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Current studies in plants suggest that the content of the coenzyme NAD is variable and potentially important in determining cell fate. In cases that implicate NAD consumption, re-synthesis must occur to maintain dinucleotide pools. Despite information on the pathways involved in NAD synthesis in plants, the existence of a mitochondrial nicotinamide mononucleotide adenylyltransferase (NMNAT) activity which catalyses NAD synthesis from nicotinamide mononucleotide (NMN) and ATP has not been reported. To verify the latter assumed pathway, experiments with purified and bioenergetically active mitochondria prepared from tubers of Jerusalem artichoke (Helianthus tuberosus L.) were performed. To determine whether NAD biosynthesis might occur, NMN was added to Jerusalem artichoke mitochondria (JAM)...

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Silent information regulators are potent NAD⁺-dependent protein deacetylases, which have been shown to regulate gene silencing, muscle differentiation and DNA damage repair. Here,...Full Text Available

UK PubMed Central (United Kingdom)

The cofactor nicotinamide adenine dinucleotide (NAD+) has emerged as a key regulator of metabolism, stress resistance and longevity. Apart from its role as ...Full Text Available

UK PubMed Central (United Kingdom)

A two-step purification protocol was used in an attempt to separate the constitutive NAD(P)H-nitrate reductase [NAD(P)H-NR, pH 6.5; EC 1.6.6.2] activity from the nitric oxide and nitrogen dioxide (NO_(x))...Full Text Available

Czech Academy of Sciences Repository

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British Library Electronic Table of Contents (United Kingdom)

Cytoplasmic male sterility (CMS) is a maternally inherited trait that fails to produce functional pollen grains. The CMS system is widely employed to facilitate the utilization of heterosis in major crops. However, little is known about the CMS associated genes in Upland cotton (Gossypium hirsutum). The objective of this study was to compare CMS cotton (CMS-D2) with the cytoplasm from G. harknessii and its isogenic maintainer line with the normal fertile Upland cotton cytoplasm to identify CMS-D2 specific gene(s) and to develop CMS-specific sequence characterized amplified region (SCAR) markers. Based on Southern blot analysis using 10 mitochondrial gene-specific probes (cob, cox2, atp6, atp9, nad3, cox3, atpA, cox1, nad6 and nad9), three probes (cox3, atpA, and nad6) revealed restriction ...

UK PubMed Central (United Kingdom)

Sirt1 (member of the sirtuin family) is a nicotinamide adenosine dinucleotide (NAD)-dependent deacetylase that removes acetyl groups from various proteins. Sirt1 performs a wide variety of functions...Full Text Available

Science.gov (United States)

The frequency dependence of the lasing power of a He-Ne laser was studied using the electrooptic effect in a KDP crystal. The gain profile of the power curve was found to differ noticeably between the high-frequency and low-frequency edges. (AIP). (AIP)

International Nuclear Information System (INIS)

Cholera toxin catalyzes transfer of radiolabel from ["3"2P]NAD"+ to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and ["3"2P]NAD"+ caused radiolabeling of purified microtubule and intermediate filament proteins.

International Nuclear Information System (INIS)

It is pointed out that a recently claimed result regarding the removal of sharp structure in the electronic density of states N(E) of A-15 superconducting compounds at T approximately equal to Tsub(c) was in fact, shown earlier by one of the present authors (M.N.M.). Merely the variation of N(E) with energy in the vicinity of the Fermi level in these materials cannot explain their anomalous normal state properties and high values of lambda and Tsub(c). Rather a non-varying N(E) accompanied by phonon softening is in better agreement with experiment. (author).

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(1973). Germany Rebel, H. Schweimer, GW Kernforschungszentrum Karlsruhe

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... ECONOMICS CALIF, U-SANTA CRUZ CALIF, U-BERKELEY Ash, Marcus Alan 1425 Carlton NE , Grand Rapids MI ...

UK PubMed Central (United Kingdom)

Glucose metabolism through glycolysis and hexosamine pathway has been shown to be altered in type 2 diabetes. However, its fate through the pentose phosphate pathway (PPP) is currently unclear....Full Text Available

UK PubMed Central (United Kingdom)

Several cDNA clones encoding Δ¹-pyrroline-5-carboxylate reductase (P5CR, l-proline:NAD[P]⁺ 5-oxidoreductase, EC 1.5.1.2), which catalyzes the terminal step in...Full Text Available

International Nuclear Information System (INIS)

Male rats were injected intravenously for 15 min with physiological saline (as control) (0.05 #mu#g/kg/min) or norepinephrine (NE) (0.1 #mu#g/kg/min) followed by 740 kBq of MIBG. Rats were injected for more 30 min (early stage group) and for more 4 hr (late stage group) with physiological saline or NE. Five MBq of "9"9"mTc-tetrofosmin (TF) was administered instead of MIBG in another group. The heart was isolated and uptake of MIBG or TF of right ventricle, apex, and left ventricle (divided into 8 parts) was measured. In control group, MIBG uptake of apex was significantly lower than that of lateral wall in both early and late groups. In NE group, MIBG uptake showed a tendency to decrease in both early and late groups. Compared with control group, the uptake of anterior wall in late group decreased significantly at NE 0.1 #mu#/kg/min. The TF uptake in control group was not different in each part. In ...

International Nuclear Information System (INIS)

This study was carried out to evaluate the effects of irradiation (gamma irradiation at dose levels of 0.0, 2.5, 5.0, 10.0 or 20.0 kGy, He-Ne and their combination) on nutritive characteristics of Vicia faba L. seeds (Giza 843). Analyses included levels of anti-nutrients (total phenolic compounds, tannins, phytic acid, trypsin inhibitor and vicine), chemical composition (sugars, crude proteins, fat, dry matter and ash) and fatty acids profile. All treatments caused significant (P<0.05) decreases in the antinutrational factors under investigation. The reduction in the content of tannins and phenolic compounds were more pronounced with He-Ne alone or He-Ne in combination with gamma irradiation. At dose levels 10.0 and 20.0 kGy without or with combination of He-Ne were more efficiency in the reduction of phytic acid content by 24.3, 32.8, 34.5 and 45.5 %, respectively. Also, for trypsin inhibitor ...

Energy Technology Data Exchange (ETDEWEB)

An opportunity to study the system {sup 22}Ne+{sup 208}Pb in the proximity of the Coulomb barrier with the PRISMACLARA apparatus was given by a test of the PIAVE-ALPI accelerator in mid-December 2005. The {sup 22}Ne projectiles, having the kinetic energy of 131 MeV, collided with a {sup 208}Pb target 300 {mu}g/cm{sup 2} thick. (The beam was run for {approx}20 hours with a current of {approx}6 particle-nA). The reaction products, mainly originated by scattering or transfer processes, were detected by the PRISMA spectrometer (positioned in the proximity of the grazing angle, {approx}70 degrees), coupled to the CLARA array of germanium detectors.

