1063/1.432404 D. Khuseynov, C. C. Blackstone, L. M. Culberson, and A. Sanov, J. Chem. Phys. 141, 124312, (2014). doi:10.1063/1.4896241 W. B. Clodius, R. M. Stehman, and S. B. Woo, Phys. Rev. A. 28, 760, (1983). doi:10.1103/PhysRevA.28.760 Research supported by the Australian Research Council Discovery Project Grant DP160102585

Garlic for the common cold.

PubMed

Lissiman, Elizabeth; Bhasale, Alice L; Cohen, Marc

2014-11-11

Background Garlic is alleged to have antimicrobial and antiviral properties that relieve the common cold, among other beneficial effects. There is widespread usage of garlic supplements. The common cold is associated with significant morbidity and economic consequences. On average, children have six to eight colds per year and adults have two to four.Objectives To determine whether garlic (Allium sativum) is effective for the prevention or treatment of the common cold, when compared to placebo, no treatment or other treatments.Search methods We searched CENTRAL (2014, Issue 7),OLDMEDLINE (1950 to 1965),MEDLINE (January 1966 to July week 5, 2014), EMBASE(1974 to August 2014) and AMED (1985 to August 2014).Selection criteria Randomised controlled trials of common cold prevention and treatment comparing garlic with placebo, no treatment or standard treatment.Data collection and analysis Two review authors independently reviewed and selected trials from searches, assessed and rated study quality and extracted relevant data.Main results In this updated review, we identified eight trials as potentially relevant from our searches. Again, only one trial met the inclusion criteria.This trial randomly assigned 146 participants to either a garlic supplement (with 180 mg of allicin content) or a placebo (once daily)for 12 weeks. The trial reported 24 occurrences of the common cold in the garlic intervention group compared with 65 in the placebo group (P value < 0.001), resulting in fewer days of illness in the garlic group compared with the placebo group (111 versus 366). The number of days to recovery from an occurrence of the common cold was similar in both groups (4.63 versus 5.63). Only one trial met the inclusion criteria, therefore limited conclusions can be drawn. The trial relied on self reported episodes of the common cold but was of reasonable quality in terms of randomisation and allocation concealment. Adverse effects included rash and odour. Authors' conclusions

Garlic for the common cold.

PubMed

Lissiman, Elizabeth; Bhasale, Alice L; Cohen, Marc

2012-03-14

Garlic is alleged to have antimicrobial and antiviral properties that relieve the common cold, among other beneficial effects. There is widespread usage of garlic supplements. The common cold is associated with significant morbidity and economic consequences. On average, children have six to eight colds per year and adults have two to four. To determine whether garlic (allium sativum) is effective for either the prevention or treatment of the common cold, when compared to placebo, no treatment or other treatments. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 4), which includes the Cochrane Acute Respiratory Infections Group Specialised Register, OLDMEDLINE (1950 to 1965), MEDLINE (January 1966 to November week 3, 2011), EMBASE (1974 to December 2011) and AMED (1985 to December 2011). Randomised controlled trials of common cold prevention and treatment comparing garlic with placebo, no treatment or standard treatment. Two review authors independently reviewed and selected trials from searches, assessed and rated study quality and extracted relevant data. Of the six trials identified as potentially relevant from our searches, only one trial met the inclusion criteria. This trial randomly assigned 146 participants to either a garlic supplement (with 180 mg of allicin content) or a placebo (once daily) for 12 weeks. The trial reported 24 occurrences of the common cold in the garlic intervention group compared with 65 in the placebo group (P < 0.001), resulting in fewer days of illness in the garlic group compared with the placebo group (111 versus 366). The number of days to recovery from an occurrence of the common cold was similar in both groups (4.63 versus 5.63). Only one trial met the inclusion criteria, therefore limited conclusions can be drawn. The trial relied on self reported episodes of the common cold but was of reasonable quality in terms of randomisation and allocation concealment. Adverse effects included rash and

Prevalence of cold-related complaints, symptoms and injuries in the general population: the FINRISK 2002 cold substudy

NASA Astrophysics Data System (ADS)

Raatikka, Veli-Pekka; Rytkönen, Mika; Näyhä, Simo; Hassi, Juhani

2007-05-01

The prevalence of cold-related complaints and symptoms in the general population has remained unknown. As part of the nationwide FINRISK 2002 health survey performed in Finland, 8,723 people aged 25 64 years filled in a questionnaire asking about the number of hours spent weekly in cold air, their sensations during cold exposure, cold-related complaints, symptoms of diseases, and degradation of performance. Cold thermal sensations at +5°C to -5°C were reported by 35% of men and 46% of women. Almost all subjects reported at least some cold-related complaints, most commonly musculoskeletal pain (men 30%, women 27%), followed by respiratory (25% / 29%), white finger (15% / 18%) and episodic peripheral circulation symptoms (12% / 15%). Decreased mental or physical performance in cold was reported by 75% of men and 70% of women, most commonly impairing manual dexterity and tactile sense. With declining temperature, the first symptom to emerge was pain in the elbow or the forearm (at -3°C), followed by increased excretion of mucus from the lungs (-5°C), while most other symptoms appeared only at lower temperatures of -15°C to -20°C. Most symptoms showed little or no association with the weekly duration of exposure, with the exception of cold-induced pain at most sites. Although, in general, Finns are well adapted to the cold climate, the high prevalence of cold-related complaints poses a challenge to the health care system in terms of decreased performance and the possibility that such symptoms predict more serious health effects, such as increased mortality.

Interface Energy Alignment of Atomic-Layer-Deposited VOx on Pentacene: an in Situ Photoelectron Spectroscopy Investigation.

PubMed

Zhao, Ran; Gao, Yuanhong; Guo, Zheng; Su, Yantao; Wang, Xinwei

2017-01-18

Ultrathin atomic-layer-deposited (ALD) vanadium oxide (VO x ) interlayer has recently been demonstrated for remarkably reducing the contact resistance in organic electronic devices (Adv. Funct. Mater. 2016, 26, 4456). Herein, we present an in situ photoelectron spectroscopy investigation (including X-ray and ultraviolet photoelectron spectroscopies) of ALD VO x grown on pentacene to understand the role of the ALD VO x interlayer for the improved contact resistance. The in situ photoelectron spectroscopy characterizations allow us to monitor the ALD growth process of VO x and trace the evolutions of the work function, pentacene HOMO level, and VO x defect states during the growth. The initial VO x growth is found to be partially delayed on pentacene in the first ∼20 ALD cycles. The underneath pentacene layer is largely intact after ALD. The ALD VO x is found to contain a high density of defect states starting from 0.67 eV below the Fermi level, and the energy level of these defect states is in excellent alignment with the HOMO level of pentacene, which therefore allows these VO x defect states to provide an efficient hole-injection pathway at the contact interface.

Ultra-weak sector, Higgs boson mass, and the dilaton

DOE PAGES

Allison, Kyle; Hill, Christopher T.; Ross, Graham G.

2014-09-26

The Higgs boson mass may arise from a portal coupling to a singlet fieldmore » $$\\sigma$$ which has a very large VEV $$f \\gg m_\\text{Higgs}$$. This requires a sector of "ultra-weak" couplings $$\\zeta_i$$, where $$\\zeta_i \\lesssim m_\\text{Higgs}^2 / f^2$$. Ultra-weak couplings are technically naturally small due to a custodial shift symmetry of $$\\sigma$$ in the $$\\zeta_i \\rightarrow 0$$ limit. The singlet field $$\\sigma$$ has properties similar to a pseudo-dilaton. We engineer explicit breaking of scale invariance in the ultra-weak sector via a Coleman-Weinberg potential, which requires hierarchies amongst the ultra-weak couplings.« less

X-Ray Photoelectron Spectroscopy of Stabilized Zirconia Films with Embedded Au Nanoparticles Formed under Irradiation with Gold Ions

NASA Astrophysics Data System (ADS)

Zubkov, S. Yu.; Antonov, I. N.; Gorshkov, O. N.; Kasatkin, A. P.; Kryukov, R. N.; Nikolichev, D. E.; Pavlov, D. A.; Shenina, M. E.

2018-03-01

Nanosized films of stabilized zirconia with Au nanoparticles formed by implanting Au ions are studied by X-ray photoelectron spectroscopy and transmission electron microscopy. The effect of irradiation of films with Au ions and postimplantation annealing on the distribution of chemical elements and zirconium- containing ZrO x compounds over the depth of the films is studied. Based on the data on the dimensional shift of the Au 4 f photoelectron line, the average value of the nanoparticle size is determined.

Cold-Weather Sports and Your Family

MedlinePlus

... Videos for Educators Search English Español Cold-Weather Sports and Your Family KidsHealth / For Parents / Cold-Weather ... kids while being active. Types of Cold-Weather Sports Skiing, snowboarding, ice skating, and snowshoeing are just ...

Chiral signatures in angle-resolved valence photoelectron spectroscopy of pure glycidol enantiomers.

PubMed

Garcia, Gustavo A; Nahon, Laurent; Harding, Chris J; Powis, Ivan

2008-03-28

Photoionization of the chiral molecule glycidol has been investigated in the valence region. Photoelectron circular dichroism (PECD) curves have been obtained at various photon energies by using circularly polarized VUV synchrotron radiation and a velocity map imaging technique to record angle-resolved photoelectron spectra (PES). The measured chiral asymmetries vary dramatically with the photon energy as well as with the ionized orbital, improving the effective orbital resolution of the PECD spectrum with respect to the PES. Typical asymmetry factors of 5% are observed, but the peak values measured range up to 15%. The experimental results are interpreted by continuum multiple scattering (CMS-Xalpha) calculations for several thermally accessible glycidol conformers. We find that a nearly quantitative agreement between theory and experiments can be achieved for the ionization of several molecular orbitals. Owing to the sensitivity of PECD to molecular conformation this allows us to identify the dominant conformer. The influence of intramolecular hydrogen bond orbital polarization is found to play a small yet significant role in determining the chiral asymmetry in the electron angular distributions.

Angle-resolved photoelectron spectroscopy of cyclopropane

NASA Astrophysics Data System (ADS)

Keller, P. R.; Taylor, J. W.; Carlson, Thomas A.; Whitley, T. A.; Grimm, F. A.

1985-10-01

The angular distribution parameter, β, determined for the valence orbitals (IP < 18 eV) of cyclopropane in the 10-30 eV photon energy range using dispersed polarized synchrotron radiation. The energy dependence of β for photoelectron energies between, 2 and 10 eV above threshold was found to be similar to those found previously for other σ orbitals. The effects of Jahn-Teller splitting on β for the 3e' orbital were found to be small but definitely present. The overall shape and magnitude of the β( hv) curve are, however, sufficiently for the different Jahn-Teller components that, for purposes of orbital assignments using β( hv) curves the shape and magnitude of the curves can be considered associated only with the initial state. Resonance photoionization features at a photon ener of ≈ 18 eV were observed in the 3e' and 3a' 1 orbitals and tentatively assigned to autoionization.

Photoelectron angular distributions for states of any mixed character: An experiment-friendly model for atomic, molecular, and cluster anions

NASA Astrophysics Data System (ADS)

Khuseynov, Dmitry; Blackstone, Christopher C.; Culberson, Lori M.; Sanov, Andrei

2014-09-01

We present a model for laboratory-frame photoelectron angular distributions in direct photodetachment from (in principle) any molecular orbital using linearly polarized light. A transparent mathematical approach is used to generalize the Cooper-Zare central-potential model to anionic states of any mixed character. In the limit of atomic-anion photodetachment, the model reproduces the Cooper-Zare formula. In the case of an initial orbital described as a superposition of s and p-type functions, the model yields the previously obtained s-p mixing formula. The formalism is further advanced using the Hanstorp approximation, whereas the relative scaling of the partial-wave cross-sections is assumed to follow the Wigner threshold law. The resulting model describes the energy dependence of photoelectron anisotropy for any atomic, molecular, or cluster anions, usually without requiring a direct calculation of the transition dipole matrix elements. As a benchmark case, we apply the p-d variant of the model to the experimental results for NO- photodetachment and show that the observed anisotropy trend is described well using physically meaningful values of the model parameters. Overall, the presented formalism delivers insight into the photodetachment process and affords a new quantitative strategy for analyzing the photoelectron angular distributions and characterizing mixed-character molecular orbitals using photoelectron imaging spectroscopy of negative ions.

Photoelectron angular distributions for states of any mixed character: an experiment-friendly model for atomic, molecular, and cluster anions.

PubMed

Khuseynov, Dmitry; Blackstone, Christopher C; Culberson, Lori M; Sanov, Andrei

2014-09-28

We present a model for laboratory-frame photoelectron angular distributions in direct photodetachment from (in principle) any molecular orbital using linearly polarized light. A transparent mathematical approach is used to generalize the Cooper-Zare central-potential model to anionic states of any mixed character. In the limit of atomic-anion photodetachment, the model reproduces the Cooper-Zare formula. In the case of an initial orbital described as a superposition of s and p-type functions, the model yields the previously obtained s-p mixing formula. The formalism is further advanced using the Hanstorp approximation, whereas the relative scaling of the partial-wave cross-sections is assumed to follow the Wigner threshold law. The resulting model describes the energy dependence of photoelectron anisotropy for any atomic, molecular, or cluster anions, usually without requiring a direct calculation of the transition dipole matrix elements. As a benchmark case, we apply the p-d variant of the model to the experimental results for NO(-) photodetachment and show that the observed anisotropy trend is described well using physically meaningful values of the model parameters. Overall, the presented formalism delivers insight into the photodetachment process and affords a new quantitative strategy for analyzing the photoelectron angular distributions and characterizing mixed-character molecular orbitals using photoelectron imaging spectroscopy of negative ions.

Photoelectron energy loss and spectral features deduced by the plasma line technique. [in topside F region

NASA Technical Reports Server (NTRS)

Abreu, V. J.; Carlson, H. C.

1977-01-01

Plasma line data gathered at the Arecibo Observatory are used to examine relative variations in topside F region differential photoelectron fluxes in the 5- to 20-eV range. A spectral feature not found in present theoretically calculated spectra is noted near 15 eV. A new approach to the interpretation of the measured spectra is taken, which allows a qualitative estimate of the relative importance of different energy loss mechanisms. The altitude variation of the observed photoelectron flux energy spectra at the higher altitudes (above 350 km) and the lower energies (less than 10 eV) agrees quantitatively with the expected variation of the spectrum.

COLD TRAP

DOEpatents

Milleron, N.

1963-03-12

An improved linear-flow cold trap is designed for highvacuum applications such as mitigating back migration of diffusion pump oil moiecules. A central pot of liquid nitrogen is nested within and supported by a surrounding, vertical, helical coil of metai sheet, all enveloped by a larger, upright, cylindrical, vacuum vessel. The vertical interstices between successive turns of the coil afford lineal, axial, high-vacuum passages between open mouths at top and bottom of said vessel, while the coil, being cold by virtue of thermal contact of its innermost turn with the nitrogen pot, affords expansive proximate condensation surfaces. (AEC)

Differential expression of the enzymes associated with cold-induced sweetening in long term cold stored potatoes

USDA-ARS?s Scientific Manuscript database

Accumulation of high levels of reducing sugars during cold storage (4-6°C) known as cold-induced sweetening (CIS) is a major post-harvest disorder and is one of the most significant concerns for the potato processing industry. The biochemical process of reducing sugar accumulation during cold stora...

Bacterial spore inactivation induced by cold plasma.

PubMed

Liao, Xinyu; Muhammad, Aliyu Idris; Chen, Shiguo; Hu, Yaqin; Ye, Xingqian; Liu, Donghong; Ding, Tian

2018-04-05

Cold plasma has emerged as a non-thermal technology for microbial inactivation in the food industry over the last decade. Spore-forming microorganisms pose challenges for microbiological safety and for the prevention of food spoilage. Inactivation of spores induced by cold plasma has been reported by several studies. However, the exact mechanism of spore deactivation by cold plasma is poorly understood; therefore, it is difficult to control this process and to optimize cold plasma processing for efficient spore inactivation. In this review, we summarize the factors that affect the resistance of spores to cold plasma, including processing parameters, environmental elements, and spore properties. We then describe possible inactivation targets in spore cells (e.g., outer structure, DNA, and metabolic proteins) that associated with inactivation by cold plasma according to previous studies. Kinetic models of the sporicidal activity of cold plasma have also been described here. A better understanding of the interaction between spores and cold plasma is essential for the development and optimization of cold plasma technology in food the industry.

Mountain Warfare and Cold Weather Operations

DTIC Science & Technology

2016-04-29

military purposes, cold regions are defined as any region where cold temperatures , unique terrain, and snowfall have a significant effect on military...because of the wind’s effect on the body’s perceived temperature . Wet cold leads to hypothermia, frost bite, and trench foot. Wet cold conditions are...combined cooling effect of ambient temperature and wind (wind chill) experienced by their troops (see Figure 1-5). The Environment ATP 3-90.97

Vaccines for the common cold.

PubMed

Simancas-Racines, Daniel; Franco, Juan Va; Guerra, Claudia V; Felix, Maria L; Hidalgo, Ricardo; Martinez-Zapata, Maria José

2017-05-18

The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat, and fever (usually < 37.8º C). The widespread morbidity caused by the common cold worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. This is an update of a Cochrane review first published in 2011 and previously updated in 2013. To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (September 2016), MEDLINE (1948 to September 2016), Embase (1974 to September 2016), CINAHL (1981 to September 2016), and LILACS (1982 to September 2016). We also searched three trials registers for ongoing studies and four websites for additional trials (February 2017). We included no language or date restrictions. Randomised controlled trials (RCTs) of any virus vaccines compared with placebo to prevent the common cold in healthy people. Two review authors independently evaluated methodological quality and extracted trial data. We resolved disagreements by discussion or by consulting a third review author. We found no additional RCTs for inclusion in this update. This review includes one RCT dating from the 1960s with an overall high risk of bias. The RCT included 2307 healthy participants, all of whom were included in analyses. This trial compared the effect of an adenovirus vaccine against placebo. No statistically significant difference in common cold incidence was found: there were 13 (1.14%) events in 1139 participants in the

Visible sub-band gap photoelectron emission from nitrogen doped and undoped polycrystalline diamond films

NASA Astrophysics Data System (ADS)

Elfimchev, S.; Chandran, M.; Akhvlediani, R.; Hoffman, A.

