CERN Document Server

The possibility of radio galaxies being random sample of otherwise normal elliptical galaxies is tested. Starting with the observed optical luminosity functions for elliptical galaxies, it is shown that the probability of an elliptical forming a radio source is a continuous, increasing function of optical luminosity, precisely proportional to square of the optical luminosity of the galaxy. Once the probability function is fixed, the luminosity function of normal elliptical galaxies is used as input for Monte Carlo simulations that reproduce the distribution of radio galaxies in the radio-optical luminosity plane. Our results show that radio galaxies are luminosity biased, but otherwise random sample of elliptical galaxies. This unified view of radio and non-radio ellipticals also explains the well ...

CERN Document Server

We test the hypothesis that radio galaxies are a random subset of otherwise normal elliptical galaxies. Starting with the observed optical luminosity functions for elliptical galaxies, we show that the probability of an elliptical forming a radio source is a continuous, increasing function of optical luminosity, proportional to L squared. With this probability function and the luminosity function of normal elliptical galaxies as input to Monte Carlo simulations, we reproduce the observed distribution of radio galaxies in the radio-optical luminosity plane. Our results show that radio galaxies are a luminosity-biased but otherwise random sample of elliptical galaxies. This unified view of radio-loud and radio-quiet ellipticals also explains the well known difference of ~0.5 mag in average optical ...

CERN Document Server

Using the Sloan Digital Sky Survey (SDSS) and the FIRST (Faint Images of the Radio Sky at Twenty Centimeters) catalogs, we examined the optical environments around double-lobed radio sources. Previous studies have shown that multi-component radio sources exhibiting some degree of bending between components are likely to be found in galaxy clusters. Often this radio emission is associated with a cD-type galaxy at the center of a cluster. We cross-correlated the SDSS with the FIRST catalog and measured the richness of the cluster environments surrounding both bent and straight multi-component sources. This led to the discovery and classification of a large number of galaxy clusters out to a redshift of z ~ 0.5. We divided our sample into smaller subgroups based on their optical and radio properties. We find that FR I ...

Energy Technology Data Exchange (ETDEWEB)

Radio interference and TV interference are being a problem in urban and rural areas. This interference is generated by high voltage transmission lines as well as distribution lines. The radio noise can be produced by polluted or damaged insulators, and by metal parts of the distribution lines. The corona effect on the surface of the dielectric material produces high frequency electromagnetic fields during the ionization and during the recombination period. Fields of different intensity are produced by positive voltage and negative voltage. The insulator flashover (leaking current) also produces electromagnetic fields. A new technique to measure these fields was developed. This technique measures the radiated fields on time domain and on frequency domain. This permits us to characterize the radiated field and thus identify the type of the source. Several measurements were done ...

CERN Document Server

2009 has been an extraordinary year for gamma-ray pulsar astronomy and 2010 promises to be equally good. Not only have we registered an extraordinary increase in the number of pulsars detected in gamma rays, but we have also witnessed the birth of new sub-families: first of all, the radio-quiet gamma pulsars and later an ever growing number of millisecond pulsars, a real surprise. We started with a sample of 7 gamma-ray emitting neutron stars (6 radio pulsars and Geminga) and now the Fermi-LAT harvest encompasses 24 "Geminga-like" new gamma-ray pulsars, a dozen millisecond pulsars and about thirty radio pulsars. Moreover, radio searches targeted to LAT unidentified sources yielded 18 new radio millisecond pulsars, several of which have been already detected also in gamma rays. Thus, currently the family of gamma-ray emitting neutron stars seems to be evenly ...

Energy Technology Data Exchange (ETDEWEB)

Two sources of negative ions are described. An rf source produces up to 14 ..mu..A beams of He/sup -/ by charge exchange in Rb vapor. The other Source of Negative Ions by Cesium Sputtering (SNICS) produces a wide variety of negative ion beams in the ..mu..A range. Two important features of SNICS are its simple, compact construction and its very good beam emittance (2 to 4..pi..mm mrad MeV/sup 1/2/). Both sources have lifetimes >200 hours and they are used extensively on the Wisconsin EN tandem.

CERN Document Server

We study luminosities of millisecond pulsars in globular clusters by fitting the observed luminosity distribution with single and double power laws. We use simulations to model the observed distribution as the brighter part of some parent distribution for Terzan 5 and try to find a model which simultaneously agrees with the observed diffuse radio flux, total predicted number of pulsars and observed luminosity distribution. We find that wide ranges of parameters for log-normal and power-law distributions give such good models. No clear difference between the luminosity distributions of millisecond pulsars in globular clusters and normal disk pulsars was seen.

CERN Document Server

Gamma-Ray Bursts (GRBs) are thought to originate at cosmological distances from the most powerful explosions in the Universe. If GRBs are not beamed then the distribution of their number as a function of gamma-ray flux implies that they occur once per (0.3-40) million years per bright galaxy and that they deposit >10^{53} ergs into their surrounding interstellar medium. The blast wave generated by a GRB explosion would be washed out by interstellar turbulence only after tens of millions of years when it finally slows down to a velocity of 10 km/s. This rather long lifetime implies that there could be up to several tens of active GRB remnants in each galaxy at any given time. For many years, radio observations have revealed the enigmatic presence of expanding neutral-hydrogen (HI) supershells of kpc radius in the Milky Way and in other nearby galaxies. The properties of some supershells cannot be easily explained in terms of conventional ...

CERN Document Server

We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the unresolved cores. The sample includes 16 quasars (11 core-dominated and 5 lobe-dominated) in the redshift range z=0.30--1.96, and one low-power radio-galaxy at z=0.064. No diffuse X-ray emission is present around the cores of the quasars, except for the nearby low-power galaxy that has diffuse emission on a scale and with a luminosity consistent with other FRIs. No high-amplitude, short-term variability is detected within the relatively short Chandra exposures. However, 1510-089 shows low-amplitude flux changes with a timescale of $\\sim$25 minutes. The X-ray spectra of the quasar cores are generally well described by a single power law model with Galactic ...

CERN Document Server

We present a Hubble Space Telescope image of the FRII radio galaxy 3C 401, obtained at 1.6 microns with the NICMOS camera in which we identify the infrared counterpart of the brightest region of the radio jet. The jet has a complex radio structure and brightens where bending occurs, most likely as a result of relativistic beaming. We analyze archival data in the radio, optical and X-ray bands and we derive its spectral energy distribution. Differently from all of the previously known optical extragalactic jets, the jet in 3C401 is not detected in the X-rays even in a long 48ksec X-ray Chandra exposure and the infrared emission dominates the overall SED. We propose that the dominant radiation mechanism of this jet is synchrotron. The low X-ray emission is then caused by two different effects: i) the lack of any strong external photon field and ii) the shape of the electron ...

International Nuclear Information System (INIS)

Active galactic nuclei (AGNs) and quasars (QSOs) appear to emit roughly equal energy per decade from radio to gamma-ray energies (e.g. Ramaty and Ligenfelter 1982). This argues strongly for a nonthermal radiation mechanism (see Rees 1984). In addition, statistical studies have indicated that the spectra of these objects in the IR-UV and 2 to 50 keV x-ray band, can be fitted very well with power laws of specific indices. These spectral indices do not seem to depend on the luminosity or morphology of the objects (Rothschild et al. 1983; Malkan 1984), and any theory should account for them in a basic and model independent way. If shocks accelerate relativistic protons via the first-order Fermi mechanism (e.g. Axfor 1981), the radiating electrons can be produced as secondaries throughout the source by proton-proton (p-p) collisions and pion decay, thus eliminating Compton losses (Protheroe and Kazanas 1983). As shown by Kazanas (1984), if ...

Energy Technology Data Exchange (ETDEWEB)

The chain of eddy current probes and a film cassette probe, which responds to radiation from a radio-active source in one of the heat exchanger pipes is examined. The probes are moved by nylon pipes on both ends of the chain through the pipe to be examined. The nylon pipes are bent off load. In this way the probes on the chain will adjust near to the plane of bending of the pipes to be tested.

Energy Technology Data Exchange (ETDEWEB)

The COBE data on cosmic background radiation (CBR) isotropy and spectrum are generally considered to be explicable only in the context of the Big Bang theory and to be confirmation of that theory. However, this data can also be explained by an alternative, non-Big Bang model which hypothesizes an intergalactic radio-absorbing and scattering medium. Dense, force-free magnetic filaments generated by quasars, active galactic nuclei and Herbig-Haro objects can remain stable in the intergalactic medium for many Gy. They will be opaque to radiation with wavelengths longer than 100--400 microns, and essentially transparent to shorter wavelengths. They are thus capable of thermalizing and isotropizing the cosmic background radiation, and of accounting for the observed decrease of radio luminosity of galaxies within increasing distance from earth. A simple, inhomogeneous model of such an absorbing medium can reproduce both the isotropy and spectrum of ...

Energy Technology Data Exchange (ETDEWEB)

A general expression for the current-density distribution of a focused-ion beam (FIB) in the chromatic-aberration region is set up in the form of a definite integral. With the experimentally obtained ion-energy distribution of a liquid-metal ion source, its contribution to the FIB current-density distribution is estimated. Calculated results explain the wide-exponential tail of a FIB.

Science.gov (United States)

Atmospheric and ionospheric perturbations associated with the acoustic-gravity waves (AGW) with typical frequencies of a few hertz -millihertz are considered. These events may be caused by the influence from space and atmosphere as well as by oscillations of the Earth surface and other near-surface phenomena. The surface sources include long-period oscillations of the Earth's surface, earthquakes, explosions, thermal heating, seisches and tsunami waves. The wavelike phenomena manifest themself as travelling disturbances of air (in the atmosphere) and of electron density (in the ionosphere). Travelling ionospheric disturbances (TIDs) are well detected by radio physical methods. AGW generation by near-surface sources is modeled by the numerical solution of the equation of geophysical fluid dynamics for different sources in two-dimensional non-linear dissipative compressible atmosphere. The numerical ...

Energy Technology Data Exchange (ETDEWEB)

The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.

Energy Technology Data Exchange (ETDEWEB)

A versatile, high brightness, volume type, low power RF source, capable of producing positive ion beams with intensities as high as 1 mA from gaseous feed materials and microamperes of negative ion beams has been characterized. The source can also be operated as a plasma sputter negative ion source to generate up to 1 mA of a selected species. The performance of the source in the positive and negative volume modes of operation can be greatly enhanced by addition of a removable, water cooled filament assembly in place of the negative sputter probe. For examine, the material utilization efficiencies of gaseous feed species can be more than doubled, total current intensities increased up to 40%, molecular dissociation fractions increased by 20% and minimum operating pressures reduced by a factor of four when operated in the volume mode. These added electrons also favorably effect, as a consequence of lower ...

International Nuclear Information System (INIS)

Nitrogen ion implantation improves the wear resistance of Ti-6Al-4V alloys by forming a hard TiN superficial passivation layer. However, the thickness of the layer formed by traditional ion implantation is typically 100-200 nm and may not be adequate for many industrial applications. We propose to use radio-frequency (RF) plasma nitriding and nitrogen plasma immersion ion implantation (PIII) to increase the layer thickness. By using a newly designed inductively coupled RF plasma source and applying a series of negative high voltage pulses to the Ti-6Al-4V samples. RF plasma nitriding and nitrogen PIII can be achieved. Our process yields a substantially thicker modified layer exhibiting more superior wear resistance characteristics, as demonstrated by data from micro-hardness testing, pin-on-disc wear testing, scanning electron microscopy (SEM), as well as Auger electron spectroscopy (AES). The performance of our newly developed inductively ...

CERN Document Server

We have used the SINFONI integral field spectrograph to map the near-infrared K-band emission lines of molecular and ionised hydrogen in the central regions of two cool core galaxy clusters, Abell 2597 and Sersic 159-03. Gas is detected out to 20 kpc from the nuclei of the brightest cluster galaxies and found to be distributed in clumps and filaments around it. The ionised and molecular gas phases trace each other closely in extent and dynamical state. Both gas phases show signs of interaction with the active nucleus. Within the nuclear regions the kinetic luminosity of this gas is found to be somewhat smaller than the current radio luminosity. Outside the nuclear region the gas has a low velocity dispersion and shows smooth velocity gradients. There is no strong correlation between the intensity of the molecular and ionised gas emission and either the radio or X-ray emission. The molecular gas in Abell 2597 and Sersic ...

CERN Document Server

We discuss the advantages which the next generation interferometer SKA (the Square Kilometer Array) will bring for Very Long Baseline Interferometry (VLBI) at centimeter wavelengths. With a sensitivity to micro-Jy level flux density, a brightness temperature limit of about 10.000 K, and an expected dynamic range in future VLBI maps of better than 1.000.000, the impact of SKA on the research of compact extragalactic radio sources and their energetic jets will be very strong. We discuss some consequences, including a possible combination of SKA with future space VLBI missions.

International Nuclear Information System (INIS)

The document represents a guide for the external decontamination of persons accidentally radio contaminated due to the use, production or transport of radioactive materials. The general conditions, from the medical point of view, to be kept in mind, in the event of accidental overexposures as decontamination treatment and the handling of samples are detailed throughout report. The external contamination without injury in skin or with wound its considered. The distribution of measures and responsibilities for the therapy of the irradiated patients with radioactive materials are enumerated. The preparations of decontaminate solutions are detailed in this work. Moreover, forms for the reception, physical evaluation of the patient and external contamination are presented. (author)

Energy Technology Data Exchange (ETDEWEB)

The advent, in the near future, of compact X-ray sources like Thomson Back-Scattering (TBS) will allow the clinical application of advanced X-ray imaging techniques, such as phase contrast, with higher sensitivity and lower impact in terms of dose delivery. In this work, we theoretically investigated the possibility of using such sources for phase contrast imaging of micro-calcifications included in a breast tissue. In our study we analyzed the phase and amplitude distribution of the TBS source and we showed that this source can be used for phase contrast imaging since the source coherence at the sample position is sufficiently high for achieving good contrast and micrometer spatial resolution. Indeed the spatial coherence of a TBS source is closer to that of a synchrotron radiation source, and much better than that of a ...

