WorldWideScience

Sample records for understanding background gas

  1. Beam-gas Background Observations at LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00214737; The ATLAS collaboration; Alici, Andrea; Lazic, Dragoslav-Laza; Alemany Fernandez, Reyes; Alessio, Federico; Bregliozzi, Giuseppe; Burkhardt, Helmut; Corti, Gloria; Guthoff, Moritz; Manousos, Athanasios; Sjoebaek, Kyrre; D'Auria, Saverio

    2017-01-01

    Observations of beam-induced background at LHC during 2015 and 2016 are presented in this paper. The four LHC experiments use the non-colliding bunches present in the physics-filling pattern of the accelerator to trigger on beam-gas interactions. During luminosity production the LHC experiments record the beam-gas interactions using dedicated background monitors. These data are sent to the LHC control system and are used to monitor the background levels at the experiments during accelerator operation. This is a very important measurement, since poor beam-induced background conditions can seriously affect the performance of the detectors. A summary of the evolution of the background levels during 2015 and 2016 is given in these proceedings.

  2. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R. [VTT Energy, Espoo (Finland). Energy Systems

    1997-12-31

    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  3. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R [VTT Energy, Espoo (Finland). Energy Systems

    1998-12-31

    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  4. 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 expa......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 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...... background gas show a fair agreement with predictions from the PM-model. Finally we discuss the validity of the model, if the work done by the pressure of the background gas is neglected....

  5. Beam-gas background calculation for DEAR

    International Nuclear Information System (INIS)

    Guiducci, S.

    1997-01-01

    The present paper describes the results obtained from a Monte Carlo simulation of the particles lost in the DAY-ONE Interaction Region (IR) of the DAFNE machine. Coulomb scattering on the nuclei of residual gas and beam-gas Bremsstrahlung, which are the main sources of background in the initial phase of machine operation, were considered. A ray-tracking program (TURTLE) was used to follow the trajectories of the particles in the rings and to evaluate the number of particles that hit the vacuum chamber in the interaction region

  6. Cosmic gamma-ray background radiation. Current understandings and problems

    International Nuclear Information System (INIS)

    Inoue, Yoshiyuki

    2015-01-01

    The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space telescope has recently measured it at 0.1-820 GeV and revealed that the cosmic GeV gamma-ray background is composed of blazars, radio galaxies, and star-forming galaxies. However, Fermi still leaves the following questions. Those are dark matter contribution, origins of the cosmic MeV gamma-ray background, and the connection to the IceCube TeV-PeV neutrino events. In this proceeding, I will review the current understandings of the cosmic gamma-ray background and discuss future prospects of cosmic gamma-ray background radiation studies. (author)

  7. Cosmic X-ray background from hot gas

    International Nuclear Information System (INIS)

    Rogers, R.D.; Field, G.B.

    1991-01-01

    This paper considers constraints on models of the cosmic X-ray background (XRB) in which the XRB is produced by optically thin thermal bremsstrahlung from hot gas. It is shown that models in which the gas is gravitationally confined in a spherical configuration and is heated only once are contradicted by the observed number of gravitationally lensed quasars together with the lower limit on the number of XRB sources required by limits on fluctuations in the XRB and the cosmic microwave background. In addition, it is shown that, for models in which the gas is not gravitationally confined, the expansion time of the gas is much shorter than the radiative cooling time, so that such models cannot explain the XRB. It is concluded that thermal bremsstrahlung models cannot account for the XRB if the emitting gas is heated only once. 31 refs

  8. Development of Trivia Game for speech understanding in background noise.

    Science.gov (United States)

    Schwartz, Kathryn; Ringleb, Stacie I; Sandberg, Hilary; Raymer, Anastasia; Watson, Ginger S

    2015-01-01

    Listening in noise is an everyday activity and poses a challenge for many people. To improve the ability to understand speech in noise, a computerized auditory rehabilitation game was developed. In Trivia Game players are challenged to answer trivia questions spoken aloud. As players progress through the game, the level of background noise increases. A study using Trivia Game was conducted as a proof-of-concept investigation in healthy participants. College students with normal hearing were randomly assigned to a control (n = 13) or a treatment (n = 14) group. Treatment participants played Trivia Game 12 times over a 4-week period. All participants completed objective (auditory-only and audiovisual formats) and subjective listening in noise measures at baseline and 4 weeks later. There were no statistical differences between the groups at baseline. At post-test, the treatment group significantly improved their overall speech understanding in noise in the audiovisual condition and reported significant benefits in their functional listening abilities. Playing Trivia Game improved speech understanding in noise in healthy listeners. Significant findings for the audiovisual condition suggest that participants improved face-reading abilities. Trivia Game may be a platform for investigating changes in speech understanding in individuals with sensory, linguistic and cognitive impairments.

  9. Gas leak detection in infrared video with background modeling

    Science.gov (United States)

    Zeng, Xiaoxia; Huang, Likun

    2018-03-01

    Background modeling plays an important role in the task of gas detection based on infrared video. VIBE algorithm is a widely used background modeling algorithm in recent years. However, the processing speed of the VIBE algorithm sometimes cannot meet the requirements of some real time detection applications. Therefore, based on the traditional VIBE algorithm, we propose a fast prospect model and optimize the results by combining the connected domain algorithm and the nine-spaces algorithm in the following processing steps. Experiments show the effectiveness of the proposed method.

  10. Canada's east coast offshore oil and gas industry: a backgrounder

    International Nuclear Information System (INIS)

    Bott, R.

    1999-06-01

    Another of the backgrounder series published by the Petroleum Communication Foundation, this booklet describes Canada's offshore oil and natural gas operations in the North Atlantic Ocean, specifically in the Hibernia (off Newfoundland, crude oil), Terra Nova (off Newfoundland, crude oil), Cohasset-Panuke (off Nova Scotia, crude oil) and Sable Island (off Nova Scotia, natural gas) fields. Together, these project represent an investment of more than 10 billion dollars and constitute a growing portion of Canada's 400,000 cubic metres of crude oil and natural gas liquids per day production. The booklet explains the importance of the offshore oil and natural gas industry to Canada, the benefits accruing to the maritime provinces locally, prospects for future offshore oil and natural gas development and provides a brief summary of each of the four current major projects. The booklet also provides an overview of the facilities required for offshore energy projects, environmental impacts and safeguards, exploration, drilling, production, processing and transportation aspects of offshore oil and gas projects. 9 refs, photos

  11. A new understanding of inert gas narcosis

    International Nuclear Information System (INIS)

    Zhang Meng; Gao Yi; Fang Haiping

    2016-01-01

    Anesthetics are extremely important in modern surgery to greatly reduce the patient’s pain. The understanding of anesthesia at molecular level is the preliminary step for the application of anesthetics in clinic safely and effectively. Inert gases, with low chemical activity, have been found to cause anesthesia for centuries, but the mechanism is unclear yet. In this review, we first summarize the progress of theories about general anesthesia, especially for inert gas narcosis, and then propose a new hypothesis that the aggregated rather than the dispersed inert gas molecules are the key to trigger the narcosis to explain the steep dose-response relationship of anesthesia. (topical review)

  12. Experiments with background gas in a vacuum arc centrifuge

    International Nuclear Information System (INIS)

    Dallaqua, R.S.; Simpson, S.W.; Del Bosco, E.

    1996-01-01

    Since promising isotope separation results were first reported by Krishnan et al. in 1981, a range of vacuum arc centrifuge experiments have been conducted in laboratories around the world. The PCEN (Plasma CENtrifuge) vacuum arc centrifuge at the Brazilian National Institute for Space Research has been used for isotope separation studies with cathode materials of carbon and magnesium and also to investigate the performance in terms of the rotational velocity attained for different cathode materials. Here, a vacuum arc centrifuge has been operated with an initial filling gas of either argon or hydrogen for pressures ranging from 10 -3 to 10 -1 Pa. The angular velocity ω of the plasma has been determined by cross-correlating the signals from potential probes, and the electron temperature T has been deduced from Langmuir probe data. At high gas pressures and early times during the 14 ms plasma lifetime, high-frequency nonuniformities frequently observed in the vacuum discharge disappear, suggesting that the associated instability is suppressed. Under the same conditions, nonuniformities rotating with much lower angular velocities are observed in the plasma. Temperatures are reduced in the presence of the background gas, and the theoretical figure of merit for separation proportional to ω 2 /T is increased compared to its value in the vacuum discharge for both argon and hydrogen gas fillings

  13. Gas cooled fast reactor background, facilities, industries and programmes

    International Nuclear Information System (INIS)

    Dalle Donne, M.

    1980-05-01

    This report was prepared at the request of the OECD-NEA Coordinating Group on Gas Cooled Fast Reactor Development and it represents a contribution (Vol.II) to the jointly sponsored Vol.I (GCFR Status Report). After a chapter on background with a brief description of the early studies and the activities in the various countries involved in the collaborative programme (Austria, Belgium, France, Germany, Japan, Sweden, Switzerland, United Kingdom and United States), the report describes the facilities available in those countries and at the Gas Breeder Reactor Association and the industrial capabilities relevant to the GCFR. Finally the programmes are described briefly with programme charts, conclusions and recommendations are given. (orig.) [de

  14. Generalized Chaplygin gas and cosmic microwave background radiation constraints

    International Nuclear Information System (INIS)

    Bento, M.C.; Bertolami, O.; Sen, A.A.

    2003-01-01

    We study the dependence of the location of the cosmic microwave background radiation peaks on the parameters of the generalized Chaplygin gas model, whose equation of state is given by p=-A/ρ α , where A is a positive constant and 0<α≤1. We find, in particular, that observational data arising from Archeops, BOOMERANG, supernova and high-redshift observations allow constraining significantly the parameter space of the model. Our analysis indicates that the emerging model is clearly distinguishable from the α=1 Chaplygin case and the ΛCDM model

  15. Measuring and understanding total dissolved gas pressure in groundwater

    Science.gov (United States)

    Ryan, C.; Roy, J. W.; Randell, J.; Castellon, L.

    2009-05-01

    Since dissolved gases are important to a number of aspects of groundwater (e.g. age dating, active or passive bioremediation, greenhouse gas fluxes, understanding biogeochemical processes involving gases, assessing potential impacts of coal bed methane activities), accurate concentration measurements, and understanding of their subsurface behaviour are important. Researchers have recently begun using total dissolved gas pressure (TGP) sensor measurements, more commonly applied for surface water monitoring, in concert with gas composition analyses to estimate more accurate groundwater gas concentrations in wells. We have used hydraulic packers to isolate the well screens where TDP is being measured, and pump tests to indicate that in-well degassing may reduce TDG below background groundwater levels. Thus, in gas-charged groundwater zones, TGPs can be considerably underestimated in the absence of pumping or screen isolation. We have also observed transient decreased TGPs during pumping that are thought to result from ebullition induced when the water table or water level in the well is lowered below a critical hydrostatic pressure.

  16. Gas purity analytics, calibration studies, and background predictions towards the first results of XENON1T

    Energy Technology Data Exchange (ETDEWEB)

    Hasterok, Constanze

    2017-10-25

    The XENON1T experiment aims at the direct detection of the well motivated dark matter candidate of weakly interacting massive particles (WIMPs) scattering off xenon nuclei. The first science run of 34.2 live days has already achieved the most stringent upper limit on spin-independent WIMP-nucleon cross-sections above masses of 10 GeV with a minimum of 7.7.10{sup -47} cm{sup 2} at a mass of 35 GeV. Crucial for this unprecedented sensitivity are a high xenon gas purity and a good understanding of the background. In this work, a procedure is described that was developed to measure the purity of the experiment's xenon inventory of more than three tons during its initial transfer to the detector gas system. The technique of gas chromatography has been employed to analyze the noble gas for impurities with the focus on oxygen and krypton contaminations. Furthermore, studies on the calibration of the experiment's dominating background induced by natural gamma and beta radiation were performed. Hereby, the novel sources of radioactive isotopes that can be dissolved in the xenon were employed, namely {sup 220}Rn and tritium. The sources were analyzed in terms of a potential impact on the outcome of a dark matter search. As a result of the promising findings for {sup 220}Rn, the source was successfully deployed in the first science run of XENON1T. The first WIMP search of XENON1T is outlined in this thesis, in which a background component from interactions taking place in close proximity to the detector wall is identified, investigated and modeled. A background prediction was derived that was incorporated into the background model of the WIMP search which was found to be in good agreement with the observation.

  17. Rotation of a magnesium plasma column in a background gas

    International Nuclear Information System (INIS)

    Bosco, E. Del; Dallaqua, R.S.

    1993-01-01

    Measurements of the angular velocity of a plasma column in a surrounding gas atmosphere are presented. The plasma is produced by a pulsed, high current arc discharge in the presence of an axial magnetic field. The angular velocity is measured using the cross correlation technique applied to the floating potential signals measured by two Langmuir probes. The main result is that when gas is added to the discharge the angular velocity is always lower than the case when there is no gas, this effect been more pronounced in the beginning of the discharge. For pressures higher than ∼ 2 x 10 -2 Pa there is a effect of the gas on the plasma column rotation and the angular velocity diminishes even at the end of discharge. (author)

  18. Germany 2050 a greenhouse gas-neutral country. Background paper

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kathrin; Nissler, Diana (eds.)

    2013-10-15

    For several years, the German Federal Environment Agency (UBA) has been looking at the question how the climate target of a GHG-neutral Germany can be achieved. In a multi-disciplinary project launched by the agency, the first point of call was power generation because of its high emissions. It was shown in 2010 that power generation from 100 % renewable energy is possible. Even then it was understood that a renewable energy supply alone would not be enough to completely abolish greenhouse gas emissions. Other sectors of the economy would have to follow suit and undergo major changes, relying on low-GHG technology. Consequently, the study now submitted, ''Greenhouse gas-neutral Germany 2050'', includes in its research all relevant emission sources that are described in the annual National Inventory Report (NIR) on emissions and removal of greenhouse gases. Alongside complete energy supply, including heating and transport, we also look at emissions from industry, waste disposal, agriculture and forestry as well as changes in land use. We develop a target scenario. The transformations that lead to the target and related economic considerations or the selection of appropriate policy instruments, however, are not part of our study. The scenario analysis is based on the assumption that in 2050, Germany will still be an exporting industrial country with an average annual growth of 0.7 % of its gross domestic product.

  19. Understanding NaI(Tl) crystal background for dark matter searches

    Energy Technology Data Exchange (ETDEWEB)

    Adhikari, G.; Adhikari, P.; Kong, S.Y.; Oh, S.Y. [Sejong University, Department of Physics and Astronomy, Seoul (Korea, Republic of); Ha, C.; Jeon, E.J.; Kim, N.Y.; Lee, H.S.; Park, J.S.; Park, K.S. [Institute for Basic Science (IBS), Center for Underground Physics, Daejeon (Korea, Republic of); Kim, Y.D. [Institute for Basic Science (IBS), Center for Underground Physics, Daejeon (Korea, Republic of); Sejong University, Department of Physics and Astronomy, Seoul (Korea, Republic of)

    2017-07-15

    We have developed ultra-low-background NaI(Tl) crystals to reproduce the DAMA results with the ultimate goal of achieving purity levels that are comparable to or better than those of the DAMA/LIBRA crystals. Even though the achieved background level does not approach that of DAMA/LIBRA, it is crucial to have a quantitative understanding of the backgrounds. We have studied background simulations toward a deeper understanding of the backgrounds and developed background models for a 9.16-kg NaI(Tl) crystal used in the test arrangement. In this paper we describe the contributions of background sources quantitatively by performing Geant4 Monte Carlo simulations that are fitted to the measured data to quantify the unknown fractions of the background compositions. In the fitted results, the overall simulated background spectrum well describes the measured data with a 9.16-kg NaI(Tl) crystal and shows that the background sources are dominated by surface {sup 210}Pb and internal {sup 40}K in the 2-6-keV energy interval, which produce 2.4 counts/day/keV/kg (dru) and 0.5 dru, respectively. (orig.)

  20. The effect of background music and song texts on the emotional understanding of children with autism.

    Science.gov (United States)

    Katagiri, June

    2009-01-01

    The purpose of this study was to examine the effect of background music and song texts to teach emotional understanding to children with autism. Participants were 12 students (mean age 11.5 years) with a primary diagnosis of autism who were attending schools in Japan. Each participant was taught four emotions to decode and encode: happiness, sadness, anger, and fear by the counterbalanced treatment-order. The treatment consisted of the four conditions: (a) no contact control (NCC)--no purposeful teaching of the selected emotion, (b) contact control (CC)--teaching the selected emotion using verbal instructions alone, (c) background music (BM)--teaching the selected emotion by verbal instructions with background music representing the emotion, and singing songs (SS)--teaching the selected emotion by singing specially composed songs about the emotion. Participants were given a pretest and a posttest and received 8 individual sessions between these tests. The results indicated that all participants improved significantly in their understanding of the four selected emotions. Background music was significantly more effective than the other three conditions in improving participants' emotional understanding. The findings suggest that background music can be an effective tool to increase emotional understanding in children with autism, which is crucial to their social interactions.

  1. Analysis of local-scale background concentrations of methane and other gas-phase species in the Marcellus Shale

    Directory of Open Access Journals (Sweden)

    J. Douglas Goetz

    2017-02-01

    Full Text Available The Marcellus Shale is a rapidly developing unconventional natural gas resource found in part of the Appalachian region. Air quality and climate concerns have been raised regarding development of unconventional natural gas resources. Two ground-based mobile measurement campaigns were conducted to assess the impact of Marcellus Shale natural gas development on local scale atmospheric background concentrations of air pollution and climate relevant pollutants in Pennsylvania. The first campaign took place in Northeastern and Southwestern PA in the summer of 2012. Compounds monitored included methane (CH4, ethane, carbon monoxide (CO, nitrogen dioxide, and Proton Transfer Reaction Mass Spectrometer (PTR-MS measured volatile organic compounds (VOC including oxygenated and aromatic VOC. The second campaign took place in Northeastern PA in the summer of 2015. The mobile monitoring data were analyzed using interval percentile smoothing to remove bias from local unmixed emissions to isolate local-scale background concentrations. Comparisons were made to other ambient monitoring in the Marcellus region including a NOAA SENEX flight in 2013. Local background CH4 mole fractions were 140 ppbv greater in Southwestern PA compared to Northeastern PA in 2012 and background CH4 increased 100 ppbv from 2012 to 2015. CH4 local background mole fractions were not found to have a detectable relationship between well density or production rates in either region. In Northeastern PA, CO was observed to decrease 75 ppbv over the three year period. Toluene to benzene ratios in both study regions were found to be most similar to aged rural air masses indicating that the emission of aromatic VOC from Marcellus Shale activity may not be significantly impacting local background concentrations. In addition to understanding local background concentrations the ground-based mobile measurements were useful for investigating the composition of natural gas emissions in the region.

  2. 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.)

  3. LHCb: Beam-gas background for LHCb at 3.5 TeV

    CERN Multimedia

    Brett, D R; Corti, G; Alessio, F; Jacobsson, R; Talanov, V; Lieng, M H

    2011-01-01

    We consider the machine induced backgrounds for LHCb arising from collisions of the beam with residual gas in the long straight sections of the LHC close to the experiment. We concentrate on the background particle fluxes initiated by inelastic beam-gas interactions with a direct line of sight to the experiment, with the potential impact on the experiment increasing for larger beam currents and changing gas pressures. In this paper we calculate the background rates for parameters foreseen with LHC running in 2011, using realistic residual pressure profiles. We also discuss the effect of using a pressure profile formulated in terms of equivalent hydrogen, through weighting of other residual gases by their cross section, upon the radial fluxes from the machine and the detector response. We present the expected rates and the error introduced through this approximation.

  4. Numerical modeling of plasma plume evolution against ambient background gas in laser blow off experiments

    International Nuclear Information System (INIS)

    Patel, Bhavesh G.; Das, Amita; Kaw, Predhiman; Singh, Rajesh; Kumar, Ajai

    2012-01-01

    Two dimensional numerical modelling based on simplified hydrodynamic evolution for an expanding plasma plume (created by laser blow off) against an ambient background gas has been carried out. A comparison with experimental observations shows that these simulations capture most features of the plasma plume expansion. The plume location and other gross features are reproduced as per the experimental observation in quantitative detail. The plume shape evolution and its dependence on the ambient background gas are in good qualitative agreement with the experiment. This suggests that a simplified hydrodynamic expansion model is adequate for the description of plasma plume expansion.

  5. Background and Effects of Deepening Reform of the Oil and Gas Industry System

    Institute of Scientific and Technical Information of China (English)

    Wang Zhen

    2017-01-01

    Under the background of a fourth wave of industrial revolution and a period of worldwide energy transformation,deepening the reforms in the oil and gas industry system is of great significance.After reviewing the achievements and summarizing the problems of the oil and gas industry in China,this paper lays emphasis on the key aspects of this new round of deepening reforms,and holds the position that this reform,based on the implementation of the national energy strategy,covers the entire oil and gas industry chain by liberalizing market access,reforming market mechanisms,and strengthening management.The reform will bring far-reaching effects upon the entire chain and the participants of the oil and gas industry.It wilt help to improve the market-oriented allocation of resources,allow enterprises to interact as competitors,and enhance the national oil and gas security.

  6. Understanding Gas-Phase Ammonia Chemistry in Protoplanetary Disks

    Science.gov (United States)

    Chambers, Lauren; Oberg, Karin I.; Cleeves, Lauren Ilsedore

    2017-01-01

    Protoplanetary disks are dynamic regions of gas and dust around young stars, the remnants of star formation, that evolve and coagulate over millions of years in order to ultimately form planets. The chemical composition of protoplanetary disks is affected by both the chemical and physical conditions in which they develop, including the initial molecular abundances in the birth cloud, the spectrum and intensity of radiation from the host star and nearby systems, and mixing and turbulence within the disk. A more complete understanding of the chemical evolution of disks enables a more complete understanding of the chemical composition of planets that may form within them, and of their capability to support life. One element known to be essential for life on Earth is nitrogen, which often is present in the form of ammonia (NH3). Recent observations by Salinas et al. (2016) reveal a theoretical discrepancy in the gas-phase and ice-phase ammonia abundances in protoplanetary disks; while observations of comets and protostars estimate the ice-phase NH3/H2O ratio in disks to be 5%, Salinas reports a gas-phase NH3/H2O ratio of ~7-84% in the disk surrounding TW Hydra, a young nearby star. Through computational chemical modeling of the TW Hydra disk using a reaction network of over 5000 chemical reactions, I am investigating the possible sources of excess gas-phase NH3 by determining the primary reaction pathways of NH3 production; the downstream chemical effects of ionization by ultraviolet photons, X-rays, and cosmic rays; and the effects of altering the initial abundances of key molecules such as N and N2. Beyond providing a theoretical explanation for the NH3 ice/gas discrepancy, this new model may lead to fuller understanding of the gas-phase formation processes of all nitrogen hydrides (NHx), and thus fuller understanding of the nitrogen-bearing molecules that are fundamental for life as we know it.

  7. Examination of background contamination levels for gas counting and AMS target preparation in Trondheim

    DEFF Research Database (Denmark)

    Gulliksen, S.; Thomsen, M.S.

    1992-01-01

    conventional gas proportional counting (GPC) system. We have also studied contamination levels of our target preparation for C-14 accelerator mass spectrometry (AMS) dating in Uppsala. A significant lower background is obtained for Icelandic double spar than for marbles, probably due to a crystal structure...

  8. Understanding childhood asthma in focus groups: perspectives from mothers of different ethnic backgrounds

    Directory of Open Access Journals (Sweden)

    McKenzie Sheila

    2001-09-01

    Full Text Available Abstract Background Diagnosing childhood asthma is dependent upon parental symptom reporting but there are problems in the use of words and terms. The purpose of this study was to describe and compare understandings of childhood 'asthma' by mothers from three different ethnic backgrounds who have no personal experience of diagnosing asthma. A better understanding of parents' perceptions of an illness by clinicians should improve communication and management of the illness. Method Sixty-six mothers living in east London describing their ethnic backgrounds as Bangladeshi, white English and black Caribbean were recruited to 9 focus groups. Discussion was semi-structured. Three sessions were conducted with each ethnic group. Mothers were shown a video clip of a boy with audible wheeze and cough and then addressed 6 questions. Sessions were recorded and transcribed verbatim. Responses were compared within and between ethnic groups. Results Each session, and ethnic group overall, developed a particular orientation to the discussion. Some mothers described the problem using single signs, while others imitated the sound or made comparisons to other illnesses. Hereditary factors were recognised by some, although all groups were concerned with environmental triggers. Responses about what to do included 'normal illness' strategies, use of health services and calls for complementary treatment. All groups were concerned about using medication every day. Expectations about the quality of life were varied, with recognition that restrictions may be based on parental beliefs about asthma, rather than asthma itself. Conclusion Information from these focus groups suggests mothers know a great deal about childhood asthma even though they have no personal experience of it. Knowledge of how mothers from these ethnic backgrounds perceive asthma may facilitate doctor – patient communication with parents of children experiencing breathing difficulties.

  9. Measurements of Plasma Expansion due to Background Gas in the Electron Diffusion Gauge Experiment

    International Nuclear Information System (INIS)

    Morrison, Kyle A.; Paul, Stephen F.; Davidson, Ronald C.

    2003-01-01

    The expansion of pure electron plasmas due to collisions with background neutral gas atoms in the Electron Diffusion Gauge (EDG) experiment device is observed. Measurements of plasma expansion with the new, phosphor-screen density diagnostic suggest that the expansion rates measured previously were observed during the plasma's relaxation to quasi-thermal-equilibrium, making it even more remarkable that they scale classically with pressure. Measurements of the on-axis, parallel plasma temperature evolution support the conclusion

  10. Low background gas flow beta counting system [Paper No.:M2

    International Nuclear Information System (INIS)

    Abani, M.C.; Anilkumar, S.; Bhende, D.R.; Krishnan, Narayani; Babu, D.A.R.

    1993-01-01

    It is difficult to count beta samples of low specific activity in conventional types of counting systems which have inherently high background. This is specially true in case of environmental samples. A gas flow type beta counter has been developed which have the twin advantage of high efficiency and low background. This system uses a gas flow type main counter and another gas flow type guard counter working on the same principle in anticoincidence mode. Both counters are operated in G.M. region. With this anticoincidence arrangement and lead shielding of 3 inch, the system has the background of the order of 1 cpm and efficiency of 40% for 40 K beta and 14% for 14 C beta. The electronics developed includes a quenching cum coincidence-anticoincidence unit, EHT and a counter timer. This paper describes in detail the development and operational experience with the system. A number of units are already operational at BARC and at Environmental Survey Laboratories set up by Department of Atomic Energy and at various other institutions. (author). 4 refs., 2 figs

  11. Interpreting the cosmic far-infrared background anisotropies using a gas regulator model

    Science.gov (United States)

    Wu, Hao-Yi; Doré, Olivier; Teyssier, Romain; Serra, Paolo

    2018-04-01

    Cosmic far-infrared background (CFIRB) is a powerful probe of the history of star formation rate (SFR) and the connection between baryons and dark matter across cosmic time. In this work, we explore to which extent the CFIRB anisotropies can be reproduced by a simple physical framework for galaxy evolution, the gas regulator (bathtub) model. This model is based on continuity equations for gas, stars, and metals, taking into account cosmic gas accretion, star formation, and gas ejection. We model the large-scale galaxy bias and small-scale shot noise self-consistently, and we constrain our model using the CFIRB power spectra measured by Planck. Because of the simplicity of the physical model, the goodness of fit is limited. We compare our model predictions with the observed correlation between CFIRB and gravitational lensing, bolometric infrared luminosity functions, and submillimetre source counts. The strong clustering of CFIRB indicates a large galaxy bias, which corresponds to haloes of mass 1012.5 M⊙ at z = 2, higher than the mass associated with the peak of the star formation efficiency. We also find that the far-infrared luminosities of haloes above 1012 M⊙ are higher than the expectation from the SFR observed in ultraviolet and optical surveys.

  12. Detection of hot gas in clusters of galaxies by observation of the microwave background radiation

    International Nuclear Information System (INIS)

    Gull, S.F.; Northover, K.J.E.

    1976-01-01

    It is stated that satellite observations have indicated that many rich clusters are powerful sources of x-rays. This has been interpreted as due to either thermal bremsstrahlung from very hot gas filling the clusters or as inverse Compton scattering of photons by relativistic electrons. Spectral evidence appears to favour a thermal origin for the radiation, implying the existence of large amounts of hot gas. This gas may be a major constituent of the Universe, and independent confirmation of its existence is very important. Observations are here reported of small diminutions in the cosmic microwave background radiation in the direction of several rich clusters of galaxies. This is considered to confirm the existence of large amounts of very hot gas in these clusters and to indicate that the x-radiation is thermal bremsstrahlung and not inverse Compton emission. The observations were made in 1975/1976 using the 25m. telescope at the SRC Appleton Laboratory at a frequency of 10.6 GH2, and details are given of the technique employed. (U.K.)

  13. Hot gas in clusters of galaxies, cosmic microwave background radiation and cosmology

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Presence of the hot (kTe ~ 3 - 10 KeV) rarefied gas in the clusters of galaxies (most massive gravitationally bound objects in the Universe) leads to the appearance of  "shadows"  in the angular distribution of the Cosmic Microwave Background (CMB) Radiation and permits to measure the peculiar velocities of these clusters relative to the unique coordinate frame where CMB is isotropic. I plan to describe the physics leading to these observational effects. Planck spacecraft, ground based South Pole and Atacama Cosmology Telescopes discovered recently more than two thousand of unknown before Clusters of Galaxies at high redshifts detecting these "shadows" and traces of kinematic effect, demonstrating the correlation of the hot gas velocities with mass concentrations on large scales. Giant ALMA interferometer in Atacama desert resolved recently strong shocks between merging clusters of galaxies. Newly discovered clusters of galaxies permit to study the rate of growth of the large scale structur...

  14. Accidental phosgene gas exposure: A review with background study of 10 cases

    Directory of Open Access Journals (Sweden)

    Arvind Kumar Vaish

    2013-01-01

    Full Text Available Here, authors present a review on clinical presentation and management of exposure of phosgene gas after reviewing the literature by searching with keywords phosgene exposure on Google, Cochrane, Embase and PubMed with a background of experience gained from 10 patients who were admitted to our institute after an accidental phosgene exposure in February 2011 nearby a city in India. Phosgene is a highly toxic gas, occupational workers may have accidental exposure. The gas can also be generated inadvertently during fire involving plastics and other chemicals and solvents containing chlorine, which is of concern to emergency responders. Phosgene inhalation may cause initially symptoms of respiratory tract irritation, patients feel fine thereafter, and then die of choking a day later because of build up of fluid in the lungs (delayed onset non-cardiogenic pulmonary edema. Phosgene exposure is associated with significant morbidity and mortality. Patients with a history of exposure should be admitted to the hospital for a minimum of 24 h for observation because of the potential for delayed onset respiratory failure and acute respiratory distress syndrome.

  15. Background Radiance Estimation for Gas Plume Quantification for Airborne Hyperspectral Thermal Imaging

    Directory of Open Access Journals (Sweden)

    Ramzi Idoughi

    2016-01-01

    Full Text Available Hyperspectral imaging in the long-wave infrared (LWIR is a mean that is proving its worth in the characterization of gaseous effluent. Indeed the spectral and spatial resolution of acquisition instruments is steadily decreasing, making the gases characterization increasingly easy in the LWIR domain. The majority of literature algorithms exploit the plume contribution to the radiance corresponding to the difference of radiance between the plume-present and plume-absent pixels. Nevertheless, the off-plume radiance is unobservable using a single image. In this paper, we propose a new method to retrieve trace gas concentration from airborne infrared hyperspectral data. More particularly the outlined method improves the existing background radiance estimation approach to deal with heterogeneous scenes corresponding to industrial scenes. It consists in performing a classification of the scene and then applying a principal components analysis based method to estimate the background radiance on each cluster stemming from the classification. In order to determine the contribution of the classification to the background radiance estimation, we compared the two approaches on synthetic data and Telops Fourier Transform Spectrometer (FTS Imaging Hyper-Cam LW airborne acquisition above ethylene release. We finally show ethylene retrieved concentration map and estimate flow rate of the ethylene release.

  16. Local ISM 3D Distribution and Soft X-ray Background Inferences for Nearby Hot Gas

    Science.gov (United States)

    Puspitarini, L.; Lallement, R.; Snowden, Steven L.; Vergely, J.-L.; Snowden, S.

    2014-01-01

    Three-dimensional (3D) interstellar medium (ISM) maps can be used to locate not only interstellar (IS) clouds, but also IS bubbles between the clouds that are blown by stellar winds and supernovae, and are filled by hot gas. To demonstrate this, and to derive a clearer picture of the local ISM, we compare our recent 3D IS dust distribution maps to the ROSAT diffuse Xray background maps after removal of heliospheric emission. In the Galactic plane, there is a good correspondence between the locations and extents of the mapped nearby cavities and the soft (0.25 keV) background emission distribution, showing that most of these nearby cavities contribute to this soft X-ray emission. Assuming a constant dust to gas ratio and homogeneous 106 K hot gas filling the cavities, we modeled in a simple way the 0.25 keV surface brightness along the Galactic plane as seen from the Sun, taking into account the absorption by the mapped clouds. The data-model comparison favors the existence of hot gas in the solar neighborhood, the so-called Local Bubble (LB). The inferred mean pressure in the local cavities is found to be approx.9,400/cu cm K, in agreement with previous studies, providing a validation test for the method. On the other hand, the model overestimates the emission from the huge cavities located in the third quadrant. Using CaII absorption data, we show that the dust to CaII ratio is very small in those regions, implying the presence of a large quantity of lower temperature (non-X-ray emitting) ionized gas and as a consequence a reduction of the volume filled by hot gas, explaining at least part of the discrepancy. In the meridian plane, the two main brightness enhancements coincide well with the LB's most elongated parts and chimneys connecting the LB to the halo, but no particular nearby cavity is found towards the enhancement in the direction of the bright North Polar Spur (NPS) at high latitude. We searched in the 3D maps for the source regions of the higher energy

  17. Free molecule flow analysis of the interaction of skimming hardware components and background gas with free jets

    International Nuclear Information System (INIS)

    Raghuraman, P.; Bossel, U.

    1974-01-01

    Under conditions typical for the extraction of nozzle beams from free jets the rarefied flow pattern in the expansion chamber containing skimming hardware components and background gas is studied using a free molecule solution to the Boltzmann equation

  18. Low-background measurements of neutron emission from Ti metal in pressurized deuterium gas

    International Nuclear Information System (INIS)

    Menlove, H.O.; Paciotti, M.A.; Claytor, T.N.; Tuggle, D.G.

    1991-01-01

    A wide variety of neutron detector systems have been used at various research facilities to search for anomalous neutron emission from deuterated metals. Some of these detector systems are summarized here together with possible sources of spurious signals from electronic noise. During the past two years, we have performed experiments to measure neutron emission from pressurized D 2 gas mixed with various forms of titanium metal chips and sponge. Details concerning the neutron detectors, experimental procedures, and results have been reported previously. Our recent experiments have focused on increasing the low-level neutron emission and finding a way to trigger the emission. To improve our detection sensitivity, we have increased the shielding in our counting laboratory, changed to low-background 3 He tubes, and set up additional detector systems in deep underground counting stations. This report is an update on this experimental work. 7 refs., 5 figs., 4 tabs

  19. Thermalization of a UV laser ablation plume in a background gas: From a directed to a diffusionlike flow

    DEFF Research Database (Denmark)

    Amoruso, S.; Toftmann, B.; Schou, Jørgen

    2004-01-01

    Combined diagnostic measurements of deposition rates and ion time-of-flight signals have been employed to study the expansion of a laser ablation plume into a background gas. With increasing gas pressure the angular distribution of the collected ablated atoms becomes broader, while the total...

  20. Dimerization Products of Chloroprene are Background Contaminants Emitted from ALTEF (Polyvinylidene Difluoride) Gas Sampling Bags.

    Science.gov (United States)

    Kwak, Jae; Fan, Maomian; Martin, Jennifer A; Ott, Darrin K; Grigsby, Claude C

    2017-01-01

    Gas sampling bags have been used for collecting air samples. Tedlar bags are most commonly used, but bleed background chemicals such as N,N-dimethylacetamide and phenol. It is often necessary to remove the contaminant by flushing the bags with pure nitrogen or air. In this study, we identified four chloroprene dimerization products as background contaminants emitted from ALTEF bags that are made of a proprietary polyvinylidene difluoride (PVDF). No monomer chloroprene was detected in the bags analyzed. All of the dimers gradually increased once bags were filled with nitrogen due to diffusion from the bag surface. Flushing the bags with nitrogen reduced their concentrations, but was not effective for removing the contaminants. When the bags that had been flushed with nitrogen 5 times were left for 24 h, they increased again, indicating that the dimers were constantly emitted from the ALTEF bag surface. To our knowledge, these compounds have never been demonstrated in ALTEF or other PVDF bags. Our finding indicates that ALTEF might be incorporated with Neoprene (chloroprene-based polymer) during its manufacturing process.

  1. Validation of spectroscopic gas analyzer accuracy using gravimetric standard gas mixtures: impact of background gas composition on CO2 quantitation by cavity ring-down spectroscopy

    Science.gov (United States)

    Lim, Jeong Sik; Park, Miyeon; Lee, Jinbok; Lee, Jeongsoon

    2017-12-01

    The effect of background gas composition on the measurement of CO2 levels was investigated by wavelength-scanned cavity ring-down spectrometry (WS-CRDS) employing a spectral line centered at the R(1) of the (3 00 1)III ← (0 0 0) band. For this purpose, eight cylinders with various gas compositions were gravimetrically and volumetrically prepared within 2σ = 0.1 %, and these gas mixtures were introduced into the WS-CRDS analyzer calibrated against standards of ambient air composition. Depending on the gas composition, deviations between CRDS-determined and gravimetrically (or volumetrically) assigned CO2 concentrations ranged from -9.77 to 5.36 µmol mol-1, e.g., excess N2 exhibited a negative deviation, whereas excess Ar showed a positive one. The total pressure broadening coefficients (TPBCs) obtained from the composition of N2, O2, and Ar thoroughly corrected the deviations up to -0.5 to 0.6 µmol mol-1, while these values were -0.43 to 1.43 µmol mol-1 considering PBCs induced by only N2. The use of TPBC enhanced deviations to be corrected to ˜ 0.15 %. Furthermore, the above correction linearly shifted CRDS responses for a large extent of TPBCs ranging from 0.065 to 0.081 cm-1 atm-1. Thus, accurate measurements using optical intensity-based techniques such as WS-CRDS require TPBC-based instrument calibration or use standards prepared in the same background composition of ambient air.

  2. Understanding the petroleum and natural gas regime in Saskatchewan

    International Nuclear Information System (INIS)

    Lothian, E.C.

    1997-01-01

    Some of the legal issues relating to exploring for and operating oil and gas properties in Saskatchewan were discussed. An overview of key legislation was provided. The purpose of the Oil and Gas Conservation Act (OGCA) was explained, i.e., (1) to prevent waste, (2) to regulate all oil and gas operations to maximize ultimate recovery through prudent operations, (3) to allow each owner the opportunity to recover its share of oil or gas from a pool, (4) to develop, protect and conserve Saskatchewan's oil and gas resources, and (5) to protect the environment from the harmful effects of oil and gas operations. Legislation regarding vertical wells, horizontal wells, and horizontal well spacing was reviewed. Similar explanations were provided for the key features of the Petroleum and Natural Gas Regulations, the Freehold Oil and Gas Production Tax Act, the Mineral Taxation Act, the Land Titles Act, and the Builder's Lien Act. Registration issues for Crown and freehold lands, and non-contractual operator's duties were also reviewed. A brief reference was also made to a recent report entitled the 'Saskatchewan External Cost Review' which indicated that Saskatchewan had certain advantages for producing oil and gas compared to Alberta, Manitoba, British Columbia and North Dakota. Unfortunately, the report also indicated that the external costs ( crown royalties, freehold production taxes, income taxes, sales taxes, etc.), were the highest in Saskatchewan of the four jurisdictions reviewed

  3. The Complexity in Defining Leadership: How Gifted Students' Backgrounds Influence Their Understanding of Effective Leadership

    Science.gov (United States)

    Jackson, Shawon; Sakuma, Satoe; DeVol, Purva

    2015-01-01

    There is no universally accepted definition of what it means to be an effective leader. Individuals understand leadership differently based on their own identities and lived experiences. The purpose of this investigation is to determine how one's ethnicity, class, and gender identities influence their understanding of effective leadership,…

  4. Towards a mechanistic understanding of transient fission gas release

    International Nuclear Information System (INIS)

    Matthews, J.R.; Small, G.J.

    1989-01-01

    Recent experimental results on transient fission gas release from oxide fuels are briefly reviewed. These together with associated microstructural observations are compared with the main models for fission gas behaviour. Single gas atom diffusion, bubble migration, heterogeneous percolation and grain boundary sweeping are examined as possible release mechanisms. The role of gas trapping in bubbles and re-solution by irradiation and thermal processes are included in the comparison. As much of the data, and the main range of interest for light water reactor fuels, is for release during mild transients in fuel with a burn-up below 4%, the role of gas retention on grain boundaries is very important and in some cases dominant. The grain boundaries are found to respond very differently to various gas arrival rates and to local temperature conditions. This can lead to early interlinkage and release in some cases, but retention with accompanying large swelling in others. The role of fission products and the local oxygen content of the fuel are found to be important. The effective fuel stoichiometry is likely to change significantly during transients with substantial effects on the transport processes controlling fission gas behaviour. The results of the evaluation of the models are summarized in mechanism maps for intragranular and grain boundary behaviour. (author). 36 refs, 8 figs

  5. Understanding of Neutral Gas Transport in the Alcator C-Mod Tokamak Divertor

    International Nuclear Information System (INIS)

    Stotler, D.P.; Pitcher, C.S.; Boswell, C.J.; LaBombard, B.; Terry, J.L.; Elder, J.D.; Lisgo, S.

    2002-01-01

    A series of experiments on the effect of divertor baffling on the Alcator C-Mod tokamak provides stringent tests on models of neutral gas transport in and around the divertor region. One attractive feature of these experiments is that a trial description of the background plasma can be constructed from experimental measurements using a simple model, allowing the neutral gas transport to be studied with a stand-alone code. The neutral-ion and neutral-neutral elastic scattering processes recently added to the DEGAS 2 Monte Carlo neutral transport code permit the neutral gas flow rates between the divertor and main chamber to be simulated more realistically than before. Nonetheless, the simulated neutral pressures are too low and the deuterium Balmer-alpha emission profiles differ qualitatively from those measured, indicating an incomplete understanding of the physical processes involved in the experiment. Some potential explanations are examined and opportunities for future exploration a re highlighted. Improvements to atomic and surface physics data and models will play a role in the latter

  6. Background gas density and beam losses in NIO1 beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Veltri, P.; Serianni, G. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), C.so Stati Uniti 4, 35127 Padova (Italy); Cavenago, M. [INFN-LNL, v.le dell’Università 2, I-35020 Legnaro (PD) (Italy)

    2016-02-15

    NIO1 (Negative Ion Optimization 1) is a versatile ion source designed to study the physics of production and acceleration of H- beams up to 60 keV. In ion sources, the gas is steadily injected in the plasma source to sustain the discharge, while high vacuum is maintained by a dedicated pumping system located in the vessel. In this paper, the three dimensional gas flow in NIO1 is studied in the molecular flow regime by the Avocado code. The analysis of the gas density profile along the accelerator considers the influence of effective gas temperature in the source, of the gas temperature accommodation by collisions at walls, and of the gas particle mass. The calculated source and vessel pressures are compared with experimental measurements in NIO1 during steady gas injection.

  7. The cosmic microwave background how it changed our understanding of the universe

    CERN Document Server

    Evans, Rhodri

    2015-01-01

    Rhodri Evans tells the story of what we know about the universe, from Jacobus Kapteyn’s Island universe at the turn of the 20th Century, and the discovery by Hubble that the nebulae were external to our own galaxy, through Gamow’s early work on the cosmic microwave background (CMB) and its subsequent discovery by Penzias and Wilson, to modern day satellite-lead CMB research. Research results from the ground-based experiments DASI, BOOMERANG, and satellite missions COBE, WMAP and Planck are explained and interpreted to show how our current picture of the universe was arrived at, and the author looks at the future of CMB research and what we still need to learn. This account is enlivened by Dr Rhodri Evans' personal connections to the characters and places in the story.

  8. Temporal and spatial dynamics of laser-induced aluminum plasma in argon background at atmospheric pressure: Interplay with the ambient gas

    International Nuclear Information System (INIS)

    Ma, Q.L.; Motto-Ros, V.; Lei, W.Q.; Boueri, M.; Bai, X.S.; Zheng, L.J.; Zeng, H.P.; Yu, J.

    2010-01-01

    Laser ablation in background gas implies supplementary complexities with respect to what happens in the vacuum. It is however essential to understand in detail the involved mechanisms for a number of applications requiring the ablation to be performed in an ambient gas at relative high pressure, such as pulsed-laser deposition, or laser-induced breakdown spectroscopy. In this paper, the expansion of a vapor plume ablated from an aluminum target into an argon gas at atmospheric pressure is experimentally investigated using time- and space-resolved emission spectroscopy. The obtained results provide a detailed description of the interplay between the vapor and the gas. The electron density, the temperature and the number densities (and therefore the partial pressures) of aluminum vapor and argon gas have been measured in and surrounding the vapor plume. Our observations show a confinement of the vapor plume by the gas, which is expected as predicted by the usual hydrodynamics models. The result is a plasma core with quite uniform distributions in electron density, temperature and number densities. Such plasma core presents an ideal emission source for spectroscopic applications. It is however evidenced by our observations that a large amount of argon is mixed into the aluminum plume in the plasma core, which invalidates in the experimental conditions that we used, the hydrodynamic 'piston' model where the background gas is pushed out by the shock wave surrounding the vapor plume. Instead, other mechanisms such as laser-supported detonation wave should play important roles in the early stage of the expansion of the plasma for the determination of its morphology at longer delays.