International Nuclear Information System (INIS)

Time-differential magnetic moment measurements on the first-excited Isup(#pi#)=2"+ states in "2"0Ne and "2"4Mg with mean lives of 1.0 and 2.1 ps, respectively are described. The lifetime of the latter state was determined simultaneously. A special detection geometry was designed to improve the experimental #gamma#-ray anisotropy measured with finite-size detectors. For "2"0Ne also a time-integral measurement with charge-state separation was performed. The necessary electronics circuitry built to perform these complicated measurements and the plunger assembly with laser interferometer are also described. A magnetic moment measurement of "2"2Ne(2_1"+) with tau=5.0 ps and transient field measurements at low and high recoil velocities are reported. A discussion of possible extensions of the techniques are given. (Auth.).

International Nuclear Information System (INIS)

Cultures of 3T3-L1 cells were incubated with either 10 ng/ml cholera toxin or 10 ng/ml pertussis toxin from 4 days prior to the initiation of differentiation and throughout the subsequent incubation. Toxin concentrations were sufficient to completely prevent the labelling of alpha-subunits with ["3"2P]NAD"+ and pertussis toxin and to prevent by more than 90% the labelling with ["3"2P]NAD"+ and cholera toxin in membranes prepared from these cells. Neither toxin prevented the differentiation to the adipocyte phenotype. Neither toxin prevented the increases in the relative amounts of G-proteins which occur upon differentiation. Both toxins dramatically decreased the amount of beta-subunits. As measured by quantitative immunoblotting with antisera specific for both the 35 kDa and 36 kDa beta-subunits, levels of beta-subunit were decreased by more than 50% of steady-state level of control cells. Thus, bacterial toxins which modifies G-protein ...

Science.gov (United States)

Returns singular values (sigma), ;left field (x) vectors, ..... n) do begin point=ngbrs(i) if (point+tau le nt-1) then begin if (x(point+tau,0) ne q) then .... ;FILTER ;applies a gaussian filter in the frequency domain function filter, x ...

UK PubMed Central (United Kingdom)

BackgroundIn 1998, the U.K. National Health Service Information for Health Strategy proposed the implementation of a National electronic Library for Health...Full Text Available

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This monograph explores an alternative way of providing a JSOTF headquarters to the Joint Force Commander. Beginning with a history of joint SOF doctrine, the monograph outlines the evolution of special operations command and control and the subsequent ne...

Energy Technology Data Exchange (ETDEWEB)

Doubly-excited 2s{sup -1}2p{sup -1}3pnp autoionizing resonance series of Ne atom as well as autoionizing resonances in the 2s region of Na and Mg atoms have been studied with monochromatized synchrotron radiation. Use of charge-separated photoion-yield method allowed us to detect these weak resonances in a clarified way in the yield curves of doubly-charged ions. The observed resonance states have been interpreted with the help of MCDF calculations, and the decay processes of these resonance states are discussed briefly.

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When energetic heavy ions traverse a medium, the amount of energy deposited by the ions is closely related to their effective charges. The charge-state fractions of these beams are obtained by solving rate equations for the electron loss and capture processes. By assuming local balance between electron loss and capture, the charge-state distributions, the averge equilibrium charge q, and other properties are obtained as functions of the incident beam velocity. The LET (linear energy transfer) of Ne and Ar ions with energies between 0.01 and 100 MeV/amu is calculatedted using their average equilibrium charge.

International Nuclear Information System (INIS)

Spherical aggregates formed rapidly in culture by re-aggregation of trypsin-dissociated brain cells from the 17-day-old fetal rat. Over about 10 days an initially random distribution of cells evolved into a 3-layered arrangement; cells with characteristics of neurons were found largely in the intermediate layer. The survival of neuronal and glial cell types was evaluated histologically and verified by electron microscopy, which revealed synaptic and myelin structures that rapidly increased in number after 18 days in culture. Levels of norepinephrine (NE) and dopamine (DA) reached peaks of 9.5 and 4.4 ng/mg protein, respectively, at culture day 21. Uptake of ["3H]NE paralleled these amine levels and was blocked by desipramine or pretreatment with either reserpine or 6-OH-DA. Autoradiographs of aggregates labeled with ["3H]NE showed a high density of silver grains over cells, apparently neurons, with branching processes ...

CERN Document Server

We present our discovery of a narrow-line Baldwin effect, an anti-correlation between the equivalent width (EW) of a line and the flux of the associated continuum, in 5-20$\\mu$m mid-infared lines from a sample of 68 Active Galactic Nuclei (AGN), located at z$<$0.5, observed with the Infrared Spectrograph on the {\\it Spitzer Space Telescope}. Our analysis reveals a clear anti-correlation between the EW of the [SIV] 10.51$\\mu$m, [NeII] 12.81$\\mu$m, and [NeIII] 15.56$\\mu$m lines and their mid-IR continuum luminosities, while the Baldwin effect for [NeV] 14.32$\\mu$m is not as obvious. We suggest that this anti-correlation is driven by the central AGN and not circumnuclear star formation in the host galaxy. We also find that the slope of the narrow-line Baldwin effect in the mid-infrared does not appear to steepen with increasing ionization potential. Examining the dependence of the EW to the Eddington Ratio ...

International Nuclear Information System (INIS)

As part of the 1999 NARSTO Northeast Oxidant and Particulate Study (NE-OPS) field campaign, the DOE G-1 aircraft sampled trace gases and aerosols in and around the Philadelphia metropolitan area. Twenty research flights were conducted between July 25 and August 11. The overall goals of these flights were to obtain a mechanistic understanding of O(sub 3) production; to characterize the spatial and temporal behavior of photo-oxidants and aerosols; and to study the evolution of aerosol size distributions, including the process of new particle formation. Within the NE-OPS program, other groups provided additional trace gas, aerosol, and meteorological observations using aircraft, balloon, remote sensing, and surface based instruments (Phillbrick et al., 2000). In this article we provide an overview of the G-1 observations related to O(sub 3) production, focusing on the vertical distribution of pollutants. Ozone production rates are calculated using ...

CERN Document Server

The basic theoretical milestones were the Sakata SU(3) symmetry, the Goldberg-Ne'eman composite model with SU(3) triplets having baryon number (1/3) and the Nambu color gauge Lagrangian. The transition was led in right and wrong directions by experiments interpreted by phenomenology. A "good" experiment on $\\bar p p$ annihilation at rest showed that the Sakata model predictions disagreed with experiment. A "bad" experiment prevented the use of the Goldberg-Ne'eman triplet model to predict the existence and masses of the of the $\\Xi^*$ and $\\Omega^-$. More "good" experiments revealed the existence and mass of the $\\Xi^*$ and the $\\Omega^-$ and the absence of positive strangeness baryon resonances, thus confirming the "tenfold way". Further "good experiments" revealed the existence of the vector meson nonet, SU(3) breaking with singlet-octet mixing and the suppression of the $\\phi \\to \\rho \\pi$ decay. These led to the quark triplet ...

