WorldWideScience
1

Pentaquark Searches at CDF  

Energy Technology Data Exchange (ETDEWEB)

Experimental results of a search for the {Xi}{sub 3/2}(1860) cascade pentaquark state in data collected with the CDF 2 Detector in Run II at the Tevatron are presented. No evidence for these states in the neutral {Xi}{sup -}{pi}{sup +} and doubly charged {Xi}{sup -}{pi}{sup -} modes has been found. Preliminary upper limits on yields at 1862 MeV/c{sup 2} relative to the well established resonance {Xi}*(1530){sup 0} are presented.

2004-08-26

2

Complex Gradient Systems  

CERN Document Server

Let $M$ be a complex manifold of complex dimension $n+k$. We say that the functions $u_1,...s,u_k$ and the vector fields $\\xi_1,...,\\xi_k$ on $M$ form a \\emph{complex gradient system} if $\\xi_1,...,\\xi_k,J\\xi_1,...,J\\xi_k$ are linearly independent at each point $p\\in M$ and generate an integrable distribution of $TM$ of dimension $2k$ and $du_\\alpha(\\xi_\\beta)=0$, $\\d^c\\u_\\alpha(\\xi_\\beta)=\\delta_{\\alpha\\beta}$ for $\\alpha,\\beta=1,...,k$. We prove a Cauchy theorem for such complex gradient systems with initial data along a $\\CR-$submanifold of type $(\\CRdim,\\CRcodim)$. We also give a complete local characterization for the complex gradient systems which are \\emph{holomorphic} and \\emph{abelian}, which means that the vector fields $\\xi_\\alpha^c=\\xi_\\alpha-J\\xi_\\beta$, $\\alpha=1,...,k$ are ...

2011-01-01

3

Random motion of a particle emitting and absorbing tachyons  

International Nuclear Information System (INIS)

Random motion of a particle, emitting and absorbing tachyons, is investigated. It is shown that if bradyon is in equilibrium with neutral gas, i.e. it absorbs and emits tachyons, which do not have any charges, tha particle with each absorption-emittance of a tachyon changes its energy and momentum, never varying its own mass, and as a result it moves like a brownian particle. Thus, bradyon, interacting with tachyon gas, increases its momentum continuously in agreement with the Einstein-Fokker-Planck type equation.

4

Three-dimensional particle simulation of plasma instabilities and collisionless reconnection in a current sheet  

Energy Technology Data Exchange (ETDEWEB)

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

1999-06-01

5

CHARACTERIZATION OF DEXTRIN PREPARED BY COMMON NEUTRAL AND THERMOSTABLE a-AMYLASES  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT With corn starch as raw material, dextrin was prepared by the combined application of common neutral and thermostable a-amylases in this study. The effects of reaction temperature, reaction time, addition of common neutral and thermostable a-amylases on dextrose equivalent (DE)-value of dextrin were investigated. The obtained dextrin with a DE value of 20.43 was evaluated for morphology, crystallography, particle size distribution and thermal property by scanning electron microscope, X-ray diffractometer, light scattering particle size analyzer and thermogravimetric analyzer. The results showed that the amorphous regions in the core part of corn starch were completely hydrolyzed and only the fractured crystalline surface remained. The particle size of the dextrin change significan...

2010-01-01

6

Weibel and Two-Stream Instabilities for Intense Charged Particle Beam Propagation through Neutralizing Background Plasma  

Energy Technology Data Exchange (ETDEWEB)

Properties of the multi-species electromagnetic Weibel and electrostatic two-stream instabilities are investigated for an intense ion beam propagating through background plasma. Assuming that the background plasma electrons provide complete charge and current neutralization, detailed linear stability properties are calculated within the framework of a macroscopic cold-fluid model for a wide range of system parameters.

2004-04-09

7

First measurements of J/Psi decays into $\\Sigma^+ \\bar{\\Sigma}^-$ and $\\Xi^0 \\bar{\\Xi}^0$  

CERN Document Server

Based on 58 million J/Psi events collected with the BESII detector at the BEPC, the baryon pair processes J/Psi to $\\Sigma^+ \\bar{\\Sigma}^-$ and J/Psi to $\\Xi^0 \\bar{\\Xi}^0$ are observed for the first time. The branching fractions are measured to be ${\\cal B}(J/Psi to \\Sigma^+ \\bar{\\Sigma}^-)=(1.50\\pm 0.10\\pm 0.22)\\times 10^{-3}$ and ${\\cal B}(J/Psi to \\Xi^0 \\bar{\\Xi}^0)=(1.20\\pm 0.12\\pm 0.21)\\times 10^{-3}$, where the first errors are statistical and the second ones are systematic.

2008-01-01

8

The interaction of fast alpha particles with pellet ablation clouds  

International Nuclear Information System (INIS)

The energy spectra of energetic confined alpha particles are being measured using the pellet charge exchange method [R. K. Fisher, J. S. Leffler, A. M. Howald, and P. B. Parks, Fusion Technol. 13, 536 (1988)]. The technique uses the dense ablation cloud surrounding an injected impurity pellet to neutralize a fraction of the incident alpha particles, allowing them to escape from the plasma where their energy spectrum can be measured using a neutral particle analyzer. The signal calculations given in the above-mentioned reference disregarded the effects of the alpha particles' helical Larmor orbits, which causes the alphas to make multiple passes through the cloud. Other effects such as electron ionization by plasma and ablation cloud electrons and the effect of the charge state composition of the cloud, were also neglected. This report considers these issues, ...

9

Electrical properties of airborne nanoparticles produced by a commercial spark-discharge generator  

International Nuclear Information System (INIS)

A nanoparticle generator based on the principle of electrical discharge (PALAS GFG-1000) was used to produce nanoparticles of different chemical natures. The fractions of electrically neutral particles were then measured by means of a Spectrometre de Mobilite Electrique Circulaire (SMEC, i.e. radial-flow mobility analyzer) for different operating conditions. The experimental results were compared with the theoretical values calculated from the Fuchs extended charge equilibrium model for spherical particles and agglomerates. For the smallest particles (below 20 nm), the deviations observed remain below 10%, and tend towards 20% for larger particles (over 35 nm).

2010-08-01

10

Complex plasma: dusts in plasma  

International Nuclear Information System (INIS)

Dust particles in a plasma are charged negatively and are subject to various types of forces, including a drag force by plasma particles and a force due to the collective nature of a plasma. Dust particles are found in a sheath in laboratories balanced by the gravitational force and the electric force, while dust particles in space are ubiquitous, including planetary magnetospheres and interstellar space. Because of the novel nature of a complex system involving plasma particles and dust particles in a collective way, the dusty plasma is often called a complex plasma. The complex plasma is characterized by two distinctly different scales in time and in space. The plasma with electrons, ions and neutrals is characterized by the collective motion with a fast time scale and a short wavelength, while the dust particles move ...

2007-04-21

11

The Development of a Neutral Particle Detector for Observations of the Thermosphere  

Science.gov (United States)

One of the least understood regions of the upper atmosphere is the thermosphere, principally due to the difficulty of making observations. The neutral atmosphere is known to be highly variable, and its composition and density varies by several orders of magnitude due to solar activity, diurnal cycles, latitude, geomagnetic activity, and gravity waves. In the past, most in-situ measurements of the neutral atmosphere have utilized detectors that are dependent on arrival angle and energy accommodation of incoming species, so that information related to nascent velocity distribution and reactive species abundances is often masked. This paper will review design concepts and laboratory tests related to the development of a novel open-ionizer, neutral particle detector for space environment measurements which can overcome these limitations. The sensor features a very large field-of-view suitable for ...

2006-12-01

12

Particle simulation of edge pedestal formation and plasma rotation dynamics  

International Nuclear Information System (INIS)

Gyrokinetic particle simulation of edge pedestal formation and plasma rotation dynamics will be presented, and compared with experimental observations. Realistic tokamak edge geometry is used which include separatrix/X-point and material wall from EFIT g-eqdsk data. In order to handle adequately the spatially inhomogeneous electric potential in the scrape-off region, the full-f electron technique is used, in addition to the full-f ions. Monte Carlo neutral particles with wall recycling coefficient will be included self-consistently with the plasma kinetics. Ion-ion Coulomb collisions will be particle, momentum and energy conserving. Energy source for the pedestal and scrape-off plasmas is the heat flow from the core plasma, and the particle source is the ionization of the neutral atoms which are either wall recycled and/or gas puffed. The simulation will be ...

2007-03-26

13

The Hard X-ray Spectral Evolution in XRBs, AGNs and ULXs  

CERN Document Server

We explore the relationship between the hard X-ray photon index $\\Gamma$ and the Eddington ratio (\\xi=L_{X}(0.5-25 keV)/L_{Edd}) in six XRBs. We find that different XRBs follow different anti-correlations between $\\Gamma$ and $\\xi$ when $\\xi$ is less than a critical value, while they follow the same positive correlation when $\\xi$ is larger than the critical value. This anti-correlation and positive correlation are also found in LLAGNs and QSOs respectively, and the anti-correlation and positive correlation of different XRBs roughly converge to the same point ($\\log \\xi=-2.1, \\Gamma=1.5$), which may correspond to the accretion mode transition, since that the anti-correlation and positive correlation are consistent with the prediction of ADAFs and standard disk/corona system respectively. The traditional low/hard state are divided into two parts by the cross point $\\log ...

2008-01-01

14

Production of MSSM Higgs bosons in photon-photon collisions  

International Nuclear Information System (INIS)

The heavy neutral Higgs bosons H, A in the minimal supersymmetric extension of the standard model can be produced as single resonances at high-energy #gamma##gamma# colliders. We have studied the prospects of the search for these particles in bb and neutralino-pair final states. The Higgs bosons can be found with masses up to 70-80% of the initial e"#+-#e"- collider energy for medium values of tg#beta#, i.e. in areas of the supersymmetric parameter space not accessible at other colliders. (orig.)

15

Production of MSSM Higgs bosons at future #gamma##gamma# colliders  

International Nuclear Information System (INIS)

Future #gamma##gamma# colliders allow the production of the heavy neutral MSSM Higgs bosons H and A as single resonances. The prospects of finding these particles in the bb-bar and the neutralino-pair final states have been analyzed. The H, A bosons can be discovered for medium values of tan #beta# with masses up to 70-80% of the initial e"#+-#e"- c.m. energy. This production mode thus covers parts of the supersymmetric parameter space that are not accessible at other colliders.

2001-07-09

16

Core localized toroidal Alfven eigenmodes destabilized by energetic ions in the CHS heliotron/torsatron  

Energy Technology Data Exchange (ETDEWEB)

Toroidal Alfven eigenmodes (TAE) destabilized by the pressure gradient of energetic alpha particles may expel the alpha particles before thermalization. TAE is important for tokamaks, and for helical systems (stellarators) as well. In CHS (compact helical system) TAE localized in the plasma core are destabilized when the plasma current is induced by co-injection of neutral beams. The observed TAE exhibits a ballooning nature. The internal structure of TAE was measured with a soft X-ray detector. The soft X-ray fluctuations level for TAE is too low to obtain the radial profiles of fluctuation intensities. (Tanaka, M.)

1999-09-01

18

Neutral-meson oscillations with torsion  

CERN Document Server

We propose a simple mechanism that may explain the observed particle-antiparticle asymmetry in the Universe. In the Einstein-Cartan-Sciama-Kibble theory of gravity, the intrinsic spin of matter generates spacetime torsion. Classical Dirac fields in the presence of torsion obey the nonlinear Hehl-Datta equation which is asymmetric under a charge-conjugation transformation. Accordingly, at extremely high densities that existed in the very early Universe, fermions have higher effective masses than antifermions. As a result, a meson composed of a light quark and a heavy antiquark has a lower effective mass than its antiparticle. Neutral-meson oscillations in thermal equilibrium therefore favor the production of light quarks and heavy antiquarks, which may be related to baryogenesis.

2011-01-01

19

On the properties of plasma crystals  

Energy Technology Data Exchange (ETDEWEB)

When a plasma becomes contaminated by foreign particles, generically referred to as dust, the result is called a dusty plasma. At the present time there is a great deal of interest in dusty plasmas because of their roles in terrestrial and extra-terrestrial processes - semiconductor processing, high temperature fusion experiments, stellar formation and the rings of Saturn. This thesis is concerned with the role of dust in processing type plasmas. In the following experiments, artificial dust is introduced into a parallel electrode plasma chamber. Ions and electrons in the plasma charge the dust particles and they become suspended in the plasma due to the balancing of electric and gravitational forces. By illuminating the suspended dust with laser light and using an extremely high speed camera fitted with a macro lens to look at the scattered light, the dust particles are observed directly. Specially written computer ...

1999-07-01

20

Laser Raman scattering measurements of differential molecular diffusion in turbulent nonpremixed jet flames of H{sub 2}/CO{sub 2} fuel  

Science.gov (United States)

This paper explores effects of differential diffusion in nonpremixed turbulent jet flames. Pulsed Raman scattering spectroscopy is used to measure temperature and species concentrations in chemically reacting jets of H{sub 2}/CO{sub 2} into air, over a range of jet Reynolds numbers from 1,000 to 30,000 based on cold jet fluid properties. Results show significant effects of differential diffusion at all jet Reynolds numbers considered. Differential diffusion between H{sub 2} and C0{sub 2} produces differences between the hydrogen element mixture fraction ({xi}{sub H}) and the carbon element mixture fraction ({xi}{sub c}). The greatest effects occur on the rich side of stoichiometric, where {xi}{sub H} is observed to be smaller than {xi}{sub C} at all Reynolds numbers. Differential diffusion between H{sub 2} and H{sub 2}O creates a net flux of hydrogen element toward the stoichiometric contour and causes ...

1994-01-01

21

The search for decaying Dark Matter  

CERN Document Server

We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry of the Universe. In super-WIMP models, ...

2009-01-01

22

Thermal conductivity of leaf compost used in biofilters: An experimental and theoretical investigation  

International Nuclear Information System (INIS)

Thermal conductivity is an important property that governs the behaviour of leaf compost biofilters used in treating gaseous pollutants. Measurements were carried out for the thermal conductivity (K) of 44 samples of leaf compost, covering wide ranges of the volume fractions of water (#xi#_w), solids (#xi#_s) and air (#xi#_a), at 20 deg. C using an unsteady state thermal probe. The results indicated that the compost thermal conductivity increased with an increase in #xi#_w, with a decrease in #xi#_a, and with an increase in the degree of saturation (defined as the volumetric fraction of water in the total void space). The predictions from the Woodside-Messmer quadratic parallel (QP) model for the thermal conductivity of leaf compost were higher than the experimental values. A simple linear relationship was developed between the thermal conductivity and the degree of saturation, ...

2005-07-01

23

Some remarks on the coherent-state variational approach to nonlinear boson models  

CERN Document Server

The mean-field pictures based on the standard time-dependent variational approach have widely been used in the study of nonlinear many-boson systems such as the Bose-Hubbard model. The mean-field schemes relevant to Gutzwiller-like trial states $|F>$, number-preserving states $|\\xi >$ and Glauber-like trial states $|Z>$ are compared to evidence the specific properties of such schemes. After deriving the Hamiltonian picture relevant to $|Z>$ from that based on $|F>$, the latter is shown to exhibit a Poisson algebra equipped with a Weyl-Heisenberg subalgebra which preludes to the $|Z>$-based picture. Then states $|Z>$ are shown to be a superposition of $\\cal N$-boson states $|\\xi>$ and the similarities/differences of the $|Z>$-based and $|\\xi>$-based pictures are discussed. Finally, after proving that the simple, symmetric state $|\\xi>$ indeed corresponds to a SU(M) ...

2008-01-01

24

PRA and Risk Informed Analysis  

Science.gov (United States)

The Boiler and Pressure Vessel Code (BPVC) of the American Society of Mechanical Engineers (ASME) has introduced a risk based approach into Section XI that covers Rules for Inservice Inspection of Nuclear Power Plant Components. The risk based approach requires application of the probabilistic risk assessments (PRA). Because no industry consensus standard existed for PRAs, ASME has developed a standard to evaluate the quality level of an available PRA needed to support a given risk based application. The paper describes the PRA standard, Section XI application of PRAs, and plans for broader applications of PRAs to other ASME nuclear codes and standards. The paper addresses several specific topics of interest to Section XI. Important consideration are special methods (surrogate components) used to overcome the lack of PRA treatments of passive components in PRAs. The approach allows calculations of conditional core ...

2006-01-01

25

PRA and Risk Informed Analysis  

Energy Technology Data Exchange (ETDEWEB)

The Boiler and Pressure Vessel Code (BPVC) of the American Society of Mechanical Engineers (ASME) has introduced a risk based approach into Section XI that covers Rules for Inservice Inspection of Nuclear Power Plant Components. The risk based approach requires application of the probabilistic risk assessments (PRA). Because no industry consensus standard existed for PRAs, ASME has developed a standard to evaluate the quality level of an available PRA needed to support a given risk based application. The paper describes the PRA standard, Section XI application of PRAs, and plans for broader applications of PRAs to other ASME nuclear codes and standards. The paper addresses several specific topics of interest to Section XI. Important consideration are special methods (surrogate components) used to overcome the lack of PRA treatments of passive components in PRAs. The approach allows calculations of conditional core damage ...

2006-01-01

26

PRA and Risk Informed Analysis  

International Nuclear Information System (INIS)

The Boiler and Pressure Vessel Code (BPVC) of the American Society of Mechanical Engineers (ASME) has introduced a risk based approach into Section XI that covers Rules for Inservice Inspection of Nuclear Power Plant Components. The risk based approach requires application of the probabilistic risk assessments (PRA). Because no industry consensus standard existed for PRAs, ASME has developed a standard to evaluate the quality level of an available PRA needed to support a given risk based application. The paper describes the PRA standard, Section XI application of PRAs, and plans for broader applications of PRAs to other ASME nuclear codes and standards. The paper addresses several specific topics of interest to Section XI. Important consideration are special methods (surrogate components) used to overcome the lack of PRA treatments of passive components in PRAs. The approach allows calculations of conditional core damage ...

27

Production of negative ions by electron impact. Final report 1 May 81-31 Oct 82  

Science.gov (United States)

Proposed future space-based beam weapons systems will most probably require an intense neutral particle beam for effective operation across geomagnetic field lines. Such neutral beams can most efficiently be obtained by stripping excess electrons from negative ion beams. The objective of this work is to study the process of dissociative attachment of electrons. Specifically, to measure the cross sections for polar dissociation and dissociative attachment for production of H(-). It is suspected that these dissociative attachment cross sections for the production of H(-) from alkali hydrides are large. The insight gained from this study will be extremely helpful in the fabrication of high current density H(-) beam sources for use in the production of intense neutral hydrogen beams. A selection of alkali hydride molecules will be investigated in order to determine the largest cross sections for the ...

1982-10-01

28

Contribution to the study of sputtering and damage of uranium dioxide by fast heavy ions; Contribution a l'etude de la pulverisation et de l'endommagement du dioxyde d'uranium par les ions lourds rapides  

Energy Technology Data Exchange (ETDEWEB)

Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the ...

2001-03-01

29

Risk-based inspection in ASME Section XI  

International Nuclear Information System (INIS)

By 1970 the first edition of the ASME Code Section XI, Inservice Inspection of Nuclear Reactor Coolant Systems was published. From its inception, the Section XI inservice inspection scope was based on a fundamental risk-based selection process. In other words the inservice inspection scope included components where the consequences of a pressure boundary failure were high. Once the consequence significant system boundaries were established, inspections would then be performed at locations believed to be most susceptible service induced failure. Current Section XI requirements require that inspection locations be selected on the basis of peak stress and fatigue usage values contained in the Design Reports. These original stress calculations were designed to qualify a design and assure that the plant would provide reliable service throughout its design life. For the most part, the fatigue usage values in these reports do not ...

1996-07-21

30

To the problem of the Cherenkov radiation of tachyons  

International Nuclear Information System (INIS)

It is shown that the Cherenkov radiation of tachyons (CRT) in general case cannot possess axial symmetry with respect to velocity v. This implies that tachyons must be vector particles. Electric dipole is used as a vector characterising the tachyon. Formulas describing the CRT spectrum are derived taking into account the asymmetry for charged tachyon and neutral tachyon dipole with arbitrary orientation with respect to v. It is shown that both types of CRT possess the same integral characteristics. A new integral of motion specific for tachyons is found. Negative results of all attempts to detect the CRT are explained.

31

Production of MSSM Higgs bosons in photon-photon collisions  

Energy Technology Data Exchange (ETDEWEB)

The heavy neutral Higgs bosons H, A in the minimal supersymmetric extension of the standard model can be produced as single resonances at high-energy {gamma}{gamma} colliders. We have studied the prospects of the search for these particles in bb and neutralino-pair final states. The Higgs bosons can be found with masses up to 70-80% of the initial e{sup {+-}}e{sup -} collider energy for medium values of tg{beta}, i.e. in areas of the supersymmetric parameter space not accessible at other colliders. (orig.)

2000-12-01

32

Expansion Rate Measurements at Moderate Pressure of Nonneutral Electron Plasmas in the Electron Diffusion Gauge (EDG) Experiment  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the expansion rate of pure-electron plasmas have been performed on the Electron Diffusion Gauge (EDG) device at background helium gas pressures in the 5 x 10(superscript -8) Torr to 1 x 10(superscript -5) Torr range, where plasma expansion due to electron-neutral collisions dominates over plasma expansion due to trap asymmetries. It is found that the expansion rate, defined as the time rate of change of the particles' mean-square radius, scales approximately linearly with pressure and inversely as the square of the magnetic field strength in this regime, in agreement with classical predictions.

2001-05-18

33

The influence of chemically active gas on the light emission of metallic targets bombarded by positive ions  

International Nuclear Information System (INIS)

The introduction of oxygen in the vicinity of a metallic target surface, bombarded with positive argon ions of twenty kiloelectron-volts, increases the number of sputtered atoms in the excited state. This phenomenon of exaltation, very sensitive in the case of nickel and aluminium, is much less marked in the case of molybdenum. Moreover, the emission of excited particles coming from the beam's ions is not modified. A quantum-mechanical model of a kinetic emission process, which permits the interpretation of the clean metallic target's emission phenomena, seems insufficient to explain all of the results obtained in the presence of oxygen. In this last case one can therfore use a thermodynamic model in which excited metallic particles can be formed directly by chemical surface reactions of neutralization or reduction. (orig.).

34

Role of natural organic matter (NOM), colloidal particles, and solution chemistry on ultrafiltration performance  

British Library Electronic Table of Contents (United Kingdom)

Mechanistic studies on a charged ultrafiltration (UF) membrane fouled with natural organic matter (NOM) and colloidal particles are systematically investigated to understand the relative role of each NOM fraction and the presence of colloidal particulate to membrane fouling. Humic acid (HA), dextran, and kaolin were employed as surrogate model foulants representing the organic hydrophobic acid NOM, hydrophilic neutral NOM, and inorganic colloidal materials, respectively. The results obtained showed that the organic NOM of hydrophilic surrogate (dextran) plays a primary role in promoting membrane fouling, followed by hydrophobic acids and inorganic kaolin, but to a lesser extent than organic NOM compounds. Significant differences in the extent of fouling between dextran and HA have been obs...

2011-01-01

35

Study of Pd-Sn/Al{sub 2}O{sub 3} catalysts prepared by an oxide colloidal route; Etude de catalyseurs Pd-Sn/Al{sub 2}O{sub 3} prepares par voie colloidale oxyde  

Energy Technology Data Exchange (ETDEWEB)

The oxide colloidal route, developed in the laboratory for mono-metallic catalysts, consists in preparing a metallic oxide hydro-sol which leads to the supported catalyst after deposition onto a support and an activation stage. In this work, this method has been adapted to the preparation of alumina supported bimetallic Pd-Sn catalysts to determine its interest for the control of the properties of the bimetallic phase (size, composition and structure). In the preliminary study concerning tin oxide sols, SnO{sub 2} (size=2,3 nm) and Sn{sub 6}O{sub 4}(OH){sub 4} (size = 25 nm) nano-particles were synthesized by neutralization respectively for tin(IV) and tin(H). The control through the pH of the aggregation of the PdO and SnO{sub 2} particles revealed that increasing oxide solubility promotes integral re-dispersion of the oxide particles. To synthesize oxide bimetallic sols, three strategies were defined. ...

2001-09-01

36

Energy-resolved electron particle and energy fluxes in positive column plasmas  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with electron flux densities and electron energy flux densities in positive column discharges. Recent kinetic calculations by Uhrlandt and Winkler have revealed the interesting physical phenomenon of radially inward directed energy flux densities in positive column plasmas. We have used a self-consistent positive column model, based on an accurate and highly detailed Monte Carlo code, to study this effect in more depth. The results of this study show a rather complex physical picture of electron particle and energy flux densities. Electrons with low energies usually exhibit radially outward directed particle and energy flux densities. At energies above the threshold for electronic excitation particle and energy flux densities are usually inward directed. Only close to the wall, at total energies above the wall potential energy, do these flux densities point towards the wall. The thickness of this ...

1999-11-07

37

Plasma neutralization models for intense ion beam transport in plasma  

Energy Technology Data Exchange (ETDEWEB)

Plasma neutralization of an intense ion pulse is of interest for many applications, including plasma lenses, heavy ion fusion, cosmic ray propagation, etc. An analytical electron fluid model has been developed based on the assumption of long charge bunches (l{sub b} >> r{sub b}). Theoretical predictions are compared with the results of calculations utilizing a particle-in-cell (PIC) code. The cold electron fluid results agree well with the PIC simulations for ion beam propagation through a background plasma. The analytical predictions for the degree of ion beam charge and current neutralization also agree well with the results of the numerical simulations. The model predicts very good charge neutralization (>99%) during quasi-steady-state propagation, provided the beam pulse duration {tau}{sub b} is much longer than the electron plasma period 2{pi}/{omega}{sub p}, where {omega}{sub ...

2003-05-01

38

Phenomenological Theory of the Kink Instability in a Slender Plasma Column  

Energy Technology Data Exchange (ETDEWEB)

When one deals with a plasma column whose radius a is much smaller than its length L, one can think of it as of a thin filament whose kink instability can be adequately described simply by a 2D displacement vector, {xi}{sub x} = {xi}{sub s}(z,t); {xi}{sub y} = {xi}{sub y}(z,t). Details of the internal structure of the column such as the current, density, and axial flow velocity distribution would be lumped into some phenomenological parameters. This approach is particularly efficient in the problems with non-ideal (sheath) boundary conditions (BC) at the end electrodes, with the finite plasma resistivity, and with a substantial axial flow. With the sheath BC imposed at one of the end-plates, we find instability in the domain well below the classical Kruskal-Shafranov limit. The presence of an axial flow causes the onset of rotation of the kink and strong axial ...

2005-11-18

39

A simplified proof of the relation between scaling exponents in first-passage percolation  

CERN Document Server

In a recent breakthrough work, Chatterjee proved a long standing conjecture that relates the transversal exponent \\xi and the fluctuation exponent \\chi in first-passage percolation on Z^d. The purpose of this paper is to introduce a new and intuitive idea that replaces Chatterjee's main argument and gives an alternative proof of this relation. Specifically, we show that under the assumption that exponents (as defined by Chatterjee) exist, one has the relation \\chi \\leq 2\\xi -1. One advantage of our argument is that it does not require a `nearly Gamma' assumption on the edge-weight distribution.

2011-01-01

40

Higgs production in association with squark pairs in the Minimal Supersymmetric Standard Model at future hadron colliders  

CERN Document Server

We study neutral and charged Higgs boson production in association with stop and sbottom squarks at the Large Hadron Collider, within the supergravity inspired minimal supersymmetric standard model We study neutral and charged Higgs boson production in association with stop and sbottom squarks at the Large Hadron Collider, within the Supergravity inspired Minimal Supersymmetric Standard Model. The phenomenological relevance of such reactions is twofold. Firstly, they constitute a novel production mechanism of Higgs particles, either through a decay of a heavier (anti)squark into a lighter one or via a Higgs bremsstrahlung process. Secondly, their production rates are extremely sensitive to the values assumed by the five input parameters of the model, this possibly allowing one to put stringent constraints on the latter. After an exhaustive scan of the parameter space, we find that the majority of such processes could be ...

1999-01-01

41

Near-real time infrared observations of acidic sulfates in /open quotes/clean/close quotes/ air at Mauna Loa, Hawaii  

Energy Technology Data Exchange (ETDEWEB)

Sulfuric acid and its partially or completely neutralized salts with ammonia are believed to result from the oxidation of sulfur dioxide in cloud water and in other heterogeneous media present in the atmosphere. Due to the natural abundance of ammonia and the ubiquitous presence of sulfur in the atmosphere, (NH/sub 4/)/sub 2/SO/sub 4/ is commonly the dominant chemical species in the ambient aerosol. The amounts of ammonium sulfates are expected to be very low in areas far removed from anthropogenic emissions of sulfur dioxide. The chemical composition of submicrometer aerosol particles was determined at the Mauna Loa Observatory (MLO) on Mauna Loa in Hawaii during an eight-day period in August 1986. The MLO site was selected for this measurement because it is the only ground-based aerosol observatory in the remote Pacific Ocean that allows extended sampling of aerosols in the free troposphere. Measurements were made using an attenuated total ...

1988-01-01

42

Time-of-flight measurements of light molecular ions scattered at grazing incidence from a Ni(111) surface  

Energy Technology Data Exchange (ETDEWEB)

A time-of-flight mass spectrometer has been constructed to measure the energy spectra of particles scattered by 10/sup 0/ with primary energies between 200 eV and 15 keV. The energy resolution ..delta..E/E of the system is between 0.1 and 0.4%. Energy spectra of scattered molecules and their dissociation products are shown for 570 eV H/sub 2//sup +/ and 4430 eV N/sub 2//sup +/ as projectiles. Electron capture into unbound states of the neutral molecule, with perhaps some contribution from mutual scattering within the molecule, appears to explain the observed dissociation product energy spectra peak widths.

1984-03-01

43

Time-of-flight measurements of light molecular ions scattered at grazing incidence from a Ni(111) surface  

International Nuclear Information System (INIS)

A time-of-flight mass spectrometer has been constructed to measure the energy spectra of particles scattered by 10"0 with primary energies between 200 eV and 15 keV. The energy resolution #DELTA#E/E of the system is between 0.1 and 0.4%. Energy spectra of scattered molecules and their dissociation products are shown for 570 eV H_2"+ and 4430 eV N_2"+ as projectiles. Electron capture into unbound states of the neutral molecule, with perhaps some contribution from mutual scattering within the molecule, appears to explain the observed dissociation product energy spectra peak widths. (orig.).

44

Ion temperature anisotropy in high power helium neutral beam fuelling experiments in JET  

Energy Technology Data Exchange (ETDEWEB)

During helium beam fuelling experiments in JET, distinctive anisotropic features have been observed in the velocity distribution function describing both fast and thermal alpha particle populations. During the initial fuelling phase the central helium ion temperature observed perpendicular to the magnetic field is higher than the central electron temperature, while the central helium ion temperature observed parallel to the magnetic field is lower than or equal to the central electron temperature. In order to verify temperature measurements of both perpendicular and parallel lines of sight, other independent methods of deducing the ion temperature are investigated: deuterium ion temperature, deuterium density, comparison with neutron rates and profiles (influence of a possible metastable population of helium). 6 refs., 7 figs.

1994-07-01

45

Intermediates of radiolytic transformations of 6-aminophenalenone in ethanol  

International Nuclear Information System (INIS)

Pulsed radiolysis method is used to study transformations intermediates of 6-aminophenalenone in ethanol. In alkaline medium the main product is radical-anion of 6-aminophenalenone, which optical absorption spectrum contains two bands with maxima at 355 and 400 nm. The particle precursors are e_s, CH_3CHOH and CH_3CHO"- radicals. In neutral and acid medium radical-anions are protonated in reactions with alcohol and hydrogen ions. The resulting H-adduct of 6-aminophenalenone has optical absorption maxima at 350 and 390 nm. Availability of two maxima is related to two various product structures. Molar extinction coefficients of radical-anions and H-adducts of 6-aminophenalenone and rate constants of reactions with their participation are estimated.

1992-01-01

46

Intermediate products of radiolytic conversions of 6-aminophenalenone in ethanol  

International Nuclear Information System (INIS)

Intermediate products of the conversions of 6-aminophenalenone in ethanol were investigated by pulse radiolysis. In alkaline medium the main product is the 6-aminophenalenone radical cation, the optical absorption spectrum of which contains two bands with maxima at 355 and 400 nm. The precursors of this particle are e_s, CH_3CHOH and CH_3CHO"- radicals. In neutral and acid medium, radical cations are protonated in reactions with alcohol and hydrogen ions. The H-adduct of 6-aminophenalenone that arises has optical absorption maxima at 350 and 390 nm. The presence of two maxima is due to two different structures of the product. The molar extinction coefficients of the radical anions and H-adducts of 6-aminophenalenone and the rate constants of the reactions involving them were estimated. 6 refs., 4 figs., 2 tabs.

1992-01-01

47

Dendrosomes as novel gene porters-III  

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND: It was previously reported that dendrosomes, i.e. neutral, biodegradable, covalent or self-assembled, hyperbranched, spheroidal nano-particles with a size ranging from 15 to 100 nm, provide a convenient and efficient means of gene delivery into various kinds of cells such as human hepatoma and kidney cells as well as animal models.RESULTS: New studies via circular dichroism show that hydrophilic and amphipathic dendrosomes either do not affect the DNA structure or moderately transform it from B- to A-conformation. Gene delivery into human liver, kidney, and endothelial cells as well as other animal cells like Bowes, U-937, Raw, CCRF-CEM, MOLT-4, K562, Huh-7 and VERO reveal that the genes are efficiently expressed and in comparison with other gene porters like Lipofectin or bact...

2008-01-01

48

Collisionless driven reconnection in an open system  

Energy Technology Data Exchange (ETDEWEB)

Particle simulation studies of collisionless driven reconnection in an open system are presented. Collisionless reconnection evolves in two steps in accordance with the formation of two current layers, i.e., an ion current layer in the early ion phase and an electron current layer in the late electron phase. After the electron current layer is formed inside the ion current layer, the system relaxes gradually to a steady state when convergent plasma flow is driven by an external electric field with a narrow input window. On the other hand, when the convergent plasma flow is driven from the wide input window, magnetic reconnection takes place in an intermittent manner, due to the frequent formation of magnetic islands in the vicinity of neutral sheet. (author)

2000-06-01

49

Quantitative descriptions of nonlinear gravitational galaxy clustering  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate nonlinear gravitational galaxy clustering, three different quantitative analyses were carried out: two-point correlation functions, {xi}(r); fractal dimensions, D{sub q}; and f(N) statistics. The relation between the exponent {gamma} of the correlation function ({xi}(r) {proportional to} r{sup -{gamma}}) and the fractal dimensions, D{sub q}, was derived with the help of the probability distribution function, f(N), for finding N galaxies within a volume V. The methods were applied to analyze the results of N-body simulations with power law initial density fluctuations ( {delta}{sub k} {sup 2} {proportional to} k{sup n}, n = 1, 0, -1 and -2). These analyses show that the exponent, {gamma}, of the power law {xi}(r) is approximately 2 in the nonlinear regime for models with n = 1 and 0. For models with n = -1 and -2, the correlation functions comprise two parts of the intermediate and small scales in the ...