  9. SPHEREx: Understanding the Origin and Evolution of Galaxies Through the Extragalactic Background Light

    Science.gov (United States)

    Zemcov, Michael; SPHEREx Science Team

    2018-01-01

    The near IR extragalactic background light (EBL) encodes the integrated light production over cosmic history, so traces the total emission from all galaxies along the line of sight up to the ancient first-light objects responsible for the epoch of reionization (EOR). The EBL can be constrained through measurements of anisotropies, taking advantage of the fact that extragalactic populations produce fluctuations with distinct spatial and spectral characteristics from local foregrounds. In particular, EBL anisotropies trace the underlying clustering of faint emission sources, such as stars, galaxies and accreting black holes present during the EOR, dwarf galaxies, and intra-halo light (IHL), all of which are components not readily detected in point source surveys. The fluctuation amplitude observed independently by a number of recent measurements exceeds that expected from the large-scale clustering of known galaxy populations, indicating the presence of a large integrated brightness from these faint and diffuse components. Improved large-area measurements covering the entire near-IR are required to constrain the possible models for the history of emission from stars back to the EOR.SPHEREx brings new capabilities to EBL fluctuation measurements, employing 96 spectral channels covering 0.75 to 5 microns with spectral resolving power R = 41 to 135 that enable SPHEREx to carry out a multi-frequency separation of the integrated light from galaxies, IHL, and EOR components using the rich auto- and cross-correlation information available from two 45 square degree surveys of the ecliptic poles. SPHEREx is an ideal intensity mapping machine, and has the sensitivity to disentangle the history of light production associated with EBL fluctuations. SPHEREx will search for an EOR component its to minimum required level through component separation and spectral fitting techniques optimized for the near-IR. In addition to broad-band intensity mapping that enhances and extends the

  10. Process, background and design criteria of the gas cleaning at Puertollano IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Pisa, J. [Elcogas, Madrid (Spain)

    1998-11-01

    The Puertollano IGCC plant selected cooling by a water-tube boiler with upstream quenching at high velocities that requires a dust-free cooling gas at not less than 250{degree}C in order not to penalise the heat recovery efficiency. A filtration system for gas dedusting in the 250{degree}C temperature range has been installed and will be commissioned at the end of 1997. The gas cleaning concept is completed with a Venturi Scrubber, a COS hydrolysis reactor and a MDEA column to strip the sulphuric acid to yield clean gas. The gasification island is based upon the PRENFLO system which is an entrained-flow system with dry feeding. The selection of the filter system arrangement considered the limited operational experience in comparable operating conditions and acknowledged the flexibility of the filter system versus the cyclone-scrubber as far as easier load variation operation, the reduction of residues needing deposition and increased slag flow, as well as easier maintenance. Additionally to the ceramic test filters in Furstenhausen (PRENFLO) and Deer Park near Houston (SHELL), ceramic candle-type filter were selected in Buggenum and at Wabash River, and for the KoBra plant. The main criteria for the selection of the filter system and the type of candle were: separation efficiency to match clean gas limits; uniform distribution of the dust-laden gas to the filters; wear-resistant routing of the dust-laden gas flow; need for a supporting structure which must cope with sudden pressure fluctuations; optimised pulse gas system; and maintenance and repair. Based upon the above criteria, the PRENFLO concept requirements and the gas turbine specification, an arrangement with two pressure filter vessels with LLB design and filter elements manufactured by Schumacher has been installed in Puertollano. 2 figs., 3 tabs.

  11. Influence of the atomic mass of the background gas on laser ablation plume propagation

    DEFF Research Database (Denmark)

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

    2008-01-01

    A combination of time-of-flight ion probe measurements and gas dynamical modeling has been used to investigate the propagation of a laser ablation plume in gases of different atomic/molecular weight. The pressure variation of the ion time-of-flight was found to be well described by the gas...... dynamical model of Predtechensky and Mayorov (Appl. Supercond. 1:2011, 1993). In particular, the model describes how the pressure required to stop the plume in a given distance depends on the atomic/molecular weight of the gas, which is a feature that cannot be explained by standard point......-blast-wave descriptions of laser ablation plume expansion in gas....

  12. The oil and gas industry and the Canadian economy: a backgrounder

    International Nuclear Information System (INIS)

    1999-06-01

    The technological and economic significance of the Canadian petroleum industry to the national economy and to Canada's standing in the world are reviewed. The six key ways in which the oil and gas industry affects Canada, namely employment, balance of trade, products, government revenues, international technology trade and community support are stressed within the context of describing present and future oil and gas resources, Canada's petroleum and natural gas trade balance, and capital spending and product sales. Attention is also drawn to the role of the Canadian petroleum and natural gas industry as a producer and exporter of world class technology, especially in the areas of high tech exploration methods, cold-climate and offshore operations, enhanced recovery techniques, heavy oil production and and processing, mining and upgrading of oil sands bitumen, oil well firefighting, and environmental protection technology. maps, figs

  13. Analysis of senior high school student understanding on gas kinetic theory material

    Science.gov (United States)

    Anri, Y.; Maknun, J.; Chandra, D. T.

    2018-05-01

    The purpose of this research conducted to find out student understanding profile about gas kinetic theory. Particularly, on ideal gas law material, ideal gas equations and kinetic energy of ideal gas. This research was conducted on student of class XII in one of the schools in Bandung. This research is a descriptive research. The data of this research collected by using test instrument which was the essay that has been developed by the researcher based on Bloom’s Taxonomy revised. Based on the analysis result to student answer, this research discovered that whole student has low understanding in the material of gas kinetic theory. This low understanding caused of the misconception of the student, student attitude on physic subjects, and teacher teaching method who are less helpful in obtaining clear pictures in material being taught.

  14. Digital pulse-shape discrimination applied to an ultra-low-background gas-proportional counting system. First results

    International Nuclear Information System (INIS)

    Aalseth, C.E.; Day, A.R.; Fuller, E.S.; Hoppe, E.W.; Keillor, M.E.; Mace, E.K.; Myers, A.W.; Overman, C.T.; Panisko, M.E.; Seifert, A.

    2013-01-01

    A new ultra-low-background proportional counter design was recently developed at Pacific Northwest National Laboratory (PNNL). This design, along with an ultra-low-background counting system which provides passive and active shielding with radon exclusion, has been developed to complement a new shallow underground laboratory (∼30 m water-equivalent) constructed at PNNL. After these steps to mitigate dominant backgrounds (cosmic rays, external gamma-rays, radioactivity in materials), remaining background events do not exclusively arise from ionization of the proportional counter gas. Digital pulse-shape discrimination (PSD) is thus employed to further improve measurement sensitivity. In this work, a template shape is generated for each individual sample measurement of interest, a 'self-calibrating' template. Differences in event topology can also cause differences in pulse shape. In this work, the temporal region analyzed for each event is refined to maximize background discrimination while avoiding unwanted sensitivity to event topology. This digital PSD method is applied to sample and background data, and initial measurement results from a biofuel methane sample are presented in the context of low-background measurements currently being developed. (author)

  15. Overview: Understanding nucleation phenomena from simulations of lattice gas models

    International Nuclear Information System (INIS)

    Binder, Kurt; Virnau, Peter

    2016-01-01

    Monte Carlo simulations of homogeneous and heterogeneous nucleation in Ising/lattice gas models are reviewed with an emphasis on the general insight gained on the mechanisms by which metastable states decay. Attention is paid to the proper distinction of particles that belong to a cluster (droplet), that may trigger a nucleation event, from particles in its environment, a problem crucial near the critical point. Well below the critical point, the lattice structure causes an anisotropy of the interface tension, and hence nonspherical droplet shapes result, making the treatment nontrivial even within the conventional classical theory of homogeneous nucleation. For temperatures below the roughening transition temperature facetted crystals rather than spherical droplets result. The possibility to find nucleation barriers from a thermodynamic analysis avoiding a cluster identification on the particle level is discussed, as well as the question of curvature corrections to the interfacial tension. For the interpretation of heterogeneous nucleation at planar walls, knowledge of contact angles and line tensions is desirable, and methods to extract these quantities from simulations will be mentioned. Finally, also the problem of nucleation near the stability limit of metastable states and the significance of the spinodal curve will be discussed, in the light of simulations of Ising models with medium range interactions.

  16. Siting Background Towers to Characterize Incoming Air for Urban Greenhouse Gas Estimation: A Case Study in the Washington, DC/Baltimore Area

    Science.gov (United States)

    Mueller, K.; Yadav, V.; Lopez-Coto, I.; Karion, A.; Gourdji, S.; Martin, C.; Whetstone, J.

    2018-03-01

    There is increased interest in understanding urban greenhouse gas (GHG) emissions. To accurately estimate city emissions, the influence of extraurban fluxes must first be removed from urban greenhouse gas (GHG) observations. This is especially true for regions, such as the U.S. Northeastern Corridor-Baltimore/Washington, DC (NEC-B/W), downwind of large fluxes. To help site background towers for the NEC-B/W, we use a coupled Bayesian Information Criteria and geostatistical regression approach to help site four background locations that best explain CO2 variability due to extraurban fluxes modeled at 12 urban towers. The synthetic experiment uses an atmospheric transport and dispersion model coupled with two different flux inventories to create modeled observations and evaluate 15 candidate towers located along the urban domain for February and July 2013. The analysis shows that the average ratios of extraurban inflow to total modeled enhancements at urban towers are 21% to 36% in February and 31% to 43% in July. In July, the incoming air dominates the total variability of synthetic enhancements at the urban towers (R2 = 0.58). Modeled observations from the selected background towers generally capture the variability in the synthetic CO2 enhancements at urban towers (R2 = 0.75, root-mean-square error (RMSE) = 3.64 ppm; R2 = 0.43, RMSE = 4.96 ppm for February and July). However, errors associated with representing background air can be up to 10 ppm for any given observation even with an optimal background tower configuration. More sophisticated methods may be necessary to represent background air to accurately estimate urban GHG emissions.

  17. Energy balance of a laser ablation plume expanding in a background gas

    DEFF Research Database (Denmark)

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

    2010-01-01

    The energy balance of a laser ablation plume in an ambient gas for nanosecond pulses has been investigated on the basis of the model of Predtechensky and Mayorov (PM), which provides a relatively simple and clear description of the essential hydrodynamics. This approach also leads to an insightfu...

  18. Laser induced aluminiun plasma analysis by optical emission spectroscopy in a nitrogen background gas

    International Nuclear Information System (INIS)

    Chamorro, J C; Uzuriaga, J; Riascos, H

    2012-01-01

    We studied an Al plasma generated by a Nd:YAG laser with a laser fluence of 4 J/cm 2 , a wavelength of 1064 nm, energy pulse of 500 mJ and 10 Hz repetition rate. We studied their spectral characteristics at various ambient nitrogen pressures by optical emission spectroscopy (OES). The N 2 gas pressure was varied from 20 mTorr to 150 mTorr. In Al plume, both atomic and ionic spectra were observed. The electron temperature and electron number density of the plume as of the function ambient gas pressure were determined. The electron temperature was calculated by using the Boltzmann-plot method and the number density was calculated considering the stark effect as dominating on the emission lines.

  19. The oil and gas industry and the Canadian economy: a backgrounder

    International Nuclear Information System (INIS)

    Curran, R.

    2000-02-01

    The impact of the oil and natural gas industry on the Canadian economy is explained in terms of employment, balance of trade, products, government revenues, international technology trade and industry support to the community. It is reported that the industry employs almost one half million people in Canada; is the second largest contributor to Canada's balance of trade; generate billions of dollars for the economy and pays hundreds of millions of dollars in taxes and its employees contribute millions of dollars and thousands of hours of time to charitable and community organizations. The industry is also one of the major contributors to Canada's technology export through its leadership in high technology exploration methods, cold climate and offshore operations, enhanced recovery technologies, producing and processing heavy oil; mining and upgrading oil sands bitumen, oil-well firefighting techniques and environmental protection technologies, among others. Citing Canada's cold climate and energy-intensive industries, hence the need for large quantities of energy, the booklet offers a rationale for the industry's need to continue to be profitable in order to develop new sources of oil and gas production and invest in energy-efficient technologies. Assuming continued profitability, combined with more efficient use of oil and gas, the Foundation remains confident that the industry will provide energy security and export revenues for the benefit of all Canadians. 12 refs., photos

  20. The second generation model of greenhouse gas emissions: background and initial development

    International Nuclear Information System (INIS)

    Baron, R.; Wise, M.A.; Edmonds, J.A.; Pitcher, H.M.; Barns, D.

    1992-01-01

    The analysis of greenhouse gas emissions has made enormous progress during the course of the past decade. We have progressed from the use of simple time-trend extrapolations to the analysis of emissions of several greenhouse gases with parallel but independent behavioral and optimization models of energy, manufacturing, agriculture, and land-use systems. But our ability to examine potential future scenarios of greenhouse gas emissions is limited because modeling tools adequate to the task of integrating analyses of technologies and human activities on a global scale with regional detail, including energy production and consumption, agriculture, manufacture, capital formation, and land-use, along with the interdependencies between these categories, do not yet exist. The first generation of models were specialty models which focused on a particular aspect of the emissions problem without regard to how that activity interacted with other human and natural activities. The natural science pertaining to greenhouse warming now emphasizes the variety of gases associated with potential changes in the radiative composition of the atmosphere: CO 2 , CH 4 , CO, N 2 O, NO x , SO 2 , VOC's, chlorofluorocarbons, (CFC's) and CFC substitutes. Human activities generating the emissions of these gases are interdependent; actions taken to limit emissions from one segment of the economy will affect other segments of the economy. Policy issues such as the recycling of revenues from a carbon tax, land-use changes due to to tree-planting to sequestrate carbon dioxide or extensive development of biomass energy resources, require a more comprehensive modeling approach in which the relationship between technology, institutions, land use, economics and human activity is explicitly represented. The purpose of this paper is to describe briefly the design of a model which is capable of addressing greenhouse gas emissions and the consequences of alternative policy options. 7 refs

  1. Planning of in-situ experiment for understanding of gas migration behaviour in sedimentary rock. (1) Setting of gas injection procedure

    International Nuclear Information System (INIS)

    Tanai, Kenji; Fujita, Tomoo; Noda, Masaru; Yamamoto, Shuichi; Shimura, Tomoyuki; Sato, Shin

    2013-01-01

    Japan Atomic Energy Agency has been planning in-situ gas migration test in Horonobe URL, Hokkaido. This paper discusses the optimum gas injection procedure for the test to understand gas migration behaviour in surrounded rock. The stepwise constant gas injection was selected, taking into account domestic and overseas gas related research results. Hydro-mechanical-gas coupling analysis which is able to consider the dissolved methane in Horonobe groundwater was applied to evaluate the gas behaviour. The results have indicated no significant mechanical damages to the rock and have supported the appropriateness of selected gas injection procedure for the test. (author)

  2. New method of 85Kr reduction in a noble gas based low-background detector

    Science.gov (United States)

    Akimov, D. Yu.; Bolozdynya, A. I.; Burenkov, A. A.; Hall, C.; Kovalenko, A. G.; Kuzminov, V. V.; Simakov, G. E.

    2017-04-01

    Krypton-85 is an anthropogenic beta-decaying isotope which produces low energy backgrounds in dark matter and neutrino experiments, especially those based upon liquid xenon. Several technologies have been developed to reduce the Kr concentration in such experiments. We propose to augment those separation technologies by first adding to the xenon an 85Kr-free sample of krypton in an amount much larger than the natural krypton that is already present. After the purification system reduces the total Kr concentration to the same level, the final 85Kr concentration will be reduced even further by the dilution factor. A test cell for measurement of the activity of various Kr samples has been assembled, and the activity of 25-year-old krypton has been measured. The measured activity agrees well with the expected activity accounting for the 85Kr abundance of the earth's atmosphere in 1990 and the half-life of the isotope. Additional tests with a Kr sample produced in the year 1944 (before the atomic era) have been done in order to demonstrate the sensitivity of the test cell.

  3. New method of 85Kr reduction in a noble gas based low-background detector

    International Nuclear Information System (INIS)

    Akimov, D.Yu.; Burenkov, A.A.; Kovalenko, A.G.; Simakov, G.E.; Bolozdynya, A.I.; Hall, C.; Kuzminov, V.V.

    2017-01-01

    Krypton-85 is an anthropogenic beta-decaying isotope which produces low energy backgrounds in dark matter and neutrino experiments, especially those based upon liquid xenon. Several technologies have been developed to reduce the Kr concentration in such experiments. We propose to augment those separation technologies by first adding to the xenon an 85 Kr-free sample of krypton in an amount much larger than the natural krypton that is already present. After the purification system reduces the total Kr concentration to the same level, the final 85 Kr concentration will be reduced even further by the dilution factor. A test cell for measurement of the activity of various Kr samples has been assembled, and the activity of 25-year-old krypton has been measured. The measured activity agrees well with the expected activity accounting for the 85 Kr abundance of the earth's atmosphere in 1990 and the half-life of the isotope. Additional tests with a Kr sample produced in the year 1944 (before the atomic era) have been done in order to demonstrate the sensitivity of the test cell.

  4. Compton scattering of microwave background radiation by gas in galaxy clusters

    International Nuclear Information System (INIS)

    Gould, R.J.; Rephaeli, Y.

    1978-01-01

    Based on data on the X-ray spectrum of the Coma cluster, interpreted as thermal bremsstrahlung, the expected brightness depletion from Compton scattering of the microwave background in the direction of the cluster is computed. The calculated depletion is about one-third that recently observed by Gull and Northover, and the discrepancy is discussed. In comparing the observed microwave depletion in the direction of other clusters which are X-ray sources it is found that there is no correlation with the cluster X-ray luminosity, while a dependence proportional to L/sub x//sup 1/2/ is expected. Consequently, the microwave depletion observations cannot yet be taken as good evidence for a thermal bremsstrahlung origin for the X-ray emission. The perturbation from Compton scattering of photons on the high-frequency (Wien) tail of the blackbody distribution is computed and found to be much larger than predicted in previous calculations. In the Wien tail the effect is a relative increase in the blackbody intensity that is appreciably greater in magnitude than the depletion in the Rayleigh-Jeans domain

  5. The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?

    Science.gov (United States)

    Ojeda-G-P, Alejandro; Schneider, Christof W.; Döbeli, Max; Lippert, Thomas; Wokaun, Alexander

    2015-12-01

    In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion. This effect has been mainly reported for vacuum depositions of single element targets and is particularly noticeable when the aspect ratio of the beam spot is large. We investigate the flip-over effect in vacuum and at three relevant background-gas pressures for pulsed laser deposition using a La0.4Ca0.6MnO3 target by measuring the thickness dependence of the deposited material as a function of angle. The film thicknesses and compositions are determined by Rutherford backscattering and argon is used to reduce the influence of additional chemical reactions in the plasma. The results show the prevalence of the flip-over effect for all pressures except for the highest, i.e. 1 × 10-1 mbar, where the film thickness is constant for all angles. The composition profiles show noticeable compositional variations of up to 30% with respect to the target material depending on the background gas pressure, the angular location, and the laser spot dimensions.

  6. Speech understanding in background noise with the two-microphone adaptive beamformer BEAM in the Nucleus Freedom Cochlear Implant System.

    Science.gov (United States)

    Spriet, Ann; Van Deun, Lieselot; Eftaxiadis, Kyriaky; Laneau, Johan; Moonen, Marc; van Dijk, Bas; van Wieringen, Astrid; Wouters, Jan

    2007-02-01

    This paper evaluates the benefit of the two-microphone adaptive beamformer BEAM in the Nucleus Freedom cochlear implant (CI) system for speech understanding in background noise by CI users. A double-blind evaluation of the two-microphone adaptive beamformer BEAM and a hardware directional microphone was carried out with five adult Nucleus CI users. The test procedure consisted of a pre- and post-test in the lab and a 2-wk trial period at home. In the pre- and post-test, the speech reception threshold (SRT) with sentences and the percentage correct phoneme scores for CVC words were measured in quiet and background noise at different signal-to-noise ratios. Performance was assessed for two different noise configurations (with a single noise source and with three noise sources) and two different noise materials (stationary speech-weighted noise and multitalker babble). During the 2-wk trial period at home, the CI users evaluated the noise reduction performance in different listening conditions by means of the SSQ questionnaire. In addition to the perceptual evaluation, the noise reduction performance of the beamformer was measured physically as a function of the direction of the noise source. Significant improvements of both the SRT in noise (average improvement of 5-16 dB) and the percentage correct phoneme scores (average improvement of 10-41%) were observed with BEAM compared to the standard hardware directional microphone. In addition, the SSQ questionnaire and subjective evaluation in controlled and real-life scenarios suggested a possible preference for the beamformer in noisy environments. The evaluation demonstrates that the adaptive noise reduction algorithm BEAM in the Nucleus Freedom CI-system may significantly increase the speech perception by cochlear implantees in noisy listening conditions. This is the first monolateral (adaptive) noise reduction strategy actually implemented in a mainstream commercial CI.

  7. The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?

    International Nuclear Information System (INIS)

    Ojeda-G-P, Alejandro; Schneider, Christof W.; Döbeli, Max; Lippert, Thomas; Wokaun, Alexander

    2015-01-01

    Highlights: • The flip-over effect in PLD is observed up to high deposition pressures. • Consistent congruent transfer of the target composition is generally not correct. • The choice of deposition pressure can change the film composition strongly. • Large compositional changes appear at high off-axis angles and large spot sizes. - Abstract: In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion. This effect has been mainly reported for vacuum depositions of single element targets and is particularly noticeable when the aspect ratio of the beam spot is large. We investigate the flip-over effect in vacuum and at three relevant background-gas pressures for pulsed laser deposition using a La 0.4 Ca 0.6 MnO 3 target by measuring the thickness dependence of the deposited material as a function of angle. The film thicknesses and compositions are determined by Rutherford backscattering and argon is used to reduce the influence of additional chemical reactions in the plasma. The results show the prevalence of the flip-over effect for all pressures except for the highest, i.e. 1 × 10 −1 mbar, where the film thickness is constant for all angles. The composition profiles show noticeable compositional variations of up to 30% with respect to the target material depending on the background gas pressure, the angular location, and the laser spot dimensions.

  8. The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda-G-P, Alejandro [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); Schneider, Christof W., E-mail: christof.schneider@psi.ch [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); Döbeli, Max [Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland); Lippert, Thomas; Wokaun, Alexander [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland)

    2015-12-01

    Highlights: • The flip-over effect in PLD is observed up to high deposition pressures. • Consistent congruent transfer of the target composition is generally not correct. • The choice of deposition pressure can change the film composition strongly. • Large compositional changes appear at high off-axis angles and large spot sizes. - Abstract: In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion. This effect has been mainly reported for vacuum depositions of single element targets and is particularly noticeable when the aspect ratio of the beam spot is large. We investigate the flip-over effect in vacuum and at three relevant background-gas pressures for pulsed laser deposition using a La{sub 0.4}Ca{sub 0.6}MnO{sub 3} target by measuring the thickness dependence of the deposited material as a function of angle. The film thicknesses and compositions are determined by Rutherford backscattering and argon is used to reduce the influence of additional chemical reactions in the plasma. The results show the prevalence of the flip-over effect for all pressures except for the highest, i.e. 1 × 10{sup −1} mbar, where the film thickness is constant for all angles. The composition profiles show noticeable compositional variations of up to 30% with respect to the target material depending on the background gas pressure, the angular location, and the laser spot dimensions.

  9. Unit mechanisms of fission gas release: Current understanding and future needs

    Science.gov (United States)

    Tonks, Michael; Andersson, David; Devanathan, Ram; Dubourg, Roland; El-Azab, Anter; Freyss, Michel; Iglesias, Fernando; Kulacsy, Katalin; Pastore, Giovanni; Phillpot, Simon R.; Welland, Michael

    2018-06-01

    Gaseous fission product transport and release has a large impact on fuel performance, degrading fuel and gap properties. While gaseous fission product behavior has been investigated with bulk reactor experiments and simplified analytical models, recent improvements in experimental and modeling approaches at the atomistic and mesoscales are beginning to reveal new understanding of the unit mechanisms that define fission product behavior. Here, existing research on the basic mechanisms of fission gas release during normal reactor operation are summarized and critical areas where work is needed are identified. This basic understanding of the fission gas behavior mechanisms has the potential to revolutionize our ability to predict fission product behavior and to design fuels with improved performance. In addition, this work can serve as a model on how a coupled experimental and modeling approach can be applied to understand the unit mechanisms behind other critical behaviors in reactor materials.

  10. Understanding gas production mechanism and effectiveness of well stimulation in the Haynesville shale through reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Fan, L.; Thompson, J.W.; Robinson, J.R. [Schlumberger, Houston, TX (United States)

    2010-07-01

    The Haynesville Shale Basin is one of the large and most active shale gas plays in the United States, with 185 horizontal rigs currently in place. The Haynesville Shale is a very tight source rock and resource play. The gas resources are being converted into gas reserves with horizontal wells and hydraulic fracture treatments. A complex fracture network created during well stimulation is the main factor in generating superior early well performance in the area. The key to making better wells in all the gas shale plays is to understand how to create more surface area during hydraulic stimulation jobs and preserve the surface area for as long as possible. This paper presented a unique workflow and methodology that has enabled analysis of production data using reservoir simulation to explain the shale gas production mechanism and the effectiveness of stimulation treatments along laterals. Since 2008, this methodology has been used to analyze production data from more than 30 horizontal wells in the Haynesville Shale. Factors and parameters relating to short and long term well performance were investigated, including pore pressure, rock matrix quality, natural fractures, hydraulic fractures, and complex fracture networks. Operators can use the simulation results to determine where and how to spend resources to produce better wells and to reduce the uncertainties of developing these properties. 19 refs., 1 tab., 17 figs.

  11. Unit mechanisms of fission gas release: Current understanding and future needs

    Energy Technology Data Exchange (ETDEWEB)

    Tonks, Michael; Andersson, David; Devanathan, Ram; Dubourg, Roland; El-Azab, Anter; Freyss, Michel; Iglesias, Fernando; Kulacsy, Katalin; Pastore, Giovanni; Phillpot, Simon R.; Welland, Michael

    2018-06-01

    Gaseous fission product transport and release has a large impact on fuel performance, degrading fuel properties and, once the gas is released into the gap between the fuel and cladding, lowering gap thermal conductivity and increasing gap pressure. While gaseous fission product behavior has been investigated with bulk reactor experiments and simplified analytical models, recent improvements in experimental and modeling approaches at the atomistic and mesoscales are being applied to provide unprecedented understanding of the unit mechanisms that define the fission product behavior. In this article, existing research on the basic mechanisms behind the various stages of fission gas release during normal reactor operation are summarized and critical areas where experimental and simulation work is needed are identified. This basic understanding of the fission gas behavior mechanisms has the potential to revolutionize our ability to predict fission product behavior during reactor operation and to design fuels that have improved fission product retention. In addition, this work can serve as a model on how a coupled experimental and modeling approach can be applied to understand the unit mechanisms behind other critical behaviors in reactor materials.

  12. GEM gas detectors for soft X-ray imaging in fusion devices with neutron–gamma background

    Energy Technology Data Exchange (ETDEWEB)

    Pacella, Danilo, E-mail: danilo.pacella@enea.it [Associazione EURATOM-ENEA, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Romano, Afra; Gabellieri, Lori [Associazione EURATOM-ENEA, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Murtas, Fabrizio [Istituto Nazionale di Fisica Nucleare, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Mazon, Didier [Association EURATOM-CEA, CEA Cadarache, DSM/IRFM, 13108 St. Paul Lez Durance Cedex (France)

    2013-08-21

    A triple gas electron multiplier (GEM) detector has been built and characterized in a collaboration between ENEA, INFN and CEA to develop a soft X-ray imaging diagnostic for magnetic fusion plasmas. It has an active area of 5×5 cm{sup 2}, 128 pixels and electronics in counting mode. Since burning plasma experiments will have a very large background of radiation, this prototype has been tested with contemporary X-ray, neutron and gamma irradiation, to study the detection efficiencies, and the discrimination capabilities. The detector has been preliminarily characterized under DD neutron irradiation (2.45 MeV) up to 2.2×10{sup 6} n/s on the detector active area, showing a detection efficiency of about 10{sup −4}, while the detection efficiency of X-rays is more than three orders of magnitude higher. The detector has been also tested under DT neutron flux (14 MeV) up to 2.8×10{sup 8} n/s on the whole detector, with a detection efficiency of about 10{sup −5}. The calibration of the γ-rays detection has been done by means of a source of {sup 60}Co (gamma rays of energy 1.17 MeV and 1.33 MeV) and the detection efficiency was found of the order of 10{sup −4}. Thanks to the adjustable gain of the detector and the discrimination threshold of the electronics, it is possible to minimize the sensitivity to neutrons and gamma, and discriminate the X-ray signals even with very high radiative background.

  13. Diving Deep: A Comparative Study of Educator Undergraduate and Graduate Backgrounds and Their Effect on Student Understanding of Engineering and Engineering Careers, Utilizing an Underwater Robotics Program

    Science.gov (United States)

    Scribner, J. Adam

    Numerous studies have demonstrated that educators having degrees in their subjects significantly enhances student achievement, particularly in secondary mathematics and science (Chaney, 1995; Goe, 2007; Rowan, Chiang, & Miller, 1997; Wenglinsky, 2000). Yet, science teachers in states that adopt the Next Generation Science Standards will be facilitating classroom engineering activities despite the fact that few have backgrounds in engineering. This quantitative study analyzed ex-post facto WaterBotics (an innovative underwater robotics curriculum for middle and high school students) data to determine if educators having backgrounds in engineering (i.e., undergraduate and graduate degrees in engineering) positively affected student learning on two engineering outcomes: 1) the engineering design process, and 2) understanding of careers in engineering (who engineers are and what engineers do). The results indicated that educators having backgrounds in engineering did not significantly affect student understanding of the engineering design process or careers in engineering when compared to educators having backgrounds in science, mathematics, technology education, or other disciplines. There were, however, statistically significant differences between the groups of educators. Students of educators with backgrounds in technology education had the highest mean score on assessments pertaining to the engineering design process while students of educators with disciplines outside of STEM had the highest mean scores on instruments that assess for student understanding of careers in engineering. This might be due to the fact that educators who lack degrees in engineering but who teach engineering do a better job of "sticking to the script" of engineering curricula.

  14. Fracture mapping in clays, using gas geochemistry: background, design of a mobile laboratory, and surveys in England and Italy

    International Nuclear Information System (INIS)

    Gregory, R.G.; Duddridge, G.A.

    1991-01-01

    Integrated soil gas analyses for helium, radon, carbon dioxide and oxygen allow the accurate interpretation of soil gas signatures as indicators of underlying structure, due to large variations over faults and fractures. Structures such as these provide channelways for fluid movement in the upper crust. A mobile gas geochemistry laboratory for the analysis of soil gases was constructed and surveys were carried out at sites in England and Italy. At the Down Ampney site, Gloucestershire, gas was injected into a fault plane, and recorded some hours later at the surface. Refinement of this experiment would allow a full characterization of permeable pathways at a site to be made. The soil gas technique has been shown to be viable as an independent site investigation method for the study of fracturing and groundwater movement around potential waste repository sites

  15. Fracture mapping in clays: using gas geochemistry. Background, design of a mobile laboratory and surveys in England and Italy

    International Nuclear Information System (INIS)

    Duddridge, G.A.

    1991-06-01

    Integrated soil gas analyses for helium, radon, carbon dioxide and oxygen allow the accurate interpretation of soil gas signatures as indicators of underlying structure, due to large variations over faults and fractures. Structures such as these provide channelways for fluid movement in the upper crust. A mobile gas geochemistry laboratory for the analysis of soil gases was constructed and surveys were carried out at sites in England and Italy. At the Down Ampney site, Gloucestershire, gas was injected into a fault plane, and recorded some hours later at the surface. Refinement of this experiment would allow a full characterisation of permeable pathways at a site to be made. The soil gas technique has been shown to be viable as an independent site investigation method for the study of fracturing and groundwater movement around potential waste repository sites. (author)

  16. Experimental and computational study of the effect of 1 atm background gas on nanoparticle generation in femtosecond laser ablation of metals

    Science.gov (United States)

    Wu, Han; Wu, Chengping; Zhang, Nan; Zhu, Xiaonong; Ma, Xiuquan; Zhigilei, Leonid V.

    2018-03-01

    Laser ablation of metal targets is actively used for generation of chemically clean nanoparticles for a broad range of practical applications. The processes involved in the nanoparticle formation at all relevant spatial and temporal scales are still not fully understood, making the precise control of the size and shape of the nanoparticles challenging. In this paper, a combination of molecular dynamics simulations and experiments is applied to investigate femtosecond laser ablation of aluminum targets in vacuum and in 1 atm argon background gas. The results of the simulations reveal a strong effect of the background gas environment on the initial plume expansion and evolution of the nanoparticle size distribution. The suppression of the generation of small/medium-size Al clusters and formation of a dense layer at the front of the expanding ablation plume, observed during the first nanosecond of the plume expansion in a simulation performed in the gas environment, have important implications on the characteristics of the nanoparticles deposited on a substrate and characterized in the experiments. The nanoparticles deposited in the gas environment are found to be more round-shaped and less flattened as compared to those deposited in vacuum. The nanoparticle size distributions exhibit power-law dependences with similar values of exponents obtained from fitting experimental and simulated data. Taken together, the results of this study suggest that the gas environment may be effectively used to control size and shape of nanoparticles generated by laser ablation.

  17. Perspectives on understanding and verifying the safety terrain of modular high temperature gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Donald E., E-mail: donald@carlsonperin.net [11221 Empire Lane, Rockville, MD 20852 (United States); Ball, Sydney J., E-mail: beckysyd@comcast.net [100 Greywood Place, Oak Ridge, TN 37830 (United States)

    2016-09-15

    The passive safety characteristics of modular high temperature gas-cooled reactors (HTGRs) are conceptually well known and are largely supported by insights from past and ongoing research. This paper offers perspectives on selected issues in areas where further analysis and testing achievable within existing research and demonstration programs could help address residual uncertainties and better support the analysis of safety performance and the regulatory assessment of defense in depth. Areas considered include the evaluation of normal and anomalous core operating conditions and the analysis of accidents involving loss of forced cooling, coolant depressurization, air ingress, moisture ingress, and reactivity events. In addition to discussing associated uncertainties and potential measures to address them, this paper also proposes supplemental “safety terrain” studies that would use realistic assessments of postulated extreme event sequences to establish a more comprehensive understanding of the inherent behaviors and ultimate safety capabilities of modular HTGRs.

  18. Perspectives on Understanding and Verifying the Safety Terrain of Modular High Temperature Gas-Cooled Reactors

    International Nuclear Information System (INIS)

    Carlson, Donald E.

    2014-01-01

    The inherent safety characteristics of modular high temperature gas-cooled reactors (HTGRs) are conceptually well known and are largely supported by insights from past and ongoing research. This paper offers perspectives on selected issues in areas where further analysis and testing achievable within existing research and demonstration programs could help address residual uncertainties and better support the analysis of safety performance and the regulatory assessment of defense in depth. Areas considered include the evaluation of normal and anomalous core operating conditions and the analysis of accidents involving coolant depressurization, air ingress, moisture ingress, and reactivity insertion. In addition to discussing associated uncertainties and potential measures to address them, the paper also proposes supplemental “safety terrain” studies that would use realistic assessments of postulated extreme event sequences to establish a more comprehensive understanding of the inherent behaviors and ultimate safety capabilities of modular HTGRs. (author)

  19. Dynamics of gas-surface interactions atomic-level understanding of scattering processes at surfaces

    CERN Document Server

    Díez Muniño, Ricardo

    2013-01-01

    This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the ‘surface science’ approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level u...

  20. From comic relief to real understanding; how intestinal gas causes symptoms.

    LENUS (Irish Health Repository)

    Quigley, E M M

    2012-02-03

    Gas content and transit appear to conspire with the motor and sensory responses of the gut to produce gas related symptoms, both in normal individuals and especially in patients with irritable bowel syndrome (IBS). In relation to gas in IBS, two questions need to be addressed: do IBS patients produce more gas and what are the relationships between intestinal gas and symptoms? The balance of evidence seems to indicate that distension is a real phenomenon in IBS and that such distension accurately reflects gas content. More problematic is extrapolation of the observations relating symptoms to gas transit and retention.

  1. Investigation of Radio Frequency Discharges and Langmuir Probe Diagnostic Methods in a Fast Flowing Electronegative Background Gas

    Science.gov (United States)

    2007-12-01

    quantitatively explore: the generation of the plasma and 4 excited neutral species, the effects of the neutral gas flow on the discharge sheath...neutral species. The larg electric fields in the sheath and bulk plasma increase the ionization rate and the positiv ion density in the discharge

  2. Glutamate decarboxylase and. gamma. -aminobutyric acid transaminase activity in brain structures during action of high concentrated sulfide gas on a background of hypo- and hypercalcemia

    Energy Technology Data Exchange (ETDEWEB)

    Kadyrov, G.K.; Aliyev, A.M.

    Activity of the following enzymes was studied on the background of hypo- and hypercalcemia and exposure to high concentration of sulfide gas: glutamate decarboxylase (GDC) and {gamma}-aminobutyric acid transaminase (GABA-T). These enzymes regulate metabolism of GABA. The results showed that a 3.5 hr exposure to sulfide gas at a concentration of 0.3 mg/1 led to significantly increased activity of GDC in cerebral hemispheres, cerebellum and in brain stem. Activity of GABA-T dropped correspondingly. On the background of hypercalcemia induced by im. injection of 10% calcium gluconate (0.6 m1/200 g body weight of experimental rats) the negative effect caused by the exposure to sulfide gas was diminished. Under conditions of hypocalcemia (im. injection of 10 mg/200 g body weight of sodium oxalate), exposure to sulfide gas led to a significantly decreased activity of GDC and GABA-T in the hemispheres and in the brain stem, but in the cerebellum the activity of GDC increased sharply while that of GABA-T decreased correspondingly. 8 refs.

  3. Understanding acoustic physics in oil and gas wellbores with the presence of ubiquitous geometric eccentricity

    Science.gov (United States)

    Liu, Yang; D'Angelo, Ralph M.; Choi, Gloria; Zhu, Lingchen; Bose, Sandip; Zeroug, Smaine

    2018-04-01

    Once an oil and gas wellbore has been drilled, steel casings and cement slurry are placed to ensure structural support, protection from fluid invasion, and most importantly to provide zonal isolation. The actual wellbore and string structure is rarely concentric but rather is often an eccentric one, especially in deviated boreholes. The term "eccentricity" is used to describe how off-center a casing string is within another pipe or the open-hole. In a typical double-string configuration, the inner casing is eccentered with respect to the outer string which itself is also eccentered within the cylindrical hole. The annuli may or may not be filled with solid cement, and the cement may have liquid-filled channels or be disbonded over localized azimuthal ranges. The complexity of wave propagation along axial intervals is significant in that multiple modes can be excited and detected with characteristics that are affected by the various parameters, including eccentering, in a non-linear fashion. A successful diagnosis of cement flaws largely relies on a thorough understanding of the complex acoustic modal information. The present study employs both modeling and experiments to fully understand the acoustic wave propagation in the complex, fluid-solid nested, cylindrically layered structures, with geometric eccentricities. The experimental results show excellent agreement with the theoretical predictions from newly developed, borehole acoustic modeling approaches. As such, it provides the basis for better understanding the operative wave physics and providing the means for effective inspection methodologies to assess well integrity and zonal isolation of oil wells.

  4. Improving Students' Understanding of the Connections between the Concepts of Real-Gas Mixtures, Gas Ideal-Solutions, and Perfect-Gas Mixtures

    Science.gov (United States)

    Privat, Romain; Jaubert, Jean-Noël; Moine, Edouard

    2016-01-01

    In many textbooks of chemical-engineering thermodynamics, a gas mixture obeying the fundamental law pV[subscript m] = RT is most often called ideal-gas mixture (in some rare cases, the term perfect-gas mixture can be found). These textbooks also define the fundamental concept of ideal solution which in theory, can be applied indifferently to…

  5. Impact of the vertical emission profiles on background gas-phase pollution simulated from the EMEP emissions over Europe

    Directory of Open Access Journals (Sweden)

    S. Mailler

    2013-06-01

    Full Text Available Five one-year air quality simulations over a domain covering Europe have been performed using the CHIMERE chemistry transport model and the EMEP emission dataset for Europe. These five simulations differ only by the representation of the effective emission heights for anthropogenic emissions: one has been run using the EMEP standard recommendations, three others with vertical injection profiles derived from the EMEP recommendations but multiplying the injection height by 0.75, 0.50 and 0.25, respectively, while the last one uses vertical profiles derived from the recent literature. It is shown that using injection heights lower than the EMEP recommendations leads to significantly improved simulation of background SO2, NO2 and O3 concentrations when compared to the Airbase station measurements.

  6. Mid infrared quantum cascade laser operating in pure amplitude modulation for background-free trace gas spectroscopy.

    Science.gov (United States)

    Bidaux, Yves; Bismuto, Alfredo; Patimisco, Pietro; Sampaolo, Angelo; Gresch, Tobias; Strubi, Gregory; Blaser, Stéphane; Tittel, Frank K; Spagnolo, Vincenzo; Muller, Antoine; Faist, Jérôme

    2016-11-14

    We present a single mode multi-section quantum cascade laser source composed of three different sections: master oscillator, gain and phase section. Non-uniform pumping of the QCL's gain reveals that the various laser sections are strongly coupled. Simulations of the electronic and optical properties of the laser (based on the density matrix and scattering matrix formalisms, respectively) were performed and a good agreement with measurements is obtained. In particular, a pure modulation of the laser output power can be achieved. This capability of the device is applied in tunable-laser spectroscopy of N2O where background-free quartz enhanced photo acoustic spectral scans with nearly perfect Voigt line shapes for the selected absorption line are obtained.

  7. Application of meta-omics techniques to understand greenhouse gas emissions originating from ruminal metabolism.

    Science.gov (United States)

    Wallace, Robert J; Snelling, Timothy J; McCartney, Christine A; Tapio, Ilma; Strozzi, Francesco

    2017-01-16

    Methane emissions from ruminal fermentation contribute significantly to total anthropological greenhouse gas (GHG) emissions. New meta-omics technologies are beginning to revolutionise our understanding of the rumen microbial community structure, metabolic potential and metabolic activity. Here we explore these developments in relation to GHG emissions. Microbial rumen community analyses based on small subunit ribosomal RNA sequence analysis are not yet predictive of methane emissions from individual animals or treatments. Few metagenomics studies have been directly related to GHG emissions. In these studies, the main genes that differed in abundance between high and low methane emitters included archaeal genes involved in methanogenesis, with others that were not apparently related to methane metabolism. Unlike the taxonomic analysis up to now, the gene sets from metagenomes may have predictive value. Furthermore, metagenomic analysis predicts metabolic function better than only a taxonomic description, because different taxa share genes with the same function. Metatranscriptomics, the study of mRNA transcript abundance, should help to understand the dynamic of microbial activity rather than the gene abundance; to date, only one study has related the expression levels of methanogenic genes to methane emissions, where gene abundance failed to do so. Metaproteomics describes the proteins present in the ecosystem, and is therefore arguably a better indication of microbial metabolism. Both two-dimensional polyacrylamide gel electrophoresis and shotgun peptide sequencing methods have been used for ruminal analysis. In our unpublished studies, both methods showed an abundance of archaeal methanogenic enzymes, but neither was able to discriminate high and low emitters. Metabolomics can take several forms that appear to have predictive value for methane emissions; ruminal metabolites, milk fatty acid profiles, faecal long-chain alcohols and urinary metabolites have all

  8. Understanding and managing environmental liability in the Saskatchewan oil and gas industry

    International Nuclear Information System (INIS)

    Andrychuk, L.D.; LeBlanc, L.B.

    1998-01-01

    An overview of Saskatchewan legislative framework regarding the oil and gas industry was presented. In the oil and gas industry, environmental issues are regulated at the provincial level, but the industry must also be aware of federal environmental law when dealing with federal lands, federal financial assistance, interprovincial or international projects or projects which have transboundary environmental effects. In this context, the provisions of the Oil and Gas Conservation Act (OGCA) and the Oil and Gas Conservation Regulations (OGCR), the licensing of oil and gas wells, the acquisition and surrender of surface rights, and the procedures involved in environmental assessment approval were outlined. Emission control, air pollution abatement, the storage and disposal of hazardous materials, environmental issues in property transactions, and corporate environmental management are also subject to regulation under OGCA and OGCR. 42 refs

  9. Understanding internal backgrounds in NaI(Tl) crystals toward a 200 kg array for the KIMS-NaI experiment

    Energy Technology Data Exchange (ETDEWEB)

    Adhikari, P.; Adhikari, G.; Oh, S.Y. [Sejong University, Department of Physics, Seoul (Korea, Republic of); Choi, S.; Joo, H.W.; Kim, K.W.; Kim, S.K. [Seoul National University, Department of Physics and Astronomy, Seoul (Korea, Republic of); Ha, C.; Jeon, E.J.; Kang, W.G.; Kim, H.O.; Kim, N.Y.; Lee, H.S.; Lee, J.H.; Lee, M.H.; Leonard, D.S.; Li, J.; Olsen, S.L.; Park, H.K.; Park, K.S.; So, J.H.; Yoon, Y.S. [Institute for Basic Science, Center for Underground Physics, Daejeon (Korea, Republic of); Hahn, I.S. [Ewha Womans University, Department of Science Education, Seoul (Korea, Republic of); Kim, H.J. [Kyungpook National University, Department of Physics, Daegu (Korea, Republic of); Kim, Y.D. [Sejong University, Department of Physics, Seoul (Korea, Republic of); Institute for Basic Science, Center for Underground Physics, Daejeon (Korea, Republic of); Kim, Y.H. [Institute for Basic Science, Center for Underground Physics, Daejeon (Korea, Republic of); Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Park, H.S. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2016-04-15

    The Korea Invisible Mass Search (KIMS) collaboration has developed low-background NaI(Tl) crystals that are suitable for the direct detection of WIMP dark matter. Building on experience accumulated during the KIMS-CsI programs, the KIMS-NaI experiment will consist of a 200 kg NaI(Tl) crystal array surrounded by layers of shielding structures and will be operated at the Yangyang underground laboratory. The goal is to provide an unambiguous test of the DAMA/LIBRA annual modulation signature. Measurements of six prototype crystals show progress in the reduction of internal contamination from radioisotopes. Based on our understanding of these measurements, we expect to achieve a background level in the final detector configuration that is less than 1 count/day/keV/kg for recoil energies around 2 keV. The annual modulation sensitivity for the KIMS-NaI experiment shows that an unambiguous 7σ test of the DAMA/LIBRA signature would be possible with a 600 kg year exposure with this system. (orig.)

  10. Towards understanding the influence of electron-gas interactions on imaging in an environmental TEM

    DEFF Research Database (Denmark)

    Wagner, Jakob Birkedal; Boothroyd, Chris; Beleggia, Marco

    2011-01-01

    be used. In the differential pumping approach, the gas is confined to the region around the specimen only by pressure-limiting apertures. In order to retain flexibility in the sample region, the pole piece gap and the highest pressure part of the column are relatively large (~7mm). As a result, electron...... on-going work involves the systematic measurements of images, diffraction patterns and energy-loss spectra acquired in the presence of gas, for a variety of different beam current densities, accelerating voltages and choices of specimen....

  11. Background sources at PEP

    International Nuclear Information System (INIS)

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, γ-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs

  12. Cross-correlation of the cosmic microwave background with the 2MASS galaxy survey: Signatures of dark energy, hot gas, and point sources

    International Nuclear Information System (INIS)

    Afshordi, Niayesh; Loh, Yeong-Shang; Strauss, Michael A.

