Science.gov (United States)

creating such active galactic nuclei as quasars. Strangely, the center of this fiery whirlpool is offset from the exact center of the galaxy - for a reason that for now remains an...

CERN Document Server

In a recent paper by Hooper and Goodenough, data from the Fermi Gamma Ray Telescope was analyzed and an excess of gamma rays was found in the emission spectrum from the Galactic Center Region. Hooper and Goodenough show that the excess can be well explained by 7-10 GeV annihilating dark matter with a power law density profile if the dark matter annihilates predominantly to tau pairs. In this paper we present such a dark matter model by extending the MSSM to include four Higgs doublets and one scalar singlet. A Z2 symmetry is imposed that enforces a Yukawa structure so that the up quarks, down quarks, and leptons each receive mass from a distinct doublet. This leads to an enhanced coupling of scalars to leptons and allows the model to naturally achieve the required phenomenology in order to explain the gamma ray excess. Our model yields the correct dark matter thermal relic density and avoids collider bounds from measurements of the Z width as ...

CERN Document Server

Recent X-ray and radio observations have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and infrared observations of the transient and its surroundings. Chandra bservations detect the source at a flux of F_X = 2e-12 erg cm^-2 s^-1 (2-8 keV). After accounting for absorption both in the interstellar medium and in material local to the source, the implied luminosity of the source is only L_X = 4e34 erg/s (2-8 keV; D=8 kpc). However, the diffuse X-ray emission near the source also brightened by a factor of 2. The enhanced diffuse X-ray emission lies on top of a known ridge of dust and ionized gas that is visible infrared images. We interpret the X-ray emission as scattered flux from the outburst, and determine that the peak luminosity of CXOGC J174540.0-290031 was >2e36 erg/s. We suggest that the ...

CERN Document Server

In a recent study of a search for enhancements from the galactic center with muons at sea level using the TUPI muon telescope, we have found several ground level enhancements (GLEs) as very sharp peaks above the count rate background. This paper reports a consistent analysis of two GLEs observed in December 2003 and detected after an up-grade of the data acquisition system, which includes a noise filter and which allows us to verify that the GLEs are not mere background fluctuations. The main target of this study is a search for the origin of the GLEs. The results show that one of them has a strong correlation with a solar flare, while the other has an unknown origin, because there is neither a satellite report of a solar flare, nor prompt X-ray emission, and nor a excess of nuclei during the raster scan where the GLE was observed. Even so, two possibilities are analyzed: the solar flare hypothesis and the gamma ray burst (GRB) hypothesis. We ...

Energy Technology Data Exchange (ETDEWEB)

Yet designed to measure charged component of the cosmic rays, the foreseen Alpha Magnetic Spectrometer (AMS-02) could also release {gamma}-ray studies, in the energy range from GeV to TeV, using the tracker system, for {gamma}-rays converted in e{sup +}e{sup -} pair, and the electromagnetic calorimeter. In the first part of the thesis are described the calibrations and the performances of the engineering model of the calorimeter, obtained from the analysis of data taken during a test-beam performed at CERN in July 2002. In the second part of the thesis, the AMS-02 discovery potential for {gamma}-astrophysics is presented. While exposure maps of the {gamma}--sky are computed for one year of data taking with the {gamma}--detectors, the acceptance of the calorimeter is obtained from Monte-Carlo simulations. The AMS-02 potential is then estimated for signals from the Vela pulsar and for some supersymmetric signals from the Galactic Center. (author)

Energy Technology Data Exchange (ETDEWEB)

A remarkably simple argument successfully accounts for the rate of star formation in different galaxies. The snag is that the timescale is uncomfortably short.

Science.gov (United States)

is launched from the Baikonur Cosmodrome in Kazakstan. Tomorrow's picture: A Galactic Whirlpool ...

CERN Document Server

The Galactic Exoplanet Survey Telescope (GEST) will observe a 2 square degree field in the Galactic bulge to search for extra-solar planets using a gravitational lensing technique. This gravitational lensing technique is the only method employing currently available technology that can detect Earth-mass planets at high signal-to-noise, and can measure the frequency of terrestrial planets as a function of Galactic position. GEST's sensitivity extends down to the mass of Mars, and it can detect hundreds of terrestrial planets with semi-major axes ranging from 0.7 AU to infinity. GEST will be the first truly comprehensive survey of the Galaxy for planets like those in our own Solar System.

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The problem on change of deuterium abundance in the process of galactic evolution (star evolution, supernova explosions, nucleosynthesis in supermassive objects) is considered. It is shown that the observable deuterium quantity in the interstellar medium must correspond to its cosmological abundance. This conclusion is independent of the rate of accretion of intergalactic gas by Galaxy. The effect of hypothetical pregalactic active objects on cosmological deuterium is small. It is poind out that observations of interstellar deuterium in absorbtion at lambda=91.6 cm are significant.

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A new era for the field of Galactic structure is about to be opened with the advent of wide-area digital sky surveys. In this article, the author reviews the status and prospects for research for 3 new ground-based surveys: the Sloan Digital Sky Survey (SDSS), the Deep Near-Infrared Survey of the Southern Sky (DENIS) and the Two Micron AU Sky Survey (2MASS). These surveys will permit detailed studies of Galactic structure and stellar populations in the Galaxy with unprecedented detail. Extracting the information, however, will be challenging.

International Nuclear Information System (INIS)

We present new results from BRAVA, a large-scale radial velocity survey of the Galactic bulge, using M giant stars selected from the Two Micron All Sky Survey catalog as targets for the Cerro Tololo Inter-American Observatory 4 m Hydra multi-object spectrograph. The purpose of this survey is to construct a new generation of self-consistent bar models that conform to these observations. We report the dynamics for fields at the edge of the Galactic bulge at latitudes b = -8 deg. and compare to the dynamics at b = -4 deg. We find that the rotation curve V(r) is the same at b = -8 deg. as at b = -4 deg. That is, the Galactic boxy bulge rotates cylindrically, as do boxy bulges of other galaxies. The summed line-of-sight velocity distribution at b = -8 deg. is Gaussian, and the binned longitude-velocity plot shows no evidence for either a (disk) population with cold dynamics or for a (classical bulge) population with hot ...

International Nuclear Information System (INIS)

The authors describe a new method which makes it possible to determine the radial distribution of the diffuse component of galactic gamma rays outside the solar circle. They use the observation that a good correlation exists between gamma-ray intensities and total column densities of the local interstellar gas and that the fractional column density of H_2<0.1 HI outside the solar circle. Thus the gamma-ray intensities are shown to be proportional to N(HI). The authors use the kinematics of the HI to determine the distances from which various fractions of the emission originate in the second and third galactic quadrants. Preliminary results of our analysis show that a significant flux of gamma rays originates from distances as large as 18 kpc from the galactic centre. (Auth.).

CERN Document Server

The study of extragalactic planetary nebulae (EPN) is a rapidly expanding field. The advent of powerful new instrumentation such as the PN spectrograph has led to an avalanche of new EPN discoveries both within and between galaxies. We now have thousands of EPN detections in a heterogeneous selection of nearby galaxies and their local environments, dwarfing the combined galactic detection efforts of the last century. Key scientific motivations driving this rapid growth in EPN research and discovery have been the use of the PNLF as a standard candle, as dynamical tracers of their host galaxies and dark matter and as probes of Galactic evolution. This is coupled with the basic utility of PN as laboratories of nebula physics and the consequent comparison with theory where population differences, abundance variations and star formation history within and between stellar systems informs both stellar and galactic evolution. Here ...

Energy Technology Data Exchange (ETDEWEB)

The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with new instrumentation and new surveys focused on Galactic structure and chemical evolution, measurements of the baryon oscillation feature in the clustering of galaxies and the quasar Ly{alpha} forest, and a radial velocity search for planets around {approx}8000 stars. This paper describes the first data release of SDSS-III (and the eighth counting from the beginning of the SDSS). The release includes 5-band imaging of roughly 5200 deg{sup 2} in the Southern Galactic Cap, bringing the total footprint of the SDSS imaging to 14,555 deg{sup 2}, or over a third of the Celestial Sphere. All the imaging data have been reprocessed with an improved sky-subtraction algorithm and a final, self-consistent recalibration and flat-field determination. This release also includes all data from the second phase of the Sloan Extension for Galactic Understanding and ...

CERN Document Server

Galactic open clusters are since long recognized as one of the best tools for investigating the radial distribution of iron and other metals. We employed FLAMES at VLT to collect UVES spectra of bright giant stars in a large sample of open clusters, spanning a wide range of Galactocentric distances, ages, and metallicities. We present here the results for four clusters: Berkeley 20 and Berkeley 29, the two most distant clusters in the sample; Collinder 261, the oldest and the one with the minimum Galactocentric distance; Melotte 66. Equivalent width analysis was carried out using the spectral code MOOG and Kurucz model atmospheres to derive abundances of Fe, Al, Mg, Si, Ca, Ti, Cr, Ni, Ba; non-LTE Na abundances were derived by direct line-profile fitting. We obtain subsolar metallicities for the two anticenter clusters Be 20 ([Fe/H]=-0.30, rms=0.02) and Be 29 ([Fe/H]=-0.31, rms=0.03), and for Mel 66 ([Fe/H]=-0.33, rms=0.03), located in the third ...

Science.gov (United States)

telluride single crystals. NASA Center: NASA (Unspecified Center) Publication Year: 1966. Document ID: 19670033153. Accession Number: 67A11882 ...