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We have determined the actual RNA sequence of four mitochondrial genes: pcf, nad3, rps12, and coxII. Because plant mitochondrial proteins cannot be predicted from DNA sequences, the actual primary structures of the encoded proteins were unknown. We have gained information concerning the process of RNA editing. Editing can occur before splicing. Our data is consistent with the hypothesis that RNA editing is not simultaneous with transcription. Unlike other systems, the process of editing in plant does not exhibit a discernable direction. As a result of our RNA editing studies, we have produced a number of clones of the proper coding regions tube used for incorporating these mitochondrial genes into the nucleus. 6 refs., 4 figs.

International Nuclear Information System (INIS)

The responses of ramets of hybrid poplar (Populus spp.) (HP) clones NE388 and NE359, and seedlings of red maple (Acer rubrum, L.) to ambient ozone (O_3) were studied during May-September of 2000 and 2001 under natural forest conditions and differing natural sunlight exposures (sun, partial shade and full shade). Ambient O_3 concentrations at the study site reached hourly peaks of 109 and 98 ppb in 2000 and 2001, respectively. Monthly 12-h average O_3 concentrations ranged from 32.3 to 52.9 ppb. Weekly 12-h average photosynthetically active radiation (PAR) within the sun, partial shade and full shade plots ranged from 200 to 750, 50 to 180, and 25 to 75 #mu#mol m"-"2 s"-"1, respectively. Ambient O_3 exposure induced visible foliar symptoms on HP NE388 and NE359 in both growing seasons, with more severe injury observed on NE388 than on NE359. Slight foliar ...

CERN Document Server

A new constraint of clustering for the AMD calculation is proposed. This new constraint gives us large improvement in studying the cluster structure by AMD which sometimes meets difficulty in giving rise to some specific cluster configurations. The usefulness of this new constraint is verified by applying it to the the study of the third $K^\\pi = 0^+$ band of $^{20}$Ne which has been discussed to have $2\\alpha$-$^{12}$C structure. This band has not been easy even to construct by AMD. We see that the AMD+GCM calculation by the use of the new constraint gives rise to the third $K^\\pi = 0^+$ band which contains the $2\\alpha$-$^{12}$C structure as an important component.

International Nuclear Information System (INIS)

Shadow effect was used for investigating damage of uranium dioxide monocrystal. The dependence of shadow minimum parameters on fluence of "2"2Ne ions with 172 MeV energy was followed when detecting fission fragments. Ion dose responsible for sufficient microdamage of lattice structure, included into the classification of heavy ion damage effect on monocrystals was determined. The problem of radiation intensity effect on the character of occurred damages was studied. It was established that macroscopic sample failure, caused by generation of considerable mechanical stresses in monocrystal under beam effect could be observed along with microdamages of lattice structure at ion flux density >10"1"2 cm"-"2Xs"-"1.

Science.gov (United States)

Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) are tryptophan-degrading enzymes. Mammalian IDO expression is induced by cytokines and has antimicrobial and immunomodulatory effects. A major role of mammalian TDO is to supply nicotinamide adenine dinucleotide (NAD(+)). In fungi, the IDO homologue is thought to be expressed constitutively and supply NAD(+), as TDO is absent from their genomes. Here, we reveal the distribution of IDO genes among fungal species and characterize their enzymatic activity. The yeast, Saccharomyces cerevisiae has only one IDO gene, whereas the koji-mold, Aspergillus oryzae has two genes, IDO? and IDO?. The A. oryzae IDO? showed more similar enzymatic properties to those of S. cerevisiae IDO than IDO?, suggesting that the A. oryzae IDO? is a functional homologue of the S. cerevisiae IDO. From the IDO? gene, two isoforms, IDO? and IDO?(+) could be generated by alternative splicing. The latter ...

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Report on status of program to raise awareness and heighten interest in nuclear engineering and nuclear science, particularly among 7th through 12th grade students and pre-college freshmen.

International Nuclear Information System (INIS)

Motivated by the strong discrepancy between the main-sequence turnoff age and the white dwarf cooling age in the metal-rich open cluster NGC 6791, we compute a grid of white dwarf evolutionary sequences that incorporates for the first time the energy released by the processes of "2"2Ne sedimentation and of carbon/oxygen phase separation upon crystallization. The grid covers the mass range from 0.52 to 1.0 M _s_u_n, and is appropriate for the study of white dwarfs in metal-rich clusters. The evolutionary calculations are based on a detailed and self-consistent treatment of the energy released from these two processes, as well as on the employment of realistic carbon/oxygen profiles, of relevance for an accurate evaluation of the energy released by carbon/oxygen phase separation. We find that "2"2Ne sedimentation strongly delays the cooling rate of white dwarfs stemming from progenitors with high metallicities at moderate luminosities, while ...

Science.gov (United States)

In this study, the complete sequence of the mitochondrial DNA (mtDNA) of Atelura formicaria (Hexapoda: Zygentoma) is described. The molecule is 15.205 bp in length and it is the third complete mt genome sequenced from the Zygentoma. The genome organization conforms with the putative ancestral insect gene arrangement. All protein coding genes use standard initiation codons (methionine and isoleucine). The exception is nad4 that starts with GTG, a codon used for this purpose in other insect species. A peculiar strand skew bias is observed, given that the PCGs encoded on the J-strand contain more thymines than adenines and more cytosines than guanines. This trend in nucleotide composition has been observed also in the "firebrat" Thermobia domestica (Zygentoma, Lepismatidae), but differs from that of the majority of hexapod species, including Tricholepidion gertschi (Zygentoma, Lepidotrichidae), where adenines and cytosines outnumber thymines and guanines. The presence ...

International Nuclear Information System (INIS)

The performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS was investigated using 255No produced in the 238U(22Ne, 5n)255No reaction. Alpha particles of 255No separated with GARIS and transported by the gas-jet system were measured with a rotating wheel apparatus for ? spectrometry under low background condition. The high gas-jet efficiencies of about 75% were independent of the recoil ranges of 255No in the gas-jet chamber. The present results suggest that the GARIS/gas-jet system is a promising tool for the next-generation superheavy element chemistry: (1) the background radioactivities of unwanted reaction products are strongly suppressed, (2) the intense beam is absent in the gas-jet chamber and hence the high gas-jet efficiency is achieved, and (3) the beam-free condition also allows for investigations of new chemical systems. (author)

CERN Document Server

We present a theoretical framework for formal study of systematic effects in Supernovae Type Ia (SN Ia) that utilizes 2-d simulations to implement a form of the deflagration-detonation transition (DDT) explosion scenario. The framework is developed from a randomized initial condition that leads to a sample of simulated SN Ia whose Ni56 masses have a similar average and range to those observed, and have many other modestly realistic features such as the velocity extent of intermediate mass elements. The intended purpose is to enable statistically well-defined studies of both physical and theoretical parameters of the SN Ia explosion simulation. We present here a thorough description of the outcome of the SN Ia explosions produced by our current simulations. A first application of this framework is utilized to study the dependence of the SN Ia on the Ne22 content, which is known to be directly influenced by the progenitor stellar population's metallicity. Our study ...

