WorldWideScience
2

Experimental Differential Light-Scattering Correction to the Circular Dichroism of Bacteriophage T2  

UK PubMed Central (United Kingdom)

Experimental techniques are presented that can be used to assay and correct for differential light scattering effects in circular dichroism spectra of biological macrostructures. The assay is based...Full Text Available

1973-01-01

3

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 ...

2003-09-01

4

Thomson scattering: a powerful diagnostic tool of plasma physics  

International Nuclear Information System (INIS)

Thomson scattering is the process in which a low-energy photon scatters from a free electron. When a laser pulse propagates through a plasma, the spectrum of the scattered light due to the Thomson scattering is proportional to the power spectrum of the electron density fluctuations, i.e., dynamic form factor, from which various plasma parameters can be inferred, such as electron temperature and plasma flow velocity. After years of development. Thomson scattering has now become a powerful diagnostic tool of plasma physics. (authors)

2008-08-01

6

ZnO microsheet modified TiO2 nanoparticle composite films for dye-sensitized solar cells  

British Library Electronic Table of Contents (United Kingdom)

Randomly oriented ZnO microsheets were successfully self-assembled on TiO2 nanoparticle (TN) film to act as the scattering layer via a cathodic electrodeposition process. The light scattering properties of ZnO microsheets were studied by UV-Vis spectrometer in the 400?800 nm wavelength range. It was found that ZnO microsheets exhibited excellent ability to scatter the incident light for ZnO microsheet-TiO2 nanoparticle (ZT) composite films. The results showed that dye-sensitized solar cells (DSSCs) fabricated with ZT composite films showed higher short-circuit density (J sc) and conversion efficiency than TN-based DSSCs, due to the light scattering properties of ZnO microsheets.

2010-01-01

7

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 ...

2005-07-12

8

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 ...

2005-04-17

9

Scattered Light from Close-in Extrasolar Planets: Prospects of Detection with the MOST Satellite  

CERN Document Server

The ultra-precise photometric space satellite MOST (Microvariability and Oscillations of STars) will provide the first opportunity to measure the albedos and scattered light curves from known short-period extrasolar planets. Due to the changing phases of an extrasolar planet as it orbits its parent star, the combined light of the planet-star system will vary on the order of tens of micromagnitudes. The amplitude and shape of the resulting light curve is sensitive to the planet's radius and orbital inclination, as well as the composition and size distribution of the scattering particles in the planet's atmosphere. To predict the capabilities of MOST and other planned space missions, we have constructed a series of models of such light curves, improving upon earlier work by incorporating more realistic details such as: limb darkening of the star, intrinsic ...

2003-01-01

10

Observation of Spontaneous Brillouin Cooling  

CERN Document Server

While radiation-pressure cooling is well known, the Brillouin scattering of light from sound is considered an acousto-optical amplification-only process. It was suggested that cooling could be possible in multi-resonance Brillouin systems when phonons experience lower damping than light. However, this regime was not accessible in traditional Brillouin systems since backscattering enforces high acoustical frequencies associated with high mechanical damping. Recently, forward Brillouin scattering in microcavities has allowed access to low-frequency acoustical modes where mechanical dissipation is lower than optical dissipation, in accordance with the requirements for cooling. Here we experimentally demonstrate cooling via such a forward Brillouin process in a microresonator. We show two regimes of operation for the Brillouin process: acoustical amplification as is traditional, but also for the first time, ...

2011-01-01

11

Contrast Sensitivity and Optical Quality of the Eye after Instillation of Timolol Maleate Gel-Forming Solution and Brinzolamide Ophthalmic Suspension  

British Library Electronic Table of Contents (United Kingdom)

Purpose To investigate the influence of timolol maleate 0.5% gel-forming solution and brinzolamide 1% ophthalmic suspension on contrast sensitivity, ocular higher-order aberration (HOA), and corneal surface light scattering. Design Prospective, comparative study. Participants Forty normal volunteers were enrolled in this study. Methods We evaluated contrast sensitivity, ocular HOA, and corneal light scattering before and 2, 5, 10, and 15 minutes after instillation of antiglaucoma eyedrops. Contrast sensitivity function was assessed with the CSV-1000RN chart (Vector Vision Co., Greenville, OH). Higher-order aberration was measured for a 4-mm pupil using the Hartmann-Shack aberrometer (KR-9000PW; Topcon, Tokyo, Japan). Corneal surface light scattering was quantitatively evaluated by using th...

2010-01-01

13

104 MeV alpha particle and 156 MeV "6Li scattering and the validity of refined folding model approaches for light complex projectile scattering  

International Nuclear Information System (INIS)

The real parts of the optical model potentials for 104 MeV alpha-particle and 156 MeV "6Li ion scattering from "4"0,"4"8Ca are calculated in terms of folding model approaches. The validity of different procedures is tested by comparing the differential cross section predictions with experimental data measured with high angular accuracy. It is found that a refined folding potential accounting for density dependence of an effective nucleon-nucleon interaction is appropriate for alpha particle scattering without any parameter adjustment. However, for "6Li ion scattering renormalization of the depth of the real potentials is necessary. (orig.).

14

Practical measurement of diffusion constants in sintered zirconias by using a light-scattering method  

Energy Technology Data Exchange (ETDEWEB)

A practical method to determine the ionic diffusion coefficient and activation energy by using quasielastic light scattering (QELS) is presented. It is shown that a temperature dependence curve of the QELS intensity at a fixed frequency can be well fitted by Jonscher's formula and that the diffusion parameters can be obtained from this curve fitting. This method is successfully applied not only to crystals with high optical quality, as reported earlier, but also to opaque ceramics, which are more important than the crystals from a practical point of view. The composition dependence of the ionic diffusion coefficient is studied in sintered YbSZ to show the usefulness of this method.

1991-03-01

15

Biopsy examination during the course of radiotherapy. Progress report. [DNA content of tumor cells in biopsy samples determined by microfluorometric or multiangle light-scatter spectrometry  

Science.gov (United States)

Studies begun during the first year of this project on biopsies from spontaneous tumors in dogs and from human patients undergoing radiotherapy treatment were continued. The results indicate that significant fractions of the spontaneous tumors in dogs and cervical carcinomas in patients undergoing radiotherapy have a DNA content higher than normal diploid cells. The higher DNA content in tumor cells permits distinguishing them from normal cells in the biopsy material with the aid of flow microfluorometric (FMF) instrumentation or multiangle light-scatter spectrometry.

1977-12-01

16

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

Energy Technology Data Exchange (ETDEWEB)

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

1980-07-04

17

Low-energy Theorems for Vector Boson Scattering in SU(4)/SU(2) Model of Electroweak Symmetry Breaking  

CERN Document Server

Modifications of low-energy theorems for the scattering of longitudinally polarized W and Z bosons in an alternative model of electroweak symmetry breaking are discussed. The symmetry breaking pattern SU(4)/SU(2) leads to light (compared to 1 TeV) pseudo-Goldstone bosons. Their interactions with electroweak gauge bosons are described by chiral (or effective) lagrangian. Tree-level contribution of the pseudo-Goldstone bosons to the scattering amplitudes are computed. Comparison with the Standard Model is given.

1997-01-01

18

Electron combinational light scattering in disordered Ti_x_-_1Fe_x alloys: theory and experiment  

International Nuclear Information System (INIS)

Theoretical description of Raman scattering in disordered alloys of Ti and Zr with transition metals of groups 5-8 of the Mendeleev Periodic System in critical range of concentrations (CRC) is given. Results of Raman scattering experiment in the system Ti_1_-_xF_x at 0.0005

19

Efficient Cartesian-grid-based modeling of rotationally symmetric bodies  

DEFF Research Database (Denmark)

Axially symmetric waveguides, resonators, and scatterers of arbitrary cross section and anisotropy in the cross section can be modeled rigorously with use of 2-D Cartesian-grid based codes by means of mere redefinition of material permittivity and permeability profiles. The method is illustrated by the frequencydomain simulations of resonant modes in a circular-cylinder cavity with perfectly conducting walls, a shielded uniaxial anisotropic dielectric cylinder, and an open dielectric sphere for which, after proper implementation of the perfectly matched layer boundary conditions, the radiation quality factor is also determined.

2007-01-01

20

First detection of polarized scattered light from an exoplanetary atmosphere  

CERN Document Server

We report the first direct detection of an exoplanet in polarized scattered light. The transiting planet HD189733b is one of the very hot Jupiters with shortest periods and, thus, smallest orbits, which makes them ideal candidates for polarimetric detections. We obtained polarimetric measurements of HD189733 in the $B$ band well distributed over the orbital period and detected two polarization maxima near planetary elongations with the peak amplitude of $\\sim2\\cdot10^{-4}$. Assuming Rayleigh scattering, we estimated the effective size of the scattering atmosphere (Lambert sphere) to be 1.5$\\pm$0.2 $R_{\\rm J}$, which is 30% larger than the radius of the opaque body previously inferred from transits. If the scattering matter fills the planetary Roche lobe, the lower limit of the geometrical albedo can be estimated as 0.14. The phase dependence of polarization indicates that the ...

2007-01-01

21

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

Energy Technology Data Exchange (ETDEWEB)

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

1984-03-01

22

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

International Nuclear Information System (INIS)

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

23

Towards an understanding of the light scalar mesons  

Energy Technology Data Exchange (ETDEWEB)

Although studied for many years the nature of the light scalar mesons remains controversial. Here we shall present a method, applicable for s-wave states located close to a threshold, that allows one to quantify the molecular part of a given state. When applied to the f{sub 0}(980) a dominance of the molecular component is found. In the second part, we show that requirements of field-theoretic consistency and chiral symmetry, when applied to the scattering of light pseudo-scalars, naturally lead to the appearance of dynamical poles in the scalar sector. A program is proposed on how to further investigate experimentally the mixing between these dynamical states and possible genuine quark states. (orig.)

2007-03-15

24

Diffractive deep inelastic scattering in an AdS/CFT inspired model: A phenomenological study  

International Nuclear Information System (INIS)

The analytical treatment of the nonperturbative QCD dynamics is one of the main open questions of the strong interactions. Currently, it is only possible to get some qualitative information about this regime considering other QCD-like theories, as, for example, the N=4 super Yang-Mills theory, where one can perform calculations in the nonperturbative limit of large 't Hooft coupling using the anti-de Sitter space/conformal field theory (AdS/CFT). Recently, the high energy scattering amplitude was calculated in the AdS/CFT approach, applied to deep-inelastic scattering and confronted with the F_2 HERA data. In this work we extend the nonperturbative AdS/CFT inspired model for diffractive processes and compare its predictions with a perturbative approach based on the Balitsky-Kovchegov equation. We demonstrate that the AdS/CFT inspired model is not able to describe the current F_2"D"("3") HERA data and ...

2010-05-01

25

Time-dependent wavepacket calculations of molecular scattering from surfaces  

International Nuclear Information System (INIS)

An outline is given of time-dependent wavepacket methods as applied to calculations of molecular collisions with solid surfaces. The methods reviewed include numerical integration algorithms for the time-dependent Schroedinger equation, semiclassical wavepacket treatments, and approximations that treat some of the degrees-of-freedom quantum-mechanically and others classically. The computational and numerical characteristics of these methods are discussed, with emphasis on their particular advantages and relevance in the context of certain molecule/surface scattering problems. For the semiclassical and mixed quantal-classical treatments, the approximation errors and their physical origins are discussed. For the quantum wavepacket techniques a numerical error analysis is presented. The computational efficiency of the various algorithms is considered and examined in the context of several applications. The main focus is on diffractive scattering ...

1986-01-01

26

Synthetic aperture radar image of agricultural fields with surface drainage network: simulation and spatial information retreival  

Science.gov (United States)

We develop a 3-D model to simulate the synthetic aperture radar (SAR) image formation process of an undulated vegetation canopy such as corn grown in fields with large periodic drainage reliefs. We explain how the simulated SAR image of undulated vegetation medium is obtained by the convolution of a 2-D slice of the 3-D simulated SAR system point spread function [(PSF), emulating the SAR beam modeled by a cosine modulated Gaussian], with the 2-D projection of the observed undulated vegetation canopy (modeled with scatterers randomly distributed in 3-D undulated space) followed by the extraction of each look envelope, the summation of looks, and sampling in azimuthal and range directions. Our model is useful to study the parameters involved in the formation and the analysis of SAR images of undulated vegetation medium. Validation of simulations made with actual SAR images shows that ...

2001-10-01

27

Cross sections for electron scattering by atomic potassium  

International Nuclear Information System (INIS)

Electron elastic and collisional excitation cross sections from the ground state of potassium are calculated using the noniterative integral-equation method of Henry, Rountree, and Smith [Comput. Phys. Commun. 23, 233 (1981)] in the electron energy range 4#<=#E#<=#200 eV. Configuration-interaction target wave functions that take account of correlation and polarization effects are used to represent the ground state and the six lowest excited states 4p "2P degree, 5s "2S, 3d "2D, 5p "2P degree, 4d "2D, and 6s "2S. Elastic and discrete excitation cross sections are obtained in a seven-state close-coupling (7CC) approximation. The 7CC elastic and excitation cross sections are compared and contrasted. Near threshold the elastic cross section dominates the resonance, 4s "2S#->#4p "2P degree, and the sum of the other remaining excitation cross sections. Comparison of our total cross sections with some ...

28

FG Sge at the stage of dust shell ejection  

British Library Electronic Table of Contents (United Kingdom)

New photometric observations of the variable star FG Sge, a rapidly evolving planetary nebula nucleus, were performed in 2003?2008. On 230 nights, we obtained 86 UBV and 155 BV RI (or R c , I c ) magnitude estimates. The maximum amplitude of the V-band light variations was >8 m . Six deep minima and four high maxima were observed. Analysis of the light curve has shown that the pulsation period of the star remained constant since 1991 and was P = 115 days. We have studied the wavelength dependence of the extinction at various phases of the light curve. The blueing of the B-V color at deep minima is interpreted as the result of light scattering in the circumstellar dust shell of the star formed by preceding dust ejections since 1992. Our spectroscopic observations performed on nine nights in...

2009-01-01

29

Scattering and Recombination of Two Triplet Excitons in polymer light-emitting diodes  

CERN Document Server

The scattering and recombination processes between two triplet excitons in conjugated polymers are investigated by using a nonadiabatic evolution method, based on an extended Su-Schrieffer-Heeger model including interchain interactions. Due to the interchain coupling, the electron and/or hole in the two triplet excitons can exchange. The results show that the recombination induces the formation of singlet excitons, excited polarons and biexcitons. Moreover, we also find the yields of these products, which can contribute to the emission, increase with the interchain coupling strength, in good agreement with results from experiments.

2010-01-01

30

New materials for SRS lasers  

International Nuclear Information System (INIS)

The problem of search for new materials for spectrally positioned laser sources, which is central for modern photonics, is discussed. The use of the stimulated Raman scattering effect in crystals offers a highly efficient way to the design of such sources. The recent results of investigations into this effect for a large number of various types of crystalline materials are presented. The most promising compounds, as regards the realisation of different laser operation modes, are considered, including calcium, strontium, barium and lead molybdates and tungstates. Several examples of functioning efficient lasers based on novel materials exhibiting the stimulated Raman light scattering effect are given.

2006-10-31

31

Determining nuclear morphology using an improved angle-resolved low coherence interferometry system  

Science.gov (United States)

We outline the process for determining the morphology of subsurface epithelial cell nuclei using depth-resolved light scattering measurements. The measurements are accomplished using a second generation angle-resolved low coherence interferometry system. The new system greatly improves data acquisition and analysis times compared to the initial prototype system. The calibration of the new system is demonstrated in scattering studies to determine the size distribution of polystyrene microspheres in a turbid sample. The process for determining the size of cell nuclei is discussed by analyzing measurements of basal cells in a sub-surface layer of intact, unstained epithelial tissue.

2003-12-01

32

Study of protein-protein interactions in under saturated and supersaturated lysozyme solutions in heavy water as a function of temperature; Etude des interactions proteine-proteine en solutions sous-saturees et sursaturees de lysozyme dans l`eau lourde en fonction de la temperature  

Energy Technology Data Exchange (ETDEWEB)

We have studied freshly prepared lysozyme solutions in heavy water for two NaCl concentrations as a function of temperature. Lysozyme solubilities in this solvent are determined by static light scattering. By small angle neutron scattering, we evidence that interactions between lysozyme molecules are characterized by a second virial coefficient A{sub 2} whether the solution is under-saturated or supersaturated. From the variation of A{sub 2} as a function of temperature we have evaluated the enthalpy corresponding to the interaction between lysozyme molecules. We show that the interactions between protein molecules are higher in heavy water than in light water. (authors). 13 refs., 3 figs.

1996-04-01

33

Primary results of measuring plasma electron temperature with YAG laser thomson scattering system on the HL-2A tokamak  

International Nuclear Information System (INIS)

This article describes the laser Thomson scattering principle and the developed system on HL-2A device. The high power Q-switch Nd:YAG laser, with a wavelength of 1064 nm, can sufficiently satisfy the measurement requirement. The polycromator consisting of avalanche photo-diodes(APD) and narrow band interference filters, can effectively improve the measurement of scattering light. The electron temperature is deduced by error-weighted lookup table method, which improves the data- processing speed or efficiency. Finally, the experiment results of the one-point electron temperature during different discharges of plasma are presented. (authors)

2008-07-01

34

Native Synthetic Imaging of Smoothed Particle Hydrodynamics density fields using gridless Monte Carlo Radiative Transfer  

CERN Document Server

An algorithm for creating synthetic telescope images of Smoothed Particle Hydrodynamics (SPH) density fields is presented, which utilises the adaptive nature of the SPH formalism in full. The imaging process uses Monte Carlo Radiative Transfer (MCRT) methods to model the scattering and absorption of photon packets in the density field, which then exit the system and are captured on a pixelated image plane, creating a 2D image (or a 3D datacube, if the photons are also binned by their wavelength). The algorithm is implemented on the density field directly: no gridding of the field is required, allowing the density field to be described to an identical level of accuracy as the simulations that generated it. Some applications of the method to star and planet formation simulations are presented to illustrate the advantages of this new technique, and suggestions as to how this framework could support a Radiative Equilibrium ...

2010-01-01

35

Automated three-dimensional X-ray analysis using a dual-beam FIB  

International Nuclear Information System (INIS)

We present a fully automated method for three-dimensional (3D) elemental analysis demonstrated using a ceramic sample of chemistry (Ca)MgTiO_x. The specimen is serially sectioned by a focused ion beam (FIB) microscope, and energy-dispersive X-ray spectrometry (EDXS) is used for elemental analysis of each cross-section created. A 3D elemental model is reconstructed from the stack of two-dimensional (2D) data. This work concentrates on issues arising from process automation, the large sample volume of approximately 17x17x10 #mu#m"3, and the insulating nature of the specimen. A new routine for post-acquisition data correction of different drift effects is demonstrated. Furthermore, it is shown that EDXS data may be erroneous for specimens containing voids, and that back-scattered electron images have to be used to correct for these errors.

2007-08-01

36

A multi-wavelength scattered light analysis of the dust grain population in the GG Tau circumbinary ring  

Energy Technology Data Exchange (ETDEWEB)

We present the first 3.8 {micro}m image of the dusty ring surrounding the young binary system GG Tau, obtained with the W. M. Keck II 10m telescope's adaptive optics system. THis is the longest wavelength at which the ring has been detected in scattered light so far, allowing a multi-wavelength analysis of the scattering proiperties of the dust grains present in this protoplanetary disk in combination with previous, shorter wavelengths, HST images. We find that the scattering phase function of the dust grains in the disk is only weakly dependent on the wavelength. This is inconsistent with dust models inferred from observations of the interstellar medium or dense molecular clouds. In particular, the strongly forward-throwing scattering phase function observed at 3.8 {micro}m implies a significant increase in the population of large ({approx}> 1 {micro}m) grains, ...

2004-02-04

37

Measurement of gas flow velocities by laser-induced gratings  

Energy Technology Data Exchange (ETDEWEB)

Time resolved light scattering from laser-induced electrostrictive gratings was used for the determination of flow velocities in air at room temperature. By measuring the velocity profile across the width of a slit nozzle we demonstrated the high spatial resolution (about 200 mm) of this novel technique. (author) 3 figs., 1 ref.

1999-08-01

38

Aerosols Equipment in Sweden on Environmental Expert  

Wastenet

... Hale, Markku Kulmala, 373.43 EUR; 225.00 USD; 276.00 GBP... Light Scattering Media Optics Alexander A. Kokhanovsky 159.00 USD; 123.00 EUR; 103.50 GBP... More Journals » MAGAZINES & JOURNALS Water Policy - Official Journal of the World... Water Policy publishes reviews, research papers... ...

39

(Research in theoretical physics): Annual performance report, (1986)  

Energy Technology Data Exchange (ETDEWEB)

Results are reported in the areas of: chiral fermions and anomalies, superstring finiteness, superstring phenomenology, spin splittings in heavy quarkonia, low-energy limits of superstring, a supersymmetric electroweak model with a light squark, scalar quark bound states, fermionic tachyons and Poincare representations, relativistic dynamics of spin-one particles and deuteron-nucleus scattering, interactions involving higher spin massless particles, and classical action at a distance theories which contain a cutoff. (LEW)

1986-01-01

40

Monte Carlo simulations incorporating Mie calculations of light transport in tissue phantoms: Examination of photon sampling volumes for endoscopically compatible fiber optic probes  

Energy Technology Data Exchange (ETDEWEB)

Details of the interaction of photons with tissue phantoms are elucidated using Monte Carlo simulations. In particular, photon sampling volumes and photon pathlengths are determined for a variety of scattering and absorption parameters. The Monte Carlo simulations are specifically designed to model light delivery and collection geometries relevant to clinical applications of optical biopsy techniques. The Monte Carlo simulations assume that light is delivered and collected by two, nearly-adjacent optical fibers and take into account the numerical aperture of the fibers as well as reflectance and refraction at interfaces between different media. To determine the validity of the Monte Carlo simulations for modeling the interactions between the photons and the tissue phantom in these geometries, the simulations were compared to measurements of aqueous suspensions of polystyrene microspheres in the wavelength range 450-750 nm.

1996-04-01

41

Isobaric analog resonances in "8"9Y  

International Nuclear Information System (INIS)

Three resonances at the proton energies 7.0, 7.08, and 7.53 MeV on the target "8"8Sr were chosen to investigate the possibility of determining the amplitudes of the weak coupling experimentally. The corresponding "8"9Sr levels under investigation were 1.93 MeV ("5/_2"+), 2.00 MeV ("3/_2"+), and 2.46 MeV ("3/_2"+). Angular distributions were measured on resonance at 7.0, 7.08, and 7.53 MeV from proton inelastic scattering to the 1.84 MeV (2"+) state of "8"8Sr for differential cross section, analyzing power, spin-flip probability, and spin-flip asymmetry. A polarized beam of protons was used to obtain the analyzing power. The spin-flip probability was obtained from the coincidence of the prompt gamma rays from the (p,p'#gamma#) reaction with the scattered protons. With the polarized beam, the gamma coincidence technique was further used to obtain a spin-flip asymmetry measurement. From these measurements, the polarization was calculated, and the ...

42

Optical Feshbach Resonances in Alkaline Earth Atoms  

Science.gov (United States)

Recent proposals have shown that a quantum degenerate gas of alkaline earth atoms can be used for a number of novel quantum computing and quantum simulation experiments. Strontium is a good candidate for such experiments because it can be controlled with high precision, as demonstrated in recent atomic clock experiments. Unfortunately, the small scattering length of strontium is not amenable to evaporative cooling techniques that are used to reach quantum degeneracy. Furthermore, increasing the scattering length of alkaline earths with a magnetic Feshbach resonance is not possible due to their spinless electronic ground state configuration. However, recent theoretical and experimental work suggests the possibility of changing scattering lengths in alkaline earths with laser light. Using this optical Feshbach resonance near strontium's narrow ^1S0->^3P1 intercombination transition might allow its ...

2009-10-01

43

Effective multiplication factor measurement by feynman-{alpha} method. 3  

Energy Technology Data Exchange (ETDEWEB)

The sub-criticality monitoring system has been developed for criticality safety control in nuclear fuel handling plants. In the past experiments performed with the Deuterium Critical Assembly (DCA), it was confirmed that the detection of sub-criticality was possible to k{sub eff} = 0.3. To investigate the applicability of the method to more generalized system, experiments were performed in the light-water-moderated system of the modified DCA core. From these experiments, it was confirmed that the prompt decay constant ({alpha}), which was a index of the sub-criticality, was detected between k{sub eff} = 0.623 and k{sub eff} = 0.870 and the difference of 0.05 - 0.1{Delta}k could be distinguished. The {alpha} values were numerically calculated with 2D transport code TWODANT and monte carlo code KENO V.a, and the results were compared with the measured values. The differences between calculated and measured values were proved ...

1998-06-01

44

Sterically stabilized water based magnetic fluids: Synthesis, structure and properties  

Energy Technology Data Exchange (ETDEWEB)

Magnetic fluids (MFs), prepared by chemical co-precipitation followed by double layer steric and electrostatic (combined) stabilization of magnetite nanoparticles dispersed in water, are presented. Several combinations of surfactants with different chain lengths (lauric acid (LA), myristic acid (MA), oleic acid (OA) and dodecyl-benzene-sulphonic acid (DBS)) were used, such as LA+LA, MA+MA, LA+DBS, MA+DBS, OA+DBS, OA+OA and DBS+DBS. Static light scattering, transmission electron microscopy, small angle neutron scattering, magnetic and magneto-rheological measurements revealed that MFs with MA+MA or LA+LA biocompatible double layer covered magnetite nanoparticles are the most stable colloidal systems among the investigated samples, and thus suitable for biomedical applications.

2007-04-15

45

Relativistic D-brane scattering is extremely inelastic  

Energy Technology Data Exchange (ETDEWEB)

We study the effects of quantum production of open strings on the relativistic scattering of D-branes. We find strong corrections to the brane trajectory from copious production of highly-excited open strings, whose typical oscillator level is proportional to the square of the rapidity. In the corrected trajectory, the branes rapidly coincide and remain trapped in a configuration with enhanced symmetry. This is a purely stringy effect which makes relativistic brane collisions exceptionally inelastic. We trace this effect to velocity-dependent corrections to the open string mass, which render open strings between relativistic D-branes surprisingly light. We observe that pair-creation of open strings could play an important role in cosmological scenarios in which branes approach each other at very high speeds. (author)

2005-02-01

46

Phase-Separation Kinetics and Mechanism in a Methylcellulose/Salt Aqueous Solution Studied by Time-Resolved Small-Angle Light Scattering (SALS)  

British Library Electronic Table of Contents (United Kingdom)

Abstract Phase-separation dynamics are investigated by SALS in aqueous MC solutions in the presence of 5% NaCl, promoted by a quench temperature. The observed scattering peak indicates that the phase separation occurs by the SD mechanism, leading to a bicontinuous structure. A semilog plot of I(q) against time in the early stage of SD gives a straight line, but the position of qmax varies; also, a Cahn-Hilliard plot indicates that diffusive processes dominate and the data can be described by linear CHC theory. Dapp shows a kinetic dependency on the quench temperature. The spinodal temperature of the sample is 41-C. In the late stages, S(q,t) collapses into a universally time-independent curve.

