International Nuclear Information System (INIS)

The /sup 40/Ca(p,n)/sup 40/Sc reaction was studied at 134 MeV. Neutron energy spectra were measured by the time-of-flight technique with resolutions of 220 keV at angles from 0"0 to 41"0 and 415 keV out to 62"0. The 2"-,3"-,4"-,5"- band of states based on the (f/sub 7/2/,d/sub 3/2//sup -1/) 1p1h structure was observed at low excitation energies, in good agreement with known analog states in /sup 40/Ca and /sup 40/K. The shapes of the cross-section and analyzing-power angular distributions are in good agreement with distorted-wave impulse-approximation calculations using simple 1p1h (Tamm-Dancoff approximation) shell-model wave functions. A relatively strong transition to a state at E/sub x/ = 2.3 MeV with L = 3 is identified tentatively as a 4"- state with the predominant 1p1h structure (1f/sub 7/2/,2s/sub 1/2//sup -1/).

International Nuclear Information System (INIS)

To reduce the volume of radioactive wastes after evaporation, activity carriers can be separated from the inactive salt load. Boric acid separation from PWR concentrates was considered a preliminary stage for nuclide precipitation. In connection with the precipitation process, the reaction conditions for boric acid separation were determined by bench-scale experiments. After evaluating the known purification processes, crystallization was suggested as a practicable method. After inactive bench-scale experiments, mixed crystal formation with iron hexacyanoferrate for Cs removal was chosen. The disturbing effect of the complexing agents was neutralized by a pre-dose of iron-III-salts. By specifying the precipitation conditions, for Cs-134 an activity separation from 3,0 E + 06 Bg/l to 1,9 E + 02 Bg/l, and for Cs-137 from 5,9 E + 06 Bg/l to 1,2 E + 02 Bg/l was achieved. Accordingly, the decontamination factor for Cs-134 was ...

Energy Technology Data Exchange (ETDEWEB)

Scintillation light in liquid xenon excited by 100 MeV/n Al ions was detected with a home-made silicon photodiode. The diameter of the photodiode was 2 inch. The effective quantum efficiency was observed to be 22% for the wavelength of liquid xenon scintillation light (170 nm), while the effective quantum efficiency for 5.486 MeV alpha-particle excitation was 44%. An energy resolution of 0.5% rms was achieved for the energy deposition of 2.5 GeV in liquid xenon using a fast preamplifier ({approx equal} 20 ns). (orig.).

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

... dose rates inhalation iodine 134 krypton 88 nuclear decay quality factor

Science.gov (United States)

The growth of the Pd{sub 2}Si thin fllms on Si(111) substrates has been monitored by an {ital in} {ital situ} x-ray diffraction technique in vacuum and in helium atmosphere from 160 to 250 {degree}C. A familiar parabolic growth rate was found, confirming the diffusion-controlled film growth process. The activation energies were found to be 1.34 and 1.37 eV for the measurements performed in vacuum and helium environment, respectively. Stress relaxation in the growing Pd{sub 2}Si fllm was observed when the reaction temperature exceeds 200 {degree}C. The relaxed films showed a higher degree of texture as evidenced by the rocking curve measurements.

International Nuclear Information System (INIS)

Early effects of boron neutron capture therapy (BNCT) on malignant glioma are characterized by reduction of the enhancement area and regression of the peritumoral edema radiologically. The aim of this study was to investigate the early histological changes of tumors and inflammatory cells after BNCT in the rat brain. Rats were treated with BNCT using boronophenylalanine (BPA) 7 days after implantation of C6 glioma cells. The tumors were assessed with magnetic resonance imaging and histopathological examination at 4 days after BNCT. The mean tumor volumes were 39#+-#2 mm"3 in the BNCT group and 134#+-#18 mm"3 in the control group. In the BNCT group, tumor cells showed a less pleomorphic appearance with atypical nuclei and mitotic figures. The Ki-67 labeling index was 6.5%#+-#4.7% in the BNCT and 35%#+-#3.8% in the control group. The reactions of the inflammatory cells were examined with ED-1 as macrophage marker and OX42 as microglia marker. ...

CERN Document Server

High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to ...

Energy Technology Data Exchange (ETDEWEB)

A noninvasive method is described for estimating local cerebral blood flow (LCBF) and local partition coefficients by means of computed tomographic scanning during inhalation of 30% stable xenon gas in oxygen. Time-dependent xenon concentrations in arterial blood and brain tissue during the wash-in and washout phases are used to calculate partition coefficients and LCBF values by means of a least-squares curve-fitting analysis. Control values for partition coefficient and LCBF obtained from control subjects with minor head trauma in the chronic stage were compatible with those in several past reports, and reproducibility was satisfactory. The theoretic grounds underlying this new method of curve-fitting analysis are discussed.

Science.gov (United States)

... 129 US Armored Division Casualty and Tank Loss Rates ..... 132 British Casualty and rank Loss Rates in Operation "Goodwood" . 134 Page 5. ...

International Nuclear Information System (INIS)

Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has a merit to mitigate heat effect of the first EUV mirror. The fabrication method has another merit to control not only density ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The concentrations of {sup 137}Cs and {sup 134}Cs in Malaysian marine sediments were measured by gamma-ray spectrometry with a high-purity germanium (HPGe) detector connected to a multichannel analyzer. In general, the {sup 137}Cs concentration in Malaysian marine sediments has been found to be very low and less than 5 Bq/kg dry weight with the exception of those from a few sampling locations. The concentration of {sup 134}Cs was found to be less than the minimum detectable activity for the measuring condition used. Data reported in this paper were found to be comparable with results from within the region and thus can be used as reference data for the country.

Energy Technology Data Exchange (ETDEWEB)

Monitoring for xenon radionuclides which are produced in a nuclear detonation can provide a strong deterrent to the violation of a Comprehensive nuclear Test Ban Treaty (CTBT). There are 18 known radioactive xenon isotopes produced in nuclear fission with half-lives ranging from less than one second to 11.9 days. However, only four of these remain in significant amounts more than a day after a detonation. In order for radioxenon monitoring to be practical, it was necessary to develop an automated measurement system which could operate unattended for periods of months, measure the entire spectrum of radioxenons, and provide hundreds of times better sensitivities than current laboratory procedures. This capability was developed at the US Department of Energy`s Pacific Northwest National Laboratory based on rapid separation of atmospheric xenon coupled with a unique high sensitivity measurement device for the radioxenons. A ...

International Nuclear Information System (INIS)

We obtained the ratios of "1"3"4Cs/"1"3"7Cs and "1"5"4Eu/"1"3"7Cs in spent PWR fuels with gamma scanning equipment of irradiated material examination facility. The fuel segments, of which the burn-up is about 40 GWD/MTU and its cooling time is 8.4 years, are prepared in Post Irradiated Examination Facility and transported to IMEF. By considering of multi-peaks of "1"3"4Cs and "1"5"4Eu, we obtained the relative efficiency of the gamma scanning system as a function of energy. And finally we obtained the number ratios of radioactive nuclides in 72 fuel pellets, radioactive "1"3"4Cs/"1"3"7Cs and "1"5"4Eu/"1"3"7Cs. (author). 4 refs., 27 tabs., 28 figs.

Science.gov (United States)

Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,{tau}) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe{sup 8+}. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe{sup 8+} transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)

International Nuclear Information System (INIS)

We have observed EUV spectra from the Large Helical Device (LHD) at the National Institute for Fusion Science (NIFS). We measured spectra of impurity ions; carbon, iron, xenon, tin and tungsten ions. In some cases, the plasma evolution was stable and a steady discharge was obtained, but sometimes the plasma underwent radiation collapse and rapid cooling. For carbon and iron spectra, we studied plasma diagnostics by intensity ratios of spectral lines. For other spectra of higher Z element, xenon, tin and tungsten, we studied mainly on line identifications comparing with theoretical calculations and experimental data. Related atomic data for these researches will be also discussed. (author)

Energy Technology Data Exchange (ETDEWEB)

An embodiment of a mercury-free fluorescent lamp combines a low pressure rare gas discharges with a phosphor having a quantum efficiency grater than one. The choice of the rare gas depends on a number of factors, one of which is the resonance transition energy. Less demand is placed the quantum efficiency of the phosphor for a lower energy resonance photon. Xenon has the lowest energy resonance transition of the stable rare gases at 8.5 eV (147 nm) and thus is a good candidate to study. The usefulness of a xenon-based discharge depends on the radiant emittance of the discharge at the resonance wavelength of 147 nm. The radiant emittance from a low pressure xenon positive column discharge is measured using two independent techniques. The first relies on the measurement of the resonance level density using absorption techniques. The effective decay rate of the resonance level is calculated using radiation trapping theory. The ...

Energy Technology Data Exchange (ETDEWEB)

A krypton recovery pilot plant has been completed for the Power Reactor and Nuclear Fuel Development Corporation. This is the first industrial facility in the world to make practical use of development results for offgas treatment and storage from nuclear facilities. The cryogenic distillation process was adopted as a proven and reliable method to separate krypton and xenon, and to reduce gas effuents to a level so low that the decontamination factor amounts to more than 1000.

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 radioactive cooling of the ...

International Nuclear Information System (INIS)

Description or function: WLUP contains validated WIMS-D formatted cross section libraries in 69 and 172 energy group structures for nuclear reactor calculations. Materials from recently released evaluated nuclear data libraries are included. The NJOY nuclear data processing system was applied for generating the cross section files following the models and conventions built into the WIMS-D lattice code. The relevant features for the WIMS users are: - Energy group structures: 69 and 172 energy groups. - List of materials: WIMS ID, general information, source of data. - Cross sections: 69 and 172 group plots. - Resonance data: WIMS ID, temperature, background cross sections. - Goldstein-Cohen factors: Goldstein-Cohen lambda values. - Thermal scattering data: thermal scattering laws and P1 matrixes. - Fission spectrum: fission spectrum data. - Burnup data: burnup chains. - Fission product yields: fission yield tables. - Pseudo lumped fission product: Description of pseudo fission product. ...

International Nuclear Information System (INIS)

We studied regional myocardial perfusion by scintigraphic computer-assisted analysis of initial distribution, washout rates, and residual activity of "1"3"3Xe injected into the left coronary artery of four patients with normal arteriograms and 14 patients with coronary stenosis. At rest, residual activity in poststenotic regions was always greater than in control regions, but initial washout rates were not slower. During angina, following xenon injections, the amount of indicator distributed to the poststenotic regions was markedly reduced; the increase of the initial washout rates was smaller than in control regions relative to rest, and residual activity was higher. Initial washout rates did not differ as much as from those of normal myocardium because in severe ischemia too little indicator is deposited initially in these regions to produce a change of any magnitude. Indeed, when angina was induced immediately after the xenon injection, ...

