WorldWideScience
1

Metal atom diffusion in amorphous silica and at the silica surface. Progress report, December 1, 1982-December 1, 1983  

Energy Technology Data Exchange (ETDEWEB)

Objective is to study the effects of local structure, interatomic forces, and atom size on the mobility of metal atoms in amorphous silica and at the silica surface. EXAFS studies of Zn and Pt in silica are reported. (DLC)

1983-01-01

2

Focusing atomic beams by the dissipative radiation-pressure force of laser light  

Science.gov (United States)

An experimental realization of the focusing of an atomic beam by a spontaneous radiation pressure force is reported. A simple light field configuration for focusing an atomic beam is described which is formed by four divergent Gaussian laser beams propagating along the + or - x and + or - y directions of a Cartesian coordinate system. An experimental arrangement for the laser focusing is shown, and the experimental procedure is described. The resulting atomic beam profiles are shown and discussed. It is concluded that the experiments open up the possibility of gaining control over such parameters of atomic beams as their density and divergence. 7 references.

1986-02-01

3

Multiple-Bond Kinetics from Single-Molecule Pulling Experiments: Evidence for Multiple NCAM Bonds  

UK PubMed Central (United Kingdom)

The kinetic parameters of single bonds between neural cell adhesion molecules were determined from atomic force microscope measurements of the forced dissociation of the homophilic protein-protein bonds....Full Text Available

2005-11-01

4

The Future of US Nuclear Forces: Boom or Bust  

Science.gov (United States)

... Prior to 1977, one group, the Joint Committee on Atomic Energy, had oversight. Since 1977, this responsibility has been ...

2007-03-30

5

Atomic pioneers  

CERN Document Server

Atomic pioneers

1973-01-01

6

Atomic pioneers  

CERN Document Server

Atomic pioneers

1971-01-01

7

Development of homogeneous mixing technology of dispersion nuclear fuel  

Energy Technology Data Exchange (ETDEWEB)

The measurement methods of homogeneity of dispersion fuel were analyzed. The effects of mixing method, rotating speed, particle shape, particle size and moisture content on homogeneity of U{sub 3}Si/Al powder mixture were characterized by the apparent density measurement. The effects of fuel particle shape on green properties and optimum compaction conditions were investigated in U{sub 3}Si{sub 2}/Al powder compacts. 3 kinds of measurement method on the homogeneity were analyzed by apparent density measurement method, x-ray image contrast method and image analysis method of mixed powders or fuel rods. The homogeneity of dispersed fuel powder mixture was analyzed using three kinds of mixing, by apparent density measurements method. The homogeneity of powder mixture increased with rotating speed of the V-shape tumbler mixer. The comminuted irregular shaped particles and smaller particle size of fuel powders showed homogeneity improved of powder mixture due to ...

2000-04-01

8

Transversal Stiffness and Young's Modulus of Single Fibers from Rat Soleus Muscle Probed by Atomic Force Microscopy  

UK PubMed Central (United Kingdom)

AbstractThe structural integrity of striated muscle is determined by extra-sarcomere cytoskeleton that includes structures that connect the Z-disks and M-bands of a sarcomere to sarcomeres...Full Text Available

2010-02-03

9

Roles of curli, cellulose and BapA in Salmonella biofilm morphology studied by atomic force microscopy  

UK PubMed Central (United Kingdom)

BackgroundCurli, cellulose and the cell surface protein BapA are matrix components in Salmonella biofilms. In this study we have investigated the roles of these...Full Text Available

10

APPENDIX, GLOSSARY, AND BIBLIOGRAPHY - NASA Headquarters  

Science.gov (United States)

for sensitive personnel data. Based on the judgment of Task Force ...... Gunn, R ., Memorandum on Sub-Atomic Power Sources for Submarine ... Hunley, J., ed., The Birth of NASA: The Diary of T. Keith Glennan, SP-4105, ...

11

Nanostructure of thin gold films investigated by means of atomic force microscopy and X-ray reflectometry methods  

International Nuclear Information System (INIS)

A study of the thin gold film growth, during the deposition on glass substrate under UHV conditions at low temperatures, is presented. The complementary methods, the atomic force microscopy and grazing incidence x-ray reflectometry, are used for the research. It is shown that due to variation of the time of deposition from 2 to 50 min different kinds of thin Au films nanostructures are obtained: from discontinuous films consisting of isolated islands, via formation of the chains of islands, up to continuous films. (author)

2001-09-23

12

Study of both nature and topology of the nano-porous materials by the positron annihilation spectroscopy  

International Nuclear Information System (INIS)

By the methods of the angular distribution of photon annihilation, time distribution of photon annihilation, photoluminescence spectroscopy, Fourier IR-spectroscopy, atomic force microscopy the detail information on relation of the structural and physical properties of the porous nano-structures is obtained. Study of pores sizes in a different nano-porous materials, such as the porous silicon, porous anode aluminium oxide, porous solids exposed to light atoms ion implantation (hydrogen, deuterium, helium) is carried out.

2003-09-15

13

Investigation of A_1_g phonons in YBa_2Cu_3O_7 by means of linearized-augmented-plane-wave atomic-force calculations  

International Nuclear Information System (INIS)

We report first-principles frozen-phonon calculations for the determination of the force-free geometry and the dynamical matrix of the five Raman-active A_1_g modes in YBa_2Cu_3O_7. To establish the shape of the phonon potentials atomic forces are calculated within the linearized-augmented-plane-wave method. Two different schemes emdash the local-density approximation (LDA) and a generalized gradient approximation (GGA)emdash are employed for the treatment of electronic exchange and correlation effects. We find that in the case of LDA the resulting phonon frequencies show a deviation from experimental values of approximately -10%. Invoking GGA the frequency values are significantly improved and also the eigenvectors are in very good agreement with experimental findings. copyright 1997 The American Physical Society.

14

DBD Surface Modification of Polymers in Relation to the Spatial Distribution of Reactive Oxygen Species  

British Library Electronic Table of Contents (United Kingdom)

The homogeneity of a helium dielectric barrier discharge, working at atmospheric pressure and containing oxygen as contaminant, is assessed by mapping the spatial distribution of oxygen metastable atoms in relation to the uniformity of surface properties. Tunable diode laser absorption spectroscopy is used to monitor the time evolution of the absorption coefficient corresponding to the oxygen metastable atoms on the 35S2 level, as a function of the laser absorbing path, whereas bi-dimensional Abel transform is used to obtain local information on the space distribution of the metastable atoms in the discharge. The radial distribution of the surface properties is investigated using atomic force microscopy, contact angle measurement and X-ray photoelectron spectroscopy. The results show that ...

2011-01-01

15

Verification of maximum impact force for interim storage cask for the Fast Flux Testing Facility  

Energy Technology Data Exchange (ETDEWEB)

The objective of this paper is to perform an impact analysis of the Interim Storage Cask (ISC) of the Fast Flux Test Facility (FFTF) for a 4-ft end drop. The ISC is a concrete cask used to store spent nuclear fuels. The analysis is to justify the impact force calculated by General Atomics (General Atomics, 1994) using the ILMOD computer code. ILMOD determines the maximum force developed by the concrete crushing which occurs when the drop energy has been absorbed. The maximum force, multiplied by the dynamic load factor (DLF), was used to determine the maximum g-level on the cask during a 4-ft end drop accident onto the heavily reinforced FFTF Reactor Service Building`s concrete surface. For the analysis, this surface was assumed to be unyielding and the cask absorbed all the drop energy. This conservative assumption simplified the modeling used to qualify the cask`s structural ...

1996-06-01

16

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples  

British Library Electronic Table of Contents (United Kingdom)

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and...

2007-01-01

17

Validation of the GROMOS force-field parameter set 45A3 against nuclear magnetic resonance data of hen egg lysozyme  

Energy Technology Data Exchange (ETDEWEB)

The quality of molecular dynamics (MD) simulations of proteins depends critically on the biomolecular force field that is used. Such force fields are defined by force-field parameter sets, which are generally determined and improved through calibration of properties of small molecules against experimental or theoretical data. By application to large molecules such as proteins, a new force-field parameter set can be validated. We report two 3.5 ns molecular dynamics simulations of hen egg white lysozyme in water applying the widely used GROMOS force-field parameter set 43A1 and a new set 45A3. The two MD ensembles are evaluated against NMR spectroscopic data NOE atom-atom distance bounds, {sup 3}J{sub NH{alpha}} and {sup 3}J{sub {alpha}}{sub {beta}} coupling constants, and {sup 1}5N relaxation data. It is shown that the two sets reproduce structural properties ...

2004-12-15

18

Spontaneous radiation-induced alignment of dipole moments of atoms moving in a medium  

International Nuclear Information System (INIS)

The effect on an oscillator moving in a medium produced by that part of the radiative force which does not perform work but creates and angular moment is considered. It is shown that the radiative torque turns the dipole toward the axis along which it is moving. Near the axis of motion the dipole executes small oscilltions. The frequency of the oscillations is determined. This effect leads to spontaneous alignment of the dipole moments on moving through the medium. The feasibility of observing the effect experimentally is discussed.

1986-01-01

19

Hydrodynamic measurement of a single corrosion pit  

Energy Technology Data Exchange (ETDEWEB)

The hydrodynamics of gas evolution plays an important role in the pitting corrosion of metals. A new technique for the measurement of the local hydrodynamics caused by corrosion processes, using the atomic force microscope, has been presented in this work. The hydrodynamics of hydrogen evolution on Al surface due to pitting corrosion was studied. The characteristic features of the hydrodynamics are discussed. To the best of our knowledge this is the first local measurement of pitting corrosion hydrodynamics.

2004-11-01

20

Effect of ethnicity and treatments on in situ tensile response and morphological changes of human hair characterized by atomic force microscopy  

International Nuclear Information System (INIS)

Human hair fibers experience tensile forces during grooming and styling processes. The tensile response of hair is hence of considerable interest to the cosmetics industry. In this study, in situ tensile characterization studies have been carried out in an atomic force microscope (AFM) on different hair under different conditions. A custom-built AFM sample stage allows hair fibers to be loaded in tension. A technique to locate and image the same control area at different strains has been developed to study the changes in morphology that occur with deformation. Virgin Caucasian, Asian and African hair were studied to understand the differences between different ethnic hair types. Also, the tensile response and morphological changes of virgin, chemically damaged and conditioner-treated Caucasian hair after soaking were compared against the corresponding dry tensile response. Finally, virgin, damaged and treated Caucasian hair ...

2008-08-01

21

Improvement in the spectral response at long wavelength of a-SiGe:H solar cells by exponential band gap design of the i-layer  

Energy Technology Data Exchange (ETDEWEB)

A new band gap profile (exponential profile) for the active layer of the a-SiGe:H single junction cell has been designed and experimentally demonstrated. In this paper we compare its optical and electrical characteristics with the two more common profiles: the U- and V-shapes. As predicted by the simulations, the new profile combines the advantages of both profiles. Like the V-shape, the exponential shape reduces the amount of Ge in the i-layer, decreasing both the space charge defect density inside the i-layer and the recombination losses. It also improves the electric field. At the same time, the exponential shape generates the same current density as the U-shape.

2002-04-01

22

Calculation of the vibrational properties of LiMgAs  

Energy Technology Data Exchange (ETDEWEB)

We have studied the vibrational properties of the filled tetrahedral semiconductor LiMgAs and its binary analog AlAs by using the plane-wave pseudopotential method within density functional theory. The calculated lattice constants for the studied compounds are in good agreement with previous theoretical and experimental results. The phonon dispersion curves and phonon density of states are calculated by using density functional perturbation theory. The sound speeds in different directions are quantitatively similar in LiMgAs and AlAs. The assignment of the zone center modes to the relative motion of the atoms shows that the lower optic modes are due to the Mg-As pair vibrations, while for the upper ones the Li-Mg pair dominates, which is attributed to the smaller Mg atom mass. The longitudinal interatomic force constant of Mg-As is about 66% higher than that of Li-As, showing the relatively high covalency of the former ...

2009-07-29

23

Augmented-plane-wave calculations on small molecules  

International Nuclear Information System (INIS)

We have performed ab initio calculations on a wide range of small molecules, demonstrating the accuracy and flexibility of an alternative method for calculating the electronic structure of molecules, solids, and surfaces. It is based on the local-density approximation (LDA) for exchange and correlation and the nonlinear augmented-plane-wave method. Very accurate atomic forces are obtained directly. This allows for implementation of Car-Parrinello-like techniques to determine simultaneously the self-consistent electron wave functions and the equilibrium atomic positions within an iterative scheme. We find excellent agreement with the best existing LDA-based calculations and remarkable agreement with experiment for the equilibrium geometries, vibrational frequencies, and dipole moments of a wide variety of molecules, including strongly bound homopolar and polar molecules, hydrogen-bound and electron-deficient molecules, and ...

24

The nanostructure and microstructure of steels: Electrochemical Tafel behaviour and atomic force microscopy  

International Nuclear Information System (INIS)

The influence of chemical composition and heat treatment on a low-carbon steel, chromium steel and high speed steel has been examined by polarisation curves and electrochemical parameters deduced from the Tafel plots. The electrochemical corrosion resistance, which is small between the as-received steels become greater after heat treatment, following the order: carbon steel < chromium steel #approx# high speed steel. To explain these differences, the nano- and microstructure of the steels has been characterized by the ex situ techniques of atomic force microscopy and optical microscopy, before and after surface etching with Nital (a solution of 5% HNO_3 in ethanol). This causes preferential attack of the ferrite phases showing the carbide phases more clearly. From these nanostructural studies it was possible to better understand why the passive films formed on chromium steel and high speed steel have superior protective properties to those ...

2005-12-01

25

Simulating fullerene ball bearings of ultra-low friction  

Energy Technology Data Exchange (ETDEWEB)

We report the direct molecular dynamics simulations for molecular ball bearings composed of fullerene molecules (C{sub 60} and C{sub 20}) and multi-walled carbon nanotubes. The comparison of friction levels indicates that fullerene ball bearings have extremely low friction (with minimal frictional forces of 5.283 x 10{sup -7} and 6.768 x 10{sup -7} nN/atom for C{sub 60} and C{sub 20} bearings) and energy dissipation (lowest dissipation per cycle of 0.013 and 0.016 meV/atom for C{sub 60} and C{sub 20} bearings). A single fullerene inside the ball bearings exhibits various motion statuses of mixed translation and rotation. The influences of the shaft's distortion on the long-ranged potential energy and normal force are discussed. The phonic dissipation mechanism leads to a non-monotonic function between the friction and the load rate for the molecular bearings.

2007-03-21

26

Electrochemical characterisation of patterned carbon nanotube electrodes on silane modified silicon  

Energy Technology Data Exchange (ETDEWEB)

Previously we have used atomic force anodisation lithography, with a self-assembled monolayer of hexadecyltrichlorosilane as a resist, to pattern silicon oxide nanostructures onto a p-type silicon (1 0 0) substrate. A condensation reaction was used to immobilise carbon nanotubes with high carboxylic acid functionality directly to the silicon oxide. A further condensation reaction using this surface attached the molecule ferrocenemethanol to the bound nanotubes. These new nanostructures were used as electrodes to observe the oxidation and reduction of ferrocene. However, because the small currents measured are near the detection limits of the electrochemical system used, important electrode kinetics could not to be obtained. A scribing approach made larger regions of oxidised silicon leading to the creation of larger scale patterned arrangements of carbon nanotubes allowing measurement of important electrochemical parameters such as electrode ...

2008-07-20

27

Atomic force microscopy and surface-enhanced Raman scattering detection of DNA based on DNA-nanoparticle complexes  

Energy Technology Data Exchange (ETDEWEB)

We report a simple method for the label-free detection of double-stranded DNA using surface-enhanced Raman scattering (SERS). We prepared cetyltrimethylammonium bromide (CTAB)-capped silver nanoparticles and a DNA-nanoparticle complex by adding silver nanoparticles to {lambda}-DNA solutions. In the present study, the utilization of CTAB-capped silver nanoparticles facilitates the electrostatic interaction between DNA molecules and silver nanoparticles; at the same time, the introduction of DNA avoids adding aggregating agent for the formation of nanoparticle aggregates to obtain large enhancement of DNA, because the DNA acts as both the probe molecules and aggregating agent of Ag nanoparticles. Atomic force microscopy (AFM) studies show that the morphology of DNA-Ag nanoparticle complexes seems to be determined by the concentrations of the DNA and the nanoparticles. Surface-enhanced Raman scattering (SERS) studies show that the morphology of ...

2009-03-25

28

Gravity settling  

Science.gov (United States)

Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

1979-01-01

29

Systematic implicit solvent coarse-graining of bilayer membranes: lipid and phase transferability of the force field  

International Nuclear Information System (INIS)

We study the lipid and phase transferability of our recently developed systematically coarse-grained solvent-free membrane model. The force field was explicitly parameterized to describe a fluid 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) bilayer at 310 K with correct structure and area per lipid, while gaining at least three orders of magnitude in computational efficiency (see Wang and Deserno 2010 J. Phys. Chem. B 114 11207-20). Here, we show that exchanging CG tails, without any subsequent re-parameterization, creates reliable models of 1,2-dioleoylphosphatidylcholine (DOPC) and 1,2-dipalmitoylphosphatidylcholine (DPPC) lipids in terms of structure and area per lipid. Furthermore, all CG lipids undergo a liquid-gel transition upon cooling, with characteristics like those observed in experiments and all-atom simulations during phase transformation. These studies suggest a promising transferability of our force field ...

2010-09-01

30

Experimental and analytical studies of 4-inch pipe whip tests under PWR LOCA conditions  

International Nuclear Information System (INIS)

The purposes of the pipe rupture studies at the Japan Atomic Energy Research Institute are to perform the model tests on the pipe whip of a pipe-restraints system, to get jet impingement force and blowdown thrust force, and to establish the computational method for the analysis of these phenomena. This paper presents the experimental and analytical results of the pipe whip tests carried out under the PWR LOCA conditions using the test pipe of 4-inch diameter and the U-shaped restraints. In the tests, the gap between the test pipe and the restraints was set nearly constant and the overhang length was 250 mm, 400 mm or 650 mm. The dynamic strains and residual deformations of the test pipe and restraints, and the restraint force were measured to clarify the effects of the overhang length on the pipe whip behaviors of the pipe-restraints system. It was confirmed from the pressure data that the present pipe ...

31

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples  

Science.gov (United States)

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...

2007-03-03

32

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples  

Energy Technology Data Exchange (ETDEWEB)

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...

2007-05-15

33

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples  

International Nuclear Information System (INIS)

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...

2007-05-01

34

Stiff Stability of the Hydrogen atom in dissipative Fokker electrodynamics  

CERN Document Server

We introduce an ad-hoc electrodynamics with advanced and retarded Lienard-Wiechert interactions plus the dissipative Lorentz-Dirac self-interaction force. We study the covariant dynamical system of the electromagnetic two-body problem, i.e., the hydrogen atom. We perform the linear stability analysis of circular orbits for oscillations perpendicular to the orbital plane. In particular we study the normal modes of the linearized dynamics that have an arbitrarily large imaginary eigenvalue. These large eigenvalues are fast frequencies that introduce a fast (stiff) timescale into the dynamics. As an application, we study the phenomenon of resonant dissipation, i.e., a motion where both particles recoil together in a drifting circular orbit (a bound state), while the atom dissipates center-of-mass energy only. This balancing of the stiff dynamics is established by the existence of a quartic resonant constant that locks the ...

2005-01-01

35

Law project adopted by the Senate and authorizing the ratification of the additional protocol to the agreement between France, the European atomic energy community and the international atomic energy agency relative to the application of warranties in France; Projet de loi adopte par le Senat autorisant la ratification du protocole additionnel a l'accord entre la France, la Communaute europeenne de l'energie atomique et l'Agence internationale de l'energie atomique relatif a l'application de garanties en Franc  

Energy Technology Data Exchange (ETDEWEB)

This project of law concerns an additional protocol to the agreement of warranties signed on September 22, 1998 between France, the European atomic energy community and the IAEA. This agreement concerns the declaration of all information relative to the R and D activities linked with the fuel cycle and involving the cooperation with a foreign country non endowed with nuclear weapons. These information include the trade and processing of nuclear and non-nuclear materials and equipments devoted to nuclear reactors (pressure vessels, fuel loading/unloading systems, control rods, force and zirconium tubes, primary coolant pumps, deuterium and heavy water, nuclear-grade graphite), to fuel reprocessing plants, to isotope separation plants (gaseous diffusion, laser enrichment, plasma separation, electromagnetic enrichment), to heavy water and deuterium production plants, and to uranium conversion plants. (J.S.)

2002-10-01

36

Characterization and gas-sensing behavior of an iron oxide thin film prepared by atomic layer deposition  

International Nuclear Information System (INIS)

In this work we investigate an iron oxide thin film grown with atomic layer deposition for a gas sensor application. The objective is to characterize the structural, chemical, and electrical properties of the film, and to demonstrate its gas-sensitivity. The obtained scanning electron microscopy and atomic force microscopy results indicate that the film has a granular structure and that it has grown mainly on the glass substrate leaving the platinum electrodes uncovered. X-ray diffraction results show that iron oxide is in the #alpha#-Fe_2O_3 (hematite) phase. X-ray photoelectron spectra recorded at elevated temperature imply that the surface iron is mainly in the Fe"3"+ state and that oxygen has two chemical states: one corresponding to the lattice oxygen and the other to adsorbed oxygen species. Electric conductivity has an activation energy of 0.3-0.5 eV and almost Ohmic current-voltage dependency. When exposed to O_2 ...

2008-07-31

37

Four Forces on a Rocket - NASA  

Science.gov (United States)

On an airplane, the lift force (the aerodynamic force perpendicular to the flight direction) is used to overcome the weight. On a rocket, thrust is used in opposition ...

39

Influence of surface heat flux ratio on heat transfer augmentation in square channels with parallel, crossed, and V-shaped angled ribs  

Science.gov (United States)

The paper investigates the effect of the wall heat flux ratio on the local heat transfer augmentation in a square channel with two opposite in-line ribbed walls for Reynolds numbers from 15,000 to 80,000. The square channel composed of 10 isolated copper sections has a length-to-hydraulic diameter ratio of 20. The rib height-to-hydraulic diameter ratio is 0.0625 and the rib pitch-to-height ratio equals 10. Six ribbed side to smooth side wall heat flux ratios are studied for four rib orientations. The results show that the ribbed side wall heat transfer augmentation increases with increasing ribbed side to smooth side wall heat flux ratios, but the reverse is true for the smooth side wall heat transfer augmentation. The average heat transfer augmentation of the ribbed side and smooth side wall decreases slightly with increasing wall heat flux ratios. The effect of wall heat flux ratio reduces with increasing Reynolds numbers. The 60-deg V-shaped rib and 60-deg ...

1992-10-01

40

Effect of V-shaped defects on structural and optical properties of AlGaN/InGaN multiple quantum wells  

International Nuclear Information System (INIS)

We have investigated the correlation between V-shaped defect formation and the optical properties of AlGaN/(In)GaN multiple quantum wells (MQWs) grown under different growth conditions and then demonstrated the characteristics of fabricated ultraviolet (UV) light emitting diodes (LEDs). From the temperature-dependent photoluminescence (PL) measurement, the internal quantum efficiency for 300 K was obtained as 43.6% for a sample with a low density of V-defects in a MQW and 13.7% for a sample with a high density of V-defects. The carrier lifetime based on the time resolved PL measurement at room temperature was 0.32 ns for a sample with a high density of V-defects and 1.26 ns for a sample with a low density of V-defects. And we also found that the density of V-defects affected the external quantum efficiency and wall plug efficiency of the fabricated UV LEDs. (fast track communication)

2008-07-07

41

Effective-index modeling of channel plasmon polaritons  

Science.gov (United States)

Effective-index approach is applied for modeling of channel plasmon polaritons (CPPs) propagating in rectangular grooves (trenches) and triangular (V-shaped) grooves in gold, accounting for the main features of CPP guiding and elucidating its underlying physics. The effective indexes of CPP modes along with the corresponding propagation lengths are calculated for different configurations and wavelengths while varying the groove depth. The results obtained allow one to identify the parameter range for realizing the single-mode CPP guiding featuring subwavelength confinement and moderate propagation loss at telecom wavelengths.

2006-10-01

42

Bend loss for channel plasmon polaritons  

Science.gov (United States)

Using near-field optical microscopy, the authors investigate propagation of channel plasmon polaritons excited in the wavelength range of 1425-1640 nm along smoothly bent and split V-shaped grooves milled in a gold film. We find that for 0.6-?m-wide and 1.1-?m-deep grooves bent with the smallest curvature radius of ?0.83 ?m, the double bend (for S bends) and splitting (for Y splitters) losses decrease for longer wavelengths approaching (in the wavelength range of 1600-1640 nm) the levels of ~0 and 0.5 dB, respectively.

2006-10-01

43

Shape evolution of nanostructures by thermal and ion beam processing. Modeling and atomistic simulations  

International Nuclear Information System (INIS)

Single-crystalline nanostructures often exhibit gradients of surface (and/or interface) curvature that emerge from fabrication and growth processes or from thermal fluctuations. Thus, the system-inherent capillary force can initiate morphological transformations during further processing steps or during operation at elevated temperature. Therefore and because of the ongoing miniaturization of functional structures which causes a general rise in surface-to-volume ratios, solid-state capillary phenomena will become increasingly important: On the one hand diffusion-mediated capillary processes can be of practical use in view of non-conventional nanostructure fabrication methods based on self-organization mechanisms, on the other hand they can destroy the integrity of nanostructures which can go along with the failure of functionality. Additionally, capillarity-induced shape transformations are effected and can thereby be controlled by applied fields and ...

2009-05-12

44

Variational approach to nuclear matter  

International Nuclear Information System (INIS)

We calculated the energies of asymmetric nuclear matter at zero and finite temperatures with the cluster variational method. At zero temperature, the expectation value of the two-body Hamiltonian composed of the kinetic energies and the AV18 two-body forces is calculated with the Jastrow wave function in the two-body cluster approximation. The obtained two-body energy is in good agreement with the result with the Fermi Hypernetted Chain (FHNC) calculation by Akmal et al. The energy caused by the UIX three-body forces is treated somewhat phenomenologically so that the total energy reproduces the empirical saturation point. Furthermore, the parameters included in the three-body energy are readjusted so that the Thomas-Fermi (TF) calculations with use of the obtained energy of nuclear matter reproduce the gross feature of the experimental data on atomic nuclei. The nuclear species in the neutron star crust obtained by the TF ...

2010-12-01

45

The upgrade of nuclear material accounting system at KAERI  

International Nuclear Information System (INIS)

The agreement between the government of Republic Of Korea (ROK) and the IAEA for the application of safeguards was signed and entered into force in 1975. The Additional Protocol (AP) to the Safeguards Agreement between the ROK and the IAEA was signed in 1999 and entered into force on 19 February 2004. Also, Implementation of Integrated Safeguards (IS) was started on 1 July, 2008 after a draw of the broader conclusion. The IAEA provides 2 hours notification for Random Interim Inspection (RII) under IS. For RII, the facility has to prepare the inspection documents in a short time. Therefore, KAERI (Korea Atomic Energy Research Institute) developed a new computerized nuclear material accounting system named KASIS (KAERI Safeguards Information treatment System) to treat the data by on-line for RII. For the efficient IS implementation, KAERI has a plan to upgrade the system to reflect the accounting approaches or reporting ...

2010-10-01

46

Transmission electron microscopy characterisation of permalloy elements fabricated by focussed ion beam lithography  

International Nuclear Information System (INIS)

20 nm thick permalloy elements, with dimensions of 500 x 500 nm"2 and 1000 x 200 nm"2, have been fabricated on 50 nm thick silicon nitride substrate by milling using a focussed ion beam (FIB) microscope. The dose of ion beam used for the milling was varied in order to achieve the best definition for the milled areas. The FIB milled elements were characterised physically by atomic force microscopy (AFM) and bright field transmission electron microscopy (TEM) and magnetically by Fresnel imaging on a TEM modified for magnetic imaging. The FIB milled elements were found to have a more irregular edge and lower magnetic fields for events such as vortex annihilation when compared to elements of the same dimensions fabricated by conventional electron beam microscopy (EBL).

2006-02-22

47

The study of the ion beam induced swelling in crystalline germanium irradiated by a 30 keV Ga"+ focused ion beam  

International Nuclear Information System (INIS)

The effect of swelling of crystalline Ge irradiated at room temperature with 30 keV Ga"+ focused ion beam (FIB) was studied by means of in situ FIB imaging, atomic force microscopy (AFM) and transmission electron microscopy (TEM). The swelling occurred in the surface region of amorphous damage layer which was formed during ion irradiation. The degree of swelling reaches values up to 10 times for an implantation dose of #approx#10"1"7 ions/cm"2. Cross-secitonal TEM examination showed that the swelling is due to formation of a porous layer with a honeycomb structure. (author). 8 refs., 4 figs.

2005-11-20

48

Synthesis and investigation of #pi#-conjugated azomethine self-assembled multilayers by layer-by-layer growth  

International Nuclear Information System (INIS)

Layer-by-layer formation for #pi#-conjugated azomethine multilayers bonded on substrates was investigated. The multilayers were synthesized using ethanol (EtOH) and dichloromethane (DCM) as reaction solvents. The multilayer characteristics were analyzed using UV-vis absorption spectroscopy, ellipsometric thickness, and atomic force microscopy. The absorption spectra and ellipsometric thicknesses of multilayers formed using EtOH and DCM were compared. The results indicate that EtOH is more suitable than DCM for such layer-by-layer formation. In addition, bandgaps estimated from the absorption edge of multilayers were investigated. The results indicate that the bandgap decreases as the number of benzene rings contained in the molecular chain of the multilayer increases. Also, a multilayer with four benzene rings bonded on a substrate had a bandgap close to that of a polymer with a similar chemical structure.

2010-07-01

49

Surface modification and characterization for dispersion stability of inorganic nanometer-scaled particles in liquid media  

International Nuclear Information System (INIS)

Inorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM). Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect of surface ...

2010-08-01

50

Processing and characterization of chitosan microspheres to be used as templates for layer-by-layer assembly  

British Library Electronic Table of Contents (United Kingdom)

Chitosan (Ch) microspheres have been developed by precipitation method, cross-linked with glutaraldehyde and used as a template for layer-by-layer (LBL) deposition of two natural polyelectrolytes. Using a LBL methodology, Ch microspheres were alternately coated with hyaluronic acid (HA) and Ch under mild conditions. The roughness of the Ch-based crosslinked microspheres was characterized by atomic force microscopy (AFM). Morphological characterization was performed by environmental scanning electron microscopy (ESEM), scanning electron microscopy (SEM) and stereolight microscopy. The swelling behaviour of the microspheres demonstrated that the ones with more bilayers presented the highest water uptake and the uncoated cross-linked Ch microspheres showed the lowest uptake capability. Micros...

2010-01-01

51

Preparation and photocatalytic property of pyrochlore Bi2Ti2O7 and (Bi, La) 2Ti2O7 films  

British Library Electronic Table of Contents (United Kingdom)

Dopant-free Bi2Ti2O7 thin films with pyrochlore structure and La-doped bismuth titanate thin films have been fabricated by means of chemical solution decomposition, and characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy and UV?Vis spectrophotometry in this study. Their photocatalytic activities have been evaluated by photodegrading methyl orange solution, and the optimum processing parameters for the highest photocatalytic activity have been found. Moreover, the effects of La-doping on the phase transformation and the photocalalytic activity have been studied. It has been deduced from the experiment result that substituted La3+ ions can act as a stabilizer of Aurivillus phase BLT and a grain?growth inhibitor in BLT thin films.

2008-01-01

52

Preparation and Characterization of a Novel Polyamide Charged Mosaic Membrane  

British Library Electronic Table of Contents (United Kingdom)

A novel composite charged mosaic membrane (CCMM) was prepared via interfacial polymerization (IP) of polyamine [poly(epichlorohydrin amine)] and trimesoyl chloride (TMC) on the polyethersulfone (PES) support. Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and water contact angle analysis were applied to characterize the resulted CCMM. The FT-IR spectrum indicates that TMC reacts sufficiently with polyamine. ESEM and AFM pictures show that the IP process produces a dense selective layer on the support membrane. The water contact angle of the CCMM is smaller than that of the substrate membrane because of the cross-linked hydrophilic polyamine network. Several factors affecting the IP reaction and the performan...