Science.gov (United States)

PMID:5017351

CERN Document Server

We study the Sunyaev-Zel'dovich (SZ) effect potentially generated by relativistic electrons injected from dark matter (DM) annihilation or decay in the Galaxy, and check whether it could be observed by Planck or ALMA, or even imprint the current CMB data as e.g. the specific fluctuation excess claimed from an recent re-analysis of the WMAP-5 data. We focus on high-latitude regions to avoid contamination of the Galactic astrophysical electron foreground, and consider the annihilation or decay coming from the smooth DM halo as well as from subhalos, further extending our analysis to a generic modeling of spikes arising around intermediate-mass-black-holes (IMBHs). We show that all these dark Galactic components are unlikely to produce any observable SZ effect. For a self-annihilating DM particle of 10 GeV with canonical properties, the largest optical depth we find is $\\tau_e \\lesssim 10^{-7}$ for massive isolated subhalos hosting IMBHs. We ...

Energy Technology Data Exchange (ETDEWEB)

Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region (l {element_of} [65{sup o}, 85{sup o}]). For the Cygnus region, the ...

International Nuclear Information System (INIS)

Nuclear reaction rates and opacity are important parameters in stellar evolution. The input physics in a stellar evolution code determines the main theoretical characteristics of the stellar structure, evolution and nucleosynthesis of a star. For different input physics, in this work we calculate stellar evolution models of very massive first stars during the hydrogen and helium burning phases. We have considered 100 and 200M_sun galactic and pregalactic stars with metallicity Z = 10"-"6 and 10"9, respectively. The results show important differences from old to new formulations for the opacity and nuclear reaction rates, in particular the evolutionary tracks are significantly affected, that indicates the importance of using up to date and reliable input physics. The triple alpha reaction activates sooner for pregalactic than for galactic stars.

International Nuclear Information System (INIS)

New surface photometry of all known elliptical galaxies in the Virgo cluster is combined with published data to derive composite profiles of brightness, ellipticity, position angle, isophote shape, and color over large radius ranges. These provide enough leverage to show that Sersic log I #propor to# r "1"/"n functions fit the brightness profiles I(r) of nearly all ellipticals remarkably well over large dynamic ranges. Therefore, we can confidently identify departures from these profiles that are diagnostic of galaxy formation. Two kinds of departures are seen at small radii. All 10 of our ellipticals with total absolute magnitudes M_V_T #<=# -21.66 have cuspy cores-"missing light"-at small radii. Cores are well known and naturally scoured by binary black holes (BHs) formed in dissipationless ("dry") mergers. All 17 ellipticals with -21.54 #<=# M_V_T #<=# -15.53 do not have cores. We find a new distinct component in these galaxies: all coreless ellipticals in our sample have ...

International Nuclear Information System (INIS)

Surface photometry of bulges and elliptical galaxies is reviewed. The properties of cores and nuclei as revealed by improvements in seeing and the use of CCDs are examined, and newly discovered structural details such as dust, shells, and dynamical subsystems which show the importance of accretion events in galactic evolution are addressed. Improved constraints on galaxy formation resulting from better measurements of parameter scaling laws are discussed, and accurate measurements of departures from elliptical isophotes and of color gradients obtained with CCDs are considered.

CERN Document Server

The indirect detection of particle dark matter (DM) is based on the search for anomalous components in cosmic rays (CRs) due to the annihilation of DM pairs in the galactic halo, on the top of the standard astrophysical production. These additional exotic components are potentially detectable at Earth as spectral distortions for the various cosmic radiations: $\\chi + \\chi \\to q \\bar{q}, W^+ W^-, ... \\to \\bar{p}, \\bar{D}, e^+ \\gamma and \

Energy Technology Data Exchange (ETDEWEB)

The contribution of pulsar accelerated nuclei to the cosmic rays inside the Galaxy is calculated assuming that a significant part of the pulsar rotational energy is lost on acceleration of iron nuclei extracted from the surface of the neutron star. Different models of the galactic pulsar population are discussed. It is shown that the best description of the observed cosmic ray spectrum and the mass composition between a few 10{sup 15} eV and a few 10{sup 18} eV is obtained for the model B of Lorimer et al. (1993)

Science.gov (United States)

... Programmatic Terms and Conditions for the Materials Research Science and Engineering Centers (MRSEC ... NSF Grants Officer. 2. Program Description: Materials Research Science and Engineering Centers ...

International Nuclear Information System (INIS)

We present an abundance analysis based on high-resolution spectra of 10 stars selected to span the full range in metallicity in the Ursa Minor (UMi) dwarf spheroidal (dSph) galaxy. We find that [Fe/H] for the sample stars ranges from -1.35 to -3.10 dex. Combining our sample with previously published work for a total of 16 luminous UMi giants, we establish the trends of abundance ratios [X/Fe] as functions of [Fe/H] for 15 elements. In key cases, particularly for the #alpha#-elements, these trends resemble those for stars in the outer part of the Galactic halo, especially at the lowest metallicities probed. The neutron-capture elements show an r-process distribution over the full range of Fe metallicity reached in this dSph galaxy. This suggests that the duration of star formation in the UMi dSph was shorter than in other dSph galaxies. The derived ages for a larger sample of UMi stars with more uncertain metallicities also suggest a population dominated by ...

Science.gov (United States)

Research Center last approximately 1.5 hours and include stops at the Space Weather Prediction Center, ESRL Global Monitoring Division for information on the carbon dioxide...

Science.gov (United States)

Abstract: Inertial navigation error analysis of space vehicle during reentry. NASA Center: Ames Research Center Publication Year: 1963 ...

UK PubMed Central (United Kingdom)

ObjectiveFamily-centered bedside rounds (FCBR) are recommended to improve trainee education, patient outcomes, and family satisfaction. However, bedside teaching...Full Text Available

Science.gov (United States)

The Global Warming International Center (GWIC) is the international body disseminating information on global warming science and policy, serving both governamental, non-governamental ... ...

Wastenet

Pages 184-197: Understanding Personal Change in a Women’s Faith-Based Transitional Center/title link ...titleUnderstanding Personal Change in a Women’s Faith-Based Transitional Center/dc:title

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

Science.gov (United States)

NASA's Ames Research Center awarded Ciencia, Inc., a Small Business Innovation Research contract to

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

Energy Technology Data Exchange (ETDEWEB)

The data center in this study had a total floor area of 8,580 square feet (ft{sup 2}) with one-foot raised-floors. It was a rack lab with 440 racks, and was located in a 208,240 ft{sup 2} multi-story office building in San Jose, California. Since the data center was used only for testing equipment, it was not configured as a critical facility in terms of electrical and cooling supply. It did not have a dedicated chiller system but served by the main building chiller plant and make-up air system. Additionally, it was served by a single electrical supply with no provision for backup power. The data center operated on a 24 hour per day, year-round cycle, and users had all hour full access to the data center facility. The study found that data center computer load accounted for 23% of the overall building electrical load, while the total power consumption attributable to the data ...

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

Using the infrared spectroscopy method, we have studied the effect of thermal dehydration (under vacuum and in air) and treatment with water vapor on the acid centers of very high silicon zeolites of the ZSM type. We have shown that dehydration under vacuum and in air completely and irreversibly removes the OH groups at 1120/sup 0/K, while treatment with water vapor removes these groups at 770/sup 0/K. The Lewis acid centers of dehydrated zeolites (represented by two types of centers) are more heat-stable than the Bronsted acid centers, but the vapor treatment at 1020/sup 0/K leads to the disappearance of the Lewis acid centers. In this work, we discuss the reasons for destruction of the acid centers of the zeolites under different treatment conditions.

International Nuclear Information System (INIS)

We report the discovery of an active galactic nucleus (AGN) pair in the interacting galaxy system IRAS 20210+1121 at z = 0.056. An XMM-Newton observation reveals the presence of an obscured (N _H #approx# 5 x 10"2"3 cm"-"2), Seyfert-like (L _2_-_1_0_k_e_V = 4.7 x 10"4"2 erg s"-"1) nucleus in the northern galaxy, which lacks unambiguous optical AGN signatures. Our spectral analysis also provides strong evidence that the IR-luminous southern galaxy hosts a Type 2 quasar embedded in a bright starburst emission. In particular, the X-ray primary continuum from the nucleus appears totally depressed in the XMM-Newton band as expected in the case of a Compton-thick absorber, and only the emission produced by Compton scattering ('reflection') of the continuum from circumnuclear matter is seen. As such, IRAS 20210+1121 seems to provide an excellent opportunity to witness a key, early phase in the quasar evolution predicted by the theoretical models of quasar activation by ...

CERN Document Server

We study the sensitivity to neutrino masses of a Galactic supernova neutrino signal as could be measured with the detectors presently in operation and with future large volume water \\v{C}erencov and scintillator detectors. The analysis uses the full statistics of neutrino events. The method proposed uses the principles of Bayesian inference reasoning and has shown a remarkably independence of astrophysical assumptions. We show that, after accounting for the uncertainties in the detailed astrophysical description of the neutrino signal and taking into account the effects of neutrino oscillations in the supernova mantle, detectors presently in operation can have enough sensitivity to reveal a neutrino mass (or to set upper limits) at the level of 1 eV. This is sensibly better than present results from tritium $\\beta$-decay experiments, competitive with the most conservative limits from neutrinoless double $\\beta$-decay and less precise but remarkably less ...

International Nuclear Information System (INIS)

Magnetically driven non-stationary acceleration of jets in active galactic nuclei results in the leading parts of the flow being accelerated to much higher Lorentz factors than in the case of steady-state acceleration with the same parameters. The higher Doppler-boosted parts of the flow may dominate the high-energy emission of blazar jets. We suggest that highly variable GeV and TeV emission in blazars is produced by the faster moving leading edges of highly magnetized non-stationary ejection blobs, while the radio data trace the slower-moving bulk flow. Thus, the radio and gamma-ray emission regions have different, but correlated, Doppler factors. High-energy emission is generated, typically within the optically thick core, in the outer parts of the broad-line emission region, avoiding the radiative drag on the faster parts of the flow. The radio emission should correlate with the gamma-ray emission, delayed with frequency-dependent time lag of the order of weeks ...