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We calculate the exclusion region in the parameter space of {nu}{sub {mu}} {yields} {nu}{sub e} oscillations of the LSND type using a combined fit to the reconstructed energy distributions of neutrino candidate samples from the MiniBooNE data obtained with two different particle identification methods. The two {nu}{sub e} candidate samples are included together with a high statistics sample of {nu}{sub {mu}} events in the definition of a {chi}{sup 2} statistic which includes the correlations between the energy intervals of all three samples and handles the event overlap between the {nu}{sub e} samples. The {nu}{sub {mu}} sample is introduced to constrain the effect of systematic uncertainties. This analysis increases the exclusion limit in the region {Delta}m{sup 2} {approx}< 1eV{sup 2} when compared with the result previously published by the collaboration, which used a different technique.

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The isotopic enrichment of copper ions in a positive column Cu-Nu discharge using optogalvanic excitation is analyzed with a rate equation model With excitation at 510.6 nm, the fraction of the ions belonging to the 63-amu isotope of copper is enriched relative to the neutral abundance. Enrichment as large as 10% is calculated when the initial abundance of the neutral isotope is small (< or =0.1) and the discharge current density is large (> or =75 mA/cm/sup 2/). The degree of enrichment is examined as a function of the initial abundance, discharge current, the rate of charge exchange, and the diameter of the discharge tube.

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Building complex knowledge based applications requires encoding large amounts of domain knowledge. After acquiring knowledge from domain experts, much of the effort in building a knowledge base goes into verifying that the knowledge is encoded correctly. We consider the problem of verifying hybrid knowledge bases that contain both Horn rules and a terminology in a description logic. Our approach to the verification problem is based on showing a close relationship to the problem of query containment. Our first contribution, based on this relationship, is presenting a thorough analysis of the decidability and complexity of the verification problem, for knowledge bases containing recursive rules and the interpreted predicates =, {le}, < and {ne}. Second, we show that important new classes of constraints on correct inputs and outputs can be expressed in a hybrid setting, in which a description logic class hierarchy is also considered, and we present the first ...

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As the ground state potential curve is strongly related to spectral line shapes, the minumum position of the ground state potential is obtained from the experiemental absorption profile k({delta}{nu}, T) at high density of the radiating atoms. The temperature dependence of the absorption processes of Hg and Cd lines 253.65 and 326.1 nm, respectively perturbed by inert gases (Xe, Kr, Ar and Ne) had been carefully studied over a wide spectral range. Using the point of the maximum temperature dependence {delta}{nu} {sub m} in each case, we are able to calculate the position of the ground state potential R {sub m} using a simple formula.

British Library Electronic Table of Contents (United Kingdom)

The 10th International Neurotrauma Symposium was held in Shanghai, China, on 27-???30 April 2011. This meeting marked the 20th anniversary of International Neurotrauma Symposia. The vision of the International Neurotrauma Society is to unite clinicians and scientists to discuss and present the latest in translational clinical and basic science research related to neurotrauma. The Shanghai meeting brought together 1000 delegates from over 70 countries. Key areas discussed included current guidelines of neurotrauma management, the latest advances in neuroimaging, the latest concepts in cell death mechanisms after neurotrauma, the role of decompressive techniques for cranial and spinal neurotrauma, advances in biomarkers for CNS injury, and the future of clinical management and research in ne...

British Library Electronic Table of Contents (United Kingdom)

This study was developed as part of the project ?Studies for Environmental and Cultural Sustainability of the Fulni-? Medical System: Office on handling medicinal plants?. The Fulni-? people are located in Pernambuco State, Northeastern Brazil. One of the components of this project was an ethnobotanical diagnosis of the indigenous land, where a phytosociological survey was performed in an area of Caatinga vegetation, located at Ouricuri settlement. Based on these ethnobotanical data, we calculated a conservation priority index aiming to rank species that should receive immediate attention from the Fulni-? people. We identified 44 woody plants, 50% of which have a medicinal use. Among these, six plants were considered highly vulnerable and in need of immediate conservationist attention, in ...

CERN Document Server

We discuss the minimum requirements for a neutrino beta beam if theta_13 is discovered by an upcoming reactor experiment, such as Double Chooz or Daya Bay. We require that both neutrino mass hierarchy and leptonic CP violation can be measured to competitive precisions with a single-baseline experiment in the entire remaining theta_13 range. We find that for very high isotope production rates, such as they might be possible using a production ring, a (B,Li) beta beam with a gamma as low as 60 could already be sufficient to perform all of these measurements. If only the often used nominal source luminosities can be achieved, for example, a (Ne,He) beta beam from Fermilab to a possibly existing water Cherenkov detector at Homestake with gamma \\sim 190-350 (depending on the Double Chooz best-fit) could outperform practically any other beam technology including wide-band beam and neutrino factory.

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This BCRS project demonstrates the use of SAR interferometry for measuring and monitoring land subsidence caused by underground coal fires and underground mining in a remote area of north west China. China is the largest producer and consumer of coal in the world. Throughout the N.W., N. and N.E. of China, the coal-seams are very susceptible to spontaneous combustion, causing underground coal fires. As the thick coal seams are burned out, the overburden collapses, causing land subsidence, and producing new cracks and fissures, which allow more air to penetrate and continue the fire to spread. SAR interferometry, especially differential interferometry has been shown to be able to measure small differences in surface height caused by such land subsidence. This report describes the problems, the test area, the procedures and techniques used and the results obtained. It concludes with a description of some of the problems encountered during the project plus provides ...

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The developed system is intended for use at a collimated thermal neutron beam with a flux of about 10{sup 6} n/cm{sup 2} s. The system works with a cooled CCD array (192 x 165 pixels) and an intensifier for light from a NE426 scintillator with traditional optical coupling. A fine mechanical regulation system allows an accurate positioning of the tomographer, also ensuring the alignment of the CCD array with the rotation and translation axes. The acquisition of 200 projections is carried out in about 30 min with a reconstruction time (40 min max) depending on the reconstruction-matrix order. Radiography and tomography of significant objects are illustrated. The reconstruction algorithm, including spatial and temporal inhomogeneity corrections and filters, was tested with good results for projections up to 512 x 512 pixels. (orig.)