2011-01-01

47

Covariances for neutron cross sections calculated using a regional model based on local-model fits to experimental data  

Energy Technology Data Exchange (ETDEWEB)

We suggest a procedure for estimating uncertainties in neutron cross sections calculated with a nuclear model descriptive of a specific mass region. It applies standard error propagation techniques, using a model-parameter covariance matrix. Generally, available codes do not generate covariance information in conjunction with their fitting algorithms. Therefore, we resort to estimating a relative covariance matrix a posteriori from a statistical examination of the scatter of elemental parameter values about the regional representation. We numerically demonstrate our method by considering an optical-statistical model analysis of a body of total and elastic scattering data for the light fission-fragment mass region. In this example, strong uncertainty correlations emerge and they conspire to reduce estimated errors to some 50% of those obtained from a naive uncorrelated summation in quadrature. 37 references.

1983-11-01

48

Angular momentum dependence in 22 MeV alpha-particle elastic scattering by light nuclei  

International Nuclear Information System (INIS)

Elastic scattering of 22 MeV alpha particles by "2"3Na, sup(24-25-26)Mg, "2"7Al and "2"8Si has been measured between 24"0 and 174"0 lab. Partial angular distributions, from 120"0 to 174"0, were also measured at incident energies of 18.4 and 20.7 MeV for "2"4Mg, and 18.9 and 20.5 MeV for "2"8Si. The most striking feature of the data is the large angle behaviour: spin-zero nuclei display more pronounced backward oscillations and the cross section rises more steeply towards 180"0 for 4n nuclei than for the others. (Z.M.).

49

Photodynamic efficacy of hypericin targeted by two delivery techniques to hepatocellular carcinoma cells  

British Library Electronic Table of Contents (United Kingdom)

The photocytotoxic effect of hypericin (Hyp) targeted by two different delivery techniques, namely, liposomes and anti-hepatocyte specific antigen (anti-HSA) was investigated. Optical absorption and steady-state fluorescence were used to analyze the conjugation of Hyp with anti-HSA model and to evaluate the encapsulation capacity and drug release in a liposome model. Particle size and thermal analysis of the prepared liposomes were performed using laser-light scattering and differential scanning calorimetry (DSC), respectively. Viability study of HepG2 cells exposed to Hyp in the two delivery systems, in the dark and following visible light irradiation, was performed in comparison to free Hyp. The intracellular uptake and localization of Hyp in HepG2 cells were analyzed by means of spectro...

2010-01-01

50

Non-Detection of Polarized, Scattered Light from the HD 189733b Hot Jupiter  

CERN Document Server

Using the POLISH instrument, I am unable to reproduce the large-amplitude polarimetric observations of Berdyugina et al. (2008) to the >99.99% confidence level. I observe no significant polarimetric variability in the HD 189733 system, and the upper limit to variability from the exoplanet is Delta_P < 7.9 x 10^(-5) with 99% confidence in the 400 nm to 675 nm wavelength range. Berdyugina et al. (2008) report polarized, scattered light from the atmosphere of the HD 189733b hot Jupiter with an amplitude of two parts in 10^4. Such a large amplitude is over an order of magnitude larger than expected given a geometric albedo similar to other hot Jupiters. However, my non-detection of polarimetric variability phase-locked to the orbital period of the exoplanet, and the lack of any significant variability, shows that the polarimetric modulation reported by Berdyugina et al. (2008) cannot be due to the exoplanet.

2009-01-01

51

Planetpol polarimetry of the exoplanet systems 55 Cnc and tau Boo  

CERN Document Server

We present very sensitive polarimetry of 55 Cnc and tau Boo in an attempt to detect the partially polarised reflected light from the planets orbiting these two stars. 55 Cnc is orbited by a hot Neptune planet (55 Cnc e) at 0.038 AU, a hot Jupiter planet (55 Cnc b) at 0.11 AU, and at least 3 more distant planets. The fractional polarisation of this star is very stable, with a standard deviation in the nightly averaged Stokes Q/I and U/I parameters of 2.2x10^{-6}. We derive upper limits on the geometric albedo, A_G and planetary radius using Monte Carlo multiple scattering simulations of a simple model atmosphere. We assume Rayleigh-like scattering and polarisation behaviour (scaled by the maximum polarisation, p_m at 90 degrees) and pressure insensitive extinction. Atmospheres in which multiple scattering plays only a small role have an almost linear relation between polarisation and A_G. In this case, ...

2008-01-01

52

Subsurface imaging using the spectral polarization difference technique and NIR illumination  

Energy Technology Data Exchange (ETDEWEB)

A subsurface imaging system is utilized to test the ability of the spectral polarization difference imaging technique for deep subsurface imaging in tissues. The illumination of the system is derived from compact class III lasers in the red and NIR spectral region and, alternatively, from a white light source and selection of the appropriate illumination wavelength using band-pass optical filters. The experimental results demonstrate detection and imaging of a high-scattering object located up to 1.5 cm underneath the surface of a host chicken tissue.

1999-01-26

53

Search for an instability on a quenched-liquid interface  

Energy Technology Data Exchange (ETDEWEB)

We searched for signs of an instability on the interface between the two phases of a binary-liquid mixture, isobutyric acid and water, after the mixture was quenched further into the two-phase region. Such an instability would be the liquid-liquid analog of the Mullins-Sekerka instability seen in quenched alloys. Never is any dramatic growth observed, but under conditions of small dimensionless quench depth (theta<1.5 x 10/sup -3/), the intensity of light scattered from the interface grows for small values of the momentum transfer k.

1987-04-15

54

Prospects for lithium imaging using annular bright field scanning transmission electron microscopy: A theoretical study  

British Library Electronic Table of Contents (United Kingdom)

There is strong interest in lithium imaging, particularly because of its significance in battery materials. However, light atoms only scatter electrons weakly and atomic resolution direct imaging of lithium has proven difficult. This paper explores theoretically the conditions under which lithium columns can be expected to be directly visible using annular bright field scanning transmission electron microscopy. A detailed discussion is given of the controllable parameters and the conditions most favourable for lithium imaging.

2011-01-01

55

Polarization of high-energy electrons traversing a laser beam  

Energy Technology Data Exchange (ETDEWEB)

When polarized electrons traverse a region where the laser light is focused their polarization varies even if their energy and direction of motion are not changed. This effect is due to interference of the incoming electron wave and an electron wave scattered at zero angle. Equations are obtained which determine the variation of the electron-density matrix, and their solutions are given. The change in the electron polarization depends not only on the Compton cross section but on the real part of the forward Compton amplitude as well. It should be taken into account, for example, in simulations of the e{yields}{gamma} conversion for future {gamma}{gamma} colliders. (orig.). 16 refs.

1998-02-21

56

Polarization of high-energy electrons traversing a laser beam  

International Nuclear Information System (INIS)

When polarized electrons traverse a region where the laser light is focused their polarization varies even if their energy and direction of motion are not changed. This effect is due to interference of the incoming electron wave and an electron wave scattered at zero angle. Equations are obtained which determine the variation of the electron-density matrix, and their solutions are given. The change in the electron polarization depends not only on the Compton cross section but on the real part of the forward Compton amplitude as well. It should be taken into account, for example, in simulations of the e#->##gamma# conversion for future #gamma##gamma# colliders. (orig.).

57

New focal plane detector system for the broad range spectrometer  

Energy Technology Data Exchange (ETDEWEB)

A focal plane detector system consisting of a vertical drift chamber, parallel plate avalanche counters, and an ionization chamber with segmented anodes has been installed in the Broad Range Spectrometer at the Holifield Facility at Oak Ridge. The system, which has been designed for use with light-heavy ions with energies ranging from 10 to 25 MeV/amu, has a position resolution of approx. 0.1 mm, a scattering angle resolution of approx. 3 mrad, and a mass resolution of approx. 1/60.

1984-01-01

58

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 ...

2010-03-24

59

Optimizing an analytical dose calculation algorithm for fast 2D calculations  

International Nuclear Information System (INIS)

Previously, an analytical dose calculation algorithm for MLC-based radiotherapy was developed and commissioned, which includes a detailed model of various MLC effects as a unique feature [1]. The algorithm was originally developed as an independent verification of the treatment planning system's dose calculation and it explicitly modeled spatial and depth dependent MLC effects such as interleaf transmission, the tongue-and-groove effect, rounded leaf ends, MLC scatter, beam hardening, and gradual MLC transmission fall-off with increasing off-axis distance. Originally the algorithm was implemented in Mathematica trademark (Wolfram). To speed up the calculation time and to be able to calculate high resolution 2D dose distributions within a reasonable time frame (<2 s) the algorithm needs to be optimized and to be embedded in a user friendly environment. To achieve this goal, the dose calculation model is implemented in ...

60

Seismic migration and absorbing boundaries with a one-way wave system for heterogeneous media  

Energy Technology Data Exchange (ETDEWEB)

A first-order one-way wave system has been created based on characteristic analysis of the acoustic wave system and optimization of the dispersion relation. The authors demonstrate that this system is equivalent to a third-order scalar partial-differential equation which, for a homogeneous medium, reduces to a form similar to the 45{degree} paraxial wave equation. This system describes accurately waves propagating in a 2D heterogeneous medium at angles up to 75{degree}. The one-way wave system representing downgoing waves is used for a modified reverse time migration method. As a wavefield extrapolator in migration, the downgoing wave system propagates the reflection events backwards to their reflectors without scattering at the discontinuities in the velocity model. Hence, images with amplitudes proportional to reflectivity can be obtained from this migration technique. They present examples of the application of the new ...

1996-07-01

63

Measurement of the mean energy of the off-axis incident electron without the beam guide. Using a scintillating fiber beam-energy monitor for electron beam therapy  

Energy Technology Data Exchange (ETDEWEB)

In the case of total skin electron therapy without the beam guide, the electron beam is scattered just outside the gantry exit, dose uniformity in the field is broken, and dose is spread outside the light field. The aims of this study were to measure the mean energy of the off-axis incident electron beam without the beam guide and to establish a reference for the clinical situation. For the measurement, a 4 MeV electron beam was selected among several energies from the linear accelerator. A scintillating fiber beam energy monitor measured the mean energy of the incident electron beam. This energy monitor is a small, light-weight piece of equipment composed of a wedge absorber, scintillation fiber, and photodiode. We found the relationship between electron energy and the indicated value of the energy monitor by means of the estimation of correction factors for five different kinds of electron energy. The preferable linear ...

2002-06-01

64

3-Dimensional Mapping of Corneal Topography and Thickness  

CERN Document Server

Optical sections of the cornea are obtained by illumination with a collimated beam expanded in a fan shape by a small rotary cylindrical lens. The light diffused from the cornea is observed by two cameras and processed in order to yield the surfaces' profiles. The optical system used to project a thin rotating line on the cornea consists of a white light source provided with optical fiber bundle output which is first conditioned by a set of lenses so that it would produce a spot on the cornea. A small cylinder lens is used to expand the beam in one direction so that a thin line illuminates the cornea, rather than a spot. The cylinder lens is provided with motor driven rotation about an axis normal to its own in order to rotate the line on the cornea such that the projected line scans the whole cornea; the illuminator is completed with a slit aperture. The cornea is not perfectly transparent, scattering some of the ...

2003-01-01

65

Sunyaev-Zeldovich profiles for clusters and groups of galaxies  

CERN Document Server

The Sunyaev-Zeldovich (SZ) effect gives a measure of the thermal energy and electron pressure in groups and clusters of galaxies. In the near future SZ surveys will map hundreds of systems, shedding light on the pressure distribution in the systems. The thermal energy is related to the total mass of a system of galaxies, but it is only a projection that is observed through the SZ effect. A model for the 3D distribution of pressure is needed to link the SZ signal to the total mass of the system. In this work we construct an empirical model for the 2D and 3D SZ profile, and compare it to a set of realistic high resolution SPH simulations of galaxy clusters and groups, and to a stacked SZ profile for massive clusters derived from WMAP data. Furthermore, we combine observed temperature profiles with dark matter potentials to yield an additional constraint, under the assumption of hydrostatic equilibrium. We find a very tight ...

2007-01-01

66

Resolution enhancement by subtraction of confocal signals taken at different pinhole sizes.  

Science.gov (United States)

Subtractive imaging in confocal fluorescence light microscopy is based on the subtraction of a suitably weighted widefield image from a confocal image. An approximation to a widefield image can be obtained by detection with an opened confocal pinhole. The subtraction of images enhances the resolution in-plane as well as along the optic axis. Due to the linearity of the approach, the effect of subtractive imaging in Fourier-space corresponds to a reduction of low spatial frequency contributions leading to a relative enhancement of the high frequencies. Along the direction of the optic axis this also results in an improved sectioning. Image processing can achieve a similar effect. However, a 3D volume dataset must be acquired and processed, yielding a result essentially identical to subtractive imaging but superior in signal-to-noise ratio. The latter can be increased further with the technique of weighted averaging in Fourier-space. A comparison of ...

2003-01-01

67

Neutron beam experiments using nuclear research reactors: honoring the retirement of professor Bernard W. Wehring -I. 6. Neutronics Analyses for Beamline Upgrades to the High Flux Isotope Reactor  

International Nuclear Information System (INIS)

The High Flux Isotope Reactor (HFIR) located at Oak Ridge National Laboratory is one of the world's most powerful research reactors. In 1996, one year after the demise of the Advanced Neutron Source Project, the U.S. Department of Energy embarked on an aggressive program to upgrade the neutron scattering facilities at the HFIR. These upgrades, which are now in progress, include the installation of larger beam tubes, a high-performance hydrogen cold source, and additional neutron guides and neutron scattering instruments. An extensive analysis effort was performed over the past 4 yr to support the design of the modified beamlines and new user facilities and to assess the impact of the upgrades on the integrity of the existing reactor system. The results of three of these analyses are summarized here. Specifically, results are presented for analyses related to the design of the new cold neutron source (CNS), the assessment of beam tube changes on ...

2001-06-17

70

Water structure as a function of temperature from X-ray scatteringexperiments and ab initio molecular dynamics  

Energy Technology Data Exchange (ETDEWEB)

We present high-quality X-ray scattering experiments on pure water taken over a temperature range of 2 to 77 C using a synchrotron beam line at the advanced light source (ALS) at Lawrence Berkeley National Laboratory. The ALS X-ray scattering intensities are qualitatively different in trend of maximum intensity over this temperature range compared to older X-ray experiments. While the common procedure is to report both the intensity curve and radial distribution function(s), the proper extraction of the real-space pair correlation functions from the experimental scattering is very difficult due to uncertainty introduced in the experimental corrections, the proper weighting of OO, OH, and HH contributions, and numerical problems of Fourier transforming truncated data in Q-space. Instead, we consider the direct calculation of X-ray scattering spectra using electron densities derived ...

2003-03-01

71

Neutrino emission in neutron matter from magnetic moment interactions  

CERN Document Server

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

2004-01-01

72

Fusion of Nonionic Vesicles  

DEFF Research Database (Denmark)

We present an experimental study of vesicle fusion using light and neutron scattering to monitor fusion events. Vesicles are reproducibly formed with an extrusion procedure using an single amphiphile triethylene glycol mono-n-decyl ether in water. They show long-term stability for temperatures around 20 C, but at temperatures above 26 C we observe an increase in the scattered intensity due to fusion. The system is unusually well suited for the study of basic mechanisms of vesicle fusion. The vesicles are flexible with a bending rigidity of only a few k(H)T. The monolayer spontaneous curvature, Ho, depends strongly on temperature in a known way and is thus tunable. For temperatures where H-0 > 0 vesicles tyre long-term stable, while in the range H-0 < 0 the fusion rate increases the more negative the Spontaneous curvature Through a quantitative;analysis of the fusion rate we arrive tit a barrier to fusion changing from ...

2010-01-01

73

Demonstration and Optimization of a Drive Laser for an X-Band Photoinjector  

Energy Technology Data Exchange (ETDEWEB)

Recently, a drive laser for an S-band (2.86 GHz) rf photoinjector, designed to provide a pulse that has a flat temporal and spatial profile, has been built, commissioned, and put into service as part of the LLNL Compton-scattering monoenergetic {gamma}-ray source program. This laser is based on an all-fiber oscillator and front-end amplification system, and provides both the laser light to generate the electrons as well as the rf signal that is amplified to accelerate them. Now, a new 11.424 GHz photoinjector is being developed, which has required a revised design for the laser system. The higher frequency has placed more stringent requirements on the synchronization stability, delivered pulse length, and pulse rise times to maintain the desired emittance. Presented here are the overall design and measured performance of the current system and a discussion of what changes are being made to address observed shortcomings and more demanding ...

2009-04-17

74

DNA cleavage on photoexposure at the d-d band in ternary copper(II) complexes using red-light laser.  

Science.gov (United States)

Ternary copper(II) complexes [Cu(L1)B](ClO4) (1, 2) and [Cu(L2)B](ClO4) (3, 4), where HL1 and HL2 are tridentate NSO- and ONO-donor Schiff bases and B is a heterocyclic base, viz. dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 1 and 3) or dipyrido[3,2-a:2',3'-c]phenazine (dppz, 2 and 4), were prepared and their DNA binding and photoinduced DNA cleavage activity studied. Complex 1, structurally characterized by single-crystal X-ray crystallography, shows an axially elongated square-pyramidal (4 + 1) coordination geometry in which the monoanionic L1 binds at the equatorial plane. The NN-donor dpq ligand exhibits an axial-equatorial binding mode. The complexes display good binding propensity to calf thymus DNA, giving a relative order 2 (NSO-dppz) > 4 (ONO-dppz) > 1 (NSO-dpq) > 3 (ONO-dpq). They cleave supercoiled pUC19 DNA to its nicked circular form when treated with 3-mercaptopropionic acid (MPA) by formation of hydroxyl radicals as the ...

2006-12-25

75

NASA's Real World: The Light Plants Need - NASA  

Science.gov (United States)

light-emitting diode A light-emitting diode, or LED, is a semi-conductor light source that emits visible light or invisible infrared radiation. Semi-conductors ...

76

Use of primary electron counting for detection of ultrasoft x-rays with a low-pressure multistep gaseous detector  

International Nuclear Information System (INIS)

The use of primary electron counting techniques as an alternative to the more usual parallel plate avalanche chamber that has been employed in soft x-ray scattering experiments is being investigated at the National Synchrotron Light Source. The theoretical aspects of primary electron counting and motivation behind building a primary electron counting detector are described, as well as characteristics and future improvements of the device constructed at the NSLS. The detector consists of a low electric field drift region and a low pressure multistep avalanche region which can be operated with two or three stages of electron multiplication. The device has worked well in extensive tests as a simple parallel plate avalanche chamber, providing energy resolutions of 58% and 43% at 277 and 500 eV, respectively. Operated as a primary electron counter, preliminary results show an energy resolution of 38% at 500 eV.

77

Tropospheric chemistry of natural hydrocarbons, aldehydes, and peroxy radicals: Their connections to sulfuric acid production and climate effects  

International Nuclear Information System (INIS)

Recent work has shown that natural hydrocarbon emissions can significantly affect the levels of urban and regional tropospheric ozone. We report on the reactivities of these biogenic trace gases, particularly isoprene, focusing on their importance in the production of aldehydes and peroxy radicals, leading to increased levels of hydrogen over regional forests. Hydrogen peroxide can lead to the wet oxidation of sulfur dioxide to acidic sulfate in aerosols, fogs, and clouds. In turn, acidic sulfate can act to as a light scattering aerosol and a source of cloud condensation nuclei (CCN), potentially leading to global cooling. Aerosol sulfate and other dissolved organic and inorganic compounds can also play important roles as a greenhouse species in the lower troposphere.

1993-08-08

78

Surface analysis by Fourier-transform infrared (FTIR) spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

A diffuse-reflectance capability for the Fourier transform infrared spectrometer at the Y-12 Plant Laboratory has been implemented. A sample cell with a 25 to 400/sup 0/C temperature-controlled sample stage and an ultrahigh-vacuum-to-atmospheric pressure gas-handling capability has been developed. Absorbance of light from the spectrometer beam, resulting from the beam being scattered from a powder sample, can be measured. This capability of detecting molecular species on and in powders is to be used to study chemisorption on actinide and rare-earth metals, alloys, and compounds. Cell design is described along with experiments demonstrating its performance in detecting moisture absorption on uranium oxide, moisture and carbon dioxide absorption on the lithium hydride/hydroxide system, and carbon dioxide absorption on potassium borohydride. 13 figures.

1981-08-12

79

Real time study of the crystallization of aluminium-base icosahedral phases by neutron powder diffraction  

International Nuclear Information System (INIS)

The thermal transformation of Al-base icosahedral phases was studied in-situ by real time neutron powder diffraction. Different compositions have been selected in order to vary the initial phase morphology and change the neutron scattering contrast between species. Alloys with low silicon and large aluminium contents produce first the orthorhombic O-Al_6Mn modification. In alloys with larger silicon content, the #alpha#-AlMnSi cubic phase appears soon after the beginning of the transformation but is still preceeded by O-Al_6Mn. Depending on compositions, the crystallization of the icosahedral phase is controlled either by the diffusion of Al through its interface with the residual fcc aluminium or that of Si within the bulk. The results are discussed in the light of current structural models. (author) 40 refs., 14 figs., 3 tabs.

1987-01-01

80

Preparation of nanocomposite dispersions based on cellulose whiskers and acrylic copolymer by miniemulsion polymerization: Effect of the silane content  

British Library Electronic Table of Contents (United Kingdom)

Abstract A one step method was used to prepare stable aqueous nanocomposite dispersions based on cellulose whiskers extracted from the rachis of the date palm tree and a poly(styrene co 2 ethyl hexylacrylate) copolymer via miniemulsion polymerization. A reactive silane, i.e., methacryloxypropyl triethoxysilane was added to stabilize the dispersion and favor the anchoring of the whiskers on polymer particles. Dynamic light scattering was used to study the effect of the silane and whiskers contents on the average particle size of the polymer. Nanocomposites materials were prepared from these dispersions using a casting/evaporation method. The effect of the silane and whiskers contents on the thermal and mechanical properties were studied using differential scanning calorimetry and dynamic me...

2011-01-01

81

Observation of dust stream formation produced by low current, high voltage cathode spots  

International Nuclear Information System (INIS)

Macroparticle acceleration driven by low current, high voltage cathode spots has been investigated for potential applications ranging from micrometeoroid simulation to nanoparticle deposition/implantation. Acceleration by this process was observed to occur when nanometer and micrometer-sized particles were exposed to a high voltage pulse in the presence of a plasma discharge. The applied negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provide the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. Cathode spot behavior was also documented. The particle impact craters observed at the surface of downstream witness badges were documented using scanning electron microscopy and light microscopy. The observed impacts suggest the presence of energetic macroparticles formed during this process.

2004-04-01

82

Numerical modeling of a Global Navigation Satellite System in a general relativistic framework  

CERN Document Server

In this article we model a Global Navigation Satellite System (GNSS) in a Schwarzschild space-time, as a first approximation of the relativistic geometry around the Earth. The closed time-like and scattering light-like geodesics are obtained analytically, describing respectively trajectories of satellites and electromagnetic signals. We implement an algorithm to calculate Schwarzschild coordinates of a GNSS user who receives proper times sent by four satellites, knowing their orbital parameters; the inverse procedure is implemented to check for consistency. The constellation of satellites therefore realizes a geocentric inertial reference system with no \\emph{a priori} realization of a terrestrial reference frame. We show that the calculation is very fast and could be implemented in a real GNSS, as an alternative to usual post-Newtonian corrections. Effects of non-gravitational perturbations on positioning errors are assessed, and methods to ...

2010-01-01

83

Nearly Conformal QCD and AdS/CFT  

Energy Technology Data Exchange (ETDEWEB)

The AdS/CFT correspondence is a powerful tool to study the properties of conformal QCD at strong coupling in terms of a higher dimensional dual gravity theory. The power-law falloff of scattering amplitudes in the non-perturbative regime and calculable hadron spectra follow from holographic models dual to QCD with conformal behavior at short distances and confinement at large distances. String modes and fluctuations about the AdS background are identified with QCD degrees of freedom and orbital excitations at the AdS boundary limit. A description of form factors in space and time-like regions and the behavior of light-front wave functions can also be understood in terms of a dual gravity description in the interior of AdS.

2005-08-08

84

NAME=\\  

Wastenet

... Home Our work Conservation Advice Land management for nightjars Land management for nightjars Nightjars are masters of camouflage The nightjar is now a scarce breeding bird of lowland heathland, forest clearings and clearfells on suitable light soils throughout Britain, north to southern Scotland, and in coppice woodland in south-east England. Nightjars were once much more numerous and widespread than today, but now appear to be recovering.... This offers shelter, camouflage and seclusion from potential predators. Scattered trees are used to sing from and to roost in. In conifer forest clearings, clear-fells and restocks, especially on former heathland, the vegetation structure is like that of heathland, augmented with lying brash, which provides added concealment. Restocked clearings are abandoned as the tree canopy closes over the open ground around seven to ...

85

Low-temperature oxidative degradation of PBX 9501 and its components determined via molecular weight analysis of the Poly[ester urethane] binder  

British Library Electronic Table of Contents (United Kingdom)

The results of following the oxidative degradation of a plastic-bonded explosive (PBX 9501) are reported. Into over 1100 sealed containers were placed samples of PBX 9501 and combinations of its components and aged at relatively low temperatures to induce oxidative degradation of the samples. One of the components of the explosive is a poly(ester urethane) polymer and the oxidative degradation of the samples were following by measuring the molecular weight change of the polymer by gel permeation chromatography (coupled with both differential refractive index and multiangle laser light scattering detectors). Multiple temperatures between 40 and 64 degreeC were used to accelerate the aging of the samples. Interesting induction period behavior, along with both molecular weight increasing (cro...

2009-01-01

86

Light emission from hydrogen-copper interaction at grazing incidence  

Energy Technology Data Exchange (ETDEWEB)

The optical emission of excited H reflected from clean Cu(110) after impingement of H/sup +/ and H/sub 2//sup +/ in the energy range of 250 eV to 20 keV per nucleon at 70/sup 0/ angle of incidence to the surface normal was measured. For incident 10 keV H/sub 2//sup +/, the highest excited hydrogen state detected was the n=10 level. The Hsub(..cap alpha..) yield was found to be fluence and energy dependent. This effect is attributed either to fast sputtered hydrogen, surface roughness or to an increase with hydrogen concentration in electron states of p-like symmetry near the Fermi level of copper. The Hsub(..cap alpha..) yield per reflected nucleon shows approximately an exponential dependence on both projectile energy per nucleon and scattered particle reciprocal velocity perpendicular to the surface.

1984-03-01

87

Light emission from hydrogen-copper interaction at grazing incidence  

International Nuclear Information System (INIS)

The optical emission of excited H reflected from clean Cu(110) after impingement of H"+ and H_2"+ in the energy range of 250 eV to 20 keV per nucleon at 70"0 angle of incidence to the surface normal was measured. For incident 10 keV H_2"+, the highest excited hydrogen state detected was the n=10 level. The Hsub(#alpha#) yield was found to be fluence and energy dependent. This effect is attributed either to fast sputtered hydrogen, surface roughness or to an increase with hydrogen concentration in electron states of p-like symmetry near the Fermi level of copper. The Hsub(#alpha#) yield per reflected nucleon shows approximately an exponential dependence on both projectile energy per nucleon and scattered particle reciprocal velocity perpendicular to the surface. (orig.).

