WorldWideScience

Sample records for vana-hiina veri uhkus

  1. Kired ja mõrvad Vana-Hiina moodi / Ave Randviir

    Index Scriptorium Estoniae

    Randviir, Ave, 1981-

    2006-01-01

    Arvustus: Gulik, Robert van. Hiina järvemõrvad : kohtunik Di lahendab kolm juhtumit : [romaan] / inglise keelest tõlkinud Kersti Unt ; illustreeritud kaheteistkümne hiinapärase graafilise lehega autorilt. [Tallinn] : Tänapäev, 2006. (Kohtunik Di mõrvamüsteerium)

  2. Suure uhkuse aasta / Marko Mihkelson

    Index Scriptorium Estoniae

    Mihkelson, Marko, 1969-

    2004-01-01

    Ilmunud ka: Meie Maa, 6. jaan. 2004, lk. 2; Põhjarannik, 6. jaan. 2004, lk. 2; Severnoje Poberezhje, 6. jaan. 2004, lk. 2; Pärnu Postimees, 7. jaan. 2004, lk. 11; Valgamaalane, 8. jaan. 2004, lk. 2; Nädaline, 8. jaan. 2004, lk. 4; Koit, 10. jaan. 2004, lk. 6; Hiiu Leht, 13. jaan. 2004, lk. 2. Liitumine Euroopa Liidu ja NATO-ga on autori arvates Eesti jaoks suur võit ja väljakutse

  3. Ksenofoobia kui rahvuslik uhkus / Tanel Mazur

    Index Scriptorium Estoniae

    Mazur, Tanel, 1971-

    2008-01-01

    Eestlaste võõrastekartusest. Autori hinnangul oleme olukorras, kus vaid sadakond aastat tagasi ise koloonia staatusest vabanenuna peame hakkama käituma samaväärselt postkoloniaalsete suurriikidega

  4. Raamat sõja seadustest / Linnart Mäll

    Index Scriptorium Estoniae

    Mäll, Linnart

    2001-01-01

    Vana-Hiina sõjateoreetikute Sun Zi ja Sun Bini raamatust: Sun, Zi ; Sun, Bin. Sõja seadused / klassikalisest hiina keelest tõlkinud ja kommenteerinud Märt Läänemets. Tln. : Eesti Keele Sihtasutus, 2001. (Sõjandusvaramu. Klassika)

  5. Very slow neutrons

    International Nuclear Information System (INIS)

    Frank, A.

    1983-01-01

    The history is briefly presented of the research so far of very slow neutrons and their basic properties are explained. The methods are described of obtaining very slow neutrons and the problems of their preservation are discussed. The existence of very slow neutrons makes it possible to perform experiments which may deepen the knowledge of the fundamental properties of neutrons. Their wavelength approximates that of visible radiation. The possibilities and use are discussed of neutron optical systems (neutron microscope) which could be an effective instrument for the study of the detailed arrangement, especially of organic substances. (B.S.)

  6. Very heavy dark Skyrmions

    International Nuclear Information System (INIS)

    Dick, Rainer

    2017-01-01

    A dark sector with a solitonic component provides a means to circumvent the problem of generically low annihilation cross sections of very heavy dark matter particles. At the same time, enhanced annihilation cross sections are necessary for indirect detection of very heavy dark matter components beyond 100 TeV. Non-thermally produced dark matter in this mass range could therefore contribute to the cosmic γ-ray and neutrino flux above 100 TeV, and massive Skyrmions provide an interesting framework for the discussion of these scenarios. Therefore a Higgs portal and a neutrino portal for very heavy Skyrmion dark matter are discussed. The Higgs portal model demonstrates a dark mediator bottleneck, where limitations on particle annihilation cross sections will prevent a signal from the potentially large soliton annihilation cross sections. This problem can be avoided in models where the dark mediator decays. This is illustrated by the neutrino portal for Skyrmion dark matter. (orig.)

  7. Very heavy dark Skyrmions

    Energy Technology Data Exchange (ETDEWEB)

    Dick, Rainer [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, SK (Canada)

    2017-12-15

    A dark sector with a solitonic component provides a means to circumvent the problem of generically low annihilation cross sections of very heavy dark matter particles. At the same time, enhanced annihilation cross sections are necessary for indirect detection of very heavy dark matter components beyond 100 TeV. Non-thermally produced dark matter in this mass range could therefore contribute to the cosmic γ-ray and neutrino flux above 100 TeV, and massive Skyrmions provide an interesting framework for the discussion of these scenarios. Therefore a Higgs portal and a neutrino portal for very heavy Skyrmion dark matter are discussed. The Higgs portal model demonstrates a dark mediator bottleneck, where limitations on particle annihilation cross sections will prevent a signal from the potentially large soliton annihilation cross sections. This problem can be avoided in models where the dark mediator decays. This is illustrated by the neutrino portal for Skyrmion dark matter. (orig.)

  8. Very long baseline interferometry

    International Nuclear Information System (INIS)

    Eckart, A.

    1982-01-01

    In the last few years the resolution of the instruments used in radioastronomy could be enhanced by a factor of 10 000 compared with the human eye. As this method is relatively young and not very well known, the principles of the technique are presented in combination with the most important results. (orig.) [de

  9. Very high energy colliders

    International Nuclear Information System (INIS)

    Richter, B.

    1986-03-01

    The luminosity and energy requirements are considered for both proton colliders and electron-positron colliders. Some of the basic design equations for high energy linear electron colliders are summarized, as well as design constraints. A few examples are given of parameters for very high energy machines. 4 refs., 6 figs

  10. A very special relationship

    International Nuclear Information System (INIS)

    Arnold, L.M.

    1987-01-01

    The book shows why Britain adopted postwar defence policies that entailed nuclear weapon tests, why more than half of these tests were in Australia, where and how they took place, how the two nations cooperated and what was achieved at what cost. The radiation safety standards of the time and of the present day are compared and the safety aspects of the trials are looked at from the contemporary and present day viewpoint. The book covers the five series of trials in Australia and discusses the very special relationship that existed between the United Kingdom and Australia that made them possible. (author)

  11. Very high energy colliders

    International Nuclear Information System (INIS)

    Richter, B.

    1985-05-01

    The conclusions are relatively simple, but represent a considerable challenge to the machine builder. High luminosity is essential. We may in the future discover some new kind of high cross section physics, but all we know now indicates that the luminosity has to increase as the square of the center of mass energy. A reasonable luminosity to scale from for electron machines would be 10 33 cm -2 s -1 at a center of mass energy of 3 TeV. The required emittances in very high energy machines are small. It will be a real challenge to produce these small emittances and to maintain them during acceleration. The small emittances probably make acceleration by laser techniques easier, if such techniques will be practical at all. The beam spot sizes are very small indeed. It will be a challenge to design beam transport systems with the necessary freedom from aberration required for these small spot sizes. It would of course help if the beta functions at the collision points could be reduced. Beam power will be large - to paraphrase the old saying, ''power is money'' - and efficient acceleration systems will be required

  12. Very low mass stars

    International Nuclear Information System (INIS)

    Liebert, J.; Probst, R.G.

    1987-01-01

    This paper discusses several theoretical and observational topics involved in discovering and analyzing very low mass stellar objects below about 0.3 M circle, as well as their likely extension into the substellar range. The authors hereafter refer to these two classes of objects as VLM stars and brown dwarfs, respectively; collectively, they are called VLM objects. The authors outline recent theoretical work on low-mass stellar interiors and atmospheres, the determination of the hydrogen-burning mass limit, important dynamical evidence bearing on the expected numbers of such objects, and the expectations for such objects from star-formation theory. They focus on the properties of substellar objects near the stellar mass limit. Observational techniques used to discover and analyze VLM objects are summarized

  13. Very special relativity.

    Science.gov (United States)

    Cohen, Andrew G; Glashow, Sheldon L

    2006-07-14

    By very special relativity (VSR) we mean descriptions of nature whose space-time symmetries are certain proper subgroups of the Poincaré group. These subgroups contain space-time translations together with at least a two-parameter subgroup of the Lorentz group isomorphic to that generated by K(x) + J(y) and K(y)- J(x). We find that VSR implies special relativity (SR) in the context of local quantum field theory or of conservation. Absent both of these added hypotheses, VSR provides a simulacrum of SR for which most of the consequences of Lorentz invariance remain wholly or essentially intact, and for which many sensitive searches for departures from Lorentz invariance must fail. Several feasible experiments are discussed for which Lorentz-violating effects in VSR may be detectable.

  14. Very low energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Very low energy geothermics correspond to temperatures below 30 C and has been developed to cover heating and cooling needs of recent individual houses or tertiary industries using heat pumps and low depth aquifers (<100 m). Geothermal heat pumps industry has made great strides in European Northern countries, China, Japan and the United States of America. Geothermal heat pumps are less energy consuming than air heat pumps and require less cooling fluid and maintenance. The Aquapac procedure has been developed in France in 1983 by the AFME (French Energy Control Agency), EdF and the BRGM (Geologic and Mining Research Office) to encourage the use of geothermal heat pump for domestic and sanitary water heating and to make a survey of low-depth aquifers in the whole french territory. The decay of energy costs that started in 1986 has led to a loss of interest for the Aquapac procedure, even in the tertiary industries for which the air-conditioning demand is growing up. (J.S.). 1 tab

  15. A very competitive oil

    International Nuclear Information System (INIS)

    Delamarche, Myrtille; Cahuzac, Adrien; Cognasse, Olivier; Dupin, Ludovic; Fleitour, Gaelle; James, Olivier; Stassi, Franck

    2015-01-01

    Drop in oil barrel prices results in 8 to 10 billions in savings for French companies, i.e. as much as the tax credit for competitiveness and employment. This article analyses how the different sectors take benefit of this saving due to lower oil prices. It outlines that this decrease has been very profitable for the refining sector which exhibited historic margins. As far as the chemistry sector is concerned, costs are reduced but profits are less important as this decrease compensates the decrease of the euro with respect to the dollar. The plastic industry does not take profit as it comes at the end of value chain where other actors already took their benefits. Therefore, there is no profit in agriculture as far as plastic products and fertilizers are concerned. On the opposite, the decrease of marine fuel has been profitable to the fishing sector as well as to the sea transport sector. As far as road transport is concerned the fuel price decrease is reflected in resale prices, and the oil price decrease had therefore no impact, or only for few days. It's not the case for air transport where companies took benefit of this decrease. In this respect, a second article outlines that airline companies have learned lessons from previous oil price counter-shock to adapt their strategies. The last article addresses the general situation of industry which exhibits a better financial health, could be boosted by a recovery of consumption. But growth is still to be confirmed by investments. A brief article notices that the profit is less important at the world level, i.e. more important in Europe than in Asia and even more than in Africa

  16. Ida-igatsuse põhjapiir / Raivo Paltser

    Index Scriptorium Estoniae

    Paltser, Raivo

    2006-01-01

    Hiina traditsiooni järgija R. Paltseri nägemus Lääne inimese ihalusest Vana-Hiina kultuuri järele, kung-fust. Toodud mõningaid näiteid Soome ja Hiina mütoloogiat ühendavast fantaasiafilmist "Igavese armastuse sõdalane - Jade Warrior"

  17. Phenomena at very high spins

    International Nuclear Information System (INIS)

    Stephens, F.S.

    1980-03-01

    The present talk has three parts: first, a discussion of current ideas about the physics of very high spin states; second, some comments about noncollective behavior up to the highest spins where it is known, approx. 40 h; and finally, a presentation of the newest method for studying collective behavior up to spins of 60 to 70 h. The intention is that the overview presented in the first part will be sufficiently broad to indicate the relationship of the noncollective and collective behavior discussed in the other parts, and to provide some understanding of the compromise in behavior that seems to occur at the very highest spins. 13 figures

  18. Nothing a very short introduction

    CERN Document Server

    Close, Frank

    2009-01-01

    What is 'nothing'? What remains when you take all the matter away? Can empty space - a void - exist? This Very Short Introduction explores the science and the history of the elusive void: from Aristotle who insisted that the vacuum was impossible, via the theories of Newton and Einstein, to our very latest discoveries and why they can tell us extraordinary things about the cosmos. Frank Close tells the story of how scientists have explored the elusive void, and the rich discoveries that they have made there. He takes the reader on a lively and accessible history through ancient ideas and cultural superstitions to the frontiers of current research

  19. Very Long Instruction Word Processors

    Indian Academy of Sciences (India)

    Explicitly Parallel Instruction Computing (EPIC) is an instruction processing paradigm that has been in the spot- light due to its adoption by the next generation of Intel. Processors starting with the IA-64. The EPIC processing paradigm is an evolution of the Very Long Instruction. Word (VLIW) paradigm. This article gives an ...

  20. Complexity a very short introduction

    CERN Document Server

    Holland, John H

    2014-01-01

    The importance of complexity is well-captured by Hawking's comment: "Complexity is the science of the 21st century". From the movement of flocks of birds to the Internet, environmental sustainability, and market regulation, the study and understanding of complex non-linear systems has become highly influential over the last 30 years. In this Very Short Introduction, one of the leading figures in the field, John Holland, introduces the key elements and conceptual framework of complexity. From complex physical systems such as fluid flow and the difficulties of predicting weather, to complex adaptive systems such as the highly diverse and interdependent ecosystems of rainforests, he combines simple, well-known examples - Adam Smith's pin factory, Darwin's comet orchid, and Simon's 'watchmaker' - with an account of the approaches, involving agents and urn models, taken by complexity theory. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost eve...

  1. Astrophysics at very high energies

    International Nuclear Information System (INIS)

    Aharonian, Felix; Bergstroem, Lars; Dermer, Charles

    2013-01-01

    Presents three complementary lectures on very-high-energy astrophysics given by worldwide leaders in the field. Reviews the recent advances in and prospects of gamma-ray astrophysics and of multi-messenger astronomy. Prepares readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors. With the success of Cherenkov Astronomy and more recently with the launch of NASA's Fermi mission, very-high-energy astrophysics has undergone a revolution in the last years. This book provides three comprehensive and up-to-date reviews of the recent advances in gamma-ray astrophysics and of multi-messenger astronomy. Felix Aharonian and Charles Dermer address our current knowledge on the sources of GeV and TeV photons, gleaned from the precise measurements made by the new instrumentation. Lars Bergstroem presents the challenges and prospects of astro-particle physics with a particular emphasis on the detection of dark matter candidates. The topics covered by the 40th Saas-Fee Course present the capabilities of current instrumentation and the physics at play in sources of very-high-energy radiation to students and researchers alike. This book will encourage and prepare readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors.

  2. Very high-luminosity infrared galaxies - are they very young?

    International Nuclear Information System (INIS)

    Burbidge, G.

    1986-01-01

    It is proposed that most of the very high-luminosity IRAS galaxies, those which emit greater than or equal to 10 to the 12th solar luminosities nearly all in the far infrared out to 100 microns, are very young systems with ages less than or equal to 10 to the 9th years. The luminosity comes largely from stars with masses near 100 solar masses which evolve rapidly, ejecting much of their mass as elements heavier than hydrogen. The gas ejected condenses into dust in circumstellar shells. The prototype star in the Galaxy which shows all of these attributes is Eta Car. It is shown that total masses of order 10 to the 7th-10 to the 8th solar masses condensed into such stars can produce the observed luminosities, and that 10-100 generations of such stars will produce enough dust (about 10 to the 8th solar masses) to explain the observed infrared luminosities. If this hypothesis is correct the composition of gas and dust may well be highly anomalous, and there should be no old stars with ages about 10 to the 10th years present. Initial star formation is probably triggered by interactions with close companion galaxies. 40 references

  3. Relativity a very short introduction

    CERN Document Server

    Stannard, F Russell

    2008-01-01

    Relativity: A Very Short Introduction makes the theory of relativity understandable and accessible. 100 years ago, Einstein's theory of relativity shattered the world of physics. Our comforting Newtonian ideas of space and time were replaced by bizarre and counterintuitive conclusions: if you move at high speed, time slows down, space squashes up and you get heavier; travel fast enough and you could weigh as much as a jumbo jet, be squashed thinner than a CD without feeling a thing - and live forever. And that was just the special theory. With the general theory came even stranger ideas of curved space-time, which changed our understanding of gravity and the cosmos.

  4. Sound a very short introduction

    CERN Document Server

    Goldsmith, Mike

    2015-01-01

    Sound is integral to how we experience the world, in the form of noise as well as music. But what is sound? What is the physical basis of pitch and harmony? And how are sound waves exploited in musical instruments? Sound: A Very Short Introduction looks at the science of sound and the behaviour of sound waves with their different frequencies. It also explores sound in different contexts, covering the audible and inaudible, sound underground and underwater, acoustic and electronic sound, and hearing in humans and animals. It concludes with the problem of sound out of place—noise and its reduction.

  5. Superconductivity a very short introduction

    CERN Document Server

    Blundell, Stephen

    2009-01-01

    Superconductivity is one of the most exciting areas of research in physics today. Outlining the history of its discovery, and the race to understand its many mysterious and counter-intuitive phenomena, this Very Short Introduction explains in accessible terms the theories that have been developed, and how they have influenced other areas of science, including the Higgs boson of particle physics and ideas about the early Universe. It is an engaging and informative accountof a fascinating scientific detective story, and an intelligible insight into some deep and beautiful ideas of physics

  6. Planets a very short introduction

    CERN Document Server

    Rothery, David A

    2010-01-01

    Planets: A Very Short Introduction demonstrates the excitement, uncertainties, and challenges faced by planetary scientists, and provides an overview of our Solar System and its origins, nature, and evolution. Terrestrial planets, giant planets, dwarf planets and various other objects such as satellites (moons), asteroids, trans-Neptunian objects, and exoplanets are discussed. Our knowledge about planets has advanced over the centuries, and has expanded at a rapidly growing rate in recent years. Controversial issues are outlined, such as What qualifies as a planet? What conditions are required for a planetary body to be potentially inhabited by life? Why does Pluto no longer have planet status? And Is there life on other planets?

  7. Galaxies a very short introduction

    CERN Document Server

    Gribbin, John

    2008-01-01

    Galaxies: A Very Short Introduction explores the building blocks of the Universe. Standing like islands in space, each is made up of many hundreds of millions of stars in which the chemical elements are made, around which planets form, and where on at least one of those planets intelligent life has emerged. Our own galaxy, the Milky Way, is just one of several hundred million other galaxies. Yet it was only in the 1920s that we realised that there is more to the Universe. Since then, many exciting discoveries have been made about our own galaxy and about those beyond.

  8. Very high multiplicity hadron processes

    International Nuclear Information System (INIS)

    Mandzhavidze, I.; Sisakyan, A.

    2000-01-01

    The paper contains a description of a first attempt to understand the extremely inelastic high energy hadron collisions, when the multiplicity of produced hadrons considerably exceeds its mean value. Problems with existing model predictions are discussed. The real-time finite-temperature S-matrix theory is built to have a possibility to find model-free predictions. This allows one to include the statistical effects into consideration and build the phenomenology. The questions to experiment are formulated at the very end of the paper

  9. Radioactivity a very short introduction

    CERN Document Server

    Tuniz, Claudio

    2012-01-01

    Radioactivity: A Very Short Introduction explains radioactivity and discusses its fundamental role in nature. Radioactivity remains misunderstood and feared perhaps because nuclear radiation cannot be detected by human senses, and can undoubtedly do great harm if appropriate precautions are not taken. Radioactivity in the stars and in the Earth and its wide range of applications in biomedicine, science, industry, agriculture are described, as well as the mechanisms of nuclear fission and fusion, and the harnessing of nuclear power. The issues surrounding safety and security and the increasing concerns about nuclear terrorism are also considered.

  10. Moons a very short introduction

    CERN Document Server

    Rothery, David A

    2015-01-01

    Moons: A Very Short Introduction introduces the reader to the varied and fascinating moons of our Solar System. Beginning with the early discoveries of Galileo and others, it describes their variety of mostly mythological names, and the early use of Jupiter’s moons to establish position at sea and to estimate the speed of light. It discusses the structure, formation, and profound influence of our Moon, those of the other planets, and ends with the recent discovery of moons orbiting asteroids, whilst looking forward to the possibility of discovering microbial life beyond Earth and of finding moons of exoplanets in planetary systems far beyond our own.

  11. Magnetism a very short introduction

    CERN Document Server

    Blundell, Stephen J

    2012-01-01

    Magnetism: A Very Short Introduction explains the mysteries and importance of magnetism. For centuries magnetism has been used for various exploits: as a great healer, a navigation aid through compasses, and through motors, generators, and turbines it has given us power. Our understanding of electricity and magnetism, from the work of Galvani, Ampère, Faraday, and Tesla is explored, and how Maxwell and Faraday's work led to the unification of electricity and magnetism is explained. With a discussion of the relationship between magnetism and relativity, quantum magnetism, and its impact on computers and information storage, how magnetism has changed our fundamental understanding of the Universe is shown.

  12. Isotopes a very short introduction

    CERN Document Server

    Ellam, Rob

    2016-01-01

    An isotope is a variant form of a chemical element, containing a different number of neutrons in its nucleus. Most elements exist as several isotopes. Many are stable while others are radioactive, and some may only exist fleetingly before decaying into other elements. In this Very Short Introduction, Rob Ellam explains how isotopes have proved enormously important across all the sciences and in archaeology. Radioactive isotopes may be familiar from their use in nuclear weapons, nuclear power, and in medicine, as well as in carbon dating. They have been central to establishing the age of the Earth and the origins of the solar system. Combining previous and new research, Ellam provides an overview of the nature of stable and radioactive isotopes, and considers their wide range of modern applications. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subjec...

  13. Very low level radioactive material

    International Nuclear Information System (INIS)

    Schaller, K.H.; Linsley, G.; Elert, M.

    1993-01-01

    Man's environment contains naturally occurring radionuclides and doses from exposures to these radionuclides mostly cannot be avoided. Consequently, almost everything may be considered as very low level radioactive material. In practical terms, management and the selection of different routes for low level material is confined to material which was subject to industrial processing or which is under a system of radiological control. Natural radionuclides with concentrations reaching reporting or notification levels will be discussed below; nevertheless, the main body of this paper will be devoted to material, mainly of artificial origin, which is in the system involving notification, registration and licensing of practices and sources. It includes material managed in the nuclear sector and sources containing artificially produced radionuclides used in hospitals, and in industry. Radioactive materials emit ionising radiations which are harmful to man and his environment. National and international regulations provide the frame for the system of radiation protection. Nevertheless, concentrations, quantities or types of radionuclide may be such, that the material presents a very low hazard, and may therefore be removed from regulatory control, as it would be a waste of time and effort to continue supervision. These materials are said to be exempted from regulatory control. Material exempted in a particular country is no longer distinguishable from ''ordinary'' material and may be moved from country to country. Unfortunately, criteria for exempting radioactive materials differ strongly between countries and free trade. Therefore there is a necessity for an international approach to be developed for exemption levels

  14. Copernicus a very short introduction

    CERN Document Server

    Gingerich, Owen

    2016-01-01

    Nicolaus Copernicus (1473–1543) was the astronomer whose shocking vision of a sun-centered universe turned out to be the essential blueprint for a physical understanding of celestial motions. Copernicus: A Very Short Introduction offers a fascinating portrayal of the man who launched the modern vision of the universe. It sets Copernicus in the context of a rapidly changing world, where the recent invention of printing with movable type not only made sources more readily available to him, but also fueled Martin Luther’s transformation of the religious landscape. Copernicus’s heliocentric revolution is revealed as an aesthetic achievement not dictated by observational “proofs,” but another new way of looking at the ancient cosmos.

  15. Infinity a very short introduction

    CERN Document Server

    Stewart, Ian

    2017-01-01

    Infinity is an intriguing topic, with connections to religion, philosophy, metaphysics, logic, and physics as well as mathematics. Its history goes back to ancient times, with especially important contributions from Euclid, Aristotle, Eudoxus, and Archimedes. The infinitely large (infinite) is intimately related to the infinitely small (infinitesimal). Cosmologists consider sweeping questions about whether space and time are infinite. Philosophers and mathematicians ranging from Zeno to Russell have posed numerous paradoxes about infinity and infinitesimals. Many vital areas of mathematics rest upon some version of infinity. The most obvious, and the first context in which major new techniques depended on formulating infinite processes, is calculus. But there are many others, for example Fourier analysis and fractals. In this Very Short Introduction, Ian Stewart discusses infinity in mathematics while also drawing in the various other aspects of infinity and explaining some of the major problems and insights ...

  16. Astrophysics a very short introduction

    CERN Document Server

    Binney, James

    2016-01-01

    Astrophysics is the physics of the stars, and more widely the physics of the Universe. It enables us to understand the structure and evolution of planetary systems, stars, galaxies, interstellar gas, and the cosmos as a whole. In this Very Short Introduction, the leading astrophysicist James Binney shows how the field of astrophysics has expanded rapidly in the past century, with vast quantities of data gathered by telescopes exploiting all parts of the electromagnetic spectrum, combined with the rapid advance of computing power, which has allowed increasingly effective mathematical modelling. He illustrates how the application of fundamental principles of physics - the consideration of energy and mass, and momentum - and the two pillars of relativity and quantum mechanics, has provided insights into phenomena ranging from rapidly spinning millisecond pulsars to the collision of giant spiral galaxies. This is a clear, rigorous introduction to astrophysics for those keen to cut their teeth on a conceptual trea...

  17. Creep at very low rates

    CSIR Research Space (South Africa)

    Nabarro, FRN

    2002-02-01

    Full Text Available stream_source_info nabarro_2002.pdf.txt stream_content_type text/plain stream_size 31615 Content-Encoding ISO-8859-1 stream_name nabarro_2002.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Creep at Very Low Rates F... to the necessary condition: vol. 29, p. 1285. 10. J.E. Harris, R.B. Jones, G.W. Greenwood, and M.J. Ward: J. Aust.L/b . m/2psp [5] Inst. Met., 1969, vol. 14, p. 154. 11. G.B. Gibbs: Mem. Sci. Rev. Met., 1965, vol. 62, p. 781.Even if this condition is satisfied, H...

  18. Chaos: A Very Short Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Klages, R [School of Mathematical Sciences, Mile End Road, London, E1 4NS (United Kingdom)

    2007-07-20

    This book is a new volume of a series designed to introduce the curious reader to anything from ancient Egypt and Indian philosophy to conceptual art and cosmology. Very handy in pocket size, Chaos promises an introduction to fundamental concepts of nonlinear science by using mathematics that is 'no more complicated than X=2. Anyone who ever tried to give a popular science account of research knows that this is a more challenging task than writing an ordinary research article. Lenny Smith brilliantly succeeds to explain in words, in pictures and by using intuitive models the essence of mathematical dynamical systems theory and time series analysis as it applies to the modern world. In a more technical part he introduces the basic terms of nonlinear theory by means of simple mappings. He masterly embeds this analysis into the social, historical and cultural context by using numerous examples, from poems and paintings over chess and rabbits to Olbers' paradox, card games and 'phynance'. Fundamental problems of the modelling of nonlinear systems like the weather, sun spots or golf balls falling through an array of nails are discussed from the point of view of mathematics, physics and statistics by touching upon philosophical issues. At variance with Laplace's demon, Smith's 21st century demon makes 'real world' observations only with limited precision. This poses a severe problem to predictions derived from complex chaotic models, where small variations of initial conditions typically yield totally different outcomes. As Smith argues, this difficulty has direct implications on decision-making in everyday modern life. However, it also asks for an inherently probabilistic theory, which somewhat reminds us of what we are used to in the microworld. There is little to criticise in this nice little book except that some figures are of poor quality thus not really reflecting the beauty of fractals and other wonderful objects in this

  19. Chaos: A Very Short Introduction

    International Nuclear Information System (INIS)

    Klages, R

    2007-01-01

    This book is a new volume of a series designed to introduce the curious reader to anything from ancient Egypt and Indian philosophy to conceptual art and cosmology. Very handy in pocket size, Chaos promises an introduction to fundamental concepts of nonlinear science by using mathematics that is 'no more complicated than X=2. Anyone who ever tried to give a popular science account of research knows that this is a more challenging task than writing an ordinary research article. Lenny Smith brilliantly succeeds to explain in words, in pictures and by using intuitive models the essence of mathematical dynamical systems theory and time series analysis as it applies to the modern world. In a more technical part he introduces the basic terms of nonlinear theory by means of simple mappings. He masterly embeds this analysis into the social, historical and cultural context by using numerous examples, from poems and paintings over chess and rabbits to Olbers' paradox, card games and 'phynance'. Fundamental problems of the modelling of nonlinear systems like the weather, sun spots or golf balls falling through an array of nails are discussed from the point of view of mathematics, physics and statistics by touching upon philosophical issues. At variance with Laplace's demon, Smith's 21st century demon makes 'real world' observations only with limited precision. This poses a severe problem to predictions derived from complex chaotic models, where small variations of initial conditions typically yield totally different outcomes. As Smith argues, this difficulty has direct implications on decision-making in everyday modern life. However, it also asks for an inherently probabilistic theory, which somewhat reminds us of what we are used to in the microworld. There is little to criticise in this nice little book except that some figures are of poor quality thus not really reflecting the beauty of fractals and other wonderful objects in this field. I feel that occasionally the book

  20. Gravity a very short introduction

    CERN Document Server

    Clifton, Timothy

    2017-01-01

    Gravity is one of the four fundamental interactions that exist in nature. It also has the distinction of being the oldest, weakest, and most difficult force to quantize. Understanding gravity is not only essential for understanding the motion of objects on Earth, but also the motion of all celestial objects, and even the expansion of the Universe itself. It was the study of gravity that led Einstein to his profound realizations about the nature of space and time. Gravity is not only universal, it is also essential for understanding the behavior of the Universe, and all astrophysical bodies within it. In this Very Short Introduction Timothy Clifton looks at the development of our understanding of gravity since the early observations of Kepler and Newtonian theory. He discusses Einstein's theory of gravity, which now supplants Newton's, showing how it allows us to understand why the frequency of light changes as it passes through a gravitational field, why GPS satellites need their clocks corrected as they orbi...

  1. Light a very short introduction

    CERN Document Server

    Walmsley, Ian

    2015-01-01

    Light enables us to see the world around us. Our sense of sight provides us with direct information about space and time, the physical arrangement of the world, and how it changes. This almost universal shared sensation of vision has led to a fascination with the nature and properties of light across the ages. But the light we see is just a small part of the whole spectrum of electromagnetic radiation, ranging from radio waves to gamma rays. In this Very Short Introduction Ian Walmsley discusses early attempts to explain light, and the development of apparently opposing particulate and wave theories by scientists such as Isaac Newton and Christiaan Huygens. He shows how light was recognized as an electromagnetic wave in the 19th century, and the development of the quantum mechanics view of wave-particle duality in the 20th century. He also describes the many applications of light, domestic and scientific, such as microwaves, DVDs, and lasers. We now use the whole range of electromagnetic radiation to peer bot...

  2. Very true operators on MTL-algebras

    Directory of Open Access Journals (Sweden)

    Wang Jun Tao

    2016-01-01

    Full Text Available The main goal of this paper is to investigate very true MTL-algebras and prove the completeness of the very true MTL-logic. In this paper, the concept of very true operators on MTL-algebras is introduced and some related properties are investigated. Also, conditions for an MTL-algebra to be an MV-algebra and a Gödel algebra are given via this operator. Moreover, very true filters on very true MTL-algebras are studied. In particular, subdirectly irreducible very true MTL-algebras are characterized and an analogous of representation theorem for very true MTL-algebras is proved. Then, the left and right stabilizers of very true MTL-algebras are introduced and some related properties are given. As applications of stabilizer of very true MTL-algebras, we produce a basis for a topology on very true MTL-algebras and show that the generated topology by this basis is Baire, connected, locally connected and separable. Finally, the corresponding logic very true MTL-logic is constructed and the soundness and completeness of this logic are proved based on very true MTL-algebras.

  3. Ranking Very Many Typed Entities on Wikipedia

    NARCIS (Netherlands)

    Zaragoza, Hugo; Rode, H.; Mika, Peter; Atserias, Jordi; Ciaramita, Massimiliano; Attardi, Guiseppe

    2007-01-01

    We discuss the problem of ranking very many entities of different types. In particular we deal with a heterogeneous set of types, some being very generic and some very specific. We discuss two approaches for this problem: i) exploiting the entity containment graph and ii) using a Web search engine

  4. Muhu uhkus - Pädaste Mõis sai esimeseks viietärni-hotell väljaspool Tallinna / Riina Luik

    Index Scriptorium Estoniae

    Luik, Riina, 1962-

    2009-01-01

    Augustis 2009 tunnustas Eesti Hotellide ja Restornide Liit Pädaste Mõisa neljanda hotellina Eestis ja esimesena väljaspool Tallinna asuvaks viietärni-hotelliks. Pädaste mõisa rajatud spa-hotelli ja restorani tootearendusest

  5. Landfill disposal of very low level waste

    International Nuclear Information System (INIS)

    Luo Shanggeng

    2009-01-01

    The radioactivities of very low level wastes are very low. VLLW can be disposed by simple and economic burial process. This paper describes the significance of segregation of very low level waste (VLLW), the VLLW-definition and its limit value, and presents an introduction of VLLW-disposing approaches operated world wide. The disposal of VLLW in China is also briefly discussed and suggested here. (author)

  6. Thermal conductivity at very low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Locatelli, M [CEA Centre d' Etudes Nucleaires de Grenoble, 38 (France). Service des Basses Temperatures

    1976-06-01

    The interest of low and very low temperatures in solid physics and especially that of thermal measurements is briefly mentioned. Some notes on the thermal conductivity of dielectrics, the method and apparatus used to measure this property at very low temperatures (T<1.5K) and some recent results of fundamental and applied research are then presented.

  7. Endovascular treatment of very small intracranial aneurysms

    DEFF Research Database (Denmark)

    Iskandar, A; Nepper-Rasmussen, J

    2011-01-01

    to large aneurysms (> 3 mm). However the data also suggest that endovascular treatment of very small aneurysms might be associated with an increased risk of procedural ruptures and mortality. At nine-month follow-up results indicate significantly less compaction in the very small aneurysms....... endovascular treatment was attempted in 956 consecutive intracranial aneurysms. Of 956 aneurysms, 111 aneurysms were very small aneurysms with a maximal diameter of 3 mm or less. We conducted a retrospective analysis of angiographic and clinical outcome following coiling of very small aneurysms...... aneurysms and less than 90% aneurysm occlusion in six aneurysms. Complications occurred in the treatment of 15 aneurysms, including eight procedural ruptures, six thromboembolic events and one case of early hemorrhage. Compared with larger aneurysms, treatment of very small aneurysms was associated...

  8. General very special relativity in Finsler cosmology

    International Nuclear Information System (INIS)

    Kouretsis, A. P.; Stathakopoulos, M.; Stavrinos, P. C.

    2009-01-01

    General very special relativity (GVSR) is the curved space-time of very special relativity (VSR) proposed by Cohen and Glashow. The geometry of general very special relativity possesses a line element of Finsler geometry introduced by Bogoslovsky. We calculate the Einstein field equations and derive a modified Friedmann-Robertson-Walker cosmology for an osculating Riemannian space. The Friedmann equation of motion leads to an explanation of the cosmological acceleration in terms of an alternative non-Lorentz invariant theory. A first order approach for a primordial-spurionic vector field introduced into the metric gives back an estimation of the energy evolution and inflation.

  9. The Expanded Very Large Array Project

    Science.gov (United States)

    Perley, Rick

    2012-10-01

    The Expanded Very Large Array Project, begun in 2001, is now completed -- on time, on budget, and ``on spec.'' The major goal of the project was to multiply the key observational capabilities of the Very Large Array -- the world's most powerful, versatile, and productive radio telescope -- by a factor of at least an order of magnitude by implementation of modern technologies. The result of the project is an operationally new telescope -- renamed the Jansky Very Large Array -- which is capable of new science unimagined in 1980, when the original VLA was completed. In this talk, I will review the goals of the project, and describe the new capabilities of the Jansky Very Large Array. Already, the array is providing fabulous new insights into the physics of the universe,and I will spend the majority of the time describing examples of new results.

  10. Very Complicated, indeed! / Jürgen Rooste

    Index Scriptorium Estoniae

    Rooste, Jürgen, 1979-

    2005-01-01

    Marco Laimre ja Killu Sukmiti näitus "Very Complicated Rock'n'Roll" Kunstihoone galeriis kuni 22. V. Heli: Indrek Pinsel, Andres Lõo, Riho Sibul, Erkki-Sven Tüür, Rainer Jancis (heliinstallatsiooni seadmine)

  11. VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR by. L. A. Agu ... order as that of the screw-thread motor can be obtained. LIST OF .... The n stator have equal non- magnetic spacers .... induction motor. An.

  12. Neutron moderation at very low temperatures (1691)

    International Nuclear Information System (INIS)

    Lacaze, A.

    1961-04-01

    Starting from Harwell experiment carried out inside a low-power reactor, we intended to maintain a liquid hydrogen cell in a channel of the EL3 reactor (at Saclay) whose thermal neutrons flux is 10 14 neutrons/cm 2 /s. We tried to work out a device giving off an important beam of cold neutrons and able to operate in a way as automatic as possible during many consecutive day without a stop. Several circuits have already been achieved at very low temperatures but they brought out volumes and fluxes much lower than those we used this time. The difficulties we have met in carrying out such a device arose on the one hand from the very high energy release to which any kind of experiment is inevitably submitted when placed near the core of the reactor, on the other, hand from the very little room which is available in experimental channels of reactors. In such condition, it is necessary to use a moderator as effective as possible. This study is divided into three parts ; in the first part, we try to determine: a) conditions in which moderation takes place, hence the volume of the cell; b) materials likely to be used at low temperature and in pile; c) cooling system; hence we had to study fluid flow conditions at very low temperatures in very long ducts. The second part is devoted to the description of the device. The third part ventilates the results we have obtained. (author) [fr

  13. Very high energy gamma-ray astronomy

    International Nuclear Information System (INIS)

    Weekes, T.C.

    1989-01-01

    It is apparent that very high gamma-ray astronomy, at the very end of the electromagnetic spectrum, is just at the threshold of becoming an important channel of astronomical information. The author discusses how, to fully develop, it requires telescopes with improved minimum flux sensitivity; development of techniques that characterize the nature of the primary; more overlapping observations to remove any question of the reality of the detected phenomenon; more consistency in the application of statistics among experimenters and more openness about methods used; development of models that will predict the phenomenon to be expected rather than explain what has been observed; and more accurate calibrations to determine absolute fluxes and energies

  14. Very fast kicker for accelerator applications

    International Nuclear Information System (INIS)

    Grishanov, B.I.; Podgorny, F.V.; Shiltsev, V.D.

    1996-11-01

    We describe a very fast counter traveling wave kicker with a full pulse width of about 7 ns. Successful test experiment has been done with hi-tech semiconductor technology FET pulse generator with a MHz- range repetition rates and maximum kick strength of the order of 3 G·m. Further. increase of the strength seems to be quite possible with the FET pursers, that makes the kicker to be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications

  15. The Reformation: A Very Short Introduction

    OpenAIRE

    TKACHENKO, Rostislav

    2017-01-01

    A small, relatively recent, and well-written book by Peter Marshall belongs tothe well-known Oxford series called “Very Short Introductions.” It is an informativeand analytical introduction to the history, culture, politics, and theology of theReformation that took place in sixteenth-century Europe. The Reformation is anacademic research-based book that is nevertheless very accessible to a wide audience. It is part of the larger company of historical and cultural mini-handbooks such as, The M...

  16. Frequency selectivity at very low centre frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Marquardt, Torsten

    2010-01-01

    measurements based on OAE suppression techniques and notched-noise masking data psychophysically measured for centre frequencies in the range 50-125 Hz, this study examines how individual differences in frequency selectivity, as well as in masking, may occur at very low CFs due to individual differences...

  17. The study of very high spin states

    International Nuclear Information System (INIS)

    Nolan, P.J.

    1992-01-01

    Some examples are given of the study of very high spin states that decay by discrete line gamma-ray emission. States up to spin 70(h/2π) have been seen in superdeformed bands. In other bands with normal deformation the limit is near 50(h/2π). (Author)

  18. Genre Identification of Very Brief Musical Excerpts

    Science.gov (United States)

    Mace, Sandra T.; Wagoner, Cynthia L.; Teachout, David J.; Hodges, Donald A.

    2012-01-01

    The purpose of this study was to examine how well individuals were able to identify different music genres from very brief excerpts and whether musical training, gender and preference played a role in genre identification. Listeners were asked to identify genre from classical, jazz, country, metal, and rap/hip hop excerpts that were 125, 250, 500,…

  19. Experiments on very high energy heavy ions

    International Nuclear Information System (INIS)

    Willis, W.J.

    1981-01-01

    In this paper I describe experimental techniques which could be used to investigate central collision of very high energy heavy ions. For my purposes, the energy range is defined by the number of pions produced, Nsub(π) >> 100, and consequently Nsub(π) >> Nsub(nucleon). In this regime we may expect that new phenomena will appear. (orig.)

  20. Very Good Medicine: Indigenous Humor and Laughter

    Science.gov (United States)

    Mala, Cynthia Lindquist

    2016-01-01

    Humor is not only instinctive and a basic human need, but it also is very good medicine. Laughter boosts the immune system, lowers blood pressure, reduces stress hormones, and is linked to healthy functioning organs. [This article was written with Mylo Redwater Smith.

  1. Building Very Large Neighbour-Joining Trees

    DEFF Research Database (Denmark)

    Simonsen, Martin; Mailund, Thomas; Pedersen, Christian Nørgaard Storm

    2010-01-01

    , and the NJ method in general, becomes a problem when inferring phylogenies with 10000+ taxa. In this paper we present two extentions of RapidNJ which reduce memory requirements and enable RapidNJ to infer very large phylogenetic trees efficiently. We also present an improved search heuristic for Rapid...

  2. Socioeconomic inequalities in very preterm birth rates.

    Science.gov (United States)

    Smith, L K; Draper, E S; Manktelow, B N; Dorling, J S; Field, D J

    2007-01-01

    To investigate the extent of socioeconomic inequalities in the incidence of very preterm birth over the past decade. Ecological study of all 549 618 births in the former Trent health region, UK, from 1 January 1994 to 31 December 2003. All singleton births of 22(+0) to 32(+6) weeks gestation (7 185 births) were identified from population surveys of neonatal services and stillbirths. Poisson regression was used to calculate incidence of very preterm birth (22-32 weeks) and extremely preterm birth (22-28 weeks) by year of birth and decile of deprivation (child poverty section of the Index of Multiple Deprivation). Incidence of very preterm singleton birth rose from 11.9 per 1000 births in 1994 to 13.7 per 1000 births in 2003. Those from the most deprived decile were at nearly twice the risk of very preterm birth compared with those from the least deprived decile, with 16.4 per 1000 births in the most deprived decile compared with 8.5 per 1000 births in the least deprived decile (incidence rate ratio 1.94; 95% CI (1.73 to 2.17)). This deprivation gap remained unchanged throughout the 10-year period. The magnitude of socio-economic inequalities was the same for extremely preterm births (22-28 weeks incidence rate ratio 1.94; 95% CI (1.62 to 2.32)). This large, unique dataset of very preterm births shows wide socio-economic inequalities that persist over time. These findings are likely to have consequences on the burden of long-term morbidity. Our research can assist future healthcare planning, the monitoring of socio-economic inequalities and the targeting of interventions in order to reduce this persistent deprivation gap.

  3. Development of very large helicon plasma source

    International Nuclear Information System (INIS)

    Shinohara, Shunjiro; Tanikawa, Takao

    2004-01-01

    We have developed a very large volume, high-density helicon plasma source, 75 cm in diameter and 486 cm in axial length; full width at half maximum of the plasma density is up to ∼42 cm with good plasma uniformity along the z axis. By the use of a spiral antenna located just outside the end of the vacuum chamber through a quartz-glass window, plasma can be initiated with a very low value of radio frequency (rf) power ( 12 cm -3 is successfully produced with less than several hundred Watt; achieving excellent discharge efficiency. It is possible to control the radial density profile in this device by changing the magnetic field configurations near the antenna and/or the antenna radiation-field patterns

  4. Bursts from the very early universe

    International Nuclear Information System (INIS)

    Silk, J.; Stodolsky, L.

    2006-01-01

    Bursts of weakly interacting particles such as neutrinos or even more weakly interacting particles such as wimps and gravitons from the very early universe would offer a much deeper 'look back time' to early epochs than is possible with photons. We consider some of the issues related to the existence of such bursts and their detectability. Characterizing the burst rate by a probability P per Hubble four-volume we find, for events in the radiation-dominated era, that the natural unit of description is the present intensity of the CMB times P. The existence of such bursts would make the observation of phenomena associated with very early times in cosmology at least conceptually possible. One might even hope to probe the transplanckian epoch if complexes more weakly interacting than the graviton can exist. Other conceivable applications include the potential detectability of the formation of 'pocket universes' in a multiverse

  5. Bursts from the very early universe

    Energy Technology Data Exchange (ETDEWEB)

    Silk, J. [Department of Physics, University of Oxford, Oxford OX1 3RH (United Kingdom); Stodolsky, L. [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)]. E-mail: les@mppmu.mpg.de

    2006-07-27

    Bursts of weakly interacting particles such as neutrinos or even more weakly interacting particles such as wimps and gravitons from the very early universe would offer a much deeper 'look back time' to early epochs than is possible with photons. We consider some of the issues related to the existence of such bursts and their detectability. Characterizing the burst rate by a probability P per Hubble four-volume we find, for events in the radiation-dominated era, that the natural unit of description is the present intensity of the CMB times P. The existence of such bursts would make the observation of pheno associated with very early times in cosmology at least conceptually possible. One might even hope to probe the transplanckian epoch if complexes more weakly interacting than the graviton can exist. Other conceivable applications include the potential detectability of the formation of 'pocket universes' in a multiverse.

  6. Advances in Very High Frequency Power Conversion

    DEFF Research Database (Denmark)

    Kovacevic, Milovan

    Resonant and quasi-resonant converters operated at frequencies above 30 MHz have attracted special attention in the last two decades. Compared to conventional converters operated at ~100 kHz, they offer significant advantages: smaller volume and weight, lower cost, and faster transient performance....... Excellent performance and small size of magnetic components and capacitors at very high frequencies, along with constant advances in performance of power semiconductor devices, suggests a sizable shift in consumer power supplies market into this area in the near future. To operate dc-dc converter power...... method provides low complexity and low gate loss simultaneously. A direct design synthesis method is provided for resonant SEPIC converters employing this technique. Most experimental prototypes were developed using low cost, commercially available power semiconductors. Due to very fast transient...

  7. Parallel motif extraction from very long sequences

    KAUST Repository

    Sahli, Majed

    2013-01-01

    Motifs are frequent patterns used to identify biological functionality in genomic sequences, periodicity in time series, or user trends in web logs. In contrast to a lot of existing work that focuses on collections of many short sequences, modern applications require mining of motifs in one very long sequence (i.e., in the order of several gigabytes). For this case, there exist statistical approaches that are fast but inaccurate; or combinatorial methods that are sound and complete. Unfortunately, existing combinatorial methods are serial and very slow. Consequently, they are limited to very short sequences (i.e., a few megabytes), small alphabets (typically 4 symbols for DNA sequences), and restricted types of motifs. This paper presents ACME, a combinatorial method for extracting motifs from a single very long sequence. ACME arranges the search space in contiguous blocks that take advantage of the cache hierarchy in modern architectures, and achieves almost an order of magnitude performance gain in serial execution. It also decomposes the search space in a smart way that allows scalability to thousands of processors with more than 90% speedup. ACME is the only method that: (i) scales to gigabyte-long sequences; (ii) handles large alphabets; (iii) supports interesting types of motifs with minimal additional cost; and (iv) is optimized for a variety of architectures such as multi-core systems, clusters in the cloud, and supercomputers. ACME reduces the extraction time for an exact-length query from 4 hours to 7 minutes on a typical workstation; handles 3 orders of magnitude longer sequences; and scales up to 16, 384 cores on a supercomputer. Copyright is held by the owner/author(s).

  8. A very light Higgs at LEP

    International Nuclear Information System (INIS)

    Brown, N.

    1990-01-01

    If the standard Higgs particle is very light (≤50 MeV) then it will be sufficiently long lived that it could decay outside the detectors at LEP. This could give a signal of two final state leptons which are not back-to-back, with missing transverse momentum. We show that with suitable cuts this Higgs signal can be distinguished from backgrounds with a large enough rate that such a light Higgs will either be discovered or completely ruled out. (author)

  9. Very-low-frequency magnetic plasma

    International Nuclear Information System (INIS)

    Pendry, J.B.; O'Brien, S.

    2002-01-01

    We show that a set of current-carrying wires can exhibit an effective magnetic permeability at very low frequencies of a few hertz. The resonant permeability, which is negative above the resonance frequency, arises from the oscillations of the wires driven by the applied magnetic field. We show that a large, frequency-specific and tunable effective permeability can be realized for a wide range of strengths of the applied field. (author)

  10. A very large multigap resistive plate chamber

    CERN Document Server

    Cerron-Zeballos, E; Hatzifotiadou, D; Kim, D W; Lamas-Valverde, J; Lee, S C; Platner, E D; Roberts, J; Williams, M C S; Zichichi, A

    1999-01-01

    We have built and tested a very large multigap resistive plate chamber (MRPC). We discuss the suitability of the multigap RPC for the construction of large area modules. We give details of the construction technique and results from a scan across the surface of the chamber. We also report on the implementation of `half-strip resolution', where we improve the spatial resolution by a factor 2 without increasing the number of read-out channels. (9 refs).

  11. Production and identification of very exotic nuclei

    International Nuclear Information System (INIS)

    Pougheon, F.

    1986-01-01

    New very exotic nuclei have been produced by fragmentation of the projectile at intermediate energy at GANIL. They have been identified through time of flight and ΔE-E measurements after a magnetic separation with the 0 0 LISE spectrometer. New neutron rich isotopes have been identified up to Z = 26 and evidence for the stability of the new series Tz = -5/2 has been shown. These results improve the knowledge of the neutron and proton drip lines

  12. Preparation of very pure active carbon

    International Nuclear Information System (INIS)

    Sloot, H.A. van der; Hoede, D.; Zonderhuis, J.; Meijer, C.

    1980-02-01

    The preparation of very pure active carbon is described. Starting from polyvinylidene chloride active carbon is prepared by carbonization in a nitrogen atmosphere, grinding, sieving and activation of the powder fraction with CO 2 at 950 0 to approximately 50% burn-off. The concentrations of trace and major elements are reduced to the ppb and ppm level, respectively. In the present set-up 100 g of carbon grains and approximately 50 g of active carbon powder can be produced weekly

  13. Discovery Mondays: The very early Universe

    CERN Multimedia

    2003-01-01

    Copyright NASARetracing the very early Universe to understand why there is "something rather than nothing" is one of the challenges facing astrophysics today. It is also the theme of the third Discovery Monday, to be held in the Microcosm on 7 July, where you will be welcomed by a number of scientists. A professional astronomer will allow you to look through his telescope and explain how it works. A cosmologist will talk to you about the very early Universe and a CERN physicist will show you how it's possible to trap antimatter. The mirror of matter, antimatter should have existed in the same quantities as matter in the very early stages of the Universe but today it seems to have virtually disappeared. Perhaps the research being done at CERN will one day explain how an infinitesimal predominance of matter over antimatter resulted in such a richly structured Universe. Come along to the Microcosm on Monday, 7 July between 7.30 p.m. and 9.00 p.m. Entrance is free http://www.cern.ch/microcosm N.B.: The Discove...

  14. Alkaptonuria: a very rare metabolic disorder.

    Science.gov (United States)

    Aquaron, Robert

    2013-10-01

    Alkaptonuria (AKU) is a very rare autosomal recessive disorder of tyrosine metabolism in the liver due to deficiency of homogentisate 1,2 dioxygenase (HGD) activity, resulting in the accumulation of homogentisic acid (HGA). Circulating HGA pass into various tissues through-out the body, mainly in cartilage and connective tissues, where its oxidation products polymerize and deposit as a melanin-like pigment. Gram quantities of HGA are excreted in the urine. AKU is a progressive disease and the three main features, according the chronology of appearance, are: darkening of the urine at birth, then ochronosis (blue-dark pigmentation of the connective tissue) clinically visible at around 30 yrs in the ear and eye, and finally a severe ochronotic arthropathy at around 50 yrs with spine and large joints involvements. Cardiovascular and renal complications have been described in numerous case report studies. A treatment now is available in the form of a drug nitisinone, which decreases the production of HGA. The enzymatic defect in AKU is caused by the homozygous or compound heterozygous mutations within the HGD gene. This disease has a very low prevalence (1:100,000-250,000) in most of the ethnic groups, except Slovakia and Dominican Republic, where the incidence has shown increase up to 1:19,000. This review highlights classical and recent findings on this very rare disease.

  15. Very forward measurements at the LHC

    CERN Document Server

    Berretti, Mirko

    2017-01-01

    In this talk we present a selection of forward physics results recently obtained with the run-1 and run-2 LHC data by the CMS, LHCf and TOTEM experiments. The status of the very forward LHC proton spectrometer, CT-PPS, is discussed: emphasis is given to the physics potential of CT-PPS and to the analyses that are currently ongoing with the data collected in 2016. Very recent forward measurements obtained with the LHCf and the CMS-CASTOR calorimeter are then addressed. In particular, CMS measured the inclusive energy spectrum in the very forward direction for proton-proton collisions at a center-of-mass energy of 13 TeV and the jet cross sections for p+Pb collisions at 5.02 TeV. The LHCf experiment has instead recently published the inclusive energy spectra of forward photons for pp collisions at 13 TeV. Finally, the new measurements of the total, elastic and inelastic cross sections obtained by the TOTEM collaboration at 2.76 and 13 TeV center of mass energy are presented.

  16. RISK FACTORS FOR VERY PRETERM DELIVERY

    Directory of Open Access Journals (Sweden)

    Наталья Витальевна Батырева

    2018-01-01

    Full Text Available The aim of the research – assess risk factors for very preterm delivery in the Omsk region. Materials and methods. The main group comprised women with very preterm delivery (n = 64; сomparison group – pregnant women with a threat of interruption in terms of 22-27 weeks and successful preserving therapy (n = 63; control group – pregnant women in whom this pregnancy was taking place without the threat of interruption (n = 62. Results. Risk factors for very preterm delivery were bacterial vaginosis, specific vaginitis, kidney disease and the threat of interruption. There was a significant lead in streptococci (32.3 ± 5.8 %, especially group B (19.0 ± 4.9 % in the main group. The risk factor for very preterm delivery was infectious viral diseases transferred during pregnancy, observed in 12.7 ± 4.2 % of women in the main group, in 7.8 ± 3.3 % in the comparison group (p < 0.01 and in 4.8 ± 2,7 % – control (p < 0,001. In the main group, placental insufficiency was 2 times more common than in the comparison group and 13 times than in the control group. Every sixth pregnant of the main group had manifestations of gestosis. Such complications of gestation as the premature detachment of the normally inserted placenta (7.8 ± 3.3 % and inborn malformations of a fruit (1.6 ± 1.6 % were observed only in the main group. Conclusion. The results of the research and literature data showed that the significant influence on the level of very early premature births is due to: the age of the parents, the abuse of nicotine, alcohol, drugs, abortion, preterm birth, urinary tract and genital tract infections, severe somatic diseases, multiple pregnancies. In the structure of complications of gestation during miscarriages, placental insufficiency predominates, the threat of abortion, fetal growth retardation, and polyhydramnios.

  17. Very high energy gamma ray astrophysics

    International Nuclear Information System (INIS)

    Lamb, R.C.; Lewis, D.A.

    1991-01-01

    The Whipple Observatory High Resolution Camera will be used in a vigorous program of observations to search for new sources of very-high-energy gamma rays. In addition, a search for antimatter using the moon-earth system as an ion spectrometer will be begun. The first phase of GRANITE, the new 37-element 11-m camera, will be concluded with first light scheduled for September, 1991. The two cameras will operate in support of the Gamma Ray Observatory mission in the winter of 1991/2

  18. A Very Cool Pair of Brown Dwarfs

    Science.gov (United States)

    2011-03-01

    Observations with the European Southern Observatory's Very Large Telescope, along with two other telescopes, have shown that there is a new candidate for the coldest known star: a brown dwarf in a double system with about the same temperature as a freshly made cup of tea - hot in human terms, but extraordinarily cold for the surface of a star. This object is cool enough to begin crossing the blurred line dividing small cold stars from big hot planets. Brown dwarfs are essentially failed stars: they lack enough mass for gravity to trigger the nuclear reactions that make stars shine. The newly discovered brown dwarf, identified as CFBDSIR 1458+10B, is the dimmer member of a binary brown dwarf system located just 75 light-years from Earth [1]. The powerful X-shooter spectrograph on ESO's Very Large Telescope (VLT) was used to show that the composite object was very cool by brown dwarf standards. "We were very excited to see that this object had such a low temperature, but we couldn't have guessed that it would turn out to be a double system and have an even more interesting, even colder component," said Philippe Delorme of the Institut de planétologie et d'astrophysique de Grenoble (CNRS/Université Joseph Fourier), a co-author of the paper. CFBDSIR 1458+10 is the coolest brown dwarf binary found to date. The dimmer of the two dwarfs has now been found to have a temperature of about 100 degrees Celsius - the boiling point of water, and not much different from the temperature inside a sauna [2]. "At such temperatures we expect the brown dwarf to have properties that are different from previously known brown dwarfs and much closer to those of giant exoplanets - it could even have water clouds in its atmosphere," said Michael Liu of the University of Hawaii's Institute for Astronomy, who is lead author of the paper describing this new work. "In fact, once we start taking images of gas-giant planets around Sun-like stars in the near future, I expect that many of them

  19. Investigation of very long jet chambers

    Energy Technology Data Exchange (ETDEWEB)

    Burckhart, H J; Va' vra, J; Zankel, K; Dudziak, U; Schaile, D; Schaile, O; Igo-Kemenes, P; Lennert, P

    1986-04-01

    The electrostatic properties and the performances of very long jet chambers have been investigated. Using 100 MHz FADC wave form digitisers, the tracking accuracy, the charge division and the dE/dx performance of two chambers, one with 4.5 m long tungsten wires and one with 4 m long highly resistive ''NiCoTi'' wires have been studied. The geometry of the chambers was chosen to define some of the design parameters of the jet chamber for the OPAL detector for LEP. (orig.).

