The fast reactor and energy supply

International Nuclear Information System (INIS)

1979-01-01

The progress made with fast reactor development in many countries is summarised showing that the aim is to provide to the nation concerned an ability to instal fast reactor power stations at the end of this century or early in the next one. Accepting the importance of fast reactors as a potential independent source of energy, problems concerning economics, industrial capability, technical factors, public acceptibility and in particular plutonium management, are discussed. It is concluded that although fast reactors have reached a comparatively advanced stage of development, a number of factors make it likely that their introduction for electricity generation will be a gradual process. Nevertheless it is necessary to complete demonstration and development phases in good time. (U.K.)

Mitochondrial phenotypic flexibility enhances energy savings during winter fast in king penguin chicks.

Science.gov (United States)

Monternier, Pierre-Axel; Marmillot, Vincent; Rouanet, Jean-Louis; Roussel, Damien

2014-08-01

Energy conservation is a key priority for organisms that live in environments with seasonal shortages in resource supplies or that spontaneously fast during their annual cycle. The aim of this study was to determine whether the high fasting endurance of winter-acclimatized king penguin chicks (Aptenodytes patagonicus) is associated with an adjustment of mitochondrial bioenergetics in pectoralis muscle, the largest skeletal muscle in penguins. The rates of mitochondrial oxygen consumption, and ATP synthesis and mitochondrial efficiency (ATP/O ratio) were measured in winter-acclimatized chicks. We used pyruvate/malate and palmitoyl-l-carnitine/malate as respiratory substrates and results from naturally fasted chicks were compared to experimentally re-fed chicks. Bioenergetics analysis of pectoralis muscle revealed that mitochondria are on average 15% more energy efficient in naturally fasted than in experimentally fed chicks, indicating that fasted birds consume less nutrients to sustain their energy-demanding processes. We also found that moderate reductions in temperature from 38°C to 30°C further increase by 23% the energy coupling efficiency at the level of mitochondria, suggesting that king penguin chicks realize additional energy savings while becoming hypothermic during winter. It has been calculated that this adjustment of mitochondrial efficiency in skeletal muscle may contribute to nearly 25% of fasting-induced reduction in mass-specific metabolic rate measured in vivo. The present study shows that the regulation of mitochondrial efficiency triggers the development of an economical management of resources, which would maximize the conservation of endogenous fuel stores by decreasing the cost of living in fasted winter-acclimatized king penguin chicks. © 2014. Published by The Company of Biologists Ltd.

High energy cosmic ray astronomy

International Nuclear Information System (INIS)

Fonseca, V.

1996-01-01

A brief introduction to High Energy Cosmic Ray Astronomy is presented. This field covers a 17 decade energy range (2.10 4 -10 20 ) eV. Recent discoveries done with gamma-ray detectors on-board satellites and ground-based Cherenkov devices are pushing for a fast development of new and innovative techniques, specially in the low energy region which includes the overlapping of satellite and ground-based measurements in the yet unexplored energy range 20 keV-250 GeV. Detection of unexpected extremely high energy events have triggered the interest of the international scientific community. (orig.)

High to ultra-high power electrical energy storage.

Science.gov (United States)

Sherrill, Stefanie A; Banerjee, Parag; Rubloff, Gary W; Lee, Sang Bok

2011-12-14

High power electrical energy storage systems are becoming critical devices for advanced energy storage technology. This is true in part due to their high rate capabilities and moderate energy densities which allow them to capture power efficiently from evanescent, renewable energy sources. High power systems include both electrochemical capacitors and electrostatic capacitors. These devices have fast charging and discharging rates, supplying energy within seconds or less. Recent research has focused on increasing power and energy density of the devices using advanced materials and novel architectural design. An increase in understanding of structure-property relationships in nanomaterials and interfaces and the ability to control nanostructures precisely has led to an immense improvement in the performance characteristics of these devices. In this review, we discuss the recent advances for both electrochemical and electrostatic capacitors as high power electrical energy storage systems, and propose directions and challenges for the future. We asses the opportunities in nanostructure-based high power electrical energy storage devices and include electrochemical and electrostatic capacitors for their potential to open the door to a new regime of power energy.

Adipose Tissue CLK2 Promotes Energy Expenditure during High-Fat Diet Intermittent Fasting.

Science.gov (United States)

Hatting, Maximilian; Rines, Amy K; Luo, Chi; Tabata, Mitsuhisa; Sharabi, Kfir; Hall, Jessica A; Verdeguer, Francisco; Trautwein, Christian; Puigserver, Pere

2017-02-07

A promising approach to treating obesity is to increase diet-induced thermogenesis in brown adipose tissue (BAT), but the regulation of this process remains unclear. Here we find that CDC-like kinase 2 (CLK2) is expressed in BAT and upregulated upon refeeding. Mice lacking CLK2 in adipose tissue exhibit exacerbated obesity and decreased energy expenditure during high-fat diet intermittent fasting. Additionally, tissue oxygen consumption and protein levels of UCP1 are reduced in CLK2-deficient BAT. Phosphorylation of CREB, a transcriptional activator of UCP1, is markedly decreased in BAT cells lacking CLK2 due to enhanced CREB dephosphorylation. Mechanistically, CREB dephosphorylation is rescued by the inhibition of PP2A, a phosphatase that targets CREB. Our results suggest that CLK2 is a regulatory component of diet-induced thermogenesis in BAT through increased CREB-dependent expression of UCP1. Copyright © 2017 Elsevier Inc. All rights reserved.

Vibrational energy relaxation: proposed pathway of fast local chromatin denaturation

International Nuclear Information System (INIS)

Harder, D.; Greinert, R.

2002-01-01

The molecular mechanism responsible for the a component of exchange-type chromosome aberrations, of chromosome fragmentation and of reproductive cell death is one of the unsolved issues of radiation biology. Under review is whether vibrational energy relaxation in the constitutive biopolymers of chromatin, induced by inelastic energy deposition events and mediated via highly excited vibrational states, may provide a pathway of fast local chromatin denaturation, thereby producing the severe DNA lesion able to interact chemically with other, non-damaged chromatin. (author)

Measurement and stabilization of the longitudinal and transversal tune on the fast energy ramp at ELSA

Energy Technology Data Exchange (ETDEWEB)

Eberhardt, Maren [Electron Stretcher Accelerator ELSA, Physikalisches Institut, Universitaet Bonn (Germany)

2008-07-01

At the electron stretcher accelerator ELSA, an external beam of unpolarized or polarized electrons is supplied to experimental set-ups. In order to correct for dynamic effects caused by eddy currents induced on the fast energy ramp, the accelerator tunes have to measured in situ with high precision. The measurements of betatron tunes during the fast energy ramp are based on the excitation of coherent betatron oscillations generated by a pulsed kicker magnet. The betatron frequency is determined by a Fourier analysis of the measured oscillations of the beam position. This technique was successfully applied to measure the horizontal tune on the fast energy ramp. During the fast energy ramp shifts of the betatron tune caused by eddy currents are induced. These tune shifts are measured and corrected when operating the accelerator with polarized beam. Measurements of coherent synchrotron oscillations will also be presented. These are excited by a phase modulation of the acceleration voltage using an electrical phase shifter in the reference RF signal path.

High Intensity Exercise: Can It Protect You from A Fast Food Diet?

Science.gov (United States)

Duval, Christian; Rouillier, Marc-Antoine; Rabasa-Lhoret, Rémi; Karelis, Antony D

2017-08-26

The purpose of this study was to assess the ability of high intensity exercise to counteract the deleterious effects of a fast food diet on the cardiometabolic profile of young healthy men. Fifteen men were subjected to an exclusive fast food diet from a popular fast food restaurant chain (three extra value meals/day + optional snack) for 14 consecutive days. Simultaneously, participants were asked to perform each day high intensity interval training (HIIT) (15 × 60 sec sprint intervals (~90% of maximal heart rate)) on a treadmill. Fast food diet and energy expenditure profiles of the participants during the intervention were assessed as well as body composition (DXA), cardiometabolic profile (lipid, hepatic enzymes, glycated hemoglobin, glucose, insulin, hsC-reactive protein (hsCRP) and blood pressure) and estimated maximal oxygen consumption (VO2 max) pre- and post-experiment. We found significant improvements for fat mass, lean body mass, estimated VO₂ max, fasting glucose, serum lipoprotein(a) and hsCRP after the intervention ( p fast food diet.

Model-dependent estimate on the connection between fast radio bursts and ultra high energy cosmic rays

International Nuclear Information System (INIS)

Li, Xiang; Zhou, Bei; He, Hao-Ning; Fan, Yi-Zhong; Wei, Da-Ming

2014-01-01

The existence of fast radio bursts (FRBs), a new type of extragalatic transient, has recently been established, and quite a few models have been proposed. In this work, we discuss the possible connection between the FRB sources and ultra high energy (>10 18 eV) cosmic rays. We show that in the blitzar model and the model of merging binary neutron stars, which includes the huge energy release of each FRB central engine together with the rather high rate of FRBs, the accelerated EeV cosmic rays may contribute significantly to the observed ones. In other FRB models, including, for example, the merger of double white dwarfs and the energetic magnetar radio flares, no significant EeV cosmic ray is expected. We also suggest that the mergers of double neutron stars, even if they are irrelevant to FRBs, may play a nonignorable role in producing EeV cosmic ray protons if supramassive neutron stars are formed in a sufficient fraction of mergers and the merger rate is ≳ 10 3 yr –1 Gpc –3 . Such a possibility will be unambiguously tested in the era of gravitational wave astronomy.

Fast ignition: Physics progress in the US fusion energy program and prospects for achieving ignition

International Nuclear Information System (INIS)

Key, M.; Andersen, C.; Cowan, T.

2003-01-01

Fast ignition (FI) has significant potential advantages for inertial fusion energy and it is therefore being studied as an exploratory concept in the US fusion energy program. FI is based on short pulse isochoric heating of pre-compressed DT by intense beams of laser accelerated MeV electrons or protons. Recent experimental progress in the study of these two heating processes is discussed. The goal is to benchmark new models in order to predict accurately the requirements for full-scale fast ignition. An overview is presented of the design and experimental testing of a cone target implosion concept for fast ignition. Future prospects and conceptual designs for larger scale FI experiments using planned high energy petawatt upgrades of major lasers in the US are outlined. A long-term road map for FI is defined. (author)

Fasting ghrelin does not predict food intake after short-term energy restriction.

Science.gov (United States)

Blom, Wendy A M; Mars, Monica; Hendriks, Henk F J; de Groot, Lisette C P G M; Stafleu, Annette; Kok, Frans J; de Graaf, Cees

2006-05-01

To study the role of ghrelin as a hunger signal during energy restriction and to test the hypothesis that changes in fasting leptin concentrations during energy restriction are associated with changes in fasting ghrelin concentrations. Thirty-five healthy, lean men (23 +/- 3 years of age; BMI: 22.3 +/- 1.6 kg/m(2)) participated in a controlled intervention study. Fasting ghrelin and leptin concentrations were measured before and after 2 days of 62% energy restriction and after a 2-day period of ad libitum food intake. Energy intake during the latter period was assessed. On average, ghrelin concentrations did not change (0.05 mug/liter; 95% confidence interval, -0.03; 0.12) during energy restriction. Changes in ghrelin concentration during energy restriction were not associated with energy intake during the ad libitum period (r = 0.07; not significant). Ad libitum energy intake was, however, associated with the change in ghrelin concentrations during the same period (r = -0.34; p = 0.05). Ghrelin and leptin concentrations were not associated. In addition, the ratio of percentage changes in ghrelin and leptin during energy restriction was not correlated with ad libitum food intake after energy restriction (r = -0.26; p = 0.14). Fasting ghrelin concentrations did not rise after a 2-day energy restriction regimen. Moreover, changes in ghrelin concentrations during energy restriction were not associated with subsequent ad libitum food intake, suggesting that fasting ghrelin does not act as a hunger signal to the brain. The data did not support our hypothesis that leptin suppresses ghrelin levels.

XOP, a fast versatile processor, as a building block for parallel processing in high energy physics experiments

International Nuclear Information System (INIS)

Baehler, P.; Bosco, N.; Lingjaerde, T.; Ljuslin, C.; Van Praag, A.; Werner, P.

1986-01-01

The XOP processor has been designed for trigger calculation and data compression in high energy physics experiments. Therefore, emphasis has been placed upon fast execution and high input/output rate. The fast execution is achieved by a wide instruction word holding operations which are executed concurrently. Thus, the arithmetic operations, data address calculations, data accessing, condition checking, loop count checking and next instruction evaluation all overlap in time. In conventional micro-processors these operations are performed sequentially. In addition, the instruction set comprises not only the classical computer instructions, but also specialized instructions suitable for trigger calculations, such as bit search, population count, loose compare and vector instructions. In order to achieve a high input/output rate, each XOP ECLine interface board is equipped with an input and an output port which fulfil the LeCroy ECLine specifications. The autonomous input port allows a data rate of 40 Mbytes/sec, while the program controlled output port allows 20 Mbytes/sec. For Fastbus based systems a dual Fastbus master interface is under design which allows to build up a Fastbus multi-processor system. This design is being done in collaboration with LAPP Annecy for the CERN Lep L3 experiment. Their scheme comprises 4-5 XOP processors, each of them with a master interface on a data input segment and a master interface on a data output segment. This paper describes the structure of the XOP processor, the interface capabilities and the software development and debugging tools. (Auth.)

Characterization of the fast electrons distribution produced in a high intensity laser target interaction

Energy Technology Data Exchange (ETDEWEB)

Westover, B. [Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Chen, C. D.; Patel, P. K.; McLean, H. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Beg, F. N., E-mail: fbeg@ucsd.edu [Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093 (United States)

2014-03-15

Experiments on the Titan laser (∼150 J, 0.7 ps, 2 × 10{sup 20} W cm{sup −2}) at the Lawrence Livermore National Laboratory were carried out in order to study the properties of fast electrons produced by high-intensity, short pulse laser interacting with matter under conditions relevant to Fast Ignition. Bremsstrahlung x-rays produced by these fast electrons were measured by a set of compact filter-stack based x-ray detectors placed at three angles with respect to the target. The measured bremsstrahlung signal allows a characterization of the fast electron beam spectrum, conversion efficiency of laser energy into fast electron kinetic energy and angular distribution. A Monte Carlo code Integrated Tiger Series was used to model the bremsstrahlung signal and infer a laser to fast electron conversion efficiency of 30%, an electron slope temperature of about 2.2 MeV, and a mean divergence angle of 39°. Simulations were also performed with the hybrid transport code ZUMA which includes fields in the target. In this case, a conversion efficiency of laser energy to fast electron energy of 34% and a slope temperature between 1.5 MeV and 4 MeV depending on the angle between the target normal direction and the measuring spectrometer are found. The observed temperature of the bremsstrahlung spectrum, and therefore the inferred electron spectrum are found to be angle dependent.

The energy gap and the fast reactor

International Nuclear Information System (INIS)

Hill, J.

1977-01-01

The background to the development of fast reactors is summarized. In Britain, the results of the many experiments performed, the operation of the Dounreay Fast Reactor for the past 18 years and the first year's operation of the larger Prototype Fast Reactor have all been very encouraging, in that they demonstrated that the performance corresponded well with predictions, breeding is possible, and the system is exceptionally stable in operation. The next step in fast reactor engineering is to build a full-scale fast reactor power station. There would seem to be little reason to expect more trouble than could reasonably be expected in constructing any large project of this general nature. However, from an engineering point of view continuity of experience is required. If a decision to build a commercial fast reactor were taken today there would be a 14-year gap between strating this and the start of the Prototype Fast Reactor. This is already much too long. From an environmental standpoint we have to demonstrate that we can manufacture and reprocess fast reacctor fuel for a substantial programme in a way that does not lead to pollution of the environment, and that plutonium-containing fuel can be transported in the quantities required in safety and in a way that does not attract terrorists or require a private army to ensure its security. Finally, we have to find a way to allow many countries to obtain the energy they need from fast reactors, without leading to the proliferation of nuclear weapons or weapons capability. (author)

Effects of Nuclear Energy on Sustainable Development and Energy Security: Sodium-Cooled Fast Reactor Case

Directory of Open Access Journals (Sweden)

Sungjoo Lee

2016-09-01

Full Text Available We propose a stepwise method of selecting appropriate indicators to measure effects of a specific nuclear energy option on sustainable development and energy security, and also to compare an energy option with another. Focusing on the sodium-cooled fast reactor, one of the highlighted Generation IV reactors, we measure and compare its effects with the standard pressurized water reactor-based nuclear power, and then with coal power. Collecting 36 indicators, five experts select seven key indicators to meet data availability, nuclear energy relevancy, comparability among energy options, and fit with Korean energy policy objectives. The results show that sodium-cooled fast reactors is a better alternative than existing nuclear power as well as coal electricity generation across social, economic and environmental dimensions. Our method makes comparison between energy alternatives easier, thereby clarifying consequences of different energy policy decisions.

Profiles of fast ions that are accelerated by high harmonic fast waves in the National Spherical Torus Experiment

International Nuclear Information System (INIS)

Liu, D; Heidbrink, W W; Podesta, M; Ruskov, E; Bell, R E; Fredrickson, E D; Medley, S S; Harvey, R W

2010-01-01

Combined neutral beam injection and high-harmonic fast-wave (HHFW) heating accelerate deuterium fast ions in the National Spherical Torus Experiment (NSTX). With 1.1 MW of HHFW power, the neutron emission rate is about three times larger than in the comparison discharge without HHFW heating. Acceleration of fast ions above the beam injection energy is evident on an E||B type neutral particle analyzer (NPA), a 4-chord solid state neutral particle analyzer (SSNPA) array and a 16-channel fast-ion D-alpha (FIDA) diagnostic. The accelerated fast ions observed by the NPA and SSNPA diagnostics mainly come from passive charge exchange reactions at the edge due to the NPA/SSNPA localization in phase space. The spatial profile of accelerated fast ions that is measured by the FIDA diagnostic is much broader than in conventional tokamaks because of the multiple resonance layers and large orbits in NSTX. The fast-ion distribution function calculated by the CQL3D Fokker-Planck code differs from the measured spatial profile, presumably because the current version of CQL3D uses a zero-banana-width model. In addition, compressional Alfven eigenmode activity is stronger during the HHFW heating and it may affect the fast-ion spatial profile.

High-density and high-ρR fuel assembly for fast-ignition inertial confinement fusion

International Nuclear Information System (INIS)

Betti, R.; Zhou, C.

2005-01-01

Scaling relations to optimize implosion parameters for fast-ignition inertial confinement fusion are derived and used to design high-gain fast-ignition targets. A method to assemble thermonuclear fuel at high densities, high ρR, and with a small-size hot spot is presented. Massive cryogenic shells can be imploded with a low implosion velocity V I on a low adiabat α using the relaxation-pulse technique. While the low V I yields a small hot spot, the low α leads to large peak values of the density and areal density. It is shown that a 750 kJ laser can assemble fuel with V I ≅1.7x10 7 cm/s, α≅0.7, ρ≅400 g/cc, ρR≅3 g/cm 2 , and a hot-spot volume of less than 10% of the compressed core. If fully ignited, this fuel assembly can produce high gains of interest to inertial fusion energy applications

Fasting ghrelin does not predict food intake after short-term energy restriction

NARCIS (Netherlands)

Blom, W.A.M.; Mars, M.; Hendriks, H.F.J.; Groot, de C.P.G.M.; Stafleu, A.; Kok, F.J.; Graaf, de C.

2006-01-01

Objective: To study the role of ghrelin as a hunger signal during energy restriction and to test the hypothesis that changes in fasting leptin concentrations during energy restriction are associated with changes in fasting ghrelin concentrations. Research Methods and Procedures: Thirty-five healthy,

Studies of fast-ion transport induced by energetic particle modes using fast-particle diagnostics with high time resolution in CHS

International Nuclear Information System (INIS)

Isobe, M.; Toi, K.; Suzuki, C.; Nagaoka, K.; Matsushita, H.; Goto, K.

2006-01-01

The purpose of this work is to reveal the effects of the energetic particle mode (EPM) on fast-ion transport and consequent fast-ion loss in the Compact Helical System (CHS). For this purpose, fast particle diagnostics capable of following fast events originating from the EPM (f -5 Tesla at the magnetic probe position. The lost fast-ion probe (LIP) located at the outboard side of the torus indicates that bursting EPMs lead to periodically enhanced losses of co-going fast ions having smaller pitch angles in addition to losses of marginally co-passing fast ions. Coinciding with EPM bursts, the H- light detector viewing the peripheral region at the outboard side also shows large pulsed increases similar to that of the LIP whereas the detector viewing the peripheral region at the inboard side does not. This is also evidence that fast ions are expelled to the outboard side due to the EPM. The charge-exchange neutral particle analyzer indicates that only fast ions whose energy is close to the beam injection energy E b are strongly affected by EPM, suggesting in turn that observed EPMs are excited by fast ions having energy close to E b . (author)

Fast nanostructured carbon microparticle synthesis by one-step high-flux plasma processing

NARCIS (Netherlands)

Aussems, D. U. B.; Bystrov, K.; Dogan, I.; Arnas, C.; Cabié, M.; Neisius, T.; Rasinski, M.; Zoethout, E.; Lipman, P.; van de Sanden, M. C. M.; Morgan, T. W.

2017-01-01

This study demonstrates a fast one-step synthesis method for nanostructured carbon microparticles on graphite samples using high-flux plasma exposure. These structures are considered as potential candidates for energy applications such as Li-ion batteries and supercapacitors. The samples were

Fast nanostructured carbon microparticle synthesis by one-step high-flux plasma processing

NARCIS (Netherlands)

Aussems, D.U.B.; Bystrov, K.E.; Doǧan, I.; Arnas, C.; Cabié, M.; Neisius, T.; Rasinski, M.; Lipman, P.J.L.; van de Sanden, M.C.M.; Morgan, T.W.

This study demonstrates a fast one-step synthesis method for nanostructured carbon microparticles on graphite samples using high-flux plasma exposure. These structures are considered as potential candidates for energy applications such as Li-ion batteries and supercapacitors. The samples were

Fast SMES for generation of high power pulses

International Nuclear Information System (INIS)

Juengst, K.P.; Salbert, H.

1996-01-01

A technique for generation of high power pulses based on a fast SMES has been developed and a model of a power modulator for linear accelerators was built. The basic function of the modulator that generates 2 ms long, approximately 1 MW power pulses at a repetition rate of 10 Hz is described in this paper. A modular construction of the SMES that consists of up to six coils has been chosen to meet the demands of several applications in high energy physics and energy distribution. The rate of change of magnetic field achieved during ramping of the magnet was more than 60 T/s without a quench. The magnet was designed with respect to the high AC losses during repetitive ramping of the SMES. The suitability of mixed matrix superconductors instead of more expensive net frequency wires for this kind of AC stress was investigated. The applied mixed matrix Cu/CuNi/NbTi wire and the construction of a single coil is described

Energy Content of U.S. Fast-Food Restaurant Offerings 14-Year Trends

Science.gov (United States)

Bauer, Katherine W.; Hearst, Mary O.; Earnest, Alicia A.; French, Simone A.; Oakes, J. Michael; Harnack, Lisa J.

2012-01-01

Background Within the past decade there has been increasing attention to the role of fast food in the American diet, including a rise in legislative and media-based efforts that address the healthfulness of fast food. However, no studies have been undertaken to evaluate changes in the energy content of fast-food chain restaurant menu items during this period. Purpose To examine changes in the energy content of lunch/dinner menu offerings at eight of the leading fast-food chain restaurants in the U.S. between 1997/1998 and 2009/2010. Methods Menu offerings and nutrient composition information were obtained from archival versions of the University of Minnesota Nutrition Coordinating Center Food and Nutrient Database. Nutrient composition information for items was updated biannually. Changes in median energy content of all lunch/dinner menu offerings and specific categories of menu items among all restaurants and for individual restaurants were examined. Data were collected between 1997 and 2010 and analysis was conducted in 2011. Results Spanning 1997/1998 and 2009/2010, the number of lunch/dinner menu items offered by the restaurants in the study increased by 53%. Across all menu items, the median energy content remained relatively stable over the study period. Examining specific food categories, the median energy content of desserts and condiments increased, the energy content of side items decreased, and energy content of entrees and drinks remained level. Conclusions While large increases in the number of menu items were observed, there have been few changes in the energy content of menu offerings at the leading fast-food chain restaurants examined in this study. PMID:23079171

Energy content of U.S. fast-food restaurant offerings: 14-year trends.

Science.gov (United States)

Bauer, Katherine W; Hearst, Mary O; Earnest, Alicia A; French, Simone A; Oakes, J Michael; Harnack, Lisa J

2012-11-01

Within the past decade, there has been increasing attention to the role of fast food in the American diet, including a rise in legislative and media-based efforts that address the healthfulness of fast food. However, no studies have been undertaken to evaluate changes in the energy content of fast-food chain restaurant menu items during this period. To examine changes in the energy content of lunch/dinner menu offerings at eight of the leading fast-food chain restaurants in the U.S. between 1997-1998 and 2009-2010. Menu offerings and nutrient composition information were obtained from archival versions of the University of Minnesota Nutrition Coordinating Center Food and Nutrient Database. Nutrient composition information for items was updated biannually. Changes in median energy content of all lunch/dinner menu offerings and specific categories of menu items among all restaurants and for individual restaurants were examined. Data were collected between 1997 and 2010 and analysis was conducted in 2011. Spanning 1997-1998 and 2009-2010, the number of lunch/dinner menu items offered by the restaurants in the study increased by 53%. Across all menu items, the median energy content remained relatively stable over the study period. Examining specific food categories, the median energy content of desserts and condiments increased, the energy content of side items decreased, and energy content of entrées and drinks remained level. Although large increases in the number of menu items were observed, there have been few changes in the energy content of menu offerings at the leading fast-food chain restaurants examined in this study. Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Metrology considerations in a fast emerging new energy sector

DEFF Research Database (Denmark)

Friis Pedersen, Troels

2013-01-01

The wind energy sector is emerging on the global energy scene as a fast new energy sector. In 2002 the globally installed wind energy capacity passed 32GW, corresponding to 0,4% of worlds electricity supply. The last five years the sector increased in installed capacity by 33% per year. A leading...... and loads, and measurements. Measurement institutes are organized in the MEASNET network and arrange regular conformity testing....

Computing trends using graphic processor in high energy physics

CERN Document Server

Niculescu, Mihai

2011-01-01

One of the main challenges in Heavy Energy Physics is to make fast analysis of high amount of experimental and simulated data. At LHC-CERN one p-p event is approximate 1 Mb in size. The time taken to analyze the data and obtain fast results depends on high computational power. The main advantage of using GPU(Graphic Processor Unit) programming over traditional CPU one is that graphical cards bring a lot of computing power at a very low price. Today a huge number of application(scientific, financial etc) began to be ported or developed for GPU, including Monte Carlo tools or data analysis tools for High Energy Physics. In this paper, we'll present current status and trends in HEP using GPU.

How fast is the growth of Total Cross Section at High Energies?

CERN Document Server

Fazal-e-Aleem, M; Sohail-Afzal, Tahir; Ayub-Faridi, M; Qadee-Afzal, M

2003-01-01

Relativistic Heavy Ion Collider and Large Hadron Colliders have special agenda for the measurements of the total cross sections at high energies giving us an opportunity to touch cosmic ray energies. Recent analyses of the cosmic ray data together with earlier experimental measurements at ISR and SPS gives us an insight about the behaviour of this important parameter at asymptotic energies. We will study the growth of total cross section at high energies in the light of various theoretical approaches with special reference to measurements at RHIC and LHC.

High temperature fast reactor for hydrogen production in Brazil

International Nuclear Information System (INIS)

Nascimento, Jamil A. do; Ono, Shizuca; Guimaraes, Lamartine N.F.

2008-01-01

The main nuclear reactors technology for the Generation IV, on development phase for utilization after 2030, is the fast reactor type with high temperature output to improve the efficiency of the thermo-electric conversion process and to enable applications of the generated heat in industrial process. Currently, water electrolysis and thermo chemical cycles using very high temperature are studied for large scale and long-term hydrogen production, in the future. With the possible oil scarcity and price rise, and the global warming, this application can play an important role in the changes of the world energy matrix. In this context, it is proposed a fast reactor with very high output temperature, ∼ 1000 deg C. This reactor will have a closed fuel cycle; it will be cooled by lead and loaded with nitride fuel. This reactor may be used for hydrogen, heat and electricity production in Brazil. It is discussed a development strategy of the necessary technologies and some important problems are commented. The proposed concept presents characteristics that meet the requirements of the Generation IV reactor class. (author)

Fast ignition: Dependence of the ignition energy on source and target parameters for particle-in-cell-modelled energy and angular distributions of the fast electrons

Energy Technology Data Exchange (ETDEWEB)

Bellei, C.; Divol, L.; Kemp, A. J.; Key, M. H.; Larson, D. J.; Strozzi, D. J.; Marinak, M. M.; Tabak, M.; Patel, P. K. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2013-05-15

The energy and angular distributions of the fast electrons predicted by particle-in-cell (PIC) simulations differ from those historically assumed in ignition designs of the fast ignition scheme. Using a particular 3D PIC calculation, we show how the ignition energy varies as a function of source-fuel distance, source size, and density of the pre-compressed fuel. The large divergence of the electron beam implies that the ignition energy scales with density more weakly than the ρ{sup −2} scaling for an idealized beam [S. Atzeni, Phys. Plasmas 6, 3316 (1999)], for any realistic source that is at some distance from the dense deuterium-tritium fuel. Due to the strong dependence of ignition energy with source-fuel distance, the use of magnetic or electric fields seems essential for the purpose of decreasing the ignition energy.

The fast breeder reactor

International Nuclear Information System (INIS)

Collier, J.

1990-01-01

The arguments for and against the fast breeder reactor are debated. The case for the fast reactor is that the world energy demand will increase due to increasing population over the next forty years and that the damage to the global environment from burning fossil fuels which contribute to the greenhouse effect. Nuclear fission is the only large scale energy source which can achieve a cut in the use of carbon based fuels although energy conservation and renewable sources will also be important. Fast reactors produce more energy from uranium than other types of (thermal) reactors such as AGRs and PWRs. Fast reactors would be important from about 2020 onwards especially as by then many thermal reactors will need to be replaced. Fast reactors are also safer than normal reactors. The arguments against fast reactors are largely economic. The cost, especially the capital cost is very high. The viability of the technology is also questioned. (UK)

Comparing the energy required for fine grinding torrefied and fast heat treated pine

International Nuclear Information System (INIS)

Kokko, Lauri; Tolvanen, Henrik; Hämäläinen, Kai; Raiko, Risto

2012-01-01

The purpose of the study was to compare torrefaction to partial pyrolysis conducted with a fast heat treatment process. Both torrefaction and the fast heat treatment tests were performed in a bubbling fluidized bed reactor. The study investigated the anhydrous weight losses, the fine grinding energy requirements, and the lower heating values of the samples produced with the two methods i.e. torrefaction and the fast heat treatment. The effect of particle size to these quantities was also investigated. The measurements demonstrated that the fine grinding energy requirement decreased rapidly as a function of anhydrous weight loss. The overall energy content remaining in the solid product decreased linearly as a function of anhydrous weight loss. The study shows that there is only little difference in the final products of the two processes when using particle sizes less than 4 mm. This means that it is possible to get similar products from the fast heat treatment process that takes only seconds compared to the slower torrefaction process that takes minutes. -- Highlights: ► Fine grinding energy requirement is dependent on anhydrous weight loss. ► A fast heat treatment process of only 10 s is possible for pine wood. ► A particle size of less than 4 mm is required for the fast process.

Energy-resolved fast neutron resonance radiography at CSNS

Science.gov (United States)

Tan, Zhixin; Tang, Jingyu; Jing, Hantao; Fan, Ruirui; Li, Qiang; Ning, Changjun; Bao, Jie; Ruan, Xichao; Luan, Guangyuan; Feng, Changqin; Zhang, Xianpeng

2018-05-01

The white neutron beamline at the China Spallation Neutron Source will be used mainly for nuclear data measurements. It will be characterized by high flux and broad energy spectra. To exploit the beamline as a neutron imaging source, we propose a liquid scintillator fiber array for fast neutron resonance radiography. The fiber detector unit has a small exposed area, which will limit the event counts and separate the events in time, thus satisfying the requirements for single-event time-of-flight (SEToF) measurement. The current study addresses the physical design criteria for ToF measurement, including flux estimation and detector response. Future development and potential application of the technology are also discussed.

Energy-averaged neutron cross sections of fast-reactor structural materials

International Nuclear Information System (INIS)

Smith, A.; McKnight, R.; Smith, D.

1978-02-01

The status of energy-averaged cross sections of fast-reactor structural materials is outlined with emphasis on U.S. data programs in the neutron-energy range 1-10 MeV. Areas of outstanding accomplishment and significant uncertainty are noted with recommendations for future efforts. Attention is primarily given to the main constituents of stainless steel (e.g., Fe, Ni, and Cr) and, secondarily, to alternate structural materials (e.g., V, Ti, Nb, Mo, Zr). Generally, the mass regions of interest are A approximately 50 to 60 and A approximately 90 to 100. Neutron total and elastic-scattering cross sections are discussed with the implication on the non-elastic-cross sections. Cross sections governing discrete-inelastic-neutron-energy transfers are examined in detail. Cross sections for the reactions (n;p), (n;n',p), (n;α), (n;n',α) and (n;2n') are reviewed in the context of fast-reactor performance and/or diagnostics. The primary orientation of the discussion is experimental with some additional attention to the applications of theory, the problems of evaluation and the data sensitivity of representative fast-reactor systems

A Fast Event Preprocessor and Sequencer for the Simbol-X Low Energy Detector

Science.gov (United States)

Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

2009-05-01

The Simbol-X Low Energy Detector (LED), a 128×128 pixel DEPFET (Depleted Field Effect Transistor) array, will be read out at a very high rate (8000 frames/second) and, therefore, requires a very fast on board electronics. We present an FPGA-based LED camera electronics consisting of an Event Preprocessor (EPP) for on board data preprocessing and filtering of the Simbol-X low-energy detector and a related Sequencer (SEQ) to generate the necessary signals to control the readout.

A Fast Event Preprocessor and Sequencer for the Simbol-X Low Energy Detector

International Nuclear Information System (INIS)

Schanz, T.; Tenzer, C.; Maier, D.; Kendziorra, E.; Santangelo, A.

2009-01-01

The Simbol-X Low Energy Detector (LED), a 128x128 pixel DEPFET (Depleted Field Effect Transistor) array, will be read out at a very high rate (8000 frames/second) and, therefore, requires a very fast on board electronics. We present an FPGA-based LED camera electronics consisting of an Event Preprocessor (EPP) for on board data preprocessing and filtering of the Simbol-X low-energy detector and a related Sequencer (SEQ) to generate the necessary signals to control the readout.

RF heating and current drive on NSTX with high harmonic fast waves

International Nuclear Information System (INIS)

Ryan, P.M.

2002-01-01

NSTX is a small aspect ratio tokamak with a large dielectric constant (50-100); under these conditions high harmonic fast waves (HHFW) will readily damp on electrons via Landau damping and TTMP. The HHFW system is a 30 MHz, 12-element array capable of launching both symmetric and directional wave spectra for plasma heating and non-inductive current drive. It has delivered up to 6 MW for short pulses and has routinely operated at ∼3-4 MW for 100-200 ms pulses. Results include strong, centrally-peaked electron heating in both D and He plasmas, for both high and low phase velocity spectra. H-modes were obtained with application of HHFW power alone, with stored energy doubling after the L-H transition. Beta poloidal as large as unity has been obtained with large fractions (0.4) of bootstrap current. A fast ion tail with energies extending up to 140 keV has been observed when HHFW interacts with 80 keV neutral beams; neutron rate and lost ion measurements, as well as modeling, indicate significant power absorption by the fast ions. Radial power deposition profiles are being calculated with ray tracing and kinetic full-wave codes and benchmarked against measurements. (author)

Lymphocytes Mitochondrial Physiology as Biomarker of Energy Metabolism during Fasted and Fed Conditions

Directory of Open Access Journals (Sweden)

Erika Cortez

2012-01-01

Full Text Available Mitochondria are central coordinators of energy metabolism, and changes of their physiology have long been associated with metabolic disorders. Thus, observations of energy dynamics in different cell types are of utmost importance. Therefore, tools with quick and easy handling are needed for consistent evaluations of such interventions. In this paper, our main hypothesis is that during different nutritional situations lymphocytes mitochondrial physiology could be associated with the metabolism of other cell types, such as cardiomyocytes, and consequently be used as metabolic biomarker. Blood lymphocytes and heart muscle fibers were obtained from both fed and 24 h-fasted mice, and mitochondrial analysis was assessed by high-resolution respirometry and western blotting. Carbohydrate-linked oxidation and fatty acid oxidation were significantly higher after fasting. Carnitine palmitoil transferase 1 and uncouple protein 2 contents were increased in the fasted group, while the glucose transporters 1 and 4 and the ratio phosphorylated AMP-activated protein kinase/AMPK did not change between groups. In summary, under a nutritional status modification, mitochondria demonstrated earlier adaptive capacity than other metabolic sensors such as glucose transporters and AMPK, suggesting the accuracy of mitochondria physiology of lymphocytes as biomarker for metabolic changes.

Role of small lead-cooled fast reactors for international deployment in worldwide sustainable nuclear energy supply

International Nuclear Information System (INIS)

Sienicki, J.J.; Wade, D.C.; Moisseytsev, A.

2008-01-01

Most recently, the global nuclear energy partnership (GNEP) has identified, as one of its key objectives, the development and demonstration of concepts for small and medium-sized reactors (SMRs) that can be globally deployed while assuring a high level of proliferation resistance. Lead-cooled systems offer several key advantages in meeting these goals. The small lead-cooled fast reactor concept known as the small secure transportable autonomous reactor (SSTAR) has been under ongoing development as part of the US advanced nuclear energy systems programs. Meeting future worldwide projected energy demands during this century (e.g., 1000 to 2000 GWe by 2050) in a sustainable manner while maintaining CO2 emissions at or below today's level will require massive deployments of nuclear reactors in non-fuel cycle states as well as fuel cycle states. The projected energy demands of non-fuel cycle states will not be met solely through the deployment of Light Water Reactors (LWRs) in those states without using up the world's resources of fissile material (e.g., known plus speculative virgin uranium resources = 15 million tonnes). The present U.S. policy is focused upon domestic deployment of large-scale LWRs and sodium-cooled fast spectrum Advanced Burner Reactors (ABRs) working in a symbiotic relationship that burns existing fissile material while destroying the actinides which are generated. Other major nuclear nations are carrying out the development and deployment of SFR breeders as witness the planning for SFR breeder deployments in France, Japan, China, India, and Russia. Small (less that 300 MWe) and medium (300 to 700 MWe) size reactors are better suited to the growing economies and infrastructures of many non-fuel cycle states and developing nations. For those deployments, fast reactor converters which are fissile self-sufficient by creating as much fissile material as they consume are preferred to breeders that create more fissile material than they consume. Thus

Energy dependence of fast neutron dosimetry using electrochemical etching

International Nuclear Information System (INIS)

Su, S.J.; Morgan, K.Z.

1978-01-01

Registration of fast-neutron induced recoil tracks by the electrochemical etching technique as applied to sensitive Lexan polycarbonate foils provides a simple and inexpensive means of fast neutron personnel dosimetry. The sensitivity (tracks/neutron) of recoil particle registration is given as a function of neutron energy. Neutrons of 7 Li (p,n) 7 Be, 3 T (d,n) 4 He and 9 B, respectively. Results are compared with other studies using other neutron sources and conventional etching method

Error estimation and parameter dependence of the calculation of the fast ion distribution function, temperature, and density using data from the KF1 high energy neutral particle analyzer on Joint European Torus

International Nuclear Information System (INIS)

Schlatter, Christian; Testa, Duccio; Cecconello, Marco; Murari, Andrea; Santala, Marko

2004-01-01

Joint European Torus high energy neutral particle analyzer measures the flux of fast neutrals originating from the plasma core. From this data, the fast ion distribution function f i fast , temperature T i,perpendicular fast , and density n i fast are derived using knowledge of various plasma parameters and of the cross section for the required atomic processes. In this article, a systematic sensitivity study of the effect of uncertainties in these quantities on the evaluation of the neutral particle analyzer f i fast , T i,perpendicular fast , and n i fast is reported. The dominant parameter affecting n i fast is the impurity confinement time and therefore a reasonable estimate of this quantity is necessary to reduce the uncertainties in n i fast below 50%. On the other hand, T i,perpendicular fast is much less sensitive and can certainly be provided with an accuracy of better than 10%

Fast liberation of energy stored using superconductors

International Nuclear Information System (INIS)

Prost, G.; Sole, J.

1967-01-01

After a rapid description of the circumstances in which they first thought of using superconducting materials for the storage and liberation of energy, the authors examine, in comparison to condensers, the energy densities which can thus be stored, the methods used for introducing this energy into the superconducting circuit and for trapping it, and the law governing the discharge of this energy into a purely dissipative impedance. This leads to a derivation of the expression for the energy yield which depends on the characteristics of the switch used for opening the superconducting circuit. An experimental study has been made of a superconducting switch with a view to understanding the various parameters. As a result of this analysis, transitions of this switch, over the whole of its mass, were obtained for periods of a few microseconds, and energy yields close to unity were obtained. The obtention of fast discharges is now no longer a technological problem. (authors) [fr

Fasting leptin and appetite responses induced by a 4-day 65%-energy-restricted diet.

Science.gov (United States)

Mars, M; de Graaf, C; de Groot, C P G M; van Rossum, C T M; Kok, F J

2006-01-01

Animal studies show that the leptin decline after acute severe caloric restriction is a peripheral signal to increase food intake. However, most human studies have failed to observe such a relationship. We studied the acute effects of severe caloric restriction on the association between serum leptin concentrations and subjective appetite. A total of 44 healthy adult men (aged: 43 +/- 5 years; BMI: 27.3 +/- 3.2 kg/m(2)). Fasting serum leptin concentrations and self-perceived appetite levels were measured during a 4-day diet containing 36% of the estimated energy requirements. Appetite levels were assessed with a 10-point Likert scale, reflecting hunger, fullness, desire to eat, prospective consumption and total appetite. After the 4-day energy deficit, fasting leptin concentrations decreased by 39.4% (95% CI: -43.6; -34.9%). This decline was associated with an increase in fasting hunger (r = -0.42; P < 0.01), desire to eat (r = -0.39; P < 0.05) and total appetite (r = -0.38; P < 0.05). Furthermore, the association between fasting leptin concentrations and fasting appetite levels became stronger during the energy restriction period (for total appetite: day 0 r = -0.15, P = 0.32; day 2 r = -0.31, P =< 0.05; day 4 r = -0.41, P < 0.01). The acute proportional reduction in fasting leptin after 4-day energy restriction is associated with an increase in self-perceived appetite. Additionally, the inverse association between proportional fasting leptin concentrations and self-perceived appetite response becomes stronger as energy restriction is prolonged. These findings suggest that leptin has an instrumental role in restoring energy balance in humans through the expression of appetite.

Machine Protection and High Energy Density States in Matter for High Energy Hadron Accelerators

CERN Document Server

Blanco Sancho, Juan; Schmidt, R

The Large Hadron Collider (LHC) is the largest accelerator in the world. It is designed to collide two proton beams with unprecedented particle energy of 7TeV. The energy stored in each beam is 362MJ, sufficient to melt 500kg of copper. An accidental release of even a small fraction of the beam energy can result in severe damage to the equipment. Machine protection systems are essential to safely operate the accelerator and handle all possible accidents. This thesis deals with the study of different failure scenarios and its possible consequences. It addresses failure scenarios ranging from low intensity losses on high-Z materials and superconductors to high intensity losses on carbon and copper collimators. Low beam losses are sufficient to quench the superconducting magnets and the stabilized superconducting cables (bus-bars) that connects the main magnets. If this occurs and the energy from the bus-bar is not extracted fast enough it can lead to a situation similar to the accident in 2008 at LHC during pow...

The use of gas based energy conversion cycles for sodium fast reactors

International Nuclear Information System (INIS)

Saez, M.; Haubensack, D.; Alpy, N.; Gerber, A.; Daid, F.

2008-01-01

In the frame of Sodium Fast Reactors, CEA, AREVA and EDF are involved in a substantial effort providing both significant expertise and original work in order to investigate the interest to use a gas based energy conversion cycle as an alternative to the classical steam cycle. These gas cycles consist in different versions of the Brayton cycle, various types of gas being considered (helium, nitrogen, argon, separately or mixed, sub or supercritical carbon dioxide) as well as various cycle arrangements (indirect, indirect / combined cycles). The interest of such cycles is analysed in details by thermodynamic calculations and cycle optimisations. The objective of this paper is to provide a comparison between gas based energy conversion cycles from the viewpoint of the overall plant efficiency. Key factors affecting the Brayton cycle efficiency include the turbine inlet temperature, compressors and turbine efficiencies, recuperator effectiveness and cycle pressure losses. A nitrogen Brayton cycle at high pressure (between 100 and 180 bar) could appear as a potential near-term solution of classical gas power conversion system for maximizing the plant efficiency. At long-term, supercritical carbon dioxide Brayton cycle appears very promising for Sodium Fast Reactors, with a potential of high efficiency using even at a core outlet temperature of 545 deg. C. (authors)

RF heating and current drive on NSTX with high harmonic fast waves

International Nuclear Information System (INIS)

Ryan, P.M.; Swain, D.W.; Rosenberg, A.L.

2003-01-01

NSTX is a small aspect ratio tokamak (R = 0.85 m, a = 0.65 m). The High Harmonic Fast Wave (HHFW) system is a 30 MHz, 12-element array capable of launching both symmetric and directional wave spectra for plasma heating and non-inductive current drive. It has delivered up to 6 MW for short pulses and has routinely operated at ∼3 MW for 100-400 ms pulses. Results include strong, centrally-peaked electron heating in both D and He plasmas for both high and low phase velocity spectra. H-modes were obtained with application of HHFW power alone, with stored energy doubling after the L-H transition. Beta poloidal as large as unity has been obtained with significant fractions (0.4) of bootstrap current. Differences in the loop voltage are observed depending on whether the array is phased to drive current in the co- or counter-current directions. A fast ion tail with energies extending up to 140 keV has been observed when HHFW interacts with 80 keV neutral beams; neutron rate and lost ion measurements, as well as modeling, indicate significant power absorption by the fast ions. Radial rf power deposition and driven current profiles have been calculated with ray tracing and kinetic full-wave codes and compared with measurements. (author)

High-Resolution Fast-Neutron Spectrometry for Arms Control and Treaty Verification

Energy Technology Data Exchange (ETDEWEB)

David L. Chichester; James T. Johnson; Edward H. Seabury

2012-07-01

Many nondestructive nuclear analysis techniques have been developed to support the measurement needs of arms control and treaty verification, including gross photon and neutron counting, low- and high-resolution gamma spectrometry, time-correlated neutron measurements, and photon and neutron imaging. One notable measurement technique that has not been extensively studied to date for these applications is high-resolution fast-neutron spectrometry (HRFNS). Applied for arms control and treaty verification, HRFNS has the potential to serve as a complimentary measurement approach to these other techniques by providing a means to either qualitatively or quantitatively determine the composition and thickness of non-nuclear materials surrounding neutron-emitting materials. The technique uses the normally-occurring neutrons present in arms control and treaty verification objects of interest as an internal source of neutrons for performing active-interrogation transmission measurements. Most low-Z nuclei of interest for arms control and treaty verification, including 9Be, 12C, 14N, and 16O, possess fast-neutron resonance features in their absorption cross sections in the 0.5- to 5-MeV energy range. Measuring the selective removal of source neutrons over this energy range, assuming for example a fission-spectrum starting distribution, may be used to estimate the stoichiometric composition of intervening materials between the neutron source and detector. At a simpler level, determination of the emitted fast-neutron spectrum may be used for fingerprinting 'known' assemblies for later use in template-matching tests. As with photon spectrometry, automated analysis of fast-neutron spectra may be performed to support decision making and reporting systems protected behind information barriers. This paper will report recent work at Idaho National Laboratory to explore the feasibility of using HRFNS for arms control and treaty verification applications, including simulations

Semiconductor high-energy radiation scintillation detector

International Nuclear Information System (INIS)

Kastalsky, A.; Luryi, S.; Spivak, B.

2006-01-01

We propose a new scintillation-type detector in which high-energy radiation generates electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. An important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombination time of minority carriers. Notably, the fast response comes without any degradation in brightness. When the scintillator is implemented in a qualified semiconductor material (such as InP or GaAs), the photo-detector and associated circuits can be epitaxially integrated on the scintillator slab and the structure can be stacked-up to achieve virtually any desired absorption capability

High energy neutron generator

International Nuclear Information System (INIS)

Barjon, R.; Breynat, G.

1987-01-01

This patent describes a generator of fast neutrons only slightly contaminated by neutrons of energy less than 15 MeV, comprising a source of charged particles of energy equal to at least 15 MeV, a target made of lithium deuteride, and means for cooling the target. The target comprises at least two elements placed in series in the path of the charged particles and separated from each other, the thickness of each of the elements being selected as a function of the average energy of the charged particles emitted from the source and the energy of the fast neutrons to be generated such that neutrons of energy equal to at least 15 MeV are emitted in the forward direction in response to the bombardment of the target from behind by the charged particles. The target cooling means comprises means for circulating between and around the elements a gas which does not chemically react with lithium deuteride

World energy resources, demand and supply of energy, and the prospects for the fast breeder reactor

International Nuclear Information System (INIS)

Haefele, W.

1978-01-01

In the past it was taken for granted that the prime role of fast breeder reactors was to complement light water reactors, mainly because of their similar and compatible fuel cycles. In particular, the plutonium converted in LWRs is most intelligently disposed of and used in FBRs. Evaluation of the time horizon of such reactor strategies generally extended only to the year 2000. It is important to realize, however, that the salient task in the breeder field after 2000 - besides electricity generation - will be to substitute for conventional ''cheap'' oil. Electricity today makes up only 10% to 12% of the total secondary energy, while liquids essentially command up to about 50%. Thus the future application of the FBR technology will have to be geared more to the production of a liquid secondary energy carrier than to electricity. A new yardstick for all these considerations is the strongly rising energy prices. They may double, for example, leading to an oil price of US 24/bbl. Under these circumstances it is prudent to generalize the scope for future fast breeders. The key element of such a new fast breeder strategy would be the production of hydrogen by electrolysis or thermolysis or a combination of both. For example, methanol synthesized from hydrogen and residual fossil fuels would thus become economically attractive. The FBR breeding gain, on the other hand, would be used for the continued supply of LWRs generating electricity. The paper identifies order-of-magnitude considerations most important for such a fast breeder application against a global energy demand scenario for the year 2030. (author)

Effect of an acute fast on energy compensation and feeding behaviour in lean men and women.