1983-07-01

88

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

89

Initial airborne CO{sub 2} DIAL measurements: Discussion of results and data analysis considerations  

Energy Technology Data Exchange (ETDEWEB)

A detailed discussion of airborne CO{sub 2}, DIAL measurements obtained from the first joint N-ABLE field campaign at INEL is presented. System performance characteristics, including return signal strength, averaging statistics, and temporal correlation as well as multi-line DIAL spectral data are discussed. In particular, we review data acquisition and analysis strategies pertinent to chemical detection from a moving platform, such as range determination and correction, and return signal processing (waveform vs. box-car integration, baseline correction). We also report observed effects and variations due to near-field light scattering, pointing and tracking stability, and stack-release plume dynamics.

1997-07-01

90

Influence of Population III stars on cosmic chemical evolution  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT New observations from the Hubble Ultra Deep Field suggest that the star formation rate at Formula Not Shown drops off faster than previously thought. Using a newly determined star formation rate for the normal mode of Population II/I (PopII/I) stars, including this new constraint, we compute the Thomson scattering optical depth and find a result that is marginally consistent with Wilkinson Microwave Anisotropy Probe 5 results. We also reconsider the role of Population III (PopIII) stars in light of cosmological and stellar evolution constraints. While this input may be needed for reionization, we show that it is essential in order to account for cosmic chemical evolution in the early universe. We investigate the consequences of PopIII stars on the local metallicity distribution fu...

2009-01-01

91

Identification of fatigue damage in cortical bone by diffraction enhanced imaging  

International Nuclear Information System (INIS)

In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.

2005-08-11

92

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

93

Characterization of Y2BaCuO5 nanoparticles synthesized by nano-emulsion method  

British Library Electronic Table of Contents (United Kingdom)

Nanoscale yttrium?barium?copper oxide (Y2BaCuO5, Y211) particles were synthesized using the emulsion method and the solution method. The basic water-in-oil (w/o) emulsion system consisted of n-octane (continuous oil phase), cetyltrimethylammonium bromide (cationic surfactant), butanol (cosurfactant) and water. The composition of the emulsion system was varied and characterized by measuring the conductivity of the solutions and droplet size. The droplet size of emulsion was determined by using the dynamic light scattering method. The water content, cosurfactant content, and surfactant/n-octane ratio affected the droplet size which was in the range of 3?8?nm, and hence the w/o emulsion system was referred to as a nano-emulsion system. A model was used to verify the droplet size. The influenc...

2007-01-01

94

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

95

Banana peel extract mediated synthesis of gold nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Gold nanoparticles were synthesized by using banana peel extract (BPE) as a simple, non-toxic, eco-friendly 'green material'. The boiled, crushed, acetone precipitated, air-dried peel powder was used to reduce chloroauric acid. A variety of nanoparticles were formed when the reaction conditions were altered with respect to pH, BPE content, chloroauric acid concentration and temperature of incubation. The reaction mixtures displayed vivid colors and UV-vis spectra characteristic of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size of the nanoparticles under standard synthetic conditions was around 300nm. Scanning electron microscopy and energy dispersive spectrometry (EDS) confirmed these results. A coffee ring phenomenon, led to the aggregation of th...

2010-01-01

96

Banana peel extract mediated novel route for the synthesis of palladium nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Bio-inspired palladium nanoparticles were synthesized by using banana peel extract (BPE), a non-toxic eco-friendly material. Boiled, crushed, acetone precipitated, air-dried peel powder was used to reduce palladium chloride. The palladium nanoparticles were characterized by using UV-Visible spectroscopy, scanning electron microscope-energy dispersive spectra (SEM-EDS) and X-ray diffraction (XRD) analysis. Dynamic light scattering (DLS) studies revealed the average size of nanoparticles to be 50nm. Fourier transform infra red spectroscopy (FTIR) implicated the role of carboxyl, amine and hydroxyl groups in the synthetic process. This paper thus describes a novel green method for the synthesis of palladium nanoparticles.

2010-01-01

97

THE OGIP FORMAT FOR 2-D (IMAGE) POINT SPREAD FUNCTION ... - NASA  

Science.gov (United States)

tial/angular spreading of incident photons from a point source caused by the instrument (de- .... Filter. CDTP0001= 'DATA. ' / Type of calibration. CCNM0001= '2D_PSF ' ... the final resolution of sigma=0.5 arcmin in all energy bands. ...

98

Functional and Behavioral Restoration of Vision by Gene Therapy in the Guanylate Cyclase-1 (GC1) Knockout Mouse  

UK PubMed Central (United Kingdom)

BackgroundRecessive mutations in guanylate cyclase-1 (Gucy2d) are associated with severe, early onset Leber congenital amaurosis-1(LCA1). Gucy2d...Full Text Available

99

Dose verification of helical tomotherapy intensity modulated radiation therapy planning using 2D-array ion chambers  

UK PubMed Central (United Kingdom)

Purpose:To investigate the clinical usage of dose verification of Helical Tomotherapy plans by using 2D-array ion chambers, and to develop an efficient way to validate the dose delivered...Full Text Available

100

A new method for 2D gel spot alignment: application to the analysis of large sample sets in clinical proteomics  

UK PubMed Central (United Kingdom)

BackgroundIn current comparative proteomics studies, the large number of images generated by 2D gels is currently compared using spot matching algorithms. Unfortunately, differences...Full Text Available

101

Rayleigh Laser Guide Star Systems UnISIS Bow Tie Shutter and CCD39 Wavefront Camera  

CERN Document Server

Laser guide star systems based on Rayleigh scattering require some means to deal with the flash of low altitude laser light that follows immediately after each laser pulse. These systems also need a fast shutter to isolate the high altitude portion of the focused laser beam to make it appear star-like to the wavefront sensor. We describe how these tasks are accomplished with UnISIS, the Rayleigh laser guided adaptive optics system at the Mt. Wilson Observatory 2.5-m telescope. We use several methods: a 10,000 RPM rotating disk, dichroics, a fast sweep and clear mode of the CCD readout electronics on a 10 $\\mu$s timescale, and a Pockel's cell shutter system. The Pockel's cell shutter would be conventional in design if the laser light were naturally polarized, but the UnISIS 351 nm laser is unpolarized. So we have designed and put into operation a dual Pockel's cell shutter in a unique bow tie arrangement.

2002-01-01

102

DISSIPATION AND EXTRA LIGHT IN GALACTIC NUCLEI. III. 'CORE' ELLIPTICALS AND 'MISSING' LIGHT  

International Nuclear Information System (INIS)

We investigate how 'extra' or 'excess' central light in the surface brightness profiles of cusp or power-law elliptical galaxies relates to the profiles of ellipticals with cores. The envelopes of cusp ellipticals are established by violent relaxation in mergers acting on stars present in gas-rich progenitor disks, while their centers are structured by the relics of dissipational, compact starbursts. Ellipticals with cores are formed by the subsequent merging of the now gas-poor cusp ellipticals, with the fossil starburst components combining to preserve a dense, compact component in these galaxies as well (although mixing of stars smooths the transition from the outer to inner components in the profiles). By comparing extensive hydrodynamical simulations to observed profiles spanning a broad mass range, we show how to observationally isolate and characterize the relic starburst component in core ellipticals. Our method recovers the younger starburst population, ...

2009-04-01

103

Temperature-induced fusion of small unilamellar vesicles formed from saturated long-chain lecithins and diheptanoylphosphatidylcholine  

Energy Technology Data Exchange (ETDEWEB)

Small unilamellar vesicles which form when gel-state long-chain phosphatidylcholines are mixed with micellar short-chain lecithins undergo an increase in size as the long-chain species melts to its liquid-crystalline form. Analysis of the vesicle population with quasi-elastic light scattering shows that the particle size increases from 90-A radius to greater than 5000-A radius. Resonance energy transfer experiments show total mixing of lipid probes with unlabeled vesicles only when the Tm of the long-chain phosphatidylcholine is exceeded. This implies that the large size change represents a fusion process. Aqueous compartments are also mixed during this transition. 31P NMR analysis of the vesicle mixtures above the phase transition shows a great degree of heterogeneity with large unilamellar particles coexisting with oligo- and multilamellar structures. Upon cooling the vesicles below the Tm, the original size distribution (e.g., small ...

1989-10-03

104

Surface activity at the planar interface in relation to the thermodynamics of intermolecular interactions in the ternary system: maltodextrin-small-molecule surfactant-legumin.  

Science.gov (United States)

We report on the effect of potato maltodextrins with variable dextrose equivalent (Paselli SA-2, SA-6 and SA-10) on the surface behavior at the air-water interface of the mixture: legumin+small-molecule surfactant. Distinct in nature small-molecule surfactants (model: sodium salt of capric acid, Na-caprate; and commercially important: a citric acid ester of monoglyceride, CITREM) have been under our consideration. The role of the structure of both of the maltodextrins and the small-molecule surfactants in the effect studied has been elucidated by measurements in a bulk aqueous medium of the enthalpy of their interaction from mixing calorimetry, value of weight average molecular weight of the maltodextrins and the thermodynamics of the pair maltodextrin-solvent and maltodextrin-protein interactions from laser static light scattering. The combined data of mixing calorimetry and light scattering suggest ...

2001-07-01

105

Optical characterization of long-term ordered and nanocrystalline GaP  

International Nuclear Information System (INIS)

The paper generalizes some results of the United States/Moldova program on advanced composite organic and semiconductor light emitters. High density exciton system bound to N impurity superlattice grown by modern technologies and GaP:N, GaP:N:Sm nanocrystals distributed in transparent fluorine-containing polymers will be used as the base elements for new generation of optoelectronic devices. The work seeks to expand further the applications of GaP itself through the formation of nanocomposites. Classic and new methods are applied for preparation of GaP:N nanoparticles with the controlled dimensions developed clear quantum confinement effect. The long-term ordered bulk GaP crystals as well as their nanoparticles have been investigated by TEM, XRD, Raman scattering, and luminescent methods. The evolution of the Raman Light Scattering and luminescence spectra is reported from pure and doped GaP single ...

106

Point-contact Andreev-reflection spectroscopy in MgB{sub 2}: The role of substitutions  

Energy Technology Data Exchange (ETDEWEB)

We summarize the results of point-contact Andreev-reflection (PCAR) spectroscopy in MgB{sub 2} doped by chemical substitutions, either magnetic (Mn) or non-magnetic (Al,C), obtained by us and by other groups in the last four years. Despite the variety of samples used (crystals and polycrystals of various origin) and some minor differences in the experimental techniques, these measurements have directly provided a complete and consistent picture of the effects of chemical substitutions on the gaps of MgB{sub 2} shedding light on other relevant parameters (scattering rates, DOSs) affected by doping. In Al-doped crystals and polycrystals, the gap amplitudes {delta}{sub {sigma}} and {delta}{sub {pi}} - obtained through a two-band Blonder-Tinkham-Klapwijk (BTK) fit of the Andreev-reflection conductance curves - decrease on increasing the Al content x (i.e. on decreasing the critical temperature of the contacts T{sub c}{sup A}), but remain clearly ...

2007-06-01

107

Vibrational dynamics of hydrogen and deuterium in crystalline Pd_9Si_2  

International Nuclear Information System (INIS)

Crystalline Pd_9Si_2 possesses an orthorhombic structure (Pnma) that is characterized by augmented triangular prismatic coordination of the silicon atoms such as that which occurs in several metal-rich transition-metal silicides. Recent neutron diffraction results for deuterium solution in this crystalline phase have indicated that deuterium occupies only one type of interstice, i.e., a Pd-defined pyramidal site in a four-fold position situated on a quadrilateral face of an empty triangular prism. The vibrational dynamics of both H and D located at this site were investigated by neutron vibrational spectroscopy. The low-temperature density of states (DOS) of H in Pd_9Si_2H_0_._2_5 indicates three well-defined optic vibrations located at 49.4, 67.2 and 75.5 meV. The lowest-energy feature is assigned to the normal-mode vibration perpendicular to the pyramidal base and the two higher-energy features are assigned to the two orthogonal normal-mode vibrations parallel to this base. The ...

1996-08-25

108

Human Mammary Luminal Epithelial Cells Contain Progenitors to Myoepithelial Cells  

Energy Technology Data Exchange (ETDEWEB)

The origin of the epithelial and myoepithelial cells in the human breast has not been delineated. In this study we have addressed whether luminal epithelial cells and myoepithelial cells are vertically connected, i.e., whether one is the precursor for the other. We used a primary culture assay allowing preservation of basic phenotypic traits of luminal epithelial and myoepithelial cells in culture. The two cell types were then separated immunomagnetically using antibodies directed against lineage-specific cell surface antigens into at best 100% purity. The cellular identity was ascertained by cytochemistry, immunoblotting, and 2-D gel electrophoresis. Luminal epithelial cells were identified by strong expression of cytokeratins 18 and 19 while myoepithelial cells were recognized by expression of vimentin and {alpha}-smooth muscle actin. We used a previously devised culture medium (CDM4) that allows vigorous expansion of proliferative ...

1999-02-01

109

Electronic instabilities and the martensitic transition in A-15 compounds  

International Nuclear Information System (INIS)

The structural transition and anomalous properties of the high temperature A-15 superconductors have been investigated from two different standpoints. The first is a Landau theory based on Gorkov's physical model of a Peierls-like charge density wave (CDW) transition involving electronic CDW order parameters coupled to phonon coordinates. Pretransition elastic anomalies, softening of the [1 anti 10] transverse ([1 anti 10] polarized) phonon, sublattice distortions, variation of transition temperature with stress and alloying and other effects have been accurately predicted, and a detailed comparison is made with experimental results. Central peaks in neutron scattering are shown to be non-dynamic in nature and no pretransition forbidden (300) reflection is predicted. The GAMMA_1_2 optic mode does not go soft at the transition, though its frequency is expected to be temperature dependent right up to room temperature. A tight binding, two (3-D) band model of the A-15 ...

110

Noise suppression in scatter correction for cone-beam CT  

UK PubMed Central (United Kingdom)

Scatter correction is crucial to the quality of reconstructed images in x-ray cone-beam computed tomography (CBCT). Most of existing scatter correction methods assume smooth scatter distributions. The...Full Text Available

2009-03-01

112

Coulomb scattering for scalar field in Schroedinger picture  

Energy Technology Data Exchange (ETDEWEB)

The scattering of a charged scalar field on Coulomb potential on de Sitter space-time is studied using the solution of the free Klein-Gordon equation. We find that the scattering amplitude is independent of the choice of the picture and in addition the total energy is conserved in the scattering process.

2008-07-31

114

Light Infantry Division Assessment  

Science.gov (United States)

... LIGHT INFANTRY DIVISION ASSESSMENT LOl 0 BY ... TYPE OF REPORT & PERIOD COVERED LIGHT INFANTRY DIVISION ASSESSMENT ...

1990-04-02

115

The Light Infantry Division: How Many Are Needed  

Science.gov (United States)

Page 1. .v~ -. *° THE LIGHT INFANTRY DIVISION-HOW MANY ARE NEEDED? ,"- Lfl ... 7- Light Infantry Light Infantry Division 20. ...

1985-05-10

118

CT colonography: techniques of visualization and findings; CT Kolonographie: Techniken der Visualisierung und Befundung  

Energy Technology Data Exchange (ETDEWEB)

Evaluation and interpretation of CT colonography is based on both 2D and 3D techniques. The 2D techniques are popular mainly because the time needed for evaluation is short. The 3D techniques allow better definition than the 2D techniques, especially of polyps close to folds or at the base of a fold. The evaluation strategies generally accepted so far (primarily 2D, with 3D for problem cases, or vice versa) demand knowledge of both 2D and 3D techniques. Newer 3D visualization techniques help make it possible to acquire more complete and faster recording particularly of areas that are not easily accessible to endoscopic examination. These user-friendly developments are thus well suited to improving the detection and the security of detection of polyps. It must be remembered that ...

2008-02-15

119

On the properties of plasma crystals  

Energy Technology Data Exchange (ETDEWEB)

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

1999-07-01

120

Seismic tomography inversion in the case that sources and receivers are distributed out of a 2-D plane; Shingen jushinten ga nijigen heimennai ni nai baai no danseiha tomography kaiseki ni kansuru kosatsu  

Energy Technology Data Exchange (ETDEWEB)

In the case where sources and receivers are not distributed on a 2-D plane, seismic tomography inversion was studied. In tomography experiments, the existing wells are generally used. In such case, sources and receivers are frequently not distributed on a 2-D plane. The 2.5-D analysis method including 2-D structure and 3-D ray-tracing was thus developed. This method is featured by less memory necessary for ray-tracing calculation, and the same algorithm for velocity determination as 2-D analysis method. In previous methods, since analysis is generally carried out by projecting sources and receivers on a certain assumed 2-D plane, it can derive correct results in the case of constant velocity and straight ray, however, in the other case, it derives incorrect results. Application ...

1996-10-01

121

A New Approach to Studying Biological and Soft Materials Using Focused Ion Beam Scanning Electron Microscopy (FIB SEM)  

International Nuclear Information System (INIS)

Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combination of sample preparation techniques and transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). Scanning electron microscopy (SEM) is well known for the determination of surface characteristics and morphology. However, the desire to understand the three dimensional relationships of meso-scale hierarchies has led to the development of advanced microscopy techniques, to give a further complementary approach. A focused ion beam (FIB) can be used as a nano-scalpel and hence allows us to reveal internal microstructure in a site-specific manner. Whilst FIB instruments have been used to study and verify the ...

2006-02-22

122

Quasilinear theory of the 2D Euler equation  

CERN Document Server

Motivated by the numerical investigations of Laval, Dubrulle & Nazarenko (1999), we develop a quasilinear theory of the 2D Euler equation and derive an integro-differential equation for the evolution of the coarse-grained vorticity. This equation respects all the invariance properties of the Euler equation and conserves angular momentum in a circular domain and linear impulse in a channel (as well as in an infinite domain). The explicit energy is not rigorously conserved as it is partly transfered into fine-grained fluctuations but the total energy is conserved. We prove a H-theorem for the Fermi-Dirac entropy and make the connection with statistical theories of 2D turbulence.

2000-01-01

123

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, ...

124

Sandia National Labs: PCNSC: Departments: Semiconductor Material...  

Science.gov (United States)

For coupled quantum wires and dots, tunneling effects and coherent transport for quantum computing are being studied. In 2D systems, electron-hole bilayers for exciton...

2011-07-05

125

Planet Forming Protostellar Disks - NASA Technical Report Server ...  

Science.gov (United States)

terms of 11) numerical models, 2D SPH simulations, and analytic models. The 1D model was useful for determining the evolution over very long timescales. ...

126

Filopodia  

UK PubMed Central (United Kingdom)

The processes of neuronal outgrowth and guidance have typically been studied in classic 2D cell culture systems that do not recapitulate topographical cues present in the in vivo extracellular matrix...Full Text Available

2011-07-01

129

Appendix A 1994 Fish and Wildlife Service and National Marine Fisheries Service  

Science.gov (United States)

... is not a "significant portion of its range." Asarco, Inc. v. EPA, 616 F.2d 1153, 1159 ( ... ...

130

An improved model for natural convection heat loss from modified cavity receiver of solar dish concentrator  

British Library Electronic Table of Contents (United Kingdom)

A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparabl...

2009-01-01

133

CERN's 'Big Bang' experiment given green light  

CERN Document Server

CERN's 'Big Bang' experiment given green light

2008-01-01

134

Bilayer Lipid Membranes for Light Converters  

International Science & Technology Center (ISTC)

Bilayer Lipid Membrane Supported Novel Photoelectrochemical Converter for Light Trapping

135

Big Bang experiment given green light  

CERN Document Server

Big Bang experiment given green light

2008-01-01

136

Vesicle stabilization and destabilization for application in chemical reagent storage and release. Final progress report, 15 June 1091-30 November 1995  

Energy Technology Data Exchange (ETDEWEB)

The project involved several studies of vesicles and micelles and their constituent surfactants. The primary objective of the project was an elucidation of factors involved in the stabilization and destabilization of vesicles and micelles. Work was performed on seven individual studies. Several different types of novel cleavable surfactants were synthesized, including systems with two chains and two head groups, and their aqueous micelles and vesicles were characterized by methods including dynamic laser light scattering (to give aggregate sizes) and differential scanning calorimetry (to give vesicle bilayer phase transition temperatures). A cleavable surfactant is stable under certain conditions but liable under other conditions with respect to cleavage to give nonsurfactant products and/or other surfactants with different properties. The destruction of several cleavable surfactant-derived aggregates was demonstrated, indicating that they have ...

1996-03-19

137

Tissue perfusion measurements: multiple-exposure laser speckle analysis generates laser Doppler-like spectra  

Science.gov (United States)

Variations in skin perfusion are easily detected by laser speckle contrast maps, but a robust interpretation of the information has been lacking. We show that multiple-exposure laser speckle methods produce the same spectral information as laser Doppler methods when applied to targets with embedded moving scatterers. This enables laser speckle measurements to be interpreted more quantitatively. We do this by using computer simulation of speckle data, and by experimental measurements on Brownian motion and skin perfusion using a laser Doppler system and a multiple-exposure laser speckle system. The power spectral density measurements of the light fluctuations derived using both techniques are exactly equivalent. Dermal perfusion can therefore be measured by laser Doppler or laser speckle contrast methods. In particular, multiexposure laser speckle can be rapidly processed to generate a full-field map of the perfusion index proportional to the ...

2010-03-01

138

SEM and TEM investigations of recovery and recrystallization in technically pure molybdenum; REM- und TEM-Untersuchungen von Erholung und Rekristallisation in technisch reinem Molybdaen  

Energy Technology Data Exchange (ETDEWEB)

Beside traditional applications of refractory metals, e.g. in high temperature furnace construction, lighting or glass industry, one of the most important molybdenum products nowadays are large plates which are frequently used as targets for the sputtering of molybdenum layers in thin-film transistor liquid crystal displays. For the hot rolling of the sintered pre-material, the control over the recovery and recrystallization behavior is of particular importance. Molybdenum tends to a very recovery controlled behavior during hot deformation, at which the dislocations arrange into subcell boundaries instantaneously. These pronounced recovery processes seem to consume a large amount of the stored deformation energy for the actual recrystallization. On the other hand, recovery provides the future recrystallization nuclei. For a comprehensive characterization of these microstructural processes, electron microscopy appears to be the most proper means. The aim of this ...

2011-07-15

139

Real-time neutron radiography at the Iea-R1 m nuclear research reactor  

International Nuclear Information System (INIS)

A LIXI (Light Intensifier X-ray Image) device has been employed in a real-time neutron radiography system. The LIXI is coupled to a video camera and the real-time images can be observed in a TV monitor, and processed in a computer. In order to get the real-time system operational, the neutron radiography facility installed at the IEA-R1 m nuclear research reactor of the IPEN-CNEN/S P has been optimized. The most important improvements were the neutron/gamma ratio, the effective energy of the neutron beam, decrease of the scattered radiation at the irradiation position, and the additional shielding of the video camera. Several one-frame as well as computer processed images are presented. The overall Modulation Transfer Function for the real-time system was obtained from the resolution parameter p = 0:44 +- 0:04 mm; the system sensitivity, evaluated for a Perspex step wedge, was determined and the average value is 0:70 +- 0:09 mm. (author)

2003-06-01

140

Formation of colloidal silver nanoparticles stabilized by Na+-poly(gamma-glutamic acid)-silver nitrate complex via chemical reduction process.  

Science.gov (United States)

Macromolecular and polyanionic Na(+)-poly(gamma-glutamic acid) (PGA) silver nitrate complex acted as both a metal ion provider and a particle protector to fabricate nanosized silver colloids under chemical reduction by dextrose. The formation and size of particles have been characterized from transmission electron microscopy (TEM), dynamic light scattering analysis and UV-vis spectrophotometer. The results showed that the average particle size was 17.2+/-3.4 to 37.3+/-5.5 nm, apparently depending on the complex concentration. It was found that the rate constant and conversion of silver nanoparticles were proportional to the concentration of PGA. The growth mechanism of nanosized silver colloid was fully discussed. In addition, the in vitro cytotoxicity evaluated by L929 fibroblasts proliferation and antibacterial activity against Gram-positive strain (methicillin-resistant S. aureus (MRSA)) and Gram-negative strain (P. aeruginosa) bacteria have ...

2007-05-18

141

[Dependence of scattered Mn K alpha / K beta X-ray intensity ratio on the scatterer materials].  

Science.gov (United States)

The K alpha / K beta ratio of Mn KX-rays scattered by metallic samples changed remarkably with the geometry between the sample and the (55)Fe source-Si(Li) detector system. On the contrary, this intensity ratio changed little in the cases of non-metallic scatterer samples such as lucite or mylar. This difference is interpreted as due to the occurrence of strong or weak interference in the coherent scattering photons. PMID:7280291

1980-10-01

142

High energy proton-proton scattering and multiple scattering model including inelastic intermediate states  

International Nuclear Information System (INIS)

The cross sections for proton-proton elastic scattering at Fermilab and ISR energies are investigated in the framework of the multiple constituent scattering formalism, including the contributions of the inelastic intermediate states. We find that the higher-order multiple scattering amplitudes are strongly suppressed due to the presence of the inelastic intermediate states. The calculated cross sections reproduce the high energy experimental data fairly well. (author).

143

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

144

Mercury flow experiments. 3. Simulation test plan under abnormal condition  

Energy Technology Data Exchange (ETDEWEB)

Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) are promoting construction plan of Material-Life Science Facility, which is consisted of Muon Science Facility and Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutrons generated by the spallation reaction induced by injecting a 1 MW pulsed proton beam onto a mercury target. Design of the spallation mercury target system is in progress to obtain good neutron performance keeping high reliability and safety. The target material is mercury. As a result of the spallation reaction, large amount of radioactive spallation products are to be contained in the mercury. Therefore to establish the safety of the target system, transient behaviors of the system during anticipated events should be well understood. ...

2002-02-01

145

Synthesis and stereochemical effects of pyrrolidinyl-acetylenic thieno[3,2-d]pyrimidines as EGFR and ErbB-2 inhibitors  

British Library Electronic Table of Contents (United Kingdom)

A novel class of pyrrolidinyl-acetyleneic thieno[3,2-d]pyrimidines has been identified which potently inhibit the EGFR and ErbB-2 receptor tyrosine kinases. Synthetic modifications of the pyrrolidine carbamate moiety result in a range of effects on enzyme and cellular potency. In addition, the impact of the absolute stereochemical configuration on cellular potency and oral mouse pharmacokinetics is described.

2009-01-01

146

Dramatic Effects of 2-Bromo-5,6-Dichloro-1-?-d-Ribofuranosyl Benzimidazole Riboside on the Genome Structure, Packaging, and Egress of Guinea Pig Cytomegalovirus  

UK PubMed Central (United Kingdom)

The halogenated benzimidazoles BDCRB (2-bromo-5,6-dichloro-1-;2;-d-riborfuranosyl benzimidazole riboside) and TCRB (2,5,6-trichloro-1-;2;-d-riborfuranosyl benzimidazole...Full Text Available

2004-02-01

147

Accurate positioning for head and neck cancer patients using 2D and 3D image guidance  

UK PubMed Central (United Kingdom)

Our goal is to determine an optimized image-guided setup by comparing setup errors determined by two-dimensional (2D) and three-dimensional (3D) image guidance for head and neck cancer (HNC)...Full Text Available

148

2DIR spectroscopic studies on cholic acid  

Science.gov (United States)

Based on our cryogenic FT-IR spectroscopic studies of hydrogen bonds in cholic acid, the two-dimensional FT-IR spectroscopy was applied to enhance our understanding of the hydrogen bonds. Fine spectral structures were revealed by asynchronous 2D FT-IR spectra. The co-relationship among various bands was discussed according to the synchronous 2D FT-IR spectra. .