CERN Document Server

Gemini North adaptive optics imaging spectroscopy is presented for the Galactic ultra-compact HII (UCHII) region K3-50A. Data were obtained in the K-band using the Near-infrared Integral Field Spectrograph (NIFS) behind the facility adaptive optics module ALTAIR in natural guide star mode. The NIFS data cube reveals a complex spatial morphology across the 0.1 pc scale of the 3'' UCHII region. Comparison of the nebular emission to Cloudy ionization models shows that the central source must have an effective temperature between about 37000 K and 45000 K with preferred values near 40000 K. Evidence is presented for sharp density variations in the nebula which are interpreted as a clearing of material nearest the central source. High excitation lines of FeIII and SeIV show that the ionization of the nebula clearly changes with distance from the central source. A double lobed kinematic signature (+/- 25 kms) is evident in the Br gamma line map which may be related to ...

CERN Document Server

In this work we develop a new propagation model for the Galactic cosmic rays based on the GALPROP code, including contributions from dark matter annihilation. The model predicts compatible Galactic diffuse $\\gamma$ ray spectra with EGRET data in all sky regions. It also gives consistent results of the diffuse $\\gamma$ ray longitude and latitude distributions. Further the results for B/C, $^{10}$Be/$^9$Be, proton, electron and antiproton spectra are also consistent with cosmic ray measurements. In the model we have taken a universal proton spectrum throughout the Galaxy without introducing large fluctuation for the proton energy loss is negligible. The dark matter annihilation signals are `boosted' after taking the contribution from subhalos into account. Another interesting feature of the model is that it gives better description of the diffuse $\\gamma$ rays when taking the source distribution compatible with supernova remnants data, which ...

CERN Document Server

Antideuterons are among the most promising galactic cosmic ray-related targets for dark matter indirect detection. Currently only upper limits exist on the flux, but the development of new experiments, such as GAPS and AMS-02, provides exciting perspectives for a positive measurement in the near future. In this Paper, we present a novel and updated calculation of both the secondary and primary antideuteron fluxes. We employ a two-zone diffusion model which successfully reproduces cosmic-ray nuclear data and the observed antiproton flux. We review the nuclear and astrophysical uncertainties and provide an up to date secondary (i.e. background) antideuteron flux. The primary (i.e. signal) contribution is calculated for generic WIMPs annihilating in the galactic halo: we explicitly consider and quantify the various sources of uncertainty in the theoretical evaluations. Propagation uncertainties, as is the case of antiprotons, are sizeable. ...

CERN Document Server

The energy fed by active galactic nuclei to the surrounding diffuse baryons changes the latter's amount, temperature, and distribution; so in groups and in member galaxies it affects the X-ray luminosity and also the Sunyaev-Zel'dovich effect. Here we compute how the latter is enhanced by the transient blastwave driven by a shining quasar, and is depressed when the equilibrium is recovered with a depleted density. We constrain such depressions and enhancements with the masses of relic black holes in galaxies and the X-ray luminosities in groups. We discuss how all these linked observables can tell the quasar contribution to the thermal history of the baryons pervading galaxies and groups.

International Nuclear Information System (INIS)

The mass distribution of the Sombrero Galaxy, NGC 4594, is calculated in order to investigate the suspicion that the rotational velocity of the galactic gas does not measure the circular velocity in the galaxy. It is shown that the H II rotation velocities are much less than circular in the central 35 arcsec of the galaxy, and that the suspicion is correct. Thus, the H II rotation velocities cannot be used to measure the mass distribution. The absorption-line rotation curve is used to derive the mass distribution, and it is found that the M/L ratio is nearly constant. It is concluded that the visible matter is self-gravitating at least in the central 180 arcsec. 44 references.

Energy Technology Data Exchange (ETDEWEB)

The group- V vacancy pair, the so-called E-center, has recently been demonstrated to have, both in Si and Ge, more complicated energy-level schemes in the energy gap than were previously assumed. The E-center in silicon has, in addition to its well-established single-acceptor level in the upper half of the band gap, also a donor level in the lower half of the band gap; this donor level has lain hidden for more than 40 years. The E-center in Ge has an even more complicated level scheme as it induces, in addition to two levels analogous to those found in Si, also a double-acceptor level in the upper half of the band gap. Thus the E-center in Si can exist in three charge states and the E-center in Ge in four.

Energy Technology Data Exchange (ETDEWEB)

Short communication.

Energy Technology Data Exchange (ETDEWEB)

This quarterly update contains information on the National Bioenergy Center Biochemical Platform Integration Project, R&D progress and related activities.

Science.gov (United States)

Oct 11, 1993 ... Lease: Meadowgreen,3-2.5-2, 2 storyon cuI- ..... also will have the Lunar Landing Training Vehicle elevated over the center of the ...

Science.gov (United States)

Hour Fitness Center 24 Hour Market 24 Fitness Center Indoor Heated Pool with Whirlpool Seasonal Outdoor Pool Plaza w/ Outdoor Tiki Bar & Café 1,200 Square Foot Total of...

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Features: CHUQUICAMATA, LARGE OPEN PIT MINING OPERATIONS, ROADS, HILLS Center Point Latitude: -22.3 Center Point Longitude: -68.9 (Negative numbers indicate ...

International Nuclear Information System (INIS)

... Toshiba Corporation, Isogo Engineering Center, Yokohama, Kanagawa (Japan)

International Nuclear Information System (INIS)

... Development Center, National Tsing-Hua University, Hsinchu, TW (China)

Science.gov (United States)

No abstract prepared.

International Nuclear Information System (INIS)

The color centers, which are generated in yttrium-aluminium perovskite (YAP):Nd(1 at.%) and YAP:Er(50 at.%) crystals under the influence of ultraviolet and #gamma#-irradiation, have been studied by absorption spectroscopy. The generated color centers are both stable and transient at room temperature. It is shown that the transient color centers are mainly responsible for the decrease of laser generation efficiency of Nd:YAP and YAP:Er irradiated crystals, although physical mechanisms leading to efficiency decrease are different in these materials. (orig.)

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A Java-language computer program has been written to facilitate mining of data in files in the

Science.gov (United States)

A unique mechanistic method has been developed at the NASA Glenn Research Center to

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

International Nuclear Information System (INIS)

(Aug 1973). United States Moser, AR Matzner, RA Ryan, MP Jr. Center

International Nuclear Information System (INIS)

In CsCdBr_3, Tm"3"+ substitutes for Cd"2"+. It predominately forms symmetric dimer centers and single-ion centers, both of trigonal symmetry. The energy level schemes of both centers were determined by EPR and site-selective laser spectroscopy. To describe the spectra term dependent crystal-field parameters were deduced on the basis of a microscopic model taking into account the local lattice deformation induced by the impurity centers and the quasi-resonant virtual scattering of intrinsic lattice excitations by the Tm"3"+ ions. (orig.)

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

Science.gov (United States)

... magnetic containment field lines which is zero on the center line of the toroidal containment tube and increases in magnitude with ...

Science.gov (United States)

... The total hemispherical emittance rig has been returned to service and the quality of temperature measurement has been investigated. ...

Energy Technology Data Exchange (ETDEWEB)

A variety of engineering and experimental applications require primary support structures which are self-centering. High mechanical strength, low-density, carbon fiber/epoxy matrix composite springs are used in unique planar, cylindrical, conical, and spherical configurations to self-center components. The sinusoidal and triangular-shaped composite springs are readily manufactured and assembled into component hardware. Design considerations, flexural strength properties, load bearing and centering data plus procedures for the manufacture of composite springs are presented.

International Nuclear Information System (INIS)

... Sciences, Research Center for Radiation Protection, Chiba (Japan) Hafez,

Science.gov (United States)

Meet the NCI Expert: Edward Helton (Center for Biome dical Informatics and Information Technology) Orange County Convention Center: NCI Exhibit Booth #500 20110404T140000Z PRODID -//Microsoft Corporation//Outlook 12.0 MIMEDIR//EN 2.0 METHOD PUBLISH X-MS-OLK-FORCEINSPECTOROPEN TRUE PUBLIC CREATED 20110308T204510Z American

International Nuclear Information System (INIS)

The DLTS technique was employed to study deep defect centers in Si doped epitaxial layers of Al_0_._3_7Ga_0_._1_6In_0_._4_7P grown by MOCVD as a part of epitaxial structure GaAs/AlGaInP/GaAs on GaAs substrates. A high concentration of DX centers located in a region near the inverted interface GaAs/Al_0_._3_7Ga_0_._1_6In_0_._4_7P was found. The width of this region with the maximum DX center concentration ranges from 5 to 20 nm. By filling the DX centers in the whole region, the activation energy for electron emission was found to be 0.48 eV. However, it is shown for the first time, that the activation energy of the DX center increases with increasing the distance from the GaAs/Al_0_._3_7Ga_0_._1_6In_0_._4_7P inverted interface. A nonuniform of the DX center concentration on the wafers is also observed. The concentration varies in the range of 1#centre dot#10"1"7 ...

CERN Document Server

Simple, one-zone models for inhomogeneous chemical evolution of the Galactic halo are used to predict the number fraction of zero-metallicity, Population III stars, which currently is empirically estimated at < 4e-4. These analytic models minimize the number of free parameters, highlighting the most fundamental constraints on halo evolution. There are disagreements of at least an order of magnitude between observations and predictions in limiting cases for both homogeneous Simple Model and Simple Inhomogeneous Model (SIM). Hence, this demonstrates a quantitative, unambiguous discrepancy in the observed and expected fraction of Population III stars. We explore how the metallicity distribution of the parent enrichment events f(z_0) drives the SIM and predictions for the Population III fraction. The SIM shows that the previously-identified "high halo" and "low halo" populations are consistent with a continuous evolutionary progression, and therefore may not ...