Science.gov (United States)

Johnstone, A M; Faber, P; Gibney, E R; Elia, M; Horgan, G; Golden, B E; Stubbs, R J

2002-12-01

Humans appear to defend against energy deficit to a greater extent than energy surplus. Severe dietary energy restriction resulting in 5-30% weight loss often leads to hyperphagia and weight regain in lean subjects. However, the period of time over which fasting is often endured in Western society are far shorter, approximately 1-2 days. This study examined how a 36 h fast effected the subsequent day's energy and nutrient intake in a group of 24 healthy, lean men and women. Subjects underwent two 2 day treatments, termed 'fast' and 'maintenance'. During the 'fast' treatment, subjects were fed a maintenance diet on the day prior to the fast (day -1) to prevent overeating. They then consumed non-energy drinks only, from 20:00 h on day -1 to 08:00 h on day 2 (ad libitum feeding day), thus fasting for 36 h. On the 'maintenance' protocol, subjects received a maintenance diet throughout day 1. Throughout day 2 they had ad libitum access to a range of familiar foods, which were the same for both treatments. Body weight, blood glucose and respiratory quotient were used as compliance checks. Hunger was monitored on day's -1, 1 and 2 for the fast treatment only. On day 2, average energy intake was 10.2 vs 12.2 MJ/day (s.e.d. 1.0) on the post-maintenance and post-fast periods, respectively (P=0.049). Subjects altered feeding behaviour, in response to the fast, only at breakfast time, selecting a higher-fat meal (P<0.005). Compared to day -1, motivation to eat was elevated during the fast (P<0.05). This continued until breakfast was consumed during the re-feeding period (day 2), when values then returned to baseline. These data suggest that a 36 h fast, which generated a negative energy balance of approximately 12 MJ, did not induce a powerful, unconditioned stimulus to compensate on the subsequent day.

Iodine laser of high efficiency and fast repetition rate

Energy Technology Data Exchange (ETDEWEB)

Hohla, K; Witte, K J

1976-07-01

The scaling laws of an iodine laser of high efficiency and fast repetition rate are reported. The laser is pumped with a new kind of low pressure Hg-UV-lamps which convert 32% of the electrical input in UV-light in the absorption band of the iodine laser and which can be fired up to 100 Hz. Details of a 10 kJ/1 nsec system as dimensions, energy density, repetition rate, flow velocity, gas composition and gas pressure and the overall efficiency are given which is expected to be about 2%.

Intermittent fasting, energy balance and associated health outcomes in adults: study protocol for a randomised controlled trial.

Science.gov (United States)

Templeman, Iain; Thompson, Dylan; Gonzalez, Javier; Walhin, Jean-Philippe; Reeves, Sue; Rogers, Peter J; Brunstrom, Jeffrey M; Karagounis, Leonidas G; Tsintzas, Kostas; Betts, James A

2018-02-02

Prior studies have shown that intermittent fasting is capable of producing improvements in body weight and fasted health markers. However, the extent to which intermittent fasting incurs compensatory changes in the components of energy balance and its impact on postprandial metabolism are yet to be ascertained. A total of 30-36 lean participants and 30-36 overweight/obese participants will be recruited to provide two separate study groups who will undergo the same protocol. Following an initial assessment of basic anthropometry and key health markers, measurements of habitual energy intake (weighed food and fluid intake) and physical activity energy expenditure (combined heart rate and accelerometry) will be obtained over 4 weeks under conditions of energy balance. Participants will then be randomly allocated to one of three experimental conditions for 20 days, namely (1) daily calorie restriction (reduce habitual daily energy intake by 25%), (2) intermittent fasting with calorie restriction (alternate between 24-hour periods of fasting and feeding to 150% of habitual daily energy intake), (3) intermittent fasting without calorie restriction (alternate between 24-hour periods of fasting and feeding to 200% of habitual daily energy intake). In addition to continued monitoring of energy intake and physical activity during the intervention, participants will report for laboratory-based assessments of various metabolic parameters both before and after the intervention. Specifically, fasting and postprandial measurements of resting metabolic rate, substrate oxidation, appetite, food preference, and plasma concentrations of key metabolites and hormones will be made, in addition to subcutaneous abdominal adipose tissue biopsies in the fasted state and an assessment of body composition via dual-energy x-ray absorptiometry. Comparing observed changes in these measures across the three intervention arms in each group will establish the impact of intermittent fasting on

Progress in high-energy laser technology

International Nuclear Information System (INIS)

Miyanaga, Noriaki; Kitagawa, Yoneyoshi; Nakatsuka, Masahiro; Kanabe, Tadashi; Okuda, Isao

2005-01-01

The technological development of high-energy lasers is one of the key issues in laser fusion research. This paper reviews several technologies on the Nd:glass laser and KrF excimer laser that are being used in the current laser fusion experiments and related plasma experiments. Based on the GEKKO laser technology, a new high-energy Nd: glass laser system, which can deliver energy from 10 kJ (boad-band operation) to 20 kJ (narrow-band operation), is under construction. The key topics in KrF laser development are improved efficiency and repetitive operation, which aim at the development of a laser driven for fusion reactor. Ultra-intense-laser technology is also very important for fast ignition research. The key technology for obtaining the petawatt output with high beam quality is reviewed. Regarding the uniform laser irradiation required for high-density compression, the beam-smoothing methods on the GEKKO XII laser are reviewed. Finally, we discuss the present status of MJ-class lasers throughout the world, and summarize by presenting the feasibility of various applications of the high-energy lasers to a wide range of scientific and technological fields. (author)

Energy distribution of the fast electron from Cu and CH targets irradiated with fs-laser pulses

International Nuclear Information System (INIS)

Cai Dafeng; Gu Yuqiu; Zheng Zhijian; Zhou Weimin; Jiao Chunye

2014-01-01

In order to investigate the effect of target's material on fast electron energy distribution, the energy distribution of fast electrons from the front and the rear of Cu and CH targets have been measured during the interaction of femtosecond laser-foil targets. The results show that the fast electron spectrums from the front of Cu and CH targets are similar, which show energy distribution of fast electrons depends very little on material of targets. The fast electron spectrums from the rear of Cu and CH targets are obviously dissimilar, which indicate a mighty effect of target material on fast electron transport. The fast electron spectrums from the Cu target is 'soften', which is due to electron recirculation and self-magnetic field produced by electrons transported in the target. The fast electron spectrums from the CH target is a Maxwellian distribution, which is due to collision effect when electrons transport in the target. (authors)

First limits on the very-high energy gamma-ray afterglow emission of a fast radio burst. H.E.S.S. observations of FRB 150418

Science.gov (United States)

H.E.S.S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arakawa, M.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Coffaro, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; Dewilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.'c.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Öttl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de Los Reyes, R.; Richter, S.; Rieger, F.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stycz, K.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.; Superb Collaboration; Jankowski, F.; Keane, E. F.; Petroff, E.

2017-01-01

Aims: Following the detection of the fast radio burst FRB150418 by the SUPERB project at the Parkes radio telescope, we aim to search for very-high energy gamma-ray afterglow emission. Methods: Follow-up observations in the very-high energy gamma-ray domain were obtained with the H.E.S.S. imaging atmospheric Cherenkov telescope system within 14.5 h of the radio burst. Results: The obtained 1.4 h of gamma-ray observations are presented and discussed. At the 99% C.L. we obtained an integral upper limit on the gamma-ray flux of Φγ(E > 350 GeV) FRB 150418. Conclusions: No hints for high-energy afterglow emission of FRB 150418 were found. Taking absorption on the extragalactic background light into account and assuming a distance of z = 0.492 based on radio and optical counterpart studies and consistent with the FRB dispersion, we constrain the gamma-ray luminosity at 1 TeV to L < 5.1 × 1047 erg/s at 99% C.L.

Fast and effective determination of strontium-90 in high volumes water samples

International Nuclear Information System (INIS)

Basarabova, B.; Dulanska, S.

2014-01-01

A simple and fast method was developed for determination of 90 Sr in high volumes of water samples from vicinity of nuclear power facilities. Samples were taken from the environment near Nuclear Power Plants in Jaslovske Bohunice and Mochovce in Slovakia. For determination of 90 Sr was used solid phase extraction using commercial sorbent Analig R Sr-01 from company IBC Advanced Technologies, Inc.. Determination of 90 Sr was performed with dilute solution of HNO 3 (1.5-2 M) and also tested in base medium with NaOH. For elution of 90 Sr was used eluent EDTA with pH in range 8-9. To achieve fast determination, automation was applied, which brings significant reduction of separation time. Concentration of water samples with evaporation was not necessary. Separation was performed immediately after filtration of analyzed samples. The aim of this study was development of less expensive, time unlimited and energy saving method for determination of 90 Sr in comparison with conventional methods. Separation time for fast-flow with volume of 10 dm 3 of water samples was 3.5 hours (flow-rate approximately 3.2 dm 3 / 1 hour). Radiochemical strontium yield was traced by using radionuclide 85 Sr. Samples were measured with HPGe detector (High-purity Germanium detector) at energy E φ = 514 keV. By using Analig R Sr-01 yields in range 72 - 96 % were achieved. Separation based on solid phase extraction using Analig R Sr-01 employing utilization of automation offers new, fast and effective method for determination of 90 Sr in water matrix. After ingrowth of yttrium samples were measured by Liquid Scintillation Spectrometer Packard Tricarb 2900 TR with software Quanta Smart. (authors)

Evaluation of laser-driven ion energies for fusion fast-ignition research

Science.gov (United States)

Tosaki, S.; Yogo, A.; Koga, K.; Okamoto, K.; Shokita, S.; Morace, A.; Arikawa, Y.; Fujioka, S.; Nakai, M.; Shiraga, H.; Azechi, H.; Nishimura, H.

2017-10-01

We investigate laser-driven ion acceleration using kJ-class picosecond (ps) laser pulses as a fundamental study for ion-assisted fusion fast ignition, using a newly developed Thomson-parabola ion spectrometer (TPIS). The TPIS has a space- and weight-saving design, considering its use in an laser-irradiation chamber in which 12 beams of fuel implosion laser are incident, and, at the same time, demonstrates sufficient performance with its detectable range and resolution of the ion energy required for fast-ignition research. As a fundamental study on laser-ion acceleration using a ps pulse laser, we show proton acceleration up to 40 MeV at 1 × 10^{19} W cm^{-2}. The energy conversion efficiency from the incident laser into protons higher than 6 MeV is 4.6%, which encourages the realization of fusion fast ignition by laser-driven ions.

High energy transients: The millisecond domain

Science.gov (United States)

Rao, A. R.

2018-02-01

The search for high energy transients in the millisecond domain has come to the focus in recent times due to the detection of gravitational wave events and the identification of fast radio bursts as cosmological sources. Here we highlight the sensitivity limitations in the currently operating hard X-ray telescopes and give some details of the search for millisecond events in the AstroSat CZT Imager data.

Feasibility of the Precise Energy Calibration for Fast Neutron Spectrometers

Science.gov (United States)

Gaganov, V. V.; Usenko, P. L.; Kryzhanovskaja, M. A.

2017-12-01

Computational studies aimed at improving the accuracy of measurements performed using neutron generators with a tritium target were performed. A measurement design yielding an extremely narrow peak in the energy spectrum of DT neutrons was found. The presence of such a peak establishes the conditions for precise energy calibration of fast-neutron spectrometers.

Physiological response to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups: metabolic rates, energy reserve utilization, and water fluxes.

Science.gov (United States)

Verrier, Delphine; Groscolas, René; Guinet, Christophe; Arnould, John P Y

2009-11-01

Surviving prolonged fasting requires various metabolic adaptations, such as energy and protein sparing, notably when animals are simultaneously engaged in energy-demanding processes such as growth. Due to the intermittent pattern of maternal attendance, subantarctic fur seal pups have to repeatedly endure exceptionally long fasting episodes throughout the 10-mo rearing period while preparing for nutritional independence. Their metabolic responses to natural prolonged fasting (33.4 +/- 3.3 days) were investigated at 7 mo of age. Within 4-6 fasting days, pups shifted into a stage of metabolic economy characterized by a minimal rate of body mass loss (0.7%/day) and decreased resting metabolic rate (5.9 +/- 0.1 ml O(2)xkg(-1)xday(-1)) that was only 10% above the level predicted for adult terrestrial mammals. Field metabolic rate (289 +/- 10 kJxkg(-1)xday(-1)) and water influx (7.9 +/- 0.9 mlxkg(-1)xday(-1)) were also among the lowest reported for any young otariid, suggesting minimized energy allocation to behavioral activity and thermoregulation. Furthermore, lean tissue degradation was dramatically reduced. High initial adiposity (>48%) and predominant reliance on lipid catabolism likely contributed to the exceptional degree of protein sparing attained. Blood chemistry supported these findings and suggested utilization of alternative fuels, such as beta-hydroxybutyrate and de novo synthesized glucose from fat-released glycerol. Regardless of sex and body condition, pups tended to adopt a convergent strategy of extreme energy and lean body mass conservation that appears highly adaptive for it allows some tissue growth during the repeated episodes of prolonged fasting they experience throughout their development.

High-power explosive magnetic energy sources for thermonuclear and physical applications (overview)

Energy Technology Data Exchange (ETDEWEB)

Chernyshev, V K [All-Russian Scientific Institute of Experimental Physics, Sarov (Russian Federation)

1997-12-31

High-power energy sources unavailable up to now are needed to carry out any one project on inertially confined controlled thermonuclear fusion (CTF). Considerable advances have been made in the area of explosive magnetic generators (EGG) as for their output characteristics (high power combined with high energy content). To develop the concept of magnetic cumulation proposed by A.D. Sakharov in 1951, two new approaches to increasing EMC fast operation by two orders (from tens of microseconds to tenths of microseconds) and increasing at the same time the current pulse amplitude by more than one order, were proposed at VNIIEF in the early sixties. The concept aimed at solving the CTF problem by target magnetic compression (MACO) under the effect of an fast-increasing field was proposed (1972) based on VNIIEF achievements, discussed (1976) at the USSR Academy of Sciences and published (1979). The key physical questions are analyzed, the problems to be solved are posed and the results achieved in the experiments with fast-operating high-power EMGs, fast-opening switches, transmitting lines and insulation systems are discussed here. The results obtained in experiments on liner acceleration as well as those on preliminary plasma magnetization and heating, carried out at the constructed EMGs, are discussed briefly. The conclusion is reached that the MACO system is the most suitable one to provide the ignition because the designing of high-power energy sources to be used in this system is practically complete and the concept itself does not need any intermediate transformations of one type of energy into another always accompanied by a decrease in total efficiency. (author). 4 tabs., 14 figs., 21 refs.

Ionizing Energy Depositions After Fast Neutron Interactions in Silicon

CERN Document Server

Bergmann, Benedikt; Caicedo, Ivan; Kierstead, James; Takai, Helio; Frojdh, Erik

2016-01-01

In this study we present the ionizing energy depositions in a 300 μm thick silicon layer after fast neutron impact. With the Time-of-Flight (ToF) technique, the ionizing energy deposition spectra of recoil silicons and secondary charged particles were assigned to (quasi-)monoenergetic neutron energies in the range from 180 keV to hundreds of MeV. We show and interpret representative measured energy spectra. By separating the ionizing energy losses of the recoil silicon from energy depositions by products of nuclear reactions, the competition of ionizing (IEL) and non-ionizing energy losses (NIEL) of a recoil silicon within the silicon lattice was investigated. The data give supplementary information to the results of a previous measurement and are compared with different theoretical predictions.

Decreases in fasting leptin and insulin concentrations after acute energy restriction and subsequent compensation in food intake.

Science.gov (United States)

Mars, Monica; de Graaf, Cees; de Groot, Lisette C P G M; Kok, Frans J

2005-03-01

The decrease in leptin after energy restriction is a starvation signal to the brain. Several studies have found an association between this decrease and subjective appetite; however, no solid data are available on the acute decrease in fasting leptin concentration and subsequent caloric compensation. The objective was to assess the effect of acute decreases in fasting leptin concentrations, induced by energy restriction, on subsequent energy intake compensation. We hypothesized that men with a large decrease in fasting leptin concentrations would have larger ad libitum energy intakes than would men with a small decrease in leptin. Thirty-four male unrestrained eaters [age: 23 +/- 3 y; body mass index (in kg/m(2)): 22.3 +/- 1.6] participated in a semicontrolled intervention study. Fasting serum leptin and insulin concentrations were measured before and 2 d after 62% energy restriction. Energy intake was measured on the 2 following days on which food was provided ad libitum. During energy restriction, fasting leptin and insulin concentrations decreased by 27.2% (95% CI: -34.4%, -19.9%) and 30.7% (95% CI: -41.0%, -20.4%), respectively. Subjects consumed 143 +/- 27% of their estimated energy requirements (18.3 +/- 2.9 MJ) on the first day and 124 +/- 20% (16.0 +/- 2.6 MJ) on the second day of ad libitum intake. No significant correlations were observed between decreases in fasting leptin or insulin concentrations and subsequent ad libitum energy intake; however, decreases in insulin were correlated with an increase in carbohydrate intake (r=-0.49, P < 0.01). Although fasting leptin concentrations decreased significantly during energy restriction and subjects showed compensatory behavior during subsequent ad libitum food intake, no association was observed between the decrease in fasting leptin concentrations and caloric compensation.

OMEGA EP high-energy petawatt laser: progress and prospects

International Nuclear Information System (INIS)

Maywar, D N; Kelly, J H; Waxer, L J; Morse, S F B; Begishev, I A; Bromage, J; Dorrer, C; Edwards, J L; Folnsbee, L; Guardalben, M J; Jacobs, S D; Jungquist, R; Kessler, T J; Kidder, R W; Kruschwitz, B E; Loucks, S J; Marciante, J R; McCrory, R L; Meyerhofer, D D; Okishev, A V

2008-01-01

OMEGA EP (extended performance) is a petawatt-class addition to the existing 30-kJ, 60-beam OMEGA Laser Facility at the University of Rochester. It will enable high-energy picosecond backlighting of high-energy-density experiments and inertial confinement fusion implosions, the investigation of advanced-ignition experiments such as fast ignition, and the exploration of high-energy-density phenomena. The OMEGA EP short-pulse beams have the flexibility to be directed to either the existing OMEGA target chamber, or the new, auxiliary OMEGA EP target chamber for independent experiments. This paper will detail progress made towards activation, which is on schedule for completion in April 2008

The application analysis of high energy electron accelerator in food irradiation processing

International Nuclear Information System (INIS)

Deng Wenmin; Chen Hao; Feng Lei; Zhang Yaqun; Chen Xun; Li Wenjun; Xiang Chengfen; Pei Ying; Wang Zhidong

2012-01-01

Irradiation technology of high energy electron accelerator has been highly concerned in food processing industry with its fast development, especially in the field of food irradiation processing. In this paper, equipment and research situation of high energy electron accelerator were collected, meanwhile, the similarities and differences between high energy electron beam and 60 Co γ-rays were discussed. In order to provide more references of high energy electron beam irradiation, the usages of high energy electron in food irradiation processing was prospected. These information would promote the development of domestic food irradiation industry and give a useful message to irradiation enterprises and researchers. (authors)

Diffraction of high energy electrons

International Nuclear Information System (INIS)

Bourret, A.

1981-10-01

The diffraction of electrons by a crystal is examined to study its structure. As the electron-substance interaction is strong, it must be treated in a dynamic manner. Using the N waves theory and physical optics the base equations giving the wave at the outlet are deduced for a perfect crystal and their equivalence is shown. The more complex case of an imperfect crystal is then envisaged in these two approaches. In both cases, only the diffraction of high energy electrons ( > 50 KeV) are considered since in the diffraction of slow electrons back scattering cannot be ignored. Taking into account an increasingly greater number of beams, through fast calculations computer techniques, enables images to be simulated in very varied conditions. The general use of the Fast Fourier Transform has given a clear cut practical advantage to the multi-layer method [fr

A study of fast electron energy transport in relativistically intense laser-plasma interactions with large density scalelengths

Energy Technology Data Exchange (ETDEWEB)

Scott, R. H. H.; Norreys, P. A. [Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX (United Kingdom); Perez, F.; Baton, S. D. [LULI, Ecole Polytechnique, UMR 7605, CNRS/CEA/UPMC, Route de Saclay, 91128 Palaiseau (France); Santos, J. J.; Nicolai, Ph.; Hulin, S. [Univ. Bordeaux/CNRS/CEA, CELIA, UMR 5107, 33405 Talence (France); Ridgers, C. P. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom); Davies, J. R. [GoLP, Instituto de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Lancaster, K. L.; Trines, R. M. G. M. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX (United Kingdom); Bell, A. R.; Tzoufras, M. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxford OX11 0QX (United Kingdom); Rose, S. J. [Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom)

2012-05-15

A systematic experimental and computational investigation of the effects of three well characterized density scalelengths on fast electron energy transport in ultra-intense laser-solid interactions has been performed. Experimental evidence is presented which shows that, when the density scalelength is sufficiently large, the fast electron beam entering the solid-density plasma is best described by two distinct populations: those accelerated within the coronal plasma (the fast electron pre-beam) and those accelerated near or at the critical density surface (the fast electron main-beam). The former has considerably lower divergence and higher temperature than that of the main-beam with a half-angle of {approx}20 Degree-Sign . It contains up to 30% of the total fast electron energy absorbed into the target. The number, kinetic energy, and total energy of the fast electrons in the pre-beam are increased by an increase in density scalelength. With larger density scalelengths, the fast electrons heat a smaller cross sectional area of the target, causing the thinnest targets to reach significantly higher rear surface temperatures. Modelling indicates that the enhanced fast electron pre-beam associated with the large density scalelength interaction generates a magnetic field within the target of sufficient magnitude to partially collimate the subsequent, more divergent, fast electron main-beam.

Proton multiplicity distributions in high-energy hadron-nuclei collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1979-01-01

The fast proton emission process is analyzed in high-energy hadron-nuclei collisions. The formula describing the proton multiplicity distributions is derived. It describes well enough the proton multiplicity distribution of pion-nuclei and proton-nuclei collisions at 200 and 400 GeV

High-frame rate imaging of two-phase flow in a thin rectangular channel using fast neutrons.

Science.gov (United States)

Zboray, R; Mor, I; Dangendorf, V; Stark, M; Tittelmeier, K; Cortesi, M; Adams, R

2014-08-01

We have demonstrated the feasibility of performing high-frame-rate, fast neutron radiography of air-water two-phase flows in a thin channel with rectangular cross section. The experiments have been carried out at the accelerator facility of the Physikalisch-Technische Bundesanstalt. A polychromatic, high-intensity fast neutron beam with average energy of 6 MeV was produced by 11.5 MeV deuterons hitting a thick Be target. Image sequences down to 10 ms exposure times were obtained using a fast-neutron imaging detector developed in the context of fast-neutron resonance imaging. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two phase flow parameters like the volumetric gas fraction, bubble size and mean bubble velocities have been measured. The first results are promising, improvements for future experiments are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cyclotrons with fast variable and/or multiple energy extraction

Directory of Open Access Journals (Sweden)

C. Baumgarten

2013-10-01

Full Text Available We discuss the possibility in principle of stripping extraction in combination with reverse bends in isochronous separate-sector cyclotrons (and/or fixed field alternating gradient accelerators. If one uses reverse bends between the sectors (instead of or in combination with drifts and places stripper foils at the sector exit edges, the stripped beam has a reduced bending radius and it should be able to leave the cyclotron within the range of the valley—even if the beam is stripped at less than full energy. We are especially interested in stripping of H_{2}^{+}, as it doubles the charge to mass ratio of the ions. However the method could be applied to other ions or ionized molecules as well. For the production of proton beams by stripping extraction of an H_{2}^{+} beam, we discuss possible designs for three types of machines: First, a low-energy cyclotron for the simultaneous production of several beams at multiple energies—for instance 15, 30, and 70 MeV—thus allowing beam delivery on several isotope production targets. In this case it can be an advantage to have a strong energy dependence of the direction of the extracted beam. Second, we consider a fast variable-energy proton machine for cancer therapy that should allow extraction (of the complete beam at all energies in the range of about 70 MeV to about 250 MeV into the same beam line. Third, we consider a high-intensity high-energy machine, where the main design goals are extraction with low losses, low activation of components, and high reliability. Especially if such a machine is considered for an accelerator driven system (ADS, this extraction mechanism has advantages: Beam trips by the failure of electrostatic elements could be avoided and the turn separation would be less critical, which allows operation at lower main cavity voltages. This would in turn reduce the number of rf trips. The price that has to be paid for these advantages is an increase in size and/or field

Metadyn View: Fast web-based viewer of free energy surfaces calculated by metadynamics

Science.gov (United States)

Hošek, Petr; Spiwok, Vojtěch

2016-01-01

Metadynamics is a highly successful enhanced sampling technique for simulation of molecular processes and prediction of their free energy surfaces. An in-depth analysis of data obtained by this method is as important as the simulation itself. Although there are several tools to compute free energy surfaces from metadynamics data, they usually lack user friendliness and a build-in visualization part. Here we introduce Metadyn View as a fast and user friendly viewer of bias potential/free energy surfaces calculated by metadynamics in Plumed package. It is based on modern web technologies including HTML5, JavaScript and Cascade Style Sheets (CSS). It can be used by visiting the web site and uploading a HILLS file. It calculates the bias potential/free energy surface on the client-side, so it can run online or offline without necessity to install additional web engines. Moreover, it includes tools for measurement of free energies and free energy differences and data/image export.

Effect of electron degeneracy on fast-particles energy deposition in dense plasma systems

International Nuclear Information System (INIS)

Johzaki, T.; Nakao, Y.; Nakashima, H.; Kudo, K.

1997-01-01

The effects of electron degeneracy on fast-particles energy deposition in dense plasmas are investigated by making transport calculations for the fast particles. It is found that the degeneracy substantially affects the profiles of energy deposition of 3.52-MeV α-particles. On the other hand, the effect on the energy deposition of 14.1-MeV neutrons is negligibly small because the recoil ions, which transfer the neutron energy to the plasma constituents, are produced in a whole plasma volume due to the long mean-free-path of neutrons. The coupled transport-hydrodynamic calculations show that these effects of degeneracy are negligible in the ignition and burn characteristics of central ignition D-T targets. (author)

Device and method for relativistic electron beam heating of a high-density plasma to drive fast liners

International Nuclear Information System (INIS)

Thode, L.E.

1981-01-01

A device and method for relativistic electron beam heating of a high-density plasma in a small localized region are described. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises dt, dd, hydrogen boron or similar thermonuclear gas at a density of 1017 to 1020 electrons per cubic centimeter. The target gas is ionized prior to application of the electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 mev, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy and momentum into a small localized region of the high-density plasma target. Fast liners disposed in the high-density target plasma are explosively or ablatively driven to implosion by a heated annular plasma surrounding the fast liner which is generated by an annular relativistic electron beam. An azimuthal magnetic field produced by axial current flow in the annular plasma, causes the energy in the heated annular plasma to converge on the fast liner

ATLAS Fast Tracker Status and Tracking at High luminosity LHC

CERN Document Server

Ilic, Nikolina; The ATLAS collaboration

2018-01-01

The LHC’s increase in centre of mass energy and luminosity in 2015 makes controlling trigger rates with high efficiency challenging. The ATLAS Fast TracKer (FTK) is a hardware processor built to reconstruct tracks at a rate of up to 100 kHz and provide them to the high level trigger. The FTK reconstructs tracks by matching incoming detector hits with pre-defined track patterns stored in associative memory on custom ASICs. Inner detector hits are fit to these track patterns using modern FPGAs. This talk describes the electronics system used for the FTK’s massive parallelization. The installation, commissioning and running of the system is happening in 2016, and is detailed in this talk. Tracking at High luminosity LHC is also presented.

A fast charge-integrating sample-and-hold circuit for fast decision-making with calorimeter arrays

International Nuclear Information System (INIS)

Schuler, G.

1982-01-01

This paper describes a fast charge-integrating sample-and-hold circuit, particularly suited to the fast trigger electronics used with large arrays of photomultipliers in total-energy measurements of high-energy particles interactions. During a gate logic pulse, the circuit charges a capacitor with the current fed into the signal input. The output voltage is equal to the voltage developed across the capacitor, which is held until a fast clear discharges the capacitor. The main characteristics of the fast-charge-integrating sample-and-hold circuit are: i) a conversion factor of 1 V/220 pC; ii) a droop rate of 4 mV/μs for a 50 Ω load; and iii) a 1 μs fast-clear time. (orig.)

Fabrication and Characterization of Li-ion Electrodes for High-Power Energy Storage Devices

OpenAIRE

Lai, Chun-Han

2017-01-01

Renewable energy technologies have been a rapidly emerging option to meet future energy demand. However, their systems require stable, high-power storage devices to overcome fluctuating energy outputs for consistent distribution. Since traditional Li-ion batteries (LIB) are not considered to be capable of fast charging and discharging, we have to develop devices with new chemistry for high-power operation. This dissertation focuses on the development of supercapacitors and high-rate batteries...

The Geant4-Based ATLAS Fast Electromagnetic Shower Simulation

CERN Document Server

Barberio, E; Butler, B; Cheung, S L; Dell'Acqua, A; Di Simone, A; Ehrenfeld, W; Gallas, M V; Glasow, A; Hughes, E; Marshall, Z; Müller, J; Placakyte, R; Rimoldi, A; Savard, P; Tsulaia, V; Waugh, A; Young, C C; 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications

2008-01-01

We present a three-pronged approach to fast electromagnetic shower simulation in ATLAS. Parameterisation is used for high-energy, shower libraries for medium-energy, and an averaged energy deposition for very low-energy particles. We present a comparison between the fast simulation and full simulation in an ATLAS Monte Carlo production.

Nucleus fragmentation induced by a high-energy hadron. Pt. 1

International Nuclear Information System (INIS)

Zielinski, P.

1981-08-01

The author gives a review about high-energy hadron reactions on nuclei. Especially he discusses the proton-proton correlation at low relative momentum, the angular distribution of 30-100 MeV protons, and the emission of fast deuterons. (HSI)

High-intensity interval exercise attenuates but does not eliminate endothelial dysfunction after a fast food meal.

Science.gov (United States)

Tucker, Wesley J; Sawyer, Brandon J; Jarrett, Catherine L; Bhammar, Dharini M; Ryder, Justin R; Angadi, Siddhartha S; Gaesser, Glenn A

2018-02-01

We investigated whether two different bouts of high-intensity interval exercise (HIIE) could attenuate postprandial endothelial dysfunction. Thirteen young (27 ± 1 yr), nonexercise-trained men underwent three randomized conditions: 1) four 4-min intervals at 85-95% of maximum heart rate separated by 3 min of active recovery (HIIE 4 × 4), 2) 16 1-min intervals at 85-95% of maximum heart rate separated by 1 min of active recovery (HIIE 16 × 1), and 3) sedentary control. HIIE was performed in the afternoon, ~18 h before the morning fast food meal (1,250 kcal, 63g of fat). Brachial artery flow-mediated dilation (FMD) was performed before HIIE ( baseline 1), during fasting before meal ingestion ( baseline 2), and 30 min, 2 h, and 4 h postprandial. Capillary glucose and triglycerides were assessed at fasting, 30 min, 1 h, 2 h, and 4 h (triglycerides only). Both HIIE protocols increased fasting FMD compared with control (HIIE 4 × 4: 6.1 ± 0.4%, HIIE 16 × 1: 6.3 ± 0.5%, and control: 5.1 ± 0.4%, P fast food meal can attenuate but not entirely eliminate postprandial decreases in FMD. This effect is not dependent on reductions in postprandial lipemia or glycemia. NEW & NOTEWORTHY Two similar high-intensity interval exercise (HIIE) protocols performed ∼18 h before ingestion of a high-energy fast food meal attenuated but did not entirely eliminate postprandial endothelial dysfunction in young men largely by improving fasting endothelial function. Both HIIE protocols produced essentially identical results, suggesting high reproducibility of HIIE effects.

Fast Foods, Organic Foods, Fad Diets

Science.gov (United States)

There is no standard definition of fast food. Generally, fast food is eaten without cutlery, and fast-food restaurants have no wait staff. Failure to have a standardized definition makes it difficult to compare studies. Foods available outside the home tend to be high in energy and fat compared w...

Collective processes in a tokamak with high-energy particles: general problems of the linear theory of Alfven instabilities of a tokamak with high-energy ions

International Nuclear Information System (INIS)

Mikhailovskii, A.B.

1986-01-01

Some general problems of the theory of Alfven instabilities of a tokamak with high-energy ions are considered. It is assumed that such ions are due to either ionization of fast neutral atoms, injected into the tokamak, or production of them under thermo-nuclear conditions. Small-oscillation equations are derived for the Alfven-type waves, which allow for both destabilizing effects, associated with the high-energy particles, and stabilizing ones, such as effects of shear and bulk-plasm dissipation. A high-energy ion contribution is calculated into the growth rate of the Alfven waves. The author considers the role of trapped-electron collisional dissipation

Fast Reliability Assessing Method for Distribution Network with Distributed Renewable Energy Generation

Science.gov (United States)

Chen, Fan; Huang, Shaoxiong; Ding, Jinjin; Ding, Jinjin; Gao, Bo; Xie, Yuguang; Wang, Xiaoming

2018-01-01

This paper proposes a fast reliability assessing method for distribution grid with distributed renewable energy generation. First, the Weibull distribution and the Beta distribution are used to describe the probability distribution characteristics of wind speed and solar irradiance respectively, and the models of wind farm, solar park and local load are built for reliability assessment. Then based on power system production cost simulation probability discretization and linearization power flow, a optimal power flow objected with minimum cost of conventional power generation is to be resolved. Thus a reliability assessment for distribution grid is implemented fast and accurately. The Loss Of Load Probability (LOLP) and Expected Energy Not Supplied (EENS) are selected as the reliability index, a simulation for IEEE RBTS BUS6 system in MATLAB indicates that the fast reliability assessing method calculates the reliability index much faster with the accuracy ensured when compared with Monte Carlo method.

Operation of the LHC with Protons at High Luminosity and High Energy

CERN Document Server

Papotti, Giulia; Alemany-Fernandez, Reyes; Crockford, Guy; Fuchsberger, Kajetan; Giachino, Rossano; Giovannozzi, Massimo; Hemelsoet, Georges-Henry; Höfle, Wolfgang; Jacquet, Delphine; Lamont, Mike; Nisbet, David; Normann, Lasse; Pojer, Mirko; Ponce, Laurette; Redaelli, Stefano; Salvachua, Belen; Solfaroli Camillocci, Matteo; Suykerbuyk, Ronaldus; Uythoven, Jan; Wenninger, Jorg

2016-01-01

In 2015 the Large Hadron Collider (LHC) entered the first year in its second long Run, after a 2-year shutdown that prepared it for high energy. The first two months of beam operation were dedicated to setting up the nominal cycle for proton-proton operation at 6.5 TeV/beam, and culminated with the first physics with 3 nominal bunches/ring at 13 TeV CoM on 3 June. The year continued with a stepwise intensity ramp up that allowed reaching 2244 bunches/ring for a peak luminosity of ~5·10³³ cm⁻²s^{−1} and a total of just above 4 fb-1 delivered to the high luminosity experiments. Beam operation was shaped by the high intensity effects, e.g. electron cloud and macroparticle-induced fast losses (UFOs), which on a few occasions caused the first beam induced quenches at high energy. This paper describes the operational experience with high intensity and high energy at the LHC, together with the issues that had to be tackled along the way.

High-definition velocity-space tomography of fast-ion dynamics

DEFF Research Database (Denmark)

Salewski, Mirko; Geiger, B.; Jacobsen, A.S.

2016-01-01

Velocity-space tomography of the fast-ion distribution function in a fusion plasma is usually a photon-starved tomography method due to limited optical access and signal-to-noise ratio of fast-ion Dα (FIDA) spectroscopy as well as the strive for high-resolution images. In high-definition tomography...... information to reconstruct where in velocity space the measurements and the simulation disagree. This alternative approach is demonstrated for four-view as well as for two-view FIDA measurements. The high-definition tomography tools allow us to study fast ions in sawtoothing plasmas and the formation of NBI...

The effects of diurnal Ramadan fasting on energy expenditure and substrate oxidation in healthy men.

Science.gov (United States)

Alsubheen, Sana'a A; Ismail, Mohammad; Baker, Alicia; Blair, Jason; Adebayo, Adeboye; Kelly, Liam; Chandurkar, Vikram; Cheema, Sukhinder; Joanisse, Denis R; Basset, Fabien A

2017-12-01

The study aimed to examine the effects of diurnal Ramadan fasting (RF) on substrate oxidation, energy production, blood lipids and glucose as well as body composition. Nine healthy Muslim men (fasting (FAST) group) and eight healthy non-practicing men (control (CNT) group) were assessed pre- and post-RF. FAST were additionally assessed at days 10, 20 and 30 of RF in the morning and evening. Body composition was determined by hydrodensitometry, substrate oxidation and energy production by indirect calorimetry, blood metabolic profile by biochemical analyses and energy balance by activity tracker recordings and food log analyses. A significant group×time interaction revealed that chronic RF reduced body mass and adiposity in FAST, without changing lean mass, whereas CNT subjects remained unchanged. In parallel to these findings, a significant main diurnal effect (morning v. evening) of RF on substrate oxidation (a shift towards lipid oxidation) and blood metabolic profile (a decrease in glucose and an increase in total cholesterol and TAG levels, respectively) was observed, which did not vary over the course of the Ramadan. In conclusion, although RF induces diurnal metabolic adjustments (morning v. evening), no carryover effect was observed throughout RF despite the extended daily fasting period (18·0 (sd 0·3) h) and changes in body composition.

Comparison of proton-proton and proton-antiproton scattering at very high energies

International Nuclear Information System (INIS)

Gauron, P.; Nicolescu, B.; Univ. Pierre et Marie Curie, 75 - Paris; Leader, E.

1985-09-01

The ISR results on the differential cross-sections for pp and anti-pp show unambiguously that the crossing-odd amplitude is still important at very high energies. Comparison of ISR and CERN collider anti-pp data suggests that the crossing-odd amplitude is growing maximally fast with energy. We explore the phenomenological consequences of such a ''maximal odderon'' behaviour at TeV energies

Dimensional oscillation. A fast variation of energy embedding gives good results with the AMBER potential energy function.

Science.gov (United States)

Snow, M E; Crippen, G M

1991-08-01

The structure of the AMBER potential energy surface of the cyclic tetrapeptide cyclotetrasarcosyl is analyzed as a function of the dimensionality of coordinate space. It is found that the number of local energy minima decreases as the dimensionality of the space increases until some limit at which point equipotential subspaces appear. The applicability of energy embedding methods to finding global energy minima in this type of energy-conformation space is explored. Dimensional oscillation, a computationally fast variant of energy embedding is introduced and found to sample conformation space widely and to do a good job of finding global and near-global energy minima.

Energy deposition measurements in fast reactor safety experiments with fission thermocouple detectors

International Nuclear Information System (INIS)

Wright, S.A.; Scott, H.L.

1979-01-01

The investigation of phenomena occurring in in-pile fast reactor safety experiments requires an accurate measurement of the time dependent energy depositions within the fissile material. At Sandia Laboratories thin-film fission thermocouples are being developed for this purpose. These detectors have high temperature capabilities (400 to 500 0 C), are sodium compatible, and have milli-second time response. A significant advantage of these detectors for use as energy deposition monitors is that they produce an output voltage which is directly dependent on the temperature of a small chip of fissile material within the detectors. However, heat losses within the detector make it necessary to correct the response of the detector to determine the energy deposition. A method of correcting the detector response which uses an inverse convolution procedure has been developed and successfully tested with experimental data obtained in the Sandia Pulse Reactor (SPR-II) and in the Annular Core Research Reactor

Laser pulse propagation and enhanced energy coupling to fast electrons in dense plasma gradients

International Nuclear Information System (INIS)

Gray, R J; Carroll, D C; Yuan, X H; Brenner, C M; Coury, M; Quinn, M N; Tresca, O; McKenna, P; Burza, M; Wahlström, C-G; Lancaster, K L; Neely, D; Lin, X X; Li, Y T

2014-01-01

Laser energy absorption to fast electrons during the interaction of an ultra-intense (10 20 W cm −2 ), picosecond laser pulse with a solid is investigated, experimentally and numerically, as a function of the plasma density scale length at the irradiated surface. It is shown that there is an optimum density gradient for efficient energy coupling to electrons and that this arises due to strong self-focusing and channeling driving energy absorption over an extended length in the preformed plasma. At longer density gradients the laser filaments, resulting in significantly lower overall energy coupling. As the scale length is further increased, a transition to a second laser energy absorption process is observed experimentally via multiple diagnostics. The results demonstrate that it is possible to significantly enhance laser energy absorption and coupling to fast electrons by dynamically controlling the plasma density gradient. (paper)

Upgrading ATLAS Fast Calorimeter Simulation

CERN Document Server

Heath, Matthew Peter; The ATLAS collaboration

2017-01-01

Producing the very large samples of simulated events required by many physics and performance studies with the ATLAS detector using the full GEANT4 detector simulation is highly CPU intensive. Fast simulation tools are a useful way of reducing CPU requirements when detailed detector simulations are not needed. During the LHC Run-1, a fast calorimeter simulation (FastCaloSim) was successfully used in ATLAS. FastCaloSim provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitization and reconstruction software, and it can be tuned to data more easily than Geant4. Now an improved version of FastCaloSim is in development, incorporating the experience with the version used during Run-1. The new FastCaloSim aims to overcome some limitations of the first version by improving the description of s...

HIGH-ENERGY PARTICLES FLUX ORIGIN IN THE CLOUDS, DARK LIGHTNING

Directory of Open Access Journals (Sweden)

Kuznetsov, V.V.

2016-11-01

Full Text Available Problem of high-energy particles flux origin in clouds is discussed. Conditions in which dark lightning preceding the ordinary one and creating additional ionization, fluxes of fast electrons with MeV energy prior to the earthquake detected among lightning initiating ball-lightning, glow, sprites are considered. All above phenomena appear to be of general nature founded on quantum entanglement of hydrogen bonds protons in water clasters inside clouds.

Design of high current bunching system and high power fast Faraday cup for high current LEBT at VECC

International Nuclear Information System (INIS)

Anuraag Misra, A.; Pandit, B.V.S.; Gautam Pal, C.

2011-01-01

A high current microwave ion source as described is currently operational at VECC. We are able to optimize 6.4 mA of proton current in the LEBT line of ion source. The cyclotron type of accelerators accept only a fraction of DC ion beam coming from ion source so a ion beam buncher is needed to increase the accepted current into the cyclotron. The buncher described in this paper is unique in its kind as it has to handle high beam loading power upto 400 W as it is designed to bunch few mA of proton beam currents at 80 keV beam energy. A sinusoidal quarter wave RF structure has been chosen to bunch the high current beam due to high Q achievable in comparison with other configurations. This buncher has been designed using CST Microwave studio 3D advanced code since the design frequency of our buncher is 42 MHz, we have provided the RF and vacuum window near the drift tube of buncher to avoid vacuum and multipacting problems and to keep maximum volume in air region. There is a provision of multipacting interlocks to shut off amplifier during multipacting. We have carried out a detailed electromagnetic and thermal design of the buncher in CST Microwave studio and simulated values of unloaded Q was calculated be 4000. We have estimated a power of 400 W to achieve gap (designed) voltage of 10 kV. This buncher is in advanced stage of fabrication. A high power fast Faraday cup is also designed to characterize the above mentioned high current bunching system. The fast Faraday cup is designed in 50 Ω coaxial geometry to transmit fast pulse of bunched ion beam. The design of Faraday cup was completed using ANSYS HFSS and a bandwidth of 1.75 GHz was achieved this faraday cup design was different from conventional Faraday cup design as we have designed the support and cooling lines at such a place on Faraday cup which do not disturb the electrical impedance of the cup. (author)

The ATLAS Fast Tracker and Tracking at the High-Luminosity LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00236423; The ATLAS collaboration

2016-01-01

The LHC’s increase in centre of mass energy and luminosity in 2015 makes controlling trigger rates with high efficiency challenging. The ATLAS Fast TracKer (FTK) is a hardware processor built to reconstruct tracks at a rate of up to 100 kHz and provide them to the high level trigger. The FTK reconstructs tracks by matching incoming detector hits with pre-defined track patterns stored in associative memory on custom ASICs. Inner detector hits are fit to these track patterns using modern FPGAs. These procedings describe the electronics system used for the FTK’s massive parallelization. An overview of the installation, commissioning and running of the system is given. The ATLAS upgrades planned to enable tracking at the High Luminosity LHC are also discussed.

Lethal and mutagenic effects of fast neutrons of different energy on Streptomyces griseus spores

International Nuclear Information System (INIS)

Podgorskaya, M.E.; Tulina, G.G.; Serdechnaya, A.I.; Matselyukh, B.P.

1986-01-01

A study was made of lethal and mutagenic effects of fast neutrons of different energy on spores of prototrophic and auxotrophic strains of Streptomyces griseus. Relative biological effectiveness of fast neutrons is higher than that of γ-rays and depends on beam energy. Neutrons of 22-50 MeV induce Streptomyces griseus mutations more frequently (by one order of magnitude) than neutrons of 1.4-1.6 MeV do. The obtained mutants can be used in studying Streptomyces griseus genetics

A fast event preprocessor for the Simbol-X Low-Energy Detector

Science.gov (United States)

Schanz, T.; Tenzer, C.; Kendziorra, E.; Santangelo, A.

2008-07-01

The Simbol-X1 Low Energy Detector (LED), a 128 × 128 pixel DEPFET array, will be read out very fast (8000 frames/second). This requires a very fast onboard data preprocessing of the raw data. We present an FPGA based Event Preprocessor (EPP) which can fulfill this requirements. The design is developed in the hardware description language VHDL and can be later ported on an ASIC technology. The EPP performs a pixel related offset correction and can apply different energy thresholds to each pixel of the frame. It also provides a line related common-mode correction to reduce noise that is unavoidably caused by the analog readout chip of the DEPFET. An integrated pattern detector can block all invalid pixel patterns. The EPP has an internal pipeline structure and can perform all operation in realtime (< 2 μs per line of 64 pixel) with a base clock frequency of 100 MHz. It is utilizing a fast median-value detection algorithm for common-mode correction and a new pattern scanning algorithm to select only valid events. Both new algorithms were developed during the last year at our institute.

Comparison of neutron and high-energy X-ray dual-beam radiography for air cargo inspection

International Nuclear Information System (INIS)

Liu, Y.; Sowerby, B.D.; Tickner, J.R.

2008-01-01

Dual-beam radiography techniques utilising various combinations of high-energy X-rays and neutrons are attractive for screening bulk cargo for contraband such as narcotics and explosives. Dual-beam radiography is an important enhancement to conventional single-beam X-ray radiography systems in that it provides additional information on the composition of the object being imaged. By comparing the attenuations of transmitted dual high-energy beams, it is possible to build a 2D image, colour coded to indicate material. Only high-energy X-rays, gamma-rays and neutrons have the required penetration to screen cargo containers. This paper reviews recent developments and applications of dual-beam radiography for air cargo inspection. These developments include dual high-energy X-ray techniques as well as fast neutron and gamma-ray (or X-ray) radiography systems. High-energy X-ray systems have the advantage of generally better penetration than neutron systems, depending on the material being interrogated. However, neutron systems have the advantage of much better sensitivity to material composition compared to dual high-energy X-ray techniques. In particular, fast neutron radiography offers the potential to discriminate between various classes of organic material, unlike dual energy X-ray techniques that realistically only offer the ability to discriminate between organic and metal objects

Live cell imaging combined with high-energy single-ion microbeam

Science.gov (United States)

Guo, Na; Du, Guanghua; Liu, Wenjing; Guo, Jinlong; Wu, Ruqun; Chen, Hao; Wei, Junzhe

2016-03-01

DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10-3 s-1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10-2 s-1.

Microdosimetry of intermediate energy neutrons in fast neutron fields

International Nuclear Information System (INIS)

Saion, E.B.; Watt, D.E.

1988-01-01

A coaxial double cylindrical proportional counter has been constructed for microdosimetry of intermediate energy neutrons in mixed fields. Details are given of the measured gas gain and resolution characteristics of the counter for a wide range of anode voltages. Event spectra due to intermediate neutrons in any desired energy band is achieved by an appropriate choice of thickness of the common dividing wall in the counter and by appropriate use of the coincidence, anticoincidence pulse counting arrangements. Calculated estimates indicate that the dose contribution by fast neutrons to the energy deposition events in the intermediate neutron range may be as large as 25%. Empirical procedures being investigated aim to determine the necessary corrections to be applied to the microdose distributions, with a precision of 10%. (author)

Energy metabolism and fasting in male and female insectivorous bats Molossus molossus (Chiroptera: Molossidae

Directory of Open Access Journals (Sweden)

MB. Freitas

Full Text Available Metabolic adaptations induced by 24 and 48 hours of fasting were investigated in male and female insectivorous bats (Molossus molossus Pallas, 1766. For this purpose, plasma glucose, non esterified fatty acids (NEFA, glycogen, protein and lipids concentrations in liver and muscles were obtained. Data presented here demonstrate that fed bats showed plasma glucose levels similar to those reported for other mammal species. In response to fasting, glycemia was decreased only in 48 hours fasted females. Plasma NEFA levels were similar in both sexes, and did not exhibit any changes during fasting. Considering the data from energy reserve variations, fed females presented an increased content of liver glycogen as well as higher breast muscle protein and limbs lipids concentrations, compared to fed males. In response to fasting, liver and muscle glycogen levels remained unchanged. Considering protein and lipid reserves, only females showed decreased values following fasting, as seen in breast, limbs and carcass lipids and breast muscle protein reserves, but still fail to keep glucose homeostasis after 48 hours without food. Taken together, our data suggest that the energy metabolism of insectivorous bats may vary according to sexual differences, a pattern that might be associated to different reproduction investments and costs between genders.