International Nuclear Information System (INIS)

At Cazzaso (Friuli) in northeast Italy, radon ("2"2"2Rn) activity concentration in soil gas in a borehole at a depth of 80 cm has been monitored continuously (at a frequency of once an hour) since May 2004, using a Barasol probe (Algade, France). In addition, environmental parameters (air and soil temperature, barometric pressure) have been recorded. The results have been evaluated and the relationship between radon levels and seismic activity is discussed. Correlation between radon concentration and barometric pressure has been observed. Preliminary results have shown a distinct radon anomaly prior to some earthquakes. (authors)

British Library Electronic Table of Contents (United Kingdom)

This paper provides both a detailed history of environmental change in the Sierra Nevada over the past 1,800?years and evidence for climate teleconnections between the Sierra Nevada and Greenland during the late Holocene. A review of Greenland ice core data suggests that the magnitudes of abrupt changes in temperature and precipitation increased beginning c. 3,700 and 3,000?years ago, respectively. Precipitation increased abruptly 1,300?years ago. Comparing paleotemperature data from Cirque Peak, CA with paleoprecipitation data from Pyramid Lake, NV suggests that hot temperatures occurred at the beginnings of most severe droughts in the Sierra Nevada over the past 1,800?years. Severe fires and erosion also occurred at Coburn Lake, CA at the beginning of all severe droughts in the Sierra Ne...

International Nuclear Information System (INIS)

Effect of helium and hydrogen production on radiation-hardening of F82H irradiated by dual or triple beam condition were investigated. The specimens used were four types of ferritic martensitic steels of F82H-std (Fe-8Cr-2W-0.2V-0.04Ta-0.1C) steels tempered at 750degC for 60 minutes, 20% cold worked F82H steel, F82H tempered for 10 minutes and non-tempered F82H steels. The irradiation was performed at 450degC to 50 dpa under simultaneous dual beams of 10.5 MeV Fe"3"+ and 1.05 MeV He"+ or triple beams of those and 380 keV H"+ ions. The ratios of He (appm)/dpa and H(appm)/dpa were 15 nad 15 (or 150) for dual and triple ion beams. The hardness of the irradiated specimens measured at room temperature using a micro indentation after the irradiations. The hardness in these F82H steels irradiated at 450degC to 18 dpa under triple beam irradiation was harder than that under dual beam irradiation. Irradiation softening and hardening under dual beams was observed in F82H ...

Energy Technology Data Exchange (ETDEWEB)

This study attempts to elucidate some of the effects of adding argon, neon and hydrogen to low pressure thermionically supported discharges used for plasma nitriding AISI M2 steel substrates. Four runs were performed at the same substrate temperature (550 C) and bias voltage (500 V), using the following gas mixtures: 8% N{sub 2} in Ar, 8% N{sub 2} in Ne, N{sub 2}+H{sub 2} in equal proportions, and N{sub 2} only. By careful control of the discharge parameters, most of the bombardment energy was transported to the substrates by 500 eV ions in all cases; these were mainly Ar{sup +} ions in the N{sub 2}+Ar run and N{sub 2}{sup +} ions in the other runs, notably by the action of Penning ionization in the N{sub 2}+Ne run. We found that the surface hardness was not significantly influenced by the type of ion delivering the bombardment energy, although we suggest that ions would need sufficient mass to cause (for example) sputtering, if the substrate ...

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A real-time neutron radiography imaging system has been installed at the Texas A and M University Nuclear Science Center. The system employs a scintillating screen viewed by a low-light TV camera with a front surface mirror placed at 45deg to the neutron beam. The key components of the system are the neutron camera and the image capture and processing unit. The neutron camera uses an NE 426 scintillating screen (ZnS), front surface mirror, remote focus and zoom lens, intensified relay optics (IRO) and monochrome CCD television camera. The image capture and processing unit consists of an IBM PC AT-compatible computer, arithmetic frame grabber, frame processor and high-resolution color monitor. The neutron camera is similar to others using a silicon intensified target (SIT) television camera to provide a TV image of the low-level light from a NE 426 screen. The IRO and CCD camera are used in place of the SIT camera. The computer digitizes the TV ...

Energy Technology Data Exchange (ETDEWEB)

The energy-integrated reaction cross-sections of several neutron-rich nuclei ({sup 17-22}N, {sup 19-24}O, {sup 21-27}F, {sup 23-30}Ne, {sup 26-33}Na, {sup 28-35}Mg, {sup 31-38}Al, {sup 33-40}Si, {sup 36-42}P, {sup 39-44}S, {sup 42-45}Cl, {sup 45,46}Ar), measured at intermediate energy (30-65 A-bar MeV), via direct method, are presented. Silicon detectors have been used as the active target as well as for particles identification. The reduced strong absorption radii r{sub 0}{sup 2} are extracted and compared to the data available from the literature. New measurements for 19 nuclei ({sup 27}F, {sup 27,30}Ne, {sup 33}Na, {sup 28,34-35}Mg, {sup 36-38}Al, {sup 38-40}Si, {sup 41-42}P, {sup 42-44}S, {sup 45}Cl) are revealed. From the study of the isospin dependence of the reduced strong absorption radius, a new quadratic parameterisation of the nuclear radii in the closed shell regions N=8 and N=28, is proposed. According to this parameterisation, the ...

Energy Technology Data Exchange (ETDEWEB)

Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne{endash}H{sub 2} mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne{endash}H{sub 2} potentials of Lennard{endash}Jones (LJ) type show that excess volumes are very sensitive to the ...

International Nuclear Information System (INIS)

Gabal Ralal is one of the major asymmetrical doubly- plunging anticlinal fold belts (50 Km length) related to the Syrian Arc System in northern Sinai, Egypt. The exposed rock units at Gabal Ralal range from Cretaceous to Quaternary and are divided into eight formations which are from base to top: Malha, Ralal, Wata, Themed, Sudr, Beida, Egma and Quaternary wadi deposits. The image processing is applied using Landsat-7 satellite data to discriminate structure and lithology for defining the horizons of the radioactive anomalies of each rock unit. The extracted structural lineaments, using Ge Analyst-PCl package, from digital ETM data showed that the main structural trends are NE-SW and NW-SE normal faults which originated as extensional fractures with lateral dip-slip displacement. The axial trace of Gabal Ralal fold is curved and plunging to Wand SW directions while the northeastern part (Gabal Dalfa) is plunging to NE direction. The use of ...

Energy Technology Data Exchange (ETDEWEB)

A laser resonance absorption spectrometer is used to investigate the characteristics of both self and nitrogen collision broadened carbon dioxide in resonance with He--Ne laser radiation at 4.2 ..mu..m. The absorption coefficient in these broadening conditions has contributions from the R(28) to R(34) absorption lines of the ..nu../sub 3/ CO/sub 2/ spectrum. The Fletcher-Powell optimization method is used to reduce the raw absorption data and to find the best value average collision broadening coefficient and laser emission frequency for a Lorentzian line shape model of the contributing lines. Pure carbon dioxide absorption in a pressure range of from 0.0016 atm (1.25 Torr) to 0.33 atm (250 Torr) is described well by the model with an average self broadening coefficient of 0.084 +- 0.008 cm/sup -1/ atm/sup -1/ for laser frequencies located at either 2370.591 +- 0.020 cm/sup -1/ or 2371.135 +- 0.019 cm/sup -1/. Nitrogen broadened carbon dioxide in the total pressure ...

