Global Sourcing, Technology, and Factor Intensity: Firm-level Relationships

OpenAIRE

TOMIURA Eiichi

2007-01-01

This paper empirically examines how technology and capital intensity are related with the firm's global sourcing decision. Firm-level data are derived from a survey covering all manufacturing industries in Japan without any firm-size threshold. Firms are disaggregated by their make-or-buy decision (in-house or outsourcing) and by their choice of sourcing location (offshore or domestic). Capital-intensive or R&D-intensive firms tend to source in-house from their FDI affiliates rather than outs...

Nanoscale shift of the intensity distribution of dipole radiation.

Science.gov (United States)

Shu, Jie; Li, Xin; Arnoldus, Henk F

2009-02-01

The energy flow lines (field lines of the Poynting vector) for radiation emitted by a dipole are in general curves, rather than straight lines. For a linear dipole the field lines are straight, but when the dipole moment of a source rotates, the field lines wind numerous times around an axis, which is perpendicular to the plane of rotation, before asymptotically approaching a straight line. We consider an elliptical dipole moment, representing the most general state of oscillation, and this includes the linear dipole as a special case. Due to the spiraling near the source, for the case of a rotating dipole moment, the field lines in the far field are displaced with respect to the outward radial direction, and this leads to a shift of the intensity distribution of the radiation in the far field. This shift is shown to be independent of the distance to the source and, although of nanoscale dimension, should be experimentally observable.

Intensity and absorbed-power distribution in a cylindrical solar-pumped dye laser

Science.gov (United States)

Williams, M. D.

1984-01-01

The internal intensity and absorbed-power distribution of a simplified hypothetical dye laser of cylindrical geometry is calculated. Total absorbed power is also calculated and compared with laboratory measurements of lasing-threshold energy deposition in a dye cell to determine the suitability of solar radiation as a pump source or, alternatively, what modifications, if any, are necessary to the hypothetical system for solar pumping.

Informal workshop on intense polarized ion sources: a summary

International Nuclear Information System (INIS)

Schultz, P.F.

1980-01-01

An Informal Workshop on Intense Polarized Ion Sources was held on March 6, 1980, at the O'Hare Hilton Hotel, Chicago, Illinois. The purpose of the Workshop was to discuss problems in developing higher-intensity polarized proton sources, particularly the optically-pumped source recently proposed by L.W. Anderson of the University of Wisconsin. A summary of the discussions is reported

Ion source and injection line for high intensity medical cyclotron

Science.gov (United States)

Jia, XianLu; Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

2014-02-01

A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 μA/14 MeV was extracted from the cyclotron with a small multi-cusp H- ion source (CIAE-CH-I type) and a short injection line, which the H- ion source of 3 mA/25 keV H- beam with emittance of 0.3π mm mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 μA was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper.

Performance of the intense pulsed neutron source accelerator system

International Nuclear Information System (INIS)

Potts, C.; Brumwell, F.; Rauchas, A.; Stipp, V.; Volk, G.

1983-01-01

The Intense Pulsed Neutron Source (IPNS) facility has now been operating in a routine way for outside users since November 1, 1981. From that date through December of 1982, the accelerator system was scheduled for neutron science for 4500 hours. During this time the accelerator achieved its short-term goals by delivering about 380,000,000 pulses of beam totaling over 6 x 10 20 protons. The changes in equipment and operating practices that evolved during this period of intense running are described. The intensity related instability threshold was increased by a factor of two and the accelerator beam current has been ion source limited. Plans to increase the accelerator intensity are also described. Initial operating results with a new H - ion source are discussed

High intensity neutrino source superconducting solenoid cyrostat design

Energy Technology Data Exchange (ETDEWEB)

Page, T.M.; Nicol, T.H.; Feher, S.; Terechkine, I.; Tompkins, J.; /Fermilab

2006-06-01

Fermi National Accelerator Laboratory (FNAL) is involved in the development of a 100 MeV superconducting linac. This linac is part of the High Intensity Neutrino Source (HINS) R&D Program. The initial beam acceleration in the front end section of the linac is achieved using room temperature spoke cavities, each of which is combined with a superconducting focusing solenoid. These solenoid magnets are cooled with liquid helium at 4.5K, operate at 250 A and have a maximum magnetic field strength of 7.5 T. The solenoid cryostat will house the helium vessel, suspension system, thermal shield, multilayer insulation, power leads, instrumentation, a vacuum vessel and cryogenic distribution lines. This paper discusses the requirements and detailed design of these superconducting solenoid cryostats.

Distribution Channel Intensity among Table Water Producers in Nigeria

Directory of Open Access Journals (Sweden)

Joseph Edewor Agbadudu

2017-09-01

Full Text Available Planning for and making reasonable decisions regarding reaching the target market with an organization’s product is a critical task on the part of management, which involves a careful evaluation and selection of its channel structure and intensity.This study therefore examines distribution channel intensity among table water producers in Edo State, Nigeria. The focus of the study is to ascertain the variables that significantly predict distribution intensity among the firms in the table water industry in Edo State. The study seeks to proffer answer to fundamental question of why brands within a single category of a given consumer good differ significantly in their distribution intensity. Using a survey research design, the data used for this study were obtained by taking a sample of 110 table water firms within the three senatorial districts in the State. The data obtained were presented and analyzed using different statistical tools such as mean and multiple regression through Statistical Packages for Social Sciences (SPSS version 22 software. Findings revealed that manufacturers’ target focus, manufacturers’ support program, brand quality and level of firm’s technological advancement were significant predictors of distribution channel intensity among the industrial players in table water industry in the State. Based on the findings, the study recommended that table water firms within the State can secure a competitive edge over their fellow counterpart in the industry by designing an optimal distribution intensity that will meet up their marketing objectives. It is also recommended that the adoption of modern technology in form of online sales is an efficient way of sales and distribution which could be used to enhance their distribution techniques if there is a need to cut down on middle men due to increased cost. The study concluded that optimal distribution intensity could be achieved not by mere imitation of competitors but through

Power Law Distributions in the Experiment for Adjustment of the Ion Source of the NBI System

International Nuclear Information System (INIS)

Han Xiaopu; Hu Chundong

2005-01-01

The experiential adjustment process in an experiment on the ion source of the neutral beam injector system for the HT-7 Tokamak is reported in this paper. With regard to the data obtained in the same condition, in arranging the arc current intensities of every shot with a decay rank, the distributions of the arc current intensity correspond to the power laws, and the distribution obtained in the condition with the cryo-pump corresponds to the double Pareto distribution. Using the similar study method, the distributions of the arc duration are close to the power laws too. These power law distributions are formed rather naturally instead of being the results of purposeful seeking

Intensity-Modulated Advanced X-ray Source (IMAXS) for Homeland Security Applications

International Nuclear Information System (INIS)

Langeveld, Willem G. J.; Johnson, William A.; Owen, Roger D.; Schonberg, Russell G.

2009-01-01

X-ray cargo inspection systems for the detection and verification of threats and contraband require high x-ray energy and high x-ray intensity to penetrate dense cargo. On the other hand, low intensity is desirable to minimize the radiation footprint. A collaboration between HESCO/PTSE Inc., Schonberg Research Corporation and Rapiscan Laboratories, Inc. has been formed in order to design and build an Intensity-Modulated Advanced X-ray Source (IMAXS). Such a source would allow cargo inspection systems to achieve up to two inches greater imaging penetration capability, while retaining the same average radiation footprint as present fixed-intensity sources. Alternatively, the same penetration capability can be obtained as with conventional sources with a reduction of the average radiation footprint by about a factor of three. The key idea is to change the intensity of the source for each x-ray pulse based on the signal strengths in the inspection system detector array during the previous pulse. In this paper we describe methods to accomplish pulse-to-pulse intensity modulation in both S-band (2998 MHz) and X-band (9303 MHz) linac sources, with diode or triode (gridded) electron guns. The feasibility of these methods has been demonstrated. Additionally, we describe a study of a shielding design that would allow a 6 MV X-band source to be used in mobile applications.

Over-Distribution in Source Memory

Science.gov (United States)

Brainerd, C. J.; Reyna, V. F.; Holliday, R. E.; Nakamura, K.

2012-01-01

Semantic false memories are confounded with a second type of error, over-distribution, in which items are attributed to contradictory episodic states. Over-distribution errors have proved to be more common than false memories when the two are disentangled. We investigated whether over-distribution is prevalent in another classic false memory paradigm: source monitoring. It is. Conventional false memory responses (source misattributions) were predominantly over-distribution errors, but unlike semantic false memory, over-distribution also accounted for more than half of true memory responses (correct source attributions). Experimental control of over-distribution was achieved via a series of manipulations that affected either recollection of contextual details or item memory (concreteness, frequency, list-order, number of presentation contexts, and individual differences in verbatim memory). A theoretical model was used to analyze the data (conjoint process dissociation) that predicts that predicts that (a) over-distribution is directly proportional to item memory but inversely proportional to recollection and (b) item memory is not a necessary precondition for recollection of contextual details. The results were consistent with both predictions. PMID:21942494

Calculating computer-generated optical elements to produce arbitrary intensity distributions

International Nuclear Information System (INIS)

Findlay, S.; Nugent, K.A.; Scholten, R.E.

2000-01-01

Full text: We describe preliminary investigation into using a computer to generate optical elements (CGOEs) with phase-only variation, that will produce an arbitrary intensity distribution in a given image plane. An iterative calculation cycles between the CGOE and the image plane and modifies each according to the appropriate constraints. We extend this to the calculation of defined intensity distributions in two separated planes by modifying both phase and intensity at the CGOE

High Intensity High Charge State ECR Ion Sources

CERN Document Server

Leitner, Daniela

2005-01-01

The next-generation heavy ion beam accelerators such as the proposed Rare Isotope Accelerator (RIA), the Radioactive Ion Beam Factory at RIKEN, the GSI upgrade project, the LHC-upgrade, and IMP in Lanzhou require a great variety of high charge state ion beams with a magnitude higher beam intensity than currently achievable. High performance Electron Cyclotron Resonance (ECR) ion sources can provide the flexibility since they can routinely produce beams from hydrogen to uranium. Over the last three decades, ECR ion sources have continued improving the available ion beam intensities by increasing the magnetic fields and ECR heating frequencies to enhance the confinement and the plasma density. With advances in superconducting magnet technology, a new generation of high field superconducting sources is now emerging, designed to meet the requirements of these next generation accelerator projects. The talk will briefly review the field of high performance ECR ion sources and the latest developments for high intens...

Intensity correlation imaging with sunlight-like source

Science.gov (United States)

Wang, Wentao; Tang, Zhiguo; Zheng, Huaibin; Chen, Hui; Yuan, Yuan; Liu, Jinbin; Liu, Yanyan; Xu, Zhuo

2018-05-01

We show a method of intensity correlation imaging of targets illuminated by a sunlight-like source both theoretically and experimentally. With a Faraday anomalous dispersion optical filter (FADOF), we have modulated the coherence time of a thermal source up to 0.167 ns. And we carried out measurements of temporal and spatial correlations, respectively, with an intensity interferometer setup. By skillfully using the even Fourier fitting on the very sparse sampling data, the images of targets are successfully reconstructed from the low signal-noise-ratio(SNR) interference pattern by applying an iterative phase retrieval algorithm. The resulting imaging quality is as well as the one obtained by the theoretical fitting. The realization of such a case will bring this technique closer to geostationary satellite imaging illuminated by sunlight.

Spectral intensity distribution of trapped fermions

Indian Academy of Sciences (India)

Trapped fermions; local density approximation; spectral intensity distribution function. ... Thus, cold atomic systems allow us to study interesting ... In fermions, synthetic non-Abelian gauge ... energy eigenstates of the isotropic harmonic oscillator [26–28]. ... d i=1. (ni + 1. 2. )ω0. In calculating the SIDF exactly these eigenfunc-.

Precipitation intensity probability distribution modelling for hydrological and construction design purposes

International Nuclear Information System (INIS)

Koshinchanov, Georgy; Dimitrov, Dobri

2008-01-01

The characteristics of rainfall intensity are important for many purposes, including design of sewage and drainage systems, tuning flood warning procedures, etc. Those estimates are usually statistical estimates of the intensity of precipitation realized for certain period of time (e.g. 5, 10 min., etc) with different return period (e.g. 20, 100 years, etc). The traditional approach in evaluating the mentioned precipitation intensities is to process the pluviometer's records and fit probability distribution to samples of intensities valid for certain locations ore regions. Those estimates further become part of the state regulations to be used for various economic activities. Two problems occur using the mentioned approach: 1. Due to various factors the climate conditions are changed and the precipitation intensity estimates need regular update; 2. As far as the extremes of the probability distribution are of particular importance for the practice, the methodology of the distribution fitting needs specific attention to those parts of the distribution. The aim of this paper is to make review of the existing methodologies for processing the intensive rainfalls and to refresh some of the statistical estimates for the studied areas. The methodologies used in Bulgaria for analyzing the intensive rainfalls and produce relevant statistical estimates: - The method of the maximum intensity, used in the National Institute of Meteorology and Hydrology to process and decode the pluviometer's records, followed by distribution fitting for each precipitation duration period; - As the above, but with separate modeling of probability distribution for the middle and high probability quantiles. - Method is similar to the first one, but with a threshold of 0,36 mm/min of intensity; - Another method proposed by the Russian hydrologist G. A. Aleksiev for regionalization of estimates over some territory, improved and adapted by S. Gerasimov for Bulgaria; - Next method is considering only

Ca-48 handling for a cyclotron ECR ion source to produce highly intense ion beams

International Nuclear Information System (INIS)

Lebedev, V.Ya.; Bogomolov, S.L.; Dmitriev, S.N.; Kutner, V.B.; Shamanin, A.N.; Yakushev, A.B.

2002-01-01

Production of highly intense ion beams of 48 Ca is one of the main tasks in experiments carried out within the framework of the synthesis of new superheavy elements. 48 Ca is very rare and expensive isotope, therefore there is necessity to reach the high intensity of ion beams of the isotope at a low consumption rate. Analysis and our preliminary experiments have showed that the best way of producing highly intense calcium ion beams is evaporation of metallic calcium in an ECR ion source. So we have developed a technique of metallic 48 Ca production by reducing CaO (this chemical form is available at the market with 40-80% of 48 Ca ) with aluminium powder. We used two tantalum crucibles: a larger, with a mixture of CaO + Al heated up to 1250 deg C, which was connected to the smaller (2 mm I.D. and 30 mm long) in which calcium vapour condensed. The temperature distribution in the small crucible was about 50 deg C at the bottom and about 500 deg C in the middle of the crucible. The pressure inside of the set-up was between 0.1 and 1 Pa. The production rate of metallic 48 Ca was 10-20 mg/h. The crucible with the condensed metallic Ca in argon atmosphere was transferred to the ECR-4M ion source, where it was inserted in a wired tubular oven and the calcium evaporation was controlled through the oven power supply. The application of metallic 48 Ca as the working substance for the ECR-4M ion source of the U-400 cyclotron of allowed us to approach a stable high intensity of 48 Ca ion beams: the intensities for the internal and external beams were 10 13 c -1 and 3.10 12 c -1 , respectively, at a consumption rate about 0.4 mg/h. A technique was developed for the reclamation of 48 Ca from the residue inside of the large crucible and from the inner parts of the ECR ion source. Extracting Ca from the inner parts of the ion source enabled us to save up to some 25% of the calcium used in the ECR ion source, so that the actual consumption rate was about 0.3 mg/h at the highest 48

Proton and Ion Sources for High Intensity Accelerators

CERN Multimedia

Scrivens, R

2004-01-01

Future high intensity ion accelerators, including the Spallation Neutron Source (SNS), the European Spallation Source (ESS), the Superconducting Proton Linac (SPL) etc, will require high current and high duty factor sources for protons and negative hydrogen ions. In order to achieve these goals, a comparison of the Electron Cyclotron Resonance, radio-frequency and Penning ion sources, among others, will be made. For each of these source types, the present operational sources will be compared to the state-of-the-art research devices with special attention given to reliability and availability. Finally, the future research and development aims will be discussed.

Multi-keV X-ray area source intensity at SGII laser facility

Science.gov (United States)

Wang, Rui-rong; An, Hong-hai; Xie, Zhi-yong; Wang, Wei

2018-05-01

Experiments for investigating the feasibility of multi-keV backlighters for several different metallic foil targets were performed at the Shenguang II (SGII) laser facility in China. Emission spectra in the energy range of 1.65-7.0 keV were measured with an elliptically bent crystal spectrometer, and the X-ray source size was measured with a pinhole camera. The X-ray intensity near 4.75 keV and the X-ray source size for titanium targets at different laser intensity irradiances were studied. By adjusting the total laser energy at a fixed focal spot size, laser intensity in the range of 1.5-5.0 × 1015 W/cm2, was achieved. The results show that the line emission intensity near 4.75 keV and the X-ray source size are dependent on the laser intensity and increase as the laser intensity increases. However, an observed "peak" in the X-ray intensity near 4.75 keV occurs at an irradiance of 4.0 × 1015 W/cm2. For the employed experimental conditions, it was confirmed that the laser intensity could play a significant role in the development of an efficient multi-keV X-ray source. The experimental results for titanium indicate that the production of a large (˜350 μm in diameter) intense backlighter source of multi-keV X-rays is feasible at the SGII facility.

Analysis of distribution of PSL intensity recorded in imaging plate

International Nuclear Information System (INIS)

Oda, Keiji; Tsukahara, Kazutaka; Tada, Hidenori; Yamauchi, Tomoya

2006-01-01

Supplementary experiments and theoretical consideration have been performed about a new method for particle identification with an imaging plate, which was proposed in the previous paper. The imaging plate was exposed to 137 Cs γ-rays, 2 MeV- protons accelerated by a tandem Van de Graaff, X-rays emitted from a tube operated under the condition of 20-70 kV, as well as α- and β-rays. The frequency distribution in PSL intensity in a pixel of 100μm x 100μm was measured and the standard deviation was obtained by fitting to a Gaussian. It was confirmed that the relative standard deviation decreased with the average PSL intensity for every radiation species and that the curves were roughly divided into four groups of α-rays, protons, β-rays and photons. In the second step, these data were analyzed by plotting the square of the relative standard deviation against the average PSL intensity in full-log scale, where the relation should be expressed by a straight line with an slope of -1 provided that the deviation could be dominated only by statistical fluctuation. The data for α- and β-rays deviated from a straight line and approached to each saturated value as the average PSL intensity increased. This saturation was considered to be caused by inhomogeneity in the source intensity. It was also out that the value of interception on full-log plot would have important information about PSL reading efficiency, one of characteristic parameters of imaging plate. (author)

Future prospects for ECR ion sources with improved charge state distributions

International Nuclear Information System (INIS)

Alton, G.D.

1995-01-01

Despite the steady advance in the technology of the ECR ion source, present art forms have not yet reached their full potential in terms of charge state and intensity within a particular charge state, in part, because of the narrow band width. single-frequency microwave radiation used to heat the plasma electrons. This article identifies fundamentally important methods which may enhance the performances of ECR ion sources through the use of: (1) a tailored magnetic field configuration (spatial domain) in combination with single-frequency microwave radiation to create a large uniformly distributed ECR ''volume'' or (2) the use of broadband frequency domain techniques (variable-frequency, broad-band frequency, or multiple-discrete-frequency microwave radiation), derived from standard TWT technology, to transform the resonant plasma ''surfaces'' of traditional ECR ion sources into resonant plasma ''volume''. The creation of a large ECR plasma ''volume'' permits coupling of more power into the plasma, resulting in the heating of a much larger electron population to higher energies, thereby producing higher charge state ions and much higher intensities within a particular charge state than possible in present forms of' the source. The ECR ion source concepts described in this article offer exciting opportunities to significantly advance the-state-of-the-art of ECR technology and as a consequence, open new opportunities in fundamental and applied research and for a variety of industrial applications

LED intense headband light source for fingerprint analysis

Science.gov (United States)

Villa-Aleman, Eliel

2005-03-08

A portable, lightweight and high-intensity light source for detecting and analyzing fingerprints during field investigation. On-site field analysis requires long hours of mobile analysis. In one embodiment, the present invention comprises a plurality of light emitting diodes; a power source; and a personal attachment means; wherein the light emitting diodes are powered by the power source, and wherein the power source and the light emitting diodes are attached to the personal attachment means to produce a personal light source for on-site analysis of latent fingerprints. The present invention is available for other applications as well.

Intensive Versus Distributed Aphasia Therapy: A Nonrandomized, Parallel-Group, Dosage-Controlled Study.

Science.gov (United States)

Dignam, Jade; Copland, David; McKinnon, Eril; Burfein, Penni; O'Brien, Kate; Farrell, Anna; Rodriguez, Amy D

2015-08-01

Most studies comparing different levels of aphasia treatment intensity have not controlled the dosage of therapy provided. Consequently, the true effect of treatment intensity in aphasia rehabilitation remains unknown. Aphasia Language Impairment and Functioning Therapy is an intensive, comprehensive aphasia program. We investigated the efficacy of a dosage-controlled trial of Aphasia Language Impairment and Functioning Therapy, when delivered in an intensive versus distributed therapy schedule, on communication outcomes in participants with chronic aphasia. Thirty-four adults with chronic, poststroke aphasia were recruited to participate in an intensive (n=16; 16 hours per week; 3 weeks) versus distributed (n=18; 6 hours per week; 8 weeks) therapy program. Treatment included 48 hours of impairment, functional, computer, and group-based aphasia therapy. Distributed therapy resulted in significantly greater improvements on the Boston Naming Test when compared with intensive therapy immediately post therapy (P=0.04) and at 1-month follow-up (P=0.002). We found comparable gains on measures of participants' communicative effectiveness, communication confidence, and communication-related quality of life for the intensive and distributed treatment conditions at post-therapy and 1-month follow-up. Aphasia Language Impairment and Functioning Therapy resulted in superior clinical outcomes on measures of language impairment when delivered in a distributed versus intensive schedule. The therapy progam had a positive effect on participants' functional communication and communication-related quality of life, regardless of treatment intensity. These findings contribute to our understanding of the effect of treatment intensity in aphasia rehabilitation and have important clinical implications for service delivery models. © 2015 American Heart Association, Inc.

Fast optical source for quantum key distribution based on semiconductor optical amplifiers.

Science.gov (United States)

Jofre, M; Gardelein, A; Anzolin, G; Amaya, W; Capmany, J; Ursin, R; Peñate, L; Lopez, D; San Juan, J L; Carrasco, J A; Garcia, F; Torcal-Milla, F J; Sanchez-Brea, L M; Bernabeu, E; Perdigues, J M; Jennewein, T; Torres, J P; Mitchell, M W; Pruneri, V

2011-02-28

A novel integrated optical source capable of emitting faint pulses with different polarization states and with different intensity levels at 100 MHz has been developed. The source relies on a single laser diode followed by four semiconductor optical amplifiers and thin film polarizers, connected through a fiber network. The use of a single laser ensures high level of indistinguishability in time and spectrum of the pulses for the four different polarizations and three different levels of intensity. The applicability of the source is demonstrated in the lab through a free space quantum key distribution experiment which makes use of the decoy state BB84 protocol. We achieved a lower bound secure key rate of the order of 3.64 Mbps and a quantum bit error ratio as low as 1.14×10⁻² while the lower bound secure key rate became 187 bps for an equivalent attenuation of 35 dB. To our knowledge, this is the fastest polarization encoded QKD system which has been reported so far. The performance, reduced size, low power consumption and the fact that the components used can be space qualified make the source particularly suitable for secure satellite communication.

Design of an intense positron source for linear colliders

International Nuclear Information System (INIS)

Ida, H.; Yamada, K.; Funahashi, Y.

1994-01-01

The Japan Linear Collider (JLC) requires an intense positron source of 8x10 11 particles per rf-pulse. A computer simulation reveals the possibility of such an intense positron source using 'conventional' technology. In order to relax the limitation of the incident electron energy density due to thermal stress in the converter target, the incident beam radius is enlarged within the range so as not to reduce the positron capture efficiency. A pre-damping ring and beam transport system to the pre-damping ring, which have a large transverse acceptance, play important roles for a high capture efficiency. A prototype positron source has been designed and installed at downstream of 1.54 GeV S-band linac in Accelerator Test Facility (ATF) in order to carry out experiments to develop the essential technology for JLC. The simulated results will be tested in experiments with the prototype positron source. (author)

Income Disparities and the Global Distribution of Intensively Farmed Chicken and Pigs.

Directory of Open Access Journals (Sweden)

Marius Gilbert

Full Text Available The rapid transformation of the livestock sector in recent decades brought concerns on its impact on greenhouse gas emissions, disruptions to nitrogen and phosphorous cycles and on land use change, particularly deforestation for production of feed crops. Animal and human health are increasingly interlinked through emerging infectious diseases, zoonoses, and antimicrobial resistance. In many developing countries, the rapidity of change has also had social impacts with increased risk of marginalisation of smallholder farmers. However, both the impacts and benefits of livestock farming often differ between extensive (backyard farming mostly for home-consumption and intensive, commercial production systems (larger herd or flock size, higher investments in inputs, a tendency towards market-orientation. A density of 10,000 chickens per km2 has different environmental, epidemiological and societal implications if these birds are raised by 1,000 individual households or in a single industrial unit. Here, we introduce a novel relationship that links the national proportion of extensively raised animals to the gross domestic product (GDP per capita (in purchasing power parity. This relationship is modelled and used together with the global distribution of rural population to disaggregate existing 10 km resolution global maps of chicken and pig distributions into extensive and intensive systems. Our results highlight countries and regions where extensive and intensive chicken and pig production systems are most important. We discuss the sources of uncertainties, the modelling assumptions and ways in which this approach could be developed to forecast future trajectories of intensification.

Income Disparities and the Global Distribution of Intensively Farmed Chicken and Pigs.

Science.gov (United States)

Gilbert, Marius; Conchedda, Giulia; Van Boeckel, Thomas P; Cinardi, Giuseppina; Linard, Catherine; Nicolas, Gaëlle; Thanapongtharm, Weerapong; D'Aietti, Laura; Wint, William; Newman, Scott H; Robinson, Timothy P

2015-01-01

The rapid transformation of the livestock sector in recent decades brought concerns on its impact on greenhouse gas emissions, disruptions to nitrogen and phosphorous cycles and on land use change, particularly deforestation for production of feed crops. Animal and human health are increasingly interlinked through emerging infectious diseases, zoonoses, and antimicrobial resistance. In many developing countries, the rapidity of change has also had social impacts with increased risk of marginalisation of smallholder farmers. However, both the impacts and benefits of livestock farming often differ between extensive (backyard farming mostly for home-consumption) and intensive, commercial production systems (larger herd or flock size, higher investments in inputs, a tendency towards market-orientation). A density of 10,000 chickens per km2 has different environmental, epidemiological and societal implications if these birds are raised by 1,000 individual households or in a single industrial unit. Here, we introduce a novel relationship that links the national proportion of extensively raised animals to the gross domestic product (GDP) per capita (in purchasing power parity). This relationship is modelled and used together with the global distribution of rural population to disaggregate existing 10 km resolution global maps of chicken and pig distributions into extensive and intensive systems. Our results highlight countries and regions where extensive and intensive chicken and pig production systems are most important. We discuss the sources of uncertainties, the modelling assumptions and ways in which this approach could be developed to forecast future trajectories of intensification.

Income Disparities and the Global Distribution of Intensively Farmed Chicken and Pigs

Science.gov (United States)

Gilbert, Marius; Conchedda, Giulia; Van Boeckel, Thomas P.; Cinardi, Giuseppina; Linard, Catherine; Nicolas, Gaëlle; Thanapongtharm, Weerapong; D'Aietti, Laura; Wint, William; Newman, Scott H.; Robinson, Timothy P.

2015-01-01

The rapid transformation of the livestock sector in recent decades brought concerns on its impact on greenhouse gas emissions, disruptions to nitrogen and phosphorous cycles and on land use change, particularly deforestation for production of feed crops. Animal and human health are increasingly interlinked through emerging infectious diseases, zoonoses, and antimicrobial resistance. In many developing countries, the rapidity of change has also had social impacts with increased risk of marginalisation of smallholder farmers. However, both the impacts and benefits of livestock farming often differ between extensive (backyard farming mostly for home-consumption) and intensive, commercial production systems (larger herd or flock size, higher investments in inputs, a tendency towards market-orientation). A density of 10,000 chickens per km2 has different environmental, epidemiological and societal implications if these birds are raised by 1,000 individual households or in a single industrial unit. Here, we introduce a novel relationship that links the national proportion of extensively raised animals to the gross domestic product (GDP) per capita (in purchasing power parity). This relationship is modelled and used together with the global distribution of rural population to disaggregate existing 10 km resolution global maps of chicken and pig distributions into extensive and intensive systems. Our results highlight countries and regions where extensive and intensive chicken and pig production systems are most important. We discuss the sources of uncertainties, the modelling assumptions and ways in which this approach could be developed to forecast future trajectories of intensification. PMID:26230336

X-ray intensity and source size characterizations for the 25 kV upgraded Manson source at Sandia National Laboratories

Energy Technology Data Exchange (ETDEWEB)

Loisel, G., E-mail: gploise@sandia.gov; Lake, P.; Gard, P.; Dunham, G.; Nielsen-Weber, L.; Wu, M. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Norris, E. [Missouri University of Science and Technology, Rolla, Missouri 65409 (United States)

2016-11-15

At Sandia National Laboratories, the x-ray generator Manson source model 5 was upgraded from 10 to 25 kV. The purpose of the upgrade is to drive higher characteristics photon energies with higher throughput. In this work we present characterization studies for the source size and the x-ray intensity when varying the source voltage for a series of K-, L-, and M-shell lines emitted from Al, Y, and Au elements composing the anode. We used a 2-pinhole camera to measure the source size and an energy dispersive detector to monitor the spectral content and intensity of the x-ray source. As the voltage increases, the source size is significantly reduced and line intensity is increased for the three materials. We can take advantage of the smaller source size and higher source throughput to effectively calibrate the suite of Z Pulsed Power Facility crystal spectrometers.

X-ray intensity and source size characterizations for the 25 kV upgraded Manson source at Sandia National Laboratories.

Science.gov (United States)

Loisel, G; Lake, P; Gard, P; Dunham, G; Nielsen-Weber, L; Wu, M; Norris, E

2016-11-01

At Sandia National Laboratories, the x-ray generator Manson source model 5 was upgraded from 10 to 25 kV. The purpose of the upgrade is to drive higher characteristics photon energies with higher throughput. In this work we present characterization studies for the source size and the x-ray intensity when varying the source voltage for a series of K-, L-, and M-shell lines emitted from Al, Y, and Au elements composing the anode. We used a 2-pinhole camera to measure the source size and an energy dispersive detector to monitor the spectral content and intensity of the x-ray source. As the voltage increases, the source size is significantly reduced and line intensity is increased for the three materials. We can take advantage of the smaller source size and higher source throughput to effectively calibrate the suite of Z Pulsed Power Facility crystal spectrometers.

Security analysis of an untrusted source for quantum key distribution: passive approach

International Nuclear Information System (INIS)

Zhao Yi; Qi Bing; Lo, H-K; Qian Li

2010-01-01

We present a passive approach to the security analysis of quantum key distribution (QKD) with an untrusted source. A complete proof of its unconditional security is also presented. This scheme has significant advantages in real-life implementations as it does not require fast optical switching or a quantum random number generator. The essential idea is to use a beam splitter to split each input pulse. We show that we can characterize the source using a cross-estimate technique without active routing of each pulse. We have derived analytical expressions for the passive estimation scheme. Moreover, using simulations, we have considered four real-life imperfections: additional loss introduced by the 'plug and play' structure, inefficiency of the intensity monitor noise of the intensity monitor, and statistical fluctuation introduced by finite data size. Our simulation results show that the passive estimate of an untrusted source remains useful in practice, despite these four imperfections. Also, we have performed preliminary experiments, confirming the utility of our proposal in real-life applications. Our proposal makes it possible to implement the 'plug and play' QKD with the security guaranteed, while keeping the implementation practical.

A High-Intensity, RF Plasma-Sputter Negative Ion Source

International Nuclear Information System (INIS)

Alton, G.D.; Bao, Y.; Cui, B.; Lohwasser, R.; Reed, C.A.; Zhang, T.

1999-01-01

A high-intensity, plasma-sputter negative-ion source based on the use of RF power for plasma generation has been developed that can be operated in either pulsed or dc modes. The source utilizes a high-Q, self-igniting, inductively coupled antenna system, operating at 80 MHz that has been optimized to generate Cs-seeded plasmas at low pressures (typically, - (610 microA); F - (100 microA); Si - (500 microA); S - (500 microA); P - (125 microA); Cl - (200 microA); Ni - (150 microA); Cu - (230 microA); Ge - (125 microA); As - (100 microA); Se - (200 microA); Ag - (70 microA); Pt - (125 microA); Au - (250 microA). The normalized emittance var e psilon n of the source at the 80% contour is: var e psilon n = 7.5 mm.mrad.(MeV) 1/2 . The design principles of the source, operational parameters, ion optics, emittance and intensities for a number of negative-ion species will be presented in this report

An intense plane-beam ion source (1963); Source d'ions intense a faisceau plan (1963)

Energy Technology Data Exchange (ETDEWEB)

Deicas, R; Valckx, F P.O. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1963-07-01

Experiments are described carried out on the cross-section of a Penning type ion source which is a prototype of the annular ion source intended for the M.M.I.I. device at the Fontenay-aux-Roses Nuclear Research Centre. It is shown that the existence or absence of a very strong concentration depends in particular on the magnetic geometry. With a suitable magnetic and electrical geometry it is possible to concentrate the discharge towards the slit and thus to increase considerably the electrical yield and the gas yield. In pulsed conditions, the current derived from this source can exceed 100 mA with a slit 20 cm long and 0.2 mm wide. The gas yield can attain 20 per cent. The main characteristics of the discharge and of the beam are examined. (authors) [French] On decrit les experiences faites sur une section droite d'une source d'ions type Penning, qui est un prototype pour une source d'ions annulaire, destine au dispositif M.M.I.I. au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. On montre que l'existence ou non d'un regime intense depend surtout de la geometrie magnetique. Avec une geometrie magnetique et electrique convenables on peut concentrer la decharge vers les levres et ainsi augmenter considerablement le rendement electrique et le rendement en gaz. En regime pulse le courant extrait de cette source peut depasser 100 mA avec une fente de 20 cm de long et 0. 2 mm de largeur. Le rendement en gaz peut atteindre 20 pour cent. On etudie les principales caracteristiques de la decharge et du faisceau. (auteurs)

Acoustic Emission Source Location Using a Distributed Feedback Fiber Laser Rosette

Directory of Open Access Journals (Sweden)

Fang Li

2013-10-01

Full Text Available This paper proposes an approach for acoustic emission (AE source localization in a large marble stone using distributed feedback (DFB fiber lasers. The aim of this study is to detect damage in structures such as those found in civil applications. The directional sensitivity of DFB fiber laser is investigated by calculating location coefficient using a method of digital signal analysis. In this, autocorrelation is used to extract the location coefficient from the periodic AE signal and wavelet packet energy is calculated to get the location coefficient of a burst AE source. Normalization is processed to eliminate the influence of distance and intensity of AE source. Then a new location algorithm based on the location coefficient is presented and tested to determine the location of AE source using a Delta (Δ DFB fiber laser rosette configuration. The advantage of the proposed algorithm over the traditional methods based on fiber Bragg Grating (FBG include the capability of: having higher strain resolution for AE detection and taking into account two different types of AE source for location.

Intense neutron source: high-voltage power supply specifications

International Nuclear Information System (INIS)

Riedel, A.A.

1980-08-01

This report explains the need for and sets forth the electrical, mechanical and safety specifications for a high-voltage power supply to be used with the intense neutron source. It contains sufficient information for a supplier to bid on such a power supply

Disentangling the major source areas for an intense aerosol advection in the Central Mediterranean on the basis of Potential Source Contribution Function modeling of chemical and size distribution measurements

Science.gov (United States)

Petroselli, Chiara; Crocchianti, Stefano; Moroni, Beatrice; Castellini, Silvia; Selvaggi, Roberta; Nava, Silvia; Calzolai, Giulia; Lucarelli, Franco; Cappelletti, David

2018-05-01

In this paper, we combined a Potential Source Contribution Function (PSCF) analysis of daily chemical aerosol composition data with hourly aerosol size distributions with the aim to disentangle the major source areas during a complex and fast modulating advection event impacting on Central Italy in 2013. Chemical data include an ample set of metals obtained by Proton Induced X-ray Emission (PIXE), main soluble ions from ionic chromatography and elemental and organic carbon (EC, OC) obtained by thermo-optical measurements. Size distributions have been recorded with an optical particle counter for eight calibrated size classes in the 0.27-10 μm range. We demonstrated the usefulness of the approach by the positive identification of two very different source areas impacting during the transport event. In particular, biomass burning from Eastern Europe and desert dust from Sahara sources have been discriminated based on both chemistry and size distribution time evolution. Hourly BT provided the best results in comparison to 6 h or 24 h based calculations.

Design of intense neutron source for fusion material study and the role of universities

International Nuclear Information System (INIS)

Ishino, Shiori

1993-01-01

Need and requirement for the intense neutron source for fusion materials study have been discussed for many years. Recently, international climate has been becoming gradually maturing to consider this problem more seriously because of the recognition of crucial importance of solving materials problems for fusion energy development. The present symposium was designed to discuss the problems associated with the intense neutron source for material irradiation studies which will have a potential for the National Institute for Fusion Science to become one of the important future research areas. The symposium comprises five sessions; first, the role of materials research in fusion development strategies was discussed followed by a brief summary of current IFMIF (International Fusion Materials Irradiation Facility) activity. Despite the pressing need for intense fusion neutron source, currently available neutron sources are reactor or accelerator based sources of which FFTF and LASREF were discussed. Then, various concepts of intense neutron source candidates were presented including ESNIT, which are currently under design by JAERI. In the fourth session, discussions were made on the study of materials with the intense neutron source from the viewpoint of materials scientists and engineers as the user of the facility. This is followed by discussions on the role of universities from the two stand points, namely, fusion irradiation studies and fusion materials development. Finally summary discussions were made by the participants, indicating important role fundamental studies in universities for the full utilization of irradiation data and the need of pure 14 MeV neutron source for fundamental studies together with the intense surrogate neutron sources. (author)

Beam intensity increases at the intense pulsed neutron source accelerator

International Nuclear Information System (INIS)

Potts, C.; Brumwell, F.; Norem, J.; Rauchas, A.; Stipp, V.; Volk, G.

1985-01-01

The Intense Pulsed Neutron Source (IPNS) accelerator system has managed a 40% increase in time average beam current over the last two years. Currents of up to 15.6μA (3.25 x 10 12 protons at 30 Hz) have been successfully accelerated and cleanly extracted. Our high current operation demands low loss beam handling to permit hands-on maintenance. Synchrotron beam handling efficiencies of 90% are routine. A new H - ion source which was installed in March of 1983 offered the opportunity to get above 8 μA but an instability caused unacceptable losses when attempting to operate at 10 μA and above. Simple techniques to control the instabilities were introduced and have worked well. These techniques are discussed below. Other improvements in the regulation of various power supplies have provided greatly improved low energy orbit stability and contributed substantially to the increased beam current

Influence of temperature rise distribution in second harmonic generation crystal on intensity distributions of output second harmonic wave

International Nuclear Information System (INIS)

Li Wei; Feng Guoying; Li Gang; Huang Yu; Zhang Qiuhui

2009-01-01

Second-harmonic generation (SHG) of high-intensity laser with an SHG crystal for type I angle phase matching has been studied by the use of a split-step algorithm based on the fast Fourier transform and a fourth-order Runge-Kutta (R-K) integrator. The transverse walk-off effect, diffraction, the second-order and the third-order nonlinear effects have been taken into consideration. Influences of a temperature rise distribution of the SHG crystal on the refractive indices of ordinary wave and extraordinary wave have been discussed. The rules of phase mismatching quantity, intensity distribution of output beam and frequency conversion efficiency varying with the temperature rise distribution of the SHG crystal have been analyzed quantitatively. The calculated results indicate that in a high power frequency conversion system, the temperature rise distribution of SHG crystal would result in the phase mismatching of fundamental and harmonic waves, leading to the variation of intensity distribution of the output beam and the decrease of the conversion efficiency. (authors)

Measurement of intensity distribution of CSR in LEBRA PXR beamline

International Nuclear Information System (INIS)

Nakao, Keisuke; Sakai, Takeshi; Hayakawa, Ken; Tanaka, Toshinari; Hayakawa, Yasushi; Nogami, Kyoko; Inagaki, Manabu; Sei, Norihiro

2014-01-01

Last year, the intensity of Coherent Synchrotron Radiation (CSR) in LEBRA PXR beamline was measured. As a result, it turned out that the intensity of CSR was stronger than anticipation. It is suggested that Coherent Edge Radiation (CER) is mixed with CSR. Then, in order to confirm whether CER is contained, the intensity distribution of CSR was measured. The result of the experiment is reported in this paper. (author)

Calculation of neutron interior source distribution within subcritical fission-chain reacting systems for a prescribed power density generation

International Nuclear Information System (INIS)

Moraes, Leonardo R.C.; Alves Filho, Hermes; Barros, Ricardo C.

2017-01-01

Accelerator Driven Systems (ADS) are sub-critical systems stabilized by stationary external sources of neutrons. A system is subcritical when the removal by absorption and leakage exceeds the production by fission and tends to shut down. On the other hand, any subcritical system can be stabilized by including time-independent external sources of neutrons. The goal of this work is to determine the intensity of uniform and isotropic sources of neutrons that must be added inside all fuel regions of a subcritical system so that it becomes stabilized, generating a prescribed distribution of electric power. A computer program has been developed in Java language to estimate the intensity of stationary sources of neutrons that must be included in the fuel regions to drive the subcritical system with a fixed power distribution prescribed by the user. The mathematical model used to achieve this goal was the energy multigroup, slab-geometry neutron transport equation in the discrete ordinates (S N ) formulation and the response matrix method was applied to solve the forward and the adjoint S N problems. Numerical results are given to verify the present. (author)

Calculation of neutron interior source distribution within subcritical fission-chain reacting systems for a prescribed power density generation

Energy Technology Data Exchange (ETDEWEB)

Moraes, Leonardo R.C.; Alves Filho, Hermes; Barros, Ricardo C., E-mail: lrcmoraes@iprj.uerj.br, E-mail: halves@iprj.uerj.br, E-mail: ricardob@iprj.uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Programa de Pós-Graduação em Modelagem Computacional

2017-07-01

Accelerator Driven Systems (ADS) are sub-critical systems stabilized by stationary external sources of neutrons. A system is subcritical when the removal by absorption and leakage exceeds the production by fission and tends to shut down. On the other hand, any subcritical system can be stabilized by including time-independent external sources of neutrons. The goal of this work is to determine the intensity of uniform and isotropic sources of neutrons that must be added inside all fuel regions of a subcritical system so that it becomes stabilized, generating a prescribed distribution of electric power. A computer program has been developed in Java language to estimate the intensity of stationary sources of neutrons that must be included in the fuel regions to drive the subcritical system with a fixed power distribution prescribed by the user. The mathematical model used to achieve this goal was the energy multigroup, slab-geometry neutron transport equation in the discrete ordinates (S{sub N}) formulation and the response matrix method was applied to solve the forward and the adjoint S{sub N} problems. Numerical results are given to verify the present. (author)

Distributed source coding of video

DEFF Research Database (Denmark)

Forchhammer, Søren; Van Luong, Huynh

2015-01-01

A foundation for distributed source coding was established in the classic papers of Slepian-Wolf (SW) [1] and Wyner-Ziv (WZ) [2]. This has provided a starting point for work on Distributed Video Coding (DVC), which exploits the source statistics at the decoder side offering shifting processing...... steps, conventionally performed at the video encoder side, to the decoder side. Emerging applications such as wireless visual sensor networks and wireless video surveillance all require lightweight video encoding with high coding efficiency and error-resilience. The video data of DVC schemes differ from...... the assumptions of SW and WZ distributed coding, e.g. by being correlated in time and nonstationary. Improving the efficiency of DVC coding is challenging. This paper presents some selected techniques to address the DVC challenges. Focus is put on pin-pointing how the decoder steps are modified to provide...

Production, Distribution, and Applications of Californium-252 Neutron Sources

International Nuclear Information System (INIS)

Balo, P.A.; Knauer, J.B.; Martin, R.C.

1999-01-01

The radioisotope 252 Cf is routinely encapsulated into compact, portable, intense neutron sources with a 2.6-year half-life. A source the size of a person's little finger can emit up to 10 11 neutrons/s. Californium-252 is used commercially as a reliable, cost-effective neutron source for prompt gamma neutron activation analysis (PGNAA) of coal, cement, and minerals, as well as for detection and identification of explosives, laud mines, and unexploded military ordnance. Other uses are neutron radiography, nuclear waste assays, reactor start-up sources, calibration standards, and cancer therapy. The inherent safety of source encapsulations is demonstrated by 30 years of experience and by U.S. Bureau of Mines tests of source survivability during explosions. The production and distribution center for the U. S Department of Energy (DOE) Californium Program is the Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL). DOE sells 252 Cf to commercial reencapsulators domestically and internationally. Sealed 252 Cf sources are also available for loan to agencies and subcontractors of the U.S. government and to universities for educational, research, and medical applications. The REDC has established the Californium User Facility (CUF) for Neutron Science to make its large inventory of 252 Cf sources available to researchers for irradiations inside uncontaminated hot cells. Experiments at the CUF include a land mine detection system, neutron damage testing of solid-state detectors, irradiation of human cancer cells for boron neutron capture therapy experiments, and irradiation of rice to induce genetic mutations

Force distribution is more important than its intensity!

Directory of Open Access Journals (Sweden)

Alberto Consolaro

2014-01-01

Full Text Available A common question about root resorption is raised in orthodontic practice: What is more important, the intensity of force or its distribution along the root, periodontal and alveolar structures? Diffuse distribution of forces applied to periodontal tissues during tooth movement tends not to promote neither extensive areas of cell matrix hyalinization nor significant death of cementoblasts that lead to root resorption. However, focal distribution or concentration of forces within a restricted area - as it occurs in tipping movements, even with forces of lower intensity - tend to induce extensive areas of hyalinization and focal death of cementoblasts, which is commonly associated with root resorption. In tipping movements, the apical regions tend to concentrate more forces in addition to wounding the cementoblasts due to the smaller dimension of their root structure as well as their cone shape. For this reason, there is an increase in root resorption. In the cervical region, on the other hand, the large area resulting from a large diameter and bone crown deflection tends to reduce the effects of forces, even when they are more concentrated, thus rarely inducing death of cementoblasts and root resorption.

Multipurpose intense 14 MeV neutron source at Bratislava: Design study

International Nuclear Information System (INIS)

Pivarc, J.; Hlavac, S.; Kral, J.; Oblozinsky, P.; Ribansky, I.; Turzo, I.

1980-05-01

The present state of design of the multipurpose intense 14 MeV neutron source based on a D + ion beam and a metal tritide target is reported. It is essentially a 300 keV electrostatic air insulated accelerator capable to accelerate a deuterium ion beam up to 10 mA. With such a beam and a beam spot of 1 cm 2 , a neutron yield typically 10 12 n/s and a useful target lifetime of around 10 h are expected. Various users requirements are met by means of three beam lines: an intense, low current dc and a low current fast pulsed. The key components of the intense source section are the rotating target and the ion source. The rotating target is proposed, with respect of the heat dissipation and the removal of 3 kW/cm 2 , in continuous operation. A rotation speed up to 1100 rpm is considered. The ion source should deliver about 0.5 kW of extracted D + ion beam power. A duoplasmatron source with an electrostatic beam focusing system has been selected. Low current sections of the neutron source may operate with a high frequency ion source as well. The dc section for maximum yields around 10 10 n/s is designed with special regard to beam monitoring. The fast pulsed section should produce up to 1 ns compressible pulsed D + ion beam on a target spot with 5 MHz repetition rate. The report includes information about other components of the neutron source as a high voltage power supply, a vacuum system, beam transport, a diagnostic and control system and basic information about neutron source cells and radiation protection. (author)

Optimal distribution of integration time for intensity measurements in Stokes polarimetry.

Science.gov (United States)

Li, Xiaobo; Liu, Tiegen; Huang, Bingjing; Song, Zhanjie; Hu, Haofeng

2015-10-19

We consider the typical Stokes polarimetry system, which performs four intensity measurements to estimate a Stokes vector. We show that if the total integration time of intensity measurements is fixed, the variance of the Stokes vector estimator depends on the distribution of the integration time at four intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the Stokes vector estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time by employing Lagrange multiplier method. According to the theoretical analysis and real-world experiment, it is shown that the total variance of the Stokes vector estimator can be significantly decreased about 40% in the case discussed in this paper. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improves the measurement accuracy of the polarimetric system.

Jet target intense neutron source

International Nuclear Information System (INIS)

Meier, K.L.

1977-01-01

A jet target Intense Neutron Source (INS) is being built by the Los Alamos Scientific Laboratory with DOE/MFE funding in order to perform radiation damage experiments on materials to be used in fusion power reactors. The jet target can be either a supersonic or a subsonic jet. Each type has its particular advantages and disadvantages, and either of the jets can be placed inside the spherical blanket converter which will be used to simulate a fusion reactor neutron environment. Preliminary mock-up experiments with a 16-mA, 115 keV, H + ion beam on a nitrogen gas supersonic jet show no serious problems in the beam formation, transport, or jet interaction

Source distribution dependent scatter correction for PVI

International Nuclear Information System (INIS)

Barney, J.S.; Harrop, R.; Dykstra, C.J.