2000-03-01

149

Theory of chemical reaction dynamics. Volume 3  

Energy Technology Data Exchange (ETDEWEB)

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

1985-01-01

150

Quantitative imaging of turbulent and reacting flows  

Energy Technology Data Exchange (ETDEWEB)

Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing ...

1993-12-01

151

Optical Properties and Wave Propagation in Semiconductor-Based Two-Dimensional Photonic Crystals  

Energy Technology Data Exchange (ETDEWEB)

This work is a theoretical investigation on the physical properties of semiconductor-based two-dimensional photonic crystals, in particular for what concerns systems embedded in planar dielectric waveguides (GaAs/AlGaAs, GaInAsP/InP heterostructures, and self-standing membranes) or based on macro-porous silicon. The photonic-band structure of photonic crystals and photonic-crystal slabs is numerically computed and the associated light-line problem is discussed, which points to the issue of intrinsic out-of-lane diffraction losses for the photonic bands lying above the light line. The photonic states are then classified by the group theory formalism: each mode is related to an irreducible representation of the corresponding small point group. The optical properties are investigated by means of the scattering matrix method, which numerically implements a variable-angle-reflectance experiment; comparison with experiments is ...

2002-12-31

152

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-10-11

153

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

International Nuclear Information System (INIS)

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

2001-10-11

154

Flow-system analysis of exfoliated pulmonary cells: results of initial characterization studies in hamsters  

Science.gov (United States)

This paper summarizes results of preliminary experiments to develop cytological and biochemical indicators for estimating damage to respiratory cells in test animals exposed by inhalation to toxic agents associated with nonnuclear energy production, the specific goal being the application of advanced multiparameter flow-systems technologies to the detection of early atypical cellular changes in lung epithelium. Normal Syrian hamster lung cell samples composed of histiocytes, leukocytes, macrophages, ciliated columnar cells, and epithelial cells were stained with fluorescent dyes specific for different biochemical parameters and were analyzed in liquid suspension as they flowed through a chamber intersecting a laser beam of exciting light. Multiple sensors measured the total or two-color fluorescence and light scatter on a cell-by-cell basis. Cellular parameters proportional to optical measurements (i.e., cell size, DNA ...

1976-01-01

155

The EMCC/DARPA*Massively Parallel Electromagnetic Scattering Project  

Science.gov (United States)

The EMCC/DARPA*Massively. Parallel. Electromagnetic. Scattering. Project. Alex C . Wootand. Kueichien. C. Hill s. Report. NAS-96-008,. August, ...

157

Inelastic electron scattering, M1 giant resonances and the quest for subnuclear degrees of freedom  

International Nuclear Information System (INIS)

... electrons fine structure giant resonance inelastic scattering iron 54 iron 54

1983-01-17

158

Feynman path integral representations for wave scattering by anisotropic perturbations  

Energy Technology Data Exchange (ETDEWEB)

We write a space-time Feynman Path Integral representation for scattered wave fields from a weakly/compact supported anisotropic non-homogeneity. (author)

2007-07-01

159

Wire-shaped semiconductor light-emitting diodes for general-purpose lighting  

Energy Technology Data Exchange (ETDEWEB)

The object of this work is to develop and optimize a new type of light-emitting diode (LED) with a wire-shaped, cylindrical geometry.

2002-10-28

160

Light Weight Composite Mirrors for Science Instruments  

Science.gov (United States)

Light Weight Composite Mirrors for Science Instruments. Composite Optics, Inc. San Diego, CA. INNOVATION. Light weight, large aperture reflectors of graphite ...

161

Characterization of Single-Cylinder Small-Bore 4-Stroke CIDI Engine Combustion  

Energy Technology Data Exchange (ETDEWEB)

Direct injection diesel engines power most of the heavy-duty vehicles. Due to their superior fuel economy, high power density and low carbon dioxide emissions, turbocharged, small bore, high speed, direct injection diesel engines are being considered to power light duty vehicles. Such vehicles have to meet stringent emission standards. However, it is difficult to meet these standards by modifying the in-cylinder thermodynamic and combustion processes to reduce engine-out emissions. After-treatment devices will be needed to achieve even lower emission targets required in the production engines to account for the anticipated deterioration after long periods of operation in the field. To reduce the size, mass and cost of the after-treatment devices, there is a need to reduce engine-out emissions and optimize both the engine and the aftertreatment devices as one integrated system. For example, the trade-off between engine-out NOx and PM, suggests that one of these ...

2005-11-30

163

Intraband Absorptoin of Far-Infrared Light by Electrons in ...  

Science.gov (United States)

... significant change of spontaneous radiation intensity. It is very sensitive technique allowing the observation of small changes of light absorption. ...

1999-06-18

166

Rayleigh scattering of Moessbauer radiation in hyaluronate oriented fibres  

Energy Technology Data Exchange (ETDEWEB)

The Rayleigh scattering of Moessbauer radiation has been measured on highly oriented fibres of Na-hyaluronate at different hydration levels. The elastic- and-inelastic-scattering intensities, measured as a function of the scattering vector Q, have provided information on the dynamic structuring of the water molecules to the polysaccharidic chains.

1996-02-01

167

Rayleigh Scattering in Rare Gas Liquids  

CERN Document Server

The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the gas phase, except in the case of xenon for which measurements are available in the liquid. The scattering length mayplace constraints on the design of some large-scale detectors, using uv luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas mixtures is also discussed.

2002-01-01

168

Neutron scattering studies in the actinide region. Progress report, August 1, 1992--July 31, 1993  

Energy Technology Data Exchange (ETDEWEB)

This report discusses the following topics: Prompt fission neutron energy spectra for {sup 235}U and {sup 239}Pu; Two-parameter measurement of nuclear lifetimes; ``Black`` neutron detector; Data reduction techniques for neutron scattering experiments; Inelastic neutron scattering studies in {sup 197}Au; Elastic and inelastic scattering studies in {sup 239}Pu; and neutron induced defects in silicon dioxide MOS structures.

1993-09-01

173

Locally resonant acoustic metamaterials with 2D anisotropic effective mass density  

British Library Electronic Table of Contents (United Kingdom)

A two-dimensional (2D) lattice model with anisotropic resonant microstructures is found to provide an anisotropic band gap structure. A 2D continuum with anisotropic effective mass density is introduced to represent this lattice system. Two methods are proposed to derive the equivalent continuum. In the first method, the effective mass density of the equivalent continuum is obtained by matching the dispersion relations for harmonic waves propagating in the principal directions. The second approach employs an approximate estimation of the effective mass density by volume-averaging an effective mass that represents the resonant microstructure. For both equivalent continuum models, the effective mass density is frequency-dependent and may become negative in certain frequency ranges. Subsequen...

2011-01-01

174

Estimating Field Volatility of Soil Fumigants Using CHAIN_2D: Mitigation Methods and Comparison Against Chloropicrin and 1,3-Dichloropropene Field Observations  

British Library Electronic Table of Contents (United Kingdom)

Academic, government, and industrial field researchers have generated a significant database of field studies of the volatility of soil applied fumigants. However, limited work exists in validating physical models against field volatility data sets and fully exploring the volatility parametric response surface. Field studies quantifying atmospheric flux for soil fumigants 1,3-dichloropropene and chloropicrin are validated against the United States Department of Agriculture (USDA Salinity Laboratory) soil physics model CHAIN_2D that was modified specifically for agronomic uses of soil fumigants. Comparison between model predictions and field observations for six unique field trials in five different states indicate that CHAIN_2D effectively captures the magnitude and duration of fumigant em...

2010-01-01

175

Effects of Sleep Apnea Severity on Glycemic Control in Patients with Type 2 Diabetes Prior to Continuous Positive Airway Presssure Treatment  

British Library Electronic Table of Contents (United Kingdom)

Abstract Background: Obstructive sleep apnea (OSA), a highly prevalent condition, is independently associated with increased risks of developing type 2 diabetes mellitus (T2D) and metabolic syndrome. It is unclear, however, if the severity of OSA has any impact on glycemic control among patients with T2D. We therefore aimed to determine the independent association between OSA severity and glycosylated hemoglobin (HbA1c) in patients with T2D. Methods: This was an observational cross-sectional study of 52 consecutive patients attending the diabetes obesity clinic between January 2008 to February 2010 with risk factors for sleep apnea and who underwent polysomnography study. Clinical, demographic, and lifestyle data were recorded using a questionnaire. Results: Prevalence of OSA in this clini...

2011-01-01

176

2D SPH simulations of planet-disc interactions.  

Science.gov (United States)

Current theories on planetary formation establish that massive objects accrete gaseous envelopes, becoming gaseous planets if the accretion process proceeds before the accretion disc dissolution. One of the unsolved problems is that the planet formation is contextual to their quick migration towards the central star, due to the protoplanets-disc interaction, on a timescale lower by an order of magnitude than that of gas accretion onto the protoplanet. These arguments have been recently broached using N-body and/or Eulerian fluid-dynamics codes, mainly in 2D, or a mixing of them. In this work, 2D simulations with a SPH code are performed, to study the migration of one protoplanet. The goal is to scrutinise the protoplanet dragging as a function of planet's mass.

2009-01-01

177

The interaction of fast N"+_2 ions with a Ni(111) surface  

International Nuclear Information System (INIS)

In the context of sputtering experiments, studying the back-scattering of fast ion beams is a useful way to study inelastic ion-surface interactions, since then the trajectories and energies of the particles are well defined. This same argument holds for the scattering of fast molecular ions. We give a short account of our experiment where N"+_2 was scattered from a Ni(111) surface. The measured energy distributions of scattered N atoms are discussed with regard to vibrational and rotational energy transfer during scattering. (G.Q.).

1986-02-01

178

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

179

Inelastic scattering of He atoms from Cu(001) at low temperature with energy analysis  

International Nuclear Information System (INIS)

A LiF crystal analyzer has been used to measure phonon creation events when a low energy He beam scatters from a Cu(001) surface at low temperature (16 "0K). As only phonon creation events were observed, the inelastic scattering was subspecular. Atom parallel momentum gain and loss events were observed and both bulk and surface modes contributed to the inelastic scattering. An elastic component of scattering was observed over a wide angular range.

1981-09-01

180

Dependence of scattered Mn K sub(#alpha#)/K sub(#beta#) x-ray intensity ratio on the scatterer materials  

International Nuclear Information System (INIS)

The K sub(#alpha#)/K sub(#beta#) intensity ratio of Mn KX-rays scattered by metallic samples changed remarkably with the geometry between the sample and the "5"5Fe source-Si(Li) detector system. On the contrary, this intensity ratio changed little in the cases of non-metallic scatterer samples such as lucite or mylar. This difference is interpreted as due to the occurrence of strong or weak interference in the coherent scattering photons. (author).

1980-01-01

181

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

International Nuclear Information System (INIS)

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

182

Comparison and Physical Interpretation of MCNP and TART Neutron and Gamma Monte Carlo Shielding Calculations for a Heavy-Ion ICF System  

Energy Technology Data Exchange (ETDEWEB)

For heavy-ion beam driven inertial fusion ''liquid-protected'' reactor designs such as HYLIFE-II, a mixture of molten salts made of F{sup 10}, Li{sup -6}, Li{sup 7} and Be{sup 9} (called flibe) allows small chambers and final-focus magnets closer to the target with superconducting coils suffering higher radiation damage, though they can stand only a certain amount of energy deposited before quenching. This work has been primarily focusing on verifying that total energy deposited by fusion neutrons and induced gamma rays remain under such limit values and the final purpose is the optimization of the shielding of the magnetic lens system from the points of view of the geometrical configuration and of the physical nature of the materials adopted. The system is analyzed in terms of six geometrical models going from simplified up to much more realistic representations of a system of 192 beam lines, each focused by six magnets. A 3-D transport calculation ...

2002-07-01

183

Characterization of an add-on multileaf collimator for electron beam therapy  

Energy Technology Data Exchange (ETDEWEB)

An add-on multileaf collimator for electrons (eMLC) has been developed that provides computer-controlled beam collimation and isocentric dose delivery. The design parameters result from the design study by Gauer et al (2006 Phys. Med. Biol. 51 5987-6003) and were configured such that a compact and light-weight eMLC with motorized leaves can be industrially manufactured and stably mounted on a conventional linear accelerator. In the present study, the efficiency of an initial computer-controlled prototype was examined according to the design goals and the performance of energy- and intensity-modulated treatment techniques. This study concentrates on the attachment and gantry stability as well as the dosimetric characteristics of central-axis and off-axis dose, field size dependence, collimator scatter, field abutment, radiation leakage and the setting of the accelerator jaws. To provide isocentric irradiation, the eMLC can be placed either 16 or ...

2008-02-21

184

Simple fractal method of assessment of histological images for application in medical diagnostics  

UK PubMed Central (United Kingdom)

We propose new method of assessment of histological images for medical diagnostics. 2-D image is preprocessed to form 1-D landscapes or 1-D signature of the image contour and then their complexity is...Full Text Available

185

New insight on the interaction and diffusion properties of ion beam injected self-interstitials in crystalline silicon  

Energy Technology Data Exchange (ETDEWEB)

The diffusion of ion beam injected self-interstitials (I) and their interaction with impurities in crystalline Si has been investigated and modeled. In particular, the I-substitutional carbon (C) interactions have been studied, using a molecular-beam-epitaxy grown Si{sub 1-y}C{sub y} layer interposed between the shallow I-source and a deeper B-spike (marker for I-concentration). Substitutional C atoms are shown to trap I's, to be removed from their substitutional sites, and to form stable precipitates into the C-rich region. The I-trapping mechanism was quantitatively studied by a simulation code. The reactions causing trapping and deactivation are described. In addition, the boron markers approach was extended to the two dimensional (2D) diffusion. High resolution scanning capacitance microscopy was used for quantitative measurements of the 2D boron transient enhanced diffusion induced on a ...

2003-05-01

186

New insight on the interaction and diffusion properties of ion beam injected self-interstitials in crystalline silicon  

International Nuclear Information System (INIS)

The diffusion of ion beam injected self-interstitials (I) and their interaction with impurities in crystalline Si has been investigated and modeled. In particular, the I-substitutional carbon (C) interactions have been studied, using a molecular-beam-epitaxy grown Si_1_-_yC_y layer interposed between the shallow I-source and a deeper B-spike (marker for I-concentration). Substitutional C atoms are shown to trap I's, to be removed from their substitutional sites, and to form stable precipitates into the C-rich region. The I-trapping mechanism was quantitatively studied by a simulation code. The reactions causing trapping and deactivation are described. In addition, the boron markers approach was extended to the two dimensional (2D) diffusion. High resolution scanning capacitance microscopy was used for quantitative measurements of the 2D boron transient enhanced diffusion induced on a boron delta array ...

2003-05-01

187

MudPIT Analysis: Application to Human Heart Tissue  

UK PubMed Central (United Kingdom)

Although two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) has been used as the standard proteomic approach for separating proteins in a complex mixture, this technique has many drawbacks....Full Text Available

2009-01-01

188

Mapping Proprioception across a 2D Horizontal Workspace  

UK PubMed Central (United Kingdom)

Relatively few studies have been reported that document how proprioception varies across the workspace of the human arm. Here we examined proprioceptive function across a horizontal planar workspace,...Full Text Available

189

Large-scale association analysis of TNF/LTA gene region polymorphisms in type 2 diabetes  

UK PubMed Central (United Kingdom)

BackgroundThe TNF/LTA locus has been a long-standing T2D candidate gene. Several studies have examined association of TNF/LTA...Full Text Available

190

Increased SRF transcriptional activity in human and mouse skeletal muscle is a signature of insulin resistance  

UK PubMed Central (United Kingdom)

Insulin resistance in skeletal muscle is a key phenotype associated with type 2 diabetes (T2D) for which the molecular mediators remain unclear. We therefore conducted an expression analysis of human...Full Text Available

2011-03-01

191

Effects of Protons and HZE Particles on Glutamate Transport in Astrocytes, Neurons and Mixed Cultures  

Science.gov (United States)

... ions. MATERIALS AND METHODS Cell Culture Culture of NT2/D1 cells was carried out as described previously (18, 19). NT2 cells were plated at a density of 2. ... ...

192

Ct3d: tracking microglia motility in 3D using a novel cosegmentation approach  

UK PubMed Central (United Kingdom)

Motivation: Cell tracking is an important method to quantitatively analyze time-lapse microscopy data. While numerous methods and tools exist for tracking cells in 2D time-lapse images,...Full Text Available

2011-02-15

193

Binary pseudo-random gratings and arrays for calibration of the modulation transfer function of surface profilometers: recent developments  

Energy Technology Data Exchange (ETDEWEB)

The major problem of measurement of a power spectral density (PSD) distribution of the surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF tends to distort the PSD at higher spatial frequencies. It has been suggested [Proc. SPIE 7077-7, (2007), Opt. Eng. 47 (7), 073602-1-5 (2008)] that the instrumental MTF of a surface profiler can be precisely measured using standard test surfaces based on binary pseudo-random (BPR) patterns. In the cited work, a one dimensional (1D) realization of the suggested method based on use of BPR gratings has been demonstrated. Here, we present recent achievements made in fabricating and using two-dimensional (2D) BPR arrays that allow for a direct 2D calibration of the instrumental MTF. The 2D BPRAs were used as standard test surfaces for ...

2009-07-07

194

Binary Pseudo-Random Gratings and Arrays for Calibration of Modulation Transfer Function of Surface Profilometers  

Energy Technology Data Exchange (ETDEWEB)

In the present work, we describe application of binary pseudo-random gratings (BPRG) and arrays (BPRA) as effective 1D and 2D test surfaces suitable for calibration of different surface profilometers, including a number of interferometric microscopes and scatterometers.

2009-06-17

195

Beyond AICA Riboside: In Search of New Specific AMP-activated Protein Kinase Activators  

UK PubMed Central (United Kingdom)

Summary5-Aminoimidazole-4-carboxamide-1-;2;-d-ribofuranoside (AICA riboside) has been extensively used in vitro and in vivo to...Full Text Available

2009-01-01

196

Azimuth Quadrupole Systematics in Au-Au Collisions  

CERN Document Server

We have measured $p_t$-dependent two-particle number correlations on azimuth and pseudorapidity for eleven centralities of $\\sqrt{s_{NN}} = 62$ and 200~GeV Au-Au collisions at STAR. 2D fits to these angular correlations isolate the azimuth quadrupole amplitude, denoted $2 v_2^2 \\{ 2D \\} ( p_t )$, from localized same-side correlations. Event-plane $v_2 ( p_t )$ measurements within the STAR TPC acceptance can be expressed as a sum of the azimuth quadrupole and the quadrupole component of the same-side peak. $v_2 \\{ 2D \\} ( p_t )$ can be transformed to reveal quadrupole $p_t$ spectra which are approximately described by a fixed transverse boost and universal L\\'evy form nearly independent of centrality. A parametrization of $v_2 \\{ 2D \\} ( p_t )$ can be factored into centrality and $p_t$-dependent pieces with a ...

2010-01-01

197

An improved model for natural convection heat loss from modified cavity receiver of solar dish concentrator  

Energy Technology Data Exchange (ETDEWEB)

A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparable only at higher angle of ...

2009-10-15

198

A frequency-based approach to locate common structure for 2D-3D intensity-based registration of setup images in prostate radiotherapy  

UK PubMed Central (United Kingdom)

In many radiotherapy clinics, geometric uncertainties in the delivery of 3D conformal radiation therapy and intensity modulated radiation therapy of the prostate are reduced by aligning the...Full Text Available

2007-07-01

199

14 - NASA  

Science.gov (United States)

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

200

Advanced Lighting Program Development (BG9702800) Final Report  

Energy Technology Data Exchange (ETDEWEB)

The report presents a long-range plan for a broad-based, coordinated research, development and market transformation program for reducing the lighting energy intensities in commercial and residential buildings in California without compromising lighting quality. An effective program to advance lighting energy efficiency in California must be based on an understanding that lighting is a mature field and the lighting industry has developed many specialized products that meet a wide variety of light needs for different building types. Above all else, the lighting field is diverse and there are applications for a wide range of lighting products, systems, and strategies. Given the range of existing lighting solutions, an effective energy efficient lighting research portfolio must be ...

1998-02-01

201

Simulation of self-assembled nanopatterns in strained 2D alloys on the face centered cubic (111) surface  

Energy Technology Data Exchange (ETDEWEB)

We investigate the formation of nanostructures in 2D strained alloys on face centered cubic (111) surfaces by means of equilibrium Monte Carlo simulations. In the framework of an off-lattice model, we consider one monolayer of two bulk-immiscible adsorbates A and B with negative and positive misfit relative to the substrate, respectively. Simulations show that the adsorbates partly self-organize into island or stripe-like patterns. We show how these structures depend on the relative misfits, interaction, and concentration of components. The morphology is quite different for phase separation and intermixing regimes.

2008-07-02

202

MITL - A 2-D code to investigate electron flow through non-uniform field region of magnetically insulated transmission lines  

Science.gov (United States)

Self-magnetically insulated, high-voltage transmission lines are used in inertial confinement fusion particle accelerators in order to transmit power from the vacuum insulator to the diode. This paper describes a time-dependent 2-D code (MITL) for calculating (for planar or triplate geometries) the motion of test electrons through the tapered input or output convolutes of such lines. MITL results show that the electron canonical momentum in the direction of the flow changes as the electron passes through the convoluted geometry; it is suggested that these electrons lead to losses observed in long self-magnetically insulated lines.

1979-01-01

203

A comprehensive, numerical model of electro-thermal propulsion  

Science.gov (United States)

A computer model of an electrothermal accelerator has been developed which applies to the plasma generator as well as the gun barrel, and it for the first time allows study of the interdependent physical processes in both components simultaneously. The code comprises a 2D transient description of the plasma arc, a 2D, two-phase interior ballistics module, and a preprocessor delivering the required plasma physical data. Some results on the flow field, pressure and temperature in a typical accelerator are presented, and probable limitations on the performance of such a system are discussed. The code is to be applied to different concepts of electrothermal chemical guns.

1993-01-01

204

2D Electrostatic Simulation of the Modulated Electron Beam Interaction with Inhomogeneous Plasma  

International Nuclear Information System (INIS)

Electrostatic plasma simulation code for 2D rectangular geometry is presented. Main distinguishing feature of the code is its orientation on the beam-plasma interaction. The code and its graphical interface were developed using MATLAB programming language. Simulation results of inhomogeneous plasma interaction with modulated electron beams of different width are compared. In case of wide beam the front of Langmuir waves generated in point of local plasma resonance is planar and in case of thin beam (or ribbon beam) the front has approximately half-circular form.

2006-01-01

205

Phenomenological study of light-induced effects in #alpha#-Al_2O_3:C  

International Nuclear Information System (INIS)

A computerised glow curve deconvolution (CGCD) analysis was applied to the main dosimetric peak of #alpha#-Al_2O_3:C in order to study the effects of light on the glow curve shape. It was shown that both the light-induced signal and the light-induced fading effects tend to shift the main dosimetric peak to higher temperatures and at the same time change its shape. Furthermore it was confirmed that the magnitude of the light-induced signal depends on radiation history and, by increasing the duration of light exposure, the magnitude of the light-induced signal reaches a plateau, thereby implying the saturation of the phototransfer process. (author).

1995-07-10

206

Lighting in indoor environments: Visual and non-visual effects of light sources with different spectral power distributions  

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

207

Longitudinal light clock and Lorentz distortions  

CERN Document Server

The transverse light clock, in uniform translatory motion, is usually adopted to prove the necessity of the relativistic time dilation, according to the invariance of the velocity of the light, while the former postulate of the Special Relativity is respected by the symmetrical behavior of the clock. In this paper it is instead demonstrated that the behavior of the moving longitudinal light clock must involve unusual Lorentz distortions of the space, travelled by the light, to respect both the postulates of the Special Relativity.

2011-01-01

208

Studies of aerosol formation in power plant plumes - II. Secondary aerosol formation in the Navajo generating station plume  

Energy Technology Data Exchange (ETDEWEB)

Aerosol and gas measurements were made with the University of Minnesota Mobile Laboratory (UMML) during the VISTTA programme near Page, Arizona. The UMML was stationed on Zilnez Mesa approx. 65 km east of the Navajo coal-fired power plant. Measurements were made both in and out of the power plant plume and were made during the day and night. Measured parameters included aerosol size distributions, Aitken nuclei count, ozone and sulphur dioxide concentrations, the aerosol light scattering coefficient, and meteorological parameters including ultraviolet radiation intensity. Concentrations of NO and NO/SUB/x were occasionally measured. Data show clear evidence of gas-to-particle conversion in the plume with aerosol volume being added in the 0.01 MUm - 0.32 MUm dia. range and new particles being formed. The observed excess aerosol volume depends strongly upon the SO/SUB/2 concentrations and the time of day with none observed in plume parcels which ...

1981-01-01

209

Radiological characterization of the GRR-1 pool  

International Nuclear Information System (INIS)

GRR-1 is a 5MW open pool type research reactor with MTR-type fuel elements cooled and moderated by light water with beryllium reflectors at the two opposing sides of the core. A graphite thermal neutron column is adjusted to one side of the core. Six radial horizontal beam tubes are available, of which three contain in-pile collimators for neutron scattering instruments. The reactor is currently out of operation for inspection and refurbishment purposes. The core has been dismantled and the fuel elements are stored in the used fuel storage tank. The GRR-1 inspection and refurbishment plan involves inspection and eventually replacement of the reactor's primary cooling circuit. The health physics procedures to be implemented during inspection of the main water outlet are divided in three stages: a) pool dose rate survey from pool top, b) pool drainage by decreasing water level in steps and c) inspection of the water main outlet. urpose of the ...

2007-11-05

210

Measuring induction period for calcium sulfate dihydrate precipitation  

Energy Technology Data Exchange (ETDEWEB)

Homogeneous nucleation of CaSO{sub 4}{center_dot}2H{sub 2}O (gypsum) based on an optical diagnostic technique was studied within a supersaturation range of 1--4 at 25--90 C. The experiments were carried out using an experimental apparatus consisting of a batch crystallizer with the related measurement devices. Signals of scattered and transmitted light coming from a He-Ne laser source were analyzed to measure the induction period (t{sub ind}), that is, the time delay necessary for homogeneous nucleation to take place. As expected from theory, it was found that t{sub ind} decreases when either temperature or supersaturation increase; from the dependence of t{sub ind} on supersaturation, it was possible to distinguish between the mechanisms of homogeneous and heterogeneous nucleation. From the experimental data relative to homogeneous nucleation, the interfacial tension ({gamma}{sub s}) between CaSO{sub 4}{center_dot}2H{sub 2}O and the ...