2010-01-01

53

Positron annihilation study on thin-film composite pervaporation membranes: Correlation between polyamide fine structure and different interfacial polymerization conditions  

British Library Electronic Table of Contents (United Kingdom)

To investigate the variation in the fine structure of polyamide thin-film composite (TFC) membranes prepared via two different interfacial polymerization conditions (IP-I and IP-II), experiments on Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), water contact angle, and positron annihilation spectroscopy (PAS) coupled to a slow positron beam were conducted. Polyamide TFC membranes were prepared via the interfacial polymerization reaction between triethylenetetramine (TETA) and trimesoyl chloride (TMC) on the surface of a modified polyacrylonitrile (mPAN) membrane. Compared with the polyamide TFC membrane prepared via IP-I, the polyamide layer prepared via IP-II showed a shorter S plateau length (thinner thickness), a higher o-Ps intensity I3 value (higher free-volume con...

2010-01-01

54

New concept on lower exhaust emission of diesel engine  

Energy Technology Data Exchange (ETDEWEB)

One of the countermeasures for exhaust emissions from a diesel engine, especially, DI diesel engine, is the use of a super high pressure injection system with a small hole diameter. However, the system needs greater driving force than that with normal injection pressure,and its demerit is an increase in NO{sub x}, although soot decreases. The authors propose a new concept, the simultaneous reduction of NO{sub x} and soot. The concept is that the utilization of flash boiling phenomenon in a diesel engine. The phenomenon can be realized by use of the injection of fuel oil with CO{sub 2} gas dissolved. Flash boiling facilities the distinguished atomization of fuel oil and CO{sub 2} gas contributes to the internal EGR (Exhaust Gas Recirculation) during combustion. Fundamental information on the characteristics of a flash boiling spray of n-tridecane with CO{sub 2} gas dissolved is described in this paper, as a first step.

1995-12-31

55

Nanostructuring and hardening of LiF crystals irradiated with 3?15 MeV Au ions  

British Library Electronic Table of Contents (United Kingdom)

Modifications of the structure and mechanical properties in LiF crystals irradiated with MeV-energy Au ions have been studied using nanoindentation, atomic force microscopy and optical spectroscopy. The nanostructuring of crystals under a high-fluence irradiation (above 1013 ions/cm2)?was?observed. Nanoindentation tests show a strong ion-induced increase of hardness (up?to 150?200%), which is related to the high volume concentration of complex color centers, defect aggregates, dislocation loops and grain boundaries acting as strong barriers for dislocations. From the?depth profiling of the hardness and energy loss it follows that both nuclear and electronic stopping mechanisms of MeV Au ions contribute to the creation of damage and hardening. Whereas the electronic stopping is dominating i...

2011-01-01

56

Nanoparticle formation during laser ablation of metals at different pressures of surrounding noble gases  

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-15

57

Investigating the effect of an arterial hypertension drug on the structural properties of plasma protein  

British Library Electronic Table of Contents (United Kingdom)

Propanolol is a betablocker drug used in the treatment of arterial hypertension related diseases. In order to achieve an optimal performance of this drug it is important to consider the possible interactions of propanolol with plasma proteins. In this work, we have used several experimental techniques to characterise the effect of addition of the betablocker propanolol on the properties of bovine plasma fibrinogen (FB). Differential scanning calorimeter (DSC), circular dichroism (CD), dynamic light scattering (DLS), surface tension techniques and atomic force microscopy (AFM) measurements have been combined to carry out a detailed physicochemical and surface characterization of the mixed system. As a result, DSC measurements show that propranolol can play two opposite roles, either acting ...

2011-01-01

58

Influence of sputtering parameters and nitrogen on the microstructure of chromium nitride thin films deposited on steel substrate by direct-current reactive magnetron sputtering  

International Nuclear Information System (INIS)

Chromium nitride thin films were deposited on SA-304 stainless steel substrates by using direct-current reactive magnetron sputtering. The influence of process conditions such as nitrogen content in the fed gas, substrate temperature, and different sputtering gases on microstructural characteristics of the films was investigated. The films showed (200) preferred orientation at low nitrogen content (< 30%) in the fed gas. The formation of Cr_2N and CrN phases was observed when 30% and 40% N_2 were used, with a balance of Ar, respectively. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the morphology and surface topography of the thin films, respectively. Microhardness tests showed a maximum hardness of 16.95 GPa for the 30% nitrogen content.

2010-08-02

59

Graphene-Pt nanocomposite for nonenzymatic detection of hydrogen peroxide with enhanced sensitivity  

British Library Electronic Table of Contents (United Kingdom)

A sensitive hydrogen peroxide (H2O2) sensor was fabricated based on graphene-Pt (GN-Pt) nanocomposite. The GN-Pt was synthesized by photochemical reduction of K2PtCl4 on GNs, and characterized by atomic force microscope (AFM), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy (EDS). Electrochemical investigations indicated that the GN-Pt exhibited a high peak current and low overpotential towards the reduction of H2O2. The GN-Pt modified glass carbon electrode displayed a wide linear range (2-710mM), low limit of detection (0.5mM) and good selectivity for detection of H2O2 with a much higher sensitivity than that of Pt nanoparticles or graphene modified electrode.

2011-01-01

60

Formation of Cu2O Quantum Dots on SrTiO3 (100): Self-Assembly and Directed Self-Assembly  

Energy Technology Data Exchange (ETDEWEB)

Nanoscale islands of Cu2O have been synthesized on single-crystal SrTiO3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (OPA-MBE). Island growth location has been controlled by using an ex-situ Ga+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. Analysis of Cu2O dot growth on unmodified substrate regions revealed an evolution of dot size and array density. Atomic force microscopy studies show that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of islands. Islands initially formed in the FIB-generated surface topography and filled those features before nucleating on neighboring unmodified surface regions.

2006-11-09

61

Focused-ion-beam directed self-assembly of Cu_2O islands on SrTiO_3(100)  

International Nuclear Information System (INIS)

Nanoscale islands of Cu_2O have been synthesized on single-crystal SrTiO_3 (100) substrates using oxygen plasma-assisted molecular-beam epitaxy (MBE). Island growth location has been controlled by using an ex situ Ga"+ focused ion beam (FIB) to modify the growth surface in discrete locations prior to island synthesis. The FIB modifications have generated surface topography with lateral dimensions of 150-200 nm. Ex situ atomic force microscopy study after island growth reveals that certain FIB substrate modification and MBE growth condition combinations lead to directed self-assembly of metal oxide islands at the edges of the FIB modified zones.

2004-06-21

62

Environmental, scanning electron and optical microscope image analysis software for determining volume and occupied area of solid-state fermentation fungal cultures  

British Library Electronic Table of Contents (United Kingdom)

Abstract Here we propose a software for the estimation of the occupied area and volume of fungal cultures. This software was developed using a Matlab platform and allows analysis of high-definition images from optical, electronic or atomic force microscopes. In a first step, a single hypha grown on potato dextrose agar was monitored using optical microscopy to estimate the change in occupied area and volume. Weight measurements were carried out to compare them with the estimated volume, revealing a slight difference of less than 1.5%. Similarly, samples from two different solid-state fermentation cultures were analyzed using images from a scanning electron microscope (SEM) and an environmental SEM (ESEM). Occupied area and volume were calculated for both samples, and the results obtained w...

2011-01-01

63

Electrodeposition and characterization of Ni-Co/SiC nanocomposite coatings  

British Library Electronic Table of Contents (United Kingdom)

Ni-Co/SiC nanocomposite coatings were electrodeposited in a modified watt type of Ni-Co bath containing 20nm SiC particles to be codeposited. Potentiodynamic polarization tests were conducted to study the effect of the SiC particulates on the electrodeposition of Ni and Co. Scanning electron microscopy was used to assess the morphology of the Ni-Co alloy and Ni-Co/SiC nanocomposite coatings. The distribution of the particulates in the matrix was considered by means of transmission electron microscopy. Applying nanomechanical testing instruments coupled to atomic force microscopy, mechanical properties of the alloy and composite coatings were studied and compared. The presence of 11vol.% SiC in the Ni-Co matrix increased hardness more than 60%. The average depth of scratch in the mentioned ...

2011-01-01

64

Electrochemical method for the synthesis of silver nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

The article deals with a novel electrochemical method of preparing long-lived silver nanoparticles suspended in aqueous solution as well as silver powders. The method does not involve the use of any chemical stabilising agents. The morphology of the silver nanoparticles obtained was studied using transmission electron microscopy, scanning electron microscopy, atomic force microscopy and dynamic light scattering measurements. Silver nanoparticles suspended in water solution that were produced by the present technique are nearly spherical and their size distribution lies in the range of 2 to 20 nm, the average size being about 7 nm. Silver nanoparticles synthesised by the proposed method were sufficiently stable for more than 7 years even under ambient conditions. Silver crystal growth on the surface of the cathode in the electrochemical process used was shown to result in micron-sized structures consisting of agglomerated silver nanoparticles ...

2009-07-15

65

Design and control of six degree-of-freedom active vibration isolation table.  

Science.gov (United States)

A six-axis active vibration isolation system (AVIS) is designed by using the direct driven guide and ball contact mechanisms in order to have no cross-coupling between actuators. The point contact configuration gives an advantage of having an easy assembly of eight voice coil actuators to an upper and a base plate. A voice coil actuator is used since it can provide a large displacement and sufficient bandwidth required for vibration control. The AVIS is controlled considering the effect of flexible vibration mode in the upper plate and velocity sensor dynamics. A loop shaping technique and phase margin condition are applied to design a vibration controller. The performances of the AVIS are investigated in the frequency domain and finally validated by comparing with the passive isolation system. The scanning profiles of the specimen are compared together by using the atomic force microscope. The robustness of the AVIS is verified by showing the ...

2010-03-01

66

Decree of the Czechoslovak Atomic Energy Commission No. 436/1990 on quality assurance of selected facilities with respect to nuclear safety of nuclear facilities  

International Nuclear Information System (INIS)

The Decree specifies basic quality assurance requirements applicable to machines, their parts and materials, civil engineering structures, means for automated control of technological processes including hardware and software, and electricity supply systems related to nuclear safety of nuclear facilities, and stipulates binding procedures for the implementation of technical and organizational provisions associated with the quality of selected equipment to ensure nuclear safety of nuclear facilities. Safety classes are defined for selected equipment. Requirements laid on safety assurance documentation are specified, and requirements placed on safety assurance programmes, their preparation, finalization and approval are defined. Quality assurance requirements are also specified with respect to the designing, manufacture, construction, operation, repair, modification and decommissioning of nuclear facilities. The Decree entered into force on 1 December 1990. (J.B.).

1995-02-01

67

Creation of nitrogen-vacancy centres in diamond with high resolution  

International Nuclear Information System (INIS)

Nowadays, diamond and the nitrogen-vacancy (NV) colour centres constitute the best solid-state system in view of quantum-computing applications. It has also been shown recently that single NV centres could be used as nanoscale magnetic sensors. Such applications require the creation of single NV centres with very high resolution and with a high efficiency. The nano-implanter at the university of Bochum provides low energy nitrogen ions which can be implanted through a hole pierced in the tip of an atomic force microscope. Ultrapure diamond samples have been implanted with spot sizes of 50nm and less. Stimulated Emission Depletion (STED) microscopy has been used to characterise and resolve the implanted spots.

2010-03-21

68

Binary pseudo-random grating as a standard test surface formeasurement of modulation transfer function of interferometricmicroscopes  

Energy Technology Data Exchange (ETDEWEB)

The task of designing high performance X-ray optical systemsrequires the development of sophisticated X-ray scattering calculationsbased on rigorous information about the optics. One of the mostinsightful approaches to these calculations is based on the powerspectral density (PSD) distribution of the surface height. The majorproblem of measurement of a PSD distribution with an interferometricand/or atomic force microscope arises due to the unknown ModulationTransfer Function (MTF) of the instruments. The MTF characterizes theperturbation of the PSD distribution at higher spatial frequencies. Here,we describe a new method and dedicated test surfaces for calibration ofthe MTF of a microscope. The method is based on use of a speciallydesigned Binary Pseudo-random (BPR) grating. Comparison of atheoretically calculated PSD spectrum of a BPR grating with a spectrummeasured with the grating provides the desired calibration of theinstrumental MTF. The ...

2007-07-25

69

Beryllium coating on JET Inconel tiles  

International Nuclear Information System (INIS)

Full text: Institute for Nuclear Research, Pitesti-Mioveni, Romania in direct cooperation with the National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest studied and prepared for coating more than 1000 tiles made of Inconel with 7-9 #mu#m of beryllium for nuclear fusion applications at JET, Culham, UK. The principles of manufacturing processes using thermal evaporation and plasma ignited in pure metal vapors as well as by Thermionic Vacuum Arc (TVA) method and the properties of the Ni and Be coatings are presented. The prepared beryllium layers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy. (authors)

2009-10-12

70

AFM Imaging of SWI/SNF action: mapping the nucleosome remodeling and sliding  

CERN Document Server

We propose a combined experimental (Atomic Force Microscopy) and theoretical study of the structural and dynamical properties of nucleosomes. In contrast to biochemical approaches, this method allows to determine simultaneously the DNA complexed length distribution and nucleosome position in various contexts. First, we show that differences in the nucleo-proteic structure observed between conventional H2A and H2A.Bbd variant nucleosomes induce quantitative changes in the in the length distribution of DNA complexed with histones. Then, the sliding action of remodeling complex SWI/SNF is characterized through the evolution of the nucleosome position and wrapped DNA length mapping. Using a linear energetic model for the distribution of DNA complexed length, we extract the net wrapping energy of DNA onto the histone octamer, and compare it to previous studies.

2007-01-01

71

Experiences with applications of PSA results for optimization/revision of technical specifications for operation of nuclear power plants  

International Nuclear Information System (INIS)

Over the past few years, NPCIL has performed comprehensive Level-1 Probabilistic Safety Assessment (PSA) for a 220 MWe Pressurised Heavy Water Reactor (PHWR) at Kakrapar Atomic Power Station (KAPS) and for the first 540 MWe PHWR at Tarapur Atomic Power Project (TAPP- 3 and 4). The major objective of these PSAs was to present an integrated picture of the safety of the plant to identify and understand key plant vulnerabilities. As a result of the availability of these PSAs, there is a desire to use them to operate the plants in the most efficient manner practicable. In recent years, the operation of Indian Nuclear Power Plants has been characterized by improved availability/capacity factors and reduced forced outages. Frequency of planned outages is also being reduced. In order to achieve this, the PSAs are now being used as an engineering tool for optimization of Technical Specifications with regard to Allowed Outage Time ...

2005-12-01

72

Impediments to the Creation of a Specialized Force for ...  

Science.gov (United States)

Impediments to the Creation of a Specialized ... 4. TITLE AND SUBTITLE Impediments to the Creation of a Specialized Force for Stability Operations ...

2008-12-03

73

32 CFR 813.4 - Combat camera operations.  

Science.gov (United States)

...COMCAM forces document Air Force and air component activities...supported unified command or joint task force commander, through the...Force COMCAM forces in a joint environment. If an...share of Unified Command headquarters COMCAM and visual...

2010-07-01

74

Basics of Ion Scattering in Nanoscale Materials  

Science.gov (United States)

Energetic ions interact with materials by collisions with the nuclei and electrons of the atoms that make up the material. In these collisions energy and momentum is transferred from the projectile particle which is a moving atom or ion, to the target particles (atomic nucleus or electron). Each collision leads to a slowing down of the moving projectile and also a deflection of the trajectory which gives rise to the term scattering which is often used synonymously to describe the energy transfer process. In this chapter, we introduce from an experimental viewpoint the underlying theory for interaction of ions for analysis and modification of nanometer scale materials. A more detailed theoretical overview of the topic can be found in the recent monographs by Sigmund. Detailed derivations of the formulae introduced will not be given here but can be found in standard texts that are indicated by references. The treatment here ...

2010-01-01

75

Study of ytterbium doping effects on structural, mechanical and opto-thermal properties of sprayed ZnO thin films using the Boubaker Polynomials Expansion Scheme (BPES)  

Energy Technology Data Exchange (ETDEWEB)

In this work, ZnO thin films have been grown on glass substrates by using a solution of propanol (C{sub 3}H{sub 8}O), water (H{sub 2}O) and zinc acetate (Z{sub n}(CH{sub 3}CO{sub 2}){sub 2}) in acidified medium (pH 5). The obtained films were n doped with ytterbium (Yb) at the rates of 100, 200 and 300 ppm. The structural features of the doped films were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. XRD analysis shows a strong (0 0 2) X-ray diffraction line for increasing Yb-doping amounts. This c-axis preferential orientation of ZnO crystallites is naturally required to use this oxide as transparent conductor in optoelectronic applications. Atomic force microscopy (AFM) analysis shows an enhancement in the surface roughness of the doped ZnO:Yb thin films. Optical measurements were performed in 300-1800 nm domain via transmittance T(lambda) and ...

2009-10-19

76

Study of ytterbium doping effects on structural, mechanical and opto-thermal properties of sprayed ZnO thin films using the Boubaker Polynomials Expansion Scheme (BPES)  

International Nuclear Information System (INIS)

In this work, ZnO thin films have been grown on glass substrates by using a solution of propanol (C3H8O), water (H2O) and zinc acetate (Zn(CH3CO2)2) in acidified medium (pH 5). The obtained films were n doped with ytterbium (Yb) at the rates of 100, 200 and 300 ppm. The structural features of the doped films were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. XRD analysis shows a strong (0 0 2) X-ray diffraction line for increasing Yb-doping amounts. This c-axis preferential orientation of ZnO crystallites is naturally required to use this oxide as transparent conductor in optoelectronic applications. Atomic force microscopy (AFM) analysis shows an enhancement in the surface roughness of the doped ZnO:Yb thin films. Optical measurements were performed in 300-1800 nm domain via transmittance T(?) and reflectance R(?) spectra. Conjoint optical and thermal ...

2009-10-19

77

Investigation of sulfonated aromatic compound (SAC) modification to nylon film. 2. Study of SAC sorption isotherm and atomic force microscopic characterization of nylon surfaces  

Energy Technology Data Exchange (ETDEWEB)

Nylon 6 and nylon 66 films have been treated with aqueous sulfonated aromatic compound (SAC) solutions at concentrations ranging from 0.005 to 1.0 wt%. SAC uptakes at different treatment concentrations were measured and found to follow a BET isotherm. The surface morphologies of nylon film samples, including the original and SAC-treated films, have been characterized by atomic force microscopy (AFM). For untreated nylon 6 and nylon 66 films, AFM images show a randomly distributed fibrillar surface structure. Characteristic widths of fibrils in the nylon 66 and 6 films were 150-225 and 75-150 nm, respectively. For SAC-treated nylon films, the AFM images revealed that the surfaces of the films became covered with nodule-like features having a diameter range of 25-60 nm. AFM analysis provides evidence that SAC treatment deposited a surface coating on nylon films. AFM images of SAC-treated nylon films suggest a mechanism for stain resistance in ...

1995-08-01

78

A Flow Stress Formulation of Magnesium Alloy at Elevated Temperature  

International Nuclear Information System (INIS)

Dynamic recrystallization (DRX) is the main softening mechanism of magnesium alloy AZ31B in hot deformation. Theoretically, in the flow rule the atomic diffusibility and the driving force of dislocation migration are dependent on the temperature, and the dislocation density and the cumulation of grain boundary energy are dependent on the strain rate. The peak stress will appear when the flow driving force and resistance force reach a balance, after which the stress descending will take place due to recrystallization fraction. Since the DRX is a thermally activated process, the recrystallized volume fraction can be regarded as the function of strain through Avrami equation. Based on this idea, the paper proposes a new constitutive model characterizing dynamic recrystallization for magnesium alloy AZ31B. The model is described by a peak stress and a strain softening rate, in which the peak stress depends ...

2007-05-17

79

Numerical calculation of the Casimir forces between a gold sphere and a nanocomposite sheet  

International Nuclear Information System (INIS)

The repulsive Casimir force is expected as a force which enables to levitate small objects such as machine parts used in Micro Electro Mechanical Systems (MEMS), and superlubricity in MEMS may be realized by this levitation. We study the Casimir force between a gold sphere and a nanocomposite sheet containing many nickel nanoparticles. In particular, we focus on the dependence of the Casimir force on the separation between the gold sphere and the surface of the nanocomposite sheet. The Casimir force changes from the attractive force to the repulsive force as the separation increases. The strength of the repulsive force is, however, too small to levitate MEMS parts.

2010-11-01

80

Third World Arms Proliferation and Forced Entry Operations ...  

Science.gov (United States)

... Third World Arms Proliferation and Forced Entry Operations: Circumstances Demanding the Creation of a Standing Joint Task Force Headquarters. ...

1990-03-29

81

The Theater JFACC Construct: Creating Disunity of Command ...  

Science.gov (United States)

... WHS- Washington Headquarters Service ... paper will advocate assignment of a Commander, Air Force Forces for all Joint Task Forces conducting ...

2009-04-01

82

No. 292-M:11/18/94:Tandem Thrust 95, a Joint Task Force Fie  

Science.gov (United States)

... The mission of Tandem Thrust is to employ a joint task force headquarters and appropriate forces in a realistic training exercise. ...

83

Force Required to Detach Conidia of Helminthosporium maydis  

UK PubMed Central (United Kingdom)

The force required to break the conidium-conidiophore attachment in Helminthosporium maydis was measured by centrifugation and by a small jet of air. The force which removed half the...Full Text Available

1975-01-01

84

Defense.gov News Article: Task Force Prepares for Horn of ...  

Science.gov (United States)

... After the task force deploys, Joint Forces Command interacts ... and what needs tweaking to better prepare future headquarters staffs, Mungus ...

85

Congressional Oversight of Intelligence: Current Structure and ...  

Science.gov (United States)

... 4 Joint Committee on Atomic Energy as a Model . . . . . ... Joint Committee on Atomic Energy as a Model ...

2007-02-15

87

Forming Standing Joint Special Operations Task Force Headquarters.  

Science.gov (United States)

Special Operations Forces (SOF) within a Joint Task Force are controlled by a Joint Special Operations Task Force (JSOTF). Presently, JSOTF headquarters are formed around the core of the Theater Special Operations Command (TSOC), a service SOF headquarter...

2003-01-01

88

Mechanical stability of the diamond-like carbon film on nitinol vascular stents under cyclic loading  

Energy Technology Data Exchange (ETDEWEB)

The mechanical stability of diamond-like carbon (DLC) films coated on nitinol vascular stents was investigated under cyclic loading condition by employing a stent crimping system. DLC films were coated on the vascular stent of a three dimensional structure by using a hybrid ion beam system with rotating jig. The cracking or delamination of the DLC coating occurred dominantly near the hinge connecting the V-shaped segments of the stent where the maximum strain was induced by a cyclic loading of contraction and extension. However the failures were significantly suppressed as the amorphous Si (a-Si) buffer layer thickness increased. Interfacial adhesion strength was estimated from the spalled crack size in the DLC coating for various values of the a-Si buffer layer thickness.

2008-12-01

89

Use of Computer Vision and Force Sensors for Tight ...  

Science.gov (United States)

... Accession Number : ADD811953. Title : Use of Computer Vision and Force Sensors for Tight Tolerance Assembly. Descriptive ...

1993-05-01

90

The Future of Airborne Forces in the Objective Force  

Science.gov (United States)

... operations. Of these two divisions, only the paratroopers of the 82nd Airborne Division can conduct a strategic forcible entry into a ...

2003-04-07

91

Lifting the Fog of Corporate Information Management  

Science.gov (United States)

... forces. These small forces must have the same information management capabilities as are currently 32 Page 40. available ...

1993-04-01

92

From Service Operational Headquarters to Joint Task Force ...  

Science.gov (United States)

... directed the transformation of designated Service operational headquarters into effective and scalable Joint Task Force headquarters capable of ...

2007-04-27

93

Forming Standing Joint Special Operations Task Force ...  

Science.gov (United States)

... THE STANDING JSOTF HEADQUARTERS IN A STANDING JOINT TASK FORCE HEADQUARTERS OR COMBATANT COMMAND ...

2003-04-07

94

Force Protection and Mission Accomplishment in Bosnia and ...  

Science.gov (United States)

... Khobar Towers bombing in three ways. The first was to revaluate the force posture in the Arabian Gulf region. This led to ...

2011-05-13

95

Vibration signature analysis of AFM images  

Energy Technology Data Exchange (ETDEWEB)

Vibration signature analysis has been commonly used for the machine condition monitoring and the control of errors. However, it has been rarely employed for the analysis of the precision instruments such as an atomic force microscope (AFM). In this work, an AFM was used to collect vibration data from a sample positioning stage under different suspension and support conditions. Certain structural characteristics of the sample positioning stage show up as a result of the vibration signature analysis of the surface height images measured using an AFM. It is important to understand these vibration characteristics in order to reduce vibrational uncertainty, improve the damping and structural design, and to eliminate the imaging imperfections. The choice of method applied for vibration analysis may affect the results. Two methods, the data dependent systems (DDS) analysis and the Welch`s periodogram averaging method were investigated for application ...

1995-12-31

96

Turnover of texture in low rate sputter-deposited nanocrystalline molybdenum films  

International Nuclear Information System (INIS)

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

1997-04-04

97

Topics in axion and neutrino physics, time reversal violation, and Higgs detection  

Energy Technology Data Exchange (ETDEWEB)

A number of systems which can elucidate physics beyond the standard model are investigated. The production of axions by a network of cosmic strings in the early universe is calculated. This allows an upper bound to be placed on the axion decay constant, and provides the preferred Peccei-Quinn symmetry breaking scale for axions to make up the dark matter of the universe. Models of neutrino mass arising from strong interactions are investigated. These models possess a massless up quark, thereby solving the strong CP problem. A systematic analysis of the contributions to time reversal violating atomic and molecular electric dipole moments is presented. Specific contributions from the supersymmetric standard model are calculated. The contributions arising from the QCD vacuum angle are also discussed. Prospects for detecting the axion by its long range coherent force are related to measurable electron dipole moments. A method for measuring neutrino ...

1993-12-31

98

Topics in axion and neutrino physics, time reversal violation, and Higgs detection  

International Nuclear Information System (INIS)

A number of systems which can elucidate physics beyond the standard model are investigated. The production of axions by a network of cosmic strings in the early universe is calculated. This allows an upper bound to be placed on the axion decay constant, and provides the preferred Peccei-Quinn symmetry breaking scale for axions to make up the dark matter of the universe. Models of neutrino mass arising from strong interactions are investigated. These models possess a massless up quark, thereby solving the strong CP problem. A systematic analysis of the contributions to time reversal violating atomic and molecular electric dipole moments is presented. Specific contributions from the supersymmetric standard model are calculated. The contributions arising from the QCD vacuum angle are also discussed. Prospects for detecting the axion by its long range coherent force are related to measurable electron dipole moments. A method for measuring neutrino ...

99

Surface morphology of thin lysozyme films produced by matrix-assisted pulsed laser evaporation (MAPLE)  

Energy Technology Data Exchange (ETDEWEB)

Thin films of the protein, lysozyme, have been deposited by the matrix-assisted pulsed laser evaporation (MAPLE) technique. Frozen targets of 0.3-1.0 wt.% lysozyme dissolved in ultrapure water were irradiated by laser light at 355 nm with a fluence of 2 J/cm{sup 2}. The surface quality of the thin lysozyme films of different thickness deposited on 7 mm x 7 mm Si-<1 0 0>-wafers was investigated with scanning electron microscopy and atomic force microscopy. Already at comparatively low thickness, {approx}20 nm, the substrate is covered by intact lysozyme molecules and fragments. The concentration of lysozyme in the ice matrix apparently does not play any significant role for the morphology of the film. The morphology obtained with MAPLE has been compared with results for direct laser irradiation of a pressed lysozyme sample (i.e. pulsed laser deposition (PLD))

2007-12-15

100

Submicron-scale patterns on ferromagnetic-antiferromagnetic Fe/NiO layers by focused ion beam (FIB) milling  

Energy Technology Data Exchange (ETDEWEB)

With the aim of studying the magnetic properties of reduced-dimensionality magnetic systems we have patterned 250 nm- and 500 nm-size square elements on Fe/NiO layers by 30 keV Ga{sup +} focused ion beam (FIB) milling, varying beam current and pixel dwell time. By high resolution scanning electron microscope (SEM) imaging and atomic force microscopy (AFM) analysis we found that island size decreases from the nominal value by increasing the beam current and features sharpness improves on increasing the dwell time. The top surface of the isolated features has a pronounced edge bending which may be as high as 9 nm with respect to the flat inner area of the island and decreases as dwell time grows. By varying the ion fluence we found that such a shape is related to a surface swelling effect occurring at low ion fluence in the irradiated areas. The swelling-related damage at the edges is expected to influence the magnetic properties of the patterned ...

2005-04-01

101

Submicron-scale patterns on ferromagnetic-antiferromagnetic Fe/NiO layers by focused ion beam (FIB) milling  

International Nuclear Information System (INIS)

With the aim of studying the magnetic properties of reduced-dimensionality magnetic systems we have patterned 250 nm- and 500 nm-size square elements on Fe/NiO layers by 30 keV Ga"+ focused ion beam (FIB) milling, varying beam current and pixel dwell time. By high resolution scanning electron microscope (SEM) imaging and atomic force microscopy (AFM) analysis we found that island size decreases from the nominal value by increasing the beam current and features sharpness improves on increasing the dwell time. The top surface of the isolated features has a pronounced edge bending which may be as high as 9 nm with respect to the flat inner area of the island and decreases as dwell time grows. By varying the ion fluence we found that such a shape is related to a surface swelling effect occurring at low ion fluence in the irradiated areas. The swelling-related damage at the edges is expected to influence the magnetic properties of the patterned ...

2005-04-01

102

Study of structural and optical properties of sprayed WO{sub 3} thin films using enhanced characterization techniques along with the Boubaker Polynomials Expansion Scheme (BPES)  

Energy Technology Data Exchange (ETDEWEB)

In this study, WO{sub 3} thin films were grown on glass substrates using an aqueous solution containing tungstate (NH{sub 4}){sub 2}WO{sub 4} as precursor. The substrate temperature incremented from 250 to 500 deg. C, by steps of 50 deg. C. The structural properties were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. Microprobe analyses showed that a balanced stoichiometric composition was obtained for thin films prepared at T{sub s} = 350 and 400 deg. C. The X-ray diffraction analyses showed different structure crystallography in function of the substrate temperature. Moreover, films deposited at 400 deg. C were annealed in air for 2 h at 450 and 500 deg. C, respectively and the structural changes due to heat treatment were studied. Finally, the optical properties of these films were carried out using optical measurements of transmittance T({lambda}) and reflectance R({lambda}) spectra in ...

2009-11-13

103

Study of structural and optical properties of sprayed WO3 thin films using enhanced characterization techniques along with the Boubaker Polynomials Expansion Scheme (BPES)  

International Nuclear Information System (INIS)

In this study, WO3 thin films were grown on glass substrates using an aqueous solution containing tungstate (NH4)2WO4 as precursor. The substrate temperature incremented from 250 to 500 deg. C, by steps of 50 deg. C. The structural properties were investigated using XRD, atomic force microscopy and scanning electronic microscopy techniques. Microprobe analyses showed that a balanced stoichiometric composition was obtained for thin films prepared at Ts = 350 and 400 deg. C. The X-ray diffraction analyses showed different structure crystallography in function of the substrate temperature. Moreover, films deposited at 400 deg. C were annealed in air for 2 h at 450 and 500 deg. C, respectively and the structural changes due to heat treatment were studied. Finally, the optical properties of these films were carried out using optical measurements of transmittance T(?) and reflectance R(?) spectra in 300-1800 nm domain. The refractive and absorption ...

2009-11-13

104

Study of porous silicon morphologies for electron transport  

International Nuclear Information System (INIS)

Field emitter devices are being developed for the gigatron, a high-efficiency, high frequency and high power microwave source. One approach being investigated is porous silicon, where a dense matrix of nanoscopic pores are galvanically etched into a silicon surface. In the present paper pore morphologies were used to characterize these materials. Using of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images of both N-type and P-type porous layers, it is found that pores propagate along the <100> crystallographic direction, perpendicular to the surface of (100) silicon. Distinct morphologies were observed systematically near the surface, in the main bulk and near the bottom of N-type (100) silicon lift-off samples. It is seen that the pores are not cylindrical but exhibit more or less approximately square cross sections. X-ray diffraction spectra and electron diffraction patterns verified that bulk porous silicon is still a single crystal. In ...