1990-01-01

50

Particle Swarm Optimization  

CERN Document Server

Particle Swarm Optimization

2006-01-01

51

The BESS model revisited as a Higgsless Linear Moose @ the LHC  

CERN Document Server

We study the phenomenological consequences of a four site Higgsless model based on the SU(2)_L x SU(2)_1 x SU(2)_2 x U(1)_Y gauge symmetry, which predicts two neutral and four charged extra gauge bosons, Z_{1,2} and W_{1,2}. The model represents an extension of the minimal three site version (or BESS model), largely investigated in the literature, which includes three heavy vector bosons. We compute the properties of the new particles, and derive indirect and direct limits on their masses and couplings from LEP and Tevatron data and from the perturbative unitarity requirements. In contrast to other Higgsless models characterized by fermiophobic extra gauge bosons, here sizeable fermion-boson couplings are allowed by the electroweak precision data. The prospects of detecting the new predicted particles in the favoured Drell-Yan channel at the LHC are thus investigated. The outcome is that all six extra gauge bosons could be ...

2010-01-01

52

Selecting soil amendment materials for removal of phosphorus  

Energy Technology Data Exchange (ETDEWEB)

Phosphorus sorption capacities of several different materials including Merribrook soil (a loamy sand) and some industrial solid wastes (red mud neutralized with gypsum, fly ash, bottom ash and black oxide) were determined in sorption isotherms by Langmuir and Freundlich equations. The materials were characterized by bulk density, particle density, total porosity and particle size distributions. Red mud gypsum possessed the best sorption capacity based on the Langmuir maxima. Alkaline fly ash and Merribrook soil had lower sorption maxima compared to the red mud gypsum. Bottom ash and acidic fly ash had very low sorption capacity at low concentrations. Merribrook soil had the highest hydraulic conductivity. The results suggested that alkaline fly ash may be a promising amendment for coarse sand bed to enhance phosphorus removal. Merribrook soil appears to be suitable for on-site wastewater treatment.

1994-12-31

53

Neutrino emission in neutron matter from magnetic moment interactions  

CERN Document Server

Neutrino emission drives neutron star cooling for the first several hundreds of years after its birth. Given the low energy ($\\sim$ keV) nature of this process, one expects very few nonstandard particle physics contributions which could affect this rate. Requiring that any new physics contributions involve light degrees of freedom, one of the likely candidates which can affect the cooling process would be a nonzero magnetic moment for the neutrino. To illustrate, we compute the emission rate for neutrino pair bremsstrahlung in neutron-neutron scattering through photon-neutrino magnetic moment coupling. We also present analogous differential rates for neutrino scattering off nucleons and electrons that determine neutrino opacities in supernovae. Employing current upper bounds from collider experiments on the tau magnetic moment, we find that the neutrino emission rate can exceed the rate through neutral current electroweak interaction by a ...

2004-01-01

54

Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Solenoidal Magnetic Field I: Weak Magnetic Field Limit  

Energy Technology Data Exchange (ETDEWEB)

Propagation of an intense charged particle beam pulse through a background plasma is a common problem in astrophysics and plasma applications. The plasma can effectively neutralize the charge and current of the beam pulse, and thus provides a convenient medium for beam transport. The application of a small solenoidal magnetic field can drastically change the self-magnetic and self- electric fields of the beam pulse, thus allowing effective control of the beam transport through the background plasma. An analytic model is developed to describe the self-magnetic field of a finite- length ion beam pulse propagating in a cold background plasma in a solenoidal magnetic field. The analytic studies show that the solenoidal magnetic field starts to infuence the self-electric and self-magnetic fields when ?ce > ?pe?b, where ?ce = e?/mec is the electron gyrofrequency, ?pe is the electron plasma frequency, and ?b = Vb/c is the ion beam velocity relative ...

2008-10-10

55

Performance estimates of photoneutralized negative-ion beams  

Energy Technology Data Exchange (ETDEWEB)

Recent studies have provided data that make it possible to estimate the efficiency and cost of future beamlines using a chemical oxygen-iodine laser as a neutralizer. These studies indicate that a 400-keV neutral deuterium beam of more than 20 A will operate at an efficiency >60%, with the capital cost of the neutralizer at less than $2/W of neutral beam output. Beamlines of lower current and less energy will operate at poorer efficiencies and higher neutralizer costs per watt of neutral beam. These are estimates. As they are very sensitive to changes in the assumptions from which they were derived, they must be used with some caution. Additional studies are expected to provide more reliable estimates.

1984-11-01

56

Quantification of the influence of the choice of the algorithm and planning system on the calculation of a treatment plan  

International Nuclear Information System (INIS)

In this work an analysis of the influence of the choice of the algorithm or planning system, on the calculus of the same treatment plan is introduced. For this purpose specific software has been developed for comparing plans of a series of IMRT cases of prostate and head and neck cancer calculated using the convolution, superposition and fast superposition algorithms implemented in the XiO 4.40 planning system (CMS). It has also been used for the comparison of the same treatment plan for lung pathology calculated in XiO with the mentioned algorithms, and calculated in the Plan 4.1 planning system (Brainlab) using its pencil beam algorithm. Differences in dose among the treatment plans have been quantified using a set of metrics. The recommendation for the dosimetrist of a careful choice of the algorithm has been numerically confirmed. (Author).

57

Interinstitutional Variations in Planning for Stereotactic Body Radiation Therapy for Lung Cancer  

British Library Electronic Table of Contents (United Kingdom)

Purpose: The aim of this study was to assess interinstitutional variations in planning for stereotactic body radiation therapy (SBRT) for lung cancer before the start of the Japan Clinical Oncology Group (JCOG) 0403 trial.Methods and Materials: Eleven institutions created virtual plans for four cases of solitary lung cancer. The created plans should satisfy the target definitions and the dose constraints for the JCOG 0403 protocol.Results: FOCUS/XiO (CMS) was used in six institutions, Eclipse (Varian) in 3, Cadplan (Varian) in one, and Pinnacle3 (Philips/ADAC) in one. Dose calculation algorithms of Clarkson with effective path length correction and superposition were used in FOCUS/XiO; pencil beam convolution with Batho power law correction was used in Eclipse and Cadplan; and collapsed co...

2007-01-01

58

Phenomenological analysis of heavy hadron lifetimes  

International Nuclear Information System (INIS)

A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find that bottom-baryon lifetimes follow the pattern #tau#(#OMEGA#_b)#approx =##tau#(#XI#_b"-)>#tau#(#LAMBDA#_b)#approx =##tau#(#XI#_b"0). However, neither the lifetime ratio #tau#(#LAMBDA#_b)/#tau#(B_d) nor the absolute decay rates of the #LAMBDA#_b baryon and B mesons can be explained. One way of solving both difficulties is to allow the presence of linear 1/m_Q corrections by scaling the inclusive nonleptonic width with the fifth power of the hadron mass m_H__Q rather than the heavy quark mass m_Q. The hierarchy of bottom baryon lifetimes is dramatically modified to #tau#(#LAMBDA#_b)>#tau#(#XI#_b"-)>#tau#(#XI#_b"0)>#tau#(#OMEGA#_b): The longest-lived #OMEGA#_b among bottom ...

59

Fuel-related advances in science and technology. (XI) Commerce. (3) Changes in coal liquefaction projects and the future outlook  

Energy Technology Data Exchange (ETDEWEB)

Accounts are given of the history of coal liquefaction research and projects (indirect liquefaction, direct liquefaction, plus the recent state of Japanese developments and of process development), and of the significance of the petroleum age, the energy crisis and of coal liquefaction itself. (10 refs.) (In Japanese)

1982-01-01

60

Estimates for a class of oscillatory integrals and decay rates for wave-type equations  

CERN Document Server

In this paper we first establish global pointwise time-space estimates for a class of oscillatory integrals. Then, we use them to establish $L^p-L^q$ estimates for a class of higher order wave-type equations of the form $\\partial_{tt}u+P(D_{x})u=0$, where the symbol $P(\\xi)$ is a real non-degenerate elliptic polynomial of ${\\bf R}^n$.

2011-01-01

61

2006d.rms - NASA  

Science.gov (United States)

... $84JAN07X 133 147.654 ps 56 fs/s RMS_DEL: $95NOV21DX 607 144.552 ps 208 ...... $86MAR09XI 378 34.285 ps 77 fs/s RMS_DEL: $95MAR23XA 1628 34.270 ps 223 ...

63

Neutralization of negative ion beams by a gas dynamic laser  

Energy Technology Data Exchange (ETDEWEB)

The possibility of applying the near infrared gas dynamic lasers (GDL) for neutralization of negative ion beams is examined. A criterion of neutralization is suggested. The use of the criterion makes it possible to select an optically active medium for a negative ion neutralization. To demonstrate the method media containing hydrohalogens as imitating molecules are taken. ((orig.))

1994-11-01

64

Chemical Reactor Diagnostics  

International Science & Technology Center (ISTC)

Development of Methods and Apparatus for Processes Diagnostics in Plasma Reactors at the Neutralization of Chemical Herbiside and Pestiside

65

BNL Neutral Beam Development Group. Progress report, FY 1983 and final report  

Energy Technology Data Exchange (ETDEWEB)

The BNL Neutral Beam Development Group has been active in the program for the development of high energy, high power neutral beam systems since 1973. These injectors are based on the production, acceleration and neutralization of negative hydrogen or deuterium ions and are supposed to be used for plasma heating and current drive in the next generation of fusion devices. Over the span of 10 years the group has studied plasma-surface type of negative hydrogen ion sources, transport and acceleration of negative ion beams and neutralization of negative ions in gases and plasmas. As the required source parameters (current, pulse length, efficiency) were changing over this period of time, the group developed several types of sources, resulting finally in the design of a steady state device operating with an excellent gas efficiency and having the possibility of scaling-up to the size necessary for a high ...

1984-03-16

66

Validation of the 3D finite element transport theory code EVENT for shielding applications  

Energy Technology Data Exchange (ETDEWEB)

This paper is concerned with the validation of the 3D deterministic neutral-particle transport theory code EVENT for shielding applications. The code is based on the finite element-spherical harmonics (FE-P{sub N}) method which has been extensively developed over the last decade. A general multi-group, anisotropic scattering formalism enables the code to address realistic steady state and time dependent, multi-dimensional coupled neutron/gamma radiation transport problems involving high scattering and deep penetration alike. The powerful geometrical flexibility and competitive computational effort makes the code an attractive tool for shielding applications. In recognition of this, EVENT is currently in the process of being adopted by the UK nuclear industry. The theory behind EVENT is described and its numerical implementation is outlined. Numerical results obtained by the code are compared with predictions of the Monte Carlo code MCBEND and also with the results ...

2000-03-01

67

Negative ion source electrode  

Energy Technology Data Exchange (ETDEWEB)

The present invention concerns a negative ion source electrode which can be preferably used in a neutral particle injection device using negative ions for a thermonuclear reactor. Negative ion beams are deflected to the direction opposite to the deflecting direction by magnetic fields by using an electron suppression electrode having electrode holes with the position previously displaced before negative ion beams are accelerated to have a high energy by an accelerator thereby correcting the orbit of the negative ion beams easily. In addition, since the deflection correction electrode having the electrode holes is disposed, a proper voltage is applied to the deflection correction electrode to correct the orbit of the negative ion beams conveniently. Since the deflection correction electrode has a simple structure of a thin flat plate having electrode holes, the orbit of negative ion beams can be corrected efficiently by an extremely simple ...

1997-01-17

68

$r$-Parity Violating Anomaly Mediated Supersymmetry Breaking  

CERN Document Server

We propose a new scenario that solves the slepton negative mass squared problem of the minimal supersymmetric standard model with anomaly mediated supersymmetry breaking. The solution is achieved by including three trilinear R-parity violating operators in the superpotential. The soft supersymmetry breaking terms satisfy renormalisation group invariant relations in terms of supersymmetric couplings and the overall supersymmetry breaking mass scale. Flavour changing neutral currents are naturally highly suppressed. The model predicts tan beta=4.2 +/- 1.0. Excluding sleptons, the supersymmetric particle spectrum depends upon two remaining free parameters. In the case of the R-parity violating couplings at their quasi-fixed points at a supersymmetric GUT scale, the whole sparticle spectrum approximately depends upon only one free parameter. Imposing experimental limits leads to a constrained and distinctive phenomenology. The lightest CP-even ...

2000-01-01

69

Theory of mirror machines at high beta  

Science.gov (United States)

The kinetic and guiding center fluid theories of high-..beta.. plasma containment in mirror machines have been developed in a number of self-consistent models. The geometrical effects of magnetic field and ambipolar potential variation have been incorporated in a bounce-averaged Fokker-Planck code which shows that the square-well model somewhat overestimates the n tau and ..beta.. achievable in a mirror field. Simple analytic approximations to the resulting pressure profiles have been incorporated in three-dimensional fluid-equilibrium codes which show the effect of coil geometry on the maximum ..beta... Strongly curved vacuum fields allow higher ..beta.., but short plasmas in weakly curved fields tend to reverse the curvature locally before the mirror-mode limit is reached. Adiabaticity of particle orbits is described in terms of general formulas, applicable in high-..beta.. plasma equilibria, and is shown to break down close to the mirror-mode limit. Two ...

1976-08-06

70

Higgs, SUSY and the standard model at {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

In this report, I surveyed physics potential of the {gamma}{gamma} option of a linear e{sup +}e{sup -} collider with the following questions in mind: What new discovery can be expected at a {gamma}{gamma} collider in addition to what will be learned at its 'parent' e{sup +}e{sup -} linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e{sup -} beams, we find that a {gamma}{gamma} collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e{sup -}e{sup -} system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a {gamma}{gamma} collider. CP property of the scalar sector can be explored in detail by making use of ...

2001-10-11

71

Higgs, SUSY and the standard model at #gamma##gamma# colliders  

International Nuclear Information System (INIS)

In this report, I surveyed physics potential of the #gamma##gamma# option of a linear e"+e"- collider with the following questions in mind: What new discovery can be expected at a #gamma##gamma# collider in addition to what will be learned at its 'parent' e"+e"- linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e"- beams, we find that a #gamma##gamma# collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e"-e"- system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a #gamma##gamma# collider. CP property of the scalar sector can be explored in detail by making use of linear polarization of the colliding photons, decay ...

2001-10-11

72

Extension of improved particle and energy confinement regime in the core of LHD plasma  

International Nuclear Information System (INIS)

Recent two major topics of Large Helical Device (LHD) towards fusion relevant conditions, high-density operation and high-ion-temperature operation, are reported. Super dense core plasma was obtained by the combination of repetitive hydrogen ice pellet injection and high power neutral beam injection (NBI) heating. A very peaked density profile with the highest central density of 1.1x1021 m-3 was produced showing that the particle transport was suppressed very well in the plasma core. The spatial density varies as the position of magnetic axis (Rax), and the steepest profile is obtained at Rax=3.95 m. The highest central ion temperature of 5.6 keV was obtained in hydrogen plasma at electron density of 1.6 x 1019 m-3 by NBI, where a peaked ion-temperature profile with internal ion energy transport barrier was observed. The profile of electron temperature did not change much and was broad even when the ion temperature had a peaked profile. The ...

2009-06-01

73

Characterization of a time-of-flight mass spectrometer and its applications in the study of solid surfaces; Charakterisierung eines Flugzeitmassenspektrometers und seine Anwendungen in der Festkoerperoberflaechenuntersuchung  

Energy Technology Data Exchange (ETDEWEB)

The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best possible adaptation of the TOF mass spectrometer for the detection of highly ...

2006-12-21

74

Analysis of the Semileptonic Decay D0 --> anti-K0 pi- mu+ nu  

Energy Technology Data Exchange (ETDEWEB)

This thesis describes the analysis of the semileptonic decay D{sup 0} {yields} {bar K}{sup 0} {pi}{sup -} {mu}{sup +}{nu} using FOCUS data. FOCUS is a fixed target experiment at Fermilab that studies the physics of the charm quark. Particles containing charm are produced by photon-gluon fusion from the collision of a photon beam on a BeO target. The experiment is characterized by excellent vertex resolution and particle identification. The spectrometer consists of three systems for track reconstruction (two silicon systems and one multiwire proportional chamber system) and two magnets of opposite polarity. The polarity of the magnet is such that the events of e{sup +}e{sup -} pairs produced in the target (which constitutes the main background) travel through a central opening in the detectors without interactions. Particle momentum is measured from the deflection angle in the magnets. Three multicell Cerenkov counters are ...

2004-11-01

75

Particle Detection with drift Chambers  

CERN Document Server

Particle Detection with drift Chambers

2008-01-01

76

Stabilization and limit theorems for geometric functionals of Gibbs point processes  

CERN Document Server

Given a Gibbs point process $\\P^{\\Psi}$ on $\\R^d$ having a weak enough potential $\\Psi$, we consider the random measures $\\mu_\\la := \\sum_{x \\in \\P^{\\Psi} \\cap Q_\\la} \\xi(x, \\P^{\\Psi} \\cap Q_\\la) \\delta_{x/\\la^{1/d}}$, where $Q_{\\la} := [-\\la^{1/d}/2,\\la^{1/d}/2]^d$ is the volume $\\la$ cube and where $\\xi(\\cdot,\\cdot)$ is a translation invariant stabilizing functional. Subject to $\\Psi$ satisfying a localization property and translation invariance, we establish weak laws of large numbers for $\\la^{-1} \\mu_\\la(f)$, $f$ a bounded test function on $\\R^d$, and weak convergence of $\\la^{-1/2} \\mu_\\la(f),$ suitably centered, to a Gaussian field acting on bounded test functions. The result yields limit laws for geometric functionals on Gibbs point processes including the Strauss and area interaction point processes as well as more general point processes defined by the Widom-Rowlinson and hard-core model. We provide ...

2008-01-01

77

From Sakata Model to Goldberg-Ne'eman Quarks and Nambu QCD Phenomenology and "Right" and "Wrong" experiments  

CERN Document Server

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

2007-01-01

78

Some properties of low-mass stellar models with chemically inhomogeneous neutral-stability zones  

Energy Technology Data Exchange (ETDEWEB)

Several low-mass models with an inhomogeneous radiative core and a convective envelope are investigated, the entire core or its upper portion being treated as a zone of neutral stability. Mixing by convective overshoot will then give rise to unstable structure.

1983-03-01

79

Neutral endopeptidase inhibits prostate cancer cell migration by blocking focal adhesion kinase signaling  

UK PubMed Central (United Kingdom)

Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate...Full Text Available

2000-12-01

80

Doublet III vacuum vessel neutral beam armor  

Science.gov (United States)

The evolution of the Doublet III neutral beam armor is followed from the initial design of a radiation cooled metallic tile to the present actively cooled graphite design. Results of the thermal and stress analyses that dictated the present design are reviewed.

1979-11-01

81

RESEARCH REPORT 248 ON THE EQUILIBRIUM OF ELECTRON - NASA ...  

Science.gov (United States)

then, the toroidal containment of charged plasmas by electric fields is comparable to the toroidal containment of neutral plasmas using the ...

82

Mechanical Properties of Microelectronics Thin Films: Silicon ...  

Science.gov (United States)

... wherever possible. The primary interface for mechanical modeling is through PATRAN, a ... PATRAN Neutral File. PATRAN ...

1989-10-01

83

Fast Neutral Pressure Measurements in NSTX  

Energy Technology Data Exchange (ETDEWEB)

Several fast neutral pressure gauges have been installed on NSTX [National Spherical Torus Experiment] to measure the vessel and divertor pressure during inductive and coaxial helicity injected (CHI) plasma operations. Modified, PDX [Poloidal Divertor Experiment]-type Penning gauges have been installed on the upper and lower divertors. Neutral pressure measurements during plasma operations from these and from two shielded fast Micro ion gauges at different toroidal locations on the vessel mid-plane are described. A new unshielded ion gauge, referred to as the In-vessel Neutral Pressure (INP) gauge is under development.

2002-08-06

84

Codifying Information Assurance Controls for Department of ...  

Science.gov (United States)

... listed certifications are vendor (CCNA) and Server Plus (Server neutral such as the Certified Information S ... CCNA ITIL NET+ GSEC SECURITY+ ...

2010-03-01

86

The physics of production, acceleration and neutralization of large negative ion beams  

Energy Technology Data Exchange (ETDEWEB)

Neutral beam systems for the next generation of magnetic fusion devices will be based on negative ions. Development are progressing steadily, and large negative ion-based systems are prepared for JT60-U and LHD, and are being considered for ITER. An overview of the physics of the production, acceleration and neutralization of large negative ion beams is given. the present state of the art in Research and Development is also surveyed. (author). 55 refs., 10 figs., 1 tab.

1995-12-31

87

The physics of production, acceleration and neutralization of large negative ion beams  

Energy Technology Data Exchange (ETDEWEB)

Neutral beam systems for the next generation of magnetic fusion devices will be based on negative ions. Developments are progressing steadily, and large negative ion-based systems are under preparation for JT60-U and LHD, and are being considered for ITER. An overview of the physics of the production, acceleration and neutralization of large negative ion beams is given. The present state of the art in R and D is also surveyed. (Author).

1995-11-01

88

Photodetachment of negative ion beams in the presence of a background gas  

Energy Technology Data Exchange (ETDEWEB)

To suppress space charge blowup in an ion beam passing through a photoneutralizer, it is necessary to introduce some background gas. An analysis is presented of the neutralization of a high-energy, >200-keV negative deuterium ion beam, exposed to photodetachment while in the presence of deuterium. With a gas thickness of <0.01 Torr.cm, the neutral fraction in the output beam is found to be about the same as that gotten from the photoneutralizer operating in vacuum. Neutral atom beam injection for plasma heating is discussed.

1987-03-01

89

Development of neutral-beam injectors. Report on the third workshop, Gatlinburg, Tennessee, United States of America 19-23 October 1981  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on the third workshop on the development of neutral-beam injectors held from 19-23 October 1981 at Gatlinburg, Tennessee, USA. The programme of the workshop was devoted to the development of positive-ion-based neutral injectors, although several techniques for producing negative ion beams were also discussed.

1982-03-01

90

Laser: a Tool for Optimization and Enhancement of Analytical Methods  

Energy Technology Data Exchange (ETDEWEB)

In this work, we use lasers to enhance possibilities of laser desorption methods and to optimize coating procedure for capillary electrophoresis (CE). We use several different instrumental arrangements to characterize matrix-assisted laser desorption (MALD) at atmospheric pressure and in vacuum. In imaging mode, 488-nm argon-ion laser beam is deflected by two acousto-optic deflectors to scan plumes desorbed at atmospheric pressure via absorption. All absorbing species, including neutral molecules, are monitored. Interesting features, e.g. differences between the initial plume and subsequent plumes desorbed from the same spot, or the formation of two plumes from one laser shot are observed. Total plume absorbance can be correlated with the acoustic signal generated by the desorption event. A model equation for the plume velocity as a function of time is proposed. Alternatively, the use of a static laser beam for observation enables reliable determination of plume ...

1997-01-01

91

Correlation between particle size, in vivo particle persistence, and lung injury.  

UK PubMed Central (United Kingdom)

Dosimetry parameters such as deposition, clearance, retention, and translocation and dissolution of inhaled particles in and to different lung compartments may be important for the persistence of particles...Full Text Available

1994-10-01

92

rf-driven ion sources for industrial applications (invited) (abstract)  

Science.gov (United States)

The Plasma and Ion Source Technology Group at the Lawrence Berkeley National Laboratory have been developing rf-driven ion sources for the last two decades. These sources are being used to generate both positive and negative ion beams. Some of these sources are operating in particle accelerators such as the Spallation Neutron Source (SNS) at Oak Ridge, while others are being employed in various industrial ion beam systems. There are four areas where the rf-driven ion sources are commonly used in industry. (1) In semiconductor manufacturing, rf-driven sources have found important applications in plasma etching, ion beam implantation, and ion beam lithography. (2) In material analysis and surface modification, miniature rf-ion sources can be found in focused ion beam systems. They can provide ion beams of essentially any element in the Periodic Table. The newly developed combined rf ion-electron beam unit improves greatly the performance of the secondary ion mass ...

2008-02-15

93

HALO - the helium and lead observatory for supernova neutrinos  

Energy Technology Data Exchange (ETDEWEB)

The Helium and Lead Observatory (HALO) is a supernova neutrino detector under development for construction at SNOLAB. It is intended to fulfill a niche as a long term, low cost, high livetime, and low maintenance, dedicated supernova detector. It will be constructed from 80 tonnes of lead, from the decommissioning of the Deep River Cosmic Ray Station, and instrumented with approximately 384 meters of {sup 3}He neutron detectors from the final phase of the SNO experiment. Charged- and Neutral-Current neutrino interactions in lead expel neutrons from the lead nuclei making a burst of detected neutrons the signature for the detection of a supernova. Existing neutrino detectors are mostly of the water Cerenkov and liquid scintillator types, which are primarily sensitive to electron anti-neutrinos via charged-current interactions on the hydrogen nuclei in these materials. By contrast, the large neutron excess of a heavy nucleus like Pb acts to Pauli-block p)n ...

2008-11-01

94

Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization  

Energy Technology Data Exchange (ETDEWEB)

When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl{sub 2}, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the {epsilon}-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and {alpha}-helix form ...

2007-10-15

95

Effects of strong and electromagnetic correlations on neutrino interactions in dense matter  

Energy Technology Data Exchange (ETDEWEB)

An extensive study of the effects of correlations on both charged and neutral current weak interaction rates in dense matter is performed. Both strong and electromagnetic correlations are considered. The propagation of particle-hole interactions in the medium plays an important role in determining the neutrino mean free paths. The effects due to Pauli blocking and density, spin, and isospin correlations in the medium significantly reduce the neutrino cross sections. As a result of the lack of experimental information at high density, these correlations are necessarily model dependent. For example, spin correlations in nonrelativistic models are found to lead to larger suppressions of neutrino cross sections compared to those of relativistic models. This is due to the tendency of the nonrelativistic models to develop spin instabilities. Notwithstanding the above caveats, and the differences between nonrelativistic and relativistic approaches ...

1999-05-01

96

Electron collisional detachment processes for a 250 keV D/sup -/ ion beam in a partially ionized hydrogen target  

Energy Technology Data Exchange (ETDEWEB)

Neutral atom beams with energies above 200 keV may be required for various purposes in magnetic fusion devices following TFTR, JET and MFTF-B. These beams can be produced much more efficiently by electron detachment from negative ion beams than by electron capture by positive ions. We have investigated the efficiency with which such neutral atoms can be produced by electron detachment in partially ionized hydrogen plasma neutralizers.

1980-09-01

97

Radiochemical investigation of chalcogenide films. XI. Method for investigating sorption kinetics without separation of the phases  

Energy Technology Data Exchange (ETDEWEB)

The design of a reaction cell which permits the investigation of the sorption kinetics of microcomponents without separation of the phases under automated condition has been described. The use of thin-layer inorganic sorbents obtained by depositing films of a sorbing substance from aqueous solutions on flat substrates of small thickness makes it possible to determine the extent of sorption even at small values in the case of /beta/ emitters with a low energy and /alpha/ emitters. Detailed observation of the kinetics of isotopic exchange in the CdS-/sup 115m/Cd-HNO/sub 3/ system has made it possible to reveal at least four stages in the process during the time of observation.

1988-09-01

98

Long Range Correlation in Granular Shear Flow II: Theoretical Implications  

CERN Document Server

Numerical simulations are used to test the kinetic theory constitutive relations of inertial granular shear flow. These predictions are shown to be accurate in the dilute regime, where only binary collisions are relevant, but underestimate the measured value in the dense regime, where force networks of size $\\xi$ are present. The discrepancy in the dense regime is due to non-collisional forces that we measure directly in our simulations and arise from elastic deformations of the force networks. We model the non-collisional stress by summing over all paths that elastic waves travel through force networks. This results in an analytical theory that successfully predicts the stress tensor over the entire inertial regime without any adjustable parameters.

2006-01-01

99

Laser-fluorescence determination of trace uranium in hot spring water, geothermal water and tap water in Xi'an Lishan region  

International Nuclear Information System (INIS)

Using the Laser-Fluorescence technique, an investigation was made, adopting the standard mix method, on trace uranium concentrations in hot spring water and geothermal water from Lishan region, and in tap water from some major cities in Shanxi province. Totally 40 samples from 27 sites were investigated. Measurement showed that the tap water contains around 10"-"6 g/L of uranium, whose concentrations in both hot spring water and geothermal water are 10"-"5 g/L. Most of samples are at normal radioactive background level, some higher contents were determined in a few samples

2002-03-01

100

Data summary of municipal solid waste management alternatives  

Energy Technology Data Exchange (ETDEWEB)

The overall objective of the study in this report was to gather data on waste management technologies to allow comparison of various alternatives for managing municipal solid waste (MSW). The specific objectives of the study were to: 1. Compile detailed data for existing waste management technologies on costs, environmental releases, energy requirements and production, and coproducts such as recycled materials and compost. Identify missing information necessary to make energy, economic, and environmental comparisons of various MSW management technologies, and define needed research that could enhance the usefulness of the technology. 3. Develop a data base that can be used to identify the technology that best meets specific criteria defined by a user of the data base. Volume I contains the report text. Volume II contains supporting exhibits. Volumes III through X are appendices, each addressing a specific MSW management technology. Volumes XI and XII contain ...

1992-10-01

101

The effect of neutrals on the performance of plasma opening switches  

Energy Technology Data Exchange (ETDEWEB)

The authors address the question of the limitations on voltage and current transfer to loads in magnetic storage systems utilizing microsecond conduction time plasma opening switches. They propose that the limitation of performance results from neutral atoms that are not entrained into the ionized material that is driven by the magnetic field of the rising generator current. Evidence in support of this proposition is gathered from experiments performed on the Ace-4 and Hawk generators. They set forth a theory to describe the effect of neutrals on the electrical performance of plasma opening switches. The neutral gas is assumed to be present in the region between the moving plasma mass and the generator, primarily in the region in which the plasma is injected initially. The essential elements of the theory are a weak photoionization source to seed the gas with a low concentration of electrons, and joule heating accompanied ...

1996-12-31

102

Stability of space-charge neutralized beams  

Science.gov (United States)

Consideration is given to the stability of negative ion beams which are neutralized through ionization of a background gas. Two types of instabilities are examined. First, beam-plasma instabilities are analyzed with the dispersion relation showing that they are unimportant if the beam velocity is less than the electron thermal velocity. Second, results of a computer simulation on the flow of a cylindrical beam and the resulting background plasma show that when the background neutral gas density is less than or approximately equal to a critical density as instability occurs. This critical density is the density that would be needed to space-charge neutralize the beam if the positive ions were not retarded by the beam. An approximate dispersion relation indicates that the nature of the instability is a transverse positive-ion acoustic wave which couples to the beam.

1977-09-22

105

Investigation of Behaviorally Modified Rats for Use in ...  

Science.gov (United States)

... F;qure Title phge 20 Rat B Spectral Density Measurements TNT Stimuli 70 21 Rat B Spectral Density Measurements Neutral Stimuli 71 ...

1981-12-01

106

Interstellar PAH emission in the 11-14 micron region: new insights from laboratory data and a tracer of ionized PAHs  

Science.gov (United States)

The Ames infrared spectral database of isolated, neutral and ionized polycyclic aromatic

1999-01-01

107

A high sensitivity two-color interferometer for pulsed power plasmas  

International Nuclear Information System (INIS)

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

108

Space Radiation Detector with Spherical Geometry  

Science.gov (United States)

A particle detector is provided, the particle detector including a spherical Cherenkov detector, and

2011-01-01

109

Flawless start for world's mightiest particle collider  

CERN Document Server

Flawless start for world's mightiest particle collider

2008-01-01

111

Variation in the sensitivity of the mouse spermatogonial stem cell population to fission neutron irradiation during the cycle of the seminiferous epithelium  

Energy Technology Data Exchange (ETDEWEB)

Dose-response studies of the radiosensitivity of spermatogonial stem cells in various epithelial stages after irradiation with graded doses of fission neutrons of 1 MeV mean energy were carried out in the Cpb-N mouse. These studies on the stem cell population in stages IX-XI yielded simple exponential lines characterized by an average D0 value of 0.76 +/- 0.02 Gy. In the subsequent epithelial stages XII-III, a significantly lower D0 value of 0.55 +/- 0.02 Gy was found. In contrast to the curves obtained for stem cells in stages IX-III, the curves obtained in stages IV-VIII indicated the presence of a mixture of radioresistant and radiosensitive stem cells. In stage VII, almost no radioresistant stem cells appeared to be present and a D0 value for the radiosensitive stem cells of 0.22 +/- 0.01 Gy was derived. Previously, data were obtained on the size of colonies (in number of spermatogonia) derived from surviving stem cells. Combining these data with data from the ...

1986-12-01

112

Interinstitutional Variations in Planning for Stereotactic Body Radiation Therapy for Lung Cancer  

International Nuclear Information System (INIS)

Purpose: The aim of this study was to assess interinstitutional variations in planning for stereotactic body radiation therapy (SBRT) for lung cancer before the start of the Japan Clinical Oncology Group (JCOG) 0403 trial. Methods and Materials: Eleven institutions created virtual plans for four cases of solitary lung cancer. The created plans should satisfy the target definitions and the dose constraints for the JCOG 0403 protocol. Results: FOCUS/XiO (CMS) was used in six institutions, Eclipse (Varian) in 3, Cadplan (Varian) in one, and Pinnacle3 (Philips/ADAC) in one. Dose calculation algorithms of Clarkson with effective path length correction and superposition were used in FOCUS/XiO; pencil beam convolution with Batho power law correction was used in Eclipse and Cadplan; and collapsed cone convolution superposition was used in Pinnacle3. For the target volumes, the overall coefficient of variation was 16.6%, and the interinstitutional ...

2007-06-01

113

Spectrophotometric studies on the formation of adducts involved in synergistic extraction of uranium (IV) by mixtures of HTTA and neutral donors  

International Nuclear Information System (INIS)

Adduct formation between U(TTA)_4 and several neutral donor (S) was investigated by utilizing the changes in the absorption spectra of U(IV) resulting from the addition of neutral donors to a solution of U(TTA)_4. All the donors used in the present work from 1:1 adducts with U(TTA)_4. From the spectral changes, the equilibrium constants #beta#sub(AB) for the adduct formation reaction viz U(TTA)_4 S reversible U(TTA)_4.S were calculated for a few neutral donors. The log #beta#sub(AB) values obtained in benzene medium, are :TOPO (6.23), TBPO (6.13), TPPO (4.72), DBBP(4.04) TBP(3.04), TIOTP(1.27) and MIBK(-0.10) and a value of 3.98 for TOPO in chloroform medium. The adduct formation was found to result in increasing the coordination number of U(IV) from 8 in U(TTA)_4 to 9 in the adducts it forms with the neutral donors. Similar absorption spectral studies with U(DBM)_4 revealed that it forms much weaker ...

1979-01-01

114

Effect of UV radiation on the killer phenotype in the wine yeast-saccharomycetes and spontaneous variation of this character  

International Nuclear Information System (INIS)

Spontaneous and ultraviolet-induced changeabilities of wine yeasts from the killer state to sensitive one have been studied. Observed often spontaneous changes of killer and neutral phenotypes under laboratory store conditions as well as high mutation frequency of genetic elements responsible for the killer indication on ultraviolet irradiation testify that often encounterability in nature and in the production of sensitive yeasts is attributed to high frequency of mutation changes of the killer and neutral phenotypes to the sensitive state.

115

Doublet III limiter/armor update  

Energy Technology Data Exchange (ETDEWEB)

The Doublet III device is operating with an extensive system of plasma limiters and wall protective armor. Operations with up to 8MW of neutral beam power and 1.5MA plasma current are planned. Design and operational performance of the following systems are discussed: 1. Water-cooled graphite moveable limiter. 2. Water-cooled graphite fixed limiter and neutral beam wall armor. 3. Radiatively cooled Inconel divertor plates.

1983-12-01

116

Dissipativity for linear neutral distributed parameter systems: LOI approach  

British Library Electronic Table of Contents (United Kingdom)

In this work dissipativity of linear neutral distributed parameter systems has been addressed. Delay-dependent sufficient conditions for the dissipativity with respect to the infinite-dimensional version of energy supply rate (Q"1,S"1,R"1) characterized exclusively by unbounded operator Q"1 are established in terms of linear operator inequalities (LOIs). Finally, the 3-dimensional heat equation illustrates our result.