International Nuclear Information System (INIS)

Non-invasive methods are described for estimating local cerebal blood flows (LCBF) and local partition coefficients (L#lambda#) during inhalation of 30 % stable xenon gas (Xe) in oxygen during CT scanning. After the denitrogenation with pure oxygen breathing, 30 % Xe is inhaled for four minutes to minimize subanesthetic effects with a rubber facemask and the delivery system of Xe. Local time-#DELTA# Hounsfield units curve during the Xe wash-in and wash-out phase is utilized in order to calculate L#lambda# and LCBF using a least squares curve fitting analysis. Calculated L#lambda# and LCBF with the new method manifested reasonable distribution between the grey and white matters, and reproducibility was excellent in our study. Several case studies of patients with cerebral infarction are presented to demonstrate the characterization of L#lambda# and LCBF patterns in various tissues and theoretical grounds underlying the new method of curve fitting analysis are ...

International Nuclear Information System (INIS)

The purpose of this work was to develop and evaluate a method of locating breached fuel within the Fast Flux Test Facility (FFTF) reactor based on the relative response of the delayed neutron monitors (DNM) located on each of the three primary sodium cooling loops. The primary method of location is the use of tag gas containing unique ratios of the noble gases xenon and krypton. Although the tag gas system works quite well, it is relatively expensive because of the costs of preparing and loading the gas into each fuel pin. Triangulation of DNM signals could potentially decrease tag gas costs while maintaining overall location reliability.

Energy Technology Data Exchange (ETDEWEB)

Characteristics of lead-zirconate-titanate (PZT) elements were studied by directly irradiating them with a 400 MeV/n Xe beam. The elements were sensitive to 10{sup 4} Xe ions and their output amplitudes were proportional to the beam intensity. An ensemble of those output amplitudes displayed a Bragg-curve-like response towards the range of 400 MeV/n Xe ion. We discuss the potential of PZT elements as a radiation detector and their application to high-intensity and high-energy detectors. (author)

International Nuclear Information System (INIS)

In Pressurised heavy water reactors (PHWRs), neutron poison in the moderator is used to compensate the excess reactivity present in the core on different occasions such as xenon decay during synchronization just after poison out period or start ups from xenon free conditions. It is also used in secondary shutdown system (SDS-2), where required amount of neutron poison is injected directly into the moderator within 2.5 seconds. Further, it is also used for over poisoning the moderator to achieve the guaranteed shutdown state when the regular shutdown systems are taken for maintenance. Generally, two types of moderator poisons are used in power reactors to balance the reactivity of the core and they are boron and gadolinium. Gadolinium is used in the form of gadolinium nitrate (Gd(NO3)3.6H2O). The paper gives the details of estimation of reactivity coefficients of gadolinium for 540 MWe PHWR for different operating conditions. These neutron ...

Science.gov (United States)

... 25.0003 -82.3104 7563.4132 315.7812 320.6632 -1.9312 -23.4836 134.1467 137.3888 78725.0000 25.0011 -82.3114 7552.3932 314.2244 319.0740 -1.9968 - 22.3120 ...

UK PubMed Central (United Kingdom)

This study prospectively assessed the outcome of 134 cemented titanium stems and serum ion levels. The stems were polished (0.1 μm Ra) with circular cross section. At the end point,...Full Text Available

International Nuclear Information System (INIS)

... charge-exchange reactions dwba finite-range interactions helium 3 reactions

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Energy Technology Data Exchange (ETDEWEB)

In this work, a new class of thiadiazole derivatives, namely 3,5-bis(2-thienyl)-1,3,4-thiadiazole (2-TTH) and 3,5-bis(3-thienyl)-1,3,4-thiadiazole (3-TTH), have been studied as possible corrosion inhibitors for mild steel in molar hydrochloric acid (1M HCl). Polarisation curves and AC impedance methods have been used. These studies have shown that the thiadiazole derivatives were very good inhibitors for mild steel in 1M HCl. Comparison of results showed that 3-TTH was the best inhibitor. The potential of zero charge (PZC) of mild steel was studied by ac impedance method, and the mechanism of adsorption has been predicted. X-ray photoelectron spectroscopy surface analysis with thiadiazole derivatives shows that it chemisorbed at the mild steel/HCl interface. The adsorption of these inhibitors followed Langmuir's adsorption isotherm. The electronic properties of 2-TTH and 3-TTH, obtained using the AM1 semi-empirical quantum chemical ...

British Library Electronic Table of Contents (United Kingdom)

In this study, wood samples were exposed to light irradiations (direct sunlight, xenon lamp, mercury vapour lamp) and thermal treatments were carried out in dry- and in humid conditions at 90degreeC. One part of the samples was covered by an aluminium plate during light irradiation. The samples under the aluminium plate also suffered considerable chemical changes, monitored by infrared technique and colour measurement. The sunlight produced greater colour change under the aluminium plate than the artificial light sources. During light irradiation, the carbonyl band having two maximum at 1700 and 1746cm-1 increased and the peak of the aromatic skeletal vibration arising from lignin (1510cm-1) decreased together with the guaiacyl vibrations at 1275cm-1. There was absorption decrease at 1174c...

Energy Technology Data Exchange (ETDEWEB)

We demonstrate that the nanoparticle formation during laser ablation of metals by short (of a few tens of ps) laser pulses strongly depends on the concentration of surrounding gas. While, at vacuum conditions, nanoparticle formation shows very ''sharp'' atomic force microscope images of aggregated clusters, following with clear appearance of plasmon resonance on the absorption spectra of deposited films, an addition of gas particles starts to decrease the probability of cluster formation. This process shows a threshold for both helium (33 torr) and xenon (12 torr) above which no surface plasmon resonance and correspondingly no observable nanoparticles on the deposited surfaces were detected. The destruction of nanoparticle formation was attributed to the negative influence of surrounding gas particles on ablated particles aggregation. (orig.)

Energy Technology Data Exchange (ETDEWEB)

By using megaelectronvolt /sup 4/He ion backscattering techniques and transmission electron microscopy, the authors have investigated the interactions of ion beams with thin film structures in a number of silicide-forming systems. The mixed layer was found to be an equilibrium compound for near-noble metals and an amorphous phase for refractory metals. Differences in behavior have also been observed in near-noble metal systems. For palladium, the Pd/sub 2/Si phase grew with ion dose and remained crystalline up to high dose. For nickel, the compound Ni/sub 2/Si was formed initially and became amorphous on prolonged irradiation. All the results indicate the significance of atomic mobility at target temperatures in determining the phase formation and in explaining the sensitivity of the silicides to ion bombardment.

Energy Technology Data Exchange (ETDEWEB)

Describes performance of excavator teeth manufactured with a new hard alloy. The alloy was developed by the Donetskii Politeknicheskii Institute. Its composition consists of a high-chromium steel with a larger amount of titanium than serial alloy, and a nitrogen additive. Trial tests of new alloy teeth were carried out in the Severnyi and Vershinskii coal surface mines. The teeth were attached to EhRP, EhPG and EhR bucket wheel excavators. Abrasive wear of 129 experimental teeth and 134 serial teeth was compared for different excavation conditions. Test results are tabulated; advantages of the new experimental teeth are listed. 3 refs.

Energy Technology Data Exchange (ETDEWEB)

Alpha particles, tritons, deuterons and protons accompanying /sup 252/Cf fission were registered in coincidence with both fission fragments by means of a system containing two-dimensional position-sensitive silicon detectors. Angular distributions, kinetic energy spectra of light charged particles as well as mass distributions of fission fragments in coincidence with light charged particles were measured. The experimental results are compared with some theoretical models.

International Nuclear Information System (INIS)

Page 1. ANALYSIS OF REACTION MIXTURE OF LAURIC ACID WITH MONO-

Energy Technology Data Exchange (ETDEWEB)

A noninvasive, simplified method using inhalation of stable xenon (Xe{sup s}) and computed tomographic (CT) scanning to estimate regional cerebral blood flow (rCBF) and regional partition coefficient (r{lambda}) is described. Twenty-four patients with cerebrovascular occlusive disease and six volunteer controls inhaled 30% Xe{sup s} and 70% oxygen for 180 seconds and exhaled for 144 seconds during serial CT scanning without denitrogenation. The end-tidal Xe{sup s} concentration was continuously monitored with a thermoconductivity analyzer to determine the build-up range (A value) and build-up rate constant (K value) for arteries with the curve fitting method. The time-CT number (Hounsfield unit) curve for cerebral tissue during the Xe{sup s} washin and washout phases was used to calculate r{lambda} and rCBF using least squares curve fitting analysis. The resultant r{lambda} and rCBF map demonstrated a reliable distribution between the gray and white matter, and ...

Energy Technology Data Exchange (ETDEWEB)

The nuclear reactions are described which govern the stellar evolution.

International Nuclear Information System (INIS)

... alpha reactions angular distribution energy-level transitions iridium 185 iridium

International Nuclear Information System (INIS)

... compilation fission products j codes mixed oxide fuels neutron reactions

International Nuclear Information System (INIS)

In the group of persistent aromatic hydrocarbons, the highest values were determined for polychlorinated biphenyls (PCB), total DDT and hexachlorobenzene (HBC). Comparisons of the relevant median values for the past six years led to the conclusion that the steep initial decline in the breast milk concentrations of DDT and HBC was followed by reductions at a much lower pace in the years after 1987. The time course of the concentration of the total PCB did not appear to follow any particular pattern. The mean contents of lead and cadmium remained by a wide margin below the threshold values for these heavy metals and thus were of no relevance from the toxicological point of view. It was found that the 134 and 137 cesium isotopes constituted no particular health hazard for breast-fed infants, as the relevant concentrations in breast milk were low. (VHE).

Energy Technology Data Exchange (ETDEWEB)

Boiling jet impingement cooling is currently being explored to cool power electronics components. In hybrid vehicles, inverters are used for DC-AC conversion. These inverters involve a number of insulated-gate bipolar transistors (IGBTs), which are used as on/off switches. The heat dissipated in these transistors can result in heat fluxes of up to 200 W/cm{sup 2}, which makes the thermal management problem quite important. In this paper, turbulent jet impingement involving nucleate boiling is explored numerically. The framework for these computations is the CFD code FLUENT. For nucleate boiling, the Eulerian multiphase model is used. The numerical results for boiling water and R113 jets (submerged) are validated against existing experimental data in the literature. Some representative IGBT package simulations that use R134a as the cooling fluid are also presented. (author)

British Library Electronic Table of Contents (United Kingdom)

Chose the arid interior district Shiyang River basin four issues of Landsat/TM images from 1986 to 2006 to visually interpret, and analyze the natural succession of ecological environment and the landscape pattern characteristic under the human activity interference. The results showed that in past 20years, the number of landscape patch has increased, but the average patch size was decreasing, which explained that the landscape fragmentation degree was increasing, the landscape integrity was declining. The edge density of landscape remained invariable basically, which explained its stability maintained good. The diversity and evenness index continually enhanced, the diversity increased from 0.73 in 1986 to 0.84 in 2006. The mean core patch area of study area reduced from134.47hm2 in 1994 t...

British Library Electronic Table of Contents (United Kingdom)

In this work the DC and AC characteristics for metal-LB film-metal structures deposited by a standard Langmuir-Blodgett film deposition technique are investigated. The conduction mechanism has been studied for a thin film structure in which a calix[4]arene substituted with carboxylic acid groups has been deposited alternately with a calix[4]arene molecule substituted with amine groups. This LB film structure shows a typical insulating behaviour for low voltage values and the Schottky effect becomes dominant when the voltage increases. The conductivity at low voltage values was found to be 1.34x10^-^1^3Scm^-^1. The height of the potential barrier was determined to be 1.65eV for this alternate layer LB film system.

