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Sample records for background explorer cobe

  1. Cosmic Background Explorer (COBE): Emergency support

    Science.gov (United States)

    Stanford, R.; Mattson, R.

    1991-01-01

    The Cosmic Background Explorer (COBE) Mission will measure the diffuse radiation from the universe in the wavelength band 1 micron to 9.6 mm. The band includes the 3 K cosmic background radiation, the known relic of the primeval cosmic explosion. The COBE satellite will be launched from the Western Space and Missile Center (EWSMC) via a Delta launch vehicle into a circular parking orbit of about 300 km. COBE will be placed into a 900-km altitude circular orbit. Coverage will be provided by the Deep Space Network (DSN) for COBE emergencies that would prevent communications via the normal channels of the Tracking and Data Relay Satellite System (TDRSS). Emergency support will be provided by the DSN 26-m subnetwork. Information is given in tabular form for DSN network support, frequency assignments, telemetry, and command.

  2. Optical alignments of the Cosmic Background Explorer (COBE) observatory

    Science.gov (United States)

    Sampler, Henry P.

    1990-01-01

    The angular alignments and stabilities of multiple components in a single coordinate system were determined using various alignment tooling techniques. These techniques use autocollimation measurements with a first order theodolite and transformation of coordinates to determine the relative alignment between various components with respect to a common set of COBE spacecraft coordinate axes. Optical-mechanical alignment techniques were also used to integrate the flight COBE observatory attitude control system module that consists of gyros, reaction wheels, and a momentum wheel. Particular attention is given to the techniques for alignments and stabilities of the earth scanners, sun sensors, far IR absolute spectrophotometer, Diffuse Infrared Background Experiment, and differential microwave radiometer antenna horn boresights.

  3. Cosmic Background Explorer (COBE) transfer orbit attitude control system

    Science.gov (United States)

    Placanica, Samuel J.; Flatley, Thomas W.

    1986-01-01

    The Cosmic Background Explorer (COBE) spacecraft will be launched by the Shuttle from Vandenberg AFB into a 300 km altitude, 99 deg inclination, 6 a.m. or 6 p.m. ascending node orbit. After release from the Remote Manipulator System (RMS) arm, an on-board monopropellant hydrazine propulsion system will raise the orbit altitude to 900 km. The spacecraft continuously spins during transfer orbit operations with the spin axis nominally horizontal and in or near the orbit plane. The blowdown propulsion system consists of twelve 5 lb thrusters (3 'spin', 3 'despin', and 6 'axial') with the latter providing initially 30 lb of force parallel to the spin axis for orbit raising. The spin/despin jets provide a constant roll rate during the transfer orbit phase of the mission and the axials control pitch and yaw. The axial thrusters are pulsed on for attitude control during coast periods and are normally on- and off-modulated for control during orbit raising. Attitude sensors employed in the control loops include an array of two-axis digital sun sensors and three planar earth scanners for position measurements, as well as six gyroscopes for rate information. System redundancy is achieved by means of unique three-axes-in-a-plane geometry. This triaxial concept results in a fail-safe operational system with no performance degradation for many different component failure modes.

  4. Early results from the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Mather, J. C.; Hauser, M. G.; Bennett, C. L.; Boggess, N. W.; Cheng, E. S.; Eplee, R. E., Jr.; Freudenreich, H. T.; Isaacman, R. B.; Kelsall, T.; Gulkis, S.

    1991-01-01

    Data obtained with the FIR Absolute Spectrophotometer, Differential Microwave Radiometers, and Diffuse IR Background Experiment (DIRBE) on the COBE satellite since its launch in November 1989 are briefly characterized. The COBE spacecraft and its 900-km 99-deg orbit are described; the scientific goals and capabilities of the instruments are reviewed; and sample DIRBE data are presented in a map and graph. Upper limits on the Comptonization parameter (y less than 0.001) and the chemical potential (mu less than 0.01 at the 3sigma level) are determined, and the spectrum of the dipole anisotropy is shown to be that of a Doppler-shifted blackbody. The DIRBE 100-micron sky brightness values at the ecliptic poles are found to be significantly lower than those measured by IRAS.

  5. Science objectives lead to contamination requirements for the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Abrams, Eve M.; Carosso, Nancy J. P.

    1990-01-01

    The mission aims and related requirements of the Cosmic Background Explorer (COBE) are described in order to assess the measure needed for adequate control of optical system contamination. Instrument requirements are set forth so that the Diffuse IR Background Experiment (DIRBE), the Far IR Absolute Spectrophotometer (FIRAS), and the Differential Microwave Radiometers (DMRs) can achieve performance goals. The BRDF requirement for the primary mirror of the DIRBE is a maximum change of 50 percent on clean versus contaminated mirrors. The most critical components of the FIRAS and the DMR are discussed which are the sky horn and the antennae throats, respectively. The contamination-control devices include contamination covers, cleanroom assembly, and retractable cover assembly. The COBE is not found to perform unreliably due to contamination problems which suggests that the contamination program is effective.

  6. Cryogenic Optical Assembly (COA) cooldown analysis for the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Coladonato, Robert J.; Irish, Sandra M.; Mosier, Carol L.

    1990-01-01

    The Cosmic Background Explorer (COBE) spacecraft, developed by Goddard Space Flight Center (GSFC), was successfully launched on November 18, 1989 aboard a Delta expendable launch vehicle. Two of the three instruments for this mission were mounted inside a liquid helium (LHe) dewar which operates at a temperature of 2 K. These two instruments are the Diffuse Infrared Background Experiment (DIRBE) and the Far Infrared Absolute Spectrophotometer (FIRAS). They are mounted to a common Instrument Interface Structure (IIS) and the entire assembly is called the Cryogenic Optical Assembly (COA). As part of the structural verification requirement, it was necessary to show that the entire COA exhibited adequate strength and would be capable of withstanding the launch environment. This requirement presented an unique challenge for COBE because the COA is built and assembled at room temperature (300 K), cooled to 2 K, and then subjected to launch loads. However, strength testing of the entire COA at 2 K could not be done because of facility limitations. Therefore, it was decided to perform the strength verification of the COA by analysis.

  7. An overview of the Cosmic Background Explorer (COBE) and its observations - New sky maps of the early universe

    Science.gov (United States)

    Smoot, George F.

    1992-01-01

    This paper discusses the three instruments aboard NASA's Cosmic Background Explorer (COBE) satellite and presents early results obtained from the first six months of observations. The three instruments (FIRAS, DMR, and DIRBE) have operated well and produced significant new results. The FIRAS measurement of the CMB spectrum supports the standard Big Bang model. The maps made from the DMR instrument measurements show a spatially smooth early universe. The maps of galactic and zodiacal emission produced by the DIRBE instrument are needed to identify the foreground emissions from extragalactic and thus to interpret its and the other COBE results in terms of events in the early universe.

  8. On-orbit attitude control of the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Bramberg, B.; Croft, J.

    1985-01-01

    The way in which COBE (launched by the SS in late 1982) performs its attitude control is described, along with the design of its on-orbit system. COBE, to be situated in a 900 km high, sun-synchronous orbit, contains two unique control features: (1) the orientation of the spinning satellite is controlled to a sun-normal attitude in the sun/local vertical plane; and (2) pitch and roll control is maintained by a unique triaxial arrangement of reaction wheels, magnetic torque bars and sensors, located in the body's tranverse plane. Inherent in this triaxial configuration concept is a built-in redundancy that will maintain attitude control in the event of any single-point sensor/actuator component failure. Each of the three control drive electronics operates independently and directly of a system of dedicated sensors. This system functions independently of a computer or an ephemeris communication link, leading to greater reliability.

  9. One-way return-link Doppler navigation with the Tracking and Data Satellite System (TDRSS) - The ultrastable oscillator (USO) experiment on the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Dunham, J. B.; Nemesure, M.; Teles, J.; Brown-Conwell, E. R.; Jackson, J. A.; Reamy, V. L.; Maher, M. J.; Elrod, B. D.

    1990-01-01

    The principal objectives of the USO experiment on the COBE spacecraft are defined, and results of space qualification studies for the COBE USO experiment are summarized. The principal objectives of the experiment are: (1) to determine flight performance of the USO coupled to the second-generation TDRSS transponder; (2) space qualify TDRSS noncoherent one-way return-link Doppler tracking; and (3) analyze algorithms for one-way navigation with real data. The three objectives of the experiment have been met in the first stage of the experiment analysis.

  10. Limits on the cosmic infrared background from clustering in COBE/DIRBE maps

    CERN Document Server

    Kashlinsky, A; Odenwald, S

    1997-01-01

    We discuss a new method of estimating the cosmic infrared background (CIB) from the spatial properties of infrared maps and give the limits on the CIB from applying it to the COBE/DIRBE maps. The strongest limits are obtained at mid- to far-IR where foregrounds are bright, but smooth. If the CIB comes from matter clustered like galaxies, the smoothness of the maps implies CIB levels less than $\\sim$(10-15) nW/m$^2$/sr over this wavelength range.

  11. Cold dark matter and degree-scale cosmic microwave background anisotropy statistics after COBE

    Science.gov (United States)

    Gorski, Krzysztof M.; Stompor, Radoslaw; Juszkiewicz, Roman

    1993-01-01

    We conduct a Monte Carlo simulation of the cosmic microwave background (CMB) anisotropy in the UCSB South Pole 1991 degree-scale experiment. We examine cold dark matter cosmology with large-scale structure seeded by the Harrison-Zel'dovich hierarchy of Gaussian-distributed primordial inhomogeneities normalized to the COBE-DMR measurement of large-angle CMB anisotropy. We find it statistically implausible (in the sense of low cumulative probability F lower than 5 percent, of not measuring a cosmological delta-T/T signal) that the degree-scale cosmological CMB anisotropy predicted in such models could have escaped a detection at the level of sensitivity achieved in the South Pole 1991 experiment.

  12. COBE looks back to the Big Bang

    Science.gov (United States)

    Mather, John C.

    1993-01-01

    An overview is presented of NASA-Goddard's Cosmic Background Explorer (COBE), the first NASA satellite designed to observe the primeval explosion of the universe. The spacecraft carries three extremely sensitive IR and microwave instruments designed to measure the faint residual radiation from the Big Bang and to search for the formation of the first galaxies. COBE's far IR absolute spectrophotometer has shown that the Big Bang radiation has a blackbody spectrum, proving that there was no large energy release after the explosion.

  13. A Study of External Galaxies Detected by the COBE Diffuse Infrared Background Experiment

    International Nuclear Information System (INIS)

    A comparison of the COBE Diffuse Infrared Background Experiment (DIRBE) all-sky survey with the locations of known galaxies in the IRAS Catalog of Extragalactic Objects and the Center for Astrophysics Catalog of Galaxies led to the detection of as many as 57 galaxies. In this paper, we present the photometric data for these galaxies and an analysis of the seven galaxies that were detected at λ > 100 μm. Estimates of the ratio of the mass of the cold dust (CD) component detected at Td = 20 endash 30 K to a very cold dust (VCD) component with Td ∼ 10 endash 15 K suggest that between 2%endash 100% of the cirrus-like CD mass can also exist in many of these galaxies as VCD. In one galaxy, M33, the DIRBE photometry at 240 μm suggests as much as 26 times as much VCD may be present as compared to the cirrus-like component. Further submillimeter measurements of this galaxy are required to verify such a large population of VCD. We also present 10 galaxies that were detected in the sky region not previously surveyed by IRAS and that can be used to construct a flux-limited all-sky catalog of galaxies brighter than 1000 Jy with a modest completeness limit of about 65%. copyright copyright 1998. The American Astronomical Society

  14. Summary of Results from COBE

    OpenAIRE

    Smoot, George F.

    1999-01-01

    This work presents a summary of major cosmological results from the COBE (Cosmic Background Explorer) satellite mission. The results include a precise measurement of the Cosmic Microwave Background (CMB) radiation intensity, discovery and maps of the CMB anisotropy, large scale observations of the CMB polarization, and the detection and measurement of the diffuse infrared background. This summary was occassioned by and is part of the proceedings for the 3K Cosmology Conference held at Rome in...

  15. Summary of Results from COBE

    CERN Document Server

    Smoot, G F

    1999-01-01

    This work presents a summary of major cosmological results from the COBE (Cosmic Background Explorer) satellite mission. The results include a precise measurement of the Cosmic Microwave Background (CMB) radiation intensity, discovery and maps of the CMB anisotropy, large scale observations of the CMB polarization, and the detection and measurement of the diffuse infrared background. This summary was occassioned by and is part of the proceedings for the 3K Cosmology Conference held at Rome in October 1998.

  16. On the radiative and thermodynamic properties of the Cosmic Microwave Background radiation using COBE FIRAS instrument data

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Use formulas to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, pressure, enthalpy density, and internal energy density in the finite range of frequencies are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.728 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant are calculated. In the case of the dipole spectrum, the constants a and the Stefan-Bol...

  17. Exploring String Theory Backgrounds

    CERN Document Server

    Williams, B P

    2004-01-01

    This thesis examines phenomenological and theoretical questions by exploring string theoretic backgrounds. Part I focuses on cosmology. First we propose that the induced metric along a brane moving through a curved bulk may be interpreted as the cosmology of the brane universe, providing a resolution to the apparent cosmological singularity on the brane. We then look at various decay channels of the certain meta-stable de Sitter vacua and show that there exist NS5-brane meditated decays which are much faster than decays to decompactification. Part II discusses a new class of nongeometric vacua in string theory. These backgrounds may be described locally as T2 fibrations. By enlarging the monodromy group of the fiber to include perturbative stringy duality symmetries we are able to explicitly construct nongeometric backgrounds.

  18. COBE experience with filter QUEST

    Science.gov (United States)

    Filla, O.; Keat, J.; Chu, D.

    1991-10-01

    A gyro based filter variation on the standard QUEST attitude determination algorithm is applied to the Cosmic Background Explorer (COBE). Filter QUEST is found to be three times as fast as the batch estimator and slightly more accurate than regular QUEST. Perhaps more important than its speed or accuracy is the fact that Filter QUEST can provide real time attitude solutions when regular QUEST cannot, due to lack of observability. Filter QUEST is also easy to use and adjust for the proper memory length. Suitable applications for Filter QUEST include coarse and real time attitude determination.

  19. COBE's search for structure in the Big Bang

    Science.gov (United States)

    Soffen, Gerald (Editor); Guerny, Gene (Editor); Keating, Thomas (Editor); Moe, Karen (Editor); Sullivan, Walter (Editor); Truszkowski, Walt (Editor)

    1989-01-01

    The launch of Cosmic Background Explorer (COBE) and the definition of Earth Observing System (EOS) are two of the major events at NASA-Goddard. The three experiments contained in COBE (Differential Microwave Radiometer (DMR), Far Infrared Absolute Spectrophotometer (FIRAS), and Diffuse Infrared Background Experiment (DIRBE)) are very important in measuring the big bang. DMR measures the isotropy of the cosmic background (direction of the radiation). FIRAS looks at the spectrum over the whole sky, searching for deviations, and DIRBE operates in the infrared part of the spectrum gathering evidence of the earliest galaxy formation. By special techniques, the radiation coming from the solar system will be distinguished from that of extragalactic origin. Unique graphics will be used to represent the temperature of the emitting material. A cosmic event will be modeled of such importance that it will affect cosmological theory for generations to come. EOS will monitor changes in the Earth's geophysics during a whole solar color cycle.

  20. COBE: A Radiological Analysis

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-10-01

    Full Text Available The COBE Far Infrared Absolute Spectrophotometer (FIRAS operated from ~30 to ~3,000 GHz (1-95 cm$^{-1}$ and monitored, from polar orbit (~900 km, the ~3 K microwave background. Data released from FIRAS has been met with nearly universal admiration. However, a thorough review of the literature reveals significant problems with this instrument. FIRAS was designed to function as a differential radiometer, wherein the sky signal could be nulled by the reference horn, Ical. The null point occurred at an Ical temperature of 2.759 K. This was 34 mK above the reported sky temperature, 2.725$pm$0.001 K, a value where the null should ideally have formed. In addition, an 18 mK error existed between the thermometers in Ical, along with a drift in temperature of ~3 mK. A 5 mK error could be attributed to Xcal; while a 4 mK error was found in the frequency scale. A direct treatment of all these systematic errors would lead to a ~64 mK error bar in the microwave background temperature. The FIRAS team reported ~1 mK, despite the presence of such systematic errors. But a 1 mK error does not properly reflect the experimental state of this spectrophotometer. In the end, all errors were essentially transferred into the calibration files, giving the appearance of better performance than actually obtained. The use of calibration procedures resulted in calculated Ical emissivities exceeding 1.3 at the higher frequencies, whereas an emissivity of 1 constitutes the theoretical limit. While data from 30-60 GHz was once presented, these critical points are later dropped, without appropriate discussion, presumably because they reflect too much microwave power. Data obtained while the Earth was directly illuminating the sky antenna, was also discarded. From 300-660 GHz, initial FIRAS data had systematically growing residuals as frequencies increased. This suggested that the signal was falling too quickly in the Wien region of the spectrum. In later data releases, the

  1. COBE: A Radiological Analysis

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-10-01

    Full Text Available The COBE Far Infrared Absolute Spectrophotometer (FIRAS operated from 30 to 3,000 GHz (1–95 cm -1 and monitored, from polar orbit ( 900 km, the 3 K mi- crowave background. Data released from FIRAS has been met with nearly universal ad- miration. However, a thorough review of the literature reveals significant problems with this instrument. FIRAS was designed to function as a differential radiometer, wherein the sky signal could be nulled by the reference horn, Ical. The null point occurred at an Ical temperature of 2.759 K. This was 34 mK above the reported sky temperature, 2.725 0.001 K, a value where the null should ideally have formed. In addition, an 18 mK error existed between the thermometers in Ical, along with a drift in temper- ature of 3 mK. A 5 mK error could be attributed to Xcal; while a 4 mK error was found in the frequency scale. A direct treatment of all these systematic errors would lead to a 64 mK error bar in the microwave background temperature. The FIRAS team reported 1 mK, despite the presence of such systematic errors. But a 1 mK er- ror does not properly reflect the experimental state of this spectrophotometer. In the end, all errors were essentially transferred into the calibration files, giving the appear- ance of better performance than actually obtained. The use of calibration procedures resulted in calculated Ical emissivities exceeding 1.3 at the higher frequencies, whereas an emissivity of 1 constitutes the theoretical limit. While data from 30–60 GHz was once presented, these critical points are later dropped, without appropriate discussion, presumably because they reflect too much microwave power. Data obtained while the Earth was directly illuminating the sky antenna, was also discarded. From 300–660 GHz, initial FIRAS data had systematically growing residuals as frequencies increased. This suggested that the signal was falling too quickly in the Wien region of the spec- trum. In later data

  2. Interpretation of the COBE FIRAS CMBR spectrum

    Science.gov (United States)

    Wright, E. L.; Mather, J. C.; Fixsen, D. J.; Kogut, A.; Shafer, R. A.; Bennett, C. L.; Boggess, N. W.; Cheng, E. S.; Silverberg, R. F.; Smoot, G. F.

    1994-01-01

    The cosmic microwave background radiation (CMBR) spectrum measured by the Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on NASA's Cosmic Background Explorer (COBE) is indistinguishable from a blackbody, implying stringent limits on energy release in the early universe later than the time t = 1 yr after the big bang. We compare the FIRAS data to previous precise measurements of the cosmic microwave background spectrum and find a reasonable agreement. We discuss the implications of the absolute value of y is less than 2.5 x 10(exp -5) and the absolute value of mu is less than 3.3 x 10(exp -4) 95% confidence limits found by Mather et al. (1994) on many processes occurring after t = 1 yr, such as explosive structure formation, reionization, and dissipation of small-scale density perturbations. We place limits on models with dust plus Population III stars, or evolving populations of IR galaxies, by directly comparing the Mather et al. spectrum to the model predictions.

  3. Can the Gravitational Wave Background from Inflation be Detected Locally?

    OpenAIRE

    Liddle, Andrew R.

    1993-01-01

    The Cosmic Background Explorer (COBE) detection of microwave background anisotropies may contain a component due to gravitational waves generated by inflation. It is shown that the gravitational waves from inflation might be seen using `beam-in-space' detectors, but not the Laser Interferometer Gravity Wave Observatory (LIGO). The central conclusion, dependent only on weak assumptions regarding the physics of inflation, is a surprising one. The larger the component of the COBE signal due to g...

  4. Large-scale structure after COBE: Peculiar velocities and correlations of cold dark matter halos

    Science.gov (United States)

    Zurek, Wojciech H.; Quinn, Peter J.; Salmon, John K.; Warren, Michael S.

    1994-01-01

    Large N-body simulations on parallel supercomputers allow one to simultaneously investigate large-scale structure and the formation of galactic halos with unprecedented resolution. Our study shows that the masses as well as the spatial distribution of halos on scales of tens of megaparsecs in a cold dark matter (CDM) universe with the spectrum normalized to the anisotropies detected by Cosmic Background Explorer (COBE) is compatible with the observations. We also show that the average value of the relative pairwise velocity dispersion sigma(sub v) - used as a principal argument against COBE-normalized CDM models-is significantly lower for halos than for individual particles. When the observational methods of extracting sigma(sub v) are applied to the redshift catalogs obtained from the numerical experiments, estimates differ significantly between different observation-sized samples and overlap observational estimates obtained following the same procedure.

  5. The COBE normalization for standard cold dark matter

    Science.gov (United States)

    Bunn, Emory F.; Scott, Douglas; White, Martin

    1995-01-01

    The Cosmic Background Explorer Satellite (COBE) detection of microwave anisotropies provides the best way of fixing the amplitude of cosmological fluctuations on the largest scales. This normalization is usually given for an n = 1 spectrum, including only the anisotropy caused by the Sachs-Wolfe effect. This is certainly not a good approximation for a model containing any reasonable amount of baryonic matter. In fact, even tilted Sachs-Wolfe spectra are not a good fit to models like cold dark matter (CDM). Here, we normalize standard CDM (sCDM) to the two-year COBE data and quote the best amplitude in terms of the conventionally used measures of power. We also give normalizations for some specific variants of this standard model, and we indicate how the normalization depends on the assumed values on n, Omega(sub B) and H(sub 0). For sCDM we find the mean value of Q = 19.9 +/- 1.5 micro-K, corresponding to sigma(sub 8) = 1.34 +/- 0.10, with the normalization at large scales being B = (8.16 +/- 1.04) x 10(exp 5)(Mpc/h)(exp 4), and other numbers given in the table. The measured rms temperature fluctuation smoothed on 10 deg is a little low relative to this normalization. This is mainly due to the low quadrupole in the data: when the quadrupole is removed, the measured value of sigma(10 deg) is quite consistent with the best-fitting the mean value of Q. The use of the mean value of Q should be preferred over sigma(10 deg), when its value can be determined for a particular theory, since it makes full use of the data.

  6. The Big Bang, COBE, and the Relic Radiation of Creation (LBNL Science at the Theater)

    Energy Technology Data Exchange (ETDEWEB)

    Smoot, George

    2007-03-05

    Berkeley Lab's George Smoot won the 2006 Physics Nobel Prize, together with John Mather of NASA Goddard Space Flight Center, for "the discovery of the blackbody form and anisotropy of the cosmic microwave background radiation." The anisotropy showed as small variations in the map of the early universe. This research looks back into the infant universe and provides a better understanding of the origin of galaxies and stars. The cosmic background radiation is a tool to understand the structure and history of the universe and the structure of space-time. These observations have provided increased support for the big bang theory of the universe's origin. The Cosmic Background Explorer (COBE) NASA satellite, launched in 1989, carries instruments that measured various aspects of cosmic microwave background radiation, and produced the data for these compelling scientific results, which opened up a field that continues very actively today.

  7. Inflation after COBE: Lectures on inflationary cosmology

    International Nuclear Information System (INIS)

    In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge-a detailed understanding of the formation of structure in the Universe. I then discuss the motivations for and the fundamentals of inflationary cosmology, particularly emphasizing the quantum origin of metric (density and gravity-wave) perturbations. Inflation addresses the shortcomings of the standard cosmology and provides the ''initial data'' for structure formation. I conclude by addressing the implications of inflation for structure formation, evaluating the various cold dark matter models in the light of the recent detection of temperature anisotropies in the cosmic background radiation by COBE. In the near term, the study of structure formation offers a powerful probe of inflation, as well as specific inflationary models

  8. Inflation after COBE: Lectures on inflationary cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S. [Chicago Univ., IL (United States). Enrico Fermi Inst.]|[Fermi National Accelerator Lab., Batavia, IL (United States)

    1992-12-31

    In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge-a detailed understanding of the formation of structure in the Universe. I then discuss the motivations for and the fundamentals of inflationary cosmology, particularly emphasizing the quantum origin of metric (density and gravity-wave) perturbations. Inflation addresses the shortcomings of the standard cosmology and provides the ``initial data`` for structure formation. I conclude by addressing the implications of inflation for structure formation, evaluating the various cold dark matter models in the light of the recent detection of temperature anisotropies in the cosmic background radiation by COBE. In the near term, the study of structure formation offers a powerful probe of inflation, as well as specific inflationary models.

  9. Cosmic background radiation anisotropy in an open inflation, cold dark matter cosmogony

    Science.gov (United States)

    Kamionkowski, Marc; Ratra, Bharat; Spergel, David N.; Sugiyama, Naoshi

    1994-01-01

    We compute the cosmic background radiation anisotropy, produced by energy-density fluctuations generated during an early epoch of inflation, in an open cosmological model based on the cold dark matter scenario. At Omega(sub 0) is approximately 0.3-0.4, the Cosmic Background Explorer (COBE) normalized open model appears to be consistent with most observations.

  10. COBE DIRBE near-infrared polarimetry of the zodiacal light: Initial results

    Science.gov (United States)

    Berriman, G. B.; Boggess, N. W.; Hauser, M. G.; Kelsall, T.; Lisse, C. M.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F.

    1994-01-01

    This Letter describes near-infrared polarimetry of the zodiacal light at 2.2 micrometers, measured with the Diffuse Infrared Background Experiment (DIRBE) aboard the Cosmic Background Explorer (COBE) spacecraft. The polarization is due to scattering of sunlight. The polarization vector is perpendicular to the scattering plane, and its observed amplitude on the ecliptic equator at an elongation of 90 deg and ecliptic longitude of 10 deg declines from 12.0 +/- 0.4% at 1.25 micrometers to 8.0 +/- 0.6% at 3.5 micrometers (cf. 16% in the visible); the principal source of uncertainty is photometric noise due to stars. The observed near-infrared colors at this location are redder than Solar, but at 3.5 micrometers this is due at least in part to the thermal emission contribution from the interplanetary dust. Mie theory calculations show that both polarizations and colors are important in constraining models of interplanetary dust.

  11. A Study of External Galaxies Detected by COBE-DIRBE

    OpenAIRE

    Odenwald, Sten; Newmark, Jeffrey; Smoot, George

    1996-01-01

    A comparison of the COBE, Diffuse Infrared Background Experiment (DIRBE) all-sky survey with the locations of known galaxies in the IRAS Catalog of Extragalactic Objects and the Center for Astrophysics Catalog of Galaxies led to the detection of as many as 56 galaxies. In this paper, we present the photometric analysis of these detections and an analysis of their dust properties. The sample is dominated by late-type spirals and active galaxies, and their far-IR continuua between 25-240 micron...

  12. COBE DMR results and implications. [Differential Microwave Radiometer

    Science.gov (United States)

    Smoot, George F.

    1992-01-01

    This lecture presents early results obtained from the first six months of measurements of the Cosmic Microwave Background (CMB) by Differential Microwave Radiometers (DMR) aboard COBE and discusses significant cosmological implications. The DMR maps show the dipole anisotropy and some galactic emission but otherwise a spatially smooth early universe. The measurements are sufficiently precise that we must pay careful attention to potential systematic errors. Maps of galactic and local emission such as those produced by the FIRAS and DIRBE instruments will be needed to identify foregrounds from extragalactic emission and thus to interpret the results in terms of events in the early universe. The current DMR results are significant for Cosmology.

  13. The Implications of the COBE-DMR Results for Cosmic Strings

    OpenAIRE

    Bennett, David P.; Stebbins, Albert; Bouchet, Francois R.

    1992-01-01

    We compare the anisotropies in the cosmic microwave background radiation measured by the COBE experiment to the predictions of cosmic strings. We use an analytic model for the $\\Delta T/T$ power spectrum that is based on our previous numerical simulations to show that the COBE results imply a value for the string mass per unit length, $\\mu$ under the assumption that cosmic strings are the source of the measured anisotropy. We find $G\\mu = 1.5\\pm 0.5 \\times 10^{-6}$ which is consistent with th...

  14. COBE-DMR-Normalized Dark Energy Cosmogony

    OpenAIRE

    Mukherjee, Pia; Banday, Anthony J.; Riazuelo, Alain; Górski, Krzysztof M.; Ratra, Bharat

    2003-01-01

    Likelihood analyses of the COBE-DMR sky maps are used to determine the normalization of the inverse-power-law-potential scalar field dark energy model. Predictions of the DMR-normalized model are compared to various observations to constrain the allowed range of model parameters. Although the derived constraints are restrictive, evolving dark energy density scalar field models remain an observationally-viable alternative to the constant cosmological constant model.

  15. The COBE cosmic 3 K anisotropy experiment: A gravity wave and cosmic string probe

    Science.gov (United States)

    Bennett, Charles L.; Smoot, George F.

    1989-01-01

    Among the experiments to be carried into orbit next year, by the COBE satellite, are differential microwave radiometers. They will make sensitive all-sky maps of the temperature of the cosmic microwave background radiation at three frequencies, giving dipole, quadrupole, and higher order multipole measurements of the background radiation. The experiment will either detect, or place significant constraints on, the existence of cosmic strings and long wavelength gravity waves.

  16. Cosmic microwave background probes models of inflation

    Science.gov (United States)

    Davis, Richard L.; Hodges, Hardy M.; Smoot, George F.; Steinhardt, Paul J.; Turner, Michael S.

    1992-01-01

    Inflation creates both scalar (density) and tensor (gravity wave) metric perturbations. We find that the tensor-mode contribution to the cosmic microwave background anisotropy on large-angular scales can only exceed that of the scalar mode in models where the spectrum of perturbations deviates significantly from scale invariance. If the tensor mode dominates at large-angular scales, then the value of DeltaT/T predicted on 1 deg is less than if the scalar mode dominates, and, for cold-dark-matter models, bias factors greater than 1 can be made consistent with Cosmic Background Explorer (COBE) DMR results.

  17. Hot and Cold Spots in the First plus Second Year COBE/DMR Maps

    OpenAIRE

    Cayon, Laura; Smoot, George

    1995-01-01

    Density perturbations at the decoupling epoch produce angular fluctuations in the temperature of the Cosmic Microwave Background (CMB) radiation that may appear as hot and cold spots. Observational data of the CMB includes instrumental noise in addition to the cosmological signal. One would like to determine which of the observed spots are produced by the noise and which correspond to signal. In this work we first present a statistical analysis of the first plus second year COBE/DMR map at 53...

  18. Constraints on the topology of the universe from the 2-yr COBE data

    OpenAIRE

    de Oliveira-Costa, Angelica; Smoot, George F.

    1994-01-01

    The cosmic microwave background (CMB) is a unique probe of cosmological parameters and conditions. There is a connection between anisotropy in the CMB and the topology of the Universe. Adopting a universe with the topology of a 3-Torus, or a universe where only harmonics of the fundamental mode are allowed, and using 2-years of COBE/DMR data, we obtain constraints on the topology of the Universe. Previous work constrained the topology using the slope information and the correlation function o...

  19. Comments on the statistical analysis of excess variance in the COBE differential microwave radiometer maps

    Science.gov (United States)

    Wright, E. L.; Smoot, G. F.; Kogut, A.; Hinshaw, G.; Tenorio, L.; Lineweaver, C.; Bennett, C. L.; Lubin, P. M.

    1994-01-01

    Cosmic anisotrophy produces an excess variance sq sigma(sub sky) in the Delta maps produced by the Differential Microwave Radiometer (DMR) on cosmic background explorer (COBE) that is over and above the instrument noise. After smoothing to an effective resolution of 10 deg, this excess sigma(sub sky)(10 deg), provides an estimate for the amplitude of the primordial density perturbation power spectrum with a cosmic uncertainty of only 12%. We employ detailed Monte Carlo techniques to express the amplitude derived from this statistic in terms of the universal root mean square (rms) quadrupole amplitude, (Q sq/RMS)(exp 0.5). The effects of monopole and dipole subtraction and the non-Gaussian shape of the DMR beam cause the derived (Q sq/RMS)(exp 0.5) to be 5%-10% larger than would be derived using simplified analytic approximations. We also investigate the properties of two other map statistics: the actual quadrupole and the Boughn-Cottingham statistic. Both the sigma(sub sky)(10 deg) statistic and the Boughn-Cottingham statistic are consistent with the (Q sq/RMS)(exp 0.5) = 17 +/- 5 micro K reported by Smoot et al. (1992) and Wright et al. (1992).

  20. Search for unresolved sources in the COBE-DMR two-year sky maps

    Science.gov (United States)

    Kogut, A.; Banday, A. J.; Bennett, C. L.; Hinshaw, G.; Loewenstein, K.; Lubin, P.; Smoot, G. F.; Wright, E. L.

    1994-01-01

    We have searched the temperature maps from the Cosmic Background Explorer (COBE) Differential Microwave Radiometers (DMR) first two years of data for evidence of unresolved sources. The high-latitude sky (absolute value of b greater than 30 deg) contains no sources brighter than 192 microKelvin thermodynamic temperature (322 Jy at 53 GHz). The cumulative count of sources brighter than threshold T, N(greater than T), is consistent with a superposition of instrument noise plus scale-invariant spectrum of cosmic temperature fluctuations normalized to Q(sub rms-PS) = 17 microKelvin. We examine the temperature maps toward nearby clusters and find no evidence for any Sunyaev-Zel'dovich effect, delta y less than 7.3 x 10(exp -6) (95% CL) averaged over the DMR beam. We examine the temperature maps near the brightest expected radio sources and detect no evidence of significant emission. The lack of bright unresolved sources in the DMR maps, taken with anisotropy measurements on smaller angular scales, places a weak constraint on the integral number density of any unresolved Planck-spectrum sources brighter than flux density S, n(greater than S) less than 2 x 10(exp 4)/(S/1 Jy)(exp 2)/sr.

  1. On the Origins of the CMB: Insight from the COBE, WMAP, and Relikt-1 Satellites

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2007-01-01

    Full Text Available The powerful “Cosmic Microwave Background (CMB” signal currently associated with the origins of the Universe is examined from a historical perspective and relative to the experimental context in which it was measured. Results from the COBE satellite are reviewed, with particular emphasis on the systematic error observed in determining the CMB temperature. The nature of the microwave signal emanating from the oceans is also discussed. From this analysis, it is demonstrated that it is improper for the COBE team to model the Earth as a 285 K blackbody source. The assignment of temperatures to objects that fail to meet the requirements set forth in Kirchhoff’s law constitutes a serious overextension of the laws of thermal emission. Using this evidence, and the general rule that powerful signals are associated with proximal sources, the CMB monopole signal is reassigned to the oceans. In turn, through the analysis of COBE, WMAP, and Relikt-1 data, the dipole signal is attributed to motion through a much weaker microwave field present both at the position of the Earth and at the second Lagrange point.

  2. A Study of External Galaxies Detected by COBE-DIRBE

    CERN Document Server

    Odenwald, S; Smoot, G F; Odenwald, Sten; Newmark, Jeffrey; Smoot, George

    1996-01-01

    A comparison of the COBE, Diffuse Infrared Background Experiment (DIRBE) all-sky survey with the locations of known galaxies in the IRAS Catalog of Extragalactic Objects and the Center for Astrophysics Catalog of Galaxies led to the detection of as many as 56 galaxies. In this paper, we present the photometric analysis of these detections and an analysis of their dust properties. The sample is dominated by late-type spirals and active galaxies, and their far-IR continuua between 25-240 microns suggest a single dust component dominating the far-IR emission. We show that for the spirals, T(dust)= 27.6 K, and for the active galaxies, T(dust) = 35.5 K. Estimates of the ratio of the mass of the dust component detected at T(dust) = 20 - 30 K to a hypothetical component with T(dust) = 15 K provide modest constraints to the Very Cold Dust (VCD) component present in the galaxies detected at 140 and 240 microns. VCD components with less than times the mass of the 20-30 K dust are consistent with all of the upper limits...

  3. Exploring Effects of Background Context Familiarity and Signaling on Comprehension, Recall, and Cognitive Load

    Science.gov (United States)

    Song, Minjung; Bruning, Roger

    2016-01-01

    This study was designed to explore the effects of different geographical background contexts and signalling for information about global warming on comprehension, recall and cognitive load. Two different geographical contexts, US and Korean, were employed to frame explanations of global warming phenomena to US students. Two signalling conditions…

  4. Assessment of Models of Galactic Thermal Dust Emission Using COBE/FIRAS and COBE/DIRBE Observations

    CERN Document Server

    Odegard, N; Chuss, D T; Miller, N J

    2016-01-01

    Accurate modeling of the spectrum of thermal dust emission at millimeter wavelengths is important for improving the accuracy of foreground subtraction for CMB measurements, for improving the accuracy with which the contributions of different foreground emission components can be determined, and for improving our understanding of dust composition and dust physics. We fit four models of dust emission to high Galactic latitude COBE/FIRAS and COBE/DIRBE observations from 3 millimeters to 100 microns and compare the quality of the fits. We consider the two-level systems model because it provides a physically motivated explanation for the observed long wavelength flattening of the dust spectrum and the anticorrelation between emissivity index and dust temperature. We consider the model of Finkbeiner, Davis, and Schlegel because it has been widely used for CMB studies, and the generalized version of this model recently applied to Planck data by Meisner and Finkbeiner. For comparison we have also fit a phenomenologic...

  5. WMAP confirming the ellipticity in BOOMERanG and COBE CMB maps

    CERN Document Server

    Gurzadyan, V G; De Bernardis, P; Bianco, C L; Bock, J J; Boscaleri, A; Crill, B P; De Troia, G; Hivon, E; Hristov, V V; Kashin, A L; Kuloghlian, H; Lange, A E; Masi, S; Mauskopf, P D; Montroy, T; Natoli, P; Netterfield, C B; Pascale, E; Piacentini, F; Polenta, G; Ruhl, J; Yegorian, G

    2003-01-01

    The recent study of BOOMERanG 150 GHz Cosmic Microwave Background (CMB) radiation maps have detected ellipticity of the temperature anisotropy spots independent on the temperature threshold. The effect has been found for spots up to several degrees in size, where the biases of the ellipticity estimator and of the noise are small. To check the effect, now we have studied, with the same algorithm and in the same sky region, the WMAP maps. We find ellipticity of the same average value also in WMAP maps, despite of the different sensitivity of the two experiments to low multipoles. Large spot elongations had been detected also for the COBE-DMR maps. If this effect is due to geodesic mixing and hence due to non precisely zero curvature of the hypebolic Universe, it can be linked to the origin of WMAP low multipoles anomaly.

  6. Exploring the Relationship Between Working Memory, Compressor Speed, and Background Noise Characteristics

    DEFF Research Database (Denmark)

    Ohlenforst, Barbara; Souza, Pamela E.; MacDonald, Ewen

    2016-01-01

    Objectives: Previous work has shown that individuals with lower working memory demonstrate reduced intelligibility for speech processed with fast-acting compression amplification. This relationship has been noted in fluctuating noise, but the extent of noise modulation that must be present to...... elicit such an effect is unknown. This study expanded on previous study by exploring the effect of background noise modulations in relation to compression speed and working memory ability, using a range of signal to noise ratios. Design: Twenty-six older participants between ages 61 and 90 years were...... grouped by high or low working memory according to their performance on a reading span test. Speech intelligibility was measured for low-context sentences presented in background noise, where the noise varied in the extent of amplitude modulation. Simulated fast- or slowacting compression amplification...

  7. COBE DMR-normalized open inflation cold dark matter cosmogony

    Science.gov (United States)

    Gorski, Krzysztof M.; Ratra, Bharat; Sugiyama, Naoshi; Banday, Anthony J.

    1995-01-01

    A cut-sky orthogonal mode analysis of the 2 year COBE DMR 53 and 90 GHz sky maps (in Galactic coordinates) is used to determine the normalization of an open inflation model based on the cold dark matter (CDM) scenario. The normalized model is compared to measures of large-scale structure in the universe. Although the DMR data alone does not provide sufficient discriminative power to prefer a particular value of the mass density parameter, the open model appears to be reasonably consistent with observations when Omega(sub 0) is approximately 0.3-0.4 and merits further study.

  8. The effect of Community Based Education and Service (COBES) on medical graduates’ choice of specialty and willingness to work in rural communities in Ghana

    OpenAIRE

    Amalba, Anthony; van Mook, Walther Nicolaas Karel Anton; Mogre, Victor; Scherpbier, Albert Jakob Johannus Antonius

    2016-01-01

    Background Career choices and placements of healthcare professionals in rural areas are a major problem worldwide, and their recruitment and retention to these areas have become a challenge to the health sector. The purpose of this study was to investigate the effect of Community Based Education and Service (COBES) on medical graduates' choice of specialty and willingness to work in a rural area. Method This cross sectional survey was conducted among 56 pioneering graduates that followed a Pr...

  9. The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations

    Science.gov (United States)

    Kogut, Alan J.; Fixsen, D. J.; Chuss, D. T.; Dotson, J.; Dwek, E.; Halpern, M.; Hinshaw, G. F.; Meyer, S. M.; Moseley, S. H.; Seiffert, M. D.; Spergel, D. N.; Wollack, E. J.

    2011-01-01

    The Primordial Inflation Explorer (PIXIE) is a concept for an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. The instrument consists of a polarizing Michelson interferometer configured as a nulling polarimeter to measure the difference spectrum between orthogonal linear polarizations from two co-aligned beams. Either input can view the sky or a temperature-controlled absolute reference blackbody calibrator. Rhe proposed instrument can map the absolute intensity and linear polarization (Stokes I, Q, and U parameters) over the full sky in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). Multi-moded optics provide background-limited sensitivity using only 4 detectors, while the highly symmetric design and multiple signal modulations provide robust rejection of potential systematic errors. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10..3 at 5 standard deviations. The rich PIXIE data set can also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy.

  10. The Primordial Inflation Explorer (PIXIE): a nulling polarimeter for cosmic microwave background observations

    International Nuclear Information System (INIS)

    The Primordial Inflation Explorer (PIXIE) is a concept for an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. The instrument consists of a polarizing Michelson interferometer configured as a nulling polarimeter to measure the difference spectrum between orthogonal linear polarizations from two co-aligned beams. Either input can view the sky or a temperature-controlled absolute reference blackbody calibrator. Rhe proposed instrument can map the absolute intensity and linear polarization (Stokes I, Q, and U parameters) over the full sky in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 μm wavelength). Multi-moded optics provide background-limited sensitivity using only 4 detectors, while the highly symmetric design and multiple signal modulations provide robust rejection of potential systematic errors. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r −3 at 5 standard deviations. The rich PIXIE data set can also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy

  11. A case study exploring science competence and science confidence of middle school girls from marginalized backgrounds

    Science.gov (United States)

    Garcia, Yeni Violeta

    The inclusion of learners from underrepresented background in biology field research experiences has not been widely explored in the literature. Increased access and equity to experiences for groups historically underrepresented in science, technology, engineering, and mathematics (STEM) has been identified as a priority for many, yet little is known about the components these experiences should have and what types of transformations participants undergo as a result of these experiences. This dissertation explored the systemic creation of an intervention purposely designed to serve middle school girls from underrepresented backgrounds, the implementation of such intervention, and effect on the girls' science competence and science confidence. El Espejo, Spanish for "The Mirror," was an ongoing field ecology research program for middle schools girls founded in 2009 at a local interdisciplinary learning center. Girls from all walks of life had the opportunity to be apprentice researchers and to work with scientists and science educators from the local community. All activities were strategically designed to promote student-led inquiry, career awareness, cultural awareness, and opportunities for research and mentorship for girls from underrepresented backgrounds. An increased understanding of if, how, and why this experience was perceived by the girls to be life changing was of importance to add to the conversations that seek ways to inspire and prepare this generation of students to be the next generation of scientists. The study built on systems theory, and on theories that were embedded in the participants' system: critical race theory, identity theory, and experiential learning theory, grounded in the context of the lived experiences of girls from underrepresented backgrounds. The girls' experiences were captured through journals, observer participant notes, photo-documentation, artifacts (posters, videos) created by the girls, and by using science perception

  12. COBE-DMR-normalisation for inflationary flat dark matter models

    CERN Document Server

    Stompor, R; Banday, A J

    1995-01-01

    The two-year COBE-DMR 53 and 90 GHz sky maps, in both galactic and ecliptic coordinates, are used to determine the normalisation of inflationary universe models with a flat global geometry and adiabatic density perturbations. The appropriately normalised cold and mixed dark matter models and cosmological constant dominated, cold dark matter models, computed for a range of values of Omega_b and h, are then compared to various measures of structure in the universe. Critical density CDM models appear to be irreconcilable with observations on both large and small scales simultaneously, whereas MDM models provide a somewhat better fit to the data. Although the COBE-DMR data alone prefer a nearly critical value for the total density, low-density cosmological constant models with Omega_0 greater than or equal to 0.15 can not be rejected at a confidence level exceeding 95%. Such models may also provide a significantly better fit to the matter distribution data than critical density CDM.

  13. The Relativistic Effect of the Deviation between the CMB Temperatures Obtained by the COBE Satellite

    Directory of Open Access Journals (Sweden)

    Rabounski D.

    2007-01-01

    Full Text Available The Far-Infrared Absolute Spectrophotometer (FIRAS on the COBE satellite, gives different temperatures of the Cosmic Microwave Background. This deviation has a theoretical explanation in the Doppler effect on the dipole (weak component of the radiation, the true microwave background of the Universe that moves at 365 km/sec, if the monopole (strong component of the radiation is due to the Earth. Owing to the Doppler effect, the dipole radiation temperature (determined by the 1st derivative of the monopole is lower than the monopole radiation temperature, with a value equal to the observed deviation. By this theory, the WMAP and PLANCK satellites, targeting the L2 point in the Sun-Earth-Moon system, should be insensitive to the monopole radiation. In contrast to the launched WMAP satellite, the PLANCK satellite will have on board absolute instruments which will not be able to detect the measured temperature of the Cosmic Microwave Background. That the monopole (strong component of the observed Cosmic Microwave Background is generated by the Earth is given a complete theoretical proof herein.