1993-01-01

Source distribution dependent scatter correction methods which incorporate different amounts of information about the source position and material distribution have been developed and tested. The techniques use image to projection integral transformation incorporating varying degrees of information on the distribution of scattering material, or convolution subtraction methods, with some information about the scattering material included in one of the convolution methods. To test the techniques, the authors apply them to data generated by Monte Carlo simulations which use geometric shapes or a voxelized density map to model the scattering material. Source position and material distribution have been found to have some effect on scatter correction. An image to projection method which incorporates a density map produces accurate scatter correction but is computationally expensive. Simpler methods, both image to projection and convolution, can also provide effective scatter correction

Polydisperse-particle-size-distribution function determined from intensity profile of angularly scattered light

International Nuclear Information System (INIS)

Alger, T.W.

1979-01-01

A new method for determining the particle-size-distribution function of a polydispersion of spherical particles is presented. The inversion technique for the particle-size-distribution function is based upon matching the measured intensity profile of angularly scattered light with a summation of the intensity contributions of a series of appropriately spaced, narrowband, size-distribution functions. A numerical optimization technique is used to determine the strengths of the individual bands that yield the best agreement with the measured scattered-light-intensity profile. Because Mie theory is used, the method is applicable to spherical particles of all sizes. Several numerical examples demonstrate the application of this inversion method

Image authentication using distributed source coding.

Science.gov (United States)

Lin, Yao-Chung; Varodayan, David; Girod, Bernd

2012-01-01

We present a novel approach using distributed source coding for image authentication. The key idea is to provide a Slepian-Wolf encoded quantized image projection as authentication data. This version can be correctly decoded with the help of an authentic image as side information. Distributed source coding provides the desired robustness against legitimate variations while detecting illegitimate modification. The decoder incorporating expectation maximization algorithms can authenticate images which have undergone contrast, brightness, and affine warping adjustments. Our authentication system also offers tampering localization by using the sum-product algorithm.

Quantitative x-ray absorption imaging with a broadband source: application to high-intensity discharge lamps

Energy Technology Data Exchange (ETDEWEB)

Curry, J J [National Institute of Standards and Technology, Gaithersburg, MD 20899-8422 (United States)], E-mail: jjcurry@nist.gov

2008-07-21

The case of x-ray absorption imaging in which the x-ray source is broadband and the detector does not provide spectral resolution is analysed. The specific motivation is observation of the Hg vapour distribution in high-intensity discharge (HID) lamps. When absorption by the vapour is small, the problem can be couched accurately in terms of a mean absorption cross section averaged over the x-ray spectral distribution, weighted by the energy-dependent response of the detector. The method is tested against a Au foil standard and then applied to Hg. The mean absorption cross section for Hg is calculated for a Ag-anode x-ray tube at accelerating voltages of 25, 30 and 35 kV, and for HIDs in fused silica or polycrystalline alumina arc tubes.

Shielding calculations for the Intense Neutron Source Facility. Final report

International Nuclear Information System (INIS)

Battat, M.E.; Henninger, R.J.; Macdonald, J.L.; Dudziak, D.J.

1978-06-01

Results of shielding calculations for the Intnse Neutron Source (INS) facility are presented. The INS facility is designed to house two sources, each of which will produce D--T neutrons with intensities in the range from 1 to 3 x 10 15 n/s on a continuous basis. Topics covered include the design of the biological shield, use of two-dimensional discrete-ordinates results to specify the source terms for a Monte Carlo skyshine calculation, air activation, and dose rates in the source cell (after shutdown) due to activation of the biological shield

High intensity line source for x-ray spectrometer calibration

International Nuclear Information System (INIS)

Thoe, R.S.

1986-06-01

A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 μ x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10 4 ) time-resolved cyrstal spectrometer, will be discussed in detail

Beam commission of the high intensity proton source developed at INFN-LNS for the European Spallation Source

Science.gov (United States)

Neri, L.; Celona, L.; Gammino, S.; Miraglia, A.; Leonardi, O.; Castro, G.; Torrisi, G.; Mascali, D.; Mazzaglia, M.; Allegra, L.; Amato, A.; Calabrese, G.; Caruso, A.; Chines, F.; Gallo, G.; Longhitano, A.; Manno, G.; Marletta, S.; Maugeri, A.; Passarello, S.; Pastore, G.; Seminara, A.; Spartà, A.; Vinciguerra, S.

2017-07-01

At the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS) the beam commissioning of the high intensity Proton Source for the European Spallation Source (PS-ESS) started in November 2016. Beam stability at high current intensity is one of the most important parameter for the first steps of the ongoing commissioning. Promising results were obtained since the first source start with a 6 mm diameter extraction hole. The increase of the extraction hole to 8 mm allowed improving PS-ESS performances and obtaining the values required by the ESS accelerator. In this work, extracted beam current characteristics together with Doppler shift and emittance measurements are presented, as well as the description of the next phases before the installation at ESS in Lund.

Neutrons Flux Distributions of the Pu-Be Source and its Simulation by the MCNP-4B Code

Science.gov (United States)

Faghihi, F.; Mehdizadeh, S.; Hadad, K.

Neutron Fluence rate of a low intense Pu-Be source is measured by Neutron Activation Analysis (NAA) of 197Au foils. Also, the neutron fluence rate distribution versus energy is calculated using the MCNP-4B code based on ENDF/B-V library. Theoretical simulation as well as our experimental performance are a new experience for Iranians to make reliability with the code for further researches. In our theoretical investigation, an isotropic Pu-Be source with cylindrical volume distribution is simulated and relative neutron fluence rate versus energy is calculated using MCNP-4B code. Variation of the fast and also thermal neutrons fluence rate, which are measured by NAA method and MCNP code, are compared.

The distribution of polarized radio sources >15 μJy IN GOODS-N

International Nuclear Information System (INIS)

Rudnick, L.; Owen, F. N.

2014-01-01

We present deep Very Large Array observations of the polarization of radio sources in the GOODS-N field at 1.4 GHz at resolutions of 1.''6 and 10''. At 1.''6, we find that the peak flux cumulative number count distribution is N(> p) ∼ 45*(p/30 μJy) –0.6 per square degree above a detection threshold of 14.5 μJy. This represents a break from the steeper slopes at higher flux densities, resulting in fewer sources predicted for future surveys with the Square Kilometer Array and its precursors. It provides a significant challenge for using background rotation measures (RMs) to study clusters of galaxies or individual galaxies. Most of the polarized sources are well above our detection limit, and they are also radio galaxies that are well-resolved even at 10'', with redshifts from ∼0.2-1.9. We determined a total polarized flux for each source by integrating the 10'' polarized intensity maps, as will be done by upcoming surveys such as POSSUM. These total polarized fluxes are a factor of two higher, on average, than the peak polarized flux at 1.''6; this would increase the number counts by ∼50% at a fixed flux level. The detected sources have RMs with a characteristic rms scatter of ∼11 rad m –2 around the local Galactic value, after eliminating likely outliers. The median fractional polarization from all total intensity sources does not continue the trend of increasing at lower flux densities, as seen for stronger sources. The changes in the polarization characteristics seen at these low fluxes likely represent the increasing dominance of star-forming galaxies.

Performance Characteristics Of An Intensity Modulated Advanced X-Ray Source (IMAXS) For Homeland Security Applications

International Nuclear Information System (INIS)

Langeveld, Willem G. J.; Brown, Craig; Condron, Cathie; Ingle, Mike; Christensen, Phil A.; Johnson, William A.; Owen, Roger D.; Hernandez, Michael; Schonberg, Russell G.; Ross, Randy

2011-01-01

X-ray cargo inspection systems for the detection and verification of threats and contraband must address stringent, competitive performance requirements. High x-ray intensity is needed to penetrate dense cargo, while low intensity is desirable to minimize the radiation footprint, i.e. the size of the controlled area, required shielding and the dose to personnel. In a collaborative effort between HESCO/PTSE Inc., XScell Corp., Stangenes Industries, Inc. and Rapiscan Laboratories, Inc., an Intensity Modulated Advanced X-ray Source (IMAXS) was designed and produced. Cargo inspection systems utilizing such a source have been projected to achieve up to 2 inches steel-equivalent greater penetration capability, while on average producing the same or smaller radiation footprint as present fixed-intensity sources. Alternatively, the design can be used to obtain the same penetration capability as with conventional sources, but reducing the radiation footprint by about a factor of three. The key idea is to anticipate the needed intensity for each x-ray pulse by evaluating signal strength in the cargo inspection system detector array for the previous pulse. The IMAXS is therefore capable of changing intensity from one pulse to the next by an electronic signal provided by electronics inside the cargo inspection system detector array, which determine the required source intensity for the next pulse. We report on the completion of a 9 MV S-band (2998 MHz) IMAXS source and comment on its performance.

Intense pulsed neutron source accelerator status

International Nuclear Information System (INIS)

Potts, C.W.; Brumwell, F.R.; Stipp, V.F.

1983-01-01

The Intense Pulsed Neutron Source (IPNS) facility has been in operation since November 1, 1981. From that date through August 1, 1983, the accelerator system was scheduled for 7191 hours of operation. During this period, 627 million pulses totaling about 1.1 x 10 21 protons were delivered to the spallation target. The accelerator has exceeded goals set in 1981 by averaging 8.65 μA over this two year period. This average beam current, while modest by the standards of proposed machines, makes the IPNS synchrotron (Rapid Cycling Synchrotron [RCS]) the highest intensity proton synchrotron in the world today. Detailed data on accelerator operation are presented. Weekly average currents of 12 μA have been achieved along with peaks of 13.9 μA. A great deal has been learned about the required operating constraints during high beam current operation. It should be possible to increase the average beam current during this next year to 12 μA while observing these restraints. Improvement plans have been formulated to increase the beam current to 16 μA over the next three years

Formation of a laser beam with a doughnut intensity distribution

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, I I; Troitskii, IU V; Iakushkin, S V

1986-02-01

The conditions of the simultaneous generation of TEM01 and TEM10 modes forming a beam with a doughnut intensity distribution are investigated. In the case of a complete suppression of the TEM00 mode, the ratio of the intensity at the crest of the ring to the intensity at the ring axis reaches 200 and is limited by dispersion in the optical elements of the resonator. Operation with mutual locking of TEM01 and TEM10 modes has been achieved which is characterized by complete spatial coherence of the ring-shaped beam.

Intense neutron source facility for the fusion energy program

International Nuclear Information System (INIS)

Armstrong, D.D.; Emigh, C.R.; Meier, K.L.; Meyer, E.A.; Schneider, J.D.

1975-01-01

The intense neutron source is based on the ability of a supersonic flow of gas to dissipate an enormous quantity of heat generated in the neutron-producing target by multiple Coulomb collisions. A description is given of the principles involved in forming the supersonic jet, in forming the intense tritium-ion beam, in the vacuum systems, and in the tritium handling systems. An overview of the entire facility is included. It is believed that the facility can be operated with high reliability, ensuring a productive radiation damage program. (U.S.)

Precise Mapping Of A Spatially Distributed Radioactive Source

International Nuclear Information System (INIS)

Beck, A.; Caras, I.; Piestum, S.; Sheli, E.; Melamud, Y.; Berant, S.; Kadmon, Y.; Tirosh, D.

1999-01-01

Spatial distribution measurement of radioactive sources is a routine task in the nuclear industry. The precision of each measurement depends upon the specific application. However, the technological edge of this precision is motivated by the production of standards for calibration. Within this definition, the most demanding field is the calibration of standards for medical equipment. In this paper, a semi-empirical method for controlling the measurement precision is demonstrated, using a relatively simple laboratory apparatus. The spatial distribution of the source radioactivity is measured as part of the quality assurance tests, during the production of flood sources. These sources are further used in calibration of medical gamma cameras. A typical flood source is a 40 x 60 cm 2 plate with an activity of 10 mCi (or more) of 57 Co isotope. The measurement set-up is based on a single NaI(Tl) scintillator with a photomultiplier tube, moving on an X Y table which scans the flood source. In this application the source is required to have a uniform activity distribution over its surface

Adaptive distributed source coding.

Science.gov (United States)

Varodayan, David; Lin, Yao-Chung; Girod, Bernd

2012-05-01

We consider distributed source coding in the presence of hidden variables that parameterize the statistical dependence among sources. We derive the Slepian-Wolf bound and devise coding algorithms for a block-candidate model of this problem. The encoder sends, in addition to syndrome bits, a portion of the source to the decoder uncoded as doping bits. The decoder uses the sum-product algorithm to simultaneously recover the source symbols and the hidden statistical dependence variables. We also develop novel techniques based on density evolution (DE) to analyze the coding algorithms. We experimentally confirm that our DE analysis closely approximates practical performance. This result allows us to efficiently optimize parameters of the algorithms. In particular, we show that the system performs close to the Slepian-Wolf bound when an appropriate doping rate is selected. We then apply our coding and analysis techniques to a reduced-reference video quality monitoring system and show a bit rate saving of about 75% compared with fixed-length coding.

Calibration of intense 60Co gamma ray sources at the Savannah River Plant

International Nuclear Information System (INIS)

Bibler, N.E.

1976-05-01

Three different dosimeters were used to calibrate Savannah River Plant 60 Co sources having intensities greater than 10 7 rads/hr. These dosimeters are (a) ceric sulfate dissolved in 0.4M H 2 SO 4 , (b) oxalic acid dissolved in water, and (c) a commercially available nylon film containing a radiochromic dye. Response per unit dose to these dosimeters is independent of radiation intensity at 10 4 to 10 11 rads/hr. The dosimeters were calibrated at 6.0 x 10 5 rads/hr with a 60 Co source whose intensity was determined with the standard Fricke dosimeter. For the sources at 10 7 rads/hr or greater, intensities were calculated from slopes of linear plots of dosimeter response versus irradiation time. Individual dose rates varied from 1.0 x 10 7 to 4.6 x 10 7 rads/hr. Each source was calibrated with at least two different dosimeters. Relative standard deviations varied from 2 to 9 percent. A conservative estimate of the uncertainty in the accuracy of these dosimeters is 10 percent. Of the three dosimeters, the nylon film is easiest to use and is therefore recommended for future calibrations

Galactic distribution of X-ray burst sources

International Nuclear Information System (INIS)

Lewin, W.H.G.; Hoffman, J.A.; Doty, J.; Clark, G.W.; Swank, J.H.; Becker, R.H.; Pravdo, S.H.; Serlemitsos, P.J.

1977-01-01

It is stated that 18 X-ray burst sources have been observed to date, applying the following definition for these bursts - rise times of less than a few seconds, durations of seconds to minutes, and recurrence in some regular pattern. If single burst events that meet the criteria of rise time and duration, but not recurrence are included, an additional seven sources can be added. A sky map is shown indicating their positions. The sources are spread along the galactic equator and cluster near low galactic longitudes, and their distribution is different from that of the observed globular clusters. Observations based on the SAS-3 X-ray observatory studies and the Goddard X-ray Spectroscopy Experiment on OSO-9 are described. The distribution of the sources is examined and the effect of uneven sky exposure on the observed distribution is evaluated. It has been suggested that the bursts are perhaps produced by remnants of disrupted globular clusters and specifically supermassive black holes. This would imply the existence of a new class of unknown objects, and at present is merely an ad hoc method of relating the burst sources to globular clusters. (U.K.)

ASPUN: design for an Argonne super-intense pulsed neutron source

International Nuclear Information System (INIS)

Khoe, T.K.; Kustom, R.L.

1983-01-01

Argonne pioneered the pulsed spallation neutron source with the ZING-P and IPNS-I concepts. IPNS-I is now a reliable and actively used source for pulsed spallation neutrons. The accelerator is a 500-MeV, 8 to 9 μa, 30-Hz rapid-cycling proton synchrotron. Other proton spallation sources are now in operation or in construction. These include KENS-I at the National Laboratory for High Energy Physics in Japan, the WNR/PSR at Los Alamos National Laboratory in the USA, and the SNS at the Rutherford Appleton Laboratory in England. Newer and bolder concepts are being developed for more-intense pulsed spallation neutron sources. These include SNQ at the KFA Laboratory in Juelich, Germany, ASTOR at the Swiss Institute for Nuclear Physics in Switzerland, and ASPUN, the Argonne concept. ASPUN is based on the Fixed-Field Alternating Gradient concept. The design goal is to provide a time-averaged beam of 3.5 ma at 1100 MeV on a spallation target in intense bursts, 100 to 200 nanoseconds long, at a repetition rate of no more than 60 to 85 Hz

Distributed power sources for Mars colonization

International Nuclear Information System (INIS)

Miley, George H.; Shaban, Yasser

2003-01-01

One of the fundamental needs for Mars colonization is an abundant source of energy. The total energy system will probably use a mixture of sources based on solar energy, fuel cells, and nuclear energy. Here we concentrate on the possibility of developing a distributed system employing several unique new types of nuclear energy sources, specifically small fusion devices using inertial electrostatic confinement and portable 'battery type' proton reaction cells

Distributed coding of multiview sparse sources with joint recovery

DEFF Research Database (Denmark)

Luong, Huynh Van; Deligiannis, Nikos; Forchhammer, Søren

2016-01-01

In support of applications involving multiview sources in distributed object recognition using lightweight cameras, we propose a new method for the distributed coding of sparse sources as visual descriptor histograms extracted from multiview images. The problem is challenging due to the computati...... transform (SIFT) descriptors extracted from multiview images shows that our method leads to bit-rate saving of up to 43% compared to the state-of-the-art distributed compressed sensing method with independent encoding of the sources....

Inverse identification of intensity distributions from multiple flux maps in concentrating solar applications

International Nuclear Information System (INIS)

Erickson, Ben; Petrasch, Jörg

2012-01-01

Radiative flux measurements at the focal plane of solar concentrators are typically performed using digital cameras in conjunction with Lambertian targets. To accurately predict flux distributions on arbitrary receiver geometries directional information about the radiation is required. Currently, the directional characteristics of solar concentrating systems are predicted via ray tracing simulations. No direct experimental technique to determine intensities of concentrating solar systems is available. In the current paper, multiple parallel flux measurements at varying distances from the focal plane together with a linear inverse method and Tikhonov regularization are used to identify the directional and spatial intensity distribution at the solution plane. The directional binning feature of an in-house Monte Carlo ray tracing program is used to provide a reference solution. The method has been successfully applied to two-dimensional concentrators, namely parabolic troughs and elliptical troughs using forward Monte Carlo ray tracing simulations that provide the flux maps as well as consistent, associated intensity distribution for validation. In the two-dimensional case, intensity distributions obtained from the inverse method approach the Monte Carlo forward solution. In contrast, the method has not been successful for three dimensional and circular symmetric concentrator geometries.

High-intensity, thin-target He-jet production source

International Nuclear Information System (INIS)

Bai, Y.; Vieira, D.J.; Wouters, J.M.; Butler, G.W.; Rosenauer, Dk; Loebner, K.E.G.; Lind, V.G.; Phillips, D.R.

1996-01-01

A thin-target He-jet system suited to the production and rapid transport of non-volatile radioactive species has been successfully operated with proton beam intensities of up to 700 μA. The system consists of a water-cooled, thin-target chamber, capillary gas transport system, moving tape/Ge detection system, and an aerosol generator/gas recirculator. The yields for a wide variety of uranium fission and deep spallation products have been measured and robust operation of the system demonstrated for several weeks. He-jet transport and collection efficiencies ranged between 15 and 25% with collection rates of 10 7 to 10 8 atoms/sec/isotope. The high-intensity, thin-target He-jet approach represents a robust production source for nonvolatile radioactive heavy ion beams

Activity distribution of a cobalt-60 teletherapy source

International Nuclear Information System (INIS)

Jaffray, D.A.; Munro, P.; Battista, J.J.; Fenster, A.

1991-01-01

In the course of quantifying the effect of radiation source size on the spatial resolution of portal images, a concentric ring structure in the activity distribution of a Cobalt-60 teletherapy source has been observed. The activity distribution was measured using a strip integral technique and confirmed independently by a contact radiograph of an identical but inactive source replica. These two techniques suggested that this concentric ring structure is due to the packing configuration of the small 60Co pellets that constitute the source. The source modulation transfer function (MTF) showed that this ring structure has a negligible influence on the spatial resolution of therapy images when compared to the effect of the large size of the 60Co source

Cosmic ray intensity distribution in the vertical direction to solar equator plane

International Nuclear Information System (INIS)

Nosaka, Toru; Mori, Satoru; Sagisaka, Shuji.

1983-01-01

The data of the annual variation of cosmic ray intensity measured by neutron detectors were used to study the distribution of cosmic ray intensity vertical to the solar equator plane and its long term variation. The data used were obtained at Deep River, Kiel, Kerguelen Island, McMurdo, Ottawa, and Mt. Washington. All data showed annual variation. The patterns and degree of variation obtained in northern and southern hemisphere were similar. The summation dial representation of the annual variation and semi-annual variation of cosmic ray was obtained. The inversion of annual variation in 1958 - 1959 and 1968 - 1969 corresponded to the inversion of polarity of solar pole magnetic field. The semi-annual variation showed a complex behavior. The helio-latitudial distribution of cosmic ray intensity was obtained. The asymmetric distribution in relation to the solar equator was observed in the annual variation. The northward gradient of density in 1955 - 1958 and southward gradient in 1959 - 1968 were seen. (Kato, T.)

MIT/OSO 7 catalog of x-ray sources: intensities, spectra, and long-term variability

International Nuclear Information System (INIS)

Markert, T.H.; Winkler, P.F.; Laird, F.N.; Clark, G.W.; Hearn, D.R.; Sprott, G.F.; Li, F.K.; Bradt, H.V.; Lewin, W.H.G.; Schnopper, H.W.

1979-01-01

This paper is a summary of the observations of the cosmic X-ray sky performed by the MIT 1--40 KeV X-ray detectors on the OSO 7 between 1971 October and 1973 May. Specifically, we have computed the mean intensities or upper limits of all third Uhuru or OSO 7 cataloged sources (185 sources) in the 3--10 KeV range. For those sources for which a statistically significant (>20) intensity was found in the 3--10 KeV band (138 sources), further intensity determinations were made in the 1--15 KeV, 1--6 KeV, and 15--40 KeV energy bands. We have provided graphs and other simple techniques to aid the user in converting the observed counting rates to convenient units and in determining spectral parameters. Finally, we have plotted long-term light curves (counting rates in one or more energy bands as a function of time) for 86 of the brighter sources

The Earth's mantle in a microwave oven: thermal convection driven by a heterogeneous distribution of heat sources

Science.gov (United States)

Fourel, Loïc; Limare, Angela; Jaupart, Claude; Surducan, Emanoil; Farnetani, Cinzia G.; Kaminski, Edouard C.; Neamtu, Camelia; Surducan, Vasile

2017-08-01

Convective motions in silicate planets are largely driven by internal heat sources and secular cooling. The exact amount and distribution of heat sources in the Earth are poorly constrained and the latter is likely to change with time due to mixing and to the deformation of boundaries that separate different reservoirs. To improve our understanding of planetary-scale convection in these conditions, we have designed a new laboratory setup allowing a large range of heat source distributions. We illustrate the potential of our new technique with a study of an initially stratified fluid involving two layers with different physical properties and internal heat production rates. A modified microwave oven is used to generate a uniform radiation propagating through the fluids. Experimental fluids are solutions of hydroxyethyl cellulose and salt in water, such that salt increases both the density and the volumetric heating rate. We determine temperature and composition fields in 3D with non-invasive techniques. Two fluorescent dyes are used to determine temperature. A Nd:YAG planar laser beam excites fluorescence, and an optical system, involving a beam splitter and a set of colour filters, captures the fluorescence intensity distribution on two separate spectral bands. The ratio between the two intensities provides an instantaneous determination of temperature with an uncertainty of 5% (typically 1K). We quantify mixing processes by precisely tracking the interfaces separating the two fluids. These novel techniques allow new insights on the generation, morphology and evolution of large-scale heterogeneities in the Earth's lower mantle.

Angular intensity of a gas-phase field ionization source

International Nuclear Information System (INIS)

Orloff, J.; Swanson, L.W.

1979-01-01

Angular intensities of 1 μA sr -1 have been measured for a gas-phase field ionization source in an optical column under practical operating conditions. The source, which was differentially pumped and cooled to 77 K, utilized a -oriented iridium emitter and precooled hydrogen gas at 10 -2 Torr. The ion beam was collimated with an electrostatic lens and detected below an aperture subtending 0.164 msr. A transmitted current of approx.10 -10 A was measured at voltages corresponding to a field of approx. =2.2 V/A at the emitter

Development of exploding wire ion source for intense pulsed heavy ion beam accelerator

International Nuclear Information System (INIS)

Ochiai, Y.; Murata, T.; Ito, H.; Masugata, K.

2012-01-01

A Novel exploding wire type ion source device is proposed as a metallic ion source of intense pulsed heavy ion beam (PHIB) accelerator. In the device multiple shot operations is realized without breaking the vacuum. The basic characteristics of the device are evaluated experimentally with an aluminum wire of diameter 0.2 mm, length 25 mm. Capacitor bank of capacitance 3 μF, charging voltage 30 kV was used and the wire was successfully exploded by a discharge current of 15 kA, rise time 5.3 μs. Plasma flux of ion current density around 70 A/cm 2 was obtained at 150 mm downstream from the device. The drift velocity of ions evaluated by a time-of-flight method was 2.7x10 4 m/sec, which corresponds to the kinetic energy of 100 eV for aluminum ions. From the measurement of ion current density distribution ion flow is found to be concentrated to the direction where ion acceleration gap is placed. From the experiment the device is found to be acceptable for applying PHIB accelerator. (author)

Microseism Source Distribution Observed from Ireland

Science.gov (United States)

Craig, David; Bean, Chris; Donne, Sarah; Le Pape, Florian; Möllhoff, Martin

2017-04-01

Ocean generated microseisms (OGM) are recorded globally with similar spectral features observed everywhere. The generation mechanism for OGM and their subsequent propagation to continental regions has led to their use as a proxy for sea-state characteristics. Also many modern seismological methods make use of OGM signals. For example, the Earth's crust and upper mantle can be imaged using ``ambient noise tomography``. For many of these methods an understanding of the source distribution is necessary to properly interpret the results. OGM recorded on near coastal seismometers are known to be related to the local ocean wavefield. However, contributions from more distant sources may also be present. This is significant for studies attempting to use OGM as a proxy for sea-state characteristics such as significant wave height. Ireland has a highly energetic ocean wave climate and is close to one of the major source regions for OGM. This provides an ideal location to study an OGM source region in detail. Here we present the source distribution observed from seismic arrays in Ireland. The region is shown to consist of several individual source areas. These source areas show some frequency dependence and generally occur at or near the continental shelf edge. We also show some preliminary results from an off-shore OBS network to the North-West of Ireland. The OBS network includes instruments on either side of the shelf and should help interpret the array observations.

Light and Light Sources High-Intensity Discharge Lamps

CERN Document Server

Flesch, Peter G

2006-01-01

Light and Light Sources gives an introduction to the working principles of high-intensity discharge (HID) lamps and points out challenges and problems associated with the development and operation of HID lamps. The state-of-the-art in electrode and plasma diagnostics as well as numerical methods used for the understanding of HID lamps are described. This volume addresses students as well as scientists and researchers at universities and in industry.

REPORT OF THE SNOWMASS M6 WORKING GROUP ON HIGH INTENSITY PROTON SOURCES.

Energy Technology Data Exchange (ETDEWEB)

CHOU,W.; WEI,J.

2001-08-14

The M6 working group had more than 40 active participants (listed in Section 4). During the three weeks at Snowmass, there were about 50 presentations, covering a wide range of topics associated with high intensity proton sources. The talks are listed in Section 5. This group also had joint sessions with a number of other working groups, including E1 (Neutrino Factories and Muon Colliders), E5 (Fixed-Target Experiments), M1 (Muon Based Systems), T4 (Particle Sources), T5 (Beam dynamics), T7 (High Performance Computing) and T9 (Diagnostics). The M6 group performed a survey of the beam parameters of existing and proposed high intensity proton sources, in particular, of the proton drivers. The results are listed in Table 1. These parameters are compared with the requirements of high-energy physics users of secondary beams in Working Groups E1 and E5. According to the consensus reached in the E1 and E5 groups, the U.S. HEP program requires an intense proton source, a 1-4 MW Proton Driver, by the end of this decade.

REPORT OF THE SNOWMASS M6 WORKING GROUP ON HIGH INTENSITY PROTON SOURCES

International Nuclear Information System (INIS)

CHOU, W.; WEI, J.

2001-01-01

The M6 working group had more than 40 active participants (listed in Section 4). During the three weeks at Snowmass, there were about 50 presentations, covering a wide range of topics associated with high intensity proton sources. The talks are listed in Section 5. This group also had joint sessions with a number of other working groups, including E1 (Neutrino Factories and Muon Colliders), E5 (Fixed-Target Experiments), M1 (Muon Based Systems), T4 (Particle Sources), T5 (Beam dynamics), T7 (High Performance Computing) and T9 (Diagnostics). The M6 group performed a survey of the beam parameters of existing and proposed high intensity proton sources, in particular, of the proton drivers. The results are listed in Table 1. These parameters are compared with the requirements of high-energy physics users of secondary beams in Working Groups E1 and E5. According to the consensus reached in the E1 and E5 groups, the U.S. HEP program requires an intense proton source, a 1-4 MW Proton Driver, by the end of this decade

The Los Alamos Intense Neutron Source

International Nuclear Information System (INIS)

Nebel, R.A.; Barnes, D.C.; Bollman, R.; Eden, G.; Morrison, L.; Pickrell, M.M.; Reass, W.

1997-01-01

The Intense Neutron Source (INS) is an Inertial Electrostatic Confinement (IEC) fusion device presently under construction at Los Alamos National Laboratory. It is designed to produce 10 11 neutrons per second steady-state using D-T fuel. Phase 1 operation of this device will be as a standard three grid IEC ion focus device. Expected performance has been predicted by scaling from a previous IEC device. Phase 2 operation of this device will utilize a new operating scheme, the Periodically Oscillating Plasma Sphere (POPS). This scheme is related to both the Spherical Reflect Diode and the Oscillating Penning Trap. With this type of operation the authors hope to improve plasma neutron production to about 10 13 neutrons/second

Computer program for source distribution process in radiation facility

International Nuclear Information System (INIS)

Al-Kassiri, H.; Abdul Ghani, B.

2007-08-01

Computer simulation for dose distribution using Visual Basic has been done according to the arrangement and activities of Co-60 sources. This program provides dose distribution in treated products depending on the product density and desired dose. The program is useful for optimization of sources distribution during loading process. there is good agreement between calculated data for the program and experimental data.(Author)

The dose distribution surrounding 192Ir and 137Cs seed sources

International Nuclear Information System (INIS)

Thomason, C.; Mackie, T.R.; Wisconsin Univ., Madison, WI; Lindstrom, M.J.; Higgins, P.D.

1991-01-01

Dose distributions in water were measured using LiF thermoluminescent dosemeters for 192 Ir seed sources with stainless steel and with platinum encapsulation to determine the effect of differing encapsulation. Dose distribution was measured for a 137 Cs seed source. In addition, dose distributions surrounding these sources were calculated using the EGS4 Monte Carlo code and were compared to measured data. The two methods are in good agreement for all three sources. Tables are given describing dose distribution surrounding each source as a function of distance and angle. Specific dose constants were also determined from results of Monte Carlo simulation. This work confirms the use of the EGS4 Monte Carlo code in modelling 192 Ir and 137 Cs seed sources to obtain brachytherapy dose distributions. (author)

A Heuristic Approach to Distributed Generation Source Allocation for Electrical Power Distribution Systems

Directory of Open Access Journals (Sweden)

M. Sharma

2010-12-01

Full Text Available The recent trends in electrical power distribution system operation and management are aimed at improving system conditions in order to render good service to the customer. The reforms in distribution sector have given major scope for employment of distributed generation (DG resources which will boost the system performance. This paper proposes a heuristic technique for allocation of distribution generation source in a distribution system. The allocation is determined based on overall improvement in network performance parameters like reduction in system losses, improvement in voltage stability, improvement in voltage profile. The proposed Network Performance Enhancement Index (NPEI along with the heuristic rules facilitate determination of feasible location and corresponding capacity of DG source. The developed approach is tested with different test systems to ascertain its effectiveness.

Transfrontier macroseismic data exchange in NW Europe: examples of non-circular intensity distributions

Science.gov (United States)

Van Noten, Koen; Lecocq, Thomas; Hinzen, Klaus-G.; Sira, Christophe; Camelbeeck, Thierry

2016-04-01

Macroseismic data acquisition recently received a strong increase in interest due to public crowdsourcing through internet-based inquiries and real-time smartphone applications. Macroseismic analysis of felt earthquakes is important as the perception of people can be used to detect local/regional site effects in areas without instrumentation. We will demonstrate how post-processing macroseismic data improves the quality of real-time intensity evaluation of new events. Instead of using the classic DYFI representation in which internet intensities are averaged per community, we, first, geocoded all individual responses and structure the model area into 100 km2grid cells. Second, the average intensity of all answers within a grid cell is calculated. The resulting macroseismic grid cell distribution shows a less subjective and more homogeneous intensity distribution than the classical irregular community distribution and helps to improve the calculation of intensity attenuation functions. In this presentation, the 'Did You Feel It' (DYFI) macroseismic data of several >M4, e.g. the 2002 ML 4.9 Alsdorf and 2011 ML 4.3 Goch (Germany) and the 2015 ML 4.1 Ramsgate (UK), earthquakes felt in Belgium, Germany, The Netherlands, France, Luxemburg and UK are analysed. Integration of transfrontier DYFI data of the ROB-BNS, KNMI, BCSF and BGS networks results in a particular non-circular, distribution of the macroseismic data in which the felt area for all these examples extends significantly more in E-W than N-S direction. This intensity distribution cannot be explained by geometrical amplitude attenuation alone, but rather illustrates a low-pass filtering effect due to the south-to-north increasing thickness of cover sediments above the London-Brabant Massif. For the studied M4 to M5 earthquakes, the thick sediments attenuate seismic energy at higher frequencies and consequently less people feel the vibrations at the surface. This example of successful macroseismic data exchange

High energy-intensity atomic oxygen beam source for low earth orbit materials degradation studies

International Nuclear Information System (INIS)

Cross, J.B.; Blais, N.C.

1988-01-01

A high intensity (10 19 O-atoms/s-sr) high energy (5 eV) source of oxygen atoms has been developed that produces a total fluence of 10 22 O-atoms/cm 2 in less than 100 hours of continuous operation at a distance of 15 cm from the source. The source employs a CW CO 2 laser sustained discharge to form a high temperature (15,000 K) plasma in the throat of a 0.3-mm diameter nozzle using 3--8 atmospheres of rare gas/O 2 mixtures. Visible and infrared photon flux levels of 1 watt/cm 2 have been measured 15 cm downstream of the source while vacuum UV (VUV) fluxes are comparable to that measured in low earth orbit. The reactions of atomic oxygen with kapton, Teflon, silver, and various coatings have been studied. The oxidation of kapton (reaction efficiency = 3 /times/ 10/sup /minus/24/ cm /+-/ 50%) has an activation energy of 0.8 Kcal/mole over the temperature range of 25/degree/C to 100/degree/C at a beam energy of 1.5 eV and produces low molecular weight gas phase reaction products (H 2 O, NO, CO 2 ). Teflon reacts with ∼0.1--0.2 efficiency to that of kapton at 25/degree/C and both surfaces show a rug-like texture after exposure to the O-atom beam. Angular scattering distribution measurements of O-atoms show a near cosine distribution from reactive surfaces indicating complete accommodation of the translational energy with the surface while a nonreactive surface (nickel oxide) shows specular-like scattering with 50% accommodation of the translational energy with the surface. A technique for simple on orbit chemical experiments using resistance measurements of coated silver strips is described. 9 figs

Technical characterization of an ultrasound source for noninvasive thermoablation by high-intensity focused ultrasound.

Science.gov (United States)

Köhrmann, K U; Michel, M S; Steidler, A; Marlinghaus, E; Kraut, O; Alken, P

2002-08-01

To develop a generator for high-intensity focused ultrasound (HIFU, a method of delivering ultrasonic energy with resultant heat and tissue destruction to a tight focus at a selected depth within the body), designed for extracorporeal coupling to allow various parenchymal organs to be treated. The ultrasound generated by a cylindrical piezo-ceramic element is focused at a depth of 10 cm using a parabolic reflector with a diameter of 10 cm. A diagnostic B-mode ultrasonographic transducer is integrated into the source to allow the focus to be located in the target area. The field distribution of the sound pressure was measured in degassed water using a needle hydrophone. An ultrasound-force balance was used to determine the acoustic power. These measurements allowed the spatially averaged sound intensity to be calculated. The morphology and extent of tissue necrosis induced by HIFU was examined on an ex-vivo kidney model. The two-dimensional field distribution resulted in an approximately ellipsoidal focus of 32 x 4 mm (- 6 dB). The spatially maximum averaged sound intensity was 8591 W/cm2 at an electrical power of 400 W. The lesion caused to the ex-vivo kidney at this maximum generator power with a pulse duration of 2 s was a clearly delineated ellipsoidal coagulation necrosis up to 8.8 x 2.3 mm (length x width) and with central liquefied necrosis of 7.9 x 1.9 mm. This newly developed ultrasound generator with a focal length of 10 cm can induce clear necrosis in parenchymal tissue. Because of its specific configuration and the available power range of the ultrasound generator, there is potential for therapeutic noninvasive ablation of tissue deep within a patient's body.

Obtaining better performance in the measurement-device-independent quantum key distribution with heralded single-photon sources

Science.gov (United States)

Zhou, Xing-Yu; Zhang, Chun-Hui; Zhang, Chun-Mei; Wang, Qin

2017-11-01

Measurement-device-independent quantum key distribution (MDI-QKD) has been widely investigated due to its remarkable advantages on the achievable transmission distance and practical security. However, the relative low key generation rate limits its real-life implementations. In this work, we adopt the newly proposed four-intensity decoy-state scheme [Phys. Rev. A 93, 042324 (2016), 10.1103/PhysRevA.93.042324] to study the performance of MDI-QKD with heralded single-photon sources (HSPS). Corresponding simulation results demonstrate that the four-intensity decoy-state scheme combining HSPS can drastically improve both the key generation rate and transmission distance in MDI-QKD, which may be very promising in future MDI-QKD systems.

Proton induction linacs as high-intensity neutron sources

International Nuclear Information System (INIS)

Keefe, D.; Hoyer, E.

1981-01-01

Proton induction linacs are explored as high intensity neutron sources. The induction linac - concept, properties, experience with electrons, and possibilities - and its limitations for accelerating ions are reviewed. A number of proton induction linac designs are examined with the LIACEP program and general conclusions are given. Results suggest that a proton induction accelerator of the lowest voltage, consistent with good neutron flux, is preferred and could well be cost competitive with the usual rf linac/storage ring designs. (orig.)

Intense neutron source facility for the fusion energy program

International Nuclear Information System (INIS)

Armstrong, D.D.; Emigh, C.R.; Meier, K.L.; Meyer, E.A.; Schneider, J.D.

1975-01-01

The Intense Neutron Source Facility, INS, has been proposed to provide a neutronic environment similar to that anticipated in a fully operational fusion-power reactor. The neutron generator will produce an intense flux of 14-MeV neutrons greater than 10 14 neutrons per cm 2 /sec from the collision of two intersecting beams, one of 1.1 A of 270 keV tritium ions and the other of a supersonic jet of deuterium gas. Using either the pure 14-MeV primary neutron spectrum or by tailoring the spectrum with appropriate moderators, crucial radiation-damage effects which are likely to occur in fusion reactors can be thoroughly explored and better understood

The Influence of Soil Moisture and Wind on Rainfall Distribution and Intensity in Florida

Science.gov (United States)

Baker, R. David; Lynn, Barry H.; Boone, Aaron; Tao, Wei-Kuo

1998-01-01

Land surface processes play a key role in water and energy budgets of the hydrological cycle. For example, the distribution of soil moisture will affect sensible and latent heat fluxes, which in turn may dramatically influence the location and intensity of precipitation. However, mean wind conditions also strongly influence the distribution of precipitation. The relative importance of soil moisture and wind on rainfall location and intensity remains uncertain. Here, we examine the influence of soil moisture distribution and wind distribution on precipitation in the Florida peninsula using the 3-D Goddard Cumulus Ensemble (GCE) cloud model Coupled with the Parameterization for Land-Atmosphere-Cloud Exchange (PLACE) land surface model. This study utilizes data collected on 27 July 1991 in central Florida during the Convection and Precipitation Electrification Experiment (CaPE). The idealized numerical experiments consider a block of land (the Florida peninsula) bordered on the east and on the west by ocean. The initial soil moisture distribution is derived from an offline PLACE simulation, and the initial environmental wind profile is determined from the CaPE sounding network. Using the factor separation technique, the precise contribution of soil moisture and wind to rainfall distribution and intensity is determined.

Effect of spatial distribution of tastants on taste intensity, fluctuation of taste intensity and consumer preference of (semi-)solid food products

NARCIS (Netherlands)

Mosca, A.C.; Bult, J.H.F.; Stieger, M.A.

2013-01-01

Two sensory studies were carried out to compare the taste intensity, the perceived fluctuation of taste intensity and the consumer preference of food products with homogeneous and inhomogeneous distributions of tastants using 2-alternative forced choice tests. The first study evaluated pairs of

The MIT/OSO 7 catalog of X-ray sources - Intensities, spectra, and long-term variability

Science.gov (United States)

Markert, T. H.; Laird, F. N.; Clark, G. W.; Hearn, D. R.; Sprott, G. F.; Li, F. K.; Bradt, H. V.; Lewin, W. H. G.; Schnopper, H. W.; Winkler, P. F.

1979-01-01

This paper is a summary of the observations of the cosmic X-ray sky performed by the MIT 1-40-keV X-ray detectors on OSO 7 between October 1971 and May 1973. Specifically, mean intensities or upper limits of all third Uhuru or OSO 7 cataloged sources (185 sources) in the 3-10-keV range are computed. For those sources for which a statistically significant (greater than 20) intensity was found in the 3-10-keV band (138 sources), further intensity determinations were made in the 1-15-keV, 1-6-keV, and 15-40-keV energy bands. Graphs and other simple techniques are provided to aid the user in converting the observed counting rates to convenient units and in determining spectral parameters. Long-term light curves (counting rates in one or more energy bands as a function of time) are plotted for 86 of the brighter sources.

Noise distribution of an incubator with nebulizer at a neonatal intensive care unit in southern Taiwan.

Science.gov (United States)

Chen, H F; Chang, Y J

2001-06-01

The purpose of this study was to investigate the noise distribution and sources of peak noise inside an incubator with a nebulizer at a neonatal intensive care unit of a medical center in Southern Taiwan. Sound levels were monitored continuously with an electronic sound-meter for 24 hours daily over a one-week period. Three working hours (day, evening, and night hours) in the weekday and weekend (total 48 hours) were selected randomly from the one-week period of noise survey to observe peak noise at levels > or = 65 dBA. Results revealed that 24.8% of the total monitoring period had sound levels at or = 70 dBA. Furthermore, a total of 947 peak noises > or = 65 dBA were found within the 48 hours, of which 61.5% were in a range of 65-69 dBA, 24% of 70-74 dBA, 9.8% of 75-79 dBA, and 4.8% > or = 80 dBA. Human-related sources, equaling 79%, were the dominant peak noises. These noises included opening and closing doors, banging the incubator hood, conversation among staff, nursing activity inside the incubator, tearing and opening paper or bags, opening and closing trash can lids, and bumping metal carts or other apparatus. Nonhuman-related sources were 21% including alarms of monitors and running of the incubator motor. Results of this study showed that the noise distribution in the incubator with nebulizer was far above a protective limitation of 58 dBA, suggested by the American Academy of Pediatrics in 1974. However, most peak noises could be reduced by modification of staff behavior. Therefore, determinations of noise distribution and sources of peak noise in this study are useful for further noise reduction programs.

Status of spallation neutron source program in High Intensity Proton Accelerator Project

International Nuclear Information System (INIS)

Oyama, Yukio

2001-01-01

Japan Atomic Energy Research Institute and High Energy Accelerator Organization are jointly designing a 1 MW spallation neutron source as one of the research facilities planned in the High Intensity Proton Accelerator Project. The spallation neutron source is driven by 3 GeV proton beam with a mercury target and liquid hydrogen moderators. The present status of design for these spallation source and relevant facility is overviewed. (author)

Transluminal color-coded three-dimensional magnetic resonance angiography for visualization of signal Intensity distribution pattern within an unruptured cerebral aneurysm: preliminarily assessment with anterior communicating artery aneurysms

International Nuclear Information System (INIS)

Satoh, T.; Ekino, C.; Ohsako, C.

2004-01-01

The natural history of unruptured cerebral aneurysm is not known; also unknown is the potential growth and rupture in any individual aneurysm. The authors have developed transluminal color-coded three-dimensional magnetic resonance angiography (MRA) obtained by a time-of-flight sequence to investigate the interaction between the intra-aneurysmal signal intensity distribution patterns and configuration of unruptured cerebral aneurysms. Transluminal color-coded images were reconstructed from volume data of source magnetic resonance angiography by using a parallel volume-rendering algorithm with transluminal imaging technique. By selecting a numerical threshold range from a signal intensity opacity chart of the three-dimensional volume-rendering dataset several areas of signal intensity were depicted, assigned different colors, and visualized transparently through the walls of parent arteries and an aneurysm. Patterns of signal intensity distribution were analyzed with three operated cases of an unruptured anterior communicating artery aneurysm and compared with the actual configurations observed at microneurosurgery. A little difference in marginal features of an aneurysm was observed; however, transluminal color-coded images visualized the complex signal intensity distribution within an aneurysm in conjunction with aneurysmal geometry. Transluminal color-coded three-dimensional magnetic resonance angiography can thus provide numerical analysis of the interaction between spatial signal intensity distribution patterns and aneurysmal configurations and may offer an alternative and practical method to investigate the patient-specific natural history of individual unruptured cerebral aneurysms. (orig.)

A Method of Estimating Pressure and Intensity Distributions of Multielement Phased Array High Intensity Focused Ultrasonic Field at Full Power Using a Needle Hydrophone

International Nuclear Information System (INIS)

Yu Ying; Shen Guofeng; Bai Jingfeng; Chen Yazhu

2011-01-01

The pressure and intensity distribution of high intensity focused ultrasound (HIFU) fields at full power are critical for predicting heating patterns and ensuring safety of the therapy. With the limitations of maximum pressure at the hydrophone and damage from cavitation or thermal effects, it is hard to measure pressure and intensity directly when HIFU is at full power. HIFU-phased arrays are usually composed of large numbers of small elements and the sound power radiated from some of them at full power is measureable using a hydrophone, we grouped them based on the limitation of maximum permissible pressure at the hydrophone and the characteristics of the element arrangement in the array. Then sound field measurement of the group was carried out at full power level. Using the acoustic coherence principle, the pressure and intensity distribution of the array at full power level can be calculated from corresponding values from the groups. With this method, computer simulations and sound field measurement of a 65-element concentric distributed phased array was carried out. The simulation results demonstrate theoretically the feasibility of this method. Measurements on the 65-element phased array also verify the effectiveness of this method for estimating the pressure and intensity distribution of phased array at full power level using a needle hydrophone.

A new laser vibrometry-based 2D selective intensity method for source identification in reverberant fields: part II. Application to an aircraft cabin

International Nuclear Information System (INIS)

Revel, G M; Martarelli, M; Chiariotti, P

2010-01-01

The selective intensity technique is a powerful tool for the localization of acoustic sources and for the identification of the structural contribution to the acoustic emission. In practice, the selective intensity method is based on simultaneous measurements of acoustic intensity, by means of a couple of matched microphones, and structural vibration of the emitting object. In this paper high spatial density multi-point vibration data, acquired by using a scanning laser Doppler vibrometer, have been used for the first time. Therefore, by applying the selective intensity algorithm, the contribution of a large number of structural sources to the acoustic field radiated by the vibrating object can be estimated. The selective intensity represents the distribution of the acoustic monopole sources on the emitting surface, as if each monopole acted separately from the others. This innovative selective intensity approach can be very helpful when the measurement is performed on large panels in highly reverberating environments, such as aircraft cabins. In this case the separation of the direct acoustic field (radiated by the vibrating panels of the fuselage) and the reverberant one is difficult by traditional techniques. The work shown in this paper is the application of part of the results of the European project CREDO (Cabin Noise Reduction by Experimental and Numerical Design Optimization) carried out within the framework of the EU. Therefore the aim of this paper is to illustrate a real application of the method to the interior acoustic characterization of an Alenia Aeronautica ATR42 ground test facility, Alenia Aeronautica being a partner of the CREDO project

A high-intensity He-jet production source for radioactive beams

International Nuclear Information System (INIS)

Vieira, D.J.; Kimberly, H.J.; Grisham, D.L.; Talbert, W.L.; Wouters, J.M.; Rosenauer, D.; Bai, Y.

1993-01-01

The use of a thin-target, He-jet transport system operating with high primary beam intensities is explored as a high-intensity production source for radioactive beams. This method is expected to work well for short-lived, non-volatile species. As such the thin-target, He-jet approach represents a natural complement to the thick-target ISOL method in which such species are not, in general, rapidly released. Highlighted here is a thin-target, He-jet system that is being prepared for a 500 + μA, 800-MeV proton demonstration experiment at LAMPF this summer

The proposed INEL intense slow positron source, beam line, and positron microscope facility

International Nuclear Information System (INIS)

Makowitz, H.; Denison, A.B.; Brown, B.