International Nuclear Information System (INIS)

Bone mineral content as determined by computerized tomography (CT) and mechanical strength on axial loading were compared in 36 cadaveric femur specimens. Based on the CT measurements of density and area, the mass of a transverse slice of the femur was estimated. Highly significant correlations were demonstrated between strength and cancellous bone density. Even higher correlations were revealed when the bone masses of the proximal and distal femoral areas were calculated. Based on these findings, an equal distribution of the effective mass of the femur was postulated. This hypothesis was confirmed in an experimental rotational model. The CT attenuation values were also correlated to direct measurements of bone mineral content, i.e. calcium. Moreover, the strength of different metal implants, commonly used in femoral neck fractures, were assessed in cadaver specimens. 134 refs., 13 figs., 12 tabs.

Energy Technology Data Exchange (ETDEWEB)

A theoretical model, which describes subband gap photoexcitation involving localized electronic states, was developed. The escape probability of a charge carrier trapped in a localized state is considered via Poole-Frenkel, direct tunneling, or phonon-assisted tunneling processes, as competing escape mechanisms. Photoelectrochemical experiments were performed on the passive films formed on zirconium and amorphous iron-zirconium alloys and on pure HfO/sub 2/ films and HfO/sub 2/ films implanted with varying concentrations of xenon. These films were found to possess some degree of disorder depending on the substrate, the thickness of the film, and the extent of implantation. The spectral dependence of the photocurrent in all of the films studied is considerably different from what was found for crystalline passive films. The potential dependence of the photocurrent yields Poole-Frenkel behavior. Reverse tunneling processes were also observed at low photon energies ...

Energy Technology Data Exchange (ETDEWEB)

A joint US/Russia program is being conducted to develop, fabricate, launch, and operate a solar dynamic demonstration system on Space Station Mir. The goal of the program is to demonstrate and confirm that solar dynamic power systems are viable for future space applications such as the International Space Station Alpha. The major components of the system include a heat receiver, a closed Brayton cycle power conversion unit, a power conditioning and control unit, a concentrator, a radiator, a thermal control system, and a Space Shuttle carrier. This paper discusses the design of the heat receiver component. The receiver comprises a cylindrical cavity, the walls of which are lined with a series of tubes running the length of the cavity. The engine working fluid, a mixture of xenon and helium, is heated by the concentrated sunlight incident on these tubes. The receiver incorporates integral thermal storage, using a eutectic mixture of lithium fluoride and calcium ...

Energy Technology Data Exchange (ETDEWEB)

Noninvasive and simplified methods for estimating regional cerebral blood flow (CBF) and regional partition coefficient ({lambda}) using the inhalation of stable xenon (Xe{sup s}) and computed tomographic (CT) scanning are described. Thirty percent Xe{sup s} in 70% oxygen was inhaled for 240 seconds and exhaled for 160 seconds during serial CT scanning without denitrogenation in 26 patients with cerebrovascular diseases and four volunteer controls. During the investigation, the end-tidal Xe{sup s} concentration was continuously monitored with a thermoconductivity analyzer to determine the build-up range (A value) and build-up rate constant (K value) of the artery by the curve fitting method. Calculated A and K values were corrected by the following formulae reported previously: for patients aged 0-20 years, A{sub e} = 0.75A{sub a} + 2.15, K{sub e} = 0.67K{sub a} + 0.69; 21-40 years, A{sub e} = 0.56A{sub a} + 3.24, K{sub e} = 0.38K{sub a} + 1.12; 41-60 years, A{sub ...

International Nuclear Information System (INIS)

A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between each of the four independent variables. The ...

Energy Technology Data Exchange (ETDEWEB)

In the group of persistent aromatic hydrocarbons, the highest values were determined for polychlorinated biphenyls (PCB), total DDT and hexachlorobenzene (HBC). Comparisons of the relevant median values for the past six years led to the conclusion that the steep initial decline in the breast milk concentrations of DDT and HBC was followed by reductions at a much lower pace in the years after 1987. The time course of the concentration of the total PCB did not appear to follow any particular pattern. The mean contents of lead and cadmium remained by a wide margin below the threshold values for these heavy metals and thus were of no relevance from the toxicological point of view. It was found that the 134 and 137 cesium isotopes constituted no particular health hazard for breast-fed infants, as the relevant concentrations in breast milk were low. (VHE) [Deutsch] In der Gruppe der persistenten Chlorkohlenwasserstoffe werden die hoechsten Konzentrationen bei den ...

Energy Technology Data Exchange (ETDEWEB)

The shrinking core model is examined for gas-solid noncatalytic reactions with a self-inhibited rate form and it is shown that multiple reaction pathways are possible for solid particles reacted under identical conditions. The observed reaction rate can have up to two discontinuities (jumps) during reaction for particles of spherical and cylindrical shape. The geometric instability analysis reveals that the reaction interface is stable under a very limited set of conditions only for solid particles of slab geometry. For a sphere or cylinder at large Biot numbers the reaction interface is always potentially unstable. This model provides a plausible explanation for gas-solid reactions which exhibit erratic shrinking core behavior.

International Nuclear Information System (INIS)

... kinetics chemical reactions energy dependence ion-molecule collisions milli

International Nuclear Information System (INIS)

... levels excited states mev range 10-100 proton reactions proton spectra protons

Science.gov (United States)

The chemical reaction between nitric acid and sodium chloride was investigated in onder to provide preliminary information for subsequent studies on the interaction between simulated Purex waste solution and salt. The reaction is characterized by the production of chlorine and nitrosyl chloride and can be considered to be the same as the aqua regia reaction. Within the limits of the conditions imposed by the projected field studies, the acid concentration and temperature are the two parameters which control the extent of the interaction. (auth)

Energy Technology Data Exchange (ETDEWEB)

Synthesis of silver nanoparticles based on a polyol process and variable frequency microwave (VFM) was investigated. Comparing to a thermal method, the reaction by VFM radiation was much faster. The effects of silver nitrate concentration, poly(N-vinylpyrrolidone) (PVP) concentration, reaction time and reaction temperature were studied. It was found that the higher concentration of silver nitrate, longer reaction time and higher temperature increased the particle size while the higher concentration of PVP decreased the particle size.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

... of Sciences (Poland) [5.48 Megabytes] NUCLEAR PHYSICS AND RADIATION

Czech Academy of Sciences Repository

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KoreaScience (Korea)

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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.

Science.gov (United States)

During the period covered by this report research has been concerned with the study of photo-induced electron transfer reactions from porphyrins to acceptor molecules with time-resolved Electron Paramagnetic Resonance (EPR) methods. Excited-state electron transfer reactions are of importance from a fundamental point of view and in connection with applications in homogeneous and heterogeneous photosensitization, photopolymerization, and solar energy conversions. For this reason, the study of photo-induced electron transfer reactions is of considerable interest.

International Nuclear Information System (INIS)

... chemical reactions high temperature lattice parameters microhardness

Science.gov (United States)

Group B Streptococcus

Energy Technology Data Exchange (ETDEWEB)

A direct process of making ethylenediamine dinitrate through the reaction of ethylenediamine and ammonium nitrate is described.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

In this paper, steady-state isotopic transient kinetic analysis (SSITKA) is used to study two model reactions, CO oxidation and CO-NO reactions, on a typical formulation of a three-way auto-catalyst. Under steady-state conditions, abrupt switches in the isotopic composition of CO ("1"2C"1"6O/"1"3C"1"8O) were carried out to produce isotopic transients in both labeled reactants and products. Along with the determination of the average surface lifetimes and concentrations of reaction intermediates, an analysis of the transient responses along the carbon reaction pathway indicated that the distribution of active sites for the formation of CO_2 was bimodal for both reactions. Furthermore, relatively few surface sites contributed to the overall reaction rate.

International Nuclear Information System (INIS)

Direct nuclear reactions are commonly understood in terms of distorted wave (DW) formalisms. In the case of a single nucleon knockout or transfer reaction the DW analysis provides a reasonable understanding of the observed data. On the other hand the predictions based on different available information inputs have been verified with the observations consistently. In the case of direct reactions involving nuclear clusters however, the DW predictions have been found to disagree with the observations in most cases. The outcome of these and other improvements in the intermediate energy nuclear phenomena involving direct reactions are highlighted. (author). 13 refs., 18 figs.

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The document describes the outcome of the CSN/CIEMAT-00 interlaboratory test comparison among environmental radioactivity laboratories. the exercise was organised according to the ISO-43 and the ISO/IUPAC/AOAC Harmonized Protocol for the proficiency testing of analytical laboratories. the test sample was a soil containing environmental levels of K-40, Ra-226, Ac-228, Sr-90, Cs-137, Cs-134, Pu (239-240) y Am-241. the Universidad Autonoma de Barcelona prepared the material and reported adequate statistical studies of homogeneity. The results of the exercise were computed for 30 participating laboratories, and their analytical performance was assessed using the u-score approach. A raised percentage of satisfactory laboratory performance has been obtained for all the analysis, being the best performance in gamma measurements. The exercise has drawn that several laboratories have difficulties in the evaluation of combined uncertainty, mainly in analysis involving ...

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An experimental evaluation of the Fano factor F in silicon at hard X-ray energies (5.9-136.5 keV) has been performed by means of a low-noise, high charge collection efficiency silicon drift detector with on-chip electronics. A dependence of F from the detector temperature as well as from the energy of the X-ray photons has been found. Assuming a pair creation energy equal to 3.64 eV, at +20 deg. C the F factor was observed to vary from 0.124{+-}0.006 at 5.9 keV up to 0.159{+-}0.002 at 122 keV. At -35 deg. C, the change of F with respect to the photon energy was less remarkable but nevertheless statistically significant, from 0.123{+-}0.002 at 5.9 keV up to 0.134{+-}0.001 at 122 keV. To our knowledge, the present results represent the first experimental evidence of an energy dependence of the Fano factor in silicon at hard X-ray energies.

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Multilayer mirror coatings which reflect extreme ultraviolet (EUV) radiation are a key enabling technology for EUV lithography. Mo/Si multilayers with reflectances of 67.5% at 13.4 nm are now routinely achieved and reflectances of 70 2% at 11.4 nm were obtained with MO/Be multilayers. High reflectance is achieved with careful control of substrate quality, layer thicknesses, multilayer materials, interface quality, and surface termination. Reflectance and film stress were found to be stable relative to the requirements for application to EUV lithography. The run-to-run reproducibility of the reflectance peak position was characterized to be better than 0.2%, providing the required wavelength matching among the seven multilayer-coated mirrors used in the present lithography system design. Uniformity of coating was improved to better than 0.5% across 150 mm diameter substrates. These improvements in EUV multilayer mirror technology will enable us to meet the stringent ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is the measurement of two-phase flow parameters to support development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR). A single element finned Fuel Element Simulator was used with R134a Freon flow. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distributions were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant vibration and the local void distribution ...