1999-02-01

211

Cytotoxic evaluation of N-isopropylacrylamide monomers and temperature-sensitive poly(N-isopropylacrylamide) nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

The objective of this research project is to investigate the biocompatibility of N-isopropylacrylamide (NIPAAm) monomers and poly(N-isopropylacrylamide) (PNIPAAm) nanoparticles in vitro. PNIPAAm nanoparticles of different sizes were synthesized and characterized by transmission electron microscopy and dynamic light scattering. Cytotoxicity studies using MTS assays were conducted on fibroblasts, smooth muscle cells, and endothelial cells. In addition, the concentration of NIPAAm monomers remaining on PNIPAAm nanoparticles was determined using bromination and spectrophotometry. The cytotoxicity results did not show a significant difference in cell survival when cells were exposed to different particle sizes (100, 300, and 500 nm). Dose studies showed that all three cell types exposed to 100 nm PNIPAAm nanoparticles at concentrations less than or equal to 5 mg/mL were compatible, while cells exposed to NIPAAm monomers exhibited toxicity even at ...

2009-08-15

212

Comparative studies on titanium and tantalum oxides thin film structures for laser mirrors, deposited by ion assisted gun  

International Nuclear Information System (INIS)

For obtaining radiation less damagable laser mirrors, a preliminary optimization of film fabrication suitable for the analysis of laser damage mechanism has been done as the first step. Here, the optimization requires not only the stable fabrication process but also the ideal film structure i.e., the amorphous and smooth film structure simultaneously, eliminating latently unwanted secondary effects such as light scattering during laser damage test. For this purpose, we adopted the ion assisted deposition (IAD) method and modified the deposition conditions for titanium and tantalum oxide films, both of which compose typical high index layers, and where SiO_2 layers are also chosen as low index layers because of their amorphous and smooth nature, in alternative multilayer laser mirrors. Surface and cross sectional film structures and film crystallinity are compared and characterized, using a high resolution SEM and a x-ray diffractometer, ...

1996-10-07

213

Assessment of bone formation and bone resorption in osteoporosis: a comparison between tetracycline-based iliac histomorphometry and whole body /sup 85/Sr kinetics  

Energy Technology Data Exchange (ETDEWEB)

Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to measurement imprecision ...

1987-12-01

214

X-ray scattering signatures of {beta}-thalassemia  

Energy Technology Data Exchange (ETDEWEB)

X-ray scattering from lyophilized proteins or protein-rich samples is characterized by the presence of two characteristic broad peaks at scattering angles equivalent to momentum transfer values of 0.27 and 0.6 nm{sup -1}, respectively. These peaks arise from the interference of coherently scattered photons. Once the conformation of a protein is changed, these two peaks reflect such change with considerable sensitivity. The present work examines the possibility of characterizing the most common cause of hemolytic anaemia in Egypt and many Mediterranean countries; {beta}-thalassemia, from its X-ray scattering profile. This disease emerges from a genetic defect causing reduced rate in the synthesis of one of the globin chains that make up hemoglobin. As a result, structurally abnormal hemoglobin molecules are formed. In order to detect such molecular disorder, hemoglobin samples of {beta}-thalassemia ...

2009-08-11

215

Vector Boson Scattering in the Standard Model an Overview of Formulae  

CERN Document Server

Tree-level scattering amplitudes of longitudinally polarized electroweak vector bosons in the Standard Model are calculated using Mathematica package Feyncalc. The modifications of low-energy theorems for longitudinally polarized W and Z in the Standard Model are discussed.

1997-01-01

216

The scattering amplitude for four off-shell tachyons from functional integrals  

International Nuclear Information System (INIS)

We use functional integral techniques to calculate the scattering amplitude for four open off-shell tachyons in Witten's string field theory and show that the residues of the first three poles agree with those obtained using oscillator methods. (orig.).

217

The measurement of polarization in backward scattering for the reactions $\\pi^{+} p \\rightarrow p \\pi^{+},K^{+} p \\rightarrow p K^{+}$ and $\\;\\pi^{+} p \\rightarrow \\Sigma^{+} K^{+}$  

CERN Multimedia

The measurement of polarization in backward scattering for the reactions $\\pi^{+} p \\rightarrow p \\pi^{+},K^{+} p \\rightarrow p K^{+}$ and $\\;\\pi^{+} p \\rightarrow \\Sigma^{+} K^{+}$

2006-01-01

218

Small-Angle X-ray Scattering of Reduced Ribonuclease A: Effects of Solution Conditions and Comparisons with a Computational Model of Unfolded Proteins  

UK PubMed Central (United Kingdom)

The disulfide-reduced form of bovine ribonuclease A (RNAse A), with the Cys thiols irreversibly blocked, was characterized by small-angle x-ray scattering (SAXS). To help resolve the conflicting...Full Text Available

2008-04-11

219

Scattering amplitude for four off-shell tachyons from functional integrals  

Energy Technology Data Exchange (ETDEWEB)

We use functional integral techniques to calculate the scattering amplitude for four open off-shell tachyons in Witten's string field theory and show that the residues of the first three poles agree with those obtained using oscillator methods.

1988-05-30

220

Phonon density of states in V_3Si  

International Nuclear Information System (INIS)

The observation by inelastic neutron scattering techniques of a high energy peak in the phonon spectrum (14 THz) of V_3Si is reported, and is attributed to a peak in the phonon density of states due to vanadium motions by the incoherent inelastic neutron scattering process.

1988-12-01

221

Measurements of accurate x-ray scattering data of protein solutions using small stationary sample cells  

UK PubMed Central (United Kingdom)

In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage...Full Text Available

2009-01-01

222

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

International Nuclear Information System (INIS)

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

224

Duality in Neutrino Reactions  

Energy Technology Data Exchange (ETDEWEB)

On the basis of the phenomenological model for baryon resonance production in lepton nucleon and lepton nucleus scattering we investigate to what extent quark hadron duality is applicable to the neutrino structure functions and how it compares with duality in electron scattering.

2007-12-01

225

A comparison of truncated total least squares with Tikhonov regularization in imaging by ultrasound inverse scattering  

International Nuclear Information System (INIS)

For good image quality using ultrasound inverse scattering, one alternately solves the well-posed forward scattering equation for an estimated total field and the ill-posed inverse scattering equation for the desired object property function. In estimating the total field, error or noise contaminates the coefficients of both matrix and data of the inverse scattering equation. Previous work on ill-posed inverse ultrasonic scattering commonly used Tikhonov regularization, which considers error only in the data. The solution so obtained is not precise enough to reconstruct the quantitative internal structure of a large or high-contrast object. This paper adopts the truncated total least squares method, simultaneously considering error and noise on both sides of the inverse scattering equation, and compares it with the classical Tikhonov regularization. We show that ...

2003-08-07

226

Semi-empirical formula for #LAMBDA#-binding energies in ground states of light hypernuclei  

International Nuclear Information System (INIS)

Starting with a #LAMBDA#-nucleus potential, a semi-empirical formula, which gives a fairly satisfactory account of the ground state #LAMBDA#-binding energy of light hypernuclei, if the very light nuclei are ignored has been obtained. (author).

227

Measurements and elimination of Cherenkov light in fiber-optic scintillating detector for electron beam therapy dosimetry  

International Nuclear Information System (INIS)

In this study, a miniature fiber-optic radiation detector has been developed using a water-equivalent organic scintillator for electron beam therapy dosimetry. Usually, two kinds of light signals such as fluorescent and Cherenkov lights are generated in a fiber-optic radiation detector when a high-energy electron beam is irradiated. The fluorescent light signal is produced in the scintillator and is transmitted through a plastic optical fiber to a remote light-measuring device such as a PMT or a photodiode. The Cherenkov light could be also produced in the plastic optical fiber itself and be detected by a light-measuring device. Therefore, it could cause problems or limit the accuracy of the detection of a fluorescent light signal that is proportional to dose. The objectives of this study are to measure, characterize and eliminate Cherenkov ...

2007-08-21

228

Clinical Efficacy of Self-applied Blue Light Therapy for Mild-to-Moderate Facial Acne  

UK PubMed Central (United Kingdom)

This study was an evaluation of the performance of self-applied, blue light, light-emitting diode therapy in the treatment of mild-to-moderate inflammatory acne on the face, concerning: 1) time to improvement...Full Text Available

2009-03-01

229

Two- and three-phonon states in "8"8Sr  

International Nuclear Information System (INIS)

... de-excitation excited states gamma radiation inelastic scattering mev range

230

The influence of scattered radiation on recording systems and quality-assurance test parameters  

International Nuclear Information System (INIS)

Scattered radiation generated in patient and imaging system has to be considered when quality-assurance tests involve dose detection or image-quality estimations. Measurement of automatic-exposure control dose can be altered by backscattering from intensifying screens of more than 10% and the equipment transmission factor can be overestimated up to a factor of 10 when only primary radiation is used. The sensitivity of intensifying screens depends on the angle of incidence of the radiation and so primary and scattered radiation are detected differently. The quality-control aspects of anti-scatter grids are discussed. (author).

1988-02-23

231

The influence of scattered radiation on recording systems and quality-assurance test parameters  

International Nuclear Information System (INIS)

Scattered radiation generated in patient and imaging system has to be considered when quality-assurance tests involve dose detection or image-quality estimations. Measurement of automatic-exposure control dose can be altered by backscattering from intensifying screens of more than 10% and the equipment transmission factor can be overestimated up to a factor of 10 when only primary radiation is used. The sensitivity of intensifying screens depends on the angle of incidence of the radiation and so primary and scattered radiation are detected differently. The quality-control aspects of anti-scatter grids are discussed. (author).

232
234

Pairing effect in the nucleon transfer processes in quasi-elastic heavy ion scattering  

International Nuclear Information System (INIS)

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

1987-04-14

235

Nuclear structure physics at high resolution  

Energy Technology Data Exchange (ETDEWEB)

Techniques for studying nuclear structure are reviewed. Examples are given of charge density determinations by electron and proton inelastic scattering. (AIP)

1985-04-01

236

Lifetime of 2.734 mev Sr"8"8 level  

International Nuclear Information System (INIS)

... range 01-10 nuclei photons radiation sources recoils resonance scattering

237

Investigation of "8"8Sr by (e,e') and (p,p') reactions  

International Nuclear Information System (INIS)

... bcs theory electron reactions excited states form factors inelastic scattering

238

Inelastic collisions of molecular ions in the injected ion drift tube  

International Nuclear Information System (INIS)

... energy spectra inelastic scattering ion-molecule collisions mass spectrometers

1977-07-27

239

Harmonic oscillator representation in the theory of scattering and nuclear reactions  

Energy Technology Data Exchange (ETDEWEB)

The following questions, concerning the application of the harmonic oscillator representation (HOR) in the theory of scattering and reactions, are discussed: the formulation of the scattering theory in HOR; exact solutions of the free motion Schroedinger equation in HOR; separable expansion of the short range potentials and the calculation of the phase shifts; `isolated states` as generalization of the Wigner-von Neumann bound states embedded in continuum; a nuclear coupled channel problem in HOR; and the description of true three body scattering in HOR. As an illustration the soft dipole mode in the (11)Li nucleus is considered in a frame of the (9)Li+n+n cluster model taking into account three body continuum effects.

1995-01-01

240

Electromagnetic excitations in nuclei: From photon scattering to photo-dissociation  

International Nuclear Information System (INIS)

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

2006-03-20

243

The study of 25 MeV alpha particle elastic scattering from a wide range of targets from "4"4Ca to "9"4Zr  

International Nuclear Information System (INIS)

The elastic scattering angular distributions of 25 MeV alpha particles scattered from "7"3Ge, "8"9Y, "9"0Zr, "9"1Zr"9"4Zr, "9"3Nb, "4"4Ca and "4"5Sc have been measured experimentally, and fitted using a conventional optical model. (author).

244

The influence of stray radiation on image quality  

International Nuclear Information System (INIS)

The present state of knowledge on the influence of stray radiation on image quality and its physical description and quantification is summarized. Experimental results on the influence of physical parameters on the fraction of scattered radiation and the effect of scatter reduction by air gap technique and secondary radiation grids are committed. Open theoretical and practical problems and the limitations of common methods of scatter reduction are pointed out. (author).

245

Investigation of morphology and chemical composition of self-organized semiconductor quantum dots and wires by X-ray scattering  

International Nuclear Information System (INIS)

X-ray scattering methods suitable for the investigation of the morphology and chemical composition of self-organized quantum dots and quantum wires are reviewed. Their application is demonstrated in experimental examples showing that a combination of small angle X-ray scattering with high-resolution X-ray diffraction can reveal both the shape and the chemical composition of the self-organized objects. (author)

2001-09-23

246

Interactions between heavy mesons and Goldstone bosons from chiral dynamics  

Energy Technology Data Exchange (ETDEWEB)

We calculate the S-wave scattering lengths for charmed mesons scattering off Goldstone bosons and explore their quark mass dependence using the chiral perturbation theory up to next-to-leading order as well as a unitarized version of it. The quark mass dependence of all scattering lengths determined in a recent lattice calculation can be reproduced by the unitarized version. We also discuss signals of possible bound states in these observables. (orig.)

2009-05-15

247

Dependence of differential cross sections of 100-150 MeV #alpha#-particle elastic scattering on "4"0Ca on character of nucleon density distribution in nucleus  

International Nuclear Information System (INIS)

A theoretical model is proposed for analyzing elastic scattering of 100-150 MeV #alpha#-particles on intermediate mass nuclei. It is shown that, within the scope of this model accounting for inhomogeneous target-nucleus density, an anomalous growth of differential cross section of elastic scattering in the region of average angles can be explained.

248

Covariance matrices for track fitting with the Kalman filter  

Science.gov (United States)

We present a simple and intuitive derivation of the track parameter covariance matrix due to multiple Coulomb scattering for use in track fitting with the Kalman filter. We derive all the covariance matrix elements for two experimentally relevant track parameterizations (i.e. x and y slopes and intercepts, and direction cosines and intercepts) in the presence of thin scatterers and absence of magnetic fields. We further comment on how to account for thick and/or continuous scattering centers.

1993-06-01

249

Compton scatter tomography and its inversion using a few projections  

Energy Technology Data Exchange (ETDEWEB)

Compton scatter tomography utilizes the electronic collimation characteristics available through the Compton scattering angle-energy correlation to obtain tomographic images. In this work we present particular aspects of the technique, which are relevant to the inverse radiation transport problem of reducing marginal projection data to radial two-phase flow regime maps. The results indicate a viable technique for the tomographic imaging of tow-phase flow using practical source strengths and reasonably few detectors.

1988-01-01

250

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

Energy Technology Data Exchange (ETDEWEB)

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

1990-01-01

251

The Limits of Spacepower  

Science.gov (United States)

... to light-light a laser or directed energy weapon would ... space-based components... .the most likely threats are direct ascent anti-satellite weapons; ...

2001-05-18

252

A Computer Vision System for Inspection of Light Emitting ...  

Science.gov (United States)

... Accession Number : ADD801284. Title : A Computer Vision System for Inspection of Light Emitting Diodes. Descriptive Note : Conference paper,. ...

1986-06-01

253

Digitonin abolishes free 2-deoxy-D-glucose accumulation in isolated rat adipocytes  

Energy Technology Data Exchange (ETDEWEB)

The hypothesis that accumulation against sizable chemical gradients of free (non-phosphorylated) 2-deoxy-D-glucose (2dGlc) in isolated rat adipocytes results from an intracellular compartmentation of free hexose was investigated. Cells exposed to 20 ..mu..g/ml digitonin for 10' demonstrated an increased plasma membrane permeability indexed by increased L-glucose entry rates and cellular (presumably cytosolic) protein and K/sup +/ loss. Functional integrity of intracellular organelles was indicated by the ability of the cells to support ATP-driven /sup 45/Ca/sup 2 +/-uptake. Equilibrium 3-O-methylglucose (3-O-MG, a non-accumulated hexose) levels were unaffected. These data suggest a specific permeabilizing action of digitonin at the plasma membrane having no effect on intracellular organelles or passively distributed solutes. Upon addition of digitonin, free 2dGlc fell from 66.5 +/- 8.9 to 7.4 ...

1986-03-05

254

Mass and charge transfer on various relevant scales in polymer electrolyte fuel cells[Dissertation 16991  

Energy Technology Data Exchange (ETDEWEB)

This dissertation is concerned with the development, experimental diagnostics and mathematical modelling and simulation of polymer electrolyte fuel cells (PEFC). The central themes throughout this thesis are the closely interlinked phenomena of mass and charge transfer. In the face of developing a PEFC system for vehicle propulsion these phenomena are scrutinized on a broad range of relevant scales. Starting from the material related level of the membrane and the gas diffusion layer (GDL) we turn to length scales, where structural features of the cell additionally come into play. These are the scale of flow channels and ribs, the single cell and the cell stack followed by the cell, stack, and system development for an automotive power train. In Chapter 3 selected fundamental material models and properties, respectively, are explored that are crucial for the mathematical modelling and simulation of PEFC, as needed in some succeeding parts of this work. First, established mathematical ...

2007-07-01

255

Zero-motion correlations in high-energy proton elastic scattering on sup 40 Ca with noneikonal nucleon-nucleon amplitude  

Energy Technology Data Exchange (ETDEWEB)

Using a noneikonal expression for the two-body scattering amplitude, consistent with the proton-nucleon scattering data, the cross-section of the 1.04 GeV-proton elastic scattering on {sup 40}Ca is calculated by the Glauber-Sitenko theoretical scheme in the framework of the coherent density fluctuation model (CDFM) as well as of the independent-particle model (IPM). It is shown that the use of the noneikonal amplitude in the CDFM calculations improves the agreement with the experimental data especially at larger scattering angles in contrast to the case of the independent-particle model. To that end a decisive role play the zero-motion flucton correlations taken into account in the CDFM. (orig.).

1990-07-01

256

Zero-motion correlations in high-energy proton elastic scattering on "4"0Ca with noneikonal nucleon-nucleon amplitude  

International Nuclear Information System (INIS)

Using a noneikonal expression for the two-body scattering amplitude, consistent with the proton-nucleon scattering data, the cross-section of the 1.04 GeV-proton elastic scattering on "4"0Ca is calculated by the Glauber-Sitenko theoretical scheme in the framework of the coherent density fluctuation model (CDFM) as well as of the independent-particle model (IPM). It is shown that the use of the noneikonal amplitude in the CDFM calculations improves the agreement with the experimental data especially at larger scattering angles in contrast to the case of the independent-particle model. To that end a decisive role play the zero-motion flucton correlations taken into account in the CDFM. (orig.).

257

Vacancy complex scattering mobility of holes in IR-photoexcited p-type ZnTe  

Energy Technology Data Exchange (ETDEWEB)

Conductivity and Hall effect measurements were made in dark and IR-photoexcited p-type ZnTe samples between 77 and 300 K. Acceptor vacancy complexes of activation energies 0.09-0.1 eV were found to be present in the photoexcited samples. Different possible scattering mobilities were considered for both samples to explain the observed hole mobility. In the photoexcited sample a scattering mobility due to vacancy complexes was suggested for the first time to explain the results. The scattering centres were associated with native vacancy complexes segregated at the dislocations sites. The expression for the complex scattering mobility has been deduced using the curve fitting method to be {mu}{sub C}=(6.6x10{sup -11})T{sup 5} e{sup 725/T}. (orig.).

1990-10-01

258

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

Energy Technology Data Exchange (ETDEWEB)

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

1989-07-01

259

Removal of scattered thermal neutrons using antiscatter grid  

International Nuclear Information System (INIS)

One of the significant factors of neutron radiographic image degradation is scattering blur from the object. A practical method is described to enhance image quality by eliminating the overlapping of scattered thermal neutrons component from the objects in ETRR-2 neutron radiography facility, using aluminum Gd-coated antiscatter grid. The MCNP code was used to determine the optimum grid dimensions that will reduce the scattered thermal neutrons from the object. An experiment was performed to determine the optimum grid height and irradiation time that gives the best image with acceptable geometric unsharpness. Using the MCNP code it was found that 97% of the scattered neutrons were removed by the grid. The wall dimensions and Gd coating are so small that the facility resolution cannot detect the image pattern superposition on the film.

2006-12-01

260

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

Energy Technology Data Exchange (ETDEWEB)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be extremely weak and higher S/N of {approx}10{sup 4} or more is required to detect the ...

2009-02-21

261

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

International Nuclear Information System (INIS)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be extremely weak and higher S/N of ?104 or more is required to detect the magnetic ...

2009-02-21

262

Collisions between H"+ and H_2 at kilo-electron-volt energies: Absolute differential cross sections for small-angle direct, single-, and double-charge-transfer scattering  

International Nuclear Information System (INIS)

Measurements of absolute differential cross sections for H"+-H_2 direct, single-, and double-charge-transfer scattering at 0.5, 1.5, and 5.0 keV are reported at laboratory scattering angles less than 1 degree with an angular resolution of approximately 0.02 degree. The cross sections exhibit deep interference oscillations in single-charge-transfer scattering, but no such oscillations are present in direct and double-charge-transfer scattering. Theoretical cross sections derived using the diatoms-in-molecules method to describe the molecular states in a semiclassical molecular-orbital three-state close-coupling model within a semiclassical framework agree satisfactorily with the experimental results.

263

Two dimensional power spectral density measurements of X-rayoptics with the Micromap interferometric microscope  

Energy Technology Data Exchange (ETDEWEB)

A procedure and software have been developed to transform the area distribution of the residual surface heights available from the measurement with the Micromap interferometric microscope into a two-dimensional (2D) power spectral density (PSD) distribution of the surface height. The procedure incorporates correction of one of the spectral distortions of the PSD measurement. The distortion appears as a shape difference between the tangential and sagittal PSD spectra deduced from the 2D PSD distribution for an isotropic surface. A detailed investigation of the origin of the anisotropy was performed, and a mathematical model was developed and used to correct the distortion. The correction employs a modulation transfer function (MTF) of the detector deduced analytically based on an experimentally confirmed assumption about the origin of the anisotropy due to the asymmetry of the read-out process of the ...

2005-05-12

264

Theoretical electron-positron zone-reduced momentum density for YBa_2Cu_3O_7: Fermi surface and wave-function effects  

International Nuclear Information System (INIS)

Using the linearized augmented-plane-wave (LAPW) -calculated electron and positron charge densities for YBa_2Cu_3O_7, the Brillouin-zone-reduced electron-positron momentum density is computed and the zone-reduced two-dimensional angular correlation of annihilation radiation (2D ACAR) spectrum is produced. The calculations show that the relative weights of the Fermi-surface discontinuities are substantially altered due to the positron preferentially sampling the Cu-O chain region. In addition, the reduced 2D ACAR spectrum contains large k-dependent wave-function effects. The theoretical zone-reduced 2D ACAR spectrum is compared to the several existing experimental spectra. It is concluded that, at present, positron-annihilation experiments do not provide consistent and clear evidence for the existence and shapes of Fermi surfaces in YBa_2Cu_3O_7.

265

Spiral Waves and Shocks in Discs around Black Holes: Low Compressibility and High Compressibility models  

Science.gov (United States)

Some authors have concluded that spiral structures and shocks do not develop if an adiabatic index gamma > 1.16 is adopted in accretion disc modelling, whilst others have claimed that they obtained well defined spirals and shocks adopting a gamma = 1.2 and a M_2/M_1 = 1 stellar mass ratio. In our opinion, it should be possible to develop spiral structures for low compressibility gas accretion discs if the primary component is a black hole. We considered a primary black hole of 8 solar mass and a small secondary component of 0.5 solar mass to favour spiral structures formations and possible spiral shocks via gas compression due to a strong gravitational attraction. We performed two 3D SPH simulations and two 2D SPH simulations and characterized a low compressibility model and a high compressibility model for each couple of simulations. 2D models reveal spiral structures existence. Moreover, spiral ...

2001-12-01

266

Spiral Structures and Shocks in Accretion Discs in Close Binary Systems: the Role of the Stellar Mass Ratio.  

Science.gov (United States)

% In this work we investigated, in the Smooth Particle Hydrodynamics (SPH) framework, the development of spiral structures and shock fronts in the radial flow of accretion discs in close binary systems. These shock waves take place when the initially supersonic radial flow penetrating the disc bulk, reduces substantially its speed becoming suddenly subsonic. To this purpose, keeping constant the mass of the compact primary (M1 = 1 MO ), the separation between the two components and the injection speed at the inner Lagrangian point L1 (close to the local sound speed), we carried out 2D SPH simulations for four values of the stellar mass ratio M2/M1. We worked out 2D models because the damping effect of the artificial viscosity is too strong in 3D. Furthermore, the 2D environment seems the most suitable in order to evidence shock fronts in highly compressible ...

2000-06-01

267

Nuclear magnetic resonance spectroscopy in the structure elucidation and biosynthesis of natural products  

Energy Technology Data Exchange (ETDEWEB)

Examination of a chloroform extract of Dracaena loureiri Gagnep (Agavaceae), a Thia medicinal plant possessing antibacterial activity, has led to the isolation of fifteen flavenoids. The biogenic relationships among these flavenoids isolated were briefly discussed. Definition of the skeleton and the unambiguous assignment of all of the protons of the isolates was achieved through extensive 2D-homonuclear chemical shift correlation, nuclear Overhauser effect (NOE) difference spectroscopy and 2D-NOE experiments. The {sup 1}H and {sup 13}C NMR spectra of staurosporine, a potent biologically active agent from Streptomyces staurosporeus, were unambiguously assigned by using 2D homonuclear chemical shift correlation, NOE, {sup 1}H-detected heteronuclear multiple-quantum coherence via direct coupling and via multiple-bond coupling for resonance assignments of ...

1988-01-01

268

Inhibitory effect of minocycline on osteoclastogenesis in mouse bone marrow cells  

British Library Electronic Table of Contents (United Kingdom)

Objective: To study the effects of minocycline hydrochloride (MINO) on the formation of tartrate-resistant acid phosphatase (TRAP) staining-positive multinucleated osteoclast-like cells in mouse bone marrow cells (BMCs) treated with 1@a,25(OH)"2D"3 or soluble receptor activator of nuclear factor-@kB ligand (s-RANKL). Materials and methods: Mouse BMCs were cultured in alpha-modified minimum essential medium containing foetal calf serum (10%) and tetracyclines (2.5, 5 and 10@mM), such as MINO, tetracycline hydrochloride (TC), oxytetracycline hydrochloride (OXT) or doxycycline (DOXY) in the presence of 1@a,25(OH)"2D"3 (10nM) or s-RANKL (20ng/ml) for 7 days, and the number of TRAP staining-positive osteoclast-like cells was counted. In RNA isolated from BMCs treated with 1@a,25(OH)"2D"3 or s-R...

2011-01-01

269

Exploring the 2D to 3D dimensionality crossover in thin iron films  

Energy Technology Data Exchange (ETDEWEB)

The temperature dependence of the spontaneous magnetization of epitaxial iron films with a thickness ranging from d=20 to 200nm has been measured. The films are grown on GaAs (100) substrates which are covered by a 150nm thick silver (100) buffer layer. For three-dimensional BCC iron it was observed already in 1929 that saturation of the spontaneous magnetization for T->0 is perfectly described by a T{sup 2} power law. On the other hand, for thin two-dimensional (2D) iron films a T{sup 3/2} law has been established in many recent experimental investigations. In our iron films grown on diamagnetic silver, this dimensionality change occurs at a thickness between d=100 and 200nm. Comparison of the here-observed T{sup 3/2} coefficients with those on iron films grown on paramagnetic tungsten (110) shows that the 2D interactions are {approx}20 times larger in the films on tungsten. Recent results on Fe ...