2017-07-01

In this study the origin of visible sub-band gap photoelectron emission (PEE) from polycrystalline diamond films is investigated. The PEE yields as a function of temperature were studied in the wavelengths range of 360-520 nm. Based on the comparison of electron emission yields from diamond films deposited on silicon and molybdenum substrates, with different thicknesses and nitrogen doping levels, we suggested that photoelectrons are generated from nitrogen related centers in diamond. Our results show that diamond film thickness and substrate material have no significant influence on the PEE yield. We found that nanocrystalline diamond films have low electron emission yields, compared to microcrystalline diamond, due to the presence of high amount of defects in the former, which trap excited electrons before escaping into the vacuum. However, the low PEE yield of nanocrystalline diamond films was found to increase with temperature. The phenomenon was explained by the trap assisted photon enhanced thermionic emission (ta-PETE) model. According to the ta-PETE model, photoelectrons are trapped by shallow traps, followed by thermal excitation at elevated temperatures and escape into the vacuum. Activation energies of trap levels were estimated for undoped nanocrystalline, undoped microcrystalline and N-doped diamond films using the Richardson-Dushman equation, which gives 0.13, 0.39 and 0.04 eV, respectively. Such low activation energy of trap levels makes the ta-PETE process very effective at elevated temperatures.

Theoretical and Experimental Photoelectron Spectroscopy Characterization of the Ground State of Thymine Cation.

PubMed

Majdi, Youssef; Hochlaf, Majdi; Pan, Yi; Lau, Kai-Chung; Poisson, Lionel; Garcia, Gustavo A; Nahon, Laurent; Al-Mogren, Muneerah Mogren; Schwell, Martin

2015-06-11

We report on the vibronic structure of the ground state X̃(2)A″ of the thymine cation, which has been measured using a threshold photoelectron photoion coincidence technique and vacuum ultraviolet synchrotron radiation. The threshold photoelectron spectrum, recorded over ∼0.7 eV above the ionization potential (i.e., covering the whole ground state of the cation) shows rich vibrational structure that has been assigned with the help of calculated anharmonic modes of the ground electronic cation state at the PBE0/aug-cc-pVDZ level of theory. The adiabatic ionization energy has been experimentally determined as AIE = 8.913 ± 0.005 eV, in very good agreement with previous high resolution results. The corresponding theoretical value of AIE = 8.917 eV has been calculated in this work with the explicitly correlated method/basis set (R)CCSD(T)-F12/cc-pVTZ-F12, which validates the theoretical approach and benchmarks its accuracy for future studies of medium-sized biological molecules.

Multi-reference approach to the calculation of photoelectron spectra including spin-orbit coupling.

PubMed

Grell, Gilbert; Bokarev, Sergey I; Winter, Bernd; Seidel, Robert; Aziz, Emad F; Aziz, Saadullah G; Kühn, Oliver

2015-08-21

X-ray photoelectron spectra provide a wealth of information on the electronic structure. The extraction of molecular details requires adequate theoretical methods, which in case of transition metal complexes has to account for effects due to the multi-configurational and spin-mixed nature of the many-electron wave function. Here, the restricted active space self-consistent field method including spin-orbit coupling is used to cope with this challenge and to calculate valence- and core-level photoelectron spectra. The intensities are estimated within the frameworks of the Dyson orbital formalism and the sudden approximation. Thereby, we utilize an efficient computational algorithm that is based on a biorthonormal basis transformation. The approach is applied to the valence photoionization of the gas phase water molecule and to the core ionization spectrum of the [Fe(H2O)6](2+) complex. The results show good agreement with the experimental data obtained in this work, whereas the sudden approximation demonstrates distinct deviations from experiments.

X-ray photoelectron spectroscopy for characterization of wood surfaces in adhesion studies

Treesearch

James F. Beecher; Charles R. Frihart

2005-01-01

X-ray photoelectron spectroscopy (XPS) is one of a set of tools that have been used to characterize wood surfaces. Among the advantages of XPS are surface sensitivity, identification of nearly all elements, and frequently, discrimination of bonding states. For these reasons, XPS seemed to be an appropriate tool to help explain the differences in bond strength under wet...

Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

USGS Publications Warehouse

Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.

2016-01-01

Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles (n = 151) and Burmese pythons (n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

Surface analysis of 316 stainless steel treated with cold atmospheric plasma

NASA Astrophysics Data System (ADS)

Williams, David F.; Kellar, Ewen J. C.; Jesson, David A.; Watts, John F.

2017-05-01

The surface of 316 stainless steel has been modified using cold atmospheric plasma (CAP) to increase the surface free energy (by cleaning the and chemically activating the surface)IN preparation for subsequent processes such as painting, coating or adhesive bonding. The analyses carried out, on CAP treated 316 stainless steel surfaces, includes X-ray photoelectron spectroscopy (XPS), imaging XPS (iXPS), and surface free energy (SFE) analysis using contact angle measurements. The CAP treatment is shown to increase the SFE of as-received 316 stainless steel from ∼39 mJ m-1 to >72 mJ m-1 after a short exposure to the plasma torch. This was found to correlate to a reduction in adventitious carbon, as determined by XPS analysis of the surface. The reduction from ∼90 at% to ∼30% and ∼39 at%, after being plasma treated for 5 min and 15 s respectively, shows that the process is relatively quick at changing the surface. It is suggested that the mechanism that causes the increase in surface free energy is chain scission of the hydrocarbon contamination triggered by free electrons in the plasma plume followed by chemical functionalisation of the metal oxide surface and some of the remaining carbon contamination layer.

Liquid metal cold trap

DOEpatents

Hundal, Rolv

1976-01-01

A cold trap assembly for removing impurities from a liquid metal being provided with a hole between the incoming impure liquid metal and purified outgoing liquid metal which acts as a continuous bleed means and thus prevents the accumulation of cover gases within the cold trap assembly.

The cold reading technique.

PubMed

Dutton, D L

1988-04-15

For many people, belief in the paranormal derives from personal experience of face-to-face interviews with astrologers, palm readers, aura and Tarot readers, and spirit mediums. These encounters typically involve cold reading, a process in which a reader makes calculated guesses about a client's background and problems and, depending on the reaction, elaborates a reading which seems to the client so uniquely appropriate that it carries with it the illusion of having been produced by paranormal means. The cold reading process is shown to depend initially on the Barnum effect, the tendency for people to embrace generalized personality descriptions as idiosyncratically their own. Psychological research into the Barnum effect is critically reviewed, and uses of the effect by a professional magician are described. This is followed by detailed analysis of the cold reading performances of a spirit medium. Future research should investigate the degree to which cold readers may have convinced themselves that they actually possess psychic or paranormal abilities.

Cold hardiness in molluscs

NASA Astrophysics Data System (ADS)

Ansart, Armelle; Vernon, Philippe

2003-05-01

Molluscs inhabit all types of environments: seawater, intertidal zone, freshwater and land, and of course may have to deal with subzero temperatures. Ectotherm animals survive cold conditions by avoiding it by extensive supercooling (freezing avoidant species) or by bearing the freezing of their extracellular body fluids (freezing tolerant species). Although some studies on cold hardiness are available for intertidal molluscs, they are scarce for freshwater and terrestrial ones. Molluscs often exhibit intermediary levels of cold hardiness, with a moderate or low ability to supercool and a limited survival to the freezing of their tissues. Several factors could be involved: their dependence on water, their ability to enter dormancy, the probability of inoculative freezing in their environment, etc. Size is an important parameter in the development of cold hardiness abilities: it influences supercooling ability in land snails, which are rather freezing avoidant and survival to ice formation in intertidal organisms, which generally tolerate freezing.

TRPA1 Contributes to Cold Hypersensitivity

PubMed Central

Camino, Donato del; Murphy, Sarah; Heiry, Melissa; Barrett, Lee B.; Earley, Taryn J.; Cook, Colby A.; Petrus, Matt J.; Zhao, Michael; D'Amours, Marc; Deering, Nate; Brenner, Gary J.; Costigan, Michael; Hayward, Neil J.; Chong, Jayhong A.; Fanger, Christopher M.; Woolf, Clifford J.; Patapoutian, Ardem; Moran, Magdalene M.

2010-01-01

TRPA1 is a non-selective cation channel expressed by nociceptors. While it is widely accepted that TRPA1 serves as a broad irritancy receptor for a variety of reactive chemicals, its role in cold sensation remains controversial. Here, we demonstrate that mild cooling markedly increases agonist-evoked rat TRPA1 currents. In the absence of an agonist, even noxious cold only increases current amplitude slightly. These results suggest that TRPA1 is a key mediator of cold hypersensitivity in pathological conditions where reactive oxygen species and pro-inflammatory activators of the channel are present, but likely plays a comparatively minor role in acute cold sensation. Supporting this, cold hypersensitivity can be induced in wild-type but not Trpa1-/- mice by subcutaneous administration of a TRPA1 agonist. Furthermore, the selective TRPA1 antagonist HC-030031 reduces cold hypersensitivity in rodent models of inflammatory and neuropathic pain. PMID:21068322

Actively controlling coolant-cooled cold plate configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chainer, Timothy J.; Parida, Pritish R.

Cooling apparatuses are provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The cooling apparatus includes the cold plate and a controller. The cold plate couples to one or more electronic components to be cooled, and includes an adjustable physical configuration. The controller dynamically varies the adjustable physical configuration of the cold plate based on a monitored variable associated with the cold plate or the electronic component(s) being cooled by the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, formore » example, optimally cool the electronic component(s), and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the cold plate, the positioning of which may be adjusted based on the monitored variable.« less

Sustaining Health and Performance in the Cold: Environmental Medicine Guidance for Cold-Weather Operation.

DTIC Science & Technology

1992-07-01

or vehicle should be suspected of possible CO poisoning. 4. DO NOT APPLY OINTMENTS , SNOW OR ICE TO THE BURN , 3. Proper field sanitation is very AND DO...susceptible to cold injuries, and the use of indoor stoves may lead to burns or suffocation. Operational problems often arise in cold weather. Heavy...potential for body heat to escape. When the skin is exposed to cold, the brain signals the blood vessels in the skin to tighten, and blood flow to the skin

ENSO's far reaching connection to Indian cold waves.

PubMed

Ratnam, J V; Behera, Swadhin K; Annamalai, H; Ratna, Satyaban B; Rajeevan, M; Yamagata, Toshio

2016-11-23

During boreal winters, cold waves over India are primarily due to transport of cold air from higher latitudes. However, the processes associated with these cold waves are not yet clearly understood. Here by diagnosing a suite of datasets, we explore the mechanisms leading to the development and maintenance of these cold waves. Two types of cold waves are identified based on observed minimum surface temperature and statistical analysis. The first type (TYPE1), also the dominant one, depicts colder than normal temperatures covering most parts of the country while the second type (TYPE2) is more regional, with significant cold temperatures only noticeable over northwest India. Quite interestingly the first (second) type is associated with La Niña (El Niño) like conditions, suggesting that both phases of ENSO provide a favorable background for the occurrence of cold waves over India. During TYPE1 cold wave events, a low-level cyclonic anomaly generated over the Indian region as an atmospheric response to the equatorial convective anomalies is seen advecting cold temperatures into India and maintaining the cold waves. In TYPE2 cold waves, a cyclonic anomaly generated over west India anomalously brings cold winds to northwest India causing cold waves only in those parts.

Evaluation of cold workplaces: an overview of standards for assessment of cold stress.

PubMed

Holmér, Ingvar

2009-07-01

Many persons world wide are exposed to cold environments, either indoors for example in cold stores, or outdoors. Cold is a hazard to health and may affect safety and performance of work. Basis for the creation of safe and optimal working conditions may be obtained by the application of relevant international standards. ISO 11079 presents a method for evaluation of whole body heat balance. On the basis of climate and activity a required clothing insulation (IREQ) for heat balance is determined. For clothing with known insulation value an exposure time limited is calculated. ISO 11079 also includes criteria for assessment of local cooling. Finger temperatures should not be below 24 degrees C during prolonged exposures or 15 degrees C occasionally. Wind chill temperature indicates the risk of bare skin to freeze for combinations of wind and low temperatures. Special protection of airways is recommended at temperatures below -20 degrees C, in particular during heavy work. Additional standards are available describing evaluation strategies, work place observation checklists and checklist for medical screening. Risks associated with contact with cold surfaces can be evaluated with ISO 13732. The strategy and principles for assessment and prevention of cold stress are reviewed in this paper.

Cold War Paradigms and the Post-Cold War High School History Curriculum.

ERIC Educational Resources Information Center

McAninch, Stuart A.

1995-01-01

Discusses how Cold War ideological models provide a way to examine the U.S. role in world affairs. Discusses and compares on the writings of Paul Gagnon and Noam Chomsky on this topic. Concludes that students should stand outside both models to develop a meaningful perspective on the U.S. role during the Cold War. (CFR)

Maximising platelet availability by delaying cold storage.

PubMed

Wood, B; Johnson, L; Hyland, R A; Marks, D C

2018-04-06

Cold-stored platelets may be an alternative to conventional room temperature (RT) storage. However, cold-stored platelets are cleared more rapidly from circulation, reducing their suitability for prophylactic transfusion. To minimise wastage, it may be beneficial to store platelets conventionally until near expiry (4 days) for prophylactic use, transferring them to refrigerated storage to facilitate an extended shelf life, reserving the platelets for the treatment of acute bleeding. Two ABO-matched buffy-coat-derived platelets (30% plasma/70% SSP+) were pooled and split to produce matched pairs (n = 8 pairs). One unit was stored at 2-6°C without agitation (day 1 postcollection; cold); the second unit was stored at 20-24°C with constant agitation until day 4 then stored at 2-6°C thereafter (delayed-cold). All units were tested for in vitro quality periodically over 21 days. During storage, cold and delayed-cold platelets maintained a similar platelet count. While pH and HSR were significantly higher in delayed-cold platelets, other metabolic markers, including lactate production and glucose consumption, did not differ significantly. Furthermore, surface expression of phosphatidylserine and CD62P, release of soluble CD62P and microparticles were not significantly different, suggesting similar activation profiles. Aggregation responses of delayed-cold platelets followed the same trend as cold platelets once transferred to cold storage, gradually declining over the storage period. The metabolic and activation profile of delayed-cold platelets was similar to cold-stored platelets. These data suggest that transferring platelets to refrigerated storage when near expiry may be a viable option for maximising platelet inventories. © 2018 International Society of Blood Transfusion.

Body temperature and cold sensation during and following exercise under temperate room conditions in cold-sensitive young trained females.

PubMed

Fujii, Naoto; Aoki-Murakami, Erii; Tsuji, Bun; Kenny, Glen P; Nagashima, Kei; Kondo, Narihiko; Nishiyasu, Takeshi

2017-11-01

We evaluated cold sensation at rest and in response to exercise-induced changes in core and skin temperatures in cold-sensitive exercise trained females. Fifty-eight trained young females were screened by a questionnaire, selecting cold-sensitive (Cold-sensitive, n  = 7) and non-cold-sensitive (Control, n  = 7) individuals. Participants rested in a room at 29.5°C for ~100 min after which ambient temperature was reduced to 23.5°C where they remained resting for 60 min. Participants then performed 30-min of moderate intensity cycling (50% peak oxygen uptake) followed by a 60-min recovery. Core and mean skin temperatures and cold sensation over the whole-body and extremities (fingers and toes) were assessed throughout. Resting core temperature was lower in the Cold-sensitive relative to Control group (36.4 ± 0.3 vs. 36.7 ± 0.2°C). Core temperature increased to similar levels at end-exercise (~37.2°C) and gradually returned to near preexercise rest levels at the end of recovery (>36.6°C). Whole-body cold sensation was greater in the Cold-sensitive relative to Control group during resting at a room temperature of 23.5°C only without a difference in mean skin temperature between groups. In contrast, cold sensation of the extremities was greater in the Cold-sensitive group prior to, during and following exercise albeit this was not paralleled by differences in mean extremity skin temperature. We show that young trained females who are sensitive to cold exhibit augmented whole-body cold sensation during rest under temperate ambient conditions. However, this response is diminished during and following exercise. In contrast, cold sensation of extremities is augmented during resting that persists during and following exercise. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

International workshop on cold neutron sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, G.J.; West, C.D.

1991-08-01

The first meeting devoted to cold neutron sources was held at the Los Alamos National Laboratory on March 5--8, 1990. Cosponsored by Los Alamos and Oak Ridge National Laboratories, the meeting was organized as an International Workshop on Cold Neutron Sources and brought together experts in the field of cold-neutron-source design for reactors and spallation sources. Eighty-four people from seven countries attended. Because the meeting was the first of its kind in over forty years, much time was spent acquainting participants with past and planned activities at reactor and spallation facilities worldwide. As a result, the meeting had more ofmore » a conference flavor than one of a workshop. The general topics covered at the workshop included: Criteria for cold source design; neutronic predictions and performance; energy deposition and removal; engineering design, fabrication, and operation; material properties; radiation damage; instrumentation; safety; existing cold sources; and future cold sources.« less

Nanotherapy of cancer by photoelectrons emitted from the surface of nanoparticles exposed to nonionizing ultraviolet radiation.

PubMed

Letfullin, Renat R; George, Thomas F

2017-05-01

We introduce a new method for selectively destroying cancer cell organelles by electrons emitted from the surface of intracellularly localized nanoparticles exposed to the nonionizing ultraviolet (UV) radiation. We propose to target cancerous intracellular organelles by nanoparticles and expose them to UV radiation with energy density safe for healthy tissue. We simulate the number of photoelectrons produced by the nanoparticles made of various metals and radii, calculate their kinetic energy and compare it to the threshold energy for producing biological damage. Exposure of metal nanoparticles to UV radiation generates photoelectrons with kinetic energies up to 11 eV, which is high enough to produce single- to double-strand breaks in the DNA and damage the cancerous cell organelles.

Preliminary Analysis of the 30-m UltraBoom Flight Test

NASA Technical Reports Server (NTRS)

Agnes, Gregory S.; Abelson, Robert D.; Miyake, Robert; Lin, John K. H.; Welsh, Joe; Watson, Judith J.

2005-01-01

Future NASA missions require long, ultra-lightweight booms to enable solar sails, large sunshields, and other gossamer-type spacecraft structures. The space experiment discussed in this paper will flight validate the non-traditional ultra lightweight rigidizable, inflatable, isogrid structure utilizing graphite shape memory polymer (GR/SMP) called UltraBoom(TradeMark). The focus of this paper is the analysis of the 3-m ground test article. The primary objective of the mission is to show that a combination of ground testing and analysis can predict the on-orbit performance of an ultra lightweight boom that is scalable, predictable, and thermomechanically stable.

Cold-water acclimation does not modify whole-body fluid regulation during subsequent cold-water immersion.