    2004-01-01

    We cross-correlate the cosmic microwave background temperature anisotropies observed by the Wilkinson Microwave Anisotropy Probe (WMAP) with the projected distribution of extended sources in the Two Micron All Sky Survey (2MASS). By modeling the theoretical expectation for this signal, we extract the signatures of dark energy [integrated Sachs-Wolfe effect (ISW)], hot gas [thermal Sunyaev-Zeldovich (SZ) effect], and microwave point sources in the cross-correlation. Our strongest signal is the thermal SZ, at the 3.1-3.7σ level, which is consistent with the theoretical prediction based on observations of x-ray clusters. We also see the ISW signal at the 2.5σ level, which is consistent with the expected value for the concordance ΛCDM cosmology, and is an independent signature of the presence of dark energy in the Universe. Finally, we see the signature of microwave point sources at the 2.7σ level

  13. Nitro-polycyclic aromatic hydrocarbons - gas-particle partitioning, mass size distribution, and formation along transport in marine and continental background air

    Science.gov (United States)

    Lammel, Gerhard; Mulder, Marie D.; Shahpoury, Pourya; Kukučka, Petr; Lišková, Hana; Přibylová, Petra; Prokeš, Roman; Wotawa, Gerhard

    2017-05-01

    Nitro-polycyclic aromatic hydrocarbons (NPAH) are ubiquitous in polluted air but little is known about their abundance in background air. NPAHs were studied at one marine and one continental background site, i.e. a coastal site in the southern Aegean Sea (summer 2012) and a site in the central Great Hungarian Plain (summer 2013), together with the parent compounds, PAHs. A Lagrangian particle dispersion model was used to track air mass history. Based on Lagrangian particle statistics, the urban influence on samples was quantified for the first time as a fractional dose to which the collected volume of air had been exposed. At the remote marine site, the 3-4-ring NPAH (sum of 11 targeted species) concentration was 23.7 pg m-3 while the concentration of 4-ring PAHs (6 species) was 426 pg m-3. The most abundant NPAHs were 2-nitrofluoranthene (2NFLT) and 3-nitrophenanthrene. Urban fractional doses in the range of air are the lowest ever reported and remarkably lower, by more than 1 order of magnitude, than 1 decade before. Day-night variation of NPAHs at the continental site reflected shorter lifetime during the day, possibly because of photolysis of some NPAHs. The yields of formation of 2NFLT and 2-nitropyrene (2NPYR) in marine air seem to be close to the yields for OH-initiated photochemistry observed in laboratory experiments under high NOx conditions. Good agreement is found for the prediction of NPAH gas-particle partitioning using a multi-phase poly-parameter linear free-energy relationship. Sorption to soot is found to be less significant for gas-particle partitioning of NPAHs than for PAHs. The NPAH levels determined in the south-eastern outflow of Europe confirm intercontinental transport potential.

  14. Understanding the psychological impact of unconventional gas developments in affected communities

    International Nuclear Information System (INIS)

    Lai, Po-Hsin; Lyons, Kevin D.; Gudergan, Siegfried P.; Grimstad, Sidsel

    2017-01-01

    The rapid growth of unconventional gas developments has created widespread community concerns in many parts of the world. This study adds to the literature on the psychological impact of related developments by drawing upon Conservation of Resources (COR) theory and the concept of place attachment. In providing a holistic framework, it examines community residents’ appraisals of and emotional responses to impacts of an unconventional gas development, and establishes heterogeneity in these appraisals and responses among residents. The findings show that perceived negative impact on resources that encompass personal and communal resources due to the development contributes to negative emotions that can lead to deteriorated psychological well-being. Conversely, perceived positive impact on resources is conducive to positive emotions that in turn can foster residents’ psychological well-being. The findings further reveal that perceived impact on place attachment partially mediates the relationship between perceived impact on resources and negative emotions. Importantly, these effects differ in strength for residents characterized by different ages, lengths of residence, and distances of their properties from the development. Implications for how this framework can be applied to minimize unwanted impacts and be incorporated into social license that goes beyond the current model of community consultation are discussed. - Highlights: • The psychological impact of a gas project in a rural community is examined. • A sense of perceived loss to personal and communal resources is revealed. • Loss to resources leads to negative emotions mediated by loss to place attachment. • Heterogeneity in perceived impacts and emotional responses is evident.

  15. Understanding and managing leakage in forest-based greenhouse-gas-mitigation projects.

    Science.gov (United States)

    Schwarze, Reimund; Niles, John O; Olander, Jacob

    2002-08-15

    A major concern about land use, land-use change and forestry (LULUCF) projects under the Clean Development Mechanism (CDM) is the potential for leakage. Leakage refers to a net increase of greenhouse-gas emissions in an area outside the project resulting from the CDM activity. This paper provides an overview of leakage, its definitions and its causes. It describes ways that LULUCF projects may suffer from leakage and attempts to assess the magnitude of leakage risks for different LULUCF project types. It also summarizes some of the approaches, both in terms of policies and project development, to address LULUCF leakage.

  16. Understanding the Design and Performance of Emissions Trading Systems for Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Toman, M.

    1999-01-31

    Research Spotlight presents new research findings and projects underway at Resources for the Future that are relevant to the analysis of climate change policy. As interest in greenhouse gas trading policies grows in the United States and other Annex I countries, so does the need for stronger analytical tools. The paper by Tietenberg in this collection lays out some of the principal conceptual issues that analysts face in providing more accurate and relevant tools and results for decisionmakers. In this paper we build on Tietenberg's analysis to consider some of the key modeling challenges that analysts face in developing an improved capacity for quantitatively assessing real-world policies.

  17. Understanding the life cycle surface land requirements of natural gas-fired electricity

    Science.gov (United States)

    Jordaan, Sarah M.; Heath, Garvin A.; Macknick, Jordan; Bush, Brian W.; Mohammadi, Ehsan; Ben-Horin, Dan; Urrea, Victoria; Marceau, Danielle

    2017-10-01

    The surface land use of fossil fuel acquisition and utilization has not been well characterized, inhibiting consistent comparisons of different electricity generation technologies. Here we present a method for robust estimation of the life cycle land use of electricity generated from natural gas through a case study that includes inventories of infrastructure, satellite imagery and well-level production. Approximately 500 sites in the Barnett Shale of Texas were sampled across five life cycle stages (production, gathering, processing, transmission and power generation). Total land use (0.62 m2 MWh-1, 95% confidence intervals ±0.01 m2 MWh-1) was dominated by midstream infrastructure, particularly pipelines (74%). Our results were sensitive to power plant heat rate (85-190% of the base case), facility lifetime (89-169%), number of wells per site (16-100%), well lifetime (92-154%) and pipeline right of way (58-142%). When replicated for other gas-producing regions and different fuels, our approach offers a route to enable empirically grounded comparisons of the land footprint of energy choices.

  18. Veterinary decision making in relation to metritis - a qualitative approach to understand the background for variation and bias in veterinary medical records

    Directory of Open Access Journals (Sweden)

    Enevoldsen Carsten

    2009-08-01

    Full Text Available Abstract Background Results of analyses based on veterinary records of animal disease may be prone to variation and bias, because data collection for these registers relies on different observers in different settings as well as different treatment criteria. Understanding the human influence on data collection and the decisions related to this process may help veterinary and agricultural scientists motivate observers (veterinarians and farmers to work more systematically, which may improve data quality. This study investigates qualitative relations between two types of records: 1 'diagnostic data' as recordings of metritis scores and 2 'intervention data' as recordings of medical treatment for metritis and the potential influence on quality of the data. Methods The study is based on observations in veterinary dairy practice combined with semi-structured research interviews of veterinarians working within a herd health concept where metritis diagnosis was described in detail. The observations and interviews were analysed by qualitative research methods to describe differences in the veterinarians' perceptions of metritis diagnosis (scores and their own decisions related to diagnosis, treatment, and recording. Results The analysis demonstrates how data quality can be affected during the diagnostic procedures, as interaction occurs between diagnostics and decisions about medical treatments. Important findings were when scores lacked consistency within and between observers (variation and when scores were adjusted to the treatment decision already made by the veterinarian (bias. The study further demonstrates that veterinarians made their decisions at 3 different levels of focus (cow, farm, population. Data quality was influenced by the veterinarians' perceptions of collection procedures, decision making and their different motivations to collect data systematically. Conclusion Both variation and bias were introduced into the data because of

  19. Influence of an O2 background gas on the composition and kinetic energies of species in laser induced La0.4Ca0.6MnO3 plasmas

    Science.gov (United States)

    Chen, Jikun; Stender, Dieter; Bator, Matthias; Schneider, Christof W.; Lippert, Thomas; Wokaun, Alexander

    2013-08-01

    Oxygen is one of the most commonly used background gases for pulsed laser deposition of oxide thin films. In this work the properties of a 308 nm laser-induced La0.4Ca0.6MnO3 plasma were analyzed using a quadrupole mass spectrometer combined with an energy analyzer, to investigate the interaction between the various plasma species and the background gas. The composition and kinetic energies of the plasma species were compared in vacuum and an O2 background gas at different pressures. It has been observed that the O2 background gas decreases the kinetic energy of the positively charged atomic plasma species. In addition, the interaction with the O2 background gas causes the generation of positive diatomic oxide species of LaO+, CaO+ and MnO+. The amount of negatively charged diatomic or tri-atomic oxide species decreases in the O2 background compared to vacuum, while the amount of O2- increases strongly.

  20. Influence of an O{sub 2} background gas on the composition and kinetic energies of species in laser induced La{sub 0.4}Ca{sub 0.6}MnO{sub 3} plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Stender, Dieter; Bator, Matthias; Schneider, Christof W. [Paul Scherrer Institute, General Energy Research Department, CH-5232 Villigen PSI (Switzerland); Lippert, Thomas, E-mail: Thomas.lippert@psi.ch [Paul Scherrer Institute, General Energy Research Department, CH-5232 Villigen PSI (Switzerland); Wokaun, Alexander [Paul Scherrer Institute, General Energy Research Department, CH-5232 Villigen PSI (Switzerland)

    2013-08-01

    Oxygen is one of the most commonly used background gases for pulsed laser deposition of oxide thin films. In this work the properties of a 308 nm laser-induced La{sub 0.4}Ca{sub 0.6}MnO{sub 3} plasma were analyzed using a quadrupole mass spectrometer combined with an energy analyzer, to investigate the interaction between the various plasma species and the background gas. The composition and kinetic energies of the plasma species were compared in vacuum and an O{sub 2} background gas at different pressures. It has been observed that the O{sub 2} background gas decreases the kinetic energy of the positively charged atomic plasma species. In addition, the interaction with the O{sub 2} background gas causes the generation of positive diatomic oxide species of LaO{sup +}, CaO{sup +} and MnO{sup +}. The amount of negatively charged diatomic or tri-atomic oxide species decreases in the O{sub 2} background compared to vacuum, while the amount of O{sub 2}{sup −} increases strongly.

  1. Calibration of a low background gas-flow proportional counter to estimate "2"3"4Th activity in coastal waters

    International Nuclear Information System (INIS)

    Cuesta, E.; Lozano, R.L.; Miguel, E.G. San; Casas-Ruiz, M.; Bolívar, J.P.

    2016-01-01

    This paper relates the calibration of a low background gas-flow proportional counter. This calibration has been used to determine low activity of "2"3"4Th in coastal water samples. Two methods were used to prepare calibration samples: Evaporation and Electrodeposition. First method was rejected due to the lack of reproducibility because the different geometry adopted by the drops of tracer once dried on the disk. On the contrary, through the second method, similar efficiencies were obtained in all detectors with an average of 0.401±0.004. In this paper, the whole procedure to obtain "2"3"4Th activity in dissolution as well as in particulate matter has been detailed, and all the algorithms needed to calculate activities and efficiencies are shown. Finally, two experiments have been designed in order to validate the calibration of the beta counter and the method to determine "2"3"4Th in coastal waters with high concentration of particulate matter. - Highlights: • This paper shows a Home-made calibration using two methods to prepare calibration samples. • The algorithms needed to obtain Th-234 activity concentrations are described in full detail. • This is the first time Th-234 has been determined in water samples from Huelva Estuary.

  2. Cosmic Microwave Background as a Thermal Gas of SU(2 Photons: Implications for the High-z Cosmological Model and the Value of H0

    Directory of Open Access Journals (Sweden)

    Steffen Hahn

    2017-01-01

    Full Text Available Presently, we are facing a 3σ tension in the most basic cosmological parameter, the Hubble constant H0. This tension arises when fitting the Lambda-cold-dark-matter model (ΛCDM to the high-precision temperature-temperature (TT power spectrum of the Cosmic Microwave Background (CMB and to local cosmological observations. We propose a resolution of this problem by postulating that the thermal photon gas of the CMB obeys an SU(2 rather than U(1 gauge principle, suggesting a high-z cosmological model which is void of dark-matter. Observationally, we rely on precise low-frequency intensity measurements in the CMB spectrum and on a recent model independent (low-z extraction of the relation between the comoving sound horizon rs at the end of the baryon drag epoch and H0 (rsH0=const. We point out that the commonly employed condition for baryon-velocity freeze-out is imprecise, judged by a careful inspection of the formal solution to the associated Euler equation. As a consequence, the above-mentioned 3σ tension actually transforms into a 5σ discrepancy. To make contact with successful low-z  ΛCDM cosmology we propose an interpolation based on percolated/depercolated vortices of a Planck-scale axion condensate. For a first consistency test of such an all-z model we compute the angular scale of the sound horizon at photon decoupling.

  3. Geosciences Acting Out: Using Theatre to Understand Citizen Values and Concerns with Respect to Marcellus Gas Development

    Science.gov (United States)

    Orland, B.; Doan, W. J.; Russell, S. B.; Belser, A.

    2014-12-01

    Marcellus shale gas is being developed with unprecedented speed. The highly capitalized energy industry has influenced major changes in the regulatory framework at federal and state levels and entered into mineral lease agreements 100-fold bigger that previously seen in Northern Pennsylvania. At the same time, the technical and scientific issues at play from geology and hydrology through ecology and sociology effectively block local citizens from fully understanding and participating in decision-making about their own futures. The Marcellus Community-Based Performance Program engages adult residents, landowners, and local decision makers in knowledge-generating performances made collectively with those most impacted by shale gas development. Unlike traditional proscenium stage theatre, community-based performance is a collaborative means for exploring a collectively significant issue or circumstance. The choice to use a community-based theatre method, which engages the spectators in the performance itself as a way of making meaning, was based on the following goals to achieve good debate; to engage community participants in discussion through the exchange of ideas, argument and counter-argument, in an effort to further the education of all; to facilitate the perspectives of citizens in communities where different responses to the risk issues exist because of local economies and legacies with resource extraction. The plays and performances, developed around the broad theme of Living with Risk and Uncertainty, use existing research, reports, newspaper articles, and interviews to present the range of perceptions, facts, and issues surrounding the environmental risks associated with natural gas drilling and focused on developing scientific understanding. Performances have been assessed by seeking direct feedback from participants through pre-performance surveys, post-performance dialogues (talk-backs), and exit interviews. Participants have reported the highest levels

  4. Gas

    International Nuclear Information System (INIS)

    1996-01-01

    The French government has decided to modify the conditions of extension of local natural gas authorities to neighbouring districts. The European Union is studying the conditions of internal gas market with the objective of more open markets although considering public service requirements

  5. Understanding the gas sensing properties of polypyrrole coated tin oxide nanofiber mats

    Science.gov (United States)

    Bagchi, Sudeshna; Ghanshyam, C.

    2017-03-01

    Tin oxide-polypyrrole composites have been widely studied for their enhanced sensing performance towards ammonia vapours, but further investigations are required for an understanding of the interaction mechanisms with different target analytes. In this work, polypyrrole coated tin oxide fibers have been synthesized using a two-step approach of electrospinning and vapour phase polymerization for the sensing of ammonia, ethanol, methanol, 2-propanol and acetone vapours. The resistance variation in the presence of these vapours of different nature and concentration is investigated for the determination of sensor response. A decrease in resistance occurred on interaction of tin oxide-polypyrrole with ammonia, as opposed to previous reported works. Partial reduction of polypyrrole due to interfacial interaction with tin oxide has been proposed to explain this behavior. High sensitivity of 7.45 is achieved for 1 ppm ammonia concentration. Furthermore, the sensor exhibited high sensitivity and a faster response towards ethanol vapours although methanol has the highest electron donating capability. The catalytic mechanism has been discussed to explain this interesting behavior. The results reveal that interaction between tin oxide and polypyrrole is crucial to control the predominant sensing mechanism.

  6. Understanding how roadside concentrations of NOx are influenced by the background levels, traffic density, and meteorological conditions using Boosted Regression Trees

    Science.gov (United States)

    Sayegh, Arwa; Tate, James E.; Ropkins, Karl

    2016-02-01

    Oxides of Nitrogen (NOx) is a major component of photochemical smog and its constituents are considered principal traffic-related pollutants affecting human health. This study investigates the influence of background concentrations of NOx, traffic density, and prevailing meteorological conditions on roadside concentrations of NOx at UK urban, open motorway, and motorway tunnel sites using the statistical approach Boosted Regression Trees (BRT). BRT models have been fitted using hourly concentration, traffic, and meteorological data for each site. The models predict, rank, and visualise the relationship between model variables and roadside NOx concentrations. A strong relationship between roadside NOx and monitored local background concentrations is demonstrated. Relationships between roadside NOx and other model variables have been shown to be strongly influenced by the quality and resolution of background concentrations of NOx, i.e. if it were based on monitored data or modelled prediction. The paper proposes a direct method of using site-specific fundamental diagrams for splitting traffic data into four traffic states: free-flow, busy-flow, congested, and severely congested. Using BRT models, the density of traffic (vehicles per kilometre) was observed to have a proportional influence on the concentrations of roadside NOx, with different fitted regression line slopes for the different traffic states. When other influences are conditioned out, the relationship between roadside concentrations and ambient air temperature suggests NOx concentrations reach a minimum at around 22 °C with high concentrations at low ambient air temperatures which could be associated to restricted atmospheric dispersion and/or to changes in road traffic exhaust emission characteristics at low ambient air temperatures. This paper uses BRT models to study how different critical factors, and their relative importance, influence the variation of roadside NOx concentrations. The paper

  7. The Civic Informatics of FracTracker Alliance: Working with Communities to Understand the Unconventional Oil and Gas Industry

    Directory of Open Access Journals (Sweden)

    Kirk Jalbert

    2017-09-01

    Full Text Available Unconventional oil and gas extraction is fueling a wave of resource development often touted as a new era in US energy independence. However, assessing the true costs of extraction is made difficult by the vastness of the industry and lack of regulatory transparency. This paper addresses efforts to fill knowledge gaps taken up by civil society groups, where the resources produced in these efforts are used to make informed critiques of extraction processes and governance. We focus on one civil society organization, called FracTracker Alliance, which works to enhance public understanding by collecting, interpreting, and visualizing oil and gas data in broad partnerships. Drawing on the concepts of civic science, we suggest that the informational practices of civil society research organizations facilitate critical knowledge flows that we term “civic informatics.” We offer three case studies illustrating how different characteristics of civic informatics enable public-minded research as well as build capacity for political mobilizations. Finally, we suggest that empirical studies of civic informatics and its facilitators offer insights for the study of “engaged” Science and Technologies Studies (STS that seek to generate new models of science at the intersection of praxis and theory.

  8. Oil & Natural Gas Technology A new approach to understanding the occurrence and volume of natural gas hydrate in the northern Gulf of Mexico using petroleum industry well logs

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Ann [The Ohio State Univ., Columbus, OH (United States); Majumdar, Urmi [The Ohio State Univ., Columbus, OH (United States)

    2016-03-31

    The northern Gulf of Mexico has been the target for the petroleum industry for exploration of conventional energy resource for decades. We have used the rich existing petroleum industry well logs to find the occurrences of natural gas hydrate in the northern Gulf of Mexico. We have identified 798 wells with well log data within the gas hydrate stability zone. Out of those 798 wells, we have found evidence of gas hydrate in well logs in 124 wells (15% of wells). We have built a dataset of gas hydrate providing information such as location, interval of hydrate occurrence (if any) and the overall quality of probable gas hydrate. Our dataset provides a wide, new perspective on the overall distribution of gas hydrate in the northern Gulf of Mexico and will be the key to future gas hydrate research and prospecting in the area.

  9. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    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....

  10. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface ground water: background, base cases, shallow reservoirs, short-term gas and water transport

    Science.gov (United States)

    Researchers examined gas and water transport between a deep tight shale gas reservoir and a shallow overlying aquifer in the two years following hydraulic fracturing, assuming a pre-existing connecting pathway.

  11. Task 23 - background report on subsurface environmental issues relating to natural gas sweetening and dehydration operations. Topical report, February 1, 1994--February 28, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J.A.

    1998-12-31

    This report describes information pertaining to environmental issues, toxicity, environmental transport, and fate of alkanolamines and glycols associated with natural gas sweetening and dehydration operations. Waste management associated with the operations is also discussed.

  12. Background radiation

    International Nuclear Information System (INIS)

    Arnott, D.

    1985-01-01

    The effects of background radiation, whether natural or caused by man's activities, are discussed. The known biological effects of radiation in causing cancers or genetic mutations are explained. The statement that there is a threshold below which there is no risk is examined critically. (U.K.)

  13. Simulation of PEP-II Accelerator Backgrounds Using TURTLE

    CERN Document Server

    Barlow, Roger J; Kozanecki, Witold; Majewski, Stephanie; Roudeau, Patrick; Stocchi, Achille

    2005-01-01

    We present studies of accelerator-induced backgrounds in the BaBar detector at the SLAC B-Factory, carried out using a modified version ofthe DECAY TURTLE simulation package. Lost-particle backgrounds in PEP-II are dominated by a combination of beam-gas bremstrahlung, beam-gas Coulomb scattering, radiative-Bhabha events and beam-beam blow-up. The radiation damage and detector occupancy caused by the associated electromagnetic shower debris can limit the usable luminosity. In order to understand and mitigate such backgrounds, we have performed a full programme of beam-gas and luminosity-background simulations, that include the effects of the detector solenoidal field, detailed modelling of limiting apertures in both collider rings, and optimization of the betatron collimation scheme in the presence of large transverse tails.

  14. First 5 tower WIMP-search results from the Cryogenic Dark Matter Search with improved understanding of neutron backgrounds and benchmarking

    Energy Technology Data Exchange (ETDEWEB)

    Hennings-Yeomans, Raul [Case Western Reserve Univ., Cleveland, OH (United States)

    2009-02-01

    Non-baryonic dark matter makes one quarter of the energy density of the Universe and is concentrated in the halos of galaxies, including the Milky Way. The Weakly Interacting Massive Particle (WIMP) is a dark matter candidate with a scattering cross section with an atomic nucleus of the order of the weak interaction and a mass comparable to that of an atomic nucleus. The Cryogenic Dark Matter Search (CDMS-II) experiment, using Ge and Si cryogenic particle detectors at the Soudan Underground Laboratory, aims to directly detect nuclear recoils from WIMP interactions. This thesis presents the first 5 tower WIMP-search results from CDMS-II, an estimate of the cosmogenic neutron backgrounds expected at the Soudan Underground Laboratory, and a proposal for a new measurement of high-energy neutrons underground to benchmark the Monte Carlo simulations. Based on the non-observation of WIMPs and using standard assumptions about the galactic halo [68], the 90% C.L. upper limit of the spin-independent WIMPnucleon cross section for the first 5 tower run is 6.6 × 10-44cm2 for a 60 GeV/c2 WIMP mass. A combined limit using all the data taken at Soudan results in an upper limit of 4.6×10-44cm2 at 90% C.L.for a 60 GeV/c2 WIMP mass. This new limit corresponds to a factor of ~3 improvement over any previous CDMS-II limit and a factor of ~2 above 60 GeV/c 2 better than any other WIMP search to date. This thesis presents an estimation, based on Monte Carlo simulations, of the nuclear recoils produced by cosmic-ray muons and their secondaries (at the Soudan site) for a 5 tower Ge and Si configuration as well as for a 7 supertower array. The results of the Monte Carlo are that CDMS-II should expect 0.06 ± 0.02+0.18 -0.02 /kgyear unvetoed single nuclear recoils in Ge for the 5 tower configuration, and 0.05 ± 0.01+0.15 -0.02 /kg-year for the 7 supertower configuration. The systematic error is based on the available

  15. Rational and design of an overfeeding protocol in constitutional thinness: Understanding the physiology, metabolism and genetic background of resistance to weight gain.

    Science.gov (United States)

    Ling, Yiin; Galusca, Bogdan; Hager, Jorg; Feasson, Leonard; Valsesia, Armand; Epelbaum, Jacques; Alexandre, Virginie; Wynn, Emma; Dinet, Cécile; Palaghiu, Radu; Peoc'h, Michel; Boirie, Yves; Montaurier, Christophe; Estour, Bruno; Germain, Natacha

    2016-10-01

    Constitutional thinness (CT) is a natural state of underweight (13-17.5kg/m 2 ) without the presence of any eating disorders and abnormal hormonal profile, and with preserved menses in women. We previously conducted a four-week fat overfeeding study showing weight gain resistance in CT women and one of our main results was the identification of an energy gap: a positive energy balance (higher energy intake than energy expenditure). This new overfeeding study is designed to confirm the energy gap and propose mechanistic hypothesis. A 2-week overfeeding (daily consumption of one bottle of Renutryl ® Booster (600kcal, 30g protein, 72g carbohydrate, 21g fat) on top of the dietary intake) is performed to compare 15 women and men in each CT group (Body Mass Index [BMI]controls (BMI 20-25kg/m 2 ). Bodyweight, food intake, energy expenditure (canopy, calorimetric chamber and Actiheart), body composition (DXA), appetite regulatory hormone profiles after a test meal, proteomics, metabolomics, urinary metabolic profiles, stool microbiome and lipids, fat and muscle transcriptomics are monitored before and after overfeeding. Data inter-linking will be able to be established with results of this study. The findings could possibly open to therapeutic approaches to help CT patients to gain weight as well as provide a better understanding of energy regulation with regard to treat obesity (resistance to weight loss), a mirror image of CT (resistance to weight gain). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Morphological and transcriptional response of an anhydrobiotic insect to ionizing radiation and desiccation: steps forward in understanding molecular background of extreme radioresistance in higher eukaryotes

    Science.gov (United States)

    Gusev, Oleg; Novikova, Nataliya; Sychev, Vladimir; Okuda, Takashi; Kikawada, Takahiro; Sakashita, Tetsuya; Mukae, Kyosuke

    2012-07-01

    Life in extreme or drastically changing environments in many cases leads to evolutionary evolvement of mechanisms of cross-resistance to different abiotic stresses, often never actually faced by the organism in its natural habitat. Larvae of the sleeping chironomidPolypedilum vanderplanki (Diptera) are able to resist complete desiccation and in the dry form survive under excess of various abiotic stresses, including exposure to space environment. One of the most intriguing features of the anhydrobiotic larvae is resistance to extremely high doses of different types of ionizing radiation. To understand the cross-tolerance mechanism, we have analyzed the structural changes in the nuclear DNA using transmission electron microscopy and DNA comet assays in relation to anhydrobiosis and radiation. We find that dehydration causes alterations in chromatin structure and a severe fragmentation of nuclear DNA in the cells of the larvae despite successful anhydrobiosis. The DNA fragmentation level and the recovery of DNA integrity in the rehydrated after anhydrobiosis larvae were similar to those of hydrated larvae irradiated with 70 Gy of high-linear energy transfer (LET) ions (4He+). In comparison, low-LET radiation (gamma rays) of the same dose causes less initial damage to the larvae, and recovery of DNA repair is complete within 24 h. Genome-wide analysis of mRNA expression in the larvae revealed that a large group of genes (including antioxidants, anhydrobiosis-specific biomolecules and protein-reparation enzymes) showed a similar patterns of activity in response to both desiccation and ionizing radiation. We conclude that t one of the factors explaining the relationship between the resistance to ionizing radiation and the ability to undergo anhydrobiosis in the sleeping chironomid would be an adaptation to desiccation-inflicted proteins and nuclear DNA damage.

  17. Model of a black hole gas submitted to background gravitational field for active galaxy nuclei with application to calculating the continuous emission spectra of massless particles (Photons: neutrinos and gravitons)

    International Nuclear Information System (INIS)

    Pinto Neto, A.

    1987-01-01

    A new theoretical model for active galaxy nuclei which describes the continuous spectrum of rest massless particles (photons, neutrinos and gravitons) in the frequency range from radiofrequency to gamma ray frequency, is presented. The model consists in a black hole gas interacting with a background gravitacional field. The previously models proposed for active galaxy nuclei are exposured. Whole theoretical fundaments based on Einstein general relativity theory for defining and studying singularity properties (black holes) are also presented. (M.C.K.) [pt

  18. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface groundwater: Background, base cases, shallow reservoirs, short-term gas, and water transport

    Science.gov (United States)

    Reagan, Matthew T; Moridis, George J; Keen, Noel D; Johnson, Jeffrey N

    2015-01-01

    Hydrocarbon production from unconventional resources and the use of reservoir stimulation techniques, such as hydraulic fracturing, has grown explosively over the last decade. However, concerns have arisen that reservoir stimulation creates significant environmental threats through the creation of permeable pathways connecting the stimulated reservoir with shallower freshwater aquifers, thus resulting in the contamination of potable groundwater by escaping hydrocarbons or other reservoir fluids. This study investigates, by numerical simulation, gas and water transport between a shallow tight-gas reservoir and a shallower overlying freshwater aquifer following hydraulic fracturing operations, if such a connecting pathway has been created. We focus on two general failure scenarios: (1) communication between the reservoir and aquifer via a connecting fracture or fault and (2) communication via a deteriorated, preexisting nearby well. We conclude that the key factors driving short-term transport of gas include high permeability for the connecting pathway and the overall volume of the connecting feature. Production from the reservoir is likely to mitigate release through reduction of available free gas and lowering of reservoir pressure, and not producing may increase the potential for release. We also find that hydrostatic tight-gas reservoirs are unlikely to act as a continuing source of migrating gas, as gas contained within the newly formed hydraulic fracture is the primary source for potential contamination. Such incidents of gas escape are likely to be limited in duration and scope for hydrostatic reservoirs. Reliable field and laboratory data must be acquired to constrain the factors and determine the likelihood of these outcomes. Key Points: Short-term leakage fractured reservoirs requires high-permeability pathways Production strategy affects the likelihood and magnitude of gas release Gas release is likely short-term, without additional driving forces PMID

  19. A review on the use of gas and steam turbine combined cycles as prime movers for large ships. Part I: Background and design

    International Nuclear Information System (INIS)

    Haglind, Fredrik

    2008-01-01

    The aim of the present paper is to review the prospects of using combined cycles as prime movers for large ships, like, container ships, tankers and bulk carriers. The paper is divided into three parts of which this paper constitutes Part I. Here, the environmental and human health concerns of international shipping are outlined. The regulatory framework relevant for shipping and the design of combined cycles are discussed. In Part II, previous work and experience are reviewed, and an overview of the implications of introducing combined cycles as prime movers is included. In Part III, marine fuels are discussed and the pollutant emissions of gas turbines are compared with those of two-stroke, slow-speed diesel engines. Environmental effects of shipping include contributions to the formation of ground-level ozone, acidification, eutrophication and climate impact. Tightening environmental regulations limit the fuel sulphur content and pollutant emissions. For moderate live steam pressures, a vertical HRSG of drum-type mounted directly over the gas turbine, is suggested to be a viable configuration that minimizes ground floor and space requirements

  20. Understanding the formation process of the liquid slug in a hilly-terrain wet natural gas pipeline

    DEFF Research Database (Denmark)

    Yang, Yan; Li, Jingbo; Wang, Shuli

    2017-01-01

    condition on the liquid slug formation is discussed including pipe diameter, inclination angle, gas superficial velocity and liquid holdup. The results show that the pipe is blocked by the liquid slug at the moment of slug formed. The pipe pressure suddenly increases, and then decreases gradually...... in the process of liquid slug formation and motion. The pipe pressure drop and liquid holdup decrease along with the increasing inclination angle of ascending pipe. On the contrary, they rise with the increase of the inclination angle of descending pipe. Higher gas superficial velocity and liquid holdup result...

  1. Field survey of Canadian background soils: Implications for a new mathematical gas chromatography-flame ionization detection approach for resolving false detections of petroleum hydrocarbons in clean soils.

    Science.gov (United States)

    Kelly-Hooper, Francine; Farwell, Andrea J; Pike, Glenna; Kennedy, Jocelyn; Wang, Zhendi; Grunsky, Eric C; Dixon, D George

    2014-08-01

    The reference method for the Canada-wide standard (CWS) for petroleum hydrocarbons (PHCs) in soil provides laboratories with methods for generating accurate and reproducible soil analysis results. The CWS PHC tier 1 generic soil-quality guidelines apply to 4 carbon ranges/fractions: F1 (C6-C10), F2 (C10-C16), F3 (C16-C34), and F4 (>C34). The methods and guidelines were developed and validated for soils with approximately 5% total organic carbon (TOC). However, organic soils have much higher TOC levels because of biogenic organic compounds (BOCs) originating from sources such as plant waxes and fatty acids. Coextracted BOCs can have elevated F2-F4 concentrations, which can cause false exceedances of PHC soil guidelines. The present study evaluated false PHC detections in soil samples collected from 34 background sites. The list of analytes included soil type, TOC, polycyclic aromatic hydrocarbons (PAHs), F2, F3, F4, F3a (C16-C22), and F3b (C22-C34). Soils with 3% to 41% TOC falsely exceeded the CWS PHC 300 mg/kg F3 coarse soil guideline. It was previously demonstrated that clean peat had F2:F3b ratios of less than 0.10, while crude oil spiked peat and spiked sand had higher ratios of greater than 0.10. In the present background study, all of the clean organic soils with at least 300 mg/kg F3 had F2:F3b ratios of less than 0.10, which indicated false guideline exceedances. Clean inorganic soils had low F3 concentrations, resulting in high F2:F3b ratios of greater than 0.10. Validation field studies are required to determine if the F2:F3b 0.10 PHC presence versus absence threshold value is applicable to crude oil- and diesel-contaminated sites. © 2014 SETAC.

  2. Non-collision backgrounds in ATLAS

    CERN Document Server

    Gibson, S M; The ATLAS collaboration

    2012-01-01

    The proton-proton collision events recorded by the ATLAS experiment are on top of a background that is due to both collision debris and non-collision components. The latter comprises of three types: beam-induced backgrounds, cosmic particles and detector noise. We present studies that focus on the first two of these. We give a detailed description of beam-related and cosmic backgrounds based on the full 2011 ATLAS data set, and present their rates throughout the whole data-taking period. Studies of correlations between tertiary proton halo and muon backgrounds, as well as, residual pressure and resulting beam-gas events seen in beam-condition monitors will be presented. Results of simulations based on the LHC geometry and its parameters will be presented. They help to better understand the features of beam-induced backgrounds in each ATLAS sub-detector. The studies of beam-induced backgrounds in ATLAS reveal their characteristics and serve as a basis for designing rejection tools that can be applied in physic...

  3. Understanding Natural Gas Methane Leakage from Buried Pipelines as Affected by Soil and Atmospheric Conditions - Field Scale Experimental and Modeling Study

    Science.gov (United States)

    Smits, K. M.; Mitton, M.; Moradi, A.; Chamindu, D. K.

    2017-12-01

    Reducing the amount of leaked natural gas (NG) from pipelines from production to use has become a high priority in efforts to cut anthropogenic emissions of methane. In addition to environmental impacts, NG leakage can cause significant economic losses and safety failures such as fires and explosions. However, tracking and evaluating NG pipeline leaks requires a better understanding of the leak from the source to the detector as well as more robust quantification methods. Although recent measurement-based approaches continue to make progress towards this end, efforts are hampered due to the complexity of leakage scenarios. Sub- surface transport of leaked NG from pipelines occurs through complex transport pathways due to soil heterogeneities and changes in soil moisture. Furthermore, it is affected by variable atmospheric conditions such as winds, frontal passages and rain. To better understand fugitive emissions from NG pipelines, we developed a field scale testbed that simulates low pressure gas leaks from pipe buried in soil. The system is equipped with subsurface and surface sensors to continuously monitor changes in soil and atmospheric conditions (e.g. moisture, pressure, temperature) and methane concentrations. Using this testbed, we are currently conducting a series of gas leakage experiments to study of the impact of subsurface (e.g. soil moisture, heterogeneity) and atmospheric conditions (near-surface wind and temperature) on the detected gas signals and establish the relative importance of the many pathways for methane migration between the source and the sensor location. Accompanying numerical modeling of the system using the multiphase transport simulator TOUGH2-EOS7CA demonstrates the influence of leak location and direction on gas migration. These findings will better inform leak detectors of the leak severity before excavation, aiding with safety precautions and work order categorization for improved efficiency.

  4. [ANALYSIS OF BACKGROUNDS AND LEVEL OF UNDERSTANDING OF TREATMENT OF POOR ADHERENCE AND DROPOUT CASES ON SUBLINGUAL IMMUNOTHERAPY FOR JAPANESE CEDAR POLLINOSIS IN THE FIRST FOLLOW-UP YEAR].

    Science.gov (United States)

    Kikkawa, Sayaka; Kamijo, Atsushi; Nakagome, Kazuyuki; Soma, Tomoyuki; Kobayashi, Takehito; Uchida, Yoshitaka; Morita, Eiji; Nagata, Makoto; Inoue, Tomoe; Kase, Yasuhiro

    We considered the factors of poor adherence to and dropout from sublingual immunotherapy (SLIT) by verifying patient backgrounds 1 year after start of treatment. We recruited 38 patients who began SLIT between November 2014 and September 2015. We analyzed their attributes and level of understanding of the treatment, and conducted a self-reported survey on factors behind dropout cases and poor adherence cases. Four patients dropped out 1 year after start of treatment. Three left for reasons related to anxiety about side effects. There were five cases of poor adherence. There was no significant difference between good adherence, poor adherence, and dropout regarding level of understanding of the treatment (p=0.59). In the comparison between good and poor adherence groups, except four dropout patients, the adherence tended to be poor in patients with short duration of disease, smoking patients, and young patients. Continuous rate of SLIT achieved about 90%, suggesting relatively high level of adherence. It appears possible that anxiety related to side effects could be a factor affecting dropout from SLIT. There was no significant difference regarding level of understanding of the treatment. The adherence tended to be poor in patients with short duration of disease, smoking patients, and young patients.

  5. Discovering the gas laws and understanding the kinetic theory of gases with an iPad app

    Science.gov (United States)

    Davies, Gary B.

    2017-07-01

    Carrying out classroom experiments that demonstrate Boyle’s law and Gay-Lussac’s law can be challenging. Even if we are able to conduct classroom experiments using pressure gauges and syringes, the results of these experiments do little to illuminate the kinetic theory of gases. However, molecular dynamics simulations that run on computers allow us to visualise the behaviour of individual particles and to link this behaviour to the bulk properties of the gas e.g. its pressure and temperature. In this article, I describe how to carry out ‘computer experiments’ using a commercial molecular dynamics iPad app called Atoms in Motion [1]. Using the app, I show how to obtain data from simulations that demonstrate Boyle’s law and Gay-Lussac’s law, and hence also the combined gas law.

  6. Realization of the low background neutrino detector Double Chooz. From the development of a high-purity liquid and gas handling concept to first neutrino data

    Energy Technology Data Exchange (ETDEWEB)

    Pfahler, Patrick

    2012-12-17

    produced and, together with all other ingredients of muon veto and buffer, delivered to the experiment, where they were mixed and tuned in due consideration of the individual requirements of the different liquids. For the filling and handling of the DC-far detector, the underground laboratory was equipped with a comprehensive liquid-handling, gas-handling and monitoring-system, which provides all necessary functions to flush, fill, operate and empty the detector safely. Using these systems, the DC-far detector was flushed and filled in accordance with an especially developed sequence, which considered critical filling points and avoided unnecessary stress on the different detector vessels. By the means of this, the far detector of Double Chooz could be filled without damaging the detector vessels. In addition, it could be demonstrated that the quality and cleanliness of the detector liquids were maintained during filling. As a result of this, Double Chooz was able to acquire first neutrino data and to publish its first result of {Theta}{sub 13} with sin{sup 2}(2{Theta}{sub 13})=0.109 {+-} 0.030(stat.) {+-} 0.025(syst.).

  7. Realization of the low background neutrino detector Double Chooz. From the development of a high-purity liquid and gas handling concept to first neutrino data

    International Nuclear Information System (INIS)

    Pfahler, Patrick

    2012-01-01

    , together with all other ingredients of muon veto and buffer, delivered to the experiment, where they were mixed and tuned in due consideration of the individual requirements of the different liquids. For the filling and handling of the DC-far detector, the underground laboratory was equipped with a comprehensive liquid-handling, gas-handling and monitoring-system, which provides all necessary functions to flush, fill, operate and empty the detector safely. Using these systems, the DC-far detector was flushed and filled in accordance with an especially developed sequence, which considered critical filling points and avoided unnecessary stress on the different detector vessels. By the means of this, the far detector of Double Chooz could be filled without damaging the detector vessels. In addition, it could be demonstrated that the quality and cleanliness of the detector liquids were maintained during filling. As a result of this, Double Chooz was able to acquire first neutrino data and to publish its first result of Θ 13 with sin 2 (2Θ 13 )=0.109 ± 0.030(stat.) ± 0.025(syst.).

  8. An Approach to Understanding Cohesive Slurry Settling, Mobilization, and Hydrogen Gas Retention in Pulsed Jet Mixed Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A.; Wells, Beric E.; Fort, James A.; Meyer, Perry A.

    2009-05-22

    The Hanford Waste Treatment and Immobilization Plant (WTP) is being designed and built to pretreat and vitrify a large portion of the waste in Hanford’s 177 underground waste storage tanks. Numerous process vessels will hold waste at various stages in the WTP. Some of these vessels have mixing-system requirements to maintain conditions where the accumulation of hydrogen gas stays below acceptable limits, and the mixing within the vessels is sufficient to release hydrogen gas under normal conditions and during off-normal events. Some of the WTP process streams are slurries of solid particles suspended in Newtonian fluids that behave as non-Newtonian slurries, such as Bingham yield-stress fluids. When these slurries are contained in the process vessels, the particles can settle and become progressively more concentrated toward the bottom of the vessels, depending on the effectiveness of the mixing system. One limiting behavior is a settled layer beneath a particle-free liquid layer. The settled layer, or any region with sufficiently high solids concentration, will exhibit non-Newtonian rheology where it is possible for the settled slurry to behave as a soft solid with a yield stress. In this report, these slurries are described as settling cohesive slurries.

  9. Understanding Chemical Equilibrium: The Role of Gas Phases and Mixing Contributions in the Minimum of Free Energy Plots

    Science.gov (United States)

    Tomba, J. Pablo

    2017-01-01

    The use of free energy plots to understand the concept of thermodynamic equilibrium has been shown to be of great pedagogical value in materials science. Although chemical equilibrium is also amenable to this kind of analysis, it is not part of the agenda of materials science textbooks. Something similar is found in chemistry branches, where free…

  10. Student Understanding of the First Law of Thermodynamics: Relating Work to the Adiabatic Compression of an Ideal Gas.

    Science.gov (United States)

    Loverude, Michael E.; Kautz, Christian H.; Heron, Paula R. L.

    2002-01-01

    Reports on an investigation of student understanding of the first law of thermodynamics. Involves students from a first-year university physics course and a second-year thermal physics course. Focuses on the ability of students to relate the first law to the adiabatic physics course. Discusses implications for thermal physics and mechanics…

  11. The Historical or the Contemporary Context: Which of the Two Ensures a Deeper Understanding of Gas Properties?

    Science.gov (United States)

    Milanovic, Vesna D.; Trivic, Dragica D.

    2017-01-01

    The aim of this research was to explore the effects of two approaches, designated as the historical and the contemporary one, on the level of students' understanding of the properties and the practical use of gases. Our research hypothesis was that the historical context of the discovery of gases and the study of their properties would deepen…

  12. Micropore analysis of polymer networks by gas sorption and 129Xe NMR spectroscopy: toward a better understanding of intrinsic microporosity.

    Science.gov (United States)

    Weber, Jens; Schmidt, Johannes; Thomas, Arne; Böhlmann, Winfried

    2010-10-05

    The microporosity of two microporous polymer networks is investigated in detail. Both networks are based on a central spirobifluorene motif but have different linker groups, namely, imide and thiophene units. The microporosity of the networks is based on the "polymers of intrinsic microporosity (PIM)" design strategy. Nitrogen, argon, and carbon dioxide were used as sorbates in order to analyze the microporosity in greater detail. The gas sorption data was analyzed with respect to important parameters such as specific surface area, pore volume, and pore size (distribution). It is shown that the results can be strongly model dependent and swelling effects have to be regarded. (129)Xe NMR was used as an independent technique for the estimation of the average pore size of the polymer networks. The results indicate that both networks are mainly ultramicroporous (pore sizes microporous matter might have a different micropore size in the solvent swollen/filled state that in the dry state.

  13. You can’t change what you can’t measure: Understanding greenhouse gas emissions in Costa Rica

    International Nuclear Information System (INIS)

    Madsen, Michael Amdi

    2015-01-01

    In Costa Rica climate change is a real concern. Sea level rise, climatic variability, and climate-induced disease outbreaks are likely to affect the availability of drinking water and threaten local amphibians and marine life. The country is committed to reducing its greenhouse gas emissions, and is now taking steps to learn how much greenhouse gases the dairy and agricultural sectors emit in order to determine what actions it can take to reduce the impact of climate change. “A lack of training, equipment and national laboratory mean that Cost Rica relies on international emission factors to estimate the emissions of greenhouse gases from agriculture,” said Ana Gabriela Pérez, a researcher at the University of Costa Rica, who is working to develop a national reference laboratory for the measurement of greenhouse gases in the country.

  14. Understanding non-energy use and carbon storage in Italy in the context of the greenhouse gas issue

    Energy Technology Data Exchange (ETDEWEB)

    Patel, M K [Fraunhofer-Institute for Systems and Innovation Research, Karlsruhe (Germany); Tosato, G [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Energia

    1997-10-01

    Fossil carbon dioxide emission (CO{sub 2}) are main reason for greenhouse effect and for climate changes. So far most attention has been paid to CO{sub 2} emissions from the combustion of fossil fuels. The IPCC guidelines to the calculation of national greenhouse gas emissions suggests to account for CO{sub 2} emissions from plastics and other materials produced from non energy use as emissions from wastes. In view of the refinement of IPCC guidelines, in this paper they will focus on non-energy use as a source of fossil CO{sub 2}. The first part deals with the Italian statistics on non-energy use and compares the accounting method with the practice of Germany and the Nederland. Secondly, they will try to reproduce these statistical data by developing a bottom-up model. And finally they will apply the IPCC approach for quantifying carbon storage in materials. and suggest ways to increase its accuracy.

  15. Understanding non-energy use and carbon storage in Italy in the context of the greenhouse gas issue

    International Nuclear Information System (INIS)

    Patel, M. K.; Tosato, G.

    1997-10-01

    Fossil carbon dioxide emission (CO 2 ) are main reason for greenhouse effect and for climate changes. So far most attention has been paid to CO 2 emissions from the combustion of fossil fuels. The IPCC guidelines to the calculation of national greenhouse gas emissions suggests to account for CO 2 emissions from plastics and other materials produced from non energy use as emissions from wastes. In view of the refinement of IPCC guidelines, in this paper they will focus on non-energy use as a source of fossil CO 2 . The first part deals with the Italian statistics on non-energy use and compares the accounting method with the practice of Germany and the Nederland. Secondly, they will try to reproduce these statistical data by developing a bottom-up model. And finally they will apply the IPCC approach for quantifying carbon storage in materials. and suggest ways to increase its accuracy

  16. Elements of gas dynamics

    CERN Document Server

    Liepmann, H W

    2001-01-01

    The increasing importance of concepts from compressible fluid flow theory for aeronautical applications makes the republication of this first-rate text particularly timely. Intended mainly for aeronautics students, the text will also be helpful to practicing engineers and scientists who work on problems involving the aerodynamics of compressible fluids. Covering the general principles of gas dynamics to provide a working understanding of the essentials of gas flow, the contents of this book form the foundation for a study of the specialized literature and should give the necessary background

  17. Understanding the Effect of Gas Dynamics in Plasma Gun Performance for Simulating Fusion Wall Response to Disruption Events

    Science.gov (United States)

    Riedel, Will; Underwood, Thomas; Righetti, Fabio; Cappelli, Mark

    2017-10-01

    In this work, the suitability of a pulsed coaxial plasma accelerator to simulate the interaction of edge-localized modes with plasma first wall materials is investigated. Experimental measurements derived from a suite of diagnostics are presented that focus on both the properties of the plasma flow and the manner in which such jets couple with material interfaces. Specific emphasis is placed on quantifying the variation in these properties using tungsten tokens exposed to the plasma plume as the gun volume is progressively filled with more neutral gas. These results are mapped to the operational dynamics of the gun via a time-resolved Schlieren cinematic visualization of the density gradient within the flow. Resulting videos indicate the existence of two distinct modes with vastly different characteristic timescales, spatial evolution, and plasma properties. Time resolved quantification of the associated plasma heat flux for both modes, including a range spanning 150 MW m-2 - 10 GW m-2, is presented using both a fast thermocouple gauge and an IR camera. Both diagnostics in conjunction with a heat transfer model provide an accurate description of the energy transfer dynamics and operational characteristics of plasma guns. This work is supported by the U.S. Department of Energy Stewardship Science Academic Program.