International Nuclear Information System (INIS)

Purpose: The aim of this study was to demonstrate the typical appearance of ganglioneuromas in computer-assisted tomography (CT), and magnetic resonance imaging (MRI). Material and methods: Retrospective analysis of diagnostic imaging (9 CT, 6 MRI) in 9 children aged 3 to 15 years with the histological diagnosis of ganglioneuroma. Results: The tomographies showed large (max. 13.4 cm in diameter) round or oval tumors with sharp delineation. The sites of the tumors were the retroperitoneum (5), the mediastinum (3), and the adrenal gland (1). Intraspinal tumor involvement occurred in 4 cases. On comparing CT with MRI, MRI was more accurate in defining the intraspinal involvement. The ganglioneuromas were of hypodense appearance in the native CT scan and showed moderate enhancement upon administration of contrast media. In five patients tumor calcifications with a disseminated sprinkled pattern were seen in CT. In MRI T_1-weighted scans the tumors were homogeneous and ...

International Nuclear Information System (INIS)

The measurement of two-phase flow parameters for development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR) is discussed in this paper. A single element finned Fuel Element Simulator (FES) was used with Freon 134a as the working fluid. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer present. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distribution were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant vibration and the local ...

Science.gov (United States)

Two enantioselective, potentiometric membrane electrodes (EPMEs) based on maltodextrins with different value of dextrose equivalent (DE) (maltodextrin I: DE 4.0-7.0; maltodextrin II: DE 16.5-19.5) were proposed for the assay of baclofen enantiomers in baclofen raw materials and from its pharmaceutical formulation, Norton-Baclofen tablets. The slopes of the electrode function of the proposed electrodes were 55.0 mV/pS-baclofen for maltodextrin I-based electrode and 59.0 mV/pR-baclofen for maltodextrin II-based electrode and the detection limits were 1.34 x 10(-6) mol l(-1) (S-baclofen) and 2.52 x 10(-10) mol l(-1) (R-baclofen), respectively. The surfaces of the electrodes are stable and easily renewable by simply polishing on alumina paper. PMID:15598435

British Library Electronic Table of Contents (United Kingdom)

We found that the androgenic gland (AG) of Macrobrachium rosenbergii possesses three cell types. Type I cells are small polygonal shaped-cells (13.4 mu m in diameter), stain strongly with hematoxylin-eosin (H&E), have abundant multilayered rough endoplasmic reticulum (rER), and nuclei containing mostly heterochromatin. Type II cells are slightly larger (18.6 mu m in diameter), stain lightly with H&E, have rER with dilated cisternae, and nuclei containing mostly euchromatin. Type III cells (previously undescribed) are similar in size and shape to type I cells, but the cytoplasm is unstained and they have a high amount of smooth endoplasmic reticulum (sER) and mitochondria with tubular cristae. Bilateral eyestalk-ablation resulted in AG hypertrophy with a proliferation and predominance of ty...

Energy Technology Data Exchange (ETDEWEB)

A algorithm was developed to determine the characteristic parameters of PWR spent fuel, such as burnup, cooling time and initial enrichment of {sup 235}U by use of gamma-ray activity ratios of {sup 134}Cs/{sup 137}Cs, {sup 154}Eu/{sup 137}Cs and {sup 106}Ru/{sup 137}Cs from the high resolution gamma-ray spectroscopy and ORIGEN-S calculations. For the verification of the method developed, gamma-ray measurements of Kori-1 and Kori-2 nuclear fuel rods were carried out using HPGe gamma ray scanning system. As a results, it is revealed that the measured values are in a good agreement with the operator declared values within the about {+-} 5% errors. Besides, the under-water burnup measuring device has been designed to measure the gamma-ray from the PWR spent fuel assembly. This device will be set up in the pool of Post-Irradiation Examination Facility(PIEF), and used in determination of the average burnup, cooling time and initial enrichment of the PWR spent fuel ...

Energy Technology Data Exchange (ETDEWEB)

The aim of this research was to examine the energy equivalents of inputs and output in greenhouse vegetable production in the Antalya province of Turkey. For this purpose, the data for the production of four greenhouse crops (tomato, cucumber, eggplant and pepper) were collected in eighty-eight greenhouse farms by questionnaire. The results revealed that cucumber production was the most energy intensive of among the four crops investigated. Cucumber production consumed a total of 134.77 GJha{sup -1} followed by tomato with 127.32 GJha{sup -1}. The consumption of energy by eggplants and pepper were 98.68 and 80.25 GJha{sup -1}, respectively. The output-input energy ratio for greenhouse tomato, pepper, cucumber and eggplant were estimated to be 1.26, 0.99, 0.76 and 0.61, respectively. This indicated an intensive use of inputs in greenhouse vegetable production not accompanied by increase in the final product. This can lead to problems associated with these inputs ...

CERN Document Server

We present space-based photometry of the transiting exoplanetary system HD 209458 obtained with the MOST (Microvariablity and Oscillations of STars) satellite, spanning 14 days and covering 4 transits and 4 secondary eclipses. The HD 209458 photometry was obtained in MOST's lower-precision Direct Imaging mode, which is used for targets in the brightness range $6.5 < V < 13$. We describe the photometric reduction techniques for this mode of observing, in particular the corrections for stray Earthshine. We do not detect the secondary eclipse in the MOST data, to a limit in depth of 0.053 mmag (1 \\sigma). We set a 1 \\sigma upper limit on the planet-star flux ratio of 4.88 x 10^-5 corresponding to a geometric albedo upper limit in the MOST bandpass (400 to 700 nm) of 0.25. The corresponding numbers at the 3 \\sigma level are 1.34 x 10^-4 and 0.68 respectively. HD 209458b is half as bright as Jupiter in the MOST bandpass. This low geometric albedo value is an ...

International Nuclear Information System (INIS)

When clinoptilolite is immobilized in cement-based composites, a series of reactions occur, leading to release of Cs. These reactions occur in three overlapping stages: a rapid ion exchange, followed by a somewhat slower reaction between clinoptilolite and principally the Ca(OH)_2 component of cement, and, in the longer term, slower reactions with C-S-H leading either to formation of low-lime C-S-H at temperatures below 100"0C or 11 A (1.1 nm) tobermorite at higher temperatures. Kinetic data are presented to evaluate the rate of physical consumption of the zeolites at 70 and 150"0C. Reactions occurring above 100"0C appear to result in the development of extensive microcracking of cement-zeolite composites containing 50% zeolite.

International Nuclear Information System (INIS)

Cerebral blood flow (CBF) and cerebrovascular reserve capacity (CRC) were measured by stable xenon computerized tomography (Xe-CT) and acetazolamide test in 15 patients with cerebrovascular disease before and after extracranial-intracranial (EC-IC) bypass surgery for minor stroke, reversible ischemic neurological deficit or transient ischemic attack. All had angiographically shown occlusive lesions of the major arterial trunk. In the present series, global analysis showed that the bypass did not increase the resting rCBF, but did increase the rCRC. We divided the patients into four groups according to the preoperative resting rCBF and rCRC. All 3 patients with normal resting rCBF and reduced rCRC showed postoperative improvement of rCRC. Of 6 patients with reduced CBF and reduced CRC, three had postoperative increase in resting CBF and four had increased CRC. One of two patients with reduced CBF and normal CRC showed only an increase in CRC. We propose that reduced ...

International Nuclear Information System (INIS)

Full text: In the upper layers of the Earth's atmosphere, molecular nitrogen absorbs the extreme ultraviolet (XUV) solar radiation. The absorption is associated with dipole-allowed excitation of states of singlet ungerade symmetry ("1#SIGMA#"+_u and "1#PI#_u), which are known to undergo predissociation due to coupling with a mainfold of "1#PI#_u states. We determined new N_2 isotopic lifetimes of many "1#SIGMA#"+_u and "1#PI#_u states via line broadening measurements in the frequency domain. Ultrahigh resolution XUV + UV ionization spectra were recorded (bandwidth #approx# 250 MHz, resolving power 10"7), from which the natural linewidth, i.e. lifetime, was determined. These lifetimes provide new information about the predissociation of the singlet ungerade states in N_2. Tunable narrowband XUV radiation was produced by successively pulsed amplification of cw dye laser radiation, frequency doubling the pulsed visible laser beam into the UV and frequency tripling the UV in a ...

Energy Technology Data Exchange (ETDEWEB)

Absorption of the excimer laser radiations of 193-nm argon fluorine and 308-nm xenon chloride in balanced salt solution, sodium hyaluronate, and human cadaver eyes was measured. The absorption of these materials as considerably different for the two wavelengths; we found that 308-nm light experienced much less absorption than the 193-nm light. The extinction coefficient (k) for 308 nm was k = 0.19/cm for balanced salt solution and k = 0.22/cm for sodium hyaluronate. In contrast to this, the extinction coefficient for 193 nm was k = 140/cm for balanced salt solution and k = 540/cm for sodium hyaluronate. Two 1-day-old human phakic cadaver eyes showed complete absorption with both wavelengths. Using aphakic eyes, incomplete absorption was noted at the posterior pole with 308 nm and complete absorption was noted with 193 nm. The extinction in the anterior part of aphakic eyes (the first 6 mm) was 4.2/cm for 308 nm, meaning that the intensity of the light is reduced by ...

Energy Technology Data Exchange (ETDEWEB)

This book examines some of the basic principles behind chemical reaction kinetics. Topics considered include the classical trajectory approach to reactive scattering; periodic orbits and theory of reactive scattering; and semiclassical reactive scattering.

International Nuclear Information System (INIS)

... reactions differential cross sections dwba excitation excited states mev range

Energy Technology Data Exchange (ETDEWEB)

The gas-solid reaction and breakthrough curves in the fixed-bed reactor are of great importance, and being influenced by a number of factors makes the prediction of these factors a difficult problem. In this study, the reaction rate between solid sorbents and hydrogen chloride gas at high temperature was first investigated. On the basis of a fixed-bed reactor, the experimental results were analyzed by the shrinking core model of diffusion and surface chemical reaction control. The results showed that reaction rates of two sorbents with hydrogen chloride gas were controlled by the combination of the surface chemical reaction and diffusion of product layers, and the reaction rates nearly keep constant within 15 h of the initial reaction period and then decrease gradually. The results of the breakthrough curves show that solid sorbents in the ...

UK PubMed Central (United Kingdom)

Phenothiazine-N-carbonyl chloride inactivated chymotrypsin and trypsin by means of a 1:1 stoicheiometric reaction. Its reaction with chymotrypsin was 29 times as fast as that with...Full Text Available

International Nuclear Information System (INIS)

The measured result of charged multiplicity in cosmic-ray proton induced nuclear reaction from Chinese satellite emulsion is reported. The correlation of shower and heavy particles is discussed and compared with p-emulsion interactions.

Science.gov (United States)

Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 {mu}s exposure and spatial resolution of 10 {mu}m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were ...

Energy Technology Data Exchange (ETDEWEB)

The OH-initiated photo-oxidation of n-butane was used as a source of 1- and 2-butoxy radicals. Reactions producing ketones and other organic compounds are explained. Rates of photolysis were determined and are discussed.

International Nuclear Information System (INIS)

... isobaric analogs mev range 01-10 neutrons nuclear reactions nuclear theory

Energy Technology Data Exchange (ETDEWEB)

The high-energy reaction cross sections of Li and Be isotopes are calculated using a simplified Glauber model and densities constrained by the empirical binding energies. We find excellent agreement with experiment, reproducing the large increase for the most neutron-rich nuclei.