1993-05-17

105

Studies on reactivity of coal surfaces at low temperature; Teion ni okeru sekitan hyomen no hannosei no kento  

Energy Technology Data Exchange (ETDEWEB)

With an objective to learn reactivity of coal at its surface, surfaces of oxidized coal samples were investigated. Miike coal was oxidized by using {sup 18}O2 in a closed loop system. As the reaction progresses, proportion of CO2 including isotopes increased rapidly as a result of oxidation of CO sites existing in the coal and the newly generated C{sup 18}O sites. The oxidizing reaction progressed via oxygen adsorbing sites generated near the surface, and oxygen containing groups. An FT-IR analysis estimated the depth of the oxidized layer to be 10{mu}m or less from particle surface. The oxidized coal was pulverized to see its surface condition. Functional groups introduced by the oxidation enter into the vicinity of the surface in a form to desorb as CO. CO2 is trapped in inner pores. The coal surface was observed by using an atomic force microscope. No observable openings in the pore structure were discerned on the surface before the ...

1996-10-28

106

SnO{sub 2} thin films morphological and optical properties in terms of the Boubaker Polynomials Expansion Scheme BPES-related Opto-Thermal Expansivity {psi}{sub AB}  

Energy Technology Data Exchange (ETDEWEB)

In this study, SnO{sub 2} thin films have been grown using spray pyrolysis technique on glass substrates under a substrate temperature (T{sub s} = 440 {sup o}C). The precursors were methanol CH{sub 4}O and anhydrous tin tetrachloride. XRD analyses yielded strong (1 1 0)-(1 0 1)-(2 0 0) X-ray diffraction peaks which are characteristics to tetragonal crystals. Atomic Force Microscopy (AFM) analyses showed the existence of clusters with particular pyramidal shapes. The main part of this study concerns the optical measurements of transmittance T({lambda}) and reflectance R({lambda}) spectra inside 250-1800 nm domain. Conjoint optical and thermal properties were deduced using the Amlouk-Boubaker Opto-Thermal Expansivity {psi}{sub AB}. The obtained value: {psi}{sub AB} {approx} 23.4 m{sup 3} s{sup -1} helped situating the performance of the as-grown SnO{sub 2} compound among most known PV-T oxides like ZnO and TiO{sub 2}.

2010-02-04

107

SnO2 thin films morphological and optical properties in terms of the Boubaker Polynomials Expansion Scheme BPES-related Opto-Thermal Expansivity ?AB  

International Nuclear Information System (INIS)

In this study, SnO2 thin films have been grown using spray pyrolysis technique on glass substrates under a substrate temperature (Ts = 440 oC). The precursors were methanol CH4O and anhydrous tin tetrachloride. XRD analyses yielded strong (1 1 0)-(1 0 1)-(2 0 0) X-ray diffraction peaks which are characteristics to tetragonal crystals. Atomic Force Microscopy (AFM) analyses showed the existence of clusters with particular pyramidal shapes. The main part of this study concerns the optical measurements of transmittance T(?) and reflectance R(?) spectra inside 250-1800 nm domain. Conjoint optical and thermal properties were deduced using the Amlouk-Boubaker Opto-Thermal Expansivity ?AB. The obtained value: ?AB ? 23.4 m3 s-1 helped situating the performance of the as-grown SnO2 compound among most known PV-T oxides like ZnO and TiO2.

2010-02-04

108

Properties of ZnO thin films prepared by radio-frequency plasma beam assisted laser ablation  

International Nuclear Information System (INIS)

Zinc oxide thin films were obtained by laser ablation of a Zn target in oxygen reactive atmosphere, the oxygen being supplied either by a standard gas inlet valve or from a radio-frequency (rf) oxygen plasma. Pt-coated silicon and MgO were used as substrates. The influence of the deposition parameters as laser wavelength (266, 355, 1064 nm), laser fluence (1.5-20 J/cm2) and oxygen pressure (1-60 Pa) was studied. The influence of the rf plasma beam addition on the morphological proprieties of zinc oxide films was particularly investigated, simultaneously with several configurations of the direction of the ablation plasma, the rf plasma beam and the substrate. The obtained films, with thicknesses in the range of 50 nm to 1 ?m have been characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), transmission electron microscopy (TEM).

2005-07-15

109

Preparation of nanostructure Ni doped CdO thin films by sol gel spin coating method  

British Library Electronic Table of Contents (United Kingdom)

The nanostructure Ni-doped CdO films have been prepared by sol gel spin coating method. Atomic force microscopy results indicate that the CdO films are formed from the nanoparticles and the grain size is changed with nickel content. X-ray diffraction patterns of the films indicate that the undoped and Ni-doped CdO films have polycrystalline structure with a cubic sodium chloride structure, showing two main characteristic peaks assigned to the (111) and (200) planes. The optical band gap values of undoped and Ni-doped CdO films were determined by optical absorption method. The Eg values of the CdO films were found to be in the range of 2.26?2.60?eV. The Eg values of the CdO films increase with the content of Ni dopant (up to 6% Ni). It is evaluated that the optical band gap and grain size o...

2011-01-01

110

Preparation and photocatalytic property of pyrochlore Bi{sub 2}Ti{sub 2}O{sub 7} and (Bi, La) {sub 2}Ti{sub 2}O{sub 7} films  

Energy Technology Data Exchange (ETDEWEB)

Dopant-free Bi{sub 2}Ti{sub 2}O{sub 7} thin films with pyrochlore structure and La-doped bismuth titanate thin films have been fabricated by means of chemical solution decomposition, and characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy and UV-Vis spectrophotometry in this study. Their photocatalytic activities have been evaluated by photodegrading methyl orange solution, and the optimum processing parameters for the highest photocatalytic activity have been found. Moreover, the effects of La-doping on the phase transformation and the photocalalytic activity have been studied. It has been deduced from the experiment result that substituted La{sup 3+} ions can act as a stabilizer of Aurivillus phase BLT and a grain-growth inhibitor in BLT thin films.

2008-11-28

111

P-LIGA: 3D-integration of microstructures with curved surfaces by deep ion irradiation  

International Nuclear Information System (INIS)

Using the advantage that the projected range of ions in matter is sharply limited, a new technique for the production of three-dimensional microstructures has been developed. Based on the P-LIGA technique (Proton-Lithographie, Galvanoformung, Abformung) this process allows the generation of structures with surfaces of almost any shape having a root mean square roughness of about #lambda#/50 for visible light wavelengths. An ion beam with diameters between 2 and 50 #mu#m is directly writing the structures and the shape is varied by geometrical manipulation of the sample in three axes during the exposure. Practically, structures have been written using protons with an energy of 1.8 MeV in a provisional experimental setup with beam diameters of 10 and 50 #mu#m, respectively. After irradiation, the parts exposed were dissolved in a liquid developer without affecting the nonirradiated parts. The shape and the rms roughness of the resulting structures were estimated by optical microscopy and ...

1998-04-01

112

Optical Pattern Fabrication in Amorphous Silicon Carbide with High-Energy Focused Ion Beams  

International Nuclear Information System (INIS)

Topographic and optical patterns have been fabricated in a-SiC films with a focused high-energy (1 MeV) H"+ and He"+ ion beam and examined with near-field techniques. The patterns have been characterized with atomic force microscopy and scanning near-field optical microscopy to reveal local topography and optical absorption changes as a result of the focused high-energy ion beam induced modification. Apart of a considerable thickness change (thinning tendency), which has been observed in the ion-irradiated areas, the near-field measurements confirm increases of optical absorption in these areas. Although the size of the fabricated optical patterns is in the micron-scale, the present development of the technique allows in principle writing optical patterns up to the nanoscale (several tens of nanometers). The observed values of the optical contrast modulation are sufficient to justify the efficiency of the method for optical data recording using ...

2011-07-01

113

Nanostructuring the graphite basal plane by focused ion beam patterning and oxygen etching  

International Nuclear Information System (INIS)

Ga"+ focused ion beam (FIB) patterning was used to structure highly oriented pyrolytic graphite surfaces with square, periodic arrays of amorphous carbon defects (mesh sizes: 300 nm-2 #mu#m). Controlled oxygen etching of these arrays leads to matrices of uniform, orientationally aligned, nm-sized, hexagonal holes. The properties of the resulting hole assembly (hole depths and lateral hole dimensions) have been investigated by means of atomic force microscopy, scanning electron microscopy and FIB sectioning. The hole dimensions and uniformity both depend on the FIB parameters and etching conditions. Etching temperatures from 500 to 700 deg. C were applied. Initial etch rates of up to 10"6 C s"-"1 per individual hole were observed when using oxygen pressures of 200 mbar. For an etch temperature of 590 deg. C the rate of etching of individual holes was found to depend measurably on the inter-hole separation. This confirms that the associated ...

2006-12-14

114

Nanoporous structure formations on germanium surfaces by focused ion beam irradiations  

International Nuclear Information System (INIS)

The formation of porous structures of nanometre size (nanoporous structures) on germanium (Ge) surfaces by focused ion beam (FIB) irradiations was investigated using various FIB conditions such as ion species, irradiation energies, total fluences, fluence rates, and incident angles. FIB-irradiated regions were observed using a scanning electron microscope and an atomic force microscope. It is found that, using a focused Ga ion beam (Ga FIB) at an energy of 100 keV, the irradiated Ge surface swelled up to ion fluence of 2 x 10"1"7 cm"-"2 with nanoporous structures and then was etched for larger fluences. The shape of swollen nanoporous structures depended on the fluence rate and the incident angle of the Ga FIB. However, such porous structures were observed neither for low-energy (15-30 keV) FIB irradiations using Si and Au ions nor for high-energy (200 keV), heavy ion (Au) irradiation. These observations might be helpful in discussing the ...

2007-11-07

115

Mott-Schwinger Scattering of Polarized Low Energy Neutrons up to Thermal Energies  

Energy Technology Data Exchange (ETDEWEB)

The availability of new, high-intensity, cold and thermal neutron sources has opened the possibility of performing high-precision fundamental neutron physics experiments, including measurements that study the hadronic weak interaction and standard model test measurements, using neutron decay. The observables in these experiments are usually correlated with the direction of neutron polarization and are often very small (10 8 10 6). Mott-Schwinger scattering of polarized neutrons can produce spin-dependent shifts in beam centroids, which has the potential to produce significant systematic effects for these types of experiments. An accurate calculation of this process for neutral atoms and basic molecules has not been carried out for low neutron energies. In this work, we derive a general expression for the electromagnetic (Mott-Schwinger) contributions to the analyzing power for low-energy neutron scattering. We obtain numerical results for 11 nuclei in the range of ...

2008-10-01

116

Micropatterned polysaccharide surfaces via laser ablation for cell guidance  

Energy Technology Data Exchange (ETDEWEB)

Micropatterned materials were obtained by a controlled laser ablation of a photoimmobilised homogeneous layer of hyaluronic acid (Hyal) and its sulphated derivative (HyalS). The photoimmobilisation was performed by coating the polysaccharide, adequately functionalised with a photoreactive group, on aminosilanised glass substrate and immobilising it on the surface under UV light. Hyal or HyalS photoimmobilised samples were then subjected to laser ablation with wavelengths in the UV regions in order to drill the pattern. Four different patterns with stripes of 100, 50, 25 and 10 {mu}m were generated. A chemical characterisation by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) and time of flight-secondary ions mass spectrometry (TOF-SIMS) confirmed the success of the laser ablation procedure and the presence of alternating stripes of polysaccharide and native glass. The exact dimensions of the stripes were determined by atomic ...

2003-03-03

117

Liquid waste evaporator operating experience  

Energy Technology Data Exchange (ETDEWEB)

Atomic Energy of Canada Limited (AECL) operates the Waste Treatment Centre (WTC) to treat and immobilize some of the low- level radioactive waste (LLRW) streams at the Chalk River Laboratories (CRL). The WTC at treats low- level radioactive liquid waste by removing the contaminants from the wastewater, concentrating them, and immobilizing them. The fundamental design concept for the WTC is to process the waste streams using forced circulation type liquid waste evaporation (LWE), to solidify the concentrates using thin film evaporator and to discharge the purified effluent into the Ottawa River following verification monitoring. The solidified product drums are stored in existing storage facilities in the CRL. The LWE was installed in the WTC to treat the LLRW. After about four (4) years of design, construction and cold commissioning, the active commissioning of the evaporator process using radioactive waste streams commenced in February 2000. ...

2006-07-01

118

Liquid waste evaporator operating experience  

International Nuclear Information System (INIS)

Atomic Energy of Canada Limited (AECL) operates the Waste Treatment Centre (WTC) to treat and immobilize some of the low- level radioactive waste (LLRW) streams at the Chalk River Laboratories (CRL). The WTC at treats low- level radioactive liquid waste by removing the contaminants from the wastewater, concentrating them, and immobilizing them. The fundamental design concept for the WTC is to process the waste streams using forced circulation type liquid waste evaporation (LWE), to solidify the concentrates using thin film evaporator and to discharge the purified effluent into the Ottawa River following verification monitoring. The solidified product drums are stored in existing storage facilities in the CRL. The LWE was installed in the WTC to treat the LLRW. After about four (4) years of design, construction and cold commissioning, the active commissioning of the evaporator process using radioactive waste streams commenced in February 2000. ...

2005-05-08

119

Layer-by-layer self-assembly of polyimide precursor/layered double hydroxide ultrathin films  

International Nuclear Information System (INIS)

The layer-by-layer (LBL) self-assembly has been extensively used as a simple and effective method for the preparation of polyelectrolyte multilayer films. In this work, we utilized this unique method to prepare polyimide precursor/layered double hydroxide (LDH) ultrathin films. Well-crystallized Co-Al-CO_3 LDH and subsequent anion exchanged Co-Al-NO_3 LDH were prepared and characterized by scanning electron microscopy and X-ray diffraction (XRD). By vigorous shaking of the as-prepared Co-Al-NO_3 LDH, positively charged and exfoliated LDH nanosheets were obtained. Atomic force microscopy and XRD investigations indicated the delamination of LDH nanosheets. The precursor of polyimide, poly(amic acid) tertiary amine salt (PAS) was prepared by the polycondensation of dianhydride and diamine, and subsequent amine salt formation. By using the LBL method, heterogeneous ultrathin films of PAS and LDH were prepared. The formation of the ordered ...

2010-09-30

120

Ion beam mixing in Fe/Si and Ta/Si bilayers: Possible effects of ion charges  

Energy Technology Data Exchange (ETDEWEB)

Thin Fe and Ta layers of 30-45 nm thickness, deposited via magnetron sputtering on Si (1 0 0) substrates, were bombarded at room temperature with 100 keV Ar{sup 1+} or Ar{sup 8+} or with 250 keV Xe{sup 1+} or Xe{sup 19+} ions in order to test the influence of the ion charge state on the surface sputtering and interface mixing. The samples were characterized by means of Rutherford backscattering at 0.9-3.0 MeV {alpha}-particle energy, time-of-flight elastic recoil detection analysis with a 53 MeV {sup 127}I{sup 10+} beam and atomic force microscopy. No influence of the charge state on the sputtering and athermal mixing rate was observed in the case of the Ta/Si system. However, in the case of the Fe/Si system, the ion charge was observed to have an influence on the mixing rate.

2003-05-01

121

Hydrogen-related surface modifications of 20 nm thin straight-sided niobium nano-wires and niobium meander-films  

Energy Technology Data Exchange (ETDEWEB)

Nano-wire arrays of Niobium were produced by small angle sputtering on facetted sapphire, using the self shadowing effect of the facets. A wire width of about 80 nm was adjusted, the mean (maximum) wire height was about 20 nm (30 nm), the length can be in the cm range. Meander-film morphologies of 20 nm mean (26 nm maximum) thickness were produced by conventional sputtering onto smooth sapphire substrates at elevated temperatures. The morphology of the wires was investigated with atomic force microscopy (AFM), using contact mode. Meander-films were studied by scanning tunnelling microscopy (STM). Hydrogen loading was performed by instantaneously increasing the hydrogen gas pressure above the solubility limit. Thus, an elongated hydride could be monitored in an about 30 nm thick wire. STM studies on meander-films show the presence of cylindrical hydrides. Local out-of-plane and in-plane expansion can be explained by the formation of hydrides, ...

2007-10-31

122

Human tooth enamel dissolution in citric acid as a function of degree of saturation and pH  

CERN Document Server

There is increasing concern among the dental community regarding the damage caused to teeth by the acids in soft drinks. Enamel dissolution in acidic solution can be reduced by addition of calcium and/or phosphate salts to increase the degree of saturation with respect to hydroxyapatite (DS sub H sub A), or by an increase in pH. In soft drinks, however, both of these approaches are associated with a reduced taste quality. The separate effects of each parameter are not known. In the work presented here, enamel dissolution was studied in citric acid solutions with compositions typical of soft drinks. Nanoindentation and atomic force microscopy (AFM) were used to investigate very early stages of enamel dissolution, with typical exposure times of 30-600 s. Preliminary investigations of the application of SIMS, ESEM and XPS to enamel dissolution studies are also reported. The individual effects of DS sub H sub A , pH and calcium and phosphate ...

2002-01-01

123

HISTORICAL AMERICAN ENGINEERING RECORD - IDAHO NATIONAL ENGINEERING AND ENVIRONMENTAL LABORATORY, TEST AREA NORTH, HAER NO. ID-33-E  

Energy Technology Data Exchange (ETDEWEB)

Test Area North (TAN) was a site of the Aircraft Nuclear Propulsion (ANP) Project of the U.S. Air Force and the Atomic Energy Commission. Its Cold War mission was to develop a turbojet bomber propelled by nuclear power. The project was part of an arms race. Test activities took place in five areas at TAN. The Assembly & Maintenance area was a shop and hot cell complex. Nuclear tests ran at the Initial Engine Test area. Low-power test reactors operated at a third cluster. The fourth area was for Administration. A Flight Engine Test facility (hangar) was built to house the anticipated nuclear-powered aircraft. Experiments between 1955-1961 proved that a nuclear reactor could power a jet engine, but President John F. Kennedy canceled the project in March 1961. ANP facilities were adapted for new reactor projects, the most important of which were Loss of Fluid Tests (LOFT), part of an international safety program for commercial power reactors. ...

2005-02-01

124

Growth and characterisation of electrodeposited ZnO thin films  

Energy Technology Data Exchange (ETDEWEB)

The electrochemical method has been used to deposit zinc oxide (ZnO) thin films from aqueous zinc nitrate solution at 80 deg. C onto fluorine doped tin oxide (FTO) coated glass substrates. ZnO thin films were grown between - 0.900 and - 1.025 V vs Ag/AgCl as established by voltammogram. Characterisation of ZnO films was carried out for both as-deposited and annealed films in order to study the effect of annealing. Structural analysis of the ZnO films was performed using X-ray diffraction, which showed polycrystalline films of hexagonal phase with (002) preferential orientation. Atomic force microscopy was used to study the surface morphology. Optical studies identified the bandgap to be {approx} 3.20 eV and refractive index to 2.35. The photoelectrochemical cell signal indicated that the films had n-type electrical conductivity and current-voltage measurements showed the glass/FTO/ZnO/Au devices exhibit rectifying properties. The thickness of ...

2008-04-30

125

Focused ion beam machined nanostructures depth profiled by macrochannelling ion beam analysis  

International Nuclear Information System (INIS)

High aspect ratio sub-#mu#m periodic structures fabricated by focused ion beam (FIB) lithography have been characterised by Rutherford backscattering spectrometry (RBS) using the macrochannelling technique. The technique overcomes the limitations of complementary techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM), which can provide images with sub-#mu#m resolution of just the surface features and not of the deep sub-surface structures, without destructive cross sectioning of the sample. Here RBS macrochannelling with a 2 MeV He"+ ion beam is used to analyse a diffraction grating fabricated by FIB milling an array of 100 nm wide trenches in a 300 nm thick Ag film on a Si substrate. Using the surface structure imaged by SEM and AFM as a starting point, a numerical model for the RBS spectrum from the grating is fitted to the experimental spectrum as a function of the sub-surface structure. This process allows ...

2006-08-01

126

Failure analysis of surface-micromachined microengines  

Energy Technology Data Exchange (ETDEWEB)

Microelectronic failure analysis (FA) has been an integral part of the development of state-of-the-art integrated circuits. FA of MicroElectroMechanical Systems (MEMS) is moving from its infancy stage to assume an important role in the successful design, fabrication, performance and reliability analysis for this new technology. In previous work, the authors focused on the application of several techniques developed for integrated circuit analysis to an earlier version of a surface micromachined microengine fabricated at Sandia. Recently, they have identified important new failure modes in binary counters that incorporate a newer design of the microengine, using a subset of integrated circuit failure analysis techniques including optical microscopy, focused ion beam (FIB) techniques, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The primary failure mode they have identified is directly related to visible wear on bearing ...

1998-11-01

127

Evolution of surface roughness in silicon X-ray mirrors exposed to a low-energy ion beam  

International Nuclear Information System (INIS)

The possibility of smoothening aspherical X-ray mirrors by irradiation of the surface with a low-energy ion beam is investigated. Nanofocusing being the primary application of these mirrors the ion beam conditions must be optimized to achieve a surface roughness of the order of 0.1-0.2 nm. To address this issue a first study was performed on silicon flat substrates etched using ion energies ranging from 400 to 1200 eV. A second study consisted of eroding the silicon surface while varying the ion grazing incidence angle between 10 deg. and 90 deg. for a fixed value of the ion energy. The surface topography of the samples was characterized at various scales using atomic force microscopy (probed area: 1-10 ?m2), interferential optical microscopy (probed area: 1 mm2) and X-ray scattering (probed area: 100 mm2). Finally, a study by AFM of the evolution of the surface finish level of a silicon mirror after ion erosion at various depth values up to 10 ...

2010-05-01

128

Epitaxial stabilization of MnO(111) overlayers on a Pd(100) surface  

International Nuclear Information System (INIS)

The growth of epitaxial MnO(100) and MnO(111) layers on Pd(100) surface has been investigated by spot-profile analysis low-energy electron diffraction, dynamic atomic force microscopy, photoemission and high-resolution electron energy loss spectroscopy, and density functional theory. We have found that despite the large lattice mismatch to the Pd(100) substrate, the MnO(100) layers are kinetically stabilized at low temperatures (?350 deg. C) and at oxygen pressures between 2x10-7 and 5x10-7 mbar. Annealing in ultrahigh vacuum at 650 deg. C or, alternatively, deposition of manganese metal in oxygen pressure -7 mbar causes the transformation of the MnO(100) to a polar MnO(111) surface, which is decorated by triangular pyramids with (100) side facets. It is suggested that the growth of MnO(111) layers is energetically preferred over MnO(100) due to the epitaxial stabilization at the metal-oxide interface.

2007-06-01

129

Effects of local texture and grain structure on the sputtering performance of tantalum  

Energy Technology Data Exchange (ETDEWEB)

Tantalum and tantalum-based thin films have gained precedence as the diffusion barrier for copper interconnects used in the latest generation of integrated circuits (ICs). The paper presents insight and observations on the covariance of texture and grain size of wrought tantalum sputtering targets and their influence on sputtering performance. Previous studies involving deposition trials of tantalum targets of varying metallurgical character had demonstrated that both grain size and textural homogeneity is critical for assuring reliable sputtering performance of tantalum. Subsequently, a model had been proposed to prescribe how localized texture bands and orientation clusters in tantalum are effectively resistant to sputter erosion. In this paper, results of atomic force microscopy (AFM) and orientation imaging microscopy (OIM{sup TM}) analyses on the eroded surface of a tantalum sputtering target are presented. Initial findings support the ...

2002-07-01

130

Effects of focused-ion-beam irradiation on perpendicular write head performance  

International Nuclear Information System (INIS)

The effects of focused-ion-beam (FIB) irradiation on writer performance were examined on a perpendicular recording system. The entire top pole was irradiated by FIB with ion doses from 0 to 300 pC/#mu#m"2. PW_5_0 and signal to noise ratio (SNR) were characterized using a spin stand before and after FIB irradiation. It was found that there is degradation of PW_5_0 and SNR due to FIB irradiation. At the maximum dose (300 pC/#mu#m"2), PW_5_0 increased by 33 nm (>30%) and SNR decreased by 5 dB (>25%). The degradation was attributed to the physical pole tip recession and the formation of a magnetic dead layer. The thickness of the magnetic dead layer was estimated by analyzing the write spacing loss. Using atomic force microscopy and stage current change monitored during FIB process, it was found that the entire 4-nm protective carbon layer was etched away with a dose of 25 pC/#mu#m"2. This result implies that the degradation with ion doses ...

2003-05-15

131

Direct patterning of gold oxide thin films by focused ion-beam irradiation  

International Nuclear Information System (INIS)

For direct writing of electrically conducting connections and areas into insulating gold oxide thin films a scanning Ar"+ laser beam and a 30 keV Ga"+ focused ion beam (FIB) have been used. The gold oxide films are prepared by magnetron sputtering under argon/oxygen plasma. The patterning of larger areas (dimension 10-100 #mu#m) has been carried out with the laser beam by local heating of the selected area above the decomposition temperature of AuO_x(130-150 C). For smaller dimensions (100 nm to 10 #mu#m) the FIB irradiation could be used. With both complementary methods a reduction of the sheet resistance by 6-7 orders of magnitude has been achieved in the irradiated regions (e.g. with FIB irradiation from 1.5 x 10"7#OMEGA#/#square# to approximately 6 #OMEGA#/#square#). The energy-dispersive X-ray analysis (EDX) show a considerably reduced oxygen content in the irradiated areas, and scanning electron microscopy (SEM), as well as atomic force ...

2000-09-01

132

Deposition of plasma-polymerized hydroxyethyl methacrylate (HEMA) on silicon in presence of argon plasma  

International Nuclear Information System (INIS)

2-hydroxyethyl methacrylate (HEMA) has been deposited onto the surface of silicon substrate (thickness = 500 ?m) using plasma polymerization technique. Polymerization process was carried out in an in-house developed inductively coupled plasma polymerization setup. The depositions were carried out using RF power supply (13.56 MHz) at power of 75 W for 10 and 40 min. The RF supply was coupled to the inductance through a matching network. The effect of plasma polymerization (surface grafting) on the degree of surface modification has been investigated. The chemical changes on the polymer backbone are followed from the results of Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS), which show the peaks corresponding to the functional groups of the HEMA polymerized onto the silicon surface. The morphology of the modified surfaces has also been investigated using scanning electron microscopy (SEM) and atomic ...

2005-05-30

133

Crosscheck of different techniques for two dimensional power spectral density measurements of x-ray optics  

Energy Technology Data Exchange (ETDEWEB)

The consistency of different instruments and methods for measuring two-dimensional (2D) power spectral density (PSD) distributions are investigated. The instruments are an interferometric microscope, an atomic force microscope (AFM) and the X-ray Reflectivity and Scattering experimental facility, all available at Lawrence Berkeley National Laboratory. The measurements were performed with a gold-coated mirror with a highly polished stainless steel substrate. It was shown that these three techniques provide essentially consistent results. For the stainless steel mirror, an envelope over all measured PSD distributions can be described with an inverse power-law PSD function. It is also shown that the measurements can be corrected for the specific spatial frequency dependent systematic errors of the instruments. The AFM and the X-ray scattering measurements were used to determine the modulation transfer function of the interferometric microscope. ...

2005-07-12

134

Cross-check of different techniques for two-dimensional powerspectral density measurements of X-ray optics  

Energy Technology Data Exchange (ETDEWEB)

The consistency of different instruments and methods for measuring two-dimensional (2D) power spectral density (PSD) distributions are investigated. The instruments are an interferometric microscope, an atomic force microscope (AFM) and the X-ray Reflectivity and Scattering experimental facility, all available at Lawrence Berkeley National Laboratory. The measurements were performed with a gold-coated mirror with a highly polished stainless steel substrate. It was shown that these three techniques provide essentially consistent results. For the stainless steel mirror, an envelope over all measured PSD distributions can be described with an inverse power-law PSD function. It is also shown that the measurements can be corrected for the specific spatial frequency dependent systematic errors of the instruments. The AFM and the X-ray scattering measurements were used to determine the modulation transfer function of the interferometric microscope. ...

2005-04-17

135

Controllable synthesis of graphene sheets with different numbers of layers and effect of the number of graphene layers on the specific capacity of anode material in lithium-ion batteries  

International Nuclear Information System (INIS)

High quality graphene sheets are synthesized through efficient oxidation process followed by rapid thermal expansion and reduction by H2. The number of graphene layers is controlled by tuning the oxidation degree of GOs. The higher the oxidation degree of GOs is getting, the fewer the numbers of graphene layers can be obtained. The material is characterized by elemental analysis, thermo-gravimetric analysis, scanning electron microscopy, atomic force microscopy, transmission electron microscopy and Fourier transform infrared spectroscopies. The obtained graphene sheets with single, triple and quintuplicate layers as anode materials exhibit a high reversible capacity of 1175, 1007, and 842 mA h g-1, respectively, which show that the graphene sheets with fewer layers have higher reversible capacity. -- Graphical abstract: The typical TEM images of the graphene sheets derived from GO3(a), GO2(b) and GO1(c). Display Omitted Highlights: ? With the ...

2011-05-01

136

Comparison of plasma chemistries for inductively coupled plasma etching of InGaAlP alloys  

International Nuclear Information System (INIS)

Two plasma chemistries, i.e., CH_4/H_2/Ar and Cl_2/Ar, were compared for the etching of InGaP, AlInP, and AlGaP under inductively coupled plasma (ICP) conditions. While the etching with CH_4/H_2/Ar discharges appears to be ion driven, Cl_2/Ar discharges showed an additional strong chemical enhancement. The highest etch rate (#approx#1 #mu#m/min) for InGaP was achieved at high ICP source power (#>=#750 W) with the Cl_2/Ar chemistry. Cl_2/Ar discharges provided very smooth surfaces in all three materials with root-mean-square roughness measured by atomic force microscopy around 2 nm. This result may be due to the efficient ion-assisted product desorption in this chemistry. The etched near-surface region of InGaP (#approx#100 Angstrom) with Cl_2/Ar maintained almost the same stoichiometry as that of the unetched control. By contrast, the CH_4/H_2/Ar plasma chemistry produced somewhat rougher surfaces and depletion of phosphorous (P) from the ...

1998-05-01

137

Cell behaviour on chemically microstructured surfaces  

Energy Technology Data Exchange (ETDEWEB)

Micropatterned surfaces with different chemical topographies were synthesised in order to investigate the influence of surface chemistry and topography on cell behaviour. The microstructured materials were synthesised by photoimmobilising natural Hyaluronan (Hyal) and its sulphated derivative (HyalS), both adequately functionalised with a photorective moiety, on glass substrates. Four different grating patterns (10, 25, 50 and 100 {mu}m) were used to pattern the hyaluronan. The micropatterned samples were analysed by Secondary Ions Mass Spectrometry, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy to investigate the chemistry and the topography of the surfaces. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask patterns were well reproduced on the sample surface. The influence of chemical topographies on the cell ...

2003-03-03

138

BINERY PSEUDO-RANDOM GRATING AS A STANDARD TEST SURFACE FOR MEASUREMENT OF MODULATION TRANSFER FUNCTION OF INTERFEROMETRIC MICROSCOPES.  

Energy Technology Data Exchange (ETDEWEB)

The task of designing high performance X-ray optical systems requires the development of sophisticated X-ray scattering calculations based on rigorous information about the optics. One of the most insightful approaches to these calculations is based on the power spectral density (PSD) distribution of the surface height. The major problem of measurement of a PSD distribution with an interferometric and/or atomic force microscope arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF characterizes the perturbation of the PSD distribution at higher spatial frequencies. Here, we describe a new method and dedicated test surfaces for calibration of the MTF of a microscope. The method is based on use of a specially designed Binary Pseudo-random (BPR) grating. Comparison of a theoretically calculated PSD spectrum of a BPR grating with a spectrum measured with the grating provides the desired calibration of the ...

2007-08-01

139

An investigation of the capacitance dispersion on the fractal carbon electrode with edge and basal orientations  

Energy Technology Data Exchange (ETDEWEB)

Capacitance dispersion on the fractal carbon electrode with edge and basal orientations was investigated using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and a.c.-impedance spectroscopy. For this purpose, four types of as-received pyrolytic graphite electrode, as-received, mechanically polished, and as-activated glassy carbon electrodes were prepared with different surface irregularities and amounts of edge orientations. The apparent self-similar fractal dimensions of the carbon electrodes were determined from the analyses of AFM images based upon triangulation method. The amounts of edge orientations on the surface of the carbon electrodes were qualitatively estimated from the XPS analysis of surface acidic functional groups that were preferably formed on the edge planes by the heat treatment of the carbon electrodes. The values of the constant phase element exponent {alpha} determined from the apparent self-similar ...