  18. Understanding the formative stage of technological innovation system development: The case of natural gas as an automotive fuel

    International Nuclear Information System (INIS)

    Suurs, Roald A.A.; Hekkert, Marko P.; Kieboom, Sander; Smits, Ruud E.H.M.

    2010-01-01

    This study contributes to insights into mechanisms that influence the successes and failures of emerging energy technologies. It is assumed that for an emerging technology to fruitfully develop, it should be fostered by a Technological Innovation System (TIS), which is the network of actors, institutions and technologies in which it is embedded. For an emerging technology a TIS has yet to be built up. This research focuses on the dynamics of this build-up process by mapping the development of seven key activities: so-called system functions. The main contribution revolves around the notion of cumulative causation, or the phenomenon that the build-up of a TIS accelerates due to system functions reinforcing each other over time. As an empirical basis, an analysis is provided of the historical development of the TIS around automotive natural gas technology in the Netherlands (1970-2007). The results show that this TIS undergoes a gradual build-up in the 1970s, followed by a breakdown in the 1980s and, again, a build-up from 2000 to 2007. It is shown that underlying these trends are different forms of cumulative causation, here called motors of innovation. The study provides strategic insights for practitioners that aspire to support such motors of innovation.

  19. Contribution to the understanding of ion-gas reactions in ICP-MS collision reaction cells: application to the resolution of isobaric and polyatomic interferences

    International Nuclear Information System (INIS)

    Quemet, A.

    2012-01-01

    Inductively Coupled Plasma Mass Spectrometry (ICP-MS) emerged as the most essential technique in inorganic analytical chemistry thanks to its numerous assets, particularly its flexibility, its sensitivity and its reproducibility. As part of the elementary and isotopic analysis of irradiated fuel and transmutation target, the analyst is faced with a complex mass spectrum, due to the presence of many radionuclides. ICP-MS can not differentiate ions with the same mass, which induces isobaric and polyatomic interferences when the ions at the same mass are different chemical species. Last generations of ICP-MS have introduced collision reaction cells. It can in situ reduce these isobaric or polyatomic interferences. The cell is a multipole (quadrupole, hexapole or octupole) device filled with a collision and/or reaction gas. The gas molecules collide or possibly react with the ion beam, which eliminates or reduces interferences. Such resolution of interferences is based on the difference of chemical behaviours between the analyte and the interfering species: the choice of the gas is crucial. A better understanding of the 'ion - gas' reaction should help choosing the reacting gases. Three ICP-MS, with the different cell geometries, were used for this study: Perkin Elmer Elan DRC e (quadrupole), Thermo Fischer X serie II (hexapole) and Agilent Technologies 7700x (octupole). The effects of the cell geometry on different experimental parameters and on the resolution of the 56 Fe + / 40 Ar 16 O + polyatomic interferences were examined to measure iron at trace or ultra-trace level. This preliminary study was applied to measure iron as impurities in uranium oxide, the method was then validated with a Certified Reference Material. The reactivities of transition metals (Zr, Ru, Pd, Ag, Cd, Sn), lanthanides (La, Ce, Nd, Sm, Eu, Gd, Dy, Er and Yb) and actinides (U, Np, Pu, Am and Cm), elements of interest in the nuclear field, are studied with numerous gases (O 2 , CO, CO 2 , N 2

  20. Understanding and Improvement of an Experiment Measuring Chemical Reaction Rates by Monitoring Volume Change of a Gas: On the Reaction between HCl(aq) and Mg(s)

    International Nuclear Information System (INIS)

    Bang, Jeong Ah; Yoon, Hee Sook; Jeong, Dae Hong; Choi, Won Ho

    2006-01-01

    In this study we analyzed and improved an experiment measuring chemical reaction rates introduced in the high school science textbooks through an understanding of the phenomena observed in carrying out the experiment. For this purpose, the contents of textbooks related to the experiment were analyzed, and the problems observed in carrying out the experiment were addressed through experimental analysis. When the experiment was carried out by the method of aquatic transposition presented in textbooks, the observed volume change of H 2 gas was delayed and chemical reaction rate was increased in the early stage of reaction period. To resolve these problems, an improved method for measuring the reaction rates was suggested. In the improved experiment the reaction rate was measured to be constant on time, which was interpreted in terms of the concentration of H + and the surface area of magnesium

  1. Natural gas in India

    International Nuclear Information System (INIS)

    Lefevre, Thierry; Todoc, Jessie L.

    1999-11-01

    Contains Executive Summary and Chapters on: Country background; Overview of the energy sector; Natural gas supply; Natural gas infrastructure; Natural gas infrastructure; Natural gas demand; Outlook-government policy reform and industry development, and Appendices on Global and regional energy and gas trends; Overview of India's investment policy, incentives and regulation; The ENRON Dabhol power project. (Author)

  2. Using Oil and Gas Well Log Records to Understand Possible Connections Between Wastewater Injection Zones and Usable Groundwater Aquifers in California

    Science.gov (United States)

    Shimabukuro, D.; Haugen, E. A.; Battistella, C.; Treguboff, E. W.; Kale, J. M.

    2015-12-01

    Although the disposal of produced water in wastewater injection wells has been occurring in California for decades, it is not clear whether injected fluids may be migrating into usable groundwater aquifers. One problem is the poor characterization of federally-protected (oil and gas well records collected by the California Division of Oil, Gas, and Geothermal Resources (DOGGR). These scanned records contain two useful sources of information. First, geophysical well logs, such those measuring resistivity and porosity, can be used to determine aquifer salinity. This allows a three-dimensional understanding of the distribution of protected groundwater. Second, driller's logs contain lithological descriptions at depth. These lithologies can be used to construct a three-dimensional texture model, which can then be used in a groundwater flow model. A large number of undergraduate researchers at CSU Sacramento and CSU Long Beach have been collecting information on well records in the Ventura Basin and the Southern San Joaquin Valley. Each well record is examined with basic metadata entered into an online database in an effort to identify appropriate geophysical well logs and driller's logs. High-quality driller's logs are coded and used to create three-dimensional framework models for each well field. The geophysical logs are digitized and will be used to determine aquifer salinity. In addition, we are using information from the DOGGR well records to investigate wellbore integrity, waste disposal and waterflood injection volumes, and the possibility of induced seismicity. This project is part of the broader effort of the California State Water Resources Control Board to implement Senate Bill 4.

  3. Advancing Understanding of Emissions from Oil and Natural Gas Production Operations to Support EPA’s Air Quality Modeling of Ozone Non-Attainment Areas; Final Summary Report

    Science.gov (United States)

    Executive Summary Environmentally responsible development of oil and gas assets requires well-developed emissions inventories and measurement techniques to verify emissions and the effectiveness of control strategies. To accurately model the oil and gas sector impacts on air qual...

  4. Aluminum as a source of background in low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Majorovits, B., E-mail: bela@mppmu.mpg.de [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Abt, I. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Laubenstein, M. [Laboratori Nazionali del Gran Sasso, INFN, S.S.17/bis, km 18 plus 910, I-67100 Assergi (Italy); Volynets, O. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)

    2011-08-11

    Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10{sup -5} counts/(kg y keV) in the region of interest around the Q-value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of {sup 22}Na, {sup 26}Al, {sup 226}Ra and {sup 228}Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

  5. To fully exert the important role of natural gas in building a modern energy security system in China: An understanding of China's National l3th Five-Year Plan for Natural Gas Development

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    2017-07-01

    Full Text Available Along with the introduction of 13th Five-Year Plans in succession for natural gas development programmed by governments at all levels and much more attention paid to haze governance by relevant departments, natural gas, as one of the major energy sources, has ushered in a strategic opportunity era. In view of this, based upon China's National 13th Five-Year Plan for Natural Gas Development formulated by the National Development and Reform Commission, the developing trend of natural gas sector was predicted in the period of 13th Five-Year Plan in terms of supply side, demand side, pricing system, infrastructure construction, etc. and some feasible proposals were made on the whole industrial chain. In terms of the supply side, natural gas will be of availability, accessibility, assurance, affordability, and accountability in the production and supply chains. In terms of the demand side, air pollution treatment will indirectly stimulate gas consumption increase. Gas power generation will become the dominant. Natural gas as a transportation fuel will bring a good new opportunity. Thus it is believed that as the present natural gas development is restricted by both gas pricing system and infrastructure construction, further reform should be strengthened to break the barriers of systems and mechanisms; and that due to many uncertainties in the natural gas market, the decisive role of market in the resource allocation should be fully exerted to ensure the main force of natural gas in building a dependable energy strategic system in present and future China.

  6. 39Ar/Ar measurements using ultra-low background proportional counters

    International Nuclear Information System (INIS)

    Hall, Jeter; Aalseth, Craig E.; Bonicalzi, Ricco M.; Brandenberger, Jill M.; Day, Anthony R.; Humble, Paul H.; Mace, Emily K.; Panisko, Mark E.; Seifert, Allen

    2016-01-01

    Age-dating groundwater and seawater using the 39 Ar/Ar ratio is an important tool to understand water mass-flow rates and mean residence time. Low-background proportional counters developed at Pacific Northwest National Laboratory use mixtures of argon and methane as counting gas. We demonstrate sensitivity to 39 Ar by comparing geological (ancient) argon recovered from a carbon dioxide gas well and commercial argon. The demonstrated sensitivity to the 39 Ar/Ar ratio is sufficient to date water masses as old as 1000 years. - Highlights: • 39 Ar/Ar age dating is important for understanding environmental water migration. • Ultra low background proportional counters have been developed. • 39 Ar is detected in atmospheric argon at a rate of 70.3 counts per day. The demonstrated background is 166 counts per day. • Age dating is possible for water with underground residence time of up to 1000 years.

  7. Brief Report: Understanding Intention to Be Physically Active and Physical Activity Behaviour in Adolescents from a Low Socio-Economic Status Background: An Application of the Theory of Planned Behaviour

    Science.gov (United States)

    Duncan, Michael J.; Rivis, Amanda; Jordan, Caroline

    2012-01-01

    The aim of this brief report is to report on the utility of the Theory of Planned Behaviour (TPB) for predicting the physical activity intentions and behaviour of British adolescents from lower-than-average socio-economic backgrounds. A prospective questionnaire design was employed with 197, 13-14 year olds (76 males, 121 females). At time 1…

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

    International Nuclear Information System (INIS)

    1993-04-01

    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

  9. Energy futures project : backgrounder for consultation sessions

    International Nuclear Information System (INIS)

    Bhargava, A.

    2006-05-01

    The National Energy Board periodically publishes a long-term energy and demand report as part of an ongoing monitoring program. The next report is planned for release in 2007. This background document provided background information to ensure that consultation participants have a common understanding of key issues to be addressed during the cross-country consultations that have been planned before the release of the final version of the report. An outline of the proposed analytical approach was presented, as well as details of major assumptions and scenario storylines. Scenario themes included: economic, energy and environmental sustainability; a security-focused world shaped by war and civil strife; and strong global economic growth fueled by the rapid growth of the Chinese and Indian economies. A methodology overview was provided as well as a reference case. Issues related to energy supply included oil; natural gas liquids; natural gas; and electricity. Issues related to energy demand included the residential sector; the commercial sector; the industrial sector; and the transportation sector. Historical trends and forecasts were outlined using the macroeconomic variable of interest. Supply, demand, and supporting infrastructure across all energy forms within a North American and global context were considered. The impact of environmental management strategies were reviewed, as well as the role of the government in shaping policies. It was concluded that the purpose of the final report is to serve as a standard of references for parties interested in Canadian energy issues and trends as well as to inform decision makers of key risks and uncertainties facing the energy future.9 tabs., 1 fig

  10. Understanding physics

    CERN Document Server

    Mansfield, Michael

    2011-01-01

    Understanding Physics - Second edition is a comprehensive, yet compact, introductory physics textbook aimed at physics undergraduates and also at engineers and other scientists taking a general physics course. Written with today's students in mind, this text covers the core material required by an introductory course in a clear and refreshing way. A second colour is used throughout to enhance learning and understanding. Each topic is introduced from first principles so that the text is suitable for students without a prior background in physics. At the same time the book is designed to enable

  11. Cosmic Microwave Background Timeline

    Science.gov (United States)

    Cosmic Microwave Background Timeline 1934 : Richard Tolman shows that blackbody radiation in an will have a blackbody cosmic microwave background with temperature about 5 K 1955: Tigran Shmaonov anisotropy in the cosmic microwave background, this strongly supports the big bang model with gravitational

  12. Combining soil and tree-stem flux measurements and soil gas profiles to understand CH4 pathways in Fagus sylvatica forests

    Czech Academy of Sciences Publication Activity Database

    Maier, M.; Macháčová, Kateřina; Lang, F.; Svobodová, Kateřina; Urban, Otmar

    2018-01-01

    Roč. 181, č. 1 (2018), s. 31-35 ISSN 1436-8730 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : ch4 * soil gas profile * gas flux * co2 * methanogenesis Subject RIV: ED - Physiology OBOR OECD: Plant sciences, botany Impact factor: 2.102, year: 2016

  13. Understanding Emissions from Control-Related Equipment used in Oil and Gas Production Operations to Support EPA’s Air Quality Modeling of Ozone Non-attainment Areas

    Science.gov (United States)

    Oil and gas production has increased significantly in the United States over the past ten years. Improperly maintained and controlled oil and gas extraction and production (E&P) processes have the potential to emit significant amounts of pollutants that can impact human health an...

  14. Teaching Teaching & Understanding Understanding

    DEFF Research Database (Denmark)

    2006-01-01

    "Teaching Teaching & Understanding Understanding" is a 19-minute award-winning short-film about teaching at university and higher-level educational institutions. It is based on the "Constructive Alignment" theory developed by Prof. John Biggs. The film delivers a foundation for understanding what...

  15. Optimal background matching camouflage.

    Science.gov (United States)

    Michalis, Constantine; Scott-Samuel, Nicholas E; Gibson, David P; Cuthill, Innes C

    2017-07-12

    Background matching is the most familiar and widespread camouflage strategy: avoiding detection by having a similar colour and pattern to the background. Optimizing background matching is straightforward in a homogeneous environment, or when the habitat has very distinct sub-types and there is divergent selection leading to polymorphism. However, most backgrounds have continuous variation in colour and texture, so what is the best solution? Not all samples of the background are likely to be equally inconspicuous, and laboratory experiments on birds and humans support this view. Theory suggests that the most probable background sample (in the statistical sense), at the size of the prey, would, on average, be the most cryptic. We present an analysis, based on realistic assumptions about low-level vision, that estimates the distribution of background colours and visual textures, and predicts the best camouflage. We present data from a field experiment that tests and supports our predictions, using artificial moth-like targets under bird predation. Additionally, we present analogous data for humans, under tightly controlled viewing conditions, searching for targets on a computer screen. These data show that, in the absence of predator learning, the best single camouflage pattern for heterogeneous backgrounds is the most probable sample. © 2017 The Authors.

  16. Northern pipelines : backgrounder

    International Nuclear Information System (INIS)

    2002-04-01

    Most analysts agree that demand for natural gas in North America will continue to grow. Favourable market conditions created by rising demand and declining production have sparked renewed interest in northern natural gas development. The 2002 Annual Energy Outlook forecasted U.S. consumption to increase at an annual average rate of 2 per cent from 22.8 trillion cubic feet to 33.8 TCF by 2020, mostly due to rapid growth in demand for electric power generation. Natural gas prices are also expected to increase at an annual average rate of 1.6 per cent, reaching $3.26 per thousand cubic feet in 2020. There are currently 3 proposals for pipelines to move northern gas to US markets. They include a stand-alone Mackenzie Delta Project, the Alaska Highway Pipeline Project, and an offshore route that would combine Alaskan and Canadian gas in a pipeline across the floor of the Beaufort Sea. Current market conditions and demand suggest that the projects are not mutually exclusive, but complimentary. The factors that differentiate northern pipeline proposals are reserves, preparedness for market, costs, engineering, and environmental differences. Canada has affirmed its role to provide the regulatory and fiscal certainty needed by industry to make investment decisions. The Government of the Yukon does not believe that the Alaska Highway Project will shut in Mackenzie Delta gas, but will instead pave the way for development of a new northern natural gas industry. The Alaska Highway Pipeline Project will bring significant benefits for the Yukon, the Northwest Territories and the rest of Canada. Unresolved land claims are one of the challenges that has to be addressed for both Yukon and the Northwest Territories, as the proposed Alaska Highway Pipeline will travel through traditional territories of several Yukon first Nations. 1 tab., 4 figs

  17. Effect of a background electric field on the Hagedorn temperature

    International Nuclear Information System (INIS)

    Ferrer, E.J.; Incera, V. de la; Fradkin, E.S.

    1990-07-01

    We compute the one-loop free energy of the open neutral string gas in a constant electromagnetic background. Starting from this result we show that the Hagedorn temperature of this hot string gas depends on the background electric field. The larger the electric field, the lower the Hagedorn temperature is. (author). 13 refs

  18. Cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1979-01-01

    The 20-ft horn-reflector antenna at Bell Laboratories is discussed in detail with emphasis on the 7.35 cm radiometer. The circumstances leading to the detection of the cosmic microwave background radiation are explored

  19. 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)....

  20. Natural gas leak mapper

    Science.gov (United States)

    Reichardt, Thomas A [Livermore, CA; Luong, Amy Khai [Dublin, CA; Kulp, Thomas J [Livermore, CA; Devdas, Sanjay [Albany, CA

    2008-05-20

    A system is described that is suitable for use in determining the location of leaks of gases having a background concentration. The system is a point-wise backscatter absorption gas measurement system that measures absorption and distance to each point of an image. The absorption measurement provides an indication of the total amount of a gas of interest, and the distance provides an estimate of the background concentration of gas. The distance is measured from the time-of-flight of laser pulse that is generated along with the absorption measurement light. The measurements are formated into an image of the presence of gas in excess of the background. Alternatively, an image of the scene is superimosed on the image of the gas to aid in locating leaks. By further modeling excess gas as a plume having a known concentration profile, the present system provides an estimate of the maximum concentration of the gas of interest.

  1. Background sources and masks for Mark II detector at PEP

    International Nuclear Information System (INIS)

    Kadyk, J.

    1981-06-01

    The shielding masks currently at use in several of the current experiments at PEP are the result of an early organized effort to understand the sources of particle background expected at PEP, followed by the evolution of the conceptual designs into actual hardware. The degree and kind of background particle loading which could be tolerated was expected to differ significantly among the different experiments, and several designs emerged from the common study. Qualitatively, the types of radiations studied were, Synchrotron Radiation (SR), Beam Gas Bremsstrahlung (BGB), and, to a limited extent others, e.g., Electroproduction (EP). Calculations will be given of predicted occupancies in the pipe counter and other sensitive elements at small radius, since these will be most susceptible to the SR and BGB backgrounds. The calculations presented in this note are specific to the Mark II detector. Some general statements will be made first about the character of each of the various types of backgrounds considered, then some detailed calculations made for application to the Mark II detector

  2. The natural radiation background

    International Nuclear Information System (INIS)

    Duggleby, J.C.

    1982-01-01

    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

  3. Effects of background radiation

    International Nuclear Information System (INIS)

    Knox, E.G.; Stewart, A.M.; Gilman, E.A.; Kneale, G.W.

    1987-01-01

    The primary objective of this investigation is to measure the relationship between exposure to different levels of background gamma radiation in different parts of the country, and different Relative Risks for leukaemias and cancers in children. The investigation is linked to an earlier analysis of the effects of prenatal medical x-rays upon leukaemia and cancer risk; the prior hypothesis on which the background-study was based, is derived from the earlier results. In a third analysis, the authors attempted to measure varying potency of medical x-rays delivered at different stages of gestation and the results supply a link between the other two estimates. (author)

  4. The cosmic microwave background

    International Nuclear Information System (INIS)

    Silk, J.

    1991-01-01

    Recent limits on spectral distortions and angular anisotropies in the cosmic microwave background are reviewed. The various backgrounds are described, and the theoretical implications are assessed. Constraints on inflationary cosmology dominated by cold dark matter (CDM) and on open cosmological models dominated by baryonic dark matter (BDM), with, respectively, primordial random phase scale-invariant curvature fluctuations or non-gaussian isocurvature fluctuations are described. More exotic theories are addressed, and I conclude with the 'bottom line': what theories expect experimentalists to be measuring within the next two to three years without having to abandon their most cherished theorists. (orig.)

  5. The Cosmic Background Explorer

    Science.gov (United States)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  6. Gas and Gas Pains

    Science.gov (United States)

    ... to produce gas. Often, relatively simple changes in eating habits can lessen bothersome gas. Certain digestive system disorders, ... such as soda and beer, increase stomach gas. Eating habits, such as eating too quickly, drinking through a ...

  7. Thermal background noise limitations

    Science.gov (United States)

    Gulkis, S.

    1982-01-01

    Modern detection systems are increasingly limited in sensitivity by the background thermal photons which enter the receiving system. Expressions for the fluctuations of detected thermal radiation are derived. Incoherent and heterodyne detection processes are considered. References to the subject of photon detection statistics are given.

  8. Berkeley Low Background Facility

    International Nuclear Information System (INIS)

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-01-01

    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

  9. Simulation of Experimental Background using FLUKA

    Energy Technology Data Exchange (ETDEWEB)

    Rokni, Sayed

    1999-05-11

    In November 1997, Experiment T423 began acquiring data with the intentions of understanding the energy spectra of high-energy neutrons generated in the interaction of electrons with lead. The following describes a series of FLUKA simulations studying (1) particle yields in the absence of all background; (2) the background caused from scattering in the room; (3) the effects of the thick lead shielding which surrounded the detector; (4) the sources of neutron background created in this lead shielding; and (5) the ratio of the total background to the ideal yield. In each case, particular attention is paid to the neutron yield.

  10. The isotropic radio background revisited

    Energy Technology Data Exchange (ETDEWEB)

    Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I–10125 Torino (Italy); Lineros, Roberto A. [Instituto de Física Corpuscular – CSIC/U. Valencia, Parc Científic, calle Catedrático José Beltrán, 2, E-46980 Paterna (Spain); Taoso, Marco, E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: taoso@cea.fr [Institut de Physique Théorique, CEA/Saclay, F-91191 Gif-sur-Yvette Cédex (France)

    2014-04-01

    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 emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky.

  11. The isotropic radio background revisited

    International Nuclear Information System (INIS)

    Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.; 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 emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky

  12. 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.

  13. Executive Summary - Historical background

    International Nuclear Information System (INIS)

    2005-01-01

    matter physics experiments at the High Flux Reactor of The Laue Langevin Institute and the ISIS spallation source at Rutherford-Appleton. Recently, we very actively entered the ICARUS neutrino collaboration and were invited to the PIERRE AUGER collaboration which will search for the highest energies in the Universe. Having close ties with CERN we are very actively engaged in CROSS-GRID, a large computer network project. To better understand the historical background of the INP development, it is necessary to add a few comments on financing of science in Poland. During the 70's and the 80's, research was financed through the so-called Central Research Projects for Science and Technical Development. The advantage of this system was that state-allocated research funds were divided only by a few representatives of the scientific community, which allowed realistic allocation of money to a small number of projects. After 1989 we were able to purchase commercially available equipment, which led to the closure of our large and very experienced electronic workshop. We also considerably reduced our well equipped mechanical shop. During the 90's the reduced state financing of science was accompanied by a newly established Committee of Scientific Research which led to the creation of a system of small research projects. This precluded the development of more ambitious research projects and led to the dispersion of equipment among many smaller laboratories and universities. A large research establishment, such as our Institute, could not develop properly under such conditions. In all, between 1989 and 2004 we reduced our personnel from about 800 to 470 and our infrastructure became seriously undercapitalised. However, with energetic search for research funds, from European rather than national research programs, we hope to improve and modernize our laboratories and their infrastructure in the coming years

  14. The BioSCWG Project: Understanding the Trade-Offs in the Process and Thermal Design of Hydrogen and Synthetic Natural Gas Production

    Directory of Open Access Journals (Sweden)

    Mohamed Magdeldin

    2016-10-01

    Full Text Available This article presents a summary of the main findings from a collaborative research project between Aalto University in Finland and partner universities. A comparative process synthesis, modelling and thermal assessment was conducted for the production of Bio-synthetic natural gas (SNG and hydrogen from supercritical water refining of a lipid extracted algae feedstock integrated with onsite heat and power generation. The developed reactor models for product gas composition, yield and thermal demand were validated and showed conformity with reported experimental results, and the balance of plant units were designed based on established technologies or state-of-the-art pilot operations. The poly-generative cases illustrated the thermo-chemical constraints and design trade-offs presented by key process parameters such as plant organic throughput, supercritical water refining temperature, nature of desirable coproducts, downstream indirect production and heat recovery scenarios. The evaluated cases favoring hydrogen production at 5 wt. % solid content and 600 °C conversion temperature allowed higher gross syngas and CHP production. However, mainly due to the higher utility demands the net syngas production remained lower compared to the cases favoring BioSNG production. The latter case, at 450 °C reactor temperature, 18 wt. % solid content and presence of downstream indirect production recorded 66.5%, 66.2% and 57.2% energetic, fuel-equivalent and exergetic efficiencies respectively.

  15. Understanding the dynamics of photoionization-induced nonlinear effects and solitons in gas-filled hollow-core photonic crystal fibers

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, Mohammed F.; Biancalana, Fabio [Max Planck Institute for the Science of Light, Guenther-Scharowsky Str. 1, DE-91058 Erlangen (Germany)

    2011-12-15

    We present the details of our previously formulated model [Saleh et al., Phys. Rev. Lett. 107, 203902 (2011)] that governs pulse propagation in hollow-core photonic crystal fibers filled by an ionizable gas. By using perturbative methods, we find that the photoionization process induces the opposite phenomenon of the well-known Raman self-frequency redshift of solitons in solid-core glass fibers, as was recently experimentally demonstrated [Hoelzer et al., Phys. Rev. Lett. 107, 203901 (2011)]. This process is only limited by ionization losses, and leads to a constant acceleration of solitons in the time domain with a continuous blueshift in the frequency domain. By applying the Gagnon-Belanger gauge transformation, multipeak ''inverted gravitylike'' solitary waves are predicted. We also demonstrate that the pulse dynamics shows the ejection of solitons during propagation in such fibers, analogous to what happens in conventional solid-core fibers. Moreover, unconventional long-range nonlocal interactions between temporally distant solitons, unique of gas plasma systems, are predicted and studied. Finally, the effects of higher-order dispersion coefficients and the shock operator on the pulse dynamics are investigated, showing that the conversion efficiency of resonant radiation into the deep UV can be improved via plasma formation.

  16. Background to EOHSI study

    International Nuclear Information System (INIS)

    Granville, G.

    2004-01-01

    This paper discusses ongoing public concerns regarding the health impacts of sour gas in Pincher Creek. A description of a 90 day toxicity study on hydrogen sulfide (H 2 S) at the Chemical Industry Institute of Toxicology (CIIT) in 3 strains of rodents was presented. A decade by decade review of events concerning gas emissions was provided, including a description of the 1980s lodgepole blowout and an introduction of a sulphide network in Alberta. The creation of a joint proposal for a comprehensive health review from Alberta researchers and the Canadian Association of Petroleum Producers (CAPP) was also outlined. The 1990s heralded an increased level of public participation in sour gas developments and health and odour issues. Details of the Ludwig saga were presented as well as further research studies and the Energy and Utilities Board (EUB) protocols, processes and hearings. In the 1990s, several human volunteer studies were conducted in response to public concerns about neurotoxicity and reproductive developmental effects. After the year 2000, continued public concern has been voiced at EUB hearings and at panel reviews of health effects. It was noted that development and research data has continued to be the cause of public concern and continued calls for additional work and reviews. However, no additional hazards have been identified with ongoing human volunteer studies, environmental levels and enhanced monitors research almost complete. It was concluded that current controversy seemed to downplay or ignore much of the available science. Human and animal data has consistently revealed that there is no evidence of neuro-developmental reproductive effects. It was recommended that power plays should be avoided and that the ongoing human volunteer study should eventually provide results. tabs, figs

  17. Background to EOHSI study

    Energy Technology Data Exchange (ETDEWEB)

    Granville, G. [Environmental Occupational Health Sciences Institute, Piscataway, NJ (United States)

    2004-07-01

    This paper discusses ongoing public concerns regarding the health impacts of sour gas in Pincher Creek. A description of a 90 day toxicity study on hydrogen sulfide (H{sub 2}S) at the Chemical Industry Institute of Toxicology (CIIT) in 3 strains of rodents was presented. A decade by decade review of events concerning gas emissions was provided, including a description of the 1980s lodgepole blowout and an introduction of a sulphide network in Alberta. The creation of a joint proposal for a comprehensive health review from Alberta researchers and the Canadian Association of Petroleum Producers (CAPP) was also outlined. The 1990s heralded an increased level of public participation in sour gas developments and health and odour issues. Details of the Ludwig saga were presented as well as further research studies and the Energy and Utilities Board (EUB) protocols, processes and hearings. In the 1990s, several human volunteer studies were conducted in response to public concerns about neurotoxicity and reproductive developmental effects. After the year 2000, continued public concern has been voiced at EUB hearings and at panel reviews of health effects. It was noted that development and research data has continued to be the cause of public concern and continued calls for additional work and reviews. However, no additional hazards have been identified with ongoing human volunteer studies, environmental levels and enhanced monitors research almost complete. It was concluded that current controversy seemed to downplay or ignore much of the available science. Human and animal data has consistently revealed that there is no evidence of neuro-developmental reproductive effects. It was recommended that power plays should be avoided and that the ongoing human volunteer study should eventually provide results. tabs, figs.

  18. Background estimates for PEP

    International Nuclear Information System (INIS)

    Martin, F.

    1975-04-01

    The beam gas bremsstrahlung radiation for PEP has been studied in detail using the ray trace program TURTLE. With this program, an electron (positron) trajectory starting at an interaction region is traced through the storage ring until it radiates, then the radiated electron is traced until it stops in the beam pipe. The relative number of electrons stopping between the strong focusing quadrupoles is used to determine a rate at which electromagnetic showers will occur in the region of the experimental apparatus. It was found that 2.46% of the radiated electrons will stop in the interaction region. Assuming a uniform pressure of 2 x 10/sup /minus/9/ Torr in the vacuum pipe for a residual gas (X/sub o/ = 34.7 gm/cm 2 ), 2.5 x 10 5 electrons (positrons) will stop in the interaction region per beam (4 x 10 12 electrons at 15 GeV) per second. If the luminosity is 10 32 , this rate is equivalent to a cross section of 2.5 x 10/sup /minus/27/ cm 2 . 4 figs., 3 tabs

  19. Gas war

    International Nuclear Information System (INIS)

    Shiry, J.

    1992-01-01

    The sale of natural gas to California is one of the most complex and contested trade disputes between the USA and Canada. The background and the issues involved are discussed. An oversupply of Canadian gas, combined with USA subsidies for producing coalbed methane and a general oversupply of gas in the USA, have made spot gas prices decline to unexpectedly low levels. California regulators have responded to this situation by trying to secure the lowest possible prices for consumers, thereby causing them to abandon long-standing trade policies with Canada. The main agent of this change is the California Public Utilities Commission (CPUC), whose actions have reduced the value of Canadian exports and Alberta government revenues by at least $250 million annually. CPUC supported buying from a supply pool (Alberta ampersand Southern Gas) since it provided monopoly purchasing power, and CPUC's policy against pipeline expansion produced the limited access to California that the CPUC now cites as evidence of a producer cartel. CPUC has interfered in contracts with Canadian producers in its pipeline access policies, its capacity brokering decision of 1991, and its reasonableness test for past sales. In its haste to force its own view of market results onto existing contractual relationships, the CPUC is not allowing open negotiations to reshape the relationship, and CPUC actions may be generating countermeasures by Alberta that are inappropriate under deregulation. 3 figs

  20. Using finite-difference waveform modeling to better understand rupture kinematics and path effects in ground motion modeling: an induced seismicity case study at the Groningen Gas field

    Science.gov (United States)

    Zurek, B.; Burnett, W. A.; deMartin, B.

    2017-12-01

    Ground motion models (GMMs) have historically been used as input in the development of probabilistic seismic hazard analysis (PSHA) and as an engineering tool to assess risk in building design. Generally these equations are developed from empirical analysis of observations that come from fairly complete catalogs of seismic events. One of the challenges when doing a PSHA analysis in a region where earthquakes are anthropogenically induced is that the catalog of observations is not complete enough to come up with a set of equations to cover all expected outcomes. For example, PSHA analysis at the Groningen gas field, an area of known induced seismicity, requires estimates of ground motions from tremors up to a maximum magnitude of 6.5 ML. Of the roughly 1300 recordable earthquakes the maximum observed magnitude to date has been 3.6ML. This paper is part of a broader study where we use a deterministic finite-difference wave-form modeling tool to compliment the traditional development of GMMs. Of particular interest is the sensitivity of the GMM's to uncertainty in the rupture process and how this scales to larger magnitude events that have not been observed. A kinematic fault rupture model is introduced to our waveform simulations to test the sensitivity of the GMMs to variability in the fault rupture process that is physically consistent with observations. These tests will aid in constraining the degree of variability in modeled ground motions due to a realistic range of fault parameters and properties. From this study it is our conclusion that in order to properly capture the uncertainty of the GMMs with magnitude up-scaling one needs to address the impact of uncertainty in the near field (risk. Further, by investigating and constraining the range of fault rupture scenarios and earthquake magnitudes on ground motion models, hazard and risk analysis in regions with incomplete earthquake catalogs, such as the Groningen gas field, can be better understood.

  1. 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....

  2. 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 recen...

  3. Electromagnetic wave collapse in a radiation background

    International Nuclear Information System (INIS)

    Marklund, Mattias; Brodin, Gert; Stenflo, Lennart

    2003-01-01

    The nonlinear interaction, due to quantum electrodynamical (QED) effects between an electromagnetic pulse and a radiation background, is investigated by combining the methods of radiation hydrodynamics with the QED theory for photon-photon scattering. For the case of a single coherent electromagnetic pulse, we obtain a Zakharov-like system, where the radiation pressure of the pulse acts as a driver of acoustic waves in the photon gas. For a sufficiently intense pulse and/or background energy density, there is focusing and the subsequent collapse of the pulse. The relevance of our results for various astrophysical applications are discussed

  4. Backgrounded but not peripheral

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    2013-01-01

    .e. the schema enters into apparently contradictory constructions of the informants’ local home-base and, possibly, of their identity (cf. Hovmark, 2010). Second, I discuss the status and role of the specific linguistic category in question, i.e. the directional adverbs. On the one hand we claim that the DDAs......In this paper I pay a closer look at the use of the CENTRE-PERIPHERY schema in context. I address two specific issues: first, I show how the CENTRE-PERIPHERY schema, encoded in the DDAs, enters into discourses that conceptualize and characterize a local community as both CENTRE and PERIPHERY, i......; 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...

  5. OCRWM Backgrounder, January 1987

    International Nuclear Information System (INIS)

    1987-01-01

    The Nuclear Waste Policy Act of 1982 (NWPA) assigns to the US Department of Energy (DOE) responsibility for developing a system to safely and economically transport spent nuclear fuel and high-level radioactive waste from various storage sites to geologic repositories or other facilities that constitute elements of the waste management program. This transportation system will evolve from technologies and capabilities already developed. Shipments of spent fuel to a monitored retrievable storage (MRS) facility could begin as early as 1996 if Congress authorizes its construction. Shipments of spent fuel to a geologic repository are scheduled to begin in 1998. The backgrounder provides an overview of DOE's cask development program. Transportation casks are a major element in the DOE nuclear waste transportation system because they are the primary protection against any potential radiation exposure to the public and transportation workers in the event an accident occurs

  6. Monitored background radiometer

    International Nuclear Information System (INIS)

    Ruel, C.

    1988-01-01

    A monitored background radiometer is described comprising: a thermally conductive housing; low conductivity support means mounted on the housing; a sensing plate mounted on the low conductivity support means and spaced from the housing so as to be thermally insulated from the housing and having an outwardly facing first surface; the sensing plate being disposed relative to the housing to receive direct electromagnetic radiation from sources exterior to the radiometer upon the first surface only; means for controllably heating the sensing plate; first temperature sensitive means to measure the temperature of the housing; and second temperature sensitive means to measure the temperature of the sensing plate, so that the heat flux at the sensing plate may be determined from the temperatures of the housing and sensing plate after calibration of the radiometer by measuring the temperatures of the housing and sensing plate while controllably heating the sensing plate

  7. Background and introduction

    DEFF Research Database (Denmark)

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

    2012-01-01

    expertise, the involvement in the process leading to this the book including a number of workshops, and a literature review of the development of their disciplinary fields: Facilities Management (FM), Corporate Real Estate Management (CREM) and Business to Business (B2B) Marketing. Findings: The difference......’ use of built facilities and the input side of business processes, while B2B marketing can concern the sale of any product or service and is related to the output side of business processes. The fields of FM, CREM and B2B marketing can all contribute to a better understanding of the added value of FM...

  8. 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...

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

    International Nuclear Information System (INIS)

    1993-04-01

    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

  10. Radiocarbon accelerator mass spectrometry: background and contamination

    International Nuclear Information System (INIS)

    Beukens, R.P.

    1993-01-01

    Since the advent of radiocarbon accelerator mass spectrometry (AMS) many studies have been conducted to understand the background from mass spectrometric processes and the origins of contamination associated with the ion source and sample preparation. By studying the individual contributions a better understanding of these processes has been obtained and it has been demonstrated that it is possible to date samples reliably up to 60 000 BP. (orig.)

  11. Note on bouncing backgrounds

    Science.gov (United States)

    de Haro, Jaume; Pan, Supriya

    2018-05-01

    The theory of inflation is one of the fundamental and revolutionary developments of modern cosmology that became able to explain many issues of the early Universe in the context of the standard cosmological model (SCM). However, the initial singularity of the Universe, where physics is indefinite, is still obscure in the combined SCM +inflation scenario. An alternative to SCM +inflation without the initial singularity is thus always welcome, and bouncing cosmology is an attempt at that. The current work is thus motivated to investigate the bouncing solutions in modified gravity theories when the background universe is described by the spatially flat Friedmann-Lemaître-Robertson-Walker (FLRW) geometry. We show that the simplest way to obtain the bouncing cosmologies in such spacetime is to consider some kind of Lagrangian whose gravitational sector depends only on the square of the Hubble parameter of the FLRW universe. For these modified Lagrangians, the corresponding Friedmann equation, a constraint in the dynamics of the Universe, depicts a curve in the phase space (H ,ρ ), where H is the Hubble parameter and ρ is the energy density of the Universe. As a consequence, a bouncing cosmology is obtained when this curve is closed and crosses the axis H =0 at least twice, and whose simplest particular example is the ellipse depicting the well-known holonomy corrected Friedmann equation in loop quantum cosmology (LQC). Sometimes, a crucial point in such theories is the appearance of the Ostrogradski instability at the perturbative level; however, fortunately enough, in the present work, as long as the linear level of perturbations is concerned, this instability does not appear, although it may appear at the higher order of perturbations.

  12. Extragalactic background light measurements and applications.

    Science.gov (United States)

    Cooray, Asantha

    2016-03-01

    This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in 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), centred at 1 μm, 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 γ-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 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB.

  13. Natural gas pricing

    International Nuclear Information System (INIS)

    Freedenthal, C.

    1993-01-01

    Natural gas pricing is the heart and soul of the gas business. Price specifically affects every phase of the industry. Too low a price will result in short supplies as seen in the mid-1970s when natural gas was scarce and in tight supply. To fully understand the pricing of this energy commodity, it is important to understand the total energy picture. In addition, the effect and impact of world and US economies, and economics in general are crucial to understanding natural gas pricing. The purpose of this presentation will be to show the parameters going into US natural gas pricing including the influence of the many outside industry factors like crude oil and coal pricing, market drivers pushing the gas industry, supply/demand parameters, risk management for buyers and sellers, and other elements involved in pricing analysis

  14. Global symmetries of open strings in an electromagnetic background

    International Nuclear Information System (INIS)

    Ferrer, E.J.; de la Incera, V.

    1994-01-01

    The global symmetries of open bosonic strings in an electromagnetic background are investigated. The Poincare subalgebra and the mass of the open charged string are derived. These results are useful for computing the background electric field dependence of the one-loop free energy and Hagedorn temperature of a neutral string gas

  15. Quantum background independence in string theory

    International Nuclear Information System (INIS)

    Witten, E.

    1994-01-01

    Not only in physical string theories, but also in some highly simplified situations, background independence has been difficult to understand. It is argued that the ''holomorphic anomaly'' of Bershadsky, Cecotti, Ooguri and Vafa gives a fundamental explanation of some of the problems. Moreover, their anomaly equation can be interpreted in terms of a rather peculiar quantum version of background independence: in systems afflicted by the anomaly, background independence does not hold order by order in perturbation theory, but the exact partition function as a function of the coupling constants has a background independent interpretation as a state in an auxiliary quantum Hilbert space. The significance of this auxiliary space is otherwise unknown. (author). 23 refs

  16. Retained Gas Sampling Results for the Flammable Gas Program

    International Nuclear Information System (INIS)

    Bates, J.M.; Mahoney, L.A.; Dahl, M.E.; Antoniak, Z.I.

    1999-01-01

    The key phenomena of the Flammable Gas Safety Issue are generation of the gas mixture, the modes of gas retention, and the mechanisms causing release of the gas. An understanding of the mechanisms of these processes is required for final resolution of the safety issue. Central to understanding is gathering information from such sources as historical records, tank sampling data, tank process data (temperatures, ventilation rates, etc.), and laboratory evaluations conducted on tank waste samples

  17. Retained Gas Sampling Results for the Flammable Gas Program

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Bates; L.A. Mahoney; M.E. Dahl; Z.I. Antoniak

    1999-11-18

    The key phenomena of the Flammable Gas Safety Issue are generation of the gas mixture, the modes of gas retention, and the mechanisms causing release of the gas. An understanding of the mechanisms of these processes is required for final resolution of the safety issue. Central to understanding is gathering information from such sources as historical records, tank sampling data, tank process data (temperatures, ventilation rates, etc.), and laboratory evaluations conducted on tank waste samples.

  18. Understanding PISA

    Directory of Open Access Journals (Sweden)

    Stephen DOWNES

    2005-04-01

    Full Text Available Understanding PISA Stephen DOWNESMoncton, CANADA ABSTRACT The headline was dramatic enough to cause a ripple in the reading public. "Students who use computers a lot at school have worse maths and reading performance," noted the BBC news article, citing a 2004 study by Ludger Woessmann and Thomas Fuchs (Fuchs and Woessman, 2004. It was not long before the blogosphere took notice. Taking the theme and running with it, Alice and Bill ask, "Computers Make School Kids Dumber?" They theorize, "If you track the admitted decline of education, you'll probably notice that it follows along with the increase of technology in the classroom." In a similar vein, James Bartholomew asks, "Do you think that the government will turn down the volume of its boasting about how it has spent billions introducing computers in schools (while keeping down the pay of teachers so much that there are shortages? Do you think it will stop sending governors of state schools glossy pamphlets about insisting that computers are used in their schools as much as possible?" In this study, therefore, PISA looks well beyond educational attainment, and also includes school demographics, such as whether it is a public or private school, has large or small classes, or has access or not to technological resources. Finally, it does measure student information-their family background, access to books and computers and parental support as well. The PISA survey departs from previous surveys in disregarding the stated curricula of the schools being measured. Therefore, the conclusion is not surprising, nor even wrong for him to consider independently of any parental or teacher support, considered without reference to the software running on it, considered without reference to student attitudes and interests, does not positively impact an education. Finally, he focus on missing the reporting of results

  19. Background noise levels in Europe

    OpenAIRE

    Gjestland, Truls

    2008-01-01

    - This report gives a brief overview of typical background noise levels in Europe, and suggests a procedure for the prediction of background noise levels based on population density. A proposal for the production of background noise maps for Europe is included.

  20. Gas turbine

    International Nuclear Information System (INIS)

    Yang, Ok Ryong

    2004-01-01

    This book introduces gas turbine cycle explaining general thing of gas turbine, full gas turbine cycle, Ericson cycle and Brayton cycle, practical gas turbine cycle without pressure loss, multiaxial type gas turbine cycle and special gas turbine cycle, application of basic theory on a study on suction-cooling gas turbine cycle with turbo-refrigerating machine using the bleed air, and general performance characteristics of the suction-cooling gas turbine cycle combined with absorption-type refrigerating machine.

  1. String Gas Cosmology

    OpenAIRE

    Brandenberger, Robert H.

    2008-01-01

    String gas cosmology is a string theory-based approach to early universe cosmology which is based on making use of robust features of string theory such as the existence of new states and new symmetries. A first goal of string gas cosmology is to understand how string theory can effect the earliest moments of cosmology before the effective field theory approach which underlies standard and inflationary cosmology becomes valid. String gas cosmology may also provide an alternative to the curren...

  2. More natural gas

    International Nuclear Information System (INIS)

    Leprince, P.; Valais, M.

    1993-01-01

    This paper reports that large resources and growing markets are the salient prospects of natural gas for the coming decades. The greater impact of natural gas on the worldwide energy market can become a reality if several scientific disciplines can be mobilized in order to succeed in cutting production costs. Modeling, mechanics of complex fluids, and physical chemistry of interfaces are basic disciplines for understanding and mastering the gas processing technologies

  3. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Center for Mountain Ecosystem Studies, Kunming Institute of Botany of the Chinese Academy of Sciences, China: $1,526,000 to inform effective water governance in the Asian highlands of China, Nepal, and Pakistan. • Ashoka Trust for Research in Ecology and the Environment (ATREE), India: $1,499,300 for research on ...

  4. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    demographic trends, socio-economic development pathways, and strong ... knowledge and experience, and encourage innovation. ... choices, and will work with stakeholders in government, business, civil society, and regional economic.

  5. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Safe and Inclusive Cities: ... improving urban environments and public spaces might have on reducing the city's high ... violence against women among urban youth of working class neighbourhoods of Islamabad, Rawalpindi, and Karachi,.

  6. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    CARIAA's research agenda addresses gaps and priorities highlighted in the ... Research focuses on climate risk, institutional and regulatory frameworks, markets, and ... The researchers will identify relevant drivers and trends and use develop ...

  7. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    Corey Piccioni

    achieving long‐term food security in Africa, with a focus on post‐harvest loss, ... nutrion and health, and the socio‐economic factors that affect food supply ... Water use. Agricultural producvity in sub‐Saharan Africa is the lowest in the world.

  8. 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.

  9. 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.

  10. Diffuse Cosmic Infrared Background Radiation

    Science.gov (United States)

    Dwek, Eli

    2002-01-01

    The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

  11. Background current of radioisotope manometer

    International Nuclear Information System (INIS)

    Vydrik, A.A.