2006-05-15

270

Core reactor calculation using the adaptive remeshing with a current error estimator  

International Nuclear Information System (INIS)

With the objective to improve the reactor physics calculation on a 2D and 3D nuclear reactor via the Diffusion Equation, an adaptive automatic finite element remeshing method, based on the elementary area (2D) or volume (3D) constraints, has been developed. The adaptive remeshing technique, guided by a posteriori error estimator, makes use of two external mesh generator programs: Triangle and TetGen. The use of these free external finite element mesh generators and an adaptive remeshing technique based on the current field continuity show that they are powerful tools to improve the neutron flux distribution calculation and by consequence the power solution of the reactor core even though they have a minor influence on the critical coefficient of the calculated reactor core examples. Two numerical examples are presented: the 2D IAEA reactor core numerical ...

271

Computational models of stellar collapse and core-collapse supernovae  

International Nuclear Information System (INIS)

Core-collapse supernovae are among Nature's most energetic events. They mark the end of massive star evolution and pollute the interstellar medium with the life-enabling ashes of thermonuclear burning. Despite their importance for the evolution of galaxies and life in the universe, the details of the core-collapse supernova explosion mechanism remain in the dark and pose a daunting computational challenge. We outline the multi-dimensional, multi-scale, and multi-physics nature of the core-collapse supernova problem and discuss computational strategies and requirements for its solution. Specifically, we highlight the axisymmetric (2D) radiation-MHD code VULCAN/2D and present results obtained from the first full-2D angle-dependent neutrino radiation-hydrodynamics simulations of the post-core-bounce supernova evolution. We then go on to discuss the new code Zelmani ...

2009-07-01

272

Scatter measurements for optical cone-beam computed tomography  

Energy Technology Data Exchange (ETDEWEB)

Both x-ray and optical cone-beam CT (CBCT) scanners are limited by scattered photons that contaminate the primary images. Transparent radiochromic gels and plastics are anticipated to produce less scattering than polymerization gels and hence result in reconstructed dose distributions with greater contrast and dynamic range. Four methods of scatter measurement were investigated to quantify scatter fractions using an in-house optical CBCT scanner. The methods consisted of generating either 'coin' shadows or primary beamlets in transmission images. The four methods generated similar results of 10% scatter fractions in gel transmission images for this particular scanner configuration with both leuco crystal violet and carbon black micelle gels. The scatter contributions were distributed as 5% from micelle gel, 2% from Teflon wall, 2% from ...

2009-05-01

273

Determination of size distribution of Guinier-Preston zones in Al-Ag alloys by small-angle x-ray scattering method  

International Nuclear Information System (INIS)

Small-angle X-ray scattering method recognised to be very useful in the studies of structural problems of materials in homogeneous in nanoscale. Studies by small-angle X-ray scattering on the Al-Ag alloys are presented. The size distributions of spherical Guinier-Person zones were calculated using Vonk's and Glatter's methods. Small-angle X-ray scattering studies were performed on Al-5.0 at.%Ag alloy containing Guinier-Preson zones in the #eta#-state. For this alloy one can assume that scattering particles are of spherical shape, have uniform electron density and scatter independently. Moreover, the size distributions were calculated for Al-1.6 at.%Ag alloy containing Guinier-Preston zones in #epsilon#-state (scattering particles with not uniform electron density). Both, Vonk's and Glatter's, methods gave similar size distributions. Profiles of size ...

2001-09-23

274

Studies of human mutation rates  

Energy Technology Data Exchange (ETDEWEB)

November 1989, marked the beginning of a new three-year cycle of DOE grant support, in connection with which the program underwent a major reorganization. This document presents the progress on the three objectives of the present program which are: to isolate by the technique of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), proteins of special interest because of the relative mutability of the corresponding gene, establish the identity of the protein, and, for selected proteins, move to a characterization of the corresponding gene; to develop a more efficient approach, based on 2-D PAGE, for the detection of variants in DNA, with special reference to the identification of mutations in the parents of the individual whose DNA is being examined; and, to continue an effective interface with the genetic studies on the children of atomic bomb survivors in Japan, with reference to both the ...

1990-01-01

275

Strings through the Microscope  

CERN Document Server

Over the last few years, string theory has changed profoundly. Most importantly, novel duality relations have emerged which involve gauge theories of brane excitations on one side and various closed string backgrounds on the other. In this lecture, we introduce the fundamental ingredients of modern string theory and explain how they are modeled through 2D (boundary) conformal field theory. This so-called `microscopic description' of strings and branes is an active research area with new results ranging from the classification and construction of boundary conditions to studies of 2D renormalization group flows. We shall provide an overview of such developments before concluding the lecture with an extensive outlook on some research that is motivated by current problems in string theory. This includes investigations of non-rational and non-unitary conformal field theories.

2004-01-01

276

Small hemielliptic dielectric lens antenna analysis in 2-D: boundary integral equations versus geometrical and physical optics  

CERN Document Server

We assess the accuracy and relevance of the numerical algorithms based on the principles of Geometrical Optics (GO) and Physical Optics (PO) in the analysis of reduced-size homogeneous dielectric lenses prone to behave as open resonators. As a benchmark solution, we use the Muller boundary integral equations discretized with trigonometric Galerkin scheme that has guaranteed and fast convergence as well as controllable accuracy. The lens cross-section is chosen typical for practical applications, namely an extended hemiellipse whose eccentricity satisfies the GO focusing condition. The analysis concerns homogeneous lenses made of rexolite, fused quartz, and silicon with the size varying between 3 and 20 wavelengths in free space. We consider the 2-D case with both E- and H-polarized plane waves under normal and oblique incidence, and compare characteristics of the near fields.

2010-01-01

277

On the evolution of supernova remnants: Pt. 2  

International Nuclear Information System (INIS)

Supernova explosions within wind-driven bubbles are studied with 2D hydrodynamical calculations. Two different density distributions for the ejecta are considered: (i) a smooth, unfragmented power-law stratification, and (ii) a fragmented distribution. As in 1D models, the presence of the shell of interstellar swept-up matter causes the rapid evolution of the remnant to the radiative phase. The main 2D effects, for both fragmented and unfragmented ejecta, include: (i) substantial chaotic deviations from a purely radial flow in the remnant interior, (ii) efficient turbulent mixing between the ejecta and the shocked wind, resulting in homogenization of the former wind cavity, and (iii) severe distortion of the wind-driven shell by cooling and Rayleigh-Taylor instabilities. (author).

278

Mutual interactions of two planetary objects in a protoplanetary accretion disc: 2D SPH simulations .  

Science.gov (United States)

We present here a study based on the migration of protoplanets in an accretion disc of a forming star, as the mainly proposed scenario for the formation of planetary systems. Attention is here focused on the mutual interactions between two protoplanets, both embedded in the accretion disc, as a function of the protoplanets masses, their relative positions, the dynamic properties of the accretion disc particles. The study is performed through a 2D SPH code and preliminary results show an oscillation of the distance between the two protoplanets, together with a slow migration of the two planets towards the central star when two Jupiter-like planets are considered. Less correlated behaviour is observed when at least one of the two protoplanets has an Earth-like mass. The role played by the disc particles initial angular momentum is discussed.

2010-01-01

279

Mass-loss in 2D zero-age main-sequence stellar models  

British Library Electronic Table of Contents (United Kingdom)

Abstract A large number of massive stars are known to rotate rapidly, resulting in a significant distortion and variation in surface temperature from the pole to the equator. Radiatively driven mass-loss is temperature-dependent, so rapid rotation produces a variation in the mass-loss and angular momentum loss rates across the surface of the star, which is expected to affect the evolution of rapidly rotating massive stars. In this work, we use zero-age main-sequence (ZAMS) stellar models to investigate the two-dimensional effects of rotation on stellar mass-loss, using two common prescriptions for radiatively driven mass-loss. The associated loss of angular momentum from these models is also considered. Using 2D stellar models, which give the variation in surface parameters as a function o...

2011-01-01

280

First trimester measurements of nasal bone length using three-dimensional ultrasound  

British Library Electronic Table of Contents (United Kingdom)

Objectives To investigate the feasibility and reproducibility of measurements of nasal bone length using a three-dimensional (3D) ultrasound in the first trimester. Methods In a prospective study, 118 consecutive pregnant women attending for Down syndrome screening at 11-13 + 6 weeks were recruited. They had successful fetal nasal bone measurement by two-dimensional (2D) ultrasound by four operators. Three-dimensional volumes were recorded in the mid-sagittal plane of fetal profile by the fifth operator and examined using multiplanar techniques. Another independent investigator randomly compared his measurements with one of the four operators. Results In the subsequent 3D examination, the nasal bone length could be examined in 94 cases (79.7%). The mean difference between the 2D and 3D mea...

2009-01-01

281

Exploring the potential energy surface for proton transfer in acetylacetone  

Energy Technology Data Exchange (ETDEWEB)

The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecular proton transfer reaction is studied using ab initio and DFT methods. The best estimate of the barrier governing proton transfer was found to be 3.4 kcal mol{sup -1} at the MP4(FC)/6-311 + G(2d,2p)//MP2(FC)/6-311 + G(2d,2p) level of theory. Six stationary points on the PES were characterized as well as the reaction paths connecting these points. Special attention paid to the pathway of intramolecular proton transfer reveals that the internal rotation of the methyl group adjacent to the carbonyl group and the proton transfer reaction are consecutive processes.

2004-11-15

282

Discretization of complex 3-D flow domains with adaptive hybrid grids  

Energy Technology Data Exchange (ETDEWEB)

There is an ever increasing demand to perform flow simulations that incorporate the complete details of geometry as well as sophisticated flow physics. This has led to the development of numerical algorithms that can simulate the actual flow phenomena with greater fidelity. However, the success of these algorithms hinges on the grid that models the geometry. Grid generation methods for 2-D models have long existed and the general lack of complexity of the simpler 2-D models has not quite challenged the efforts in this area. However, demands for generating better 3-D geometric models for flow simulations involving complex geometries have completely changed the perspective of grid generation strategies. As a consequence, grid generation efforts have earned equal significance as that of numerical solver efforts.

1996-12-31

283

A Detector for 2-D Neutron Imaging for the Spallation Neutron Source  

Energy Technology Data Exchange (ETDEWEB)

Abstract - We have designed, built, and tested a 2-D pixellated thermal neutron detector. The detector is modeled after the MicroMegas-type structure previously published for collider-type experiments. The detector consists of a 4X4 square array of 1 cm 2 pixels each of which is connected to an individual preamplifier-shaper-data acquisition system. The neutron converter is a 10B film on an aluminum substrate. We describe the construction of the detector and the test results utilizing 252Cf sources in Lucite to thermalize the neutrons.Drift electrode (Aluminum) Converter (10B) 3 mm Conversion gap neutron (-900 V)

2006-07-01

284

2D SPH simulations of a single planet migration in a protoplanetary disc  

Science.gov (United States)

Migration of protoplanets inside an accretion disc of a forming star is the most probable scenario for planetary system formation according to current models. Unsolved problems exist, concerning migration times and mechanisms. We report here the results of a 2D hydrodynamic study within an SPH scheme, analysing migration of an Earth-like or a Jupiter-like planet inside an inviscid sub-Keplerian accretion disc, as a function of the initial specific angular momentum of the infalling accretion disc matter. Particle capture by the protoplanet causes a rapid migration, within a few orbits, for the Earth like planet, and about 104 orbits for the Jupiter like planets. The effect of a planet pseudo-atmosphere is also discussed.

2010-01-01

286

Stored light and released fiction  

CERN Document Server

It is shown that the interpretation of the experimental results reported in the publication "Storage of Light in Atomic Vapor" by D.F.Phillips et al., Phys. Rev.Lett. 86, 783 (2001) [quant-ph/0012138] is incorrect. The experimental observation of this paper can be consistently explained in the framework of standard concepts of the physics of optical pumping and has nothing to do with "storage of light", or "dynamic reduction of the group velocity", or "light pulse compression".

2003-01-01

288

Shedding Synchrotron Light on a Puzzle of Glasses  

ScienceCinema

...introduced english ...the range of simple english ...the range of simple english ...

289

STS-134: Go for Launch  

National Aeronautics and Space Administration (NASA)

Endeavour is given the green light after all prelaunch

2011-05-16

290

Radiation hardening of optical fiber links by photobleaching with light of shorter wavelength  

International Nuclear Information System (INIS)

The influence of additionally injected short-wavelength photobleaching light on the radiation hardness of Ge-doped graded index fibers working at 1,300 nm wavelength is investigated. Predictions are complicated by the fact that more efficient shortwave bleaching light experiences higher radiation-induced loss. Promising results are found for low fiber temperatures (approx-lt -50 C) and bleaching light of about 835 nm wavelength.

1995-09-18

293

Heavy and light quarks in the instanton vacuum  

CERN Document Server

Assuming the gluon field is well approximated by instanton configurations we derive a light quarks determinant and calculate its contribution to the specific heavy quarks correlators -- namely, the heavy quark propagator and heavy quark-aniquark correlator, receiving the instanton generated light-heavy quarks interaction terms contributions. With these knowledge we calculate the light quark contribution to the interaction between heavy quarks, which might be essential for the properties of a few heavy quarks systems.

2011-01-01

297

BOOKMARKS:  

Wastenet

Institutional and organizational models ... Review individual centre institutional and organizational models in the light of the tasks to be

298

BC  

Wastenet

Institutional and organizational models ... Review individual centre institutional and organizational models in the light of the tasks to be performed by

299

Vacuum structures in Hamiltonian light-front dynamics  

Energy Technology Data Exchange (ETDEWEB)

Hamiltonian light-front dynamics of quantum fields may provide a useful approach to systematic nonperturbative approximations to quantum field theories. The authors investigate inequivalent Hilbert-space representations of the light-front field algebra in which the stability group of the light front is implemented by unitary transformations. The Hilbert space representation of states is generated by the operator algebra from the vacuum state. There is a large class of vacuum states besides the Fock vacuum which meets all the invariance requirements. The light-front Hamiltonian must annihilate the vacuum and have a positive spectrum. Relations are exhibited of the Hamiltonian to the nontrivial vacuum structure. 30 refs.

1994-03-01

300

Self-seeded injection-locked FEL amplifier  

Energy Technology Data Exchange (ETDEWEB)

A self-seeded free electron laser (FEL) provides a high gain and extraction efficiency for the emitted light. An accelerator outputs a beam of electron pulses to a permanent magnet wiggler having an input end for receiving the electron pulses and an output end for outputting light and the electron pulses. An optical feedback loop collects low power light in a small signal gain regime at the output end of said wiggler and returns the low power light to the input end of the wiggler while outputting high power light in a high signal gain regime.

1998-12-01

301

Revisiting light neutralino scenarios in the MSSM  

CERN Document Server

We revisit the case of a light neutralino LSP in the framework of the MSSM. We consider a model with eleven free parameters. We show that all scenarios where the annihilation of light neutralinos rely mainly on the exchange of a light pseudoscalar are excluded by direct detection searches and by Fermi measurements of the gamma-flux from dwarf spheroidal galaxies. On the other hand, we find scenarios with light sleptons that satisfy all collider and astroparticle physics constraints. In this case, the lower limit on the LSP mass is 12.6 GeV. We discuss how the parameter space of the model will be further probed by new physics searches at the LHC.

2011-01-01

302

Gravitational Waves and the Sagnac Effect  

CERN Document Server

We consider light waves propagating clockwise and other light waves propagating counterclockwise around a closed path in a plane (theoretically with the help of stationary mirrors). The time difference between the two light propagating path orientations constitutes the Sagnac effect. The general relativistic expression for the Sagnac effect is discussed. It is shown that a gravitational wave incident to the light beams at an arbitrary angle will not induce a Sagnac effect so long as the wave length of the weak gravitational wave is long on the length scale of the closed light beam paths. The gravitational wave induced Sagnac effect is thereby null.

2003-01-01

303

Laser: a Tool for Optimization and Enhancement of Analytical Methods  

Energy Technology Data Exchange (ETDEWEB)

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

1997-01-01

304

Aerosol Properties Over the United Arab Emirates and Arabian Gulf from MISR Multi-angle Satellite Imaging  

Science.gov (United States)

The MISR instrument aboard NASA's Terra satellite participated in the UAE-2 campaign, August-October 2004. This campaign represented a unique opportunity to study the complex aerosol situation in the Arabian Gulf region, in the context of a first-rate collection of aircraft and surface-based instruments, giving us the opportunity to do some groundbreaking satellite aerosol validation work. We aimed (1) to validate MISR aerosol retrieval results for dust and pollution particles over dark and light surfaces, and (2) to contribute regional maps of aerosol optical thickness (AOT) and particle micro-physical properties, giving spatial context to the field-instrument measurements, and moving toward a satellite-based regional aerosol climatology. The validation effort benefited from the combination of an instrumented aircraft and a regional network of surface-based sun photometers. We obtained high-quality sub-orbital data coincident with MISR overpasses on three days: ...

2005-12-01

305

Vertex operator representation of OS/sub rho/(M/N)/sup (1)/  

Energy Technology Data Exchange (ETDEWEB)

Using the boson-fermion equivalence in 2-d conformal field theory and the boson-boson equivalence of the superconformal bosonic ghost fields of the string theory, the authors construct a level {Kappa} = +1 representation of the affine superalgebra OSp(M*N)/sup 1/ in terms of vertex operators.

1988-01-01

306

Two dimensional analysis for equilibrium core of CANDU-PHWR  

Energy Technology Data Exchange (ETDEWEB)

The WBURN (2-D, 2-group, coarse mesh) code is developed to analyze the equilibrium core characteristics of CANDU-PHWR. The equilibrium characteristics of Wolsung reactor computed by using WBURN are compared with the values given in the Wolsung FSR. The changes of equilibrium core characteristics caused by the variation of design parameters for operating conditions are also investigated. The numerical results indicate that the average discharge irradiation in the Wolsung reactor can be increased up to about 5%.

1983-06-01

307

Two dimensional analysis for equilibrium core of CANDU-PHWR  

International Nuclear Information System (INIS)

The WBURN (2-D, 2-group, coarse mesh) code is developed to analyze the equilibrium core characteristics of CANDU-PHWR. The equilibrium characteristics of Wolsung reactor computed by using WBURN are compared with the values given in the Wolsung FSR. The changes of equilibrium core characteristics caused by the variation of design parameters for operating conditions are also investigated. The numerical results indicate that the average discharge irradiation in the Wolsung reactor can be increased up to about 5%. (Author).

1983-01-01

308

The rare earth antimonates: spectroscopic properties, crystal field and paramagnetic susceptibility simulations  

International Nuclear Information System (INIS)

The rare earth antimonates RE_3Sb_5O_1_2 constitute an isostructural series, where the rare earth site symmetry is S_4. The spectroscopic properties of pure or doped compounds of this family are studied in order to derive their energy level schemes and to simulate them through the crystal field theory, by using the approximated D_2_d potential. The paramagnetic susceptibilities are calculated with the derived wavefunctions and compared to experiment.

1990-09-01

309

The effects of spatial location of defect states on the switching characteristics of amorphous and polycrystalline silicon thin film transistors: A numerical simulation using AMPS 2-D  

Energy Technology Data Exchange (ETDEWEB)

We demonstrate a two-dimensional device simulator for MOSFET structures that incorporates models for defect distributions and show predicted effects on device switching performance for various spatial distributions of defects in amorphous and polycrystalline silicon.

1994-06-01

310

Supersonic flutter of composite sandwich panels  

Science.gov (United States)

A flutter-motion equation is presently derived for a 2D composite sandwich panel considering the total lateral displacement of the plate as the sum of the displacement due to bending of the plate, and that which is due to shear deformation at the core. The effects of core thickness and stacking sequence of the faces on the flutter boundary of the plate are discussed; it is shown that the sandwich panel greatly improves the flutter boundary over that of a composite laminate panel, provided it has sufficient core thickness.

1992-12-01

311

Spiral Structures and Shocks in Accretion Discs in Close Binary Systems: the Role of the Injection Velocity at the Inner Lagrangian Point  

Science.gov (United States)

In our previous paper (Lanzafame et al. 2000, PASJ 52, 515) we showed, through 2D SPH simulations, that the stellar mass ratio, M 2 / M 1, of a close binary system (that determines the position and then the initial specific angular momentum at L 1) plays a fundamental role in the formation and development of spiral structures and shock fronts in the radial flow of accretion discs. In that work only a quasi-sonic value of the injection velocity at L 1 was considered. In the present work we also carried out 2D SPH simulations with the aim to investigate the development of such structures, while keeping constant the mass of the compact primary (M 1 = 1 M odot) and the separation between the two components, and assuming as an initial condition of two different supersonic injection velocities at L 1, characterizing two sets of simulations. For each set we considered four values of the secondary to primary ...

2001-02-01

312

Simulation aided hardening of N-channel power MOSFETs to prevent single event burnout  

International Nuclear Information System (INIS)

2D MEDICI simulator is used to investigate hardening solutions to single-event burnout (SEB). SEB parametric dependencies such as carrier lifetime reduction, base enlargement, and emitter doping decrease have been verified and a p"+ plug modification approach for SEB hardening of power MOSFETs is validated with simulations on actual device structures.

1995-07-17

313

Isomerization of 1-O-Indol-3-Ylacetyl-?-d-Glucose 1  

UK PubMed Central (United Kingdom)

The first compound in the series of reactions leading to the ester conjugates of indole-3-acetic acid (IAA) in kernels of Zea mays sweet corn is the acyl alkyl acetal, 1-O-indol-3-ylacetyl-;2;-d-glucose...Full Text Available

1990-09-01

314

Interventional Procedures in Superficial Lesions: The Value of 2D with Additional Coronal Reformatted 4D Ultrasonography Guidance  

UK PubMed Central (United Kingdom)

ObjectiveWe wanted to assess the usefulness of four-dimensional (4D) ultrasonography (US), i.e., real-time three-dimensional US, as an adjunct for performing various US-guided interventional...Full Text Available

2006-01-01

315

Increased levels of the calcification marker Matrix Gla Protein and the inflammatory markers YKL-40 and CRP in patients with type 2 diabetes and ischemic heart disease  

UK PubMed Central (United Kingdom)

Objective and designLow grade inflammation is of pathogenic importance in atherosclerosis and in the development of cardiovascular disease (CVD) and type 2 diabetes (T2D). Matrix...Full Text Available

316

Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system  

Energy Technology Data Exchange (ETDEWEB)

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of /sup 203/Pb and /sup 47/Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol (1,25(OH)/sub 2/D/sub 3/) as their only source of the vitamin, the absorption of both /sup 47/Ca and /sup 203/Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in /sup 47/Ca and /sup 203/Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with 1,25(OH)/sub ...

1984-04-01

317

Gastrointestinal absorption of lead in chicks: involvement of the cholecalciferol endocrine system  

International Nuclear Information System (INIS)

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of "2"0"3Pb and "4"7Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol [1,25(OH)_2D_3] as their only source of the vitamin, the absorption of both "4"7Ca and "2"0"3Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in "4"7Ca and "2"0"3Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with ...

318

Enzymic Synthesis of Indole-3-Acetyl-1-O-?-d-Glucose 1  

UK PubMed Central (United Kingdom)

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-;2;-d-glucose...Full Text Available

1988-12-01

319

Dietary calcium and magnesium intakes and the risk of type 2 diabetes: the Shanghai Women's Health Study123  

UK PubMed Central (United Kingdom)

Background: Diet plays a key role in the development of type 2 diabetes (T2D), but little is known about the contributions of specific nutrients in populations in which dietary patterns...Full Text Available

2009-04-01

320

Development on the cryogenic hydrogen isotopes distillation process technology for tritium removal (Final report)  

Energy Technology Data Exchange (ETDEWEB)

While tritium exposure to the site-workers in Wolsung NPP is up to about 40% of the total personnel exposure, Ministry of Science and Technology has asked tritium removal facility for requirement of post heavy-water reactor construction. For the purpose of essential removal of tritium from the Wolsung heavy-water reactor system, a preliminary study on the cryogenic Ar-N{sub 2} and H{sub 2}-D{sub 2} distillation process for development of liquid-phase catalytic exchange cryogenic hydrogen distillation process technology. The Ar-N{sub 2} distillation column showed good performance with approximately 97% of final Ar concentration, and a computer simulation code was modified using these data. A simulation code developed for cryogenic hydrogen isotopes (H{sub 2}, HD, D{sub 2}, HT, DT, T{sub 2}) distillation column showed good performance after comparison with the result of a JAERI code, and a H{sub 2}-D{sub ...

1995-12-01

321

Development of 2-D velocity structure model input tool  

Energy Technology Data Exchange (ETDEWEB)

The seismic reflection exploration technique which is one of the geophysical methods for oil exploration became effectively to image the subsurface structure with rapid development of computer. As a tool to perform seismic inversion, seismic forward modeling program using ray tracing should be developed. In this study, we have developed the algorithm that is to calculate the travel time of the complex geological structure using ray tracing by subdividing the geologic model into triangular element (finite element) having the constant velocity. We can analytically calculate Jacobian with some information by this current ray tracing. With this Jacobian, we will develop new algorithm which is to obtain geological properties and to image the subsurface. Since the FEM (Finite Element Method) ray tracing we have developed goes well the inverse velocities structure, we can apply the inversion problem to complex geological model. For the convenience of velocity model input data which is needed ...

1996-12-01

322

Computer simulation and radiation hardening of power devices to protect against failures induced by heavy ions  

International Nuclear Information System (INIS)

Power devices such as MOSFETSs and IGBTs, include parasitic structures that can give rise to destructive failures such as breakdown and latch-up. To determine a suitable strategy for device radiation hardening, simulation software like MEDICI-2D can be used to model the effects of technological modifications and device parameters that are difficult to measure experimentally. (authors).

323

Besarhanamides A and B from the marine cyanobacterium Lyngbya majuscula  

British Library Electronic Table of Contents (United Kingdom)

Besarhanamides A (1) and B (2) are fatty acid amides purified from the marine cyanobacterium, Lyngbya majuscula, collected from Pulau Hantu, Singapore. The structure determination of these secondary metabolites was carried out using extensive 2D NMR spectral data as well as chemical manipulations including the Marfey's method. In addition, besarhanamide A exhibited moderate toxicity with LD50 at 13mM in the brine shrimp toxicity bioassay.

2008-01-01

324

BACCHUS: A numerical approach to two-phase flow in a rod bundle  

Energy Technology Data Exchange (ETDEWEB)

We present in this paper the computer code BACCHUS, to analyze the thermal-hydraulics in a rod bundle in single or two-phase flow regime. The model is 2-D and uses the porous body approach. The two-phase model is an extension of the classical homogeneous model, and includes a differential non-equilibrium equation. Results are shown for the extension of the boiling region in a 19-pin bundle.

1984-10-01

325

BACCHUS: A numerical approach to two-phase flow in a rod bundle  

International Nuclear Information System (INIS)

We present in this paper the computer code BACCHUS, to analyze the thermal-hydraulics in a rod bundle in single or two-phase flow regime. The model is 2-D and uses the porous body approach. The two-phase model is an extension of the classical homogeneous model, and includes a differential non-equilibrium equation. Results are shown for the extension of the boiling region in a 19-pin bundle. (orig.).

1984-01-01

326

Application of river basin simulation for flood hazard assessment  

Energy Technology Data Exchange (ETDEWEB)

2D simulation modeling of a river basin is based on notion of a River Basin as an opened non equilibrium nature system. All components of the system (elevation, water, soil properties and others) are linked to single multi - functional model. The objective of flood simulation is one the model functions. The objectives of the paper are as follows: a mean scale basin floods computing and the model validation; a large scale basin simulation and demands for its validation; results and demands for flood hazard assessment. (orig.)