The importance of anisotropic scattering in high energy neutron transport problems

International Nuclear Information System (INIS)

Prillinger, G.; Mattes, M.

1984-01-01

To describe the highly anisotropic scattering of very fast neutrons adequately the transport code ANISN has been improved. Fokker-Planck terms have been introduced into the transport equation which accurately describe the small changes in energy and angle. The new code has been tested for a d(50)-Be neutron source in a deep penetration iron problem. The influence of the forward peaked elastic scattering on the fast neutron spectrum is shown to be significant and can be handled efficiently in the new ANISN version. Since common cross-section libraries are limited by Legendre expansion, or by their upper energy boundary, or exclude elastic scattering above 20 MeV a special library has been created. (Auth.)

Energy and traffic light labelling have no impact on parent and child fast food selection.

Science.gov (United States)

Dodds, Pennie; Wolfenden, Luke; Chapman, Kathy; Wellard, Lyndal; Hughes, Clare; Wiggers, John

2013-10-25

Labelling of food from fast food restaurants at point-of-purchase has been suggested as one strategy to reduce population energy consumption and contribute to reductions in obesity prevalence. The aim of this study was to examine the effects of energy and single traffic light labelling systems on the energy content of child and adult intended food purchases. The study employed a randomised controlled trial design. English speaking parents of children aged between three and 12 years were recruited from an existing research cohort. Participants were mailed one of three hypothetical fast food menus. Menus differed in their labelling technique- either energy labels, single traffic light labels, or a no-label control. Participants then completed a telephone survey which assessed intended food purchases for both adult and child. The primary trial outcome was total energy of intended food purchase. A total of 329 participants completed the follow-up telephone interview. Eighty-two percent of the energy labelling group and 96% of the single traffic light labelling group reported noticing labelling information on their menu. There were no significant differences in total energy of intended purchases of parents, or intended purchases made by parents for children, between the menu labelling groups, or between menu labelling groups by socio-demographic subgroups. This study provided no evidence to suggest that energy labelling or single traffic light labelling alone were effective in reducing the energy of fast food items selected from hypothetical fast food menus for purchase. Additional complementary public health initiatives promoting the consumption of healthier foods identified by labelling, and which target other key drivers of menu item selection in this setting may be required. Copyright © 2013. Published by Elsevier Ltd.

Modified source of a fast neutral atom beam with a controlled energy

International Nuclear Information System (INIS)

Gostev, V.A.; Elakhovskij, D.V.; Khakhaev, A.D.

1980-01-01

A source of a metastable helium atom beam with a controlled energy based on a phenomenon of resonant ion neutralization on the surface of a solid body is described. The neutral particle energy control is carried out by changing ion velocities before their transformation into metastable atoms. The results of experiments with a modified construction of atomic beam source are stated. These experiments were conducted to find the possibilities to control velocities of atoms in a flow as well as to elucidate the peculiarities of operation of a collimator-converter of this construction. Dependences of a halfwidth of the ion velocity distribution function on the ion source parameters have been investigated. The possibility for particle energy control in a collimated flow of fast neutral. atoms has been experimentally shown, it is also shown that a mean value of atom energy in a beam coincides with a value of mean energy of ions from which atoms are produced by the resonant neutralization method; the construction of the source provides the possibility to realize the method of ''overtaking beams'' for neutral atoms and as a result of this to give a possibility for studying atom-atom collisions in a wide energy range at relatively high densities of flows

The effects of Ramadan fasting on activity and energy expenditure.

Science.gov (United States)

Lessan, Nader; Saadane, Ilham; Alkaf, Budour; Hambly, Catherine; Buckley, Adam J; Finer, Nick; Speakman, John R; Barakat, Maha T

2018-01-01

Fasting during the month of Ramadan entails abstinence from eating and drinking between dawn and sunset and a major shift in meal times and patterns with associated changes in several hormones and circadian rhythms; whether there are accompanying changes in energy metabolism is unclear. We have investigated the impact of Ramadan fasting on resting metabolic rate (RMR), activity, and total energy expenditure (TEE). Healthy nonobese volunteers (n = 29; 16 women) fasting during Ramadan were recruited. RMR was measured with the use of indirect calorimetry. In subgroups of participants, activity (n = 11; 5 women) and TEE (n = 10; 5 women) in free-living conditions were measured with the use of accelerometers and the doubly labeled water technique, respectively. Body composition was measured with the use of bioelectrical impedance. Measurements were repeated after a wash-out period of between 1 and 2 mo after Ramadan. Nonparametric tests were used for comparative statistics. Ramadan fasting did not result in any change in RMR (mean ± SD: 1365.7 ± 230.2 compared with 1362.9 ± 273.6 kcal/d for Ramadan and post-Ramadan respectively, P = 0.713, n = 29). However, controlling for the effects of age, sex, and body weight, RMR was higher in the first week of Ramadan than in subsequent weeks. During Ramadan, the total number of steps walked were significantly lower (n = 11, P = 0.001), while overall sleeping time was reduced and different sleeping patterns were seen. TEE did not differ significantly between Ramadan and post-Ramadan (mean ± SD: 2224.1 ± 433.7 compared with 2121.0 ± 718.5 kcal/d for Ramadan and post-Ramadan, P = 0.7695, n = 10). Ramadan fasting is associated with reduced activity and sleeping time, but no significant change in RMR or TEE. Reported weight changes with Ramadan in other studies are more likely to be due to differences in food intake. This trial is registered at clinicaltrials.gov as NCT02696421. © 2018 American Society for Nutrition. All rights

High energy diets-induced metabolic and prediabetic painful polyneuropathy in rats.

Directory of Open Access Journals (Sweden)

Fang Xie

Full Text Available To establish the role of the metabolic state in the pathogenesis of polyneuropathy, an age- and sex-matched, longitudinal study in rats fed high-fat and high-sucrose diets (HFSD or high-fat, high-sucrose and high-salt diets (HFSSD relative to controls was performed. Time courses of body weight, systolic blood pressure, fasting plasma glucose (FPG, insulin, free fatty acids (FFA, homeostasis model assessment-insulin resistance index (HOMA-IR, thermal and mechanical sensitivity and motor coordination were measured in parallel. Finally, large and small myelinated fibers (LMF, SMF as well as unmyelinated fibers (UMF in the sciatic nerves and ascending fibers in the spinal dorsal column were quantitatively assessed under electron microscopy. The results showed that early metabolic syndrome (hyperinsulinemia, dyslipidemia, and hypertension and prediabetic conditions (impaired fasting glucose could be induced by high energy diet, and these animals later developed painful polyneuropathy characterized by myelin breakdown and LMF loss in both peripheral and central nervous system. In contrast SMF and UMF in the sciatic nerves were changed little, in the same animals. Therefore the phenomenon that high energy diets induce bilateral mechanical, but not thermal, pain hypersensitivity is reflected by severe damage to LMF, but mild damage to SMF and UMF. Moreover, dietary sodium (high-salt deteriorates the neuropathic pathological process induced by high energy diets, but paradoxically high salt consumption, may reduce, at least temporarily, chronic pain perception in these animals.

High Energy Diets-Induced Metabolic and Prediabetic Painful Polyneuropathy in Rats

Science.gov (United States)

Hou, Jun-Feng; Jiao, Kai; Costigan, Michael; Chen, Jun

2013-01-01

To establish the role of the metabolic state in the pathogenesis of polyneuropathy, an age- and sex-matched, longitudinal study in rats fed high-fat and high-sucrose diets (HFSD) or high-fat, high-sucrose and high-salt diets (HFSSD) relative to controls was performed. Time courses of body weight, systolic blood pressure, fasting plasma glucose (FPG), insulin, free fatty acids (FFA), homeostasis model assessment-insulin resistance index (HOMA-IR), thermal and mechanical sensitivity and motor coordination were measured in parallel. Finally, large and small myelinated fibers (LMF, SMF) as well as unmyelinated fibers (UMF) in the sciatic nerves and ascending fibers in the spinal dorsal column were quantitatively assessed under electron microscopy. The results showed that early metabolic syndrome (hyperinsulinemia, dyslipidemia, and hypertension) and prediabetic conditions (impaired fasting glucose) could be induced by high energy diet, and these animals later developed painful polyneuropathy characterized by myelin breakdown and LMF loss in both peripheral and central nervous system. In contrast SMF and UMF in the sciatic nerves were changed little, in the same animals. Therefore the phenomenon that high energy diets induce bilateral mechanical, but not thermal, pain hypersensitivity is reflected by severe damage to LMF, but mild damage to SMF and UMF. Moreover, dietary sodium (high-salt) deteriorates the neuropathic pathological process induced by high energy diets, but paradoxically high salt consumption, may reduce, at least temporarily, chronic pain perception in these animals. PMID:23451227

Development of pulsed high current drivers for fast Z-pinch

International Nuclear Information System (INIS)

Sun Fengju; Qiu Aici; Zeng Zhengzhong; Zeng Jiangtao; Kuai Bin; Yang Hailiang

2006-01-01

It is required that the peak current of high power pulsed drive for fast Z-pinch reaches 60 MA to realize inertial confine fusion (ICF) and high yield (HY). With the conventional technological methods similar to the Z or Saturn apparatus, increasing driver current further is impractical and difficult according to the cost, structure complexity and reliability of the driver, so it is necessary to develop novel fast pulsed high current driver. The present art-of-state and trends of fast Z-pinch driver are summarized, and the typical conceptual designs and technological methods on ICF/HY PRS (plasma radiation source) and destroying-level super X-ray simulators in USA and Russia are outlined, such as HCEI's UGXX1 driver and new Saturn driver based on fast linear transformer driver (FLTD) and novel driver based on fast Marx generator (FMG) with current of 15 MA. The crucial technological problems and requirements to investigate in the future are presented. (authors)

Measurement of the fast electron distribution in laser-plasma experiments in the context of the 'fast ignition' approach to inertial confinement fusion

International Nuclear Information System (INIS)

Batani, Dimitri; Morace, Alessio

2010-01-01

The recent 'fast ignition approach' to ICF relies on the presence of fast electrons to provide the 'external' ignition spark triggering the nuclear fusion reaction in the compressed core of a thermonuclear target. Such fast electron beam is produced by the interaction of a short-pulse high-intensity laser with the target itself. In this context, it becomes essential to characterize the density of fast electrons and their average energy (i.e. the 'laser to fast electron' energy conversion efficiency) but also the finer details of the velocity and angular distribution. In this work we will discuss several techniques used to determine the fast electron distribution function.

Thermogenesis induced by a high-carbohydrate meal in fasted lean and overweight young men: insulin, body fat, and sympathetic nervous system involvement.

Science.gov (United States)

Marques-Lopes, Iva; Forga, Luis; Martínez, J Alfredo

2003-01-01

This dietary trial was designed to evaluate the effect of an experimental short-term fasting period followed by a high-carbohydrate meal on energy expenditure, thermogenesis, and sympathetic nervous system activity in normal (body mass index 27 kg/m(2)) men who were healthy, non-diabetic or with no other endocrine disease, non-smokers, not taking oral prescription medications, and with a stable body weight for the previous 3 mo. Fasting and fed energy expenditures and diet-induced thermogenesis were measured after a high-carbohydrate meal in seven overweight and six lean young male subjects by indirect calorimetry. Heart rate, urinary excretion of catecholamines, serum glucose, and insulin were also measured over the experimental fasting (7.5 h) and postprandial (4 h) periods. After carbohydrate intake, overweight men showed a significantly higher energy production (kJ/kg of fat-free mass) than did lean individuals, and the diet-induced thermogenesis (percentage of energy intake) was positively correlated with body fat (kg), percentage of body fat, fat-free mass (kg), and fasting pre-meal serum insulin levels. Postprandial cumulative energy expenditure was directly associated with postprandial insulin response and with mean postprandial heart rate values. No significant differences in urinary catecholamines were found between lean and overweight men at basal conditions or during the study period. Overweight individuals showed similar short-term sympathetic nervous system responses induced by an experimental fasting period. Although diet-induced thermogenesis after carbohydrate intake was not statistically different between lean and overweight men, the postprandial insulin response and body fat content seemed to be involved in sympathetic nervous system activity.

Solar Assisted Fast Pyrolysis: A Novel Approach of Renewable Energy Production

Directory of Open Access Journals (Sweden)

Mohammad U. H. Joardder

2014-01-01

Full Text Available Biofuel produced by fast pyrolysis from biomass is a promising candidate. The heart of the system is a reactor which is directly or indirectly heated to approximately 500°C by exhaust gases from a combustor that burns pyrolysis gas and some of the by-product char. In most of the cases, external biomass heater is used as heating source of the system while internal electrical heating is recently implemented as source of reactor heating. However, this heating system causes biomass or other conventional forms of fuel consumption to produce renewable energy and contributes to environmental pollution. In order to overcome these, the feasibility of incorporating solar energy with fast pyrolysis has been investigated. The main advantages of solar reactor heating include renewable source of energy, comparatively simpler devices, and no environmental pollution. A lab scale pyrolysis setup has been examined along with 1.2 m diameter parabolic reflector concentrator that provides hot exhaust gas up to 162°C. The study shows that about 32.4% carbon dioxide (CO2 emissions and almost one-third portion of fuel cost are reduced by incorporating solar heating system. Successful implementation of this proposed solar assisted pyrolysis would open a prospective window of renewable energy.

Korea-China Joint R and D on High Energy Density Sciences using High Power Laser

International Nuclear Information System (INIS)

Kim, Cheol Jung; Nam, S. M.; Park, S. K.; Rhee, Y. J.; Lim, C. H.

2009-02-01

As to the high energy pico-second Peta Watt laser technology for fast ignition, the design of front-end and pre/main amplifier were pursued and the OPCPA technology to increase the aspect ratio by reducing the pre-pulse were developed. Furthermore, the tiled-grating technology to replace a large grating were obtained. As to the fast electron generation and propagation, a solid target was used to generate MeV class electron with TW femto-second laser and a gas cluster was also used to generate MeV class electron with PW femto-second laser at SIOM

High-energy terahertz wave parametric oscillator with a surface-emitted ring-cavity configuration.

Science.gov (United States)

Yang, Zhen; Wang, Yuye; Xu, Degang; Xu, Wentao; Duan, Pan; Yan, Chao; Tang, Longhuang; Yao, Jianquan

2016-05-15

A surface-emitted ring-cavity terahertz (THz) wave parametric oscillator has been demonstrated for high-energy THz output and fast frequency tuning in a wide frequency range. Through the special optical design with a galvano-optical scanner and four-mirror ring-cavity structure, the maximum THz wave output energy of 12.9 μJ/pulse is achieved at 1.359 THz under the pump energy of 172.8 mJ. The fast THz frequency tuning in the range of 0.7-2.8 THz can be accessed with the step response of 600 μs. Moreover, the maximum THz wave output energy from this configuration is 3.29 times as large as that obtained from the conventional surface-emitted THz wave parametric oscillator with the same experimental conditions.

Fast neutron radiography using photoluminescent imaging plates

International Nuclear Information System (INIS)

Rant, J.; Kristof, E.; Balasko, M.; Stade, J.

1999-01-01

Fast neutron radiography (FNR) and resonance neutron radiography (RNR) are complementary to the conventional radiography with high energy gamma-rays or brems-strahlung radiation used for the inspection of thick metal objects. In both non-destructive methods, the contrast sensitivity and the penetration power can be improved by using higher energy neutrons. At present direct techniques based either n Solid State Nuclear Track detectors (SSNTDs) or scintillating screens and transfer techniques using activation threshold detectors and radiographic films are applied for the detection of fast neutron images. Rather low detection sensitivity of film and SSNTD based fast neutron imaging methods and also rather poor inherent image contrast of SSNTD pose a problem for FNR in the fast neutron energy region 1-15 MeV interesting for NDT. For more efficient detection of fast neutron images the use of novel highly sensitive photoluminescent imaging plates (IP) in combination with threshold at the KFKI research reactor. The conventional IP produced by FUJI Photo Film Co. for the detection of beta and X-ray radiation were used. The threshold activation detectors were the reactions 115 In(n, n') 115m In, 64 Zn(n,p) 64 Cu, 56 Fe(n, p) 56 Mn, 24 Mg(n, p) 24 Na and 27 Al(n, α) 24 Na. These threshold reactions cover the fast neutron energy region between 0,7 MeV and 12 MeV. Pure, commercially available metals 0,1 mm to 0,25 mm thick made of In, Zn, Fe, Mg and Al were used as converter screens. The very high sensitivity of IP, the linearity of their response over 5 decades of exposure dose and the high dynamic digitalisation latitude enabled fast neutron radiography of image quality comparable to the quality of thermal NR. In our experimental conditions (φ n ∼ 10 8 n/cm 2 s, R Cd ∼ 2) the neutron exposure and IP exposure periods were still practical and comparable to the half life of the corresponding reaction products (half an hour to several hours). Even with the 27 Al(n.α) 24

Fast Calorimeter Simulation in ATLAS

CERN Document Server

Schaarschmidt, Jana; The ATLAS collaboration

2017-01-01

Producing the very large samples of simulated events required by many physics and performance studies with the ATLAS detector using the full GEANT4 detector simulation is highly CPU intensive. Fast simulation tools are a useful way of reducing CPU requirements when detailed detector simulations are not needed. During the LHC Run-1, a fast calorimeter simulation (FastCaloSim) was successfully used in ATLAS. FastCaloSim provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitization and reconstruction software, and it can be tuned to data more easily than GEANT4. It is 500 times faster than full simulation in the calorimeter system. Now an improved version of FastCaloSim is in development, incorporating the experience with the version used during Run-1. The new FastCaloSim makes use of mach...

Reliability of hunger-related assessments during 24-hour fasts and their relationship to body composition and subsequent energy compensation.

Science.gov (United States)

Tinsley, Grant M; Moore, M Lane; Graybeal, Austin J

2018-05-01

Many diets employ regular periods of fasting that extend beyond a typical overnight fast (i.e. intermittent fasting [IF]). Evaluation of acute fasting responses provides information concerning the potential theoretical rationale for IF. The purpose of the present investigation was to assess the test-retest reliability of hunger-related variables during 24-hour fasts and the relationship between these variables and body composition, as well as subsequent energy intake (EI) after fasting. Eleven participants (6 F, 5 M) completed two 24-hour fasts after being provided a 3-day standardized weight-maintenance diet. From 16 to 24 h of fasting, participants were directly observed and provided hourly assessments of hunger, desire to eat (DTE), prospective food consumption (PFC), fullness and energy. After the fast, participants were allowed ad libitum food consumption, and compensation was calculated as EI relative to weight-maintenance energy needs. Test-retest reliability for hunger-related assessments at particular durations of fasting was evaluated using intraclass correlation coefficients (ICC), changes in dependent variables were evaluated using ANOVA with repeated measures, and relationships between variables were explored using bivariate correlations. At 16 h of fasting, the ICCs for all hunger-related assessments were statistically significant (r = 0.67-0.91; p ≤ 0.05). However, as the fast progressed, reliability varied substantially. When averaged across the nine measurements, the ICCs were: 0.81 (fullness), 0.74 (PFC), 0.67 (energy), 0.44 (DTE) and 0.36 (hunger). Body fat percentage was significantly correlated with changes in PFC (r = 0.62, p = 0.04), hunger (r = 0.66, p = 0.03), DTE (r = 0.71, p = 0.02), and fullness (r = -0.63, p = 0.04), but not energy (r = -0.16, p = 0.64). Average EI compensation was only 60% of weight-maintenance needs, but substantial variability was observed (7 to 110

Fast reactors as a solution for future small-scale nuclear energy

International Nuclear Information System (INIS)

Kudryavtseva, A.; Danilenko, K.; Dorofeev, K.

2013-01-01

Small nuclear power plants can provide a future platform for decentralized energy supply providing better levels of accessibility, safety and environmental friendliness. The optimal solution for SMR deployment is fast reactors with inherent safety. To compete alternative solutions SMRs must exhibit some evident advantages in: safety, technology, and economic. Small modular reactors with lead-bismuth coolant (SVBR-100) under development in Russia can be a prospective solution for future small and decentralized energy

High energy neutrinos from gamma-ray bursts with precursor supernovae.

Science.gov (United States)

Razzaque, Soebur; Mészáros, Peter; Waxman, Eli

2003-06-20

The high energy neutrino signature from proton-proton and photo-meson interactions in a supernova remnant shell ejected prior to a gamma-ray burst provides a test for the precursor supernova, or supranova, model of gamma-ray bursts. Protons in the supernova remnant shell and photons entrapped from a supernova explosion or a pulsar wind from a fast-rotating neutron star remnant provide ample targets for protons escaping the internal shocks of the gamma-ray burst to interact and produce high energy neutrinos. We calculate the expected neutrino fluxes, which can be detected by current and future experiments.

Fast-ion Dα measurements of the fast-ion distribution (invited)

International Nuclear Information System (INIS)

Heidbrink, W. W.

2010-01-01

The fast-ion Dα (FIDA) diagnostic is an application of charge-exchange recombination spectroscopy. Fast ions that neutralize in an injected neutral beam emit Balmer-α light with a large Doppler shift. The spectral shift is exploited to distinguish the FIDA emission from other bright sources of Dα light. Background subtraction is the main technical challenge. A spectroscopic diagnostic typically achieves temporal, energy, and transverse spatial resolution of ∼1 ms, ∼10 keV, and ∼2 cm, respectively. Installations that use narrow-band filters achieve high spatial and temporal resolution at the expense of spectral information. For high temporal resolution, the bandpass-filtered light goes directly to a photomultiplier, allowing detection of ∼50 kHz oscillations in FIDA signal. For two-dimensional spatial profiles, the bandpass-filtered light goes to a charge-coupled device camera; detailed images of fast-ion redistribution at instabilities are obtained. Qualitative and quantitative models relate the measured FIDA signals to the fast-ion distribution function. The first quantitative comparisons between theory and experiment found excellent agreement in beam-heated magnetohydrodynamics (MHD)-quiescent plasmas. FIDA diagnostics are now in operation at magnetic-fusion facilities worldwide. They are used to study fast-ion acceleration by ion cyclotron heating, to detect fast-ion transport by MHD modes and microturbulence, and to study fast-ion driven instabilities.

The new ATLAS Fast Calorimeter Simulation

CERN Document Server

Hasib, Ahmed; The ATLAS collaboration

2017-01-01

Producing the very large samples of simulated events required by many physics and performance studies with the ATLAS detector using the full GEANT4 detector simulation is highly CPU intensive. Fast simulation tools are a useful way of reducing CPU requirements when detailed detector simulations are not needed. During the LHC Run-1, a fast calorimeter simulation (FastCaloSim) was successfully used in ATLAS. FastCaloSim provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitization and reconstruction software, and it can be tuned to data more easily than GEANT4. Now an improved version of FastCaloSim is in development, incorporating the experience with the version used during Run-1. The new FastCaloSim makes use of statistical techniques such as principal component analysis, and a neural n...

The New ATLAS Fast Calorimeter Simulation

CERN Document Server

Heath, Matthew Peter; The ATLAS collaboration

2017-01-01

Producing the large samples of simulated events required by many physics and performance studies with the ATLAS detector using the full GEANT4 detector simulation is highly CPU intensive. Fast simulation tools are a useful way of reducing the CPU requirements when detailed detector simulations are not needed. During Run-1 of the LHC, a fast calorimeter simulation (FastCaloSim) was successfully used in ATLAS. FastCaloSim provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitisation and reconstruction software, and it can be tuned to data more easily than Geant4. Now an improved version of FastCaloSim is in development, incorporating the experience with the version used during Run-1. The new FastCaloSim aims to overcome some limitations of the first version by improving the description of...

Measurement and calculation of fast neutron flux in a zero-energy reactor

International Nuclear Information System (INIS)

Day, D.H.; Fox, W.N.; Hyder, H.R.

1963-05-01

An activation technique for measuring relative fast neutron fluxes is described which has some advantages over the normal method using U238 fission. The technique is based on the formation of Rh 103 after inelastic scattering of neutrons above 100 keV in energy. This isomer decays with a 57.4 minute half-life giving an easily measurable γ-activity. The energy dependence of the inelastic scattering cross-section of Rh 103 is similar to that of the fission cross-section of U 238 thus making the results of direct relevance to reactor calculations. Using the Rh 103 activation technique, measurements have been made of the fast neutron flux distribution in a typical pressure tube heavy water lattice and are compared in this report with theoretical calculations using the MONTE CARLO method. (author)

Experimental study of fast electron transport in the framework of fast ignition for inertial fusion

International Nuclear Information System (INIS)

Vauzour, B.

2012-01-01

The framework of this PhD thesis is the validation of the fast ignition scheme for the nuclear fusion by inertial confinement. It consists in the experimental study of the various processes involved in fast electron beams propagation, produced by intense laser pulses (10 19 W.cm -2 ), through dense matter either solid or compressed. In this work we present the results of three experiments carried out on different laser facilities in order to generate fast electron beams in various conditions and study their propagation in different states of matter, from the cold solid to the warm and dense plasma.The first experiment was performed with a high intensity contrast on the UHI100 laser facility (CEA Saclay). The study of fast electron energy deposition inside thin aluminium targets highlights a strong target heating at shallow depths, where the collective effects are predominant, thus producing a steep temperature profile between front (300 eV) and rear (20 eV) sides over 20μm thickness. A numerical simulation of the experiment shows that this temperature gradient induces the formation of a shock wave, breaking through the rear side of the target and thus leading to increase the thermal emission. The experimental chronometry of the shock breakthrough allowed validating the model of the collective transport of electrons.Two other experiments were dedicated to the study of fast electron beam propagation inside compressed targets. In the first experiment on the LULI2000 laser facility, the plane compression geometry allowed to precisely dissociate the energy losses due to resistive effects from those due to the collisional ones. By comparing our experimental results with simulations, we observed a significative increase of the fast electron beam energy losses with the compression and the target heating to temperatures close to the Fermi temperature. The second experiment, performed in a cylindrical geometry, demonstrated a fast electron beam guiding phenomenon due to

Density and energy distribution of epithermal secondary electrons in a plasma with fast charged particles

International Nuclear Information System (INIS)

Jayakumar, R.; Fleischmann, H.H.

1989-01-01

The production of intermediate energy secondary electrons in plasmas through collisions with fast charged particles is investigated. The density and the distribution of the secondary electrons are obtained by calculating the generation, slow down and diffusion rates, using basic Rutherford collision cross sections. It is shown that the total density of secondaries is much smaller than the fast particle density and that the energy distribution has roughly a 1/√E dependence. The higher generation secondary populations are also obtained. (orig.)

Live cell imaging combined with high-energy single-ion microbeam

Energy Technology Data Exchange (ETDEWEB)

Guo, Na; Du, Guanghua, E-mail: gh-du@impcas.ac.cn; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Guo, Jinlong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Northwest Normal University, Lanzhou (China); Chen, Hao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Institute of Nuclear Science and Technology, University of Lanzhou, Lanzhou (China)

2016-03-15

DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10{sup −3} s{sup −1} and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10{sup −2} s{sup −1}.

Live cell imaging combined with high-energy single-ion microbeam

International Nuclear Information System (INIS)

Guo, Na; Du, Guanghua; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe; Guo, Jinlong; Chen, Hao

2016-01-01

DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10"−"3 s"−"1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10"−"2 s"−"1.

Changes in energy metabolism in response to 48 h of overfeeding and fasting in Caucasians and Pima Indians

DEFF Research Database (Denmark)

Weyer, C; Vozarova, B; Ravussin, E

2001-01-01

Differences in the metabolic response to overfeeding and starvation may confer susceptibility or resistance to obesity in humans. To further examine this hypothesis, we assessed the changes in 24 h energy metabolism in response to short-term overfeeding and fasting in Caucasians (C) and Pima...... Indians (I), a population with a very high propensity for obesity....

Ion induced high energy electron emission from copper

International Nuclear Information System (INIS)

Ruano, G.; Ferron, J.

2008-01-01

We present measurements of secondary electron emission from Cu induced by low energy bombardment (1-5 keV) of noble gas (He + , Ne + and Ar + ) and Li + ions. We identify different potential and kinetic mechanisms and find the presence of high energetic secondary electrons for a couple of ion-target combinations. In order to understand the presence of these fast electrons we need to consider the Fermi shuttle mechanism and the different ion neutralization efficiencies.

Fast-shock ignition: a new approach to inertial confinement fusion

Directory of Open Access Journals (Sweden)

AH Farahbod

2013-03-01

Full Text Available  A new concept for inertial confinement fusion called fast-shock ignition (FSI is introduced as a credible scheme in order to obtain high target gain. In the proposed model, the separation of fuel ignition into two successive steps, under the suitable conditions, reduces required ignitor energy for the fuel ignition. The main procedure in FSI concept is compressing the fuel up to stagnation. Then, two high intensity short pulse laser spikes with energy and power lower than those required for shock ignition (SI and fast ignition (FI with a proper delay time are launched at the fuel which increases the central hot-spot temperature and completes the ignition of the precompressed fuel. The introduced semi-analytical model indicates that with fast-shock ignition, the total required energy for compressing and igniting the fuel can be slightly reduced in comparison to pure shock ignition. Furthermore, for fuel mass greater than , the target energy gain increases up to 15 percent and the contribution of fast ignitor under the proper conditions could be decreased about 20 percent compared with pure fast ignition. The FSI scheme is beneficial from technological considerations for the construction of short pulse high power laser drivers. The general advantages of fast-shock ignition over pure shock ignition in terms of figure of merit can be more than 1.3.

Explosive magnetic flux compression plate generators as fast high-energy power sources

International Nuclear Information System (INIS)

Caird, R.S.; Erickson, D.J.; Garn, W.B.; Fowler, C.M.

1976-01-01

A type of explosive driven generator, called a plate generator, is described. It is capable of delivering electrical energies in the MJ range at TW power levels. Plane wave detonated explosive systems accelerate two large-area metal plates to high opposing velocities. An initial magnetic field is compressed and the flux transferred to an external load. The characteristics of the plate generator are described and compared with those of other types of generators. Methods of load matching are discussed. The results of several high-power experiments are also given

Contemporary energy storage sources. Energy saving

International Nuclear Information System (INIS)

Manev, Veselin

2011-01-01

The development of renewable energy system for electricity production is impede because of needs to be stabilized with nearly equivalent installed power of energy storage devices. The development of more electrical energy storage facilities will be extremely important for electricity generation in the future. Using hydro pumping, combined with a long life and fast charge/discharge rate, highly efficient contemporary power energy storage as Altairnano lithium ion battery, currently is seems to be the best solution for fast penetration rate of wind and solar energy systems

Fast electron transport in shaped solid targets

International Nuclear Information System (INIS)

Anle Lei; Cao, L.H.; He, X.T.; Zhang, W.Y.; Tanaka, K.A.; Kodama, R.; Mima, K.; Nakamura, T.; Normatsu, T.; Yu, W.

2010-01-01

Complete text of publication follows. The scheme of fast ignition fusion energy relies on the ultra-intense ultra-short (UIUS) laser energy transport into the compressed core plasma. One solution is to insert a hollow cone in the fuel shell to block the UIUS laser from the coronal plasma, thus allowing it to reach the core plasma. The cone not only can guide the UIUS laser to its tip, but can play important roles in the specific cone-in-shell target designed for FI. It was found in a PIC simulation that the cone can guide the fast electrons generated at the inner wall to propagate along the wall surface toward its tip, which would increase the energy density at the tip and might enhance the heating of the core plasma. Surface guiding of fast electrons with planar foil targets has been demonstrated experimentally. However, the guided fast electrons will mix the electrons generated ahead by the laser light with a planar target, and hence one cannot experimentally quantitatively validate the guide of the fast electrons. We investigate the cone guiding of fast electrons with an inverse cone target. We found a novel surface current of fast electrons propagating along the cone wall. The fast electrons generated at the planar outer tip of the inverse cone are guided and confined to propagate along the inverse cone wall to form a surface current by induced transient electric and magnetic fields associated with the current itself. Once departing from the source at the outer tip, this surface current of fast electrons is 'clean', neither experiencing the interacting laser light nor mixing fast electrons ahead, unlike those in cone or planar targets. This surface current in the inverse cone may explicitly give the capability of the guide of fast electron energy by the cone wall. The guiding and confinement of fast electrons is of important for fast ignition in inertial confinement fusion and several applications in high energy density science.

Design of a 10 MJ fast discharging homopolar machine

International Nuclear Information System (INIS)

Stillwagon, R.E.; Thullen, P.

1977-01-01

The design of a fast discharging homopolar machine is described. The machine capacity is 10 MJ with a 30 ms energy delivery time. The salient features of the machine are relatively high terminal voltage, fast discharge time, high power density and high efficiency. The machine integrates several new technologies including high surface speeds, large superconducting magnets and current collection at high density

Measurement of high-energy electrons by means of a Cherenkov detector in ISTTOK tokamak

Energy Technology Data Exchange (ETDEWEB)

Jakubowski, L., E-mail: lech.Jjakubowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal); Malinowski, K.; Sadowski, M.J.; Rabinski, M. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal)

2010-10-15

The paper concerns detectors of the Cherenkov radiation which can be used to measure high-energy electrons escaping from short-living plasma. Such detectors have high temporal (about 1 ns) and spatial (about 1 mm) resolution. The paper describes a Cherenkov-type detector which was designed, manufactured and installed in the ISTTOK tokamak in order to measure fast runaway electrons. The radiator of that detector was made of an aluminium nitride (AlN) tablet with a light-tight filter on its front surface. Cherenkov signals from the radiator were transmitted through an optical cable to a fast photomultiplier. It made possible to perform direct measurements of the runaway electrons of energy above 80 keV. The measured energy values and spatial characteristics of the recorded electrons appeared to be consistent with results of numerical modelling of the runaway electron generation process in the ISTTOK tokamak.

Fast and Precise Beam Energy Measurement using Compton Backscattering at e+e- Colliders

CERN Document Server

Kaminskiy, V V; Muchnoi, N Yu; Zhilich, V N

2017-01-01

The report describes a method for a fast and precise beam energy measurement in the beam energy range 0.5-2 GeV and its application at various e+e- colliders. Low-energy laser photons interact head-on with the electron or positron beam and produce Compton backscattered photons whose energy is precisely measured by HPGe detector. The method allows measuring the beam energy with relative accuracy of ∼2-5.10-5. The method was successfully applied at VEPP-4M, VEPP-3, VEPP-2000 (BINP, Russia) and BEPC-II (IHEP, China).

Core design of a high breeding fast reactor cooled by supercritical pressure light water

Energy Technology Data Exchange (ETDEWEB)

Someya, Takayuki, E-mail: russell@ruri.waseda.jp; Yamaji, Akifumi

2016-01-15

Highlights: • Core design concept of supercritical light water cooled fast breeding reactor is developed. • Compound system doubling time (CSDT) is applied for considering an appropriate target of breeding performance. • Breeding performance is improved by reducing fuel rod diameter of the seed assembly. • Core pressure loss is reduced by enlarging the coolant channel area of the seed assembly. - Abstract: A high breeding fast reactor core concept, cooled by supercritical pressure light water has been developed with fully-coupled neutronics and thermal-hydraulics core calculations, which takes into account the influence of core pressure loss to the core neutronics characteristics. Design target of the breeding performance has been determined to be compound system doubling time (CSDT) of less than 50 years, by referring to the relationship of energy consumption and economic growth rate of advanced countries such as the G7 member countries. Based on the past design study of supercritical water cooled fast breeder reactor (Super FBR) with the concept of tightly packed fuel assembly (TPFA), further improvement of breeding performance and reduction of core pressure loss are investigated by considering different fuel rod diameters and coolant channel geometries. The sensitivities of CSDT and the core pressure loss with respect to major core design parameters have been clarified. The developed Super FBR design concept achieves fissile plutonium surviving ratio (FPSR) of 1.028, compound system doubling time (CSDT) of 38 years and pressure loss of 1.02 MPa with positive density reactivity (negative void reactivity). The short CSDT indicates high breeding performance, which may enable installation of the reactors at a rate comparable to energy growth rate of developed countries such as G7 member countries.

Ion induced high energy electron emission from copper

Energy Technology Data Exchange (ETDEWEB)

Ruano, G. [Instituto de Desarrollo Tecnologico para la Industria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina)], E-mail: gdruano@ceride.gov.ar; Ferron, J. [Instituto de Desarrollo Tecnologico para la Industria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina); Departamento de Ingenieria de Materiales, Facultad de Ingenieria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina)

2008-11-15

We present measurements of secondary electron emission from Cu induced by low energy bombardment (1-5 keV) of noble gas (He{sup +}, Ne{sup +} and Ar{sup +}) and Li{sup +} ions. We identify different potential and kinetic mechanisms and find the presence of high energetic secondary electrons for a couple of ion-target combinations. In order to understand the presence of these fast electrons we need to consider the Fermi shuttle mechanism and the different ion neutralization efficiencies.

SMEs in Energy: Are they the parallel fast track for electrification of Africa?

Energy Technology Data Exchange (ETDEWEB)

Abdel-Rahman, Mohamed

2010-09-15

The African continent is suffering from a chronic energy shortage that hiders its development. The conventional wisdom is to put the Mega projects under focus. However, a parallel fast track for the energy as an SME business may bring faster results to the continent. To that end, this paper presents proposed steps to promote the concept within the continent.

Using the fast fourier transform in binding free energy calculations.

Science.gov (United States)

Nguyen, Trung Hai; Zhou, Huan-Xiang; Minh, David D L

2018-04-30

According to implicit ligand theory, the standard binding free energy is an exponential average of the binding potential of mean force (BPMF), an exponential average of the interaction energy between the unbound ligand ensemble and a rigid receptor. Here, we use the fast Fourier transform (FFT) to efficiently evaluate BPMFs by calculating interaction energies when rigid ligand configurations from the unbound ensemble are discretely translated across rigid receptor conformations. Results for standard binding free energies between T4 lysozyme and 141 small organic molecules are in good agreement with previous alchemical calculations based on (1) a flexible complex ( R≈0.9 for 24 systems) and (2) flexible ligand with multiple rigid receptor configurations ( R≈0.8 for 141 systems). While the FFT is routinely used for molecular docking, to our knowledge this is the first time that the algorithm has been used for rigorous binding free energy calculations. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

High energy multi-cycle terahertz generation

International Nuclear Information System (INIS)

Ahr, Frederike Beate

2017-10-01

Development of compact electron accelerators and free-electron lasers requires novel acceleration schemes at shorter driving wavelengths. The Axsis project seeks to develop terahertz based electron acceleration as well as the high energy terahertz sources required. This thesis explores the methods and optical material required for the generation of highenergy multi-cycle terahertz pulses. Two experimental concepts to generate high energy terahertz radiation are presented. In addition the theoretical background and the optical properties of pertinent optical materials in the terahertz range are discussed. Investigations of the materials are performed with a terahertz time domain spectrometer and a Fourier transform infrared spectrometer. The nonlinear optical crystal lithium niobate as well as other crystals suitable for the terahertz generation and in addition polymers and other radiation attenuators are characterized in the range from 0.2 to 1 THz. The theory describing the generation of narrowband terahertz radiation is evaluated. The experimental setups to generate terahertz radiation and to characterize its properties are described. The specific crystals - periodically poled lithium niobate (PPLN) - used in the experiments to generate the multi-cycle terahertz radiation are examined to determine e.g. the poling period. The first experimental concept splits the ultra fast, broadband pump pulses into a pulse train in order to pump the PPLN at a higher fluence while increasing the damage limit. The measurements confirm that a pulse train of ultra short, broadband pump pulses increases not only the terahertz energy but also the energy conversion efficiency. The second experimental concept utilizes chirped and delayed infrared laser pulses. This pulse format makes it possible to pump the crystal with high energy pulses resulting in high energy terahertz radiation. The concept is optimized to reach energies up to 127 μJ exceeding the existing results of narrowband

High energy multi-cycle terahertz generation

Energy Technology Data Exchange (ETDEWEB)

Ahr, Frederike Beate

2017-10-15

Development of compact electron accelerators and free-electron lasers requires novel acceleration schemes at shorter driving wavelengths. The Axsis project seeks to develop terahertz based electron acceleration as well as the high energy terahertz sources required. This thesis explores the methods and optical material required for the generation of highenergy multi-cycle terahertz pulses. Two experimental concepts to generate high energy terahertz radiation are presented. In addition the theoretical background and the optical properties of pertinent optical materials in the terahertz range are discussed. Investigations of the materials are performed with a terahertz time domain spectrometer and a Fourier transform infrared spectrometer. The nonlinear optical crystal lithium niobate as well as other crystals suitable for the terahertz generation and in addition polymers and other radiation attenuators are characterized in the range from 0.2 to 1 THz. The theory describing the generation of narrowband terahertz radiation is evaluated. The experimental setups to generate terahertz radiation and to characterize its properties are described. The specific crystals - periodically poled lithium niobate (PPLN) - used in the experiments to generate the multi-cycle terahertz radiation are examined to determine e.g. the poling period. The first experimental concept splits the ultra fast, broadband pump pulses into a pulse train in order to pump the PPLN at a higher fluence while increasing the damage limit. The measurements confirm that a pulse train of ultra short, broadband pump pulses increases not only the terahertz energy but also the energy conversion efficiency. The second experimental concept utilizes chirped and delayed infrared laser pulses. This pulse format makes it possible to pump the crystal with high energy pulses resulting in high energy terahertz radiation. The concept is optimized to reach energies up to 127 μJ exceeding the existing results of narrowband

Fast damping in mismatched high intensity beam transportation

Directory of Open Access Journals (Sweden)

V. Variale

2001-08-01

Full Text Available A very fast damping of beam envelope oscillation amplitudes was recently observed in simulations of high intensity beam transport, through periodic FODO cells, in mismatched conditions [V. Variale, Nuovo Cimento Soc. Ital. Fis. 112A, 1571–1582 (1999 and T. Clauser et al., in Proceedings of the Particle Accelerator Conference, New York, 1999 (IEEE, Piscataway, NJ, 1999, p. 1779]. A Landau damping mechanism was proposed at the origin of observed effect. In this paper, to further investigate the source of this fast damping, extensive simulations have been carried out. The results presented here support the interpretation of the mechanism at the origin of the fast damping as a Landau damping effect.

Fast feedback system for energy and beam stabilization

International Nuclear Information System (INIS)

R. Dickson; V. Lebedev

1999-01-01

The electron beams being delivered to targets of the Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Accelerator Facility (Jefferson Lab) are plagued with undesirable positional and energy fluctuations. These fluctuations primarily occur at harmonics of the power line frequency (60, 120, 180, etc. hertz), and their cause is rooted in electromagnetic fields generated by accelerator electronic equipment. It is possible to largely nullify these deviations by applying real time corrections to electromagnets and RF verniers along the beam line. This concept has been successfully applied at Jefferson Lab by extensively modifying the existing Beam Position Monitor (BPM) system with the integration of an algorithm that computes correction signals targeted at the power line harmonics. Many of the modifications required were due to the existing CEBAF BPM system not having the data acquisition bandwidth needed for this type of feedback system. This paper will describe the techniques required to transform the CEBAF standard BPM system into a high speed practical fast feedback system that coexists with the large scale control system--the Experimental Physics and Industrial Control System (EPICS)--that runs the CEBAF accelerator in daily operation

The Integral Fast Reactor concept: Today's hope for tomorrow's electrical energy needs

International Nuclear Information System (INIS)

Dwight, C.C.; Phipps, R.D.

1989-01-01

Acid rain and the greenhouse effect are getting more attention as their impacts on the environment become evident around the world. Substantial evidence indicates that fossil fuel combustion for electrical energy production activities is a key cause of those problems. A change in electrical energy production policy is essential to a stable, healthy environment. That change is inevitable, it's just a matter of when and at what cost. Vision now, instead of reaction later, both in technological development and public perception, will help to limit the costs of change. The Integral Fast Reactor (IFR) is a visionary concept developed by Argonne National Laboratory that involves electrical energy production through fissioning of heavy metals by fast neutrons in a reactor cooled by liquid sodium. Physical characteristics of the coolant and fuel give the reactor impressive characteristics of inherent and passive safety. Spent fuel is pyrochemically reprocessed and returned to the reactor in the IFR's closed fuel cycle. Advantages in waste management are realized, and the reactor has the potential for breeding, i.e., producing as much or more fuel than it uses. This paper describes the IFR concept and shows how it is today's hope for tomorrow's electrical energy needs. 14 refs., 1 fig., 1 tab

''FASTBUS'': status of development of a standard high speed data acquisition bus for high energy physics

International Nuclear Information System (INIS)

Larsen, R.S.

1977-11-01

In late 1975 the US NIM Committee initiated a study group, known as the Advanced System Study Group, to review the future data acquisition modular interface requirements for high-energy physics. The final report of this group recommended the development of a new standard system, now known as ''FASTBUS,'' which would have as principal features improved speed by a factor of 10 over CAMAC, more generalized architecture to accommodate distributed parallel processing and fast preprocessing, special scan modes of particular use in high-energy particle detection systems, and standardized bus structures and mechanics. A brief summary of current activity is given. 7 figures, 3 tables

Scaling of energy deposition in fast ignition targets

International Nuclear Information System (INIS)

Welch, Dale R.; Slutz, Stephen A.; Mehlhorn, Thomas Alan; Campbell, Robert B.

2005-01-01

We examine the scaling to ignition of the energy deposition of laser generated electrons in compressed fast ignition cores. Relevant cores have densities of several hundred g/cm 3 , with a few keV initial temperature. As the laser intensities increase approaching ignition systems, on the order of a few 10 21 W/cm 2 , the hot electron energies expected to approach 100MeV. Most certainly anomalous processes must play a role in the energy transfer, but the exact nature of these processes, as well as a practical way to model them, remain open issues. Traditional PIC explicit methods are limited to low densities on current and anticipated computing platforms, so the study of relevant parameter ranges has received so far little attention. We use LSP to examine a relativistic electron beam (presumed generated from a laser plasma interaction) of legislated energy and angular distribution is injected into a 3D block of compressed DT. Collective effects will determine the stopping, most likely driven by magnetic field filamentation. The scaling of the stopping as a function of block density and temperature, as well as hot electron current and laser intensity is presented. Sub-grid models may be profitably used and degenerate effects included in the solution of this problem.

Measurements of Relative Biological Effectiveness and Oxygen Enhancement Ratio of Fast Neutrons of Different Energies

Energy Technology Data Exchange (ETDEWEB)

Barendsen, G. W.; Broerse, J. J. [Radiobiological Institute of the Health Research Council TNO, Rijswijk (ZH) (Netherlands)

1968-03-15

Impairment of the reproductive capacity of cultured cells of human kidney origin (T-l{sub g} cells) has been measured by the Puck cloning technique. From the dose-survival curves obtained in these experiments by irradiation of cells in equilibrium with air and nitrogen, respectively, the relative biological effectiveness (RBE) and the oxygen enhancement ratios (OER) were determined for different beams of fast neutrons. Monoenergetic neutrons of 3 and 15 MeV energy, fission spectrum fast neutrons (mean energy about 1.5 MeV), neutrons produced by bombarding Be with cyclotron-accelerated 16 MeV deuterons (mean energy about 6 MeV) and neutrons produced by bombarding Be with cyclotron- accelerated 20 MeV {sup 3}He ions (mean energy about 10 MeV) have been compared with 250 kVp X-rays as a standard reference. The RBE for 50% cell survival varies from 4.7 for fission-spectrum fast neutrons to 2.7 for 15 MeV monoenergetic neutrons. The OER is not strongly dependent on the neutron energy for the various beams investigated. For the neutrons with the highest and lowest energies used OER values of 1.6 {+-} 0.2 and 1.5 {+-} 0.1 were measured. An interpretation of these data on the basis of the shapes of the LET spectra is proposed and an approximate verification of this hypothesis is provided from measurements in which secondary particle equilibrium was either provided for or deliberately eliminated. (author)

Preliminary investigations of Monte Carlo Simulations of neutron energy and LET spectra for fast neutron therapy facilities

International Nuclear Information System (INIS)

Kroc, T.K.

2009-01-01

No fast neutron therapy facility has been built with optimized beam quality based on a thorough understanding of the neutron spectrum and its resulting biological effectiveness. A study has been initiated to provide the information necessary for such an optimization. Monte Carlo studies will be used to simulate neutron energy spectra and LET spectra. These studies will be bench-marked with data taken at existing fast neutron therapy facilities. Results will also be compared with radiobiological studies to further support beam quality ptimization. These simulations, anchored by this data, will then be used to determine what parameters might be optimized to take full advantage of the unique LET properties of fast neutron beams. This paper will present preliminary work in generating energy and LET spectra for the Fermilab fast neutron therapy facility.

The energy demand of fast neuronal network oscillations: insights from brain slice preparations

Directory of Open Access Journals (Sweden)

Oliver eKann

2012-01-01

Full Text Available Fast neuronal network oscillations in the gamma range (30-100 Hz in the cerebral cortex have been implicated in higher cognitive functions such as sensual perception, working memory, and, perhaps, consciousness. However, little is known about the energy demand of gamma oscillations. This is mainly caused by technical limitations that are associated with simultaneous recordings of neuronal activity and energy metabolism in small neuronal networks and at the level of mitochondria in vivo. Thus recent studies have focused on brain slice preparations to address the energy demand of gamma oscillations in vitro. Here, reports will be summarized and discussed that combined electrophysiological recordings, oxygen sensor microelectrodes and live-cell fluorescence imaging in acutely prepared slices and organotypic slice cultures of the hippocampus from both, mouse and rat. These reports consistently show that gamma oscillations can be reliably induced in hippocampal slice preparations by different pharmacological tools. They suggest that gamma oscillations are associated with high energy demand, requiring both rapid adaptation of oxidative energy metabolism and sufficient supply with oxygen and nutrients. These findings might help to explain the exceptional vulnerability of higher cognitive functions during pathological processes of the brain, such as circulatory disturbances, genetic mitochondrial diseases, and neurodegeneration.

Ultra-high efficiency, fast graphene micro-heater on silicon

DEFF Research Database (Denmark)

Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn

2017-01-01

We demonstrate an ultra-high efficiency and fast graphene microheater on silicon photonic crystal waveguide. By taking advantage of slow-light effect, a tuning efficiency of 1.07 nm/mW and power consumption per free spectral range of 3.99 mW. A fast rise and decay times (10% to 90%) of only 750 ns...