    1987-01-01

    The technique for calculating the main component of the background current of radioisotopic monometers, current from direct collision of ionizing particles and a collector, is described. The reasons for appearance of background photoelectron current are clarified. The most effective way of eliminating background current components is collector protection from the source by a screen made of material with a high gamma-quanta absorption coefficient, such as lead, for example

  12. 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

  13. Backgrounds and characteristics of arsonists

    NARCIS (Netherlands)

    Labree, W.; Nijman, H.L.I.; Marle, H.J.C. van; Rassin, E.

    2010-01-01

    The aim of this study was to gain more insight in the backgrounds and characteristics of arsonists. For this, the psychiatric, psychological, personal, and criminal backgrounds of all arsonists (n = 25), sentenced to forced treatment in the maximum security forensic hospital “De Kijvelanden”, were

  14. Measurement of natural background neutron

    CERN Document Server

    Li Jain, Ping; Tang Jin Hua; Tang, E S; Xie Yan Fong

    1982-01-01

    A high sensitive neutron monitor is described. It has an approximate counting rate of 20 cpm for natural background neutrons. The pulse amplitude resolution, sensitivity and direction dependence of the monitor were determined. This monitor has been used for natural background measurement in Beijing area. The yearly average dose is given and compared with the results of KEK and CERN.

  15. Global gas company profiles

    International Nuclear Information System (INIS)

    1997-01-01

    This report provides a detailed assessment of 60 of the top gas companies form around the world, analysing them according to their internal dynamics and in relation to their competitors. It devotes each chapter to an individual company, providing invaluable insight into the organisation's operational background, financial performance and strategic goals. Using the most up-to-date information available, Global Gas Company Profiles allows you to make detailed analysis of each company's performance and future direction. (author)

  16. JEM-X background models

    DEFF Research Database (Denmark)

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

    2003-01-01

    Background and determination of its components for the JEM-X X-ray telescope on INTEGRAL are discussed. A part of the first background observations by JEM-X are analysed and results are compared to predictions. The observations are based on extensive imaging of background near the Crab Nebula...... on 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...... 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...

  17. Natural gas purchasing

    International Nuclear Information System (INIS)

    Freedenthal, C.

    1993-01-01

    In recent years, natural gas has gained new momentum because of changes in marketing and regulations. The gas industry has always received an inordinate amount of regulatory control starting at the well head where the gas is produced to the consuming burner tip. Regulations have drastically impacted the availability of gas. Changes in the marketing and regulations have made the natural gas market sensitive at the point of production, the well head. Now, with plentiful supply and ease of transportation to bring the gas from the producing fields to the consumer, natural gas markets are taking advantage of the changed conditions. At the same time, new markets are developing to take advantage of the changes. This section shows consumers, especially the energy planners for large buyers of fuel, the advantages, sources and new methods of securing natural gas supplies. Background on how natural gas is produced and marketed are given. This section lists marketing sources, regulatory agencies and information groups available to help buyers and consumers of this important fuel for US industries and residences. 7 figs., 8 tabs

  18. Stochastic backgrounds of gravitational waves

    International Nuclear Information System (INIS)

    Maggiore, M.

    2001-01-01

    We review the motivations for the search for stochastic backgrounds of gravitational waves and we compare the experimental sensitivities that can be reached in the near future with the existing bounds and with the theoretical predictions. (author)

  19. Berkeley Low Background Counting Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Sensitive low background assay detectors and sample analysis are available for non-destructive direct gamma-ray assay of samples. Neutron activation analysis is also...

  20. Spectral characterization of natural backgrounds

    Science.gov (United States)

    Winkelmann, Max

    2017-10-01

    As the distribution and use of hyperspectral sensors is constantly increasing, the exploitation of spectral features is a threat for camouflaged objects. To improve camouflage materials at first the spectral behavior of backgrounds has to be known to adjust and optimize the spectral reflectance of camouflage materials. In an international effort, the NATO CSO working group SCI-295 "Development of Methods for Measurements and Evaluation of Natural Background EO Signatures" is developing a method how this characterization of backgrounds has to be done. It is obvious that the spectral characterization of a background will be quite an effort. To compare and exchange data internationally the measurements will have to be done in a similar way. To test and further improve this method an international field trial has been performed in Storkow, Germany. In the following we present first impressions and lessons learned from this field campaign and describe the data that has been measured.

  1. Cosmic microwave background, where next?

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Ground-based, balloon-borne and space-based experiments will observe the Cosmic Microwave Background in greater details to address open questions about the origin and the evolution of the Universe. In particular, detailed observations the polarization pattern of the Cosmic Microwave Background radiation have the potential to directly probe physics at the GUT scale and illuminate aspects of the physics of the very early Universe.

  2. 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.

  3. Understanding Alzheimer's

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Understanding Alzheimer's Past Issues / Fall 2007 Table of Contents For ... and brain scans. No treatment so far stops Alzheimer's. However, for some in the disease's early and ...

  4. Physiologic correlates to background noise acceptance

    Science.gov (United States)

    Tampas, Joanna; Harkrider, Ashley; Nabelek, Anna

    2004-05-01

    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.

  5. Looking for Cosmic Neutrino Background

    Directory of Open Access Journals (Sweden)

    Chiaki eYanagisawa

    2014-06-01

    Full Text Available Since the discovery of neutrino oscillation in atmospheric neutrinos by the Super-Kamiokande experiment in 1998, study of neutrinos has been one of exciting fields in high-energy physics. All the mixing angles were measured. Quests for 1 measurements of the remaining parameters, the lightest neutrino mass, the CP violating phase(s, and the sign of mass splitting between the mass eigenstates m3 and m1, and 2 better measurements to determine whether the mixing angle theta23 is less than pi/4, are in progress in a well-controlled manner. Determining the nature of neutrinos, whether they are Dirac or Majorana particles is also in progress with continuous improvement. On the other hand, although the ideas of detecting cosmic neutrino background have been discussed since 1960s, there has not been a serious concerted effort to achieve this goal. One of the reasons is that it is extremely difficult to detect such low energy neutrinos from the Big Bang. While there has been tremendous accumulation of information on Cosmic Microwave Background since its discovery in 1965, there is no direct evidence for Cosmic Neutrino Background. The importance of detecting Cosmic Neutrino Background is that, although detailed studies of Big Bang Nucleosynthesis and Cosmic Microwave Background give information of the early Universe at ~a few minutes old and ~300 k years old, respectively, observation of Cosmic Neutrino Background allows us to study the early Universe at $sim$ 1 sec old. This article reviews progress made in the past 50 years on detection methods of Cosmic Neutrino Background.

  6. 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.

  7. Fluctuations in the cosmic microwave background

    International Nuclear Information System (INIS)

    Banday, A.J.; Wolfendale, A.W.

    1990-01-01

    In view of the importance to contemporary cosmology, and to our understanding of the Universe, of the precise nature of the Cosmic Microwave Background (CMB) spectrum, we consider the effects on this spectrum of contamination by other radiation fields of both galactic and extragalactic origin. Particular attention is given to the significance of measurements of the fluctuations in the 'background' radiation detected at 10.46 GHz and we conclude that these fluctuations are of the same magnitude as those expected from galactic cosmic-ray effects. A more detailed study of the cosmic-ray induced fluctuations and measurements at higher frequencies will be needed before genuine CMB fluctuations can be claimed. (author)

  8. Introduction to radiation backgrounds in a B factory

    International Nuclear Information System (INIS)

    Khan, S.

    1992-08-01

    Detector backgrounds in a B factory due to synchrotron radiation and beam-gas interactions are discussed and the computational tools to simulate these processes are outlined. As an example of their application, simulations and beam tests that preceded the installation of the ARGUS silicon vertex detector are described. (orig.)

  9. Low background techniques for SuperNEMO

    International Nuclear Information System (INIS)

    Liu, Xin Ran; Mott, James

    2015-01-01

    The UK contribution to achieving the ultra-low background conditions required inside the detectors of the SuperNEMO experiment are described. A dedicated facility has been established for the screening and selection of materials through gamma ray spectroscopy using germanium detectors. Initial results from two detectors are shown. The radon level inside the SuperNEMO detector must be less than 150 μBq/m 3 in order to achieve the target sensitivity. A Radon Concentration Line (RnCL) has been developed capable of measuring radon levels in large gas volumes down to 5 μBq/m 3 , improving on standard state-of-the-art radon detectors by 3 orders of magnitude. The development, commissioning and first measurements of radon content using the RnCL are also presented. (paper)

  10. Embodied Understanding

    Directory of Open Access Journals (Sweden)

    Mark Leonard Johnson

    2015-06-01

    Full Text Available Western culture has inherited a view of understanding as an intellectual cognitive operation of grasping of concepts and their relations. However, cognitive science research has shown that this received intellectualist conception is substantially out of touch with how humans actually make and experience meaning. The view emerging from the mind sciences recognizes that understanding is profoundly embodied, insofar as our conceptualization and reasoning recruit sensory, motor, and affective patterns and processes to structure our understanding of, and engagement with, our world. A psychologically realistic account of understanding must begin with the patterns of ongoing interaction between an organism and its physical and cultural environments and must include both our emotional responses to changes in our body and environment, and also the actions by which we continuously transform our experience. Consequently, embodied understanding is not merely a conceptual/propositional activity of thought, but rather constitutes our most basic way of being in, and engaging with, our surroundings in a deep visceral manner.

  11. 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.

  12. LOFT gamma densitometer background fluxes

    International Nuclear Information System (INIS)

    Grimesey, R.A.; McCracken, R.T.

    1978-01-01

    Background gamma-ray fluxes were calculated at the location of the γ densitometers without integral shielding at both the hot-leg and cold-leg primary piping locations. The principal sources for background radiation at the γ densitometers are 16 N activity from the primary piping H 2 O and γ radiation from reactor internal sources. The background radiation was calculated by the point-kernel codes QAD-BSA and QAD-P5A. Reasonable assumptions were required to convert the response functions calculated by point-kernel procedures into the gamma-ray spectrum from reactor internal sources. A brief summary of point-kernel equations and theory is included

  13. A definition of background independence

    International Nuclear Information System (INIS)

    Gryb, Sean

    2010-01-01

    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.

  14. Natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, J W

    1967-08-01

    This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

  15. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  16. Gas Sensor

    KAUST Repository

    Luebke, Ryan; Eddaoudi, Mohamed; Omran, Hesham; Belmabkhout, Youssef; Shekhah, Osama; Salama, Khaled N.

    2015-01-01

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  17. 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.

  18. Background metric in supergravity theories

    International Nuclear Information System (INIS)

    Yoneya, T.

    1978-01-01

    In supergravity theories, we investigate the conformal anomaly of the path-integral determinant and the problem of fermion zero modes in the presence of a nontrivial background metric. Except in SO(3) -invariant supergravity, there are nonvanishing conformal anomalies. As a consequence, amplitudes around the nontrivial background metric contain unpredictable arbitrariness. The fermion zero modes which are explicitly constructed for the Euclidean Schwarzschild metric are interpreted as an indication of the supersymmetric multiplet structure of a black hole. The degree of degeneracy of a black hole is 2/sup 4n/ in SO(n) supergravity

  19. 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.

  20. Children of ethnic minority backgrounds

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    2010-01-01

    media products and toys just as they will have knowledge of different media texts, play genres, rhymes etc. This has consequences for their ability to access social settings, for instance in play. New research in this field will focus on how children themselves make sense of this balancing of cultures......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...

  1. Generative electronic background music system

    International Nuclear Information System (INIS)

    Mazurowski, Lukasz

    2015-01-01

    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. Understanding Maple

    CERN Document Server

    Thompson, Ian

    2016-01-01

    Maple is a powerful symbolic computation system that is widely used in universities around the world. This short introduction gives readers an insight into the rules that control how the system works, and how to understand, fix, and avoid common problems. Topics covered include algebra, calculus, linear algebra, graphics, programming, and procedures. Each chapter contains numerous illustrative examples, using mathematics that does not extend beyond first-year undergraduate material. Maple worksheets containing these examples are available for download from the author's personal website. The book is suitable for new users, but where advanced topics are central to understanding Maple they are tackled head-on. Many concepts which are absent from introductory books and manuals are described in detail. With this book, students, teachers and researchers will gain a solid understanding of Maple and how to use it to solve complex mathematical problems in a simple and efficient way.

  3. Gas manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Fell, J W

    1915-05-03

    Retorts for the distillation of shale or coal for the production of oil or illuminating-gas are heated by gas from a generator or a gas-holder, and a portion of the gas from the flue leading to the heating-flues is forced by a steam jet through a by-pass and is injected into the bottom of the retorts. If the gas to be admitted to the retort is cold, it is first heated.

  4. Natural Gas

    OpenAIRE

    Bakar, Wan Azelee Wan Abu; Ali, Rusmidah

    2010-01-01

    Natural gas fuel is a green fuel and becoming very demanding because it is environmental safe and clean. Furthermore, this fuel emits lower levels of potentially harmful by-products into the atmosphere. Most of the explored crude natural gas is of sour gas and yet, very viable and cost effective technology is still need to be developed. Above all, methanation technology is considered a future potential treatment method for converting the sour natural gas to sweet natural gas.

  5. Precise muon drift tube detectors for high background rate conditions

    Energy Technology Data Exchange (ETDEWEB)

    Engl, Albert

    2011-08-04

    The muon spectrometer of the ATLAS-experiment at the Large Hadron Collider consists of drift tube chambers, which provide the precise measurement of trajectories of traversing muons. In order to determine the momentum of the muons with high precision, the measurement of the position of the muon in a single tube has to be more accurate than {sigma}{<=}100 {mu}m. The large cross section of proton-proton-collisions and the high luminosity of the accelerator cause relevant background of neutrons and {gamma}s in the muon spectrometer. During the next decade a luminosity upgrade to 5.10{sup 34} cm{sup -2}s{sup -1} is planned, which will increase the background counting rates considerably. In this context this work deals with the further development of the existing drift chamber technology to provide the required accuracy of the position measurement under high background conditions. Two approaches of improving the drift tube chambers are described: - In regions of moderate background rates a faster and more linear drift gas can provide precise position measurement without changing the existing hardware. - At very high background rates drift tube chambers consisting of tubes with a diameter of 15 mm are a valuable candidate to substitute the CSC muon chambers. The single tube resolution of the gas mixture Ar:CO{sub 2}:N{sub 2} in the ratio of 96:3:1 Vol %, which is more linear and faster as the currently used drift gas Ar:CO{sub 2} in the ratio of 97:3 Vol %, was determined at the Cosmic Ray Measurement Facility at Garching and at high {gamma}-background counting rates at the Gamma Irradiation Facility at CERN. The alternative gas mixture shows similar resolution without background. At high background counting rates it shows better resolution as the standard gas. To analyse the data the various parts of the setup have to be aligned precisely to each other. The change to an alternative gas mixture allows the use of the existing hardware. The second approach are drift tubes

  6. The future of UK gas producers

    International Nuclear Information System (INIS)

    Hallas, P.A.

    1991-01-01

    Traditionally, an oil company wishing to develop UK gas reserves almost always faced a protracted gas sales negotiation with British Gas. British Gas then had an effective monopoly in the resale of that gas to final consumers. This traditional pattern is now in a process of fundamental change, as a result of recent UK gas market re-regulation and the emergence of a new large scale opportunity to sell gas for power generation. The impact of these changes is still not very well understood outside a relatively small group of gas specialists but is likely to be significant for British Gas, consumers and UK gas producers. This paper outlines the background to the recent changes, the possible future of UK gas marketing and the likely impact on gas producers in the North Sea

  7. 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...

  8. Teaching about Natural Background Radiation

    Science.gov (United States)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  9. Educational Choice. A Background Paper.

    Science.gov (United States)

    Quality Education for Minorities Network, Washington, DC.

    This paper addresses school choice, one proposal to address parental involvement concerns, focusing on historical background, definitions, rationale for advocating choice, implementation strategies, and implications for minorities and low-income families. In the past, transfer payment programs such as tuition tax credits and vouchers were…

  10. Kerr metric in cosmological background

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, P C [Gujarat Univ., Ahmedabad (India). Dept. of Mathematics

    1977-06-01

    A metric satisfying Einstein's equation is given which in the vicinity of the source reduces to the well-known Kerr metric and which at large distances reduces to the Robertson-Walker metric of a nomogeneous cosmological model. The radius of the event horizon of the Kerr black hole in the cosmological background is found out.

  11. 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.

    2015-11-16

    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 ...

  12. Understanding Federalism.

    Science.gov (United States)

    Hickok, Eugene W., Jr.

    1990-01-01

    Urges returning to the original federalist debates to understand contemporary federalism. Reviews "The Federalist Papers," how federalism has evolved, and the centralization of the national government through acts of Congress and Supreme Court decisions. Recommends teaching about federalism as part of teaching about U.S. government…

  13. Understanding Energy

    Science.gov (United States)

    Menon, Deepika; Shelby, Blake; Mattingly, Christine

    2016-01-01

    "Energy" is a term often used in everyday language. Even young children associate energy with the food they eat, feeling tired after playing soccer, or when asked to turn the lights off to save light energy. However, they may not have the scientific conceptual understanding of energy at this age. Teaching energy and matter could be…

  14. RPC understanding and future perspectives

    CERN Document Server

    Santonico, R

    2004-01-01

    The understanding of the long-term behavior of the RPCs developed as dedicated muon trigger detectors at LHC and presently in construction, is analyzed. The main aging mechanisms are reviewed. The gas contamination by the hydrofluoric acid is analyzed as a possible aging cause and a method for measuring the fluorine concentration in the exhaust gas is described. Finally, the use of RPCs for the detection of Cosmic Ray Extensive Air Showers and their imaging capabilities are briefly discussed.

  15. Gas gun dynamics

    International Nuclear Information System (INIS)

    Denny, Mark

    2013-01-01

    The mechanics and thermodynamics of one- and two-stage gas guns are developed. Very high projectile muzzle speed can be obtained by the two-stage version. The physics of simple gas guns, such as air rifles, is accessible to undergraduates and the same level of presentation is used here to understand more complex designs. Numerical solutions to the equations of motion are shown, along with insightful analytic approximations. (paper)

  16. The Cosmic Infrared Background Experiment

    Science.gov (United States)

    Bock, James; Battle, J.; Cooray, A.; Hristov, V.; Kawada, M.; Keating, B.; Lee, D.; Matsumoto, T.; Matsuura, S.; Nam, U.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2009-01-01

    We are developing the Cosmic Infrared Background ExpeRiment (CIBER) to search for signatures of first-light galaxy emission in the extragalactic background. The first generation of stars produce characteristic signatures in the near-infrared extragalactic background, including a redshifted Ly-cutoff feature and a characteristic fluctuation power spectrum, that may be detectable with a specialized instrument. CIBER consists of two wide-field cameras to measure the fluctuation power spectrum, and a low-resolution and a narrow-band spectrometer to measure the absolute background. The cameras will search for fluctuations on angular scales from 7 arcseconds to 2 degrees, where the first-light galaxy spatial power spectrum peaks. The cameras have the necessary combination of sensitivity, wide field of view, spatial resolution, and multiple bands to make a definitive measurement. CIBER will determine if the fluctuations reported by Spitzer arise from first-light galaxies. The cameras observe in a single wide field of view, eliminating systematic errors associated with mosaicing. Two bands are chosen to maximize the first-light signal contrast, at 1.6 um near the expected spectral maximum, and at 1.0 um; the combination is a powerful discriminant against fluctuations arising from local sources. We will observe regions of the sky surveyed by Spitzer and Akari. The low-resolution spectrometer will search for the redshifted Lyman cutoff feature in the 0.7 - 1.8 um spectral region. The narrow-band spectrometer will measure the absolute Zodiacal brightness using the scattered 854.2 nm Ca II Fraunhofer line. The spectrometers will test if reports of a diffuse extragalactic background in the 1 - 2 um band continues into the optical, or is caused by an under estimation of the Zodiacal foreground. We report performance of the assembled and tested instrument as we prepare for a first sounding rocket flight in early 2009. CIBER is funded by the NASA/APRA sub-orbital program.

  17. Uncertain Portfolio Selection with Background Risk and Liquidity Constraint

    Directory of Open Access Journals (Sweden)

    Jia Zhai

    2017-01-01

    Full Text Available This paper discusses an uncertain portfolio selection problem with consideration of background risk and asset liquidity. In addition, the transaction costs are also considered. The security returns, background asset return, and asset liquidity are estimated by experienced experts instead of historical data. Regarding them as uncertain variables, a mean-risk model with background risk, liquidity, and transaction costs is proposed for portfolio selection and the crisp forms of the model are provided when security returns obey different uncertainty distributions. Moreover, for better understanding of the impact of background risk and liquidity on portfolio selection, some important theorems are proved. Finally, numerical experiments are presented to illustrate the modeling idea.

  18. Natural gas benefits

    International Nuclear Information System (INIS)

    1999-01-01

    The General Auditor in the Netherlands studied the natural gas policy in the Netherlands, as has been executed in the past decades, in the period 1997-1999. The purpose of the study is to inform the Dutch parliament on the planning and the backgrounds of the natural gas policy and on the policy risks with respect to the benefits for the Dutch State, taking into account the developments in the policy environment. The final conclusion is that the proposed liberalization of the national natural gas market will result in a considerable deprivation of income for the State in case the benefit policy is not adjusted. This report includes a reaction of the Dutch Minister of Economic Affairs and an afterword of the General Auditor. In the appendix an outline is given of the natural gas policy

  19. Understanding Translation

    DEFF Research Database (Denmark)

    Schjoldager, Anne Gram; Gottlieb, Henrik; Klitgård, Ida

    Understanding Translation is designed as a textbook for courses on the theory and practice of translation in general and of particular types of translation - such as interpreting, screen translation and literary translation. The aim of the book is to help you gain an in-depth understanding...... of the phenomenon of translation and to provide you with a conceptual framework for the analysis of various aspects of professional translation. Intended readers are students of translation and languages, but the book will also be relevant for others who are interested in the theory and practice of translation...... - translators, language teachers, translation users and literary, TV and film critics, for instance. Discussions focus on translation between Danish and English....

  20. Understanding Resilience

    Directory of Open Access Journals (Sweden)

    Gang eWu

    2013-02-01

    Full Text Available Resilience is the ability to adapt successfully in the face of stress and adversity. Stressful life events, trauma and chronic adversity can have a substantial impact on brain function and structure, and can result in the development of PTSD, depression and other psychiatric disorders. However, most individuals do not develop such illnesses after experiencing stressful life events, and are thus thought to be resilient. Resilience as successful adaptation relies on effective responses to environmental challenges and ultimate resistance to the deleterious effects of stress, therefore a greater understanding of the factors that promote such effects is of great relevance. This review focuses on recent findings regarding genetic, epigenetic, developmental, psychosocial and neurochemical factors that are considered essential contributors to the development of resilience. Neural circuits and pathways involved in mediating resilience are also discussed. The growing understanding of resilience factors will hopefully lead to the development of new pharmacological and psychological interventions for enhancing resilience and mitigating the untoward consequences.

  1. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  2. Understanding unemployment

    OpenAIRE

    Guillaume Rocheteau

    2006-01-01

    Modern economists have built models of the labor market, which isolate the market’s key drivers and describe the way these interact to produce particular levels of unemployment. One of the most popular models used by macroeconomists today is the search-matching model of equilibrium unemployment. We explain this model, and show how it can be applied to understand the way various policies, such as unemployment benefits, taxes, or technological changes, can affect the unemployment rate.

  3. Solid gas reaction phase diagram under high gas pressure

    International Nuclear Information System (INIS)

    Ishizaki, K.

    1992-01-01

    This paper reports that to evaluate which are the stable phases under high gas pressure conditions, a solid-gas reaction phase diagram under high gas pressure (HIP phase diagram) has been proposed by the author. The variables of the diagram are temperature, reactant gas partial pressure and total gas pressure. Up to the present time the diagrams have been constructed using isobaric conditions. In this work, the stable phases for a real HIP process were evaluated assuming an isochoric condition. To understand the effect of the total gas pressure on stability is of primary importance. Two possibilities were considered and evaluated, those are: the total gas pressure acts as an independent variable, or it only affects the fugacity values. The results of this work indicate that the total gas pressure acts as an independent variable, and in turn also affects the fugacity values

  4. Understanding Technology?

    Directory of Open Access Journals (Sweden)

    Erik Bendtsen

    2016-11-01

    Full Text Available We are facing radical changes in our ways of living in the nearest future. Not necessarily of our own choice, but because tchnological development is moving so fast, that it will have still greater impact on many aspects of our lives. We have seen the beginnings of that change within the latest 35 years or so, but according to newest research that change will speed up immensely in the nearest years to come. The impact of that change or these changes will affect our working life immensely as a consequence of automation. How these changes are brought about and which are their consequences in a broad sense is being attempted to be understood and guessed by researchers. No one knows for sure, but specific patterns are visible. This paper will not try to guess, what will come, but will rather try to understand the deepest ”nature” of technology in order to understand the driving factors in this development: the genesis of technology in a broad sense in order to contibute to the understanding of the basis for the expected development.

  5. Understanding Magnitudes to Understand Fractions

    Science.gov (United States)

    Gabriel, Florence

    2016-01-01

    Fractions are known to be difficult to learn and difficult to teach, yet they are vital for students to have access to further mathematical concepts. This article uses evidence to support teachers employing teaching methods that focus on the conceptual understanding of the magnitude of fractions.

  6. Testing Understanding and Understanding Testing.

    Science.gov (United States)

    Pedersen, Jean; Ross, Peter

    1985-01-01

    Provides examples in which graphs are used in the statements of problems or in their solutions as a means of testing understanding of mathematical concepts. Examples (appropriate for a beginning course in calculus and analytic geometry) include slopes of lines and curves, quadratic formula, properties of the definite integral, and others. (JN)

  7. Background radioactivity in environmental materials

    International Nuclear Information System (INIS)

    Maul, P.R.; O'Hara, J.P.

    1989-01-01

    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)

  8. 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 ...

  9. Backgrounds and characteristics of arsonists.

    Science.gov (United States)

    Labree, Wim; Nijman, Henk; van Marle, Hjalmar; Rassin, Eric

    2010-01-01

    The aim of this study was to gain more insight in the backgrounds and characteristics of arsonists. For this, the psychiatric, psychological, personal, and criminal backgrounds of all arsonists (n=25), sentenced to forced treatment in the maximum security forensic hospital "De Kijvelanden", were compared to the characteristics of a control group of patients (n=50), incarcerated at the same institution for other severe crimes. Apart from DSM-IV Axis I and Axis II disorders, family backgrounds, level of education, treatment history, intelligence (WAIS scores), and PCL-R scores were included in the comparisons. Furthermore, the apparent motives for the arson offences were explored. It was found that arsonists had more often received psychiatric treatment, prior to committing their index offence, and had a history of severe alcohol abuse more often in comparison to the controls. The arsonists turned out to be less likely to suffer from a major psychotic disorder. Both groups did not differ significantly on the other variables, among which the PCL-R total scores and factor scores. Exploratory analyses however, did suggest that arsonists may differentiate from non-arsonists on three items of the PCL-R, namely impulsivity (higher scores), superficial charm (lower scores), and juvenile delinquency (lower scores). Although the number of arsonists with a major psychotic disorder was relatively low (28%), delusional thinking of some form was judged to play a role in causing arson crimes in about half of the cases (52%).

  10. Understanding uncertainty

    CERN Document Server

    Lindley, Dennis V

    2013-01-01

    Praise for the First Edition ""...a reference for everyone who is interested in knowing and handling uncertainty.""-Journal of Applied Statistics The critically acclaimed First Edition of Understanding Uncertainty provided a study of uncertainty addressed to scholars in all fields, showing that uncertainty could be measured by probability, and that probability obeyed three basic rules that enabled uncertainty to be handled sensibly in everyday life. These ideas were extended to embrace the scientific method and to show how decisions, containing an uncertain element, could be rationally made.

  11. Method for mapping a natural gas leak

    Science.gov (United States)

    Reichardt, Thomas A [Livermore, CA; Luong, Amy Khai [Dublin, CA; Kulp, Thomas J [Livermore, CA; Devdas, Sanjay [Albany, CA

    2009-02-03

    A system is described that is suitable for use in determining the location of leaks of gases having a background concentration. The system is a point-wise backscatter absorption gas measurement system that measures absorption and distance to each point of an image. The absorption measurement provides an indication of the total amount of a gas of interest, and the distance provides an estimate of the background concentration of gas. The distance is measured from the time-of-flight of laser pulse that is generated along with the absorption measurement light. The measurements are formatted into an image of the presence of gas in excess of the background. Alternatively, an image of the scene is superimposed on the image of the gas to aid in locating leaks. By further modeling excess gas as a plume having a known concentration profile, the present system provides an estimate of the maximum concentration of the gas of interest.

  12. Understanding analysis

    CERN Document Server

    Abbott, Stephen

    2015-01-01

    This lively introductory text exposes the student to the rewards of a rigorous study of functions of a real variable. In each chapter, informal discussions of questions that give analysis its inherent fascination are followed by precise, but not overly formal, developments of the techniques needed to make sense of them. By focusing on the unifying themes of approximation and the resolution of paradoxes that arise in the transition from the finite to the infinite, the text turns what could be a daunting cascade of definitions and theorems into a coherent and engaging progression of ideas. Acutely aware of the need for rigor, the student is much better prepared to understand what constitutes a proper mathematical proof and how to write one. Fifteen years of classroom experience with the first edition of Understanding Analysis have solidified and refined the central narrative of the second edition. Roughly 150 new exercises join a selection of the best exercises from the first edition, and three more project-sty...

  13. Understanding ayurveda.

    Science.gov (United States)

    Gadgil, Vaidya Dilip

    2010-01-01

    Ayurveda needs to achieve its full potential both in India and globally. This requires imparting to its students full appreciation of Ayurveda's power and strength, particularly proper understanding of the advantages of applying it to treat chronic and acute diseases. To this end, we explain the necessity of learning Sanskrit as a medium of study, and the advantages of learning the Texts in the traditional way, rather than relying on translations with all the loss of meaning and precision, which that entails. We emphasize the use of Triskandhakosha as a means to fully understand Ayurveda fundamental concepts and technical terms, so that all their shades of meaning are fully understood, and all their usages given in different places in the texts. Only by such methods can full appreciation of Ayurvedic wisdom be achieved, and the full depth and power of its knowledge be applied. Only then will its true status among systems of medicine come to be appreciated, either in India or more widely in the world as a whole.

  14. Understanding Ayurveda

    Directory of Open Access Journals (Sweden)

    Vaidya Dilip Gadgil

    2010-01-01

    Full Text Available Ayurveda needs to achieve its full potential both in India and globally. This requires imparting to its students full appreciation of Ayurveda′s power and strength, particularly proper understanding of the advantages of applying it to treat chronic and acute diseases. To this end, we explain the necessity of learning Sanskrit as a medium of study, and the advantages of learning the Texts in the traditional way, rather than relying on translations with all the loss of meaning and precision, which that entails. We emphasize the use of Triskandhakosha as a means to fully understand Ayurveda fundamental concepts and technical terms, so that all their shades of meaning are fully understood, and all their usages given in different places in the texts. Only by such methods can full appreciation of Ayurvedic wisdom be achieved, and the full depth and power of its knowledge be applied. Only then will its true status among systems of medicine come to be appreciated, either in India or more widely in the world as a whole.

  15. Family Background and Educational Choices

    DEFF Research Database (Denmark)

    McIntosh, James; D. Munk, Martin

    enrollments, especially for females. Not only did the educational opportunities for individuals with disadvantaged backgrounds improve absolutely, but their relative position also improved. A similarly dramatic increase in attendance at university for the period 1985-2005 was found for these cohorts when......We examine the participation in secondary and tertiary education of five cohorts of Danish males and females who were aged twenty starting in 1982 and ending in 2002. We find that the large expansion of secondary education in this period was characterized by a phenomenal increase in gymnasium...

  16. Effects of background music on concentration of workers.

    Science.gov (United States)

    Huang, Rong-Hwa; Shih, Yi-Nuo

    2011-01-01

    Background music is a common element in daily living and the workplace. Determination of whether background music affects human work concentration is a relevant concern. Studies have found background music influences human behavior, and this study attempts to understand how background music and listener fondness for types of music affects worker concentration. This study analyzes how different types of background music--and how listeners' degree of preference for the background music--can affect listener concentration in attention testing through Randomized Controlled Trial (RCT). Data were collected from 89 workers. The participants ranged in age between 19 and 28 years old, with an average age of 24 years old. We conclude background music influenced listener attention. This influence has more to do with listener fondness for the music than with type of music. Compared to situations without background music, the likelihood of background music affecting test-taker attention performance is likely to increase with the degree to which the test-taker likes or dislikes the music. It is important not to select music that workers strongly like or dislike when making a selection of background music to avoid negatively affecting worker concentration.

  17. Understanding physics

    CERN Document Server

    Cassidy, David; Rutherford, James

    2002-01-01

    Understanding Physics provides a thorough grounding in contemporary physics while placing physics into its social and historical context Based in large part on the highly respected Project Physics Course developed by two of the authors, it also integrates the results of recent pedagogical research The text thus - teaches about the basic phenomena in the physical world and the concepts developed to explain them - shows that science is a rational human endeavor with a long and continuing tradition, involving many different cultures and people - develops facility in critical thinking, reasoned argumentation, evaluation of evidence, mathematical modeling, and ethical values The treatment emphasizes not only what we know but also how we know it, why we believe it, and what effects that knowledge has - Why do we believe the Earth and planets revolve around the Sun? - Why do we believe that matter is made of atoms? - How do relativity theory and quantum mechanics alter our conception of Nature and in what ways do th...

  18. Understanding users

    DEFF Research Database (Denmark)

    Johannsen, Carl Gustav Viggo

    2014-01-01

    Segmentation of users can help libraries in the process of understanding user similarities and differences. Segmentation can also form the basis for selecting segments of target users and for developing tailored services for specific target segments. Several approaches and techniques have been...... tested in library contexts and the aim of this article is to identify the main approaches and to discuss their perspectives, including their strenghts and weaknesses in, especially, public library contexts. The purpose is also to prsent and discuss the results of a recent - 2014 - Danish library user...... segmentation project using computer-generated clusters. Compared to traditional marketing texts, this article also tries to identify user segments or images or metaphors by the library profession itself....

  19. Association of Radon Background and Total Background Ionizing Radiation with Alzheimer's Disease Deaths in U.S. States.

    Science.gov (United States)

    Lehrer, Steven; Rheinstein, Peter H; Rosenzweig, Kenneth E

    2017-01-01

    Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

  20. Background radiation map of Thailand

    International Nuclear Information System (INIS)

    Angsuwathana, P.; Chotikanatis, P.

    1997-01-01

    The radioelement concentration in the natural environment as well as the radiation exposure to man in day-to-day life is now the most interesting topic. The natural radiation is frequently referred as a standard for comparing additional sources of man-made radiation such as atomic weapon fallout, nuclear power generation, radioactive waste disposal, etc. The Department of Mineral Resources commenced a five-year project of nationwide airborne geophysical survey by awarding to Kenting Earth Sciences International Limited in 1984. The original purpose of survey was to support mineral exploration and geological mapping. Subsequently, the data quantity has been proved to be suitable for natural radiation information. In 1993 the Department of Mineral Resources, with the assistance of IAEA, published a Background Radiation Map of Thailand at the scale of 1:1,000,000 from the existing airborne radiometric digital data. The production of Background Radiation Map of Thailand is the result of data compilation and correction procedure developed over the Canadian Shield. This end product will be used as a base map in environmental application not only for Thailand but also Southeast Asia region. (author)

  1. [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.

  2. Optical polarization: background and camouflage

    Science.gov (United States)

    Škerlind, Christina; Hallberg, Tomas; Eriksson, Johan; Kariis, Hans; Bergström, David

    2017-10-01

    Polarimetric imaging sensors in the electro-optical region, already military and commercially available in both the visual and infrared, show enhanced capabilities for advanced target detection and recognition. The capabilities arise due to the ability to discriminate between man-made and natural background surfaces using the polarization information of light. In the development of materials for signature management in the visible and infrared wavelength regions, different criteria need to be met to fulfil the requirements for a good camouflage against modern sensors. In conventional camouflage design, the aimed design of the surface properties of an object is to spectrally match or adapt it to a background and thereby minimizing the contrast given by a specific threat sensor. Examples will be shown from measurements of some relevant materials and how they in different ways affect the polarimetric signature. Dimensioning properties relevant in an optical camouflage from a polarimetric perspective, such as degree of polarization, the viewing or incident angle, and amount of diffuse reflection, mainly in the infrared region, will be discussed.

  3. The Cosmic Microwave Background Anisotropy

    Science.gov (United States)

    Bennett, C. L.

    1994-12-01

    The properties of the cosmic microwave background radiation provide unique constraints on the history and evolution of the universe. The first detection of anisotropy of the microwave radiation was reported by the COBE Team in 1992, based on the first year of flight data. The latest analyses of the first two years of COBE data are reviewed in this talk, including the amplitude of the microwave anisotropy as a function of angular scale and the statistical nature of the fluctuations. The two-year results are generally consistent with the earlier first year results, but the additional data allow for a better determination of the key cosmological parameters. In this talk the COBE results are compared with other observational anisotropy results and directions for future cosmic microwave anisotropy observations will be discussed. The National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) is responsible for the design, development, and operation of the Cosmic Background Explorer (COBE). Scientific guidance is provided by the COBE Science Working Group.

  4. Correlation between galactic HI and the cosmic microwave background

    International Nuclear Information System (INIS)

    Land, Kate; Slosar, Anze

    2007-01-01

    We revisit the issue of a correlation between the atomic hydrogen gas in our local galaxy and the cosmic microwave background, a detection of which has been claimed in some literature. We cross correlate the 21-cm emission of galactic atomic hydrogen as traced by the Leiden/Argentine/Bonn Galactic Hi survey with the 3-year cosmic microwave background data from the Wilkinson microwave anisotropy probe. We consider a number of angular scales, masks, and Hi velocity slices and find no statistically significant correlation

  5. Gas accretion onto galaxies

    CERN Document Server

    Davé, Romeel

    2017-01-01

    This edited volume presents the current state of gas accretion studies from both observational and theoretical perspectives, and charts our progress towards answering the fundamental yet elusive question of how galaxies get their gas. Understanding how galaxies form and evolve has been a central focus in astronomy for over a century. These studies have accelerated in the new millennium, driven by two key advances: the establishment of a firm concordance cosmological model that provides the backbone on which galaxies form and grow, and the recognition that galaxies grow not in isolation but within a “cosmic ecosystem” that includes the vast reservoir of gas filling intergalactic space. This latter aspect in which galaxies continually exchange matter with the intergalactic medium via inflows and outflows has been dubbed the “baryon cycle”. The topic of this book is directly related to the baryon cycle, in particular its least well constrained aspect, namely gas accretion. Accretion is a rare area of ast...

  6. Gas insulated substations

    CERN Document Server

    2014-01-01

    This book provides an overview on the particular development steps of gas insulated high-voltage switchgear, and is based on the information given with the editor's tutorial. The theory is kept low only as much as it is needed to understand gas insulated technology, with the main focus of the book being on delivering practical application knowledge. It discusses some introductory and advanced aspects in the meaning of applications. The start of the book presents the theory of Gas Insulated Technology, and outlines reliability, design, safety, grounding and bonding, and factors for choosing GIS. The third chapter presents the technology, covering the following in detail: manufacturing, specification, instrument transformers, Gas Insulated Bus, and the assembly process. Next, the book goes into control and monitoring, which covers local control cabinet, bay controller, control schemes, and digital communication. Testing is explained in the middle of the book before installation and energization. Importantly, ...

  7. Effect of background music on auditory-verbal memory performance

    OpenAIRE

    Sona Matloubi; Ali Mohammadzadeh; Zahra Jafari; Alireza Akbarzade Baghban

    2014-01-01

    Background and Aim: Music exists in all cultures; many scientists are seeking to understand how music effects cognitive development such as comprehension, memory, and reading skills. More recently, a considerable number of neuroscience studies on music have been developed. This study aimed to investigate the effects of null and positive background music in comparison with silence on auditory-verbal memory performance.Methods: Forty young adults (male and female) with normal hearing, aged betw...

  8. Muon-induced backgrounds in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, E.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J. W.; Bellini, F.; Bloxham, T.; Brofferio, C.; Bryant, A.; Bucci, C.; Canonica, L.; Capelli, S.; Carbone, L.; Carrettoni, M.; Clemenza, M.; Cremonesi, O.; Creswick, R. J.; Domizio, S. Di; Dolinski, M. J.; Ejzak, L.; Faccini, R.; Farach, H. A.; Ferri, E.; Ferroni, F.; Fiorini, E.; Foggetta, L.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Guardincerri, E.; Gutierrez, T. D.; Haller, E. E.; Kadel, R.; Kazkaz, K.; Kraft, S.; Kogler, L.; Kolomensky, Yu. G.; Maiano, C.; Maruyama, R. H.; Martinez, C.; Martinez, M.; Mizouni, L.; Morganti, S.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; Orio, F.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Risegari, L.; Rosenfeld, C.; Rusconi, C.; Salvioni, C.; Sangiorgio, S.; Schaeffer, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Tomei, C.; Ventura, G.; Vignati, M.

    2010-04-15

    To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.

  9. 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...

  10. Low background aspects of GERDA

    International Nuclear Information System (INIS)

    Simgen, Hardy

    2011-01-01

    The GERDA experiment operates bare Germanium diodes enriched in 76 Ge 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 222 Rn. The main source of 222 Rn 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 228 Th.

  11. The cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1980-01-01

    The history is described of the discovery of microwave radiation of the cosmic background using the 20-foot horn antenna at the Bell Laboratories back in 1965. Ruby masers with travelling wave were used, featuring the lowest noise in the world. The measurement proceeded on 7 cm. In measuring microwave radiation from the regions outside the Milky Way continuous noise was discovered whose temperature exceeded the calculated contributions of the individual detection system elements by 3 K. A comparison with the theory showed that relict radiation from the Big Bang period was the source of the noise. The discovery was verified by measurements on the 20.1 cm wavelength and by other authors' measurements on 0.5 mm to 74 cm, and by optical measurements of the interstellar molecule spectrum. (Ha)

  12. Polarization of Cosmic Microwave Background

    International Nuclear Information System (INIS)

    Buzzelli, A; Cabella, P; De Gasperis, G; Vittorio, N

    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. (paper)

  13. Insights into the background of autonomic medicine.

    Science.gov (United States)

    Laranjo, Sérgio; Geraldes, Vera; Oliveira, Mário; Rocha, Isabel

    2017-10-01

    Knowledge of the physiology underlying the autonomic nervous system is pivotal for understanding autonomic dysfunction in clinical practice. Autonomic dysfunction may result from primary modifications of the autonomic nervous system or be secondary to a wide range of diseases that cause severe morbidity and mortality. Together with a detailed history and physical examination, laboratory assessment of autonomic function is essential for the analysis of various clinical conditions and the establishment of effective, personalized and precise therapeutic schemes. This review summarizes the main aspects of autonomic medicine that constitute the background of cardiovascular autonomic dysfunction. Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Natural radiation background in the ancient city of Palmyra

    International Nuclear Information System (INIS)

    Shweikani, R.; Al-Masri, M.S.; Hushari, M.; Raja, G.; Aissa, M.; Al-Hent, R.

    2012-01-01

    Natural radiation background has been determined for the Ancient City of Palmyra and its surrounding areas. Car-borne gamma spectrometry, indoor radon gas concentration and natural radionuclides levels in environmental samples (soil, water and plants) have been determined. Two types of dwelling were involved in this study, one with cancer cases, and the others without. The results showed that indoor radon gas concentrations and radiation exposure rates are within reported mean background levels in Syria (45 Bq m −3 and less than 0.1 μSv h −1 , respectively); no differences were noticed between the dwelling groups. In addition, the results did not indicate any relation between recorded cancers and measured natural radioactivity.

  15. Background in xenon filled X-ray detectors

    International Nuclear Information System (INIS)

    Feroci, M.; Costa, E.; Dwyer, J.; Ford, E.; Kaaret, P.; Rapisarda, M.; Soffitta, P.

    1995-01-01

    Xenon based gas mixtures have been often used in proportional counters for X-ray astronomy in order to achieve a good efficiency in the medium/high X-ray energy range. Proportional counters flown on past missions (i.e. HEAO1 and EXOSAT) filled with Xe-based mixtures have shown a higher residual background (after that all the rejection techniques have been applied) with respect to Ar-based ones, operating in the same energy band and in the same radiation environment. We show, by means of Monte Carlo simulations, analytical computations and laboratory measurements, that such difference can be mostly understood in terms of higher internal background production and lower pulse discrimination efficiency in Xe-based gas filling, with respect to Ar-based ones. (orig.)

  16. Logistics background study: underground mining

    Energy Technology Data Exchange (ETDEWEB)

    Hanslovan, J. J.; Visovsky, R. G.

    1982-02-01

    Logistical functions that are normally associated with US underground coal mining are investigated and analyzed. These functions imply all activities and services that support the producing sections of the mine. The report provides a better understanding of how these functions impact coal production in terms of time, cost, and safety. Major underground logistics activities are analyzed and include: transportation and personnel, supplies and equipment; transportation of coal and rock; electrical distribution and communications systems; water handling; hydraulics; and ventilation systems. Recommended areas for future research are identified and prioritized.

  17. High Octane Fuel: Terminal Backgrounder

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, Kristi [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-11

    The Bioenergy Technologies Office of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy sponsored a scoping study to assess the potential of ethanol-based high octane fuel (HOF) to reduce energy consumption and greenhouse gas emissions. When the HOF blend is made with 25%-40% ethanol by volume, this energy efficiency improvement is potentially sufficient to offset the reduced vehicle range often associated with the decreased volumetric energy density of ethanol. The purpose of this study is to assess the ability of the fuel supply chain to accommodate more ethanol at fuel terminals. Fuel terminals are midstream in the transportation fuel supply chain and serve to store and distribute fuels to end users. While there are no technical issues to storing more ethanol at fuel terminals, there are several factors that could impact the ability to deploy more ethanol. The most significant of these issues include the availability of land to add more infrastructure and accommodate more truck traffic for ethanol deliveries as well as a lengthy permitting process to erect more tanks.

  18. Primary and Secondary Anisotropies of Cosmic Microwave Background

    Science.gov (United States)

    Seljak, Uros

    2002-01-01

    The three main topics we proposed to do are linear calculations (continuing development of CMBFAST), nonlinear calculations of gas physics relevant to Cosmic Microwave Background (CMB) (Sunyaev-Zeldovich effect, etc.) and nonlinear effects on CMB due to dark matter (gravitational lensing, etc.). We describe each of these topics, as well as additional topics PI and his group worked on that are related to the topics in the proposal.