Energy Technology Data Exchange (ETDEWEB)

In this talk, we summarize recent results obtained from the combined neutrino telescopes IceCube and AMANDA. The combined approach, including data taken from both detectors simultaneously, is compared to other analyses that are using IceCube only data. The main benefit of the combined detector is its improved performance at low energies, meaning energies below 1 TeV (close to the energy threshold of the detector). The discussion is focused on the search for extra-terrestrial neutrinos from candidate sources in our Galaxy. Using appropriate cuts, the sensitivity can be optimized for soft spectra neutrino sources. With the resulting data sample, several studies are performed: an unbinned Galactic Plane Scan and a Cygnus region analysis: the Multi Point Source analysis. The current status of these analyses is presented.

CERN Document Server

Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET shows all the features expected from DMA. The new precise measurements of the antiproton and positron fractions from PAMELA are compared with the EGRET excess. It is shown that the charged particles are strongly dependent on the propagation model used. The usual propagation models with isotropic propagation models are incompatible with the recently observed convection in our Galaxy. Convection leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a rather small convection will let drift the charged particles in the halo to outer space. It is shown that such anisotropic propagation models including convection prefer a contribution from DMA for the antiprotons, but the rise in the positron fraction, ...

British Library Electronic Table of Contents (United Kingdom)

Using the Galaxy as an example, we study the effect of Formula Not Shown force on the rotational curves of gas and plasma in galaxies. Acceptable model for the galactic magnetic field and plausible physical parameters are used to fit the flat rotational curve for gas and plasma based on the observed baryonic (visible) matter distribution and Formula Not Shown force term in the static MHD equation of motion. We also study the effects of varied strength of the magnetic field, its pitch angle and length scale on the rotational curves. We show that Formula Not Shown force does not play an important role on the plasma dynamics in the intermediate range of distances 6?12?kpc from the centre, whilst the effect is sizable for larger r (r?15?kpc), where it is the most crucial.

CERN Document Server

The next decade promises an observational revolution which will change cosmology forever. The precise measurement of the angular anisotropy of the cosmic microwave background should specify to a few percent all of the parameters of the cosmological model which effect astrophysics. The growth of structure will then be determined (but not yet observed) until gravitational collapse becomes highly non-linear and stars, galaxies and active galactic nuclei (AGN) form. These processes are hard to model with basic physics because they are complex and allow a rich variety of expression. Instead observations will determine when the first stars and quasars formed, and how and when galaxies assembled. If we can reconcile the numerous contradictions which characterize the subject today, cosmology will become a mature subject, founded on the agreement between detailed, inclusive and realistic models, which make precise predictions, and the wealth of new data which will come from ...

Energy Technology Data Exchange (ETDEWEB)

In FY-2000, Engineering at Lawrence Livermore National Laboratory faced significant pressures to meet critical project milestones, and immediate demands to facilitate the reassignment of employees as the National Ignition Facility (the 600-TW laser facility being designed and built at Livermore, and one of the largest R&D construction projects in the world) was in the process of re-baselining its plan while executing full-speed its technology development efforts. This drive for change occurred as an unprecedented level of management and program changes were occurring within LLNL. I am pleased to report that we met many key milestones and achieved numerous technological breakthroughs. This report summarizes our efforts to perform feasibility and reduce-to-practice studies, demonstrations, and/or techniques--as structured through our technology centers. Whether using computational engineering to predict how giant structures like suspension bridges will ...

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We analyze the timing of photons observed by the MAGIC telescope during a flare of the active galactic nucleus Mkn 501 for a possible correlation with energy, as suggested by some models of quantum gravity (QG), which predict a vacuum refractive index {approx_equal}1+(E/M{sub QGn}){sup n}, n=1,2. Parametrizing the delay between {gamma}-rays of different energies as {delta}t={+-}{tau}{sub l}E or {delta}t={+-}{tau}{sub q}E{sup 2}, we find {tau}{sub l}=(0.030{+-}0.012) s/GeV at the 2.5-{sigma} level, and {tau}{sub q}=(3.71{+-}2.57)x10{sup -6} s/GeV{sup 2}, respectively. We use these results to establish lower limits M{sub QG1}>0.21x10{sup 18} GeV and M{sub QG2}>0.26x10{sup 11} GeV at the 95% C.L. Monte Carlo studies confirm the MAGIC sensitivity to propagation effects at these levels. Thermal plasma effects in the source are negligible, but we cannot exclude the importance of some other source effect.

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Electric utilities are actively seeking ways of optimizing the economics of their operations by improving productivity and reducing time and money spent on maintenance. Iberdrola, a Spanish utility, is using advanced machine condition-monitoring technology to centralize control and maintenance of its hydropower projects as a means of achieving those goals. The company is using a blend of technologies to supervise their projects from a regional control center. The monitoring scheme makes use of data from on-line, machine-condition monitors, displays from in-plant audio asnd video equipment, and analysis from the control center`s SCADA system.

Science.gov (United States)

This paper obtains the acidity spectra of modernites and SVK-zeolites from the heats of adsorption of NH/sub 3/ at 300 C and compares the catalytic activity of these zeolites with the cracking of n-octane and the isomerization of o-xylene. It is shown that the calculation of the specific catalytic activity of centers of different strengths by the method of regional rates allows one to predict the activity of the zeolites from the acidity spectra. It follows from the calculation that only the centers of Bronsted acidity are active towards cracking but that the centers of Lewis acidity are also active towards isomerization.

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Earlier studies had concluded that the preferred direction of the rocket nozzle should ..... Center had to redesign the sensor canisters, brackets and cable supports. ... depending on inspection of the quality of the incoming pictures in real-time. ...

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... Multi-robot Operator Control ... Way-point navigation (UUV performing lawn-mower ... Funded by JIEDDO to improve operation of EOD robots ...

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The results of this research centered on the experimental studies of a single superconducting persistent current qubit, the implementation of type-II algorithms using these qubits, and the proposal for adiabatic quantum computing using these qubits. The m...

International Nuclear Information System (INIS)

Lead is known to enter substitutionally in divalent state when doped in alkali halides. When irradiated at room temperature these lead centers (Pb"+"+) act as traps for electrons knocked off from the halogen ions and become Pb"+ and Pb"0 (for large doses of irradiation). These changes could be followed in the optical absorption studies. These lead-doped crystals after X-ray irradiation yield a thermoluminescence output smaller than that observed in 'pure' crystals. However, two new glow peaks are observed in additions to those due to F-centers. In KCl : Pb and Kbr : Pb crystals part of the F-center glow preceds the new glow peaks. The new peaks are attributed to the Pb"+ and Pb"0 centers. The glow peak temperatures and trap depths for these peaks an obtained by total-curve fitting method are reported. (author).

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... Astronomy & Space Biology Chemistry & Materials Computing Earth & Environment Education ... Materials Research Center at the University of Chicago, one of nearly 30 NSF-supported Materials ...

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Education resources dealing with solar-terrestrial physics, solar effects, solar radiation, etc. Includes links to short reference papers on subjects ... ...

Medline Plus

ROBOT-ASSISTED RADICAL LAPAROSCOPIC PROSTATECTOMY WAKE FOREST UNIVERSITY BAPTIST MEDICAL CENTER WINSTON-SALEM, NC 00:00:08 ANTHONY ATALA, MD: I would like ...

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This paper summarizes the main features of four current REDD proposals: Compensated Reduction, Papua New Guinea et al; Joint Research Center; and Brazil. ... ...

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Sep 12, 1975 ... POCKET CALCULATORS. Jose P. Olivares 35, Robert B. Clowns and ... of pocket calculators and has an- Washington to arrive by Nov. 20. ...

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... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

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... 9 SIMPLIFICATION STUDY RECOMMENDATIONS - MIL-STD-2073-1/2 ... SIMPLIFICATION STUDY RECOMMENDATIONS - MIL-STD-2073-1/2 ...

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Data on French nuclear electricity generation sites, nuclear power plant operations personnel, operation simulators, nuclear training centers and training statistics are presented.

UK PubMed Central (United Kingdom)

Like few other organs, the skin is continuously exposed to multiple exogenous and endogenous stressors. Superimposed on this is the impact of psychological stress on skin physiology and pathology....Full Text Available

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and the Wildland Firefighter Foundation. To request a marker click here. Engraved bricks may also be purchased from the Foundation to become part of the site. To request a...

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Co-op students hired since December 3, 1983 will be covered under FERS. ... amount of sick leave that can be accumulated for use in succeeding years. 11. ...

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A waterjet coating-removal system was developed at NASA's Marshall Space Flight Center in Huntsville, Ala., to remove thermal protective coatings from the ...

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NASA Nebula in Action: Cloud Computing Case Examples. James Williams, NASA Ames Research Center, james.f.williams@nasa.gov. Abstract In 2009 ...

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Aug 21, 2003 ... Her research interests have included hot stars, colliding stellar winds, binary star evolution and evolved stellar companions. ...

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star formation. To either side of the center, a small bar of dust and gas is helping to fuel the new stars. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the...

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The Bantam System Technology Project is one element of the Advanced Space Transportation Program -- a NASA initiative to reduce the cost of space launch and ...

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... established in allied communications publications (ACP); DISA circulars (DISAC), Joint Army-Navy-Air Force publications (JANAP), and MAJ- COM ...

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Liquid nitrogen dewar loading at Kennedy Space Center for STS-71 flight with Stan Koszelak (right),

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the Missionaries and Cannibals, Fool's Disk, the Blocks World. and the 8-Puzzle. Also ...... place the sets of missionaries and cannibals by ob- ...