International Nuclear Information System (INIS)

Most of all research reactors are immerged in the deep water pool to be a ultimate heat sink. At the neighbor of the reactor, some radio-active matters, such as Na-24, Ar-41, Mg-27, Al-28 and etc, may be generated by the neutron irradiation. Those radio-active isotopes may rise up to the pool water surface through the natural convection flow, which can make the radioactivity in the reactor hall rise high enough to concern about the health of people working in the reactor hall. When the irradiation test facilities are loaded or unloaded during a normal operation, the highly radio-activated primary coolant may flow out through the irradiation test holes on the top of the reactor. This also may be a main hazard source to make the working environment of the reactor hall bad. Making a hot water layer 1.5 ? 2.0 m thick at the top of reactor pool would be a good measure to resolve that problem. The hot water ...

CERN Document Server

Consider the set of source distributions within a fixed maximum relative entropy with respect to a given nominal distribution. Lossless source coding over this relative entropy ball can be approached in more than one way. A problem previously considered is finding a minimax average length source code. The minimizing players are the codeword lengths --- real numbers for arithmetic codes, integers for prefix codes --- while the maximizing players are the uncertain source distributions. Another traditional minimizing objective is the first one considered here, maximum (average) redundancy. This problem reduces to an extension of an exponential Huffman objective treated in the literature but heretofore without direct practical application. In addition to these, this paper examines the related problem of maximal minimax pointwise redundancy and ...

Energy Technology Data Exchange (ETDEWEB)

The PAH (polycyclic aromatic hydrocarbons) concentration in coastal zones in the Arctic were studied. Assessment in remote areas is difficult because PAHs contamination from fossil fuel discharges and combustion can be masked by PAHs from natural sources, such as oil seeps, bitumens and forest fires. It is believed that the most important source of anthropogenic PAHs in the Arctic is the long range transport of combustion emissions. A comparison study of PAH distribution between the Beaufort Sea and the Barents Sea led to the interpretation of PAH distributions in terms of potential sources and their geochemistry. PAH concentrations in the Barents Sea sediments were found to be 2 to 20 times lower than in the Beaufort Sea sediments; they are believed to be from anthropogenic sources. In the Beaufort Sea the sediments were found to have been derived from natural ...

International Nuclear Information System (INIS)

Rectum reference dose points have a direct impact on the morbidity seen in gynecological intracavitaty radiotherapy. The aim of this study is to obtain less morbidity by marking rectum with radio opaque solution. Fourteen patients with gynecological cancer who underwent external radiotherapy received 15 Gray (Gy) intracavitary radiotherapy. During the internal radiotherapy planning, radio opaque solution has been administered into the rectum to observe it on lateral radiogram. Thus rectum reference dose point and five points were marked at sites nearest to the sources. Nucletron Planning system was used for obtaining three-dimensional planning. After therapy patients were followed at every three months. Median follow-up was 18 months. Most frequently observed morbidities were grade 1-2 rectitis and cystitis in six patients. As a result, more accurate rectum dose values and less factors causing dose changing can provide ...

CERN Document Server

I present here a review of past and present multi-disciplinary research of the Pittsburgh Computational AstroStatistics (PiCA) group. This group is dedicated to developing fast and efficient statistical algorithms for analysing huge astronomical data sources. I begin with a short review of multi-resolutional kd-trees which are the building blocks for many of our algorithms. For example, quick range queries and fast n-point correlation functions. I will present new results from the use of Mixture Models (Connolly et al. 2000) in density estimation of multi-color data from the Sloan Digital Sky Survey (SDSS). Specifically, the selection of quasars and the automated identification of X-ray sources. I will also present a brief overview of the False Discovery Rate (FDR) procedure (Miller et al. 2001a) and show how it has been used in the detection of ``Baryon Wiggles'' in the local galaxy power spectrum and source identification ...

International Nuclear Information System (INIS)

Despite the widely recognized usefulness of the AAPM TG-43 brachytherapy dose calculation formalism, a straightforward application of this approach to describe the dose distribution about intravascular line sources as proposed by TG-60 may be difficult or even impossible, especially when these line sources emit low-energy photons or beta particles. The causes of these limitations are investigated and illustrated by means of some numerical examples. In order to solve the observed limitations an adapted formalism is proposed, intended specifically for the description of the dose rate distribution about line sources but conceptually similar to the TG-43/TG-60 formalism. Several examples are presented to illustrate the usefulness of the proposed line source dose calculation formalism.

International Nuclear Information System (INIS)

Liquid metal ion sources (LMISs) with Ga as ion species are widely used in focused ion beam (FIB) technology for micromachining and surface treatment on the sub-micron and nano-scale. Key features of a LMIS for investigating mechanical properties and 3D-microfabrication of materials are long life-time, high brightness, stable ion current and a highly effective milling ability for the material to be modified. In order to increase the material removal rate, heavier ions than Ga and their clusters should be applied. Bismuth (Bi) is the heaviest, non-radio-active element in the periodic table, is non-toxic and exhibits a low melting point. We have thus produced a long-life (about 1000 h) Bi LMIS with a good beam performance, applicable in any FIB system. Since Bi is the only element in this source, it is not necessary to separate it from other ions by a mass filter. Investigation of the sputtering rate of NiTi shape memory ...

Energy Technology Data Exchange (ETDEWEB)

A thermoluminescence (TL) sheet and its spatial readout system for in vivo measurement of spatial dose distribution around sources has been newly developed for intracavitary high dose-rate radiation therapy. The TL sheet (40 cm x 50 cm x 200 {mu}m), which is composed of teflon mixed with BaSO{sub 4} (Eu doped) powder, has a linear response with a very wide dynamic range from at least 0.002 cGy to 5000 cGy for {sup 60}Co sources. Phantom test of the TL sheet readout system demonstrated that absorbed dose with TL sheet and that with ionization chamber as standard dosimeter agreed well. For clinical application, TL sheet was attached on an applicator of intracavitary radiation therapy for rectal cancer. After irradiation with high dose-rate {sup 60}Co sources, the in vivo dose distribution on the surface of the rectum was determined. The TL sheet was suggested to provide a convenient ...

Science.gov (United States)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.

British Library Electronic Table of Contents (United Kingdom)

Purpose - The objective of this study is to examine the effects of pan-frying, boiling and cooking in a microwave on the amount of L-carnitine in meat and to look at its distribution in the surrounding fluid after food processing. Design/methodology/approach - Total carnitine, free carnitine and acylcarnitines were determined in meat samples from beef, pork and poultry (including ostrich) and in a liver sample from beef. The measurements were carried out before and after the specimens were subjected to different heat treatments. A radio-enzymatic assay was used for measurement of L-carnitine. Results are expressed per 100 gram dry matter and per 100 gram wet weight. Findings - Except for pan-frying, virtually no losses of carnitine occurred during the different procedures of heat treatment...

Science.gov (United States)

Sources of manganese are identified. Uptake and distribution of manganese in plants and man are discussed, and the role of manganese in metabolism is described. The epidemiology of manganese toxicity is outlined, permissible air concentrations are listed, and the symptoms of manganese toxicity and deficiency are described. 555 references, 32 tables.

Science.gov (United States)

... 2010-10-01 2010-10-01 false Battery installations. 120.354 Section 120...Sources and Distribution Systems § 120.354 Battery installations. (a) Large batteries. Each large battery installation...

International Nuclear Information System (INIS)

This work improves the reliability and accuracy in the reconstruction of the total isotope activity content in heterogeneous nuclear waste drums containing point sources. The method is based on #chi#"2-fits of the angular dependent count rate distribution measured during a drum rotation in segmented gamma scanning. A new description of the analytical calculation of the angular count rate distribution is introduced based on a more precise model of the collimated detector. The new description is validated and compared to the old description using MCNP5 simulations of angular dependent count rate distributions of Co-60 and Cs-137 point sources. It is shown that the new model describes the angular dependent count rate distribution significantly more accurate compared to the old model. Hence, the reconstruction of the activity is more accurate and the errors are ...

Energy Technology Data Exchange (ETDEWEB)

High-brightness negative ion beams, especially O{sup -} beams, from a compact gaseous plasma source are studied to evaluate the suitability for high-resolution SIMS. Ion-optical calculations are made using the beam parameters from the new source. Results suggest that sub-100 nm spot with O{sup -} beam current of 10 pA is achievable. Beam focusing, the resulting beam current distributions at the target and the expected instrumental performance are discussed.

International Nuclear Information System (INIS)

A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are ...

International Nuclear Information System (INIS)

A semi-mechanistic model for calculating solid radionuclide release rates from bubbling pools of sodium was developed. The influence of particle spacial and size distributions on the decontamination of the releases was analysed and found significant. Decontamination factors are shown as a function of pool depth, bubbling characteristics and particle size distribution. The calculation of a decontamination factor for estimating the source term of large scale hypothetical core disruptive accidents is presented. The decontamination factor for a large scale accident was found to be two orders of magnitude greater than results obtained from small scale experiments conducted with uniform particle distributions. (orig.).

CERN Document Server

Suppose an astronomer is equipped with a device capable of detecting emissions -- whether they be electromagnetic, gravitational, or neutrino -- from transient sources distributed throughout the cosmos. Because of source rate density evolution and variation of cosmological volume elements, the sources first detected when the machine is switched on are likely to be ones in the high-redshift universe; as observation time increases, rarer, more local, events will be found. We characterize the observer's evolving record of events in terms of a "probability event horizon", converging on the observer from great distances at enormous speed, and illustrate it by simulating neutron star birth events distributed throughout the cosmos. As an initial application of the concept, we determine the approach of this horizon for gamma-ray bursts (GRBs) by fitting to redshift data. The event rates ...

Energy Technology Data Exchange (ETDEWEB)

The 3-D model program was developed to apply a mise-a-la-masse method to linear current sources with optional shapes. Mise-a-la-masse method is a bipolar mapping survey method using current sources installed in wells, and recently has been widely used for direct exploration of geothermal reservoirs. This method is also used for monitoring underground fluid as electrode arrangement of fluid flow tomography for surveying underground fluid (geothermal fluid, underground water, petroleum). In the geothermal reservoir exploration, the casing pipes of wells are used as linear current sources, and measured data are processed as those based on vertical current source. In the largely inclined well, the inclination of current sources should be considered. The 3-D modeling program was developed by difference calculus using the theoretical potential equation and apparent resistivity based on ...

UK PubMed Central (United Kingdom)

BackgroundThe aim of this double-blind randomized study is to test the efficacy of a radio electric stimulator device using an auricular reflex therapy protocol for stress-related...Full Text Available

CERN Document Server

The disk around AB Aur was imaged and resolved at 24.6\\,$\\mu$m using the Cooled Mid-Infrared Camera and Spectrometer on the 8.2m Subaru Telescope. The gaussian full-width at half-maximum of the source size is estimated to be 90 $\\pm$ 6 AU, indicating that the disk extends further out at 24.6\\,$\\mu$m than at shorter wavelengths. In order to interpret the extended 24.6\\,$\\mu$m image, we consider a disk with a reduced surface density within a boundary radius $R_c$, which is motivated by radio observations that suggest a reduced inner region within about 100 AU from the star. Introducing the surface density reduction factor $f_c$ for the inner disk, we determine that the best match with the observed radial intensity profile at 24.6\\,$\\mu$m is achieved with $R_c$=88 AU and $f_c$=0.01. We suggest that the extended emission at 24.6\\,$\\mu$m is due to the enhanced emission from a wall-like structure at the boundary radius (the inner edge of ...

CERN Document Server

The non-thermal supernova remnant RX J1713.7-3946 (G347.3-0.5) has recently been shown to be a site of cosmic ray (CR) electron acceleration to TeV energies (Muraishi et al. 2000). Here we present evidence that this remnant is also accelerating CR nuclei. Such nuclei can interact with ambient interstellar gas to produce high energy gamma-rays via the decay of neutral pions. We associate the unidentified EGRET GeV gamma- ray source 3EG J1714-3857 with a massive (~3*10 5 Mo) and dense (~500 nucleons cm -3) molecular cloud interacting with RX J1713.7-3946. Direct evidence for such interaction is provided by observations of the lowest two rotational transitions of CO in the cloud; as in other clear cases of interaction, the CO(J=2-1)/CO(J=1-0) ratio is significantly enhanced. Since the cloud is of low radio and X-ray brightness, CR electrons cannot be responsible for the bulk of its GeV emission there. A picture thus emerges where both electrons ...

Energy Technology Data Exchange (ETDEWEB)

The Green-Chasman lattice, which is the basis for both NSLS storage rings, was conceived with insertion devices in mind. Long, field-free straight sections were provided in the design. The electron optics were chosen so that these sections had zero dispersion and the effects of new magnetic structures placed in these regions would have minimal effect on the emittance of the electron beam. This design concept has been followed by all high-brightness rings which were built subsequent to the NSLS. The X-Ray Ring straight sections also have a very small vertical {beta} function, in addition to the zero dispersion. This was done to optimize the brightness of wiggler sources. There is a further benefit however. The {beta} function determines the beam size and divergence at a particular point in the storage ring lattice. The size is proportional to {radical}{beta} and the divergence is proportional to 1/{radical}{beta}. Thus the electron beam is very small at the center ...

International Nuclear Information System (INIS)

The macrotemporal structure of the Super-ACO Storage ring free-electron laser (FEL) can be either continuous, pulsed, or chaotic, and can present some rapid fluctuations. The temporal evolution of a storage ring FEL involves both the longitudinal motion of the positron beam (especially the synchrotron oscillations) and the FEL dynamics, as in a coupled system. Studies on the dynamics of the positron beam are performed here, in the goal to have a stable source for FEL applications, and to determine the conditions for a stable Q-switching experiment. The employed method is to study the influence of a controlled change of the radio frequency (RF) (modulation or frequency jump) on the beam. A simple theoretical model taking into account the perturbed RF system is presented to help the understanding of the experimental data. The different methods of measurement are described. Then, the results are given for several experimental conditions and the ...