  19. Muon-induced backgrounds in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, E; Arnaboldi, C; Avignone, F T; Balata, M; Bandac, I; Barucci, M; Beeman, J W; Bellini, F; Bloxham, T; Brofferio, C; Bryant, A; Bucci, C; Canonica, L; Capelli, S; Carbone, L; Carrettoni, M; Clemenza, M; Cremonesi, O; Creswick, R J; Domizio, S D; Dolinski, M J; Ejzak, L; Faccini, R; Farach, H A; Ferri, E; Ferroni, F; Firoini, E; Foggetta, L; Giachero, A; Gironi, L; Giuliani, A; Gorla, P; Guardincerri, E; Gutierrez, T D; Haller, E E; Kadel, R; Kazkaz, K; Kraft, S; Kogler, L; Kolomensky, Y G; Maiano, C; Maruyama, R H; Martinez, C; Martinez, M; Mizouni, L; Morganti, S; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; Orio, F; Pallavicini, M; Palmieri, V; Pattavina, L; Pavan, M; Pedretti, M; Pessina, G; Pirro, S; Previtali, E; Risegari, L; Rosenfeld, C; Rusconi, C; Salvioni, C; Sangiorgio, S; Schaeffer, D; Scielzo, N D; Sisti, M; Smith, A R; Tomei, C; Ventura, G; Vignati, M

    2009-11-16

    To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO site and operated during 3 months of the CUORICINO experiment. From these measurements, an upper limit of 0.0021 counts/keV {center_dot} kg {center_dot} yr (95% C.L.) was obtained on the cosmic ray induced background in the neutrinoless double beta decay region of interest. The measurements were compared to Geant4 simulations, which are similar to those that will be used to estimate the backgrounds in CUORE.

  20. The Interaction of Local Context and Cultural Background

    DEFF Research Database (Denmark)

    Nielsen, Rikke Skovgaard; Holmqvist, Emma; Dhalman, Hanna

    2015-01-01

    Immigrants' housing position is often explained by (lack of) resources or differences in cultural backgrounds. Recent studies have included the importance of local context. The aim of this paper is to examine Somalis' perceptions of their possibilities in four Nordic capitals' housing markets...... and sometimes conflict with each other, but that the negotiation between cultural background and local context was individual. The conclusion is that local context and cultural background are important factors for understanding differences between Somalis on different housing markets, thus emphasising...

  1. The Importance of Background Culture Knowledge in Reading

    Institute of Scientific and Technical Information of China (English)

    王蓁

    2012-01-01

    As achieving cross-culture communication is the final aim of learning English,it turns out to be inefficient to attach more importance on the ability of listening,speaking,reading,writing and knowledge system.Background culture knowledge is supposed to be an important way to reach the aim of language teaching,and help readers understand articles.Considering the effects of background culture knowledge and its importance,this article will do a research on it and try to help both readers and teachers aware of the importance of background culture knowledge and take note of it.

  2. GAS BEARING

    Science.gov (United States)

    Skarstrom, C.W.

    1960-09-01

    A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

  3. Requirements for gas quality and gas appliances

    NARCIS (Netherlands)

    Levinsky, Howard; Gersen, Sander; Kiewiet, Bert

    2015-01-01

    Introduction The gas transmission network in the Netherlands transports two different qualities of gas, low-calorific gas known as G-gas or L-gas and, high calorific gas (H-gas). These two gas qualities are transported in separate networks, and are connected by means of five blending and conversion

  4. Gas magnetometer

    Science.gov (United States)

    Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

    2016-05-03

    Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.

  5. Gas separating

    Science.gov (United States)

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  6. Plenoptic background oriented schlieren imaging

    International Nuclear Information System (INIS)

    Klemkowsky, Jenna N; Fahringer, Timothy W; Clifford, Christopher J; Thurow, Brian S; Bathel, Brett F

    2017-01-01

    The combination of the background oriented schlieren (BOS) technique with the unique imaging capabilities of a plenoptic camera, termed plenoptic BOS, is introduced as a new addition to the family of schlieren techniques. Compared to conventional single camera BOS, plenoptic BOS is capable of sampling multiple lines-of-sight simultaneously. Displacements from each line-of-sight are collectively used to build a four-dimensional displacement field, which is a vector function structured similarly to the original light field captured in a raw plenoptic image. The displacement field is used to render focused BOS images, which qualitatively are narrow depth of field slices of the density gradient field. Unlike focused schlieren methods that require manually changing the focal plane during data collection, plenoptic BOS synthetically changes the focal plane position during post-processing, such that all focal planes are captured in a single snapshot. Through two different experiments, this work demonstrates that plenoptic BOS is capable of isolating narrow depth of field features, qualitatively inferring depth, and quantitatively estimating the location of disturbances in 3D space. Such results motivate future work to transition this single-camera technique towards quantitative reconstructions of 3D density fields. (paper)

  7. Concerning background from calorimeter ports

    International Nuclear Information System (INIS)

    Digiacomo, N.J.

    1985-01-01

    Any detector system viewing a port or slit in a calorimeter wall will see, in addition to the primary particles of interest, a background of charged and neutral particles and photons generated by scattering from the port walls and by leakage from incompletely contained primary particle showers in the calorimeter near the port. The signal to noise ratio attainable outside the port is a complex function of the primary source spectrum, the calorimeter and port design and, of course, the nature and acceptance of the detector system that views the port. Rather than making general statements about the overall suitability (or lack thereof) of calorimeter ports, we offer here a specific example based on the external spectrometer and slit of the NA34 experiment. This combination of slit and spectrometer is designed for fixed-target work, so that the primary particle momentum spectrum contains higher momentum particles than expected in a heavy ion colliding beam environment. The results are, nevertheless, quite relevant for the collider case

  8. Natural background radiation in Jordan

    International Nuclear Information System (INIS)

    Daoud, M.N.S.

    1997-01-01

    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)

  9. Natural background radiation in Jordan

    Energy Technology Data Exchange (ETDEWEB)

    Daoud, M N.S. [National Resources Authority, Ministry of Energy and Mineral Resources, Amman (Jordan)

    1997-11-01

    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 ({mu}R/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). 8 refs, 10 figs, 7 tabs.

  10. Gas Research Institute wetland research program

    International Nuclear Information System (INIS)

    Wilkey, P.L.; Zimmerman, R.E.; Isaacson, H.R.

    1992-01-01

    As part of three ongoing research projects, the Gas Research Institute (GRI) is studying the natural gas industry's impacts on wetlands and how to manage operations so that impacts can be minimized or eliminated. The objective of the first project is to gain a better understanding of the causes and processes of wetland loss in the Louisiana deltaic plain and what role gas pipeline canals play in wetland loss. On the basis of information gathered from the first projects, management and mitigation implications for pipeline construction and maintenance will be evaluated. The objective of the second project is to assess the floral and faunal communities on existing rights-of-way (ROWs) that pass through numerous types of wetlands across the United States. The emphasis of the project is on pipelines that were installed within the past five years. The objective of the third project is to evaluate the administrative, jurisdictional, technical, and economic issues of wetland mitigation banking. This paper discusses these projects, their backgrounds, some of the results to date, and the deliverables

  11. Natural gas massification plan in Colombia with the National Oil Framework

    International Nuclear Information System (INIS)

    Arenas, I.

    1993-01-01

    The Colombian natural gas industry is described. The Colombian natural gas plan is discussed under the following topics: background of natural gas in Colombia, natural gas reserves, gas plan objectives, methodology, marketing studies, transportation and investment strategy, and economic evaluation. The present natural gas institutional framework is described. The production system structure, transportation, and distribution are also discussed

  12. High potential recovery -- Gas repressurization

    Energy Technology Data Exchange (ETDEWEB)

    Madden, M.P.

    1998-05-01

    The objective of this project was to demonstrate that small independent oil producers can use existing gas injection technologies, scaled to their operations, to repressurize petroleum reservoirs and increase their economic oil production. This report gives background information for gas repressurization technologies, the results of workshops held to inform small independent producers about gas repressurization, and the results of four gas repressurization field demonstration projects. Much of the material in this report is based on annual reports (BDM-Oklahoma 1995, BDM-Oklahoma 1996, BDM-Oklahoma 1997), a report describing the results of the workshops (Olsen 1995), and the four final reports for the field demonstration projects which are reproduced in the Appendix. This project was designed to demonstrate that repressurization of reservoirs with gas (natural gas, enriched gas, nitrogen, flue gas, or air) can be used by small independent operators in selected reservoirs to increase production and/or decrease premature abandonment of the resource. The project excluded carbon dioxide because of other DOE-sponsored projects that address carbon dioxide processes directly. Two of the demonstration projects, one using flue gas and the other involving natural gas from a deeper coal zone, were both technical and economic successes. The two major lessons learned from the projects are the importance of (1) adequate infrastructure (piping, wells, compressors, etc.) and (2) adequate planning including testing compatibility between injected gases and fluids, and reservoir gases, fluids, and rocks.

  13. Redistribution of energetic particles by background turbulence

    International Nuclear Information System (INIS)

    Hauff, T.; Jenko, F.

    2007-01-01

    The quest to understand the turbulent transport of particles, momentum and energy in magnetized plasmas remains a key challenge in fusion research. A basic issue being .still relatively poorly understood is the turbulent ExB advection of charged test particles with large gyroradii. Especially the interaction of alpha particles or impurities with the background turbulence is of great interest. In order to understand the dependence of the particle diffusivity on the interaction mechanisms between FLR effects and the special structure of a certain type of turbulence, direct numerical simulations are done in artificially created two dimensional turbulent electrostatic fields, assuming a constant magnetic field. Finite gyroradius effects are introduced using the gyrokinetic approximation which means that the gyrating particle is simply replaced by a charged ring. Starting from an idealized isotropic potential with Gaussian autocorrelation function, numerous test particle simulations are done varying both the gyroradius and the Kubo number of the potential. It is found that for Kubo numbers larger than about unity, the particle diffusivity is almost independent of the gyroradius as long as the latter does not exceed the correlation length of the electrostatic potential, whereas for small Kubo numbers the diffusivity is monotonically reduced. The underlying physical mechanisms of this behavior are identified and an analytic approach is developed which favorably agrees with the simulation results. The investigations are extended by introducing anisotropic structures like streamers and zonal flows into the artificial potential, leading to quantitative modulations of the gyroradius dependence of the diffusion coefficient. Analytic models are used to explain these various effects. After having developed a general overview on the behavior in simplified artificial potentials, test particle simulations in realistic turbulence created by the gyrokinetic turbulence code GENE are

  14. Scientific background of the project

    International Nuclear Information System (INIS)

    Christofidis, I.

    1997-01-01

    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

  15. Manure gas

    Energy Technology Data Exchange (ETDEWEB)

    Carre, I

    1947-05-01

    A short description of the process is given, with gas yields from various feedstocks, and the composition of the gas. Short descriptions of several batch digester designs are given: Algerian, Salubra, Betur, Baudot-Hardoll and Ofta, and Somagaz. The utilization and the economics of the process are discussed. Two diagrams of Ducellier and Isman designs are included.

  16. Hydrodynamic Simulation of the Cosmological X-Ray Background

    Science.gov (United States)

    Croft, Rupert A. C.; Di Matteo, Tiziana; Davé, Romeel; Hernquist, Lars; Katz, Neal; Fardal, Mark A.; Weinberg, David H.

    2001-08-01

    We use a hydrodynamic simulation of an inflationary cold dark matter model with a cosmological constant to predict properties of the extragalactic X-ray background (XRB). We focus on emission from the intergalactic medium (IGM), with particular attention to diffuse emission from warm-hot gas that lies in relatively smooth filamentary structures between galaxies and galaxy clusters. We also include X-rays from point sources associated with galaxies in the simulation, and we make maps of the angular distribution of the emission. Although much of the X-ray luminous gas has a filamentary structure, the filaments are not evident in the simulated maps because of projection effects. In the soft (0.5-2 keV) band, our calculated mean intensity of radiation from intergalactic and cluster gas is 2.3×10-12 ergs-1 cm-2 deg-2, 35% of the total softband emission. This intensity is compatible at the ~1 σ level with estimates of the unresolved soft background intensity from deep ROSAT and Chandra measurements. Only 4% of the hard (2-10 keV) emission is associated with intergalactic gas. Relative to active galactic nuclei flux, the IGM component of the XRB peaks at a lower redshift (median z~0.45) and spans a narrower redshift range, so its clustering makes an important contribution to the angular correlation function of the total emission. The clustering on the scales accessible to our simulation (0.1‧-10') is significant, with an amplitude roughly consistent with an extrapolation of recent ROSAT results to small scales. A cross-correlation analysis of the XRB against nearby galaxies taken from a simulated redshift survey also yields a strong signal from the IGM. Our conclusions about the soft background intensity differ from those of some recent papers that have argued that the expected emission from gas in galaxy, group, and cluster halos would exceed the observed background unless much of the gas is expelled by supernova feedback. We obtain reasonable compatibility with

  17. 49 CFR 172.416 - POISON GAS label.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false POISON GAS label. 172.416 Section 172.416... SECURITY PLANS Labeling § 172.416 POISON GAS label. (a) Except for size and color, the POISON GAS label... POISON GAS label and the symbol must be white. The background of the upper diamond must be black and the...

  18. 49 CFR 172.540 - POISON GAS placard.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false POISON GAS placard. 172.540 Section 172.540... SECURITY PLANS Placarding § 172.540 POISON GAS placard. (a) Except for size and color, the POISON GAS... the POISON GAS placard and the symbol must be white. The background of the upper diamond must be black...

  19. Landfill gas

    International Nuclear Information System (INIS)

    Hartnell, Gaynor

    2000-01-01

    Following the UK Government's initiative for stimulating renewable energy through the Non-Fossil Fuel Obligation (NFFO), the UK landfill gas industry has more than trebled in size in just 4 years. As a result, UK companies are now in a strong position to offer their skills and services overseas. Ireland, Greece and Spain also resort heavily to disposal to landfill. Particularly rapid growth of the landfill gas market is expected in the OECD-Pacific and NAFTA areas. The article explains that landfill gas is a methane-rich mixture produced by anaerobic decomposition of organic wastes in landfills: under optimum conditions, up to 500 cubic meters of gas can be obtained from 1 tonne of biodegradable waste. Data on the number and capacity of sites in the UK are given. The Landfill Gas Association runs courses to counteract the skills shortage in the UK, and tailored courses for overseas visitors are planned

  20. US production of natural gas from tight reservoirs

    International Nuclear Information System (INIS)

    1993-01-01

    For the purposes of this report, tight gas reservoirs are defined as those that meet the Federal Energy Regulatory Commission's (FERC) definition of tight. They are generally characterized by an average reservoir rock permeability to gas of 0.1 millidarcy or less and, absent artificial stimulation of production, by production rates that do not exceed 5 barrels of oil per day and certain specified daily volumes of gas which increase with the depth of the reservoir. All of the statistics presented in this report pertain to wells that have been classified, from 1978 through 1991, as tight according to the FERC; i.e., they are ''legally tight'' reservoirs. Additional production from ''geologically tight'' reservoirs that have not been classified tight according to the FERC rules has been excluded. This category includes all producing wells drilled into legally designated tight gas reservoirs prior to 1978 and all producing wells drilled into physically tight gas reservoirs that have not been designated legally tight. Therefore, all gas production referenced herein is eligible for the Section 29 tax credit. Although the qualification period for the credit expired at the end of 1992, wells that were spudded (began to be drilled) between 1978 and May 1988, and from November 5, 1990, through year end 1992, are eligible for the tax credit for a subsequent period of 10 years. This report updates the EIA's tight gas production information through 1991 and considers further the history and effect on tight gas production of the Federal Government's regulatory and tax policy actions. It also provides some high points of the geologic background needed to understand the nature and location of low-permeability reservoirs

  1. Hot Gas Halos in Galaxies

    Science.gov (United States)

    Mulchaey, John

    Most galaxy formation models predict that massive low-redshift disk galaxies are embedded in extended hot halos of externally accreted gas. Such gas appears necessary to maintain ongoing star formation in isolated spirals like the Milky Way. To explain the large population of red galaxies in rich groups and clusters, most galaxy evolution models assume that these hot gas halos are stripped completely when a galaxy enters a denser environment. This simple model has been remarkably successful at reproducing many observed properties of galaxies. Although theoretical arguments suggest hot gas halos are an important component in galaxies, we know very little about this gas from an observational standpoint. In fact, previous observations have failed to detect soft X-ray emission from such halos in disk galaxies. Furthermore, the assumption that hot gas halos are stripped completely when a galaxy enters a group or cluster has not been verified. We propose to combine proprietary and archival XMM-Newton observations of galaxies in the field, groups and clusters to study how hot gas halos are impacted by environment. Our proposed program has three components: 1) The deepest search to date for a hot gas halo in a quiescent spiral galaxy. A detection will confirm a basic tenet of disk galaxy formation models, whereas a non-detection will seriously challenge these models and impose new constraints on the growth mode and feedback history of disk galaxies. 2) A detailed study of the hot gas halos properties of field early-type galaxies. As environmental processes such as stripping are not expected to be important in the field, a study of hot gas halos in this environment will allow us to better understand how feedback and other internal processes impact hot gas halos. 3) A study of hot gas halos in the outskirts of groups and clusters. By comparing observations with our suite of simulations we can begin to understand what role the stripping of hot gas halos plays in galaxy

  2. Spectroscopy, Understanding the Atom Series.

    Science.gov (United States)

    Hellman, Hal

    This booklet is one of the "Understanding the Atom" Series. The science of spectroscopy is presented by a number of topics dealing with (1) the uses of spectroscopy, (2) its origin and background, (3) the basic optical systems of spectroscopes, spectrometers, and spectrophotometers, (4) the characteristics of wave motion, (5) the…

  3. The "efficacy-effectiveness gap" : Historical background and current conceptualization

    NARCIS (Netherlands)

    Nordon, Clementine; Karcher, Helene; Groenwold, Rolf H H; Ankarfeldt, Mikkel Zöllner; Pichler, Franz; Chevrou-Severac, Helene; Rossignol, Michel; Abbe, Adeline; Abenhaim, Lucien

    Background The concept of the "efficacy-effectiveness gap" (EEG) has started to challenge confidence in decisions made for drugs when based on randomized controlled trials alone. Launched by the Innovative Medicines Initiative, the GetReal project aims to improve understanding of how to reconcile

  4. Drill string gas data

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, E.R.

    1998-05-12

    Data and supporting documentation were compiled and analyzed for 26 cases of gas grab samples taken during waste-tank core sampling activities between September 1, 1995 and December 31, 1997. These cases were tested against specific criteria to reduce uncertainties associated with in-tank sampling location and conditions. Of the 26 possible cases, 16 qualified as drill-string grab samples most likely to represent recently released waste gases. The data from these 16 ``confirmed`` cases were adjusted to remove non-waste gas contributions from core-sampling activities (argon or nitrogen purge), the atmospheric background, and laboratory sampler preparation (helium). The procedure for subtracting atmospheric, laboratory, and argon purge gases was unambiguous. No reliable method for determining the exact amount of nitrogen purge gas was established. Thus, the final set of ``Adjusted`` drill string gas data for the 6 nitrogen-purged cases had a greater degree of uncertainty than the final results for the 10 argon-purged cases. Including the appropriate amounts of uncertainty, this final set of data was added to the set of high-quality results from the Retained Gas Sampler (RGS), and good agreement was found for the N{sub 2}, H{sub 2}, and N{sub 2}O mole fractions sampled from common tanks. These results indicate that under favorable sampling conditions, Drill-String (DS) grab samples can provide reasonably accurate information about the dominant species of released gas. One conclusion from this set of total gas data is that the distribution of the H{sub 2} mole fractions is bimodal in shape, with an upper bound of 78%.

  5. Flammable gas project topical report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, G.D.

    1997-01-29

    The flammable gas safety issue was recognized in 1990 with the declaration of an unreviewed safety question (USQ) by the U. S. Department of Energy as a result of the behavior of the Hanford Site high-level waste tank 241-SY-101. This tank exhibited episodic releases of flammable gas that on a couple of occasions exceeded the lower flammability limit of hydrogen in air. Over the past six years there has been a considerable amount of knowledge gained about the chemical and physical processes that govern the behavior of tank 241-SY-1 01 and other tanks associated with the flammable gas safety issue. This report was prepared to provide an overview of that knowledge and to provide a description of the key information still needed to resolve the issue. Items covered by this report include summaries of the understanding of gas generation, retention and release mechanisms, the composition and flammability behavior of the gas mixture, the amounts of stored gas, and estimated gas release fractions for spontaneous releases. `Me report also discusses methods being developed for evaluating the 177 tanks at the Hanford Site and the problems associated with these methods. Means for measuring the gases emitted from the waste are described along with laboratory experiments designed to gain more information regarding rates of generation, species of gases emitted and modes of gas storage and release. Finally, the process for closing the USQ is outlined as are the information requirements to understand and resolve the flammable gas issue.

  6. Distortion of plasma diagnostics by an ambient gas

    International Nuclear Information System (INIS)

    Pearlman, J.S.; Matzen, M.K.

    1978-03-01

    The effect of vacuum chamber background gas on the ion measurements of a laser-produced, expanding plasma is studied over a wide range of background gas pressures. Experimental measurements are compared with calculations from a coupled rate equation-hydrodynamics code. The code is then used for a parametric study of the effect of background gas pressure on plasma diagnostic measurements. Charge exchange is found to be an important process in our diagnostics above vacuum chamber pressures of 10 -5 Torr

  7. Investigation of radioactivity-induced backgrounds in EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Albert, J. B.; Auty, D. J.; Barbeau, P. S.; Beck, D.; Belov, V.; Benitez-Medina, C.; 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, C. G.; Davis, J.; Delaquis, S.; Der Mesrobian-Kabakian, A.; DeVoe, R.; Didberidze, T.; Dolgolenko, A.; Dolinski, M. J.; Dunford, M.; Fairbank, W.; Farine, J.; Feldmeier, W.; Fierlinger, P.; Fudenberg, D.; Giroux, G.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Herrin, S.; Hughes, M.; Jewell, M. J.; Jiang, X. S.; Johnson, A.; Johnson, T. N.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Killick, R.; Koffas, T.; Kravitz, S.; Kuchenkov, A.; Kumar, K. S.; Leonard, D. S.; Licciardi, C.; Lin, Y. H.; Ling, J.; MacLellan, R.; Marino, M. G.; Mong, B.; Moore, D.; Nelson, R.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Prescott, C. Y.; Rivas, A.; 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.

    2015-07-15

    The search for neutrinoless double-beta decay ( 0 ν β β ) requires extremely low background and a good understanding of their sources and their influence on the rate in the region of parameter space relevant to the 0 ν β β signal. We report on studies of various β and γ backgrounds in the liquid-xenon-based EXO- 200 0 ν β β experiment. With this work we try to better understand the location and strength of specific background sources and compare the conclusions to radioassay results taken before and during detector construction. Finally, we discuss the implications of these studies for EXO-200 as well as for the next-generation, tonne-scale nEXO detector.

  8. Treatment of Gas

    Science.gov (United States)

    ... Funding IFFGD Symposium reports Industry Council Contact Us Treatment of Gas You are here: Home Symptoms & Causes Intestinal Gas ... Controlling Intestinal Gas Foods That May Cause Gas Treatment of Gas Tips on Controlling Gas Adapted from IFFGD Publication # ...

  9. Asian gas

    International Nuclear Information System (INIS)

    Masuda, T.

    1990-01-01

    This paper reports on natural gas which now appears ready to take a leading role on the world energy stage. Demand for natural gas, and specifically LNG, will be strong throughout the world, particularly in Asia. Indonesia and Malaysia will become much more dependent on natural gas in the Asian market. In Thailand, where remarkable economic growth has been fueled by imported oil and domestically produced natural gas, LNG may soon have to be imported from neighboring countries. The author sees Thailand's imports of natural gas increasing from 1.5 to 4.5 million tons annually. Similarly, Korea's imports of LNG will rise from 2 to 8 million tons between 1987 and 2000. In Japan, energy demand is expected to increase at an even faster rate in the 1990s. Given the opposition to nuclear power generation and growing concern about the greenhouse effect, it is likely that LNG will satisfy a major portion of Japan's increasing demand for energy. Japanese gas companies are studying the possibility of establishing a national pipeline network to move gas beyond metropolitan areas

  10. Nonlinear Dynamics of the Cosmic Neutrino Background

    Science.gov (United States)

    Inman, Derek

    At least two of the three neutrino species are known to be massive, but their exact masses are currently unknown. Cosmic neutrinos decoupled from the rest of the primordial plasma early on when the Universe was over a billion times hotter than it is today. These relic particles, which have cooled and are now non-relativistic, constitute the Cosmic Neutrino Background and permeate the Universe. While they are not observable directly, their presence can be inferred by measuring the suppression of the matter power spectrum. This suppression is a linear effect caused by the large thermal velocities of neutrinos, which prevent them from collapsing gravitationally on small scales. Unfortunately, it is difficult to measure because of degeneracies with other cosmological parameters and biases arising from the fact that we typically observe point-like galaxies rather than a continous matter field. It is therefore important to look for new effects beyond linear suppression that may be more sensitive to neutrinos. This thesis contributes to the understanding of the nonlinear dynamics of the cosmological neutrino background in the following ways: (i) the development of a new injection scheme for neutrinos in cosmological N-body simulations which circumvents many issues associated with simulating neutrinos at large redshifts, (ii) the numerical study of the relative velocity field between cold dark matter and neutrinos including its reconstruction from density fields, (iii) the theoretical description of neutrinos as a dispersive fluid and its use in modelling the nonlinear evolution of the neutrino density power spectrum, (iv) the derivation of the dipole correlation function using linear response which allows for the Fermi-Dirac velocity distribution to be properly included, and (v) the numerical study and detection of the dipole correlation function in the TianNu simulation. In totality, this thesis is a comprehensive study of neutrino density and velocity fields that may

  11. Recent trends in Belgium's gas activities

    International Nuclear Information System (INIS)

    Cuijpers, Ch.; Woitrin, D.

    2010-01-01

    This article brings various recent trends together to provide a view of the natural gas activities in Belgium. Belgium has a strategic position as an important nodal point in the North-Western European gas grids. This is illustrated by the high interconnection rate with adjacent networks. Gas volumes are attracted for international transit from border point to border point and to supply the national market. Natural gas represents more than a quarter of Belgium's energy mix and is completely dependent on foreign gas supplies. The Belgian gas market and transmission grid are broken down for H-gas (high calorific value, average of 11,630 kWh/m 3 (n)) and for L-gas (low calorific value, average of 9,769 kWh/m 3 (n)). This article is intended to disclose some statistics in order to contribute to the understanding and benchmarking of Belgium's gas flows, gas consumption, supply diversification and import capacity. (authors)

  12. Gas dusulfurization

    International Nuclear Information System (INIS)

    Powell, B.E.; Bakhshi, V.S.; Randolph, D.A.

    1984-01-01

    A process for adsorbing sulfur dioxide from a gas comprising contacting a gas containing SO 2 , such as a flue gas, with about stoichiometric amounts of a specially prepared calcium oxide so that substantially all of the sulfur dioxide content is reacted throughout the calcium oxide particle to form a calcium sulfate reaction product. The useful calcium oxide particles comprise a highly voided skeletal structure of very large surface area and large pore volume with numerous macro pores. Such particles are obtained by flash calcining sand-size grains of calcium carbonate, such as aragonite, calcite or dolomite

  13. Gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Farahan, E.; Eudaly, J.P.

    1978-10-01

    This evaluation provides performance and cost data for commercially available simple- and regenerative-cycle gas turbines. Intercooled, reheat, and compound cycles are discussed from theoretical basis only, because actual units are not currently available, except on a special-order basis. Performance characteristics investigated include unit efficiency at full-load and off-design conditions, and at rated capacity. Costs are tabulated for both simple- and regenerative-cycle gas turbines. The output capacity of the gas turbines investigated ranges from 80 to 134,000 hp for simple units and from 12,000 to 50,000 hp for regenerative units.

  14. Visualization of gas dissolution following upward gas migration in porous media: Technique and implications for stray gas

    Science.gov (United States)

    Van De Ven, C. J. C.; Mumford, Kevin G.

    2018-05-01

    The study of gas-water mass transfer in porous media is important in many applications, including unconventional resource extraction, carbon storage, deep geological waste storage, and remediation of contaminated groundwater, all of which rely on an understanding of the fate and transport of free and dissolved gas. The novel visual technique developed in this study provided both quantitative and qualitative observations of gas-water mass transfer. Findings included interaction between free gas architecture and dissolved plume migration, plume geometry and longevity. The technique was applied to the injection of CO2 in source patterns expected for stray gas originating from oil and gas operations to measure dissolved phase concentrations of CO2 at high spatial and temporal resolutions. The data set is the first of its kind to provide high resolution quantification of gas-water dissolution, and will facilitate an improved understanding of the fundamental processes of gas movement and fate in these complex systems.

  15. Natural gas market review 2006 - towards a global gas market

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Natural gas is essential to the world economy. Gas now accounts for almost a quarter of OECD primary energy requirements and is expected to become the second most important fuel in the world in the next decade. Industrial and residential consumers increasingly rely on natural gas to keep their houses warm, their lights on and their factories running. Meanwhile the gas industry itself has entered a new phase. Where gas used to be restricted to regional markets, it is now increasingly traded on a global scale. While gas production and transport requires long-term investment, now it is optimised on a short-term basis. Demand continues to grow, but local gas production has become much more expensive. How should we react? How will demand be satisfied? What changes are required to promote flexibility and trade? What are the implications for gas security, investment and interdependence? At stake is an opportunity to diversify supply and demand - but this goal is threatened by barriers to competition and investment. This book is the first of a new IEA publication series. It takes an unprecedented look at developments in natural gas to 2010, analysing not only the three IEA regions (Asia Pacific, North America and Europe) but also broader global trends, such as the interaction of pipeline gas with LNG which binds the regions together. The Review provides invaluable insights for understanding this dynamic market.

  16. Natural gas market review 2006 - towards a global gas market

    International Nuclear Information System (INIS)

    2006-01-01

    Natural gas is essential to the world economy. Gas now accounts for almost a quarter of OECD primary energy requirements and is expected to become the second most important fuel in the world in the next decade. Industrial and residential consumers increasingly rely on natural gas to keep their houses warm, their lights on and their factories running. Meanwhile the gas industry itself has entered a new phase. Where gas used to be restricted to regional markets, it is now increasingly traded on a global scale. While gas production and transport requires long-term investment, now it is optimised on a short-term basis. Demand continues to grow, but local gas production has become much more expensive. How should we react? How will demand be satisfied? What changes are required to promote flexibility and trade? What are the implications for gas security, investment and interdependence? At stake is an opportunity to diversify supply and demand - but this goal is threatened by barriers to competition and investment. This book is the first of a new IEA publication series. It takes an unprecedented look at developments in natural gas to 2010, analysing not only the three IEA regions (Asia Pacific, North America and Europe) but also broader global trends, such as the interaction of pipeline gas with LNG which binds the regions together. The Review provides invaluable insights for understanding this dynamic market

  17. Multivariate Identification of Background Contributions for the H ! tt

    CERN Document Server

    Andrejkovic, Janik Walter

    2016-01-01

    Within the H ! tt analysis it is very important to understand the background contamination in the signal region coming from events where a jet is misidentified as a hadronic tau (fake events). Currently, the fake rate method is used to estimate the number and distributions of fake events in the signal region. This method relies on the correct identification of different background types. The study presented in this report focuses on the use of boosted decision trees in order to identify different background types. It is shown how the addition of more input variables, leading to a multi-dimensional multi-classification task, improves the overall identification accuracy of the different background types.

  18. An EPIC Tale of the Quiescent Particle Background

    Science.gov (United States)

    Snowden, S.L.; Kuntz, K.D.

    2017-01-01

    Extended Source Analysis Software Use Based Empirical Investigation: (1) Builds quiescent particle background (QPB) spectra and images for observations of extended sources that fill (or mostly fill) the FOV i.e., annular background subtraction won't work. (2) Uses a combination of Filter Wheel Closed (FWC) and corner data to capture the spectral, spatial, and temporal variation of the quiescent particle background. New Work: (1) Improved understanding of the QPB (aided by adding a whole lot of data since 2008). (2) Significantly improved statistics (did I mention a LOT more data?). (3) Better characterization and identification of anomalous states. (4) Builds backgrounds for some anomalous state. (5) New efficient method for non-anomalous states.

  19. Town gas plants

    International Nuclear Information System (INIS)

    Anastos, G.J.; Johnson, G.M.; Schapot, R.M.; Velez, V.G.

    1990-01-01

    Town gas plant sites are receiving increasing attention from the utility industry and regulatory communities. This attention has been prompted by greater environmental awareness of impacts due to past disposal practices and the understanding that gas plant wastes contain a wide range of chemical constituents that have persisted in the environment. This paper discusses the history of the town gas plant industry, the various processes utilized and the resultant by-products and wastes. Potential problem areas relating to these sites as well as potential approaches to site characterization are addressed. Included are recommendations for the phasing of site investigations and the use of relatively inexpensive and rapid field screening techniques to identify contamination

  20. Volcanic Gas

    Science.gov (United States)

    ... offensive odor. It is sometimes referred to as sewer gas. Interestingly, the human nose is more sensitive ... the atmosphere where they can potentially cause acid rain. In an ash -producing eruption, ash particles are ...

  1. Gas - flatulence

    Science.gov (United States)

    ... Gas and other symptoms such as stomach pain, rectal pain, heartburn, nausea, vomiting, diarrhea, constipation, fever, or ... Copyright 1997-2018, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing ...

  2. Gas sensor

    International Nuclear Information System (INIS)

    Dorogan, V.; Korotchenkov, Gh.; Vieru, T.; Prodan, I.

    2003-01-01

    The invention relates to the gas sensors on base of metal-oxide films (SnO, InO), which may be used for enviromental control, in the fireextinguishing systema etc. The gas includes an insulating substrate, an active layer, a resistive layer with ohmic contacts. The resistive layer has two or more regions with dofferent resistances , and on the active layer are two or more pairs of ohmic contacts

  3. Natural gas resources in Canada

    International Nuclear Information System (INIS)

    Meneley, R.A.

    2001-01-01

    Natural gas is an important component in many of the technologies aimed at reducing greenhouse gas emissions. In order to understand the role that natural gas can play, it is important to know how much may be present, where it is, when can it be accessed and at what cost. The Canadian Gas Potential Committee has completed its second report 'Natural Gas Potential in Canada - 2001' (CGPC, 2001). This comprehensive study of exploration plays in Canada addresses the two issues of 'how much may be present' and 'where is it'. The Report deals with both conventional gas and non-conventional gas. One hundred and seven Established Conventional Exploration Plays, where discoveries of gas exist, have been assessed in all of the sedimentary basins in Canada. In addition, where sufficient information was available, twelve Conceptual Exploration Plays, where no discoveries have been made, were assessed. Sixty-five other Conceptual Plays were described and qualitatively ranked. An experienced volunteer team of exploration professionals conducted assessments of undiscovered gas potential over a four-year period. The team used technical judgment, statistical techniques and a unique peer review process to make a comprehensive assessment of undiscovered gas potential and estimates of the size of individual undiscovered gas accumulations. The Committee assessed all gas in place in individual exploration plays. For Established Plays, estimates of Undiscovered Nominal Marketable Gas are based on the percentage of the gas in place that is marketable gas in the discovered pools in a play. Not all of the Nominal Marketable Gas will be available. Some underlies areas where exploration is not possible, such as parks, cities and other closed areas. Some will be held in gas pools that are too small to be economic and some of the pools will never be found. In some areas no production infrastructure will be available. Detailed studies of individual exploration plays and basins will be required

  4. Tomorrow, gas

    International Nuclear Information System (INIS)

    Icart, Laura; Jean, Pascale; Georget, Cyrille; Schmill, Rafael

    2017-01-01

    This document contains 12 articles notably addressing the importance of natural gas production and supplies in Europe. The themes of the articles are: the advantages of natural gas in the context of energy and environmental policies, energy diversification, energy supply in the local territories, etc.; the position of GrDF, one of the main French natural gas supplier; LPG (butane, propane), a solution which popularity grows in remote areas; the Gaya project (production of renewable gas from dry biomass); a panorama of gas supply routes in Europe; the situation of gas in Europe's energy supply and consumption; the promotion of LNG fuel for maritime and fluvial ships; why the small scale LNG could be the next revolution; presentation of the new 'Honfleur' ferry (using LNG fuel) that will cross the English Channel by 2019; carbon market and the role of ETS for the energy policy in Europe facing the climatic change challenge; presentation of the French 'Climate Plan' that aims to engage France into a carbon neutrality by 2050; presentation of the French policy against air pollution; economic growth, energy, climate: how to square this circle?

  5. THE EFFECTS OF THE IONIZING RADIATION BACKGROUND ON GALAXY EVOLUTION

    International Nuclear Information System (INIS)

    Hambrick, D. Clay; Ostriker, Jeremiah P.; Naab, Thorsten; Johansson, Peter H.

    2009-01-01

    We find that the amount and nature of the assumed ionizing background can strongly affect galaxy formation and evolution. Galaxy evolution simulations typically incorporate an ultraviolet background which falls off rapidly above z = 3; e.g., that of Haardt and Madau. However, this decline may be too steep to fit the Wilkinson Microwave Anistropy Probe constraints on electron scattering optical depth or observations of intermediate redshift (z ∼ 2-4) Lyα forest transmission. As an alternative, we present simulations of the cosmological formation of individual galaxies with UV backgrounds that decline more slowly at high redshift: both a simple intensity rescaling and the background recently derived by Faucher-Giguere, which softens the spectrum at higher redshifts. We also test an approximation of the X-ray background with a similar z dependence. We find for the test galaxies that an increase in either the intensity or hardness of ionizing radiation generically pushes star formation toward lower redshifts: although overall star formation in the simulation boxes is reduced by 10%-25%, the galaxies show a factor of ∼2 increase in the fraction of stars within a 30 kpc radius that are formed after z = 1. Other effects include late gas inflows enhanced up to 30 times, stellar half-mass radii decreased by up to 30%, central velocity dispersions increased up to 40%, and a strong reduction in substructure. The magnitude of the effects depends on the environmental/accretion properties of the particular galaxy.

  6. First Measurements of Beam Backgrounds at SuperKEKB

    CERN Document Server

    Vahsen, S.E.; Jaegle, I.; Nakayama, H.; Aloisio, A.; Ameli, F.; Barrett, M.; Beaulieu, A.; Bosisio, L.; Branchini, P.; Browder, T.E.; Budano, A.; Cautero, G.; Cecchi, C.; Chen, Y.-T.; Chu, K.-N.; Cinabro, D.; Cristaudo, P.; de Jong, S.; de Sangro, R.; Finocchiaro, G.; Flanagan, J.; Funakoshi, Y.; Gabriel, M.; Giordano, R.; Giuressi, D.; Hedges, M. T.; Honkanen, N.; Ikeda, H.; Ishibashi, T.; Kaji, H.; Kanazawa, K.; Kiesling, C.; Koirala, S.; Križan, P.; La Licata, C.; Lanceri, L.; Liau, J.-J.; Lin, F.-H.; Lin, J.-C.; Liptak, Z.; Longo, S.; Manoni, E.; Marinas, C.; Miyabayashi, K.; Mulyani, E.; Morita, A.; Nakao, M.; Nayak, M.; Ohnishi, Y.; Passeri, A.; Poffenberger, P.; Ritzert, M.; Roney, J M.; Rossi, A.; Röder, T.; Seddon, R.M.; Seong, I.S.; Shiu, J.-G.; Simon, F.; Soloviev, Y.; Suetsugu, Y.; Szalay, M.; Terui, S.; Tortone, G.; van der Kolk, N.; Vitale, L.; Wang, M.Z.; Windel, H.; Yokoyama, S.

    2018-01-01

    The high design luminosity of the SuperKEKB electron-positron collider is expected to result in challenging levels of beam-induced backgrounds in the interaction region. Properly simulating and mitigating these backgrounds is critical to the success of the Belle~II experiment. We report on measurements performed with a suite of dedicated beam background detectors, collectively known as BEAST II, during the so-called Phase 1 commissioning run of SuperKEKB in 2016, which involved operation of both the high energy ring (HER) of 7 GeV electrons as well as the low energy ring (LER) of 4 GeV positrons. We describe the BEAST II detector systems, the simulation of beam backgrounds, and the measurements performed. The measurements include standard ones of dose rates versus accelerator conditions, and more novel investigations, such as bunch-by-bunch measurements of injection backgrounds and measurements sensitive to the energy spectrum and angular distribution of fast neutrons. We observe beam-gas, Touschek, beam-dust...

  7. Seismic reflections associated with submarine gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Andreassen, K

    1996-12-31

    Gas hydrates are often suggested as a future energy resource. This doctoral thesis improves the understanding of the concentration and distribution of natural submarine gas hydrates. The presence of these hydrates are commonly inferred from strong bottom simulating reflection (BSR). To investigate the nature of BSR, this work uses seismic studies of hydrate-related BSRs at two different locations, one where gas hydrates are accepted to exist and interpreted to be very extensive (in the Beaufort Sea), the other with good velocity data and downhole logs available (offshore Oregon). To ascertain the presence of free gas under the BSR, prestack offset data must supplement near-vertical incidence seismic data. A tentative model for physical properties of sediments partially saturated with gas hydrate and free gas is presented. This model, together with drilling information and seismic data containing the BSR beneath the Oregon margin and the Beaufort Sea, made it possible to better understand when to apply the amplitude-versus-offset (AVO) method to constrain BSR gas hydrate and gas models. Distribution of natural gas hydrates offshore Norway and Svalbard is discussed and interpreted as reflections from the base of gas hydrate-bearing sediments, overlying sediments containing free gas. Gas hydrates inferred to exist at the Norwegian-Svalbard continental margin correlate well with Cenozoic depocenters, and the associated gas is assumed to be mainly biogenic. Parts of that margin have a high potential for natural gas hydrates of both biogenic and thermogenic origin. 235 refs., 86 figs., 4 tabs.

  8. Seismic reflections associated with submarine gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Andreassen, K.

    1995-12-31

    Gas hydrates are often suggested as a future energy resource. This doctoral thesis improves the understanding of the concentration and distribution of natural submarine gas hydrates. The presence of these hydrates are commonly inferred from strong bottom simulating reflection (BSR). To investigate the nature of BSR, this work uses seismic studies of hydrate-related BSRs at two different locations, one where gas hydrates are accepted to exist and interpreted to be very extensive (in the Beaufort Sea), the other with good velocity data and downhole logs available (offshore Oregon). To ascertain the presence of free gas under the BSR, prestack offset data must supplement near-vertical incidence seismic data. A tentative model for physical properties of sediments partially saturated with gas hydrate and free gas is presented. This model, together with drilling information and seismic data containing the BSR beneath the Oregon margin and the Beaufort Sea, made it possible to better understand when to apply the amplitude-versus-offset (AVO) method to constrain BSR gas hydrate and gas models. Distribution of natural gas hydrates offshore Norway and Svalbard is discussed and interpreted as reflections from the base of gas hydrate-bearing sediments, overlying sediments containing free gas. Gas hydrates inferred to exist at the Norwegian-Svalbard continental margin correlate well with Cenozoic depocenters, and the associated gas is assumed to be mainly biogenic. Parts of that margin have a high potential for natural gas hydrates of both biogenic and thermogenic origin. 235 refs., 86 figs., 4 tabs.

  9. A Quantitative Gas Chromatographic Ethanol Determination.

    Science.gov (United States)

    Leary, James J.

    1983-01-01

    Describes a gas chromatographic experiment for the quantitative determination of volume percent ethanol in water ethanol solutions. Background information, procedures, and typical results are included. Accuracy and precision of results are both on the order of two percent. (JN)

  10. Geochemical evidence of water-soluble gas accumulation in the Weiyuan gas field, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Shengfei Qin

    2016-01-01

    Full Text Available At present, there are several different opinions on the formation process of the Weiyuan gas field in the Sichuan Basin and the source of its natural gas. In view of the fact that the methane carbon isotope of the natural gas in the Weiyuan gas field is abnormally heavy, the geologic characteristics of gas reservoirs and the geochemical characteristics of natural gas were first analyzed. In the Weiyuan gas field, the principal gas reservoirs belong to Sinian Dengying Fm. The natural gas is mainly composed of methane, with slight ethane and trace propane. The gas reservoirs are higher in water saturation, with well preserved primary water. Then, it was discriminated from the relationship of H2S content vs. methane carbon isotope that the heavier methane carbon isotope of natural gas in this area is not caused by thermochemical sulfate reduction (TSR. Based on the comparison of methane carbon isotope in this area with that in adjacent areas, and combined with the tectonic evolution background, it is regarded that the natural gas in the Weiyuan gas field is mainly derived from water-soluble gas rather than be migrated laterally from adjacent areas. Some conclusions are made. First, since methane released from water is carbon isotopically heavier, the water-soluble gas accumulation after degasification results in the heavy methane carbon isotope of the gas produced from Weiyuan gas field. Second, along with Himalayan movement, great uplift occurred in the Weiyuan area and structural traps were formed. Under high temperature and high pressure, the gas dissolved in water experienced decompression precipitation, and the released natural gas accumulated in traps, consequently leading to the formation of Weiyuan gas field. Third, based on calculation, the amount of natural gas released from water which is entrapped in the Weiyuan gas field after the tectonic uplift is basically equal to the proved reserves of this field, confirming the opinion of water

  11. Understanding engineering mathematics

    CERN Document Server

    Cox, Bill

    2001-01-01

    * Unique interactive style enables students to diagnose their strengths and weaknesses and focus their efforts where needed* Ideal for self-study and tutorial work, building from an initially supportive approach to the development of independent learning skills * Free website includes solutions to all exercises, additional topics and applications, guide to learning mathematics, and practice materialStudents today enter engineering courses with a wide range of mathematical skills, due to the many different pre-university qualifications studied. Bill Cox''s aim is for students to gain a thorough understanding of the maths they are studying, by first strengthening their background in the essentials of each topic. His approach allows a unique self-paced study style, in which students Review their strengths and weaknesses through self-administered diagnostic tests, then focus on Revision where they need it, to finally Reinforce the skills required.The book is structured around a highly successful ''transition'' ma...

  12. New Technologies for Acquisition and 3-D Visualization of Geophysical and Other Data Types Combined for Enhanced Understandings and Efficiencies of Oil and Gas Operations, Deepwater Gulf of Mexico

    Science.gov (United States)

    Thomson, J. A.; Gee, L. J.; George, T.

    2002-12-01

    This presentation shows results of a visualization method used to display and analyze multiple data types in a geospatially referenced three-dimensional (3-D) space. The integrated data types include sonar and seismic geophysical data, pipeline and geotechnical engineering data, and 3-D facilities models. Visualization of these data collectively in proper 3-D orientation yields insights and synergistic understandings not previously obtainable. Key technological components of the method are: 1) high-resolution geophysical data obtained using a newly developed autonomous underwater vehicle (AUV), 2) 3-D visualization software that delivers correctly positioned display of multiple data types and full 3-D flight navigation within the data space and 3) a highly immersive visualization environment (HIVE) where multidisciplinary teams can work collaboratively to develop enhanced understandings of geospatially complex data relationships. The initial study focused on an active deepwater development area in the Green Canyon protraction area, Gulf of Mexico. Here several planned production facilities required detailed, integrated data analysis for design and installation purposes. To meet the challenges of tight budgets and short timelines, an innovative new method was developed based on the combination of newly developed technologies. Key benefits of the method include enhanced understanding of geologically complex seabed topography and marine soils yielding safer and more efficient pipeline and facilities siting. Environmental benefits include rapid and precise identification of potential locations of protected deepwater biological communities for avoidance and protection during exploration and production operations. In addition, the method allows data presentation and transfer of learnings to an audience outside the scientific and engineering team. This includes regulatory personnel, marine archaeologists, industry partners and others.

  13. Gas attack

    Energy Technology Data Exchange (ETDEWEB)

    North, D.