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... of China Lake Naval Weapons Center, California. ... Figure 4: The Space-Based Laser cleaning ... of Aeronautics and Astronautics (AIAA) Space 2001 ...

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A new supersymmetric gauge-invariant model is proposed. It is shown that the hidden-symmetry algebra for this model is the Kac-Moody algebra without a center.

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indicate incipient flow separation. The peak stagnation line ...... culations of Transonic Fan Performance, AGARD Propul- sion and Energetics Symposium on ...

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... Institute of Plasma Physics, National Science Center 'Kharkov Institute of

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and audio technology. The exhibition will travel to muse- ums and science centers in several U.S. cities over the next 5 years. Back in the classroom, ...

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(1976). USSR Lupin, VM Ramazanov, PE Tomskij Gosudarstvennyj Univ.

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Jun 25, 1982 ... stove cooktop, great for camp or cot- ment for rent by day, week or month. $4, 000 neg. Call Mike, 483-4231 ...

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diet and genetic obesity metabolic defects and inflammation. To determine the role of adipocyte death in promoting adipose tissue inflammation and insulin resistance in animal...

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CESAREAN SECTION SHAWNEE MISSION MEDICAL CENTER MERRIAM, KANSAS March 13, 2008 00:00:09 ANNOUNCER: Tonight you will experience the miracle of birth during ...

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evaluation, novelty detection, resource discovery, interfaces and visualization, digital libraries, computational social science, and cross-lingual information retrieval. The CIIR...

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... a Networked Embedded Sensing Toolkit (MSR Sense ... edging due to mis-registration than the ... Langrebe, Signal theory in multisensor remote sensing ...

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respectively. This is a NASA and GSFC requirement to help ensure our computer and network security on center. In the near future, ftp access, with the exception of anonymous ftp of...

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Aug 6, 2009 ... be cleaned with common household disinfectants regularly and after increased crowd contact. Marshall's Emergency Operations Center and the ...

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The NASA Langley Distributed Active Archive Center archives and distributes data relating to Radiation Budget, Clouds, Aerosols, and Troposheric Chemistry.

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credited for unused sick leave when they retire.) The FERS Sick Leave Credit would provide the exact same benefit to FERS ...

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We advance a tentative composite model for computer security at JPL, together with inter and intra networking with other NASA centers and overseas clients.

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inhi bi Led ethylene glycol-water solutions for Apol lo spacecraft en- vironmental control systems (I), the concentration of sodium sulfi te ...

Wastenet

...Resort and Convention Center, National Harbor, Maryland, USA September 18-20, 2011 XX HELSINKI DRUG RESEARCH CONGRESS Helsinki, Finland October 23-27, 2011 2011 AAPS Annual Meeting and Exposition Washington Convention Center Washington, DC June 26-29 2012 10th International Symposium on Pharmaceutical Sciences Ankara, Turkey Printer-friendly version Home | Elsevier ...

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... Studies People Projects Opportunities Framework Critical Sectors Development Goals Geographic Region Geographic Scale Research Themes Printer-Friendly Center for Ocean Solutions Early Career Fellowship Program Location: Stanford, California Source: The Center for Ocean Solutions (“Ocean Solutions”) seeks one or more recent graduates who have received a JD, MBA or PhD in the natural, physical or social sciences in the last five years, and who ...

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This report summarizes activities of the Amarillo National Resource Center for Plutonium during the quarter. The report describes the Electronic Resource Library; DOE support activities; current and future environmental health and safety programs; pollution prevention and pollution avoidance; communication, education, training, and community involvement programs; and nuclear and other material studies, including plutonium storage and disposition studies.

Science.gov (United States)

A consortium of four institutions, based at Western Michigan University, was to plan a Research and Development Center on Student Testing, Evaluation, and Standards Setting. The four consortium sites are Boston College, the Dallas Independent School District, the University of Kansas, and Western Michigan University. This report is a final performance report for the planning grant made to Western Michigan University by the National Institute of Education. The first section provides a summary of the planning activities actually conducted under the grant. It includes a description of particular problems and successes, a list of participants and their affiliations, and an evaluation report for the planning project. The second section is a technical report on the Research and Development (R and D) mission for the Center. It updates the mission and strategy statement contained in the planning grant application and includes an agenda, with ...

Energy Technology Data Exchange (ETDEWEB)

This study presents a dynamic analysis of a rotor supported by two turbulent flow model journal bearings and lubricated with couple stress fluid under nonlinear suspension. The dynamics of the rotor center and bearing center is studied. The dynamic equations are solved using the Runge-Kutta method. The analysis methods employed in this study is inclusive of the dynamic trajectories of the rotor center and bearing center, power spectra, Poincare maps and bifurcation diagrams. The maximum Lyapunov exponent analysis is also used to identify the onset of chaotic motion. The results show that the values of dimensionless parameters l* strongly influence dynamic motions of bearing and rotor centre. It is found that couple stress fluid improve the stability of the system when l* > 0.4 even if the flow of this system is turbulent. We also demonstrated that the dimensionless rotational speed ratios s and ...

Energy Technology Data Exchange (ETDEWEB)

This study presents a dynamic analysis of a flexible rotor supported by two porous squeeze couple stress fluid film journal bearings with non-linear suspension. The dynamics of the rotor center and bearing center are studied. The analysis of the rotor-bearing system is investigated under the assumptions of non-Newtonian fluid and a short bearing approximation. The spatial displacements in the horizontal and vertical directions are considered for various non-dimensional speed ratios. The dynamic equations are solved using the Runge-Kutta method. The analysis methods employed in this study is inclusive of the dynamic trajectories of the rotor center and bearing center, power spectra, Poincare maps and bifurcation diagrams. The maximum Lyapunov exponent analysis is also used to identify the onset of chaotic motion. The numerical results show that the stability of the system varies with the non-dimensional ...

CERN Document Server

We study the high-energy emission of the Galactic black hole candidate GX 339-4 using INTEGRAL/SPI and simultaneous RXTE/PCA data. By the end of January 2007, when it reached its peak luminosity in hard X-rays, the source was in a bright hard state. The SPI data from this period show a good signal to noise ratio, allowing a detailed study of the spectral energy distribution up to several hundred keV. As a main result, we report on the detection of a variable hard spectral feature (>150 keV) which represents a significant excess with respect to the cutoff power law shape of the spectrum. The SPI data suggest that the intensity of this feature is positively correlated with the 25 - 50 keV luminosity of the source and the associated variability time scale is shorter than 7 hours. The simultaneous PCA data, however, show no significant change in the spectral shape, indicating that the source is not undergoing a canonical state transition. We analyzed the broad band ...

CERN Document Server

Magnetic fields correlated on several kiloparsec scales are seen in spiral galaxies. Their origin could be due to the winding up of a primordial cosmological field or due to amplification of a small seed field by a turbulent galactic dynamo. Both options have difficulties: There is no known battery mechanism for producing the required primordial field. Equally the turbulent dynamo may self destruct before being able to produce the large scale field, due to excess generation of small scale power. The current status of these difficulties is discussed. The resolution could depend on the nature of the saturated field produced by the small scale dynamo. We argue that the small scale fields do not fill most of the volume of the fluid and instead concentrate into intermittent ropes, with their peak value of order equipartition fields, and radii much smaller than their lengths. In this case these fields neither drain significant energy from the turbulence nor convert eddy ...

CERN Document Server

We present a detailed spectral analysis of point-like X-ray sources in the XMM-COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10 keV energy band and have been identified through optical spectroscopy. The majority of the sources are well described by a simple power-law model with either no absorption (76%) or a significant intrinsic, absorbing column (20%).As expected, the distribution of intrinsic absorbing column densities is markedly different between AGN with or without broad optical emission lines. We find within our sample four Type-2 QSOs candidates (L_X > 10^44 erg/s, N_H > 10^22 cm^-2), with a spectral energy distribution well reproduced by a composite Seyfert-2 spectrum, that demonstrates the strength of the wide field XMM/COSMOS survey to detect these rare and underrepresented sources.

CERN Document Server

PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range (protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antimatter with a precision of the order of $10^{-8}$). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15 2006 in a $350\\times 600 km$ orbit with an inclination of 70 degrees. The detector is composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, Time-of-Flight and rigidity information. Lepton/hadron identification is performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the satellite. In self-trigger ...

CERN Document Server

We study the stellar and dust properties of a well-defined sample of local elliptical galaxies to investigate the relationship between host galaxy properties and nuclear activity. We select a complete sample of 45 ellipticals from the Palomar spectroscopic survey of nearby galaxies, which includes 20 low-luminosity active galactic nuclei classified as LINERs and 25 inactive galaxies. Using a stellar population synthesis method, we compare the derived stellar population properties of the LINER versus the inactive subsamples. We also study the dust and stellar surface brightness distributions of the central regions of these galaxies using high-resolution images obtained with the {\\it Hubble Space Telescope}. Relative to the inactive subsample, ellipticals hosting LINERs share similar total optical and near-infrared luminosity, central stellar velocity dispersions, and nuclear stellar populations as judged from their luminosity-weighted ages and metallicities. ...

CERN Document Server

The data obtained by the recent modern sky surveys enable detailed studies of the stellar distribution in the multi-dimensional space spanned by spatial coordinates, velocity and metallicity, from the solar neighborhood all the way out to the outer Milky Way halo. While these results represent exciting observational breakthroughs, their interpretation is not simple. For example, traditional decomposition of the thin and thick disks predicts a strong correlation in metallicity and kinematics at $\\sim$1 kpc from the Galactic plane; however, recent SDSS--based work has demonstrated an absence of this correlation for disk stars. Instead, the variation of the metallicity and rotational velocity distributions can be modeled using non--Gaussian functions that retain their shapes and only shift as the distance from the mid--plane increases. To fully contextualize these recent observational results, a detailed comparison with sophisticated numerical models is necessary. ...