PubMed

Stocks, J M; Patterson, M J; Hyde, D E; Jenkins, A B; Mittleman, K D; Taylor, N A S

2004-06-01

We investigated the impact of cold-water acclimation on whole-body fluid regulation using tracer-dilution methods to differentiate between the intracellular and extracellular fluid compartments. Seven euhydrated males [age 24.7 (8.7) years, mass 74.4 (6.4) kg, height 176.8 (7.8) cm, sum of eight skinfolds 107.4 (20.4) mm; mean (SD)] participated in a 14-day cold-water acclimation protocol, with 60-min resting cold-water stress tests [CWST; 18.1 (0.1) degrees C] on days 1, 8 and 15, and 90-min resting cold-water immersions [18.4 (0.4) degrees C] on intervening days. Subjects were immersed to the 4th intercostal space. Intracellular and extracellular fluid compartments, and plasma protein, electrolyte and hormone concentrations were investigated. During the first CWST, the intracellular fluid (5.5%) and plasma volumes were reduced (6.1%), while the interstitial fluid volume was simultaneously expanded (5.4%). This pattern was replicated on days 8 and 15, but did not differ significantly among test days. Acclimation did not produce significant changes in the pre-immersion distribution of total body water, or changes in plasma osmolality, total protein, electrolyte, atrial natriuretic peptide or aldosterone concentrations. Furthermore, a 14-day cold-water acclimation regimen did not elicit significant changes in body-fluid distribution, urine production, or the concentrations of plasma protein, electrolytes or the fluid-regulatory hormones. While acclimation trends were not evident, we have confirmed that fluid from extravascular cells is displaced into the interstitium during acute cold-water immersion, both before and after cold acclimation.

Cold air systems: Sleeping giant

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacCracken, C.D.

1994-04-01

This article describes how cold air systems help owners increase the profits from their buildings by reducing electric costs and improving indoor air quality through lower relative humidity levels. Cold air distribution involves energy savings, cost savings, space savings, greater comfort, cleaner air, thermal storage, tighter ducting, coil redesign, lower relative humidities, retrofitting, and improved indoor air quality (IAQ). It opens a door for architects, engineers, owners, builders, environmentalists, retrofitters, designers, occupants, and manufacturers. Three things have held up cold air's usage: multiple fan-powered boxes that ate up the energy savings of primary fans. Cold air room diffusers that providedmore » inadequate comfort. Condensation from ducts, boxes, and diffusers. Such problems have been largely eliminated through research and development by utilities and manufacturers. New cold air diffusers no longer need fan powered boxes. It has also been found that condensation is not a concern so long as the ducts are located in air conditioned space, such as drop ceilings or central risers, where relative humidity falls quickly during morning startup.« less

Measurements of wavelength-dependent double photoelectron emission from single photons in VUV-sensitive photomultiplier tubes

NASA Astrophysics Data System (ADS)

Faham, C. H.; Gehman, V. M.; Currie, A.; Dobi, A.; Sorensen, P.; Gaitskell, R. J.

2015-09-01

Measurements of double photoelectron emission (DPE) probabilities as a function of wavelength are reported for Hamamatsu R8778, R8520, and R11410 VUV-sensitive photomultiplier tubes (PMTs). In DPE, a single photon strikes the PMT photocathode and produces two photoelectrons instead of a single one. It was found that the fraction of detected photons that result in DPE emission is a function of the incident photon wavelength, and manifests itself below ~250 nm. For the xenon scintillation wavelength of 175 nm, a DPE probability of 18-24% was measured depending on the tube and measurement method. This wavelength-dependent single photon response has implications for the energy calibration and photon counting of current and future liquid xenon detectors such as LUX, LZ, XENON100/1T, Panda-X and XMASS.

Photoelectron spectroscopy and density functional calculations of CunBO2(OH)- (n = 1,2) clusters

NASA Astrophysics Data System (ADS)

Feng, Yuan; Hou, Gao-Lei; Xu, Hong-Guang; Zhang, Zeng-Guang; Zheng, Wei-Jun

2012-08-01

CunBO2(OH)- (n = 1, 2) clusters were studied by anion photoelectron spectroscopy and density functional calculations. From the experimental photoelectron spectra, the adiabatic detachment energy (ADE) and vertical detachment energy (VDE) of CuBO2(OH)- are determined to be 4.00 ± 0.08 and 4.26 ± 0.08 eV, and those of Cu2BO2(OH)- to be 2.30 ± 0.08 and 2.58 ± 0.08 eV. The structures of CunBO2(OH)- and their corresponding neutrals are assigned by comparison between theoretical calculations and experimental measurements. Both experiment and theory show that CuBO2(OH) can be viewed as a superhalogen, thus, confirmed that OH can behave like a halogen atom to participate in superhalogen formation.

Light-curve and spectral properties of ultra-stripped core-collapse supernovae

NASA Astrophysics Data System (ADS)

Moriya, Takashi J.

2017-11-01

We discuss light-curve and spectral properties of ultra-stripped core-collapse supernovae. Ultra-stripped supernovae are supernovae with ejecta masses of only ~0.1M ⊙ whose progenitors lose their envelopes due to binary interactions with their compact companion stars. We follow the evolution of an ultra-stripped supernova progenitor until core collapse and perform explosive nucleosynthesis calculations. We then synthesize light curves and spectra of ultra-stripped supernovae based on the nucleosynthesis results. We show that ultra-stripped supernovae synthesize ~0.01M ⊙ of the radioactive 56Ni, and their typical peak luminosity is around 1042 erg s-1 or -16 mag. Their typical rise time is 5 - 10 days. By comparing synthesized and observed spectra, we find that SN 2005ek and some of so-called calcium-rich gap transients like PTF10iuv may be related to ultra-stripped supernovae.

Evaporative cooling enhanced cold storage system

DOEpatents

Carr, Peter

1991-01-01

The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a portion of the added moisture. Preferably at least a portion of the added moisture comprises water condensed during the cooling of the warm air stream.

High-Resolution Photoionization, Photoelectron and Photodissociation Studies. Determination of Accurate Energetic and Spectroscopic Database for Combustion Radicals and Molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, Cheuk-Yiu

2016-04-25

The main goal of this research program was to obtain accurate thermochemical and spectroscopic data, such as ionization energies (IEs), 0 K bond dissociation energies, 0 K heats of formation, and spectroscopic constants for radicals and molecules and their ions of relevance to combustion chemistry. Two unique, generally applicable vacuum ultraviolet (VUV) laser photoion-photoelectron apparatuses have been developed in our group, which have used for high-resolution photoionization, photoelectron, and photodissociation studies for many small molecules of combustion relevance.

Finger cold-induced vasodilation of older Korean female divers, haenyeo: effects of chronic cold exposure and aging

NASA Astrophysics Data System (ADS)

Lee, Joo-Young; Park, Joonhee; Koh, Eunsook; Cha, Seongwon

2017-07-01

The aim of the present study was to evaluate the local cold tolerance of older Korean female divers, haenyeo ( N = 22) in terms of cold acclimatization and ageing. As control groups, older non-diving females ( N = 25) and young females from a rural area ( N = 15) and an urban area ( N = 51) participated in this study. To evaluate local cold tolerance, finger cold-induced vasodilation (CIVD) during finger immersion of 4 °C water was examined. As a result, older haenyeos showed greater minimum finger temperature and recovery finger temperature than older non-diving females ( P < 0.05), but similar responses in onset time, peak time, maximum finger temperature, frequency of CIVD, heart rate, blood pressure, and thermal and pain sensations as those of older non-diving females. Another novel finding was that young urban females showed more vulnerable responses to local cold in CIVD variables and subjective sensations when compared to older females, whereas young rural females had the most excellent cold tolerance in terms of maximum temperature and frequency of CIVD among the four groups ( P < 0.05). The present results imply that older haenyeos still retain cold acclimatized features on the periphery even though they changed their cotton diving suits to wet suits in the early 1980s. However, cardiovascular responses and subjective sensations to cold reflect aging effects. In addition, we suggest that young people who have been adapted to highly insulated clothing and indoor heating systems in winter should be distinguished from young people who were exposed to less modern conveniences when compared to the aged in terms of cold tolerance.

Finger cold-induced vasodilation of older Korean female divers, haenyeo: effects of chronic cold exposure and aging.

PubMed

Lee, Joo-Young; Park, Joonhee; Koh, Eunsook; Cha, Seongwon

2017-07-01

The aim of the present study was to evaluate the local cold tolerance of older Korean female divers, haenyeo (N = 22) in terms of cold acclimatization and ageing. As control groups, older non-diving females (N = 25) and young females from a rural area (N = 15) and an urban area (N = 51) participated in this study. To evaluate local cold tolerance, finger cold-induced vasodilation (CIVD) during finger immersion of 4 °C water was examined. As a result, older haenyeos showed greater minimum finger temperature and recovery finger temperature than older non-diving females (P < 0.05), but similar responses in onset time, peak time, maximum finger temperature, frequency of CIVD, heart rate, blood pressure, and thermal and pain sensations as those of older non-diving females. Another novel finding was that young urban females showed more vulnerable responses to local cold in CIVD variables and subjective sensations when compared to older females, whereas young rural females had the most excellent cold tolerance in terms of maximum temperature and frequency of CIVD among the four groups (P < 0.05). The present results imply that older haenyeos still retain cold acclimatized features on the periphery even though they changed their cotton diving suits to wet suits in the early 1980s. However, cardiovascular responses and subjective sensations to cold reflect aging effects. In addition, we suggest that young people who have been adapted to highly insulated clothing and indoor heating systems in winter should be distinguished from young people who were exposed to less modern conveniences when compared to the aged in terms of cold tolerance.

Physical Conditions in Ultra-fast Outflows in AGN

NASA Astrophysics Data System (ADS)

Kraemer, S. B.; Tombesi, F.; Bottorff, M. C.

2018-01-01

XMM-Newton and Suzaku spectra of Active Galactic Nuclei (AGN) have revealed highly ionized gas, in the form of absorption lines from H-like and He-like Fe. Some of these absorbers, ultra-fast outflows (UFOs), have radial velocities of up to 0.25c. We have undertaken a detailed photoionization study of high-ionization Fe absorbers, both UFOs and non-UFOs, in a sample of AGN observed by XMM-Newton. We find that the heating and cooling processes in UFOs are Compton-dominated, unlike the non-UFOs. Both types are characterized by force multipliers on the order of unity, which suggest that they cannot be radiatively accelerated in sub-Eddington AGN, unless they were much less ionized at their point of origin. However, such highly ionized gas can be accelerated via a magneto-hydrodynamic (MHD) wind. We explore this possibility by applying a cold MHD flow model to the UFO in the well-studied Seyfert galaxy, NGC 4151. We find that the UFO can be accelerated along magnetic streamlines anchored in the accretion disk. In the process, we have been able to constrain the magnetic field strength and the magnetic pressure in the UFO and have determined that the system is not in magnetic/gravitational equipartition. Open questions include the variability of the UFOs and the apparent lack of non-UFOs in UFO sources.

Ultra-widefield retinal imaging through a black intraocular lens.

PubMed

Yusuf, Imran H; Fung, Timothy H M; Patel, Chetan K

2015-09-01

To evaluate the feasibility of ultra-widefield retinal imaging in patients with near infrared (IR)-transmitting black intraocular lenses (IOLs). Oxford Eye Hospital, Oxford, United Kingdom. Laboratory evaluation of a diagnostic technology with interventional case report. The field of retinal imaging through a Morcher poly(methyl methacrylate) (PMMA) black IOL was determined in a purpose-built adult schematic model eye with the HRA2 Spectralis confocal scanning laser ophthalmoscope using standard imaging, Staurenghi retina lens-assisted imaging, and ultra-widefield noncontact imaging. Retinal imaging using each modality was then performed on a patient implanted with another Morcher PMMA black IOL model. Ultra-widefield noncontact imaging and lens-assisted imaging captured up to 150 degrees of field (versus 40 degrees with a standard confocal scanning laser ophthalmoscope). Ultra-widefield retinal images were successfully acquired in a patient eye with a black IOL. This study has identified the first ultra-widefield retinal imaging modalities for patients with near IR-transmitting black IOLs. Should larger studies confirm this finding, noncontact ultra-widefield confocal scanning laser ophthalmoscopy might be considered the gold standard imaging technique for retinal surveillance in patients with near IR-transmitting black IOLs. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Effects of the guard electrode on the photoelectron distribution around an electric field sensor

NASA Astrophysics Data System (ADS)

Miyake, Y.; Usui, H.; Kojima, H.

2011-05-01

We have developed a numerical model of a double-probe electric field sensor equipped with a photoelectron guard electrode for the particle-in-cell simulation. The model includes typical elements of modern double-probe sensors on, e.g., BepiColombo/MMO, Cluster, and THEMIS spacecraft, such as a conducting boom and a preamplifier housing called a puck. The puck is also used for the guard electrode, and its potential is negatively biased by reference to the floating spacecraft potential. We apply the proposed model to an analysis of an equilibrium plasma environment around the sensor by assuming that the sun illuminates the spacecraft from the direction perpendicular to the sensor deployment axis. As a simulation result, it is confirmed that a substantial number of spacecraft-originating photoelectrons are once emitted sunward and then fall onto the puck and sensing element positions. In order to effectively repel such photoelectrons coming from the sun direction, a potential hump for electrons, i.e., a negative potential region, should be created in a plasma region around the sunlit side of the guard electrode surface. The simulation results reveal the significance of the guard electrode potential being not only lower than the spacecraft body but also lower than the background plasma potential of the region surrounding the puck and the sensing element. One solution for realizing such an operational condition is to bias the guard potential negatively by reference to the sensor potential because the sensor is usually operated nearly at the background plasma potential.

Quantile Regression for Analyzing Heterogeneity in Ultra-high Dimension

PubMed Central

Wang, Lan; Wu, Yichao

2012-01-01

Ultra-high dimensional data often display heterogeneity due to either heteroscedastic variance or other forms of non-location-scale covariate effects. To accommodate heterogeneity, we advocate a more general interpretation of sparsity which assumes that only a small number of covariates influence the conditional distribution of the response variable given all candidate covariates; however, the sets of relevant covariates may differ when we consider different segments of the conditional distribution. In this framework, we investigate the methodology and theory of nonconvex penalized quantile regression in ultra-high dimension. The proposed approach has two distinctive features: (1) it enables us to explore the entire conditional distribution of the response variable given the ultra-high dimensional covariates and provides a more realistic picture of the sparsity pattern; (2) it requires substantially weaker conditions compared with alternative methods in the literature; thus, it greatly alleviates the difficulty of model checking in the ultra-high dimension. In theoretic development, it is challenging to deal with both the nonsmooth loss function and the nonconvex penalty function in ultra-high dimensional parameter space. We introduce a novel sufficient optimality condition which relies on a convex differencing representation of the penalized loss function and the subdifferential calculus. Exploring this optimality condition enables us to establish the oracle property for sparse quantile regression in the ultra-high dimension under relaxed conditions. The proposed method greatly enhances existing tools for ultra-high dimensional data analysis. Monte Carlo simulations demonstrate the usefulness of the proposed procedure. The real data example we analyzed demonstrates that the new approach reveals substantially more information compared with alternative methods. PMID:23082036

Fluid simulation of relativistic electron beam driven wakefield in a cold plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bera, Ratan Kumar; Sengupta, Sudip; Das, Amita

Excitation of wakefield in a cold homogeneous plasma, driven by an ultra-relativistic electron beam is studied in one dimension using fluid simulation techniques. For a homogeneous rigid beam having density (n{sub b}) less than or equal to half the plasma density (n{sub 0}), simulation results are found to be in good agreement with the analytical work of Rosenzweig [Phys. Rev. Lett. 58, 555 (1987)]. Here, Rosenzweig's work has been analytically extended to regimes where the ratio of beam density to plasma density is greater than half and results have been verified using simulation. Further in contrast to Rosenzweig's work, ifmore » the beam is allowed to evolve in a self-consistent manner, several interesting features are observed in simulation viz. splitting of the beam into beam-lets (for l{sub b} > λ{sub p}) and compression of the beam (for l{sub b} < λ{sub p}), l{sub b} and λ{sub p}, respectively, being the initial beam length and plasma wavelength.« less

Ultra-thin plasma panel radiation detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedman, Peter S.

An ultra-thin radiation detector includes a radiation detector gas chamber having at least one ultra-thin chamber window and an ultra-thin first substrate contained within the gas chamber. The detector further includes a second substrate generally parallel to and coupled to the first substrate and defining a gas gap between the first substrate and the second substrate. The detector further includes a discharge gas between the substrates and contained within the gas chamber, where the discharge gas is free to circulate within the gas chamber and between the first and second substrates at a given gas pressure. The detector further includesmore » a first electrode coupled to one of the substrates and a second electrode electrically coupled to the first electrode. The detector further includes a first discharge event detector coupled to at least one of the electrodes for detecting a gas discharge counting event in the electrode.« less

Development of an Apparatus for High-Resolution Auger Photoelectron Coincidence Spectroscopy (APECS) and Electron Ion Coincidence (EICO) Spectroscopy

NASA Astrophysics Data System (ADS)

Kakiuchi, Takuhiro; Hashimoto, Shogo; Fujita, Narihiko; Mase, Kazuhiko; Tanaka, Masatoshi; Okusawa, Makoto

We have developed an electron electron ion coincidence (EEICO) apparatus for high-resolution Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy. It consists of a coaxially symmetric mirror electron energy analyzer (ASMA), a miniature double-pass cylindrical mirror electron energy analyzer (DP-CMA), a miniature time-of-flight ion mass spectrometer (TOF-MS), a magnetic shield, an xyz stage, a tilt-adjustment mechanism, and a conflat flange with an outer diameter of 203 mm. A sample surface was irradiated by synchrotron radiation, and emitted electrons were energy-analyzed and detected by the ASMA and the DP-CMA, while desorbed ions were mass-analyzed and detected by the TOF-MS. The performance of the new EEICO analyzer was evaluated by measuring Si 2p photoelectron spectra of clean Si(001)-2×1 and Si(111)-7×7, and by measuring Si-L23VV-Si-2p Auger photoelectron coincidence spectra (Si-L23VV-Si-2p APECS) of clean Si(001)-2×1.

Optimal control of photoelectron emission by realistic waveforms

NASA Astrophysics Data System (ADS)

Solanpää, J.; Ciappina, M. F.; Räsänen, E.

2017-09-01

Recent experimental techniques in multicolor waveform synthesis allow the temporal shaping of strong femtosecond laser pulses with applications in the control of quantum mechanical processes in atoms, molecules, and nanostructures. Prediction of the shapes of the optimal waveforms can be done computationally using quantum optimal control theory. In this work we demonstrate the control of above-threshold photoemission of one-dimensional hydrogen model with pulses feasible for experimental waveform synthesis. By mixing different spectral channels and thus lowering the intensity requirements for individual channels, the resulting optimal pulses can extend the cutoff energies by at least up to 50% and bring up the electron yield by several orders of magnitude. Insights into the electron dynamics for optimized photoelectron emission are obtained with a semiclassical two-step model.