  20. Investigation of very long jet chambers

    Energy Technology Data Exchange (ETDEWEB)

    Burckhart, H J; Va' vra, J; Zankel, K; Dudziak, U; Schaile, D; Schaile, O; Igo-Kemenes, P; Lennert, P

    1986-04-01

    The electrostatic properties and the performances of very long jet chambers have been investigated. Using 100 MHz FADC wave form digitisers, the tracking accuracy, the charge division and the dE/dx performance of two chambers, one with 4.5 m long tungsten wires and one with 4 m long highly resistive ''NiCoTi'' wires have been studied. The geometry of the chambers was chosen to define some of the design parameters of the jet chamber for the OPAL detector for LEP.

  1. Resonant magnetic pumping at very low frequency

    International Nuclear Information System (INIS)

    Canobbio, Ernesto

    1978-01-01

    We propose to exploit for plasma heating purposes the very low frequency limit of the Alfven wave resonance condition, which reduces essentially to safety factor q=m/n, a rational number. It is shown that a substantial fraction of the total RF-energy can be absorbed by the plasma. The lowest possible frequency value is determined by the maximum tolerable width of the RF-magnetic islands which develop near the singular surface. The obvious interest of the proposed scheme is the low frequency value (f<=10 KHz) which allows the RF-coils to be protected by stainless steel or even to be put outside the liner

  2. Kaon interactions with very light nuclei

    International Nuclear Information System (INIS)

    Gibson, B.F.

    1979-01-01

    Low energy kaon interactions (both K and anti K) with very light nuclei are reviewed. Limitations upon present K-nucleus studies due to uncertainties in the K-N amplitudes are emphasized along with promising uses. A brief review of some of the many interesting aspects of anti K-nucleus scattering is given. Comparison of the limited anti K-d and anti K- 4 He elastic data with theory is made. The anti Kd → πΛp reaction is discussed including the possible ΣN virtual bound state. 49 references

  3. Electronics for very high rate tracking detectors

    International Nuclear Information System (INIS)

    Williams, H.H.; Dressnandt, N.; Ekenberg, T.; Gerds, E.J.; Newcomer, F.M.; Tedja, S.; Van Berg, R.; Van der Speigel, J.

    1995-01-01

    Results are presented on a system of electronics designed for very high rate tracking detectors at the SSC and LHC. The primary goal was a system for signal detection, time measurement, and readout for the straw tracker for SDC. An integrated circuit incorporating eight channels of amplifier-shaper-discriminator (including detector tail cancellation), and two different integrated circuits for time measurement are described. The performance of tracking measurements up to counting rates of 8 MHz per wire is reported, as well as preliminary results from a baseline restoration circuit. (orig.)

  4. Black holes a very short introduction

    CERN Document Server

    Blundell, Katherine

    2015-01-01

    Black holes are a constant source of fascination to many due to their mysterious nature. Black Holes: A Very Short Introduction addresses a variety of questions, including what a black hole actually is, how they are characterized and discovered, and what would happen if you came too close to one. It explains how black holes form and grow—by stealing material that belongs to stars—as well as how many there may be in the Universe. It also explores the large black holes found in the centres of galaxies, and how black holes power quasars and lie behind other spectacular phenomena in the cosmos.

  5. Quantum gauge freedom in very special relativity

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Sudhaker, E-mail: sudhakerupadhyay@gmail.com [Centre for Theoretical Studies, Indian Institute of Technology Kharagpur, Kharagpur-721302, West Bengal (India); Panigrahi, Prasanta K., E-mail: pprasanta@iiserkol.ac.in [Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal (India)

    2017-02-15

    We demonstrate Yokoyama gaugeon formalism for the Abelian one-form gauge (Maxwell) as well as for Abelian two-form gauge theory in the very special relativity (VSR) framework. In VSR scenario, the extended action due to introduction of gaugeon fields also possesses form invariance under quantum gauge transformations. It is observed that the gaugeon field together with gauge field naturally acquire mass, which is different from the conventional Higgs mechanism. The quantum gauge transformation implements a shift in gauge parameter. Further, we analyze the BRST symmetric gaugeon formalism in VSR which embeds only one subsidiary condition rather than two.

  6. Symmetric splitting of very light systems

    International Nuclear Information System (INIS)

    Grotowski, K.; Majka, Z.; Planeta, R.

    1984-01-01

    Inclusive and coincidence measurements have been performed to study symmetric products from the reactions 74--186 MeV 12 C+ 40 Ca, 141 MeV 9 Be+ 40 Ca, and 153 MeV 6 Li+ 40 Ca. The binary decay of the composite system has been verified. Energy spectra, angular distributions, and fragment correlations are presented. The total kinetic energies for the symmetric products from these very light composite systems are compared to liquid drop model calculations and fission systematics

  7. Supersymmetry in the very early universe

    International Nuclear Information System (INIS)

    Thomas, S.

    1995-06-01

    Supersymmetric flat directions can have a number of important consequences in the very early universe. Depending on the form of the SUSY breaking potential arising from the finite energy density at early times, coherent production of scalar condensates can result along such directions. This leads a cosmological disaster for Polonyi type flat directions with only Planck suppressed couplings, but can give rise to the baryon asymmetry for standard model flat directions. Flat directions are also natural candidates to act as inflatons. Achieving density fluctuations of the correct magnitude generally requires an additional hidden SUSY breaking sector

  8. Burning actinides in very hard spectrum reactors

    International Nuclear Information System (INIS)

    Robinson, A.H.; Shirley, G.W.; Prichard, A.W.; Trapp, T.J.

    1978-01-01

    The major unresolved problem in the nuclear industry is the ultimate disposition of the waste products of light water reactors. The study demonstrates the feasibility of designing a very hard spectrum actinide burner reactor (ABR). A 1100 MW/sub t/ ABR design fueled entirely with actinides reprocessed from light water reactor (LWR) wastes is proposed as both an ultimate disposal mechanism for actinides and a means of concurrently producing usable power. Actinides from discharged ABR fuel are recycled to the ABR while fission products are routed to a permanent repository. As an integral part of a large energy park, each such ABR would dispose of the waste actinides from 2 LWRs

  9. A functional approach to cerebral visual impairments in very preterm/very-low-birth-weight children

    NARCIS (Netherlands)

    Geldof, C.J.A.; van Wassenaer-Leemhuis, A.G.; Dik, M.; Kok, J.H.; Oosterlaan, J.

    2015-01-01

    Background:Cerebral visual impairment (CVI) is a major cause of visual impairment, with very preterm birth/very low birth weight (VP/VLBW) being a major risk factor. There is no generally accepted definition of CVI. This study aims to investigate the usefulness of an empirically-based functional

  10. A functional approach to cerebral visual impairments in very preterm/very-low-birth-weight children

    NARCIS (Netherlands)

    Geldof, Christiaan J. A.; van Wassenaer-Leemhuis, Aleid G.; Dik, Marjolein; Kok, Joke H.; Oosterlaan, Jaap

    2015-01-01

    Cerebral visual impairment (CVI) is a major cause of visual impairment, with very preterm birth/very low birth weight (VP/VLBW) being a major risk factor. There is no generally accepted definition of CVI. This study aims to investigate the usefulness of an empirically-based functional definition of

  11. Growth pattern and final height of very preterm vs. very low birth weight infants

    NARCIS (Netherlands)

    Hollanders, J.J.; Pal, S.M. van der; Dommelen, P. van; Rotteveel, J.; Finken, M.J.J.

    2017-01-01

    BackgroundBoth very preterm (VP; i.e., gestational age <32 weeks) and very low birth weight (VLBW; i.e., birth weight <1,500 g) are used as inclusion criteria by studies on preterm birth. We aimed to quantify the impact of these entities on postnatal growth until final height.MethodsSubjects born VP

  12. HTGR fuel behavior at very high temperature

    International Nuclear Information System (INIS)

    Kashimura, Satoru; Ogawa, Touru; Fukuda, Kousaku; Iwamoto, Kazumi

    1986-03-01

    Fuel behavior at very high temperature simulating abnormal transient of the reactor operation and accidents have been investigated on TRISO coating LEU oxide particle fuels at JAERI. The test simulating the abnormal transient was carried out by irradiation of loose coated particles above 1600 deg C. The irradiation test indicated that particle failure was principally caused by kernel migration. For simulation of the core heat-up accident, two experiments of out-of-pile heating were made. Survival temperature limits were measured and fuel performance at very high temperature were investigated by the heatings. Study on the fuel behavior under reactivity initiated accident was made by NSRR(Nuclear Safety Research Reactor) pulse irradiation, where maximum temperature was higher than 2800 deg C. It was found in the pulse irradiation experiments that the coated particles incorporated in the compacts did not so severely fail unlike the loose coated particles at ultra high temperature above 2800 deg C. In the former particles UO 2 material at the center of the kernel vaporized, leaving a spherical void. (author)

  13. Neutron elastic scattering at very small angles

    CERN Multimedia

    2002-01-01

    This experiment will measure neutron-proton elastic scattering at very small angles and hence very small four-momentum transfer, |t|. The range of |t| depends on the incident neutron momentum of the events but the geometrical acceptance will cover the angular range 0.025 < $\\Theta_{lab}$ < 1.9 mrad. The higher figure could be extended to 8.4 mrad by changing the geometry of the experiment in a later phase. \\\\ \\\\ The neutron beam will be highly collimated and will be derived from a 400 GeV external proton beam of up to $4 \\times 10^{10}$ protons per pulse in the SPS North Area Hall 1. The hydrogen target will be gaseous, operating at 40 atm. pressure and acts as a multiwire proportional chamber to detect the recoil protons. The forward neutron will be detected and located by interaction in a neutron vertex detector and its energy measured by a conventional steel plate calorimeter. \\\\ \\\\ The experiment will cover the angular region of nucleon-nucleon scattering which is dominated by Coulomb scattering ...

  14. Very low field magnetic resonance imaging

    International Nuclear Information System (INIS)

    Herreros, Quentin

    2013-01-01

    The aim of this thesis is to perform Magnetic Resonance Imaging at very low field (from 1 mT to 10 mT). A new kind of sensor called 'mixed sensor' has been used to achieve a good detectivity at low frequencies. Combining a superconducting loop and a giant magnetoresistance, those detectors have a competitive equivalent field noise compared to existing devices (Tuned coils, SQUIDs and Atomic Magnetometers). They have been combined with flux transformers to increase the coupling between the sample and the sensor. A complete study has been performed to adapt it to mixed sensors and then maximize the gain. This set has been incorporated in an existing small MRI device to test its robustness in real conditions. In parallel, several MRI sequences (GE, SE, FLASH, EPI,...) have been integrated and adapted to very low field requirements. They have been used to perform in-vivo three dimensional imaging and relaxometry studies on well known products to test their reliability. Finally, a larger setup adapted for full-head imaging has been designed and built to perform images on a larger working volume. (author) [fr

  15. VERY LATE PHOTOMETRY OF SN 2011fe

    International Nuclear Information System (INIS)

    Kerzendorf, W. E.; Taubenberger, S.; Seitenzahl, I. R.; Ruiter, A. J.

    2014-01-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedented late epoch of ≈930 days with GMOS-N mounted on the Gemini North telescope (g = 23.43 ± 0.28, r = 24.14 ± 0.14, i = 23.91 ± 0.18, and z = 23.90 ± 0.17) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of 56 Co. This is in spite of theoretical predicted effects (e.g., infrared catastrophe, positron escape, and dust) that advocate a substantial energy redistribution and/or loss via various processes that result in a more rapid dimming at these very late epochs

  16. Developing very hard nanostructured bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Amel-Farzad, H., E-mail: hh_amel@yahoo.com [Department of Materials Engineering and Metallurgy, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Department of Materials Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Faridi, H.R., E-mail: faridihr@yahoo.com [Department of Materials Engineering and Metallurgy, Hamedan University of Technology, Hamedan (Iran, Islamic Republic of); Rajabpour, F.; Abolhasani, A.; Kazemi, Sh.; Khaledzadeh, Y. [Department of Materials Engineering and Metallurgy, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2013-01-01

    Novel nanostructured high carbon high silicon, carbide-free bainitic steels with very high strength and good ductility have been developed in the recent decade. In this work, an alloy with a high carbon content and no manganese was designed and cast. The prepared samples were heat treated through an austempering process in the range 200-350 Degree-Sign C. Optical and scanning electron microscopes and XRD were used to analyze the microstructures precisely. Bainitic ferrite plates of just a few tens of nanometer thickness were obtained with the hardness of 697{+-}6 HV. It is reasonable to say that the unprecedented hardness values obtained in this work are mostly caused by the extraordinary carbon content of the alloy.

  17. Indirect serarches for very heavy quarks

    International Nuclear Information System (INIS)

    Bigi, I.I.

    1987-03-01

    Detailed studies of weak decays can reveal the presence of very massive quanta like heavy top quarks or fourth family quarks. The decay K + → π + ν anti ν and B/sub d/ - anti B/sub d/ mixing are particularly promising fields for such searches. We infer a rather conservative lower limit of 70 GeV on the top mass form recent ARGUS data on B/sub d/ - anti B/sub d/ mixing, near-maximal B 8 - anti B 8 mixing is another consequence. If on the other hand top were detected in Z 0 decays, then the presence of New Physics would be established in B 0 decays. The ratio between tau(B 0 ) and tau(B +- ) is of considerable phenomenological relevance here

  18. Nuclear fuels for very high temperature applications

    International Nuclear Information System (INIS)

    Lundberg, L.B.; Hobbins, R.R.

    1992-01-01

    The success of the development of nuclear thermal propulsion devices and thermionic space nuclear power generation systems depends on the successful utilization of nuclear fuel materials at temperatures in the range 2000 to 3500 K. Problems associated with the utilization of uranium bearing fuel materials at these very high temperatures while maintaining them in the solid state for the required operating times are addressed. The critical issues addressed include evaporation, melting, reactor neutron spectrum, high temperature chemical stability, fabrication, fission induced swelling, fission product release, high temperature creep, thermal shock resistance, and fuel density, both mass and fissile atom. Candidate fuel materials for this temperature range are based on UO 2 or uranium carbides. Evaporation suppression, such as a sealed cladding, is required for either fuel base. Nuclear performance data needed for design are sparse for all candidate fuel forms in this temperature range, especially at the higher temperatures

  19. Pulsed neutron source very intense, Booster

    International Nuclear Information System (INIS)

    Abbate, J.M.

    1978-09-01

    A compact Accelerator-Booster (fast, pulsed and modulate reactivity research reactor) is a new and appropriate conception to use as a very intense thermal neutrons source. Its definition and feasibility have been already described in several studies showing its relative advantages in comparison with others kinds of facilities. This work, wich is part of one of those studies, contains a general analysis on the meis facility parameters and core and shielding theoretical calculations. The following results were obtained: Selection and test of a calculation system suitable to use in compact fast reactors; Development a method to perform estimations in some safety and shielding problems and obtainment of adequate theoretical predictions on the general performance. Moreover, final results for importent parameters of the feasibility study and predesign (critical mass and volume, lifetime, etc.) and others related to the use of plutonium oxide as fuel are given and then evaluations of different basic functions are showed. (author) [es

  20. Searches for very rare decays of kaons

    Energy Technology Data Exchange (ETDEWEB)

    Lang, K. [Univ. of Texas, Austin, TX (United States)

    1997-01-01

    The physics motivation for searches for very rare kaon decays, either forbidden or suppressed within the Standard Model, is briefly discussed. Simple arguments conclude that such searches probe possible new forces at a 200 TeV mass scale or constitute a precision test of the electroweak model. The examples of such process are decays of K{sub L}{sup 0} {yields} {mu} {sup {+-}}e{sup -+}, K{sup +} {yields} {pi}{sup +} {mu}{sup +} e{sup -}, K{sub L}{sup 0} {yields} {mu}{sup +} {mu}{sup -}, and K{sup +} {yields} {pi} {yields} {pi}{sup +}{nu}{bar {nu}}. We present the current experimental status and describe the new efforts to reach sensitivities down to one part in 10{sup 12}. The discussion is focused on the experimental program at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, where intense beams make such studies possible.

  1. Nitel Veri Analizinde Miles-Huberman Modeli

    OpenAIRE

    Baltacı, Ali

    2018-01-01

    Buaraştırmada, nitel araştırmalarda kullanılan veri analizi yöntemlerindenMiles-Huberman modelinin kuramsal temelleri ve uygulamaya yönelik stratejileriele alınmıştır. Bu çalışma özünde nitelveri analizinde araştırmacıların sıklıkla yöntembilim eksikliklerinden doğanuygulama sorunlarına karşı kavramsal bir zemin oluşturmayı hedeflemiştir.Çalışma ile nitel araştırma verilerinin analizinde eksikliği hissedilen kavramsalzemin oluşturulacak ve uygulamaya dönük stratejiler üzerinde durulacaktır. B...

  2. Systems engineering for very large systems

    Science.gov (United States)

    Lewkowicz, Paul E.

    Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

  3. Desalination by very low temperature nuclear heat

    International Nuclear Information System (INIS)

    Saari, Risto

    1977-01-01

    A new sea water desalination method has been developed: Nord-Aqua Vacuum Evaporation, which utilizes waste heat at a very low temperature. The requisite vacuum is obtained by the aid of a barometric column and siphon, and the dissolved air is removed from the vacuum by means of water flows. According to test results from a pilot plant, the process is operable if the waste heat exists at a temperature 7degC higher than ambient. The pumping energy which is then required is 9 kcal/kg, or 1.5% of the heat of vaporization of water. Calculations reveal that the method is economically considerably superior to conventional distilling methods. (author)

  4. Very high energy gamma-ray astronomy

    International Nuclear Information System (INIS)

    Weekes, T.C.

    1988-01-01

    Current interest in gamma-ray astronomy at energies above 100 GeV comes from the identification of Cygnus X-3 and other X-ray binaries as sources. In addition there are reports of emission from radio pulsars and a variety of other objects. The statistical significance of many of the observations is not high and many reported effects await confirmation, but there are a sufficient number of independent reports that very high energy gamma-ray astronomy must now be considered to have an observational basis. The observations are summarized with particular emphasis on those reported since 1980. The techniques used - the detection of small air showers using the secondary photons and particles at ground level - are unusual and are described. Future prospects for the field are discussed in relation to new ground-based experiments, satellite gamma-ray studies and proposed neutrino astronomy experiments. (orig.) With 296 refs

  5. Bilateral Supernumerary Kidney: A Very Rare Presentation

    International Nuclear Information System (INIS)

    Keskin, Suat; Batur, Abdussamet; Keskin, Zeynep; Koc, Abdulkadir; Firat Ozcan, Irfan

    2014-01-01

    To our knowledge, bilateral supernumerary kidney is a very rare renal abnormality and there are five cases presented in the literature. It is difficult to diagnose supernumerary kidney and clinicians have not detected most cases preoperatively. Laboratory and imaging studies were acquired and carefully examined. The normal laboratory tests were found. Emergency ultrasonography was performed and they revealed no signs of parenchymal abnormality in both kidneys. Serial imaging study including enhanced computed tomography (CT) was performed. An imaging study identified bilateral supernumerary kidney with expanded collecting systems. On each side, significant rotation anomaly was found. In addition, there were two different renal arteries originating from the aorta. This report presents radiological determinations of supernumerary kidney bilaterally in a young man. We think that CT commonly appears to be enough for the diagnosis of supernumerary kidneys

  6. Bilateral Supernumerary Kidney: A Very Rare Presentation

    Science.gov (United States)

    Keskin, Suat; Batur, Abdussamet; Keskin, Zeynep; Koc, Abdulkadir; Firat Ozcan, Irfan

    2014-01-01

    To our knowledge, bilateral supernumerary kidney is a very rare renal abnormality and there are five cases presented in the literature. It is difficult to diagnose supernumerary kidney and clinicians have not detected most cases preoperatively. Laboratory and imaging studies were acquired and carefully examined. The normal laboratory tests were found. Emergency ultrasonography was performed and they revealed no signs of parenchymal abnormality in both kidneys. Serial imaging study including enhanced computed tomography (CT) was performed. An imaging study identified bilateral supernumerary kidney with expanded collecting systems. On each side, significant rotation anomaly was found. In addition, there were two different renal arteries originating from the aorta. This report presents radiological determinations of supernumerary kidney bilaterally in a young man. We think that CT commonly appears to be enough for the diagnosis of supernumerary kidneys. PMID:25780543

  7. Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...... in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, shows results...... of the recent advances and describes the remaining challenges. The presented results include a self-oscillating gate-drive, air core inductor optimizations, an offline LED driver with a power density of 8.9 W/cm3 and a 120 MHz, 9 W DC powered LED driver with 89 % efficiency as well as a bidirectional VHF...

  8. A Very High Momentum Particle Identification Detector

    CERN Document Server

    Acconcia, T.V.; Barile, F.; Barnaföldi, G.G.; Bellwied, R.; Bencedi, G.; Bencze, G.; Berenyi, D.; Boldizsar, L.; Chattopadhyay, S.; Cindolo, F.; Chinellato, D.D.; D'Ambrosio, S.; Das, D.; Das, K.; Das-Bose, L.; Dash, A.K.; De Cataldo, G.; De Pasquale, S.; Di Bari, D.; Di Mauro, A.; Futo, E.; Garcia, E.; Hamar, G.; Harton, A.; Iannone, G.; Jimenez, R.T.; Kim, D.W.; Kim, J.S.; Knospe, A.; Kovacs, L.; Levai, P.; Nappi, E.; Markert, C.; Martinengo, P.; Mayani, D.; Molnar, L.; Olah, L.; Paic, G.; Pastore, C.; Patimo, G.; Patino, M.E.; Peskov, V.; Pinsky, L.; Piuz, F.; Pochybova, S.; Sgura, I.; Sinha, T.; Song, J.; Takahashi, J.; Timmins, A.; Van Beelen, J.B.; Varga, D.; Volpe, G.; Weber, M.; Xaplanteris, L.; Yi, J.; Yoo, I.K.

    2014-01-01

    The construction of a new detector is proposed to extend the capabilities of ALICE in the high transverse momentum (pT) region. This Very High Momentum Particle Identification Detector (VHMPID) performs charged hadron identification on a track-by-track basis in the 5 GeV/c < p < 25 GeV/c momentum range and provides ALICE with new opportunities to study parton-medium interactions at LHC energies. The VHMPID covers up to 30% of the ALICE central barrel and presents sufficient acceptance for triggered- and tagged-jet studies, allowing for the first time identified charged hadron measurements in jets. This Letter of Intent summarizes the physics motivations for such a detector as well as its layout and integration into ALICE.

  9. Very large area multiwire spectroscopic proportional counters

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F.

    1981-01-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) succesfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm 2 with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results. (orig.)

  10. Very large area multiwire spectroscopic proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F. (Istituto di Astrofisica Spaziale, Frascati (Italy))

    1981-07-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) successfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm/sup 2/ with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results.

  11. Very high intensity reaction chamber design

    International Nuclear Information System (INIS)

    Devaney, J.J.

    1975-09-01

    The problem of achieving very high intensity irradiation by light in minimal regions was studied. Three types of irradiation chamber are suggested: the common laser-reaction chamber, the folded concentric or near-concentric resonator, and the asymmetric confocal resonator. In all designs the ratio of high-intensity illuminated volume to other volume is highly dependent (to the 3 / 2 power) on the power and fluence tolerances of optical elements, primarily mirrors. Optimization of energy coupling is discussed for the common cavity. For the concentric cavities, optimization for both coherent and incoherent beams is treated. Formulae and numerical examples give the size of chambers, aspect ratios, maximum pass number, image sizes, fluences, and the like. Similarly for the asymmetric confocal chamber, formulae and numerical examples for fluences, dimensions, losses, and totally contained pass numbers are given

  12. Parametric nanomechanical amplification at very high frequency.

    Science.gov (United States)

    Karabalin, R B; Feng, X L; Roukes, M L

    2009-09-01

    Parametric resonance and amplification are important in both fundamental physics and technological applications. Here we report very high frequency (VHF) parametric resonators and mechanical-domain amplifiers based on nanoelectromechanical systems (NEMS). Compound mechanical nanostructures patterned by multilayer, top-down nanofabrication are read out by a novel scheme that parametrically modulates longitudinal stress in doubly clamped beam NEMS resonators. Parametric pumping and signal amplification are demonstrated for VHF resonators up to approximately 130 MHz and provide useful enhancement of both resonance signal amplitude and quality factor. We find that Joule heating and reduced thermal conductance in these nanostructures ultimately impose an upper limit to device performance. We develop a theoretical model to account for both the parametric response and nonequilibrium thermal transport in these composite nanostructures. The results closely conform to our experimental observations, elucidate the frequency and threshold-voltage scaling in parametric VHF NEMS resonators and sensors, and establish the ultimate sensitivity limits of this approach.

  13. Searches for very rare decays of kaons

    International Nuclear Information System (INIS)

    Lang, K.

    1997-01-01

    The physics motivation for searches for very rare kaon decays, either forbidden or suppressed within the Standard Model, is briefly discussed. Simple arguments conclude that such searches probe possible new forces at a 200 TeV mass scale or constitute a precision test of the electroweak model. The examples of such process are decays of K L 0 → μ ± e -+ , K + → π + μ + e - , K L 0 → μ + μ - , and K + → π → π + ν bar ν. We present the current experimental status and describe the new efforts to reach sensitivities down to one part in 10 12 . The discussion is focused on the experimental program at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, where intense beams make such studies possible

  14. Searches for very rare decays of kaons

    International Nuclear Information System (INIS)

    Lang, K.

    1995-01-01

    The physics motivation for searches for very rare kaon decays, either forbidden or suppressed within the Standard Model, is briefly discussed. Simple arguments conclude that such searches probe possible new forces at a 200 TeV mass scale or constitute a precision test of the electroweak model. The examples of such processes are decays of K L O →μ ± e minus-plus , K + →π + μ + e - , K L O →μ - , and K + →π + ν bar ν. We present the current experimental status and describe the new efforts to reach sensitivities down to 1 part in 10 12 . The discussion is focused on the experimental program at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, where intense beams make such studies possible

  15. A VERY BRIGHT, VERY HOT, AND VERY LONG FLARING EVENT FROM THE M DWARF BINARY SYSTEM DG CVn

    Energy Technology Data Exchange (ETDEWEB)

    Osten, Rachel A. [Space Telescope Science Institute (United States); Kowalski, Adam [U. Md/GSFC (United States); Drake, Stephen A. [USRA/CRESST and NASA/GSFC (United States); Krimm, Hans [USRA/CRESST (United States); Page, Kim [X-ray and Observational Astronomy Group, Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Gazeas, Kosmas [Department of Astrophysics, Astronomy and Mechanics, University of Athens, GR-15784 Zografos, Athens (Greece); Kennea, Jamie [Penn State (United States); Oates, Samantha [Instituto de Astrofsica de Andalucía (IAA-CSIC), Glorieta de la Astronomía s/n, E-18008, Granada (Spain); Page, Mathew [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking RH5 6NT (United Kingdom); De Miguel, Enrique [Departamento de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, E-21071 Huelva (Spain); Novák, Rudolf [Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Kamenice 3, 625 00 Brno (Czech Republic); Apeltauer, Tomas [Brno University of Technology, Faculty of Civil Engineering, Veveri 331/95, 602 00 Brno (Czech Republic); Gehrels, Neil, E-mail: osten@stsci.edu [NASA/GSFC (United States)

    2016-12-01

    On 2014 April 23, the Swift satellite responded to a hard X-ray transient detected by its Burst Alert Telescope, which turned out to be a stellar flare from a nearby, young M dwarf binary DG CVn. We utilize observations at X-ray, UV, optical, and radio wavelengths to infer the properties of two large flares. The X-ray spectrum of the primary outburst can be described over the 0.3–100 keV bandpass by either a single very high-temperature plasma or a nonthermal thick-target bremsstrahlung model, and we rule out the nonthermal model based on energetic grounds. The temperatures were the highest seen spectroscopically in a stellar flare, at T{sub X} of 290 MK. The first event was followed by a comparably energetic event almost a day later. We constrain the photospheric area involved in each of the two flares to be >10{sup 20} cm{sup 2}, and find evidence from flux ratios in the second event of contributions to the white light flare emission in addition to the usual hot, T  ∼ 10{sup 4} K blackbody emission seen in the impulsive phase of flares. The radiated energy in X-rays and white light reveal these events to be the two most energetic X-ray flares observed from an M dwarf, with X-ray radiated energies in the 0.3–10 keV bandpass of 4 × 10{sup 35} and 9 × 10{sup 35} erg, and optical flare energies at E{sub V} of 2.8 × 10{sup 34} and 5.2 × 10{sup 34} erg, respectively. The results presented here should be integrated into updated modeling of the astrophysical impact of large stellar flares on close-in exoplanetary atmospheres.

  16. A Very Bright, Very Hot, and Very Long Flaring Event from the M Dwarf Binary System DG CVn

    Science.gov (United States)

    Osten, Rachel A.; Kowalski, Adam; Drake, Stephen; Krimm, Hans; Page, Kim; Gazeas, Kosmas; Page, Mathew; Miguel, Enrique De; Novak, Rudolf; Gehrels, Cornelis

    2016-01-01

    On 2014 April 23, the Swift satellite responded to a hard X-ray transient detected by its Burst Alert Telescope, which turned out to be a stellar flare from a nearby, young M dwarf binary DG CVn. We utilize observations at X-ray, UV, optical, and radio wavelengths to infer the properties of two large flares. The X-ray spectrum of the primary outburst can be described over the 0.3100 kiloelectron volts bandpass by either a single very high-temperature plasma or a nonthermal thick-target bremsstrahlung model, and we rule out the nonthermal model based on energetic grounds. The temperatures were the highest seen spectroscopically in a stellar flare, at T(sub x) of 290 megakelvin. The first event was followed by a comparably energetic event almost a day later. We constrain the photospheric area involved in each of the two flares to be greater than 10(exp 20) sq cm, and find evidence from flux ratios in the second event of contributions to the white light flare emission in addition to the usual hot, T approximately 10(exp 4) K blackbody emission seen in the impulsive phase of flares. The radiated energy in X-rays and white light reveal these events to be the two most energetic X-ray flares observed from an M dwarf, with X-ray radiated energies in the 0.3-10 kiloelectron volts bandpass of 4 x 10(exp 35) and 9 x 10(exp 35) erg, and optical flare energies at E(sub V) of 2.8 x 10(exp 34) and 5.2 x 10(exp 34) erg, respectively. The results presented here should be integrated into updated modeling of the astrophysical impact of large stellar flares on close-in exoplanetary atmospheres.

  17. BOOK REVIEW: Chaos: A Very Short Introduction

    Science.gov (United States)

    Klages, R.

    2007-07-01

    This book is a new volume of a series designed to introduce the curious reader to anything from ancient Egypt and Indian philosophy to conceptual art and cosmology. Very handy in pocket size, Chaos promises an introduction to fundamental concepts of nonlinear science by using mathematics that is `no more complicated than X=2. Anyone who ever tried to give a popular science account of research knows that this is a more challenging task than writing an ordinary research article. Lenny Smith brilliantly succeeds to explain in words, in pictures and by using intuitive models the essence of mathematical dynamical systems theory and time series analysis as it applies to the modern world. In a more technical part he introduces the basic terms of nonlinear theory by means of simple mappings. He masterly embeds this analysis into the social, historical and cultural context by using numerous examples, from poems and paintings over chess and rabbits to Olbers' paradox, card games and `phynance'. Fundamental problems of the modelling of nonlinear systems like the weather, sun spots or golf balls falling through an array of nails are discussed from the point of view of mathematics, physics and statistics by touching upon philosophical issues. At variance with Laplace's demon, Smith's 21st century demon makes `real world' observations only with limited precision. This poses a severe problem to predictions derived from complex chaotic models, where small variations of initial conditions typically yield totally different outcomes. As Smith argues, this difficulty has direct implications on decision-making in everyday modern life. However, it also asks for an inherently probabilistic theory, which somewhat reminds us of what we are used to in the microworld. There is little to criticise in this nice little book except that some figures are of poor quality thus not really reflecting the beauty of fractals and other wonderful objects in this field. I feel that occasionally the book

  18. Doublet method for very fast autocoding

    Directory of Open Access Journals (Sweden)

    Berman Jules J

    2004-09-01

    Full Text Available Abstract Background Autocoding (or automatic concept indexing occurs when a software program extracts terms contained within text and maps them to a standard list of concepts contained in a nomenclature. The purpose of autocoding is to provide a way of organizing large documents by the concepts represented in the text. Because textual data accumulates rapidly in biomedical institutions, the computational methods used to autocode text must be very fast. The purpose of this paper is to describe the doublet method, a new algorithm for very fast autocoding. Methods An autocoder was written that transforms plain-text into intercalated word doublets (e.g. "The ciliary body produces aqueous humor" becomes "The ciliary, ciliary body, body produces, produces aqueous, aqueous humor". Each doublet is checked against an index of doublets extracted from a standard nomenclature. Matching doublets are assigned a numeric code specific for each doublet found in the nomenclature. Text doublets that do not match the index of doublets extracted from the nomenclature are not part of valid nomenclature terms. Runs of matching doublets from text are concatenated and matched against nomenclature terms (also represented as runs of doublets. Results The doublet autocoder was compared for speed and performance against a previously published phrase autocoder. Both autocoders are Perl scripts, and both autocoders used an identical text (a 170+ Megabyte collection of abstracts collected through a PubMed search and the same nomenclature (neocl.xml, containing over 102,271 unique names of neoplasms. In side-by-side comparison on the same computer, the doublet method autocoder was 8.4 times faster than the phrase autocoder (211 seconds versus 1,776 seconds. The doublet method codes 0.8 Megabytes of text per second on a desktop computer with a 1.6 GHz processor. In addition, the doublet autocoder successfully matched terms that were missed by the phrase autocoder, while the

  19. Very low resolution face recognition problem.

    Science.gov (United States)

    Zou, Wilman W W; Yuen, Pong C

    2012-01-01

    This paper addresses the very low resolution (VLR) problem in face recognition in which the resolution of the face image to be recognized is lower than 16 × 16. With the increasing demand of surveillance camera-based applications, the VLR problem happens in many face application systems. Existing face recognition algorithms are not able to give satisfactory performance on the VLR face image. While face super-resolution (SR) methods can be employed to enhance the resolution of the images, the existing learning-based face SR methods do not perform well on such a VLR face image. To overcome this problem, this paper proposes a novel approach to learn the relationship between the high-resolution image space and the VLR image space for face SR. Based on this new approach, two constraints, namely, new data and discriminative constraints, are designed for good visuality and face recognition applications under the VLR problem, respectively. Experimental results show that the proposed SR algorithm based on relationship learning outperforms the existing algorithms in public face databases.

  20. Theory Summary: Very High Energy Cosmic Rays

    Directory of Open Access Journals (Sweden)

    Sarkar Subir

    2013-06-01

    Full Text Available This is a summary of ISVHECRI 2012 from a theorist’s perspective. A hundred years after their discovery, there is renewed interest in very high energy cosmic raysand their interactions which can provide unique information on new physics well beyond the Standard Model if only we knew how to unambiguously decipher the experimental data. While the observational situation has improved dramatically on the past decade with regard to both improved statistics and better understood systematics, the long standing questions regarding the origin of cosmic rays remain only partially answered, while further questions have been raised by new data. A recent development discussed at this Symposium is the advent of forward physics data from several experiments at the LHC, which have broadly vindicated the air shower simulation Monte Carlos currently in use and reduced their uncertainties further. Nevertheless there is still a major extrapolation required to interpret the highest energy air showers observed which appear to be undergoing a puzzling change in their elemental composition, even casting doubt on whether the much vaunted GZK cutoff has indeedbeen observed. The situation is further compounded by the apparent disagreement between Auger and Telescope Array data. A crucial diagnostic will be provided by the detection of the accompanying ultra-high energy cosmic neutrinos — two intriguing events have recently been recorded by IceCube.

  1. Very-high-energy nuclear physics

    International Nuclear Information System (INIS)

    Frankel, S.

    1983-06-01

    In 1980 we carried out an extensive series of experiments on alpha-alpha collisions in the ISR. The purpose of the experiment was to discover something new for example, to search for some evidence of new correlated behaviour, and, in particular, to search for the existence of the formation of a quark-gluon plasma. The reason for this hope lay in the fact that the ISR experiments were to be carried out at ultrarelativistic energies of 1000 GeV/c in the alpha cm. This is a region where it is known that the mean pion multiplicities are very large and it is possible to sample events with event multiplicities of at least 200. Another important feature was the fact that remarkable spectrometers existed at the ISR to make definitive studies of the whole event structure. The apparatus of the AFS had the capability of detecting 50 charged particles in an apparatus covering 85% of the total solid angle. The momentum of each particle could be measured with high accuracy and protons, kaons, pions and their antiparticles could be identified, along with neutral lambdas and kaons. The ability to handle large multiplicities was important in the study of violent collisions. To describe the results of these experiments we shall list below the titles of papers published, in press, or in preparation which will have been completed by the end of this fiscal year, commenting on the results and their significance

  2. A very special visit from India

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    From India to Europe with a single destination in mind: CERN. This was the dream of five young students who convinced their parents to fund their travel costs and their school to organise the trip. Now, of course, they all plan to come back here as physicists. We have no doubt that they'll succeed!   Students, parents and teachers from Varanasi (India) are photographed here with CERN's Mick Storr and John Ellis. Everything was triggered by an electrical engineering course that some of the students were following at their school in Varanasi (India). Eeshan Jaiswal and his friend were involved in a project on electric charges and kept asking me about fundamental particles and how the subatomic world works,” says Dr. Raka Ray Mondal, a physics teacher at the Rajghat Besant High School, who organised the trip. “They were very keen on the project and we all started to get enthusiastic.” The next step was to find a contact person here at CERN but this ...

  3. Programmable, very low noise current source

    Science.gov (United States)

    Scandurra, G.; Cannatà, G.; Giusi, G.; Ciofi, C.

    2014-12-01

    We propose a new approach for the realization of very low noise programmable current sources mainly intended for application in the field of low frequency noise measurements. The design is based on a low noise Junction Field Effect Transistor (JFET) acting as a high impedance current source and programmability is obtained by resorting to a low noise, programmable floating voltage source that allows to set the sourced current at the desired value. The floating voltage source is obtained by exploiting the properties of a standard photovoltaic MOSFET driver. Proper filtering and a control network employing super-capacitors allow to reduce the low frequency output noise to that due to the low noise JFET down to frequencies as low as 100 mHz while allowing, at the same time, to set the desired current by means of a standard DA converter with an accuracy better than 1%. A prototype of the system capable of supplying currents from a few hundreds of μA up to a few mA demonstrates the effectiveness of the approach we propose. When delivering a DC current of about 2 mA, the power spectral density of the current fluctuations at the output is found to be less than 25 pA/√Hz at 100 mHz and less than 6 pA/√Hz for f > 1 Hz, resulting in an RMS noise in the bandwidth from 0.1 to 10 Hz of less than 14 pA.

  4. Development of Very High Temperature Reactor Technology

    International Nuclear Information System (INIS)

    Lee, Won Jae; Noh, J. M.; Kim, Y. H.

    2009-04-01

    For an efficient production of nuclear hydrogen, the VHTR (Very High Temperature Gas-cooled Reactor) of 950 .deg. C outlet temperature and the interfacing system for the hydrogen production are required. We have developed various evaluation technologies for the performance and safety of VHTR through the accomplishment of this project. First, to evaluate the performance of VHTR, a series of analyses has been performed such as core characteristics at 950 .deg. C, applicability of cooled-vessel, intermediate loop system and high temperature structural integrity. Through the analyses of major accidents such as HPCC and LPCC and the analysis of the risk/performance-informed method, VHTR safety evaluation has been also performed. In addition, various design analysis codes have been developed for a nuclear design, system loop design, system performance analysis, air-ingress accident analysis, fission product/tritium transport analysis, graphite structure seismic analysis and hydrogen explosion analysis, and they are being verified and validated through a lot of international collaborations

  5. Very Fast Delivery products of OMI

    Science.gov (United States)

    Hassinen, S.; Tamminen, J.; Tanskanen, A.; Mälkki, A.; Leppelmeier, G.; Aulamo, O.

    The Ozone Monitoring Instrument OMI operates onboard NASA s EOS-AURA satellite which was launched in July 2004 Aura s capabilities include Direct Broadcast DB i e the ability to broadcast data at the same time as they are being measured and stored in the spacecraft s memory for later transmission to Earth FMI s Satellite Data Centre at Sodankyla in Finnish Lapland is exploiting this capability to receive OMI data while Aura is in sight of the receiver which enables nearly immediate production of OMI data products for a region that includes a large part of Europe stretching from the North Pole to the Italian Alps The current OMI VFD Very Fast Delivery products include maps of surface UV-index erythemal daily dose ozone column and cloud coverage These products are available through WWW-pages in fifteen minutes after the overpass of the satellite From two to four overpasses are processed daily The processing system will be described and the results from validation studies will be shown Furthermore the usability of the DB will be discussed

  6. Control problems in very large accelerators

    International Nuclear Information System (INIS)

    Crowley-Milling, M.C.

    1985-06-01

    There is no fundamental difference of kind in the control requirements between a small and a large accelerator since they are built of the same types of components, which individually have similar control inputs and outputs. The main difference is one of scale; the large machine has many more components of each type, and the distances involved are much greater. Both of these factors must be taken into account in determining the optimum way of carrying out the control functions. Small machines should use standard equipment and software for control as much as possible, as special developments for small quantities cannot normally be justified if all costs are taken into account. On the other hand, the very great number of devices needed for a large machine means that, if special developments can result in simplification, they may make possible an appreciable reduction in the control equipment costs. It is the purpose of this report to look at the special control problems of large accelerators, which the author shall arbitarily define as those with a length of circumference in excess of 10 km, and point out where special developments, or the adoption of developments from outside the accelerator control field, can be of assistance in minimizing the cost of the control system. Most of the first part of this report was presented as a paper to the 1985 Particle Accelerator Conference. It has now been extended to include a discussion on the special case of the controls for the SSC

  7. Low and very low doses, new recommendations?

    International Nuclear Information System (INIS)

    Foucher, N.

    1999-01-01

    The topic of the seminar organized by the world council of nuclear workers (WONUC) was the effects of low or very low doses on human health. Discussions centred round the linearity of the relation between dose and effect in the evaluation and management of the health hazard. The recommendations proposed by ICPR (international commission for radiological protection) are based on this linearity as a precaution. On the one hand it is remembered that low dose irradiation might be beneficial. It has been proved that the irradiation of the whole body is efficient in case of Hodgkin lymphoma. On the other hand it is remembered that doses as low as 10 mSv in utero have led to an excess of cancer in children. Studies based on experimentally radio-induced cancers have been carried out in Japan, China, Canada and France.Their results seem to be not consistent with the hypothesis of linearity. During the last decade a lot of work has been made but a conclusion is far to be reached, it is said that the American department of energy (DOE) has invited bids in 1999 to launch research programs in order to clarify the situation. (A.C.)

  8. Order in very cold confined plasmas

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1995-01-01

    The study of the structure and dynamic properties of classical systems of charged particles confined by external forces, and cooled to very low internal energies, is the subject of this talk. An infinite system of identical charged particles has been known for some time to form a body-centered cubic lattice and is a simple classical prototype for condensed matter. Recent technical developments in storage rings, ion traps, and laser cooling of ions, have made it possible to produce such systems in the laboratory, though somewhat modified because of their finite size. I would like to discuss what one may expect in such systems and also show some examples of experiments. If we approximate the potential of an ion trap with an isotropic harmonic force F = -Kr then the Hamiltonian for this collection of ions is the same as that for J. J. Thomson's ''plum pudding'' model of the atom, where electrons were thought of as discrete negative charges imbedded in a larger, positive, uniformly charged sphere. The harmonic force macroscopically is canceled by the average space-charge forces of the plasma-, and this fixes the overall radius of the distribution. What remains, are the residual two-body Coulomb interactions that keep the particles within the volume as nearly equidistant as possible in order to minimize the potential energy. The configurations obtained for the minimum energy of small ionic systems [2] in isotropic confinement are shown in figure 1. Indeed this is an 'Exotic Atom' and fits well into the subject of this symposium honoring the 60th birthday of Professor Toshi Yamazaki

  9. Deep inelastic collisions between very heavy nuclei

    International Nuclear Information System (INIS)

    Sann, H.; Olmi, A.; Civelekoglu, Y.

    1977-01-01

    A systematic survey of deep inelastic reactions was performed for colliding nuclei of masses between 80 and 240 amu. The application of large surface detectors and, particularly, of a position sensitive ionization chamber, has proved to be very effective and appropriate for this type of investigation. The Wilczynski diagrams describing the relative motion between the colliding objects shows a gradual trend as a function of growing masses of target and projectile where the trajectories lead the particles not toward negative scattering angles but increasingly into the direction around and above the grazing angle. This behavior is attributed to a delicate balance between Coulomb and nuclear forces. The energy dumping as a function of the mass transfer strength matches a general law between total kinetic energy loss and the variance of the proton number distribution. For the partly damped component this relation seems to hold independently from the choice of ingoing channel and bombarding energy. The dissipation of the kinetic energy does not depend only on the relative velocity of the impinging nuclei, and the simple friction model is not appropriate to describe these processes. The γ-multiplicity measurement displays a rapid increase as a function of scattering angle and total kinetic energy loss, which give new insights to the process and indicate the necessity of microscopic quantum mechanical calculations of the interaction. In the U-U collision large mass transfers are present which possibly populate with relatively large cross sections the transuranic elements. In the Pb-Pb reaction the mass transfer is more restricted. The decay probability by fission of the primary masses increases strongly for growing masses and excitation energies

  10. The very-long-baseline array

    International Nuclear Information System (INIS)

    Kellermann, K.I.; Thompson, A.R.

    1988-01-01

    The development of radio technology in World War II opened a completely new window on the universe. When astronomers turned radio antennas to the heavens, they began to find a previously unknown universe of solar and planetary radio bursts, quasars, pulsars, radio galaxies, giant molecular clouds and cosmic masers. Not only do the radio waves reveal a new world of astronomical phenomena but also-because they are much longer than light waves-they are not as severely distorted by atmospheric turbulence or small imperfections in the telescope. About 25 years ago radio astronomers became aware that they could synthesize a resolution equivalent to that of a large aperture by combining data from smaller radio antennas that are widely separated. The effective aperture size would be about equal to the largest separation between the antennas. The technique is called synthesis imaging and is based on the principles of interferometry. Radio astronomers in the U.S. are now building a synthesis radio telescope called the Very-Long-Baseline Array, or VLBA. With 10 antennas sited across the country from the Virgin Islands to Hawaii, it will synthesize a radio antenna 8,000 kilometers across, nearly the diameter of the earth. The VLBA'S angular resolution will be less than a thousandth of an arc-second-about three orders of magnitude better than that of the largest conventional ground-based optical telescopes. Astronomers eagerly await the completion early in the next decade of the VLBA, which is expected, among other things, to give an unprecedentedly clear view into the cores of quasars and galactic nuclei and to reveal details of the processe-thought to be powered by black holes-that drive them

  11. Characteristics of repair following very low doses

    International Nuclear Information System (INIS)

    Braby, L.A.; Metting, N.F.; Nelson, J.M.

    1987-01-01

    The effects of ionizing radiation on living systems being with the physical processes of energy deposition and develop through many stages of chemical reaction and biological response. The modeling effort attempts to organize the available data and theories of all of these stages into self-consistent models that can be compared and tested. In some cases, important differences among models result in only small differences in cell survival within the ranges of dose and dose rate that are normally investigated. To overcome this limitation, new ways of irradiating cells at extremes of dose rate, or ways of evaluating the effects of very small doses, are developed. Mathematical modeling and cellular studies complement each other. It has recently been found that some mechanisms are not adequate to account for the interaction of dose and repair time as they affect the reproductive survival of plateau-phase Chinese hamster ovary (CHO) cells. Repair of radiation-induced cellular damage plays a central role in the survival of cells exposed to doses of 1 Gy or more. This repair is responsible for the dose rate, split-dose and delayed plating effect and can be evaluated. Because split-dose and dose-rate experiments involve repair during irradiation and delayed plating experiments involve repair after irradiation is completed, it was originally thought that different repair processes were involved. It is now clear that this is not necessarily the case. Appropriately designed models can account for observed effects at conventional doses (1 Gy or more) whether they assume all damage is lethal unless repaired or some damage is innocuous unless it interacts with additional damage. The fact that the survival following a plating delay is always less than the survival following immediate plating at low doses indicates that the damage produced is probably not potentially lethal

  12. Very high pulse-energy accelerators

    International Nuclear Information System (INIS)

    Ramirez, J.J.

    1989-01-01

    The dominant trend in the development of pulsed power accelerator technology over the last decade has been towards higher power and shorter pulse widths. Limitations in high voltage, high current switch performance, and in power flow through vacuum insulator housings led to the development of highly modular designs. This modular approach requires precise synchronization of the various modules and efficient methods of combining the power from these modules to drive a common load. The need to drive very low impedance loads led to effective ways to combine these modules in parallel. The Particle Beam Fusion Accelerator I (PBFA I) and Saturn are representative of these designs. Hermes III represent a new approach towards the efficient generation of higher voltages. It is designed to drive a 22-MV, 730-kA, 40-ns electron beam diode and combines conventional, modular pulsed power technology with linear induction accelerator concepts. High-power induction accelerator cavities are combined with voltage addition along a MITL to generate the desired output. This design differs from a conventional linac in that the voltages are added by the MITL flow rather than by a drifting beam that gains kinetic energy at each stage. This design is a major extrapolation of previous state-of-the-art technology represented by the injector module of the Advanced Test Accelerator and has proven to be efficient and reliable. The design and performance of Hermes III are presented together with a discussion of the application of this technology to the light ion beam inertial confinement fusion program. 18 refs., 9 figs

  13. Microlensing discovery of a population of very tight, very low mass binary brown dwarfs

    DEFF Research Database (Denmark)

    Choi, J.-Y.; Han, C.; Udalski, A.

    2013-01-01

    the discovery via gravitational microlensing of two very low mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 M ☉ and 0.034 M ☉, and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field BD binaries known....... The discovery of a population of such binaries indicates that BD binaries can robustly form at least down to masses of ~0.02 M ☉. Future microlensing surveys will measure a mass-selected sample of BD binary systems, which can then be directly compared to similar samples of stellar binaries....

  14. The Very Large Array Data Processing Pipeline

    Science.gov (United States)

    Kent, Brian R.; Masters, Joseph S.; Chandler, Claire J.; Davis, Lindsey E.; Kern, Jeffrey S.; Ott, Juergen; Schinzel, Frank K.; Medlin, Drew; Muders, Dirk; Williams, Stewart; Geers, Vincent C.; Momjian, Emmanuel; Butler, Bryan J.; Nakazato, Takeshi; Sugimoto, Kanako

    2018-01-01

    We present the VLA Pipeline, software that is part of the larger pipeline processing framework used for the Karl G. Jansky Very Large Array (VLA), and Atacama Large Millimeter/sub-millimeter Array (ALMA) for both interferometric and single dish observations.Through a collection of base code jointly used by the VLA and ALMA, the pipeline builds a hierarchy of classes to execute individual atomic pipeline tasks within the Common Astronomy Software Applications (CASA) package. Each pipeline task contains heuristics designed by the team to actively decide the best processing path and execution parameters for calibration and imaging. The pipeline code is developed and written in Python and uses a "context" structure for tracking the heuristic decisions and processing results. The pipeline "weblog" acts as the user interface in verifying the quality assurance of each calibration and imaging stage. The majority of VLA scheduling blocks above 1 GHz are now processed with the standard continuum recipe of the pipeline and offer a calibrated measurement set as a basic data product to observatory users. In addition, the pipeline is used for processing data from the VLA Sky Survey (VLASS), a seven year community-driven endeavor started in September 2017 to survey the entire sky down to a declination of -40 degrees at S-band (2-4 GHz). This 5500 hour next-generation large radio survey will explore the time and spectral domains, relying on pipeline processing to generate calibrated measurement sets, polarimetry, and imaging data products that are available to the astronomical community with no proprietary period. Here we present an overview of the pipeline design philosophy, heuristics, and calibration and imaging results produced by the pipeline. Future development will include the testing of spectral line recipes, low signal-to-noise heuristics, and serving as a testing platform for science ready data products.The pipeline is developed as part of the CASA software package by an

  15. Very Low Head Turbine Deployment in Canada

    International Nuclear Information System (INIS)

    Kemp, P; Williams, C; Sasseville, Remi; Anderson, N

    2014-01-01

    The Very Low Head (VLH) turbine is a recent turbine technology developed in Europe for low head sites in the 1.4 - 4.2 m range. The VLH turbine is primarily targeted for installation at existing hydraulic structures to provide a low impact, low cost, yet highly efficient solution. Over 35 VLH turbines have been successfully installed in Europe and the first VLH deployment for North America is underway at Wasdell Falls in Ontario, Canada. Deployment opportunities abound in Canada with an estimated 80,000 existing structures within North America for possible low-head hydro development. There are several new considerations and challenges for the deployment of the VLH turbine technology in Canada in adapting to the hydraulic, environmental, electrical and social requirements. Several studies were completed to determine suitable approaches and design modifications to mitigate risk and confirm turbine performance. Diverse types of existing weirs and spillways pose certain hydraulic design challenges. Physical and numerical modelling of the VLH deployment alternatives provided for performance optimization. For this application, studies characterizing the influence of upstream obstacles using water tunnel model testing as well as full-scale prototype flow dynamics testing were completed. A Cold Climate Adaptation Package (CCA) was developed to allow year-round turbine operation in ice covered rivers. The CCA package facilitates turbine extraction and accommodates ice forces, frazil ice, ad-freezing and cold temperatures that are not present at the European sites. The Permanent Magnet Generator (PMG) presents some unique challenges in meeting Canadian utility interconnection requirements. Specific attention to the frequency driver control and protection requirements resulted in a driver design with greater over-voltage capability for the PMG as well as other key attributes. Environmental studies in Europe included fish friendliness testing comprised of multiple in

  16. Very Low Head Turbine Deployment in Canada

    Science.gov (United States)

    Kemp, P.; Williams, C.; Sasseville, Remi; Anderson, N.

    2014-03-01

    The Very Low Head (VLH) turbine is a recent turbine technology developed in Europe for low head sites in the 1.4 - 4.2 m range. The VLH turbine is primarily targeted for installation at existing hydraulic structures to provide a low impact, low cost, yet highly efficient solution. Over 35 VLH turbines have been successfully installed in Europe and the first VLH deployment for North America is underway at Wasdell Falls in Ontario, Canada. Deployment opportunities abound in Canada with an estimated 80,000 existing structures within North America for possible low-head hydro development. There are several new considerations and challenges for the deployment of the VLH turbine technology in Canada in adapting to the hydraulic, environmental, electrical and social requirements. Several studies were completed to determine suitable approaches and design modifications to mitigate risk and confirm turbine performance. Diverse types of existing weirs and spillways pose certain hydraulic design challenges. Physical and numerical modelling of the VLH deployment alternatives provided for performance optimization. For this application, studies characterizing the influence of upstream obstacles using water tunnel model testing as well as full-scale prototype flow dynamics testing were completed. A Cold Climate Adaptation Package (CCA) was developed to allow year-round turbine operation in ice covered rivers. The CCA package facilitates turbine extraction and accommodates ice forces, frazil ice, ad-freezing and cold temperatures that are not present at the European sites. The Permanent Magnet Generator (PMG) presents some unique challenges in meeting Canadian utility interconnection requirements. Specific attention to the frequency driver control and protection requirements resulted in a driver design with greater over-voltage capability for the PMG as well as other key attributes. Environmental studies in Europe included fish friendliness testing comprised of multiple in

  17. Exploring Intrinsic and Extrinsic Reading Motivation among Very Good and Very Poor Readers

    Science.gov (United States)

    McGeown, Sarah P.; Norgate, Roger; Warhurst, Amy

    2012-01-01

    Background: Research examining the relationship between reading skill and reading motivation has typically been carried out among children with a wide range of reading abilities. There is less research focusing on children who excel in reading or who are attaining very low reading scores. Purpose: To examine whether there were differences between…

  18. FOREWORD: Workshop on "Very Hot Astrophysical Plasmas"

    Science.gov (United States)

    Koch-Miramond, Lydie; Montemerie, Thierry

    1984-01-01

    A Workshop on "Very Hot Astrophysical Plasmas" was held in Nice, France, on 8-10 November 1982. Dedicated mostly to theoretical, observational, and experimental aspects of X-ray astronomy and related atomic physics, it was the first of its kind to be held in France. The Workshop was "European" in the sense that one of its goals (apart from pure science) was to gather the European astronomical community in view of the forthcoming presentation of the "X-80" project for final selection to be the next scientific satellite of the European Space Agency. We now know that the Infrared Space Observatory has been chosen instead, but the recent successful launch of EXOSAT still keeps X-ray astronomy alive, and should be able to transfer, at least for a time, the leadership in this field from the U.S. to Europe, keeping in mind the competitive level of our Japanese colleagues. (With respect to the selection of ISO, one should also keep in mind that observations in the infrared often bring material relevant to the study of X-ray sources!) On a longer time scale, the Workshop also put emphasis on several interesting projects for the late eighties-early nineties, showing the vitality of the field in Europe. Some proposals have already taken a good start, like XMM, the X-ray Multi-Mirror project, selected by ESA last December for an assessment study in 1983. The present proceedings contain most of the papers that were presented at the Workshop. Only the invited papers were presented orally, contributed papers being presented in the form of posters but summarized orally by rapporteurs. To make up this volume, the written versions of these papers were either cross-reviewed by the Invited Speakers, or refereed by the Rapporteurs (for contributed papers) and edited by us, when necessary. Note, however, that the conclusions of the Workshop, which were kindly presented by Richard McCray, have already appeared in the "News and Views" section of Nature (301, 372, 1983). Altogether, the

  19. Intelligence of very preterm or very low birthweight infants in young adulthood.

    Science.gov (United States)

    Weisglas-Kuperus, N; Hille, E T M; Duivenvoorden, H J; Finken, M J J; Wit, J M; van Buuren, S; van Goudoever, J B; Verloove-Vanhorick, S P

    2009-05-01

    To examine the effect of intrauterine and neonatal growth, prematurity and personal and environmental risk factors on intelligence in adulthood in survivors of the early neonatal intensive care era. A large geographically based cohort comprised 94% of all babies born alive in the Netherlands in 1983 with a gestational age below 32 weeks and/or a birth weight >1500 g (POPS study). Intelligence was assessed in 596 participants at 19 years of age. Intrauterine and neonatal growth were assessed at birth and 3 months of corrected age. Environmental and personal risk factors were maternal age, education of the parent, sex and origin. The mean (SD) IQ of the cohort was 97.8 (15.6). In multiple regression analysis, participants with highly educated parents had a 14.2-point higher IQ than those with less well-educated parents. A 1 SD increase in birth weight was associated with a 2.6-point higher IQ, and a 1-week increase in gestational age was associated with a 1.3-point higher IQ. Participants born to young mothers (intelligence after early (symmetric) intrauterine growth retardation was more pronounced than after later (asymmetric) intrauterine or neonatal growth retardation. These differences in mean IQ remained when participants with overt handicaps were excluded. Prematurity as well as the timing of growth retardation are important for later intelligence. Parental education, however, best predicted later intelligence in very preterm or very low birthweight infants.