CERN Document Server

We propose the Particle Swarm Optimization (PSO) as an alternative method for locating periodic orbits in a three--dimensional (3D) model of barred galaxies. We develop an appropriate scheme that transforms the problem of finding periodic orbits into the problem of detecting global minimizers of a function, which is defined on the Poincar\\'{e} Surface of Section (PSS) of the Hamiltonian system. By combining the PSO method with deflection techniques, we succeeded in tracing systematically several periodic orbits of the system. The method succeeded in tracing the initial conditions of periodic orbits in cases where Newton iterative techniques had difficulties. In particular, we found families of 2D and 3D periodic orbits associated with the inner 8:1 to 12:1 resonances, between the radial 4:1 and corotation resonances of our 3D Ferrers bar model. The main advantages of the proposed algorithm is its simplicity, its ability to work using function values solely, as well as its ability to ...

CERN Document Server

Primordial black holes are unique probes of cosmology, general relativity, quantum gravity and non standard particle physics. They can be considered as the ultimate particle accelerator in their last (explosive) moments since they are supposed to reach, very briefly, the Planck temperature. Upper limits on the primordial black hole number density of mass $M_{\\star} = 5 10^{14}$ g, the Hawking mass (born in the big-bang terminating their life presently), is determined comparing their predicted cumulative $\\gamma$-ray emission, galaxy-wise, to the one observed by the EGRET satellite, once corrected for non thermal $\\gamma$-ray background emission induced by cosmic ray protons and electrons interacting with light and matter in the Milky Way. A model with free gas emissivities is used to map the Galaxy in the 100 MeV photon range, where the peak of the primordial black hole emission is expected. The best gas emissivities and additional model parameters are obtained by fitting the EGRET ...

CERN Document Server

The narrow emission line spectra of active galactic nuclei are not accurately described by simple photoionization models of single clouds. Recent Hubble Space Telescope images of Seyfert 2 galaxies show that these objects are rich with ionization cones, knots, filaments, and strands of ionized gas. Here we extend to the narrow line region the ``locally optimally emitting cloud'' (LOC) model, in which the observed spectra are predominantly determined by powerful selection effects. We present a large grid of photoionization models covering a wide range of physical conditions and show the optimal conditions for producing many of the strongest emission lines. We show that the integrated narrow line spectrum can be predicted by an integration of an ensemble of clouds, and we present these results in the form of diagnostic line ratio diagrams making comparisons with observations. We also predict key diagnostic line ratios as a function of distance from the ionizing ...

CERN Document Server

We present Sauron 2D spectrography of the central 1.5 kpc of the nearby Sey2 galaxy NGC1068, encompassing the well-known NIR inner bar. We have successively disentangled the respective contributions of the ionized gas and stars, thus deriving their 2D distribution and kinematics. The [OIII] and Hbeta emission lines exhibit very different spatial distribution and kinematics, the latter following inner spiral arms with clumps associated with star formation. Strong inwards streaming motions are observed in both the Hbeta and [OIII] kinematics. The stellar kinematics also exhibit clear signatures of a non-axisymmetric tumbling potential, with a twist in both the velocity and h3 fields. We re-examined the long-slit data of Shapiro et al (2003) using pPXF: a strong decoupling of h3 is revealed, and the central decrease in h4 hinted in the Sauron data is confirmed. These data also suggest that NGC1068 is a good candidate for a so-called sigma-drop. We confirm the possible presence of two ...

CERN Document Server

Some models for quantum gravity (QG) violate Lorentz invariance and predict an energy dependence of the speed of light, leading to a dispersion of high-energy gamma-ray signals that travel over cosmological distances. Limits on the dispersion from short-duration substructures observed in gamma-rays emitted by gamma-ray bursts (GRBs) at cosmological distances have provided interesting bounds on Lorentz invariance violation (LIV). Recent observations of unprecedentedly fast flares in the very-high energy gamma-ray emission of the active galactic nuclei (AGNs) Mkn 501 in 2005 and PKS 2155-304 in 2006 resulted in the most constraining limits on LIV from light-travel observations, approaching the Planck mass scale, at which QG effects are assumed to become important. I review the current status of LIV searches using GRBs and AGN flare events, and discuss limitations of light-travel time analyses and prospects for future instruments in the gamma-ray domain.

International Nuclear Information System (INIS)

Through analysis of archival images and photometry from the Spitzer GLIMPSE and MIPSGAL surveys combined with Two Micron All Sky Survey and MSX data, we have identified 488 candidate young stellar objects (YSOs) in the giant molecular cloud M17 SWex, which extends #approx#50 pc southwest from the prominent Galactic H II region M17. Our sample includes >200 YSOs with masses >3 M _s_u_n that will become B-type stars on the main sequence. Extrapolating over the stellar initial mass function (IMF), we find that M17 SWex contains >1.3 x 10"4 young stars, representing a proto-OB association. The YSO mass function is significantly steeper than the Salpeter IMF, and early O stars are conspicuously absent from M17 SWex. Assuming M17 SWex will form an OB association with a Salpeter IMF, these results reveal the combined effects of (1) more rapid circumstellar disk evolution in more massive YSOs and (2) delayed onset of massive star formation.

Energy Technology Data Exchange (ETDEWEB)

The flux of cosmic ray antiprotons with kinetic energies between /approximately/1 and 15 GeV is /approximately/5 times greater than the flux predicted on the basis of the leaky-box model. This excess is attributed to secondary antineutron production in compact sources. Because the antineutrons are not confined by the magnetic field of the compact source, they leave the interaction site, decay in interstellar space and account for the apparent excess cosmic ray antiproton flux. The escape and decay of neutrons produced in association with the antineutrons is a source of cosmic ray protons. Observations of the angular variation of the intensity and spectral shape of 100 MeV ..gamma..-rays produced by neutron-decay protons in the reaction p + p ..-->.. ..pi../sup 0/ ..-->.. 2..gamma.. could reveal compact-source cosmic ray production sites. COS-B observations of spectral hardening near point sources, and future high-resolution observations of galactic point ...

CERN Document Server

We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the unresolved cores. The sample includes 16 quasars (11 core-dominated and 5 lobe-dominated) in the redshift range z=0.30--1.96, and one low-power radio-galaxy at z=0.064. No diffuse X-ray emission is present around the cores of the quasars, except for the nearby low-power galaxy that has diffuse emission on a scale and with a luminosity consistent with other FRIs. No high-amplitude, short-term variability is detected within the relatively short Chandra exposures. However, 1510-089 shows low-amplitude flux changes with a timescale of $\\sim$25 minutes. The X-ray spectra of the quasar cores are generally well described by a single power law model with Galactic absorption. However, in six quasars we find soft X-ray excess ...

Energy Technology Data Exchange (ETDEWEB)

The COBE data on cosmic background radiation (CBR) isotropy and spectrum are generally considered to be explicable only in the context of the Big Bang theory and to be confirmation of that theory. However, this data can also be explained by an alternative, non-Big Bang model which hypothesizes an intergalactic radio-absorbing and scattering medium. Dense, force-free magnetic filaments generated by quasars, active galactic nuclei and Herbig-Haro objects can remain stable in the intergalactic medium for many Gy. They will be opaque to radiation with wavelengths longer than 100--400 microns, and essentially transparent to shorter wavelengths. They are thus capable of thermalizing and isotropizing the cosmic background radiation, and of accounting for the observed decrease of radio luminosity of galaxies within increasing distance from earth. A simple, inhomogeneous model of such an absorbing medium can reproduce both the isotropy and spectrum of the CBR within the ...

CERN Document Server

A variety of investigations have demonstrated commonalities between the Baldwin (1977) Effect, the blueshifting of CIV emission lines (e.g., Gaskell 1982; Richards et al. 2002), and the L_UV-L_X relationship (e.g., Avni & Tananbaum 1982; Strateva et al. 2005; Steffen et al. 2006); indeed all three of these observational effects may be manifestations of the same underlying (but still uncertain) physics. This commonality is of interest to investigations of accretion disk winds (e.g., Murray et al. 1995; Proga et al. 2000) from active galactic nuclei (AGN) as there is evidence that broad absorption line quasars (BALQSOs) are drawn from a parent sample of quasars that exhibit larger than average CIV blueshifts, weaker than average CIV emission line strengths, and bluer than average (intrinsic) colors. The properties of the absorption troughs appear to be dependent upon these parameters. Thus, it is suggested that not all quasars will host bona-fide BAL troughs, but ...

International Nuclear Information System (INIS)

This Environmental Assessment (EA) reviews the environmental consequences associated with the proposed action of granting a site use permit to construct and operate a conference center on an approximately 70-acre tract of land on the Savannah River Site (SRS). While the proposed action requires an administrative decision by DOE, this EA reviews the linked action of physically constructing and operating a conference center. The SRS is a DOE-owned nuclear production facility encompassing approximately 200,000 acres in southwestern South Carolina. The proposed conference center would have an area of approximately 4,000 square feet, and would infrequently accommodate as many as 150 people, with the average being about 20 people per day. In addition to the No-Action alternative, under which the Research Foundation would not require the 70-acre tract of SRS land for a conference center, this EA considers site ...

International Nuclear Information System (INIS)

The optical spectroscopy measurements of gadolinium gallium garnet (GGG) crystals doped with Yb show evidence of the presence of non-equivalent optical centers with very similar radiative decay rates. The energy level schemes of those centers have been determined on the basis of optical absorption, luminescence and Raman experiments. Crystal field fitting resulted in two sets of slightly different crystal field parameters for two non-equivalent Yb centers. Both sets of parameters describe perfectly the experimentally detected Y b3+ energy levels. Correlation between systematic trends in the experimental energy level schemes and crystal field parameters is discussed.