Energy Technology Data Exchange (ETDEWEB)

Neutron and gamma ray energy spectra were measured using an NE-213 scintillator at depths of 7.2, 15.2, and 22.2 cm in a tissue-equivalent phantom which was uniformly irradiated on one face by deuterium--tritium (DT) neutrons. Coupled neutron--gamma ray multigroup discrete-ordinates calculations were performed using semi-infinite slab geometry. These calculations were used to supplement the measured spectra below 1 MeV. Similar calculations were performed to study the perturbation in the phantom due to the detector. The measured and calculated spectra were used to determine the kerma distributions for neutrons and gamma rays at each location. The gamma radiation was determined to contribute more than 10% of the total dose at each depth. The calculated kerma also reveals that a knowledge of the gamma ray spectra below 1 MeV is desirable. Key words: neutron--gamma spectra, spectrometry, kerma distributions, coupled multigroup calculations

CERN Document Server

We demonstrate that a massive asymptotic giant branch (AGB) star is a good candidate as the main source of short-lived radionuclides in the early solar system. Recent identification of massive (4-8 solar masses) AGB stars in the Galaxy, which are both lithium- and rubidium-rich, demonstrates that these stars experience proton captures at the base of the convective envelope (hot bottom burning), together with high-neutron density nucleosynthesis with 22Ne as a neutron source in the He shell and efficient dredge-up of the processed material. A model of a 6.5 solar masses star of solar metallicity can simultaneously match the abundances of 26Al, 41Ca, 60Fe, and 107Pd inferred to have been present in the solar nebula by using a dilution factor of 1 part of AGB material per 300 parts of original solar nebula material, and taking into account a time interval between injection of the short-lived nuclides and consolidation of the first meteorites equal to 0.53 Myr. Such a ...

International Nuclear Information System (INIS)

The T/sub c/ behavior of vapor-deposited Nb_3Ge and Nb_3Sn is examined as a function of low-fluence alpha-particle irradiation. It is found that for Nb_3Sn with rho_0approx.15 #mu##OMEGA#-cm the T/sub c/ is insensitive to low doses of radiation, whereas Nb_3Ge with rho_0approx.50 #mu##OMEGA#-cm has its T/sub c/ depressed immediately with irradiation. It is suggested that the T/sub c/ behavior of A-15 superconductors in the regime of small dose is strongly influenced by the initial state of the sample. Furthermore, it is argued that the behavior of the T/sub c/ with dose can be qualitatively explained by considering a sharp structure in the density of states N(E), the smearing of which by defects leads to a depression in T/sub c/.

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Diffusion during He/sup +/, Ne/sup +/, and Xe/sup +/ irradiations of trace amounts of Au in melt-spun amorphous Pd/sub 78/Cu/sub 6/Si/sub 16/ has been experimentally investigated. Diffusion constants were measured by following the changes in ion-implanted Au profiles with Rutherford-backscattering spectrometry. Heat treatments and simultaneous irradiations were performed as a function of temperature (533--588 K), ion flux, and ion mass. Total integrated fluences being very small, ion-beam-mixing effects are negligible. More than an order of magnitude enhancement in the diffusion was observed because of irradiations. This enhancement saturates at higher fluxes, the level being independent of ion mass, i.e., independent of collision-cascade parameters. Except at higher temperatures, where the enhancement decreases, the temperature dependence of the diffusion-saturation level is similar to that of the diffusion without irradiation. The data suggest that vacancylike ...

Science.gov (United States)

The design and parameters of a UV-VUV spontaneous radiation source - an excilamp operating on chlorides of rare gases ArCl{sup *}, KrCl{sup *} and XeCl{sup *} in the wavelength range 175-308 nm are presented. The Ne-Xe(Kr, Ar)-HCl mixtures were excited by a high-pressure self-sustained discharge with spark preionisation. It is shown that upon pumping mixtures of rare gases and halogens by a transverse discharge, the intensities of the B-X emission band of molecules ArCl{sup *}, KrCl{sup *} and XeCl{sup *} are comparable and up to 90% of the emission energy of excilamps can be concentrated in the UV region. The peak UV power density at 222 and 308 nm on the output window of the excilamp was {approx}2 kW cm{sup -2} for the pulse energy up to {approx} 3 mJ. The output emission energy of the excilamp at 175 nm achieved {approx}0.6 mJ and the peak power density was {approx}0.4 kW cm{sup -2}. (laser applications and other topics in quantum electronics)

International Nuclear Information System (INIS)

In neutron radiography, as in other forms of NDE, it is sometimes desirable to observe dynamic events. This need has generated increased interest in the development of real-time neutron radiography systems and neutron-to-light converter screens optimized for real-time application. Two screens currently available at MURR are: (1) a 0.041-cm-thick Gd_2O_2S screen manufactured by 3M Company and (2) a "6KiF-ZnS(Ag) screen (NE 426) manufactured by Nuclear Enterprises. These screens are presently used in conventional film neutron radiography and represent two of the commercially available screens that have demonstrated the greatest resolution and sensitivity. Unfortunately, these screens have severe limitations when used for real-time neutron radiography. In order to isolate and minimize the factors contributing to these limitations, several neutron absorbers and phosphorus were studied at MURR. The screen thickness and the neutron absorber/phosphorus weight ratio was ...

Environmental Research Database

ObjectivesThe main objectives of this project are: 1. To determine whether nest-drifting behaviour allows helpers to maximise their indirect fitness in the paper wasp Polistes canadensis. Specifically, I will test a) whether nest-drifters apportion helping effort in relation to the productivity benefits of different nests (hypothesis 1a), and b) whether nest-drifters can adjust their investment in response to changes in the productivity payoffs of different nests (hypothesis 1b). 2. To determine [continued...]DescriptionDarwin's theory of natural selection predicts that organisms should act selfishly in order to pass on as many of their genes to the next generation as possible. The evolution of social behaviour is a paradox because it requires that some individuals forgo reproduction in order to help raise the offspring of others. Explaining the evolution of helping behaviour in animal societies has been a major focus for evolutionary biologists ever since Darwin. A leading explanation ...

International Nuclear Information System (INIS)

Focused ion beam (FIB) processes have been developed for Y--Ba--Cu--O superconductor films. A Y--Cu liquid metal ion source has been fabricated, using a Y_6_7 --Cu_3_3 eutectic alloy as the ion source. As-sputtered Y--Ba--Cu--O film etch rate ratios to GaAs(100) and Si(100) substrates are 0.28 and 1.4 for 130-keV Au"+ FIB ion etching, respectively. Y--Ba--Cu--O submicron patterns have been demonstrated by using FIB lithography and Cl_2 reactive ion beam etching. Moreover, a Y--Ba--Cu--O superconducting line with 4-#mu#m linewidth has been fabricated by annealing an as-sputtered Y--Ba--Cu--O line pattern. T/sub c/ control of Y--Ba--Cu--O film has been achieved by 200-keV Ne"+, using conventional ion implantation and 300 keV Si"+"+ FIB ion implantation.