  14. Inflation and large-scale structure formation after the Cosmic Background Explorer

    International Nuclear Information System (INIS)

    The simplest realizations of the new inflationary scenario typically give rise to primordial density fluctuations which deviate logarithmically from the scale-free Harrison-Zeldovich spectrum. We consider a number of such examples and in each case we normalize the amplitude of the fluctuations with the recent Cosmic Background Explorer measurement of the microwave background anisotropy. The predictions for the bulk velocities as well as anisotropies on smaller (1 to 2 deg) angular scales are compared with the Harrison-Zeldovich case. Deviations from the latter range from a few to about 15%. We also estimate the redshift beyond which the quasars would not be expected to be seen. The inflationary quasar cutoff redshifts can vary by as much as 25% from the Harrison-Zeldovich case. We find that the inflationary scenario provides a good starting point for a theory of large-scale structure in the universe provided the dark matter is a combination of cold plus (10--30%) hot components

  15. Generalised inflation with a gravitational wave background

    OpenAIRE

    Lukash, V. N.; Mikheeva, E. V.; Muller, V.; Malinovsky, A. M.

    2000-01-01

    We propose a Lambda-inflation model which explains a significant part of the COBE signal by primordial cosmic gravitational waves. The primordial density perturbations fulfill both the constraints of large-scale microwave background and galaxy cluster normalization. The model is tested against the galaxy cluster power spectrum and the high-multipole angular CMB anisotropy.

  16. Reconstructing the inflaton potential for an almost flat cobe spectrum

    CERN Document Server

    Mielke, E W; Mielke, Eckehard W; Schunck, Franz E

    1995-01-01

    Using the Hubble parameter as new `inverse time' coordinate (H-formalism), a new method of reconstructing the inflaton potential is developed also using older results which, in principle, is applicable to any order of the slow-roll approximation. In first and second order, we need three observational data as inputs: the scalar spectral index n_s and the amplitudes of the scalar and the tensor spectrum. We find constraints between the values of n_s and the corresponding values for the wavelength \\lambda . By imposing a dependence \\lambda (n_s), we were able to reconstruct and visualize inflationary potentials which are compatible with recent COBE and other astrophysical observations. >From the reconstructed potentials, it becomes clear that one cannot find only one special value of the scalar spectral index n_s.

  17. Report on 3- and 4-Point Correlation Statistics in COBE DMR Anisotropy Maps

    Science.gov (United States)

    Hinshaw, Gary; Gorski, Krzystof M.; Bennett, Charles L.; Banday, Anthony J.

    1996-01-01

    As part of the work performed under this contract, we have computed the 3- and 4-point correlation functions of the COBE-DMR 2-year and 4-year anisotropy maps. The results of our work showed that the 3-point correlation function is consistent with zero and that the 4-point function is not a very sensitive probe of non-Gaussian behavior in the COBE-DMR data.

  18. Hot and cold spots in the first plus second year COBE/DMR maps

    CERN Document Server

    Cayon, L; Cayon, Laura; Smoot, George

    1995-01-01

    Density perturbations at the decoupling epoch produce angular fluctuations in the temperature of the Cosmic Microwave Background (CMB) radiation that may appear as hot and cold spots. Observational data of the CMB includes instrumental noise in addition to the cosmological signal. One would like to determine which of the observed spots are produced by the noise and which correspond to signal. In this work we first present a statistical analysis of the first plus second year COBE/DMR map at 53 GHz that reveals the presence of cosmological signal in the data. The analysis is based on Harrison-Zeldovich Monte Carlo realizations and utilizes a generalized \\chi^2 statistic. The method is applied to the number of spots and the fraction of the total area that appear above/below a certain value of the dispersion of the noise, including and excluding the quadrupole, giving Q_{rms-PS}=15^{+3}_{-6}, 18^{+5}_{-7} \\mu K and Q_{rms-PS}=18^{+3}_{-4}, 21\\pm6 \\mu K, at the 95\\% confidence level, respectively. The data taken b...

  19. Constraints on the topology of the universe from the 2-year COBE data

    CERN Document Server

    Smoot, G F

    1994-01-01

    The cosmic microwave background (CMB) is a unique probe of cosmological parameters and conditions. There is a connection between anisotropy in the CMB and the topology of the Universe. Adopting a universe with the topology of a 3-Torus, or a universe where only harmonics of the fundamental mode are allowed, and using 2-years of COBE/DMR data, we obtain constraints on the topology of the Universe. Previous work constrained the topology using the quadrupole component and the correlation function of the CMB. In this letter, we obtain more accurate results by using all multipole moments, avoiding approximations by computing their full covariance matrix. We obtain the best fit for a cubic toroidal universe of scale 7200h^{-1}Mpc for n=1. The data set a lower limit on the cell size of 4320h^{-1}Mpc at 95\\% confidence and 5880h^{-1}Mpc at 68\\% confidence. These results show that the most probable cell size would be around 1.2 times larger than the horizon scale, implying that the 3-Torus topology is no longer an int...

  20. Reappraising foreground contamination in the COBE-DMR data

    CERN Document Server

    Banday, A J; Davies, R D; Davis, R J; Górski, K M

    2003-01-01

    With the advent of all-sky H-Alpha surveys it is possible to determine a reliable free-free template of the diffuse interstellar medium (Dickinson, Davies & Davis 2003) which can be used in conjunction with the synchrotron and dust templates to correct CMB observations for diffuse Galactic foregrounds. We have used the COBE-DMR data at 31.5, 53 and 90 GHz and employed cross- correlation techniques to re-evaluate the foreground contributions, particularly that due to dust which is known to be correlated with H-Alpha (and free-free) emission. The DMR microwave maps are found to contain, as well as the expected synchrotron and free-free components, a component tightly correlated to the 140 micron dust maps of DIRBE. At 31.5, 53 and 90 GHz this emission is 6.3 +/- 0.6, 2.4 +/- 0.4 and 2.2 +/- 0.4 microK/(MJy/sr) at 140 microns respectively. When corrected for the contribution from thermal dust following model 7 of Finkbeiner, Davis & Schlegel (1999), a strong anomalous dust emission component remains, whi...

  1. Exploring the Effect of Background Knowledge and Text Cohesion on Learning from Texts in Computer Science

    Science.gov (United States)

    Gasparinatou, Alexandra; Grigoriadou, Maria

    2013-01-01

    In this study, we examine the effect of background knowledge and local cohesion on learning from texts. The study is based on construction-integration model. Participants were 176 undergraduate students who read a Computer Science text. Half of the participants read a text of maximum local cohesion and the other a text of minimum local cohesion.…

  2. Exploring Patterns of Achievement and Intellectual Development among Academically Successful Women from Disadvantaged Backgrounds.

    Science.gov (United States)

    LePage-Lees, Pamela

    1997-01-01

    Explored the educational experiences of 21 academically successful women who were disadvantaged as children. Results indicate that resilient women who had endured stress as children often developed a highly advanced level of "emotional intelligence" or "interpersonal and intrapersonal intelligence." Presents educational strategies for encouraging…

  3. Another look at distortions of the Cosmic Microwave Background spectrum

    Science.gov (United States)

    De Zotti, G.; Negrello, M.; Castex, G.; Lapi, A.; Bonato, M.

    2016-03-01

    We review aspects of Cosmic Microwave Background (CMB) spectral distortions which do not appear to have been fully explored in the literature. In particular, implications of recent evidences of heating of the intergalactic medium (IGM) by feedback from active galactic nuclei are investigated. Taking also into account the IGM heating associated to structure formation, we argue that values of the y parameter of several × 10-6, i.e. a factor of a few below the COBE/FIRAS upper limit, are to be expected. The Compton scattering by the re-ionized plasma also re-processes primordial distortions, adding a y-type contribution. Hence no pure Bose-Einstein-like distortions are to be expected. An assessment of Galactic and extragalactic foregrounds, taking into account the latest results from the Planck satellite as well as the contributions from the strong CII and CO lines from star-forming galaxies, demonstrates that a foreground subtraction accurate enough to fully exploit the PIXIE sensitivity will be extremely challenging. Motivated by this fact we also discuss methods to detect spectral distortions not requiring absolute measurements and show that accurate determinations of the frequency spectrum of the CMB dipole amplitude may substantially improve over COBE/FIRAS limits on distortion parameters. Such improvements may be at reach of next generation CMB anisotropy experiments. The estimated amplitude of the Cosmic Infrared Background (CIB) dipole might be detectable by careful analyses of Planck maps at the highest frequencies. Thus Planck might provide interesting constraints on the CIB intensity, currently known with a simeq 30% uncertainty.

  4. Measured ground performance and predicted orbital performance of the superfluid helium dewar for the Cosmic Background Explorer

    Science.gov (United States)

    Hopkins, Richard A.; Ryschkewitsch, M. G.

    1986-01-01

    A critical component of the Cosmic Background Explorer observatory, which is to be lifted to orbit in 1988, is the 650-l superfluid He dewar housing a far-IR absolute spectrophotometer and a diffuse IR background experiment. Attention is presently given to the results of a four-month-long test program encompassing dewar filling verification, vibration characteristics, thermal performance over orbital lifetime, and aperture cover ejection behavior. No significant flaws have been noted; the orbital cryogen lifetime is projected to be 14 months.

  5. LoCuSS: Exploring the selection of faint blue background galaxies for cluster weak-lensing

    CERN Document Server

    Ziparo, Felicia; Okabe, Nobuhiro; Haines, Chris P; Pereira, Maria J; Egami, Eiichi

    2015-01-01

    Cosmological constraints from galaxy clusters rely on accurate measurements of the mass and internal structure of clusters. An important source of systematic uncertainty in cluster mass and structure measurements is the secure selection of background galaxies that are gravitationally lensed by clusters. This issue has been shown to be particular severe for faint blue galaxies. We therefore explore the selection of faint blue background galaxies, by reference to photometric redshift catalogs derived from the COSMOS survey and our own observations of massive galaxy clusters at z~0.2. We show that methods relying on photometric redshifts of galaxies in/behind clusters based on observations through five filters, and on deep 30-band COSMOS photometric redshifts are both inadequate to identify safely faint blue background galaxies. This is due to the small number of filters used by the former, and absence of massive galaxy clusters at redshifts of interest in the latter. We therefore develop a pragmatic method to c...

  6. Exploration of Gamburtsev Subglacial Mountains, East Antarctica: Background and Plans for the Near Future

    Science.gov (United States)

    Talalay, Pavel; Sun, Youhong; Zhao, Yue; Li, Yuansheng; Cao, Pinlu; Xu, Huiwen; Zheng, Zhichuan; Wang, Rusheng; Zhang, Nan; Markov, Alexey; Yu, Dahui; Fan, Xiaopeng; Hu, Zhengyi; Yang, Cheng; Gong, Da; Hong, Jialing; Liu, Chunpeng; Han, Junjie; Yu, Chengfeng; Wang, Lili

    2014-05-01

    The Gamburtsev Subglacial Mountains (GSM), located in the central part of East Antarctica, were discovered by the Soviet team of the 3rd Complex Antarctic Expedition in 1958-1959. The GSM has highly dissected Alpine topography reaching maximum elevations of 3000 m and are completely covered by over 600 m of ice and snow. The mechanism driving uplift of the young-shaped GSM in the middle of the old East Antarctic Shield is unknown. With only limited constraints available on the topography, geology, and lithospheric structure, the origin of the GSM has been a matter of considerable speculation. The latest interpretation suggested that the GSM were formed during Permian and Cretaceous (roughly 250-100 Ma ago) due to the combination of rift-flank uplift, root buoyancy and the isostatic response. Later on, the Antarctic Ice Sheet covered the range and protected it from erosion. However, this theory cannot explain lack of erosion process during many millions years in between uplifting and beginning of glaciation. The next step of the GSM exploration focuses on the direct observation of ice sheet bed by drilling. In order to penetrate into subglacial bedrock in the GSM region the development activity already has been started in China. Drilling operations in Antarctica are complicated by extremely low temperature at the surface and within ice sheet, by ice flow, the absence of roads and infrastructures, storms, winds, snowfalls, etc. All that are the reasons that up to the present moment bedrock cores were never obtained at inland of Antarctica. It is proposed to use cable-suspended drilling technology in which an armored cable with a winch is used instead of a pipe-string to provide power to the down-hole motor system and to retrieve the down-hole unit. It is assumed to choose the drill site with the ice thickness at most of 1000 m and to pierce into the mountain slope to a depth of few meters. Proposed borehole construction includes five following steps: (1) dry core

  7. Exploring background variability of a low-level (quartz) gas proportional counter using pulse shape and distribution analysis

    International Nuclear Information System (INIS)

    The NIST low-level beta counting system is designed to capture digitally and timestamp each event for retrospective analysis. As a result, low and stable backgrounds are achieved and lead to extremely low detection and quantification limits for measuring, e.g., 14C of atmospheric gases and aerosol. The objective here is to explore the variability of the background count rate (counts per day) of several small (1 mL) freshly-assembled gas proportional counters (GPCs). The mean is 14.0 day-1 with 95 % confidence limits 11.2-16.8 day-1. The raw count per day data was non-normal and so a Log transformation was applied to achieve normality and to rigorously compute normal tolerance limits. Back in the original space such (95 % confidence, 95 % coverage) tolerance limits were 2.5-47.8 day-1. These limits are taken as acceptance criteria for any GPCs assembled in the future. (author)

  8. Primordial Inflation Polarization Explorer (Phase 2)

    Science.gov (United States)

    Kogurt, Alan; Bennett, Charles

    This is the Lead Proposal for the proposed investigation "Primordial Inflation Polarization Explorer (Phase 2)" We propose to fly the Primordial Inflation Polarization Explorer (PIPER) to measure the polarization of the cosmic microwave background (CMB) and search for the imprint of gravitational waves produced during an inflationary epoch in the early universe. Such a signal is expected to exist: the simplest inflation models predict tensor-to-scalar ratio 0.01 optimized to detect the inflationary signal on large angular scales. It consists of two co-aligned telescopes cooled to 1.5 K within a large liquid helium bucket dewar. A variable-delay polarization modulator (VPM) on each telescope chops between linear and circular polarization to isolate the polarized signal while rejecting the much brighter unpolarized emission. PIPER's innovative architecture combines cryogenic optics with kilo-pixel detector arrays to provide unprecedented sensitivity to CMB polarization. The fast modulation between linear and circular polarization takes advantage of the lack of astrophysical circular polarization to eliminate common sources of systematic error. The sensitivity and control of systematic errors in turn enable measurements over most of the sky from mid-latitude launch sites; long-duration Antarctic flights are not required. With sensitivity r proposed work, including detector development, polarization modulation, instrument integration, and cryogenic ballooning. The team includes the Instrument Integration Lead and Instrument Test Lead for the Wilkinson Microwave Anisotropy Probe (WMAP) as well as the lead authors for the systematic error papers for the ground-breaking COBE-DMR, COBE-FIRAS, and WMAP instruments. The team has demonstrated expertise in data analysis including pipeline development, foreground modeling, and cosmological parameter fitting. PIPER began development in 2009 and is nearing completion. With first flight scheduled soon, the development schedule

  9. Introducing 3D U-statistic method for separating anomaly from background in exploration geochemical data with associated software development

    Indian Academy of Sciences (India)

    Seyyed Saeed Ghannadpour; Ardeshir Hezarkhani

    2016-03-01

    The U-statistic method is one of the most important structural methods to separate the anomaly from the background. It considers the location of samples and carries out the statistical analysis of the data without judging from a geochemical point of view and tries to separate subpopulations and determine anomalous areas. In the present study, to use U-statistic method in three-dimensional (3D) condition, U-statistic is applied on the grade of two ideal test examples, by considering sample Z values (elevation). So far, this is the first time that this method has been applied on a 3D condition. To evaluate the performance of 3D U-statistic method and in order to compare U-statistic with one non-structural method, the method of threshold assessment based on median and standard deviation (MSD method) is applied on the twoexample tests. Results show that the samples indicated by U-statistic method as anomalous are more regular and involve less dispersion than those indicated by the MSD method. So that, according to the location of anomalous samples, denser areas of them can be determined as promising zones. Moreover,results show that at a threshold of U = 0, the total error of misclassification for U-statistic method is much smaller than the total error of criteria of $\\bar{x} + n \\times s$. Finally, 3D model of two test examples for separating anomaly from background using 3D U-statistic method is provided. The source code for a software program, which was developed in the MATLAB programming language in order to perform the calculations of the 3D U-spatial statistic method, is additionally provided. This software is compatible with all the geochemical varieties and can be used in similar exploration projects.

  10. Introducing 3D U-statistic method for separating anomaly from background in exploration geochemical data with associated software development

    Science.gov (United States)

    Ghannadpour, Seyyed Saeed; Hezarkhani, Ardeshir

    2016-03-01

    The U-statistic method is one of the most important structural methods to separate the anomaly from the background. It considers the location of samples and carries out the statistical analysis of the data without judging from a geochemical point of view and tries to separate subpopulations and determine anomalous areas. In the present study, to use U-statistic method in three-dimensional (3D) condition, U-statistic is applied on the grade of two ideal test examples, by considering sample Z values (elevation). So far, this is the first time that this method has been applied on a 3D condition. To evaluate the performance of 3D U-statistic method and in order to compare U-statistic with one non-structural method, the method of threshold assessment based on median and standard deviation (MSD method) is applied on the two example tests. Results show that the samples indicated by U-statistic method as anomalous are more regular and involve less dispersion than those indicated by the MSD method. So that, according to the location of anomalous samples, denser areas of them can be determined as promising zones. Moreover, results show that at a threshold of U = 0, the total error of misclassification for U-statistic method is much smaller than the total error of criteria of bar {x}+n× s. Finally, 3D model of two test examples for separating anomaly from background using 3D U-statistic method is provided. The source code for a software program, which was developed in the MATLAB programming language in order to perform the calculations of the 3D U-spatial statistic method, is additionally provided. This software is compatible with all the geochemical varieties and can be used in similar exploration projects.

  11. A New Blackbody Radiation Law Based on Fractional Calculus and its Application to NASA COBE Data

    OpenAIRE

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-01-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA COBE data by means of a non-extensive formula with a parameter $(q-1)$, a formula proposed by Ertik et al. with a fractional parameter $(\\alpha-1)$, and our new formula including a parameter $(p-1)$, as well as the Bose-Einstein distribution with a dimensionless chemical potential $\\mu$. It can be said that on...

  12. Do wavelets really detect non-Gaussianity in the 4-year COBE data?

    CERN Document Server

    Mukherjee, P; Lasenby, A N

    2001-01-01

    We investigate the detection of non-Gaussianity in the 4-year COBE data reported by Pando, Valls-Gabaud & Fang (1998), using a technique based on the discrete wavelet transform. Their analysis was performed on the two DMR faces centred on the North and South Galatic poles respectively, using the Daubechies 4 wavelet basis. We are unable to reproduce the numerical results of Pando et al., but note that the results we present here have been independently verified (Valls-Gabaud, private communication). By calculating unbiassed estimates of the skewness, kurtosis and scale-scale correlation of the wavelet coefficients in all of the available scale domains of the transform, we obtain several detections of non-Gaussianity in the DMR-DSMB map at greater than the 99 per cent confidence level, but these occur mainly on pixel-pixel scales and are therefore not cosmological in origin. Indeed, after removing all multipoles beyond l = 40 from the COBE maps, these detections disappear. We repeat the analysis for the 53...

  13. Report on 3 and 4-point correlation statistics in the COBE DMR anisotrophy maps

    Science.gov (United States)

    Hinshaw, Gary (Principal Investigator); Gorski, Krzystof M.; Banday, Anthony J.; Bennett, Charles L.

    1996-01-01

    As part of the work performed under NASA contract # NAS5-32648, we have computed the 3-point and 4-point correlation functions of the COBE-DNIR 2-year and 4-year anisotropy maps. The motivation for this study was to search for evidence of non-Gaussian statistical fluctuations in the temperature maps: skewness or asymmetry in the case of the 3-point function, kurtosis in the case of the 4-point function. Such behavior would have very significant implications for our understanding of the processes of galaxy formation, because our current models of galaxy formation predict that non-Gaussian features should not be present in the DMR maps. The results of our work showed that the 3-point correlation function is consistent with zero and that the 4-point function is not a very sensitive probe of non-Gaussian behavior in the COBE-DMR data. Our computation and analysis of 3-point correlations in the 2-year DMR maps was published in the Astrophysical Journal Letters, volume 446, page L67, 1995. Our computation and analysis of 3-point correlations in the 4-year DMR maps will be published, together with some additional tests, in the June 10, 1996 issue of the Astrophysical Journal Letters. Copies of both of these papers are attached as an appendix to this report.

  14. Ponderable soliton stars and cosmic background radiation

    Science.gov (United States)

    Chiu, Hong-Yee

    1990-01-01

    A theory is developed to describe the possible perturbations of the cosmic background radiation (CBR) by radiation from ponderable soliton stars in the early universe. Since the temperature of such stars is in the range of 10 to the 6th K, thermalization of their emitted radiation is possible. Two models are considered: one in which thermalization is ignored and one in which decoupling from thermalization is considered as a sudden process. The expected perturbation of the CBR is probably less than 1 percent and is largely around the short-wavelength end, in the form of point radio sources. This result is consistent with the most recent COBE measurements.

  15. Surface Geophysical Exploration Of SX Tank Farm At The Hanford Site Results Of Background Characterization With Magnetics And Electromagnetics

    International Nuclear Information System (INIS)

    This report presents the results of the background characterization of the cribs and trenches surrounding the SX tank farm prepared by HydroGEOPHYSICS Inc, Columbia Energy and Environmental Services Inc and Washington River Protection Solutions.

  16. SURFACE GEOPHYSICAL EXPLORATION OF SX TANK FARM AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH MAGNETICS AND ELECTROMAGNETICS

    Energy Technology Data Exchange (ETDEWEB)

    MYERS DA; RUCKER D; LEVIT M; CUBBAGE B; HENDERSON C

    2009-09-24

    This report presents the results of the background characterization of the cribs and trenches surrounding the SX tank farm prepared by HydroGEOPHYSICS Inc, Columbia Energy & Environmental Services Inc and Washington River Protection Solutions.

  17. Exploration

    Science.gov (United States)

    Wilburn, D.R.; Porter, K.E.

    1999-01-01

    This summary of international nonfuel mineral exploration activities for 1998 draws on available data from literature, industry and US Geological Survey (USGS) specialists. Data on exploration budgets by region and commodity are reported, significant mineral discoveries and exploration target areas are identified and government programs affecting the mineral exploration industry are discussed. Inferences and observations on mineral industry direction are drawn from these data and discussions.

  18. A new blackbody radiation law based on fractional calculus and its application to NASA COBE data

    Science.gov (United States)

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-12-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA COBE data by means of a non-extensive formula with a parameter (q - 1) , a formula proposed by Ertik et al. with a fractional parameter (α - 1) , and our new formula including a parameter (p - 1) , as well as the Bose-Einstein distribution with a dimensionless chemical potential μ. It can be said that one role of the fractional parameter (p - 1) is almost the same as that of chemical potential (μ) as well as that of the parameter (q - 1) in the non-extensive approach.

  19. SURFACE GEOPHYSICAL EXPLORATION OF B & BX & BY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH MAGNETICS AND ELECTROMAGNETICS

    Energy Technology Data Exchange (ETDEWEB)

    MYERS DA

    2007-09-28

    This report documents the results of preliminary surface geophysical exploration activities performed between October and December 2006 at the B, BX, and BY tank farms (B Complex). The B Complex is located in the 200 East Area of the U. S. Department of Energy's Hanford Site in Washington State. The objective of the preliminary investigation was to collect background characterization information with magnetic gradiometry and electromagnetic induction to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity survey. Results of the background characterization show there are several areas located around the site with large metallic subsurface debris or metallic infrastructure.

  20. Preliminary Exploration of the Effect of Background Color on the Speed and Accuracy of Search for an Aided Symbol Target by Typically Developing Preschoolers

    OpenAIRE

    Wilkinson, Krista M.; Coombs, Bridgett

    2010-01-01

    Aided augmentative and alternative communication can be used successfully with individuals with communication disabilities. Recent studies suggest that where possible, arranging symbols based on internal color (placing red fruits together) facilitates search for a target symbol by children with and without Down Syndrome (Wilkinson, Carlin, & Thistle, 2008). We explored whether color cuing of symbol background might offer similar benefits for symbols that cannot be readily arranged by internal...

  1. Can the lack of symmetry in the COBE/DMR maps constrain the topology of the universe?

    CERN Document Server

    De Oliveira-Costa, A; Starobinsky, A A; de Oliveira-Costa, Angelica; Smoot, George F; Starobinsky, Alexei A

    1995-01-01

    Although the cubic T^3 ``small universe" has been ruled out by COBE/DMR results as an interesting cosmological model, we still have the possibility of living in a universe with a more anisotropic topology such as a rectangular T^3 ``small universe" with one or two of its dimensions significantly smaller than the present horizon (which we refer to as T^1- and T^2-models, respectively). In order to rule out these anisotropic topologies as well, we apply a new data analysis method that searches for the specific kind of symmetries that these models should produce. We find that the 2 year COBE/DMR data set a lower limit on the smallest cell size for T^1- and T^2-models of 3000 h^{-1} Mpc, at 95% confidence, for a scale invariant power spectrum (n=1). These results imply that {\\it all} toroidal universes (cubes and rectangles) are ruled out as interesting cosmological models.

  2. Crystallization and preliminary structure analysis of CobE, an essential protein of cobalamin (vitamin B{sub 12}) biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Vévodová, Jitka [Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW (United Kingdom); Graham, Ross M.; Raux, Evelyne; Warren, Martin J. [School of Biological Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Wilson, Keith S., E-mail: keith@ysbl.york.ac.uk [Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW (United Kingdom)

    2005-04-01

    P. aeruginosa CobE, a protein implicated in vitamin B{sub 12} biosynthesis, has been crystallized and data on the native and SeMet forms recorded to resolutions of 1.9 and 1.7 Å, respectively. The anomalous measurements will be used for phasing. CobE, a protein implicated in vitamin B{sub 12} biosynthesis, from Pseudomonas aeruginosa has been overexpressed in Escherichia coli, purified and crystallized using hanging-drop vapour diffusion. The crystals belong to the primitive orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 31.86, b = 41.07, c = 87.41 Å. The diffraction extends to a resolution of 1.9 Å. There is one molecule per asymmetric unit and the estimated solvent content is 35%. SeMet-labelled CobE has been prepared and crystallizes under the same conditions as the native protein with diffraction to 1.7 Å. The anomalous measurements will be used for phasing.

  3. Crystallization and preliminary structure analysis of CobE, an essential protein of cobalamin (vitamin B12) biosynthesis

    International Nuclear Information System (INIS)

    P. aeruginosa CobE, a protein implicated in vitamin B12 biosynthesis, has been crystallized and data on the native and SeMet forms recorded to resolutions of 1.9 and 1.7 Å, respectively. The anomalous measurements will be used for phasing. CobE, a protein implicated in vitamin B12 biosynthesis, from Pseudomonas aeruginosa has been overexpressed in Escherichia coli, purified and crystallized using hanging-drop vapour diffusion. The crystals belong to the primitive orthorhombic space group P212121, with unit-cell parameters a = 31.86, b = 41.07, c = 87.41 Å. The diffraction extends to a resolution of 1.9 Å. There is one molecule per asymmetric unit and the estimated solvent content is 35%. SeMet-labelled CobE has been prepared and crystallizes under the same conditions as the native protein with diffraction to 1.7 Å. The anomalous measurements will be used for phasing

  4. On the origin of the cosmic microwave background anisotropies

    OpenAIRE

    Follop, Ria; Rassat, Anais; Cooray, Asantha; Abdalla, Filipe B.

    2007-01-01

    Suggestions have been made that the microwave background observed by COBE and WMAP and dubbed Cosmic Microwave Background (CMB) may have an origin within our own Galaxy or Earth. To consider the signal that may be correlated with Earth, a correlate-by-eye exercise was attempted by overlaying the CMB map from Wilkinson Microwave Anisotropy Probe on a topographical map of Earth. Remarkably, several hot spots in the CMB map are found to be well aligned with either large cities on Earth or region...

  5. Exploration

    International Nuclear Information System (INIS)

    Oil and gas exploration is a unique kind of business. Businesses providing a vast and ever-changing panoply of products to markets are a focus of several disciplines' energetic study and analysis. The product inventory problem is robust, pertinent, and meaningful, and it merits the voluminous and protracted attention received from keen business practitioners. Prototypical business practitioners, be they trained by years of business hurly-burly, or sophisticated MBAs with arrays of mathematical algorithms and computers, are not normally prepared, however, to recognize the unique nature of exploration's inventories. Put together such a business practitioner with an explorationist and misunderstandings, hidden and open, are inevitable and predictably rife. The first purpose of this paper is to articulate the inherited inventory handling paradigms of business practitioners in relation to exploration's inventories. To do so, standard pedagogy in business administration is used and a case study of an exploration venture is presented. A second purpose is to show the burdens that the misunderstandings create. The result is not just business plans that go awry, but public policies that have effects opposite from those intended

  6. SURFACE GEOPHYSICAL EXPLORATION OF TX AND TY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH MAGNETICS AND ELECTROMAGNETICS

    International Nuclear Information System (INIS)

    This report documents the results of preliminary surface geophysical exploration activities performed between September and October 2007 at the waste management areas surrounding the TX and TY tank farms. The TX-TY tank farms are located in the 200 West Area of the US Department of Energy's Hanford Site in Washington State. The objective of the preliminary investigation was to acquire background characterization information using magnetic gradiometry (Mag) and electromagnetic induction (EM) methods to understand the spatial distribution of buried metallic objects that could potentially interfere with the results of a subsequently completed high resolution resistivity survey

  7. Frontopolar cortex and decision-making efficiency: comparing brain activity of experts with different professional background during an exploration-exploitation task

    Directory of Open Access Journals (Sweden)

    Daniella eLaureiro-Martínez

    2014-01-01

    Full Text Available An optimal balance between efficient exploitation of available resources and creative exploration of alternatives is critical for adaptation and survival. Previous studies associated these behavioral drives with, respectively, the dopaminergic mesocorticolimbic system and frontopolar-intraparietal networks. We study the activation of these systems in two age and gender-matched groups of experienced decision-makers differing in prior professional background, with the aim to understand the neural bases of individual differences in decision-making efficiency (performance divided by response time. We compare brain activity of entrepreneurs (who currently manage the organization they founded based on their venture idea and managers (who are constantly involved in making strategic decisions but have no venture experience engaged in a gambling-task assessing exploitative vs. explorative decision-making. Compared with managers, entrepreneurs showed higher decision-making efficiency, and a stronger activation in regions of frontopolar cortex previously associated with explorative choice. Moreover, activity across a network of regions previously linked to explore/exploit tradeoffs explained individual differences in choice efficiency. These results suggest new avenues for the study of individual differences in the neural antecedents of efficient decision-making.

  8. Hunting for primordial non-Gaussianity in the cosmic microwave background

    International Nuclear Information System (INIS)

    Since the first limit on the (local) primordial non-Gaussianity parameter, fNL, was obtained from the Cosmic Background Explorer (COBE) data in 2002, observations of the cosmic microwave background (CMB) have been playing a central role in constraining the amplitudes of various forms of non-Gaussianity in primordial fluctuations. The current 68% limit from the 7-year data of the Wilkinson Microwave Anisotropy Probe (WMAP) is fNL = 32 ± 21, and the Planck satellite is expected to reduce the uncertainty by a factor of 4 in a few years from now. If fNL >> 1 is found by Planck with high statistical significance, all single-field models of inflation would be ruled out. Moreover, if the Planck satellite finds fNL ∼ 30, then it would be able to test a broad class of multi-field models using the 4-point function (trispectrum) test of τNL ≥ (6fNL/5)2. In this paper, we review the methods (optimal estimator), results (WMAP 7-year) and challenges (secondary anisotropy, second-order effect and foreground) of measuring primordial non-Gaussianity from the CMB data, present a science case for the trispectrum and conclude with future prospects.

  9. Clustering of the Diffuse Infrared Light from the COBE DIRBE maps; 3, Power spectrum analysis and excess isotropic component of fluctuations

    CERN Document Server

    Kashlinsky, A; Odenwald, S

    1999-01-01

    The cosmic infrared background (CIB) radiation is the cosmic repository for energy release throughout the history of the universe. Using the all-sky data from the COBE DIRBE instrument at wavelengths 1.25 - 100 mic we attempt to measure the CIB fluctuations. In the near-IR, foreground emission is dominated by small scale structure due to stars in the Galaxy. There we find a strong correlation between the amplitude of the fluctuations and Galactic latitude after removing bright foreground stars. Using data outside the Galactic plane ($|b| > 20\\deg$) and away from the center ($90\\deg< l <270\\deg$) we extrapolate the amplitude of the fluctuations to cosec$|b|=0$. We find a positive intercept of $\\delta F_{\\rm rms} = 15.5^{+3.7}_{-7.0},5.9^{+1.6}_{-3.7}, 2.4^{+0.5}_{-0.9}, 2.0^{+0.25}_{-0.5}$ nW/m2/sr at 1.25, 2.2,3.5 and 4.9 mic respectively, where the errors are the range of 92% confidence limits. For color subtracted maps between band 1 and 2 we find the isotropic part of the fluctuations at $7.6^{+1.2}_...

  10. Cosmic Ray Exposure & Linear-Energy-Transfer Evaluations for the COBE Mission

    Science.gov (United States)

    Stassinopoulos, E. G.; Barth, J. M.

    1984-01-01

    Magnetospherically attenuated, orbit integrated, surface incident cosmic ray fluxes of galactic origin were determined for the COBE mission. All heavy ions up to Nickel (z=28) were considered in this, evaluation. In order to provide worst case approximations, estimates were based on solar minimum conditions. Transport and material shielding calculations were then performed for these vehicle encountered particles, for a simple spherical 3-D aluminum geometry, and the materially attenuated cosmic ray distributions emerging behind selected shield thicknesses were obtained. Finally, Linear-Energy-Transfer (LET) spectra were evaluated for the energy spectra of each ion specie and these were, in turn, integrated into the sum-total LET distribution contained in this report. The results are presented in tabular and graphical form for eight (8) different shield thicknesses from.01 to 10.0 gm/cm2 of aluminum. They show most conclusively, and not unexpectedly, that material shielding has virtually no 'effect on the final LET spectrum, at least not for aluminum shields. This was predictable. Please note that in the LET graphs, two curves were plotted. Of these, please ignore the one labeled "grazing" and use only the one labeled "normal". Again, it should be remembered that the end results contain contributions from all elements up to Nickel (z=28).

  11. [Cosmic Microwave Background (CMB) Anisotropies

    Science.gov (United States)

    Silk, Joseph

    1998-01-01

    One of the main areas of research is the theory of cosmic microwave background (CMB) anisotropies and analysis of CMB data. Using the four year COBE data we were able to improve existing constraints on global shear and vorticity. We found that, in the flat case (which allows for greatest anisotropy), (omega/H)0 less than 10-7, where omega is the vorticity and H is the Hubble constant. This is two orders of magnitude lower than the tightest, previous constraint. We have defined a new set of statistics which quantify the amount of non-Gaussianity in small field cosmic microwave background maps. By looking at the distribution of power around rings in Fourier space, and at the correlations between adjacent rings, one can identify non-Gaussian features which are masked by large scale Gaussian fluctuations. This may be particularly useful for identifying unresolved localized sources and line-like discontinuities. Levin and collaborators devised a method to determine the global geometry of the universe through observations of patterns in the hot and cold spots of the CMB. We have derived properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We represent results for angular resolutions ranging from 5 arcmin to 20 arcmin (antenna FWHM), scales that are relevant for the MAP and COBRA/SAMBA space missions and the ground-based interferometer. Results related to galaxy formation and evolution are also discussed.

  12. [Cosmic Microwave Background (CMB) Anisotropies

    Science.gov (United States)

    Silk, Joseph

    1998-01-01

    One of the main areas of research is the theory of cosmic microwave background (CMB) anisotropies and analysis of CMB data. Using the four year COBE data we were able to improve existing constraints on global shear and vorticity. We found that, in the flat case (which allows for greatest anisotropy), (omega/H)0 less than 10(exp -7), where omega is the vorticity and H is the Hubble constant. This is two orders of magnitude lower than the tightest, previous constraint. We have defined a new set of statistics which quantify the amount of non-Gaussianity in small field cosmic microwave background maps. By looking at the distribution of power around rings in Fourier space, and at the correlations between adjacent rings, one can identify non-Gaussian features which are masked by large scale Gaussian fluctuations. This may be particularly useful for identifying unresolved localized sources and line-like discontinuities. Levin and collaborators devised a method to determine the global geometry of the universe through observations of patterns in the hot and cold spots of the CMB. We have derived properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We represent results for angular resolutions ranging from 5 arcmin to 20 arcmin (antenna FWHM), scales that are relevant for the MAP and COBRA/SAMBA space missions and the ground-based interferometer. Results related to galaxy formation and evolution are also discussed.

  13. Can the lack of symmetry in the COBE/DMR maps constrain the topology of the universe?

    OpenAIRE

    de Oliveira-Costa, Angelica; Smoot, George F.; Starobinsky, Alexei A.

    1995-01-01

    Although the cubic T^3 "small universe" has been ruled out by COBE/DMR results as an interesting cosmological model, we still have the possibility of living in a universe with a more anisotropic topology such as a rectangular T^3 "small universe" with one or two of its dimensions significantly smaller than the present horizon (which we refer to as T^1- and T^2-models, respectively). In order to rule out these anisotropic topologies as well, we apply a new data analysis method that searches fo...

  14. A Search for Resonant Structures in the Zodiacal Cloud with COBE DIRBE: The Mars Wake and Jupiter's Trojan Clouds

    OpenAIRE

    Kuchner, Marc J.; Reach, William T.; Brown, Michael E.

    2000-01-01

    We searched the COBE DIRBE Sky and Zodi Atlas for a wake of dust trailing Mars and for Trojan dust near Jupiter's L5 Lagrange point. We compare the DIRBE images to a model Mars wake based on the empirical model of the Earth's wake as seen by the DIRBE and place a 3-sigma upper limit on the fractional overdensity of particles in the Mars wake of 18% of the fractional overdensity trailing the Earth. We place a 3-sigma upper limit on the effective emitting area of large (10-100 micron diameter) ...

  15. On the Nature of the Microwave Background at the Lagrange 2 Point. Part II

    Directory of Open Access Journals (Sweden)

    Borissova L.

    2007-10-01

    Full Text Available In this work the mathematical methods of General Relativity are used to answer the following questions: if a microwave background originates from the Earth, what would be its density and associated dipole measured at the altitude of a U2 aeroplane (25 km, the COBE satellite (900 km, and the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites? The first problem is solved via Einstein’s equations for the electromagnetic field of the Earth. The second problem is solved using the geodesic equations for light-like particles (photons which are mediators for electromagnetic radiation. We have determined that a microwave background that originates at the Earth (the Earth microwave background decreases with altitude so that the density of the energy of such a background at the altitude of the COBE orbit (900 km is 0.68 times less than that at the altitude of a U2 aeroplane. The density of the energy of the background at the L2 point is only ~1E-7 of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the Earth microwave background, due to the rapid motion of the Earth relative to the source of another field which isn’t connected to the Earth but is located in depths of the cosmos, doesn’t depend on altitute from the surface of the Earth. Such a dipole will be the same irrespective of the position at which measurements are taken.

  16. SURFACE GEOPHYSICAL EXPLORATION OF TX-TY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH GROUND PENETRATING RADAR

    Energy Technology Data Exchange (ETDEWEB)

    MYERS DA; CUBBAGE R; BRAUCHLA R; O' BRIEN G

    2008-07-24

    Ground penetrating radar surveys of the TX and TY tank farms were performed to identify existing infrastructure in the near surface environment. These surveys were designed to provide background information supporting Surface-to-Surface and Well-to-Well resistivity surveys of Waste Management Area TX-TY. The objective of the preliminary investigation was to collect background characterization information with GPR to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity{trademark} surveys. The results of the background characterization confirm the existence of documented infrastructure, as well as highlight locations of possible additional undocumented subsurface metallic objects.

  17. SURFACE GEOPHYSICAL EXPLORATION OF TX-TY TANK FARMS AT THE HANFORD SITE: RESULTS OF BACKGROUND CHARACTERIZATION WITH GROUND PENETRATING RADAR

    International Nuclear Information System (INIS)

    Ground penetrating radar surveys of the TX and TY tank farms were performed to identify existing infrastructure in the near surface environment. These surveys were designed to provide background information supporting Surface-to-Surface and Well-to-Well resistivity surveys of Waste Management Area TX-TY. The objective of the preliminary investigation was to collect background characterization information with GPR to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity(trademark) surveys. The results of the background characterization confirm the existence of documented infrastructure, as well as highlight locations of possible additional undocumented subsurface metallic objects

  18. Re-imagining otherness : an exploration of the global imaginaries of children from immigrant backgrounds in primary schools in France and England.

    OpenAIRE

    Welply, O.

    2015-01-01

    This article examines the role of global representations in immigrant-background children’s social imaginaries in primary schools in France and England. Increased globalisation, mobility and migration hold strong implications in terms of identity and belonging for children from immigrant backgrounds in schools in European countries, based on traditionally monocultural educational systems. However, most studies of immigrant children’s identities are restricted to national frameworks which over...

  19. National Research Council Dialogue to Assess Progesss on NASA's Human Exploration Systems and Mobility Capability Roadmap Development: General Background and Introduction

    Science.gov (United States)

    Inman, Thomas

    2005-01-01

    General Background and Introduction of Capability Roadmaps: Agency Objective. Strategic Planning Transformation. Advanced Planning Organizational Roles. Public Involvement in Strategic Planning. Strategic Roadmaps and Schedule. Capability Roadmaps and Schedule. Technology and Capability Readiness Levels. Relationships Between Roadmaps. Purpose of NRC Review. Capability Roadmap Development (Team Progress to Date).

  20. On the Nature of the Microwave Background at the Lagrange 2 Point. Part II

    OpenAIRE

    Borissova L.; Rabounski D.

    2007-01-01

    In this work the mathematical methods of General Relativity are used to answer the following questions: if a microwave background originates from the Earth, what would be its density and associated dipole measured at the altitude of a U2 aeroplane (25 km), the COBE satellite (900 km), and the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites)? The first problem is solved via Einstein’s equations for the electromagnetic field of the Earth. The secon...

  1. Deep-sequencing method for quantifying background abundances of symbiodinium types: exploring the rare symbiodinium biosphere in reef-building corals.

    Directory of Open Access Journals (Sweden)

    Kate M Quigley

    Full Text Available The capacity of reef-building corals to associate with environmentally-appropriate types of endosymbionts from the dinoflagellate genus Symbiodinium contributes significantly to their success at local scales. Additionally, some corals are able to acclimatize to environmental perturbations by shuffling the relative proportions of different Symbiodinium types hosted. Understanding the dynamics of these symbioses requires a sensitive and quantitative method of Symbiodinium genotyping. Electrophoresis methods, still widely utilized for this purpose, are predominantly qualitative and cannot guarantee detection of a background type below 10% of the total Symbiodinium population. Here, the relative abundances of four Symbiodinium types (A13, C1, C3, and D1 in mixed samples of known composition were quantified using deep sequencing of the internal transcribed spacer of the ribosomal RNA gene (ITS-2 by means of Next Generation Sequencing (NGS using Roche 454. In samples dominated by each of the four Symbiodinium types tested, background levels of the other three types were detected when present at 5%, 1%, and 0.1% levels, and their relative abundances were quantified with high (A13, C1, D1 to variable (C3 accuracy. The potential of this deep sequencing method for resolving fine-scale genetic diversity within a symbiont type was further demonstrated in a natural symbiosis using ITS-1, and uncovered reef-specific differences in the composition of Symbiodinium microadriaticum in two species of acroporid corals (Acropora digitifera and A. hyacinthus from Palau. The ability of deep sequencing of the ITS locus (1 and 2 to detect and quantify low-abundant Symbiodinium types, as well as finer-scale diversity below the type level, will enable more robust quantification of local genetic diversity in Symbiodinium populations. This method will help to elucidate the role that background types have in maximizing coral fitness across diverse environments and in

  2. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia;

    2016-01-01

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  3. The extragalactic background and its fluctuations in the far-infrared wavelengths

    CERN Document Server

    Lagache, G; Abergel, A; Bouchet, F R; Boulanger, F; Ciliegi, P; Clements, D L; Césarsky, C J; Désert, F X; Dole, H; Elbaz, D; Franceschini, A; Gispert, R; Guiderdoni, B; Haffner, L M; Harwit, M; Laureijs, R J; Lemke, D; Moorwood, A F M; Oliver, S; Reach, W T; Reynolds, R J; Rowan-Robinson, M; Stickel, M; Tufte, S L

    2000-01-01

    A Cosmic Far-InfraRed Background (CFIRB) has long been predicted that wouldtraces the intial phases of galaxy formation. It has been first detected byPuget et al.(1996) using COBE data and has been later confirmed by severalrecent studies (Fixsen et al. 1998, Hauser et al. 1998, Lagache et al. 1999).We will present a new determination of the CFIRB that uses for the first time,in addition to COBE data, two independent gas tracers: the HI survey ofLeiden/Dwingeloo (hartmann, 1998) and the WHAM H$_{\\alpha}$ survey (Reynolds etal 1998). We will see that the CFIRB above 100 micron is now very wellconstrained. The next step is to see if we can detect its fluctuations. Tosearch for the CFIRB fluctuations, we have used the FIRBACK observations.FIRBACK is a deep cosmological survey conducted at 170 micron with ISOPHOT(Dole et al., 2000). We show that the emission of unresolved extra-galacticsources clearly dominates, at arcminute scales, the background fluctuations inthe lowest galactic emission regions. This is the f...

  4. Cold dark matter confronts the cosmic microwave background - Large-angular-scale anisotropies in Omega sub 0 + lambda 1 models

    Science.gov (United States)

    Gorski, Krzysztof M.; Silk, Joseph; Vittorio, Nicola

    1992-01-01

    A new technique is used to compute the correlation function for large-angle cosmic microwave background anisotropies resulting from both the space and time variations in the gravitational potential in flat, vacuum-dominated, cold dark matter cosmological models. Such models with Omega sub 0 of about 0.2, fit the excess power, relative to the standard cold dark matter model, observed in the large-scale galaxy distribution and allow a high value for the Hubble constant. The low order multipoles and quadrupole anisotropy that are potentially observable by COBE and other ongoing experiments should definitively test these models.