2000-07-01

327

An Hp-Adaptive Hierarchical Formulation for the Boundary Element Method Applied to Elasticity in Two Dimensions  

Scientific Electronic Library Online (English)

Abstract in english This paper presents an HP-Adaptive Procedure with Hierarchical formulation for the Boundary Element Method in 2-D Elasticity problems. Firstly, H, P and HP formulations are defined. Then, the hierarchical concept, which allows a substantial reduction in the dimension of equation system, is introduced. The error estimator used is based on the residual computation over each node inside an element. Finally, the HP strategy is defined and applied to two examples.

2002-03-01

328

Administration of a Decoction of Sucrose- and Polysaccharide-Rich Radix Astragali (Huang Qi) Ameliorated Insulin Resistance and Fatty Liver but Affected Beta-Cell Function in Type 2 Diabetic Rats  

UK PubMed Central (United Kingdom)

The current investigation attempted to confirm the beneficial actions of a chemically characterized Radix Astragali decoction (AM-W) against type 2 diabetic (T2D) Sprague-Dawley (SD) rats. Using a case/control...Full Text Available

2011-01-01

329

2D cavity grid quantum computing  

Energy Technology Data Exchange (ETDEWEB)

We propose a novel scheme for scalable solid state quantum computing, where superconducting microwave transmission line resonators (cavities) are arranged in a two-dimensional grid on the surface of a chip, coupling to superconducting qubits (charge or flux) at the intersections. We analyze how tasks of quantum information processing can be implemented in such a topology, including efficient two-qubit gates between any two qubits on the grid and elements of fault-tolerant computation.

2008-07-01

330

Neutron scattering and models: iron  

Energy Technology Data Exchange (ETDEWEB)

Differential elastic and inelastic neutron-scattering cross sections of elemental iron are measured from 4.5 to 10 MeV in increments of {approx}0.5 MeV. The measurements are made at >or{approx}40 scattering angles distributed between {approx}17 and 160 , with emphasis on elastic scattering and inelastic scattering due to the excitation of the yrast 2{sup +} state. The measured data is combined with earlier lower-energy results from this laboratory, with recent high-precision {approx}9.5-15 MeV results from the Physikalisch. Technische Bundesanstalt and with selected values from the literature to provide a detailed neutron-scattering data base extending from {approx}1.5 to 26 MeV. This data is interpreted in the context of spherical-optical and coupled-channels (vibrational and rotational) models, and the physical implications are discussed. Deformation, coupling, asymmetry and ...

1996-08-12

331

Evaluation of small-angle neutron scattering curves of unilamellar phosphatidylcholine liposomes using a multi shell model of bilayer neutron scattering length density  

International Nuclear Information System (INIS)

Computer simulated small-angle neutron scattering curves of spherical poly disperse extruded unilamellar liposomes from saturated 1,2-diacylphosphatidylcholines in the aqueous phase are evaluated by using a multi shell model, which divides the lipid bilayer of liposomes into the polar head group region, and the nonpolar hydrocarbon region consisting of the chains of methylene groups and of the region of methyl groups. In the each of these regions, the coherent neutron scattering length density is supposed to by homogeneous. The evaluation is based on obtaining of radius of gyration from Kratky-Porod plot of small-angle neutron scattering data in the Guinier region of small scattering vector values. From radii of gyration obtained at several different molar fractions N_D_2_O/(N_D-2_O + N_H_2_O) in the aqueous phase (contrasts) and independent volumetric data, the lipid surface area A_L (or the bilayer ...

2000-12-15

332

Application of neutron diffraction in chemistry. Pt. 2  

Energy Technology Data Exchange (ETDEWEB)

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

1982-01-01

333

Anomalous angular distributions in pion and {alpha} particle scattering to the 2{sub 2}{sup +} state of {sup 52}Cr  

Energy Technology Data Exchange (ETDEWEB)

Inelastic scattering of 180 MeV {pi}{sup +} and {pi}{sup {minus}} from {sup 52}Cr shows an angular distribution for the 2{sub 2}{sup +} state at 2.96 MeV that differs greatly from the usual {ital L} = 2 shapes for 2{sup +} states. This state is perhaps the only case from pion-inelastic scattering in which standard distorted-wave impulse approximation models (including multistep and single-step responses) fail to reproduce the measured angular distribution. Furthermore, this unique excitation has been shown to have the features expected of a seniority-four proton excitation yet the pion data show charge symmetry. While coupled-channel calculations are not able to reproduce the pion data, they do agree with the shape observed for 42 MeV {alpha} particle scattering to this state, but the magnitude of the {alpha} scattering data is not consistent with a collective model and known {gamma} ray deexcitations. ...

1996-02-01

334

Anomalous angular distributions in pion and #alpha# particle scattering to the 2_2"+ state of "5"2Cr  

International Nuclear Information System (INIS)

Inelastic scattering of 180 MeV #pi#"+ and #pi#"- from "5"2Cr shows an angular distribution for the 2_2"+ state at 2.96 MeV that differs greatly from the usual L = 2 shapes for 2"+ states. This state is perhaps the only case from pion-inelastic scattering in which standard distorted-wave impulse approximation models (including multistep and single-step responses) fail to reproduce the measured angular distribution. Furthermore, this unique excitation has been shown to have the features expected of a seniority-four proton excitation yet the pion data show charge symmetry. While coupled-channel calculations are not able to reproduce the pion data, they do agree with the shape observed for 42 MeV #alpha# particle scattering to this state, but the magnitude of the #alpha# scattering data is not consistent with a collective model and known #gamma# ray deexcitations. Scattering to the ...

335

Suppression of pitting corrosion with passive film modification on type 304 stainless steel by ultra-violet light irradiation; Shigaikoshosha ni yoru Type 304 stainless ko no fudotai himaku kaishitsu to koshoku yokusei  

Energy Technology Data Exchange (ETDEWEB)

In this study, the effects of 325nm wavelength ultraviolet light irradiation on pitting corrosion behavior of type 340 stainless steel in a neutral chloride solution are studied. Further, the change of passive film with the light irradiation is analyzed using x-ray photoelectron spectroscopy. The mains results obtained therefrom are stated below. Pitting potential can be shifted in noble direction by the ultraviolet light irradiation. The effect of ultraviolet light irradiation is ore prominent in the pitting corrosion process than that in the passive film formation. The result of the analysis in terms of the birth and death stochastic probability process shows that pitting corrosion rate is decreased remarkably by the ultraviolet light irradiation at the formation of passive film, while the repassivation is slightly expedited by the ultraviolet light ...

1998-06-20

336

A study of light hydrocarbons (C{sub 4}-C{sub 1}3) in source rocks and petroleum fluid  

Energy Technology Data Exchange (ETDEWEB)

This thesis consists of an introduction and five included papers. Of these, four papers are published in international journals and the fifth was submitted for review in April 2000. Emphasis has been placed on both naturally and artificially generated light hydrocarbons in petroleum fluids and their proposed source rocks as well as direct application of light hydrocarbons to oil/source rock correlations. Collectively, these papers describe a strategy for interpreting the source of the light hydrocarbons in original oils and condensates as well as the source of the asphaltene fractions from the reservoir fluids. The influence of maturity on light hydrocarbon composition has also been evaluated. The papers include (1) compositional data on the light hydrocarbons from thermal extracts and kerogen pyrolysates of sediment samples, (2) light hydrocarbon data of oils ...

2000-07-01

337

Resonance scattering of Lyman-. cap alpha. radiation by hydrogen in the ground state  

Energy Technology Data Exchange (ETDEWEB)

We calculate the cross section for the resonance scattering of Lyman-..cap alpha.. radiation by spinless nonrelativistic hydrogen atoms in the ground state using a two-level model. A generalization of Dirac's resonance scattering theory is used together with the exact matrix elements for the electromagnetic interaction. In contrast to the usual treatments in which only the dipole approximation for the matrix elements are taken, the shift in position of the resonance is finite and has a value of 75% of the Lamb shift of the n=1 state. Whether this latter fact is significant in renormalization calculations is left open.

1980-11-01

338

Neutron scattering study on the normal-incommensurate phase transition in K2ZnCl4  

Energy Technology Data Exchange (ETDEWEB)

The normal-incommensurate phase transition in K2ZnCl4 was studied by neutron scattering measurements. A well-defined soft phonon behavior was not observed above the normal-incommensurate transition temperature of Tsub(i)=288C. Diffuse scattering develops around(h,0,1 +- 0.3) as temperature approaches Tsub(i) from above, and the peak intensity obeys a Curie-Weiss law above Tsub(i). The results indicate that the normal-incommensurate phase transition in K2ZnCl4 can be interpreted as an order-disorder process.

1984-12-01

339

Neutron cross section measurements using the Oak Ridge Electron Linear Accelerator  

Energy Technology Data Exchange (ETDEWEB)

During this reporting period the work supported by the US Department of Energy Grant No. DE-FG02-87ER40326.A005 has resulted in two publications and two papers presented at professional meetings. The neutron scattering measurement for this budget period has been completed along with scattering measurements for carbon {sup 88}Sr, {sup 40}Ar, {sup 90}Zr, {sup 208}Pb, {sup 40}Ca and {sup 28}Si. The carbon scattering yield serves to define the detector efficiencies. The silicon sample was available and is of importance in both nuclear physics and reactor physics.

1992-06-01

340

Envelope correlation in (N, N) MIMO antenna array from scattering parameters  

DEFF Research Database (Denmark)

A simple closed-form equation to calculate the envelope correlation between any two receiver or transmitter antennas in a multi-input multi-output (MIMO) system of an arbitrary number of elements is derived. The equation uses the scattering parameters obtained at the antenna feed point to calculate the envelope correlation coefficient. This approach has the advantage that it does not require knowledge of the antenna radiation pattern. Numerical data that include conductor and permittivity loss are shown to validate the approach. Using the scattering parameters for calculating the envelope correlation is less laborious and relatively cheaper, as compared to the radiation pattern approach.

2006-01-01

341

Effect of substrate on the results of measuring coating thickness according to radiation scattered by substrate  

International Nuclear Information System (INIS)

The effect of a substrate on the results of measuring tantalum coating thickness in two-layer compositions according to gamma radiation scattered by the substrate is studied. It is shown that by means of an albedo-radiometer realizing the physical model absorber-scatterer one can determine the thickness (application uniformity) of tantalum coatings up to 150-300 #mu#m depending on the substrate material (plexiglas, aluminium, iron, copper). In case of testing coatings on substrates of alloys and high-alloy steels in order to ensure high accuracy of measrurement it is expedient with the above albedo-radiometer to determine the value of the backscattered radiation flux for the substrate before coating application.

342

Coupled-channels calculations of elastic and inelastic scattering  

Energy Technology Data Exchange (ETDEWEB)

Cross sections for the elastic and inelastic scattering of /sup 16/O on /sup 58/Ni, /sup 88/Sr, /sup 40/Ca, and /sup 48/Ca have been calculated in a coupled-channels treatment, including the low-lying 2/sup +/ and 3/sup /minus// states of both projectile and target. Real, energy-independent ion-ion potentials and form factors were used, and fusion was simulated by ingoing wave boundary conditions in all channels. The agreement with the measured scattering data is qualitatively as good as obtained in previous optical-model calculations.

1989-07-01

343

Coupled-channels calculations of elastic and inelastic scattering  

International Nuclear Information System (INIS)

Cross sections for the elastic and inelastic scattering of "1"6O on "5"8Ni, "8"8Sr, "4"0Ca, and "4"8Ca have been calculated in a coupled-channels treatment, including the low-lying 2"+ and 3"- states of both projectile and target. Real, energy-independent ion-ion potentials and form factors were used, and fusion was simulated by ingoing wave boundary conditions in all channels. The agreement with the measured scattering data is qualitatively as good as obtained in previous optical-model calculations.

344

Applications of X-ray scattering in pharmaceutical science  

British Library Electronic Table of Contents (United Kingdom)

The use of X-ray scattering techniques in pharmaceutical science is increasing, in part through increased collaborations with the materials science community, and through increased availability of instrumentation, particularly synchrotron sources. The ability to understand not only the biopharmaceutical outcome, but also arguably, more importantly, the structural aspects of drugs and drug delivery systems, is essential to progressing pharmaceutical science; this review serves as an introduction to the major techniques and the wide range of areas in which X-ray scattering may be applied in understanding and controlling structure in pharmaceutical systems.

2011-01-01

345

Alpha-particle scattering from Ca-nuclei  

International Nuclear Information System (INIS)

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

1979-07-01

347

Unparticle Physics in DIS  

CERN Document Server

The unparticle stuff which is described by the theory with notrivial IR fixed point is recently suggested to exist in our world by Georgi. We illustrate its physical effects in deep inelastic scattering process in this letter.

2007-01-01

350

Structure and morphology changes during nylon 66 fiber deformation via synchrotron x-ray scattering techniques  

Energy Technology Data Exchange (ETDEWEB)

Morphological and structural changes of nylon 66 were evaluated during a continuous heat-draw process. Results are discussed.

1996-12-31

352

SAXS studies on added-salt species dependence of conformation of fully-charged poly(L-glutamate) in aqueous solutions  

Energy Technology Data Exchange (ETDEWEB)

The effect of counter-ion species on the local conformation of fully-charged poly(L-glutamate) in added-salt aqueous solutions were studied by small-angle X-ray scattering(SAXS). In the case of presence of monovalent counter-ion, the scattering behaviour could be explained by taking into consideration the excluded volume effect and intermolecular-interface interaction on the scattering function of wormlike chain. On the other hand, since SAXS profile of the solution in the presence of divalent counter-ion well fitted to the scattering function of dendrimer, it suggested that the conformation of polymer chain in such solution would be more compact conformation than that of presence of monovalent ion.

2010-10-01

353

Quark-hadron duality in neutrino scattering  

Energy Technology Data Exchange (ETDEWEB)

We present a phenomenological model of the quark-hadron transition in neutrino-nucleon scattering. Using recently extracted weak nucleon transition form factors, we investigate the extent to which local and global quark-hadron duality is applicable in the neutrino F{sub 1}, F{sub 2} and F{sub 3} structure functions, and contrast this with duality in electron scattering. Our findings suggest that duality works relatively well for neutrino-nucleon scattering for the F{sub 2} and F{sub 3} structure functions, but not as well for F{sub 1}. We also calculate the quasi-elastic, resonance and deep inelastic contributions to the Adler sum rule, and find it to be satisfied to within 10% for 0.5 < Q{sup 2} < 2 GeV{sup 2}.

2006-07-24

356

Nucleon Form Factor Measurements and Interpretation  

Energy Technology Data Exchange (ETDEWEB)

The data base for the form factors of the nucleon obtained from elastic ep scattering is discussed, as well as some recent developments in their calculation.

2007-08-22

357

Inverse Scattering and Applications. Proceedings of ...  

Science.gov (United States)

... Richrd Bals andLina PrissJames Lepowsky and Mirko Primc Richard Beaals, and Linda Preiss Rothschild, Editors 47 Linear algebra and its role in ...

2011-05-14

361

Elastic and inelastic scattering of "1"4C from medium heavy nuclei  

International Nuclear Information System (INIS)

The elastic and inelastic scattering of "1"4C at 51 MeV from targets of "4"0Ca, "5"6Fe, "6"0Ni, "6"6Zn and "8"8Sr has been measured using a Q3D spectrometer. The "1"4C-nucleus potentials have been derived by optical-model analysis of the observed elastic scattering; the inelastic scattering differential cross sections were interpreted in the distorted-wave Born approximation and also in the coupled-channels approach. The analysis yields "1"4C-nucleus potentials that closely resemble "1"2sup(,)"1"3C and "1"6O potentials. (orig.).

362

Elastic and inelastic 27.2 MeV alpha particle scattering on the nickel isotopes  

International Nuclear Information System (INIS)

Russian 1974. USSR Alekseev, VV Nemets, OF Stryuk, Yu.S. Tokarevskij,

1974-01-29

363

Deformation of "5"6Fe from 104 MeV #alpha#-particle scattering  

International Nuclear Information System (INIS)

(1 Apr 1975). United Kingdom Gils, HJ Rebel, H. Nowicki, G. Ciocanel, A.

366

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

UK PubMed Central (United Kingdom)

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

1999-03-30

367

50.5 MeV alpha particle scattering on sup(54,56)Fe nuclei  

International Nuclear Information System (INIS)

Russian 1979. p. 328. USSR Burtebaev, NT Dujsebaev, AD Ivanov, GN

368

19-27 MeV alpha-particle elastic scattering on actinide nuclei  

International Nuclear Information System (INIS)

Russian 1977. p. 270. USSR Zaika, NI Kibkalo, Yu.V. Mokhnach, AV Nemets,

369

Technique for compressing light intensity ranges utilizing a specifically designed liquid crystal notch filter  

Energy Technology Data Exchange (ETDEWEB)

A pin hole camera assembly for use in viewing an object having a relatively large light intensity range, for example a crucible containing molten metal in an atomic vapor laser isotope separation (AVLIS) system is disclosed herein. The assembly includes means for optically compressing the light intensity range appearing at its input sufficient to make it receivable and decipherable by a standard video camera. To accomplish this, the assembly utilizes the combination of interference filter and a liquid crystal notch filter. The latter which preferably includes a cholesteric liquid crystal arrangement is configured to pass light at all wavelengths, except a relatively narrow wavelength band which defines the filter's notch, and includes means for causing the notch to vary to at least a limited extent with the intensity of light at its light incidence surface.

1988-01-01

370

High-power operation of heterobarrier blocking structure InGaAlP visible light laser diodes  

Energy Technology Data Exchange (ETDEWEB)

Heterobarrier blocking structure InGaAlP visible light laser diodes employing a thin active layer (0.04 {mu}m) and asymmetry coatings have been fabricated. The high light-output power operation with this heterobarrier blocking structure was investigated. The light-output power versus cw current curve was linear up to 43 mW and a maximum light output power of 51 mW was obtained. A high-power operation such as 20 mW was maintained at 40 {degree}C. Stable oscillation in the fundamental transverse mode was obtained up to 30 mW. These results show that this heterobarrier blocking structure supplies a sufficient current confinement effect even under a high-light output power operation.

1990-04-30

371

Visible-light resin-curing units: retinal hazards and protective lenses. Final report, December 1982-May 1986  

Energy Technology Data Exchange (ETDEWEB)

The potential retinal hazard of dental visible-light photopolymerization units and the efficacy of protective lenses for reducing the potential hazards were assessed. The spectral radiance profiles of 11 visible-light photopolymerization units were measured; and the results were then weighted according to the American Conference of Governmental Industrial Hygienists (ACGIH) Blue Light and Thermal Hazard Functions. The results indicate that there are no thermal hazards to the retina even for the worst case condition. None of the blue-light hazard maximum permissible exposure times is short enough to be of concern unless the individual operator chooses to focus on the light source for an extended period. Those individuals who elect to stare at the light during curing procedures should consider the purchase of protective lenses. The special transmission profiles of ...

1986-11-01

372

Variation in the action spectrum of erythrolabe among deuteranopes.  

UK PubMed Central (United Kingdom)

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

1977-04-01

373

Retinal channelrhodopsin-2-mediated activity in vivo evaluated with manganese-enhanced magnetic resonance imaging  

UK PubMed Central (United Kingdom)

PurposeEctopic expression of light-sensitive proteins, such as channelrhodopsin-2, represent a novel approach for restoring light-detection capabilities to degenerated retina. A...Full Text Available

374

Rapid Correlation between the Leaves of Spinach and the Photocontrol of a Peroxidase Activity 1  

UK PubMed Central (United Kingdom)

The activity of a basic peroxidase extracted at high pH from spinach (Spinacia oleracea) leaves is modified by an irradiation with 2-minute red light or 2-minute far red light. This...Full Text Available

1982-02-01

375

Preliminary results from an advanced lighting controlstestbed  

Energy Technology Data Exchange (ETDEWEB)

Preliminary results from a large-scale testbed of advanced lighting control technologies at the Phillip Burton Federal Building at 450 Golden Gate Ave. in San Francisco are presented. The first year objective of this project is to determine the sustainable energy savings and cost-effectiveness of different lighting control technologies compared to a portion of the building where only minimal controls are installed. The paper presents the analyzed results from six months of tests focused on accurately characterizing the energy savings potential of one type of daylight-linked lighting controls compared to the lighting in similar open-planned areas without dimming controls. After analyzing a half year;s data, we determined that the annual energy savings for this type of daylight- linked controls was 41% and 30% for the outer rows of lights on the South and North sides of the building, ...

1998-03-01

376

Phytochrome Control of Maize Coleoptile Section Elongation 1  

UK PubMed Central (United Kingdom)

A rapid loss of far red light (FR) reversibility of red-light (R) stimulated elongation of maize coleoptile sections was observed. Reversal was not possible when the interval between R and FR treatment...Full Text Available

1981-02-01

377

Photographic measurements of the diffuse light in the coma cluster  

International Nuclear Information System (INIS)

The diffuse background light in the Coma cluster is measured using isodensity tracings of B, G, V, and R photographic plates taken with the Palomar 1.2-m Schmidt telescope. The isodensity contours are calibrated using the star profile derived by Kormendy (1973). Between 4 and 14 arc min from the center, the surface brightness of the diffuse light decreases from approximately 26 to approximately 28 G magnitudes arc sec"-"2. The total magnitude in this annulus is G = 11.22, which is approximately 45 percent of the light in galaxies alone, or approximately 30 percent of the total. This does little to alleviate the ''missing mass'' problem. The isodensity contours and the equivalent profile of the diffuse light closely parallel the distribution of light in galaxies, implying no strong mass segregation. However, the background light appears to be bluer than the ...

378

Light duty utility arm startup plan  

Energy Technology Data Exchange (ETDEWEB)

This plan details the methods and procedures necessary to ensure a safe transition in the operation of the Light Duty Utility Arm (LDUA) System. The steps identified here outline the work scope and identify responsibilities to complete startup, and turnover of the LDUA to Characterization Project Operations (CPO).

1998-09-01

379

Light amplifier with filtering of spontaneous background  

Energy Technology Data Exchange (ETDEWEB)

A comparitive analysis is made of the principal characteristics of narrow-band and conventional semiconductor light amplifiers. It is shown that quasi-distributed filtering of the spontaneous radiation ensures a high gain and a low level of the spontaneous noise at the amplifier output.

1980-06-01

380

Increased Sensitivity to Light-Induced Melatonin Suppression in Premenstrual Dysphoric Disorder  

UK PubMed Central (United Kingdom)

Increased sensitivity to light-induced melatonin suppression characterizes some, but not all, patients with bipolar illness or seasonal affective disorder. The aim of this study was to test...Full Text Available

2010-08-01

381

Far-Red Light-Induced Changes in Intracellular Potentials of Spinach Mesophyll Cells  

UK PubMed Central (United Kingdom)

In green plants, the large bioelectric changes that photosynthetically active light stimulates make it difficult to observe electrical potential changes related to phytochrome photoconversion. As a...Full Text Available

1983-11-01

382

Electrical - light current remote monitoring, control and automation. [Coal mine, United Kingdom  

Energy Technology Data Exchange (ETDEWEB)

A brief discussion is given of the application of control monitoring and automation techniques to coal mining in the United Kingdom, especially of the use of microprocessors, for the purpose of enhancing safety and productivity. Lighting systems for the coal mine is similarly discussed.

1981-06-01

383

Development of circadian rhythmicity and light responsiveness in the rat suprachiasmatic nucleus: a study using the 2-deoxy[1-14C]glucose method.  

UK PubMed Central (United Kingdom)

The suprachiasmatic nucleus (SCN) of the hypothalamus is thought to play a critical role in circadian rhythm generation and entrainment to the light/dark cycle. In adult rats, the SCN shows a circadian...Full Text Available

1980-02-01

384

DNA Damage during G2 Phase Does Not Affect Cell Cycle Progression of the Green Alga Scenedesmus quadricauda  

UK PubMed Central (United Kingdom)

DNA damage is a threat to genomic integrity in all living organisms. Plants and green algae are particularly susceptible to DNA damage especially that caused by UV light, due to their light dependency...Full Text Available

385

Crystallographic structure of xanthorhodopsin, the light-driven proton pump with a dual chromophore  

UK PubMed Central (United Kingdom)

Homologous to bacteriorhodopsin and even more to proteorhodopsin, xanthorhodopsin is a light-driven proton pump that, in addition to retinal, contains a noncovalently bound carotenoid with a function...Full Text Available

2008-10-28

386

Characterization of the Key Step for Light-driven Hydrogen Evolution in Green Algae*  

UK PubMed Central (United Kingdom)

Under anaerobic conditions, several species of green algae perform a light-dependent hydrogen production catalyzed by a special group of [FeFe] hydrogenases termed HydA. Although highly interesting...Full Text Available

2009-12-25

387

Antisense Expression of the CK2 ?-Subunit Gene in Arabidopsis. Effects on Light-Regulated Gene Expression and Plant Growth1  

UK PubMed Central (United Kingdom)

The protein kinase CK2 (formerly casein kinase II) is thought to be involved in light-regulated gene expression in plants because...Full Text Available

1999-03-01

388

A Turquoise Mutant Genetically Separates Expression of Genes Encoding Phycoerythrin and Its Associated Linker Peptides  

UK PubMed Central (United Kingdom)

During complementary chromatic adaptation (CCA), cyanobacterial light harvesting structures called phycobilisomes are restructured in response to ambient light quality shifts. Transcription of genes...Full Text Available

2002-02-01

389

Weyl gauge, Schwinger terms and bosonization in light-front field theory  

Energy Technology Data Exchange (ETDEWEB)

A systematic study of non-perturbative quantum structure of the massive light-front Schwinger model and QED(3+1) in the continuum formulation is outlined. The light-front Hamiltonian and field algebra are derived in the Weyl gauge using the Dirac-Bergmann constrained quantization. Unitary transformation to the light-cone gauge representation is performed and the gauge-invariant fermi field is constructed. The importance of the Schwinger term in the current-current commutation relations for the derivation of the fermionic vacuum structure and bosonization in two dimensions is indicated.

2002-04-01

390

The distribution of mass-to-light ratio with radius in M31 and M33  

International Nuclear Information System (INIS)

1974. Netherlands Baldwin, JE Cambridge Univ. (UK). Cavendish Lab. Reidel.;

391

Light Scalar Mesons as Manifestation of Spontaneously Broken Chiral Symmetry  

CERN Document Server

Attention is paid to the production mechanisms of light scalars that reveal their nature. We reveal the chiral shielding of the \\sigma(600) meson. We show that the kaon loop mechanism of the \\phi radiative decays, ratified by experiment, points to the four-quark nature of light scalars. We show also that the light scalars are produced in the two photon collisions via four-quark transitions in contrast to the classic P wave tensor q\\bar q mesons that are produced via two-quark transitions $\\gamma\\gamma\\to q\\bar q$. The history of spontaneous breaking of symmetry in quantum physics is discussed in Appendix.

2010-01-01

394

Virtual Compton Scattering: Results from Jefferson Lab  

Energy Technology Data Exchange (ETDEWEB)

Virtual Compton Scattering o013 the proton has been studied at Q 2 -values of 1:0 and 1:9 (GeV=c) 2 in Hall A at the Thomas Je013erson National Accelerator Facility (JLab). Data were taken below and above the pion production threshold as well as in the resonance region. Results obtained below pion threshold at Q 2 = 1:0 (GeV=c) 2 are presented in this paper.