Fast-response protection from high currents

International Nuclear Information System (INIS)

Novikov, A.A.

1989-01-01

Protection devices for power electronic equipment from shorting current are described. The device is shunted using spark gaps with minimal possible number of spark gaps to protect it. High fast-response (<100 ns) and operation voltage wide range (6-100 kV) are attained using Arkadiev-Marx generator-base trigger devices and air-core pulse transformer

Increased mitochondrial energy efficiency in skeletal muscle after long-term fasting: its relevance to animal performance.

Science.gov (United States)

Bourguignon, Aurore; Rameau, Anaïs; Toullec, Gaëlle; Romestaing, Caroline; Roussel, Damien

2017-07-01

In the final stage of fasting, skeletal muscle mass and protein content drastically decrease when the maintenance of efficient locomotor activity becomes crucial for animals to reactivate feeding behaviour and survive a very long period of starvation. As mitochondrial metabolism represents the main physiological link between the endogenous energy store and animal performance, the aim of this study was to determine how a very long, natural period of fasting affected skeletal muscle mitochondrial bioenergetics in king penguin ( Aptenodytes patagonicus ) chicks. Rates of mitochondrial oxidative phosphorylation were measured in pectoralis permeabilized fibres and isolated mitochondria. Mitochondrial ATP synthesis efficiency and the activities of respiratory chain complexes were measured in mitochondria isolated from pectoralis muscle. Results from long-term (4-5 months) naturally fasted chicks were compared with those from short-term (10 day) fasted birds. The respiratory activities of muscle fibres and isolated mitochondria were reduced by 60% and 45%, respectively, on average in long-term fasted chicks compared with short-term fasted birds. Oxidative capacity and mitochondrial content of pectoralis muscle were lowered by long-term fasting. Bioenergetic analysis of pectoralis muscle also revealed that mitochondria were, on average, 25% more energy efficient in the final stage of fasting (4-5 months) than after 10 days of fasting (short-term fasted birds). These results suggest that the strong reduction in respiratory capacity of pectoralis muscle was partly alleviated by increased mitochondrial ATP synthesis efficiency. Such oxidative phosphorylation optimization can impact animal performance, e.g. the metabolic cost of locomotion or the foraging efficiency. © 2017. Published by The Company of Biologists Ltd.

FASTBUS system used in a high energy experiment

International Nuclear Information System (INIS)

Leipuner, L.B.; Fuhrmann, J.; Larsen, R.

1980-01-01

Experiment No. 735, now being executed at the A.G.S. is implemented in FASTBUS. Briefly, this data acquisition system is designed to operate and gather data from high energy physics experiments at sub-microsecond speeds. It is a 32 bit bus system capable of operating at near-gigabit rates. The bus can be segmented with each segment operating independently when not communicating with each other. The system is based upon a very fast integrated circuit family, emitter coupled logic or ECL

Fast-food and full-service restaurant consumption and daily energy and nutrient intakes in US adults.

Science.gov (United States)

An, R

2016-01-01

Calorie intake and diet quality are influenced by the source of food and the place of consumption. This study examines the impacts of fast-food and full-service restaurant consumption on daily energy and nutrient intakes in US adults. Nationally representative data of 18,098 adults 18 years of age and above from the National Health and Nutrition Examination Survey 2003-2010 waves were analyzed. Outcomes included daily intake of total calories and 24 nutrients of public health concern. The key predictors were any food/beverage consumption in a day from fast-food or full-service restaurant, differentiated by consumption at home versus away from home. First-difference estimator addressed confounding bias from time-invariant unobservables such as personal food/beverage preferences by using within-individual variations in diet and restaurant consumption status between two nonconsecutive 24-h dietary recalls. Fast-food and full-service restaurant consumption, respectively, were associated with a net increase in daily total energy intake of 190.29 and 186.74 kcal, total fat of 10.61 and 9.58 g, saturated fat of 3.49 and 2.46 g, cholesterol of 10.34 and 57.90 mg, and sodium of 297.47 and 411.92 mg. The impact of fast-food and full-service restaurant consumption on energy and nutrient intakes differed by sex, race/ethnicity, education, income and weight status. Increased total energy, total fat, saturated fat, cholesterol and sodium intake were substantially larger when full-service restaurant food was consumed away from home than at home. A holistic policy intervention is warranted to target the American's overall dining-out behavior rather than fast-food consumption alone.

Ultra Fast, High Rep Rate, High Voltage Spark Gap Pulser

Science.gov (United States)

1995-07-01

current rise time. The spark gap was designed to have a coaxial geometry reducing its inductance. Provisions were made to pass flowing gas between the...ULTRA FAST, HIGH REP RATE, HIGH VOLTAGE SPARK GAP PULSER Robert A. Pastore Jr., Lawrence E. Kingsley, Kevin Fonda, Erik Lenzing Electrophysics and...Modeling Branch AMSRL-PS-EA Tel.: (908)-532-0271 FAX: (908)-542-3348 U.S. Army Research Laboratory Physical Sciences Directorate Ft. Monmouth

Upgrading the Fast Calorimeter Simulation in ATLAS

CERN Document Server

Schaarschmidt, Jana; The ATLAS collaboration

2017-01-01

The tremendous need for simulated samples now and even more so in the future, encourage the development of fast simulation techniques. The Fast Calorimeter Simulation is a faster though less accurate alternative to the full calorimeter simulation with Geant4. It is based on parametrizing the longitudunal and lateral energy deposits of single particles in the ATLAS calorimeter. Principal component analysis and machine learning techniques are used to improve the performance and decrease the memory need compared to the current version of the ATLAS Fast Calorimeter Simulation. The parametrizations are expanded to cover very high energies and very forward detector regions, to increase the applicability of the tool. A prototype of this upgraded Fast Calorimeter Simulation has been developed and first validations with single particles show substantial improvements over the previous version.

High Voltage, Fast-Switching Module for Active Control of Magnetic Fields and Edge Plasma Currents

Science.gov (United States)

Ziemba, Timothy; Miller, Kenneth; Prager, James; Slobodov, Ilia

2016-10-01

Fast, reliable, real-time control of plasma is critical to the success of magnetic fusion science. High voltage and current supplies are needed to mitigate instabilities in all experiments as well as disruption events in large scale tokamaks for steady-state operation. Silicon carbide (SiC) MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities; however, these devices are limited to 1.2-1.7 kV devices. As fusion enters the long-pulse and burning plasma eras, efficiency of power switching will be important. Eagle Harbor Technologies (EHT), Inc. developing a high voltage SiC MOSFET module that operates at 10 kV. This switch module utilizes EHT gate drive technology, which has demonstrated the ability to increase SiC MOSFET switching efficiency. The module will allow more rapid development of high voltage switching power supplies at lower cost necessary for the next generation of fast plasma feedback and control. EHT is partnering with the High Beta Tokamak group at Columbia to develop detailed high voltage module specifications, to ensure that the final product meets the needs of the fusion science community.

Initial use of fast switched dual energy CT for coronary artery disease

Science.gov (United States)

Pavlicek, William; Panse, Prasad; Hara, Amy; Boltz, Thomas; Paden, Robert; Yamak, Didem; Licato, Paul; Chandra, Naveen; Okerlund, Darin; Dutta, Sandeep; Bhotika, Rahul; Langan, David

2010-04-01

Coronary CT Angiography (CTA) is limited in patients with calcified plaque and stents. CTA is unable to confidently differentiate fibrous from lipid plaque. Fast switched dual energy CTA offers certain advantages. Dual energy CTA removes calcium thereby improving visualization of the lumen and potentially providing a more accurate measure of stenosis. Dual energy CTA directly measures calcium burden (calcium hydroxyapatite) thereby eliminating a separate non-contrast series for Agatston Scoring. Using material basis pairs, the differentiation of fibrous and lipid plaques is also possible. Patency of a previously stented coronary artery is difficult to visualize with CTA due to resolution constraints and localized beam hardening artifacts. Monochromatic 70 keV or Iodine images coupled with Virtual Non-stent images lessen beam hardening artifact and blooming. Virtual removal of stainless steel stents improves assessment of in-stent re-stenosis. A beating heart phantom with 'cholesterol' and 'fibrous' phantom coronary plaques were imaged with dual energy CTA. Statistical classification methods (SVM, kNN, and LDA) distinguished 'cholesterol' from 'fibrous' phantom plaque tissue. Applying this classification method to 16 human soft plaques, a lipid 'burden' may be useful for characterizing risk of coronary disease. We also found that dual energy CTA is more sensitive to iodine contrast than conventional CTA which could improve the differentiation of myocardial infarct and ischemia on delayed acquisitions. These phantom and patient acquisitions show advantages with using fast switched dual energy CTA for coronary imaging and potentially extends the use of CT for addressing problem areas of non-invasive evaluation of coronary artery disease.

A fast and flexible reactor physics model for simulating neutron spectra and depletion in fast reactors - 202

International Nuclear Information System (INIS)

Recktenwald, G.D.; Bronk, L.A.; Deinert, M.R.

2010-01-01

Determining the time dependent concentration of isotopes within a nuclear reactor core is central to the analysis of nuclear fuel cycles. We present a fast, flexible tool for determining the time dependent neutron spectrum within fast reactors. The code (VBUDS: visualization, burnup, depletion and spectra) uses a two region, multigroup collision probability model to simulate the energy dependent neutron flux and tracks the buildup and burnout of 24 actinides, as well as fission products. While originally developed for LWR simulations, the model is shown to produce fast reactor spectra that show high degree of fidelity to available fast reactor benchmarks. (authors)

Design of fundamental building blocks for fast binary readout CMOS sensors used in high-energy physics experiments

Energy Technology Data Exchange (ETDEWEB)

Degerli, Yavuz [CEA Saclay, IRFU/SEDI, 91191 Gif-sur-Yvette Cedex (France)], E-mail: degerli@cea.fr

2009-04-21

In this paper, design details of key building blocks for fast binary readout CMOS monolithic active pixel sensors developed for charged particle detection are presented. Firstly, an all-NMOS pixel architecture with in-pixel amplification and reset noise suppression which allows fast readout is presented. This pixel achieves high charge-to-voltage conversion factors (CVF) using a few number of transistors inside the pixel. It uses a pre-amplifying stage close to the detector and a simple double sampling (DS) circuitry to store the reset level of the detector. The DS removes the offset mismatches of amplifiers and the reset noise of the detector. Offset mismatches of the source follower are also corrected by a second column-level DS stage. The second important building block of these sensors, a low-power auto-zeroed column-level discriminator, is also presented. These two blocks transform the charge of the impinging particle into binary data. Finally, some experimental results obtained on CMOS chips designed using these blocks are presented.

Variability in the reported energy, total fat and saturated fat contents in fast-food products across ten countries.

Science.gov (United States)

Ziauddeen, Nida; Fitt, Emily; Edney, Louise; Dunford, Elizabeth; Neal, Bruce; Jebb, Susan A

2015-11-01

Fast foods are often energy dense and offered in large serving sizes. Observational data have linked the consumption of fast foods to an increased risk of obesity and related diseases. We surveyed the reported energy, total fat and saturated fat contents, and serving sizes, of fast-food items from five major chains across ten countries, comparing product categories as well as specific food items available in most countries. MRC Human Nutrition Research, Cambridge, UK. Data for 2961 food and drink products were collected, with most from Canada (n 550) and fewest from the United Arab Emirates (n 106). There was considerable variability in energy and fat contents of fast foods across countries, reflecting both the portfolio of products and serving size variability. Differences in total energy between countries were particularly noted for chicken dishes (649-1197 kJ/100 g) and sandwiches (552-1050 kJ/100g). When comparing the same product between countries variations were consistently observed in total energy and fat contents (g/100 g); for example, extreme variation in McDonald's Chicken McNuggets with 12 g total fat/100 g in Germany compared with 21·1 g/100 g in New Zealand. These cross-country variations highlight the possibility for further product reformulation in many countries to reduce nutrients of concern and improve the nutritional profiles of fast-food products around the world. Standardisation of serving sizes towards the lower end of the range would also help to reduce the risk of overconsumption.

Variability in the reported energy, total fat and saturated fat content in fast food products across ten countries

Science.gov (United States)

Ziauddeen, Nida; Fitt, Emily; Edney, Louise; Dunford, Elizabeth; Neal, Bruce; Jebb, Susan A.

2016-01-01

Objective Fast foods are often energy dense and offered in large serving sizes. Observational data has linked the consumption of fast food to an increased risk of obesity and related diseases. Design We surveyed the reported energy, total fat and saturated fat contents, and serving sizes, of fast food items from five major chains across 10 countries, comparing product categories as well as specific food items available in most countries. Setting MRC Human Nutrition Research (HNR), Cambridge Subjects Data for 2961 food and drink products were collected, with most from Canada (n=550) and fewest from United Arab Emirates (n=106). Results There was considerable variability in energy and fat content of fast food across countries, reflecting both the portfolio of products, and serving size variability. Differences in total energy between countries were particularly noted for chicken dishes (649-1197kJ/100g) and sandwiches (552-1050kJ/100g). When comparing the same product between countries variations were consistently observed in total energy and fat content (g/100g) with extreme variation in McDonald’s Chicken McNuggets with 12g total fat (g/100g) in Germany compared to 21.1g in New Zealand. Conclusions These cross-country variations highlight the possibility for further product reformulation in many countries to reduce nutrients of concern and improve the nutritional profiles of fast food products around the world. Standardisation of serving sizes towards the lower end of the range would also help to reduce the risk of overconsumption. PMID:25702788

Development and applications of high energy industrial computed tomography in China

International Nuclear Information System (INIS)

Xiao, YongShun; Chen, Zhiqiang

2016-01-01

In recent years, China's rapid development of high-end equipment manufacturing industry in the high-speed railway, aircraft, carrier rocket, etc. brings the growing requirements of the high quality assurance of the product. The accelerator based high-energy X-ray Industrial CT has the advantages of strong penetrating power, high sensitivity defect detection and quantitative measurement with image visualization, can meet the needs of the large complicated structure inspection demands. This paper introduces the current research and development status of high energy industrial CT system in China. Research achievements by the Tsinghua University and the Granpect company are discussed, including the ICT system design, high-power LINAC accelerator X-ray source and high detection efficiency detector development, fast and accurate reconstruction algorithms research, etc. This paper also introduces the particularized NDT applications from dozens of industrial CT systems made by Granpect in China, including welding structure nondestructive testing, assembly quality inspection, reverse engineering, scientific research and other applications. Then the future development and application of high energy industrial CT is prospected.

Effects of buried high-Z layers on fast electron propagation

International Nuclear Information System (INIS)

Yang, Xiaohu; Zhuo, Hongbin; Ma, Yanyun; Shao, Fuqiu; Xu, Han; Yin Yan; Borghesi, M.

2014-01-01

The transport through high density plasmas of relativistic electron beams generated by ultra-intense laser-plasma interaction has potential applications in laser-driven ion acceleration and in the fast igniter scheme for inertial confinement fusion. By extending a prior model [A.R. Bell, J.R. Davies, S.M. Guerin, Phys. Rev. E 58, 2471 (1998)], the magnetic field generated during the transport of a fast electron beam driven by an ultra-intense laser in a solid target is derived analytically and applied to estimate the effect of such field on fast electron propagation through a buried high-Z layer in a lower-Z target. It is found that the effect gets weaker with the increase of the depth of the buried layer, the divergence of the fast electrons, and the laser intensity, indicating that magnetic field effects on the fast electron divergence as measured from K a X-ray emission may need to be considered for moderate laser intensities. On the basis of the calculations, some considerations are made on how one can mitigate the effect of the magnetic field generated at the interface. (authors)

The Fast-Casual Conundrum: Fast-Casual Restaurant Entrées Are Higher in Calories than Fast Food.

Science.gov (United States)

Schoffman, Danielle E; Davidson, Charis R; Hales, Sarah B; Crimarco, Anthony E; Dahl, Alicia A; Turner-McGrievy, Gabrielle M

2016-10-01

Frequently eating fast food has been associated with consuming a diet high in calories, and there is a public perception that fast-casual restaurants (eg, Chipotle) are healthier than traditional fast food (eg, McDonald's). However, research has not examined whether fast-food entrées and fast-casual entrées differ in calorie content. The purpose of this study was to determine whether the caloric content of entrées at fast-food restaurants differed from that found at fast-casual restaurants. This study was a cross-sectional analysis of secondary data. Calorie information from 2014 for lunch and dinner entrées for fast-food and fast-casual restaurants was downloaded from the MenuStat database. Mean calories per entrée between fast-food restaurants and fast-casual restaurants and the proportion of restaurant entrées that fell into different calorie ranges were assessed. A t test was conducted to test the hypothesis that there was no difference between the average calories per entrée at fast-food and fast-casual restaurants. To examine the difference in distribution of entrées in different calorie ranges between fast-food and fast-casual restaurants, χ(2) tests were used. There were 34 fast-food and 28 fast-casual restaurants included in the analysis (n=3,193 entrées). Fast-casual entrées had significantly more calories per entrée (760±301 kcal) than fast-food entrées (561±268; Prestaurants to determine whether the energy content or nutrient density of full meals (ie, entrées with sides and drinks) differs between fast-casual restaurants and fast-food restaurants. Calorie-conscious consumers should consider the calorie content of entrée items before purchase, regardless of restaurant type. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Suppression of chaos at slow variables by rapidly mixing fast dynamics through linear energy-preserving coupling

OpenAIRE

Abramov, Rafail V.

2011-01-01

Chaotic multiscale dynamical systems are common in many areas of science, one of the examples being the interaction of the low-frequency dynamics in the atmosphere with the fast turbulent weather dynamics. One of the key questions about chaotic multiscale systems is how the fast dynamics affects chaos at the slow variables, and, therefore, impacts uncertainty and predictability of the slow dynamics. Here we demonstrate that the linear slow-fast coupling with the total energy conservation prop...

Intermittent fasting protects against the deterioration of cognitive function, energy metabolism and dyslipidemia in Alzheimer's disease-induced estrogen deficient rats.

Science.gov (United States)

Shin, Bae Kun; Kang, Suna; Kim, Da Sol; Park, Sunmin

2018-02-01

Intermittent fasting may be an effective intervention to protect against age-related metabolic disturbances, although it is still controversial. Here, we investigated the effect of intermittent fasting on the deterioration of the metabolism and cognitive functions in rats with estrogen deficiency and its mechanism was also explored. Ovariectomized rats were infused with β-amyloid (25-35; Alzheimer's disease) or β-amyloid (35-25, Non-Alzheimer's disease; normal cognitive function) into the hippocampus. Each group was randomly divided into two sub-groups: one with intermittent fasting and the other fed ad libitum: Alzheimer's disease-ad libitum, Alzheimer's disease-intermittent fasting, Non-Alzheimer's disease-ad libitum, and Non-Alzheimer's disease-intermittent fasting. Rats in the intermittent fasting groups had a restriction of food consumption to a 3-h period every day. Each group included 10 rats and all rats fed a high-fat diet for four weeks. Interestingly, Alzheimer's disease increased tail skin temperature more than Non-Alzheimer's disease and intermittent fasting prevented the increase. Alzheimer's disease reduced bone mineral density in the spine and femur compared to the Non-Alzheimer's disease, whereas bone mineral density in the hip and leg was reduced by intermittent fasting. Fat mass only in the abdomen was decreased by intermittent fasting. Intermittent fasting decreased food intake without changing energy expenditure. Alzheimer's disease increased glucose oxidation, whereas intermittent fasting elevated fat oxidation as a fuel source. Alzheimer's disease and intermittent fasting deteriorated insulin resistance in the fasting state but intermittent fasting decreased serum glucose levels after oral glucose challenge by increasing insulin secretion. Alzheimer's disease deteriorated short and spatial memory function compared to the Non-Alzheimer's disease, whereas intermittent fasting prevented memory loss in comparison to ad libitum. Unexpectedly

Fast optical shutters for Nova, a high power fusion laser

International Nuclear Information System (INIS)

Bradley, L.P.; Gagnon, W.L.; Carder, B.M.

1977-01-01

Preliminary design and performance test results for fast optical shutters intended for use in the Nova high power fusion laser system are briefly described. Both an opening shutter to protect the pellet target from amplified spontaneous emission (ASE), and a closing shutter to protect the laser from light reflected back from the target are discussed. Faraday rotators, synchronized by a 400 Hz oscillator, provide an opening shutter mechanism with an opening time of approximately 10 μs. A plasma closing shutter, employing electrical sublimation of a foil, provide a shutter closing time of 70 ns +- 20 ns. Energy for foil sublimation is provided by discharge of a 42 J capacitor bank. Implementation of these shutter techniques in the Nova system is anticipated to improve laser output power and efficiency

No speed limits in medical imaging and high-energy physics

CERN Multimedia

Rita Giuffredi & Tom Meyer

2015-01-01

Speed, or high time resolution, is becoming increasingly important, if not crucial, in the high-energy physics domain, both for particle acceleration and detection systems. Medical-imaging technology also vitally depends on high time resolution detection techniques, often the offspring of today’s large particle physics experiments. The four-year FP7 Marie Curie Training Project “PicoSEC-MCNet”, which draws to a close at the end of November, was designed to develop ultra-fast photon detectors for applications in both domains. The project has achieved important results that promise to trigger further developments in the years to come.   The PicoSEC-MCNet project participants. “New requirements in high-energy physics force us to push the limits of photon detection speed, as future high-luminosity accelerators will force us to cope with the unprecedentedly short bunch crossing intervals needed to produce sufficient luminosity,” explains Tom M...

Study of non-inductive current drive using high energy neutral beam injection on JT-60U

International Nuclear Information System (INIS)

Oikawa, Toshihiro

2004-01-01

The negative ion based neutral beam (N-NB) current drive was experimentally studied. The N-NB driven current density was determined over a wide range of electron temperatures by using the motional Stark effect spectroscopy. Theoretical prediction of the NB current drive increasing with beam energy and electron temperature was validated. A record value of NB current drive efficiency 1.55 x 10 19 Am -2 W -1 was achieved simultaneously with high confinement and high beta at at a plasma current of 1.5 MA under a fully non-inductively current driven condition. The experimental validation of NB current drive theory for MHD quiescent plasmas gives greater confidence in predicting the NB current drive in future reactors. However, it was also found that MHD instabilities caused a degradation of NB current drive. A beam-driven instability expelled N-NB fast ions carrying non-inductive current from the central region. The lost N-NB driven current was estimated to be 7% of the total N-NB driven current. For the neoclassical tearing mode (NTM), comparisons of the measured neutron yield and fast ion pressure profile with transport code calculations revealed that the loss of fast ions increases with the NTM activity and that fast ions at higher energies suffer larger transport than at lower energies. (author)

Enabling fast charging - Battery thermal considerations

Science.gov (United States)

Keyser, Matthew; Pesaran, Ahmad; Li, Qibo; Santhanagopalan, Shriram; Smith, Kandler; Wood, Eric; Ahmed, Shabbir; Bloom, Ira; Dufek, Eric; Shirk, Matthew; Meintz, Andrew; Kreuzer, Cory; Michelbacher, Christopher; Burnham, Andrew; Stephens, Thomas; Francfort, James; Carlson, Barney; Zhang, Jiucai; Vijayagopal, Ram; Hardy, Keith; Dias, Fernando; Mohanpurkar, Manish; Scoffield, Don; Jansen, Andrew N.; Tanim, Tanvir; Markel, Anthony

2017-11-01

Battery thermal barriers are reviewed with regards to extreme fast charging. Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature rise of the battery during extreme fast charging. If the battery thermal management system is not designed correctly, the temperature of the cells could reach abuse temperatures and potentially send the cells into thermal runaway. Furthermore, the cell and battery interconnect design needs to be improved to meet the lifetime expectations of the consumer. Each of these aspects is explored and addressed as well as outlining where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today's market. Thermal management is not a limiting condition with regard to extreme fast charging, but many factors need to be addressed especially for future high specific energy density cells to meet U.S. Department of Energy cost and volume goals.

Fast ion loss and radial electric field in high-aspect-ratio stellarator

International Nuclear Information System (INIS)

Itoh, Kimitaka; Sanuki, Heiji; Itoh, Sanae

1992-01-01

Theoretical model is developed to determine the radial electric field and the fast ion loss simultaneously in stellarators, and is applied to the Wendelstein VII-A stellarator. The predicted value of the radial electric field is more close to experiments than the purely neoclassical calculation. The loss rate, which is determined simultaneously, is in the range of experimental observations. The partition of the injection energy by the bulk heating, direct orbit loss and shine through is estimated by using the selfconsistent electric field profile. The orbit loss becomes noticeable as the injection energy increases. The influence of the neutral particles is also studied. Neutral particles enhance the negative radial electric field, and reduce the direct orbit loss by the expense of the charge exchange loss. The impact of the increased radial electric field on the neoclassical ion thermal energy loss is compared to the direct loss of fast ions. The reduction of the neoclassical loss is much smaller than the orbit loss. (author)

Fundamentals of fast reduction of ultrafine iron ore at low temperature

Institute of Scientific and Technical Information of China (English)

Pei Zhao; Peimin Guo

2008-01-01

Fundamentals on the fast reduction of ultrafine iron ore at low temperature, including characterization of ultrafine ore, de- oxidation thermodynamics of stored-energy ultrafine ore, kinetics of iron ore deoxidation, and deoxidation mechanism, etc., and a new ironmaking process are presented in this article. Ultrafine ore concentrate with a high amount of stored energy can be produced by mechanical milling, and can be dcoxidated fast below 700℃ by either the coal-based or gas-based process. This novel process has some advantages over others: high productivity, low energy consumption, and environmental friendliness.

Energy loss and charge exchange processes of high energy heavy ions channeled in crystals

International Nuclear Information System (INIS)

Poizat, J.C.; Andriamonje, S.; Anne, R.; Faria, N.V.d.C.; Chevallier, M.; Cohen, C.; Dural, J.; Farizon-Mazuy, B.; Gaillard, M.J.; Genre, R.; Hage-Ali, M.; Kirsch, R.; L'hoir, A.; Mory, J.; Moulin, J.; Quere, Y.; Remillieux, J.; Schmaus, D.; Toulemonde, M.

1990-01-01

The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. Our experiments show that high energy heavy ion channeling deeply modifies their slowing down and charge exchange processes. This is due to the fact that channeled ions interact only with outershell target electrons, which means that the electron density they experience is very low and that the binding energy, and then the momentum distribution of these electrons, are quite different from the corresponding average values associated to random incidence. The two experimental studies presented here show the reduction of the energy loss rate for fast channeled heavy ions and illustrate the two aspects of channeling effects on charge exchange, the reduction of electron loss on one hand, and of electron capture on the other hand

The new ATLAS Fast Calorimeter Simulation

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00223142; The ATLAS collaboration

2016-01-01

Many physics and performance studies with the ATLAS detector at the Large Hadron Collider require very large samples of simulated events, and producing these using the full GEANT4 detector simulation is highly CPU intensive. Often, a very detailed detector simulation is not needed, and in these cases fast simulation tools can be used to reduce the calorimeter simulation time by a few orders of magnitude. The new ATLAS Fast Calorimeter Simulation (FastCaloSim) is an improved parametrisation compared to the one used in the LHC Run-1. It provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitization and reconstruction software, and can be tuned to data more easily than with GEANT4. The new FastCaloSim incorporates developments in geometry and physics lists of the last five years and benefit...

A fast tomographic method for searching the minimum free energy path

International Nuclear Information System (INIS)

Chen, Changjun; Huang, Yanzhao; Xiao, Yi; Jiang, Xuewei

2014-01-01

Minimum Free Energy Path (MFEP) provides a lot of important information about the chemical reactions, like the free energy barrier, the location of the transition state, and the relative stability between reactant and product. With MFEP, one can study the mechanisms of the reaction in an efficient way. Due to a large number of degrees of freedom, searching the MFEP is a very time-consuming process. Here, we present a fast tomographic method to perform the search. Our approach first calculates the free energy surfaces in a sequence of hyperplanes perpendicular to a transition path. Based on an objective function and the free energy gradient, the transition path is optimized in the collective variable space iteratively. Applications of the present method to model systems show that our method is practical. It can be an alternative approach for finding the state-to-state MFEP

High-speed, multi-channel detector readout electronics for fast radiation detectors

International Nuclear Information System (INIS)

Hennig, Wolfgang

2012-01-01

In this project, we are developing a high speed digital spectrometer that a) captures detector waveforms at rates up to 500 MSPS b) has upgraded event data acquisition with additional data buffers for zero dead time operation c) moves energy calculations to the FPGA to increase spectrometer throughput in fast scintillator applications d) uses a streamlined architecture and high speed data interface for even faster readout to the host PC These features are in addition to the standard functions in our existing spectrometers such as digitization, programmable trigger and energy filters, pileup inspection, data acquisition with energy and time stamps, MCA histograms, and run statistics. In Phase I, we upgraded one of our existing spectrometer designs to demonstrate the key principle of fast waveform capture using a 500 MSPS, 12 bit ADC and a Xilinx Virtex-4 FPGA. This upgraded spectrometer, named P500, performed well in initial tests of energy resolution, pulse shape analysis, and timing measurements, thus achieving item (a) above. In Phase II, we are revising the P500 to build a commercial prototype with the improvements listed in items (b)-(d). As described in the previous report, two devices were built to pursue this goal, named the Pixie-500 and the Pixie-500 Express. The Pixie-500 has only minor improvements from the Phase I prototype and is intended as an early commercial product (its production and part of its development were funded outside the SBIR). It also allows testing of the ADC performance in real applications. The Pixie-500 Express (or Pixie-500e) includes all of the improvements (b)-(d). At the end of Phase II of the project, we have tested and debugged the hardware, firmware and software of the Pixie-500 Express prototype boards delivered 12/3/2010. This proved substantially more complex than anticipated. At the time of writing, all hardware bugs have been fixed, the PCI Express interface is working, the SDRAM has been successfully tested and the

High-speed, multi-channel detector readout electronics for fast radiation detectors

Energy Technology Data Exchange (ETDEWEB)

Hennig, Wolfgang

2012-06-22

In this project, we are developing a high speed digital spectrometer that a) captures detector waveforms at rates up to 500 MSPS b) has upgraded event data acquisition with additional data buffers for zero dead time operation c) moves energy calculations to the FPGA to increase spectrometer throughput in fast scintillator applications d) uses a streamlined architecture and high speed data interface for even faster readout to the host PC These features are in addition to the standard functions in our existing spectrometers such as digitization, programmable trigger and energy filters, pileup inspection, data acquisition with energy and time stamps, MCA histograms, and run statistics. In Phase I, we upgraded one of our existing spectrometer designs to demonstrate the key principle of fast waveform capture using a 500 MSPS, 12 bit ADC and a Xilinx Virtex-4 FPGA. This upgraded spectrometer, named P500, performed well in initial tests of energy resolution, pulse shape analysis, and timing measurements, thus achieving item (a) above. In Phase II, we are revising the P500 to build a commercial prototype with the improvements listed in items (b)-(d). As described in the previous report, two devices were built to pursue this goal, named the Pixie-500 and the Pixie-500 Express. The Pixie-500 has only minor improvements from the Phase I prototype and is intended as an early commercial product (its production and part of its development were funded outside the SBIR). It also allows testing of the ADC performance in real applications.The Pixie-500 Express (or Pixie-500e) includes all of the improvements (b)-(d). At the end of Phase II of the project, we have tested and debugged the hardware, firmware and software of the Pixie-500 Express prototype boards delivered 12/3/2010. This proved substantially more complex than anticipated. At the time of writing, all hardware bugs have been fixed, the PCI Express interface is working, the SDRAM has been successfully tested and the SHARC

Integral Fast Reactor: A future source of nuclear energy

International Nuclear Information System (INIS)

Southon, R.

1993-01-01

Argonne National Laboratory is developing a reactor concept that would be an important part of the worlds energy future. This report discusses the Integral Fast Reactor (IFR) concept which provides significant improvements over current generation reactors in reactor safety, plant complexity, nuclear proliferation, and waste generation. Two major facilities, a reactor and a fuel cycle facility, make up the IFR concept. The reactor uses fast neutrons and metal fuel in a sodium coolant at atmospheric pressure that relies on laws of physics to keep it safe. The fuel cycle facility is a hot cell using remote handling techniques for fabricating reactor fuel. The fuel feed stock includes spent fuel from the reactor, and potentially, spent light water reactor fuel and plutonium from weapons. This paper discusses the unique features of the IFR concept and the differences the quality assurance program has from current commercial practices. The IFR concept provides an opportunity to design a quality assurance program that makes use of the best contemporary ideas on management and quality

Antiproton fast ignition for inertial confinement fusion

International Nuclear Information System (INIS)

Perkins, L.J.

1999-01-01

With 180 MJ/microg, antiprotons offer the highest stored energy per unit mass of any known entity. The use of antiprotons to promote fast ignition in an inertial confinement fusion (ICF) capsule and produce high target gains with only modest compression of the main fuel is investigated. Unlike standard fast ignition where the ignition energy is supplied by energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. This can be considered in-situ fast ignition as it obviates the need for the external injection of the ignition energy. In the first of two candidate schemes, the antiproton package is delivered by a low-energy ion beam. In the second, autocatalytic scheme, the antiprotons are preemplaced at the center of the capsule prior to compression. In both schemes, the author estimates that ∼10 12 antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition within the ignitor zone. In addition to eliminating the need for a second, energetic fast laser and vulnerable final optics, this scheme would achieve central ignition without reliance on laser channeling through halo plasma or Hohlraum debris. However, in addition to the practical difficulties of storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a speculative scheme is the ultimate efficiency of antiproton production in an external, optimized facility. Estimates suggest that the electrical wall plug energy per pulse required for the separate production of the antiprotons is of the same order as that required for the conventional slow compression driver

Energy and Pitch Distribution of Spontaneously-generated High-energy Bulk Ions in the RFP

Science.gov (United States)

Kim, Jungha; Anderson, Jay; Reusch, Joshua; Eilerman, Scott; Capecchi, William

2014-10-01

Magnetic reconnection events in the reversed field pinch (RFP) are known to heat bulk and impurity ions. Runaway due to a parallel electric field has recently been confirmed as an important acceleration mechanism for high energy test ions supplied by a neutral beam. This effect does not, however, explain the change in distribution of nearly Maxwellian bulk ions at a reconnection event. By operating MST near maximum current and low electron density, significant fusion neutron flux can be generated without neutral beam injection. The bulk ion distribution created in these plasmas is well-confined, non-Maxwellian, and can be measured by the Advanced Neutral Particle Analyzer (ANPA) placed at a radial or tangential porthole. Data show a high energy tail up to 25 keV with a relatively higher signal in the low energy channels (8-15 keV) at the radial port following a reconnection event. Analysis of the energy dependence of trapped orbits sampled by the ANPA at the radial view implies an abundance of lower energy particles in regions of higher neutral density. This mandates a careful deconvolution of the measured ANPA signal to compute the fast ion distribution. This work is supported by the US DOE and NSF.

High-sensitive spectrometer of fast neutrons and the results of fast neutron background flux measurements at the gallium-germanium solar neutrino experiment (SAGE)

International Nuclear Information System (INIS)

Abdurashitov, D.N.; Gavrin, V.N.; Kalikhov, A.V.; Matushko, V.L.; Shikhin, A.A.; Yants, V.E.; Zaborskaya, O.S.

2001-01-01

The principle of operation, design, registration system and main characteristics of a fast neutron spectrometer are described. The spectrometer is intended for direct measurements of ultra-low fluxes of fast neutrons. It is sensitive to neutron fluxes of 10 -7 cm -2 · s -1 and lower. The detection efficiency of fast neutrons with simultaneous energy measurement was determined from Monte-Carlo simulation to be equal to 0.11 ± 0.01. The background counting rate in the detector corresponds to a neutron flux of (6.5 ± 2.1) · 10 -7 cm -2 · s -1 in the range of 1.0-11.0 MeV. The natural neutron flux from the surrounding mine rock at the depth of 4600 meters of water equivalent was measured to be (7.3 ± 2.4) · 10 -7 cm -2 · s -1 in the interval 1.0 -11.0 MeV. The flux of fast neutrons in the SAGE main room was measured to be 2.3 · 10 -7 cm -2 · s -1 in 1.0 - 11.0 MeV energy range

Final stage of high energy hadron-nucleus nuclear collision reactions

International Nuclear Information System (INIS)

Strugal'ski, Z.; Jedrzejec, H.; Strugalska-Gola, E.; Mulas, E.

1996-01-01

The final or 'slow' stage of the hadron-nucleus collision reactions at high energy is considered on the basis of the collision mechanism prompted experimentally. The transmutation process of the damaged target nucleus into nucleons and stable nuclear fragments is discussed. Relations between intensities or multiplicities n p of the emitted fast protons and the mean intensities or multiplicities b > of the evaporated nucleons and nuclear fragments are presented. 14 refs

High-sensitive spectrometer of fast neutrons and the results of fast neutron background flux measurements at the Gallium-Germanium Solar Neutrino Experiment

CERN Document Server

Abdurashitov, J N; Kalikhov, A V; Matushko, V L; Shikhin, A A; Yants, V E; Zaborskaia, O S

2002-01-01

The principle of operation, design, registration system and main characteristics of a fast neutron spectrometer are described. The spectrometer is intended for direct measurements of ultra low fluxes of fast neutrons. It is sensitive to neutron fluxes of 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 and lower. The detection efficiency of fast neutrons with simultaneous energy measurement was determined from Monte-Carlo simulation to be equal to 0.11+-0.01. The background counting rate in the detector corresponds to a neutron flux of (6.5+-2.1)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The natural neutron flux from the surrounding mine rock at the depth of 4600 m of water equivalent was measured to be (7.3+-2.4)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The flux of fast neutrons in the SAGE main room was measured to be <2.3x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in 1.0-11.0 MeV energy range.

Non-fasting factor VII coagulant activity (FVII:C) increased by high-fat diet

DEFF Research Database (Denmark)

Bladbjerg, Else-Marie; Marckmann, P; Sandström, B

1994-01-01

:Bt/FVII:Am (a measure of FVII activation) increased from fasting levels on both diets, but most markedly on the high-fat diet. In contrast, FVII:Am (a measure of FVII protein) tended to decrease from fasting levels on both diets. FVII:C rose from fasting levels on the high-fat diet, but not on the low-fat diet....... The findings suggest that high-fat diets increase non-fasting FVII:C, and consequently may be associated with increased risk of thrombosis. Udgivelsesdato: 1994-Jun......Preliminary observations have suggested that non-fasting factor VII coagulant activity (FVII:C) may be related to the dietary fat content. To confirm this, we performed a randomised cross-over study. Seventeen young volunteers were served 2 controlled isoenergetic diets differing in fat content (20...

Anti-Ferroelectric Ceramics for High Energy Density Capacitors

Directory of Open Access Journals (Sweden)

Aditya Chauhan

2015-11-01

Full Text Available With an ever increasing dependence on electrical energy for powering modern equipment and electronics, research is focused on the development of efficient methods for the generation, storage and distribution of electrical power. In this regard, the development of suitable dielectric based solid-state capacitors will play a key role in revolutionizing modern day electronic and electrical devices. Among the popular dielectric materials, anti-ferroelectrics (AFE display evidence of being a strong contender for future ceramic capacitors. AFE materials possess low dielectric loss, low coercive field, low remnant polarization, high energy density, high material efficiency, and fast discharge rates; all of these characteristics makes AFE materials a lucrative research direction. However, despite the evident advantages, there have only been limited attempts to develop this area. This article attempts to provide a focus to this area by presenting a timely review on the topic, on the relevant scientific advancements that have been made with respect to utilization and development of anti-ferroelectric materials for electric energy storage applications. The article begins with a general introduction discussing the need for high energy density capacitors, the present solutions being used to address this problem, and a brief discussion of various advantages of anti-ferroelectric materials for high energy storage applications. This is followed by a general description of anti-ferroelectricity and important anti-ferroelectric materials. The remainder of the paper is divided into two subsections, the first of which presents various physical routes for enhancing the energy storage density while the latter section describes chemical routes for enhanced storage density. This is followed by conclusions and future prospects and challenges which need to be addressed in this particular field.

Aortic endograft surveillance: use of fast-switch kVp dual-energy computed tomography with virtual noncontrast imaging.

Science.gov (United States)

Maturen, Katherine E; Kleaveland, Patricia A; Kaza, Ravi K; Liu, Peter S; Quint, Leslie E; Khalatbari, Shokoufeh H; Platt, Joel F

2011-01-01

To assess endoleak detection and patients' radiation exposure using fast-switch peak kilovoltage (kVp) dual-energy computed tomography (DECT) with virtual noncontrast (VNC) imaging. Institutional review board approved retrospective review of triphasic CTs for endograft follow-up: single-energy true noncontrast (TNC) and dual-energy arterial- and venous-phase postcontrast scans on GE HD-750 64-detector scanners. Iodine-subtracted VNC images generated from dual-energy data. Two radiologists (VNC readers) independently performed 2 reading sessions without TNC images: (1) arterial and VNC and (2) venous and VNC. Interrater agreement, leak detection sensitivity, and dose estimates were calculated. Original dictations described 24 endoleaks in 78 scans. Virtual noncontrast reader agreement was high (κ = 0.78-0.79). Virtual noncontrast reader ranges for sensitivity and negative predictive value for leak detection were 87.5% to 95.8% and 94.0% to 98.0% in venous phase. Dose reduction estimate was 40% by eliminating one phase and 64% by eliminating 2 phases of imaging. Virtual noncontrast images from fast-switch peak kilovoltage DECT data can substitute for TNC imaging in the postendograft aorta, conferring substantial dose reduction. Eliminating 1 of 2 postcontrast phases further reduces dose, with greater negative predictive value for leak detection in the venous versus the arterial phase. Thus, the use of a monophasic venous-phase DECT with VNC images is suggested for long-term endograft surveillance in stable patients.

Construction of a High Temporal-spectral Resolution Spectrometer for Detection of Fast Transients from Observations of the Sun at 1.4 GHz.

Science.gov (United States)

Casillas-Perez, G. A.; Jeyakumar, S.; Perez-Enriquez, R.

2014-12-01

Transients explosive events with time durations from nanoseconds to several hours, are observed in the Sun at high energy bands such as gamma ray and xray. In the radio band, several types of radio bursts are commonly detected from the ground. A few observations of the Sun in the past have also detected a new class of fast transients which are known to have short-live electromagnetic emissions with durations less than 100 ms. The mechanisms that produce such fast transiets remain unclear. Observations of such fast transients over a wide bandwidth is necessary to uderstand the underlying physical process that produce such fast transients. Due to their very large flux densities, fast radio transients can be observed at high time resolution using small antennas in combination with digital signal processing techniques. In this work we report the progress of an spectrometer that is currently in construction at the Observatorio de la Luz of the Universidad de Guanajuato. The instrument which will have the purpose of detecting solar fast radio transients, involves the use of digital devices such as FPGA and ADC cards, in addition with a receiver with high temporal-spectral resolution centered at 1.4 GHz and a pair of 2.3 m satellite dish.

[Fast food promotes weight gain].

Science.gov (United States)

Stender, Steen; Dyerberg, Jørn; Astrup, Arne V

2007-05-07

The total amounts of fat in a fast food menu consisting of French fries and fried Chicken Nuggets from McDonald's and KFC, respectively, bought in 35 different countries vary from 41 to 71 gram. In most countries the menu contained unacceptably high amounts of industrially-produced trans fat which contributes to an increased risk of ischaemic heart disease, weight gain, abdominal fat accumulation and type 2 diabetes. The quality of the ingredients in fast food ought to be better and the size of the portions smaller and less energy-dense so that frequent fast food meals do not increase the risk of obesity and diseases among customers.

Energy measurement of fast ions trapped in the toroidal field ripple of Tore Supra

International Nuclear Information System (INIS)

Basiuk, V.; Becoulet, A.; Hutter, T.; Martin, G.; Pecquet, A.L.; Saoutic, B.

1993-09-01

During additional heating in Tore Supra (ICRF or NBI) fast ion losses due to the toroidal field ripple were clearly measured by a set of graphite probes. This diagnostic collects the flow of fast ions entering a vertical port and usually shows a maximum flux for ions originating from the vicinity of surface δ * = 0. During the monster sawteeth regime, achieved with ICRF, a remarkable phenomenon was observed: the ejection of fast ions, not correlated with any measured MHD activity. The radial distribution of these ions is quite different from that usually observed exhibiting a peak located in the central section of the plasma. In order to measure the energy distribution of these ions, from 80 keV (energy of the neutral beam injected in Tore Supra) up to 1 MeV (expected during ICRF), a new diagnostic is under construction. The principle of the diagnostic is to discriminate the ions in energy using their Larmor radius (p = 1.3 cm for 100 keV → p = 3.6 cm for 700 keV, B = 4T). The detector is made of a hollow graphite cylinder with a small entrance slot, located in a vertical port on the ion drift side. An array of six metallic collectors placed inside the graphite cylinder intercepts the ions. The current on each collector was estimated at 10 → 100 nA, during ICRF heating. The energy resolution of this diagnostic is expected to be about 20 keV for the lowest energy range and 100 keV for the highest. This type of ruggedized detector might be extrapolated for the measurements of alpha particle losses in future DT experiments. It should also be suitable for the studies of stochastic ripple diffusion. (authors). 3 refs., 9 figs

Optimal condition of torrefaction for high energy density solid fuel of fast growing tree species

Energy Technology Data Exchange (ETDEWEB)

Kim, Young-Hun; Na, Byeong-Il; Lee, Hyoung-Woo; Lee, Jae-Won [College of Agriculture and Life Sciences, Chonnam National University, Gwangju (Korea, Republic of); Ahn, Byoung-Jun [Korea Forest Research Institute, Seoul (Korea, Republic of)

2015-08-15

The torrefaction properties of Acacia (Acacia mangium) and Albasia (Paraserianthes falcataria) were investigated by response surface methodology. Torrefaction was performed at 220-280 .deg. C for 20-80 min depending on severity factor. Carbon content in the torrefied biomass increased with severity factor, whereas hydrogen and oxygen contents decreased both biomass. The calorific value of torrefied Acacia ranged from 20.03 to 21.60 MJ/kg, suggesting that the energy contained in the torrefied biomass increased by 5.09 to 13.62%, when compared with that in the untreated biomass. However, the calorific value of Albasia was relatively low, compared to that of torrefied Acacia. The weight loss of Albasia was higher than that of Acacia under a given torrefaction condition. The reaction temperature for torrefaction was an important factor to obtain high energy yield, whereas the effect of time was considerable lower. High temperature and short torrefaction time is required to obtain the highest energy yield from torrefaction using Acacia and Albasia.

On the problem of monitoring the neutron parameters of the Fast Energy Amplifier

International Nuclear Information System (INIS)

Behringer, K.; Wydler, P.

1998-10-01

The conceptual Fast Energy Amplifier, proposed by Rubbia et al. (1995), consists of a combination of a U-233/Th-232 fuelled fast-neutron subcritical facility with a proton accelerator. An intense beam of 1 GeV protons is injected into liquid lead at the core centre and drives the reactor by producing spallation neutrons. The burst of spallation neutrons produced by a single proton alters the basic neutron statistics which are well known for thermal neutrons in conventional nuclear reactors. A short assessment of standard neutron noise analysis methods is made with respect to monitoring neutron parameter data. (author)

Fast Learning for Immersive Engagement in Energy Simulations

Energy Technology Data Exchange (ETDEWEB)

Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bugbee, Bruce [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krishnan, Venkat K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Potter, Kristin C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-25

The fast computation which is critical for immersive engagement with and learning from energy simulations would be furthered by developing a general method for creating rapidly computed simplified versions of NREL's computation-intensive energy simulations. Created using machine learning techniques, these 'reduced form' simulations can provide statistically sound estimates of the results of the full simulations at a fraction of the computational cost with response times - typically less than one minute of wall-clock time - suitable for real-time human-in-the-loop design and analysis. Additionally, uncertainty quantification techniques can document the accuracy of the approximate models and their domain of validity. Approximation methods are applicable to a wide range of computational models, including supply-chain models, electric power grid simulations, and building models. These reduced-form representations cannot replace or re-implement existing simulations, but instead supplement them by enabling rapid scenario design and quality assurance for large sets of simulations. We present an overview of the framework and methods we have implemented for developing these reduced-form representations.

The effect of energy and traffic light labelling on parent and child fast food selection: a randomised controlled trial.

Science.gov (United States)

Dodds, Pennie; Wolfenden, Luke; Chapman, Kathy; Wellard, Lyndal; Hughes, Clare; Wiggers, John

2014-02-01

Labelling of food from fast food restaurants at point-of-purchase has been suggested as one strategy to reduce population energy consumption and contribute to reductions in obesity prevalence. The aim of this study was to examine the effects of energy and single traffic light labelling systems on the energy content of child and adult intended food purchases. The study employed a randomised controlled trial design. English speaking parents of children aged between three and 12 years were recruited from an existing research cohort. Participants were mailed one of three hypothetical fast food menus. Menus differed in their labelling technique – either energy labels, single traffic light labels, or a no-label control. Participants then completed a telephone survey which assessed intended food purchases for both adult and child. The primary trial outcome was total energy of intended food purchase. A total of 329 participants completed the follow-up telephone interview. Eighty-two percent of the energy labelling group and 96% of the single traffic light labelling group reported noticing labelling information on their menu. There were no significant differences in total energy of intended purchases of parents, or intended purchases made by parents for children, between the menu labelling groups, or between menu labelling groups by socio-demographic subgroups. This study provided no evidence to suggest that energy labelling or single traffic light labelling alone were effective in reducing the energy of fast food items selected from hypothetical fast food menus for purchase. Additional complementary public health initiatives promoting the consumption of healthier foods identified by labelling, and which target other key drivers of menu item selection in this setting may be required.