2003-10-15

140

An alpha-K{sub 3}PMo{sub 3}W{sub 9}O{sub 40} film loaded with silver nanoparticles: Fabrication, characterization and properties  

Energy Technology Data Exchange (ETDEWEB)

A composite film consisting of the mixed-addenda Keggin-type polyoxometalate alpha-K{sub 3}PMo{sub 3}W{sub 9}O{sub 40} (PMo{sub 3}W{sub 9}) and silver nanoparticles (AgNPs) was fabricated on quartz, silicon, and ITO by the layer-by-layer self-assembly method. The regular growth of the multilayer film was monitored by UV-vis spectroscopy, and the morphology was measured by atomic force microscopy (AFM). The multilayer film embedded by AgNPs exhibited the photo-luminescence ascribed to electronic transitions from excited states to d levels of the silver nanoparticles. The composite film also showed electrocatalytic activity towards reduction of NO{sub 2}{sup -}, H{sub 2}O{sub 2}, ClO{sub 3}{sup -}, BrO{sub 3}{sup -}, and IO{sub 3}{sup -} attributed to tungsten-centered and molybdenum-centered redox processes of PMo{sub 3}W{sub 9}.

2009-12-01

141

A structural and corrosion study of triethoxysilyl and perfluorooctyl functionalized polyhedral silsesquioxane nanocomposite films on AA 2024 alloy  

International Nuclear Information System (INIS)

A tri-functional polyhedral oligomeric silsesquioxane (POSS) based silane precursor R_xR_yR_z(SiO_3_/_2)_n (x + y + z = n = 6, 8, 10, ...) bearing 3-(N-(3-triethoxysilylpropyl)ureido)propyl, isooctyl and perfluoropropyl groups was synthesized and investigated as corrosion protective coating for AA 2024 alloy. Infrared reflection-absorption (IR RA) combined with X-ray photoelectron spectroscopy and atomic force microscopy provided information about partial self-assembling of coatings having a fluorine enriched upper layer with a low surface energy (#gamma#"t"o"t = 12.37 mN/m). The structural changes that accompanied corrosion produced under chronocoulometrical conditions were assessed from ex-situ IR RA spectra. A new band at 1690-1700 cm"-"1 appeared above the corrosion potential, and was assigned to the formation of amidonium ions and consequent relaxation of urea-urea associations.

2010-03-01

142

Deforestation in Mato Grosso, Brazil - NASA  

Science.gov (United States)

Deforestation in Mato Grosso, Brazil. atom_author. atom_name, Jesse Allen. atom_link. kml_href, http://earthobservatory.nasa.gov/Feeds/GoogleEarth/ ...

143

Predicting the response of high damping rubber bearings using simplified models and finite element analysis  

International Nuclear Information System (INIS)

The International Atomic Energy Agency has initiated a co-ordinated research programme on implementation of base-isolation for nuclear structures. This paper discusses two areas relevant to modelling elastomeric base-isolators. These are the use of simplified models to predict the response of isolated structures to earthquake inputs and finite element analysis for calculating the stress distributions within the isolators. In the former, a curvilinear hysteretic model of the high damping natural rubber able to accommodate the stiffening of the rubber at large shear deflections is presented. Its predictions of structural accelerations and bearing displacement produced by design earthquakes and those above the design level are compared with those using a linear spring and dashpot model. A comparison has been made between two finite element analyses using MARC and ABAQUS of the force-deformation behaviour of a single disc of rubber bonded on both ...

1996-05-27

144

Hydrates in petroleum production : assessment of plug risk : project Hyperion enters its third and final year  

Energy Technology Data Exchange (ETDEWEB)

The Hyperion project was developed to determine an algorithm for assessing the risk of hydrate plug formation in the pipeline transport oil-water-gas mixtures at low temperatures. The project is a collaboration between physicists, chemists and engineers within the petroleum industry. This paper provided an overview of the project and outlined results obtained as the project entered its third and final year. The main objective of the project has been to understand the inherent mitigation effects of some oils on gas hydrate formation as well as to develop methods of predicting the risk of hydrate plugging. To date, the project has extracted and studied natural inhibiting components (NICs) in oils. Molecular modelling techniques have been used to study hydrate and fluid interfaces in order to estimate the driving force of agglomeration and growth through mechanical surface stress and measurement of surface wave fluctuations. A scheme is also being developed measure ...

2008-07-01

145

Architectural design criteria for f-block metal ion sequestering agents. 1998 annual progress report  

Energy Technology Data Exchange (ETDEWEB)

'The objective of this project is to provide a means to optimize ligand architecture for f-block metal recognition. The authors strategy builds on an innovative and successful molecular modeling approach in developing polyether ligand design criteria for the alkali and alkaline earth cations. The hypothesis underlying this proposal is that differences in metal ion binding with multidentate ligands bearing the same number and type of donor groups are primarily attributable to intramolecular steric factors. They propose quantifying these steric factors through the application of molecular mechanics models. The research involves close integration of theoretical and experimental chemistry. The experimental work entails synthesizing novel ligands and experimentally determining structures and binding constants for metal ion complexation by series of ligands in which architecture is systematically varied. The theoretical work entails using electronic structure calculations to ...

1998-12-31

146

Study of nanocrystallization in FINEMET alloy by active screen plasma nitriding  

International Nuclear Information System (INIS)

The nanocrystallization process of amorphous Fe_7_3_._5Si_1_3_._5B_9Nb_3Cu_1 was investigated by active screen plasma nitriding (ASPN) treatment at temperatures ranging from 410 "oC to 560 "oC for 3 h in two gas mixtures of 75% N_2-25% H_2 and 25% N_2-75% H_2 at 5 mbar atmosphere. The amorphous ribbons were then annealed under vacuum at the same time and temperatures mentioned above. The structure of the samples was analyzed using various techniques such as X-ray diffraction (XRD), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). Microhardness measurements, electrical resistivity and Vibrating Sample Magnetometer (VSM) were used to study mechanical, electrical and magnetic properties of the samples, respectively. It was observed that the ASPN treatment leads to finer grain size and higher crystalline volume fraction and modifies the structural features of Fe(Si) phase. The Fe(Si) lattice parameter for the nitrided ...

2010-02-18

147

Heat capacity of VT1-0 commercial titanium and VT5 and VT5-1 titanium base alloys at low temperature  

International Nuclear Information System (INIS)

The temperature dependences of the heat capacity of commercial titanium VT1-0 and alloys on its base, VT5 and VT5-1, have been derived in the temperature range of 4 to 290 K. For comparison, similar measurements have been conducted on pure titanium and specially prepared solid solutions on its base (Ti+3.7 at.% Al and Ti+0.82 at.% Sn). The measurement accuracy has been sufficient for comparing the results with calculation data. The obtained results are interpreted using the known concepts of the role of the mass of interstitial atoms and changes in the interatomic bond forces. It is shown that the phonon components of the molar heat capacities of solid solutions of Al in titanium have lower values in the entire temperature range, as compared to titanium. The corresponding differences are proportional to the Al concentrations. The lower molar heat capacity in the case of dissolution of Al is due to the low mass of the impurity ...

1978-01-01

148

A study of radiation embrittlement using simulation irradiation  

International Nuclear Information System (INIS)

Simulation irradiation experiments were carried out to investigate the formation processes and contribution to hardening of radiation-induced features in low alloy steels. Medium Cu (0.12 and 0.16%) and low Cu (0.03%) A533B steels were irradiated with 3 MeV Ni ions and 5 MeV electrons, and in KUR at 290degC. Irradiated steels were examined by three-dimensional atom probe, positron annihilation, high-resolution transmission electron microscopy and hardness measurements. Electron irradiation caused almost the same hardening as KUR irradiation in medium Cu steels under almost the same dose rate and dose conditions, whereas the formation of larger, denser and more Cu enriched clusters and smaller accumulation of single vacancies were confirmed for KUR irradiation. This indicated that cascade damage provides additional cluster nucleation sites to compensate for lower free point defect production. High dose rate Ni ion irradiation produced Mn-Ni-Si clusters and ...

2008-10-13

149

Deterministic loading of individual atoms to a high-finesse optical cavity  

CERN Document Server

Individual laser cooled atoms are delivered on demand from a single atom magneto-optic trap to a high-finesse optical cavity using an atom conveyor. Strong coupling of the atom with the cavity field allows simultaneous cooling and detection of individual atoms for time scales exceeding 15 s. The single atom scatter rate is studied as a function of probe-cavity detuning and probe Rabi frequency, and the experimental results are in good agreement with theoretical predictions. We demonstrate the ability to manipulate the position of a single atom relative to the cavity mode with excellent control and reproducibility.

2007-01-01

150

A Joint Committee on Intelligence: Proposals and Options ...  

Science.gov (United States)

... 3 Joint Committee on Atomic Energy as a Model . . . . . ... Joint Committee on Atomic Energy as a Model Page 8. CRS-4 ...

2004-08-25

151

Force-dependent chemical kinetics of disulfide bond reduction observed with single-molecule techniques  

UK PubMed Central (United Kingdom)

The mechanism by which mechanical force regulates the kinetics of a chemical reaction is unknown. Here, we use single-molecule force–clamp spectroscopy and protein engineering to study the effect...Full Text Available

2006-05-09

152

VERSION 2.1 - NASA Blogs  

Science.gov (United States)

Information superiority provides the Joint force a competitive ... Information Grid (GIG) as it matures and fills the needs of the Joint Task Force ... representatives from The Army Secretariat, Headquarters Department of Army ...

153

Units Data May29p  

Science.gov (United States)

... 2nd Battalion, 20th Special Forces Group, Company B ... Page 23. Headquarters, 29th Infantry Division, Joint Task Force-Augmentation ...

154

UnitData 9th Jan  

Science.gov (United States)

... Headquarters Element, Defense Logistics Agency, Support Detachment 3 ... Joint Task Force, Team 6 ... 19th Special Forces Group, Support Element 1 ...

155

Unit Data Sep 11thdd  

Science.gov (United States)

... 2nd Battalion, 20th Special Forces Group, Company B ... Headquarters, 29th Infantry Division, Joint Task Force-Augmentation ...

156

Unit Data Oct 23  

Science.gov (United States)

... 2nd Battalion, 20th Special Forces Group, Company B ... Headquarters, 29th Infantry Division, Joint Task Force-Augmentation ...

157

Unit Data July17  

Science.gov (United States)

... 2nd Battalion, 20th Special Forces Group, Company B ... Headquarters, 29th Infantry Division, Joint Task Force-Augmentation ...

158

Unit Data Feb 5o  

Science.gov (United States)

... 7th Joint Task Force Augmentation Team Schwetzingen ... Headquarters 85th Division Training Support, Detach 2 ... 20th Special Forces Company A ...

159

Unit Data Feb 19hl  

Science.gov (United States)

... United States Forces Command, Detachment 13 ... EUCOM Headquarters Support Detachment 1 ... 7th Joint Task Force Augmentation Team ...

160

Transforming Civil Engineering. Air Force Civil Engineer ...  

Science.gov (United States)

... Civil Engineering Page 2. ... 4. TITLE AND SUBTITLE Transforming Civil Engineering (Air Force Civil Engineer, Volume 15, Number 1, 2007) 5a. ...

2011-05-14

161

The Stryker Brigade Combat Team. Rethinking Strategic ...  

Science.gov (United States)

... For short-warning crises in other regions, Marine Expeditionary Units, the 82nd Airborne Division, Special Operations Forces, and Air Force/Navy ...

162

The Future of Amphibious Operations: Shaping the ...  

Science.gov (United States)

... WHS- Washington Headquarters Service. ... US Military (ie, Army, Navy, Air Force) service publications ... Strike Group to Fight in the Joint Task Force. ...

2010-02-01

163

Reforming Military Command Arrangements: The Case of the ...  

Science.gov (United States)

... WHS- Washington Headquarters Service. ... ie, Army, Navy, Air Force) service publications ... The Case of the Rapid Deployment Joint Task Force. ...

2011-03-01

164

Modern theory of nuclear forces: status and perspectives  

Energy Technology Data Exchange (ETDEWEB)

I present and discuss recent results on nuclear forces and few-nucleon systems obtained in the framework of chiral effective nuclear field theory.

2007-06-15

165

Integration of Armored Forces in the US Army Infantry Division  

Science.gov (United States)

... Infantry Division A Monograph by ... 5b. GRANT NUMBER 4. TITLE AND SUBTITLE Integration of Armored Forces in the US Army Infantry Division ...

2001-01-01

166

Effects of velocity-dependent force on the magnetic form factors of odd-Z  

International Nuclear Information System (INIS)

We investigate the effects of the velocity-dependent force on the magnetic form factors and magnetic moments of odd-Z nuclei. The form factors are calculated with the harmonic-oscillator wavefunctions. It is found that the contributions of the velocity-dependent force manifest themselves in the very large momentum transfer region (q?4 fm-1). In the low and medium q region the contributions of the velocity-dependent force are very small compared with those without this force. However, in the high-q region the contributions of the velocity-dependent force are larger than the normal form factors. The diffraction structures beyond the existing experimental data are found after the contributions of the velocity-dependent force are included. The formula of the correction to the single particle magnetic moment due to the velocity-dependent force is ...

2008-03-01

167

Download - NASA History Office  

Science.gov (United States)

Jan 14, 2004 ... presented to the nation at NASA Headquarters, Washington, D.C., ...... Board/Air Force Scientific Advisory Board Joint Task Force on ...

168

Deja vu: The Unified Command Plan of the Future Revisited  

Science.gov (United States)

... WHS- Washington Headquarters Service. ... The standing Joint Task Force concept should be used more to provide warfighter forces and ...

2011-05-19

169

DefenseLINK News: Department of Army General Officer ...  

Science.gov (United States)

... Staff for Policy, Supreme Headquarters, Allied Powers ... Command/United States Forces Korea, Korea, Commander, Joint Task Force for Full ...

170

Conversion of Selected Military Forces to the Use of Metric ...  

Science.gov (United States)

... This is the case for the 82nd Airborne Division ready brigade force (DRB) and the Military Airlift Command (MAC) strategic airlift system operating ...

1976-06-11

171

Computer-Aided Acquisition and Logistic Support Gateway ...  

Science.gov (United States)

... Army, Navy, Air Force Procedures (JANAP) 128 AUTODIN Operating Procedures. ... JANAP = Joint Army, Navy, Air Force Procedures ...

1989-09-01

172

Columbia Accident Investigation Board Documents - NASA  

Science.gov (United States)

Feb 6, 2003 ... Director, Plans and Programs, Headquarters Air Force Materiel Command, .... Commander of the Joint Task Force Southwest Asia at Prince ...

173

Calculation of electromagnetic force in electromagnetic forming process of metal sheet  

International Nuclear Information System (INIS)

Electromagnetic forming (EMF) is a forming process that relies on the inductive electromagnetic force to deform metallic workpiece at high speed. Calculation of the electromagnetic force is essential to understand the EMF process. However, accurate calculation requires complex numerical solution, in which the coupling between the electromagnetic process and the deformation of workpiece needs be considered. In this paper, an appropriate formula has been developed to calculate the electromagnetic force in metal work-piece in the sheet EMF process. The effects of the geometric size of coil, the material properties, and the parameters of discharge circuit on electromagnetic force are taken into consideration. Through the formula, the electromagnetic force at different time and in different positions of the workpiece can be predicted. The calculated electromagnetic ...

2010-06-15

174

An instrumented cylinder measuring pinch force and orientation  

UK PubMed Central (United Kingdom)

BackgroundThe function of a cylinder allowing simultaneous measurements of the opposition axis of the index finger and thumb of the hand and the magnitude of pinch force is described.Full Text Available

175

Fault detection by Turam TEM survey. Numerical model studies and a case history; TEM ho Turam sokutei haichi ni yoru danso kenshutsu no kokoromi. Model keisan to jisshirei  

Energy Technology Data Exchange (ETDEWEB)

With an objective to detect faults estimated to exist along the Shigesumi valley in the Kamioka mine, discussions were given by using electromagnetic survey, which uses the Turam measurement arrangement based on the TEM method, and three-dimensional model calculations. The Turam measurement arrangement, which installs transmission loop fixedly, is used to identify nature and distribution of electrically conductive objects upon noticing abnormal portions in magnetic fields in the measurement data. In the model calculation, the plate model calculation method and the FDTD method were used, and so was the calculation code TEM3DL. The result revealed that strong topographical influence is seen from steep V-shaped valley existing along the traverse line in the measurement data, but an abnormal resistivity band accompanying remarkable distortion in the curve was detected. According to the result of the model calculation, anomaly detection may be found difficult in ...

1997-05-27

176

CT appearances of unilateral cleft palate 20 years after bone graft surgery  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To describe CT appearances in patients with unilateral cleft lip and palate (CLP) 20 years after bone graft surgery. Material and Methods: Eighteen consecutive patients with unilateral CLP were examined. All patients had been treated with primary closure, both in infancy and early childhood, supplemented with bone grafting at the age of around 10 years. The CT examination of the upper jaw included a dental CT program. The CT appearances of the cleft side were compared with those of the untreated non-cleft side. Results: Abnormal CT appearances included skew nasal aperture (n=17), nasal septal deviation (n=17), low floor of nasal aperture (n=15) at or towards the cleft side, and deviation of anterior nasal spine towards the non-cleft side (n=18). The posterior part of the bone cleft was visible in all patients, and the dental arch was V-shaped in 8. Conclusion: Although adherence to the present treatment protocol is considered to give satisfactory ...

2002-11-01

177

CT appearances of unilateral cleft palate 20 years after bone graft surgery  

International Nuclear Information System (INIS)

Purpose: To describe CT appearances in patients with unilateral cleft lip and palate (CLP) 20 years after bone graft surgery. Material and Methods: Eighteen consecutive patients with unilateral CLP were examined. All patients had been treated with primary closure, both in infancy and early childhood, supplemented with bone grafting at the age of around 10 years. The CT examination of the upper jaw included a dental CT program. The CT appearances of the cleft side were compared with those of the untreated non-cleft side. Results: Abnormal CT appearances included skew nasal aperture (n=17), nasal septal deviation (n=17), low floor of nasal aperture (n=15) at or towards the cleft side, and deviation of anterior nasal spine towards the non-cleft side (n=18). The posterior part of the bone cleft was visible in all patients, and the dental arch was V-shaped in 8. Conclusion: Although adherence to the present treatment protocol is considered to give satisfactory ...

2002-11-01

178

Effect of co- and counter-swirl on the isothermal flow- and mixture field of a double-airflow burner; Einfluss gleich- und gegensinniger Verdrallung auf das isotherme Stroemungs- und Mischungsfeld eines luftseitig zweiflutigen Brenners  

Energy Technology Data Exchange (ETDEWEB)

Atomization of liquid fuel in aircraft engines requires application of airblast atomizers, where the kerosene is supplied into the shear layer between two swirling airstreams. The transfer of this functional principle towards gaseous fuel, as illustrated in Fig. 1, yielded a strong influence of the swirl arrangement of the airflows on flame stability and homogeneity of the fuel/air-mixture. Compared to the co-swirl configuration the flow field of the counter-swirl arrangement exhibits a marked increase of the mass flow recirculated in the internal recirculation zone and a reduction of its length in axial direction. This is attributed to the faster decay of tangential velocity maxima in case of counter-rotating airflows. This generates a stronger positive axial pressure gradient dp/dx, thus enhancing the internal recirculation zone. Analysis of local turbulence quantities yields a restriction of turbulent exchange to smaller radial sections and ...

2002-11-01

179

Experimental research of spontaneous evolution from ultracold rydberg atoms to plasma  

International Nuclear Information System (INIS)

The spontaneous evolution from ultracold Rydberg atoms to plasma is investigated in a caesium MOT by using the method of field ionization. The plasma transferred from atoms in different Rydberg states (n=22-32) are obtained experimentally. Dependence of the threshold time of evolving to plasma and the threshold number of initial Rydberg atoms on the principal quantum number of initial Rydberg states is studied. The experimental results are in agreement with hot-cold Rydberg-Rydberg atom collision ionization theory. (authors)

2008-04-01

180

Cooperative spontaneous emission from two different atoms  

International Nuclear Information System (INIS)

The total radiation rate, angular distribution of the emitted energy and photon correlations of the cooperative spontaneous radiation from two atoms with different resonance frequencies and spontaneous decay rates are calculated. Contrary to the case of two identical atoms oscillations appear in the total radiation rate and the spatial distribution of the total number of emitted photons differs from the single-atom radiation pattern. The effect of the dipole-dipole near-field interaction on the time evolution of the atomic system is discussed. (author).

1986-01-01

181

The Grounds For Time Dependent Market Potentials From Dealers' Dynamics  

CERN Document Server

We apply the potential force estimation method to artificial time series of market price produced by a deterministic dealer model. We find that dealers' feedback of linear prediction of market price based on the latest mean price changes plays the central role in the market's potential force. When markets are dominated by dealers with positive feedback the resulting potential force is repulsive, while the effect of negative feedback enhances the attractive potential force.

2007-01-01

182

Sustaining Operational Maneuver in the Twenty-First Century  

Science.gov (United States)

... and the Commonwealth forces launched Operation GOODWOOD in an attempt to break through the German lines. In the ...

2010-05-13

185

Realistic and Affordable Cyberware Opponents for the ...  

Science.gov (United States)

... Therefore, as the information management capabilities of military forces increase, there is a corresponding need for improved security for the ...

2003-06-01

188

Initial Evaluation of USAF Security Forces Distributed Mission Training (SecForDMT).  

Science.gov (United States)

United States Air Force security forces have a central role in force protection. Their missions include military police services, installation security, air base defense, military working dog functions, and combat arms training and maintenance. Surveys in...

2004-01-01

189

How the Air Force Should Stay Engaged in Computer Vision ...  

Science.gov (United States)

... 14 Face Detection ..... 14 Automated Mapping ...

2007-04-01

191

Calculations and analysis of the eddy current braking force  

International Nuclear Information System (INIS)

This work presents analsysi of the eddy current brake. It presents a new formula for the braking force when the actual width of the pole is considered. This formula is suitable for both thin and thick discs and may be employed for wide range of working speed. This force is obtained by solving a two dimensional field problem for magnetic vector potential and then by employing Lorentz force equation. A comture program is constructed to calculate the braking force and to study the effect of various factors influencing the brake performance. The results are summarised in a group of curves which may be useful for design purposes.

192

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

193

Surface energy of semiconductors covered with thin layers of various materials  

International Nuclear Information System (INIS)

Surface energy of III-V semiconductors ended by (110) clean surface and surface covered by atomic monolayer of aluminium, copper and sulfur has been calculated. We have used the Greens-function technique based on the scheme of linear muffin-tin orbitals in the atomic sphere approximation (LMTO-ASA) for the crystal potential and width the local density approximation (LDA) for electrons. Two types of coverage are considered: full monolayer with two additional atoms per two-dimensional unit cell and half monolayer with one additional atom per unit cell. Full monolayer of metallic atoms increases the surface energy. Cu atoms lead to greater destabilization than Al atoms. Sulfur atoms stabilize (110) surface for all considered compounds. (author)

1997-09-23

194

Strong-interaction effect measurements in sigma hyperonic atoms of W and Pb  

Energy Technology Data Exchange (ETDEWEB)

Strong-interaction effects have been observed in the x-ray spectra of atoms formed with [Sigma][sup [minus

1993-03-01

195

Spontaneous excitation of an accelerated atom in a spacetime with a reflecting plane boundary  

Science.gov (United States)

We study a two-level atom in interaction with a real massless scalar quantum field in a spacetime with a reflecting boundary. The presence of the boundary modifies the quantum fluctuations of the scalar field, which in turn modifies the radiative properties of atoms. We calculate the rate of change of the mean atomic energy of the atom for both inertial motion and uniform acceleration. It is found that the modifications induced by the presence of a boundary make the spontaneous radiation rate of an excited inertial atom oscillate near the boundary and this oscillatory behavior may offer a possible opportunity for experimental tests for geometrical (boundary) effects in flat spacetime. While for accelerated atoms, the transitions from ground states to excited states are found to be possible even in a vacuum due to changes in the vacuum fluctuations induced by ...

2005-09-15

198

K-matix theory in relation to MQDT and applications to atomic spectra  

Energy Technology Data Exchange (ETDEWEB)

A summary of the basic principles of K-matrix theory and examples of its applications to atomic spectra are discussed. (AIP)

1990-04-01

199

X-ray ablation measurements and modeling for ICF applications  

Energy Technology Data Exchange (ETDEWEB)

X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both target yield and hohlraum wall thickness are also described. Experiments have been ...

1996-09-01

200

Thermal annealing effect on optical properties of electrodeposited ZnO thin films  

Energy Technology Data Exchange (ETDEWEB)

ZnO thin films were electrodeposited in aqueous solution on gilded p-type Si wafer substrates. Thermal treatments were carried out on different films in Ar atmosphere at different temperatures, between 200 and 600 {sup 0}C. Surface morphology studies using scanning electron microscopy and atomic force microscopy show a smooth surface for an annealing temperature of 400 {sup 0}C with a roughness mean square value of about 15 nm and a precipitation of ZnO microcrystals on the deposit surface at 600 {sup 0}C. X-ray diffraction experiments reveal a decrease in the c-parameter value from 5.223 to 5.206 A after treatment at 600 {sup 0}C, due to the removal of hydrogen from the film. Raman spectroscopy analyses show an improvement in the crystal quality of the film and a decrease in the compressive stress inside the deposit. Photoluminescence observations reveal an important change in the UV emission band after annealing at 200 {sup 0}C. A visible ...

2008-10-07

201

Synthesis of colloidal silver iron oxide nanoparticles--study of their optical and magnetic behavior.  

Science.gov (United States)

Silver iron oxide nanoparticles of fairly small size (average diameter approximately 1 nm) with narrow size distribution have been synthesized by the interaction of colloidal beta- Fe2O3 and silver nanoparticles. The surface morphology and size of these particles have been analyzed by using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Their structural analysis has been carried out by employing x-ray diffraction (XRD), selected-area electron diffraction (SAED), optical and infrared (IR) spectroscopic techniques. The ageing of these particles exhibits the formation of self-assembly, possibly involving weak supramolecular interactions between Ag(I)O4 and Fe(III)O4 species. These particles display the onset of absorption in the near-infrared region and have higher absorption coefficient in the visible range compared to that of its precursors. Magnetic measurements ...

2009-07-01

202

Surface Roughness of Stainless Steel Bender Mirrors for FocusingSoft X-rays  

Energy Technology Data Exchange (ETDEWEB)

We have used polished stainless steel as a mirror substrate to provide focusing of soft x-rays in grazing incidence reflection. The substrate is bent to an elliptical shape with large curvature and high stresses in the substrate require a strong elastic material. Conventional material choices of silicon or of glass will not withstand the stress required. The use of steel allows the substrates to be polished and installed flat, using screws in tapped holes. The ultra-high-vacuum bender mechanism is motorized and computer controlled. These mirrors are used to deliver focused beams of soft x-rays onto the surface of a sample for experiments at the Advanced Light Source (ALS). They provide an illumination field that can be as small as the mirror demagnification allows, for localized study, and can be enlarged, under computer control,for survey measurements over areas of the surface up to several millimeters. The critical issue of the quality of the steel surface, polished and coated with ...

2005-10-11

203

Spectroscopic and electrochemical characterisation of thin cathodic plasma polymer films on iron  

International Nuclear Information System (INIS)

Complimentary spectroscopic, microscopic and electrochemical studies were performed to characterise the barrier properties as well as the interface structure of model iron substrates covered with thin plasma polymer films. Cathodic plasma polymers were deposited which show high barrier properties. The metal surface was pre-treated by a reducing or oxidising plasma. This allowed the adjustment of the oxidation state of the interface layer. The interface structure was characterised by means of X-ray photoelectron sputter profiles, infrared spectroscopy and the application of a Kelvin probe. The investigations show that the measured Voltapotential on the plasma polymer surface can be correlated with the oxidation state of the interface. Reducing plasmas lead to an almost oxide free surface. After deposition of the plasma polymer, this reduced state of the oxide is sensitive to re-oxidation of the interface by oxygen that diffuses through the plasma polymer. It could be shown that the ...

2004-05-15

204

Solution processable fluorenyl hexa-peri-hexabenzocoronenes in organic field-effect transistors and solar cells  

Energy Technology Data Exchange (ETDEWEB)

The organization of organic semiconductor molecules in the active layer of organic electronic devices has important consequences to overall device performance. This is due to the fact that molecular organization directly affects charge carrier mobility of the material. Organic field-effect transistor (OFET) performance is driven by high charge carrier mobility while bulk heterojunction (BHJ) solar cells require balanced hole and electron transport. By investigating the properties and device performance of three structural variations of the fluorenyl hexa-peri-hexabenzocoronene (FHBC) material, the importance of molecular organization to device performance was highlighted. It is clear from {sup 1}H NMR and 2D wide-angle X-ray scattering (2D WAXS) experiments that the sterically demanding 9,9-dioctylfluorene groups are preventing {pi}-{pi} intermolecular contact in the hexakis-substituted FHBC 4. For bis-substituted FHBC compounds 5 and 6, {pi}-{pi} intermolecular contact was observed in ...

2010-03-24

205

Shape control of CeO{sub 2} nano-particles and synthesis of nano-metric solid acid SO{sub 4}{sup 2-}/CeO{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

Nano-particles of CeO{sub 2} with the smallest average particle size (18.7 nm) and spherical morphology were obtained from a mixture solution of Ce(NO{sub 3}){sub 3}{center_dot}6H{sub 2}O, citric acid, polyvinyl alcohol by an auto-combustion process exploiting sol-gel as precursors. The course of size control and shape control by polyvinyl alcohol was examined in detail. A transmission electron microscopy (TEM) and an atomic force microscopy (AFM) were employed to characterize the particle-size and morphology of CeO{sub 2} particles. In addition, a sort of nano-metric solid acid SO{sub 4}{sup 2-}/CeO{sub 2} based on CeO{sub 2} nano-particles was prepared by macerating, filtering, drying and calcining processes. The particle-size of SO{sub 4}{sup 2-}/CeO{sub 2} was also assessed by TEM. The composition of SO{sub 4}{sup 2-}/CeO{sub 2} was analyzed by X-ray diffraction (XRD) and infrared spectra (IR). The influencing factors in the formation of ...

2003-12-20

206

Rare-earth mixed oxide thin films as 100% lattice match buffer layers for YBa2Cu3O7-x coated conductors  

International Nuclear Information System (INIS)

Buffer layers with 100% lattice match with YBa2Cu3O7 - ? (YBCO) were prepared from mixed rare-earth-oxides applying a simple sol-gel process and dip-coating method. Structural analysis of the sol-gel derived powder by X-ray diffraction revealed that the mixing parameter, which eliminates the lattice mismatch with YBCO, is x = 0.2382, 0.1852, 0.1252, 0.0906, 0.0793 and 0.0395 in (Eu1 - xHox)2O3, (Eu1 - xErx)2O3, (Eu1 - xYbx)2O3, (Gd1 - xHox)2O3, (Gd1 - xYx)2O3 and (Gd1 - xYbx)2O3, respectively. Microstructural investigations were carried out for Gd1.819Ho0.181O3 films epitaxially grown on cube-textured Ni (100) substrates by sol-gel dip-coating process. X-ray diffraction of the buffer showed strong out-of-plane orientation on Ni tape. The (Gd1 - xHox)2O3 (222) pole figure indicated a single cube-on-cube textured structure. The omega and phi scans revealed good out-of-plane and in-plane alne alignments. The full-width at half-maximum values of omega and phi scan of (Gd1 - xHox)2O3 films ...

2010-04-02

207

Quantum molecular dynamics and molecular interactions studied by NMR and INS[Nuclear magnetic resonance; Proton tunnelling; Hydrogen bond  

Energy Technology Data Exchange (ETDEWEB)

The wavefunction of a particle extends into the classically forbidden barrier region of the potential energy surface. The consequence of this partial delocalisation is the phenomenon of quantum tunnelling, an effect which enables a particle to penetrate a potential barrier of magnitude greater than the energy of the particle. The tunnelling probability is an exponential function of the particle mass. The effect is therefore an important contribution to the behaviour of light atoms, in particular the proton. The hydrogen bond has long been appreciated to be an essential component of many biological and chemical systems, and the proton transfer reaction in the hydrogen bond is fundamental to many of these processes. The proton behaviour in the hydrogen bonds of benzoic acid, acetylacetone and calix-4-arene has been studied. A variety of techniques, both experimental and computational, were adopted for the study of the three hydrogen bonded systems. The complementary ...