1993-01-01

A program is currently underway at the Idaho National Engineering Laboratory (INEL) to design and construct an Intense Slow Positron Beam Facility with an associated Positron Microscope. Positron beams have been shown to be valuable research tools and have potential application in industrial processing and nondestructive evaluation (microelectronics, etc.). The limit of resolution or overall usefulness of the technique has been limited because of lack of sufficient intensity. The goal of the INEL positron beam is ≥ 10 12 slow e+/s over a 0.03 cm diameter which represents a 10 3 to 10 4 advancement in beam current over existing beam facilities. The INEL is an ideal site for such a facility because of the nuclear reactors capable of producing intense positron sources and the personnel and facilities capable of handling high levels of radioactivity. A design using 58 Co with moderators and remoderators in conjunction with electrostatic positron beam optics has been reached after numerous computer code studies. Proof-of-principle electron tests have demonstrated the feasibility of the large area source focusing optics. The positron microscope development is occurring in conjunction with the University of Michigan positron microscope group. Such a Beam Facility and associated Intense Slow Positron Source (ISPS) can also be utilized for the generation and study of positron, and positron electron plasmas at ≤ 10 14 particles/cm 3 with plasma temperatures ranging from an eV to many keV, as well as an intense x-ray source via positron channeling radiation. The possibility of a tunable x-ray laser based on channeling positron radiation also exists. In this discussion the authors will present a progress report on various activities associated with the INEL ISPS

High intensity metallic ion beams from an ecr ion source at GANIL

International Nuclear Information System (INIS)

Leherissier, P.; Barue, C.; Canet, C.; Dupuis, M.; Flambard, J.L.; Gaubert, G.; Gibouin, S.; Huguet, Y.; Jardin, P.; Lecesne, N.; Lemagnen, F.; Leroy, R.; Pacquet, J.Y.; Pellemoine-Landre, F.; Rataud, J.P.; Jaffres, P.A.

2001-01-01

In the recent years, progress concerning the production of high intensity of metallic ions beams ( 58 Ni, 48 Ca, 76 Ge) at Ganil have been performed. The MIV0C method has been successfully used to produce a high intensity nickel beam with the ECR4 ion source: 20 eμA of 58 Ni 11+ at 24 kV extraction voltage. This beam has been maintained for 8 days and accelerated up to 74.5 MeV/u by our cyclotrons with a mean intensity of 0.13 pμA on target. This high intensity, required for experiment, led to the discovery of the doubly magic 48 Ni isotope. The oven method has been first tested with natural metallic calcium on the ECR4 ion source, then used to produce a high power beam (740 W on target i.e. 0.13 pμA accelerated up to 60 MeV/u) of 48 Ca still keeping a low consumption (0.09 mg/h). A germanium beam is now under development, using the oven method with germanium oxide. The ionization efficiencies have been measured and compared. (authors)

The Competition Between a Localised and Distributed Source of Buoyancy

Science.gov (United States)

Partridge, Jamie; Linden, Paul

2012-11-01

We propose a new mathematical model to study the competition between localised and distributed sources of buoyancy within a naturally ventilated filling box. The main controlling parameters in this configuration are the buoyancy fluxes of the distributed and local source, specifically their ratio Ψ. The steady state dynamics of the flow are heavily dependent on this parameter. For large Ψ, where the distributed source dominates, we find the space becomes well mixed as expected if driven by an distributed source alone. Conversely, for small Ψ we find the space reaches a stable two layer stratification. This is analogous to the classical case of a purely local source but here the lower layer is buoyant compared to the ambient, due to the constant flux of buoyancy emanating from the distributed source. The ventilation flow rate, buoyancy of the layers and also the location of the interface height, which separates the two layer stratification, are obtainable from the model. To validate the theoretical model, small scale laboratory experiments were carried out. Water was used as the working medium with buoyancy being driven directly by temperature differences. Theoretical results were compared with experimental data and overall good agreement was found. A CASE award project with Arup.

New results in the relation between intensity distribution of reflected molecular beams and spatial distribution of elementary crystal cells in solids

International Nuclear Information System (INIS)

Nikuradse, A.; Weidner, J.

1974-01-01

Analytic expressions for the intensity distribution of a molecular beam reflected by a solid surface which consists of face centered cubic elementary cells have been studied. One has also tried to study the influence of the spatial distribution of the elementary crystal cells on the intensity of reflection. Some curves which had been evaluated and designed by a computer are now published. The Kratzer potential of interaction has alway been supposed [fr

MR imaging of the bone marrow using short TI IR, 1. Normal and pathological intensity distribution of the bone marrow

Energy Technology Data Exchange (ETDEWEB)

Ishizaka, Hiroshi; Kurihara, Mikiko; Tomioka, Kuniaki; Kobayashi, Kanako; Sato, Noriko; Nagai, Teruo; Heshiki, Atsuko; Amanuma, Makoto; Mizuno, Hitomi.

1989-02-01

Normal vertebral bone marrow intensity distribution and its alteration in various anemias were evaluated on short TI IR sequences. Material consists of 73 individuals, 48 normals and 25 anemic patients excluding neoplastic conditions. All normal and reactive hypercellular bone marrow revealed characteristic intensity distribution; marginal high intensity and central low intensity, corresponding well to normal distribution of red and yellow marrows and their physiological or reactive conversion between red and yellow marrows. Aplastic anemia did not reveal normal intensity distribution, presumably due to autonomous condition.

Calculation of spatial distribution of the EURACOS II converter source

International Nuclear Information System (INIS)

Santo, A.C.F. de

1985-01-01

It is obtained the neutron spatial flux from the EURACOS (Enriched Uranium Converter Source) device, adjusted to experimental measures. The EURACOS device is a converter source which is constituted a circle plate of highly enriched uranium (90%). The converter provides an intense source of fast neutrons which has the energetic spectrum near to the fission spectrum. (M.C.K.) [pt

Physics of high intensity nanosecond electron source

International Nuclear Information System (INIS)

Herrera-Gomez, A.; Spicer, W.E.

1993-08-01

A new high-intensity, short-time electron source is now being used at the Stanford Linear Accelerator Center (SLAC). Using a GaAs negative affinity semiconductor in the construction of the cathode, it is possible to fulfill operation requirements such as peak currents of tens of amperes, peak widths of the order of nanoseconds, hundreds of hours of operation stability, and electron spin polarization. The cathode is illuminated with high intensity laser pulses, and photoemitted electrons constitute the yield. Because of the high currents, some nonlinear effects are present. Very noticeable is the so-called Charge Limit (CL) effect, which consists of a limit on the total charge in each pulse-that is, the total bunch charge stops increasing as the light pulse total energy increases. In this paper, we explain the mechanism of the CL and how it is caused by the photovoltaic effect. Our treatment is based on the Three-Step model of photoemission. We relate the CL to the characteristics of the surface and bulk of the semiconductor, such as doping, band bending, surface vacuum level, and density of surface states. We also discuss possible ways to prevent the Char's Level effect

Status of the intense pulsed neutron source

International Nuclear Information System (INIS)

Carpenter, J.M.; Brown, B.S.; Kustom, R.L.; Lander, G.H.; Potts, C.W.; Schulke, A.W.; Wuestefeld, G.

1985-01-01

Fortunately in spite of some premature reports of its impending demise, IPNS has passed the fourth anniversary of the first delivery of protons to the targets (May 5, 1981) and is approaching the fourth anniversary of its operation as a scattering facility (August 4, 1981). On June 10, 1984, the RCS delivered its one billionth pulse to the IPNS target - the total number of protons delivered to the targets amounted then to 75 stp cm 3 of H 2 gas. Since startup IPNS has improved steadily in terms of the performance of the Rapid Cycling Synchrotron, the source and its moderators and the scattering instruments, and a substantial and productive user program has evolved. This report summarizes the current status of the Intense Pulsed Neutron Source at Argonne National Laboratory. We include reference to recent accelerator operating experience, neutron facility operating experience, improvements to these systems, design work on the ASPUN high-current facility, booster target design, the new solid methane moderator, characterization of the room temperature moderators, and provide some examples of recent results from several of the spectrometers

Optimal distribution of integration time for intensity measurements in degree of linear polarization polarimetry.

Science.gov (United States)

Li, Xiaobo; Hu, Haofeng; Liu, Tiegen; Huang, Bingjing; Song, Zhanjie

2016-04-04

We consider the degree of linear polarization (DOLP) polarimetry system, which performs two intensity measurements at orthogonal polarization states to estimate DOLP. We show that if the total integration time of intensity measurements is fixed, the variance of the DOLP estimator depends on the distribution of integration time for two intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the DOLP estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time in an approximate way by employing Delta method and Lagrange multiplier method. According to the theoretical analyses and real-world experiments, it is shown that the variance of the DOLP estimator can be decreased for any value of DOLP. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improve the measurement accuracy of the polarimetry system.

DEEP WIDEBAND SINGLE POINTINGS AND MOSAICS IN RADIO INTERFEROMETRY: HOW ACCURATELY DO WE RECONSTRUCT INTENSITIES AND SPECTRAL INDICES OF FAINT SOURCES?

Energy Technology Data Exchange (ETDEWEB)

Rau, U.; Bhatnagar, S.; Owen, F. N., E-mail: rurvashi@nrao.edu [National Radio Astronomy Observatory, Socorro, NM-87801 (United States)

2016-11-01

Many deep wideband wide-field radio interferometric surveys are being designed to accurately measure intensities, spectral indices, and polarization properties of faint source populations. In this paper, we compare various wideband imaging methods to evaluate the accuracy to which intensities and spectral indices of sources close to the confusion limit can be reconstructed. We simulated a wideband single-pointing (C-array, L-Band (1–2 GHz)) and 46-pointing mosaic (D-array, C-Band (4–8 GHz)) JVLA observation using a realistic brightness distribution ranging from 1 μ Jy to 100 mJy and time-, frequency-, polarization-, and direction-dependent instrumental effects. The main results from these comparisons are (a) errors in the reconstructed intensities and spectral indices are larger for weaker sources even in the absence of simulated noise, (b) errors are systematically lower for joint reconstruction methods (such as Multi-Term Multi-Frequency-Synthesis (MT-MFS)) along with A-Projection for accurate primary beam correction, and (c) use of MT-MFS for image reconstruction eliminates Clean-bias (which is present otherwise). Auxiliary tests include solutions for deficiencies of data partitioning methods (e.g., the use of masks to remove clean bias and hybrid methods to remove sidelobes from sources left un-deconvolved), the effect of sources not at pixel centers, and the consequences of various other numerical approximations within software implementations. This paper also demonstrates the level of detail at which such simulations must be done in order to reflect reality, enable one to systematically identify specific reasons for every trend that is observed, and to estimate scientifically defensible imaging performance metrics and the associated computational complexity of the algorithms/analysis procedures.

The influence of external source intensity in accelerator/target/blanket system on conversion ratio and fuel cycle

Energy Technology Data Exchange (ETDEWEB)

Kochurov, B.P. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

1995-10-01

The analysis of neutron balance relation for a subcritical system with external source shows that a high ratio of neutron utilization (conversion ratio, breeding ratio) much exceeding similar values for nuclear reactors (both thermal or fast spectrum) is reachable in accelerator/target/blanket system with high external neutron source intensity. An accelerator/target/blanket systems with thermal power in blanket about 1850 Mwt and operating during 30 years have been investigated. Continual feed up by plutonium (fissile material) and Tc-99 (transmuted material) was assumed. Accelerator beam intensity differed 6.3 times (16 mA - Case 1, and 100 mA-Case 2). Conversion ratio (CR) was defined as the ratio of Tc-99 nuclei transmuted to the number of Pu nuclei consumed. High value of conversion ratio considerably exceeding 1 (CR=1.66) was obtained in the system with high source intensity as compared with low source system (CR=0.77). Net output of electric power of high source intensity system is about twice lower due to consumption of electric power for accelerator feed up. The loss of energy for Tc-99 transmutation is estimated as 40 Mev(el)/nuclei. Yet high conversion ratio (or breeding ratio) achievable in electronuclear installations with high intensity of external source can effectively be used to close fuel cycle (including incineration of wastes) or to develop growing nuclear power production system.

Mapping the continuous reciprocal space intensity distribution of X-ray serial crystallography.

Science.gov (United States)

Yefanov, Oleksandr; Gati, Cornelius; Bourenkov, Gleb; Kirian, Richard A; White, Thomas A; Spence, John C H; Chapman, Henry N; Barty, Anton

2014-07-17

Serial crystallography using X-ray free-electron lasers enables the collection of tens of thousands of measurements from an equal number of individual crystals, each of which can be smaller than 1 µm in size. This manuscript describes an alternative way of handling diffraction data recorded by serial femtosecond crystallography, by mapping the diffracted intensities into three-dimensional reciprocal space rather than integrating each image in two dimensions as in the classical approach. We call this procedure 'three-dimensional merging'. This procedure retains information about asymmetry in Bragg peaks and diffracted intensities between Bragg spots. This intensity distribution can be used to extract reflection intensities for structure determination and opens up novel avenues for post-refinement, while observed intensity between Bragg peaks and peak asymmetry are of potential use in novel direct phasing strategies.

Status of the intense pulsed neutron source

International Nuclear Information System (INIS)

Brown, B.S.; Carpenter, J.M.; Crawford, R.K.; Rauchas, A.V.; Schulke, A.W.; Worlton, T.G.

1989-01-01

Since 1981 the average proton currents at IPNS has increased substantially. The reliability has averaged 91%. The moderator has changed from a room temperature polyethylene to cryogenic methane. This report details progress made at IPNS (Intense Pulsed Neutron Source) during the last two years. The topics discussed are the operating status of the accelerator systems, other accelerator activities (such as, IPNS participation in SDI), instrumentation operating at IPNS, chopper development at IPNS, data acquisition, Booster target, moderators and examples of recent scientific results. The ever increasing instrument capability, the Booster target and the very active involvement with the scientific user community guarantees a productive scientific future at IPNS. 9 figs., 3 tabs

A tunable, linac based, intense, broad-band THz source forpump-probe experiments

Energy Technology Data Exchange (ETDEWEB)

Schmerge, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Adolphsen, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Corbett, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Dolgashev, V. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Durr, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fazio, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fisher, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Frisch, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gaffney, K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Guehr, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hastings, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hettel, B. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hoffmann, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hogan, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Holtkamp, N. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kirchmann, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); LaRue, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Limborg, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lindenberg, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Loos, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Maxwell, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nilsson, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Raubenheimer, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Reis, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ross, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shen, Z. -X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stupakov, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tantawi, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tian, K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wu, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Xiang, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Yakimenko, V. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2015-02-02

We propose an intense THz source with tunable frequency and bandwidth that can directly interact with the degrees of freedom that determine the properties of materials and thus provides a new tool for controlling and directing these ultrafast processes as well as aiding synthesis of new materials with new functional properties. This THz source will broadly impact our understanding of dynamical processes in matter at the atomic-scale and in real time. Established optical pumping schemes using femtosecond visible frequency laser pulses for excitation are extended into the THz frequency regime thereby enabling resonant excitation of bonds in correlated solid state materials (phonon pumping), to drive low energy electronic excitations, to trigger surface chemistry reactions, and to all-optically bias a material with ultrashort electric fields or magnetic fields. A linac-based THz source can supply stand-alone experiments with peak intensities two orders of magnitude stronger than existing laser-based sources, but when coupled with atomic-scale sensitive femtosecond x-ray probes it opens a new frontier in ultrafast science with broad applications to correlated materials, interfacial and liquid phase chemistry, and materials in extreme conditions.

The Distribution of the Interval between Events of a Cox Process with Shot Noise Intensity

Directory of Open Access Journals (Sweden)

Angelos Dassios

2008-01-01

Full Text Available Applying piecewise deterministic Markov processes theory, the probability generating function of a Cox process, incorporating with shot noise process as the claim intensity, is obtained. We also derive the Laplace transform of the distribution of the shot noise process at claim jump times, using stationary assumption of the shot noise process at any times. Based on this Laplace transform and from the probability generating function of a Cox process with shot noise intensity, we obtain the distribution of the interval of a Cox process with shot noise intensity for insurance claims and its moments, that is, mean and variance.

Sky-distribution of intensity of synchrotron radio emission of relativistic electrons trapped in Earth’s magnetic field

Directory of Open Access Journals (Sweden)

Klimenko V.V.

2017-12-01

Full Text Available This paper presents the calculations of synchrotron radio emission intensity from Van Allen belts with Gaussian space distribution of electron density across L-shells of a dipole magnetic field, and with Maxwell’s relativistic electron energy distribution. The results of these calculations come to a good agreement with measurements of the synchrotron emission intensity of the artificial radiation belt’s electrons during the Starfish nuclear test. We have obtained two-dimensional distributions of radio brightness in azimuth — zenith angle coordinates for an observer on Earth’s surface. The westside and eastside intensity maxima exceed several times the maximum level of emission in the meridian plane. We have also constructed two-dimensional distributions of the radio emission intensity in decibels related to the background galactic radio noise level. Isotropic fluxes of relativistic electrons (Е~1 MeV should be more than 107 cm–2s–1 for the synchrotron emission intensity in the meridian plane to exceed the cosmic noise level by 0.1 dB (riometer sensitivity threshold.

Proposed second harmonic acceleration system for the intense pulsed neutron source rapid cycling synchrotron

International Nuclear Information System (INIS)

Norem, J.; Brandeberry, F.; Rauchas, A.

1983-01-01

The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2 to 2.5 x 10 12 protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at approx.3 x 10 12 ppp, depending somewhat on the available aperture. With the present good performance in mind, accelerator improvements are being directed at: (1) increasing beam intensities for neutron science; (2) lowering acceleration losses to minimize activation; and (3) gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. On the basis of preliminary measurements, we are now proposing a third cavity for the RF systems which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses

The Impact of Source Distribution on Scalar Transport over Forested Hills

Science.gov (United States)

Ross, Andrew N.; Harman, Ian N.

2015-08-01

Numerical simulations of neutral flow over a two-dimensional, isolated, forested ridge are conducted to study the effects of scalar source distribution on scalar concentrations and fluxes over forested hills. Three different constant-flux sources are considered that span a range of idealized but ecologically important source distributions: a source at the ground, one uniformly distributed through the canopy, and one decaying with depth in the canopy. A fourth source type, where the in-canopy source depends on both the wind speed and the difference in concentration between the canopy and a reference concentration on the leaf, designed to mimic deposition, is also considered. The simulations show that the topographically-induced perturbations to the scalar concentration and fluxes are quantitatively dependent on the source distribution. The net impact is a balance of different processes affecting both advection and turbulent mixing, and can be significant even for moderate topography. Sources that have significant input in the deep canopy or at the ground exhibit a larger magnitude advection and turbulent flux-divergence terms in the canopy. The flows have identical velocity fields and so the differences are entirely due to the different tracer concentration fields resulting from the different source distributions. These in-canopy differences lead to larger spatial variations in above-canopy scalar fluxes for sources near the ground compared to cases where the source is predominantly located near the canopy top. Sensitivity tests show that the most significant impacts are often seen near to or slightly downstream of the flow separation or reattachment points within the canopy flow. The qualitative similarities to previous studies using periodic hills suggest that important processes occurring over isolated and periodic hills are not fundamentally different. The work has important implications for the interpretation of flux measurements over forests, even in

Recent performance of the Intense Pulsed Neutron Source accelerator system

International Nuclear Information System (INIS)

Potts, C.; Brumwell, F.; Rauchas, A.; Stipp, V.; Volk, G.; Donley, L.

1987-03-01

The Intense Pulsed Neutron Source (IPNS) accelerator system has now been in operation as part of a national user program for over five years. During that period steady progress has been made in both beam intensity and reliability. Almost 1.8 billion pulses totaling 4 x 10 21 protons have now been delivered to the spallation neutron target. Recent weekly average currents have reached 15 μA (3.2 x 10 12 protons per pulse, 30 pulses per second) and short-term peaks of almost 17 μA have been reached. In fact, the average current for the last two years is up 31% over the average for the first three years of operation

Two-stage stochastic day-ahead optimal resource scheduling in a distribution network with intensive use of distributed energy resources

DEFF Research Database (Denmark)

Sousa, Tiago; Ghazvini, Mohammad Ali Fotouhi; Morais, Hugo

2015-01-01

The integration of renewable sources and electric vehicles will introduce new uncertainties to the optimal resource scheduling, namely at the distribution level. These uncertainties are mainly originated by the power generated by renewables sources and by the electric vehicles charge requirements....... This paper proposes a two-state stochastic programming approach to solve the day-ahead optimal resource scheduling problem. The case study considers a 33-bus distribution network with 66 distributed generation units and 1000 electric vehicles....

Utilizations of intense pulsed neutron source in radiochemistry and radiation chemistry

International Nuclear Information System (INIS)

Shiokawa, Takanobu; Yoshihara, Kenji; Kaji, Harumi; Kusaka, Yuzuru; Tabata, Yoneho.

1975-01-01

Intense pulsed neutron sources is expected to supply more useful and fundamental informations in radiochemistry and radiation chemistry. Short-lived intermediate species may be detected and the mechanisms of radiation induced reactions will be elucidated more precisely. Analytical application of pulsed neutrons is also very useful. (auth.)

From Intensity Profile to Surface Normal: Photometric Stereo for Unknown Light Sources and Isotropic Reflectances.

Science.gov (United States)

Lu, Feng; Matsushita, Yasuyuki; Sato, Imari; Okabe, Takahiro; Sato, Yoichi

2015-10-01

We propose an uncalibrated photometric stereo method that works with general and unknown isotropic reflectances. Our method uses a pixel intensity profile, which is a sequence of radiance intensities recorded at a pixel under unknown varying directional illumination. We show that for general isotropic materials and uniformly distributed light directions, the geodesic distance between intensity profiles is linearly related to the angular difference of their corresponding surface normals, and that the intensity distribution of the intensity profile reveals reflectance properties. Based on these observations, we develop two methods for surface normal estimation; one for a general setting that uses only the recorded intensity profiles, the other for the case where a BRDF database is available while the exact BRDF of the target scene is still unknown. Quantitative and qualitative evaluations are conducted using both synthetic and real-world scenes, which show the state-of-the-art accuracy of smaller than 10 degree without using reference data and 5 degree with reference data for all 100 materials in MERL database.

Space power distribution of soft x-ray source ANGARA-5-1

Energy Technology Data Exchange (ETDEWEB)

Dyabilin, K S [High Energy Density Research Center, Moscow (Russian Federation); Fortov, V E; Grabovskij, E V; Lebedev, M E; Smirnov, V P [Troitsk Inst. of Innovative and Fusion Research, Troitsk (Russian Federation)

1997-12-31

The contribution deals with the investigation of shock waves in condensed targets generated by intense pulses of soft X radiation. Main attention is paid to the spatial distribution of the soft x-ray power, which influence strongly the shock wave front uniformity. Hot z-pinch plasma with the temperature of 60-100 eV produced by imploding double liner in the ANGARA-5-1 machine was used as a source of x rays. The maximum pinch current was as high as 3.5 MA. In order to eliminate the thermal heating of the targets, thick stepped Al/Pb, Sn/Pb, or pure Pb targets were used. The velocity of shock waves was determined by means of optical methods. Very uniform shock waves and shock pressures of up to several hundreds of GPa have been achieved. (J.U.). 3 figs., 2 refs.

High intensity metallic ion beam from an ecr ion source using the Mivoc method

International Nuclear Information System (INIS)

Barue, C.; Canet, C.; Dupuis, M.; Flambard, J.L.; Leherissier, P.; Lemagnen, F.; Jaffres, P.A.

2000-01-01

The MIVOC method has been successfully used at GANIL to produce a high intensity nickel beam with the ECR4 ion source: 20 μA 58 Ni 11+ at 24 kV extraction voltage. This beam has been maintained for 8 days and accelerated up to 74.5 MeV/u by our cyclotrons with a mean intensity of 0.13 pμA on target. This high intensity, required for experiment, led to the discovery of the doubly magic 48 Ni isotope. Experimental setup, handling and off-line preparation using a residual gas analyzer are described in this report. The ion source behavior, performances and limitations are presented in the case of nickel and iron. The ionization efficiencies have been measured and compared to the oven method usually used at GANIL. (author)

High intensity negative proton beams from a SNICS ion source

International Nuclear Information System (INIS)

Evans, C.R.; Hollander, M.G.

1991-01-01

For the past year we have been involved in a project to develop an intense (> 100μA) negative proton beam from a SNICS (Source of Negative Ions by Cesium Sputtering) ion source. This report will cover how we accomplished and exceeded this goal by more than 40%. Included in these observations will be the following: A description of an effective method for making titanium hydride cathodes. How to overcome the limitations of the titanium hydride cathode. The modification of the SNICS source to improve output; including the installation of the conical ionizer and the gas cathode. A discussion of problems including: poisoning the proton beam with oxygen, alternative gas cathode materials, the clogging of the gas inlet, long burn-in times, and limited cathode life times. Finally, how to optimize source performance when using a gas cathode, and what is the mechanism by which a gas cathode operates; facts, fantasies, or myth

A feasibility study of high intensity positron sources for the S-band and TESLA linear colliders

Energy Technology Data Exchange (ETDEWEB)

Glantz, R.

1997-10-01

Future high energy linear colliders require luminosities above 10{sup 33} cm{sup -2}s{sup -1}. Therefore beam intensities have to be provided up to two orders of magnitude higher than achieved at present. It is comparably simple to reach high electron intensities. Positron intensities in this range, however, are difficult to realize with conventional positron sources. A new method of positron production was proposed in 1979 by V.E. Balakin and A.A. Mikhailichenko. The photons, necessary for pair production, are not generated by bremsstrahlung but by high energy electrons passing through an undulator. Based on this principle, a high intensity, unpolarized and polarized positron source for linear colliders was developed by K.Floettmann. In the present work, the requirements derived by K.Floettmann are used to study the feasibility of both the polarized and the unpolarized positron source. For economical reasons it is advantageous to use the beam after the interaction for positron production. In the main part of the present work a beam line is developed which guarantees a stable operation of the unpolarized wiggler-based positron source for the S-Band and TESLA linear collider. The requirements on the electron beam emittances are much higher for the polarized undulator-based source. For TESLA it is shown, that an operation of the polarized source is possible for design interactions. For a stable operation, taking into account perturbations at the interaction point, further investigations are necessary. For the SBLC, an operation of the polarized source is not possible with the present design.

Brightness distribution data on 2918 radio sources at 365 MHz

International Nuclear Information System (INIS)

Cotton, W.D.; Owen, F.N.; Ghigo, F.D.

1975-01-01

This paper is the second in a series describing the results of a program attempting to fit models of the brightness distribution to radio sources observed at 365 MHz with the Bandwidth Synthesis Interferometer (BSI) operated by the University of Texas Radio Astronomy Observatory. Results for a further 2918 radio sources are given. An unresolved model and three symmetric extended models with angular sizes in the range 10--70 arcsec were attempted for each radio source. In addition, for 348 sources for which other observations of brightness distribution are published, the reference to the observations and a brief description are included

Accelerator-based intense neutron source for materials R ampersand D

International Nuclear Information System (INIS)

Jameson, R.A.

1990-01-01

Accelerator-based neutron sources for R ampersand D of materials in nuclear energy systems, including fusion reactors, can provide sufficient neutron flux, flux-volume, fluence and other attractive features for many aspects of materials research. The neutron spectrum produced from the D-Li reaction has been judged useful for many basic materials research problems, and to be a satisfactory approximation to that of the fusion process. The technology of high-intensity linear accelerators can readily be applied to provide the deuteron beam for the neutron source. Earlier applications included the Los Alamos Meson Physics Facility and the Fusion Materials Irradiation Test facility prototype. The key features of today's advanced accelerator technology are presented to illustrate the present state-of-the-art in terms of improved understanding of basic physical principles and engineering technique, and to show how these advances can be applied to present demands in a timely manner. These features include how to produce an intense beam current with the high quality required to minimize beam losses along the accelerator and transport system that could cause maintenance difficulties, by controlling the beam emittance through proper choice of the operating frequency, balancing of the forces acting on the beam, and realization in practical hardware. A most interesting aspect for materials researchers is the increased flexibility and opportunities for experimental configurations that a modern accelerator-based source could add to the set of available tools. 8 refs., 5 figs

Overview of high intensity x-ray and gamma-ray sources

International Nuclear Information System (INIS)

Prestwich, K.R.; Lee, J.R.; Ramirez, J.J.; Sanford, T.W.L.; Agee, F.J.; Frazier, G.B.; Miller, A.R.

1987-01-01

The requirements for intense x-ray and gamma-ray sources to simulate the radiation effects from nuclear weapons has led to the development of several types of terawatt-pulsed power systems. One example of a major gamma-ray source is Aurora, a 10-MV, 1.6-MA, 120-ns four-module, electron-beam generator. Recent requirements to improve the dose rate has led to the Aurora upgrade program and to the development of the 20-MV, 800-kA, 40-ns Hermes-III electron-beam accelerator. The Aurora program includes improvements to the pulsed power system and research on techniques to improve the pulse shape of the electron beam. Hermes III will feature twenty 1-MV, 800-kA induction accelerator cavities supplying energy to a magnetically insulated transmission line adder. Hermes III will become operational in 1988. Intense x-ray sources consist of pulsed power systems that operate with 1-MV to 2-MV output voltages and up to 25-TW output powers. These high powers are achieved with either low impedance electron-beam generators or multimodular pulsed power systems. The low-impedance generators have high voltage Marx generators that store the energy and then sequentially transfer this energy to pulse-forming transmission lines with lower and lower impedance until the high currents are reached. In the multimode machines, each module produces 0.7-TW to 4-TW output pulses, and all of the modules are connected together to supply energy to a single diode

Experimental comparison of phase retrieval methods which use intensity distribution at different planes

International Nuclear Information System (INIS)

Shevkunov, I A; Petrov, N V

2014-01-01

Performance of the three phase retrieval methods that use spatial intensity distributions was investigated in dealing with a task of reconstruction of the amplitude characteristics of the test object. These methods differ both by mathematical models and order of iteration execution. The single-beam multiple-intensity reconstruction method showed the best efficiency in terms of quality of reconstruction and time consumption.

Pulsed neutron source very intense, Booster

International Nuclear Information System (INIS)

Abbate, J.M.

1978-09-01

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

The dose distribution surrounding sup 192 Ir and sup 137 Cs seed sources

Energy Technology Data Exchange (ETDEWEB)

Thomason, C [Wisconsin Univ., Madison, WI (USA). Dept. of Medical Physics; Mackie, T R [Wisconsin Univ., Madison, WI (USA). Dept. of Medical Physics Wisconsin Univ., Madison, WI (USA). Dept. of Human Oncology; Lindstrom, M J [Wisconsin Univ., Madison, WI (USA). Biostatistics Center; Higgins, P D [Cleveland Clinic Foundation, OH (USA). Dept. of Radiation Oncology

1991-04-01

Dose distributions in water were measured using LiF thermoluminescent dosemeters for {sup 192}Ir seed sources with stainless steel and with platinum encapsulation to determine the effect of differing encapsulation. Dose distribution was measured for a {sup 137}Cs seed source. In addition, dose distributions surrounding these sources were calculated using the EGS4 Monte Carlo code and were compared to measured data. The two methods are in good agreement for all three sources. Tables are given describing dose distribution surrounding each source as a function of distance and angle. Specific dose constants were also determined from results of Monte Carlo simulation. This work confirms the use of the EGS4 Monte Carlo code in modelling {sup 192}Ir and {sup 137}Cs seed sources to obtain brachytherapy dose distributions. (author).

Rate-adaptive BCH codes for distributed source coding

DEFF Research Database (Denmark)

Salmistraro, Matteo; Larsen, Knud J.; Forchhammer, Søren

2013-01-01

This paper considers Bose-Chaudhuri-Hocquenghem (BCH) codes for distributed source coding. A feedback channel is employed to adapt the rate of the code during the decoding process. The focus is on codes with short block lengths for independently coding a binary source X and decoding it given its...... strategies for improving the reliability of the decoded result are analyzed, and methods for estimating the performance are proposed. In the analysis, noiseless feedback and noiseless communication are assumed. Simulation results show that rate-adaptive BCH codes achieve better performance than low...... correlated side information Y. The proposed codes have been analyzed in a high-correlation scenario, where the marginal probability of each symbol, Xi in X, given Y is highly skewed (unbalanced). Rate-adaptive BCH codes are presented and applied to distributed source coding. Adaptive and fixed checking...

Effect of source angular distribution on the evaluation of gamma-ray skyshine

Energy Technology Data Exchange (ETDEWEB)

Sheu, R.D.; Jiang, S.H. [Dept. of Engineering and System Science, National Tsing Hua Univ., Taiwan (China); Chang, B.J.; Chen, I.J. [Division of Health Physics, Inst. of Nuclear Energy Research, Taiwan (China)

2000-03-01

The effect of the angular distribution of the equivalent point source on the analysis of the skyshine dose rates was investigated in detail. The dedicated skyshine codes SKYDOSE and McSKY were revised to include the capability of dealing with the anisotropic source. It was found that a replace of the cosine-distributed source by an isotropic source will overestimate the skyshine dose rates for large roof-subtended angles and cause underestimation for small roof-subtended angles. For building with roof shielding, however, replacing the cosine-distributed source by an isotropic source will always underestimate the skyshine dose rates. The skyshine dose rates from a volume source calculated by the dedicated skyshine code agree very well with those of the MCNP Monte Carlo calculation. (author)

Curved-straight neutron guide system with uniform spatial intensity distribution

International Nuclear Information System (INIS)

Mildner, D.F.R.; Cook, J.C.

2008-01-01

The spatial intensity distribution of neutrons emerging from a curved guide is asymmetric, and straight guide sections are sometimes appended to curved guides to make the intensity distribution more nearly uniform. For idealized uniform illumination and in the perfect reflectivity approximation, the spatial-angular acceptance at the exit of the combination can be made exactly uniform for a range of long wavelengths by using a sufficiently long straight section, together with a curved guide whose outer wall coating has a critical angle slightly greater than those of the other guide walls. We refer to this as a 'phase space tailoring guide' where the coatings on the inner wall and straight section are used to define the required divergence at the end of the guide. Increasing the critical angle of the outer wall of the curved section reduces the characteristic wavelength of the curved guide as well as the wavelength at which ideal uniformity can be obtained. The outer wall coating need only be of sufficiently high critical angle to fill the transmittable phase space area of the straight guide uniformly to adequately short wavelength

Area radiation monitor at the intense pulsed-neutron source

International Nuclear Information System (INIS)

Eichholz, J.J.; Lynch, F.J.; Mundis, R.L.; Howe, M.L.; Dolecek, E.H.

1981-01-01

A tissue-equivalent ionization chamber with associated circuitry has been developed for area radiation monitoring in the Intense Pulsed-Neutron Source (IPNS) facility at Argonne National Laboratory. The conventional chamber configuration was modified in order to increase the electric field and effective volume thereby achieving higher sensitivity and linearity. The instrument provides local and remote radiation level indications and a high level alarm. Twenty-four of these instruments were fabricated for use at various locations in the experimental area of the IPNS-1 facility

Neutron spectra characteristics for the intense neutron source, INS

International Nuclear Information System (INIS)

Battat, M.; Dierckx, R.; Emigh, C.R.

1977-01-01

The Intense Neutron Source, INS, facility is presently under construction at the Los Alamos Scientific Laboratory. Its purpose is to provide a broad base for research work related to the radiation effects produced by 14-MeV neutrons from a D-T burn of a fusion reactor. The INS facility produces a D-T burn-like reaction from the collision of an intense tritium-ion beam with a supersonic jet target of deuterium gas. The reaction produces a typical D-T 14-MeV neutron spectrum. By adding a fission blanket surrounding the D-T ''burn,'' the neutron spectral shape may be tailored to match almost perfectly the anticipated first-wall spectra from presently proposed fusion reactors. With a blanket in place, the total production of neutrons can be as large as 3 x 10 16 n/s and experimental volumes of the order of 1000 cm 3 can be available at flux levels greater than 0.6 x 10 14 n/cm 2 s

Use of the spectral analysis for estimating the intensity of a weak periodic source

International Nuclear Information System (INIS)

Marseguerra, M.

1989-01-01

This paper deals with the possibility of exploiting spectral methods for the analysis of counting experiments in which one has to estimate the intensity of a weak periodic source of particles buried in a high background. The general theoretical expressions here obtained for the auto- and cross-spectra are applied to three kinds of simulated experiments. In all cases it turns out that the source intensity can acutally be estimated with a standard deviation comparable with that obtained in classical experiments in which the source can be moved out. Thus the spectral methods represent an interesting technique nowadays easy to implement on low-cost computers which could also be used in many research fields by suitably redesigning classical experiments. The convenience of using these methods in the field of nuclear safeguards is presently investigated in our Institute. (orig.)

Intense source of cold cesium atoms based on a two-dimensional magneto–optical trap with independent axial cooling and pushing

International Nuclear Information System (INIS)

Huang Jia-Qiang; Wu Chen-Fei; Wang Li-Jun; Yan Xue-Shu; Zhang Jian-Wei

2016-01-01

We report our studies on an intense source of cold cesium atoms based on a two-dimensional (2D) magneto–optical trap (MOT) with independent axial cooling and pushing. The new-designed source, proposed as 2D-HP MOT, uses hollow laser beams for axial cooling and a thin pushing laser beam to extract a cold atomic beam. With the independent pushing beam, the atomic flux can be substantially optimized. The total atomic flux maximum obtained in the 2D-HP MOT is 4.02 × 10 10 atoms/s, increased by 60 percent compared to the traditional 2D + MOT in our experiment. Moreover, with the pushing power 10 μW and detuning 0 Γ , the 2D-HP MOT can generate a rather intense atomic beam with the concomitant light shift suppressed by a factor of 20. The axial velocity distribution of the cold cesium beams centers at 6.8 m/s with an FMHW of about 2.8 m/s. The dependences of the atomic flux on the pushing power and detuning are studied in detail. The experimental results are in good agreement with the theoretical model. (paper)

Characterization of a Distributed Plasma Ionization Source (DPIS) for Ion Mobility Spectrometry and Mass Spectrometry

International Nuclear Information System (INIS)

Waltman, Melanie J.; Dwivedi, Prabha; Hill, Herbert; Blanchard, William C.; Ewing, Robert G.

2008-01-01

A recently developed atmospheric pressure ionization source, a distributed plasma ionization source (DPIS), was characterized and compared to commonly used atmospheric pressure ionization sources with both mass spectrometry and ion mobility spectrometry. The source consisted of two electrodes of different sizes separated by a thin dielectric. Application of a high RF voltage across the electrodes generated plasma in air yielding both positive and negative ions depending on the polarity of the applied potential. These reactant ions subsequently ionized the analyte vapors. The reactant ions generated were similar to those created in a conventional point-to-plane corona discharge ion source. The positive reactant ions generated by the source were mass identified as being solvated protons of general formula (H2O)nH+ with (H2O)2H+ as the most abundant reactant ion. The negative reactant ions produced were mass identified primarily as CO3-, NO3-, NO2-, O3- and O2- of various relative intensities. The predominant ion and relative ion ratios varied depending upon source construction and supporting gas flow rates. A few compounds including drugs, explosives and environmental pollutants were selected to evaluate the new ionization source. The source was operated continuously for several months and although deterioration was observed visually, the source continued to produce ions at a rate similar that of the initial conditions. The results indicated that the DPIS may have a longer operating life than a conventional corona discharge.

Deformation due to distributed sources in micropolar thermodiffusive medium

Directory of Open Access Journals (Sweden)

Sachin Kaushal

2010-10-01

Full Text Available The general solution to the field equations in micropolar generalized thermodiffusive in the context of G-L theory is investigated by applying the Laplace and Fourier transform's as a result of various sources. An application of distributed normal forces or thermal sources or potential sources has been taken to show the utility of the problem. To get the solution in the physical form, a numerical inversion technique has been applied. The transformed components of stress, temperature distribution and chemical potential for G-L theory and CT theory has been depicted graphically and results are compared analytically to show the impact of diffusion, relaxation times and micropolarity on these quantities. Some special case of interest are also deduced from present investigation.

The training intensity distribution among well-trained and elite endurance athletes

Science.gov (United States)

Stöggl, Thomas L.; Sperlich, Billy

2015-01-01

Researchers have retrospectively analyzed the training intensity distribution (TID) of nationally and internationally competitive athletes in different endurance disciplines to determine the optimal volume and intensity for maximal adaptation. The majority of studies present a “pyramidal” TID with a high proportion of high volume, low intensity training (HVLIT). Some world-class athletes appear to adopt a so-called “polarized” TID (i.e., significant % of HVLIT and high-intensity training) during certain phases of the season. However, emerging prospective randomized controlled studies have demonstrated superior responses of variables related to endurance when applying a polarized TID in well-trained and recreational individuals when compared with a TID that emphasizes HVLIT or threshold training. The aims of the present review are to: (1) summarize the main responses of retrospective and prospective studies exploring TID; (2) provide a systematic overview on TIDs during preparation, pre-competition, and competition phases in different endurance disciplines and performance levels; (3) address whether one TID has demonstrated greater efficacy than another; and (4) highlight research gaps in an effort to direct future scientific studies. PMID:26578968

Observations of a free-energy source for intense electrostatic waves. [in upper atmosphere near upper hybrid resonance frequency

Science.gov (United States)

Kurth, W. S.; Frank, L. A.; Gurnett, D. A.; Burek, B. G.; Ashour-Abdalla, M.

1980-01-01

Significant progress has been made in understanding intense electrostatic waves near the upper hybrid resonance frequency in terms of the theory of multiharmonic cyclotron emission using a classical loss-cone distribution function as a model. Recent observations by Hawkeye 1 and GEOS 1 have verified the existence of loss-cone distributions in association with the intense electrostatic wave events, however, other observations by Hawkeye and ISEE have indicated that loss cones are not always observable during the wave events, and in fact other forms of free energy may also be responsible for the instability. Now, for the first time, a positively sloped feature in the perpendicular distribution function has been uniquely identified with intense electrostatic wave activity. Correspondingly, we suggest that the theory is flexible under substantial modifications of the model distribution function.

On Road Study of Colorado Front Range Greenhouse Gases Distribution and Sources

Science.gov (United States)

Petron, G.; Hirsch, A.; Trainer, M. K.; Karion, A.; Kofler, J.; Sweeney, C.; Andrews, A.; Kolodzey, W.; Miller, B. R.; Miller, L.; Montzka, S. A.; Kitzis, D. R.; Patrick, L.; Frost, G. J.; Ryerson, T. B.; Robers, J. M.; Tans, P.

2008-12-01

The Global Monitoring Division and Chemical Sciences Division of the NOAA Earth System Research Laboratory have teamed up over the summer 2008 to experiment with a new measurement strategy to characterize greenhouse gases distribution and sources in the Colorado Front Range. Combining expertise in greenhouse gases measurements and in local to regional scales air quality study intensive campaigns, we have built the 'Hybrid Lab'. A continuous CO2 and CH4 cavity ring down spectroscopic analyzer (Picarro, Inc.), a CO gas-filter correlation instrument (Thermo Environmental, Inc.) and a continuous UV absorption ozone monitor (2B Technologies, Inc., model 202SC) have been installed securely onboard a 2006 Toyota Prius Hybrid vehicle with an inlet bringing in outside air from a few meters above the ground. To better characterize point and distributed sources, air samples were taken with a Portable Flask Package (PFP) for later multiple species analysis in the lab. A GPS unit hooked up to the ozone analyzer and another one installed on the PFP kept track of our location allowing us to map measured concentrations on the driving route using Google Earth. The Hybrid Lab went out for several drives in the vicinity of the NOAA Boulder Atmospheric Observatory (BAO) tall tower located in Erie, CO and covering areas from Boulder, Denver, Longmont, Fort Collins and Greeley. Enhancements in CO2, CO and destruction of ozone mainly reflect emissions from traffic. Methane enhancements however are clearly correlated with nearby point sources (landfill, feedlot, natural gas compressor ...) or with larger scale air masses advected from the NE Colorado, where oil and gas drilling operations are widespread. The multiple species analysis (hydrocarbons, CFCs, HFCs) of the air samples collected along the way bring insightful information about the methane sources at play. We will present results of the analysis and interpretation of the Hybrid Lab Front Range Study and conclude with perspectives

Intense, pulsed, ion-diode sources and their application to mirror machines

International Nuclear Information System (INIS)

Prono, D.S.; Shearer, J.W.; Briggs, R.J.

1975-01-01

Startup conditions for future mirror fusion experiments require a rapidly formed target plasma of approximately 0.5 coulomb of ions with energy of 50 to 100 keV. Theory suggests that very intense ion-flux emission satisfying these requirements can be extracted from a pulsed ion diode. Developing such sources would be an ideal CTR application of the high-power, single-shot capability of pulsed power technology. Recent experimental results are reviewed in which approximately 2 kA/cm 2 of D + at approximately 50 keV was extracted. In the experiment, an intense relativistic electron beam undergoes many transits through a solid but range-thin anode foil. With each transit the electrons lose energy, causing their trajectories to collapse toward the anode surface. In so doing, the increased space charge extracts an intense ion flux from the anode foil's plasma. Observations are reported on the importance of diode stability. The general agreement between theoretical scaling laws and experimental results are also presented

Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

Science.gov (United States)

Zhao, H. W.; Sun, L. T.; Guo, J. W.; Lu, W.; Xie, D. Z.; Hitz, D.; Zhang, X. Z.; Yang, Y.

2017-09-01

The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24-28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of 40Ar+ and 129Xe26+ have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL), China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24 +18 GHz ) heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

Y-Source Boost DC/DC Converter for Distributed Generation

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

2015-01-01

This paper introduces a versatile Y-source boost dc/dc converter intended for distributed power generation, where high gain is often demanded. The proposed converter uses a Y-source impedance network realized with a tightly coupled three-winding inductor for high voltage boosting that is presently...

A Novel Intensive Distribution Logistics Network Design and Profit Allocation Problem considering Sharing Economy

Directory of Open Access Journals (Sweden)

Mi Gan

2018-01-01

Full Text Available The rapid growth of logistics distribution highlights the problems including the imperfect infrastructure of logistics distribution network, the serious shortage of distribution capacity of each individual enterprise, and the high cost of distribution in China. While the development of sharing economy makes it possible to achieve the integration of whole social logistic resources, big data technology can grasp customer’s logistics demand accurately on the basis of analyzing the customer’s logistics distribution preference, which contributes to the integration and optimization of the whole logistics resources. This paper proposes a kind of intensive distribution logistics network considering sharing economy, which assumes that all the social logistics suppliers build a strategic alliance, and individual idle logistics resources are also used to deal with distribution needs. Analyzing customer shopping behavior by the big data technology to determine customer’s logistics preference on the basis of dividing the customer’s logistics preference into high speed, low cost, and low pollution and then constructing the corresponding objective function model according to different logistics preferences, we obtain the intensive distribution logistics network model and solve it with heuristic algorithm. Furthermore, this paper analyzes the mechanism of interest distribution of the participants in the distribution network and puts forward an improved interval Shapley value method considering both satisfaction and contribution, with case verifying the feasibility and effectiveness of the model. The results showed that, compared with the traditional Shapley method, distribution coefficient calculated by the improved model could be fairer, improve stakeholder satisfaction, and promote the sustainable development of the alliance as well.

Supply and distribution for γ-ray sources

International Nuclear Information System (INIS)

Yamamoto, Takeo

1997-01-01

Japan Atomic energy Research Institute (JAERI) is the only facility to supply and distribute radioisotopes (RI) in Japan. The γ-ray sources for medical use are 192 Ir and 169 Yb for non-destructive examination and 192 Ir, 198 Au and 153 Gd for clinical use. All of these demands in Japan are supplied with domestic products at present. Meanwhile, γ-ray sources imported are 60 Co sources for medical and industrial uses including sterilization of medical instruments, 137 Cs for irradiation to blood and 241 Am for industrial measurements. The major overseas suppliers are Nordion International Inc. and Amersham International plc. RI products on the market are divided into two groups; one is the primary products which are supplied in liquid or solid after chemical or physical treatments of radioactive materials obtained from reactor and the other is the secondary product which is a final product after various processing. Generally these secondary products are used in practice. In Japan, both of the domestic and imported products are supplied to the users via JRIA (Japan Radioisotope Association). The association participates in the sales and the distributions of the secondary products and also in the processings of the primary ones to their sealed sources. Furthermore, stable supplying systems for these products are almost established according to the half life of each nuclide only if there is no accident in the reactor. (M.N.)

Neutron production enhancements for the Intense Pulsed Neutron Source.

Energy Technology Data Exchange (ETDEWEB)

Iverson, E. B.

1999-01-04

The Intense Pulsed Neutron Source (IPNS) was the first high energy spallation neutron source in the US dedicated to materials research. It has operated for sixteen years, and in that time has had a very prolific record concerning the development of new target and moderator systems for pulsed spallation sources. IPNS supports a very productive user program on its thirteen instruments, which are oversubscribed by more than two times, meanwhile having an excellent overall reliability of 95%. Although the proton beam power is relatively low at 7 kW, the target and moderator systems are very efficient. The typical beam power which gives an equivalent flux for long-wavelength neutrons is about 60 kW, due to the use of a uranium target and liquid and solid methane moderators, precluded at some sources due to a higher accelerator power. The development of new target and moderator systems is by no means stagnant at IPNS. They are presently considering numerous enhancements to the target and moderators that offer prospects for increasing the useful neutron production by substantial factors. Many of these enhancements could be combined, although their combined benefit has not yet been well established. Meanwhile, IPNS is embarking on a coherent program of study concerning these improvements and their possible combination and implementation. Moreover, any improvements accomplished at IPNS would immediately increase the performance of IPNS instruments.

Neutron production enhancements for the Intense Pulsed Neutron Source

International Nuclear Information System (INIS)

Iverson, E. B.

1999-01-01

The Intense Pulsed Neutron Source (IPNS) was the first high energy spallation neutron source in the US dedicated to materials research. It has operated for sixteen years, and in that time has had a very prolific record concerning the development of new target and moderator systems for pulsed spallation sources. IPNS supports a very productive user program on its thirteen instruments, which are oversubscribed by more than two times, meanwhile having an excellent overall reliability of 95%. Although the proton beam power is relatively low at 7 kW, the target and moderator systems are very efficient. The typical beam power which gives an equivalent flux for long-wavelength neutrons is about 60 kW, due to the use of a uranium target and liquid and solid methane moderators, precluded at some sources due to a higher accelerator power. The development of new target and moderator systems is by no means stagnant at IPNS. They are presently considering numerous enhancements to the target and moderators that offer prospects for increasing the useful neutron production by substantial factors. Many of these enhancements could be combined, although their combined benefit has not yet been well established. Meanwhile, IPNS is embarking on a coherent program of study concerning these improvements and their possible combination and implementation. Moreover, any improvements accomplished at IPNS would immediately increase the performance of IPNS instruments

Report from the NSLS workshop: Sources and applications of high intensity uv-vuv light

Energy Technology Data Exchange (ETDEWEB)

Johnson, E.D.; Hastings, J.B. (eds.)