A new Recoil Proton Telescope for energy and fluence measurement of fast neutron fields

Energy Technology Data Exchange (ETDEWEB)

Lebreton, Lena; Bachaalany, Mario [IRSN / LMDN (Institut de Radioprotection et de Surete nucleaire / Laboratoire de Metrologie et de dosimetrie des neutrons), Cadarache Bat.159, 13115 Saint Paul-lez-Durance, (France); Husson, Daniel; Higueret, Stephane [IPHC / RaMsEs (Institut Pluridisciplinaire Hubert Curien / Radioprotection et Mesures Environnementales), 23 rue du loess - BP28, 67037 Strasbourg cedex 2, (France)

2015-07-01

The spectrometer ATHENA (Accurate Telescope for High Energy Neutron metrology Applications), is being developed at the IRSN / LMDN (Institut de Radioprotection et de Surete nucleaire / Laboratoire de Metrologie et de dosimetrie des neutrons) and aims at characterizing energy and fluence of fast neutron fields. The detector is a Recoil Proton Telescope and measures neutron fields in the range of 5 to 20 MeV. This telescope is intended to become a primary standard for both energy and fluence measurements. The neutron detection is achieved by a polyethylene radiator for n-p conversion, three 50{sub m} thick silicon sensors that use CMOS technology for the proton tracking and a 3 mm thick silicon diode to measure the residual proton energy. This first prototype used CMOS sensors called MIMOSTAR, initially developed for heavy ion physics. The use of CMOS sensors and silicon diode increases the intrinsic efficiency of the detector by a factor of ten compared with conventional designs. The first prototype has already been done and was a successful study giving the results it offered in terms of energy and fluence measurements. For mono energetic beams going from 5 to 19 MeV, the telescope offered an energy resolution between 5 and 11% and fluence difference going from 5 to 7% compared to other home standards. A second and final prototype of the detector is being designed. It will hold upgraded CMOS sensors called FastPixN. These CMOS sensors are supposed to run 400 times faster than the older version and therefore give the telescope the ability to support neutron flux in the order of 107 to 108cm{sup 2}:s{sup 1}. The first prototypes results showed that a 50 m pixel size is enough for a precise scattering angle reconstruction. Simulations using MCNPX and GEANT4 are already in place for further improvements. A DeltaE diode will replace the third CMOS sensor and will be installed right before the silicon diode for a better recoil proton selection. The final prototype with

A method for solving the spherical harmonics equations applied for space-energy transport of fast and resonance neutrons

International Nuclear Information System (INIS)

Matausek, M.

1972-01-01

A new proposed method for solving the space-energy dependent spherical harmonics equations represents a methodological contribution to neutron transport theory. The proposed method was applied for solving the problem of spec-energy transport of fast and resonance neutrons in multi-zone, cylindrical y symmetric infinite reactor cell and is related to previously developed procedure for treating the thermal energy region. The advantages of this method are as follows: a unique algorithm was obtained for detailed determination of spatial and energy distribution of neutrons (from thermal to fast) in the reactor cell; these detailed distributions enable more precise calculations of criticality conditions, obtaining adequate multigroup data and better interpretation of experimental data; computing time is rather short

High-ampacity conductive polymer microfibers as fast response wearable heaters and electromechanical actuators

KAUST Repository

Zhou, Jian; Mulle, Matthieu; Zhang, Yaobin; Xu, Xuezhu; Li, Erqiang; Han, Fei; Thoroddsen, Sigurdur T; Lubineau, Gilles

2016-01-01

Conductive fibers with enhanced physical properties and functionalities are needed for a diversity of electronic devices. Here, we report very high performance in the thermal and mechanical response of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) microfibers when subjected to an electrical current. These fibers were made by combining the hot-drawing assisted wetspinning process with ethylene glycol doping/de-doping that can work at a current density as high as 1.8 × 104 A cm−2, which is comparable to that of carbon nanotube fibers. Their electrothermal response was investigated using optical sensors and verified to be as fast as 63 °C s−1 and is comparable with that of metallic heating elements (20–50 °C s−1). We investigated the electromechanical actuation resulted from the reversible sorption/desorption of moisture controlled by electro-induced heating. The results revealed an improvement of several orders of magnitudes compared to other linear conductive polymer-based actuators in air. Specifically, the fibers we designed here have a rapid stress generation rate (>40 MPa s−1) and a wide operating frequency range (up to 40 Hz). These fibers have several characteristics including fast response, low-driven voltage, good repeatability, long cycle life and high energy efficiency, favoring their use as heating elements on wearable textiles and as artificial muscles for robotics.

High-ampacity conductive polymer microfibers as fast response wearable heaters and electromechanical actuators

KAUST Repository

Zhou, Jian

2016-01-04

Conductive fibers with enhanced physical properties and functionalities are needed for a diversity of electronic devices. Here, we report very high performance in the thermal and mechanical response of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) microfibers when subjected to an electrical current. These fibers were made by combining the hot-drawing assisted wetspinning process with ethylene glycol doping/de-doping that can work at a current density as high as 1.8 × 104 A cm−2, which is comparable to that of carbon nanotube fibers. Their electrothermal response was investigated using optical sensors and verified to be as fast as 63 °C s−1 and is comparable with that of metallic heating elements (20–50 °C s−1). We investigated the electromechanical actuation resulted from the reversible sorption/desorption of moisture controlled by electro-induced heating. The results revealed an improvement of several orders of magnitudes compared to other linear conductive polymer-based actuators in air. Specifically, the fibers we designed here have a rapid stress generation rate (>40 MPa s−1) and a wide operating frequency range (up to 40 Hz). These fibers have several characteristics including fast response, low-driven voltage, good repeatability, long cycle life and high energy efficiency, favoring their use as heating elements on wearable textiles and as artificial muscles for robotics.

Response of appetite and potential appetite regulators following intake of high energy nutritional supplements.

Science.gov (United States)

Fatima, Sadia; Gerasimidis, Konstantinos; Wright, Charlotte; Tsiountsioura, Melina; Arvanitidou, Eirini-Iro; Malkova, Dalia

2015-12-01

The net clinical benefit of high-energy nutritional supplements (HENSDs) consumption is lower than expected. To investigate the extent to which consumption of oral HENSD in the fasted state reduces energy intake in slim females during consecutive breakfast and lunch, and whether this relates to changes in appetite and metabolic appetite regulators. Twenty three females of 24.4 ± 2.8 years with BMI of 18.2 ± 0.8 kg/m(2) consumed HENSD (2.5 MJ) or PLACEBO (0.4 MJ) in fasted state in a single blind randomized cross-over study. Appetite and metabolic rate measurements and blood collection were conducted prior to and during 240 min after the intake of the supplements. Energy intake was recorded during ad libitum buffet breakfast and lunch served 60 min and 240 min post supplementation respectively. Energy intake during breakfast was significantly (P appetite measures were not significantly different between HENSD and PLACEBO trials. Correlations for the within participant relations between the responses of plasma hormones and appetite scores were significant (P < 0.05) for PYY and insulin but not CCK. The energy expended above resting metabolic rate was significantly (P < 0.05) higher in the HENDS trial but relative increase in energy expenditure was not significantly different between the two trials. Oral high-energy nutritional supplements have a partial and relatively short lived suppressive action on energy intake and can be expected to increase net energy intake by approximately half the energy value of the supplement consumed. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Novel fast-neutron activation counter for high repetition rate measurements

International Nuclear Information System (INIS)

Mahmood, S.; Springham, S. V.; Zhang, T.; Rawat, R. S.; Tan, T. L.; Krishnan, M.; Beg, F. N.; Lee, S.; Schmidt, H.; Lee, P.

2006-01-01

A fast-neutron beryllium activation counter has been constructed for neutron measurements on a high repetition rate deuterium plasma focus. Beryllium activation is especially suitable for measurements of DD neutron yields. The cross section for the relevant reaction, 9 Be(n,α) 6 He, results in a maximum sensitivity at the characteristic energy of the DD neutrons (∼2.5 MeV) and practically no sensitivity to neutrons with energies 6 He enabled the shot-to-shot neutron yield from the plasma focus to be measured for repetition rates from 0.2 to 3 Hz (and for a range of deuterium gas pressures). With careful analysis, the shot-to-shot yield can be measured up to a maximum repetition rate of 3 Hz, beyond which the pileup of counts from the previous shots reduces the accuracy of the measurements to an unacceptable level. This new beryllium activation counter has been cross-checked against an indium activation counter to obtain absolute neutron yields. At a charging voltage of 12.5 kV (bank energy of 2.2 kJ), the average neutron yield was found to be (7.9±0.7)x10 7 per shot (standard deviation of 4x10 7 ). It was found that activation of the plasma focus construction materials (especially aluminum) must be taken into account

FastBit: Interactively Searching Massive Data

Energy Technology Data Exchange (ETDEWEB)

Wu, Kesheng; Ahern, Sean; Bethel, E. Wes; Chen, Jacqueline; Childs, Hank; Cormier-Michel, Estelle; Geddes, Cameron; Gu, Junmin; Hagen, Hans; Hamann, Bernd; Koegler, Wendy; Lauret, Jerome; Meredith, Jeremy; Messmer, Peter; Otoo, Ekow; Perevoztchikov, Victor; Poskanzer, Arthur; Prabhat,; Rubel, Oliver; Shoshani, Arie; Sim, Alexander; Stockinger, Kurt; Weber, Gunther; Zhang, Wei-Ming

2009-06-23

As scientific instruments and computer simulations produce more and more data, the task of locating the essential information to gain insight becomes increasingly difficult. FastBit is an efficient software tool to address this challenge. In this article, we present a summary of the key underlying technologies, namely bitmap compression, encoding, and binning. Together these techniques enable FastBit to answer structured (SQL) queries orders of magnitude faster than popular database systems. To illustrate how FastBit is used in applications, we present three examples involving a high-energy physics experiment, a combustion simulation, and an accelerator simulation. In each case, FastBit significantly reduces the response time and enables interactive exploration on terabytes of data.

Energy contribution of sugar-sweetened beverage refills at fast-food restaurants.

Science.gov (United States)

Breck, Andrew; Cantor, Jonathan H; Elbel, Brian

2017-09-01

To identify demographic and consumer characteristics associated with refilling a soft drink at fast-food restaurants and the estimated energy content and volume of those refills. Logistic and linear regression with cross-sectional survey data. Data include fast-food restaurant receipts and consumer surveys collected from restaurants in New York City (all boroughs except Staten Island), and Newark and Jersey City, New Jersey, during 2013 and 2014. Fast-food restaurant customers (n 11795) from ninety-eight restaurants. Thirty per cent of fast-food customers ordered a refillable soft drink. Nine per cent of fast-food customers with a refillable soft drink reported refilling their beverage (3 % of entire sample). Odds of having a beverage refill were higher among respondents with a refillable soft drink at restaurants with a self-serve refill kiosk (adjusted OR (aOR)=7·37, Prestaurant (aOR=4·45, P<0·001). KFC (aOR=2·18, P<0·001) and Wendy's (aOR=0·41, P<0·001) customers had higher and lower odds, respectively, of obtaining a refill, compared with Burger King customers. Respondents from New Jersey (aOR=1·47, P<0·001) also had higher odds of refilling their beverage than New York City customers. Customers who got a refill obtained on average 29 more 'beverage ounces' (858 ml) and 250 more 'beverage calories' (1046 kJ) than customers who did not get a refill. Refilling a beverage was associated with having obtained more beverage calories and beverage ounces. Environmental cues, such as the placement and availability of self-serve beverage refills, may influence consumer beverage choice.

Comparison of biomolecule desorption yields for low and high energy primary ions

International Nuclear Information System (INIS)

Kamensky, I.; Hakansson, P.; Sundqvist, B.; McNeal, C.J.; MacFarlane, R.

1982-01-01

Ion induced desorption yields of molecular ions from samples of cesium iodide, glycylglycine, ergosterol, bleomycin and a trinucleoside diphosphate have been studied using primary beams of 54 MeV 63 Cu 9+ and 3 keV 133 Cs + . Mass analysis was performed with a time-of-flight technique. Each sample was studied with the same spectrometer for both low and high energy primary ions and without opening of the vacuum chamber in between the measurements. The results show that fast heavy ions give larger yields for all samples studied and that the yield ratios for high to low energy desorption increase with the mass of the sample molecule. (orig.)

Nucleus fragmentation induced by a high-energy hadron

International Nuclear Information System (INIS)

Zielinski, P.

1982-10-01

The author presents a review about the spallation in hadron reactions. Especially he considers proton-proton correlations at low relative momentum, angular distributions of 30-100 MeV protons, emission of fast deuterons, the vanishing of the Coulomb barrier, fission-like processes, the rise of the heavy fragment yield with energy transfer, proton-deuteron breakup reactions, and the backward emission of fast protons. (HSI)

Cooperative ad hoc networks for energy and delay efficient content distribution with fast channel variations

KAUST Repository

Atat, Rachad

2012-11-20

Cooperative ad hoc networks for the efficient distribution of content of common interest are studied in the case of fast channel variations. Mobiles are grouped into cooperative clusters for the purpose of receiving the content with optimized energy efficiency. Data are sent to mobile terminals on a long range (LR) link, and then, the terminals exchange the content by using an appropriate short range wireless technology. When channel state information is available for the LR links, unicasting is used on the LR. When accurate channel state information is not available, threshold-based multicasting is implemented on the LR. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form in scenarios with fast channel variations. Results show significant energy savings in the proposed schemes compared with the noncooperative case and other previous related work. Furthermore, the energy minimizing solutions are shown to lead to reduced delay in the content distribution process. Practical implementation aspects of the proposed methods are also discussed. © 2012 John Wiley & Sons, Ltd.

Cooperative ad hoc networks for energy and delay efficient content distribution with fast channel variations

KAUST Repository

Atat, Rachad; Yaacoub, Elias E.; Alouini, Mohamed-Slim; Abu-Dayya, Adnan A.

2012-01-01

Cooperative ad hoc networks for the efficient distribution of content of common interest are studied in the case of fast channel variations. Mobiles are grouped into cooperative clusters for the purpose of receiving the content with optimized energy efficiency. Data are sent to mobile terminals on a long range (LR) link, and then, the terminals exchange the content by using an appropriate short range wireless technology. When channel state information is available for the LR links, unicasting is used on the LR. When accurate channel state information is not available, threshold-based multicasting is implemented on the LR. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form in scenarios with fast channel variations. Results show significant energy savings in the proposed schemes compared with the noncooperative case and other previous related work. Furthermore, the energy minimizing solutions are shown to lead to reduced delay in the content distribution process. Practical implementation aspects of the proposed methods are also discussed. © 2012 John Wiley & Sons, Ltd.

Fast hisslers: a form of magnetospheric radio emissions

International Nuclear Information System (INIS)

Siren, J.C.

1974-01-01

Auroral radio hiss bursts in the frequency range 2-18 kHz have been observed, with rise or turn-on-times of 20-50 ms, and fall or turn-off times of 20-80 ms. These time scales are too brief to reconcile with the Cerenkov radiation emission mechanism often proposed as the transducer that converts precipitating auroral electron kinetic energy into very-low-frequency radio wave energy. The auroral hiss bursts, called here ''fast hisslers,'' are observed to be ''dispersed,', that is, their arrival time at the receiving site is not simultaneous at all frequencies, but depends on frequency in a way that is consistent with propagation in the whistler mode of electromagnetic wave propagation. Since whistler mode wave propagation at these frequencies occurs only in the earth' magnetosphere, it is inferred that these fast hisslers are of magnetospheric origin. On the assumption that all the observed dispersion results from whistler mode dispersion at high latitudes, altitudes of origin of 1800 km to 30,000 km are calculated for these emissions. Fine details of some of the amplitude spectra of fast hisslers have been examined. Potential double layers have been investigated as a highly localized region of acceleration of the auroral electrons that are believed to be the source of energy of the fast hisslers. Evidence is strong that a plasma instability exists which rapidly converts electron kinetic energies into whistler-mode wave energy traveling in the same direction relative to the rest frame of the thermal magnetospheric plasma

Exploratory studies on fast pyrolysis oil upgrading

NARCIS (Netherlands)

Mahfud, Farchad Husein

2007-01-01

Pyrolysis oil is a dark brown liquid which can be produced in high yield from different kind of biomass sources by means of fast pyrolysis. Pyrolysis oil is considered as a promising second generation energy carrier and may play an important role in the future of "biobased economies". The energy

Gluconeogenesis is associated with high rates of tricarboxylic acid and pyruvate cycling in fasting northern elephant seals.

Science.gov (United States)

Champagne, Cory D; Houser, Dorian S; Fowler, Melinda A; Costa, Daniel P; Crocker, Daniel E

2012-08-01

Animals that endure prolonged periods of food deprivation preserve vital organ function by sparing protein from catabolism. Much of this protein sparing is achieved by reducing metabolic rate and suppressing gluconeogenesis while fasting. Northern elephant seals (Mirounga angustirostris) endure prolonged fasts of up to 3 mo at multiple life stages. During these fasts, elephant seals maintain high levels of activity and energy expenditure associated with breeding, reproduction, lactation, and development while maintaining rates of glucose production typical of a postabsorptive mammal. Therefore, we investigated how fasting elephant seals meet the requirements of glucose-dependent tissues while suppressing protein catabolism by measuring the contribution of glycogenolysis, glycerol, and phosphoenolpyruvate (PEP) to endogenous glucose production (EGP) during their natural 2-mo postweaning fast. Additionally, pathway flux rates associated with the tricarboxylic acid (TCA) cycle were measured specifically, flux through phosphoenolpyruvate carboxykinase (PEPCK) and pyruvate cycling. The rate of glucose production decreased during the fast (F(1,13) = 5.7, P = 0.04) but remained similar to that of postabsorptive mammals. The fractional contributions of glycogen, glycerol, and PEP did not change with fasting; PEP was the primary gluconeogenic precursor and accounted for ∼95% of EGP. This large contribution of PEP to glucose production occurred without substantial protein loss. Fluxes through the TCA cycle, PEPCK, and pyruvate cycling were higher than reported in other species and were the most energetically costly component of hepatic carbohydrate metabolism. The active pyruvate recycling fluxes detected in elephant seals may serve to rectify gluconeogeneic PEP production during restricted anaplerotic inflow in these fasting-adapted animals.

The time-walk of analog constant fraction discriminators using very fast scintillator detectors with linear and non-linear energy response

Energy Technology Data Exchange (ETDEWEB)

Regis, J.-M., E-mail: regis@ikp.uni-koeln.de [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); Rudigier, M.; Jolie, J.; Blazhev, A.; Fransen, C.; Pascovici, G.; Warr, N. [Institut fuer Kernphysik der Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

2012-08-21

The electronic {gamma}-{gamma} fast timing technique allows for direct nuclear lifetime determination down to the few picoseconds region by measuring the time difference between two coincident {gamma}-ray transitions. Using high resolution ultra-fast LaBr{sub 3}(Ce) scintillator detectors in combination with the recently developed mirror symmetric centroid difference method, nuclear lifetimes are measured with a time resolving power of around 5 ps. The essence of the method is to calibrate the energy dependent position (centroid) of the prompt response function of the setup which is obtained for simultaneously occurring events. This time-walk of the prompt response function induced by the analog constant fraction discriminator has been determined by systematic measurements using different photomultiplier tubes and timing adjustments of the constant fraction discriminator. We propose a universal calibration function which describes the time-walk or the combined {gamma}-{gamma} time-walk characteristics, respectively, for either a linear or a non-linear amplitude versus energy dependency of the scintillator detector output pulses.

Enabling fast charging – Battery thermal considerations

International Nuclear Information System (INIS)

Keyser, Matthew; Pesaran, Ahmad; Li, Qibo; Santhanagopalan, Shriram; Smith, Kandler

2017-01-01

Battery thermal barriers are reviewed with regards to extreme fast charging. Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature rise of the battery during extreme fast charging. If the battery thermal management system is not designed correctly, the temperature of the cells could reach abuse temperatures and potentially send the cells into thermal runaway. Furthermore, the cell and battery interconnect design needs to be improved to meet the lifetime expectations of the consumer. Each of these aspects is explored and addressed as well as outlining where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today’s market. Here, thermal management is not a limiting condition with regard to extreme fast charging, but many factors need to be addressed especially for future high specific energy density cells to meet U.S. Department of Energy cost and volume goals.

Fast breeder reactor safety : a perspective

International Nuclear Information System (INIS)

Kale, R.D.

1992-01-01

Taking into consideration India's limited reserves of natural and vast reserves of thorium, the fast reactor route holds a great promise for India's energy supply in future. The fast reactor fueled with 239 Pu/ 238 U (unused or depleted) produces (breeds) more fissionable fuel material 239 Pu than it consumes. Calculations show that a fast breeder reactor (FBR) increases energy potential of natural uranium by about 60 times. As the fast reactor can also convert 232 Th into 233 U which is a fissionable material, it can make India's thorium reserves a source of almost inexhaustible energy supply for a long time to come. Significant advantage of FBR plants cooled by sodium and their world-wide operating experience are reviewed. There are two main safety issues of FBR, one nuclear and the other non-nuclear. The nuclear issue concerns core disruptive accident and the non-nuclear one concerns the high chemical energy potential of sodium. These two issues are analysed and it is pointed that they are manageable by current design, construction and operational practices. Main findings of safety research during the last six to eight years in West European Countries and United States of America (US) are summarised. Three stage engineered safety provision incorporated into the design of the sodium cooled Fast Breeder Test Reactor (FBTR) commissioned at Kalpakkam are explained. The important design safety features of FBTR such as primary system containment, emergency core cooling, plant protection system, inherent safety features achieved through reactivity coefficients, and natural convection cooling are discussed. Theoretical analysis and experimental research in fast reactor safety carried out at the Indira Gandhi Centre for Atomic Research during the past some years are reviewed. (M.G.B.)

Fast High-Quality Noise

DEFF Research Database (Denmark)

Frisvad, Jeppe Revall; Wyvill, Geoff

2007-01-01

At the moment the noise functions available in a graphics programmer's toolbox are either slow to compute or they involve grid-line artifacts making them of lower quality. In this paper we present a real-time noise computation with no grid-line artifacts or other regularity problems. In other words......, we put a new tool in the box that computes fast high-quality noise. In addition to being free of artifacts, the noise we present does not rely on tabulated data (everything is computed on the fly) and it is easy to adjust quality vs. quantity for the noise. The noise is based on point rendering (like...... spot noise), but it extends to more than two dimensions. The fact that it is based on point rendering makes art direction of the noise much easier....

Fast food: unfriendly and unhealthy.

Science.gov (United States)

Stender, S; Dyerberg, J; Astrup, A

2007-06-01

Although nutrition experts might be able to navigate the menus of fast-food restaurant chains, and based on the nutritional information, compose apparently 'healthy' meals, there are still many reasons why frequent fast-food consumption at most chains is unhealthy and contributes to weight gain, obesity, type 2 diabetes and coronary artery disease. Fast food generally has a high-energy density, which, together with large portion sizes, induces over consumption of calories. In addition, we have found it to be a myth that the typical fast-food meal is the same worldwide. Chemical analyses of 74 samples of fast-food menus consisting of French fries and fried chicken (nuggets/hot wings) bought in McDonalds and KFC outlets in 35 countries in 2005-2006 showed that the total fat content of the same menu varies from 41 to 65 g at McDonalds and from 42 to 74 g at KFC. In addition, fast food from major chains in most countries still contains unacceptably high levels of industrially produced trans-fatty acids (IP-TFA). IP-TFA have powerful biological effects and may contribute to increased weight gain, abdominal obesity, type 2 diabetes and coronary artery disease. The food quality and portion size need to be improved before it is safe to eat frequently at most fast-food chains.

Enhanced emission of high-energy photons perpendicular to the reaction plane in α+Th reactions

International Nuclear Information System (INIS)

Tegner, P.; Marianski, B.; Morsch, H.P.; Rogge, M.; Bargholtz, C.; Decowski, P.; Zemlo, L.

1991-01-01

High-energy photon and neutron emission has been measured in coincidence with fission fragments in α+ 232 Th reactions at 170 MeV. From measurements parallel and perpendicular to the fission plane, anisotropies relative to the reaction plane were determined. The in-plane/out-of-plane intensity ratio is 0.72(7) for photons with energies above 20 MeV and 11(3) for neutrons at 35 MeV. The result for high-energy photons can be explained by nucleon-nucleon bremsstrahlung if the initial flow of nucleons has a correlation to the reaction plane similar to the one observed for fast neutrons

Energy spectra unfolding of fast neutron sources using the group method of data handling and decision tree algorithms

Energy Technology Data Exchange (ETDEWEB)

Hosseini, Seyed Abolfazl, E-mail: sahosseini@sharif.edu [Department of Energy Engineering, Sharif University of Technology, Tehran 8639-11365 (Iran, Islamic Republic of); Afrakoti, Iman Esmaili Paeen [Faculty of Engineering & Technology, University of Mazandaran, Pasdaran Street, P.O. Box: 416, Babolsar 47415 (Iran, Islamic Republic of)

2017-04-11

Accurate unfolding of the energy spectrum of a neutron source gives important information about unknown neutron sources. The obtained information is useful in many areas like nuclear safeguards, nuclear nonproliferation, and homeland security. In the present study, the energy spectrum of a poly-energetic fast neutron source is reconstructed using the developed computational codes based on the Group Method of Data Handling (GMDH) and Decision Tree (DT) algorithms. The neutron pulse height distribution (neutron response function) in the considered NE-213 liquid organic scintillator has been simulated using the developed MCNPX-ESUT computational code (MCNPX-Energy engineering of Sharif University of Technology). The developed computational codes based on the GMDH and DT algorithms use some data for training, testing and validation steps. In order to prepare the required data, 4000 randomly generated energy spectra distributed over 52 bins are used. The randomly generated energy spectra and the simulated neutron pulse height distributions by MCNPX-ESUT for each energy spectrum are used as the output and input data. Since there is no need to solve the inverse problem with an ill-conditioned response matrix, the unfolded energy spectrum has the highest accuracy. The {sup 241}Am-{sup 9}Be and {sup 252}Cf neutron sources are used in the validation step of the calculation. The unfolded energy spectra for the used fast neutron sources have an excellent agreement with the reference ones. Also, the accuracy of the unfolded energy spectra obtained using the GMDH is slightly better than those obtained from the DT. The results obtained in the present study have good accuracy in comparison with the previously published paper based on the logsig and tansig transfer functions. - Highlights: • The neutron pulse height distribution was simulated using MCNPX-ESUT. • The energy spectrum of the neutron source was unfolded using GMDH. • The energy spectrum of the neutron source was

Fast ion generation by a picosecond high-power laser

Czech Academy of Sciences Publication Activity Database

Badziak, J.; Parys, P.; Wolowski, J.; Hora, H.; Krása, Josef; Láska, Leoš; Rohlena, Karel

2005-01-01

Roč. 35, č. 1 (2005), s. 5-22 ISSN 0078-5466 R&D Projects: GA MŠk(CZ) ME 238 Grant - others:International Atomic Energy in Vienna(XE) 11535/RO; State Commitee for Scientific Research (KBN)(PL) 1 PO3B 082 19 and 1 PO3B 043 26 Institutional research plan: CEZ:AV0Z10100523 Keywords : fast ion * plasma * picosecond laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.459, year: 2005

"One-for-All" Strategy in Fast Energy Storage: Production of Pillared MOF Nanorod-Templated Positive/Negative Electrodes for the Application of High-Performance Hybrid Supercapacitor.

Science.gov (United States)

Qu, Chong; Liang, Zibin; Jiao, Yang; Zhao, Bote; Zhu, Bingjun; Dang, Dai; Dai, Shuge; Chen, Yu; Zou, Ruqiang; Liu, Meilin

2018-05-02

Currently, metal-organic frameworks (MOFs) are intensively studied as active materials for electrochemical energy storage applications due to their tunable structure and exceptional porosities. Among them, water stable pillared MOFs with dual ligands have been reported to exhibit high supercapacitor (SC) performance. Herein, the "One-for-All" strategy is applied to synthesize both positive and negative electrodes of a hybrid SC (HSC) from a single pillared MOF. Specifically, Ni-DMOF-TM ([Ni(TMBDC)(DABCO) 0.5 ], TMBDC: 2,3,5,6-tetramethyl-1,4-benzenedicarboxylic acid, DABCO: 1,4-diazabicyclo[2.2.2]-octane) nanorods are directly grown on carbon fiber paper (CFP) (denoted as CFP@TM-nanorods) with the help of triethylamine and function as the positive electrode of HSC under alkaline electrolyte. Meanwhile, calcinated N-doped hierarchical porous carbon nanorods (CFP@TM-NPCs) are produced and utilized as the negative counter-electrode from a one-step heat treatment of CFP@TM-nanorods. After assembling these two electrodes together to make a hybrid device, the TM-nanorods//TM-NPCs exhibit a wide voltage window of 1.5 V with a high sloping discharge plateau between 1-1.2 V, indicating its great potential for practical applications. This as-described "One-for-All" strategy is widely applicable and highly reproducible in producing MOF-based electrode materials for HSC applications, which shortens the gap between experimental synthesis and practical application of MOFs in fast energy storage. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Absorption of fast waves at moderate to high ion cyclotron harmonics on DIII-D

International Nuclear Information System (INIS)

Pinsker, R.I.; Porkolab, M.; Heidbrink, W.W.; Luo, Y.; Petty, C.C.; Prater, R.; Choi, M.; Schaffner, D.A.; Baity, F.W.; Fredd, E.; Hosea, J.C.; Harvey, R.W.; Smirnov, A.P.; Murakami, M.; Zeeland, M.A. Van

2006-01-01

The absorption of fast Alfven waves (FW) by ion cyclotron harmonic damping in the range of harmonics from 4th to 8th is studied theoretically and with experiments in the DIII-D tokamak. A formula for linear ion cyclotron absorption on ions with an arbitrary distribution function which is symmetric about the magnetic field is used to estimate the single-pass damping for various cases of experimental interest. It is found that damping on fast ions from neutral beam injection can be significant even at the 8th harmonic if the fast ion beta, the beam injection energy and the background plasma density are high enough and the beam injection geometry is appropriate. The predictions are tested in several L-mode experiments in DIII-D with FW power at 60 MHz and at 116 MHz. It is found that 4th and 5th harmonic absorption of the 60 MHz power on the beam ions can be quite strong, but 8th harmonic absorption of the 116 MHz power appears to be weaker than expected. The linear modelling predicts a strong dependence of the 8th harmonic absorption on the initial pitch-angle of the injected beam, which is not observed in the experiment. Possible explanations of the discrepancy are discussed

Technical development of high intensity proton accelerators in Japan Atomic Energy Research Institute (JAERI)

International Nuclear Information System (INIS)

Mizumoto, Motoharu

1995-01-01

Science and Technology Agency decided 'Options making extra gains of actinides and fission products (OMEGA)' and to promote the related researches. Also in JAERI, the research on the group separation method for separating transuranic elements, strontium and cesium from high level radioactive wastes has been carried out since the beginning of 1970s. Also the concept of the fast reactors using minor actinide mixture fuel is being established, and the accelerator annihilation treatment utilizing the nuclear spallation reaction by high energy protons has been examined. In this report, from the viewpoint of the application of accelerators to atomic energy field, the annihilation treatment method by the nuclear spallation reaction utilizing high intensity proton accelerators, the plan of the various engineering utilization of proton beam, and the development of accelerators in JAERI are described. The way of thinking on the annihilation treatment of radioactive waste, the system using fast neutrons, the way of thinking on the development of high intensity proton accelerator technology, the steps of the development, the research and development for constructing the basic technology accelerator, 2 MeV beam acceleration test, the basic technology accelerator utilization facility and so on are reported. (K.I.)

MONTE CARLO CALCULATION OF THE ENERGY RESPONSE OF THE NARF HURST-TYPE FAST- NEUTRON DOSIMETER

Energy Technology Data Exchange (ETDEWEB)

De Vries, T. W.

1963-06-15

The response function for the fast-neutron dosimeter was calculated by the Monte Carlo technique (Code K-52) and compared with a calculation based on the Bragg-Gray principle. The energy deposition spectra so obtained show that the response spectra become softer with increased incident neutron energy ahove 3 Mev. The K-52 calculated total res nu onse is more nearly constant with energy than the BraggGray response. The former increases 70 percent from 1 Mev to 14 Mev while the latter increases 135 percent over this energy range. (auth)

Plasma Photonic Devices for High Energy Density Science

International Nuclear Information System (INIS)

Kodama, R.

2005-01-01

High power laser technologies are opening a variety of attractive fields of science and technology using high energy density plasmas such as plasma physics, laboratory astrophysics, material science, nuclear science including medical applications and laser fusion. The critical issues in the applications are attributed to the control of intense light and enormous density of charged particles including efficient generation of the particles such as MeV electrons and protons with a current density of TA/cm2. Now these application possibilities are limited only by the laser technology. These applications have been limited in the control of the high power laser technologies and their optics. However, if we have another device consisted of the 4th material, i.e. plasma, we will obtain a higher energy density condition and explore the application possibilities, which could be called high energy plasma device. One of the most attractive devices has been demonstrated in the fast ignition scheme of the laser fusion, which is cone-guiding of ultra-intense laser light in to high density regions1. This is one of the applications of the plasma device to control the ultra-intense laser light. The other role of the devices consisted of transient plasmas is control of enormous energy-density particles in a fashion analogous to light control with a conventional optical device. A plasma fibre (5?m/1mm), as one example of the devices, has guided and deflected the high-density MeV electrons generated by ultra-intense laser light 2. The electrons have been well collimated with either a lens-like plasma device or a fibre-like plasma, resulting in isochoric heating and creation of ultra-high pressures such as Giga bar with an order of 100J. Plasmas would be uniquely a device to easily control the higher energy density particles like a conventional optical device as well as the ultra-intense laser light, which could be called plasma photonic device. (Author)

Fast ferroelectric phase shifters for energy recovery linacs

Directory of Open Access Journals (Sweden)

S. Yu Kazakov

2010-11-01

Full Text Available Fast phase shifters are described that use a novel barium strontium titanate ceramic that can rapidly change its dielectric constant as an external bias voltage is changed. These phase shifters promise to reduce by ∼10 times the power requirements for the rf source needed to drive an energy recovery linac (ERL. Such phase shifters will be coupled with superconducting radiofrequency cavities so as to tune them to compensate for phase instabilities, whether beam-driven or those caused by microphonics. The most promising design is presented, which was successfully cold tested and demonstrated a switching speed of ∼30  ns for 77 deg, corresponding to <0.5  ns per deg of rf phase. Other crucial issues (losses, phase shift values, etc. are discussed.

Adaptasi Fisiologis Selama Puasa (Physiological Adaptation During Fasting)

OpenAIRE

Fauziyati, Ana

2009-01-01

Fasting is an activity that has been done by people for long time. It is believed that fasting is good for health. During fasting people restrict food and water intake. How fasting makes body healthy and how body maintains the balance of energy and fluid during fasting are very interesting to learn. The objective of this review essay is to describe how the body maintain the balance of energy and fluid during fasting. During fasting, body lacks of food or energy intake, that means there is a r...

A fast fault protection based on direction of bus-side capacitor discharge current for a high-surety power supply

DEFF Research Database (Denmark)

Li, Haijin; Chen, Min; Yang, Boping

2017-01-01

A short-circuit fault protection strategy based on the direction of bus-side capacitor discharge current for a high-surety power supply, known as Super Uninterruptable Power Supply (Super UPS), is studied in this paper. It consists of multiple energy sources and storage components. All energy...... strategy is necessary to keep the uninterruptable power for the critical load. In this paper, the characteristics of the short-circuit fault are analyzed first. Then, a fast short-circuit fault locating and isolating strategy based on the direction of the discharge current of the busside capacitors...

Preliminary investigations on high energy electron beam tomography

Energy Technology Data Exchange (ETDEWEB)

Baertling, Yves; Hoppe, Dietrich; Hampel, Uwe

2010-12-15

In computed tomography (CT) cross-sectional images of the attenuation distribution within a slice are created by scanning radiographic projections of an object with a rotating X-ray source detector compound and subsequent reconstruction of the images from these projection data on a computer. CT can be made very fast by employing a scanned electron beam instead of a mechanically moving X-ray source. Now this principle was extended towards high-energy electron beam tomography with an electrostatic accelerator. Therefore a dedicated experimental campaign was planned and carried out at the Budker Institute of Nuclear Physics (BINP), Novosibirsk. There we investigated the capabilities of BINP's accelerators as an electron beam generating and scanning unit of a potential high-energy electron beam tomography device. The setup based on a 1 MeV ELV-6 (BINP) electron accelerator and a single detector. Besides tomographic measurements with different phantoms, further experiments were carried out concerning the focal spot size and repeat accuracy of the electron beam as well as the detector's response time and signal to noise ratio. (orig.)

Analysis of Russian transition scenarios to innovative nuclear energy system based on thermal and fast reactors with closed nuclear fuel cycle using INPRO methodology

International Nuclear Information System (INIS)

Kagramanyan, V.S.; Poplavskaya, E.V.; Korobeynikov, V.V.; Kalashnikov, A.G.; Moseev, A.L.; Korobitsyn, V.E.; Andreeva-Andrievskaya, L.N.

2011-01-01

This paper presents the results of the analysis of modeling of Russian nuclear energy (NE) scenarios on the basis of thermal and fast reactors with closed nuclear fuel cycle (NFC). Modeling has been carried out with use of CYCLE code (SSC RF IPPE's tool) designed for analysis of Nuclear Energy System (NES) with closed NFC taking into account plutonium and minor actinides (MA) isotopic composition change during multi-recycling of fuel in fast reactors. When considering fast reactor introduction scenarios, one of important questions is to define optimal time for their introduction and related NFC's facilities. Analysis of the results obtained has been fulfilled using the key INPRO indicators for sustainable energy development. It was shown that a delay in fast reactor introduction led to serious ecological, social and finally economic risks for providing energy security and sustainable development of Russia in long-term prospects and loss of knowledge and experience in mastering innovative technologies of fast reactors and related nuclear fuel cycle. (author)

Fast-food and full-service restaurant consumption among children and adolescents: effect on energy, beverage, and nutrient intake.

Science.gov (United States)

Powell, Lisa M; Nguyen, Binh T

2013-01-01

To examine the effect of fast-food and full-service restaurant consumption on total energy intake, dietary indicators, and beverage consumption. Individual-level fixed-effects estimation based on 2 nonconsecutive 24-hour dietary recalls. Nationally representative data from the 2003-2004, 2005-2006, and 2007-2008 National Health and Nutrition Examination Survey. Children aged 2 to 11 years (n = 4717) and adolescents aged 12 to 19 years (n = 4699). Daily total energy intake in kilocalories; intake of grams of sugar, total fat, saturated fat, and protein and milligrams of sodium; and total grams of sugar-sweetened beverages, regular soda, and milk consumed. Fast-food and full-service restaurant consumption, respectively, was associated with a net increase in daily total energy intake of 126.29 kcal and 160.49 kcal for children and 309.53 kcal and 267.30 kcal for adolescents and with higher intake of regular soda (73.77 g and 88.28 g for children and 163.67 g and 107.25 g for adolescents) and sugar-sweetened beverages generally. Fast-food consumption increased intake of total fat (7.03-14.36 g), saturated fat (1.99-4.64 g), and sugar (5.71-16.24 g) for both age groups and sodium (396.28 mg) and protein (7.94 g) for adolescents. Full-service restaurant consumption was associated with increases in all nutrients examined. Additional key findings were (1) adverse effects on diet were larger for lower-income children and adolescents and (2) among adolescents, increased soda intake was twice as large when fast food was consumed away from home than at home. Fast-food and full-service restaurant consumption is associated with higher net total energy intake and poorer diet quality.

Corrections on energy spectrum and scattering for fast neutron radiography at NECTAR facility

International Nuclear Information System (INIS)

Liu Shuquan; Thomas, Boucherl; Li Hang; Zou Yubin; Lu Yuanrong; Guo Zhiyu

2013-01-01

Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM-Ⅱ in Technische Universitaet Mounchen (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections. (authors)

Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

Science.gov (United States)

Liu, Shu-Quan; Bücherl, Thomas; Li, Hang; Zou, Yu-Bin; Lu, Yuan-Rong; Guo, Zhi-Yu

2013-11-01

Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM- II in Technische Universität München (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections.

Simultaneous Determination of Pyridoxine and Riboflavin in Energy Drinks by High-Performance Liquid Chromatography with Fluorescence Detection

Science.gov (United States)

Martí-Andre´s, P.; Escuder-Gilabert, L.; Martín-Biosca, Y.; Sagrado, S.; Medina-Herna´ndez, M.J.

2015-01-01

Energy drinks, as familiar consumer products, have been widely used in laboratory courses to help promote student interest, as well as to connect lecture concepts with laboratory work. Energy drinks contain B vitamins: pyridoxine (vitamin B6) and riboflavin (vitamin B2) of which amounts are high enough to be of concern. In this work, a fast and…

Purchase rates and energy content of nutritionally promoted and traditional fast foods purchased at lunchtime in Australia - a pilot study.

Science.gov (United States)

Atkinson, Louise F; Palmer, Michelle A

2012-03-01

Nutritionally promoted foods are now available at fast-food establishments. Little is known about their popularity, who is purchasing them, or their impact on dietary intake. Our study aimed to determine: how often nutritionally promoted fast foods were purchased; the demographic characteristics of people purchasing these foods; and if purchasing these foods resulted in reduced energy, and increased vegetable, content of lunches compared with those who purchased traditional fast foods. A survey collecting lunchtime fast-food purchases and demographic details was administered over two months. Nutritionally promoted products included the McDonalds' 'Heart Foundation Tick Approved' range and Subway's 'Six grams of fat or less' range. Energy and vegetable contents were estimated using information from fast-food companies' websites. Differences in demographics, energy and vegetable contents between individuals purchasing nutritionally promoted and traditional lunches were assessed using χ2 and t tests. Queensland, Australia. Lunchtime diners aged over 16 years at Subway and McDonalds. Surveys were collected from 927 respondents (58 % male, median age 25 (range 16-84) years; 73 % response rate). Only 3 % (n 24/910) of respondents who ordered a main option had purchased a nutritionally promoted item. Purchasers of nutritionally promoted foods were ∼13 years older, predominantly female (79 %), and more often reported involvement in a health-related profession (29 % v. 11 %) than purchasers of traditional foods (P < 0·05). Purchasers of nutritionally promoted foods ordered 1·5 fewer megajoules and 0·6 more vegetable servings than purchasers of traditional foods (P < 0·05). Nutritionally promoted fast foods may reduce lunchtime energy content, however these foods were infrequently chosen.

Chemical reactions induced by fast neutron irradiation

International Nuclear Information System (INIS)

Katsumura, Y.

1989-01-01

Here, several studies on fast neutron irradiation effects carried out at the reactor 'YAYOI' are presented. Some indicate a significant difference in the effect from those by γ-ray irradiation but others do not, and the difference changes from subject to subject which we observed. In general, chemical reactions induced by fast neutron irradiation expand in space and time, and there are many aspects. In the time region just after the deposition of neutron energy in the system, intermediates are formed densely and locally reflecting high LET of fast neutrons and, with time, successive reactions proceed parallel to dissipation of localized energy and to diffusion of the intermediates. Finally the reactions are completed in longer time region. If we pick up the effects which reserve the locality of the initial processes, a significant different effect between in fast neutron radiolysis and in γ-ray radiolysis would be derived. If we observe the products generated after dissipation and diffusion in longer time region, a clear difference would not be observed. Therefore, in order to understand the fast neutron irradiation effects, it is necessary to know the fundamental processes of the reactions induced by radiations. (author)

Two and three dimensional imaging of compact toroid plasmas using fast photography

International Nuclear Information System (INIS)

Englert, S.E.; Bell, D.E.; Coffey, S.K.

1992-01-01

As is discussed in a companion paper, Degnan el al, fast photography is used as a visual diagnostic tool for high energy plasma research at the Phillips Laboratory. Both, two dimensional and three dimensional images, are gathered by using nanosecond and microsecond range fast photography techniques. A set of microchannel plate cameras and a fast framing camera are used to record images of a compact toroid plasma during formation and acceleration stages. These images are subsequently digitized and enhanced to bring out detailed information of interest. This spatial information is combined with other diagnostic results as well as theoretical models in order to build a more complete picture of the fundamental physics associated with high-energy plasmas

The association of fast food consumption with poor dietary outcomes and obesity among children: is it the fast food or the remainder of the diet?

Science.gov (United States)

Poti, Jennifer M; Duffey, Kiyah J; Popkin, Barry M

2014-01-01

Although fast food consumption has been linked to adverse health outcomes, the relative contribution of fast food itself compared with the rest of the diet to these associations remains unclear. Our objective was to compare the independent associations with overweight/obesity or dietary outcomes for fast food consumption compared with dietary pattern for the remainder of intake. This cross-sectional analysis studied 4466 US children aged 2-18 y from NHANES 2007-2010. Cluster analysis identified 2 dietary patterns for the non-fast food remainder of intake: Western (50.3%) and Prudent. Multivariable-adjusted linear and logistic regression models examined the association between fast food consumption and dietary pattern for the remainder of intake and estimated their independent associations with overweight/obesity and dietary outcomes. Half of US children consumed fast food: 39.5% low-consumers (≤30% of energy from fast food) and 10.5% high-consumers (>30% of energy). Consuming a Western dietary pattern for the remainder of intake was more likely among fast food low-consumers (OR: 1.51; 95% CI: 1.24, 1.85) and high-consumers (OR: 2.21; 95% CI: 1.60, 3.05) than among nonconsumers. The remainder of diet was independently associated with overweight/obesity (β: 5.9; 95% CI: 1.3, 10.5), whereas fast food consumption was not, and the remainder of diet had stronger associations with poor total intake than did fast food consumption. Outside the fast food restaurant, fast food consumers ate Western diets, which might have stronger associations with overweight/obesity and poor dietary outcomes than fast food consumption itself. Our findings support the need for prospective studies and randomized trials to confirm these hypotheses.

Fast pyrolysis of biomass at high temperatures

DEFF Research Database (Denmark)

Trubetskaya, Anna

This Ph.D. thesis describes experimental and modeling investigations of fast high temperature pyrolysis of biomass. Suspension firing of biomass is widely used for power generation and has been considered as an important step in reduction of greenhouse gas emissions by using less fossil fuels. Fast...... to investigate the effects of operating parameters and biomass types on yields of char and soot, their chemistry and morphology as well as their reactivity using thermogravimetric analysis. The experimental study was focused on the influence of a wide range of operating parameters including heat treatment...... alkali metals. In this study, potassium lean pinewood (0.06 wt. %) produced the highest soot yield (9 and 7 wt. %) at 1250 and 1400°C, whereas leached wheat straw with the higher potassium content (0.3 wt. %) generated the lowest soot yield (2 and 1 wt. %). Soot yields of wheat and alfalfa straw at both...

Highly Efficient Green-Emitting Phosphors Ba2Y5B5O17 with Low Thermal Quenching Due to Fast Energy Transfer from Ce3+ to Tb3.

Science.gov (United States)

Xiao, Yu; Hao, Zhendong; Zhang, Liangliang; Xiao, Wenge; Wu, Dan; Zhang, Xia; Pan, Guo-Hui; Luo, Yongshi; Zhang, Jiahua

2017-04-17

This paper demonstrates a highly thermally stable and efficient green-emitting Ba 2 Y 5 B 5 O 17 :Ce 3+ , Tb 3+ phosphor prepared by high-temperature solid-state reaction. The phosphor exhibits a blue emission band of Ce 3+ and green emission lines of Tb 3+ upon Ce 3+ excitation in the near-UV spectral region. The effect of Ce 3+ to Tb 3+ energy transfer on blue to green emission color tuning and on luminescence thermal stability is studied in the samples codoped with 1% Ce 3+ and various concentrations (0-40%) of Tb 3+ . The green emission of Tb 3+ upon Ce 3+ excitation at 150 °C can keep, on average, 92% of its intensity at room temperature, with the best one showing no intensity decreasing up to 210 °C for 30% Tb 3+ . Meanwhile, Ce 3+ emission intensity only keeps 42% on average at 150 °C. The high thermal stability of the green emission is attributed to suppression of Ce 3+ thermal de-excitation through fast energy transfer to Tb 3+ , which in the green-emitting excited states is highly thermally stable such that no lifetime shortening is observed with raising temperature to 210 °C. The predominant green emission is observed for Tb 3+ concentration of at least 10% due to efficient energy transfer with the transfer efficiency approaching 100% for 40% Tb 3+ . The internal and external quantum yield of the sample with Tb 3+ concentration of 20% can be as high as 76% and 55%, respectively. The green phosphor, thus, shows attractive performance for near-UV-based white-light-emitting diodes applications.

Propagation of high-current fast electron beam in a dielectric target

International Nuclear Information System (INIS)

Klimo, O.; Debayle, A.; Tikhonchuk, V.T.

2006-01-01

Complete test of publication follows. A relativistic electron beam with very high current density may be produced during the interaction of a short high intensity laser pulse with a solid target. In Fast Ignition approach to Inertial Confinement Fusion, such beam is supposed to heat a part of the precompressed DT fuel pellet to the conditions of an efficient ignition. For successful implementation of Fast Ignition understanding the propagation and energy deposition of the beam is crucial. A number of processes, mostly associated with the return current, are dissipating the energy of the beam or inhibiting its collimated transport, namely the filamentation. Weibel, two-stream or the recently proposed ionization instability. Ionization instability may develop in a solid dielectric target due to the dependence of the propagation velocity of the beam on the beam density. To study the propagation of high current electron beam in dielectric target, we use a one-dimensional relativistic electrostatic simulation code based on the Particle in Cell method. The code includes ionization processes in dielectric material and collisions of newly generated cold electrons. The current density of the relativistic electron beam used in this work is in the range 3-300 GA/cm 2 , while its length roughly corresponds to the beam, produced by a 40 fs laser pulse. Propagation of the beam in the polyethylene target is studied. The code is complemented by an analytical model, which is applicable og a wider range of beam parameters that are currently beyond our computational possibilities. When the head of the beam enters the plastic target, electric field grows rapidly in consequence of the charge separation and it starts to ionize atoms. In the maximum of the field, which is less than 10% of the atomic field, the density of new free electrons is two orders of magnitude higher than the beam density, which is enough for the current neutralization. Cold electrons are accelerated by the field

Manipulation of rare isotope beams - from high to low energies

Energy Technology Data Exchange (ETDEWEB)

Bollen, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States)], E-mail: bollen@nscl.msu.edu; Campbell, C.; Chouhan, S.; Guenaut, C.; Lawton, D.; Marti, F. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Morrissey, D.J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Ottarson, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Pang, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Schwarz, S.; Zeller, A.F.; Zavodszky, P. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States)

2008-10-15

Projectile fragmentation above 50 MeV/u and in-flight separation is a powerful technique for the production and delivery of rare isotopes. The production is fast and chemistry independent, providing nuclides far away from the valley of beta stability and for a very large range of elements. These benefits can be maximized if the produced rare isotopes are made available also as low-energy beams (<15 MeV/u) and at rest. For this purpose the fast beams need to be slowed down and thermalized before being re-accelerated to the desired energy. This can be achieved with gas stopping techniques. This paper discusses various aspects of stopping fast rare isotope beams, including the development of a 'cyclotron gas stopper' that promises to overcome the limitations of present linear gas stopping schemes.