Science.gov (United States)

The GRO observation (Hartman et al., 1992) of a very strong flux of gamma rays with an energy index

CERN Document Server

We introduce a methodology for analysis of multiwavelength data from X-ray selected BL Lac (XBL) objects detected in the TeV regime. By assuming that the radio--through--X-ray flux from XBLs is nonthermal synchrotron radiation emitted by isotropically-distributed electrons in the randomly oriented magnetic field of a relativistic blazar jet, we obtain the electron spectrum. This spectrum is then used to deduce the synchrotron self-Compton (SSC) spectrum as a function of the Doppler factor, magnetic field, and variability timescale. The variability timescale is used to infer the comoving blob radius from light travel-time arguments, leaving only two parameters. With this approach, we accurately simulate the synchrotron and SSC spectrum of flaring XBLs in the Thomson through Klein-Nishina regimes. Photoabsorption by interactions with internal jet radiation and the intergalactic background light (IBL) is included. Doppler factors, magnetic fields, ...

Energy Technology Data Exchange (ETDEWEB)

The power source facilities of JT-60 consist of poloidal magnetic coil power source, toroidal magnetic coil power source, the power generation facility for heating, operation power distribution facility and secondary cooling facility, and at the time of the experiment operation of JT-60, they supply 1300 MVA of instantaneous maximum power to loads. The component machinery and equipment of the power source facilities are installed in about 20 indoor and outdoor places, and their mounted parts are about 15,000 kinds. About 3,000 kinds of spare parts are preserved in 15 exclusively used stores. The managing system for mounted parts and spare parts of JT-60 power source facilities which possesses the functions of rapidly and efficiently carrying out the storage of large quantity of information, mutual relating and retrieval by making mounted parts and spare parts ...

International Nuclear Information System (INIS)

We present a development of the use of the AAPM TG-43 dose formalism applied to "1"3"7Cs gynecological implant sources. The geometry factor, radial dose function, and anisotropy function of a "1"3"7Cs source modeled after the Nuclear Associates 67-809 series stainless steel jacketed tube source were derived following the AAPM TG-43 formalism. The dose rate distribution through the center of the source using the AAPM TG-43 dose formalism is calculated and compared with the calculations obtained using the Sievert summation and Monte Carlo simulation. The three methods resulted in an agreement within less than 5%, or an isodose rate line agreement within 2 mm. We demonstrate that the AAPM TG-43 formalism can be applied to "1"3"7Cs linear sources and is capable of serving as a "1"3"7Cs dose calculation algorithm that can be used for treatment planning purpose.

International Nuclear Information System (INIS)

A case report of falsely elevated serum hormone values measured by radio-immunoassay (RIA) is described. The radio-immunoassays concerned have a first antibody raised in rabbits and mostly a separation technique based on a second antibody-solid phase system. The presence of heterophyle (anti-rabbit) antibodies in patients' serum is proved.

International Nuclear Information System (INIS)

The energy distribution of ion beams is important especially for low energy ion beam applications. The energy distributions of negative-ion beams produced through secondary ion emission by sputtering were measured and compared with theoretically estimated distributions by use of four different negative-ion production probability equations (modified surface ionization model, exponential velocity dependence model, and our modified exponential velocity dependence models (modified decaying factor model and combination model of velocity dependence and surface ionization)). In the measurements, the energy distributions of C"- and Ag"- beams had a peak at a few to several eV and the full width at half maximum were 15 eV and 11 eV, respectively. These results could be well explained by the estimated distributions by virtue of our combination model or the modified surface ionization model. ...

CERN Document Server

We present a detailed spectral analysis of point-like X-ray sources in the XMM-COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10 keV energy band and have been identified through optical spectroscopy. The majority of the sources are well described by a simple power-law model with either no absorption (76%) or a significant intrinsic, absorbing column (20%).As expected, the distribution of intrinsic absorbing column densities is markedly different between AGN with or without broad optical emission lines. We find within our sample four Type-2 QSOs candidates (L_X > 10^44 erg/s, N_H > 10^22 cm^-2), with a spectral energy distribution well reproduced by a composite Seyfert-2 spectrum, that demonstrates the strength of the wide field XMM/COSMOS survey to detect these rare and underrepresented sources.

International Nuclear Information System (INIS)

The term Smith-Purcell free electron laser can be employed generally to describe any coherent radiation source in which a diffraction grating is used to couple an electron beam with the electromagnetic field. To date, most practical developments of this concept have focused on devices which operate in the millimeter spectral regime. In this paper construction of a Smith-Purcell free-electron laser operating in the far-infrared (FIR) region using a novel resonator cavity design and the electron beam from a low energy (0.5-5 MeV) radio-frequency accelerator will be discussed. A tunable source in this region would have many applications and since the beam energy is low, the small size and low overall cost of such a device would make it a laboratory instrument. Current projects which are progressing towards developing a FIR source are the programs at Stanford and CREOL. Both of these projects are using ...

Energy Technology Data Exchange (ETDEWEB)

Presently, most charge state distributions produced with highly charged ion sources are predicted with models that approximate the ionization process with the Lotz formula. The Lotz ionization cross sections decrease approximately geometrically with increasing charge state except for ions with very few vacancies, for ions with very few electrons, and for electron impact energies which barely exceed the ionization energy. The geometrical decrease causes these models to predict a maximum abundance for most of the charge states, which is only weakly dependent on the charge state. Experimental results, however, yield much higher abundances for ions with an empty M shell than ions with a partly filled M shell. This difference is explained with indirect ionization processes that are neglected by the Lotz approximation, and normally can be neglected for the ionization of the L shell, but can dominate the ionization of the M shell. (c) 2000 American ...

Energy Technology Data Exchange (ETDEWEB)

Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions ...

International Nuclear Information System (INIS)

Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions ...

Energy Technology Data Exchange (ETDEWEB)

Measurements of neutron and gamma-ray penetrations in an iron shield were performed up to a 60-cm depth in a tightly coupled source shield configuration with the fast-neutron reactor YAYOI as a source. Rates of neutron reactions and gamma-ray dose rates in the iron shield were obtained using activation foils and thermoluminescent dosimeters. Analyses of the experiments were made by using the DOT-III code with coupled neutron and gamma-ray cross sections from ENDF/B-IV and POPOP4 libraries. To obtain the source condition for the iron shield analyses, the calculated spectrum was adjusted to the measured reaction rates at the reactor shield boundary. The calculated neutron and gamma-ray distributions in the iron shield show fairly good agreement with the experiments. The effect of difference in Bondarenko-type self-shielding factors on the analyses of the iron shield is also shown.

British Library Electronic Table of Contents (United Kingdom)

Objective:EEG source imaging provides important information regarding the underlying neural activity from noninvasive electrophysiological measurements. The aim of the present study was to evaluate source reconstruction techniques by means of the intracranial electrocorticograms (ECoGs) and functional MRI.Methods:Five source imaging algorithms, including the minimum norm least square (MNLS), LORETA with Lp-norm (p equal to 1, 1.5 and 2), sLORETA, the minimum Lp-norm (p equal to 1 and 1.5; when p=2, the MNLS method is mathematically equivalent to the minimum Lp-norm) and L1-norm (the linear programming) methods, were evaluated in a group of 10 human subjects, in a paradigm with somatosensory stimulation. Cortical current density (CCD) distributions were estimated from the scalp somatosensor...

International Nuclear Information System (INIS)

Ionizing radiations that differ in number, size, and distribution of energy deposition events might be expected to cause different effects for the same absorbed dose. Furthermore, microdosimetry calculations suggest that large variations in biological effectiveness might be expected for internally deposited alpha-emitting radionuclides for the same absorbed dose, depending upon the specific activity and spatial distribution of the sources in tissue. The study described in this article was designed to demonstrate these phenomena in vitro. Cultured Chinese hamster ovary (CHO-K1 BH4) cells were exposed in vitro to inert, insoluble ceramic microspheres in zirconium dioxide labeled with "2"3"9Pu. The average exit energy of the 5.15 MeV alpha particle was calculated to be 4.3 MeV. Exposure times varied from four to seven hours to achieve the desired dose level.

Energy Technology Data Exchange (ETDEWEB)

The detection efficiency of gamma scanning system in irradiated materials examination facility has been measured. Gamma-ray sources used in this experiment are Cs-Co standard sources a PWR spent fuel rod in which {sup 134}Cs and {sup 154}Eu peaks are clearly identified in the energy region of 500 to 1,600 keV. The distance between source and detector is about 1.6 m. A slit type collimator with 3 mm-width window and 30 mm-thick lead block are installed between source and detector. The detector is a HPGe detector. This equipment is mainly used in gamma scanning of irradiated nuclear fuel. The measured detection efficiency seems to be 1.89 x 10{sup -6} % for 1 MeV gamma-ray. With these results the activities of unknown sources could be measured. This results are expected to be used in the measurement of the absolute distribution of gamma emitting nuclides in ...

International Nuclear Information System (INIS)

The time-dependent probability distribution of neutrons, precursors and detectrons in a space-independent, low-power, multiplying assembly with a source is developed in the multigroup approximation as forward and backward Kolmogorov equations. The relationship between these as adjoint equations is made explicit in a tensor notation and the equations developed in the generating-function formalism. (author).

Energy Technology Data Exchange (ETDEWEB)

The importance of cellular dosimetry in both diagnostic and therapeutic nuclear medicine is becoming increasingly recognized. Experimental range-energy relations for electrons and alpha particles, along with derived geometric reduction factors, are used to calculate cellular absorbed fractions for these radiations. The resulting absorbed fractions are employed to calculate cellular S-values for several radionuclides. Cellular absorbed fractions for monoenergetic electron sources with energies ranging from 0.1 keV to 1 MeV, distributed uniformly in the source region, are calculated for several target {l_arrow} source combinations including cell{l_arrow}cell, cell{l_arrow}cell surface, nucleus{l_arrow}nucleus, nucleus {l_arrow}cytoplasm and nucleus {l_arrow}cell surface. Similar data are also provided for monoenergetic alpha particle sources with energies ranging from 3 to 10 MeV. ...

Energy Technology Data Exchange (ETDEWEB)

A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder positioned so that its central axis is ...

Energy Technology Data Exchange (ETDEWEB)

Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region (l {element_of} [65{sup o}, 85{sup o}]). For the ...

International Nuclear Information System (INIS)

The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with #approx#1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (#approx#0.6 M_s_u_n) and MM1b (#approx#1.4 M_s_u_n), located near the radio continuum sources VLA 2/VLA 3 and VLA 1, respectively. Within MM1b, two gas clumps were found to be expanding away from VLA 1 at about #+-#3 km s"-"1, as a result of the most recent star formation activity in the region. Observed molecular lines show emission peaks at two positions, MM1a and MM1b: sulfur-bearing species have emission peaks toward MM1a, but methanol and saturated species at MM1b. We identified high-temperature (#approx#200 K) gas toward MM1a and the hot core in MM1b. This segregation may result from the evolution of the massive star-forming core. In the very early ...

International Nuclear Information System (INIS)

Electron cyclotron resonance heating (ECH) in BPX is planned as a possible upgrade to supplement the baseline ion cyclotron resonance frequency (ICRF) system. Eventual implementation primarily depends on the development of the required source technology. ECH offers important technical advantages over ICRF: High radio-frequency (FR) power density can be transmitted through ports (P/A >#approx# 100 MW/M"2), and the antenna need not be in contact with the plasma for efficient coupling. In particular, low-field side, linearly polarized (O-mode) power injection will suffice. By controlling the N spectrum, or by steering the antenna, the power deposition profile can be controlled during ramping of the magnetic field even with a fixed frequency source. Because of the possibility of localized power deposition, ECH is a natural candidate for controlling magnetrohydrodynamic (MHD) activity. Sawtooth oscillations may be prevented ...

Energy Technology Data Exchange (ETDEWEB)

Wasaga Distribution Inc. is located on Georgian Bay in one of the fastest growing communities in Ontario. It has a customer base of 10,400 residential customers in a service territory of 61 square kilometres. This presentation outlined Wasaga's experience with the Itron fixed network 2.0 RF Centron IDM meter. It outlined the dataflow features and capabilities of the meter in terms electricity endpoints, repeaters, and neighbourhood collectors. The repeater is designed to capture ERT IDM reads and retransmit at a higher power. The meter is also designed to reduce the number of cell control units (CCU) necessary to cover an area. The meter sleeve design allows for simple and cost effective installation, and has a bandwidth capable of over 3000 reads per second. The Itron CCU4 is a listening receiver that captures ERT reads and transmits the data to the utilities. It has a battery back up that lasts 4 hours in case of a power outage. It can be mounted on a ...

CERN Document Server

We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six VLA/EVLA (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; This builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L_radio proportional to L_X-ray ^(-0.72+/-0.04) . Current research linking the mass of supermassive black holes and stellar-mass black holes in the "low/hard" state to X-ray luminosities and radio luminosities suggest a "fundamental plane of accretion onto black holes" that has a positive correlation of L_radio proportional to L_X-ray^(0.67+/-0.12) . Our simultaneous results differ from this ...

Energy Technology Data Exchange (ETDEWEB)

This paper discussed issues related to the storage of electricity produced from renewable energy sources. Storage systems currently used by distribution systems were reviewed. The study showed that successful storage systems ensure high charging and discharging rates for shorter periods of time. Systems with high storage capacities must also be able to store energy for longer periods of time than traditional energy storage systems. Systems include pumped storage plants; electro-chemical accumulators; compressed air accumulators; and redox flow batteries. Hydrogen technologies for the storage of electric energy from renewable sources were reviewed. The paper also outlined energy storage and fuel cell research currently being conducted by researchers in the Czech Republic. The study concluded by stating that new energy storage technologies are required to ensure the reliability of electricity produced from renewable energy ...