  20. A functional approach to cerebral visual impairments in very preterm/very-low-birth-weight children.

    Science.gov (United States)

    Geldof, Christiaan J A; van Wassenaer-Leemhuis, Aleid G; Dik, Marjolein; Kok, Joke H; Oosterlaan, Jaap

    2015-08-01

    Cerebral visual impairment (CVI) is a major cause of visual impairment, with very preterm birth/very low birth weight (VP/VLBW) being a major risk factor. There is no generally accepted definition of CVI. This study aims to investigate the usefulness of an empirically-based functional definition of CVI. One-hundred-five VP/VLBW children and 67 controls participated. CVI was defined after comprehensive oculomotor, visual sensory and perceptive assessment, and validated against vision problems in daily life and in terms of intellectual, behavioral, emotional and social functioning, as well as use of therapeutic services. Twenty-four per cent of the VP/VLBW children met criteria for CVI, compared to 7% of controls (P = 0.006, OR: 3.86, 95% CI: 1.40-10.70). VP/VLBW children with CVI had lower performance IQ, but not verbal IQ, than those without CVI. Visual problems in daily life were confirmed in VP/VLBW children classified with CVI. Additionally, difficulties in behavioral and social functioning were most prominent among VP/VLBW children with CVI. In VP/VLBW children, CVI defined in terms of visual function deficits is accompanied by intellectual, behavioral, and social impairments, validating our operational definition of CVI. CVI might act as a marker for developmental problems in VP/VLBW children.

  1. Rheological Properties of Very High-Strength Portland Cement Pastes: Influence of Very Effective Superplasticizers

    Directory of Open Access Journals (Sweden)

    Adriano Papo

    2010-01-01

    Full Text Available The influence of the addition of very effective superplasticizers, that are commercially available, employed for maximising the solid loading of very high-strength Portland cement pastes, has been investigated. Cement pastes were prepared from deionized water and a commercially manufactured Portland cement (Ultracem 52.5 R. Cement and water were mixed with a vane stirrer according to ASTM Standard C305. The 0.38 to 0.44 water/cement ratio range was investigated. Three commercial superplasticizing agents produced by Ruredil S.p.a. were used. They are based on a melamine resin (Fluiment 33 M, on a modified lignosulphonate (Concretan 200 L, and on a modified polyacrylate (Ergomix 1000. Rheological tests were performed at 25°C by using the rate controlled coaxial cylinder viscometer Rotovisko-Haake 20, system M5-osc., measuring device MV2P with serrated surfaces. The tests were carried out under continuous flow conditions. The results of this study were compared with those obtained in a previous article for an ordinary Portland cement paste.

  2. Very preterm/very low birthweight infants' attachment: infant and maternal characteristics.

    Science.gov (United States)

    Wolke, Dieter; Eryigit-Madzwamuse, Suna; Gutbrod, Tina

    2014-01-01

    To investigate whether there are differences in attachment security and disorganisation between very preterm or very low birthweight (VP/VLBW) (infants (37-42 weeks gestation) and whether the pathways to disorganised attachment differ between VP/VLBW and full-term infants. The sample with complete longitudinal data consisted of 71 VP/VLBW and 105 full-term children and their mothers matched for twin status, maternal age, income and maternal education. Infant attachment was assessed with the Strange Situation Assessment at 18 months of age. Maternal sensitivity in the VP/VLBW and full-term samples was rated by neonatal nurses and community midwives in the neonatal period, respectively, and mother-infant interaction was observed at 3 months. Infant difficultness was assessed by maternal report at 3 months and infant's developmental status was assessed with the Bayley Scales (BSID-II). Most VP/VLBW (61%) and full-term (72%) children were found to be securely attached. However, more VP/VLBW (32%) than full-term children (17%) had disorganised attachment. Longitudinal path analysis found that maternal sensitivity was predictive of attachment disorganisation in full-term children. In contrast, infant's distressing cry and infant's developmental delay, but not maternal sensitivity, were predictive of disorganised attachment in VP/VLBW children. A third of VP/VLBW children showed disorganised attachment. Underlying neurodevelopmental problems associated with VP/VLBW birth appear to be a common pathway to a range of social relationship problems in this group. Clinicians should be aware that disorganised attachment and relationship problems in VP/VLBW infants are frequent despite sensitive parenting.

  3. 7 CFR 51.2294 - Very serious damage.

    Science.gov (United States)

    2010-01-01

    ... serious damage. Very serious damage means any defect, other than color, which very seriously affects the... than one-fourth of the surface of the portion of kernel in the aggregate; (c) Discoloration of the meat...

  4. Very special conformal field theories and their holographic duals

    Science.gov (United States)

    Nakayama, Yu

    2018-03-01

    Cohen and Glashow introduced the notion of very special relativity as viable space-time symmetry of elementary particle physics. As a natural generalization of their idea, we study the subgroup of the conformal group, dubbed very special conformal symmetry, which is an extension of the very special relativity. We classify all of them and construct field theory examples as well as holographic realization of the very special conformal field theories.

  5. Motor development in very preterm and very low-birth-weight children from birth to adolescence: A meta-analysis

    NARCIS (Netherlands)

    de Kieviet, J.F.; Piek, J.P.; Aarnoudse-Moens, C.S.H.; Oosterlaan, J.

    2009-01-01

    Context: Infants who are very preterm (born ≤32 weeks of gestation) and very low birth weight (VLBW) (weighing ≤1500 g) are at risk for poor developmental outcomes. There is increasing evidence that very preterm birth and VLBW have a considerable effect on motor development, although findings are

  6. EDITORIAL: Very little is new in nanoscience Very little is new in nanoscience

    Science.gov (United States)

    Andrews, David L.

    2009-07-01

    science can only be applauded. Nanoscience affords a particularly fertile ground for cultivating student engagement with the broader societal implications of their studies. It embraces topics that invite reflection and debate—and where such debate moves into the public arena, it very much needs participation by properly informed individuals. Here is an opportunity not only to impress upon the next generation of scientists the need to be involved in public awareness, but also to equip them with a sound understanding of the scientific principles involved in nanotechnology. It is a great pleasure to have found, amongst the rapidly escalating number who work in this area, highly esteemed authors willing to produce papers especially for this special section of European Journal of Physics. My thanks are due to them for delivering almost on time, which is as much as one can reasonably ask. I trust they and many other readers will find the result of their endeavours thoroughly worthwhile. References [1] Piner R D, Zhu J, Xu F, Hong S and Mirkin C A 1999 Science 283 661-3 [2] Noy A (ed) 2008 Handbook of Molecular Spectroscopy (New York: Springer) [3] Dienerowitz M, Mazilu M and Dholakia K 2008 J. Nanophoton. 2 021875 [4] Kroto H 1988 Science 242 1139-45 [5] Freestone I, Meeks N, Sax M and Higgett C 2007 Gold Bull. 40 270-7 [6] Ball P 2009 Chem. World 6 58-62 [7] Andrews D L and Gaburro Z (ed) 2007 Frontiers in Surface Nanophotonics (New York: Springer) [8] Munshi D, Kurian P, Bartlett R V and Lakhtakia A 2007 Futures 39 432-52

  7. veri af bil - forbrydelsen der ikke findes

    DEFF Research Database (Denmark)

    Lentz, Lene Wacher

    2018-01-01

    Artiklen behandler den særegne strafferetlige problematik, at røveri af bil ikke straffes som sådan, men alene som ulovlig tvang og brugstyveri. Dette skyldes en formodning om, at tyven kun vil bruge bilen, ikke tilegne sig bilen. Konsekvensen bliver en langt lavere straf for "røveri af bil", end...

  8. Measurement of very low alpha activity in water

    International Nuclear Information System (INIS)

    Crespo, M. T.; Acena, M. L.

    1987-01-01

    Measurement of very low levels of alpha-emitting nuclides in water needs substantial improvements. A system based on the adsorbing properties manganese dioxide eliminates the need for transporting very large volumes of water and increases the sensitivity of the measurement. (Author) 21 refs

  9. The Radio And Very Low Frequency (VLF) Electromagnetic ...

    African Journals Online (AJOL)

    The Radio And Very Low Frequency (VLF) Electromagnetic Response Of A Layered Earth Media With Variable Dielectric Permittivity. ... A radio frequency of 125 KHz and a very low frequency (VLF) of 20 KHz were used in the computations and the field parameters studied over a dimensionless induction number, B. The ...

  10. Transient hypothyroxinaemia associated with developmental delay in very preterm infants

    NARCIS (Netherlands)

    Meijer, W.J.; Verloove-Vanhorick, S.P.; Brand, R.; Brande, J.L. van den

    1992-01-01

    In 563 surviving very preterm (<32 weeks gestational age) and/or very low birthweight (<1500 g) infants the relationship between neonatal thyroxine concentration and psychomotor development at 2 years of age (corrected for preterm birth) was studied. A significant association was found between low

  11. Book Review: Leslie Holmes, Corruption: A Very Short Introduction

    DEFF Research Database (Denmark)

    Keremis, Anestis

    2017-01-01

    Book review of: Corruption. A Very Short Introduction / by Leslie Holmes. Oxford: Oxford University Press, 2015. 143pp., £7.99 (p/b), ISBN 9780199689699.......Book review of: Corruption. A Very Short Introduction / by Leslie Holmes. Oxford: Oxford University Press, 2015. 143pp., £7.99 (p/b), ISBN 9780199689699....

  12. Mechanical properties of very thin cover slip glass disk

    Indian Academy of Sciences (India)

    Unknown

    Mechanical properties of very thin cover slip glass disk. A SEAL, A K DALUI, M BANERJEE, A K MUKHOPADHYAY* and K K PHANI. Central Glass and Ceramic Research Institute, Kolkata 700 032, India. Abstract. The biaxial flexural strength, Young's modulus, Vicker's microhardness and fracture toughness data for very ...

  13. 7 CFR 51.481 - Very good internal quality.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Very good internal quality. 51.481 Section 51.481 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... quality. Very good internal quality means that the combined juice from the edible portion of a sample of...

  14. Meta-analysis of neurobehavioral outcomes in very preterm and/or very low birth weight children

    NARCIS (Netherlands)

    C.S.H. Aarnoudse-Moens (Cornelieke); N. Weisglas-Kuperus (Nynke); J.B. van Goudoever (Hans); J. Oosterlaan (Jaap)

    2009-01-01

    textabstractOBJECTIVE: Sequelae of academic underachievement, behavioral problems, and poor executive function (EF) have been extensively reported for very preterm (≤33 weeks' gestation) and/or very low birth weight (VLBW) (≤1500 g) children. Great variability in the published results, however,

  15. Brain development of very preterm and very low‐birthweight children in childhood and adolescence: a meta‐analysis

    NARCIS (Netherlands)

    de Kieviet, J.F.; Zoetebier, L.; van Elburg, R.M.; Vermeulen, R.J.; Oosterlaan, J.

    2012-01-01

    Aim The aim of this article was to clarify the impact and consequences of very preterm birth (born <32wks of gestation) and/or very low birthweight ([VLBW], weighing <1500g) on brain volume development throughout childhood and adolescence. Method The computerized databases PubMed, Web of Knowledge,

  16. Brain development of very preterm and very low-birthweight children in childhood and adolescence: a meta-analysis

    NARCIS (Netherlands)

    de Kieviet, Jorrit F.; Zoetebier, Lydia; van Elburg, Ruurd M.; Vermeulen, R. Jeroen; Oosterlaan, Jaap

    2012-01-01

    Aim The aim of this article was to clarify the impact and consequences of very preterm birth (born <32wks of gestation) and/or very low birthweight ([VLBW], weighing <1500g) on brain volume development throughout childhood and adolescence. METHOD The computerized databases PubMed, Web of Knowledge,

  17. Social Lifestyle, Risk-taking Behavior, and Psychopathology in Young Adults Born Very Preterm or with a Very Low Birthweight

    NARCIS (Netherlands)

    Hille, E.T.M.; Dorrepaal, C.; Perenboom, R.; Gravenhorst, J.B.; Brand, R.; Verloove-Vanhorick, S.P.

    2008-01-01

    Objective: To assess social lifestyle, risk-taking behavior, and psychopathology in young adults born very preterm or with a very low birthweight. Study design: This study was part of the 19-year follow-up in a large ongoing collaborative study in the Netherlands (the POPS study) on the long-term

  18. Social lifestyle, risk-taking behavior, and psychopathology in young adults born very preterm or with a very low birthweight

    NARCIS (Netherlands)

    Hille, Elysée T. M.; Dorrepaal, Caroline; Perenboom, Rom; Gravenhorst, Jack Bennebroek; Brand, Ronald; Verloove-Vanhorick, S. Pauline; Hille, E. T. M.; de Groot, C. H.; Kloosterboer-Boerrigter, H.; den Ouden, A. L.; Rijpstra, A.; Verloove-Vanhorick, S. P.; Vogelaar, J. A.; Kok, J. H.; Ilsen, A.; van der Lans, M.; Boelen-van der Loo, W. J. C.; Lundqvist, T.; Heymans, H. S. A.; Duiverman, E. J.; Geven, W. B.; Duiverman, M. L.; Geven, L. I.; Vrijlandt, E. J. L. E.; Mulder, A. L. M.; Gerver, A.; Kollée, L. A. A.; Reijmers, L.; Sonnemans, R.; Wit, J. M.; Dekker, F. W.; Finken, M. J. J.; Weisglas-Kuperus, N.; Keijzer-Veen, M. G.; van der Heijden, A. J.; van Goudoever, J. B.; van Weissenbruch, M. M.; Cranendonk, A.; Delemarre-van de Waal, H. A.; de Groot, L.; Samsom, J. F.; de Vries, L. S.; Rademaker, K. J.; Moerman, E.; Voogsgeerd, M.; de Kleine, M. J. K.; Andriessen, P.; Dielissen-van Helvoirt, C. C. M.; Mohamed, I.; van Straaten, H. L. M.

    2008-01-01

    OBJECTIVE: To assess social lifestyle, risk-taking behavior, and psychopathology in young adults born very preterm or with a very low birthweight. STUDY DESIGN: This study was part of the 19-year follow-up in a large ongoing collaborative study in The Netherlands (the POPS study) on the long-term

  19. Batched Triangular DLA for Very Small Matrices on GPUs

    KAUST Repository

    Charara, Ali; Keyes, David E.; Ltaief, Hatem

    2017-01-01

    linear algebra operations on very small matrix sizes (usually less than 100). Batched dense linear algebra kernels are becoming ubiquitous for such scientific computations. Within a single API call, these kernels are capable of simultaneously launching a

  20. The future of very low level radioactive wastes in question

    International Nuclear Information System (INIS)

    Vignes, Emmanuelle

    2016-01-01

    After having recalled that nuclear plants produce various radioactive wastes, that the Cigeo project is the proposed solution to store these radioactive wastes, this article more particularly addresses the issue of very low level radioactive wastes which are now the main matter of concern for the IRSN as their quantity is expected to increase during the years to come (notably in relationship with nuclear reactor lifetime extension), and as present storage capacities will soon be saturated. The author first outlines that these wastes are not very dangerous but very cumbersome. Among these so-defined 'very low level' wastes, 30 to 50 per cent could be considered as harmless, but are now processed as dangerous wastes through costly processes. Various possibilities are then envisaged such as a diversification of storage options

  1. "Veri hakkab voolama" filmiajakirjanike aasta parim / J. R.

    Index Scriptorium Estoniae

    J. R.

    2008-01-01

    Paul Thomas Andersoni Upton Sinclairi "Õli" järgi lavastatud "Veri hakkab voolama" ("There Will Be Blood") : Ameerika Ühendriigid 2007. Filmi hääletas aasta parimaks Rahvusvaheline Filmiajakirjanike Föderatsioon (FIPRESCI)

  2. Nuclear design of a very-low-activation fusion reactor

    International Nuclear Information System (INIS)

    Cheng, E.T.; Hopkins, G.R.

    1983-06-01

    An investigation was conducted to study the nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE tokamak reactor design

  3. A pulse amplitude discriminator with very low-power consuming

    International Nuclear Information System (INIS)

    Deng Changming; Liu Zhengshan; Zhang Zhiyong; Cheng Chang

    2000-01-01

    A low-power pulse amplitude discriminator is described. The discriminator circuit is mainly composed of an integrated voltage comparator, MAX921, and owns the characters of very low-power and low operating voltage

  4. Very-High Efficiency, High Power Laser Diodes, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — AdTech Photonics, in collaboration with the Center for Advanced Studies in Photonics Research (CASPR) at UMBC, is pleased to submit this proposal entitled ?Very-High...

  5. The gendered socialization of very young adolescents in schools ...

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

    ... of very young adolescents in schools and sexual and reproductive health ... It will generate information on what evidence-based and low-cost interventions are effective ... foster positive gender norms, and facilitate the exercise of SRH rights.

  6. Very high plasma switches. Basic plasma physics and switch technology

    International Nuclear Information System (INIS)

    Doucet, H.J.; Roche, M.; Buzzi, J.M.

    1988-01-01

    A review of some high power switches recently developed for very high power technology is made with a special attention to the aspects of plasma physics involved in the mechanisms, which determine the limits of the possible switching parameters

  7. Hurricane Satellite (HURSAT) from Advanced Very High Resolution Radiometer (AVHRR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Huricane Satellite (HURSAT)-Advanced Very High Resolution Radiometer (AVHRR) is used to extend the HURSAT data set such that appling the Objective Dvorak technique...

  8. Very Slow Speed Axial Motion Reluctance Motor | Agu | Nigerian ...

    African Journals Online (AJOL)

    Abstract. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low order as that of the screw-thread motor can be obtained.

  9. Birth weight recovery among very low birth weight infants surviving ...

    African Journals Online (AJOL)

    Very low birth weight (VLBW) infants are those born weighing less ... an association between retinopathy of prematurity and poor weight gain. .... LGA = large for gestational age; SGA = small for gestational age; NEC = necrotising enterocolitis;.

  10. Evaluation of cytogenetic effects of very short laser pulsed radiations

    International Nuclear Information System (INIS)

    Guedeney, G.; Courant, D.; Malarbet, J.-L.; Dolloy, M.-T.; Court, L.

    1992-01-01

    The aim of this study is to evaluate the capacity of a laser, delivering very short pulses in the near infrared spectrum with a high pulse ratio frequency, to induce genetic modification on biological tissues. Chromatid exchanges and chromosomal aberrations studies are used to test potential effect on human lymphocytes. The laser irradiation induces a significant increase of acentric fragments but the absence of dicentric suggests that a repetitive very short pulses irradiation has a relatively low capacity to induce genetic abnormalities. (author)

  11. Pressurized-helium breakdown at very low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Metas, R J

    1972-06-01

    An investigation of the electrical-breakdown behavior of helium at very low temperatures has been carried out to assist the design and development of superconducting power cables. At very high densities, both liquid and gaseous helium showed an enhancement in electric strength when pressurized to a few atmospheres; conditioned values of breakdown fields then varied between 30 and 45 MV/m. Breakdown processes occurring over a wide range of helium densities are discussed. 24 references.

  12. Design considerations and expectations of a very large hadron collider

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1996-01-01

    The ELOISATRON Project is a proton-proton collider at very high energy and very large luminosity. The main goal is to determine the ultimate performance that is possible to achieve with reasonable extrapolation of the present accelerator technology. A complete study and design of the collider requires that several steps of investigations are undertaken. The authors count five of such steps as outlined in the report

  13. Why do very unattractive workers earn so much?

    Science.gov (United States)

    Kanazawa, Satoshi; Hu, Shihao; Larere, Adrien

    2018-05-01

    Kanazawa and Still (2018) showed that very unattractive workers earned more than unattractive workers, sometimes more than average-looking or attractive workers, because they had higher levels of intelligence and education, but they did not explain why very unattractive workers had higher intelligence and education. There are both theoretical and empirical reasons to expect that some intelligent men may prefer to marry very unattractive women. The analysis of the National Longitudinal Study of Adolescent Health (Add Health) shows that very unattractive women were significantly more likely to be married at Age 29 than unattractive or average-looking women, and their spouses or partners earned significantly more than those of unattractive or average-looking women. If intelligent men have historically preferred to marry very unattractive women generation after generation, then, because both general intelligence and physical attractiveness are highly heritable, this can explain why very unattractive workers are more intelligent and achieve higher education, thereby earning more. It can also explain why the positive correlation between intelligence and physical attractiveness is not larger despite assortative mating of intelligent men of higher status and physically attractive women over many generations. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Very massive runaway stars from three-body encounters

    Science.gov (United States)

    Gvaramadze, Vasilii V.; Gualandris, Alessia

    2011-01-01

    Very massive stars preferentially reside in the cores of their parent clusters and form binary or multiple systems. We study the role of tight very massive binaries in the origin of the field population of very massive stars. We performed numerical simulations of dynamical encounters between single (massive) stars and a very massive binary with parameters similar to those of the most massive known Galactic binaries, WR 20a and NGC 3603-A1. We found that these three-body encounters could be responsible for the origin of high peculiar velocities (≥70 km s-1) observed for some very massive (≥60-70 M⊙) runaway stars in the Milky Way and the Large Magellanic Cloud (e.g. λ Cep, BD+43°3654, Sk -67°22, BI 237, 30 Dor 016), which can hardly be explained within the framework of the binary-supernova scenario. The production of high-velocity massive stars via three-body encounters is accompanied by the recoil of the binary in the opposite direction to the ejected star. We show that the relative position of the very massive binary R145 and the runaway early B-type star Sk-69°206 on the sky is consistent with the possibility that both objects were ejected from the central cluster, R136, of the star-forming region 30 Doradus via the same dynamical event - a three-body encounter.

  15. Health Behaviours during Pregnancy in Women with Very Severe Obesity

    Directory of Open Access Journals (Sweden)

    Nor A. Mohd-Shukri

    2015-10-01

    Full Text Available The health behaviours of pregnant women with very severe obesity are not known, though these women are at high risk of pregnancy complications. We carried out a prospective case-control study including 148 very severely obese (BMI >40 kg/m2 and 93 lean (BMI <25 kg/m2 pregnant women. Diet, physical activity, smoking, alcohol and folic acid consumption were assessed by questionnaire in early and late (16 and 28 weeks gestation pregnancy. Circulating levels of iron, vitamin B12 and folate and other essential trace elements and minerals were measured in a subset at each time point. The findings biochemically confirmed that very severely obese women consumed diets that were energy-rich but poor in essential micronutrients. A third of all women met physical activity recommendations for pregnancy. A third of very severely obese women and two thirds of lean women took folic acid supplements prior to pregnancy. Very severely obese women were more likely to smoke but less likely to drink alcohol than lean women (all p < 0.05. Women with very severe obesity have low self-reported intakes and circulating levels of essential micronutrients in pregnancy and few follow current recommendations for pregnancy nutrition and lifestyle. These high-risk women represent a group to target for education about health behaviours prior to and during pregnancy.

  16. Psychiatric hospitalisation and suicide among the very old in Denmark

    DEFF Research Database (Denmark)

    Erlangsen, Annette; Mortensen, Preben Bo; Vach, Werner

    2005-01-01

    BACKGROUND: Very old people have higher suicide rates than the younger elderly population. Psychiatric disorders are known to have a strong association with suicide among elderly people. AIMS: To analyse the analyse the suicide risk associated with psychiatric hospitalisation among the very old...... (> or =80 years) compared with the middle-aged (50-64 years) and old (65-79 years) populations. METHOD: Individual-level data on the entire Danish population aged 50 years or over were analysed for the period 1994-1998. Relative suicide risks were calculated using event-history analysis. RESULTS: Among 1978...... 527 persons, 2323 died by suicide. Although the very old group exhibited a four-fold to five-fold increase in risk of suicide for those previously hospitalised, we noted an inverse interaction effect: the increase is distinctly smaller compared with that in the middle-aged and old groups. CONCLUSIONS...

  17. European national strategies to move towards very low energy buildings

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Thomsen, Kirsten Engelund

    high energy performance. It is important to stress the need for MS to introduce a national or regional definition of very low energy buildings in their building regulation and to develop a national strategy towards this level of energy performance to become the standard. This market transformation...... the ambition in the EU Action plan - to develop an EU strategy towards very low energy houses. The current recast of the EPBD is an opportunity, which must not be missed to introduce the requirement to MS to define very low energy buildings and a national strategy towards this level of energy performance....... A strategy for improved energy efficiency of existing buildings is a necessity if the energy consumption is to be reduced significantly over a limited period of time. The life time of buildings ranges from 50 to 100 years and improvement of the existing building stock will thus have much higher impact than...

  18. Nutrient adequacy of a very low-fat vegan diet.

    Science.gov (United States)

    Dunn-Emke, Stacey R; Weidner, Gerdi; Pettengill, Elaine B; Marlin, Ruth O; Chi, Christine; Ornish, Dean M

    2005-09-01

    This study assessed the nutrient adequacy of a very low-fat vegan diet. Thirty-nine men (mean age=65 years) with early stage prostate cancer who chose the "watchful waiting" approach to disease management, were instructed by a registered dietitian and a chef on following a very low-fat (10%) vegan diet with the addition of a fortified soy protein powdered beverage. Three-day food diaries, excluding vitamin and mineral supplements, were analyzed and nutrient values were compared against Dietary Reference Intakes (DRI). Mean dietary intake met the recommended DRIs. On the basis of the Adequate Intake standard, a less than adequate intake was observed for vitamin D. This demonstrates that a very low-fat vegan diet with comprehensive nutrition education emphasizing nutrient-fortified plant foods is nutritionally adequate, with the exception of vitamin D. Vitamin D supplementation, especially for those with limited sun exposure, can help assure nutritional adequacy.

  19. The Very High Risk Prostate Cancer – a Contemporary Update

    Science.gov (United States)

    Mano, Roy; Eastham, James; Yossepowitch, Ofer

    2017-01-01

    Background Treatment of high-risk prostate cancer has evolved considerably over the past two decades, yet patients with very high-risk features may still experience poor outcome despite aggressive therapy. We review the contemporary literature focusing on current definitions, role of modern imaging and treatment alternatives in very high-risk prostate cancer. Methods We searched the MEDLINE database for all clinical trials or practice guidelines published in English between 2000 – 2016 with the following search terms: ‘prostatic neoplasms’ (MeSH Terms) AND (‘high risk’ (keyword) OR ‘locally advanced’ (keyword) OR ‘node positive’ (keyword)). Abstracts pertaining to very high-risk prostate cancer were evaluated and 40 pertinent studies served as the basis for this review. Results The term ‘very’ high-risk prostate cancer remains ill defined. The EAU and NCCN guidelines provide the only available definitions, categorizing those with clinical stage T3-4 or minimal nodal involvement as very-high risk irrespective of PSA level or biopsy Gleason score. Modern imaging with mpMRI and PET-PSMA scans plays a role in pretreatment assessment. Local definitive therapy by external beam radiation combined with androgen deprivation is supported by several randomized clinical trials whereas the role of surgery in the very high-risk setting combined with adjuvant radiation/ androgen deprivation therapy is emerging. Growing evidence suggest neoadjuvant taxane based chemotherapy in the context of a multimodal approach may be beneficial. Conclusions Men with very high-risk tumors may benefit from local definitive treatment in the setting of a multimodal regimen, offering local control and possibly cure in well selected patients. Further studies are necessary to better characterize the ‘very’ high-risk category and determine the optimal therapy for the individual patient. PMID:27618950

  20. Very local interstellar spectra for galactic electrons, protons and helium

    Energy Technology Data Exchange (ETDEWEB)

    Potgieter, Marius S., E-mail: Marius.Potgieter@nwu.ac.za [Centre for Space Research, North-West University (South Africa)

    2014-07-01

    The local interstellar spectra (LIS) for cosmic rays at energies below ∼30 GeV/nuc are increasingly obscured from view at Earth by solar modulation, the lower the energy becomes. These charged particles encounter significant changes in the heliosphere, over an 11-year cycle, which include processes such as convection, diffusion, adiabatic energy losses and gradient, curvature and current sheet drifts. Particle drifts cause charge-sign-dependent modulation and a 22-year cycle, adding complexity to determining the respective very LIS from observations only at Earth. However, with measurements now made by the Voyager 1 spacecraft in the vicinity of the helio pause, it is possible to determine a very LIS for galactic electrons between ∼5 and ∼120 MeV. At these low energies, also galactic protons observed in the outer heliosphere had been completely obscured by the so-called anomalous component which is accelerated inside the helio sheath. Since August 2012, these anomalous cosmic rays are substantially depleted at Voyager 1 so that for cosmic ray ions, it is now possible to obtain a lower limit to their very LIS. Combining numerical modelling of solar modulation with the accurate measurements by the PAMELA mission and with Voyager observations, the lower limit of the very LIS for electrons, protons and helium and other ions can be determined from ∼5 MeV and above. These spectra are called helio pause spectra which is considered to be the lowest possible very LIS. Also, from an astrophysics point of view, the determination of what can be called a very LIS, not just an averaged galactic spectrum, is encouraging. The mentioned aspects are discussed, focusing on a comparison of recent heliospheric observations and corresponding solar modulation modelling. (author)

  1. Polarization of very cold neutron using a permanent magnet quadrupole

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Tamaki, E-mail: tyosioka@post.kek.j [High Energy Accelerator Research Organization, Ibaraki 305-0801 (Japan); Mishima, Kenji; Ino, Takashi; Taketani, Kaoru; Muto, Suguru; Morishima, Takahiro; Shimizu, Hirohiko M. [High Energy Accelerator Research Organization, Ibaraki 305-0801 (Japan); Oku, Takayuki; Suzuki, Junichi; Shinohara, Takenao; Sakai, Kenji [Japan Atomic Energy Agency, Ibaraki 319-1195 (Japan); Sato, Hiromi; Hirota, Katsuya; Otake, Yoshie [RIKEN, Saitama 351-0198 (Japan); Kitaguchi, Masaaki; Hino, Masahiro [Research Reactor Institute, Kyoto University, Osaka 590-0494 (Japan); Seki, Yoshichika [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Iwashita, Yoshihisa; Yamada, Masako [Institute for Chemical Research, Kyoto University, Kyoto 611-0011 (Japan); Ichikawa, Masahiro [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan)

    2011-04-01

    For the future fundamental physics experiments by using cold neutrons, we are developing a device which can measure the neutron polarization degree by accuracy significantly below 10{sup -3}. A quadrupole magnet is one of the promising candidate to measure the neutron polarization degree by such extremely high precision. We have performed a polarization experiment by using the quadrupole magnets at the Very Cold Neutron (VCN) port of the PF-2 in the Institute Laue-Langevin (ILL). As a result, we obtained the polarization degree P with very high accuracy P=0.9994{+-}0.0001(stat.){+-}0.0003(syst.), which meet our requirement significantly.

  2. Spirometry quality in adults with very severe lung function impairment.

    Science.gov (United States)

    Torre-Bouscoulet, Luis; Velázquez-Uncal, Mónica; García-Torrentera, Rogelio; Gochicoa-Rangel, Laura; Fernández-Plata, Rosario; Enright, Paul; Pérez-Padilla, Rogelio

    2015-05-01

    Some technologists worry that patients with very severe lung disease are unable to complete several spirometry maneuvers, which require considerable effort. We retrospectively selected all spirometry tests with an FEV1 30,000 subjects tested during the 3-y period) had adequate quality spirometry. Subjects with airway obstruction were less likely to meet FVC repeatability goals. A poor spirometry quality grade was associated with a very low FVC and a low body mass index, but not older age. Severe lung disease should not be used as an excuse for not meeting spirometry quality goals. Copyright © 2015 by Daedalus Enterprises.

  3. Very low energy scanning electron microscopy in nanotechnology

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Ilona; Hovorka, Miloš; Mika, Filip; Mikmeková, Eliška; Mikmeková, Šárka; Pokorná, Zuzana; Frank, Luděk

    2012-01-01

    Roč. 9, 8/9 (2012), s. 695-716 ISSN 1475-7435 R&D Projects: GA MŠk OE08012; GA MŠk ED0017/01/01; GA AV ČR IAA100650902 Institutional research plan: CEZ:AV0Z20650511 Keywords : scanning electron microscopy * very low energy electrons * cathode lens * grain contrast * strain contrast * imaging of participates * dopant contrast * very low energy STEM * graphene Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.087, year: 2012

  4. VeriClick: an efficient tool for table format verification

    Science.gov (United States)

    Nagy, George; Tamhankar, Mangesh

    2012-01-01

    The essential layout attributes of a visual table can be defined by the location of four critical grid cells. Although these critical cells can often be located by automated analysis, some means of human interaction is necessary for correcting residual errors. VeriClick is a macro-enabled spreadsheet interface that provides ground-truthing, confirmation, correction, and verification functions for CSV tables. All user actions are logged. Experimental results of seven subjects on one hundred tables suggest that VeriClick can provide a ten- to twenty-fold speedup over performing the same functions with standard spreadsheet editing commands.

  5. Very deep recurrent convolutional neural network for object recognition

    Science.gov (United States)

    Brahimi, Sourour; Ben Aoun, Najib; Ben Amar, Chokri

    2017-03-01

    In recent years, Computer vision has become a very active field. This field includes methods for processing, analyzing, and understanding images. The most challenging problems in computer vision are image classification and object recognition. This paper presents a new approach for object recognition task. This approach exploits the success of the Very Deep Convolutional Neural Network for object recognition. In fact, it improves the convolutional layers by adding recurrent connections. This proposed approach was evaluated on two object recognition benchmarks: Pascal VOC 2007 and CIFAR-10. The experimental results prove the efficiency of our method in comparison with the state of the art methods.

  6. Ultracold and very cold neutron facility in KUR

    International Nuclear Information System (INIS)

    Kawabata, Yuji; Utsuro, Masahiko

    1992-01-01

    The present status of the ultracold and very cold neutron facility installed in the Kyoto University Reactor (KUR) is described in this presentation. It consists of a VCN (very cold neutrons) guide tube, a VCN bender and a supermirror neutron turbine. The guide tube extracts VCN from a liquid deuterium cold neutron source in a graphite thermal column and the neutron turbine converts VCN to UCN (ultracold neutrons). As for the utilization of the present facility, VCN radiography and an UCN gravity spectrometer are shown for the practical examples of the research with VCN and UCN. (author)

  7. Executive Function in Very Preterm Children at Early School Age

    NARCIS (Netherlands)

    C.S.H. Aarnoudse-Moens (Cornelieke); D.P. Smidts (Diana); J. Oosterlaan (Jaap); H.J. Duivenvoorden (Hugo); N. Weisglas-Kuperus (Nynke)

    2009-01-01

    textabstractWe examined whether very preterm (≤30 weeks gestation) children at early school age have impairments in executive function (EF) independent of IQ and processing speed, and whether demographic and neonatal risk factors were associated with EF impairments. A consecutive sample of 50

  8. Talk about disposal for very low level waste

    International Nuclear Information System (INIS)

    Luo Shanggeng

    2008-01-01

    This paper describes the significance of segregation of very low level waste (VLLW), the current VLLW-definition and its limit value, and presents an introduction of four VLLW-disposing approaches operated world wide, as well as disposal of VLLW in China are also briefly discussed and suggested. (authors)

  9. Very early-onset schizophrenia with secondary onset tic disorder

    OpenAIRE

    Shilpa A Telgote; Shreyas Shrikant Pendharkar; Amol D Kelkar; Sachin Bhojane

    2017-01-01

    Very early-onset schizophrenia (defined as an onset of psychosis before 13 years of age) is a rare and severe form of the disorder which is clinically and neurobiologically continuous with the adult-onset disorder. It is rarely reported

  10. Very Early-onset Schizophrenia with Secondary Onset Tic Disorder.

    Science.gov (United States)

    Telgote, Shilpa A; Pendharkar, Shreyas Shrikant; Kelkar, Amol D; Bhojane, Sachin

    2017-01-01

    Very early-onset schizophrenia (defined as an onset of psychosis before 13 years of age) is a rare and severe form of the disorder which is clinically and neurobiologically continuous with the adult-onset disorder. It is rarely reported tic disorder.

  11. Path to Smoking Addiction Starts at Very Young Ages

    Science.gov (United States)

    THE PATH TO TOBACCO ADDICTION STARTS AT VERY YOUNG AGES Lifetime smoking and other tobacco use almost always begins by the time kids graduate from ... regular smoking, which typically turns into a strong addiction—well before the age of 18—that can ...

  12. Gaze Shift as an Interactional Resource for Very Young Children

    Science.gov (United States)

    Kidwell, Mardi

    2009-01-01

    This article examines how very young children in a day care center make use of their peers' gaze shifts to differentially locate and prepare for the possibility of a caregiver intervention during situations of their biting, hitting, pushing, and the like. At issue is how the visible character of a gaze shift--that is, the manner in which it is…

  13. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  14. Can NATO's new Very High Readiness Joint Task Force deter?

    DEFF Research Database (Denmark)

    Rynning, Sten; Ringsmose, Jens

    2017-01-01

    ” a distinct strategic rival – Russia. Chief among the Welsh summit initiatives was the decision to set up a new multinational spearhead force – the Very High Readiness Joint Task Force (VJTF) – as part of an enhanced NATO Response Force (NRF) and within the framework of a so-called Readiness Action Plan (RAP...

  15. Design and performance evaluation of very thin overlays in Texas.

    Science.gov (United States)

    2009-06-01

    Very thin overlays 1-inch thick or less were placed as surface layers on five major highways in Texas. : These mixes were designed in the laboratory to have a balance of good rut resistance as measured by : TxDOTs Hamburg Wheel Tracking test and g...

  16. Diagnostic Stability in Very Young Children with Autism Spectrum Disorders

    Science.gov (United States)

    Kleinman, Jamie M.; Ventola, Pamela E.; Pandey, Juhi; Verbalis, Alyssa D.; Barton, Marianne; Hodgson, Sarah; Green, James; Dumont-Mathieu, Thyde; Robins, Diana L.; Fein, Deborah

    2008-01-01

    Autism Spectrum Disorders (ASD) diagnosis in very young children may be delayed due to doubts about validity. In this study, 77 children received a diagnostic and developmental evaluation between 16 and 35 months and also between 42 and 82 months. Diagnoses based on clinical judgment, Childhood Autism Rating Scale, and the Autism Diagnostic…

  17. Effects of very low frequency electromagnetic method (VLFEM) and ...

    African Journals Online (AJOL)

    The study examined the impact of livestock dung on ground water status in the study area. To achieve this, a very low frequency EM survey was conducted; the aim and objective was to detect fractures in the subsurface. VLF data were acquired at 5m intervals along two profiles, with maximum length of 60m in the ...

  18. Daniel Day-Lewis - veri peab voolama / Kristiina Davidjants

    Index Scriptorium Estoniae

    Davidjants, Kristiina, 1974-

    2008-01-01

    Iiri-juudi näitleja Daniel Day-Lewis, kes võitis oma rolliga P.T. Andersoni filmis "Veri hakkab voolama" parima meespeaosatäitja Oscari. Tema põhjalikust tööst rollidega läbi tema filmiloomingu

  19. Biological effects of very low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Evseev, V.S.

    1987-01-01

    The paper deals with a qualitative microdosimetric analysis of a new radiobiological phenomenon (physiological reaction of the cell as a whole to very low doses of ionizing radiations). The analysis is aimed at identifying the type of the primary interaction of radiation with the cell and finding its place in the cell

  20. Very early disease manifestations of macular telangiectasia type 2

    NARCIS (Netherlands)

    Issa, P.C.; Heeren, T.F.C.; Kupitz, E.H.; Holz, F.G.; Berendschot, T.T.J.M.

    Background: To report very early morphologic and functional alterations in patients with macular telangiectasia type 2. Methods: Patients with asymmetric disease manifestations, in whom retinal alterations characteristic for macular telangiectasia type 2 were present in one but not in the apparently

  1. Radioenzymatic assay for trimethoprim in very small serum samples.

    OpenAIRE

    Yogev, R; Melick, C; Tan-Pong, L

    1985-01-01

    A modification of the methotrexate radioassay kit (supplied by New England Enzyme Center) enabled determination of trimethoprim levels in 5-microliter serum samples. An excellent correlation between this assay and high-pressure liquid chromatography assay was found. These preliminary results suggest that with this method rapid determination of trimethoprim levels in very small samples (5 to 10 microliters) can be achieved.

  2. Radioenzymatic assay for trimethoprim in very small serum samples

    International Nuclear Information System (INIS)

    Yogev, R.; Melick, C.; Tan-Pong, L.

    1985-01-01

    A modification of the methotrexate radioassay kit (supplied by New England Enzyme Center) enabled determination of trimethoprim levels in 5-microliter serum samples. An excellent correlation between this assay and high-pressure liquid chromatography assay was found. These preliminary results suggest that with this method rapid determination of trimethoprim levels in very small samples (5 to 10 microliters) can be achieved

  3. Antibiotic Therapy for Very Low Birth Weigh Newborns in NICU

    OpenAIRE

    Seyyed-Abolfazl Afjeh; Mohammad-Kazem Sabzehei; Seyyed-Ali-Reza Fahimzad; Farideh Shiva; Ahmad-Reza Shamshiri; Fatemeh Esmaili

    2016-01-01

    Background Prolonged empiric antibiotics therapy in neonates results in several adverse consequences including widespread antibiotic resistance, late onset sepsis (LOS), necrotizing enterocolitis (NEC), prolonged hospital course (HC) and increase in mortality rates. Objectives To assess the risk factors and the outcome of prolonged empiric antibiotic therapy in very low birth weight (VLBW) newborns. ...

  4. Ageing effects of polymers at very low dose-rates

    International Nuclear Information System (INIS)

    Chenion, J.; Armand, X.; Berthet, J.; Carlin, F.; Gaussens, G.; Le Meur, M.

    1987-10-01

    The equipment irradiation dose-rate into the containment is variable from 10 -6 to 10 -4 gray per second for the most exposed materials. During qualification, safety equipments are submitted in France to dose-rates around 0.28 gray per second. This study purpose is to now if a so large irradiation dose-rate increase is reasonable. Three elastomeric materials used in electrical cables, o'rings seals and connectors, are exposed to a very large dose-rates scale between 2.1.10 -4 and 1.4 gray per second, to 49 KGy dose. This work was carried out during 3.5 years. Oxygen consumption measurement of the air in contact with polymer materials, as mechanical properties measurement show that: - at very low dose-rate, oxygen consumption is maximum at the same time (1.4 year) for the three elastomeric samples. Also, mechanical properties simultaneously change with oxygen consumption. At very low dose-rate, for the low irradiation doses, oxygen consumption is at least 10 times more important that it is showed when irradiation is carried out with usual material qualification dose-rate. At very low dose-rate, oxygen consumption decreases when absorbed irradiation dose by samples increases. The polymer samples irradiation dose is not still sufficient (49 KGy) to certainly determine, for the three chosen polymer materials, the reasonable irradiation acceleration boundary during nuclear qualification tests [fr

  5. GUTs and supersymmetric GUTs in the very early universe

    International Nuclear Information System (INIS)

    Ellis, J.

    1983-01-01

    This talk is intended as background material for many of the other talks treating the possible applications of GUTs to the very early universe. It starts with a review of the present theoretical and phenomenological status of GUTs and then goes on to raise some new issues for their prospective cosmological applications which arise in supersymmetric (susy) GUTs. (author)

  6. Very-high-temperature reactors for future use

    International Nuclear Information System (INIS)

    Kasten, P.R.

    1988-01-01

    Very-High-Temperature Reactors (VHTRs) show promise for economic generation of electricity and of high-temperature process heat. The key is the development of high-temperature materials which permit gas turbine VHTRs to generate electricity economically, at helium temperatures which can be used for fossil fuel conversion processes. 7 refs., 5 figs

  7. Very-high-temperature reactors for future use

    International Nuclear Information System (INIS)

    Kasten, P.R.

    1988-08-01

    Very-high-temperature reactors (VHTRs) show promise for economic generation of electricity and of high-temperature process heat. The key is the development of high-temperature materials which permit gas turbine VHTRs to generate electricity economically, at reactor coolant temperatures which can be used for fossil fuel conversion processes. 7 refs., 5 figs

  8. Very short functionalized carbon nanotubes for membrane applications

    NARCIS (Netherlands)

    Fonseca, A.; Reijerkerk, Sander; Potreck, Jens; Nijmeijer, Dorothea C.; Mekhalif, Z.; Delhalle, J.

    2010-01-01

    The cutting and functionalization of carbon nanotubes is described, applying a single-step ball-mill based process. Very short carbon nanotubes bearing primary amine functions were produced, characterized and incorporated in polymeric membranes. The gas separation performance of the composite

  9. Tracking of Individuals in Very Long Video Sequences

    DEFF Research Database (Denmark)

    Fihl, Preben; Corlin, Rasmus; Park, Sangho

    2006-01-01

    In this paper we present an approach for automatically detecting and tracking humans in very long video sequences. The detection is based on background subtraction using a multi-mode Codeword method. We enhance this method both in terms of representation and in terms of automatically updating...

  10. Very light Higgs bosons in extended models at the LHC

    International Nuclear Information System (INIS)

    Belyaev, Alexander; Guedes, Renato; Santos, Rui; Moretti, Stefano

    2010-01-01

    The Large Electron-Positron (LEP) collider experiments have constrained the mass of the standard model (SM) Higgs boson to be above 114.4 GeV. This bound applies to all extensions of the SM where the coupling of a Higgs boson to the Z boson and also the Higgs decay profile do not differ much from the SM one. However, in scenarios with extended Higgs sectors, this coupling can be made very small by a suitable choice of the parameters of the model. In such cases, the lightest CP-even Higgs boson mass can in turn be made very small. Such a very light Higgs state, with a mass of the order of the Z boson one or even smaller, could have escaped detection at LEP. In this work we perform a detailed parton level study on the feasibility of the detection of such a very light Higgs particle at the Large Hadron Collider (LHC) in the production process pp→hj→τ + τ - j, where j is a resolved jet. We conclude that there are several models where such a Higgs state could be detected at the LHC with early data.

  11. Moments of inertia in 162Yb at very high spins

    International Nuclear Information System (INIS)

    Simon, R.S.; Banaschik, M.V.; Colombani, P.; Soroka, D.P.; Stephens, F.S.; Diamond, R.M.

    1976-01-01

    Two methods have been used to obtain values of the effective moment of inertia of very-high-spin (20h-bar--50h-bar) states populated in heavy-ion compound-nucleus reactions. The 162 Yb nucleus studied has effective moments of inertia smaller than, but approaching, the rigid-body estimate

  12. Acoustic MIMO communications in a very shallow water channel

    Science.gov (United States)

    Zhou, Yuehai; Cao, Xiuling; Tong, Feng

    2015-12-01

    Underwater acoustic channels pose significant difficulty for the development of high speed communication due to highly limited band-width as well as hostile multipath interference. Enlightened by rapid progress of multiple input multiple output (MIMO) technologies in wireless communication scenarios, MIMO systems offer a potential solution by enabling multiple spatially parallel communication channels to improve communication performance as well as capacity. For MIMO acoustic communications, deep sea channels offer substantial spatial diversity among multiple channels that can be exploited to address simultaneous multipath and co-channel interference. At the same time, there are increasing requirements for high speed underwater communication in very shallow water area (for example, a depth less than 10 m). In this paper, a space-time multichannel adaptive receiver consisting of multiple decision feedback equalizers (DFE) is adopted as the receiver for a very shallow water MIMO acoustic communication system. The performance of multichannel DFE receivers with relatively small number of receiving elements are analyzed and compared with that of the multichannel time reversal receiver to evaluate the impact of limited spatial diversity on multi-channel equalization and time reversal processing. The results of sea trials in a very shallow water channel are presented to demonstrate the feasibility of very shallow water MIMO acoustic communication.

  13. Spectroscopy of very neutron-deficient hafnium and tungsten isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Dracoulis, G D; Fabricius, B; Davidson, P M [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics; Macchiavelli, A O; Oliviera, J; Burde, J; Stephens, F; Deleplanque, M A [Lawrence Berkeley Lab., CA (United States)

    1992-08-01

    Level schemes of the very neutron-deficient isotopes {sup 158}Hf and {sup 162}W have been identified, and that for {sup 164}W extended. Alignment of the H{sub 9/2} neutrons is suggested. (author). 12 refs., 7 figs.

  14. Sacrificial wafer bonding for planarization after very deep etching

    NARCIS (Netherlands)

    Spiering, V.L.; Spiering, Vincent L.; Berenschot, Johan W.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

    A new technique is presented that provides planarization after a very deep etching step in silicon. This offers the possibility for as well resist spinning and layer patterning as realization of bridges or cantilevers across deep holes or grooves. The sacrificial wafer bonding technique contains a

  15. Introduction to the nuclear physics at very high energy

    International Nuclear Information System (INIS)

    Kodama, T.

    1985-01-01

    An introduction to the nuclear physics at very high energies on the basis of relativistic nucleus-nucleus, hadron-nucleus and hadron-hadron collisions is made. Some theoretical models used nowadays to explain the experimental data, such as Quantum Chromodynamics, String Model, etc... are presented. (L.C.) [pt

  16. How Google Web Search copes with very similar documents

    NARCIS (Netherlands)

    W. Mettrop (Wouter); P. Nieuwenhuysen; H. Smulders

    2006-01-01

    textabstractA significant portion of the computer files that carry documents, multimedia, programs etc. on the Web are identical or very similar to other files on the Web. How do search engines cope with this? Do they perform some kind of “deduplication”? How should users take into account that

  17. Sexual Behavior, Knowledge and Information Sources of Very ...

    African Journals Online (AJOL)

    Adolescents are a key target group for HIV and pregnancy prevention efforts, yet very little is known about the youngest adolescents: those under age 15. New survey data from 12-14 year olds in Burkina Faso, Ghana, Malawi and Uganda are used to describe their sexual activity, knowledge about HIV, STIs and pregnancy ...

  18. Patent Ductus Arteriosus Treatment in Very Preterm Infants

    DEFF Research Database (Denmark)

    Edstedt Bonamy, Anna-Karin; Gudmundsdottir, Anna; Maier, Rolf F

    2017-01-01

    BACKGROUND: Spontaneous closure of patent ductus arteriosus (PDA) occurs frequently in very preterm infants and despite the lack of evidence for treatment benefits, treatment for PDA is common in neonatal medicine. OBJECTIVES: The aim of this work was to study regional variations in PDA treatment...

  19. Quantitative proteomic assessment of very early cellular signaling events

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Olsen, Jesper V

    2007-01-01

    Technical limitations have prevented proteomic analyses of events occurring less than 30 s after signal initiation. We developed an automated, continuous quench-flow system allowing quantitative proteomic assessment of very early cellular signaling events (qPACE) with a time resolution of 1 s...

  20. IR wireless cluster synapses of HYDRA very large neural networks

    Science.gov (United States)

    Jannson, Tomasz; Forrester, Thomas

    2008-04-01

    RF/IR wireless (virtual) synapses are critical components of HYDRA (Hyper-Distributed Robotic Autonomy) neural networks, already discussed in two earlier papers. The HYDRA network has the potential to be very large, up to 10 11-neurons and 10 18-synapses, based on already established technologies (cellular RF telephony and IR-wireless LANs). It is organized into almost fully connected IR-wireless clusters. The HYDRA neurons and synapses are very flexible, simple, and low-cost. They can be modified into a broad variety of biologically-inspired brain-like computing capabilities. In this third paper, we focus on neural hardware in general, and on IR-wireless synapses in particular. Such synapses, based on LED/LD-connections, dominate the HYDRA neural cluster.

  1. Improved gamma spectrometry of very low level radioactive samples

    International Nuclear Information System (INIS)

    Pineira, T.H.

    1989-01-01

    Today, many laboratories face the need to perform measurements of very low level activities using gamma spectroscopy. The techniques in use are identical to those applicable for higher levels of activities, but there is a need to use better adapted materials and modify the measurement conditions to minimize the background noise around the area. This paper presents the design of a very low level activity laboratory which has addressed the laboratory itself, the measuring chamber and the detector. The lab is constructed underground using specially selected materials of construction. The lab atmosphere is filtered and recycled with frequent changeovers. The rate of make-up fresh air is reduced and is sampled high above ground and filtered

  2. Very Long Baseline Interferometry: Dependencies on Frequency Stability

    Science.gov (United States)

    Nothnagel, Axel; Nilsson, Tobias; Schuh, Harald

    2018-04-01

    Very Long Baseline Interferometry (VLBI) is a differential technique observing radiation of compact extra-galactic radio sources with pairs of radio telescopes. For these observations, the frequency standards at the telescopes need to have very high stability. In this article we discuss why this is, and we investigate exactly how precise the frequency standards need to be. Four areas where good clock performance is needed are considered: coherence, geodetic parameter estimation, correlator synchronization, and UT1 determination. We show that in order to ensure the highest accuracy of VLBI, stability similar to that of a hydrogen maser is needed for time-scales up to a few hours. In the article, we are considering both traditional VLBI where extra-galactic radio sources are observed, as well as observation of man-made artificial radio sources emitted by satellites or spacecrafts.

  3. Internal optical losses in very thin CW heterojunction laser diodes

    Science.gov (United States)

    Butler, J. K.; Kressel, H.; Ladany, I.

    1975-01-01

    Theoretical calculations are presented showing the relationship between the internal laser absorption and structural parameters appropriate for CW room-temperature lasers. These diodes have submicron-thick recombination regions, and very small spacings between the heat sink and the recombination region to minimize the thermal resistance. The optical loss is shown to be strongly dependent on the degree of radiation confinement to the active region. In particular, absorption in the surface GaAs layer providing the ohmic contact becomes very significant when the intermediate (AlGa)As layer is reduced below about 1 micron. It is further shown that excessive penetration into the GaAs regions gives rise to anomalies in the far-field radiation profiles in the direction perpendicular to the junction plane.

  4. Complementary installation for very low radioactive wastes in El Cabril

    International Nuclear Information System (INIS)

    Gregorio, S. de; Garcia Sierra, J.; Navarro, M.

    2006-01-01

    The Industry and Energy Commission of the Spanish Parliament in 1998, and the Economy and Treasury Commission in 2001 and 2002, approved both resolutions and demanded the govern to take the initiatives in the way to Spain will have capacity to store very low radioactive and low risk wastes, that can not be deals like conventional waste, in such a way that will not suppose a loss of the important strategic value that means the capacity of the actual vaults at El Cabril, Designed to disposed of radioactive waste in with high specific activity. The very low activity wastes are the part of waste with less activity in the whole low and intermediate level wastes. The complementary installation will form part, of the actual facility of El Cabril. The total activity to disposed of will be hold in the Reference Inventory allowed to the C. A. El Cabril, not being needed an extension of the actual inventory. (Author)

  5. Test of very fast kicker for TESLA damping ring

    International Nuclear Information System (INIS)

    Grishanov, B.I.; Podgorny, F.V.; Shiltsev, V.D.

    1997-04-01

    We describe a very fast kicker with unique combination of high repetition rate and short pulse width. Constructionally, the device is a symmetrical counter traveling wave stripline kicker fed by semiconductor high-voltage pulse generator. Experimentally tested kicker has a full pulse width of about 7 ns, 1.4 MHz repetition rate and maximum kick strength of the order of 3 G·m. Recent achievements in high-voltage semiconductor field-effect transistors (FET) technology and goal-specific optimization of the kicker parameters allow many-fold increase of the strength, and the kicker can be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications. 4 refs., 3 figs

  6. Very low-energy hydrogen-antihydrogen scattering

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Chamberlain, C.W.

    2003-01-01

    In view of current interest in the trapping of antihydrogen (H-bar) atoms at very low temperatures, we have carried out a calculation of s-wave hydrogen-antihydrogen scattering at very low energies, using the Kohn variational method, taking into account rearrangement scattering into the three channels that contain positronium in its ground state and lie closest to threshold. We find that our values for the elastic cross section are in good agreement with the values obtained by Jonsell et al. [2001 Phys. Rev. A 64 052712] using a distorted wave approximation. However, our values for the total rearrangement cross section are much larger than their values and we predict that cooling of H-bar by cold H would be considerably less efficient than was found to be the case by Jonsell et al.. (author)

  7. Management of very low-level radioactive waste

    International Nuclear Information System (INIS)

    Chapalain, E.; Damoy, J.; Joly, J.M.

    2003-01-01

    This document comprises 3 articles. The first article presents the concern of very low-level radioactive wastes generated in nuclear installations, the second article describes the management of the wastes issued from the dismantling operations of the ALS (linear accelerator of Saclay) and of the Saturn synchrotron both located in Saclay Cea's center. The last article presents the storage facility which is specifically dedicated to very low-level radioactive wastes. This storage facility, which is located at Morvilliers, near the 'Centre de l Aube' (used to store the low-, and medium-level, short-lived radioactive wastes), will receive the first packages next summer. Like the other storage facilities, it will be managed by ANDRA (national radioactive waste management agency)

  8. Morphological development of coasts at very oblique wave incidence

    DEFF Research Database (Denmark)

    Petersen, Dorthe Pia; Deigaard, Rolf; Fredsøe, Jørgen

    2003-01-01

    This study focuses on one distinct feature to be found on coasts exposed to a very oblique wave incidence, namely an accumulating spit. That is a spit where no retreat of the shoreline is going on along the spit. This requires a monotonically decreasing sediment transport capacity from the updrift...... that such a spit grows without changing its shape i.e. an equilibrium form emerge if the coast is exposed to a constant wave climate. During experiments conducted in a wave tank where a uniform stretch of coast was exposed to waves approaching at a very oblique angle an accumulating spit was formed at the down......-drift end of the coast. The spits approached equilibrium forms when constant wave climates were applied. The sediment transport around the spit has been investigated by two-dimensional models. The characteristic length scale for the equilibrium form depends linearly on the width of the surf zone...