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to compare the techniques and results obtained when a general industrial or commercial building power electrical system is prepared using the US National Electrical Code{copyright} (NEC) and the International Electrotechnical Commission (IEC) Standards. The final design offer the reader the possibility of making an initial comparison and analyzation of the two methods based of their overall effectiveness (sizing, protection, co-ordination of protective devices with components etc.), safety and cost. In order to make such a comparison a specific example was developed and limited in detail to avoid complexity in this study. The power source selected will be a delta-wye utility supplied transformer feeding various load groups such as lighting and motor circuits (possibly through associated transformers). Relevant NE Code references, IEC standards, and appropriate justifications will be made at various points. Since this paper is for ...

International Nuclear Information System (INIS)

The purpose of this text is to train engineers and technologists not just to understand corrosion but to control it. Materials selection, coatings, chemical inhibitors, cathodic and anodic protection, and equipment design are covered in separate chapters. High-temperature oxidation is discussed in the final two chapters ne on oxidation theory and one on controlling oxidation by alloying and with coatings. This book treats corrosion and high-temperature oxidation separately. Corrosion is divided into three groups: (1) chemical dissolution including uniform attack, (2) electrochemical corrosion from either metallurgical or environmental cells, and (3) stress-assisted corrosion. Corrosion is logically grouped according to mechanisms rather than arbitrarily separated into different types of corrosion as if they were unrelated. For those university students and industry personnel who approach corrosion theory very hesitantly, this text will present the electrochemical ...

International Nuclear Information System (INIS)

An energy analyzer has been constructed and operated in UHV for the purpose of analyzing the energy of neutral atoms scattered from solid surfaces. The analyzer consists of a LiF single crystal located at an angle close to the normal to the sample crystal so that the diffraction pattern obtained by scanning the LiF crystal yields the energy of the scattered atoms. Two designs which have been used are described. The temperature of both sample and analyzer crystal is near 20 K and once cleaned they can be maintained in the state of initial preparation for many weeks. The sample was a (001) Cu surface in this case. Such an energy analyzer can only be used, in most cases, for He atom scattering although Ne atoms could be used if the scattered intensities were adequate. The detector developed in this study is able to detect about 2 x 10"5 atoms/s. The resolution of the spectrometer depends on the incident energy of the atom and is about 1 meV at an incident energy of 23 ...

Energy Technology Data Exchange (ETDEWEB)

The cross sections for /sup 250/Fm, /sup 244-246/Cf, /sup 242-244/Cm, and /sup 242/Am/sup g-italic/ produced by the /sup 12/C+ /sup 242/Pu and the /sup 16/O+ /sup 238/U reactions leading to the same compound nucleus of /sup 254/Fm have been measured by using radiochemical methods. The excitation functions show that the difference between the /sup 12/C+ /sup 242/Pu and the /sup 16/O+ /sup 238/U reactions can be attributed mainly to the Coulomb barriers. Our results were compared with others reported previously for /sup 22/Ne+ /sup 232/Th, /sup 12/C+ /sup 238/U, /sup 12/C+ /sup 240,241/Pu, /sup 13/C+ /sup 241/Pu, /sup 16/O+ /sup 233/U, and /sup 16/O+ /sup 242/Pu reaction systems, and support a mechanism involving transfer of ..cap alpha..-particle clusters (C,Be,He) from projectile to target for the production of Cf and Cm isotopes.

International Nuclear Information System (INIS)

This paper reports measurements of absolute differential cross sections for the direct scattering of oxygen atoms by He, Ne, Ar, Kr, Xe, H_2, N_2, O_2, CO, CO_2, H_2O, SO_2, NH_3, CH_4, CF_4, and SF_6 targets. The measured cross sections include contributions from all elastic and inelastic processes that result in a fast neutral oxygen atom product. Cross sections are presented for 0.5- and 1.5-keV projectile energies over the laboratory angular range 0.2 degree endash 5 degree. When compared in the center-of-mass reference frame, these cross sections exhibit a high degree of similarity in both amplitude and angular dependence. The cross sections for N_2, CO, CO_2, and H_2O are inverted using a partial-wave analysis to yield empirical interaction potentials, which can then be used to extrapolate the measurements down to lower energies. Using these potentials, cross sections are evaluated at 0.1 keV. copyright 1996 The American Physical Society.

Energy Technology Data Exchange (ETDEWEB)

Palmer Drought Severity Index (PDSI) monthly data are analyzed, building on a previous study that investigated the influence of the El Nino/Southern Oscillation (ENSO) on US streamflow. Harmonic analysis is performed using data from 1,035 selected climatological stations, allowing observation of the biennial tendency in climate data. With the middle twelve months defined as the El Nino year (0), an idealized first harmonic fit to a 24-month ENSO composite is computed for each station. By plotting the first harmonic vectors of each station, regions of similar, or coherent, response are identified. The regions identified using PDSI data represent wet conditions in the Gulf of Mexico (Gm1 and GM2) and central (C) US, and dry conditions in the Pacific northwest (PNW) and northeast (NE) US. The PNW region exhibits the strongest interrelationship between ENSO and extreme drought events. Comparing PDSI data results with other hydroclimatic data (temperature, ...

Energy Technology Data Exchange (ETDEWEB)

This thesis presents the study of the slowing down process of fast heavy ions inside matter. In the framework of this research, the influence of the target density on the stopping process is investigated. Experiments on the interaction of {sup 48}Ca{sup 6+}-{sup 48}Ca{sup 10+} and {sup 26}Mg{sup 5+} ion beams with initial energies of 11.4 MeV/u and 5.9 MeV/u with solid and gaseous targets have been carried out. A novel diagnostic method, X-ray spectroscopy of K-shell projectile radiation, is used to determine the ion charge state in relation to its velocity during the penetration of fast heavy ions inside the stopping material. A spatially resolved analysis of the projectile and target radiation in solids is achieved for the first time. The application of low-density silica aerogels as stopping media provided a stretching of the ion stopping length by 20 - 100 times in comparison with solid quartz. The Doppler Effect observed on the projectile K-shell spectra is used to calculate the ...