2002-07-01

208

Peroxi-coagulation degradation of C.I. Basic Yellow 2 based on carbon-PTFE and carbon nanotube-PTFE electrodes as cathode  

International Nuclear Information System (INIS)

The electrochemical treatment of solutions containing C.I. Basic Yellow 2 (BY2) in aqueous solutions with carbon-PTFE (polytetrafluoroethylene) and carbon nanotube (CNT)-PTFE electrodes as cathode has been studied. The fabricated electrodes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The amount of electrogenerated H2O2 on the surface of these electrodes was investigated, too. The results showed that the amount of H2O2 obtained with the CNT-PTFE electrode was nearly three times higher than that of carbon-PTFE electrode. The decolorization efficiency of BY2 in peroxi-coagulation process reached 62% and 96% in the first 10 min by carbon-PTFE and CNT-PTFE electrodes at 100 mA, respectively. The effect of operational parameters such as applied current, initial pH and initial dye concentration was studied in an attempt to reach higher decolorization efficiency. The degradation and mineralization of BY2 ...

2009-11-01

209

Organic light-emitting devices based on solution-processible quinolato-complex supramolecules  

International Nuclear Information System (INIS)

This paper discusses a new type of supramolecular material tris{5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl) aminesulfonyl-8-hydroxyquinolato} aluminum(III), Al(SCarq)3, which we synthesized using three 5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl) aminesulfonyl-8-hydroxyquinoline as bidentate ligands. The peak photoluminescence in the solid phase appears at 488 nm. In cyclic voltammetric measurement, two oxidation peaks, which were obtained at -5.6 and -5.9 eV, correspond to HOMO sites of carbazoyl and aluminum quinolates, respectively. In the investigation of solid morphological thin film, the flat surface was investigated using an atomic force microscope. The root mean square (rms) and mean roughness (Ra) were respectively measured to be 0.427 and 0.343 nm. For the fabrication of organic light-emitting devices (OLEDs) using spin-coating techniques, the turn-on voltage and maximum luminescence of the optimized electroluminescence ...

2009-02-15

210

Korean experience in CANDU-PHWR operation  

Science.gov (United States)

Among KEPCO's 9 nuclear power units, Korea Nuclear Unit No. 3, the Wolsung Nuclear Power Plant is the only CANDU-PHWR Unit, while the rest of 8 others are PWR units. The unit was designed by Atomic Energy of Canada, Ltd. of Canada, who also performed overall project management for the plant construction under the provisions and arrangement of the relevant contracts. The gross electrical output of the plant is 678.7 MWe and thermal output of the reactor is 2061 MWth. While these figures lead to lower plant efficiency than LWR counterparts, unit energy cost for fuel is more favorable than LWRs because natural uranium is utilized for the fuel bundles, some of which are already being fabricated domestically. Annual capacity factors for 1983 and 1984 could have been improved, if two major planned outages for the modification works on steam generator internals and one major forced outage from the heavy water spill incident could be ...

1988-01-01

211

High temperature oxidation of metals: vacancy injection and consequences on the mechanical properties; Consequences de l'oxydation haute temperature sur l'injection de defauts et le comportement mecanique des materiaux metalliques  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to account for the effects of the high temperature oxidation of metals on their microstructure and their mechanical properties. 'Model' materials like pure nickel, pure iron and the Ni-20Cr alloy are studied. Nickel foils have been oxidised at 1000 C on one side only in laboratory air, the other side being protected from oxidation by a reducing atmosphere. After the oxidation treatment, the unoxidized face was carefully examined by using an Atomic Force Microscope (AFM). Grain boundaries grooves were characterised and their depth were compared to the ones obtained on the same sample heat treated in the reducing atmosphere during the same time. They are found to be much deeper in the case of the single side oxidised samples. It is shown that this additional grooving is directly linked to the growth of the oxide scale on the opposite side and that it can be explained by the diffusion of the vacancies ...

2004-11-15

212

Grain boundary corrosion of copper canister material  

Energy Technology Data Exchange (ETDEWEB)

The proposed design for a final repository for spent fuel and other long-lived residues in Sweden is based on the multi-barrier principle. The waste will be encapsulated in sealed cylindrical canisters, which will then be placed in granite bedrock and surrounded by compacted bentonite clay. The canister design is based on a thick cast inner container fitted inside a corrosion-resistant copper canister. During fabrication of the outer copper canisters there will be some unavoidable grain growth in the welded areas. As grains grow they will tend to concentrate impurities within the copper at the new grain boundaries. The work described in this report was undertaken to determine whether there is any possibility of enhanced corrosion at grain boundaries within the copper canister. The potential for grain boundary corrosion was investigated by exposing copper specimens, which had undergone different heat treatments and hence had different grain sizes, to aerated artificial ...

2001-03-01

213

Enzyme-induced growth of silver nanoparticles studied on single particle level  

Energy Technology Data Exchange (ETDEWEB)

Based on their interesting properties, metal nanoparticles show the potential as an analytical tool in electronic (Burmeister et al. 2004), optical (Yguerabide and Yguerabide 1998), and catalytic applications (Liu 2006). Their characteristics depend on the composition, shape, and size of the single particles. These various properties are utilized in many different approaches such as optics, magnetics (Lang et al. 2007), and laser technology (Csaki et al. 2007). We investigated an alternative method for the synthesis of nanoparticles. In this case, an enzyme, horseradish peroxidase, induces a silver deposition and replaces a metal nanoparticle as the reaction seed. Depending on the reaction time, we could obtain particles in a range of few nanometers up to more than 250 nm. For a better understanding of the enzymatic silver deposition process, the silver particles produced by this process were analyzed by SEM, TEM, and atomic force microscopy ...

2009-05-15

214

Enhanced corrosion resistance by sol-gel-based ZrO_2-CeO_2 coatings on magnesium alloys  

International Nuclear Information System (INIS)

The physical, chemical and mechanical properties of magnesium alloys make them attractive materials for automotive and aerospace applications. However, these materials are susceptible to corrosion and wear. This work discusses the potential of using sol-gel based coatings consisting of ZrO_2 and 15 wt.% of CeO_2. The CeO_2 component provides enhanced corrosion protection, while ZrO_2 impart corrosion as well as wear resistance. Coating deposition was performed by the dip coating technique on two magnesium alloy substrates with different surface finishes: AZ91D (as-casted, sand-blasted, and machined) and AZ31 (rolled and machined). All as-deposited coatings (xerogel coatings) were then subjected to 10 h annealing: a temperature of 180 C was applied to the AZ91D alloy and 140 C to the AZ31 alloy. Morphological and structural properties of the annealed coatings were investigated by scanning electron microscopy, atomic force microscopy and ...

2005-02-01

215

Crystal growth of epitaxial CVD diamond using [sup 13]C isotope and characterization of dislocations by Raman spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

[sup 13]C epitaxial diamond films have been grown on [sup 12]C-type IIb diamond substrates doped with boron, using electron assisted chemical vapor deposition. The relation between etch pits to dislocations in [sup 13]C diamond film and the broadening of the first-order Raman peak was examined. The reactant gas was [sup 13]CH[sub 4] of > 99% purity. The substrate temperature was varied from 943 to 1300 C. The uneven surface morphology was confirmed by atomic force microscopy (AFM) and laser microscopy. From 943 to 1030 C, etch pit rows along left angle 100 right angle were observed. At 991 C, the etch pit density on a row was 3300 to 5000 pits/cm. The Ar[sup +] laser beam was focused on a transparent area near the row of etch pits, where the boron impurity of the substrate is less than several 10 ppm. The first-order Raman line of [sup 13]C epitaxial diamond film was broadened to 3.6-4.0 cm[sup -1]. The line broadening was 50-90% compared ...

1993-03-01

216

Comparison of plasma chemistries for inductively coupled plasma etching of InGaAlP alloys  

Science.gov (United States)

Two plasma chemistries, i.e., CH{sub 4}/H{sub 2}/Ar and Cl{sub 2}/Ar, were compared for the etching of InGaP, AlInP, and AlGaP under inductively coupled plasma (ICP) conditions. While the etching with CH{sub 4}/H{sub 2}/Ar discharges appears to be ion driven, Cl{sub 2}/Ar discharges showed an additional strong chemical enhancement. The highest etch rate ({approximately}1 {mu}m/min) for InGaP was achieved at high ICP source power ({ge}750 W) with the Cl{sub 2}/Ar chemistry. Cl{sub 2}/Ar discharges provided very smooth surfaces in all three materials with root-mean-square roughness measured by atomic force microscopy around 2 nm. This result may be due to the efficient ion-assisted product desorption in this chemistry. The etched near-surface region of InGaP ({approximately}100 {Angstrom}) with Cl{sub 2}/Ar maintained almost the same stoichiometry as that of the unetched control. By contrast, the CH{sub 4}/H{sub 2}/Ar plasma chemistry produced ...

1998-05-01

217

Responses to comments received on the draft final report of the Secretary of Energy Advisory Board Task Force on Radioactive Waste Management  

Energy Technology Data Exchange (ETDEWEB)

The Task Force solicited comments on its Draft Final Report from a variety of sources. Letters were sent to over 400 individuals who had expressed interest in the interest in the Department`s radioactive waste, management programs, a notice was placed in the Federal Register, the morning session of the January 1993 meeting of the full Secretary of Energy Advisory Board was given over to discussion of the draft, and Task Force members and staff presented the effort at several professional meetings. Altogether 32 written comments were received. They are reproduced here, followed in each case by the Task Force`s response to specific suggestions made to improve the draft. (The panel did not respond to comments that simply reflected policy preferences or that praised the group`s effort.) With one exception, those specific suggestions are highlighted and given a letter designation from {open_quotes}A{close_quotes} to ...

1994-10-01

218

Aerodynamic effects of flexibility in flapping wings.  

Science.gov (United States)

Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re approximately 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of ...

2009-08-19

219

Blowdown thrust force under pipe rupture accident. Pt. 1. Experimental evaluations of blowdown thrust force and decompression characteristics  

Energy Technology Data Exchange (ETDEWEB)

Blowdown thrust forces and decompression characteristics were evaluated concerning the jet discharge or pipe whip tests with a 4-inch or 6-inch diameter pipe under PWR LOCA or BWR LOCA conditions related to pipe rupture accidents in nuclear power plants. This paper presents experimental evaluations of time-dependent and maximum blowdown thrust forces, and evaluations of decompression characteristics under instantaneous pipe rupture conditions. The following items are discussed: the peak value of the blowdown thrust force, the jet thrust coefficient for the maximum blowdown thrust force, the pressure recovery after break, and the relationship between the pressure undershoot of the sudden decompression and the decompression rate.

1984-06-01

220

The influence of an intramolecular H-bond on the adsorption of sulfur-containing amino acids on graphitized thermal carbon black  

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption of sulfur-containing amino acids and their derivatives on the surface of graphitized thermal carbon black were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the S atom in amino acids and the graphite C atom were determined. It was shown that an intramolecular H-bond influenced the adsorption of amino acids on the surface of graphitized thermal carbon black.

2009-01-01

221

The influence of an intramolecular H-bond on the adsorption of sulfur-containing amino acids on graphitized thermal carbon black  

Science.gov (United States)

The thermodynamic characteristics of adsorption of sulfur-containing amino acids and their derivatives on the surface of graphitized thermal carbon black were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the S atom in amino acids and the graphite C atom were determined. It was shown that an intramolecular H-bond influenced the adsorption of amino acids on the surface of graphitized thermal carbon black.

2009-04-01

222

Preparation of Cluster States for Many Atoms in Cavity QED  

International Nuclear Information System (INIS)

We propose a scheme for the generation of the cluster states for many atoms in cavity QED. In our scheme, the atoms are sent through nonresonant cavity fields in the vacuum states. The cavity fields are only virtually excited and no quantum information will be transferred from the atoms to the cavity fields. The advantage is that the cavities are suppressed during the procedure. The scheme can also be generalized to the ion trap system.

2007-07-15

223

Nature of the short-range interaction between noble gas atoms and metal surfaces  

Energy Technology Data Exchange (ETDEWEB)

I propose that an interpretation of the interaction of noble gas atoms with metal surfaces as predominantly physisorbing provides the best explanation for the systematics of their binding energies and surface dipoles, as well as for the tendency of noble gas atoms to bind in low coordinated sites. In the present context physisorption is defined as a process driven by the overlap of the electrostatic atomic potentials of the interacting species. (orig.)

2007-06-15

224

Evaluation of corrosion of dissolver for enriched uranium  

International Nuclear Information System (INIS)

... Hayashi, Shinichiro Japan Atomic Energy Agency, Tokai, Ibaraki (Japan)

2007-10-01

225

Calculation of henry constants for the adsorption of isomeric phenylenediamines on graphitized thermal carbon black  

British Library Electronic Table of Contents (United Kingdom)

Henry constants for the adsorption of o- and p-phenylenediamines on the surface of graphitized thermal carbon black within the temperature range 433?479 K were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the nitrogen atom in aniline and isomeric phenylenediamines and the carbon atom of the basal face of graphite were determined. It was shown that an intramolecular H bond influenced the geometry and adsorption properties of o-phenylenediamine.

2009-01-01

226

Calculation of henry constants for the adsorption of isomeric phenylenediamines on graphitized thermal carbon black  

Science.gov (United States)

Henry constants for the adsorption of o- and p-phenylenediamines on the surface of graphitized thermal carbon black within the temperature range 433-479 K were calculated by the molecular statistical method. The parameters of the atom-atom potential function of intermolecular interaction between the nitrogen atom in aniline and isomeric phenylenediamines and the carbon atom of the basal face of graphite were determined. It was shown that an intramolecular H bond influenced the geometry and adsorption properties of o-phenylenediamine.

2009-12-01

227

Basic physics of radiotracers  

Energy Technology Data Exchange (ETDEWEB)

This two-volume reference uses many equations to provide detailed information on atomic and nuclear decay phenomena.

1983-01-01

228

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

229

Effects of confinement on the permanent electric-dipole moment of Xe atoms in liquid Xe  

CERN Document Server

Searches for permanent electric-dipole moments (EDM) of atoms provide important constraints on competing extensions to the standard model of elementary particles. Recently proposed experiment with liquid $^{129}$Xe [M.V. Romalis and M.P. Ledbetter, Phys. Rev. Lett. \\textbf{87}, 067601 (2001)] may significantly improve present limits on the EDMs. To interpret experimental data in terms of CP-violating sources, one must relate measured atomic EDM to various model interactions via electronic-structure calculations. Here we study density dependence of atomic EDMs. The analysis is carried out in the framework of the cell model of the liquid coupled with relativistic atomic-structure calculations. We find that compared to an isolated atom, the EDM of an atom of liquid Xe is suppressed by about 40%.

2004-01-01

230

Atomic mechanism of glass-to-liquid transition in simple monatomic glasses  

British Library Electronic Table of Contents (United Kingdom)

The atomic mechanism of a glass-to-liquid transition in a monatomic Lennard-Jones (LJ) glass was studied using the molecular dynamics (MD) method. Glassy models were heated up from low temperature at two different heating rates and a glass-to-liquid transition found to occur at the higher heating rate. The temperature dependence of the potential energy, mean-squared-displacements (MSD) of the atoms and the self-intermediate scattering function indicate clearly that a glass transition occurs in the system. The atomic mechanism of the glass-to-liquid transition was investigated by analyzing the spatio-temporal arrangement of liquid-like atoms in the system upon heating. Liquid-like atoms were detected using the Lindemann-melting-like criterion. Upon heating, liquid-like atoms occur at temper...

2011-01-01

231

University of Tennessee deploys force10 switch for CERN work  

CERN Multimedia

"Force20 networks, the pioneer in building and securing reliable networks, today announced that the University of Tennessee physics department has deployed the C300 resilient switch to analyze data form CERN's Large Hadron Collider." (1/2 page)

2007-01-01

232

Unit Data Jan 8b  

Science.gov (United States)

... Headquarters 5th Brugade 78th Division (Ts) ... 2nd Battalion 20th Special Forces Company B ... 29th Corps Personnel Serves Hq Joint Task Force Aug ...

233

US Air Force Aircraft in Southeast Asia Tested by the Air Force ...  

Science.gov (United States)

... feet in length, and 26 feet 2 inches high. The AC-119G and AC-119K, are powered with two General Electric J85-17 jet engines pod-mounted ...

1970-03-01

234

Rubella screening and vaccination program for US Air Force trainees: an analysis of findings.  

UK PubMed Central (United Kingdom)

A preventive medicine program of rubella control for trainees at the Air Force Military Training Center, Lackland AFB, Texas, was begun in October 1977. Incoming trainees were screened for rubella susceptibility,...Full Text Available

1982-03-01

235

QSAR Studies of Copper Azamacrocycles and Thiosemicarbazones  

UK PubMed Central (United Kingdom)

Genetic algorithms (GA) were used to develop specific copper metal-ligand force field parameters for the MM3 force field, from a combination of crystallographic structures and ab initio...Full Text Available

2005-08-25

236

Novel Technique for Aerodynamic Force Measurement in Shock Tubes.  

Science.gov (United States)

For aerodynamic force measurement in the ISL shock tunnel, the authors have developed a novel measurement technique. Its key feature is a mounting support, which releases the test model and tightens it again after a free flight duration of 10 to 15 millis...

1989-01-01

237

Nonlinear time-periodic models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria  

UK PubMed Central (United Kingdom)

Previous studies of insect flight control have been statistical in approach, simply correlating wing kinematics with body kinematics or force production. Kinematics and forces are linked by Newtonian...Full Text Available

2005-06-22

238

Muscle Forces or Gravity: What Predominates Mechanical Loading on Bone?  

UK PubMed Central (United Kingdom)

Most mechanical forces acting on the skeleton are generated either through impact with the ground (i.e., gravitational loading) or through muscle contractions (i.e., muscle loading). If one...Full Text Available

2009-11-01

239

Mechanism of Catch Force: Tethering of Thick and Thin Filaments by Twitchin  

UK PubMed Central (United Kingdom)

Catch is a mechanical state occurring in some invertebrate smooth muscles characterized by high force maintenance and resistance to stretch during extremely slow relaxation. During catch, intracellular...Full Text Available

2010-01-01

240

Markets and commercialization scenarios for emerging fuel cells in evolving electricity markets  

Energy Technology Data Exchange (ETDEWEB)

Electricity markets in the United States are undergoing unprecedented structural changes as a result of the confluence of regulatory, competitive, and technological forces. This paper introduces these structural changes and forces and discuss the implications, markets and commercialization scenarios for emerging fuel cells in evolving US electricity markets.

1996-12-31

241

Magnetic Levitation of MC3T3 Osteoblast Cells as a Ground-Based Simulation of Microgravity  

UK PubMed Central (United Kingdom)

Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances...Full Text Available

2009-11-01

242

Longitudinal Forces Required with Loose Liner Barrel Construction.  

Science.gov (United States)

A previous study demonstrated the advantages that could be obtained in using loose liner naval gun barrel construction, particularly if the liner is autofrettaged. This report deals with the longitudinal forces required to assemble and disassemble such co...

1969-01-01

243

Learning the Hard Way: Force Protection 1983-2000.  

Science.gov (United States)

The October 2000 terrorist attack on the guided-missile destroyer USS Cole (DDG 67) in the port of Aden, Yemen, is commonly viewed in the larger context of al-Qa'ida's September 11th campaign. Beyond the initial official investigations, the military force...

2009-01-01

244

Joint Task Force Headquarters Master Training Guide.  

Science.gov (United States)

The purpose of the Joint Task Force Headquarters Master Training Guide (JTF HQ MTG) is to provide a descriptive, performance-oriented training guide to assist leaders in training their units. It also serves as a guide for the JTF Headquarters in actual op...

2003-01-01

245

Influence of geometry and operating conditions of a centrifugal compressor stage on the radial gas force  

British Library Electronic Table of Contents (United Kingdom)

The influence of geometry and operating conditions of the centrifugal compressor stage on the radial gas force is determined on the basis of the theoretical method and calculation program using experimental boundary conditions.

2011-01-01

246

Honing the Dagger: The formation of a Standing Joint Special Operations Task Force Headquarters.  

Science.gov (United States)

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

2005-01-01

247

Force enhancement without changes in cross-bridge turnover kinetics: the effect of EMD 57033.  

UK PubMed Central (United Kingdom)

The thiadiazinon derivative EMD 57033 has been found previously in cardiac muscle to increase isometric force generation without a proportional increase in fiber ATPase, thus causing a reduction in...Full Text Available

1997-01-01

248

Effect of forced swimming stress on in-vivo fertilization capacity of rat and subsequent offspring quality  

UK PubMed Central (United Kingdom)

AIMS:This study aimed to determine the effect of 50 days of forced swimming stress on fertilization capacity of rat and subsequent offspring quality.SETTING...Full Text Available

2010-01-01

249

Defense Science Board Task Force on Technology Investment for the Defense Advanced Research Projects Agency (DARPA).  

Science.gov (United States)

As requested by the Under Secretary of Defense (Acquisition, Technology, and Logistics) and the Director DARPA, the Defense Science Board task force performed a one-time independent evaluation of the technology investment for the Defense Advanced Research...

2003-01-01

250

Continuum Polarizable Force Field within the Poisson-Boltzmann Framework  

UK PubMed Central (United Kingdom)

We have developed and tested a complete set of nonbonded parameters for a continuum polarizable force field. Our analysis shows that the new continuum polarizable model is consistent with B3LYP/cc-pVTZ...Full Text Available

2008-06-26

251

Army Corps as a Joint Task Force Headquarters.  

Science.gov (United States)

This study investigates the doctrinal guidance available to a corps headquarters if required to serve as ajoint task force headquarters and simultaneously be required to warfight the corps. The study contends that a corps being required to simultaneously ...

1997-01-01

252

Application of Information Superiority to a Joint Task Force Headquarters.  

Science.gov (United States)

Conceptual documents like Joint Vision 2010 (JV 2010), the Concept for Future Joint Operations (CFJO), and the Revolution in Military Affairs (RMA) postulate that advances in technology and information superiority will revolutionize the way military force...

2000-01-01

253

Actin Fusion Proteins Alter the Dynamics of Mechanically Induced Cytoskeleton Rearrangement  

UK PubMed Central (United Kingdom)

Mechanical forces can regulate various functions in living cells. The cytoskeleton is a crucial element for the transduction of forces in cell-internal signals and subsequent biological responses. Accordingly,...Full Text Available

254

32 CFR 185.4 - Policy.  

Science.gov (United States)

...undertake missions and tasks (on either a...Secretary of Defense to task the DoD Components...the Chairman of the Joint Chiefs of Staff any commitment of military forces assigned to the Unified... (9) Military forces employed in MSCA...approval from higher headquarters, local military...

2010-07-01

255

Interference phenomena at the elastic collision of atoms with formation of the Feshbach resonance in the presence of laser radiation field  

British Library Electronic Table of Contents (United Kingdom)

Resonant scattering of atoms with formation of the Feshbach resonance in the presence of a laser radiation coupling the levels of two bound atoms (a molecule) is considered. The laser field leads to a second resonance in scattering and broadening of resonances, which facilitates the possibility of experimental observation of asymmetry of the total scattering cross-section arising because of interference between resonant and potential scatterings. The effects associated with interference of the two channels of decay of a bound system of two atoms (a molecule) in the laser field are studied. An expression is obtained for the scattering length in collision of two cold atoms in the field of laser radiation.

2011-01-01

256

The Manning Requirements for the Navy's Forward ...  

Science.gov (United States)

... Task Force Commander's Handbook for Domestic ... and Radiological (CBR) Defense Requirements Supporting ... DC: Department of Navy, May 1996 ...

2011-05-13

257
258

Recognizing Signposts: Anticipating the Future Role of the ...  

Science.gov (United States)

... The second section describes the role and functions of a corps as a joint task force headquarters and uses Operation Uphold Democracy ...

2011-05-19

259

Operational Constraints on the Utility of Virtual Audio Cueing  

Science.gov (United States)

... conditions. the Air Force Research Laboratory's Aural Displays and The advent of virtual audio technology provides as many ...

1999-09-01

260

October 2003 Status of Forces Survey of DoD Civilians ...  

Science.gov (United States)

... h. Sick leave ..... 162 ... appraisals and approval of leave. ... Retirement System, FERS are employees ...

2004-03-01

261

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS - NASA Technical ...  

Science.gov (United States)

increase of pedel force; or amount of resistance to deflection. This result is in agreement wi"& the results of tests made on the ...

262

Meteorological Measurement Guide  

Science.gov (United States)

... 2-22 Page 31. The mercury barometer operates on the principle of air pressure forcing the mercury column up an evacuated tube. ...

1992-01-01

263

Managing the Army National Guard Full-Time Force  

Science.gov (United States)

... Evaluation Report (NCOER). The 360-Degree Assessment will be utilized by the leader/manager in conjunction with the counseling form and ...

2003-02-14

264

JW" rV-- - NASA  

Science.gov (United States)

roller bearing strength suffi- cient to support efficient, rolling friction movement, even in the presence of large, resisting forces. ...

266

Honing the Dagger: The formation of a Standing Joint Special ...  

Science.gov (United States)

... Admiral Olson mentions the requirement for a standing joint task force headquarters in USSOCOM in order to fulfill the command's charter as a ...

2005-05-26

268

Flight Investigation on a Fighter-Type Airplane of Factors ...  

Science.gov (United States)

... The maximum rate-of-deflection is not&d to decresse with increase of pedel force; or amount of resistance to deflection. ...

1947-08-01

269

Evaluation of the fluid force in main feed water control valve for APWRs  

International Nuclear Information System (INIS)

... 2432 v. 43(1) SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS

2006-01-01

270

Devolution through Transformation  

Science.gov (United States)

... Training System (JMATS) for joint C-130J training. However, the ... the C-130J's being procured by the Air Force. A logical ...

2011-05-14

271

Conversion of selected military forces to the use of metric measurement units  

Science.gov (United States)

Conversion of the United States military to the International System of measurement units is in the very early stages. Little formal planning has been done to articulate the management required to complete the conversion of operational Army and Air Force units. For those operational forces tasked to provide continuous combat readiness throughout metrication, management problems associated with the conversion are particularly difficult because of the nature of these assigned missions. This is the case for the 82nd Airborne Division ready brigade force (DRB) and the Military Airlift Command (MAC) strategic airlift system operating the C-141 and C-5A aircraft.

1976-06-01

272

An investigation of the decoupling effects in a magnetic forming beryllium coil assembly.  

Science.gov (United States)

Decoupling force exerted by magnetic forming Be coil assembly on metallic plate during forming

1968-01-01

273

Optimization of a parity of brake forces of automobiles in view of a bias of road  

International Nuclear Information System (INIS)

In clause it is shown a method optimization of brake of forces in view of a bias road it is established, that in mountain conditions of loss of coupling weight of automobiles than 2-3 times concerning flat conditions therma are more. The degree of use of coupling weight in result use of a regulator of brake forces very much increases also efficiency of brake systems such a kind of automobiles is provided with definition of optimum factor of coupling at which value of loss of coupling weight is provided minimal

274

Magnetic properties of materials  

Energy Technology Data Exchange (ETDEWEB)

A number of interactions between magnetic fields and matter is reviewed. The resulting forces range in magnitude from the very large, obtained in high-energy fields, to the weak ones caused by the magnetostriction of ferromagnets. The fundamentals of these interactions are highlighted, and the examples discussed are forces on dipoles, particle alignment, magnetostrictive forces, magnetic forming, magnetic stirring, levitation melting, and magnetic pulsing of tool steels. (orig.)

2000-08-15

275

Four-nucleon force using the method of unitary transformation  

Energy Technology Data Exchange (ETDEWEB)

We discuss in detail the derivation of the leading four-nucleon force in chiral effective field theory using the method of unitary transformation. The resulting four-nucleon force is given in both momentum and configuration space. It does not contain any unknown parameters and can be used in few- and many-nucleon studies. (orig.)

2007-11-15

276

Institute of Toxicology. 1994 annual report on research and development; Institut fuer Toxikologie. Ergebnisbericht ueber Forschung und Entwicklung 1994  

Energy Technology Data Exchange (ETDEWEB)

The R and D activities of the institute focused on two major projects, ``Molecular and cellular environmental toxicology``, and ``Biophysics of multi-cellular systems``. For assessment of health risks emanating from the uptake of heavy metal compounds, work performed under the first mentioned project studies the formation of allergy-inducing metabolic products from membrane lipids, and the effects of related cellular signaling processes. These studies are accompanied by an approach to quantify and classify the toxicity of environmental organometallic compounds. Another major task is research into the pathogenesis of lung disease induced by dusts, gases, and gas-dust mixtures and the liberation of inflammatory agents by immunological cell reactions (alveolar macrophages). Atomic force microscopy is the tool used to visualize the related dynamic changes in bronchial cells. Studies for detection of the localisation and structure of the Fe-Mo ...

1995-12-31

277

Heteroepitaxial growth of In-face InN on GaN (0001) by plasma-assisted molecular-beam epitaxy  

International Nuclear Information System (INIS)

The thermodynamic aspects of indium-face InN growth by radio frequency plasma-assisted molecular-beam epitaxy (rf-MBE) and the nucleation of InN on gallium-face GaN (0001) surface were investigated. The rates of InN decomposition and indium desorption from the surface were measured in situ using reflected high-energy electron diffraction and the rf-MBE 'growth window' of In-face InN (0001) was identified. It is shown that sustainable growth can be achieved only when the arrival rate of active nitrogen species on the surface is higher than the arrival rate of indium atoms. The maximum substrate temperature permitting InN growth as a function of the active nitrogen flux was determined. The growth mode of InN on Ga-face GaN (0001) surface was investigated by reflected high-energy electron diffraction and atomic force microscopy. It was found to be of the Volmer-Weber-type for substrate temperatures less than 350 deg. C and of ...

2005-06-01

278

{delta}-excitations and the three-nucleon force  

Energy Technology Data Exchange (ETDEWEB)

We study the three-nucleon force in chiral effective field theory with explicit {delta}-resonance degrees of freedom. We show that up to next-to-next-to-leading order, the only contribution to the isospin symmetric three-nucleon force involving the spin-3/2 degrees of freedom is given by the two-pion-exchange diagram with an intermediate delta, frequently called the Fujita-Miyazawa force. We also analyze the leading isospin-breaking corrections due to the delta. For that, we give the first quantitative analysis of the delta quartet mass splittings in chiral effective field theory including the leading electromagnetic corrections. The charge-symmetry breaking three-nucleon force due to an intermediate delta excitation is small, of the order of a few keV.

2008-06-15

279

Microgravity two-phase flow regime modeling  

Energy Technology Data Exchange (ETDEWEB)

A flow pattern or flow regime is the characteristics spatial distribution of the phases of fluid in a duct. Since heat transfer and pressure drop are dependent on the characteristic distribution of the phases, it is necessary to describe flow patterns in an appropriate manner so that a hydrodynamic or heat transfer theory applicable to that pattern can be chosen. The objective of the present analysis is to create a flow regime map based on physical modeling of vapor/liquid interaction phenomena in a microgravity environment. In the present work, four basic flow patterns are defined: dispersed flow, stratified flow, slug flow, and annular flow. Fluid properties, liquid and vapor flow rates, and pipe size were chosen as the principal parameters. It is assumed that a transition from one flow pattern to another will occur when there is a change in the dominant force which controls that flow pattern. The forces considered in this modeling are ...

1987-01-01

280

Estimation of elbow flexion force during isometric muscle contraction from mechanomyography and electromyography  

British Library Electronic Table of Contents (United Kingdom)

Mechanomyography (MMG) is the muscle surface oscillations that are generated by the dimensional change of the contracting muscle fibers. Because MMG reflects the number of recruited motor units and their firing rates, just as electromyography (EMG) is influenced by these two factors, it can be used to estimate the force exerted by skeletal muscles. The aim of this study was to demonstrate the feasibility of MMG for estimating the elbow flexion force at the wrist under an isometric contraction by using an artificial neural network in comparison with EMG. We performed experiments with five subjects, and the force at the wrist and the MMG from the contributing muscles were recorded. It was found that MMG could be utilized to accurately estimate the isometric elbow flexion force based on the v...

2010-01-01

281

Elastodynamics of vehicles and crash simulation  

Energy Technology Data Exchange (ETDEWEB)

Accidents of free-rolling cars against walls with friction are special cases of the general problem of the dynamic behavior (elastic or plastic) of car motion. Using particle modeling of the car body it is shown that large rotations, contact friction and plastic deformations can be computed. Because of the limitations of FEM it is necessary to model the car as a system of mass points connected by central force systems which are non-linear. The wall is formulated as a rigid body producing constraints for the contacting particles, while the contact force is given by the defined force system. Every contacting particle produces a plastic impact on the wall. The friction force is proportional to the contact force and lies in the direction of the sliding velocity on the wall. Time integration is carried out using a second order Gear method. ((orig.))

1994-09-30

282

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 in a slow time scale and a long spatial scale. Some fundamental ...