2012-01-01

117

Dengue Plaque Reduction Neutralization Test (PRNT) in Primary and Secondary Dengue Virus Infections: How Alterations in Assay Conditions Impact Performance  

UK PubMed Central (United Kingdom)

Dengue virus (DENV) infection is a worsening global health problem. The plaque reduction neutralization test (PRNT) is currently considered to be the “gold standard” to characterize...Full Text Available

2009-11-01

118

A note on asymptotic stability of an interval neutral delay-differential system  

British Library Electronic Table of Contents (United Kingdom)

This paper mainly considers the asymptotic stability of interval neutral delay-differential systems, which corrects a technical error in the proof given in [Applied Math. Letters, 16(2003) 1063-1068] by a linear fractional transformation of an interconnection matrix with structured real parametric uncertainties. In addition, a new condition, in terms of the structured singular value, is provided to ensure the stability of the interval system. Finally, an example is given to demonstrate the validity of our criteria.

2012-01-01

119

A magnetically insulated negative ion source for neutral beam heating  

Energy Technology Data Exchange (ETDEWEB)

A new, magnetically insulated negative ion source has recently been discovered which can produce pulsed negative ion beams (H/sup -/, Li/sup -/, and C/sup -/) with intensities of 100-300 A/cm/sup 2/ at 1-4 MeV. This source may provide the basis for a high energy neutral beam system for heating large tokamaks.

1983-08-01

120

The edge of neutral evolution in social dilemmas  

Energy Technology Data Exchange (ETDEWEB)

The functioning of animal as well as human societies fundamentally relies on cooperation. Yet, defection is often favorable for the selfish individual, and social dilemmas arise. Selection by individuals' fitness, usually the basic driving force of evolution, quickly eliminates cooperators. However, evolution is also governed by fluctuations that can be of greater importance than fitness differences, and can render evolution effectively neutral. Here, we investigate the effects of selection versus fluctuations in social dilemmas. By studying the mean extinction times of cooperators and defectors, a variable sensitive to fluctuations, we are able to identify and quantify an emerging 'edge of neutral evolution' that delineates regimes of neutral and Darwinian evolution. Our results reveal that cooperation is significantly maintained in the neutral regimes. In contrast, the ...

2009-09-15

121

TPX Neutral Beam Injection System design  

International Nuclear Information System (INIS)

The existing Tokamak Fusion Test Reactor Neutral Beam system is proposed to be modified for long pulse operation on the Tokamak Physics Experiment (TPX). Day one of TPX will call for one TFTR beamline modified for 1000 second pulse lengths oriented co-directional to the plasma current. The system design will be capable of accommodating an additional co-directional and a single counter directional beamline. For the TPX conceptual design, every attempt was made to use existing Neutral Beam hardware, plant facilities, auxiliary systems, service infrastructure, and control systems. This paper describes the moderate modifications required to the power systems, the ion sources, and the beam impinged surfaces of the ion dumps, the calorimeters, the various beam scrapers, and the neutralizers. Also described are the minimal modifications required to the vacuum, cryogenic, and gas systems and the major modification of replacing the ...

1993-10-11

122

Development and application of technology-neutral safety requirements for the regulation of new nuclear power reactors  

International Nuclear Information System (INIS)

This paper explores the current trends in development of technology-neutral safety requirements to be used in the regulation of future nuclear power reactors and the role of the quantitative safety goals in the design of reactor safety systems. Establishing the requirements concerning the reliability of safety functions rather than on particular systems employed to achieve the functions, as well as the use of the recommendations of the International Commission on Radiological Protection (ICRP) on protection against potential exposure could form the basis of a technology-neutral framework for safety requirements on new reactor designs. Also it could contribute to international harmonisation of nuclear safety assessment practices as part of the licensing processes for future nuclear power plants. (author)

2009-10-12

123

Acoustic band gaps in arrays of neutral inclusions  

British Library Electronic Table of Contents (United Kingdom)

We analyse numerically the acoustic stop band properties of an array of orthotropic coated cylinders whose elastic parameters are deduced from a geometric transform [H. Chen, C.T. Chan, Acoustic cloaking in three dimensions using acoustic metamaterials, Appl. Phys. Lett. 91 (2007) 183518]. We find that whereas a single coated inclusion is acoustically neutral at any frequency, an array of them might display some stop bands. More precisely, an array of freely vibrating coated voids is always neutral, whereas an array of clamped coated inclusions might display a zero frequency stop band. Interestingly, an array of radially symmetric coated inclusions behaves as local Helmholtz resonators, for which the eigenfield within each cloak is obtained in closed form, leading to a frequency estimate a...

2010-01-01

124

A nontoxic antitumour compound from the leaves of Bauhinia scandens characterized as 1-O-alkyl glycerol by gas-liquid chromatography and evaluation of its antitumour property by Brine Shrimp bioassay  

British Library Electronic Table of Contents (United Kingdom)

This is a report of extraction and identification of 1-O-alkyl glycerol present in the dried leaves of Bauhinia scandens. Fifty percent aqueous ethanolic extract of the plant at room temperature was fractionated over petroleum ether and diethyl ether. The diethyl ether soluble fraction showed positive bioactivity in Brine Shrimp bioassay. Isolation and purification of the active principle was subsequently done from diethyl ether fraction. The diethyl ether fraction was separated into acidic and neutral part. The acid free fraction was screened to be positive in Brine Shrimp bioassay. The NMR spectra (in CDCl3) indicated the probability of its lipoidal nature. The total lipid fraction was resolved into neutral, glyco, and phospho-lipids by column chromatography. Only the neutral fraction sh...

2008-01-01

130

Solid particle receiver experiments: velocity measurements  

Energy Technology Data Exchange (ETDEWEB)

Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.

1984-10-01

131

Solid particle receiver experiments: velocity measurements  

Science.gov (United States)

Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.

1984-10-01

132

Small world when building a particle detector prototype, the devil is in the tiny details  

CERN Multimedia

Small world when building a particle detector prototype, the devil is in the tiny details

2004-01-01

133

Particle-Sizing System for Scanning Electron Microscope ...  

Science.gov (United States)

... THESIS PARTICLE-SIZING SYSTEM FOR SCANNING ELECTRON MICROSCOPE IMAGES OF SOLID-PROPELLANT COMBUSTION EXHAUST ...

1991-03-01

134

Fragmentation of nuclei by particles and nuclei of intermediate and high energies  

Energy Technology Data Exchange (ETDEWEB)

The present state of investigations into the fragmentation of target nuclei by particles and nuclei of intermediate and high energies is reviewed.

1983-11-01

135

Loss of light charged particles by nuclear interactions in BaF[sub 2] crystals  

Energy Technology Data Exchange (ETDEWEB)

The nuclear interaction probability of light charged particles in BaF[sub 2] crystals has been studied as a function of the incident particle energy. Light charged particles were identified in charge and mass by measuring their magnetic rigidity and their time-of-flight. The percentage of particles undergoing nuclear interactions has been measured for particles of charge from Z=1 to Z=6 and the experimental data are compared with the results of a model calculation. (orig.)

1993-07-15

136

The radiosensitivity of spermatogonial stem cells in C3H/101 F[sub 1] hybrid mice  

Energy Technology Data Exchange (ETDEWEB)

The radiosensitivity of spermatogonial stem cells of C3H/HeHx101/H F[sub 1] hybrid mice was determined by counting undifferentiated spermatogonia at 10 days after X-irradiation. During the spermatogenic cycle, differences in radiosensitivity were found, which were correlated with the proliferative activity of the spermatogonial stem cells. In stage VIII[sub irr], during quiescence, the spermatogonial stem cells were most radiosensitive with a D[sub 0] of 1.4 Gy. In stages XI[sub irr]-V[sub irr], when the cells were proliferatively active, the D[sub 0] was about 2.6 Gy. Based on the D[sub 0] values for sensitive and resistant spermatogonia and on the D[sub 0] for the total population, a ratio of 45:55% of sensitive to resistant spermatogonial stem cells was estimated for cell killing. When the present data were compared with data on translocation induction obtained in mice of the same genotype, a close fit was obtained when the translocation yield (Y; in % abnormal ...

1993-12-01

137

Leak-Before-Break: Further developments in regulatory policies and supporting research  

Energy Technology Data Exchange (ETDEWEB)

The fourth in a series of international Leak-Before-Break (LBB) Seminars supported in part by the US Nuclear Regulatory Commission was held at the National Central Library in Taipei, Taiwan on May 11 and 12, 1989. The seminar updated the international polices and supporting research on LBB. Attendees included representatives from regulatory agencies, electric utilities, nuclear power plant fabricators, research organizations, and academic institutions. Regulatory policy was the subject of presentations by Mr. G. Arlotto (US NRC, USA) Dr. B. Jarman (AECB, Canada), Dr.P. Milella (ENEA-DISP, Italy), Dr. C. Faidy (EDF/Septen, France ), and Dr. K. Takumi (NUPEC, Japan). A paper by Mr. K. Wichman and Mr. A. Lee of the US NRC Office of Nuclear Reactor Regulation is included as background material to these proceedings; it discusses the history and status of LBB applications in US nuclear power plants. In addition, several papers on the supporting research programs described regulatory policy ...

1990-02-01

138

Data summary of municipal solid waste management alternatives. Volume 2, Exhibits  

Energy Technology Data Exchange (ETDEWEB)

The overall objective of the study in this report was to gather data on waste management technologies to allow comparison of various alternatives for managing municipal solid waste (MSW). The specific objectives of the study were to: 1. Compile detailed data for existing waste management technologies on costs, environmental releases, energy requirements and production, and coproducts such as recycled materials and compost. Identify missing information necessary to make energy, economic, and environmental comparisons of various MSW management technologies, and define needed research that could enhance the usefulness of the technology. 3. Develop a data base that can be used to identify the technology that best meets specific criteria defined by a user of the data base. Volume I contains the report text. Volume II contains supporting exhibits. Volumes III through X are appendices, each addressing a specific MSW management technology. Volumes XI and XII contain ...

1992-10-01

139

Comparison of Si and InSb as the normal layer of S-N-S junctions  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on superconductor-semiconductor-superconductor (S-N-S) weak-link junctions with the normal layer of Si or InSb thin films were prepared by using focused ion beam (FIB), and electrical properties were measured. Whereas InSb thin films on single crystals did not have an intrinsic mobility, S-N-S junction with InSb shows the characteristics of Josephson S-N-S junction. A 200nm-thick film of InSb deposited on MgO had a mobility of 83 cm{sup 2}.V {center dot} s and a carrier density of 6.5 {times} 10{sup 17} cm{sup {minus}3} at 4.2K. The coherence length {xi}{sub n} was computed to be 17 nm from these experimental data, and we obtained critical superconducting current Ic of 100 {mu} A for the S-N-S junction which had a line width of 10{mu} m and a channel length of 20 nm.

1991-03-01

140

Variation in the action spectrum of erythrolabe among deuteranopes.  

UK PubMed Central (United Kingdom)

1. Eight deuteranopes matched a mixture of a monochromatic light on the long wave side of the neutral point and a violet (450 nm) primary to a fixed white as well as a monochromatic light on the short...Full Text Available

1977-04-01

141

Tat-Neutralizing Antibodies in Vaccinated Macaques  

UK PubMed Central (United Kingdom)

The human immunodeficiency virus Tat protein is essential for virus replication and is a candidate vaccine antigen. Macaques immunized with Tat or chemically modified Tat toxoid having the same clade...Full Text Available

2003-03-01

142

Tachyons  

International Nuclear Information System (INIS)

Arguments in favour of the possibility of the existence and the non-existence of tachyons are put forward. Some of the theoretical and experimental attempts which have either supported the view that tachyons exist or not are mentioned. In the light of evidence, available as of now, it is surmised that they may not exist and if they do, they may be neutral in charge. (K.B.).

143

Safety and immunogenicity of a vaccine bait containing ERA strain of attenuated rabies virus.  

UK PubMed Central (United Kingdom)

Ninety percent of foxes fed commercial ERA vaccine in a specially designed bait developed rabies serum neutralizing antibodies. The vaccine bait did not cause clinical signs of rabies when consumed...Full Text Available

1987-10-01

144

Progress report on negative ion beams based on User Development Workshop on negative ion based neutral beams, 15-16 February, 1983, Princeton  

International Nuclear Information System (INIS)

Progress in the development of negative ion sources and their application in fusion research is reviewed. (U.K.).

1983-04-18

145

Organ-Specific Invertase Deficiency in the Primary Root of an Inbred Maize Line 1  

UK PubMed Central (United Kingdom)

An organ-specific invertase deficiency affecting only the primary root system is described in the Oh 43 inbred maize (Zea mays). Invertases (acid and neutral/soluble and insoluble)...Full Text Available

1991-10-01

146

Mechanism of L-glutamate transport in membrane vesicles from Bacillus stearothermophilus.  

UK PubMed Central (United Kingdom)

In the presence of electrochemical energy, several branched-chain neutral and acidic amino acids were found to accumulate in membrane vesicles of Bacillus stearothermophilus. The membrane vesicles contained...Full Text Available

1989-02-01

147

Laboratory Evaluation of Base Materials for Neutralization of the Contaminated Aquifer at the F-Area Seepage Basins  

Energy Technology Data Exchange (ETDEWEB)

Laboratory studies were performed to support field-testing of base injection into the F-Area Seepage Basins groundwater. The general purpose of these experiments is to provide information to guide the test of base injection and to identify potential adverse effects.

2001-09-11

148

Immunization of foxes by the intestinal route using an inactivated rabies vaccine.  

UK PubMed Central (United Kingdom)

Approximately 30% of foxes given two doses of an inactivated rabies antigen delivered directly into the intestinal tract developed an immune response as measured by rabies serum neutralizing antibodies....Full Text Available

1989-01-01

149

FIELD CORROSION TESTS IN REDOX AND PUREX UNDERGROUND WASTE STORAGE TANKS  

Science.gov (United States)

A corrosion-testing program has been initiated in Purex and Redox storage tnnks to obtain corrosion data on carbon steel and three associated materials in neutralized process wastes. (C.W.H.)

1955-06-28

150

Effect of crevice environment PH on corrosion damage of horizontal steam generator tubes  

Energy Technology Data Exchange (ETDEWEB)

In support of a project on lifetime calculation experiments were carried out to evaluate the resistance to environmentally assisted cracking (EAC) of steam generator tubes during operation. Estimations of the incubation period for crack initiation and the threshold K value, K{sup Iscc}, and the crack growth rate were made to predict evolution of damage in tube walls. The paper summarizes results of experiments of C ring specimen for the initiation testing and results of SENT (single edge notch tensile) specimen for the crack growth rate (CGR) testing. The specimens were exposed to concentrated environments at elevated temperatures simulating crevice environments in secondary side crevices in horizontal steam generators. The results show that the material of SG tubes is sensitive to transgranular environmentally assisted cracking in the three basic concentrated environments used, alkaline, neutral and acid. The most corrosive medium was the acid environment. The ...

2002-07-01

151

Effect of crevice environment PH on corrosion damage of horizontal steam generator tubes  

International Nuclear Information System (INIS)

In support of a project on lifetime calculation experiments were carried out to evaluate the resistance to environmentally assisted cracking (EAC) of steam generator tubes during operation. Estimations of the incubation period for crack initiation and the threshold K value, K"I"s"c"c, and the crack growth rate were made to predict evolution of damage in tube walls. The paper summarizes results of experiments of C ring specimen for the initiation testing and results of SENT (single edge notch tensile) specimen for the crack growth rate (CGR) testing. The specimens were exposed to concentrated environments at elevated temperatures simulating crevice environments in secondary side crevices in horizontal steam generators. The results show that the material of SG tubes is sensitive to transgranular environmentally assisted cracking in the three basic concentrated environments used, alkaline, neutral and acid. The most corrosive medium was the acid environment. The crack ...

2002-05-05

152

Comparison of a Commercial Multiplex Real-Time PCR to the Cell Cytotoxicity Neutralization Assay for Diagnosis of Clostridium difficile Infections?  

UK PubMed Central (United Kingdom)

A commercial multiplex real-time PCR assay (Cepheid Xpert C. difficile assay) for the diagnosis of Clostridium difficile infection was evaluated. The sensitivity and...Full Text Available

2009-11-01

153

Chemical neutralization to control denting in nuclear steam generators  

International Nuclear Information System (INIS)

Laboratory testing at Combustion Engineering has indicated promise in controlling simulated steam generator tube denting through chemical neutralization. Testing was limited to on-line treatment, and two neutralizers have been evaluated: calcium hydroxide and boric acid. On-line treatment with calcium hydroxide successfully halted active denting whenever the bulk calcium concentration (in ppm) equaled or exceeded the bulk chloride concentration (in ppm). Calcium hydroxide also was effective as an alternative to ammonia as a pH controlling agent in two tests conducted without ingress of chloride. On-line treatment with boric acid consisted of a four-day soak at simulated low (approximately 30 percent) power with 50 ppm B followed by one month full-power operation with 10 ppm B. This treatment also halted denting. Nondestructive and destructive examination of test boilers gave no indication of adverse side effects associated with either ...

154

Characterization of amino acid transport in membrane vesicles from the thermophilic fermentative bacterium Clostridium fervidus.  

UK PubMed Central (United Kingdom)

Amino acid transport was studied in membrane vesicles of the thermophilic anaerobic bacterium Clostridium fervidus. Neutral, acidic, and basic as well as aromatic amino acids were transported at 40...Full Text Available

1989-07-01

155

Amino acid transport in the thermophilic anaerobe Clostridium fervidus is driven by an electrochemical sodium gradient.  

UK PubMed Central (United Kingdom)

Amino acid transport was studied in membranes of the peptidolytic, thermophilic, anaerobic bacterium Clostridium fervidus. Uptake of the negatively charged amino acid L-glutamate, the neutral amino...Full Text Available

1993-04-01

156

Ab binding alters gene expression in Cryptococcus neoformans and directly modulates fungal metabolism  

UK PubMed Central (United Kingdom)

Abs facilitate humoral immunity via the classical mechanisms of opsonization, complement activation, Ab-dependent cellular cytotoxicity, and toxin/viral neutralization. There is also evidence that some...Full Text Available

2010-04-01

157

A dry element  

Energy Technology Data Exchange (ETDEWEB)

The agglomerate for the element is made from activated charcoal powder, an electrically conducting additive and a neutral electrolyte. The activated charcoal makes up 30 to 50 percent of the weight of the agglomerate. It is a mixture of hydrophobized and unhydrophobized powder in a ratio of 85 to 70 to 15 to 30. The element has high discharge characteristics.

1983-08-11

158

Trapping of neutral atoms with resonant microwave radiation  

Energy Technology Data Exchange (ETDEWEB)

We duscuss a resonant microwave trap for neutral atoms. Because of the long spontaneous radiation time this trap is remarkably different from the optical trap. It also has advantages over static magnetic traps that trap the excited spin state of the lowest electronic level, in that atoms predominantly in the spin ground state can be trapped. We analyze the relaxation-ejection lifetime of atoms in such a trap using the formalism of dressed atomic states. Results are appliedi to atomic hydrogen and the possibility of Bose-Einstein condensation is considered.

1989-05-15

159

The High-Redshift Neutral Hydrogen Signature of an Anisotropic Matter Power Spectrum  

CERN Document Server

An anisotropic power spectrum will have a clear signature in the 21cm radiation from high- redshift hydrogen. We calculate the expected power spectrum of the intensity fluctuations in neutral hydrogen from before the epoch of reionization, and predict the accuracy to which future experiments could constrain a quadrupole anisotropy in the power spectrum. We find that the Square Kilometer Array will have marginal detection abilities for this signal at z~17 if the process of reionization has not yet started; reionization could enhance the detectability substantially. Pushing to higher redshifts and higher sensitivity will allow highly precise (percent level) measurements of anisotropy.

2011-01-01

160

Removal of boron from aqueous solution by using neutralized red mud  

International Nuclear Information System (INIS)

The adsorptive removal of boron from aqueous solution by using the neutralized red mud was studied in batch equilibration technique. The effects of pH, adsorbent dosage, initial boron concentration and contact time on the adsorption were investigated. The experiments demonstrated that boron removal was of a little fluctuation in pH range of 2-7 and it takes 20 min to attain equilibrium. The adsorption data was analyzed using the Langmuir and the Freundlich isotherm models and it was found that the Freundlich isotherm model represented the measured sorption data well.

2007-04-02

161

Origins of acid fluids in geothermal reservoirs  

International Nuclear Information System (INIS)

Acid fluids in geothermal reservoirs are rare. Their occurrence in geothermal systems associated with recent volcanism (Tatun Sumikawa, Miravalles) probably indicates that the geotherml reservoir fluid was derived from volcanic fluid incompletely neutralized by reaction with feldspars and micas. Superheated steam containing HCl (Larderello, The Geysers) forms acid where it condenses or mixes with liquid at moderate temperatures (325 deg. C). Cryptoacidity occurs at Los Humeros where HCl acidity is formed and neutralized without reaching the surface. (author). 28 refs, 9 figs, 2 tabs.

1992-03-01

162

Optogalvanic isotope enrichment of Cu ions in Cu-Ne positive column discharges  

Energy Technology Data Exchange (ETDEWEB)

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

1983-07-01

163

On the stability of the Einstein static universe  

Energy Technology Data Exchange (ETDEWEB)

We show using covariant techniques that the Einstein static universe containing a perfect fluid is always neutrally stable against small inhomogeneous vector and tensor perturbations and neutrally stable against adiabatic scalar density inhomogeneities so long as c{sup 2}{sub s} > 1/5, and unstable otherwise. We also show that the stability is not significantly changed by the presence of a self-interacting scalar field source, but we find that spatially homogeneous Bianchi type IX modes destabilize an Einstein static universe. The implications of these results for the initial state of the universe and its pre-inflationary evolution are also discussed. (letter to the editor)

2003-06-07

164

On the stability of the Einstein static universe  

International Nuclear Information System (INIS)

We show using covariant techniques that the Einstein static universe containing a perfect fluid is always neutrally stable against small inhomogeneous vector and tensor perturbations and neutrally stable against adiabatic scalar density inhomogeneities so long as c"2_s > 1/5, and unstable otherwise. We also show that the stability is not significantly changed by the presence of a self-interacting scalar field source, but we find that spatially homogeneous Bianchi type IX modes destabilize an Einstein static universe. The implications of these results for the initial state of the universe and its pre-inflationary evolution are also discussed. (letter to the editor)

2003-06-07

165

Extraction of lithium from neutral salt solutions with fluorinated #beta#-diketones  

International Nuclear Information System (INIS)

Lithium was selectively extracted from near-neutral aqueous solutions of alkali metal salts. The mechanism by which this was achieved involves the formation of the trioctylphosphine oxide adduct of a lithium chelate of a fluorinated #beta#-diketone, which is then readily extractable into an organic diluent. High separation factors were obtained from sodium, potassium, rubidium, and cesium. The selectivity of the fluorinated #beta#-diketones for lithium over the alkaline earths was found to be poor. A suggested general flowsheet for the recovery of lithium from a salt brine concentrate is included. (author).

166

An experimental investigation of the Hahn-Noll revenue neutral auction for emissions licenses  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on three series of laboratory experiments designed to test the performance of the Hahn-Noll revenue neutral auction (RNA). An alternative institution, a no-rebate uniform price auction (UPA), is also examined as a benchmark. In these experiments, the RNA markets were little different from UPA markets in terms of either prices or market efficiencies. The two institutions did differ in terms of the distribution of the gains from exchange and of the propensity of bidders to engage in a certain type of overbidding. 25 refs., 13 figs., 3 tabs.

1993-01-01

167

Formation of particles in combustion of biofuels  

International Nuclear Information System (INIS)

Biomass combustion is an important part in a sustainable energy system, but as well a source of submicron (particles < 1 #mu#m) particles in the air. Consequently, to obtain a good air quality together with increased biomass combustion there is a need for a better understanding of particle formation. This work is a part of a larger project about formation and emissions of particles from biofuel combustion. The report includes the work performed in the project during the year 2004. The aim of the project is to describe the release of inorganic components, which cause particle emissions, during combustion of single fuel particles of biofuel, e.g. wood pellets. The work is carried out by emission measurements, systematic combustion experiments and modelling work. The results are expected to contribute to the understanding of which parameters that influence the ...

168

X-RAY MICROANALYSIS OF A RADIOACTIVE PARTICLE WITH THE AID OF THE ELECTRON MICROSCOPE  

Science.gov (United States)

A radioactive particle was analyzed to discover the composition of the inactive material of the particle. The method uses the x-ray line spectrum of the K series caused by electron irradiation of the particle in the electron microscope. Iron and aluminum or silicon (the last two could not be distinguished) were found as inactive components in the particle. (D.L.C.)

1962-07-28

169

Method of removing entrained particles from flue gas and composition of matter  

Energy Technology Data Exchange (ETDEWEB)

A composition of matter to treat particles entrained in flue gas, is described comprising: a caustic liquid used to adjust resistivity of the entrained particles; and inert particulate matter supporting the caustic liquid for inhibiting chemical action of the caustic liquid until used to adjust the resistivity of the entrained particles, the inert particulate matter supporting sufficient caustic liquid to adjust the resistivity of the entrained particles.

1988-04-19

170

Metal nanoparticle inks  

Energy Technology Data Exchange (ETDEWEB)

Stabilized silver particles comprise particles comprising silver, a short-chain capping agent adsorbed on the particles, and a long-chain capping agent adsorbed on the particles. The short-chain capping agent is a first anionic polyelectrolyte having a molecular weight (Mw) of at most 10,000, and the long-chain capping agent is a second anionic polyelectrolyte having a molecular weight (Mw) of at least 25,000. The stabilized silver particles have a solid loading of metallic silver of at least 50 wt %.

2011-04-12

171

Magnetic flocculation and filtration  

Energy Technology Data Exchange (ETDEWEB)

A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

1996-10-01

172

Continuous flow dielectrophoretic particle concentrator  

Energy Technology Data Exchange (ETDEWEB)

A continuous-flow filter/concentrator for separating and/or concentrating particles in a fluid is disclosed. The filter is a three-port device an inlet port, an filter port and a concentrate port. The filter separates particles into two streams by the ratio of their dielectrophoretic mobility to their electrokinetic, advective, or diffusive mobility if the dominant transport mechanism is electrokinesis, advection, or diffusion, respectively.Also disclosed is a device for separating and/or concentrating particles by dielectrophoretic trapping of the particles.

2007-04-17

173

U of C site vies for new particle accelerator  

CERN Multimedia

"American dominance in the study and development of high-energy particle physics may be seriously compromised, according to a report issued by the National Academy of Sciences, unless efforts are made to ensure that the next high-energy particle accelerator - the International Linear Collider (ILC) - will be constructed in the U.S.

2006-01-01

174

Search for free quarks at PEP  

Energy Technology Data Exchange (ETDEWEB)

The results of a search for fractionally charged particles produced in e/sup +/e/sup -/ annihilation at 29 GeV/c/sup 2/ are discussed. Results from cosmic-ray searches for fractionally charged particles, tachyons, and massive particles using the same detector are also presented.

1982-01-01

175

Particle creation if a cosmic string snaps  

CERN Document Server

We calculate the Bogolubov coefficients for a metric which describes the snapping of a cosmic string. If we insist on a matching condition for all times {\\it and} a particle interpretation, we find no particle creation.

1994-01-01

176

Entropic effects in channel-facilitated transport: Inter-particle interactions break the flux symmetry  

UK PubMed Central (United Kingdom)

We analyze transport through conical channels due to the difference in particle concentration on the two sides of the membrane. Because of the detailed balance, fluxes of non-interacting particles...Full Text Available

2009-08-01

177

Characterization of Two Unique Cholesterol-Rich Lipid Particles Isolated from Human Atherosclerotic Lesions  

UK PubMed Central (United Kingdom)

The authors' laboratory, using histochemicalmethods, previously identified two types of cholesterol-containing lipid particles in the extracellular spaces of human atherosclerotic lesions, one particle...Full Text Available

1990-01-01

178

A new method for quantifiable and controlled dosage of particulate matter for in vitro studies: the electrostatic particulate dosage and exposure system (EPDExS).  

Science.gov (United States)

An exposure chamber is described for the quantifiable addition of fine and ultrafine aerosol particulate matter directly to cells and used to demonstrate the in vitro cytotoxicity of fine 1,4-naphthoquinone particles to murine lung epithelial cells. The electrostatic particulate dosage and exposure system (EPDExS) operates on the principle of electrostatic precipitation and is shown to deposit fine and ultrafine aerosol particles directly to cells with 100% efficiency for particle diameters in the range of 40-530nm. This range is not limited by the EPDExS, but rather by the aerosolization method used for this study. Numbers of particles deposited onto the cells are counted with a condensation particle counter, negating any need to calculate or estimate particle exposure. The process of particle introduction, assessed using Trypan blue dye ...

2008-06-08

179

Wear particle equilibrium measurements and their significance  

Energy Technology Data Exchange (ETDEWEB)

Ferrography is a technique for isolating wear particle debris from lubricating and hydraulic oils, the presence of which carry with them a history of the wear processes in the machine. Thus, the technique has fundamental applications in machine condition monitoring and failure prevention. The wear particles are significant in the metal types that are present in the particle distribution as an indication of the wearing machine components and in the particle size distribution and morphology which indicates the severity of wear in the system. In this paper, the fundamental principles which describe the working of the ferrograph, concentrating on the working of the on-line ferrograph are discussed. The significance of equilibrium particle concentration in the oil system and its measurement using the ferrograph are also discussed.

1980-11-01

180

Thermal performance and design of a solid particle cavity receiver  

Energy Technology Data Exchange (ETDEWEB)

A model for energy transport in a solid particle cavity receiver is developed and applied to the design and analysis of a receiver for the Central Receiver Test Facility (CRTF), Albuquerque, New Mexico. The model gives thermal performance results - including particle temperatures, cavity efficiencies, and wall temperatures - which directly affect the economic and technical feasibility of a solid particle receiver. In addition, design criteria relevant to the configuration of a solid particle cavity receiver are developed. Results for CRTF indicate that at design conditions particle temperatures will exceed 1200/sup 0/K with cavity efficiencies on the order of 75%.

1985-04-01

181

UARS Particle Environment Monitor (PEM) Level 3AT - Mirador - NASA  

Science.gov (United States)

May 11, 2011 ... The Particle Environment Monitor (PEM) on NASA's Upper Atmosphere Research Satellite (UARS) measures the type, amount, energy, and ...

184

Smooth Particle Hydrodynamics for Surf Zone Waves  

Science.gov (United States)

... Zou, S. and RA Dalrymple, ``Coastal Sediment Transport Simulation by Smoothed Particle Hydrodynamics,'' Journal of Waterways, Ports, Coastal ...

2011-05-15

185

Non-equilibrium particle emission in 45 MeV #alpha# particle bombardment of "1"5"9Tb  

International Nuclear Information System (INIS)

Mar 1982. p. 36-37. Germany Didelez, JP Paris-11 Univ., 91 - Orsay (France).

1982-03-01

186

Monosodium titanate particle characterization  

Energy Technology Data Exchange (ETDEWEB)

A characterization study was performed on monosodium titanate (MST) particles to determine the effect of high shear forces expected from the In-Tank Precipitation (ITP) process pumps on the particle size distribution. The particles were characterized using particle size analysis and scanning electron microscopy (SEM). No significant changes in particle size distributions were observed between as-received MST and after 2--4 hours of shearing. Both as-received and sheared MST particles contained a large percentage of porosity with pore sizes on the order of 500 to 2,000 Angstroms. Because of the large percentage of porosity, the overall surface area of the MST is dominated by the internal surfaces. The uranium and plutonium species present in the waste solution will have access to both interior and exterior surfaces. Therefore, uranium and plutonium loading should ...

1993-01-12

187

Mechanical properties of surface composite particles coated with finer particles; Hyomen hifukugata fukuto biryushiso no rikigaku tokusei  

Energy Technology Data Exchange (ETDEWEB)

The effect of the coated composite surface of particles on the mechanical properties of the powder bed was investigated. Polyethylene-silica surface composite powder was prepared at several coating ratios with Hybridizer. Various tests on mechanical properties of the powder bed were carried out with the prepared powder, and the following results were obtained: The ultimate tensile strength depends only on the cohesive force between particles, and the contact probability model of composite particles led to good agreement between the experimental and calculated values. The coefficient of internal friction and cohesive shear strength were influenced due to the interlocking effect of the surface roughness of composite particles. The effects of coating particles became small with dynamic properties like angle of repose. It is possible to control the mechanical properties in a step wise ...

1996-05-10

188

Experts worry US may lose leadership in particle physics  

CERN Multimedia

"Physics in the United States is in a crisis that the country may lose the leadership in basic particle research in coming years, a report of the National Research Council warned." (1 page)

2006-01-01

189

Airborne minerals and related aerosol particles: Effects on climate and the environment  

UK PubMed Central (United Kingdom)

Aerosol particles are ubiquitous in the troposphere and exert an important influence on global climate and the environment. They affect climate through scattering, transmission, and absorption of...Full Text Available

1999-03-30

190

Passivation behavior of SUS 304 stainless steel in neutral solutions at elevated temperature  

International Nuclear Information System (INIS)

Cyclic voltammograms of SUS 304 stainless steel in various neutral solutions such as Na_2SO_4 at high temperature were measured, as a successive study to previous report in which effects of temperature and pH on polarization behavior of stainless steel were studied. In this measurement Ag/AgCl reference electrode and platinum counter electrode were used in a static autoclave lined with inconel. Passive films formed in various conditions were analysed by electron diffraction and Auger spectroscopy. Results obtained were compared with anodic behavior of iron, chromium and nickel and with thermodynamical stabilities of their compounds. The main results are summarized as follows. (1) Stainless steel shows such electrochemical behavior as active dissolution, passivation and transpassivation in a deaerated neutral solution at 250"0C after fully reductive treatment of the specimen. In air-saturated solution, the peak of active dissolution is not ...

1981-01-01

191

Development of high power negative ion sources for fusion at JAERI  

Energy Technology Data Exchange (ETDEWEB)

Technologies producing high power negative ion beams have been highly developed in these years at JAERI for use in neutral beam injectors for heating the thermonuclear fusion plasmas. At present, it is possible to produce multi-ampere H-/D- ion beams quasi-continuously at energies more than a few hundred keV with a good beam optics of beamlet divergence of a few milli-radian. Based on these technologies, two R and D projects have been initiated; one is to develop a 22A/500keV/10s D- ion source for the neutral beam injector for JT-60U, and the other is to develop a 1A/1MeV/60s H- ion source to demonstrate high current negative ion acceleration up to the energy of 1MeV, the energy required for the neutral beam injector for International Thermonuclear Experimental Reactor (ITER). (author).

1995-10-01

192

Comparison of methods to measure the rate of neutral free radical production by photo-deionization of negative ion beams  

Energy Technology Data Exchange (ETDEWEB)

Two measurement methods to determine the rate of neutral free radical production by the photo-deionization of negative ion beams (PDINIB) are introduced. These methods, namely, photoelectron-current measurement by low-frequency electro-modulation probe (PMMP) and measurement of decrease in the negative-ion beam current (DNIC) were employed to evaluate the production rate in a trial surface-processing apparatus developed in the author's laboratory utilizing a steady-flux refined beam of neutral free radicals (RBNR) produced by the PDINIB procedure. A {sup 63}Cu{sup -} negative ion beam of kinetic energy E{sub i} varied up to 15 keV was irradiated with a 514.5 nm visible light beam from a 25 W CW Ar{sup +} ion laser. The detection limit of the production rate by the PMMP setup was as high as 6 x 10{sup 9} s{sup -1} under the condition that E{sub i}=15 keV, the negative-ion beam current I{sub i}=4 {mu}A and the laser power P=6 W. The DNIC ...