  9. The potential for very high-frequency gravitational wave detection

    International Nuclear Information System (INIS)

    Cruise, A M

    2012-01-01

    The science case for observing gravitational waves at frequencies in the millihertz-kilohertz range using LIGO, VIRGO, GEO600 or LISA is very strong and the first results are expected at these frequencies. However, as gravitational wave astronomy progresses beyond the first detections, other frequency bands may be worth exploring. Early predictions of gravitational wave emission from discrete sources at very much higher frequencies (megahertz and above) have been published and more recent studies of cosmological signals from inflation, Kaluza-Klein modes from gravitational interactions in brane worlds and plasma instabilities surrounding violent astrophysical events, are all possible sources. This communication examines current observational possibilities and the detector technology required to make meaningful observations at these frequencies. (paper)

  10. IT Project Management in Very Small Software Companies

    DEFF Research Database (Denmark)

    Shakir, Shahid Nadeem; Nørbjerg, Jacob

    2013-01-01

    In developing countries very small software companies (VSSCs) with only 1-10 employees play an important role both in the local economy and as providers of software and services to customers in other parts of the world. Understanding and improving their IT project management (ITPM) practices...... and challenges are, therefore, important in the local as well as the larger context of globalized software development. There is, however, very little research into small shop software practices in developing countries. The current paper explores actual ITPM practices in Pakistani VSSCs based on a qualitative...... study of seven Pakistani VSSCs. We find that some Pakistani ITPM practices are similar to what is reported from VSSCs in other parts of the world, while others seem to be related to the companies' position in the global software development chain. This paper is part of a larger research project aiming...

  11. Magnetic behavior of VBr2 at very low temperatures

    International Nuclear Information System (INIS)

    Arthur, J.R.; Kawarazaki, S.; Hirakawa, K.

    1985-01-01

    Vanadium dibromide, along with VCl 2 and VI 2 , has a hexagonal crystal structure (CdI 2 structure) in which the magnetic coupling of vanadium ions within the c planes is much stronger than the interplane coupling. These systems are of interest as possible examples of highly frustrated two-dimensional triangular lattice antiferromagnets. This interest is encouraged by high-temperature magnetic susceptibility measurements, which yield Weiss constants of several hundred degrees Kelvin. In fact, magnetic transitions do not occur in these substances until temperatures of less than 50 K are reached, indicating that the antiferromagnetic interactions are frustrated. A search for possible new transitions at very low temperatures was conducted with a VBr 2 single-crystal sample mounted in the dilution refrigerator neutron diffraction facility at HFIR. The crystal was not of very good quality, but three distinct magnetic reflections were observed at 4.2 K and below

  12. Environment impact of a very low level waste specific landfill

    International Nuclear Information System (INIS)

    Brun-Yaba, C.; Peres, J.M.; Besnus, F.

    1996-01-01

    Operating enrichment plants, nuclear power plants and reprocessing plants and the decommissioning of nuclear facilities will give rise to large volumes of waste material (concrete, steel and others metals, technological wastes heat insulators...) and most of them, in term of quantities, will be categorized as very low level wastes. This paper deals with the environmental impact of a specific landfill as a final destination for the very low level radioactive waste (VLLW) with the aim of providing technical elements for safer workers practices during the operational and the monitoring phases and for a public occupation after closure of the site. This study has been made on the basis of inventories in terms of estimated quantities and spectra of the French VLLW for a set of scenarios which are representative of practices in a landfill. (author)

  13. Very-cold-neutron optics and interferometry at ILL

    International Nuclear Information System (INIS)

    Eder, K.; Zeilinger, A.; Gruber, M.; Rasel, E.; Gaehler, R.; Mampe, W.; Drexel, W.

    1994-01-01

    At the vertical neutron guide from the cold source of the Institut Laue-Langevin (ILL) an optical bench with vibration isolation has been installed. The beam of very cold neutrons has a nominal wavelength of 100 A. An interferometer using three transmission phase gratings sputter-etched into quartz glass plates has been developed. Extensive experiments on the diffraction of very cold neutrons at these large area gratings with grating constants d = 2 μm and d = 1 μm were carried out. The experimental results were compared with Fresnel-Kirchhoff calculations showing agreement in great detail. A prototype interferometer with an overall length of 50 cm has been tested for λ = 105 A (ν = 38.7 m/s) neutrons. Finally we list the experiments envisaged. (author)

  14. Sheath impedance effects in very high frequency plasma experiments

    International Nuclear Information System (INIS)

    Schwarzenbach, W.; Howling, A.A.; Fivaz, M.; Brunner, S.; Hollenstein, C.

    1995-05-01

    The frequency dependence (13.56 MHz to 70 MHz) of the ion energy distribution at the ground electrode was measured by mass spectrometry in a symmetrical capacitive argon discharge. Reduced sheath impedance at Very High Frequency allows high levels of plasma power and substrate ion flux whilst maintaining low levels of ion energy and electrode voltage. The lower limit of ion bombardment energy is fixed by the sheath floating potential at high frequency, in contrast to low frequencies where only the rf voltage amplitude is determinant. The capacitive sheaths are thinner at high frequencies which accentuates the high frequency reduction in sheath impedance. It is argued that the frequency dependence of sheath impedance is responsible for the principal characteristics of Very High Frequency plasmas. The measurements are summarised by simple physical descriptions and compared with a Particle-In-Cell simulation. (author) figs., tabs., refs

  15. Very low-excitation Herbig-Haro objects

    International Nuclear Information System (INIS)

    Boehm, K.H.; Brugel, E.W.; Mannery, E.

    1980-01-01

    Spectrophotometric observations show that H-H 7 and H-H 11 belong to a class of very low-excitation Herbig-Haro objects of which H-H 47 has been the only known example. Typical properties include line flux ratios [N I] (lambda5198+lambda5200)/Hβ and [S II] lambda/6717/Hα, which are both considerably larger than 1, very strong [O I] and [C I] lines, as well as relatively faint [O II] lines. So far no shock-wave models are available for these low-excitation objects. H-H 7 and H-H 11 have electron densities which are lower by about one order of magnitude, and electron temperatures which are slightly lower than those for high-excitation objects like H-H 1 and H-H 2. H-H 11 has a filling factor of about 1, much higher than other H-H objects

  16. Very high energy emission sources beyond the Galaxy

    Directory of Open Access Journals (Sweden)

    Sinitsyna V.G.

    2017-01-01

    Full Text Available Active Galactic Nuclei (AGN are considered as potential extragalactic sources of very and ultra high energy cosmic rays. According to theoretical predictions cosmic ray acceleration can take place at the shock created by the expanding cocoons around active galactic nuclei as well as at AGN jets. The measurements of AGN TeV spectra, the variability time scale of TeV emission can provide essential information on the dynamics of AGN jets, the localization of acceleration region and an estimation of its size. SHALON observations yielded data on extragalactic sources of different AGN types in the energy range of 800 GeV–100 TeV. The data from SHALON observations are compared with those from other experiments at high and very high energies.

  17. A Very Fast and Angular Momentum Conserving Tree Code

    International Nuclear Information System (INIS)

    Marcello, Dominic C.

    2017-01-01

    There are many methods used to compute the classical gravitational field in astrophysical simulation codes. With the exception of the typically impractical method of direct computation, none ensure conservation of angular momentum to machine precision. Under uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the very fast tree code) conserves linear momentum to machine precision. We show that it is possible to modify this method in a way that conserves both angular and linear momenta.

  18. A Very Fast and Angular Momentum Conserving Tree Code

    Energy Technology Data Exchange (ETDEWEB)

    Marcello, Dominic C., E-mail: dmarce504@gmail.com [Department of Physics and Astronomy, and Center for Computation and Technology Louisiana State University, Baton Rouge, LA 70803 (United States)

    2017-09-01

    There are many methods used to compute the classical gravitational field in astrophysical simulation codes. With the exception of the typically impractical method of direct computation, none ensure conservation of angular momentum to machine precision. Under uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the very fast tree code) conserves linear momentum to machine precision. We show that it is possible to modify this method in a way that conserves both angular and linear momenta.

  19. On the photosynthetic potential in the very Early Archean oceans.

    Science.gov (United States)

    Avila, Daile; Cardenas, Rolando; Martin, Osmel

    2013-02-01

    In this work we apply a mathematical model of photosynthesis to quantify the potential for photosynthetic life in the very Early Archean oceans. We assume the presence of oceanic blockers of ultraviolet radiation, specifically ferrous ions. For this scenario, our results suggest a potential for photosynthetic life greater than or similar to that in later eras/eons, such as the Late Archean and the current Phanerozoic eon.

  20. Cosmic very high-energy {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Plaga, R. [Max-Planck-Institut fur Physik, Muenchen (Germany)

    1998-12-31

    The article gives a brief overview, aimed at nonspecialists, about the goals and selected recent results of the detection of very-high energy {gamma}-rays (energies above 100 GeV) with ground based detectors. The stress is on the physics questions, specially the origin of Galactic Cosmic Rays and the emission of TeV {gamma}-radiation from active galaxies. Moreover some particle-physics questions which are addressed in this area are discussed.

  1. Very bright optical transient near the Trifid and Lagoon Nebulae

    Science.gov (United States)

    Dunsby, Peter

    2018-03-01

    Peter Dunsby (University of Cape Town) reports the detection of a very bright optical transient in the region between the Lagoon and Trifid Nebulae based on observations obtained from Cape Town on 20 March 2018, between 01:00 and 03:45 UT. The object was visible throughout the full duration of the observations and not seen when this field was observed previously (08 March 2018).

  2. γ*γ*->ρρ at very high energy

    International Nuclear Information System (INIS)

    Pire, B.; Szymanowski, L.; Wallon, S.

    2005-01-01

    The next generation of e + e - -colliders will offer a possibility of clean testing of QCD dynamics in the Regge limit. Recent progress in the theoretical description of exclusive processes permits for many of them a consistent use of the perturbative QCD methods. We advocate that the exclusive diffractive production of two ρ mesons from virtual photons at very high energies should be measurable at the future linear collider (LC)

  3. {gamma}*{gamma}*->{rho}{rho} at very high energy

    Energy Technology Data Exchange (ETDEWEB)

    Pire, B. [CPhT, Ecole Polytechnique, 91128 Palaiseau, France, UMR 7644 du CNRS (France); Szymanowski, L. [Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland) and Universite de Liege, B4000 Liege (Belgium); Wallon, S. [LPT, Universite d' Orsay, F 91405-Orsay (France); UMR 8627 du CNRS (France)

    2005-06-13

    The next generation of e{sup +}e{sup -}-colliders will offer a possibility of clean testing of QCD dynamics in the Regge limit. Recent progress in the theoretical description of exclusive processes permits for many of them a consistent use of the perturbative QCD methods. We advocate that the exclusive diffractive production of two {rho} mesons from virtual photons at very high energies should be measurable at the future linear collider (LC)

  4. Rational Suicide, Euthanasia, and the Very Old: Two Case Reports

    OpenAIRE

    Wand, Anne Pamela Frances; Peisah, Carmelle; Draper, Brian; Jones, Carolyn; Brodaty, Henry

    2016-01-01

    Suicide amongst the very old is an important public health issue. Little is known about why older people may express a wish to die or request euthanasia and how such thoughts may intersect with suicide attempts. Palliative care models promote best care as holistic and relieving suffering without hastening death in severely ill patients; but what of those old people who are tired of living and may have chronic symptoms, disability, and reduced quality of life? Two cases of older people who att...

  5. A condenser for very high power steam turbines

    International Nuclear Information System (INIS)

    Gardey, Robert.

    1973-01-01

    The invention relates to a condenser for very high power steam turbines under the masonry-block supporting the low-pressure stages of the turbine, that condenser comprises two horizontal aligned water-tube bundles passing through the steam-exhaust sleeves of the low-pressure stages, on both sides of a common inlet water box. The invention can be applied in particular to the 1000-2000 MW turbines of light water nuclear power stations [fr

  6. Observation of a very weak gamma ray burst

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; La Padula, C.; Polcaro, V.F.; Vialetto, G.

    1982-01-01

    In this paper we report the detection of a very faint burst detected in the hard X-ray range. The burst, having a peak intensity of approx.=7 x 10 - 9 erg/cm 2 s in the 20-120 KeV range has been detected by means two of the four detectors on board the HXR-81 balloon borne hard X-ray telescope (POKER) during a transmediterranean flight devoted to a sky survey. (orig./WL)

  7. Radiation hardness on very front-end for SPD

    International Nuclear Information System (INIS)

    Cano, Xavier; Graciani, Ricardo; Gascon, David; Garrido, Lluis; Bota, Sebastia; Herms, Atila; Comerma, Albert; Riera, Jordi

    2005-01-01

    The calorimeter front-end electronics of the LHCb experiment will be located in a region, which is not protected from radiation. Therefore, all the electronics must be qualified to stand some defined radiation levels. The procedure, measurements and results of an irradiation test for every component of the very front-end SPD detector, which is part of the LHCb calorimeter are presented here. All the tested components, except a custom made ASIC, are commercially available

  8. Development of a Very Dense Liquid Cooled Compute Platform

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Phillip N.; Lipp, Robert J.

    2013-12-10

    The objective of this project was to design and develop a prototype very energy efficient high density compute platform with 100% pumped refrigerant liquid cooling using commodity components and high volume manufacturing techniques. Testing at SLAC has indicated that we achieved a DCIE of 0.93 against our original goal of 0.85. This number includes both cooling and power supply and was achieved employing some of the highest wattage processors available.

  9. Formation of structures in the very early universe

    International Nuclear Information System (INIS)

    Bertolami Neto, O.; Marques, G.C.; Ventura, I.

    1984-01-01

    An alternative picture of cosmological phase transition is sketched and its implications to the formation of structures in the very early Universe is studied. It is shown that the condensation of walls at high temperatures leads to fluctuations which are in accordance to all necessary conditions to the formation of structures in the Universe. Furthermore the number of aglutination centers is roughly equal to the numbers of great structures observed in the Universe today. (Author) [pt

  10. A very high energy imaging for radioactive wastes processing

    International Nuclear Information System (INIS)

    Moulin, V.; Pettier, J.L.

    2004-01-01

    The X imaging occurs at a lot of steps of the radioactive wastes processing: selection for conditioning, physical characterization with a view to radiological characterization, quality control of the product before storage, transport or disposal. Size and volume of the objects considered here necessitate to work with very high energy systems. Here is shown, through some examples, in which conditions this X imaging is carried out as well as the contribution of the obtained images. (O.M.)

  11. An overview of PCI in the very elderly

    Science.gov (United States)

    Shanmugam, Vimalraj Bogana; Harper, Richard; Meredith, Ian; Malaiapan, Yuvaraj; Psaltis, Peter J

    2015-01-01

    Cardiovascular disease, and in particular ischemic heart disease (IHD), is a major cause of morbidity and mortality in the very elderly (> 80 years) worldwide. These patients represent a rapidly growing cohort presenting for percutaneous coronary intervention (PCI), now constituting more than one in five patients treated with PCI in real-world practice. Furthermore, they often have greater ischemic burden than their younger counterparts, suggesting that they have greater scope of benefit from coronary revascularization therapy. Despite this, the very elderly are frequently under-represented in clinical revascularization trials and historically there has been a degree of physician reluctance in referring them for PCI procedures, with perceptions of disappointing outcomes, low success and high complication rates. Several issues have contributed to this, including the tendency for older patients with IHD to present late, with atypical symptoms or non-diagnostic ECGs, and reservations regarding their procedural risk-to-benefit ratio, due to shorter life expectancy, presence of comorbidities and increased bleeding risk from antiplatelet and anticoagulation medications. However, advances in PCI technology and techniques over the past decade have led to better outcomes and lower risk of complications and the existing body of evidence now indicates that the very elderly actually derive more relative benefit from PCI than younger populations. Importantly, this applies to all PCI settings: elective, urgent and emergency. This review discusses the role of PCI in the very elderly presenting with chronic stable IHD, non ST-elevation acute coronary syndrome, and ST-elevation myocardial infarction. It also addresses the clinical challenges met when considering PCI in this cohort and the ongoing need for research and development to further improve outcomes in these challenging patients. PMID:25870621

  12. Novel Emplacement Device for a Very Deep Borehole Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Soo; Choi, Heui-joo; Lee, Jong Yul [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    There is a worldwide attempt of HLW disposal into a very deep borehole of around 3-5 km depth with the advancement of an underground excavation technology recently. As it goes into deeper underground, the rock becomes more uniform and flawless. And then the underground water circulation system at 3-5 km depth is almost disconnected with near groundwater circulation system. The canister integrity is less important in this very deep borehole disposal system unlike a general geologic disposal system at 500 m. In the deep borehole disposal procedures, one SNF (Spent Nuclear Fuel) assembly is stored in one disposal canister (D30-40cm, H4.7-5.0m), and approximately 10-40 disposal canisters are connected axially, which parade length can leach to around 200m in maximum. The connected canister parade is lowered through a very deep borehole (D40-50cm) by emplacement devices. Therefore the connections between canisters and canister to lowering joint are very important for the safe operation of it. The well-known connection method between canisters is Threaded Coupled Connection method, in which releasing of the connection is almost impossible after thread fastening in the borehole. The novel joint device suggested in this paper can accommodate a canister emplacement and retrieval in the borehole disposal process. The joint can be lowered by bound to a drilling pipe, or high tension cable along 3-5 km distance. This novel device can cope with an accidental event easily without any joint head change. When canisters are damaged or stuck on the borehole wall during their descending, the canisters in trouble can be retrieved simply by the control of a lifting speed.

  13. Physical activity, function, and longevity among the very old.

    Science.gov (United States)

    Stessman, Jochanan; Hammerman-Rozenberg, Robert; Cohen, Aaron; Ein-Mor, Eliana; Jacobs, Jeremy M

    2009-09-14

    Recommendations encouraging physical activity (PA) set no upper age limit, yet evidence supporting the benefits of PA among the very old is sparse. We examined the effects of continuing, increasing, or decreasing PA levels on survival, function, and health status among the very old. Mortality data from ages 70 to 88 years and health, comorbidity, and functional status at ages 70, 78, and 85 years were assessed through the Jerusalem Longitudinal Cohort Study (1990-2008). A representative sample of 1861 people born in 1920 and 1921 enrolled in this prospective study, resulting in 17 109 person-years of follow-up for all-cause mortality. Among physically active vs sedentary participants, respectively, at age 70, the 8-year mortality was 15.2% vs 27.2% (P activities of daily living at age 85 (odds ratio, 1.92; 95% confidence interval, 1.11-3.33). Among the very old, not only continuing but also initiating PA was associated with better survival and function. This finding supports the encouragement of PA into advanced old age.

  14. ELDRS Characterization for a Very High Dose Mission

    Science.gov (United States)

    Harris, Richard D.; McClure, Steven S.; Rax, Bernard G.; Kenna, Aaron J.; Thorbourn, Dennis O.; Clark, Karla B.; Yan, Tsun-Yee

    2010-01-01

    Evaluation of bipolar linear parts which may have Enhanced Low Dose Rate Sensitivity (ELDRS) is problematic for missions that have very high dose radiation requirements. The accepted standards for evaluating parts that display ELDRS require testing at a very low dose rate which could be prohibitively long for very high dose missions. In this work, a methodology for ELDRS characterization of bipolar parts for mission doses up to 1 Mrad(Si) is evaluated. The procedure employs an initial dose rate of 0.01 rad(Si)/s to a total dose of 50 krad(Si) and then changes to 0.04 rad(Si)/s to a total dose of 1 Mrad(Si). This procedure appears to work well. No change in rate of degradation with dose has been observed when the dose rate is changed from 0.01 to 0.04 rad(Si)/s. This is taken as an indication that the degradation due to the higher dose rate is equivalent to that at the lower dose rate at the higher dose levels, at least for the parts studied to date. In several cases, significant parameter degradation or functional failure not observed at HDR was observed at fairly high total doses (50 to 250 krad(Si)) at LDR. This behavior calls into question the use of dose rate trend data and enhancement factors to predict LDR performance.

  15. Metabolism of cholesteryl esters of rat very low density lipoproteins.

    Science.gov (United States)

    Faergeman, O; Havel, R J

    1975-06-01

    Rat very low density lipoproteins (d smaller than 1.006), biologically labeled in esterified and free cholesterol, were obtained form serum 6 h after intravenous injection of particulate (3-H) cholesterol. When injected into recipient animals, the esterified cholesterol was cleared form plasma with a half-life of 5 min. After 15 min, 71% of the injected esterified (3-H) cholesterol had been taken up by the liver, where it was rapidly hydrolyzed. After 60 min only 3.3% of the amount injected had been transferred, via lipoproteins of intermediate density, to the low density lipoproteins of plasma (d 1.019-1.063). Both uptake in the liver and transfer to low density lipoproteins occurred without change of distribution of 3-H in the various cholesteryl esters. 3-H appearing in esterified cholesterol of high density lipoproteins (d greater than 1.063) was derived from esterification, presumably by lecithin: cholesterol acyltransferase, of simultaneously injected free (3-H) cholesterol. Content of free (3-H) cholesterol in the very low density lipoproteins used for injection could be reduced substantially by incubation with erythrocytes. This procedure, however, increased the rate of clearance of the lipoproteins after injection into recipient rats. These studies show that hepatic removal is the major catabolic pathway for cholesteryl esters of rat very low density lipoproteins and that transfer to low density lipoproteins occurs to only a minor extent.

  16. Very extended shpaes in the A ∼ 150 mass region

    International Nuclear Information System (INIS)

    Chasman, R.R.

    1995-01-01

    There was a report of a rotational band in 152 Dy or 153 Dy that is characterized by a dynamic moment of inertia of 130h 2 MeV -1 . For purposes of orientation, it should be noted that the well known superdeformed bands in this region are characterized by moments of inertia of ∼90. Some calculations were carried out in two- and three-dimensional shape spaces, in order to understand this experimental observation. These calculations show either very shallow minima and/or minima that do not become yrast below I = 90 at the very large deformations that would seem to be required to explain such a large moment of inertia. We extended our four-dimensional deformation space Strutinsky calculations to a study of this mass region, with the hope of gaining some insight into the nature of this band. We are also analyzing the other nuclides of this mass region with the hope of finding other instances of such very extended shapes. This analysis is almost complete

  17. Chaotic Traversal (CHAT): Very Large Graphs Traversal Using Chaotic Dynamics

    Science.gov (United States)

    Changaival, Boonyarit; Rosalie, Martin; Danoy, Grégoire; Lavangnananda, Kittichai; Bouvry, Pascal

    2017-12-01

    Graph Traversal algorithms can find their applications in various fields such as routing problems, natural language processing or even database querying. The exploration can be considered as a first stepping stone into knowledge extraction from the graph which is now a popular topic. Classical solutions such as Breadth First Search (BFS) and Depth First Search (DFS) require huge amounts of memory for exploring very large graphs. In this research, we present a novel memoryless graph traversal algorithm, Chaotic Traversal (CHAT) which integrates chaotic dynamics to traverse large unknown graphs via the Lozi map and the Rössler system. To compare various dynamics effects on our algorithm, we present an original way to perform the exploration of a parameter space using a bifurcation diagram with respect to the topological structure of attractors. The resulting algorithm is an efficient and nonresource demanding algorithm, and is therefore very suitable for partial traversal of very large and/or unknown environment graphs. CHAT performance using Lozi map is proven superior than the, commonly known, Random Walk, in terms of number of nodes visited (coverage percentage) and computation time where the environment is unknown and memory usage is restricted.

  18. FASTING IN COUNTRIES WHERE THE DAY IS VERY LONG OR VERY SHORT: A Study of Muslims in the Netherlands

    Directory of Open Access Journals (Sweden)

    Ahmad Najib Burhani

    2013-07-01

    Full Text Available Ramadan falls both during winter and autumn months, when the days are cool and short, and spring and summer months, when the days are long and hot. Fasting in areas where the climate is extremely hot and the day is more than twenty hours is a double hardship that can be a dangerous assault on physical condition. In contrast to that, fasting in areas where the day is very short is, to some extent, like an interval between breakfast and lunch or between lunch and dinner. This article, therefore, intends to discover how Muslims in the countries where the day is either very long or very short deal with the problem of the fasting time. This research is based on the practices of some Muslims in the Netherlands with a variety of countries of origin. This article attempts to answer the following questions: How did they manage their fasting time in the summer or when the day is very long? How did they manage their fasting time in the winter or when the day is very short? What kind of fiqh book or fatwa did they use as reference? Did they think that fasting obligation was dangerous for their health when the day was very long?   [Bulan Ramadan bisa tiba pada musim dingin dan musim gugur, ketika siang hari pendek dan sejuk, tapi Ramadan juga bisa tiba pada musim semi dan musim panas, ketika siang hari sangat panjang dan panas. Puasa di tempat yang sangat panas dan dengan panjang siang hari lebih dari dua puluh jam adalah beban yang berat dan bisa berbahaya bagi kondisi fisik pelakunya. Sebaliknya, puasa di tempat yang siang harinya sangat pendek terasa tak seperti puasa karena ia hanya seperti interval antara makan pagi dan makan siang atau antara makan siang dan makan malam. Tulisan ini didasarkan pada penelitian terhadap praktik berpuasa orang-orang Islam di Belanda dari berbagai negara asal. Pertanyaan yang ingin dijawab dalam tulisan ini adalah: Bagaimana umat Islam Belanda melaksanakan puasa pada musim panas atau ketika siang hari teramat panjang

  19. Respiratory morbidity in very preterm and very low birth weight infants: the first 2 years of life

    Directory of Open Access Journals (Sweden)

    Mariana Ferreira

    2014-06-01

    Full Text Available Respiratory morbidity in the first two years of life, including recurrent symptoms and frequent hospitalizations, is a common problem in very preterm and very low birth weight (VLBW infants. We conducted a retrospective cohort study aiming to describe the respiratory morbidity at 2 years of corrected age for very preterm and VLBW infants and to identify potential risk factors for its development in a Portuguese based population born in a tertiary referral center between 2009 and 2011. Data were collected from patient’s clinical files and using a standardized questionnaire-based clinical interview for parents. A total 59 children were included. Thirteen (22.0% had recurrent respiratory symptoms and 12 (20.3% were using chronic respiratory medication. Health care utilization for respiratory causes was frequent (57.6%, particularly emergency department attendance (50.8%. Twenty seven (45.8% had additional outpatient visits for respiratory causes and hospital admission was necessary for 8 (13.6% patients. Factors associated with increased recurrent respiratory symptoms included maternal hypertensive disorders during pregnancy, umbilical artery flow disturbances, being small for gestational age, bronchopulmonary dysplasia, retinopathy of prematurity, intraventricular hemorrhage and a weight percentile below 3 at 6, 12 and 24 months of corrected age. Premature rupture of membranes was negatively associated with respiratory morbidity. Respiratory morbidity at 2 years of age is a common problem in very preterm and VLBW children from our population. Several perinatal and developmental risk factors were identified for respiratory morbidity. Further studies are needed to clarify the importance of these factors, as they can lead to changes in healthcare guidelines.

  20. Very Low Birthweight: Dysregulated gestation versus evolutionary adaptation

    Science.gov (United States)

    Catalano, Ralph; Karasek, Deborah; Gemmill, Alison; Falconi, April; Goodman, Julia; Magganas, Aristotle; Hartig, Terry

    2015-01-01

    Much medical literature attributes persistently high rates of very low birthweight (VLBW) to “dysregulated” gestation. We offer the alternative view that natural selection conserved well-regulated, though nonconscious, decisional biology that protects the reproductive fitness of women by spontaneously aborting gestations that would otherwise yield frail infants, particularly small males. Modern obstetric practice, however, converts some fraction of these erstwhile spontaneous abortions into live births of very small infants. We further propose that the nonconscious decisional biology of gestation exhibits preferences also seen in consciously made decisions. We hypothesize that the incidence of VLBW among male infants should vary with the population's self-reported intentions to assume financial risk. We apply time-series modeling to monthly birth counts by sex and weight from the Swedish Medical Birth Registry between January 1993 and December 2010. We gauge risk aversion with monthly data from the Micro Index of the Swedish Consumer Tendency Survey (MISCT). Consistent with our argument that nonconscious decisional biology shares risk aversion with conscious decisions, we find that the incidence of VLBW among male infants in Sweden varies with the population's self-reported intentions to assume financial risk. We find increases above expected odds of a very low weight infant among males born 1 month after increases above expected levels of self-reported risk aversion in the Swedish population. We offer this finding as support for the argument that persistently high rates of VLBW arise, at least in part, from a combination of medical interventions and mechanisms conserved by natural selection to protect reproductive fitness. PMID:24593927

  1. On relative velocity in very young asteroid families

    Science.gov (United States)

    Rosaev, A.; Plávalová, E.

    2018-04-01

    Asteroid families are groups of minor planets that have a common origin in catastrophic breakup events. The very young compact asteroid clusters are a natural laboratory in which to study impact processes and the dynamics of asteroid orbits. In the first part of the paper, we define the term very young asteroid families (VYF), that is to say, younger than 1.6 Myrs, and explain why we have defined this group as being separate from young families (younger than 100 Myr), due to specific characteristics, in particularly, non-gravitational forces which have a very small effect (which could be negligible) on their dynamics and the role of the initial conditions in VYFs as being more significant. Due to these facts, the way we study VYFs may be different relative to young families. For the most part, the calculation of VYFs' normal component of relative velocity using backward numerical integration, exhibited a clear, deep minimum, which was close to the breakup epoch. The age estimations found while employing this method were in excellent agreement with the established age estimations used by other authors. We confirmed our results with the established age estimation of the Hobson family (365 ± 67 kyrs). Concerning the Emilkowalsky family, we confirmed the results of Nesvorný and Vokrouhlický (2006) (220 ± 30 kyrs), obtaining a far clearer result using the relative velocity method rather than single-orbital element convergence. The case of the Datura family is more complex to study, mainly due to its 9:16 resonance with Mars. We have exemplified that the z-component of relative velocity may prove to be a powerful and useful criterion for VYF age estimations. The studied value of relative velocity may contain information about the ejection velocity. As an additional outcome of this paper, we have introduced two new members of two different VYFs; one new member of the Emilkowalsky family and one of the Hobson family.

  2. Variability of intensive care admission decisions for the very elderly.

    Directory of Open Access Journals (Sweden)

    Ariane Boumendil

    Full Text Available Although increasing numbers of very elderly patients are requiring intensive care, few large sample studies have investigated ICU admission of very elderly patients. Data on pre triage by physicians from other specialities is limited. This observational cohort study aims at examining inter-hospital variability of ICU admission rates and its association with patients' outcomes. All patients over 80 years possibly qualifying for ICU admission who presented to the emergency departments (ED of 15 hospitals in the Paris (France area during a one-year period were prospectively included in the study. Main outcome measures were ICU eligibility, as assessed by the ED and ICU physicians; in-hospital mortality; and vital and functional status 6 months after the ED visit. 2646 patients (median age 86; interquartile range 83-91 were included in the study. 94% of participants completed follow-up (n = 2495. 12.4% (n = 329 of participants were deemed eligible for ICU admission by ED physicians and intensivists. The overall in-hospital and 6-month mortality rates were respectively 27.2% (n = 717 and 50.7% (n = 1264. At six months, 57.5% (n = 1433 of patients had died or had a functional deterioration. Rates of patients deemed eligible for ICU admission ranged from 5.6% to 38.8% across the participating centers, and this variability persisted after adjustment for patients' characteristics. Despite this variability, we found no association between level of ICU eligibility and either in-hospital death or six-month death or functional deterioration. In France, the likelihood that a very elderly person will be admitted to an ICU varies widely from one hospital to another. Influence of intensive care admission on patients' outcome remains unclear.ClinicalTrials.gov NCT00912600.

  3. Neural correlates of executive attention in adults born very preterm

    Directory of Open Access Journals (Sweden)

    Marcel Daamen

    2015-01-01

    Full Text Available Very preterm birth is associated with an increased prevalence of attention problems and may especially impair executive attention, i.e., top-down control of attentional selection in situations where distracting information interferes with the processing of task-relevant stimuli. While there are initial findings linking structural brain alterations in preterm-born individuals with attention problems, the functional basis of these problems are not well understood. The present study used an fMRI adaptation of the Attentional Network Test to examine the neural correlates of executive attention in a large sample of N = 86 adults born very preterm and/or with very low birth weight (VP/VLBW, and N = 100 term-born controls. Executive attention was measured by comparing task behavior and brain activations associated with the processing of incongruent vs. congruent arrow flanker stimuli. Consistent with subtle impairments of executive attention, the VP/VLBW group showed lower accuracy and a tendency for increased response times during the processing of incongruent stimuli. Both groups showed similar activation patters, especially within expected fronto-cingulo-parietal areas, but no significant between-group differences. Our results argue for a maintained attention-relevant network organization in high-functioning preterm born adults in spite of subtle deficits in executive attention. Gestational age and neonatal treatment variables showed associations with task behavior, and brain activation in the dorsal ACC and lateral occipital areas, suggesting that the degree of prematurity (and related neonatal complications has subtle modulatory influences on executive attention processing.

  4. Chinese very small aperture terminal system for ministries

    Science.gov (United States)

    Dan, Sen

    The objective and technologic approach of the Chinese very small aperture terminal (VSAT) system of data communications is described in this paper. The system is primarily designed for the management business of many governmental ministries and administrations. It consists of a centralized processing and switching facility and a number of groups of remote terminals. The network is constructed in a star configuration because of simplicity and the inherent nature of the management business. Either Intelsat of Chinese domestic communications satellite can be used for the space segment. The system performance has been verified by field trials. Some results of system analysis can be used for traffic design.

  5. Brown dwarf accretion: Nonconventional star formation over very long timescales

    Directory of Open Access Journals (Sweden)

    Ćirković Milan M.

    2005-01-01

    Full Text Available We investigate the process of accretion of interstellar gas by the Galactic population of brown dwarfs over very long timescales typical for physical eschatology. In particular, we use the classical Hoyle-Lyttleton-Bondi accretion model to investigate the rate at which brown dwarfs collect enough additional mass to become red dwarfs, accretion-induced changes in the mass function of the low- mass objects, and the corresponding accretion heating of brown dwarfs. In addition, we show how we can make the definition of the final mass function for stellar objects more precise.

  6. Image-converter streak cameras with very high gain

    International Nuclear Information System (INIS)

    1975-01-01

    A new camera is described with slit scanning and very high photonic gain (G=5000). Development of the technology of tubes and microchannel plates has enabled integration of such an amplifying element in an image converter tube which does away with the couplings and the intermediary electron-photon-electron conversions of the classical converter systems having external amplification. It is thus possible to obtain equal or superior performance while retaining considerable gain for the camera, great compactness, great flexibility in use, and easy handling. (author)

  7. Fast-slow coincidence systems with very high time resolution

    International Nuclear Information System (INIS)

    Naday, I.; Kajcsos, Zs.; Kozma, Gy.; Kanyo, M.

    1981-02-01

    The measuring of very short times has recently become increasingly important. In this paper the authors describe their studies on the various parts of a timing system in an attempt to improve its parameters. The detector system, i.e. the transit time differences of the photomultipliers, the construction of the divider network, the various types of timing discriminators, the time-to-pulse height converters and the gating system were investigated. Two types of constant fraction discriminators are introduced: one for general timing applications, the other placed inside the detector head for positron lifetime measurements. (author)

  8. Can NATO's new very high readiness joint task force deter?

    DEFF Research Database (Denmark)

    Rynning, Sten; Ringsmose, Jens

    2017-01-01

    When NATO-allies met at their Wales summit in September 2014, the D-word was back in vogue. Not in a muttering, shy or implicit way, but unambiguously and straightforward. For the first time in more than two decades NATO’s heads of states and governments openly discussed how best to “deter......” a distinct strategic rival – Russia. Chief among the Welsh summit initiatives was the decision to set up a new multinational spearhead force – the Very High Readiness Joint Task Force (VJTF) – as part of an enhanced NATO Response Force (NRF) and within the framework of a so-called Readiness Action Plan (RAP...

  9. Aube very low activity waste storage Centre. Annual report 2009

    International Nuclear Information System (INIS)

    2010-01-01

    After a presentation of the ANDRA (the French national agency for radioactive waste management), its role and missions, its sites, its strategy with respect to a sustainable development, this report contains a description of waste storage installations and key figures of the activity in 2009 (origin and nature of very low activity wastes, brief description of the Aube centre installations, stored volumes, performed works). It describes arrangements related to security, safety and radioprotection, presents results of the radiological survey activity performed in the environment and on wastes, and activities related to public information

  10. The Very Large Hadron Collider: The farthest energy frontier

    International Nuclear Information System (INIS)

    Barletta, William A.

    2001-01-01

    The Very Large Hadron Collider (or Eloisatron) represents what may well be the final step on the energy frontier of accelerator-based high energy physics. While an extremely high luminosity proton collider at 100-200 TeV center of mass energy can probably be built in one step with LHC technology, that machine would cost more than what is presently politically acceptable. This talk summarizes the strategies of collider design including staged deployment, comparison with electron-positron colliders, opportunities for major innovation, and the technical challenges of reducing costs to manageable proportions. It also presents the priorities for relevant R and D for the next few years

  11. Spectrum from the Proposed BNL Very Long Baseline Neutrino Facility

    CERN Document Server

    Kahn, S A

    2005-01-01

    This paper calculates the neutrino flux that would be seen at the far detector location from the proposed BNL Very Long Baseline Neutrino Facility. The far detector is assumed to be located at an underground facility in South Dakota 2540 km from BNL. The neutrino beam facility uses a 1 MW upgraded AGS to provide an intense proton beam on the target and a magnetic horn to focus the secondary pion beam. The paper will examine the sensitivity of the neutrino flux at the far detector to the positioning of the horn and target so as to establish alignment tolerances for the neutrino system.

  12. Review of very low level radioactive waste disposal

    International Nuclear Information System (INIS)

    Wang Jinsheng; Guo Minli; Tian Hao; Teng Yanguo

    2005-01-01

    Very low level waste (VLLW) is a new type of radioactive wastes proposed recently. No widely acceptable definition and disposal rules have been established for it. This paper reviews the definition of VLLW in some countries where VLLW was researched early, as well as the disposal policies and methods of VLLW that the IAEA and these countries followed. In addition, the safety assessment programs for VLLW disposal are introduced. It is proved the research of VLLW is urgent and essential in china through the comparison of VLLW disposal between china and these counties. At last, this paper points out the future development of VLLW disposal research in China. (authors)

  13. Flexible riser global analysis for very shallow water

    OpenAIRE

    Karegar, Sadjad

    2013-01-01

    Master's thesis in Offshore technology Flexible risers are widely used for a range of water depths and can accommodate large floater motions when using a buoyant system. A wide range of buoyancy solutions have been developed for very shallow water (e.g. 30-50 m), shallow water (e.g. 90-110 m) and semi-deep water (e.g. 300-400 m) and in the ranges between these depths. Flexible risers can have different configurations. These different solutions have different characteristics which influe...

  14. Commissioning of the very low level radioactive waste disposal facility

    International Nuclear Information System (INIS)

    2003-08-01

    This press kit presents the solution retained by the French national agency of radioactive wastes (ANDRA) for the management of very low level radioactive wastes. These wastes mainly come from the dismantling of decommissioned nuclear facilities and also from other industries (chemical, metal and other industries). The storage concept is a sub-surface disposal facility (Morvilliers center, Aube) with a clay barrier and a synthetic membrane system. The regulatory framework, and the details of the licensing, of the commissioning and of the environment monitoring are recalled. The detailed planing of the project and some exploitation data are given. (J.S.)

  15. Batched Triangular DLA for Very Small Matrices on GPUs

    KAUST Repository

    Charara, Ali

    2017-03-13

    In several scientific applications, like tensor contractions in deep learning computation or data compression in hierarchical low rank matrix approximation, the bulk of computation typically resides in performing thousands of independent dense linear algebra operations on very small matrix sizes (usually less than 100). Batched dense linear algebra kernels are becoming ubiquitous for such scientific computations. Within a single API call, these kernels are capable of simultaneously launching a large number of similar matrix computations, removing the expensive overhead of multiple API calls while increasing the utilization of the underlying hardware.

  16. Critical behaviour in very pure Ni-Ta systems

    International Nuclear Information System (INIS)

    Oddou, J.L.; Berthier, J.; Peretto, P.

    1978-01-01

    The authors use the perturbed angular correlation technique to follow the behaviour of the magnetic hyperfine field on 181 Ta in nickel in the critical region of the matrix. Contrary to what is expected, it is observed that the critical exponent associated to the hyperfine field is different from the critical exponent associated to the bulk magnetization. Because the concentrations of the various impurities are very low, the authors think that the explanation of the phenomenon is to be found in the framework of a one-impurity model interacting with the surrounding spins via an isotropic exchange energy

  17. Very high energy probes of the quark-gluon plasma

    International Nuclear Information System (INIS)

    Ludlam, T.; Paige, F.; Madansky, L.

    1984-01-01

    Among the penetrating probes of nuclear matter the most frequently discussed have been those which involve the detection of photons or leptons with m/sub T/ approx. = P/sub T/ < 3 GeV. This is the expected range of emission from a hot, thermalized plasma of quarks and gluons. The suggestion has been made that in very high energy collisions of nuclei the properties of high P/sub T/ jets may also reflect the characteristics of the nuclear medium through which the parent partons have propagated just after the collision. In this note we expand on the possible uses of such a probe

  18. Very high pressure Moessbauer spectroscopy using diamond anvil cells

    International Nuclear Information System (INIS)

    Pasternak, M.P.; Taylor, R.D.

    1988-01-01

    The technique of generating very high pressure by means of Diamond Anvil Cells (DAC) for Mossbauer Effect applications is outlined. A comprehensive description is presented of the principles of DAC, modification for the use in M/umlt o/ssbauer Spectroscopy (MS), the Merrill--Bassett and Bassett cells, of pressure measurements, of gasketing and collimation, and of hydrostatic media. Examples of 151 Eu, 119 Sn and 129 I are given showing the feasibility of DAC applications in MS. Other isotopes with potential use for high pressure MS using DAC are suggested. 27 refs., 9 figs

  19. Reliable pipeline repair system for very large pipe size

    Energy Technology Data Exchange (ETDEWEB)

    Charalambides, John N.; Sousa, Alexandre Barreto de [Oceaneering International, Inc., Houston, TX (United States)

    2004-07-01

    The oil and gas industry worldwide has been mainly depending on the long-term reliability of rigid pipelines to ensure the transportation of hydrocarbons, crude oil, gas, fuel, etc. Many other methods are also utilized onshore and offshore (e.g. flexible lines, FPSO's, etc.), but when it comes to the underwater transportation of very high volumes of oil and gas, the industry commonly uses large size rigid pipelines (i.e. steel pipes). Oil and gas operators learned to depend on the long-lasting integrity of these very large pipelines and many times they forget or disregard that even steel pipelines degrade over time and more often that that, they are also susceptible to various forms of damage (minor or major, environmental or external, etc.). Over the recent years the industry had recognized the need of implementing an 'emergency repair plan' to account for such unforeseen events and the oil and gas operators have become 'smarter' by being 'pro-active' in order to ensure 'flow assurance'. When we consider very large diameter steel pipelines such as 42' and 48' nominal pipe size (NPS), the industry worldwide does not provide 'ready-made', 'off-the-shelf' repair hardware that can be easily shipped to the offshore location and effect a major repair within acceptable time frames and avoid substantial profit losses due to 'down-time' in production. The typical time required to establish a solid repair system for large pipe diameters could be as long as six or more months (depending on the availability of raw materials). This paper will present in detail the Emergency Pipeline Repair Systems (EPRS) that Oceaneering successfully designed, manufactured, tested and provided to two major oil and gas operators, located in two different continents (Gulf of Mexico, U.S.A. and Arabian Gulf, U.A.E.), for two different very large pipe sizes (42'' and 48'' Nominal Pipe Sizes

  20. Transurethral resection of very large prostates. A retrospective study

    DEFF Research Database (Denmark)

    Waaddegaard, P; Hansen, B J; Christensen, S W

    1991-01-01

    Twenty-one patients with benign prostatic hypertrophy (BPH), and a weight of transurethrally resected tissue exceeding 80 g (Group 1), were compared to a control group of 30 patients with a weight of resected tissue less than 80 g (Group 2) with regard to the peri- and postoperative course...... resections performed had a longer operating time and a greater perioperative blood loss than the group of minor resections. No differences were found with regard to other peri- or postoperative complications or subjective results. Transurethral resection is safe and efficient in treating BPH, also with very...

  1. On the Ongoing Evolution of Very High Frequency Power Supplies

    DEFF Research Database (Denmark)

    Knott, Arnold; Andersen, Toke Meyer; Kamby, Peter

    2013-01-01

    The ongoing demand for smaller and lighter power supplies is driving the motivation to increase the switching frequencies of power converters. Drastic increases however come along with new challenges, namely the increase of switching losses in all components. The application of power circuits used...... in radio frequency transmission equipment helps to overcome those. However those circuits were not designed to meet the same requirements as power converters. This paper summarizes the contributions in recent years in application of very high frequency (VHF) technologies in power electronics, describes...

  2. The history of astronomy a very short introduction

    CERN Document Server

    Hoskin, Michael

    2003-01-01

    The History of Astronomy: A Very Short Introduction traces the history of Western astronomy, from prehistoric times to the origins of astrophysics in the mid-nineteenth century and the technical developments since the Second World War. Astronomy, perhaps the first of the sciences, was already well developed by the time of Christ — the arithmetical astronomy of the Babylonians was merged with the Greek geometrical approach. This legacy was transmitted to the West via Islam and led to the Copernican revolution, which in turn led to Kepler and Newton, who provided the principles on which the exploration of the solar system and the stars continued in the eighteenth- and nineteenth centuries.

  3. Origin of very-short orbital-period binary systems

    International Nuclear Information System (INIS)

    Miyaji, S.

    1983-01-01

    Recent observations of four close binaries have established that there is a group of very-short orbital-period (VSOP) binaries whose orbital periods are less than 60 minutes. The VSOP binaries consist of both X-ray close binaries and cataclysmic variables. Their orbital periods are too short to have a main-sequence companion. However, four binaries, none of which belongs to any globular cluster, are too abundant to be explained by the capturing mechanism of a white dwarf. Therefore it seemed to be worthwhile to present an evolutionary scenario from an original binary system which can be applied for all VSOP binaries. (Auth.)

  4. A Computer Based Moire Technique To Measure Very Small Displacements

    Science.gov (United States)

    Sciammarella, Cesar A.; Amadshahi, Mansour A.; Subbaraman, B.

    1987-02-01

    The accuracy that can be achieved in the measurement of very small displacements in techniques such as moire, holography and speckle is limited by the noise inherent to the utilized optical devices. To reduce the noise to signal ratio, the moire method can be utilized. Two system of carrier fringes are introduced, an initial system before the load is applied and a final system when the load is applied. The moire pattern of these two systems contains the sought displacement information and the noise common to the two patterns is eliminated. The whole process is performed by a computer on digitized versions of the patterns. Examples of application are given.

  5. Very Bright CV discovered by MASTER-ICATE (Argentina)

    Science.gov (United States)

    Saffe, C.; Levato, H.; Mallamaci, C.; Lopez, C.; Lipunov, F. Podest V.; Denisenko, D.; Gorbovskoy, E.; Tiurina, N.; Balanutsa, P.; Kornilov, V.; Belinski, A.; Shatskiy, N.; Chazov, V.; Kuznetsov, A.; Yecheistov, V.; Yurkov, V.; Sergienko, Y.; Varda, D.; Sinyakov, E.; Gabovich, A.; Ivanov, K.; Yazev, S.; Budnev, N.; Konstantinov, E.; Chuvalaev, O.; Poleshchuk, V.; Gress, O.; Frolova, A.; Krushinsky, V.; Zalozhnih, I.; Popov, A.; Bourdanov, A.; Parkhomenko, A.; Tlatov, A.; Dormidontov, D.; Senik, V.; Podvorotny, P.; Shumkov, V.; Shurpakov, S.

    2013-06-01

    MASTER-ICATE very wide-field camera (d=72mm f/1.2 lens + 11 Mpix CCD) located near San Juan, Argentina has discovered OT source at (RA, Dec) = 14h 20m 23.5s -48d 55m 40s on the combined image (exposure 275 sec) taken on 2013-06-08.048 UT. The OT unfiltered magnitude is 12.1m (limit 13.1m). There is no minor planet at this place. The OT is seen in more than 10 images starting from 2013-06-02.967 UT (275 sec exposure) when it was first detected at 12.4m.

  6. New helium sniffing device for locating very fine leaks

    International Nuclear Information System (INIS)

    Murakami, Y.; Shimomura, Y.; Abe, T.; Obara, K.

    1984-01-01

    A new helium sniffing method for leak checking large vacuum vessels is described. The low sensitivity problem of the conventional helium sniffing method has been overcome by increasing the gas draw rate from around leaks into the detector up to about 0.1 Pa m 3 /s. The devised system consists of a flexible stainless steel capillary tube 0.6 mm i.d. and 10 m long, a sorption pump using molecular sieve, and a helium leak detector in series. This method is particularly useful for locating very fine leaks down to 10 -11 Pa m 3 /s. Relevant theoretical considerations and experimental results are presented

  7. Very-high-level neutral-beam control system

    International Nuclear Information System (INIS)

    Elischer, V.; Jacobson, V.; Theil, E.

    1981-10-01

    As increasing numbers of neutral beams are added to fusion machines, their operation can consume a significant fraction of a facility's total resources. LBL has developed a very high level control system that allows a neutral beam injector to be treated as a black box with just 2 controls: one to set the beam power and one to set the pulse duration. This 2 knob view allows simple operation and provides a natural base for implementing even higher level controls such as automatic source conditioning

  8. The development of a very high stability electrostatic generator (1962)

    International Nuclear Information System (INIS)

    Jonckheere, R.E.L.

    1962-01-01

    This thesis deals with the study of an electrostatic high voltage generator having a voltage stability of the order of 10 -6 per minute. This equipment should be very useful in electron microscopy. The electrostatic generator is studied as a control system element: transfer function, parasitic signals and noise are determined and a mathematical model is proposed. A theoretical study of the open loop transfer function, stability, transient response, voltage stabilization of five different control systems shows which one should be able to fulfill the requirements There follows a detailed study of drift, a description of the actual system and performance data. (author) [fr

  9. The Very Local Universe in X-Rays

    Science.gov (United States)

    Ptak, A.

    2011-01-01

    There are many open questions in X-ray observations of the Galactic neighborhood and nearby galaxies, such as the properties of the hot ISM and accreting sources, the X-ray/star-formation rate correlation and how the X-ray luminosity function of starburst galaxies. We discuss how these would be addressed by very wide-area (> 100 sq. deg.) X-ray surveys and upcoming X-ray missions. In particular planned NuStar observations of the Galaxy and nearby galaxies will be highlighted.

  10. Spill response trade-offs in a very large spill

    International Nuclear Information System (INIS)

    Schulze, R.

    1990-01-01

    This paper examines the physical limitaions on spill encounter rate and how these limitaions affect the are that can be covered in spill response. Since mechanical recovery devices may not be able to cover the affected area in a large spill, in situ burning must be considered as a response option. Further, effective recovered oil logistics is essential to successful response operations and keeping skimmers operating. A successful spill response effort in a very large oil spill often depends on: Prompt response, Skimmer encounter rate, Making a decision for in situ burning, Recovered oil logistics

  11. Very high cycle fatigue testing of concrete using ultrasonic cycling

    Energy Technology Data Exchange (ETDEWEB)

    Karr, Ulrike; Schuller, Reinhard; Fitzka, Michael; Mayer, Herwig [Univ. of Natural Resources and Life Sciences, Vienna (Austria). Inst. of Physics and Materials Science; Denk, Andreas; Strauss, Alfred [Univ. of Natural Resources and Life Sciences, Vienna (Austria)

    2017-06-01

    The ultrasonic fatigue testing method has been further developed to perform cyclic compression tests with concrete. Cylindrical specimens vibrate in resonance at a frequency of approximately 20 kHz with superimposed compressive static loads. The high testing frequency allows time-saving investigations in the very high cycle fatigue regime. Fatigue tests were carried out on ''Concrete 1'' (compressive strength f{sub c} = 80 MPa) and ''Concrete 2'' (f{sub c} = 107 MPa) under purely compressive loading conditions. Experiments at maximum compressive stresses of 0.44 f{sub c} (Concrete 1) and 0.38 f{sub c} (Concrete 2) delivered specimen failures above 109 cycles, indicating that no fatigue limit exists for concrete below one billion load cycles. Resonance frequency, power required to resonate the specimen and second order harmonics of the vibration are used to monitor fatigue damage in situ. Specimens were scanned by X-ray computed tomography prior to and after testing. Fatigue cracks were produced by ultrasonic cycling in the very high cycle fatigue regime at interfaces of grains as well as in cement. The possibilities as well as limitations of ultrasonic fatigue testing of concrete are discussed.

  12. The very low level radioactive military waste in France

    International Nuclear Information System (INIS)

    2005-01-01

    The recommendations of the Observatory of French nuclear weapons call attention to the fact the I.N.B.S. depend on the services of the High Commissioner of Atomic Energy;call attention to the fact that the reactors of the nuclear propulsion ( only military ones) are out of regulation: independent studies have to be realised on three harbors (Brest, Toulon, Cherbourg) for an evaluation about the environmental and sanitary consequences of the presence of nuclear facilities near urban areas that is not the case for any civil nuclear installation; call attention on the dismantling operations actually in some military nuclear installations, who is in charge of the control of the different steps of these dismantling operations, call attention on the setting up of radioactive waste storage ( very low activity at Saint-Priest, Rhone, very high activity with americium at Valduc, long lived elements at Cadarache, tritium waste at Valduc, alpha waste at Valduc waste not under the control of an independent organism; call attention on the final destination of depleted uranium; call attention on the bad management of tritium by the installation of nuclear weapons fabrication, about the actual stocks in plutonium and uranium. (N.C.)

  13. VOLUME BASED DTM GENERATION FROM VERY HIGH RESOLUTION PHOTOGRAMMETRIC DSMS

    Directory of Open Access Journals (Sweden)

    B. Piltz

    2016-06-01

    Full Text Available In this paper we propose a new algorithm for digital terrain (DTM model reconstruction from very high spatial resolution digital surface models (DSMs. It represents a combination of multi-directional filtering with a new metric which we call normalized volume above ground to create an above-ground mask containing buildings and elevated vegetation. This mask can be used to interpolate a ground-only DTM. The presented algorithm works fully automatically, requiring only the processing parameters minimum height and maximum width in metric units. Since slope and breaklines are not decisive criteria, low and smooth and even very extensive flat objects are recognized and masked. The algorithm was developed with the goal to generate the normalized DSM for automatic 3D building reconstruction and works reliably also in environments with distinct hillsides or terrace-shaped terrain where conventional methods would fail. A quantitative comparison with the ISPRS data sets Potsdam and Vaihingen show that 98-99% of all building data points are identified and can be removed, while enough ground data points (~66% are kept to be able to reconstruct the ground surface. Additionally, we discuss the concept of size dependent height thresholds and present an efficient scheme for pyramidal processing of data sets reducing time complexity to linear to the number of pixels, O(WH.

  14. A VERY LARGE GLITCH IN PSR B2334+61

    International Nuclear Information System (INIS)

    Yuan, J. P.; Wang, N.; Zhou, X.; Liu, Z. Y.; Gao, Z. F.; Manchester, R. N.

    2010-01-01

    Seven year pulse time-of-arrival measurements have been collected from observations of the young pulsar PSR B2334+61 using the Nanshan radio telescope of Urumqi Observatory. A phase-connected solution has been obtained over the whole data span, 2002 August to 2009 August. This includes a very large glitch that occurred between 2005 August 26 and September 8 (MJDs 53608 and 53621). The relative increase in rotational frequency for this glitch, Δν g /ν ∼ 20.5 x 10 -6 , is the largest ever seen. Although accounting for less than 1% of the glitch, there were two well-defined exponential decay terms with time constants of 21 and 147 days, respectively. There was also a large long-term increase in the spin-down rate with Δν-dit p /ν-dot ∼0.011 at the time of the glitch. A highly significant oscillation with a period of close to one year is seen in the post-glitch residuals. It is very unlikely that this can be accounted for by a pulsar position error or proper motion-it appears to result from effects interior to the neutron star. Implications of these results for pulsar glitch models are discussed.

  15. A very large leiomyoma of the urethra: a case report.

    Science.gov (United States)

    Fedelini, Paolo; Chiancone, Francesco; Fedelini, Maurizio; Fabiano, Marco; Persico, Francesco; Di Lorenzo, Domenico; Meccariello, Clemente

    2017-02-28

    Leiomyomas are benign mesenchymal tumours of smooth muscle origin. They are the most common uterine masses in women of reproductive age group and may be related to the hormonal status. Urethral leiomyomas are very rare. According to the literature, the mean diameter of the urethral leiomyomas is 3.7 cm. We report a case of a very large leiomyoma of the urethra. A 40-year-old women woman was admitted to our department for a giant vaginal mass. She complained of haematuria, dysuria, recurrent urinary tract infections and dyspareunia. The physical evaluation demonstrated a 6 × 5.5 cm neoformation involving the distal tract of the urethra. The patient underwent an ultrasonography and then a magnetic resonance that suggested the diagnosis of leiomyoma. The neoformation was excised through a suburethral incision. The patient was discharged after 3 days and no intraoperative and postoperative complications occurred. The Foley catheter was removed after a week. The patient was continent to urine, and at 6 months follow-up, the patient was symptom free and no recurrences occurred.