Energy Technology Data Exchange (ETDEWEB)

This technical report describes an outline, features, total energy efficiency, and specifications of binary heat pump system. A closed circuit distributed water heat source heat pump method is employed in the binary heat pump system. Since the circulating water, which is adjusted at a constant temperature, is used as the heat source of the indoor unit, a stable performance can be obtained regardless of outside atmospheric temperature. The binary heat pump system is mainly composed of a center heat pump unit, indoor heat pump unit, heat source water pipes, and circulating pump. The center heat pump unit and the indoor heat pump unit are connected with each other by the heat source water, and each unit can be operated independently. This system is characterized by the simultaneous operation of cooling and heating, high efficiency, high energy saving, high reliability of system, ...

Energy Technology Data Exchange (ETDEWEB)

Contents include: index for 1970-1980; January 1981 data -- alert periods, daily solar indices, solar flares, solar radio emission, coronal holes, inferred interplanetary magnetic field polarities, mean solar magnetic field, spacecraft observations, December 1980 data -- daily solar-activity centers, sudden ionospheric disturbances, spacecraft observations, solar radio emission, cosmic rays, geomagnetic indices, radio-propagation indices; late data -- solar radio emission November, December 1980, spacecraft observations November 1980, cosmic rays, Huancayo Oct 1980 -- climax, alert, Deep River Nov 1980.

Science.gov (United States)

... of electronic systems (satellite terminals, radio and ... helps organizations investigate the stochastic nature of ... cycle time, maximum queue lengths, and ...

Science.gov (United States)

Briefly, 48 MOS microparticle sensors (essentially the same as those flown on .... at the Naval Research Lab to interpret the polarization of the incoming radio .... Adapter Satellite, to be published in Journal of Spacecraft and Rockets, 1994. ...

Science.gov (United States)

... For communication systems that employ spatial audio technology to separate intercom and/or radio channels, configurations of the spatial ...

International Nuclear Information System (INIS)

Full text: Research reactors have been playing a multi dimensional role in areas of nuclear fuel cycle programme, radio-isotope productions, neutron beam research etc. To ensure an efficient, smooth and safe operation of a nuclear research reactor, many reactor physics evaluations are required on routine basis. As part of reactor core management the important activities are maintaining core reactivity status, core power distribution, xenon estimations, safety evaluation of in-pile irradiation samples and experimental assemblies and assessment of nuclear safety in fuel handling/storage. In-pile irradiation requires a prior estimation of the reactivity load due to the sample, heating rate and the activity developed in it during irradiation. For the safety of the personnel handling irradiated samples the dose rate at the surface of shielded flask housing the irradiated sample should be less than 200 mR/Hr. Therefore, a proper shielding and ...

Science.gov (United States)

Self-amplifying spontaneous radiation free-electron lasers, such as the LCLS or the European X-FEL, rely on the incoherent, spontaneous radiation as the seed for the amplifying process. Though this method overcomes the need for an external seed source one drawback is the incoherence of the effective seed signal. The FEL process allows for a natural growth of the coherence because the radiation phase information is spread out within the bunch due to slippage and diffraction of the radiation field. However, at short wavelengths this spreading is not sufficient to achieve complete coherence. In this presentation we report on the results of numerical simulations of the LCLS X-ray FEL. From the obtained radiation field distribution the coherence properties are extracted to help to characterize the FEL as a light source.

British Library Electronic Table of Contents (United Kingdom)

LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at 13Hz providing a 500MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000MW by continuously varying the 6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in th...

Energy Technology Data Exchange (ETDEWEB)

A complete code based on the finite element method (FEM) is used to study the attenuation of gamma rays, of source energy 9 MeV, in simple homogeneous lead and water systems. The results are compared, in tables and graphs, with those produced by a Monte Carlo method of solution. In the comparison, particular attention is paid to the annihilation gamma rays generated by the pair production process, to energy deposition, and to the leakage spectra. A model, multilayer, slab shield, having a fission neutron source impinging on the left-hand face, is also solved by the FEM code, using data from a coupled neutron/gamma ray cross section library. The resulting neutron and gamma ray flux distributions, and the leakage spectra, are shown graphically. (author).

Energy Technology Data Exchange (ETDEWEB)

The performance requirements of the Advanced Photon Source (APS) challenge the control system in a number of areas. This paper will review a few applications of advanced technology in the control and monitoring of the APS. The application of digital signal processors (DSPs) and techniques will be discussed, both from the perspective of a large distributed multiprocessor system and from that of embedded systems. In particular, two embedded applications will be highlighted, a beam position monitor processor and a DSP-based power supply controller. Fast data distribution is often a requirement. The application of a high-speed network based on reflective memory will also be discussed in the context of the APS global orbit feedback system. Timing systems provide opportunities to apply technologies such as high-speed logic and fiber optics. Examples of the use of these technologies will also be included. Finally, every modern ...

British Library Electronic Table of Contents (United Kingdom)

Many coastal areas have served as repositories of different anthropogenic and naturally induced organic material and nutrients. The major sources thereof are riverine inputs which strongly influence the spatial and temporal distribution of benthic communities. In this study, the benthic foraminiferal, meiofaunal, and macrofaunal colonies in front of three rivers in a poorly known, but environmentally valuable, area of the Central Adriatic Sea have been examined concurrently. The physico-chemical parameters of bottom water and sediment characteristics were determined in order to characterize both the sediment?water interface and the benthic environments. Although changes in the biota are neither univocal nor unidirectional, a moderate influence of riverine input on the different communities...

Energy Technology Data Exchange (ETDEWEB)

Neutron radiography systems are being used for real-time visualization of the dynamic behavior as well as time-averaged measurements of spatial vapor fraction distributions for two phase fluids. The data in the form of video images are typically recorded on videotape at 30 frames per second. Image analysis of he video pictures is used to extract time-dependent or time-averaged data. The determination of the average vapor fraction requires averaging of the logarithm of time-dependent intensity measurements of the neutron beam (gray scale distribution of the image) that passes through the fluid. This could be significantly different than averaging the intensity of the transmitted beam and then taking the logarithm of that term. This difference is termed the dynamic error (error in the time-averaged vapor fractions due to the inherent time-dependence of the measured data) and is separate from the static error (statistical sampling uncertainty). ...

Energy Technology Data Exchange (ETDEWEB)

This report contains the document control information and abstracts for Solar Energy Research Institute (SERI) Photovoltaic (PV) Program publications resulting from SERI's subcontracted PV research. The information is presented for reports published or distributed from August 1 through December 31, 1990. In the past, copies of the subcontractor reports were distributed to a broad spectrum of researchers in the field of photovoltaics at a considerable cost to the program. In an attempt to reduce costs and ensure that all researchers receive those current publications that are of specific interest to them, this report will outline these publications, organized by technology, on a regular basis. A list of additional publications and sources is included herein to provide the photovoltaic community with other sources of information. All of the documents represented here are available from the ...

CERN Document Server

Hot gas trapped in a dark matter halo will produce a decrement in the surface brightness of the microwave background, the Sunyaev-Zel'dovich (SZ) effect. While massive clusters produce the strongest central SZ decrements, we point out that a local galaxy halo, specifically the halo of M31, may be one of the brightest integrated SZ sources in the sky. For various realistic gas distributions consistent with current X-ray limits, we show that the integrated SZ decrement from M31 will be comparable to decrements already detected in more distant sources, provided its halo contains an appreciable quantity of hot gas. A measurement of this decrement would provide direct information on the mass, spatial distribution and thermodynamic state of hot gas in a low-mass halo, and could place important constraints on current models of galaxy formation. Detecting such an extended (~ 10 degree), low-amplitude signal ...

Wastenet

...Explore - The Lab - Australian Broadcasting Corporation's Gateway to Science Radio TV Shop News Sport Local Children Science Environment more Topics help Science Home News in Science Features Explore TV & Radio Dr Karl Play Podcasts DNA - The discovery of the double helix structure of DNA completely changed biology and opened up the new field of genetics. The 'backbone of life' has given us the human genome, stem cell research, ...

International Nuclear Information System (INIS)

The operation and proper handling of equipment for measuring EMR-300 electromagnetic waves are studied and apply that knowledge to determine which areas of the metropolitan area are mostly affected by exposure to the emission of radiation. This team is able to measure magnetic field strength, electric field strength and power density, also can measure the most important parameters in a simple manner. International standards provide maximum values for these parameters that limit human exposure to such radiation. These standards are based on epidemiological several and laboratory that have been carried out in order to determine in which circumstances a biological entity is exposed to a level of radiation that can cause harm to their health. It focuses on measuring the level of radiation in certain areas of interest, which were chosen because are areas with high population density and also in proximity to antennas that emit electromagnetic waves. Before carrying out the data collection ...

Science.gov (United States)

The phase space beam analyzer is a measurement instrument that is applied in laser technology to perform analyses of the spatial and angular distribution of rays. We are interested in this instrument as a means to characterize non-coherent light sources. In this context, a closer look at the tolerances of this optical instrument was considered useful. Having a so-called quadrupole lens as a key element, the phase space beam analyzer is a device that features anamorphic optical properties. To describe these anamorphic properties, recurrence was made to a description by extended ray-transfer matrices. This formalism allows for an analysis of the alignment tolerances of the phase space beam analyzer and facilitates a study of the sensitivities of the instrument. The analysis is complemented using numerical ray tracing.

International Nuclear Information System (INIS)

This article describes version 3.006 of Nuance, an advanced and freely available neutrino generator written by Dave Casper of University of California, Irvine. Source codes of the program are publicly available. This description is based on Dave Casper's article '' The Nuance Neutrino Physics Simulation and the Future '', http://nuint.ps.uci.edu/nuance/files/ nuancenuint01.pdf , Nuance website at http://nuint.ps.uci.edu/ nuance/ , README.txt file provided in the src folder of Nuance distribution, and my own experience as a Nuance user. (author)

International Nuclear Information System (INIS)

A possible novel application of hard x-ray emitted during laser-plasma interaction was discussed. The authors established an Optical Transform Function to study the joint effect of the spectral distribution and temporal profile of the laser-produced x-ray on x-ray phase imaging. Though the laser-produced x-ray pulse duration is short and incoherent, the analysis confirms that the current x-ray phase imaging theory still holds for laser-produced x-ray phase imaging

Energy Technology Data Exchange (ETDEWEB)

The Uinta Basin is an important hydrocarbon producing area, with extensive resources of hydrocarbon, bitumen, and fossil fuels. Gilsonite, tar sands, oil shale and coal are found in abundance with the cretaceous and Tertiary sedimentary rocks. The 25 papers include discussion on: leasing; thermal maturity of rocks and hydrocarbon deposits; influence of source rock type, thermal maturity and migration on composition and distribution of the natural gas; drilling; geology; structural evolution of gilsonite dykes; reclamation of coal mines; oil shale resources; and uranium mining.

British Library Electronic Table of Contents (United Kingdom)

The design and first results from a Double Sided Silicon Strip Detector (DSSSD) recently installed at the Lund Nuclear Microprobe facility (NMP) are presented. The detector has 64 sector strips and 32 ring strips, which in combination give more than 2000 detector cells, each with characteristics comparable with a standard surface barrier detector (SBD). The detector has been tested both with radioactive sources and with different ion beams and energies. The most striking features are the high rate virtually pile-up free operation and also the possibility of detailed measurement of angular distributions.

Energy Technology Data Exchange (ETDEWEB)

The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, a longitudinal feedback system is required together with other diagnostics. In this paper, we study the possibility of using Coherent Synchrotron Radiation (CSR) from the chicane as a diagnostic tool for bunch length feedback. Studies show that CSR is a good candidate, even for a non-Gaussian, double-horn longitudinal charge distribution as in the LCLS. We further check the possibility for detecting possible microbunching.

CERN Document Server

Process algebra for parallel and distributed processing

Energy Technology Data Exchange (ETDEWEB)

We reported the radio-protective effect of DTT. The treatment of DTT increased cell survival after gamma-irradiation, decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after UV-C irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. About 100 medicinal plants were purchased and methanol extract samples were prepared. Radio-protective and radio-sensitizing activities of these samples were screened. Seven samples showed above 20% radio-protective activities: Salvia miltiorrhiza, Areca catechu, Cornus officinalis, Alpiniae officinari rhizoma, Meliae fructus, Alpiniae katsumadaii semen, Betulae cortex. Acanthopanax sessiliflous showed the highest radio-sensitizing effect and 10 other samples revealed moderate ...

International Nuclear Information System (INIS)

Radio frequency (RF) sheaths are suspected of limiting the performance of present-day ion cyclotron range of frequencies (ICRFs) antennas over long pulses and should be minimized in future fusion devices. Within the simplest models, RF-sheath effects are quantified by the integral VRF = ? E|| ? dl where the parallel RF field E|| is linked with the slow wave. On 'long open field lines' with large toroidal extension on both sides of the antenna it was shown that VRF is excited by parallel RF currents j|| flowing on the antenna structure. In this paper, the validity of this simple sheath theory is tested experimentally on the Tore Supra (TS) ITER-like antenna prototype (ILP), together with antenna simulation and post-processing codes developed to compute VRF. The predicted poloidal localization of high-|VRF| zones is confronted to that inferred from experimental data analysis. Surface temperature distribution on ILP front face, as well as ...

Energy Technology Data Exchange (ETDEWEB)

Analytical expressions that describe the dependence of slopes and amplitudes of the scatter distribution functions (SDF) on source depth and media density are used to estimate a scatter component in SPECT projection data. Since the ratio of detected scattered to total photons (S/T), SDF amplitude and slope depend strongly on line source length (SL) used to obtain SDFs, we compared estimated scattered components using SDFs, obtained for lengths of 2-21 cm. At 10 cm source depth, S/T changes from 0.19 to 0.36 when SL changes from 2 to 21 cm. Scatter amplitude`s dependence on source depth (d) in water was described by 6.38e{sup -0.186d} for a 2 cm and 16.15e{sup -0.129d} for a 21 cm SL. Slope was described by 0.292d{sup -0.601} for a cm SL and by 0.396d{sup -0.82} for a 21 cm SL. The estimated scatter components are compared with simulated SPECT projection data obtained with Monte ...