The Molecular and Cellular Basis of Cold Sensation

PubMed Central

2012-01-01

Of somatosensory modalities, cold is one of the more ambiguous percepts, evoking the pleasant sensation of cooling, the stinging bite of cold pain, and welcome relief from chronic pain. Moreover, unlike the precipitous thermal thresholds for heat activation of thermosensitive afferent neurons, thresholds for cold fibers are across a range of cool to cold temperatures that spans over 30 °C. Until recently, how cold produces this myriad of biological effects has been poorly studied, yet new advances in our understanding of cold mechanisms may portend a better understanding of sensory perception as well as provide novel therapeutic approaches. Chief among these was the identification of a number of ion channels that either serve as the initial detectors of cold as a stimulus in the peripheral nervous system, or are part of rather sophisticated differential expression patterns of channels that conduct electrical signals, thereby endowing select neurons with properties that are amenable to electrical signaling in the cold. This review highlights the current understanding of the channels involved in cold transduction as well as presents a hypothetical model to account for the broad range of cold thermal thresholds and distinct functions of cold fibers in perception, pain, and analgesia. PMID:23421674

Predicting worsening asthma control following the common cold

PubMed Central

Walter, Michael J.; Castro, Mario; Kunselman, Susan J.; Chinchilli, Vernon M; Reno, Melissa; Ramkumar, Thiruvamoor P.; Avila, Pedro C.; Boushey, Homer A.; Ameredes, Bill T.; Bleecker, Eugene R.; Calhoun, William J.; Cherniack, Reuben M.; Craig, Timothy J.; Denlinger, Loren C.; Israel, Elliot; Fahy, John V.; Jarjour, Nizar N.; Kraft, Monica; Lazarus, Stephen C.; Lemanske, Robert F.; Martin, Richard J.; Peters, Stephen P.; Ramsdell, Joe W.; Sorkness, Christine A.; Rand Sutherland, E.; Szefler, Stanley J.; Wasserman, Stephen I.; Wechsler, Michael E.

2008-01-01

The asthmatic response to the common cold is highly variable and early characteristics that predict worsening of asthma control following a cold have not been identified. In this prospective multi-center cohort study of 413 adult subjects with asthma, we used the mini-Asthma Control Questionnaire (mini-ACQ) to quantify changes in asthma control and the Wisconsin Upper Respiratory Symptom Survey-21 (WURSS-21) to measure cold severity. Univariate and multivariable models examined demographic, physiologic, serologic, and cold-related characteristics for their relationship to changes in asthma control following a cold. We observed a clinically significant worsening of asthma control following a cold (increase in mini-ACQ of 0.69 ± 0.93). Univariate analysis demonstrated season, center location, cold length, and cold severity measurements all associated with a change in asthma control. Multivariable analysis of the covariates available within the first 2 days of cold onset revealed the day 2 and the cumulative sum of the day 1 and 2 WURSS-21 scores were significant predictors for the subsequent changes in asthma control. In asthmatic subjects the cold severity measured within the first 2 days can be used to predict subsequent changes in asthma control. This information may help clinicians prevent deterioration in asthma control following a cold. PMID:18768579

Review on cold-formed steel connections.

PubMed

Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Tahir, Mahmood Md; Shek, Poi Ngian

2014-01-01

The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.

Evaporative cooling enhanced cold storage system

DOEpatents

Carr, P.

1991-10-15

The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a portion of the added moisture. Preferably at least a portion of the added moisture comprises water condensed during the cooling of the warm air stream. 3 figures.

Review on Cold-Formed Steel Connections

PubMed Central

Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

2014-01-01

The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

Genetics Home Reference: cold-induced sweating syndrome

MedlinePlus

... Health Conditions Cold-induced sweating syndrome Cold-induced sweating syndrome Printable PDF Open All Close All Enable ... view the expand/collapse boxes. Description Cold-induced sweating syndrome is characterized by problems with regulating body ...

Microsolvation of sodium acetate in water: Anion photoelectron spectroscopy and ab initio calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wen-Jing; Hou, Gao-Lei; Wang, Peng

2015-08-07

To understand the microsolvation of sodium acetate (CH{sub 3}COONa, NaOAc) in water, we studied NaOAc(H{sub 2}O){sub n}{sup −} (n = 0–3) clusters by photoelectron spectroscopy. We also investigated the structures of NaOAc(H{sub 2}O){sub n}{sup −} (n = 0–5) anions and NaOAc(H{sub 2}O){sub n} (n = 0–7) neutrals by quantum chemistry calculations. By comparing the theoretical results with the photoelectron experiment, the most probable structures of NaOAc(H{sub 2}O){sub n}{sup −/0} (n = 0–3) were determined. The study also shows that, with increasing n, the solvent-separated ion pair (SSIP) structures of NaOAc(H{sub 2}O){sub n}{sup −} anions become nearly energetically degenerate with themore » contact ion pair (CIP) structures at n = 5, while the SSIP structures of the neutral NaOAc(H{sub 2}O){sub n} clusters appear at n = 6 and become dominant at n = 7.« less

Ambipolar Electric Field, Photoelectrons, and Their Role in Atmospheric Escape From Hot Jupiters

NASA Technical Reports Server (NTRS)

Cohen, O.; Glocer, A.

2012-01-01

Atmospheric mass loss from Hot Jupiters can be large due to the close proximity of these planets to their host star and the strong radiation the planetary atmosphere receives. On Earth, a major contribution to the acceleration of atmospheric ions comes from the vertical separation of ions and electrons, and the generation of the ambipolar electric field. This process, known as the "polar wind," is responsible for the transport of ionospheric constituents to Earth's magnetosphere, where they are well observed. The polar wind can also be enhanced by a relatively small fraction of super-thermal electrons (photoelectrons) generated by photoionization.We formulate a simplified calculation of the effect of the ambipolar electric field and the photoelectrons on the ion scale height in a generalized manner. We find that the ion scale height can be increased by a factor of 2-15 due to the polar wind effects. We also estimate a lower limit of an order of magnitude increase of the ion density and the atmospheric mass-loss rate when polar wind effects are included.

Photo-electron emission directly in superfluid helium

NASA Astrophysics Data System (ADS)

Zavyalov, V. V.; Pyurbeeva, E. B.; Khaldeev, S. I.

2018-03-01

Despite the fact that electron transport in condensed helium has been studied for over half a century [1], observations of new intriguing effects still appear [2]. Alas, the traditional methods of injecting electrons into condensed helium (radioactive-sources, electrical discharge or field emission) lead to generation of helium ions, recombination of which is accompanied by emergence of a large number of excitations. As a result, interpretation of such experiments is not simple and sometimes may be questionable. In this respect, photoelectron emitters, which operate with energies substantially smaller than the ionization energy of helium, are preferable. However, immersion of the photocathode into condensed helium suppresses electron emission. Nevertheless, we managed to achieve electron currents (>20 fA) with the In photocathode immersed directly in liquid superfluid helium. The UV light (λ=254 nm) was guided to the photocathode through a two-meter long Al-covered quartz optical fiber.

Ultra-low dose naltrexone enhances cannabinoid-induced antinociception.

PubMed

Paquette, Jay; Olmstead, Mary C; Olmstead, Mary

2005-12-01

Both opioids and cannabinoids have inhibitory effects at micromolar doses, which are mediated by activated receptors coupling to Gi/o-proteins. Surprisingly, the analgesic effects of opioids are enhanced by ultra-low doses (nanomolar to picomolar) of the opioid antagonist, naltrexone. As opioid and cannabinoid systems interact, this study investigated whether ultra-low dose naltrexone also influences cannabinoid-induced antinociception. Separate groups of Long-Evans rats were tested for antinociception following an injection of vehicle, a sub-maximal dose of the cannabinoid agonist WIN 55 212-2, naltrexone (an ultra-low or a high dose) or a combination of WIN 55 212-2 and naltrexone doses. Tail-flick latencies were recorded for 3 h, at 10-min intervals for the first hour, and at 15-min intervals thereafter. Ultra-low dose naltrexone elevated WIN 55 212-2-induced tail flick thresholds without extending its duration of action. This enhancement was replicated in animals receiving intraperitoneal or intravenous injections. A high dose of naltrexone had no effect on WIN 55 212-2-induced tail flick latencies, but a high dose of the cannabinoid 1 receptor antagonist SR 141716 blocked the elevated tail-flick thresholds produced by WIN 55 212-2+ultra-low dose naltrexone. These data suggest a mechanism of cannabinoid-opioid interaction whereby activated opioid receptors that couple to Gs-proteins may attenuate cannabinoid-induced antinociception and/or motor functioning.

Hydrothermal Cold Sintering

NASA Astrophysics Data System (ADS)

Kang, Xiaoyu

Solid state sintering transforms particle compact to a physically robust and dense polycrystalline monolith driven by reduction of surface energy and curvature. Since bulk diffusion is required for neck formation and pore elimination, sintering temperature about 2/3 of melting point is needed. It thus places limitations for materials synthesis and integration, and contributes to significant energy consumption in ceramic processing. Furthermore, since surface transport requires lower temperature than bulk processes, grain growth is often rapid and can be undesired for physical properties. For these reasons, several techniques have been developed including Liquid Phase Sintering (LPS), Hot Pressing (HP) and Field Assisted Sintering Technique (FAST), which introduce either viscous melt, external pressure or electric field to speed up densification rates at lower temperature. However, because of their inherent reliability on bulk diffusion, temperatures required are often too high for integrating polymers and non-noble metals. Reduction of sintering temperature below 400 °C would require a different densification mechanism that is based on surface transport with external forces to drive volume shrinkage. Densification method combining uniaxial pressure and solution under hydrothermal condition was first demonstrated by Kanahara's group at Kochi University in 1986 and was brought to our attention by the work of Kahari, etc, from University of Oulu on densification of Li2MoO 4 in 2015. This relatively new process showed promising ultra-low densification temperature below 300 °C, however little was known about its fundamental mechanism and scope of applications, which became the main focus of this dissertation. In this work, a uniaxial hydraulic press, a standard stainless steel 1/2 inch diameter die with heating band were utilized in densifying metal oxides. Applied pressure and sintering temperature were between 100 MPa and 700 MPa and from room temperature to 300 �

Impact of cold climates on vehicle emissions: the cold start air toxics pulse : final report.

DOT National Transportation Integrated Search

2016-09-21

This project measured cold start emissions from four vehicles in winter using fast response instrumentation to accurately measure the : time variation of the cold start emission pulse. Seventeen successful tests were conducted over a temperature rang...

COLD-SAT dynamic model

NASA Technical Reports Server (NTRS)

Adams, Neil S.; Bollenbacher, Gary

1992-01-01

This report discusses the development and underlying mathematics of a rigid-body computer model of a proposed cryogenic on-orbit liquid depot storage, acquisition, and transfer spacecraft (COLD-SAT). This model, referred to in this report as the COLD-SAT dynamic model, consists of both a trajectory model and an attitudinal model. All disturbance forces and torques expected to be significant for the actual COLD-SAT spacecraft are modeled to the required degree of accuracy. Control and experimental thrusters are modeled, as well as fluid slosh. The model also computes microgravity disturbance accelerations at any specified point in the spacecraft. The model was developed by using the Boeing EASY5 dynamic analysis package and will run on Apollo, Cray, and other computing platforms.

The effects of ultra-thin cerium fluoride film as the anode buffer layer on the electrical characteristics of organic light emitting diodes

NASA Astrophysics Data System (ADS)

Lu, Hsin-Wei; Tsai, Cheng-Che; Hong, Cheng-Shong; Kao, Po-Ching; Juang, Yung-Der; Chu, Sheng-Yuan

2016-11-01

In this study, the efficiency of organic light-emitting diodes (OLEDs) was enhanced by depositing a CeF3film as an ultra-thin buffer layer between the indium tin oxide (ITO) electrode and α-naphthylphenylbiphenyldiamine (NPB) hole transport layer, with the structure configuration ITO/CeF3 (0.5, 1, and 1.5 nm)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris(8-hydroxyquinoline) aluminum (Alq3) (60 nm)/lithium fluoride (LiF) (1 nm)/Al (150 nm). The enhancement mechanism was systematically investigated via several approaches. The X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy results revealed the formation of the UV-ozone treated CeF3 film. The work function increased from 4.8 eV (standard ITO electrode) to 5.22 eV (0.5-nm-thick UV-ozone treated CeF3 film deposited on the ITO electrode). The surface roughness of the UV-ozone treated CeF3 film was smoother than that of the standard ITO electrode. Further, the UV-ozone treated CeF3 film increased both the surface energy and polarity, as determined from contact angle measurements. In addition, admittance spectroscopy measurements showed an increased capacitance and conductance of the OLEDs. Accordingly, the turn-on voltage decreased from 4.2 V to 3.6 V at 1 mA/cm2, the luminance increased from 7588 cd/m2 to 24760 cd/m2, and the current efficiency increased from 3.2 cd/A to 3.8 cd/A when the 0.5-nm-thick UV-ozone treated CeF3 film was inserted into the OLEDs.

The host galaxies of ultra hard X-ray selected AGN

NASA Astrophysics Data System (ADS)

Koss, Michael J.

One of the great mysteries surrounding active galactic nuclei (AGN) is their triggering mechanism. Since the discovery that almost all massive galaxies host nuclear supermassive black holes, it has become clear that a trigger mechanism is required to 'turn on' and continue to fuel the central black hole. While it is established that accretion processes are responsible for the energy emitted, the source of the accreting material is still controversial. Furthermore, the energy input from phases of black hole growth is thought to be a key regulator in the formation of galaxies and the establishment of various scaling relations. Theorists often invoke galaxy mergers as the violent mechanism to drive gas into the central regions and ignite luminous quasars, but among more common moderate luminosity AGN, there has been great controversy whether secular processes or mergers dominate AGN fueling. A survey in the ultra hard X-ray band (14--195 keV) is an important new way to answer the fundamental question of AGN fueling. This method is independent of selection effects such as dust extinction and obscuration that plague surveys at other wavelengths because of the ability of the primary continuum to easily pass through large columns of obscuring gas and dust (<10 24 cm-2). In this PhD, we have assembled the largest sample of ultra hard X-ray selected AGN with host galaxy optical data to date, with 185 nearby (z<0.05), moderate luminosity AGN from the Swift BAT sample. We find that these AGN show much higher rates of both mergers and massive spirals suggesting both mergers and accretion of cold gas in late type systems are important in AGN fueling. We also find that the most common AGN survey technique, optical line diagnostics, is heavily biased against finding AGN in mergers or spirals. Finally, in agreement with the merger driven AGN link, we find that dual AGN systems may be more common than current observation suggest since some of them are only detected using high

Interpretation of the photoelectron spectra of FeS(2)(-) by a multiconfiguration computational approach.

PubMed

Clima, Sergiu; Hendrickx, Marc F A

2007-11-01

The ground states of FeS(2) and FeS(2)(-), and several low-lying excited electronic states of FeS(2) that are responsible for the FeS(2)(-) photoelectron spectrum, are calculated. At the B3LYP level an open, quasi-linear [SFeS](-) conformation is found as the most stable structure, which is confirmed at the ab initio CASPT2 computational level. Both the neutral and the anionic unsaturated complexes possess high-spin electronic ground states. For the first time a complete assignment of the photoelectron spectrum of FeS(2)(-) is proposed. The lowest energy band in this spectrum is ascribed to an electron detachment from the two highest-lying 3dpi antibonding orbitals (with respect to the iron-sulfur bonding) of iron. The next-lowest experimental band corresponds to an electron removal from nonbonding, nearly pure sulfur orbitals. The two highest bands in the spectra are assigned as electron detachments from pi and sigma bonding mainly sulfur orbitals.

Time-resolved photoelectron spectroscopy of adenosine and adenosine monophosphate photodeactivation dynamics in water microjets

NASA Astrophysics Data System (ADS)

Williams, Holly L.; Erickson, Blake A.; Neumark, Daniel M.

2018-05-01

The excited state relaxation dynamics of adenosine and adenosine monophosphate were studied at multiple excitation energies using femtosecond time-resolved photoelectron spectroscopy in a liquid water microjet. At pump energies of 4.69-4.97 eV, the lowest ππ* excited state, S1, was accessed and its decay dynamics were probed via ionization at 6.20 eV. By reversing the role of the pump and probe lasers, a higher-lying ππ* state was excited at 6.20 eV and its time-evolving photoelectron spectrum was monitored at probe energies of 4.69-4.97 eV. The S1 ππ* excited state was found to decay with a lifetime ranging from ˜210 to 250 fs in adenosine and ˜220 to 250 fs in adenosine monophosphate. This lifetime drops with increasing pump photon energy. Signal from the higher-lying ππ* excited state decayed on a time scale of ˜320 fs and was measureable only in adenosine monophosphate.

Characterization of Polyimide Foams for Ultra-Lightweight Space Structures

NASA Technical Reports Server (NTRS)

Meador, Michael (Technical Monitor); Hillman, Keithan; Veazie, David R.