1990-01-01

A workshop was held to evaluate sources and applications of high intensity, ultra violet (UV) radiation for biological, chemical, and materials sciences. The proposed sources are a UV free electron laser (FEL) driven by a high brightness linac and undulators in long, straight sections of a specially designed low energy (400 MeV) storage ring. These two distinct types of sources will provide a broad range of scientific opportunities that were discussed in detail during the workshop.

Report from the NSLS workshop: Sources and applications of high intensity uv-vuv light

Energy Technology Data Exchange (ETDEWEB)

Johnson, E.D.; Hastings, J.B. [eds.

1990-12-31

A workshop was held to evaluate sources and applications of high intensity, ultra violet (UV) radiation for biological, chemical, and materials sciences. The proposed sources are a UV free electron laser (FEL) driven by a high brightness linac and undulators in long, straight sections of a specially designed low energy (400 MeV) storage ring. These two distinct types of sources will provide a broad range of scientific opportunities that were discussed in detail during the workshop.

Report from the NSLS workshop: Sources and applications of high intensity uv-vuv light

International Nuclear Information System (INIS)

Johnson, E.D.; Hastings, J.B.

1990-01-01

A workshop was held to evaluate sources and applications of high intensity, ultra violet (UV) radiation for biological, chemical, and materials sciences. The proposed sources are a UV free electron laser (FEL) driven by a high brightness linac and undulators in long, straight sections of a specially designed low energy (400 MeV) storage ring. These two distinct types of sources will provide a broad range of scientific opportunities that were discussed in detail during the workshop

Conceptual design of a high-intensity positron source for the Advanced Neutron Source

International Nuclear Information System (INIS)

Hulett, L.D.; Eberle, C.C.

1994-12-01

The Advanced Neutron Source (ANS) is a planned new basic and applied research facility based on a powerful steady-state research reactor that provides neutrons for measurements and experiments in the fields of materials science and engineering, biology, chemistry, materials analysis, and nuclear science. The useful neutron flux will be at least five times more than is available in the world's best existing reactor facility. Construction of the ANS provides a unique opportunity to build a positron spectroscopy facility (PSF) with very-high-intensity beams based on the radioactive decay of a positron-generating isotope. The estimated maximum beam current is 1000 to 5000 times higher than that available at the world's best existing positron research facility. Such an improvement in beam capability, coupled with complementary detectors, will reduce experiment durations from months to less than one hour while simultaneously improving output resolution. This facility will remove the existing barriers to the routine use of positron-based analytical techniques and will be a giant step toward realization of the full potential of the application of positron spectroscopy to materials science. The ANS PSF is based on a batch cycle process using 64 Cu isotope as the positron emitter and represents the status of the design at the end of last year. Recent work not included in this report, has led to a proposal for placing the laboratory space for the positron experiments outside the ANS containment; however, the design of the positron source is not changed by that relocation. Hydraulic and pneumatic flight tubes transport the source material between the reactor and the positron source where the beam is generated and conditioned. The beam is then transported through a beam pipe to one of several available detectors. The design presented here includes all systems necessary to support the positron source, but the beam pipe and detectors have not been addressed yet

Distributed modelling of shallow landslides triggered by intense rainfall

Directory of Open Access Journals (Sweden)

G. B. Crosta

2003-01-01

Full Text Available Hazard assessment of shallow landslides represents an important aspect of land management in mountainous areas. Among all the methods proposed in the literature, physically based methods are the only ones that explicitly includes the dynamic factors that control landslide triggering (rainfall pattern, land-use. For this reason, they allow forecasting both the temporal and the spatial distribution of shallow landslides. Physically based methods for shallow landslides are based on the coupling of the infinite slope stability analysis with hydrological models. Three different grid-based distributed hydrological models are presented in this paper: a steady state model, a transient "piston-flow" wetting front model, and a transient diffusive model. A comparative test of these models was performed to simulate landslide occurred during a rainfall event (27–28 June 1997 that triggered hundreds of shallow landslides within Lecco province (central Southern Alps, Italy. In order to test the potential for a completely distributed model for rainfall-triggered landslides, radar detected rainfall intensity has been used. A new procedure for quantitative evaluation of distributed model performance is presented and used in this paper. The diffusive model results in the best model for the simulation of shallow landslide triggering after a rainfall event like the one that we have analysed. Finally, radar data available for the June 1997 event permitted greatly improving the simulation. In particular, radar data allowed to explain the non-uniform distribution of landslides within the study area.

Impact of distribution intensity on perceived quality, brand awareness and brand loyality - structural model

Directory of Open Access Journals (Sweden)

Ivan-Damir Anić

2008-12-01

Full Text Available The purpose of this empirical study was to determine the impacts of distribution intensity on perceived quality and brand awareness, and to analyze the effects of perceived quality and brand awareness on brand loyalty. A structural equation model was used to identify the size and the direction of proposed relationships. The model was tested on a sample of 956 students using three brand categories in the manufacturing industry and three brand categories in the service industry. The proposed hypotheses were supported by the model. The results show that distribution intensity is positively related to perceived quality and brand awareness. Moreover, perceived quality and brand awareness were shown to be significant and positive predictors of brand loyalty. Managerial implications are discussed in the paper. The findings of this study could be of special interests to managers, professionals and those doing research in the field of distribution and brand management.

Sediment sources and their Distribution in Chwaka Bay, Zanzibar ...

African Journals Online (AJOL)

This work establishes sediment sources, character and their distribution in Chwaka Bay using (i) stable isotopes compositions of organic carbon (OC) and nitrogen, (ii) contents of OC, nitrogen and CaCO3, (iii) C/N ratios, (iv) distribution of sediment mean grain size and sorting, and (v) thickness of unconsolidated sediments.

Distribution patterns and sources of metals and PAHs in an intensely urbanized area: The Acerra-Pomigliano-Marigliano conurbation (Italy)

Science.gov (United States)

Albanese, Stefano; Lima, Annamaria; Rezza, Carmela; Ferullo, Giampiero; De Vivo, Benedetto; Chen, Wei; Qi, Shihua

2014-05-01

agricultural intensive land use. PAHs distribution pattern showed anomalous values across the whole study area. Especially, Benzo[a]pyrene values exceeds the trigger limits established by the Italian Environmental law (D.Lgs. 152/2006) in most of the analyzed soils and the diagnostic ratios calculated among several PAHs compounds suggested that the biomass burning in the rural sector of the study area could be a relevant source of pollution. The palm oil fuelled power plant in the northern sector of Acerra could not be excluded as a source of PAHs in the environment. [1] Albanese et al (2007) JGE 93, 21-34. [2] Cicchella et al (2008) GEEA 8 (1), 19-29. [3] De Vivo et al (2006) Aracne Editrice, Roma. 324 pp.

Focusing and transport of high-intensity multi-MeV proton bunches from a compact laser-driven source

Science.gov (United States)

Busold, S.; Schumacher, D.; Deppert, O.; Brabetz, C.; Frydrych, S.; Kroll, F.; Joost, M.; Al-Omari, H.; Blažević, A.; Zielbauer, B.; Hofmann, I.; Bagnoud, V.; Cowan, T. E.; Roth, M.

2013-10-01

Laser ion acceleration provides for compact, high-intensity ion sources in the multi-MeV range. Using a pulsed high-field solenoid, for the first time high-intensity laser-accelerated proton bunches could be selected from the continuous exponential spectrum and delivered to large distances, containing more than 109 particles in a narrow energy interval around a central energy of 9.4 MeV and showing ≤30mrad envelope divergence. The bunches of only a few nanoseconds bunch duration were characterized 2.2 m behind the laser-plasma source with respect to arrival time, energy width, and intensity as well as spatial and temporal bunch profile.

Note: A new design for a low-temperature high-intensity helium beam source

Science.gov (United States)

Lechner, B. A. J.; Hedgeland, H.; Allison, W.; Ellis, J.; Jardine, A. P.

2013-02-01

A high-intensity supersonic beam source is a key component of any atom scattering instrument, affecting the sensitivity and energy resolution of the experiment. We present a new design for a source which can operate at temperatures as low as 11.8 K, corresponding to a beam energy of 2.5 meV. The new source improves the resolution of the Cambridge helium spin-echo spectrometer by a factor of 5.5, thus extending the accessible timescales into the nanosecond range. We describe the design of the new source and discuss experiments characterizing its performance. Spin-echo measurements of benzene/Cu(100) illustrate its merit in the study of a typical slow-moving molecular adsorbate species.

Gasdynamic measurements for the LASL intense neutron source

International Nuclear Information System (INIS)

Johnston, S.C.

1978-02-01

Measurements made on a two-dimensional simulation of the Los Alamos Scientific Laboratory (LASL) Intense Neutron Source (INS) experiment are discussed. The purpose of this work was to characterize the supersonic INS channel flow under conditions of large amounts of energy deposition. Nozzle channel wall pressure measurements, cold flow leakage rates, vacuum channel pressure and Mach number, leakage flow rates with mass addition to and momentum extraction from the main flow, and flow visualization photographs are given. Energy addition up to thirty percent of the theoretical maximum was achieved via mass addition to and momentum extraction from the main channel flow. In this range, both a weak and strong regime for leakage flow were identified. These regimes differed by about twenty percent in leakage flow rates

Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

Directory of Open Access Journals (Sweden)

H. W. Zhao

2017-09-01

Full Text Available The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24–28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of ^{40}Ar^{12+} and ^{129}Xe^{26+} have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL, China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24+18  GHz heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

The effect of energy distribution of external source on source multiplication in fast assemblies

International Nuclear Information System (INIS)

Karam, R.A.; Vakilian, M.

1976-02-01

The essence of this study is the effect of energy distribution of a source on the detection rate as a function of K effective in fast assemblies. This effectiveness, as a function of K was studied in a fission chamber, using the ABN cross-section set and Mach 1 code. It was found that with a source which has a fission spectrum, the reciprocal count rate versus mass relationship is linear down to K effective 0.59. For a thermal source, the linearity was never achieved. (author)

Multinational ownership and R&D intensity: The role of external knowledge sources and spillovers

OpenAIRE

De Beule, Filip; Van Beveren, Ilke

2011-01-01

This paper analyzes the drivers of multinational affiliates' R&D intensity, using a unique dataset based on the fourth Community Innovation Survey for Belgium. Specifically, we investigate the role of foreign affiliates' local (host country) embeddedness and of host country spillovers on foreign affiliates' research efforts. Our findings show that foreign affiliates who are able to tap into local knowledge sources demonstrate a higher research intensity, compared to firms lacking such access....

Generation of initial kinetic distributions for simulation of long-pulse charged particle beams with high space-charge intensity

Directory of Open Access Journals (Sweden)

Steven M. Lund

2009-11-01

Full Text Available Self-consistent Vlasov-Poisson simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel—both in terms of low-order rms (envelope properties as well as the higher-order phase-space structure. Here, we first review broad classes of kinetic distributions commonly in use as initial Vlasov distributions in simulations of unbunched or weakly bunched beams with intense space-charge fields including the following: the Kapchinskij-Vladimirskij (KV equilibrium, continuous-focusing equilibria with specific detailed examples, and various nonequilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of standard accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial kinetic distributions are constructed using transformations that preserve linear focusing, single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for noncontinuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulations that more precisely probe intrinsic stability properties and machine performance.

Need for an intense polarized source at LAMPF. Report on a workshop held at Los Alamos, November 9, 1983

International Nuclear Information System (INIS)

McNaughton, M.W.; Silbar, R.R.; van Dyck, O.B.

1984-04-01

We report on a workshop to consider the need for an intense polarized source at LAMPF. The primary justification for such a source comes from the nucleon-nucleon program; neutron-proton scattering is seriously underdetermined and cannot be satisfactorily completed without such an intense source. Further justification comes from nuclear (vector n,p) and (vector p, vector n) reactions, as well as from traditional nuclear physics at the LAMPF high resolution spectrometer. We recommend that a source capable of providing a few μA beam on target be built as soon as possible

Radiation Source Mapping with Bayesian Inverse Methods

Science.gov (United States)

Hykes, Joshua Michael

We present a method to map the spectral and spatial distributions of radioactive sources using a small number of detectors. Locating and identifying radioactive materials is important for border monitoring, accounting for special nuclear material in processing facilities, and in clean-up operations. Most methods to analyze these problems make restrictive assumptions about the distribution of the source. In contrast, the source-mapping method presented here allows an arbitrary three-dimensional distribution in space and a flexible group and gamma peak distribution in energy. To apply the method, the system's geometry and materials must be known. A probabilistic Bayesian approach is used to solve the resulting inverse problem (IP) since the system of equations is ill-posed. The probabilistic approach also provides estimates of the confidence in the final source map prediction. A set of adjoint flux, discrete ordinates solutions, obtained in this work by the Denovo code, are required to efficiently compute detector responses from a candidate source distribution. These adjoint fluxes are then used to form the linear model to map the state space to the response space. The test for the method is simultaneously locating a set of 137Cs and 60Co gamma sources in an empty room. This test problem is solved using synthetic measurements generated by a Monte Carlo (MCNP) model and using experimental measurements that we collected for this purpose. With the synthetic data, the predicted source distributions identified the locations of the sources to within tens of centimeters, in a room with an approximately four-by-four meter floor plan. Most of the predicted source intensities were within a factor of ten of their true value. The chi-square value of the predicted source was within a factor of five from the expected value based on the number of measurements employed. With a favorable uniform initial guess, the predicted source map was nearly identical to the true distribution

Optimisation of intense X-ray sources of Z-pinch type connected to the high intensity current generator SPHINX

International Nuclear Information System (INIS)

Calamy, H.; Lassalle, F.; Grunenwald, J.; Zucchini, F.

2010-01-01

A new source of intense X-rays in the spectral range of the keV has been designed in the CEA facilities at Gramat (France). This Z-pinch source is based on the implosion of a cylinder of matter that has been ionized by the Lorentz force generated by the injection in the cylinder of an intense current pulse delivered by a HPP (High Pulsed Powers) generator named SPHINX. The cylinder of matter is made up of a few hundreds of thin metal wires (tungsten or aluminium) whose diameter is less than a few tenths of μm. The SPHINX generator is based on the LTD (Linear Transformer Driver) technology. SPHINX stores an energy of 2.2 MJ and delivers a current of 8 MA over a time of 1 μs. SPHINX does not use any technology of time compression, it is a robust, compact machine with reduced maintenance but the price to pay for this simplification is to maintain a high axial homogeneity of the implosion during the initiation phase, it means the pulse time of 1μs. The preliminary experiments that have been performed give the following results: -) for a tungsten cylinder (X ray 1 keV): 28 kJ, 0.6 TW and 25 ns

Intense Terahertz Sources for 2D Spectroscopy

DEFF Research Database (Denmark)

Pedersen, Pernille Klarskov

in a molecular dynamics (MD) simulation. With this THz induced nonlinear responses and mode couplings in CsI and sucrose are investigated for increasing field strengths, and it is found that these occur for sucrose when the field strength is in the MV/cm range. THz sources based on LiNbO3, DAST, DSTMS and 2...... observed having a Gaussian beam profile. In addition to the intense THz pulses focused in free-space in order to achieve the highest possible field strength, it is shown that resonant microslit arrays can be used to enhance the THz field, and with the possibility of mounting crystalline samples inside...... the metallic slits, this is proposed as a combined spectroscopy system for investigating high-field phenomena. With a carefully optimized design, the slit resonance can be coupled to the lattice modes of the array structure to achieve a field enhancement of more than 35 times, which is approximately 60 % more...

Minimum-phase distribution of cosmic source brightness

International Nuclear Information System (INIS)

Gal'chenko, A.A.; Malov, I.F.; Mogil'nitskaya, L.F.; Frolov, V.A.

1984-01-01

Minimum-phase distributions of brightness (profiles) for cosmic radio sources 3C 144 (the wave lambda=21 cm), 3C 338 (lambda=3.5 m), and 3C 353 (labda=31.3 cm and 3.5 m) are obtained. A real possibility for the profile recovery from module fragments of its Fourier-image is shown

The high intensity {gamma}-ray source (HI{gamma}S) and recent results

Energy Technology Data Exchange (ETDEWEB)

Tonchev, A.P. [Duke University and TUNL, Triangle University Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 0308 (United States)]. E-mail: tonchev@tunl.duke.edu; Boswell, M. [University of North Carolina at Chapel Hill and TUNL, Chapel Hill, NC 27599 (United States); Howell, C.R. [Duke University and TUNL, Triangle University Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 0308 (United States); Karwowski, H.J. [University of North Carolina at Chapel Hill and TUNL, Chapel Hill, NC 27599 (United States); Kelley, J.H. [North Carolina State University and TUNL, Raleigh, NC 27695 (United States); Tornow, W. [Duke University and TUNL, Triangle University Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 0308 (United States); Wu, Y.K. [Duke University and Duke Free Electron Laser Laboratory, Durham, NC 27708-0319 (United States)

2005-12-15

The high intensity {gamma}-ray source (HI{gamma}S) utilizes intra-cavity backscattering of free electron laser photons from the Duke electron storage ring to produce a unique monoenergetic beam of high-flux {gamma}-rays with high polarization and selectable energy resolution. At present, {gamma}-ray beams with energies from 2 to 58 MeV are available with intensities as high as 10{sup 5}-5 x 10{sup 6} {gamma}/s, energy spreads of 3% or better, and nearly 100% linear polarization. The quality and intensity of the {gamma}-ray beams at HI{gamma}S are responsible for the unprecedented performance of this facility in a broad range of research programs in nuclear structure, nuclear astrophysics and nuclear applications. Recent results from excitation of isomeric states in ({gamma}, n) reactions and parity assignments of dipole states determined via the ({gamma}, {gamma}') reaction are presented.

Focusing and transport of high-intensity multi-MeV proton bunches from a compact laser-driven source

Directory of Open Access Journals (Sweden)

S. Busold

2013-10-01

Full Text Available Laser ion acceleration provides for compact, high-intensity ion sources in the multi-MeV range. Using a pulsed high-field solenoid, for the first time high-intensity laser-accelerated proton bunches could be selected from the continuous exponential spectrum and delivered to large distances, containing more than 10^{9} particles in a narrow energy interval around a central energy of 9.4 MeV and showing ≤30  mrad envelope divergence. The bunches of only a few nanoseconds bunch duration were characterized 2.2 m behind the laser-plasma source with respect to arrival time, energy width, and intensity as well as spatial and temporal bunch profile.

Preliminary tests of a second harmonic rf system for the intense pulsed neutron source synchrotron

International Nuclear Information System (INIS)

Norem, J.; Brandeberry, F.

1983-01-01

The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2 to 2.5 x 10 12 protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at approx. 3 x 10 12 ppp, depending somewhat on the available aperture. Accelerator improvements are being directed at (1) increasing beam intensities for neutron science, (2) lowering acceleration losses to minimize activation, and (3) gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. We are now proposing a third cavity for the RF system which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses by providing more RF voltage at maximum acceleration. This paper presents an outline of the expected benefits together with recent results obtained during low energy operation with one of the two existing cavities operating at the second harmonic

Multiple LDPC decoding for distributed source coding and video coding

DEFF Research Database (Denmark)

Forchhammer, Søren; Luong, Huynh Van; Huang, Xin

2011-01-01

Distributed source coding (DSC) is a coding paradigm for systems which fully or partly exploit the source statistics at the decoder to reduce the computational burden at the encoder. Distributed video coding (DVC) is one example. This paper considers the use of Low Density Parity Check Accumulate...... (LDPCA) codes in a DSC scheme with feed-back. To improve the LDPC coding performance in the context of DSC and DVC, while retaining short encoder blocks, this paper proposes multiple parallel LDPC decoding. The proposed scheme passes soft information between decoders to enhance performance. Experimental...

Accelerator-driven neutron sources for materials research

International Nuclear Information System (INIS)

Jameson, R.A.

1990-01-01

Particle accelerators are important tools for materials research and production. Advances in high-intensity linear accelerator technology make it possible to consider enhanced neutron sources for fusion material studies or as a source of spallation neutrons. Energy variability, uniformity of target dose distribution, target bombardment from multiple directions, time-scheduled dose patterns, and other features can be provided, opening new experimental opportunities. New designs have also been used to ensure hands-on maintenance on the accelerator in these factory-type facilities. Designs suitable for proposals such as the Japanese Energy-Selective Intense Neutron Source, and the international Fusion Materials Irradiation Facility are discussed

A method to analyze "source-sink" structure of non-point source pollution based on remote sensing technology.

Science.gov (United States)

Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

2013-11-01

With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the "source-sink" theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of "source" of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km(2) in 2008, and the "sink" was 172.06 km(2). The "source" of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the "sink" was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of "source" gets weaker along with the distance from the seas boundary increase, while "sink" gets stronger. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bisphenol analogues in surface water and sediment from the shallow Chinese freshwater lakes: Occurrence, distribution, source apportionment, and ecological and human health risk.

Science.gov (United States)

Yan, Zhengyu; Liu, Yanhua; Yan, Kun; Wu, Shengmin; Han, Zhihua; Guo, Ruixin; Chen, Meihong; Yang, Qiulian; Zhang, Shenghu; Chen, Jianqiu

2017-10-01

Compared to Bisphenol A (BPA), current knowledge on the spatial distribution, potential sources and environmental risk assessment of other bisphenol analogues (BPs) remains limited. The occurrence, distribution and sources of seven BPs were investigated in the surface water and sediment from Taihu Lake and Luoma Lake, which are the Chinese shallow freshwater lakes. Because there are many industries and living areas around Taihu Lake, the total concentrations of ∑BPs were much higher than that in Luoma Lake, which is away from the industry-intensive areas. For the two lakes, BPA was still the dominant BPs in both surface water and sediment, followed by BPF and BPS. The spatial distribution and principal component analysis showed that BPs in Luoma Lake was relatively homogeneous and the potential sources were relatively simple than that in Taihu Lake. The spatial distribution of BPs in sediment of Taihu Lake indicated that ∑BPs positively correlated with the TOC content. For both Taihu Lake and Luoma Lake, the risk assessment at the sampling sites showed that no high risk in surface water and sediment (RQ t  < 1.0, and EEQ t  < 1.0 ng E 2 /L). Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of deformed intensity distributions for on-line modification of image-guided IMRT to account for interfractional anatomic changes

International Nuclear Information System (INIS)

Mohan, Radhe; Zhang Xiaodong; Wang He; Kang Yixiu; Wang Xiaochun; Liu, Helen; Ang, K.; Kuban, Deborah; Dong Lei

2005-01-01

Purpose: Recent imaging studies have demonstrated that there can be significant changes in anatomy from day to day and over the course of radiotherapy as a result of daily positioning uncertainties and physiologic and clinical factors. There are a number of strategies to minimize such changes, reduce their impact, or correct for them. Measures to date have included improved immobilization of external and internal anatomy or adjustment of positions based on portal or ultrasound images. Perhaps the most accurate way is to use CT image-guided radiotherapy, for which the possibilities range from simple correction of setup based on daily CT images to on-line near real-time intensity modulated radiotherapy (IMRT) replanning. In addition, there are numerous intermediate possibilities. In this paper, we report the development of one such intermediate method that takes into account anatomic changes by deforming the intensity distributions of each beam based on deformations of anatomy as seen in the beam's-eye-view. Methods and materials: The intensity distribution deformations are computed based on anatomy deformations discerned from the changes in the current image relative to a reference image (e.g., the pretreatment CT scan). First, a reference IMRT plan is generated based on the reference CT image. A new CT image is acquired using an in-room CT for every fraction. The anatomic structure contours are obtained for the new image. (For this article, these contours were manually drawn. When image guided IMRT methods are implemented, anatomic structure contours on subsequent images will likely be obtained with automatic or semiautomatic means. This could be achieved by, for example, first deforming the original CT image to match today's image, and then using the same deformation transformation to map original contours to today's image.) The reference intensity distributions for each beam are then deformed so that the projected geometric relationship within the beam

Magnitude and Spatial Distribution of Impact Intensity Under the Foot Relates to Initial Foot Contact Pattern.

Science.gov (United States)

Breine, Bastiaan; Malcolm, Philippe; Segers, Veerle; Gerlo, Joeri; Derie, Rud; Pataky, Todd; Frederick, Edward C; De Clercq, Dirk

2017-12-01

In running, foot contact patterns (rear-, mid-, or forefoot contact) influence impact intensity and initial ankle and foot kinematics. The aim of the study was to compare impact intensity and its spatial distribution under the foot between different foot contact patterns. Forty-nine subjects ran at 3.2 m·s -1 over a level runway while ground reaction forces (GRF) and shoe-surface pressures were recorded and foot contact pattern was determined. A 4-zone footmask (forefoot, midfoot, medial and lateral rearfoot) assessed the spatial distribution of the vertical GRF under the foot. We calculated peak vertical instantaneous loading rate of the GRF (VILR) per foot zone as the impact intensity measure. Midfoot contact patterns were shown to have the lowest, and atypical rearfoot contact patterns the highest impact intensities, respectively. The greatest local impact intensity was mainly situated under the rear- and midfoot for the typical rearfoot contact patterns, under the midfoot for the atypical rearfoot contact patterns, and under the mid- and forefoot for the midfoot contact patterns. These findings indicate that different foot contact patterns could benefit from cushioning in different shoe zones.

Distributed Remote Vector Gaussian Source Coding with Covariance Distortion Constraints

DEFF Research Database (Denmark)

Zahedi, Adel; Østergaard, Jan; Jensen, Søren Holdt

2014-01-01

In this paper, we consider a distributed remote source coding problem, where a sequence of observations of source vectors is available at the encoder. The problem is to specify the optimal rate for encoding the observations subject to a covariance matrix distortion constraint and in the presence...

Investigation of an He-Ne laser generating a beam with a ring-shaped intensity distribution

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, I I; Troitskii, IU V; Iakushkin, S V

1987-02-01

The paper examines an He-Ne laser regime with the simultaneous generation of TEM(01) and TEM(10) modes, forming a beam with a ring-shaped intensity distribution with total suppression of the TEM(00) mode. The ratio of the intensity at the ring crest to the intensity at the axis reached a value of 200 and was limited by scattering in the optical components of the resonator. A regime of mutual frequency locking of the TEM(01) and TEM(10) modes was achieved with total spatial coherence of the ring-shaped beam. 14 references.

Pu and 137Cs in the Yangtze River estuary sediments: distribution and source identification.

Science.gov (United States)

Liu, Zhiyong; Zheng, Jian; Pan, Shaoming; Dong, Wei; Yamada, Masatoshi; Aono, Tatsuo; Guo, Qiuju

2011-03-01

Pu isotopes and (137)Cs were analyzed using sector field ICP-MS and γ spectrometry, respectively, in surface sediment and core sediment samples from the Yangtze River estuary. (239+240)Pu activity and (240)Pu/(239)Pu atom ratios (>0.18) shows a generally increasing trend from land to sea and from north to south in the estuary. This spatial distribution pattern indicates that the Pacific Proving Grounds (PPG) source Pu transported by ocean currents was intensively scavenged into the suspended sediment under favorable conditions, and mixed with riverine sediment as the water circulated in the estuary. This process is the main control for the distribution of Pu in the estuary. Moreover, Pu is also an important indicator for monitoring the changes of environmental radioactivity in the estuary as the river basin is currently the site of extensive human activities and the sea level is rising because of global climate changes. For core sediment samples the maximum peak of (239+240)Pu activity was observed at a depth of 172 cm. The sedimentation rate was estimated on the basis of the Pu maximum deposition peak in 1963-1964 to be 4.1 cm/a. The contributions of the PPG close-in fallout Pu (44%) and the riverine Pu (45%) in Yangtze River estuary sediments are equally important for the total Pu deposition in the estuary, which challenges the current hypothesis that the riverine Pu input was the major source of Pu budget in this area.

Representation of chromatic distribution for lighting system

Science.gov (United States)

Rossi, Maurizio; Musante, Fulvio

2015-01-01

For the luminaire manufacturer, the measurement of the lighting intensity distribution (LID) emitted by lighting fixture is based on photometry. So light is measured as an achromatic value of intensity and there is no the possibility to discriminate the measurement of white vs. colored light. At the Laboratorio Luce of Politecnico di Milano a new instrument for the measurement of spectral radiant intensities distribution for lighting system has been built: the goniospectra- radiometer. This new measuring tool is based on a traditional mirror gonio-photometer with a CCD spectraradiometer controlled by a PC. Beside the traditional representation of photometric distribution we have introduced a new representation where, in addition to the information about the distribution of luminous intensity in space, new details about the chromaticity characteristic of the light sources have been implemented. Some of the results of this research have been applied in developing and testing a new line of lighting system "My White Light" (the research project "Light, Environment and Humans" funded in the Italian Lombardy region Metadistretti Design Research Program involving Politecnico di Milano, Artemide, Danese, and some other SME of the Lighting Design district), giving scientific notions and applicative in order to support the assumption that colored light sources can be used for the realization of interior luminaries that, other than just have low power consumption and long life, may positively affect the mood of people.

16 CFR Table 4 to Part 1512 - Relative Energy Distribution of Sources

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Relative Energy Distribution of Sources 4... SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Table 4 Table 4 to Part 1512—Relative Energy Distribution of Sources Wave length (nanometers) Relative energy 380 9.79 390 12.09 400 14.71 410 17.68 420 21...

Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL.

Science.gov (United States)

Zhao, H W; Sun, L T; Zhang, X Z; Guo, X H; Cao, Y; Lu, W; Zhang, Z M; Yuan, P; Song, M T; Zhao, H Y; Jin, T; Shang, Y; Zhan, W L; Wei, B W; Xie, D Z

2008-02-01

There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

Determination of Noise Level and Its Sources in the Neonatal Intensive Care Unit and Neonatal Ward

Directory of Open Access Journals (Sweden)

Mahdi Jahangir Blourchian

2015-12-01

Full Text Available Background: In Neonatal intensive care units (NICU different sound intensities and frequencies are produced from different sources, which may exert undesirable physiological effects on the infants. The aim of this study was to determine the noise level and its sources in the NICU and neonatal ward of Al-Zahra Hospital of Rasht, Iran. Methods: In this descriptive cross-sectional study, the intensity of the sounds generated by the internal and external sources in the NICU and neonatal ward was measured using a sound level meter device. The sound produced by each of the sources was individually calculated. Data were analyzed performing descriptive and analytical statistics, using SPSS version 19. Results: The mean noise levels in six rooms and a hallway during morning, afternoon and night shifts with the electromechanical devices turned on were 61.67±4.5, 61.32±4.32 and 60.71±4.56 dB, respectively. Moreover, with the devices tuned off the mean noise levels during morning, afternoon and evening shifts were 64.97±2.6, 60.6±1.29 and 57.91±4.73 dB, respectively. The differences between the mean noise levels in the neonatal wards (standard noise level=45 dB during each shift with the electromechanical devices turned on and off were statistically significant (P=0.002 and P

Novel neutralized-beam intense neutron source for fusion technology development

International Nuclear Information System (INIS)

Osher, J.E.; Perkins, L.J.

1983-01-01

We describe a neutralized-beam intense neutron source (NBINS) as a relevant application of fusion technology for the type of high-current ion sources and neutral beamlines now being developed for heating and fueling of magnetic-fusion-energy confinement systems. This near-term application would support parallel development of highly reliable steady-state higher-voltage neutral D 0 and T 0 beams and provide a relatively inexpensive source of fusion neutrons for materials testing at up to reactor-like wall conditions. Beam-target examples described incude a 50-A mixed D-T total (ions plus neutrals) space-charge-neutralized beam at 120 keV incident on a liquid Li drive-in target, or a 50-A T 0 + T + space-charge-neutralized beam incident on either a LiD or gas D 2 target with calculated 14-MeV neutron yields of 2 x 10 15 /s, 7 x 10 15 /s, or 1.6 x 10 16 /s, respectively. The severe local heat loading on the target surface is expected to limit the allowed beam focus and minimum target size to greater than or equal to 25 cm 2

Intensity Distribution of the Three-Wave Diffraction from Dislocation Epitaxial Layers in the Reciprocal Space

Science.gov (United States)

Kyutt, R. N.

2018-04-01

The three-wave X-ray diffraction in strongly disordered epitaxial layers of GaN and ZnO is experimentally investigated. The charts of the intensity distribution in the reciprocal space are plotted in coordinates q θ and q ϕ for the most intensive three-wave combination (1010)/(1011) by means of subsequent θ- and ϕ-scanning. A nontrivial shape of the θ-sections of these contours at a distance from the ϕ center of reflection is revealed; it is different for different samples. For the θ-curves at the center of reflection, we observed a common peak that may be approximated by the Voigt function with a power-low decrease in the intensity at the wings; the decrease law (from-4.5 to-5.0) is found to be considerably greater than that for the similar curves of two-wave diffraction and not depending on the dislocation density and distribution in layers. In some films we observed a coarse-block structure; in addition, it follows from the distribution in the reciprocal space that these blocks are turned with respect to each other around a normal to the surface, which allows us to suggest the existence of low-angle boundaries between them, consisting exclusively of edge dislocations.

New Evidence That Nonlinear Source-Filter Coupling Affects Harmonic Intensity and fo Stability During Instances of Harmonics Crossing Formants.

Science.gov (United States)

Maxfield, Lynn; Palaparthi, Anil; Titze, Ingo

2017-03-01

The traditional source-filter theory of voice production describes a linear relationship between the source (glottal flow pulse) and the filter (vocal tract). Such a linear relationship does not allow for nor explain how changes in the filter may impact the stability and regularity of the source. The objective of this experiment was to examine what effect unpredictable changes to vocal tract dimensions could have on fo stability and individual harmonic intensities in situations in which low frequency harmonics cross formants in a fundamental frequency glide. To determine these effects, eight human subjects (five male, three female) were recorded producing fo glides while their vocal tracts were artificially lengthened by a section of vinyl tubing inserted into the mouth. It was hypothesized that if the source and filter operated as a purely linear system, harmonic intensities would increase and decrease at nearly the same rates as they passed through a formant bandwidth, resulting in a relatively symmetric peak on an intensity-time contour. Additionally, fo stability should not be predictably perturbed by formant/harmonic crossings in a linear system. Acoustic analysis of these recordings, however, revealed that harmonic intensity peaks were asymmetric in 76% of cases, and that 85% of fo instabilities aligned with a crossing of one of the first four harmonics with the first three formants. These results provide further evidence that nonlinear dynamics in the source-filter relationship can impact fo stability as well as harmonic intensities as harmonics cross through formant bandwidths. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Report of the Snowmass M6 Working Group on high intensity proton sources

Energy Technology Data Exchange (ETDEWEB)

Weiren Chou and J. Wei

2002-08-20

The U.S. high-energy physics program needs an intense proton source, a 1-4 MW Proton Driver (PD), by the end of this decade. This machine will serve as a stand-alone facility that will provide neutrino superbeams and other high intensity secondary beams such as kaons, muons, neutrons, and anti-protons (cf. E1 and E5 group reports) and also serve as the first stage of a neutrino factory (cf. M1 group report). It can also be a high brightness source for a VLHC. Based on present accelerator technology and project construction experience, it is both feasible and cost-effective to construct a 1-4 MW Proton Driver. Two recent PD design studies have been made, one at FNAL and the other at the BNL. Both designed PD's for 1 MW proton beams at a cost of about U.S. $200M (excluding contingency and overhead) and both designs were upgradeable to 4 MW. An international collaboration between FNAL, BNL and KEK on high intensity proton facilities is addressing a number of key design issues. The superconducting (sc) RF cavities, cryogenics, and RF controls developed for the SNS can be directly adopted to save R&D efforts, cost, and schedule. PD studies are also actively being pursued at Europe and Japan.

Continuous-variable quantum key distribution with Gaussian source noise

International Nuclear Information System (INIS)

Shen Yujie; Peng Xiang; Yang Jian; Guo Hong

2011-01-01

Source noise affects the security of continuous-variable quantum key distribution (CV QKD) and is difficult to analyze. We propose a model to characterize Gaussian source noise through introducing a neutral party (Fred) who induces the noise with a general unitary transformation. Without knowing Fred's exact state, we derive the security bounds for both reverse and direct reconciliations and show that the bound for reverse reconciliation is tight.

Determining the temperature and density distribution from a Z-pinch radiation source

International Nuclear Information System (INIS)

Matuska, W.; Lee, H.

1997-01-01

High temperature radiation sources exceeding one hundred eV can be produced via z-pinches using currently available pulsed power. The usual approach to compare the z-pinch simulation and experimental data is to convert the radiation output at the source, whose temperature and density distributions are computed from the 2-D MHD code, into simulated data such as a spectrometer reading. This conversion process involves a radiation transfer calculation through the axially symmetric source, assuming local thermodynamic equilibrium (LTE), and folding the radiation that reaches the detector with the frequency-dependent response function. In this paper the authors propose a different approach by which they can determine the temperature and density distributions of the radiation source directly from the spatially resolved spectral data. This unfolding process is reliable and unambiguous for the ideal case where LTE holds and the source is axially symmetric. In reality, imperfect LTE and axial symmetry will introduce inaccuracies into the unfolded distributions. The authors use a parameter optimization routine to find the temperature and density distributions that best fit the data. They know from their past experience that the radiation source resulting from the implosion of a thin foil does not exhibit good axial symmetry. However, recent experiments carried out at Sandia National Laboratory using multiple wire arrays were very promising to achieve reasonably good symmetry. For these experiments the method will provide a valuable diagnostic tool

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.

Astrophysical Ionizing Radiation and Earth: A Brief Review and Census of Intermittent Intense Sources

Science.gov (United States)

Melott, Adrian L.; Thomas, Brian C.

2011-05-01

Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review, we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities, ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere; on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. Both photons (e.g., X-rays) and high-energy protons and other nuclei (often called "cosmic rays") constitute hazards. For either species, one of the mechanisms that comes into play even at moderate intensities is the ionization of Earth's atmosphere, which leads through chemical changes (specifically, depletion of stratospheric ozone) to increased ultraviolet B flux from the Sun reaching the surface. UVB is extremely hazardous to most life due to its strong absorption by the genetic material DNA and subsequent breaking of chemical bonds. This often leads to mutation or cell death. It is easily lethal to the microorganisms that lie at the base of the food chain in the ocean. We enumerate the known sources of radiation and characterize their intensities at Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval," our best estimate of how often a major extinction-level event is probable given the current state of knowledge; we base these estimates on computed or expected depletion of stratospheric ozone. In general, moderate-level events are dominated by the Sun, but the far more severe infrequent events are probably dominated by gamma-ray bursts and supernovae. We note

Astrophysical ionizing radiation and Earth: a brief review and census of intermittent intense sources.

Science.gov (United States)

Melott, Adrian L; Thomas, Brian C

2011-05-01

Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review, we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities, ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere; on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. Both photons (e.g., X-rays) and high-energy protons and other nuclei (often called "cosmic rays") constitute hazards. For either species, one of the mechanisms that comes into play even at moderate intensities is the ionization of Earth's atmosphere, which leads through chemical changes (specifically, depletion of stratospheric ozone) to increased ultraviolet B flux from the Sun reaching the surface. UVB is extremely hazardous to most life due to its strong absorption by the genetic material DNA and subsequent breaking of chemical bonds. This often leads to mutation or cell death. It is easily lethal to the microorganisms that lie at the base of the food chain in the ocean. We enumerate the known sources of radiation and characterize their intensities at Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval," our best estimate of how often a major extinction-level event is probable given the current state of knowledge; we base these estimates on computed or expected depletion of stratospheric ozone. In general, moderate-level events are dominated by the Sun, but the far more severe infrequent events are probably dominated by gamma-ray bursts and supernovae. We note

Radial dose distribution of 192Ir and 137Cs seed sources

International Nuclear Information System (INIS)

Thomason, C.; Higgins, P.

1989-01-01

The radial dose distributions in water around /sup 192/ Ir seed sources with both platinum and stainless steel encapsulation have been measured using LiF thermoluminescent dosimeters (TLD) for distances of 1 to 12 cm along the perpendicular bisector of the source to determine the effect of source encapsulation. Similar measurements also have been made around a /sup 137/ Cs seed source of comparable dimensions. The data were fit to a third order polynomial to obtain an empirical equation for the radial dose factor which then can be used in dosimetry. The coefficients of this equation for each of the three sources are given. The radial dose factor of the stainless steel encapsulated /sup 192/ Ir and that of the platinum encapsulated /sup 192/ Ir agree to within 2%. The radial dose distributions measured here for /sup 192/ Ir with either type of encapsulation and for /sup 137/ Cs are indistinguishable from those of other authors when considering uncertainties involved. For clinical dosimetry based on isotropic point or line source models, any of these equations may be used without significantly affecting accuracy

The oxygen minimum zone (OMZ) off Chile as intense source of CO 2 and N 2O

Science.gov (United States)

Paulmier, A.; Ruiz-Pino, D.; Garcon, V.

2008-12-01

The oxygen minimum zones (OMZs) are recognized as intense sources of N 2O greenhouse gas (GHG) and could also be potential sources of CO 2, the most important GHG for the present climate change. This study evaluates, for one of the most intense and shallow OMZ, the Chilean East South Pacific OMZ, the simultaneous N 2O and CO 2 fluxes at the air-sea interface. Four cruises (2000-2002) and 1 year of monitoring (21°-30°-36°S) off Chile allowed the determination of the CO 2 and N 2O concentrations at the sea surface and the analysis of fluxes variations associated with different OMZ configurations. The Chilean OMZ area can be an intense GHG oceanic local source of both N 2O and CO 2. The mean N 2O fluxes are 5-10 times higher than the maximal previous historical source in an OMZ open area as in the Pacific and Indian Oceans. For CO 2, the mean fluxes are also positive and correspond to very high oceanic sources. Even if different coupling and decoupling between N 2O and CO 2 are observed along the Chilean OMZ, 65% of the situations represent high CO 2 and/or N 2O sources. The high GHG sources are associated with coastal upwelling transport of OMZ waters rich in N 2O and probably also in CO 2, located at a shallow depth. The integrated OMZ role on GHG should be better considered to improve our understanding of the past and future atmospheric CO 2 and N 2O evolutions.

Analytic solution of field distribution and demagnetization function of ideal hollow cylindrical field source

Science.gov (United States)

Xu, Xiaonong; Lu, Dingwei; Xu, Xibin; Yu, Yang; Gu, Min

2017-09-01

The Halbach type hollow cylindrical permanent magnet array (HCPMA) is a volume compact and energy conserved field source, which have attracted intense interests in many practical applications. Here, using the complex variable integration method based on the Biot-Savart Law (including current distributions inside the body and on the surfaces of magnet), we derive analytical field solutions to an ideal multipole HCPMA in entire space including the interior of magnet. The analytic field expression inside the array material is used to construct an analytic demagnetization function, with which we can explain the origin of demagnetization phenomena in HCPMA by taking into account an ideal magnetic hysteresis loop with finite coercivity. These analytical field expressions and demagnetization functions provide deeper insight into the nature of such permanent magnet array systems and offer guidance in designing optimized array system.

Source Coding for Wireless Distributed Microphones in Reverberant Environments

DEFF Research Database (Denmark)

Zahedi, Adel

2016-01-01

. However, it comes with the price of several challenges, including the limited power and bandwidth resources for wireless transmission of audio recordings. In such a setup, we study the problem of source coding for the compression of the audio recordings before the transmission in order to reduce the power...... consumption and/or transmission bandwidth by reduction in the transmission rates. Source coding for wireless microphones in reverberant environments has several special characteristics which make it more challenging in comparison with regular audio coding. The signals which are acquired by the microphones......Modern multimedia systems are more and more shifting toward distributed and networked structures. This includes audio systems, where networks of wireless distributed microphones are replacing the traditional microphone arrays. This allows for flexibility of placement and high spatial diversity...

Tennis Play Intensity Distribution and Relation with Aerobic Fitness in Competitive Players.

Directory of Open Access Journals (Sweden)

Ernest Baiget

Full Text Available The aims of this study were (i to describe the relative intensity of simulated tennis play based on the cumulative time spent in three metabolic intensity zones, and (ii to determine the relationships between this play intensity distribution and the aerobic fitness of a group of competitive players. 20 male players of advanced to elite level (ITN performed an incremental on-court specific endurance tennis test to exhaustion to determine maximal oxygen uptake (VO2max and the first and second ventilatory thresholds (VT1, VT2. Ventilatory and gas exchange parameters were monitored using a telemetric portable gas analyser (K4 b2, Cosmed, Rome, Italy. Two weeks later the participants played a simulated tennis set against an opponent of similar level. Intensity zones (1: low, 2: moderate, and 3: high were delimited by the individual VO2 values corresponding to VT1 and VT2, and expressed as percentage of maximum VO2 and heart rate. When expressed relative to VO2max, percentage of playing time in zone 1 (77 ± 25% was significantly higher (p < 0.001 than in zone 2 (20 ± 21% and zone 3 (3 ± 5%. Moderate to high positive correlations were found between VT1, VT2 and VO2max, and the percentage of playing time spent in zone 1 (r = 0.68-0.75, as well as low to high inverse correlations between the metabolic variables and the percentage of time spent in zone 2 and 3 (r = -0.49-0.75. Players with better aerobic fitness play at relatively lower intensities. We conclude that players spent more than 75% of the time in their low-intensity zone, with less than 25% of the time spent at moderate to high intensities. Aerobic fitness appears to determine the metabolic intensity that players can sustain throughout the game.

Utilization of the intense pulsed neutron source (IPNS) at Argonne National Laboratory for neutron activation analysis

International Nuclear Information System (INIS)

Heinrich, R.R.; Greenwood, L.R.; Popek, R.J.; Schulke, A.W. Jr.

1983-01-01

The Intense Pulsed Neutron Source (IPNS) neutron scattering facility (NSF) has been investigated for its applicability to neutron activation analysis. A polyethylene insert has been added to the vertical hole VT3 which enhances the thermal neutron flux by a factor of two. The neutron spectral distribution at this position has been measured by the multiple-foil technique which utilized 28 activation reactions and the STAYSL computer code. The validity of this spectral measurement was tested by two irradiations of National Bureau of Standards SRM-1571 (orchard leaves), SRM-1575 (pine needles), and SRM-1645 (river sediment). The average thermal neutron flux for these irradiations normalized to 10 μamp proton beam is 4.0 x 10 11 n/cm 2 -s. Concentrations of nine trace elements in each of these SRMs have been determined by gamma-ray spectrometry. Agreement of measured values to certified values is demonstrated to be within experiment error

Memory intensive functional architecture for distributed computer control systems

International Nuclear Information System (INIS)

Dimmler, D.G.

1983-10-01

A memory-intensive functional architectue for distributed data-acquisition, monitoring, and control systems with large numbers of nodes has been conceptually developed and applied in several large-scale and some smaller systems. This discussion concentrates on: (1) the basic architecture; (2) recent expansions of the architecture which now become feasible in view of the rapidly developing component technologies in microprocessors and functional large-scale integration circuits; and (3) implementation of some key hardware and software structures and one system implementation which is a system for performing control and data acquisition of a neutron spectrometer at the Brookhaven High Flux Beam Reactor. The spectrometer is equipped with a large-area position-sensitive neutron detector

Accelerator-based intense neutron source for materials R and D

International Nuclear Information System (INIS)

Jameson, R.A.

1990-01-01

Accelerator-based neutron sources for R and D of materials in nuclear energy systems, including fusion reactors, can provide sufficient neutron flux, flux-volume, fluence and other attractive features for many aspects of materials research. The neutron spectrum produced from the D-Li reaction has been judged useful for many basic materials research problems, and satisfactory as an approximation of the fusion process. A most interesting aspect for materials researchers is the increased flexibility and opportunities for experimental configurations that a modern accelerator-based source could add to the set of available tools. First, of course, is a high flux of neutrons. Four other tools are described: 1. The output energy of the deuteron beam can be varied to provide energy selectivity for the materials researcher. The energy would typically be varied in discrete steps; the number of steps can be adjusted depending on actual needs and costs. 2. The materials sample target chamber could be irradiated by more than one beam, from different angles. This would provide many possibilities for tailoring the flux distribution. 3. Advanced techniques in magnetic optics systems allow the density distribution of the deuteron beam at the target to be tailored. Controlled distributions from Gaussian to uniform to hollow can be provided. This affords further control of the distribution in the target chamber. 4. The accelerator and associated beam transport elements are all essentially electronic systems and, therefore, can be controlled and modulated on a time cycle basis. Therefore, all of the above tools could be varied in possibly complex patterns under computer control; this may open further experimental approaches for studying various rate-dependent effects. These considerations will be described in the context of the Energy Selective Neutron Irradiation Test (ESNIT) facility which is conceived at JAERI. (author)

A deuteron linac for a high-intensity neutron source

International Nuclear Information System (INIS)

Staples, J.; Clark, D.; Grunder, H.; Lancaster, H.; Main, R.; Selph, F.; Smith, L.; Voelker, F.; Yourd, R.

1976-01-01

The preliminary design of an accelerator suitable to meet the flux and neutron energy requirements of a CTR materials test facility is presented. The specifications of such a facility call for a neutron flux of 10 14 n/cm 2 -sec distributed over an area of about 10 2 cm 2 with a neutron spectrum similar to that anticipated from a fusion reactor. A 30 MeV deuteron linac producing a CW beam of 125 mA, upgradable to 40 MeV at 250 mA at a later date, would produce the relatively broad spectrum of neutrons at the required intensity. Attention to the low-energy beam intercept on the drift tubes and diffusive losses producing neutrons and attendant activation problems are discussed

Influence of Different Light Sources, Illumination Intensities and Storage Times on the Vitamin C Content in Pasteurized Milk

OpenAIRE

ÇAKMAKÇI, Songül; TURGUT, Tamer

2005-01-01

The effect of various light sources and illumination intensities on the destruction of vitamin C was determined during the storage of pasteurized milk. For this purpose, raw cow's milk was pasteurized at 72 oC for 15 s, and then stored in 2 different refrigerators (4 ± 1oC) illuminated by fluorescent and tungsten light (normal light) sources with intensities of 1100, 2400 and 5800 lux. As a control group, a pasteurized milk sample was stored at the same temperature under dark conditi...