In-Pile Qualification of the Fast-Neutron-Detection-System

Science.gov (United States)

Fourmentel, D.; Villard, J.-F.; Destouches, C.; Geslot, B.; Vermeeren, L.; Schyns, M.

2018-01-01

In order to improve measurement techniques for neutron flux assessment, a unique system for online measurement of fast neutron flux has been developed and recently qualified in-pile by the French Alternative Energies and Atomic Energy Commission (CEA) in cooperation with the Belgian Nuclear Research Centre (SCK•ECEN). The Fast-Neutron-Detection-System (FNDS) has been designed to monitor accurately high-energy neutrons flux (E > 1 MeV) in typical Material Testing Reactor conditions, where overall neutron flux level can be as high as 1015 n.cm-2.s-1 and is generally dominated by thermal neutrons. Moreover, the neutron flux is coupled with a high gamma flux of typically a few 1015 γ.cm-2.s-1, which can be highly disturbing for the online measurement of neutron fluxes. The patented FNDS system is based on two detectors, including a miniature fission chamber with a special fissile material presenting an energy threshold near 1 MeV, which can be 242Pu for MTR conditions. Fission chambers are operated in Campbelling mode for an efficient gamma rejection. FNDS also includes a specific software that processes measurements to compensate online the fissile material depletion and to adjust the sensitivity of the detectors, in order to produce a precise evaluation of both thermal and fast neutron flux even after long term irradiation. FNDS has been validated through a two-step experimental program. A first set of tests was performed at BR2 reactor operated by SCK•CEN in Belgium. Then a second test was recently completed at ISIS reactor operated by CEA in France. FNDS proved its ability to measure online the fast neutron flux with an overall accuracy better than 5%.

Wearable supercapacitors on polyethylene terephthalate fabrics with good wash fastness and high flexibility

Science.gov (United States)

Wang, Guixia; Babaahmadi, Vahid; He, Nanfei; Liu, Yixin; Pan, Qin; Montazer, Majid; Gao, Wei

2017-11-01

All solid-state micro-supercapacitors (MSC) have emerged as attractive energy-storage units for portable and wearable electronics. Here, we describe a textile-based solid-state MSC via laser scribing of graphene oxide (GO) coatings on a flexible polyethylene terephthalate (PET) fabric. The laser-scribed graphene oxide layers (LGO) possess three-dimensionally porous structure suitable for electrochemical-double-layer formation. To improve the wash fastness and the flexibility of the as-prepared MSCs, glutaraldehyde (GA) was employed to crosslink the GO layers and PVA-gel electrolyte onto the PET fabric. The resultant all solid-state MSCs exhibited excellent flexibility, high areal specific capacitance (756 μF·cm-2 at 20 mV·s-1), and good rate capability when subject to bending and laundering. Furthermore, the MSC device showed a high power density of about 1.4 W·cm-3 and an energy density of 5.3 × 10-5 Wh·cm-3, and retained 98.3% of its initial capacitance after 1000 cycles at a current density of 0.5 mA·cm-2. This work is the first demonstration of in-plane MSCs on PET fabric surfaces with enhanced durability and flexibility.

High resolution fast neutron spectrometry without time-of-flight

International Nuclear Information System (INIS)

Evans, A.E.; Brandenberger, J.D.

1978-01-01

Performance tests of a spectrometer tube of the type developed by Cuttler and Shalev show that the measurement of fast neutron spectra with this device can be made with an energy resolution previously obtainable only in large time-of-flight facilities. In preliminary tests, resolutions of 16.4 keV for thermal neutrons and 30.9 keV for 1-MeV neutrons were obtained. A broad-window pulse-shape discrimination (PSD) system is used to remove from pulse-height distributions most of the continua due to 3 He-recoil events, noise, and wall effect. Use of PSD improved the energy resolution to 12.9 keV for thermal neutrons and 29.2 keV for 1-MeV neutrons. The detector is a viable tool for neutron research at nominally equipped accelerator laboratories

Fast T1 mapping of the brain at high field using Look-Locker and fast imaging.

Science.gov (United States)

Jiang, Ke; Zhu, Yanjie; Jia, Sen; Wu, Yin; Liu, Xin; Chung, Yiu-Cho

2017-02-01

This study aims to develop and evaluate a new method for fast high resolution T1 mapping of the brain based on the Look-Locker technique. Single-shot turboflash sequence with high temporal acceleration is used to sample the recovery of inverted magnetization. Multi-slice interleaved acquisition within one inversion slab is used to reduce the number of inversion pulses and hence SAR. Accuracy of the proposed method was studied using simulation and validated in phantoms. It was then evaluated in healthy volunteers and stroke patients. In-vivo results were compared to values obtained by inversion recovery fast spin echo (IR-FSE) and literatures. With the new method, T 1 values in phantom experiments agreed with reference values with median error map was acquired in 3.35s and the T1 maps of the whole brain were acquired in 2min with two-slice interleaving, with a spatial resolution of 1.1×1.1×4mm 3 . The T 1 values obtained were comparable to those measured with IR-FSE and those reported in literatures. These results demonstrated the feasibility of the proposed method for fast T1 mapping of the brain in both healthy volunteers and stroke patients at 3T. Copyright © 2016 Elsevier Inc. All rights reserved.

Biredox ionic liquids with solid-like redox density in the liquid state for high-energy supercapacitors.

Science.gov (United States)

Mourad, Eléonore; Coustan, Laura; Lannelongue, Pierre; Zigah, Dodzi; Mehdi, Ahmad; Vioux, André; Freunberger, Stefan A; Favier, Frédéric; Fontaine, Olivier

2017-04-01

Kinetics of electrochemical reactions are several orders of magnitude slower in solids than in liquids as a result of the much lower ion diffusivity. Yet, the solid state maximizes the density of redox species, which is at least two orders of magnitude lower in liquids because of solubility limitations. With regard to electrochemical energy storage devices, this leads to high-energy batteries with limited power and high-power supercapacitors with a well-known energy deficiency. For such devices the ideal system should endow the liquid state with a density of redox species close to the solid state. Here we report an approach based on biredox ionic liquids to achieve bulk-like redox density at liquid-like fast kinetics. The cation and anion of these biredox ionic liquids bear moieties that undergo very fast reversible redox reactions. As a first demonstration of their potential for high-capacity/high-rate charge storage, we used them in redox supercapacitors. These ionic liquids are able to decouple charge storage from an ion-accessible electrode surface, by storing significant charge in the pores of the electrodes, to minimize self-discharge and leakage current as a result of retaining the redox species in the pores, and to raise working voltage due to their wide electrochemical window.

Measurement of the physics properties of gas-cooled fast reactors in the zero energy reactor PROTEUS and analysis of the results

International Nuclear Information System (INIS)

Richmond, R.

1982-12-01

The main aim of the fast reactor physics measurements carried out in the zero energy reactor PROTEUS was to check the performance of data sets and calculation methods used in the design of fast breeder reactors. This allowed the accuracy of the power reactor calculations to be determined and enabled an assessment to be made of whether this accuracy would be sufficient to allow the design, construction and licensing of the GCFR power reactor. In order to carry out the physics measurements an existing zero energy reactor was converted to a form in which a central fast reactor lattice was surrounded by thermal zones to drive the reactor critical. One of the most important measuring techniques used to check the performance of data sets and calculation methods was the determination of reaction rate ratios and, by using an appropriate range of nuclides, it was possible to obtain a detailed picture covering 70% of reactions taking place in the central part of the fast reactor zone and with an accuracy of +-1.5% in a typical ratio. A further technique used during the work on GCFR-PROTEUS was the measurement of neutron spectrum which was carried out in a wide range of environments and, in the later stages of the work, covered the energy range from 9 keV to 2.3 MeV. These measurements, in particular, indicated significant errors in the FGL4 scattering cross-sections. A third technique, which was developed to a high degree of accuracy, was the measurement of reactivity worths. This was used in measurements of the worths of small samples and also in the application of the null reactivity technique to determine k-infinity and hence the absorption cross-sections of reactor structural materials. (Auth.)

Estimation of nuclear destruction in high energy nucleus-nucleus interactions

International Nuclear Information System (INIS)

Uzhinskij, V.V.

1995-01-01

It is assumed that: 1) a projectile particle invokes into target nucleus a cascade of quark-gluon exchanges; 2) the nucleons involved in the cascade are ejected from the nucleus which leads to the nuclear destruction. On these bases a simple model to estimate the nuclear destruction at the fast stage of the interaction is proposed. The allowed region of the model parameters is determined at the proton-emulsion high-energy interaction data analysis: an analysis of gold interactions with nuclei at an energy of 600 MeV/nucleon fixes the parameter values. The distributions on the energy in zero degree calorimeter (T ZDC ) in the interactions of Si+Al, Cu, Pb (14 GeV/nucleon) and Au+Au (10 GeV/nucleon) calculated in the framework of the model and in the cascade-evaporation model (CEM) are presented. The proposed model describes the nuclear destruction at intermediate and high energies better than CEM does. The estimation of the average values of impact parameter and the number of intra-nuclear collisions for Au+Au interactions in the events with different T ZDC is given. 34 refs., 11 figs

VERY HIGH ENERGY OBSERVATIONS OF GAMMA-RAY BURSTS WITH STACEE

International Nuclear Information System (INIS)

Jarvis, A.; Ong, R. A.; Ball, J.; Carson, J. E.; Zweerink, J.; Williams, D. A.; Aune, T.; Covault, C. E.; Driscoll, D. D.; Fortin, P.; Mukherjee, R.; Gingrich, D. M.; Hanna, D. S.; Kildea, J.; Lindner, T.; Mueller, C.; Ragan, K.

2010-01-01

Gamma-ray bursts (GRBs) are the most powerful explosions known in the universe. Sensitive measurements of the high-energy spectra of GRBs can place important constraints on the burst environments and radiation processes. Until recently, there were no observations during the first few minutes of GRB afterglows in the energy range between 30 GeV and ∼1 TeV. With the launch of the Swift GRB Explorer in late 2004, GRB alerts and localizations within seconds of the bursts became available. The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) was a ground-based, gamma-ray telescope with an energy threshold of ∼150 GeV for sources at zenith. At the time of Swift's launch, STACEE was in a rare position to provide >150 GeV follow-up observations of GRBs as fast as three minutes after the burst alert. In addition, STACEE performed follow-up observations of several GRBs that were localized by the HETE-2 and INTEGRAL satellites. Between 2002 June and 2007 July, STACEE made follow-up observations of 23 GRBs. Upper limits are placed on the high-energy gamma-ray fluxes from 21 of these bursts.

Fast switching wideband rectifying circuit for future RF energy harvesting

Science.gov (United States)

Asmeida, Akrem; Mustam, Saizalmursidi Md; Abidin, Z. Z.; Ashyap, A. Y. I.

2017-09-01

This paper presents the design and simulation of fast switching microwave rectifying circuit for ultra wideband patch antenna over a dual-frequency band (1.8 GHz for GSM and 2.4 GHz for ISM band). This band was chosen due to its high signal availability in the surrounding environment. New rectifying circuit topology with pair-matching trunks is designed using Advanced Design System (ADS) software. These trunks are interfaced with power divider to achieve good bandwidth, fast switching and high efficiency. The power divider acts as a good isolator between the trunks and its straightforward design structure makes it a good choice for a single feed UWB antenna. The simulated results demonstrate that the maximum output voltage is 2.13 V with an input power of -5 dBm. Moreover, the rectifier offers maximum efficiency of 86% for the input power of -5 dBm at given band, which could easily power up wireless sensor networks (WSN) and other small devices sufficiently.

Analytical model for fast-shock ignition

International Nuclear Information System (INIS)

Ghasemi, S. A.; Farahbod, A. H.; Sobhanian, S.

2014-01-01

A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI). The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ∼4.5 MeV, the electrons effectively reach the central part of the fuel. To evaluate more realistically the performance of FSI approach, we have used a quasi-two temperature electron energy distribution function of Strozzi (2012) and fast ignitor energy formula of Bellei (2013) that are consistent with 3D PIC simulations for different values of fast ignitor laser wavelength and coupling efficiency. The general advantages of fast-shock ignition in comparison with the shock ignition can be estimated to be better than 1.3 and it is seen that the best results can be obtained for the fuel mass around 1.5 mg, fast ignitor laser wavelength ∼0.3  micron and the shock ignitor energy weight factor about 0.25

Thermal Implications for Extreme Fast Charge

Energy Technology Data Exchange (ETDEWEB)

Keyser, Matthew A [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-08-14

Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature rise of the battery during extreme fast charging. If the battery thermal management system is not designed correctly, the temperature of the cells could reach abuse temperatures and potentially send the cells into thermal runaway. Furthermore, the cell and battery interconnect design needs to be improved to meet the lifetime expectations of the consumer. Each of these aspects is explored and addressed as well as outlining where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today's market. Thermal management is not a limiting condition with regard to extreme fast charging, but many factors need to be addressed especially for future high specific energy density cells to meet U.S. Department of Energy cost and volume goals.

Highly efficient generation of ultraintense high-energy ion beams using laser-induced cavity pressure acceleration

Energy Technology Data Exchange (ETDEWEB)

Badziak, J.; Jablonski, S.; Raczka, P. [Institute of Plasma Physics and Laser Microfusion, Euratom Association, 01-497 Warsaw (Poland)

2012-08-20

Results of particle-in-cell (PIC) simulations of fast ion generation in the recently proposed laser-induced cavity pressure acceleration (LICPA) scheme in which a picosecond circularly polarized laser pulse of intensity {approx}10{sup 21} W/cm{sup 2} irradiates a carbon target placed in a cavity are presented. It is shown that due to circulation of the laser pulse in the cavity, the laser-ions energy conversion efficiency in the LICPA scheme is more than twice as high as that for the conventional (without a cavity) radiation pressure acceleration scheme and a quasi-monoenergetic carbon ion beam of the mean ion energy {approx}0.5 GeV and the energy fluence {approx}0.5 GJ/cm{sup 2} is produced with the efficiency {approx}40%. The results of PIC simulations are found to be in fairly good agreement with the predictions of the generalized light-sail model.

Production of light fragments in hA collisions at high energies

International Nuclear Information System (INIS)

Braun, M.A.; Vechernin, V.V.

1988-12-01

Production of fast relativistic light fragments in hA collisions at high energies is considered. Direct coalescence of produced nucleons into fragments is shown to be the main mechanism for fragment production. The influence of the nuclear field is small and is not described by the well-known Butler-Pearson formulas. The coalescence coefficient strongly depends on the angle and on the behaviour of the fragment wave function at small internucleon distances. (author). 14 refs, 7 figs

Ultra fast shutter driven by pulsed high current

International Nuclear Information System (INIS)

Zeng Jiangtao; Sun Fengju; Qiu Aici; Yin Jiahui; Guo Jianming; Chen Yulan

2005-01-01

Radiation simulation utilizing plasma radiation sources (PRS) generates a large number of undesirable debris, which may damage the expensive diagnosing detectors. An ultra fast shutter (UFS) driven by pulsed high current can erect a physical barrier to the slowly moving debris after allowing the passage of X-ray photons. The UFS consists of a pair of thin metal foils twisting the parallel axes in a Nylon cassette, compressed with an outer magnetic field, generated from a fast capacitor bank, discharging into a single turn loop. A typical capacitor bank is of 7.5 μF charging voltages varying from 30 kV to 45 kV, with corresponding currents of approximately 90 kA to 140 kA and discharging current periods of approximately 13.1 μs. A shutter closing time as fast as 38 microseconds has been obtained with an aluminium foil thickness of 100 micrometers and a cross-sectional area of 15 mm by 20 mm. The design, construction and the expressions of the valve-closing time of the UFS are presented along with the measured results of valve-closing velocities. (authors)

Fast GPU-based spot extraction for energy-dispersive X-ray Laue diffraction

International Nuclear Information System (INIS)

Alghabi, F.; Schipper, U.; Kolb, A.; Send, S.; Abboud, A.; Pashniak, N.; Pietsch, U.

2014-01-01

This paper describes a novel method for fast online analysis of X-ray Laue spots taken by means of an energy-dispersive X-ray 2D detector. Current pnCCD detectors typically operate at some 100 Hz (up to a maximum of 400 Hz) and have a resolution of 384 × 384 pixels, future devices head for even higher pixel counts and frame rates. The proposed online data analysis is based on a computer utilizing multiple Graphics Processing Units (GPUs), which allow for fast and parallel data processing. Our multi-GPU based algorithm is compliant with the rules of stream-based data processing, for which GPUs are optimized. The paper's main contribution is therefore an alternative algorithm for the determination of spot positions and energies over the full sequence of pnCCD data frames. Furthermore, an improved background suppression algorithm is presented.The resulting system is able to process data at the maximum acquisition rate of 400 Hz. We present a detailed analysis of the spot positions and energies deduced from a prior (single-core) CPU-based and the novel GPU-based data processing, showing that the parallel computed results using the GPU implementation are at least of the same quality as prior CPU-based results. Furthermore, the GPU-based algorithm is able to speed up the data processing by a factor of 7 (in comparison to single-core CPU-based algorithm) which effectively makes the detector system more suitable for online data processing

A Fast General-Purpose Clustering Algorithm Based on FPGAs for High-Throughput Data Processing

CERN Document Server

Annovi, A; The ATLAS collaboration; Castegnaro, A; Gatta, M

2012-01-01

We present a fast general-purpose algorithm for high-throughput clustering of data ”with a two dimensional organization”. The algorithm is designed to be implemented with FPGAs or custom electronics. The key feature is a processing time that scales linearly with the amount of data to be processed. This means that clustering can be performed in pipeline with the readout, without suffering from combinatorial delays due to looping multiple times through all the data. This feature makes this algorithm especially well suited for problems where the data has high density, e.g. in the case of tracking devices working under high-luminosity condition such as those of LHC or Super-LHC. The algorithm is organized in two steps: the first step (core) clusters the data; the second step analyzes each cluster of data to extract the desired information. The current algorithm is developed as a clustering device for modern high-energy physics pixel detectors. However, the algorithm has much broader field of applications. In ...

Laser - driven high - energy ions and their application to inertial confinement fusion

International Nuclear Information System (INIS)

Borghesi, M.

2007-01-01

The acceleration of high-energy ion beams (up to several tens of MeV per nucleon) following the interaction of short and intense laser pulses with solid targets has been one of the most important results of recent laser-plasma research [1]. The acceleration is driven by relativistic electrons, which acquire energy directly from the laser pulse and set up extremely large (∼TV/m) space charge fields at the target interfaces. The properties of laser-driven ion beams (high brightness and laminarity, high-energy cut-off, ultrashort burst duration) distinguish them from lower energy ions accelerated in earlier experiments at moderate laser intensities, and compare favourably with those of 'conventional' accelerator beams. In view of these properties, laser-driven ion beams can be employed in a number of innovative applications in the scientific, technological and medical areas. We will discuss in particular aspects of interest to their application in an Inertial Confinement Fusion context. Laser-driven protons are indeed being considered as a possible trigger for Fast Ignition of a precompressed fuel.[2] Recent results relating to the optimization of beam energy and focusing will be presented. These include the use of laser-driven impulsive fields for proton beam collimation and focusing [3], and the investigation of acceleration in presence of finite-scale plasma gradient. Proposed target developments enabling proton production at high repetition rate will also be discussed. Another important area of application of proton beams is diagnostic use in a particle probing arrangement for detection of density non-homogeneities [4] and electric/magnetic fields [5]. We will discuss the use of laser-driven proton beams for the diagnosis of magnetic and electric fields in planar and hohlraum targets and for the detection of fields associated to relativistic electron propagation through dense matter, an issue of high relevance for electron driven Fast Ignition. [1] M

Low fasting low high-density lipoprotein and postprandial lipemia

Directory of Open Access Journals (Sweden)

Sorodila Konstandina

2004-07-01

Full Text Available Abstract Background Low levels of high density lipoprotein (HDL cholesterol and disturbed postprandial lipemia are associated with coronary heart disease. In the present study, we evaluated the variation of triglyceride (TG postprandially in respect to serum HDL cholesterol levels. Results Fifty two Greek men were divided into 2 main groups: a the low HDL group (HDL p = 0.002. The low HDL group had significantly higher TG at 4, 6 and 8 h postprandially compared to the controls (p = 0.006, p = 0.002, and p p = 0.017 compared to the matched-control group. ROC analysis showed that fasting TG ≥ 121 mg/dl have 100% sensitivity and 81% specificity for an abnormal TG response (auc = 0.962, p Conclusions The delayed TG clearance postprandially seems to result in low HDL cholesterol even in subjects with low fasting TG. The fasting TG > 121 mg/dl are predictable for abnormal response to fatty meal.

Ion optical layout and focusing elements for the high energy part of the SNQ-LINAC

International Nuclear Information System (INIS)

Hacker, H.U.; Hardt, A.H.; Martin, S.A.

1984-01-01

The ionoptical layout and the design of the focusing elements for the high energy part (HELA) of the SNQ-LINAC is discussed. A simple FOOD-structure for the single cell LINAC part has been optimized. Tolerances are discussed. Optical, electrical and magnetic data of a fast Kicker system is given. (orig.)

Upgrading the ATLAS Fast Calorimeter Simulation

CERN Document Server

Hubacek, Zdenek; The ATLAS collaboration

2016-01-01

Many physics and performance studies with the ATLAS detector at the Large Hadron Collider require very large samples of simulated events, and producing these using the full GEANT4 detector simulation is highly CPU intensive. Often, a very detailed detector simulation is not needed, and in these cases fast simulation tools can be used to reduce the calorimeter simulation time by a few orders of magnitude. In ATLAS, a fast simulation of the calorimeter systems was developed, called Fast Calorimeter Simulation (FastCaloSim). It provides a parametrized simulation of the particle energy response at the calorimeter read-out cell level. It is interfaced to the standard ATLAS digitization and reconstruction software, and can be tuned to data more easily than with GEANT4. The original version of FastCaloSim has been very important in the LHC Run-1, with several billion events simulated. An improved parametrisation is being developed, to eventually address shortcomings of the original version. It incorporates developme...

The new ATLAS Fast Calorimeter Simulation

CERN Document Server

Dias, Flavia; The ATLAS collaboration

2016-01-01

A very large number of simulated events is required for physics and performance studies with the ATLAS detector at the Large Hadron Collider. Producing these with the full GEANT4 detector simulation is highly CPU intensive. As a very detailed detector simulation is not always required, fast simulation tools have been developed to reduce the calorimeter simulation time by a few orders of magnitude. The fast simulation of ATLAS for the calorimeter systems used in Run 1, called Fast Calorimeter Simulation (FastCaloSim), provides a parameterized simulation of the particle energy response at the calorimeter read-out cell level. It is then interfaced to the ATLAS digitization and reconstruction software. In Run 1, about 13 billion events were simulated in ATLAS, out of which 50% were produced using fast simulation. For Run 2, a new parameterisation is being developed to improve the original version: It incorporates developments in geometry and physics lists of the last five years and benefits from knowledge acquire...

Analysis of cavity effect on space- and time-dependent fast and thermal neutron energy spectra

International Nuclear Information System (INIS)

Kudo, Katsuhisa; Narita, Masakuni; Ozawa, Yasutomo.

1975-01-01

The effects of the presence of a central cavity on the space- and time-dependent neutron energy spectra in both thermal and fast neutron systems are analyzed theoretically with use made of the multi-group one-dimensional time-dependent Ssub(n) method. The thermal neutron field is also analyzed for the case of a fundamental time eigenvalue problem with the time-dependent P 1 approximation. The cavity radius is variable, and the system radius for graphite is 120 cm and for the other materials 7 cm. From the analysis of the time-dependent Ssub(n) calculations in the non-multiplying systems of polythene, light water and graphite, cavity heating is the dominant effect for the slowing-down spectrum in the initial period following fast neutron burst, and when the slowing-down spectrum comes into the thermal energy region, cavity heating shifts to cavity cooling. In the multiplying system of 235 U, cavity cooling also takes place as the spectrum approaches equilibrium after the fast neutron burst is injected. The mechanism of cavity cooling is explained analytically for the case of thermal neutron field to illustrate its physical aspects, using the time-dependent P 1 approximation. An example is given for the case of light water. (auth.)

A novel integrated renewable energy system modelling approach, allowing fast FPGA controller prototyping

DEFF Research Database (Denmark)

Teodorescu, Remus; Ruiz, Alberto Parera; Cirstea, Marcian

2008-01-01

The paper describes a new holistic approach to the modeling of integrated renewable energy systems. The method is using the DK5 modeling/design environment from Celoxica and is based on the new Handel-C programming language. The goal of the work carried out was to achieve a combined model...... containing a Xilinx Spartan II FPGA and was successfully experimentally tested. This approach enables the design and fast hardware implementation of efficient controllers for Distributed Energy Resource (DER) hybrid systems....... of a photovoltaic energy system and a wind power system, which would allow an optimized holistic digital control system design, followed by rapid prototyping of the controller into a single Field Programmable Gate Array (FPGA). Initially, the system was simulated using Matlab / Simulink, to create a reference...

Ghrelin mimics fasting to enhance human hedonic, orbitofrontal cortex, and hippocampal responses to food.

Science.gov (United States)

Goldstone, Anthony P; Prechtl, Christina G; Scholtz, Samantha; Miras, Alexander D; Chhina, Navpreet; Durighel, Giuliana; Deliran, Seyedeh S; Beckmann, Christian; Ghatei, Mohammad A; Ashby, Damien R; Waldman, Adam D; Gaylinn, Bruce D; Thorner, Michael O; Frost, Gary S; Bloom, Stephen R; Bell, Jimmy D

2014-06-01

Ghrelin, which is a stomach-derived hormone, increases with fasting and energy restriction and may influence eating behaviors through brain hedonic reward-cognitive systems. Therefore, changes in plasma ghrelin might mediate counter-regulatory responses to a negative energy balance through changes in food hedonics. We investigated whether ghrelin administration (exogenous hyperghrelinemia) mimics effects of fasting (endogenous hyperghrelinemia) on the hedonic response and activation of brain-reward systems to food. In a crossover design, 22 healthy, nonobese adults (17 men) underwent a functional magnetic resonance imaging (fMRI) food-picture evaluation task after a 16-h overnight fast (Fasted-Saline) or after eating breakfast 95 min before scanning (730 kcal, 14% protein, 31% fat, and 55% carbohydrate) and receiving a saline (Fed-Saline) or acyl ghrelin (Fed-Ghrelin) subcutaneous injection before scanning. One male subject was excluded from the fMRI analysis because of excess head motion, which left 21 subjects with brain-activation data. Compared with the Fed-Saline visit, both ghrelin administration to fed subjects (Fed-Ghrelin) and fasting (Fasted-Saline) significantly increased the appeal of high-energy foods and associated orbitofrontal cortex activation. Both fasting and ghrelin administration also increased hippocampus activation to high-energy- and low-energy-food pictures. These similar effects of endogenous and exogenous hyperghrelinemia were not explicable by consistent changes in glucose, insulin, peptide YY, and glucagon-like peptide-1. Neither ghrelin administration nor fasting had any significant effect on nucleus accumbens, caudate, anterior insula, or amygdala activation during the food-evaluation task or on auditory, motor, or visual cortex activation during a control task. Ghrelin administration and fasting have similar acute stimulatory effects on hedonic responses and the activation of corticolimbic reward-cognitive systems during food

Experimental study of hot electrons propagation and energy deposition in solid or laser-shock compressed targets: applications to fast igniter

International Nuclear Information System (INIS)

Pisani, F.

2000-02-01

In the fast igniter scheme, a recent approach proposed for the inertial confinement fusion, the idea is to dissociate the fuel ignition phase from its compression. The ignition phase would be then achieved by means of an external energy source: a fast electron beam generated by the interaction with an ultra-intense laser. The main goal of this work is to study the mechanisms of the hot electron energy transfer to the compressed fuel. We intent in particular to study the role of the electric and collisional effects involved in the hot electron propagation in a medium with properties similar to the compressed fuel. We carried out two experiments, one at the Vulcan laser facility (England) and the second one at the new LULI 100 TW laser (France). During the first experiment, we obtained the first results on the hot electron propagation in a dense and hot plasma. The innovating aspect of this work was in particular the use of the laser-shock technique to generate high pressures, allowing the strongly correlated and degenerated plasma to be created. The role of the electric and magnetic effects due to the space charge associated with the fast electron beam has been investigated in the second experiment. Here we studied the propagation in materials with different electrical characteristics: an insulator and a conductor. The analysis of the results showed that only by taking into account simultaneously the two propagation mechanisms (collisions and electric effects) a correct treatment of the energy deposition is possible. We also showed the importance of taking into account the induced modifications due to the electrons beam crossing the target, especially the induced heating. (author)

Role of focused assessment with sonography for trauma as a screening tool for blunt abdominal trauma in young children after high energy trauma

NARCIS (Netherlands)

Tummers, W.; Schuppen, J.V. (J Van); H.R. Langeveld-Benders (Hester); Wilde, J.; Banderker, E.; Van, A.

2016-01-01

textabstractBackground: The objective of the study was to review the utility of focused assessement with sonography for trauma (FAST) as a screening tool for blunt abdominal trauma (BAT) in children involved in high energy trauma (HET), and to determine whether a FAST could replace computed

Scintillating liquid xenon calorimeter for precise electron/photon/jet physics at high energy high luminosity hadron colliders

International Nuclear Information System (INIS)

Chen, M.; Luckey, D.; Pelly, D.; Shotkin, S.; Sumorok, K.; Wadsworth, B.; Yan, X.J.; You, C.; Zhang, X.; Chen, E.G.; Gaudreau, M.P.J.; Montgomery, D.B.; Sullivan, J.D.; Bolozdynya, A.; Chernyshev, V.; Goritchev, P.; Khovansky, V.; Kouchenkov, A.; Kovalenko, A.; Lebedenko, V.; Vinogradov, V.A.; Epstein, V.; Zeldovich, S.; Krasnokutsky, R.; Shuvalov, R.; Aprile, E.; Mukherjee, R.; Suzuki, M.; Moulsen, M.; Sugimoto, S.; Okada, K.; Fujino, T.; Matsuda, T.; Miyajima, M.; Doke, T.; Kikuchi, J.; Hitachi, A.; Kashiwagi, T.; Nagasawa, Y.; Ichinose, H.; Ishida, N.; Nakasugi, T.; Ito, T.; Masuda, K.; Shibamura, E.; Wallraff, W.; Vivargent, M.; Mutterer, M.; Chen, H.S.; Tang, H.W.; Tung, K.L.; Ding, H.L.; Takahashi, T.

1990-01-01

The authors use αs well as e, π, p, d and heavy ion beams to test prototype scintillating liquid xenon detectors, with large UV photodiodes and fast amplifiers submersed directly in liquid xenon. The data show very large photoelectron yields (10 7 /GeV) and high energy resolution (σ(E)/E 1.6 GeV). The α spectra are stable over long term and can be used to calibrate the detectors. Full size liquid xenon detectors have been constructed, to study cosmic μ's and heavy ions. The authors report the progress on the design and construction of the 5 x 5 and 11 x 11 cell liquid xenon detectors which will be tested in high energy beams to determine the e/π ratio. The authors describe the design and the unique properties of the proposed scintillating LXe calorimeter for the SSC

Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

Science.gov (United States)

Schroeder, J L; Thomson, W; Howard, B; Schell, N; Näslund, L-Å; Rogström, L; Johansson-Jõesaar, M P; Ghafoor, N; Odén, M; Nothnagel, E; Shepard, A; Greer, J; Birch, J

2015-09-01

We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

R and D programme on generation IV nuclear energy systems: the high temperatures gas-cooled reactors

International Nuclear Information System (INIS)

Carre, F.; Fiorini, G.L.; Billot, P.; Anzieu, P.; Brossard, P.

2005-01-01

The Generation IV Technology Roadmap selected, among others, a sequenced development of advanced high temperature gas cooled reactors as one of the main focus for R and D on future nuclear energy systems. The selection of this research objective originates both from the significance of high temperature and fast neutrons for nuclear energy to meet the needs for a sustainable development for the medium-long term (2020/2030 and beyond), and from the significant common R and D pathway that supports both medium term industrial projects and more advanced versions of gas cooled reactors. The first step of the 'Gas Technology Path' aims to support the development of a modular HTR to meet specific international market needs around 2020. The second step is a Very High Temperature Reactor - VHTR (>950 C) - to efficiently produce hydrogen through thermo-chemical or electro-chemical water splitting or to generate electricity with an efficiency above 50%, among other applications of high temperature nuclear heat. The third step of the Path is a Gas Fast Reactor - GFR - that features a fast-spectrum helium-cooled reactor and closed fuel cycle, with a direct or indirect thermodynamic cycle for electricity production and full recycle of actinides. Hydrogen production is also considered for the GFR. The paper succinctly presents the R and D program currently under definition and partially launched within the Generation IV International Forum on this consistent set of advanced gas cooled nuclear systems. (orig.)

Recent Developments in High-Harmonic Fast Wave Physics in NSTX

International Nuclear Information System (INIS)

LeBlanc, B.P.; Bell, R.E.; Bonoli, P.; Harvey, R.; Heidbrink, W.W.; Hosea, J.C.; Kaye, S.M.; Liu, D.; Maingi, R.; Medley, S.S.; Ono, M.; Podesta, M.; Phillips, C.K.; Ryan, P.M.; Roquemore, A.L.; Taylor, G.; Wilson, J.R.

2010-01-01

Understanding the interaction between ion cyclotron range of frequency (ICRF) fast waves and the fast-ions created by neutral beam injection (NBI) is critical for future devices such as ITER, which rely on a combination ICRF and NBI. Experiments in NSTX which use 30 MHz High-Harmonic Fast-Wave (HHFW) ICRF and NBI heating show a competition between electron heating via Landau damping and transit-time magnetic pumping, and radio-frequency wave acceleration of NBI generated fast ions. Understanding and mitigating some of the power loss mechanisms outside the last closed flux surface (LCFS) has resulted in improved HHFW heating inside the LCFS. Nevertheless a significant fraction of the HHFW power is diverted away from the enclosed plasma. Part of this power is observed locally on the divertor. Experimental observations point toward the radio-frequency (RF) excitation of surface waves, which disperse wave power outside the LCFS, as a leading loss mechanism. Lithium coatings lower the density at the antenna, thereby moving the critical density for perpendicular fast-wave propagation away from the antenna and surrounding material surfaces. Visible and infrared imaging reveal flows of RF power along open field lines into the divertor region. In L-mode -- low average NBI power -- conditions, the fast-ion D-alpha (FIDA) diagnostic measures a near doubling and broadening of the density profile of the upper energetic level of the fast ions concurrent with the presence of HHFW power launched with k// = -8m-1. We are able to heat NBI-induced H-mode plasmas with HHFW. The captured power is expected to be split between absorption by the electrons and absorption by the fast ions, based on TORIC calculation. In the case discussed here the Te increases over the whole profile when ∼2MW of HHFW power with antenna k// = 13m-1 is applied after the H-mode transition. But somewhat unexpectedly fast-ion diagnostics do not observe a change between the HHFW heated NBI discharge and the

Two-Level Control for Fast Electrical Vehicle Charging Stations with Multi Flywheel Energy Storage System

DEFF Research Database (Denmark)

SUN, BO; Dragicevic, Tomislav; Vasquez, Juan Carlos

2015-01-01

This paper applies a hierarchical control for a fast charging station (FCS) composed of paralleled PWM rectifier and dedicated paralleled multiple flywheel energy storage systems (FESSs), in order to mitigate peak power shock on grid caused by sudden connection of electrical vehicle (EV) chargers...

Investigation of the heavy nuclei fission with anomalously high values of the fission fragments total kinetic energy

Science.gov (United States)

Khryachkov, Vitaly; Goverdovskii, Andrei; Ketlerov, Vladimir; Mitrofanov, Vecheslav; Sergachev, Alexei

2018-03-01

Binary fission of 232Th and 238U induced by fast neutrons were under intent investigation in the IPPE during recent years. These measurements were performed with a twin ionization chamber with Frisch grids. Signals from the detector were digitized for further processing with a specially developed software. It results in information of kinetic energies, masses, directions and Bragg curves of registered fission fragments. Total statistics of a few million fission events were collected during each experiment. It was discovered that for several combinations of fission fragment masses their total kinetic energy was very close to total free energy of the fissioning system. The probability of such fission events for the fast neutron induced fission was found to be much higher than for spontaneous fission of 252Cf and thermal neutron induced fission of 235U. For experiments with 238U target the energy of incident neutrons were 5 MeV and 6.5 MeV. Close analysis of dependence of fission fragment distribution on compound nucleus excitation energy gave us some explanation of the phenomenon. It could be a process in highly excited compound nucleus which leads the fissioning system from the scission point into the fusion valley with high probability.

Effect of Fast Neutron to MA/PU Burning/Transmutation Characteristic Using a Fast Reactor

International Nuclear Information System (INIS)

Marsodi; Lasman, As Natio; Kimamoto, A.; Marsongkohadi; Zaki, S.

2003-01-01

MA/Pu burning/transmutation has been studied and evaluated using fast neutrons. Generally, neutron density at this fast burner reactor and transmutation has spectrum energy level around 0.2 MeV with wide enough variation, i.e. from low neutron spectrum to its peak is 0.2 MeV. This neutron spectrum energy level depends on the kind of cooler material or fuel used. Neutron spectrum higher than fast power reactor neutron spectrum is found by means of changing oxide fuel by metallic fuel and changing natrium cooler material by metallic or gas cooler material. This evaluation is conducted by various variations in accordance with the kind of fuel or cooler, MA/Pu fractions and fuel comparison fraction with respect to its cooler in order to get better neutron usage and MA/Pu burning speed. Reactor calculation evaluation in this paper was conducted with 26-group nuclear data cross section energy spectrum. The main purpose of the discussion is to know the effect of fast neutrons to burning/transmutation MA/Pu using fast neutrons

Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Niobium

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This test method describes procedures for measuring reaction rates by the activation reaction 93Nb(n,n′)93mNb. 1.2 This activation reaction is useful for monitoring neutrons with energies above approximately 0.5 MeV and for irradiation times up to about 30 years. 1.3 With suitable techniques, fast-neutron reaction rates for neutrons with energy distribution similar to fission neutrons can be determined in fast-neutron fluences above about 1016cm−2. In the presence of high thermal-neutron fluence rates (>1012cm−2·s−1), the transmutation of 93mNb due to neutron capture should be investigated. In the presence of high-energy neutron spectra such as are associated with fusion and spallation sources, the transmutation of 93mNb by reactions such as (n,2n) may occur and should be investigated. 1.4 Procedures for other fast-neutron monitors are referenced in Practice E 261. 1.5 Fast-neutron fluence rates can be determined from the reaction rates provided that the appropriate cross section information ...

The association of fast food consumption with poor dietary outcomes and obesity among children: is it the fast food or the remainder of the diet?123

Science.gov (United States)

Poti, Jennifer M; Duffey, Kiyah J

2014-01-01

Background: Although fast food consumption has been linked to adverse health outcomes, the relative contribution of fast food itself compared with the rest of the diet to these associations remains unclear. Objective: Our objective was to compare the independent associations with overweight/obesity or dietary outcomes for fast food consumption compared with dietary pattern for the remainder of intake. Design: This cross-sectional analysis studied 4466 US children aged 2–18 y from NHANES 2007–2010. Cluster analysis identified 2 dietary patterns for the non–fast food remainder of intake: Western (50.3%) and Prudent. Multivariable-adjusted linear and logistic regression models examined the association between fast food consumption and dietary pattern for the remainder of intake and estimated their independent associations with overweight/obesity and dietary outcomes. Results: Half of US children consumed fast food: 39.5% low-consumers (≤30% of energy from fast food) and 10.5% high-consumers (>30% of energy). Consuming a Western dietary pattern for the remainder of intake was more likely among fast food low-consumers (OR: 1.51; 95% CI: 1.24, 1.85) and high-consumers (OR: 2.21; 95% CI: 1.60, 3.05) than among nonconsumers. The remainder of diet was independently associated with overweight/obesity (β: 5.9; 95% CI: 1.3, 10.5), whereas fast food consumption was not, and the remainder of diet had stronger associations with poor total intake than did fast food consumption. Conclusions: Outside the fast food restaurant, fast food consumers ate Western diets, which might have stronger associations with overweight/obesity and poor dietary outcomes than fast food consumption itself. Our findings support the need for prospective studies and randomized trials to confirm these hypotheses. PMID:24153348

The Association between Socio-Demographic Charactristics and Fast Food Consumption withinHigh School Students in Isfahan, Iran

Directory of Open Access Journals (Sweden)

Parastoo Yarmohammadi

2015-12-01

Full Text Available Abstract Introduction: Fast food consumption has greatly increased with in adolescents in recent years, which is linked with weight gain, poor dietary indexes and insulin resistance. Hence, the purpose of this study was to examine the association between demographic characteristics and fast food consumption with in high school students. Materials & Methods: In this descriptive-analytic study, a sample of 521 high school students  aged 15-18 years were examined in Isfahan city, who were selected via multistage sampling method. The study data were collected using a questionnaire completed by the students. The present study probed to assess such items as frequency of fast food consumption, demographic characteristics, hours of television viewing, as well as high school students' knowledge and attitude. The collected data were analyzed using descriptive and inferential statistics. Result: Frequent intake of fast food (&ge1 time/week was reported 15.5% within females and 15.3% within males. A significant relationship was detected between parents’ high level of education and high income of the family with the fast food consumption. The predominate reasons for fast food consumption were stated as “enjoying tastes”, “eating at any place”,” inexpensive and economic”. Conclusion: The findings revealed that fast food consumption increased in families with high income and high education level, though these families needed to be educated on the harmful effects of fast food and how to choose the healthy foods. Therefore, some interventions may be regarded beneficial in order to reduce the exposure to the fast food and promote knowledge, attitude, and behavior change in regard with reducing consumption of fast food.

Opportunities for Integrated Fast Ignition program

International Nuclear Information System (INIS)

Mackinnon, A. J.; Key, M. H.; Hatchett, S. P.; Tabak, M.; Town, R.; Gregori, G.; Patel, P. K.; Snavely, R.; Freeman, R. R.; Stephens, R. B.; Beg, F.

2005-01-01

Experiments designed to investigate the physics of particle transport and heating of dense plasmas have been carried out in an number of facilities around the world since the publication of the fast ignition concept in 1997. To date a number of integrated experiments, examining the capsule implosion and subsequent heating have been carried out on the Gekko facility at the Institute of Laser Engineering (ILE) Osaka, Japan. The coupling of energy by the short pulse into the pre-compressed core in these experiments was very encouraging. More facilities capable of carrying out integrated experiments are currently under construction: Firex at ILEm the Omega EP facility at the University of Rochester, Z PW at Sandia National Lab, LIL in France and eventually high energy PW beams on the NIF. This presentation will review the current status of experiments in this area and discuss the capabilities of integrated fast ignition research that will be required to design the proof of principle and scaling experiments for fast ignition to be carried on the NIF. (Author)

Role of focused assessment with sonography for trauma as a screening tool for blunt abdominal trauma in young children after high energy trauma

NARCIS (Netherlands)

Tummers, W.; van Schuppen, J.; Langeveld, H.; Wilde, J.; Banderker, E.; van As, A.

2016-01-01

The objective of the study was to review the utility of focused assessement with sonography for trauma (FAST) as a screening tool for blunt abdominal trauma (BAT) in children involved in high energy trauma (HET), and to determine whether a FAST could replace computed tomography (CT) in clinical

Study of fast electron generation using multi beam of LFEX-class laser

International Nuclear Information System (INIS)

Hata, M; Nagatomo, H; Sakagami, H; Johzaki, T; Sentoku, Y

2016-01-01

Fast Ignition Realization Experiment project phase-I (FIREX-I) is being performed at Institute of Laser Engineering, Osaka University. In this project, the four-beam bundled high-energy Petawatt laser (LFEX) is being operated. LFEX laser provides great multi-beam irradiation flexibility, with the possibility of arrange the pulses in temporal sequence, spatially separate them in distinct spots of focus them in a single spot. In this paper, we study the two- beam interference effects on high-intensity picosecond laser-plasma interaction (LPI) by twodimensional relativistic Particle-In-Cell simulations. The interference causes surface perturbation, which enhances laser absorption and underdense plasma generation, increasing the accelerated electron number and their slope temperature. The laser-to-electron energy conversion efficiency for two-beam interference case is suitable for Fast Ignition (FI) compared to the single beam case, but the increment of fast electron divergence leads to lower energy coupling. To optimize the target design for FI, these interference effects should be taken into consideration. (paper)

Development of a fast rise-time, high-voltage pulse generator

International Nuclear Information System (INIS)

Zhang Yanxia; Zhu Jie; Li Xianyou

2006-01-01

In order to test the attenuation of the system, a fast rise-time, high-voltage pulse generator is required for the fast pulse signal measurement. The paper presents the development of the generator. More emphasis is paid on the discussion of the difficulties occurring in the circuit debugging and their resolutions. The output rise-time of the generator is 700 ps, the amplitude is adjustable in the range of 0 to 500 V, the pulse-width is adjustable in the range of 4ns to 1μs. (authors)

A Low-cost, High-yield Process for the Direct Productin of High Energy Density Liquid Fuel from Biomass

Energy Technology Data Exchange (ETDEWEB)

Agrawal, Rakesh [Purdue Univ., West Lafayette, IN (United States); Delgass, W. N. [Purdue Univ., West Lafayette, IN (United States); Ribeiro, F. [Purdue Univ., West Lafayette, IN (United States)

2013-08-31

The primary objective and outcome of this project was the development and validation of a novel, low-cost, high-pressure fast-hydropyrolysis/hydrodeoxygenation (HDO) process (H₂Bioil) using supplementary hydrogen (H₂) to produce liquid hydrocarbons from biomass. The research efforts under the various tasks of the project have culminated in the first experimental demonstration of the H₂Bioil process, producing 100% deoxygenated >C4+ hydrocarbons containing 36-40% of the carbon in the feed of pyrolysis products from biomass. The demonstrated H{sub 2}Bioil process technology (i.e. reactor, catalyst, and downstream product recovery) is scalable to a commercial level and is estimated to be economically competitive for the cases when supplementary H₂ is sourced from coal, natural gas, or nuclear. Additionally, energy systems modeling has revealed several process integration options based on the H₂Bioilprocess for energy and carbon efficient liquid fuel production. All project tasks and milestones were completed or exceeded. Novel, commercially-scalable, high-pressure reactors for both fast-hydropyrolysis and hydrodeoxygenation were constructed, completing Task A. These reactors were capable of operation under a wide-range of conditions; enabling process studies that lead to identification of optimum process conditions. Model compounds representing biomass pyrolysis products were studied, completing Task B. These studies were critical in identifying and developing HDO catalysts to target specific oxygen functional groups. These process and model compound catalyst studies enabled identification of catalysts that achieved 100% deoxygenation of the real biomass feedstock, sorghum, to form hydrocarbons in high yields as part of Task C. The work completed during this grant has identified and validated the novel and commercially scalable H₂Bioil process for production of hydrocarbon fuels from biomass. Studies on

Unbiased free energy estimates in fast nonequilibrium transformations using Gaussian mixtures

International Nuclear Information System (INIS)

Procacci, Piero

2015-01-01

In this paper, we present an improved method for obtaining unbiased estimates of the free energy difference between two thermodynamic states using the work distribution measured in nonequilibrium driven experiments connecting these states. The method is based on the assumption that any observed work distribution is given by a mixture of Gaussian distributions, whose normal components are identical in either direction of the nonequilibrium process, with weights regulated by the Crooks theorem. Using the prototypical example for the driven unfolding/folding of deca-alanine, we show that the predicted behavior of the forward and reverse work distributions, assuming a combination of only two Gaussian components with Crooks derived weights, explains surprisingly well the striking asymmetry in the observed distributions at fast pulling speeds. The proposed methodology opens the way for a perfectly parallel implementation of Jarzynski-based free energy calculations in complex systems

The Ringo2 Optical Polarisation Catalogue of 13 High-Energy Blazars

Science.gov (United States)

Barres de Almeida, Ulisses; Jermak, Helen; Mundell, Carole; Lindfors, Elina; Nilsson, Kari; Steele, Iain

2015-08-01

We present the findings of the Ringo2 3-year survey of 13 blazars (3 FSRQs and 10 BL Lacs) with regular coverage and reasonably fast cadence of one to three observations a week. Ringo2 was installed on the Liverpool Robotic Telescope (LT) on the Canary Island of La Palma between 2009 and 2012 and monitored thirteen high-energy-emitting blazars in the northern sky. The objects selected as well as the observational strategy were tuned to maximise the synergies with high-energy X- to gamma-ray observations. Therefore this sample stands out as a well-sampled, long-term view of high-energy AGN jets in polarised optical light. Over half of the sources exhibited an increase in optical flux during this period and almost a quarter were observed in outburst. We compare the optical data to gamma (Fermi/LAT) and X-ray data during these periods of outburst. In this talk we present the data obtained for all sources over the lifetime of Ringo2 with additional optical data from the KVA telescope and the SkyCamZ wide-field camera (on the LT), we explore the relationship between the change in polarisation angle as a function of time (dEVPA/dMJD), flux and polarisation degree along with cross correlation comparisons of optical and high-energy flux.

Solid ionic: these unusual materials applications in high-energy-density

International Nuclear Information System (INIS)

Shriver, D.F.; Farrington, G.C.