  5. The music of the Big Bang the cosmic microwave background and the new cosmology

    CERN Document Server

    Balbi, Amedeo

    2008-01-01

    The cosmic microwave background radiation is the afterglow of the big bang: a tenuous signal, more than 13 billion years old, which carries the answers to many of the questions about the nature of our Universe. It was serendipitously discovered in 1964, and thoroughly investigated in the last four decades by a large number of experiments. Two Nobel Prizes in Physics have already been awarded for research on the cosmic background radiation: one in 1978 to Arno Penzias and Robert Wilson, who first discovered it, the other in 2006, to George Smoot and John Mather, for the results of the COBE satellite. Most cosmological information is encoded in the cosmic background radiation by acoustic oscillations in the dense plasma that filled the primordial Universe: a "music" of the big bang, which cosmologists have long been trying to reconstruct and analyze, in order to distinguish different cosmological models, much like one can distinguish different musical instruments by their timbre and overtones. Only lately, this...

  6. Mapping the cold glow of the big bang

    International Nuclear Information System (INIS)

    The United States has recently launched a satellite solely dedicated to cosmology in an attempt to provide insight into the early formation of the Universe. The Cosmic Background Explorer (COBE) satellite is producing astonishing precise data which supports the Big Bang theory of the Universe's origins. Continued analysis of COBE data may provide clues as to how stars and galaxies formed. (UK)

  7. On the origin of the cosmic microwave background anisotropies

    CERN Document Server

    Follop, Ria; Cooray, Asantha; Abdalla, Filipe B

    2007-01-01

    Suggestions have been made that the microwave background observed by COBE and WMAP and dubbed Cosmic Microwave Background (CMB) may have an origin within our own Galaxy or Earth. To consider the signal that may be correlated with Earth, a correlate-by-eye exercise was attempted by overlaying the CMB map from Wilkinson Microwave Anisotropy Probe on a topographical map of Earth. Remarkably, several hot spots in the CMB map are found to be well aligned with either large cities on Earth or regions of high altitude. To further study the correlations between Earth and CMB, we performed a complicated cross-correlation analysis in the multipole space. The overall correlations are detected at more than 5 sigma confidence level. These results can be naively interpreted to suggest that large angular scale fluctuations in CMB are generated on Earth by a process that traces the altitude relative to a mean radius. Simply extending our analysis, we suggest that cross-correlations between CMB and any other map of a Solar sys...

  8. 大数据背景下物联电子商务新模式的探索%Under the background of big data to explore the new model of the internet of things e-commerce

    Institute of Scientific and Technical Information of China (English)

    都伊林

    2013-01-01

    This paper analyzes the connotation and application status quo of big data,and combined with the large data characteristics, the Internet of things and cloud computing technology, and analysis the value chain theory of the e-commerce, it puts forward the new idea and new mode of the internet of things e-commerce. According to the value chain theory of e-commerce,it analyzes the vertical and horizontal value chain,and explore under the background of big data the new model of the internet of things e-commerce. Application of large data intelligent processing technology to determine the correlation of enterprise management information-behavior fingerprints, It forms the intelligent system of value creation. Therefore, for enterprises to choose business model in theory as well as the transformation and upgrading of industries to provide a certain basis.%文章分析了大数据的内涵和应用现状,结合大数据、物联网和云计算等技术特点,分析电子商务价值链理论,提出了物联电子商务的新理念与新模式。根据电子商务的价值链理论,分析了纵向和横向价值链构成,探索大数据背景下物联电子商务的新模式;应用大数据智能处理技术能确定企业经营的相关性信息---行为指纹,形成智能型价值创造体系,因此,从理论上为企业选择经营模式以及产业转型升级提供一定的依据。

  9. Large-scale polarization of the microwave background and foreground

    International Nuclear Information System (INIS)

    The DASI discovery of cosmic microwave background (CMB) polarization has opened a new chapter in cosmology. Most of the useful information about inflationary gravitational waves and reionization is on large angular scales where galactic foreground contamination is the worst, so a key challenge is to model, quantify, and remove polarized foregrounds. We use the POLAR experiment, COBE/DMR and radio surveys to provide the strongest limits to date on the TE cross-power spectrum of the CMB on large angular scales and to quantify the polarized synchrotron radiation, which is likely to be the most challenging polarized contaminant for the WMAP satellite. We find that the synchrotron E and B contributions are equal to within 10% from 408-820 MHz with a hint of E domination at higher frequencies. We quantify Faraday rotation and depolarization effects in the two-dimensional (l,ν) plane and show that they cause the synchrotron polarization percentage to drop both towards lower frequencies and towards lower multipoles

  10. On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: III. Galactic far-infrared radiation

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Using the three-component spectral model describing the FIRAS average continuum spectra, the analytical expressions for the temperature dependence of the thermodynamic and radiative functions of the galactic far-infrared radiation are obtained. The COBE FIRAS instrument data in the 0.15 - 2.88 THz frequency interval at the mean temperatures T = 17.72 K, T = 14 K, and T =6.73 K are used for calculating the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, total emissivity, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume and pressure for the warm, intermediate-temperature and very cold components of the Galactic continuum spectra. The generalized Stefan-Boltzmann laws for the warm, intermediate-temperature and very cold components are constructed. This result is important when we construct the cosmological models of radiative transfer in the inner Galaxy. Within the framework of the three- com...

  11. The Cosmic Microwave Background Anisotropy Experiments

    OpenAIRE

    Smoot, George F.

    1997-01-01

    This paper reports a summary of the contents contents of six hours of lectures on the CMB anisotropy experiments given at the Strasbourg NATO school on the CMB and cosmology. (Its companion paper, astro-ph/9705101 reports the lectures on the CMB spectrum.) A context is set as a bridge from the theoretical CMB anisotropy lectures and the experimental situation. The COBE DMR results are reveiwed in detail and as pioneer for future space missions. Current and planned experiments are discussed in...

  12. Hanford Site background: Part 3, Groundwater background

    International Nuclear Information System (INIS)

    This report presents and interprets groundwater background data collected from the unconfined aquifer beneath the Hanford Site, a U.S. Department of Energy complex located near Richland, Washington. Characterization of background composition is an important component of environmental characterization activities and serves as a basis for distinguishing the presence and significance of contamination. Background data can also be used to assess the levels of baseline risk to which humans or other receptors are typically exposed and to establish remediation goals. Evaluating background on a sitewide basis provides a consistent, technically defensible definition of background as opposed to determining area-specific background compositions for each waste management unit being considered for remediation across the Hanford Site

  13. 大数据下的卫星城镇交通与土地空间规划探索%Exploration of traffic & land space planning for satellite towns against the background of big data

    Institute of Scientific and Technical Information of China (English)

    谭杰

    2015-01-01

    随着计算机技术不断发展,大数据应用已成为当下热点研究领域,其高速精确的数据分析能力给许多研究提供了极大的帮助,本文希望借助大数据技术对卫星城镇的空间规划问题的解决做出一定的参考。  卫星城镇不同于普通城市,其意是大城市周边的小型城市,目的在于为大城市工作者提供居住地,因此,卫星城镇的空间规划相对与普通大中城市比较简单,其交通结构与功能区都不如大城市的复杂。本文基于卫星城镇的特点,通过分析归纳相关大数据技术的内容与空间划分中使用的手段与方法,主要对交通和功能区土地规划两方面进行探讨,总结大数据下以人为本核心理念的卫星城镇规划方式新探索。%Nowadays ,the computer technologies have been improved continuously and big data has been the popular technology ,w hose precise data analysis capability at a high speed pro‐vides many researches with the great help .In this paper ,it is hoped that the big data technol‐ogy can provide a certaln reference for space planning of satellite tow ns . Differ from the ordinary cities ,satellite tow ns refer to the small cities around the large cities .They act to provide people working in the large cities with inhabitation .Thus ,their planning is simpler than that of the ordinary medium and large cities ,and their traffic struc‐tures and functional areas are not as complicated as these of large cities .In this paper ,based on the features of satellite tow ns ,traffic and functional area land space planning have been discussed and new explorations of the human‐oriented satellite tow n planning manners in the background of bid data have been summarized in this paper by analyzing and inducing the con‐tent of relevant big data technologies and means & approaches used in space division .

  14. The Physics of the Cosmic Microwave Background

    International Nuclear Information System (INIS)

    The award of the 2006 Nobel Prize for Physics is a reminder to non-specialists that the cosmic microwave background (CMB) has yielded astonishing advances in our understanding of cosmology. Mather and Smoot received their prize for work done with NASA's COBE satellite in the early 1990s, but the subject has if anything accelerated since then. The results from NASA's WMAP satellite, reported in 2003 and 2006, have proved COBE's equal in importance and have generated huge worldwide interest. There could therefore hardly be a better time to be writing a detailed textbook to explain what the fuss is all about to a new generation of research students. A comprehensive treatment of the physics of the CMB is not easy to achieve, because it is connected to so much else in cosmology. A student must have a background knowledge of the geometry and dynamics of an expanding universe, plus a deep exposure to the physics of quantum fields, in order to understand the modern 'inflationary' view in which the universe was set expanding by the tension of the vacuum, and was seeded with small inhomogeneities as a result of quantum fluctuations. Although the theory of inflation is not yet verified, the CMB has the potential to accomplish this; testing inflation is undoubtedly one of the principal aims of cosmology over the next decade. Even with this preparation, understanding the properties of the CMB is quite hard at the professional level, requiring the perturbation expansion of the relativistic Boltzmann equation. These technical difficulties are particularly strong in the frontier area of CMB polarization. Naselsky and his collaborators have allocated themselves a relatively brief 255 pages in which to meet these challenges, so some compromise is inevitable. Although the preface is not explicit about the assumed prior knowledge, no systematic material on background cosmology or on inflation is to be found. The former is reasonable in a graduate-level text (which this certainly is

  15. WINNICOTT Y HEIDEGGER: LA APERTURA DEL MUNDO Y EL CO-ESTAR // WINNICOTT AND HEIDEGGER: OPENING UP OF WORLD AND CO-BEING

    Directory of Open Access Journals (Sweden)

    Julieta Bareiro

    2013-06-01

    Full Text Available Este trabajo integra la investigación de la tesis doctoral defendida en la Facultad de Psicología (UBA y tiene por propósito establecer un diálogo entre Winnicott y Heidegger respecto de la apertura del mundo y los otros. En efecto, ambos pensadores desde sus respectivas disciplinas han reflexionado sobre la experiencia del ser y el existir. Winnicott desde el ámbito de la clínica psicoanalítica y Heidegger desde la fenomenología hermenéutica. El hecho de que la apertura del mundo en el filósofo alemán sea compartida, permite una mayor comprensión del rol materno en el proceso del desarrollo del niño winnicottiano. A partir de la afirmación de que el Dasein es esencialmente ser con otros, co-estar, (Mitsein y que los otros son ahí con el Dasein, es posible pensar que el desarrollo de la subjetividad winnicottiana tiene el rasgo de la co-existencia. // This work integrates the research of the doctoral thesis defended at the Faculty of Psychology (UBA and aims to establish a dialogue between Winnicott and Heidegger regarding the opening up of world and the others. Indeed, both thinkers, from their respective disciplines, have thought about the experience of being and existing. Winnicott from the field of psychoanalytic clinic and Heidegger from the hermeneutic phenomenology. The fact that opening up of world in the German philosopher is shared allows a better understanding of the maternal role in the Winnicottian child development process. From the statement that Dasein is essentially being with others, co-being, (Mitsein and that others are there with the Dasein, it is conceivable that the development of the Winnicottian subjectivity has the trait of coexistence.

  16. Reading Engagement in Social Studies: Exploring the Role of a Social Studies Literacy Intervention on Reading Comprehension, Reading Self-Efficacy, and Engagement in Middle School Students with Different Language Backgrounds

    Science.gov (United States)

    Barber, Ana Taboada; Buehl, Michelle M.; Kidd, Julie K.; Sturtevant, Elizabeth G.; Nuland, Leila Richey; Beck, Jori

    2015-01-01

    The authors examined the role of an intervention designed to increase reading comprehension, reading self-efficacy beliefs, and engagement in social studies for middle school students of varying language backgrounds. Thirteen sixth- and seventh-grade teachers implemented the United States History for Engaged Reading (USHER) program with their…

  17. Are South African Speech-Language Therapists adequately equipped to assess English Additional Language (EAL speakers who are from an indigenous linguistic and cultural background? A profile and exploration of the current situation

    Directory of Open Access Journals (Sweden)

    Thandeka Mdladlo

    2016-02-01

    Full Text Available This article presents the results of a survey conducted on Speech-Language Therapists (SLTs regarding current practices in the assessment of English Additional Language (EAL speakers in South Africa. It forms part of the rationale for a broader (PhD study that critiques the use of assessment instruments on EAL speakers from an indigenous linguistic and cultural background. This article discusses an aspect of the broader research and presents the background, method, findings, discussion and implications of the survey. The results of this survey highlight the challenges of human and material resources to, and the dominance of English in, the profession in South Africa. The findings contribute to understanding critical factors for acquiring reliable and valid assessment results with diverse populations, particularly the implications from a cultural and linguistic perspective.[PDF to follow

  18. Are South African Speech-Language Therapists adequately equipped to assess English Additional Language (EAL) speakers who are from an indigenous linguistic and cultural background? A profile and exploration of the current situation.

    Science.gov (United States)

    Mdladlo, Thandeka; Flack, Penelope; Joubert, Robin

    2016-01-01

    This article presents the results of a survey conducted on Speech-Language Therapists (SLTs) regarding current practices in the assessment of English Additional Language (EAL) speakers in South Africa. It forms part of the rationale for a broader (PhD) study that critiques the use of assessment instruments on EAL speakers from an indigenous linguistic and cultural background. This article discusses an aspect of the broader research and presents the background, method, findings, discussion and implications of the survey. The results of this survey highlight the challenges of human and material resources to, and the dominance of English in, the profession in South Africa. The findings contribute to understanding critical factors for acquiring reliable and valid assessment results with diverse populations, particularly the implications from a cultural and linguistic perspective. PMID:27247254

  19. Building Background Knowledge

    Science.gov (United States)

    Neuman, Susan B.; Kaefer, Tanya; Pinkham, Ashley

    2014-01-01

    This article make a case for the importance of background knowledge in children's comprehension. It suggests that differences in background knowledge may account for differences in understanding text for low- and middle-income children. It then describes strategies for building background knowledge in the age of common core standards.

  20. Under the background of mobile Internet to explore our country enterprise brand construction problem%移动互联网背景下我国企业品牌建设问题探究

    Institute of Scientific and Technical Information of China (English)

    刘毅菲

    2015-01-01

    文章首先分析我国企业品牌建设现状,探讨企业品牌建设问题.最后,建设性提出移动互联网背景下我国企业品牌建设对策.希望本文研究,能够为进一步推进我国企业品牌建设长效机制,提供具有一定参考价值的建议.%This paper analysis the enterprise brand construction situation in our country, discusses the enterprise brand construction. Finally, constructive puts forward some countermeasures for our country enterprise brand construction under mobile Internet background. Hope that this article research, to further advance our country enterprise brand construction of long-term mechanism, to provide certain reference value for advice.

  1. Exploration on collaboration of conducting designing experiments by students in different levels of language and knowledge background%不同民族和年级的学生协作开展设计性实验的探讨

    Institute of Scientific and Technical Information of China (English)

    赵红琼; 夏利宁; 张晓红; 王金泉; 姚刚

    2013-01-01

    针对新疆少数民族学生的实际情况加强实践环节的教学,将不同年级不同民族的学生组织在一起共同完成了生理学的设计性实验.在此基础上,探讨了对不同年级和不同民族的学生开设综合性和设计性实验的体会:正确认识综合性和设计性实验;注意实验的可行性;编写翔实的实验教学大纲;合理搭配民、汉语言学生和高、低年级学生;注重对学生协作能力的培养等.这种方式既提高学生对专业知识的理解,也锻炼了他们取长补短、团结协作的能力.%Aiming at students who are in different levels of Han language and knowledge background may have the professional knowledge differently in depth and breadth,minority language-speaking students have more difficulties in understanding obscure theoretical knowledge than Han language-speaking students.Therefore the enhancement of the experimental and practical learning segments is very helpful for minority language speaking students.In order to develop the advantages of them and to train their ability of collaboration,some comprehensive and designing experiments of animal physiology were conducted by organizing students in different levels of Han language-speaking and knowledge background.The experience what the authors learned from these experiments is discussed as fallows:firstly,having all students involving in the experiments fully understanding the meaning of a comprehensive and designing experiment; secondly,preparing the experimental teaching protocol in detail; thirdly,matching students reasonably in groups by Han language and minority language speaking,different grades and genders; fourthly,laying emphasis on the cultivation of collaboration ability for all students in the experiment; finally,showing the procedure how to carry out the designing experiment,the effect of herbs from Xinjiang on animals by physiological methods.

  2. PROBING THE INFLATON: SMALL-SCALE POWER SPECTRUM CONSTRAINTS FROM MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND ENERGY SPECTRUM

    International Nuclear Information System (INIS)

    In the early universe, energy stored in small-scale density perturbations is quickly dissipated by Silk damping, a process that inevitably generates μ- and y-type spectral distortions of the cosmic microwave background (CMB). These spectral distortions depend on the shape and amplitude of the primordial power spectrum at wavenumbers k ∼4 Mpc–1. Here, we study constraints on the primordial power spectrum derived from COBE/FIRAS and forecasted for PIXIE. We show that measurements of μ and y impose strong bounds on the integrated small-scale power, and we demonstrate how to compute these constraints using k-space window functions that account for the effects of thermalization and dissipation physics. We show that COBE/FIRAS places a robust upper limit on the amplitude of the small-scale power spectrum. This limit is about three orders of magnitude stronger than the one derived from primordial black holes in the same scale range. Furthermore, this limit could be improved by another three orders of magnitude with PIXIE, potentially opening up a new window to early universe physics. To illustrate the power of these constraints, we consider several generic models for the small-scale power spectrum predicted by different inflation scenarios, including running-mass inflation models and inflation scenarios with episodes of particle production. PIXIE could place very tight constraints on these scenarios, potentially even ruling out running-mass inflation models if no distortion is detected. We also show that inflation models with sub-Planckian field excursion that generate detectable tensor perturbations should simultaneously produce a large CMB spectral distortion, a link that could potentially be established with PIXIE.

  3. Exploration on Ways of Implementing University Youth League Construction in the Background of New Media%新媒体背景下高校团建工作的开展路径探究

    Institute of Scientific and Technical Information of China (English)

    李佳; 胡万培

    2015-01-01

    随着信息化社会的到来,依托于网络技术、数字技术,移动技术等的新媒体飞速发展且逐步为大众所喜爱接受。而高校青年更是新媒体的主体,其生活方式、行为方式、交流方式等随着新媒体的发展也在不断改变。因此,新媒体的不断普及给高校共青团建设提出了新的机遇与挑战。在此背景下,了解新媒体的特点及高校青年群体的个性,明确高校团建工作开展过程中的机遇和挑战,从而更好地利用新媒体服务引导青年团员显得更为重要。%With the advent of information society, new media, re-lying on network technology, digital technology and mobile tech-nology, are developing rapidly and have gradually been favored and accepted by the public. University students are the subject of new media, so their ways of life, behavior and communication are changing with the development of new media. Therefore, the con-tinuous popularization of new media has proposed new opportu-nities and challenges for university Youth League construction. In the background, it is particularly important to learn about the characteristics of new media and the personalities of university students, and clarify the opportunities and challenges in univer-sity Youth League construction, so as to better utilize new media to serve and guide Youth League members.

  4. The Cosmic Microwave Background

    OpenAIRE

    Silk, Joseph

    2001-01-01

    This set of lectures provides an overview of the basic theory and phenomenology of the cosmic microwave background. Topics include a brief historical review; the physics of temperature and polarization fluctuations; acoustic oscillations of the primordial plasma; the space of inflationary cosmological models; current and potential constraints on these models from the microwave background; and constraints on inflation.

  5. Stealths on Anisotropic Holographic Backgrounds

    CERN Document Server

    Ayón-Beato, Eloy; Juárez-Aubry, María Montserrat

    2015-01-01

    In this paper, we are interested in exploring the existence of stealth configurations on anisotropic backgrounds playing a prominent role in the non-relativistic version of the gauge/gravity correspondence. By stealth configuration, we mean a nontrivial scalar field nonminimally coupled to gravity whose energy-momentum tensor evaluated on the anisotropic background vanishes identically. In the case of a Lifshitz spacetime with a nontrivial dynamical exponent z, we spotlight the role played by the anisotropy to establish the holographic character of the stealth configurations, i.e. the scalar field is shown to only depend on the radial holographic direction. This configuration which turns out to be massless and without integration constants is possible for a unique value of the nonminimal coupling parameter. Then, using a simple conformal argument, we map this configuration into a stealth solution defined on the so-called hyperscaling violation metric which is conformally related to the Lifshitz spacetime. Thi...

  6. Cosmogenic Backgrounds to 0{\

    CERN Document Server

    :,; Auty, D J; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dilling, J; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Feyzbakhsh, S; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Herrin, S; Hughes, M; Jewell, M J; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krücken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Njoya, O; Nelson, R; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Retière, F; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2015-01-01

    As neutrinoless double-beta decay experiments become more sensitive and intrinsic radioactivity in detector materials is reduced, previously minor contributions to the background must be understood and eliminated. With this in mind, cosmogenic backgrounds have been studied with the EXO-200 experiment. Using the EXO-200 TPC, the muon flux (through a flat horizontal surface) underground at the Waste Isolation Pilot Plant (WIPP) has been measured to be {\\Phi} = 4.07 $\\pm$ 0.14 (sys) $\\pm$ 0.03 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$, with a vertical intensity of $I_{v}$ = 2.97$^{+0.14}_{-0.13}$ (sys) $\\pm$ 0.02 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$ sr$^{-1}$. Simulations of muon-induced backgrounds identified several potential cosmogenic radionuclides, though only 137Xe is a significant background for the 136Xe 0{\

  7. On Background Independence

    OpenAIRE

    Anderson, Edward

    2013-01-01

    This paper concerns what Background Independence itself is (as opposed to some particular physical theory that is background independent). The notions presented mostly arose from a layer-by-layer analysis of the facets of the Problem of Time in Quantum Gravity. Part of this coincides with two relational postulates which are thus identified as classical precursors of two of the facets of the Problem of Time. These are furthemore tied to the forms of each of the GR Hamiltonian and momentum cons...

  8. Zambia Country Background Report

    DEFF Research Database (Denmark)

    Hampwaye, Godfrey; Jeppesen, Søren; Kragelund, Peter

    This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change).......This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change)....

  9. Determination of background radiation

    International Nuclear Information System (INIS)

    The invention relates to a method and appartus for determining the level of background radiation in a spectral region where a Raman peak characteristic of a particular substance, in particular diamond, is expected to occur. The method includes the steps of isolating the radiation in a first spectral band, and isolating the radiation in a second spectral band which overlaps the first spectral band at least partially to form an overlapping band in the vicinity of the expected Raman Peak and a least one sideband. At least one sideband value representative of the radiation present in the one or more sidebands is then obtained, and further values, representative of the radiation isolated by any one or more of the other spectral bands, such as the first and second bands, are then used to derive a background value indicative of the level of background radiation present at the position of the expected Raman peak

  10. Unitarity and singular backgrounds

    CERN Document Server

    Brouzakis, Nikos

    2013-01-01

    We compute the graviton Kaluza-Klein spectrum on a gravity-dilaton background with a naked singularity for all possible boundary conditions at the singularity which are consistent with unitary evolution. We apply methods from non-relativistic quantum mechanics with singular Schr\\"{o}dinger potentials. In general the spectrum contains a tachyon, a sign of instability. Only for a particular boundary condition at the singularity the spectrum is free of tachyons. In this case the lowest-lying graviton mode is massless. We argue that this result will also hold for other backgrounds with similar geometry near the curvature singularity. We complete our study with a brief discussion on radion perturbations and Higgs mechanism on this singular background.

  11. Cosmic Tachyon Background Radiation

    CERN Document Server

    Tomaschitz, R

    1999-01-01

    The equilibrium statistical mechanics of a background radiation of superluminal particles is investigated, based on a vectorial wave equation for tachyons of the Proca type. The partition function, the spectral energy density, and the various thermodynamic variables of an ideal Bose gas of tachyons in an open Robertson-Walker cosmology are derived. The negative mass square in the wave equation changes the frequency scaling in the Rayleigh-Jeans law, and there are also significant changes in the low temperature regime as compared to the microwave background, in particular in the caloric and thermal equations of state.

  12. The natural radiation background

    International Nuclear Information System (INIS)

    The components of the natural background radiation and their variations are described. Cosmic radiation is a major contributor to the external dose to the human body whilst naturally-occurring radionuclides of primordial and cosmogenic origin contribute to both the external and internal doses, with the primordial radionuclides being the major contributor in both cases. Man has continually modified the radiation dose to which he has been subjected. The two traditional methods of measuring background radiation, ionisation chamber measurements and scintillation counting, are looked at and the prospect of using thermoluminescent dosimetry is considered

  13. The infrared and submillimetre sky after COBE; Proceedings of the NATO Advanced Study Institute, Les Houches, France, Mar. 20-30, 1991

    Science.gov (United States)

    Signore, Monique; Dupraz, Christophe

    The present conference discusses first-order cosmological inflation, the great attractor and the anisotropies of the relic radiation, the role of string theory in cosmology, the cosmic microwave background radiation, dark matter candidates and candidate detection methods, and the thermal history of the cosmological gas. Also discussed are Galactic IR emission, sources of cosmic IR-to-submillimeter background radiation, cosmic background anisotropies in the millimetric region, and linear and nonlinear gravitational effects on the cosmic microwave background.

  14. Spitzer and DIRBE Studies of the Infrared Background

    Science.gov (United States)

    Werner, Michael; Gorjian, Varoujan; Hauser, Michael; Wright, Edward; Arendt, Rick; Chary, Ranga-Ram; Levenson, Louis

    2011-05-01

    The extragalactic background light (EBL), defined as the sky surface brightness of all radiation arising from outside the Milky Way, carries in the 1-5um region the imprint of the nearby Universe, of red-shifted light from the first galaxies, and of any possible pre-galactic contributions. The DIRBE instrument on the COBE satellite has measured the total sky brightness, the Cosmic Infrared Background (CIRB), over the entire sky at 3.6um. The CIRB is the sum of the zodiacal light, galactic starlight, radiation from the ISM, and the EBL. Although the determinations of the EBL are presently limited by uncertainties in the zodiacal light model, experiments now under way can reduce those uncertainties. This Spitzer proposal prepares for that reduction by eliminating other uncertainties. We will use Spitzer to determine the point source components of CIRB at 3.6um, the wavelength of the minimum in the bright foreground from interplanetary dust. We will measure essentially all of the stellar contribution, and more than 80% of the integrated light from resolved galaxies; this can be extrapolated using other Spitzer data to determine IGL. The ultimate objective of this type of study is to search for a currently unknown diffuse component of EBL, DEBL. Symbolically, DEBL = EBL-IGL. In this program, we will execute the following steps aimed at reducing the uncertainties in DEBL once the zodiacal uncertainty in CIRB is minimized and a correction for ISM emission is applied: 1. Cross calibrating DIRBE and Spitzer so that EBL and IGL are on the same flux scale; 2. Reducing the uncertainties in EBL by measuring stars as faint as 19th mag at 3.6um. 3. Determining EBL and IGL at six widely separated positions so that the isotropy - and hence the cosmological significance - of any detection of DEBL can be assessed. We emphasize that this important investigation can be carried out only with Spitzer, and this scientific opportunity is perishable due to Spitzer's finite lifetime.

  15. Berkeley Low Background Facility

    International Nuclear Information System (INIS)

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

  16. Local microwave background radiation

    OpenAIRE

    Soares, Domingos

    2006-01-01

    An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

  17. Berkeley Low Background Facility

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K. J.; Norman, E. B. [Department of Nuclear Engineering, University of California-Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, CA 94720 (United States); Smith, A. R.; Poon, A. W. P.; Chan, Y. D. [Nuclear Science Division, Lawrence Berkeley National Laboratory, CA 94720 (United States); Lesko, K. T. [Physics Division, Lawrence Berkeley National Laboratory, CA 94720 (United States)

    2015-08-17

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  18. Cosmological Parameters from Cosmic Background Imager Observations and Comparisons with BOOMERANG, DASI, and MAXIMA

    CERN Document Server

    Sievers, J L; Cartwright, J K; Contaldi, C R; Mason, B S; Myers, S T; Padin, S; Pearson, T J; Pen, U L; Pogosyan, D; Prunet, S; Readhead, A C S; Shepherd, M C; Udomprasert, P S; Bronfman, L; Holzapfel, W L; May, J

    2003-01-01

    We report on the cosmological parameters derived from observations with the Cosmic Background Imager (CBI), covering 40 square degrees and the multipole range 300 <~ l <~ 3500. These unique, high-resolution observations show the seeds that gave rise to clusters of galaxies and also show damping in the power spectrum to l ~ 2000. Because the observations extend to much higher l the CBI results provide information complementary to that probed by the BOOMERANG, DASI, and MAXIMA experiments. When the CBI observations are used in combination with those from COBE-DMR, we find evidence for a flat universe, Omega(tot)=0.99 +/- 0.12 (1-sigma), a power law index of primordial fluctuations, n_s = 1.05(-0.08,+0.09), and densities in cold dark matter, Omega(cdm)h^2 = 0.17(-0.06,+0.08), and baryons, Omega(b)h^2 = 0.022(-0.009,+0.15). With the addition of large scale structure priors the Omega(cdm)h^2 value is sharpened to 0.12(-0.03,+0.03), and we find Omega(Lambda) = 0.64(-0.14,+0.11). In the l < 1000 overlap reg...

  19. The optimisation, design and verification of feed horn structures for future Cosmic Microwave Background missions

    Science.gov (United States)

    McCarthy, Darragh; Trappe, Neil; Murphy, J. Anthony; O'Sullivan, Créidhe; Gradziel, Marcin; Doherty, Stephen; Huggard, Peter G.; Polegro, Arturo; van der Vorst, Maarten

    2016-05-01

    In order to investigate the origins of the Universe, it is necessary to carry out full sky surveys of the temperature and polarisation of the Cosmic Microwave Background (CMB) radiation, the remnant of the Big Bang. Missions such as COBE and Planck have previously mapped the CMB temperature, however in order to further constrain evolutionary and inflationary models, it is necessary to measure the polarisation of the CMB with greater accuracy and sensitivity than before. Missions undertaking such observations require large arrays of feed horn antennas to feed the detector arrays. Corrugated horns provide the best performance, however owing to the large number required (circa 5000 in the case of the proposed COrE+ mission), such horns are prohibitive in terms of thermal, mechanical and cost limitations. In this paper we consider the optimisation of an alternative smooth-walled piecewise conical profiled horn, using the mode-matching technique alongside a genetic algorithm. The technique is optimised to return a suitable design using efficient modelling software and standard desktop computing power. A design is presented showing a directional beam pattern and low levels of return loss, cross-polar power and sidelobes, as required by future CMB missions. This design is manufactured and the measured results compared with simulation, showing excellent agreement and meeting the required performance criteria. The optimisation process described here is robust and can be applied to many other applications where specific performance characteristics are required, with the user simply defining the beam requirements.

  20. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  1. Unitarity and singular backgrounds

    OpenAIRE

    Brouzakis, Nikos; Quiros, Mariano

    2013-01-01

    We compute the graviton Kaluza-Klein spectrum on a gravity-dilaton background with a naked singularity for all possible boundary conditions at the singularity which are consistent with unitary evolution. We apply methods from non-relativistic quantum mechanics with singular Schr\\"{o}dinger potentials. In general the spectrum contains a tachyon, a sign of instability. Only for a particular boundary condition at the singularity is the spectrum free of tachyons. In this case the lowest-lying gra...

  2. Australia; Background Material

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This paper describes the developments in the Australian labor market during the 1990s. In 1994, a number of new labor market programs were launched, directed especially at the long-term unemployed, and a further step was taken in the evolutionary reform of the industrial relations system. The paper reviews developments in employment, wages, and productivity in Australia that formed the background to these policy initiatives. It also examines the conduct of fiscal policy at the Commonwealth an...

  3. Sri Lanka; Background Papers

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This Background Paper on Sri Lanka provides information on the economic developments during 1992–95. Developments in the domestic and external sectors are discussed. The deficiencies of the official consumer price index that resulted in a substantial understatement of inflation performance in 1994 and alternative estimates of underlying inflation are described. The structural rigidities in the labor market that perpetuate high unemployment and limit job growth are also described. The paper ...

  4. Background, phenomenology, and motivation

    International Nuclear Information System (INIS)

    The authors discuss the background to the kinetics of adsorption and desorption after an elementary introduction to the problem of chemisorption in two limiting cases. Other topics discussed include the thermodynamics of adsorption, reaction mechanisms outside surfaces, and a case history of catalytic hydrogenation of carbon monoxide. Figures show the potential energy barrier as a function of an appropriate reaction coordinate, and bonding of carbon monoxide to platinum metal

  5. Some background about satellites

    Science.gov (United States)

    Burns, Joseph A.

    1986-01-01

    Four tables of planetary and satellite data are presented which list satellite discoveries, planetary parameters, satellite orbits, and satellite physical properties respectively. A scheme for classifying the satellites is provided and it is noted that most known moons fall into three general classes: regular satellites, collisional shards, and irregular satellites. Satellite processes are outlined with attention given to origins, dynamical and thermal evolution, surface processes, and composition and cratering. Background material is provided for each family of satellites.

  6. The Cosmic Microwave Background Anisotropy Experiments

    CERN Document Server

    Smoot, G F

    1997-01-01

    This paper reports a summary of the contents contents of six hours of lectures on the CMB anisotropy experiments given at the Strasbourg NATO school on the CMB and cosmology. (Its companion paper, astro-ph/9705101 reports the lectures on the CMB spectrum.) A context is set as a bridge from the theoretical CMB anisotropy lectures and the experimental situation. The COBE DMR results are reveiwed in detail and as pioneer for future space missions. Current and planned experiments are discussed in preference to reviewing already completed observations. The NASA MidEX mission MAP is discussed in some detail including figures. The ESA M3 mission Max Planck Surveyor is also reviewed in some detail though its final configuration is not yet fully settled. The recent history and current versions are presented. Tables and references for experiments are included.

  7. Backgrounded but not peripheral

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    DDAs in question contribute to the socio-cultural construction of identity, i.e. that they play a rather specific role in discursive communication and socio-cultural meaning construction. On the other hand it is clear that the semantics of the DDAs in question, seen in isolation, is very abstract or...... general; furthermore, the DDAs are backgrounded in discourse. Is it reasonable to claim, rather boldly, that “the informants express their identity in the use of the directional adverb ud ‘out’ etc.”? In the course of this article, however, I suggest that the DDAs in question do contribute to the socio-cultural...

  8. The Cosmic Background Radiation

    OpenAIRE

    Smoot, George; Scott, Douglas

    1997-01-01

    We review the current status of experimental data for spectral distortions and angular anisotropies of the cosmic microwave background, as well as discussing the relevant physical processes. This is one of a number of new articles in astrophysics and cosmology which will appear in the 1996 Review of Particle Properties (Phys. Rev. D. in press). Other relevant reviews include: "Big-Bang Cosmology" by K.A. Olive; "Big-Bang Nucleosynthesis" by K.A. Olive & D.N. Schramm; "The Hubble Constant" by ...

  9. Malaysia; Background Paper

    OpenAIRE

    International Monetary Fund

    1996-01-01

    This Background Paper on Malaysia examines developments and trends in the labor market since the mid-1980s. The paper describes the changes in the employment structure and the labor force. It reviews wages and productivity trends and their effects on unit labor cost. The paper highlights that Malaysia’s rapid growth, sustained since 1987, has had a major impact on the labor market. The paper outlines the major policy measures to address the labor constraints. It also analyzes Malaysia’s r...

  10. Background and introduction

    DEFF Research Database (Denmark)

    Jensen, Per Anker; van der Voordt, Theo; Coenen, Christian

    2012-01-01

    in scope between FM and CREM is that CREM has its focus on real estate as physical and economical assets utilized by an organisation, while FM has a wider service focus. The difference in scope between FM and CREM on one side and B2B marketing on the other is that FM and CREM are related to...... chapter provides important background information to understand the following chapters in this book. Research limitations: The chapter is mainly based on the experience and knowledge of the editors. It does not include original research but provides an introductory overview of the book. Originality...

  11. Family Background and Entrepreneurship

    DEFF Research Database (Denmark)

    Lindquist, Matthew J.; Sol, Joeri; Van Praag, Mirjam;

    Vast amounts of money are currently being spent on policies aimed at promoting entrepreneurship. The success of such policies, however, rests in part on the assumption that individuals are not ‘born entrepreneurs’. In this paper, we assess the importance of family background and neighborhood...... effects as determinants of entrepreneurship. We start by estimating sibling correlations in entrepreneurship. We find that between 20 and 50 percent of the variance in different entrepreneurial outcomes is explained by factors that siblings share. The average is 28 percent. Allowing for differential...... entrepreneurship does play a large role, as do shared genes....

  12. Color gradient background oriented schlieren imaging

    Science.gov (United States)

    Mier, Frank Austin; Hargather, Michael

    2015-11-01

    Background oriented schlieren (BOS) imaging is a method of visualizing refractive disturbances through the comparison of digital images. By comparing images with and without a refractive disturbance visualizations can be achieved via a range of image processing methods. Traditionally, backgrounds consist of random distributions of high contrast speckle patterns. To image a refractive disturbance, a digital image correlation algorithm is used to identify the location and magnitude of apparent pixel shifts in the background pattern. Here a novel method of using color gradient backgrounds is explored as an alternative. The gradient background eliminates the need to perform an image correlation between the two digital images, as simple image subtraction can be used to identify the location, magnitude, and direction of the image distortions. This allows for quicker processing. Two-dimensional gradient backgrounds using multiple colors are shown. The gradient backgrounds are demonstrated to provide quantitative data limited only by the camera's pixel resolution, whereas speckle backgrounds limit resolution to the size of the random pattern features and image correlation window size. Additional results include the use of a computer screen as a background.

  13. Educational Background in a Prison Population

    Science.gov (United States)

    Hetland, Hilde; Eikeland, Ole-Johan; Manger, Terje; Diseth, Age; Asbjornsen, Arve

    2007-01-01

    The aim of the present study was to explore the educational background of the total population of inmates in Norwegian prisons. The sample consisted of all 3 289 inmates over 18 years of age in Norwegian prisons. The response rate was 71.1 percent. Ninety four percent of the participants were men and mean age was 35 years. A questionnaire…

  14. The Backgrounds Data Center

    Science.gov (United States)

    Snyder, W. A.; Gursky, H.; Heckathorn, H. M.; Lucke, R. L.; Berg, S. L.; Dombrowski, E. G.; Kessel, R. A.

    1993-01-01

    The Strategic Defense Initiative Organization has created data centers for midcourse, plumes, and backgrounds phenomenologies. The Backgrounds Data Center (BDC) has been designated as the prime archive for data collected by SDIO programs. The BDC maintains a Summary Catalog that contains 'metadata,' that is, information about data, such as when the data were obtained, what the spectral range of the data is, and what region of the Earth or sky was observed. Queries to this catalog result in a listing of all data sets (from all experiments in the Summary Catalog) that satisfy the specified criteria. Thus, the user can identify different experiments that made similar observations and order them from the BDC for analysis. On-site users can use the Science Analysis Facility (SAFE for this purpose. For some programs, the BDC maintains a Program Catalog, which can classify data in as many ways as desired (rather than just by position, time, and spectral range as in the Summary Catalog). For example, data sets could be tagged with such diverse parameters as solar illumination angle, signal level, or the value of a particular spectral ratio, as long as these quantities can be read from the digital record or calculated from it by the ingest program. All unclassified catalogs and unclassified data will be remotely accessible.

  15. Holography for Schrodinger backgrounds

    CERN Document Server

    Guica, Monica; Taylor, Marika; van Rees, Balt

    2010-01-01

    We discuss holography for Schrodinger solutions of both topologically massive gravity in three dimensions and massive vector theories in (d+1) dimensions. In both cases the dual field theory can be viewed as a d-dimensional conformal field theory (two dimensional in the case of TMG) deformed by certain operators that respect the Schrodinger symmetry. These operators are irrelevant from the viewpoint of the relativistic conformal group but they are exactly marginal with respect to the non-relativistic conformal group. The spectrum of linear fluctuations around the background solutions corresponds to operators that are labeled by their scaling dimension and the lightcone momentum k_v. We set up the holographic dictionary and compute 2-point functions of these operators both holographically and in field theory using conformal perturbation theory and find agreement. The counterterms needed for holographic renormalization are non-local in the v lightcone direction.

  16. Exploration technology

    Energy Technology Data Exchange (ETDEWEB)

    Roennevik, H.C. [Saga Petroleum A/S, Forus (Norway)

    1996-12-31

    The paper evaluates exploration technology. Topics discussed are: Visions; the subsurface challenge; the creative tension; the exploration process; seismic; geology; organic geochemistry; seismic resolution; integration; drilling; value creation. 4 refs., 22 figs.

  17. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20101939 Bi Bingkun (No.1 Geological Surveying Party,Henan Bureau of Geology and Mineral Resources Exploration and Development,Luoyang 471023,China) Application of the Electric Method to Bauxite Exploration,Henan Province

  18. Genetical background of intelligence.

    Science.gov (United States)

    Junkiert-Czarnecka, Anna; Haus, Olga

    2016-01-01

    Intelligence as an ability to reason, think abstractly and adapt effectively to the environment is a subject of research in the field of psychology, neurobiology, and in the last twenty years genetics as well. Genetical testing of twins carried out from XX century indicated heritebility of intelligence, therefore confirmed an influence of genetic factor on cognitive processes. Studies on genetic background of intelligence focus on dopaminergic (DRD2, DRD4, COMT, SLC6A3, DAT1, CCKAR) and adrenergic system (ADRB2, CHRM2) genes as well as, neutrofins (BDNF) and oxidative stress genes (LTF, PRNP). Positive effect of investigated gene polymorphism was indicated by variation c.957C>T DRD2 gene (if in polymorphic site is thymine), polymorphism c.472G>A COMT gene (presence of adenine) and also gene ADRB2 c.46A->G (guanine), CHRM2 (thymine in place c.1890A>T) and BDNF (guanine in place c.472G>A) Obtained results indicate that intelligence is a feature dependent not only on genetic but also an environmental factor. PMID:27333929

  19. Biological aerosol background characterization

    Science.gov (United States)

    Blatny, Janet; Fountain, Augustus W., III

    2011-05-01

    To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.

  20. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  1. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site

  2. Semiclassical strings in Lunin-Maldacena background

    OpenAIRE

    Bobev, N. P.; Dimov, H.; Rashkov, R. C.

    2005-01-01

    In this paper we investigate semiclassical rotating string configurations in the recently found Lunin-Maldacena background. This background is conjectured to be dual to the Leigh-Strassler beta-deformation of N=4 SYM and therefore a good laboratory for tests of the AdS/CFT correspondence beyond the well explored AdS(5)x S(5) case. We consider different multispin configurations of rotating strings by allowing the strings to move in both the AdS(5) and the deformed S(5) part of the Lunin-Maldac...

  3. Pulsating Strings in Lunin-Maldacena Backgrounds

    OpenAIRE

    Giardino, Sergio; Rivelles, Victor

    2011-01-01

    We consider pulsating strings in Lunin-Maldacena backgrounds, specifically in deformed Minkowski spacetime and deformed AdS_5xS^5. We find the relation between the energy and the oscillation number of the pulsating string when the deformation is small. Since the oscillation number is an adiabatic invariant it can be used to explore the regime of highly excited string states. We then quantize the string and look for such a sector. For the deformed Minkowski background we find a precise match w...

  4. 媒介融合背景下的新闻传播人才培养定位探析--基于对媒介融合内涵的理解%Exploration on the Orientation of News Communication Talent Cultivation in the Background of Media Conver-gence:Based on the Understanding of the Connotation of Media Convergence

    Institute of Scientific and Technical Information of China (English)

    彭广林

    2015-01-01

    媒介融合是一个具有丰富内涵的新兴传播学概念。我们对其内涵的认识模糊是导致当前我国新闻传播人才定位不准的重要原因。因此,在媒介融合语境下,探析新闻传播人才定位必须从探究媒介融合的真实内涵着手。%Media convergence is a newly-emerging communica-tion concept with rich connotation. Our obscure knowledge of its connotation is an important reason causing the inaccurate orien-tation of news communication talent cultivation in China. There-fore, in the background of media convergence, this paper ana-lyzes that the orientation of news communication talents must start from the exploration of the real connotation of media conver-gence.

  5. JEM-X background models

    DEFF Research Database (Denmark)

    Huovelin, J.; Maisala, S.; Schultz, J.;

    2003-01-01

    revolution 41 of INTEGRAL. Total observing time used for the analysis was 216 502 s, with the average of 25 cps of background for each of the two JEM-X telescopes. JEM-X1 showed slightly higher average background intensity than JEM-X2. The detectors were stable during the long exposures, and weak orbital...... phase dependence in the background outside radiation belts was observed. The analysis yielded an average of 5 cps for the diffuse background, and 20 cps for the instrument background. The instrument background was found highly dependent on position, both for spectral shape and intensity. Diff use...... background was enhanced in the central area of a detector, and it decreased radially towards the edge, with a clear vignetting effect for both JEM-X units. The instrument background was weakest in the central area of a detector and showed a steep increase at the very edges of both JEM-X detectors, with...

  6. Supergravity backgrounds and symmetry superalgebras

    CERN Document Server

    Ertem, Ümit

    2016-01-01

    We consider the bosonic sectors of supergravity theories in ten and eleven dimensions which correspond to the low energy limits of string theories and M-theory. The solutions of supergravity field equations are known as supergravity backgrounds and the number of preserved supersymmetries in those backgrounds are determined by Killing spinors. We provide some examples of supergravity backgrounds which preserve different fractions of supersymmetry. An important invariant for the characterization of supergravity backgrounds is their Killing superalgebras which are constructed out of Killing vectors and Killing spinors of the background. After constructing Killing superalgebras of some special supergravity backgrounds, we discuss about the possibilities of the extensions of these superalgebras to include the higher degree hidden symmetries of the background.