  16. Internal optical losses in very thin cw heterojunction laser diodes

    International Nuclear Information System (INIS)

    Butler, J.K.; Kressel, H.; Ladany, I.

    1975-01-01

    Theoretical calculations are presented showing the relationship between the internal laser absorption and structural parameters appropriate for cw room-temperature lasers. These diodes have submicron-thick recombination regions, and very small spacings between the heat sink and the recombination region to minimize the thermal resistance. The optical loss is shown to be strongly dependent on the degree of radiation confinement to the active region. In particular, absorption in the surface GaAs layer providing the ohmic contact becomes very significant when the intermediate (AlGa)As layer is reduced below about 1 μm. It is further shown that excessive penetration into the GaAs regions gives rise to anomalies in the far-field radiation profiles in the direction perpendicular to the junction plane. Proper design of the internal structure of the laser avoids large increases of the threshold current density as well as large decreases in the external differential quantum efficiency from interaction with the contact layer. The design curves presented can be used to predict the gain required at threshold for a broad range of structural parameters of interest in low-threshold laser design

  17. A probabilistic consequence assessment for a very high temperature reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joeun; Kim, Jintae; Jae, Moosung [Hanyang Univ., Seoul (Korea, Republic of). Dept. of Nuclear Engineering

    2017-02-15

    Currently, fossil fuel is globally running out. If current trends continue, crude oil will be depleted in 20 years and natural gas in 40 years. In addition, the use of fossil resource has increased emissions of green gas such as carbon dioxide. Therefore, there has been a strong demand in recent years for producing large amounts of hydrogen as an alternative energy [1]. To generate hydrogen energy, very high temperature more than 900 C is required but this level is not easy to reach. Because a Very High Temperature Reactor (VHTR), one of next generation reactor, is able to make the temperature, it is regarded as a solution of the problem. Also, VHTR has an excellent safety in comparison with existing and other next generation reactors. Especially, a passive system, Reactor Cavity Cooling System (RCCS), is adopted to get rid of radiant heat in case of accidents. To achieve variety requirements of new designed-reactors, however, it needs to develop new methodologies and definitions different with existing method. At the same time, an application of probability safety assessment (PSA) has been proposed to ensure the safety of next generation NPPs. For this, risk-informed designs of structures have to be developed and verified. Particularly, the passive system requires to be evaluated for its reliability. The objective of this study is to improve safety of VIITR by conducting risk profile.

  18. Et nationalt studie af bankrøveri

    DEFF Research Database (Denmark)

    Hansen, Maj; Elklit, Ask

    11,1 % (n = 41) af ASD og seks måneder efter røveriet led 6,2 % (n = 23) af PTSD. Begge prævalenser var begrænset af kravet om undgåelsessymptomer (ASD uden undgåelse: 14 %, PTSD uden undgåelse: 17,8 %), men ASD diagnosen var især begrænset af kravet om dissociationssymptomer (ASD uden dissociation......: 26,7 %). Hierarkisk regressionsanalyse viste, at 51 % af variansen i PTSD sværhedsgrad blev forklaret af peritraumatisk dissociation, ASD sværhedsgrad, emotionel coping og negative tanker om egen person og evner. ASD sværhedsgrad var den stærkeste prædiktorer for PTSD sværhedsgrad og forudsagde alene...... diagnoser. Særligt ASD sværhedsgrad og negative tanker om egen person og evner synes at kunne forudsige PTSD sværhedsgrad efter bankrøveri. Det anbefales derfor, at ”Acute Stress Disorder Scale” anvendes til at screene for PTSD efter bankrøveri. Fremtidig forskning anbefales at fokusere på udvikling af...

  19. Very Late-Onset Friedreich Ataxia with Laryngeal Dystonia

    Directory of Open Access Journals (Sweden)

    Silvia Rota

    2014-12-01

    Full Text Available Friedreich ataxia (FRDA is an autosomal recessive neurodegenerative disorder characterized by progressive gait and limb ataxia, cerebellar, pyramidal and dorsal column involvement, visual defects, scoliosis, pes cavus and cardiomyopathy. It is caused by a homozygous guanine-adenine-adenine (GAA trinucleotide repeat expansion in intron 1 of the frataxin gene (FXN on chromosome 9q13-q21.1. Onset is usually in the first or second decade of life; however, late-onset cases of Freidreich ataxia (LOFA, after the age of 25 years, and very late-onset cases of Freidreich ataxia (VLOFA, after the age of 40 years, have been reported. VLOFA is quite rare and usually presents a milder progression of the disease. We report the case of a 64-year-old woman affected with VLOFA whose first symptoms (balance and gait disturbances occurred at the age of 44 years. At the age of 62 years, she started complaining of a slowly progressive dysphonia showing the clinical aspects of laryngeal dystonia. Molecular analysis showed a 210- and 230-trinucleotide GAA repeat expansion in the two alleles of the FXN gene. Laryngeal dystonia has been reported only in very few cases of ataxia syndrome and never before in FRDA patients. It may represent a rare clinical manifestation of VLOFA thus confirming the high variability of the clinical spectrum of FRDA.

  20. Impact of maternal obesity on very preterm infants.

    Science.gov (United States)

    Khalak, Rubia; Rijhsinghani, Asha; McCallum, Sarah E

    2017-05-01

    Infants born at less than  34 weeks' gestational age are at higher risk for morbidity and mortality. Data are limited on the impact of maternal obesity on the very preterm infant. This study reviewed whether maternal obesity further increases the intensive care needs of very preterm infants of less than 34 weeks' gestation. Maternal and neonatal data for live-born singleton births of 23 0/7 to 33 6/7 weeks' gestation delivering in upstate New York were reviewed. BMI categorization followed the National Institutes of Health BMI classification that subdivides obesity into three ascending BMI groups. Records were obtained on 1,224 women, of whom 31.6% were classified with obesity. Despite similar mean gestational age (31 to 31.6 weeks, P = 0.57) and birth weight (1,488 to 1,569 g, P = 0.51) of the infants in the BMI categories, delivery room (DR) resuscitation was more common for infants of women with level III obesity (63.2%, P = 0.04) with a trend toward the continued need for assisted ventilation (54.7%, P = 0.06). Preterm infants of women with level III obesity were more likely to require DR resuscitation with a trend to continued need for ventilatory support beyond 6 hours of age. This could impact utilization of DR resources at delivering hospitals. © 2017 The Obesity Society.

  1. On the very long term delayed behavior of concrete

    International Nuclear Information System (INIS)

    Torrenti, J.M.; Benboudjema, F.; Barre, F.; Gallitre, E.

    2015-01-01

    The prediction of very long-term deformation of prestressed concrete structures is a major challenge considering the service life of these structures. It is therefore necessary to correctly model the delayed behavior of these structures. Using a review of laboratory tests and observations of the delayed behavior of structures (bridges and nuclear power plants), the main conclusions of this work are the following ones. First, very long term creep in laboratory or of real structures seems to be non asymptotic. In the actual Eurocode-2, creep is calculated by means of an asymptotic hyperbolic function while in the recent Model Code 2010 creep is expressed as a combination of an asymptotic and a logarithmic functions. In the latter case the logarithmic function corresponds to basic creep while drying creep is asymptotic. Secondly, using a long test (3 years) in a laboratory is not enough to assess the long term behaviour of a massive structure. We need physical relations for creep in codes in order to predict the delayed behavior of massive structures. Thirdly, the biaxial creep of nuclear power plant could be modelled but using data of the structure itself. This would allow to predict the delayed behavior of these structures. Further work is needed to improve the prediction in the design phase

  2. CONSTRAINTS ON VERY HIGH ENERGY EMISSION FROM GRB 130427A

    International Nuclear Information System (INIS)

    Aliu, E.; Errando, M.; Aune, T.; Barnacka, A.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Benbow, W.; Cerruti, M.; Berger, K.; Biteau, J.; Byrum, K.; Cardenzana, J. V; Dickinson, H. J.; Eisch, J. D.; Chen, X.; Ciupik, L.; Connaughton, V.; Cui, W.; Falcone, A.

    2014-01-01

    Prompt emission from the very fluent and nearby (z = 0.34) gamma-ray burst GRB 130427A was detected by several orbiting telescopes and by ground-based, wide-field-of-view optical transient monitors. Apart from the intensity and proximity of this GRB, it is exceptional due to the extremely long-lived high-energy (100 MeV to 100 GeV) gamma-ray emission, which was detected by the Large Area Telescope on the Fermi Gamma-Ray Space Telescope for ∼70 ks after the initial burst. The persistent, hard-spectrum, high-energy emission suggests that the highest-energy gamma rays may have been produced via synchrotron self-Compton processes though there is also evidence that the high-energy emission may instead be an extension of the synchrotron spectrum. VERITAS, a ground-based imaging atmospheric Cherenkov telescope array, began follow-up observations of GRB 130427A ∼71 ks (∼20 hr) after the onset of the burst. The GRB was not detected with VERITAS; however, the high elevation of the observations, coupled with the low redshift of the GRB, make VERITAS a very sensitive probe of the emission from GRB 130427A for E > 100 GeV. The non-detection and consequent upper limit derived place constraints on the synchrotron self-Compton model of high-energy gamma-ray emission from this burst

  3. Motion of a Janus particle very near a wall

    Science.gov (United States)

    Rashidi, Aidin; Wirth, Christopher L.

    2017-12-01

    This article describes the simulated Brownian motion of a sphere comprising hemispheres of unequal zeta potential (i.e., "Janus" particle) very near a wall. The simulation tool was developed and used to assist in the methodology development for applying Total Internal Reflection Microscopy (TIRM) to anisotropic particles. Simulations of the trajectory of a Janus sphere with cap density matching that of the base particle very near a boundary were used to construct 3D potential energy landscapes that were subsequently used to infer particle and solution properties, as would be done in a TIRM measurement. Results showed that the potential energy landscape of a Janus sphere has a transition region at the location of the boundary between the two Janus halves, which depended on the relative zeta potential magnitude. The potential energy landscape was fit to accurately obtain the zeta potential of each hemisphere, particle size, minimum potential energy position and electrolyte concentration, or Debye length. We also determined the appropriate orientation bin size and regimes over which the potential energy landscape should be fit to obtain system properties. Our simulations showed that an experiment may require more than 106 observations to obtain a suitable potential energy landscape as a consequence of the multivariable nature of observations for an anisotropic particle. These results illustrate important considerations for conducting TIRM for anisotropic particles.

  4. The Next-Generation Very Large Array: Technical Overview

    Science.gov (United States)

    McKinnon, Mark; Selina, Rob

    2018-01-01

    As part of its mandate as a national observatory, the NRAO is looking toward the long range future of radio astronomy and fostering the long term growth of the US astronomical community. NRAO has sponsored a series of science and technical community meetings to consider the science mission and design of a next-generation Very Large Array (ngVLA), building on the legacies of the Atacama Large Millimeter/submillimeter Array (ALMA) and the Very Large Array (VLA).The basic ngVLA design emerging from these discussions is an interferometric array with approximately ten times the sensitivity and ten times higher spatial resolution than the VLA and ALMA radio telescopes, optimized for operation in the wavelength range 0.3cm to 3cm. The ngVLA would open a new window on the Universe through ultra-sensitive imaging of thermal line and continuum emission down to milli-arcsecond resolution, as well as unprecedented broadband continuum polarimetric imaging of non-thermal processes. The specifications and concepts for major ngVLA system elements are rapidly converging.We will provide an overview of the current system design of the ngVLA. The concepts for major system elements such as the antenna, receiving electronics, and central signal processing will be presented. We will also describe the major development activities that are presently underway to advance the design.

  5. VeriTainer radiation detector for intermodal shipping containers

    International Nuclear Information System (INIS)

    Redus, R.H.; Alioto, M.; Sperry, D.; Pantazis, T.

    2007-01-01

    The VeriSpreader TM radiation detection system will monitor every container passing through a shipping terminal without impeding the flow of commerce by making the radiation measurements during normal container handling. This is accomplished by integrating neutron and spectroscopic γ-ray detectors into a container crane spreader bar, the part of the crane that directly engages the intermodal shipping containers while moving from ship to shore and vice versa. The use of a spectroscopic γ-detector reduces the rate of nuisance alarms due to naturally occurring radioactive material (NORM). The combination of γ and neutron detection reduces the effectiveness of shielding and countermeasures. The challenges in this spreader bar-based approach arise from the harsh environment, particularly the mechanical shock and the vibration of the moving spreader bar, since the measurement is taken while the container is moving. The electrical interfaces in the port environment, from the crane to a central monitoring office, present further challenges. It is the packaging, electronic interfaces, and data processing software that distinguish this system, which is based on conventional radiation sensors. The core of the system is Amptek's GAMMA-RAD, which integrates a ruggedized scintillator/PMT, digital pulse shaping electronics, electronics for the neutron detector, power supplies, and an Ethernet interface. The design of the VeriTainer system and results from both the laboratory and a proof-of-concept test at the Port of Oakland, California will be presented

  6. Neonatal morbidity and early outcome of very preterm infants

    Directory of Open Access Journals (Sweden)

    Heljić Suada

    2013-03-01

    Full Text Available Background: Although the mortality rate for preterm infants and the gestational age-specific mortality rate have dramatically improved over the last 3 to 4 decades, infants born preterm remain vulnerable to many complications, including respiratory distress syndrome, chronic lung disease, necrotizing enterocolitis, a compromised immune system, cardiovascular disorders, hearing and vision problems, and brain lesions. The aim is to determine mortality and morbidity rates and selected outcome variables for preterm infant’s grade 3 IVH or PVL 16.6%, NEC Bell stages II or III 9.8%, BPD 25/72 (33.3% of infants who survived to 36 weeks postmenstrual age. In 38 (37.2% infants, episodes of infections were noticed (one or more episodes in 25 infants, half of them were caused by Gram positive bacteria, most frequent coagulasa negative staphylococci. Klebsiella pneumoniae was the most frequent organism among Gram negative bacteria. One patient had invasive candidiasis caused by Candida albicans. In 5 infants (4.9% early onset of sepsis was documented. Conclusion: Very preterm infants remain very vulnerable group of population, and interventions to reduce the morbidity and mortality of preterm babies include tertiary interventions such as regionalized care, transportation in uterus, and treatment with antenatal steroids.

  7. Study of 235U very asymmetric thermal fission

    International Nuclear Information System (INIS)

    Sida, J.L.

    1989-12-01

    The fission fragment separator Lohengrin of the Institut Laue-Langevin in Grenoble was used to determine the yields of the very asymmetric light fission products (A=84-69) as a function of A, Z, and the kinetic energy E. The proton pairing effect causes fine structures in the mass distribution, in the mean nuclear charge anti Z and its variance σ z , and in the mean kinetic energies of the elements. The neutron pairing effect in the production yields is found for the first time of the same order of magnitude than the proton pairing effect. In the mass region investigated both are the largest observed in fission of 235 U. A decrease in the mean kinetic energy for the isotopes of Ni and Cu was observed. It points to a large deformation at scission. Our results support the view that very asymmetric low-energy fission is a weakly dissipative process. The highly deformed transient system breaks by a slow necking-in process [fr

  8. Physics with a very long neutrino factory baseline

    International Nuclear Information System (INIS)

    Gandhi, Raj; Winter, Walter

    2007-01-01

    We discuss the neutrino oscillation physics of a very long neutrino factory baseline over a broad range of lengths (between 6000 km and 9000 km), centered on the 'magic baseline' (∼7500 km) where correlations with the leptonic CP phase are suppressed by matter effects. Since the magic baseline depends only on the density, we study the impact of matter density profile effects and density uncertainties over this range, and the impact of detector locations off the optimal baseline. We find that the optimal constant density describing the physics over this entire baseline range is about 5% higher than the average matter density. This implies that the magic baseline is significantly shorter than previously inferred. However, while a single detector optimization requires fine-tuning of the (very long) baseline length, its combination with a near detector at a shorter baseline is much less sensitive to the far detector location and to uncertainties in the matter density. In addition, we point out different applications of this baseline which go beyond its excellent correlation and degeneracy resolution potential. We demonstrate that such a long baseline assists in the improvement of the θ 13 precision and in the resolution of the octant degeneracy. Moreover, we show that the neutrino data from such a baseline could be used to extract the matter density along the profile up to 0.24% at 1σ for large sin 2 2θ 13 , providing a useful discriminator between different geophysical models

  9. Collective properties and shapes of nuclei at very high spins

    International Nuclear Information System (INIS)

    Johnson, N.R.

    1991-01-01

    A topic which has been of major interest to us for some years now involves the evolution of nuclear collectivity at high rotational frequencies and the accompanying changes in the shapes of nuclei in these extreme conditions. We carry out these studies by determining the dynamic electromagnetic multipole moments which are a reflection of the collective aspects of the nuclear wave functions. The most direct way to get these multipole moments is by measurements of excited-state lifetimes which provide the transition matrix elements in a fairly straightforward fashion. Although the primary emphasis of this paper is on the collectivity of the high-spin states in 160 Yb and 164 Yb, it is important to review briefly some work we began about ten years ago lifetime studies of moderately high spins in nuclei near N=90 using the recoil-distance (RD) method. These nuclei are just at the onset of permanent deformation and are known to be very soft with respect to deformation changes. This softness is clearly illustrated in contour diagrams of their potential-energy surfaces. For example, the potential energy surface of 160 Yb reveals that the minimum in the potential occurs around var-epsilon ∼ 0.2 and that it is very shallow in the γ degree of freedom. Because of their γ softness, we have studied several nuclei near N=90 to assess to what extent the polarization effects induced by rotation alignment of high-j quasiparticles affect their collectivity

  10. Image segmentation evaluation for very-large datasets

    Science.gov (United States)

    Reeves, Anthony P.; Liu, Shuang; Xie, Yiting

    2016-03-01

    With the advent of modern machine learning methods and fully automated image analysis there is a need for very large image datasets having documented segmentations for both computer algorithm training and evaluation. Current approaches of visual inspection and manual markings do not scale well to big data. We present a new approach that depends on fully automated algorithm outcomes for segmentation documentation, requires no manual marking, and provides quantitative evaluation for computer algorithms. The documentation of new image segmentations and new algorithm outcomes are achieved by visual inspection. The burden of visual inspection on large datasets is minimized by (a) customized visualizations for rapid review and (b) reducing the number of cases to be reviewed through analysis of quantitative segmentation evaluation. This method has been applied to a dataset of 7,440 whole-lung CT images for 6 different segmentation algorithms designed to fully automatically facilitate the measurement of a number of very important quantitative image biomarkers. The results indicate that we could achieve 93% to 99% successful segmentation for these algorithms on this relatively large image database. The presented evaluation method may be scaled to much larger image databases.

  11. Very Deep Convolutional Neural Networks for Morphologic Classification of Erythrocytes.

    Science.gov (United States)

    Durant, Thomas J S; Olson, Eben M; Schulz, Wade L; Torres, Richard

    2017-12-01

    Morphologic profiling of the erythrocyte population is a widely used and clinically valuable diagnostic modality, but one that relies on a slow manual process associated with significant labor cost and limited reproducibility. Automated profiling of erythrocytes from digital images by capable machine learning approaches would augment the throughput and value of morphologic analysis. To this end, we sought to evaluate the performance of leading implementation strategies for convolutional neural networks (CNNs) when applied to classification of erythrocytes based on morphology. Erythrocytes were manually classified into 1 of 10 classes using a custom-developed Web application. Using recent literature to guide architectural considerations for neural network design, we implemented a "very deep" CNN, consisting of >150 layers, with dense shortcut connections. The final database comprised 3737 labeled cells. Ensemble model predictions on unseen data demonstrated a harmonic mean of recall and precision metrics of 92.70% and 89.39%, respectively. Of the 748 cells in the test set, 23 misclassification errors were made, with a correct classification frequency of 90.60%, represented as a harmonic mean across the 10 morphologic classes. These findings indicate that erythrocyte morphology profiles could be measured with a high degree of accuracy with "very deep" CNNs. Further, these data support future efforts to expand classes and optimize practical performance in a clinical environment as a prelude to full implementation as a clinical tool. © 2017 American Association for Clinical Chemistry.

  12. Strongly Interacting Matter at Very High Energy Density

    International Nuclear Information System (INIS)

    McLerran, L.

    2011-01-01

    The authors discuss the study of matter at very high energy density. In particular: what are the scientific questions; what are the opportunities to makes significant progress in the study of such matter and what facilities are now or might be available in the future to answer the scientific questions? The theoretical and experimental study of new forms of high energy density matter is still very much a 'wild west' field. There is much freedom for developing new concepts which can have order one effects on the way we think about such matter. It is also a largely 'lawless' field, in that concepts and methods are being developed as new information is generated. There is also great possibility for new experimental discovery. Most of the exciting results from RHIC experiments were unanticipated. The methods used for studying various effects like flow, jet quenching, the ridge, two particle correlations etc. were developed as experiments evolved. I believe this will continue to be the case at LHC and as we use existing and proposed accelerators to turn theoretical conjecture into tangible reality. At some point this will no doubt evolve into a precision science, and that will make the field more respectable, but for my taste, the 'wild west' times are the most fun.

  13. Radio variability survey of very low luminosity protostars

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Minho; Kang, Miju [Korea Astronomy and Space Science Institute, 776 Daedeokdaero, Daejeon 305-348 (Korea, Republic of); Lee, Jeong-Eun, E-mail: minho@kasi.re.kr [Department of Astronomy and Space Science, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of)

    2014-07-01

    Ten very low luminosity objects were observed multiple times in the 8.5 GHz continuum in search of protostellar magnetic activities. A radio outburst of IRAM 04191+1522 IRS was detected, and the variability timescale was about 20 days or shorter. The results of this survey and archival observations suggest that IRAM 04191+1522 IRS is in active states about half the time. Archival data show that L1014 IRS and L1148 IRS were detectable previously and suggest that at least 20%-30% of very low luminosity protostars are radio variables. Considering the variability timescale and flux level of IRAM 04191+1522 IRS and the previous detection of the circular polarization of L1014 IRS, the radio outbursts of these protostars are probably caused by magnetic flares. However, IRAM 04191+1522 IRS is too young and small to develop an internal convective dynamo. If the detected radio emission is indeed coming from magnetic flares, the discovery implies that the flares may be caused by the fossil magnetic fields of interstellar origin.

  14. Very-long-term storage of fission products

    International Nuclear Information System (INIS)

    Sousselier, Y.; Pradel, J.; Cousin, O.

    The large majority of the fission products, with 99.9 percent of the radioactivity content, do not pose actual problems in storage in a geological formation for which we can guarantee total confinement. Safety of storage in a geological formation for the radionuclides of long half-life is based in particular on the absorption capacity of the geological formations and the example of the Oklo fossil reactor and the retention of Pu which is produced is a striking example. But the problems are not the same, and the properties that we look for in the terrain are not the same. We could thus be led to storage in different geological formations for the fission products and the long-half-life emitters. Their separation is interesting from this point of view, but the date at which the separation is made will not be necessarily that of reprocessing. But there is a question of one or the other, and these storages will offer a very high level of insurance and will present only the potential hazards that are very comparable with those presented by natural conditions

  15. Deficits in vision and visual attention associated with motor performance of very preterm/very low birth weight children.

    Science.gov (United States)

    Geldof, Christiaan J A; van Hus, Janeline W P; Jeukens-Visser, Martine; Nollet, Frans; Kok, Joke H; Oosterlaan, Jaap; van Wassenaer-Leemhuis, Aleid G

    2016-01-01

    To extend understanding of impaired motor functioning of very preterm (VP)/very low birth weight (VLBW) children by investigating its relationship with visual attention, visual and visual-motor functioning. Motor functioning (Movement Assessment Battery for Children, MABC-2; Manual Dexterity, Aiming & Catching, and Balance component), as well as visual attention (attention network and visual search tests), vision (oculomotor, visual sensory and perceptive functioning), visual-motor integration (Beery Visual Motor Integration), and neurological status (Touwen examination) were comprehensively assessed in a sample of 106 5.5-year-old VP/VLBW children. Stepwise linear regression analyses were conducted to investigate multivariate associations between deficits in visual attention, oculomotor, visual sensory, perceptive and visual-motor integration functioning, abnormal neurological status, neonatal risk factors, and MABC-2 scores. Abnormal MABC-2 Total or component scores occurred in 23-36% of VP/VLBW children. Visual and visual-motor functioning accounted for 9-11% of variance in MABC-2 Total, Manual Dexterity and Balance scores. Visual perceptive deficits only were associated with Aiming & Catching. Abnormal neurological status accounted for an additional 19-30% of variance in MABC-2 Total, Manual Dexterity and Balance scores, and 5% of variance in Aiming & Catching, and neonatal risk factors for 3-6% of variance in MABC-2 Total, Manual Dexterity and Balance scores. Motor functioning is weakly associated with visual and visual-motor integration deficits and moderately associated with abnormal neurological status, indicating that motor performance reflects long term vulnerability following very preterm birth, and that visual deficits are of minor importance in understanding motor functioning of VP/VLBW children. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Study and realization of pixelated APD Geiger photodetectors of very high sensitivity for Very High Energy gamma astronomy

    International Nuclear Information System (INIS)

    Jradi, K.

    2010-07-01

    Very High Energy gamma ray astronomy uses till now exclusively as detector the Photomultiplier Tube (PMT) to collect weak light flux of atmospheric showers. But an alternative is now emerging: Avalanche Photodiodes polarized in Geiger mode called 'Geiger-APD'. The PMT is a detector designed in the 70's which presents many advantages but also suffers from several drawbacks: size, weight, cost, sensitivity to magnetic field but especially difficulty to realize its pixelation in matrix. Geiger-APDs are semi-conductor devices made of PN junction integrated in a special technology to detect very low light flux, thanks to the polarization beyond the avalanche voltage. Geiger-APD presents very high photoelectron gain (∼106) strongly dependant on the polarization voltage beyond avalanche. These photodiodes present many advantages with respect to PMT, mainly as concerns miniaturization for applications based on imaging, such as the detection of Cerenkov flashes in gamma ray astronomy. In this thesis, we present the study, the design and the realization of a technological structure, based on Silicon. This structure has shown reliability to detect weak luminous flux with breakdown voltage at 12 V and dark current below 10 pA at breakdown. We also developed several models, physical and electrical, necessary to the technological optimization, as well to the development of control and readout circuits, i.e. the basis of any imaging technology. The work presented here consists in the study, the design and the realization of a matrix of high sensitivity pixels. A project of a Cerenkov telescope based on this innovative technology is also presented. (author)

  17. Distance and Kinematics of the Red Hypergiant VY CMa: Very Long Baseline Array and Very Large Array Astrometry

    Science.gov (United States)

    Zhang, B.; Reid, M. J.; Menten, K. M.; Zheng, X. W.

    2012-01-01

    We report astrometric results of phase-referencing very long baseline interferometry observations of 43 GHz SiO maser emission toward the red hypergiant VY Canis Majoris (VY CMa) using the Very Long Baseline Array (VLBA). We measured a trigonometric parallax of 0.83 ± 0.08 mas, corresponding to a distance of 1.20+0.13 -0.10 kpc. Compared to previous studies, the spatial distribution of SiO masers has changed dramatically, while its total extent remains similar. The internal motions of the maser spots are up to 1.4 mas yr-1, corresponding to 8 km s-1, and show a tendency for expansion. After modeling the expansion of maser spots, we derived an absolute proper motion for the central star of μ x = -2.8 ± 0.2 and μ y = 2.6 ± 0.2 mas yr-1 eastward and northward, respectively. Based on the maser distribution from the VLBA observations, and the relative position between the radio photosphere and the SiO maser emission at 43 GHz from the complementary Very Large Array observations, we estimate the absolute position of VY CMa at mean epoch 2006.53 to be αJ2000 = 07h22m58.s3259 ± 0.s0007, δJ2000 = -25°46'03farcs063 ± 0farcs010. The position and proper motion of VY CMa from the VLBA observations differ significantly with values measured by the Hipparcos satellite. These discrepancies are most likely associated with inhomogeneities and dust scattering the optical light in the circumstellar envelope. The absolute proper motion measured with VLBA suggests that VY CMa may be drifting out of the giant molecular cloud to the east of it.

  18. DISTANCE AND KINEMATICS OF THE RED HYPERGIANT VY CMa: VERY LONG BASELINE ARRAY AND VERY LARGE ARRAY ASTROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B. [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Reid, M. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Menten, K. M. [Max-Plank-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Zheng, X. W., E-mail: bzhang@mpifr.de [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2012-01-01

    We report astrometric results of phase-referencing very long baseline interferometry observations of 43 GHz SiO maser emission toward the red hypergiant VY Canis Majoris (VY CMa) using the Very Long Baseline Array (VLBA). We measured a trigonometric parallax of 0.83 {+-} 0.08 mas, corresponding to a distance of 1.20{sup +0.13}{sub -0.10} kpc. Compared to previous studies, the spatial distribution of SiO masers has changed dramatically, while its total extent remains similar. The internal motions of the maser spots are up to 1.4 mas yr{sup -1}, corresponding to 8 km s{sup -1}, and show a tendency for expansion. After modeling the expansion of maser spots, we derived an absolute proper motion for the central star of {mu}{sub x} = -2.8 {+-} 0.2 and {mu}{sub y} = 2.6 {+-} 0.2 mas yr{sup -1} eastward and northward, respectively. Based on the maser distribution from the VLBA observations, and the relative position between the radio photosphere and the SiO maser emission at 43 GHz from the complementary Very Large Array observations, we estimate the absolute position of VY CMa at mean epoch 2006.53 to be {alpha}{sub J2000} = 07{sup h}22{sup m}58.{sup s}3259 {+-} 0.{sup s}0007, {delta}{sub J2000} = -25 Degree-Sign 46'03.''063 {+-} 0.''010. The position and proper motion of VY CMa from the VLBA observations differ significantly with values measured by the Hipparcos satellite. These discrepancies are most likely associated with inhomogeneities and dust scattering the optical light in the circumstellar envelope. The absolute proper motion measured with VLBA suggests that VY CMa may be drifting out of the giant molecular cloud to the east of it.

  19. DISTANCE AND KINEMATICS OF THE RED HYPERGIANT VY CMa: VERY LONG BASELINE ARRAY AND VERY LARGE ARRAY ASTROMETRY

    International Nuclear Information System (INIS)

    Zhang, B.; Reid, M. J.; Menten, K. M.; Zheng, X. W.

    2012-01-01

    We report astrometric results of phase-referencing very long baseline interferometry observations of 43 GHz SiO maser emission toward the red hypergiant VY Canis Majoris (VY CMa) using the Very Long Baseline Array (VLBA). We measured a trigonometric parallax of 0.83 ± 0.08 mas, corresponding to a distance of 1.20 +0.13 –0.10 kpc. Compared to previous studies, the spatial distribution of SiO masers has changed dramatically, while its total extent remains similar. The internal motions of the maser spots are up to 1.4 mas yr –1 , corresponding to 8 km s –1 , and show a tendency for expansion. After modeling the expansion of maser spots, we derived an absolute proper motion for the central star of μ x = –2.8 ± 0.2 and μ y = 2.6 ± 0.2 mas yr –1 eastward and northward, respectively. Based on the maser distribution from the VLBA observations, and the relative position between the radio photosphere and the SiO maser emission at 43 GHz from the complementary Very Large Array observations, we estimate the absolute position of VY CMa at mean epoch 2006.53 to be α J2000 = 07 h 22 m 58. s 3259 ± 0. s 0007, δ J2000 = –25°46'03.''063 ± 0.''010. The position and proper motion of VY CMa from the VLBA observations differ significantly with values measured by the Hipparcos satellite. These discrepancies are most likely associated with inhomogeneities and dust scattering the optical light in the circumstellar envelope. The absolute proper motion measured with VLBA suggests that VY CMa may be drifting out of the giant molecular cloud to the east of it.

  20. Imaging of tissue sections with very slow electrons

    Energy Technology Data Exchange (ETDEWEB)

    Frank, L., E-mail: ludek@isibrno.cz [Institute of Scientific Instruments AS CR, v.v.i., Královopolská 147, 61264 Brno (Czech Republic); Nebesářová, J.; Vancová, M. [Biology Centre AS CR, v.v.i., Branišovská 31, 37005 České Budějovice (Czech Republic); Paták, A.; Müllerová, I. [Institute of Scientific Instruments AS CR, v.v.i., Královopolská 147, 61264 Brno (Czech Republic)

    2015-01-15

    The examination of thin sections of tissues with electron microscopes is an indispensable tool. Being composed of light elements, samples of living matter illuminated with electrons at the usual high energies of tens or even hundreds of kiloelectronvolts provide very low image contrasts in transmission or scanning transmission electron microscopes. Therefore, heavy metal salts are added to the specimen during preparation procedures (post-fixation with osmium tetroxide or staining). However, these procedures can modify or obscure the ultrastructural details of cells. Here we show that the energy of electrons used for the scanned transmission imaging of tissue sections can be reduced to mere hundreds or even tens of electronvolts and can produce extremely high contrast even for samples free of any metal salts. We found that when biasing a sufficiently thin tissue section sample to a high negative potential in a scanning transmission electron microscope, thereby reducing the energy of the electrons landing on the sample, and collecting the transmitted electrons with a grounded detector, we obtain a high contrast revealing structure details not enhanced by heavy atoms. Moreover, bombardment with slow electrons sensitively depolymerises the resin in which the tissue is embedded, thereby enhancing the transmitted signal with no observable loss of structure details. The use of low-energy electrons requires ultrathin sections of a thickness of less than 10 nm, but their preparation is now possible. Ultralow energy STEM provides a tool enabling the observation of very thin biological samples without any staining. This method should also be advantageous for examination of 2D crystals, thin films of polymers, polymer blends, etc. - Highlights: • Sections of a thickness below 10 nm were imaged in STEM at hundreds and tens of eV. • Image contrast grows steeply with decreasing electron energy in the STEM. • Very slow electrons provide high contrast for samples free of

  1. Very High Output Thermoelectric Devices Based on ITO Nanocomposites

    Science.gov (United States)

    Fralick, Gustave; Gregory, Otto J.

    2009-01-01

    A material having useful thermoelectric properties was synthesized by combining indium-tin-oxide (ITO) with a NiCoCrAlY alloy/alumina cermet. This material had a very large Seebeck coefficient with electromotive-force-versustemperature behavior that is considered to be excellent with respect to utility in thermocouples and other thermoelectric devices. When deposited in thin-film form, ceramic thermocouples offer advantages over precious-metal (based, variously, on platinum or rhodium) thermocouples that are typically used in gas turbines. Ceramic thermocouples exhibit high melting temperatures, chemical stability at high temperatures, and little or no electromigration. Oxide ceramics also resist oxidation better than metal thermocouples, cost substantially less than precious-metal thermocouples, and, unlike precious-metal thermocouples, do not exert catalytic effects.

  2. Bremsstrahlung and pair production in crystals at very high energies

    International Nuclear Information System (INIS)

    Nikishov, A.I.

    1981-01-01

    The probabilities for bremsstrahlung and pair production in crystals are discussed under stringent condition when the trajectory of the high-energy electron crosses very many atoms of a crystal row (or plane). It is shown that for sufficiently long path in such conditions the probabilities are described by the formulas for these processes in a strong constant magnetic field exerting on electron the same deflection as the atom row. It turns out that for lead at energy approximately 10 12 eV the radiation length is shortened many hundred times. For greater energies the decrease of probabilities per unit length with increase of energy goes as W varies as Esup(-1/3)

  3. Assessment of very high-temperature reactors in process applications

    International Nuclear Information System (INIS)

    Spiewak, I.; Jones, J.E. Jr.; Gambill, W.R.; Fox, E.C.

    1976-11-01

    An overview is presented of the technical and economic feasibility for the development of a very high-temperature reactor (VHTR) and associated processes. A critical evaluation of VHTR technology for process temperatures of 1400 and 2000 0 F is made. Additionally, an assessment of potential market impact is made to determine the commercial viability of the reactor system. It is concluded that VHTR process heat in the range of 1400 to 1500 0 F is attainable with near-term technology. However, process heat in excess of 1600 0 F would require considerably more materials development. The potential for the VHTR could include a major contribution to synthetic fuel, hydrogen, steel, and fertilizer production and to systems for transport and storage of high-temperature heat. A recommended development program including projected costs is presented

  4. Rational Suicide, Euthanasia, and the Very Old: Two Case Reports

    Directory of Open Access Journals (Sweden)

    Anne Pamela Frances Wand

    2016-01-01

    Full Text Available Suicide amongst the very old is an important public health issue. Little is known about why older people may express a wish to die or request euthanasia and how such thoughts may intersect with suicide attempts. Palliative care models promote best care as holistic and relieving suffering without hastening death in severely ill patients; but what of those old people who are tired of living and may have chronic symptoms, disability, and reduced quality of life? Two cases of older people who attempted suicide but expressed a preference for euthanasia were it legal are presented in order to illustrate the complexity underlying such requests. The absence of a mood or anxiety disorder underpinning their wishes to die further emphasises the importance of understanding the individual’s narrative and the role of a formulation in guiding broad biopsychosocial approaches to management.

  5. Multidimensional Simulations of Colliding Outbursts from very Massive Stars

    Science.gov (United States)

    Chen, Ke-Jung; Woosley, Stan

    2015-08-01

    Massive stars that end their lives with helium cores in the range of 35 to 65 solar masses are known to produce repeated thermonuclear outbursts due to a recurring pair-instability. In some of these events, solar masses of material are ejected in repeated outbursts of several times 1050 erg each. Such models can be used to explain the strong mass loss rates at the last moment before the massive stars die. Collisions between these shells can sometimes produce very luminous transients. Previous 1D studies of these events produce thin,high-density shells as one ejection plows into another. We present the first multidimensional simulations of these collisions, we show that the development of a Rayleigh-Taylor instability truncates the growth of the high density spike and drives mixing between the shells.

  6. CERN in FP7: very successful participation so far

    CERN Multimedia

    2009-01-01

    The first two years of the seventh Framework Programme were very successful for CERN – 27 EU projects were selected for funding in 2007 and 2008, with the total EC contribution exceeding 33 million euros.The seventh European Union Framework Programme for research, technological development and demonstration activities (FP7) started on 1 January 2007 and will cover the period from 2007 to 2013. With a total budget of 50.5 billion euros, FP7 is the largest Framework Programme in the history of the EU. FP7 consists of four major sub-programmes, referred to as "Specific Programmes": "Cooperation" is focused on collaborative research projects and is divided into 10 thematic areas. "Ideas" is a new EU programme for funding frontier research in all fields of science. "Capacities" aims at strengthening the research capacities in Europe, including research infrastructures and e-infrastructures. Finally, "People" succeeds the p...

  7. Precision Viticulture from Multitemporal, Multispectral Very High Resolution Satellite Data

    Science.gov (United States)

    Kandylakis, Z.; Karantzalos, K.

    2016-06-01

    In order to exploit efficiently very high resolution satellite multispectral data for precision agriculture applications, validated methodologies should be established which link the observed reflectance spectra with certain crop/plant/fruit biophysical and biochemical quality parameters. To this end, based on concurrent satellite and field campaigns during the veraison period, satellite and in-situ data were collected, along with several grape samples, at specific locations during the harvesting period. These data were collected for a period of three years in two viticultural areas in Northern Greece. After the required data pre-processing, canopy reflectance observations, through the combination of several vegetation indices were correlated with the quantitative results from the grape/must analysis of grape sampling. Results appear quite promising, indicating that certain key quality parameters (like brix levels, total phenolic content, brix to total acidity, anthocyanin levels) which describe the oenological potential, phenolic composition and chromatic characteristics can be efficiently estimated from the satellite data.

  8. The Category Cued Recall test in very mild Alzheimer's disease

    DEFF Research Database (Denmark)

    Vogel, Asmus; Mortensen, E.L.; Gade, A.

    2007-01-01

    Episodic memory tests that measure cued recall may be particularly effective in the diagnosis of early Alzheimer's disease (AD) because they examine both episodic and semantic memory functions. The Category Cued Recall (CCR) test provides superordinate semantic cues at encoding and retrieval...... was taken as the standard. It was also investigated whether the two episodic memory tests correlated with measures of semantic memory. The tests were administered to 35 patients with very mild AD (Mini Mental State Examination score > 22) and 28 control subjects. Both tests had high sensitivity (>88......%) with high specificity (>89%). One out of the five semantic memory tests was significantly correlated to performances on CCR, whereas delayed recall on the ADAS-cog memory test was significantly correlated to two semantic tests. In conclusion, the discriminative validity of the CCR test and the ADAS...

  9. Are inflationary predictions sensitive to very high energy physics?

    International Nuclear Information System (INIS)

    Burgess, C.P.; Lemieux, F.; Holman, R.; Cline, J.M.

    2003-01-01

    It has been proposed that the successful inflationary description of density perturbations on cosmological scales is sensitive to the details of physics at extremely high (trans-Planckian) energies. We test this proposal by examining how inflationary predictions depend on higher-energy scales within a simple model where the higher-energy physics is well understood. We find the best of all possible worlds: inflationary predictions are robust against the vast majority of high-energy effects, but can be sensitive to some effects in certain circumstances, in a way which does not violate ordinary notions of decoupling. This implies both that the comparison of inflationary predictions with CMB data is meaningful, and that it is also worth searching for small deviations from the standard results in the hopes of learning about very high energies. (author)

  10. Very high energy gamma ray astronomy from Hanle

    International Nuclear Information System (INIS)

    Chitnis, Varsha R.

    2015-01-01

    Over a past decade very high energy (VHE) gamma ray astronomy has emerged as a major astronomical discipline. In India, we have a long tradition of experiments in this field. Few years ago, multi-institutional Himalayan Gamma Ray Observatory (HiGRO) collaboration was formed to set up VHE gamma rays experiments at Hanle, a high altitude location in Himalayas. HAGAR, the first phase of this collaboration is operational since 2008. HAGAR has successfully detected VHE gamma ray emission from some of the extragalactic objects like Mrk 421, Mrk 501 as well as galactic sources including Crab nebula/pulsar. Details of HAGAR telescope system and results obtained will be discussed. HiGRO is now gearing up for the next phase, i.e. 21 m diameter MACE telescope, which is being installed at Hanle at present. Details of MACE telescope system and future plans will be discussed. (author)

  11. Turbulent kinetic energy spectrum in very anisothermal flows

    International Nuclear Information System (INIS)

    Serra, Sylvain; Toutant, Adrien; Bataille, Françoise; Zhou, Ye

    2012-01-01

    In this Letter, we find that the Kolmogorov scaling law is no longer valid when the flow is submitted to strong dilatational effects caused by high temperature gradients. As a result, in addition to the nonlinear time scale, there is a much shorter “temperature gradients” time scale. We propose a model that estimates the time scale of the triple decorrelation incorporating the influences of the temperature gradient. The model agrees with the results from the thermal large-eddy simulations of different Reynolds numbers and temperature gradients. This Letter provides a better understanding of the very anisothermal turbulent flow. -- Highlights: ► Turbulent flows subject to high temperature gradients are considered. ► The new “temperature gradients” time scale is determined. ► A generalized energy spectrum is developed to incorporate the effects of temperature gradient.

  12. A very simple technique to repair Grynfeltt-Lesshaft hernia.

    Science.gov (United States)

    Solaini, Leonardo; di Francesco, F; Gourgiotis, S; Solaini, Luciano

    2010-08-01

    A very simple technique to repair a superior lumbar hernia is described. The location of this type of hernia, also known as the Grynfeltt-Lesshaft hernia, is defined by a triangle placed in the lumbar region. An unusual case of a 67-year-old woman with a superior lumbar hernia is reported. The diagnosis was made by physical examination. The defect of the posterior abdominal wall was repaired with a polypropylene dart mesh. The patient had no evidence of recurrence at 11 months follow up. The surgical approach described in this paper is simple and easy to perform, and its result is comparable with other techniques that are much more sophisticated. No cases on the use of dart mesh to repair Grynfeltt-Lesshaft hernia have been reported by surgical journals indexed in PubMed.

  13. Very high temperature measurements: Applications to nuclear reactor safety tests

    International Nuclear Information System (INIS)

    Parga, Clemente-Jose

    2013-01-01

    This PhD dissertation focuses on the improvement of very high temperature thermometry (1100 deg. C to 2480 deg. C), with special emphasis on the application to the field of nuclear reactor safety and severe accident research. Two main projects were undertaken to achieve this objective: - The development, testing and transposition of high-temperature fixed point (HTFP) metal-carbon eutectic cells, from metrology laboratory precision (±0.001 deg. C) to applied research with a reasonable degradation of uncertainties (±3-5 deg. C). - The corrosion study and metallurgical characterization of Type-C thermocouple (service temp. 2300 deg. C) prospective sheath material was undertaken to extend the survivability of TCs used for molten metallic/oxide corium thermometry (below 2000 deg. C)

  14. Hard, infrared black coating with very low outgassing

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenko, P J; Behne, D M; Casserly, T; Boardman, W; Upadhyaya, D; Boinapally, K; Gupta, M; Cao, Y

    2008-06-02

    Infrared astronomical instruments require absorptive coatings on internal surfaces to trap scattered and stray photons. This is typically accomplished with any one of a number of black paints. Although inexpensive and simple to apply, paint has several disadvantages. Painted surfaces can be fragile, prone to shedding particles, and difficult to clean. Most importantly, the vacuum performance is poor. Recently a plasma enhanced chemical vapor deposition (PECVD) process was developed to apply thick (30 {micro}m) diamond-like carbon (DLC) based protective coatings to the interior of oil pipelines. These DLC coatings show much promise as an infrared black for an ultra high vacuum environment. The coatings are very robust with excellent cryogenic adhesion. Their total infrared reflectivity of < 10% at normal incidence approaches that of black paints. We measured outgas rates of <10{sup -12} Torr liter/sec cm{sup 2}, comparable to bare stainless steel.

  15. Dysphonia in very preterm children: a review of the evidence.

    Science.gov (United States)

    Reynolds, Victoria; Meldrum, Suzanne; Simmer, Karen; Vijayasekaran, Shyan; French, Noel

    2014-01-01

    Intubation is a known risk factor for dysphonia yet is essential in the perinatal care of many very preterm infants. Children born preterm, who are frequently resuscitated with endotracheal intubation, may be at risk of dysphonia at school age and beyond. To identify and describe the evidence pertaining to long-term voice outcomes and risk factors for developing dysphonia in preterm children. In addition to case studies and series, three larger-scale studies have reported on dysphonia and voice outcomes in preterm children. Studies reporting treatment outcomes were not available. Factors associated with poor voice outcomes included female gender, birth weight Dysphonia is a newly reported, long-term complication of preterm birth, yet the number of relevant studies remains limited. Further research is required to confirm the risk factors for developing dysphonia, which will inform future voice treatment studies.

  16. Very low intensity storage-ring profile monitor

    International Nuclear Information System (INIS)

    Hardek, T.; Kells, W.; Lai, H.

    1981-01-01

    The Fermilab Colliding Beams Group has now accomplished several cooling experiments (electron and stochastic methods) on proton beams in the ''electron cooling'' synchrotron ring built for this purpose. A key to analyzing the performance of any test cooling system is a complete set of beam diagnostics to measure the beam emittances in all three planes. For longitudinal emittance the authors use Schottky scans (although very low intensities make this difficult, necessitating a departure from the conventional method by bunching the beams). A description is given of the MCP telescope and readout which evolved independently as a complete monitor system using residual gas in lieu of Mg vapor. To date all transverse measurements of coasting beam profiles have been obtained in this mode. 2 refs

  17. Percolation Effects in Very-High-Energy Cosmic Rays

    International Nuclear Information System (INIS)

    Dias de Deus, J.; Santo, M.C. Espirito; Pimenta, M.; Pajares, C.

    2006-01-01

    Cosmic ray data at high energies present a number of well-known puzzles. At very high energies (E∼10 20 eV) there are indications of a discrepancy between ground array experiments and fluorescence detectors. On the other hand, the dependence of the depth of the shower maximum X max with the primary energy shows a change in slope (E∼10 17 eV) which is usually explained assuming a composition change. Both effects could be accounted for in models predicting that above a certain energy showers would develop deeper in the atmosphere. In this Letter we argue that this can be done naturally by including percolation effects in the description of the shower development, which cause a change in the behavior of the inelasticity K above E≅10 17 eV

  18. Higgs boson production by very high energy neutrinos

    International Nuclear Information System (INIS)

    Mikaelian, K.O.; Oakes, R.J.

    1978-11-01

    Higgs bosons may be produced by bremsstrahlung off a virtual W/sup +-/ or a Z 0 exchanged in a charged or neutral current neutrino interaction. The production cross sections are calculated, and it is pointed out that they cannot grow quadratically with E/sub nu/ as had been suggested earlier, and it is argued that at best they can increase like the square of ln s/M 2 /sub W,Z/ at very high energies. Using a simple approximation for the propagator effect, numerical results in the high energy regime 1 TeV less than or equal to E/sub nu/ less than or equal to 1000 TeV appropriate for DUMAND. 9 references

  19. Very high Mach number shocks - Theory. [in space plasmas

    Science.gov (United States)

    Quest, Kevin B.

    1986-01-01

    The theory and simulation of collisionless perpendicular supercritical shock structure is reviewed, with major emphasis on recent research results. The primary tool of investigation is the hybrid simulation method, in which the Newtonian orbits of a large number of ion macroparticles are followed numerically, and in which the electrons are treated as a charge neutralizing fluid. The principal results include the following: (1) electron resistivity is not required to explain the observed quasi-stationarity of the earth's bow shock, (2) the structure of the perpendicular shock at very high Mach numbers depends sensitively on the upstream value of beta (the ratio of the thermal to magnetic pressure) and electron resistivity, (3) two-dimensional turbulence will become increasingly important as the Mach number is increased, and (4) nonadiabatic bulk electron heating will result when a thermal electron cannot complete a gyrorbit while transiting the shock.

  20. Very Low Level Radioactive Solid Waste Management in CHINA

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ting Jun [No. 117 Xisanhuanbeilu, Haidian District, Beijing (China)

    2011-06-15

    This paper introduces the policy and regulations on very low level waste (VLLW) management in China. Given the important decommissioning and site restoration program of the old facility, it is considered necessary to create a new disposal facility dedicated to VLLW. Many general design principles are in common with to the disposal facility for low and intermediate level waste (LILW), namely the isolation of the waste by means of a multibarrier system, but using bentonite and/or high density polyethylene membranes instead of the generalized use of concrete barriers. The design of the facility is consistent with the design of disposal facilities for hazardous waste. The engineering design of two VLLW disposal facilities is introduced.

  1. Lightweight computational steering of very large scale molecular dynamics simulations

    International Nuclear Information System (INIS)

    Beazley, D.M.

    1996-01-01

    We present a computational steering approach for controlling, analyzing, and visualizing very large scale molecular dynamics simulations involving tens to hundreds of millions of atoms. Our approach relies on extensible scripting languages and an easy to use tool for building extensions and modules. The system is extremely easy to modify, works with existing C code, is memory efficient, and can be used from inexpensive workstations and networks. We demonstrate how we have used this system to manipulate data from production MD simulations involving as many as 104 million atoms running on the CM-5 and Cray T3D. We also show how this approach can be used to build systems that integrate common scripting languages (including Tcl/Tk, Perl, and Python), simulation code, user extensions, and commercial data analysis packages

  2. Very High Frequency Switch-Mode Power Supplies

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre

    The importance of technology and electronics in our daily life is constantly increasing. At the same time portability and energy efficiency are currently some of the hottest topics. This creates a huge need for power converters in a compact form factor and with high efficiency, which can supply...... these electronic devices. This calls for new technologies in order to miniaturize the power electronics of today. One way to do this is by increasing the switching frequency dramatically and develop very high frequency switch mode power supplies. If these converters can be designed to operate efficiently, a huge...... size, weight and cost reduction can be achieved due to the smaller energy storing elements needed at these frequencies. The research presented in this thesis focuses on exactly this. First various technologies for miniaturization of power supplies are studied, e.g. piezo electric transformers, wide...

  3. Very High Frequency Galvanic Isolated Offline Power Supply

    DEFF Research Database (Denmark)

    Pedersen, Jeppe Arnsdorf

    During the last decades many researchers have turned their attention to raising the operation frequency of power converters to the very high frequency (VHF) range going from 30 MHz to 300 MHz. Increasing the operating frequency of a power converter leads to smaller energy storing components...... inverters with a single combined rectifier. The converter designed to deliver 9 W to a 60 V LED load and is achieving an efficiency of 89.4% and a power density of 2.14 W3 . The development of this converter proof that offline VHF converter can be implemented with high efficiencies even for low power applications...... are described together with the possibility of using capacitors as the power galvanic isolation, both methods of creating galvanic isolation are implemented in converters. Regarding EMC a series of converters with different filter implementations are examined. The results from the conducted mea-surement from 150...

  4. Relativistic rise measurements with very fine sampling intervals

    International Nuclear Information System (INIS)

    Ludlam, T.; Platner, E.D.; Polychronakos, V.A.; Lindenbaum, S.J.; Kramer, M.A.; Teramoto, Y.

    1980-01-01

    The motivation of this work was to determine whether the technique of charged particle identification via the relativistic rise in the ionization loss can be significantly improved by virtue of very small sampling intervals. A fast-sampling ADC and a longitudinal drift geometry were used to provide a large number of samples from a single drift chamber gap, achieving sampling intervals roughly 10 times smaller than any previous study. A single layer drift chamber was used, and tracks of 1 meter length were simulated by combining together samples from many identified particles in this detector. These data were used to study the resolving power for particle identification as a function of sample size, averaging technique, and the number of discrimination levels (ADC bits) used for pulse height measurements

  5. Nonlinear generalization of special relativity at very high energies

    International Nuclear Information System (INIS)

    Winterberg, F.

    1984-01-01

    It is shown, that the introduction of a fundamental length constant into the operator representation of the quantum mechanical commutation relations, as suggested by Bagge, leads to a nonlinear generalization of the Lorentz transformations. The theory requires the introduction of a substratum (ether) and which can be identified as the zero point vacuum energy. At very high energies a non-Lorentz invariant behaviour for the cross sections between elementary particles is predicted. Using the Einstein clock synchronisation definition, the velocity of light is also constant and equal to c in the new theory, but the zero point vacuum energy becomes finite, as are all other quantities which are divergent in Lorentz invariant quantum field theories. In the limiting case where the length constant is set equal to zero, the zero point vacuum energy diverges and special relativity is recovered. (orig.) [de

  6. Dirac equation in very special relativity for hydrogen atom

    Energy Technology Data Exchange (ETDEWEB)

    Maluf, R.V., E-mail: r.v.maluf@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760 Fortaleza, Ceará (Brazil); Silva, J.E.G., E-mail: euclides@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760 Fortaleza, Ceará (Brazil); Cruz, W.T., E-mail: wilamicruz@gmail.com [Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Juazeiro do Norte, 63040-000 Juazeiro do Norte, Ceará (Brazil); Almeida, C.A.S., E-mail: carlos@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760 Fortaleza, Ceará (Brazil)

    2014-11-10

    In this work, we study the modified Dirac equation in the framework of very special relativity (VSR). The low-energy regime is accessed and the nonrelativistic Hamiltonian is obtained. It turns out that this Hamiltonian is similar to that achieved from the Standard Model Extension (SME) via coupling of the spinor field to a Lorentz-violating term, but new features arise inherited from the non-local character of the VSR. In addition, the implications of the VSR-modified Lorentz symmetry on the spectrum of a hydrogen atom are determined by calculating the first-order energy corrections in the context of standard quantum mechanics. Among the results, we highlight that the modified Hamiltonian provides non-vanishing corrections which lift the degeneracy of the energy levels and allow us to find an upper bound upon the VSR-parameter.

  7. Very bright, near-infrared single photon emitters in diamond

    Directory of Open Access Journals (Sweden)

    D. W. M. Lau

    2013-09-01

    Full Text Available We demonstrate activation of bright diamond single photon emitters in the near infrared range by thermal annealing alone, i.e., without ion implantation. The activation is crucially dependent on the annealing ambient. The activation of the single photon emitters is only observed when the sample is annealed in forming gas (4% H2 in Ar above temperatures of 1000 °C. By contrast, no emitters are activated by annealing in vacuum, oxygen, argon or deuterium. The emitters activated by annealing in forming gas exhibit very bright emission in the 730-760 nm wavelength range and have linewidths of ∼1.5-2.5 nm at room temperature.

  8. Properties of light nuclei very far from beta stability

    International Nuclear Information System (INIS)

    Detraz, C.

    1989-01-01

    This paper will be devoted to underlying the major developments which occurred in the study of light nuclei far from the valley of stability since the last International Nuclear Physics Conference in Harrogate (1986) where that field of research was already presented (1). A broader review will appear elsewhere (2). Therefore only some highlights are presented and discussed here. Probably the main development of the field in recent years has to do with a change in its aims and methods. The goal is no longer to search for individual hitherto unobserved nuclear species and to report their existence. It has become to study the major nuclear properties such as binding energy, half life, size, decay modes over broad ranges of neighbouring isotopes extending very far from stability in order to put to a test the current nuclear models based essentially on observations of nuclei near the stability line

  9. Mutation induction in yeast by very heavy ions

    Science.gov (United States)

    Kiefer, J.

    1994-10-01

    Resistance to canavanine was studied in haploid yeast after exposure to heavy ions (argon to uranium) of energies between 1 and 10 MeV/u covering a LET-range up to about 10000 keV/μm. Mutations were found in all instances but the induction cross sections increased with ion energy. This is taken to mean that the contribution of penumbra electrons plays an important role. The probability to recover surviving mutants is highest if the cell is not directly hit by the particle. The experiments demonstrate that the geometrical dimensions of the target cell nucleus as well as its sensitivity in terms of survival have a critical influence on mutation induction with very heavy ions.

  10. A 43-level filterless CMLI with very low harmonics values

    Directory of Open Access Journals (Sweden)

    Mahmoud El-Bakry

    2014-12-01

    Full Text Available This paper introduces a 43-level asymmetric uniform step cascaded multilevel inverter (CMLI that consists of four H-bridges per phase, with different dc sources of values E, 2E, 7E and 11E. A mixed integer linear programming (MILP optimization model is applied to determine the switching angles of the CMLI power switches that can minimize the values of any undesired harmonics. Single phase and three phase cases are considered. The results show very low values of all the undesired harmonics over wide voltage ranges, which agree with the IEEE standards 519-1992 for voltage distortion limits for both the values of %THDE and %VHmax so that no output filters are needed.