2003-01-01

Ultra-lightweight materials have played a significant role in nearly every area of human activity ranging from magnetic tapes and artificial organs to atmospheric balloons and space inflatables. The application range of ultra-lightweight materials in past decades has expanded dramatically due to their unsurpassed efficiency in terms of low weight and high compliance properties. A new generation of ultra-lightweight materials involving advanced polymeric materials, such as TEEK (TM) polyimide foams, is beginning to emerge to produce novel performance from ultra-lightweight systems for space applications. As a result, they require that special conditions be fulfilled to ensure adequate structural performance, shape retention, and thermal stability. It is therefore important and essential to develop methodologies for predicting the complex properties of ultra-lightweight foams. To support NASA programs such as the Reusable Launch Vehicle (RLV), Clark Atlanta University, along with SORDAL, Inc., has initiated projects for commercial process development of polyimide foams for the proposed cryogenic tank integrated structure (see figure 1). Fabrication and characterization of high temperature, advanced aerospace-grade polyimide foams and filled foam sandwich composites for specified lifetimes in NASA space applications, as well as quantifying the lifetime of components, are immensely attractive goals. In order to improve the development, durability, safety, and life cycle performance of ultra-lightweight polymeric foams, test methods for the properties are constant concerns in terms of timeliness, reliability, and cost. A major challenge is to identify the mechanisms of failures (i.e., core failure, interfacial debonding, and crack development) that are reflected in the measured properties. The long-term goal of the this research is to develop the tools and capabilities necessary to successfully engineer ultra-lightweight polymeric foams. The desire is to reduce density

Ultra-processed foods and the nutritional dietary profile in Brazil

PubMed Central

Louzada, Maria Laura da Costa; Martins, Ana Paula Bortoletto; Canella, Daniela Silva; Baraldi, Larissa Galastri; Levy, Renata Bertazzi; Claro, Rafael Moreira; Moubarac, Jean-Claude; Cannon, Geoffrey; Monteiro, Carlos Augusto

2015-01-01

OBJECTIVE To assess the impact of consuming ultra-processed foods on the nutritional dietary profile in Brazil. METHODS Cross-sectional study conducted with data from the module on individual food consumption from the 2008-2009 Pesquisa de Orçamentos Familiares (POF – Brazilian Family Budgets Survey). The sample, which represented the section of the Brazilian population aged 10 years or over, involved 32,898 individuals. Food consumption was evaluated by two 24-hour food records. The consumed food items were classified into three groups: natural or minimally processed, including culinary preparations with these foods used as a base; processed; and ultra-processed. RESULTS The average daily energy consumption per capita was 1,866 kcal, with 69.5% being provided by natural or minimally processed foods, 9.0% by processed foods and 21.5% by ultra-processed food. The nutritional profile of the fraction of ultra-processed food consumption showed higher energy density, higher overall fat content, higher saturated and trans fat, higher levels of free sugar and less fiber, protein, sodium and potassium, when compared to the fraction of consumption related to natural or minimally processed foods. Ultra-processed foods presented generally unfavorable characteristics when compared to processed foods. Greater inclusion of ultra-processed foods in the diet resulted in a general deterioration in the dietary nutritional profile. The indicators of the nutritional dietary profile of Brazilians who consumed less ultra-processed foods, with the exception of sodium, are the stratum of the population closer to international recommendations for a healthy diet. CONCLUSIONS The results from this study highlight the damage to health that is arising based on the observed trend in Brazil of replacing traditional meals, based on natural or minimally processed foods, with ultra-processed foods. These results also support the recommendation of avoiding the consumption of these kinds of foods

Ultra-processed foods and the nutritional dietary profile in Brazil.

PubMed

Costa Louzada, Maria Laura da; Martins, Ana Paula Bortoletto; Canella, Daniela Silva; Baraldi, Larissa Galastri; Levy, Renata Bertazzi; Claro, Rafael Moreira; Moubarac, Jean-Claude; Cannon, Geoffrey; Monteiro, Carlos Augusto

2015-01-01

OBJECTIVE To assess the impact of consuming ultra-processed foods on the nutritional dietary profile in Brazil. METHODS Cross-sectional study conducted with data from the module on individual food consumption from the 2008-2009 Pesquisa de Orçamentos Familiares (POF - Brazilian Family Budgets Survey). The sample, which represented the section of the Brazilian population aged 10 years or over, involved 32,898 individuals. Food consumption was evaluated by two 24-hour food records. The consumed food items were classified into three groups: natural or minimally processed, including culinary preparations with these foods used as a base; processed; and ultra-processed. RESULTS The average daily energy consumption per capita was 1,866 kcal, with 69.5% being provided by natural or minimally processed foods, 9.0% by processed foods and 21.5% by ultra-processed food. The nutritional profile of the fraction of ultra-processed food consumption showed higher energy density, higher overall fat content, higher saturated and trans fat, higher levels of free sugar and less fiber, protein, sodium and potassium, when compared to the fraction of consumption related to natural or minimally processed foods. Ultra-processed foods presented generally unfavorable characteristics when compared to processed foods. Greater inclusion of ultra-processed foods in the diet resulted in a general deterioration in the dietary nutritional profile. The indicators of the nutritional dietary profile of Brazilians who consumed less ultra-processed foods, with the exception of sodium, are the stratum of the population closer to international recommendations for a healthy diet. CONCLUSIONS The results from this study highlight the damage to health that is arising based on the observed trend in Brazil of replacing traditional meals, based on natural or minimally processed foods, with ultra-processed foods. These results also support the recommendation of avoiding the consumption of these kinds of foods.

Sweating the small stuff: simulating dwarf galaxies, ultra-faint dwarf galaxies, and their own tiny satellites

NASA Astrophysics Data System (ADS)

Wheeler, Coral Rose

We study dwarf satellite galaxy quenching using observations from the Geha et al. (2012) NSA/SDSS catalog together with CDM cosmological simulations to facilitate selection and interpretation. We show that fewer than 30% of dwarfs (M* ˜ 108.5-9.5 Msun ) identified as satellites within massive host halos (M host ˜ 1012.5-14 Msun) are quenched. We conclude that whatever the action triggering environmental quenching of dwarf satellites, the process must be highly inefficient. We investigate a series of simple, one-parameter quenching models in order to understand what is required to explain the low quenched fraction and conclude that either the quenching timescale is very long (> 9.5 Gyr, a "slow starvation" scenario) or that the environmental trigger is not well matched to accretion within the virial volume. We further present FIRE/Gizmo hydrodynamic zoom-in simulations of isolated dark matter halos, two each at the mass of classical dwarf galaxies (Mvir ˜ 1010 Msun) and ultra-faint galaxies (Mvir ˜ 10 9 Msun). The resulting central galaxies lie on an extrapolated abundance matching relation from M* ˜ 106 to 104 Msun without a break. Our dwarfs with M* ˜ 106 Msun each have 1-2 well-resolved satellites with M* = 3 - 200 x 103 Msun. Even our isolated ultra-faint galaxies have star-forming subhalos. We combine our results with the ELVIS simulations to show that targeting the ˜ 50 kpc regions around nearby isolated dwarfs could increase the chances of discovering ultra-faint galaxies by ˜35% compared to random pointings. The well-resolved ultra-faint galaxies in our simulations (M * ˜ 3 - 30 x 103 Msun) form within Mpeak ˜ 0.5 - 3 x 109 Msun halos. Each has a uniformly ancient stellar population (> 10 Gyr) owing to reionization-related quenching. More massive systems, in contrast, all have late-time star formation. Our results suggest that Mhalo ˜ 5 x 109 Msun is a probable dividing line between halos hosting reionization "fossils" and those hosting dwarfs

Weighing Ultra-Cool Stars

NASA Astrophysics Data System (ADS)

2004-05-01

Large Ground-Based Telescopes and Hubble Team-Up to Perform First Direct Brown Dwarf Mass Measurement [1] Summary Using ESO's Very Large Telescope at Paranal and a suite of ground- and space-based telescopes in a four-year long study, an international team of astronomers has measured for the first time the mass of an ultra-cool star and its companion brown dwarf. The two stars form a binary system and orbit each other in about 10 years. The team obtained high-resolution near-infrared images; on the ground, they defeated the blurring effect of the terrestrial atmosphere by means of adaptive optics techniques. By precisely determining the orbit projected on the sky, the astronomers were able to measure the total mass of the stars. Additional data and comparison with stellar models then yield the mass of each of the components. The heavier of the two stars has a mass around 8.5% of the mass of the Sun and its brown dwarf companion is even lighter, only 6% of the solar mass. Both objects are relatively young with an age of about 500-1,000 million years. These observations represent a decisive step towards the still missing calibration of stellar evolution models for very-low mass stars. PR Photo 19a/04: Orbit of the ultra-cool stars in 2MASSW J0746425+2000321. PR Photo 19b/04: Animated Gif of the orbital motion. Telephone number star Even though astronomers have found several hundreds of very low mass stars and brown dwarfs, the fundamental properties of these extreme objects, such as masses and surface temperatures, are still not well known. Within the cosmic zoo, these ultra-cool stars represent a class of "intermediate" objects between giant planets - like Jupiter - and "normal" stars less massive than our Sun, and to understand them well is therefore crucial to the field of stellar astrophysics. The problem with these ultra-cool stars is that contrary to normal stars that burn hydrogen in their central core, no unique relation exists between the luminosity of the

Peripheral cold acclimatization in Antarctic scuba divers.

PubMed

Bridgman, S A

1991-08-01

Peripheral acclimatization to cold in scuba divers stationed at the British Antarctic Survey's Signy Station was investigated during a year in Antarctica. Five divers and five non-diver controls underwent monthly laboratory tests of index finger immersion in cold water for 30 min. Index finger pulp temperature and time of onset of cold-induced vasodilatation (CIVD) were measured. Pain was recorded with verbal and numerical psychophysical subjective pain ratings. Average finger temperatures and median finger pain from 6-30 min of immersion, maximum finger temperatures during the first CIVD cycle, and finger temperatures at the onset of CIVD were calculated. Comparison of the variables recorded from divers and non-divers were performed with analysis of variance. No significant differences were found among the variables recorded from divers and non-divers. From a review of the literature, divers have responses typical of non-cold-adapted Caucasians. There is, therefore, no evidence that Signy divers peripherally acclimatized to cold. We suggest that these findings occur because either the whole body cooling which divers undergo inhibits peripheral acclimatization or because of insufficiently frequent or severe cold exposure while diving. Further basic studies on the duration, frequency and severity of cold exposure necessary to induce peripheral cold acclimatization are required before this question can be satisfactorily answered.

UltraSail CubeSat Solar Sail Flight Experiment

NASA Technical Reports Server (NTRS)

Carroll, David; Burton, Rodney; Coverstone, Victoria; Swenson, Gary

2013-01-01

UltraSail is a next-generation, highrisk, high-payoff sail system for the launch, deployment, stabilization, and control of very large (km2 class) solar sails enabling high payload mass fractions for interplanetary and deep space spacecraft. UltraSail is a non-traditional approach to propulsion technology achieved by combining propulsion and control systems developed for formation- flying microsatellites with an innovative solar sail architecture to achieve controllable sail areas approaching 1 km2, sail subsystem area densities approaching 1 g/m2, and thrust levels many times those of ion thrusters used for comparable deep space missions. UltraSail can achieve outer planetary rendezvous, a deep-space capability now reserved for high-mass nuclear and chemical systems. There is a twofold rationale behind the UltraSail concept for advanced solar sail systems. The first is that sail-andboom systems are inherently size-limited. The boom mass must be kept small, and column buckling limits the boom length to a few hundred meters. By eliminating the boom, UltraSail not only offers larger sail area, but also lower areal density, allowing larger payloads and shorter mission transit times. The second rationale for UltraSail is that sail films present deployment handling difficulties as the film thickness approaches one micrometer. The square sail requires that the film be folded in two directions for launch, and similarly unfolded for deployment. The film is stressed at the intersection of two folds, and this stress varies inversely with the film thickness. This stress can cause the film to yield, forming a permanent crease, or worse, to perforate. By rolling the film as UltraSail does, creases are prevented. Because the film is so thin, the roll thickness is small. Dynamic structural analysis of UltraSail coupled with dynamic control analysis shows that the system can be designed to eliminate longitudinal torsional waves created while controlling the pitch of the blades

Study of Nb2O(y) (y = 2-5) anion and neutral clusters using anion photoelectron spectroscopy and density functional theory calculations.

PubMed

Mann, Jennifer E; Waller, Sarah E; Rothgeb, David W; Jarrold, Caroline Chick

2011-09-14

A study combining anion photoelectron spectroscopy and density functional theory calculations on the transition metal suboxide series, Nb(2)O(y)(-) (y = 2-5), is described. Photoelectron spectra of the clusters are obtained, and Franck-Condon simulations using calculated anion and neutral structures and frequencies are used to evaluate the calculations and assign transitions observed in the spectra. The spectra, several of which exhibit partially resolved vibrational structure, show an increase in electron affinity with increasing cluster oxidation state. Hole-burning experiments suggest that the photoelectron spectra of both Nb(2)O(2)(-) and Nb(2)O(3)(-) have contributions from more than one structural isomer. Reasonable agreement between experiment and computational results is found among all oxides. © 2011 American Institute of Physics

Social science in the Cold War.

PubMed

Engerman, David C

2010-06-01

This essay examines ways in which American social science in the late twentieth century was--and was not--a creature of the Cold War. It identifies important work by historians that calls into question the assumption that all social science during the Cold War amounts to "Cold War social science." These historians attribute significant agency to social scientists, showing how they were enmeshed in both long-running disciplinary discussions and new institutional environments. Key trends in this scholarship include a broadening historical perspective to see social scientists in the Cold War as responding to the ideas of their scholarly predecessors; identifying the institutional legacies of World War II; and examining in close detail the products of extramural--especially governmental--funding. The result is a view of social science in the Cold War in which national security concerns are relevant, but with varied and often unexpected impacts on intellectual life.

Brain MR imaging at ultra-low radiofrequency power.

PubMed

Sarkar, Subhendra N; Alsop, David C; Madhuranthakam, Ananth J; Busse, Reed F; Robson, Philip M; Rofsky, Neil M; Hackney, David B

2011-05-01

To explore the lower limits for radiofrequency (RF) power-induced specific absorption rate (SAR) achievable at 1.5 T for brain magnetic resonance (MR) imaging without loss of tissue signal or contrast present in high-SAR clinical imaging in order to create a potentially viable MR method at ultra-low RF power to image tissues containing implanted devices. An institutional review board-approved HIPAA-compliant prospective MR study design was used, with written informed consent from all subjects prior to MR sessions. Seven healthy subjects were imaged prospectively at 1.5 T with ultra-low-SAR optimized three-dimensional (3D) fast spin-echo (FSE) and fluid-attenuated inversion-recovery (FLAIR) T2-weighted sequences and an ultra-low-SAR 3D spoiled gradient-recalled acquisition in the steady state T1-weighted sequence. Corresponding high-SAR two-dimensional (2D) clinical sequences were also performed. In addition to qualitative comparisons, absolute signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) for multicoil, parallel imaging acquisitions were generated by using a Monte Carlo method for quantitative comparison between ultra-low-SAR and high-SAR results. There were minor to moderate differences in the absolute tissue SNR and CNR values and in qualitative appearance of brain images obtained by using ultra-low-SAR and high-SAR techniques. High-SAR 2D T2-weighted imaging produced slightly higher SNR, while ultra-low-SAR 3D technique not only produced higher SNR for T1-weighted and FLAIR images but also higher CNRs for all three sequences for most of the brain tissues. The 3D techniques adopted here led to a decrease in the absorbed RF power by two orders of magnitude at 1.5 T, and still the image quality was preserved within clinically acceptable imaging times. RSNA, 2011

Ultra-rapid EOP determination with VLBI

NASA Astrophysics Data System (ADS)

Haas, Rüdiger; Kurihara, Shinobu; Nozawa, Kentaro; Hobiger, Thomas; Lovell, Jim; McCallum, Jamie; Quick, Jonathan

2013-04-01

In 2007 the Geospatial information Authority of Japan (GSI) and the Onsala Space Observatory (OSO) started a project aiming at determining the earth rotation angle, usually expressed as dUT1, in near real-time. In the beginning of this project dedicated one hour long one-baseline experiments were observed periodically using the VLBI stations Onsala (Sweden) and Tsukuba (Japan). The strategy is that the observed VLBI-data are sent in real-time via the international optical fibre backbone to the VLBI-correlator at Tsukuba where the data are correlated and analyzed in near-real time, producing ultra-rapid dUT1 results. An offline version of this strategy has been adopted in 2009 for the regular VLBI intensive series INT-2 involving Wettzell (Germany) and Tsukuba. Since March 2010 the INT-2 is using real-time e-transfer, too, and since June 2010 also automated analysis. Starting in 2009 the ultra-rapid approach was applied to regular 24 hour long VLBI-sessions that involve Tsukuba and Onsala, so that ultra-rapid dUT1 results can be produced already during ongoing VLBI-sessions. This strategy was successfully operated during the 15 days long CONT11 campaign. In 2011 the ultra-rapid strategy was extended to involve a network of VLBI-stations, so that not only dUT1 but also the polar motion components can be determined in near real-time. Initially, in November 2011 a dedicated three-station session was observed involving Onsala, Tsukuba and Hobart (Tasmania, Australia). In 2012 several regular 24 hour long IVS-sessions that involved Onsala, Tsukuba and HartRAO (South Africa) were operated with the ultra-rapid strategy, and in several cases also Hobart was added as a fourth station. For this project we use the new analysis software c5++ developed by the National Institute of Information and Communications Technology (NICT). In this presentation we give an overview of the UREOP-project, describe the recent developments, and discuss the obtained results.

Photoelectron wave function in photoionization: Plane wave or Coulomb wave? [Does photoionization of neutral targets produce Coulomb or plane waves?

DOE PAGES

Gozem, Samer; Gunina, Anastasia O.; Ichino, Takatoshi; ...

2015-10-28

The calculation of absolute total cross sections requires accurate wave functions of the photoelectron and of the initial and final states of the system. The essential information contained in the latter two can be condensed into a Dyson orbital. We employ correlated Dyson orbitals and test approximate treatments of the photoelectron wave function, that is, plane and Coulomb waves, by comparing computed and experimental photoionization and photodetachment spectra. We find that in anions, a plane wave treatment of the photoelectron provides a good description of photodetachment spectra. For photoionization of neutral atoms or molecules with one heavy atom, the photoelectronmore » wave function must be treated as a Coulomb wave to account for the interaction of the photoelectron with the +1 charge of the ionized core. For larger molecules, the best agreement with experiment is often achieved by using a Coulomb wave with a partial (effective) charge smaller than unity. This likely derives from the fact that the effective charge at the centroid of the Dyson orbital, which serves as the origin of the spherical wave expansion, is smaller than the total charge of a polyatomic cation. Finally, the results suggest that accurate molecular photoionization cross sections can be computed with a modified central potential model that accounts for the nonspherical charge distribution of the core by adjusting the charge in the center of the expansion.« less

Low-cost ultra-thin broadband terahertz beam-splitter.

PubMed

Ung, Benjamin S-Y; Fumeaux, Christophe; Lin, Hungyen; Fischer, Bernd M; Ng, Brian W-H; Abbott, Derek

2012-02-27

A low-cost terahertz beam-splitter is fabricated using ultra-thin LDPE plastic sheeting coated with a conducting silver layer. The beam splitting ratio is determined as a function of the thickness of the silver layer--thus any required splitting ratio can be printed on demand with a suitable rapid prototyping technology. The low-cost aspect is a consequence of the fact that ultra-thin LDPE sheeting is readily obtainable, known more commonly as domestic plastic wrap or cling wrap. The proposed beam-splitter has numerous advantages over float zone silicon wafers commonly used within the terahertz frequency range. These advantages include low-cost, ease of handling, ultra-thin thickness, and any required beam splitting ratio can be readily fabricated. Furthermore, as the beam-splitter is ultra-thin, it presents low loss and does not suffer from Fabry-Pérot effects. Measurements performed on manufactured prototypes with different splitting ratios demonstrate a good agreement with our theoretical model in both P and S polarizations, exhibiting nearly frequency-independent splitting ratios in the terahertz frequency range.