DEFF Research Database (Denmark)

The sources of non-white noise in Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) are many. Familiar sources include low-frequency drift due to hardware imperfections, oscillatory noise due to respiration and cardiac pulsation and residual movement artefacts not accounted for by rigid body registration. These contributions give rise to temporal autocorrelation in the residuals of the fMRI signal and invalidate the statistical analysis as the errors are no longer independent. The low-frequency drift is often removed by high-pass filtering, and other effects are typically modelled as an autoregressive (AR) process. In this paper, we propose an alternative approach: Nuisance Variable Regression (NVR). By inclusion of confounding effects in a general linear model (GLM), we first confirm that the spatial distribution of the various fMRI noise sources is similar to what ...

International Nuclear Information System (INIS)

Enhanced nutrient cycling basically involves close interaction between inorganic and organic sources of nutrients. Contrasting scenarios of nutrient cycling are found under intensive cropping production systems in most industrialized countries and traditional production systems predominant in many developing countries, where there is a net mining of soil nutrients due to crop harvest removal and erosion. Therefore, to enhance nutrient management in marginal tropical soils it is necessary to maximize the efficiency of nutrient uptake from various inorganic and organic sources with minimal environmental impact. It is postulated that one of the main approaches will be the identification and/or selection of plant genotypes for enhanced nutrient acquisition, in particular at low levels of soil available nutrients. In this context, use of various isotope techniques in examining root activity/distribution pattern and plant ...

Energy Technology Data Exchange (ETDEWEB)

This work describes the use of volatile halocarbons in a pulp mill effluent, including chloroform, bromodichloromethane, and tri- and tetrachloroethylene, as tracers for the distribution and movements of effluent currents in a receiving water bay (Jackfish Bay) on the northern shore of Lake Superior. The results indicate the simplicity and usefulness of the technique and the significantly improved resolution of effluent plume delineation over the customary use of conductance profiles. Concentration patterns of the effluent volatiles suggest counterclockwise circulation of bay water that mixes with inflowing lake water at the eastern reach of the outer bay. The distribution of volatile contaminants is governed by the thermal regime of the receiving waters. During the summer months, the effluent plume wedges between the thermocline and epilimnion, mixing into the surface waters as the distance from the input source increases. ...

Science.gov (United States)

Target vessel materials used in spallation neutron source will be exposed to proton and neutron irradiation and mercury immersion environments. In order to evaluate the surface degradation of the vessel candidate materials due to such environment, the triple-ion beam irradiation taking the spallation reaction into account and mercury immersion tests were carried out. Mechanical properties of the gradient surface layer were evaluated by the inverse analysis with multi-layer model that considers distribution of surface characteristic was applied to the load and depth curves measured by using the instrumented indentation machine. Transmission electron microscopic observations were performed to evaluate the changes of microstructure in irradiated surface layer using focused ion-beam cut micro-specimen. The mechanical properties distributions in the surface layer were evaluated quantitatively and the changes in microstructures ...

International Nuclear Information System (INIS)

This report summarizes the results and activities funded by this three-year award. The principal goal of this project was to determine the thermal conductivity in clusters of galaxies. Intracluster plasmas possess chaotic magnetic fields. Since charged particles are constrained to move primarily along magnetic field lines, the topology of intracluster magnetic fields slows particle diffusion relative to the non-magnetized case, thereby reducing the thermal conductivity. Our first approach to this problem was to employ the static-magnetic-field approximation. In reality, intracluster magnetic field lines are constantly moving, since they are advected by turbulent intracluster motions. The turbulent velocities, however, are much smaller than the rapid speeds of thermal electrons, which make the dominant contribution to the thermal conductivity. In the static-field approximation, one neglects turbulent motions of field lines, and calculates the diffusion coefficient of thermal electrons ...

Energy Technology Data Exchange (ETDEWEB)

The specific research goal of this project is to identify means to restore and rebuild the Snake River white sturgeon (Acipenser transmontanus) population to support a sustainable annual subsistence harvest equivalent to 5 kg/ha/yr (CBFWA 1997). Based on data collected, a white sturgeon adaptive management plan will be developed. This report presents a summary of results from the 1997-2002 Phase II data collection and represents the end of phase II. From 1997 to 2001 white sturgeon were captured, marked, and population data were collected in the Snake and Salmon. A total of 1,785 white sturgeon were captured and tagged in the Snake River and 77 in the Salmon River. Since 1997, 25.8 percent of the tagged white sturgeon have been recaptured. Relative density of white sturgeon was highest in the free-flowing segment of the Snake River, with reduced densities of fish in Lower Granite Reservoir, and low densities the Salmon River. Differences were detected in the length frequency ...

International Nuclear Information System (INIS)

Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs.

British Library Electronic Table of Contents (United Kingdom)

Over the past three decades, rising competition from television and other new media prompted the FCC to ease the responsibilities of radio stations to maintain extensive records of issues programming, while retaining the responsibility of stations to provide ready public access to records. This study investigated the availability of Issues-Programs Lists in nearly 100 Missouri radio station Public Files. One in five randomly sampled stations failed to produce access to Lists upon demand as required under federal law. Noncompliance themes include: Inability to access Public Files within 20 minutes of face-to-face requests; station personnel with limited or no knowledge of Files; denial of access to Files and Lists (i.e., verbal refusals, locked studio doors); and incomplete Files. The rate ...

International Nuclear Information System (INIS)

This paper reports extensive new optical and radio observations of NGC 5728, emphasizing the central regions. Deep photographs revealing detail in the faint spiral arms are briefly discussed. Broad-band UBV CCD images obtained to examine the colors of the stellar populations that comprise the bar and central ring are presented. The velocity field and emission maps obtained from imaging spectroscopic measurements in the H-alpha emission line are discussed. Conventional long-slit spectra covering the ionized gas in the nuclear region are described. Detailed maps of the radio emission in the central regions of NGC 5728 are presented. These combined data provide considerable evidence for the inflow of gas into the nuclear region, in response to the nonaxisymmetric gravitational potential of the bar. The possible relation of this phenomenon to the Seyfert nature of NGC 5728 is also considered. 48 references.

Energy Technology Data Exchange (ETDEWEB)

High dose rate (HDR) brachytherapy for treating a cervix carcinoma has become popular, because it eliminates many of the problems associated with conventional brachytherapy. In order to improve the clinical effectiveness with HDR brachytherapy, a dose calculation algorithm, optimization procedures, and image registrations need to be verified by comparing the dose distributions from a planning computer and those from a humanoid phantom. In this study, the humanoid phantom was fabricated in order to verify the absolute doses and the relative dose distributions. The measured doses from the humanoid phantom were then compared with the treatment planning system for the dose verification. The humanoid phantom needs to be designed such that the dose distributions can be quantitatively evaluated thermoluminescent dosimeter (TLD) chips with a dimension of 1/8 and film dosimetry with a spatial resolution of <1 mm used to ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes considerations given on factors affecting radon concentrations, and the radon concentration measurements in hot springs distributed in the northern part of Kumamoto Prefecture. As a result of analyzing radon concentration attenuation in the vertically upward direction using a diffusion equation, it was revealed that radon carrier gas velocities affect strongly the radon concentration, and the [sup 220]Rn source is limited to a very shallow bed below the ground surface. An inclined face was prepared against the [sup 222]Rn decay constant distribution using an inclined face analyzing method. The [sup 222]Rn concentration direction based on this inclined face harmonized approximately well with the hot spring distribution direction. Base rocks that well up hot springs were inferred to be granite from the concentration distribution and pH of chemical components in ...

Energy Technology Data Exchange (ETDEWEB)

The assets that Citizen Potawatomi Nation holds were evaluated to help define the strengths and weaknesses to be used in pursuing economic prosperity. With this baseline assessment, a Planning Team will create a vision for the tribe to integrate into long-term energy and business strategies. Identification of energy efficiency devices, systems and technologies was made, and an estimation of cost benefits of the more promising ideas is submitted for possible inclusion into the final energy plan. Multiple energy resources and sources were identified and their attributes were assessed to determine the appropriateness of each. Methods of saving energy were evaluated and reported on and potential revenue-generating sources that specifically fit the tribe were identified and reported. A primary goal is to create long-term energy strategies to explore development of tribal utility options and analyze renewable energy and energy efficiency options. ...

Science.gov (United States)

Howard A. Baldwin and Robert W. Freyman. (NASA-CR-138152) TELEMERY LINK FOR AN. 574-2179 9 ..... Baldwin, H.A., "Long Range Radio Tracking of ...

UK PubMed Central (United Kingdom)

Currently several groups are actively researching the integration of a megavoltage teletherapy unit with magnetic resonance (MR) imaging for real-time image-guided radiotherapy. The use of a...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8--13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, the authors investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C{sub 3} and C{sub 4} and comparing the effects of an active and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 {micro}s, the authors could not detect ...

CERN Document Server

The Westerbork Northern Sky Survey (WENSS) and the NRAO/VLA Sky Survey (NVSS) were used to determine an upper limit to the diffuse radio flux from the nearby cluster Abell 2199. For the entire cluster, this limit is <3.25 Jy at 327 MHz from WENSS; for the inner 15' radius, the limit is <168 mJy at 1.4 GHz. These limits are used to constrain the cluster magnetic field by requiring that the radio flux be consistent with the hard X-ray (HXR) flux observed by BeppoSAX, assuming that the observed HXR excess is due to inverse Compton (IC) scattering of cosmic microwave background photons by relativistic electrons in the intracluster gas. We find that the magnetic field must be very weak (<0.073 uG) in order to avoid producing an observable radio halo. We also consider the possibility that the HXR excess is due to nonthermal bremsstrahlung (NTB) by a population of suprathermal electrons which are being accelerated to ...

International Nuclear Information System (INIS)

The operation and safety of both fossil-fuel and nuclear power stations depend on adequate cooling of the thermal source involved. This is usually accomplished using liquid coolants that are forced through the high temperature regions by a pumping system; this fluid then transports the thermal energy to another section of the power station. However, fluids that undergo boiling during this process create vapor that can be detrimental, and influence safe operation of other system components. The behavior of this vapor, or void, as it is generated and transported through the system is critical in predicting the operational and safety performance. This study uses two advanced penetrating radiation techniques, Real Time Neutron Radiography (RTNR), and High Speed X-Ray Tomography (HS-XCT), to examine void generation and transport behavior in a flow boiling system. The geometries studied were tube side flow boiling in a cylindrical configuration, and a similar flow ...

DEFF Research Database (Denmark)

All-optical envelope detection of a 5 GHz 200 Mbit/s modulated radio frequency signal is achieved using a 650 nm resonant cavity light emitting diode. Error-free transmission is achieved over a 50 m-long link of 1 mm diameter graded index polymer optical fibre (POF). The presented system has potential applications in low cost and low complexity short range wireless and wireline POF-based transmission links.

Energy Technology Data Exchange (ETDEWEB)

The use of global three-dimensional (3-D) models with satellite observations of CO2 in inverse modeling studies is an area of growing importance for understanding Earth s carbon cycle. Here we use the GEOS-Chem model (version 8-02-01) CO2 mode with multiple modifications in order to assess their impact on CO2 forward simulations. Modifications include CO2 surface emissions from shipping (0.19 PgC yr 1), 3-D spatially-distributed emissions from aviation (0.16 PgC yr 1), and 3-D chemical production of CO2 (1.05 PgC yr 1). Although CO2 chemical production from the oxidation of CO, CH4 and other carbon gases is recognized as an important contribution to global CO2, it is typically accounted for by conversion from its precursors at the surface rather than in the free troposphere. We base our model 3-D spatial distribution of CO2 chemical production on monthly-averaged loss rates of CO (a key precursor and intermediate in the oxidation of organic ...

International Nuclear Information System (INIS)

Full text.Surficial sediment samples were collected from seventeen springs distributed all over Lebanon (east, west, north and south). Concentrations of metals Ca, Fe, Mn, Ni, Cu, Cr, Zn and Pb were determined by energy dispersive x-ray fluorescence technique. Irradiation was done by the radioisotope source Cd-109 and the detection by an EG and G Si(Li) detector. These analysis was done in attempt to assess the impact of anthropogenic sources on ground water quality. Metals concentration in sediment were found to be (Ca:0.05-47%, Fe:0.24-4.2%, Cr:

Energy Technology Data Exchange (ETDEWEB)

This report describes the method of Allan variance and its application to the characterization of a Ring Laser Gyro`s (RLG) performance. Allan variance, a time domain analysis technique, is an accepted IEEE standard for gyro specifications. The method was initially developed by David Allan of the National Bureau of Standards to quantify the error statistics of a Cesium beam frequency standard employed as the US Frequency Standards in 1960`s. The method can, in general, be applied to analyze the error characteristics of any precision measurement instrument. The key attribute of the method is that it allows for a finer, easier characterization and identification of error sources and their contribution to the overall noise statistics. This report presents an overview of the method, explains the relationship between Allan variance and power spectral density distribution of underlying noise sources, describes the batch and ...

Energy Technology Data Exchange (ETDEWEB)

The Idaho Chemical Processing Plant (ICPP) Water inventory Study was initiated in September 1993 with the formation of a joint working group consisting of representatives from DOE-ID, State of Idaho INEL Oversight Program, US Geological Survey, and INEL employees to investigate three issues that had been identified by the INEL Oversight Program at ICPP: (1) the water inventory imbalance at ICPP, (2) the source of water infiltrating into the Tank Farm vault sumps, and (3) the source of water providing potential recharge to perched water bodies underlying ICPP. These issues suggested that water was being lost from the ICPP distribution system. The INEL Oversight Program was concerned that the unaccounted for water at ICPP could be spreading contaminants that have been released over the past 40 years of operations of ICPP, possibly to the Snake River Plain Aquifer. This report summarizes the findings of each of the component ...

International Nuclear Information System (INIS)

Brachytherapy refers to short distance treatment of cancer with radiation from small, encapsulated radionuclide sources. This type of treatment is given by placing sources directly into or near the volume to be treated. The dose is then delivered continuously, either over a short period of time (temporary implants) or over the lifetime of the source to a complete decay (permanent implants). This technique is extensively used in the treatments of gynecological, breast, prostate, head and neck, and other soft tissue cancers. The clinical outcomes of this treatment depend on accurate dosimetry and dose delivery. The patient is generally considered to be water equivalent. So the treatment planning system software generally is based on measured or calculated dose distributions in homogenous water medium. In real situation, the treatment volume is not homogenous water medium, but it is a heterogeneous medium ...