  7. TRI Explorer

    Data.gov (United States)

    U.S. Environmental Protection Agency — TRI Explorer provides powerful, flexible, user-friendly access to Toxics Release Inventory (TRI) data to help communities identify facilities and chemical disposal...

  8. PROSPECTING EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20152148 Chen Qiang(No.106 Geological Party,Guizhou Bureau of Geology and Mineral Exploration and Development,Zunyi563009,China);Ye Deshu Discussion of Reasonable Exploratory Grid of Sedimentary Bauxite Deposit in Wuzhengdao Area of Guizhou

  9. EXPLORATION ENGINEERING

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090712 Ge Mingjun(General Institution of Mineral Exploration & Development in Qiqihaer of Heilongjiang Province,Qiqihaer 161006,China) Application of Emulsified Diesel Oil Drilling Fluid in Under-Balanced Drilling(Exploration Engineering(Rock & Soil Drilling and Tunneling),ISSN1672-7428,CN11-5063/TD,34(11),2007,p.43-45,1 illus.,2 tables,4 refs.)

  10. The Primordial Inflation Explorer

    Science.gov (United States)

    Kogut, Alan J.

    2012-01-01

    The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10(exp -3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

  11. Background subtraction theory and practice

    CERN Document Server

    Elgammal, Ahmed

    2014-01-01

    Background subtraction is a widely used concept for detection of moving objects in videos. In the last two decades there has been a lot of development in designing algorithms for background subtraction, as well as wide use of these algorithms in various important applications, such as visual surveillance, sports video analysis, motion capture, etc. Various statistical approaches have been proposed to model scene backgrounds. The concept of background subtraction also has been extended to detect objects from videos captured from moving cameras. This book reviews the concept and practice of back

  12. Farside explorer

    DEFF Research Database (Denmark)

    Mimoun, David; Wieczorek, Mark A.; Alkalai, Leon;

    2012-01-01

    the most radio-quiet region of near-Earth space, determine the internal structure and thermal evolution of the Moon, from crust to core, and quantify impact hazards in near-Earth space by the measurement of flashes generated by impact events. The Farside Explorer flight system includes two identical solar......Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of the Moon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded...... the primary differentiation and evolution of the Moon, it can be continuously monitored from the Earth-Moon L2 Lagrange point, and there is a complete lack of reflected solar illumination from the Earth. Farside Explorer will exploit these properties and make the first radio-astronomy measurements from...

  13. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091853 An Jinzhen(School of Earth and Space Sciences,Peking University,Beijing 100871,China);Zhou Pinggen Experiments on Exploring and Monitoring Landslip-Mass Using Geoelectric Resistivity Observations(Acta Seismologica Sinica,ISSN0253-3782,CN11-2021/P,30(3),2008,p.254-261,6 illus.,1 table,19 refs.)Key words:resistivity methods,landslidesIn the experiments,a high-density resistivity method is used to explore the electric structure of landslip mass,and a resistivity-changing anisotropy method is used to monitor the orientation and speed of main fracture extending of landslip mass.The results are as follows:1)the exploring experiments have verified a part of creep deformation borderline,the depth and thickness of groundwater horizon,and the property of super strata in the landslip mass investigated formerly,which have proved that the landslip belts contain rich groundwater

  14. PROSPECTING EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20112102 Chen Yiying(Shijiazhuang University of Economics,Shijiazhuang 050031,China);Li Wenbin Automatic Generation of Complicated Fault in Geological Section(Coal Geology & Exploration,ISSN1001-1986,CN61-1155/P,38(5),2010,p.7-12,8 illus.,13 refs.)Key words:faults,map compilation The researches of this paper are the basic theories and essential techniques of simulating complicated faults,and a series of approaches are proposed.Based on the practical geological exploration,data types are analyzed and database is normalized.The strata recovering technique is

  15. GEOCHEMICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150448Cen Kuang(State Key Laboratory of Geological Processes and Mineral Resources,School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China);Liu Xiuli The Application of the Aerosol Geochemical Exploration Method to the Jinwozi Gold Deposit(Geophysical and Geochemical Exploration,ISSN1000-8918,CN11-1906/P,38(1),2014,p.18-22,6illus.,12refs.)Key words:gold ores,geogas methods,Xinjiang The application of the aerosol theory and technology to deep prospecting is the basic problem discussed in this paper.The aerosol theory and technology were applied in the

  16. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    The determination of soil background is one of the most important activities supporting environmental restoration and waste management on the Hanford Site. Background compositions serve as the basis for identifying soil contamination, and also as a baseline in risk assessment processes used to determine soil cleanup and treatment levels. These uses of soil background require an understanding of the extent to which analytes of concern occur naturally in the soils. This report documents the results of sampling and analysis activities designed to characterize the composition of soil background at the Hanford Site, and to evaluate the feasibility for use as Sitewide background. The compositions of naturally occurring soils in the vadose Zone have been-determined for-nonradioactive inorganic and organic analytes and related physical properties. These results confirm that a Sitewide approach to the characterization of soil background is technically sound and is a viable alternative to the determination and use of numerous local or area backgrounds that yield inconsistent definitions of contamination. Sitewide soil background consists of several types of data and is appropriate for use in identifying contamination in all soils in the vadose zone on the Hanford Site. The natural concentrations of nearly every inorganic analyte extend to levels that exceed calculated health-based cleanup limits. The levels of most inorganic analytes, however, are well below these health-based limits. The highest measured background concentrations occur in three volumetrically minor soil types, the most important of which are topsoils adjacent to the Columbia River that are rich in organic carbon. No organic analyte levels above detection were found in any of the soil samples

  17. Background reduction in cryogenic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Daniel A.; /Fermilab

    2005-04-01

    This paper discusses the background reduction and rejection strategy of the Cryogenic Dark Matter Search (CDMS) experiment. Recent measurements of background levels from CDMS II at Soudan are presented, along with estimates for future improvements in sensitivity expected for a proposed SuperCDMS experiment at SNOLAB.

  18. Children of ethnic minority backgrounds

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    2010-01-01

    Children of ethnic minority background balance their everyday life between a cultural background rooted in their ethnic origin and a daily life in day care, schools and with peers that is founded in a majority culture. This means, among other things, that they often will have access to different ...

  19. Nonparametric Inference for the Cosmic Microwave Background

    CERN Document Server

    Genovese, C R; Nichol, R C; Arjunwadkar, M; Wasserman, L; Genovese, Christopher R.; Miller, Christopher J.; Nichol, Robert C.; Arjunwadkar, Mihir; Wasserman, Larry

    2004-01-01

    The Cosmic Microwave Background (CMB), which permeates the entire Universe, is the radiation left over from just 380,000 years after the Big Bang. On very large scales, the CMB radiation field is smooth and isotropic, but the existence of structure in the Universe - stars, galaxies, clusters of galaxies - suggests that the field should fluctuate on smaller scales. Recent observations, from the Cosmic Microwave Background Explorer to the Wilkinson Microwave Anisotropy Project, have strikingly confirmed this prediction. CMB fluctuations provide clues to the Universe's structure and composition shortly after the Big Bang that are critical for testing cosmological models. For example, CMB data can be used to determine what portion of the Universe is composed of ordinary matter versus the mysterious dark matter and dark energy. To this end, cosmologists usually summarize the fluctuations by the power spectrum, which gives the variance as a function of angular frequency. The spectrum's shape, and in particular the ...

  20. Cosmic Microwave Background Polarization and Inflation

    Science.gov (United States)

    Chuss, David T.

    2011-01-01

    Measurements of the cosmic microwave background (CMB) offer a means to explore the universe at a very early epoch. Specifically, if the universe went through a brief period of exponential expansion called inflation as current data suggest, gravitational waves from this period would polarize the CMB in a specific pattern. At GSFC, we are currently working towards two experiments that work in concert to measure this polarization pattern in search of evidence for inflation. The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization at frequencies between 40 and 150 GHz from the Atacama Desert in Chile. The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne experiment that will make similar measurements at frequencies between 200 and 600 GHz.

  1. EXPLORATION ENGINEERING

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131973 Luo Zhili(Chengdu University of Technology,Chengdu 610059,China);Sun Wei Reviews of the Exploration History of Stratigraphic Wells in the Sichuan Basin and Analysis of the Obtained Geological Effects(Natural Gas Industry,ISSN1000-0976,CN51-1179/TE,32(4),2012,p.9-12,1illus.,10)

  2. Exploring Television.

    Science.gov (United States)

    Kuhns, William

    "Exploring Television" is an inquiry/discovery textbook designed to help students to understand, analyze, criticize, evaluate, and judge the experiences they have had in front of the television set. The text consists of three main parts. "The Medium" inquires into the radio-movie origins of television and prompts research into the networks and…

  3. PROSPECTING EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090715 Chen Tao(Team 604,Geo-Exploration Bureau of Nonferrous Metals of Jilin Province,Huadian 132400,China);Zhao Tieying Present Utilizing Situation and Protective Planning of Mineral Resources in Huadian County,Jilin Province(Jilin Geology,ISSN1001-2427,CN22-1099/P,27(1),2008,p.96-100,4 refs.)

  4. EXPLORATION ENGINEERING

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20152094 Cai Xiaowen(No.145 Brigade,Gansu Bureau of Coal Geology,Zhangye734000,China);Chen Xiqing Performance Evaluation and Field Application of GFT AntiCollapse and Drag Reduction Agent(Exploration Engineering,ISSN1672-7428,CN11-

  5. Exploring quadrangulations

    KAUST Repository

    Peng, Chihan

    2014-01-01

    Here we presented a framework to explore quad mesh topologies. The core of our work is a systematic enumeration algorithm that can generate all possible quadrangular meshes inside a defined boundary with an upper limit of v3-v5 pairs. The algorithm is orders of magnitude more efficient than previous work. The combination of topological enumeration and shape-space exploration demonstrates that mesh topology has a powerful influence on geometry. The Fig. 18. A gallery of different quadrilateral meshes for a Shuriken. The quadrilaterals of the model were colored in a postprocess. Topological variations have distinctive, interesting patterns of mesh lines. © 2014 ACM 0730-0301/2014/01-ART3 15.00.

  6. Generalized Background-Field Method

    CERN Document Server

    Feng, Y J

    1997-01-01

    The graphical method discussed previously can be used to create new gauges not reachable by the path-integral formalism. By this means a new gauge is designed for more efficient two-loop QCD calculations. It is related to but simpler than the ordinary background-field gauge, in that even the triple-gluon vertices for internal lines contain only four terms, not the usual six. This reduction simplifies the calculation inspite of the necessity to include other vertices for compensation. Like the ordinary background-field gauge, this generalized background-field gauge also preserves gauge invariance of the external particles. As a check of the result and an illustration for the reduction in labour, an explicit calculation of the two-loop QCD 45% of computation compared to the ordinary background-field gauge.

  7. The Cosmic Background Radiation, 1997

    CERN Document Server

    Smoot, G F; Smoot, George; Scott, Douglas

    1997-01-01

    We summarise the current status of cosmic microwave background spectrum and anisotropy measurements, and their theoretical interpretation. This is the update of the mini-review for the 1997 web-version of the Review of Particle Properties.

  8. Geometrodynamics on a background spacetime

    CERN Document Server

    Papadopoulos, P P; Papadopoulos, Philippos; Sopuerta, Carlos F.

    2001-01-01

    The formulation of the initial value problem for the Einstein equations is at the heart of obtaining interesting new solutions using numerical relativity and still very much under theoretical and applied scrutiny. We develop a specialised background geometry approach, for systems where there is non-trivial a priori knowledge about the spacetime under study. The background three-geometry and associated connection are used to express the ADM evolution equations in terms of physical non-linear deviations from that background. Expressing the equations in first order form leads naturally to a system closely linked to the Einstein-Christoffel system, introduced by Anderson and York, and sharing its hyperbolicity properties. The background metric approach can drastically alter the source structure of the equations, and we present an argument as to why this is likely to be numerically advantageous.

  9. QED_2 in Curved Backgrounds

    OpenAIRE

    Ghosh, Amit

    1996-01-01

    Here we discuss the two dimensional quantum electrodynamics in curved space-time, especially in the background of some black holes. We first show the existence of some new quantum mechanical solution which has interesting properties. Then for some special black holes we discuss the fermion-black hole scattering problem. The issue of confinement is intimately connected with these solutions and we also comment on this in this background. Finally, the entanglement entropy and the Hawking radiati...

  10. Backgrounds in AFP Detector Estimation

    CERN Document Server

    Huang, Yicong

    2016-01-01

    The ATLAS Forward Proton (AFP) detectors aim to measure protons that are scattered in the ATLAS interaction point under very small angles ($90-160 \\mu rad$). The diffractive protons detected by the AFP may be accompanied by beam halo. This report presents an estimation of the beam halo backgrounds in the AFP using low pile-up data, and position distributions of the backgrounds in the AFP.

  11. The Supernova Relic Neutrino Background

    OpenAIRE

    Kaplinghat, M.; Steigman, G.; Walker, T. P.

    1999-01-01

    An upper bound to the supernova relic neutrino background from all past Type II supernovae is obtained using observations of the Universal metal enrichment history. We show that an unambiguous detection of these relic neutrinos by the Super-Kamiokande detector is unlikely. We also analyze the event rate in the Sudbury Neutrino Observatory (where coincident neutrons from anti-nu_e + D --> n + n + e+ might enhance background rejection), and arrive at the same conclusion. If the relic neutrino f...

  12. Dark matter, hot and cold

    International Nuclear Information System (INIS)

    Cosmologists responded enthusiastically to the announcement at the Washington meeting of the American Physical Society in April 1992 that the Cosmic Background Explorer (COBE) had succeeded in detecting primordial anisotropies in the cosmic microwave background radiation (CMB - June 1992, page 1). The COBE satellite was launched in November 1989 into an orbit approximately 900 km above the Earth, carrying instruments to make precise measurements of the spectrum and anisotropy of the CMB. Data from the Far-lnfra Red Absolute Spectrophotometer (FIRAS) beautifully shows the CMB spectrum to be that of a black body at a temperature of 2.73±0.06K. An even more important result, at least from the viewpoint of theories of large scale structure formation (LSS), comes from the Differential Microwave Radiometer (DMR) which provided the first evidence for CMB anisotropy. Some anisotropy on the angular slice probed by COBE is expected in any reasonable model of LSS. COBE's measurement of the quadrupole anisotropy at six parts per million provides an important clue for developing a 'standard model' of LSS. The COBE numbers are in remarkably good agreement with the predictions of a particularly simple class of LSS models proposed almost a decade ago, with far reaching implications for dark matter searches

  13. Improvements to background level of the low background HPGe setup

    International Nuclear Information System (INIS)

    A low background HPGe counting setup has been installed at TIFR. The detector, shielded with low activity Pb and Cu shield, has been extensively used for material screening for the TIN. TIN detector (The INdia-based TIN detector). It is proposed to use this setup for the search of rare decay processes like double beta decay (DBD) to the excited states of the daughter nuclei where T1/2 > 1018 years. To enhance the sensitivity of measurement, the background levels of the detector has been further improved by an addition of an active cosmic muon veto system in the FPGA based DAQ system

  14. Virtual exploration

    Energy Technology Data Exchange (ETDEWEB)

    Milwood-Hargrave, M.; Francis, A.M. (Ikon Geoscience, Twickenham, Middlesex (United Kingdom))

    1993-09-01

    With the now commonplace implementation of interactive interpretation workstations, the process of generating a time model for a prospect has been simplified and accelerated. This paper shows that for many structural traps, the critical interpretation steps are in subsequently generating a valid depth model, evaluating the depth structure, and being able to realistically assess confidence limits of the model. The development of a comprehensive velocity model is a key element of any depth conversion. Lateral velocity variations across an area are capable of generating structures where the time interpretation is flat. An example is shown in this paper, and the effect of altering the velocity field and the resulting changes to the structure are described. Forward and inverse modeling are used to show that the structure is more favorable than was first expected from the depth conversion. From this example, the idea of sensitivity testing of a number of simple structures is developed. A fully interactive ray trace modeling system integrated with an interpretation workstation allows different confidence limits to be rapidly tested and evaluated. By extending the model into the third dimension, specific scenarios can be constructed in three-dimension (3-D) and uncertainty limits tested on a complete reservoir. Further than this, the construction of type models in 3-D allows the concept of [open quotes]virtual exploration[close quotes] to be realized, whereby specific exploration concepts can be investigated and tested. The virtual exploration model, and its associated seismic data set, form an ideal educational, planning, and training tool for all levels of geophysicists and geologists.

  15. Space exploration

    CERN Document Server

    90, Sol

    2008-01-01

    Space Exploration, is one book in the Britannica Illustrated Science Library Series that is correlated to the science curriculum in grades 5-8. The Britannica Illustrated Science Library is a visually compelling set that covers earth science, life science, and physical science in 16 volumes.  Created for ages 10 and up, each volume provides an overview on a subject and thoroughly explains it through detailed and powerful graphics-more than 1,000 per volume-that turn complex subjects into information that students can grasp.  Each volume contains a glossary with full definitions for vocabulary

  16. Semiclassical strings in Lunin-Maldacena background

    International Nuclear Information System (INIS)

    The aim of this paper is to investigate semiclassical rotating string configurations in the recently found Lunin-Maldacena background. This background is conjectured to be dual to the Leigh-Strassler β-deformation of N = 4 SYM and therefore a good laboratory for tests of the AdS/CFT correspondence beyond the well explored AdS5xS5 case. We consider different multispin configurations of rotating strings by allowing the strings to move in both the AdS5 and the deformed S5 part of the Lunin-Maldacena background. For all of these configurations we compute the string energy in terms of the angular momenta and the string winding numbers and thus provide the possibility of reproducing our results from a computation of the anomalous dimension of the corresponding dilatation operator. This can be achieved by means of the Bethe Ansatz techniques for the relevant sectors of the corresponding Yang-Mills theory. We also compare our results with those for multispin rotating strings on AdS5xS5. (authors)

  17. Nobel Lecture: From the Big Bang to the Nobel Prize and beyond

    Science.gov (United States)

    Mather, John C.

    NASA’s Cosmic Background Explorer satellite mission, the COBE, laid the foundations for modern cosmology by measuring the spectrum and anisotropy of the cosmic microwave background radiation and discovering the cosmic infrared background radiation. I describe the history of the COBE project, its scientific context, the people who built it, and the scientific results. The COBE observed the universe on the largest scales possible by mapping the cosmic microwave and infrared background radiation fields and determining their spectra. It produced conclusive evidence that the hot Big Bang theory of the early universe is correct, showed that the early universe was very uniform but not perfectly so, and that the total luminosity of post Big Bang objects is twice as great as previously believed. The COBE concept was developed by a Mission Definition Study Team appointed by NASA in 1976, based on three competing proposals submitted in 1974. The COBE was built in-house by Goddard Space Flight Center, with a helium cryostat provided by Ball Aerospace, and was launched on a Delta rocket built by McDonnell Douglas. It is in a circular orbit 900km above the Earth, in a plane inclined 99° to the equator and roughly perpendicular to the line to the Sun. It carried three instruments, a far infrared absolute spectrophotometer (FIRAS), a differential microwave radiometer with three channels (DMR), and a diffuse infrared background experiment (DIRBE). The helium cryostat cooled the FIRAS and DIRBE for 10months until the helium was exhausted, but operations continued for a total of 4years . Subsequent observations have confirmed the COBE results and led to measurements of the main cosmological parameters with a precision of a few percent.

  18. A definition of background independence

    International Nuclear Information System (INIS)

    We propose a definition for background (in)/dependence in dynamical theories of the evolution of configurations that have a continuous symmetry and test this definition on particle models and on gravity. Our definition draws from Barbour's best matching framework developed for the purpose of implementing spatial and temporal relationalism. Among other interesting theories, general relativity can be derived within this framework in novel ways. We study the detailed canonical structure of a wide range of best matching theories and show that their actions must have a local gauge symmetry. When gauge theory is derived in this way, we obtain at the same time a conceptual framework for distinguishing between background-dependent and -independent theories. Gauge invariant observables satisfying Kuchar's criterion are identified and, in simple cases, explicitly computed. We propose a procedure for inserting a global background time into temporally relational theories. Interestingly, using this procedure in general relativity leads to unimodular gravity.

  19. The isotropic radio background revisited

    CERN Document Server

    Fornengo, Nicolao; Regis, Marco; Taoso, Marco

    2014-01-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emi...

  20. Neutron background estimates in GESA

    Directory of Open Access Journals (Sweden)

    Fernandes A.C.

    2014-01-01

    Full Text Available The SIMPLE project looks for nuclear recoil events generated by rare dark matter scattering interactions. Nuclear recoils are also produced by more prevalent cosmogenic neutron interactions. While the rock overburden shields against (μ,n neutrons to below 10−8 cm−2 s−1, it itself contributes via radio-impurities. Additional shielding of these is similar, both suppressing and contributing neutrons. We report on the Monte Carlo (MCNP estimation of the on-detector neutron backgrounds for the SIMPLE experiment located in the GESA facility of the Laboratoire Souterrain à Bas Bruit, and its use in defining additional shielding for measurements which have led to a reduction in the extrinsic neutron background to ∼ 5 × 10−3 evts/kgd. The calculated event rate induced by the neutron background is ∼ 0,3 evts/kgd, with a dominant contribution from the detector container.

  1. Generative electronic background music system

    Energy Technology Data Exchange (ETDEWEB)

    Mazurowski, Lukasz [Faculty of Computer Science, West Pomeranian University of Technology in Szczecin, Zolnierska Street 49, Szczecin, PL (Poland)

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  2. Detector Background at Muon Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2011-09-01

    Physics goals of a Muon Collider (MC) can only be reached with appropriate design of the ring, interaction region (IR), high-field superconducting magnets, machine-detector interface (MDI) and detector. Results of the most recent realistic simulation studies are presented for a 1.5-TeV MC. It is shown that appropriately designed IR and MDI with sophisticated shielding in the detector have a potential to substantially suppress the background rates in the MC detector. The main characteristics of backgrounds are studied.

  3. Background music and cognitive performance.

    Science.gov (United States)

    Angel, Leslie A; Polzella, Donald J; Elvers, Greg C

    2010-06-01

    The present experiment employed standardized test batteries to assess the effects of fast-tempo music on cognitive performance among 56 male and female university students. A linguistic processing task and a spatial processing task were selected from the Criterion Task Set developed to assess verbal and nonverbal performance. Ten excerpts from Mozart's music matched for tempo were selected. Background music increased the speed of spatial processing and the accuracy of linguistic processing. The findings suggest that background music can have predictable effects on cognitive performance. PMID:20865993

  4. Exotic branes and nongeometric backgrounds.

    Science.gov (United States)

    de Boer, Jan; Shigemori, Masaki

    2010-06-25

    When string or M theory is compactified to lower dimensions, the U-duality symmetry predicts so-called exotic branes whose higher-dimensional origin cannot be explained by the standard string or M-theory branes. We argue that exotic branes can be understood in higher dimensions as nongeometric backgrounds or U folds, and that they are important for the physics of systems which originally contain no exotic charges, since the supertube effect generically produces such exotic charges. We discuss the implications of exotic backgrounds for black hole microstate (non-)geometries. PMID:20867363

  5. Generative electronic background music system

    International Nuclear Information System (INIS)

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions

  6. Exploring rationality in schizophrenia

    DEFF Research Database (Denmark)

    Revsbech, Rasmus; Mortensen, Erik Lykke; Owen, Gareth;

    2015-01-01

    Background Empirical studies of rationality (syllogisms) in patients with schizophrenia have obtained different results. One study found that patients reason more logically if the syllogism is presented through an unusual content. Aims To explore syllogism-based rationality in schizophrenia. Method...... Thirty-eight first-admitted patients with schizophrenia and 38 healthy controls solved 29 syllogisms that varied in presentation content (ordinary v. unusual) and validity (valid v. invalid). Statistical tests were made of unadjusted and adjusted group differences in models adjusting for intelligence and...... differences became non-significant. Conclusions When taking intelligence and neuropsychological performance into account, patients with schizophrenia and controls perform similarly on syllogism tests of rationality....

  7. Geoelectrical exploration

    Science.gov (United States)

    Barseem, Mostafa Said; El Lateef, Talaat Ali Abd; Ezz El Deen, Hosny Mahomud; Abdel Rahman, Abd Allah Al Abaseiry

    2015-12-01

    Sinai development is a goal of successive governments in Egypt. The present study is a geoelectrical exploration to find appropriate solutions of the problems affecting the land of a Research Station in Southeast Al Qantara. This research station is one of the Desert Research Center stations to facilitate the development of desert land for agriculture by introducing applied research. It suffers from some problems which can be summarized in the shortage of irrigation water and water logging. The appropriate solutions of these problems have been delineated by the results of 1D and 2D geoelectrical measurements. Electrical resistivity (ER) revealed the subsurface sedimentary sequences and extension of subsurface layers in the horizontal and vertical directions, especially, the water bearing layer. Additionally it helped to choose the most suitable places to drill productive wells with a good condition.

  8. EXPLORATION ENGINEERING

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111381 Geng Tao(Xi’an Center of Geological Survey of CGS,Xi’an 710054,China);Liu Kuanhou Application of Accurate Inspection of CQG2000 Quasi-Geoid Model to Regional Gravity Survey in Qinghai-Tibetan Plateau(Northwestern Geology,ISSN1009-6248,CN61-1149/P,43(2),2010,p.1-7,1 illus.,2 tables,4 refs.)Key words:gravity exploration,Global Positioning System,Qinghai-Tibetan Plateau During regional gravity survey,accuracy of orthometric height may affect the accuracy of gravity survey directly.The field test in Qinghai-Tibetan Plateau show that the accuracy of CQG2000 quasi-geoid model can satisfy the accuracy of orthometric height during the 1∶200 000 regional gravity survey.Based on the test,the authors summarize the method how the accuracy of height measurement

  9. Low Background Micromegas in CAST

    CERN Document Server

    Garza, J G; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.

    2015-01-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

  10. Low Background Micromegas in CAST

    DEFF Research Database (Denmark)

    Garza, J G; Aune, S.; Aznar, F.;

    2014-01-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micr...

  11. Low background techniques in CANDLES

    International Nuclear Information System (INIS)

    CANDLES is a double beta decay experiment using 48Ca in CaF2 crystals. The measurement is being performed with prototype detector (CANDLES III) for high sensitive measurement in the future. Recent status of detector improvements and background reduction techniques are described in this paper

  12. Interaction of Working Memory, Compressor Speed and Background Noise Characteristics

    OpenAIRE

    Ohlenforst, Barbara; MacDonald, Ewen; Souza, Pamela

    2014-01-01

    Previous studies have shown that individuals with poor working memory perform worse in speech recognition tests when fast compression release time is applied. However, it is not clear why this effect occurs only when modulations are present in the background noise. This study explored the relationship between working memory capacity, compression release time and characteristics of the background noise. This relationship is important to understand because the majority of everyday listening sit...

  13. The SCUBA-2 Cosmology Legacy Survey: blank-field number counts of 450um-selected galaxies and their contribution to the cosmic infrared background

    CERN Document Server

    Geach, J E; Coppin, K E K; Dunlop, J S; Halpern, M; Smail, Ian; van der Werf, P; Serjeant, S; Farrah, D; Roseboom, I; Targett, T; Arumugam, V; Asboth, V; Blain, A; Chrysostomou, A; Clarke, C; Ivison, R J; Jones, S L; Karim, A; Mackenzie, T; Meijerink, R; Michalowski, M J; Scott, D; Simpson, J; Swinbank, A M; Alexander, D; Almaini, O; Aretxaga, I; Best, P; Chapman, S; Clements, D L; Conselice, C; Danielson, A L R; Eales, S; Edge, A C; Gibb, A; Hughes, D; Jenness, T; Knudsen, K K; Lacey, C; Marsden, G; McMahon, R; Oliver, S; Page, M J; Peacock, J A; Rigopoulou, D; Robson, E I; Spaans, M; Stevens, J; Webb, T M A; Willott, C; Wilson, C D; Zemcov, M

    2012-01-01

    The first deep blank-field 450um map (1-sigma~1.3mJy) from the SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with the James Clerk Maxwell Telescope (JCMT) is presented. Our map covers 140 arcmin^2 of the COSMOS field, in the footprint of the HST CANDELS area. Using 60 submillimetre galaxies (SMGs) detected at >3.75-sigma, we evaluate the number counts of 450um-selected galaxies with flux densities S_450>5mJy. The 8-arcsec JCMT beam and high sensitivity of SCUBA-2 now make it possible to directly resolve a larger fraction of the cosmic infrared background (CIB, peaking at ~200um) into the individual galaxies responsible for its emission than has previously been possible at this wavelength. At S_450>5mJy we resolve (7.4[+/-]0.7)x10^-2 MJy/sr of the CIB at 450um (equivalent to 16[+/-]7% of the absolute brightness measured by COBE at this wavelength) into point sources. A further ~40% of the CIB can be recovered through a statistical stack of 24um emitters in this field, indicating that the majority (~60%) o...

  14. [Exploring Aeronautics

    Science.gov (United States)

    Robinson, Brandi

    2004-01-01

    This summer I have been working with the N.A.S.A. Project at Cuyahoga Community College (Tri-C) under the title of Exploring Aeronautics Project Leader. The class that I have worked with is comprised of students that will enter the eighth grade in the fall of 2004. The program primarily focuses upon math proficiency and individualized class projects. My duties have encompassed both realms. During the first 2-3 weeks of my internship, I worked at NASA Glenn Research Center (GRC) researching, organizing, and compiling information for weekly Scholastic Challenges and the Super Scholastic Challenge. I was able to complete an overview of Scholastic Challenge and staff responsibilities regarding the competition; a proposal for an interactive learning system, Quizdom; a schedule for challenge equipment, as well as a schedule listing submission deadlines for the staff. Also included in my tasks, during these first 2-3 weeks, were assisting Tammy Allen and Candice Thomas with the student application review and interview processes for student applicants. For the student and parent orientation, I was assigned publications and other varying tasks to complete before the start of the program. Upon the commencement of the program, I changed location from NASA GRC to Tri-C Metro Campus, where student classes for the Cleveland site are held. During the duration of the program, I work with the instructor for the Exploring Aeronautics class, kkkk, assisting in classroom management, daily attendance, curriculum, project building, and other tasks as needed. These tasks include the conducting of the weekly competition, known as Scholastic Challenge. As a Project Leader, I am also responsible for one subject area of the Scholastic Challenge aspect of the N.A.S.A. Project curriculum. Each week I have to prepare a mission that the participants will take home the following Monday and at least 10 questions that will be included in the pool of questions used for the Scholastic Challenge

  15. The Diffuse Supernova Neutrino Background

    CERN Document Server

    Beacom, John F

    2010-01-01

    The Diffuse Supernova Neutrino Background (DSNB) is the weak glow of MeV neutrinos and antineutrinos from distant core-collapse supernovae. The DSNB has not been detected yet, but the Super-Kamiokande (SK) 2003 upper limit on the electron antineutrino flux is close to predictions, now quite precise, based on astrophysical data. If SK is modified with dissolved gadolinium to reduce detector backgrounds and increase the energy range for analysis, then it should detect the DSNB at a rate of a few events per year, providing a new probe of supernova neutrino emission and the cosmic core-collapse rate. If the DSNB is not detected, then new physics will be required. Neutrino astronomy, while uniquely powerful, has proven extremely difficult -- only the Sun and the nearby Supernova 1987A have been detected to date -- so the promise of detecting new sources soon is exciting indeed.

  16. Background paper on aquaculture research

    OpenAIRE

    Wenblad, Axel; Jokumsen, Alfred; Eskelinen, Unto; Torrissen, Ole

    2013-01-01

    The Board of MISTRA established in 2012 a Working Group (WG) on Aquaculture to provide the Board with background information for its upcoming decision on whether the foundation should invest in aquaculture research. The WG included Senior Advisor Axel Wenblad, Sweden (Chairman), Professor Ole Torrissen, Norway, Senior Advisory Scientist Unto Eskelinen, Finland and Senior Advisory Scientist Alfred Jokumsen, Denmark. The WG performed an investigation of the Swedish aquaculture sector including ...

  17. Background radioactivity in environmental materials

    International Nuclear Information System (INIS)

    This paper presents the results of a literature search to identify information on concentrations of 'background' radioactivity in foodstuffs and other commonly available environmental materials. The review has concentrated on naturally occurring radioactivity in foods and on UK data, although results from other countries have also been considered where appropriate. The data are compared with established definitions of a 'radioactive' substance and radionuclides which do not appear to be adequately covered in the literature are noted. (author)

  18. Cosmic Microwave Background Acoustic Peak Locations

    CERN Document Server

    Pan, Zhen; Mulroe, Brigid; Narimani, Ali

    2016-01-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and twelve extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g., that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 degrees out of phase. However, there are large differences in expectations for extrema locations from simple analytic models vs. numerical calculations. Here we quantitatively explore the origin of these differences in gravitational potential tr...

  19. Stochastic background of gravitational waves

    CERN Document Server

    D'Araújo, J C N; Aguiar, O D

    2000-01-01

    A continuous stochastic background of gravitational waves (GWs) for burst sources is produced if the mean time interval between the occurrence of bursts is smaller than the average time duration of a single burst at the emission, i.e., the so called duty cycle must be greater than one. To evaluate the background of GWs produced by an ensemble of sources, during their formation, for example, one needs to know the average energy flux emitted during the formation of a single object and the formation rate of such objects as well. In many cases the energy flux emitted during an event of production of GWs is not known in detail, only characteristic values for the dimensionless amplitude and frequencies are known. Here we present a shortcut to calculate stochastic backgrounds of GWs produced from cosmological sources. For this approach it is not necessary to know in detail the energy flux emitted at each frequency. Knowing the characteristic values for the ``lumped'' dimensionless amplitude and frequency we show tha...

  20. Background independence in a background dependent renormalization group

    Science.gov (United States)

    Labus, Peter; Morris, Tim R.; Slade, Zöe H.

    2016-07-01

    Within the derivative expansion of conformally reduced gravity, the modified split Ward identities are shown to be compatible with the flow equations if and only if either the anomalous dimension vanishes or the cutoff profile is chosen to have a power-law form. No solutions exist if the Ward identities are incompatible. In the compatible case, a clear reason is found for why Ward identities can still forbid the existence of fixed points; however, for any cutoff profile, a background independent (and parametrization independent) flow equation is uncovered. Finally, expanding in vertices, the combined equations are shown generically to become either overconstrained or highly redundant beyond the six-point level.

  1. Background independence in a background dependent renormalization group

    CERN Document Server

    Labus, Peter; Slade, Zoë H

    2016-01-01

    Within the derivative expansion of conformally reduced gravity, the modified split Ward identities are shown to be compatible with the flow equations if and only if either the anomalous dimension vanishes or the cutoff profile is chosen to be power law. No solutions exist if the Ward identities are incompatible. In the compatible case, a clear reason is found for why Ward identities can still forbid the existence of fixed points; however, for any cutoff profile, a background independent (and parametrisation independent) flow equation is uncovered. Finally, expanding in vertices, the combined equations are shown generically to become either over-constrained or highly redundant beyond the six-point level.

  2. Exploring Water Pollution. Part II

    Science.gov (United States)

    Rillo, Thomas J.

    1975-01-01

    This is part two of a three part article related to the science activity of exploring environmental problems. Part one dealt with background information for the classroom teacher. Presented here is a suggested lesson plan on water pollution. Objectives, important concepts and instructional procedures are suggested. (EB)

  3. Exploring Mars

    Science.gov (United States)

    Breuil, Stéphanie

    2016-04-01

    Mars is our neighbour planet and has always fascinated humans as it has been seen as a potential abode for life. Knowledge about Mars is huge and was constructed step by step through numerous missions. It could be difficult to describe these missions, the associated technology, the results, the questions they raise, that's why an activity is proposed, that directly interests students. Their production is presented in the poster. Step 1: The main Mars feature and the first Mars explorations using telescope are presented to students. It should be really interesting to present "Mars Canals" from Percival Lowell as it should also warn students against flawed interpretation. Moreover, this study has raised the big question about extra-terrestrial life on Mars for the first time. Using Google Mars is then a good way to show the huge knowledge we have on the planet and to introduce modern missions. Step 2: Students have to choose and describe one of the Mars mission from ESA and NASA. They should work in pairs. Web sites from ESA and NASA are available and the teacher makes sure the main missions will be studied. Step 3: Students have to collect different pieces of information about the mission - When? Which technology? What were the main results? What type of questions does it raise? They prepare an oral presentation in the form they want (role play, academic presentation, using a poster, PowerPoint). They also have to produce playing cards about the mission that could be put on a timeline. Step 4: As a conclusion, the different cards concerning different missions are mixed. Groups of students receive cards and they have to put them on a timeline as fast as possible. It is also possible to play the game "timeline".

  4. Family background of elementary music school pupils

    Directory of Open Access Journals (Sweden)

    Bogunović Blanka D.

    2005-01-01

    Full Text Available The theoretical concept of the research relies on the assumption of high-quality and supportive family background of elementary music school pupils as a basis for their musical development and success in different forms of musical activity. The aim of the research is a description on the social-demographical profile and relevant characteristics of their family background before and during early musical education. The sample comprises 506 fathers and 512 mothers whose children attend five different elementary music school. The method is explorative and deals with a sphere that has not been researched in this manner in our society to date. The results point to the existence of a typical musically encouraging and stimulating environment and continuous presence of various forms of family encouragement, support and musical stimulation. Trans-cultural family model of a music student is defined. The structure of family indictors leads to the conclusion about the definite existence of constant parental involvement during pre-school and early school period, as well as parental joint and separate actions which are complemented at different ages of the children, in different areas of actions and in different activity patterns. A practical contribution of the research is to help understanding the importance of parental role in gifted children’s musical development and progress and consequently the need for the establishment of cooperation between music schools and parents.

  5. The large-scale polarization of the microwave background and foreground

    OpenAIRE

    de Oliveira-Costa, Angelica; Tegmark, Max; O'Dell, Chris; Keating, Brian; Timbie, Peter; Efstathiou, George; Smoot, George

    2002-01-01

    The DASI discovery of CMB polarization has opened a new chapter in cosmology. Most of the useful information about inflationary gravitational waves and reionization is on large angular scales where Galactic foreground contamination is the worst, so a key challenge is to model, quantify and remove polarized foregrounds. We use the POLAR experiment, COBE/DMR and radio surveys to provide the strongest limits to date on the TE cross power spectrum of the CMB on large angular scales and to quantif...

  6. Cosmological Perturbations of Quantum-Mechanical Origin and Anisotropy of the Microwave Background

    CERN Document Server

    Grishchuk, L P

    1993-01-01

    Cosmological perturbations generated quantum-mechanically (as a particular case, during inflation) possess statistical properties of squeezed quantum states. The power spectra of the perturbations are modulated and the angular distribution of the produced temperature fluctuations of the CMBR is quite specific. An exact formula is derived for the angular correlation function of the temperature fluctuations caused by squeezed gravitational waves. The predicted angular pattern can, in principle, be revealed by the COBE-type observations.

  7. [Toothache with a neuropathic background].

    Science.gov (United States)

    Khatchaturian, V; de Wijer, A; Kalaykova, S I; Steenks, M H

    2015-03-01

    A 48-year old woman in good general health was referred to the orofacial pain clinic in a centre for special dentistry with a toothache in the premolar region of the left maxillary quadrant. The complaints had existed for 15 years and various dental treatments, including endodontic treatments, apical surgery, extraction and splint therapy, had not helped to alleviate the complaints. As a result of the fact that anti-epileptic drugs were able to reduce the pain it was concluded that this 'toothache' satisfied the criteria of an atypical odontalgia: 'toothache' with a neuropathic background. PMID:26181392

  8. Breast cancer - background and overview

    International Nuclear Information System (INIS)

    This summary is to provide the reader with a brief overview of the key concepts relating to epidemiology and etiology; clinical presentation and patterns of spread; Canadian guidelines for management; prognosis; and current Canadian screening recommendations in the diagnosis and treatment of breast cancer. This information will enable the reader to have the appropriate background knowledge before delving into the subsequent articles in this special CJMRT breast cancer edition. A variety of references have been provided for readers who are interested in more than a skeleton version of the current literature. (author)

  9. Interaction of Working Memory, Compressor Speed and Background Noise Characteristics

    DEFF Research Database (Denmark)

    Ohlenforst, Barbara; MacDonald, Ewen; Souza, Pamela

    Previous studies have shown that individuals with poor working memory perform worse in speech recognition tests when fast compression release time is applied. However, it is not clear why this effect occurs only when modulations are present in the background noise. This study explored the relatio...

  10. Experiences of School Belonging for Young Children with Refugee Backgrounds

    Science.gov (United States)

    Due, Clemence; Riggs, Damien W.; Augoustinos, Martha

    2016-01-01

    Previous research with adolescents with refugee backgrounds living in countries of resettlement has found that school belonging has an impact on a range of well-being and developmental outcomes, including mental health, peer relationships, self-esteem and self-efficacy, and academic achievement. However, very little research has explored school…

  11. Immunopathogenic Background of Pars Planitis.

    Science.gov (United States)

    Przeździecka-Dołyk, Joanna; Węgrzyn, Agnieszka; Turno-Kręcicka, Anna; Misiuk-Hojło, Marta

    2016-04-01

    Pars planitis is defined as an intermediate uveitis of unknown background of systemic disease with characteristic formations such as vitreous snowballs, snowbanks and changes in peripheral retina. The incidence of pars planitis varies 2.4-15.4 % of the uveitis patients. The pathogenesis of the disease is to be determined in future. Clinical and histopathological findings suggest an autoimmune etiology, most likely as a reaction to endogenous antigen of unknown source, with T cells predominant in both vitreous and pars plana infiltrations. T cells subsets play an important role as a memory-effector peripheral cell. Snowbanks are formed as an effect of post inflammatory glial proliferation of fibrous astrocytes. There is also a genetic predisposition for pars planitis by human leukocyte antigen and several other genes. A coexistence of multiple sclerosis and optic neuritis has been described in numerous studies. Epiretinal membrane, cataract, cystoid macular edema, retinal detachment, retinal vasculitis, neovascularization, vitreous peripheral traction, peripheral hole formation, vitreous hemorrhage, disc edema are common complications observed in pars planitis. There is a need to expand the knowledge of the pathogenic and immunologic background of the pars planitis to create an accurate pharmacological treatment. PMID:26438050

  12. Cosmic background radiation: a hagiography

    Energy Technology Data Exchange (ETDEWEB)

    Abramo, Luis Raul [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica

    2009-07-01

    Full text. Cosmology advanced tremendously since Gamow and his students predicted the cosmic microwave background radiation, and since Penzias and Wilson observed it for the first time. The observations of the CMBR point to a Universe which is beautiful in its simplicity: the amazing richness of structures can be explained by a minimalistic set of well-known physical laws, a reasonable amount of free parameters, and 'natural' initial conditions which realize the idea of maximum entropy. We will revise the latest observations and show how the CMBR is presently allowing the study of the 'fine structure' of cosmological phenomena. We will also discuss the possibility of a detection of rotational modes (B-modes) in the polarization of the CMBR, that may reveal which processes (inflation ?) acted in the very early universe to endow it with these beautiful and simple properties. (author)

  13. Cosmic background radiation: a hagiography

    International Nuclear Information System (INIS)

    Full text. Cosmology advanced tremendously since Gamow and his students predicted the cosmic microwave background radiation, and since Penzias and Wilson observed it for the first time. The observations of the CMBR point to a Universe which is beautiful in its simplicity: the amazing richness of structures can be explained by a minimalistic set of well-known physical laws, a reasonable amount of free parameters, and 'natural' initial conditions which realize the idea of maximum entropy. We will revise the latest observations and show how the CMBR is presently allowing the study of the 'fine structure' of cosmological phenomena. We will also discuss the possibility of a detection of rotational modes (B-modes) in the polarization of the CMBR, that may reveal which processes (inflation ?) acted in the very early universe to endow it with these beautiful and simple properties. (author)

  14. Low background aspects of GERDA

    International Nuclear Information System (INIS)

    The GERDA experiment operates bare Germanium diodes enriched in 76Ge in an environment of pure liquid argon to search for neutrinoless double beta decay. A very low radioactive background is essential for the success of the experiment. We present here the research done in order to remove radio-impurities coming from the liquid argon, the stainless steel cryostat and the front-end electronics. We found that liquid argon can be purified efficiently from 222Rn. The main source of 222Rn in GERDA is the cryostat which emanates about 55 mBq. A thin copper shroud in the center of the cryostat was implemented to prevent radon from approaching the diodes. Gamma ray screening of radio-pure components for front-end electronics resulted in the development of a pre-amplifier with a total activity of less than 1 mBq 228Th.

  15. Background canceling surface alpha detector

    International Nuclear Information System (INIS)

    A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone. 5 figs

  16. Polarization of Cosmic Microwave Background

    CERN Document Server

    Buzzelli, Alessandro; de Gasperis, Giancarlo; Vittorio, Nicola

    2016-01-01

    In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross-correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales.

  17. The Cosmic Background Imager 2

    CERN Document Server

    Taylor, Angela C; Allison, James R; Angelakis, Emmanouil; Bond, J Richard; Bronfman, Leonardo; Bustos, Ricardo; Davis, Richard J; Dickinson, Clive; Leech, Jamie; Mason, Brian S; Myers, Steven T; Pearson, Timothy J; Readhead, Anthony C S; Reeves, Rodrigo; Shepherd, Martin C; Sievers, Jonathan L

    2011-01-01

    We describe an upgrade to the Cosmic Background Imager instrument to increase its surface brightness sensitivity at small angular scales. The upgrade consisted of replacing the thirteen 0.9-m antennas with 1.4-m antennas incorporating a novel combination of design features, which provided excellent sidelobe and spillover performance for low manufacturing cost. Off-the-shelf spun primaries were used, and the secondary mirrors were oversized and shaped relative to a standard Cassegrain in order to provide an optimum compromise between aperture efficiency and low spillover lobes. Low-order distortions in the primary mirrors were compensated for by custom machining of the secondary mirrors. The secondaries were supported on a transparent dielectric foam cone to minimize scattering. The antennas were tested in the complete instrument, and the beam shape and spillover noise contributions were as expected. We demonstrate the performance of the telescope and the inter-calibration with the previous system using observ...