British Library Electronic Table of Contents (United Kingdom)

Post-tensioned (PT) self-centering moment frames have been developed as an alternative to typical moment-resisting frames (MRFs) for earthquake resistance. When a PT frame deforms laterally, gaps between the beams and columns open. However, the gaps are constrained by the columns and the slab in a real PT self-centering building frame. This paper presents a methodology for evaluating the column restraint and beam compression force based on the column deformation and gap openings at all stories. The method is verified by cyclic tests of a full-scale, two-bay by one-story PT frame. Moreover, a sliding slab is proposed to minimize restraints on the expansion of the PT frame. Shaking table tests were conducted on a reduced-scale, two-by-two bay one-story specimen, which comprises one PT frame ...

Energy Technology Data Exchange (ETDEWEB)

Heavy Ion Collisions at RHIC and LHC energies are potentially an interesting laboratory for the study of QED. In these collisions, a Heavy Ion in one beam sees a highly Lorentz contracted electric field due to an oncoming beam particle. The Electric field reaches a maximum value of E {approx_equal} {gamma}{sub eff} {center_dot} Z {center_dot} e/b{sup 2}, where the apparent Lorentz factor, {gamma}{sub eff} = 2 {center_dot} {gamma}{sub beam}{sup 2} - 1. The collision may be viewed in terms of a flux of photons colliding with a stationary ion target using the equivalent photon approximation, originally introduced by Fermi in 1924. We show that the cross section for Inelastic Electromagnetic Interactions of Heavy Ions are both calculable and have been measured in the first RHIC running period.

Energy Technology Data Exchange (ETDEWEB)

Southern California Gas Co.`s (SoCalGas) Energy Resource Center (ERC) in Downey, Calif. is a 45,000 ft{sup 2} (4,181 m{sup 21}) conference and education center created to help energy decision-makers find the most energy-efficient, cost-effective and environment-sensitive solutions to their energy requirements. The center has 36,000 ft{sup 2} (3,344 m{sup 2}) of remodeled space and 9,000 ft{sup 2} (836 m{sup 2}) of new space, all designed to showcase the latest energy-efficient and environment-sensitive technologies. The building is one of the 25 buildings in the US to be designated as Energy Star Showcase buildings by the US Environmental Protection Agency.

Science.gov (United States)

learning curve values as observed from data taken to plot a trend .... Log QF = Log F1 + Log F2 + Log F3 + Log F4 ffi 2.98227 . ...

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The study examines the question of whether or not civilian marketing practices and principles can be applied in the military care setting. Using the NRMC Great Lakes as a basis, the answer is yes--consumers of military medical care are ready to be the rec...

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number Fax (501) 228-3600 (501) 228-3601 Surface Water Data Information Requests Bill Baldwin (501) 228-3602 Surface Water General Information Jaysson Funkhouser (501) 228-3663...

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Dolores Beasley Headquarters, Washington, DC July 19, 2000 (Phone: 202/358- 1753) Bill Steigerwald Goddard Space Flight Center, Greenbelt, MD (Phone: ...

UK PubMed Central (United Kingdom)

In November 2002, the National Center for Healthy Housing convened a 2-day workshop to review the state of knowledge in the field of healthy housing. The workshop, supported with funds from the U.S....Full Text Available

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~4-5 times per day through a 40 Mbps Ku-band TDRSS link, while commands are uplinked on a 4 ..... During Phase 2 the budget will be ~$6M/year. Accounting ...

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Apr 20, 2009 ... "YY" is the 2-digit filter identifier .... In our example you can see a point- like optical/UV source in each of the filters at the ... The "sigma" paramter gives the detection threshold in terms of Gaussian sigma. ...

UK PubMed Central (United Kingdom)

Today, hospitals are involved extensively in social marketing and promotional activities. Recently, investigators from the Centers for Disease Control and Prevention (CDC) estimated that routine testing...Full Text Available

UK PubMed Central (United Kingdom)

This paper describes the deliverables framework developed by Vanderbilt University Medical Center (VUMC) in its IAIMS planning process. The key deliverables include: visions for the future; mission,...Full Text Available

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Sep 28, 1990 ... RCA Whirlpool builtins, gas stove and cooktop,. 998-7872. Shelly,383-7153. '77 Ford Pinto. runs, needs some work. faded red, ...

UK PubMed Central (United Kingdom)

A theoretical framework centering on four classes of self-referent constructs is offered as a device for integrating the diverse areas constituting medical sociology. Guidance by this framework...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This report for the month of June 1995 presents information on the typical topics of tritium processing, environmental studies, waste management issues, and miscellaneous projects. The document consists many small reports by individuals or small groups.

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Radiation Measurement in Crew Compartment. DTO 805: .... spacecraft and aircraft propulsion, and hazardous waste disposal. ...... combustion reactions in a turbulent chemical kinetic flow reactor using laser induced fluorescence and ...

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NASA needed a way to safely strip old paint and thermal protection material from reusable components from the Space Shuttle; to meet this requirement, Marshall Space Flight Center teamed with United Technologies' USBI Company and developed a stripping sys...

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Apr 26, 1996 ... StainlesssteelJenn-Air cooktop w/4 burners, $20. Sam,332-3168. Sale:Condo, Friendswood,3-2-2A,1411sq It,. 409-925-4862. ...

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million for advanced energy projects Thu, Sep 29, 2011 - Project Aims to Bring Bio-based Jet Fuel Production to the Northwest Mon, Sep 12, 2011 - Drive like the wind Thu, Aug 25,...

UK PubMed Central (United Kingdom)

The developing Integrated Academic Information System (IAIMS) at Columbia-Presbyterian Medical Center provides data sharing links between two separate corporate entities, namely Columbia University...Full Text Available

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loading,W/S = k. 390 og~uda per squsre foot. Total rudder movement,. Total pedal movement, 30.64?. Radius of pedel about center of rotation,. 12 inches ...

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The NS together with a gamma ray sensor make up the Gamma- Ray and ... A simplified view of the interactions between incoming cosmic rays and the .... held in Huntsville, Alabama, at the U.S. Space and Rocket Center on January 2830. ...

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Persistently high concentrations of carbon monoxide and low-altitude ozone in the air of the Nation's major urban centers led Congress in the 1990 Clean Air Act Amendments to mandate changes to the composition of gasoline and diesel fuel. Those gasoline c...

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Study of cloud pictures taken from rockets, such as figure 1, indicates that it is .... One might visualize a "Satellite Weather Data Center" where incoming data would ... about 300 miles; satellite packaging, containing the sensors, storage, power, ...

UK PubMed Central (United Kingdom)

BackgroundIn a previous study conducted at the Cesare Maltoni Cancer Research Center of the European Ramazzini Foundation (CMCRC/ERF), we demonstrated for the first time that aspartame...Full Text Available

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J. Edmunson, BAE Systems/NASA Marshall Space Flight Center (320 Sparkman Drive. VP61, Huntsville AL 35805, Jennifer.E.Edmunson@nasa.gov). ...

UK PubMed Central (United Kingdom)

PurposeIn situ fixation for mild to moderate slipped capital femoral epiphysis (SCFE) remains an acceptable treatment methodology in most centers. Satisfactory fixation results have...Full Text Available

UK PubMed Central (United Kingdom)

In 2008, a clinical information tool was developed and embedded in the electronic health record system of an academic medical center. In 2009, the initial information tool, Clinical-e, was superseded...Full Text Available

UK PubMed Central (United Kingdom)

Speech and language disorders are some of the most common referral reasons to child development centers accounting for approximately 40% of cases. Stuttering is a disorder in which involuntary...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Hydrogenolysis of quinoline was carried out using red mud catalyst at 390{degree}C and 450{degree}C to study denitrogenation reaction in the first stage liquefaction of coal. Quinoline was decomposed to ammonia via 1-THQ or hydrogenated to 5-THQ. The reaction rate constants obtained at 390{degree}C were k{sub 1} = 1.83 {times} 10{sup {minus}6}, k{sub 2} = 1.16 {times} 10{sup {minus}7}, and k{sub 3} = 3.24 {times} 10{sup {minus}7} mol {center dot} dm{sup {minus}3} {center dot} min{sup {minus}1} {center dot} g {center dot} {sup {minus}1}. The rate constants for hydrogenation of quinoline were in the order of hexadecane > trans-decalin > 1-methylnaphthalene. Ratios of equilibrium adsorption constant between trans-decalin and quinoline and between 1-methylnaphthalene and quinoline were found to be 0.055 and 0.155 respectively. The equilibrium constant of phenol to red mud catalyst adsorption was ...

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Oct 23, 1992 ... washer, water heater, cooktop, roof, fence, sunroof, auto, 81K mi, runs ok, $2.5 K OBO. x39282 or 335-0641. Want a lucit carpet protector 54" ...

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tact materials ate Ti-Pd-Ag and the back surface reflector is formed from evaporated .... Ti-Pd-Ag, Dielectric Wraparound. BSR. Evaporated Aluminum ...

UK PubMed Central (United Kingdom)

Giardiasis is recognized as a worldwide public health problem. Seroprevalence data from both the developing and developed world show high rates of carriage in populations at risk for fecal-oral transmission,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Thermal, electrical, and electrochemical properties were investigated for the (100-x)(0.6Li{sub 2}S{center{underscore}dot}0.4SiS{sub 2}){center{underscore}dot}xLi{sub 4}SiO{sub 4} oxysulfide glasses. The glass with x = 5 exhibited high electrical conductivity of about 10{sup {minus}3} S cm{sup {minus}1} at room temperature, high glass stability against crystallization, and good chemical stability in contact with Li metal. Cyclic voltammetry also suggested that this glass has a wide electrochemical window of more than 10 V. On the other hand, further addition of Li{sub 4}SiO{sub 4} up to 20 mol% lowered the conductivity, glass stability against crystallization, and electrochemical stability for the oxysulfide glasses.