2003-05-01

193

Column leaching test to evaluate the use of alkaline industrial wastes to neutralize acid mine tailings  

Energy Technology Data Exchange (ETDEWEB)

Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals that releases highly acidic, sulfate, and metals-rich drainage. In this study, alkaline industrial wastes were mixed with acid mine tailings in order to obtain neutral conditions. A series of column leaching tests were performed to evaluate the behavior of reactive mine tailings amended with alkaline-additions under dynamic conditions. Column tests were conducted of oxidized mine tailings combined with cement kiln dust, red mud bauxite, and mixtures of cement kiln dust with red mud bauxite. The pH results show the addition of 10% of alkaline materials permits the maintenance of near neutral conditions. In the presence of 10% alkaline material, the concentration of toxic metals such as Al, Cu, Fe, Zn are significantly reduced as well as the number of viable cells (Thiobacillus ferrooxidans) compared to control samples.

2005-08-01

194

Additives to neutralize hydrogen sulphide and their application  

Energy Technology Data Exchange (ETDEWEB)

At VNIIKRneft the possibility of using natural ore magnetite as an additive to neutralize hydrogen sulphide in drilling mud is considered. Its activity is sufficiently high and is dependent on the overall iron content and its dispersion. For example, the widely available YuGOK industrial group's magnetite compound, which has an overall content of iron of 66% and specific surface PSH-2 1500 cm/sup 2//g under normal operating conditions, is able to absorb in the first 5 hours 500 l hydrogen sulphide per 1 kg/hour. The activity of the YuGOK compound, which has been ground at the Il'sk weighting material plant to the specific surface of 3000 cm/sup 2//g (PSH-2), is inferior only by 10-15% to the ''sponge''. In addition, structural-mechanical indices of solutions that had been processed with both materials are identical when added in the 10-40% range by volume. At this activation level, to achieve complete ...

1981-01-01

195

High resolution alpha-particle spectroscopy using CR-39 plastic track detector  

Energy Technology Data Exchange (ETDEWEB)

A technique has been developed for high resolution alpha particle spectroscopy from track length determination in CR-39 plastic. On individual tracks an energy resolution deltaE close to the range straggling limit is obtainable. For 6 MeV alpha-particle deltaE is proportional 35 keV on individual particles and for groups of particles deltaE proportional 20 keV can be achieved using certain data selection criteria. At 100 keV on individual particles deltaE is proportional 20 keV. The analysis requires 1) a knowledge of the track-etch rate (Vsub(T))-range relationship and 2) a theoretical understanding of alpha-particle track structure in CR-39 as a function of particle energy, dip angle and degree of etching. The structure of alpha-particle etched tracks in CR-39 is described and two methods of analysis discussed. ...

1984-06-15

196

[Reactive collisions of high-temperature systems]. [Technical progress report 1990  

Energy Technology Data Exchange (ETDEWEB)

The object of this research is to study reactivity at superthermal collision energies using a fast neutral beam that is generated by photodetachment. Systems scheduled for initial study include basic oxygen-hydrogen reactions. Unfortunately, we can not yet report realization of this goal, but during this funding period we have made advances that are anticipated to lead to successful measurements during the next year. The parameters described below refer to the model system O + H{sub 2} {yields} OH + H. The basic design involves the collision of fast neutrals, created by photodetachment of the corresponding negative molecular ion, with a stable reactant gas in a collision cell. Products are detected by ionization and mass analysis. We are equipped to study rotational effects on reactivity by comparing results for rotational levels J = 0 and 1 of H{sub 2}. Highlights during the funding period are given in this report.

1990-12-31

197

Upper bound for a three-photon excitation cross section in atomic argon in the ultraviolet regime  

International Nuclear Information System (INIS)

A scheme of evaluating a generalized three-photon excitation cross section #sigma#/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p"6 "1S_0 state to the 3p"54s'[1/2]_1"0 state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of #DELTA##lambda#/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is #sigma#/sub (3)/ = 1.414 x 10/sup -80/ cm"6 s"2. .AE.

8800-01-01

198

Thermal denitration and mineralization of waste constituents  

Energy Technology Data Exchange (ETDEWEB)

In order to produce a quality grout from LLW using hydraulic cements, proper conditioning of the waste is essential for complete cement curing. Several technologies were investigated as options for conditions. Since the LLW is dilute, removal of all, or most, of the water will significantly reduce the final waste volume. Neutralization of the LLW is also desirable since acidic liquids to not allow cement to cure properly. The nitrate compounds are very soluble and easily leached from solid waste forms; therefore, denitration is desirable. Thermal and chemical denitration technologies have the advantages of water removal, neutralization, and denitration. The inclusion of additives during thermal treatment were investigated as a method of forming insoluable waste conditions.

1997-08-01

199

Small and neutral Tc"vO BAT, bisaminoethanethiol (N_2S_2) complexes for developing new brain imaging agents  

International Nuclear Information System (INIS)

Bisaminoethanethiol (BAT) ligands with various gem-dimethyl and amide groups were prepared, and the corresponding neutral Tc-99m complexes were prepared and evaluated for their relative stabilities by ligand-exchange reactions. It was demonstrated that technetium complexes containing gem-dimethyl substituents have higher lipophilicities, whereas those with an amide group possess greater stability, which enhances ligand-exchange reaction. The most interesting observation was that the brain uptake in rats is not determined only by lipophilicity. Apparently, Tc-99m complexes with an amide functional group display lower brain uptakes in rats compared to those without an amide group. The brain uptake was strongly influenced by substituents on the BAT ligand. These factors are critically important and should be taken into consideration when designing Tc-99m-labeled agents for CNS receptor imaging.

1998-02-01

200

Semihard production of neutral pseudoscalar and tensor mesons in photon-photon collisions  

Energy Technology Data Exchange (ETDEWEB)

We investigate the semihard production of neutral pseudoscalar and tensor mesons in high-energy [gamma][gamma] collisions (M=P=[pi][sup 0], [eta], [eta]' or M=T=a[sub 2], f[sub 2], f[sub 2]'). We deal with the exclusive [gamma][gamma][yields]MM' or semi-exclusive [gamma][gamma][yields]MX reactions (X is the hadron jet with not too large mass). The considered transfer momenta are small in comparison with the photon energies and they are large in comparison with the confinement scale. The amplitudes of these processes are determined by the odderon exchange, i.e. three-gluon exchange in the lowest order of perturbative QCD. The cross sections are calculated in this approximation. The possibility of measurements at LEP and at future [gamma][gamma] colliders is discussed. (orig.).

1992-12-21

201

Resonant CP violation in MSSM Higgs production and decay at {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at {gamma}{gamma} colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of {mu}{sup +}{mu}{sup -}, {tau}{sup +}{tau}{sup -}, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan{beta}-bar 5 (30) and large (small) charged Higgs-boson masses.

2005-07-04

202

Resonant CP violation in MSSM Higgs production and decay at #gamma##gamma# colliders  

International Nuclear Information System (INIS)

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at #gamma##gamma# colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of #mu#"+#mu#"-, #tau#"+#tau#"-, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan#beta#-bar 5 (30) and large (small) charged Higgs-boson masses.

2005-07-04

203

Passivity of high corrosion resistant Cu-Al-Sn alloys  

Energy Technology Data Exchange (ETDEWEB)

In a work studying the corrosion and tarnishing properties of a variety of copper alloys, the alloy Cu-A110-Sn5 was found to show an excellent corrosion resistance in neutral solutions, where copper and most conventional Cu alloys are covered by thick nonprotective surface layers. The passive films formed on this alloy were characterized with electrochemical and photoelectrochemical methods. The pH dependence of the passivation and of the photocurrent behavior of the Cu-A110-Sn5 alloy clearly indicates that the passivity of this alloy in neutral solutions is due to a formation of passive film enriched with aluminum oxide. At corrosion potential a strong increase in the corrosion resistance with time is due to a gradual enrichment of the surface with aluminum oxide. This can be seen in the photocurrent spectra which change from cooper-type to aluminum-type with time. At higher applied potentials the formation of an aluminum-type oxide film is ...

1993-10-01

204

Measurement of charged and neutral current {ital e}{sup {minus}}{ital p} deep inelastic scattering cross sections at high {ital Q}{sup 2}  

Energy Technology Data Exchange (ETDEWEB)

Deep inelastic {ital e}{sup {minus}}{ital p} scattering has been studied in both the charged current (CC) and neutral current (NC) reactions at momentum transfers squared {ital Q}{sup 2} above 400GeV{sup 2} using the ZEUS detector at the HERA {ital ep} collider. The CC and NC total cross sections, the NC to CC cross section ratio, and the differential cross sections {ital d}{sigma}/{ital dQ}{sup 2} are presented. From the {ital Q}{sup 2} dependence of the CC cross section, the mass term in the CC propagator is determined to be {ital M}{sub {ital W}}=76{plus_minus}16{plus_minus}13 GeV.

1995-08-07

205

Empirically Consistent Electroweak Radiative Corrections with the Two-Higgs Doublet Model  

CERN Document Server

The electroweak radiative correction, which turned out to be marginal within the standard electroweak model having the minimal Higgs sector in view of the present experimental information, fits well the experiment when the Higgs sector is extended to have two Higgs doublets. We predict the range where the charged and CP odd Higgs boson masses would lie, taking the two CP even neutral Higgs boson masses to be degenerate which makes the analysis in multiparameter space feasible. It is shown that the mass of neutral Higgs doublet boson can arbitrarily be large consistently with the $W$ mass, if the charged Higgs boson is present and it's mass lies in some appropriate ranges.

2008-01-01

206

Effect of treatment time on low temperature plasma nitriding of stainless steel by saddle field neutral fast atom beam source  

International Nuclear Information System (INIS)

Recent research carried out in laboratories showed that Saddle field neutral fast atom beam source is a promising method for nitriding of stainless steel. In the present work, the effect of treatment time on the microstructural and mechanical properties of plasma-nitrided stainless steel sample was investigated by this new method. Plasma nitriding was carried out at 420 deg. C and at a pressure of 0.1 Pa for a time range of 1 to 12 h. SEM-EDX, microhardness tests, optical microscopy and X-ray diffraction (XRD) were used to evaluate the mechanical and structural properties of the nitrided layer. It was found that nitriding time has a pronounced effect on the structural and mechanical properties of low-temperature plasma-nitrided samples and produced a precipitation-free thin hard nitrided layer within a short processing time.

2006-09-25

207

Direct energy recovery with ac electric power output  

Energy Technology Data Exchange (ETDEWEB)

A concept of direct energy recovery system applying an alternating or rotating magnetic field is proposed for a negative-ion-based neutral beam injection system (NNB) to heat a plasma and/or drive a plasma current in a fusion reactor. Nearly same amounts of residual positive and negative hydrogen-isotope ion beams with beam energy of {approx}1 MeV are produced in an NNB using a gas neutralizing cell. Consequently, a recovered energy is obtained directly in the form of ac electric power, if these positive- and negative-ion beams are alternated or rotated and introduced to two or more recovery electrodes in turn by an alternating or rotating magnetic field. This concept will greatly reduce a technological difficulty in regeneration of a recovered electric energy with such a very high voltage. (author).

1994-12-31

208

Cooling device for impurity removal device in thermonuclear devices  

International Nuclear Information System (INIS)

Purpose: To prevent structure material meltdown upon rupture of cooling pipeways in a impurity remover by preventing the coolants from flowing into the vacuum vessel while continuing the supply of coolants to other portions to be cooled. Constitution: Dual cooling pipeway systems are disposed to the neutralizing plates of the impurity remover. A rupture detector (pressure gage) is mounted to each of the cooling pipeways and flow rate control valves to be opened and closed by the signal from the detector are disposed to the upstream and downstream of the cooling pipeway. In this constitution if the cooling pipes should be ruptured, the coolant supply is stopped to the ruptured system in which the flow rate valve is closed by the signal from the rupture detector. However, since the coolant is kept to be supplied to the other system of the cooling pipeways, meltdown of the neutralizing plates can be prevented. (Kamimura, M.).

1983-08-26

209

Consensus sequence L/PKSSLL mimics crucial epitope on Loop III of Taiwan cobra cardiotoxin  

British Library Electronic Table of Contents (United Kingdom)

Phage display is effective in screening peptides that mimic venom's neutralizing epitopes. A phage display cyclized heptapeptide library (C7C library) was panned with purified divalent antivenin IgG, which neutralizes Naja naja atra venom (NAV) and Bungarus multicinctus venom (BMV). The selected heptapeptide sequences were aligned with known protein sequences of NAV and BMV in GenBank. One of the four consensus sequences, L/PKSSLL, mimicked the crucial epitope on Loop III of Taiwan cobra cardiotoxin that is associated with the venom's lethal potency. In dot blot analysis, several clones showed varying reactivities for NAV monovalent antivenin and lesser cross-reactions with BMV monovalent antivenin. The KSSLLRN-carrying phage occurred four times in selected clones and showed the strongest ...

2009-01-01

210

Analysis by high-performance liquid chromatography of radioactively labeled carbohydrate components of proteoglycans  

Energy Technology Data Exchange (ETDEWEB)

Methods were developed for the separation of radioactively labeled carbohydrate components of proteoglycans by isocratic ion-moderated partition HPLC. Neutral sugars were separated after hydrolysis in trifluoroacetic acid with baseline separation between glucose, xylose, galactose, fucose, and mannose. N-Acetylneuraminic acid, N-acetylated hexosamines, glucose, galactose, and xylitol were likewise well separated from each other under isocratic elution conditions. Glucuronic acid, iduronic acid, and their lactones were separated after hydrolysis in formic acid and sulfuric acid. Glucosamine, galactosamine, galactosaminitol, and glucosaminitol were separated by HPLC on a cation exchanger with neutral buffer after hydrolysis in hydrochloric acid. THe separation techniques also proved useful in fractionation of exoglycosidase digests of O- and N-linked oligosaccharides. Separations of aldoses, hexosamines, and uronic acids were adapted to sensitive ...

1986-04-01

211

A field study of thermal comfort in outdoor and semi-outdoor environments in subtropical Sydney Australia  

Energy Technology Data Exchange (ETDEWEB)

In the absence of empirical outdoor thermal comfort studies it has been widely assumed that indoor thermal comfort theory generalises to outdoor settings without modification. Many indoor models were developed to describe thermal discomfort, not stress, therefore their relevance to conditions that vary greatly from neutrality, as many outdoor climatic conditions do, has not been critically validated in the field to date. The thermal comfort of 1018 subjects in outdoor and semi-outdoor locations in subtropical Sydney was investigated by a questionnaire and a comprehensive package of micro-meteorological instruments. The thermal neutrality in terms of the thermal comfort index OUT{sub S}ET* of 26.2 {sup o}C was significantly higher than the indoor SET* counterpart of 24{sup o}C (ASHRAE Trans. 92 (1986) 709). (author)

2003-05-01

212

Test of superconducting Nb/Al bilayers as particle detectors  

Energy Technology Data Exchange (ETDEWEB)

Superconducting thin film particle detectors can be very attractive due to the low sensitivity to radiation damage. We describe the fabrication procedure and the characterization of Nb/Al bilayers as particle detectors. First steady and dynamical results are reported from tests of 5 MeV alpha-particle detection.

2000-04-07

213

Tachyons: may they have a role in elementary particle physics  

International Nuclear Information System (INIS)

The possible role of space-like objects in elementary particle physics (and in quantum mechanics) is reviewed and discussed, mainly by exploiting the explicit consequences of the peculiar relativistic mechanics of Tachyons. Particular attention is paid: (i) to tachyons as the possible carriers of interactions; (ii) to the possibility of ''vacuum decays'' at the classical level; (iii) to a Lorentz-invariant bootstrap model; (iv) to the apparent shape of the tachyonic elementary particles and its possible connection with the de Broglie wave-particle dualism. (author).

217
219

Higher harmonics of spontaneous radiation of ultrarelativistic channeled particles  

International Nuclear Information System (INIS)

The case of spontaneous radiation of channeled ultrarelativistic particles is considered when the dipolarity condition is not satisfied. The change of the particle longitudinal velocity affecting the maximum radiation frequency is included. The angular and frequency characteristics of the radiation for superhigh energies are studied for the first time. It is shown that there is an optimum energy at which the radiation density is maximum. The influence of the angle at which electrons enter a crystal and of the beam divergence on the radiation is investigated. The problem of quasichanneled particle radiation and also the radiation in axis-plane transitions are considered. (author).

1980-06-01

220

Handling boundary constraints for numerical optimization by particle swarm flying in periodic search space  

CERN Document Server

The periodic mode is analyzed together with two conventional boundary handling modes for particle swarm. By providing an infinite space that comprises periodic copies of original search space, it avoids possible disorganizing of particle swarm that is induced by the undesired mutations at the boundary. The results on benchmark functions show that particle swarm with periodic mode is capable of improving the search performance significantly, by compared with that of conventional modes and other algorithms.

2005-01-01

221

Grassmann-odd Nambu bracket on Grassmann algebra  

International Nuclear Information System (INIS)

... Ukraine) INIS-UA--107 211 p. PHYSICS OF ELEMENTARY PARTICLES AND

2006-09-19

225

Fibrous Carbon  

Science.gov (United States)

... was noted. It was reported that similar fibers also grew on particles of thermal carbon black at a temperature of 10500 and in an atmosphere ...

1963-05-10

226

Electromagnetic properties of generalized Majorana particles  

Energy Technology Data Exchange (ETDEWEB)

We prove a theorem stating that a massive Majorana particle (a CPT-self-conjugate particle) with arbitrary spin J can possess only an anapole moment and multipoles of that. We also show that massless Majorana particles, except those of spin (1/2, do not have any single-photon electromagnetic form factor.

1989-02-20

230

Concept of Plasma Spraying System for Solid Oxide Fuel Cell: Heating Studies of YSZ Particle in Plasma Jet  

International Nuclear Information System (INIS)

One of several methods to build YSZ electrolyte of SOFC is plasma spraying. This system heats particle to a melting point and then pushing them into target and forming a deposition. This paper presents heating studies of YSZ particle in plasma jet. By simple model it is shown that the required time such those YSZ particle with grain size of 50 ?m to be melt is around 12 x 10-4 second. (author)

2006-07-01

231

Climate Change: The Role of Particles and Gases  

ScienceCinema

...global warming ...the effects of global warming ...also the ? that global warming ...

233

Bragg curve spectroscopy detector for particle identification  

International Nuclear Information System (INIS)

The operation principle, construction and characteristics of the Bragg curve spectroscopy detector (BCS detector) are described. The electric field of the BCS detector is parallel to the particle trajectories. The detector was tested by 8.78 MeV and 6.02 MeV #alpha# particles from a ThC-ThC's source. The energy resolutions are 1.5% and 2.6% respectively for two groups of #alpha# particles, and the charge resolution is 2.7%. Further test experiments with heavy ions will be arranged.

234

Application of alpha-particle spectrometry in post-irradiation research and reprocessing  

Energy Technology Data Exchange (ETDEWEB)

Current applications of ..cap alpha..-particle spectrometry in post-irradiation research and reprocessing are reviewed. Implementation of procedures and techniques described in the literature to the particular samples at S.C.K./C.E.N. often results in a combined radiochemical method where ..cap alpha..-particle spectrometry is used to complement or enforce results obtained by other methods. Typical cases are reported and results obtained by different methods are compared to the results obtained by ..cap alpha..-particle spectrometry.

1984-04-01

235

A Leptonic-Hadronic Model for the Afterglow of Gamma-Ray ...  

Science.gov (United States)

... PHYSICS ATOMIC AND MOLECULAR PHYSICS AND SPECTROSCOPY NUCLEAR PHYSICS & ELEMENTARY PARTICLE PHYSICS. ...

2010-11-20

236

Non-linearity and hysteresis of Hall effect in magnetorheological suspensions with conducting carrier  

Energy Technology Data Exchange (ETDEWEB)

In this article a production method of a magnetorheological suspension composed with silicon steel particles of size 0.1-0.15 mm and 4% silicon content is described. Steel particles were dispersed in a conducting carrier of a by mixture of graphite particles with size 2-5 {mu}m and cedar wood oil. The filling factor of the suspension with the silicon steel particles and with graphite particles amounted to 0.25-0.40. Samples of this suspension were placed in a rectangular vessel with electrodes and used for the investigation of the Hall effect in magnetic field with induction 0-8 T, generated by Bitter-type magnet. A non-linear dependence of Hall voltage on the induction of the applied magnetic field and a hysteresis loop of this voltage in the shape of inclined digit eight were found. The causes of the observed effects is the ordering of silicon steel particles ...

2003-08-01

237

Magnetospheric particle acceleration and X-ray emission of pulsars  

CERN Document Server

The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the surface of neutron star and trigger the acceleration of particles. The charged particles are accelerated mainly in the field of magneto-dipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magneto-dipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.

2007-01-01

238

Comparative study of three dimensional numerical simulations of particle dispersion in a turbulent air flow  

International Nuclear Information System (INIS)

This paper describes the study of particles' dispersion in an isotropic turbulent flow. The particle's motion and the turbulent flow characteristics are calculated independently. While the particles' displacement is computed by the author's code, the flow is simulated with a commercial code : PowerFLOW. The particles and the flow are coupled through the relative velocity component of the aerodynamic force. When the simulated flow is turbulent, a turbulence regeneration model is used in order to get the flow instantaneous velocity. Validation of the method is done by comparing the particles' dispersion obtained with experimental results from literature and with the results calculated by FLUENT. Good accordance is found between numerical studies and experimental results. However, comparison between results of PowerFLOW coupled to the author's code and results from FLUENT shows ...

2004-05-09

239

Acceleration of particles in pulsar magnetosphere and the X-ray radiation  

CERN Document Server

The available data of single X-ray pulsars, their wind nebulae, and the SNRs which are connected to some of these sources are analysed. It is shown that electric field intensity of neutron stars tears off charged particles from the surface of neutron star and triggers the acceleration of particles. The charged particles are accelerated mainly in the field of magnetodipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magnetodipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.

2004-01-01

240

Radiative transfer in a solar absorbing particle laden flow  

Science.gov (United States)

A possible receiver configuration is a cavity in which a falling sheet of solid particles is directly irradiated by the concentrated solar flux passing through the aperture. Regardless of the particular geometry, the radiative transfer within the falling particle curtain must be studied in order to determine the net radiative heating rate for the particles. A discrete ordinate radiative transfer model has been developed to predict the radiative coupling within the falling particle curtain. The model determines how much energy is absorbed by the particles, how much is transmitted to the rear wall of the receiver, and determines the effects of particle scattering and thermal emission on the net radiation absorbed by the particles. The model accounts for the directional nature of the radiation field, particle scattering, ...

1985-11-01

241

Quantum Secure Direct Communication with Four-Particle Genuine Entangled State and Dense Coding  

Science.gov (United States)

A quantum secure direct communication scheme using dense coding is proposed. At first, the sender (Alice) prepares four-particle genuine entangled states and shares them with the receiver (Bob) by sending two particles in each entangled state to him. Secondly, Alice encodes secret information by performing the unitary transformations on her particles and transmits them to Bob. Finally, Bob performs the joint measurements on his particles to decode the secret information. The two-step security test guarantees the security of communication.

2009-07-01

242

Numerical prediction of flow field and particle trajectory in a hard disk drive  

Energy Technology Data Exchange (ETDEWEB)

A flow field and particle trajectory in a HDD (Hard Disk Drive) between two rotating disks in axisymmetric enclosures is investigated using CFD code FLUENT/UNS. The RNG k-{epsilon} model is used as a turbulent model. In this study, the flow field between two disks are symmetric, and the flow field near the enclosure is very complex. Cross stream vectors are shown both for blowing and no blowing from the hub. The larger a particle, the more fast the particle deposits at the walls. In the case of blowing from the hub, the more fast the particle deposits at the walls. (author). 9 refs., 12 figs., 1 tab.

1999-11-01

243

Multigroup transfer matrices for charged-particle and neutron-induced reactions Part III: Energy conservation and local deposition  

Energy Technology Data Exchange (ETDEWEB)

Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.

1983-11-01

244

Multigroup transfer matrices for charged-particle and neutron-induced reactions Part III: Energy conservation and local deposition  

International Nuclear Information System (INIS)

Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.

1983-01-01

245

Method for production of uranium dioxide particles from uranium hexafluoride by growing process in fluidized bed  

International Nuclear Information System (INIS)

Processes of production and purification (necessary for fabricating fuel elements) of powdery uranium dioxide with particle size up to 1000 #mu#m and more have been studied. Developed is continuous process of UO_2 production with above particle size by converting uranium hexafloride into UO_2 solid particles in fluidized bed while their interaction with water vapor and hydrogen on the uranium dioxide nucleus material. The method allows to conduct continuous selection from the apparatus of UO_2 powder fraction with particle size near 1000 #mu#m without nucleus material additional feed.

246

In-place testing of HEPA filter systems by the single-particle, particle-size spectrometer method  

Energy Technology Data Exchange (ETDEWEB)

This standard describes the procedure and equipment for in-place testing of HEPA filter systems by the single-particle, particle-size (SPPS) spectrometer method. This method provides the capability for evaluating the effectiveness (i.e., decontamination factor or DF) of systems consisting of one or more stages of HEPA filters against submicrometer aerosols in discrete particle-size ranges. It is particularly useful for testing of multi-stage HEPA filter installations and for testing of very large (50,000 cfm installed capacity) single-stage systems where it is desired to minimize the quantity of challenge aerosol required.

1981-12-01

247

Development of thin foil Faraday collector as a lost alpha particle diagnostic for high yield D-T tokamak fusion plasmas  

Energy Technology Data Exchange (ETDEWEB)

Alpha particle confinement is necessary for ignition of a D-T tokamak fusion plasma and for first wall protection. Due to high radiation backgrounds and temperatures, scintillators and semiconductor detectors may not be used to study alpha particles which are lost to the first wall during the D-T programs on JET and ITER. An alternative method of charged particle spectrometry capable of operation in these harsh environments, is proposed: it consists of thin foils of electrically isolated conductors with the flux of alpha particles determined by the positive current flowing from the foils. 2 refs., 3 figs.

1994-07-01

248

Compound nucleus contribution to the alpha particle scattering from "2"8Si  

International Nuclear Information System (INIS)

In the case of inelastic scattering of alpha particles to the 3"+ state, the averaged angular distributions show a characteristic shape, corresponding to the excitation of such an unnatural parity state by alpha particles in the compound nucleus process. The modified Hauser-Feshbach cross-section calculations give a good description of the averaged distributions for the alpha particle scattering to the 3"+ state and the compound nucleus parameters could be extracted. The calculations of the compounds nucleus contributions to the other states in the case of 24 MeV alpha particle scattering from "2"8Si show that this contribution is not negligible and in the case of the scattering to the 4"+ state seems to be dominant. (Z.M.).

249

Transport and superconducting properties of RNi_2B_2C (R=Y, Lu) single crystals  

International Nuclear Information System (INIS)

The in-plane resistivity, in-plane absolute thermopower, and upper critical field measurements are reported for single-crystal samples of YNi_2B_2C and LuNi_2B_2C superconductors. The in-plane resistivity shows metallic behavior and varies approximately linearly with temperature near room temperature (RT) but shows nearly quadratic behavior in temperature at low temperatures. The YNi_2B_2C and LuNi_2B_2C single-crystal samples exhibit large transverse magnetoresistance (#approx#6 8% at 45 kOe) in the ab plane. The absolute thermopower S(T) is negative from RT to the superconducting transition temperature T_c. Its magnitude at RT is a few times of the value for a typical good metal. S(T) is approximately linear in temperature between #approx#150 K and RT. Extrapolation to T=0 gives large intercepts (few #mu#V/K) for both samples suggesting the presence of a much larger knee than would be expected from electron-phonon interaction renormalization effects. The upper critical fields for H ...

250

Sequences, geographic variations and molecular phylogeny of venom phospholipases and threefinger toxins of eastern India Bungarus fasciatus and kinetic analyses of its Pro31 phospholipases A2.  

Science.gov (United States)

Eight phospholipases A2 (PLAs) and four three-finger-toxins (3FTx) from the pooled venom of Bungarus fasciatus (Bf) were previously studied and sequenced, but their expression pattern in individual Bf venom and possible geographic variations remained to be investigated. We herein analyze the individual venom of two Bf specimens from Kolkata (designated as KBf) to address this question. Seven PLAs and five 3FTx were purified from the KBf venoms, and respective cDNAs were cloned from venom glands of one of the snakes. Comparison of their mass and N-terminal sequence revealed that all the PLAs were conserved in both KBf venoms, but that two of their 3FTx isoforms were variable. When comparing the sequences of these KBf-PLAs with those published, only one was found to be identical to that of Bf Vb-2, and the other five were 94-98% identical to those of Bf II, III, Va, VI and XI-2, respectively. Notably, the most abundant PLA isoforms of Bf and KBf venoms contain Pro31 ...

2006-12-08

251

Environmentally assisted cracking in light water reactors. Semiannual report, October 1993--March 1994. Volume 18  

International Nuclear Information System (INIS)

This report summarizes work performed by Argonne National Laboratory (ANL) on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) during the six months from October 1993 to March 1994. EAC and fatigue of piping, pressure vessels, and core components in LWRs are important concerns in operating plants and as extended reactor lifetimes are envisaged. Topics that have been investigated include (a) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels, (b) EAC of wrought and cast austenitic stainless steels (SSs), and (c) radiation-induced segregation and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS after accumulation of relatively high fluence. Fatigue tests have been conducted on A302-Gr B low-alloy steel to verify whether the current predictions of modest decreases of fatigue life in simulated pressurized water reactor water are valid for high-sulfur heats that show environmentally enhanced ...

2007-09-01

252

Electromagnetic structure of decuplet baryons towards the chiral regime  

Science.gov (United States)

The electromagnetic properties of the baryon decuplet are calculated in quenched QCD on a 20{sup 3}x40 lattice with a lattice spacing of 0.128 fm using the fat-link irrelevant clover fermion action with quark masses providing a pion mass as low as 300 MeV. Magnetic moments and charge radii are extracted from the electric and magnetic form factors for each individual quark sector. From these, the corresponding baryon properties are constructed. We present results for the higher-order moments of the spin-3/2 baryons, including the electric-quadrupole moment E2 and the magnetic-octupole moment M3. The world's first determination of a nonzero M3 form factor for the {delta} baryon is presented. With these results we provide a conclusive analysis which shows that decuplet baryons are deformed. We compare the decuplet-baryon results from a similar lattice calculation of the octet baryons. We establish that the environment sensitivity is far less pronounced for the decuplet baryons ...

2009-09-01

253

Working group report on electron-impact processes: Recommended database for electron impact excitation and ionization  

International Nuclear Information System (INIS)

The cross section database for electron impact excitation and electron impact ionization for hydrogen beam kinetic energies greater than 100 eV was considered, giving for each particular process a reference to a recommended publication of cross sections, as well as the accuracy or estimated accuracy. The work is motivated by the application of neutral beam injection in magnetic confinement devices, such as large tokamaks. 9 refs, 2 figs.

1989-07-01

254

Thermogalvanic effects on the pitting corrosion of water-cooled heat exchangers  

Energy Technology Data Exchange (ETDEWEB)

Thermogalvanic corrosion of St3 steel in a temperature range from 25 to 50{degrees}C with a 3.84{degrees}C/cm gradient was studied in a neutral media flow. It is shown that the thermogalvanic effect on the pitting corrosion of water-cooled heat exchangers is decisive but dual. Depending on the composition of the cooling medium, thermogalvanic corrosion may either enhance (0.5 M NaCl) or inhibit (tap water) pitting corrosion.

1995-05-01

255

The poly dA helix: a new structural motif for high performance DNA-based molecular switches  

UK PubMed Central (United Kingdom)

We report a pH-dependent conformational transition in short, defined homopolymeric deoxyadenosines (dA15) from a single helical structure with stacked nucleobases at neutral pH to a double-helical,...Full Text Available

2009-05-01

256

The deep-inelastic neutrino (anti)-nucleus scattering with Photon polarization  

International Nuclear Information System (INIS)

By using the quark-parton-flucton and Weinberg-Salam models, effects of interactions of weak neutral quark and neutrino currents were considered in deep - inelastic neutrino (anti)-nucleus scattering #nu# (anti-#nu#) A #-># #nu# (anti-#nu#) #gamma#X. The energy spectrum and degree of photon circular polarization were obtained in present paper. In particular for the nucleon (A = 1). The theoretical results were in a good agreement with data mentioned. (author). 6 refs., 4 figs.

257

Synergetic extraction in systems with dicarbollide and bidentate phosphonate  

Energy Technology Data Exchange (ETDEWEB)

A process for the extraction of tervalent metal cations from 3 M HNO[sub 3] highly radioactive waste based on synergetic mixtures of dicarbollide with neutral organophosphonate (dibutyl diethylcarbamoylmethylene phosphonate) is proposed. Due to the great hydrophobicity of dicarbollide anion, the species ML[sub n[sup 3+

1994-01-01

258

Supersymmetry. Present status and prospects  

Energy Technology Data Exchange (ETDEWEB)

Starting from the gauge hierarchy problem as a motivation, supersymmetric theories are reviewed. The minimal supersymmetric standard model is briefly described and the possible soft breaking terms of supersymmetry are introduced. Phenomenological questions are addressed for the flavor changing neutral current and CP violation. Phenomenological evidences for the supersymmetric grand unified models are reviewed and proton decay is examined. Relations with supergravity and superstring unification is also mentioned. (author).

1995-05-01

259

Summary and closing remarks  

Energy Technology Data Exchange (ETDEWEB)

A summary of the topics covered in papers presented at the 1995 Brookhaven joint conference on production, neutralization, and application of negative ion beams is given. The conference topics covered included plasma ion sources, plasma seeding of these sources for increased ion production, beam extraction and transport, computer simulation and design studies, and operation of existing and experimental ion source facilities. Application of the sources to accelerator, tokamak, and thin film deposition are discussed. (AIP) {copyright} {ital 1996 American Institute of Physics.}

1996-07-01

260

Stress corrosion cracking susceptibility of alloy 800  

Energy Technology Data Exchange (ETDEWEB)

Steam generators (SGs) in PWRs and CANDUs are designed for at least a 30-year operating life. However, in the 15-25 years that SGs tubed with Alloy 600 have operated commercially, they have experienced reduced reliability, mainly due to SG tubing degradation. One of the degradation mechanisms that Alloy 600 SG tubing has suffered from is lead-induced stress corrosion cracking (PbSCC) in AVT and near-neutral SG environments. In contrast to Alloy 600 tubing, test data obtained in high temperature water indicate that Alloy 800 is resistant to cracking by lead and lead compounds. For Alloy 800 (cold worked, shot peened), the most aggressive environment is reported to be alkaline with minor concentration of PbO (80 ppm). Work by Max Helie et al. also concluded that Alloy 800 is not sensitive to lead assisted SCC for pH values close to neutrality, whereas it could be affected in high alkaline conditions. The work reported here investigated the ...

2002-07-01

261

Stress corrosion cracking susceptibility of alloy 800  

International Nuclear Information System (INIS)

Steam generators (SGs) in PWRs and CANDUs are designed for at least a 30-year operating life. However, in the 15-25 years that SGs tubed with Alloy 600 have operated commercially, they have experienced reduced reliability, mainly due to SG tubing degradation. One of the degradation mechanisms that Alloy 600 SG tubing has suffered from is lead-induced stress corrosion cracking (PbSCC) in AVT and near-neutral SG environments. In contrast to Alloy 600 tubing, test data obtained in high temperature water indicate that Alloy 800 is resistant to cracking by lead and lead compounds. For Alloy 800 (cold worked, shot peened), the most aggressive environment is reported to be alkaline with minor concentration of PbO (80 ppm). Work by Max Helie et al. also concluded that Alloy 800 is not sensitive to lead assisted SCC for pH values close to neutrality, whereas it could be affected in high alkaline conditions. The work reported here investigated the ...