Tsunami Source Identification on the 1867 Tsunami Event Based on the Impact Intensity

Science.gov (United States)

Wu, T. R.

2014-12-01

The 1867 Keelung tsunami event has drawn significant attention from people in Taiwan. Not only because the location was very close to the 3 nuclear power plants which are only about 20km away from the Taipei city but also because of the ambiguous on the tsunami sources. This event is unique in terms of many aspects. First, it was documented on many literatures with many languages and with similar descriptions. Second, the tsunami deposit was discovered recently. Based on the literatures, earthquake, 7-meter tsunami height, volcanic smoke, and oceanic smoke were observed. Previous studies concluded that this tsunami was generated by an earthquake with a magnitude around Mw7.0 along the Shanchiao Fault. However, numerical results showed that even a Mw 8.0 earthquake was not able to generate a 7-meter tsunami. Considering the steep bathymetry and intense volcanic activities along the Keelung coast, one reasonable hypothesis is that different types of tsunami sources were existed, such as the submarine landslide or volcanic eruption. In order to confirm this scenario, last year we proposed the Tsunami Reverse Tracing Method (TRTM) to find the possible locations of the tsunami sources. This method helped us ruling out the impossible far-field tsunami sources. However, the near-field sources are still remain unclear. This year, we further developed a new method named 'Impact Intensity Analysis' (IIA). In the IIA method, the study area is divided into a sequence of tsunami sources, and the numerical simulations of each source is conducted by COMCOT (Cornell Multi-grid Coupled Tsunami Model) tsunami model. After that, the resulting wave height from each source to the study site is collected and plotted. This method successfully helped us to identify the impact factor from the near-field potential sources. The IIA result (Fig. 1) shows that the 1867 tsunami event was a multi-source event. A mild tsunami was trigged by a Mw7.0 earthquake, and then followed by the submarine

Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrodeless Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

OpenAIRE

Gavare, Zanda; Revalde, Gita; Skudra, Atis

2010-01-01

The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-α diagonal band (d3Πu−→a3∑g+ electronic transition; Q-branch with v=v′=2) to determine the temperature of hydrogen containing high-frequency electrodeless lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied curren...

Binomial probability distribution model-based protein identification algorithm for tandem mass spectrometry utilizing peak intensity information.

Science.gov (United States)

Xiao, Chuan-Le; Chen, Xiao-Zhou; Du, Yang-Li; Sun, Xuesong; Zhang, Gong; He, Qing-Yu

2013-01-04

Mass spectrometry has become one of the most important technologies in proteomic analysis. Tandem mass spectrometry (LC-MS/MS) is a major tool for the analysis of peptide mixtures from protein samples. The key step of MS data processing is the identification of peptides from experimental spectra by searching public sequence databases. Although a number of algorithms to identify peptides from MS/MS data have been already proposed, e.g. Sequest, OMSSA, X!Tandem, Mascot, etc., they are mainly based on statistical models considering only peak-matches between experimental and theoretical spectra, but not peak intensity information. Moreover, different algorithms gave different results from the same MS data, implying their probable incompleteness and questionable reproducibility. We developed a novel peptide identification algorithm, ProVerB, based on a binomial probability distribution model of protein tandem mass spectrometry combined with a new scoring function, making full use of peak intensity information and, thus, enhancing the ability of identification. Compared with Mascot, Sequest, and SQID, ProVerB identified significantly more peptides from LC-MS/MS data sets than the current algorithms at 1% False Discovery Rate (FDR) and provided more confident peptide identifications. ProVerB is also compatible with various platforms and experimental data sets, showing its robustness and versatility. The open-source program ProVerB is available at http://bioinformatics.jnu.edu.cn/software/proverb/ .

Application of FEL technique for constructing high-intensity, monochromatic, polarized gamma-sources at storage rings

Energy Technology Data Exchange (ETDEWEB)

Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N. [Automatic Systems Corporation, Samara (Russian Federation)] [and others

1995-12-31

A possibility to construct high-intensity tunable monochromatic{gamma}-source at high energy storage rings is discussed. It is proposed to produce {gamma}-quanta by means of Compton backscattering of laser photons on electrons circulating in the storage. The laser light wavelength is chosen in such a way that after the scattering, the electron does not leave the separatrix. So as the probability of the scattering is rather small, energy oscillations are damped prior the next scattering. As a result, the proposed source can operate in {open_quotes}parasitic{close_quote} mode not interfering with the main mode of the storage ring operation. Analysis of parameters of existent storage rings (PETRA, ESRF, Spring-8, etc) shows that the laser light wavelength should be in infrared, {lambda}{approximately} 10 - 400 {mu}m, wavelength band. Installation at storage rings of tunable free-electron lasers with the peak and average output power {approximately} 10 MW and {approximately} 1 kW, respectively, will result in the intensity of the {gamma}-source up to {approximately} 10{sup 14}s{sup -1} with tunable {gamma}-quanta energy from several MeV up to several hundreds MeV. Such a {gamma}-source will reveal unique possibilities for precision investigations in nuclear physics.

Quantum key distribution with an unknown and untrusted source

Science.gov (United States)

Zhao, Yi; Qi, Bing; Lo, Hoi-Kwong

2009-03-01

The security of a standard bi-directional ``plug & play'' quantum key distribution (QKD) system has been an open question for a long time. This is mainly because its source is equivalently controlled by an eavesdropper, which means the source is unknown and untrusted. Qualitative discussion on this subject has been made previously. In this paper, we present the first quantitative security analysis on a general class of QKD protocols whose sources are unknown and untrusted. The securities of standard BB84 protocol, weak+vacuum decoy state protocol, and one-decoy decoy state protocol, with unknown and untrusted sources are rigorously proved. We derive rigorous lower bounds to the secure key generation rates of the above three protocols. Our numerical simulation results show that QKD with an untrusted source gives a key generation rate that is close to that with a trusted source. Our work is published in [1]. [4pt] [1] Y. Zhao, B. Qi, and H.-K. Lo, Phys. Rev. A, 77:052327 (2008).

The Impact of Dissociator Cooling on the Beam Intensity and Velocity in the SpinLab ABS

Science.gov (United States)

Stancari, M.; Barion, L.; Bonomo, C.; Capiluppi, M.; Contalbrigo, M.; Ciullo, G.; Dalpiaz, P. F.; Giordano, F.; Lenisa, P.; Pappalardo, L.; Statera, M.; Wang, M.

2007-06-01

At the SpinLab laboratory (University of Ferrara, Italy), a three stage cooling system was installed along the dissociator tube of an atomic beam source (ABS). With this tool, it is possible to observe correlations between the measured temperatures and the atomic beam intensity. The existence of such correlations is suggested by the larger intensity of the RHIC ABS, the only other source with additional cooling stages. An increased intensity at lower cooling temperatures was observed in SpinLab, while no change in the beam's velocity distribution was observed.

The Intense Slow Positron Source concept: A theoretical perspective on a proposed INEL Facility

International Nuclear Information System (INIS)

Makowitz, H.; Abrashoff, J.D.; Landman, W.H.; Albano, R.K.; Tajima, T.

1992-01-01

An analysis has been performed of the INEL Intense Slow Positron Source (ISPS) concept. The results of the theoretical study are encouraging. A full-scale device with a monoenergetic 5 KeV positron beam of ≥10 12 e + /s on a ≤0.03-cmdiameter target appears feasible and can be obtained within the existing infrastructure of INEL reactor facilities. A 30.0-cm-diameter, large area source dish, moderated at first with thin crystalline W films and later by solid Ne, is proposed as the initial device in order to explore problems with a facility scale system. A demonstration scale beam at ≥10 10 slow e + /s is proposed using a 58 Co source plated on a 6-cm-diameter source dish insert, placed in a 30- cm adapter

Blind Separation of Nonstationary Sources Based on Spatial Time-Frequency Distributions

Directory of Open Access Journals (Sweden)

Zhang Yimin

2006-01-01

Full Text Available Blind source separation (BSS based on spatial time-frequency distributions (STFDs provides improved performance over blind source separation methods based on second-order statistics, when dealing with signals that are localized in the time-frequency (t-f domain. In this paper, we propose the use of STFD matrices for both whitening and recovery of the mixing matrix, which are two stages commonly required in many BSS methods, to provide robust BSS performance to noise. In addition, a simple method is proposed to select the auto- and cross-term regions of time-frequency distribution (TFD. To further improve the BSS performance, t-f grouping techniques are introduced to reduce the number of signals under consideration, and to allow the receiver array to separate more sources than the number of array sensors, provided that the sources have disjoint t-f signatures. With the use of one or more techniques proposed in this paper, improved performance of blind separation of nonstationary signals can be achieved.

Wearable Sensor Localization Considering Mixed Distributed Sources in Health Monitoring Systems.

Science.gov (United States)

Wan, Liangtian; Han, Guangjie; Wang, Hao; Shu, Lei; Feng, Nanxing; Peng, Bao

2016-03-12

In health monitoring systems, the base station (BS) and the wearable sensors communicate with each other to construct a virtual multiple input and multiple output (VMIMO) system. In real applications, the signal that the BS received is a distributed source because of the scattering, reflection, diffraction and refraction in the propagation path. In this paper, a 2D direction-of-arrival (DOA) estimation algorithm for incoherently-distributed (ID) and coherently-distributed (CD) sources is proposed based on multiple VMIMO systems. ID and CD sources are separated through the second-order blind identification (SOBI) algorithm. The traditional estimating signal parameters via the rotational invariance technique (ESPRIT)-based algorithm is valid only for one-dimensional (1D) DOA estimation for the ID source. By constructing the signal subspace, two rotational invariant relationships are constructed. Then, we extend the ESPRIT to estimate 2D DOAs for ID sources. For DOA estimation of CD sources, two rational invariance relationships are constructed based on the application of generalized steering vectors (GSVs). Then, the ESPRIT-based algorithm is used for estimating the eigenvalues of two rational invariance matrices, which contain the angular parameters. The expressions of azimuth and elevation for ID and CD sources have closed forms, which means that the spectrum peak searching is avoided. Therefore, compared to the traditional 2D DOA estimation algorithms, the proposed algorithm imposes significantly low computational complexity. The intersecting point of two rays, which come from two different directions measured by two uniform rectangle arrays (URA), can be regarded as the location of the biosensor (wearable sensor). Three BSs adopting the smart antenna (SA) technique cooperate with each other to locate the wearable sensors using the angulation positioning method. Simulation results demonstrate the effectiveness of the proposed algorithm.

Spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources. Experimental results

International Nuclear Information System (INIS)

Panitzsch, Lauri

2013-01-01

The experimental determination of the spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources (ECRIS) defines the focus of this thesis. The spatial distributions of different ion species were obtained in the object plane of the bending magnet (∼45 cm downstream from the plasma electrode) and in the plane of the plasma electrode itself, both in high spatial resolution. The results show that each of the different ion species forms a bloated, triangular structure in the aperture of the plasma electrode. The geometry and the orientation of these structures are defined by the superposition of the radial and axial magnetic fields. The radial extent of each structure is defined by the charge of the ion. Higher charge states occupy smaller, more concentrated structures. The total current density increases towards the center of the plasma electrode. The circular and star-like structures that can be observed in the beam profiles of strongly focused, extracted ion beams are each dominated by ions of a single charge state. In addition, the spatially resolved current density distribution of charged particles in the plasma chamber that impinge on the plasma electrode was determined, differentiating between ions and electrons. The experimental results of this work show that the electrons of the plasma are strongly connected to the magnetic field lines in the source and thus spatially well confined in a triangular-like structure. The intensity of the electrons increases towards the center of the plasma electrode and the plasma chamber, as well. These electrons are surrounded by a spatially far less confined and less intense ion population. All the findings mentioned above were already predicted in parts by simulations of different groups. However, the results presented within this thesis represent the first (and by now only) direct experimental verification of those predictions and are qualitatively transferable to other

Spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources. Experimental results

Energy Technology Data Exchange (ETDEWEB)

Panitzsch, Lauri

2013-02-08

The experimental determination of the spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources (ECRIS) defines the focus of this thesis. The spatial distributions of different ion species were obtained in the object plane of the bending magnet ({approx}45 cm downstream from the plasma electrode) and in the plane of the plasma electrode itself, both in high spatial resolution. The results show that each of the different ion species forms a bloated, triangular structure in the aperture of the plasma electrode. The geometry and the orientation of these structures are defined by the superposition of the radial and axial magnetic fields. The radial extent of each structure is defined by the charge of the ion. Higher charge states occupy smaller, more concentrated structures. The total current density increases towards the center of the plasma electrode. The circular and star-like structures that can be observed in the beam profiles of strongly focused, extracted ion beams are each dominated by ions of a single charge state. In addition, the spatially resolved current density distribution of charged particles in the plasma chamber that impinge on the plasma electrode was determined, differentiating between ions and electrons. The experimental results of this work show that the electrons of the plasma are strongly connected to the magnetic field lines in the source and thus spatially well confined in a triangular-like structure. The intensity of the electrons increases towards the center of the plasma electrode and the plasma chamber, as well. These electrons are surrounded by a spatially far less confined and less intense ion population. All the findings mentioned above were already predicted in parts by simulations of different groups. However, the results presented within this thesis represent the first (and by now only) direct experimental verification of those predictions and are qualitatively transferable to

Low preveance ion source bridges low and high intensities in ion implantation

International Nuclear Information System (INIS)

Orr, F.D.; Mayhall, D.

1976-01-01

The Low Perveance Ion Source developed by Accelerators, Inc. offers the Semiconductor Industry the advantage of processing medium to high intensity implants on a system which will also implant 200 to 300 wafers an hour at MOS doses. Stable source beam currents can be varied over three orders of magnitude by variation of a single source parameter. This source uses a new computer designed Low Perveance extraction optics which is completely new to the Ion Implantation Industry. Test data and calculations are shown which define the versatility of this system. Scanned currents from 1 microamp to 400 microamps allow for a variety of production processing. Beam characteristics feature low energy spread (less than 10 eV) and low divergence (less than 3 degrees). Beam control optics consist of a double focusing analyzing magnet and two triplet quadrupoles. The source may be fitted with an oven for feeding of solid materials and analyzed beam currents in the milliamp range for development purposes. The batch processing, hybrid scanning end station is most applicable for high current beams as well as high volume batch processings of MOS Implants. Results of development work toward increased currents using both solid and gas feed material with the Low Perveance source are presented. System improvements including Accel-Decel and a third extraction element are discussed

Simulated and measured neutron/gamma light output distribution for poly-energetic neutron/gamma sources

Science.gov (United States)

Hosseini, S. A.; Zangian, M.; Aghabozorgi, S.

2018-03-01

In the present paper, the light output distribution due to poly-energetic neutron/gamma (neutron or gamma) source was calculated using the developed MCNPX-ESUT-PE (MCNPX-Energy engineering of Sharif University of Technology-Poly Energetic version) computational code. The simulation of light output distribution includes the modeling of the particle transport, the calculation of scintillation photons induced by charged particles, simulation of the scintillation photon transport and considering the light resolution obtained from the experiment. The developed computational code is able to simulate the light output distribution due to any neutron/gamma source. In the experimental step of the present study, the neutron-gamma discrimination based on the light output distribution was performed using the zero crossing method. As a case study, 241Am-9Be source was considered and the simulated and measured neutron/gamma light output distributions were compared. There is an acceptable agreement between the discriminated neutron/gamma light output distributions obtained from the simulation and experiment.

Confusion-limited extragalactic source survey at 4.755 GHz. I. Source list and areal distributions

International Nuclear Information System (INIS)

Ledden, J.E.; Broderick, J.J.; Condon, J.J.; Brown, R.L.

1980-01-01

A confusion-limited 4.755-GHz survey covering 0.00 956 sr between right ascensions 07/sup h/05/sup m/ and 18/sup h/ near declination +35 0 has been made with the NRAO 91-m telescope. The survey found 237 sources and is complete above 15 mJy. Source counts between 15 and 100 mJy were obtained directly. The P(D) distribution was used to determine the number counts between 0.5 and 13.2 mJy, to search for anisotropy in the density of faint extragalactic sources, and to set a 99%-confidence upper limit of 1.83 mK to the rms temperature fluctuation of the 2.7-K cosmic microwave background on angular scales smaller than 7.3 arcmin. The discrete-source density, normalized to the static Euclidean slope, falls off sufficiently rapidly below 100 mJy that no new population of faint flat-spectrum sources is required to explain the 4.755-GHz source counts

Transfer standard for the spectral density of relative intensity noise of optical fiber sources near 1550 nm

International Nuclear Information System (INIS)

Obarski, Gregory E.; Splett, Jolene D.

2001-01-01

We have developed a transfer standard for the spectral density of relative intensity noise (RIN) of optical fiber sources near 1550 nm. Amplified spontaneous emission (ASE) from an erbium-doped fiber amplifier (EDFA), when it is optically filtered over a narrow band (<5 nm), yields a stable RIN spectrum that is practically constant to several tens of gigahertz. The RIN is calculated from the power spectral density as measured with a calibrated optical spectrum analyzer. For a typical device it is -110 dB/Hz, with uncertainty ≤0.12 dB/Hz. The invariance of the RIN under attenuation yields a considerable dynamic range with respect to rf noise levels. Results are compared with those from a second method that uses a distributed-feedback laser (DFB) that has a Poisson-limited RIN. Application of each method to the same RIN measurement system yields frequency-dependent calibration functions that, when they are averaged, differ by ≤0.2 dB. [copyright] 2001 Optical Society of America

Ion energy distributions from laser-generated plasmas at two different intensities

Science.gov (United States)

Ceccio, Giovanni; Torrisi, Lorenzo; Okamura, Masahiro; Kanesue, Takeshi; Ikeda, Shunsuke

2018-01-01

Laser-generated non-equilibrium plasmas were analyzed at Brookhaven National Laboratory (NY, USA) and MIFT Messina University (Italy). Two laser intensities of 1012 W/cm2 and 109 W/cm2, have been employed to irradiate Al and Al with Au coating targets in high vacuum conditions. Ion energy distributions were obtained using electrostatic analyzers coupled with ion collectors. Time of flight measurements were performed by changing the laser irradiation conditions. The study was carried out to provide optimum keV ions injection into post acceleration systems. Possible applications will be presented.

Packets distribution in a tree-based topology wireless sensor networks

CSIR Research Space (South Africa)

Akpakwu, GA

2016-07-01

Full Text Available The concept of data distribution within cluster of sensor nodes to the source sink has resulted to intense research in Wireless Sensor Networks (WSNs). In this paper, in order to determine the scheduling length of packet distribution, a tree...

A modified high-intensity Cs sputter negative-ion source with multi-target mechanism

International Nuclear Information System (INIS)

Si Houzhi; Zhang Weizhong; Zhu Jinhau; Du Guangtian; Zhang Tiaorong; Gao Xiang

1993-01-01

The source is based on Middleton's high-intensity mode, but modified to a multi-target version. It is equipped with a spherical molybdenum ionizer, a 20-position target wheel and a vacuum lock for loading and unloading sample batches. A metal-ceramic bonded section protected by a specially designed labyrinth shielding system results in reliable insulation of the cathode and convenient control of cesium vapor. The latter is particularly important when an oversupply of cesium occurs. The source was developed for accelerator mass spectrometry (AMS) applications. Recently, three versions based on the prototype of the source have been successfully tested to meet different requirements: (a) Single target version, (b) multi-target version with manual sample change, and (c) multi-target version with remote control sample change. Some details of the technical and operational characteristics are presented. (orig.)

Spatial distribution and implications to sources of halogenated flame retardants in riverine sediments of Taizhou, an intense e-waste recycling area in eastern China.

Science.gov (United States)

Zhou, Shanshan; Fu, Jie; He, Huan; Fu, Jianjie; Tang, Qiaozhi; Dong, Minfeng; Pan, Yongqiang; Li, An; Liu, Weiping; Zhang, Limin

2017-10-01

Concentrations and spatial distribution pattern of organohalogen flame retardants were investigated in the riverine surface sediments from Taizhou, an intensive e-waste recycling region in China. The analytes were syn- and anti- Dechlorane Plus (DP), Dechloranes 602, 603, and 604, a DP monoadduct, two dechlorinated DPs and 8 congeners of polybrominated diphenyl ethers (PBDEs). The concentrations of Σ 8 PBDEs, ΣDP, ΣDec600s, and ΣDP-degradates ranged from recycling facilities. Such patterns were largely shared by Dec602 and dechlorinated DP, although their concentration levels were much lower. These major flame retardants significantly correlate with each other, and cluster together in the loading plot of principle component analysis. In contrast, most non-deca PBDE congeners do not correlate with DPs. Dec604 stood out having distinctly different spatial distribution pattern, which could be linked to historical use of mirex. Organic matter content of the sediment was not the dominant factor in determining the spatial pattern of pollution by halogenated flame retardants in the rivers of this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

A calculation of dose distribution around 32P spherical sources and its clinical application

International Nuclear Information System (INIS)

Ohara, Ken; Tanaka, Yoshiaki; Nishizawa, Kunihide; Maekoshi, Hisashi

1977-01-01

In order to avoid the radiation hazard in radiation therapy of craniopharyngioma by using 32 P, it is helpful to prepare a detailed dose distribution in the vicinity of the source in the tissue. Valley's method is used for calculations. A problem of the method is pointed out and the method itself is refined numerically: it extends a region of xi where an approximate polynomial is available, and it determines an optimum degree of the polynomial as 9. Usefulness of the polynomial is examined by comparing with Berger's scaled absorbed dose distribution F(xi) and the Valley's result. The dose and dose rate distributions around uniformly distributed spherical sources are computed from the termwise integration of our polynomial of degree 9 over the range of xi from 0 to 1.7. The dose distributions calculated from the spherical surface to a point at 0.5 cm outside the source, are given, when the radii of sources are 0.5, 0.6, 0.7, 1.0, and 1.5 cm respectively. The therapeutic dose for a craniopharyngioma which has a spherically shaped cyst, and the absorbed dose to the normal tissue, (oculomotor nerve), are obtained from these dose rate distributions. (auth.)

Laser plasma as a source of intense attosecond pulses via high-order harmonic generation

International Nuclear Information System (INIS)

Ozaki, T.

2013-01-01

The incredible progress in ultrafast laser technology and Ti:sapphire lasers have lead to many important applications, one of them being high-order harmonic generation (HHG). HHG is a source of coherent extreme ultraviolet (XUV) radiation, which has opened new frontiers in science by extending nonlinear optics and time-resolved spectroscopy to the XUV region, and pushing ultrafast science to the attosecond domain. Progress in attosecond science has revealed many new phenomena that have not been seen with femtosecond pulses. Clearly, the next frontier is to study nonlinear effects at the attosecond timescale and in the XUV. However, a problem with present-day attosecond pulses is that they are just too weak to induce measurable nonlinearities, which severely limits the application of this source. While HHG from solid targets has shown promise for higher conversion efficiency, there is no experiment so far that demonstrates isolated attosecond pulse generation. The generation of isolated, several 100-as pulses with few-µJ energy will enable us to enter a completely new phase in attoscience. In past works, we have demonstrated that high-order harmonics from lowly ionized plasma is a highly efficient method to generate coherent XUV pulses. For example, indium plasma has been shown to generate intense 13th harmonic of the Ti:sapphire laser, with conversion efficiency of 10-4. However, the quasi-monochromatic nature of indium harmonics would make it difficult to generate attosecond pulses. We have also demonstrated that one could increase the harmonic yield by using nanoparticle targets. Specifically, we showed that by using indium oxide nanoparticles or C60 film, we could obtain intense harmonics between wavelengths of 50 to 90 nm. The energy in each of these harmonic orders was measured to be a few µJ, which is sufficient for many applications. However, the problem of using nanoparticle or film targets is the rapid decrease in the harmonic intensity, due to the rapid

The biological shield of a high-intensity spallation source: a monte Carlo design study

International Nuclear Information System (INIS)

Koprivnikar, I.; Schachinger, E.

2004-01-01

The design of high-intensity spallation sources requires the best possible estimates for the biological shield. The applicability of three-dimensional Monte Carlo simulation in the design of the biological shield of a spallation source will be discussed. In order to achieve reasonable computing times along with acceptable accuracy, biasing techniques are to be employed and it was the main purpose of this work to develop a strategy for an effective Monte Carlo simulation in shielding design. The most prominent MC computer codes, namely MCNPX and FLUKA99, have been applied to the same model spallation source (the European Spallation Source) and on the basis of the derived strategies, the design and characteristics of the target station shield are discussed. It is also the purpose of the paper to demonstrate the application of the developed strategy for the design of beam lines with their shielding using as an example the target-moderator-reflector complex of the ESS as the primary particle source. (author)

Intensity enhancement of cold neutrons from a coupled liquid-hydrogen moderator for pulsed cold neutron sources

International Nuclear Information System (INIS)

Ogawa, Y.; Kiyanagi, Y.; Kosugi, N.; Iwasa, H.; Furusaka, M.; Watanabe, N.

1999-01-01

In order to obtain higher cold neutron intensity from a coupled liquid-hydrogen moderator with a premoderator for pulsed cold neutron sources, we examined a partial enhancement method, namely, narrow beam extraction for both a flat liquid-hydrogen moderator and a single-groove one. Combined with the narrow beam extraction, which is especially suitable for small-angle scattering and neutron reflectometry experiments, a single-groove moderator provides higher intensity, by about 30%, than a flat-surface moderator at the region of interest on a viewed surface. The effect of double-side beam extraction from such moderators on the intensity gain factor is also discussed. (author)

Quantum key distribution with entangled photon sources

International Nuclear Information System (INIS)

Ma Xiongfeng; Fung, Chi-Hang Fred; Lo, H.-K.

2007-01-01

A parametric down-conversion (PDC) source can be used as either a triggered single-photon source or an entangled-photon source in quantum key distribution (QKD). The triggering PDC QKD has already been studied in the literature. On the other hand, a model and a post-processing protocol for the entanglement PDC QKD are still missing. We fill in this important gap by proposing such a model and a post-processing protocol for the entanglement PDC QKD. Although the PDC model is proposed to study the entanglement-based QKD, we emphasize that our generic model may also be useful for other non-QKD experiments involving a PDC source. Since an entangled PDC source is a basis-independent source, we apply Koashi and Preskill's security analysis to the entanglement PDC QKD. We also investigate the entanglement PDC QKD with two-way classical communications. We find that the recurrence scheme increases the key rate and the Gottesman-Lo protocol helps tolerate higher channel losses. By simulating a recent 144-km open-air PDC experiment, we compare three implementations: entanglement PDC QKD, triggering PDC QKD, and coherent-state QKD. The simulation result suggests that the entanglement PDC QKD can tolerate higher channel losses than the coherent-state QKD. The coherent-state QKD with decoy states is able to achieve highest key rate in the low- and medium-loss regions. By applying the Gottesman-Lo two-way post-processing protocol, the entanglement PDC QKD can tolerate up to 70 dB combined channel losses (35 dB for each channel) provided that the PDC source is placed in between Alice and Bob. After considering statistical fluctuations, the PDC setup can tolerate up to 53 dB channel losses

The Integration of Renewable Energy Sources into Electric Power Distribution Systems, Vol. II Utility Case Assessments

Energy Technology Data Exchange (ETDEWEB)

Zaininger, H.W.

1994-01-01

Electric utility distribution system impacts associated with the integration of renewable energy sources such as photovoltaics (PV) and wind turbines (WT) are considered in this project. The impacts are expected to vary from site to site according to the following characteristics: the local solar insolation and/or wind characteristics, renewable energy source penetration level, whether battery or other energy storage systems are applied, and local utility distribution design standards and planning practices. Small, distributed renewable energy sources are connected to the utility distribution system like other, similar kW- and MW-scale equipment and loads. Residential applications are expected to be connected to single-phase 120/240-V secondaries. Larger kW-scale applications may be connected to three+phase secondaries, and larger hundred-kW and y-scale applications, such as MW-scale windfarms, or PV plants, may be connected to electric utility primary systems via customer-owned primary and secondary collection systems. In any case, the installation of small, distributed renewable energy sources is expected to have a significant impact on local utility distribution primary and secondary system economics. Small, distributed renewable energy sources installed on utility distribution systems will also produce nonsite-specific utility generation system benefits such as energy and capacity displacement benefits, in addition to the local site-specific distribution system benefits. Although generation system benefits are not site-specific, they are utility-specific, and they vary significantly among utilities in different regions. In addition, transmission system benefits, environmental benefits and other benefits may apply. These benefits also vary significantly among utilities and regions. Seven utility case studies considering PV, WT, and battery storage were conducted to identify a range of potential renewable energy source distribution system applications. The

Fan beam intensity modulated proton therapy

Science.gov (United States)

Hill, Patrick M.

A fan beam proton therapy is developed which delivers intensity modulated proton therapy using distal edge tracking. The system may be retrofit onto existing proton therapy gantries without alterations to infrastructure in order to improve treatments through intensity modulation. A novel range and intensity modulation system is designed using acrylic leaves that are inserted or retracted from subsections of the fan beam. Leaf thicknesses are chosen in a base-2 system and motivated in a binary manner. Dose spots from individual beam channels range between 1 and 5 cm. Integrated collimators attempting to limit crosstalk among beam channels are investigated, but found to be inferior to uncollimated beam channel modulators. A treatment planning system performing data manipulation in MATLAB and dose calculation in MCNPX is developed. Beamlet dose is calculated on patient CT data and a fan beam source is manually defined to produce accurate results. An energy deposition tally follows the CT grid, allowing straightforward registration of dose and image data. Simulations of beam channels assume that a beam channel either delivers dose to a distal edge spot or is intensity modulated. A final calculation is performed separately to determine the deliverable dose accounting for all sources of scatter. Treatment plans investigate the effects that varying system parameters have on dose distributions. Beam channel apertures may be as large as 20 mm because the sharp distal falloff characteristic of proton dose provides sufficient intensity modulation to meet dose objectives, even in the presence of coarse lateral resolution. Dose conformity suffers only when treatments are delivered from less than 10 angles. Jaw widths of 1--2 cm produce comparable dose distributions, but a jaw width of 4 cm produces unacceptable target coverage when maintaining critical structure avoidance. Treatment time for a prostate delivery is estimated to be on the order of 10 minutes. Neutron production

Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrode less Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

International Nuclear Information System (INIS)

Gavare, Z.; Revalde, G.; Skudra, A.

2011-01-01

The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-a diagonal band (d3η u- a3Σg + electronic transition; Q-branch with ν=ν=2) to determine the temperature of hydrogen containing high-frequency electrode less lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied current. The results have been compared with the method of temperature derivation from Doppler profiles of He 667.8 nm and Ar 772.4 nm lines. The results of both methods are in good agreement, showing that the method of gas temperature determination from the intensity distribution in the hydrogen Fulcher-a (2-2)Q band can be used for the hydrogen containing HFEDLs. It was observed that the admixture of 10% hydrogen in the argon HFEDLs significantly reduces the gas temperature

Assessment of the signal intensity distribution pattern within the unruptured cerebral aneurysms using color-coded 3D MR angiography

International Nuclear Information System (INIS)

Satoh, Toru; Omi, Megumi; Ohsako, Chika

2005-01-01

To evaluate the interaction between the MR signal intensity distribution pattern and bleb formation/deformation of the aneurysmal dome, fifty cases of the unruptured cerebral aneurysms were investigated with the color-coded 3D MR angiography. Patterns were categorized into central-type, neck-type and peripheral-type according to the distribution of MR signals with low-, moderate- and high signal intensity areas. Imaging analysis revealed the significant relationship (P<0.02) of the peripheral-type aneurysms to the bleb formation and deformation of the dome, compared with those of central- and neck-type. Additionally, peripheral-type signal intensity distribution pattern was shown with aneurysms harboring relatively large dome size and lateral-type growth including internal carotid aneurysms. Prospective analysis of intraaneurysmal flow pattern with the color-coded 3D MR angiography may provide patient-specific analysis of intraaneurysmal flow status in relation to the morphological change of the corresponding aneurysmal dome in the management of unruptured cerebral aneurysms. (author)

Variation of rain intensity and drop size distribution with General Weather Patterns (GWL)

Science.gov (United States)

Ghada, Wael; Buras, Allan; Lüpke, Marvin; Menzel, Annette

2017-04-01

Short-duration rainfall extremes may cause flash floods in certain catchments (e.g. cities or fast responding watersheds) and pose a great risk to affected communities. In order to predict their occurrence under future climate change scenarios, their link to atmospheric circulation patterns needs to be well understood. We used a comprehensive data set of meteorological data (temperature, rain gauge precipitation) and precipitation spectra measured by a disdrometer (OTT PARSIVEL) between October 2008 and June 2010 at Freising, southern Germany. For the 21 months of the study period, we integrated the disdrometer spectra over intervals of 10 minutes to correspond to the temporal resolution of the weather station data and discarded measurements with air temperatures below 0°C. Daily General Weather Patterns ("Großwetterlagen", GWL) were downloaded from the website of the German Meteorological Service. Out of the 29 GWL, 14 were included in the analysis for which we had at least 12 rain events during our study period. For the definition of a rain event, we tested different lengths of minimum inter-event times and chose 30 min as a good compromise between number and length of resulting events; rain events started when more than 0.001 mm/h (sensitivity of the disdrometer) were recorded. The length of the rain events ranged between 10 min and 28 h (median 130 min) with the maximum rain intensity recorded being 134 mm/h on 24-07-2009. Seasonal differences were identified for rain event average intensities and maximum intensities per event. The influence of GWL on rain properties such as rain intensity and drop size distribution per time step and per event was investigated based on the above mentioned rain event definition. Pairwise Wilcoxon-tests revealed that higher rain intensity and larger drops were associated with the GWL "Low over the British Isles" (TB), whereas low rain intensities and less drops per interval were associated with the GWL "High over Central Europe

Searching Malware and Sources of Its Distribution in the Internet

Directory of Open Access Journals (Sweden)

L. L. Protsenko

2011-09-01

Full Text Available In the article is considered for the first time developed by the author algorithm of searching malware and sources of its distribution, based on published HijackThis logs in the Internet.

Design status of an intense 14 MeV neutron source for cancer therapy

CERN Document Server

Yao, Z E; Cheng, S W; Jia, W B

2002-01-01

Design and development of an intense 14 MeV neutron source for cancer therapy is in progress at the Institute of Nuclear Research of Lanzhou University. The neutrons from the T(d,n) sup 4 He reaction are produced by bombarding a rotating titanium tritide target with a 40 mA deuteron beam at 600 keV. The designed neutron yield is 8x10 sup 1 sup 2 n/s and the maximum dose rate at a 100 cm source-to-skin distance is 25 cGy/min. The HV terminal, accelerating column and HV power supply are enclosed inside a stainless steel pressure vessel containing 6 atm SF sub 6 gas to provide the electrical insulation.

Cyber-Physical Trade-Offs in Distributed Detection Networks

International Nuclear Information System (INIS)

Rao, Nageswara S.; Yao, David K.Y.; Chin, J.C.; Ma, Chris Y.T.; Madan, Rabinder

2010-01-01

We consider a network of sensors that measure the scalar intensity due to the background or a source combined with background, inside a two-dimensional monitoring area. The sensor measurements may be random due to the underlying nature of the source and background or due to sensor errors or both. The detection problem is to infer the presence of a source of unknown intensity and location based on sensor measurements. In the conventional approach, detection decisions are made at the individual sensors, which are then combined at the fusion center, for example using the majority rule. With increased communication and computation costs, we show that a more complex fusion algorithm based on measurements achieves better detection performance under smooth and non-smooth source intensity functions, Lipschitz conditions on probability ratios and a minimum packing number for the state-space. We show that these conditions for trade-offs between the cyber costs and physical detection performance are applicable for two detection problems: (i) point radiation sources amidst background radiation, and (ii) sources and background with Gaussian distributions.

Detailed seismic intensity in Morioka area; Moriokashi ni okeru shosai shindo bunpu

Energy Technology Data Exchange (ETDEWEB)

Saito, T; Yamamoto, H; Settai, H [Iwate University, Iwate (Japan). Faculty of Engineering; Yamada, T [Obayashi Road Construction Co. Ltd., Tokyo (Japan)

1996-10-01

To reveal a seismic intensity distribution in individual areas, a large-scale detailed seismic intensity survey was conducted in Morioka City through questionnaire, as to the Hokkaido Toho-oki (HE) earthquake occurred on October 4, 1994 with a record of seismic intensity 4 at Morioka, and the Sanriku Haruka-oki (SH) earthquake occurred on December 28, 1994 with a record of seismic intensity 5 at Morioka. A relationship was also examined between the seismic intensity distribution and the properties of shallow basement in Morioka City. The range of seismic intensity was from 2.9 to 4.6 and the difference was 1.7 in the case of HE earthquake, and the range was from 3.1 to 5.0 and the difference was 1.9 in the case of SH earthquake. There were large differences in the seismic intensity at individual points. Morioka City has different geological structures in individual areas. There were differences in the S-wave velocity in the surface layer ranging from 150 to 600 m/sec, which were measured using a plate hammering seismic source at 76 areas in Morioka City. These properties of surface layers were in harmony with the seismic intensity distribution obtained from the questionnaire. For the observation of short frequency microtremors at about 490 points in the city, areas with large amplitudes, mean maximum amplitudes of vertical motion components more than 0.1 mkine were distributed in north-western region and a part of southern region. 4 refs., 9 figs., 1 tab.

Statistical measurement of the gamma-ray source-count distribution as a function of energy

Science.gov (United States)

Zechlin, H.-S.; Cuoco, A.; Donato, F.; Fornengo, N.; Regis, M.

2017-01-01

Photon counts statistics have recently been proven to provide a sensitive observable for characterizing gamma-ray source populations and for measuring the composition of the gamma-ray sky. In this work, we generalize the use of the standard 1-point probability distribution function (1pPDF) to decompose the high-latitude gamma-ray emission observed with Fermi-LAT into: (i) point-source contributions, (ii) the Galactic foreground contribution, and (iii) a diffuse isotropic background contribution. We analyze gamma-ray data in five adjacent energy bands between 1 and 171 GeV. We measure the source-count distribution dN/dS as a function of energy, and demonstrate that our results extend current measurements from source catalogs to the regime of so far undetected sources. Our method improves the sensitivity for resolving point-source populations by about one order of magnitude in flux. The dN/dS distribution as a function of flux is found to be compatible with a broken power law. We derive upper limits on further possible breaks as well as the angular power of unresolved sources. We discuss the composition of the gamma-ray sky and capabilities of the 1pPDF method.

H- Ion Sources for High Intensity Proton Drivers

Energy Technology Data Exchange (ETDEWEB)

Johnson, Rolland Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dudnikov, Vadim [Muons, Inc., Batavia, IL (United States)

2015-02-20

Existing RF Surface Plasma Sources (SPS) for accelerators have specific efficiencies for H⁺ and H^- ion generation around 3 to 5 mA/cm² per kW, where about 50 kW of RF power is typically needed for 50 mA beam current production. The Saddle Antenna (SA) SPS described here was developed to improve H- ion production efficiency, reliability and availability for pulsed operation as used in the ORNL Spallation Neutron Source . At low RF power, the efficiency of positive ion generation in the plasma has been improved to 200 mA/cm² per kW of RF power at 13.56 MHz. Initial cesiation of the SPS was performed by heating cesium chromate cartridges by discharge as was done in the very first versions of the SPS. A small oven to decompose cesium compounds and alloys was developed and tested. After cesiation, the current of negative ions to the collector was increased from 1 mA to 10 mA with RF power 1.5 kW in the plasma (6 mm diameter emission aperture) and up to 30 mA with 4 kW RF power in the plasma and 250 Gauss longitudinal magnetic field. The ratio of electron current to negative ion current was improved from 30 to 2. Stable generation of H- beam without intensity degradation was demonstrated in the aluminum nitride (AlN) discharge chamber for 32 days at high discharge power in an RF SPS with an external antenna. Some modifications were made to improve the cooling and cesiation stability. The extracted collector current can be increased significantly by optimizing the longitudinal magnetic field in the discharge chamber. While this project demonstrated the advantages of the pulsed version of the SA RF SPS as an upgrade to the ORNL Spallation Neutron Source, it led to a possibility for upgrades to CW machines like the many cyclotrons used for commercial applications. Four appendices contain important details of the work carried out under this grant.

Decoy-state quantum key distribution with both source errors and statistical fluctuations

International Nuclear Information System (INIS)

Wang Xiangbin; Yang Lin; Peng Chengzhi; Pan Jianwei

2009-01-01

We show how to calculate the fraction of single-photon counts of the 3-intensity decoy-state quantum cryptography faithfully with both statistical fluctuations and source errors. Our results rely only on the bound values of a few parameters of the states of pulses.

Quasi-homogeneous partial coherent source modeling of multimode optical fiber output using the elementary source method

Science.gov (United States)

Fathy, Alaa; Sabry, Yasser M.; Khalil, Diaa A.

2017-10-01

Multimode fibers (MMF) have many applications in illumination, spectroscopy, sensing and even in optical communication systems. In this work, we present a model for the MMF output field assuming the fiber end as a quasi-homogenous source. The fiber end is modeled by a group of partially coherent elementary sources, spatially shifted and uncorrelated with each other. The elementary source distribution is derived from the far field intensity measurement, while the weighting function of the sources is derived from the fiber end intensity measurement. The model is compared with practical measurements for fibers with different core/cladding diameters at different propagation distances and for different input excitations: laser, white light and LED. The obtained results show normalized root mean square error less than 8% in the intensity profile in most cases, even when the fiber end surface is not perfectly cleaved. Also, the comparison with the Gaussian-Schell model results shows a better agreement with the measurement. In addition, the complex degree of coherence, derived from the model results, is compared with the theoretical predictions of the modified Van Zernike equation showing very good agreement, which strongly supports the assumption that the large core MMF could be considered as a quasi-homogenous source.

Turbulence in extended synchrotron radio sources. I. Polarization of turbulent sources. II. Power-spectral analysis

International Nuclear Information System (INIS)

Eilek, J.A.

1989-01-01

Recent theories of magnetohydrodynamic turbulence are used to construct microphysical turbulence models, with emphasis on models of anisotropic turbulence. These models have been applied to the determination of the emergent polarization from a resolved uniform source. It is found that depolarization alone is not a unique measure of the turbulence, and that the turblence will also affect the total-intensity distributions. Fluctuations in the intensity image can thus be employed to measure turbulence strength. In the second part, it is demonstrated that a power-spectral analysis of the total and polarized intensity images can be used to obtain the power spectra of the synchrotron emission. 81 refs

Distributed quantum computing with single photon sources

International Nuclear Information System (INIS)

Beige, A.; Kwek, L.C.

2005-01-01

Full text: Distributed quantum computing requires the ability to perform nonlocal gate operations between the distant nodes (stationary qubits) of a large network. To achieve this, it has been proposed to interconvert stationary qubits with flying qubits. In contrast to this, we show that distributed quantum computing only requires the ability to encode stationary qubits into flying qubits but not the conversion of flying qubits into stationary qubits. We describe a scheme for the realization of an eventually deterministic controlled phase gate by performing measurements on pairs of flying qubits. Our scheme could be implemented with a linear optics quantum computing setup including sources for the generation of single photons on demand, linear optics elements and photon detectors. In the presence of photon loss and finite detector efficiencies, the scheme could be used to build large cluster states for one way quantum computing with a high fidelity. (author)

CMP reflection imaging via interferometry of distributed subsurface sources

Science.gov (United States)

Kim, D.; Brown, L. D.; Quiros, D. A.

2015-12-01

The theoretical foundations of recovering body wave energy via seismic interferometry are well established. However in practice, such recovery remains problematic. Here, synthetic seismograms computed for subsurface sources are used to evaluate the geometrical combinations of realistic ambient source and receiver distributions that result in useful recovery of virtual body waves. This study illustrates how surface receiver arrays that span a limited distribution suite of sources, can be processed to reproduce virtual shot gathers that result in CMP gathers which can be effectively stacked with traditional normal moveout corrections. To verify the feasibility of the approach in practice, seismic recordings of 50 aftershocks following the magnitude of 5.8 Virginia earthquake occurred in August, 2011 have been processed using seismic interferometry to produce seismic reflection images of the crustal structure above and beneath the aftershock cluster. Although monotonic noise proved to be problematic by significantly reducing the number of usable recordings, the edited dataset resulted in stacked seismic sections characterized by coherent reflections that resemble those seen on a nearby conventional reflection survey. In particular, "virtual" reflections at travel times of 3 to 4 seconds suggest reflector sat approximately 7 to 12 km depth that would seem to correspond to imbricate thrust structures formed during the Appalachian orogeny. The approach described here represents a promising new means of body wave imaging of 3D structure that can be applied to a wide array of geologic and energy problems. Unlike other imaging techniques using natural sources, this technique does not require precise source locations or times. It can thus exploit aftershocks too small for conventional analyses. This method can be applied to any type of microseismic cloud, whether tectonic, volcanic or man-made.

Correlated Sources in Distributed Networks--Data Transmission, Common Information Characterization and Inferencing

Science.gov (United States)

Liu, Wei

2011-01-01

Correlation is often present among observations in a distributed system. This thesis deals with various design issues when correlated data are observed at distributed terminals, including: communicating correlated sources over interference channels, characterizing the common information among dependent random variables, and testing the presence of…

Spatial Distributions of Tropical Cyclone Tornadoes by Intensity and Size Characteristics

Directory of Open Access Journals (Sweden)

Todd W. Moore

2017-08-01

Full Text Available Tropical cyclones that make landfall often spawn tornadoes. Previous studies have shown that these tornadoes are not uniformly distributed in the United States or in the tropical cyclone environment. They show that tornadoes tend to occur relatively close to the coastline and that they tend to cluster to the east-of-center in the tropical cyclone environment, particularly in the northeast and east-of-center quadrants. This study contributes to these studies by analyzing the spatial distributions of tropical cyclone tornadoes by intensity, path length, path width, and the damage potential index. The analyses confirm that most tornadoes occur relatively close to the coastline, but show that stronger tornadoes with larger paths are disproportionately common farther inland. They also confirm that the highest amount of activity is located within the northeast and east-of-center quadrants and show that the most potentially damaging tornadoes cluster in a sub region near the intersection of these two quadrants.

Asymmetries in angular distributions of nucleon emission intensity in high energy hadron-nucleus collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1982-01-01

Asymmetry in nucleon emission intensity angular distributions relatively to the hadron deflection plane and to two planes normal to it and related to it uniquely is analyzed, using appropriate experimental data on pion-xenon nucleus collisions at 3.5 GeV/c momentum. Quantative characteristics of the asymmetries found are presented in tables and on figures

A high intensity Stern-Gerlach polarized hydrogen source for the Munich MP-Tandem laboratory using ECR ionization and charge exchange in cesium vapor

International Nuclear Information System (INIS)

Hertenberger, R.; Eisermann, Y.; Metz, A.; Schiemenz, P.; Graw, G.

2001-01-01

The 14 year old Lamb-Shift hydrogen source of the Munich Tandem laboratory is presently replaced by a newly developed Stern-Gerlach type atomic beam source (ABS) with electron-cyclotron-resonance (ECR) ionization and subsequent double charge exchange in a supersonic cesium vapor jet target. The atomic beam source provides an intensity of 6.4*10 16 atoms/sec of polarized hydrogen and of about 5*10 16 atoms/sec of polarized deuterium. Beam intensities larger than 100 μA were observed for positive H-vector + and D-vector + ion beams after ECR ionization and intensities larger than 10 μA for negative D-vector - ion beams in three magnetic substates

The quick convolution of galaxy profiles, with application to power-law intensity distributions

International Nuclear Information System (INIS)

Bailey, M.E.; Sparks, W.B.

1983-01-01

The two-dimensional convolution of a circularly symmetric galaxy model with a Gaussian point-spread function of dispersion σ reduces to a single integral. This is solved analytically for models with power-law intensity distributions and results are given which relate the apparent core radius to σ and the power-law index k. The convolution integral is also simplified for the case of a point-spread function corresponding to a circular aperture. Models of galactic nuclei with stellar density cusps can only be distinguished from alternatives with small core radii if both the brightness and seeing profiles are measured accurately. The results are applied to data on the light distribution at the Galactic Centre. (author)

Distributed Remote Vector Gaussian Source Coding for Wireless Acoustic Sensor Networks

DEFF Research Database (Denmark)

Zahedi, Adel; Østergaard, Jan; Jensen, Søren Holdt

2014-01-01

In this paper, we consider the problem of remote vector Gaussian source coding for a wireless acoustic sensor network. Each node receives messages from multiple nodes in the network and decodes these messages using its own measurement of the sound field as side information. The node’s measurement...... and the estimates of the source resulting from decoding the received messages are then jointly encoded and transmitted to a neighboring node in the network. We show that for this distributed source coding scenario, one can encode a so-called conditional sufficient statistic of the sources instead of jointly...

Production of intensive negative lithium beam with caesium sputter-type ion source

Science.gov (United States)

Lobanov, Nikolai R.

2018-01-01

Compounds of lithium oxide, hydroxide and carbonate, mixed with silver, were prepared for use as a cathode in caesium-sputter ion source. The intention was to determine the procedure which would produce the highest intensity negative lithium beams over extended period and with maximum stability. The chemical composition and properties of the samples were analysed using mass-spectrometry, optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analyses (EDX) and Raman spectroscopy. These analyses showed that the chemical transformations with components resulted from pressing, storage and bake out were qualitatively in agreement with expectations. Intensive negative lithium ion beams >1 μA were delivered using cathodes fabricated from materials with multicomponent chemical composition when the following conditions were met: (i) use of components with moderate enthalpy of formation; (ii) low moisture content at final stage of cathode production and (iii) small concentration of water molecules in hydrate phase in the cathode mixture.