  11. Clustering of very luminous infrared galaxies and their environment

    Science.gov (United States)

    Gao, YU

    1993-01-01

    The IRAS survey reveals a class of ultraluminous infrared (IR) galaxies (ULIRG's) with IR luminosities comparable to the bolometric luminosities of quasars. The nature, origin, and evolution of ULIRG's are attracting more and more attention recently. Since galaxy morphology is certainly a function of environment, morphological observations show that ULIRG's are interacting/merging galaxies, and some ULIRG's might be the dust-enshrouded quasars (S88) or giant ellipticals, the study of ULIRG's environment and large scale clustering effects should be worthwhile. ULIRG's and very luminous IR galaxies have been selected from the 2Jy IRAS redshift survey. Meanwhile, a catalog of IRAS groups of galaxies has been constructed using a percolation-like algorithm. Therefore, whether ULIRG's and/or VLIRG's have a group environment can be checked immediately. Other aspects of the survey are discussed.

  12. Very low bit rate voice for packetized mobile applications

    International Nuclear Information System (INIS)

    Knittle, C.D.; Malone, K.T.

    1991-01-01

    This paper reports that transmitting digital voice via packetized mobile communications systems that employ relatively short packet lengths and narrow bandwidths often necessitates very low bit rate coding of the voice data. Sandia National Laboratories is currently developing an efficient voice coding system operating at 800 bits per second (bps). The coding scheme is a modified version of the 2400 bps NSA LPC-10e standard. The most significant modification to the LPC-10e scheme is the vector quantization of the line spectrum frequencies associated with the synthesis filters. An outline of a hardware implementation for the 800 bps coder is presented. The speech quality of the coder is generally good, although speaker recognition is not possible. Further research is being conducted to reduce the memory requirements and complexity of the vector quantizer, and to increase the quality of the reconstructed speech. This work may be of use dealing with nuclear materials

  13. Mass Measurement of Very Short Half-Lived Nuclei

    CERN Document Server

    Duma, M; Iacob, V E; Thibault, C

    2002-01-01

    The MISTRAL (Mass measurements at ISolde with a Transmission RAdiofrequency spectrometer on-Line) experiment exploits a rapid measurement technique to make accurate mass determinations of very short-lived nuclei. The physics goals are to elucidate new nuclear structure effects and constrain nuclear mass models in regions of interest to nuclear astrophysics.\\\\ \\\\The spectrometer, installed in May 97, performed as promised in the proposal with mass resolution exceeding 100,000. In its first experiment in July 1998, neutron-rich Na isotopes having half-lives as short as 31 ms were measured. A second experiment in November 1998 enabled us to improve the measurement precision of the isotopes $^{26-30}$Na to about 20 keV. The measurement program continues as experiment IS 373.

  14. Plastic film materials for dosimetry of very large absorbed doses

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, Arne; Abdel-Rahim, F.

    1985-01-01

    Most plastic films have limited response ranges for dosimetry because of radiation-induced brittleness, degradation, or saturation of the signal used for analysis (e.g. spectrophotometry) at high doses. There are, however, a few types of thin plastic films showing linearity of response even up...... to doses as high as 2 × 106 Gy (200 Mrad) without severe loss of mechanical properties. Among many candidate film types tested, those showing such resistance to radiation damage and continued response at such high doses are polyethylene terephthalate, high-density polyethylene, dyed polyvinylchloride......, the dyed polychlorostyrenes show essentially the same response to radiation-processing gamma-ray fields and to very high-intensity electron beams, and a relatively stable absorption spectrum at wavelengths for dosimetry analysis in the visible spectral region of ≈430 nm....

  15. New experiments on few-electron very heavy atoms

    International Nuclear Information System (INIS)

    Gould, H.

    1985-07-01

    New experiments, to test quantum electrodynamics (QED) in strong Coulomb fields and to study atomic collisions at ultrarelativistic energies, are proposed. A 0.1% measurement of the 2 2 P/sub 1/2/-2 2 S/sub 1/2/ splitting in lithium like uranium (Z=92) and the 2 3 P 0 - 2 3 S 1 splitting in heliumlike uranium is proposed as a sub 1% test of the Lamb shift in a strong Coulomb field. Measurements of the hyperfine splitting of hydrogenlike thallium (Z=81) and the g/sub j/ factor of the ground state of hydrogenlike uranium are propsed as a test of the QED contribution to the magnetic moment of an electron bound in a strong Coulomb field. Measurements of capture cross sections for ultra relativistic very heavy nuclei are proposed to look for the capture of electrons from pair production. 40 refs., 7 figs., 2 tabs

  16. Physical properties of drawn very low density polyethylene films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B.S. [Yeungnam University, Kyongsan (Korea, Republic of); Lee, J.Y. [Korea Institute of Footwear and Leather Technology, Pusan (Korea, Republic of)

    1998-05-01

    Very low density polyethylene (VLDPE) films were prepared by quenching the pressed melt in ice water. The films were drawn with universal testing machine under constant temperature at four different temperatures, 30, 60, 80, and 110 {sup o} C. Thermal, mechanical properties, grossity, and gas permeability of the drawn VLDPE films as a function of draw ratio were investigated to examine their applicability to packaging. The films showed tow melting peaks, i.e., low temperature endotherm (LTE) and high temperature endotherm (HTE). The melting temperatures were increased with the draw ratio and the drawing temperature. The mechanical properties of the VLDPE film drawn at 80 {sup o} C were superior to those drawn at 110 {sup o} C. The grossity and gas permeability of the VLDPE film drawn at 110 {sup o} C were found to be best among the drawn films.

  17. Visualising very large phylogenetic trees in three dimensional hyperbolic space

    Directory of Open Access Journals (Sweden)

    Liberles David A

    2004-04-01

    Full Text Available Abstract Background Common existing phylogenetic tree visualisation tools are not able to display readable trees with more than a few thousand nodes. These existing methodologies are based in two dimensional space. Results We introduce the idea of visualising phylogenetic trees in three dimensional hyperbolic space with the Walrus graph visualisation tool and have developed a conversion tool that enables the conversion of standard phylogenetic tree formats to Walrus' format. With Walrus, it becomes possible to visualise and navigate phylogenetic trees with more than 100,000 nodes. Conclusion Walrus enables desktop visualisation of very large phylogenetic trees in 3 dimensional hyperbolic space. This application is potentially useful for visualisation of the tree of life and for functional genomics derivatives, like The Adaptive Evolution Database (TAED.

  18. Very low pressure high power impulse triggered magnetron sputtering

    Science.gov (United States)

    Anders, Andre; Andersson, Joakim

    2013-10-29

    A method and apparatus are described for very low pressure high powered magnetron sputtering of a coating onto a substrate. By the method of this invention, both substrate and coating target material are placed into an evacuable chamber, and the chamber pumped to vacuum. Thereafter a series of high impulse voltage pulses are applied to the target. Nearly simultaneously with each pulse, in one embodiment, a small cathodic arc source of the same material as the target is pulsed, triggering a plasma plume proximate to the surface of the target to thereby initiate the magnetron sputtering process. In another embodiment the plasma plume is generated using a pulsed laser aimed to strike an ablation target material positioned near the magnetron target surface.

  19. Dark matter structures and emission of very long gravitational waves

    International Nuclear Information System (INIS)

    Bisnovatyi-Kogan, G.S.

    2005-01-01

    Formation of large structure in the Universe as a result of gravitational instability in cold dark matter is investigated in a simple analytical model. Collapse of the rotating spheroid is approximated by a system of ordinary differential equations describing its dynamics. The gravitational potential is approximated by the one of the uniform Maclaurin spheroid. Development of gravitational instability and collapse in the dark matter medium do not lead to any shock formation or radiation, but is characterized by non-collisional relaxation, which is accompanied by the mass and angular momentum losses. Phenomenological account of these processes is done in this model. Formation of the equilibrium configuration dynamics of collapse is investigated. A very long gravitational wave emission during the collapse is estimated, and their possible connection with the observed gravitational lenses is discussed

  20. Orthology detection combining clustering and synteny for very large datasets.

    Science.gov (United States)

    Lechner, Marcus; Hernandez-Rosales, Maribel; Doerr, Daniel; Wieseke, Nicolas; Thévenin, Annelyse; Stoye, Jens; Hartmann, Roland K; Prohaska, Sonja J; Stadler, Peter F

    2014-01-01

    The elucidation of orthology relationships is an important step both in gene function prediction as well as towards understanding patterns of sequence evolution. Orthology assignments are usually derived directly from sequence similarities for large data because more exact approaches exhibit too high computational costs. Here we present PoFF, an extension for the standalone tool Proteinortho, which enhances orthology detection by combining clustering, sequence similarity, and synteny. In the course of this work, FFAdj-MCS, a heuristic that assesses pairwise gene order using adjacencies (a similarity measure related to the breakpoint distance) was adapted to support multiple linear chromosomes and extended to detect duplicated regions. PoFF largely reduces the number of false positives and enables more fine-grained predictions than purely similarity-based approaches. The extension maintains the low memory requirements and the efficient concurrency options of its basis Proteinortho, making the software applicable to very large datasets.

  1. Orthology detection combining clustering and synteny for very large datasets.

    Directory of Open Access Journals (Sweden)

    Marcus Lechner

    Full Text Available The elucidation of orthology relationships is an important step both in gene function prediction as well as towards understanding patterns of sequence evolution. Orthology assignments are usually derived directly from sequence similarities for large data because more exact approaches exhibit too high computational costs. Here we present PoFF, an extension for the standalone tool Proteinortho, which enhances orthology detection by combining clustering, sequence similarity, and synteny. In the course of this work, FFAdj-MCS, a heuristic that assesses pairwise gene order using adjacencies (a similarity measure related to the breakpoint distance was adapted to support multiple linear chromosomes and extended to detect duplicated regions. PoFF largely reduces the number of false positives and enables more fine-grained predictions than purely similarity-based approaches. The extension maintains the low memory requirements and the efficient concurrency options of its basis Proteinortho, making the software applicable to very large datasets.

  2. Guidelines for Feeding Very Low Birth Weight Infants

    Directory of Open Access Journals (Sweden)

    Sourabh Dutta

    2015-01-01

    Full Text Available Despite the fact that feeding a very low birth weight (VLBW neonate is a fundamental and inevitable part of its management, this is a field which is beset with controversies. Optimal nutrition improves growth and neurological outcomes, and reduces the incidence of sepsis and possibly even retinopathy of prematurity. There is a great deal of heterogeneity of practice among neonatologists and pediatricians regarding feeding VLBW infants. A working group on feeding guidelines for VLBW infants was constituted in McMaster University, Canada. The group listed a number of important questions that had to be answered with respect to feeding VLBW infants, systematically reviewed the literature, critically appraised the level of evidence, and generated a comprehensive set of guidelines. These guidelines form the basis of this state-of-art review. The review touches upon trophic feeding, nutritional feeding, fortification, feeding in special circumstances, assessment of feed tolerance, and management of gastric residuals, gastro-esophageal reflux, and glycerin enemas.

  3. Physics Potential of Very Intense Conventional Neutrino Beams

    CERN Document Server

    Gómez-Cadenas, J J; Burguet-Castell, J; Casper, David William; DOnega, M; Gilardoni, S S; Hernández, Pilar; Mezzetto, Mauro

    2001-01-01

    The physics potential of high intensity conventional beams is explored. We consider a low energy super beam which could be produced by a proposed new accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowledge of the atmospheric parameters and measure or severely constrain the parameter connecting the atmospheric and solar realms. It is also shown that a very large water detector could eventually observe leptonic CP violation. The reach of such an experiment to the neutrino mixing parameters would lie in-between the next generation of neutrino experiments (MINOS, OPERA, etc) and a future neutrino factory.

  4. The very large research infrastructures: the French road-map

    International Nuclear Information System (INIS)

    2008-01-01

    After having recalled that the notion of TGIR (Tres Grande Infrastructure de Recherche, Very large research infrastructure) has evolved in time and now encompasses many different realities in terms of domain or size, this document briefly presents the main challenging fields of research: the planet, the universe seen from the Earth, particles and nuclei, matter, information, communication, computing and data services, human and social sciences, life sciences and health. It indicates TGIRs which have been selected for the French road-map: some already exist and operational (46), some are not yet operational but have been decided in terms of financing (19) and some are still projected but with different levels of priority. Appendices give selection criteria, working group compositions for different domains, and description sheets for these TGIRs (nature, localisation, scientific tools, spin-offs and impacts, international value, concerned scientific community, budget)

  5. TESTFIELD TRENTO: GEOMETRIC EVALUATION OF VERY HIGH RESOLUTION SATELLITE IMAGERY

    Directory of Open Access Journals (Sweden)

    G. Agugiaro

    2012-07-01

    Full Text Available Today the use of spaceborne Very High Spatial Resolution (VHSR optical sensors for automatic 3D information extraction is increasing in the scientific and civil communities. The 3D Optical Metrology (3DOM Unit of the Bruno Kessler Foundation (FBK in Trento (Italy has collected stereo VHSR satellite imagery, as well as aerial and terrestrial data over Trento, with the aim to create a complete data collection with state-of-the-art datasets for investigations on image analysis, automatic digital surface model (DSM generation, 2D/3D feature extraction, city modelling and data fusion. The testfield region covers the city of Trento, characterised by very dense urban (historical centre, residential and industrial areas, and the surrounding hills and steep mountains (approximate height range 200-2100 m with cultivations, forests and bare soil. This paper reports the analysis conducted in FBK on the VHSR spaceborne imagery of Trento testfield for 3D information extraction. The data include two stereo-pairs acquired by WorldView-2 in August 2010 and by GeoEye-1 in September 2011 in panchromatic and multispectral mode, together with their original Rational Polynomial Coefficients (RPC, and the position and description of well distributed ground points. For reference and validation, a DSM from airborne LiDAR acquisition is used. The paper gives details on the project and the dataset characteristics. The results achieved by 3DOM on DSM extraction from WorldView-2 and GeoEye-1 stereo-pairs are shown and commented.

  6. Giat Industries selected for construction of the "Very Large Telescope"

    Science.gov (United States)

    1995-06-01

    Versailles-Satory (France) May 31, 1995 - Giat Industries has just obtained a contract from the European Southern Observatory (ESO) for the construction of the primary and tertiary mirror supports and the positioning apparatus of the world's largest optical telescope. This contract, worth almost 140 million francs, represents over 100,000 hours of work. It was won by Gitech, a division of Giat Industries, in collaboration with the Sfim group, following an international competition between the largest European groups in the space field. Gitech is charged with the development of civil and military industrial equipment for the Giat Industries group, in particular in high technology fields. The VLT (Very Large Telescope) will be installed in Chile before the year 2000; the delivery schedule provides for reception of the first assembly in May 1997. It will consist of four telescopes of 8.2m diameter, providing, in its most powerful configuration, a close-up view of an object measuring one meter on the surface of the moon. The cell, built by Gitech, is one of the key parts of the telescope. It mainly consists of a very rigid metal structure and an electro-hydraulic system of more that 200 hydraulic jacks and 150 electrically-controlled jacks linking the metallic structure to the mirror. This structure, produced to an original design of laser-welded steel chambers, weighs less than 10 tonnes and will support over 37 tonnes of mirror and equipment, while guaranteeing precise positioning to within a micron. The electro-hydraulic jack system, manufactured in collaboration with the Sfim group, will support and position the mirror, and correct its geometry by applying a precise distribution of forces to its rear. The assembly is designed to meet the requirements of para-seismic safety. Gitech is also producing the computerised control system to ensure the operation and the reliability of the assembly.

  7. Landslide detection using very high-resolution satellite imageries

    Science.gov (United States)

    Suga, Yuzo; Konishi, Tomohisa

    2012-10-01

    The heavy rain induced by the 12th typhoon caused landslide disaster at Kii Peninsula in the middle part of Japan. We propose a quick response method for landslide disaster mapping using very high resolution (VHR) satellite imageries. Especially, Synthetic Aperture Radar (SAR) is effective because it has the capability of all weather and day/night observation. In this study, multi-temporal COSMO-SkyMed imageries were used to detect the landslide areas. It was difficult to detect the landslide areas using only backscatter change pattern derived from pre- and post-disaster COSMOSkyMed imageries. Thus, the authors adopted a correlation analysis which the moving window was selected for the correlation coefficient calculation. Low value of the correlation coefficient reflects land cover change between pre- and post-disaster imageries. This analysis is effective for the detection of landslides using SAR data. The detected landslide areas were compared with the area detected by EROS-B high resolution optical image. In addition, we have developed 3D viewing system for geospatial visualizing of the damaged area using these satellite image data with digital elevation model. The 3D viewing system has the performance of geographic measurement with respect to elevation height, area and volume calculation, and cross section drawing including landscape viewing and image layer construction using a mobile personal computer with interactive operation. As the result, it was verified that a quick response for the detection of landslide disaster at the initial stage could be effectively performed using optical and SAR very high resolution satellite data by means of 3D viewing system.

  8. Process metallurgical evaluation and application of very fine bubbling technology

    Energy Technology Data Exchange (ETDEWEB)

    Catana, C.; Gotsis, V.S.; Dourdounis, E.; Angelopoulos, G.N.; Papamantellos, D.C. [Lab. of Metallurgy, Univ. of Patras, Rio (Greece); Mavrommatis, K. [IEHK, RWTH Aachen, Aachen (Germany)

    2002-12-01

    The potential of VFB (Very Fine Bubbling)-technology in steelmaking, developed for the production of super clean steels, was investigated. Recent R and D work has proven that with very fine argon bubbling through a developed Special Porous Plug (SPP) at low flow rates, the total oxygen content of low carbon steel grades can be lowered to a level of 6 ppm under industrial vacuum conditions and to a level of 10 ppm under argon protective atmosphere. The perspective of industrial application of the VFB technology to a 56-t ladle furnace of Helliniki Halyvourgia S.A., Greece, in order to improve steel cleanliness, requires additional R and D efforts. It is important to define the limits of VFB technology in respect of alloys dissolution, mixing time and homogenisation of steel and slag/metal reactions. In this work, a gas driven bubble aqueous reactor model simulating the bottom gas stirred ladle by means of gas injection through a SPP and a conventional porous plug was studied. Various operating conditions as well as different positions for the porous plug with and without a top oil layer were simulated. Tests concerning mixing time, solid-liquid mass transfer and critical gas flow rate, liquid/liquid mass transfer, using the SPP and a conventional porous plug have been performed. The evaluation of experimental results delivered important information for the design and operation of steel ladles, applying VFB-technology. Experimental results with SPP bubbles' agitated steel (1600 C) in laboratory and technical scale experiments in IF and VIF are presented and discussed. (orig.)

  9. Very long-chain acyl-coenzyme A dehydrogenase deficiency

    Directory of Open Access Journals (Sweden)

    A. V. Degtyareva

    2014-01-01

    Full Text Available The paper describes a case of a baby with a severe infant form of very long-chain acyl-coenzyme A dehydrogenase deficiency, a very rare genetic disorder. The basis for the disease is a disorder of mitochondrial β-oxidation of long-chain fatty acids. Accumulation of acyl-CoA-derived fatty acids causes a toxic effect on the myocardium and cardiac conduction system, liver, skeletal muscles, and other organs. The development of hypoglycemia is typical. Treatment in the acute period involves the immediately ceased delivery of long-chain triglycerides, the provision of the body with medium-chain triglycerides, and the correction of glycemia. In our observation the baby was born at term with a satisfactory condition in a family with a poor history (the first baby had suddenly died at the age of 3,5 months. The disease manifested itself as bradyarrhythmia and cardiac arrest on day 2 of life. The clinical symptom complex also included hepatomegalia, hypoglycemic episodes, lactate acidosis, and elevated blood levels of cytolytic enzymes and creatine phosphokinase. The diagnosis was suspected on the basis of the high blood values of acylcarnitines (primarily C14:1 and verified by a molecular genetic examination. Syndrome therapy and dietotherapy resulted in the abolishment of the abnormality. At the age of 2 years of life, the infant’s physical, motor, mental, and speech development corresponded to his age although he had mild right-sided hemiparesis. Thus, timely therapy determines the favorable prognosis of the disease even in its severe infant forms. 

  10. INFLAMMATORY BOWEL DISEASE WITH A VERY EARLY ONSET

    Directory of Open Access Journals (Sweden)

    E. A. Kornienko

    2016-01-01

    Full Text Available Inflammatory bowel disease (Crohn's disease and ulcerative colitis has a tendency to manifest at earlier age. In childhood (< 6 years of age it has an especially severe course and is characterized by high grade inflammation, predominantly in the colon, by complication and extra-intestinal autoimmune injury. At younger age, Crohn's disease and ulcerative colitis require more aggressive treatment with frequently poor results. From genetic point of view, monogenic mutations controlling the immune response are characteristic for these diseases with an early onset; therefore, they are frequently associated with primary immunodeficiency. This implies various immunologic deficits, such as breakdown of the epithelial barrier, phagocytic dysfunction and dysfunction of Т and В lymphocytes and regulatory Т cells. Depending on this, a number of primary immunodeficiencies are identified associated with monogenic mutations of more than 50 genes. There some age-related specific features at manifestation. Thus, defects in interleukin 10 and FOXP3 manifest in the first months of life, whereas severe combined immunodeficiencies and phagocytosis defects become evident somewhat later. Virtually all 24 children with very early onset of inflammatory bowel disease, whom we examined, had immunologic defects and one child had a XIAP gene mutation. After identification of a specific immunologic defect, one can understand the mechanism of the disease and suspect one or another genetic defect with subsequent reasonable assessment of mutations in candidate genes. Detection of immunologic and genetic defects in children with a very early onset of inflammatory bowel disease allows for choosing an adequate strategy of non-conventional treatment that may differ depending on the mechanism of the disease.

  11. Orbit Determination with Very Short Arcs: Admissible Regions

    Science.gov (United States)

    Gronchi, G. F.; Milani, A.; de'Michieli Vitturi, M.; Knezevic, Z.

    2004-05-01

    Contemporary observational surveys provide a huge number of detections of small solar system bodies, in particular of asteroids. These have to be reduced in real time in order to optimize the observational strategy and to select the targets for the follow-up and for the subsequent determination of an orbit. Typically, reported astrometry consists of few positions over a short time span, and this information is often not enough to compute a preliminary orbit and perform an identification. Classical methods for preliminary orbit determination based on three observations fail in such cases, and a new approach is necessary to cope with the problem. We introduce the concept of attributable, which is a vector composed by two angles and two angular velocities at a given time. It is then shown that the missing values (geocentric range and range rate), necessary for the computation of an orbit, can be constrained to a compact set that we call admissible region (AR). The latter is defined on the basis of requirements that the body belongs to the solar system, that it is not a satellite of the Earth, and that it is not a "shooting star" (very close and very small). A mathematical description of the AR is given, together with the proof of its topological properties: it turns out that the AR cannot have more than two connected components. A sampling of the AR can be performed by means of a Delaunay triangulation. A finite number of six-parameter sets of initial conditions are thus defined, with each node of triangulation representing a Virtual Asteroid for which it is possible to propagate the corresponding orbit and to predict ephemerides.

  12. Radiotherapy of metastatic spinal cord compression in very elderly patients

    International Nuclear Information System (INIS)

    Rades, Dirk; Hoskin, Peter J.; Karstens, Johann H.; Rudat, Volker; Veninga, Theo; Stalpers, Lukas J.A.; Schild, Steven E.; Dunst, Juergen

    2007-01-01

    Purpose: Owing to the aging of the population, the proportion of elderly patients receiving cancer treatment has increased. This study investigated the results of radiotherapy (RT) for metastatic spinal cord compression (MSCC) in the very elderly, because few data are available for these patients. Methods and Materials: The data from 308 patients aged ≥75 years who received short-course (treatment time 1-5 days) or long-course RT (2-4 weeks) for MSCC were retrospectively analyzed for functional outcome, local control, and survival. Furthermore, nine potential prognostic factors were investigated: gender, performance status, interval from tumor diagnosis to MSCC, tumor type, number of involved vertebrae, other bone or visceral metastases, ambulatory status, and speed at which motor deficits developed. Results: Improvement of motor deficits occurred in 25% of patients, with no further progression of MSCC in an additional 59%. The 1-year local control and survival rate was 92% and 43%, respectively. Improved functional outcomes were associated with ambulatory status and slower developing motor deficits. Improved local control resulted from long-course RT. Improved survival was associated with a longer interval from tumor diagnosis to MSCC, tumor type (breast/prostate cancer, myeloma/lymphoma), lack of visceral or other bone metastases, ambulatory status, and a slower development of motor deficits. Conclusion: Short- and long-course RT are similarly effective in patients aged ≥75 years regarding functional outcome and survival. Long-course RT provided better local control. Patients with better expected survival should receive long-course RT and others short-course RT. The criteria for selection of an appropriate regimen for MSCC in very elderly patients should be the same as for younger individuals

  13. Natural very-low-frequency sferics and headache

    Science.gov (United States)

    Vaitl, D.; Propson, N.; Stark, R.; Schienle, A.

      Very-low-frequency (VLF) atmospherics or sferics are pulse-shaped alternating electric and magnetic fields which originate from atmospheric discharges (lightning). The objective of the study was threefold: (i) to analyse numerous parameters characterizing the sferics activity with regard to their suitability for field studies, (ii) to identify meteorological processes related to the sferics activity and (iii) to investigate the possible association of sferics with pain processes in patients suffering from migraine- and tension-type headaches. Over a period of 6 months (July through December) the sferics activity in the area of Giessen (Germany) was recorded. Three sferics parameters were chosen. The number of sferics impulses per day, the variability of the impulse rate during a day and the variability in comparison to the preceding day were correlated with weather processes (thunderstorm, temperature, vapour pressure, barometric pressure, humidity, wind velocity, warm sector). Significant correlations were obtained during the summer months (July, August) but not during the autumn months (October, November, December). During autumn, however, the sferics activity was correlated with the occurrence of migraine-type headaches (r=0.33, Pheadache diary over a period of 6 months (July-December). While the thunderstorm activity was very intense during July and August, no relationship between sferics and migraine was found. In summer, tension-type headaches were associated with meteorological parameters such as temperature (r=0.42, P<0.01) and vapour pressure (r=0.28, P<0.05). Although the sferics activity can explain a small percentage of the variation in migraine occurrence, a direct influence was more likely exerted by visible or otherwise perceptible weather conditions (thunderstorms, humidity, vapour pressure, warm sector, etc.) than by the sferics activity itself.

  14. The effects and consequences of very large explosive volcanic eruptions.

    Science.gov (United States)

    Self, S

    2006-08-15

    Every now and again Earth experiences tremendous explosive volcanic eruptions, considerably bigger than the largest witnessed in historic times. Those yielding more than 450km3 of magma have been called super-eruptions. The record of such eruptions is incomplete; the most recent known example occurred 26000 years ago. It is more likely that the Earth will next experience a super-eruption than an impact from a large meteorite greater than 1km in diameter. Depending on where the volcano is located, the effects will be felt globally or at least by a whole hemisphere. Large areas will be devastated by pyroclastic flow deposits, and the more widely dispersed ash falls will be laid down over continent-sized areas. The most widespread effects will be derived from volcanic gases, sulphur gases being particularly important. This gas is converted into sulphuric acid aerosols in the stratosphere and layers of aerosol can cover the global atmosphere within a few weeks to months. These remain for several years and affect atmospheric circulation causing surface temperature to fall in many regions. Effects include temporary reductions in light levels and severe and unseasonable weather (including cool summers and colder-than-normal winters). Some aspects of the understanding and prediction of super-eruptions are problematic because they are well outside modern experience. Our global society is now very different to that affected by past, modest-sized volcanic activity and is highly vulnerable to catastrophic damage of infrastructure by natural disasters. Major disruption of services that society depends upon can be expected for periods of months to, perhaps, years after the next very large explosive eruption and the cost to global financial markets will be high and sustained.

  15. Visual search and attention in five-year-old very preterm/very low birth weight children.

    Science.gov (United States)

    Geldof, Christiaan J A; de Kieviet, Jorrit F; Dik, Marjolein; Kok, Joke H; van Wassenaer-Leemhuis, Aleid G; Oosterlaan, Jaap

    2013-12-01

    This study aimed to establish visual search performance and attention functioning in very preterm/very low birth weight (VP/VLBW) children using novel and well established measures, and to study their contribution to intellectual functioning. Visual search and attention network efficiency were assessed in 108 VP/VLBW children and 72 age matched term controls at 5.5 years corrected age. Visual search performance was investigated with a newly developed paradigm manipulating stimulus density and stimulus organization. Attention functioning was studied using the Attention Network Test (ANT). Intellectual functioning was measured by a short form of the Wechsler Preschool and Primary Scale of Intelligence. Data were analyzed using ANOVAs and multiple regression analyses. Visual search was less efficient in VP/VLBW children as compared to term controls, as indicated by increased search time (0.31 SD, p = .04) and increased error rate (0.36 SD, p = .02). In addition, VP/VLBW children demonstrated poorer executive attention as indicated by lower accuracy for the executive attention measure of the ANT (0.61 SD, p attention measures (0.13 SD, p = .42). Visual search time and error rate, and executive attention, collectively, accounted for 14% explained variance in full scale IQ (R(2) = .14, p attention. Visual attention dysfunctions contributed to intelligence, suggesting the opportunity to improve intellectual functioning by using interventions programs that may enhance attention capacities. © 2013.

  16. NEONATAL MORBIDITY AND EARLY OUTCOME OF VERY PRETERM INFANTS

    Directory of Open Access Journals (Sweden)

    Heljić Suada

    2013-01-01

    Full Text Available Background: Although the mortality rate for preterm infants and the gestational age-specific mortality rate have dramatically improved over the last 3 to 4 decades, infants born preterm remain vulnerable to many complications, including respiratory distress syndrome, chronic lung disease, necrotizing enterocolitis, a compromised immune system, cardiovascular disorders, hearing and vision problems, and brain lesions.The aim is to determine mortality and morbidity rates and selected outcome variables for preterm infant’s < 30 weeks’ gestation, who were admitted to the NICU. Patients and methods: This study enrolled 102 infants with gestational age less than 30 weeks’ gestation, hospitalized in Neonatal Intensive Care Unit, Pediatric Hospital, Clinical University Center Sarajevo, from Jan. 2010 to Dec. 2010. Parameters taken at admission were: birth weight, gestational age, Apgar score, excess base and CRIB score. Early outcome is considered as a survival at discharge or common preterm morbidities presented during hospitalizationResults: The mean BW of evaluated preterm infants was 1086 ± 250 g, the mean GA27.89 ± 1.97, Apgar score 5.41 ± 1.76, excess base at admission 6.39 ± 1.74 and mean CRIB score 3.72 ± 3.16. The overall survival rate was 70.5%. Selected outcomes at discharge were: RDS with 70.5% infants treated with natural surfactant, PDA treated with NSAIDS (23.5%, brain injury ( ≥ grade 3 IVH or PVL 16.6%, NEC Bell stages II or III 9.8%, BPD 25/72 (33.3% of infants who survived to 36 weeks postmenstrual age. In 38 (37.2% infants, episodes of infections were noticed (one or more episodes in 25 infants, half of them were caused by Gram positive bacteria, most frequent coagulasa negative staphylococci. Klebsiella pneumoniae was the mostfrequent organism among Gram negative bacteria. One patient had invasive candidiasis caused by Candida albicans. In 5 infants (4.9% early onset of sepsis was documented. Conclusion: Very preterm

  17. The aggregation efficiency of very fine volcanic ash

    Science.gov (United States)

    Del Bello, E.; Taddeucci, J.; Scarlato, P.

    2013-12-01

    Explosive volcanic eruptions can discharge large amounts of very small sized pyroclasts (under 0.090 mm) into the atmosphere that may cause problems to people, infrastructures and environment. The transport and deposition of fine ash are ruled by aggregation that causes premature settling of fine ash and, as consequence, significantly reduces the concentration of airborne material over long distances. Parameterizing the aggregation potential of fine ash is then needed to provide accurate modelling of ash transport and deposition from volcanic plumes. Here we present the first results of laboratory experiments investigating the aggregation efficiency of very fine volcanic particles. Previous laboratory experiments have shown that collision kinetic and relative humidity provide the strongest effect on aggregation behaviour but were only limited to particles with size > 0.125 mm. In our work, we focus on natural volcanic ash at ambient humidity with particles size aggregation potential. Two types of ash were used in our experiments: fresh ash, collected during fall-out from a recent plume-forming eruption at Sakurajima (Japan -July 2013) and old ash, collected from fall-out tephra deposits at Campi Flegrei (Italy, ca. 10 ka), to account for the different chemical composition and morphoscopic effects of altered ash on aggregation efficiency. Total samples were hand sieved to obtain three classes with unimodal grain size distributions (sieved from the top of a transparent tank where a fan, placed at the bottom, allows turbulent dispersion of particles. Collision and sticking of particles on a vertical glass slide were filmed with a high speed cameras at 6000 fps. Our lenses arrangement provide high image resolution allowing to capture particles down to 0.005 mm in diameter. Video sequences of particles motion and collision were then processed with image analysis and particle tracking tools to determine i) the particle number density and ii) the grain size distribution

  18. Binning sequences using very sparse labels within a metagenome

    Directory of Open Access Journals (Sweden)

    Halgamuge Saman K

    2008-04-01

    the methods tested. Most importantly, the proposed method does not require knowledge from known genomes and uses only very few labels (one per species is sufficient in most cases, which are extracted from the metagenome itself. These advantages make it a very attractive binning method. S-GSOM outperformed the binning methods that depend on already-sequenced genomes, and compares well to the current most advanced binning method, PhyloPythia.

  19. The Southwest Configuration for the Next Generation Very Large Array

    Science.gov (United States)

    Irwin Kellermann, Kenneth; Carilli, Chris; Condon, James; Cotton, William; Murphy, Eric Joseph; Nyland, Kristina

    2018-01-01

    We discuss the planned array configuration for the Next Generation Very Large Array (ngVLA). The configuration, termed the "Southwest Array," consists of 214 antennas each 18 m in diameter, distributed over the Southwest United States and Northern Mexico. The antenna locations have been set applying rough real-world constraints, such as road, fiber, and power access. The antenna locations will be fixed, with roughly 50% of the antennas in a "core" of 2 km diameter, located at the site of the JVLA. Another 30% of the antennas will be distributed over the Plains of San Augustin to a diameter of 30 km, possibly along, or near, the current JVLA arms. The remaining 20% of the antennas will be distributed in a rough two-arm spiral pattern to the South and East, out to a maximum distance of 500 km, into Texas, Arizona, and Chihuahua. Years of experience with the VLA up to 50 GHz, plus intensive antenna testing up to 250 GHz for the ALMA prototype antennas, verify the VLA site as having very good observing conditions (opacity, phase stability), up to 115 GHz (ngVLA Memo No. 1). Using a suite of tools implemented in CASA, we have made extensive imaging simulations with this configuration. We find that good imaging performance can be obtained through appropriate weighting of the visibilities, for resolutions ranging from that of the core of the array (1" at 30 GHz), out to the longest baselines (10 mas at 30 GHz), with a loss of roughly a factor of two in sensitivity relative to natural weighting (ngVLA Memo No. 16). The off-set core, located on the northern edge of the long baseline configuration, provides excellent sensitivity even on the longest baselines. We are considering, in addition, a compact configuration of 16 close-packed 6 m antennas to obtain uv-coverage down to baselines ~ 10 m for imaging large scale structure, as well as a configuration including 9 stations distributed to continental scales.

  20. Gravitational waves from a very strong electroweak phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Leonardo; Mégevand, Ariel, E-mail: lleitao@mdp.edu.ar, E-mail: megevand@mdp.edu.ar [IFIMAR (UNMdP-CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales, UNMdP, Deán Funes 3350, (7600) Mar del Plata (Argentina)

    2016-05-01

    We investigate the production of a stochastic background of gravitational waves in the electroweak phase transition. We consider extensions of the Standard Model which can give very strongly first-order phase transitions, such that the transition fronts either propagate as detonations or run away. To compute the bubble wall velocity, we estimate the friction with the plasma and take into account the hydrodynamics. We track the development of the phase transition up to the percolation time, and we calculate the gravitational wave spectrum generated by bubble collisions, magnetohydrodynamic turbulence, and sound waves. For the kinds of models we consider, we find parameter regions for which the gravitational waves are potentially observable at the planned space-based interferometer eLISA. In such cases, the signal from sound waves is generally dominant, while that from bubble collisions is the least significant of them. Since the sound waves and turbulence mechanisms are diminished for runaway walls, the models with the best prospects of detection at eLISA are those which do not have such solutions. In particular, we find that heavy extra bosons provide stronger gravitational wave signals than tree-level terms.

  1. Homogenous BSCCO-2212 Round Wires for Very High Field Magnets

    International Nuclear Information System (INIS)

    Campbell, Scott; Holesinger, Terry; Huang, Ybing

    2012-01-01

    The performance demands on modern particle accelerators generate a relentless push towards higher field magnets. In turn, advanced high field magnet development places increased demands on superconducting materials. Nb3Sn conductors have been used to achieve 16 T in a prototype dipole magnet and are thought to have the capability for ∼18 T for accelerator magnets (primarily dipoles but also higher order multipole magnets). However there have been suggestions and proposals for such magnets higher than 20 T. The High Energy Physics Community (HEP) has identified important new physics opportunities that are enabled by extremely high field magnets: 20 to 50 T solenoids for muon cooling in a muon collider (impact: understanding of neutrinos and dark matter); and 20+ T dipoles and quadrupoles for high energy hadron colliders (impact: discovery reach far beyond present). This proposal addresses the latest SBIR solicitation that calls for grant applications that seek to develop new or improved superconducting wire technologies for magnets that operate at a minimum of 12 Tesla (T) field, with increases up to 15 to 20 T sought in the near future (three to five years). The long-term development of accelerator magnets with fields greater than 20 T will require superconducting wires having significantly better high-field properties than those possessed by current Nb 3 Sn or other A15 based wires. Given the existing materials science base for Bi-2212 wire processing, we believe that Bi 2 Sr 2 CaCu 2 O y (Bi-2212) round wires can be produced in km-long piece lengths with properties suitable to meet both the near term and long term needs of the HEP community. The key advance will be the translation of this materials science base into a robust, high-yield wire technology. While the processing and application of A15 materials have advanced to a much higher level than those of the copper oxide-based, high T c (HTS) counterparts, the HTS materials have the very significant advantage

  2. Bubble nucleation and growth in very strong cosmological phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Mégevand, Ariel, E-mail: megevand@mdp.edu.ar; Ramírez, Santiago

    2017-06-15

    Strongly first-order phase transitions, i.e., those with a large order parameter, are characterized by a considerable supercooling and high velocities of phase transition fronts. A very strong phase transition may have important cosmological consequences due to the departures from equilibrium caused in the plasma. In general, there is a limit to the strength, since the metastability of the old phase may prevent the transition to complete. Near this limit, the bubble nucleation rate achieves a maximum and thus departs from the widely assumed behavior in which it grows exponentially with time. We study the dynamics of this kind of phase transitions. We show that in some cases a gaussian approximation for the nucleation rate is more suitable, and in such a case we solve analytically the evolution of the phase transition. We compare the gaussian and exponential approximations with realistic cases and we determine their ranges of validity. We also discuss the implications for cosmic remnants such as gravitational waves.

  3. Graphene ballistic nano-rectifier with very high responsivity

    Science.gov (United States)

    Auton, Gregory; Zhang, Jiawei; Kumar, Roshan Krishna; Wang, Hanbin; Zhang, Xijian; Wang, Qingpu; Hill, Ernie; Song, Aimin

    2016-01-01

    Although graphene has the longest mean free path of carriers of any known electronic material, very few novel devices have been reported to harness this extraordinary property. Here we demonstrate a ballistic nano-rectifier fabricated by creating an asymmetric cross-junction in single-layer graphene sandwiched between boron nitride flakes. A mobility ∼200,000 cm2 V−1 s−1 is achieved at room temperature, well beyond that required for ballistic transport. This enables a voltage responsivity as high as 23,000 mV mW−1 with a low-frequency input signal. Taking advantage of the output channels being orthogonal to the input terminals, the noise is found to be not strongly influenced by the input. Hence, the corresponding noise-equivalent power is as low as 0.64 pW Hz−1/2. Such performance is even comparable to superconducting bolometers, which however need to operate at cryogenic temperatures. Furthermore, output oscillations are observed at low temperatures, the period of which agrees with the lateral size quantization. PMID:27241162

  4. Very light dilaton and naturally light Higgs boson

    Science.gov (United States)

    Hong, Deog Ki

    2018-02-01

    We study very light dilaton, arising from a scale-invariant ultraviolet theory of the Higgs sector in the standard model of particle physics. Imposing the scale symmetry below the ultraviolet scale of the Higgs sector, we alleviate the fine-tuning problem associated with the Higgs mass. When the electroweak symmetry is spontaneously broken radiatively à la Coleman-Weinberg, the dilaton develops a vacuum expectation value away from the origin to give an extra contribution to the Higgs potential so that the Higgs mass becomes naturally around the electroweak scale. The ultraviolet scale of the Higgs sector can be therefore much higher than the electroweak scale, as the dilaton drives the Higgs mass to the electroweak scale. We also show that the light dilaton in this scenario is a good candidate for dark matter of mass m D ˜ 1 eV - 10 keV, if the ultraviolet scale is about 10-100 TeV. Finally we propose a dilaton-assisted composite Higgs model to realize our scenario. In addition to the light dilaton the model predicts a heavy U(1) axial vector boson and two massive, oppositely charged, pseudo Nambu-Goldstone bosons, which might be accessible at LHC.

  5. Assessment of very high temperature reactors in process applications

    International Nuclear Information System (INIS)

    Jones, J.E. Jr.; Spiewak, I.; Gambill, W.R.

    1976-01-01

    In April 1974, the United States Energy Research and Development Administration (ERDA) authorized General Atomic Company, General Electric Company, and Westinghouse Astronuclear Laboratory to assess the available technology for producing process heat utilizing a very high temperature nuclear reactor (VHTR). The VHTR is defined as a gas-cooled graphite-moderated reactor. Oak Ridge National Laboratory has been given a lead role in evaluating the VHTR reactor studies and potential applications of the VHTR. Process temperatures up to the 760 to 871 0 C range appear to be achievable with near-term technology. The major development considerations are high temperature materials, the safety questions (especially regarding the need for an intermediate heat exchanger) and the process heat exchanger. The potential advantages of the VHTR over competing fossil energy sources are conservation of fossil fuels and reduced atmospheric impacts. Costs are developed for nuclear process heat supplied from a 3000-MW(th) VHTR. The range of cost in process applications is competitive with current fossil fuel alternatives

  6. Atmospheric pressure loading parameters from very long baseline interferometry observations

    Science.gov (United States)

    Macmillan, D. S.; Gipson, John M.

    1994-01-01

    Atmospheric mass loading produces a primarily vertical displacement of the Earth's crust. This displacement is correlated with surface pressure and is large enough to be detected by very long baseline interferometry (VLBI) measurements. Using the measured surface pressure at VLBI stations, we have estimated the atmospheric loading term for each station location directly from VLBI data acquired from 1979 to 1992. Our estimates of the vertical sensitivity to change in pressure range from 0 to -0.6 mm/mbar depending on the station. These estimates agree with inverted barometer model calculations (Manabe et al., 1991; vanDam and Herring, 1994) of the vertical displacement sensitivity computed by convolving actual pressure distributions with loading Green's functions. The pressure sensitivity tends to be smaller for stations near the coast, which is consistent with the inverted barometer hypothesis. Applying this estimated pressure loading correction in standard VLBI geodetic analysis improves the repeatability of estimated lengths of 25 out of 37 baselines that were measured at least 50 times. In a root-sum-square (rss) sense, the improvement generally increases with baseline length at a rate of about 0.3 to 0.6 ppb depending on whether the baseline stations are close to the coast. For the 5998-km baseline from Westford, Massachusetts, to Wettzell, Germany, the rss improvement is about 3.6 mm out of 11.0 mm. The average rss reduction of the vertical scatter for inland stations ranges from 2.7 to 5.4 mm.

  7. Design Study for a Staged Very Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alex W.

    2002-02-27

    Particle physics makes its greatest advances with experiments at the highest energy. The only sure way to advance to a higher-energy regime is through hadron colliders--the Tevatron, the LHC, and then, beyond that, a Very Large Hadron Collider. At Snowmass-1996 [1], investigators explored the best way to build a VLHC, which they defined as a 100 TeV collider. The goals in this study are different. The current study seeks to identify the best and cheapest way to arrive at frontier-energy physics, while simultaneously starting down a path that will eventually lead to the highest-energy collisions technologically possible in any accelerator using presently conceivable technology. This study takes the first steps toward understanding the accelerator physics issues, the technological possibilities and the approximate cost of a particular model of the VLHC. It describes a staged approach that offers exciting physics at each stage for the least cost, and finally reaches an energy one-hundred times the highest energy currently achievable.

  8. A close look at the very heart of NGC7469

    Energy Technology Data Exchange (ETDEWEB)

    Rouan, Daniel [LESIA, Observatoire de Paris, CNRS, UPMC, Universite Paris Diderot, 5 place Jules Janssen, F-92190 Meudon (France); Gratadour, Damien [Gemini Observatory, 670 N. A' ohoku PL, Hilo, Hawaii 96720 (United States)], E-mail: daniel.rouan@obspm.fr

    2008-10-15

    We observed the central regions of the well-known LIRG/Seyfert 1.2 galaxy NGC 7469 with adaptive optics, performing K band long-slit spectroscopic observations with NaCo at VLT. We concentrate here on the inner 100 pc, focusing on the structure of the NLR. The study of the continuum as well as of the molecular and ionized hydrogen emission lines shows some unexpected properties that raise several questions that we consider as different pieces of a unique puzzle. The most striking result of our study is the detection of broad ionized hydrogen emission over a 45pc radius around the central source with a symmetric behaviour with respect to the central core. We also detect molecular hydrogen in the innermost part of this Seyfert nuclei. The continuum emission corresponds to a very hot black body. We interpret all those facts as due to some Thomson scattering by electrons of the NLR. The temperature evolution is in good agreement with this interpretation and the electron density we derive is compatible with densities found in NLRs of typical AGNs.

  9. Recent developments in very low energy neutron technology

    International Nuclear Information System (INIS)

    Utsuro, Masahiko; Kawabata, Yuji; Yamaguchi, Akira; Yoshiki, Hajime.

    1993-01-01

    In this report, the recent state of the research and technical development of the neutrons in the energy region below 0.5 meV is introduced. The neutrons in this region are further divided into very cold neutrons (VCN) and ultracold neutrons (UCN). The UCNs are known by such characteristic behavior that they can be confined in a neutron bottle for long time. The attempt to verify the break of T conversion symmetry using neutrons is carried out. The experiment to show the break of T conversion symmetry by grasping the asymmetry of particle emission accompanying the beta decay of polarized neutrons is conceivable. In these cases, the use of UCNs in neutron bottles is effective. The optical properties of VCNs and UCNs are peculiar and resemble to those of light. The only VCN source in Japan is installed in the liquid deuterium CN source in the graphite facility of the KUR. VCNs are taken out from the reactor, and are converted to UCNs using a neutron turbine. The characteristics of an UCN bottle were measured, and the life of neutrons was determined as 887.6 ± 3s. The UCN experiment using superfluid helium was carried out, and the application of gravity to UCN spectrometry was developed as NESSIE. (K.I.)

  10. Very high performance pseudo-random number generation on DAP

    Science.gov (United States)

    Smith, K. A.; Reddaway, S. F.; Scott, D. M.

    1985-07-01

    Since the National DAP Service began at QMC in 1980, extensive use has been made of pseudo-random numbers in Monte Carlo simulation. Matrices of uniform numbers have been produced by various generators: (a) multiplicative ( x+ 1 = 13 13xn mod 2 59); (b) very long period shift register ( x4423 + x271 + 1); (c) multiple shorter period ( x127 + x7 + 1) shift registers generating several matrices per iteration. The above uniform generators can also feed a normal distribution generator that uses the Box-Muller transformation. This paper describes briefly the generators, their implementation and speed. Generator (b) has been greatly speeded-up by re-implementation, and now produces more than 100 × 10 6 high quality 16-bit numbers/s. Generator (c) is under development and will achieve even higher performance, mainly due to producing data in greater bulk. High quality numbers are expected, and performance will range from 400 to 800 × 10 6 numbers/s, depending on how the generator is used.

  11. Development of very high temperature reactor design technology

    International Nuclear Information System (INIS)

    Lee, Won Jae; Noh, Jan Man

    2012-04-01

    or an efficient production of nuclear hydrogen, the VHTR (Very High Temperature Gas-cooled Reactor) of 950 .deg. C outlet temperature and the interfacing system for the hydrogen production are required. We have developed various evaluation technologies for the performance and safety of VHTR through the accomplishment of this project. First, to evaluate the performance of VHTR, a series of analyses has been performed such as core characteristics at 950 .deg. C, applicability of cooled-vessel, intermediate loop system and high temperature structural integrity. Through the analyses of major accidents such as HPCC and LPCC and the analysis of the risk/performance-informed method, VHTR safety evaluation has been also performed. In addition, various design analysis codes have been developed for a nuclear design, system loop design, system performance analysis, fission product/tritium transport analysis, core thermo-fluid analysis, system layout analysis, graphite structure seismic analysis and hydrogen exposion analysis, and they are being verified and validated through a lot of international collaborations

  12. Models & Searches of CPT Violation: a personal, very partial, list

    Science.gov (United States)

    Mavromatos, Nick E.

    2018-01-01

    In this talk, first I motivate theoretically, and then I review the phenomenology of, some models entailing CPT Violation (CPTV). The latter is argued to be responsible for the observed matter-antimatter asymmetry in the Cosmos, and may owe its origin to either Lorentz-violating background geometries, whose effects are strong in early epochs of the Universe but very weak today, being temperature dependent in general, or to an ill-defined CPT generator in some quantum gravity models entailing decoherence of quantum matter as a result of quantum degrees of freedom in the gravity sector that are inaccessible to the low-energy observers. In particular, for the latter category of CPTV, I argue that entangled states of neutral mesons (Kaons or B-systems), of central relevance to KLOE-2 experiment, can provide smoking-gun sensitive tests or even falsify some of these models. If CPT is ill-defined one may also encounter violations of the spin-statistics theorem, with possible consequences for the Pauli Exclusion Principle, which I only briefly touch upon.

  13. Metabolic effects of fasting and very low calorie diets

    International Nuclear Information System (INIS)

    Henson, L.C.

    1986-01-01

    To examine the mechanism of nitrogen sparing in obese subjects on very low calorie diets (VLC-PS), effects of total fasting (TF) and VLC-PS (380 Kcal/day) supplying protein without carbohydrate on metabolites, hormones, urea nitrogen excretion, and plasma [3- 3 H]glucose turnover, [U- 14 C]lysine flux, and [1- 14 C]leucine flux and oxidation were compared. Subjects with a wide range of relative obesity were studied during a control period and after one week of TF. Urea excretion and lysine flux decreased in all subjects, while 3-methylhistidine excretion was unchanged. Glucagon:insulin ratio and cortisol increased, while triiodothyronine (T 3 ) decreased and would be expected to be nitrogen-sparing. In a separate study, groups of obese women were studied during a control period and during 14 days of TF or VLC-PS supplying either 80 g (80G) or 40 g (40G) high-quality protein. Increases in branched chain amino acids, β-hydroxybutyrate, and glucagon:insulin ratio and decrease in T 3 did not differ among groups. Glucose production decreased to the same extent in all groups. Serum and urinary urea nitrogen were maintained at control values throughout the diet in 80G but decreased to the same extent in TF and 40G. Nitrogen balance estimated from urea nitrogen appearance was negative in all groups

  14. A uniquely specialized ear in a very early tetrapod.

    Science.gov (United States)

    Clack, J A; Ahlberg, P E; Finney, S M; Dominguez Alonso, P; Robinson, J; Ketcham, R A

    2003-09-04

    The Late Devonian genus Ichthyostega was for many decades the earliest known tetrapod, and the sole representative of a transitional form between a fish and a land vertebrate. However, despite being known since 1932 (ref. 1) from a large collection of specimens, its morphology remained enigmatic and not what was expected of a very primitive tetrapod. Its apparent specializations led it to be considered as a "blind offshoot" or "sidebranch" off the tetrapod family tree, and recent cladistic analyses have disagreed about its exact phylogenetic position within the tetrapod stem group. In particular, its braincase and ear region defied interpretation, such that conventional anatomical terms seemed inapplicable. Using new material collected in 1998 (ref. 9), preparation of earlier-collected material, and high-resolution computed tomography scanning, here we identify and interpret these problematic anatomical structures. They can now be seen to form part of a highly specialized ear, probably a hearing device for use in water. This represents a structurally and functionally unique modification of the tetrapod otic region, unlike anything seen in subsequent tetrapod evolution. The presence of deeply grooved gill bars as in its contemporary Acanthostega suggest that Ichthyostega may have been more aquatically adapted than previously believed.

  15. The Silicon Ministrip Detector of the DELPHI Very Forward Tracker

    CERN Document Server

    AUTHOR|(CDS)2067985

    1996-01-01

    The subject of this work is the design, test and construction of a new silicon tracking detector for the extreme forward region of the DELPHI experiment at LEP. I joined the Very Forward Tracker (VFT) Ministrip group in 1993, at a time when the upgrade of the DELPHI tracking system was proposed. My first task was to participate in the design of the ministrip detector for the VFT. This included the optimisation of the detector layout in simulations and the study of prototype detectors in the testbeam. In 1994 I became responsible for the tests and assembly' of the VFT ministrip detector at CERN. The main focus of my work was the study of the performance of a large variety of detectors in beam tests. This included the preparation of the test setup, the tests of different detectors and the analysis of the measurements. With these measurements it is possible to compare the advantages and disadvantages of various new layouts for large pitch silicon strip detectors. In particular the signal response and spatial res...

  16. Reliability-Based Optimal Design for Very Large Floating Structure

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-hua(张淑华); FUJIKUBO Masahiko

    2003-01-01

    Costs and losses induced by possible future extreme environmental conditions and difficulties in repairing post-yielding damage strongly suggest the need for proper consideration in design rather than just life loss prevention. This can be addressed through the development of design methodology that balances the initial cost of the very large floating structure (VLFS) against the expected potential losses resulting from future extreme wave-induced structural damage. Here, the development of a methodology for determining optimal, cost-effective design will be presented and applied to a VLFS located in the Tokyo bay. Optimal design criteria are determined based on the total expected life-cycle cost and acceptable damage probability and curvature of the structure, and a set of sizes of the structure are obtained. The methodology and applications require expressions of the initial cost and the expected life-cycle damage cost as functions of the optimal design variables. This study includes the methodology, total life-cycle cost function, structural damage modeling, and reliability analysis.

  17. Models & Searches of CPT Violation: a personal, very partial, list

    Directory of Open Access Journals (Sweden)

    Mavromatos Nick E.

    2018-01-01

    Full Text Available In this talk, first I motivate theoretically, and then I review the phenomenology of, some models entailing CPT Violation (CPTV. The latter is argued to be responsible for the observed matter-antimatter asymmetry in the Cosmos, and may owe its origin to either Lorentz-violating background geometries, whose effects are strong in early epochs of the Universe but very weak today, being temperature dependent in general, or to an ill-defined CPT generator in some quantum gravity models entailing decoherence of quantum matter as a result of quantum degrees of freedom in the gravity sector that are inaccessible to the low-energy observers. In particular, for the latter category of CPTV, I argue that entangled states of neutral mesons (Kaons or B-systems, of central relevance to KLOE-2 experiment, can provide smoking-gun sensitive tests or even falsify some of these models. If CPT is ill-defined one may also encounter violations of the spin-statistics theorem, with possible consequences for the Pauli Exclusion Principle, which I only briefly touch upon.

  18. SWIFTS: on-chip very high spectral resolution spectrometer

    Science.gov (United States)

    le Coarer, E.; Venancio, L. G.; Kern, P.; Ferrand, J.; Puget, P.; Ayraud, M.; Bonneville, C.; Demonte, B.; Morand, A.; Boussey, J.; Barbier, D.; Blaize, S.; Gonthiez, T.

    2017-11-01

    The size and the weight of state of the art spectrometers is a serious issue regarding space applications. SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer) is a new FTS family without any moving part. This very promising technology is an original way to fully sample the Fourier interferogram obtained in a waveguide by either a reflection (SWIFTS Lippmann) or counter-propagative (SWIFTS Gabor) interference phenomenon. The sampling is simultaneously performed the optical path thanks to "nano-detectors" located in the evanescent field of the waveguide. For instance a 1.7cm long waveguide properly associated to the detector achieves directly a resolution of 0.13cm-1 on a few centimetre long instruments. Here, firstly we present the development status of this new kind of spectrometers and the first results obtained with on going development of spectrometer covering simultaneously the visible domain from 400 to 1000 nm like an Echelle spectrometer. Valuable technologies allows one to extend the concept to various wavelength domains. Secondly, we present the results obtained in the frame of an activity funded by the European Space Agency where several potential applications in space missions have been identified and studied.

  19. Recirculating steam generator operation at very low power

    International Nuclear Information System (INIS)

    Holcblat, A.