2002-05-05

262

Semihard production of tensor mesons in #gamma##gamma#-collisions and the perturbative Odderon  

International Nuclear Information System (INIS)

The cross sections of neutral tensor mesons T=a_2, f, f', ... production in the exclusive #gamma##gamma##->#TT' or semiexclusive #gamma##gamma##->#TX processes (three gluon exchange) in the semihard region s>>vertical stroketvertical stroke>1 GeV"2 are calculated. The relation of investigated processes to the problem of perturbative Odderon is discussed. The possibility of measurements at LEP and at a future #gamma##gamma#-colliders is discussed too. (orig.).

263

Quasiparticle transport equation with collision delay. I. Phenomenological approach  

International Nuclear Information System (INIS)

For a system of noninteracting electrons scattered by resonant levels of neutral impurities, we show that virial and quasiparticle corrections have nearly equal magnitudes. We propose a modification of the Boltzmann equation that includes quasiparticle and virial corrections and discuss their interplay on a dielectric function. copyright 1997 The American Physical Society.

264

Oxygen-induced enhancement of the adsorptive capacity of activated charcoal  

Energy Technology Data Exchange (ETDEWEB)

Adsorption isotherms for phenol and o-cresol on activated charcoal at neutral pH and several dissolved oxygen concentrations were conducted at 23{degree}C. Significant improvements in capacities were observed with increasing dissolved oxygen concentrations for the two adsorbates. These statistically-significant additional capacities were not due to biological activities but merely due to surface chemical reactions. The improvement in capacity was directly related to the amount of oxygen per unit mass of GAC.

1992-02-01

265

Oxidative stability of biodiesel from soybean oil fatty acid ethyl esters; Estabilidade oxidativa de biodiesel de esteres etilicos de acidos graxos de soja  

Energy Technology Data Exchange (ETDEWEB)

Biodiesel consists of long-chain fatty acid esters, derived from renewable sources such as vegetable oils, and its utilization is associated to the substitution of the diesel oil in engines. Depending on the raw material, bio diesel can contain more or less unsaturated fatty acids in its composition, which are susceptible to oxidation reactions accelerated by exposition to oxygen and high temperatures, being able to change into polymerized compounds. The objective of this work was to determine the oxidative stability of bio diesel produced by ethanolysis of neutralized, refined, soybean frying oil waste, and partially hydrogenated soybean frying oil waste. The evaluation was conducted by means of the Rancimat equipment, at temperatures of 100 and 105 deg C, with an air flow of 20 L h{sup -1}. The fatty acid composition was determined by GC and the iodine value was calculated. It was observed that even though the neutralized, refined and waste ...

2005-06-01

266

Neutron-proton mass difference in isospin-asymmetric nuclear matter  

Energy Technology Data Exchange (ETDEWEB)

Isospin-breaking effects in the baryonic sector are studied in the framework of a medium-modified Skyrme model. The neutron-proton mass difference in infinite, asymmetric nuclear matter is discussed. In order to describe the influence of the nuclear environment on the skyrmions, we include energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it strongly decreases in neutron matter. (orig.)

2007-06-15

267

Negative ion formation in magnetically insulated transmission lines  

Energy Technology Data Exchange (ETDEWEB)

Negative ion intensities of over 3 x 10/sup 5/ A/m/sup 2/ at energies of 2 MeV have been measured in a magnetically insulated transmission line. This negative ion production can affect the power flow in multiterawatt pulsed power devices, and may also have applications in the generation of high-intensity neutral or negative ion beams.

1982-05-01

268

Nature Of Tube Degradation In Horizontal Steam Generators  

Energy Technology Data Exchange (ETDEWEB)

Nature of tube degradation was studied in support of horizontal steam generator lifetime calculations. Experiments were carried out to evaluate the resistance to environmentally assisted cracking (EAC) of steam generator tubes during operation. Estimations of the incubation period for crack initiation and the threshold K value, K(ISCC), and the crack growth rate were made to predict evolution of damage in tube walls. Experimental results were compared with in-service inspections experience. The paper summarizes results of experiments of C ring specimen for the initiation testing and results of SENT (single edge notch tensile) specimen for the crack growth rate (CGR) testing. The specimens were exposed to concentrated environments at elevated temperatures simulating crevice environments in secondary side crevices in horizontal steam generators. The results show that material of SG (steam generator) tubes is sensitive to transgranular environmentally assisted cracking in the three basic ...

2002-07-01

269

Nature Of Tube Degradation In Horizontal Steam Generators  

International Nuclear Information System (INIS)

Nature of tube degradation was studied in support of horizontal steam generator lifetime calculations. Experiments were carried out to evaluate the resistance to environmentally assisted cracking (EAC) of steam generator tubes during operation. Estimations of the incubation period for crack initiation and the threshold K value, K(ISCC), and the crack growth rate were made to predict evolution of damage in tube walls. Experimental results were compared with in-service inspections experience. The paper summarizes results of experiments of C ring specimen for the initiation testing and results of SENT (single edge notch tensile) specimen for the crack growth rate (CGR) testing. The specimens were exposed to concentrated environments at elevated temperatures simulating crevice environments in secondary side crevices in horizontal steam generators. The results show that material of SG (steam generator) tubes is sensitive to transgranular environmentally assisted cracking in the three basic ...

2002-09-23

270

Lipophilic technetium complexes. Technetium chelates of some O, N, S donor Schiff bases  

Energy Technology Data Exchange (ETDEWEB)

Dianionic tridentate, O, N, S, Schiff bases derived from salicylaldehyde and 2-mercapto-amines react with Tc(V) gluconate to form radiochemically pure neutral Tc chelates. The existence of lipophilic Tc complexes could be proved by high voltage electrophoresis, thin layer chromatography and octanol/water partition coefficients. 11 refs.

1984-04-02

271

Lipophilic technetium complexes. Technetium chelates of some O, N, S donor Schiff bases  

International Nuclear Information System (INIS)

Dianionic tridentate, O, N, S Schiff bases derived from salicylaldehyde and 2-mercapto-amines react with Tc(V) gluconate to form radiochemically pure neutral Tc chelates. The existence of lipophilic Tc complexes could be proved by high voltage electrophoresis, thin layer chromatography and octanol/water partition coefficients. (author).

1984-04-01

272

Iodine-123-labeled pH shift brain-imaging agents  

International Nuclear Information System (INIS)

HIPDM is an "1"2"3I-labeled agent with a distribution in brain reflecting regional perfusion. This compound is neutral and lipid soluble at blood pH and freely crosses the blood-brain barrier. At the lower pH in brain, it picks up a hydrogen ion and becomes positively charged. In this form the molecule is not lipid soluble and it is trapped in brain.

1982-05-03

273

Implications of biodiversity of short rotation coppice  

Environmental Research Database

DescriptionFossil fuels have a detrimental effect on the environment. They lead to the increase in atmospheric carbon dioxide which has been documented over the last 150 years. In contrast, some sources of renewable energy are near carbon neutral. Renewable energy produced from biomass constitutes such a type of energy and so has many potential advantages. The Energy White Paper (DTI et al., 2003) identifies bioenergy as an important means of meeting the Government's energy and environment objectives, in [continued...

2009-01-31

274

Immunological correlates for protection against intranasal challenge of Bacillus anthracis spores conferred by a protective antigen-based vaccine in rabbits.  

Science.gov (United States)

Correlates between immunological parameters and protection against Bacillus anthracis infection in animals vaccinated with protective antigen (PA)-based vaccines could provide surrogate markers to evaluate the putative protective efficiency of immunization in humans. In previous studies we demonstrated that neutralizing antibody levels serve as correlates for protection in guinea pigs (S. Reuveny et al., Infect. Immun. 69:2888-2893, 2001; H. Marcus et al., Infect. Immun. 72:3471-3477, 2004). In this study we evaluated similar correlates for protection by active and passive immunization of New Zealand White rabbits. Full immunization and partial immunization were achieved by single and multiple injections of standard and diluted doses of a PA-based vaccine. Passive immunization was carried out by injection of immune sera from rabbits vaccinated with PA-based vaccine prior to challenge with B. anthracis spores. Immunized rabbits were challenged by intranasal spore ...

2006-01-01

275

Fusion technology  

International Nuclear Information System (INIS)

The Fusion Technology task performs analyses and systems studies of conceptual fusion reactors based upon inertial and high-#beta# magnetic confinement schemes. Progress in the areas of theoretical analysis (plasma and neutral-gas blanket models), specific reactor studies (toroidal and linear theta pinches, Z pinches, laser fusion) neutronic and nuclear data assessments, materials (metals and insulators) evaluation, and general engineering design is reported.

1976-12-01

276

Further development of the RTFE technique for the comprehensive management of liquid radioactive wastes from Russian NPP in Comecon countries. Final report; Weiterentwicklung der RDA-Technologie fuer die umfassende Entsorgung von in den RGW-Laendern anfallenden radioaktiven Fluessigkeiten aus KKW sowjetischen Typs. Schlussbericht  

Energy Technology Data Exchange (ETDEWEB)

The composition of alkaline and neutral boric acid containing evaporator concentrates resulting from the treatment of radioactive waste water in nuclear power plants with WWER reactors is described as well as the processing of these concentrates to a product suitable for final disposal. Tests with mock solutions of these evaporator concentrates have been performed at the laboratory and teststand scale to produce a dry residue by continuous thickening, which can be processed into a highly leach resistant product, suitable for final disposal, by cementation. Ca-compounds must be added to the evaporator concentrates prior to the drying in an rotary thin-film evaporator (RTFE). The tests showed that neutral evaporator concentrates can be dried in a RTFE with addition of small amounts of Ca-compounds. The alkaline evaporator concentrates with high boric acid and total salt load require a multiple amount of Ca-compounds and diluting water to perform ...

1992-04-01

277

Formation and stability of astatide-mercury complexes  

International Nuclear Information System (INIS)

The formation of astatide-mercury complexes was investigated in aqueous solutions.The obtained complexes were examined by paper electrophoresis. It was found that Hg(OH)At and Hg(OH)I complexes were formed in neutral solution. The stability constants of the obtained complexes were determined by ion-exchange. The preliminary results indicate that the complex of mercury with astatide is much more stable than similar complexes with iodide. (author)

2006-04-01

278

Evaluation of tritium diffusion through the Neutral Beam Injector calorimeter panel  

Energy Technology Data Exchange (ETDEWEB)

The Neutral Beam Test Facility (NBTF) to be realized in Padoa will test the Neutral Beam Injection (NBI), one of the Heating and Current Drive Systems foreseen for ITER. The NBI is based on the acceleration of hydrogen or deuterium negative ions up to 1 MeV. This work has been aimed at assessing the tritium release from the NBTF in order to provide data for the safety analysis. In particular, the diffusion of the tritium through the neutral beam target material (the CuCrZr alloy calorimeter panels) has been assessed by using literature data of the diffusion coefficient. The tritium generated inside the calorimeter panels moves into both the vacuum and water side: the tritium diffusion flux has been evaluated during the beam-on (200 deg. C) and the beam-off (20 deg. C) phases of the NBTF experiments consisting of an interim campaign and a final test. The penetration depth of the tritium through the 2 mm thick CuCrZr alloy ...

2009-06-15

279

Evaluation of tritium diffusion through the Neutral Beam Injector calorimeter panel  

International Nuclear Information System (INIS)

The Neutral Beam Test Facility (NBTF) to be realized in Padoa will test the Neutral Beam Injection (NBI), one of the Heating and Current Drive Systems foreseen for ITER. The NBI is based on the acceleration of hydrogen or deuterium negative ions up to 1 MeV. This work has been aimed at assessing the tritium release from the NBTF in order to provide data for the safety analysis. In particular, the diffusion of the tritium through the neutral beam target material (the CuCrZr alloy calorimeter panels) has been assessed by using literature data of the diffusion coefficient. The tritium generated inside the calorimeter panels moves into both the vacuum and water side: the tritium diffusion flux has been evaluated during the beam-on (200 deg. C) and the beam-off (20 deg. C) phases of the NBTF experiments consisting of an interim campaign and a final test. The penetration depth of the tritium through the 2 mm thick CuCrZr alloy ...

2009-06-01

280

Diffusion in silicon isotope heterostructures  

Science.gov (United States)

The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and {sup 28}Si enriched layers, enables the observation of {sup 30}Si self-diffusion from the natural layers into the {sup 28}Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion ...

2004-05-14

281

Diffusion absorption heat pump. Diffusion-Absorptions-Waermepumpe  

Energy Technology Data Exchange (ETDEWEB)

The development of a gas-operated diffusion absorption heat pump for the heating of living spaces is described. By various improvement an energy efficiency of the prototypes of 1.5 was achieved. Structural alterations led to a lower overall height and lower production costs. The CFCs used in electric heat pumps were replaced by environmentally neutral ammonia. Compared with conventional gas heating systems, the CO2 output could be reduced by more than 30%. figs., tabs.

1992-02-01

282

Differential Specificity and Immunogenicity of Adenovirus Type 5 Neutralizing Antibodies Elicited by Natural Infection or Immunization?  

UK PubMed Central (United Kingdom)

A recent clinical trial of a T-cell-based AIDS vaccine delivered with recombinant adenovirus type 5 (rAd5) vectors showed no efficacy in lowering viral load and was associated with increased risk of...Full Text Available

2010-01-01

283

Corrosion studies of carbon steel under impinging jets of simulated slurries of neutralized current acid waste (NCAW) and neutralized cladding removal waste (NCRW)  

Energy Technology Data Exchange (ETDEWEB)

Plans for the disposal of radioactive liquid and solid wastes presently stored in double-shell tanks at the Hanford Site call for retrieval and processing of the waste to create forms suitable for permanent disposal. Waste will be retrieved from a tank using a submerged slurry pump in conjunction with one or more rotating slurry jet mixer pumps. Pacific Northwest Laboratory (PNL) has conducted tests using simulated waste slurries to assess the effects of a impinging slurry jet on the corrosion rate of the tank wall and floor, an action that could potentially compromise the tank's structural integrity. Corrosion processes were investigated on a laboratory scale with a simulated neutralized cladding removal waste (NCRW) slurry and in a subsequent test with simulated neutralized current acid waste (NCAW) slurry. The test slurries simulated the actual NCRW and NCAW both chemically and physically. The tests simulated those conditions ...

1992-01-01

284

Corrosion studies of carbon steel under impinging jets of simulated slurries of neutralized current acid waste (NCAW) and neutralized cladding removal waste (NCRW)  

Energy Technology Data Exchange (ETDEWEB)

Plans for the disposal of radioactive liquid and solid wastes presently stored in double-shell tanks at the Hanford Site call for retrieval and processing of the waste to create forms suitable for permanent disposal. Waste will be retrieved from a tank using a submerged slurry pump in conjunction with one or more rotating slurry jet mixer pumps. Pacific Northwest Laboratory (PNL) has conducted tests using simulated waste slurries to assess the effects of a impinging slurry jet on the corrosion rate of the tank wall and floor, an action that could potentially compromise the tank`s structural integrity. Corrosion processes were investigated on a laboratory scale with a simulated neutralized cladding removal waste (NCRW) slurry and in a subsequent test with simulated neutralized current acid waste (NCAW) slurry. The test slurries simulated the actual NCRW and NCAW both chemically and physically. The tests simulated those conditions expected to ...

1992-01-01

285

Charge exchange processes in low-energy He sup + ion scattering from Si and Pd sub 2 Si surfaces  

Energy Technology Data Exchange (ETDEWEB)

The surface of Si and thin layers of Pd{sub 2}Si on Si have been studied by low-energy He{sup +} ion scattering. The occurrence of the observed low-energy tails is attributed to reionization at the surface of He neutrals scattered from subsurface layers. It is shown that the tails provide in-depth information. (orig.).

1990-01-01

286

Applications of negative ions produced at surfaces in plasma physics  

Energy Technology Data Exchange (ETDEWEB)

The fundamental ionisation process of negative surface ionisation is described and two applications are discussed. One is in the so called surface-plasma sources which enable the production of intense negative ion beams. The second application is in the passive diagnosis of the charge exchange of neutrals emitted from hydrogen plasmas.

1982-01-01

287

Stochastic Finsler D-particle Space-Time Foam Enhances Dark Matter Relics  

CERN Document Server

Within the context of space-time (D-particle) foam in string/brane-theory it is demonstrated that it is possible to generate non-extensive statistics. The D-particle foam model involves point-like brane defects (D-particles), which provide the topologically non-trivial foamy structures of space-time. The D-particles can capture and emit stringy matter and this leads to a recoil of D-particles. It is indicated how one effect of such a recoil of D-particles is a back reaction on the space-time metric of Finsler type which is stochastic. We show that such a type of stochastic space-time foam can lead to cosmological effects similar to those induced by modifications of particle distributions within the framework of Tsallis entropies. The restrictions placed on the free parameters of the Finsler type metric are obtained from solving the Boltzmann ...

2010-01-01

288

A new lagrangian particle method to describe turbulent flows of fully compressible ideal gases  

CERN Document Server

There are several approaches to describe flows with particles e.g. Lattice-Gas Automata (LGA), Lattice-Boltzmann method (LBM) or smoothed particle hydrodynamics (SPH). These approaches do not use fixed grids on which the Navier-Stokes equations are solved via e.g. finite volume method. The flow is simulated using a multitude of particles or particle density distributions, which interacts and due to statistical laws and an even more fundamental approach than the Navier-Stokes equation, the averaged flow variables can be derived. After a short summary of the most popular particle methods the new DMPC (Dissipative Multiple Particles Collision) approach will be presented. The DMPC-model eliminates some of the weak points of the established particle methods and shows high potential for more accurate CFD solution especially in areas where standard ...

2008-01-01

289

Preparation of ZnO-Al2O3 Particles in a Premixed Flame  

DEFF Research Database (Denmark)

Zinc oxide (ZnO) and alumina (Al2O3) particles are synthesized by the combustion of their volatilized acetylacetonate precursors in a premixed air-methane flame reactor. The particles are characterized by XRD, transmission electron microscopy, scanning mobility particle sizing and by measurement of the BET specific surface area. Pure (?-)alumina particles appear as dendritic aggregates with average mobile diameter 43-93 nm consisting of partly sintered, crystalline primary particles with diameter 7.1-8.8 nm and specific surface area 184-229 m2/g. Pure zinc oxide yields compact, crystalline particles with diameter 25-40 nm and specific surface area 27-43 m2/g. The crystallite size for both oxides, estimated from the XRD line broadening, is comparable to or slightly smaller than the primary particle diameter. The specific surface area ...

2000-01-01

290

A model for estimating the hydraulic conductivity of granular material based on grain shape, grain size, and porosity  

Energy Technology Data Exchange (ETDEWEB)

Particle shape is an important parameter in numerous civil, environmental, and petroleum engineering applications. In ground-water flow, the shape of individual particles comprising the soil affects the soil`s pore size distribution and, hence, the important flow characteristics such as hydraulic conductivity and headloss. A model for delineating the relative importance of particle size, particle shape, and porosity, (and their interactions), in explaining the variability of hydraulic conductivity of a granular porous medium is developed and tested. Three types of porous media are considered in this work: spherical glass beads; granular sand; and irregularly shaped, shredded glass particles. A reliable method for quantifying the three-dimensional shape and packing of large samples of irregular particles based on their angle of repose is presented. The results of ...

1995-11-01

291

Size and morphology of heavy-duty vehicle particle emissions; Raskaan ajoneuvokannan hiukkaspaeaestoen koko ja morfologia - HD-PM  

Energy Technology Data Exchange (ETDEWEB)

Formation of particles from heavy duty diesel and CNG vehicles was studied in laboratory conditions. PM, nano and soot mode particle emissions formed from buses of Euro 2-5 -emission levels were studied in relation to age and type approval characteristics of the vehicle. Characteristic particle emission factors from city driving were obtained by driving the buses on VTT's heavy duty chassis dynamometer applying the transient Braunschweig city cycle. The vehicles were a representative set of Euro 2 to 3 emission categories, supplemented with Euro 4-5 (EEV) -targeted CRT, CNG and DPF cars. Particle number emissions from Euro 4 to 5 buses were 1/100-1/1000 and mass emissions 1/10-1/100 of those of the current fleet. Particle emission from natural gas buses and after an advanced CRT trap contained almost entirely liquid < 60 nm nano particles, which ...

2006-10-15

292

The combustion aerodynamics of a pulverized coal low NO{sub x} swirl burner in an industrial boiler  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the application of a Computational Fluid Dynamics (CFD) code (FLUENT) to predict temperature and velocity profiles, and particle trajectories in an industrial fired by a low NO{sub x} pulverized coal swirl burner. The predictions of the code were compared to experimental measurements of gas temperature, particle size distribution, and particle velocities. The diagnostics employed were a suction pyrometer and a Particle Counter Sizer Velocimeter Probe (PCSV-P). Good agreement was found between the temperature predictions and the measurements. In situ particle size distributions were predicted accurately using the Baum and Street model with a swelling factor of zero. The numerical modeling indicated that the Type II flow issued from the burner could be transformed into Type III flow, by eliminating swirl from the primary air stream, which provided the preferred ...

1996-12-31

293

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method  

Energy Technology Data Exchange (ETDEWEB)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe{sup 3+} and Fe{sup 2+}) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-15

294

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method  

International Nuclear Information System (INIS)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe"3"+ and Fe"2"+) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-01

295

New wear resistant composite material  

Energy Technology Data Exchange (ETDEWEB)

A composite material consisting of WC-Co particles in a steel matrix was fabricated by sintering mixtures of WC-Co particles and a steel powder and infiltrating the sintered pieces with a copper alloy. Its wear resistance and mechanical properties were studied as a function of the content in WC-Co particles and other characteristics of the composite material microstructure. Infiltration provided a simple means to obtain a strong cohesion between WC-Co particles and the steel matrix. An effective matrix protection against wear is obtained with relatively low additions of particles especially with a silica abrasive which is soft with respect to cemented carbide. The experimental results show that this material has good mechanical properties and wear resistance. Depending upon abrasion resistance, wear losses are reduced up to 10 times by a 30 vol% addition of cemented carbide ...

1983-01-01

296

Molecular dynamics study of TiO2/poly(acrylic acid-co-methyl methacrylate) and Fe3O4/polystyrene composite latex particles prepared by heterocoagulation  

British Library Electronic Table of Contents (United Kingdom)

All-atom molecular dynamics simulations were used to study the morphology of polymer/inorganic composite particles prepared by heterocoagulation. The results were also compared to those of our previous study of the preparation of TiO2/poly(acrylic acid-co-methyl methacrylate) and Fe3O4/polystyrene composite particles. In the simulation system, polymer or inorganic particles were simulated by surface-charge-modified C60 or Na atoms. Through a combination of analysis of the radial distribution functions of charged atoms and snapshots of the equilibrated structure, three kinds of particle distributions were observed under different conditions. When the polymer and inorganic particles had opposite surface charges and their sizes were very different, the composite morphology showed a core-shell...

2010-01-01

297

Impact of Hight Velocity Cold Spray Particles  

Energy Technology Data Exchange (ETDEWEB)

This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped ...

1998-12-01

298

Experimental limits on quarks, tachyons, and massive particles in cosmic rays  

Energy Technology Data Exchange (ETDEWEB)

A large detector with high redundancy is used to search for various types of anomalous particles in cosmic rays at sea level. The detector is sensitive to zenith angles between 45/sup 0/ and 90/sup 0/. Previously obtained limits on the fluxes of charge (1/3) and (2/3) particles are reduced to 2.9 x 10/sup -10/ and 2.6 x 10/sup -10/ cm/sup -2/sr /sup -1/ sec/sup -1/, respectively. The flux of ionizing tachyons is determined to be less than 2.4 x 10/sup -9/ cm/sup -2/ sr/sup -1/ sec/sup -1/. The massive-particle flux limit we obtain is inconsistent with previous claims of such particles assuming that these particles are isotropic in zenith angle.

1982-10-01

299

Experimental limits on quarks, tachyons, and massive particles in cosmic rays  

International Nuclear Information System (INIS)

A large detector with high redundancy is used to search for various types of anomalous particles in cosmic rays at sea level. The detector is sensitive to zenith angles between 45"0 and 90"0. Previously obtained limits on the fluxes of charge (1/3) and (2/3) particles are reduced to 2.9 x 10"-"1"0 and 2.6 x 10"-"1"0 cm"-"2sr "-"1 sec"-"1, respectively. The flux of ionizing tachyons is determined to be less than 2.4 x 10"-"9 cm"-"2 sr"-"1 sec"-"1. The massive-particle flux limit we obtain is inconsistent with previous claims of such particles assuming that these particles are isotropic in zenith angle.

300

An experimental method for measurement of strain distribution between wood the flour particles and polymer matrix on micro-mechanical level  

British Library Electronic Table of Contents (United Kingdom)

Wood plastic composites (WPCs) are comprised of wood flour and thermoplastic polymer. The matrix is typically high-density polyethylene, poly (vinyl chloride), or polypropylene. The effect of morphology and micromechanics of wood flour particles on the mechanical performance of the bulk composite is a relatively unexplored area. The knowledge about the in situ properties of wood particles and the interfacial properties between the wood particles and the polymer matrix in the bio-composites is very limited. The objective of this work is to characterize the full-field deformation and strain distribution in and around wood particles embedded in polymer matrix. The mechanical tests are performed in small-scale tensile loading stage on thin composite samples containing 1-3 wood particles orient...

2011-01-01

301

A principle of charged particle trapping by RF electromagnetic field in the spherical cavity  

Energy Technology Data Exchange (ETDEWEB)

A new principle of particle trapping in the simple spherical cavity using both electric and magnetic components of radiofrequency electromagnetic field is proposed. The electric component of H {sub 12} oscillating mode drives the fast particle oscillations, while the magnetic component synchronously bends the trajectories to the cavity center. A specially developed theory of particle stability predicts dense and energetic electron cluster in the trap. Numerical simulations of particle dynamics in the complete electromagnetic field taking into account both space charge and particle-induced magnetic field are in good agreement with the analytic results, giving a density of 2.6*10{sup 1} electrons/cm{sup 3} and an average kinetic energy of around 30 keV at an operating frequency of 3 GHz. Being used at lower frequency, spherical cavity can trap protons and heavier ions too, but with ...

2005-11-21

302

A new method for quantifiable and controlled dosage of particulate matter for in vitro studies: The electrostatic particulate dosage and exposure system (EPDExS)  

British Library Electronic Table of Contents (United Kingdom)

An exposure chamber is described for the quantifiable addition of fine and ultrafine aerosol particulate matter directly to cells and used to demonstrate the in vitro cytotoxicity of fine 1,4-naphthoquinone particles to murine lung epithelial cells. The electrostatic particulate dosage and exposure system (EPDExS) operates on the principle of electrostatic precipitation and is shown to deposit fine and ultrafine aerosol particles directly to cells with 100% efficiency for particle diameters in the range of 40-530nm. This range is not limited by the EPDExS, but rather by the aerosolization method used for this study. Numbers of particles deposited onto the cells are counted with a condensation particle counter, negating any need to calculate or estimate particle exposure. The process of par...

2008-01-01

303

Translocation of particles to the pleural space and tracheobronchial lymph nodes following lung deposition  

Energy Technology Data Exchange (ETDEWEB)

The translocation of particles from the alveolar compartment to the pleural space and tracheobronchial lymph nodes was investigated in rats over a 30 day period following the intrapulmonary instillation of 4 x 10/sup 8/ polystyrene microspheres (1.9 ..mu..m dia.). In initial studies, approx. =10/sup 4/ particles were found in the pleural space compartment on Days 1, 14 and 30 after particle deposition, and most of these were cell-associated. Subsequent pleural space studies indicated, however, that the particles found in this compartment were, at least in part, due to the pleural lavage technique, and, unlike observations reported for some fibers, the translocation of the particles used in our study to the pleural space does not represent an important lung clearance pathway. In regard to particle clearance to the tracheobronchial lymph nodes, the accumulation of ...

1985-01-01

304

DYNAMICS OF SOLIDS IN THE MIDPLANE OF PROTOPLANETARY DISKS: IMPLICATIONS FOR PLANETESIMAL FORMATION  

International Nuclear Information System (INIS)

We present local two-dimensional and three-dimensional hybrid numerical simulations of particles and gas in the midplane of protoplanetary disks (PPDs) using the Athena code. The particles are coupled to gas aerodynamically, with particle-to-gas feedback included. Magnetorotational turbulence is ignored as an approximation for the dead zone of PPDs, and we ignore particle self-gravity to study the precursor of planetesimal formation. Our simulations include a wide size distribution of particles, ranging from strongly coupled particles with dimensionless stopping time #tau#_s #ident to# #OMEGA#t_s_t_o_p = 10"-"4 (where #OMEGA# is the orbital frequency, t_s_t_o_p is the particle friction time) to marginally coupled ones with #tau#_s = 1, and a wide range of solid abundances. Our main results are as follows. (1) Particles ...

2010-10-20

305

Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques  

Energy Technology Data Exchange (ETDEWEB)

A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks ...

2005-06-11

306

The oncogenic transforming potential of the passage of single ? particles through mammalian cell nuclei  

UK PubMed Central (United Kingdom)

Domestic, low-level exposure to radon gas is considered a major environmental lung-cancer hazard involving DNA damage to bronchial cells by α particles from radon progeny. At domestic exposure...Full Text Available

1999-01-05

307

Study of particles trapped by a magnetic field  

Science.gov (United States)

A new type of radiation which occurs when particles are accelerated in the field of a longitudinal wave and in a transverse magnetic field is studied. The characteristics of such spontaneous radiation are obtained, and the influence of collective effects on the radiation is analyzed. The application of the findings to the theory of free electron lasers is discussed. 8 references.

1986-01-01

309

Particle size effect on strength, failure, and shock behavior in polytetrafluoroethylene-Al-W granular composite materials  

Science.gov (United States)

The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual ...

2008-11-01

310

Out of Gear $10 billion particle collider hasn't smashed a thing, but scientists still have high hop  

CERN Multimedia

Out of Gear $10 billion particle collider hasn't smashed a thing, but scientists still have high hop

2009-01-01

311

Organization of Bacteriophage Tail-Like Particles in Cells of Chromobacterium violaceum  

UK PubMed Central (United Kingdom)

A strain of Chromobacterium violaceum has been isolated which produces bacteriophage tail-like particles in high numbers. The extracellular morphology and the intracellular arrangement...Full Text Available

1972-05-01

312

Numerical calculations on flow and behavior of pulverized coal and ash particles in 2-stage entrained-flow gasifier  

Energy Technology Data Exchange (ETDEWEB)

Flow fields, temperature distributions, and particle trajectories in a 2-stage entrained-flow gasifier are calculated using a CFD code, FLUENT. Realizable k- {epsilon} model is used as a turbulent model. Because of swirling flow there appear recirculation regions near the burners. The characteristics of flow fields and temperature distributions in the gasifier are dependent on the swirl number of the system. Mean residence time of the particles in the reductor is inversely proportional to particle size, particle density and swirl number. As the swirl number is increasing, the particles injected from the combustor burners approach the wall near the combustor burners, which prevents the particles from entering the reductor and thus attaching the reductor wall. If the lower combustor burner angle is larger than the higher combustor burner angle for a given swirl ...

2001-07-01

314

Multiplicity distribution of charged particles in cosmic-ray proton induced nuclear reaction  

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.

1993-01-01

315

Energetic constraints on the creation of cell membrane pores by magnetic particles.  

UK PubMed Central (United Kingdom)

Naturally occurring and contaminant ferromagnetic and ferrimagnetic particles have been found within or near cells, and might allow pulsed magnetic fields to create transient cell membrane opening ("pores")....Full Text Available

1996-08-01

316

Effect of Particle Size on Compaction of Materials with Different Deformation Mechanisms with and without Lubricants  

UK PubMed Central (United Kingdom)

This work investigates the effect of excipient particle size on compaction properties of brittle, plastic and viscoelastic materials with and without added lubricants. Sieve cuts of Microcrystalline...Full Text Available

317

Dissipative particle swarm optimization  

CERN Document Server

A dissipative particle swarm optimization is developed according to the self-organization of dissipative structure. The negative entropy is introduced to construct an opening dissipative system that is far-from-equilibrium so as to driving the irreversible evolution process with better fitness. The testing of two multimodal functions indicates it improves the performance effectively

2005-01-01

318

Development program for magnetically assisted chemical separation: Evaluation of cesium removal from Hanford tank supernatant  

International Nuclear Information System (INIS)

Magnetic particles (MAG*SEP"S"M) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEP"S"M particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEP"S"M particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEP"S"M particles with a gamma ...

1994-05-09

319

Bragg curves of fission fragments in gases  

Energy Technology Data Exchange (ETDEWEB)

An unexpectedly high probability of collisions between the fission particles and the atoms in an ionization chamber along the entire particle track causes a strong fluctuation of the shapes of the Bragg curves. This fluctuation imposes an upper limit of the charge resolution ..delta..Z/Z which can be achieved.

1986-03-01

320

Biopersistence of nonfibrous mineral particles in the respiratory tracts of subjects following occupational exposure.  

UK PubMed Central (United Kingdom)

Transmission electron microscopy analysis (TEMA) was used to analyze the bronchoalveolar lavage fluid (BALF) of 262 subjects occupationally exposed (OE) to nonfibrous mineral particles (NFMP) and 42...Full Text Available

1994-10-01

321

Bacterial Particle Endocytosis by Epithelial Cells Is Selective and Enhanced by Tumor Necrosis Factor Receptor Ligands?  

UK PubMed Central (United Kingdom)

Bacterial pathogens use virulence strategies to invade epithelial barriers, but active processes of epithelial cells may also contribute to the endocytosis of microbial particles. To focus on the latter,...Full Text Available

2009-03-01

323

A plasma process for the synthesis of cubic-shaped silicon nanocrystals for nanoelectronic devices  

International Nuclear Information System (INIS)

Low pressure silane plasmas are known for their ability to synthesize silicon nanoparticles via gas phase nucleation. While in the past this particle formation has often been considered from the viewpoint of a contamination problem in semiconductor processing, we here describe a silane low pressure plasma that enables the synthesis of highly oriented, cubic-shaped silicon nanocrystals with a rather monodisperse size distribution. These silicon nanocubes have successfully been used in the manufacture of single nanoparticle vertical transistors. We discuss the advantages of this new paradigm of building nanoelectronic devices. The plasma synthesis process is characterized in more detail than in prior work. The particle nucleation, growth and shape evolution are studied. Results indicate that the process provides two spatially distinct zones: a diffuse plasma for particle growth and a constricted plasma zone for ...

2007-04-21

324

14 - NASA  

Science.gov (United States)

... and mean rainfall rates, Rm, in the liquid hydrometeor layers using the .... large latitudinal movement of cirrus cloud cover with the changing seasons. ... We study the statistical distribution of PSCs by particle composition using .... the high resolution Cloud Particle Imager (CPI) and standard PMS 2D-C and ...

325

Versatile charged particle activation technique for the analysis of the noble metals  

Energy Technology Data Exchange (ETDEWEB)

The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements (PGE) and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a tandem Van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.

1982-01-01

326

Versatile charged particle activation technique for the analysis of the noble metals  

Energy Technology Data Exchange (ETDEWEB)

The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a Tandem van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.