Design of TIR collimating lens for ordinary differential equation of extended light source

Science.gov (United States)

Zhan, Qianjing; Liu, Xiaoqin; Hou, Zaihong; Wu, Yi

2017-10-01

The source of LED has been widely used in our daily life. The intensity angle distribution of single LED is lambert distribution, which does not satisfy the requirement of people. Therefore, we need to distribute light and change the LED's intensity angle distribution. The most commonly method to change its intensity angle distribution is the free surface. Generally, using ordinary differential equations to calculate free surface can only be applied in a point source, but it will lead to a big error for the expand light. This paper proposes a LED collimating lens based on the ordinary differential equation, combined with the LED's light distribution curve, and adopt the method of calculating the center gravity of the extended light to get the normal vector. According to the law of Snell, the ordinary differential equations are constructed. Using the runge-kutta method for solution of ordinary differential equation solution, the curve point coordinates are gotten. Meanwhile, the edge point data of lens are imported into the optical simulation software TracePro. Based on 1mm×1mm single lambert body for light conditions, The degrees of collimating light can be close to +/-3. Furthermore, the energy utilization rate is higher than 85%. In this paper, the point light source is used to calculate partial differential equation method and compared with the simulation of the lens, which improve the effect of 1 degree of collimation.

Use of frozen stress in extracting stress intensity factor distributions in three dimensional cracked body problems

Science.gov (United States)

Smith, C. W.

1992-01-01

The adaptation of the frozen stress photoelastic method to the determination of the distribution of stress intensity factors in three dimensional problems is briefly reviewed. The method is then applied to several engineering problems of practical significance.

A "looming bias" in spatial hearing? Effects of acoustic intensity and spectrum on categorical sound source localization.

Science.gov (United States)

McCarthy, Lisa; Olsen, Kirk N

2017-01-01

Continuous increases of acoustic intensity (up-ramps) can indicate a looming (approaching) sound source in the environment, whereas continuous decreases of intensity (down-ramps) can indicate a receding sound source. From psychoacoustic experiments, an "adaptive perceptual bias" for up-ramp looming tonal stimuli has been proposed (Neuhoff, 1998). This theory postulates that (1) up-ramps are perceptually salient because of their association with looming and potentially threatening stimuli in the environment; (2) tonal stimuli are perceptually salient because of an association with single and potentially threatening biological sound sources in the environment, relative to white noise, which is more likely to arise from dispersed signals and nonthreatening/nonbiological sources (wind/ocean). In the present study, we extrapolated the "adaptive perceptual bias" theory and investigated its assumptions by measuring sound source localization in response to acoustic stimuli presented in azimuth to imply looming, stationary, and receding motion in depth. Participants (N = 26) heard three directions of intensity change (up-ramps, down-ramps, and steady state, associated with looming, receding, and stationary motion, respectively) and three levels of acoustic spectrum (a 1-kHz pure tone, the tonal vowel /ә/, and white noise) in a within-subjects design. We first hypothesized that if up-ramps are "perceptually salient" and capable of eliciting adaptive responses, then they would be localized faster and more accurately than down-ramps. This hypothesis was supported. However, the results did not support the second hypothesis. Rather, the white-noise and vowel conditions were localized faster and more accurately than the pure-tone conditions. These results are discussed in the context of auditory and visual theories of motion perception, auditory attentional capture, and the spectral causes of spatial ambiguity.

Gas source localization and gas distribution mapping with a micro-drone

International Nuclear Information System (INIS)

Neumann, Patrick P.

2013-01-01

The objective of this Ph.D. thesis is the development and validation of a VTOL-based (Vertical Take Off and Landing) micro-drone for the measurement of gas concentrations, to locate gas emission sources, and to build gas distribution maps. Gas distribution mapping and localization of a static gas source are complex tasks due to the turbulent nature of gas transport under natural conditions and becomes even more challenging when airborne. This is especially so, when using a VTOL-based micro-drone that induces disturbances through its rotors, which heavily affects gas distribution. Besides the adaptation of a micro-drone for gas concentration measurements, a novel method for the determination of the wind vector in real-time is presented. The on-board sensors for the flight control of the micro-drone provide a basis for the wind vector calculation. Furthermore, robot operating software for controlling the micro-drone autonomously is developed and used to validate the algorithms developed within this Ph.D. thesis in simulations and real-world experiments. Three biologically inspired algorithms for locating gas sources are adapted and developed for use with the micro-drone: the surge-cast algorithm (a variant of the silkworm moth algorithm), the zigzag / dung beetle algorithm, and a newly developed algorithm called ''pseudo gradient algorithm''. The latter extracts from two spatially separated measuring positions the information necessary (concentration gradient and mean wind direction) to follow a gas plume to its emission source. The performance of the algorithms is evaluated in simulations and real-world experiments. The distance overhead and the gas source localization success rate are used as main performance criteria for comparing the algorithms. Next, a new method for gas source localization (GSL) based on a particle filter (PF) is presented. Each particle represents a weighted hypothesis of the gas source position. As a first step, the PF-based GSL algorithm

Gas source localization and gas distribution mapping with a micro-drone

Energy Technology Data Exchange (ETDEWEB)

Neumann, Patrick P.

2013-07-01

The objective of this Ph.D. thesis is the development and validation of a VTOL-based (Vertical Take Off and Landing) micro-drone for the measurement of gas concentrations, to locate gas emission sources, and to build gas distribution maps. Gas distribution mapping and localization of a static gas source are complex tasks due to the turbulent nature of gas transport under natural conditions and becomes even more challenging when airborne. This is especially so, when using a VTOL-based micro-drone that induces disturbances through its rotors, which heavily affects gas distribution. Besides the adaptation of a micro-drone for gas concentration measurements, a novel method for the determination of the wind vector in real-time is presented. The on-board sensors for the flight control of the micro-drone provide a basis for the wind vector calculation. Furthermore, robot operating software for controlling the micro-drone autonomously is developed and used to validate the algorithms developed within this Ph.D. thesis in simulations and real-world experiments. Three biologically inspired algorithms for locating gas sources are adapted and developed for use with the micro-drone: the surge-cast algorithm (a variant of the silkworm moth algorithm), the zigzag / dung beetle algorithm, and a newly developed algorithm called ''pseudo gradient algorithm''. The latter extracts from two spatially separated measuring positions the information necessary (concentration gradient and mean wind direction) to follow a gas plume to its emission source. The performance of the algorithms is evaluated in simulations and real-world experiments. The distance overhead and the gas source localization success rate are used as main performance criteria for comparing the algorithms. Next, a new method for gas source localization (GSL) based on a particle filter (PF) is presented. Each particle represents a weighted hypothesis of the gas source position. As a first step, the PF

Gas source localization and gas distribution mapping with a micro-drone

Energy Technology Data Exchange (ETDEWEB)

Neumann, Patrick P.

2013-07-01

The objective of this Ph.D. thesis is the development and validation of a VTOL-based (Vertical Take Off and Landing) micro-drone for the measurement of gas concentrations, to locate gas emission sources, and to build gas distribution maps. Gas distribution mapping and localization of a static gas source are complex tasks due to the turbulent nature of gas transport under natural conditions and becomes even more challenging when airborne. This is especially so, when using a VTOL-based micro-drone that induces disturbances through its rotors, which heavily affects gas distribution. Besides the adaptation of a micro-drone for gas concentration measurements, a novel method for the determination of the wind vector in real-time is presented. The on-board sensors for the flight control of the micro-drone provide a basis for the wind vector calculation. Furthermore, robot operating software for controlling the micro-drone autonomously is developed and used to validate the algorithms developed within this Ph.D. thesis in simulations and real-world experiments. Three biologically inspired algorithms for locating gas sources are adapted and developed for use with the micro-drone: the surge-cast algorithm (a variant of the silkworm moth algorithm), the zigzag / dung beetle algorithm, and a newly developed algorithm called ''pseudo gradient algorithm''. The latter extracts from two spatially separated measuring positions the information necessary (concentration gradient and mean wind direction) to follow a gas plume to its emission source. The performance of the algorithms is evaluated in simulations and real-world experiments. The distance overhead and the gas source localization success rate are used as main performance criteria for comparing the algorithms. Next, a new method for gas source localization (GSL) based on a particle filter (PF) is presented. Each particle represents a weighted hypothesis of the gas source position. As a first step, the PF-based GSL algorithm

A New Method for the 2D DOA Estimation of Coherently Distributed Sources

Directory of Open Access Journals (Sweden)

Liang Zhou

2014-03-01

Full Text Available The purpose of this paper is to develop a new technique for estimating the two- dimensional (2D direction-of-arrivals (DOAs of coherently distributed (CD sources, which can estimate effectively the central azimuth and central elevation of CD sources at the cost of less computational cost. Using the special L-shape array, a new approach for parametric estimation of CD sources is proposed. The proposed method is based on two rotational invariance relations under small angular approximation, and estimates two rotational matrices which depict the relations, using propagator technique. And then the central DOA estimations are obtained by utilizing the primary diagonal elements of two rotational matrices. Simulation results indicate that the proposed method can exhibit a good performance under small angular spread and be applied to the multisource scenario where different sources may have different angular distribution shapes. Without any peak-finding search and the eigendecomposition of the high-dimensional sample covariance matrix, the proposed method has significantly reduced the computational cost compared with the existing methods, and thus is beneficial to real-time processing and engineering realization. In addition, our approach is also a robust estimator which does not depend on the angular distribution shape of CD sources.

Reinvestigation of the charge density distribution in arc discharge fusion system

Energy Technology Data Exchange (ETDEWEB)

Sheng, Lin Horng; Yee, Lee Kim; Nan, Phua Yeong; Thung, Yong Yun; Khok, Yong Thian; Rahman, Faidz Abd [Centre of Photonics and Advance Material, Universiti Tunku Abdul Rahman Kuala Lumpur (Malaysia)

2015-04-24

A continual arc discharge system has been setup and the light intensity of arc discharge has been profiled. The mathematical model of local energy density distribution in arc discharge fusion has been simulated which is in good qualitative agreement with light intensity profile of arc discharge in the experiments. Eventually, the local energy density distribution of arc discharge system is able to be precisely manipulated to act as heat source in the fabrication of fused fiber devices.

Reinvestigation of the charge density distribution in arc discharge fusion system

International Nuclear Information System (INIS)

Sheng, Lin Horng; Yee, Lee Kim; Nan, Phua Yeong; Thung, Yong Yun; Khok, Yong Thian; Rahman, Faidz Abd

2015-01-01

A continual arc discharge system has been setup and the light intensity of arc discharge has been profiled. The mathematical model of local energy density distribution in arc discharge fusion has been simulated which is in good qualitative agreement with light intensity profile of arc discharge in the experiments. Eventually, the local energy density distribution of arc discharge system is able to be precisely manipulated to act as heat source in the fabrication of fused fiber devices

Perceived loudness of spatially distributed sound sources

DEFF Research Database (Denmark)

Song, Woo-keun; Ellermeier, Wolfgang; Minnaar, Pauli

2005-01-01

psychoacoustic attributes into account. Therefore, a method for deriving loudness maps was developed in an earlier study [Song, Internoise2004, paper 271]. The present experiment investigates to which extent perceived loudness depends on the distribution of individual sound sources. Three loudspeakers were...... positioned 1.5 m from the centre of the listener’s head, one straight ahead, and two 10 degrees to the right and left, respectively. Six participants matched the loudness of either one, or two simultaneous sounds (narrow-band noises with 1-kHz, and 3.15-kHz centre frequencies) to a 2-kHz, 60-dB SPL narrow......-band noise placed in the frontal loudspeaker. The two sounds were either originating from the central speaker, or from the two offset loudspeakers. It turned out that the subjects perceived the noises to be softer when they were distributed in space. In addition, loudness was calculated from the recordings...

Reconstruction of far-field tsunami amplitude distributions from earthquake sources

Science.gov (United States)

Geist, Eric L.; Parsons, Thomas E.

2016-01-01

The probability distribution of far-field tsunami amplitudes is explained in relation to the distribution of seismic moment at subduction zones. Tsunami amplitude distributions at tide gauge stations follow a similar functional form, well described by a tapered Pareto distribution that is parameterized by a power-law exponent and a corner amplitude. Distribution parameters are first established for eight tide gauge stations in the Pacific, using maximum likelihood estimation. A procedure is then developed to reconstruct the tsunami amplitude distribution that consists of four steps: (1) define the distribution of seismic moment at subduction zones; (2) establish a source-station scaling relation from regression analysis; (3) transform the seismic moment distribution to a tsunami amplitude distribution for each subduction zone; and (4) mix the transformed distribution for all subduction zones to an aggregate tsunami amplitude distribution specific to the tide gauge station. The tsunami amplitude distribution is adequately reconstructed for four tide gauge stations using globally constant seismic moment distribution parameters established in previous studies. In comparisons to empirical tsunami amplitude distributions from maximum likelihood estimation, the reconstructed distributions consistently exhibit higher corner amplitude values, implying that in most cases, the empirical catalogs are too short to include the largest amplitudes. Because the reconstructed distribution is based on a catalog of earthquakes that is much larger than the tsunami catalog, it is less susceptible to the effects of record-breaking events and more indicative of the actual distribution of tsunami amplitudes.

Measurement of relative intensities of L-shell X-rays of some heavy elements using Cd-109 radioisotope source

International Nuclear Information System (INIS)

Darko, J.B.; Tetteh, G.K.

1992-01-01

The relative L-shell x-ray intensities of Sm, W, Ir, Au, Hg, Pb and U were measured using a Cd-109 radioisotope source and a Si(Li) detector. The measured relative intensities were compared with the theoretically calculated values due to Scofield, computed for the present excitation energy of 22.6 keV. The experimental results were found to agree with theory in most cases. (author)

Measurement of relative intensities of L-shell X-rays of some heavy elements using Cd-109 radioisotope source

Energy Technology Data Exchange (ETDEWEB)

Darko, J.B.; Tetteh, G.K. (Ghana Univ., Legon (Ghana). Dept. of Physics)

The relative L-shell x-ray intensities of Sm, W, Ir, Au, Hg, Pb and U were measured using a Cd-109 radioisotope source and a Si(Li) detector. The measured relative intensities were compared with the theoretically calculated values due to Scofield, computed for the present excitation energy of 22.6 keV. The experimental results were found to agree with theory in most cases. (author).

Intense neutron sources for cancer treatment

International Nuclear Information System (INIS)

Anon.

1977-01-01

Significant progress has been made in the development of small, solid-target, pulsed neutron sources for nuclear weapons applications. The feasibility of using this type of neutron source for cancer treatment is discussed. Plans for fabrication and testing of such a source is briefly described

Ion beam exposure apparatus using a liquid metal source

International Nuclear Information System (INIS)

Komuro, M.

1982-01-01

A field effect liquid metal ion source is described. The current-voltage characteristics, the angular intensity distribution and the total energy distribution were measured for gallium, gold and lead sources. The results are presented and the effect of space charge on the emission current is discussed. Optimum working conditions for the use of the ion sources in probe formation are derived. On the basis of the experimental results, an apparatus operating at 50 kV or less was designed. Details of the design, which includes a triode ion gun and an einzel lens, are given together with preliminary results of pattern delineation with the apparatus. (Auth.)

Spatial variation and sources of polycyclic aromatic hydrocarbons influenced by intensive land use in an urbanized river network of East China.

Science.gov (United States)

Bi, Chunjuan; Wang, Xueping; Jia, Jinpu; Chen, Zhenlou

2018-06-15

The concentrations and distribution of polycyclic aromatic hydrocarbons (PAHs) in urbanized river networks are strongly influenced by intensive land use, industrial activities and population density. The spatial variations and their influencing factors of 16 priority PAHs were investigated in surface water, suspended particulate matter (SPM) and sediments among areas under different intensive land uses (industrial areas, agricultural areas, inner city, suburban towns and island areas) in the Shanghai river network, East China. Source apportionment was carried out using isomer ratios of PAHs and Positive Matrix Factorization (PMF). Total concentrations of 16 PAHs ranged from 105.2 to 400.5 ng/L, 108.1 to 1058.8 ng/L and 104.4 to 19,480.0 ng/g in water, SPM and sediments, respectively. The concentrations of PAHs in SPM and sediments varied significantly among areas (p natural gas combustion in water and SPM, and vehicular emissions in sediments. Vehicular emissions were the strongest contributors in SPM and sediments of the inner city, indicating the strong influence of vehicular transportation to PAHs pollution in the urbanized river network. Copyright © 2018 Elsevier B.V. All rights reserved.

Boosting up quantum key distribution by learning statistics of practical single-photon sources

International Nuclear Information System (INIS)

Adachi, Yoritoshi; Yamamoto, Takashi; Koashi, Masato; Imoto, Nobuyuki

2009-01-01

We propose a simple quantum-key-distribution (QKD) scheme for practical single-photon sources (SPSs), which works even with a moderate suppression of the second-order correlation g (2) of the source. The scheme utilizes a passive preparation of a decoy state by monitoring a fraction of the signal via an additional beam splitter and a detector at the sender's side to monitor photon-number splitting attacks. We show that the achievable distance increases with the precision with which the sub-Poissonian tendency is confirmed in higher photon-number distribution of the source, rather than with actual suppression of the multiphoton emission events. We present an example of the secure key generation rate in the case of a poor SPS with g (2) =0.19, in which no secure key is produced with the conventional QKD scheme, and show that learning the photon-number distribution up to several numbers is sufficient for achieving almost the same distance as that of an ideal SPS.

Neutron beam design for low intensity neutron and gamma-ray radioscopy using small neutron sources

CERN Document Server

Matsumoto, T

2003-01-01

Two small neutron sources of sup 2 sup 5 sup 2 Cf and sup 2 sup 4 sup 1 Am-Be radioisotopes were used for design of neutron beams applicable to low intensity neutron and gamma ray radioscopy (LINGR). In the design, Monte Carlo code (MCNP) was employed to generate neutron and gamma ray beams suited to LINGR. With a view to variable neutron spectrum and neutron intensity, various arrangements were first examined, and neutron-filter, gamma-ray shield and beam collimator were verified. Monte Carlo calculations indicated that with a suitable filter-shield-collimator arrangement, thermal neutron beam of 3,900 ncm sup - sup 2 s sup - sup 1 with neutron/gamma ratio of 7x10 sup 7 , and 25 ncm sup - sup 2 s sup - sup 1 with very large neutron/gamma ratio, respectively, could be produced by using sup 2 sup 5 sup 2 Cf(122 mu g) and a sup 2 sup 4 sup 1 Am-Be(37GBq)radioisotopes at the irradiation port of 35 cm from the neutron sources.

Transfer standard for the spectral density of relative intensity noise of optical fiber sources near 1550 nm

Energy Technology Data Exchange (ETDEWEB)

Obarski, Gregory E.; Splett, Jolene D.

2001-06-01

We have developed a transfer standard for the spectral density of relative intensity noise (RIN) of optical fiber sources near 1550 nm. Amplified spontaneous emission (ASE) from an erbium-doped fiber amplifier (EDFA), when it is optically filtered over a narrow band ({lt}5 nm), yields a stable RIN spectrum that is practically constant to several tens of gigahertz. The RIN is calculated from the power spectral density as measured with a calibrated optical spectrum analyzer. For a typical device it is {minus}110 dB/Hz, with uncertainty {le}0.12 dB/Hz. The invariance of the RIN under attenuation yields a considerable dynamic range with respect to rf noise levels. Results are compared with those from a second method that uses a distributed-feedback laser (DFB) that has a Poisson-limited RIN. Application of each method to the same RIN measurement system yields frequency-dependent calibration functions that, when they are averaged, differ by {le}0.2 dB. {copyright} 2001 Optical Society of America

On the potential of using peculiarities of the protein intrinsic disorder distribution in mitochondrial cytochrome b to identify the source of animal meats

Science.gov (United States)

Yacoub, Haitham A.; Sadek, Mahmoud A.; Uversky, Vladimir N.

2017-01-01

ABSTRACT This study was conducted to identify the source of animal meat based on the peculiarities of protein intrinsic disorder distribution in mitochondrial cytochrome b (mtCyt-b). The analysis revealed that animal and avian species can be discriminated based on the proportions of the two groups of residues, Leu+Ile, and Ser+Pro+Ala, in the amino acid sequences of their mtCyt-b. Although levels of the overall intrinsic disorder in mtCyt-b is not very high, the peculiarities of disorder distribution within the sequences of mtCyt-b from different species varies in a rather specific way. In fact, positions and intensities of disorder/flexibility “signals” in the corresponding disorder profiles are relatively unique for avian and animal species. Therefore, it is possible to devise a set of simple rules based on the peculiarities of disorder profiles of their mtCyt-b proteins to discriminate among species. This intrinsic disorder-based analysis represents a new technique that could be used to provide a promising solution for identification of the source of meats. PMID:28331777

Floodplains as a source of fine sediment in grazed landscapes: tracing the source of suspended sediment in the headwaters of an intensively managed agricultural landscape

Science.gov (United States)

Yu, M.; Rhoads, B. L.; Stumpf, A.

2017-12-01

The flux of fine sediment within agricultural watersheds is an important factor determining the environmental quality of streams and rivers. Despite this importance, the contributions of sediment sources to suspended sediment loads within intensively managed agricultural watersheds remain poorly understood. This study assesses the provenance of fine suspended sediment in the headwater portion of a river flowing through an agricultural landscape in Illinois. Sediment source samples were collected from five potential sources: streambanks, forested floodplain, grassland, and grazed floodplains. Event-based and aggregated suspended sediment samples were collected from the stream at the watershed outlet. Quantitative geochemical fingerprinting techniques and a mixing model were employed to estimate the relative contributions of sediment from five potential sources to the suspended sediment loads. Organic matter content, trace elements, and fallout radionuclides were used as potential tracers. Principal Component analysis was employed to complement the results and Monte Carlo random sampling routine was used to test the uncertainty in estimated contributions of sources to in-stream sediment loads. Results indicate that the majority of suspended sediment is derived from streambanks and grazed floodplains. Erosion of the floodplain both by surface runoff and by streambank erosion from lateral channel migration contributes to the production of fine sediment within the stream system. These results suggest that human activities, in this case grazing, have converted portions of floodplains, normally net depositional environments, into sources of fine sediments. Efforts to reduce fluxes of fine sediment in this intensively managed landscape should focus on degraded floodplain surfaces and eroding channel banks within heavily grazed reaches of the stream.

Distribution and Source Identification of Pb Contamination in industrial soil

Science.gov (United States)

Ko, M. S.

2017-12-01

INTRODUCTION Lead (Pb) is toxic element that induce neurotoxic effect to human, because competition of Pb and Ca in nerve system. Lead is classified as a chalophile element and galena (PbS) is the major mineral. Although the Pb is not an abundant element in nature, various anthropogenic source has been enhanced Pb enrichment in the environment after the Industrial Revolution. The representative anthropogenic sources are batteries, paint, mining, smelting, and combustion of fossil fuel. Isotope analysis widely used to identify the Pb contamination source. The Pb has four stable isotopes that are 208Pb, 207Pb, 206Pb, and 204Pb in natural. The Pb is stable isotope and the ratios maintain during physical and chemical fractionation. Therefore, variations of Pb isotope abundance and relative ratios could imply the certain Pb contamination source. In this study, distributions and isotope ratios of Pb in industrial soil were used to identify the Pb contamination source and dispersion pathways. MATERIALS AND METHODS Soil samples were collected at depth 0­-6 m from an industrial area in Korea. The collected soil samples were dried and sieved under 2 mm. Soil pH, aqua-regia digestion and TCLP carried out using sieved soil sample. The isotope analysis was carried out to determine the abundance of Pb isotope. RESULTS AND DISCUSSION The study area was developed land for promotion of industrial facilities. The study area was forest in 1980, and the satellite image show the alterations of land use with time. The variations of land use imply the possibilities of bringing in external contaminated soil. The Pb concentrations in core samples revealed higher in lower soil compare with top soil. Especially, 4 m soil sample show highest Pb concentrations that are approximately 1500 mg/kg. This result indicated that certain Pb source existed at 4 m depth. CONCLUSIONS This study investigated the distribution and source identification of Pb in industrial soil. The land use and Pb

Determining profile of dose distribution for PD-103 brachytherapy source

International Nuclear Information System (INIS)

Berkay, Camgoz; Mehmet, N. Kumru; Gultekin, Yegin

2006-01-01

Full text: Brachytherapy is a particular radiotherapy for cancer treatments. By destructing cancerous cells using radiation, the treatment proceeded. When alive tissues are subject it is hazardous to study experimental. For brachytherapy sources generally are studied as theoretical using computer simulation. General concept of the treatment is to locate the radioactive source into cancerous area of related tissue. In computer studies Monte Carlo mathematical method that is in principle based on random number generations, is used. Palladium radioisotope is LDR (Low radiation Dose Rate) source. Main radioactive material was coated with titanium cylinder with 3mm length, 0.25 mm radius. There are two parts of Pd-103 in the titanium cylinder. It is impossible to investigate differential effects come from two part as experimental. Because the source dimensions are small compared with measurement distances. So there is only simulation method. In dosimetric studies it is aimed to determine absorbed dose distribution in tissue as radial and angular. In nuclear physics it is obligation to use computer based methods for researchers. Radiation studies have hazards for scientist and people interacted with radiation. When hazard exceed over recommended limits or physical conditions are not suitable (long work time, non economical experiments, inadequate sensitivity of materials etc.) it is unavoidable to simulate works and experiments before practices of scientific methods in life. In medical area, usage of radiation is required computational work for cancer treatments. Some computational studies are routine in clinics and other studies have scientific development purposes. In brachytherapy studies there are significant differences between experimental measurements and theoretical (computer based) output data. Errors of data taken from experimental studies are larger than simulation values errors. In design of a new brachytherapy source it is important to consider detailed

High-intensity sources for light ions

International Nuclear Information System (INIS)

Leung, K.N.

1995-10-01

The use of the multicusp plasma generator as a source of light ions is described. By employing radio-frequency induction discharge, the performance of the multicusp source is greatly improved, both in lifetime and in high brightness H + and H - beam production. A new technique for generating multiply-charged ions in this type of ion source is also presented

Growth and content of Spirulina platensis biomass chlorophyll cultivated at different values of light intensity and temperature using different nitrogen sources

Directory of Open Access Journals (Sweden)

Eliane Dalva Godoy Danesi

2011-03-01

Full Text Available The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5ºC and light intensities from 15 to 69 µmol photons m-2 s-1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation performed with both sources of nitrogen, it was possible to obtain satisfactory adjustments to relate the dependent variables to the independent variables. The best results were achieved at temperature of 30ºC, at light intensity of 60 µmol photons m-2s-1, for cell growth, with cell productivity of approximately 95 mg L-1 d-1 in cultivations with urea. For the chlorophyll biomass content, the most adequate light intensity was 24 µmol photons m-2 s-1.

Local influence of south-east France topography and land cover on the distribution and characteristics of intense rainfall cells

Science.gov (United States)

Renard, Florent

2017-04-01

The Greater Lyon area is strongly built up, grouping 58 communes and a population of 1.3 million in approximately 500 km2. The flood risk is high as the territory is crossed by two large watercourses and by streams with torrential flow. Floods may also occur in case of runoff after heavy rain or because of a rise in the groundwater level. The whole territory can therefore be affected, and it is necessary to possess in-depth knowledge of the depths, causes and consequences of rainfall to achieve better management of precipitation in urban areas and to reduce flood risk. This study is thus focused on the effects of topography and land cover on the occurrence, intensity and area of intense rainfall cells. They are identified by local radar meteorology (C-band) combined with a processing algorithm running in a geographic information system (GIS) which identified 109,979 weighted mean centres of them in a sample composed of the five most intense rainfall events from 2001 to 2005. First, analysis of spatial distribution at an overall scale is performed, completed by study at a more detailed scale. The results show that the distribution of high-intensity rainfall cells is spread in cluster form. Subsequently, comparison of intense rainfall cells with the topography shows that cell density is closely linked with land slope but that, above all, urbanised zones feature nearly twice as many rainfall cells as farm land or forest, with more intense intensity.

Development of unfolding method to obtain pin-wise source strength distribution from PWR spent fuel assembly measurement

International Nuclear Information System (INIS)

Sitompul, Yos Panagaman; Shin, Hee-Sung; Park, Se-Hwan; Oh, Jong Myeong; Seo, Hee; Kim, Ho Dong

2013-01-01

An unfolding method has been developed to obtain a pin-wise source strength distribution of a 14 × 14 pressurized water reactor (PWR) spent fuel assembly. Sixteen measured gamma dose rates at 16 control rod guide tubes of an assembly are unfolded to 179 pin-wise source strengths of the assembly. The method calculates and optimizes five coefficients of the quadratic fitting function for X-Y source strength distribution, iteratively. The pin-wise source strengths are obtained at the sixth iteration, with a maximum difference between two sequential iterations of about 0.2%. The relative distribution of pin-wise source strength from the unfolding is checked using a comparison with the design code (Westinghouse APA code). The result shows that the relative distribution from the unfolding and design code is consistent within a 5% difference. The absolute value of the pin-wise source strength is also checked by reproducing the dose rates at the measurement points. The result shows that the pin-wise source strengths from the unfolding reproduce the dose rates within a 2% difference. (author)

Sources and distribution of anthropogenic radionuclides in different marine environments

International Nuclear Information System (INIS)

Holm, E.

1997-01-01

The knowledge of the distribution in time and space radiologically important radionuclides from different sources in different marine environments is important for assessment of dose commitment following controlled or accidental releases and for detecting eventual new sources. Present sources from nuclear explosion tests, releases from nuclear facilities and the Chernobyl accident provide a tool for such studies. The different sources can be distinguished by different isotopic and radionuclide composition. Results show that radiocaesium behaves rather conservatively in the south and north Atlantic while plutonium has a residence time of about 8 years. On the other hand enhanced concentrations of plutonium in surface waters in arctic regions where vertical mixing is small and iceformation plays an important role. Significantly increased concentrations of plutonium are also found below the oxic layer in anoxic basins due to geochemical concentration. (author)

GIS Based Distributed Runoff Predictions in Variable Source Area Watersheds Employing the SCS-Curve Number

Science.gov (United States)

Steenhuis, T. S.; Mendoza, G.; Lyon, S. W.; Gerard Marchant, P.; Walter, M. T.; Schneiderman, E.

2003-04-01

Because the traditional Soil Conservation Service Curve Number (SCS-CN) approach continues to be ubiquitously used in GIS-BASED water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed within an integrated GIS modeling environment a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Spatial representation of hydrologic processes is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point source pollution. The methodology presented here uses the traditional SCS-CN method to predict runoff volume and spatial extent of saturated areas and uses a topographic index to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was incorporated in an existing GWLF water quality model and applied to sub-watersheds of the Delaware basin in the Catskill Mountains region of New York State. We found that the distributed CN-VSA approach provided a physically-based method that gives realistic results for watersheds with VSA hydrology.

Distribution measurement of radiation intensity with optical fiber at narrow space

Energy Technology Data Exchange (ETDEWEB)

Mori, Chizuo [Nagoya Univ. (Japan). School of Engineering

1998-07-01

Recently, in the field or radiation measurement, optical fiber and scintillation fiber are also begun to use. In order to investigate a new application method of the optical fiber to radiation measurement, a lithium compound for neutron converter and a ZnS(Ag) scintillator are kneaded with epoxy type adhesives, and much few weight of them is coated at an end of optical fiber with 1 to 2 mm in diameter, which is further overcoated with black paint or an aluminum cap for its shielding light to produce a thermal neutron detector. The thermal neutron detector is found to be measurable to neutron flux distribution very rapidly and in high position resolution by moving with computer automatically. This method can be measured selctively aimed radiation such as thermal neutron, rapid neutron, {gamma}-ray, and so forth by means of changing the neutron converter. And, the developed fiber method could be widely used for measurement of neutron and {gamma}-ray intensity distribution at fine interval in the nuclear radiation facilities such as neighbors of accelerator facilities, medical radiation facilities. (G.K.)

Coded aperture imaging of alpha source spatial distribution

International Nuclear Information System (INIS)

Talebitaher, Alireza; Shutler, Paul M.E.; Springham, Stuart V.; Rawat, Rajdeep S.; Lee, Paul

2012-01-01

The Coded Aperture Imaging (CAI) technique has been applied with CR-39 nuclear track detectors to image alpha particle source spatial distributions. The experimental setup comprised: a 226 Ra source of alpha particles, a laser-machined CAI mask, and CR-39 detectors, arranged inside a vacuum enclosure. Three different alpha particle source shapes were synthesized by using a linear translator to move the 226 Ra source within the vacuum enclosure. The coded mask pattern used is based on a Singer Cyclic Difference Set, with 400 pixels and 57 open square holes (representing ρ = 1/7 = 14.3% open fraction). After etching of the CR-39 detectors, the area, circularity, mean optical density and positions of all candidate tracks were measured by an automated scanning system. Appropriate criteria were used to select alpha particle tracks, and a decoding algorithm applied to the (x, y) data produced the de-coded image of the source. Signal to Noise Ratio (SNR) values obtained for alpha particle CAI images were found to be substantially better than those for corresponding pinhole images, although the CAI-SNR values were below the predictions of theoretical formulae. Monte Carlo simulations of CAI and pinhole imaging were performed in order to validate the theoretical SNR formulae and also our CAI decoding algorithm. There was found to be good agreement between the theoretical formulae and SNR values obtained from simulations. Possible reasons for the lower SNR obtained for the experimental CAI study are discussed.

On the radio source scintillations caused by plasma inhomogeneities behind a shock wave

International Nuclear Information System (INIS)

Pimenov, S.F.

1984-01-01

The turbulence in the interplanetary and interstellar medium is shown to become anisotropic and statistically inhomogeneous after a shock wave passing. Scintillation intensity spectra of radio sources are estimated. The possibilities to derive the inhomogeneity spectra and source brightness distribution from scintillation changes are discussed

Fiber optic distributed temperature sensing for fire source localization

Science.gov (United States)

Sun, Miao; Tang, Yuquan; Yang, Shuang; Sigrist, Markus W.; Li, Jun; Dong, Fengzhong

2017-08-01

A method for localizing a fire source based on a distributed temperature sensor system is proposed. Two sections of optical fibers were placed orthogonally to each other as the sensing elements. A tray of alcohol was lit to act as a fire outbreak in a cabinet with an uneven ceiling to simulate a real scene of fire. Experiments were carried out to demonstrate the feasibility of the method. Rather large fluctuations and systematic errors with respect to predicting the exact room coordinates of the fire source caused by the uneven ceiling were observed. Two mathematical methods (smoothing recorded temperature curves and finding temperature peak positions) to improve the prediction accuracy are presented, and the experimental results indicate that the fluctuation ranges and systematic errors are significantly reduced. The proposed scheme is simple and appears reliable enough to locate a fire source in large spaces.

Space-time structure of neutron and X-ray sources in a plasma focus

International Nuclear Information System (INIS)

Bostick, W.H.; Nardi, V.; Prior, W.

1977-01-01

Systematic measurements with paraffin collimators of the neutron emission intensity have been completed on a plasma focus with a 15-20 kV capacitor bank (hollow centre electrode; discharge period T approximately 8 μs; D 2 filling at 4-8 torr). The space resolution was 1 cm or better. These data indicate that at least 70% of the total neutron yield originates within hot-plasma regions where electron beams and high-energy D beams (approximately > 0.1-1 MeV) are produced. The neutron source is composed of several (approximately > 1-10) space-localized sources of different intensity, each with a duration approximately less than 5 ns (FWHM). Localized neutron sources and hard (approximately > 100 keV) X-ray sources have the same time multiplicity and are usually distributed in two groups over a time interval 40-400 ns long. By the mode of operation used by the authors one group of localized sources (Burst II) is observed 200-400 ns after the other group (Burst I) and its space distribution is broader than for Burst I. The maximum intensity of a localized source of neutrons in Burst I is much higher than the maximum intensity in Burst II. Secondary reactions T(D,n) 4 He (from the tritium produced only by primary reactions in the same discharge; no tritium was used in filling the discharge chamber) are observed in a time coincidence with the strongest D-D neutron pulse of Burst I. The neutron signal from a localized source with high intensity has a relatively long tail of small amplitude (area tail approximately less than 0.2 X area peak). This tail can be generated by the D-D reactions of the unconfined part of an ion beam in the cold plasma. Complete elimination of scattered neutrons on the detector was achieved in these measurements. (author)

Spatial distribution of saline water and possible sources of intrusion ...

African Journals Online (AJOL)

The spatial distribution of saline water and possible sources of intrusion into Lekki lagoon and transitional effects on the lacustrine ichthyofaunal characteristics were studied during March, 2006 and February, 2008. The water quality analysis indicated that, salinity has drastically increased recently in the lagoon (0.007 to ...

Detection prospects for high energy neutrino sources from the anisotropic matter distribution in the local universe

DEFF Research Database (Denmark)

Mertsch, Philipp; Rameez, Mohamed; Tamborra, Irene

2017-01-01

Constraints on the number and luminosity of the sources of the cosmic neutrinos detected by IceCube have been set by targeted searches for point sources. We set complementary constraints by using the 2MASS Redshift Survey (2MRS) catalogue, which maps the matter distribution of the local Universe....... Assuming that the distribution of the neutrino sources follows that of matter we look for correlations between `warm' spots on the IceCube skymap and the 2MRS matter distribution. Through Monte Carlo simulations of the expected number of neutrino multiplets and careful modelling of the detector performance...... (including that of IceCube-Gen2) we demonstrate that sources with local density exceeding $10^{-6} \\, \\text{Mpc}^{-3}$ and neutrino luminosity $L_{\

Gas and metal ion sources

International Nuclear Information System (INIS)

Oaks, E.; Yushkov, G.

1996-01-01

The positive ion sources are now of interest owing to both their conventional use, e.g., as injectors in charged-particle accelerators and the promising capabilities of intense ion beams in the processes related to the action of ions on various solid surfaces. For industrial use, the sources of intense ion beams and their power supplies should meet the specific requirements as follows: They should be simple, technologically effective, reliable, and relatively low-cost. Since the scanning of an intense ion beam is a complicated problem, broad ion beams hold the greatest promise. For the best use of such beams it is desirable that the ion current density be uniformly distributed over the beam cross section. The ion beam current density should be high enough for the treatment process be accomplished for an acceptable time. Thus, the ion sources used for high-current, high-dose metallurgical implantation should provide for gaining an exposure dose of ∼ 10 17 cm -2 in some tens of minutes. So the average ion current density at the surface under treatment should be over 10 -5 A/cm 2 . The upper limit of the current density depends on the admissible heating of the surface under treatment. The accelerating voltage of an ion source is dictated by its specific use; it seems to lie in the range from ∼1 kV (for the ion source used for surface sputtering) to ∼100 kV and over (for the ion sources used for high-current, high-dose metallurgical implantation)

An efficient central DOA tracking algorithm for multiple incoherently distributed sources

Science.gov (United States)

Hassen, Sonia Ben; Samet, Abdelaziz

2015-12-01

In this paper, we develop a new tracking method for the direction of arrival (DOA) parameters assuming multiple incoherently distributed (ID) sources. The new approach is based on a simple covariance fitting optimization technique exploiting the central and noncentral moments of the source angular power densities to estimate the central DOAs. The current estimates are treated as measurements provided to the Kalman filter that model the dynamic property of directional changes for the moving sources. Then, the covariance-fitting-based algorithm and the Kalman filtering theory are combined to formulate an adaptive tracking algorithm. Our algorithm is compared to the fast approximated power iteration-total least square-estimation of signal parameters via rotational invariance technique (FAPI-TLS-ESPRIT) algorithm using the TLS-ESPRIT method and the subspace updating via FAPI-algorithm. It will be shown that the proposed algorithm offers an excellent DOA tracking performance and outperforms the FAPI-TLS-ESPRIT method especially at low signal-to-noise ratio (SNR) values. Moreover, the performances of the two methods increase as the SNR values increase. This increase is more prominent with the FAPI-TLS-ESPRIT method. However, their performances degrade when the number of sources increases. It will be also proved that our method depends on the form of the angular distribution function when tracking the central DOAs. Finally, it will be shown that the more the sources are spaced, the more the proposed method can exactly track the DOAs.

Flows and Stratification of an Enclosure Containing Both Localised and Vertically Distributed Sources of Buoyancy

Science.gov (United States)

Partridge, Jamie; Linden, Paul

2013-11-01

We examine the flows and stratification established in a naturally ventilated enclosure containing both a localised and vertically distributed source of buoyancy. The enclosure is ventilated through upper and lower openings which connect the space to an external ambient. Small scale laboratory experiments were carried out with water as the working medium and buoyancy being driven directly by temperature differences. A point source plume gave localised heating while the distributed source was driven by a controllable heater mat located in the side wall of the enclosure. The transient temperatures, as well as steady state temperature profiles, were recorded and are reported here. The temperature profiles inside the enclosure were found to be dependent on the effective opening area A*, a combination of the upper and lower openings, and the ratio of buoyancy fluxes from the distributed and localised source Ψ =Bw/Bp . Industrial CASE award with ARUP.

Solution of multi-element LED light sources development automation problem

Science.gov (United States)

Chertov, Aleksandr N.; Gorbunova, Elena V.; Korotaev, Valery V.; Peretyagin, Vladimir S.

2014-09-01

The intensive development of LED technologies resulted in the creation of multicomponent light sources in the form of controlled illumination devices based on usage of mentioned LED technologies. These light sources are used in different areas of production (for example, in the food industry for sorting products or in the textile industry for quality control, etc.). The use of LED lighting products in the devices used in specialized lighting, became possible due to wide range of colors of light, LED structures (which determines the direction of radiation, the spatial distribution and intensity of the radiation, electrical, heat, power and other characteristics), and of course, the possibility of obtaining any shade in a wide dynamic range of brightness values. LED-based lighting devices are notable for the diversity of parameters and characteristics, such as color radiation, location and number of emitters, etc. Although LED technologies have several advantages, however, they require more attention if you need to ensure a certain character of illumination distribution and/or distribution of the color picture at a predetermined distance (for example, at flat surface, work zone, area of analysis or observation). This paper presents software designed for the development of the multicomponent LED light sources. The possibility of obtaining the desired color and energy distribution at the zone of analysis by specifying the spatial parameters of the created multicomponent light source and using of real power, spectral and color parameters and characteristics of the LEDs is shown as well.

The upgrade of intense pulsed neutron source (IPNS) through the change of coolant and reflector

CERN Document Server

Baek, I C; Iverson, E B

2002-01-01

The current intense pulsed neutron source (IPNS) depleted uranium target is cooled by light water. The inner reflector material is graphite and the outer reflector material is beryllium. The presence of H sub 2 O in the target moderates neutrons and leads to a higher absorption loss in the target than is necessary. D sub 2 O coolant in the small quantities required minimizes this effect. We have studied the possible improvement in IPNS beam fluxes that would result from changing the coolant from H sub 2 O to D sub 2 O and the inner reflector from graphite to beryllium. Neutron intensities were calculated for directions normal to the viewed surface of each moderator for four different cases of combinations of target coolant and reflector materials. The simulations reported here were performed using the MCNPX (version 2.1.5) computer program. Our results show that substantial gains in neutron beam intensities can be achieved by appropriate combination of target coolant and reflector materials. The combination o...

The role of Cobalt-60 source in Intensity Modulated Radiation Therapy: From modeling finite sources to treatment planning and conformal dose delivery

Science.gov (United States)

Dhanesar, Sandeep Kaur

are deliverable. Comparing the Co-60 dose distributions and DVHs to the IMRT plans from the clinic indicates that Co-60 is able to provide similar dose conformality to targets and dose sparing to critical organs. The results of the novel MLC segmentation algorithm and the photon fluence model proposed in this work compared well with the Monte Carlo calculations. In summary, the investigations presented in this thesis confirm that Co-60 tomotherapy is indeed capable of providing state-of-the-art conformal dose delivery. We have shown that the perceived beam limitations often identified with Co-60 (e.g., lower penetration, source size artifacts under small field collimation, and larger penumbra) are negligible when using intensity modulated techniques.

Panchromatic spectral energy distributions of Herschel sources

Science.gov (United States)

Berta, S.; Lutz, D.; Santini, P.; Wuyts, S.; Rosario, D.; Brisbin, D.; Cooray, A.; Franceschini, A.; Gruppioni, C.; Hatziminaoglou, E.; Hwang, H. S.; Le Floc'h, E.; Magnelli, B.; Nordon, R.; Oliver, S.; Page, M. J.; Popesso, P.; Pozzetti, L.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Roseboom, I.; Scott, D.; Symeonidis, M.; Valtchanov, I.; Viero, M.; Wang, L.

2013-03-01

Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S, and COSMOS fields, it is possible to sample the 8-500 μm spectral energy distributions (SEDs) of galaxies with at least 7-10 bands. Extending to the UV, optical, and near-infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selected restframe ten colors space, based on this rich data-set, using a superposition of multivariate Gaussian modes. We use this model to classify galaxies and build median SEDs of each class, which are then fitted with a modified version of the magphys code that combines stellar light, emission from dust heated by stars and a possible warm dust contribution heated by an active galactic nucleus (AGN). The color distribution of galaxies in each of the considered fields can be well described with the combination of 6-9 classes, spanning a large range of far- to near-infrared luminosity ratios, as well as different strength of the AGN contribution to bolometric luminosities. The defined Gaussian grouping is used to identify rare or odd sources. The zoology of outliers includes Herschel-detected ellipticals, very blue z ~ 1 Ly-break galaxies, quiescent spirals, and torus-dominated AGN with star formation. Out of these groups and outliers, a new template library is assembled, consisting of 32 SEDs describing the intrinsic scatter in the restframe UV-to-submm colors of infrared galaxies. This library is tested against L(IR) estimates with and without Herschel data included, and compared to eightother popular methods often adopted in the literature. When implementing Herschel photometry, these approaches produce L(IR) values consistent with each other within a median absolute deviation of 10-20%, the scatter being dominated more by fine tuning of the codes, rather than by the choice of

High repetition rate intense ion beam source

International Nuclear Information System (INIS)

Hammer, D.A.; Glidden, S.C.; Noonan, B.

1992-01-01

This final report describes a ≤ 150kV, 40kA, 100ns high repetition rate pulsed power system and intense ion beam source which is now in operation at Cornell University. Operation of the Magnetically-controlled Anode Plasma (MAP) ion diode at > 100Hz (burst mode for up to 10 pulse bursts) provides an initial look at repetition rate limitations of both the ion diode and beam diagnostics. The pulsed power systems are capable of ≥ 1kHz operation (up to 10 pulse bursts), but ion diode operation was limited to ∼100Hz because of diagnostic limitations. By varying MAP diode operating parameters, ion beams can be extracted at a few 10s of keV or at up to 150keV, the corresponding accelerating gap impedance ranging from about 1Ω to about 10Ω. The ability to make hundreds of test pulses per day at an average repetition rate of about 2 pulses per minute permits statistical analysis of diode operation as a function of various parameters. Most diode components have now survived more than 10 4 pulses, and the design and construction of the various pulsed power components of the MAP diode which have enabled us to reach this point are discussed. A high speed data acquisition system and companion analysis software capable of acquiring pulse data at 1ms intervals (in bursts of up to 10 pulses) and processing it in ≤ min is described

Floodplains as a source of fine sediment in grazed landscapes: Tracing the source of suspended sediment in the headwaters of an intensively managed agricultural landscape

Science.gov (United States)

Yu, Mingjing; Rhoads, Bruce L.

2018-05-01

The flux of fine sediment within agricultural watersheds is an important factor determining the environmental quality of streams and rivers. Despite this importance, the contributions of sediment sources to suspended sediment loads within intensively managed agricultural watersheds remain poorly understood. This study assesses the provenance of fine suspended sediment in the headwater portion of a river flowing through an agricultural landscape in Illinois. Sediment source samples were collected from five sources: croplands, forested floodplains, grasslands, upper grazed floodplains, and lower grazed floodplains. Event-based and aggregated suspended sediment samples were collected from the stream at the watershed outlet. Quantitative geochemical fingerprinting techniques and a mixing model were employed to estimate the relative contributions of sediment from the five sources to the suspended sediment loads. To account for possible effects of small sample sizes, the analysis was repeated with only two sources: grazed floodplains and croplands/grasslands/forested floodplains. Results based on mean values of tracers indicate that the vast majority of suspended sediment within the stream (>95%) is derived from erosion of channel banks and the soil surface within areas of grazed floodplains. Uncertainty analysis based on Monte Carlo simulations indicates that mean values of tracer properties, which do not account for sampling variability in these properties, probably overestimate contributions from the two major sources. Nevertheless, this analysis still supports the conclusion that floodplain erosion accounts for the largest percentage of instream sediment (≈55-75%). Although grazing occurs over only a small portion of the total watershed area, grazed floodplains, which lie in close proximity to the stream channel, are an important source of sediment in this headwater steam system. Efforts to reduce fluxes of fine sediment in this intensively managed landscape should

Spes: An intense source of Neutron-Rich Radioactive Beams at Legnaro

Science.gov (United States)

Andrighetto, A.; Manzolaro, M.; Corradetti, S.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Ballan, M.; Borgna, F.; D'Agostini, F.; Gramegna, F.; Prete, G.; Meneghetti, G.; Ferrari, M.; Zenoni, A.

2018-02-01

The Isotope Separation On-Line (ISOL) method for the production of Radioactive Ion Beams (RIB) is attracting significant interest in the worldwide nuclear physics community. Within this context the SPES (Selective Production of Exotic Species) RIB facility is now under construction at INFN LNL (Istituto Nazionale di Fisica Nucleare Laboratori Nazionali di Legnaro). This technique is established as one of the main techniques for high intensity and high quality beams production. The SPES facility will produce n-rich isotopes by means of a 40 MeV proton beam, emitted by a cyclotron, impinging on a uranium carbide multi-foil fission target. The aim of this work is to describe the most important results obtained by the study of the on-line behavior of the SPES production target assembly. This target system will produce RIBs at a rate of about 1013 fissions per second, it will be able to dissipate a total power of up to 10 kW, and it is planned to work continuously for 2 week-runs of irradiation. ISOL beams of 24 different elements will be produced, therefore a target and ion source development is ongoing to ensure a great variety of produced isotopes and to improve the beam intensity and purity.