    2001-01-01

    The behaviour of recirculating SG's at very low power has been thoroughly investigated by laboratory and on-site tests as well as numerical simulations. A special experimental program dedicated to recirculation threshold determination has been performed on the Freon SG mock-up CLOTAIRE. These laboratory data are completed with transients of feedwater injections at hot stand-by on two instrumented SG's, one boiler type SG and one economizer type SG. The phenomena are different on both types. In boiler SG's, the SG behaves like a U-tube and recirculation stops around 2% load at stand-by temperature and water level. In economizer SG's, the presence of 2 separate down-comers and a divider plate inside the tube bundle allows a recirculation loop by-passing the separators. The mixing of saturated and cold water induced by this loop limits down-comer cooling and thus alleviates the thermal load on the tube sheet. These tests were used to validate the SG transient analysis 1-D code ANETH. (author)

  20. Antibiotic Therapy for Very Low Birth Weigh Newborns in NICU

    Science.gov (United States)

    Afjeh, Seyyed-Abolfazl; Sabzehei, Mohammad-Kazem; Fahimzad, Seyyed-Ali-Reza; Shiva, Farideh; Shamshiri, Ahmad-Reza; Esmaili, Fatemeh

    2016-01-01

    Background Prolonged empiric antibiotics therapy in neonates results in several adverse consequences including widespread antibiotic resistance, late onset sepsis (LOS), necrotizing enterocolitis (NEC), prolonged hospital course (HC) and increase in mortality rates. Objectives To assess the risk factors and the outcome of prolonged empiric antibiotic therapy in very low birth weight (VLBW) newborns. Materials and Methods Prospective study in VLBW neonates admitted to NICU and survived > 2 W, from July 2011 - June 2012. All relevant perinatal and postnatal data including duration of antibiotics therapy (Group I 2W) and outcome up to the time of discharge or death were documented and compared. Results Out of 145 newborns included in the study, 62 were in group I, and 83 in Group II. Average duration of antibiotic therapy was 14 days (range 3 - 62 days); duration in Group I and Group II was 10 ± 2.3 vs 25.5 ± 10.5 days. Hospital stay was 22.3 ± 11.5 vs 44.3 ± 14.7 days, respectively. Multiple regression analysis revealed following risk factors as significant for prolonged empiric antibiotic therapy: VLBW especially stage II, 12 (8.3%) newborns died. Infant mortality alone and with LOS/NEC was higher in group II as compared to group I (P < 0.002 and < 0.001 respectively). Conclusions Prolonged empiric antibiotic therapy caused increasing rates of LOS, NEC, HC and infant mortality. PMID:27307961

  1. Glycerin Suppositories Use in Very Low Birth Weight Infants.

    Science.gov (United States)

    Patel, Shalinkumar; Dereddy, Narendra; Talati, Ajay J; Gaston, Kan; Dhanireddy, Ramasubbareddy

    2017-01-01

    Objective  To study the characteristics of very low birth weight (VLBW) infants receiving glycerin suppositories (GS) and evaluate the association of GS use with outcomes. Study Design  This is a retrospective study of VLBW infants admitted to a level III neonatal intensive care unit. Infants with birth weight between 500 and 1,499 g were evaluated. We evaluated the frequency of GS use and compared the characteristics and outcomes of the GS group with the no-GS group. Multivariate analyses controlling for gestational age and small for gestational age status were performed to study the effect of GS on outcomes. Results  A total of 1,073 infants were included in the study. Out of those, 527 (49.1%) infants received GS. Incidence of necrotizing enterocolitis was not significantly different between the two groups, while days to reach full enteral feeds and length of hospital stay were significantly longer in the GS group. Conclusion  Frequent use of GS warrants further prospective studies to evaluate its safety and efficacy in view of our study showing association with longer time to reach full enteral feeds. We speculate that GS use could be a marker for gastrointestinal dysmotility and hence the association with unfavorable clinical outcomes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  2. Probing Fundamental Symmetries: Questioning the Very Basics of Conservation Laws

    Science.gov (United States)

    Mohanmurthy, Prajwal

    2017-09-01

    Is the Lorentz-CPT symmetry, a core component of the standard model, valid? To what extent are the CP and T symmetries broken in the strong sector? What are we doing about the existing strong-CP problem? Do neutrons oscillate (like neutral kaons) or break the (Baryon - Lepton) number conservation? In this presentation, we will go over some of the experiments probing fundamental symmetries trying to answer the above questions. I will, very briefly, introduce the CompEx & nEx experiments probing the Lorentz symmetry in the electromagnetic (EM) sector, the nEDM experiment probing CP and T symmetries in the strong sector, NStar experiment searching for neutron oscillations, MASS & BDX experiments searching for axion like particles & dark matter. We will then briefly touch upon the highlights of these experiments and focus on the path we are taking towards answering those questions while also connecting the dots [experiments] with CEU. PM would like to acknowledge support from SERI SNSF Grant 2015.0594.

  3. Superconducting accelerating structures for very low velocity ion beams

    Directory of Open Access Journals (Sweden)

    J. Xu

    2008-03-01

    Full Text Available This paper presents designs for four types of very-low-velocity superconducting (SC accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006

  4. Very high frequency (beyond 100 MHz) PZT kerfless linear arrays.

    Science.gov (United States)

    Wu, Da-Wei; Zhou, Qifa; Geng, Xuecang; Liu, Chang-Geng; Djuth, Frank; Shung, K Kirk

    2009-10-01

    This paper presents the design, fabrication, and measurements of very high frequency kerfless linear arrays prepared from PZT film and PZT bulk material. A 12-microm PZT thick film fabricated from PZT-5H powder/solution composite and a piece of 15-microm PZT-5H sheet were used to fabricate 32-element kerfless high-frequency linear arrays with photolithography. The PZT thick film was prepared by spin-coating of PZT sol-gel composite solution. The thin PZT-5H sheet sample was prepared by lapping a PZT-5H ceramic with a precision lapping machine. The measured results of the 2 arrays were compared. The PZT film array had a center frequency of 120 MHz, a bandwidth of 60% with a parylene matching layer, and an insertion loss of 41 dB. The PZT ceramic sheet array was found to have a center frequency of 128 MHz with a poorer bandwidth (40% with a parylene matching layer) but a better sensitivity (28 dB insertion loss).

  5. Elastic scattering and total cross section at very high energies

    International Nuclear Information System (INIS)

    Castaldi, R.; Sanguinetti, G.

    1985-01-01

    The aim of this review is to summarize the recent progress in the field of elastic scattering and total cross section in this new energy domain. In Section 2 a survey of the experimental situation is outlined. The most significant data are presented, with emphasis on the interpretation, not the specific details or technicalities. This section is therefore intended to give a self-contained look at the field, especially for the nonspecialist. In Section 3, hadron scattering at high energy is described in an impact parameter picture, which provides a model-independent intuitive geometrical representation. The diffractive character of elastic scattering, seen as the shadow of inelastic absorption, is presented as a consequence of unitarity in the s-channel. Spins are neglected throughout this review, inasmuch as the asymptotic behavior in the very high-energy limit is the main concern here. In Section 4 some relevant theorems are recalled on the limiting behavior of hadron-scattering amplitudes at infinite energy. There is also a brief discussion on how asymptotically rising total cross sections imply scaling properties in the elastic differential cross sections. A quick survey of eikonal models is presented and their predictions are compared with ISR and SPS Collider data

  6. Multiple Myeloma in the Very Old: An IASIA Conference Report

    Science.gov (United States)

    Shapiro, Gary R.; Ershler, William B.; Badros, Ashraf; Cohen, Harvey J.; Dispenzieri, Angela; Flores, Irene Q.; Kanapuru, Bindu; Jurivich, Donald; Longo, Dan L.; Nourbakhsh, Ali; Palumbo, Antonio; Walston, Jeremy; Yates, Jerome W.

    2014-01-01

    Multiple myeloma (MM) in patients aged greater than 80 years poses an increasingly common challenge for oncology providers. A multidisciplinary workshop was held in which MM-focused hematologists/oncologists, geriatricians, and associated health-care team members discussed the state of research for MM therapy, as well as themes from geriatric medicine that pertain directly to this patient population. A summary statement of our discussions is presented here, in which we highlight several topics. MM disproportionately affects senior adults, and demographic trends indicate that this trend will accelerate. Complex issues impact cancer in seniors, and although factors such as social environment, comorbidities, and frailty have been well characterized in nononcological geriatric medicine, these themes have been inadequately explored in cancers such as MM, despite their clear relevance to this field. Therapeutically, novel agents have improved survival for MM patients of all ages, but less so for seniors than younger patients for a variety of reasons. Lastly, both MM- and treatment-related symptoms and toxicities require special attention in senior adults. Existing research provides limited insight into how best to manage these often complex patients, who are often not reflected in typical clinical trial populations. We hence offer suggestions for clinical trials that address knowledge gaps in how to manage very old and/or frail patients with MM, given the complicated issues that often surround this patient population. PMID:24700806

  7. Neurologic Outcomes in Very Preterm Infants Undergoing Surgery.

    LENUS (Irish Health Repository)

    2012-01-31

    OBJECTIVE: To investigate the relationship between surgery in very preterm infants and brain structure at term equivalent and 2-year neurodevelopmental outcome. STUDY DESIGN: A total of 227 infants born at <30 weeks gestation or at a birth weight of <1250 g were prospectively enrolled into a longitudinal observational cohort for magnetic resonance imaging and developmental follow-up. The infants were categorized retrospectively into either a nonsurgical group (n=178) or a surgical group (n=30). Nineteen infants were excluded because of incomplete or unsuitable data. The surgical and nonsurgical groups were compared in terms of clinical demographic data, white matter injury, and brain volume at term. Neurodevelopmental outcome was assessed at age 2 years. RESULTS: Compared with the nonsurgical group, the infants in the surgical group were smaller and more growth-restricted at birth, received more respiratory support and oxygen therapy, and had longer hospital stays. They also had smaller brain volumes, particularly smaller deep nuclear gray matter volumes. Infants who underwent bowel surgery had greater white matter injury. Mental Developmental Index scores were lower in the surgical group, whereas Psychomotor Developmental Index scores did not differ between the groups. The Mental Developmental Index difference became nonsignificant after adjustment for confounding variables. CONCLUSION: Preterm infants exposed to surgery and anesthesia had greater white matter injury and smaller total brain volumes, particularly smaller deep nuclear gray matter volumes. Surgical exposure in the preterm infant should alert the clinician to an increased risk for adverse cognitive outcome.

  8. Very-high-temperature gas reactor environmental impacts assessment

    International Nuclear Information System (INIS)

    Baumann, C.D.; Barton, C.J.; Compere, E.L.; Row, T.H.

    1977-08-01

    The operation of a Very High Temperature Reactor (VHTR), a slightly modified General Atomic type High Temperature Gas-Cooled Reactor (HTGR) with 1600 F primary coolant, as a source of process heat for the 1400 0 F steam-methanation reformer step in a hydrogen producing plant (via hydrogasification of coal liquids) was examined. It was found that: (a) from the viewpoint of product contamination by fission and activation products, an Intermediate Heat Exchanger (IHX) is probably not necessary; and (b) long term steam corrosion of the core support posts may require increasing their diameter (a relatively minor design adjustment). However, the hydrogen contaminant in the primary coolant which permeates the reformer may reduce steam corrosion but may produce other problems which have not as yet been resolved. An IHX in parallel with both the reformer and steam generator would solve these problems, but probably at greater cost than that of increasing the size of the core support posts. It is recommended that this corrosion problem be examined in more detail, especially by investigating the performance of current fossil fuel heated reformers in industry. Detailed safety analysis of the VHTR would be required to establish definitely whether the IHX can be eliminated. Water and hydrogen ingress into the reactor system are potential problems which can be alleviated by an IHX. These problems will require analysis, research and development within the program required for development of the VHTR

  9. Growth and development in children born very low birthweight.

    Science.gov (United States)

    Scharf, Rebecca J; Stroustrup, Annemarie; Conaway, Mark R; DeBoer, Mark D

    2016-09-01

    To examine the relationships between growth (birth to age 2 years) and developmental outcomes in children born with very low birthweight (VLBW). Motor and mental development in children born with VLBW were regressed on anthropometric measurements at birth, 9 months and 2 years using multivariable regression. The Early Childhood Longitudinal Study-Birth Cohort, a longitudinal cohort, community sample, designed to be representative of children born across the USA. 950 children born with VLBW (children exhibited poor growth, with length-for-age z-scores children at 9 months (adjusted for prematurity) and 34.2% of children at 2 years. Compared with children having z-scores >-2, children with growth shortfalls in head circumference, length and weight had a higher adjusted OR (aOR) of low Bayley motor scores at 9 months and 2 years (aOR ranging from 1.8 to 3.3, all pchildren born with VLBW. While careful length measures may be a particularly useful marker, deficits in all anthropometric measures were risk factors for developmental delays. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  10. Social development of children born very preterm: a systematic review.

    Science.gov (United States)

    Ritchie, Kirsten; Bora, Samudragupta; Woodward, Lianne J

    2015-10-01

    To review systematically studies examining the development of social competence in children born very preterm (VPT) (gestation skills. Twenty-three studies were included. Seven focused on social competence and another 16 examined social competence within a range of outcomes. Study quality was low. Limitations included reliance on single informant data, cross-sectional measurement, use of brief screening tools, absence of child or peer report, and no conceptual model. In terms of social adjustment, 16 out of 21 studies found children born VPT had more peer problems and social withdrawal. Findings of social performance were mixed, with some studies suggesting differences in prosocial behavior (4/14) and others not. Social skills were assessed in four studies and showed children born VPT had poorer skills than children born at term. Predictors of social competence included gestational age, neonatal brain abnormalities, and family socio-economic status. Children born VPT have poorer social competence. These difficulties emerge early and persist throughout childhood. © 2015 Mac Keith Press.

  11. Overlap of electron core states for very high compressions

    International Nuclear Information System (INIS)

    Straub, G.

    1985-01-01

    At normal density and for modest compressions, the electronic structure of a metal can be accurately described by treating the conduction electrons and their interactions with the usual methods of band theory. The core electrons remain essentially the same as for an isolated free atom and do not participate in the bonding forces responsible for creating a condensed phase. As the density increases, the core electrons begin to ''see'' one another as the overlap of the tails of wave functions can no longer be neglected. The electronic structure of the core electrons is responsible for an effective repulsive interaction that eventually becomes free-electron-like at very high compressions. The electronic structure of the interacting core electrons may be treated in a simple manner using the Atomic Surface Method (ASM). The ASM is a first-principles treatment of the electronic structure involving a rigorous integration of the Schroedinger equation within the atomic-sphere approximation. Solid phase wave functions are constructed from isolated atom wave functions and the band width W/sub l/ and the center of gravity of the band C/sub l/ are obtained from simple formulas. The ASM can also utilize analytic forms of the atomic wave functions and thus provide direct functional dependence of various aspects of the electronic structure. Of particular use in understanding the behavior of the core electrons, the ASM provides the analytic density dependence of the band widths and positions. 8 refs., 2 figs., 1 tab

  12. Gravity sensing using Very Long Baseline Atom Interferometry

    Science.gov (United States)

    Schlippert, D.; Wodey, E.; Meiners, C.; Tell, D.; Schubert, C.; Ertmer, W.; Rasel, E. M.

    2017-12-01

    Very Long Baseline Atom Interferometry (VLBAI) has applications in high-accuracy absolute gravimetry, gravity-gradiometry, and for tests of fundamental physics. Thanks to the quadratic scaling of the phase shift with increasing free evolution time, extending the baseline of atomic gravimeters from tens of centimeters to meters puts resolutions of 10-13g and beyond in reach.We present the design and progress of key elements of the VLBAI-test stand: a dual-species source of Rb and Yb, a high-performance two-layer magnetic shield, and an active vibration isolation system allowing for unprecedented stability of the mirror acting as an inertial reference. We envisage a vibration-limited short-term sensitivity to gravitational acceleration of 1x10-8 m/s-2Hz-1/2 and up to a factor of 25 improvement when including additional correlation with a broadband seismometer. Here, the supreme long-term stability of atomic gravity sensors opens the route towards competition with superconducting gravimeters. The operation of VLBAI as a differential dual-species gravimeter using ultracold mixtures of Yb and Rb atoms enables quantum tests of the universality of free fall (UFF) at an unprecedented level of <10-13, potentially surpassing the best experiments to date.

  13. Very low cost multichannel analyzer with some additional features

    Energy Technology Data Exchange (ETDEWEB)

    Tudyka, Konrad, E-mail: konrad.tudyka@polsl.pl [Centre of Excellence-Gliwice Absolute Dating Methods Centre, Institute of Physics, Silesian University of Technology (Poland); Bluszcz, Andrzej [Centre of Excellence-Gliwice Absolute Dating Methods Centre, Institute of Physics, Silesian University of Technology (Poland)

    2011-12-11

    In this paper we present a multichannel analyzer (MCA) based on a digital signal controller (DSC). The multichannel analyzer is characterized by a very low cost and an additional feature of recording time intervals between pulses. The total cost of electronic parts used in construction of the MCA is around 50 USD. The electronic circuit is based on dsPIC30F2020 DSC unit from Microchip. The device has a 10-bit analogue-to-digital converter (ADC) which can sample and convert 2 samples per {mu}s. The DSC samples the input voltage continuously and detects incoming pulses. The data belonging to a detected pulse and its time stamp are sent to a PC on-line. The analysis of data stored on the PC is performed off-line with the help of a genetic algorithm (GA) used to fit the pulse shape function. This allows determination of amplitude of each individual pulse. The effective resolution varies with the pulse length and is typically 1000 channels for pulses approximately 4{mu}s long.

  14. Development of Very High Temperature Reactor Design Technology

    International Nuclear Information System (INIS)

    Lee, Won Jae; Noh, J. M.; Kim, K. S.

    2007-05-01

    To develop design technologies for the VHTR (Very High Temperature Gas-cooled Reactor) of 950 .deg. C outlet temperature for an efficient hydrogen production, key studies were performed, which include evaluation technology for the performance and safety of VHTR, and development of design and analysis codes. First, to evaluate the performance of VHTR, a series of analyses has been carried out for core characteristics at 950 .deg. C, cooled-vessel adopting internal flow path through the graphite structure, compact heat exchanger with periodic channel configuration, intermediate loop system, risk/performance-informed method, and high temperature structural integrity. Through the analyses of major accidents such as HPCC and LPCC, safety evaluation of both VHTR and RCCS has been also performed. In addition, prototype codes have been developed for a nuclear design, system loop design, system performance analysis, air-ingress accident analysis, fission product/tritium transport analysis, graphite structure seismic analysis and hydrogen explosion analysis, and they are being verified and validated through a lot of international collaborations

  15. Very low conductivity self-hardening slurry for permanent enclosures

    International Nuclear Information System (INIS)

    Tallard, G.

    1997-01-01

    Attapulgite clay and ground blast furnace slag cement can form a low solids slurry which, after setting and curing, exhibits very low permeability and substantial strength. Compared to better known cement bentonite slurries, the conductivity is 3 orders of magnitude lower and the strength is four times higher at a similar solids content. Coefficients of permeability have been measured in the 10 -10 cm/sec. range. As a containment barrier, no chemical compound has had detrimental effects on the integrity of the material. Compatibility with leachates at a pH under 2 has been demonstrated. Compared to leachable Ordinary Portland Cement and to bentonite gel shrinkage in the presence of certain organic compounds, the attapulgite clay and the selected slag cement behave as remarkably inert. A number of successful applications as vertical barriers, trenched and by the vibrated beam method, have been installed at remedial sites. Applications by jet grouting have been implemented under utilities to provide continuity. The potential for placement of such materials to form horizontal barriers by jet grouting or frac-grouting/mud jacking techniques, offers the possibility of creating complete enclosures in soils. The purely mineral nature of these slurries ensures long term chemical stability necessary for permanent containment

  16. Implant-supported Mandibular Overdentures in Very Old Adults

    Science.gov (United States)

    Müller, F.; Duvernay, E.; Loup, A.; Vazquez, L.; Herrmann, F.R.; Schimmel, M.

    2013-01-01

    The purpose of this study was (1) to investigate denture satisfaction following the conversion of existing mandibular complete dentures to implant overdentures (IOD) in very old edentulous patients who depend on help for activities of daily living and (2) to evaluate secondary end points, such as functional, structural, nutritional, and patient-centered aspects. For this randomized clinical trial, 2 interforaminal short implants were placed in the intervention group (n = 16, 85.0 ± 6.19 yrs) to retain mandibular IODs; the control group (n = 18, 84.1 ± 5.55 yrs) received conventional relines. During the first year, no implant was lost; however, 2 patients died. IODs proved more stable, and participants in the intervention group demonstrated significantly higher denture satisfaction as well as an increased oral health–related quality of life compared to the control group. Maximum voluntary bite force improved significantly with IODs, yet the chewing efficiency was not different between groups. Masseter muscle thickness increased with IODs, mainly on the preferred chewing side. Body mass index decreased in both groups, but the decline tended to be smaller in the intervention group; blood markers and the Mini Nutritional Assessment did not confirm this tendency. These results indicate that edentulous patients who depend on help for activities of daily living may benefit from IODs even late in life (ClinicalTrial.gov NCT01928004). PMID:24158342

  17. Experimental Summary: Very High Energy Cosmic Rays and their Interactions

    Directory of Open Access Journals (Sweden)

    Kampert Karl-Heinz

    2013-06-01

    Full Text Available The XVII International Symposium on Very High Energy Cosmic Ray Interactions, held in August of 2012 in Berlin, was the first one in the history of the Symposium,where a plethora of high precision LHC data with relevance for cosmic ray physics was presented. This report aims at giving a brief summary of those measurements andit discusses their relevance for observations of high energy cosmic rays. Enormous progress has been made also in air shower observations and in direct measurements of cosmic rays, exhibiting many more structure in the cosmic ray energy spectrum than just a simple power law with a knee and an ankle. At the highest energy, the flux suppression may not be dominated by the GZK-effect but by the limiting energy of a nearby source or source population. New projects and application of new technologies promise further advances also in the near future. We shall discuss the experimental and theoretical progress in the field and its prospects for coming years.

  18. GUTs and supersymmetric GUTs in the very early universe

    International Nuclear Information System (INIS)

    Ellis, J.

    1982-10-01

    This talk is intended as background material for many of the other talks treating the possible applications of GUTs to the very early universe. I start with a review of the present theoretical and phenomenological status of GUTs before going on to raise some new issues for their prospective cosmological applications which arise in supersymmetric (susy) GUTs. The first section is an update on conventional GUTs, which is followed by a reminder of some of the motivations for going supersymmetric. There then follows a simple primer on susy and a discussion of the structure and phenomenology of simple sysy GUTs. Finally we come to the cosmological issues, including problems arising from the degeneracy of susy minima, baryosynthesis and supersymmetric inflation, the possibility that gravity is an essential complication in constructing susy GUTs and discussing their cosmology, and the related question of what mass range is allowed for the gravitino. Several parts of this write-up contain new material which has emerged either during the Workshop or subsequently. They are included here for completeness and the convenience of the prospective reader. Wherever possible, these anachronisms will be flagged so as to keep straight the historical record

  19. Superconducting accelerating structures for very low velocity ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Shepard, K.W.; Ostroumov, P.N.; Fuerst, J.D.; Waldschmidt, G.; /Argonne; Gonin, I.V.; /Fermilab

    2008-01-01

    This paper presents designs for four types of very-low-velocity superconducting accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006 < v/c < 0.06. Superconducting TEM-class cavities have been widely applied to CW acceleration of ion beams. SC linacs can be formed as an array of independently-phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the US and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front-end of such linacs, particularly for the post-acceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008 < {beta} = v/c < 0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  20. Vision for single flux quantum very large scale integrated technology

    International Nuclear Information System (INIS)

    Silver, Arnold; Bunyk, Paul; Kleinsasser, Alan; Spargo, John

    2006-01-01

    Single flux quantum (SFQ) electronics is extremely fast and has very low on-chip power dissipation. SFQ VLSI is an excellent candidate for high-performance computing and other applications requiring extremely high-speed signal processing. Despite this, SFQ technology has generally not been accepted for system implementation. We argue that this is due, at least in part, to the use of outdated tools to produce SFQ circuits and chips. Assuming the use of tools equivalent to those employed in the semiconductor industry, we estimate the density of Josephson junctions, circuit speed, and power dissipation that could be achieved with SFQ technology. Today, CMOS lithography is at 90-65 nm with about 20 layers. Assuming equivalent technology, aggressively increasing the current density above 100 kA cm -2 to achieve junction speeds approximately 1000 GHz, and reducing device footprints by converting device profiles from planar to vertical, one could expect to integrate about 250 M Josephson junctions cm -2 into SFQ digital circuits. This should enable circuit operation with clock frequencies above 200 GHz and place approximately 20 K gates within a radius of one clock period. As a result, complete microprocessors, including integrated memory registers, could be fabricated on a single chip

  1. Vision for single flux quantum very large scale integrated technology

    Energy Technology Data Exchange (ETDEWEB)

    Silver, Arnold [Northrop Grumman Space Technology, One Space Park, Redondo Beach, CA 90278 (United States); Bunyk, Paul [Northrop Grumman Space Technology, One Space Park, Redondo Beach, CA 90278 (United States); Kleinsasser, Alan [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Spargo, John [Northrop Grumman Space Technology, One Space Park, Redondo Beach, CA 90278 (United States)

    2006-05-15

    Single flux quantum (SFQ) electronics is extremely fast and has very low on-chip power dissipation. SFQ VLSI is an excellent candidate for high-performance computing and other applications requiring extremely high-speed signal processing. Despite this, SFQ technology has generally not been accepted for system implementation. We argue that this is due, at least in part, to the use of outdated tools to produce SFQ circuits and chips. Assuming the use of tools equivalent to those employed in the semiconductor industry, we estimate the density of Josephson junctions, circuit speed, and power dissipation that could be achieved with SFQ technology. Today, CMOS lithography is at 90-65 nm with about 20 layers. Assuming equivalent technology, aggressively increasing the current density above 100 kA cm{sup -2} to achieve junction speeds approximately 1000 GHz, and reducing device footprints by converting device profiles from planar to vertical, one could expect to integrate about 250 M Josephson junctions cm{sup -2} into SFQ digital circuits. This should enable circuit operation with clock frequencies above 200 GHz and place approximately 20 K gates within a radius of one clock period. As a result, complete microprocessors, including integrated memory registers, could be fabricated on a single chip.

  2. UVES Investigates the Environment of a Very Remote Galaxy

    Science.gov (United States)

    2002-03-01

    Surplus of Intergalactic Material May Be Young Supercluster Summary Observations with ESO's Very Large Telescope (VLT) have enabled an international group of astronomers [1] to study in unprecedented detail the surroundings of a very remote galaxy, almost 12 billion light-years distant [2]. The corresponding light travel time means that it is seen at a moment only about 3 billion years after the Big Bang. This galaxy is designated MS 1512-cB58 and is the brightest known at such a large distance and such an early time. This is due to a lucky circumstance: a massive cluster of galaxies ( MS 1512+36 ) is located about halfway along the line-of-sight, at a distance of about 7 billion light-years, and acts as a gravitational "magnifying glass". Thanks to this lensing effect, the image of MS1512-cB58 appears 50 times brighter . Nevertheless, the apparent brightness is still as faint as magnitude 20.6 (i.e., nearly 1 million times fainter than what can be perceived with the unaided eye). Moreover, MS 1512-cB58 is located 36° north of the celestial equator and never rises more than 29° above the horizon at Paranal. It was therefore a great challenge to secure the present observational data with the UVES high-dispersion spectrograph on the 8.2-m VLT KUEYEN telescope . The extremely detailed UVES-spectrum of MS 1512-cB58 displays numerous signatures (absorption lines) of intergalactic gas clouds along the line-of-sight . Some of the clouds are quite close to the galaxy and the astronomers have therefore been able to investigate the distribution of matter in its immediate surroundings. They found an excess of material near MS 1512-cB58, possible evidence of a young supercluster of galaxies , already at this very early epoch. The new observations thus provide an invaluable contribution to current studies of the birth and evolution of structures in the early Universe. This is the first time this kind of observation has ever been done of a galaxy at such a large distance . All

  3. Drugs for treatment of very high blood pressure during pregnancy.

    Science.gov (United States)

    Duley, Lelia; Meher, Shireen; Jones, Leanne

    2013-07-31

    Very high blood pressure during pregnancy poses a serious threat to women and their babies. The aim of antihypertensive therapy is to lower blood pressure quickly but safety, to avoid complications. Antihypertensive drugs lower blood pressure but their comparative effectiveness and safety, and impact on other substantive outcomes is uncertain. To compare different antihypertensive drugs for very high blood pressure during pregnancy. We searched the Cochrane Pregnancy and Childbirth Group Trials Register (9 January 2013). Studies were randomised trials. Participants were women with severe hypertension during pregnancy. Interventions were comparisons of one antihypertensive drug with another. Two review authors independently assessed trials for inclusion and assessed trial quality. Two review authors extracted data and checked them for accuracy. Thirty-five trials (3573 women) with 15 comparisons were included. Women allocated calcium channel blockers were less likely to have persistent high blood pressure compared to those allocated hydralazine (six trials, 313 women; 8% versus 22%; risk ratio (RR) 0.37, 95% confidence interval (CI) 0.21 to 0.66). Ketanserin was associated with more persistent high blood pressure than hydralazine (three trials, 180 women; 27% versus 6%; RR 4.79, 95% CI 1.95 to 11.73), but fewer side-effects (three trials, 120 women; RR 0.32, 95% CI 0.19 to 0.53) and a lower risk of HELLP (haemolysis, elevated liver enzymes and lowered platelets) syndrome (one trial, 44 women; RR 0.20, 95% CI 0.05 to 0.81).Labetalol was associated with a lower risk of hypotension compared to diazoxide (one trial 90 women; RR 0.06, 95% CI 0.00 to 0.99) and a lower risk of caesarean section (RR 0.43, 95% CI 0.18 to 1.02), although both were borderline for statistical significance.Both nimodipine and magnesium sulphate were associated with a high incidence of persistent high blood pressure, but this risk was lower for nimodipine compared to magnesium sulphate (one trial

  4. Relevance of axionlike particles for very-high-energy astrophysics

    International Nuclear Information System (INIS)

    De Angelis, Alessandro; Galanti, Giorgio; Roncadelli, Marco

    2011-01-01

    Several extensions of the standard model and, in particular, superstring theories suggest the existence of axionlike particles (ALPs), which are very light spin-zero bosons with a two-photon coupling. As a consequence, photon-ALP oscillations occur in the presence of an external magnetic field, and ALPs can lead to observable effects on the measured photon spectrum of astrophysical sources. An intriguing situation arises when blazars are observed in the very-high-energy (VHE) band--namely, above 100 GeV--as it is the case with the presently operating Imaging Atmospheric Cherenkov Telescopes H.E.S.S, Major Atmospheric Gamma Imaging Cherenkov telescope, Collaboration of Australia and Nippon for a Gamma Ray Observatory in the Outback III, and VERITAS. The extragalactic background light produced by galaxies during cosmic evolution gives rise to a source dimming which becomes important in the VHE band and increases with energy, since hard photons from a blazar scatter off soft extragalactic background light photons thereby disappearing into e + e - pairs. This dimming can be considerably reduced by photon-ALP oscillations, and since they are energy independent the resulting blazar spectra become harder than expected. We consider throughout a scenario first proposed by De Angelis, Roncadelli, and Mansutti in which the above strategy is implemented with photon-ALP oscillations triggered by large-scale magnetic fields, and we systematically investigate its implications for VHE blazars. We find that for ALPs lighter than 5·10 -10 eV the photon survival probability is larger than predicted by conventional physics above a few hundred GeV. Specifically, a boost factor of 10 can easily occur for sources at large distance and large energy, e.g. at 8 TeV for the blazar 1ES 0347-121 at redshift z=0.188. This is a clear-cut prediction which can be tested with the planned Cherenkov Telescope Array and the High Altitude Water Cherenkov Experiment (HAWC) water Cherenkov

  5. Borehole strain observations of very low frequency earthquakes

    Science.gov (United States)

    Hawthorne, J. C.; Ghosh, A.; Hutchinson, A. A.

    2016-12-01

    We examine the signals of very low frequency earthquakes (VLFEs) in PBO borehole strain data in central Cascadia. These MW 3.3 - 4.1 earthquakes are best observed in seismograms at periods of 20 to 50 seconds. We look for the strain they produce on timescales from about 1 to 30 minutes. First, we stack the strain produced by 13 VLFEs identified by a grid search moment tensor inversion algorithm by Ghosh et. al. (2015) and Hutchinson and Ghosh (2016), as well as several thousand VLFEs detected through template matching these events. The VLFEs are located beneath southernmost Vancouver Island and the eastern Olympic Peninsula, and are best recorded at co-located stations B005 and B007. However, even at these stations, the signal to noise in the stack is often low, and the records are difficult to interpret. Therefore we also combine data from multiple stations and VLFE locations, and simply look for increases in the strain rate at the VLFE times, as increases in strain rate would suggest an increase in the moment rate. We compare the background strain rate in the 12 hours centered on the VLFEs with the strain rate in the 10 minutes centered on the VLFEs. The 10-minute duration is chosen as a compromise that averages out some instrumental noise without introducing too much longer-period random walk noise. Our results suggest a factor of 2 increase in strain rate--and thus moment rate--during the 10-minute VLFE intervals. The increase gives an average VLFE magnitude around M 3.5, within the range of magnitudes obtained with seismology. Further analyses are currently being carried out to better understand the evolution of moment release before, during, and after the VLFEs.

  6. How Very Massive Metal-Free Stars Start Cosmological Reionization

    Science.gov (United States)

    Wise, John H.; Abel, Tom

    2008-01-01

    The initial conditions and relevant physics for the formation of the earliest galaxies are well specified in the concordance cosmology. Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include nonequilibrium primordial gas chemistry and cooling processes and accurate radiation transport in the case B approximation using adaptively ray-traced photon packages, retaining the time derivative in the transport equation. Supernova feedback is modeled by thermal explosions triggered at parsec scales. All calculations resolve the local Jeans length by at least 16 grid cells at all times and as such cover a spatial dynamic range of approx.10(exp 6). These first sources of reionization are highly intermittent and anisotropic and first photoionize the small-scale voids surrounding the halos they form in, rather than the dense filaments they are embedded in. As the merging objects form larger, dwarf-sized galaxies, the escape fraction of UV radiation decreases and the H II regions only break out on some sides of the galaxies, making them even more anisotropic. In three cases, SN blast waves induce star formation in overdense regions that were formed earlier from ionization front instabilities. These stars form tens of parsecs away from the center of their parent DM halo. Approximately five ionizing photons are needed per sustained ionization when star formation in 10(exp 6) stellar Mass halos is dominant in the calculation. As the halos become larger than approx.10(exp 7) Stellar Mass, the ionizing photon escape fraction decreases, which in turn increases the number of photons per ionization to 15-50, in calculations with stellar feedback only. Radiative feedback decreases clumping factors by 25% when compared to simulations without star formation and increases the average temperature of ionized gas to values between 3000 and 10,000 K.

  7. Very Large Array Multiband Monitoring Observations of M31*

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Li, Zhiyuan [School of Astronomy and Space Science, Nanjing University, Nanjing 210023 (China); Sjouwerman, Loránt O. [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Yuan, Feng; Shen, Zhi-Qiang, E-mail: lizy@nju.edu.cn [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China)

    2017-08-20

    The Andromeda galaxy (M31) hosts one of the nearest and most quiescent supermassive black holes, which provides a rare, but promising opportunity for studying the physics of black hole accretion at the lowest state. We have conducted a multifrequency, multi-epoch observing campaign, using the Karl G. Jansky Very Large Array (VLA) in its extended configurations in 2011–2012, to advance our knowledge of the still poorly known radio properties of M31*. For the first time, we detect M31* at 10, 15, and 20 GHz and measure its spectral index, α ≈ −0.45 ± 0.08 (S{sub ν} ∝ ν {sup α}), over the frequency range of 5–20 GHz. The relatively steep spectrum suggests that the observed radio flux is dominated by the optically thin part of a putative jet, which is located at no more than a few thousand Schwarzschild radii from the black hole. On the other hand, our sensitive radio images show little evidence for an extended component, perhaps except for several parsec-scale “plumes,” the nature of which remains unclear. Our data also reveal significant (a few tens of percent) flux variation of M31* at 6 GHz, on timescales of hours to days. Furthermore, a curious decrease of the mean flux density, by ∼50%, is found between VLA observations taken during 2002–2005 and our new observations, which might be associated with a substantial increase in the mean X-ray flux of M31* starting in 2006.

  8. Auditory Sketches: Very Sparse Representations of Sounds Are Still Recognizable.

    Directory of Open Access Journals (Sweden)

    Vincent Isnard

    Full Text Available Sounds in our environment like voices, animal calls or musical instruments are easily recognized by human listeners. Understanding the key features underlying this robust sound recognition is an important question in auditory science. Here, we studied the recognition by human listeners of new classes of sounds: acoustic and auditory sketches, sounds that are severely impoverished but still recognizable. Starting from a time-frequency representation, a sketch is obtained by keeping only sparse elements of the original signal, here, by means of a simple peak-picking algorithm. Two time-frequency representations were compared: a biologically grounded one, the auditory spectrogram, which simulates peripheral auditory filtering, and a simple acoustic spectrogram, based on a Fourier transform. Three degrees of sparsity were also investigated. Listeners were asked to recognize the category to which a sketch sound belongs: singing voices, bird calls, musical instruments, and vehicle engine noises. Results showed that, with the exception of voice sounds, very sparse representations of sounds (10 features, or energy peaks, per second could be recognized above chance. No clear differences could be observed between the acoustic and the auditory sketches. For the voice sounds, however, a completely different pattern of results emerged, with at-chance or even below-chance recognition performances, suggesting that the important features of the voice, whatever they are, were removed by the sketch process. Overall, these perceptual results were well correlated with a model of auditory distances, based on spectro-temporal excitation patterns (STEPs. This study confirms the potential of these new classes of sounds, acoustic and auditory sketches, to study sound recognition.

  9. Very large eddy simulation of the Red Sea overflow

    Science.gov (United States)

    Ilıcak, Mehmet; Özgökmen, Tamay M.; Peters, Hartmut; Baumert, Helmut Z.; Iskandarani, Mohamed

    Mixing between overflows and ambient water masses is a critical problem of deep-water mass formation in the downwelling branch of the meridional overturning circulation of the ocean. Modeling approaches that have been tested so far rely either on algebraic parameterizations in hydrostatic ocean circulation models, or on large eddy simulations that resolve most of the mixing using nonhydrostatic models. In this study, we examine the performance of a set of turbulence closures, that have not been tested in comparison to observational data for overflows before. We employ the so-called very large eddy simulation (VLES) technique, which allows the use of k-ɛ models in nonhydrostatic models. This is done by applying a dynamic spatial filtering to the k-ɛ equations. To our knowledge, this is the first time that the VLES approach is adopted for an ocean modeling problem. The performance of k-ɛ and VLES models are evaluated by conducting numerical simulations of the Red Sea overflow and comparing them to observations from the Red Sea Outflow Experiment (REDSOX). The computations are constrained to one of the main channels transporting the overflow, which is narrow enough to permit the use of a two-dimensional (and nonhydrostatic) model. A large set of experiments are conducted using different closure models, Reynolds numbers and spatial resolutions. It is found that, when no turbulence closure is used, the basic structure of the overflow, consisting of a well-mixed bottom layer (BL) and entraining interfacial layer (IL), cannot be reproduced. The k-ɛ model leads to unrealistic thicknesses for both BL and IL, while VLES results in the most realistic reproduction of the REDSOX observations.

  10. Evolution of massive stars in very young clusters and associations

    International Nuclear Information System (INIS)

    Stothers, R.B.

    1985-01-01

    The stellar content of very young galactic clusters and associations with well-determined ages has been analyzed statistically to derive information about stellar evolution at high masses. The adopted approach is semiempirical and uses natural spectroscopic groups of stars on the H-R diagram, together with the stars' apparent magnitudes. Cluster distance moduli are not used. Only the most basic elements of stellar evolution theory are required as input. For stellar aggregates with main-sequence turnups at spectral types between O9 and B2, the following conclusions have emerged: (1) O-type main-sequence stars evolve to a spectral type of B1 during core hydrogen burning; (2) most of the O-type blue stragglers are newly formed massive stars, burning core hydrogen; (3) supergiants lying redward of the turnup, as well as most, or all, of the Wolf-Rayet stars, are burning core helium; (4) Wolf-Rayet stars originally had masses greater than 30--40 M/sub sun/, while known M-type supergiants evolved from star less massive than approx.30 M/sub sun/; (5) phases of evolution following core helium burning are unobservably rapid, presumably on account of copious neutrino emission; and (6) formation of stars of high mass continues vigorously in most young clusters and association for approx.8 x 10 6 yr. The important result concerning the evolutionary status of the supergiants depends only on the total number of these stars and not on how they are distributed between blue and red types; the result, however, may be sensitive to the assumed amount of convective core overshooting. Conclusions in the present work refer chiefly to luminous stars in the mass range 10--40 M/sub sun/, belonging to aggregates in the age range (6--25) x 10 6 yr

  11. Pumped storage in systems with very high wind penetration

    International Nuclear Information System (INIS)

    Tuohy, A.; O'Malley, M.

    2011-01-01

    This paper examines the operation of the Irish power system with very high levels of wind energy, with and without pumped storage. A unit commitment model which accounts for the uncertainty in wind power is used. It is shown that as wind penetration increases, the optimal operation of storage depends on wind output as well as load. The main benefit from storage is shown to be a decrease in wind curtailment. The economics of the system are examined to find the level at which storage justifies its capital costs and inefficiencies. It is shown that the uncertainty of wind makes the option of storage more attractive. The size of the energy store has an impact on results. At lower levels of installed wind (up to approximately 50% of energy from wind in Ireland), the reduction in curtailment is insufficient to justify building storage. At greater levels of wind, storage reduces curtailment sufficiently to justify the additional capital costs. It can be seen that if storage replaces OCGTs in the plant mix instead of CCGTs, then the level at which it justifies itself is lower. Storage increases the level of carbon emissions at wind penetration below 60%. - Research highlights: → Examines operation of pumped storage unit in a system with levels of wind from 34%-68% of energy. → High capital cost of storage is not justified until system has high (approx. 45%) wind penetration. → Results are driven by the amount of wind curtailment avoided and plant mix of system. → Other flexible options (e.g. interconnection) offer many of the same benefits as storage.

  12. Mathematics ability and related skills in preschoolers born very preterm.

    Science.gov (United States)

    Hasler, Holly M; Akshoomoff, Natacha

    2017-12-12

    Children born very preterm (VPT) are at risk for academic, behavioral, and/or emotional problems. Mathematics is a particular weakness and better understanding of the relationship between preterm birth and early mathematics ability is needed, particularly as early as possible to aid in early intervention. Preschoolers born VPT (n = 58) and those born full term (FT; n = 29) were administered a large battery of measures within 6 months of beginning kindergarten. A multiple-mediation model was utilized to characterize the difference in skills underlying mathematics ability between groups. Children born VPT performed significantly worse than FT-born children on a measure of mathematics ability as well as full-scale IQ, verbal skills, visual-motor integration, phonological awareness, phonological working memory, motor skills, and executive functioning. Mathematics was significantly correlated with verbal skills, visual-motor integration, phonological processing, and motor skills across both groups. When entered into the mediation model, verbal skills, visual-motor integration, and phonological awareness were significant mediators of the group differences. This analysis provides insights into the pre-academic skills that are weak in preschoolers born VPT and their relationship to mathematics. It is important to identify children who will have difficulties as early as possible, particularly for VPT children who are at higher risk for academic difficulties. Therefore, this model may be used in evaluating VPT children for emerging difficulties as well as an indicator that if other weaknesses are found, an assessment of mathematics should be conducted.

  13. Rare and very rare adverse effects of clozapine

    Directory of Open Access Journals (Sweden)

    De Fazio P

    2015-08-01

    Full Text Available Pasquale De Fazio,1 Raffaele Gaetano,1 Mariarita Caroleo,1 Gregorio Cerminara,1 Francesca Maida,2 Antonio Bruno,3 Maria Rosaria Muscatello,3 Maria Jose Jaén Moreno,4 Emilio Russo,2 Cristina Segura-García1 1Department of Health Sciences, School of Specialization in Psychiatry, 2Department of Health Sciences, School of Specialization in Pharmacology, University “Magna Graecia”, Catanzaro, 3Department of Neurosciences, School of Specialization in Psychiatry, University of Messina, Messina, Italy; 4Department of Social Health Sciences, Radiology and Physical Medicine, University of Cordoba, Cordoba, Spain Abstract: Clozapine (CLZ is the drug of choice for the treatment of resistant schizophrenia; however, its suitable use is limited by the complex adverse effects’ profile. The best-described adverse effects in the literature are represented by agranulocytosis, myocarditis, sedation, weight gain, hypotension, and drooling; nevertheless, there are other known adverse effects that psychiatrists should readily recognize and manage. This review covers the “rare” and “very rare” known adverse effects of CLZ, which have been accurately described in literature. An extensive search on the basis of predefined criteria was made using CLZ and its combination with adverse effects as keywords in electronic databases. Data show the association between the use of CLZ and uncommon adverse effects, including ischemic colitis, paralytic ileus, hematemesis, gastroesophageal reflux disease, priapism, urinary incontinence, pityriasis rosea, intertriginous erythema, pulmonary thromboembolism, pseudo-pheochromocytoma, periorbital edema, and parotitis, which are influenced by other variables including age, early diagnosis, and previous/current pharmacological therapies. Some of these adverse effects, although unpredictable, are often manageable if promptly recognized and treated. Others are serious and potentially life-threatening. However, an adequate

  14. Steady-state emission of blazars at very high energies

    International Nuclear Information System (INIS)

    Hoehne-Moench, Daniel

    2010-01-01

    One key scientific program of the MAGIC telescope project is the discovery and detection of blazars. They constitute the most prominent extragalactic source class in the very high energy (VHE) γ-ray regime with 29 out of 34 known objects. Therefore a major part of the available observation time was spent in the last years on high-frequency peaked blazars. The selection criteria were chosen to increase the detection probability. As the X-ray flux is believed to be correlated to the VHE γ-ray flux, only X-ray selected sources with a flux F X >2 μJy at 1 keV were considered. To avoid strong attenuation of the -rays in the extragalactic infrared background, the redshift was restricted to values between z X-γ between the X-ray range at 1 keV and the VHE γ-ray regime at 200 GeV were calculated. The majority of objects show a spectral behaviour as expected from the source class of HBLs: The energy output in the VHE regime is in general lower than in X-rays. For the stacked blazar sample the broad-band spectral index was calculated to α X-γ =1.09, confirming the result found for the individual objects. Another evidence for the revelation of the baseline emission is the broad-band spectral energy distribution (SED) comprising archival as well as contemporaneous multi-wavelength data from the radio to the VHE band. The SEDs of known VHE γ-ray sources in low flux states matches well the SED of the stacked blazar sample. (orig.)

  15. Very Large Array Multiband Monitoring Observations of M31*

    International Nuclear Information System (INIS)

    Yang, Yang; Li, Zhiyuan; Sjouwerman, Loránt O.; Yuan, Feng; Shen, Zhi-Qiang

    2017-01-01

    The Andromeda galaxy (M31) hosts one of the nearest and most quiescent supermassive black holes, which provides a rare, but promising opportunity for studying the physics of black hole accretion at the lowest state. We have conducted a multifrequency, multi-epoch observing campaign, using the Karl G. Jansky Very Large Array (VLA) in its extended configurations in 2011–2012, to advance our knowledge of the still poorly known radio properties of M31*. For the first time, we detect M31* at 10, 15, and 20 GHz and measure its spectral index, α ≈ −0.45 ± 0.08 (S ν ∝ ν α ), over the frequency range of 5–20 GHz. The relatively steep spectrum suggests that the observed radio flux is dominated by the optically thin part of a putative jet, which is located at no more than a few thousand Schwarzschild radii from the black hole. On the other hand, our sensitive radio images show little evidence for an extended component, perhaps except for several parsec-scale “plumes,” the nature of which remains unclear. Our data also reveal significant (a few tens of percent) flux variation of M31* at 6 GHz, on timescales of hours to days. Furthermore, a curious decrease of the mean flux density, by ∼50%, is found between VLA observations taken during 2002–2005 and our new observations, which might be associated with a substantial increase in the mean X-ray flux of M31* starting in 2006.

  16. Very Large Array Multiband Monitoring Observations of M31*

    Science.gov (United States)

    Yang, Yang; Li, Zhiyuan; Sjouwerman, Loránt O.; Yuan, Feng; Shen, Zhi-Qiang

    2017-08-01

    The Andromeda galaxy (M31) hosts one of the nearest and most quiescent supermassive black holes, which provides a rare, but promising opportunity for studying the physics of black hole accretion at the lowest state. We have conducted a multifrequency, multi-epoch observing campaign, using the Karl G. Jansky Very Large Array (VLA) in its extended configurations in 2011-2012, to advance our knowledge of the still poorly known radio properties of M31*. For the first time, we detect M31* at 10, 15, and 20 GHz and measure its spectral index, α ≈ -0.45 ± 0.08 (S ν ∝ ν α ), over the frequency range of 5-20 GHz. The relatively steep spectrum suggests that the observed radio flux is dominated by the optically thin part of a putative jet, which is located at no more than a few thousand Schwarzschild radii from the black hole. On the other hand, our sensitive radio images show little evidence for an extended component, perhaps except for several parsec-scale “plumes,” the nature of which remains unclear. Our data also reveal significant (a few tens of percent) flux variation of M31* at 6 GHz, on timescales of hours to days. Furthermore, a curious decrease of the mean flux density, by ˜50%, is found between VLA observations taken during 2002-2005 and our new observations, which might be associated with a substantial increase in the mean X-ray flux of M31* starting in 2006.

  17. Genetic variation of cowslip (Primula veris L. populations (West Poland

    Directory of Open Access Journals (Sweden)

    Maria Morozowska

    2011-01-01

    Full Text Available Genetic variation of twelve Polish populations of Primula veris L. from western Poland was investigated in respect of six enzyme systems: 6-phosphogluconate dehydrogenase (6PGD, diaphorase (DIA, menadione reductase (MNR, formate dehydrogenase (FDH, isocitrate dehydrogenase (IDH and glutamate oxaloacetate transaminase (GOT. Only two of them (6PGD and DIA were polymorphic and all populations were compared according to four loci and eight alleles. For 6PGD only one out of the two detected loci (locus 6PGD-2 was polymorphic and consisted of three alleles a, b and c. For DIA each of two detected loci had two alleles. For 6PGD-2 one population was monomorphic and four populations were monomorphic for DIA-1 and DIA-2. The rest of the populations were polymorphic with low frequency of heterozygotes. The low heterozygosity level, found in the examined populations, was confirmed by high values of the fixation index (F. The level of genetic differentiation among GST populations specified for each polymorphic loci, was equal to 0.045 for 6PGD-2 and had the value of 0.078 for DIA-2 and 0.186 for DIA-1. Nm value for polymorphic loci was 1.10 for DIA-1 and 2.94 for DIA-2, and for 6PGD-2 was 5.33, what indicates some gene flow between the examined populations. The dendrogram constructed on the basis of genotype frequencies showed that the populations were divided into two groups, however the most southern population No. 2 was clearly similar to the northern population No. 8.

  18. A novel type of very long baseline astronomical intensity interferometer

    Science.gov (United States)

    Borra, Ermanno F.

    2013-12-01

    This article presents a novel type of very long baseline astronomical interferometer that uses the fluctuations, as a function of time, of the intensity measured by a quadratic detector, which is a common type of astronomical detector. The theory on which the technique is based is validated by laboratory experiments. Its outstanding principal advantages comes from the fact that the angular structure of an astronomical object is simply determined from the visibility of the minima of the spectrum of the intensity fluctuations measured by the detector, as a function of the frequency of the fluctuations, while keeping the spacing between mirrors constant. This would allow a simple setup capable of high angular resolutions because it could use an extremely large baseline. Another major interest is that it allows for a more efficient use of telescope time because observations at a single baseline are sufficient, while amplitude and intensity interferometers need several observations at different baselines. The fact that one does not have to move the telescopes would also allow detecting faster time variations because having to move the telescopes sets a lower limit to the time variations that can be detected. The technique uses wave interaction effects and thus has some characteristics in common with intensity interferometry. A disadvantage of the technique, like in intensity interferometry, is that it needs strong sources if observing at high frequencies (e.g. the visible). This is a minor disadvantage in the radio region. At high frequencies, this disadvantage is mitigated by the fact that, like in intensity interferometry, the requirements of the optical quality of the mirrors used are far less severe than in amplitude interferometry so that poor quality large reflectors (e.g. Cherenkov telescopes) can be used in the optical region.

  19. Exotic phenomena in collisions of very heavy ions

    International Nuclear Information System (INIS)

    Soff, G.; Mueller, U.; Schramm, S.; de Reus, T.; Mehler, G.; Reinhardt, J.; Mueller, B.; Greiner, W.

    1987-01-01

    Over the last decade their knowledge on atomic structure of superheavy quasimolecules in the range 110 ≤ Z/sub tot/ ≤ 188 has increased considerably. Heavy ion collisions, in which superheavy quasimolecules are formed for a short period of time, offer them a unique tool to investigate the electronic structure of ultra-high Z-systems, which are not otherwise accessible to experiment. Comparison of K-vacancy formation, δ-electron and positron emission with available experimental data suggests the validity of the quasimolecular picture, which will be taken as the theoretical framework of these calculations. To exemplify current theoretical investigations three different topics will be discussed. After a presentation of the underlying theoretical framework for ionization processes the possibility to employ δ-electron emission as a clock to measure nuclear reaction times in intermediate energy collisions of very heavy ions will be sketched. Besides the phenomenon of vacuum decay into a new twofold negatively charged stable vacuum ground state, electron excitation in heavy ion collisions may be employed for the determination of delay and deceleration times on the nuclear time scale, i.e. offering an atomic clock, operating in the range 10 -21 - 10 -24 s. In deep-inelastic heavy ion collisions this provides a test for classical nuclear reaction models. In collisions at intermediate energies an independent measurement of the deceleration time is of interest for comparison, e.g., with the results of the pion bremsstrahlung model. After that the influence of one or more pockets in the ion scattering potential on the energy distribution of emitted positrons within a quantum mechanical framework is investigated. Finally phenomenological corrections to the Dirac equation and its consequences on electron binding energies in heavy and superheavy atoms is briefly considered. 42 references, 5 figures

  20. Finding very small near-Earth asteroids using synthetic tracking

    International Nuclear Information System (INIS)

    Shao, Michael; Nemati, Bijan; Zhai, Chengxing; Turyshev, Slava G.; Sandhu, Jagmit; Hallinan, Gregg; Harding, Leon K.

    2014-01-01

    We present an approach that significantly increases the sensitivity for finding and tracking small and fast near-Earth asteroids (NEAs). This approach relies on a combined use of a new generation of high-speed cameras which allow short, high frame-rate exposures of moving objects, effectively 'freezing' their motion, and a computationally enhanced implementation of the 'shift-and-add' data processing technique that helps to improve the signal-to-noise ratio (SNR) for detection of NEAs. The SNR of a single short exposure of a dim NEA is insufficient to detect it in one frame, but by computationally searching for an appropriate velocity vector, shifting successive frames relative to each other and then co-adding the shifted frames in post-processing, we synthetically create a long-exposure image as if the telescope were tracking the object. This approach, which we call 'synthetic tracking,' enhances the familiar shift-and-add technique with the ability to do a wide blind search, detect, and track dim and fast-moving NEAs in near real time. We discuss also how synthetic tracking improves the astrometry of fast-moving NEAs. We apply this technique to observations of two known asteroids conducted on the Palomar 200 inch telescope and demonstrate improved SNR and 10 fold improvement of astrometric precision over the traditional long-exposure approach. In the past 5 yr, about 150 NEAs with absolute magnitudes H = 28 (∼10 m in size) or fainter have been discovered. With an upgraded version of our camera and a field of view of (28 arcmin) 2 on the Palomar 200 inch telescope, synthetic tracking could allow detecting up to 180 such objects per night, including very small NEAs with sizes down to 7 m.

  1. Finding very small near-Earth asteroids using synthetic tracking

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Michael; Nemati, Bijan; Zhai, Chengxing; Turyshev, Slava G.; Sandhu, Jagmit [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-0899 (United States); Hallinan, Gregg; Harding, Leon K. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

    2014-02-10

    We present an approach that significantly increases the sensitivity for finding and tracking small and fast near-Earth asteroids (NEAs). This approach relies on a combined use of a new generation of high-speed cameras which allow short, high frame-rate exposures of moving objects, effectively 'freezing' their motion, and a computationally enhanced implementation of the 'shift-and-add' data processing technique that helps to improve the signal-to-noise ratio (SNR) for detection of NEAs. The SNR of a single short exposure of a dim NEA is insufficient to detect it in one frame, but by computationally searching for an appropriate velocity vector, shifting successive frames relative to each other and then co-adding the shifted frames in post-processing, we synthetically create a long-exposure image as if the telescope were tracking the object. This approach, which we call 'synthetic tracking,' enhances the familiar shift-and-add technique with the ability to do a wide blind search, detect, and track dim and fast-moving NEAs in near real time. We discuss also how synthetic tracking improves the astrometry of fast-moving NEAs. We apply this technique to observations of two known asteroids conducted on the Palomar 200 inch telescope and demonstrate improved SNR and 10 fold improvement of astrometric precision over the traditional long-exposure approach. In the past 5 yr, about 150 NEAs with absolute magnitudes H = 28 (∼10 m in size) or fainter have been discovered. With an upgraded version of our camera and a field of view of (28 arcmin){sup 2} on the Palomar 200 inch telescope, synthetic tracking could allow detecting up to 180 such objects per night, including very small NEAs with sizes down to 7 m.

  2. VETEM -- a very early time electromagnetic system -- year 2

    International Nuclear Information System (INIS)

    Pellerin, L.; Pfeifer, M.C.; Labson, V.F.

    1996-01-01

    In electrically conductive conditions common in environmental characterization studies the minimum depth of investigation for traditional electromagnetic (EM) sounding techniques is roughly 5 meters, while ground penetrating radar (GPR) systems often investigate no more than the top meter or so when clay minerals are present in the soil. Bridging this gap is essential to the characterization of buried waste, contaminant plumes, and other environmental and hydrogeological targets located in the shallow subsurface. The Very Early Time Electromagnetic (VETEM) system is designed to ascertain the conductivity and dielectric properties of the shallow subsurface in conductive terrain. Hence, the one-dimensional (1-D) and three-dimensional (3-D) numerical modeling algorithms, developed in the first year of the project, contain the full solution to the EM problem including both displacement and conduction currents. The VETEM system fills a gap between EM and GPR, but all three methods are necessary to successfully image the shallow subsurface. To achieve the goal of fully 3-D subsurface imaging, the VETEM project is hosting the Electromagnetic Integrated Demonstration (EMID) at the Idaho National Engineering Laboratory's Cold Test Pit (INEL's CTP). Over a dozen EM systems will acquire data over the same survey area for interpretation in conjunction with the VETEM team. The prototype time-domain instrument employs a magnetic dipole transmitter and receiver and operates from 10 nano-second to a micro-second. The USGS high frequency sounder (HFS), which served as the VETEM proof-of-concept, uses the same antenna geometry as the time-domain instrument and acquires data from 30 kHz to 30 MHz. The first VETEM survey was recently conducted at the INEL's CTP as a part of the EMID. The electromagnetic migration technique is being investigated for interpretation of the VETEM data

  3. RECOVERY FROM GIANT ERUPTIONS IN VERY MASSIVE STARS

    International Nuclear Information System (INIS)

    Kashi, Amit; Davidson, Kris; Humphreys, Roberta M.