Energy Technology Data Exchange (ETDEWEB)

The Internet is becoming the preferred method for disseminating scientific data from a variety of disciplines. This can result in information overload on the part of the scientists, who are unable to query all of the relevant sources, even if they knew where to find them, what they contained, how to interact with them, and how to interpret the results. A related issue is keeping up with current trends in information technology often taxes the end-user's expertise and time. Thus instead of benefiting from this information rich environment, scientists become experts on a small number of sources and technologies, use them almost exclusively, and develop a resistance to innovations that can enhance their productivity. Enabling information based scientific advances, in domains such as functional genomics, requires fully utilizing all available information and the latest technologies. In order to address this problem we are developing a ...

Energy Technology Data Exchange (ETDEWEB)

Using {gamma}-irradiation-induced reduction in the field of a {sup 60}Co {gamma}-ray source, colloidal silver and gold nanoparticles were prepared from their corresponding metal salts in aqueous solution and compared with those by chemical reduction. The radiation-based method provided silver nanoparticles with higher concentration and narrower size distribution than those obtained by chemical reduction method while there was no significant difference between the two strategies for the preparation of gold nanoparticles. {gamma}-Irradiation of 1.0 x 10{sup -3} M AgNO{sub 3} solution resulted in nearly 100 times more highly concentrated silver colloids than those by citrate reduction. Furthermore, the radiation method could lead to more highly concentrated silver colloids by simply increasing the concentration of AgNO{sub 3} solution up to 2.0 x 10{sup -2} M. The two metal nanoparticles prepared by the two different methods were characterized by ...

Energy Technology Data Exchange (ETDEWEB)

Using standard brass alloy samples, an approach to reduce the laser-induced breakdown spectroscopy measurement uncertainty was tested and proved. Two important parameters for plasma characterization, the plasma temperature and the electron density, were applied to minimize the signal uncertainties due to uncontrollable experimental parameter variations. Results show that for the pulse-to-pulse analysis, the signal fluctuations can be significantly reduced by utilizing the plasma characteristic information. The major source for the single pulse fluctuations is the redistribution of the characteristic line at different temperatures according to the Boltzmann distribution under LTE. The change of the degree of ionization also contributes to the signal fluctuations. For the multi-pulse analysis, due to the nonlinear relationship between the plasma temperature and the line intensity, it is not applicable to utilize the Boltzmann ...

International Nuclear Information System (INIS)

The formation and growth of silicon-nanoparticles from silane in a microwave reactor was investigated. Experiments were performed for the following conditions: precursor concentration 380-2530 ppm, pressures of 20-30 mbar, microwave powers 120-300 W. The formed particles were examined in-situ with a particle mass spectrometer. Additionally, particles were collected on grids and analyzed by transmission electron microscopy, X-ray diffraction, and by determining the specific surface area by BET. The particle size was found to be in the range of 5-8 nm in diameter. A simple model was used to simulate the particle formation processes taking place inside the reactor. The microwave energy coupled into the reactor flow was treated as a spatially distributed energy source resulting in a local temperature increase. The particles were assumed to have a monodisperse size distribution. To allow an approximation of their shape they were ...

CERN Document Server

In this work we develop a new propagation model for the Galactic cosmic rays based on the GALPROP code, including contributions from dark matter annihilation. The model predicts compatible Galactic diffuse $\\gamma$ ray spectra with EGRET data in all sky regions. It also gives consistent results of the diffuse $\\gamma$ ray longitude and latitude distributions. Further the results for B/C, $^{10}$Be/$^9$Be, proton, electron and antiproton spectra are also consistent with cosmic ray measurements. In the model we have taken a universal proton spectrum throughout the Galaxy without introducing large fluctuation for the proton energy loss is negligible. The dark matter annihilation signals are `boosted' after taking the contribution from subhalos into account. Another interesting feature of the model is that it gives better description of the diffuse $\\gamma$ rays when taking the source distribution compatible with supernova ...

Energy Technology Data Exchange (ETDEWEB)

Negative ion electrospray ionization (ESI) coupled with high field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) allows for the direct detection of acidic NSO compounds in petroleum. The technique requires no chromatographic separation, is able to distinguish 18 different compound classes (e.g., neutral nitrogen, carboxylic acids and oxygenates), and can identify {approx}14,000 distinct masses by ultra-high mass resolution and mass accuracy. We previously studied three crude oils from different geological origins [Organic Geochemistry 33 (2002b) 743-759]. Here, we expand our research by comparing two source-equivalent Smackover oils of different levels of thermal maturity. We observe clear differences in the distribution of NSO compound classes, types (number of rings plus double bonds within a class), and number of alkyl carbons. With increasing thermal stress, the relative amount of sulfur and oxygen containing ...

Energy Technology Data Exchange (ETDEWEB)

Generation of anomalous resistivity and dynamical development of collisionless reconnection in the vicinity of a magnetically neutral sheet are investigated by means of a three-dimensional particle simulation. For no external driving source, two different types of plasma instabilities are excited in the current layer. The lower hybrid drift instability (LHDI) is observed to grow in the periphery of current layer in an early period, while a drift kink instability (DKI) is triggered at the neutral sheet in a late period as a result of the nonlinear deformation of the current sheet by the LHDI. A reconnection electric field grows at the neutral sheet in accordance with the excitation of the DKI. When an external driving field exists, the convective electric field penetrates into the current layer through the particle kinetic effect and collisionless reconnection is triggered by the convective electric field earlier than the DKI is excited. It is also found that the ...

International Nuclear Information System (INIS)

Lebanon has imported in 1996 5000 Kt of carburants causing about 80 Kt of SO_x; 40 Kt of NO_x; 3 Kt of dusts and 3.5 million tons of CO_2. The atmospheric pollution in Lebanon is due to three main sources: - Thermal central of electric production - Industries (cement) - Transportation sector The document describes in tables: the inventory of pollutants and pollutant emissions in 1993 and 2010; industrial and heating gas oil; liquified petroleum gas commercial propane; fuel oil for EDL; consumption of energy in 1996; sectorial distribution of pollutants PPM; emissions of CO_2 per tons per habitant in 1993; consumption in 1993 broken down by use and application. Finally, three projects concerning public transportation were presented

Energy Technology Data Exchange (ETDEWEB)

Photoemission-electron-microscopy (PEEM) is introduced as a tool for the characterization of organic electronic devices. PEEM-measurements are used for imaging as well as for spectroscopic analyses by illumination with light of a Hg-lamp (4.9 eV), a D2 lamp (7.3 eV), and with synchrotron radiation for resonant photoelectron spectroscopy. We determine the charge carrier concentration inside the channel region of the organic device and its lateral distribution. From resonant photoelectron spectroscopy (RPES) we deduce the electronic states which are accessible with the Hg and D2 illumination. Photoelectron-spectroscopy at selected areas ({mu}-PES) gives information on the absolute values of surface potentials in lateral resolution. We are able to perform these studies with applied voltages at the source- and drain-electrode.

International Nuclear Information System (INIS)

A neutron scanning device was developed in order to obtain accurate neutron intensities of high burn-up BWR fuels. This scanning device was calibrated with a "2"5"2Cf source and used to measure axial distributions of neutron intensities of BWR fuels with various enrichments (2.0%-3.4%) irradiated up to 60 GWd/tU at Fukushima Daini Nuclear Power Station Unit 2(2F-2). The measured neutron intensities were approximated well with power law interpolations on the calculated burn-up values. The neutron intensities calculated by the ORIGEN2-86 code showed good agreements with the measured ones within 20%. (author)

Energy Technology Data Exchange (ETDEWEB)

This paper presents research work concerning the mathematical modelling of air pollution in the Athens basin. A mathematical model based on aerodynamics and conservation equations together with turbulence modelling in body-fitted coordinates is used to provide the necessary input information to a similar but more detailed (i.e. small scale) model around Athens. Both models consist of solving the full Navier-Stokes equations and take into account the precise topography of the region. Different roughness heights are used for sea, coastal regions and land. The smaller scale model makes use of a two-equation turbulence model ({kappa}-{epsilon}) and the large scale model assumes a constant turbulence viscosity. The pollutant sources used in these models are based on actual emissions in the Athens area and are distributed in space. The results of this work appear promising and demonstrate the capability of the model as a tool for providing flow ...

British Library Electronic Table of Contents (United Kingdom)

Since the end of the 1990s, good quality lighting was that which balanced the needs of humans, economic and environmental issues, and architectural design. Recent studies aimed to find a correlation between environmental lighting and human performance and health, with positive results. What is known, is that insufficient or inappropriate light exposure can disrupt standard human rhythms which may result in adverse consequences for performance, safety, health. By studying the relationship between human physiology and light, research in photobiology has advanced to the point where some attempts to foresee what the lighting practice will be in future. The question is if lighting practice and lighting practitioners are ready for changes. This paper has the aim of introducing the recent discove...

British Library Electronic Table of Contents (United Kingdom)

Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946?58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10?days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-...

International Nuclear Information System (INIS)

We report on severe accident scenarios consequences evaluation in connection to the applied emergency countermeasures and use of the PC COSYMA code. We present some of the results for the reactor core melt accident assumed to happen at the 632 MWE PWR Krsko Nuclear Power Plant in Slovenia. The efficiency of several potential countermeasures in limiting the late health effects was studied. Regarding the source term, the majority of release parameters are as specified for category 2 in the German Risk Study. Site specific data were used. As the outside (meteorologic) conditions during the potential accident onset can be very different, the study limited to the deterministic runs, assuming the wind direction upstream the Sava river into the WNW direction, wind speed of 5 ms -1 and the C Pasquill stability category. The population distribution file was formed from the NEK-FSAR data for the 1991. (author)

British Library Electronic Table of Contents (United Kingdom)

The early Miocene Pedregoso Formation is one of the numerous formations rich in organic matter within the stratigraphic record of the Urumaco Trough, in the central area of the Falcon Basin. Due to its lithological characteristics and stratigraphic position, this formation is of great interest regarding the basin's petroliferous systems. The evaluation of various inorganic and organic geochemical parameters indicates that the organic matter is primarily of marine origin, deposited in a marine carbonate environment typical of reefal systems, under oxic-to-dysoxic conditions. The low variability in the TOC concentrations and in the distributions of the biomarkers extracted from the samples suggests that the paleoenvironmental conditions and the organic-matter supply remained approximately co...

International Nuclear Information System (INIS)

A high sensitivity, high bandwidth, two-color interferometer (1064 and 532 nm) has been tested on the Hawk pulsed power generator at the Naval Research Laboratory. The phase resolution is 10"-"5 waves with a rise time of 3 ns, a new capability for diagnosing plasmas, and neutrals in pulsed power experiments. The two-color feature is used to distinguish phase shifts from free (plasma) electrons and bound (neutral and ion) electrons. Simultaneous electron and neutral density measurements were demonstrated in a plasma opening switch (POS) experiment. The ability to measure small phase shifts with fast rise time were demonstrated in a plasma filled diode experiment. The high sensitivity and vibration isolation enable neutral gas distribution measurements from supersonic nozzles used in plasma radiation source experiments. Examples of these measurements and future applications are described. copyright 1997 American Institute of Physics.

Energy Technology Data Exchange (ETDEWEB)

The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm{sup -3} or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant applications. Many of the design features and the end application itself ...

Energy Technology Data Exchange (ETDEWEB)

Milk can be a significant source of lead (Pb) for young mammals, including humans. Certain essential trace elements have previously been shown to be specifically associated with particular milk components and such associations often increase bioavailability. Thus, the first goal of this study was to determine the distribution of Pb in cream, casein, and whey fractions of various milks under various conditions using /sup 203/Pb as a tracer. In rat milk almost 90% of the Pb was found to be associated with the casein micelles, regardless of: 1) whether the milk was labeled in vivo or in vitro; b) whether the milk was fresh or frozen; and c) the added concentration of Pb. The remainder of the Pb was approximately equally distributed between cream and whey. A virtually identical pattern of Pb distribution was observed with bovine milk. Pb added to infant formula also associated predominantly with casein ...

Energy Technology Data Exchange (ETDEWEB)

The Advanced Photon Source consists of five accelerators. The injection timing system provides the signals required to cause a bunch emitted from the electron gun to navigate through intermediate accelerators to a specific bucket (1 out of 1296) within the storage ring. Two linacs and a positron accumulator ring operate at 60Hz while a booster synchrotron ramps and injects into the storage ring at 2Hz. The distributed, modular VME/VXI-based injection timing system is controlled by two EPICS-based input/output controllers (IOCs). Over 40 VME/VXI cards have been developed to implement the system. Card types range from 352MHz VXI timing modules to VME-based fiber optic fanouts and logic translators/drivers. All timing is distributed with fiber optics. Timing references are derived directly from machine low-level rf of 9.77MHz and 352MHz. The timing references provide triggers to programmable delay generators. Three grades of ...

Energy Technology Data Exchange (ETDEWEB)

Several recent improved methods for the EGFM are introduced in order to avoid artificial holes seen in the synthetic acceleration spectrum. Furthermore evaluation of input ground motions at Wolsung NPP are performed by varying the source parameters that may control the high-frequency wave radiation and the deviation of the synthetic motions are revealed. The PSHA case studies for four NPP sites (Wolsung, Kori, Uljin, Younggwang) are performed. In the analysis, site-specific attenuation equations developed for Korean NPP sites are employed, and the seismic hazards for the target sites are evaluated in the case where the four kind of seismic source models are considered. Moreover, the PSHA for Wolsung and Younggwang are conducted by using the site-specific attenuation equation with the index of response spectra and the uniform hazard spectra are evaluated for the two sites. The supporting tool for seismic response analysis and the evaluation tool ...