UK PubMed Central (United Kingdom)

A sensitive assay based on the polymerase chain reaction for the detection of Ockelbo virus RNA was developed. Two primer pairs from the gene coding for the E2 glycoprotein were chosen. By use of a...Full Text Available

UK PubMed Central (United Kingdom)

A high-throughput assay for enzyme activity has been developed that is reaction independent. In this assay, a small-molecule yeast three-hybrid system is used to link enzyme catalysis to transcription...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Disclosed are additives for hydrocarbon fuels which are the reaction products of a polyamine and an alkyl ester of acrylic or alkyl acrylic acid. A preferred composition is a mixture of the reaction product and oxygenated or non-oxygenated mono- or polyamines.

International Nuclear Information System (INIS)

... states gamma radiation mev range 01-10 photonuclear reactions polarization

Energy Technology Data Exchange (ETDEWEB)

'The interactions of carbon tetrachloride with strongly basic oxides and hydroxides have been studied by several techniques in order to understand the surface reactions and the subsequent bulk reactions that result in the destruction of the chlorinated hydrocarbon. Emphasis has been placed on understanding the surface phases, as well as the bulk phases, that are present during these transformations. As a result of the study with barium oxide, a reaction cycle has been demonstrated that may have practical significance in the removal of chlorinated hydrocarbons.'

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

... electron reactions electrons excitation inelastic scattering m1-transitions proton

International Nuclear Information System (INIS)

... atp-ase azido compounds biochemical reaction kinetics endoplasmic reticulum

International Nuclear Information System (INIS)

... range krypton 86 reactions molybdenum 92 target probability quasi-elastic

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

A fuel composition comprising a liquid hydrocarbon fuel and a detergent amount of the product of reaction between a polyamine and a stearic acid is described.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

... 98 target molybdenum 99 niobium 91 photoneutrons photonuclear reactions

Energy Technology Data Exchange (ETDEWEB)

The development of detailed chemical kinetic reaction mechanisms for analysis of autoignition and knocking of hydrocarbon fuels is described. In particular, kinetic processes of concern for the oxidation of complex hydrocarbon fuel molecules are emphasized. The wide ranges of temperature and pressure which are encountered by end gases in automobile engine combustion chambers result in extreme demands on reaction mechanisms which are intended to describe knocking conditions and predict rates of combustion and ignition. The reactions and chemical species which are most important in each temperature and pressure regime are discussed, and the validation of these reaction mechanisms through comparison with idealized experimental results is described. 53 refs., 8 figs., 5 tabs.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

A method for the calculation of excitation functions and isomer ratios, for shape isomers, in heavy ion induced reactions is proposed. The calculated values of excitation functions and isomer ratios agree very well with the experimental values for the reaction /sup 238/U(/sup 11/B, alpha 3n)/sup 242/Am. (auth)

Energy Technology Data Exchange (ETDEWEB)

Using the PMR method the interaction of zirconium and hafnium tetrachlorides with tri.tet.butylphenyl ester of 1,2- naphthoquinonediazide (2)-5-sulfonic acid is studied. The formation of MCl/sub 4/xNQD complexes is established, the equilibrium constants and thermodynamic parameters of complexing reaction are determined. The presence of rapid ligand exchange, proceeding according to associative mechanism, is detected. The rate constants and activation energies of the exchange reaction are calculated.

International Nuclear Information System (INIS)

The review is devoted to the use of ionic liquids as solvents, immobilized organocatalysts and reagents in reactions involving carbon acids and 1,3-dipoles, which are widely used to prepare practically valuable organic compounds of various classes. The characteristic features of processes in the presence of ionic liquids, the effects of the structure of cations and anions on the regio-, stereo- and enantioselectivities of reactions and methods of recovery of ionic liquids are considered.

Energy Technology Data Exchange (ETDEWEB)

The principle of operation of shaft furnaces is explained and demonstrated in four practical examples. The conditions and parameters determining coke conversion in the combustion zone and in the Boudouard reaction range are described. The combustion process is treated as a whole while the reduction process is discussed separately for the blast furnace, the cupola furnace, and the shaft furnace. The possibilities describing the Boudouard reaction as a function of the temperature level are discussed and consequences are derived for further experimental and theoretical studies.

International Nuclear Information System (INIS)

The reactions of alpha particles on natural abundance chromium have been studied between 40 and 110 MeV, in order to produce "5"2Fe for medical use. The yield of the reaction "5"2Cr(#alpha#,4n)"5"2Fe for Esub(#alpha#) = 85 #-># 53 MeV is only 30 #mu#Ci/#mu#Ah. (orig.).

International Nuclear Information System (INIS)

An 'electron-bridge' mechanism of nuclear reaction in an atom or ion by ultra-intense laser fields is presented. A preliminary estimate of the intensity dependence of the rate of disintegration reaction of deuteron nucleus in deuterium atom is made for 800 nm laser fields. For intensities below 5x1021 W/cm2, the rate of disintegration by the 'electron-bridge' mechanism is found to be small, but it rises sharply and becomes large already for ?1022 W/cm2.

Energy Technology Data Exchange (ETDEWEB)

This experiment is carried out in the series of the investigation on the damage mechanism of carbon steel. In this paper, the damage situation is considered by structure observations. The test were carried out in 600degC-1200degC temperature range, in blowing an argon gas. The reagents are Na{sub 2}O, Na{sub 2}O{sub 2} and NaOH. From structure observations, the holes are observed on the surface of iron-base material in some test conditions. This result is indicated that the selective reaction occurs. The selective reaction is more obvious as the time exposed to the high temperature is longer. It is considered that the selective reaction occurs after the chemical reaction between iron-base material and sodium compound. The areas, in which Mn-concentration is higher, are observed in products on the surface of specimen. (author)

Science.gov (United States)

In terms of the reduced potential energy barrier ? = ?uTS/kT, the rate coefficients for chemical reactions are usually expressed as proportional to e-?. The coupling between vibrational modes of the medium to the reaction coordinate leads to a proportionality of the regularized gamma function of Euler Q(a,?) = ?(a,?)/?(a), with a being the number of modes coupled to the reaction coordinate. In this work, the experimental rate coefficients at various temperatures for several chemical reactions were fitted to the theoretical expression in terms of Q(a,?) to determine the extent of its validity and generality. The new expression affords lower deviations from the experimental points in 29 cases out of 38 and it accounts for the curvature in the logarithmic plots of rate coefficients versus inverse temperature. In the absence of tunneling, conventional theories predict the curvature of these plots to be ...

Science.gov (United States)

Macrokinetics of benzene sulfonation in liquid-liquid and gas-liquid systems has been studied in continuous mixed reactors. It has been shown that the rate of sulfonation of benzene at 25/sup 0/C in two liquid phases using concentrated sulfuric acid is kinetically controlled. Whereas the rate of the latter reaction by gaseous sulfur trioxide at the same temperature is largely affected by the diffusional phenomena. At this temperature, the rate of reaction in gas-liquid system was described by a model assuming a fast reaction in the liquid phase. However, by increasing the temperature, the fast reaction region gradually changed to instantaneous reaction regime. A model, describing such a regime has also been developed and verified experimentally.

Energy Technology Data Exchange (ETDEWEB)

A detailed chemical kinetic reaction mechanism is developed to describe incineration of the chemical warfare nerve agent sarin (GB), based on commonly used principles of bond additivity and hierarchical reaction mechanisms. The mechanism is based on previous kinetic models of organophosphorus compounds such as TMP, DMMP and DIMP that are often used as surrogates to predict incineration of GB. Kinetic models of the three surrogates and GB are then used to predict their consumption in a perfectly stirred reactor fueled by natural gas to simulate incineration of these chemicals. Computed results indicate that DIMP is the only one of these surrogates that adequately describes combustion of GB under comparable conditions. The kinetic pathways responsible for these differences in reactivity are identified and discussed. The most important reaction in GB and DIMP that makes them more reactive than TMP or DMMP is found to be a ...

International Nuclear Information System (INIS)

The kinetics of the reactions between mixed powders of BaCO_3 and CuO, as well as BaCO_3 and Y_2O_3, have been studied using DXRD techniques as a function of particle size, temperature, and CO_2 pressure. Except for initial nucleation phenomena, the reaction rates are governed by shrinking core behavior for BaCO_3 particle sizes between 6 and 33 #mu#m. During the initial stages of the reactions, the surface reaction kinetics are governing, whereas the diffusion of CuO, Y_2O_3, and CO_2 are limiting factors at later stages in the reactions. Quantitative conversion data were used to determine the values of the activation energies and the pertinent diffusivities in these systems.

International Nuclear Information System (INIS)

Theoretical interpretation of fast-charged-particle spectra, observed in the #alpha#-particle-induced reactions on the s-d shell nuclei (A = 24-28), in terms of the Intranuclear Cascade Model and the GDH exciton model (ALICE) is presented. The de-excitation of the excited residual nuclei is accounted for by the evaporation process. The theoretically predicted fast-proton and #alpha#' spectral shapes compare reasonably well with the corresponding measured spectra. However, the magnitude depends critically (as expected) on the reaction cross section employed by the model. As a first step to improve the model predictability of the reaction products, a closer look at the calculation of the #alpha#-particle reaction cross sections was undertaken. A microscopic approach using the optical theorem of Glauber's theory was employed to estimate the #alpha#-induced reaction cross sections for ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: The aim of this study was to demonstrate the typical appearance of ganglioneuromas in computer-assisted tomography (CT), and magnetic resonance imaging (MRI). Material and methods: Retrospective analysis of diagnostic imaging (9 CT, 6 MRI) in 9 children aged 3 to 15 years with the histological diagnosis of ganglioneuroma. Results: The tomographies showed large (max. 13.4 cm in diameter) round or oval tumors with sharp delineation. The sites of the tumors were the retroperitoneum (5), the mediastinum (3), and the adrenal gland (1). Intraspinal tumor involvement occurred in 4 cases. On comparing CT with MRI, MRI was more accurate in defining the intraspinal involvement. The ganglioneuromas were of hypodense appearance in the native CT scan and showed moderate enhancement upon administration of contrast media. In five patients tumor calcifications with a disseminated sprinkled pattern were seen in CT. In MRI T{sub 1}-weighted scans the tumors were homogeneous ...

International Nuclear Information System (INIS)

The absolute cross sections of "2"3Na(p,n)"2"3Mg, "2"7Al(p,n)"2"7Si and "3"0Si(#alpha#,n)"3"3S reactions were measured in the incident energy range of 5.05 to 5.80, 5.80 to 6.25 and 3.975 to 6.235 MeV respectively using a spherically shaped 4#pi# neutron detector. In the energy range 5.80 to 7.80 and 6.235 to 11.30 MeV the absolute cross sections of "2"3Na(p,n)"2"3Mg and "3"0Si-(#alpha#,n)"3"3S reactions were determined by optical model calculations. The cross sections of the inverse reactions "2"3Mg(n,p)"2"3Na and "3"3S(n,#alpha#)"3"0Si were also calculated by the same method for the neutron energy range of 10 keV to 7.50 MeV for each reaction. The cross section of the latter reaction in the neutron energy range of 10 keV to 840 keV was also determined from its inverse reaction "3"0Si(#alpha#,n)"3"3S by the application of the detailed balance theorem. The ...