    1977-08-01

    Consumersfirst Ltd. is reacting to deregulation with a massive advertising campaign. The gas utility is owned by Consumers Gas Energy Inc., and is struggling to hold onto its 35 per cent share of Ontario`s two million residential natural gas buyers. An industry analyst pointed out that deregulation could mean that Consumers` Gas has much to lose: customers, market share, control of the assets and control of the process. The Ontario Energy Board (OEB) however, had specified that Consumersfirst is not to proceed with paperwork to sign up new customers until the OEB issues a draft code-of-conduct that would prevent cross-subsidizing between regulated franchise holders. This has now been done, and several heavyweights such as Calgary-based Suncor Energy Inc., Union Gas of Chatham, Ontario, and the US-based Enron Corp. of Houston, have started campaigns to sign up potential consumers. It is predicted that brand loyalty will be a factor, but in the end, like long distance telephone rates, it will all come down to pricing, and a winning formula is not easy to find.

  14. [The genetic background for the eye malformations anophthalmia and microphthalmia].

    Science.gov (United States)

    Roos, Laura Sønderberg; Grønskov, Karen; Jensen, Hanne; Tümer, Zeynep

    2012-03-12

    Anophthalmia and microphthalmia (AO/MO) are rare congenital eye malformations, in which the eyeball is apparently absent or smaller than normal, which causes various degrees of visual impairment. Over 200 different AO/MO-related syndromes have been described, but the genetic background is unknown in many cases. The aim of this article is to give an overview of AO/MO, focusing on the genetic background. It is illustrated that the future identification of new AO/MO related genes will benefit in the genetic counseling of AO/MO patients, and in the understanding of eye development and congenital eye malformations.

  15. The Physics of the Cosmic Microwave Background

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, John [Royal Observatory, Edinburgh (United Kingdom)

    2007-04-07

    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

  16. The impact of electricity restructuring on the natural gas industry

    International Nuclear Information System (INIS)

    Given, G.

    1999-03-01

    The main objective of the study is to quantify the impact of electrical restructuring on the natural gas industry, in particular the expected rise in natural gas consumption for electricity generation in Canada from 2000 to 2020. To this end, the study estimates how large the demand potential is and where it is likely to materialize, with the timing of these events also considered. Chapter two discusses the study methodology, which is that of a quantitative forecast. Before an analytical model was chosen, a careful review of potential candidates, a literature review, and an analysis of important issues were undertaken. Chapter three provides requisite background information of electricity restructuring issues. U.K. experiences are highlighted, and common issues and differences among states and provinces are discussed also. Chapter four provides some necessary historical background and puts into perspective the importance of gas consumption for electric generation. Also treated are relevant Canadian and U.S. generation and capacity, and forecasts of restructuring impacts from other organizations. Whether a consensus forecast for gas demand exists is examined, as well as a number of critical factors examined in various studies. Chapter five describes the development of individual study scenarios and key assumptions contained in each scenario. Also described are some of the selected model's capabilities. Retail and generation company strategy parameters are highlighted to provide a better understanding of those capabilities. The competition parameters chosen for generators and retail companies in the model are described. Chapter six reports all key forecast variables in a discussion which compares relevant scenario and sensitivity forecast results. Detailed forecast results for two scenarios are provided in appendices. Chapter seven discusses new investment and business opportunities and challenges in light of the forecast results. These are reviewed for a number of

  17. Clean air strategy for Alberta: Background project reports

    International Nuclear Information System (INIS)

    1991-06-01

    As a background to the development of a clean air strategy for Alberta, reports are presented which cover the definition of what clean air is, the applicability of full cost accounting to this strategy, market-based approaches to managing Alberta air emissions, gas and electric utility incentives programs for energy efficiency, energy efficiency legislation in Alberta and other jurisdictions, initiatives which address emissions reduction in the transportation sector, coordination of science and technology relevant to clean air issues, and initiatives in energy and environmental education

  18. Preparation of 'dead water' for low background liquid scintillation counting

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Niwa, Takeo; Kawai, Hiroshi

    1987-01-01

    'Dead water', low level tritiated water is indispensable to measure tritium concentration in environmental waters using a low background liquid scintillation counter. Water produced by combustion of natural gas, or deep sea water etc. are usually used for the above purpose. A new method of reducing tritium concentration in natural water has been introduced for preparation of 'dead water'. This method is to combine hydrogen-oxygen mixture produced by water electrolysis with hopcalite catalyzer at 700 deg C. Deep well water was electrolized up to 2/3 volume, and tritium concentration of recombined water was reduced to be about one third of that of the original one. (author)

  19. Gas hydrates

    Digital Repository Service at National Institute of Oceanography (India)

    Ramprasad, T.

    , not all of them are white like snow. Some hydrates from the deep Gulf of Mexico are richly colored in shades of yellow, orange, or even red. The ice-like masses are beautiful, and contrast with the dull gray of deep sea muds. Hydrates from the Blake... volcanoes and associated gas hydrates: Marine Geology, v. 167, p. 29-42. Milkov, A.V. and R. Sassen, 2001a, Estimate of gas hydrate resource, northwestern Gulf of Mexico continental slope: Marine Geology, v. 179, pp. 71-83. Milkov, A.V., Sassen, R...

  20. Theories of fission gas behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Dias, J W.C. [Companhia Brasileira de Tecnologia Nuclear, Rio de Janeiro (Brazil). Diretoria de Tecnologia e Desenvolvimento; Merckx, K R

    1976-01-01

    A review is presented of the theoretical developments and experimental evidence that have helped to evolve current models used to describe the behavior of inert fission gases created during the irradiation of reactor fuel materials. The phenomena which are stressed relate primarily to steady state behavior of fuel elements but are also relevant to an understanding of transient behavior. The processes considered include gas atom solubility; gas atom diffusivity; bubble nucleation; and bubble growth by bubble coalescence.

  1. Gas Turbine Engine Behavioral Modeling

    OpenAIRE

    Meyer, Richard T; DeCarlo, Raymond A.; Pekarek, Steve; Doktorcik, Chris

    2014-01-01

    This paper develops and validates a power flow behavioral model of a gas tur- bine engine with a gas generator and free power turbine. “Simple” mathematical expressions to describe the engine’s power flow are derived from an understand- ing of basic thermodynamic and mechanical interactions taking place within the engine. The engine behavioral model presented is suitable for developing a supervisory level controller of an electrical power system that contains the en- gine connected to a gener...

  2. Leader propagation in uniform background fields in SF6

    International Nuclear Information System (INIS)

    Seeger, M; Niemeyer, L; Bujotzek, M

    2009-01-01

    The breakdown mechanism of compressed SF 6 in gas insulation is known to be controlled by stepped leader propagation. This process is still not well understood in uniform and weakly non-uniform background fields with small electrode protrusions, such as particles or surface roughness. In a previous publication an investigation of partial discharges and breakdown in uniform background fields that focused on streamer and leader inception mechanisms was presented (Seeger et al 2008 J. Phys. D: Appl. Phys. 41 185204). In this paper we present for the first time a physical leader propagation model that consistently describes the observed phenomena in uniform background fields in SF 6 . The model explains two different types of leader breakdown; these can be associated with the precursor and the stem mechanisms. It also yields the parameters of stepped leader propagation, which include step lengths, associated step charges, step times and fields and temperatures in the leader channel. Further, it explains the features of arrested leaders in uniform background fields. The model predicts the range of parameters under which arrested and breakdown leaders occur in good agreement with the experimental data.

  3. Cowdung gas

    Energy Technology Data Exchange (ETDEWEB)

    A basic guide for the design and construction of a small biogas plant is presented. The gas holder consists of a battery of seven used oil drums bound together with interconnected via plastic piping. Most other components, with the exception of metal valves and joints, are made of wood, stone or cement.

  4. Gas sensor

    Science.gov (United States)

    Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

    2014-09-09

    A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

  5. Manure gas

    Energy Technology Data Exchange (ETDEWEB)

    Carre, I

    1948-11-01

    Descriptions are given of several batch digesters: the Algerian, Salubra, Betur, Baudot-Hardoll and Ofla, and Somagaz designs. Sketches of two Ducellier and Isman designs are given with a photograph of an installation consisting of four contiguous, rectangular concrete tanks. There are short explanations of the fundamentals and economics of the process, and of the use of the gas.

  6. Climate Impacts on Northern Canada: Regional Background

    Energy Technology Data Exchange (ETDEWEB)

    Prowse, Terry D.; Peters, Daniel L. (Water and Climate Impacts Research Centre, Environment Canada, Dept. of Geography, Univ. of Victoria, Victoria, BC (Canada)). e-mail: terry.prowse@ec.gc.caa; Furgal, Chris (Indigenous Environmental Studies Program, Trent Univ., Peterborough, ON (Canada)); Bonsal, Barrie R. (National Water Research Inst., National Hydrology Research Centre, Environment Canada, Saskatoon, SK (Canada))

    2009-07-15

    Understanding the implications of climate change on northern Canada requires a background about the size and diversity of its human and biogeophysical systems. Occupying an area of almost 40% of Canada, with one-third of this contained in Arctic islands, Canada's northern territories consist of a diversity of physical environments unrivaled around the circumpolar north. Major ecozones composed of a range of landforms, climate, vegetation, and wildlife include: Arctic, boreal and taiga cordillera; boreal and taiga plains; taiga shield; and northern and southern Arctic. Although generally characterized by a cold climate, there is an enormous range in air temperature with mean annual values being as high as -5 deg C in the south to as low as -20 deg C in the high Arctic islands. A similar contrast characterizes precipitation, which can be >700 mm y-1 in some southern alpine regions to as low as 50 mm y-1 over islands of the high Arctic. Major freshwater resources are found within most northern ecozones, varying from large glaciers or ice caps and lakes to extensive wetlands and peat lands. Most of the North's renewable water, however, is found within its major river networks and originates in more southerly headwaters. Ice covers characterize the freshwater systems for multiple months of the year while permafrost prevails in various forms, dominating the terrestrial landscape. The marine environment, which envelops the Canadian Arctic Archipelago, is dominated by seasonal to multiyear sea ice often several meters thick that plays a key role in the regional climate. Almost two-thirds of northern Canadian communities are located along coastlines with the entire population being just over 100 000. Most recent population growth has been dominated by an expansion of nonaboriginals, primarily the result of resource development and the growth of public administration. The economies of northern communities, however, remain quite mixed with traditional land

  7. Temperature fluctuations superimposed on background temperature change

    International Nuclear Information System (INIS)

    Otto, James; Roberts, J.A.

    2016-01-01

    Proxy data allows the temperature of the Earth to be mapped over long periods of time. In this work the temperature fluctuations for over 200 proxy data sets were examined and from this set 50 sets were analyzed to test for periodic and quasi-periodic fluctuations in the data sets. Temperature reconstructions over 4 different time scales were analyzed to see if patterns emerged. Data were put into four time intervals; 4,000 years, 14,000 years, 1,000,000 years, and 3,000,000 years and analyzed with a goal to understanding periodic and quasi-periodic patterns in global temperature change superimposed on a “background” average temperature change. Quasi-periodic signatures were identified that predate the Industrial Revolution, during much of which direct data on temperature are not available. These data indicate that Earth temperatures have undergone a number of periodic and quasi-periodic intervals that contain both global warming and global cooling cycles. The fluctuations are superimposed on a background of temperature change that has a declining slope during the two periods, pre-ice age and post ice age with a transition about 12,000 BCE. The data are divided into “events” that span the time periods 3,000,000 BCE to “0” CE, 1,000,000 BCE to “0” CE, 12,000 BCE to 2,000 CE and 2,000 BCE to 2,000 CE. An equation using a quasi-periodic (frequency modulated sine waves) patterns was developed to analyze the date sets for quasi-periodic patterns. “Periodicities” which show reasonable agreement with the predictions of Milankovitch and other investigators were found in the data sets.

  8. Pure- and Mixed-Gas Transport Study of Nafion® and Its Fe3+-Substituted Derivative for Membrane-Based Natural Gas Applications

    KAUST Repository

    Mukaddam, Mohsin Ahmed

    2016-01-01

    The focus of this research project was to develop a fundamental understanding of the structure-gas transport property relationship in Nafion® to investigate its potential use as a gas separation membrane material for natural gas (NG) applications

  9. The Physics of the Cosmic Microwave Background

    International Nuclear Information System (INIS)

    Peacock, John

    2007-01-01

    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

  10. Assessment of Radiation Background Variation for Moving Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James Christopher [Los Alamos National Laboratory; Rennie, John Alan [Los Alamos National Laboratory; Toevs, James Waldo [Los Alamos National Laboratory; Wallace, Darrin J. [Los Alamos National Laboratory; Abhold, Mark Edward [Los Alamos National Laboratory

    2015-07-13

    The introduction points out that radiation backgrounds fluctuate across very short distances: factors include geology, soil composition, altitude, building structures, topography, and other manmade structures; and asphalt and concrete can vary significantly over short distances. Brief descriptions are given of the detection system, experimental setup, and background variation measurements. It is concluded that positive and negative gradients can greatly reduce the detection sensitivity of an MDS: negative gradients create opportunities for false negatives (nondetection), and positive gradients create a potentially unacceptable FAR (above 1%); the location of use for mobile detection is important to understand; spectroscopic systems provide more information for screening out false alarms and may be preferred for mobile use; and mobile monitor testing at LANL accounts for expected variations in the background.

  11. 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...... was varied. Results suggest that the combined effect of short compression release times, a low working memory capacity and glimpsing due to presence of amplitude modulation results in poor speech recognition performance. There was no interaction between working memory and different noise backgrounds...... 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 situations involve modulated noise. The investigation was carried out by testing two groups of older adults...

  12. Modeling the Thermal Signature of Natural Backgrounds

    National Research Council Canada - National Science Library

    Gamborg, Marius

    2002-01-01

    Two measuring stations have been established the purpose being to collect comprehensive databases of thermal signatures of background elements in addition to the prevailing meteorological conditions...

  13. Hybrid Simulation of Supersonic Flow of Weakly Ionized Plasma along Open Field Magnetic Line Effect of Background Pressure

    Science.gov (United States)

    Laosunthara, Ampan; Akatsuka, Hiroshi

    2016-09-01

    In previous study, we experimentally examined physical properties of supersonic flow of weakly ionized expanding arc-jet plasma through an open magnetic field line (Bmax 0.16T). We found supersonic velocity of helium plasma up to Mach 3 and the space potential drop at the end of the magnets. To understand the plasma in numerical point of view, the flows of ion and neutral are treated by particle-based Direct Simulation Monte Carlo (DSMC) method, electron is treated as a fluid. The previous numerical study, we assumed 2 conditions. Ion and electron temperatures were the same (LTE condition). Ion and electron velocities were the same (current-free condition). We found that ion velocity decreased by collision with residual gas molecules (background pressure). We also found that space potential changing with background pressure. In other words, it was indicated that electric field exists and the current-free assumption is not proper. In this study, we add electron continuity and electron momentum equations to obtain electron velocity and space potential. We find that space potential changing with background pressure slightly. It is indicated that electron is essential to space potential formation than ion.

  14. Shape understanding system machine understanding and human understanding

    CERN Document Server

    Les, Zbigniew

    2015-01-01

    This is the third book presenting selected results of research on the further development of the shape understanding system (SUS) carried out by authors in the newly founded Queen Jadwiga Research Institute of Understanding. In this book the new term Machine Understanding is introduced referring to a new area of research aiming to investigate the possibility of building machines with the ability to understand. It is presented that SUS needs to some extent mimic human understanding and for this reason machines are evaluated according to the rules applied for the evaluation of human understanding. The book shows how to formulate problems and how it can be tested if the machine is able to solve these problems.    

  15. A statistical background noise correction sensitive to the steadiness of background noise.

    Science.gov (United States)

    Oppenheimer, Charles H

    2016-10-01

    A statistical background noise correction is developed for removing background noise contributions from measured source levels, producing a background noise-corrected source level. Like the standard background noise corrections of ISO 3741, ISO 3744, ISO 3745, and ISO 11201, the statistical background correction increases as the background level approaches the measured source level, decreasing the background noise-corrected source level. Unlike the standard corrections, the statistical background correction increases with steadiness of the background and is excluded from use when background fluctuation could be responsible for measured differences between the source and background noise levels. The statistical background noise correction has several advantages over the standard correction: (1) enveloping the true source with known confidence, (2) assuring physical source descriptions when measuring sources in fluctuating backgrounds, (3) reducing background corrected source descriptions by 1 to 8 dB for sources in steady backgrounds, and (4) providing a means to replace standardized background correction caps that incentivize against high precision grade methods.

  16. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    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.

  17. Qatar: Background and U.S. Relations

    National Research Council Canada - National Science Library

    Blanchard, Christopher M

    2008-01-01

    .... military facilities for command, basing, and equipment pre-positioning. Qatar holds the third largest proven natural gas reserves in the world, and its small population enjoys the highest per capita income of any Middle Eastern country...

  18. 41 CFR 128-1.8001 - Background.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Background. 128-1.8001 Section 128-1.8001 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF JUSTICE 1-INTRODUCTION 1.80-Seismic Safety Program § 128-1.8001 Background. The...

  19. Introduction to the background field method

    International Nuclear Information System (INIS)

    Abbott, L.F.; Brandeis Univ., Waltham, MA

    1982-01-01

    The background field approach to calculations in gauge field theories is presented. Conventional functional techniques are reviewed and the background field method is introduced. Feynman rules and renormalization are discussed and, as an example, the Yang-Mills β function is computed. (author)

  20. 12 CFR 408.1 - Background.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Background. 408.1 Section 408.1 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES PROCEDURES FOR COMPLIANCE WITH THE NATIONAL ENVIRONMENTAL POLICY ACT General § 408.1 Background. (a) The National Environmental Policy Act (NEPA) of 1969 (42 U.S.C...

  1. Observing a Gravitational Wave Background With Lisa

    National Research Council Canada - National Science Library

    Tinto, M; Armstrong, J; Estabrook, F

    2000-01-01

    .... Comparison of the conventional Michelson interferometer observable with the fully-symmetric Sagnac data-type allows unambiguous discrimination between a gravitational wave background and instrumental noise. The method presented here can be used to detect a confusion-limited gravitational wave background.

  2. 28 CFR 23.2 - Background.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Background. 23.2 Section 23.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is... potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally...

  3. 16 CFR 1404.2 - Background.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Background. 1404.2 Section 1404.2 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS CELLULOSE INSULATION § 1404.2 Background. Based on available fire incident information, engineering analysis of the probable...

  4. Demand and supply in Russian gas market

    International Nuclear Information System (INIS)

    Milovidov, K.N.

    1997-01-01

    The big volume of gas supplies for current and future energy and natural gas balances in Russia is important to understand the likely future dynamics of demand for gas. The path of future demand in Russia is uncertain and the range of possible scenarios is wide. For creating the new gas consumption structure, more deep diversification and development of the gas distribution systems, large investments and considerable periods of time are necessary. The factors usually studied in detail in the conditions of market economy can not be used here as a basis for strategic planning due to several reasons. (R.P.)

  5. 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

  6. Preparing for an influx of foreign students in technical writing courses: Understanding their background

    Science.gov (United States)

    Lipson, C. S.

    1981-01-01

    The cultural and historical influences that students from foreign countries bring with them to technical and report writing classes, in particular those influences that would affect their receipt of instruction in American principles for written prose are examined. The grouping of sentences into idea units and into paragraphs, and the grouping of the paragraphs into whole structures are considered. The different cultures, different habits and norms for handling prose, and the dictates for style and structure and sufficiency and approach are also considered.

  7. Understanding mineral trioxide aggregate/Portland-cement: a review of literature and background factors.

    Science.gov (United States)

    Steffen, R; van Waes, H

    2009-06-01

    This was to carry out a review of the literature concerning mineral trioxide aggregate (MTA) and Portland cement with regards to clinical, biological and mechanical findings and a possible substitution of MTA through Portland cement for endodontic use. Electronic literature search of scientific papers from January 1993 to January 2009 was carried out on the MEDLINE and Scopus databases using specific key words. In total, 57 papers were identified that dealt with MTA and Portland cement in a relevant way. The review of 50 papers conforming to the applied criteria showed that MTA and Portland cements have the same clinical, biological and mechanical properties. In animal experiments and technical characterisations both materials seemed to have very similar properties. The only difference is bismuth oxide in MTA added for better radio opacity. It seems likely that MTA materials are based on industrial Portland cements mixed with bismuth oxide. More studies, especially some long-term studies comparing MTA and Portland cement, are necessary. The existing literature gives a solid base for clinical studies with Portland cement in order to replace MTA as an endodontic material. Portland cement could be a substitute for most endodontic materials used in primary teeth.

  8. Alphas and surface backgrounds in liquid argon dark matter detectors

    Science.gov (United States)

    Stanford, Christopher J.

    Current observations from astrophysics indicate the presence of dark matter, an invisible form of matter that makes up a large part of the mass of the universe. One of the leading theories for dark matter is that it is made up of Weakly Interacting Massive Particles (WIMPs). One of the ways we try to discover WIMPs is by directly detecting their interaction with regular matter. This can be done using a scintillator such as liquid argon, which gives off light when a particle interacts with it. Liquid argon (LAr) is a favorable means of detecting WIMPs because it has an inherent property that enables a technique called pulse-shape discrimination (PSD). PSD can distinguish a WIMP signal from the constant background of electromagnetic signals from other sources, like gamma rays. However, there are other background signals that PSD is not as capable of rejecting, such as those caused by alpha decays on the interior surfaces of the detector. Radioactive elements that undergo alpha decay are introduced to detector surfaces during construction by radon gas that is naturally present in the air, as well as other means. When these surface isotopes undergo alpha decay, they can produce WIMP-like signals in the detector. We present here two LAr experiments. The first (RaDOSE) discovered a property of an organic compound that led to a technique for rejecting surface alpha decays in LAr detectors with high efficiency. The second (DarkSide-50) is a dark matter experiment operated at LNGS in Italy and is the work of an international collaboration. A detailed look is given into alpha decays and surface backgrounds present in the detector, and projections are made of alpha-related backgrounds for 500 live days of data. The technique developed with RaDOSE is applied to DarkSide-50 to determine its effectiveness in practice. It is projected to suppress the surface background in DarkSide-50 by more than a factor of 1000.

  9. String pair production in non homogeneous backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, S. [Department of Physics “E. Fermi” University of Pisa, and INFN - Sezione di Pisa,Largo Pontecorvo, 3, Ed. C, 56127 Pisa (Italy); Rabinovici, E. [Racah Institute of Physics, The Hebrew University of Jerusalem,91904 Jerusalem (Israel); Tallarita, G. [Departamento de Ciencias, Facultad de Artes Liberales,Universidad Adolfo Ibáñez, Santiago 7941169 (Chile)

    2016-04-28

    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.

  10. String pair production in non homogeneous backgrounds

    International Nuclear Information System (INIS)

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

    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 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.

  11. Slavnov-Taylor constraints for nontrivial backgrounds

    International Nuclear Information System (INIS)

    Binosi, D.; Quadri, A.

    2011-01-01

    We devise an algebraic procedure for the evaluation of Green's functions in SU(N) Yang-Mills theory in the presence of a nontrivial background field. In the ghost-free sector the dependence of the vertex functional on the background is shown to be uniquely determined by the Slavnov-Taylor identities in terms of a certain 1-PI correlator of the covariant derivatives of the ghost and the antighost fields. At nonvanishing background this amplitude is shown to encode the quantum deformations to the tree-level background-quantum splitting. The approach only relies on the functional identities of the model (Slavnov-Taylor identities, b-equation, antighost equation) and thus it is valid beyond perturbation theory, and, in particular, in a lattice implementation of the background field method. As an example of the formalism we analyze the ghost two-point function and the Kugo-Ojima function in an instanton background in SU(2) Yang-Mills theory, quantized in the background Landau gauge.

  12. Gas contracting following the introduction of competition into the U.K. gas market

    International Nuclear Information System (INIS)

    Aron, D.

    1992-01-01

    The paper discusses the changing nature of gas contracting in the UK. As background the paper will review the advantages and disadvantages of the old system of gas sales. Finally the paper seeks to address some of the new opportunities and problems that are arising under the new competitive arrangements

  13. 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.

  14. 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.)

  15. Modeling Lost-Particle Accelerator Backgrounds in PEP-II Using LPTURTLE

    CERN Document Server

    Fieguth, Theodore; Kozanecki, Witold

    2005-01-01

    Background studies during the design, construction, commissioning, operation and improvement of BaBar and PEP-II have been greatly influenced by results from a program referred to as LPTURTLE (Lost Particle TURTLE a modified version of Decay TURTLE) which was originally conceived for the purpose of studying gas background for SLC. This venerable program is still in use today. We describe its use, capabilities and improvements and refer to current results now being applied to BaBar.

  16. α-rays induced background in ultra low level counting with Ge spectrometers

    International Nuclear Information System (INIS)

    Hubert, P.; Dassie, D.; Larrieu, P.; Leccia, F.; Mennrath, P.; Chevallier, J.; Chevallier, A.; Morales, A.; Nunez-Lagoz, R.; Morales, J.; Villar, J.A.

    1986-01-01

    Background spectra of several spectrometers have been recorded in a deep underground laboratory located in the Frejus tunnel. The results show that an α ray induced background from the 210 Pb decay is observed. A possible explanation could be related to the adsorption of the Rn gas on the surfaces of the Ge crystal and/or other parts during the assembly of the spectrometer. (orig.)

  17. Quasi zero-background tunable diode laser absorption spectroscopy employing a balanced Michelson interferometer.

    Science.gov (United States)

    Guan, Zuguang; Lewander, Märta; Svanberg, Sune

    2008-12-22

    Tunable diode laser spectroscopy (TDLS) normally observes small fractional absorptive reductions in the light flux. We show, that instead a signal increase on a zero background can be obtained. A Michelson interferometer, which is initially balanced out in destructive interference, is perturbed by gas absorption in one of its arms. Both theoretical analysis and experimental demonstration show that the proposed zero-background TDLS can improve the achievable signal-to-noise ratio.

  18. Gas chromatography

    International Nuclear Information System (INIS)

    Cram, S.P.; Risby, T.H.; Field, L.R.; Yu, W.L.

    1980-01-01

    In addition to the published literature for the years 1978 - 79, this review of developments in the field of gas chromatography includes earlier articles of particular significance appearing in foreign journals and the patent literature which was not available at the time of the previous review. The articles cited were selected as presenting the most fundamental developments in theory, methodology, and instrumentation. Some applications are cited if they reflect an advance in the state-of-the-art or have particular relevance to new developments. 1149 references are cited

  19. Natural gas marketing II

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This book covers all aspects of gas marketing, from the basic regulatory structure to the latest developments in negotiating agreements and locating markets. Topics include: Federal regulation of the gas industry; Fundamentals of gas marketing contracts; FERC actions encouraging competitive markets; Marketing conditions from the pipelines' perspective; State non-utility regulation of natural gas production, transportation, and marketing; Natural gas wellhead agreements and tariffs; Natural gas processing agreements; Effective management of producer's natural gas contracts; Producer-pipeline litigation; Natural gas purchasing from the perspective of industrial gas users; Gas marketing by co-owners: problems of disproportionate sales, gas balancing, and accounting to royalty owners; Alternatives and new directions in marketing

  20. On the microwave background spectrum and noise

    International Nuclear Information System (INIS)

    De Bernardis, P.; Masi, S.

    1982-01-01

    We show that the combined measurement of the cosmic background radiation (CBR) intensity and noise can provide direct information on the temperature and the emissivity of the source responsible for the CBR. (orig.)

  1. Background-cross-section-dependent subgroup parameters

    International Nuclear Information System (INIS)

    Yamamoto, Toshihisa

    2003-01-01

    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)

  2. REQUEST FOR EXPRESSIONS OF INTEREST For Background ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    sbickram

    2012-07-10

    Jul 10, 2012 ... the applicant's qualifications and ability to undertake the hot spot background study. ... any interviews, presentations and subsequent proposals, are the sole ... The program will focus on increasing the resilience of the most ...

  3. Background music: effects on attention performance.

    Science.gov (United States)

    Shih, Yi-Nuo; Huang, Rong-Hwa; Chiang, Hsin-Yu

    2012-01-01

    Previous studies indicate that noise may affect worker attention. However, some background music in the work environment can increase worker satisfaction and productivity. This study compared how music with, and without, lyrics affects human attention. One hundred and two participants, aged 20-24 years, were recruited into this study. Fifty-six males and 46 females participated in this study. Background music with, and without lyrics, was tested for effects on listener concentration in attention testing using a randomized controlled trial (RCT) study. The comparison results revealed that background music with lyrics had significant negative effects on concentration and attention. The findings suggest that, if background music is played in the work environment, music without lyrics is preferable because songs with lyrics are likely to reduce worker attention and performance.

  4. History and background of the project

    Digital Repository Service at National Institute of Oceanography (India)

    Jauhari, P.; Nair, R.R.

    The history of oceanography, the discovery of manganese nodules and the background of the developments in nodule research and mining is given The first nodules were collected in 1981 on board the research vessel R V Gaveshani Following the success...

  5. 47 CFR 215.1 - Background.

    Science.gov (United States)

    2010-10-01

    ... POINT FOR ELECTROMAGNETIC PULSE (EMP) INFORMATION § 215.1 Background. (a) The nuclear electromagnetic pulse (EMP) is part of the complex environment produced by nuclear explosions. It consists of transient...

  6. 32 CFR 770.49 - Background.

    Science.gov (United States)

    2010-07-01

    ..., Washington § 770.49 Background. (a) Puget Sound Naval Shipyard is a major naval ship repair facility, with... interruption. Additionally, most of Puget Sound Naval Shipyard is dedicated to heavy industrial activity where...

  7. 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....

  8. A Practical Theorem on Gravitational Wave Backgrounds

    OpenAIRE

    Phinney, E. S.

    2001-01-01

    There is an extremely simple relationship between the spectrum of the gravitational wave background produced by a cosmological distribution of discrete gravitational wave sources, the total time-integrated energy spectrum of an individual source, and the present-day comoving number density of remnants. Stated in this way, the background is entirely independent of the cosmology, and only weakly dependent on the evolutionary history of the sources. This relationship allows one easily to compute...

  9. Isotherms clustering in cosmic microwave background

    International Nuclear Information System (INIS)

    Bershadskii, A.

    2006-01-01

    Isotherms clustering in cosmic microwave background (CMB) has been studied using the 3-year WMAP data on cosmic microwave background radiation. It is shown that the isotherms clustering could be produced by the baryon-photon fluid turbulence in the last scattering surface. The Taylor-microscale Reynolds number of the turbulence is estimated directly from the CMB data as Re λ ∼10 2

  10. Classification of supersymmetric backgrounds of string theory

    International Nuclear Information System (INIS)

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

    2007-01-01

    We review the recent progress made towards the classification of supersymmetric solutions in ten and eleven dimensions with emphasis on those of IIB supergravity. In particular, the spinorial geometry method is outlined and adapted to nearly maximally supersymmetric backgrounds. We then demonstrate its effectiveness by classifying the maximally supersymmetric IIB G-backgrounds and by showing that N=31 IIB solutions do not exist. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  11. Superstring gravitational wave backgrounds with spacetime supersymmetry

    CERN Document Server

    Kiritsis, Elias B; Lüst, Dieter; Kiritsis, E; Kounnas, C; Lüst, D

    1994-01-01

    We analyse the stringy gravitational wave background based on the current algebra E.sup(c).sub(2). We determine its exact spectrum and construct the modular invariant vacuum energy. The corresponding N=1 extension is also constructed. The algebra is again mapped to free bosons and fermions and we show that this background has N=4 (N=2) unbroken spacetime supersymmetry in the type II (heterotic case).

  12. Background dose subtraction in personnel dosimetry

    International Nuclear Information System (INIS)

    Picazo, T.; Llorca, N.; Alabau, J.

    1997-01-01

    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)

  13. 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

  14. Gas Evolution in Protoplanetary Disks

    NARCIS (Netherlands)

    Woitke, Peter; Dent, Bill; Thi, Wing-Fai; Sibthorpe, Bruce; Rice, Ken; Williams, Jonathan; Sicilia-Aguilar, Aurora; Brown, Joanna; Kamp, Inga; Pascucci, Ilaria; Alexander, Richard; Roberge, Aki

    2009-01-01

    This article summarizes a Splinter Session at the Cool Stars XV conference in St. Andrews with 3 review and 4 contributed talks. The speakers have discussed various approaches to understand the structure and evolution of the gas component in protoplanetary disks. These ranged from observational

  15. Aircraft and background noise annoyance effects

    Science.gov (United States)

    Willshire, K. F.

    1984-01-01

    To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

  16. Low energy background radiation in India

    International Nuclear Information System (INIS)

    Gopinath, D.V.

    1980-01-01

    Spectral distribution of background radiation at 9 locations spread all over India has been measured. Specifications of the counting set-up standardised for measurement are given. At one of the places, the background spectrum was measured with four different types of detectors. A broad peak in 60-100 keV with differing intensity and standard deviation is observed in all the spectra. In the Kalpakkam area, the peak near the seashore is observed to be more intense than away from the shore. This could be due to the presence of monazite sands on the seashore. The natural background radiation is observed to have a steep rise below 20 keV. Peak intensity is found to be independent of both the location (i.e. the source of energy) and the type of detector used for measurement. The calculated spectra due to multiple scattered radiation (with a nominal source energy of 1 MeV) through paraffin wax and the measured background spectrum with the detector shielded with 20 cm wax show good agreement above 40 keV. This shows that 80 keV hump in the natural background radiation is a property of air. The peak, therefore, in the spectra of natural background radiation is essentially a property of medium and it is independent of location or detector. (M.G.B.)

  17. Background of SAM atom-fraction profiles

    International Nuclear Information System (INIS)

    Ernst, Frank

    2017-01-01

    Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition

  18. Background of SAM atom-fraction profiles

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Frank

    2017-03-15

    Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition.

  19. Broad Bandwidth Metamaterial Antireflection Coatings for Measurement of the Cosmic Microwave Background

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cosmic Microwave Background (CMB) contains a number of faint signals that, if measured, could revolutionize our understandings of the Universe and fundamental...

  20. Spectral Analysis of the Background in Ground-based, Long-slit ...

    Indian Academy of Sciences (India)

    1996-12-08

    Dec 8, 1996 ... Spectral Analysis of the Background in Ground-based,. Long-slit .... Figure 1 plots spectra from the 2-D array, after instrumental calibration and before correction for ..... which would merit attention and a better understanding.

  1. Oils; gas

    Energy Technology Data Exchange (ETDEWEB)

    Day, D T

    1922-09-18

    Oils and gas are obtained from shale or oil-bearing sand by immersing the shale in and passing it through a bath of liquid oil, cracking the oil-soaked shale, and condensing the vapor and using the condensate to replenish the bath, preferably by passing the gases and vapors direct into the oil-bath container. Shale is fed continuously from a hopper to a bath of oil in an inclined chamber, is carried to the outlet by a conveyer, and through cracking tubes to an outlet pipe by conveyers. The gases and vapors escape by the pipe, a part condensing in the chamber and a run-back pipe and replenishing the bath, and the remainder passing through a condensing tower and condenser connected to reservoirs; the gas is further passed through a scrubber and a pipe to the burner of the retort. The oil condensed in the chamber overflows to the reservoir through a pipe provided with an open pipe to prevent siphoning. The conveyers and a valve on the pipe are operated by gearing. The operation may be conducted at reduced, normal, or increased pressure, e.g., 70 lbs. The temperature of the retort should be about 900 to 1400/sup 0/F, that of the inside of the tubes about 550 to 700/sup 0/F, and that of the chamber about 300/sup 0/F. The chamber and pipe may be insulated or artificially cooled.

  2. Gas Warfare in World War I.

    Science.gov (United States)

    Flintham, A. J.

    1978-01-01

    The effectiveness of gas warfare during World War I was increased by the lack of a basic understanding of the behavior of gases on the part of the soldiers. This was a result of deficiencies in science education. (BB)

  3. Ambient Aerosols in the Southern Hemisphere on Ascension Island during the LASIC Campaign: Biomass Burning Season versus Near Pristine Background Conditions

    Science.gov (United States)

    Aiken, A. C.; Springston, S. R.; Watson, T. B.; Sedlacek, A. J., III; Zuidema, P.; Adebiyi, A. A.; Uin, J.; Kuang, C.; Flynn, C. J.

    2017-12-01

    Ascension Island is located 8 degrees South of the Equator and 15 degrees West Longitude in the middle of the South Atlantic Ocean, at least 1000 miles from any major shoreline and closest to the continent of Africa. While low Southern Hemisphere background aerosol and trace gas measurements are observed most of the year, that picture changes during the South African Biomass Burning (BB) season. BB emissions are a large source of carbon to the atmosphere via particles and gas phase species and with a potential rise in drought and extreme events in the future, these numbers are expected to increase. From approximately June-October every year, the plume of South African BB emissions, the largest BB source in the world, are advected West and are known to impact both the boundary layer and free troposphere at Ascension Island (Zuidema et al., 2016). During the U.S. DOE ARM field campaign, Layered Atlantic Smoke Interactions with Clouds (LASIC), aerosol and trace gas measurements were collected continuously from June 2016 through October 2017 over a 1.5 year period. Two BB seasons are contrasted with the near pristine background conditions during the campaign from the ARM Aerosol Mobile Facility 1 (AMF1) and Mobile Aerosol Observing System (MAOS). Numerous direct in situ aerosol and trace gas measurements are presented, e.g. black carbon (BC), carbon monoxide (CO), PM1 and PM10 aerosol absorption and scattering, submicron non-refractory chemical composition (Organics, Sulfate, Nitrate, Ammonium, Chloride), etc. Aerosol and trace gas signatures are investigated along with backtrajectories to identify sources. Carbonaceous aerosols emitted with gas-phase CO are used to determine particulate emission ratios along with intrinsic and extrinsic aerosol properties. BC mass concentrations reach 1 µg m-3 during multiday plumes and exceed 25% of the total aerosol submicron mass concentration. Organic Aerosol (OA) to BC Ratios of 2.4 in the plume are much higher than previously

  4. Background enhancement in breast MR: Correlation with breast density in mammography and background echotexture in ultrasound

    International Nuclear Information System (INIS)

    Ko, Eun Sook; Lee, Byung Hee; Choi, Hye Young; Kim, Rock Bum; Noh, Woo-Chul

    2011-01-01

    Objective: This study aimed to determine whether background enhancement on MR was related to mammographic breast density or ultrasonographic background echotexture in premenopausal and postmenopausal women. Materials and methods: We studied 142 patients (79 premenopausal, 63 postmenopausal) who underwent mammography, ultrasonography, and breast MR. We reviewed the mammography for overall breast density of the contralateral normal breast according to the four-point scale of the BI-RADS classification. Ultrasound findings were classified as homogeneous or heterogeneous background echotexture according to the BI-RADS lexicon. We rated background enhancement on a contralateral breast MR into four categories based on subtraction images: absent, mild, moderate, and marked. All imaging findings were interpreted independently by two readers without knowledge of menstrual status, imaging findings of other modalities. Results: There were significant differences between the premenopausal and postmenopausal group in distribution of mammographic breast density, ultrasonographic background echotexture, and degree of background enhancement. Regarding the relationship between mammographic density and background enhancement, there was no significant correlation. There was significant relationship between ultrasonographic background echotexture and background enhancement in both premenopausal and postmenopausal groups. Conclusion: There is a significant correlation between ultrasonographic background echotexture and background enhancement in MR regardless of menopausal status. Interpreting breast MR, or scheduling for breast MR of women showing heterogeneous background echotexture needs more caution.

  5. Identification of backgrounds in the EDELWEISS-I dark matter search experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fiorucci, S. [CEA, Centre d' Etudes Nucleaires de Saclay, DSM/DAPNIA, 91191 Gif-sur-Yvette Cedex (France); Benoit, A. [Centre de Recherche sur les Tres Basses Temperatures, SPM-CNRS, BP 166, 38042 Grenoble (France); Berge, L. [Centre de Spectroscopie Nucleaire et de Spectroscopie de Masse, UMR8609 IN2P3-CNRS, Univ. Paris Sud, bat 108, 91405 Orsay Campus (France)] (and others)

    2007-05-15

    This paper presents our interpretation and understanding of the different backgrounds in the EDELWEISS-I data sets. We analyze in detail the several populations observed, which include gammas, alphas, neutrons, thermal sensor events and surface events, and try to combine all data sets to provide a coherent picture of the nature and localization of the background sources. In light of this interpretation, we draw conclusions regarding the background suppression scheme for the EDELWEISS-II phase. (authors)

  6. Identification of backgrounds in the EDELWEISS-I dark matter search experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fiorucci, S. [CEA, Centre d' Etudes Nucleaires de Saclay, DSM/DAPNIA, 91191 Gif-sur-Yvette Cedex (France); Benoit, A. [Centre de Recherche sur les Tres Basses Temperatures, SPM-CNRS, BP 166, 38042 Grenoble (France); Berge, L. [Centre de Spectroscopie Nucleaire et de Spectroscopie de Masse, UMR 8609 IN2P3-CNRS, Univ. Paris Sud, bat 108, 91405 Orsay Campus (France)] (and others)

    2006-10-15

    This paper presents our interpretation and understanding of the different backgrounds in the EDELWEISS-I data sets. We analyze in detail the several populations observed, which include gammas, alphas, neutrons, thermal sensor events and surface events, and try to combine all data sets to provide a coherent picture of the nature and localisation of the background sources. In light of this interpretation, we draw conclusions regarding the background suppression scheme for the EDELWEISS-II phase. (authors)

  7. Background radiation in the Sydney metropolitan area scientific reality and public perception

    International Nuclear Information System (INIS)

    Kemeny, L.G.

    1988-01-01

    Very little information if any, is available to the public about the ubiquitous nature of low-level background radiation -both from terrestrial and cosmic sources - in our highly urbanised or predominantly agrarnian societies. Public perception has naively accepted that the combustion of precious oxygen by air breathing engines is both natural and societally acceptable. Little thought has been given to the fact that on the one planet known to be able to sustain life based on oxygen, this is a recipe for disaster. On the other hand, since the evolution or creation of our universe, billions of tonnes of radioactive material within the crust of planet earth together with radiation from the thermonuclear powers station of the solar system, the sun, have sustained life, assisted in its evolution and, through photosynthesis and energy deposition, have ensured its propagation. In this on-going student project, employing wide-band, sensitive scintillation radiation detectors, careful statistical analysis and an understanding of the physics of radium-uranium decay chain and the production of radon gas and its daughter products, fluctuation in the radiation fields of large cities is clearly demonstrated. The work is usually carried out by the author and his final year thesis and students have great educational value for the public, civic authorities, school teachers, the media and political decision makers

  8. Manual for the Jet Event and Background Simulation Library

    Energy Technology Data Exchange (ETDEWEB)

    Heinz, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soltz, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Angerami, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-11

    Jets are the collimated streams of particles resulting from hard scattering in the initial state of high-energy collisions. In heavy-ion collisions, jets interact with the quark-gluon plasma (QGP) before freezeout, providing a probe into the internal structure and properties of the QGP. In order to study jets, background must be subtracted from the measured event, potentially introducing a bias. We aim to understand and quantify this subtraction bias. PYTHIA, a library to simulate pure jet events, is used to simulate a model for a signature with one pure jet (a photon) and one quenched jet, where all quenched particle momenta are reduced by a user-de ned constant fraction. Background for the event is simulated using multiplicity values generated by the TRENTO initial state model of heavy-ion collisions fed into a thermal model consisting of a 3-dimensional Boltzmann distribution for particle types and momenta. Data from the simulated events is used to train a statistical model, which computes a posterior distribution of the quench factor for a data set. The model was tested rst on pure jet events and then on full events including the background. This model will allow for a quantitative determination of biases induced by various methods of background subtraction.

  9. Norwegian Natural Gas. Liberalization of the European Gas Market

    International Nuclear Information System (INIS)

    Austvik, Ole Gunnar

    2003-01-01

    regulatory regimes. It is shown how multipart tariffs may give the best ''second best'' results, but that first best result may never be achieved. The liberalization of the European gas market is not an isolated phenomenon. In the OECD countries, a large number of sectors have been liberalized over the last couple of decades. Chapter 9 discusses the changes in the North American gas markets (USA and Canada) and in Great Britain, and the relevance these experiences may have for the understanding of the European market. Chapter 10 discusses the role of natural gas in international affairs. Particular focus is put on the US embargo of Soviet gas in 1982. Chapter 11 discusses consuming countries supply security for natural gas, natural gas as the environment's best friend and the use of Strategic Gas Reserves (SGRs) to mitigate a crisis, in the same way as the Strategic Petroleum Reserves (SPRs) is assumed to do in the oil market. Based on these deliberations, Chapter 12 focuses on consequences of a more liberal European gas market for important variables for Norway as an exporter. In particular the effects on prices and taxes, contractual forms and modulation, existing and new long-term contracts, security of supply and environmental concerns are discussed. The impact on the formulation of a Norwegian gas strategy is discussed in Chapter 13. This applies to the organization of production, transportation and sale of natural gas. It also applies to energy related policies of the EU and of EU countries and strategies of other natural gas exporters, like Russia. Some implications of foreign and security policy character are discussed

  10. 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.

  11. The spinorial geometry of supersymmetric backgrounds

    International Nuclear Information System (INIS)

    Gillard, J; Gran, U; Papadopoulos, G

    2005-01-01

    We propose a new method to solve the Killing spinor equations of 11-dimensional supergravity based on a description of spinors in terms of forms and on the Spin(1, 10) gauge symmetry of the supercovariant derivative. We give the canonical form of Killing spinors for backgrounds preserving two supersymmetries, N = 2, provided that one of the spinors represents the orbit of Spin(1, 10) with stability subgroup SU(5). We directly solve the Killing spinor equations of N = 1 and some N = 2, N = 3 and N = 4 backgrounds. In the N = 2 case, we investigate backgrounds with SU(5) and SU(4) invariant Killing spinors and compute the associated spacetime forms. We find that N = 2 backgrounds with SU(5) invariant Killing spinors admit a timelike Killing vector and that the space transverse to the orbits of this vector field is a Hermitian manifold with an SU(5)-structure. Furthermore, N = 2 backgrounds with SU(4) invariant Killing spinors admit two Killing vectors, one timelike and one spacelike. The space transverse to the orbits of the former is an almost Hermitian manifold with an SU(4)-structure. The spacelike Killing vector field leaves the almost complex structure invariant. We explore the canonical form of Killing spinors for backgrounds preserving more than two supersymmetries, N > 2. We investigate a class of N = 3 and N = 4 backgrounds with SU(4) invariant spinors. We find that in both cases the space transverse to a timelike vector field is a Hermitian manifold equipped with an SU(4)-structure and admits two holomorphic Killing vector fields. We also present an application to M-theory Calabi-Yau compactifications with fluxes to one dimension

  12. The spinorial geometry of supersymmetric backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Gillard, J; Gran, U; Papadopoulos, G [Department of Mathematics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

    2005-03-21

    We propose a new method to solve the Killing spinor equations of 11-dimensional supergravity based on a description of spinors in terms of forms and on the Spin(1, 10) gauge symmetry of the supercovariant derivative. We give the canonical form of Killing spinors for backgrounds preserving two supersymmetries, N = 2, provided that one of the spinors represents the orbit of Spin(1, 10) with stability subgroup SU(5). We directly solve the Killing spinor equations of N = 1 and some N = 2, N = 3 and N = 4 backgrounds. In the N = 2 case, we investigate backgrounds with SU(5) and SU(4) invariant Killing spinors and compute the associated spacetime forms. We find that N = 2 backgrounds with SU(5) invariant Killing spinors admit a timelike Killing vector and that the space transverse to the orbits of this vector field is a Hermitian manifold with an SU(5)-structure. Furthermore, N = 2 backgrounds with SU(4) invariant Killing spinors admit two Killing vectors, one timelike and one spacelike. The space transverse to the orbits of the former is an almost Hermitian manifold with an SU(4)-structure. The spacelike Killing vector field leaves the almost complex structure invariant. We explore the canonical form of Killing spinors for backgrounds preserving more than two supersymmetries, N > 2. We investigate a class of N = 3 and N = 4 backgrounds with SU(4) invariant spinors. We find that in both cases the space transverse to a timelike vector field is a Hermitian manifold equipped with an SU(4)-structure and admits two holomorphic Killing vector fields. We also present an application to M-theory Calabi-Yau compactifications with fluxes to one dimension.