International Nuclear Information System (INIS)

The most important factor in assessing radiologic risk is ensuring scientific means for evaluation of the radioactive release impact upon humans and organisms. To evaluate quantitatively this impact not only knowledge of radioactivity distribution in these dynamical systems is necessary but also understanding the transfer mechanisms between ecosystem components is needed. Thus a complete radioecologic study appear to be very complex and needs defining the source term, dynamic description of radionuclides behavior in the ecosystem, estimation of radiation doses in the major components of the ecosystem and finally the effects of radiation doses upon different parts of the systems. A diagram of the steps implied in evaluation of the effects due to radioactive effluent release in the environment is presented and discussed. The following steps are described: - identification of radioactive sources, as well as their input rate. ...

Energy Technology Data Exchange (ETDEWEB)

The Oligocene Kishenehn Formation of northwest Montana and southeast British Columbia consists of fluvial and lacustrine sediments (marlstones, lignites and oil shales) deposited in an elongate, intermontane half-graben. The petroleum source rock potential and steroidal hydrocarbon distribution of selected shales of the Kishenehn Formation were examined. Several steroidal hydrocarbon series were documented, including 4-desmethylsteranes, 4-methylsteranes, sterenes, diasterenes, spirosterenes, C-ring monoaromatic steroids and B-ring monoaromatic anthrasteroids. Non-steroid hydrocarbons present include hopenes, ..beta beta..-hopanes, moretanes, perylene, botryococcane, a series of alkylcyclohexanes, and a fused-ring aromatic tentatively identified as a tetrahydrochrysene. Source rock analysis indicates that the Kishenehn Formation possesses excellent petroleum source potential. Conventional thermal ...

Energy Technology Data Exchange (ETDEWEB)

The Sperchios Basin is an active asymmetric graben, bounded to the south by a major border fault system with major fault segments typically 20-30 km long. The basin is dominated by a major axial fluvio-deltaic system which enters the partially enclosed Maliakos Gulf to the east. Lateral sourced depositional systems within the basin comprise hanging-wall and footwall-derived alluvial fans and a narrow coastal plain along the footwall scarp bordering the Maliakos Gulf. High resolution seismic data from the Maliakos Gulf reveals three late Quaternary progradational parasequences sourced from axial and lateral depositional systems, with a regional late-Pleistocene transgressive surface dated at circa. 10 ka BP within the Maliakos Gulf. Differential subsidence of the late Pleistocene transgressive surface indicates marked variation in subsidence from 2.4 m ka[sup -1] at fault segment centers to 0.8 m ka[sup -1] at segment boundaries. The geometry ...

Energy Technology Data Exchange (ETDEWEB)

The Ordos Basin, the second largest sedimentary basin in China, contains the broad distribution of natural gas types. So far, several giant gas fields have been discovered in the Upper and Lower Paleozoic in this basin, each having over 1000x10{sup 8}m{sup 3} of proven gas reserves, and several gas pools have also been discovered in the Mesozoic. This paper collected the data of natural gases and elucidated the geochemical characteristics of gases from different reservoirs, and then discussed their origin. For hydrocarbons preserved in the Upper Paleozoic, the elevated {delta}{sup 13}C values of methane, ethane and propane indicate that the gases would be mainly coal-formed gases; the singular reversal in the stable carbon isotopes of gaseous alkanes suggests the mixed gases from humic sources with different maturity. In the Lower Paleozoic, the {delta} {sup 13}C{sub 1} values are mostly similar with those in the Upper Paleozoic, but the ...

Energy Technology Data Exchange (ETDEWEB)

In response to the Energy Policy Act of 1992 and the Federal Energy Regulatory Commission`s subsequent rulemaking on transmission access, many states are exploring options to restructure their electric industries. In their deliberations on restructuring, policymakers should consider (1) the reliability of the electric system; (2) income-distribution effects on ratepayers and utilities; (3) social consequences such as effects on energy conservation, renewable energy, and the environment; and (4) economic efficiency. We address economic-efficiency considerations in this study. Economic efficiency is important because it is one of the primary reasons that policymakers should consider restructuring in the first place: improving the electric-industry`s efficiency lowers costs and, hence, electric prices. In this study, we look at the sources of (in)efficiency in existing and proposed electric markets with the objective of guiding policymakers to ...

Energy Technology Data Exchange (ETDEWEB)

Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase I/II clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra alternative neutron sources are being ...

Energy Technology Data Exchange (ETDEWEB)

Environmental exposure measurements are, in general, positive and may be subject to left censoring; i.e,. the measured value is less than a ''detection limit''. In occupational monitoring, strategies for assessing workplace exposures typically focus on the mean exposure level or the probability that any measurement exceeds a limit. Parametric methods used to determine acceptable levels of exposure, are often based on a two parameter lognormal distribution. The mean exposure level, an upper percentile, and the exceedance fraction are used to characterize exposure levels, and confidence limits are used to describe the uncertainty in these estimates. Statistical methods for random samples (without non-detects) from the lognormal distribution are well known for each of these situations. In this report, methods for estimating these quantities based on the maximum likelihood method for randomly left censored ...

Energy Technology Data Exchange (ETDEWEB)

Ferrofluids have promising potential for heat transfer applications, since advective transport in a ferrofluid can be readily controlled by using an external magnetic field. However, unlike conventional free or forced convection, ferrohydrodynamic convection is not yet well characterized. A full understanding of the relationship between an imposed magnetic field, the resulting ferrofluid flow, and the temperature distribution is a prerequisite for the proper design and implementation of applications involving thermomagnetic convection. The literature variously assumes constant magnetic fields, does not completely represent the variation in the imposed field, or its descriptions are inaccurate, since the fields do not comply with the Maxwell's equations of electromagnetism. We address this by simulating two-dimensional forced convection heat transfer in a channel with a ferrofluid that is under the influence of a two-dimensional magnetic field created by a ...

International Nuclear Information System (INIS)

Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946-58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10 days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-, biological-, and environmental-specific impacts of residual high activity (hot) particle contamination. The aim of the present study was twofold; (i) to characterize the levels ...

International Nuclear Information System (INIS)

Since 1988, the Expertise group of Molecular and Cellular Biology (MCB) is an important partner in the development of the Micro-Ecological Life Support System Alternative (MELiSSA). The MELiSSA was designed to allow a small crew to survive on an Antarctic, lunar or Mars outpost, and is a joint research project currently fostered by the European Space Agency, ESA. The MELiSSA functions through a series of five interconnected compartments, of which four are microbial bioreactors and was engineered to degrade organic waste, regenerate the outpost's atmosphere and water, and provide the crew with an additional vegetarian diet. The bioreactor of the third compartment provides the edible cyanobacteria and plants of the fourth compartment with nitrate instead of ammonium as a source of nitrogen. The two bacteria responsible for the biological transformation of ammonium to nitrate (nitrification) are Nitrosomonas europaea and Nitrobacter winogradskyi. Since all ...

CERN Document Server

In this review, I concentrate on describing observations of spatially resolved emission in symbiotic stars at sub-arcsecond scales. In some of the closer objects, the highest resolutions discussed here correspond to linear dimensions similar to the supposed binary separation. A total of 17 stars well accepted as symbiotics are now observed to show sub-arcsecond structure, almost twice the number at the time of the last review in 1987. Furthermore, we now have access to HST imagery to add to radio interferometry. From such observations we can derive fundamental parameters of the central systems, investigate the variation of physical parameters across the resolved nebulae and probe the physical mechanisms of mass loss and interactions between ejecta and the circumstellar medium. Suggestions for future work are made and the potential of new facilities in both the radio and optical domains is described. This review complements that by Corradi (this ...

CERN Document Server

We review the current status of resolved X-ray emission associated with extragalactic radio jets and hotspots. The primary question for any particular jet is to decide if the X-rays come from the synchrotron process or from inverse Compton scattering. There is considerable evidence supporting synchrotron emission for knots in the jets of FRI galaxies. For FRII terminal hotspots detected in the X-ray band, synchrotron self-Compton emission continues to provide viable models with one possible exception (so far). Inverse Compton scattering on photons of the cosmic microwave background is indicated for a few powerful jets, and is expected to be an important contributor if not the dominating mechanism for higher redshift objects. The application of a model generally yields physical parameters and in many cases, these include the Doppler boosting factor.

International Nuclear Information System (INIS)

High-resolution observations are presented of the 300-kpc jet in the giant radio galaxy NGC 6251. The width of the jet is resolved over most of its length, and the axis of the jet wiggles with an amplitude increasing linearly with distance from the nucleus. Polarization data are used to derive densities of cold matter in the jet and, from the argument that the jet must form the lobe in a time equal to the age of the lobe, the speed of the jet is estimated as c/20. The energetics of the jet are then dominated by the bulk flow along it of cold matter at a rate of 1 solar mass yr"-"1. The jet appears to be confined; the wiggle of its axis is probably due to oscillations of the direction of the collimator with a period of about 6 x 10"6 yr. (author).

British Library Electronic Table of Contents (United Kingdom)

A novel method of simultaneous realization of optical carrier-suppression and single-sideband modulation using fiber Fabry-Perot tunable filter is presented. In order to enhance transmission performance of radio over fiber links, we use a fiber Fabry-Perot tunable filter to filter out one sideband as well as suppress the optical carrier power. The results demonstrate 20.5dB and 14.2dB improvement in the signal noise ratios when 18GHz and 10GHz microwave signals carrying 5Mbit/s quadrature-phase-shift-keyed (QPSK) format data is transmitted over 35 km single mode fiber, respectively.

Energy Technology Data Exchange (ETDEWEB)

The contents include: Detailed index for 1991; Data for November 1991--Solar-terrestrial environment, IUWDS alert periods (advance and worldwide), Solar activity indices, Solar flares, Solar radio emission, Stanford mean solar magnetic field; Data for October 1991--Solar active regions, Sudden ionospheric disturbances, Solar radio spectral observations, Cosmic ray measurements by neutron monitor, Geomagnetic indices; Late data--Cosmic ray measurements by neutron monitor (Climax February and May 1990, Deep River May-August 1991), Geomagnetic indices (Sudden commencements/Solar flare effects January-May 1991); Errata--August 1991 Geomagnetic activity indices.

International Nuclear Information System (INIS)

Nitriding of aluminium 2011 using a radio frequency plasma at higher power levels (500 and 700 W) and lower substrate temperature (500 deg. C) resulted in higher AlN/Al_2O_3 ratios than obtained at 100 W and 575 deg. C. AlN/Al_2O_3 ratios derived from X-ray photoelectron spectroscopic analysis (and corroborated by heavy ion elastic recoil time of flight spectrometry) for treatments preformed at 100 (575 deg. C), 500 (500 deg. C) and 700 W (500 deg. C) were 1.0, 1.5 and 3.3, respectively. Scanning electron microscopy revealed that plasma nitrided surfaces obtained at higher power levels exhibited much finer nodular morphology than obtained at 100 W.

Energy Technology Data Exchange (ETDEWEB)

Thin passive layers of uranium nitride were formed by nitriding pure metallic uranium in non-equilibrium, low pressure radio-frequency plasma of nitrogen. Plasma nitriding at low substrate temperature of 230 C-250 C was found to cause the formation of adherent layers of uranium sesquinitride ({alpha}-U{sub 2}N{sub 3}) which provide a considerable protection against hydrogen attack. The characteristics of these passivation layers were determined by X-ray diffraction and Auger electron spectroscopy. The incipient hydriding kinetics of the plasma-treated samples were compared with those of untreated and nitrogen-ion implantation ones, utilizing a hot-stage microscope that was monitored continuously with a TV camera and videotape. (orig.)

British Library Electronic Table of Contents (United Kingdom)

Abstract In this paper, a Cognitive Radio Based Medium Access Control (CR-MAC) protocol for Wireless Sensor Body Area Networks (WSBAN) that utilizes cognitive radio transmission is proposed. In this proposal, the sensor nodes are classified into nodes of life-critical health information and nodes of non-critical health information. The CR-MAC protocol prioritizes the critical packets access to the transmission medium by transmitting them with higher power while transmitting lower priority packets using lower transmission power. At the receiver, a higher priority packet experiences collision only when there are more than one critical packet transmission at the same transmission slot while non critical packets experience collision when there are more than one transmission at the same transmi...

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The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building ...

UK PubMed Central (United Kingdom)

ObjectiveTo examine the extent to which the regional and neighborhood distribution of HIV in Tanzania is caused by the differential distribution of individual correlates...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

...2010-10-01 false Ordering from Government supply sources. 51.103 Section 51.103...CONTRACTORS Contractor Use of Government Supply Sources 51.103 Ordering from Government supply sources. (a) Contractors placing...

Science.gov (United States)

No abstract available.

International Nuclear Information System (INIS)

The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 (angstrom)s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 microm, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from backscattering at the target under oblique ...

Energy Technology Data Exchange (ETDEWEB)

The thesis describes work undertaken as part of a larger remote sensing based project which aims to detect, measure and monitor coal fires in two test areas in northern China. The first main topic addressed in this thesis is the detection of fires using several different thermal remote sensing data sets. The synergistic use of the different data sets is emphasised. The second major part of the thesis deals with thermal modelling of the coal fires. Three different models are developed, which allow a fire's depth, temperature, extent, total heat output and rate of movement to be determined. The models are tested both in the laboratory and using various field data sets. A model based on the assumption that the fire is a point heat source and that the temperature distribution around it is spherically symmetrical is shown to be the most effective. A simpler, one-dimensional coal fire model and a model based on the finite element method are ...

International Nuclear Information System (INIS)

The feasibility of utilizing photoelectrochemical and electrolytical technologies to convert energy from the sun and wind into hydrogen was studied. In exploring opportunities to reduce the cost of hydrogen production through interaction with the electric utility grid, it was found that direct photoelectrochemical (PEC) conversion of sunlight has the economic potential to compete with direct photovoltaic/electrolysis, notwithstanding the significant stability and efficiency issues that are still awaiting solution. Interaction with the grid, while maximizing electrolizer use, makes a significant impact on the economics of producing hydrogen by photovoltaic/electrolysis, making wind-based systems also more economical. Electrolysis was found to be the optimal solution only with electricity from renewable sources or with less expensive non-peak electricity. On the other hand, the delivered cost of hydrogen was found to the lowest when electricity production was ...