  18. Gauging the cosmic microwave background

    International Nuclear Information System (INIS)

    We provide a new derivation of the anisotropies of the cosmic microwave background (CMB), and find an exact expression that can be readily expanded perturbatively. Close attention is paid to gauge issues, with the motivation to examine the effect of super-Hubble modes on the CMB. We calculate a transfer function that encodes the behavior of the dipole, and examine its long-wavelength behavior. We show that contributions to the dipole from adiabatic super-Hubble modes are strongly suppressed, even in the presence of a cosmological constant, contrary to claims in the literature. We also introduce a naturally defined CMB monopole, which exhibits closely analogous long-wavelength behavior. We discuss the geometrical origin of this super-Hubble suppression, pointing out that it is a simple reflection of adiabaticity, and hence argue that it will occur regardless of the matter content.

  19. Background paper on aquaculture research

    DEFF Research Database (Denmark)

    Wenblad, Axel; Jokumsen, Alfred; Eskelinen, Unto;

    Torrissen, Norway, Senior Advisory Scientist Unto Eskelinen, Finland and Senior Advisory Scientist Alfred Jokumsen, Denmark. The WG performed an investigation of the Swedish aquaculture sector including interviews with a range of stakeholders within aquaculture research, farming organisations, authorities......The Board of MISTRA established in 2012 a Working Group (WG) on Aquaculture to provide the Board with background information for its upcoming decision on whether the foundation should invest in aquaculture research. The WG included Senior Advisor Axel Wenblad, Sweden (Chairman), Professor Ole...... tonnes of crayfish altogether corresponding to a total value of SEK 328 million in 2011. Further about 1,000 tonnes of fish and crustaceans were produced for restocking as well as about 3 million fry of salmon and trout were released into rivers. Swedish aquaculture research was overall assessed...

  20. The scientific background to decorporation

    International Nuclear Information System (INIS)

    The scientific background to chelation therapy is reviewed. A review of the animal studies which have demonstrated that in animals treated with DTPA either a reduction in bone tumour incidence from internally deposited 239Pu and 241Am, or a significant increase in survival time may occur, suggests that it is reasonable to assume that could also occur in humans. The biokinetics and bioinorganic chemistry of cobalt, caesium, thorium, uranium, neptunium, plutonium and americium after their entry into the systemic circulation are reviewed briefly. These reviews discuss the general biokinetic behaviour of each element in adult humans with special reference to those aspects of their bioinorganic chemistry that either underlie existing approaches to decorporation therapy, or which might be exploitable for new types of treatment. (author)

  1. Recognizing foreground-background interaction

    Science.gov (United States)

    Jenkins, Jeffrey; Szu, Harold

    2010-04-01

    Can the background affect a foreground target in distant, low-quality imagery? If it does, it might occur in our mind, or perhaps it may represent a snapshot of our early vision. An affirmative answer, one way or another, may affect our current understanding of this phenomena and potentially for related applications. How can we be sure about this in the psycho-physical sense? We begin with the physiology of our brain's homeostasis, of which an isothermal equilibrium is characterized by the minimum of Helmholtz isothermal Free Energy: A = U - T0S >= 0, where T0 = 37°C, the Boltzmann Entropy S = KB1n(W), and U is the unknown internal energy to be computed.

  2. Gaussianity of LISA's confusion backgrounds

    International Nuclear Information System (INIS)

    different time scales, so no single background source closely resembles any search template. We also briefly discuss other types of LISA searches where the non-Gaussianity of LISA's confusion backgrounds could perhaps have a much greater impact on search reliability and efficacy

  3. Exploring the Moon

    CERN Document Server

    Harland, David M

    2008-01-01

    David Harland opens with a review of the robotic probes, namely the Rangers which returned television before crashing into the Moon, the Surveyors which ''soft landed'' in order to investigate the nature of the surface, and the Lunar Orbiters which mapped prospective Apollo landing sites. He then outlines the historic landing by Apollo 11 in terms of what was discovered, and how over the next several missions the program was progressively geared up to enable the final three missions each to spend three days on comprehensive geological investigations. He concludes with a review of the robotic spacecraft that made remote-sensing observations of the Moon. Although aimed at the enthusiast, and can be read as an adventure in exploration, the book develops the scientific theme of lunar geology, and therefore will be of use as background reading for undergraduate students of planetary sciences. In addition, with the prospect of a resumption of human missions, it will help journalists understand what Apollo achieved ...

  4. The Cosmic Background Radiation, 1995

    CERN Document Server

    Smoot, G F

    1995-01-01

    Observations of the Cosmic Microwave background have provided many of the most powerful constraints we have on cosmology and events in the early universe. The spectrum and isotropy of CBR have long been a pillar of Big Bang models. The discovery of low levels on anisotropy has provided new information and tools for our understanding of the early universe. Further observations promise to enhance greatly our knowledge of processes in the early universe and cosmological parameters. We can anticipate rapid advance in this field up to and through the year 2000 which will dramatically focus our efforts in cosmology during the next millenium. This paper outlines the primary science likely to be discovered and defined by a vigorous airborne and ground-based program which should be strongly supported. If successfully excuted, we an anticipate a measurement of the CBR anisotropy spectrum to within a factor of two of the confidence level unavoidably set by cosmic variance. Even so, observations of the CBR are the best a...

  5. Natural background radiation in Jordan

    International Nuclear Information System (INIS)

    An Airborne Gamma Ray survey has been accomplished for Jordan since 1979. A complete report has been submitted to the Natural Resources Authority along with field and processed data ''digital and analogue''. Natural radioelements concentration is not provided with this report. From the corrected count rate data for each natural radioelement, Concentrations and exposure rates at the ground level were calculated. Contoured maps, showing the exposure rates and the dose rates were created. Both maps reflect the surface geology of Jordan, where the Phosphate areas are very well delineated by high-level contours. In southeastern Jordan the Ordovician sandstone, which contain high percentage of Th (around 2000 ppm in some places) and a moderate percentage of U (about 300 ppm), also show high gamma radiation exposures compared with the surrounding areas. Comparing the values of the exposure rates given in (μR/h) to those obtained from other countries such as United States, Canada, Germany, etc. Jordan shows higher background radiation which reach two folds and even more than those in these countries. More detailed studies should be performed in order to evaluate the radiological risk limits on people who are living in areas of high radiation such that the area of the phosphatic belt which covers a vast area of Jordan high Plateau. (author)

  6. Background corrections using linear interpolation in airborne radiometric surveys

    International Nuclear Information System (INIS)

    The measurement of accurate background is essential for aeroradiometric data processing for the preparation of ground concentration maps of radioelements. High altitude background measurement methods currently employed in the Atomic Minerals Division shows a substantial time variation in many cases and poses the problem of right choice of background for data processing. The work described here, not only presents a simple practical technique to account for this variation but also suggests a few experiments to further explore the causative sources of this variation. This work provides several examples of background variations and presents a case study of Gangpur block for total and uranium window data which distinctly demonstrates this physical phenomenon. (author). 4 refs., 7 figs., 8 tabs

  7. Scientific background of the project

    International Nuclear Information System (INIS)

    The main objective of the proposed project is the development of radioimmunometric assay(s) for the determination of free and total PSA in serum samples from normal and pathological individuals (BPH, PCa). This will be achieved by: A. Selection of appropriate antibody pairs (capture and labelled antibody) for determination of total PSA (free and complex) and for determination of free PSA. From bibliography we have already spotted some antibody pairs. B. Radiolabelling of antibodies. Several labelling and purification procedures will be followed in order to obtain the required analytical sensitivity and dynamic range of the assays. Special attention will be given to the affinity constant as well as to the stability of the radiolabelled molecules. C. Development of protocols for immobilisation of capture antibodies. We will use several solid support formats (plastic tubes, beads and magnetizable particles). Direct adsorption or covalent binding will be used. Immunoadsorption through immobilised second antibody will be also tested in order to decrease the preparation cost of the solid phase reagents. D. Preparation of standards of suitable purity levels. We will test different PSA-free matrices (Bovine serum, buffer solutions etc.) in order to select the most appropriate among them in terms of low background determination and low reagents cost. E. Optimisation of the immunoassays conditions for the free PSA and total PSA (e.g. assay buffers, incubation time, temperature, one or two step procedure, washings). F. Optimisation and standardisation of assay protocols for kit production. G. Production of kits for distribution in clinical laboratories in Greece for comparison with commercial kits. H. Evaluation of the developed assays in real clinical conditions using well characterised human serum samples. This will be performed in co-operation with the Hellenic Society for Tumor Markers, and other anticancer institutions and hospital clinicians of long standing relation

  8. The Cosmic Microwave Background & Inflation, Then & Now

    Science.gov (United States)

    Bond, J. Richard; Contaldi, Carlo; Pogosyan, Dmitry; Mason, Brian; Myers, Steve; Pearson, Tim; Pen, Ue-Li; Prunet, Simon; Readhead, Tony; Sievers, Jonathan

    2002-12-01

    The most recent results from the Boomerang, Maxima, DASI, CBI and VSA CMB experiments significantly increase the case for accelerated expansion in the early universe (the inflationary paradigm) and at the current epoch (dark energy dominance). This is especially so when combined with data on high redshift supernovae (SN1) and large scale structure (LSS), encoding information from local cluster abundances, galaxy clustering, and gravitational lensing. There are ``7 pillars of Inflation'' that can be shown with the CMB probe, and at least 5, and possibly 6, of these have already been demonstrated in the CMB data: (1) the effects of a large scale gravitational potential, demonstrated with COBE/DMR in 1992-96 (2) acoustic peaks/dips in the angular power spectrum of the radiation, which tell about the geometry of the Universe, with the large first peak convincingly shown with Boomerang and Maxima data in 2000, a multiple peak/dip pattern shown in data from Boomerang and DASI (2nd, 3rd peaks, first and 2nd dips in 2001) and from CBI (2nd, 3rd, 4th, 5th peaks, 3rd, 4th dips at 1-sigma in 2002) (3) damping due to shear viscosity and the width of the region over which hydrogen recombination occurred when the universe was 400000 years old (CBI 2002) (4) the primary anisotropies should have a Gaussian distribution (be maximally random) in almost all inflationary models, the best data on this coming from Boomerang; (5) secondary anisotropies associated with nonlinear phenomena subsequent to 400000 years, which must be there and may have been detected by CBI and another experiment, BIMA. Showing the 5 ``pillars'' involves detailed confrontation of the experimental data with theory; e.g., (5) compares the CBI data with predictions from two of the largest cosmological hydrodynamics simulations ever done. DASI, Boomerang and CBI in 2002, AMiBA in 2003, and many other experiments have the sensitivity to demonstrate the next pillar, (6) polarization, which must be there at the ~ 7

  9. Cosmic microwave background acoustic peak locations

    Science.gov (United States)

    Pan, Z.; Knox, L.; Mulroe, B.; Narimani, A.

    2016-07-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and 12 extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g. that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 deg out of phase. However, there are large differences in expectations for extrema locations from simple analytic models versus numerical calculations. Here, we quantitatively explore the origin of these differences in gravitational potential transients, neutrino free-streaming, the breakdown of tight coupling, the shape of the primordial power spectrum, details of the geometric projection from three to two dimensions, and the thickness of the last scattering surface. We also compare the peak locations determined from Planck measurements to expectations under the Λ cold dark matter model. Taking into account how the peak locations were determined, we find them to be in agreement.

  10. Formation of Primordial Galaxies under UV background Radiation

    CERN Document Server

    Susa, H; Susa, Hajime; Umemura, Masayuki

    2000-01-01

    The pancake collapse of pregalactic clouds under UV background radiation is explored with a one-dimensional sheet model. Here, attention is concentrated on elucidating the basic physics on the thermal evolution of pregalactic clouds exposed to diffuse UV radiation. So, we treat accurately the radiation transfer for the ionizing photons, with solving chemical reactions regarding hydrogen molecules as well as atoms. The self-shielding against UV radiation by H$_2$ Lyman-Werner bands, which regulates the photo-dissociation of hydrogen molecules, is also taken into account. As a result, it is found that when the UV background radiation is at a level of $10^{-22} (\

  11. 电商背景下小微企业网络品牌构建的困境及解决对策初探%A Preliminary Exploration on Difficulties and Counter-measures of Micro Enterprises in Network Brand Building under the Background of E-commerce

    Institute of Scientific and Technical Information of China (English)

    冯伊翎; 郑黎栋

    2015-01-01

    Under the background of e-commerce, micro enter-prises begin to build their own network brands. On the way of building, they will encounter some difficulties, such as unclear brand foundations, insufficient funds, lack of professional talents, imperfect publicity programs . This article puts forward some advice through online investigation of micro enterprises and con-sumers to help enterprises build the network brands. For exam-ple, the micro enterprises should look for brand characteristics recognized by customers, or they can cooperate with universities, or use appropriate tools to advertise .%在电商背景下小微企业开始构建自己的网络品牌,在构建的道路上会遇到品牌基础不清晰、投资资金不足、缺少专业人才、没有完善的宣传方案等困境,本文通过对小微企业和消费者的网购情况调查对小微企业的品牌构建提出寻找品牌特色,得到顾客认可,和大学合作,利用合适的工具宣传等对策,帮助企业构建网络品牌。

  12. 《侵权责任法》背景下临床决策新路径与方法探讨%Exploration of New Paths and Methods of Clinical Decision Making under the Background of China's New Tort Liability Law

    Institute of Scientific and Technical Information of China (English)

    王锦帆

    2011-01-01

    我国新颁布实施的对临床决策产生了重大影响,需要我们医务人员高度认识新法律的地位与作用,需要认识临床决策的真正内涵.通过深化医患沟通职能建设、患方参与医疗小组、健全医患权益协议书、加强患者医学与健康教育等,探索临床决策的新路径和方法.%China's new Tort Liability Law brought a significant impact on clinical decision making. Medical staff needed for high awareness of the new law's position and effect, and needed to know the real meaning of clinical decision making. This paper will explore new paths and methods of clinical decision making through deepening the function of doctor- patient communication; the patients' participation in the medical team; perfecting doctor- patient rights and interests agreement;and strengthening patient medicine and health education,ete .

  13. Exploration Medical System Demonstration

    Science.gov (United States)

    Rubin, D. A.; Watkins, S. D.

    2014-01-01

    BACKGROUND: Exploration class missions will present significant new challenges and hazards to the health of the astronauts. Regardless of the intended destination, beyond low Earth orbit a greater degree of crew autonomy will be required to diagnose medical conditions, develop treatment plans, and implement procedures due to limited communications with ground-based personnel. SCOPE: The Exploration Medical System Demonstration (EMSD) project will act as a test bed on the International Space Station (ISS) to demonstrate to crew and ground personnel that an end-to-end medical system can assist clinician and non-clinician crew members in optimizing medical care delivery and data management during an exploration mission. Challenges facing exploration mission medical care include limited resources, inability to evacuate to Earth during many mission phases, and potential rendering of medical care by non-clinicians. This system demonstrates the integration of medical devices and informatics tools for managing evidence and decision making and can be designed to assist crewmembers in nominal, non-emergent situations and in emergent situations when they may be suffering from performance decrements due to environmental, physiological or other factors. PROJECT OBJECTIVES: The objectives of the EMSD project are to: a. Reduce or eliminate the time required of an on-orbit crew and ground personnel to access, transfer, and manipulate medical data. b. Demonstrate that the on-orbit crew has the ability to access medical data/information via an intuitive and crew-friendly solution to aid in the treatment of a medical condition. c. Develop a common data management framework that can be ubiquitously used to automate repetitive data collection, management, and communications tasks for all activities pertaining to crew health and life sciences. d. Ensure crew access to medical data during periods of restricted ground communication. e. Develop a common data management framework that

  14. Dark Matter in ms1224 from Distortion of Background Galaxies

    OpenAIRE

    Fahlman, G. G.; Kaiser, Nick; Squires, Gordon; Woods, David

    1994-01-01

    We explore the dark matter distribution in ms1224.7+2007 using the gravitational distortion of the images of faint background galaxies. Projected mass image reconstruction reveals a highly significant concentration coincident with the X-ray and optical location. The concentration is seen repeatably in reconstructions from independent subsamples and the azimuthally averaged tangential shear pattern is also clearly seen in the data. The projected mass within a $2.76'$ radius aperture is $\\simeq...

  15. Dialogic oriented book reading for children with migration backgrounds

    OpenAIRE

    Ping, Maria Teodora

    2011-01-01

    This study aimed at getting an insight to the practices of dialogic oriented shared book reading, as one potential language promotion activity for children with migration backgrounds in German kindergartens. Shared book reading in Germany itself has been one common daily activity in kindergartens, yet it has unfortunately not been so much of a specific research focus to be explored. One of the notable studies to refer to when discussing shared book reading in the German context...

  16. AdS backgrounds from black hole horizons

    International Nuclear Information System (INIS)

    We utilize the classification of IIB horizons with 5-form flux to present a unified description for the geometry of AdSn, n = 3, 5, 7 solutions. In particular, we show that all such backgrounds can be constructed from eight-dimensional 2-strong Calabi–Yau geometries with torsion which admit some additional isometries. We explore the geometry of AdS3 and AdS5 solutions but we do not find AdS7 solutions. (paper)

  17. IQ and Family Background: Are Associations Strong or Weak?

    OpenAIRE

    Björklund, Anders; Eriksson, Karin Hederos; Jäntti, Markus

    2009-01-01

    For the purpose of understanding the underlying mechanisms behind intergenerational associations in income and education, recent studies have explored the intergenerational transmission of abilities. We use a large representative sample of Swedish men to examine both intergenerational and sibling correlations in IQ. Since siblings share both parental factors and neighbourhood influences, the sibling correlation is a broader measure of the importance of family background than the intergenerati...

  18. Image segmentation by background extraction refinements

    Science.gov (United States)

    Rodriguez, Arturo A.; Mitchell, O. Robert

    1990-01-01

    An image segmentation method refining background extraction in two phases is presented. In the first phase, the method detects homogeneous-background blocks and estimates the local background to be extracted throughout the image. A block is classified homogeneous if its left and right standard deviations are small. The second phase of the method refines background extraction in nonhomogeneous blocks by recomputing the shoulder thresholds. Rules that predict the final background extraction are derived by observing the behavior of successive background statistical measurements in the regions under the presence of dark and/or bright object pixels. Good results are shown for a number of outdoor scenes.

  19. 大数据背景下政府治理模式现代化研究--亳州市网上办事大厅的探索与实践%A Study on Modernization of Governance Model under the Background of Big Data---An Exploration and Practice of the Online Service Hall in Bozhou City

    Institute of Scientific and Technical Information of China (English)

    刘华景

    2016-01-01

    Based on the exploration and practice of Bozhou City online services hall ,from the four aspects as agglutination clear objectives ,re‐integration of resources ,effective use of tools ,and scientifically control re‐sponsibility ,the paper analyzes main practice of the city ,and describes its practical value of this new mode of government services .T hrough research ,it points out that some development bottleneck problems exist .For example ,materials are submitted repeatedly ;it is in the early and middle stage of application ;and there is lack of information sharing between part of the administrative department .Taking these as a breakthrough ,it helps the government decision -making with the suggestions of building a unified information platform to share resources ,and unify deployment of online business hall at the grass‐roots level on the basis of strength‐ening the online supervision ,improving the service consciousness ,comply with the classified grades .%立足于安徽省亳州市网上办事大厅的探索和实践,从凝聚明确目标、重新整合资源、有效运用工具、科学控制责任等四个方面分析了该市的主要做法,并就这种新型政务服务模式在“变”“重”“零”成效方面的实践价值进行描述。通过调研,指出其在提交材料的重复性、办事大厅还处在初中级应用阶段、部分行政部门之间缺乏信息共享等方面存在发展瓶颈问题,提出以此为突破口,强化网上监督,提高服务意识,按涉密等级构建统一的信息共享资源平台,统一部署基层网上办事大厅等对策建议。

  20. Exploring the Universe.

    Science.gov (United States)

    Aviation/Space, 1982

    1982-01-01

    Highlights National Aeronautics and Space Administration's (NASA) space exploration studies, focusing on Voyager at Saturn, advanced Jupiter exploration, infrared observatory, space telescope, Dynamics Explorers (satellites designed to provide understanding of earth/sun energy relationship), and ozone studies. (JN)

  1. Extended Mosaic Observations with the Cosmic Background Imager

    CERN Document Server

    Readhead, A C S; Contaldi, C R; Pearson, T J; Bond, J R; Myers, S T; Padin, S; Sievers, J L; Cartwright, J K; Shepherd, M C; Pogosyan, D; Prunet, S; Altamirano, P; Bustos, R; Bronfman, L; Casassus, S; Holzapfel, W L; May, J; Pen, U L; Torres, S; Udomprasert, P S

    2004-01-01

    Two years of microwave background observations with the Cosmic Background Imager (CBI) have been combined to give a sensitive, high resolution angular power spectrum over the range 400 2000 power previously seen with the CBI is reduced. Under the assumption that any signal in excess of the primary anisotropy is due to a secondary Sunyaev-Zeldovich anisotropy in distant galaxy clusters we use CBI, ACBAR, and BIMA data to place a constraint on the present-day rms mass fluctuation sigma_8. We present the results of a cosmological parameter analysis on the l < 2000 primary anisotropy data which show significant improvements in the parameters as compared to WMAP alone, and we explore the role of the small-scale cosmic microwave background data in breaking parameter degeneracies.

  2. Non-singlet Baryons in Less Supersymmetric Backgrounds

    CERN Document Server

    Giataganas, Dimitrios; Picos, Marco; Siampos, Konstadinos

    2012-01-01

    We analyze the holographic description of non-singlet baryons in various backgrounds with reduced supersymmetries and/or confining. We show that they exist in all AdS_5xY_5 backgrounds with Y_5 an Einstein manifold bearing five form flux, for a number of quarks 5N/8< k< N, independently on the supersymmetries preserved. This result still holds for gamma_i deformations. In the confining Maldacena-Nunez background non-singlet baryons also exist, although in this case the interval for the number of quarks is reduced as compared to the conformal case. We generalize these configurations to include a non-vanishing magnetic flux such that a complementary microscopical description can be given in terms of lower dimensional branes expanding into fuzzy baryons. This description is a first step towards exploring the finite 't Hooft coupling region.

  3. Accoustic background of BN-600 steam generator

    International Nuclear Information System (INIS)

    In this paper the results of accoustic background for BN-600 steam generator in nominal operating conditions are presented. The 1-200 kHz accoustic background of evaporator and reheater modules are given

  4. 节能减排背景下我国化石能源勘探开发利用的科技应对策略%Strategic countermeasures of science and technology for the exploration, development and utilization of fossil energy in the background of energy-saving and emission-reduction

    Institute of Scientific and Technical Information of China (English)

    樊俊; 杨军; 瞿辉

    2015-01-01

    Fossil energy represented by coal ,petroleum and natural gas will be the main component of energy consumption in China for a long period in the future .In recent years ,the Chinese government has been pushing forward energy-saving and emission-reduction to adjust the economic structure and transform the development pattern ,scientific and technological innovation has become the inevitable choice to promote the efficiency and quality of fossil energy industry and to advance the sustainable development in China .The research and development work on fossil energy could follow the global trend ,which was described as multivariate ,green and scientific development ,and the promising breakthrough points could be fixed on delicate and in-depth exploration ,safe and effective development as well as intensive and economical use . Taking the market demand as guide ,the research and development work in this field could be emphasized on basic theory ,key technology ,major equipment ,demonstration project construction and innovative platform construction ,so as to promote the capability of independent innovation and the core competence of enterprises and industries .The ultimate goals of the innovation in fossil energy industry are:① to push the transformation of coal industry towards a green ,safe ,efficient ,economic and scientific development phase;②to expand the reserves and maintain the yield of petroleum ;③to promote the development of natural gas;④to cultivate theunconventional oil and gas to serve as the new source of energy supply .The above efforts would play a key role in ensuring the energy security and optimizing the energy structure of China .%未来较长一段时期,以煤炭、石油和天然气为代表的化石能源仍将占据我国能源消费结构的主体地位。在以节能减排为抓手促进经济结构调整、发展方式转变的宏观背景下,科技创新成为我国化石能源开发利用这一传统产业提质增效和可持

  5. Background subtraction using probabilistic event weights

    OpenAIRE

    Wang, Yadi; Liu, Beijiang; Shen, Xiaoyan; Zhang, Ziping

    2014-01-01

    Background treatment is crucial to extract physics from precision experiments. In this paper, we introduce a novel method to assign each event a signal probability. This could then be used to weight the event's contribution to the likelihood during fitting. To illustrate the effect of this method, we test it with MC samples. The consistence between the constructed background and the background from MC truth shows that the background subtraction method with probabilistic event weights is feasi...

  6. Beam-Generated Detector Backgrounds at CESR

    OpenAIRE

    Henderson, Stuart; Cinabro, David

    2000-01-01

    The CESR/CLEO Phase II interaction region is described. The operational experience with beam-generated detector backgrounds is reviewed. The status of our understanding of beam-generated detector backgrounds at CESR is described and comparisons of background measurements with simulation predictions are presented.

  7. On high energy scattering inside gravitational backgrounds

    OpenAIRE

    Nastase, Horatiu

    2004-01-01

    We analyze the high energy scattering inside gravitational backgrounds using 't Hooft's formalism. The scattering is equivalent to geodesic shifts accross Aichelburg-Sexl waves inside the gravitational backgrounds. We find solutions for A-S waves inside various backgrounds and analyze them.

  8. A Background-Free Direction-Sensitive Neutron Detector2 A Background-Free Direction-Sensitive Neutron Detector

    CERN Document Server

    Roccaro, Alvaro; Ahlen, S; Avery, D; Inglis, A; Battat, J; Dujmic, D; Fisher, P; Henderson, S; Kaboth, A; Kohse, G; Lanza, R; Monroe, J; Sciolla, G; Skvorodnev, N; Wellenstein, H; Yamamoto, R

    2009-01-01

    We show data from a new type of detector that can be used to determine neutron flux, energy distribution, and direction of neutron motion for both fast and thermal neutrons. Many neutron detectors are plagued by large backgrounds from x-rays and gamma rays, and most current neutron detectors lack single-event energy sensitivity or any information on neutron directionality. Even the best detectors are limited by cosmic ray neutron backgrounds. All applications (neutron scattering and radiography, measurements of solar and cosmic ray neutron flux, measurements of neutron interaction cross sections, monitoring of neutrons at nuclear facilities, oil exploration, and searches for fissile weapons of mass destruction) will benefit from the improved neutron detection sensitivity and improved measurements of neutron properties made possible by this detector. The detector is free of backgrounds from x-rays, gamma rays, beta particles, relativistic singely charged particles and cosmic ray neutrons. It is sensitive to th...

  9. Extragalactic Background Light: Measurements and Applications

    CERN Document Server

    Cooray, Asantha

    2016-01-01

    This review covers the measurements related to the extragalactic background light (EBL) intensity from gamma-rays to radio in the electromagnetic spectrum over 20 decades in the wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centered at 1 microns, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar system. The best measurements of COB come from an indirect technique involving Gamma-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 microns established an energetically important background with an intensity comparable to the optical background. This discovery paved the path for large aperture far-infrared and sub-millimeter observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy for...

  10. Environmental background assessment: basic principles and practice

    International Nuclear Information System (INIS)

    Background assessment is crucial in setting remediation and management goals, in identifying contamination trends and in providing screening tools for the selection of contaminants of concern. Legal requirements and guideline documents place great emphasis onto the establishment of background levels. This contribution discusses background estimates for metals and organics in relation to bioavailability and to its potential impact onto living systems. Methods for defining background in Environmental Risk Assessment are provided by the US EPA and by the Dutch Added Risk Approach. Cited case studies, taken from projects carried out in Italy and abroad, show that practical approaches vary significantly. A standardised database of soil, sediment and water background levels for different contaminants, as well as a more comprehensive guideline of background assessment, are urgently needed

  11. Perturbative Double Field Theory on General Backgrounds

    CERN Document Server

    Hohm, Olaf

    2015-01-01

    We develop the perturbation theory of double field theory around arbitrary solutions of its field equations. The exact gauge transformations are written in a manifestly background covariant way and contain at most quadratic terms in the field fluctuations. We expand the generalized curvature scalar to cubic order in fluctuations and thereby determine the cubic action in a manifestly background covariant form. As a first application we specialize this theory to group manifold backgrounds, such as $SU(2) \\simeq S^3$ with $H$-flux. In the full string theory this corresponds to a WZW background CFT. Starting from closed string field theory, the cubic action around such backgrounds has been computed before by Blumenhagen, Hassler and L\\"ust. We establish precise agreement with the cubic action derived from double field theory. This result confirms that double field theory is applicable to arbitrary curved background solutions, disproving assertions in the literature to the contrary.

  12. CMB with the background primordial magnetic field

    CERN Document Server

    Yamazaki, Dai G

    2014-01-01

    We investigate the effects of the background primordial magnetic field (PMF) on the cosmic microwave background (CMB). The sound speed of the tightly coupled photon-baryon fluid is increased by the background PMF. The increased sound speed causes the odd peaks of the CMB temperature fluctuations to be suppressed and the CMB peak positions to be shifted to a larger scale. The background PMF causes a stronger decaying potential and increases the amplitude of the CMB. These two effects of the background PMF on a smaller scale cancel out, and the overall effects of the background PMF are the suppression of the CMB around the first peak and the shifting of peaks to a large scale. We also discuss obtaining information about the PMF generation mechanisms, and we examine the nonlinear evolution of the PMF by the constraint on the maximum scale for the PMF distributions. Finally, we discuss degeneracies between the PMF parameters and the standard cosmological parameters.

  13. Improving foreground detection for adaptive background segmentation

    OpenAIRE

    Huerta, Iván; Rowe, Daniel; Gonzàlez, Jordi; Villanueva, Juan J.

    2006-01-01

    This paper tries to manage with the nonincorporation of erroneous foreground objects to the background model, and the incorporation of those detected objects which cease their movement. These newly motionless foreground objects should be handled in security domains such as video surveillance. This paper uses an adaptive background modelling algorithm for moving object detection. Those detected objects which present no motion are identified and added into the background model, so that they wil...

  14. On Cultural Background Knowledge in English Reading

    Institute of Scientific and Technical Information of China (English)

    苏琴; 郭成

    2009-01-01

    Reading comprehension is undoubtedly one of the most important abilities for English learners. This paper firstly makes a brief introduction to the reading theory and cultural background knowledge. Then using schema theory and typical examples, the paper demons~ates the role of cultural background knowledge in reading comprehension. The application of cultural background knowledge inreading practice is proposed as the keys to the improvement of reading comprehension ability.

  15. PENGARUH BACKGROUND MAHASISWA TERHADAP KINERJA AKADEMIK

    OpenAIRE

    Trianasari Angkawijaya; Yenny Sugiarti

    2014-01-01

    Abstract: The Effect of Students’ Background on Academic Performance. This study examines the effect of background variables on the academic performance of accounting students in a private university in Surabaya. The background variables under study included previous academic performance, prior knowledge on accounting, sex, motivation, preparedness, and expectations. The results show that previous academic performance, motivation, and expectations have positive and significant effects on the ...

  16. Backgrounds for tagging Bs events at LEP

    International Nuclear Information System (INIS)

    The final state Ds+l+anti νl+... occurring in Z0-decay is analyzed, and backgrounds to the decay chain (i) Z0→Bs+..., (ii) Bs→Ds+l+anti νl+... are estimated. A resonance description is used to model the dominant source of background, and a numerical study yields estimates for the background-to-signal ratio of several per cent as input parameters are varied. (orig.)

  17. Gauge theories with non-trivial backgrounds

    CERN Document Server

    Binosi, Daniele

    2014-01-01

    We review our most recent results in formulating gauge theories in the presence of a background field on the basis of symmetry arguments only. In particular we show how one can gain full control over the dependence on the background field of the effective action, and how the so-called background field method emerges naturally from the requirement of invariance under the BRST and antiBRST symmetries.

  18. Thermal inflation and the gravitational wave background

    International Nuclear Information System (INIS)

    We consider the impact of thermal inflation—a short, secondary period of inflation that can arise in supersymmetric scenarios—on the stochastic gravitational wave background. We show that while the primordial inflationary gravitational wave background is essentially unchanged at cosmic microwave background scales, it is massively diluted at solar system scales and would be unobservable by a Big Bang Observer (BBO) style experiment. Conversely, bubble collisions at the end of thermal inflation can generate a new stochastic background. We calculate the likely properties of the bubbles created during this phase transition, and show that the expected amplitude and frequency of this signal would fall within the BBO range

  19. Why your practice must do background checks.

    Science.gov (United States)

    Zupko, Karen

    2007-01-01

    Hiring qualified staff is critical for a medical practice. As many physicians have discovered, taking applicants' resumes on faith can be a mistake. Background company searches show that one in three applicants provide false, inaccurate, misleading, or incomplete information. Fake degrees, false licenses and certifications, and criminal histories are a few of the problems that a proper background check can reveal. This article describes further why background checks are essential, how to incorporate a background check into your hiring process, and some of the legalities involved in the process. PMID:17494489

  20. Exploring domestic energy-saving: The role of environmental concern and background variables

    International Nuclear Information System (INIS)

    The main purpose of this paper is to investigate whether residents' environmental concern has any effect on their energy-saving curtailments and efficiency investments. The novelty of the present work lies in the fact that it seeks to investigate this topic in a multi-country setting, exploiting data from nine OECD countries (Australia, Canada, Czech Republic, France, Italy, South Korea, Netherlands, Norway and Sweden), and also in that it employs a latent variable model which allows us to examine the conditions necessary for the results to be comparable across different countries. Novel in this paper is also the focus on the role of environmental concern as a factor of several curtailments and efficiency investments. Our results suggest that people with higher environmental concern are on average more likely to perform energy-saving curtailments and also are more likely to have some energy-efficiency retrofits installed in dwellings. Most of the socio-economic and demographic variables have mixed effects on efficiency investments and curtailments. However, some interesting patterns emerged with respect to the age of respondents, household income, education and gender of respondents, and also the size of household. - Highlights: ► People with higher environmental concern are more likely to perform energy-saving curtailments. ► People with higher environmental concern are more likely to introduce some energy efficiency retrofits. ► Older people are more concerned about environmental problems, invest in efficiency and curtail more. ► Formal level of education does not play prominent role with respect to domestic energy-saving. ► Wealthier people are more likely to invest in energy efficiency but less likely to curtail.

  1. LETs and NETs: Exploring How Teachers from Diverse Cultural Backgrounds Impact Student Motivation and Preferences

    Science.gov (United States)

    Wong, Ruth

    2014-01-01

    This paper, an exploratory case study, examines how students' preferences and motivation to learn English are influenced by their perceptions of teaching practices--both of native English teachers and local English teachers. To better understand the context of this research question, this study adopts a method of triangulation in collecting data:…

  2. A Trigonometric Exploration.

    Science.gov (United States)

    DiDomenico, Angelo S.

    1992-01-01

    Gives an example of an open exploration using trigonometric relationships in which the law of cosines can be deduced from the law of sines. Discusses the characteristics and value of the exploration process. (MDH)

  3. Exploration and Mining Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2002-09-01

    This Exploration and Mining Technology Roadmap represents the third roadmap for the Mining Industry of the Future. It is based upon the results of the Exploration and Mining Roadmap Workshop held May 10 ñ 11, 2001.

  4. Supermembrane actions for Gaiotto-Maldacena backgrounds

    OpenAIRE

    Stefanski, B.

    2013-01-01

    We write down the supermembrane actions for M-theory backgrounds dual to general N=2 four-dimensional superconformal field theories. The actions are given to all orders in fermions and are in a particular κ -gauge. When an extra U(1) isometry is present, our actions reduce to κ -gauge fixed Green–Schwarz actions for the corresponding Type IIA backgrounds.

  5. 45 CFR 650.16 - Background rights.

    Science.gov (United States)

    2010-10-01

    ... Background rights. The Foundation will acquire rights to a research performer's pre-existing technology only... of the Bayh-Dole Act (35 U.S.C. 202(f)) as implemented by 37 CFR 401.12). ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Background rights. 650.16 Section 650.16...

  6. 32 CFR 770.54 - Background.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Background. 770.54 Section 770.54 National... Hampshire § 770.54 Background. (a) Portsmouth Naval Shipyard maintains and operates facilities “to provide... assigned; to perform manufacturing, research, development, and test work, as assigned; and to...

  7. 47 CFR 215.1 - Background.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Background. 215.1 Section 215.1... POINT FOR ELECTROMAGNETIC PULSE (EMP) INFORMATION § 215.1 Background. (a) The nuclear electromagnetic... available protective measures, and in order to avoid duplication of research efforts, it is desirable...

  8. Exploration cost-cutting

    Energy Technology Data Exchange (ETDEWEB)

    Huttrer, J.

    1996-12-31

    This presentation by Jerry Huttrer, President, Geothermal Management Company, discusses the general state of exploration in the geothermal industry today, and mentions some ways to economize and perhaps save costs of geothermal exploration in the future. He suggests an increased use of satellite imagery in the mapping of geothermal resources and the identification of hot spots. Also, coordinating with oil and gas exploration efforts, the efficiency of the exploration task could be optimized.

  9. A Vigorous Explorer Program

    OpenAIRE

    Elvis, Martin; Beasley, Matthew; Brissenden, Roger; Chakrabarti, Supriya; Cherry, Michael; Devlin, Mark; Edelstein, Jerry; Eisenhardt, Peter; Feldman, Paul; Ford, Holland; Gehrels, Neil; Golub, Leon; Marshall, Herman; Martin, Christopher; Mather, John

    2009-01-01

    Explorers have made breakthroughs in many fields of astrophysics. The science from both these missions contributed to three Nobel Prizes - Giacconi (2002), Mather, and Smoot (2006). Explorers have: marked the definitive beginning of precision cosmology, discovered that short gamma-ray bursts are caused by compact star mergers and have measured metalicity to redshifts z>6. NASA Explorers do cutting-edge science that cannot be done by facility-class instruments. The Explorer program provides a ...

  10. Gravitational wave background from binary systems

    CERN Document Server

    Rosado, Pablo A

    2011-01-01

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter $\\Omega(f)$, commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, $\\Omega(f)$ is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the ...

  11. Microwave background constraints on mixing of photons with hidden photons

    International Nuclear Information System (INIS)

    Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of the Cosmic Background Explorer. Requiring the distortions of the CMB induced by the photon-hidden photon mixing to be smaller than experimental upper limits, this leads to a bound on the mixing angle χ0 -7 - 10-5 for hidden photon masses between 10-14 eV and 10-7 eV. This low-mass and low-mixing region of the hidden photon parameter space was previously unconstrained. (orig.)

  12. PENGARUH BACKGROUND MAHASISWA TERHADAP KINERJA AKADEMIK

    Directory of Open Access Journals (Sweden)

    Trianasari Angkawijaya

    2014-09-01

    Full Text Available Abstract: The Effect of Students’ Background on Academic Performance. This study examines the effect of background variables on the academic performance of accounting students in a private university in Surabaya. The background variables under study included previous academic performance, prior knowledge on accounting, sex, motivation, preparedness, and expectations. The results show that previous academic performance, motivation, and expectations have positive and significant effects on the students’ overall academic performance in accounting, while preparedness affects only the students’ performance in management accounting. In contrast, prior knowledge on accounting and sex do not give significant impacts to the students’ overall academic performance.These findings indicate the importance of previous aca­demic performance as well as motivation and expectations as background variables in current academic performance. Keywords: students’ background, academic performance, accounting Abstrak: Pengaruh Background Mahasiswa terhadap Kinerja Akademik. Penelitian ini mengkaji pengaruh variabel background terhadap kinerja akademik mahasiswa akuntansi di Universitas Surabaya. Lima variabel background utama dipergunakan, yaitu kinerja akademik sebelumnya, pengetahuan akun­tansi sebelumnya, jenis kelamin, motivasi, kesiapan, dan ekspektasi. Hipotesis diuji menggunakan model regresi linier berganda OLS dan Robust Standar Error. Hasil penelitian memerlihatkan bahwa kinerja akademik sebelumnya, motivasi, dan ekspektasi memiliki pengaruh positif signifikan terhadap kinerja akademik keseluruhan, sementara kesiapan memberikan pengaruh positif hanya pada kinerja akademik akuntansi manajemen. Sebaliknya, pengetahuan akuntansi sebelumnya dan jenis kelamin tidak memberi­kan pengaruh signifikan terhadap kinerja akademik keseluruhan. Temuan ini mengindikasikan bahwa kinerja akademik sebelumnya beserta motivasi dan ekspektasi adalah variabel background

  13. The prospects for polarized target materials with pure carbon background

    International Nuclear Information System (INIS)

    None of the materials presently in common use for polarized proton targets has a pure carbon nuclear background. The alcohols and diols contain some oxygen, and the ammonia and amine-based materials contain nitrogen and/or other noncarbon species. In the latter cases the noncarbon nuclei are measurably polarized as a concomitant of the process used to polarize the hydrogen nuclei. The relative simplicity of a pure carbon background would be advantageous for most types of scattering experiments and perhaps crucial for some. In addition to simplifying the kinematics of background events, pure carbon is relatively easy to prepare as a ''dummy'' target for background subtraction. Also, in such a target material, 13C-enrichment would yield a clean polarized 13C material. In this note I explore the possibilities for such materials, touching upon only what I consider to be the ''high'' points. The subject matter is capable of nearly endless ramification and speculation. In fact, owing to a general lack of relevant experimental data, even this relatively brief note contains much that is speculative to some degree

  14. String pair production in non homogeneous backgrounds

    Science.gov (United States)

    Bolognesi, S.; Rabinovici, E.; Tallarita, G.

    2016-04-01

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  15. Lorentz-invariant ensembles of vector backgrounds

    International Nuclear Information System (INIS)

    We consider gauge field theories in the presence of ensembles of vector backgrounds. While Lorentz invariance is explicitly broken in the presence of any single background, here, the Lorentz invariance of the theory is restored by averaging over a Lorentz-invariant ensemble of backgrounds, i.e., a set of background vectors that is mapped onto itself under Lorentz transformations. This framework is used to study the effects of a non-trivial but Lorentz-invariant vacuum structure or mass dimension two vector condensates by identifying the background with a shift of the gauge field. Up to now, the ensembles used in the literature comprise configurations corresponding to non-zero field tensors together with such with vanishing field strength. We find that even when constraining the ensembles to pure gauge configurations, the usual high-energy degrees of freedom are removed from the spectrum of asymptotic states in the presence of said backgrounds in Euclidean and in Minkowski space. We establish this result not only for the propagators to all orders in the background and otherwise at tree level but for the full propagator

  16. Algebraic aspects of the background field method

    International Nuclear Information System (INIS)

    The background field method allows the evaluation of the effective action by exploiting the (background) gauge invariance, which in general yields Ward identities, i.e., linear relations among the vertex functions. In the present approach an extra gauge fixing term is introduced right at the beginning in the action and it is chosen in such a way that BRST invariance is preserved. The background effective action is considered and it is shown to satisfy both the Slavnov-Taylor (ST) identities and the Ward identities. This allows the proof of the background equivalence theorem with the standard techniques. In particular we consider a BRST doublet where the background field enters with a non-zero BRST transformation. The rationale behind the introduction of an extra gauge fixing term is that of removing the singularity of the Legendre transform of the background effective action, thus allowing the construction of the connected amplitudes generating functional Wbg. By using the relevant ST identities we show that the functional Wbg gives the same physical amplitudes as the original one we started with. Moreover we show that Wbg cannot in general be derived from a classical action by the Gell-Mann-Low formula. As a final point of the paper we show that the BRST doublet generated from the background field does not modify the anomaly of the original underlying gauge theory. The proof is algebraic and makes no use of arguments based on power-counting

  17. Sources of the Radio Background Considered

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  18. Sources of the Radio Background Considered

    International Nuclear Information System (INIS)

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub μJy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/γ-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  19. Radiation background of Black Sea coastal environment

    International Nuclear Information System (INIS)

    The main objective of the project is to establish the level of radiation background and its sources in the Black Sea coastal environment. Marine samples will be collected in the Black Sea Coast area. The content of different radionuclides will be analyzed and the results will be used in a GIS application. The gamma emitting radionuclides will be measured in ultralow radiation background in the Romanian underground laboratory in salt mine in Slanic-Prahova. The main expected results is an up to date quantification of the radiation sources of the background of the Black Sea coastal environment. (authors)

  20. LAr instrumentation studies for low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Janicsko Csathy, Jozsef [Technische Universitaet Muenchen (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    We investigated different options to instrument a large volume of liquid Argon in a low background experiment like GERDA with special regard to alternatives to PMTs. The difficulty consists in producing all the components with a radiopurity that is compatible with the background goal of the experiment. WLS fibers read out with SiPMs seem to offer the best compromise between veto efficiency and induced background. We present optimization studies for about one ton instrumented LAr volume and preliminary results from our test stand at TUM.

  1. The astrophysical gravitational wave stochastic background

    Institute of Scientific and Technical Information of China (English)

    Tania Regimbau

    2011-01-01

    A stochastic background of gravitational waves with astrophysical origins may have resulted from the superposition of a large number of unresolved sources since the beginning of stellar activity.Its detection would put very strong constraints on the physical properties of compact objects, the initial mass function and star formarion history.On the other hand, it could be a ‘noise' that would mask the stochastic background of its cosmological origin.We review the main astrophysical processes which are able to produce a stochastic background and discuss how they may differ from the primordial contribution in terms of statistical properties.Current detection methods are also presented.

  2. Gravity with background fields and diffeomorphism breaking

    CERN Document Server

    Bluhm, Robert

    2016-01-01

    Effective gravitational field theories with background fields break local Lorentz symmetry and diffeomorphism invariance. Examples include Chern-Simons gravity, massive gravity, and the Standard-Model Extension (SME). The physical properties and behavior of these theories depend greatly on whether the spacetime symmetry breaking is explicit or spontaneous. With explicit breaking, the background fields are fixed and nondynamical, and the resulting theories are fundamentally different from Einstein's General Relativity (GR). However, when the symmetry breaking is spontaneous, the background fields are dynamical in origin, and many of the usual features of Einstein's GR still apply.

  3. Do instantons like a colorful background?

    Energy Technology Data Exchange (ETDEWEB)

    Gies, H.; Pawlowski, J.M.; Wetterich, C. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Jaeckel, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-08-15

    We investigate chiral symmetry breaking and color symmetry breaking in QCD. The effective potential of the corresponding scalar condensates is discussed in the presence of non-perturbative contributions from the semiclassical one-instanton sector. We concentrate on a color singlet scalar background which can describe chiral condensation, as well as a color cotet scalar background which can generate mass for the gluons. Whereas a non-vanishing singlet chiral field is favored by the instantons, we have found no indication for a preference of color octet backgrounds. (orig.)