Energy Technology Data Exchange (ETDEWEB)

The studies of {sup 137}Cs and {sup 239+240}Pu distributions in surface seawater at South China Sea within the Exclusive Economic Zone (EEZ) of Peninsular Malaysia were carried out in June 2008. The analysis results will serve as additional information to the expanded baseline data for Malaysia's marine environment. Thirty locations from extended study area were identified in the EEZ from which large volumes of surface seawater samples were collected. Different co-precipitation techniques were employed to concentrate cesium and plutonium separately. A known amount of {sup 134}Cs and {sup 242}Pu tracers were used as yield determinant. The precipitate slurry was collected and oven dried at 60 {sup o}C for 1-2 days. Cesium precipitate was fine-ground and counted using gamma-ray spectrometry system at 661.62 keV, while plutonium was separated from other radionuclides using anion exchange, electrodeposited and counted using alpha spectrometry. The activity ...

Energy Technology Data Exchange (ETDEWEB)

The particulate matter of a light-duty diesel engine was characterized in its morphology, sizes, internal microstructures, and fractal geometry. A thermophoretic sampling system was employed to collect particulates directly from the exhaust manifold of a 1.7-liter turbocharged common-rail direct-injection diesel engine. The particulate samples collected at various engine-operating conditions were then analyzed by using a high-resolution transmission electron microscope (TEM) and an image processing/data acquisition system. Results showed that mean primary particle diameters (dp), and radii of gyration (Rg), ranged from 19.4 nm to 32.5 nm and 77.4 nm to 134.1 nm, respectively, through the entire engine-operating conditions of 675 rpm (idling) to 4000 rpm and 0% to 100% loads. It was also revealed that the other important parameters sensitive to the particulate formation, such as exhaust-gas recirculation (EGR) rate, equivalence ratio, and temperature, affected ...

International Nuclear Information System (INIS)

In the early period after the Chernobyl accident, analysis of patterns of "1"3"1I exposure of the human thyroid showed that contaminated milk was the basic source of "1"3"1I intake among the inhabitants of Russia. The equipment and techniques used for measurement of the "1"3"1I content in the thyroids of these individuals are described in this work. A model of the "1"3"1I intake, taking into account protective actions, and a method of thyroid dose calculation are discussed. The mean thyroid dose and frequency distributions of the thyroid doses to inhabitants of towns and villages of the Bryansk, Tula and Orel regions of Russia are presented. The mean dose to the thyroids of children living in the villages was 2 to 5 times higher than the dose to adult thyroids; for children living in the towns, the mean dose was 1.5 to 12 times higher. The mean thyroid mass in adult inhabitants of the Bryansk region was 27 g, which exceeded the value for a standard man (20 g) and was taken into account ...

International Nuclear Information System (INIS)

In the present paper, experimental study of forced convection boiling were performed to investigate the post-CHF characteristics of a vertical annular channel with one heated rod and four spacer grids for new refrigerant R-134a. The experiments were conducted under outlet pressure of 11.6, 13, 16 and 20 bar, mass fluxes of 100-600 kg/m2s, and inlet temperatures of 25-51 .deg. C. The parametric trend of the post-CHF data was well consistent with previous studies. The two phase flow regime in tube flow occurring downstream of the CHF has been called post-CHF, dispersed flow, liquid-deficient flow, mist flow and film boiling. This regime is characterized by a continuous vapor phase with discrete liquid drops and a non-wetted heated surface. This regime has a considerable importance in the areas of light water reactor(LWR) accident analysis and other film boiling applications. The post-CHF region occurs by design in heat exchangers operating in the once-through mode ...

International Nuclear Information System (INIS)

An outline of Manitoba Hydro's Earth Power program was presented. Details of the heat pump market in Manitoba were provided, including details of residential and commercial sales. Total residential heat pump sales amounted to 577 units in 2004, equivalent to over $11.2 million in sales. Commercial installations amounted to approximately $12.7 million. An outline of industry players was presented. The goals of Manitoba Hydro were outlined in relation to geothermal energy and the Power Smart program. Their objectives included increasing awareness of geothermal energy, making heat pumps more accessible, and improving industry infrastructure. Other objectives included educating the public about life-cycle cost implications, residential loans and commercial incentives. To date, the residential power loan has provided financing to over 300 Manitoba home owners for installations, with electrical savings of over 1.34 Gwh and natural gas savings of 279,425 m"3. The program ...

Energy Technology Data Exchange (ETDEWEB)

A massively-parallel ab initio computer code, which uses Gaussian bases, pseudopotentials, and the local density approximation, permits the study of transition-metal systems with literally hundreds of atoms. We present total energies and relaxed geometries for Ru, Pd, and Ag clusters with N = 55, 135, and 140 atoms; we also used the DMOL code to study 13-atom Pd and Cu clusters, with and without hydrogen. The N = 55 and 135 clusters were chosen because of simultaneous cubo-octahedral (fcc) and icosahedral (icos) sub-shell closings, and we find icos geometries are preferred. Remarkably large compressions of the central atoms are observed for the icos structures (up to 6% compared with bulk interatomic spacings), while small core compressions ({approx} 1 %) are found for the fcc geometry. In contrast, large surface compressive relaxations are found for the fcc clusters ({approx} 2-3% in average nearest neighbor spacing), while the icos surface displays small compressions ({approx} 1%). ...

International Nuclear Information System (INIS)

A 12 m.y. record of large rhyolitic eruptions from the Coromandel (CVZ) and Taupo (TVZ) volcanic zones of New Zealand is contained in cores retrieved by Leg 181 of the Ocean Drilling Program. Site 1124, located 670 km from the TVZ, has a maximum of 134 macroscopic tephra layers with a total thickness of 13.18 m. These units, along with between 7 and 63 tephras from 3 other sites, were dated by a combination of magnetostratigraphy, biostratigraphy, isothermal plateau fission track determinations, and geochemical correlation with onshore tephra deposits. Additional time control for the last 3 m.y. came from an orbitally tuned, benthic, oxygen isotope profile for Site 1123. Results extend the incomplete terrestrial record of volcanism by placing the first major rhyolitic eruption in the CVZ at c. 12 Ma, c. 1.6-1 m.y. earlier than previously known. Tephras became thicker and more frequent from the late Miocene into the Quaternary - a trend that probably reflected (1) ...

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Organic Rankine cycles (ORC) have unique properties that are well suited to solar power generation. In this work design and performance calculations are performed using MatLab/SimuLink computational environment. The cycle consists of thermal solar collectors (Flat Plate Solar Collector (FPC), or Parabolic Trough Collector (PTC), or Compound Parabolic Concentrator (CPC)) for heat input, expansion turbine for work output, condenser unit for heat rejection, pump unit, and Reverse Osmosis (RO) unit. Reverse osmosis unit specifications used in this work is based on Sharm El-Shiekh RO desalination plant. Different working fluids such as: butane, isobutane, propane, R134a, R152a, R245ca, and R245fa are examined for FPC. R113, R123, hexane, and pentane are investigated for CPC. Dodecane, nonane, octane, and toluene are allocated for PTC. The proposed process units are modeled and show a good validity with literatures. Exergy and cost analysis are performed for saturation ...

Energy Technology Data Exchange (ETDEWEB)

In the future, the demand for energy is predicted to grow and more countries plan to utilize nuclear energy as their source of electric energy. This gives rise to many important issues connected to nuclear energy, such as finding methods that can verify that the spent nuclear fuel has been handled safely and used in ordinary power producing cycles as stated by the operators. Gamma ray spectroscopy is one method used for identification and verification of spent nuclear fuel. In the specific gamma ray spectroscopy method called gamma scanning the gamma radiation from the fission products Cs-137, Cs-134 and Eu-154 are measured in a spent fuel assembly. From the results, conclusions can be drawn about the fuels characteristics. This degree project examines the possibilities of using alternative measuring approaches when using the gamma scanning method. The focus is on examining how to increase the quality of the measured data. How to decrease the measuring time as ...

International Nuclear Information System (INIS)

In this experiment, we measured the detection efficiency of gamma-scanning system of Irradiated Materials Examination Facility (IMEF) in Korea Atomic Energy Research Institute(KAERI) for the spent PWR fuel and activity known sources with high activity. We measured the absolute detection efficiency of gamma scanning system of IMEF to the "1"3"7Cs-source with 10.4 GBq and "6"0Co source with 25.9 GBq High-activity sources as standard sources, and a fuel burned in the KORI -1 reactor of the Kori Nuclear power plant. In analyzing, we used three peeks those were the 661.64 keV peak form "1"3"7 Cs 1173.23 and 1332.51 keV"6"0 Co sources, and 14 peaks of "1"3"4Cs and "1"5"4Eu on the spent fuel gamma spectrum which are in the energy range from 500 to 1,600 keV. We find second order equations for detection efficiency by using our experimental results. The equation show that the detection efficiency of gamma scanning system for 1 MeV gamma-ray is 2.82217x10"-"6 % for the C3 ...

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The effect of adriamycin in combination with radiation on the skin reactions of mouse feet has been examined under a variety of experimental conditions including: (a) hyperthermic treatment of the foot immediately following adriamycin administration, with the former given either just before or just after x irradiation, and (b) fractionated treatments of drug and radiation in a variety of sequences over an 18-day period. In the case of the most severe hyperthermic treatment, no increased radiation reactions were observed in the presence of adriamycin. However, in the case of the less severe hyperthermic treatment a small but significant increase in skin reactions was observed. In the study of fractionated drug and radiation treatments, an enhancement of reaction in those animals receiving combined modality treatment over those receiving radiation alone was seen in those groups where the initiation of ...

Science.gov (United States)

Enzymatic reactions in non-aqueous media have been shown to be effective in carrying out chemical transformation where the reactants are insoluble in water or water is a byproduct limiting conversion. Ionic liquids, liquid organic salts with infinitesimal vapor pressure, are potentially useful alternatives to organic solvents. It is known that the thermodynamic water activity is an important variable affecting the activity of enzymes in non-aqueous solvents. This study investigated the influence of water activity on the esterification of geraniol with acetic acid in ionic liquid [bmim]PF6 catalyzed by immobilized Candida antarctica lipase B. The conversion of geraniol in [bmim]PF6 was significant although the reaction rate was slower than in organic solvents. The profile of initial reaction rate-water activity was determined experimentally, and differed from the data reported for other non-aqueous solvents. A maximum in the ...

International Nuclear Information System (INIS)

Experimentally investigated nuclear reactions for production of no-carrier-added "7"7Br and "7"7Kr were critically surveyed. The survey covered nine reactions for the formation of "7"7Br and six reactions for "7"7Kr. Both radionuclides are simultaneously produced in many of the studied nuclear processes. The experimental data were compared with the results of nuclear model calculations based on the computer code ALICE-IPPE and the third version of TALYS-based Evaluated Nuclear Data Library, TENDL-2010. Good agreement was found over extended energy regions for the p-, "3He- and #alpha#-particle induced reactions on several target materials. In case of d-induced reactions, however, considerable discrepancies were noted between the experimental and theoretical data. The concordant sets of experimental cross section data for each reaction were fitted by a polynomial ...