1983-01-01

327

V51 Knight Shift in Fine V3Si Particles  

Science.gov (United States)

The Knight shift of vanadium (KV) in fine V3Si particles was studied. The average diameter (\\bar{d}) ranged from 60 to 8000 A. The strong temperature dependence of the KV characteristic of high-Tc A-15 compounds was weakened in the particles. KV at 77 K increased with a decrease in \\bar{d}. The above-mentioned trends were consistent with a broadening of the sharp peak in the electronic density of states around the Fermi energy in particles resulting from a perturbation of the surface.

1987-12-01

328

The viscoelastic composite with interface debonding  

British Library Electronic Table of Contents (United Kingdom)

The effect of particle/matrix interface debonding on composites consisting of elastic particles and viscoelastic matrix is studied. The interface debonding is represented by a nonlinear cohesive law for the high explosive PBX 9501. The Mori-Tanaka method gives the constitutive relation of the composite in terms of the properties of elastic particles, viscoelastic matrix, and nonlinear cohesive law for interfaces. For the example of a composite with spherical particles subject to hydrostatic tension, simple analytical expressions of the composite stress-strain relation are obtained. The strain rate and temperature have strong effects on the composite behavior. High strain rate and low temperature give high strength of the composite. However, the rate and temperature effects decrease as the ...

2008-01-01

329

The Pinch Technique and its Applications to Non-Abelian Gauge Theories  

CERN Document Server

Describes the Pinch Technique for constructing Green's functions for elementary particle theorists and graduate students.

2010-01-01

330

Tachyons: may they have a role in elementary particle physics  

Energy Technology Data Exchange (ETDEWEB)

The possible role of space-like objects in elementary particle physics (and in quantum mechanics) is reviewed and discussed, mainly by exploiting the explicit consequences of the peculiar relativistic mechanics of Tachyons. Particular attention is paid: (i) to tachyons as the possible carriers of interactions; (ii) to the possibility of ''vacuum decays'' at the classical level; (iii) to a Lorentz-invariant bootstrap model; (iv) to the apparent shape of the tachyonic elementary particles and its possible connection with the de Broglie wave-particle dualism. (author).

1985-01-01

332

Saturn's Recycling Rings - Cassini Solstice Mission - NASA  

Science.gov (United States)

Dec 12, 2007 ... This is an artist concept of a close-up view of Saturn's ring particles.

333

STUDY AND MODIFICATION OF CONVECTIVE STORMS  

Science.gov (United States)

... small water or ice particles by impaction ... flight recording; principally the hydrometeor charge unit ... capability of directing aircraft movements by radio ...

1963-06-30

334

Rapid and continuous hydrothermal crystallization of metal oxide particles in supercritical water  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on hydrolysis of 10 metal salt aqueous solutions of 6 metal oxides that was conducted in supercritical water. Continuous and rapid production of metal oxide fine particles was achieved by mixing a metal salt aqueous solution with preheated water fed from another line. The reaction time required was less than 2 min. Particle size, morphology, and crystal structure of the obtained metal (hydrous) oxides were examined. Particle size (20 to 600 nm) was different among the system but the size range was relatively narrow in all the cases.

1992-04-01

335

Radionuclide particle transport, sedimentation and resuspension in the Forsmark and Laxemar coastal regions  

Energy Technology Data Exchange (ETDEWEB)

In the safety assessment of a potential repository for spent nuclear fuel, it is important to assess the consequences of a hypothetical leak of radionuclides through the seabed and into a waterborne transport phase. Radionuclides adsorbed to sediment particles may be transported great distances through the processes of sedimentation and resuspension. This study investigates the transport patterns of sediment particles of two different sizes, released in the Forsmark and Laxemar area. The results show that the closed waters around Forsmark to a higher degree makes the particles stay in the area close to the release points

2007-12-15

336

Past, present and future of elementary particle physics  

International Nuclear Information System (INIS)

The 'elementary' particle physics began in 1935, when Hideki Yukawa published his pioneering pi-meson theory, and the problem of strong interaction was finally solved 40 years later by the establishment of the Standard Model. The composite models of hadrons by the Sakata school and Sin-itiro Tomonaga's renormalization theory for quantum electrodynamics played essential roles for finding this beautiful solution. It is really surprising that it took only 40 years to solve such desperately difficult problem. The 'elementary' particle physics then split into two new fields, quark-hadron physics' and 'unified (ultimate) theory of particle physics', which are now 30 years old already. (author)

2006-12-01

337

Particle emission in hydrodynamics: a problem needing a solution  

CERN Document Server

A survey of various mechanisms for particle emission in hydrodynamics is presented. First, in the case of sudden freeze out, the problem of negative contributions in the Cooper-Frye formula and ways out are presented. Then the separate chemical and thermal freeze out scenario is described and the necessity of its inclusion in a hydrodynamical code is discussed. Finally, we show how to formulate continuous particle emission in hydrodynamics and discuss extensively its consistency with data. We point out in various cases that the interpretation of data is quite influenced by the choice of the particle emission mechanism.

2004-01-01

338

Particle Entrainment Simulator at the US Army Engineer ...  

Science.gov (United States)

... operation, experimental data reduction, and application of PES results to studies related to estuarine and coastal sediment transport problems are ...

2005-09-01

339

One-particle characteristics in problems with allowance for complex configurations  

Energy Technology Data Exchange (ETDEWEB)

A method for the determination of different ''bare'' characteristics of the one-particle motion and one-particle basis in magic nuclei is described. The method is based on separating out the mixing with phonons from the phenomenological one-particle characteristics. By means of a generalization of the procedure for localization of the mass operator, relations linking the bare and phenomenological characteristics are obtained. The radial dependence of these characteristics in finite nuclei and the influence of the quasiparticle--phonon interaction on the phenomenological characteristics are studied. Calculations are performed for the neutrons in /sup 208/Pb.

1986-09-01

340

Numerical study of Cosmic Ray Diffusion in MHD turbulence  

CERN Document Server

We study diffusion of Cosmic Rays (CRs) in turbulent magnetic fields using test particle simulations. Electromagnetic fields are produced in direct numerical MHD simulations of turbulence and used as an input for particle tracing, particle feedback on turbulence being ignored. Statistical transport coefficients from the test particle runs are compared with earlier analytical predictions. We find qualitative correspondence between them in various aspects of CR diffusion. In the incompressible case, that we consider in this paper, the dominant scattering mechanism occurs to be the non-resonant mirror interactions with the slow-mode perturbations. Perpendicular transport roughly agrees with being produced by magnetic field wandering.

2010-01-01

342

Meteorologial Techniques  

Science.gov (United States)

... 2-93 An Atmospheric Particle Emits Electromagnetic ... atmospheric water vapor produces a hydrometeor. ... subject to wind movement (either blowing ...

2003-06-13

344

High Resolution Mesoscale Weather Data Improvement to ...  

Science.gov (United States)

... that defines hydrometeor categories for the duration of the simulation ... and to observe the movement of any particular system ... particle settling occurred ...

2007-03-01

345

Evaluation of Daytime Boundary Layer Heights from a ...  

Science.gov (United States)

... the vertical beam measures the movement of the ... be measured because the particle velocity in ... During precipitation, if the hydrometeor fall velocity is ...

2008-03-01

346

Emission of light charged particles accompanying uranium fission induced by 153-MeV protons  

Energy Technology Data Exchange (ETDEWEB)

The emission of light charged particles from heavy fragments of uranium fission induced by 153-MeV protons is studied. The probability of their emission is 2.7 x 10{sup - 2} per fission event. It is found that these particles affect the distribution of angles of fragment divergence and the angular distribution of heavy fragments with respect to the primary-proton beam. Experimental results suggest that the preequilibrium emission of particles is correlated with fission. Two mechanisms of interaction between 153-MeV protons and uranium nuclei are considered. 13 refs., 10 figs., 1 tab.

1995-12-01

347

EFFECTS OF QUARTZ PARTICLE SIZE AND SUCROSE ADDITION ON MELTING BEHAVIOR OF A MELTER FEED FOR HIGH-LEVEL GLASS  

Energy Technology Data Exchange (ETDEWEB)

The behavior of melter feed (a mixture of nuclear waste and glass-forming additives) during waste-glass processing has a significant impact on the rate of the vitrification process. We studied the effects of silica particle size and sucrose addition on the volumetric expansion (foaming) of a high-alumina feed and the rate of dissolution of silica particles in feed samples heated at 5 C/min up to 1200 C. The initial size of quartz particles in feed ranged from 5 to 195 {micro}m. The fraction of the sucrose added ranged from 0 to 0.20 g per g glass. Extensive foaming occurred only in feeds with 5-{micro}m quartz particles; particles {ge}150 {micro}m formed clusters. Particles of 5 {micro}m completely dissolved by 900 C whereas particles {ge}150 {micro}m did not fully dissolve even when the temperature reached 1200 C. Sucrose addition had ...

2010-07-28

348

Deuteron break-up by the 27.2 MeV- alpha particle  

International Nuclear Information System (INIS)

Russian 1974. USSR Grantsev, VI Dryapachenko, IP Kornilov, VA Nemets,

1974-01-29

349

Deuteron break-up by the 27,2 MeV-alpha particle  

International Nuclear Information System (INIS)

Russian (Oct 1974). USSR Grantsev, VI Dryapachenko, IP Kornilov,

1974-01-29

351

Decontamination factors and release rates of UO/sub 2/ particles from boiling pools of sodium  

Energy Technology Data Exchange (ETDEWEB)

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

1983-01-01

352

Decontamination factors and release rates of UO"2 particles from boiling pools of sodium  

International Nuclear Information System (INIS)

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

353

Decays of "8"8Kr and "8"8Rb  

International Nuclear Information System (INIS)

... isotopes minutes living radioisotopes nuclei odd-odd nuclei particle properties

354

Charged particles background due to electromagnetic processes at the VLEPP based Photon Linear Collider with ultimate luminosity  

Energy Technology Data Exchange (ETDEWEB)

We have made preliminary estimates of charged particles background at the 100x100 GeV Photon Linear Collider with ultimate luminosity. The charged particles background due to electromagnetic processes is located mainly in the small-angle range of the detector. At large angles, the number of background particles is much smaller. Analysis of the background (at least, in the range under consideration) shows that background conditions for the VLEPP-based Photon Linear Collider are better than at the VLEPP electron-positron collider. ((orig.)).

1995-02-01

356

Beam stability study based on the beam trajectory jitter in the KEKB injector linac  

International Nuclear Information System (INIS)

... Tsukuba, Ibaraki (Japan) 389 p. PARTICLE ACCELERATORS beam monitoring

2001-08-01

357

Angular distributions of light charged particles from /sup 252/Cf fission in the ranges 0-46/sup 0/ and 134-180/sup 0/  

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.

1985-06-03

358

Analytic description of X-ray fluorescence intensity as a function of the particle size in powder samples and pulp upon X-ray fluorescence analysis  

International Nuclear Information System (INIS)

Analytic expression is derived for X-ray fluorescence dependence on the particle size of powder and slurry media. The expression is obtained for a model of powder medium containing particles of different size and random distribution in the bulk of the sample. Limiting cases of homogeneous and slurry-like media are considered and expressions for calculation of the fluorescence intensity are derived. The results reasonably match the experiment for binary powder mixtures and thus provide evaluation of the powder particle size on the fluorescence intensity for multicomponent polydisperse powder medium

2007-11-01

360

A multiple sampling proportional counter for particle identification of relativistic heavy ions  

Energy Technology Data Exchange (ETDEWEB)

A multiple sampling dE/dx counter using a multiwire proportional chamber equipped with catbode pads was constructed for the multiple detection of dE/dx values along a particle trajectory. For low-energy particles this counter was proved to be useful as a Bragg-curve detector. At relativistic energies around E=14.6 GeV/nucleon good particle identification was obtained by cathode pad signals as well as anode signals for the range of projectile fragments from Z=1 (minimum ionization) up to a beam charge of Z=14. (orig.).

1990-11-15

361

A Review of Test Medium Contamination Effects on Test ...  

Science.gov (United States)

... solid particle contamination. Solid particulate impact is a good mechanism for surface heat transfer augmentation. The aug ...

1998-01-01

362

Test particle moving in an interior static spherically symmetric geometry  

Energy Technology Data Exchange (ETDEWEB)

The motion of a test particle moving in an interior static spherically symmetric geometry is investigated. The author concludes that an oscillatory motion with the test particle changing its motion from a free fall towards the center to an outward radial motion can not exist for any static interior spherically symmetric model.

1984-06-01

363

Spiral modes in the diffusion of a single granular particle on a vibrating surface  

International Nuclear Information System (INIS)

We consider a particle that is subject to a constant force and scatters inelastically on a vibrating periodically corrugated floor. At small friction and for small scatterers the dynamics is dominated by resonances forming spiral structures in phase space. These spiral modes lead to pronounced maxima and minima in the diffusion coefficient as a function of the vibration frequency, as is shown in computer simulations. Our theoretical predictions may be verified experimentally by studying transport of single granular particles on vibratory conveyors.

2004-11-29

364

Spinning tachyons as particle constituents  

International Nuclear Information System (INIS)

The motions of a classical free spinning point particle are extended to include the range of superluminal velocities. There is no formal change in the constraint-dependent functional relationship between observable mass and spin, i.e., trajectory, accompanying this extension. However, the theory now permits the specification, for superluminal velocities, of a linearly rising trajectory and naturally yields tachyon confinement. Therefore, unlike their subluminal counterparts, these tachyons can be considered candidates for elementary particle constituents.

365

Production of cumulative hadrons in quark models of flucton fragmentation  

International Nuclear Information System (INIS)

Quark models of production of cumulative particles and the EMC effect are analyzed. It is shown that all these models are characterized by a universal relation between the spectrum of cumulative nucleons and the cross section for cumulative particles containing valence quarks of the nucleus. This relation is tested for the deuteron, and the role of secondary nuclear processes for heavy nuclei is discussed. It is noted that the ''sea'' cumulative particles (K"-, p-bar) are particularly important for understanding the nature of the difference between the structure functions of a nucleus and of a free nucleon.

366

Particle identification through the measurement of the Bragg curve centroid  

Energy Technology Data Exchange (ETDEWEB)

A new method of particle identification of heavy ions through the measurement of the Bragg curve centroid and particle energy has been developed using a gas ionization chamber with a resistive anode layer. Z-resolutions comparable to the conventional ..delta..E-E counter telescope could be rather easily attained.

1983-07-01

367

Particle identification through the measurement of the Bragg curve centroid  

International Nuclear Information System (INIS)

A new method of particle identification of heavy ions through the measurement of the Bragg curve centroid and particle energy has been developed using a gas ionization chamber with a resistive anode layer. Z-resolutions comparable to the conventional #DELTA#E-E counter telescope could be rather easily attained. (orig.).

368

Optimizing semiconductor devices by self-organizing particle swarm  

CERN Document Server

A self-organizing particle swarm is presented. It works in dissipative state by employing the small inertia weight, according to experimental analysis on a simplified model, which with fast convergence. Then by recognizing and replacing inactive particles according to the process deviation information of device parameters, the fluctuation is introduced so as to driving the irreversible evolution process with better fitness. The testing on benchmark functions and an application example for device optimization with designed fitness function indicates it improves the performance effectively.

2005-01-01

369

Improved Conservation Properties for Particle-in-cell Simulations with Kinetic Electrons  

Energy Technology Data Exchange (ETDEWEB)

It is shown that a simple algorithm which exactly segregates between adiabatic and non-adiabatic electrons in particle-in-cell simulations of drift modes yields excellent conservation properties (e.g. particle number, energy) compared to the conventional df scheme. The removal of the free streaming term in the evolution of the marker weight is shown to be responsible for the improved linear and nonlinear properties of the simulated plasma.

2003-06-19

370

Hot Particles Research for Nuclear Power Plant in Wolsung  

Energy Technology Data Exchange (ETDEWEB)

The evaluation of the hazard posed to the skin by very small radioactive sources (diameter < 1mm) has become popularly known as the 'hot particle' problem in European and American nuclear reactor facilities. In this study, research to detect hot particle was performed in Wolsung Nuclear power plant (NPP) in Korea.

2007-10-15

371

Hot Particles Research for Nuclear Power Plant in Wolsung  

International Nuclear Information System (INIS)

The evaluation of the hazard posed to the skin by very small radioactive sources (diameter < 1mm) has become popularly known as the 'hot particle' problem in European and American nuclear reactor facilities. In this study, research to detect hot particle was performed in Wolsung Nuclear power plant (NPP) in Korea.

2007-10-01

372

Formation of nano-sized particles of a solid electrolyte by laser ablation  

Energy Technology Data Exchange (ETDEWEB)

Nano-sized particles of a lithium ion conductive solid electrolyte, LiTi{sub 2}(PO{sub 4}){sub 3}, were prepared by laser ablation. The obtained particles were ca. 10nm in diameter. X-ray powder diffraction and Raman spectroscopy showed that they were amorphous with local structure similar to the crystalline counterpart. They were crystallized by the heating at ca. 630{sup o}C. (author)

2005-08-26

373

Explicit equation for particle settling velocities in solid-liquid systems  

Energy Technology Data Exchange (ETDEWEB)

Zanker has recently presented nomographs for determining particle settling velocities in solid-liquid systems. These nomographs were based on the general correlations developed by Barnea and Mizrahi and Barnea and Mednick. This work presents an equation directly computing particle settling velocities, eliminating the uncertainty associated with nomographs.

1981-11-01

374

Experimental and evaluated nuclear plus interference cross sections for light charged particles  

Energy Technology Data Exchange (ETDEWEB)

Experimental and evaluated integral parameters derived from nuclear plus interference differential elastic scattering cross sections are presented for all projectile/target combinations of the particles p, d, t, /sup 3/He, and ..cap alpha... The data include reaction rates, average fractional energy losses per collision and per unit path length, and average laboratory scattering cosines. The resulting parameters are of potential use in analysis of charged-particle transport.

1980-07-04

375

Effect of WC particle size on grain growth inhibition in the WC-xVC-Co system  

Energy Technology Data Exchange (ETDEWEB)

The effect of WC particle size with the addition of VC as a grain growth inhibitor was investigated during the liquid phase sintering of WC-Co system. With increasing WC particle size at the same VC content, the effect of grain growth inhibition was increased. Also, with increasing the VC content, the grain shape of WC was changed from the faceted shape to the distorted shape, and the step density of the WC grain was increased. (orig.)

2003-07-01

376

Direct conversion of fusion energy into the electric one in the 'Dragon' magnetic confinement system  

International Nuclear Information System (INIS)

It is shown that recuperator in which the thermal energy of particles is transformed into electric oue under drift in crossed fields is naturally coupled with dragontype magnetic confinement system, so the recuperation process can be initiated in the dragon magnetic field. A number of questions occuring under analysis of recuperator-dragon system is considered, including the dynamics of particle transfer to the recuperator, the share of particles entering the recuperator, the effect of rotational transform and the recuperation efficiency.

377

Deposition and removal of sub-micron particles of magnetite at the surface of alloy 800. AECL research No. AECL-11015  

Energy Technology Data Exchange (ETDEWEB)

This report measured the rate of isothermal deposition of sub-micron particles of magnetite onto the surface of Alloy 800 at pH of 4.2-9.3 at Re=10,000 and a fluid temperature of 25C. Deposition is modelled as a two-step process, the transport of particles to the surface region followed by attachment to the surface.

1994-12-31

378

Cumulative hadron production in quark models of flucton fragmentation  

International Nuclear Information System (INIS)

Quark models of cumulative particle production and EMS effect are analyzed. All the models are characterized by a universal relationship between the spectrum of cumulative nucleons and the cross section of cumulative particles containing valence nuclear quarks. This relationship is tested for a deuteron. The role is discussed played by secondary nuclear processes for heavy nuclei. A special role of ''sea'' cumulative particles (K"-, p-bar) is pointed out in understanding the nature of the difference between the structure functions of a nucleus and of free nucleon.

379

Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV  

Energy Technology Data Exchange (ETDEWEB)

Results of an experimental study of the interaction of 140 MeV alpha particles with /sup 90/Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from /sup 90/Zr(..cap alpha..,pp)X reactions, where both of the measured protons have energy ...

1980-01-01

380

Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV  

International Nuclear Information System (INIS)

Results of an experimental study of the interaction of 140 MeV alpha particles with _9_0Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from _9_0Zr(#alpha#,pp)X reactions, where both of the measured protons have energy distributions ...

381

Cleavage of tRNA within the mature tRNA sequence by the catalytic RNA of RNase P: implication for the formation of the primer tRNA fragment for reverse transcription in copia retrovirus-like particles.  

UK PubMed Central (United Kingdom)

The retrovirus-like particles of Drosophila are intermediates of retrotransposition of the transposable element copia. In these particles, a 39-nucleotide-long fragment from the 5' region of Drosophila...Full Text Available

1990-10-01

382

Battery using a metal particle bed electrode  

Energy Technology Data Exchange (ETDEWEB)

A zinc-air battery in a case including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit.

1991-01-01

383

Battery using a metal particle bed electrode  

Energy Technology Data Exchange (ETDEWEB)

A zinc-air battery in a case is described including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit. 7 figures.

1991-04-09

384

Alfven Eigenmode Stability with Beams in ITER-like Plasma  

Energy Technology Data Exchange (ETDEWEB)

Toroidicity Alfven Eigenmodes (TAE) in ITER can be driven unstable by two groups of energetic particles, the 3.5 MeV {alpha}-particle fusion products and the tangentially injected 1MeV beam ions. Stability conditions are established using the perturbative NOVA/NOVA-K codes. A quasi-linear diffusion model is then used to assess the induced redistribution of energetic particles.

2004-07-16

385

Research and Service Experience with Environmentally-Assisted Cracking in Carbon and Low-Alloy Steels in High-Temperature Water  

Energy Technology Data Exchange (ETDEWEB)

The most relevant aspects of research and service experience with environmentally-assisted cracking (EAC) of carbon (C) and low-alloy steels (LAS) in high-temperature (HT) water are reviewed, with special emphasis on the primary pressure boundary components of boiling water reactors (BWRs). The main factors controlling the susceptibility to EAC under light water reactor (LWR) conditions are discussed with respect to crack initiation and crack growth. The adequacy and conservatism of the current BWRVIP-60 stress corrosion cracking (SCC) disposition lines (DLs), ASME III fatigue design curves, and ASME XI reference fatigue crack growth curves, as well as of the GE EAC crack growth model are evaluated in the context of recent research results. The operating experience is summarized and compared to the experimental/mechanistic background knowledge. Finally, open questions and possible topics for further research are identified. Laboratory investigations revealed ...

2005-11-15

386

complexes of uranyl with outer-sphere perhalate anions  

Energy Technology Data Exchange (ETDEWEB)

The IR spectra of complexes of uranyl perhalates with antipyrine (AP), hexamethylphosphorus triamide (HMPTA), dimethyl sulfoxide (DMSO), and water with the composition (UO/sub 2/L/eta/)(Ha10/sub 4/)/sub 2/, where Ha10/sub 4/ = C10/sub 4//sup -/, Bro/sub 4//sup -/, 10/sub 4//sup -/ (except for DMSO and H/sub 2/O), L is a neutral ligand, n = 4 for HMPTA and n = 5 for the remaining L, were investigated. X-ray crystallographic analysis established that the investigated perhalate complexes of uranyl with the same neutral ligands are isostructural. It was established that in the complexes studied the Ha10/sub 4//sup -/ anions are outer-sphere anions, and the value of the frequency of the antisymmetrical stretching vibration of the uranyl group does not depend on the nature of the perhalate anion. From the values obtained for ..nu../sub 3/ UO /SUP 2/2/ /sup +/, the values of the multiplicity and energy of the uranium-ligand bond were estimated.

1986-07-01

387

White oils for high voltage cables  

Energy Technology Data Exchange (ETDEWEB)

''S-220'' white oil is used currently to impregnate and fill high voltage cables for 110-500 kilovolts; it has high electrical characteristics and meets production and use standards. High pressure and cooling problems, however, require filling cables with lower viscosity oils, while insulation needs still demand high viscosity. The authors developed a new white oil similar to S-220 using a neutral oil made in producing sulfonate additives. The process involved vacuum distillation, low-temperature paraffination, sulfation with oleum, neutralizing with ammonium hydroxide and simultaneous extraction of sulfo-salts and contact purification. The lowest content of aromatic hydrocarbons was sought. Dielectric qualities varied with viscosity. Satisfactory thermooxidational capability was found at 50/sup 0/C with an oil of no less than 50 mm/sup 2//sec viscosity. The final white oil had no more than 2% aromatic ...

1982-10-01

388

Upper bound for a three-photon excitation cross section in atomic argon in the ultraviolet regime  

Energy Technology Data Exchange (ETDEWEB)

A scheme of evaluating a generalized three-photon excitation cross section sigma/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p/sup 6/ /sup 1/S/sub 0/ state to the 3p/sup 5/4s'(1/2)/sub 1//sup 0/ state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of ..delta..lambda/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is sigma/sub (3)/ = 1.414 x 10/sup -80/ cm/sup 6/ s/sup 2/. .AE

1989-04-15

389

The preparation of highly absorbing cellulosic copolymers -the cellulose acetate/propionate-g. co-acrylic acid system  

Energy Technology Data Exchange (ETDEWEB)

A series of copolymers based on the cellulose acetate/propionate-g.co-acrylic acid system has been prepared under radiation-induced control. These copolymers have been assessed for their water-retention capacity both in an unmodified state and after ''decrystallization'' or ''neutralization'' treatments. The grafting of acrylic acid onto the cellulose acetate/propionate had little effect on the water retention power of the cellulose acetate/propionate. However, improvements to the water retentivity was obtained after ''decrystallization'' procedures had been carried out on the copolymers using selected alkali metal salts with methanol as the continuous medium. The water-retentivity of the copolymers increased with increase in the extent of grafting, though the effect is less pronounced at high graft levels. Neutralization of the ...

1990-01-01

390

The DITE tokamak experiment  

Science.gov (United States)

The DITE (Divertor Injection Tokamak Experiment) program has been undertaken to demonstrate the feasibility of impurity control by the use of a diverter in an injection-heated toroidal plasma configuration. Rather than behaving in accordance with neoclassical toroidal containment theory, the plasma is subject to various instabilities, particularly the resistive fluid MHD types, follows the empirical scaling of energy confinement time with plasma parameters observed in other plasma devices. DITE experiments have, however, extended the range of current and density. Impurities arising from plasma interactions with the vacuum vessel surface are controlled by the bundle divertor, which diverts a portion of plasma and power in the plasma scrape-off layer into a separate target chamber where impurities can be removed. Auxiliary plasma heating is provided by the injection of powerful beams of neutral hydrogen atoms produced by multi-aperture ion sources and hydrogen gas ...

1981-04-01

391

Studies of wind profile and estimation of surface layer scaling parameters for the coastal site of Tarapur  

International Nuclear Information System (INIS)

This paper presents the directional dependence of surface scaling parameters namely roughness length and corresponding friction velocity, for neutral category of Tarapur coastal site. The average roughness length of lowest value of 0.07 m (SW) and the highest value of 0.32 m (E) and average friction velocity of lowest value 1.6 m/sec(SSE) and a highest value 2.8 m/sec (SW) for the year 2006 were observed. Wind profile studies for the coastal site Tarapur with the wind data measured from meteorological tower of 30m which is at 1500m downwind fetch distance from the coastal line in the east direction gave the wind profile index parameter 'p' as 0.4, 0.5 and 0.75 for Unstable, Neutral and Stable weather conditions respectively. Sector Average Turbulent kinetic energy estimated as 17.7m2/s2 and its dissipation rate is 3.1 m2/s3 for the 10m elevation from the surface. A surface drag coefficient CD for the 10m height is 0.0076 for the smooth ocean ...

2007-06-05

392

Species abundance distributions in neutral models with immigration or mutation and general lifetimes  

CERN Document Server

We consider a general, neutral, dynamical model of biodiversity. Individuals have i.i.d. lifetime durations, which are not necessarily exponentially distributed, and each individual gives birth independently at constant rate \\lambda. We assume that types are clonally inherited. We consider two classes of speciation models in this setting. In the immigration model, new individuals of an entirely new species singly enter the population at constant rate \\mu (e.g., from the mainland into the island). In the mutation model, each individual independently experiences point mutations in its germ line, at constant rate \\theta. We are interested in the species abundance distribution, i.e., in the numbers, denoted I_n(k) in the immigration model and A_n(k) in the mutation model, of species represented by k individuals, k=1,2,...,n, when there are n individuals in the total population. In the immigration model, we prove that the numbers (I_t(k);k\\ge 1) of species ...

2010-01-01

393

Small and neutral Tc{sup v}O BAT, bisaminoethanethiol (N{sub 2}S{sub 2}) complexes for developing new brain imaging agents  

Energy Technology Data Exchange (ETDEWEB)

Bisaminoethanethiol (BAT) ligands with various gem-dimethyl and amide groups were prepared, and the corresponding neutral Tc-99m complexes were prepared and evaluated for their relative stabilities by ligand-exchange reactions. It was demonstrated that technetium complexes containing gem-dimethyl substituents have higher lipophilicities, whereas those with an amide group possess greater stability, which enhances ligand-exchange reaction. The most interesting observation was that the brain uptake in rats is not determined only by lipophilicity. Apparently, Tc-99m complexes with an amide functional group display lower brain uptakes in rats compared to those without an amide group. The brain uptake was strongly influenced by substituents on the BAT ligand. These factors are critically important and should be taken into consideration when designing Tc-99m-labeled agents for CNS receptor imaging.

1998-02-01

394

Self-consistent relativistic density-functional theory: Application to neutral uranium atom and some ions of lithium isoelectronic sequence  

Science.gov (United States)

In a relativistic density-functional theory the importance of the transverse photon contribution to the exchange potential in the high-density regime is pointed out. A neutral atom /sup 92/U is studied and its orbital energies calculated in the present scheme are compared with previous calculations based on relativistic Hartree, Dirac-Slater, and Dirac-Fock schemes and with experimental values from (electron spectroscopy for chemical analysis) ESCA studies. The present scheme is also used to calculate the orbital and total energies of some highly stripped ions of the Li isoelectronic sequence which occur as impurities in controlled thermonuclear plasma. These energies are found to be in close agreement with more involved Dirac-Fock results. Also, the relativistic effects significantly increase in going from C/sup 3 +/ to W/sup 71 +/ because the electronic density reaches values for which relativistic effects become large.

1980-07-01

395

Secondary reactions during CO hydrogenation on zeolite-supported metal catalysts: influence of alkali cations  

Energy Technology Data Exchange (ETDEWEB)

The effect of neutralizing cations on the secondary reactions of the primary products from CO hydrogenation over ion-exchanged zeolite-supported Ru catalysts was investigated using zeolites with different alkali cations (Li/sup +/, Na/sup +/, K/sup +/, Rb/sup +/, Cs/sup +/). The transformation of olefins (propylene and butene) on the zeolites without the metal, under conditions similar to those used for CO hydrogenation, was also studied in order to understand the effect of the various constituents of the support, i.e., the Broensted acid sites generated during catalyst preparation and the alkali cations, on possible secondary reactions of the primary olefinic products. It was established that secondary acid-catalyzed reactions of these primary products can play a major role in shaping product selectivity during CO hydrogenation over zeolite-supported catalysts. Depending on the concentration and the strength of the acid sites, various competitive reaction paths ...

1987-10-01

396

Recent status of the development of intense ion beams  

Energy Technology Data Exchange (ETDEWEB)

Taking the development of large current, negative ion sources which is in progress aiming at nuclear fusion reactors and the development of high luminance ion sources planned as a part of the Omega Project as the examples, the technology for generating high power ion beams is explained. Both these projects are positioned at the limit of the present technology of high power ion beam application as their targeted beam power reaches several tens MW. Consequently, the requirement for the ion sources is severe, and in particular, the generation of the ion beams having large current density with good convergence is beyond all precedents. The application of high power ion sources has been realized as the neutral beam injectors for large tokamaks. Also the hydrogen negative ion source of large current and the electrostatic acceleration technology for negative ion beams have been developed. Large plasma sources, the method of generating negative ions and the extraction of ...

1993-12-01

397

Next-to-leading order QCD corrections to the top quark associated with $\\gamma$ production via model-independent flavor-changing neutral-current couplings at hadron colliders  

CERN Document Server

We present the complete next-to-leading order (NLO) QCD corrections to the top quark associated with $\\gamma$ production induced by model-independent $tq\\gamma$ and $tqg$ flavor-changing neutral-current (FCNC) couplings at hadron colliders, respectively. We also consider the mixing effects between the $tq\\gamma$ and $tqg$ FCNC couplings for this process. Our results show that, for the $tq\\gamma$ couplings, the NLO QCD corrections can enhance the total cross sections by about 50% and 40% at the Tevatron and LHC, respectively. Including the contributions from the $tq\\gamma$, $tqg$ FCNC couplings and their mixing effects, the NLO QCD corrections can enhance the total cross sections by about 50% for the $tu\\gamma$ and $tug$ FCNC couplings, and by about the 80% for the $tc\\gamma$ and $tcg$ FCNC couplings at the LHC, respectively. Moreover, the NLO corrections reduce the dependence of the total cross section on the renormalization and factorization scale ...

2011-01-01

398

IR double-resonance spectroscopy applied to the 4-aminophenol(H{sub 2}O){sub 1} cluster  

Energy Technology Data Exchange (ETDEWEB)

The IR double-resonance techniques IR/R2PI (infrared/resonant 2-photon ionization), IR/PIRI (infrared-photo-induced Rydberg ionization) and IR-photodissociation spectroscopy are valuable tools to investigate structure, vibrations, and dynamical processes of neutral and ionic hydrogen-bonded clusters containing aromatic molecules. In this paper we report on the application of the IR double-resonance techniques to determine the NH and OH stretching vibrations of 4-aminophenol and 4-aminophenol(H{sub 2}O){sub 1}, both in the neutral (S{sub 0}) and ionic (D{sub 0}) ground state. All vibrational frequencies obtained for 4-aminophenol and the cluster are compared with the values obtained from ab initio and DFT calculations. In the S{sub 0} state, a trans-linear arrangement of 4-aminophenol(H{sub 2}O){sub 1} is obtained containing an O-H. O hydrogen bond. In the D{sub 0} state an overlay of two spectra can be observed resulting from the trans-linear ...

2001-03-01

399

Experience on resin pyrolysis  

International Nuclear Information System (INIS)

The Swedish State Power Board has together with Nukem, Hanau, West-Germany carried out pyrolysis o powder resins in a pilot plant with a capacity of about 30 kg/hr. The pyrolysis reactor with its afterburner and offgas scrubber system has been operated under steady state condition. About 2200 kg resins have been pyrolysed under November-December 1983 and the decontamination factor for Cs has been measured. Solidification of the residues from the pyrolysis reactor and scrubber water solutions has been carried out and various recipes with cement have been tested. The pyrolysis process has high decontamination factors and no offgas problems as the operating temperature of the reactor is Low. The residues from the reactor are chemically dead and can not cause swelling problems. Compared with a normal cementation process the final waste volume will be reduced with a factor of 4 if also the scrubber water after neutralization is solidified. The reduction factor will be 5 ...

400

Effects of soil pH on rhizoctonia damping-off of sugar beet and disease suppression induced by soil amendment with crop residues  

British Library Electronic Table of Contents (United Kingdom)

Effects of soil pH on damping-off of sugar beet by R. solani (AG2-2) and soil suppressiveness against the disease were studied by comparing disease incidences in pasteurized versus non-pasteurized, infested soils. Soil pH was correlated neither to disease incidence in five soils ranging from pH?4.5 to 7.2 nor to indigenous disease suppressiveness, the difference in disease incidences between non-treated soil and its pasteurized counterpart. When an alkaline soil was acidified with H2SO4, disease suppression markedly declined, increasing disease incidence in the non-pasteurized soil. Inversely, disease suppression was enhanced when an acidic soil was neutralized by adding Ca(OH)2. Soil amendment with dried peanut plant residue suppressed the disease in two pasteurized, near-neutral soils, l...