Geometric effects in alpha particle detection from distributed air sources

International Nuclear Information System (INIS)

Gil, L.R.; Leitao, R.M.S.; Marques, A.; Rivera, A.

1994-08-01

Geometric effects associated to detection of alpha particles from distributed air sources, as it happens in Radon and Thoron measurements, are revisited. The volume outside which no alpha particle may reach the entrance window of the detector is defined and determined analytically for rectangular and cylindrical symmetry geometries. (author). 3 figs

Generation of intensity duration frequency curves and intensity temporal variability pattern of intense rainfall for Lages/SC

Directory of Open Access Journals (Sweden)

Célio Orli Cardoso

2014-04-01

Full Text Available The objective of this work was to analyze the frequency distribution and intensity temporal variability of intense rainfall for Lages/SC from diary pluviograph data. Data on annual series of maximum rainfalls from rain gauges of the CAV-UDESC Weather Station in Lages/SC were used from 2000 to 2009. Gumbel statistic distribution was applied in order to obtain the rainfall height and intensity in the following return periods: 2, 5, 10, 15 and 20 years. Results showed intensity-duration-frequency curves (I-D-F for those return periods, as well as I-D-F equations: i=2050.Tr0,20.(t+30-0,89, where i was the intensity, Tr was the rainfall return periods and t was the rainfall duration. For the intensity of temporal variability pattern along of the rainfall duration time, the convective, or advanced pattern was the predominant, with larger precipitate rainfalls in the first half of the duration. The same pattern presented larger occurrences in the spring and summer stations.

New initiatives on lepton flavor violation and neutrino oscillation with high intense muon and neutrino sources

CERN Document Server

Kuno, Yoshitaka; Pakvasa, Sandip

2002-01-01

The area of physics involving muons and neutrinos has become exciting in particle physics. Using their high intensity sources, physicists undertake, in various ways, extensive searches for new physics beyond the Standard Model, such as tests of supersymmetric grand unification (SUSY-GUT) and precision measurements of the muon and neutrino properties, which will in future extend to ambitious studies such as determination of the three-generation neutrino mixing matrix elements and CP violation in the lepton sector. The physics of this field is advancing, with potential improvements of the source

On Distributions of Emission Sources and Speed-of-Sound in Proton-Proton (Proton-Antiproton Collisions

Directory of Open Access Journals (Sweden)

Li-Na Gao

2015-01-01

Full Text Available The revised (three-source Landau hydrodynamic model is used in this paper to study the (pseudorapidity distributions of charged particles produced in proton-proton and proton-antiproton collisions at high energies. The central source is assumed to contribute with a Gaussian function which covers the rapidity distribution region as wide as possible. The target and projectile sources are assumed to emit isotropically particles in their respective rest frames. The model calculations obtained with a Monte Carlo method are fitted to the experimental data over an energy range from 0.2 to 13 TeV. The values of the squared speed-of-sound parameter in different collisions are then extracted from the width of the rapidity distributions.

Optimal planning of multiple distributed generation sources in distribution networks: A new approach

Energy Technology Data Exchange (ETDEWEB)

AlRashidi, M.R., E-mail: malrash2002@yahoo.com [Department of Electrical Engineering, College of Technological Studies, Public Authority for Applied Education and Training (PAAET) (Kuwait); AlHajri, M.F., E-mail: mfalhajri@yahoo.com [Department of Electrical Engineering, College of Technological Studies, Public Authority for Applied Education and Training (PAAET) (Kuwait)

2011-10-15

Highlights: {yields} A new hybrid PSO for optimal DGs placement and sizing. {yields} Statistical analysis to fine tune PSO parameters. {yields} Novel constraint handling mechanism to handle different constraints types. - Abstract: An improved particle swarm optimization algorithm (PSO) is presented for optimal planning of multiple distributed generation sources (DG). This problem can be divided into two sub-problems: the DG optimal size (continuous optimization) and location (discrete optimization) to minimize real power losses. The proposed approach addresses the two sub-problems simultaneously using an enhanced PSO algorithm capable of handling multiple DG planning in a single run. A design of experiment is used to fine tune the proposed approach via proper analysis of PSO parameters interaction. The proposed algorithm treats the problem constraints differently by adopting a radial power flow algorithm to satisfy the equality constraints, i.e. power flows in distribution networks, while the inequality constraints are handled by making use of some of the PSO features. The proposed algorithm was tested on the practical 69-bus power distribution system. Different test cases were considered to validate the proposed approach consistency in detecting optimal or near optimal solution. Results are compared with those of Sequential Quadratic Programming.

Optimal planning of multiple distributed generation sources in distribution networks: A new approach

International Nuclear Information System (INIS)

AlRashidi, M.R.; AlHajri, M.F.

2011-01-01

Highlights: → A new hybrid PSO for optimal DGs placement and sizing. → Statistical analysis to fine tune PSO parameters. → Novel constraint handling mechanism to handle different constraints types. - Abstract: An improved particle swarm optimization algorithm (PSO) is presented for optimal planning of multiple distributed generation sources (DG). This problem can be divided into two sub-problems: the DG optimal size (continuous optimization) and location (discrete optimization) to minimize real power losses. The proposed approach addresses the two sub-problems simultaneously using an enhanced PSO algorithm capable of handling multiple DG planning in a single run. A design of experiment is used to fine tune the proposed approach via proper analysis of PSO parameters interaction. The proposed algorithm treats the problem constraints differently by adopting a radial power flow algorithm to satisfy the equality constraints, i.e. power flows in distribution networks, while the inequality constraints are handled by making use of some of the PSO features. The proposed algorithm was tested on the practical 69-bus power distribution system. Different test cases were considered to validate the proposed approach consistency in detecting optimal or near optimal solution. Results are compared with those of Sequential Quadratic Programming.

Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac.

Science.gov (United States)

Wu, Q; Ma, H Y; Yang, Y; Sun, L T; Zhang, X Z; Zhang, Z M; Zhao, H Y; He, Y; Zhao, H W

2016-02-01

Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

Science.gov (United States)

Wu, Q.; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W.

2016-02-01

Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

Energy Technology Data Exchange (ETDEWEB)

Wu, Q., E-mail: wuq@impcas.ac.cn; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)

2016-02-15

Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

High frequency seismic signal generated by landslides on complex topographies: from point source to spatially distributed sources

Science.gov (United States)

Mangeney, A.; Kuehnert, J.; Capdeville, Y.; Durand, V.; Stutzmann, E.; Kone, E. H.; Sethi, S.

2017-12-01

During their flow along the topography, landslides generate seismic waves in a wide frequency range. These so called landquakes can be recorded at very large distances (a few hundreds of km for large landslides). The recorded signals depend on the landslide seismic source and the seismic wave propagation. If the wave propagation is well understood, the seismic signals can be inverted for the seismic source and thus can be used to get information on the landslide properties and dynamics. Analysis and modeling of long period seismic signals (10-150s) have helped in this way to discriminate between different landslide scenarios and to constrain rheological parameters (e.g. Favreau et al., 2010). This was possible as topography poorly affects wave propagation at these long periods and the landslide seismic source can be approximated as a point source. In the near-field and at higher frequencies (> 1 Hz) the spatial extent of the source has to be taken into account and the influence of the topography on the recorded seismic signal should be quantified in order to extract information on the landslide properties and dynamics. The characteristic signature of distributed sources and varying topographies is studied as a function of frequency and recording distance.The time dependent spatial distribution of the forces applied to the ground by the landslide are obtained using granular flow numerical modeling on 3D topography. The generated seismic waves are simulated using the spectral element method. The simulated seismic signal is compared to observed seismic data from rockfalls at the Dolomieu Crater of Piton de la Fournaise (La Réunion).Favreau, P., Mangeney, A., Lucas, A., Crosta, G., and Bouchut, F. (2010). Numerical modeling of landquakes. Geophysical Research Letters, 37(15):1-5.

The tracking performance of distributed recoverable flight control systems subject to high intensity radiated fields

Science.gov (United States)

Wang, Rui

It is known that high intensity radiated fields (HIRF) can produce upsets in digital electronics, and thereby degrade the performance of digital flight control systems. Such upsets, either from natural or man-made sources, can change data values on digital buses and memory and affect CPU instruction execution. HIRF environments are also known to trigger common-mode faults, affecting nearly-simultaneously multiple fault containment regions, and hence reducing the benefits of n-modular redundancy and other fault-tolerant computing techniques. Thus, it is important to develop models which describe the integration of the embedded digital system, where the control law is implemented, as well as the dynamics of the closed-loop system. In this dissertation, theoretical tools are presented to analyze the relationship between the design choices for a class of distributed recoverable computing platforms and the tracking performance degradation of a digital flight control system implemented on such a platform while operating in a HIRF environment. Specifically, a tractable hybrid performance model is developed for a digital flight control system implemented on a computing platform inspired largely by the NASA family of fault-tolerant, reconfigurable computer architectures known as SPIDER (scalable processor-independent design for enhanced reliability). The focus will be on the SPIDER implementation, which uses the computer communication system known as ROBUS-2 (reliable optical bus). A physical HIRF experiment was conducted at the NASA Langley Research Center in order to validate the theoretical tracking performance degradation predictions for a distributed Boeing 747 flight control system subject to a HIRF environment. An extrapolation of these results for scenarios that could not be physically tested is also presented.

MRI intensity inhomogeneity correction by combining intensity and spatial information

International Nuclear Information System (INIS)

Vovk, Uros; Pernus, Franjo; Likar, Bostjan

2004-01-01

We propose a novel fully automated method for retrospective correction of intensity inhomogeneity, which is an undesired phenomenon in many automatic image analysis tasks, especially if quantitative analysis is the final goal. Besides most commonly used intensity features, additional spatial image features are incorporated to improve inhomogeneity correction and to make it more dynamic, so that local intensity variations can be corrected more efficiently. The proposed method is a four-step iterative procedure in which a non-parametric inhomogeneity correction is conducted. First, the probability distribution of image intensities and corresponding second derivatives is obtained. Second, intensity correction forces, condensing the probability distribution along the intensity feature, are computed for each voxel. Third, the inhomogeneity correction field is estimated by regularization of all voxel forces, and fourth, the corresponding partial inhomogeneity correction is performed. The degree of inhomogeneity correction dynamics is determined by the size of regularization kernel. The method was qualitatively and quantitatively evaluated on simulated and real MR brain images. The obtained results show that the proposed method does not corrupt inhomogeneity-free images and successfully corrects intensity inhomogeneity artefacts even if these are more dynamic

Generalized Kapchinskij-Vladimirskij Distribution and Envelope Equation for High-intensity Beams in a Coupled Transverse Focusing Lattice

International Nuclear Information System (INIS)

Qin, Hong; Chung, Moses; Davidson, Ronald C.

2009-01-01

In an uncoupled lattice, the Kapchinskij-Vladimirskij (KV) distribution function first analyzed in 1959 is the only known exact solution of the nonlinear Vlasov-Maxwell equations for high- intensity beams including self-fields in a self-consistent manner. The KV solution is generalized here to high-intensity beams in a coupled transverse lattice using the recently developed generalized Courant-Snyder invariant for coupled transverse dynamics. This solution projects to a rotating, pulsating elliptical beam in transverse configuration space, determined by the generalized matrix envelope equation.

Family of Quantum Sources for Improving Near Field Accuracy in Transducer Modeling by the Distributed Point Source Method

Directory of Open Access Journals (Sweden)

Dominique Placko

2016-10-01

Full Text Available The distributed point source method, or DPSM, developed in the last decade has been used for solving various engineering problems—such as elastic and electromagnetic wave propagation, electrostatic, and fluid flow problems. Based on a semi-analytical formulation, the DPSM solution is generally built by superimposing the point source solutions or Green’s functions. However, the DPSM solution can be also obtained by superimposing elemental solutions of volume sources having some source density called the equivalent source density (ESD. In earlier works mostly point sources were used. In this paper the DPSM formulation is modified to introduce a new kind of ESD, replacing the classical single point source by a family of point sources that are referred to as quantum sources. The proposed formulation with these quantum sources do not change the dimension of the global matrix to be inverted to solve the problem when compared with the classical point source-based DPSM formulation. To assess the performance of this new formulation, the ultrasonic field generated by a circular planer transducer was compared with the classical DPSM formulation and analytical solution. The results show a significant improvement in the near field computation.

Transverse Beam Halo Measurements at High Intensity Neutrino Source (HINS) using Vibrating Wire Monitor

Energy Technology Data Exchange (ETDEWEB)

Chung, M.; Hanna, B.; Scarpine, V.; Shiltsev, V.; Steimel, J.; Artinian, S.; Arutunian, S.

2015-02-26

The measurement and control of beam halos will be critical for the applications of future high-intensity hadron linacs. In particular, beam profile monitors require a very high dynamic range when used for the transverse beam halo measurements. In this study, the Vibrating Wire Monitor (VWM) with aperture 60 mm was installed at the High Intensity Neutrino Source (HINS) front-end to measure the transverse beam halo. A vibrating wire is excited at its resonance frequency with the help of a magnetic feedback loop, and the vibrating and sensitive wires are connected through a balanced arm. The sensitive wire is moved into the beam halo region by a stepper motor controlled translational stage. We study the feasibility of the vibrating wire for the transverse beam halo measurements in the low-energy front-end of the proton linac.

Energy and intensity distributions of 0.279 MeV multiply Compton-scattered photons in soldering material

International Nuclear Information System (INIS)

Singh, Manpreet; Singh, Gurvinderjit; Singh, Bhajan; Sandhu, B.S.

2007-01-01

An inverse response matrix converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a photon spectrum. This also results in extraction of intensity distribution of multiply scattered events originating from interactions of 0.279 MeV photons with thick targets of soldering material. The observed pulse-height distributions are a composite of singly and multiply scattered events in addition to bremmstrahlung-and Rayleigh-scattered events. To evaluate the contribution of multiply scattered events, the spectrum of singly scattered events contributing to inelastic Compton peak is reconstructed analytically. The optimum thickness (saturation depth), at which the number of multiply scattered events saturates, has been measured. Monte Carlo calculations also support the present results

Intense beams from gases generated by a permanent magnet ECR ion source at PKU

Energy Technology Data Exchange (ETDEWEB)

Ren, H. T.; Chen, J. E. [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); Peng, S. X.; Lu, P. N.; Yan, S.; Zhou, Q. F.; Zhao, J.; Yuan, Z. X.; Guo, Z. Y. [SKLNPT, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

2012-02-15

An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O{sup +}, H{sup +}, and D{sup +} to N{sup +}, Ar{sup +}, and He{sup +}. Up to now, about 120 mA of H{sup +}, 83 mA of D{sup +}, 50 mA of O{sup +}, 63 mA of N{sup +}, 70 mA of Ar{sup +}, and 65 mA of He{sup +} extracted at 50 kV through a {phi} 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 {pi} mm mrad. Tungsten samples were irradiated by H{sup +} or He{sup +} beam extracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He{sup +} beam injector for coupled radio frequency quadruple and SFRFQ cavity, He{sup +} beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He{sup +} beam.

The Galactic Distribution of Massive Star Formation from the Red MSX Source Survey

Science.gov (United States)

Figura, Charles C.; Urquhart, J. S.

2013-01-01

Massive stars inject enormous amounts of energy into their environments in the form of UV radiation and molecular outflows, creating HII regions and enriching local chemistry. These effects provide feedback mechanisms that aid in regulating star formation in the region, and may trigger the formation of subsequent generations of stars. Understanding the mechanics of massive star formation presents an important key to understanding this process and its role in shaping the dynamics of galactic structure. The Red MSX Source (RMS) survey is a multi-wavelength investigation of ~1200 massive young stellar objects (MYSO) and ultra-compact HII (UCHII) regions identified from a sample of colour-selected sources from the Midcourse Space Experiment (MSX) point source catalog and Two Micron All Sky Survey. We present a study of over 900 MYSO and UCHII regions investigated by the RMS survey. We review the methods used to determine distances, and investigate the radial galactocentric distribution of these sources in context with the observed structure of the galaxy. The distribution of MYSO and UCHII regions is found to be spatially correlated with the spiral arms and galactic bar. We examine the radial distribution of MYSOs and UCHII regions and find variations in the star formation rate between the inner and outer Galaxy and discuss the implications for star formation throughout the galactic disc.

Radiographic Control of 137-Cs Brachytherapy Sources

International Nuclear Information System (INIS)

Bistrovic, M.; Viculin, T.; Jurkovic, S.

2003-01-01

1 37C s brachytherapy sources are practical for the intracavitary application due to their relatively long lifetime (T 1/2 = 30 y). On the other hand, due to the relatively low energy (0.66 MeV) of the emitted photons, they are suitable for an efficient radiation protection. The dose distribution around the sources is usually calculated by a specific program. However this program requires the knowledge of the position of sources within the applicator as well as the distribution of activity along them. The only way to learn these data is to make an X-ray picture of applicators and sources superimposed to the autoradiography of every source. It is difficult to achieve satisfactory radiographs with high dose rate sources with standard X-ray film material because autoradiography covers the structure of the radiographic shadow. The problem can be overcome either by applying a high intensity X-ray or gamma beam (originating from a radiotherapeutic machine), or by using photographic material of very low sensitivity, for example photographic paper. Combining both possibilities one can obtain satisfactory images. (author)

Basic design of shield blocks for a spallation neutron source under the high-intensity proton accelerator project

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Katsuhiko; Maekawa, Fujio; Takada, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2003-03-01

Under the JAERI-KEK High-Intensity Proton Accelerator Project (J-PARC), a spallation neutron source driven by a 3 GeV-1 MW proton beam is planed to be constructed as a main part of the Materials and Life Science Facility. Overall dimensions of a biological shield of the neutron source had been determined by evaluation of shielding performance by Monte Carlo calculations. This report describes results of design studies on an optimum dividing scheme in terms of cost and treatment and mechanical strength of shield blocks for the biological shield. As for mechanical strength, it was studied whether the shield blocks would be stable, fall down or move to a horizontal direction in case of an earthquake of seismic intensity of 5.5 (250 Gal) as an abnormal load. For ceiling shielding blocks being supported by both ends of the long blocks, maximum bending moment and an amount of maximum deflection of their center were evaluated. (author)

Basic design of shield blocks for a spallation neutron source under the high-intensity proton accelerator project

CERN Document Server

Yoshida, K; Takada, H

2003-01-01

Under the JAERI-KEK High-Intensity Proton Accelerator Project (J-PARC), a spallation neutron source driven by a 3 GeV-1 MW proton beam is planed to be constructed as a main part of the Materials and Life Science Facility. Overall dimensions of a biological shield of the neutron source had been determined by evaluation of shielding performance by Monte Carlo calculations. This report describes results of design studies on an optimum dividing scheme in terms of cost and treatment and mechanical strength of shield blocks for the biological shield. As for mechanical strength, it was studied whether the shield blocks would be stable, fall down or move to a horizontal direction in case of an earthquake of seismic intensity of 5.5 (250 Gal) as an abnormal load. For ceiling shielding blocks being supported by both ends of the long blocks, maximum bending moment and an amount of maximum deflection of their center were evaluated.

Establishment of a Practical Approach for Characterizing the Source of Particulates in Water Distribution Systems

Directory of Open Access Journals (Sweden)

Seon-Ha Chae

2016-02-01

Full Text Available Water quality complaints related to particulate matter and discolored water can be troublesome for water utilities in terms of follow-up investigations and implementation of appropriate actions because particulate matter can enter from a variety of sources; moreover, physicochemical processes can affect the water quality during the purification and transportation processes. The origin of particulates can be attributed to sources such as background organic/inorganic materials from water sources, water treatment plants, water distribution pipelines that have deteriorated, and rehabilitation activities in the water distribution systems. In this study, a practical method is proposed for tracing particulate sources. The method entails collecting information related to hydraulic, water quality, and structural conditions, employing a network flow-path model, and establishing a database of physicochemical properties for tubercles and slimes. The proposed method was implemented within two city water distribution systems that were located in Korea. These applications were conducted to demonstrate the practical applicability of the method for providing solutions to customer complaints. The results of the field studies indicated that the proposed method would be feasible for investigating the sources of particulates and for preparing appropriate action plans for complaints related to particulate matter.

Livermore intense neutron source: design concepts

International Nuclear Information System (INIS)

Davis, J.C.; Anderson, J.D.; Booth, R.; Logan, C.M.; Osher, J.E.

1975-07-01

The Lawrence Livermore laboratory proposes to build an irradiation facility containing several 14 MeV T(d,n) neutron sources for materials damage experimentation. A source strength of 4 x 10 13 n/s can be produced with 400 keV D + beam on the tritium in titanium target system now used on the Livermore Rotating Target Neutron Source (RTNS). To produce the desired source strength an accelerator which can deliver 150 mA of 400 keV D + ions must be built. For the target to remain within the time-temperature regime of the present system it must have a diameter of 46 cm and rotate at 5000 rpm. With a beam spot 1 cm fwhm the useful target lifetime is expected to be the 100 hours typical of the present system. A maximum flux of 1.5 x 10 13 n/cm 2 s will be attainable over a sample 1 mm thick by 8 mm in diameter. (U.S.)

Identification of Sparse Audio Tampering Using Distributed Source Coding and Compressive Sensing Techniques

Directory of Open Access Journals (Sweden)

Valenzise G

2009-01-01

Full Text Available In the past few years, a large amount of techniques have been proposed to identify whether a multimedia content has been illegally tampered or not. Nevertheless, very few efforts have been devoted to identifying which kind of attack has been carried out, especially due to the large data required for this task. We propose a novel hashing scheme which exploits the paradigms of compressive sensing and distributed source coding to generate a compact hash signature, and we apply it to the case of audio content protection. The audio content provider produces a small hash signature by computing a limited number of random projections of a perceptual, time-frequency representation of the original audio stream; the audio hash is given by the syndrome bits of an LDPC code applied to the projections. At the content user side, the hash is decoded using distributed source coding tools. If the tampering is sparsifiable or compressible in some orthonormal basis or redundant dictionary, it is possible to identify the time-frequency position of the attack, with a hash size as small as 200 bits/second; the bit saving obtained by introducing distributed source coding ranges between 20% to 70%.

Open source electronic health record and patient data management system for intensive care.

Science.gov (United States)

Massaut, Jacques; Reper, Pascal

2008-01-01

In Intensive Care Units, the amount of data to be processed for patients care, the turn over of the patients, the necessity for reliability and for review processes indicate the use of Patient Data Management Systems (PDMS) and electronic health records (EHR). To respond to the needs of an Intensive Care Unit and not to be locked with proprietary software, we developed a PDMS and EHR based on open source software and components. The software was designed as a client-server architecture running on the Linux operating system and powered by the PostgreSQL data base system. The client software was developed in C using GTK interface library. The application offers to the users the following functions: medical notes captures, observations and treatments, nursing charts with administration of medications, scoring systems for classification, and possibilities to encode medical activities for billing processes. Since his deployment in February 2004, the PDMS was used to care more than three thousands patients with the expected software reliability and facilitated data management and review processes. Communications with other medical software were not developed from the start, and are realized by the use of the Mirth HL7 communication engine. Further upgrade of the system will include multi-platform support, use of typed language with static analysis, and configurable interface. The developed system based on open source software components was able to respond to the medical needs of the local ICU environment. The use of OSS for development allowed us to customize the software to the preexisting organization and contributed to the acceptability of the whole system.

Neutron-irradiation facilities at the Intense Pulsed Neutron Source-I for fusion magnet materials studies

International Nuclear Information System (INIS)

Brown, B.S.; Blewitt, T.H.

1982-01-01

The decommissioning of reactor-based neutron sources in the USA has led to the development of a new generation of neutron sources that employ high-energy accelerators. Among the accelerator-based neutron sources presently in operation, the highest-flux source is the Intense Pulsed Neutron Source (IPNS), a user facility at Argonne National Laboratory. Neutrons in this source are produced by the interaction of 400 to 500 MeV protons with either of two 238 U target systems. In the Radiation Effects Facility (REF), the 238 U target is surrounded by Pb for neutron generatjion and reflection. The REF has three separate irradiation thimbles. Two thimbles provide irradiation temperatures between that of liquid He and several hundred degrees centigrade. The third thimble operates at ambient temperature. The large irradiation volume, the neutron spectrum and flux, the ability to transfer samples without warm up, and the dedication of the facilities during the irradiation make this ideally suited for radiation damage studies on components for superconducting fusion magnets. Possible experiments for fusion magnet materials are discussed on cyclic irradiation and annealing of stabilizers in a high magnetic field, mechanical tests on organic insulation irradiated at 4 K, and superconductors measured in high fields after irradiation

Z-Source-Inverter-Based Flexible Distributed Generation System Solution for Grid Power Quality Improvement

DEFF Research Database (Denmark)

Blaabjerg, Frede; Vilathgamuwa, D. M.; Loh, Poh Chiang

2009-01-01

Distributed generation (DG) systems are usually connected to the grid using power electronic converters. Power delivered from such DG sources depends on factors like energy availability and load demand. The converters used in power conversion do not operate with their full capacity all the time......-stage buck-boost inverter, recently proposed Z-source inverter (ZSI) is a good candidate for future DG systems. This paper presents a controller design for a ZSI-based DG system to improve power quality of distribution systems. The proposed control method is tested with simulation results obtained using...

EPOS-An intense positron beam project at the ELBE radiation source in Rossendorf

International Nuclear Information System (INIS)

Krause-Rehberg, R.; Sachert, S.; Brauer, G.; Rogov, A.; Noack, K.

2006-01-01

EPOS, the acronym of ELBE Positron Source, describes a running project to build an intense pulsed beam of mono-energetic positrons (0.2-40 keV) for materials research. Positrons will be created via pair production at a tungsten target using the pulsed 40 MeV electron beam of the superconducting linac electron linac with high brilliance and low emittance (ELBE) at Forschungszentrum Rossendorf (near Dresden, Germany). The chosen design of the system under construction is described and results of calculations simulating the interaction of the electron beam with the target are presented, and positron beam formation and transportation is also discussed

10 CFR 32.74 - Manufacture and distribution of sources or devices containing byproduct material for medical use.

Science.gov (United States)

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Manufacture and distribution of sources or devices... SPECIFIC DOMESTIC LICENSES TO MANUFACTURE OR TRANSFER CERTAIN ITEMS CONTAINING BYPRODUCT MATERIAL Generally Licensed Items § 32.74 Manufacture and distribution of sources or devices containing byproduct material for...

Investigating The Neutron Flux Distribution Of The Miniature Neutron Source Reactor MNSR Type

International Nuclear Information System (INIS)

Nguyen Hoang Hai; Do Quang Binh

2011-01-01

Neutron flux distribution is the important characteristic of nuclear reactor. In this article, four energy group neutron flux distributions of the miniature neutron source reactor MNSR type versus radial and axial directions are investigated in case the control rod is fully withdrawn. In addition, the effect of control rod positions on the thermal neutron flux distribution is also studied. The group constants for all reactor components are generated by the WIMSD code, and the neutron flux distributions are calculated by the CITATION code. The results show that the control rod positions only affect in the planning area for distribution in the region around the control rod. (author)

Improved heating efficiency with High-Intensity Focused Ultrasound using a new ultrasound source excitation.

Science.gov (United States)

Bigelow, Timothy A

2009-01-01

High-Intensity Focused Ultrasound (HIFU) is quickly becoming one of the best methods to thermally ablate tissue noninvasively. Unlike RF or Laser ablation, the tissue can be destroyed without inserting any probes into the body minimizing the risk of secondary complications such as infections. In this study, the heating efficiency of HIFU sources is improved by altering the excitation of the ultrasound source to take advantage of nonlinear propagation. For ultrasound, the phase velocity of the ultrasound wave depends on the amplitude of the wave resulting in the generation of higher harmonics. These higher harmonics are more efficiently converted into heat in the body due to the frequency dependence of the ultrasound absorption in tissue. In our study, the generation of the higher harmonics by nonlinear propagation is enhanced by transmitting an ultrasound wave with both the fundamental and a higher harmonic component included. Computer simulations demonstrated up to a 300% increase in temperature increase compared to transmitting at only the fundamental for the same acoustic power transmitted by the source.

A practical algorithm for distribution state estimation including renewable energy sources

Energy Technology Data Exchange (ETDEWEB)

Niknam, Taher [Electronic and Electrical Department, Shiraz University of Technology, Modares Blvd., P.O. 71555-313, Shiraz (Iran); Firouzi, Bahman Bahmani [Islamic Azad University Marvdasht Branch, Marvdasht (Iran)

2009-11-15

Renewable energy is energy that is in continuous supply over time. These kinds of energy sources are divided into five principal renewable sources of energy: the sun, the wind, flowing water, biomass and heat from within the earth. According to some studies carried out by the research institutes, about 25% of the new generation will be generated by Renewable Energy Sources (RESs) in the near future. Therefore, it is necessary to study the impact of RESs on the power systems, especially on the distribution networks. This paper presents a practical Distribution State Estimation (DSE) including RESs and some practical consideration. The proposed algorithm is based on the combination of Nelder-Mead simplex search and Particle Swarm Optimization (PSO) algorithms, called PSO-NM. The proposed algorithm can estimate load and RES output values by Weighted Least-Square (WLS) approach. Some practical considerations are var compensators, Voltage Regulators (VRs), Under Load Tap Changer (ULTC) transformer modeling, which usually have nonlinear and discrete characteristics, and unbalanced three-phase power flow equations. The comparison results with other evolutionary optimization algorithms such as original PSO, Honey Bee Mating Optimization (HBMO), Neural Networks (NNs), Ant Colony Optimization (ACO), and Genetic Algorithm (GA) for a test system demonstrate that PSO-NM is extremely effective and efficient for the DSE problems. (author)

Relationship Study on Land Use Spatial Distribution Structure and Energy-Related Carbon Emission Intensity in Different Land Use Types of Guangdong, China, 1996–2008

Directory of Open Access Journals (Sweden)

Yi Huang

2013-01-01

Full Text Available This study attempts to discuss the relationship between land use spatial distribution structure and energy-related carbon emission intensity in Guangdong during 1996–2008. We quantized the spatial distribution structure of five land use types including agricultural land, industrial land, residential and commercial land, traffic land, and other land through applying spatial Lorenz curve and Gini coefficient. Then the corresponding energy-related carbon emissions in each type of land were calculated in the study period. Through building the reasonable regression models, we found that the concentration degree of industrial land is negatively correlated with carbon emission intensity in the long term, whereas the concentration degree is positively correlated with carbon emission intensity in agricultural land, residential and commercial land, traffic land, and other land. The results also indicate that land use spatial distribution structure affects carbon emission intensity more intensively than energy efficiency and production efficiency do. These conclusions provide valuable reference to develop comprehensive policies for energy conservation and carbon emission reduction in a new perspective.

Measurements of neutron intensity from liquid deuterium moderator of the cold neutron source of KUR

International Nuclear Information System (INIS)

Kawai, Takeshi; Ebisawa, Toru; Akiyoshi, Tsunekazu; Tasaki, Seiji

1990-01-01

The neutron spectra from the liquid deuterium moderator of the cold neutron source of KUR were measured by the time of flight (TOF) method similar to the previous measurements for the liquid hydrogen moderator. The cold neutron gain factor is found to be about 20 ∼ 28 times for the wavelength longer than 6 A. Cold neutron intensities from the liquid deuterium moderator and from the liquid hydrogen moderator are compared and discussed. (author)

Distribution of hadron intranuclear cascade for large distance from a source

International Nuclear Information System (INIS)

Bibin, V.L.; Kazarnovskij, M.V.; Serezhnikov, S.V.

1985-01-01

Analytical solution of the problem of three-component hadron cascade development for large distances from a source is obtained in the framework of a series of simplifying assumptions. It makes possible to understand physical mechanisms of the process studied and to obtain approximate asymptotic expressions for hadron distribution functions

Absolute intensities of supersonic beams

International Nuclear Information System (INIS)

Beijerinck, H.C.W.; Habets, A.H.M.; Verster, N.F.

1977-01-01

In a molecular beam experiment the center-line intensity I(0) (particles s -1 sterad -1 ) and the flow rate dN/dt (particles s -1 ) of a beam source are important features. To compare the performance of different types of beam sources the peaking factor, kappa, is defined as the ratio kappa=π(I(0)/dN/dt). The factor π is added to normalize to kappa=1 for an effusive source. The ideal peaking factor for the supersonic flow from a nozzle follows from continuum theory. Numerical values of kappa are available. Experimental values of kappa for an argon expansion are presented in this paper, confirming these calculations. The actual center-line intensity of a supersonic beam source with a skimmer is reduced in comparison to this ideal intensity if the skimmer shields part of the virtual source from the detector. Experimental data on the virtual source radius are given enabling one to predict this shielding quantitatively. (Auth.)

Strategies for satellite-based monitoring of CO2 from distributed area and point sources

Science.gov (United States)

Schwandner, Florian M.; Miller, Charles E.; Duren, Riley M.; Natraj, Vijay; Eldering, Annmarie; Gunson, Michael R.; Crisp, David

2014-05-01

Atmospheric CO2 budgets are controlled by the strengths, as well as the spatial and temporal variabilities of CO2 sources and sinks. Natural CO2 sources and sinks are dominated by the vast areas of the oceans and the terrestrial biosphere. In contrast, anthropogenic and geogenic CO2 sources are dominated by distributed area and point sources, which may constitute as much as 70% of anthropogenic (e.g., Duren & Miller, 2012), and over 80% of geogenic emissions (Burton et al., 2013). Comprehensive assessments of CO2 budgets necessitate robust and highly accurate satellite remote sensing strategies that address the competing and often conflicting requirements for sampling over disparate space and time scales. Spatial variability: The spatial distribution of anthropogenic sources is dominated by patterns of production, storage, transport and use. In contrast, geogenic variability is almost entirely controlled by endogenic geological processes, except where surface gas permeability is modulated by soil moisture. Satellite remote sensing solutions will thus have to vary greatly in spatial coverage and resolution to address distributed area sources and point sources alike. Temporal variability: While biogenic sources are dominated by diurnal and seasonal patterns, anthropogenic sources fluctuate over a greater variety of time scales from diurnal, weekly and seasonal cycles, driven by both economic and climatic factors. Geogenic sources typically vary in time scales of days to months (geogenic sources sensu stricto are not fossil fuels but volcanoes, hydrothermal and metamorphic sources). Current ground-based monitoring networks for anthropogenic and geogenic sources record data on minute- to weekly temporal scales. Satellite remote sensing solutions would have to capture temporal variability through revisit frequency or point-and-stare strategies. Space-based remote sensing offers the potential of global coverage by a single sensor. However, no single combination of orbit

No Additional Benefits of Block- Over Evenly-Distributed High-Intensity Interval Training within a Polarized Microcycle.

Science.gov (United States)

McGawley, Kerry; Juudas, Elisabeth; Kazior, Zuzanna; Ström, Kristoffer; Blomstrand, Eva; Hansson, Ola; Holmberg, Hans-Christer

2017-01-01

Introduction: The current study aimed to investigate the responses to block- versus evenly-distributed high-intensity interval training (HIT) within a polarized microcycle. Methods: Twenty well-trained junior cross-country skiers (10 males, age 17.6 ± 1.5 and 10 females, age 17.3 ± 1.5) completed two, 3-week periods of training (EVEN and BLOCK) in a randomized, crossover-design study. In EVEN, 3 HIT sessions (5 × 4-min of diagonal-stride roller-skiing) were completed at a maximal sustainable intensity each week while low-intensity training (LIT) was distributed evenly around the HIT. In BLOCK, the same 9 HIT sessions were completed in the second week while only LIT was completed in the first and third weeks. Heart rate (HR), session ratings of perceived exertion (sRPE), and perceived recovery (pREC) were recorded for all HIT and LIT sessions, while distance covered was recorded for each HIT interval. The recovery-stress questionnaire for athletes (RESTQ-Sport) was completed weekly. Before and after EVEN and BLOCK, resting saliva and muscle samples were collected and an incremental test and 600-m time-trial (TT) were completed. Results: Pre- to post-testing revealed no significant differences between EVEN and BLOCK for changes in resting salivary cortisol, testosterone, or IgA, or for changes in muscle capillary density, fiber area, fiber composition, enzyme activity (CS, HAD, and PFK) or the protein content of VEGF or PGC-1α. Neither were any differences observed in the changes in skiing economy, [Formula: see text] or 600-m time-trial performance between interventions. These findings were coupled with no significant differences between EVEN and BLOCK for distance covered during HIT, summated HR zone scores, total sRPE training load, overall pREC or overall recovery-stress state. However, 600-m TT performance improved from pre- to post-training, irrespective of intervention ( P = 0.003), and a number of hormonal and muscle biopsy markers were also significantly

Inverse radiation problem of temperature distribution in one-dimensional isotropically scattering participating slab with variable refractive index

International Nuclear Information System (INIS)

Namjoo, A.; Sarvari, S.M. Hosseini; Behzadmehr, A.; Mansouri, S.H.

2009-01-01

In this paper, an inverse analysis is performed for estimation of source term distribution from the measured exit radiation intensities at the boundary surfaces in a one-dimensional absorbing, emitting and isotropically scattering medium between two parallel plates with variable refractive index. The variation of refractive index is assumed to be linear. The radiative transfer equation is solved by the constant quadrature discrete ordinate method. The inverse problem is formulated as an optimization problem for minimizing an objective function which is expressed as the sum of square deviations between measured and estimated exit radiation intensities at boundary surfaces. The conjugate gradient method is used to solve the inverse problem through an iterative procedure. The effects of various variables on source estimation are investigated such as type of source function, errors in the measured data and system parameters, gradient of refractive index across the medium, optical thickness, single scattering albedo and boundary emissivities. The results show that in the case of noisy input data, variation of system parameters may affect the inverse solution, especially at high error values in the measured data. The error in measured data plays more important role than the error in radiative system parameters except the refractive index distribution; however the accuracy of source estimation is very sensitive toward error in refractive index distribution. Therefore, refractive index distribution and measured exit intensities should be measured accurately with a limited error bound, in order to have an accurate estimation of source term in a graded index medium.

Important questions asked by family members of intensive care unit patients.

Science.gov (United States)

Peigne, Vincent; Chaize, Marine; Falissard, Bruno; Kentish-Barnes, Nancy; Rusinova, Katerina; Megarbane, Bruno; Bele, Nicolas; Cariou, Alain; Fieux, Fabienne; Garrouste-Orgeas, Maite; Georges, Hugues; Jourdain, Merce; Kouatchet, Achille; Lautrette, Alexandre; Legriel, Stephane; Regnier, Bernard; Renault, Anne; Thirion, Marina; Timsit, Jean-Francois; Toledano, Dany; Chevret, Sylvie; Pochard, Frédéric; Schlemmer, Benoît; Azoulay, Elie

2011-06-01

Relatives often lack important information about intensive care unit patients. High-quality information is crucial to help relatives overcome the often considerable situational stress and to acquire the ability to participate in the decision-making process, most notably regarding the appropriate level of care. We aimed to develop a list of questions important for relatives of patients in the intensive care unit. This was a multicenter study. Questions asked by relatives of intensive care unit patients were collected from five different sources (literature, panel of 28 intensive care unit nurses and physicians, 1-wk survey of nurses and 1-wk survey of physicians in 14 intensive care units, and in-depth interviews with 14 families). After a qualitative analysis (framework approach and thematic analysis), questions were rated by 22 relatives and 14 intensive care unit physicians, and the ratings were analyzed using principal component analysis and hierarchical clustering. The five sources produced 2,135 questions. Removal of duplicates and redundancies left 443 questions, which were distributed among nine predefined domains using a framework approach ("diagnosis," "treatment," "prognosis," "comfort," "interaction," "communication," "family," "end of life," and "postintensive care unit management"). Thematic analysis in each domain led to the identification of 46 themes, which were reworded as 46 different questions. Ratings by relatives and physicians showed that 21 of these questions were particularly important for relatives of intensive care unit patients. This study increases knowledge about the informational needs of relatives of intensive care unit patients. This list of questions may prove valuable for both relatives and intensive care unit physicians as a tool for improving communication in the intensive care unit.

Sociospatial distribution of access to facilities for moderate and vigorous intensity physical activity in Scotland by different modes of transport

Directory of Open Access Journals (Sweden)

Lamb Karen E

2012-07-01

Full Text Available Abstract Background People living in neighbourhoods of lower socioeconomic status have been shown to have higher rates of obesity and a lower likelihood of meeting physical activity recommendations than their more affluent counterparts. This study examines the sociospatial distribution of access to facilities for moderate or vigorous intensity physical activity in Scotland and whether such access differs by the mode of transport available and by Urban Rural Classification. Methods A database of all fixed physical activity facilities was obtained from the national agency for sport in Scotland. Facilities were categorised into light, moderate and vigorous intensity activity groupings before being mapped. Transport networks were created to assess the number of each type of facility accessible from the population weighted centroid of each small area in Scotland on foot, by bicycle, by car and by bus. Multilevel modelling was used to investigate the distribution of the number of accessible facilities by small area deprivation within urban, small town and rural areas separately, adjusting for population size and local authority. Results Prior to adjustment for Urban Rural Classification and local authority, the median number of accessible facilities for moderate or vigorous intensity activity increased with increasing deprivation from the most affluent or second most affluent quintile to the most deprived for all modes of transport. However, after adjustment, the modelling results suggest that those in more affluent areas have significantly higher access to moderate and vigorous intensity facilities by car than those living in more deprived areas. Conclusions The sociospatial distributions of access to facilities for both moderate intensity and vigorous intensity physical activity were similar. However, the results suggest that those living in the most affluent neighbourhoods have poorer access to facilities of either type that can be reached on foot

Coupling biophysical processes and water rights to simulate spatially distributed water use in an intensively managed hydrologic system

Science.gov (United States)

Han, Bangshuai; Benner, Shawn G.; Bolte, John P.; Vache, Kellie B.; Flores, Alejandro N.

2017-07-01

Humans have significantly altered the redistribution of water in intensively managed hydrologic systems, shifting the spatiotemporal patterns of surface water. Evaluating water availability requires integration of hydrologic processes and associated human influences. In this study, we summarize the development and evaluation of an extensible hydrologic model that explicitly integrates water rights to spatially distribute irrigation waters in a semi-arid agricultural region in the western US, using the Envision integrated modeling platform. The model captures both human and biophysical systems, particularly the diversion of water from the Boise River, which is the main water source that supports irrigated agriculture in this region. In agricultural areas, water demand is estimated as a function of crop type and local environmental conditions. Surface water to meet crop demand is diverted from the stream reaches, constrained by the amount of water available in the stream, the water-rights-appropriated amount, and the priority dates associated with particular places of use. Results, measured by flow rates at gaged stream and canal locations within the study area, suggest that the impacts of irrigation activities on the magnitude and timing of flows through this intensively managed system are well captured. The multi-year averaged diverted water from the Boise River matches observations well, reflecting the appropriation of water according to the water rights database. Because of the spatially explicit implementation of surface water diversion, the model can help diagnose places and times where water resources are likely insufficient to meet agricultural water demands, and inform future water management decisions.

Using a topographic index to distribute variable source area runoff predicted with the SCS curve-number equation

Science.gov (United States)

Lyon, Steve W.; Walter, M. Todd; Gérard-Marchant, Pierre; Steenhuis, Tammo S.

2004-10-01

Because the traditional Soil Conservation Service curve-number (SCS-CN) approach continues to be used ubiquitously in water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed and tested a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Predicting the location of source areas is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point-source pollution. The method presented here used the traditional SCS-CN approach to predict runoff volume and spatial extent of saturated areas and a topographic index, like that used in TOPMODEL, to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was applied to two subwatersheds of the Delaware basin in the Catskill Mountains region of New York State and one watershed in south-eastern Australia to produce runoff-probability maps. Observed saturated area locations in the watersheds agreed with the distributed CN-VSA method. Results showed good agreement with those obtained from the previously validated soil moisture routing (SMR) model. When compared with the traditional SCS-CN method, the distributed CN-VSA method predicted a similar total volume of runoff, but vastly different locations of runoff generation. Thus, the distributed CN-VSA approach provides a physically based method that is simple enough to be incorporated into water quality models, and other tools that currently use the traditional SCS-CN method, while still adhering to the principles of VSA hydrology.

Principal parameters of classical multiply charged ion sources

International Nuclear Information System (INIS)

Winter, H.; Wolf, B.H.

1974-01-01

A review is given of the operational principles of classical multiply charged ion sources (operating sources for intense beams of multiply charged ions using discharge plasmas; MCIS). The fractional rates of creation of multiply charged ions in MCIS plasmas cannot be deduced from the discharge parameters in a simple manner; they depend essentially on three principal parameters, the density and energy distribution of the ionizing electrons, and the confinement time of ions in the ionization space. Simple discharge models were used to find relations between principal parameters, and results of model calculations are compared to actually measured charge state density distributions of extracted ions. Details of processes which determine the energy distribution of ionizing electrons (heating effects), confinement times of ions (instabilities), and some technical aspects of classical MCIS (cathodes, surface processes, conditioning, life time) are discussed

C2H6 scattering from LiF(0 0 1): Influence of the molecular anisotropy on rainbow scattering in both intensity and speed distributions

International Nuclear Information System (INIS)

Kondo, Takahiro; Tomii, Takashi; Yamamoto, Shigehiko

2006-01-01

We have measured the angle-resolved intensity and speed distributions of C 2 H 6 scattered from LiF(0 0 1) along the [1 0 0] azimuthal direction, the largest structural corrugation direction, to investigate the effect of the molecular anisotropy on the gas-surface interaction at the corrugated surface. While clear rainbow feature is observed in the mean energy angular distribution, no rainbow feature is detected in the intensity angular distribution. From the comparisons of the obtained results to the calculated predictions based on the simple classical theory of the ellipsoid-washboard model, the effect of the molecular anisotropy is found to play a crucial role in the rainbow feature. With an increase in the extent of the molecular anisotropy such as that of C 2 H 6 as compared with rare gas atoms, the integration of the intensity angular distributions for various molecular orientations results in the smearing of the rainbow feature on the corrugated surface. The rainbow scattering in the mean energy angular distribution, however, is not completely smeared out

Detection prospects for high energy neutrino sources from the anisotropic matter distribution in the local Universe

Energy Technology Data Exchange (ETDEWEB)

Mertsch, Philipp; Rameez, Mohamed; Tamborra, Irene, E-mail: mertsch@nbi.ku.dk, E-mail: mohamed.rameez@nbi.ku.dk, E-mail: tamborra@nbi.ku.dk [Niels Bohr International Academy, Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen (Denmark)

2017-03-01

Constraints on the number and luminosity of the sources of the cosmic neutrinos detected by IceCube have been set by targeted searches for point sources. We set complementary constraints by using the 2MASS Redshift Survey (2MRS) catalogue, which maps the matter distribution of the local Universe. Assuming that the distribution of the neutrino sources follows that of matter, we look for correlations between ''warm'' spots on the IceCube skymap and the 2MRS matter distribution. Through Monte Carlo simulations of the expected number of neutrino multiplets and careful modelling of the detector performance (including that of IceCube-Gen2), we demonstrate that sources with local density exceeding 10{sup −6} Mpc{sup −3} and neutrino luminosity L {sub ν} ∼< 10{sup 42} erg s{sup −1} (10{sup 41} erg s{sup −1}) will be efficiently revealed by our method using IceCube (IceCube-Gen2). At low luminosities such as will be probed by IceCube-Gen2, the sensitivity of this analysis is superior to requiring statistically significant direct observation of a point source.

Temperature distribution of a simplified rotor due to a uniform heat source

Science.gov (United States)

Welzenbach, Sarah; Fischer, Tim; Meier, Felix; Werner, Ewald; kyzy, Sonun Ulan; Munz, Oliver

2018-03-01

In gas turbines, high combustion efficiency as well as operational safety are required. Thus, labyrinth seal systems with honeycomb liners are commonly used. In the case of rubbing events in the seal system, the components can be damaged due to cyclic thermal and mechanical loads. Temperature differences occurring at labyrinth seal fins during rubbing events can be determined by considering a single heat source acting periodically on the surface of a rotating cylinder. Existing literature analysing the temperature distribution on rotating cylindrical bodies due to a stationary heat source is reviewed. The temperature distribution on the circumference of a simplified labyrinth seal fin is calculated using an available and easy to implement analytical approach. A finite element model of the simplified labyrinth seal fin is created and the numerical results are compared to the analytical results. The temperature distributions calculated by the analytical and the numerical approaches coincide for low sliding velocities, while there are discrepancies of the calculated maximum temperatures for higher sliding velocities. The use of the analytical approach allows the conservative estimation of the maximum temperatures arising in labyrinth seal fins during rubbing events. At the same time, high calculation costs can be avoided.

Derivation from first principles of the statistical distribution of the mass peak intensities of MS data.

Science.gov (United States)

Ipsen, Andreas

2015-02-03

Despite the widespread use of mass spectrometry (MS) in a broad range of disciplines, the nature of MS data remains very poorly understood, and this places important constraints on the quality of MS data analysis as well as on the effectiveness of MS instrument design. In the following, a procedure for calculating the statistical distribution of the mass peak intensity for MS instruments that use analog-to-digital converters (ADCs) and electron multipliers is presented. It is demonstrated that the physical processes underlying the data-generation process, from the generation of the ions to the signal induced at the detector, and on to the digitization of the resulting voltage pulse, result in data that can be well-approximated by a Gaussian distribution whose mean and variance are determined by physically meaningful instrumental parameters. This allows for a very precise understanding of the signal-to-noise ratio of mass peak intensities and suggests novel ways of improving it. Moreover, it is a prerequisite for being able to address virtually all data analytical problems in downstream analyses in a statistically rigorous manner. The model is validated with experimental data.

North Slope, Alaska: Source rock distribution, richness, thermal maturity, and petroleum charge

Science.gov (United States)

Peters, K.E.; Magoon, L.B.; Bird, K.J.; Valin, Z.C.; Keller, M.A.