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The reactions of native bovine catalase with superoxide and solvated electrons have been investigated using three different methods for generating these reducing substrates: [gamma]-radiolysis of oxygenated or deaerated buffer solutions in the presence of an OH radical scavenger; either xanthine or acetaldehyde with xanthine oxidase; and low-temperature (77 K) [gamma]-radiolysis of buffered ethylene glycol/water solutions with subsequent annealing of samples at 183 K. (Author).

International Nuclear Information System (INIS)

Geochemical model is a kind of concept model which describes geochemical processes by means of chemical reaction equations and mathematical formula, and the software based on the concept model are called geochemical modeling code. Geochemical modeling codes can be divided into three categories: mass equilibrium, mass transfer and mass transport code. The major functions of geochemical codes include the calculation of forms of occurrence of elements, the prediction of direction of various geochemical reaction, the dissolution and precipitation of elements, the pH and Eh value, the rate and path of geochemical reaction in aqueous solution.

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Nuclear reaction cross-sections for stable strontium and cesium isotopes, which were calculated by different approaches, are compared to available experimental data. Neutron and proton induced reaction cross-sections for the long-lived radionuclides [sup 90]Sr and [sup 137]Cs have been calculated in the energy range from 1 MeV to 10 GeV. Recommendations concerning cross-section calculations for strontium and cesium isotopes at intermediate and high energies are given. (orig.)

International Nuclear Information System (INIS)

The constants, applied in the phenomenological approaches for describing the nuclear reactions with the high transmitted pulse, are obtained within the frames of the multiquark flucton microscopic model. The constants values prove to be universal for all the nuclei and independent on the collision energy and flucton properties (excluding its mass), i.e. the peculiar scaling is manifested in the reaction cross sections. The theoretically obtained values of these constants are in good agreement with the phenomenological values, derived from the (p, p'X) reaction cross sections on the nuclei for X=d, t, "3He

British Library Electronic Table of Contents (United Kingdom)

Predicted by stochastic models and observed experimentally in a number of isomerization reactions, viscosity-induced solvent effects manifest themselves in a significant departure of the reaction rates from the values expected on the basis of transition state theory. These effects are well understood within the framework of stochastic models; however, the predictive power of such models is limited by the fact that their parameters are not readily available. Experiment and molecular dynamics (MD) simulations can provide such information and can serve as the testing grounds for various stochastic models. In real solvents, a change in viscosity is inevitably associated with variation of at least one of the three factors - temperature, pressure, or solvent identity, resulting in different solv...

British Library Electronic Table of Contents (United Kingdom)

A 60-year-old male was bitten by a venomous snake (Vipera ammodytes) and gradually developed signs of an allergic reaction including generalized itching, generalized rash, and chest discomfort. This was followed by severe retrosternal pain with electrocardiographic evidence of an inferior myocardial ischemia progressing to acute myocardial infarction. Cardiac enzymes and troponin, serum tryptase, and histamine were elevated. Coronary arteriography showed normal coronary arteries. This is a characteristic type I variant of Kounis syndrome, which is the concurrence of acute coronary syndromes with conditions associated with mast cell activation including allergic or hypersensitivity reactions as well as anaphylactic or anaphylactoid reactions. This is the first report to show that viper bite...

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Two patients are described in whom sunburn and electron beam radiodermatitis, respectively, were critical determinants in localizing the initial presentation of drug eruptions. In the first instance, a severe sunburn of the back and thighs was followed 7 months later by the appearance of a toxic epidermal necrolysis drug reaction to trimethoprim-sulfamethoxazole in the exact sites of the previous bullous sunburn reaction. In the second patient, a radiodermatitis of the left upper arm due to electron beam therapy for metastatic breast cancer was followed 7 weeks later by a codeine drug reaction confined to the area of the radiodermatitis. In both instances, oral rechallenge with the offending drug reproduced the eruption.

International Nuclear Information System (INIS)

In the reactions induced by heavy ions, the study of breakup of heavy ions followed by the fusion of one of the fragments with the target has been of great interest. The present experiments has been performed with a view to compare the measured excitation functions for the same decay channels in "1"2C + "1"6"5Ho and "1"4N + "1"6"3Dy systems

International Nuclear Information System (INIS)

Monte Carlo criticality calculations have been performed for over 50 years for reactor physics and criticality safety applications. With today's faster computers, these calculations are being carried out to greater precision (smaller uncertainties) in keff, and detailed distributions of power and reaction rates are being computed routinely. This paper provides a review of the fundamental theory of Monte Carlo criticality calculations, with guidance on practical methods for: (1) assuring convergence of both keff and the source distribution, (2) minimizing the bias in keff and reaction rate distributions, and (3) dealing with the under-prediction bias in uncertainties for keff and reaction rate distributions. (authors)

International Nuclear Information System (INIS)

... ammonium compounds antigen-antibody reactions hemoglobin inhibition

Science.gov (United States)

... A. Ferrero. 2000. Escape behaviour in the stomatopod crustacean Squilla mantis, and the evolution of the caridoid escape reaction. ... ...

British Library Electronic Table of Contents (United Kingdom)

Introduction.Microfluidic technology allows fast reactions in a simple experimental setup, while using very low volumes and amounts of starting material. Consequently, microfluidic technology is an ideal tool for radiolabeling reactions involving short-lived positron emitters. Optimization of the complex array of different reaction conditions requires knowledge of the different reaction parameters linked to the microfluidic system as well as their influence on the radiochemical yields. 1-(5-Deoxy-5-fluoro-?-d-arabinofuranosyl)-2-nitroimidazole ([18F]FAZA) is a frequently used radiotracer for PET imaging of tumor hypoxia. The present study describes the radiosynthesis of [18F]FAZA by means of microfluidic technology and subsequent small animal PET imaging in EMT-6 tumor-bearing mice.Methods...

Energy Technology Data Exchange (ETDEWEB)

The nitrogen content of 10 medicinal plant species has been determined by fast-neutron activation analysis (FNAA). Correction factors for the effects of the /sup 16/O(p,..cap alpha..)/sup 13/N knock-on proton-induced reaction and the (n,2n) reactions, which produce interfering positron-emitting radionuclides, have also been determined. The total relative interference from the /sup 16/O(p,..cap alpha..)/sup 13/N and (n,2n) reactions of K, Cl, Fe and Br was found to be 5.1 to 32.1% for the plant samples.

International Nuclear Information System (INIS)

... base alloys alloys beams chemical reactions elements hardness irradiation

International Nuclear Information System (INIS)

We report here results of an application of single-nucleon stripping reactions at high energies (65 MeV/u) in inverse kinematics to obtain spectroscopic factors. From measurements of the partial cross-sections for ground and excited states in residual nuclei formed in one-proton stripping reactions, single particle orbits and occupancies of light nuclei have been studied in the s-d shell. Single proton stripping cross-sections of "2"5Al and "2"6","2"7","2"8P on a Be target have been measured using the S800 spectrograph and the NaI(Tl) array at the NSCL. These results indicate that this technique may provide a general tool for the intermediate energy range analogous to transfer (pick-up) reactions at low-energy.

Energy Technology Data Exchange (ETDEWEB)

Here we report a new method for measuring the heterogeneous chemistry of submicron organic aerosol particles using a continuous flow stirred tank reactor. This approach is designed to quantify the real time heterogeneous kinetics, using a relative rate method, under conditions of low oxidant concentration and long reaction times that more closely mimic the real atmosphere. A general analytical expression, which couples the aerosol chemistry with the flow dynamics in the chamber is developed and applied to the heterogeneous oxidation of squalane particles by hydroxyl radicals (OH) in the presence of O2. The particle phase reaction is monitored via photoionization aerosol mass spectrometry and yields a reactive uptake coefficient of 0.51+-0.10, using OH concentrations of 1-7x108 molec cdot cm-3 and reaction times of 1.5+-3 hours. This uptake coefficient is larger than that found for the reaction carried ...

Science.gov (United States)

The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom, or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range of 300 to 1000 K and pressure range of 1 to 10 Torr. The ...

Energy Technology Data Exchange (ETDEWEB)

Several reactions producing odd-Z transactinide compound nuclei were studiedwith the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the LawrenceBerkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via differentnuclear reactions. In doing so, it can be determined if there is a preference in entrancechannel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's"Fusion By Diffusion" model is nearly identical forthe two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one ...

International Nuclear Information System (INIS)

Nuclear reaction rates and opacity are important parameters in stellar evolution. The input physics in a stellar evolution code determines the main theoretical characteristics of the stellar structure, evolution and nucleosynthesis of a star. For different input physics, in this work we calculate stellar evolution models of very massive first stars during the hydrogen and helium burning phases. We have considered 100 and 200M_sun galactic and pregalactic stars with metallicity Z = 10"-"6 and 10"9, respectively. The results show important differences from old to new formulations for the opacity and nuclear reaction rates, in particular the evolutionary tracks are significantly affected, that indicates the importance of using up to date and reliable input physics. The triple alpha reaction activates sooner for pregalactic than for galactic stars.

Energy Technology Data Exchange (ETDEWEB)

Detailed level and decay schemes are presented for the nuclei of the A = 101 mass chain. The level properties obtained from decay and reaction experiments are shown in the drawings. Experimental methods, references, and comments are given in the text.

International Nuclear Information System (INIS)

The energy level schemes of tin isotopes produced in the heavy ion reactions are presented. The using of #gamma# spectroscopy technique is also described. 4 refs, 12 figs.

International Nuclear Information System (INIS)

Neutron yield from the "6","7Li + d reaction has been investigated. The results obtained are compared with the published data with some theoretical models.

UK PubMed Central (United Kingdom)

Monitoring describes the prospective supervision, observation, and testing of an ongoing process. The result of monitoring provides reassurance that the goal has been or will be achieved, or suggests...Full Text Available

International Nuclear Information System (INIS)

... minutes living radioisotopes nuclear reactions nuclei nucleons odd-odd nuclei

Science.gov (United States)

1 The Elemental Fuel Cell Model. The cell reactions are also illustrated in. Figure 1. Hydrogen is oxidized at the anode. Oxy- ...

Science.gov (United States)

... 0.2 ml each were taken. The reaction was stopped by the addition of 1 ml LO% trichloracetic acid (TCA) in 0.1 mole of pyrophosphate ...

British Library Electronic Table of Contents (United Kingdom)

Purpose - This paper discusses the impact of aesthetic design of smartphones on users' emotional reactions and preferences towards the product. To this end, the paper presents a study that explores emotional reaction of males to varying aesthetic design of the BlackBerry and empirically evaluates their preferences for the BlackBerry in different colours and overlay patterns. The paper then presents the statistical results of the study in an innovative graphical representation. Design/methodology/approach - A quantitative and qualitative research design was used, including three types of data-collection instruments (direct observations, rating scales, and interviews) to investigate if males have a stronger positive emotional reaction for visually treated BlackBerry Pearl devices over the or...

International Nuclear Information System (INIS)

... filters molybdenum alloys production sulfuric acid alloys chemical reactions ...