2007-04-21

283

The plasma generated and photons emitted in an oil-lubricated sliding contact  

International Nuclear Information System (INIS)

Intensive work has long been going on to find out the unknown origin that sets off curious tribo-physicochemical phenomena and that causes various kinds of problems in oil-lubricated sliding contacts in mechanical and processing systems. The strange tribochemical reaction is one of the such curious chemical phenomena observed in the degradation of perfluoropolyether (PFPE) lubricating oil film in a hard disk drive. Plasma (triboplasma) (Nakayama and Mirza 2006 Tribol. Trans. 49 17) would be one of the most probable origins of the problems if it were generated sufficiently intensely in oil-lubricated sliding contacts, as it is in such a highly energetic state. The generation of plasma was predicted in both dry and oil-lubricated sliding (Nakayama 1997 Japan. J. Tribol. 42 1077, Nakayama 2004 Surf. Coat. Technol. 188-189 599). However, plasma generation in industrially important oil-lubricated contacts has not yet been proven, though it has been found in dry sliding (Nakayama and ...

2007-02-21

284

Operation experience with the 3 MW TRIGA Mark-II research reactor of Bangladesh  

International Nuclear Information System (INIS)

The 3 MW TRIGA Mark-II research reactor of Bangladesh Atomic Energy Commission (BAEC) has been operating since September 14, 1986. The reactor is used for radioisotope production ("1"3"1I, "9"9"mTc, "4"6Sc), various R and D activities and manpower training. The reactor has been operated successfully since it's commissioning with the exception of a few reportable incidents. Of these, the decay tank leakage incident of 1997 is considered to be the most significant one. As a result of this incident, reactor operation at full power under forced-convection mode remained suspended for about 4 years. During that time, the reactor was operated at a power level of 250 kW so as to carry out experiments that require lower neutron flux. This was made possible by establishing a temporary by pass connection across the decay tank using local technology. The other incident was the contamination of the Dry Central Thimble (DCT) that took place in March 2002 ...

2004-09-15

285

Splice assembly tool and method of splicing  

Energy Technology Data Exchange (ETDEWEB)

A splice assembly tool for assembling component parts of an electrical conductor while producing a splice connection between electrical cables therewith, comprises a first structural member adaptable for supporting force applying means thereon, said force applying means enabling a rotary force applied manually thereto to be converted to a longitudinal force for subsequent application against a first component part of said electrical connection, a second structural member adaptable for engaging a second component part in a manner to assist said first structural member in assembling the component parts relative to one another and transmission means for conveying said longitudinal force between said first and said second structural members, said first and said second structural members being coupled to one another by said transmission means, wherein at least one of said component parts ...

1980-01-01

286

Spontaneously generated atomic entanglement in free space: reinforced by incoherent pumping  

CERN Document Server

We study spontaneously generated entanglement (SGE) between two identical multilevel atoms in free space via vacuum-induced radiative coupling. We show that the SGE in two-atom systems may initially increase with time but eventually vanishes in the time scale determined by the excited state lifetime and radiative coupling strength between the two atoms. We demonstrate that a steady-state SGE can be established by incoherently pumping the excited states of the two-atom system. We have shown that an appropriate rate of incoherent pump can help producing optimal SGE. The multilevel systems offer us more chanel to establish entanglement. The system under consideration could be realized in a tight trap or atoms/ions doped in a solid substrate.

2009-01-01

287

Scalable quantum computing with atomic ensembles  

International Nuclear Information System (INIS)

Atomic ensembles, comprising clouds of atoms addressed by laser fields, provide an attractive system for both the storage of quantum information and the coherent conversion of quantum information between atomic and optical degrees of freedom. We describe a scheme for full-scale quantum computing with atomic ensembles, in which qubits are encoded in symmetric collective excitations of many atoms. We consider the most important sources of error-imperfect exciton-photon coupling and photon losses-and demonstrate that the scheme is extremely robust against these processes: the required photon emission and collection efficiency threshold is #approx#>86%. Our scheme uses similar methods to those already demonstrated experimentally in the context of quantum repeater schemes and yet has information processing capabilities far beyond those proposals.

2010-09-01

288

Dynamics of spontaneous radiation of atoms scattered by a resonance standing light wave  

International Nuclear Information System (INIS)

The scattering of atoms by a resonance standing light wave is considered under conditions when the lower of two resonance levels is metastable, while the upper level rapidly decays due to mainly spontaneous radiative transitions to the nonresonance levels of an atom. The diffraction scattering regime is studied, when the Rabi frequency is sufficiently high and many diffraction maxima are formed due to scattering. The dynamics of spontaneous radiation of an atom is investigated. It is shown that scattering slows down substantially the radiative decay of the atom. The regions and characteristics of the power and exponential decay are determined. The adiabatic and nonadiabatic scattering regimes are studied. It is shown that the wave packets of atoms in the metastable and resonance excited states narrow down during scattering. A limiting (minimal) size of the wave packets is found, ...

2003-09-01

289

Atomic density functions: atomic physics calculations analyzed with methods from quantum chemistry  

CERN Document Server

This contribution reviews a selection of findings on atomic density functions and discusses ways for reading chemical information from them. First an expression for the density function for atoms in the multi-configuration Hartree--Fock scheme is established. The spherical harmonic content of the density function and ways to restore the spherical symmetry in a general open-shell case are treated. The evaluation of the density function is illustrated in a few examples. In the second part of the paper, atomic density functions are analyzed using quantum similarity measures. The comparison of atomic density functions is shown to be useful to obtain physical and chemical information. Finally, concepts from information theory are introduced and adopted for the comparison of density functions. In particular, based on the Kullback--Leibler form, a functional is constructed that reveals the periodicity in ...

2011-01-01

290

Hybrid apparatus for Bose-Einstein condensation and cavity quantum electrodynamics: Single atom detection in quantum degenerate gases  

International Nuclear Information System (INIS)

We present and characterize an experimental system in which we achieve the integration of an ultrahigh finesse optical cavity with a Bose-Einstein condensate (BEC). The conceptually novel design of the apparatus for the production of BECs features nested vacuum chambers and an in vacuo magnetic transport configuration. It grants large scale spatial access to the BEC for samples and probes via a modular and exchangeable ''science platform.'' We are able to produce 87Rb condensates of 5x106 atoms and to output couple continuous atom lasers. The cavity is mounted on the science platform on top of a vibration isolation system. The optical cavity works in the strong coupling regime of cavity quantum electrodynamics and serves as a quantum optical detector for single atoms. This system enables us to study atom optics on a single particle level and to further develop the field of quantum ...

2006-06-01

291

X rays in molecular biophysics  

Energy Technology Data Exchange (ETDEWEB)

An atom-by-atom understanding of life processes is emerging from a flurry of experiments fueled by synchrotron sources and DNA technology. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}.

1995-11-01

292

Spontaneous radiation of atomic oscillator, situated near ideally conducting cone surface  

International Nuclear Information System (INIS)

The line width of atom, situated near ideally conducting point or inside cone cavity in ideal conductor is analyzed. It is shown that the effect of point is decreased according to decreasing of its aperture angle

1998-01-01

293

Quinary metallic glass alloys  

Energy Technology Data Exchange (ETDEWEB)

At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 ...

1998-01-01

294

Nuclear Regulatory Commission issuances, June 1984. Volume 19, No. 6  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during the specified period from the Commission, the Atomic Safety and Licensing Appeal Boards, the Atomic Safety and Licensing Boards, the Administrative Law Judge, the Directors' Decisions, and the Denials of Petitions for Rulemaking.

1984-06-01

295

Nuclear Regulatory Commission issuances  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

1982-02-01

296

Nuclear Regulatory Commission Issuances  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during the specified period from the Commission (CLl), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), The Directors' Decisions (DD), and the Denials of Petitions For Rulemaking (DPRM).

1982-06-01

297

Laser Technology for Remote Treatment of Atomic Equipment  

International Science & Technology Center (ISTC)

Investigation of Interaction of Laser Radiation with Radioactive Deposits on the metal Surface and Creation of Experimental Stand for Development of Laser Technology for Remote Treatment of Materials Contaminated with Radioactive Substances at the Atomic Power Plants

298

Inhibited spontaneous emission by a Rydberg atom  

Science.gov (United States)

Spontaneous radiation by an atom in a Rydberg state is inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous radiation emission is observed to turn off abruptly at the cutoff frequency of the waveguidelike structure, and the natural lifetime is measured to increase by a factor of at least 20.

1985-11-11

299

In Silico Atomic Tracing by Substrate-Product Relationships in Escherichia coli Intermediary Metabolism  

UK PubMed Central (United Kingdom)

We present a software system that computationally reproduces biochemical radioisotope-tracer experiments. It consists of three main components: A mapping database of substrate-product atomic correspondents...Full Text Available

2003-11-01

300

Further assessment of the effects of occupational radiation exposure in the United Kingdom Atomic Energy Authority mortality study.  

UK PubMed Central (United Kingdom)

The United Kingdom Atomic Energy Authority mortality study was designed to investigate the relation between exposure to ionising radiation and mortality among the authority's employees. The present...Full Text Available

1987-03-01

301

The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)  

International Nuclear Information System (INIS)

Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but it is affected by ...

302

Theme and policy for international development of Japanese nuclear energy industries  

International Nuclear Information System (INIS)

Aug 2010 p. 31-35 Japan Kishioka, Kazuhiko Japan Atomic Industrial Forum,

2010-08-01

304

Regulation of red mud from the alumina industry in Australia  

International Nuclear Information System (INIS)

English 2005 p. 52-59 International Atomic Energy Agency (IAEA) Collier,

2002-09-23

305

Radioiodine benzodiazepines as brain imaging agents  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a radioiodinated benzodiazepine derivative. It comprises a lower alkyl group with 1-4 C-atoms and a radioactive iodine.

1992-03-17

306

Radioiodine benzodiazepines as brain imaging agents  

International Nuclear Information System (INIS)

This patent describes a radioiodinated benzodiazepine derivative. It comprises a lower alkyl group with 1-4 C-atoms and a radioactive iodine.

1990-06-25

307

Proceedings of 2007 national symposium on atomic energy  

International Nuclear Information System (INIS)

This publication is the collection of the paper presented at the title meeting. The 19 of the presented papers are indexed individually. (J.P.N.)

2007-05-30

308

Helium atom doping of molybdenum and its influence on the radiation hardenings  

International Nuclear Information System (INIS)

Experimental results on study of helium concentration influence on degree of molybdenum radiation hardening for various method of cyclotron doping differing in degree and damage character are presented. It is established that accumulation of helium atoms in molybdenum for simultaneous formation of radiation defects caused by low energetic primary-knocked atoms leads to higher degree of hardening than for high energetic ion irradiation. It is shown that with increase of helium atom concentration the degree of radiation hardening for the same level of damage increases. 4 refs.; 3 figs. (author).

1990-05-22

309

Fe clusters on Ni and Cu: size and shape dependence of the spin moment  

Energy Technology Data Exchange (ETDEWEB)

We present ab-initio calculations of the electronic structure of small Fe clusters (1-9 atoms) on Ni(001), Ni(111), Cu(001) and Cu(111) surfaces. Our focus is on the spin moments and their dependence on cluster size and shape. We derive a simple quantitative rule that relates the moment of each Fe atom linearly to its coordination number. Thus, for an arbitrary Fe cluster the spin moment of the cluster and of the individual Fe atoms can be readily found if the positions of the atoms are known. (orig.)

2006-01-01

310
311

Controlling the atom  

Energy Technology Data Exchange (ETDEWEB)

The authors trace the early history of nuclear power regulation in the US. Focusing on the Atomic Energy Commission, they describe the role of other groups that figured in the development of regulatory policies, including the Congressional Joint Committee on Atomic Energy, other federal agencies, state governments, the nuclear industry, and scientific organizations. They consider changes in public perceptions of and attitudes toward atomic energy and the dangers of radiation exposure. The basic purpose of the book is to provide the Nuclear Regulatory Commission and the general public with information on the historical antecedents and background of regulatory issues so that there will be continuity in policy decisions. The book concludes with an annotated bibliography of selected references. 19 figures.

1984-01-01

312

Concerning a Comprehensive Nuclear Test Ban  

Science.gov (United States)

... US Congress, Joint Committee on Atomic Energy, Development, Use, and Control ofNuclear Energy for the Common Defense and Security and for ...

2011-05-14

313

Astronautics and Aeronautics, 1974 - NASA History Office  

Science.gov (United States)

The congressional Joint Committee on Atomic Energy issued the panel report Transportation of Radioactive Material by Passenger Aircraft. ...

314

Secure direct communication using the 'polarization' entangled atomic ensembles  

Energy Technology Data Exchange (ETDEWEB)

We propose a scheme with potential experimental realization to generate 'polarization' entanglement between two atomic ensembles and show one of the applications - a novel secure communication allowing asymptotically key distribution and quasisecure direct communication. The scheme involves laser manipulation of atomic ensembles, adjustable quarter- and half-wave plates, beam splitters, polarizing beam splitters and single-photon detectors, and well fits the status of the current experimental technology.

2004-02-14

315

Rubidium 5"2P fine-structure transitions induced by collisions with potassium and caesium atoms  

International Nuclear Information System (INIS)

A diode-laser fluorescence experiment was performed in order to study fine-structure transitions between 5"2P states of rubidium atoms colliding with ground-state potassium or caesium atoms. The Rb(5"2P_3_/_2) state was optically excited and the intensity ratio of sensitized to direct fluorescence was measured. (author).

316

Photoexcitation and optical pumping in a barium atomic beam  

International Nuclear Information System (INIS)

An apparatus allowing the photoexcitation of barium atomic beam over its whole surface is described. This photoexcitation is achieved by another barium spectrum emitted up steam of the beam by a cathodic out-flow produced at the exit oven. The fluorescence spectrum is studied in detail as well as the influence of different parameters, such as oven temperature, current intensity of the outflow, and excitation depth. A calculation shows how to determine Einstein coefficient, oscillator strengths and atomic lifetimes from our experimental measurements.

317

Magnetic behavior in the U/sub 1-x/Th/sub x/Cu_2Si_2 system  

International Nuclear Information System (INIS)

The compound UC_2Si_2 has been found to be ferromagnetic at low temperatures with a Curie temperature of 101"0K. The magnetization follows a Curie-Weiss law in the paramagnetic region with an effective magneton number of 2.12 Bohr magnetons per uranium atom. Partial substitution of Th atoms for the U atoms results in an expansion of the lattice, a rapid drop in the Curie temperature, and a sizable increase in the coercive field.

1986-06-23

318

Effective atomic numbers and electron densities of some biologically important compounds containing H, C, N and O in the energy range 145-1330 keV  

International Nuclear Information System (INIS)

A semi-empirical relation which can be used to determine the total attenuation cross sections of samples containing H, C, N and O in the energy range 145-1332 keV has been derived based on the total attenuation cross sections of several sugars, amino acids and fatty acids. The cross sections have been measured by performing transmission experiments in a narrow beam good geometry set-up by employing a high-resolution hyperpure germanium detector at seven energies of biological importance such as 145.4 keV, 279.2 keV, 514 keV, 661.6 keV, 1115.5 keV, 1173.2 keV and 1332.1 keV. The semi-empirical relation can reproduce the experimental values within 1-2%. The total attenuation cross sections of five elements carbon, aluminium, titanium, copper and zirconium measured in the same experimental set-up at the energies mentioned above have been used in a new matrix method to evaluate the effective atomic numbers and the effective electron densities of samples such as ...

2006-09-28

319

Atom interferometry with lithium atoms: theoretical analysis and design of an interferometer, applications; Interferometrie atomique avec l'atome de lithium: analyse theorique et construction d'un interferometre, applications  

Energy Technology Data Exchange (ETDEWEB)

This thesis is devoted to studies which prepared the construction of an atom Mach-Zehnder interferometer. In such an interferometer, the propagating waves are spatially separated, and the internal state of the atom is not modified. The beam-splitters are diffraction gratings, consisting of standing optical waves near-resonant with an atomic transition. We use the Bloch functions to define the atom wave inside the standing wave grating and thus explain the diffraction process in different cases. We developed a nearly all-analytical model for the propagation of an atom wave inside a Mach-Zehnder interferometer. The contrast of the signal is studied for many cases: phase or amplitude gratings, effects of extra paths, effects of the main mismatches, monochromatic or lightly polychromatic sources. Finally, we discuss three interferometric measurements we think very interesting. The ...

1999-12-01

320

A Theory of Laser Induced Nuclear Reaction in Single Atoms  

International Nuclear Information System (INIS)

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

2010-02-02

321

Transient analysis of blowdown thrust force under PWR LOCA conditions  

Energy Technology Data Exchange (ETDEWEB)

The analytical results of blowdown characteristics and its thrust force were compared with the experiment, which were performed as pipe whip tests under the PWR LOCA conditions on the hypothetical accident of guillotine break of pipes. The blowdown thrust force was obtained by the integral momentum equation about single-phase flow, homogeneous and separated two-phase flow, assuming critical pressure at the exit if critical flow condition was satisfied. The following results are obtained: (1) The node-junction method is useful for the analysis of water hammer phenomena and of the blowdown thrust force. (2) The Henry-Fauske model for subcooled critical flow is effective for the analysis of the maximum thrust force under the PWR LOCA conditions. The jet thrust parameter of analysis and experiment is 1.08. (3) The thrust parameter of saturated blowdown has the same one with the value under pressurized ...

1982-09-01

322

Transient analysis of blowdown thrust force under PWR LOCA  

Energy Technology Data Exchange (ETDEWEB)

The analytical results of blowdown characteristics and thrust forces were compared with the experiments, which were performed as pipe whip and jet discharge tests under the PWR LOCA conditions. The blowdown thrust forces were obtained by Navier-Stokes momentum equation for a single-phase, homogeneous and separated two-phase flow, assuming critical pressure at the exit if a critical flow condition was satisfied. The following results are obtained: (1) The node-junction method is useful for both the analyses of the blowdown thrust force and of the water hammer phenomena. (2) The Henry-Fauske model for subcooled critical flow is effective for the analysis of the maximum thrust force under the PWR LOCA conditions. The jet thrust parameter of the analysis and experiment is equal to 1.08. (3) The thrust parameter of saturated blowdown has the same one with the value under pressurized condition when the ...

1983-04-01

323

Robust computationally efficient control of cooperative closed-chain manipulators with uncertain dynamics  

British Library Electronic Table of Contents (United Kingdom)

This article presents a decentralized control scheme for the complex problem of simultaneous position and internal force control in cooperative multiple manipulator systems. The proposed controller is composed of a sliding mode control term and a force robustifying term to simultaneously control the payloads position/orientation as well as the internal forces induced in the system. This is accomplished independently of the manipulators dynamics. Unlike most controllers that do not require prior knowledge of the manipulators dynamics, the suggested controller does not use fuzzy logic inferencing and is computationally inexpensive. Using a Lyapunov stability approach, the controller is proven to be robust in the face of varying systems dynamics. The payloads position/orientation and the inte...

2007-01-01

324

Non-gravitational perturbations and satellite geodesy  

Energy Technology Data Exchange (ETDEWEB)

This book presents the basic ideas of the physics of non-gravitational perturbations and the mathematics required to compute their orbital effects. It conveys the relevance of the different problems that must be solved to achieve a given level of accuracy in orbit determination and in recovery of geophysically significant parameters. Selected Contents are: Orders of Magnitude of the Perturbing Forces, Tides and Apparent Forces, Tools from Celestial Mechanics, Solar Radiation Pressure-Direct Effects: Satellite-Solar Radiation Interaction, Long-Term Effects on Semi-Major Axis, Radiation Pressure-Indirect Effects: Earth-Reflected Radiation Pressure, Anisotropic Thermal Emission, Drag: Orbital Perturbations by a Drag-Like Force, and Charged Particle Drag.

1987-01-01

325

HANARO cooling features: design and experience  

International Nuclear Information System (INIS)

In order to achieve the safe core cooling during normal operation and upset conditions, HANARO adopted an upward forced convection cooling system with dual containment arrangements instead of the forced downward flow system popularly used in the majority of forced convection cooling research reactors. This kind of upward flow system was selected by comparing the relative merits of upward and downward flow systems from various points of view such as safety, performance, maintenance. However, several operational matters which were not regarded as serious at design come out during operation. In this paper are presented the design and operational experiences on the unique cooling features of HANARO. (author)

1999-08-01

326

Cutting force analysis as a tool for evaluating the surface quality of machined parts  

International Nuclear Information System (INIS)

Surface quality is one of the most important criteria for establishing the optimum cutting parameters needed to perform a machining process. Usually, the evaluation of the degree of the surface finishing requires to apply metrological techniques which involve times out in the production. As a consequence of this, a loss in both the economy of the process and the fiability of the tests reproducibility can be produced. In this work a relation between cutting force and surface roughness has been studied for the turning process of an Al-Cu alloy. From this relation, the surface quality of the machined samples can be evaluated by using the cutting forces values acquired during the cutting process. (Author) 8 refs.

327

Electron scattering from atoms in the presence of a laser field. II  

Science.gov (United States)

In the first paper of this series a formal theory of atomic scattering of electrons in the presence of an intense electromagnetic field was given. Cross sections, near the forward direction, between atomic states (modified by the laser) were obtained. However, it was assumed that the atom could not emit spontaneous radiation. In this paper the effect of spontaneous radiation is included, and it is shown that in most cases the measured cross section will be a weighted average of the two different cross sections starting from the two different initial states which are those atomic states resonantly linked by the laser. The Born approximation for the scattering is obtained, and it is shown that for the simplest description of the spontaneous radiation field the effect of the laser on the cross sections is simply to multiply them by a factor which depends upon the laser detuning. (AIP)

1976-10-01

328

Converting hcp Mg-Al-Zn alloy into bcc Mg-Li-Al-Zn alloy by electrolytic deposition and diffusion of reduced lithium atoms in a molten salt electrolyte LiCl-KCl  

Energy Technology Data Exchange (ETDEWEB)

A body-centered cubic (bcc) Mg-12Li-9Al-1Zn (wt.%) alloy was fabricated in air by electrolysis from LiCl-KCl molten salt at 500 deg. C. Electrolytic deposition of Li atoms on cathode (Mg-Al-Zn alloy) and diffusion of the Li atoms formed the bcc Mg-Li-Al-Zn alloy with 12 wt.% Li and only 0.264 wt.% K. Low K concentration in the bcc Mg alloy strip after the electrolysis process resulted from 47% atomic size misfit between K and Mg atoms and low solubility of K in Mg matrix.

2007-04-15

329

Converting hcp Mg-Al-Zn alloy into bcc Mg-Li-Al-Zn alloy by electrolytic deposition and diffusion of reduced lithium atoms in a molten salt electrolyte LiCl-KCl  

British Library Electronic Table of Contents (United Kingdom)

A body-centered cubic (bcc) Mg-12Li-9Al-1Zn (wt.%) alloy was fabricated in air by electrolysis from LiCl-KCl molten salt at 500degreeC. Electrolytic deposition of Li atoms on cathode (Mg-Al-Zn alloy) and diffusion of the Li atoms formed the bcc Mg-Li-Al-Zn alloy with 12wt.% Li and only 0.264wt.% K. Low K concentration in the bcc Mg alloy strip after the electrolysis process resulted from 47% atomic size misfit between K and Mg atoms and low solubility of K in Mg matrix.

2007-01-01

330

contents - NASA History Office  

Science.gov (United States)

David N. Spires and Rick W. Sturdevant, "From Advent to Milstar: The United States Air Force and the Challenges of Military Satellite Communications. Chapter 8 ...

331

X-15 Research Results: Chapter 9  

Science.gov (United States)

... hypersonic aerodynamic force, or the space-equivalent region. Some of these experiments change the X-15 from a research airplane to a kind of space probe, ...

332

Wind and Wave Forcing of Longshore Currents Across a ...  

Science.gov (United States)

... These assumptions are quantitatively investigated by calculating tie icldti\\e inportance of ... A modified lon-shore current model is used to study the ...

1988-06-01

333

WYVERN S. MK.4 VW. 884 (PYTHON 3) LATERAL AND ...  

Science.gov (United States)

... Occasionally during the climb tests there appeared to be very slight lightening of the pedEl forces just before full travel was reached. /4.2.... - ...

1953-08-18

334

View Transcript (111 Kb PDF) - NASA  

Science.gov (United States)

Sep 8, 2005 ... one of the headquarters buildings here at Stennis, took off .... Also, they have a joint task force, that the ...

335

United States Air Force Summer Research Program 1991. ...  

Science.gov (United States)

... 14. Pfeifer, HJ, (1986), "Correlation and Spectral Density Measurements by LDA," Proceedings of the 5th International Congress on Applications of ...

1992-01-09

336

United States Air Force Computer-Aided Acquisition and ...  

Science.gov (United States)

... of Packaging Requirements. MIL-STD-2073-1 DoD Packaging Data Forms Instruction for Preparation and Use. I DATA ...

1988-10-01

337

US Forces in Iraq  

Science.gov (United States)

... Army 2nd Brigade, 82nd Airborne Division Fort Bragg, NC January, 2007 ... 1st Brigade, 82nd Airborne Division Fort Bragg, NC early-2007 ...

2007-01-11

338

Training the Force: Developing Financially Fit Service ...  

Science.gov (United States)

... 4. To measure my personal wealth by net worth, not income 5. To engage in sound budget, credit and tax management practices 6. ...

2011-05-13

339

The restructured Milstar program  

Science.gov (United States)

This paper discusses the restructure of the Milstar communication satellite program. The resulting system is substantially streamlined, and will provide better utilization by tactical forces without compromising strategic nuclear communications requirements.

1992-03-01

341

The Use of Restricted Air Force Technologies in Joint Federal ...  

Science.gov (United States)

... Concerning Persons and Organizations not Affiliated with the Department of Defense," January 7, 1980 (f) DoD 5240.1-R, "Procedures Governing ...

2011-05-14

342

The Numerical Weather Prediction System at the Italian Air ...  

Science.gov (United States)

... Title : The Numerical Weather Prediction System at the Italian Air Force Weather Service: Impact of Non-Conventional Observations and Increased ...

2004-06-01

343

The Combat Logistics Force: Sustaining an Army Airborne ...  

Science.gov (United States)

... the political charisma to compete with support of heavy divisions until recently. ... 82nd Airborne Division, the 101st Air Assault Division, the ...

1993-06-05

344

Temperature stabilization, ocean heat uptake and radiative forcing overshoot profiles  

British Library Electronic Table of Contents (United Kingdom)

Political leaders in numerous nations argue for an upper limit of the global average surface temperature of 2 K above the pre-industrial level, in order to attempt to avoid the most serious impacts of climate change. This paper analyzes what this limit implies in terms of radiative forcing, emissions pathways and abatement costs, for a range of assumptions on rate of ocean heat uptake and climate sensitivity. The primary aim is to analyze the importance of ocean heat uptake for radiative forcing pathways that temporarily overshoot the long-run stabilization forcing, yet keep the temperature increase at or below the 2 K limit. In order to generate such pathways, an integrated climate-economy model, MiMiC, is used, in which the emissions pathways generated represent the least-cost solution o...

2011-01-01

345

Technical evaluation report for the demonstration of radio frequency soil decontamination at Site S-1  

Energy Technology Data Exchange (ETDEWEB)

The Air Force`s Armstrong Laboratory at Tyndall Air Force Base, Florida, has supported the research and development of Radio Frequency Soil Decontamination. Radio frequency soil decontamination is essentially a heat-assisted soil vapor extraction process. Site S-1 at Kelly Air Force Base, San Antonio, Texas, was selected for the demonstration of two patented techniques. The site is a former sump that collected spills and surface run-off from a waste petroleum, oils, and lubricants and solvent storage and transfer area. In 1993, a technique developed by the IIT Research Institute using an array of electrodes placed in the soil was demonstrated. In 1994, a technique developed by KAI Technologies, Inc. using a single applicator placed in a vertical borehole was demonstrated. Approximately 120 tons of soil were heated during each demonstration to a temperature of about 150 degrees Celsius.

1995-04-01

346

Task Force Butler: A Case Study in the Employment of an Ad ...  

Science.gov (United States)

... east. The two most important offensives, Operation EPSOM (25 June to 1 July 1944) and Operation GOODWOOD (18 to ...

2007-12-14

347

THE INVESTIGATION OF THE NATURE OF THE FORCES OF ...  

Science.gov (United States)

... pr h-±rmt of im- mersion isotherme of VIMCH and VYHH which are film formers of v,,yl chloride-acetate co-r~polyrers. VMCH has excelleut r.Lr-dry ...

1956-06-30

348

Reliability of indices of neuromuscular leg performance in end-stage renal failure.  

Science.gov (United States)

The purpose of this study was to examine the day-to-day reproducibility and single measurement reliability of peak force, time to half peak force and rate of force development indices of knee extension neuromuscular performance in patients with end-stage renal failure. Eleven self-selected patients (6 men, 5 women) receiving maintenance dialysis (dialysis history 67 +/- 42.8 month) completed 3 inter-day assessment sessions. Each comprised a standardized warm-up and 3 intermittent static maximal voluntary actions of the knee extensors of the preferred limb (45 degrees knee flexion angle [0 degrees = full knee extension]) using a specially-constructed dynamometer. Repeated measures ANOVA of coefficient of variation scores revealed significant differences between indices in their reproducibility across day-to-day trials. Post-hoc comparisons of group mean scores suggested that peak force (6.6 +/- 3.0%) ...

2002-11-01

349

Published ... - Wind Tunnels | NASA Ames Research Center - NASA  

Science.gov (United States)

Sep 5, 2008 ... Russia. The six-component balance for blunt models aerodynamic force measurement in shock tunnel. Lu Zhiquo, Liu Hongshan, Zhang Yan ...

350

Optimization for Vibration Isolation.  

Science.gov (United States)

An almost linear optimization problem of importance in vibration isolation has been identified and algorithms were developed to minimize the forced vibrational response of structural systems. The constraints can be either displacements of accelerations. T...

1983-01-01

351

Numerical and semi-analytic core mass distributions in supersonic isothermal turbulence  

CERN Document Server

We investigate the influence of the turbulence forcing on the mass distributions of gravitationally unstable cores by postprocessing data from simulations of non-selfgravitating isothermal supersonic turbulence with varying resolution. In one set of simulations solenoidal forcing is applied, while the second set uses purely compressive forcing to excite turbulent motions. From the resulting density field, we compute the mass distribution of gravitationally unstable cores by means of a clump-finding algorithm. Using the time-averaged probability density functions of the mass density, semi-analytic mass distributions are calculated from analytical theories. We apply stability criteria that are based on the Bonnor-Ebert mass resulting from the thermal pressure and from the sum of thermal and turbulent pressure. Although there are uncertainties in the application of the clump-finding algorithm, we find systematic differences in ...

2010-01-01

352

Nonlinear dynamic analysis of high energy line pipe whip  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a nonlinear dynamic analysis of TVA high energy line pipe whip tests using the ABAQUS-EPGEN code. The analysis considers the effects of large deformation and strain rate on resisting moment and energy absorption capability. The numerical results of impact forces, impact velocities, pipe strains, and reaction forces at pipe supports are compared to the TVA test data. The calculated pipe whip impact time and forces are also compared with those predicted using current industry practice. The calculated pipe support reaction forces are found to be in good agreement with the TVA test data except for some peak values at the very beginning of the pipe break. These peaks are believed to be due to stress wave propagation which cannot be addressed by the ABAQUS code. Both elbow crushing and strain rate have been approximately simulated. The effects are found to be important for pipe whip ...

1984-02-01

353

New implementation of a shear-force microscope suitable to study topographical features over wide areas  

International Nuclear Information System (INIS)

A new implementation of a shear-force microscope is described that uses a shear-force detection system to perform topographical imaging of large areas (#approx#1x1 mm"2). This implementation finds very interesting application in the study of archeological or artistic samples. Three dc motors are used to move a sample during a scan, allowing the probe tip to follow the surface and to face height differences of several tens of micrometers. This large-area topographical imaging mode exploits new subroutines that were added to the existing homemade software; these subroutines were created in Microsoft VISUAL BASIC 6.0 programming language. With this new feature our shear-force microscope can be used to study topographical details over large areas of archaeological samples in a nondestructive way. We show results detecting worn reliefs over a coin.

2006-09-01

354

New Perspectives on Contingency Corps Force Structure  

Science.gov (United States)

... heavy divisions in the Contingency Corps should ... During Operation Desert Shield the 82nd Airborne Division initially deployed a reinforced attack ...

1992-04-15

355

New Image - ONLY - Scan to PDF - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Variations,of-the ,rudder pedel force with.indicated airspeed are shown in figure 16 for the six vertical-tail configurations. -tested. ...

356

Multinational C2 Experiments Supported by C2 Systems and ...  

Science.gov (United States)

... WHS- Washington Headquarters Service ... but also with respect to other Joint, National and ... unit of action (UA) combat team or task force is organized ...