2011-01-01

401

Development of automatic analyzer for sulfuric acid, mixed nitric acid, and hydrofluoric acid in stainless pickling process; Sutenresu sansen rain'yo ryusan, shofussan jido bunsekiki no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

Stainless steel is pickled in pickling bath with the sulfuric acid and a mixture of hydrofluoric acid and nitric acid. Suitable equipment based on speedy and accurate chemical analysis for actual production lines has not been developed yet. The concentration of sulfuric acid can be analyzed by using the neutralization titration method. As a method of analyzing hydrofluoric acid in the mixed acid, the iron-acetylacetone complex discoloration absorbance method was adopted. For the concentration, of nitric acid, the method of subtracting the concentration of hydrofluoric acid from the total mixed acid amounts obtained by neutralization titration is adopted. Furthermore, the iron-salicylic acid complex absorbance method is adopted as a method of analyzing the iron content. By adopting these methods, the fully automated analyzer is developed. Completing analysis work can be shortened to 40 minutes by automated sampling from the acid pipes. The fully ...

1999-01-10

402

Comparison of susceptibility to pitting corrosion of AA2024-T4, AA7075-T651 and AA7475-T761 aluminium alloys in neutral chloride solutions using electrochemical noise analysis  

Energy Technology Data Exchange (ETDEWEB)

The susceptibility to pitting corrosion of AA2024-T4, AA7075-T651 and AA7475-T761 aluminium alloys was investigated in aqueous neutral chloride solution for the purpose of comparison using electrochemical noise measurement. The experimentally measured electrochemical noises were analysed based upon the combined stochastic theory and shot-noise theory using the Weibull distribution function. From the occurrence of two linear regions on one Weibull probability plot, it was suggested that there existed two stochastic processes of uniform corrosion and pitting corrosion; pitting corrosion was distinguished from uniform corrosion in terms of the frequency of events in the stochastic analysis. Accordingly, the present analysis method allowed us to investigate pitting corrosion independently. The susceptibility to pitting corrosion was appropriately evaluated by determining pit embryo formation rate in the stochastic analysis. The susceptibility was decreased in the ...

2008-01-15

403

Cars and fuels for tomorrow: A comparative assessment  

International Nuclear Information System (INIS)

Light duty vehicles, i.e. passenger cars and light trucks, account for approximately half of global transportation energy demand and, thus, a major share of carbon dioxide and other emissions from the transport sector. Energy consumption in the transport sector is expected to grow in the future, especially in developing countries. Cars with alternative powertrains to internal combustion engines (notably battery, hybrid and fuel-cell powertrains), in combination with potentially low carbon electricity or alternative fuels (notably hydrogen and methanol), can reduce energy demand by at least 50%, and carbon dioxide and regulated emissions much further. This article presents a comparative technical and economic assessment of promising future fuel/vehicle combinations. There are several promising technologies but no obvious winners. However, the electric drivetrain is a common denominator in the alternative powertrains and continued cost reductions are important for widespread deployment ...

2001-05-01

404

Capacitance behaviour of passive films on ferritic and austenitic stainless steel  

Energy Technology Data Exchange (ETDEWEB)

The electrochemical behaviour of passive films formed on one austenitic stainless steel (AISI 304) and one ferritic stainless steel (AISI 446) in solutions with pH between 0.6 and 8.4 was studied by capacitance measurements and photocurrent spectroscopy. Compositional characterization of the passive films was done by X-ray photoelectron spectroscopy. The capacitance increases with decreasing pH. Doping densities evaluated from Mott-Schottky plots are in the range 2-6 x 10{sup 20} cm{sup -3} and increased with the pH in the neutral/alkaline range while in pH 0.6, values above 10{sup 21} cm{sup -3} were found. The bandgap energy indicates two transitions, at 2.5-2.8 and 3.2 eV. The analytical data reveal that, as the pH increased, the films become enriched in Fe(II) and Fe(III), whereas the Cr(III) gradually decreases. The films formed at very low pH had a behaviour that contrasts with that of the films formed in the neutral/alkaline media. The ...

2005-03-01

405

Capacitance behaviour of passive films on ferritic and austenitic stainless steel  

International Nuclear Information System (INIS)

The electrochemical behaviour of passive films formed on one austenitic stainless steel (AISI 304) and one ferritic stainless steel (AISI 446) in solutions with pH between 0.6 and 8.4 was studied by capacitance measurements and photocurrent spectroscopy. Compositional characterization of the passive films was done by X-ray photoelectron spectroscopy. The capacitance increases with decreasing pH. Doping densities evaluated from Mott-Schottky plots are in the range 2-6 x 10"2"0 cm"-"3 and increased with the pH in the neutral/alkaline range while in pH 0.6, values above 10"2"1 cm"-"3 were found. The bandgap energy indicates two transitions, at 2.5-2.8 and 3.2 eV. The analytical data reveal that, as the pH increased, the films become enriched in Fe(II) and Fe(III), whereas the Cr(III) gradually decreases. The films formed at very low pH had a behaviour that contrasts with that of the films formed in the neutral/alkaline media. The films are ...

2005-03-01

406

Breakfast meal composition influences plasma tryptophan to large neutral amino acid ratios of healthy lean young men  

International Nuclear Information System (INIS)

The effect of a carbohydrate, a 20% protein, or a carbohydrate +0.3% tryptophan TRP breakfast on plasma large neutral amino acid ratio was studied in 6 healthy men. The carbohydrate-rich meal produced shifts in plasma amino acid concentrations such that plasma TRP/LNAA ratios increased from 0.13 to 0.15 (p<0.04) and the protein meal decreased the ratio from 0.14 to 0.11 (p<0.04) after 1 hour. Addition of 0.3% TRP to the carbohydrate-rich meal increased plasma TRP/LNAA ratios more than 2-fold. The TRP containing meal was thus the only one likely to influence brain 5-HT synthesis, although the difference between the plasma TRP/LNAA ratios after carbohydrate and protein breakfasts suggests that the brain may distinguish, by synthesizing more or less 5-HT, the composition of breakfast meals. (Author).

407

Acidic and neutral polar NSO compounds in Smackover oils of different thermal maturity revealed by electrospray high field Fourier transform ion cyclotron resonance mass spectrometry  

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-01

408

Transport and superconducting properties of RNi{sub 2}B{sub 2}C (R=Y, Lu) single crystals  

Energy Technology Data Exchange (ETDEWEB)

The in-plane resistivity, in-plane absolute thermopower, and upper critical field measurements are reported for single-crystal samples of YNi{sub 2}B{sub 2}C and LuNi{sub 2}B{sub 2}C superconductors. The in-plane resistivity shows metallic behavior and varies approximately linearly with temperature near room temperature (RT) but shows nearly quadratic behavior in temperature at low temperatures. The YNi{sub 2}B{sub 2}C and LuNi{sub 2}B{sub 2}C single-crystal samples exhibit large transverse magnetoresistance ({approx}6{endash}8{percent} at 45 kOe) in the ab plane. The absolute thermopower S(T) is negative from RT to the superconducting transition temperature T{sub c}. Its magnitude at RT is a few times of the value for a typical good metal. S(T) is approximately linear in temperature between {approx}150 K and RT. Extrapolation to T=0 gives large intercepts (few {mu}V/K) for both samples suggesting the presence of a much larger {open_quotes}knee{close_quotes} than would be expected from ...

1997-04-01

409

Crack growth behaviour of low alloy steels for pressure boundary components under transient light water reactor operating conditions (CASTOC)  

Energy Technology Data Exchange (ETDEWEB)

The CASTOC project addresses environmentally assisted cracking (EAC) phenomena in low alloy steels used for pressure boundary components in both Western type boiling water reactors (BWR) and Russian type pressurised water reactors (VVER). It comprises the four work packages (WP): inter-laboratory comparison test (WP1); EAC behaviour under static load (WP2), EAC behaviour under cyclic load and load transients (WP3); evaluation of the results with regard to their relevance for components in practice (WP4). The use of sophisticated test facilities and measurement techniques for the on-line detection of crack advances have provided a more detailed understanding of the mechanisms of environmentally assisted cracking and provided quantitative data of crack growth rates as a function of loading events and time, respectively. The effect of several major parameters controlling EAC was investigated with particular emphasis on the transferability of the results to components in service. The ...

2004-07-01

410

ISDD: A Computational Model of Particle Sedimentation, Diffusion and Target Cell Dosimetry for In Vitro Toxicity Studies  

Energy Technology Data Exchange (ETDEWEB)

Background: The difficulty of directly measuring cellular dose is a significant obstacle to application of target tissue dosimetry for nanoparticle and microparticle toxicity assessment. As a consequence, the target tissue paradigm for dosimetry and hazard assessment of nanoparticles has largely been ignored in favor of using metrics of exposure (e.g. ?g particle/mL culture medium, particle surface area/mL, particle number/mL). We have developed a computational model of solution particokinetics (sedimentation, diffusion) and dosimetry for non-interacting spherical particles and their agglomerates in monolayer cell culture systems. Particle transport to cells is calculated by simultaneous solution of Stokes Law (sedimentation) and the Stokes-Einstein equation (diffusion). Results: The In vitro Sedimentation, Diffusion and Dosimetry model (ISDD) was tested against measured transport ...

2010-11-30

411

Which differential circuit breaker in tomorrows accommodation?; Quel disjoncteur differentiel dans l'habitat de demain?  

Energy Technology Data Exchange (ETDEWEB)

Since several years, several manufacturers of circuit breakers from various countries (South Africa, UK, The Netherlands, USA..) try to impose in accommodations a highly sensitive electronic-type of differential circuit-breaker initially devoted to industrial installations where qualified and experienced professionals are present. This technical paper presents first the principles of the classical electromechanical circuit breakers and of the electronic circuit breaker, and then compares their relative efficiency and level of safety in residential use conditions (grounding schemes, voltage drops, rupture of the neutral conductor, rupture of the phase conductor, overvoltages). (J.S.)

2000-04-01

412

Ultrasensitive laser isotope analysis in an ion-storage ring  

Energy Technology Data Exchange (ETDEWEB)

We propose a novel method for ultrasensitive isotope analysis that combines magnetic mass selection, resonant charge-exchange neutralization, and resonant laser ionizaion. Our method attains high isotopic abundance selectivity by means of continuous multistage separation of ions stored in a small ring. For the environmentally interesting case of /sup 90/Sr versus /sup 88/Sr we estimate that sensitivity better than 10/sup -15/ for a throughput of 10/sup 13/ atoms/sec and an efficiency (after the ion source) greater than 10% are readily achievable.

1985-09-01

413

The electronic structure of organometallic complexes of the f elements XXV. Crystal field splitting pattern of the anionic complex [Cp_3Pr. NCS]"-  

International Nuclear Information System (INIS)

The absorption, emission and magnetic circular dichroism spectra of the anionic complex (Cp_3Pr. NCS)"- were measured at room and low temperatures. On the basis of these spectra the electronic structure in the f-f range could be derived. The parameters of an empirical Hamiltonian were fitted to the experimentally determined crystal field splitting pattern. Compared with the previously examined neutral Cp_3 Pr.X complexes the quadratic crystal field parameter B_0"2 is considerably reduced.

414

Semihard production of tensor mesons in. gamma. gamma. -collisions and the perturbative Odderon  

Energy Technology Data Exchange (ETDEWEB)

The cross sections of neutral tensor mesons T=a{sub 2}, f, f', ... production in the exclusive {gamma}{gamma}{yields}TT' or semiexclusive {gamma}{gamma}{yields}TX processes (three gluon exchange) in the semihard region s>>vertical stroketvertical stroke>1 GeV{sup 2} are calculated. The relation of investigated processes to the problem of perturbative Odderon is discussed. The possibility of measurements at LEP and at a future {gamma}{gamma}-colliders is discussed too. (orig.).

1992-03-01

415

Rocket borne solar eclipse experiment to measure the temperature structure of the solar corona via lyman-. cap alpha. line profile observations  

Energy Technology Data Exchange (ETDEWEB)

A rocket borne experiment to measure the temperature structure of the inner solar corona via the doppler broadening of the resonance hydrogen Lyman-..cap alpha.. (lambda1216A) radiation scattered by ambient neutral hydrogen atoms was attempted during the 16 Feb 1980 solar eclipse. Two Nike-Black Brant V sounding rockets carrying instrumented payloads were launched into the path of the advancing eclipse umbra from the San Marco satellite launch platform 3 miles off the east coast of Kenya.

1981-01-01

416

Plasma-edge studies in ISX-B and EBT-S using surface probes and laser-induced fluorescence  

Energy Technology Data Exchange (ETDEWEB)

Surface probe and laser-induced fluorescence measurements in ISX-B and EBT-S have made significant contributions to the understanding of plasma edge characteristics and plasma-surface interactions in these devices. Where comparison is possible, these techniques have led to results which are consistent with plasma diagnostics. Charge-exchange neutral sputtering and self-ion sputtering have been identified as the dominent heavy impurity release mechanisms in ISX-B and EBT-S, respectively.

1982-08-01

417

Plasma production and flow in negative ion beams  

Science.gov (United States)

Plasma generated in low-density vapor by a negative ion beam has been studied experimentally and computationally. We show that space charge neutralization of the beam occurs at very low vapor density, and that correspondingly the electron density may be much less than the beam and plasma ion densities. When there is a large local gas density, as in a charge changing cell, the resulting high electron density is also localized to the same region. Therefore, very few electrons will reach a negative ion accelerator even if it is placed one or two beam diameters from such a cell.

1977-09-21

418

Phenomenological implication of KamLAND on lepton mass matrices  

CERN Document Server

By using a model independent Monte Carlo approach, we study the possible structure of charged and neutral lepton mass matrices, under the assumption of an U(2) horizontal symmetry (additional to the usual Standard Model ones) involving the light fermion generations. We assume the most general Majorana mass matrix for neutrinos. We update the results of our previous similar study, by inserting in the analysis the recent KamLAND data, that contributed to find a final solution to the Solar neutrino problem. The introduction of the new experimental data reduce the allowed regions in the nine dimensional space parameters, and show that our procedure gives stable solutions.

2003-01-01

419

Negative charges in liquid hydrogen and deuterium  

Energy Technology Data Exchange (ETDEWEB)

The temperature and pressure dependence of the mobilities of negative charges injected into liquid hydrogen and deuterium have been measured. The authors propose the existence of two types of charge carriers in liquid parahydrogen. One is a bubble with an electron inside while the other has higher mobility. Relaxation of the current through liquid hydrogen was observed. It is suggested that in liquid and solid hydrogen under {beta}-irradiation neutral complexes are created which can trap the negative charges and have a lifetime of about 10 hours. 6 refs., 5 figs.

1992-11-01

420

Mechanism of iron inhibition by stearic acid Langmuir-Blodgett monolayers  

Energy Technology Data Exchange (ETDEWEB)

Many organic compounds can be adsorbed onto the interface of a metal and solution to form a thin film that inhibits the corrosion process according to a blocking and/or negative catalytic effect. Using the Langmuir-Blodgett (LB) technique, stearic acid (SA) monolayers were deposited onto the surface of an iron (Fe) electrode to study the inhibition effect and the mechanism of SA in a neutral medium. Molecular orientation and the number of deposited monolayers of SA were shown to have marked effects on inhibition of Fe corrosion. The inhibition mechanism depended mainly on blocking.

1995-01-01

421

Mechanical variations of diffused plasma parameters in a double plasma device  

International Nuclear Information System (INIS)

Experimentally it is shown that a movable grounded metallic plate placed inside a multi-dipole magnetic cage can vary the diffused plasma parameters such as density, plasma potential and electron temperature. Plasma is solely produced in the source section of a double plasma device by a dc hot filament discharge and a low-density plasma is produced in the target section by local ionization of neutral gas by the high energetic electrons coming from the source section. A grounded movable stainless steel plate is inserted in the target section of the device. The floating potential of the plate also changes depending on the position of the plate inside the magnetic cage.

2007-06-21

422

Magnetic braking in weakly ionized media  

International Nuclear Information System (INIS)

The combined magnetic braking-ambipolar diffusion problem in weakly ionized, rigidly rotating disks is studied. An analytical solution is presented for a disk whose angular velocity and magnetic yield vectors are aligned with the symmetry axis, illustrating the effects of the relative azimuthal drift of neutrals and ions. The effects of radial drift are added, commenting on the ratio of the characteristic ambipolar diffusion and magnetic braking time scales in high-mass and low-mass disks. A numerical calculation is used to show the combined action of these two processes. 31 references.

423

Low temperature partly ionized plasma in magnetic fusion devices: Present status and prospects  

Energy Technology Data Exchange (ETDEWEB)

The most striking achievement in magnetic fusion experiments during last few years was the discovery of plasma detachment from material targets, a much needed effect for plasmas with high power fusion parameters. Due to the very low heat loads on the targets observed in these regimes and potentially low erosion of the targets, detached regimes look attractive from the International Thermonuclear Experimental Reactor (ITER) design point of view. Thus the author has experimental proof for the possibility for a co-existence of fusion relevant hot plasma in the core and a low temperature partly ionized plasma at the edge of magnetic fusion device. Although somewhat similar behavior of edge plasma was considered theoretically even before plasma detachment was found experimentally, it was not clear in the beginning how these theoretical and experimental findings would fit together. Now, after a few years of intensive additional experimental and theoretical studies, a self-consistent physical ...

1998-12-31

424

Longer life for steam generators  

Science.gov (United States)

Eight years ago, corrosion and tube denting seriously threatened the reliability and design life of steam generators, especially for closed loop arrangements in pressurized water reactors (PWRs). Concentrated research by the Steam Generator Owners Group (SGOG) diagnosed the causes and produced effective solutions, notably guidelines for water chemistry control in the secondary loop. The guidelines recommend specific levels of water impurities and remedial actions to prevent cooling-water leaks in the condenser, prevent air leaks, limit corrosion product buildup, and remove some impurities while neutralizing others. Continued research in SGOB-II is investigating intergranular corrosion and stress corrosion cracking. 3 figures.

1984-10-01

425

Longer life for steam generators  

International Nuclear Information System (INIS)

Eight years ago, corrosion and tube denting seriously threatened the reliability and design life of steam generators, especially for closed loop arrangements in pressurized water reactors (PWRs). Concentrated research by the Steam Generator Owners Group (SGOG) diagnosed the causes and produced effective solutions, notably guidelines for water chemistry control in the secondary loop. The guidelines recommend specific levels of water impurities and remedial actions to prevent cooling-water leaks in the condenser, prevent air leaks, limit corrosion product buildup, and remove some impurities while neutralizing others. Continued research in SGOB-II is investigating intergranular corrosion and stress corrosion cracking. 3 figures.

426

Laser photoelectron spectroscopy of ions. Progress report, August 1, 1982-July 31, 1983  

Energy Technology Data Exchange (ETDEWEB)

We have undertaken a program which measures the photoelectron spectra of negative-ion beams. This experiment has afforded us direct information about these ions and the corresponding neutral radicals. Several ions and numerous radicals are believed to be crucial intermediates in combustion processes and flame chemistry. We have fabricated a spectrometer which directly measures electron affinities (EA). Knowledge of the EA and gas-phase acidity of a radical has enabled us to deduce several radical heats of formation and bond strengths.

1983-03-01

427

Isolation and biological activity of lipids from licorice (Glycyrrhiza glabra) roots  

British Library Electronic Table of Contents (United Kingdom)

Hexane extract of licorice (Glycyrrhiza glabra L.) roots was obtained and investigated. Hydrocarbons, sterol ethers, triacylglycerides, free fatty acids, and free sterols were identified. The extract contains 70% neutral and 30% polar lipids. It is established that the lipid fraction of licorice roots is more effective than the analogous fraction of rosehip oil in stimulating the reparative regeneration of skin. In addition, this fraction also exhibits pronounced antiinflammatory and antiulcer effects, while being virtually nontoxic. Based on these results, the lipid fraction of licorice roots can be recommended as a parent substance for creating effective preparations in various medicinal forms.

2007-01-01

428

Inorganic astatine chemistry: Formation of complexes of astatine  

Energy Technology Data Exchange (ETDEWEB)

The nature and properties of inorganic /sup 211/At-species formed in aqueous solutions under alkaline, neutral, acidic and oxidative conditions are studied through extraction of At with a variety of organic solvents, followed by the determination of the chromatographic, re-extraction and interaction behaviour of the extracted activity. It is concluded from the Rsub(f) values (on SiO/sub 2/) and the different affinities for a large amount of additives, that the extracted activity - formerly denoted as At-zero - exists of AtX compounds that may form AtXLsub(u) complexes, depending on the kind of solvent (L) used.

1983-01-01

429

Inorganic astatine chemistry: Formation of complexes of astatine  

International Nuclear Information System (INIS)

The nature and properties of inorganic "2"1"1At-species formed in aqueous solutions under alkaline, neutral, acidic and oxidative conditions are studied through extraction of At with a variety of organic solvents, followed by the determination of the chromatographic, re-extraction and interaction behaviour of the extracted activity. It is concluded from the Rsub(f) values (on SiO_2) and the different affinities for a large amount fo additives, that the extracted activity - formerly denoted as At-zero - exists of AtX compounds that may form AtXLsub(u) complexes, depending on the kind of solvent (L) used. (orig.).

430

Information processing, computation, and cognition  

British Library Electronic Table of Contents (United Kingdom)

Computation and information processing are among the most fundamental notions in cognitive science. They are also among the most imprecisely discussed. Many cognitive scientists take it for granted that cognition involves computation, information processing, or both ? although others disagree vehemently. Yet different cognitive scientists use ?computation? and ?information processing? to mean different things, sometimes without realizing that they do. In addition, computation and information processing are surrounded by several myths; first and foremost, that they are the same thing. In this paper, we address this unsatisfactory state of affairs by presenting a general and theory-neutral account of computation and information processing. We also apply our framework by analyzing the relatio...

2011-01-01

431

Development of a high current negative ion source for fusion application  

Energy Technology Data Exchange (ETDEWEB)

Negative ion based neutral beam injector is one of the most attractive heating system in future fusion reactors. In realizing the system, the crucial device which has to be developed is a high intensity negative ion source. Significant progress has been made on the negative ion source in these years. Among them, a few ampere negative ion beam were produced stably, while the divergence of negative ion beams becomes to be as low as < 10 mrad. We consider these results are demonstrating the potential of the negative ion source for the heating device in future reactors.

1988-11-01

432

Cosmological surveys with the Australian Square Kilometre Array Pathfinder  

CERN Document Server

This is a design study into the capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) in performing a full-sky low redshift neutral hydrogen survey, termed WALLABY, and the potential cosmological constraints one can attain from measurement of the matter power spectrum. We find that the full sky survey will likely attain 600,000 redshifts which, when combined with expected Planck CMB data, will constrain the Dark Energy equation of state to 20%, for the first time making cosmological constraints from radio observations competitive with the best existing optical surveys.

2011-01-01

433

Coherent correlation enhancement of outer shell photoionization cross sections of alkali-like ions  

Energy Technology Data Exchange (ETDEWEB)

An alkali-like ion interaction with inner electrons of an alkali-like ion leads to a significant increase in the photoionization cross section of the outer s electron. This occurs not only for ground-state ions with one s electron in the outer shell, but also when the outer s electron is in an excited state. The reason for this amplification, in addition to coherent enhancement in summing of the correlation amplitudes, is that the zero in the direct amplitude occurs below threshold. This leads to a constructive interference with the correlation amplitude above the photoionization threshold, in contrast to a destructive interference in the case of a neutral atom with the same electronic configuration, for which the zero occurs above threshold. Results of this research were published.

1995-08-01

434

Aqueous drilling fluids containing fluid loss additives  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an aqueous clay containing drilling fluid having present in an amount sufficient to reduce fluid loss of the drilling fluid, a copolymer of (1) from about 80% to about 98% by weight of acrylic acid and (2) from about 2% to about 20% by weight of itaconic acid. The copolymer has a weight average molecular weight of between about 50,000 to about 1,000,000, being in its free acid or partially or completely neutralized salt form and being at least water dispersible.

1987-03-03

435

Antiproton-Proton Channels in J/psi Decays  

CERN Document Server

The recent measurements by the BES Collaboration of J/psi decays into a photon and a proton-antiproton pair indicate a strong enhancement at the proton-antiproton threshold not observed in the decays into a neutral pion and a proton-antiproton pair. Is this enhancement due to a proton-antiproton quasi-bound state or a baryonium? A natural explanation follows from a traditional model of proton-antiproton interactions based on G-parity transformation. The observed proton-antiproton structure is due to a strong attraction in the 1S0 state, and possibly to a near-threshold quasi-bound state in the 11S0 wave.

2005-01-01

436

Angular scattering in electron capture and loss D/sup -/ beam formation processes  

Energy Technology Data Exchange (ETDEWEB)

The development of high energy (> 150 keV) neutral beams for heating and fueling magnetic fusion devices depends on the ability to produce well-collimated negative ion beams. The double capture charge-exchange technique is a known, scalable method. In order to maximize the overall efficiency of the process and to achieve the desired beam characteristics, it is necessary to examine the optical qualities of the beams as well as the total efficiency of beam production. A combined modeling and experimental study of the angular scattering effects in negative ion formation and loss processes has therefore been undertaken.

1980-01-01

437

A light charged Higgs boson in two-Higgs doublet model for CDF $Wjj$ anomaly  

CERN Document Server

Motivated by recent anomalous CDF data on $Wjj$ events, we study a possible explanation within the framework of the two-Higgs doublet model. We find that a charged Higgs boson of mass $\\sim$ 140 GeV with appropriate couplings can account for the observed excess. In addition, we consider the flavor-changing neutral current effects induced at loop level by the charged Higgs boson on the $B$ meson system to further constrain the model. Our study shows that the like-sign charge asymmetry $A_{s\\ell}^b$ can be of ${\\cal O}(10^{-3})$ in this scenario.

2011-01-01

438

[Destruction of radioactive particles by strains of Cladosporium cladosporoides (FRES.) de Vries].  

Science.gov (United States)

Reactions on the ionizing radiation of 14 Cladosporium cladosporioides strains were studied. Only 5 of them displayed radiotropizm. The ability of C. cladosporioides strains 4 and 5 with positive radiotropizm and museum C. cladosporioides strain 396 and its alb-mutant SM without positive radiotropizm to destruct radioactive particles of Chernobyl and explosion origin was studied. Two ways of radioactive particles destruction by C. cladosporioides were established, one of them is a direct way by fungal overgrowth of hot particles and the second one an indirect way only by fungal metabolites. Mycelium of the studied C. cladosporioides strains sorbed radionuclides from radioactive particles during cultivation on the liquid and agarized media. No certain inclinations of the individual strains to accumulation of radionuclides 137Cs or 152Eu were ascertained. PMID:12664550

439

Unified semi-microscopic description of low-energy proton and. alpha. -particle scattering by nuclei  

Energy Technology Data Exchange (ETDEWEB)

We develop the formalism of a unified semi-microscopic description of low-energy proton and {alpha}-particle interaction with nuclei. We analyze elastic and inelastic proton scattering at the energy 25.05 MeV and {alpha}-particle scattering at the energy 104 MeV by the {sup 90}Zr nucleus. Information is obtained on differences in the deformation of the proton and neutron distributions. We study the energy dependence of the semi-microscopic {alpha}-particle potential including the energy dependence of the potential geometry.'' We analyze the change in angular distributions of elastically scattered {alpha} particles with increase of energy and the contribution to the scattering cross section from nucleon-nucleon correlations.

1989-07-01

440

Three-dimensional, three-component wall-PIV  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert's law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle's projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional ...

2010-06-15

441

Self-consistent calculations within the Green's function method including particle-phonon coupling and the single-particle continuum  

Energy Technology Data Exchange (ETDEWEB)

The Green's function method in the Quasiparticle Time Blocking Approximation is applied to nuclear excitations in {sup 132}Sn and {sup 208}Pb. The calculations are performed self-consistently using a Skyrme interaction. The method combines the conventional RPA with an exact single-particle continuum treatment and considers in a consistent way the particle-phonon coupling. We reproduce not only the experimental values of low-and high-lying collective states but we also obtain fair agreement with the data of non-collective low-lying states that are strongly influenced by the particle-phonon coupling. (orig.)

2008-09-15

442

Radiation electromagnetic effect in germanium crystals under high-energy #alpha#-particle irradiation  

International Nuclear Information System (INIS)

Results of experimental investigation into radiation electromagnetic effect (REM) in samples of germanium crystals under approximately 40 MeV #alpha#-particle irradiation in a cyclotron are presented. A high level of excitation, volumetric character of generation of non-equilibrium carriers and formation of defects as well as the form of their spatial distribution are shown to result in some peculiarities of the EMF of the REM effect on the particle flux, fluence and sample parameters. Agreement of theoretical calculations, conducted with account of specificity of #alpha#-particle interaction with a crystal, and experimental data is obtained. It is revealed that the REM effect can be applied in obtaining data on spatial distribution of non-equilibrium carrier concentrations along the particle trajectory in the crystal.

443

Many-particle confinement by constructed disorder and quantum computing  

Energy Technology Data Exchange (ETDEWEB)

Many-particle confinement (localization) is studied for a 1D system of spinless fermions with nearest-neighbour hopping and interaction, or equivalently, for an anisotropic Heisenberg spin-1/2 chain. This system is frequently used to model quantum computers with perpetually coupled qubits. We construct a bounded sequence of site energies that leads to strong single-particle confinement of all states on individual sites. We show that this sequence also leads to a confinement of all many-particle states in an infinite system for a time that scales as a high power of the reciprocal hopping integral. The confinement is achieved for strong interaction between the particles while keeping the overall bandwidth of site energies comparatively small. The results show the viability of quantum computing with time-independent qubit coupling.

2005-10-01

444

Kinetic behavior of solid particle in chemical-looping combustion: suppressing carbon deposition in reduction  

Energy Technology Data Exchange (ETDEWEB)

In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was identified. 12 refs., 8 figs., 2 tabs.

1998-03-01

445

Extraction of biologic particles by pumping effect in a p-shaped ultrasonic actuator  

British Library Electronic Table of Contents (United Kingdom)

This paper presents a new method of extracting biologic particles from a mixture of particles. The method is based on the pumping effect in a p-shaped ultrasonic actuator, which has a gap between its two vibrating metal plates. An adhesive tape is placed at a proper position in the gap. Due to the pumping effect which is induced by the sound field in the gap, the particles with smaller mass and radius in the mixture can be pumped up to reach the adhesive tape; while the ones with larger mass cannot. Therefore, the particles with smaller mass and radius can be extracted from the mixture. A theoretical model which can well explain the operation principle and experimental phenomena is developed. By the experimental results and the theoretical analyses based on the model, the validity of the m...

2006-01-01

446

Embryo-damage induced nucleation of microcracks in an aluminum alloy under impact loading  

Energy Technology Data Exchange (ETDEWEB)

The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminum matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of ...

1995-06-01

447

Effects of surfaces and leachables on the stability of biopharmaceuticals  

British Library Electronic Table of Contents (United Kingdom)

Abstract Therapeutic proteins are exposed to various potential contact surfaces, particles, and leachables during manufacturing, shipping, storage, and delivery. In this review, we present published examples of interfacial- or leachable-induced aggregation or particle formation, and discuss the mitigation strategies that were successfully utilized. Adsorption to interfaces or interactions with leachables and/or particles in some cases has been reported to cause protein aggregation or particle formation. Identification of the cause(s) of particle formation involving minute amounts of protein over extended periods of time can be challenging. Various formulation strategies such as addition of a nonionic surfactant (e.g., polysorbate) have been demonstrated to effectively mitigate adsorption-i...

2011-01-01

448

Direct observation of polymerization in the oleic acid-ozone heterogeneous reaction system by photoelectron resonance capture ionization aerosol mass spectrometry  

British Library Electronic Table of Contents (United Kingdom)

High molecular weight products of the ozonolysis reaction of particle-phase 9-octadecenoic acid (oleic acid) have been studied by photoelectron resonance capture ionization (PERCI) mass spectrometry (MS). Oleic acid particles ( Formula Not Shown , Formula Not Shown ) were reacted with ozone (1.8x10-4atm) in a flow reactor at reaction times of 8 and 23s. Particles were sampled on-line with a differentially pumped particle inlet and chemically analyzed by PERCI-MS. PERCI is a soft ionization method that permits the direct measurement of relatively high molecular weight compounds, facilitating molecular identification. In addition to cyclic oxygenates, such as secondary ozonides and geminal diperoxides that were reported previously, we demonstrate the formation of polymers at the particle sur...

2006-01-01

449

Coupling of magnetostriction and electrostriction in the porous rheological composite  

Energy Technology Data Exchange (ETDEWEB)

The production method of the elastic composite containing ferrous particles and titanium barium particles dispersed in the porous silicone matrix is described in this article. Since it contains ferrous and titanium barium particles, this composite shows magnetorheological and also electrorheological properties. The electrostriction of composite samples in the electric field with maximal intensity 1.5x10{sup 6} V/m was investigated. The magnetostriction in the magnetic field with maximal induction 1 T was also investigated. It was found that samples elongate with increased electric field intensity, and the magnetic field induction was detected. By increasing the samples' elongation with increase of ferrous particles, titanium barium particles and pores number were also detected. In the investigated division of the electric and magnetic field the elongation changed in a ...

2008-08-15

450

Coenzyme Q10 nanoparticles prepared by a supercritical fluid-based method  

British Library Electronic Table of Contents (United Kingdom)

A supercritical fluid-based method is proposed to produce coenzyme Q10 (CoQ10) nanoparticles. First, CoQ10/polyethylene glycol 6000 composite particles are prepared by a modified PGSS (particles from gas-saturated solutions) process with controlling the flow rate of the gas-saturated solution. Then, CoQ10 nanoparticles are obtained by dissolving the composite particles into water. The effect of experimental variables of the modified PGSS process, including pressure, temperature, flow rate of the gas-saturated solution, and mass fraction of CoQ10, on the CoQ10 particle size and particle size distribution was investigated. Results show that CoQ10 slurry product with a median diameter of 190nm and yield of 89.8% can be prepared at an optimum condition (operating pressure of 25MPa, operating t...

2011-01-01

451

Chemical transformations of peptide containing fine particles: oxidative processing, accretion reactions and implications to the atmospheric fate of cell-derived materials in organic aerosol  

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...

2009-01-01

452

Asymmetry effect of particle size distribution on content uniformity and over-potency risk in low-dose solid drugs  

British Library Electronic Table of Contents (United Kingdom)

Most active pharmaceutical ingredients (API) exhibit particle size distributions with some degrees of asymmetry deviating from log-normality. A new log-skew-normal (L-S-N) distribution model is proposed for a systematic comparison of the asymmetry effect on content uniformity. The new model originated from the S-N model used by Azzalini gives a close approximation to real API particle size distribution. Monte-Carlo method was employed to simulate the dosage potency distribution. A high risk of over potency is uncovered when either the dose is low or API particle size distribution is positively skewed. This is due to the formation of pseudo heavy tail in potency distribution that decays slower than exponentially. Nomographs of API particle size versus dosage strength were constructed with a...

2010-01-01

453

Analysis of mixing in a Twin Cam mixer using smoothed particle hydrodynamics  

British Library Electronic Table of Contents (United Kingdom)

Smoothed Particle Hydrodynamics (SPH) is a Lagrangian, particle-based method that is well suited to industrial mixing simulations. Mass transport is simply the motion of the particles, and its grid-free nature means that it can easily accommodate complicated geometries involving moving parts and sharp corners. This article describes 2D SPH simulations of a Twin Cam mixer and compares the results against experimental data and results from two published finite element method (FEM) simulations. To analyze the mixing processes in the Twin Cam mixer, we present a method for calculating the Finite-Time Lyapunov Exponent (FTLE) using SPH particle data. The FTLEs can be used to locate the unstable and stable manifolds in the flow and indicate where mixing is either promoted or inhibited in the flo...