  4. Nontrivial classical backgrounds with vanishing quantum corrections

    International Nuclear Information System (INIS)

    Vacuum polarization and particle production effects in classical electromagnetic and gravitational backgrounds can be studied by the effective Lagrangian method. Background field configurations for which the effective Lagrangian is zero are special in the sense that the lowest order quantum corrections vanish for such configurations. We propose here the conjecture that there will be neither particle production nor vacuum polarization in classical field configurations for which all the scalar invariants are zero. We verify this conjecture, by explicitly evaluating the effective Lagrangian, for nontrivial electromagnetic and gravitational backgrounds with vanishing scalar invariants. The implications of this result are discussed. copyright 1997 The American Physical Society

  5. The Primordial Inflation Explorer (PIXIE)

    Science.gov (United States)

    Kogut, Alan; Chuss, David T.; Dotson, Jessie; Dwek, Eli; Fixsen, Dale J.; Halpern, Mark; Hinshaw, Gary F.; Meyer, Stephan; Moseley, S. Harvey; Seiffert, Michael D.; Spergel, David N.; Wollack, Edward J.

    2014-01-01

    The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). Multi-moded non-imaging optics feed a polarizing Fourier Transform Spectrometer to produce a set of interference fringes, proportional to the difference spectrum between orthogonal linear polarizations from the two input beams. Multiple levels of symmetry and signal modulation combine to reduce the instrumental signature and confusion from unpolarized sources to negligible levels. PIXIE will map the full sky in Stokes I, Q, and U parameters with angular resolution 2.6 deg and sensitivity 0.2 µK per 1 deg square pixel. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r less than 10(exp -3) at 5 standard deviations. In addition, PIXIE will measure the absolute frequency spectrum to constrain physical processes ranging from inflation to the nature of the first stars to the physical conditions within the interstellar medium of the Galaxy. We describe the PIXIE instrument and mission architecture with an emphasis on the expected level of systematic error suppression.

  6. Background by neutron activation in GERDA

    International Nuclear Information System (INIS)

    The observation of the neutrinoless double beta decay is a proof of the Majorana nature of the neutrino. The long half-life of this decay requires experiments of very low background rates in the region of interest at Qββ. Prompt γ-rays after neutron capture on germanium and the β-decay of 77Ge contribute to the background in experiments using 76Ge for the search of the neutrinoless double beta decay. The poorly known prompt γ-ray spectra and the neutron capture cross sections for the (n,γ) reactions of 74Ge and 76Ge were measured at the research reactor FRM II (Munich). The obtained data are needed in MC simulations for qualitative and quantitative background prediction in the Gerda experiment. The data and their implication on the background in Gerda are presented.

  7. Background subtraction based on Local Shape

    CERN Document Server

    Jodoin, Jean-Philippe; Saunier, Nicolas

    2012-01-01

    We present a novel approach to background subtraction that is based on the local shape of small image regions. In our approach, an image region centered on a pixel is mod-eled using the local self-similarity descriptor. We aim at obtaining a reliable change detection based on local shape change in an image when foreground objects are moving. The method first builds a background model and compares the local self-similarities between the background model and the subsequent frames to distinguish background and foreground objects. Post-processing is then used to refine the boundaries of moving objects. Results show that this approach is promising as the foregrounds obtained are com-plete, although they often include shadows.

  8. The Spin-2 Equation on Minkowski Background

    CERN Document Server

    Beyer, Florian; Frauendiener, Jörg; Whale, Ben

    2014-01-01

    The linearised general conformal field equations in their first and second order form are used to study the behaviour of the spin-2 zero-rest-mass equation on Minkowski background in the vicinity of space-like infinity.

  9. Structures in the microwave background radiation

    CERN Document Server

    Meissner, K A; Ruszczycki, B

    2012-01-01

    We compare the actual WMAP maps with artificial, purely statistical maps of the same harmonic content to argue that there are, with confidence level 99.7 %, ring-type structures in the observed cosmic microwave background.

  10. Background-cross-section-dependent subgroup parameters

    International Nuclear Information System (INIS)

    A new set of subgroup parameters was derived that can reproduce the self-shielded cross section against a wide range of background cross sections. The subgroup parameters are expressed with a rational equation which numerator and denominator are expressed as the expansion series of background cross section, so that the background cross section dependence is exactly taken into account in the parameters. The advantage of the new subgroup parameters is that they can reproduce the self-shielded effect not only by group basis but also by subgroup basis. Then an adaptive method is also proposed which uses fitting procedure to evaluate the background-cross-section-dependence of the parameters. One of the simple fitting formula was able to reproduce the self-shielded subgroup cross section by less than 1% error from the precise evaluation. (author)

  11. New directions in Background Independent Quantum Gravity

    OpenAIRE

    Markopoulou, Fotini

    2007-01-01

    We discuss the meaning of background independence in quantum theories of gravity where geometry and gravity are emergent and illustrate the possibilities using the framework of quantum causal histories.

  12. Exploration Blueprint: Data Book

    Science.gov (United States)

    Drake, Bret G. (Editor)

    2007-01-01

    The material contained in this report was compiled to capture the work performed by the National Aeronautics and Space Administration's (NASA's) Exploration study team in the late 2002 timeframe. The "Exploration Blueprint Data Book" documents the analyses and findings of the 90-day Agency-wide study conducted from September - November 2002. During the summer of 2002, the NASA Deputy Administrator requested that a study be performed with the following objectives: (1) Develop the rationale for exploration beyond low-Earth orbit (2) Develop roadmaps for how to accomplish the first steps through humans to Mars (3) Develop design reference missions as a basis for the roadmaps 4) Make recommendations on what can be done now to effect this future This planning team, termed the Exploration Blueprint, performed architecture analyses to develop roadmaps for how to accomplish the first steps beyond LEO through the human exploration of Mars. The previous NASA Exploration Team activities laid the foundation and framework for development of NASA's Integrated Space Plan. The reference missions resulting from the analysis performed by the Exploration Blueprint team formed the basis for requirement definition, systems development, technology roadmapping, and risk assessments for future human exploration beyond low-Earth orbit. Emphasis was placed on developing recommendations on what could be done now to effect future exploration activities. The Exploration Blueprint team embraced the "Stepping Stone" approach to exploration where human and robotic activities are conducted through progressive expansion outward beyond low-Earth orbit. Results from this study produced a long-term strategy for exploration with near-term implementation plans, program recommendations, and technology investments. Specific results included the development of a common exploration crew vehicle concept, a unified space nuclear strategy, focused bioastronautics research objectives, and an integrated human

  13. Background dose subtraction in personnel dosimetry

    International Nuclear Information System (INIS)

    In this paper it is proposed to consider the mode of the frequency distribution of the low dose dosemeters from each clinic that uses X rays as the background environmental dose that should be subtracted from the personnel dosimetry to evaluate the doses due to practice. The problems and advantages of this indirect method to estimate the environmental background dose are discussed. The results for 60 towns are presented. (author)

  14. Cosmic Coincidences: Investigations for Neutron Background Suppression

    OpenAIRE

    Heimbach, Craig R.

    2007-01-01

    Two experimental investigations were made in order to reduce background counts in neutron detectors. Each investigation relied upon the fact that neutron background is largely due to cosmic ray interactions with the air and ground. The first attempt was to look at neutron arrival times. Neutron events close in time were taken to have been of a common origin due to cosmic rays. The second investigation was similar, but based on coincident neutron/muon events. The investigations showed only a s...

  15. Supermembrane actions for Gaiotto–Maldacena backgrounds

    International Nuclear Information System (INIS)

    We write down the supermembrane actions for M-theory backgrounds dual to general N=2 four-dimensional superconformal field theories. The actions are given to all orders in fermions and are in a particular κ-gauge. When an extra U(1) isometry is present, our actions reduce to κ-gauge fixed Green–Schwarz actions for the corresponding Type IIA backgrounds

  16. Supermembrane actions for Gaiotto–Maldacena backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Stefański, Bogdan, E-mail: Bogdan.Stefanski.1@city.ac.uk

    2014-06-15

    We write down the supermembrane actions for M-theory backgrounds dual to general N=2 four-dimensional superconformal field theories. The actions are given to all orders in fermions and are in a particular κ-gauge. When an extra U(1) isometry is present, our actions reduce to κ-gauge fixed Green–Schwarz actions for the corresponding Type IIA backgrounds.

  17. Supermembrane actions for Gaiotto-Maldacena backgrounds

    Science.gov (United States)

    Stefański, Bogdan

    2014-06-01

    We write down the supermembrane actions for M-theory backgrounds dual to general N=2 four-dimensional superconformal field theories. The actions are given to all orders in fermions and are in a particular κ-gauge. When an extra U(1) isometry is present, our actions reduce to κ-gauge fixed Green-Schwarz actions for the corresponding Type IIA backgrounds.

  18. CORSIKA modifications for faster background generation

    Science.gov (United States)

    Jero, Kyle

    2016-04-01

    CORSIKA is a simulation program for extensive air showers initiated by high energy cosmic particles. These air showers create the majority of the muons and neutrinos which neutrino that telescopes detect and are considered a background signature in searches for astrophysical neutrinos. This contribution will discuss changes to CORSIKA which allow for faster high energy background simulation. The theory, implementation, application, and performance of these modifications will be presented.

  19. Moving object detection using background subtraction

    CERN Document Server

    Shaikh, Soharab Hossain; Chaki, Nabendu

    2014-01-01

    This Springer Brief presents a comprehensive survey of the existing methodologies of background subtraction methods. It presents a framework for quantitative performance evaluation of different approaches and summarizes the public databases available for research purposes. This well-known methodology has applications in moving object detection from video captured with a stationery camera, separating foreground and background objects and object classification and recognition. The authors identify common challenges faced by researchers including gradual or sudden illumination change, dynamic bac

  20. Interferometric Observation of Cosmic Microwave Background Anisotropies

    CERN Document Server

    White, M; Dragovan, M; White, Martin; Carlstrom, John E.; Dragovan, Mark

    1999-01-01

    We present a formalism for analyzing interferometric observations of Cosmic Microwave Background (CMB) anisotropy and polarization data. The formalism is based upon the ell-space expansion of the angular power spectrum favoured in recent years. Explicit discussions of maximum likelihood analysis, power spectrum reconstruction, parameter estimation, imaging and polarization are given. As an example, several calculations for the Degree Angular Scale Interferometer (DASI) and Cosmic Background Interferometer (CBI) experiments are presented.

  1. The pregalactic cosmic gravitational wave background

    Science.gov (United States)

    Matzner, Richard A.

    1989-01-01

    An outline is given that estimates the expected gravitational wave background, based on plausible pregalactic sources. Some cosmologically significant limits can be put on incoherent gravitational wave background arising from pregalactic cosmic evolution. The spectral region of cosmically generated and cosmically limited radiation is, at long periods, P greater than 1 year, in contrast to more recent cosmological sources, which have P approx. 10 to 10(exp -3).

  2. The pregalactic cosmic gravitational wave background

    International Nuclear Information System (INIS)

    An outline is given that estimates the expected gravitational wave background, based on plausible pregalactic sources. Some cosmologically significant limits can be put on incoherent gravitational wave background arising from pregalactic cosmic evolution. The spectral region of cosmically generated and cosmically limited radiation is, at long periods, P greater than 1 year, in contrast to more recent cosmological sources, which have P approx. 10 to 10(exp -3)

  3. Blank Background Image Lossless Compression Technique

    OpenAIRE

    Samer Sawalha; Arafat Awajan

    2014-01-01

    This paper presents a new technique able to provide a very good compression ratio in preserving the quality of the important components of the image called main objects. It focuses on applications where the image is of large size and consists of an object or a set of objects on background such as identity photos. In these applications, the background of the objects is in general uniform and represents insignificant information for the application. The results of this new techniques show that ...

  4. Gravitational wave background from binary systems

    International Nuclear Information System (INIS)

    Basic aspects of the background of gravitational waves and its mathematical characterization are reviewed. The spectral energy density parameter Ω(f), commonly used as a quantifier of the background, is derived for an ensemble of many identical sources emitting at different times and locations. For such an ensemble, Ω(f) is generalized to account for the duration of the signals and of the observation, so that one can distinguish the resolvable and unresolvable parts of the background. The unresolvable part, often called confusion noise or stochastic background, is made by signals that cannot be either individually identified or subtracted out of the data. To account for the resolvability of the background, the overlap function is introduced. This function is a generalization of the duty cycle, which has been commonly used in the literature, in some cases leading to incorrect results. The spectra produced by binary systems (stellar binaries and massive black hole binaries) are presented over the frequencies of all existing and planned detectors. A semi-analytical formula for Ω(f) is derived in the case of stellar binaries (containing white dwarfs, neutron stars or stellar-mass black holes). Besides a realistic expectation of the level of background, upper and lower limits are given, to account for the uncertainties in some astrophysical parameters such as binary coalescence rates. One interesting result concerns all current and planned ground-based detectors (including the Einstein Telescope). In their frequency range, the background of binaries is resolvable and only sporadically present. In other words, there is no stochastic background of binaries for ground-based detectors.

  5. Mathematical Background of Public Key Cryptography

    DEFF Research Database (Denmark)

    Frey, Gerhard; Lange, Tanja

    2005-01-01

    The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material.......The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material....

  6. Cross correlations of the cosmic infrared background

    OpenAIRE

    Zhang, Pengjie

    2003-01-01

    The cosmic infrared background (CIB) is a sensitive measure of the star formation history. But this background is overwhelmed by foregrounds, which bias the CIB mean flux and auto correlation measurement severely. Since dominant foregrounds do not correlate with the large scale structure, the cross correlation of CIB with galaxies is free of such foregrounds and presents as an unbiased measure of the star formation history. This also allows the measurement of CIB based on integrated intensity...

  7. International exploration by independent

    International Nuclear Information System (INIS)

    Recent industry trends indicate that the smaller U.S. independents are looking at foreign exploration opportunities as one of the alternatives for growth in the new age of exploration. Foreign finding costs per barrel usually are accepted to be substantially lower than domestic costs because of the large reserve potential of international plays. To get involved in overseas exploration, however, requires the explorationist to adapt to different cultural, financial, legal, operational, and political conditions. Generally, foreign exploration proceeds at a slower pace than domestic exploration because concessions are granted by a country's government, or are explored in partnership with a national oil company. First, the explorationist must prepare a mid- to long-term strategy, tailored to the goals and the financial capabilities of the company; next, is an ongoing evaluation of quality prospects in various sedimentary basins, and careful planning and conduct of the operations. To successfully explore overseas also requires the presence of a minimum number of explorationists and engineers thoroughly familiar with the various exploratory and operational aspects of foreign work. Ideally, these team members will have had a considerable amount of on-site experience in various countries and climates. Independents best suited for foreign expansion are those who have been financially successful in domestic exploration. When properly approached, foreign exploration is well within the reach of smaller U.S. independents, and presents essentially no greater risk than domestic exploration; however, the reward can be much larger and can catapult the company into the 'big leagues.'

  8. Background characterization for the GERDA experiment

    International Nuclear Information System (INIS)

    The GERmanium Detector Array (Gerda) experiment at the LNGS laboratory of INFN searches for the neutrinoless double beta (0νββ) decay of 76Ge. A discovery of this decay can greatly advance our knowledge on the nature and properties of neutrinos. The current best limit on the half-life of 76Ge 0νββ decay is 1.9 . 1025 years (90% C.L.). In order to increase the sensitivity on the half-life with respect to past experiments, the background rate in the energy region of interest (ROI) around Qββ = 2039 keV has been reduced by a factor 10. Gerda started data-taking with the full set of Phase I detectors in November 2011. Identification of the background in the first phase of the experiment is of major importance to further mitigate the background for Gerda Phase II. An analysis of the Phase I data resulted in a good understanding of the individual components in the Gerda background spectrum. The background components in the ROI have been identified to be mainly due to β- and γ-induced events originating from 214Bi (238U-series), 208Tl (232Th-series), 42K (progeny of 42Ar) and α-induced events coming from isotopes in the 226Ra decay chain. A background decomposition in the ROI will be presented, with a special emphasis on the contribution from α-induced events.

  9. Holographic Thermalization in Quark Confining Background

    CERN Document Server

    Ageev, D S

    2014-01-01

    We study holographic thermalization of a strongly coupled theory inspired by two colliding shock waves in a vacuum confining background. Holographic thermalization means a black hole formation, in fact a trapped surface formation. As a vacuum confining background we considered a well know bottom-up AdS/QCD model that provides the Cornell potential as well as reproduces QCD beta-function. We perturb vacuum background by colliding domain shock waves, that are assumed to be holographically dual to heavy ions collisions. Our main physical assumption is that we can make a restriction on the time of a trapped surface production that makes a natural limitation on the size of the domain where the trapped surface is produced. This limits the intermediate domain where the main part of the entropy is produced. In this domain one can use an intermediate vacuum background as an approximation to the full confining background. In this intermediate background a dependence of the produced entropy on colliding energy is very s...

  10. String pair production in non homogeneous backgrounds

    CERN Document Server

    Bolognesi, Stefano; Tallarita, Gianni

    2016-01-01

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is les...

  11. Low background screening capability in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Ghag, Chamkaur [University College London, Department of Physics and Astronomy, Gower Street, London WC1E 6BT (United Kingdom)

    2015-08-17

    Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment.

  12. Simbol-X background simulation activities

    CERN Document Server

    Chipaux, Rémi; Bulgarelli, A; Foschini, L; Kendziorra, E; Klose, C; Kuster, M; Laurent, P; Tenzer, C

    2008-01-01

    Using the Geant4 toolkit, a Monte-Carlo code to simulate the detector background of the Simbol-X focal plane instrument has been developed with the aim to optimize the design of the instrument. Structural design models of the mirror and detector satellites have been built and used as baseline for our simulations, to evaluate the different background contributions that must be taken into account to determine the sensitivity of the Simbol-X detectors. We work towards a simulation based background and mass model which can be used before and during the mission. For different material compositions, material thicknesses, locations etc. the response of the instrument to the diffuse cosmic hard X-ray background and to the cosmic proton induced background have been calculated. As a result we present estimates of the background count rate expected in the low and high energy detector, and anti-coincidence rates. The effect of induced radioactivity in the detector and shielding materials and soft proton scattering in the...

  13. Background Modelling Using Edge-Segment Distributions

    Directory of Open Access Journals (Sweden)

    Jaemyun Kim

    2013-02-01

    Full Text Available We propose an edge‐segment‐based statistical background modelling algorithm to detect the moving edges for the detection of moving objects using a static camera. Traditional pixel intensity‐based background modelling algorithms face difficulties in dynamic environments since they cannot handle sudden changes in illumination. They also bring out ghosts when a sudden change occurs in the scene. To cope with this issue, intensity and noise robust edge‐based features have emerged. However, existing edge‐pixel‐based methods suffer from scattered moving edge pixels since they cannot utilize the shape. Moreover, traditional segment‐ based methods cannot handle edge shape variations and miss moving edges when they come close to the background edges. Unlike traditional approaches, our proposed method builds the background model from ordinary training frames that may contain moving objects. Furthermore, it does not leave any ghosts behind. Moreover, our method uses an automatic threshold for every background edge distribution for matching. This makes our approach robust to illumination change, camera movement and background motion. Experiments show that our method outperforms others and can detect moving edges efficiently despite the above mentioned difficulties.

  14. Background Assay and Rejection in DRIFT

    CERN Document Server

    Brack, Jeff; Dorofeev, Alexei; Ezeribe, Anthony; Gauvreau, Jean-Luc; Gold, Michael; Harton, John; Lafler, Randy; Lauer, Robert; Lee, Eric R; Loomba, Dinesh; Matthews, John; Miller, Eric H; Monte, Alissa; Murphy, Alex; Paling, Sean; Phan, Nguyen; Sadler, Steve; Scarff, Andrew; Snowden-Ifft, Daniel; Spooner, Neil; Telfer, Sam; Walker, Daniel; Williams, Matt; Yuriev, Leonid

    2014-01-01

    The DRIFT-IId dark matter detector is a m$^3$-scale low-pressure TPC with directional sensitivity to WIMP-induced nuclear recoils. Its primary backgrounds were due to alpha decays from contamination on the central cathode. Efforts to reduce these backgrounds led to replacing the 20 \\mu m wire central cathode with one constructed from 0.9 \\mu m aluminized mylar, which is almost totally transparent to alpha particles. Detailed modeling of the nature and origin of the remaining backgrounds led to an in-situ, ppt-sensitive assay of alpha decay backgrounds from the central cathode. This led to further improvements in the thin-film cathode resulting in over 2 orders of magnitude reduction in backgrounds compared to the wire cathode. Finally, the addition of O$_2$ to CS$_2$ gas was found to produce multiple species of electronegative charge carriers, providing a method to determine the absolute position of nuclear recoils and reject all known remaining backgrounds while retaining a high efficiency for nuclear recoil...

  15. Low background screening capability in the UK

    International Nuclear Information System (INIS)

    Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment

  16. Low background screening capability in the UK

    Science.gov (United States)

    Ghag, Chamkaur

    2015-08-01

    Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment.

  17. Geochemical exploration for uranium

    International Nuclear Information System (INIS)

    This Technical Report is designed mainly to introduce the methods and techniques of uranium geochemical exploration to exploration geologists who may not have had experience with geochemical exploration methods in their uranium programmes. The methods presented have been widely used in the uranium exploration industry for more than two decades. The intention has not been to produce an exhaustive, detailed manual, although detailed instructions are given for a field and laboratory data recording scheme and a satisfactory analytical method for the geochemical determination of uranium. Rather, the intention has been to introduce the concepts and methods of uranium exploration geochemistry in sufficient detail to guide the user in their effective use. Readers are advised to consult general references on geochemical exploration to increase their understanding of geochemical techniques for uranium

  18. Visual explorer facilitator's guide

    CERN Document Server

    Palus, Charles J

    2010-01-01

    Grounded in research and practice, the Visual Explorer™ Facilitator's Guide provides a method for supporting collaborative, creative conversations about complex issues through the power of images. The guide is available as a component in the Visual Explorer Facilitator's Letter-sized Set, Visual Explorer Facilitator's Post card-sized Set, Visual Explorer Playing Card-sized Set, and is also available as a stand-alone title for purchase to assist multiple tool users in an organization.

  19. The background in the experiment Gerda

    Science.gov (United States)

    Agostini, M.; Allardt, M.; Andreotti, E.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Barnabé Heider, M.; Barros, N.; Baudis, L.; Bauer, C.; Becerici-Schmidt, N.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Brudanin, V.; Brugnera, R.; Budjáš, D.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; Cossavella, F.; Demidova, E. V.; Domula, A.; Egorov, V.; Falkenstein, R.; Ferella, A.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gotti, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Guthikonda, K. K.; Hampel, W.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Klimenko, A.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Liu, X.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Machado, A. A.; Majorovits, B.; Maneschg, W.; Nemchenok, I.; Nisi, S.; O'Shaughnessy, C.; Palioselitis, D.; Pandola, L.; Pelczar, K.; Pessina, G.; Pullia, A.; Riboldi, S.; Sada, C.; Salathe, M.; Schmitt, C.; Schreiner, J.; Schulz, O.; Schwingenheuer, B.; Schönert, S.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Strecker, H.; Tarka, M.; Ur, C. A.; Vasenko, A. A.; Volynets, O.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wojcik, M.; Yanovich, E.; Zavarise, P.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

    2014-04-01

    The GERmanium Detector Array ( Gerda) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta () decay of Ge. The signature of the signal is a monoenergetic peak at 2039 keV, the value of the decay. To avoid bias in the signal search, the present analysis does not consider all those events, that fall in a 40 keV wide region centered around . The main parameters needed for the analysis are described. A background model was developed to describe the observed energy spectrum. The model contains several contributions, that are expected on the basis of material screening or that are established by the observation of characteristic structures in the energy spectrum. The model predicts a flat energy spectrum for the blinding window around with a background index ranging from 17.6 to 23.8 cts/(keV kg yr). A part of the data not considered before has been used to test if the predictions of the background model are consistent. The observed number of events in this energy region is consistent with the background model. The background at is dominated by close sources, mainly due to K, Bi, Th, Co and emitting isotopes from the Ra decay chain. The individual fractions depend on the assumed locations of the contaminants. It is shown, that after removal of the known peaks, the energy spectrum can be fitted in an energy range of 200 keV around with a constant background. This gives a background index consistent with the full model and uncertainties of the same size.

  20. Automated FingerPrint Background removal: FPB

    Directory of Open Access Journals (Sweden)

    Morgante Michele

    2009-04-01

    Full Text Available Abstract Background The construction of a whole-genome physical map has been an essential component of numerous genome projects initiated since the inception of the Human Genome Project. Its usefulness has been proved for whole-genome shotgun projects as a post-assembly validation and recently it has also been used in the assembly step to constrain on BACs positions. Fingerprinting is usually the method of choice for construction of physical maps. A clone fingerprint is composed of true peaks representing real fragments and background peaks, mainly composed of E. coli genomic DNA, partial digestions, star activity by-products, and machine background. High-throughput fingerprinting leads to the production of thousands of BAC clone fingerprints per day. That is why background peaks removal has become an important issue and needs to be automatized, especially in capillary electrophoresis based fingerprints. Results At the moment, the only tools available for such a task are GenoProfiler and its descendant FPMiner. The large variation in the quality of fingerprints that is usually present in large fingerprinting projects represents a major difficulty in the correct removal of background peaks that has only been partially addressed by the methods so far adopted that all require a long manual optimization of parameters. Thus, we implemented a new data-independent tool, FPB (FingerPrint Background removal, suitable for large scale projects as well as mapping of few clones. Conclusion FPB is freely available at http://www.appliedgenomics.org/tools.php. FPB was used to remove the background from all fingerprints of three grapevine physical map projects. The first project consists of about 50,000 fingerprints, the second one consists of about 70,000 fingerprints, and the third one consists of about 45,000 fingerprints. In all cases a successful assembly was built.

  1. Can one measure the Cosmic Neutrino Background?

    CERN Document Server

    Faessler, Amand; Kovalenko, Sergey; Simkovic, Fedor

    2016-01-01

    The Cosmic Microwave Background (CMB) yields information about our Universe at around 380 000 years after the Big Bang (BB). Due to the weak interaction of the neutrinos with matter the Cosmic Neutrino Background (CNB) should give information about a much earlier time of our Universe, around one second after the Big Bang. Probably the most promising method to `see' the Cosmic Neutrino Background is the capture of the electron neutrinos from the Background by Tritium, which then decays into 3He and an electron with the energy of the the Q-value = 18.562 keV plus the electron neutrino rest mass. The `KArlsruhe TRItium Neutrino' (KATRIN) experiment, which is in preparation, seems presently the most sensitive proposed method for measuring the electron antineutrino mass. At the same time KATRIN can also look by the reaction: electron neutrino (~1.95 Kelvin) + 3H --> 3He + e- (with the energy Q = 18.6 keV + electron neutrino mass). The capture of the Cosmic Background Neutrinos (CNB) should show in the electron spe...

  2. Infrared Background and Missiles Signature Survey

    Directory of Open Access Journals (Sweden)

    D.V. Renuka

    2013-12-01

    Full Text Available The proliferation of the missile threats in the existing threat scenario for airborne platform is a serious point of consideration for any mission planning. Missile warning system is an electronic warfare support system which gives warning to the pilot when a missile is detected in the scenario. The airborne platform has to be installed with missile warning sensors to give a spherical coverage, so that the sensors can detect the IR intensity variation in the ground scenario. This IR intensity variation has to be further analysed to differentiate the raising missile intensity from the varying background clutter. In order to differentiate the threat from the background clutter, the system should have sufficient background data set for online comparison thereby having less false alarm rate. The efficiency and performance of any missile warning system is validated with respect to its probability of declaration against the false alarm rate. Hence, to realize an efficient functioning of missile warning system, building IR background data base and missile signature database are the primary task. This paper details the methodology to be adapted for the building of tactical missile IR signatures and background data.Defence Science Journal, 2013, 63(6, pp.611-615, DOI:http://dx.doi.org/10.14429/dsj.63.5762

  3. Infrared Background and Missiles Signature Survey

    Directory of Open Access Journals (Sweden)

    D.V. Renuka

    2013-11-01

    Full Text Available The proliferation of the missile threats in the existing threat scenario for airborne platform is a serious point of consideration for any mission planning. Missile warning system is an electronic warfare support system which gives warning to the pilot when a missile is detected in the scenario. The airborne platform has to be installed with missile warning sensors to give a spherical coverage, so that the sensors can detect the IR intensity variation in the ground scenario. This IR intensity variation has to be further analysed to differentiate the raising missile intensity from the varying background clutter. In order to differentiate the threat from the background clutter, the system should have sufficient background data set for online comparison thereby having less false alarm rate. The efficiency and performance of any missile warning system is validated with respect to its probability of declaration against the false alarm rate. Hence, to realize an efficient functioning of missile warning system, building IR background data base and missile signature database are the primary task. This paper details the methodology to be adapted for the building of tactical missile IR signatures and background data.

  4. Alpha Background Rejection in Bolometer Detectors

    Science.gov (United States)

    Deporzio, Nicholas; Cuore Collaboration

    This study presents the modification of bolometer detectors used in particle searches to veto or otherwise reject alpha radiation background and the statistical advantages of doing so. Several techniques are presented in detail - plastic film scintillator vetoes, metallic film ionization vetoes, and Cherenkov radiation vetoes. Plastic scintillator films are cooled to bolometer temperatures and bombarded with 1.4MeV to 6.0MeV alpha particles representative of documented detector background. Quantum dot based liquid scintillator is similarly bombarded to produce a background induced scintillation light. Photomultipliers detect this scintillation light and produce a veto signal. Layered metallic films of a primary metal, dielectric, and secondary metal, such as gold-polyethylene-gold films, are cooled to milli-kelvin temperatures and biased to produce a current signal veto when incident 1.4MeV to 6.0MeV alpha particles ionize conduction paths through the film. Calibration of veto signal to background energy is presented. These findings are extrapolated to quantify the statistical impact of such modifications to bolometer searches. Effects of these techniques on experiment duration and signal-background ratio are discussed.

  5. Background reduction in the SNO+ experiment

    Science.gov (United States)

    Segui, L.

    2015-08-01

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of 130Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with 130Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier's. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 102 -103 in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  6. Holographic backgrounds from D-brane probes

    CERN Document Server

    Moskovic, Micha

    2014-01-01

    This thesis focuses on the derivation of holographic backgrounds from the field theory side, without using any supergravity equations of motion. Instead, we rely on the addition of probe D-branes to the stack of D-branes generating the background. From the field theory description of the probe branes, one can compute an effective action for the probes (in a suitable low-energy/near-horizon limit) by integrating out the background branes. Comparing this action with the generic probe D-brane action then allows to determine the holographic background dual to the considered field theory vacuum. In the first part, the required pre-requisites of field and string theory are recalled and this strategy to derive holographic backgrounds is explained in more detail on the basic case of D3-branes in flat space probed by a small number of D-instantons. The second part contains our original results, which have already appeared in arXiv:1301.3738, arXiv:1301.7062 and arXiv:1312.0621. We first derive the duals to three conti...

  7. Gravitational wave background from reheating after hybrid inflation

    International Nuclear Information System (INIS)

    The reheating of the Universe after hybrid inflation proceeds through the nucleation and subsequent collision of large concentrations of energy density in the form of bubblelike structures moving at relativistic speeds. This generates a significant fraction of energy in the form of a stochastic background of gravitational waves, whose time evolution is determined by the successive stages of reheating: First, tachyonic preheating makes the amplitude of gravity waves grow exponentially fast. Second, bubble collisions add a new burst of gravitational radiation. Third, turbulent motions finally sets the end of gravitational waves production. From then on, these waves propagate unimpeded to us. We find that the fraction of energy density today in these primordial gravitational waves could be significant for grand unified theory (GUT)-scale models of inflation, although well beyond the frequency range sensitivity of gravitational wave observatories like LIGO, LISA, or BBO. However, low-scale models could still produce a detectable signal at frequencies accessible to BBO or DECIGO. For comparison, we have also computed the analogous gravitational wave background from some chaotic inflation models and obtained results similar to those found by other groups. The discovery of such a background would open a new observational window into the very early universe, where the details of the process of reheating, i.e. the big bang, could be explored. Moreover, it could also serve in the future as a new experimental tool for testing the inflationary paradigm

  8. A novel approach to model EPIC variable background

    Science.gov (United States)

    Marelli, M.; De Luca, A.; Salvetti, D.; Belfiore, A.; Pizzocaro, D.

    2016-06-01

    In the past years XMM-Newton revolutionized our way to look at the X-ray sky. With more than 200 Ms of exposure, it allowed for numerous discoveries in every field of astronomy. Unfortunately, about 35% of the observing time is badly affected by soft proton flares, with background increasing by orders of magnitudes hampering any classical analysis of field sources. One of the main aim of the EXTraS (“Exploring the X-ray Transient and variable Sky”) project is to characterise the variability of XMM-Newton sources within each single observation, including periods of high background. This posed severe challenges. I will describe a novel approach that we implemented within the EXTraS project to produce background-subtracted light curves, that allows to treat the case of very faint sources and very large proton flares. EXTraS light curves will be soon released to the community, together with new tools that will allow the user to reproduce EXTraS results, as well as to extend a similar analysis to future data. Results of this work (including an unprecedented characterisation of the soft proton phenomenon and instrument response) will also serve as a reference for future missions and will be particularly relevant for the Athena observatory.

  9. The exploration metaphor

    Science.gov (United States)

    Mcgreevy, Michael W.

    1991-01-01

    NASA's experience in planetary exploration has demonstrated that the desktop workstation is inadequate for many visualization situations. The primary mission displays for the unmanned Surveyor missions to the moon during the mid-1960's, for example, were environmental images assembled on the inside surfaces of spherical shells. Future exploration missions will greatly benefit from advances in digital computer and display technology, but there remain unmet user interface needs. Alternative user interfaces and metaphors are needed for planetary exploration and other interactions with complex spatial environments. These interfaces and metaphors would enable the user to directly explore environments and naturally manipulate objects in those environments. Personal simulators, virtual workstations, and telepresence user interfaces are systems capable of providing this integration of user space and task space. The Exploration Metaphor is a useful concept for guiding the design of user interfaces for virtual environments and telepresence. To apply the Exploration Metaphor is to assert that computing is like exploration, and to support objects, operations, and contexts comparable to those encountered in the exploration of natural environments. The Exploration Metaphor, under development for user interfaces in support of NASA's planetary exploration missions and goals, will also benefit other applications where complex spatial information must be visualized. Visualization methods and systems for planetary exploration are becoming increasingly integrated and interactive as computing technology improves. These advances will benefit from virtual environment and telepresence interface technology. A key development has been the processing of multiple images and other sensor data to create detailed digital models of the planets and moons. Data from images of the Earth, Mars, and Miranda, for example, have been converted into 3D models, and dynamic virtual fly-overs have been

  10. Tidal Forces in Naked Singularity Backgrounds

    CERN Document Server

    Goel, Akash; Roy, Pratim; Sarkar, Tapobrata

    2015-01-01

    The end stage of a gravitational collapse process can generically result in a black hole or a naked singularity. Here we undertake a comparative analysis of the nature of tidal forces in these backgrounds. The effect of such forces is generically exemplified by the Roche limit, which predicts the distance within which a celestial object disintegrates due to the tidal effects of a second more massive object. In this paper, using Fermi normal coordinates, we numerically compute the Roche limit for a class of non-rotating naked singularity backgrounds, and compare them with known results for Schwarzschild black holes. Our analysis indicates that there might be substantially large deviations in the magnitudes of tidal forces in naked singularity backgrounds, compared to the black hole cases. If observationally established, these can prove to be an effective indicator of the nature of the singularity at a galactic centre.

  11. Neutrino refraction by the cosmic neutrino background

    CERN Document Server

    Diaz, J S

    2015-01-01

    We have determined the dispersion relation of a neutrino test particle propagating in the cosmic neutrino background. Describing the relic neutrinos and antineutrinos from the hot big bang as a dense medium, a matter potential or refractive index is obtained. The vacuum neutrino mixing angles are unchanged, but the energy of each mass state is modified. Using a matrix in the space of neutrino species, the induced potential is decomposed into a part which produces signatures in beta-decay experiments and another part which modifies neutrino oscillations. The low temperature of the relic neutrinos makes a direct detection extremely challenging. From a different point of view, the identified refractive effects of the cosmic neutrino background constitute an ultralow background for future experimental studies of nonvanishing Lorentz violation in the neutrino sector.

  12. Background modeling for the GERDA experiment

    Science.gov (United States)

    Becerici-Schmidt, N.; Gerda Collaboration

    2013-08-01

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Qββ come from 214Bi, 228Th, 42K, 60Co and α emitting isotopes in the 226Ra decay chain, with a fraction depending on the assumed source positions.

  13. Background modeling for the GERDA experiment

    International Nuclear Information System (INIS)

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Qββ come from 214Bi, 228Th, 42K, 60Co and α emitting isotopes in the 226Ra decay chain, with a fraction depending on the assumed source positions

  14. Background modeling for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Becerici-Schmidt, N. [Max-Planck-Institut für Physik, München (Germany); Collaboration: GERDA Collaboration

    2013-08-08

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Q{sub ββ} come from {sup 214}Bi, {sup 228}Th, {sup 42}K, {sup 60}Co and α emitting isotopes in the {sup 226}Ra decay chain, with a fraction depending on the assumed source positions.

  15. Background modeling for the GERDA experiment

    CERN Document Server

    Becerici-Schmidt, N

    2013-01-01

    The neutrinoless double beta (0nubb) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0nubb decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Qbb come from Bi-214, Th-228, K-42, Co-60 and alpha emitting isotopes in the Ra-226 decay chain, with a fraction depending on the assumed source positions.

  16. Background Model for the Majorana Demonstrator

    CERN Document Server

    Cuesta, C; Aguayo, E; Avignone, F T; Barabash, A S; Bertrand, F E; Boswell, M; Brudanin, V; Busch, M; Byram, D; Caldwell, A S; Chan, Y-D; Christofferson, C D; Combs, D C; Cuesta, C; Detwiler, J A; Doe, P J; Efremenko, Yu; Egorov, V; Ejiri, H; Elliott, S R; Fast, J E; Finnerty, P; Fraenkle, F M; Galindo-Uribarri, A; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guiseppe, V E; Gusev, K; Hallin, A L; Hazama, R; Hegai, A; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Keeter, K J; Kidd, M F; Kochetov, O; Konovalov, S I; Kouzes, R T; LaFerriere, B D; Leon, J; Leviner, L E; Loach, J C; MacMullin, J; MacMullin, S; Martin, R D; Meijer, S; Mertens, S; Nomachi, M; Orrell, J L; O'Shaughnessy, C; Overman, N R; Phillips, D G; Poon, A W P; Pushkin, K; Radford, D C; Rager, J; Rielage, K; Robertson, R G H; Romero-Romero, E; Ronquest, M C; Schubert, A G; Shanks, B; Shima, T; Shirchenko, M; Snavely, K J; Snyder, N; Suriano, A M; Thompson, J; Timkin, V; Tornow, W; Trimble, J E; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Wiseman, C; Xu, W; Yakushev, E; Young, A R; Yu, C H; Yumatov, V

    2014-01-01

    The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements.

  17. The Future of Microwave Background Physics

    CERN Document Server

    Kosowsky, A

    2003-01-01

    The cosmic microwave background is now fulfilling its promise of determining the basic cosmological parameters describing our Universe. Future study of the microwave background will mostly be directed towards two basic questions: a complete characterization of the initial perturbations, and probes of the nonlinear evolution of structure in the Universe. The basic scientific issues in both of these areas are reviewed here, along with possibilities for addressing them with further microwave background measurements at higher sensitivities and smaller angular scales. The proposed ACT experiment, which will map 200 square degrees of sky at arcminute resolution and micro-Kelvin sensitivity in three microwave frequency bands, is briefly described as an example of rapidly advancing experimental technique.

  18. Neutrino refraction by the cosmic neutrino background

    Science.gov (United States)

    Díaz, J. S.; Klinkhamer, F. R.

    2016-03-01

    We have determined the dispersion relation of a neutrino test particle propagating in the cosmic neutrino background. Describing the relic neutrinos and antineutrinos from the hot big bang as a dense medium, a matter potential or refractive index is obtained. The vacuum neutrino mixing angles are unchanged, but the energy of each mass state is modified. Using a matrix in the space of neutrino species, the induced potential is decomposed into a part which produces signatures in beta-decay experiments and another part which modifies neutrino oscillations. The low temperature of the relic neutrinos makes a direct detection extremely challenging. From a different point of view, the identified refractive effects of the cosmic neutrino background constitute an ultralow background for future experimental studies of nonvanishing Lorentz violation in the neutrino sector.

  19. Pythia Jet Finding Study with Trento Backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Joseph [United States Naval Academy, Annapolis, MD (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soltz, Ron [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-06-22

    We present results applying the Pythia SlowJet Finder to Pythia generated QCD and QED hard processes in the presence of simulated heavy ion backgrounds. The hard process events are generated with Pythia version 8.219 for √sNN=200 GeV proton-proton collisions and the backgrounds are generated by the Reduced Thickness Event-by-event Nuclear Topology model TRENTo for Au-Au collisions with a nucleon-nucleon cross-section of 4.23 fm2. The TRENTo model is used to calculate the initial entropy and ellipticity from which the total charged particle multiplicity and elliptic ow are determined. We report results in the form of event displays, total pT distributions, and fragmentation distributions for SlowJet applied to Pythia events with and without the simulated heavy ion backgrounds.

  20. In-Beam Background Suppression Shield

    CERN Document Server

    Santoro, V; DiJulio, D D; Ansell, S; Bentley, P M

    2015-01-01

    The long (3ms) proton pulse of the European Spallation Source (ESS) gives rise to unique and potentially high backgrounds for the instrument suite. In such a source an instrument capabilities will be limited by it's Signal to Noise (S/N) ratio. The instruments with a direct view of the moderator, which do not use a bender to help mitigate the fast neutron background, are the most challenging. For these beam lines we propose the innovative shielding of placing blocks of material directly into the guide system, which allow a minimum attenuation of the cold and thermal fluxes relative to the background suppression. This shielding configuration has been worked into a beam line model using Geant4. We study particularly the advantages of single crystal sapphire and silicon blocks .

  1. Non-perturbative background field calculations

    International Nuclear Information System (INIS)

    New methods are developed for calculating one loop functional determinants in quantum field theory. Instead of relying on a calculation of all the eigenvalues of the small fluctuation equation, these techniques exploit the ability of the proper time formalism to reformulate an infinite dimensional field theoretic problem into a finite dimensional covariant quantum mechanical analog, thereby allowing powerful tools such as the method of Jacobi fields to be used advantageously in a field theory setting. More generally the methods developed herein should be extremely valuable when calculating quantum processes in non-constant background fields, offering a utilitarian alternative to the two standard methods of calculation: perturbation theory in the background field or taking the background field into account exactly. The formalism developed also allows for the approximate calculation of covariances of partial differential equations from a knowledge of the solutions of a homogeneous ordinary differential equation. copyright 1988 Academic Press, Inc

  2. Modelling background intensity in Affymetrix Genechips

    CERN Document Server

    Kroll, K M; Carlon, E

    2008-01-01

    DNA microarrays are devices that are able, in principle, to detect and quantify the presence of specific nucleic acid sequences in complex biological mixtures. The measurement consists in detecting fluorescence signals from several spots on the microarray surface onto which different probe sequences are grafted. One of the problems of the data analysis is that the signal contains a noisy background component due to non-specific binding. This paper presents a physical model for background estimation in Affymetrix Genechips. It combines two different approaches. The first is based on the sequence composition, specifically its sequence dependent hybridization affinity. The second is based on the strong correlation of intensities from locations which are the physical neighbors of a specific spot on the chip. Both effects are incorporated in a background functional which contains 24 free parameters, fixed by minimization on a training data set. In all data analyzed the sequence specific parameters, obtained by min...

  3. Background characterization for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Becerici-Schmidt, Neslihan [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: GERDA-Collaboration

    2013-07-01

    The GERmanium Detector Array (Gerda) experiment at the LNGS laboratory of INFN searches for the neutrinoless double beta (0νββ) decay of {sup 76}Ge. A discovery of this decay can greatly advance our knowledge on the nature and properties of neutrinos. The current best limit on the half-life of {sup 76}Ge 0νββ decay is 1.9 . 10{sup 25} years (90% C.L.). In order to increase the sensitivity on the half-life with respect to past experiments, the background rate in the energy region of interest (ROI) around Q{sub ββ} = 2039 keV has been reduced by a factor 10. Gerda started data-taking with the full set of Phase I detectors in November 2011. Identification of the background in the first phase of the experiment is of major importance to further mitigate the background for Gerda Phase II. An analysis of the Phase I data resulted in a good understanding of the individual components in the Gerda background spectrum. The background components in the ROI have been identified to be mainly due to β- and γ-induced events originating from {sup 214}Bi ({sup 238}U-series), {sup 208}Tl ({sup 232}Th-series), {sup 42}K (progeny of {sup 42}Ar) and α-induced events coming from isotopes in the {sup 226}Ra decay chain. A background decomposition in the ROI will be presented, with a special emphasis on the contribution from α-induced events.

  4. Search for the Cosmic Neutrino Background

    International Nuclear Information System (INIS)

    One expects three Cosmic Backgrounds: (1) The Cosmic Microwave Background (CMB) originated 380000 years after the Big Bang (BB). (2) The Neutrino Background decoupled about one second after the BB, while (3) the Cosmic Gravitational Wave Background created by the inflationary expansion decoupled directly after the BB. Only the Cosmic Microwave Background (CMB) has been detected and is well studied. Its spectrum follows Planck's black body radiation formula and shows a remarkable constant temperature of T0γ ≈ 2.7 K independent of the direction. The present photon density is about 370 photons per cm3. The size of the hot spots, which deviates only in the fifth decimal of the temperature from the average value, tells us, that the universe is flat. About 380 000 years after the Big Bang at a temperature of T0γ = 3000 K already in the matter dominated era the electrons combine with the protons and 4He and the photons move freely in the neutral universe and form the CMB. So the temperature and distribution of the photons give us information of the universe 380 000 years after the Big Bang. The Cosmic Neutrino Background (CνB) decoupled from matter already one second after the BB at a temperature of about 1010 K. Today their temperature is ∼ 1.95 K and the average density is 56 electron-neutrinos and the total density of all neutrinos about 336 per cm3. Measurement of these neutrinos is an extremely challenging experimental problem which can hardly be solved with the present technologies. On the other hand it represents a tempting opportunity to check one of the key elements of the Big Bang Cosmology and to probe the early stages of the universe. The search for the CνB with the induced beta decay νe+3H → 3He + e− using KATRIN (KArlsruhe TRItium Neutrino experiment) is the topic of this contribution

  5. Scouting's Explorer Program

    Science.gov (United States)

    Claerhout, John M.