Energy Technology Data Exchange (ETDEWEB)

The island of Hispaniola (Dominican Republic and Haiti) lies within the North Caribbean strike-slip plate boundary zone. The post-Eocene history of Hispaniola is marked by strike-slip accretion of crustal fragments onto a Late Cretaceous-Eocene island arc. Three onshore Neogene clastic basins have been the focus of petroleum exploration in Hispaniola. Oil production was achieved by drilling surface anticlines in the Azua Basin in South-Central Hispaniola (Dominican Republic) during World War II (Maleno and Higuerito fields). More modern seismic exploration has been carried out in the Enriquillo, San Juan and Cibao Basins, but has not resulted in production. Recent surface and seismic stratigraphic mapping has elucidated the geologic history of Southern Hispaniola. It consists of several Late Cretaceous-Eocene oceanic and island-arc terranes separated by E-W to NW/SE-striking ''ramp'' or thrust-bound clastic basins of Neogene age (San Juan, Azua and ...

International Nuclear Information System (INIS)

Prior to this study, almost no up-to-date information was available on the 'background' level of "1"4C present in the water and biota of the UK coastal marine environment. The weighted mean "1"4C activity derived from the lowest activities of dissolved inorganic carbon (DIC) and biota for sites which are remote from potential sources is 247#centre dot#6#+-#1#centre dot#0 Bq kg"-"1 carbon. This is proposed as the best estimate of the natural/weapons testing 'background' for 1995 and should be subtracted from the activity derived for any sample to establish the excess due to UK anthropogenic inputs. "1"4C activities in the DIC component of seawater and a range of marine biota are significantly enhanced above the expected 'background' value in the environment around the British Nuclear Fuels plc reprocessing plant at Sellafield, Cumbria, NW England and Amersham International plc, Cardiff, Wales. The enrichments around Sellafield are largely confined to the NE Irish ...

International Nuclear Information System (INIS)

We present a collisional-radiative approach of the theoretical analysis of laser-induced breakdown spectroscopy (LIBS) plasmas. This model, which relies on an optimized effective potential atomic structure code, was used to simulate a pure aluminum plasma. The description of aluminum involved a set of 220 atomic levels representative of three different stages of ionization (Al0, Al+ and Al++). The calculations were carried for stationary plasmas, with input parameters (ne and Te) ranging respectively between 1013-18 cm-3 and 0.3-2 eV. A comparison of our atomic data with some existing databases is made. The code was mainly developed to address the validity of the local thermodynamic equilibrium (LTE) assumption. For usual LIBS plasma parameters, we did not reveal a sizeable discrepancy of the radiative equilibrium of the plasma towards LTE. For cases where LTE was firmly believed to stand, the Boltzmann plot outputs of this code were used to check the physical ...

Energy Technology Data Exchange (ETDEWEB)

Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/..gamma.. ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time ..gamma.. spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded ..gamma.. spectra created by the photopeak-Compton edge combination in the plateau portion of the knee response, correcting equations using a linearized approximation to the ...

Science.gov (United States)

Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/gamma ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time gamma spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded gamma spectra created by the photopeak-compton edge combination in the plateau portion of the knee response, correcting equations using a linearized approximation to the electron ...

Energy Technology Data Exchange (ETDEWEB)

In the 14 MeV Neutron Laboratory, we have continued the development of a facility that is now the only one of its kind in operation in the United States. We have refined the klystron bunching system described in last year's report to the point that 1.2 nanosecond pulses have been directly measured. We have tested the pulse shape discrimination capability of our primary NE 213 neutron detector. We have converted the RF sweeper section of the beamline to a frequency of 1 MHz to replace the function of the high voltage pulser described in last year's report which proved to be difficult to maintain and unreliable in its operation. We have also overcome several other significant experimental difficulties, including a major problem with a vacuum leak in the main accelerator column. We have completed additional testing to prove the remainder of the generation and measurement systems, but overcoming some of these experimental difficulties has delayed the ...

Energy Technology Data Exchange (ETDEWEB)

(I)Results are given for photoproduction of the D{sup *} at 103 GeV. Clean signals are seen for the decay D{sup *{+-}} {yields} {pi}{sup {+-}}D{sup 0} with the D{sup 0} decaying into both K{sup {-+}}{pi}{sup {+-}} and K{sup {-+}}{pi}{sup {+-}}{pi}{sup 0}. Analysis of the Dalitz plot for the K{pi}{pi} mode gives branching fractions (BFs) for K{sup {minus}}{rho}{sup +}, K{sup *{minus}}{pi}{sup +}, and {anti K}{sup *0}{pi}{sup 0} final states. The BF for D{sup 0} {yields} K{sup {minus}}{rho}{sup +}, much lower than a previous result, is in approximate agreement with the value expected for an l=1/2 final state. (II)Inelastic and elastic J/{psi} photoproduction on H is investigated at 103 GeV. The inelastic cross section with E{sub {psi}}/E{sub {gamma}} {lt} 0.9 is significantly lower than the corresponding result for muoproduction on Fe targets, but consistent with second-order perturbative QCD calculation. The mean p{sub +} of inelastic events is larger than that of elastic events. ...

International Nuclear Information System (INIS)

A series of measurements of O_3 yield in nuclear induced O_2 and O_2-SF_6 discharges created by bombardment with energetic particles from the "1"0B(n,#alpha#)"7Li reaction are reported. Continuous irradiation at dose ratios of 10"1"5-10"1"7 eV.cm"-"3.s"-"1 and pulsed irradiation (approx.10 ms FWHM) at a peak dose rate of approx.10"2"0 eV.cm"-"3.s"-"1 were conducted. At the lower dose rates, SF_6 addition generally increased the ozone yield, which at the high dose rates, SF_6 addition decreased the observed ozone concentration. A numerical model was developed and applied to experimental conditions. The steady-state ozone concentration was found to be limited by the reaction O_3"- + O_3 #-># 2O_2 + O_2"-. A simplified analytical model of steady-state conditions was used to predict model sensitivity to various parameters. In addition to dose rate effects, pressure and temperature effect on ozone production were discussed. The present study was extended to noble gas (He, ...

Energy Technology Data Exchange (ETDEWEB)

We report on a recent search for {bar {nu}}{sub e} appearance from stopped {pi}{sup +} {yields} {mu}{sup +}{nu}{sub {mu}} and {mu}{sup +} {yields} e{sup +}{nu}{sub e}{bar {nu}}{sub {mu}} decay made by the LAMPF experiment E645. The appearance of {bar {nu}}{sub e} may occur from {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e}, {nu}{sub e} {yields} {bar {nu}}{sub eL}, or {nu}{sub {mu}} {yields} {bar {nu}}{sub eL} oscillations. Appearance may also occur from rare {mu}{sup +} {yields} e{sup +}{bar {nu}}{sub e}{nu}{sub {mu}} decay, which is allowed by a multiplicative lepton charge conservation law. The neutrino energies range from E{sub {nu}} = 0 to 52.8MeV. The neutrino detector, which is located 26.1 meters from the neutrino source, consists of a segmented liquid scintillator and proportional drift tube central detector surrounded by both active and passive shielding. The central detector detects {bar {nu}}{sub e} through the {bar {nu}}{sub e}p {yields} ne{sup +} ...