    2016-01-01

    We use a hydro-and-radiative-transfer code to explore the behavior of a very massive star (VMS) after a giant eruption—i.e., following a supernova impostor event. Beginning with reasonable models for evolved VMSs with masses of 80 M ⊙ and 120 M ⊙ , we simulate the change of state caused by a giant eruption via two methods that explicitly conserve total energy. (1) Synthetically removing outer layers of mass of a few M ⊙ while reducing the energy of the inner layers. (2) Synthetically transferring energy from the core to the outer layers, an operation that automatically causes mass ejection. Our focus is on the aftermath, not the poorly understood eruption itself. Then, using a radiation-hydrodynamic code in 1D with realistic opacities and convection, the interior disequilibrium state is followed for about 200 years. Typically the star develops a ∼400 km s −1 wind with a mass loss rate that begins around 0.1 M ⊙  yr −1 and gradually decreases. This outflow is driven by κ-mechanism radial pulsations. The 1D models have regular pulsations but 3D models will probably be more chaotic. In some cases a plateau in the mass-loss rate may persist about 200 years, while other cases are more like η Car which lost >10 M ⊙ and then had an abnormal mass loss rate for more than a century after its eruption. In our model, the post-eruption outflow carried more mass than the initial eruption. These simulations constitute a useful preliminary reconnaissance for 3D models which will be far more difficult

  4. Speckle photography applied to measure deformations of very large structures

    Science.gov (United States)

    Conley, Edgar; Morgan, Chris K.

    1995-04-01

    Fundamental principles of mechanics have recently been brought to bear on problems concerning very large structures. Fields of study include tectonic plate motion, nuclear waste repository vault closure mechanisms, the flow of glacier and sea ice, and highway bridge damage assessment and residual life prediction. Quantitative observations, appropriate for formulating and verifying models, are still scarce however, so the need to adapt new methods of experimental mechanics is clear. Large dynamic systems often exist in environments subject to rapid change. Therefore, a simple field technique that incorporates short time scales and short gage lengths is required. Further, the measuring methods must yield displacements reliably, and under oft-times adverse field conditions. Fortunately, the advantages conferred by an experimental mechanics technique known as speckle photography nicely fulfill this rather stringent set of performance requirements. Speckle seemed to lend itself nicely to the application since it is robust and relatively inexpensive. Experiment requirements are minimal -- a camera, high resolution film, illumination, and an optically rough surface. Perhaps most important is speckle's distinct advantage over point-by-point methods: It maps the two dimensional displacement vectors of the whole field of interest. And finally, given the method's high spatial resolution, relatively short observation times are necessary. In this paper we discuss speckle, two variations of which were used to gage the deformation of a reinforced concrete bridge structure subjected to bending loads. The measurement technique proved to be easily applied, and yielded the location of the neutral axis self consistently. The research demonstrates the feasibility of using whole field techniques to detect and quantify surface strains of large structures under load.

  5. Heavy residues from very mass asymmetric heavy ion reactions

    International Nuclear Information System (INIS)

    Hanold, K.A.

    1994-08-01

    The isotopic production cross sections and momenta of all residues with nuclear charge (Z) greater than 39 from the reaction of 26, 40, and 50 MeV/nucleon 129 Xe + Be, C, and Al were measured. The isotopic cross sections, the momentum distribution for each isotope, and the cross section as a function of nuclear charge and momentum are presented here. The new cross sections are consistent with previous measurements of the cross sections from similar reaction systems. The shape of the cross section distribution, when considered as a function of Z and velocity, was found to be qualitatively consistent with that expected from an incomplete fusion reaction mechanism. An incomplete fusion model coupled to a statistical decay model is able to reproduce many features of these reactions: the shapes of the elemental cross section distributions, the emission velocity distributions for the intermediate mass fragments, and the Z versus velocity distributions. This model gives a less satisfactory prediction of the momentum distribution for each isotope. A very different model based on the Boltzman-Nordheim-Vlasov equation and which was also coupled to a statistical decay model reproduces many features of these reactions: the shapes of the elemental cross section distributions, the intermediate mass fragment emission velocity distributions, and the Z versus momentum distributions. Both model calculations over-estimate the average mass for each element by two mass units and underestimate the isotopic and isobaric widths of the experimental distributions. It is shown that the predicted average mass for each element can be brought into agreement with the data by small, but systematic, variation of the particle emission barriers used in the statistical model. The predicted isotopic and isobaric widths of the cross section distributions can not be brought into agreement with the experimental data using reasonable parameters for the statistical model

  6. Evidence for Very Recent Positive Selection in Mongolians.

    Science.gov (United States)

    Nakayama, Kazuhiro; Ohashi, Jun; Watanabe, Kazuhisa; Munkhtulga, Lkagvasuren; Iwamoto, Sadahiko

    2017-08-01

    Mongols, the founders of the largest continental empire in history, successfully adapted to the harsh environments of Inner Asia through nomadic pastoralism. Considerable interest exists in ascertaining whether genetic adaptation also contributed to the Mongols' success, and dissecting the genome diversity of present-day populations in Mongolia can help address this question. To this end, we determined the genotypes of nearly 2.4 million single nucleotide polymorphisms (SNPs) of 96 unrelated Mongolian individuals in Ulaanbaatar city, and performed genome-wide scans for population-specific positive selection. We discovered signatures of Mongolian-specific positive selection at the chromosomal region 3p12.1, in which hits in genome-wide association studies were reported for medical and biological traits related to energy metabolism and reproduction. The top SNP, rs117799927, showed a distinctive geographic distribution: the frequency of the derived allele, rs117799927 G, was extremely low among worldwide populations (0.005) but exceptionally high in Mongolians (0.247). Approximate Bayesian computation-based age estimation showed that the rs117799927 G allele emerged or positive selection began to operate 50 generations before the present, near the age of the climate anomaly named Late Antique Little Ice Age. Furthermore, rs117799927 showed significant associations with multiple adiposity-related traits in Mongolians and allelic difference in enhancer activity in cells of adipocyte lineage, suggesting that positive selection at 3p12.1 might be related to adaptation in the energy metabolism system. These findings provide novel evidence for a very recent positive-selection event in Homo sapiens and offer insights into the roles of genes in 3p12.1 in the adaptive evolution of our species. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. RECOVERY FROM GIANT ERUPTIONS IN VERY MASSIVE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Kashi, Amit; Davidson, Kris; Humphreys, Roberta M., E-mail: kashi@astro.umn.edu [Minnesota Institute for Astrophysics, University of Minnesota, 116 Church St. SE. Minneapolis, MN 55455 (United States)

    2016-01-20

    We use a hydro-and-radiative-transfer code to explore the behavior of a very massive star (VMS) after a giant eruption—i.e., following a supernova impostor event. Beginning with reasonable models for evolved VMSs with masses of 80 M{sub ⊙} and 120 M{sub ⊙}, we simulate the change of state caused by a giant eruption via two methods that explicitly conserve total energy. (1) Synthetically removing outer layers of mass of a few M{sub ⊙} while reducing the energy of the inner layers. (2) Synthetically transferring energy from the core to the outer layers, an operation that automatically causes mass ejection. Our focus is on the aftermath, not the poorly understood eruption itself. Then, using a radiation-hydrodynamic code in 1D with realistic opacities and convection, the interior disequilibrium state is followed for about 200 years. Typically the star develops a ∼400 km s{sup −1} wind with a mass loss rate that begins around 0.1 M{sub ⊙} yr{sup −1} and gradually decreases. This outflow is driven by κ-mechanism radial pulsations. The 1D models have regular pulsations but 3D models will probably be more chaotic. In some cases a plateau in the mass-loss rate may persist about 200 years, while other cases are more like η Car which lost >10 M{sub ⊙} and then had an abnormal mass loss rate for more than a century after its eruption. In our model, the post-eruption outflow carried more mass than the initial eruption. These simulations constitute a useful preliminary reconnaissance for 3D models which will be far more difficult.

  8. A Very Neutral Voice: Teaching about the Holocaust

    Directory of Open Access Journals (Sweden)

    Jane Clements

    2006-05-01

    Full Text Available Contextualisation The Holocaust is a significant event in the history of twentieth century Europe and, as such, is an important topic for pupils to encounter in classroom lessons. Aside from the acquisition of skills helpful for historical enquiry and evaluation, some teachers and educationalists, as well as those outside the educational world, make claims for the topic in terms of its promoting anti-racism or Citizenship. However, this paper suggests that a particular learning experience is to be found in the dynamics of the relationship between teacher and pupil. Abstract: This paper is concerned to address the question of ‘What are The Lessons To Be Learnt in the study of the Holocaust?’ Very little research has been done in this field, although both the literature and classroom teachers tend to cite rationales from countering racism to promoting engagement with Citizenship issues. Research in related areas, together with the experience of the teachers themselves, indicates that such grand outcomes are unlikely. This paper suggests that the main outcome of Holocaust Education is the enabling of a re-examination of pupil discourses about humanity and society. The relationship between teacher and pupil in the course of these lessons, issues of shared language and a lowering of the barrier of emotional restraint all contribute to produce this outcome. This paper further suggests that, while the facts of the events themselves are important in terms of historical understanding, the main value of the lessons comes not from these but from an experience of empowerment as both teachers and pupils engage with the concept of ‘difficult knowledge’.

  9. Preparation of very small point sources for high resolution radiography

    International Nuclear Information System (INIS)

    Case, F.N.

    1976-01-01

    The need for very small point sources of high specific activity 192 Ir, 169 Yb, 170 Tm, and 60 Co in non-destructive testing has motivated the development of techniques for the fabrication of these sources. To prepare 192 Ir point sources for use in examination of tube sheet welds in LMFBR heat exchangers, 191 Ir enriched to greater than 90 percent was melted in a helium blanketed arc to form spheres as small as 0.38 mm in diameter. Methods were developed to form the roughly spherical shaped arc product into nearly symmetrical spheres that could be used for high resolution radiography. Similar methods were used for spherical shaped sources of 169 Yb and 170 Tm. The oxides were arc melted to form rough spheres followed by grinding to precise dimensions, neutron irradiation of the spheres at a flux of 2 to 3 x 10 15 nv, and use of enriched 168 Yb to provide the maximum specific activity. Cobalt-60 with a specific activity of greater than 1100 Ci/g was prepared by processing 59 Co that had been neutron irradiated to nearly complete burnup of the 59 Co target to produce 60 Co, 61 Ni, and 62 Ni. Ion exchange methods were used to separate the cobalt from the nickel. The cobalt was reduced to metal by plating either onto aluminum foil which was dissolved away from the cobalt plate, or by plating onto mercury to prepare amalgam that could be easily formed into a pellet of cobalt with exclusion of the mercury. Both methods are discussed

  10. How Very Massive Metal Free Stars Start Cosmological Reionization

    International Nuclear Information System (INIS)

    Wise, John H.; Abel, Tom

    2007-01-01

    The initial conditions and relevant physics for the formation of the earliest galaxies are well specified in the concordance cosmology. Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include non-equilibrium primordial gas chemistry and cooling processes and accurate radiation transport in the Case B approximation using adaptively ray traced photon packages, retaining the time derivative in the transport equation. Supernova feedback is modeled by thermal explosions triggered at parsec scales. All calculations resolve the local Jeans length by at least 16 grid cells at all times and as such cover a spatial dynamic range of ∼10 6 . These first sources of reionization are highly intermittent and anisotropic and first photoionize the small scales voids surrounding the halos they form in, rather than the dense filaments they are embedded in. As the merging objects form larger, dwarf sized galaxies, the escape fraction of UV radiation decreases and the H II regions only break out on some sides of the galaxies making them even more anisotropic. In three cases, SN blast waves induce star formation in overdense regions that were formed earlier from ionization front instabilities. These stars form tens of parsecs away from the center of their parent DM halo. Approximately 5 ionizing photons are needed per sustained ionization when star formation in 10 6 M · halos are dominant in the calculation. As the halos become larger than ∼10 7 M # circle d ot#, the ionizing photon escape fraction decreases, which in turn increases the number of photons per ionization to 15--50, in calculations with stellar feedback only. Supernova feedback in these more massive halos creates a more diffuse medium, allowing the stellar radiation to escape more easily and maintaining the ratio of 5 ionizing photons per sustained ionization

  11. Postdischarge growth assessment in very low birth weight infants.

    Science.gov (United States)

    Park, Joon-Sik; Han, Jungho; Shin, Jeong Eun; Lee, Soon Min; Eun, Ho Seon; Park, Min-Soo; Park, Kook-In; Namgung, Ran

    2017-03-01

    The goal of nutritional support for very-low-birth-weight (VLBW) infants from birth to term is to match the in utero growth rates; however, this is rarely achieved. We evaluated postdischarge growth patterns and growth failure in 81 Korean VLBW infants through a retrospective study. Weight and height were measured and calculated based on age percentile distribution every 3 months until age 24 months. Growth failure was defined as weight and height below the 10th percentile at 24 months. For the subgroup analysis, small-for-gestational age (SGA) and extremely low birth weight (ELBW) infants were evaluated. The growth patterns based on the Korean, World Health Organization (WHO), or Centers for Disease Control and Prevention (CDC) standard were serially compared over time. At postconception age (PCA) 40 weeks, 47 (58%) and 45 infants (55%) showed growth failure in terms of weight and height, respectively. At PCA 24 months, 20 infants (24%) showed growth failure for weight and 14 (18%) for height. Growth failure rates were higher for the SGA infants than for the appropriate-weight-for-gestational age infants at PCA 24 months ( P =0.045 for weight and P =0.038 for height). Growth failure rates were higher for the ELBW infants than for the non-ELBW infants at PCA 24 months ( P <0.001 for weight and P =0.003 for height). Significant differences were found among the WHO, CDC, and Korean standards ( P <0.001). Advancements in neonatal care have improved the catch-up growth of VLBW infants, but this is insufficient. Careful observation and aggressive interventions, especially in SGA and ELBW infants, are needed.

  12. A very rare, petro-clival, neurothekeoma tumor. Case Report

    Directory of Open Access Journals (Sweden)

    Iacob G.

    2015-09-01

    Full Text Available Known as nerve sheath myxoma too, neurothekeoma are benign tumors, usually arise in the skin of the head, neck region and upper extremities, in young females. Cerebral neurothekeoma are very rare, a few cases were already described in the parasellar area, in the middle cranial and posterior fossa. We present a petro-clival neurotekoma. A 78-year-old male was admitted for two years left fronto-temporal headache completed in the last 6 months with left trigeminal V1 neuralgia, left facial hypoesthesia, diplopia, swallowing disorders for liquid foods, balance disorders. From his medical records we noticed: stage 2 chronic kidney disease, hypertension, prostate adenoma, dyslipidemia hypercholesterolemia. The MRI showed a macronodular petroclival mass in hiper T2, hipo T1, flair iso signal; normal cerebral angiography. The patient was operated on using a left retrosigmoid, retromastoidian approach. A 4/3/3 cm tumor, gray, encapsulated, soft consistency, partially cystic, less bleeding, attached to the dura, displacing the basilar artery and brain stem controlateral, encasing the trigeminal nerve. The tumor was totally removed with a good postop evolution. Six months follow up he had no more facial pain, but only persistant left facial hypoesthesia. Histologically the tumor had lobular appearance with spindle or stellate cells embedded in abundant myxoid background. The tumor cells were diffusely positive for S100, PGP9.5’, CD 34” positive in vessels, Ki67’positive in 5%. Cranial MRI performed one month after surgery did not show any residual tumor. Also known as nerve sheath myxomas, neurothekoma are rare benign tumors. For intracranial neurothekoma surgical indication is mandatory

  13. Very high energy emission from passive supermassive black holes

    Energy Technology Data Exchange (ETDEWEB)

    Pedaletti, Giovanna

    2009-10-22

    The H.E.S.S. experiment, an array of four Imaging Cherenkov Telescopes, widened the horizon of Very High Energy (VHE) astronomy. Its unprecedented sensitivity is well suited for the study of new classes of expected VHE emitters, such as passive galactic nuclei that are the main focus of the work presented in this thesis. Acceleration of particles up to Ultra High Energies is expected in the magnetosphere of supermassive black holes (SMBH). The radiation losses of these accelerated particles are expected to reach the VHE regime in which H.E.S.S. operates. Predicted fluxes exceed the sensitivity of the array. However, strong photon fields in the surrounding of the acceleration region might absorb the produced radiation. Therefore observations focus on those galactic nuclei that are underluminous at lower photon energies. This work presents data collected by the H.E.S.S. telescopes on the test candidate NGC 1399 and their interpretation. While no detection has been achieved, important constraints can be derived from the obtained upper limits on the maximum energy attainable by the accelerated particles and on the magnetic field strength in the acceleration region. A limit on the magnetic field of B < 74 Gauss is given. The limit is model dependent and a scaling of the result with the assumptions is given. This is the tightest empirical constraint to date. Because of the lack of signal from the test candidate, a stacking analysis has been performed on similar sources in three cluster fields. A search for signal from classes of active galactic nuclei has also been made in the same three fields. None of the analyzed samples revealed a significant signal. Also presented are the expectations for the next generation of Cherenkov Telescopes and an outlook on the relativistic effects expected on the VHE emission close to SMBH. (orig.)

  14. The Cherenkov Telescope Array For Very High-Energy Astrophysics

    Science.gov (United States)

    Kaaret, Philip

    2015-08-01

    The field of very high energy (VHE) astrophysics had been revolutionized by the results from ground-based gamma-ray telescopes, including the current imaging atmospheric Cherenkov telescope (IACT) arrays: HESS, MAGIC and VERITAS. A worldwide consortium of scientists from 29 countries has formed to propose the Cherenkov Telescope Array (CTA) that will capitalize on the power of this technique to greatly expand the scientific reach of ground-based gamma-ray telescopes. CTA science will include key topics such as the origin of cosmic rays and cosmic particle acceleration, understanding extreme environments in regions close to neutron stars and black holes, and exploring physics frontiers through, e.g., the search for WIMP dark matter, axion-like particles and Lorentz invariance violation. CTA is envisioned to consist of two large arrays of Cherenkov telescopes, one in the southern hemisphere and one in the north. Each array will contain telescopes of different sizes to provide a balance between cost and array performance over an energy range from below 100 GeV to above 100 TeV. Compared to the existing IACT arrays, CTA will have substantially better angular resolution and energy resolution, will cover a much wider energy range, and will have up to an order of magnitude better sensitivity. CTA will also be operated as an open observatory and high-level CTA data will be placed into the public domain; these aspects will enable broad participation in CTA science from the worldwide scientific community to fully capitalize on CTA's potential. This talk will: 1) review the scientific motivation and capabilities of CTA, 2) provide an overview of the technical design and the status of prototype development, and 3) summarize the current status of the project in terms of its proposed organization and timeline. The plans for access to CTA data and opportunities to propose for CTA observing time will be highlighed.Presented on behalf of the CTA Consortium.

  15. Project VISION (Very Intensive Scientific Intercurricular On-Site Education

    Science.gov (United States)

    Roig, Gustavo A.

    1999-01-01

    Project VISION (Very Intensive Scientific Intercurricular On-Site Education) is a joint effort among NASA/John F. Kennedy Space Center, Florida International University, Universidad del Turabo, Miami-Dade County Public Schools and the Caguas/Gurabo Public Schools in Puerto Rico. The project's main mission is to institutionalize change among the elementary and middle school science and math teachers at participating schools so that their students receive continuously enriched instruction in the principles of science and math through the use of hands-on and minds-on experiments called learning modules. These leaming modules incorporate the national science and math education standards provided by the National Committee on Science Education Standards and Assessments and the National Council of Teachers of Mathematics, respectively. The use of learning modules that require hands-on and minds-on activities in a classroom setting garners great enthusiasm and motivation on the part of the target students for the understanding of the lesson's underlying math and science principles. With this enthusiasm and motivation, comes acceptance, attention, participation, discipline, acquiescence, and collaboration. Additionally, the use of hands-on activities may also require learning through a gamut of senses. Not only can the student use his/her eyes and ears during these activities, but most times, they can also use their senses of touch, smell, and taste, as well as intuition. Learning is, therefore, achieved using most or all the human senses. The combination of motivation/enthusiasm and the use of multiple senses creates an ideal environment conducive to leaming at a profound level.

  16. Population based trends in mortality, morbidity and treatment for very preterm- and very low birth weight infants over 12 years

    Directory of Open Access Journals (Sweden)

    Rüegger Christoph

    2012-02-01

    Full Text Available Abstract Background Over the last two decades, improvements in medical care have been associated with a significant increase and better outcome of very preterm (VP, Methods Our population-based observational cohort study used the Minimal Neonatal Data Set, a database maintained by the Swiss Society of Neonatology including information of all VP- and VLBW infants. Perinatal characteristics, mortality and morbidity rates and the survival free of major complications were analysed and their temporal trends evaluated. Results In 1996, 2000, 2004, and 2008, a total number of 3090 infants were enrolled in the Network Database. At the same time the rate of VP- and VLBW neonates increased significantly from 0.87% in 1996 to 1.10% in 2008 (p Conclusions Over the 12-year observation period, the number of VP- and VLBW infants increased significantly. An unchanged overall mortality rate and an increase of survivors free of major complication resulted in a considerable net gain in infants with potentially good outcome.

  17. LEO P: AN UNQUENCHED VERY LOW-MASS GALAXY

    International Nuclear Information System (INIS)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Berg, Danielle; Dolphin, Andrew; Cannon, John M.; Salzer, John J.; Rhode, Katherine L.; Adams, Elizabeth A. K.; Giovanelli, Riccardo; Haynes, Martha P.; Girardi, Léo

    2015-01-01

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H i Arecibo Legacy Fast ALFA survey. The H i and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with active star formation, an underlying older population, and an extremely low oxygen abundance. We have obtained optical imaging with the Hubble Space Telescope to two magnitudes below the red clump in order to study the evolution of Leo P. We refine the distance measurement to Leo P to be 1.62 ± 0.15 Mpc, based on the luminosity of the horizontal branch stars and 10 newly identified RR Lyrae candidates. This places the galaxy at the edge of the Local Group, ∼0.4 Mpc from Sextans B, the nearest galaxy in the NGC 3109 association of dwarf galaxies of which Leo P is clearly a member. The star responsible for ionizing the H ii region is most likely an O7V or O8V spectral type, with a stellar mass ≳25 M ⊙ . The presence of this star provides observational evidence that massive stars at the upper end of the initial mass function are capable of being formed at star formation rates as low as ∼10 −5 M ⊙ yr −1 . The best-fitting star formation history (SFH) derived from the resolved stellar populations of Leo P using the latest PARSEC models shows a relatively constant star formation rate over the lifetime of the galaxy. The modeled luminosity characteristics of Leo P at early times are consistent with low-luminosity dSph Milky Way satellites, suggesting that Leo P is what a low-mass dSph would look like if it evolved in isolation and retained its gas. Despite the very low mass of Leo P, the imprint of reionization on its SFH is subtle at best, and consistent with being totally negligible. The isolation of Leo P, and the total quenching of star formation of Milky Way satellites of similar mass, implies that the local environment dominates the quenching of the Milky Way satellites

  18. Mighty Murines: Neutrino Physics at very high Energy Muon Colliders

    International Nuclear Information System (INIS)

    King, B.J.

    2000-01-01

    An overview is given of the potential for neutrino physics studies through parasitic use of the intense high energy neutrino beams that would be produced at future many-TeV muon colliders. Neutrino experiments clearly cannot compete with the collider physics. Except at the very highest energy muon colliders, the main thrust of the neutrino physics program would be to improve on the measurements from preceding neutrino experiments at lower energy muon colliders, particularly in the fields of B physics, quark mixing and CP violation. Muon colliders at the 10 TeV energy scale might already produce of order 10 8 B hadrons per year in a favorable and unique enough experimental environment to have some analytical capabilities beyond any of the currently operating or proposed B factories. The most important of the quark mixing measurements at these energies might well be the improved measurements of the important CKM matrix elements |V ub | and |V cb | and, possibly, the first measurements of |V td | in the process of flavor changing neutral current interactions involving a top quark loop. Muon colliders at the highest center-of-mass energies that have been conjectured, 100--1,000 TeV, would produce neutrino beams for neutrino-nucleon interaction experiments with maximum center-of-mass energies from 300--1,000 GeV. Such energies are close to, or beyond, the discovery reach of all colliders before the turn-on of the LHC. In particular, they are comparable to the 314 GeV center-of-mass energy for electron-proton scattering at the currently operating HERA collider and so HERA provides a convenient benchmark for the physics potential. It is shown that these ultimate terrestrial neutrino experiments, should they eventually come to pass, would have several orders of magnitude more luminosity than HERA. This would potentially open up the possibility for high statistics studies of any exotic particles, such as leptoquarks, that might have been previously discovered at these

  19. LEO P: AN UNQUENCHED VERY LOW-MASS GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D.; Berg, Danielle [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Salzer, John J.; Rhode, Katherine L. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Adams, Elizabeth A. K. [ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Giovanelli, Riccardo; Haynes, Martha P. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Girardi, Léo, E-mail: kmcquinn@astro.umn.edu [Osservatorio Astronomico di Padova, INAF, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy)

    2015-10-20

    Leo P is a low-luminosity dwarf galaxy discovered through the blind H i Arecibo Legacy Fast ALFA survey. The H i and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with active star formation, an underlying older population, and an extremely low oxygen abundance. We have obtained optical imaging with the Hubble Space Telescope to two magnitudes below the red clump in order to study the evolution of Leo P. We refine the distance measurement to Leo P to be 1.62 ± 0.15 Mpc, based on the luminosity of the horizontal branch stars and 10 newly identified RR Lyrae candidates. This places the galaxy at the edge of the Local Group, ∼0.4 Mpc from Sextans B, the nearest galaxy in the NGC 3109 association of dwarf galaxies of which Leo P is clearly a member. The star responsible for ionizing the H ii region is most likely an O7V or O8V spectral type, with a stellar mass ≳25 M{sub ⊙}. The presence of this star provides observational evidence that massive stars at the upper end of the initial mass function are capable of being formed at star formation rates as low as ∼10{sup −5} M{sub ⊙} yr{sup −1}. The best-fitting star formation history (SFH) derived from the resolved stellar populations of Leo P using the latest PARSEC models shows a relatively constant star formation rate over the lifetime of the galaxy. The modeled luminosity characteristics of Leo P at early times are consistent with low-luminosity dSph Milky Way satellites, suggesting that Leo P is what a low-mass dSph would look like if it evolved in isolation and retained its gas. Despite the very low mass of Leo P, the imprint of reionization on its SFH is subtle at best, and consistent with being totally negligible. The isolation of Leo P, and the total quenching of star formation of Milky Way satellites of similar mass, implies that the local environment dominates the quenching of the Milky Way satellites.

  20. Investigations of Very High Enthalpy Geothermal Resources in Iceland.

    Science.gov (United States)

    Elders, W. A.; Fridleifsson, G. O.

    2012-12-01

    reservoir, without increasing its environmental foot print. If these efforts are successful, in future such very high enthalpy geothermal systems worldwide could become significant energy resources, where ever suitable young volcanic rocks occur, such as in the western USA, Hawaii, and Alaska.

  1. The Very Large Array: Pioneering New Directions in Radio Astronomy

    Science.gov (United States)

    McKinnon, Mark

    2018-01-01

    The Very Large Array (VLA) started science operations in 1980 and was rechristened the Jansky VLA after a major upgrade to its electronics system was completed in 2012. The VLA plays a prominent role in scientific discovery through studies of the Solar System, star and planet formation, galaxy formation, and time domain astronomy. It has attained iconic status as one of the most scientifically productive telescopes on EarthIn 2017, three major initiatives were launched at the VLA with the goal of maintaining its leadership role and impact in radio astronomy in the near and long term future:1. In September, the VLA embarked upon the VLA Sky Survey (VLASS), the highest resolution survey ever undertaken at radio wavelengths. The survey was planned in consultation with the astronomy community and will be used to search for transients, study the polarization properties of extragalactic radio sources, and study highly obscured sources in our Galaxy.2. Detailed planning for a next generation VLA (ngVLA) began in earnest in 2017. The ngVLA will open a new window on the Universe through ultra-sensitive imaging of thermal line and continuum emission down to milliarcsecond resolution, as well as unprecedented broad-band continuum polarimetric imaging of non-thermal processes. A proposal for the instrument will be submitted to the 2020 Decadal Survey.3. A multi-year program to replace the 40+ year old infrastructure at the VLA site was initiated in 2017. The program includes the replacement of the VLA’s electrical infrastructure in 2018, improvements to the VLA rail system, and the replacement of heavy maintenance equipment.The VLA continued to play a major role in discovering and explaining the physics of transient phenomena in 2017, to include fast transients, such as fast radio bursts, and long time scale transients, such as novae, tidal disruption events, and gamma-ray bursts.More thorough descriptions of the VLASS and ngVLA, along with the science that can be done with

  2. A Glimpse of the Very Early Universal Web

    Science.gov (United States)

    2001-05-01

    The VLT Maps Extremely Distant Galaxies Summary New, trailblazing observations with the ESO Very Large Telescope (VLT) at Paranal lend strong support to current computer models of the early universe: It is "spongy", with galaxies forming along filaments, like droplets along the strands of a spiders web. A group of astronomers at ESO and in Denmark [1] determined the distances to some very faint galaxies in the neighbourhood of a distant quasar. Plotting their positions in a three-dimensional map, they found that these objects are located within a narrow "filament", exactly as predicted by the present theories for the development of the first structures in the young universe . The objects are most likely "building blocks" from which galaxies and clusters of galaxies assemble. This observation shows a very useful way forward for the study of the early evolution of the universe and the emergence of structures soon after the Big Bang. At the same time, it provides yet another proof of the great power of the new class of giant optical telescopes for cosmological studies. PR Photo 19a/01 : Web-like structures in the young Universe (computer model). PR Photo 19b/01 : A group of objects at redshift 3.04 . PR Photo 19c/01 : Animated view of sky field and distant filament . PR Photo 19d/01 : The shape of the filament . PR Photo 19e/01 : Artist's impression of the very distant filament. PR Video Clip 04/01 : Video animation of the very distant filament. The computers are ahead of the telescopes For the past two decades cosmologists have been in the somewhat odd situation that their computers were "ahead" of their telescopes. The rapid evolution of powerful computer hardware and sophisticated software has provided theorists with the ability to build almost any sort of virtual universe they can imagine. Starting with different initial conditions just after the Big Bang, they can watch such fictional worlds evolve over billions of years in their supercomputers - and do so in a

  3. Neutronics of a liquid salt cooled - very high temperature reactor

    International Nuclear Information System (INIS)

    Zakova, J.

    2007-01-01

    During last few years, the interest in the innovative, Liquid Salt cooled - Very High Temperature Reactor (LS-VHTR), has been growing. The preconceptual design of the LS-VHTR was suggested in Oak Ridge National Laboratory (ORNL) [1] and nowadays, several research institutions contribute to the development of this concept. The LS-VHTR design utilises a prismatic, High Temperature Reactor (HTR) fuel [2] in combination with liquid salt as a coolant. This connection of high-performance fuel and a coolant with enhanced heat transfer abilities enables efficient and economical operation. Main objective of the LS-VHTR operation may be either an efficient electricity production or a heat supply for a production of hydrogen or, combination of both. The LS-VHTR is moderated by graphite. The graphite matrix of the fuel blocks, as well as the inner and outer core reflectors serve as a thermal buffer in case of an accident, and they provide a strong thermal feedback during normal reactor operation. The high inherent safety of the LS-VHTR meets the strict requirements on future reactor systems, as defined by the Gen IV project. This work, purpose, scope, contribution to the state-of-art: The design, used in the present work is based on the first ORNL suggestion [1]. Recent study is focused on comparison of the neutronic performance of two types of fuel in the LS-VHTR core, whereas, in all previous works, only uranium fuel has been investigated. The first type of fuel, which has been employed in the present analysis, is based on the spent Light Water Reactor (LWR) fuel, whereas the second one consists of enriched uranium oxide. The results of such a comparison bring a valuable knowledge about limits and possibilities of the LS-VHTR concept, when employed as a spent fuel burner. Method:It is used a 3-D drawing of the LS-VHTR core, which contains 324x10 hexagonal fuel blocks. Each fuel block contains 216x10 fuel pins, which consists of TRISO particles incorporated into a graphite

  4. Very deep hole concept. Thermal effects on groundwater flow

    Energy Technology Data Exchange (ETDEWEB)

    Marsic, Niko; Grundfelt, Bertil; Wiborgh, Marie [Kemakta Konsult AB, Stockholm (Sweden)

    2006-09-15

    The purpose of the present study is to investigate the stability of deep groundwater conditions in a repository for spent nuclear fuel based on the Very Deep Hole concept. The study is based on a repository design originally set up in the PASS study. In this design, canisters containing spent nuclear fuel are assumed to be stacked in the lower 2 km of 4 km deep holes and surrounded by a slurry consisting of bentonite and water. The canisters are separated by 'cushions' consisting of 1 m long compacted bentonite blocks. The upper 2 km of the borehole is sealed with bentonite, asphalt and concrete. In all 45 disposal holes, each hosting 300 canisters, is required for the disposal of the spent fuel from operating the Swedish nuclear reactors 40 years. In each disposal hole, a heat source with a decaying power corresponding to the time behaviour of the radioactive decay of the spent disposed nuclear fuel was introduced. The salinity of the groundwater was varied over depth in accordance with the distribution generalised from data available. Correspondingly, the water from the surface down to a depth of 700 m is assumed have a zero salt concentration. In a zone from 700 to 1,500 m depth the salt content of the groundwater increases linearly from zero to 10%. The groundwater below 1,500 m depth is assumed to have a salt content of 10%. The density of the groundwater can be assumed to increase approximately linearly with the salt content such that a groundwater with 10% salt content has a density that is about 10% higher than fresh water. This creates a stable layering of the groundwater system. In order to alter this stability, driving forces have to be applied to the groundwater system. The Connectflow software created by Serco Assurance was used to carry out the modelling applying a coupled variable density and heat transport solution. A finite element grid was created including the 45 disposal holes. The grid was constituted by 264,00 elements with 540

  5. Steady-state emission of blazars at very high energies

    Energy Technology Data Exchange (ETDEWEB)

    Hoehne-Moench, Daniel

    2010-07-01

    One key scientific program of the MAGIC telescope project is the discovery and detection of blazars. They constitute the most prominent extragalactic source class in the very high energy (VHE) {gamma}-ray regime with 29 out of 34 known objects. Therefore a major part of the available observation time was spent in the last years on high-frequency peaked blazars. The selection criteria were chosen to increase the detection probability. As the X-ray flux is believed to be correlated to the VHE {gamma}-ray flux, only X-ray selected sources with a flux F{sub X}>2 {mu}Jy at 1 keV were considered. To avoid strong attenuation of the -rays in the extragalactic infrared background, the redshift was restricted to values between z<0.15 and z<0.4, depending on the declination of the objects. The latter determines the zenith distance during culmination which should not exceed 30 (for z<0.4) and 45 (for z<0.15), respectively. Between August 2005 and April 2009, a sample of 24 X-ray selected high-frequency peaked blazars has been observed with the MAGIC telescope. Three of them were detected including 1ES 1218+304 being the first high-frequency peaked BL Lacertae object (HBL) to be discovered with MAGIC in VHE {gamma}-rays. One previously detected object was not confirmed as VHE emitter in this campaign by MAGIC. A set of 20 blazars previously not detected is treated more closely in this work. In this campaign, during almost four years {proportional_to}450 hrs or {proportional_to}22% of the available observation time for extragalactic objects were dedicated to investigate the baseline emission of blazars and their broadband spectral properties in this emission state. For the sample of 20 objects in a redshift range of 0.018

  6. Very deep hole concept. Thermal effects on groundwater flow

    International Nuclear Information System (INIS)

    Marsic, Niko; Grundfelt, Bertil; Wiborgh, Marie

    2006-09-01

    The purpose of the present study is to investigate the stability of deep groundwater conditions in a repository for spent nuclear fuel based on the Very Deep Hole concept. The study is based on a repository design originally set up in the PASS study. In this design, canisters containing spent nuclear fuel are assumed to be stacked in the lower 2 km of 4 km deep holes and surrounded by a slurry consisting of bentonite and water. The canisters are separated by 'cushions' consisting of 1 m long compacted bentonite blocks. The upper 2 km of the borehole is sealed with bentonite, asphalt and concrete. In all 45 disposal holes, each hosting 300 canisters, is required for the disposal of the spent fuel from operating the Swedish nuclear reactors 40 years. In each disposal hole, a heat source with a decaying power corresponding to the time behaviour of the radioactive decay of the spent disposed nuclear fuel was introduced. The salinity of the groundwater was varied over depth in accordance with the distribution generalised from data available. Correspondingly, the water from the surface down to a depth of 700 m is assumed have a zero salt concentration. In a zone from 700 to 1,500 m depth the salt content of the groundwater increases linearly from zero to 10%. The groundwater below 1,500 m depth is assumed to have a salt content of 10%. The density of the groundwater can be assumed to increase approximately linearly with the salt content such that a groundwater with 10% salt content has a density that is about 10% higher than fresh water. This creates a stable layering of the groundwater system. In order to alter this stability, driving forces have to be applied to the groundwater system. The Connectflow software created by Serco Assurance was used to carry out the modelling applying a coupled variable density and heat transport solution. A finite element grid was created including the 45 disposal holes. The grid was constituted by 264,00 elements with 540,055 nodes. The

  7. Termination of pregnancy among very preterm births and its impact on very preterm mortality : results from ten European population-based cohorts in the MOSAIC study

    NARCIS (Netherlands)

    Papiernik, E.; Zeitlin, J.; Delmas, D.; Draper, E. S.; Gadzinowski, J.; Kuenzel, W.; Cuttini, M.; Di Lallo, D.; Weber, T.; Kollee, L.; Bekaert, A.; Breart, G.

    Objective To study the impact of terminations of pregnancy (TOP) on very preterm mortality in Europe. Design European prospective population-based cohort study. Setting Ten regions from nine European countries participating in the MOSAIC (Models of OrganiSing Access to Intensive Care for very

  8. School performance at nine years of age in very premature and very low birth weight infants : Perinatal risk factors and predictors at five years of age

    NARCIS (Netherlands)

    Hille, E.T.M.; Ouden, A.L. den; Bauer, L.; Oudenrijn, C. van den; Brand, R.; Verloove-Vanhorick, S.P.

    1994-01-01

    To assess the impact of both perinatal disorders and developmental problems identified at preschool age on school performance, we followed a virtually complete birth cohort of very premature (<32 completed weeks of gestation) and very low birth weight infants until they were 9 years of age. In 84%

  9. Changes in quality of life into adulthood after very preterm birth and/or very low birth weight in the Netherlands

    NARCIS (Netherlands)

    Lunenburg, A.; Pal, S.M. van der; Dommelen, P. van. der; Pal-de Bruin, K.M. van der; Bennebroek Gravenhorst, J.; Verrips, G.H.W.

    2013-01-01

    It is important to know the impact of Very Preterm (VP) birth or Very Low Birth Weight (VLBW). The purpose of this study is to evaluate changes in Health-Related Quality of Life (HRQoL) of adults born VP or with a VLBW, between age 19 and age 28. Methods The 1983 nationwide Dutch Project On Preterm

  10. Long term follow-up of health-related quality of life in young adults born very preterm or with a very low birth weight

    NARCIS (Netherlands)

    Verrips, Gijsbert; Brouwer, Leonoor; Vogels, Ton; Taal, Erik; Drossaert, Constance H.C.; Feeny, David; Verheijden, Marieke; Verloove-Vanhorick, Pauline

    2012-01-01

    Background The purpose was, first, to evaluate changes in health-related quality of life (HRQL) in a cohort of very low birth weight (VLBW; <1500 g.) or very preterm (< 32 weeks of gestation) children between ages 14 and 19, and second, to identify correlates of HRQL at age 19. Methods HRQL was

  11. Novel, Functionally Graded Coating System for Reusable, Very High Temperature Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses some of the most challenging materials issues with respect to multi-mission, very high temperature, up to 4000°F, applications. The very...

  12. Associations Among Perinatal Factors and Age of Achievement of Full Oral Feeding in Very Preterm Infants

    Directory of Open Access Journals (Sweden)

    Yea-Shwu Hwang

    2013-10-01

    Conclusion: A regression model incorporating significant predictors to estimate the PMA of full oral feeding in very preterm infants was suggested. It could enhance communication between health professionals and parents about the feeding progress of infants born very prematurely.

  13. Sensory processing difficulties in school-age children born very preterm : An exploratory study

    NARCIS (Netherlands)

    Bröring, Tinka; Königs, Marsh; Oostrom, Kim J.; Lafeber, Harrie N.; Brugman, Anniek; Oosterlaan, Jaap

    Background Very preterm birth has a detrimental impact on the developing brain, including widespread white matter brain abnormalities that threaten efficient sensory processing. Yet, sensory processing difficulties in very preterm children are scarcely studied, especially at school age. Aims To

  14. The Use of Very Low Calorie Diets in the Management of Type 2

    African Journals Online (AJOL)

    normalised following a very low calorie diet (VLCD) (less than (<) ...... obese patients with Type II diabetes: Does inclusion of an intermittent very low calorie ... exercise on weight-loss maintenance after a very-low-calorie diet or low-calorie diet: ...

  15. Young adults with very low birth weight: leaving the parental home and sexual relationships--Helsinki Study of Very Low Birth Weight Adults.

    Science.gov (United States)

    Kajantie, Eero; Hovi, Petteri; Räikkönen, Katri; Pesonen, Anu-Katriina; Heinonen, Kati; Järvenpää, Anna-Liisa; Eriksson, Johan G; Strang-Karlsson, Sonja; Andersson, Sture

    2008-07-01

    Although most children and adults who are born very preterm live healthy lives, they have, on average, lower cognitive scores, more internalizing behaviors, and deficits in social skills. This could well affect their transition to adulthood. We studied the tempo of first leaving the parental home and starting cohabitation with an intimate partner and sexual experience of young adults with very low birth weight (Adults, 162 very low birth weight individuals and 188 individuals who were born at term (mean age: 22.3 years [range: 18.5-27.1]) and did not have any major disability filled out a questionnaire. For analysis of their ages at events which had not occurred in all subjects, we used survival analysis (Cox regression), adjusted for gender, current height, parents' ages at the birth, maternal smoking during pregnancy, parental educational attainment, number of siblings, and parental divorce/death. During their late teens and early adulthood, these very low birth weight adults were less likely to leave the parental home and to start cohabiting with an intimate partner. In gender-stratified analyses, these hazard ratios were similar between genders, but the latter was statistically significant for women only. These very low birth weight adults were also less likely to experience sexual intercourse. This relationship was statistically significant for women but not for men; however, very low birth weight women and men both reported a smaller lifetime number of sex partners than did control subjects. Healthy young adults with very low birth weight show a delay in leaving the parental home and starting sexual activity and partnerships.

  16. Effectiveness of muscle coverage to manage osteomyelitis of very late onset in the irradiated chest wall

    International Nuclear Information System (INIS)

    Funayama, Emi; Minakawa, Hidehiko; Otani, Hidekazu; Saito, Noriko; Oyama, Akihiko; Furukawa, Hiroshi; Hayashi, Toshihiko; Saito, Akira; Yamamoto, Yuhei

    2012-01-01

    Radiation therapy for breast cancer has improved survival rates; however, a consequence of this is treatment-induced complications in longer-living patients. Decades after chest wall irradiation, very late onset radiation-induced osteomyelitis can develop, caused by osteoradionecrosis. This may lead to the development of small, but very refractory, skin ulcers. Many reports recommend well-vascularized tissue coverage after appropriate debridement for irradiation ulcers; however, when the ulcers are of very late onset, this sometimes causes recurrence of ulceration in non-muscle-covered areas after flap transfer. Thus, for very late onset cases, we propose treatment with an absolute muscle flap to cover both the obviously infected focus and the surrounding irradiated area. A muscle flap consisting of the entire latissimus dorsi, the shape of which is very large in the horizontal direction, satisfies this requirement. Latissimus dorsi muscle coverage for the treatment of very late onset osteomyelitis should be reappraised. (author)

  17. Lung Maturation: The Survival Miracle of Very Low Birth Weight Infants

    Directory of Open Access Journals (Sweden)

    Alan H. Jobe

    2010-02-01

    Full Text Available The increased survival of very preterm infants is generally attributed to improved care strategies. This review develops the thesis that the features of abnormal pregnancies responsible for very preterm deliveries also provide an explanation of why very preterm infants often survive. A normal fetus born at 24 weeks is very unlikely to survive. However, pregnancies that result in deliveries at 24 weeks are generally highly abnormal, and may have been so for prolonged periods prior to the preterm deliveries. Inflammatory or vascular developmental abnormalities resulting in very preterm birth can alter fetal development in such a way that organ system maturation is induced. This is supported clinically by the relative lack of very preterm infants with respiratory distress syndrome. Interventions such as antenatal corticosteroid treatment and postnatal surfactant treatment for infants with respiratory distress syndrome and gentle ventilation strategies maximize fetal adaptations to the abnormal fetal environment and improve outcomes.

  18. The Stop Arthritis Very Early (SAVE) trial, an international multicentre, randomised, double-blind, placebo-controlled trial on glucocorticoids in very early arthritis

    NARCIS (Netherlands)

    Machold, Klaus P.; Landewé, Robert; Smolen, Josef S.; Stamm, Tanja A.; van der Heijde, Désirée M.; Verpoort, Kirsten N.; Brickmann, Kerstin; Vázquez-Mellado, Janitzia; Karateev, Dimitri E.; Breedveld, Ferdinand C.; Emery, Paul; Huizinga, Thomas W. J.

    2010-01-01

    Glucocorticoids (GCs) are often used as early arthritis treatment and it has been suggested that they induce remission or at least delay the development of rheumatoid arthritis (RA) and the need to start disease-modifying antirheumatic drugs (DMARDs). To test the effect of GCs on patients with very

  19. Catch-up growth up to ten years of age in children born very preterm or with very low birth weight

    NARCIS (Netherlands)

    Knops, N.B.B.; Sneeuw, K.C.A.; Brand, R.; Hille, E.T.M.; Ouden, A.L. den; Wit, J.M.; Verloove-Vanhorick, S.P.

    2005-01-01

    Background: Improved survival due to advances in neonatal care has brought issues such as postnatal growth and development more to the focus of our attention. Most studies report stunting in children born very preterm and/or small for gestational age. In this article we study the growth pattern of

  20. Irradiation of a very forward calorimeter in the LHC environment: Some consequences

    International Nuclear Information System (INIS)

    Ferrando, A.; Josa, M. I.; Malinin, A.; Martinez-Laso, L.; Pojidaev, V.; Salicio, J. M.

    1994-01-01

    We have computed the level of irradiation in the very forward region (2.5 < | η | < 4.7) 4.7) of an LHC experiment, using the proposed CMS (Compact Solenoidal Detector for LHC) setup. Information about the induced radioactivity in the absorber of a proposed iron/gas Very Forward Calorimeter has been extracted. (Author) 11 refs

  1. Irradiation of a very forward calorimeter in the LHC environment: some consequences

    International Nuclear Information System (INIS)

    Ferrando, A.; Josa, M.I.; Malinin, A.; Martinez-Laso, L.; Pojidaev; V.; Salicio, J.M.

    1994-01-01

    We have computed the level of irradiation in the very forward region (2.5< <4.7) of an LHC experimental, using the proposed CMS (Compact Solenoidal Detector for LHC) setup. Information about the induced radioactivity in the absorber of a proposed iron/gas Very Forward Calorimeter has been extracted. (Author) 11 refs

  2. Irradiation of a very forward calorimeter in the LHC environment: Some consequences

    Energy Technology Data Exchange (ETDEWEB)

    Ferrando, A.; Josa, M. I.; Malinin, A.; Martinez-Laso, L.; Pojidaev, V.; Salicio, J. M.

    1994-07-01

    We have computed the level of irradiation in the very forward region (2.5 < | {eta} | < 4.7) 4.7) of an LHC experiment, using the proposed CMS (Compact Solenoidal Detector for LHC) setup. Information about the induced radioactivity in the absorber of a proposed iron/gas Very Forward Calorimeter has been extracted. (Author) 11 refs.

  3. Outphasing control of gallium nitride based very high frequency resonant converters

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2015-01-01

    In this paper an outphasing modulation control method suitable for line regulation of very high frequency resonant converters is described. The pros and cons of several control methods suitable for very high frequency resonant converters are described and compared to outphasing modulation...

  4. Increased insulin requirements during exercise at very high altitude in type 1 diabetes

    NARCIS (Netherlands)

    de Mol, Pieter; de Vries, Suzanna T.; de Koning, Eelco J. P.; Gans, Rijk O. B.; Tack, Cees J.; Bilo, Henk J. G.

    OBJECTIVE-Safe, very high altitude trekking in subjects with type 1 diabetes requires understanding of glucose regulation at high altitude. We investigated insulin requirements, energy expenditure, and glucose levels at very high altitude in relation to acute mountain sickness (AMS) symptoms in

  5. A Comparison of Aphasia Therapy Outcomes before and after a Very Early Rehabilitation Programme Following Stroke

    Science.gov (United States)

    Godecke, Erin; Ciccone, Natalie A.; Granger, Andrew S.; Rai, Tapan; West, Deborah; Cream, Angela; Cartwright, Jade; Hankey, Graeme J.

    2014-01-01

    Background: Very early aphasia rehabilitation studies have shown mixed results. Differences in therapy intensity and therapy type contribute significantly to the equivocal results. Aims: To compare a standardized, prescribed very early aphasia therapy regimen with a historical usual care control group at therapy completion (4-5 weeks post-stroke)…

  6. Maternal attachment representations after very preterm birth and the effect of early intervention

    NARCIS (Netherlands)

    Meijssen, Dominique; Wolf, Marie-Jeanne; van Bakel, Hedwig; Koldewijn, Karen; Kok, Joke; van Baar, Anneloes

    2011-01-01

    Objective: For very preterm infants the mother-infant relationship may be compromised. Maternal attachment representations 18 (corrected) months after very preterm birth and the effect of the post-discharge Infant Behavioral Assessment and Intervention Program (IBAIP) were studied. The IBAIP is

  7. 76 FR 22667 - Availability of Salmonella Compliance Guide for Small and Very Small Meat and Poultry...

    Science.gov (United States)

    2011-04-22

    ...] Availability of Salmonella Compliance Guide for Small and Very Small Meat and Poultry Establishments That... production of ready-to-eat (RTE) meat and poultry products with respect to Salmonella and other pathogens... This document provides small and very small meat and poultry establishments \\1\\ that manufacture RTE...

  8. Factors associated with successful establishment of breastfeeding in very preterm infants

    DEFF Research Database (Denmark)

    Zachariassen, G; Faerk, J; Grytter, C

    2010-01-01

    To describe feeding practices at hospital discharge in relation to characteristics of the very preterm infants (VPI) and their mothers.......To describe feeding practices at hospital discharge in relation to characteristics of the very preterm infants (VPI) and their mothers....

  9. Middle-School-Age Outcomes in Children with Very Low Birthweight.

    Science.gov (United States)

    Taylor, H. Gerry; Klein, Nancy; Minich, Nori M.; Hack, Maureen

    2000-01-01

    Compared outcomes of middle-school-age children born at very low (less than 750-g) or low birthweights (750 to 1,499-g) and full-term. Found that the very-low-weight group fared less well at school age than the low weight and term groups on cognitive functioning, achievement, behavior, and academic performance. Those without neurosensory disorders…

  10. Mother and Child Behaviour in Very Preterm and Term Dyads at 6 and 8 Years

    Science.gov (United States)

    Jaekel, Julia; Wolke, Dieter; Chernova, Julia

    2012-01-01

    Aim: Mothers of very preterm children have been reported to behave less sensitively and to be more controlling. It is unknown whether this is the result of maternal factors or due to maternal adaptation to children's cognitive problems. Method: We investigated a geographically defined prospective whole-population sample of very low birthweight (…

  11. Neonatal Predictors of Cognitive Ability in Adults Born Very Preterm : A Prospective Cohort Study

    NARCIS (Netherlands)

    Breeman, L.D.; Jaekel, Julia; Baumann, Nicole; Bartmann, Peter; Wolke, Dieter

    Aim To identify neonatal predictors to allow a developmental prognosis of very preterm / very-low birthweight (VP/VLBW) survivors' cognitive abilities into adult life. Method The Bavarian Longitudinal Study is a prospective whole population study that followed 260 VP/VLBW infants from birth to

  12. X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope

    NARCIS (Netherlands)

    Vernet, J.; Dekker, H.; D'Odorico, S.; Kaper, L.; Kjaergaard, P.; Hammer, F.; Randich, S.; Zerbi, F.; Groot, P.J.; Hjorth, J.; Guinouard, I.; Navarro, R.; Adolfse, T.; Albers, P.W.; Amans, J.-P.; Andersen, J.J.; Andersen, M.I.; Binetruy, P.; Bristow, P.; Castillo, R.; Chemla, F.; Christensen, L.; Conconi, P.; Conzelmann, R.; Dam, J.; De Caprio, V.; de Ugarte Postigo, A.; Delabre, B.; Di Marcantonio, P.; Downing, M.; Elswijk, E.; Finger, G.; Fischer, G.; Flores, H.; François, P.; Goldoni, P.; Guglielmi, L.; Haigron, R.; Hanenburg, H.; Hendriks, I.; Horrobin, M.; Horville, D.; Jessen, N.C.; Kerber, F.; Kern, L.; Kiekebusch, M.; Kleszcz, P.; Klougart, J.; Kragt, J.; Larsen, H.H.; Lizon, J.-L.; Lucuix, C.; Mainieri, V.; Manuputy, R.; Martayan, C.; Mason, E.; Mazzoleni, R.; Michaelsen, N.; Modigliani, A.; Moehler, S.; Møller, P.; Norup Sørensen, A.; Nørregaard, P.; Péroux, C.; Patat, F.; Pena, E.; Pragt, J.; Reinero, C.; Rigal, F.; Riva, M.; Roelfsema, R.; Royer, F.; Sacco, G.; Santin, P.; Schoenmaker, T.; Spano, P.; Sweers, E.; ter Horst, R.; Tintori, M.; Tromp, N.; van Dael, P.; van Vliet, H.; Venema, L.; Vidali, M.; Vinther, J.; Vola, P.; Winters, R.; Wistisen, D.; Wulterkens, G.; Zacchei, A.

    2011-01-01

    X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope (VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 to

  13. Lower mortality but higher neonatal morbidity over a decade in very preterm infants

    NARCIS (Netherlands)

    Kleine, M.J.K. de; Ouden, A.L. den; Kollée, L.A.A.; Ilsen, A.; Wassenaer, A.G. van; Brand, R.; Verloove-Vanhorick, S.P.

    2007-01-01

    Better perinatal care has led to better survival of very preterm children, but may or may not have increased the number of children with cerebral and pulmonary morbidity. We therefore investigated the relationship between changes in perinatal care during one decade, and short-term outcome in very

  14. Follow up assessment of very preterm infants at five years of age

    NARCIS (Netherlands)

    Kleine, Martin de

    2005-01-01

    Simultaneous with the improved survival of very preterm and low birth weight infants, the awareness increased that not all survive without sequelae. Mild developmental disturbances that interfere with the acquisition of everyday skills and normal learning appeared to be very frequent and were not

  15. A CMOS transconductance-C filter technique for very high frequencies

    NARCIS (Netherlands)

    Nauta, Bram

    1992-01-01

    CMOS circuits for integrated analog filters at very high frequencies, based on transconductance-C integrators, are presented. First a differential transconductance element based on CMOS inverters is described. With this circuit a linear, tunable integrator for very-high-frequency integrated filters

  16. X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope

    DEFF Research Database (Denmark)

    Vernet, J.; Dekker, H.; D'Odorico, S.

    2011-01-01

    X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope (VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 t...

  17. Measurement of very low alpha activity in water; Medida de muy baja actividad alfa en aguas

    Energy Technology Data Exchange (ETDEWEB)

    Crespo, M T; Acena, M L

    1987-07-01

    Measurement of very low levels of alpha-emitting nuclides in water needs substantial improvements. A system based on the adsorbing properties manganese dioxide eliminates the need for transporting very large volumes of water and increases the sensitivity of the measurement. (Author) 21 refs.

  18. Scalable Newton-Krylov solver for very large power flow problems

    NARCIS (Netherlands)

    Idema, R.; Lahaye, D.J.P.; Vuik, C.; Van der Sluis, L.

    2010-01-01

    The power flow problem is generally solved by the Newton-Raphson method with a sparse direct solver for the linear system of equations in each iteration. While this works fine for small power flow problems, we will show that for very large problems the direct solver is very slow and we present

  19. The Importance of Very High Life Satisfaction for Students' Academic Success

    Science.gov (United States)

    Antaramian, Susan

    2017-01-01

    This study investigated whether very high levels of life satisfaction were associated with academic success at the college level. Three-hundred fifty-seven university students reported on their life satisfaction and various indicators of educational functioning. Participants with very high life satisfaction (top 10%) were compared to those with…

  20. Development of preschool and academic skills in children born very preterm

    NARCIS (Netherlands)

    Aarnoudse-Moens, C.S.H.; Oosterlaan, J.; Duivenvoorden, H.J.; van Goudoever, J.B.; Weisglas-Kuperus, N.

    2011-01-01

    Objective: To examine performance in preschool and academic skills in very preterm (gestational age ≤30 weeks) and term-born comparison children aged 4 to 12 years. Study design: Very preterm children (n = 200; mean age, 8.2 ± 2.5 years) born between 1996 and 2004 were compared with 230 term-born