2008-01-01

454

Alpha energy distribution as a probe for the feeding of ND and SD bands in {sup 151,152}Dy nuclei  

Energy Technology Data Exchange (ETDEWEB)

The study of the {alpha}-particle energy distributions associated with ND and SD states in {sup 151,152}Dy has been carried out. The Dy isotopes were produced in the reaction {sup 37}Cl+{sup 123}Sb at 191 MeV via the ({alpha}5n) and ({alpha}4n) channels, respectively. In {sup 151}Dy the {alpha}-particle energy distributions associated to ND and SD are very different from each other, both at the low and high energy sides inducing a difference of 3 MeV in the {alpha}-particle mean energy. In {sup 152}Dy the situation is different; the {alpha}-particle spectral shapes are similar and a difference in the {alpha}-particle mean energy of only 0.7 MeV is deduced. A description in terms of energy localization of entry states is given. (orig.)

1999-10-01

455

A particle tracking transport method for the simulation of resident and flux-averaged concentration of solute plumes in groundwater models  

British Library Electronic Table of Contents (United Kingdom)

A new numerical technique called the convolution-based particle tracking (CBPT) method is developed to simulate resident or flux-averaged solute concentrations in groundwater models. The method is valid for steady-state flow and linear transport processes such as sorption with a linear sorption isotherm and first-order decay. The CBPT method uses particle tracking to take advantage of the ability of particle-based approaches to maintain sharp fronts for advection-dominated transport problems common in groundwater modeling and because of the flexibility of the random walk method to simulate a wide range of possible forms of the dispersion tensor. Furthermore, the algorithm for carrying out the convolution and superposition calculation from particle tracking results is very efficient. We sho...

2010-01-01

456

A Neuro-Fuzzy Multi Swarm FastSLAM Framework  

CERN Document Server

FastSLAM is a framework for simultaneous localization using a Rao-Blackwellized particle filter. In FastSLAM, particle filter is used for the mobile robot pose (position and orientation) estimation, and an Extended Kalman Filter (EKF) is used for the feature location's estimation. However, FastSLAM degenerates over time. This degeneracy is due to the fact that a particle set estimating the pose of the robot loses its diversity. One of the main reasons for loosing particle diversity in FastSLAM is sample impoverishment. It occurs when likelihood lies in the tail of the proposal distribution. In this case, most of particle weights are insignificant. Another problem of FastSLAM relates to the design of an extended Kalman filter for landmark position's estimation. The performance of the EKF and the quality of the estimation depends heavily on correct a priori knowledge of the process ...

2010-01-01

457

THE STATE OF STAR FORMATION AND THE INTERGALACTIC MEDIUM AT z #approx# 6  

International Nuclear Information System (INIS)

In the context of stellar reionization in the standard cold dark matter model, we analyze observations at z #approx# 6 and are able to draw three significant conclusions with respect to star formation and the state of the intergalactic medium (IGM) at z #approx# 6. (1) An initial stellar mass function (IMF) more efficient, by a factor of 10-20, in producing ionizing photons than the standard Salpeter IMF is required at z #approx# 6. This may be achieved by having either (a) a metal-enriched IMF with a lower mass cutoff of #>=#30 M_s_u_n or (b) 2%-4% of stellar mass being Population III massive metal-free stars at z #approx# 6. While there is no compelling physical reason or observational evidence to support (a), (b) could plausibly be fulfilled by continued existence of some pockets of uncontaminated, metal-free gas for star formation. (2) The volume-weighted neutral fraction of the IGM of _V#approx#10"-"4 at z = 5.8 inferred from the SDSS ...

2010-12-10

458

Passivation behavior of SUS 304 stainless steel in neutral solutions at elevated temperature  

Energy Technology Data Exchange (ETDEWEB)

Cyclic voltammograms of SUS 304 stainless steel in various neutral solutions such as Na/sub 2/SO/sub 4/ at high temperature were measured, as a successive study to previous report in which effects of temperature and pH on polarization behavior of stainless steel were studied. In this measurement Ag/AgCl reference electrode and platinum counter electrode were used in a static autoclave lined with inconel. Passive films formed in various conditions were analysed by electron diffraction and Auger spectroscopy. Results obtained were compared with anodic behavior of iron, chromium and nickel and with thermodynamical stabilities of their compounds. The main results are summarized as follows. (1) Stainless steel shows such electrochemical behavior as active dissolution, passivation and transpassivation in a deaerated neutral solution at 250/sup 0/C after fully reductive treatment of the specimen. In air-saturated solution, the peak of active ...

1981-03-01

459

PROGRESS IN BEAM FOCUSING AND COMPRESSION FOR WARM-DENSE MATTER EXPERIMENTS  

Energy Technology Data Exchange (ETDEWEB)

The Heavy-Ion Fusion Sciences Virtual National Laboratory is pursuing an approach to target heating experiments in the Warm Dense Matter regime, using spacecharge-dominated ion beams that are simultaneously longitudinally bunched and transversely focused. Longitudinal beam compression by large factors has beendemonstrated in the Neutralized Drift Compression Experiment (NDCX) with controlledramps and forced neutralization. Using an injected 30-mA K+ ion beam with initialkinetic energy 0.3 MeV, axial compression leading to ~;;50-fold current amplification andsimultaneous radial focusing to beam radii of a few mm have led to encouraging energy deposition approaching the intensities required for eV-range target heating experiments. We discuss the status of several improvements to our Neutralized Drift Compression Experiment and associated beam diagnostics that are under development to reach the necessary higher beam ...

2008-09-25

460

Behavioral modulation by mutilation pictures in women  

Scientific Electronic Library Online (English)

Abstract in english Previous studies have shown that women are more emotionally expressive than men. It is unclear, however, if women are also more susceptible to the emotional modulation of behavior imposed by an affective stimulus. To investigate this issue, we devised a task in which female subjects performed six sequential trials of visual target detection following the presentation of emotional (mutilation and erotic) or neutral pictures (domestic utensils and objects) and compared the (more) data obtained in the present study with those described in a previous study with male subjects. The experiment consisted of three blocks of 24 pictures and each block had an approximate duration of 4 min. Our sample consisted of 36 subjects (age range: 18 to 26 years) and each subject performed all blocks. Trials following the presentation of mutilation pictures (283 ms) had significantly slower reaction times than those following neutral (270 ms) ...

2004-03-01

461

A single amino acid substitution (R441A) in the receptor-binding domain of SARS coronavirus spike protein disrupts the antigenic structure and binding activity  

International Nuclear Information System (INIS)

The spike (S) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) has two major functions: interacting with the receptor to mediate virus entry and inducing protective immunity. Coincidently, the receptor-binding domain (RBD, residues 318-510) of SAR-CoV S protein is a major antigenic site to induce neutralizing antibodies. Here, we used RBD-Fc, a fusion protein containing the RBD and human IgG1 Fc, as a model in the studies and found that a single amino acid substitution in the RBD (R441A) could abolish the immunogenicity of RBD to induce neutralizing antibodies in immunized mice and rabbits. With a panel of anti-RBD mAbs as probes, we observed that R441A substitution was able to disrupt the majority of neutralizing epitopes in the RBD, suggesting that this residue is critical for the antigenic structure responsible for inducing protective immune responses. We also demonstrated that the RBD-Fc bearing R441A ...

2006-05-26

462

Alpha particle destabilization of the toroidicity-induced Alfven eigenmodes  

Energy Technology Data Exchange (ETDEWEB)

The high frequency, low mode number toroidicity-induced Alfven eigenmodes (TAE) are shown to be driven unstable by the circulating and/or trapped {alpha}-particles through the wave-particle resonances. Satisfying the resonance condition requires that the {alpha}-particle birth speed v{sub {alpha}} {ge} v{sub A}/2{vert bar}m-nq{vert bar}, where v{sub A} is the Alfven speed, m is the poloidal model number, and n is the toroidal mode number. To destabilize the TAE modes, the inverse Landau damping associated with the {alpha}-particle pressure gradient free energy must overcome the velocity space Landau damping due to both the {alpha}-particles and the core electrons and ions. The growth rate was studied analytically with a perturbative formula derived from the quadratic dispersion relation, and numerically with the aid of the NOVA-K code. Stability criteria in terms of the ...

1990-10-01

463

Photochemistry on surfaces. 2. Intermolecular electron transfer on colloidal alumina-coated silica particles  

Energy Technology Data Exchange (ETDEWEB)

Reductive quenching of two photoexcited ruthenium(II) complexes by an anionic electron donor, 2,2{prime}-azinobis(3-ethyl-benzothiazoline-6-sulfonate) (ABTS{sup 2{minus}}), in aqueous solution was examined by laser flash photolysis before and after adding positively charged colloidal (250-{angstrom} diameter) alumina-coated silica particles. The kinetics and quantum yields of electron transfer with an anionic sensitizer, RuL{sub 3}{sup 4{minus}} (L = bathophenanthroline disulfonate), and a cationic one, Ru(bpy){sub 3}{sup 2+} (bpy = 2,2{prime}-bipyridine), were compared. Coadsorption of ABTS{sup 2{minus}} and RuL{sub 3}{sup 4{minus}} by the particles greatly enhanced the rate of quenching such that only the reaction occurring on the surfaces of the particles was observed. Electron transfer from ABTS{sup 2{minus}} to RuL{sub 3}{sup 4-*} occurred by a static (nondiffusional) process, and the quenching efficiency was maximal ...

1989-02-23

464

Electrochemical properties of LiFePO{sub 4} prepared via ball-milling  

Energy Technology Data Exchange (ETDEWEB)

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

2009-04-01

465

Development of magnetic separation system of magnetoliposomes  

Energy Technology Data Exchange (ETDEWEB)

The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and the filter consisting of ferromagnetic particle. By doing so, we confirmed that Fe{sub 3}O{sub 4} of 20 nm ...

2009-10-15

466

Control of airborne particle concentration and draught risk in an operating room  

Energy Technology Data Exchange (ETDEWEB)

The influence of location of airborne particle source, ventilation rate, air inlet size, supply air velocity, air outlet location, and heat source on the distributions of airborne particle concentration and draught risk in an operating room is investigated. The investigation is carried out by using a flow program with the k-[epsilon] model of turbulence. Based on a standard case, five cases, each with one changed parameter, are computed, and the detailed field distributions of air velocity, temperature, airborne particle concentration, and draught risk are presented. The parametric study concludes that, for a better air quality and thermal comfort, it is desirable to use a higher inflow rate, a larger inlet area, and a uniform velocity profile of supply air. Outlet location and heat source have little influence on the distributions of the particle concentration in the room. It has also been found that ...

1992-01-01

467

Adsorption of mercury vapor on particles  

Energy Technology Data Exchange (ETDEWEB)

The adsorption of mercury vapor on particles was studied by using soot particles generated by incineration of sewage sludge (EP-ash) and activated carbon particles. Through the experiments, it was found that, at 298 K, the EP-ash has a fairly high adsorption capacity for mercury vapor in the order of 10/sup -6/g/g, which is between that of the ordinary soils and that of activated carbon particles. Furthermore, it was found that physical adsorption of mercury vapor on the studied particles at high temperature is described by Dubinin's equation. On the basis of the equation, it was shown that EP-ash physically adsorbs very little mercury at high temperature, and therefore, most mercury in the EP-ash is chemically adsorbed or contained in a form of mercury compounds. Nevertheless, the total amount of mercury contained in the particles is very little ...

1986-07-01

468

A model of coal particle drying in fluidized bed combustion reactor  

Energy Technology Data Exchange (ETDEWEB)

Experimental and theoretical investigation on drying of a single coal particle in fluidized bed combustor is presented. Coal particle drying was considered via the moist shrinking core mechanism. The results of the drying test runs of low-rank Serbian coals were used for experimental verification of the model. The temperature of the coal particle center was measured, assuming that drying was completed when the temperature equalled 100{sup o}C. The influence of different parameters (thermal conductivity and specific heat capacity of coal, fluidized bed temperature, moisture content and superheating of steam) on drying time and temperature profile within the coal particle was analyzed by a parametric analysis. The experimentally obtained results confirmed that the moist shrinking core mechanism can be applied for the mathematical description of a coal particle drying, while dependence ...

2007-02-15

469

Proposal to neutralize acid fluids from wells in the Los Humeros, Pue., geothermal field; Propuesta para la neutralizacion de fluidos acidos provenientes de pozos del campo geotermico de Los Humeros, Pue.  

Energy Technology Data Exchange (ETDEWEB)

Neutralizing an acidic fluid consists of adding a sodium hydroxide solution to neutralize the H group of acids, therefore increasing the pH. The injection of sodium hydroxide has to be continuous and at a proper depth inside the well to protect against the corrosion of casing and surface equipment. Neutralization is a common practice used in geothermal fields, such as at The Geysers in the US and Miravalles in Costa Rica-places where aggressive fluids cause problems for extracting and using geothermal fluids commercially. A zone surrounding wells H-4, H-16 and H-29 in the northern section of the Los Humeros, Pue., geothermal field, known as the Colapso Central, has shown evidence of aggressively acidic fluids. Several wells drilled in the area had to be repaired, thus plugging and isolating the deepest production zones. Well H-43 was drilled two years ago in the northern zone of the field, and even though it is not located ...

2009-07-15

470

Size and morphology of fine particle emissions from heavy-duty vehicles; Raskaan ajoneuvokannan hiukkaspaeaestoen koko ja morfologia - HD-PM  

Energy Technology Data Exchange (ETDEWEB)

Exhaust fine and ultra fine particle numbers, particle sizes, mass, shape, structure and density were studied from Euro II - EEV emission level heavy-duty vehicles. For total particle emission factors city buses were run on dynamic conditions simulating city bus driving. The new heavy-duty chassis dynamometer of VTT was used. Vehicles were a comprehensive sample of current city bus fleet, the type approved emission level of which was Euro II - Euro III. Also cleaner engines of Euro IV to EEV targeted emission level were included: CRT, CNG, DPF. Particle emissions of these buses were extremely low; numbers 1/100 - 1/1000 and masses 1/10 - 1/100 of those of the predominating techniques. Morphological properties of fine particle populations that represent majority of particle size distribution (Da < 500 nm) are being analyzed by image processing (Matlab) ...

2004-07-01

471

Formation of the natural sulfate aerosol  

Energy Technology Data Exchange (ETDEWEB)

Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various ...

1996-12-31

472

Charged particle spectra: 140 MeV #alpha# particle bombardment of "2"7Al, "5"8Ni, "9"0Zr, "2"0"9Bi, and "2"3"2Th  

International Nuclear Information System (INIS)

Complete energy spectra and angular distributions of the light charged particles (A < or = 4) were measured for the bombardment of "2"7Al, "5"8Ni, "9"0Zr, "2"0"9Bi, and "2"3"2Th with 140 MeV #alpha# particles. The spectral shapes of a given emitted particle are very similar for all target nuclei except in the region of the evaporation peak. The slopes of the energy spectra in the forward direction become steeper as the mass of the observed particle decreases and vary very rapidly with angles. The experimental data can be characterized by compound nuclear evaporation processes at low energies, or at backward angles, and by direct reactions, nonequilibrium components and projectile breakup processes at high energies and forward angles. The breakup cross section for #alpha# particles is found to be appreciable. The total yield of light charged particles is ...

473

Wear-resistance of manganese steel surface composites with cast tungsten carbide particles; Wc-W2C ryushi ni yori hyomen fukugokashita mangan ko no tai mamosei  

Energy Technology Data Exchange (ETDEWEB)

To make the surface composites with hard ceramics particles is an effective means for satisfying the request for the wear-resistance of the casting products. Covering casting is a general method for forming the composites by adding the adhesive into ceramics particles. However, due to the using of adhesive, pore and intermediate are easy to generate, and it is one of the reasons making the wear-resistance unstable. In the present study, it is attempted to form the wear-resistant composite layer by dispersing cast tungsten carbide (CTC) particles on the surface of wear-resistant 7 mass% Mn steel without using adhesives. Subsequently, the experiments on the wear-resistance of the obtained surface composites under several wear conditions are carried out. It is revealed by the results thereof that 7 mass% Mn steel surface composites with CTC particles have the wear-resistance which is even more excellent ...

1995-04-25

474

Time-Resolved Aerosol Collector for CCSEM/EDX Single Particle Analysis  

Energy Technology Data Exchange (ETDEWEB)

An automated Time Resolved Aerosol Collector (TRAC) has been developed for sequential sampling of field-collected aerosols for laboratory-based Computer Controlled Scanning Electron Microscopy/Energy Dispersed X-ray (CCSEM/EDX) single particle analysis. The collector is optimized for use of grid-supported 20 nm carbon films as deposition substrates. The carbon films have low enough X-ray background to permit EDX analysis down to 0.1-0.2 ?m particles, including detection of low-Z elements: C, N, & O. The TRAC provides unattended sampling onto a set of 151 individual grids, at sequential time intervals as short as 1 min. After collection, the samples are sealed and refrigerated pending analysis. The utility of the TRAC-CCSEM/EDX approach is exemplified using the aerosol samples collected during the Texas 2000 Air Quality Studies (Aug. 15 ? Sept. 15, 2000). We are able to quantitatively follow the time evolution in the relative contribution of ...

2003-01-02

475

The effect of the alcoholic solvent type on the formation of silica fine particles from alkoxide  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we investigated the effect of alcohol solvents (ethanol, n-propanol, and n-butanol) and isomeric alcohol solvents (iso-propanol, iso--butanol, and tert-butanol). In addition, we observed the effect of the mixed alcohol solvents on the particle formation as using a mixture od ethanol and butanol at a ratio od 30/70, 50/50 and 70/30 vol %, respectively. In case of ethanol solvent, particle size of silica showed the smallest and the narrowest size distribution among the various solvent. On the contrary, for the n-butanol solvent, largest broad distribution of particle size was observed. For the synthesis of particles having better spherical morphology and less agglomeration, alcohol solvent having no branches was considered appropriate. When mixed alcohol solvents were used, large silica particles with narrow size distribution were obtained, regardless of the ratio. 8 ...

2000-04-01

476

Solidification of radioactive waste effluents  

Energy Technology Data Exchange (ETDEWEB)

A process and apparatus for solidifying radioactive waste liquid containing dissolved and/or suspended solids is disclosed. The process includes chemically treating for pH adjustement and precipitation of solids, concentrating solids with a thin-film evaporator to provide liquid concentrate containing about 50% solids, and drying the concentrate with heated mixing apparatus. The heated mixing apparatus includes a heated wall and working means for shearing dried concentrate from internal surfaces and subdividing dry concentrate into dry, powdery particles. The working means includes a rotor and helical means for positively advancing the concentrate and resulting dry particles from inlet to outlet of the mixing apparatus. The dry particles may also be encapsulated in a matrix material. Entrained particles in the vapor stream from the evaporator and mixer are removed in an integral ...

1983-10-11

477

Pitting corrosion of copper coiled tubes in the air conditioning system having the open heat storage water tank; Kaihokei chikunetsuso reionsuika ni okeru kuchokiyo kokan no koshoku ni tsuite  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate pitting corrosion of copper coiled tubes for air conditioning systems with an open heat storage water tank, the effect of carbon films on the inner surface of copper tubes and fine corrosion-product particles in water as environmental corrosion factor on pitting corrosion was studied by field test under real environmental conditions. As a result, pitting corrosion of copper tubes was caused by synergistic effect of fine corrosion-product particles in water and carbon films. Generation of pitting corrosion was derived from deposition of the films and particles, while considerable growth of pitting corrosion was dependent on the particles. Time variation of spontaneous electrode potential also showed the effect of the film and particle. Pitting corrosion potential was estimated to be nearly 100mV vs. SCE. The following measures against pitting corrosion were ...

1998-11-15

478

Particle size effects on the desorption properties of nanostructured magnesium dihydride (MgH2) synthesized by controlled reactive mechanical milling (CRMM)  

International Nuclear Information System (INIS)

In the present work the hydrogen desorption properties of nanostructured magnesium hydride (MgH2) synthesized by controlled reactive mechanical milling (CRMM) of elemental Mg powder under hydrogen are investigated. A profound effect of the particle size of synthesized MgH2 hydride on its hydrogen desorption characteristics measured by differential scanning calorimetery (DSC) has been found. All synthesized MgH2 powders are characterized by a double hydrogen desorption peak. Furthermore, below a certain threshold particle size the DSC desorption temperature of the peak doublet starts decreasing rapidly with decreasing of the mean hydride powder particle size (expressed as equivalent circle diameter-ECD). In contrast, the nanograin (crystallite) size of MgH2 does not seem to have apparent effect on the DSC desorption temperature. It is also observed that for powder particles smaller than some threshold ...

2006-11-09

479

Particle production in nuclear collisions and dissociation of nuclei into nucleons  

International Nuclear Information System (INIS)

An attempt to classify experimental data and to present new approach for the problem of cumulative production of particles and high-transverse momentum particles (#pi#"#+-#, k"#+-#, p, p-bar, d) on Li"6, Be, Mg, Si, "5"4","5"6","5"8Fe, "5"8","6"1","6"4Ni, Cu, "6"4Zn, "1"1"2","1"1"8","1"2"4Sn, "1"4"4","1"5"4Sm, "1"8"2","1"8"6W, U nuclei is made in the review. Particle cumulative production, quark-parton structure function, A dependence of particle production on nuclei and in nuclear collisions and A dependence of inclusive cross sections of particle cumulative production are discussed. Reactions with dissociation on nucleons of deuteron, helium and compound nuclei are considered. Possibility of unified description of different processes is discussed in terms of nucleus flucton model. 35 refs.; 22 figs.

1988-06-14

480

Integral cross sections of 50.5 MeV #alpha# particle inelastic scattering on 1p and (2s-1d) shell nuclei and scattering mechanisms  

International Nuclear Information System (INIS)

Obtained experimental data on integral cross sections (ICS) of inelastic scattering of 50.5 MeV #alpha# particles with the excitation of "6","7Li, "9Be, "1"2","1"3C, "1"4C, "1"4N, "2"0Ne, "2"4Mg, "2"8Si nucleus low-lying energy levels are discussed. Regularities, detected in the behaviour of ICS forward scattering for 20-90 deg angles and backscattering for 90-160 deg angles for the target-nucleus under investigation are considered. Effect of reaction open channel number on #alpha#-particle scattering ICS where n,p,d- and #alpha#-channels were considered as the main channels for all the target-nuclei, is discussed. Dependence of #alpha#-particle scattering ICS on the target-nucleus level excitation energy and dependences of reaction open channel number on the channel spin, calculated for 50.5 MeV #alpha# particles and different target nuclei are shown in the diagrams. It is noted that the observed ...

481

Influence of second phase particles on fracture toughness in AZ31 magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Three kinds of thin AZ31 wrought magnesium alloys sheets were used in order to investigate the influence of the second phase particles on fracture toughness. From the theoretical model, the ratio of {lambda}{sub p}/d{sub p} would be estimated 5 {proportional_to} 6. On the other hand, from the microstructural observation, average particle spacing on each material was sample A: 13.1 {mu}m, sample B: 14.1, and sample C: 12 {mu}. In addition, average particle size on each sample was sample A: 2.1, sample B: 1.9, and sample C: 2.3 {mu}m. Therefore, the ratio of {lambda}{sub p}/d{sub p} calculated from fracture surface observation would be predicted 6 {proportional_to} 7. In comparison with the result of the prediction by theoretical analysis was in good agreement with the result of fracture toughness observation. It was found that the variation in plane-strain fracture toughness on AZ31 were affected by both of ...

2004-07-01

482

High temperature strengthening mechanism of hafnium carbide in a tungsten-rhenium matrix  

Energy Technology Data Exchange (ETDEWEB)

The interrelationship between the testing temperature and HfC strength increment of an arc-melted W-3.6Re-0.4HfC was determined from 1950 K to 2980 K in a vacuum of better than 1.3{times}10{sup {minus}5} Pa (10{sup {minus}7} torr). The present research was focused on the characteristic temperature at which the rapid coarsening of HfC particles occurred and the effect of the second-phase particle size on the high temperature strength properties of this material. It was found that the HfC particle strengthening was effective in a W-Re matrix up to a characteristic temperature of 2450 K in the short-term tensile test. Carbon was found to be the rate-limiting solute in the HfC particle growth. The strength of HfC strengthened alloy at temperature above 0.5 T{sub m} is proportional to the square root of particle volume fraction. The yield strengths of W-3.6Re-0.26HfC calculated based on ...

1991-01-01

483

High temperature strengthening mechanism of hafnium carbide in a tungsten-rhenium matrix  

International Nuclear Information System (INIS)

The interrelationship between the testing temperature and HfC strength increment of an arc-melted W-3.6Re-0.4HfC was determined from 1950 K to 2980 K in a vacuum of better than 1.3x10"-"5 Pa (10"-"7 torr). The present research was focused on the characteristic temperature at which the rapid coarsening of HfC particles occurred and the effect of the second-phase particle size on the high temperature strength properties of this material. It was found that the HfC particle strengthening was effective in a W-Re matrix up to a characteristic temperature of 2450 K in the short-term tensile test. Carbon was found to be the rate-limiting solute in the HfC particle growth. The strength of HfC strengthened alloy at temperature above 0.5 T_m is proportional to the square root of particle volume fraction. The yield strengths of W-3.6Re-0.26HfC calculated based on the ...

1991-01-06

484

Formation of Si-nanoparticles in a microwave reactor: Comparison between experiments and modelling  

International Nuclear Information System (INIS)

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

2005-02-01

485

Electrochemical properties of Cu{sub 2}O/Cu composite particles prepared by a novel and facile method  

Energy Technology Data Exchange (ETDEWEB)

In this study, Cu{sub 2}O/Cu composite particles were synthesized using an innovative chemical reduction method without any template and surfactant. X-ray diffraction (XRD) analysis revealed that the product mainly consisted of Cu{sub 2}O phase coexisting with a Cu phase. FE-SEM images showed that the octahedral shaped particles were Cu{sub 2}O. The electrochemical performance of the Cu{sub 2}O/Cu particles was investigated with regards to the working electrode material in alkaline solution. The particles had a maximum discharge capacity of 222.9 mAh/g at a discharge current density of 60 mA/g and a high value of 109.1 mAh/g after 50 charge-discharge cycles. Cyclic voltammetry revealed that the reaction between Cu{sub 2}O and Cu is the major electrochemical reaction during the charging and discharging process. Electrochemical impedance spectroscopy revealed that the formation of Cu{sub 2}O on the ...

2010-07-01

486

Crud behaviors and water chemistry in nuclear reactors  

International Nuclear Information System (INIS)

The deposit of radioactive corrosion products in the cooling systems of nuclear reactors becomes a serious problem for the personnel of facilities. Crud has an important role in the process of depositing radioactive corrosion products. The main components of crud are hematite, magnetite, nickel ferrite and so on, and the particles of these oxide compounds are distributed in water. Most of the behavior of crud are still not known. As for the mechanism of the production of crud, the Potter-Mann model has been proposed. However, the precipitation process of iron ions in water is unknown. The crud is defined as the particles filtered by 0.45 micrometer millipore filters. However, it is not known whether there are crud particles smaller than this size. The crud particles can be adsorbed on the filters by the surface electrochemical interaction. The adsorption of cations to crud particles ...

487

Computer image analysis of wear debris for machine condition monitoring and fault diagnosis  

Energy Technology Data Exchange (ETDEWEB)

Whenever moving surfaces interact, wear particles are produced. Microscopic examination of the morphology of such wear debris is an accepted method for machine condition monitoring and fault diagnosis. Wear particle analysis has not, however, been widely accepted in industry because it is dependent on expert interpretation of particle morphology and relies on subjective assessment criteria. Consequently, the methods are time consuming and expensive and are not always consistent. The use of automated computer image analysis systems to assess the morphology of debris promises to overcome these limitations by making the methods more time and cost efficient, and also more consistent and effective. The first step required for automation of the analysis procedure is to develop objective criteria for assessing the wear particle morphology. Numerical parameters to describe the morphology have been developed and ...

1995-03-01

488

Unbiased estimation of particle number using sections--an historical perspective with special reference to the stereology of glomeruli.  

DEFF Research Database (Denmark)

Methods for estimating particle number may be based on at least three different principles. Two of them, isolation of particles and indirect counting, have been predominant until recently. The new methods based on section pairs (disectors) are unbiased and far more efficient. The three principles and their historical developments are described, emphasizing that the newly developed principles have old roots, which were forgotten until recently. It is concluded, that 'learned societies' combined with individual enthusiasm are material for the spread and development of new ideas.

1989-01-01

489

Radiation-stimulated diffusion of aerosols  

Energy Technology Data Exchange (ETDEWEB)

The diffusion coefficient of particles in radioactive gases has been calculated with account of random wandering of aerosols (occurrence of local fields affecting the particles; recoils accompanying radiation emitted by particles, etc.). To determine the diffusion coefficient, the method of Fokker-Planck equation derivation was used. A formula is presented for calculating the radiation-stimulated diffusion coefficient. A linear growth of the diffusion coefficient with radioactivity is noted according to the formula, the diffusion coefficient is mainly determined by the field in the radiation damage region. The aerosol radioactivity may result in a more rapid deposition of aerosols in the pipelines and aerosol purification systems. The diffusion rate grows not only in the presence of intrinsic radioactivity but in case of external radiation exposure as well.

1984-04-01

490

Radiation vulcanization of natural rubber latex with polyfunctional monomers. 2  

Energy Technology Data Exchange (ETDEWEB)

Natural rubber latexes were vulcanized by ..gamma..-rays with two polyfunctional monomers, neopentylglycol diacrylate (A-NPG) and dimethacrylate (NPG). In comparison with A-NPG, NPG was more soluble in rubber particles, but it was less effective as an accelerating agent for the vulcanization because of the smaller rate of polymerization. On the other hand, the colloidal stability of the latex containing A-NPG was low because it was localized on the surface of rubber particles due to its poor solubility to the particles. The solubility of A-NPG was improved by adding A-NPG with solvents. The maximum tensile strength of the irradiated latex film was 350 kg/cm/sup 2/ at 3 Mrad.

1984-01-01

491

Radiation vulcanization of natural rubber latex with polyfunctional monomers  

International Nuclear Information System (INIS)

Natural rubber latexes were vulcanized by #gamma#-rays with two polyfunctional monomers, neopentylglycol diacrylate (A-NPG) and dimethacrylate (NPG). In comparison with A-NPG, NPG was more soluble in rubber particles, but it was less effective as an accelerating agent for the vulcanization because of the smaller rate of polymerization. On the other hand, the colloidal stability of the latex containing A-NPG was low because it was localized on the surface of rubber particles due to its poor solubility to the particles. The solubility of A-NPG was improved by adding A-NPG with solvents. The maximum tensile strength of the irradiated latex film was 350 kg/cm"2 at 3 Mrad. (author).

492

Production of cumulative hadrons in quark models of flucton fragmentation  

Energy Technology Data Exchange (ETDEWEB)

Quark models of production of cumulative particles and the EMC effect are analyzed. It is shown that all these models are characterized by a universal relation between the spectrum of cumulative nucleons and the cross section for cumulative particles containing valence quarks of the nucleus. This relation is tested for the deuteron, and the role of secondary nuclear processes for heavy nuclei is discussed. It is noted that the ''sea'' cumulative particles (K/sup -/, p-bar) are particularly important for understanding the nature of the difference between the structure functions of a nucleus and of a free nucleon.

1988-05-01

493

On some mechanisms of 27.2 MeV #alpha#-particle interaction with carbon nuclei  

International Nuclear Information System (INIS)

Using U-120 cyclotron in the course of correlation experiment one studied mechanisms of excitation and decay of "1"2C nucleus states resulting from irradiation of deuterium-polyethylene target by 27.2 MeV energy #alpha#-particle beam via recording of #alpha#-#alpha#-coincidence simultaneously with investigations of #alpha# + d-interactions. Production of "1"2C excited states decaying with the escape of #alpha#-particle and "8Be nucleus in the ground and the excited states is the basic mechanism of the studied #alpha# + "1"2C interaction

2001-05-01

494

Numerical study of semi-molten droplet impingement  

British Library Electronic Table of Contents (United Kingdom)

Due to the low thermal conductivity of ceramics large temperature gradients are present through the powder particles during plasma spray deposition. As a result the particles often impinge at the substrate in a semi-molten form; which in turn substantially affects the final characteristics of the coating being formed. This study is dedicated to the novel modelling development and simulation of a semi-molten droplet impingement. The study examines the impingement process during impact, spreading and solidification of semi-molten zirconia. The simulation provides an insight to the heat transfer process during impact and solidification of a semi-molten powder particle and illustrates the freezing-induced break-up mechanism at the splat periphery.

2011-01-01

495

Incompatibility of the Copenhagen interpretation with quantum formalism and its reasons  

CERN Document Server

It is proved the mathematical theorem, that the wave function describes the statistical ensemble of particles, but not a single particle. Supposition, that the wave function describes a single particle appears to be incompatible with formalism of quantum mechanics. One discusses the reasons, why this very simple statement has not been proved mathematically for many years. The reason lies in application of the trial and error methods for construction of the quantum mechanics. Application of this method as the main tool of investigation during eighty years generated "fitting mentality" of all microwold researchers.

2006-01-01

496

Effect of isopropyl alcohol on the surface localization and recombination of conduction-band electrons in Degussa P25 TiO_2. A pulse-radiolysis time-resolved microwave conductivity study  

International Nuclear Information System (INIS)

Conduction-band electrons, formed by pulse radiolysis of Degussa P25 TiO_2 particles, have been monitored by time-resolved microwave conductivity and found to undergo equilibrium localization and eventual recombination at the particle surface. In the presence of isopropyl alcohol recombination is retarded due to surface hole scavenging. The particle bulk can then be pumped with mobile electrons, which survive for seconds.

497

Charge distribution in alpha particle induced fission of "2"0"9Bi (Preprint No. NC-06)  

International Nuclear Information System (INIS)

The charge distribution in the alpha particle induced fission of "2"0"9Bi has been studied at alpha particle energy of 55.7 MeV and 58.6 MeV. The fractional cumulative yields of "9"7Zr, "9"9Mo, "1"0"1Mo and "1"1"2Pd have been determined using gamma ray spectrometry. The charge distribution have been found to be broad. (author). 4 refs., 1 ta b.

1991-02-04

498

Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisher"T"M magnetic particle processor prior to genome sequencing  

International Nuclear Information System (INIS)

Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher"T"M magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher"T"M magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification.

499

Alpha-particle scattering from Ca-nuclei  

International Nuclear Information System (INIS)

The possibilities, advantages, and difficulties of determining nuclear matter densities by elastic scattering of alpha-particles are generally discussed. On the basis of particular experimental data - 104 MeV alpha-particle scattering from "4"0,"4"2,"4"4,"4"8Ca - a refined folded potential is introduced using a density-dependent alpha-nucleon-interaction and target nucleus densities described by Fourier-Bessel-series. Thereby, the total nucleon densities of these isotopes were determined with little model dependence. The resulting root-mean-square radii and density differences are compared with other experimental results obtained by different methods. (orig.).

1979-07-01

500

A small particle selective emitter for thermophotovoltaic energy conversion  

Energy Technology Data Exchange (ETDEWEB)

This paper presents an analysis of the performance of a selective emitter using small particles of rare earth compounds stable at high temperatures in a low emittance inert gas stream. An expression for the spectral emissive power excluding radiation scattering was derived to include the radiation in the emission band, produced by electronic transitions of the rare earth ion, and the continuum radiation outside the emission band produced by the rare earth host. Preliminary results suggest that a selective emitter based on suspended rare earth oxide particles will have high efficiency and merits further experimental investigation. {copyright} {ital 1996 American Institute of Physics.}

1996-02-01