CERN Document Server

We present results from a large volume simulation of Hydrogen reionization. We combine 3d radiative transfer calculations and an N-body simulation, describing structure formation in the IGM, to detail the growth of HII regions around high redshift galaxies. Our simulation tracks 1024^3 dark matter particles, in a box of side length 65.6 Mpc/h. This large volume allows us to accurately characterize the size distribution of HII regions throughout most of the reionization process. At the same time, our simulation resolves many of the small galaxies likely responsible for reionization. It confirms a picture anticipated by analytic models: HII regions grow collectively around highly-clustered sources, and have a well-defined characteristic size, evolving from a sub-Mpc scale at the beginning of reionization to R>10 Mpc towards the end. We present a detailed statistical description of our results, and compare them with a numerical hybrid scheme ...

International Nuclear Information System (INIS)

Interest in renewable energy systems that employ regenerative components to enable intermittent energy sources to service time varying loads is growing. The overall performance of these systems is intimately linked to the choice of the energy storage media and the efficiency of the energy conversion devices. Recent advances in electrolyser and fuel cell technologies may make small-scale hydrogen buffered renewable energy systems a practical reality in the near term. A research team at the University of Victoria - Institute for Integrated Energy Systems (IESVic) is developing a flexible distributed, laboratory-scale energy system called IRENE (Integrated Renewable Energy Experiment). The initial goal of this research is to explore the potential for constructing a regenerative energy system using early commercial and precommercial hydrogen storage and fuel cell energy conversion devices. Once implemented, research efforts will focus on the ...

Energy Technology Data Exchange (ETDEWEB)

Conventional methods of financing power generation, transmission and distribution in India cannot keep pace with the ever-growing demand. Alternative methods are discussed. Given the vast growth potential, funding can be by equity or debt capital or a hybrid of these. There is an urgent necessity to develop local capital markets as a source of funds since there are limits to how much can be derived from foreign investors, multilaterals and export credit agencies. The domestic financial institutions have raised large amounts for private investment in other sectors. With the creation of a proper climate and power companies set up with an attractive rate of return, sufficient capital could be forthcoming from both domestic and external markets for the power sector. In other sectors, Indian companies have been able to attract investment through Global Depository Receipts and Euroconvertible Bonds, for example. A key requirement for the power sector ...

Science.gov (United States)

Prepared to make housing project managers, maintenance engineering staff, and designers and architects of HUD - assisted and HUD - insured housing projects and mobile home parks aware of their responsibilities under the Natural Gas Pipeline Safety Act, this handbook provides technical guidance for the reduction of gas leaks and the handling of gas leak incidents in residential areas. The hazards of natural gas, concern over gas safety in residential areas, applicable codes and standards, and sources of information and help are reviewed, along with maintenance and engineering considerations relating to gas pipe failures, the detection of gas leaks, appliance servicing, and pipe installation, repair, and replacement. Housing management considerations are also examined, with attention to recordkeeping and reporting, emergency contingency planning, tenant education, staff qualifications and training, and the development and use of a maintenance and operations manual. ...

Energy Technology Data Exchange (ETDEWEB)

A brief comparative review of possible mercury free fluorescent lighting technologies is presented, including rare-gas positive column discharges, molecular discharges, and dielectric barrier discharges. Detailed experimental results on xenon positive column discharges will then be considered. In order to judge whether xenon-based discharges are a viable UV source it is necessary to measure the radiant emittance (power per unit area) for the vacuum ultraviolet (VUV) resonance xenon emission at 147 nm. Two techniques to determine the VUV radiant emittance have been developed and applied to xenon discharges. One method combines the measured resonance level density using absorption spectroscopy and a calculation of the trapped decay rate for the resonance radiation to arrive at the radiant emittance at 147 nm. A second method utilizes a direct measurement of the radiance (power per unit area per unit solid angle) at 147 nm using a calibrated VUV photodiode, and a ...

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A considerable amount of chemical knowledge of marine sediments has been acquired in recent years but has not yet been utilized by paleomagnetists. On the other hand, geochemists are often unaware of the usefulness of numerous magnetic techniques. In this review we try to bridge this gap, and in particular, we outline many of the chemical and magnetic principles that should allow paleomagnetists to better identify and undertand chemical changes that affect the magnetic properties of marine sediments. The chemical principles include those for distinguishing the four major sources of sediments (continental, biological, authigenic/hydrogenous, volcanic/hydrothermal) from one another by determining elemental abundance distributions, as well as for investigating the stabilities of mineral phases relative to changes in pE and pH. The magnetic principles include the effects of authigenesis and diagenesis on magnetic properties, particularly on the ...

Energy Technology Data Exchange (ETDEWEB)

The influence of high energy electron (23 MeV) irradiation on the electrical characteristics of p-channel polysilicon thin film transistors (PSTFTs) was studied. The channel 220 nm thick LPCVD (low pressure chemical vapor deposition) deposited polysilicon layer was phosphorus doped by ion implantation. A 45 nm thick, thermally grown, SiO{sub 2} layer served as gate dielectric. A self-alignment technology for boron doping of the source and drain regions was used. 200 nm thick polysilicon film was deposited as a gate electrode. The obtained p-channel PSTFTs were irradiated with different high energy electron doses. Leakage currents through the gate oxide and transfer characteristics of the transistors were measured. A software model describing the field enhancement and the non-uniform current distribution at textured polysilicon/oxide interface was developed. In order to assess the irradiation-stimulated changes of gate oxide parameters the gate ...

Energy Technology Data Exchange (ETDEWEB)

Operation safety and reliability are major guidelines in the design of city-gate units. Conventional natural gas heaters operate by a indirect mechanism, where liquid water is used to transfer heat by natural convection between the combustion chamber and the natural gas coil. In this work, the concept of vapor chamber is evaluated as an indirect gas heater. In a vapor chamber, liquid water is in contact with the heat source, and vaporizes. The vapor condenses in contact with the heat sink. A reduced scale model was built and tested in order to compare these two heating concepts where the combustion chamber was replaced by electrical cartridge heaters. This engineering model can operate either as a conventional heater or as a vapor chamber. The comparison between the concepts was done by inducing a controlled power to the cartridges and by measuring the resulting temperature distributions. In the novel design, the heat exchanger efficiency ...

Energy Technology Data Exchange (ETDEWEB)

A method of grafting lignin-containing materials is now known which allows 1-phenylethylene or 4-methyl-2-oxy-3-oxopent-4-ene graft copolymers of wood to be quantitatively made. Graft copolymer is formed by conducting a free-radical polymerization with 1-phenylethene in nitrogen-saturated, organic or aqueous/organic solvent containing a lignin source, calcium chloride, and a hydroperoxide. Grafting changes solubility and surface properties of the wood. The lignin-containing materials grafted are unbleached wood pulps produced by chemical, thermal, and mechanical pulping. Grafting wood pulp produces a wood-reinforced, thermoplastic composite. When a particular plastic is to be blended with wood, we react the wood with the monomer used to make that plastic. This creates a hydrophobic surface of the plastic on the wood. This plastic coating can readily bond to the continuous plastic phase. The products of this grafting reaction are thermoplastic composites with ...

International Nuclear Information System (INIS)

A simulated hull monitoring system based on passive #gamma# ray scanning was set-up in K-01 hot-cell, which consists of a simulated hull basket, a collimator system, a 150 cm"3 HPGe detector and an ORTEC-919 multichannel buffer-computer system. Six different kinds of experimental set-up were established to simulate the variations of #gamma# ray source term distribution (partly concentration) and the variations of matrix density (+46.1%). The experimental results show that the biases of peak area is better than -25.3% for "1"3"7Cs 662 keV #gamma# rays and -18.6% for "1"4"4Ce-"1"4"4Pr 2186 keV #gamma# rays. The hardness of pulse height spectrum is demonstrated to show that the peak area ratio of 2186 keV to 662 keV varies from 380 to 72 when the thickness of lead filter varies form 5 mm to 30 mm. Also studied are the design parameters of collimator system.

Energy Technology Data Exchange (ETDEWEB)

LiFePO{sub 4} cathode materials with distinct particle sizes were prepared by a planetary ball-milling method. The effects of particle size on the morphology, thermal stability and electrochemical performance of LiFePO{sub 4} cathode materials were investigated. The ball-milling method decreased particle size, thereby reducing the length of diffusion and improving the reversibility of the lithium ion intercalation/deintercalation. It is worth noting that the small particle sample prepared using malonic acid as a carbon source achieved a high capacity of 161 mAh g{sup -1} at a 0.1 C rate and had a very flat capacity curve during the early 50 cycles. However, the big particle samples ({proportional_to}400 nm) decayed more dramatically in capacity than the small particle size samples ({proportional_to}200 nm) at high current densities. The improvement in electrode performance was mainly due to the fine particles, the small size distribution, and ...

Energy Technology Data Exchange (ETDEWEB)

Experimental and theoretical research has been conducted jointly at the Livermore and Los Alamos National laboratories on dc electromagnetic railgun Lorentz accelerators. Pellets weighing a few grams to tens of grams have been launched at velocities up to better than 11 km/s. The research is addressed to attaining repeated launches of samples at hypervelocity in target impact experiments. In these experiments, shock-induced pressures in the tens of megabars range are obtained for high pressure equation-of-state research. Primary energy sources of the order of several hundred kJ to a MJ and induction currents of the order of 1 or more MA are necessary for these launches. Erosion and deformation of the conductor rails and the accelerated sample material are continuing problems. The heating, stress, and erosion resulting from simultaneous imposition of rail induction current, dense plasma (armature) interaction, current distribution, magnetic ...

Energy Technology Data Exchange (ETDEWEB)

This article provides a survey of neutron scattering experiments in condensed matter research, which are of interest to chemistry. The theoretical background has been treated in a previous issue. The present article consists of two parts. The first part exhibits the range of experimental possibilities by means of a few selected examples. The starting point is classical neutron diffraction by which the position of atomic nuclei may be determined. Additional information on the spatial distribution in the outer electron shells may be obtained via combined X-ray/neutron-diffraction experiments or via the diffraction of polarized neutrons. Progress in instrumentation, due to the development of more intense sources, has influenced especially the fields of small angle scattering and spectroscopy. The second part features domains of research of current interest, where a combination of several neutron scattering techniques may prove to be necessary. ...

Energy Technology Data Exchange (ETDEWEB)

Experiments on aqueous TiO{sup 2} photocatalytic reaction characteristics of 4 nitrogen-containing and 12 aromatic organic compounds were carried out. Based on the values calculated for the distribution of ionic species and atomic charge, the characteristics of their photocatalytic decomposition were estimated. It was shown that the dependence of decomposition of the N-containing compounds were linearly proportional to their nitrogen atomic charge values, while that of the aromatic compounds were inversely proportional. The effects of aqueous pH, oxygen content and concentration on the TiO{sup 2} photocatalytic characteristics of EDTA-Cu(II) and EDTA-Fe(III) were experimentally investigated. All EDTA systems were decomposed better in the pH range of 2.5{approx}3.0 and with more dissolved oxygen. These results could be applied to a unit process for removal of organic impurities dissolved in a source water of the system water, and for treatment ...

International Nuclear Information System (INIS)

Global angular momentum balance suggests that the neutron stars in Be/X-ray binaries are not spinning in equilibrium. This requires an X-ray lifetime ''approx <'' 10"5 yr, and suggests that there are many 'dead' Be/X-ray binaries in the Galaxy. Some of these may be turned up as millisecond radio pulsars with Be star companions. (author).

International Nuclear Information System (INIS)

Scintigraphic imaging of dementia relies today essentially on the study of brain Single Photo Emission Computed Tomography (SPECT) perfusion, after intravenous injection of 99mTc radio-pharmaceutic. This paper is based on the guidelines published in October 2001 by the European Association of Nuclear Medicine (http://eanm.org/). (author)

Energy Technology Data Exchange (ETDEWEB)

The advantages of radiofrequency and microwaves, such as volumetric heating, rapid and selective heating, compactness of equipment and ease of operation, offer sound economic alternative heating techniques. This article discusses dielectric loss, its quantification, and how it is put to effective use, including the use of applicators. Brief recommendations are presented for whether to select radio frequency or microwaves for a particular application. Uses of radiofrequency and microwaves in the industrial, domestic and medical sectors are described.

Energy Technology Data Exchange (ETDEWEB)

Microwaves improve the rate of many chemical reactions either interacting with the solvent, when the reaction is carried out in solution, or with the surface of a solid substrate where a suitable reagent is dispersed (dry chemistry). A few examples of chemical reactions positively affected by microwaves are described: particularly interesting are those concerning polymers and radio-pharmaceuticals.

Energy Technology Data Exchange (ETDEWEB)

The method of double microwave--radio-frequency resonance has been used to obtain spectra of the 2/sub 11/reverse arrow2/sub 12/ and 3/sub 21/reverse arrow3/sub 22/ transitions in HCOOD, DCOOH, and HCOOH molecules. The constants of the quadrupole bond of the deuterons have been determined, magnetic interactions being taken into acocunt. A comparison with results of previous studies is given.

Energy Technology Data Exchange (ETDEWEB)

The SciDAC2 accelerator project at SLAC aims to simulate an entire three-cryomodule radio frequency (RF) unit of the International Linear Collider (ILC) main Linac. Petascale computing resources supported by advances in Applied Mathematics (AM) and Computer Science (CS) and INCITE Program are essential to enable such very large-scale electromagnetic accelerator simulations required by the ILC Global Design Effort. This poster presents the recent advances and achievements in the areas of CS/AM through collaborations.

Energy Technology Data Exchange (ETDEWEB)

This book presents the current knowledge about the effects of electromagnetic fields on living matter. The three-part format covers dielectric permittivity and electrical conductivity of biological materials; effects of direct current and low frequency fields; and effects of radio frequency (including microwave) fields. The parts are designed to be consulted independently or in sequence, depending upon the needs of the reader. Useful appendixes on measurement units and safety standards are also included.