1985-01-01

The idea that ions can diffuse as rapidly in a solid as in an aqueous salt solution may seem strange to many chemists. But a variety of solids with high ionic conductivities are known. Compounds have been discovered that conduct anions (including F - and O 2- ) and cations (including monovalent, divalent, and trivalent cations). These substances range from hard, refractory materials, such as sodium β-alumina, through softer compounds, such as silver iodide (AgI) to the very soft polymer electrolytes. They include compounds that are stoichiometric (AgI), nonstoichiometric (sodium β-alumina), or doped (calcia-stabilized zirconia). A variety of names have been applied to these materials: among them, solid electrolytes, superionic conductors, and fast-ion conductors. Fast-ion transport in solids is a lively area of study in solid-state chemistry and physics. High-conductivity solid electrolytes have revolutionized conventional concepts of ionic compounds, and their potential uses range from high-energy-density battery and fuel-cell electrolytes to chemical sensors and from lasers to phosphors. Devices using solid electrolytes are already available commercially-oxygen detectors for automotive pollution-control systems employ solid O 2- electrolytes, and solid-state batteries using solid electrolytes are employed in heart pacemakers

An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

Energy Technology Data Exchange (ETDEWEB)

Shannon M. Bragg-Sitton; Richard D. Boardman; Robert S. Cherry; Wesley R. Deason; Michael G. McKellar

2014-03-01

Integration of an advanced, sodium-cooled fast spectrum reactor into nuclear hybrid energy system (NHES) architectures is the focus of the present study. A techno-economic evaluation of several conceptual system designs was performed for the integration of a sodium-cooled Advanced Fast Reactor (AFR) with the electric grid in conjunction with wind-generated electricity. Cases in which excess thermal and electrical energy would be reapportioned within an integrated energy system to a chemical plant are presented. The process applications evaluated include hydrogen production via high temperature steam electrolysis and methanol production via steam methane reforming to produce carbon monoxide and hydrogen which feed a methanol synthesis reactor. Three power cycles were considered for integration with the AFR, including subcritical and supercritical Rankine cycles and a modified supercritical carbon dioxide modified Brayton cycle. The thermal efficiencies of all of the modeled power conversions units were greater than 40%. A thermal efficiency of 42% was adopted in economic studies because two of the cycles either performed at that level or could potentially do so (subcritical Rankine and S-CO2 Brayton). Each of the evaluated hybrid architectures would be technically feasible but would demonstrate a different internal rate of return (IRR) as a function of multiple parameters; all evaluated configurations showed a positive IRR. As expected, integration of an AFR with a chemical plant increases the IRR when “must-take” wind-generated electricity is added to the energy system. Additional dynamic system analyses are recommended to draw detailed conclusions on the feasibility and economic benefits associated with AFR-hybrid energy system operation.

Nonlinear dielectric thin films for high-power electric storage with energy density comparable with electrochemical supercapacitors.

Science.gov (United States)

Yao, Kui; Chen, Shuting; Rahimabady, Mojtaba; Mirshekarloo, Meysam Sharifzadeh; Yu, Shuhui; Tay, Francis Eng Hock; Sritharan, Thirumany; Lu, Li

2011-09-01

Although batteries possess high energy storage density, their output power is limited by the slow movement of charge carriers, and thus capacitors are often required to deliver high power output. Dielectric capacitors have high power density with fast discharge rate, but their energy density is typically much lower than electrochemical supercapacitors. Increasing the energy density of dielectric materials is highly desired to extend their applications in many emerging power system applications. In this paper, we review the mechanisms and major characteristics of electric energy storage with electrochemical supercapacitors and dielectric capacitors. Three types of in-house-produced ferroic nonlinear dielectric thin film materials with high energy density are described, including (Pb(0.97)La(0.02))(Zr(0.90)Sn(0.05)Ti(0.05))O(3) (PLZST) antiferroelectric ceramic thin films, Pb(Zn(1/3)Nb(2/3))O(3-)Pb(Mg(1/3)Nb(2/3))O(3-)PbTiO(3) (PZN-PMN-PT) relaxor ferroelectric ceramic thin films, and poly(vinylidene fluoride) (PVDF)-based polymer blend thin films. The results showed that these thin film materials are promising for electric storage with outstandingly high power density and fairly high energy density, comparable with electrochemical supercapacitors.

“Exploring High Energy Interactions with CMS at the LHC”

Energy Technology Data Exchange (ETDEWEB)

Sulak, Lawrence R. [; Boston Univ., MA (United States)

2016-08-01

This High Energy Physics research project achieved its goal of exploring high-energy interactions with 7, 8 and 13 TeV data accumulated by CMS at the Energy Frontier. For the original hadron calorimeter (HCAL) and for its upgrade during Long Shutdown 1 (LS1), the PI helped propose and implement the upgrading the phototubes, new electronics, and fast timing of the hadronic forward (HF) and hadronic outer (HO) calorimeters of CMS, projects which he had forcefully advocated since the inception of CMS. The PI and his colleagues Prof. J. Rohlf and chief electronics engineer E. Hazen, his post-docs A. Heister and S. Girgis, and his graduate students (P. Lawson and D. Arcaro) contributed software tools used in perfecting of μTCA and Advanced Mezzanine Card (AMC13) electronics, the PC board that provides clock, timing and DAQ service for HCAL (and now many other subdetectors and central systems in the upgraded CMS detector). This Task reaped the benefits of these hardware contributions 1) to hermiticity for missing energy searches, and 2) to forward tagging jets for Vector Boson Fusion processes by analyzing and publishing early data, including that for the Higgs discovery and for exotic and supersymmetric searches.

Dynamically controlled energy dissipation for fast magnetic vortex switching

Science.gov (United States)

Badea, R.; Berezovsky, J.

2017-09-01

Manipulation of vortex states in magnetic media provides new routes towards information storage and processing technology. The typical slow relaxation times (˜100 ns) of magnetic vortex dynamics may present an obstacle to the realization of these applications. Here, we investigate how a vortex state in a ferromagnetic microdisk can be manipulated in a way that translates the vortex core while enhancing energy dissipation to rapidly damp the vortex dynamics. We use time-resolved differential magneto-optical Kerr effect microscopy to measure the motion of the vortex core in response to applied magnetic fields. We first map out how the vortex core becomes sequentially trapped by pinning sites as it translates across the disk. After applying a fast magnetic field step to translate the vortex from one pinning site to another, we observe long-lived dynamics of the vortex as it settles to the new equilibrium. We then demonstrate how the addition of a short (<10 ns) magnetic field pulse can induce additional energy dissipation, strongly damping the long-lived dynamics. A model of the vortex dynamics using the Thiele equation of motion explains the mechanism behind this effect.

Energy Cascade Rate in Compressible Fast and Slow Solar Wind Turbulence

Energy Technology Data Exchange (ETDEWEB)

Hadid, L. Z.; Sahraoui, F.; Galtier, S., E-mail: lina.hadid@lpp.polytechnique.fr [LPP, CNRS, Ecole Polytechnique, UPMC Univ Paris 06, Univ. Paris-Sud, Observatoire de Paris, Université Paris-Saclay, Sorbonne Universités, PSL Research University, F-91128 Palaiseau (France)

2017-03-20

Estimation of the energy cascade rate in the inertial range of solar wind turbulence has been done so far mostly within incompressible magnetohydrodynamics (MHD) theory. Here, we go beyond that approximation to include plasma compressibility using a reduced form of a recently derived exact law for compressible, isothermal MHD turbulence. Using in situ data from the THEMIS / ARTEMIS spacecraft in the fast and slow solar wind, we investigate in detail the role of the compressible fluctuations in modifying the energy cascade rate with respect to the prediction of the incompressible MHD model. In particular, we found that the energy cascade rate (1) is amplified particularly in the slow solar wind; (2) exhibits weaker fluctuations in spatial scales, which leads to a broader inertial range than the previous reported ones; (3) has a power-law scaling with the turbulent Mach number; (4) has a lower level of spatial anisotropy. Other features of solar wind turbulence are discussed along with their comparison with previous studies that used incompressible or heuristic (nonexact) compressible MHD models.

Energy Cascade Rate in Compressible Fast and Slow Solar Wind Turbulence

International Nuclear Information System (INIS)

Hadid, L. Z.; Sahraoui, F.; Galtier, S.

2017-01-01

Estimation of the energy cascade rate in the inertial range of solar wind turbulence has been done so far mostly within incompressible magnetohydrodynamics (MHD) theory. Here, we go beyond that approximation to include plasma compressibility using a reduced form of a recently derived exact law for compressible, isothermal MHD turbulence. Using in situ data from the THEMIS / ARTEMIS spacecraft in the fast and slow solar wind, we investigate in detail the role of the compressible fluctuations in modifying the energy cascade rate with respect to the prediction of the incompressible MHD model. In particular, we found that the energy cascade rate (1) is amplified particularly in the slow solar wind; (2) exhibits weaker fluctuations in spatial scales, which leads to a broader inertial range than the previous reported ones; (3) has a power-law scaling with the turbulent Mach number; (4) has a lower level of spatial anisotropy. Other features of solar wind turbulence are discussed along with their comparison with previous studies that used incompressible or heuristic (nonexact) compressible MHD models.

Konsumsi fast food dan soft drink sebagai faktor risiko obesitas pada remaja

Directory of Open Access Journals (Sweden)

Ayu Rafiony

2015-04-01

Full Text Available Background: Recently, obesity has become health problem which was frequently associated with an increased occurrence of non-communicable diseases. The prevalence of obesity has been increasing in both developed and developing countries. The increasing prevalence of obesity was marked by a shift in eating pattern composition containing high fat, cholesterol, but low in fiber such as consumption of fast food and soft drinks. The imbalance of nutrient intake was one of the risk factors for the emergence of obesity in adolescents. Obesity in adolescents at risk of becoming obese in adulthood and potentially can lead to cardiovascular and metabolic diseases Objective: This study aimed to find out the prevalence of obesity and to investigate risk factors for energy intake and frequency of consumption of fast food and soft drinks on the incidence of obesity in high school students in Pontianak. Method: This research was an observational study which involves case-control design. The samples in this study are 160 students consisting of 80 obese high school teenagers and 80 non-obese high school teenagers. The choice for a subject of research used proportional stratified random sampling. Measurement of obesity status subject was taken by the measurement of weight and height based on the reference standard WHO / NCHS. It also involves data intake of fast food and soft drinks based on interviews with SQFFQ. Data were analyzed by chi-square test, t-test, and logistic regression. Results: The prevalence of obesity in high school teenagers in Pontianak was 9.29%. The bivariate test result showed no association  between total  energy intake of fast food and obesity (p0.05. There was a relationship between the frequency of total  fast food and of the local fast food consumption with obesity (p0.05. Multivariable analysis showed that the total energy intake was the most dominant factor to the onset of obesity (p<0.05; OR=5.27; 95% CI: 1.64-16.97. Conclusion

Technology update on fast plastic scintillators for medical applications

International Nuclear Information System (INIS)

Lyons, P.B.

1977-01-01

Plastic scintillators appear to have potential utility in three research areas related to nuclear medicine: (1) high count rate applications in general, (2) positron camera applications, and (3) positron source localization through measurement of relative arrival times of annihilation quanta at two co-linear detectors. These three areas of applicability depend on improvement in three specific areas of plastic scintillator technology: (a) development of plastics with very fast decay times, (b) development of plastics with greatly improved high energy photon detection efficiencies (high-Z loaded plastics), and (c) improvement of fast timing system capabilities. The three preceding areas of improvement are discussed

Suppression of chaos at slow variables by rapidly mixing fast dynamics through linear energy-preserving coupling

Science.gov (United States)

Abramov, R. V.

2011-12-01

Chaotic multiscale dynamical systems are common in many areas of science, one of the examples being the interaction of the low-frequency dynamics in the atmosphere with the fast turbulent weather dynamics. One of the key questions about chaotic multiscale systems is how the fast dynamics affects chaos at the slow variables, and, therefore, impacts uncertainty and predictability of the slow dynamics. Here we demonstrate that the linear slow-fast coupling with the total energy conservation property promotes the suppression of chaos at the slow variables through the rapid mixing at the fast variables, both theoretically and through numerical simulations. A suitable mathematical framework is developed, connecting the slow dynamics on the tangent subspaces to the infinite-time linear response of the mean state to a constant external forcing at the fast variables. Additionally, it is shown that the uncoupled dynamics for the slow variables may remain chaotic while the complete multiscale system loses chaos and becomes completely predictable at the slow variables through increasing chaos and turbulence at the fast variables. This result contradicts the common sense intuition, where, naturally, one would think that coupling a slow weakly chaotic system with another much faster and much stronger chaotic system would result in general increase of chaos at the slow variables.

Why high energy physics

International Nuclear Information System (INIS)

Diddens, A.N.; Van de Walle, R.T.

1981-01-01

An argument is presented for high energy physics from the point of view of the practitioners. Three different angles are presented: The cultural consequence and scientific significance of practising high energy physics, the potential application of the results and the discovery of high energy physics, and the technical spin-offs from the techniques and methods used in high energy physics. (C.F.)

Generation of sheet currents by high frequency fast MHD waves

Energy Technology Data Exchange (ETDEWEB)

Núñez, Manuel, E-mail: mnjmhd@am.uva.es

2016-07-01

The evolution of fast magnetosonic waves of high frequency propagating into an axisymmetric equilibrium plasma is studied. By using the methods of weakly nonlinear geometrical optics, it is shown that the perturbation travels in the equatorial plane while satisfying a transport equation which enables us to predict the time and location of formation of shock waves. For plasmas of large magnetic Prandtl number, this would result into the creation of sheet currents which may give rise to magnetic reconnection and destruction of the original equilibrium. - Highlights: • Regular solutions of quasilinear hyperbolic systems may evolve into shocks. • The shock location is found for high frequency fast MHD waves. • The result is applied to static axisymmetric equilibria. • The previous process may lead to the formation of sheet currents and destruction of the equilibrium.

A Control Algorithm for Electric Vehicle Fast Charging Stations Equipped with Flywheel Energy Storage Systems

DEFF Research Database (Denmark)

Sun, Bo; Dragicevic, Tomislav; Freijedo Fernandez, Francisco Daniel

2016-01-01

This paper proposes a control strategy for plugin electric vehicle (PEV) fast charging station (FCS) equipped with a flywheel energy storage system (FESS). The main role of the FESS is not to compromise the predefined charging profile of PEV battery during the provision of a hysteresis-type active...

The acceleration of particles to high energy

International Nuclear Information System (INIS)

Parker, E.N.

1976-01-01

The common occurrence, and often spectacular consequence, of fast particles in active astrophysical bodies has attracted the attention of physicists for more than four decades. The acceleration mechanisms, whatever they may be, are remarkably efficient, converting a major fraction of the total energy into fast particles. A variety of ideas have arisen, suggesting how and why fast particles are generated in various circumstances. The principal limitation on particle acceleration theories has been the realization that the universe in not filled with a hard vacuum, but rather is pervaded everywhere by tenuous ionized gases quite able to short circuit any large-scale electric fields that occur under ordinary circumstances. A number of the early ideas on the acceleration of cosmic rays have been discarded for this reason. The basic theoretical ideas can be grouped roughly into five parts: 1. hydromagnetic fields; 2. field in reduced conductivity; 3. plasma turbulence; 4. low frequency electromagnetic waves; 5. supernova explosion. Each of these is considered in turn. (Auth.)

FAMP: An example of multiprocessing in high energy physics

International Nuclear Information System (INIS)

Hertzberger, L.O.

1983-04-01

Possible applications of multi microprocessor systems in the different areas of experimental High Energy Physics are considered. It is shown that these systems, of which the Fast Amsterdam Multi Processor (FAMP) system is an example, are potentially very powerful in on-line and in off-line applications. It is discussed how the potential advantages have been exploited in the FAMP system by a careful choice of hardware and software. An overview is given of the use of the FAMP system for second-stage triggering, on-line event filtering and monitoring purposes in the NA11, UA1 and JADE experiments and of other possible applications. (Auth.)

Flexible Aqueous Li-Ion Battery with High Energy and Power Densities.

Science.gov (United States)

Yang, Chongyin; Ji, Xiao; Fan, Xiulin; Gao, Tao; Suo, Liumin; Wang, Fei; Sun, Wei; Chen, Ji; Chen, Long; Han, Fudong; Miao, Ling; Xu, Kang; Gerasopoulos, Konstantinos; Wang, Chunsheng

2017-11-01

A flexible and wearable aqueous symmetrical lithium-ion battery is developed using a single LiVPO 4 F material as both cathode and anode in a "water-in-salt" gel polymer electrolyte. The symmetric lithium-ion chemistry exhibits high energy and power density and long cycle life, due to the formation of a robust solid electrolyte interphase consisting of Li 2 CO 3 -LiF, which enables fast Li-ion transport. Energy densities of 141 Wh kg -1 , power densities of 20 600 W kg -1 , and output voltage of 2.4 V can be delivered during >4000 cycles, which is far superior to reported aqueous energy storage devices at the same power level. Moreover, the full cell shows unprecedented tolerance to mechanical stress such as bending and cutting, where it not only does not catastrophically fail, as most nonaqueous cells would, but also maintains cell performance and continues to operate in ambient environment, a unique feature apparently derived from the high stability of the "water-in-salt" gel polymer electrolyte. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Fast Tracker Real Time Processor: high quality real-time tracking at ATLAS

CERN Document Server

Stabile, A; The ATLAS collaboration

2011-01-01

As the LHC luminosity is ramped up to the design level of 1x1034 cm−2 s−1 and beyond, the high rates, multiplicities, and energies of particles seen by the detectors will pose a unique challenge. Only a tiny fraction of the produced collisions can be stored on tape and immense real-time data reduction is needed. An effective trigger system must maintain high trigger efficiencies for the most important physics and at the same time suppress the enormous QCD backgrounds. This requires massive computing power to minimize the online execution time of complex algorithms. A multi-level trigger is an effective solution for an otherwise impossible problem. The Fast Tracker (FTK)[1], [2] is a proposed upgrade to the current ATLAS trigger system that will operate at full Level-1 output rates and provide high quality tracks reconstructed over the entire detector by the start of processing in Level-2. FTK is a dedicated Super Computer based on a mixture of advanced technologies. The architecture broadly employs powerf...

mrsFAST-Ultra: a compact, SNP-aware mapper for high performance sequencing applications.

Science.gov (United States)

Hach, Faraz; Sarrafi, Iman; Hormozdiari, Farhad; Alkan, Can; Eichler, Evan E; Sahinalp, S Cenk

2014-07-01

High throughput sequencing (HTS) platforms generate unprecedented amounts of data that introduce challenges for processing and downstream analysis. While tools that report the 'best' mapping location of each read provide a fast way to process HTS data, they are not suitable for many types of downstream analysis such as structural variation detection, where it is important to report multiple mapping loci for each read. For this purpose we introduce mrsFAST-Ultra, a fast, cache oblivious, SNP-aware aligner that can handle the multi-mapping of HTS reads very efficiently. mrsFAST-Ultra improves mrsFAST, our first cache oblivious read aligner capable of handling multi-mapping reads, through new and compact index structures that reduce not only the overall memory usage but also the number of CPU operations per alignment. In fact the size of the index generated by mrsFAST-Ultra is 10 times smaller than that of mrsFAST. As importantly, mrsFAST-Ultra introduces new features such as being able to (i) obtain the best mapping loci for each read, and (ii) return all reads that have at most n mapping loci (within an error threshold), together with these loci, for any user specified n. Furthermore, mrsFAST-Ultra is SNP-aware, i.e. it can map reads to reference genome while discounting the mismatches that occur at common SNP locations provided by db-SNP; this significantly increases the number of reads that can be mapped to the reference genome. Notice that all of the above features are implemented within the index structure and are not simple post-processing steps and thus are performed highly efficiently. Finally, mrsFAST-Ultra utilizes multiple available cores and processors and can be tuned for various memory settings. Our results show that mrsFAST-Ultra is roughly five times faster than its predecessor mrsFAST. In comparison to newly enhanced popular tools such as Bowtie2, it is more sensitive (it can report 10 times or more mappings per read) and much faster (six times or

A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage

KAUST Repository

Pasta, Mauro; Wessells, Colin D.; Huggins, Robert A.; Cui, Yi

2012-01-01

New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles. © 2012 Macmillan Publishers Limited. All rights reserved.

A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage

KAUST Repository

Pasta, Mauro

2012-10-23

New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles. © 2012 Macmillan Publishers Limited. All rights reserved.

Reflections on the introduction of fast breeder reactors in the DeBeNeLux states

International Nuclear Information System (INIS)

Schroeder, R.; Wagner, J.

1975-06-01

This report gives a survey of the impact of introducing sodium-cooled fast breeder reactors in the Federal Republic of Germany and the BeNeLux countries (DeBeNeLux region). The supply situation with respect to electric and thermal energy is studied in particular, together with aspects of economy and environmental impact. The potential and consequences of a breeder economy, the present status and future r+d work are discussed. In addition to sodium-cooled fast breeder reactors with oxide or carbide fuel, alternative solutions are touched: 1) light water and high temperature reactors, 2) helium-cooled fast breeder reactors, 3) geothermal energy, solar energy and fusion energy. (orig.) [de

Yolk-shell structured Sb@C anodes for high energy Na-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Song, Junhua; Yan, Pengfei; Luo, Langli; Qi, Xingguo; Rong, Xiaohui; Zheng, Jianming; Xiao, Biwei; Feng, Shuo; Wang, Chongmin; Hu, Yong-Sheng; Lin, Yuehe; Sprenkle, Vincent L.; Li, Xiaolin

2017-10-01

Despite great advances in sodium-ion battery developments, the search for high energy and stable anode materials remains a challenge. Alloy or conversion-typed anode materials are attractive candidates of high specific capacity and low voltage potential, yet their applications are hampered by the large volume expansion and hence poor electrochemical reversibility and fast capacity fade. Here, we use antimony (Sb) as an example to demonstrate the use of yolk-shell structured anodes for high energy Na-ion batteries. The Sb@C yolk-shell structure prepared by controlled reduction and selective removal of Sb2O3 from carbon coated Sb2O3 nanoparticles can accommodate the Sb swelling upon sodiation and improve the structural/electrical integrity against pulverization. It delivers a high specific capacity of ~554 mAh•g-1, good rate capability (315 mhA•g-1 at 10C rate) and long cyclability (92% capacity retention over 200 cycles). Full-cells of O3-Na0.9[Cu0.22Fe0.30Mn0.48]O2 cathodes and Sb@C-hard carbon composite anodes demonstrate a high specific energy of ~130 Wh•kg-1 (based on the total mass of cathode and anode) in the voltage range of 2.0-4.0 V, ~1.5 times energy of full-cells with similar design using hard carbon anodes.

High Energy Density Physics and Exotic Acceleration Schemes

International Nuclear Information System (INIS)

Cowan, T.; Colby, E.

2005-01-01

The High Energy Density and Exotic Acceleration working group took as our goal to reach beyond the community of plasma accelerator research with its applications to high energy physics, to promote exchange with other disciplines which are challenged by related and demanding beam physics issues. The scope of the group was to cover particle acceleration and beam transport that, unlike other groups at AAC, are not mediated by plasmas or by electromagnetic structures. At this Workshop, we saw an impressive advancement from years past in the area of Vacuum Acceleration, for example with the LEAP experiment at Stanford. And we saw an influx of exciting new beam physics topics involving particle propagation inside of solid-density plasmas or at extremely high charge density, particularly in the areas of laser acceleration of ions, and extreme beams for fusion energy research, including Heavy-ion Inertial Fusion beam physics. One example of the importance and extreme nature of beam physics in HED research is the requirement in the Fast Ignitor scheme of inertial fusion to heat a compressed DT fusion pellet to keV temperatures by injection of laser-driven electron or ion beams of giga-Amp current. Even in modest experiments presently being performed on the laser-acceleration of ions from solids, mega-amp currents of MeV electrons must be transported through solid foils, requiring almost complete return current neutralization, and giving rise to a wide variety of beam-plasma instabilities. As keynote talks our group promoted Ion Acceleration (plenary talk by A. MacKinnon), which historically has grown out of inertial fusion research, and HIF Accelerator Research (invited talk by A. Friedman), which will require impressive advancements in space-charge-limited ion beam physics and in understanding the generation and transport of neutralized ion beams. A unifying aspect of High Energy Density applications was the physics of particle beams inside of solids, which is proving to

Development and Characterization of a High Sensitivity Segmented Fast Neutron Spectrometer (FaNS-2).

Science.gov (United States)

Langford, T J; Beise, E J; Breuer, H; Heimbach, C R; Ji, G; Nico, J S

2016-01-01

We present the development of a segmented fast neutron spectrometer (FaNS-2) based upon plastic scintillator and 3 He proportional counters. It was designed to measure both the flux and spectrum of fast neutrons in the energy range of few MeV to 1 GeV. FaNS-2 utilizes capture-gated spectroscopy to identify neutron events and reject backgrounds. Neutrons deposit energy in the plastic scintillator before capturing on a 3 He nucleus in the proportional counters. Segmentation improves neutron energy reconstruction while the large volume of scintillator increases sensitivity to low neutron fluxes. A main goal of its design is to study comparatively low neutron fluxes, such as cosmogenic neutrons at the Earth's surface, in an underground environment, or from low-activity neutron sources. In this paper, we present details of its design and construction as well as its characterization with a calibrated 252 Cf source and monoenergetic neutron fields of 2.5 MeV and 14 MeV. Detected monoenergetic neutron spectra are unfolded using a Singular Value Decomposition method, demonstrating a 5% energy resolution at 14 MeV. Finally, we discuss plans for measuring the surface and underground cosmogenic neutron spectra with FaNS-2.

Performance evaluation of novel LaBr3(Ce) scintillator geometries for fast-timing applications

International Nuclear Information System (INIS)

Vedia, V.; Carmona-Gallardo, M.; Fraile, L.M.; Mach, H.; Udías, J.M.

2017-01-01

We evaluate the performance of two LaBr 3 (Ce) crystals that were produced with special geometries, aimed at enhancing the scintillation light collection and thus the time resolution. Their design was motivated by the construction of high-performance fast-timing arrays like the FAst TIMing array for DESPEC (FATIMA), which demands a high packing factor in addition to good time and energy resolutions. Energy resolution and efficiency were measured using standard calibration sources. Timing measurements were performed at 60 Co and 22 Na γ-energies against a fast BaF 2 reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the constant fraction discriminator parameters. Monte Carlo simulations using the Geant4 toolkit were performed in order to achieve a better understanding of how the new geometries affect the light transport and thus the performance of the crystals. It is found that the conical-shaped LaBr 3 (Ce) crystals are optimal for fast-timing applications and for the construction of arrays such as FATIMA.

Impact of Fast Charging on Life of EV Batteries; NREL (National Renewable Energy Laboratory)

Energy Technology Data Exchange (ETDEWEB)

Neubauer, Jeremy; Wood, Eric; Burton, Evan; Smith, Kandler; Pesaran, Ahmad

2015-05-03

Installation of fast charging infrastructure is considered by many as one of potential solutions to increase the utility and range of electric vehicles (EVs). This is expected to reduce the range anxiety of drivers of EVs and thus increase their market penetration. Level 1 and 2 charging in homes and workplaces is expected to contribute to the majority of miles driven by EVs. However, a small percentage of urban driving and most of inter-city driving could be only achieved by a fast-charging network. DC fast charging at 50 kW, 100 kW, 120 kW compared to level 1 (3.3 kW) and level 2 (6.6 kW) results in high-current charging that can adversely impact the life of the battery. In the last couple of years, we have investigated the impact of higher current rates in batteries and potential of higher temperatures and thus lower service life. Using mathematical models, we investigated the temperature increase of batteries due to higher heat generation during fast charge and have found that this could lead to higher temperatures. We compared our models with data from other national laboratories both for fine-tuning and calibration. We found that the incremental temperature rise of batteries during 1C to 3C fast charging may reduce the practical life of the batteries by less than 10% over 10 to 15 years of vehicle ownership. We also found that thermal management of batteries is needed for fast charging to prevent high temperature excursions leading to unsafe conditions.

High-pressure 3He-Xe gas scintillators for simultaneous detection of neutrons and gamma rays over a large energy range

International Nuclear Information System (INIS)

Tornow, W.; Esterline, J.H.; Leckey, C.A.; Weisel, G.J.

2011-01-01

We report on features of high-pressure 3 He-Xe gas scintillators which have not been sufficiently addressed in the past. Such gas scintillators can be used not only for the efficient detection of low-energy neutrons but at the same time for the detection and identification of γ-rays as well. Furthermore, 3 He-Xe gas scintillators are also very convenient detectors for fast neutrons in the 1-10 MeV energy range and for high-energy γ-rays in the 7-15 MeV energy range. Due to their linear pulse-height response and self calibration via the 3 He(n,p) 3 H reaction, neutron and γ-ray energies can easily be determined in this high-energy regime.

An energy and direction independent fast neutron dosemeter based on electrochemically etched CR-39 nuclear track detectors

International Nuclear Information System (INIS)

James, K.; Matiullah; Durrani, S.A.

1987-01-01

A computer-based model is presented, which simulates the dose equivalent response of electrochemically etched CR-39 to fast neutrons of various energies and angles of incidence. Most previous calculations of the response of CR-39 have neglected the production of recoiling oxygen and carbon nuclei as well as α particles in the CR-39. We calculate that these 'heavy recoils' and α particles are the major source of electrochemically etchable tracks in bare CR-39 at neutron energies above approx. 2 MeV under typical etching conditions. Our calculations have been extended to predict the response of CR-39 used in conjunction with various combinations of polymeric front radiators and we have determined the radiator stack configuration with produces the most energy independent response. Again, the heavy recoils and α particles cannot be neglected and, for energies above approx. 2 MeV, these produce typically about 20% of the total response of our optimum stack. This type of fast neutron dosemeter is, however, strongly direction dependent. We have integrated the response over all appropriate angles to predict the dose equivalent response for two representative neutron fields, and we suggest a method for minimising the angular dependence. (author)

Fast liberation of energy stored using superconductors; Liberation rapide d'energie stockee au moyen de supraconducteurs

Energy Technology Data Exchange (ETDEWEB)

Prost, G; Sole, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

After a rapid description of the circumstances in which they first thought of using superconducting materials for the storage and liberation of energy, the authors examine, in comparison to condensers, the energy densities which can thus be stored, the methods used for introducing this energy into the superconducting circuit and for trapping it, and the law governing the discharge of this energy into a purely dissipative impedance. This leads to a derivation of the expression for the energy yield which depends on the characteristics of the switch used for opening the superconducting circuit. An experimental study has been made of a superconducting switch with a view to understanding the various parameters. As a result of this analysis, transitions of this switch, over the whole of its mass, were obtained for periods of a few microseconds, and energy yields close to unity were obtained. The obtention of fast discharges is now no longer a technological problem. (authors) [French] Rappelant tres brievement les circonstances dans lesquelles ont pris naissance leurs premieres idees d'utilisation des materiaux supraconducteurs pour le stockage et la liberation d'energie les auteurs examinent, par rapport aux condensateurs, les densites d'energie que l'on peut ainsi stocker, les methodes utilisables pour introduire cette energie dans le circuit supraconducteur et pour la pieger, la loi de decharge de cette energie dans une impedance purement dissipative. Ceci conduit a l'expression du rendement en energie. Ce rendement depend des caracteristiques de l'interrupteur qui sert a ouvrir le circuit supraconducteur. Le cas de l'interrupteur supraconducteur a ete analyse experimentalement de facon a en degager les differents parametres. La suite de cette analyse, des transitions de l'interrupteur, dans la totalite de sa masse, ont ete obtenues dans des temps de quelques microsecondes permettant des rendements en energie se rapprochant de l'unite. L'obtention de decharges rapides

A fast chopper for the Fermilab High Intensity Neutrino Source (HINS)

Energy Technology Data Exchange (ETDEWEB)

Madrak, R.; Wildman, D.; /Fermilab; Dymokde-Bradshaw, A.; Hares, J.; Kellett, P.

2008-10-01

A fast chopper capable of kicking single 2.5 MeV H-bunches spaced at 325 MHz, at rates greater than 50 MHz is needed for the Fermilab High Intensity Neutrino Source (HINS) [1]. Four 1.2 kV fast pulsers, designed and manufactured by Kentech Instruments Ltd., will drive a 0.5 m long meander made from a copper plated ceramic composite. Test results showing pulses from the first 1.2 kV pulser and meander results will be presented.

Linear programming optimization of nuclear energy strategy with sodium-cooled fast reactors

International Nuclear Information System (INIS)

Lee, Je Whan; Jeong, Yong Hoon; Chang, Yoon Il; Chang, Soon Heung

2011-01-01

Nuclear power has become an essential part of electricity generation to meet the continuous growth of electricity demand. A Sodium-cooled Fast Reactor (SFR) was developed to extend uranium resource utilization under a growing nuclear energy scenario while concomitantly providing a nuclear waste management solution. Key questions in this scenario are when to introduce SFRs and how many reactors should be introduced. In this study, a methodology using Linear Programming is employed in order to quantify an optimized growth pattern of a nuclear energy system comprising light water reactors and SFRs. The optimization involves tradeoffs between SFR capital cost premiums and the total system U3O8 price premiums. Optimum nuclear growth patterns for several scenarios are presented, as well as sensitivity analyses of important input parameters

Sodium fast reactors energy conversion systems. Na-CO2 interaction. Comparison with Na-water interaction of conventional water Rankine cycle

International Nuclear Information System (INIS)

Latge, Christian; Simon, Nicole

2006-01-01

The Sodium Fast Reactor is a very promising candidate for the development of Fast Neutron Reactors. It is well known owing to its wide development since the 1950's, throughout all countries involved in the development of nuclear power plants. The development of Sodium-cooled fast neutron reactors is possible due to its very attractive sodium, nuclear, physical and even some of its chemical properties. Nevertheless, the operational feedback has shown that the concept has several drawbacks: difficulties for In-Service Inspection and Repair operations due to the sodium opacity and possible detrimental effects of its reactivity with air and water when the heat conversion is performed with a conventional Rankine cycle. Moreover, the various design projects have shown some difficulties in enhancing its competitiveness with regards to existing NPPs without any new innovative options, i.e. the possibility of suppressing the intermediate circuits and/or the development of an optimized energy conversion system. The Supercritical CO 2 Brayton Cycle option for the energy conversion has been widely suggested because of its high thermodynamic efficiency (over 40%), its potential compactness of the Balance Of Plant equipment due to the small-sized turbo machinery system, and for its applicability to both Direct or Indirect Cycle (Na, PbBi, He) assuming the hypothesis that the Supercritical CO 2 -Na interaction has less serious potential consequences than sodium-water consequences in the conventional Rankine cycle. Within the framework of the SMFR (Small Modular Fast Reactor) project, developed jointly by Argonne National Laboratory (ANL-USA), the 'Commissariat a l'Energie Atomique' (CEA) and Japan Atomic Energy Agency (JAEA, formerly Japan Nuclear Cycle development), this option has been selected and investigated. This paper deals with the study of the interaction between Na and CO 2 , based on a literature review: the result of this study will allow the definition of R and D

The new ATLAS Fast Calorimeter Simulation

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00176100; The ATLAS collaboration

2016-01-01

The physics and performance studies of the ATLAS detector at the Large Hadron Collider re- quire a large number of simulated events. A GEANT4 based detailed simulation of the ATLAS calorimeter systems is highly CPU intensive and such resolution is often unnecessary. To reduce the calorimeter simulation time by a few orders of magnitude, fast simulation tools have been developed. The Fast Calorimeter Simulation (FastCaloSim) provides a parameterised simulation of the particle energy response at the calorimeter read-out cell level. In Run 1, about 13 billion events were simulated in ATLAS, out of which 50% were produced using fast simulation. For Run 2, a new parameterisation is being developed to improve the original version: it incorporates developments in geometry and physics lists during the last five years and benefits from the knowledge acquired from the Run 1 data. The algorithm uses machine learning techniques to improve the parameterisations and to optimise the amount of information to be stored in the...

Real-time spot size camera for pulsed high-energy radiographic machines

International Nuclear Information System (INIS)

Watson, S.A.

1993-01-01

The focal spot size of an x-ray source is a critical parameter which degrades resolution in a flash radiograph. For best results, a small round focal spot is required. Therefore, a fast and accurate measurement of the spot size is highly desirable to facilitate machine tuning. This paper describes two systems developed for Los Alamos National Laboratory's Pulsed High-Energy Radiographic Machine Emitting X-rays (PHERMEX) facility. The first uses a CCD camera combined with high-brightness floors, while the second utilizes phosphor storage screens. Other techniques typically record only the line spread function on radiographic film, while systems in this paper measure the more general two-dimensional point-spread function and associated modulation transfer function in real time for shot-to-shot comparison

Production of high specific activity 27Mg by fast neutron irradiation and recoil-aided leaching

International Nuclear Information System (INIS)

Wierczinski, B.; Goeij, J.J.M. de; Volkers, K.J.

2000-01-01

High specific activity 27 Mg was produced via recoil-aided leaching from alumina in aqueous medium during irradiation with fast neutrons from a nuclear reactor. After irradiation the aqueous medium was passed through an IC-chelate column, the 24 Na formed during irradiation was removed by elution with 0.25 ml . l -1 sodium acetate and subsequently the 27 Mg was eluted with 2 mol . l -1 hydrochloric acid. Irradiation of alumina with a particle size of 3 μm and a specific surface area of 100 m 2 . g -1 in Milli-Q Plus Water yielded 90% of the total 27 Mg activity produced. Under standard conditions activities of about 8 . 10 5 Bq and specific activities of ca. 10 13 Bq . mol -1 were obtained at the end of irradiation. The standard working conditions involved irradiation of 200 mg alumina dispersed in 0.5 ml liquid in a fast neutron flux of 3 . 10 15 m -2 . s -1 for 15 min, a waiting time of 10 min, and a processing time of 15 minutes. Various alumina samples with different particle sizes and specific surfaces were tested, and the 27 Mg yields were fitted to a mathematical function. Since the high leaching yields cannot only be explained by recoil only, other phenomena such as diffusion and leaching aided by the high hydration energy of the Mg 2+ ion are probably involved. (orig.)

Temporal trends in fast-food restaurant energy, sodium, saturated fat, and trans fat content, United States, 1996-2013.

Science.gov (United States)

Urban, Lorien E; Roberts, Susan B; Fierstein, Jamie L; Gary, Christine E; Lichtenstein, Alice H

2014-12-31

Excess intakes of energy, sodium, saturated fat, and trans fat are associated with increased risk for cardiometabolic syndrome. Trends in fast-food restaurant portion sizes can inform policy decisions. We examined the variability of popular food items in 3 fast-food restaurants in the United States by portion size during the past 18 years. Items from 3 national fast-food chains were selected: French fries, cheeseburgers, grilled chicken sandwich, and regular cola. Data on energy, sodium, saturated fat, and trans fat content were collated from 1996 through 2013 using an archival website. Time trends were assessed using simple linear regression models, using energy or a nutrient component as the dependent variable and the year as the independent variable. For most items, energy content per serving differed among chain restaurants for all menu items (P ≤ .04); energy content of 56% of items decreased (β range, -0.1 to -5.8 kcal) and the content of 44% increased (β range, 0.6-10.6 kcal). For sodium, the content of 18% of the items significantly decreased (β range, -4.1 to -24.0 mg) and the content for 33% increased (β range, 1.9-29.6 mg). Absolute differences were modest. The saturated and trans fat content, post-2009, was modest for French fries. In 2013, the energy content of a large-sized bundled meal (cheeseburger, French fries, and regular cola) represented 65% to 80% of a 2,000-calorie-per-day diet, and sodium content represented 63% to 91% of the 2,300-mg-per-day recommendation and 97% to 139% of the 1,500-mg-per-day recommendation. Findings suggest that efforts to promote reductions in energy, sodium, saturated fat, and trans fat intakes need to be shifted from emphasizing portion-size labels to additional factors such as total calories, frequency of eating, number of items ordered, menu choices, and energy-containing beverages.

Processing of Bi-2212 and Nb$_3$Sn studied in situ by high energy synchrotron diffraction and micro-tomography

CERN Document Server

Kadar, Julian

Next generation superconducting wires have been studied to obtain more information on the evolution of phase growth, crystallite size and strain state during wire processing. The high energy scattering beam line ID15 at the European Synchrotron Radiation Facility provides a very high flux of high energy photons for very fast in situ X-ray diffraction and micro-tomography studies of Bi-2212/Ag and Nb$_3$S/Cu wire samples. The typical wire processing conditions could be imitated in the X-ray transparent furnace at ID15 for diffraction and tomography studies. Efficient data analysis is mandatory in order to handle the very fast data acquisition rate. For this purpose an Excel-VBA based program was developed that allows a semi-automated fitting and tracking of peaks with pre-set constraints. With this method, more than one thousand diffraction patterns have been analysed to extract d-spacing, peak intensity and peak width values. X ray absorption micro tomograms were recorded simultaneously with the X-ray diffrac...

Biomass a fast growing energy resource

International Nuclear Information System (INIS)

Hansen, Ulf

2003-01-01

Biomass as an energy resource is as versatile as the biodiversity suggests. The global net primary production, NPP, describes the annual growth of biomass on land and in the seas. This paper focuses on biomass grown on land. A recent estimate for the NPP on land is 120 billion tons of dry matter. How much of this biomass are available for energy purposes? The potential contribution of wood fuel and energy plants from sustainable production is limited to some 5% of NPP, i.e. 6 Bt. One third of the potential is energy forests and energy plantations which at present are not economic. One third is used in rural areas as traditional fuel. The remaining third would be available for modern biomass energy conversion. Biomass is assigned an expanding role as a new resource in the world's energy balance. The EU has set a target of doubling the share of renewable energy sources by 2010. For biomass the target is even more ambitious. The challenge for biomass utilization lies in improving the technology for traditional usage and expanding the role into other areas like power production and transportation fuel. Various technologies for biomass utilization are available among those are combustion, gasification, and liquefaction. Researchers have a grand vision in which the chemical elements in the hydrocarbon molecules of biomass are separated and reformed to yield new tailored fuels and form the basis for a new world economy. The vision of a new energy system based on fresh and fossilized biomass to be engineered into an environmentally friendly and sustainable fuel is a conceivable technical reality. One reason for replacing exhaustible fossil fuels with biomass is to reduce carbon emissions. The most efficient carbon dioxide emission reduction comes from replacing brown coal in a steam-electric unit, due to the efficiency of the thermal cycle and the high carbon intensity of the coal. The smallest emission reduction comes from substituting natural gas. (BA)

Fast-ion transport in qmin>2, high-β steady-state scenarios on DIII-D

International Nuclear Information System (INIS)

Holcomb, C. T.; Heidbrink, W. W.; Collins, C.; Ferron, J. R.; Van Zeeland, M. A.; Garofalo, A. M.; Bass, E. M.; Luce, T. C.; Pace, D. C.; Solomon, W. M.; Mueller, D.; Grierson, B.; Podesta, M.; Gong, X.; Ren, Q.; Park, J. M.; Kim, K.; Turco, F.

2015-01-01

Results from experiments on DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] aimed at developing high β steady-state operating scenarios with high-q min confirm that fast-ion transport is a critical issue for advanced tokamak development using neutral beam injection current drive. In DIII-D, greater than 11 MW of neutral beam heating power is applied with the intent of maximizing β N and the noninductive current drive. However, in scenarios with q min >2 that target the typical range of q 95 = 5–7 used in next-step steady-state reactor models, Alfvén eigenmodes cause greater fast-ion transport than classical models predict. This enhanced transport reduces the absorbed neutral beam heating power and current drive and limits the achievable β N . In contrast, similar plasmas except with q min just above 1 have approximately classical fast-ion transport. Experiments that take q min >3 plasmas to higher β P with q 95 = 11–12 for testing long pulse operation exhibit regimes of better than expected thermal confinement. Compared to the standard high-q min scenario, the high β P cases have shorter slowing-down time and lower ∇β fast , and this reduces the drive for Alfvénic modes, yielding nearly classical fast-ion transport, high values of normalized confinement, β N , and noninductive current fraction. These results suggest DIII-D might obtain better performance in lower-q 95 , high-q min plasmas using broader neutral beam heating profiles and increased direct electron heating power to lower the drive for Alfvén eigenmodes

Follow-up of high energy neutrinos detected by the ANTARES telescope

Science.gov (United States)

Mathieu, Aurore

2016-04-01

The ANTARES telescope is well-suited to detect high energy neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky with a high duty cycle. Potential neutrino sources are gamma-ray bursts, core-collapse supernovae and flaring active galactic nuclei. To enhance the sensitivity of ANTARES to such sources, a detection method based on follow-up observations from the neutrino direction has been developed. This program, denoted as TAToO, includes a network of robotic optical telescopes (TAROT, Zadko and MASTER) and the Swift-XRT telescope, which are triggered when an "interesting" neutrino is detected by ANTARES. A follow-up of special events, such as neutrino doublets in time/space coincidence or a single neutrino having a very high energy or in the specific direction of a local galaxy, significantly improves the perspective for the detection of transient sources. The analysis of early and long term follow-up observations to search for fast and slowly varying transient sources, respectively, has been performed and the results covering optical and X-ray data are presented in this contribution.

Mesooptical Fourier transform microscope - a new device for high energy physics

International Nuclear Information System (INIS)

Astakhov, A.Ya.; Batusov, Yu.A.; Bencze, Gy.L.; Farago, I.; Kisvaradi, A.; Molnar, L.; Soroko, L.M.; Vegh, J.

1988-01-01

A new device for high energy physics, Mesooptical Fourier Transform Microscope (MFTM), designed for observation of straight-line particle tracks in nuclear emulsion is described. The MFTM works without any mechanical or electronical depth scanning and can be considered as a selectively viewing eye. The computer controlled system containing MFTM as the main unit is given. This system can be used for fast search particle tracks and events produced by high energy neutrinos from accelerators. The results of the first experimental test of the computer controlled MFTM are presented. The performances of this system are described and discussed. It is shown that the angular resolution of the MFTM is 1 angular minute and the measurement time is equal to 30 ms. As all operations in the MFTM go without any depth scanning this new system works at least two orders of magnitude faster than any known system with a traditional optical microscope

An option for the Brazilian nuclear project: necessity of fast breeder reactors and core design for an experimental fast reactor

International Nuclear Information System (INIS)

Ishiguro, Y.

1983-01-01

In order to assure the continued utilization of fission energy, development of fast breeder reactors (FBRs) is a necessity. Binary fueled LMFBRs are proposed as the best type for future Brazilian nuclear systems. The inherent safety characteristics are superior to current FBRs and an efficient utilization of the abundant thorium is possible. A first step and a basic tool for the development of FBR technologies is the construction and operation of an experimental fast reactor (EFR). A series of core designs for a 90 MW EFR is studied and possible options and the magnitudes of principal parameters are identified. Flexible modifications of the core and sufficiently high fast fluxes for fuel and materials irradiations appear possible. (Author) [pt

A Novel Supercapacitor/Lithium-Ion Hybrid Energy System with a Fuzzy Logic-Controlled Fast Charging and Intelligent Energy Management System

Directory of Open Access Journals (Sweden)

Muhammad Adil Khan

2018-05-01

Full Text Available The electric powered wheelchair (EPW is an essential assistive tool for people with serious injuries or disability. This manuscript describes the validation of applied research for reducing the charging time of an electric wheelchair using a hybrid electric system (HES composed of a supercapacitor (SC bank and a lithium-ion battery with a fuzzy logic controller (FLC-based fast charging system for Li-ion batteries and a fuzzy logic-based intelligent energy management system (FLIEMS for controlling the power flow within the HES. The fast charging FLC was designed to drive the voltage difference (Vd among the different cells of a multi-cell battery and the cell voltage (Vc of an individual cell. These parameters (voltage difference and cell voltage were used as input voltages to reduce the charge time and activate a bypass equalization (BPE scheme. BPE was introduced in this paper so that the battery operates within the safe voltage range. For SC/Li-ion HES, the FLIEMS presented in this paper controls the bi-directional power flow to smooth the power extracted from Li-ion batteries. Moreover, a dual active bridge isolated bidirectional DC converter (DAB-IBDC was used for power conversion. The DAB-IBDC presented in this paper has the characteristics of galvanic isolation, and high power conversion efficiency compared to the conventional converter circuits due to the reduced reverse power flow and current stresses.

High-burn-up fuels for fast reactors. Past experience and novel applications

International Nuclear Information System (INIS)

Weaver, Kevan D.; Gilleland, John; Whitmer, Charles; Zimmerman, George

2009-01-01

Fast reactors in the U.S. routinely achieved fuel burn-ups of 10%, with some fuel able to reach peak burn-ups of 20%, notably in the Experimental Breeder Reactor II and the Fast Flux Test Facility. Maximum burn-up has historically been constrained by chemical and mechanical interactions between the fuel and its cladding, and to some extent by radiation damage and thermal effects (e.g., radiation-induced creep, thermal creep, and radiation embrittlement) that cause the cladding to weaken. Although fast reactors have used several kinds of fuel - including oxide, metal alloy, carbide, and nitride - the vast majority of experience with fast reactors has been using oxide (including mixed oxide) and metal-alloy fuels based on uranium. Our understanding of high-burn-up operation is also limited by the fact that breeder reactor programs have historically assumed that their fuel would eventually undergo reprocessing; the programs thus have not made high burn-up a top priority. Recently a set of novel designs have emerged for fast reactors that require little initial enrichment and no reprocessing. These reactors exploit a concept known as a traveling wave (sometimes referred to as a breed-and-burn wave, fission wave, or nuclear-burning wave). By breeding and using its own fuel in place as it operates, a traveling-wave reactor can obtain burn-ups that approach 50%, well beyond the current base of knowledge and experience. Our computational work on the physics of traveling-wave reactors shows that they require metal-alloy fuel to provide the margins of reactivity necessary to sustain a breed-and-burn wave. This paper reviews operating experience with high-burn-up fuels and the technical feasibility of moving to a qualitatively new burn-up regime. We discuss our calculations on traveling-wave reactors, including those concerning the possible use of thorium. The challenges associated with high burn-up and fluence in fuels and materials are also discussed. (author)

Performance of a fast low noise front-end preamplifier for the MAGIC imaging Cherenkov telescope

International Nuclear Information System (INIS)

Blanch, O.; Blanchot, G.; Bosman, M.