  13. Structural change in Europe's gas markets: three scenarios for the development of the European gas market to 2020

    International Nuclear Information System (INIS)

    Ellis, A.; Bowitz, E.; Roland, K.

    2000-01-01

    Against the background of the European Union's Gas Directive, and the emergence of new players and markets in Europe's gas sector, this paper explores how company actions could shape the future for the gas industry. Starting with an examination of company strategies this paper develops three scenarios for the future: a 'Gradual Transformation' scenario where a single European gas market develops that is essentially oligopolistic in nature; a 'Vertical Integration' scenario, where upstream and downstream gas companies merge to form a vertically integrated gas supplier; and a 'Pull the Plug' scenario, where the current market structure decomposes into a competitive market. These scenarios are examined in terms of their impact on gas prices, demand and the distribution of gas rent along the supply chain. The paper highlights the fact that the EU's gas Directive is not sufficient for the introduction of competition into Europe's gas markets, but that company actions will be the key determinant, and they may favour alternative market structures. (Author)

  14. Background CH4 and N2O fluxes in low-input short rotation coppice

    Science.gov (United States)

    Görres, Carolyn-Monika; Zenone, Terenzio; Ceulemans, Reinhart

    2016-04-01

    uncovered by analysing the measurements of the AC. The majority of the fluxes captured by the AC ranged between -2 and 2 μmol m-2 h-1 for CH4, and -0.2 and 0.2 μmol m-2 h-1 for N2O, respectively. Understanding the environmental drivers of background CH4 and N2O fluxes is the basis for designing reasonable gap-filling strategies, and thus for a more accurate quantification of the contribution of these gases to the overall greenhouse gas balance of low-input short rotation coppice systems. Additionally, it is also an important contribution to the current debate whether soils can be significant N2O sinks. Funding support: ERC Advanced Grant agreement (# 233366) POPFULL under the EC 7th Framework Program (FP7/2007-2013), Flemish Hercules Foundation as Infrastructure contract # ZW09-06, and the Methusalem Program of the Flemish Government.

  15. A preamplifier with reduced background noise

    International Nuclear Information System (INIS)

    Taieb, J.

    1950-01-01

    A description is given of a preamplifier in use with a mass spectrometer for rapid gas mixtures analysis, described in Report CEA-42. The instrument can be employed for amplifying any weak currents from high-impedance sources, in the frequency range 10 to 5000 cycle/sec

  16. Effective water influx control in gas reservoir development: Problems and countermeasures

    Directory of Open Access Journals (Sweden)

    Xi Feng

    2015-03-01

    Full Text Available Because of the diversity of geological characteristics and the complexity of percolation rules, many problems are found ineffective water influx control in gas reservoir development. The problems mainly focus on how to understand water influx rules, to establish appropriate countermeasures, and to ensure the effectiveness of technical measures. It is hard to obtain a complete applicable understanding through the isolated analysis of an individual gas reservoir due to many factors such as actual gas reservoir development phase, research work, pertinence and timeliness of measures, and so on. Over the past four decades, the exploration, practicing and tracking research have been conducted on water control in gas reservoir development in the Sichuan Basin, and a series of comprehensive water control technologies were developed integrating advanced concepts, successful experiences, specific theories and mature technologies. Though the development of most water-drive gas reservoirs was significantly improved, water control effects were quite different. Based on this background, from the perspective of the early-phase requirements of water influx control, the influencing factors of a water influx activity, the dynamic analysis method of water influx performance, the optimizing strategy of a water control, and the water control experience of typical gas reservoirs, this paper analyzed the key problems of water control, evaluated the influencing factors of water control effect, explored the practical water control strategies, and proposed that it should be inappropriate to apply the previous water control technological model to actual work but the pertinence should be improved according to actual circumstances. The research results in the paper provide technical reference for the optimization of water-invasion gas reservoir development.

  17. Investigating the Methane Footprint of Compressed Natural Gas Stations in the Los Angeles Basin

    Science.gov (United States)

    Carranza, V.; Hopkins, F. M.; Randerson, J. T.; Bush, S.; Ehleringer, J. R.; Miu, J.

    2013-12-01

    In recent years, natural gas has taken on a larger role in the United States' discourse on energy policy because it is seen as a fuel that can alleviate the country's dependence on foreign energy while simultaneously reducing greenhouse gas emissions. To this end, the State of California promotes the use of vehicles fueled by compressed natural gas (CNG). However, the implications of increased CNG vehicles for greenhouse gas emission reduction are not fully understood. Specifically, methane (CH4) leakages from natural gas infrastructure could make the switch from conventional to CNG vehicles a source of CH4 to the atmosphere, and negate the greenhouse-gas reduction benefit of this policy. The goal of our research is to provide an analysis of potential CH4 leakages from thirteen CNG filling stations in Orange County, California. To improve our understanding of CH4 leakages, we used a mobile laboratory, which is a Ford Transit van equipped with cavity-ring down Picarro spectrometers, to measure CH4 mixing ratios in these CNG stations. MATLAB and ArcGIS were used to conduct statistical analysis and to construct spatial and temporal maps for each transect. We observed mean levels of excess CH4 (relative to background CH4 mixing ratios) ranging from 60 to 1700 ppb at the CNG stations we sampled. Repeated sampling of CNG stations revealed higher levels of excess CH4 during the daytime compared to the nighttime. From our observations, CNG storage tanks and pumps have approximately the same CH4 leakage levels. By improving our understanding of the spatial and temporal patterns of CH4 emissions from CNG stations, our research can provide valuable information to reduce the climate footprint of the natural gas industry.

  18. Measurements of the cosmic background radiation

    International Nuclear Information System (INIS)

    Weiss, R.

    1980-01-01

    Measurements of the attributes of the 2.7-K microwave background radiation (CBR) are reviewed, with emphasis on the analytic phase of CBR studies. Methods for the direct measurement of the CBR spectrum are discussed. Attention is given to receivers, antennas, absolute receiver calibration, atmospheric emission and absorption, the galactic background contribution, the analysis of LF measurements, and recent HF observations of the CBR spectrum. Measurements of the large-angular-scale intensity distribution of the CBR (the most convincing evidence that the radiation is of cosmological origin) are examined, along with limits on the linear polarization of the CBR. A description is given of the NASA-sponsored Cosmic Background Explorer (COBE) satellite mission. The results of the COBE mission will be a set of sky maps showing, in the wave number range from 1 to 10,000 kaysers, the galactic background radiation due to synchrotron emission from galactic cosmic rays, to diffuse thermal emission from H II regions, and to diffuse thermal emission from interstellar and interplanetary dust, as well as a residue consisting of the CBR and whatever other cosmological background might exist

  19. Broadening and attenuation of UV laser ablation plumes in background gases

    DEFF Research Database (Denmark)

    Amoruso, S.; Toftmann, B.; Schou, Jørgen

    2005-01-01

    The expansion of a laser-induced silver plume in a background gas has been studied in a variety of gases ranging from helium, oxygen and argon to xenon. We have measured the angular distribution of the total deposit of silver on an array of quartz crystal microbalances as well as the time...

  20. Solar system astrophysics background science and the inner solar system

    CERN Document Server

    Milone, Eugene F

    2008-01-01

    Solar System Astrophysics: A Text for the Science of Planetary Systems covers the field of solar system astrophysics beginning with basic tools of spherical astronomy, coordinate frames, and celestial mechanics. Historical introductions precede the development and discussion in most chapters. After a basic treatment of the two- and restricted three-body system motions in Background Science and the Inner Solar System, perturbations are discussed, followed by the Earth's gravitational potential field and its effect on satellite orbits. This is followed by analysis of the Earth-Moon system and the interior planets. In Planetary Atmospheres and the Outer Solar System, the atmospheres chapters include detailed discussions of circulation, applicable also to the subsequent discussion of the gas giants. The giant planets are discussed together, and the thermal excesses of three of them are highlighted. This is followed by chapters on moons and rings, mainly in the context of dynamical stability, comets and meteors, m...

  1. Engaging Canadians: national oil sands dialogues - A background paper

    International Nuclear Information System (INIS)

    Carson, Bruce

    2010-01-01

    It is expected that the world's energy demand will grow significantly between now and the year 2050. Hydrocarbons will have an important role to play in meeting this increasing demand and unconventional sources such as oil sands will become more and more important. The Canadian Association of Petroleum Producers (CAPP) has been engaged in a dialogue process to examine the environmental, economic and social impacts of the oil sands industry and the aim of this background paper is to provide stakeholders with some context. The paper highlights the fact that although the oil sands industry gives rise to environmental issues such as greenhouse gas emissions, air pollutants, land disturbance and water use, the environmental performance of the industry has been improving in recent years thanks to new technologies.

  2. Controlling branching in streamer discharge by laser background ionization

    International Nuclear Information System (INIS)

    Takahashi, E; Kato, S; Furutani, H; Sasaki, A; Kishimoto, Y

    2011-01-01

    Irradiation with a KrF laser controlled the positive streamer branching in atmospheric argon gas. This laser irradiation changed the amount of background ionization before the streamer discharge. Measuring the ionization current allowed us to evaluate the initial electron density formed by the KrF laser. We observed characteristic feather-like branching structure and found that it was only suppressed in the irradiated region. The threshold of ionization density which can influence the branching was evaluated to be 5 x 10 5 cm -3 . The relationship between the size of avalanche head and mean distance between initial electrons explained this suppression behaviour. These experimental results support that the feather-like structure originates from the branching model of Loeb-Meek, a probabilistic merging of individual avalanches.

  3. The BetaCage: Ultrasensitive Screener for Radioactive Backgrounds

    Science.gov (United States)

    Thompson, Michael; BetaCage Collaboration

    2017-09-01

    Rare event searches, such as dark matter detection and neutrinoless double beta decay, require screening of materials for backgrounds such as beta emission and alpha decaying isotopes. The BetaCage is a proposed ultra-sensitive time-projection chamber to screen for alpha-emitting and low energy beta-emitting (10-200 keV) contaminants. The expected sensitivity is 0.1 beta particles (perkeV -m2 - day) and 0.1 alpha particles (perm2 - day) , where the former will be limited by Compton scattering of external photons in the screening samples and the latter is expected to be signal-limited. The prototype BetaCage under commissioning at South Dakota School of Mines & Technology is filled with P10 gas (10% methane, 90% argon) in place of neon and is 40×40×20 cm in size. Details on design, construction and characterization will be presented.

  4. Monte Carlo simulations of low background detectors

    International Nuclear Information System (INIS)

    Miley, H.S.; Brodzinski, R.L.; Hensley, W.K.; Reeves, J.H.

    1995-01-01

    An implementation of the Electron Gamma Shower 4 code (EGS4) has been developed to allow convenient simulation of typical gamma ray measurement systems. Coincidence gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra for the purpose of extremely low-level assay. Monte Carlo calculations of this sort can be extremely successful since low background detectors are usually free of significant contributions from poorly localized radiation sources, such as cosmic muons, secondary cosmic neutrons, and radioactive construction or shielding materials. Previously, validation of this code has been obtained from a series of comparisons between measurements and blind calculations. An example of the application of this code to an exceedingly low background spectrum stripping will be presented. (author) 5 refs.; 3 figs.; 1 tab

  5. Background harmonic superfields in N=2 supergravity

    International Nuclear Information System (INIS)

    Zupnik, B.M.

    1998-01-01

    A modification of the harmonic superfield formalism in D=4, N=2 supergravity using a subsidiary condition of covariance under the background supersymmetry with a central charge (B-covariance) is considered. Conservation of analyticity together with the B-covariance leads to the appearance of linear gravitational superfields. Analytic prepotentials arise in a decomposition of the background linear superfields in terms of spinor coordinates and transform in a nonstandard way under the background supersymmetry. The linear gravitational superfields can be written via spinor derivatives of nonanalytic spinor prepotentials. The perturbative expansion of supergravity action in terms of the B-covariant superfields and the corresponding version of the differential-geometric formalism are considered. We discuss the dual harmonic representation of the linearized extended supergravity, which corresponds to the dynamical condition of Grassmann analyticity

  6. In-beam background suppression shield

    DEFF Research Database (Denmark)

    Santoro, V.; Cai, Xiao Xiao; DiJulio, D. D.

    2015-01-01

    The long (3 ms) 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's capabilities will be limited by its 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....

  7. Background Model for the Majorana Demonstrator

    Science.gov (United States)

    Cuesta, C.; Abgrall, N.; 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.; 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.

    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.

  8. Background compensation for a radiation level monitor

    Science.gov (United States)

    Keefe, D.J.

    1975-12-01

    Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

  9. Non-perturbative background field calculations

    International Nuclear Information System (INIS)

    Stephens, C.R.; Department of Physics, University of Utah, Salt Lake City, Utah 84112)

    1988-01-01

    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

  10. Origin of the diffuse background gamma radiation

    International Nuclear Information System (INIS)

    Stecker, F.W.; Puget, J.L.

    1974-05-01

    Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy formation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given. (U.S.)

  11. Cosmic microwave background distortions at high frequencies

    International Nuclear Information System (INIS)

    Peter, W.; Peratt, A.L.

    1988-01-01

    The authors analyze the deviation of the cosmic background radiation spectrum from the 2.76+-0.02 0 Κ blackbody curve. If the cosmic background radiation is due to absorption and re-emission of synchrotron radiation from galactic-width current filaments, higher-order synchrotron modes are less thermalized than lower-order modes, causing a distortion of the blackbody curve at higher frequencies. New observations of the microwave background spectrum at short wavelengths should provide an indication of the number of synchrotron modes thermalized in this process. The deviation of the spectrum from that of a perfect blackbody can thus be correlated with astronomical observations such as filament temperatures and electron energies. The results are discussed and compared with the theoretical predictions of other models which assume the presence of intergalactic superconducting cosmic strings

  12. Non-perturbative background field calculations

    Science.gov (United States)

    Stephens, C. R.

    1988-01-01

    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.

  13. Greenhouse gas strategy

    International Nuclear Information System (INIS)

    2001-03-01

    Because the overall effects of climate change will likely be more pronounced in the North than in other parts of the country, the Government of the Northwest Territories considers it imperative to support global and local actions to reduce greenhouse gas emissions. Government support is manifested through a coordinating role played by senior government representatives in the development of the NWT Greenhouse Gas Strategy, and by participation on a multi-party working committee to identify and coordinate northern actions and to contribute a northern perspective to Canada's National Climate Change Implementation Strategy. This document outlines the NWT Government's goals and objectives regarding greenhouse gas emission reduction actions. These will include efforts to enhance awareness and understanding; demonstrate leadership by putting the Government's own house in order; encouraging action across sectors; promote technology development and innovation; invest in knowledge and building the foundation for informed future decisions. The strategy also outlines the challenges peculiar to the NWT, such as the high per person carbon dioxide emissions compared to the national average (30 tonnes per person per year as opposed to the national average of 21 tonnes per person per year) and the increasing economic activity in the Territories, most of which are resource-based and therefore energy-intensive. Appendices which form part of the greenhouse gas strategy document, provide details of the potential climate change impact in the NWT, a detailed explanation of the proposed measures, an emission forecast to 2004 from industrial processes, fuel combustion and incineration, and a statement of the official position of the Government of the NWT on climate change

  14. Analysis of background components in Ge-spectrometry and their influence on detection limits

    Energy Technology Data Exchange (ETDEWEB)

    Heusser, G [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    1997-03-01

    In low radioactivity measurements the system own background of the spectrometer is, besides the counting efficiency, the limiting factor for the achievable sensitivity. Since the latter is mostly fixed, background reduction is the only way to gain sensitivity, although it is inversely proportional only to the square root of the background rate but directly proportional to the counting efficiency. A thorough understanding of the background sources and their quantitative contribution helps to choose the most adequate suppression method in order to reach a certain required level of detection limit. For Ge-spectrometry the background can be reduced by 5 to 6 orders of magnitude compared to the unshielded case applying state-of-the-art techniques. This reduction factor holds for the continuous background spectrum as well as for the line background as demonstrated for a Ge detector of the Heidelberg-Moscow double beta decay experiment. (orig./DG)

  15. Gas, gas, gas... discoveries and developments booming worldwide

    International Nuclear Information System (INIS)

    Maxwell, F.

    2000-01-01

    Deep water exploration is yielding more than billion barrel oil fields. Unocal's 3 May discovery of 2-3 Tcf of gas in its Kutei block of Indonesia marks the first major discovery of natural gas in the deep water frontier: Wildcats Gula and Gada were drilled in over 1800 m of water as part of an aggressive search for gas instigated by Unocal last year. The author makes a survey of gas exploration and development throughout the world. (author)

  16. Background simulation for the GENIUS project

    International Nuclear Information System (INIS)

    Ponkratenko, O.A.; Tretyak, V.I.; Zdesenko, Yu.G.

    1999-01-01

    The background simulations for the GENIUS experiment were performed with the help of GEANT 3.21 package and event generator DECAY 4.Contributions from the cosmogenic activity produced in the Ge detectors and from its radioactive impurities as well as from contamination of the liquid nitrogen and other materials were calculated.External gamma and neutron background were taking into consideration also.The results of calculations evidently show feasibility of the GENIUS project,which can substantially promote development of modern astroparticle physics

  17. Optimization of the ECT background coil

    International Nuclear Information System (INIS)

    Ballou, J.K.; Luton, J.N.

    1975-01-01

    This study was begun to optimize the Eccentric Coil Test (ECT) background coil. In the course of this work a general optimization code was obtained, tested, and applied to the ECT problem. So far this code has proven to be very satisfactory. The results obtained with this code and earlier codes have illustrated the parametric behavior of such a coil system and that the optimum for this type system is broad. This study also shows that a background coil with a winding current density of less than 3000 A/cm 2 is not feasible for the ECT models presented in this paper

  18. Elastic lattice in an incommensurate background

    International Nuclear Information System (INIS)

    Dickman, R.; Chudnovsky, E.M.

    1995-01-01

    We study a harmonic triangular lattice, which relaxes in the presence of an incommensurate short-wavelength potential. Monte Carlo simulations reveal that the elastic lattice exhibits only short-ranged translational correlations, despite the absence of defects in either lattice. Extended orientational order, however, persists in the presence of the background. Translational correlation lengths exhibit approximate power-law dependence upon cooling rate and background strength. Our results may be relevant to Wigner crystals, atomic monolayers on crystals surfaces, and flux-line and magnetic bubble lattices

  19. Cognitive psychology and depth psychology backgrounds

    International Nuclear Information System (INIS)

    Fritzsche, A.F.

    1986-01-01

    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) [de

  20. Conserved quantities in background independent theories

    Energy Technology Data Exchange (ETDEWEB)

    Markopoulou, Fotini [Perimeter Institute for Theoretical Physics, 35 King Street North, Waterloo, Ontario N2J 2W9 (Canada); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2007-05-15

    We discuss the difficulties that background independent theories based on quantum geometry encounter in deriving general relativity as the low energy limit. We follow a geometrogenesis scenario of a phase transition from a pre-geometric theory to a geometric phase which suggests that a first step towards the low energy limit is searching for the effective collective excitations that will characterize it. Using the correspondence between the pre-geometric background independent theory and a quantum information processor, we are able to use the method of noiseless subsystems to extract such coherent collective excitations. We illustrate this in the case of locally evolving graphs.

  1. Fermionic bound states in distinct kinklike backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil); Mohammadi, A. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, Paraiba (Brazil)

    2017-04-15

    This work deals with fermions in the background of distinct localized structures in the two-dimensional spacetime. Although the structures have a similar topological character, which is responsible for the appearance of fractionally charged excitations, we want to investigate how the geometric deformations that appear in the localized structures contribute to the change in the physical properties of the fermionic bound states. We investigate the two-kink and compact kinklike backgrounds, and we consider two distinct boson-fermion interactions, one motivated by supersymmetry and the other described by the standard Yukawa coupling. (orig.)

  2. A low background pulsed neutron polyenergetic beam

    International Nuclear Information System (INIS)

    Adib, M.; Abdelkawy, A.; Habib, N.; abuelela, M.; Wahba, M.; kilany, M.; Kalebebin, S.M.

    1992-01-01

    A low background pulsed neutron polyenergetic thermal beam at ET-R R-1 is produced by a rotor and rotating collimator suspended in magnetic fields. Each of them is mounted on its mobile platform and whose centres are 66 cm apart, rotating synchronously at speeds up to 16000 rpm. It was found that the neutron burst produced by the rotor with almost 100% transmission passes through the collimator, when the rotation phase between them is 28.8 degree Moreover the background level achieved at the detector position is low, constant and free from peaks due to gamma rays and fast neutrons accompanying the reactor thermal beam.3 fig

  3. Noise correlations in cosmic microwave background experiments

    Science.gov (United States)

    Dodelson, Scott; Kosowsky, Arthur; Myers, Steven T.

    1995-01-01

    Many analysis of microwave background experiments neglect the correlation of noise in different frequency of polarization channels. We show that these correlations, should they be present, can lead to serve misinterpretation of an experiment. In particular, correlated noise arising from either electronics or atmosphere may mimic a cosmic signal. We quantify how the likelihood function for a given experiment varies with noise correlation, using both simple analytic models and actual data. For a typical microwave background anisotropy experiment, noise correlations at the level of 1% of the overall noise can seriously reduce the significance of a given detection.

  4. 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.

  5. Cosmic microwave background at its twentieth anniversary

    International Nuclear Information System (INIS)

    Partridge, R.B.

    1986-01-01

    The role of cosmic microwave background radiation in cosmology is examined. The thermal spectrum, the large entropy in the universe, the large-scale isotropy of the radiation, and the small-scale isotropy or homogeneity of the radiation are analyzed in order to describe the properties of the universe. It is observed that the microwave background spectrum is thermal over a wide range, there is a significant detectable dipole anisotropy in the radiation, but no quadrupole anisotropy, and there is a high deree of radiation isotropy on angular scales between 1-5 degrees. 62 references

  6. Natural background radiation and oncologic disease incidence

    International Nuclear Information System (INIS)

    Burenin, P.I.

    1982-01-01

    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

  7. ALFA detector, Background removal and analysis for elastic events

    CERN Document Server

    Belaloui, Nazim

    2017-01-01

    I worked on the ALFA project, which has the aim to measure the total cross section in PP collisions as a function of t, the momentum transfer by measuring the scattering angle of the protons. This measurement is done for all available energies; so far 7, 8 and 13 TeV. There are many analysis steps and we have focused on enhancing the signal-to-noise ratio. First of all I tried to be more familiar with ROOT, worked on understanding the code used to access to the data, plotting histograms, then cutting-off background.

  8. Ecological audits under EC regulations: background and impact in practice

    International Nuclear Information System (INIS)

    Walther, T.

    1995-01-01

    There are publications discussing the practical aspects of the implementation of the EC Directive on ecological audits, but little has been published yet on the theoretical background of the directive. The contribution in hand is intended to elucidate the theoretical basis of this instrument in the context of the system of law, explains the term of ''sustainable development'' as a key term, and reveals problems encountered in the evaluation of environmental performance. This information will contribute to a better understanding of the meaning and purposes of the EC Directive, and will thus point out ways and means for direct implementation. (orig.) [de

  9. Dangerous gas detection based on infrared video

    Science.gov (United States)

    Ding, Kang; Hong, Hanyu; Huang, Likun

    2018-03-01

    As the gas leak infrared imaging detection technology has significant advantages of high efficiency and remote imaging detection, in order to enhance the detail perception of observers and equivalently improve the detection limit, we propose a new type of gas leak infrared image detection method, which combines background difference methods and multi-frame interval difference method. Compared to the traditional frame methods, the multi-frame interval difference method we proposed can extract a more complete target image. By fusing the background difference image and the multi-frame interval difference image, we can accumulate the information of infrared target image of the gas leak in many aspect. The experiment demonstrate that the completeness of the gas leakage trace information is enhanced significantly, and the real-time detection effect can be achieved.

  10. British Gas plans global gas unit expansion

    International Nuclear Information System (INIS)

    Vielvoye, R.

    1991-01-01

    This paper reports on developing a global gas business, a British Gas plc's strategy for evolving a state owned U.K. gas company to a privatized worldwide oil and gas giant. By 2000, BG's global gas business is expected to provide 20% of its revenues, compared with 40% each from its exploration and production operations and its U.K. gas business. The global gas unit (GGU) plans to meet its targets mainly through acquiring holdings in gas transmission and distribution companies around the world. In the 12 months since GGU was established, it has made two such major acquisitions in this area. BG acquired Consumers Gas Co., Ltd., Ontario, Canada's biggest natural gas distribution company, for $943.5 million. It also took a 10% stake in Catalana de Gas SA, Barcelona, the largest privately owned gas utility in Spain and in terms of number of customers, the fourth largest in western Europe. BG also is targeting additional revenues from developing gas fired cogeneration systems in developing countries with gas reserves but no established transmission and distribution systems

  11. Influence of Background H2O on the Collision-Induced Dissociation Products Generated from [UO2NO3]+

    Science.gov (United States)

    Van Stipdonk, Michael J.; Iacovino, Anna; Tatosian, Irena

    2018-04-01

    Developing a comprehensive understanding of the reactivity of uranium-containing species remains an important goal in areas ranging from the development of nuclear fuel processing methods to studies of the migration and fate of the element in the environment. Electrospray ionization (ESI) is an effective way to generate gas-phase complexes containing uranium for subsequent studies of intrinsic structure and reactivity. Recent experiments by our group have demonstrated that the relatively low levels of residual H2O in a 2-D, linear ion trap (LIT) make it possible to examine fragmentation pathways and reactions not observed in earlier studies conducted with 3-D ion traps (Van Stipdonk et al. J. Am. Soc. Mass Spectrom. 14, 1205-1214, 2003). In the present study, we revisited the dissociation of complexes composed of uranyl nitrate cation [UVIO2(NO3)]+ coordinated by alcohol ligands (methanol and ethanol) using the 2-D LIT. With relatively low levels of background H2O, collision-induced dissociation (CID) of [UVIO2(NO3)]+ primarily creates [UO2(O2)]+ by the ejection of NO. However, CID (using He as collision gas) of [UVIO2(NO3)]+ creates [UO2(H2O)]+ and UO2 + when the 2-D LIT is used with higher levels of background H2O. Based on the results presented here, we propose that product ion spectrum in the previous experiments was the result of a two-step process: initial formation of [UVIO2(O2)]+ followed by rapid exchange of O2 for H2O by ion-molecule reaction. Our experiments illustrate the impact of residual H2O in ion trap instruments on the product ions generated by CID and provide a more accurate description of the intrinsic dissociation pathway for [UVIO2(NO3)]+. [Figure not available: see fulltext.

  12. Jordan: Background and U.S. Relations

    Science.gov (United States)

    2011-04-21

    gas taxes. Subsidies for sugar and rice also were increased and public salaries have been raised. The full impact these measures will have on Jordan’s...demonstrations, and one youth leader said that “We believe these changes are only cosmetic and don’t address the core issues that need to be implemented...Jordanians to boycott contacts with Israel, and activists among them have compiled “ black lists” of Jordanian individuals and companies that deal with

  13. Does Social Background Influence Political Science Grades?

    Science.gov (United States)

    Tiruneh, Gizachew

    2013-01-01

    This paper tests a hypothesized linear relationship between social background and final grades in several political science courses that I taught at the University of Central Arkansas. I employ a cross-sectional research design and ordinary least square (OLS) estimators to test the foregoing hypothesis. Relying on a sample of up to 204…

  14. Egypt: Background and U.S. Relations

    Science.gov (United States)

    2013-06-27

    right to govern; the more the Brotherhood charges ahead, the more it confirms the others’ belief of its monopolistic designs over power. Even if...appropriate market -reform and economic growth activities.” Egypt: Background and U.S. Relations Congressional Research Service 18 according to the State

  15. Natural background approach to setting radiation standards

    International Nuclear Information System (INIS)

    Adler, H.I.; Federow, H.; Weinberg, A.M.

    1979-01-01

    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

  16. 20 CFR 410.700 - Background.

    Science.gov (United States)

    2010-04-01

    ... LUNG BENEFITS (1969- ) Rules for the Review of Denied and Pending Claims Under the Black Lung Benefits Reform Act (BLBRA) of 1977 § 410.700 Background. (a) The Black Lung Benefits Reform Act of 1977 broadens... establish entitlement to black lung benefits. Section 435 of the Black Lung Benefits Reform Act of 1977...

  17. The projected background for the CUORE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Alduino, C.; Avignone, F.T.; Chott, N.; Creswick, R.J.; Rosenfeld, C.; Wilson, J. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Alfonso, K.; Hickerson, K.P.; Huang, H.Z.; Sakai, M.; Schmidt, J.; Trentalange, S.; Zhu, B.X. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Artusa, D.R.; Rusconi, C. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Azzolini, O.; Camacho, A.; Keppel, G.; Palmieri, V.; Pira, C. [INFN-Laboratori Nazionali di Legnaro, Padua (Italy); Banks, T.I.; Drobizhev, A.; Freedman, S.J.; Hennings-Yeomans, R.; Kolomensky, Yu.G.; Wagaarachchi, S.L. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Bari, G.; Deninno, M.M. [INFN-Sezione di Bologna, Bologna (Italy); Beeman, J.W. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); Bellini, F.; Cosmelli, C.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Benato, G.; Singh, V. [University of California, Department of Physics, Berkeley, CA (United States); Bersani, A.; Caminata, A. [INFN-Sezione di Genova, Genoa (Italy); Biassoni, M.; Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Fiorini, E.; Gironi, L.; Gotti, C.; Maino, M.; Nastasi, M.; Nucciotti, A.; Pavan, M.; Pozzi, S.; Sisti, M.; Terranova, F.; Zanotti, L. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN-Sezione di Milano Bicocca, Milan (Italy); Branca, A.; Taffarello, L. [INFN-Sezione di Padova, Padua (Italy); Bucci, C.; Cappelli, L.; D' Addabbo, A.; Gorla, P.; Pattavina, L.; Pirro, S.; Laubenstein, M. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Canonica, L. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Massachusetts Institute of Technology, Cambridge, MA (United States); Cao, X.G.; Fang, D.Q.; Ma, Y.G.; Wang, H.W.; Zhang, G.Q. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai (China); Carbone, L.; Cremonesi, O.; Ferri, E.; Giachero, A.; Pessina, G.; Previtali, E. [INFN-Sezione di Milano Bicocca, Milan (Italy); Cardani, L.; Casali, N.; Dafinei, I.; Morganti, S.; Mosteiro, P.J.; Pettinacci, V.; Tomei, C.; Vignati, M. [INFN-Sezione di Roma, Rome (Italy); Copello, S.; Di Domizio, S.; Fernandes, G.; Marini, L.; Pallavicini, M. [INFN-Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Cushman, J.S.; Davis, C.J.; Heeger, K.M.; Lim, K.E.; Maruyama, R.H. [Yale University, Department of Physics, New Haven, CT (United States); Dell' Oro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); INFN-Gran Sasso Science Institute, L' Aquila (Italy); Di Vacri, M.L.; Santone, D. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita dell' Aquila, Dipartimento di Scienze Fisiche e Chimiche, L' Aquila (Italy); Franceschi, M.A.; Ligi, C.; Napolitano, T. [INFN-Laboratori Nazionali di Frascati, Rome (Italy); Fujikawa, B.K.; Mei, Y.; Schmidt, B.; Smith, A.R.; Welliver, B. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Giuliani, A.; Novati, V.; Tenconi, M. [Universit Paris-Saclay, CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Orsay (France); Gladstone, L.; Leder, A.; Ouellet, J.L.; Winslow, L.A. [Massachusetts Institute of Technology, Cambridge, MA (United States); Gutierrez, T.D. [California Polytechnic State University, Physics Department, San Luis Obispo, CA (United States); Haller, E.E. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); University of California, Department of Materials Science and Engineering, Berkeley, CA (United States); Han, K. [Shanghai Jiao Tong University, Department of Physics and Astronomy, Shanghai (China); Hansen, E. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States); Kadel, R. [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Martinez, M. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Moggi, N. [INFN-Sezione di Bologna, Bologna (Italy); Alma Mater Studiorum-Universita di Bologna, Dipartimento di Scienze per la Qualita della Vita, Bologna (Italy); Nones, C. [CEA/Saclay, Service de Physique des Particules, Gif-sur-Yvette (France); Norman, E.B.; Wang, B.S. [Lawrence Livermore National Laboratory, Livermore, CA (United States); University of California, Department of Nuclear Engineering, Berkeley, CA (United States); O' Donnell, T. [Virginia Polytechnic Institute and State University, Center for Neutrino Physics, Blacksburg, VA (United States); Pagliarone, C.E. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita degli Studi di Cassino e del Lazio Meridionale, Dipartimento di Ingegneria Civile e Meccanica, Cassino (Italy); Sangiorgio, S.; Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Wise, T. [Yale University, Department of Physics, New Haven, CT (United States); University of Wisconsin, Department of Physics, Madison, WI (United States); Woodcraft, A. [University of Edinburgh, SUPA, Institute for Astronomy, Edinburgh (United Kingdom); Zimmermann, S. [Lawrence Berkeley National Laboratory, Engineering Division, Berkeley, CA (United States); Zucchelli, S. [INFN-Sezione di Bologna, Bologna (Italy); Alma Mater Studiorum-Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy)

    2017-08-15

    The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of {sup 130}Te with an array of 988 TeO{sub 2} bolometers operating at temperatures around 10 mK. The experiment is currently being commissioned in Hall A of Laboratori Nazionali del Gran Sasso, Italy. The goal of CUORE is to reach a 90% C.L. exclusion sensitivity on the {sup 130}Te decay half-life of 9 x 10{sup 25} years after 5 years of data taking. The main issue to be addressed to accomplish this aim is the rate of background events in the region of interest, which must not be higher than 10{sup -2} counts/keV/kg/year. We developed a detailed Monte Carlo simulation, based on results from a campaign of material screening, radioassays, and bolometric measurements, to evaluate the expected background. This was used over the years to guide the construction strategies of the experiment and we use it here to project a background model for CUORE. In this paper we report the results of our study and our expectations for the background rate in the energy region where the peak signature of neutrinoless double beta decay of {sup 130}Te is expected. (orig.)

  18. Bloemfontein's Greek community: historical background, emigration ...

    African Journals Online (AJOL)

    Bloemfontein's Greek community: historical background, emigration and settlement, ca 1885 - ca 1985. ... South African Journal of Cultural History ... In this study a review is provided of the reasons why Greeks settled in Bloemfontein since about 1885, where these Greek immigrants came from, and how they travelled to ...

  19. Racial background and possible relationships between physical ...

    African Journals Online (AJOL)

    The aim of this research was to investigate possible relationships between physical activity and physical fitness of girls between the ages of 13 and 15 years and the role of different racial backgrounds in this relationship. A cross-sectional research design was used to obtain information from 290 girls between the ages of 13 ...

  20. Controllable forms of natural background radiation

    International Nuclear Information System (INIS)

    1988-03-01

    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

  1. 44 CFR 334.3 - Background.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Background. 334.3 Section 334.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND... take into account the need to mobilize the Nation's resources in response to a wide range of crisis or...

  2. ttH multilepton: background estimation

    CERN Document Server

    Angelidakis, Stylianos; The ATLAS collaboration

    2018-01-01

    The slides present the background encountered in the ttH->Multilepton search and describe the data-driven techniques used for the determination of the dominant non-prompt-lepton contamination as well as the contribution of electron charge mis-identification.

  3. Climate change: Scientific background and process

    OpenAIRE

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

    2000-01-01

    The paper gives a brief description of natural and man-made forces behind climate change and outlines climate variations in the past together with a brief synopsis likely future impacts of anthropogenic emissions of greenhouse gases. The paper also gives a briefing on the background, organisation and functioning of the Intergovernmental Panel on Climate Change (IPCC).

  4. On the maximal superalgebras of supersymmetric backgrounds

    International Nuclear Information System (INIS)

    Figueroa-O'Farrill, Jose; Hackett-Jones, Emily; Moutsopoulos, George; Simon, Joan

    2009-01-01

    In this paper we give a precise definition of the notion of a maximal superalgebra of certain types of supersymmetric supergravity backgrounds, including the Freund-Rubin backgrounds, and propose a geometric construction extending the well-known construction of its Killing superalgebra. We determine the structure of maximal Lie superalgebras and show that there is a finite number of isomorphism classes, all related via contractions from an orthosymplectic Lie superalgebra. We use the structure theory to show that maximally supersymmetric waves do not possess such a maximal superalgebra, but that the maximally supersymmetric Freund-Rubin backgrounds do. We perform the explicit geometric construction of the maximal superalgebra of AdS 4 X S 7 and find that it is isomorphic to osp(1|32). We propose an algebraic construction of the maximal superalgebra of any background asymptotic to AdS 4 X S 7 and we test this proposal by computing the maximal superalgebra of the M2-brane in its two maximally supersymmetric limits, finding agreement.

  5. Background reduction in a young interferometer biosensor

    NARCIS (Netherlands)

    Mulder, H. K P; Subramaniam, V.; Kanger, J. S.

    2014-01-01

    Integrated optical Young interferometer (IOYI) biosensors are among the most sensitive label-free biosensors. Detection limits are in the range of 20 fg/mm2. The applicability of these sensors is however strongly hampered by the large background that originates from both bulk refractive index

  6. Probabilistic Model-based Background Subtraction

    DEFF Research Database (Denmark)

    Krüger, Volker; Anderson, Jakob; Prehn, Thomas

    2005-01-01

    is the correlation between pixels. In this paper we introduce a model-based background subtraction approach which facilitates prior knowledge of pixel correlations for clearer and better results. Model knowledge is being learned from good training video data, the data is stored for fast access in a hierarchical...

  7. The projected background for the CUORE experiment

    Science.gov (United States)

    Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Benato, G.; Bersani, A.; Biassoni, M.; Branca, A.; Brofferio, C.; Bucci, C.; Camacho, A.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; D'Addabbo, A.; Dafinei, I.; Davis, C. J.; Dell'Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Leder, A.; Ligi, C.; Lim, K. E.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Napolitano, T.; Nastasi, M.; Nones, C.; Norman, E. B.; Novati, V.; Nucciotti, A.; O'Donnell, T.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sakai, M.; Sangiorgio, S.; Santone, D.; Schmidt, B.; Schmidt, J.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Welliver, B.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.; Laubenstein, M.

    2017-08-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of ^{130}Te with an array of 988 TeO_2 bolometers operating at temperatures around 10 mK. The experiment is currently being commissioned in Hall A of Laboratori Nazionali del Gran Sasso, Italy. The goal of CUORE is to reach a 90% C.L. exclusion sensitivity on the ^{130}Te decay half-life of 9 × 10^{25} years after 5 years of data taking. The main issue to be addressed to accomplish this aim is the rate of background events in the region of interest, which must not be higher than 10^{-2} counts/keV/kg/year. We developed a detailed Monte Carlo simulation, based on results from a campaign of material screening, radioassays, and bolometric measurements, to evaluate the expected background. This was used over the years to guide the construction strategies of the experiment and we use it here to project a background model for CUORE. In this paper we report the results of our study and our expectations for the background rate in the energy region where the peak signature of neutrinoless double beta decay of ^{130}Te is expected.

  8. 42 CFR 81.0 - Background.

    Science.gov (United States)

    2010-10-01

    ... HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND... OCCUPATIONAL ILLNESS COMPENSATION PROGRAM ACT OF 2000 Introduction § 81.0 Background. The Energy Employees Occupational Illness Compensation Program Act (EEOICPA), 42 U.S.C. 7384-7385 [1994, supp. 2001], provides for...

  9. Spectrum of the extragalactic background light

    Energy Technology Data Exchange (ETDEWEB)

    Bruzual A, G [Centro de Investigacion de Astronomia, Merida (Venezuela)

    1981-01-01

    The observed spectrum of the extragalactic background light in the range from ultraviolet to optical wavelengths is compared with a model prediction. The model uses the locally observed luminosity function of galaxies as well as evolutionary models for galaxy spectral energy distributions. The predicition is too faint by a factor of about 10.

  10. 32 CFR 701.40 - Background.

    Science.gov (United States)

    2010-07-01

    ... OFFICIAL RECORDS AVAILABILITY OF DEPARTMENT OF THE NAVY RECORDS AND PUBLICATION OF DEPARTMENT OF THE NAVY DOCUMENTS AFFECTING THE PUBLIC FOIA Fees § 701.40 Background. (a) The DON follows the uniform fee schedule... Freedom of Information Act Fee Schedule and Guidelines. (b) Fees reflect direct costs for search; review...

  11. 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

  12. Dim point target detection against bright background

    Science.gov (United States)

    Zhang, Yao; Zhang, Qiheng; Xu, Zhiyong; Xu, Junping

    2010-05-01

    For target detection within a large-field cluttered background from a long distance, several difficulties, involving low contrast between target and background, little occupancy, illumination ununiformity caused by vignetting of lens, and system noise, make it a challenging problem. The existing approaches to dim target detection can be roughly divided into two categories: detection before tracking (DBT) and tracking before detection (TBD). The DBT-based scheme has been widely used in practical applications due to its simplicity, but it often requires working in the situation with a higher signal-to-noise ratio (SNR). In contrast, the TBD-based methods can provide impressive detection results even in the cases of very low SNR; unfortunately, the large memory requirement and high computational load prevents these methods from real-time tasks. In this paper, we propose a new method for dim target detection. We address this problem by combining the advantages of the DBT-based scheme in computational efficiency and of the TBD-based in detection capability. Our method first predicts the local background, and then employs the energy accumulation and median filter to remove background clutter. The dim target is finally located by double window filtering together with an improved high order correlation which speeds up the convergence. The proposed method is implemented on a hardware platform and performs suitably in outside experiments.

  13. Classification of supersymmetric backgrounds of string theory

    NARCIS (Netherlands)

    Gran, Ulf; Gutowski, Jan; Papadopoulos, George; Roest, Diederik

    2007-01-01

    We review the recent progress made towards the classification of supersymmetric solutions in ten and eleven dimensions with emphasis on those of IIB supergravity. In particular, the spinorial geometry method is outlined and adapted to nearly maximally supersymmetric backgrounds.We then demonstrate

  14. 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)

  15. Separation parameters of gas centrifuges

    International Nuclear Information System (INIS)

    May, W.G.

    1977-01-01

    Early work on development of the gas centrifuge for separation of uranium isotopes has recently been reviewed. Several configurations were investigated. The preferred configuration eventually turned out to be a countercurrent centrifuge. In this form, an internal circulation is set up, and as a consequence, light isotope concentrates at one end of the centrifuge, heavy isotope at the other. In many ways the effect resembles the separation obtained in packed columns in the chemical and petroleum industries. It is the purpose of this paper to develop this analogy between countercurrent gas centrifuges and packed towers and to illustrate its usefulness in understanding the separation process in the centrifuge. 8 figures

  16. The Spanish gas industry

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The spanish gas industry has become one of the major actors in the gas sector of the European Economic Community. This paper pictures the spanish gas industry on the basis of a study by Sedigas, the spanish member of the International Gas Union (IGU). The main subjects described are structure of gas companies, natural gas supply, transport and storage, natural gas distribution networks, statistical data on natural gas consumption, manufactured gas and Liquefied Petroleum Gases (LPG) production-consumption in Spain. 7 figs., 10 tabs

  17. Basics of development of gas hydrate deposits

    Energy Technology Data Exchange (ETDEWEB)

    Makogon, Yuri F.; Holditch, Stephen A.; Makogon, Taras Y.

    2005-07-01

    Natural gas hydrate deposits could possibly be an important energy resource during this century. However, many problems associated with producing these deposits must first be solved. The industry must develop new technologies to produce the gas, to forecast possible tectonic cataclysms in regions of gas hydrate accumulations, and to prevent damage to the environment. These global issues must be addressed by every company or country who wants to produce gas hydrate deposits. Cooperative research between industry and universities can lead to technology breakthroughs in coming years. This paper reviews the Messoyakha field and the Blake Ridge and Nankai areas to explain a methodology for estimating how much gas might be producible from gas hydrate deposits (GHDs) under various conditions. The Messoyakha field is located on land, while the Blake Ridge and Nankai areas are offshore. Messoyakha is the first and the only GHD where gas production from hydrates has reached commercial flow rates. The Blake Ridge GHD has been studied for 20 years and 11 wells have been drilled to collect gas-hydrate samples. The potential resources of gas (gas in place) from Blake Ridge is estimated at 37.7Oe10{sup 12} m{sup 3} (1.330 Tcf) in hydrate form and 19.3Oe10{sup 12}m{sup 3} (681 Bcf) [5] in free gas. To estimate how much of the potential resource can be produced we need a thorough understanding of both the geologic and the thermodynamic characteristics of the formations. (Author)

  18. How unconventional gas prospers without tax incentives

    International Nuclear Information System (INIS)

    Kuuskraa, V.A.; Stevens, S.H.

    1995-01-01

    It was widely believed that the development of unconventional natural gas (coalbed methane, gas shales, and tight gas) would die once US Sec. 29 credits stopped. Quieter voices countered, and hoped, that technology advances would keep these large but difficult to produce gas resources alive and maybe even healthy. Sec. 29 tax credits for new unconventional gas development stopped at the end of 1992. Now, nearly three years later, who was right and what has happened? There is no doubt that Sec. 29 tax credits stimulated the development of coalbed methane, gas shales, and tight gas. What is less known is that the tax credits helped spawn and push into use an entire new set of exploration, completion, and production technologies founded on improved understanding of unconventional gas reservoirs. As set forth below, while the incentives inherent in Sec. 29 provided the spark, it has been the base of science and technology that has maintained the vitality of these gas sources. The paper discusses the current status; resource development; technology; unusual production, proven reserves, and well completions if coalbed methane, gas shales, and tight gas; and international aspects

  19. IIB backgrounds with five-form flux

    International Nuclear Information System (INIS)

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

    2008-01-01

    We investigate all N=2 supersymmetric IIB supergravity backgrounds with non-vanishing five-form flux. The Killing spinors have stability subgroups Spin(7) x R 8 , SU(4) x R 8 and G 2 . In the SU(4) x R 8 case, two different types of geometry arise depending on whether the Killing spinors are generic or pure. In both cases, the backgrounds admit a null Killing vector field which leaves invariant the SU(4) x R 8 structure, and an almost complex structure in the directions transverse to the lightcone. In the generic case, the twist of the vector field is trivial but the almost complex structure is non-integrable, while in the pure case the twist is non-trivial but the almost complex structure is integrable and associated with a relatively balanced Hermitian structure. The G 2 backgrounds admit a time-like Killing vector field and two spacelike closed one-forms, and the seven directions transverse to these admit a co-symplectic G 2 structure. The Spin(7) x R 8 backgrounds are pp-waves propagating in an eight-dimensional manifold with holonomy Spin(7). In addition we show that all the supersymmetric solutions of simple five-dimensional supergravity with a time-like Killing vector field, which include the AdS 5 black holes, lift to SU(4) x R 8 pure Killing spinor IIB backgrounds. We also show that the LLM solution is associated with a co-symplectic co-homogeneity one G 2 manifold which has principal orbit S 3 xS 3

  20. 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.