    1970-01-01

    This article suggests the relationship which the Explorer program could have with colleges, employers, and the students and employees of the future. Exploring as a process of finding out can help young people find their identity, personally and vocationally, and enable college carrer counselors to expand on a sound foundation of vocational…

  6. Quark Matter in a Strong Magnetic Background

    CERN Document Server

    Gatto, Raoul

    2012-01-01

    In this chapter, we discuss several aspects of the theory of strong interactions in presence of a strong magnetic background. In particular, we summarize our results on the effect of the magnetic background on chiral symmetry restoration and deconfinement at finite temperature. Moreover, we compute the magnetic susceptibility of the chiral condensate and the quark polarization at zero temperature. Our theoretical framework is given by chiral models: the Nambu-Jona-Lasinio (NJL), the Polyakov improved NJL (or PNJL) and the Quark-Meson (QM) models. We also compare our results with the ones obtained by other groups.

  7. Natural background radiation and oncologic disease incidence

    International Nuclear Information System (INIS)

    Cause and effect relationships between oncologic disease incidence in human population and environmental factors are examined using investigation materials of Soviet and foreign authors. The data concerning US white population are adduced. The role and contribution of natural background radiation oncologic disease prevalence have been determined with the help of system information analysis. The probable damage of oncologic disease is shown to decrease as the background radiation level diminishes. The linear nature of dose-response relationspip has been established. The necessity to include the life history of the studied population along with environmental factors in epidemiological study under conditions of multiplicity of cancerogenesis causes is emphasized

  8. Cognitive psychology and depth psychology backgrounds

    International Nuclear Information System (INIS)

    The sixth chapter gives an insight into the risk perception process which is highly determined by emotions, and, thus, deals with the psychological backgrounds of both the conscious cognitive and the subconscious intuitive realms of the human psyche. The chapter deals with the formation of opinion and the origination of an attitude towards an issue; cognitive-psychological patterns of thinking from the field of risk perception; the question of man's rationality; pertinent aspects of group behaviour; depth psychological backgrounds of the fear of technology; the collective subconscious; nuclear energy as a preferred object of projection for various psychological problems of modern man. (HSCH)

  9. Uranium exploration in Ecuador

    International Nuclear Information System (INIS)

    The 600-km segment of the Andean Cordillera in Ecuador includes zones that can be correlated, geologically, with uranium districts elsewhere in the Andes. It is believed that these essentially unexplored zones have the potential for economic uranium mineralization. Exploration activity to date has been limited, although it has involved both geochemical and radiometric techniques to evaluate geological concepts. Minor uranium occurrences (with chemical analyses up to 100 ppm) have been encountered, which provide further incentive to commence large-scale systematic exploration. It is recognized that a very large exploration budget and considerable technical expertise will be required to ensure exploration success. Consequently, participation by groups of proven capability from other countries will be sought for Ecuador's national exploration programme. (author)

  10. Considering Background Condition Effects in Tailoring Tropical Forest Management Systems for Sustainability

    Directory of Open Access Journals (Sweden)

    Roderick J. Zagt

    2006-06-01

    Full Text Available Systems devised for managing tropical forests sustainably have yet to prove successful. In many instances, they have fallen short of initial prospects, but the reasons for these shortfalls are often not apparent. Here, we explore factors that can shape the likelihood of success, collectively referred to as background conditions, which are not always adequately considered prior to selecting a suitable management system. We examine the ability of one background condition, geologic terrane, to explain crude spatial variation in a number of trailing indicators of varying forest land use. Forest areas on Precambrian and Phanerozoic terranes show significant differences in production of fossil hydrocarbons, gold, and tropical roundwood, among other indicators, even after considering regional effects. Background conditions are considered to be factors capable of quantifying spatial variation in the likelihood of achieving management success given predefined benchmarks of sustainability. A number of avenues for further exploring and discriminating spatial variation of background conditions are discussed.

  11. Superconformal invariance and superstring in background fields

    International Nuclear Information System (INIS)

    We consider the propagation of the superstring on a general classical background containing the effects of the metric, the antisymmetric tensor and the dilaton fields. Using the operator product expansion method for two dimensional superconformal field theories we derive the equations for these fields as a consequence of the superconformal invariance of the theory. (author)

  12. Physiologic correlates to background noise acceptance

    Science.gov (United States)

    Tampas, Joanna; Harkrider, Ashley; Nabelek, Anna

    2001-05-01

    Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.

  13. BACKGROUND FACTORS AND SUCCESS IN COLLEGE PHYSICS.

    Science.gov (United States)

    BOLTE, JOHN R.

    FACTORS RELATED TO ACADEMIC ACHIEVEMENT IN FIRST YEAR COLLEGE PHYSICS WERE IDENTIFIED. DATA WERE OBTAINED FROM THE RECORDS OF 923 STUDENTS WHO HAD COMPLETED THE FIRST SEMESTER OF A COLLEGE PHYSICS COURSE DURING A 5-YEAR PERIOD. MULTIPLE CORRELATIONS WERE USED TO RELATE STUDENT BACKGROUND VARIABLES TO ACHIEVEMENT IN COLLEGE PHYSICS. HIGH SCHOOL…

  14. Controllable forms of natural background radiation

    International Nuclear Information System (INIS)

    RENA is a research programm into the controllable forms of natural background radiation, which cover the activities originating from the naturally occurring radionuclides enhanced by human intervention. In the RENA-program emphasis lays upon the policy aspects of environmental-hygienic, economical and governmental character. (H.W.). 15 refs.; 2 tabs

  15. The spinorial method of classifying supersymmetric backgrounds

    NARCIS (Netherlands)

    Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.

    2006-01-01

    We review how the classification of all supersymmetric backgrounds of IIB supergravity can be reduced to the evaluation of the Killing spinor equations and their integrability conditions, which contain the field equations, on five types of spinors. This is an extension of the work [hep-th/0503046] t

  16. Alpha Background Rejection in Bolometer Detectors

    Science.gov (United States)

    Deporzio, Nicholas

    2016-03-01

    This study presents the modification of bolometer detectors used in particle searches to veto or otherwise reject alpha radiation background and the statistical advantages of doing so. Several techniques are presented in detail - plastic film scintillator vetoes, metallic film ionization vetoes, and scintillating bolometer vetoes. Plastic scintillator films are cooled to bolometer temperatures and bombarded with 1.4MeV to 6.0MeV alpha particles representative of documented detector background. Photomultipliers detect this scintillation light and produce a veto signal. Layered metallic films of a primary metal, dielectric, and secondary metal, such as gold-polyethylene-gold films, are cooled to milli-kelvin temperatures and biased to produce a current signal veto when incident 1.4MeV to 6.0MeV alpha particles ionize conduction paths through the film. Modified Zinc Molybdate Bolometers are used to produce scintillation light when stimulated by alpha background. Calibration of veto signal to background energy is presented. Results are used to quantify the statistical impact of such modifications on bolometer searches.

  17. Generalized geometry lectures on type II backgrounds

    CERN Document Server

    Tsimpis, Dimitrios

    2016-01-01

    The first part of these notes is a self-contained introduction to generalized complex geometry. It is intended as a `user manual' for tools used in the study of supersymmetric backgrounds of supergravity. In the second part we review some past and recent results on the generalized complex structure of supersymmetric type II vacua in various dimensions.

  18. 40 CFR 105.1 - Background.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Background. 105.1 Section 105.1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS RECOGNITION AWARDS UNDER... provide official recognition to industrial organizations and political subdivisions of States which...

  19. Argon-39 Background in DUNE Photon Detectors

    Science.gov (United States)

    Sinev, Gleb; DUNE Collaboration

    2016-03-01

    The Deep Underground Neutrino Experiment (DUNE) is a 40-kt liquid argon detector that will be constructed 5000 ft underground in the Sanford Underground Research Facility in order to study neutrino and proton decay physics. Instrumenting liquid argon with photon detectors to record scintillation in addition to the ionization signal can significantly improve time and energy resolution of the experiment. Argon produces light with wavelength of 128 nm. The reference design for the photon detectors includes acrylic bars covered in wavelength shifter, where the scintillation light can be captured and reemitted with longer wavelengths, then detected using silicon photomultipliers. Radiological backgrounds may noticeably deteriorate the photon detection system performance, especially for low-energy interactions. A particularly important background comes from argon-39 decays, because argon-39 is present in natural argon that will be used in DUNE and the background rate increases with the size of the experiment. The effect of the argon-39 background has been studied and is presented in this talk.

  20. Social Background Differences in Early Family Behavior

    Science.gov (United States)

    Schoen, Robert; Landale, Nancy S.; Daniels, Kimberly; Cheng, Yen-Hsin Alice

    2009-01-01

    Social background has historically been recognized as a major factor influencing family behavior, though recent work has largely emphasized racial/ethnic influences. Here we use 1994 - 1995 and 2001 - 2002 Add Health data to examine the cohabitation, first marriage, and first birth experience of young women. In a multi state life table context,…

  1. Ablation plume dynamics in a background gas

    DEFF Research Database (Denmark)

    Amoruso, Salvatore; Schou, Jørgen; Lunney, James G.

    2010-01-01

    expansion. The model also leads to an insightful treatment of the stopping behavior in dimensionless units for plumes and background gases of different atomic/molecular masses. The energetics of the plume dynamics can also be treated with this model. Experimental time-of-flight data of silver ions in a neon...

  2. 22 CFR 1501.2 - Background.

    Science.gov (United States)

    2010-04-01

    ....C. 290h)). It is a non-profit, non-stock issuing, tax-exempt corporation, and is subject to title I... Relations AFRICAN DEVELOPMENT FOUNDATION ORGANIZATION Substantive Rule of General Applicability § 1501.2 Background. (a) The African Development Foundation (“ADF”) is a wholly-owned corporation of the United...

  3. Model-based target and background characterization

    Science.gov (United States)

    Mueller, Markus; Krueger, Wolfgang; Heinze, Norbert

    2000-07-01

    Up to now most approaches of target and background characterization (and exploitation) concentrate solely on the information given by pixels. In many cases this is a complex and unprofitable task. During the development of automatic exploitation algorithms the main goal is the optimization of certain performance parameters. These parameters are measured during test runs while applying one algorithm with one parameter set to images that constitute of image domains with very different domain characteristics (targets and various types of background clutter). Model based geocoding and registration approaches provide means for utilizing the information stored in GIS (Geographical Information Systems). The geographical information stored in the various GIS layers can define ROE (Regions of Expectations) and may allow for dedicated algorithm parametrization and development. ROI (Region of Interest) detection algorithms (in most cases MMO (Man- Made Object) detection) use implicit target and/or background models. The detection algorithms of ROIs utilize gradient direction models that have to be matched with transformed image domain data. In most cases simple threshold calculations on the match results discriminate target object signatures from the background. The geocoding approaches extract line-like structures (street signatures) from the image domain and match the graph constellation against a vector model extracted from a GIS (Geographical Information System) data base. Apart from geo-coding the algorithms can be also used for image-to-image registration (multi sensor and data fusion) and may be used for creation and validation of geographical maps.

  4. DUSEL Ultra-Low Background Counting Facility

    Science.gov (United States)

    Thomas, Keenan

    2007-10-01

    The Homestake Mine in western South Dakota has been confirmed by the National Science Foundation (NSF) as the site for a Deep Underground Science and Engineering Laboratory (DUSEL). Many of the physics, geosciences, and microbiology experiments in the facility will be funded by DOE and NSF, and will benefit the missions of these agencies. In support of these programs, physics faculty in South Dakota and scientists at Lawrence Berkeley National Laboratory have been working together to establish a multidisciplinary research cluster to provide baseline characterization for physics and geosciences/geomicrobiology experiments at the Homestake Mine through an Ultra-Low Background Counting Facility (ULBCoF). The proposed project utilizes two low-background germanium detectors with massive shielding underground to carefully analyze materials for low background experiments. Low background experiments such as double-beta decay, solar neutrino, geoneutrino, and dark matter must control the purity of all the materials used in the construction of a detector. Measuring such low counting rates is a very challenging task that will be best accomplished by primarily using high purity germanium (HPGe) detectors.

  5. Gravitational Wave Background from Phantom Superinflation

    OpenAIRE

    Piao, Yun-Song

    2006-01-01

    Recently, the early superinflation driven by phantom field has been proposed and studied. The detection of primordial gravitational wave is an important means to know the state of very early universe. In this brief report we discuss in detail the gravitational wave background excited during the phantom superinflation.

  6. Comparative Risk Aversion under Background Risk Revisited

    OpenAIRE

    Masamitsu Ohnishi; Yusuke Osaki

    2010-01-01

    This paper determines a new sufficient condition of the (von Neumann-Morgenstern) utility function that preserves comparative risk aversion under background risk. It is the single crossing condition of risk aversion. Because this condition requires monotonicity in the local sense, it may satisfy the U-shaped risk aversion observed in the recent empirical literature.

  7. Backgrounds of arithmetic and geometry an introduction

    CERN Document Server

    Miron, Radu

    1995-01-01

    The book is an introduction to the foundations of Mathematics. The use of the constructive method in Arithmetic and the axiomatic method in Geometry gives a unitary understanding of the backgrounds of geometry, of its development and of its organic link with the study of real numbers and algebraic structures.

  8. Climate change. Scientific background and process

    Energy Technology Data Exchange (ETDEWEB)

    Alfsen, Knut H.; Fuglestvedt, Jan; Seip, Hans Martin; Skodvin, Tora

    1999-07-01

    The paper describes briefly the natural and man-made forces behind climate change and outlines climate variations in the past. It also discusses the future impact of anthropogenic emission of greenhouse gases, and the background, organisation and functioning of the Intergovernmental Panel on Climate Change (IPCC)

  9. 32 CFR 735.2 - Background.

    Science.gov (United States)

    2010-07-01

    ... documentary evidence, acceptable in all courts, be required at any future time. Department of Defense (DOD... 32 National Defense 5 2010-07-01 2010-07-01 false Background. 735.2 Section 735.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL REPORTING BIRTHS AND DEATHS IN...

  10. THE TEMPERATURE OF THE COSMIC MICROWAVE BACKGROUND

    International Nuclear Information System (INIS)

    The Far InfraRed Absolute Spectrophotometer data are independently recalibrated using the Wilkinson Microwave Anisotropy Probe data to obtain a cosmic microwave background (CMB) temperature of 2.7260 ± 0.0013. Measurements of the temperature of the CMB are reviewed. The determination from the measurements from the literature is CMB temperature of 2.72548 ± 0.00057 K.

  11. Ablation plume dynamics in a background gas

    DEFF Research Database (Denmark)

    Amoruso, Salvatore; Schou, Jørgen; Lunney, James G.

    2010-01-01

    The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during the...

  12. 33 CFR 236.4 - Background.

    Science.gov (United States)

    2010-07-01

    ... QUALITY § 236.4 Background. (a) The role of the Corps of Engineers in the development of water and related... control, beach erosion control and hurricane protection, hydroelectric power, recreation, water supply, water quality, fish and wildlife and low-flow augmentation. Laws, executive orders, and...

  13. Natural background approach to setting radiation standards

    International Nuclear Information System (INIS)

    The suggestion has often been made that an additional radiation exposure imposed on humanity as a result of some important activity such as electricity generation would be acceptable if the exposure was small compared to the natural background. In order to make this concept quantitative and objective, we propose that small compared with the natural background be interpreted as the standard deviation (weighted with the exposed population) of the natural background. This use of the variation in natural background radiation is less arbitrary and requires fewer unfounded assumptions than some current approaches to standard-setting. The standard deviation is an easily calculated statistic that is small compared with the mean value for natural exposures of populations. It is an objectively determined quantity and its significance is generally understood. Its determination does not omit any of the pertinent data. When this method is applied to the population of the United States, it suggests that a dose of 20 mrem/year would be an acceptable standard. This is comparable to the 25 mrem/year suggested as the maximum allowable exposure to an individual from the complete uranium fuel cycle

  14. Women's Health Initiative (WHI) Background and Overview

    Science.gov (United States)

    ... CPS was to develop community-based public health interventions models which would achieve healthful behaviors in women aged 40 and over. A New ... all races and socioeconomic backgrounds to adopt healthful behaviors ... cessation, exercise and early detection of treatable health problems. The ...

  15. Perturbations of supertube in KK monopole background

    CERN Document Server

    Srivastava, Y K

    2006-01-01

    We study perturbations of supertube in KK monopole background, at both DBI and supergravity levels. We analyse both NS1-P as well as D0-F1 duality frames and study different profiles. This illuminates certain aspects of bound states of KK monopoles with supertubes.

  16. Ambient background measurement at PUSHEP tunnel

    International Nuclear Information System (INIS)

    In view of upcoming INO laboratory in India, a feasibility study of neutrinoless double beta decay (0υββ) in 124Sn has been initiated. The objective is to make a prototype bolometric detector of 124Sn (∼ 1 Kg equivalent) and install it in a low background area

  17. Background Lamb waves in the Earth's atmosphere

    Science.gov (United States)

    Nishida, K.; Kobayashi, N.; Fukao, Y.

    2013-12-01

    Lamb waves of the Earth's atmosphere in the millihertz band have been considered as transient phenomena excited only by large events [e.g. the major volcanic eruption of Krakatoa in 1833, the impact of Siberian meteorite in 1908, the testing of large nuclear tests and the huge earthquakes, Garrett1969]. In a case of the solid Earth, observation of background free oscillations in the millihertz band-now known as Earth's background free oscillations or seismic hum, has been firmly established. Above 5 mHz, their dominant excitation sources are oceanic infragravity waves. At 3.7 and 4.4 mHz an elasto-acoustic resonance between the solid Earth and the atmosphere was observed [Nishida et al., 2000]. These seismic observations show that the contribution of atmospheric disturbances to the seismic hum is dominant below 5 mHz. Such contribution implies background excitations of acoustic-gravity waves in this frequency range. For direct detection of the background acoustic-gravity waves, our group conducted observations using an array of barometers [Nishida et al. 2005]. However, the spatial scale of the array of about 10 km was too small to detect acoustic modes below 10 mHz. Since then, no direct observations of these waves have been reported. In 2011, 337 high-resolution microbarometers were installed on a continental scale at USArray Transportable Array. The large and dense array enables us to detect the background atmospheric waves. Here, we show the first evidence of background Lamb waves in the Earth's atmosphere from 0.2 to 10 mHz, based on the array analysis of microbarometer data from the USArray in 2012. The observations suggest that the excitation sources are atmospheric disturbances in the troposphere. Theoretically, their energy in the troposphere tunnels into the thermosphere at a resonant frequency via thermospheric gravity wave, where the observed amplitudes indeed take a local minimum. The energy leak through the frequency window could partly contribute to

  18. Background reduction in the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Segui, L. [University of Oxford, Denys Wilkinson Building, Keble Road, OX1 Oxford (United Kingdom)

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  19. International exploration by independents

    International Nuclear Information System (INIS)

    Recent industry trends indicate that the smaller US independents are looking at foreign exploration opportunities as one of the alternatives for growth in the new age of exploration. It is usually accepted that foreign finding costs per barrel are substantially lower than domestic because of the large reserve potential of international plays. To get involved overseas requires, however, an adaptation to different cultural, financial, legal, operational, and political conditions. Generally foreign exploration proceeds at a slower pace than domestic because concessions are granted by the government, or are explored in partnership with the national oil company. First, a mid- to long-term strategy, tailored to the goals and the financial capabilities of the company, must be prepared; it must be followed by an ongoing evaluation of quality prospects in various sedimentary basins, and a careful planning and conduct of the operations. To successfully explore overseas also requires the presence on the team of a minimum number of explorationists and engineers thoroughly familiar with the various exploratory and operational aspects of foreign work, having had a considerable amount of onsite experience in various geographical and climatic environments. Independents that are best suited for foreign expansion are those that have been financially successful domestically, and have a good discovery track record. When properly approached foreign exploration is well within the reach of smaller US independents and presents essentially no greater risk than domestic exploration; the reward, however, can be much larger and can catapult the company into the big leagues

  20. A Vigorous Explorer Program

    CERN Document Server

    Elvis, Martin; Brissenden, Roger; Chakrabarti, Supriya; Cherry, Michael; Devlin, Mark; Edelstein, Jerry; Eisenhardt, Peter; Feldman, Paul; Ford, Holland; Gehrels, Neil; Golub, Leon; Marshall, Herman; Martin, Christopher; Mather, John; McCandliss, Stephan; McConnell, Mark; McDowell, Jonathan; Meier, David; Millan, Robyn; Mitchell, John; Moos, Warren; Murray, Steven S; Nousek, John; Oegerle, William; Ramsey, Brian; Green, James; Grindlay, Jonathan; Kaaret, Philip; Kaiser, Mary Elizabeth; Kaltenegger, Lisa; Kasper, Justin; Krolik, Julian; Kruk, Jeffrey W; Latham, David; MacKenty, John; Mainzer, Amanda; Ricker, George; Rinehart, Stephen; Romaine, Suzanne; Scowen, Paul; Silver, Eric; Sonneborn, George; Stern, Daniel; Swain, Mark; Swank, Jean; Traub, Wesley; Weisskopf, Martin; Werner, Michael; Wright, Edward

    2009-01-01

    Explorers have made breakthroughs in many fields of astrophysics. The science from both these missions contributed to three Nobel Prizes - Giacconi (2002), Mather, and Smoot (2006). Explorers have: marked the definitive beginning of precision cosmology, discovered that short gamma-ray bursts are caused by compact star mergers and have measured metalicity to redshifts z>6. NASA Explorers do cutting-edge science that cannot be done by facility-class instruments. The Explorer program provides a rapid response to changing science and technology, to enable cutting-edge science at moderate cost. Explorers also enable innovation, and engage & train scientists, managers and engineers, adding human capital to NASA and the nation. The astrophysics Explorer launch rate now being achieved is 1 per 3 years, and budget projections are in the $150M/year range for the next five years. A newly Vigorous Explorer Program should be created to: 1. Reach the long-stated goal of annual astrophysics launches; 2. Find additional ...

  1. Geocoronal imaging with Dynamics Explorer

    Science.gov (United States)

    Rairden, R. L.; Frank, L. A.; Craven, J. D.

    1986-01-01

    The ultraviolet photometer of the University of Iowa spin-scan auroral imaging instrumentation on board Dynamics Explorer-1 has returned numerous hydrogen Lyman alpha images of the geocorona from altitudes of 570 km to 23,300 km (1.09 R sub E to 4.66 R sub E geocentric radial distance). The hydrogen density gradient is shown by a plot of the zenith intensities throughout this range, which decrease to near celestial background values as the spacecraft approaches apogee. Characterizing the upper geocorona as optically thin (single-scattering), the zenith intensity is converted directly to vertical column density. This approximation loses its validity deeper in the geocorona, where the hydrogen is demonstrated to be optically thick in that there is no Lyman alpha limb brightening. Further study of the geocoronal hydrogen distribution will require computer modeling of the radiative transfer.

  2. The functions of culture background knowledge in improving English reading in high school

    Institute of Scientific and Technical Information of China (English)

    乌日乐

    2014-01-01

    This paper argues that by strengthening awareness of students 'background knowledge can improve students'reading results .By testing ex-periments, surveys, all the data collected were analyzed . Experimental tests and surveys which are carried out in all the students . And contrast the Chinese culture and foreign culture;through all of the things found background knowledge can promote the sustainable develop -ment of the students'English reading , so there are many important practical significances and values to explore .

  3. Effects of host plant and genetic background on the fitness costs of resistance to Bacillus thuringiensis

    OpenAIRE

    Raymond, B.; Wright, D. J.; Bonsall, M B

    2010-01-01

    Novel resistance to pathogens and pesticides is commonly associated with a fitness cost. However, measurements of the fitness costs of insecticide resistance have used diverse methods to control for genetic background and rarely assess the effects of environmental variation. Here, we explored how genetic background interacts with resource quality to affect the expression of the fitness costs associated with resistance. We used a serially backcrossed line of the diamondback moth, Plutella xylo...

  4. The Impact of Perceived Background Risk on Behavioral Health: Evidence from Hurricane Katrina

    OpenAIRE

    Pesko, Michael

    2016-01-01

    I explore the hypothesis that Hurricane Katrina in 2005 raised perceived background risks, which had spillover effects on behavioral health outcomes of mental health, substance use, and health insurance. I explore this hypothesis using Behavioral Risk Factor Surveillance System data for 2002-2007. I use a difference-in-difference model to estimate the effect that Hurricane Katrina had in the non-damaged storm surge region, in 90-day intervals leading up to and after the hurricane, compared to...

  5. Choice of Study and Persistence in Higher Education by Immigrant Background, Gender, and Social Background

    OpenAIRE

    Støren, Liv Anne

    2009-01-01

    The aim of this report is to present documentation of new analyses carried out at NIFU STEP concerning differences by immigrant background, gender and social background with regard to choice of type study programme in higher education, as well as educational attainment and persistence in higher education. Many studies have been undertaken concerning completion of upper secondary education and enrolment into higher education in relation to immigrant background. Little is known, however, about ...

  6. Exploration: A misunderstood business

    International Nuclear Information System (INIS)

    The business of exploration is persistently misunderstand. Why? Misunderstandings persist and even pervade educated, sophisticated, and obviously capable business practitioners and savants of an array of disciplines - finance, economics, and the management sciences. Routine and appropriate assumptions that apply for most businesses invoke nonsense applied to exploration, a unique business. The uniqueness of exploration, unrecognized, sustains the misunderstandings. The authors will not here obliterate these obdurate misunderstandings with some revelation. They show, however, how the misunderstandings naturally arise among those who certainly are not used to being naive

  7. A Qualitative Phenomenological Exploration of Teachers' Experience with Nutrition Education

    Science.gov (United States)

    Hall, Elisha; Chai, Weiwen; Albrecht, Julie A.

    2016-01-01

    Background: Nutrition education delivered by classroom teachers has become a popular intervention designed to combat childhood obesity. However, few qualitative studies have explored nutrition education with teachers Purpose: The purpose of this study was to explore how elementary teachers describe their experience with nutrition education.…

  8. A Qualitative Phenomenological Exploration of Teachers' Experience With Nutrition Education

    OpenAIRE

    Hall, Elisha; Chai, Weiwen; Albrecht, Julie A.

    2016-01-01

    Background: Nutrition education delivered by classroom teachers has become a popular intervention designed to combat childhood obesity. However, few qualitative studies have explored nutrition education with teachers Purpose: The purpose of this study was to explore how elementary teachers describe their experience with nutrition education. Methods: A qualitative phenomenological approach was used. Semistructured interviews, observations, and document analysis were conducted with 10 teachers ...

  9. Exploring care for human service profession

    DEFF Research Database (Denmark)

    Høy, Bente

    2015-01-01

    Maintaining dignity in vulnerability Aim: To explore the meaning of maintaining dignity in eldercare from the perspective of nursing home residents. Background: Elderly people living in nursing homes are exposed to diverse situations which may be associated with loss of dignity. To help them...... maintain their dignity, it is important to explore, how dignity is maintained in such situations. Views of dignity and factors influencing dignity have been studied from both the nursing homes residents´ and the care providers´ perspective. However, little is known about how the residents’ experience their...

  10. Arts of urban exploration

    DEFF Research Database (Denmark)

    Pinder, David

    2005-01-01

    This paper addresses ways in which artists and cultural practitioners have recently been using forms of urban exploration as a means of engaging with, and intervening in, cities. It takes its cues from recent events on the streets of New York that involved exploring urban spaces through artistic...... that experimental modes of exploration can play a vital role in the development of critical approaches to the cultural geographies of cities. In particular, discussion centres on the political significance of these spatial practices, drawing out what they have to say about two interconnected themes: ‘rights...... to the city’ and ‘writing the city’. Through addressing recent cases of psychogeographical experimentation in terms of these themes, the paper raises broad questions about artistic practices and urban exploration to introduce this theme issue on ‘Arts of urban exploration’ and to lead into the specific...

  11. Uranium exploration in Australia

    International Nuclear Information System (INIS)

    Australia has more low-cost uranium in deposits than any other country, but finding it is not easy. While the price for uranium has been low, little was found but now exploration is starting to increase.

  12. Birth Control Explorer

    Science.gov (United States)

    ... Relationships STIs Media Facebook Twitter Tumblr Shares · 5 Birth Control Explorer Sort by all methods most effective methods ... 100% effective method of birth control. LEARN MORE IUD An IUD is a T-shaped device that ...

  13. Advanced Exploration Systems Program

    Data.gov (United States)

    National Aeronautics and Space Administration — AES consists of more than 35 projects that target high-priority capabilities needed for human exploration such as crew mobility, deep-space habitation, vehicle...

  14. Academics explore humidity's benefits.

    Science.gov (United States)

    Mortimer, Dave

    2008-11-01

    The effects of humidification on hospital superbugs are being explored by some of the UK's top academics, in what Dave Mortimer, national sales manager for Vapac Humidity Control, explains are the UK's first such studies. PMID:19044148

  15. Brazilian uranium exploration program

    International Nuclear Information System (INIS)

    General information on Brazilian Uranium Exploration Program, are presented. The mineralization processes of uranium depoits are described and the economic power of Brazil uranium reserves is evaluated. (M.C.K.)

  16. Exploring Clinical Overview

    DEFF Research Database (Denmark)

    Fleron, Benedicte

    Clinical overview is explored at four emergency departments (EDs) during the introduction of a new IT system to support hereof. Important aspects of clinical overview are described for the clinical practice and for the further development of the IT system.......Clinical overview is explored at four emergency departments (EDs) during the introduction of a new IT system to support hereof. Important aspects of clinical overview are described for the clinical practice and for the further development of the IT system....

  17. Exploring ambiguous realms

    DEFF Research Database (Denmark)

    Clemensen, Nana

    2016-01-01

    In Hang'ombe Village in rural Zambia, the relative lack of physical boundaries between the activities of family members allow children to observe the actions and discussions of adults on close hand, exposing them to the ambiguities of daily life. Children explore these ambiguities in their intera...... interactions, testing social roles and conventions. This article explores the vigilance and creative agency displayed by Hang'ombe children, in an environment spurring their acquisition of distinct social and discursive skills....

  18. Exploring Vietnam's oil potential

    International Nuclear Information System (INIS)

    A brief review is given of the oil production potential in Vietnam. Since Since 1987, the country has been open to foreign investment in offshore exploration but has suffered from a US embargo on trade and economic ties. Nevertheless some exploration has occurred and twenty production sharing contracts with international oil companies has been signed. To date most of the finds have been non-commercial but optimism remains high. (U.K.)

  19. Face Detection under Complex Background and Illumination

    Institute of Scientific and Technical Information of China (English)

    Shao-Dong Lv; Yong-Duan Song; Mei Xu; Cong-Ying Huang

    2015-01-01

    Abstract⎯For face detection under complex background and illumination, a detection method that combines the skin color segmentation and cost-sensitive Adaboost algorithm is proposed in this paper. First, by using the characteristic of human skin color clustering in the color space, the skin color area inYCbCr color space is extracted and a large number of irrelevant backgrounds are excluded; then for remedyingthe deficiencies of Adaboost algorithm, the cost-sensitive function is introduced into the Adaboost algorithm; finally the skin color segmentation and cost-sensitive Adaboost algorithm are combined for the face detection. Experimental results show that the proposed detection method has a higher detection rate and detection speed, which can more adapt to the actual field environment.

  20. Background paper on Technology Roadmaps (TRMs)

    Energy Technology Data Exchange (ETDEWEB)

    More, E.; Phaal, R. [Institute for Manufacturing IfM, Department of Engineering, University of Cambridge, Cambridge (United Kingdom); Londo, H.M.; Wurtenberger, L.; Cameron, L.R. [ECN Policy Studies, Amsterdam (Netherlands)

    2013-04-15

    This background paper reports on the use of technology roadmaps (TRMs) related to climate change mitigation and adaptation technologies. The study is motivated by the UNFCCC Conference of the Parties (CoP) request to the Technology Executive Committee (TEC) to catalyse the development and use of TRMs as facilitative tools for action on mitigation and adaptation. Having originated in industry, TRMs are now used extensively in policy settings too, however their widespread use across sectors and by different stakeholders has resulted in a lack of understanding of their real value to help catalyse cooperation towards technological solutions to the problems presented by climate change. Consequently this background paper presents (1) an overview of different TRM methods, (2) an initial analysis of gaps and barriers in existing TRMs, and (3) a review of current TRM good practices.

  1. Background formalism for superstring field theory

    International Nuclear Information System (INIS)

    In the framework of the background formalism we analyse possible versions of the Witten-type NSR superstring field theory. We find the picture for string fields to be uniquely fixed by the requirement that the perturbative classical solutions are well-defined. This uniquely defined picture and the corresponding action are different from the ones in Witten's theory and coincide with the ones proposed from different reasons in our previous paper. Following the same background method we calculate the tree-level scattering amplitudes for the new action and argue that in contrast to the ones in Witten's original theory, the amplitudes are singularity-free and hence there is no need to add any tree-level counterterms. We also prove the amplitudes to reproduce correctly the first quantized results. (orig.)

  2. The cosmic mult-messenger background field

    Science.gov (United States)

    Hartmann, Dieter

    2016-04-01

    The cosmic star formation history associated with baryon flows within the large scale structure of the expanding Universe has many important consequences, such as cosmic chemical- and galaxy evolution. Stars and accreting compact objects subsequently produce light, from the radio band to the highest photon energies, and dust within galaxies reprocesses a significant fraction of this light into the IR region. The Universe creates a radiation background that adds to the relic field from the big bang, the CMB. In addition, Cosmic Rays are created on variouys scales, and interact with this diffuse radiation field, and neutrinos are added as well. A multi-messenger field is created whose evolution with redshift contains a tremendous amount of cosmological information. We discuss several aspects of this story, emphasizing the background in the HE regime and the neutrino sector, and disccus the use of gamma-ray sources as probes.

  3. Foreign Energy Company Competitiveness: Background information

    Energy Technology Data Exchange (ETDEWEB)

    Weimar, M.R.; Freund, K.A.; Roop, J.M.

    1994-10-01

    This report provides background information to the report Energy Company Competitiveness: Little to Do With Subsidies (DOE 1994). The main body of this publication consists of data uncovered during the course of research on this DOE report. This data pertains to major government energy policies in each country studied. This report also provides a summary of the DOE report. In October 1993, the Office of Energy Intelligence, US Department of Energy (formerly the Office of Foreign Intelligence), requested that Pacific Northwest Laboratory prepare a report addressing policies and actions used by foreign governments to enhance the competitiveness of their energy firms. Pacific Northwest Laboratory prepared the report Energy Company Competitiveness Little to Do With Subsidies (DOE 1994), which provided the analysis requested by DOE. An appendix was also prepared, which provided extensive background documentation to the analysis. Because of the length of the appendix, Pacific Northwest Laboratory decided to publish this information separately, as contained in this report.

  4. Partition function for a singular background

    International Nuclear Information System (INIS)

    We present a method for evaluating the partition function in a varying external field. Specifically, we look at the case of a non-interacting, charged, massive scalar field at finite temperature with an associated chemical potential in the background of a delta-function potential. Whilst we present a general method, valid at all temperatures, we only give the result for the leading order term in the high temperature limit. Although the derivative expansion breaks down for inhomogeneous backgrounds we are able to obtain the high temperature expansion, as well as an analytic expression for the zero point energy, by way of a different approximation scheme, which we call the local Born approximation (LBA)

  5. The Background Geometry of DLCQ Supergravity

    CERN Document Server

    Hyun, S

    1998-01-01

    By following Seiberg's prescriptions on DLCQ of M theory, we give the background geometries of DLCQ supergravity associated with $N$ sector of DLCQ of M theory on $T^p$. Most of these are the product of anti-de Sitter spacetimes and spheres, which have been found as the spontaneous compactifications of eleven dimensional supergravity long time ago and also are revisited recently by Maldacena by considering the near horizon geometry of various D-branes in appropriate limit. Those geometries are maximally symmetric and have full 32 supersymmetries of eleven dimensional supergravity, which agrees with the number of supersymmetries of DLCQ M theory. This tells us that in the large $N$ limit of DLCQ M theory, we get M/string theory on these nontrivial background.

  6. Parental socioeconomic background and child behaviour

    DEFF Research Database (Denmark)

    Quinto Romani, Annette

    2014-01-01

    and resource constraints, respectively. We address this issue using a unique longitudinal data set of almost 1,500 schoolchildren attending state schools between 2008 and 2010 in the Danish Municipality of Aalborg. One empirical strategy is to control for a rich set of child and parental characteristics......; another is to use child fixed effect to control for fixed unobserved child characteristics. By including the interaction between child behaviour and parental socioeconomic background, a more complete but more complex picture arises. Our findings challenge the predominant assumption that behaviour...... set of child and parental characteristics; another is to use child fixed effect to control for fixed unobserved child characteristics. By including the interaction between child behaviour and parental socioeconomic background, a more complete but more complex picture arises. Our findings challenge...

  7. Motion Tracking with Fast Adaptive Background Subtraction

    Institute of Scientific and Technical Information of China (English)

    Xiao De-gui; Yu Sheng-sheng; Zhou Jing-li

    2003-01-01

    To extract and track moving objects is usually one of the most important tasks of intelligent video surveillance systems. This paper presents a fast and adaptive background subtraction algorithm and the motion tracking process using this algorithm. The algorithm uses only luminance components of sampled image sequence pixels and models every pixel in a statistical model. The algorithm is characterized by its ability of real time detecting sudden lighting changes, and extracting and tracking motion objects faster. It is shown that our algorithm can be realized with lower time and space complexity and adjustable object detection error rate with comparison to other background subtraction algorithms. Making use of the algorithm, an indoor monitoring system is also worked out and the motion tracking process is presented in this paper. Experimental results testify the algorithm's good performances when used in an indoor monitoring system.

  8. Global Warming and the Microwave Background

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-04-01

    Full Text Available In the work, the importance of assigning the microwave background to the Earth is ad- dressed while emphasizing the consequences for global climate change. Climate mod- els can only produce meaningful forecasts when they consider the real magnitude of all radiative processes. The oceans and continents both contribute to terrestrial emis- sions. However, the extent of oceanic radiation, particularly in the microwave region, raises concerns. This is not only since the globe is covered with water, but because the oceans themselves are likely to be weaker emitters than currently believed. Should the microwave background truly be generated by the oceans of the Earth, our planet would be a much less efficient emitter of radiation in this region of the electromagnetic spectrum. Furthermore, the oceans would appear unable to increase their emissions in the microwave in response to temperature elevation, as predicted by Stefan’s law. The results are significant relative to the modeling of global warming.

  9. Pairing in the cosmic neutrino background

    International Nuclear Information System (INIS)

    We extend the discussion of the possible superfluidity of the cosmic background of neutrinos beyond the arguments based on the gap equation, originally given by Ginzburg and Zharkov. We show how to develop a simple Ginzburg-Landau liquid model, in analogy with superconductivity. We use it to show how an analysis of the energy spectrum of the universe can be formulated to include general relativistic effects on the superfluid neutrinos. Finally, in view of the Hawking and Collins careful discussion on the rotation and distortion of a spatially homogeneous and isotropic universe, we discuss the vortex dynamics that might be generated on the superfluid by rotations (allowed by the almost isotropy of the microwave background of photons) of up to 2 x 10-14 second of arc/century, but conclude that rotations of this order of magnitude would be sufficiently strong to deter the existence of the superfluid state. (author)

  10. Giant gravitons in non-supersymmetric backgrounds

    International Nuclear Information System (INIS)

    We consider giant gravitons as probes of a class of ten-dimensional solutions of type-IIB supergravity which arise as lifts of solutions of U(1)3 gauged N=2 supergravity in five-dimensions. Surprisingly it is possible to solve exactly for minimum energy configurations of these spherical D3-brane probes in the compact directions, even in backgrounds which preserve no supersymmetry. The branes behave as massive charged particles in the five non-compact dimensions. As an example we probe geometries which are believed to represent the supergravity background of coherent states of giant gravitons. We comment on the apparently repulsive nature of the naked singularities in these geometries. (author)

  11. Cosmic Infrared Background Fluctuations and Zodiacal Light

    CERN Document Server

    Arendt, Richard G; Moseley, S H; Mather, J

    2016-01-01

    We have performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution, or from IRAC observations of high latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS field, at low ecliptic latitude where the zodiacal light intensity varies by factors of $\\sim2$ over the range of solar elongations at which the field can be observed. We find that the white noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that ...

  12. Supersymmetric backgrounds and generalised special holonomy

    Science.gov (United States)

    Coimbra, André; Strickland-Constable, Charles; Waldram, Daniel

    2016-06-01

    We define intrinsic torsion in generalised geometry and use it to introduce a new notion of generalised special holonomy. We then consider generic warped supersymmetric flux compactifications of M theory and Type II of the form {{{R}}}D-{1,1}× M. Using the language of {E}d(d)× {{{R}}}+ generalised geometry, we show that, for D≥slant 4, preserving minimal supersymmetry is equivalent to the manifold M having generalised special holonomy and list the relevant holonomy groups. We conjecture that this result extends to backgrounds preserving any number of supersymmetries. As a prime example, we consider { N }=1 in D = 4. The corresponding generalised special holonomy group is {SU}(7), giving the natural M theory extension to the notion of a G 2 manifold, and, for Type II backgrounds, reformulating the pure spinor {SU}(3)× {SU}(3) conditions as an integrable structure.

  13. Polarization Observations with the Cosmic Background Imager

    CERN Document Server

    Readhead, A C S; Pearson, T J; Sievers, J L; Mason, B S; Contaldi, C R; Bond, J R; Bustos, R; Altamirano, P; Achermann, C; Bronfman, L; Carlstrom, J E; Cartwright, J K; Casassus, S; Dickinson, C; Holzapfel, W L; Kovács, J M; Leitch, E M; May, J; Padin, S; Pogosyan, D; Pospieszalski, M; Pryke, C L; Reeves, R; Shepherd, M C; Torres, S

    2004-01-01

    Polarization observations of the cosmic microwave background with the Cosmic Background Imager over the period September 2002 - May 2004 provide a highly significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectrum, as predicted by theory. This key agreement between the phase of the observed polarization spectrum and that predicted based on the total intensity spectrum provides new support for the standard model of cosmology, in which dark matter and dark energy are the dominant constituents, the geometry is close to flat, and primordial density fluctuations are predominantly adiabatic with a matter power spectrum commensurate with inflationary cosmological models.

  14. Social background, bullying, and physical inactivity

    DEFF Research Database (Denmark)

    Henriksen, P W; Rayce, S B; Melkevik, O;

    2015-01-01

    More children from lower social backgrounds are physically inactive than those from higher ones. We studied whether bullying was a mediating factor between lower social background and physical inactivity. We also examined the combined effect of low social class and exposure to bullying on physical...... leaves 4.0% in the category physically inactive. The sex and age-adjusted OR (95% CI) for physical inactivity was 2.10 (1.39-3.18) among students with low social class and unclassifiable 3.53 (2.26-5.53). Exposure to bullying was associated with physical inactivity, sex and age-adjusted OR = 2.39 (1.......67-3.41). Exposure to bullying did not explain the association between social class and physical inactivity. The association between social class and physical inactivity was more pronounced among participants also exposed to bullying. In conclusion, there was a significantly increased odds ratio for physical...

  15. Polarization observations with the Cosmic Background Imager.

    Science.gov (United States)

    Readhead, A C S; Myers, S T; Pearson, T J; Sievers, J L; Mason, B S; Contaldi, C R; Bond, J R; Bustos, R; Altamirano, P; Achermann, C; Bronfman, L; Carlstrom, J E; Cartwright, J K; Casassus, S; Dickinson, C; Holzapfel, W L; Kovac, J M; Leitch, E M; May, J; Padin, S; Pogosyan, D; Pospieszalski, M; Pryke, C; Reeves, R; Shepherd, M C; Torres, S

    2004-10-29

    Polarization observations of the cosmic microwave background with the Cosmic Background Imager from September 2002 to May 2004 provide a significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectrum. This key agreement between the phase of the observed polarization spectrum and that predicted on the basis of the total intensity spectrum provides support for the standard model of cosmology, in which dark matter and dark energy are the dominant constituents, the geometry is close to flat, and primordial density fluctuations are predominantly adiabatic with a matter power spectrum commensurate with inflationary cosmological models. PMID:15472038

  16. Gravitational Lensing of Cosmic Microwave Background Polarization

    CERN Document Server

    Ade, P A R; Anthony, A E; Arnold, K; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feng, C; Flanigan, D; Gilbert, A; Grainger, W; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Hori, Y; Howard, J; Hyland, P; Inoue, Y; Jaehnig, G C; Jaffe, A; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Jeune, M Le; Lee, A T; Linder, E; Lungu, M; Matsuda, F; Matsumura, T; Meng, X; Miller, N J; Morii, H; Moyerman, S; Myers, M J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Quealy, E; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Schanning, I; Schenck, D E; Sherwin, B; Shimizu, A; Shimmin, C; Shimon, M; Siritanasak, P; Smecher, G; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Takakura, S; Tomaru, T; Wilson, B; Yadav, A; Zahn, O

    2013-01-01

    Primary fluctuations in both temperature and polarization of the Cosmic Microwave Background (CMB) reflect the properties of the Universe from the Big Bang until the photons decoupled from matter 380,000 years later. These primary fluctuations are then lensed by large-scale structures (such as clusters of galaxies and filaments of dark matter), with the result that the distribution and properties of dark matter, including the masses of neutrinos, can be determined more accurately by extracting the lensing information than through studying the primary fluctuations alone. Polarization lensing can give cleaner, higher resolution results than temperature lensing. The correlation of lensed CMB polarization with large-scale structure, traced through the Cosmic Infrared Background, was recently detected; however, this correlation does not trace all structure and depends on the relationship between the infrared flux from the galaxies and the underlying mass distribution. Here we report the detection of gravitational ...

  17. Torsion and Supersymmetry in Omega-background

    CERN Document Server

    Ito, Katsushi; Sasaki, Shin

    2012-01-01

    We study the dimensional reduction of ten-dimensional super Yang-Mills theory in curved backgrounds with torsion. We examine the parallel spinor conditions and the constraints for the torsion parameters which preserve supersymmetry and gauge symmetry in four dimensions. In particular we examine the ten-dimensional Omega-background with the torsion which is identified with the R-symmetry Wilson line gauge fields. After the dimensional reduction, we obtain the Omega-deformed N=4 super Yang-Mills theory. Solving the parallel spinor conditions and the torsion constraints, we classify the deformed supersymmetry associated with the topological twist of N=4 supersymmetry. We also study deformed supersymmetries in the Nekrasov-Shatashvili limit.