UK PubMed Central (United Kingdom)

Background:The minimum hemoglobin cutoff for blood donation in India is 12.5 gm% for both male and female donors and the minimum donation interval is 3 months. Donation...Full Text Available

CERN Multimedia

Since 50 years, the scientists in European Center for Nuclear Research in Geneva, are looking for the secrets of the nature. Their standard Model would explains a lot of things; but the single question "What is the mass?" still does not have an answer

Energy Technology Data Exchange (ETDEWEB)

Cooperative research in coal liquefaction from Auburn University, University of Kentucky, University of Pittsburgh, West Virginia University, University of Utah, and the UK Center for Applied Energy Research, are briefly discussed. Topics covered include desulfurization, chemical reactivity, coprocessing, and catalysis. (CBS)

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These steps are based on work done by the AIAA. Space-Based Observation Systems Committee on Standards (SBOS COS) as well as work done in this ..... Surface Weapons Center, Code B-10, Dahlgren, VA, 22448. Although it had many ...

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is approximately 327000 km from the Earth's center (58000 km from the Moon's ...... source (figure 7-4). NEXT developed funding requirements for those ...... Code SF 2. 2101 NASA Rd. 1. Houston, TX 77058. Phone: (281) 483-7224 ...

UK PubMed Central (United Kingdom)

The biomechanical nature of the arterial system and its major disease states provides a series of challenges to treatment strategies. Endovascular device design objectives have mostly centered on short-term...Full Text Available

UK PubMed Central (United Kingdom)

Abstract This paper focuses on the basic principles of information technology (IT) organization within health sciences centers. The paper considers the placement of the leader of the...Full Text Available

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Sep 9, 2009 ... You are here: GES DISC Home Geomorphology from Space By Location Landforms by Location: Asia. Info. Landforms by Location: Asia. KEY, ASIA ...

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Space Telescope is six years old today! Tomorrow's picture: In the Center of the Whirlpool | Archive | Index | Search | Glossary | Education | About APOD | See Explanation....

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Black Hole Drawing Credit: April Hobart, CXC Explanation: In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole....

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Black Hole Drawing Credit: A. Hobart, CXC Explanation: In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole....

UK PubMed Central (United Kingdom)

BackgroundThe ACTION study (Attention deficit hyperactivity disorder Controlled Trial Investigation Of a Non-stimulant) is a multi-center, double-blind, randomized...Full Text Available

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42 Public Health 3 2010-10-01 2010-10-01 false Health benefits plan: Supplemental health services. 417.102 Section 417.102 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF...

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May 31, 2011 ... Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [Clln(SCH2(CO)O)2]2-[(4-MepyH)2]2+. 284. System Mass ...

Science.gov (United States)

With the help of self-assembly, thermal sintering, selective etching techniques and sol-gel process, the non-close packed (ncp) face-centered cubic (fcc) photonic crystals of titanium dioxide (TiO2) hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The photonic bandgap calculations indicate that the ncp structure of TiO2 hollow spheres was easier to open the pseudogaps than close packed system at the lowest energy. PMID:17097102

International Nuclear Information System (INIS)

The study of imported ceramics found in Beirut and suspected to belong to north Syrian products will provide key evidence for the roles in trade of the various postulated centers in northern Syria and northern Lebanon. It is proposed that a comprehensive range of likely north Syrian products imported to Beirut will be chemically analyzed by PIXE (proton induced X-ray emission) in order to characterize, compare and isolate the various regional production centers that supplied the city from the Persian to Byzantine periods. In this work, we were mainly focusing on the characterization of Amrit products, by using 3 MeV proton beam and Al funny filter, as X-ray absorber.

International Nuclear Information System (INIS)

This article considers the application of simple trial wave functions to calculate the ground state energy of a hydrogen-like center near the interface of two media. Calculations have been performed taking into account the image potential. It has been shown that different kinds of wave functions are optimal at different distances from the interface. A relatively simple wave function has been suggested to represent main features of the dependence of the ground state energy on the distance to the interface. (authors)

Energy Technology Data Exchange (ETDEWEB)

For the determination of top dead center (TDC) of a running engine a measuring system using microwaves was developed by AEG and Volkswagen AG. The measuring method utilizes the Doppler shift of the microwaves, which were reflected at the up and down moving piston, and the varying resonance properties of the combustion chamber. The system works with a frequency of 61.4 GHz and can be used as well for spark ignition as form compression ignition engines, particularly for direct injection engines. The output signal is symmetrical to TDC. For data acquisition and data processing, i.e. the calculation of the point of symmetry, the computer system FARES is used in a special assembly.

Energy Technology Data Exchange (ETDEWEB)

In this paper we discuss the results of thermoluminescence (TL) studies carried out on freshly quenched crystals of KBr doped with {approx} 50 ppm of Eu{sup 2+} ions which were X-irradiated at room temperature. The TL glow curve of this phosphor material consists of three glow peaks at 355, 376 and 398 K whose intensities increased as a function of X-irradiation time. The TL glow peaks were analyzed by the total curve-fitting method in order to obtain the characteristic parameters; activation energy, pre-exponential factor and kinetic order. The spectral character of the emission recorded during thermoluminescence was found to be the same for all glow peaks and consists of a broad band centered at {approx} 420 nm. It is proposed that the model of the TL process most consistent with our experimental results is one in which the Eu{sup 2+} impurity acts as an electron trap during the irradiation process and that the radiation induced center ...

Energy Technology Data Exchange (ETDEWEB)

The EPA has designated vitrification as the best developed available technology for immobilization of High-Level Nuclear Waste. In a recent federal facilities compliance agreement between the EPA, the State of Washington, and the DOE, the DOE agreed to vitrify all of the Low Level Radioactive Waste resulting from processing of High Level Radioactive Waste stored at the Hanford Site. This is expected to result in the requirement of 100 ton per day Low Level Radioactive Waste melters. Thus, there is increased need for the rapid adaptation of commercial melter equipment to DOE`s needs. DOE has needed a facility where commercial pilot scale equipment could be operated on surrogate (non-radioactive) simulations of typical DOE waste streams. The DOE/Industry Center for Vitrification Research (Center) was established in 1992 at the Clemson University Department of Environmental Systems Engineering, Clemson, SC, to address that need. This report ...

Energy Technology Data Exchange (ETDEWEB)

Collective dose equivalent and population dose from occupational exposures in Japan, 1988 were estimated on the basis of a nationwide survey. The survey was conducted on annual collective dose equivalents by sex, age group and type of radiation work for about 0.21 million workers except for the workers in nuclear power stations. The data on the workers in nuclear power stations were obtained from the official report of the Japan Nuclear Safety Commission. The total number of workers including nuclear power stations was estimated to be about 0.26 million. Radiation works were subdivided as follows: medical works including dental; non-atomic energy industry; research and education; atomic energy industry and nuclear power station. For the determination of effective dose equivalent and population dose, organ or tissue doses were measured with a phantom experiment. The resultant doses were compared with the doses previously calculated using a chord length technique and with data from ICRP ...

International Nuclear Information System (INIS)

We study the line widths in the [O III]#lambda#5007 and H#alpha# lines for two groups of planetary nebulae in the Milky Way bulge based upon spectroscopy obtained at the Observatorio Astronomico Nacional in the Sierra San Pedro Martir (OAN-SPM) using the Manchester Echelle Spectrograph. The first sample includes objects early in their evolution, having high H#beta# luminosities, but [O III]#lambda#5007/H#beta# < 3. The second sample comprises objects late in their evolution, with He II #lambda#4686/H#beta#>0.5. These planetary nebulae represent evolutionary phases preceding and following those of the objects studied by Richer et al. in 2008. Our sample of planetary nebulae with weak [O III]#lambda#5007 has a line width distribution similar to that of the expansion velocities of the envelopes of asymptotic giant branch stars and shifted to systematically lower values as compared to the less evolved objects studied by Richer et al. The sample with strong He II #lambda#4686 has a ...

International Nuclear Information System (INIS)

We study the dynamical evolution of globular clusters containing primordial binaries, including full single and binary stellar evolution using our Monte Carlo cluster evolution code updated with an adaptation of the single and binary stellar evolution codes SSE and BSE from Hurley et al. We describe the modifications that we have made to the code. We present several test calculations and comparisons with existing studies to illustrate the validity of the code. We show that our code finds very good agreement with direct N-body simulations including primordial binaries and stellar evolution. We find significant differences in the evolution of the global properties of the simulated clusters using stellar evolution compared with simulations without any stellar evolution. In particular, we find that the mass loss from the stellar evolution acts as a significant energy production channel simply by reducing the total gravitational binding energy and can significantly prolong the initial core ...

Energy Technology Data Exchange (ETDEWEB)

I present a promising route to harmonize distance measurements based on clump giants and RR Lyrae stars. This is achieved by comparing the brightness of these distance indicators in three environments: the solar neighborhood, Galactic bulge and Large Magellanic Cloud (LMC). As a result of harmonizing the distance scales in the solar neighborhood and Baade's Window, I derive the new absolute magnitude of RR Lyrae stars, M{sub v}(RR) at [Fe/H] = -1.6 (0.59 {+-} 0.05, 0.70 {+-} 0.05). Being somewhat brighter than the statistical parallax solution, but fainter than typical results of the main sequence fitting to Hipparcos data, these values of M{sub V}(RR) favor intermediate or old ages of globular clusters. Harmonizing the distance scales in the LMC and Baade's Window, I show that the most likely distance modulus to the LMC, {mu}{sub LMC} is in the range 18.24 - 18.44. The Hubble constant of about 70 km/s/Mpc reported by the HST Key Project is based ...