1999-01-01

The observation of high energy cosmic gamma rays with an energy threshold of 15 GeV using the proposed MAGIC ground based air imaging Cherenkov telescope requires the development of new low noise fast preamplifiers for the camera photosensors. The speed and noise performance of a transimpedance preamplifier that resolves the multi photoelectron peaks from a hybrid photomultiplier with a peaking time below 7 ns is presented. The new front-end circuit is designed with RF low noise bipolar transistors and provides fast output pulses that allow for fast trigger settings

Response of E. coli AB2463 recA to fast neutron beams with mean energies in the range 4 to 27 MeV

Energy Technology Data Exchange (ETDEWEB)

Redpath, J L [Michael Reese Hospital, Chicago, Ill. (USA)

1978-07-01

The radiosensitivity of E.coli AB2463 recA, given as the reciprical of the mean lethal dose, Do/sup -1/, has been shown to be the same for four fast neutron beams with widely different energy spectra. It is proposed that this organism can be used to intercompare dosimetry on fast neutron beams with mean energies in the range 4 to 25 MeV with an accuracy of +- 5%.

Learning to discover: machine learning in high-energy physics

CERN Multimedia

CERN. Geneva

2014-01-01

In this talk we will survey some of the latest developments in machine learning research through the optics of potential applications in high-energy physics. We will then describe three ongoing projects in detail. The main subject of the talk is the data challenge we are organizing with ATLAS on optimizing the discovery significance for the Higgs to tau-tau channel. Second, we describe our collaboration with the LHCb experiment on designing and optimizing fast multi-variate techniques that can be implemented as online classifiers in triggers. Finally, we will sketch a relatively young project with the ILC (Calice) group in which we are attempting to apply deep learning techniques for inference on imaging calorimeter data.

ORR core re-configuration measurements to increase the fast neutron flux in the Magnetic Fusion Energy (MFE) experiments

International Nuclear Information System (INIS)

Hobbs, R.W.; Stinnett, R.M.; Sims, T.M.

1985-06-01

A study has been made of the relative increases obtainable in the fast neutron flux in the Magnetic Fusion Energy (MFE) experiment positions by reconfiguring the current ORR core. The study was made at the request of the MFE program to examine the percentage increase possible in the current displacement per atom (dpa) rate (assumed proportional to the fast flux). The principle methods investigated to increase the fast flux consisted of reducing the current core size (number of fuel elements) to increase the core average power density and arrangement of the fuel elements in the reduced-size core to tilt the core power distribution towards the MFE positions. The study concluded that fast fluxes in the E-3 core position could be increased by approximately 15 to 20% over current values and in E-5 by approximately 45 to 55%

Performance evaluation of novel LaBr{sub 3}(Ce) scintillator geometries for fast-timing applications

Energy Technology Data Exchange (ETDEWEB)

Vedia, V., E-mail: mv.vedia@ucm.es [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, 28040 Madrid (Spain); Carmona-Gallardo, M.; Fraile, L.M. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, 28040 Madrid (Spain); Mach, H. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, 28040 Madrid (Spain); National Centre for Nuclear Research, Division for Nuclear Physics, BP1, Warsaw (Poland); Udías, J.M. [Grupo de Física Nuclear, Facultad de CC. Físicas, Universidad Complutense, CEI Moncloa, 28040 Madrid (Spain)

2017-06-11

We evaluate the performance of two LaBr{sub 3}(Ce) crystals that were produced with special geometries, aimed at enhancing the scintillation light collection and thus the time resolution. Their design was motivated by the construction of high-performance fast-timing arrays like the FAst TIMing array for DESPEC (FATIMA), which demands a high packing factor in addition to good time and energy resolutions. Energy resolution and efficiency were measured using standard calibration sources. Timing measurements were performed at {sup 60}Co and {sup 22}Na γ-energies against a fast BaF{sub 2} reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the constant fraction discriminator parameters. Monte Carlo simulations using the Geant4 toolkit were performed in order to achieve a better understanding of how the new geometries affect the light transport and thus the performance of the crystals. It is found that the conical-shaped LaBr{sub 3}(Ce) crystals are optimal for fast-timing applications and for the construction of arrays such as FATIMA.

High-pressure {sup 3}He-Xe gas scintillators for simultaneous detection of neutrons and gamma rays over a large energy range

Energy Technology Data Exchange (ETDEWEB)

Tornow, W., E-mail: tornow@tunl.duke.edu [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Esterline, J.H. [Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Leckey, C.A. [Department of Physics, The College of William and Mary, Williamsburg, VA 23187 (United States); Weisel, G.J. [Department of Physics, Penn State Altoona, Altoona, PA 16601 (United States)

2011-08-11

We report on features of high-pressure {sup 3}He-Xe gas scintillators which have not been sufficiently addressed in the past. Such gas scintillators can be used not only for the efficient detection of low-energy neutrons but at the same time for the detection and identification of {gamma}-rays as well. Furthermore, {sup 3}He-Xe gas scintillators are also very convenient detectors for fast neutrons in the 1-10 MeV energy range and for high-energy {gamma}-rays in the 7-15 MeV energy range. Due to their linear pulse-height response and self calibration via the {sup 3}He(n,p){sup 3}H reaction, neutron and {gamma}-ray energies can easily be determined in this high-energy regime.

Accelerated Irradiations for High Dose Microstructures in Fast Reactor Alloys

Energy Technology Data Exchange (ETDEWEB)

Jiao, Zhijie [Univ. of Michigan, Ann Arbor, MI (United States)

2017-03-31

The objective of this project is to determine the extent to which high dose rate, self-ion irradiation can be used as an accelerated irradiation tool to understand microstructure evolution at high doses and temperatures relevant to advanced fast reactors. We will accomplish the goal by evaluating phase stability and swelling of F-M alloys relevant to SFR systems at very high dose by combining experiment and modeling in an effort to obtain a quantitative description of the processes at high and low damage rates.

Fast protection circuit for 1 MW Klystron based RF system of Low Energy High Intensity Proton Accelerator (LEHIPA)

International Nuclear Information System (INIS)

Shrotriya, Sandip; Shiju, A.; Patel, N.R.; Pande, Manjiri; Singh, P.

2014-01-01

This paper describes the details of a hardwired protection circuit designed and developed for 1 MW Klystron based Radio Frequency (RF) System. The hardwired protection circuit protects the klystron from fault conditions occurring in high power DC supplies, other bias supplies and inside the klystron itself. Fast response of the order of 1-2 microseconds is necessary in case of critical signals for the protection of such a high power system. The system needs to handle around 10 critical signals comprising of optical signals and different digital signals. In case of malfunction in the existing controller based interlock and protection system, klystron will be protected by this hardwired protection circuit. The hardwired circuit will provide redundant protection and protect the klystron from damage. This circuit and controller based protection system are operating in parallel. This paper describes details of a purely hardwired protection circuit developed for critical signals for achieving reliability and faster response time requirements of the RF system. (author)

High energy neutron radiography

International Nuclear Information System (INIS)

Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

1996-01-01

High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos

Neural networks and cellular automata in experimental high energy physics

Energy Technology Data Exchange (ETDEWEB)

Denby, B

1988-06-01

Within the past few years, two novel computing techniques, cellular automata and neural networks, have shown considerable promise in the solution of problems of a very high degree of complexity, such as turbulent fluid flow, image processing, and pattern recognition. Many of the problems faced in experimental high energy physics are also of this nature. Track reconstruction in wire chambers and cluster finding in cellular calorimeters, for instance, involve pattern recognition and high combinatorial complexity since many combinations of hits or cells must be considered in order to arrive at the final tracks or clusters. Here we examine in what way connective network methods can be applied to some of the problems of experimental high energy physics. It is found that such problems as track and cluster finding adapt naturally to these approaches. When large scale hard-wired connective networks become available, it will be possible to realize solutions to such problems in a fraction of the time required by traditional methods. For certain types of problems, faster solutions are already possible using model networks implemented on vector or other massively parallel machines. It should also be possible, using existing technology, to build simplified networks that will allow detailed reconstructed event information to be used in fast trigger decisions.

Neural networks and cellular automata in experimental high energy physics

International Nuclear Information System (INIS)

Denby, B.

1988-01-01

Within the past few years, two novel computing techniques, cellular automata and neural networks, have shown considerable promise in the solution of problems of a very high degree of complexity, such as turbulent fluid flow, image processing, and pattern recognition. Many of the problems faced in experimental high energy physics are also of this nature. Track reconstruction in wire chambers and cluster finding in cellular calorimeters, for instance, involve pattern recognition and high combinatorial complexity since many combinations of hits or cells must be considered in order to arrive at the final tracks or clusters. Here we examine in what way connective network methods can be applied to some of the problems of experimental high energy physics. It is found that such problems as track and cluster finding adapt naturally to these approaches. When large scale hard-wired connective networks become available, it will be possible to realize solutions to such problems in a fraction of the time required by traditional methods. For certain types of problems, faster solutions are already possible using model networks implemented on vector or other massively parallel machines. It should also be possible, using existing technology, to build simplified networks that will allow detailed reconstructed event information to be used in fast trigger decisions. (orig.)

Dynamics of fast ions in Tokamaks

International Nuclear Information System (INIS)

Helander, P.

1994-01-01

Fast ions play a prominent role in the heating of tokamak plasmas by, e.g. neutral-beam injection, ion-cyclotron-resonance heating, and alpha-particle heating. In this thesis, a number of physical and mathematical problems concerning the dynamics of fast ions in tokamaks are addressed. First, the motion under adiabatic perturbations is studied. The frequencies of instabilities excited in tokamaks sometimes vary slowly with time. The existence of an adiabatic invariant of particle motion in such circumstances is shown to lead to a rapid convection of particles in the radial direction. Generalized adiabatic invariants are constructed for systems where the slowly varying parameter is subjected to small, but rapidly varying, fluctuations. Second, the onset of stochastic motion under resonant perturbations is considered. It is shown that the finite width of fast-ion drift orbits significantly affects the threshold for stochastic motion caused by magnetic field ripple or ion-cyclotron-resonance heating. Finite-orbit-width effects are also shown to reduce the strength of resonant interaction between alpha particles and internal kink modes. Third, the diffusive motion in the stochastic regime is analysed mathematically. Monte Carlo operators for the motion on long time-scales are constructed, and the validity of the quasilinear diffusion coefficient is examined. Finally, the effects of close ion collisions are investigated. It is demonstrated that close encounters with fast ions produce a high-energy tail in the distribution functions of impurity ions, and that close collisions between fusion-generated alpha particles give rise to a population of such particles with energies extending up to twice the birth energy. 44 refs

Development of fast pulsed power driver for radiography and Z-pinch

International Nuclear Information System (INIS)

Qiu Aici; Sun Fengju

2008-01-01

Z-pinch and flash X-ray radiography have an important application in inertial confine fusion (ICF) and nuclear radiation effects simulation and high performance hydrodynamic test, etc. Z-pinch ICF and multi-pulse multi-axis high energy X-ray radiography put forward a huge challenge for pulsed power driver, so the direct-driven-load fast pulsed power driver are developed actively in home and abroard. The paper summarized the recent advances and developing trends of the fast pulsed power driver based on fast Marx(FMG) and fast linear transformer driver (LTD), and analysized the advantages and disadvantages and restricting factors about FMG and FLTD and their key technologies, then introduced the state-of-arts on the investigation in Northwest Institute of Nuclear Technology. In the end, the paper presented some advices and views about studying fast pulsed power driver applied to Z-pinch and flash X-ray radiography in home. (authors)

High flux-fluence measurements in fast reactors

International Nuclear Information System (INIS)

Lippincott, E.P.; Ulseth, J.A.

1977-01-01

Characterization of irradiation environments for fuels and materials tests in fast reactors requires determination of the neutron flux integrated over times as long as several years. An accurate integration requires, therefore, passive dosimetry monitors with long half-life or stable products which can be conveniently measured. In addition, burn-up, burn-in, and burn-out effects must be considered in high flux situations and use of minimum quantities of dosimeter materials is often desirable. These conditions force the use of dosimeter and dosimeter container designs, measured products, and techniques that are different from those that are used in critical facilities and other well-characterized benchmark fields. Recent measurements in EBR-II indicate that high-accuracy results can be attained and that tie-backs to benchmark field technique calibrations can be accomplished

The Fast Flux Test Facility built on safety

International Nuclear Information System (INIS)

1989-01-01

No other high-tech industry has grown as fast as the nuclear industry. The information available to the general public has not kept pace with the rapid growth of nuclear data---its growth has outpaced its media image and the safety of nuclear facilities has become a highly debated issue. This book is an attempt to bridge the gap between the high-tech information of the nuclear industry and its understanding by the general public. It explains the three levels of defense at the Fast Flux Test Facility (FFTF) and why these levels provide an acceptable margin to protect the general public and on-site personnel, while achieving FFTF's mission to provide research and development for the US Department of Energy

Distributed Cooperative Control of Multi Flywheel Energy Storage System for Electrical Vehicle Fast Charging Stations

DEFF Research Database (Denmark)

Sun, Bo; Dragicevic, Tomislav; Quintero, Juan Carlos Vasquez

2015-01-01

Plug-in electrical vehicles will play a critical role in future smart grid and sudden connection of electrical vehicles chargers may cause huge power-peaks with high slew-rates on grid. In order to cope with this issue, this paper applies a distributed cooperative control for fast charging station...... with dedicated paralleled flywheel-based energy storage system. The distributed DC-bus signaling method is employed in the power coordination of grid and flywheel converters, and a distributed secondary controller generates DC voltage correction term to adjust the local voltage set-point through a dynamic...... consensus based voltage observer by communicating with its neighbors. The control system can realize the power balancing and DC voltage regulation with low reliance on communications. Finally, real-time hardware-in-the-loop results have been reported in order to verify the feasibility of proposed approach....

The Molten Salt Fast Reactor as Highly Efficient Transmutation System

International Nuclear Information System (INIS)

Merk, B.; Rohde, U.; Scholl, S.

2013-01-01

Conclusion and future steps: • MSFR offers very attractive features for efficient transmutation; • significant advantages due to liquid fuel and online refuelling and reprocessing; • significant developments are required on the way to application; • system is very promising for transmutation; • development of a safety approach for liquid fuel reactors (RSWG); • investigation of possibilities to solve the “last transmuter” problem (ICAPP2013) – as future for countries envisaging nuclear phase out or no transition to fast reactor fleet for energy production; • establishing of a strong group “MSFR for transmutation”; • development of a transmutation optimized design

Energy potential from rice husk through direct combustion and fast pyrolysis: A review.

Science.gov (United States)

Quispe, Isabel; Navia, Rodrigo; Kahhat, Ramzy

2017-01-01

Rapid population growth and consumption of goods and services imply that demand for energy and resources increases continuously. Energy consumption linked to non-renewable resources contributes to greenhouse gas emissions and enhances resource depletion. In this context, the use of agricultural solid residues such as rice husk, coffee husk, wheat straw, sugar cane bagasse, among others, has been widely studied as an alternative energy source in order to decrease the use of fossil fuels. However, rice husk is among those agricultural residues that are least used to obtain energy in developing countries. Approximately 134 million tonnes of rice husk are produced annually in the world, of which over 90% are burned in open air or discharged into rivers and oceans in order to dispose of them. This review examines the energetic potential of agricultural residues, focused on rice husk. The review describes direct combustion and fast pyrolysis technologies to transform rice husk into energy considering its physical and chemical properties. In addition, a review of existing studies analyzing these technologies from an environmental life cycle thinking perspective, contributing to their sustainable use, is performed. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-performance rechargeable batteries with fast solid-state ion conductors

Energy Technology Data Exchange (ETDEWEB)

Farmer, Joseph C.

2017-06-27

A high-performance rechargeable battery using ultra-fast ion conductors. In one embodiment the rechargeable battery apparatus includes an enclosure, a first electrode operatively connected to the enclosure, a second electrode operatively connected to the enclosure, a nanomaterial in the enclosure, and a heat transfer unit.

One day of moderate energy deficit reduces fasting and postprandial triacylglycerolemia in women: the role of calorie restriction and exercise.

Science.gov (United States)

Maraki, Maria; Magkos, Faidon; Christodoulou, Nektarios; Aggelopoulou, Niki; Skenderi, Katerina P; Panagiotakos, Demosthenes; Kavouras, Stavros A; Sidossis, Labros S

2010-08-01

Fasting and postprandial hypertriacylglycerolemia are important cardiovascular risk factors in women. We sought to examine the effects of acute (1 day), moderate ( approximately 2 MJ) energy deficit induced by calorie restriction, exercise, or combination of both on fasting and postprandial triacylglycerol (TAG) metabolism in women. Six healthy premenopausal women performed four oral fat tolerance tests in the morning after a day of a) rest (control), b) calorie restriction ( approximately 2 MJ), c) exercise (net deficit of approximately 2 MJ) and d) calorie restriction-plus-exercise (total energy deficit of approximately 2 MJ). All energy deficit trials significantly reduced fasting and postprandial total plasma TAG concentrations by 15-23% and 12-23%, respectively, and triacylglycerol-rich lipoprotein TAG concentrations by 37-43% and 25-39%, respectively, compared with the control condition (Pwomen. Exercise elicits a somewhat greater effect than calorie restriction in the postprandial state. The acute effect of diet and exercise should be taken into account when studying the long-term effects of weight loss and exercise training on TAG metabolism. Copyright 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Synchronous timing of multi-energy fast beam extraction during a single AGS cycle

International Nuclear Information System (INIS)

Gabusi, J.; Naase, S.

1985-01-01

Synchronous triggering of fast beams is required because the field of Kicker Magnets must rise within the open space between one beam bunch and the next. Within the Brookhaven AGS, Fast Extracted Beam (FEB) triggering combines nominal timing, based on beam energy with bunch-to-bunch synchronization, based on the accelerating rf waveform. During beam acceleration, a single bunch is extracted at 22 GeV/c and within the same AGS cycle, the remaining eleven bunches are extracted at 28.4 GeV/c. When the single bunch is extracted, a ''hole'', which is left in the remaining circulating beam, can appear in random locations within the second extraction during successive AGS cycles. To overcome this problem, a synchronous rf/12 counting scheme and logic circuitry are used to keep track of the bunch positions relative to each other, and to place the ''hole'' in any desired location within the second extraction. The rf/12 signal is used also to synchronize experimenters triggers

Fast ions and momentum transport in JET tokamak plasmas

International Nuclear Information System (INIS)

Salmi, A.

2012-01-01

Fast ions are an inseparable part of fusion plasmas. They can be generated using electromagnetic waves or injected into plasmas as neutrals to heat the bulk plasma and to drive toroidal rotation and current. In future power plants fusion born fast ions deliver the main heating into the plasma. Understanding and controlling the fast ions is of crucial importance for the operation of a power plant. Furthermore, fast ions provide ways to probe the properties of the thermal plasma and get insight of its confinement properties. In this thesis, numerical code packages are used and developed to simulate JET experiments for a range of physics issues related to fast ions. Namely, the clamping fast ion distribution at high energies with RF heating, fast ion ripple torque generation and the toroidal momentum transport properties using NBI modulation technique are investigated. Through a comparison of numerical simulations and the JET experimental data it is shown that the finite Larmor radius effects in ion cyclotron resonance heating are important and that they can prevent fast ion tail formation beyond certain energy. The identified mechanism could be used for tailoring the fast ion distribution in future experiments. Secondly, ASCOT simulations of NBI ions in a ripple field showed that most of the reduction of the toroidal rotation that has been observed in the JET enhanced ripple experiments could be attributed to fast ion ripple torque. Finally, fast ion torque calculations together with momentum transport analysis have led to the conclusion that momentum transport in not purely diffusive but that a convective component, which increases monotonically in radius, exists in a wide range of JET plasmas. Using parameter scans, the convective transport has been shown to be insensitive to collisionality and q-profile but to increase strongly against density gradient. (orig.)

Fast ions and momentum transport in JET tokamak plasmas

Energy Technology Data Exchange (ETDEWEB)

Salmi, A.

2012-07-01

Fast ions are an inseparable part of fusion plasmas. They can be generated using electromagnetic waves or injected into plasmas as neutrals to heat the bulk plasma and to drive toroidal rotation and current. In future power plants fusion born fast ions deliver the main heating into the plasma. Understanding and controlling the fast ions is of crucial importance for the operation of a power plant. Furthermore, fast ions provide ways to probe the properties of the thermal plasma and get insight of its confinement properties. In this thesis, numerical code packages are used and developed to simulate JET experiments for a range of physics issues related to fast ions. Namely, the clamping fast ion distribution at high energies with RF heating, fast ion ripple torque generation and the toroidal momentum transport properties using NBI modulation technique are investigated. Through a comparison of numerical simulations and the JET experimental data it is shown that the finite Larmor radius effects in ion cyclotron resonance heating are important and that they can prevent fast ion tail formation beyond certain energy. The identified mechanism could be used for tailoring the fast ion distribution in future experiments. Secondly, ASCOT simulations of NBI ions in a ripple field showed that most of the reduction of the toroidal rotation that has been observed in the JET enhanced ripple experiments could be attributed to fast ion ripple torque. Finally, fast ion torque calculations together with momentum transport analysis have led to the conclusion that momentum transport in not purely diffusive but that a convective component, which increases monotonically in radius, exists in a wide range of JET plasmas. Using parameter scans, the convective transport has been shown to be insensitive to collisionality and q-profile but to increase strongly against density gradient. (orig.)

Decreases in fasting leptin and insulin concentrations after acute energy restriction and subsequent compensation in food intake

NARCIS (Netherlands)

Mars, M.; Graaf, de C.; Groot, de C.P.G.M.; Kok, F.J.

2005-01-01

The decrease in leptin after energy restriction is a starvation signal to the brain. Several studies have found an association between this decrease and subjective appetite; however, no solid data are available on the acute decrease in fasting leptin concentration and subsequent caloric

Energy consumption in Hodgkin–Huxley type fast spiking neuron model exposed to an external electric field

Directory of Open Access Journals (Sweden)

K. Usha

2016-09-01

Full Text Available This paper evaluates the change in metabolic energy required to maintain the signalling activity of neurons in the presence of an external electric field. We have analysed the Hodgkin–Huxley type conductance based fast spiking neuron model as electrical circuit by changing the frequency and amplitude of the applied electric field. The study has shown that, the presence of electric field increases the membrane potential, electrical energy supply and metabolic energy consumption. As the amplitude of applied electric field increases by keeping a constant frequency, the membrane potential increases and consequently the electrical energy supply and metabolic energy consumption increases. On increasing the frequency of the applied field, the peak value of membrane potential after depolarization gradually decreases as a result electrical energy supply decreases which results in a lower rate of hydrolysis of ATP molecules.

Effects of high thermal and high fast fluences on the mechanical properties of type 6061 aluminum in the HFBR

International Nuclear Information System (INIS)

Weeks, J.R.; Czajkowski, C.J.; Tichler, P.R.

1988-01-01

The High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory (BNL) is an epithermal, externally moderated (by D 2 O) facility designed to produce neutron beams for research. Type 6061 T-6 aluminum was used for the beam tubes, pressure vessel, fuel cladding, and most other components in the high flux area. The HFBR has operated since 1965. The epithermal, external moderation of the HFBR means that materials irradiated in different areas of the facility receive widely different flux spectra. Thus, specimens from a control rod drive follower tube (CRDF) have received 1.5 /times/ 10 22 n/cm 2 (E > 0.1 MeV) and 3.2 /times/ 10 23 n/cm 2 thermal fluence, while those from a vertical thimble flow shroud received 1.9 /times/ 10 23 n/cm 2 (E > 0.1 MeV) and 1.0 /times/ 10 23 n/cm 2 thermal. These numbers correspond to fast to thermal fluence ratios ranging from 0.05 to 1.9. Irradiations are occurring at approximately 333/degree/K. The data indicate that the increase in tensile strength and decrease in ductility result primarily from the thermal fluence, i.e., the transmutation of aluminum to silicon. These effects appear to be saturating at fluences above approximately 1.8 /times/ 10 23 n/cm 2 thermal at values of 90,000 psi (6700 Kg/mm 2 ) and 9%, respectively. The specimens receiving the highest fluence ratios appear to have less increase in tensile strength and less decrease in ductility than specimens with a lower fast to thermal fluence ratio and the same thermal fluence, suggesting a possible beneficial effect of the high energy neutrons in preventing formation of silicon crystallites. 7 refs., 11 figs., 3 tabs

Effects of fasting and feeding on the fast-start swimming performance of southern catfish Silurus meridionalis.

Science.gov (United States)

Yan, G J; He, X K; Cao, Z D; Fu, S J

2015-01-21

This study investigated the effects of fasting and feeding on the fast-start escape swimming performance of juvenile southern catfish Silurus meridionalis, a sit-and-wait forager that encounters extreme fasting and famine frequently during its lifespan. Ten to 30 days of fasting resulted in no significant change in most of the variables measured in the fast-start response except a 20-30% decrease in the escape distance during the first 120 ms (D 120ms ) relative to the control group (48 h after feeding). The ratio of the single-bend (SB) response (lower energetic expenditure) to the double-bend (DB) response increased significantly from 0% in the control group to 75 and 82·5% in the 20 and 30 day fasting groups, respectively. Satiated feeding (25% of body mass) resulted in a significantly lower (36·6%) maximum linear velocity (V max ) and a significantly lower (43·3%) D 120ms than in non-fed fish (control group, 48 h after feeding). Half-satiated feeding (12·5% of body mass), however, showed no significant effects on any of the measured variables of the fast-start response relative to control fish. It is suggested that the increase in the ratio of SB:DB responses with fasting in S. meridionalis may reflect a trade-off between energy conservation and maintaining high V max , while variables of fast-start performance were more sensitive to feeding than fasting might be an adaptive strategy to their foraging mode and food availability in their habitat. © 2015 The Fisheries Society of the British Isles.

High-energy detector

Science.gov (United States)

Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

2011-11-22

The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

Energy Systems High-Pressure Test Laboratory | Energy Systems Integration

Science.gov (United States)

Facility | NREL Energy Systems High-Pressure Test Laboratory Energy Systems High-Pressure Test Laboratory In the Energy Systems Integration Facility's High-Pressure Test Laboratory, researchers can safely test high-pressure hydrogen components. Photo of researchers running an experiment with a hydrogen fuel

A fast mass spring model solver for high-resolution elastic objects

Science.gov (United States)

Zheng, Mianlun; Yuan, Zhiyong; Zhu, Weixu; Zhang, Guian

2017-03-01

Real-time simulation of elastic objects is of great importance for computer graphics and virtual reality applications. The fast mass spring model solver can achieve visually realistic simulation in an efficient way. Unfortunately, this method suffers from resolution limitations and lack of mechanical realism for a surface geometry model, which greatly restricts its application. To tackle these problems, in this paper we propose a fast mass spring model solver for high-resolution elastic objects. First, we project the complex surface geometry model into a set of uniform grid cells as cages through *cages mean value coordinate method to reflect its internal structure and mechanics properties. Then, we replace the original Cholesky decomposition method in the fast mass spring model solver with a conjugate gradient method, which can make the fast mass spring model solver more efficient for detailed surface geometry models. Finally, we propose a graphics processing unit accelerated parallel algorithm for the conjugate gradient method. Experimental results show that our method can realize efficient deformation simulation of 3D elastic objects with visual reality and physical fidelity, which has a great potential for applications in computer animation.

The fast breeder reactor

International Nuclear Information System (INIS)

Patterson, W.

1990-01-01

The author criticises the United Kingdom Atomic Energy Authority's fast breeder reactor programme in his evidence to the House of Commons Select Committee on Energy in January 1990. He argues for power generation by renewable means and greater efficiency in the use rather than in the generation of electricity. He refutes the arguments for nuclear power on the basis of reduced global warming as he claims support technology produces significant amounts of carbon dioxide in any case. Serious doubts are raised about the costs of a fast breeder reactor programme compared to, say, generation by pressurised water reactors. The idea of a uranium scarcity in several decades is also refuted. The reliability of fast breeder reactor technology is called into question. He argues against reprocessing plutonium for economic, health and safety reasons. (UK)

MCNPX simulations of fast neutron diagnostics for accelerator-driven systems

Energy Technology Data Exchange (ETDEWEB)

Habob, Moinul

2005-12-15

In accelerator-driven systems, the neutron spectrum will extend all the way up to the incident beam energy, i.e., several hundred MeV or even up to GeV energies. The high neutron energy allows novel diagnostics with a set of measurement techniques that can be used in a sub-critical reactor environment. Such measurements are primarily connected to system safety and validation. This report shows that in-core fast-neutron diagnostics can be employed to monitor changes in the position of incidence of the primary proton beam onto the neutron production target. It has also been shown that fast neutrons can be used to detect temperature-dependent density changes in a liquid lead-bismuth target. Fast neutrons can escape the system via the beam pipe for the incident proton beam. Out-of-core monitoring of these so called back-streaming neutrons could potentially be used to monitor beam changes if the target has a suitable shape. Moreover, diagnostics of back-streaming neutrons might be used for validation of the system design.

MCNPX simulations of fast neutron diagnostics for accelerator-driven systems

International Nuclear Information System (INIS)

Habib, Moinul

2005-12-01

In accelerator-driven systems, the neutron spectrum will extend all the way up to the incident beam energy, i.e., several hundred MeV or even up to GeV energies. The high neutron energy allows novel diagnostics with a set of measurement techniques that can be used in a sub-critical reactor environment. Such measurements are primarily connected to system safety and validation. This report shows that in-core fast-neutron diagnostics can be employed to monitor changes in the position of incidence of the primary proton beam onto the neutron production target. It has also been shown that fast neutrons can be used to detect temperature-dependent density changes in a liquid lead-bismuth target. Fast neutrons can escape the system via the beam pipe for the incident proton beam. Out-of-core monitoring of these so called back-streaming neutrons could potentially be used to monitor beam changes if the target has a suitable shape. Moreover, diagnostics of back-streaming neutrons might be used for validation of the system design

High temperature fast reactor for hydrogen production in Brazil; Reator nuclear rapido de altissima temperatura para producao de hidrogenio no Brasil

Energy Technology Data Exchange (ETDEWEB)

Nascimento, Jamil A. do; Ono, Shizuca; Guimaraes, Lamartine N.F. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados]. E-mail: jamil@ieav.cta.br

2008-07-01

The main nuclear reactors technology for the Generation IV, on development phase for utilization after 2030, is the fast reactor type with high temperature output to improve the efficiency of the thermo-electric conversion process and to enable applications of the generated heat in industrial process. Currently, water electrolysis and thermo chemical cycles using very high temperature are studied for large scale and long-term hydrogen production, in the future. With the possible oil scarcity and price rise, and the global warming, this application can play an important role in the changes of the world energy matrix. In this context, it is proposed a fast reactor with very high output temperature, {approx} 1000 deg C. This reactor will have a closed fuel cycle; it will be cooled by lead and loaded with nitride fuel. This reactor may be used for hydrogen, heat and electricity production in Brazil. It is discussed a development strategy of the necessary technologies and some important problems are commented. The proposed concept presents characteristics that meet the requirements of the Generation IV reactor class. (author)

A prospective audit of preprocedural fasting practices on a transplant ward: when fasting becomes starving.

Science.gov (United States)

Vidot, Helen; Teevan, Kate; Carey, Sharon; Strasser, Simone; Shackel, Nicholas

2016-03-01

To investigate the prevalence and duration of preprocedural medically ordered fasting during a period of hospitalisation in an Australian population of patients with hepatic cirrhosis or following liver transplantation and to identify potential solutions to reduce fasting times. Protein-energy malnutrition is a common finding in patients with hepatic cirrhosis and can impact significantly on survival and quality of life. Protein and energy requirements in patients with cirrhosis are higher than those of healthy individuals. A significant feature of cirrhosis is the induction of starvation metabolism following seven to eight hours of food deprivation. Many investigative and interventional procedures for patients with cirrhosis necessitate a period of fasting to comply with anaesthesia guidelines. An observational study of the fasting episodes for 34 hospitalised patients with hepatic cirrhosis or following liver transplantation. Nutritional status was estimated using subjective global assessment and handgrip strength. The prevalence and duration of fasting practices for diagnostic or investigational procedures were estimated using electronic records and patient notes. Thirty-three patients (97%) were malnourished. Twenty-two patients (65%) were fasted during the observation period. There were 43 occasions of fasting with a median fasting time of 13·5 hours. On 40 occasions fasting times exceeded the maximum six-hour guideline recommended prior to the administration of anaesthesia by the majority of Anaesthesiology Societies. The majority of procedures (77%) requiring fasting occurred after midday. Eating breakfast on the day of the procedure reduced fasting time by 45%. Medically ordered preprocedural fasting times almost always exceed existing guidelines in this nutritionally compromised group. Adherence to fasting guidelines and eating breakfast before the procedure can reduce fasting times significantly and avoid the potential induction of starvation metabolism

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

Collisions of highly stripped ions at MeV energies in gas targets: charge transfer and ionization

International Nuclear Information System (INIS)

Schlachter, A.S.

1980-01-01

Cross sections have been measured for charge transfer and ionization in H 2 and rare-gas targets by fast, highly ionized carbon, iron, niobium, and lead ions in charge states +3 to +59, with energies in the range 0.1 to 4.8 MeV/amu. Experimental results are compared with classical-trajectory calculations; agreement is generally good. For a given target, the cross sections for net ionization reduce to a common curve when plotted as cross section divided by charge state versus energy per nucleon divided by charge state

Very fast optical flaring from a possible new Galactic magnetar.

Science.gov (United States)

Stefanescu, A; Kanbach, G; Słowikowska, A; Greiner, J; McBreen, S; Sala, G

2008-09-25

Highly luminous rapid flares are characteristic of processes around compact objects like white dwarfs, neutron stars and black holes. In the high-energy regime of X-rays and gamma-rays, outbursts with variabilities on timescales of seconds or less are routinely observed, for example in gamma-ray bursts or soft gamma-ray repeaters. At optical wavelengths, flaring activity on such timescales has not been observed, other than from the prompt phase of one exceptional gamma-ray burst. This is mostly due to the fact that outbursts with strong, fast flaring are usually discovered in the high-energy regime; most optical follow-up observations of such transients use instruments with integration times exceeding tens of seconds, which are therefore unable to resolve fast variability. Here we show the observation of extremely bright and rapid optical flaring in the Galactic transient SWIFT J195509.6+261406. Our optical light curves are phenomenologically similar to high-energy light curves of soft gamma-ray repeaters and anomalous X-ray pulsars, which are thought to be neutron stars with extremely high magnetic fields (magnetars). This suggests that similar processes are in operation, but with strong emission in the optical, unlike in the case of other known magnetars.

Dose levels due to neutrons in the vicinity of high energy medical accelerators

International Nuclear Information System (INIS)

McGinley, P.H.; Wood, M.; Sohrabi, M.; Mills, M.; Rodriguez, R.

1976-01-01

High energy photons are generated for use in radiation therapy by the decelleration of electrons in metal targets. Fast neutrons are also generated as a result of (γ, n) and (e, e'n) interactions in the target, beam compensator filter, and collimator material. In this work the adsorbed dose to neutrons was measured at the center of a 10 x 10 cm photon beam and 5 cm outside of the beam edge for a number of treatment units. Dose levels due to slow and fast neutrons were also established outside of the treatment rooms and a Bonner sphere neutron spectrometer system was employed to determine the neutron energy spectrum due to stray neutron radiation at each accelerator. For the linac it was found that the neutron dose at the beam center was 0.0039% of the photon dose and values of 0.049% and 0.053% were observed for the Allis Chalmers betatron and the Brown Boveri Betatron. Dose equivalent rates in the range of 0.3 to 22.5 mrem/hr were measured for points outside the treatment rooms when the accelerators were operated at a photon dose rate of 100 rad/min at the treatment position

Experimental study of fast electron transport in dense plasmas

International Nuclear Information System (INIS)

Vaisseau, Xavier

2014-01-01

The framework of this PhD thesis is the inertial confinement fusion for energy production, in the context of the electron fast ignition scheme. The work consists in a characterization of the transport mechanisms of fast electrons, driven by intense laser pulses (10 19 - 10 20 W/cm 2 ) in both cold-solid and warm-dense matter. The first goal was to study the propagation of a fast electron beam, characterized by a current density ≥ 10 11 A/cm 2 , in aluminum targets initially heated close to the Fermi temperature by a counter-propagative planar shock. The planar compression geometry allowed us to discriminate the energy losses due to the resistive mechanisms from collisional ones by comparing solid and compressed targets of the same initial areal densities. We observed for the first time a significant increase of resistive energy losses in heated aluminum samples. The confrontation of the experimental data with the simulations, including a complete characterization of the electron source, of the target compression and of the fast electron transport, allowed us to study the time-evolution of the material resistivity. The estimated resistive electron stopping power in a warm-compressed target is of the same order as the collisional one. We studied the transport of the fast electrons generated in the interaction of a high-contrast laser pulse with a hollow copper cone, buried into a carbon layer, compressed by a counter-propagative planar shock. A X-ray imaging system allowed us to visualize the coupling of the laser pulse with the cone at different moments of the compression. This diagnostic, giving access to the fast electron spatial distribution, showed a fast electron generation in the entire volume of the cone for late times of compression, after shock breakout from the inner cone tip. For earlier times, the interaction at a high-contrast ensured that the source was contained within the cone tip, and the fast electron beam was collimated into the target depth by

SSTAR: The US lead-cooled fast reactor (LFR)

International Nuclear Information System (INIS)

Smith, Craig F.; Halsey, William G.; Brown, Neil W.; Sienicki, James J.; Moisseytsev, Anton; Wade, David C.

2008-01-01

It is widely recognized that the developing world is the next area for major energy demand growth, including demand for new and advanced nuclear energy systems. With limited existing industrial and grid infrastructures, there will be an important need for future nuclear energy systems that can provide small or moderate increments of electric power (10-700 MWe) on small or immature grids in developing nations. Most recently, the global nuclear energy partnership (GNEP) has identified, as one of its key objectives, the development and demonstration of concepts for small and medium-sized reactors (SMRs) that can be globally deployed while assuring a high level of proliferation resistance. Lead-cooled systems offer several key advantages in meeting these goals. The small lead-cooled fast reactor concept known as the small secure transportable autonomous reactor (SSTAR) has been under ongoing development as part of the US advanced nuclear energy systems programs. It is a system designed to provide energy security to developing nations while incorporating features to achieve nonproliferation goals, anticipating GNEP objectives. This paper presents the motivation for development of internationally deployable nuclear energy systems as well as a summary of one such system, SSTAR, which is the US Generation IV lead-cooled fast reactor system

Assessment of the use of vanadium redox flow batteries for energy storage and fast charging of electric vehicles in gas stations

International Nuclear Information System (INIS)

Cunha, Álvaro; Brito, F.P.; Martins, Jorge; Rodrigues, Nuno; Monteiro, Vitor; Afonso, João L.; Ferreira, Paula

2016-01-01

A network of conveniently located fast charging stations is one of the possibilities to facilitate the adoption of Electric Vehicles (EVs). This paper assesses the use of fast charging stations for EVs in conjunction with VRFBs (Vanadium Redox Flow Batteries). These batteries are charged during low electricity demand periods and then supply electricity for the fast charging of EVs during day, thus implementing a power peak shaving process. Flow batteries have unique characteristics which make them especially attractive when compared with conventional batteries, such as their ability to decouple rated power from rated capacity, as well as their greater design flexibility and nearly unlimited life. Moreover, their liquid nature allows their installation inside deactivated underground gas tanks located at gas stations, enabling a smooth transition of gas stations' business model towards the emerging electric mobility paradigm. A project of a VRFB system to fast charge EVs taking advantage of existing gas stations infrastructures is presented. An energy and cost analysis of this concept is performed, which shows that, for the conditions tested, the project is technologically and economically viable, although being highly sensitive to the investment costs and to the electricity market conditions. - Highlights: • Assessment of Vanadium Redox Flow Battery use for EV fast charge in gas stations. • This novel system proposal allows power peak shaving and use of deactivated gas tanks. • Philosophy allows seamless business transition towards the Electric Mobility paradigm. • Project is technologically and economically viable, although with long payback times. • Future Cost cuts due to technology maturation will consolidate project attractiveness.

Meso-optical Fourier transform microscope - a new device for high energy physics

International Nuclear Information System (INIS)

Astakhov, A.Ya.; Batusov, Yu.A.; Bencze, G.L.; Farago, I.; Kisvaradi, A.; Molnar, L.; Soroko, L.M.; Vegh, J.

1989-01-01

A new device for high energy physics, the Meso-optical Fourier Transform Microscope (MFTM), designed for observation fo straight line particle tracks in nuclear research emulsion is described. The MFTM works without any mechanical or electronical depth scanning and can be considered as a selectivity viewing 'eye'. The computer controlled system containing MFTM as its main unit is given. This system can be used for a fast search for particle tracks and events produced by high energy neutrinos from particle accelerators. The results of the first experimental test of the computer controlled MFTM are presented. The performance of this system is described and discussed. It is shown that the angular resolution of the MFTM is 1 angular minute and the measurement time is equal to 30 ms per image. As all operations in the MFTM proceed without any depth scanning, this new evaluation system works at least two orders of magnitude faster than any known system with a traditional optical microscope. (orig.)

Study on fast ion loss in HL-2A tokamak

International Nuclear Information System (INIS)

Liu Yi; Sun Tengfei; Ji Xiaoquan

2012-01-01

Experiments with a high-energy deuterium neutral beam (NB) injection (30 keV, about 0.6 MW) were performed on the HL-2A tokamak. Analysis of neutron decay following the NB 'blip' injection indicates that tangentially injected beam ions are well confined, slowing down classically in the HL-2A. Anomalous losses of beam ions were observed when a beta-induced Alfven acoustic (BAAE) mode was present in the plasma. Such a high energetic particle driven mode led to fast-ion loss, showing a strong influence of the energetic particle driven mode on the fast-ion transport. (authors)

Development of a fast voltage control method for electrostatic accelerators

International Nuclear Information System (INIS)

Lobanov, Nikolai R.; Linardakis, Peter; Tsifakis, Dimitrios

2014-01-01

The concept of a novel fast voltage control loop for tandem electrostatic accelerators is described. This control loop utilises high-frequency components of the ion beam current intercepted by the image slits to generate a correction voltage that is applied to the first few gaps of the low- and high-energy acceleration tubes adjoining the high voltage terminal. New techniques for the direct measurement of the transfer function of an ultra-high impedance structure, such as an electrostatic accelerator, have been developed. For the first time, the transfer function for the fast feedback loop has been measured directly. Slow voltage variations are stabilised with common corona control loop and the relationship between transfer functions for the slow and new fast control loops required for optimum operation is discussed. The main source of terminal voltage instabilities, which are due to variation of the charging current caused by mechanical oscillations of charging chains, has been analysed

The future of the Fast Breeder

International Nuclear Information System (INIS)

Lefevre, J.C.

1990-01-01

Fast Breeder Reactors (FBRs) can produce more fissile nuclei than they consume whilst, at the same time, generating energy using fast neutrons. By conversion of uranium isotope 238 into a fissionable fuel, FBRs provide over 60 times more energy than can be extracted from the uranium reserves by thermal reactors. Their development is therefore an essential objective in the next century, particularly for those industrialised countries that have little or no energy resources of their own. The European countries which have been engaged in the development of FBRs for more than 25 years have decided to collaborate in an advanced design, the European Fast Reactor (EFR) which uses the best of previous national projects and draws on extensive operating experience from FBR plants in Europe. The naturally safe characteristics and technological features of sodium-cooled Fast Reactors will be fully utilised in an EFR design which meets the same safety level as the Light Water Reactors (LWRs). Owing to technical progress and series construction effect, the EFR is expected to achieve competitiveness with contemporary LWRs with the higher capital cost of the Fast Reactor offset by its markedly lower fuel cycle cost. (author)

Pseudocapacitive Oxides and Sulfides for High-Performance Electrochemical Energy Storage

KAUST Repository

Xia, Chuan

2018-03-22

atypically layered systems can greatly lower the interaction energy and Li+ diffusion barrier, and it can completely suppress the crystal transformation during the charge-discharge process. As a result, we have successfully enabled the kinetically sluggish step to proceed at room temperature. We show that even at charge-discharge rates as fast as 100C (36 s), these 2D electrodes still offer a high capacity of 140 mAh g-1 due to the rapid Li+ ion diffusion in these 2D sheets. These results discussed in this part conclusively show that the ultrathin 2D geometry of atypically layered or non-layered materials could lead to significantly enhanced pseudocapacitive performance.

Follow-up of high energy neutrinos detected by the ANTARES telescope

Directory of Open Access Journals (Sweden)

Mathieu Aurore

2016-01-01

Full Text Available The ANTARES telescope is well-suited to detect high energy neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky with a high duty cycle. Potential neutrino sources are gamma-ray bursts, core-collapse supernovae and flaring active galactic nuclei. To enhance the sensitivity of ANTARES to such sources, a detection method based on follow-up observations from the neutrino direction has been developed. This program, denoted as TAToO, includes a network of robotic optical telescopes (TAROT, Zadko and MASTER and the Swift-XRT telescope, which are triggered when an “interesting” neutrino is detected by ANTARES. A follow-up of special events, such as neutrino doublets in time/space coincidence or a single neutrino having a very high energy or in the specific direction of a local galaxy, significantly improves the perspective for the detection of transient sources. The analysis of early and long term follow-up observations to search for fast and slowly varying transient sources, respectively, has been performed and the results covering optical and X-ray data are presented in this contribution.

Using the automata processor for fast pattern recognition in high energy physics experiments—A proof of concept

Energy Technology Data Exchange (ETDEWEB)

Wang, Michael H.L.S., E-mail: mwang@fnal.gov [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Cancelo, Gustavo; Green, Christopher [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Guo, Deyuan; Wang, Ke [University of Virginia, Charlottesville, VA 22904 (United States); Zmuda, Ted [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

2016-10-01

We explore the Micron Automata Processor (AP) as a suitable commodity technology that can address the growing computational needs of pattern recognition in High Energy Physics (HEP) experiments. A toy detector model is developed for which an electron track confirmation trigger based on the Micron AP serves as a test case. Although primarily meant for high speed text-based searches, we demonstrate a proof of concept for the use of the Micron AP in a HEP trigger application.

Fast Breeder Reactor studies

International Nuclear Information System (INIS)

Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

1980-07-01

This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

Fast Breeder Reactor studies

Energy Technology Data Exchange (ETDEWEB)

Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

1980-07-01

This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

Assessment of the thorium and uranium fuel cycle in the fast breeder and the high temperature reactor

International Nuclear Information System (INIS)

Schikorr, W.M.

1977-01-01

This report assesses the fissile fuel economy of the uranium and thorium cycle in the advanced reactors currently under development, the fast breeder reactor (FBR) and the high temperature reactor (HTR). It is shown by means of detailed burnup calculations that replacing UO 2 with ThO 2 or Th-metal as the radial blanket breeding material will not have any significant imapct on the breeding and burnup properties of the FBR. A global, analytical investigation is performed to study the fissile fuel economy of the many fissile fuel cycles possible in the HTR. Here it is demonstrated that the optimum conversion ratio of CR 3 O 8 ) demands are evaluated for a country such as the FRG under the assumptions of different future reactor strategy scenarios. Here it is demonstrated that the employement of both HTRs and FBRs can lead to a practically resource independent energy supply system within the next 40 to 60 years. However only through the large scale employement of the fast breeder can the future nuclear resource requirements be assured. (orig.) [de

Fast Spectrum Reactors

CERN Document Server

Todd, Donald; Tsvetkov, Pavel

2012-01-01

Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

High energy physics advisory panel's subpanel on vision for the future of high-energy physics

International Nuclear Information System (INIS)

1994-05-01

This report was requested by the Secretary of Energy to (1) define a long-term program for pursuing the most important high-energy physics goals since the termination of the Superconducting Super Collider (SSC) project, (2) assess the current US high-energy physics program, and (3) make recommendations regarding the future of the field. Subjects on which recommendations were sought and which the report addresses were: high-energy physics funding priorities; facilitating international collaboration for future construction of large high-energy physics facilities; optimizing uses of the investment made in the SSC; how to encourage displaced scientists and engineers to remain in high-energy physics and to attract young scientists to enter the field in the future. The report includes a description of the state of high-energy physics research in the context of history, a summary of the SSC project, and documentation of the report's own origins and development

The high current, fast, 100ns, Linear Transformer Driver (LTD) developmental project at Sandia National Laboratories

International Nuclear Information System (INIS)

Ward, Kevin S.; Long, Finis W.; Sinebryukhov, Vadim A.; Kim, Alexandre A.; Wakeland, Peter Eric; McKee, G. Randall; Woodworth, Joseph Ray; McDaniel, Dillon Heirman; Fowler, William E.; Mazarakis, Michael Gerrassimos; Porter, John Larry Jr.; Struve, Kenneth William; Stygar, William A.; LeChien, Keith R.; Matzen, Maurice Keith

2010-01-01

Sandia National Laboratories, Albuquerque, N.M., USA, in collaboration with the High Current Electronic Institute (HCEI), Tomsk, Russia, is developing a new paradigm in pulsed power technology: the Linear Transformer Driver (LTD) technology. This technological approach can provide very compact devices that can deliver very fast high current and high voltage pulses straight out of the cavity with out any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The load may be a vacuum electron diode, a z-pinch wire array, a gas puff, a liner, an isentropic compression load (ICE) to study material behavior under very high magnetic fields, or a fusion energy (IFE) target. This is because the output pulse rise time and width can be easily tailored to the specific application needs. In this paper we briefly summarize the developmental work done in Sandia and HCEI during the last few years, and describe our new MYKONOS Sandia High Current LTD Laboratory.

Time-resolved energy spectrum of a pseudospark-produced high-brightness electron beam

International Nuclear Information System (INIS)

Myers, T.J.; Ding, B.N.; Rhee, M.J.

1992-01-01

The pseudospark, a fast low-pressure gas discharge between a hollow cathode and a planar anode, is found to be an interesting high-brightness electron beam source. Typically, all electron beam produced in the pseudospark has the peak current of ∼1 kA, pulse duration of ∼50 ns, and effective emittance of ∼100 mm-mrad. The energy information of this electron beam, however, is least understood due to the difficulty of measuring a high-current-density beam that is partially space-charge neutralized by the background ions produced in the gas. In this paper, an experimental study of the time-resolved energy spectrum is presented. The pseudospark produced electron beam is injected into a vacuum through a small pinhole so that the electrons without background ions follow single particle motion; the beam is sent through a negative biased electrode and the only portion of beam whose energy is greater than the bias voltage can pass through the electrode and the current is measured by a Faraday cup. The Faraday cup signals with various bias voltage are recorded in a digital oscilloscope. The recorded waveforms are then numerically analyzed to construct a time-resolved energy spectrum. Preliminary results are presented