2003-06-01

357

Monthly Newsletter October 2003 NASA OH ... - OH Home - NASA  

Science.gov (United States)

with health information management technology Agency-wide. In parallel to the task force appointment, a request for information ...

358

Managing Messaging and Data Processing Centers  

Science.gov (United States)

... established in allied communications publications (ACP); DISA circulars (DISAC), Joint Army-Navy-Air Force publications (JANAP), and MAJ- COM ...

1998-03-01

359

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

360

Lightning Detection for an Air Force Automated Observation ...  

Science.gov (United States)

... of six lightning warning systems was carried out in 1979 as a result of lightning-induced premature explosions in open-pit mining operations. ...

1988-06-08

361

Land Information System LIS Reference Manual  

Science.gov (United States)

May 4, 2010 ... This routine interpolates atmospheric adtt seconds period forcing ... for one adtt interval. Interpolation is performed based on the value ...

362

Keeping the Corps: The Continued Relevance of the Corps ...  

Science.gov (United States)

... XVIII Airborne Corps forces grew from one brigade of the 82nd Airborne Division to a multi-national organization of five full divisions (Eastern Area ...

2004-05-26

363

Influence: Maximizing Effects to Create Long-Term Stability  

Science.gov (United States)

... WHS- Washington Headquarters Service. ... The dynamic Joint Special Operations Task Force -- Philippines (JSOTF-P) has evolved and ...

2010-05-03

364

Increasing the Ground Tactical Mobility Of US Airborne Forces ...  

Science.gov (United States)

... public and civilian leadership considers the Insertion of the 82nd ... C+7, an airborne/light division by C+ 12, two heavy divisions by C+30, ...

1992-12-17

365

I. Introduction  

Science.gov (United States)

... Experts ( Appendix 5 ), and the NMFS-Sea Grant Joint Graduate Fellowship Program ( Appendix 6) . The Task Force consisted of one representative from NMFS Headquarters and 1-2 rep...

366

How Can Political Campaign Strategy be Adopted to Support ...  

Science.gov (United States)

... WHS- Washington Headquarters Service ... present a framework based on political campaigns theory for both the Joint Task Force Commander down ...

2010-10-27

367

History of the Army Ground Forces. Study Number 13. ...  

Science.gov (United States)

... reconnaissance. Presently the signal ompWa captain rushed up, salutec snappily, anI reported. When the general inquired how. ...

1948-06-30

368

Handbook on Ground Forces Attrition in Modern Warfare  

Science.gov (United States)

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

1986-09-01

369

Galaxy rotation curves: the effect of Formula Not Shown force  

British Library Electronic Table of Contents (United Kingdom)

Using the Galaxy as an example, we study the effect of Formula Not Shown force on the rotational curves of gas and plasma in galaxies. Acceptable model for the galactic magnetic field and plausible physical parameters are used to fit the flat rotational curve for gas and plasma based on the observed baryonic (visible) matter distribution and Formula Not Shown force term in the static MHD equation of motion. We also study the effects of varied strength of the magnetic field, its pitch angle and length scale on the rotational curves. We show that Formula Not Shown force does not play an important role on the plasma dynamics in the intermediate range of distances 6?12?kpc from the centre, whilst the effect is sizable for larger r (r?15?kpc), where it is the most crucial.

2011-01-01

370

Foundational Principles for Organizing a Joint Force Staff  

Science.gov (United States)

... Chiefs of Staff, Joint Operation Planning and Execution System (JOPES) Volume I, Planning and Procedures, CJCSM 3122.01A (Washington, DC ...

2009-03-18

371

Executive Summary-Department of Defense - NASA History Office  

Science.gov (United States)

Sep 5, 1996 ... In Haiti, the military deployed a space support team to advise the task force commander on the effective use of space assets, such as the Milstar ...

372

Environmental Impact Analysis Process. Final Environmental ...  

Science.gov (United States)

... Abstract : The United States Air Force (USAF) currently operates the Milstar satellite system to provide Military Satellite Communication Systems ...

2001-02-15

373

Eddy Current Flows Around Cracks in Thin Plates for ...  

Science.gov (United States)

... A few applications, such as magnetic forming and levitation, have exploited the dynamic force pro- ducing capability of eddy currents. ...

1981-03-01

374

Development of a UGV-Mounted Automated Refueling System ...  

Science.gov (United States)

... and Unmanned Undersea Vehicle (UUV) communities as well. ... utilizes the Multi-Robot Operator Control ... Extending Mobile Security Robots to Force ...

2011-05-13

375

DefenseLINK News: DoD Selected Acquisition Report  

Science.gov (United States)

... Change $ -37.0. June 1996 (70 programs*) $ 707,771.1. *Excludes classified costs for the Air Force's MILSTAR program. As of ...

376

DefenseLINK News: Combined US- Australian Exercise ...  

Science.gov (United States)

... the USCINCPAC staff and the staff of the commander, US Seventh Fleet, as a designated Pacific Command Joint Task Force Headquarters, in crisis ...

377

Defense.gov News Article: Exercise Preps 82nd Airborne ...  

Science.gov (United States)

... Exercise Preps 82nd Airborne Division Staff for Afghanistan Deployment. By Donna Miles American Forces Press Service. WASHINGTON, Nov. ...

378

Casimir repulsion beyond the dipole regime  

CERN Document Server

We extend a previous result [Phys. Rev. Lett. 105, 090403 (2010)] on Casimir repulsion between a plate with a hole and a cylinder centered above it to geometries in which the central object can no longer be treated as a point dipole. We show through numerical calculations that as the distance between the plate and central object decreases, there is an intermediate regime in which the repulsive force increases dramatically. Beyond this, the force rapidly switches over to attraction as the separation decreases further to zero, in line with the proximity force approximation. We demonstrate that this effect can be understood as a competition between an increased repulsion due to a larger polarizability of the central object interacting with increased fringing fields near the edge of the plate, and attractive forces due primarily to the nonzero thickness of the plate. In comparison with our previous work, we ...

2011-01-01

379

COAST and MRO to Join Forces  

Science.gov (United States)

Cambridge scientists in the late 1980's. This same team, then headed by Professor John Baldwin, built the world's first separated-element optical/infrared aperture synthesis...

2011-09-15

380

CERN scientists confront data deluge  

CERN Multimedia

The next generation of particle accelerator is currently being designed at CERN. An understanding of the market forces in the computer industry will play a crucial role in the success of the project.

1998-01-01

381

Army Transformation to Expeditionary Formations  

Science.gov (United States)

... gap" between the arrival ofquick response forces, such as the 82nd Airborne Division and the ... nd Airborne is just exactly that, light airborne infantry. ...

2011-05-14

382

Aerodynamic Static Differential Pressure  

Science.gov (United States)

aerodynamic force and moment values. Only the solid and the 25 percent porous dishes were tested for the static pressure values used primarily to determine ...

383

ACTIVE AEROELASTIC WING ROLLOUT ACCENTS 'BACK TO THE - NASA  

Science.gov (United States)

The traditional wing control surfacestrailing edge ailerons and the outboard leading edge flapsare used to provide the aerodynamic force needed to twist ...

384

50 (Fifty) Years of Research on Man in Flight  

Science.gov (United States)

... i3a. ... This pioneering research established the new Air Force standard for future ... Echols ,.stablished new standards for high- altitude long-range flight ...

1985-06-01

385

1.1 Constructive Engineering of Simulations - NASA Technical ...  

Science.gov (United States)

joint task force (JTF), division (OIV) and regimental combat team (RCT) with ..... Headquarters, Department of the Army. (HQOA), (2010). Field Manual 2-0 ...

386

First-principles study of the micro-arrangement of hydrogen atoms and electronic properties of LaNi_5H_x (x: 0.5-7)  

International Nuclear Information System (INIS)

The micro-arrangement of hydrogen atoms and the electronic properties of hydrides LaNi_5H_x (0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0) have been systematically investigated by means of the density functional theory using the full-potential linearized augmented plane wave (FLAPW) method with the generalized gradient approximation (GGA). The calculated results indicate that H atoms prefer to occupy the 12n site in the #alpha# solid solution phase. For the #beta# phase, once the first H atom locates in the basal plane (12n site), and because it is difficult for the second H atom to still locate in the 12n site, the second H atom would prefer to occupy the middle plane site (6m site). When the number of H atoms increases from 3 to 5, they would occupy the other 12n and 6m sites by turns. Furthermore, our optimized data indicate that the structures P3 and P63mc are the ...

2008-07-01

387

Distribution of quantum information between an atom and two photons  

Energy Technology Data Exchange (ETDEWEB)

The construction of networks consisting of optically interconnected processing units is a promising way to scale up quantum information processing systems. To store quantum information, single trapped atoms are among the most proven candidates. By placing them in high finesse optical resonators, a bidirectional information exchange between the atoms and photons becomes possible with, in principle, unit efficiency. Such an interface between stationary and ying qubits constitutes a possible node of a future quantum network. The results presented in this thesis demonstrate the prospects of a quantum interface consisting of a single atom trapped within the mode of a high-finesse optical cavity. In a two-step process, we distribute entanglement between the stored atom and two subsequently emitted single photons. The long atom trapping times achieved in the system together with the high ...

2008-11-03

388

Atoms as Qed bound atoms  

International Nuclear Information System (INIS)

The relevance of Quantum Electrodynamics (Qed) in contemporary atomic structure theory is reviewed. Recent experimental advances allow both the production of heavy ions of high charge as well as the measurement of atomic properties with a precision never achieved before. The description of heavy atoms with few electrons via the successive incorporation of one, two, etcetera photons in a rigorous manner and within the bound state Furry representation of Qed is technically feasible. For many-electron atoms the many-body (correlation) effects are very important and it is practically impossible to evaluate all the relevant Feynman diagrams to the required accuracy. Thus, it is necessary to develop a theoretical scheme in which the radiative and nonradiative effects are taken into account in an effective way making emphasis in electronic correlation. Preserving gauge invariance, and avoiding both continuum ...

389

Atomic beam spectrometer using a LiF analyzer crystal  

International Nuclear Information System (INIS)

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

1978-01-01

390

A study of public acceptance of construction of atomic power plant  

International Nuclear Information System (INIS)

In June 2010, Basic Energy Plan was approved in a Cabinet meeting. It says that Japan aims to construct more than 14 atomic power plants by 2030. Today, there are 12 plans of construction of atomic power plant, but it is hard to say that their plans easily come off. That's because public acceptance of atomic power plant is low in Japan, for example local residents wage opposition campaigns. This study conducts a survey in the form of a questionnaire and analyzes it by Analytical Hierarchical Process (AHP). Analytic Hierarchy Process is a structured technique for dealing with complex decisions. A questionnaire using AHP is very easy to answer and analyze. This survey was conducted in 2 areas. First area is Hohoku-cho, Yamaguchi Pref. that had a plan of construction of atomic power plant and the plan was demolished by opposition campaigns. Second area is Kaminoseki-cho, Yamaguchi Pref. that has a plan of ...

2011-01-01

391

Integrated Safeguards proposal for Finland. Final report on Task FIN C 1264 of the Finnish Support Programme to IAEA Safeguards  

Energy Technology Data Exchange (ETDEWEB)

The IAEA has requested several member states to present their proposal of the application of the Integrated Safeguards (IS) system in their nuclear facilities. This report contains a IS proposal for Finland prepared under the Task FIN C 1264 of The Finnish Support Programme to IAEA Safeguards. The comprehensive safeguards system of the International Atomic Energy Agency (IAEA) has been one of the main tools in the fight against nuclear proliferation since the entry-into-force of the Nuclear Non-proliferation Treaty three decades ago. In the 1990s some of the inherent weaknesses of this so-called traditional safeguards system were revealed first in Iraq and then in North Korea. Therefore, the member states of the LAEA decided to give the Agency additional legal authority in order to make its control system more effective as well as more efficient than before. This was accomplished by the approval of the so-called Model Additional Protocol ...

2000-08-01

392

Wind turbine  

Energy Technology Data Exchange (ETDEWEB)

A wind turbine is provided which consists of novel vanes horizontally oriented about a rotating hub connected to a vertical shaft. The vanes are free to pivot about two horizontal hinges such that two vanes connected to each other open when wind force is applied, and close when there is little or no wind force such that there is a minimal amount of resistance to the travel of the vanes when the vanes are against the wind.

1983-03-22

393

Time Average Aerodynmic Forces and Moments on a National Model of a Semi-Submersible Offshore Rig. Part 1. Measurements. Part 2. Analysis of Results for the Basic Model.  

Science.gov (United States)

Wind-tunnel measurements were taken of the time-average aerodynamic forces and moments on a notional model of a semi-submersible offshore drilling rig at two heights and at various attitudes to the wind. Attempts were made to analyze the separate effects ...

1982-01-01

394

Third World Arms Proliferation and Forced Entry Operations: Circumstances Demanding the Creation of a Standing Joint Task Force Headquarters.  

Science.gov (United States)

Secretary Cheney's 1990 Annual Report to the President and the Congress established the requirement for the Unified Commanders in Chief to be prepared for Third World conflict involving roles and missions requiring, 'mobile, highly ready, well equipped fo...

1990-01-01

395

The physics of tachyons. Pt. 2  

International Nuclear Information System (INIS)

This paper extends the development of a new formulation of the theory of tachyons to encompass the dynamics of tachyons. Energy and momentum are discussed along with the proper mass of a tachyon. The transformation of force in extended relativity (ER) is derived. Acceleration in ER is also discussed, as well as the relationship between force and acceleration. Two simple examples relating to the motion of a charged tachyon are discussed, followed by a brief explanation of why tachyons cannot emit Cerenkov radiation in a vacuum. 13 refs., 3 figs.

396

Nucleon transfer contribution to the absorptive heavy ion potential by the Monte Carlo simulation method  

Energy Technology Data Exchange (ETDEWEB)

The Monte Carlo simulation method is applied to calculate the nucleon transfer part of the imaginary optical-model potential in colliding heavy ions. In the process of transfer of nucleons from one nucleus to the other, forward and backward neutrons and protons are treated separately by taking into consideration the effect of the Coulomb forces and the potential energy surfaces (driving forces). The Pauli exclusion principle is also incorporated properly in the calculation.

1988-08-08

397

Member Login | Join / Register with EUGRIS  

Wastenet

...In 2000, the Water Framework Directive (WFD) came into force, introducing a comprehensive, river basin based water management for Europe. The aim of the Directive is ...In 2000, the Water Framework Directive (WFD) came into force, introducing a comprehensive, river basin based water management for Europe. The aim of the Directive ...

398

Investigation of free-forced convection flows in cavity-type receivers. Final yearly report, 1979-1980  

Energy Technology Data Exchange (ETDEWEB)

A summary is provided of the first of three years of experimental and theoretical research on free-forced convection flows in cavity-type solar receivers. New experimental and theoretical results are presented and discussed. The implication of these findings, with respect to the future thrust of the research program, is clarified as well as is possible at the present time. Following various related conclusions a summary and tentative schedule of work projected for year two of research are presented.

1982-01-01

399

Environmental Assessment of the Relocation and Construction of a Military Working Dog (MWD) Kennel.  

Science.gov (United States)

The United States Air Force (USAF) 460th Space Wing (460 SW) proposes to relocate and construct a Military Working Dog (MWD) kennel facility on Buckley Air Force Base (AFB) in response to changing land use surrounding the existing kennel and to accommodat...

2006-01-01

400

Designer's handbook for forced-cooled high-pressure oil-filled pipe-type cable systems. Final report  

Energy Technology Data Exchange (ETDEWEB)

This handbook provides the necessary tools for the engineer to design forced-cooled HPOF pipe-type cable systems. It represents the final objective of a major project which included an extensive research program at the Waltz Mill Forced-Cooling Test Facility. The formulas and procedures presented in this handbook are consistent with the results of this program as well as other full-scale and model investigations. Introductory material, including historical information, general design concepts and basic heat transfer and fluid dynamics theory is given for those who are unfamiliar with the fundamental principles of forced-cooling. The nucleus of the handbook consists of equations and calculating procedures for determining forced-cooled parameters and thermal/hydraulic performance levels. Both simple and sophisticated procedures have been provided, with the more complex procedures treating such areas as ...

1984-07-01

401

Autocontrol technique of combined centrifuges  

International Nuclear Information System (INIS)

The design characteristic of the autocontrol technique of the combined centrifuge is introduced. Digital technique, vary structure control and interface technique, graphical display techniques, digital communication technique as well as electronic technique are applied in the course of research. Automation in the operation of large scale combined centrifuges and the course of combined test has been realized and it can coordinate with other systems of status monitoring, data collecting and centrifugal force-aerodynamic force matched load automatically

2009-12-01

402

Acute Toxicity Evaluation of JP-8 Jet Fuel and JP-8 Jet Fuel Containing Additives.  

Science.gov (United States)

To reduce fuel fouling in current U.S Navy and Air Force aircraft systems and to provide additional heat sink and thermal stability for future systems, the Air Force is developing an improved JP-8 jet fuel (JP-8 + 100). Two companies (Betz and Mobil) have...

1996-01-01

403

Semi adiabatic theory of seasonal Markov processes  

Energy Technology Data Exchange (ETDEWEB)

The dynamics of many natural and technical systems are essentially influenced by a periodic forcing. Analytic solutions of the equations of motion for periodically driven systems are generally not known. Simulations, numerical solutions or in some limiting cases approximate analytic solutions represent the known approaches to study the dynamics of such systems. Besides the regime of weak periodic forces where linear response theory works, the limit of a slow driving force can often be treated analytically using an adiabatic approximation. For this approximation to hold all intrinsic processes must be fast on the time-scale of a period of the external driving force. We developed a perturbation theory for periodically driven Markovian systems that covers the adiabatic regime but also works if the system has a single slow mode that may even be slower than the driving force. We call it ...

1999-08-01

404

Subwavelength atom localization via amplitude and phase control of the absorption spectrum. II  

International Nuclear Information System (INIS)

Interaction of the internal states of an atom with spatially dependent standing-wave cavity field can impart position information of the atom passing through it leading to subwavelength atom localization. We recently demonstrated a different regime of atom localization [Phys. Rev. A 72, 013820 (2005)], namely sub-half-wavelength localization through phase control of electromagnetically induced transparency. This regime corresponds to extreme localization of atoms within a chosen half-wavelength region of the standing-wave cavity field. Here we present further investigation of the simplified model considered earlier and show interesting features of the proposal. We show how the model can be used to simulate a variety of energy-level schemes. Furthermore, the dressed-state analysis is employed to explain the emergence and suppression of the localization peaks, and the peak positions ...

2006-02-01

405

Behaviour of atomic oxygen in a pulsed dielectric barrier discharge measured by laser-induced fluorescence  

International Nuclear Information System (INIS)

Atomic oxygen is measured in a pulsed dielectric barrier discharge (DBD) using two-photon absorption laser-induced fluorescence (TALIF). The ground-level atomic oxygen is excited to the 3p "3P state by two-photon absorption at 226 nm. Negative (-40 kV) or positive (+30 kV) pulsed DBD occurs in an O_2-N_2 mixture at atmospheric pressure. The pulse width of the DBD current is approximately 50 ns. The TALIF experiment shows that the decay rate of atomic oxygen increases linearly with O_2 concentration. This result proves that atomic oxygen decays mainly by the third-body reaction, O + O_2 + M #-># O_3 + M. The rate coefficient of the third-body reaction is estimated to be 2.2 x 10"-"3"4 cm"6 s"-"1 in the negative DBD and 0.89 x 10"-"3"4 cm"6 s"-"1 in the positive DBD. It is shown that the decay rate of atomic oxygen increases linearly with humidity. This can explain the well-known ...

2005-08-21

406

Uses of laser optical pumping to produce polarized ion beams  

Energy Technology Data Exchange (ETDEWEB)

Laser optical pumping can be used to produce polarized alkali atom beams or polarized alkali vapor targets. Polarized alkali atom beams can be converted into polarized alkali ion beams, and polarized alkali vapor targets can be used to produce polarized H/sup -/ or /sup 3/He/sup -/ ion beams. In this paper the authors discuss how the polarized alkali atom beams and polarized alkali vapor targets are used to produce polarized ion beams with emphasis on the production of polarized negative ion beams.

1983-04-01

407

Production of polarized negative ion beams by collisional pumping  

Energy Technology Data Exchange (ETDEWEB)

The production of polarized negative ion beams by collisional pumping is described. Collisional pumping utilizes repeated charge changing collisions in a thick electron-spin-polarized gas or vapor target to form a polarized fast atom beam. The polarized fast atom beam is then partially converted into a polarized negative ion beam in a vapor target. Analysis is presented for a hydrogen beam passing through either a thick polarized H atom target or a thick polarized alkali target. Large polarizations and large currents may be possible.

1983-01-01

408

Production of polarized negative ion beams by ''collisional pumping''  

Energy Technology Data Exchange (ETDEWEB)

The production of polarized negative ion beams by ''collisional pumping'' is described. Collisional pumping utilizes repeated charge changing collisions in a thick electron-spin-polarized gas or vapor target to form a polarized fast atom beam. The polarized fast atom beam is then partially converted into a polarized negative ion beam in a vapor target. Analysis is presented for a hydrogen beam passing through either a thick polarized H atom target or a thick polarized alkali target. Large polarizations and large currents may be possible.

1984-03-01

409

Process for producing two-carbon atom oxygenated compounds from synthesis gas with minimal production of methane  

Energy Technology Data Exchange (ETDEWEB)

A process is claimed for selectively preparing a mixture of two-carbon atom oxygenated hydrocarbons, namely, acetic acid, ethanol and acetaldehyde, by continuously contacting a gaseous reaction mixture containing hydrogen and carbon monoxide with a solid catalyst comprising rhodium in combination with one or more alkali metals selected from the group consisting of lithium, potassium, cesium and rubidium at reaction conditions correlated so as to favor the formation of a substantial proportion of such two-carbon atom products.

1980-11-25

410

Observation of high-lying weak autoionizing resonances of Ne, and Mg atoms by charge-separated photoion-yield method  

Energy Technology Data Exchange (ETDEWEB)

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

2007-03-01

411

Observation of high-lying weak autoionizing resonances of Ne, and Mg atoms by charge-separated photoion-yield method  

International Nuclear Information System (INIS)

Doubly-excited 2s-12p-13pnp autoionizing resonance series of Ne atom as well as autoionizing resonances in the 2s region of Na and Mg atoms have been studied with monochromatized synchrotron radiation. Use of charge-separated photoion-yield method allowed us to detect these weak resonances in a clarified way in the yield curves of doubly-charged ions. The observed resonance states have been interpreted with the help of MCDF calculations, and the decay processes of these resonance states are discussed briefly.

2007-03-01

412

Method for determining the concentration of atomic species in gases and solids  

Energy Technology Data Exchange (ETDEWEB)

Method for determining the concentration of atomic species in gases and solids. Measurement of at least two emission intensities from a species in a plasma containing the species after a sufficient time period has elapsed after the generation of the plasma and during a second time period, permits an instantaneous temperature to be established within the sample. The concentration of the atomic species to be determined is then derived from the known emission intensity of a predetermined concentration of that species in the sample at the measured temperature, a quantity which is measured prior to the determination of the unknown concentration, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known concentration within the sample.

1999-01-01

413

Inhibition of Two-Photon Absorption in a Four-Level Atomic System with Closed-Loop Configuration  

International Nuclear Information System (INIS)

We theoretically investigate the features of two-photon absorption in a coherently driven four-level atomic system with closed-loop configuration. It is found that two-photon absorption can be completely suppressed just by properly adjusting the relative phase of four coherent low-intensity driving fields and the atomic system becomes transparent against two-photon absorption. From a physical point of view, we explicitly explain these results in terms of quantum interference induced by two different two-photon excitation channels.

2007-05-15

414

Dynamics of a H(n) atom in time-dependent electric and magnetic fields  

International Nuclear Information System (INIS)

The symmetry properties of the Coulomb potential allow for a dynamical spin-1/2 description of any fixed n level of a hydrogenlike atom in a time-dependent sufficiently weak electric and/or magnetic field. An explicit expression for the time dependence of the l,m amplitudes pertaining to a general n level is derived. The derivation follows on purely algebraic operations. Based on the derivation, we give analytical n-independent solutions to established and proposed schemes for driving the atom into a high angular-momentum state.

2002-05-01

415

Differential anomalous-x-ray-scattering study of icosahedral and amorphous Pd/sub 58.8/U/sub 20.6/Si/sub 20.6/  

International Nuclear Information System (INIS)

The total and differential atomic pair-correlation functions of an icosahedral (quasicrystalline) solid were determined for the first time, directly by the differential anomalous-x-ray-scattering technique using synchrotron radiation. The observed atomic distances involving uranium atoms in icosahedral Pd/sub 58.8/U/sub 20.6/Si/sub 20.6/ suggest the presence of a quasicrystalline sublattice with vertex decoration. The pair distribution functions in the icosahedral and amorphous phases are similar up to the second-nearest neighbors, or up to 6 A-circle.

416

Differential anomalous-x-ray-scattering study of icosahedral and amorphous Pd/sub 58. 8/U/sub 20. 6/Si/sub 20. 6/  

Energy Technology Data Exchange (ETDEWEB)

The total and differential atomic pair-correlation functions of an icosahedral (quasicrystalline) solid were determined for the first time, directly by the differential anomalous-x-ray-scattering technique using synchrotron radiation. The observed atomic distances involving uranium atoms in icosahedral Pd/sub 58.8/U/sub 20.6/Si/sub 20.6/ suggest the presence of a quasicrystalline sublattice with vertex decoration. The pair distribution functions in the icosahedral and amorphous phases are similar up to the second-nearest neighbors, or up to 6 A-circle.

1986-07-07

417

Comparison of EH with SW-Xsub(alpha) calculations. Electronic structure of 3d, 4d, and 5d metal atom clusters  

Energy Technology Data Exchange (ETDEWEB)

The electronic structure of octahedral metal atom clusters Me/sub 6/ of 3d, 4d, and 5d transition metal atoms (V, Cr; Nb, Mo; Ta, W) has been calculated applying two different quantum-chemical approximation methods (Extended Hueckel (EH) method; SW-Xsub(alpha) method). Equilibrium structures, energy level schemes, Fermi energies and band widths as well as densities of states of clusters are discussed in detail.

1981-01-01

418

An experimental and molecular-statistical study of the adsorption of the iodobenzene, 2-iodothiophene, and isomeric iodoadamantane molecules on the graphite basal face surface  

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption of iodobenzene, 2-iodothiophene, and 1- and 2-iodoadamantanes on the surface of graphitized thermal carbon black were determined experimentally. The influence of the special features of the molecular structure of the adsorbates on the thermodynamic characteristics of adsorption was studied. The atom-atom approximation of the semiempirical molecular-statistical theory of adsorption was used to calculate the thermodynamic characteristics of adsorption of the adsorbates using the newly determined potential function parameters of pair intermolecular interaction (?(r)) of I with C atoms of the basal graphite face. For the example of isostructural monohalogenated benzenes, thiophenes, and adamantanes, a comparative analysis of the contributions of ...

2011-01-01

419

notes4.htm - NASA's History Office  

Science.gov (United States)

Subcommittee of the Joint Committee on Atomic Energy of the United States, Outer Space Propulsion by Nuclear Energy, hearings, 85th Cong., 2d sess., 22, ...

420

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

421

Untitled - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Joint Committee on Atomic Energy. Comgress of the United States. Washington, D. C.. 1 - Chief, Life Sciences Division. A m y Research Office ...

422

Total interaction cross sections and effective atomic numbers of some biologically important compounds containing H, C, N and O in the energy range 6.4-136 keV  

International Nuclear Information System (INIS)

The total interaction cross sections (#sigma#_t) of some sugars and amino acids and five elements: lithium, carbon, oxygen, aluminium and calcium have been measured for 6.4 keV, 13.95 keV, 14.4 keV, 17.74 keV, 24.14 keV, 30.8 keV, 35 keV, 59.54 keV, 81 keV, 122 keV and 136 keV photons in a narrow beam good geometry set up, by using high resolution detectors such as a Si-PIN diode detector and a high purity germanium detector. The #sigma#_t values have been used in a matrix method to evaluate the effective atomic numbers Z_e_f_f of the samples from their effective atomic cross sections #sigma#_a. The effective atomic cross section of a sample #sigma#_a is the total interaction cross section divided by the total number of atoms of all types in it. Further, a quantity called the effective atomic weight A_e_f_f of a sample was defined as the ratio of the molecular weight A to the total ...

2007-09-28

425

Reactions of the inner surface of carbon nanotubes and nanoprotrusion processes imaged at the atomic scale  

British Library Electronic Table of Contents (United Kingdom)

Although the outer surface of single-walled carbon nanotubes (atomically thin cylinders of carbon) can be involved in a wide range of chemical reactions, it is generally thought that the interior surface of nanotubes is unreactive. In this study, we show that in the presence of catalytically active atoms of rhenium inserted into nanotubes, the nanotube sidewall can be engaged in chemical reactions from the inside. Aberration-corrected high-resolution transmission electron microscopy operated at 80?keV allows visualization of the formation of nanometre-sized hollow protrusions on the nanotube sidewall at the atomic level in real time at ambient temperature. Our direct observations and theoretical modelling demonstrate that the nanoprotrusions are formed in three stages: (i) metal-assisted d...

2011-01-01

426

Radiative corrections to the atomic levels in a periodic electromagnetic field  

Energy Technology Data Exchange (ETDEWEB)

The influence of a periodic electromagnetic field on the radiative corrections to the atomic energy levels is studied for the case of ''strong fields'' for which the interaction between the atom and field is of the order or greater than the radiative effects. The analysis is carried out on the basis of the Schwinger-Dirac equation for the propagation function of a bound electron in the field and on the basis of the density matrix in the Furry representation. It is shown that in the strong field approximation the radiative shifts and widths are manifest as radiative corrections to the quasi-energies. In super-high resolution experiments intensity effects in the radiative corrections to the atomic levels are obtained in the case of single-photon resonance. Some multiphoton processes are condidered by taking into account the effect of the field on the radiative structure of the levels.

1982-12-01

427

Quantum Information Processing Using Local Control of ...  

Science.gov (United States)

... The insu- lation between gate and nanowire is the high-k dielectric HfO2, deposited by atomic layer depo- sition (ALD). ...

2006-12-31

428

Quantification of order in the liquid at a solid-liquid interface by High-Resolution Transmission Electron Microscopy (HRTEM)  

Energy Technology Data Exchange (ETDEWEB)

A number of different theoretical approaches have been used to model to atomic structure and properties of solid-liquid interfaces. Most calculations indicate that ordering occurs in the first several layers of the liquid, adjacent to the crystal surface. In contrast to the numerous theoretical investigations, there have been no direct experimental observations of the atomic structure of a solid-liquid interface for comparison. Saka et al. examined solid-liquid interfaces in In and In-Sb at lattice-fringe resolution in the TEM, but their data do not reveal information about the atomic structure of the liquid phase. The purpose of this study is to determine the atomic structure of a solid-liquid interface using a highly viscous supercooled liquid, i.e., a crystal-amorphous interface.

1996-12-31

429

PRICES SUBJECT To CHq.G - NASA Technical Report Server (NTRS)  

Science.gov (United States)

by the radionuclide X-ray fluorescence analysis into several groups according to the atomic number of the determined element. Table I documents this. ...

430
431

Laboratory studies of the sensitivity of tropospheric ozone to the chemistry of sea salt aerosol. Final report, September 15, 1993--September 14, 1994  

Energy Technology Data Exchange (ETDEWEB)

Ozone plays a critical role in both the chemistry and radiation balance of the troposphere. Understanding the factors controlling tropospheric ozone levels is critical to our understanding of a variety of issues in global chemistry and climate change. Chlorine atoms have the potential to contribute significantly to the ozone balance in the free troposphere. They can react directly with ozone or alternately, with organics and may actually lead to the formation of ozone in the presence of sufficient NO. Reactions of alkali halides in sea salt particles are a potential source of atomic chlorine, hence reactions of these alkali halides, especially those producing precursors to atomic chlorine, are of great interest. Finally, the mechanisms, intermediates and products of the Cl-biogenic reactions are unknown; these could serve as unique markers of chlorine atom chemistry in the troposphere, and hence are ...

1994-11-15

432

Iran's Nuclear Program: Tehran's Compliance with ...  

Science.gov (United States)

... 25 Nonproliferation Treaty, Senate Committee on Foreign Relations, Joint Committee on Atomic Energy [Part 1] July 10-12, 17, 1968; Session 90-2 ...

2008-12-04

434

Genesis : Search for Origins | JPL | NASA  

Science.gov (United States)

(telescopes, cameras, mirrors, solar cookers); Explain to students that the Genesis spacecraft has a concentrator that collects special types of atoms from ...