British Library Electronic Table of Contents (United Kingdom)

The atmospheric processing by ozone of peptide-containing mixed particles was investigated as proxies for biogenic and sea spray primary organic aerosol. Reactions were performed in a flow reactor and particle composition was monitored by photoelectron resonance capture ionization aerosol mass spectrometry. Mixed particles containing dipeptides in a saturated organic matrix of stearic and palmitic acids showed no reaction under ozonolysis at exposure levels of 2.5???10?4?atm s O3. However reactions of mixed particles of a dipeptide (Leu-Leu) in an unsaturated matrix (oleic acid) under the same conditions resulted in a rapid loss of the peptide ion signal, as well as the carrier matrix, and appearance of a number of ion signals corresponding to secondary products. High molecular weight imid...

UK PubMed Central (United Kingdom)

BackgroundOsseointegration is crucial for the long-term success of dental implants and depends on the tissue reaction at the tissue-implant interface. Mechanical properties and biocompatibility...Full Text Available

UK PubMed Central (United Kingdom)

Chemically reactive compounds in tissues can be monitored through their products of reaction with biomacromolecules. For the purpose of in vivo dose monitoring, hemoglobin (Hb) has been preferred to...Full Text Available

International Nuclear Information System (INIS)

Measurements are made of the isomeric ratio for the (n,2n) and (#betta#,n) reactions on the neutron-deficient nuclei _9_2Mo, _9_0Zr, _8_6Sr and _7_4Se. A method is developed for calculating the isomeric ratio for a low excitation energy of the residual nucleus. The good agreement found between experimental results and calculations for the (#betta#,n) reaction confirms the choices of residual nucleus characteristics, transmission coefficients of neutrons emitted etc. used in the calculations. The results of a study of the (n,2n) reaction were used to find the spin dependences of nuclear level density in the excitation energy region approx. 14 MeV. (author).

UK PubMed Central (United Kingdom)

SummaryA microreactor for electrochemical synthesis has been designed and fabricated. It has been shown that different reactions can be carried out successfully using simple protocols.

British Library Electronic Table of Contents (United Kingdom)

The work is devoted to a microscopic analysis of the reactive capacity of chitin. An algorithm for modeling the deacetylation reaction in a monomeric unit of chitin is described. The reaction coordinate and the potential energy surface topography are determined taking into account the electron-vibrational interaction and low-symmetry perturbations within Jahn-Teller theory. Based on this algorithm, the topological modeling of the deacetylation process is performed for the first time and a mechanism of the biological activity of chitosan is proposed.

Energy Technology Data Exchange (ETDEWEB)

An investigation of the mechanism of the oxidation and ammoxidation of propylene was made. The products of the above reactions were acrylonitrile and acrolein for ammoxidation and oxidation, respectively. Also, the ammoxidation and oxidation of allyl alcohol, allyl amine, and their allylic deuterium substituted analogues was studied. It was concluded that oxidation and ammoxidation of propylene have the same rate determining step. Other conclusions about the reaction intermediates were also made.

International Nuclear Information System (INIS)

The status of neutron activation cross sections for some threshold reactions important for reactor materials dosimetry is reviewed. An attempt is made to understand and explain discrepancies between integral and differential data, using recent available experimental results. The importance of standard and benchmark neutron fields for testing differential data for reactor dosimetry is emphasized and the Interlaboratory Reaction Rate (ILRR) program, as well as a similar program pursued by the IAEA, are briefly described.

Energy Technology Data Exchange (ETDEWEB)

Calorimetry testing of Tri-n-butyl phosphate (TBP) saturated with strong nitric acid was performed to determine the relationship between vent size and pressure buildup in the event of a runaway reaction. These experiments show that runaway can occur in an open system, but that even when runaway is induced in the TBP/HN0{sub 3} system, dangerous pressure buildup will be prevented with practical vent size.

Energy Technology Data Exchange (ETDEWEB)

Reaction kinetics for the displacement of 5-aminoquinoline (5-Aq) and diethyl sulfide (SEt{sub 2}) from cis-[PtPh{sub 2}(CO)(L)] (L = 5-Aq or SEt{sub 2}) by aliphatic amines was measured for a wide array of amines. Reaction products were characterized by IR and NMR spectroscopies and crystalk structures of selected products were reported. Steric effects on the substitutions were discussed.

Energy Technology Data Exchange (ETDEWEB)

To simulate the effects of the breakup channel on rearrangement amplitudes, the conventional coupled-reaction-channel (CRC) expansion is augmented by pseudoreaction channels. The construction of the projector for the extended CRC space is discussed, and transition-operator equations on this space are given. By solving the full and post-approximation forms of the CRC equations for a model three-particle problem, the crucial role played by the nonorthogonality terms is demonstrated.

Energy Technology Data Exchange (ETDEWEB)

The mechanism of chemical poisoning of model heterogeneously catalyzed reactions on transition metal surfaces is studied. Clean Mo(001) surfaces were characterized; results suggest a first-layer contraction of 10% of the bulk interlayer spacing. Characterization of clean Co(0001) surfaces is underway. Decomposition of formic acid on Mo(001) surfaces is being studied. (DLC)

Energy Technology Data Exchange (ETDEWEB)

The change of the transport coefficient due to the fusion energy source is studied. The scale invariance property of the reduced set of equations is investigated in the presence of the self-heating term due to the fusion reaction. The pressure gradient as well as the fusion power are the free energy sources that dictate the turbulent transport. It is shown that the burning transport coefficient can have a form with much wider variety, and that the transport property could be different owing to the self-heating by the fusion reactions. (author)

International Nuclear Information System (INIS)

Transient enhanced diffusion in boron-implanted silicon is interpreted as being due to the fact that during rapid thermal annealing a relaxation process takes place, associated with quasi-chemical reactions including defects. A simple analytical model makes it possible to describe the annealing mechanism on a microscopic scale in terms of reaction-diffusion processes. The measured dependences of the boron diffusion coefficient of the enhanced diffusion on time, temperature and implantation energy are satisfactorily explained. (author).

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Projectilelike fragments following the 80 MeV /sup 16/O+/sup 27/Al reaction have been detected using a Bragg-curve spectroscopy ionization chamber (BCS-IC). The atomic number is deduced from the Bragg-peak amplitude. Nitrogen isotopes are clearly resolved using either range or energy loss data. This is the first application of the BCS method for complete ion identification in a heavy-ion-induced reaction.

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A method and apparatus is provided for detecting explosives by thermal imaging. The explosive material is subjected to a high energy wave which can be either a sound wave or an electromagnetic wave which will initiate a chemical reaction in the explosive material which chemical reaction will produce heat. The heat is then sensed by a thermal imaging device which will provide a signal to a computing device which will alert a user of the apparatus to the possibility of an explosive device being present.

International Nuclear Information System (INIS)

Levels in "7"2Se were observed via in-beam gamma spectroscopy following the "5"8Ni("1"6O,2p) reaction. Spectra and partial energy level schemes are shown. (3 figures) (U.S.).

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the reaction of zirconium phosphates with carbon tetrachloride in sodium and potassium chloride melt as well as the effect of temperature, gas flow, solubility and weight of the solid phase of the phosphate, and stirring of the melt on the chlorination rate has been studied. The kinetic parameters of the reaction (rate constants, activation energy, etc.) have been calculated.

Energy Technology Data Exchange (ETDEWEB)

In studying the absorption of carbon dioxide by absorbents impregnated with alkanol amines, researchers used a laboratory-scale packed column to determine the overall gas-phase mass-transfer coefficients and enhancement factors. A model derived for the mechanism of the chemical reaction taking place in the interfacial layer accounts for the effect of the reaction upon the absorption rate better than other models.

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Standard SCR catalysts possess high activity for the hydrolysis of HNCO and thus explain the suitability of urea as a selective reducing agent for NO{sub x}. At high space velocities HNCO-slip can get perceptible over the entire temperature range. This can be attributed to the fact that the temperature dependence is strong for the SCR reaction, but weak for the hydrolysis reaction. (author) 3 figs., 5 refs.

International Nuclear Information System (INIS)

We study the dynamics of scroll vortices in excitable reaction-diffusion systems analytically and numerically. We demonstrate that intrinsic three-dimensional instability of a straight scroll leads to the formation of helicoidal structures. This behavior originates from the competition between the scroll curvature and unstable core dynamics. We show that the obtained instability persists even beyond the meander core instability of the two-dimensional spiral wave. copyright 1998 The American Physical Society.

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An experiment to synthesize element 110 by the {sup 59}Co+{sup 209}Bi reaction has bee performed at the SuperHILAC at the Lawrence Berkeley Laboratory. One event with many of the expected characteristics of a successful of {sup 267}110 was observed. This event corresponds to a production cross section of about one picobarn.

UK PubMed Central (United Kingdom)

The enzyme indol-3-ylacetylglucose synthase (UDP-glucose:indol-3-ylacetate beta-D-glucosyltransferase) catalyses the reaction: [formula: see text] This is the first step in the series of reactions leading...Full Text Available

UK PubMed Central (United Kingdom)

A ligase chain reaction assay based on a single-base-pair difference in the V9 region of the 16S rRNA gene (16S rDNA) was developed to distinguish between Listeria monocytogenes and other Listeria species....Full Text Available

UK PubMed Central (United Kingdom)

A two-step polymerase chain reaction (PCR) procedure with two nested pairs of primers specific for the yadA gene of Yersinia enterocolitica was developed. The PCR assay identified all common pathogenic...Full Text Available

International Nuclear Information System (INIS)

The experimental has been performed with a view to studying complete and incomplete fusion in "1"4N + "1"6"3D_y system below 7 MeV/nucleon. The excitation functions for several reactions have been measured using the activation technique and compared with the theoretical predictions based on statistical models. The codes ALICE-91 and CASCADE used earlier for the analysis of excitation functions in case of "1"2C + "1"6"5H_0 system have been used here also with the same set of input parameters. It has been observed that the theoretical calculations do not match with the experimental excitation functions well but the overall shape of the excitation function is reproduced satisfactorily. The composite nucleus ("1"7"7T_a) formed in this ("1"4N + "1"6"3D_y) case is the same as the one formed in "1"2C + "1"6"5H_0 system studied earlier. Measured excitation functions for the same decay channels in the two cases (i.e. "1"2C + "1"6"5H_0 and "1"4N + "1"6"3D_y) have been ...

Energy Technology Data Exchange (ETDEWEB)

Chemical looping combustion (CLC) of simulated coal-derived synthesis gas was conducted with NiO oxygen carriers supported on SiO2, ZrO2, TiO2, and sepiolite. The effect of H2S on the performance of these samples for the CLC process was also evaluated. Five-cycle thermogravimetric analysis (TGA) tests at 800 C indicated that all oxygen carriers had a stable performance at 800 C, except NiO/SiO2. Full reduction/oxidation reactions of the oxygen carrier were obtained during the five-cycle test. It was found that support had a significant effect on reaction performance of NiO both in reduction and oxidation rates. The reduction reaction was significantly faster than the oxidation reaction for all oxygen carriers, while the oxidation reaction is fairly slow due to oxygen diffusion on NiO layers. The reaction profile was greatly affected by the presence of H2S, but ...