Degenerate pressure driven modified nucleus-acoustic waves in degenerate plasmas

NASA Astrophysics Data System (ADS)

Mamun, A. A.

2018-02-01

The existence of degenerate pressure driven modified nucleus-acoustic (DPDMNA) waves propagating in a cold degenerate quantum plasma (DQP) system [containing cold inertialess degenerate electron species (DES), cold inertial non-degenerate light nucleus species (LNS), and stationary heavy nucleus species (HNS)] is predicted for the first time. The DPDMNA waves (in which the mass density of the cold LNS provides the inertia and the cold inertialess DES gives rise to the restoring force) are new since they completely disappear if the degenerate pressure of the cold DES is neglected. It is found that the phase speed (Vp) of the DPDMNA waves decreases with the rise of the charge number density of the stationary HNS for both non-relativistic and ultra-relativistic DES, and that the ultra-relativistic DES does not have any effect on Vp when β = 1, where β = Λc/Λe with Λ e = ne 0 - 1 / 3 being the average inter-electron distance in the DQP system and Λc being the constant (˜10-10 cm) for the DES. However, the ultra-relativistic DES does have quite a significant effect on Vp for β ≫ 1 and β ≪ 1, and the ultra-relativistic effect significantly enhances (reduces) Vp for β ≫ 1 (β ≪ 1). The DPDMNA waves and their dispersion properties are expected to be useful in understanding the basic features of the electrostatic perturbation mode in space and laboratory DQP systems.

Ultra-wide-field imaging in diabetic retinopathy.

PubMed

Ghasemi Falavarjani, Khalil; Tsui, Irena; Sadda, Srinivas R

2017-10-01

Since 1991, 7-field images captured with 30-50 degree cameras in the Early Treatment Diabetic Retinopathy Study were the gold standard for fundus imaging to study diabetic retinopathy. Ultra-wide-field images cover significantly more area (up to 82%) of the fundus and with ocular steering can in many cases image 100% of the fundus ("panretinal"). Recent advances in image analysis of ultra-wide-field imaging allow for precise measurements of the peripheral retinal lesions. There is a growing consensus in the literature that ultra-wide-field imaging improves detection of peripheral lesions in diabetic retinopathy and leads to more accurate classification of the disease. There is discordance among studies, however, on the correlation between peripheral diabetic lesions and diabetic macular edema and optimal management strategies to treat diabetic retinopathy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cold intolerance

MedlinePlus

Some causes of cold intolerance are: Anemia Anorexia nervosa Blood vessel problems, such as Raynaud phenomenon Chronic severe illness General poor health Underactive thyroid ( hypothyroidism ) Problem with the hypothalamus (a part ...

Cold adaptation, aging, and Korean women divers haenyeo.

PubMed

Lee, Joo-Young; Park, Joonhee; Kim, Siyeon

2017-08-08

We have been studying the thermoregulatory responses of Korean breath-hold women divers, called haenyeo, in terms of aging and cold adaptation. During the 1960s to the 1980s, haenyeos received attention from environmental physiologists due to their unique ability to endure cold water while wearing only a thin cotton bathing suit. However, their overall cold-adaptive traits have disappeared since they began to wear wetsuits and research has waned since the 1980s. For social and economic reasons, the number of haenyeos rapidly decreased to 4005 in 2015 from 14,143 in 1970 and the average age of haenyeos is about 75 years old at present. For the past several years, we revisited and explored older haenyeos in terms of environmental physiology, beginning with questionnaire and field studies and later advancing to thermal tolerance tests in conjunction with cutaneous thermal threshold tests in a climate chamber. As control group counterparts, older non-diving females and young non-diving females were compared with older haenyeos in the controlled experiments. Our findings were that older haenyeos still retain local cold tolerance on the extremities despite their aging. Finger cold tests supported more superior local cold tolerance for older haenyeos than for older non-diving females. However, thermal perception in cold reflected aging effects rather than local cold acclimatization. An interesting finding was the possibility of positive cross-adaptation which might be supported by greater heat tolerance and cutaneous warm perception thresholds of older haenyeos who adapted to cold water. It was known that cold-adaptive traits of haenyeos disappeared, but we confirmed that cold-adaptive traits are still retained on the face and hands which could be interpreted by a mode switch to local adaptation from the overall adaptation to cold. Further studies on cross-adaptation between chronic cold stress and heat tolerance are needed.

Transcriptomic characterization of cold acclimation in larval zebrafish

PubMed Central

2013-01-01

Background Temperature is one of key environmental parameters that affect the whole life of fishes and an increasing number of studies have been directed towards understanding the mechanisms of cold acclimation in fish. However, the adaptation of larvae to cold stress and the cold-specific transcriptional alterations in fish larvae remain largely unknown. In this study, we characterized the development of cold-tolerance in zebrafish larvae and investigated the transcriptional profiles under cold stress using RNA-seq. Results Pre-exposure of 96 hpf zebrafish larvae to cold stress (16°C) for 24 h significantly increased their survival rates under severe cold stress (12°C). RNA-seq generated 272 million raw reads from six sequencing libraries and about 92% of the processed reads were mapped to the reference genome of zebrafish. Differential expression analysis identified 1,431 up- and 399 down-regulated genes. Gene ontology enrichment analysis of cold-induced genes revealed that RNA splicing, ribosome biogenesis and protein catabolic process were the most highly overrepresented biological processes. Spliceosome, proteasome, eukaryotic ribosome biogenesis and RNA transport were the most highly enriched pathways for genes up-regulated by cold stress. Moreover, alternative splicing of 197 genes and promoter switching of 64 genes were found to be regulated by cold stress. A shorter isoform of stk16 that lacks 67 amino acids at the N-terminus was specifically generated by skipping the second exon in cold-treated larvae. Alternative promoter usage was detected for per3 gene under cold stress, which leading to a highly up-regulated transcript encoding a truncated protein lacking the C-terminal domains. Conclusions These findings indicate that zebrafish larvae possess the ability to build cold-tolerance under mild low temperature and transcriptional and post-transcriptional regulations are extensively involved in this acclimation process. PMID:24024969

Development of Ultra-high Purity (UHP) Fe-Based Alloys with High Creep and Oxidation Resistance for A-USC Technology

NASA Astrophysics Data System (ADS)

Hamdani, Fethi; Das, Nishith K.; Shoji, Tetsuo

2018-06-01

The design of ultra-high purity (UHP) Fe-based model alloys for advanced ultra-supercritical (A-USC) technology is attempted in this work. Creep testing has been performed in air at 700 °C and a stress level of 150 MPa. Analysis of the fracture surface and cross section of the crept specimen was performed. To evaluate the oxidation resistance in A-USC conditions, oxidation testing was performed in supercritical water (SCW) at 700 °C and 25 MPa. Weight gain (WG) measurements and meticulous characterization of the oxide scale were carried out. Based on thermodynamics and density functional theory calculations, some reactive elements in the Fe-Cr-Ni system were designated to promote precipitation strengthening and to improve the hydrogen-accelerated oxidation resistance. The addition of a 2 wt pct Mo into Fe-22Cr-22Ni-0.6Nb wt pct-based matrix did not significantly improve the creep resistance. The addition of 0.26 wt pct Zr coupled with cold working was effective for improving creep properties. The Mo-modified model alloy showed almost the same WG value as SUS310, while the Zr-modified alloy showed a higher WG value. Meanwhile, a Cr-enriched continuous oxide layer was formed at the oxidation front of the Zr-modified alloy and SUS310S after exposure to SCW conditions.

Development of Ultra-high Purity (UHP) Fe-Based Alloys with High Creep and Oxidation Resistance for A-USC Technology

NASA Astrophysics Data System (ADS)

Hamdani, Fethi; Das, Nishith K.; Shoji, Tetsuo

2018-03-01

The design of ultra-high purity (UHP) Fe-based model alloys for advanced ultra-supercritical (A-USC) technology is attempted in this work. Creep testing has been performed in air at 700 °C and a stress level of 150 MPa. Analysis of the fracture surface and cross section of the crept specimen was performed. To evaluate the oxidation resistance in A-USC conditions, oxidation testing was performed in supercritical water (SCW) at 700 °C and 25 MPa. Weight gain (WG) measurements and meticulous characterization of the oxide scale were carried out. Based on thermodynamics and density functional theory calculations, some reactive elements in the Fe-Cr-Ni system were designated to promote precipitation strengthening and to improve the hydrogen-accelerated oxidation resistance. The addition of a 2 wt pct Mo into Fe-22Cr-22Ni-0.6Nb wt pct-based matrix did not significantly improve the creep resistance. The addition of 0.26 wt pct Zr coupled with cold working was effective for improving creep properties. The Mo-modified model alloy showed almost the same WG value as SUS310, while the Zr-modified alloy showed a higher WG value. Meanwhile, a Cr-enriched continuous oxide layer was formed at the oxidation front of the Zr-modified alloy and SUS310S after exposure to SCW conditions.

Ultra-high Temperature Emittance Measurements for Space and Missile Applications

NASA Technical Reports Server (NTRS)

Rogers, Jan; Crandall, David

2009-01-01

Advanced modeling and design efforts for many aerospace components require high temperature emittance data. Applications requiring emittance data include propulsion systems, radiators, aeroshells, heatshields/thermal protection systems, and leading edge surfaces. The objective of this work is to provide emittance data at ultra-high temperatures. MSFC has a new instrument for the measurement of emittance at ultra-high temperatures, the Ultra-High Temperature Emissometer System (Ultra-HITEMS). AZ Technology Inc. developed the instrument, designed to provide emittance measurements over the temperature range 700-3500K. The Ultra-HITEMS instrument measures the emittance of samples, heated by lasers, in vacuum, using a blackbody source and a Fourier Transform Spectrometer. Detectors in a Nicolet 6700 FT-IR spectrometer measure emittance over the spectral range of 0.4-25 microns. Emitted energy from the specimen and output from a Mikron M390S blackbody source at the same temperature with matched collection geometry are measured. Integrating emittance over the spectral range yields the total emittance. The ratio provides a direct measure of total hemispherical emittance. Samples are heated using lasers. Optical pyrometry provides temperature data. Optical filters prevent interference from the heating lasers. Data for Inconel 718 show excellent agreement with results from literature and ASTM 835. Measurements taken from levitated spherical specimens provide total hemispherical emittance data; measurements taken from flat specimens mounted in the chamber provide near-normal emittance data. Data from selected characterization studies will be presented. The Ultra-HITEMS technique could advance space and missile technologies by advancing the knowledge base and the technology readiness level for ultra-high temperature materials.

Ultra-low noise supercontinuum source for ultra-high resolution optical coherence tomography at 1300 nm

NASA Astrophysics Data System (ADS)

Gonzalo, I. B.; Maria, M.; Engelsholm, R. D.; Feuchter, T.; Leick, L.; Moselund, P. M.; Podoleanu, A.; Bang, O.

2018-02-01

Supercontinuum (SC) sources are of great interest for many applications due to their ultra-broad optical bandwidth, good beam quality and high power spectral density [1]. In particular, the high average power over large bandwidths makes SC light sources excellent candidates for ultra-high resolution optical coherence tomography (UHR-OCT) [2-5]. However, conventional SC sources suffer from high pulse-to-pulse intensity fluctuations as a result of the noise-sensitive nonlinear effects involved in the SC generation process [6-9]. This intensity noise from the SC source can limit the performance of OCT, resulting in a reduced signal-to-noise ratio (SNR) [10-12]. Much work has been done to reduce the noise of the SC sources for instance with fiber tapers [7,8] or increasing the repetition rate of the pump laser for averaging in the spectrometer [10,12]. An alternative approach is to use all-normal dispersion (ANDi) fibers [13,14] to generate SC light from well-known coherent nonlinear processes [15-17]. In fact, reduction of SC noise using ANDi fibers compared to anomalous dispersion SC pumped by sub-picosecond pulses has been recently demonstrated [18], but a cladding mode was used to stabilize the ANDi SC. In this work, we characterize the noise performance of a femtosecond pumped ANDi based SC and a commercial SC source in an UHR-OCT system at 1300 nm. We show that the ANDi based SC presents exceptional noise properties compared to a commercial source. An improvement of 5 dB in SNR is measured in the UHR-OCT system, and the noise behavior resembles that of a superluminiscent diode. This preliminary study is a step forward towards development of an ultra-low noise SC source at 1300 nm for ultra-high resolution OCT.

Solar University-National Lab Ultra-Effective Program | Photovoltaic

Science.gov Websites

Lab Ultra-Effective Program Solar University-National lab Ultra-effective Program (SUN UP) was created scientists arise out of long-standing collaborations. SUN UP was created to facilitate these interactions of a young man working in a laboratory setting with equipment. The goal of SUN UP is to increase the

Determination of the absolute carrier-envelope phase by angle-resolved photoelectron spectra of Ar by intense circularly polarized few-cycle pulses

NASA Astrophysics Data System (ADS)

Fukahori, Shinichi; Ando, Toshiaki; Miura, Shun; Kanya, Reika; Yamanouchi, Kaoru; Rathje, Tim; Paulus, Gerhard G.

2017-05-01

The angle-resolved photoelectron spectra of Ar are recorded using intense circularly polarized near-infrared few-cycle laser pulses, and the effect of the depletion of Ar atoms by the ionization and the effect of the Coulombic potential are examined by the classical trajectory Monte Carlo simulations. On the basis of the comparison between the experimental and theoretical photoelectron spectra, a procedure for estimating the absolute carrier-envelope phase (CEP) of the few-cycle laser pulses interacting with atoms and molecules is proposed. It is confirmed that the absolute CEP can securely be estimated without any numerical calculations once the angular distribution of the yield of photoelectrons having the kinetic energy larger than 30 eV is measured with the peak laser intensity in the range between 1 ×1014 and 5 ×1014W /c m2 .

Ultra-fast switching of light by absorption saturation in vacuum ultra-violet region.

PubMed

Yoneda, Hitoki; Inubushi, Yuichi; Tanaka, Toshihiro; Yamaguchi, Yuta; Sato, Fumiya; Morimoto, Shunsuke; Kumagai, Taisuke; Nagasono, Mitsuru; Higashiya, Atsushi; Yabashi, Makina; Ishikawa, Tetsuya; Ohashi, Haruhiko; Kimura, Hiroaki; Kitamura, Hikaru; Kodama, Ryosuke

2009-12-21

Advances in free electron lasers producing high energy photons [Nat. Photonics 2(9), 555-559 (2008)] are expected to open up a new science of nonlinear optics of high energy photons. Specifically, lasers of photon energy higher than the plasma frequency of a metal can show new interaction features because they can penetrate deeply into metals without strong reflection. Here we show the observation of ultra-fast switching of vacuum ultra-violet (VUV) light caused by saturable absorption of a solid metal target. A strong gating is observed at energy fluences above 6J/cm2 at wavelength of 51 nm with tin metal thin layers. The ratio of the transmission at high intensity to low intensity is typically greater than 100:1. This means we can design new nonlinear photonic devices such as auto-correlator and pulse slicer for the VUV region.

Early Cold-Induced Peroxidases and Aquaporins Are Associated With High Cold Tolerance in Dajiao (Musa spp. ‘Dajiao’)

PubMed Central

He, Wei-Di; Gao, Jie; Dou, Tong-Xin; Shao, Xiu-Hong; Bi, Fang-Cheng; Sheng, Ou; Deng, Gui-Ming; Li, Chun-Yu; Hu, Chun-Hua; Liu, Ji-Hong; Zhang, Sheng; Yang, Qiao-Song; Yi, Gan-Jun

2018-01-01

Banana is an important tropical fruit with high economic value. One of the main cultivars (‘Cavendish’) is susceptible to low temperatures, while another closely related specie (‘Dajiao’) has considerably higher cold tolerance. We previously reported that some membrane proteins appear to be involved in the cold tolerance of Dajiao bananas via an antioxidation mechanism. To investigate the early cold stress response of Dajiao, here we applied comparative membrane proteomics analysis for both cold-sensitive Cavendish and cold-tolerant Dajiao bananas subjected to cold stress at 10°C for 0, 3, and 6 h. A total of 2,333 and 1,834 proteins were identified in Cavendish and Dajiao, respectively. Subsequent bioinformatics analyses showed that 692 Cavendish proteins and 524 Dajiao proteins were predicted to be membrane proteins, of which 82 and 137 differentially abundant membrane proteins (DAMPs) were found in Cavendish and Dajiao, respectively. Interestingly, the number of DAMPs with increased abundance following 3 h of cold treatment in Dajiao (80) was seven times more than that in Cavendish (11). Gene ontology molecular function analysis of DAMPs for Cavendish and Dajiao indicated that they belong to eight categories including hydrolase activity, binding, transporter activity, antioxidant activity, etc., but the number in Dajiao is twice that in Cavendish. Strikingly, we found peroxidases (PODs) and aquaporins among the protein groups whose abundance was significantly increased after 3 h of cold treatment in Dajiao. Some of the PODs and aquaporins were verified by reverse-transcription PCR, multiple reaction monitoring, and green fluorescent protein-based subcellular localization analysis, demonstrating that the global membrane proteomics data are reliable. By combining the physiological and biochemical data, we found that membrane-bound Peroxidase 52 and Peroxidase P7, and aquaporins (MaPIP1;1, MaPIP1;2, MaPIP2;4, MaPIP2;6, MaTIP1;3) are mainly involved in

Actively controlling coolant-cooled cold plate configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chainer, Timothy J.; Parida, Pritish R.

A method is provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The method includes: monitoring a variable associated with at least one of the coolant-cooled cold plate or one or more electronic components being cooled by the cold plate; and dynamically varying, based on the monitored variable, a physical configuration of the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the one or more electronic components, and at the same time, reduce cooling power consumptionmore » used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the coolant-cooled cold plate, the positioning of which may be adjusted based on the monitored variable.« less

Added sugars and ultra-processed foods in Spanish households (1990-2010).