435

Formation of pentagonal Cu nano wires  

Energy Technology Data Exchange (ETDEWEB)

The development of nano/molecular devices will require atomic-sized electrical contacts or nano metric conductors for wiring. As metal nano wires exhibit quantized conductance at room temperature, quantum transport effects will play an important role in the practical implementation of nano devices. As copper is currently used as interconnecting metal in standard microelectronics, the characterization of Cu nano wire properties deserves special attention. In this work, we show a detailed study of structural and electronic properties of atomic-sized Cu wires. In particular, we have established a complete correlation between the conductance and the structure by associating real-time atomic resolution transmission electron microscopy imaging with molecular dynamic simulations, conductance measurements and conductance calculations. Our study has revealed the structural relaxation of Cu wires forming a pentagonal ...

2004-07-01

436

Effects of ion irradiation on the diffusion of pre-implanted B atoms in crystalline silicon  

International Nuclear Information System (INIS)

N-type crystalline Si (100) implanted with 5 keV B ions was subsequently irradiated with MeV Si, O and F ions. The B atom profiles were measured by means of secondary ion mass spectrometer after the treatment of rapid thermal annealing. The results show that the transient enhanced diffusion of B atoms is effectively limited by the post-implantation of high energy ions at high dose. At the same irradiation conditions, it is found that the existence of a SiO_2 layer in the near surface of Si is even more effective in suppressing the transient enhanced diffusion of the doped B atoms. The results are qualitatively discussed in combination with the analyses of RBS/c measurements and calculation of the DICADA code

2001-12-01

439

Diffusion of adatoms on face-centered cubic transition metal surfaces  

Energy Technology Data Exchange (ETDEWEB)

Mechanisms and associated energetics for adatom diffusion on the (100) and (110) surfaces of Ni, Cu, Rh, Pd, and Ag are investigated. Self-diffusion was studied on (100) and (I 10) surfaces of Ni, Cu, Pd and Ag using corrected effective medium method (CEM) and approximation to CEM used for molecular dynamics and Monte Carlo studies (MD/MC-CEM). Self-diffusion on Pd(100), Ag(100), Ni(110), Cu(110), Pd(110), and Ag(110) is accomplished by classical diffusion: the adatom hops from its equilibrium adsorption site over an intervening bridge site to an adjacent equilibrium site. Self-diffusion on Ni(100) and Cu(100) proceeds by atomic-exchange diffusion: the adatom on the surface displaces an atom in the first surface layer. Aside from explicit inclusion of the kinetic-exchange-correlation energy, it is critical to include enough movable atoms in the calculation to insure correct energetics. Distortions induced by these diffusion ...

1994-05-10

441

Coupled two-component atomic gas in an optical lattice  

CERN Document Server

We study the ground state of an ideal coupled two-component gas of ultracold atoms in a one dimensional optical lattice, either bosons or fermions. Due to the internal two-level structure of the atoms, the Brillouin zone is twice as large as imposed by the periodicity of the lattice potential. This is reflected in the Bloch dispersion curves, where the energy bands regularly possess several local minima. As a consequence, when the system parameters are tuned across a resonance condition, a non-zero temperature topological first order phase transition occurs which arises from an interplay between initernal and kinetic atomic energies. It is shown that these phenomena are also captured for two and three dimensional optical lattices.

2008-01-01

443

CONSOLIDATED TRANSLATION SURVEY. NUMBER 91 ...  

Science.gov (United States)

... AEC - Atomic Energy Commission (see CFSTI) AERE Harwell Lib The Librarian AERE, Ministry of Supply Harwell, Didcot, Birks England AF ...

1965-07-01

444

Breakthrough Image of Atomic Bonding Will Advance the Science of New Materials  

Science.gov (United States)

... Schioler (703) 306-1836 lschiole@nsf.gov This material is available primarily for archival purposes ... of superconducting materials. Colossal magnetoresistance materials are those in which the electrical ...

445

BRAZING AND BONDING OF COLUMBIUM, MOLYBDENUM ...  

Science.gov (United States)

... Kingdom Atomic Energy Authority, .... G. .. aphit. J..int. Report No. AERE R/M 165 (April, 1958). (2) Slaughter, G. M., Metallurgy ...

1962-06-11

446

BIBLIOGRAPHY OF TECHNICAL PUBLICATIONS AND ...  

Science.gov (United States)

... (l0)6o). 316. Statf,'ent. In Hearings before the Subcommittee on Research, Do'v,-Iopment, and Radiation of the Joint Committee on Atomic Energy. ...

1967-07-01

449

An experimental and molecular-statistical study of the adsorption of the iodobenzene, 2-iodothiophene, and isomeric iodoadamantane molecules on the graphite basal face surface  

Science.gov (United States)

The thermodynamic characteristics of adsorption of iodobenzene, 2-iodothiophene, and 1- and 2-iodoadamantanes on the surface of graphitized thermal carbon black were determined experimentally. The influence of the special features of the molecular structure of the adsorbates on the thermodynamic characteristics of adsorption was studied. The atom-atom approximation of the semiempirical molecular-statistical theory of adsorption was used to calculate the thermodynamic characteristics of adsorption of the adsorbates using the newly determined potential function parameters of pair intermolecular interaction (?( r)) of I with C atoms of the basal graphite face. For the example of isostructural monohalogenated benzenes, thiophenes, and adamantanes, a comparative analysis of the contributions of the F, Cl, Br, and I atoms to the thermodynamic characteristics of adsorption was performed for the nonspecific adsorption of these ...

2011-04-01

450

A computational study of aluminum phosphide nanotubes  

British Library Electronic Table of Contents (United Kingdom)

Abstract Electronic structures of two representative zigzag and armchair models of aluminum phosphide nanotube (AlPNT) were investigated by density functional theory calculations. The structures were optimized and the bond lengths, tip diameters, band gaps, and dipole moments were calculated. Moreover, the quadrupole coupling constants (CQ) were calculated for the Al-27 atoms of the optimized structures. The same values of AlP bond lengths were calculated for both models. The larger value of band gap of armchair model than the zigzag model indicated the stronger dielectric property for the former model. The values of CQ(27Al) were the largest for the Al atoms placed at the tips of both zigzag and armchair AlPNT than other Al atoms, which could reveal dominant role of the Al atoms placed at...

2011-01-01

451

A Simple Scheme for Realizing a Multiqubit Controlled-Phase Gate Through a Resonant Interaction of Three-Level Atoms with a Single-Mode Cavity  

International Nuclear Information System (INIS)

A very simple theoretical scheme is proposed to implement two- and three-qubit controlled-phase gates firstly only using a single resonant interaction between ladder-type three-level atoms and the single-mode cavity. In the presented protocol, the quantum information is encoded on the stable ground states of the atoms (as the controlling qubits) and the zero- and one-photon Fock states of cavity-field (as the target qubit). Under the influence of the atomic spontaneous emission, the decay of the cavity-mode, and deviation of the coupling strength, the three-qubit controlled-phase gate may have a comparatively high fidelity. The experimental feasibility of controlled-phase gate and the case that is extended to realize N-qubit controlled-phase gate are also discussed. (general)

2010-03-15

452

Assessment of the impact of the greenhouse gas emission and sink scenarios in Finland on radiative forcing and greenhouse effect  

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is to study greenhouse gas emissions and sinks and their greenhouse impact as a function of time. The greenhouse impact is expressed in terms of global average radiative forcing, which measures the perturbation in the Earth`s radiation budget. Radiative forcing is calculated on the basis of the concentration changes of the greenhouse gases and the radiation absorption properties of the gases. It takes into account the relatively slow changes in the concentrations due to natural removal and transformation processes and also allows a comparison of the impact of various greenhouse gases and their possible control options as a function of time. In addition to the applications mentioned above, the anthropogenic greenhouse gas emission histories of Nordic countries have been estimated, and the radiative forcing caused by them has been calculated with REFUGE. The dynamic impact of aerosol emissions both ...

1996-12-31

453

Aerosol-induced changes of convective cloud anvils produce strong climate warming  

Science.gov (United States)

The effect of aerosol on clouds poses one of the largest uncertainties in estimating the anthropogenic contribution to climate change. Small human-induced perturbations to cloud characteristics via aerosol pathways can create a change in the top-of-atmosphere radiative forcing of hundreds of Wm-2. Here we focus on links between aerosol and deep convective clouds of the Atlantic and Pacific Intertropical Convergence Zones, noting that the aerosol environment in each region is entirely different. The tops of these vertically developed clouds consisting of mostly ice can reach high levels of the atmosphere, overshooting the lower stratosphere and reaching altitudes greater than 16 km. We show a link between aerosol, clouds and the free atmosphere wind profile that can change the magnitude and sign of the overall climate radiative forcing. We find that increased aerosol loading is associated with taller cloud towers and anvils. The taller clouds ...

2010-05-01

454

Thermal Casimir-van der Waals Interaction between Randomly Charged Dielectrics  

CERN Document Server

Monopolar charge disorder effects are studied in the context of fluctuation-induced interactions between neutral dielectric slabs. It is shown that quenched bulk charge disorder gives rise to an additive contribution to the net interaction force which decays as the inverse distance between dielectric surfaces. This effect may thus completely mask the standard Casimir--van der Waals effect. By contrast, annealed (bulk or surface) charge disorder leads to a net interaction force whose large-distance behavior coincides with the universal Casimir force between perfect conductors, which scales as inverse cubic distance, and the dielectric properties enter only in subleading corrections.

2009-01-01

455

Tea catechins prevent contractile dysfunction in unloaded murine soleus muscle: A pilot study  

British Library Electronic Table of Contents (United Kingdom)

ObjectiveExtended periods of muscle disuse, physical inactivity, immobilization, and bedrest result in a loss of muscle mass and a decrease in muscle force, which are accompanied by an increase in oxidative stress. We investigated the effects of the intake of green tea catechins on unloading-induced muscle dysfunction in tail-suspended mice. MethodsTen-week-old male BALB/c mice were fed a purified control diet or a diet containing 0.5% tea catechins for 14 d. Thereafter, the mice were subjected to continuous tail suspension for 10 d. On the final day, muscle mass, contractile force production, antioxidant potential, and carbonylated protein levels were evaluated. ResultsHind limb unloading caused a loss of soleus muscle weight and muscle force. Intake of tea catechins significantly inhibit...

2011-01-01

456

Solution of free vibration equations of semi-rigid connected Reddy?Bickford beams resting on elastic soil using the differential transform method  

British Library Electronic Table of Contents (United Kingdom)

The literature regarding the free vibration analysis of Bernoulli?Euler and Timoshenko beams under various supporting conditions is plenty, but the free vibration analysis of Reddy?Bickford beams with variable cross-section on elastic soil with/without axial force effect using the Differential Transform Method (DTM) has not been investigated by any of the studies in open literature so far. In this study, the free vibration analysis of axially loaded and semi-rigid connected Reddy?Bickford beam with variable cross-section on elastic soil is carried out by using DTM. The model has six degrees of freedom at the two ends, one transverse displacement and two rotations, and the end forces are a shear force and two end moments in this study. The governing differential equations of motion of the r...

2011-01-01

457

Simulation study of feedback systems based on a two-tap FIR filter. Under beam-beam collisions  

Energy Technology Data Exchange (ETDEWEB)

The performance of bunch-feedback systems based on two-tap FIR filters is discussed, particularly for transverse cases. Since they are the simplest type of FIR digital filters, the two-tap FIR filters should be suited to systems that require a very fast processing speed. However, in these feedback systems, a bunch must turn along a ring several times from the position-measurement to feedback kicking. Within these turns, irregular phase-jumps in the betatron motion can occur, due to several causes, such as the wake forces and beam-beam force. The discussion given in this paper is focussed on the effect of beam-beam collisions on these feedback systems. Based on linear theory and simulation studies, it has been found that these feedback systems can work with good performance, even under the influence of a strong beam-beam force. (author)

1998-04-01

458

Numerical modeling of a MEMS actuator considering several magnetic force calculation methods  

British Library Electronic Table of Contents (United Kingdom)

Purpose - The purpose of this paper is to investigate the accuracy of different force calculation methods and their impact on mechanical deformations. For this purpose, a micrometer scaled actuator is considered, which consists of a micro-coil and of a permanent magnet (PM) embedded in a deformable elastomeric layer. Design/methodology/approach - For the magnetic field evaluation a hybrid numerical approach (finite element method/boundary element method (FEM/BEM) coupling and a FEM/BEM/Biot-Savart approach) is used, whereas FEM is implemented for the mechanical deformation analysis. Furthermore, for the magneto-mechanical coupling several force calculation methods, namely the Maxwell stress tensor, the virtual work approach and the equivalent magnetic sources methods, are considered and co...

2011-01-01

459

Measuring capacity development and reform in the Royal Solomon Islands Police Force  

British Library Electronic Table of Contents (United Kingdom)

International police have been deployed on a number of peacekeeping missions, but providing capacity development and assisting in reform of local police in war-torn nations are only a relatively recent undertaking. The process of police reform is complicated because of the inherent difficulty in evaluating the impact of a development programme on police service delivery performance. This study reports on the results of a pilot survey of international police managers assessment of the level of competency of the Royal Solomon Islands Police Force following the introduction of a capacity development programme 3 years earlier. The results indicate that although the local police had improved operationally, and in some cases to an international standard, the Force had lower capability in strateg...

2010-01-01

460

Jamming in granular hopper flow.  

Energy Technology Data Exchange (ETDEWEB)

Large-scale three dimensional molecular dynamics simulations of hopper flow are presented. The flow rate of the system is controlled by the width of the aperture at the bottom. As the steady-state flow rate is reduced, the force distribution P(f) changes only slightly, while there is a large change in the impulse distribution P(i). In both cases, the distributions show an increase in small forces or impulses as the systems approach jamming, the opposite of that seen in previous Lennard-Jones simulations. This occurs dynamically as well for a hopper that transitions from a flowing to a jammed state over time. The final jammed P(f) is quite distinct from a poured packing P(f) in the same geometry. The change in P(i) is a much stronger indicator of the approach to jamming. The formation of a peak or plateau in P(f) at the average force is not a general feature of the approach to jamming.

2005-06-01

461

Investigation of mixed convection in a large rectangular enclosure  

Energy Technology Data Exchange (ETDEWEB)

This experimental research investigates mixed convection and heat transfer augmentation by gaseous forced jets in a large enclosure, at conditions simulating those of passive containment cooling systems for Gen III+ passively safe reactors. The experiment is designed to measure the key parameters governing heat transfer augmentation by forced jets, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest for mixing and stratification phenomena in containments under accident conditions. Correlations for heat transfer augmentation by forced jets are developed and compared with experimental data. The characteristic recirculation speed inside the enclosure is introduced and analyzed. Steady stratified temperature distributions are compared ...

2007-05-15

462

Investigation of mixed convection in a large rectangular enclosure  

International Nuclear Information System (INIS)

This experimental research investigates mixed convection and heat transfer augmentation by gaseous forced jets in a large enclosure, at conditions simulating those of passive containment cooling systems for Gen III+ passively safe reactors. The experiment is designed to measure the key parameters governing heat transfer augmentation by forced jets, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest for mixing and stratification phenomena in containments under accident conditions. Correlations for heat transfer augmentation by forced jets are developed and compared with experimental data. The characteristic recirculation speed inside the enclosure is introduced and analyzed. Steady stratified temperature distributions are compared ...

2007-05-01

463

Effect of the induced magnetic field on peristaltic flow of a couple stress fluid  

Science.gov (United States)

We have analyzed the MHD flow of a conducting couple stress fluid in a slit channel with rhythmically contracting walls. In this analysis we are taking into account the induced magnetic field. Analytical expressions for the stream function, the magnetic force function, the axial pressure gradient, the axial induced magnetic field and the distribution of the current density across the channel are obtained using long wavelength approximation. The results for the pressure rise, the frictional force per wave length, the axial induced magnetic field and distribution of the current density across the channel have been computed numerically and the results were studied for various values of the physical parameters of interest, such as the couple stress parameter ?, the Hartmann number M, the magnetic Reynolds number R and the time averaged mean flow rate ?. Contour plots for the stream and magnetic force functions are obtained and ...

2008-06-01

464

Ecological footprint and major driving forces in West Jilin Province, Northeast China  

British Library Electronic Table of Contents (United Kingdom)

The environmental impact caused by local people (ecological footprint of consumption, EFc) and the actual environmental impact that the ecosystem burdens (ecological footprint of production, EFp) in West Jilin Province, Northeast China from 1986 to 2006 were evaluated by using ecological footprint (EF) method. And the major driving forces of EFc and EFp were analyzed by STIRPAT model. Both EFc and EFp showed increasing trends in 1986?2006, accompanied by decreasing ecological deficits but expanding ecological overshoots. Population (P), GDP per capita (A 1), quadratic term of GDP per capita (A 2), urbanization (T a1), and quadratic term of urbanization (T a2) were important influencing factors of EFc, among which T a2 and T a1 were the most dominate driving forces of EFc. A 1, A 2 and T a2...

2010-01-01

465

Developing a standardized test procedure for hybrid vehicles: The challenge of the SAE HEV task force  

Energy Technology Data Exchange (ETDEWEB)

In 1992, the Society of Automotive Engineers (SAE) established a task force to develop a procedure for measuring electric energy consumption, all-electric range, fuel economy, and exhaust emissions for hybrid vehicles; the procedure will be submitted to regulatory agencies as representing the automotive industry`s recommendations. The draft procedure is currently being tested on hybrid vehicles. The University of Maryland`s parallel hybrid was tested in September 1994, and the University of California-Davis` parallel hybrid and the University of Illinois` series hybrid will be tested in November 1994 and January 1995, respectively. The procedure is being modified to incorporate any lessons learned, and the task force hopes to recommend the final procedure to the SAE by mid 1995.

1994-11-01

466

Coordinated control of multiple manipulator systems  

Energy Technology Data Exchange (ETDEWEB)

A scheme for controlling multimanipulator systems is presented. The control objective is to coordinate the manipulators to perform parts-matching tasks such as screwing a nut onto a bolt. The task of moving a rigid object can be treated as a special case. Two secondary control objectives internal force control and load distribution can be accomplished within the structure of the control law. The internal force control mechanism keeps the internal forces on the object being manipulated at a desirable level. The load distribution mechanism distributes control effort to each manipulator according to a weighting factor. It is also shown that the control algorithm has a modular structure which facilitates its implementation on a multiprocessor computer. The scheme was tested on a planar scara type dual-manipulator system. A series of experimental results is included to demonstrate the system performance under various conditions.

1993-08-01

467

A new model for precision control of the radius in in-plane roll-bending of strip considering rolls and stand deflections  

British Library Electronic Table of Contents (United Kingdom)

The rolls and stand deflections induced by rolling force lead to a significant decrease in the radius prediction accuracy of the ring product in the in-plane roll-bending of strip. To precisely predict the deflections and control the radius, a new analytical model is developed. Numerical implementation is presented to solve the theoretical rolling force, the deflections as well as the inherent force-deflection relationship considering the interactions of the strip workpiece, the rolls and the stand. A series of profile measurements of the formed ring parts are made to assess the accuracy of the predicted deflections. Different control approaches are used in the experiments to validate the radius control model. The experimental results show that the model is reliable to control the radii wi...

2011-01-01

468

The physics of Electron Beam Ion Sources  

Energy Technology Data Exchange (ETDEWEB)

There are 13 Electron Beam Ion Sources in operation which produce highly charged ions, up to Th[sup 80+] and Xe[sup 53+]. Most of the sources are used to study these ions under electron impact or when recombining with gaseous or solid targets. That provides an insight into the atomic physics of these highly charged ions and into the physics of the plasma in which such ions can be found. This paper reviews the present knowledge of atomic processes, important in the production of such ions with an EBIS.

1990-01-01

469

The physics of Electron Beam Ion Sources  

Energy Technology Data Exchange (ETDEWEB)

There are 13 Electron Beam Ion Sources in operation which produce highly charged ions, up to Th{sup 80+} and Xe{sup 53+}. Most of the sources are used to study these ions under electron impact or when recombining with gaseous or solid targets. That provides an insight into the atomic physics of these highly charged ions and into the physics of the plasma in which such ions can be found. This paper reviews the present knowledge of atomic processes, important in the production of such ions with an EBIS.

1990-12-31

470

Single Atom Detection With Optical Cavities  

CERN Document Server

We present a thorough analysis of single atom detection using optical cavities. The large set of parameters that influence the signal-to-noise ratio for cavity detection is considered, with an emphasis on detunings, probe power, cavity finesse and photon detection schemes. Real device operating restrictions for single photon counting modules and standard photodiodes are included in our discussion, with heterodyne detection emerging as the clearly favourable technique, particularly for detuned detection at high power.

2008-01-01

471

Observation of inverse predissociation of spin-polarized atomic hydrogen at low temperatures  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the two-body recombination of spin-polarized atomic hydrogen in a magnetic field of 40 kG have been extended to temperatures above 0.5/sup 0/K. The rate constant for the formation of parahydrogen shows an unexpected increase with temperature, which is explained by inverse predissociation into the v = 14,J = 4 level of H/sub 2/. Data indicate the level is bound by 0.7 +- 0.1/sup 0/K.

1986-10-01

472

Nuclear Regulatory Commission issuances. Vol. 19, No. 4  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during April 1984 from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

1984-04-01

473

Nuclear Regulatory Commission issuances. Vol. 16, No. 4  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions For Rulemaking (DPRM).

1982-10-01

474

Nuclear Regulatory Commission issuances. Vol. 16, No. 1  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during the specified period from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Director's Decisions (DD), and the Denials of Petitions For Rulemaking (DPRM).

1982-07-01

475

Nuclear Regulatory Commission issuances, Volume 18, No. 5  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during November, 1983, from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

1983-11-01

476

Nuclear Regulatory Commission issuances, January 1984. Vol. 19, No. 1  

Energy Technology Data Exchange (ETDEWEB)

This report includes the issuances received during January 1984 from the Commission (CLI), the Atomic Safety and Licensing Appeal Boards (ALAB), the Atomic Safety and Licensing Boards (LBP), the Administrative Law Judge (ALJ), the Directors' Decisions (DD), and the Denials of Petitions for Rulemaking (DPRM).

1984-01-01

477

Nuclear Raman processes and the development of gamma-ray lasers  

International Nuclear Information System (INIS)

This review briefly describes current efforts to develop superradiant sources of coherent radiation for the sub-nanometer range of wavelenghs, using nuclear rather than the atomic or molecular transitions that are stimulated in existing lasers. First the radiative (including Raman) interactions of nuclei with those of atoms and molecules are compared; then the present status of research on the fundamental problems involved in stimulating nuclear gamma radiation is described. (author). 20 refs.; 2 figs.

478

Extent and significance of the impact on reactor licensing of recent court decisions. Hearing before the Joint Committee on Atomic Energy, Congress of the United States, Ninety-Fourth Congress, Second Session, August 27, 1976  

Science.gov (United States)

A report is presented of a hearing conducted before the Joint Committee on Atomic Energy on August 27, 1976, to discuss the legal implications for reactor licensing resulting from court challenges to procedures for assessing the environmental impact of radioactive waste disposal. (DG)

1976-01-01

479

Effect of the Wigner-Seitz boundary conditions on internal conversion coefficients  

Energy Technology Data Exchange (ETDEWEB)

Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions.

1984-05-01

480

Effect of the Wigner-Seitz boundary conditions on internal conversion coefficients  

International Nuclear Information System (INIS)

Solid state effects are taken into account in an internal conversion coefficients computation by using Wigner-Seitz boundary conditions. Both the bound and free electron wave functions are calculated from an atomic Dirac-Hartree-Fock-Slater self consistent potential. These internal conversion coefficients are compared with those obtained from the usual free atom boundary conditions. (orig.).

481

Double-electron-capture cross section for I/sup +/ in a magnesium-vapor target  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the double-electron-capture process in which a positive ion of iodine becomes a negative ion in a single collision with a magnesium atom are reported between 20 and 90 keV. The cross section is comparable to that for the rare gases and not as large as might be expected from a two-valence-electron atom. This process is probably insignificant in the production of negative ion beams using a magnesium-vapor target.

1987-06-15

482

Determination of the /sup 242m/Am nuclear moments  

Energy Technology Data Exchange (ETDEWEB)

The hyperfine structure of Am atoms was investigated in an atomic beam by laser spectroscopy. The observed splittings were evaluated with respect to the magnetic dipole and electric quadrupole moments of /sup 242m/Am. The results are: ..mu../sub I/(/sup 242m/Am) = +0.97(5) nm, Q(/sup 242m/Am) = +6.5(2.0) b.

1988-07-01

483

Comparison of EH with SW-Xsub(alpha) calculations  

International Nuclear Information System (INIS)

The electronic structure of octahedral metal atom clusters Me_6 of 3d, 4d, and 5d transition metal atoms (V, Cr; Nb, Mo; Ta, W) has been calculated applying two different quantum-chemical approximation methods (Extended Hueckel (EH) method; SW-Xsub(alpha) method). Equilibrium structures, energy level schemes, Fermi energies and band widths as well as densities of states of clusters are discussed in detail.

1981-01-01

484

Collisional-radiative model for highly stripped ions  

Energy Technology Data Exchange (ETDEWEB)

Collisional-Radiative numerical models are commonly used to design or interpret experiments in atomic physics of laser-created plasmas, including X-ray laser studies. We describe our new code containing several options: average ion, more or less detailed configurations. It consists of an atomic data base coupled to subroutines evaluating ionic populations and emission and absorption coefficients. Numerical results are given to illustrate the capabilities of the code and to compare different models and types of approximation.

1986-10-01

485

A nanoscale understanding of the adhesion of polybutylene terephthalate on aluminum  

British Library Electronic Table of Contents (United Kingdom)

The adhesion strength of polybutylene terephthalate (PBT) on aluminum was investigated using density functional theory-based total energy calculations. Aluminum atom was connected to a PBT monomer at different orientations and total energies were calculated in order to determine the most stable orientation. The energy differences showed that the Al oriented at 180degree with the ester group of the monomer bonded strongly. Using this orientation, the PBT monomer-adhesion on aluminum surface and the aluminum atom adhesion on PBT bulk were also investigated.

2007-01-01

486

The impact of nitrogen co-implantation on boron ultra-shallow junction formation and underlying physical understanding  

International Nuclear Information System (INIS)

In this paper, we show that boron transient enhanced diffusion can be reduced to different extents by varying the distribution of nitrogen atoms in the junction. This is attributed to the relative location of nitrogen atoms with respect to boron profile and end-of-range defect band, affecting the interactions between dopants and defects upon annealing. In addition, variations in boron dopant activation and deactivation are also observed. Similar to fluorine co-implantation, it is proposed that nitrogen atoms react with vacancy point defects to form nitrogen-vacancy clusters that will trap the interstitials emitted from end-of-range defects. However, we report that the interstitial sink efficiency of nitrogen atoms is not as good as the co-implanted carbon atoms, which is noticed from the dopant deactivation curves. In terms of extended defect evolution, the results clearly indicate ...

2008-12-05

487

Spontaneous emission spectra and simulating multiple spontaneous generation coherence in a five-level atomic medium  

Science.gov (United States)

We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to SGC reported by Fountoulakis et al. [Phys. ...

2006-09-15

488

Correlated charge-changing ion-atom collisions. Progress report, February 16, 1990--February 15, 1993  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant DE-FG02-87ER13778 from February 16, 1990 through February 15, 1993. This work involves the experimental investigation of atomic interactions in collisions of charged projectiles with neutral targets or electrons, with particular emphasis on two-electron interactions and electron-correlation effects. The processes studied are of interest both from fundamental and applied points of view. In the latter case, results are obtained which are relevant to the understanding of laboratory and astrophysical plasmas, highly-excited (Rydberg) and continuum states of atoms and ions, atomic structure effects, the interaction of ions with surfaces, and the development of heavy-ion storage-rings. The results obtained have provided the basis for several M.A. thesis projects at Western Michigan and several ...

1993-02-01

489

Whey protein isolate attenuates strength decline after eccentrically-induced muscle damage in healthy individuals  

UK PubMed Central (United Kingdom)

BackgroundWe examined the effects of short-term consumption of whey protein isolate on muscle proteins and force recovery after eccentrically-induced muscle damage in healthy individuals.MethodsSeventeen...Full Text Available

490

Three-Dimensional Traction Force Microscopy: A New Tool for Quantifying Cell-Matrix Interactions  

UK PubMed Central (United Kingdom)

The interactions between biochemical processes and mechanical signaling play important roles during various cellular processes such as wound healing, embryogenesis, metastasis, and cell migration. While...Full Text Available

491

Stress Ratio Effects on Small Fatigue Crack Growth in Ti-6Al ...  

Science.gov (United States)

... in Ti-6Al-4V has been studied quite thoroughly [5-7], much of the work resulting from the Air Force-sponsored High Cycle Fatigue initiative [8]. In ...

2008-11-01

492

Roller Bearing Gear System.  

Science.gov (United States)

The patent application describes an anti-friction worm-wheel assembly wherein the anti-friction elements are rollers carried by the worm element. The rollers sequentially move through grooves in the edge surface of the wheel element to transmit drive forc...

1982-01-01

493

Pore region of TRPV3 ion channel is specifically required for heat-activation  

UK PubMed Central (United Kingdom)

Ion-channels can be activated (gated) by a variety of stimuli including chemicals, voltage, mechanical force or temperature. Whereas molecular mechanisms of ion-channel gating by chemicals and...Full Text Available

2008-09-01

494

Once more: gravity is not an entropic force  

CERN Document Server

We argue that neutron interference experiments and experiments on gravitational bound states of neutron unambiguously disprove entropic origin of gravitation. The criticism expressed in a recent paper [arXiv:1104.4650] concerning our arguments against entropic gravity is shown to be invalid.

2011-01-01

495

Lessons learned in developing community mental health care in Africa  

UK PubMed Central (United Kingdom)

This paper summarizes the findings for the African Region of the WPA Task Force on Steps, Obstacles and Mistakes to Avoid in the Implementation of Community Mental Health Care. We present an overview...Full Text Available

2010-10-01

496

Improvements in or relating to fluid operated devices for moving articles  

International Nuclear Information System (INIS)

The patent relates to fluid operated devices for moving articles. The machine may be used in filling a nuclear fuel canister with fuel pellets where there is a tendency for out of squareness of pellets to produce a jam condition readily cleared by a modest force. (U.K.).

1984-09-27

497

Duplication and Diversification of the Hypoxia-Inducible IGFBP-1 Gene in Zebrafish  

UK PubMed Central (United Kingdom)

BackgroundGene duplication is the primary force of new gene evolution. Deciphering whether a pair of duplicated genes has evolved divergent functions is often challenging. The zebrafish...Full Text Available

498

Control effects of the flow and the aerodynamic force around the downstream cylinder by a spinning upstream cylinder in uniform flow  

Energy Technology Data Exchange (ETDEWEB)

The aerodynamic forces and wake structure of the non-rotating downstream circular cylinder, of which the uniform free stream flow is interfered with another spinning upstream cylinder having the same diameter that is located upstream in a line have been investigated experimentally. When the spin rate of the downstream cylinder defined as the ratio of tangential surface velocity of the spinning cylinder to the free stream velocity increases gradually from zero to 1.4, the change of surface pressure distribution, aerodynamic forces of the non-rotating downstream cylinder were measured in case of several distance ratios of 1.5, 3.0, and 4.5 defined as the ratio of distance between the centers of two cylinders to the diameter. The wake flow patterns behind the cylinder were also investigated in each case. From the present experiments, it has been found that the spin rate significantly influences the aerodynamic forces and ...

1998-03-01

499

Aerodynamic force measurement on a large-scale model in a short duration test facility  

International Nuclear Information System (INIS)

A force measurement technique has been developed for large-scale aerodynamic models with a short test time. The technique is based on direct acceleration measurements, with miniature accelerometers mounted on a test model suspended by wires. Measuring acceleration at two different locations, the technique can eliminate oscillations from natural vibration of the model. The technique was used for drag force measurements on a 3 m long supersonic combustor model in the HIEST free-piston driven shock tunnel. A time resolution of 350 #mu#s is guaranteed during measurements, whose resolution is enough for ms order test time in HIEST. To evaluate measurement reliability and accuracy, measured values were compared with results from a three-dimensional Navier-Stokes numerical simulation. The difference between measured values and numerical simulation values was less than 5%. We conclude that this measurement technique is sufficiently reliable for ...

2005-03-01

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Aerodynamic Force Characteristics of Bluff Bodies.  

Science.gov (United States)

The lift and drag characteristics of a wide range of bluff body shapes were studied using data from sources including wind tunnel testing and flow visualization. For a given orientation of any body, it is found that its drag is strongly influenced by its ...

1985-01-01