  18. Electromagnetic Polarizabilities: Lattice QCD in Background Fields

    CERN Document Server

    Detmold, W; Walker-Loud, A

    2011-01-01

    Chiral perturbation theory makes definitive predictions for the extrinsic behavior of hadrons in external electric and magnetic fields. Near the chiral limit, the electric and magnetic polarizabilities of pions, kaons, and nucleons are determined in terms of a few well-known parameters. In this limit, hadrons become quantum mechanically diffuse as polarizabilities scale with the inverse square-root of the quark mass. In some cases, however, such predictions from chiral perturbation theory have not compared well with experimental data. Ultimately we must turn to first principles numerical simulations of QCD to determine properties of hadrons, and confront the predictions of chiral perturbation theory. To address the electromagnetic polarizabilities, we utilize the background field technique. Restricting our attention to calculations in background electric fields, we demonstrate new techniques to determine electric polarizabilities and baryon magnetic moments for both charged and neutral states. As we can study...

  19. Cross-platform practices for background services

    OpenAIRE

    Engbo, Jonas

    2015-01-01

    A platform means a kind of hardware, software or a combination of the two. Differences between these leads to complexity when an application is to be ported to another platform. Programming languages handle abstraction in different ways but there are methods for making the transition easier. Background services have conceptual differences between platforms which makes them interesting from a cross-platform perspective. Different programming languages like C, C#, Java and Python can initialize...

  20. Prague Aerosol Supersite, Suchdol (PASS, urban background)

    Czech Academy of Sciences Publication Activity Database

    Ždímal, Vladimír; Ondráček, Jakub; Zíková, Naděžda; Vodička, Petr; Makeš, Otakar; Řimnáčová, Daniela; Štefancová, Lucia; Šilhavý, J.; Smolík, Jiří; Schwarz, Jaroslav

    - : -, 2012, P286. [European Aerosol Confrernce EAC 2012. Granada (ES), 02.09.2012-07.09.2012] R&D Projects: GA ČR GAP209/11/1342 Grant ostatní: MF NF(CZ) A/CZ0046/2/2001; UFIREG(XE) 3CE288P3 Institutional support: RVO:67985858 Keywords : atmospheric aerosol * urban background Subject RIV: CF - Physical ; Theoretical Chemistry http://www.eac2012.com/EAC2012Book/3.html

  1. Personality, social background, and occupational career success

    OpenAIRE

    Gelissen, John; Graaf, Paul M. de

    2006-01-01

    Pooled cross-sectional and life-history data from the Dutch Family Survey 1998 and 2000 (N = 4000) were used to investigate whether personality was directly related to income attainment and occupational career transitions after controlling for human capital indicators, working hours, and parental social background. The results indicated that there were substantive direct relations between personality traits and occupational career success. Extraversion related positively to remuneration but o...

  2. The Cosmic Background Radiation, Snowmass Workshop

    OpenAIRE

    Smoot, George F.

    1995-01-01

    Observations of the Cosmic Microwave background have provided many of the most powerful constraints we have on cosmology and events in the early universe. The spectrum and isotropy of CBR have long been a pillar of Big Bang models. The discovery of low levels on anisotropy has provided new information and tools for our understanding of the early universe. Further observations promise to enhance greatly our knowledge of processes in the early universe and cosmological parameters. We can antici...

  3. Ultraviolet Background Radiation from Cosmic Structure Formation

    OpenAIRE

    Miniati, Francesco; Ferrara, Andrea; White, Simon D. M.; Bianchi, Simone

    2003-01-01

    We calculate the contribution to the ultraviolet background (UVB) from thermal emission from gas shock heated by cosmic structure formation. Our main calculation is based on an updated version of Press-Schechter theory. It is consistent with a more empirical estimate based on the observed properties of galaxies and the observed cosmic star formation history. Thermal UVB emission is characterized by a hard spectrum extending well beyond 4 Ry. The bulk of the radiation is produced by objects in...

  4. Ground state energy in smooth background fields

    International Nuclear Information System (INIS)

    We consider the backreaction problem for a smooth background field depending on one coordinate. We give a reformulation so that the scattering data of the corresponding Schroedinger equation become the independent variables. Using knowledge from the inverse scattering method it is shown that the problem can be reduced to an algebraic one within an arbitrary good approximation. For the simplest case an explicit example is given. (orig.)

  5. Soft branes in supersymmetry-breaking backgrounds

    OpenAIRE

    McGuirk, Paul; Shiu, Gary; Ye, Fang

    2012-01-01

    We revisit the analysis of effective field theories resulting from non-supersymmetric perturbations to supersymmetric flux compactifications of the type-IIB superstring with an eye towards those resulting from the backreaction of a small number of anti-D3-branes. Independently of the background, we show that the low-energy Lagrangian describing the fluctuations of a stack of probe D3-branes exhibits soft supersymmetry breaking, despite perturbations to marginal operators that were not fully c...

  6. Involuntary Resettlement: Operational Policy and Background Paper

    OpenAIRE

    Inter-American Development Bank (IDB)

    1998-01-01

    This document presents the Bank's official Policy on Involuntary Resettlement and includes the background paper, which was the basis for the development of the policy. This policy covers any involuntary physical displacement of people caused by a Bank project. It applies to all Bank funded operations, in the public or private sector, whether Bank financing is directly channeled (as in investment loans) or administered by intermediaries (as in multiple works, time-slice or multisector credit p...

  7. Dips in the Diffuse Supernova Neutrino Background

    OpenAIRE

    Farzan, Yasaman; Palomares-Ruiz, Sergio(Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia, Spain)

    2014-01-01

    Scalar (fermion) dark matter with mass in the MeV range coupled to ordinary neutrinos and another fermion (scalar) is motivated by scenarios that establish a link between radiatively generated neutrino masses and the dark matter relic density. With such a coupling, cosmic supernova neutrinos, on their way to us, could resonantly interact with the background dark matter particles, giving rise to a dip in their redshift-integrated spectra. Current and future neutrino dete...

  8. Polarization of the Microwave Background: theoretical framework

    OpenAIRE

    Melchiorri, Alessandro; Vittorio, Nicola

    1996-01-01

    We present a brief review of the polarization properties of the cosmic microwave background in dark matter models for structure formation. Quite independently of the model parameters, the polarization level is expected to be $\\sim 10%$ of the anisotropy signal at angular scales $\\le 1^o$. Detections of polarization at larger angular scales would provide a strong evidence in favour of an early reionization of the intergalactic medium.

  9. Massive Gravity in Ads and Minkowski Backgrounds

    OpenAIRE

    Porrati, M.

    2004-01-01

    I review some interesting features of massive gravity in two maximally symmetric backgrounds: Anti de Sitter space and Minkowski space. While massive gravity in AdS can be seen as a spontaneously broken, UV safe theory, no such interpretation exists yet in the flat-space case. Here, I point out the problems encountered in trying to find such completion, and possible mechanisms to overcome them.

  10. Automated FingerPrint Background removal: FPB

    OpenAIRE

    Morgante Michele; Scalabrin Simone; Policriti Alberto

    2009-01-01

    Abstract Background The construction of a whole-genome physical map has been an essential component of numerous genome projects initiated since the inception of the Human Genome Project. Its usefulness has been proved for whole-genome shotgun projects as a post-assembly validation and recently it has also been used in the assembly step to constrain on BACs positions. Fingerprinting is usually the method of choice for construction of physical maps. A clone fingerprint is composed of true peaks...

  11. French Students of Maghreb Background and Entrepreneurship

    OpenAIRE

    Hicham MEGHOUAR

    2014-01-01

    The aim of this article is to analyze the theoretical motivations for entrepreneurship among French students of Maghreb background (hereafter FSMB). Indeed, there are two opposing logics: the entrepreneurial logic, and the social integration one. Is entrepreneurship still seen as a last chance for these young studentswho are stigmatized (Goffman, 1975) and socially labeled (Becker, 1985), and who remain very often unemployed after graduation? Or does it fit in the context of the ambitious ind...

  12. Lectures on branes in curved backgrounds

    International Nuclear Information System (INIS)

    These lectures provide an introduction to the microscopic description of branes in curved backgrounds. After a brief reminder of the flat space theory, the basic principles and techniques of (rational) boundary conformal field theory are presented in the second lecture. The general formalism is then illustrated through a detailed discussion of branes on compact group manifolds. In the final lecture, many more recent developments are reviewed, including some results for non-compact target spaces

  13. Speech Recognition in Natural Background Noise

    OpenAIRE

    Julien Meyer; Laure Dentel; Fanny Meunier

    2013-01-01

    In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listene...

  14. Retinal Image Preprocessing: Background and Noise Segmentation

    OpenAIRE

    Usman Akram

    2012-01-01

    Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse ...

  15. Soudan Low Background Counting Facility (SOLO)

    International Nuclear Information System (INIS)

    The Soudan Low Background Counting Facility (SOLO) has been in operation at the Soudan Mine, MN since March 2003. In the past two years, we have gamma-screened samples for the Majorana, CDMS and XENON experiments. With individual sample exposure times of up to two weeks we have measured sample contamination down to the 0.1 ppb level for 238U / 232Th, and down to the 0.25 ppm level for 40K

  16. Exploration Laboratory Analysis

    Science.gov (United States)

    Krihak, M.; Ronzano, K.; Shaw, T.

    2016-01-01

    The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability (ExMC) risk to minimize or reduce the risk of adverse health outcomes and decrements in performance due to in-flight medical capabilities on human exploration missions. To mitigate this risk, the availability of inflight laboratory analysis instrumentation has been identified as an essential capability for manned exploration missions. Since a single, compact space-ready laboratory analysis capability to perform all exploration clinical measurements is not commercially available, the ELA project objective is to demonstrate the feasibility of emerging operational and analytical capability as a biomedical diagnostics precursor to long duration manned exploration missions. The initial step towards ground and flight demonstrations in fiscal year (FY) 2015 was the down selection of platform technologies for demonstrations in the space environment. The technologies selected included two Small Business Innovation Research (SBIR) performers: DNA Medicine Institutes rHEALTH X and Intelligent Optical Systems later flow assays combined with Holomics smartphone analyzer. The selection of these technologies were based on their compact size, breadth of analytical capability and favorable ability to process fluids in a space environment, among several factors. These two technologies will be advanced to meet ground and flight demonstration success criteria and requirements that will be finalized in FY16. Also, the down selected performers will continue the technology development phase towards meeting prototype deliverables in either late 2016 or 2017.

  17. International exploration by independents

    International Nuclear Information System (INIS)

    Recent industry trends indicate that the smaller U.S. independents are looking at foreign exploration opportunities as one of the alternatives for growth in the new age of exploration. The problems of communications and logistics caused by different cultures and by geographic distances must be carefully evaluated. A mid-term to long-term strategy tailored to the goals and the financial capabilities of the company should be prepared and followed by a careful planning of the operations. This paper addresses some aspects of foreign exploration that should be considered before an independent venture into the foreign field. It also provides some guidelines for conducting successful overseas operations. When properly assessed, foreign exploration is well within the reach of smaller U.S. independents and presents no greater risk than domestic exploration; the rewards, however, can be much larger. Furthermore, the Oil and Gas Journal surveys of the 300 largest U.S. petroleum companies show that companies with a consistent foreign exploration policy have fared better financially during difficult times

  18. Background to Dark Matter Searches from Galactic Cosmic Rays

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Just as searches for BSM physics at the LHC necessitate a careful audit of SM backgrounds, the search for signals of dark matter in cosmic rays must contend with production of secondaries like e+ and pbar through cosmic ray propagation in the Galaxy. The theoretical framework for calculating this has however not been directly calibrated at the high energies being explored by AMS-02 and there may be surprises in store. In particular a nearby source where cosmic rays are being accelerated stochastically can naturally generate a e+ fraction rising with energy as is observed. The test of this is the expected correlated rise in other secondary/primary ratios e.g. B/C and pbar/p. Such a nearby cosmic accelerator should also be detectable through the concomitant flux of neutrinos and its discovery would be (nearly!) as exciting as that of dark matter.

  19. Killing superalgebra deformations of ten-dimensional supergravity backgrounds

    International Nuclear Information System (INIS)

    We explore Lie superalgebra deformations of the Killing superalgebras of some ten-dimensional supergravity backgrounds. We prove the rigidity of the Poincare superalgebras in types I, IIA and IIB, as well as of the Killing superalgebra of the Freund-Rubin vacuum of type IIB supergravity. We also prove rigidity of the Killing superalgebras of the NS5-, D0-, D3-, D4- and D5-branes, whereas we exhibit the possible deformations of the D1-, D2-, D6- and D7-brane Killing superalgebras, as well as of that of the type II fundamental string solutions. We relate the superalgebra deformations of the D2- and D6-branes to those of the (delocalized) M2-brane and the Kaluza-Klein monopole, respectively. The good behaviour under Kaluza-Klein reduction suggests that the deformed superalgebras ought to have a geometric interpretation

  20. The ROSAT X-ray Background Dipole

    CERN Document Server

    Plionis, M

    1998-01-01

    We estimate the dipole of the diffuse 1.5 keV X-ray background from the ROSAT all-sky survey map of Snowden et al (1995). We first subtract the diffuse Galactic emission by fitting to the data an exponential scale height, finite radius, disk model. We further exclude regions of low galactic latitudes, of local X-ray emission (eg the North Polar Spur) and model them using two different methods. We find that the ROSAT X-ray background (XRB) dipole points towards $(l,b) ~ (288, 25) \\pm 19 degrees within 30 degrees of the CMB dipole. Its direction is also in good agreement with the HEAO1 X-ray dipole at harder energies. The normalised amplitude of the ROSAT XRB dipole is about 1.7 per cent. Subtracting from the ROSAT map the expected X-ray background dipole due to the reflex motion of the observer with respect to the cosmic rest frame (Compton-Geting effect) we find the large-scale dipole of the X-ray emitting extragalactic sources having an amplitude 90% of the total XRB, in general agreement with the prediction...

  1. Background complexity affects colour preference in bumblebees

    Science.gov (United States)

    Forrest, Jessica; Thomson, James D.

    2009-08-01

    Flowers adapted for hummingbird pollination are typically red. This correlation is usually explained by the assertion that nectar- or pollen-stealing bees are “blind” to red flowers. However, laboratory studies have shown that bees are capable of locating artificial red flowers and often show no innate preference for blue over red. We hypothesised that these findings might be artefacts of the simplified laboratory environment. Using bumblebees ( Bombus impatiens) that had been trained to visit red and blue artificial flowers, we tested whether colour preference was influenced by complexity of the background on which they were foraging. Many bees were indifferent to flower colour when tested using a uniform green background like those commonly used in laboratory studies, but all bees showed strong colour preferences (usually for blue) when flowers were presented against a photograph of real foliage. Overall, preference for blue flowers was significantly greater on the more realistic, complex background. These results support the notion that the red of “hummingbird syndrome” flowers can function to reduce bee visits despite the ability of bees to detect red and highlight the need to consider context when drawing inferences about pollinator preferences from laboratory data.

  2. Cosmic Infrared Background Fluctuations and Zodiacal Light

    Science.gov (United States)

    Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

    2016-06-01

    We performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution or from IRAC observations of high-latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS field at low ecliptic latitude where the zodiacal light intensity varies by factors of ∼2 over the range of solar elongations at which the field can be observed. We find that the white-noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that are evident in the zodiacal light model. At large angular scales (≳100″) where excess power above the white noise is observed, we find no correlation of the power with the modeled intensity of the zodiacal light. This test clearly indicates that the large-scale power in the infrared background is not being caused by the zodiacal light.

  3. Background Model for the Majorana Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Cuesta, C.; Abgrall, N.; Aguayo, Estanislao; Avignone, Frank T.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Byram, D.; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, Reyco; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Laferriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Nomachi, Masaharu; Orrell, John L.; O' Shaughnessy, C.; Overman, Nicole R.; Phillips, D.; Poon, Alan; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, Werner; Trimble, J. E.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2015-06-01

    The Majorana Collaboration is constructing a prototype system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment to search for neutrinoless double-beta (0v BB) decay in 76Ge. In view of the requirement that the next generation of tonne-scale Ge-based 0vBB-decay experiment be capable of probing the neutrino mass scale in the inverted-hierarchy region, a major goal of theMajorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using Geant4 simulations of the different background components whose purity levels are constrained from radioassay measurements.

  4. Geometry of all supersymmetric type I backgrounds

    International Nuclear Information System (INIS)

    We find the geometry of all supersymmetric type I backgrounds by solving the gravitino and dilatino Killing spinor equations, using the spinorial geometry technique, in all cases. The solutions of the gravitino Killing spinor equation are characterized by their isotropy group in Spin(9, 1), while the solutions of the dilatino Killing spinor equation are characterized by their isotropy group in the subgroup Σ(P) of Spin(9, 1) which preserves the space of parallel spinors P. Given a solution of the gravitino Killing spinor equation with L parallel spinors, L = 1, 2, 3, 4, 5, 6, 8, the dilatino Killing spinor equation allows for solutions with N supersymmetries for any 0 < N ≤ L. Moreover for L = 16, we confirm that N = 8, 10, 12, 14, 16. We find that in most cases the Bianchi identities and the field equations of type I backgrounds imply a further reduction of the holonomy of the supercovariant connection. In addition, we show that in some cases if the holonomy group of the supercovariant connection is precisely the isotropy group of the parallel spinors, then all parallel spinors are Killing and so there are no backgrounds with N < L supersymmetries

  5. Background levels in the Borexino detector

    International Nuclear Information System (INIS)

    The Borexino detector, designed and constructed for sub-MeV solar neutrino spectroscopy, is taking data at the Gran Sasso Laboratory, Italy; since May 2007. The main physics objective of Borexino, based on elastic scattering of neutrinos in organic liquid scintillator, is the real time flux measurement of the 862keV mono-energetic neutrinos from 7Be, which set extremely severe radio-purity requirements in the detector's design and handling. The first year of continuous data taking provide now evidence of the extremely low background levels achieved in the construction of the detector and in the purification of the target mass. Several pieces of analysis sense the presence of radioisotopes of the 238U and 232Th chains, of 85Kr and of 210Po out of equilibrium from other Radon daughters. Particular emphasis is given to the detection of the cosmic muon background whose angular distributions have been obtained with the outer detector tracking algorithm and to the possibility of tagging the muon-induced neutron background in the scintillator with the recently enhanced electronics setup.

  6. Debris Disk Explorer : Exploring Stellar Dust Rings

    Science.gov (United States)

    Roberts, Lewis C.; Bryden, G.; Traub, W. A.; Unwin, S. C.; Trauger, J. T.; Krist, J. E.; Star Halo Team

    2013-01-01

    The Debris Disk Explorer (DDX) is a proposed balloon-borne science investigation of debris disks around nearby stars. Debris disks are analogs of the Asteroid Belt (mainly rocky) and Kuiper Belt (mainly icy) in our Solar System. DDX will measure the size, shape, brightness, and color of a statistically significant sample of disks. These measurements will enable us to probe these fundamental questions: what do debris disks tell us about the evolution of planetary systems; how are debris disks produced; how are debris disks shaped by planets; what materials are debris disks made of; how much dust do debris disks make as they grind down; and how long do debris disks live? The DDX instrument is a 0.7-m diameter ultra-light weight off-axis telescope and an imaging coronagraph on a gondola carried by a stratospheric balloon. Its data product is a set of images of each targeted debris disk in multiple broad visible wavelength bands. DDX will address its science questions by taking high-resolution, multi-wavelength images of the debris disks around tens of nearby stars. Two flights are planned; an overnight test flight within the United States followed by a half-global flight in the Southern Hemisphere. This longer flight is needed to fully explore the set of known debris disks accessible only to DDX. It will achieve a raw contrast of 10^-7, with a processed contrast of 10^-8. No existing telescope can match the DDX contrast and resolution performance. A second objective of DDX is to use the near-space environment to raise the Technology Readiness Level (TRL) internal coronagraphs, deformable mirrors, and wavefront sensing and control, all potentially needed for a future space-based telescope for high-contrast exoplanet imaging, for example the Astrophysics Focused Telescope Asset (AFTA) Design Reference study.

  7. Background subtraction in 99Tcm-DTPA renography using multiple background regions: a comparison of methods

    International Nuclear Information System (INIS)

    In order to obtain quantitative information from a 99Tcm-diethylenetriaminepentaacetate (DTPA) renogram it is first necessary to correct for the presence of background activity in the kidney time-activity curve. Three different methods of background subtraction which have been previously described are compared. Method 1 is a linear regression technique which uses separate tissue and heart time-activity curves to represent the background. Method 2 also uses multiple background regions and involves multiple regression. Method 3 uses a single heart region to represent the background. The three techniques are assessed using both simulation studies and patient data. The results show that method 3, which does not correct for extravascular activity, overestimates renal function particularly in poorly functioning kidneys. Method 1 gives the most accurate and reproducible results for both the simulation studies and patient data. (author)

  8. Chinese Curriculum Design and Motivation of Chinese Background Students in Australian Tertiary Education

    OpenAIRE

    Shi Li

    2010-01-01

    This study explores the need for a change in the current Chinese curriculum for Chinese-background students at the University of Newcastle (UoN). It examines the motivation behind the learning behaviour of Chinese-background students enrolling in the discipline of Chinese at the UoN as well as Chinese curriculum design at other Australian universities. The data from two sources were collected and analysed, Chinese-background students in the Chinese discipline at the UoN and lecturers in the C...

  9. Gauge symmetry and background independence: Should the proton spin decomposition be path independent?

    International Nuclear Information System (INIS)

    Exploring the similarities between the Chen et al. approach, where physical and gauge degrees of freedom of the gauge potential are explicitly separated, and the background field method, we provide an alternative point of view to the proton spin decomposition issue. We show in particular that the gauge symmetry can be realized in two different ways, and discuss the relations between the concepts of path dependence, Stueckelberg dependence and background dependence. Finally, we argue that path/Stueckelberg/background-dependent decompositions of the proton spin are in principle measurable and therefore physically meaningful

  10. PIPER: Primordial Inflation Polarization Explorer

    Science.gov (United States)

    Lazear, Justin; Ade, P.; Benford, D. J.; Bennett, C. L.; Chuss, D. T.; Dotson, J. L.; Eimer, J.; Fixsen, D. J.; Halpern, M.; Hinderks, J.; Hinshaw, G. F.; Irwin, K.; Jhabvala, C.; Johnson, B.; Kogut, A. J.; Mirel, P.; Moseley, S. H.; Staguhn, J.; Switzer, E.; Tucker, C. E.; Weston, A.; Wollack, E.

    2014-01-01

    The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne cosmic microwave background (CMB) polarization experiment searching for large-angular scale B-mode polarization to constrain Inflation in the early universe. The Inflationary Big Bang theory predicts that the epoch of inflation will result in a background of gravitational waves. These gravitational waves imprinted their unique B-mode signature on the CMB polarization, two features of which are a peak at ell ~ 80 and a "bump" below ell ~ 10 in the B-mode angular power spectrum. The ell ~ 80 "recombination" peak is the first peak caused by gravitational waves imprinting tensor (B-mode) perturbations onto the CMB spectrum during recombination. Gravitational waves at larger scales have not yet entered the horizon and may not contribute, and at smaller scales have decayed away by other interactions, giving rise to a peak at horizon scale. The ell ~ 10 "reionization" bump is caused by a similar mechanism as the recombination peak, where gravitational waves imprint B-mode perturbations into the spectrum, now at larger horizon scales. PIPER will target the reionization bump while keeping enough angular resolution to measure the recombination peak, with sensitivity down to tensor-to-scalar ratio r = 0.007. A series of flights alternating between north and south will produce nearly full-sky temperature and polarization maps and measure the low-ell spectra. 5120 transition edge sensor (TES) bolometers each with 20 arcmin beamwidth, distributed into 4 rectangular close-packed arrays maintained at 150 mK will provide small-scale resolution and sensitivity. PIPER consists of two co-aligned telescopes, each with a front-end variable-delay polarization modulator rapidly modulating either the Q or U Stokes parameters to provide polarization sensitivity and mitigate systematic errors. To achieve background-limited sensitivity, the entire instrument is enclosed in an open bucket dewar maintained at 1.5 K. PIPER

  11. Priorities for Venus Exploration

    Science.gov (United States)

    Glaze, L. S.; Beauchamp, P. M.; Chin, G.; Crisp, D.; Grimm, R. E.; Herrick, R. R.; Johnston, S.; Limaye, S. S.; Smrekar, S. E.; Ocampo, A.; Thompson, T. W.

    2013-12-01

    Venus remains one of the most enigmatic bodies in our Solar System. Important questions remain regarding the origin and evolution of the atmosphere, the history of the surface and interior, and how the surface and atmosphere interact. In a broader context, understanding Venus has implications for understanding the evolution of terrestrial planets in our Solar System as well as for interpreting the growing set of observations of extra-solar planets. The Venus Exploration Analysis Group (VEXAG), established in 2005, is chartered by NASA's Planetary Science Division and reports its findings to the NASA Advisory Council. Open to all interested scientists, VEXAG regularly evaluates Venus exploration goals, scientific objectives, investigations and critical measurement requirements, including especially recommendations in the NRC Decadal Survey and the Solar System Exploration Strategic Roadmap. At the last general meeting in November 2012, VEXAG resolved to update the scientific priorities and strategies for Venus exploration. To achieve this goal, three major tasks were defined for 2013, (1) update the document prioritizing Goals, Objectives and Investigations for Venus Exploration, (2) develop a Roadmap for Venus exploration that is consistent with VEXAG priorities as well as Planetary Decadal Survey priorities, and (3) develop a white paper on technologies for Venus missions. Proposed versions of all three documents were presented at the VEXAG general meeting in November 2013. Here, we present the findings and final versions of all three documents for community comment and feedback. A follow-on Workshop on Venus Exploration Targets is also being planned for the early summer of 2014. The workshop will provide a forum for the Venus science community to discuss approaches for addressing high priority investigations. Participants will be encouraged to present their ideas for specific targets on Venus (interior, surface and atmosphere) as well as to present specific data

  12. Primordial Inflation Polarization Explorer: Status and Plans

    Science.gov (United States)

    Kogut, Alan

    2009-01-01

    The Primordial Inflation Polarization Explorer is a balloon-borne instrument to measure the polarization of the cosmic microwave background in order to detect the characteristic signature of gravity waves created during an inflationary epoch in the early universe. PIPER combines cold /I.G K\\ optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. I will discuss the current status and plans for the PIPER instrument.

  13. Cosmic microwave background polarization in Noncommutative space-time

    CERN Document Server

    Batebi, S; Mohammadi, R; Tizchang, S

    2016-01-01

    In the standard model of cosmology (SMC) the B-mode polarization of the CMB can be explained by the gravitational effects in the inflation epoch. However, this is not the only way to explain the B-mode polarization for the CMB. It can be shown that the Compton scattering in presence of a background besides generating a circularly polarized microwave, can leads to a B-mode polarization for the CMB. Here we consider the non-commutative (NC) space time as a background to explore the CMB polarization at the last scattering surface. We obtain the B-mode spectrum of the CMB radiation by scalar perturbation of metric via a correction on the Compton scattering in NC-space-time in terms of the circular polarization power spectrum and the non-commutative energy scale. It can be shown that even for the NC-scale as large as $10TeV$ the NC-effects on the CMB polarization and the r-parameter is significant. We show that the V-mode power spectrum can be obtained in terms of linearly polarized power spectrum in the range Mic...

  14. Energetics of internal solitary waves in a background sheared current

    Directory of Open Access Journals (Sweden)

    K. G. Lamb

    2010-10-01

    Full Text Available The energetics of internal waves in the presence of a background sheared current is explored via numerical simulations for four different situations based on oceanographic conditions: the nonlinear interaction of two internal solitary waves; an internal solitary wave shoaling through a turning point; internal solitary wave reflection from a sloping boundary and a deep-water internal seiche trapped in a deep basin. In the simulations with variable water depth using the Boussinesq approximation the combination of a background sheared current, bathymetry and a rigid lid results in a change in the total energy of the system due to the work done by a pressure change that is established across the domain. A final simulation of the deep-water internal seiche in which the Boussinesq approximation is not invoked and a diffuse air-water interface is added to the system results in the energy remaining constant because the generation of surface waves prevents the establishment of a net pressure increase across the domain. The difference in the perturbation energy in the Boussinesq and non-Boussinesq simulations is accounted for by the surface waves.

  15. Extracting the cosmic history from diffuse backgrounds

    Science.gov (United States)

    Pritchard, Jonathan Robin

    The modern picture of the Universe resembles a detective novel with the first page and the middle chapters removed and the ending unwritten. Observations of the cosmic microwave background (CMB) have given cosmologists a snapshot of the Universe when it was only a few hundred thousand years old. At the same time, large galaxy surveys, such as SDSS and 2dF, have shed light on the distribution of matter in the local Universe. From the combination of these two data sets, cosmological parameters can be measured to percent accuracy. Two main frontiers remain: inflation, the domain of high-energy physics, and the epoch of reionization, the period connecting the linear age of the CMB with that of the present day. Added to this are the indications from supernovae of an acceleration in the expansion rate suggesting modifications to gravity or the presence of an esoteric new form of energy.In this work, we investigate uses of various radiation backgrounds for probing the different epochs of this cosmic history. We examine (i) the use of B-mode polarization of the CMB induced by an inflationary gravitational wave background to probe inflation, (ii) the importance of higher Lyman series photons in pumping of the 21 cm line and the consequences for the 21 cm signal from the first stars, (iii) the atomic physics of Lyman series photon scattering in the intergalactic medium and the consequences for heating and coupling of the 21 cm line, (iv) the possibility of using the 21 cm line to probe inhomogeneous X-ray heating of the IGM by a population of early X-ray sources, and (v) the impact of inhomogeneous reionization on galaxy formation and the consequences for our ability to use large galaxy surveys to constrain dark energy. Together, these chapters significantly extend our understanding of important windows into the early Universe.

  16. JOURNALISM STUDIES IN ARGENTINA: BACKGROUND AND QUESTIONS

    Directory of Open Access Journals (Sweden)

    Adriana Amado

    2014-06-01

    Full Text Available This article summarizes the background of empirical journalism studies in Argentina.  In recent publications, researchers have consistently underscored the lack of data on the profession and the scarce development of theoretical frameworks related to journalism studies.  The local investigations have prioritized approaches and methods that do not give the whole picture of the population of journalists. Most of the research tends to equate media analysis and media messages with journalism study and keeps on failing to provide data that allows for learning about the working conditions and the professional profile of the Argentinean journalists.

  17. Coulomb field in a constant electromagnetic background

    CERN Document Server

    Adorno, T C; Shabad, A E

    2016-01-01

    Nonlinear Maxwell equations are written up to the third-power deviations from a constant-field background, valid within any local nonlinear electrodynamics including QED with Euler-Heisenberg effective Lagrangian. Linear electric response to imposed static finite-sized charge is found in the vacuum filled by an arbitrary combination of constant and homogeneous electric and magnetic fields. The modified Coulomb field, corrections to the total charge and to the charge density are given in terms of derivatives of the effective Lagrangian with respect to the field invariants.

  18. Low background germanium detector technology from Canberra

    International Nuclear Information System (INIS)

    Full text: Since Eurisys Mesures and Canberra merged into one company under the wings of Cogema-Areva in February 2001, decades of know-how and experience in building Germanium detectors for low level gamma ray analysis have been brought together. This vast experience means that Canberra can offer a large variety of 'low level detectors' depending on the application. The complexity and cost of these detectors increase with the decreasing detection limits that our customers want to obtain. In this paper we give a short overview of the various categories of 'low level HP Ge detectors' that we produce. We present some examples of detection limits that can be obtained with each of these and we show what measures are taken to come to the next lower limit of detection. The spectroscopist should be aware, however, that the detection limit that can be obtained with a particular source and isotope mix depends in the first place on the choice of the detector element geometry and size, and on the geometry of the cryostat and source. Reference discusses this aspect of the optimum counting conditions. The choice of the shielding and the location of the detector-shield combination (above or below ground level) comes in second place. The precise design and choice of materials for the cryostat -- the subject of this paper -- are generally only the third factor of importance. The simplest low level gamma counting system that we consider in this paper consists of a standard high purity germanium detector in a standard lead shield. The cryostat materials used for these standard detectors are selected mainly for their mechanical properties and cost. Selection of the cryostat materials for their radio-purity comes only in the second place. The contribution of their activities to the background in the spectrum is neglectable since the measuring times are usually limited (typically 1 hour) and the background coming from the room and from the sample is generally higher. Detection limits

  19. Low background Germanium detector technology from Canberra

    International Nuclear Information System (INIS)

    Full text: Since Eurisys Mesures and Canberra merged into one company under the wings of Cogema-Areva in February 2001, decades of know-how and experience in building Germanium detectors for low level gamma ray analysis have been brought together. This vast experience means that Canberra can offer a large variety of 'low level detectors' depending on the application. The complexity and cost of these detectors increase with the decreasing detection limits that our customers want to obtain. In this paper we give a short overview of the various categories of 'low level HP Ge detectors' that we produce. We present some examples of detection limits that can be obtained with each of these and we show what measures are taken to come to the next lower limit of detection. The spectroscopist should be aware, however, that the detection limit that can be obtained with a particular source and isotope mix depends in the first place on the choice of the detector element geometry and size, and on the geometry of the cryostat and source. Reference discusses this aspect of the optimum counting conditions. The choice of the shielding and the location of the detector-shield combination (above or below ground level) comes in second place. The precise design and choice of materials for the cryostat - the subject of this paper - are generally only the third factor of importance. The simplest low level gamma counting system that we consider in this paper consists of a standard high purity germanium detector in a standard lead shield. The cryostat materials used for these standard detectors are selected mainly for their mechanical properties and cost. Selection of the cryostat materials for their radio-purity comes only in second place. The contribution of their activities to the background in the spectrum is negligible since the measuring times are usually limited (typically 1 hour) and the background coming from the room and the sample is generally higher. Detection limits that are

  20. Cosmological Background torsion limits from Lorentz violation

    CERN Document Server

    Garcia de Andrade, L C

    2001-01-01

    Cosmological limits on Lorentz invariance breaking in Chern-Simons $(3+1)-dimensional$ electrodynamics are used to place limits on torsion. Birefrigence phenomena is discussed by using extending the propagation equation to Riemann-Cartan spacetimes instead of treating it in purely Riemannian spaces. The parameter of Lorentz violation is shown to be proportional to the axial torsion vector which allows us to place a limit on cosmological background torsion from the Lorentz violation constraint which is given by $ 10^{-33} eV <|S^{\\mu}| < 10^{-32} eV$ where $|S^{\\mu}|$ is the axial torsion vector.

  1. Beam Delivery WG Summary: Optics, Collimation & Background

    Energy Technology Data Exchange (ETDEWEB)

    Angal-Kalinin, D.; Jackson, F.; /Daresbury; Mokhov, N.V.; /Fermilab; Kuroda, S.; /KEK, Tsukuba; Seryi, A.A.; /SLAC

    2006-01-20

    The presented paper partially summarizes the work of the Beam Delivery working group (WG4) at Snowmass, concentrating on status of optics, layout, collimation, and background. The strawman layout with 2 interaction regions was recommended at the first ILC workshop at KEK in November 2004. Two crossing-angle designs were included in this layout. The design of the ILC BDS has evolved since the first ILC workshop. The progress on the BDS design and extraction line design has been reviewed and the design issues were discussed during the optics and layout session at the Snowmass.

  2. Ultra-Low Background DNA Cloning System

    OpenAIRE

    Goto, Kenta; Nagano, Yukio

    2013-01-01

    Yeast-based in vivo cloning is useful for cloning DNA fragments into plasmid vectors and is based on the ability of yeast to recombine the DNA fragments by homologous recombination. Although this method is efficient, it produces some by-products. We have developed an “ultra-low background DNA cloning system” on the basis of yeast-based in vivo cloning, by almost completely eliminating the generation of by-products and applying the method to commonly used Escherichia coli vectors, particularly...

  3. Teaching in Multicultural Background in the States

    Institute of Scientific and Technical Information of China (English)

    潘若芸

    2010-01-01

    The diversity present in every aspect of American life is an inevitable consequence of its multicultural society.Schools across the country are a reflection of what is,and always has been,an ever changing demographic constitution.Classroom teachers,especially teachers who have no teaching experience in the country,face a stiff challenge of teaching all students,regardless of their backgrounds.As a Chinese guest teacher in the States,I learned that the"growing-up"of a teacher requires positive changes in three areas:knowledge,attitudes and skills.Support from administrators is also vital in the"growing-up"process.

  4. Detection Prospects of the Cosmic Neutrino Background

    CERN Document Server

    Li, Yu-Feng

    2015-01-01

    The existence of the cosmic neutrino background (CnuB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CnuB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CnuB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHEC\

  5. SKA synergy with Microwave Background studies

    CERN Document Server

    Burigana, Carlo; Baccigalupi, Carlo; Barbosa, Domingos; Blanchard, Alain; De Rosa, Adriano; de Zotti, Gianfranco; Finelli, Fabio; Gruppuso, Alessandro; Jones, Michael; Matarrese, Sabino; Melchiorri, Alessandro; Molinari, Diego; Negrello, Mattia; Paoletti, Daniela; Perrotta, Francesca; Scaramella, Roberto; Trombetti, Tiziana

    2015-01-01

    The extremely high sensitivity and resolution of the Square Kilometre Array (SKA) will be useful for addressing a wide set of themes relevant for cosmology, in synergy with current and future cosmic microwave background (CMB) projects. Many of these themes also have a link with future optical-IR and X-ray observations. We discuss the scientific perspectives for these goals, the instrumental requirements and the observational and data analysis approaches, and identify several topics that are important for cosmology and astrophysics at different cosmic epochs.

  6. Brief historical background of Miamisburg Indian Mound

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Lorraine M. [comp.

    1960-01-01

    The construction of Mound Laboratory was completed in 1948. The name Mound Laboratory was chosen for this installation because of the major Indian Mound which is immediately adjacent to the Plant site. Frequent inquiries of visitors to Mound Lab concerning the Indian Mounds in general and specifically Miamisburg's Indian Mound has indicated an area of "outside interest". We, therefore, thought it would be appropriate to furnish this brief historical background to all of the attendees at the Twentieth Meeting of the Mechanical Equipment Management Subgroup.

  7. Precision Detection of the Cosmic Neutrino Background

    International Nuclear Information System (INIS)

    In the standard big bang cosmology the canonical value for the ratio of relic neutrinos to cosmic microwave background (CMB) photons is 9/11. Within the framework of the standard model of particle physics there are small corrections, in sum about 1% , due to slight heating of neutrinos by electron-positron annihilations and finite-temperature QED effects. We show that this leads to changes in the predicted CMB anisotropies that will bias determination of the other cosmological parameters if not correctly taken into account. These changes might be detected by future satellite experiments. copyright 1999 The American Physical Society

  8. Cosmology with cosmic microwave background anisotropy

    Indian Academy of Sciences (India)

    Tarun Sourdeep

    2006-10-01

    Measurements of CMB anisotropy and, more recently, polarization have played a very important role in allowing precise determination of various parameters of the `standard' cosmological model. The expectation of the paradigm of inflation and the generic prediction of the simplest realization of inflationary scenario in the early Universe have also been established - `acausally' correlated initial perturbations in a flat, statistically isotropic Universe, adiabatic nature of primordial density perturbations. Direct evidence for gravitational instability mechanism for structure formation from primordial perturbations has been established. In the next decade, future experiments promise to strengthen these deductions and uncover the remaining crucial signature of inflation - the primordial gravitational wave background.

  9. Pandemic Influenza Background (PDF 99 KB)

    OpenAIRE

    Department of Health; Social Services and Public Safety

    2006-01-01

    The Presence of highly pathogenicH5N1 avian influenza has been confirmed in birds in Turkey, Romania, Russia and Kazakhstan. There have been a total of 4 confirmed cases of human infection in Eastern/South Eastern Turkey that has resulted in 2 deaths. Background Avian influenza naturally circulates in wild waterfowl such as ducks and geese often causing little or no symptoms. Many other bird species are susceptible to infection with these influenza viruses and in many of these species i...

  10. East African English. Linguistic Features and Background

    OpenAIRE

    Hermann Ingi Ragnarsson 1983

    2011-01-01

    The aim of this paper is to describe the most notable features and background of English in East Africa. That is: Kenya, Tanzania and Uganda. For this to be possible, English as a second language has to be discussed, since English is the second, third, or even fourth language of East Africa’s inhabitants. The development and characteristics of English in Africa generally will thus be discussed before the discussion turns to East African English with a special emphasis on Kenya. One of the ...

  11. Simulation of cosmological stochastic background in LISA

    International Nuclear Information System (INIS)

    A pilot study has been carried out to simulate stochastic gravitational wave background originating from first order phase transitions in the early universe. The space based gravitational wave detector LISA will be operational in the range of 10-4 to 0.1 Hz and could be sensitive to the red shifted gravitational waves from cosmological origin. In this study we have modeled the signals from first order phase transitions and we compared the signal both with the expected instrumental noise and realistic simulated foreground signals, originating from the white dwarf population in our galaxy.

  12. The Dortmund Low Background Facility - Low-background gamma ray spectrometry with an artificial overburden.

    Science.gov (United States)

    Gastrich, Holger; Gößling, Claus; Klingenberg, Reiner; Kröninger, Kevin; Neddermann, Till; Nitsch, Christian; Quante, Thomas; Zuber, Kai

    2016-06-01

    The Dortmund Low Background Facility is an instrument for low-level gamma ray spectrometry with an artificial overburden of ten meters of water equivalent, an inner shielding, featuring a neutron absorber, and an active muon veto. An integral background count rate between 40keV and 2700keV of (2.528±0.004)counts/(kgmin) enables low-background gamma ray spectrometry with sensitivities in the range of some 10mBq/kg within a week of measurement time. PMID:27082973

  13. Correlation between work concentration level and background music: a pilot study.

    Science.gov (United States)

    Shih, Yi-Nuo; Huang, Rong-Hwa; Chiang, Han-Sun

    2009-01-01

    It is a common phenomenon for office workers {to listen to music} while executing daily routines at their desks. The aim of this study was to investigate the correlation between work concentration level and background music. This research would first follow examples in previous researches, and then explore the influence of background music on participants' scores on attention tests. We hope to gain a preliminary understanding of the possible influence of background music on people's focus and concentration when doing work. Thirty-two college students were separated into three controlled groups; all were given the attention test. Group [a] listened to background music while being tested for 10 minutes; group [b] had no background music at all; and group [c] listened to the music for 10 minutes prior to the attention test. The test was conducted in a "noise free" environment. The means and error rates for each group were then calculated. The findings showed that, in comparison with "no music at all", those who listened to music prior to testing obtained higher scores in attentiveness (most probably a supplemental effect of the music), whereas those who listened to music during attention test showed extremely high level of variation in attention test scoring. Background music does affect people's job-site behavior. In fact, all three test conditions - no background music at all, background music before the work shift, and background music during work - have affected worker performance on different levels. PMID:19759431

  14. 4. What Roles Do Parent Involvement, Family Background, and Culture Play in Student Motivation?

    Science.gov (United States)

    Usher, Alexandra; Kober, Nancy

    2012-01-01

    This is the fourth in a series of six papers from the Center on Education Policy exploring issues related to students' motivation to learn. This paper examines findings from research about the impact of various family background and cultural factors on student motivation, as well as the role of parental beliefs, attitudes, and actions in fostering…

  15. Mission-Based Funding Compacts with Public Universities. Go8 Backgrounder 6

    Science.gov (United States)

    Group of Eight (NJ1), 2008

    2008-01-01

    This Go8 Backgrounder explores the possible uses of compacts in government financing of university activities, examines their potential costs and benefits, and outlines principles for their design and implementation. The Government has committed to compacts as an element of its future funding arrangements with public universities but has not yet…

  16. Family Perspectives: Using a Cultural Prism to Understand Families from Asian Cultural Backgrounds

    Science.gov (United States)

    Lee, Suk-Hyang; Turnbull, Ann P.; Zan, Fei

    2009-01-01

    Educators can better serve students who come from diverse cultural backgrounds by understanding the differing cultural values of these students and their families. This article explores different cultural perspectives using a cultural prism approach, focused most specifically on the Korean and Chinese cultures. (Contains 2 tables.)

  17. Mapping Gender and Social Background Differences in Education and Youth Transitions across Europe

    Science.gov (United States)

    Iannelli, Cristina; Smyth, Emer

    2008-01-01

    This paper uses data drawn from the European Union Labour Force Survey 2000 Ad Hoc Module on School to Work Transitions to explore the influence of gender and social background (measured in terms of parental education) on young people's educational and early labour market outcomes across 12 European countries. Our results show that social…

  18. Investigating Primary English Immersion Teachers in China: Background, Instructional Contexts, Professional Development, and Perceptions

    Science.gov (United States)

    Song, Xiaomei; Cheng, Liying

    2011-01-01

    Despite the fast growth of English immersion in China, only limited research has been conducted regarding immersion teachers' educational background, instructional contexts, professional development, and their perceptions about English immersion. This study explored the above key issues from three primary immersion schools. Results indicated that…

  19. Marine Mineral Exploration

    DEFF Research Database (Denmark)

    exploration requires knowledge of mineral deposits and models of their formation, of geophysical and geochemical exploration methods, and of data evaluation and interpretation methods. These topics are described in detail by an international group of authors. A short description is also given of marine......The past 20 years have seen extensive marine exploration work by the major industrialized countries. Studies have, in part, been concentrated on Pacific manganese nodule occurrences and on massive sulfides on mid-oceanic ridges. An international jurisdictional framework of the sea-bed mineral...... resources was negotiated by the United Nations Conference on the Law of the Sea (UNCLOS III). A most important outcome of this conference was the establishment of an Exclusive Economic Zone (EEZ) of at least 200 nautical miles for all coastal states and the recognition of a deep-sea regime. Mineral deposits...

  20. Interactive Chemical Reactivity Exploration

    CERN Document Server

    Haag, Moritz P; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. We employ a haptic pointer device with force-feedback to allow the operator the direct manipulation of structures in three dimensions along with simultaneous perception of the quantum mechanical response upon structure modification as forces. We elaborate on the details of how such an interactive exploration should proceed and which technical difficulties need to be overcome. All reactivity-exploration concepts developed for this purpose have been implemented in the Samson programming environment.