PubMed

Latasa, P; Louzada, M L D C; Martinez Steele, E; Monteiro, C A

2017-12-26

To study the association between ultra-processed foods acquisitions and added sugar content of total food purchases in Spanish households in 2010. Changes over time (1990-2000-2010) in ultra-processed food purchases and added sugars content of total food purchases are also compared. We used data from three nationally representative Household Budget Surveys (HBS) conducted in 1990, 2000 and 2010. Number of studied households was 21,012, 33,730 and 22,116, respectively. Purchased foods and drinks were classified according to NOVA food groups as ultra-processed foods, processed foods, unprocessed or minimally processed foods, or processed culinary ingredients. Linear and Poisson regressions were used to estimate the association between quintiles of energy contribution of ultra-processed foods and added sugars contents of total food purchases in 2010. Changes over time were assessed using tests of linear trend and Student's t test. In 2010, ultra-processed foods represented 31.7% of daily energy acquisitions and 80.4% of all added sugars. Added sugars content of food purchases raised from 7.3% in the lowest to 18.2% in the highest quintiles of energy contribution of ultra-processed foods. The risk of exceeding 10% energy from added sugars quadrupled between the lowest and highest quintiles. The percentage of ultra-processed foods on all food purchases almost tripled between 1990 and 2010 (from 11.0 to 31.7%), paralleling the increase of added sugars content (from 8.4 to 13.0%). Cutting down exceeding added sugars availability in Spain may require a reduction in ultra-processed food purchasing.

Global search in photoelectron diffraction structure determination using genetic algorithms

NASA Astrophysics Data System (ADS)

Viana, M. L.; Díez Muiño, R.; Soares, E. A.; Van Hove, M. A.; de Carvalho, V. E.

2007-11-01

Photoelectron diffraction (PED) is an experimental technique widely used to perform structural determinations of solid surfaces. Similarly to low-energy electron diffraction (LEED), structural determination by PED requires a fitting procedure between the experimental intensities and theoretical results obtained through simulations. Multiple scattering has been shown to be an effective approach for making such simulations. The quality of the fit can be quantified through the so-called R-factor. Therefore, the fitting procedure is, indeed, an R-factor minimization problem. However, the topography of the R-factor as a function of the structural and non-structural surface parameters to be determined is complex, and the task of finding the global minimum becomes tough, particularly for complex structures in which many parameters have to be adjusted. In this work we investigate the applicability of the genetic algorithm (GA) global optimization method to this problem. The GA is based on the evolution of species, and makes use of concepts such as crossover, elitism and mutation to perform the search. We show results of its application in the structural determination of three different systems: the Cu(111) surface through the use of energy-scanned experimental curves; the Ag(110)-c(2 × 2)-Sb system, in which a theory-theory fit was performed; and the Ag(111) surface for which angle-scanned experimental curves were used. We conclude that the GA is a highly efficient method to search for global minima in the optimization of the parameters that best fit the experimental photoelectron diffraction intensities to the theoretical ones.

Monitoring the vaccine cold chain.

PubMed

Cheriyan, E

1993-11-01

Maintaining the vaccine cold chain is an essential part of a successful immunisation programme. A continuous electronic temperature monitor helped to identify breaks in the cold chain in the community and the study led to the issue of proper guidelines and replacement of faulty equipment.

Frequent Extreme Cold Exposure and Brown Fat and Cold-Induced Thermogenesis: A Study in a Monozygotic Twin

PubMed Central

Vosselman, Maarten J.; Vijgen, Guy H. E. J.; Kingma, Boris R. M.; Brans, Boudewijn; van Marken Lichtenbelt, Wouter D.

2014-01-01

Introduction Mild cold acclimation is known to increase brown adipose tissue (BAT) activity and cold-induced thermogenesis (CIT) in humans. We here tested the effect of a lifestyle with frequent exposure to extreme cold on BAT and CIT in a Dutch man known as ‘the Iceman’, who has multiple world records in withstanding extreme cold challenges. Furthermore, his monozygotic twin brother who has a ‘normal’ sedentary lifestyle without extreme cold exposures was measured. Methods The Iceman (subject A) and his brother (subject B) were studied during mild cold (13°C) and thermoneutral conditions (31°C). Measurements included BAT activity and respiratory muscle activity by [18F]FDG-PET/CT imaging and energy expenditure through indirect calorimetry. In addition, body temperatures, cardiovascular parameters, skin perfusion, and thermal sensation and comfort were measured. Finally, we determined polymorphisms for uncoupling protein-1 and β3-adrenergic receptor. Results Subjects had comparable BAT activity (A: 1144 SUVtotal and B: 1325 SUVtotal), within the range previously observed in young adult men. They were genotyped with the polymorphism for uncoupling protein-1 (G/G). CIT was relatively high (A: 40.1% and B: 41.9%), but unlike during our previous cold exposure tests in young adult men, here both subjects practiced a g-Tummo like breathing technique, which involves vigorous respiratory muscle activity. This was confirmed by high [18F]FDG-uptake in respiratory muscle. Conclusion No significant differences were found between the two subjects, indicating that a lifestyle with frequent exposures to extreme cold does not seem to affect BAT activity and CIT. In both subjects, BAT was not higher compared to earlier observations, whereas CIT was very high, suggesting that g-Tummo like breathing during cold exposure may cause additional heat production by vigorous isometric respiratory muscle contraction. The results must be interpreted with caution given the low

How cold pool triggers deep convection?

NASA Astrophysics Data System (ADS)

Yano, Jun-Ichi

2014-05-01

The cold pool in the boundary layer is often considered a major triggering mechanism of convection. Here, presented are basic theoretical considerations on this issue. Observations suggest that cold pool-generated convective cells is available for shallow maritime convection (Warner et al. 1979; Zuidema et al. 2012), maritime deep convection (Barnes and Garstang 1982; Addis et al. 1984; Young et al. 1995) and continental deep convection (e.g., Lima and Wilson 2008; Flamant 2009; Lothon et al. 2011; Dione et al. 2013). Moreover, numerical studies appear to suggest that cold pools promote the organization of clouds into larger structures and thereby aid the transition from shallow to deep convection (Khairoutdinov and Randall 2006, Boing et al. 2012, Schlemmer and Hohenegger, 2014). Even a cold--pool parameterization coupled with convection is already proposed (Grandpeix and Lafore 2010: but see also Yano 2012). However, the suggested link between the cold pool and deep convection so far is phenomenological at the best. A specific process that the cold pool leads to a trigger of deep convection must still to be pinned down. Naively, one may imagine that a cold pool lifts up the air at the front as it propagates. Such an uplifting leads to a trigger of convection. However, one must realize that a shift of air along with its propagation does not necessarily lead to an uplifting, and even if it may happen, it would not far exceed a depth of the cold pool itself. Thus, the uplifting can never be anything vigorous. Its thermodynamic characteristics do help much either for inducing convection. The cold-pool air is rather under rapid recovering process before it can induce convection under a simple parcel-lifting argument. The most likely reason that the cold pool may induce convection is its gust winds that may encounter an air mass from an opposite direction. This induces a strong convergence, also leading to a strong uplifting. This is an argument essentially developed

Experiences issues with plastic parts at cold temperatures

NASA Technical Reports Server (NTRS)

Sandor, Mike; Agarwal, Shri

2005-01-01

Missions to MARS/planets/asteroids require electronic parts to operate and survive at extreme cold conditions. At extreme cold temperatures many types of cold related failures can occur. Office 514 is currently evaluating plastic parts under various cold temperature conditions and applications. Evaluations, screens, and qualifications are conducted on flight parts.

Cutaneous microvascular response during local cold exposure - the effect of female sex hormones and cold perception.

PubMed

Cankar, Ksenija; Music, Mark; Finderle, Zare

2016-11-01

It is generally known that differences exist between males and females with regard to sensitivity to cold. Similar differences even among females in different hormonal balance might influence microvascular response during cold provocation testing. The aim of the present study was to measure sex hormone levels, cold and cold pain perception thresholds and compare them to cutaneous laser-Doppler flux response during local cooling in both the follicular and luteal phases of the menstrual cycle. In the luteal phase a more pronounced decrease in laser-Doppler flux was observed compared to follicular phase during local cooling at 15°C (significant difference by Dunnett's test, p<0.05). In addition, statistically significant correlations between progesterone level and laser-Doppler flux response to local cooling were observed during the follicular (R=-0.552, p=0.0174) and during the luteal phases (R=0.520, p=0.0271). In contrast, the correlation between estradiol level and laser-Doppler flux response was observed only in the follicular phase (R=-0.506, p=0.0324). Our results show that individual sensitivity to cold influences cutaneous microvascular response to local cooling; that microvascular reactivity is more pronounced during the luteal phase of the menstrual cycle; and that reactivity correlates with hormone levels. The effect of specific sex hormone levels is related to the cold-provocation temperature. Copyright © 2016. Published by Elsevier Inc.

Nonfreezing Cold-Induced Injuries

DTIC Science & Technology

2012-01-01

cold injury. ( Modi - fi ed from Jia J, Pollock M: The pathogenesis of non-freezing cold nerve injury: Observations in the rat, Brain 120:631, 1997...myelitis and sinus development ( Figures 7-17 to 7-19 ). Appearance and behavior of the neuropathic foot have many similarities to those of the diabetic ...foot. In the diabetic foot, infections tend to be polymicrobial with Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus and

CFRP composite optical telescope assembly for the 1 m ULTRA project

NASA Astrophysics Data System (ADS)

Martin, Robert N.; Romeo, Robert C.

2006-06-01

The focus of the ULTRA Project is to develop and test Ultra-Lightweight Technology for Research applications in Astronomy. The ULTRA project is a collaborative effort involving the private firm Composite Mirror Applications, Inc (CMA) and 3 universities: University of Kansas, San Diego State University, and Dartmouth College. Funding for ULTRA is predominately from a NSF three year MRI program grant to CMA and KU with additional support from CMA, KU and SDSU. The goal of the ULTRA program is to demonstrate that a viable alternative exists to traditional glass mirror and steel telescope technology by designing, fabricating and testing a research telescope constructed from carbon fiber reinforced plastic (CFRP) materials. In particular, a 1m diameter, Cassegrain telescope optics set and optical tube assembly (OTA) are being designed and fabricated by CMA. The completed telescope will be deployed at SDSU's Mt Laguna Observatory in a refurbished structure (new dome and mount provided via KU and SDSU). We expect that a successful completion and testing of this project will lead to future use of CFRP technology in larger telescopes and segmented telescopes. This paper describes the OTA (optical tube assembly) that has been developed for the ULTRA project. The mirror technology is described in another paper in this conference. A poster describes the ULTRA project overview in more detail.

The time-resolved photoelectron spectrum of toluene using a perturbation theory approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richings, Gareth W.; Worth, Graham A., E-mail: g.a.worth@bham.ac.uk

A theoretical study of the intra-molecular vibrational-energy redistribution of toluene using time-resolved photo-electron spectra calculated using nuclear quantum dynamics and a simple, two-mode model is presented. Calculations have been carried out using the multi-configuration time-dependent Hartree method, using three levels of approximation for the calculation of the spectra. The first is a full quantum dynamics simulation with a discretisation of the continuum wavefunction of the ejected electron, whilst the second uses first-order perturbation theory to calculate the wavefunction of the ion. Both methods rely on the explicit inclusion of both the pump and probe laser pulses. The third method includesmore » only the pump pulse and generates the photo-electron spectrum by projection of the pumped wavepacket onto the ion potential energy surface, followed by evaluation of the Fourier transform of the autocorrelation function of the subsequently propagated wavepacket. The calculations performed have been used to study the periodic population flow between the 6a and 10b16b modes in the S{sub 1} excited state, and compared to recent experimental data. We obtain results in excellent agreement with the experiment and note the efficiency of the perturbation method.« less

A novel cold-regulated gene, COR25, of Brassica napus is involved in plant response and tolerance to cold stress.

PubMed

Chen, Liang; Zhong, Hui; Ren, Feng; Guo, Qian-Qian; Hu, Xu-Peng; Li, Xue-Bao

2011-04-01

Cold stress, which causes dehydration damage to the plant cell, is one of the most common abiotic stresses that adversely affect plant growth and crop productivity. To improve its cold-tolerance, plants often enhance expression of some cold-related genes. In this study, a cold-regulated gene encoding 25 KDa of protein was isolated from Brassica napus cDNA library using a macroarray analysis, and is consequently designated as BnCOR25. RT-PCR analysis demonstrated that BnCOR25 was expressed at high levels in hypocotyls, cotyledons, stems, and flowers, but its mRNA was found at low levels in roots and leaves. Northern blot analysis revealed that BnCOR25 transcripts were significantly induced by cold and osmotic stress treatment. The data also showed that BnCOR25 gene expression is mediated by ABA-dependent pathway. Overexpression of BnCOR25 in yeast (Schizosaccharomyces pombe) significantly enhanced the cell survival probability under cold stress, and overexpression of BnCOR25 in Arabidopsis enhances plant tolerance to cold stress. These results suggested that the BnCOR25 gene may play an important role in conferring freezing/cold tolerance in plants.

San Juan Ultra (Mooklabs)

Science.gov Websites

de Información Formulario para la solicitud de datos e información relevantes a las investigaciones Science Foundation under Grant No. 0948507." back up ↑ © Copyright 2018 San Juan Ultra (Mooklabs

Cold-induced retrotransposition of fish LINEs.

PubMed

Chen, Shue; Yu, Mengchao; Chu, Xu; Li, Wenhao; Yin, Xiujuan; Chen, Liangbiao

2017-08-20

Classes of retrotransposons constitute a large portion of metazoan genome. There have been cases reported that genomic abundance of retrotransposons is correlated with the severity of low environmental temperatures. However, the molecular mechanisms underlying such correlation are unknown. We show here by cell transfection assays that retrotransposition (RTP) of a long interspersed nuclear element (LINE) from an Antarctic notothenioid fish Dissostichus mawsoni (dmL1) could be activated by low temperature exposure, causing increased dmL1 copies in the host cell genome. The cold-induced dmL1 propagation was demonstrated to be mediated by the mitogen-activated protein kinases (MAPK)/p38 signaling pathway, which is activated by accumulation of reactive oxygen species (ROS) in cold-stressed conditions. Surprisingly, dmL1 transfected cells showed an increase in the number of viable cells after prolonged cold exposures than non-transfected cells. Features of cold inducibility of dmL1 were recapitulated in LINEs of zebrafish origin both in cultured cell lines and tissues, suggesting existence of a common cold-induced LINE amplification in fishes. The findings reveal an important function of LINEs in temperature adaptation and provid insights into the MAPK/p38 stress responsive pathway that shapes LINE composition in fishes facing cold stresses. Copyright © 2017. Published by Elsevier Ltd.

Ultra violet disinfection: A 3-year history

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tubesing, R.R.; Lindeke, D.R.

1998-07-01

The Stillwater Wastewater Treatment Facility is one of nine wastewater treatment facilities operated by the Metropolitan Council Environmental Services in the Minneapolis-St. Paul Metropolitan Area. The facility services the cities of Stillwater, Oak Park Heights, and Bayport. In 1993, an ultra violet disinfection facility began operation to provide the disinfection for the Facility. This presentation discusses the reasons for using ultra violet disinfection in lieu of chlorination/dechlorination facilities, the operating performance, and operating cost factors.

The 'warm' side of coldness: Cold promotes interpersonal warmth in negative contexts.

PubMed

Wei, Wenqi; Ma, Jingjing; Wang, Lei

2015-12-01

The concrete experience of physical warmth has been demonstrated to promote interpersonal warmth. This well-documented link, however, tells only half of the story. In the current study, we thus examined whether physical coldness can also increase interpersonal warmth under certain circumstances. We conducted three experiments to demonstrate that the relationship between the experience of physical temperature and interpersonal outcomes is context dependent. Experiment 1 showed that participants touching cold (vs. warm) objects were more willing to forgive a peer's dishonest behaviour. Experiment 2 demonstrated the fully interactive effect of temperature and context on interpersonal warmth: Participants touching cold (vs. warm) objects were less likely to assist an individual who had provided them with good service (positive social context), but more likely to assist an individual who had provided them with poor service (negative social context). Experiment 3 replicated the results of Experiment 2 using the likelihood to complain, a hostility-related indicator, as the dependent variable: In a pleasant queue (positive social context), participants touching cold objects were more likely to complain and those touching warm objects were less likely to complain compared with the control group. This pattern was reversed in an annoying queue (negative social context). © 2015 The Authors. British Journal of Social Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

Comparison of ultra-widefield fluorescein angiography with the Heidelberg Spectralis® noncontact ultra-widefield module versus the Optos® Optomap®

PubMed Central

Witmer, Matthew T; Parlitsis, George; Patel, Sarju; Kiss, Szilárd

2013-01-01

Purpose To compare ultra-widefield fluorescein angiography imaging using the Optos® Optomap® and the Heidelberg Spectralis® noncontact ultra-widefield module. Methods Five patients (ten eyes) underwent ultra-widefield fluorescein angiography using the Optos® panoramic P200Tx imaging system and the noncontact ultra-widefield module in the Heidelberg Spectralis® HRA+OCT system. The images were obtained as a single, nonsteered shot centered on the macula. The area of imaged retina was outlined and quantified using Adobe® Photoshop® C5 software. The total area and area within each of four visualized quadrants was calculated and compared between the two imaging modalities. Three masked reviewers also evaluated each quadrant per eye (40 total quadrants) to determine which modality imaged the retinal vasculature most peripherally. Results Optos® imaging captured a total retinal area averaging 151,362 pixels, ranging from 116,998 to 205,833 pixels, while the area captured using the Heidelberg Spectralis® was 101,786 pixels, ranging from 73,424 to 116,319 (P = 0.0002). The average area per individual quadrant imaged by Optos® versus the Heidelberg Spectralis® superiorly was 32,373 vs 32,789 pixels, respectively (P = 0.91), inferiorly was 24,665 vs 26,117 pixels, respectively (P = 0.71), temporally was 47,948 vs 20,645 pixels, respectively (P = 0.0001), and nasally was 46,374 vs 22,234 pixels, respectively (P = 0.0001). The Heidelberg Spectralis® was able to image the superior and inferior retinal vasculature to a more distal point than was the Optos®, in nine of ten eyes (18 of 20 quadrants). The Optos® was able to image the nasal and temporal retinal vasculature to a more distal point than was the Heidelberg Spectralis®, in ten of ten eyes (20 of 20 quadrants). Conclusion The ultra-widefield fluorescein angiography obtained with the Optos® and Heidelberg Spectralis® ultra-widefield imaging systems are both excellent modalities that provide views of the

Comparison of ultra-widefield fluorescein angiography with the Heidelberg Spectralis(®) noncontact ultra-widefield module versus the Optos(®) Optomap(®).