2006-01-01

Four key marine petroleum source rock units were identified, characterized, and mapped in the subsurface to better understand the origin and distribution of petroleum on the North Slope of Alaska. These marine source rocks, from oldest to youngest, include four intervals: (1) Middle-Upper Triassic Shublik Formation, (2) basal condensed section in the Jurassic-Lower Cretaceous Kingak Shale, (3) Cretaceous pebble shale unit, and (4) Cretaceous Hue Shale. Well logs for more than 60 wells and total organic carbon (TOC) and Rock-Eval pyrolysis analyses for 1183 samples in 125 well penetrations of the source rocks were used to map the present-day thickness of each source rock and the quantity (TOC), quality (hydrogen index), and thermal maturity (Tmax) of the organic matter. Based on assumptions related to carbon mass balance and regional distributions of TOC, the present-day source rock quantity and quality maps were used to determine the extent of fractional conversion of the kerogen to petroleum and to map the original TOC (TOCo) and the original hydrogen index (HIo) prior to thermal maturation. The quantity and quality of oil-prone organic matter in Shublik Formation source rock generally exceeded that of the other units prior to thermal maturation (commonly TOCo > 4 wt.% and HIo > 600 mg hydrocarbon/g TOC), although all are likely sources for at least some petroleum on the North Slope. We used Rock-Eval and hydrous pyrolysis methods to calculate expulsion factors and petroleum charge for each of the four source rocks in the study area. Without attempting to identify the correct methods, we conclude that calculations based on Rock-Eval pyrolysis overestimate expulsion factors and petroleum charge because low pressure and rapid removal of thermally cracked products by the carrier gas retards cross-linking and pyrobitumen formation that is otherwise favored by natural burial maturation. Expulsion factors and petroleum charge based on hydrous pyrolysis may also be high

A Toolkit For Storage Qos Provisioning For Data-Intensive Applications

Directory of Open Access Journals (Sweden)

Renata Słota

2012-01-01

Full Text Available This paper describes a programming toolkit developed in the PL-Grid project, named QStorMan, which supports storage QoS provisioning for data-intensive applications in distributed environments. QStorMan exploits knowledge-oriented methods for matching storage resources to non-functional requirements, which are defined for a data-intensive application. In order to support various usage scenarios, QStorMan provides two interfaces, such as programming libraries or a web portal. The interfaces allow to define the requirements either directly in an application source code or by using an intuitive graphical interface. The first way provides finer granularity, e.g., each portion of data processed by an application can define a different set of requirements. The second method is aimed at legacy applications support, which source code can not be modified. The toolkit has been evaluated using synthetic benchmarks and the production infrastructure of PL-Grid, in particular its storage infrastructure, which utilizes the Lustre file system.

Light source distribution and scattering phase function influence light transport in diffuse multi-layered media

Science.gov (United States)

Vaudelle, Fabrice; L'Huillier, Jean-Pierre; Askoura, Mohamed Lamine

2017-06-01

Red and near-Infrared light is often used as a useful diagnostic and imaging probe for highly scattering media such as biological tissues, fruits and vegetables. Part of diffusively reflected light gives interesting information related to the tissue subsurface, whereas light recorded at further distances may probe deeper into the interrogated turbid tissues. However, modelling diffusive events occurring at short source-detector distances requires to consider both the distribution of the light sources and the scattering phase functions. In this report, a modified Monte Carlo model is used to compute light transport in curved and multi-layered tissue samples which are covered with a thin and highly diffusing tissue layer. Different light source distributions (ballistic, diffuse or Lambertian) are tested with specific scattering phase functions (modified or not modified Henyey-Greenstein, Gegenbauer and Mie) to compute the amount of backscattered and transmitted light in apple and human skin structures. Comparisons between simulation results and experiments carried out with a multispectral imaging setup confirm the soundness of the theoretical strategy and may explain the role of the skin on light transport in whole and half-cut apples. Other computational results show that a Lambertian source distribution combined with a Henyey-Greenstein phase function provides a higher photon density in the stratum corneum than in the upper dermis layer. Furthermore, it is also shown that the scattering phase function may affect the shape and the magnitude of the Bidirectional Reflectance Distribution (BRDF) exhibited at the skin surface.

High Intensity Polarized Electron Sources

International Nuclear Information System (INIS)

Poelker, Benard; Adderley, Philip; Brittian, Joshua; Clark, J.; Grames, Joseph; Hansknecht, John; McCarter, James; Stutzman, Marcy; Suleiman, Riad; Surles-law, Kenneth

2008-01-01

During the 1990s, at numerous facilities world wide, extensive RandD devoted to constructing reliable GaAs photoguns helped ensure successful accelerator-based nuclear and high-energy physics programs using spin polarized electron beams. Today, polarized electron source technology is considered mature, with most GaAs photoguns meeting accelerator and experiment beam specifications in a relatively trouble-free manner. Proposals for new collider facilities however, require electron beams with parameters beyond today's state-of-the-art and serve to renew interest in conducting polarized electron source RandD. And at CEBAF/Jefferson Lab, there is an immediate pressing need to prepare for new experiments that require considerably more beam current than before. One experiment in particular?Q-weak, a parity violation experiment that will look for physics beyond the Standard Model?requires 180 uA average current at polarization >80% for a duration of one year, with run-averaged helicity correlate

Direct intensity calibration of X-ray grazing-incidence microscopes with home-lab source

Science.gov (United States)

Li, Yaran; Xie, Qing; Chen, Zhiqiang; Xin, Qiuqi; Wang, Xin; Mu, Baozhong; Wang, Zhanshan; Liu, Shenye; Ding, Yongkun

2018-01-01

Direct intensity calibration of X-ray grazing-incidence microscopes is urgently needed in quantitative studies of X-ray emission from laser plasma sources in inertial confinement fusion. The existing calibration methods for single reflecting mirrors, crystals, gratings, filters, and X-ray detectors are not applicable for such X-ray microscopes due to the specific optical structure and the restrictions of object-image relation. This article presents a reliable and efficient method that can be performed using a divergent X-ray source and an energy dispersive Si-PIN (silicon positive-intrinsic-negative) detector in an ordinary X-ray laboratory. The transmission theory of X-ray flux in imaging diagnostics is introduced, and the quantities to be measured are defined. The calibration method is verified by a W/Si multilayer-coated Kirkpatrick-Baez microscope with a field of view of ˜95 μm at 17.48 keV. The mirror reflectance curve in the 1D coordinate is drawn with a peak value of 20.9% and an uncertainty of ˜6.0%.

Dose distribution and dosimetry parameters calculation of MED3633 Palladium-103 source in water phantom using MCNP

International Nuclear Information System (INIS)

Mowlavi, A. A.; Binesh, A.; Moslehitabar, H.

2006-01-01

Palladium-103 ( 103 Pd) is a brachytherapy source for cancer treatment. The Monte Carlo codes are usually applied for dose distribution and effect of shieldings. Monte Carlo calculation of dose distribution in water phantom due to a MED3633 103 Pd source is presented in this work. Materials and Methods: The dose distribution around the 10 3Pd Model MED3633 located in the center of 30*30*30 m 3 water phantom cube was calculated using MCNP code by the Monte Carlo method. The percentage depth dose variation along the different axis parallel and perpendicular to the source was also calculated. Then, the isodose curves for 100%, 75%, 50% and 25% percentage depth dose and dosimetry parameters of TG-43 protocol were determined. Results: The results show that the Monte Carlo Method could calculate dose deposition in high gradient region, near the source, accurately. The isodose curves and dosimetric characteristics obtained for MED3633 103 Pd source are in good agreement with published results. Conclusion: The isodose curves of the MED3633 103 Pd source have been derived form dose calculation by MCNP code. The calculated dosimetry parameters for the source agree quite well with their Monte Carlo calculated and experimental measurement values

Probing the positron moderation process using high-intensity, highly polarized slow-positron beams

Science.gov (United States)

Van House, J.; Zitzewitz, P. W.

1984-01-01

A highly polarized (P = 0.48 + or - 0.02) intense (500,000/sec) beam of 'slow' (Delta E = about 2 eV) positrons (e+) is generated, and it is shown that it is possible to achieve polarization as high as P = 0.69 + or - 0.04 with reduced intensity. The measured polarization of the slow e+ emitted by five different positron moderators showed no dependence on the moderator atomic number (Z). It is concluded that only source positrons with final kinetic energy below 17 keV contribute to the slow-e+ beam, in disagreement with recent yield functions derived from low-energy measurements. Measurements of polarization and yield with absorbers of different Z between the source and moderator show the effects of the energy and angular distributions of the source positrons on P. The depolarization of fast e+ transmitted through high-Z absorbers has been measured. Applications of polarized slow-e+ beams are discussed.

Intensity Maps Production Using Real-Time Joint Streaming Data Processing From Social and Physical Sensors

Science.gov (United States)

Kropivnitskaya, Y. Y.; Tiampo, K. F.; Qin, J.; Bauer, M.

2015-12-01

Intensity is one of the most useful measures of earthquake hazard, as it quantifies the strength of shaking produced at a given distance from the epicenter. Today, there are several data sources that could be used to determine intensity level which can be divided into two main categories. The first category is represented by social data sources, in which the intensity values are collected by interviewing people who experienced the earthquake-induced shaking. In this case, specially developed questionnaires can be used in addition to personal observations published on social networks such as Twitter. These observations are assigned to the appropriate intensity level by correlating specific details and descriptions to the Modified Mercalli Scale. The second category of data sources is represented by observations from different physical sensors installed with the specific purpose of obtaining an instrumentally-derived intensity level. These are usually based on a regression of recorded peak acceleration and/or velocity amplitudes. This approach relates the recorded ground motions to the expected felt and damage distribution through empirical relationships. The goal of this work is to implement and evaluate streaming data processing separately and jointly from both social and physical sensors in order to produce near real-time intensity maps and compare and analyze their quality and evolution through 10-minute time intervals immediately following an earthquake. Results are shown for the case study of the M6.0 2014 South Napa, CA earthquake that occurred on August 24, 2014. The using of innovative streaming and pipelining computing paradigms through IBM InfoSphere Streams platform made it possible to read input data in real-time for low-latency computing of combined intensity level and production of combined intensity maps in near-real time. The results compare three types of intensity maps created based on physical, social and combined data sources. Here we correlate

Broadband frequency ECR ion source concepts with large resonant plasma volumes

International Nuclear Information System (INIS)

Alton, G.D.

1995-01-01

New techniques are proposed for enhancing the performances of ECR ion sources. The techniques are based on the use of high-power, variable-frequency, multiple-discrete-frequency, or broadband microwave radiation, derived from standard TWT technology, to effect large resonant ''volume'' ECR sources. The creation of a large ECR plasma ''volume'' permits coupling of more power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present forms of the ECR ion source. If successful, these developments could significantly impact future accelerator designs and accelerator-based, heavy-ion-research programs by providing multiply-charged ion beams with the energies and intensities required for nuclear physics research from existing ECR ion sources. The methods described in this article can be used to retrofit any ECR ion source predicated on B-minimum plasma confinement techniques

FDTD verification of deep-set brain tumor hyperthermia using a spherical microwave source distribution

Energy Technology Data Exchange (ETDEWEB)

Dunn, D. [20th Intelligence Squadron, Offutt AFB, NE (United States); Rappaport, C.M. [Northeastern Univ., Boston, MA (United States). Center for Electromagnetics Research; Terzuoli, A.J. Jr. [Air Force Inst. of Tech., Dayton, OH (United States). Graduate School of Engineering

1996-10-01

Although use of noninvasive microwave hyperthermia to treat cancer is problematic in many human body structures, careful selection of the source electric field distribution around the entire surface of the head can generate a tightly focused global power density maximum at the deepest point within the brain. An analytic prediction of the optimum volume field distribution in a layered concentric head model based on summing spherical harmonic modes is derived and presented. This ideal distribution is then verified using a three-dimensional finite difference time domain (TDTD) simulation with a discretized, MRI-based head model excited by the spherical source. The numerical computation gives a very similar dissipated power pattern as the analytic prediction. This study demonstrates that microwave hyperthermia can theoretically be a feasible cancer treatment modality for tumors in the head, providing a well-resolved hot-spot at depth without overheating any other healthy tissue.

High-Intensity Radiated Field Fault-Injection Experiment for a Fault-Tolerant Distributed Communication System

Science.gov (United States)

Yates, Amy M.; Torres-Pomales, Wilfredo; Malekpour, Mahyar R.; Gonzalez, Oscar R.; Gray, W. Steven

2010-01-01

Safety-critical distributed flight control systems require robustness in the presence of faults. In general, these systems consist of a number of input/output (I/O) and computation nodes interacting through a fault-tolerant data communication system. The communication system transfers sensor data and control commands and can handle most faults under typical operating conditions. However, the performance of the closed-loop system can be adversely affected as a result of operating in harsh environments. In particular, High-Intensity Radiated Field (HIRF) environments have the potential to cause random fault manifestations in individual avionic components and to generate simultaneous system-wide communication faults that overwhelm existing fault management mechanisms. This paper presents the design of an experiment conducted at the NASA Langley Research Center's HIRF Laboratory to statistically characterize the faults that a HIRF environment can trigger on a single node of a distributed flight control system.

Data acquisition system for the neutron scattering instruments at the intense pulsed neutron source

International Nuclear Information System (INIS)

Crawford, R.K.; Daly, R.T.; Haumann, J.R.; Hitterman, R.L.; Morgan, C.B.; Ostrowski, G.E.; Worlton, T.G.

1981-01-01

The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a major new user-oriented facility which is now coming on line for basic research in neutron scattering and neutron radiation damage. This paper describes the data-acquisition system which will handle data acquisition and instrument control for the time-of-flight neutron-scattering instruments at IPNS. This discussion covers the scientific and operational requirements for this system, and the system architecture that was chosen to satisfy these requirements. It also provides an overview of the current system implementation including brief descriptions of the hardware and software which have been developed

Low-Complexity Compression Algorithm for Hyperspectral Images Based on Distributed Source Coding

Directory of Open Access Journals (Sweden)

Yongjian Nian

2013-01-01

Full Text Available A low-complexity compression algorithm for hyperspectral images based on distributed source coding (DSC is proposed in this paper. The proposed distributed compression algorithm can realize both lossless and lossy compression, which is implemented by performing scalar quantization strategy on the original hyperspectral images followed by distributed lossless compression. Multilinear regression model is introduced for distributed lossless compression in order to improve the quality of side information. Optimal quantized step is determined according to the restriction of the correct DSC decoding, which makes the proposed algorithm achieve near lossless compression. Moreover, an effective rate distortion algorithm is introduced for the proposed algorithm to achieve low bit rate. Experimental results show that the compression performance of the proposed algorithm is competitive with that of the state-of-the-art compression algorithms for hyperspectral images.

A practical two-way system of quantum key distribution with untrusted source

International Nuclear Information System (INIS)

Chen Ming-Juan; Liu Xiang

2011-01-01

The most severe problem of a two-way 'plug-and-play' (p and p) quantum key distribution system is that the source can be controlled by the eavesdropper. This kind of source is defined as an “untrusted source . This paper discusses the effects of the fluctuation of internal transmittance on the final key generation rate and the transmission distance. The security of the standard BB84 protocol, one-decoy state protocol, and weak+vacuum decoy state protocol, with untrusted sources and the fluctuation of internal transmittance are studied. It is shown that the one-decoy state is sensitive to the statistical fluctuation but weak+vacuum decoy state is only slightly affected by the fluctuation. It is also shown that both the maximum secure transmission distance and final key generation rate are reduced when Alice's laboratory transmittance fluctuation is considered. (general)

Tagging moisture sources with Lagrangian and inertial tracers: application to intense atmospheric river events

Directory of Open Access Journals (Sweden)

V. Pérez-Muñuzuri

2018-06-01

Full Text Available Two Lagrangian tracer tools are evaluated for studies on atmospheric moisture sources and pathways. In these methods, a moisture volume is assigned to each particle, which is then advected by the wind flow. Usual Lagrangian methods consider this volume to remain constant and the particle to follow flow path lines exactly. In a different approach, the initial moisture volume can be considered to depend on time as it is advected by the flow due to thermodynamic processes. In this case, the tracer volume drag must be taken into account. Equations have been implemented and moisture convection was taken into account for both Lagrangian and inertial models. We apply these methods to evaluate the intense atmospheric rivers that devastated (i the Pacific Northwest region of the US and (ii the western Iberian Peninsula with flooding rains and intense winds in early November 2006 and 20 May 1994, respectively. We note that the usual Lagrangian method underestimates moisture availability in the continent, while active tracers achieve more realistic results.

Total grain-size distribution of four subplinian-Plinian tephras from Hekla volcano, Iceland: Implications for sedimentation dynamics and eruption source parameters

Science.gov (United States)

Janebo, Maria H.; Houghton, Bruce F.; Thordarson, Thorvaldur; Bonadonna, Costanza; Carey, Rebecca J.

2018-05-01

The size distribution of the population of particles injected into the atmosphere during a volcanic explosive eruption, i.e., the total grain-size distribution (TGSD), can provide important insights into fragmentation efficiency and is a fundamental source parameter for models of tephra dispersal and sedimentation. Recent volcanic crisis (e.g. Eyjafjallajökull 2010, Iceland and Córdon Caulle 2011, Chile) and the ensuing economic losses, highlighted the need for a better constraint of eruption source parameters to be used in real-time forecasting of ash dispersal (e.g., mass eruption rate, plume height, particle features), with a special focus on the scarcity of published TGSD in the scientific literature. Here we present TGSD data associated with Hekla volcano, which has been very active in the last few thousands of years and is located on critical aviation routes. In particular, we have reconstructed the TGSD of the initial subplinian-Plinian phases of four historical eruptions, covering a range of magma composition (andesite to rhyolite), eruption intensity (VEI 4 to 5), and erupted volume (0.2 to 1 km3). All four eruptions have bimodal TGSDs with mass fraction of fine ash (primary fragmentation. Due to differences in plume height, this contrast is not seen in samples from individual sites, especially in the near field, where lapilli have a wider spatial coverage in the Plinian deposits. The distribution of pyroclast sizes in Plinian versus subplinian falls reflects competing influences of more efficient fragmentation (e.g., producing larger amounts of fine ash) versus more efficient particle transport related to higher and more vigorous plumes, displacing relatively coarse lapilli farther down the dispersal axis.

Mathematical simulation of gamma-radiation angle distribution measurements

International Nuclear Information System (INIS)

Batij, V.G.; Batij, E.V.; Egorov, V.V.; Fedorchenko, D.V.; Kochnev, N.A.

2008-01-01

We developed mathematical model of the facility for gamma-radiation angle distribution measurement and calculated response functions for gamma-radiation intensities. We developed special software for experimental data processing, the 'Shelter' object radiation spectra unfolding and Sphere detector (ShD) angle resolution estimation. Neuronet method using for detection of the radiation directions is given. We developed software based on the neuronet algorithm, that allows obtaining reliable distribution of gamma-sources that make impact on the facility detectors at the measurement point. 10 refs.; 15 figs.; 4 tab

The GIS and analysis of earthquake damage distribution of the 1303 Hongtong M=8 earthquake

Science.gov (United States)

Gao, Meng-Tan; Jin, Xue-Shen; An, Wei-Ping; Lü, Xiao-Jian

2004-07-01

The geography information system of the 1303 Hongton M=8 earthquake has been established. Using the spatial analysis function of GIS, the spatial distribution characteristics of damage and isoseismal of the earthquake are studies. By comparing with the standard earthquake intensity attenuation relationship, the abnormal damage distribution of the earthquake is found, so the relationship of the abnormal distribution with tectonics, site condition and basin are analyzed. In this paper, the influence on the ground motion generated by earthquake source and the underground structures near source also are studied. The influence on seismic zonation, anti-earthquake design, earthquake prediction and earthquake emergency responding produced by the abnormal density distribution are discussed.

Electron Cloud induced instabilities in the Fermilab Main Injector(MI) for the High Intensity Neutrino Source (HINS) project

International Nuclear Information System (INIS)

Sonnad, Kiran G.; Furman, Miguel A.; Vay, Jean-Luc; Venturini, Marco; Celata, Christine; Grote, David

2006-01-01

The electrostatic particle-in-cell codeWARP is currently being expanded in order to study electron cloud effects on the dynamics of the beam in storage rings. Results for the Fermilab main injector (MI) show the existence of a threshold in the electron density beyond which there is rapid emittance growth. The Fermilab MI is being considered for an upgrade as part of the high intensity neutrino source (HINS) effort, which will result in a significant increasing of the bunch intensity relative to its present value, placing it in a regime where electron-cloud effects are expected to become important. Various results from the simulations using WARP are discussed here

Inverse modelling of fluvial sediment connectivity identifies characteristics and spatial distribution of sediment sources in a large river network.

Science.gov (United States)

Schmitt, R. J. P.; Bizzi, S.; Kondolf, G. M.; Rubin, Z.; Castelletti, A.

2016-12-01

Field and laboratory evidence indicates that the spatial distribution of transport in both alluvial and bedrock rivers is an adaptation to sediment supply. Sediment supply, in turn, depends on spatial distribution and properties (e.g., grain sizes and supply rates) of individual sediment sources. Analyzing the distribution of transport capacity in a river network could hence clarify the spatial distribution and properties of sediment sources. Yet, challenges include a) identifying magnitude and spatial distribution of transport capacity for each of multiple grain sizes being simultaneously transported, and b) estimating source grain sizes and supply rates, both at network scales. Herein, we approach the problem of identifying the spatial distribution of sediment sources and the resulting network sediment fluxes in a major, poorly monitored tributary (80,000 km2) of the Mekong. Therefore, we apply the CASCADE modeling framework (Schmitt et al. (2016)). CASCADE calculates transport capacities and sediment fluxes for multiple grainsizes on the network scale based on remotely-sensed morphology and modelled hydrology. CASCADE is run in an inverse Monte Carlo approach for 7500 random initializations of source grain sizes. In all runs, supply of each source is inferred from the minimum downstream transport capacity for the source grain size. Results for each realization are compared to sparse available sedimentary records. Only 1 % of initializations reproduced the sedimentary record. Results for these realizations revealed a spatial pattern in source supply rates, grain sizes, and network sediment fluxes that correlated well with map-derived patterns in lithology and river-morphology. Hence, we propose that observable river hydro-morphology contains information on upstream source properties that can be back-calculated using an inverse modeling approach. Such an approach could be coupled to more detailed models of hillslope processes in future to derive integrated models

Distributions of emissions intensity for individual beef cattle reared on pasture-based production systems.

Science.gov (United States)

McAuliffe, G A; Takahashi, T; Orr, R J; Harris, P; Lee, M R F

2018-01-10

Life Cycle Assessment (LCA) of livestock production systems is often based on inventory data for farms typical of a study region. As information on individual animals is often unavailable, livestock data may already be aggregated at the time of inventory analysis, both across individual animals and across seasons. Even though various computational tools exist to consider the effect of genetic and seasonal variabilities in livestock-originated emissions intensity, the degree to which these methods can address the bias suffered by representative animal approaches is not well-understood. Using detailed on-farm data collected on the North Wyke Farm Platform (NWFP) in Devon, UK, this paper proposes a novel approach of life cycle impact assessment that complements the existing LCA methodology. Field data, such as forage quality and animal performance, were measured at high spatial and temporal resolutions and directly transferred into LCA processes. This approach has enabled derivation of emissions intensity for each individual animal and, by extension, its intra-farm distribution, providing a step towards reducing uncertainty related to agricultural production inherent in LCA studies for food. Depending on pasture management strategies, the total emissions intensity estimated by the proposed method was higher than the equivalent value recalculated using a representative animal approach by 0.9-1.7 kg CO 2 -eq/kg liveweight gain, or up to 10% of system-wide emissions. This finding suggests that emissions intensity values derived by the latter technique may be underestimated due to insufficient consideration given to poorly performing animals, whose emissions becomes exponentially greater as average daily gain decreases. Strategies to mitigate life-cycle environmental impacts of pasture-based beef productions systems are also discussed.

Herschel-ATLAS: Dust Temperature and Redshift Distribution of SPIRE and PACS Detected Sources Using Submillimetre Colours

Science.gov (United States)

Amblard, A.; Cooray, Asantha; Serra, P.; Temi, P.; Barton, E.; Negrello, M.; Auld, R.; Baes, M.; Baldry, I. K.; Bamford, S.;

Installation of spectrally selective imaging system in RF negative ion source

International Nuclear Information System (INIS)

Ikeda, K.; Kisaki, M.; Nagaoka, K.; Nakano, H.; Osakabe, M.; Tsumori, K.; Kaneko, O.; Takeiri, Y.; Wünderlich, D.; Fantz, U.; Heinemann, B.; Geng, S.

2016-01-01

A spectrally selective imaging system has been installed in the RF negative ion source in the International Thermonuclear Experimental Reactor-relevant negative ion beam test facility ELISE (Extraction from a Large Ion Source Experiment) to investigate distribution of hydrogen Balmer-α emission (H α ) close to the production surface of hydrogen negative ion. We selected a GigE vision camera coupled with an optical band-path filter, which can be controlled remotely using high speed network connection. A distribution of H α emission near the bias plate has been clearly observed. The same time trend on H α intensities measured by the imaging diagnostic and the optical emission spectroscopy is confirmed

Molecular beam (1-50eV) production by duoplasmatron source

International Nuclear Information System (INIS)

Delmas, M.; Gautherin, G.; Lejeune, C.

1974-01-01

The duoplasmatron discharge is commonly used to produce intense ion beams. A theoretical model of this discharge has been previously developed. The analysis of charge exchange processes between ions and neutral within the discharge shows that the source is able to deliver intense neutral beams (10 16 part s -1 ), the energy being in the range 1-50 eV. The intensity and energy distribution may be controlled from the discharge parameter variations. An experimental device has been realized in order to separate the neutral beam and the flux of charged particles; these latter are injected axially in a toroidal magnetic field configuration [fr

Model of charge-state distributions for electron cyclotron resonance ion source plasmas

Directory of Open Access Journals (Sweden)

D. H. Edgell

1999-12-01

Full Text Available A computer model for the ion charge-state distribution (CSD in an electron cyclotron resonance ion source (ECRIS plasma is presented that incorporates non-Maxwellian distribution functions, multiple atomic species, and ion confinement due to the ambipolar potential well that arises from confinement of the electron cyclotron resonance (ECR heated electrons. Atomic processes incorporated into the model include multiple ionization and multiple charge exchange with rate coefficients calculated for non-Maxwellian electron distributions. The electron distribution function is calculated using a Fokker-Planck code with an ECR heating term. This eliminates the electron temperature as an arbitrary user input. The model produces results that are a good match to CSD data from the ANL-ECRII ECRIS. Extending the model to 1D axial will also allow the model to determine the plasma and electrostatic potential profiles, further eliminating arbitrary user input to the model.

Quantum key distribution with an efficient countermeasure against correlated intensity fluctuations in optical pulses

Science.gov (United States)

Yoshino, Ken-ichiro; Fujiwara, Mikio; Nakata, Kensuke; Sumiya, Tatsuya; Sasaki, Toshihiko; Takeoka, Masahiro; Sasaki, Masahide; Tajima, Akio; Koashi, Masato; Tomita, Akihisa

2018-03-01

Quantum key distribution (QKD) allows two distant parties to share secret keys with the proven security even in the presence of an eavesdropper with unbounded computational power. Recently, GHz-clock decoy QKD systems have been realized by employing ultrafast optical communication devices. However, security loopholes of high-speed systems have not been fully explored yet. Here we point out a security loophole at the transmitter of the GHz-clock QKD, which is a common problem in high-speed QKD systems using practical band-width limited devices. We experimentally observe the inter-pulse intensity correlation and modulation pattern-dependent intensity deviation in a practical high-speed QKD system. Such correlation violates the assumption of most security theories. We also provide its countermeasure which does not require significant changes of hardware and can generate keys secure over 100 km fiber transmission. Our countermeasure is simple, effective and applicable to wide range of high-speed QKD systems, and thus paves the way to realize ultrafast and security-certified commercial QKD systems.

Fire Source Localization Based on Distributed Temperature Sensing by a Dual-Line Optical Fiber System

Directory of Open Access Journals (Sweden)

Miao Sun

2016-06-01

Full Text Available We propose a method for localizing a fire source using an optical fiber distributed temperature sensor system. A section of two parallel optical fibers employed as the sensing element is installed near the ceiling of a closed room in which the fire source is located. By measuring the temperature of hot air flows, the problem of three-dimensional fire source localization is transformed to two dimensions. The method of the source location is verified with experiments using burning alcohol as fire source, and it is demonstrated that the method represents a robust and reliable technique for localizing a fire source also for long sensing ranges.

Fire Source Localization Based on Distributed Temperature Sensing by a Dual-Line Optical Fiber System.

Science.gov (United States)

Sun, Miao; Tang, Yuquan; Yang, Shuang; Li, Jun; Sigrist, Markus W; Dong, Fengzhong

2016-06-06

We propose a method for localizing a fire source using an optical fiber distributed temperature sensor system. A section of two parallel optical fibers employed as the sensing element is installed near the ceiling of a closed room in which the fire source is located. By measuring the temperature of hot air flows, the problem of three-dimensional fire source localization is transformed to two dimensions. The method of the source location is verified with experiments using burning alcohol as fire source, and it is demonstrated that the method represents a robust and reliable technique for localizing a fire source also for long sensing ranges.

137Cs source dose distribution using the Fricke Xylenol Gel dosimetry

International Nuclear Information System (INIS)

Sato, R.; De Almeida, A.; Moreira, M.V.

2009-01-01

Dosimetric measurements close to radioisotope sources, such as those used in brachytherapy, require high spatial resolution to avoid incorrect results in the steep dose gradient region. In this work the Fricke Xylenol Gel dosimeter was used to obtain the spatial dose distribution. The readings from a 137 Cs source were performed using two methods, visible spectrophotometer and CCD camera images. Good agreement with the Sievert summation method was found for the transversal axis dose profile within uncertainties of 4% and 5%, for the spectrophotometer and CCD camera respectively. Our results show that the dosimeter is adequate for brachytherapy dosimetry and, owing to its relatively fast and easy preparation and reading, it is recommended for quality control in brachytherapy applications.

Target micro-displacement measurement by a "comb" structure of intensity distribution in laser plasma propulsion

Science.gov (United States)

Zheng, Z. Y.; Zhang, S. Q.; Gao, L.; Gao, H.

2015-05-01

A "comb" structure of beam intensity distribution is designed and achieved to measure a target displacement of micrometer level in laser plasma propulsion. Base on the "comb" structure, the target displacement generated by nanosecond laser ablation solid target is measured and discussed. It is found that the "comb" structure is more suitable for a thin film target with a velocity lower than tens of millimeters per second. Combing with a light-electric monitor, the `comb' structure can be used to measure a large range velocity.

Intense, broadband, pulsed I-R source at the National Synchrotron Light Source

International Nuclear Information System (INIS)

Williams, G.P.

1984-01-01

We describe a broadband (1 μm to 1 mm) synchrotron radiation infrared source, pulsed each 20 to 180 nseconds and delivering about 10 15 photons/sec/1% bandpass into f10 optics. The source size is diffraction limited. This source is thus 100 to 1000 times brighter than a 2000 0 K black body, very stable and capable of being used for calibration

Cross correlations of quantum key distribution based on single-photon sources

International Nuclear Information System (INIS)

Dong Shuangli; Wang Xiaobo; Zhang Guofeng; Sun Jianhu; Zhang Fang; Xiao Liantuan; Jia Suotang

2009-01-01

We theoretically analyze the second-order correlation function in a quantum key distribution system with real single-photon sources. Based on single-event photon statistics, the influence of the modification caused by an eavesdropper's intervention and the effects of background signals on the cross correlations between authorized partners are presented. On this basis, we have shown a secure range of correlation against the intercept-resend attacks.

Characterization of a gamma-ray source based on a laser-plasma accelerator with applications to radiography

International Nuclear Information System (INIS)

Edwards, R.D.; Sinclair, M.A.; Goldsack, T.J.; Krushelnick, K.; Beg, F.N.; Clark, E.L.; Dangor, A.E.; Najmudin, Z.; Tatarakis, M.; Walton, B.; Zepf, M.; Ledingham, K.W.D.; Spencer, I.; Norreys, P.A.; Clarke, R.J.; Kodama, R.; Toyama, Y.; Tampo, M.

2002-01-01

The application of high intensity laser-produced gamma rays is discussed with regard to picosecond resolution deep-penetration radiography. The spectrum and angular distribution of these gamma rays is measured using an array of thermoluminescent detectors for both an underdense (gas) target and an overdense (solid) target. It is found that the use of an underdense target in a laser plasma accelerator configuration produces a much more intense and directional source. The peak dose is also increased significantly. Radiography is demonstrated in these experiments and the source size is also estimated

Studies on the supposition of liquid source for irradiation and its dose distribution, (1)

International Nuclear Information System (INIS)

Yoshimura, Seiji; Nishida, Tsuneo

1977-01-01

Recently radio isotope has been used and applied in the respective spheres. The application of the effects by irradiation will be specially paid attention to in the future. Today the source for irradiation has been considered to be the thing sealed in the solid state into various capsules. So we suppose that we use liquid radio isotope as the source for irradiation. This is because there are some advantages compared with the solid source in its freedom of the shape or additional easiness at attenuation. In these experiments we measured the dose distribution by the columnar liquid source. We expect that these will be put to practical use. (auth.)

D-DSC: Decoding Delay-based Distributed Source Coding for Internet of Sensing Things.

Science.gov (United States)

Aktas, Metin; Kuscu, Murat; Dinc, Ergin; Akan, Ozgur B

2018-01-01

Spatial correlation between densely deployed sensor nodes in a wireless sensor network (WSN) can be exploited to reduce the power consumption through a proper source coding mechanism such as distributed source coding (DSC). In this paper, we propose the Decoding Delay-based Distributed Source Coding (D-DSC) to improve the energy efficiency of the classical DSC by employing the decoding delay concept which enables the use of the maximum correlated portion of sensor samples during the event estimation. In D-DSC, network is partitioned into clusters, where the clusterheads communicate their uncompressed samples carrying the side information, and the cluster members send their compressed samples. Sink performs joint decoding of the compressed and uncompressed samples and then reconstructs the event signal using the decoded sensor readings. Based on the observed degree of the correlation among sensor samples, the sink dynamically updates and broadcasts the varying compression rates back to the sensor nodes. Simulation results for the performance evaluation reveal that D-DSC can achieve reliable and energy-efficient event communication and estimation for practical signal detection/estimation applications having massive number of sensors towards the realization of Internet of Sensing Things (IoST).

Multi-source analysis reveals latitudinal and altitudinal shifts in range of Ixodes ricinus at its northern distribution limit

Directory of Open Access Journals (Sweden)

Kristoffersen Anja B

2011-05-01

Full Text Available Abstract Background There is increasing evidence for a latitudinal and altitudinal shift in the distribution range of Ixodes ricinus. The reported incidence of tick-borne disease in humans is on the rise in many European countries and has raised political concern and attracted media attention. It is disputed which factors are responsible for these trends, though many ascribe shifts in distribution range to climate changes. Any possible climate effect would be most easily noticeable close to the tick's geographical distribution limits. In Norway- being the northern limit of this species in Europe- no documentation of changes in range has been published. The objectives of this study were to describe the distribution of I. ricinus in Norway and to evaluate if any range shifts have occurred relative to historical descriptions. Methods Multiple data sources - such as tick-sighting reports from veterinarians, hunters, and the general public - and surveillance of human and animal tick-borne diseases were compared to describe the present distribution of I. ricinus in Norway. Correlation between data sources and visual comparison of maps revealed spatial consistency. In order to identify the main spatial pattern of tick abundance, a principal component analysis (PCA was used to obtain a weighted mean of four data sources. The weighted mean explained 67% of the variation of the data sources covering Norway's 430 municipalities and was used to depict the present distribution of I. ricinus. To evaluate if any geographical range shift has occurred in recent decades, the present distribution was compared to historical data from 1943 and 1983. Results Tick-borne disease and/or observations of I. ricinus was reported in municipalities up to an altitude of 583 metres above sea level (MASL and is now present in coastal municipalities north to approximately 69°N. Conclusion I. ricinus is currently found further north and at higher altitudes than described in

An intense lithium ion beam source using vacuum baking and discharge cleaning techniques

International Nuclear Information System (INIS)

Moschella, J.J.; Kusse, B.R.; Longfellow, J.P.; Olson, J.C.

1991-01-01

We have developed a high-purity, intense, lithium ion beam source which operates at 500 kV and 120 A/cm 2 with pulse widths of 125 ns full width half maximum. The beams were generated using a lithium chloride anode in planar magnetically insulated geometry. We have found that the combination of vacuum baking of the anode at 250 degree C followed by the application of 100 W of pure argon, steady-state, glow discharge cleaning reduced the impurity concentration in the beam to approximately 10% (components other than chlorine or lithium were considered impurities). Although the impurities were low, the concentration of chlorine in the 1+ and 2+ charge states was significant (∼25%). The remaining 65% of the beam consisted of Li + ions. Without the special cleaning process, over half the beam particles were impurities. It was determined that these impurities entered the beam at the anode surface but came originally from material in the vacuum chamber. After the cleaning process, recontamination was observed to occur in approximately 6 min. This long recontamination time, which was much greater than the expected monolayer formation time, was attributed to the elevated temperature of the anode. We also compared the electrical characteristics of the beams produced by LiCl anodes to those generated by a standard polyethylene proton source. In contrast to the polyethylene anode, the LiCl source exhibited a higher impedance, produced beams of lower ion current efficiency and had longer turn on times

A realistic multimodal modeling approach for the evaluation of distributed source analysis: application to sLORETA

Science.gov (United States)

Cosandier-Rimélé, D.; Ramantani, G.; Zentner, J.; Schulze-Bonhage, A.; Dümpelmann, M.

2017-10-01

Objective. Electrical source localization (ESL) deriving from scalp EEG and, in recent years, from intracranial EEG (iEEG), is an established method in epilepsy surgery workup. We aimed to validate the distributed ESL derived from scalp EEG and iEEG, particularly regarding the spatial extent of the source, using a realistic epileptic spike activity simulator. Approach. ESL was applied to the averaged scalp EEG and iEEG spikes of two patients with drug-resistant structural epilepsy. The ESL results for both patients were used to outline the location and extent of epileptic cortical patches, which served as the basis for designing a spatiotemporal source model. EEG signals for both modalities were then generated for different anatomic locations and spatial extents. ESL was subsequently performed on simulated signals with sLORETA, a commonly used distributed algorithm. ESL accuracy was quantitatively assessed for iEEG and scalp EEG. Main results. The source volume was overestimated by sLORETA at both EEG scales, with the error increasing with source size, particularly for iEEG. For larger sources, ESL accuracy drastically decreased, and reconstruction volumes shifted to the center of the head for iEEG, while remaining stable for scalp EEG. Overall, the mislocalization of the reconstructed source was more pronounced for iEEG. Significance. We present a novel multiscale framework for the evaluation of distributed ESL, based on realistic multiscale EEG simulations. Our findings support that reconstruction results for scalp EEG are often more accurate than for iEEG, owing to the superior 3D coverage of the head. Particularly the iEEG-derived reconstruction results for larger, widespread generators should be treated with caution.

A realistic multimodal modeling approach for the evaluation of distributed source analysis: application to sLORETA.

Science.gov (United States)

Cosandier-Rimélé, D; Ramantani, G; Zentner, J; Schulze-Bonhage, A; Dümpelmann, M

2017-10-01

Electrical source localization (ESL) deriving from scalp EEG and, in recent years, from intracranial EEG (iEEG), is an established method in epilepsy surgery workup. We aimed to validate the distributed ESL derived from scalp EEG and iEEG, particularly regarding the spatial extent of the source, using a realistic epileptic spike activity simulator. ESL was applied to the averaged scalp EEG and iEEG spikes of two patients with drug-resistant structural epilepsy. The ESL results for both patients were used to outline the location and extent of epileptic cortical patches, which served as the basis for designing a spatiotemporal source model. EEG signals for both modalities were then generated for different anatomic locations and spatial extents. ESL was subsequently performed on simulated signals with sLORETA, a commonly used distributed algorithm. ESL accuracy was quantitatively assessed for iEEG and scalp EEG. The source volume was overestimated by sLORETA at both EEG scales, with the error increasing with source size, particularly for iEEG. For larger sources, ESL accuracy drastically decreased, and reconstruction volumes shifted to the center of the head for iEEG, while remaining stable for scalp EEG. Overall, the mislocalization of the reconstructed source was more pronounced for iEEG. We present a novel multiscale framework for the evaluation of distributed ESL, based on realistic multiscale EEG simulations. Our findings support that reconstruction results for scalp EEG are often more accurate than for iEEG, owing to the superior 3D coverage of the head. Particularly the iEEG-derived reconstruction results for larger, widespread generators should be treated with caution.

Enhancing the performance of the measurement-device-independent quantum key distribution with heralded pair-coherent sources

Energy Technology Data Exchange (ETDEWEB)

Zhu, Feng; Zhang, Chun-Hui; Liu, Ai-Ping [Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications, Nanjing 210003 (China); Key Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003 (China); Wang, Qin, E-mail: qinw@njupt.edu.cn [Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications, Nanjing 210003 (China); Key Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003 (China); Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026 (China)

2016-04-01

In this paper, we propose to implement the heralded pair-coherent source into the measurement-device-independent quantum key distribution. By comparing its performance with other existing schemes, we demonstrate that our new scheme can overcome many shortcomings existing in current schemes, and show excellent behavior in the quantum key distribution. Moreover, even when taking the statistical fluctuation into account, we can still obtain quite high key generation rate at very long transmission distance by using our new scheme. - Highlights: • Implement the heralded pair-coherent source into the measurement-device-independent quantum key distribution. • Overcome many shortcomings existing in current schemes and show excellent behavior. • Obtain quite high key generation rate even when taking statistical fluctuation into account.

A stationary computed tomography system with cylindrically distributed sources and detectors.

Science.gov (United States)

Chen, Yi; Xi, Yan; Zhao, Jun

2014-01-01

The temporal resolution of current computed tomography (CT) systems is limited by the rotation speed of their gantries. A helical interlaced source detector array (HISDA) CT, which is a stationary CT system with distributed X-ray sources and detectors, is presented in this paper to overcome the aforementioned limitation and achieve high temporal resolution. Projection data can be obtained from different angles in a short time and do not require source, detector, or object motion. Axial coverage speed is increased further by employing a parallel scan scheme. Interpolation is employed to approximate the missing data in the gaps, and then a Katsevich-type reconstruction algorithm is applied to enable an approximate reconstruction. The proposed algorithm suppressed the cone beam and gap-induced artifacts in HISDA CT. The results also suggest that gap-induced artifacts can be reduced by employing a large helical pitch for a fixed gap height. HISDA CT is a promising 3D dynamic imaging architecture given its good temporal resolution and stationary advantage.

SWAT application in intensive irrigation systems: Model modification, calibration and validation

OpenAIRE

Dechmi, Farida; Burguete, Javier; Skhiri, Ahmed

2012-01-01

The Soil and Water Assessment Tool (SWAT) is a well established, distributed, eco-hydrologic model. However, using the study case of an agricultural intensive irrigated watershed, it was shown that all the model versions are not able to appropriately reproduce the total streamflow in such system when the irrigation source is outside the watershed. The objective of this study was to modify the SWAT2005 version for correctly simulating the main hydrological processes. Crop yield, total streamfl...

THE FEATURES OF LASER EMISSION ENERGY DISTRIBUTION AT MATHEMATIC MODELING OF WORKING PROCESS

Directory of Open Access Journals (Sweden)

A. M. Avsiyevich

2013-01-01

Full Text Available The space laser emission energy distribution of different continuous operation settings depends from many factors, first on the settings design. For more accurate describing of multimode laser emission energy distribution intensity the experimental and theoretic model, which based on experimental laser emission distribution shift presentation with given accuracy rating in superposition basic function form, is proposed. This model provides the approximation error only 2,2 percent as compared with 24,6 % and 61 % for uniform and Gauss approximation accordingly. The proposed model usage lets more accurate take into consideration the laser emission and working surface interaction peculiarity, increases temperature fields calculation accuracy for mathematic modeling of laser treatment processes. The method of experimental laser emission energy distribution studying for given source and mathematic apparatus for calculation of laser emission energy distribution intensity parameters depended from the distance in radial direction on surface heating zone are shown.

Geometric discretization of the multidimensional Dirac delta distribution - Application to the Poisson equation with singular source terms

Science.gov (United States)

Egan, Raphael; Gibou, Frédéric

2017-10-01

We present a discretization method for the multidimensional Dirac distribution. We show its applicability in the context of integration problems, and for discretizing Dirac-distributed source terms in Poisson equations with constant or variable diffusion coefficients. The discretization is cell-based and can thus be applied in a straightforward fashion to Quadtree/Octree grids. The method produces second-order accurate results for integration. Superlinear convergence is observed when it is used to model Dirac-distributed source terms in Poisson equations: the observed order of convergence is 2 or slightly smaller. The method is consistent with the discretization of Dirac delta distribution for codimension one surfaces presented in [1,2]. We present Quadtree/Octree construction procedures to preserve convergence and present various numerical examples, including multi-scale problems that are intractable with uniform grids.

The dislocation distribution function near a crack tip generated by external sources

International Nuclear Information System (INIS)

Lung, C.W.; Deng, K.M.

1988-06-01

The dislocation distribution function near a crack tip generated by external sources is calculated. It is similar to the shape of curves calculated for the crack tip emission case but the quantative difference is quite large. The image forces enlarges the negative dislocation zone but does not change the form of the curve. (author). 10 refs, 3 figs

Determination of Key Risk Supervision Areas around River-Type Water Sources Affected by Multiple Risk Sources: A Case Study of Water Sources along the Yangtze’s Nanjing Section

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Qi Zhou

2017-02-01

Full Text Available To provide a reference for risk management of water sources, this study screens the key risk supervision areas around river-type water sources (hereinafter referred to as the water sources threatened by multiple fixed risk sources (the risk sources, and establishes a comprehensive methodological system. Specifically, it comprises: (1 method of partitioning risk source concentrated sub-regions for screening water source perimeter key risk supervision areas; (2 approach of determining sub-regional risk indexes (SrRI, which characterizes the scale of sub-regional risks considering factors like risk distribution intensity within sub-regions, risk indexes of risk sources (RIRS, characterizing the risk scale of risk sources and the number of risk sources; and (3 method of calculating sub-region’s risk threats to the water sources (SrTWS which considers the positional relationship between water sources and sub-regions as well as SrRI, and the criteria for determining key supervision sub-regions. Favorable effects are achieved by applying this methodological system in determining water source perimeter sub-regions distributed along the Yangtze’s Nanjing section. Results revealed that for water sources, the key sub-regions needing supervision were SD16, SD06, SD21, SD26, SD15, SD03, SD02, SD32, SD10, SD11, SD14, SD05, SD27, etc., in the order of criticality. The sub-region with the greatest risk threats on the water sources was SD16, which was located in the middle reaches of Yangtze River. In general, sub-regions along the upper Yangtze reaches had greater threats to water sources than the lower reach sub-regions other than SD26 and SD21. Upstream water sources were less subject to the threats of sub-regions than the downstream sources other than NJ09B and NJ03.

The Macroseismic Intensity Distribution of the 30 October 2016 Earthquake in Central Italy (Mw 6.6): Seismotectonic Implications

Science.gov (United States)

Galli, Paolo; Castenetto, Sergio; Peronace, Edoardo

2017-10-01

The central Italy Apennines were rocket in 2016 by the strongest earthquakes of the past 35 years. Two main shocks (Mw 6.2 and Mw 6.6) between the end of August and October caused the death of almost 300 people, and the destruction of 50 villages and small towns scattered along 40 km in the hanging wall of the N165° striking Mount Vettore fault system, that is, the structure responsible for the earthquakes. The 24 August southern earthquake, besides causing all the casualties, razed to the ground the small medieval town of Amatrice and dozens of hamlets around it. The 30 October main shock crushed definitely all the villages of the whole epicentral area (up to 11 intensity degree), extending northward the level of destruction and inducing heavy damage even to the 30 km far Camerino town. The survey of the macroseismic effects started the same day of the first main shock and continued during the whole seismic sequence, even during and after the strong earthquakes at the end of October, allowing the definition of a detailed picture of the damage distribution, day by day. Here we present the results of the final survey in terms of Mercalli-Cancani-Sieberg intensity, which account for the cumulative effects of the whole 2016 sequence (465 intensity data points, besides 435 related to the 24 August and 54 to the 26 October events, respectively). The distribution of the highest intensity data points evidenced the lack of any possible overlap between the 2016 earthquakes and the strongest earthquakes of the region, making this sequence a unique case in the seismic history of Italy. In turn, the cross matching with published paleoseismic data provided some interesting insights concerning the seismogenic behavior of the Mount Vettore fault in comparison with other active normal faults of the region.

Fabrication of intense neutron sources for medical applications

International Nuclear Information System (INIS)

Boulogne, A.R.; Walker, V.W.

1975-01-01

Simulated sources containing 252 Cf equivalents of 0.1 to 1.0 milligrams were prepared. Samarium was used as the simulant in a modified chemical plating technique similar to that used to prepare palladium-californium oxide cermet for industrial applications. The length of the platinum-10 percent iridium doubly encapsulated source with its protective sheath is 0.545 in. (14.1 mm). Outside dia of the source, including its sheath, is 0.109 in. (2.8 mm). Existing ''Brachytrons'' can accommodate this source form. This capsule system will withstand internal gas pressures from helium due to alpha decay and fission gases from a 1 mg 252 Cf source after ten years if the source is subjected to a maximum temperature of 800 0 C, the theoretical temperature of an accidental fire. Under these conditions the safety factor is 3. The capsule system is being tested with tracer amounts of 252 Cf to ensure that it will withstand adverse service conditions as well as tests specified for Special Form Materials. (auth)