PubMed

Witmer, Matthew T; Parlitsis, George; Patel, Sarju; Kiss, Szilárd

2013-01-01

To compare ultra-widefield fluorescein angiography imaging using the Optos(®) Optomap(®) and the Heidelberg Spectralis(®) noncontact ultra-widefield module. Five patients (ten eyes) underwent ultra-widefield fluorescein angiography using the Optos(®) panoramic P200Tx imaging system and the noncontact ultra-widefield module in the Heidelberg Spectralis(®) HRA+OCT system. The images were obtained as a single, nonsteered shot centered on the macula. The area of imaged retina was outlined and quantified using Adobe(®) Photoshop(®) C5 software. The total area and area within each of four visualized quadrants was calculated and compared between the two imaging modalities. Three masked reviewers also evaluated each quadrant per eye (40 total quadrants) to determine which modality imaged the retinal vasculature most peripherally. Optos(®) imaging captured a total retinal area averaging 151,362 pixels, ranging from 116,998 to 205,833 pixels, while the area captured using the Heidelberg Spectralis(®) was 101,786 pixels, ranging from 73,424 to 116,319 (P = 0.0002). The average area per individual quadrant imaged by Optos(®) versus the Heidelberg Spectralis(®) superiorly was 32,373 vs 32,789 pixels, respectively (P = 0.91), inferiorly was 24,665 vs 26,117 pixels, respectively (P = 0.71), temporally was 47,948 vs 20,645 pixels, respectively (P = 0.0001), and nasally was 46,374 vs 22,234 pixels, respectively (P = 0.0001). The Heidelberg Spectralis(®) was able to image the superior and inferior retinal vasculature to a more distal point than was the Optos(®), in nine of ten eyes (18 of 20 quadrants). The Optos(®) was able to image the nasal and temporal retinal vasculature to a more distal point than was the Heidelberg Spectralis(®), in ten of ten eyes (20 of 20 quadrants). The ultra-widefield fluorescein angiography obtained with the Optos(®) and Heidelberg Spectralis(®) ultra-widefield imaging systems are both excellent modalities that provide views of the

A pulse tube cryocooler with a cold reservoir

NASA Astrophysics Data System (ADS)

Zhang, X. B.; Zhang, K. H.; Qiu, L. M.; Gan, Z. H.; Shen, X.; Xiang, S. J.

2013-02-01

Phase difference between pressure wave and mass flow is decisive to the cooling capacity of regenerative cryocoolers. Unlike the direct phase shifting using a piston or displacer in conventional Stirling or GM cryocoolers, the pulse tube cyocooler (PTC) indirectly adjusts the cold phase due to the absence of moving parts at the cold end. The present paper proposed and validated theoretically and experimentally a novel configuration of PTC, termed cold reservoir PTC, in which a reservoir together with an adjustable orifice is connected to the cold end of the pulse tube. The impedance from the additional orifice to the cold end helps to increase the mass flow in phase with the pressure wave at the cold end. Theoretical analyses with the linear model for the orifice and double-inlet PTCs indicate that the cooling performance can be improved by introducing the cold reservoir. The preliminary experiments with a home-made single-stage GM PTC further validated the results on the premise of minor opening of the cold-end orifice.

Feasibility and clinical utility of ultra-widefield indocyanine green angiography.

PubMed

Klufas, Michael A; Yannuzzi, Nicolas A; Pang, Claudine E; Srinivas, Sowmya; Sadda, Srinivas R; Freund, K Bailey; Kiss, Szilárd

2015-03-01

To evaluate the feasibility and clinical utility of a novel noncontact scanning laser ophthalmoscope-based ultra-widefield indocyanine green angiographic system. Ultra-widefield indocyanine green angiographic images were captured using a modified Optos P200Tx that produced high-resolution images of the choroidal vasculature with up to a 200° field. Ultra-widefield indocyanine green angiography was performed on patients with a variety of retinal conditions to assess utility of this imaging technique for diagnostic purposes and disease treatment monitoring. Ultra-widefield indocyanine green angiography was performed on 138 eyes of 69 patients. Mean age was 58 ± 16.9 years (range, 24-85 years). The most common ocular pathologies imaged included central serous chorioretinopathy (24 eyes), uveitis (various subtypes, 16 eyes), age-related macular degeneration (12 eyes), and polypoidal choroidal vasculopathy (4 eyes). In all eyes evaluated with ultra-widefield indocyanine green angiography, high-resolution images of choroidal and retinal circulation were obtained with sufficient detail out to 200° of the fundus. In this series of 138 eyes, scanning laser ophthalmoscope-based ultra-widefield indocyanine green angiography was clinically practical and provided detailed images of both the central and peripheral choroidal circulation. Future studies are needed to refine the clinical value of this imaging modality and the significance of peripheral choroidal vascular changes in the diagnosis, monitoring, and treatment of ocular diseases.

Epidemiology of common cold.

PubMed

van Cauwenberge, P B

1985-12-01

The epidemiology of common cold and the role of some predisposing factors were studied by examining 2065 healthy children, aged 2.5-6 years. The examination included a questionnaire, completed by the parents, a general physical examination, a clinical E.N.T.-examination and various technical investigations. The mean annual incidence of common cold was 2.43 (as was reported by the parents) and 5 when taking into consideration the time span between the last episode of common cold and the date of examination. Mucoid and purulent rhinitis were less frequently found in older children. A positive history of upper respiratory tract infections in the parents showed to be the most important risk factor for the occurrence of infectious rhinitis in the children. The higher the weight of the child, the lower the incidence of common cold and the fewer pathological rhinoscopical findings. Children with a head circumference below the 2.5 percentile had the highest incidence of infectious rhinitis. Humid housing conditions showed to be connected with a higher incidence of infectious rhinitis. Children of parents with a higher profession had more rhinitis than children of labourers. Smoking habits of the parents had only little effect on the rhinological status of children.

Drift mobility of photo-electrons in organic molecular crystals: Quantitative comparison between theory and experiment

NASA Astrophysics Data System (ADS)

Reineker, P.; Kenkre, V. M.; Kühne, R.

1981-08-01

A quantitative comparison of a simple theoretical prediction for the drift mobility of photo-electrons in organic molecular crystals, calculated within the model of the coupled band-like and hopping motion, with experiments in napthalene of Schein et al. and Karl et al. is given.

The impacts of repeated cold exposure on insects.

PubMed

Marshall, Katie E; Sinclair, Brent J

2012-05-15

Insects experience repeated cold exposure (RCE) on multiple time scales in natural environments, yet the majority of studies of the effects of cold on insects involve only a single exposure. Three broad groups of experimental designs have been employed to examine the effects of RCE on insect physiology and fitness, defined by the control treatments: 'RCE vs cold', which compares RCE with constant cold conditions; 'RCE vs warm', which compares RCE with constant warm conditions; and 'RCE vs matched cold' which compares RCE with a prolonged period of cold matched by time to the RCE condition. RCE are generally beneficial to immediate survival, and increase cold hardiness relative to insects receiving a single prolonged cold exposure. However, the effects of RCE depend on the study design, and RCE vs warm studies cannot differentiate between the effects of cold exposure in general vs RCE in particular. Recent studies of gene transcription, immune function, feeding and reproductive output show that the responses of insects to RCE are distinct from the responses to single cold exposures. We suggest that future research should attempt to elucidate the mechanistic link between physiological responses and fitness parameters. We also recommend that future RCE experiments match the time spent at the stressful low temperature in all experimental groups, include age controls where appropriate, incorporate a pilot study to determine time and intensity of exposure, and measure sub-lethal impacts on fitness.

Discovery of novel cold-induced CISP genes encoding small RNA-binding proteins related to cold adaptation in barley.

PubMed

Ying, Mengchao; Kidou, Shin-Ichiro

2017-07-01

To adapt to cold conditions, barley plants rely on specific mechanisms, which have not been fully understood. In this study, we characterized a novel barley cold-induced gene identified using a PCR-based high coverage gene expression profiling method. The identified gene encodes a small protein that we named CISP1 (Cold-induced Small Protein 1). Homology searches of sequence databases revealed that CISP1 homologs (CISP2 and CISP3) exist in barley genome. Further database analyses showed that the CISP1 homologs were widely distributed in cold-tolerant plants such as wheat and rye. Quantitative reverse transcription PCR analyses indicated that the expression of barley CISP genes was markedly increased in roots exposed to cold conditions. In situ hybridization analyses showed that the CISP1 transcripts were localized in the root tip and lateral root primordium. We also demonstrated that the CISP1 protein bound to RNA. Taken together, these findings indicate that CISP1 and its homologs encoding small RNA-binding proteins may serve as RNA chaperones playing a vital role in the cold adaptation of barley root. This is the first report describing the likely close relationship between root-specific genes and the cold adaptation process, as well as the potential function of the identified genes. Copyright © 2017 Elsevier B.V. All rights reserved.

7 CFR 305.6 - Cold treatment requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) The cold treatment facility must remain locked during non-working hours. (v) Black light or sticky... hours. (vi) Black light or sticky paper must be used within the cold treatment facility, and other... remain locked during non-working hours. (viii) Black lights or sticky paper must be used within the cold...

Summary: Update to ASTM Guide E 1523 to Charge Control and Charge Referencing Techniques in X-ray Photoelectron Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baer, Donald R.

2005-04-22

An updated version of the ASTM guide E1523 to the methods to charge control and charge referencing techniques in x-ray photoelectron spectroscopy has been released by ASTM. The guide is meant to acquaint x-ray photoelectron spectroscopy (XPS) users with the various charge control and charge referencing techniques that are and have been used in the acquisition and interpretation of XPS data from surfaces of insulating specimens. The current guide has been expanded to include new references as well as recommendations for reporting information on charge control and charge referencing. The previous version of the document had been published in 1997.

Nonadiabatic Dynamics May Be Probed through Electronic Coherence in Time-Resolved Photoelectron Spectroscopy.

PubMed

Bennett, Kochise; Kowalewski, Markus; Mukamel, Shaul

2016-02-09

We present a hierarchy of Fermi golden rules (FGRs) that incorporate strongly coupled electronic/nuclear dynamics in time-resolved photoelectron spectroscopy (TRPES) signals at different levels of theory. Expansion in the joint electronic and nuclear eigenbasis yields the numerically most challenging exact FGR (eFGR). The quasistatic Fermi Golden Rule (qsFGR) neglects nuclear motion during the photoionization process but takes into account electronic coherences as well as populations initially present in the pumped matter as well as those generated internally by coupling between electronic surfaces. The standard semiclassical Fermi Golden Rule (scFGR) neglects the electronic coherences and the nuclear kinetic energy during the ionizing pulse altogether, yielding the classical Condon approximation. The coherence contributions depend on the phase-profile of the ionizing field, allowing coherent control of TRPES signals. The photoelectron spectrum from model systems is simulated using these three levels of theory. The eFGR and the qsFGR show temporal oscillations originating from the electronic or vibrational coherences generated as the nuclear wave packet traverses a conical intersection. These oscillations, which are missed by the scFGR, directly reveal the time-evolving splitting between electronic states of the neutral molecule in the curve-crossing regime.

Unambiguous observation of F-atom core-hole localization in CF 4 through body-frame photoelectron angular distributions

DOE PAGES

McCurdy, C. W.; Rescigno, T. N.; Trevisan, C. S.; ...

2017-01-17

A dramatic symmetry breaking in K-shell photoionization of the CF 4 molecule in which a core-hole vacancy is created in one of four equivalent fluorine atoms is displayed in the molecular frame angular distribution of the photoelectrons. In observing the photoejected electron in coincidence with an F + atomic ion after Auger decay we see how selecting the dissociation path where the core hole was localized was almost exclusively on that atom. A combination of measurements and ab initio calculations of the photoelectron angular distribution in the frame of the recoiling CF 3 + and F + atoms elucidates themore » underlying physics that derives from the Ne-like valence structure of the F(1s -1) core-excited atom.« less

Photoelectron spectrometer for liquid and gas-phase attosecond spectroscopy with field-free and magnetic bottle operation modes

NASA Astrophysics Data System (ADS)

Jordan, Inga; Jain, Arohi; Gaumnitz, Thomas; Ma, Jun; Wörner, Hans Jakob

2018-05-01

A compact time-of-flight spectrometer for applications in attosecond spectroscopy in the liquid and gas phases is presented. It allows for altering the collection efficiency by transitioning between field-free and magnetic-bottle operation modes. High energy resolution (ΔE/E = 0.03 for kinetic energies >20 eV) is achieved despite the short flight-tube length through a homogeneous deceleration potential at the beginning of the flight tube. A closing mechanism allows isolating the vacuum system of the flight tube from the interaction region in order to efficiently perform liquid-microjet experiments. The capabilities of the instrument are demonstrated through photoelectron spectra from multiphoton ionization of argon and xenon, as well as photoelectron spectra of liquid and gaseous water generated by an attosecond pulse train.

Study of organic radicals through anion photoelectron velocity-map imaging spectroscopy

NASA Astrophysics Data System (ADS)

Dixon, Andrew Robert

We report preliminary results on the photoelectron imaging of phenylcarbene, cyanophenylcarbene, and chlorophenylcarbene anions. Triplet phenylcarbene is observed to have an EA of ≤ 0.83 eV, considerably lower than the previously indirectly-determined value. Transitions to the singlet and triplet ground state of both cyanophenylcarbene and chlorophenylcarbene are observable, though unidentified bands make full assignment difficult. Cyanophenylcarbene is found to have a triplet ground-state, with a tentative EA of 2.04 eV. Chlorophenylcarbene is found to have a singlet ground-state. The phenyl-group is found to favor the singlet state slightly. The cyanofluoromethyl radical, FC(H)CN, was estimated to have an EA of 1.53 +/- 0.08 eV, by a combination of experimental and theoretical results.. With similar methodology, we report the adiabatic electron affinity of the cyanobenzyl radical, EA(PhCHCN) = 1.90 +/- 0.01 eV, and assign an upper limit of the EA for the chlorobenzyl radical, EA(PhCHCl) ≤ 1.12 eV. These values were used to estimate the C-H bond dissociation energy (BDE)s for these substituted methanes. Fluoroacetonitrile was found to have a BDE of D H198 = 90.7 +/- 2.8 kcal mol□1. The C-H bond dissociation energies at the benzyl-alpha sites of the phenylmethanes are determined as 80.9 +/- 2.3 kcal mol-1 for benzyl nitrile and an upper limit of 84.2 kcal mol-1 for benzyl chloride. These results are discussed in terms of substituent interactions in a simple MO framework and in relation to other similar molecules, including recently reported results for chloroacetonitrile. The 532 nm photoelectron spectrum of glyoxal provides the first direct spectroscopic determination of the adiabatic electron affinity, EA = 1.10(2) eV. This assignment is supported by a Franck-Condon simulation of the experimental spectrum that successfully reproduces the observed spectral features. The vertical detachment energy (VDE) of the glyoxal radical anion is determined as VDE = 1

Ultra-high-speed 3D astigmatic particle tracking velocimetry: application to particle-laden supersonic impinging jets

NASA Astrophysics Data System (ADS)

Buchmann, N. A.; Cierpka, C.; Kähler, C. J.; Soria, J.

2014-11-01

The paper demonstrates ultra-high-speed three-component, three-dimensional (3C3D) velocity measurements of micron-sized particles suspended in a supersonic impinging jet flow. Understanding the dynamics of individual particles in such flows is important for the design of particle impactors for drug delivery or cold gas dynamic spray processing. The underexpanded jet flow is produced via a converging nozzle, and micron-sized particles ( d p = 110 μm) are introduced into the gas flow. The supersonic jet impinges onto a flat surface, and the particle impact velocity and particle impact angle are studied for a range of flow conditions and impingement distances. The imaging system consists of an ultra-high-speed digital camera (Shimadzu HPV-1) capable of recording rates of up to 1 Mfps. Astigmatism particle tracking velocimetry (APTV) is used to measure the 3D particle position (Cierpka et al., Meas Sci Technol 21(045401):13, 2010) by coding the particle depth location in the 2D images by adding a cylindrical lens to the high-speed imaging system. Based on the reconstructed 3D particle positions, the particle trajectories are obtained via a higher-order tracking scheme that takes advantage of the high temporal resolution to increase robustness and accuracy of the measurement. It is shown that the particle velocity and impingement angle are affected by the gas flow in a manner depending on the nozzle pressure ratio and stand-off distance where higher pressure ratios and stand-off distances lead to higher impact velocities and larger impact angles.

Ultra-low dose (+)-naloxone restores the thermal threshold of morphine tolerant rats.

PubMed

Chou, Kuang-Yi; Tsai, Ru-Yin; Tsai, Wei-Yuan; Wu, Ching-Tang; Yeh, Chun-Chang; Cherng, Chen-Hwan; Wong, Chih-Shung

2013-12-01

As known, long-term morphine infusion leads to tolerance. We previously demonstrated that both co-infusion and post-administration of ultra-low dose (±)-naloxone restores the antinociceptive effect of morphine in morphine-tolerant rats. However, whether the mechanism of the action of ultra-low dose (±)-naloxone is through opioid receptors or not. Therefore, in the present study, we further investigated the effect of ultra-low dose (+)-naloxone, it does not bind to opioid receptors, on the antinociceptive effect of morphine. Male Wistar rats were implanted with one or two intrathecal (i.t.) catheters; one catheter was connected to a mini-osmotic pump, used for morphine (15 μg/h), ultra-low dose (+)-naloxone (15 pg/h), morphine plus ultra-low dose (+)-naloxone (15 pg/h) or saline (1 μl/h) infusion for 5 days. On day 5, either ultra-low dose (+)-naloxone (15 pg) or saline (5 μl) was injected via the other catheter immediately after discontinued morphine or saline infusion. Three hours later, morphine (15 μg in 5 μl saline) or saline were given intrathecally. All rats received nociceptive tail-flick test every 30 minutes for 120 minutes after morphine challenge at different temperature (45-52°C, respective). Our results showed that, both co-infusion and post-treatment of ultra-low dose (+)-naloxone with morphine preserves the antinociceptive effect of morphine. Moreover, in the post administration rats, ultra-low dose (+)-naloxone further enhances the antinociceptive effect of morphine. This study provides an evidence for ultra-low dose (+)-naloxone as a therapeutic adjuvant for patients who need long-term opioid administration for pain management. Copyright © 2013. Published by Elsevier B.V.

21 CFR 880.6085 - Hot/cold water bottle.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices § 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water...

21 CFR 880.6085 - Hot/cold water bottle.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices § 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water...

21 CFR 880.6085 - Hot/cold water bottle.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices § 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water...

21 CFR 880.6085 - Hot/cold water bottle.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices § 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water...

21 CFR 880.6085 - Hot/cold water bottle.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices § 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water...

7 CFR 305.16 - Cold treatment schedules.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Cold treatment schedules. 305.16 Section 305.16... SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Cold Treatments § 305.16 Cold treatment schedules. Treatment schedule Temperature ( °F) Exposure period T107-a 1 34 or below 14 days. 35 or below 16...

Progress toward time-resolved molecular imaging: A theoretical study of optimal parameters in static photoelectron holography

NASA Astrophysics Data System (ADS)