2003-05-01

395

Theory of chemical reaction dynamics. Volume 1  

Energy Technology Data Exchange (ETDEWEB)

This book examines some of the basic principles behind chemical reactions kinetics. Topics considered include ab initio determination of potential energy for chemical reactions; semi-empirical potential energy surfaces; general theory of reactive scattering: different equation approach; and integral equation approach to reactive scattering.

1985-01-01

396

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

International Nuclear Information System (INIS)

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

397

Tensor polarization of "6Li(2.18 MeV, 3"+) as a result of 80 MeV #alpha#-particle inelastic scattering  

International Nuclear Information System (INIS)

Tensor polarization of "6Li(2.18 MeV, 3"+) nucleus at inelastic scattering of #alpha# particles for #THETA#_l_a_b=45 deg angle is measured. The results are described by the calculations in terms of Born approximation of distorted waves with internucleonic interaction realistic potential.

398

Suppression of the transverse scattering amplitude in /sup 207/Pb  

Energy Technology Data Exchange (ETDEWEB)

Transverse form factors have been extracted for the low-lying neutron hole (particle) states of /sup 207/Pb from inelastic-electron-scattering data. A systematic, multipolarity-and momentum-transfer-independent quenching of approx.55% in the transverse amplitude is observed when compared with single particle predictions for both electric and magnetic transitions. The magnitude of the observed effect is not readily explained by our present theoretical understanding of this nucleus.

1980-07-14

399

Study on correlations of parameters of the optical potential of 38 MeV alpha particle elastic scattering on sup(68)Zn  

International Nuclear Information System (INIS)

Correlations of the Woods-Saxon four-parameter optical potential of scattering of 38 MeV #alpha# particles on sup(68)Zn have been analyzed. A search for discrete sets of potential parameters and functional ratios between different parameters is carried out.

400

Structure of unilamellar vesicles: Numerical analysis based on small-angle neutron scattering data  

International Nuclear Information System (INIS)

The structure of polydispersed populations of unilamellar vesicles is studied by small-angle neutron scattering for three types of lipid systems, namely, single-, two-and four-component vesicular systems. Results of the numerical analysis based on the separated-form-factor model are reported.

2006-12-01

401

Structural intermediates in the assembly of taxoid-induced microtubules and GDP-tubulin double rings: time-resolved X-ray scattering.  

UK PubMed Central (United Kingdom)

We have studied the self-association reactions of purified GDP-liganded tubulin into double rings and taxoid-induced microtubules, employing synchrotron time-resolved x-ray solution scattering. The...Full Text Available

1996-05-01

402

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

International Nuclear Information System (INIS)

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

2004-11-29

403

Some capabilities of neutron methods for investigating materials and components of devices used in hydrogen power engineering  

International Nuclear Information System (INIS)

Structural units of a hydrogen fuel cell whose characteristics are advisable to investigate by different neutron scattering methods are discussed. The results obtained with the use of Bragg diffraction and small-angle neutron scattering from fuel membranes, nanocarbon-platinum catalysts, and Zn_1_-_xCu_xO hydrogen storage systems are presented.

2007-05-01

404

Scattering of scalar tardyons and tachyons from a Schwarzschild black hole  

Energy Technology Data Exchange (ETDEWEB)

The Klein-Gordan equation in the background of the Schwarzschild curved space-time is considered and the scattering of radial tardyons and tachyons from a black hole is studied. It is shown that black holes of mass below 7x10/sup 14/g may contain bound states of tardyons of pion mass which will be unstable on account of the presence of an attractive r/sup -4/ term.

1982-10-01

405

Scattering of scalar tardyons and tachyons from a Schwarzschild black hole  

International Nuclear Information System (INIS)

The Klein-Gordan equation in the background of the Schwarzschild curved space-time is considered and the scattering of radial tardyons and tachyons from a black hole is studied. It is shown that black holes of mass below 7x10"1"4g may contain bound states of tardyons of pion mass which will be unstable on account of the presence of an attractive r"-"4 term. (author).

406

Scattered radiation effect on the defect image in high-energy bremsstrahlung introscopy  

International Nuclear Information System (INIS)

Results of the evaluation of the scattered radiation effect on the image of defects in examined products are given. The formula is suggested which characterizes the image of defects on a scintillation screen as well as accumulation factors are calculated by the Monte-Carlo method. Values of fluctuations of absorbed energy in the screen used for the evaluation of sensitivity are experimentally obtained. The effect of high-energy bremsstrahlung on the defect detection is analyzed.

407

Remote measurement of methane in coal mines: a review  

Energy Technology Data Exchange (ETDEWEB)

The authors identify a need for a device which can remotely measure methane in coal mines. Similar techniques which have been used to measure atmospheric pollutants are discussed. These techniques include adsorption, Raman scattering and fluorescence. While differential adsorption and Raman scattering techniques have potential there are a number of problems to be resolved before they could be applied effectively. It is felt that an area which may provide suitable technology sometime in the future is in the field of laser sources. 6 refs., 4 tabs.

1987-02-01

408

Radioanalytical chemistry. Vol. 2  

International Nuclear Information System (INIS)

This volume of the monograph covers the following topics: activation analysis, non-activation interaction analysis (elastic scattering of charged particles, absorption and backscattering of beta radiation and photons, radionuclide X-ray fluorescence analysis, thermalization, scattering and absorption of neutrons, use of ionization caused by nuclear radiation, use of ionization by alpha or beta radiation for the measurement of pressure, density and flow rate of gases), and automation in radioanalytical chemistry. (P.A.).

1989-01-01

409

Quark-Hadron Duality in Electron Scattering  

Energy Technology Data Exchange (ETDEWEB)

Quark-hadron duality addresses some of the most fundamental issues in strong interaction physics, in particular the nature of the transition from the perturbative to non-perturbative regions of QCD. I summarize recent developments in quark-hadron duality in lepton-hadron scattering, and outline how duality can be studied at future high-luminosity facilities such as Jefferson Lab at 12 GeV, or an electron-hadron collider such as EPIC.

2000-09-01

410

Performance of a large Bragg-curve spectrometer  

Energy Technology Data Exchange (ETDEWEB)

A large Bragg-curve spectrometer has been constructed and tested. The detector has a cylindrical geometry and operates with a homogeneous electric field. Energy resolutions of <0.8% and Z resolutions of Z/..delta..Z=80 have been achieved for eleastically scattered /sup 58/Ni ions. These results demonstrate the suitability of this large solid-angle detector for use in a wide variety of heavy-ion scattering experiments.

1987-04-01

411

Performance of a large Bragg-curve spectrometer  

International Nuclear Information System (INIS)

A large Bragg-curve spectrometer has been constructed and tested. The detector has a cylindrical geometry and operates with a homogeneous electric field. Energy resolutions of <0.8% and Z resolutions of Z/#DELTA#Z=80 have been achieved for eleastically scattered "5"8Ni ions. These results demonstrate the suitability of this large solid-angle detector for use in a wide variety of heavy-ion scattering experiments. (orig.).

412

Pairing correlation effects on the electron-scattering form factor of the 1/sup +/ state at 3. 486 MeV in /sub 38//sup 88/Sr/sub 50/  

Energy Technology Data Exchange (ETDEWEB)

The electron scattering form factor for excitation of the 1/sup +/ state of /sup 88/Sr at 3.486 MeV has been calculated in the quasiparticle random phase approximation (QRPA). The disagreement between the data and restricted shell-model calculations can be explained in terms of the pairing correlations introduced by the QRPA; no ..delta..-h admixtures are required.

1985-06-06

413

Pairing correlation effects on the electron-scattering form factor of the 1"+ state at 3.486 MeV in _3_8"8"8Sr_5_0  

International Nuclear Information System (INIS)

The electron scattering form factor for excitation of the 1"+ state of "8"8Sr at 3.486 MeV has been calculated in the quasiparticle random phase approximation (QRPA). The disagreement between the data and restricted shell-model calculations can be explained in terms of the pairing correlations introduced by the QRPA; no #DELTA#-h admixtures are required. (orig.).

414

Paclitaxel distribution in poly(ethylene glycol) / poly(lactide-co-glycolic acid) blends and its release visualized by coherent anti-Stokes Raman scattering microscopy  

UK PubMed Central (United Kingdom)

Mechanisms underlying the release of paclitaxel (PTX) from poly(ethylene glycol)/poly(lactic-co-glycolic acid) (PEG/PLGA) blends were investigated by coherent anti-Stokes Raman scattering (CARS)...Full Text Available

2007-10-08

415

P-odd asymmetries in deep inelastic scatterings of polarized leptons on nuclei  

International Nuclear Information System (INIS)

The P-odd asymmetries in deep inelastic scattering (DIS) of polarized leptons on nuclei are considered in the framework of the standard model and the parton-flucton model. The model predictions, within the experimental errors,agree well with the present data. 13 refs., 2 figs., 2 tabs. (author).

416

Null field method in wave diffraction problems  

British Library Electronic Table of Contents (United Kingdom)

Diffraction by an impermeable scatterer in ?3 with a Dirichlet boundary condition is considered. It is shown that the null field equation is equivalent to the original diffraction problem. The general theoretical constructions are illustrated by analyzing the excitation of a sphere by a point source. The evolution of the residual of the null field equation as the scatterer surface is approached by an auxiliary surface is estimated.

2011-01-01

417

Nuclear scattering and suprathermal fusion  

Energy Technology Data Exchange (ETDEWEB)

The effect of nuclear scattering on the suprathermal fusion probability of recoiling d-t nuclei under the impact of fusion products, a 14.1-MeV neutron and a 3.5 MeV alpha particle, in thick pellets is investigated with the help of the Boltzmann-Fokker-Planck equation. Although the suprathermal fusion from alpha-particle recoils is quite small, the one originating from neutron recoils is considerable.

1987-11-01

418

New designs for Ultra High High-Power Single Transverse Mode Cw fibre lasers  

International Nuclear Information System (INIS)

Overcoming the limiting constraints of stimulated Raman scattering (SRS) and stimulated Brilluoin scattering (SBS) poses serious fibre design challenges for increasing the output power of optical amplifiers and lasers. New fibre amplifier designs are proposed to break out of these limitations to reach several kWs CW powers. (Author)

2009-04-01

419

Multi-mirror system, 2. Application of inverse Compton Scattering for lithography X-ray sources  

Energy Technology Data Exchange (ETDEWEB)

A brilliant X ray source is proposed for lithography instruments with use of a multi-mirror system. The inverse Compton scattering between the stored electron beam in the storage ring and the stored photon beam in the multi-mirror system, is applied for the X-ray generation. (author)

2000-07-01

420

Multi-channel algebraic scattering theory and the structure of exotic compound nuclei  

CERN Document Server

A Multi-Channel Algebraic Scattering (MCAS) theory is presented with which the properties of a compound nucleus are found from a coupled-channel problem. The method defines both the bound states and resonances of the compound nucleus, even if the compound nucleus is particle unstable. All resonances of the system are found no matter how weak and/or narrow. Spectra of mass-7 nuclei and of {}^{15}F, and MCAS results for a radiative capture cross section are presented.

2007-01-01

421

Modeling Radar Scattering from the Lunar Surface and Analysis of the Effect of Roughness and Ice Inclusions on CPR Values  

Science.gov (United States)

We developed a model for radar scattering from the lunar reoglith layer using vector radiative transfer theory. From this model, both the radar backscattering coefficient and the circular polarization ratio can be predicted analytically as a function of regolith parameters.

2010-03-01

422

Measurement of the elastic. pi. /sup -/ d backward scattering at 1. 57, 1. 66, and 1. 76 GeV/c  

Science.gov (United States)

The results of measuring elastic ..pi../sup -/ d backward scattering, which emphasize the structure in the energy dependence of this cross section observed by us at slightly lower energies, are presented. Its possible theoretical interpretation is discussed.

1980-01-20

423

Kinetics of the urea-induced dissociation of human plasma alpha 2-macroglobulin as measured by small-angle neutron scattering.  

UK PubMed Central (United Kingdom)

The kinetics of the urea-induced dissociation of human plasma alpha 2-macroglobulin into two half-molecular fragments was investigated at 21.0 degrees C by using small-angle neutron scattering. The...Full Text Available

1991-09-01

424

Induced radiation during scattering of channeled electrons and positrons by point defects  

Energy Technology Data Exchange (ETDEWEB)

In scattering of channeled particles by point defects and in emission of gamma rays in the spontaneous-radiation spectral region conditions are attained where the momentum transferred to the defect is taken up by the crystal as a whole. This leads to coherent and interference effects in the radiation from the crystal defects. When the longitudinal momentum transferred is zero, an induced radiation effect appears in the transitions between the states of transverse motion.

1984-12-01

425

Electron scattering in molecular aggregates  

International Nuclear Information System (INIS)

In this contribution we compare the electron scattering processes observed in pure O_2 clusters and mixed clusters like O_2/Ne, O_2/Ar and O_2/N_2. The overlap and positions of the potential curves of O_2 states show the different possible electron attachment processes and also explain the formation of O_2 in clusters. (author).

1994-03-20

426

Elastic scattering of 1 GeV protons from nuclei as a test for flucton model  

Energy Technology Data Exchange (ETDEWEB)

Cross sections for elastic scattering of 12 GeV protons from /sup 40/Ca nuclei have been calculated using the flucton model. The influence of the collective flucton nucleon correlations on the calculated cross sections is examined. The calculated cross sections are in significant disagreement with the experimental data. This may be considered as an argument against the flucton model.

1982-04-01

427

Elastic scattering of 1 GeV protons from nuclei as a test for flucton model  

International Nuclear Information System (INIS)

Cross sections for elastic scattering of 12 GeV protons from "4"0Ca nuclei have been calculated using the flucton model. The influence of the collective flucton nucleon correlations on the calculated cross sections is examined. The calculated cross sections are in significant disagreement with the experimental data. This may be considered as an argument against the flucton model. (orig.).

428

Dynamics of itinerant ferromagnets above T/sub c/  

Energy Technology Data Exchange (ETDEWEB)

The existence of propagating spin waves above T/sub c/ in Ni and Fe has been widely accepted since this picture was first advocated in 1973. In this brief review of our current neutron scattering experiments on Fe and Ni we will present convincing evidence showing that this picture is incorrect. In addition, we will demonstrate that over wide ranges of ..omega.., q and temperature, both Fe and Ni follow a simple paramagnetic scattering function of the spin diffusion type. 19 references.

1984-04-01

429

Differences of the deformation parameter #beta# for 2"+_1 states of even-even spherical nuclei from electromagnetic excitation and proton scattering  

International Nuclear Information System (INIS)

Differences of the deformation parameters for the 2"+_1 states of even-even spherical nuclei extracted from electromagnetic excitation #beta#sup(em)_2 and from proton scattering #beta#sup(pp')_2 are discussed. It is found that the ratio #beta#sup(pp')_2/#beta#sup(em)_2 is equal to about unity and that there is a small isotope dependence for several incomplete shell nuclei. (orig.).

430

An imaging. gamma. -ray detector with scatter rejection for beam position control in radiotherapy  

Energy Technology Data Exchange (ETDEWEB)

An imaging detector for {gamma}-rays ({approx equal}1 MeV) based on minicell MWPCs with converters and a position resolution of {Delta}x=0.5 mm has been developed and tested. Very high rate capability (>10{sup 8}/cm{sup 2} s) and a special readout for suppression of scattered radiation are implemented allowing to enhance the measured contrast. The relevant physical processes are discussed and first pictures are presented. (orig.).

1991-12-01

431

The Participation of Two Rhythms in the Leaf Movements of Xanthium Plants Given Various Light-Dark Cycles 1  

UK PubMed Central (United Kingdom)

We have shown Xanthium strumarium exhibit two distinct leaf movement rhythms with one occurring in continuous light and presumably related to an endogenous rhythm initiated by the “light-on”...Full Text Available

1974-02-01

432

Static-static-light-light tetraquarks in lattice QCD  

CERN Document Server

I report on a lattice computation of the energy of a system of two light quarks and two static antiquarks as a function of the separation of the static antiquarks. In terms of hadrons such a system corresponds to a pair of B mesons and its energy to the hadronic potential. I present selected results for different isospin, spin and parity combinations of the individual B mesons mainly focusing on those channels relevant to determine, whether two B mesons may form a bound tetraquark state.

2011-01-01

433

Rapid Respiratory Changes Due to Red Light or Acetylcholine during the Early Events of Phytochrome-mediated Photomorphogenesis 1  

UK PubMed Central (United Kingdom)

Two millimeter long secondary root tips of etiolated mung bean (Phaseolus aureus) plants were given 4 minute consecutive treatments of darkness, red light, far red light, and acetylcholine...Full Text Available

1972-01-01

434

Observations of time delayed all-optical routing in a slow light regime  

CERN Document Server

We report an observation of a delayed all-optical routing/switching phenomenon based on ultraslow group velocity of light via nondegenerate four-wave mixing processes in a defected solid medium. Unlike previous demonstrations of enhanced four-wave mixing processes using the slow light effects, the present observation demonstrates a direct retrieval of the resonant Raman-pulse excited spin coherence into photon coherence through coherence conversion processes.

2008-01-01

435

Observations of photon echo enhancement in an ultraslow light regime  

CERN Document Server

Using spectral hole-burning-based ultraslow group velocity in a dilute solid medium, we report enhanced photon echo efficiency three orders of magnitude higher than that in a nonslow light regime. The enhancement is due to exponentially increased absorption of an optical data pulse owing to the enhanced photon-atom interaction in an ultraslow light regime, whereas echo reabsorption is negligibly small due to group-velocity dependent population depletion.

2011-01-01

436

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-07-15

437

Assimilation of [15N]Nitrate and [15N]Nitrite in Leaves of Five Plant Species under Light and Dark Conditions 1  

UK PubMed Central (United Kingdom)

Light dependency of nitrate and nitrite assimilation to reduced-N in leaves remains a controversial issue in the literature. With the objective of resolving this controversy, the light requirement for...Full Text Available

1983-02-01

438

A class of finite one-loop light-cone integrals  

Energy Technology Data Exchange (ETDEWEB)

Using the manifestly causal gluon propagator in the light-cone gauge, we evaluate two one-loop Feynman integrals which appear in the computation of the three-gluon vertex correction in the two-component formalism of the Yang-Mills gauge fields. We conclude that they both are finite for {omega} -> 2, where {omega} is the dimensional regulator. They belong to a class of finite one-loop light-cone integrals. (author). 7 refs.

1992-10-01

439

Dosimetric characteristics of backscattered electrons in lead  

Energy Technology Data Exchange (ETDEWEB)

In electron beam therapy, tissue overdose due to electrons backscattered from lead has been profusely studied. To quantify this dose enhancement effect, an electron backscatter factor (EBF) wasdefined as the ratio of dose at the tissue-inhomogeneity interface with and without the scatterer present. The dependence of the EBF on energy at the scatterer surface is not well known for energies lower than 3 MeV which is the most frequent clinical situation. In this work, we have done Monte Carlo calculations with the GEANT code to study EBF in lead at this energy range. The applicability of this code and the developed procedure for dose estimation has been experimentally verified. The dependence of the EBF on the beam energy incident on the scatterer has been studied for different nominal beam energies incident at the phantom's surface. The results show a trend of increase of EBF with the beam energy incident on the ...

2000-07-01

440

Can a model-independent analysis be made for the matter distribution of "4"0Ca from 166 MeV #alpha# particle scattering  

International Nuclear Information System (INIS)

It is proposed to extract, independently of any nuclear model, the "4"0Ca matter density from an analysis of the elastic scattering of "1"6"6 MeV alpha particles. The scattering is described using an optical potential whose real part is evaluated by folding the matter density with a nucleon-alpha interaction. Following the procedure proposed by Sick (Nucl. Phys. A; 218: 509 (1974)) and Phys. Lett.; 44B; 62 (1975)) for the analysis of electron scattering data, the density is represented by a sum of gaussians whose amplitudes are deduced in fitting, via a chi"2 minimization, the experimental cross section data. This method determines the envelope of densities for different parameters of gaussians: width, spacing. The envelope of the moments of these densities are presented and the root-mean-square radius is extracted. It is concluded that only the nuclear surface is well studied by the alpha particle ...

441

A study of the effects of scattered radiation on radiographic quality and methods of elimination of such radiation  

International Nuclear Information System (INIS)

Many mechanical parts are subjected to stresses and strains that may eventually lead to their failure. In order to prevent the costly delays associated with equipment down-time, many parts have to be tested for weaknesses and defects when machinery is constructed or dismantled for maintenance. These procedures are known as Non-Destructive Testing (NDT) methods. Five types of non-destructive testing methods routinely used are radiographic testing, ultrasonic testing, magnetic particle inspection, liquid penetrant testing and eddy current testing. Out of these five techniques industrial radiography plays an important role in non-destructive testing to reveal interior defects in materials. In radiography almost two-thirds of the radiation reaching the film is scattered radiation which does not form the image of defects. Scattered radiation generated inside and outside a material has a very large effect on sensitivity of flaw detection since it ...

1998-02-01

442

A study of the projectile break-up mechanism at intermediate energies by means of the multidetector ARGOS  

Energy Technology Data Exchange (ETDEWEB)

The reaction mechanism underlying the 44 MeV/u {sup 40}Ar projectile break-up process has been studied on different targets, by measuring the coincidences between light particles or intermediate mass fragments detected in a large angular range, and projectile fragments or light charged particles. While the experimental data relative to projectile-like fragments (PLF) with charge close to the one of the projectile can be interpreted in the framework of a three source analysis, the anomalous light fragment production with Z {<=} 10 rather suggests `fission` as one of the possible decay mode of the highly excited projectile or PLF. It is also observed that a great amount of the forward detected light charged particles are correlated, and due to the break-up or decay of light excited ions. (author). 9 refs.

1996-09-01

443

ZZ MCJEF22NEA.BOLIB, MCNP Cross Section Library Based on JEF-2.2  

International Nuclear Information System (INIS)

1 - Description or function: Continuous energy cross-section data library for the Monte Carlo program MCNP based on the JEF-2.2 evaluated nuclear data library (ACE Format). Format: ACE Number of groups: Continuous energy Nuclides (107): H-1, H-2, He-4, Li-6, Li-7, Be-9, B-10, B-11, C-nat, N-14, N-15, O-16, O-17, F-19, Na-23, Mg-nat, Al-27, Si-nat, Cl-nat, Ti-nat, Cr-50, Cr-52, Cr-53, Cr-54, Mn-55, Fe-54, Fe-56, Fe-57, Fe-58, Co-59, Ni-58, Ni-60, Ni-61, Ni-62, Ni-64, Zr-90, Zr-91, Zr-92, Zr-94, Zr-96, Zr-nat, Nb-93, Mo-92, Mo-94, Mo-95, Mo-96, Mo-97, Mo-98, Mo-100, Mo-nat, Tc-99, Ru-101, Ru-102, Ru-104, Rh-103, Pd-105, Pd-107, Ag-109, I-129, Xe-131, Cs-133, Pr-141, Nd-143, Nd-145, Pm-147, Sm-147, Sm-149, Sm-150, Sm-151, Sm-152, Eu-153, Gd-154, Gd-155, Gd-156, Gd-157, Gd-158, Gd-160, Hf-174, Hf-176, Hf-177, Hf-178, Hf-179, Hf-180, Pb-nat, Bi-209, Th-232, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-239bis, Pu-240, Pu-241, Pu-242, Am-241, Am-242, Am-242m, Am-243, Cm-242, Cm-243, ...

444

ZZ MCB63NEA.BOLIB, MCNP Cross Section Library Based on ENDF/B-VI Release 3  

International Nuclear Information System (INIS)

1 - Description of program or function: Continuous energy cross-section data library for the Monte Carlo program MCNP based on the ENDF/B-VI Release 3 evaluated nuclear data library (ACE Format). Format: ACE; Number of groups: Continuous energy; Nuclides (107): H-1, H-2, He-4, Li-6, Li-7, Be-9, B-10, B-11, C-nat, N-14, N-15, O-16, O-17, Na-23, Mg-nat, Al-27, Si-nat, Cl-nat, Ti-nat, Cr-50, Cr-52, Cr-53, Cr-54, Mn-55, Fe-54, Fe-56, Fe-57, Fe-58, Co-59, Ni-58, Ni-60, Ni-61, Ni-62, Ni-64, Zr-90, Zr-91, Zr-92, Zr-94, Zr-96, Zr-nat, Nb-93, Mo-94, Mo-95, Mo-96, Mo-97, Mo-nat, Tc-99, Ru-101, Ru-102, Ru-104, Rh-103, Pd-105, Pd-107, Ag-109, I-129, Xe-131, Cs-133, Pr-141, Nd-143, Nd-145, Pm-147, Sm-147, Sm-149, Sm-150, Sm-151, Sm-152, Eu-153, Gd-154, Gd-155, Gd-156, Gd-157, Gd-158, Gd-160, Hf-174, Hf-176, Hf-177, Hf-178, Hf-179, Hf-180, Hf-nat, Pb-206, Pb-207, Pb-208, Bi-209, Th-232,U-233, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-242, Am-242m, Am-243, ...

445

Toward a 2D SPH Multiphysic Code with Solid-Solid & Fluid Interactions for Industrial Related Problems  

CERN Document Server

In the present study, applications of the SPH method to industrial related issues are considered by starting from an existing open source 2D SPH code, namely the SPHYSICS code, which offers an effective ground for numerical developments, which are performed in order to bring an answer to industrial problems, such as simulations of solid/fluid coupling in a free surface flow context. The purpose of the present paper is therefore to expose the numerical developments which yield an enhanced version (referred to as "SPHYSIC2") of the initial code. Firstly, the different features added to obtain the operational code needed for engineering applications are described, and so are the problems raised on this way, offering a kind of review of SPH methods for engineers. Secondly, the validation of the proposed code is partially presented with two well known but difficult test cases, namely the classical "dam break" and "wedge entry" problems. Thirdly, ...

2010-01-01

446

Study on seismic stability of seawall in man-made island. Pt. 4. Deformation analysis of seawall during earthquake by DEM-FEM coupled analysis method (SEAWALL-2D)  

Energy Technology Data Exchange (ETDEWEB)

In the development of the man-made island siting technology of nuclear power plants, assessing the stability of the seawall against large ocean waves and earthquakes is indispensable. Concerning with the seismic stability of the seawall, prediction of the deformation like sliding and settlement of the seawall during earthquake including the armour units in front of the caisson becomes important factor. For this purpose, the authors have developed the two-dimensional DEM-FEM coupled analysis method (SEAWALL-2D) to predict the deformation of the seawall covered with the armour units during earthquake. In this method, movements of the armour units are calculated in DEM analysis part and deformation of the caisson, rubble moundsand seabed and back fill are calculated in FEM analysis part taking the nonlinearity of the soil materials based on the effective stress into account. Numerical simulations of dynamic centrifuge model tests of the seawall ...

1999-02-01

447

Spectrally condensed fluid turbulence and L-H transitions in plasma  

International Nuclear Information System (INIS)

Recent experimental and theoretical studies of two-dimensional (2D) turbulence reveal that spectrally condensed turbulence which is a system of coupled large-scale coherent flow and broadband turbulence, is similar to plasma turbulence near the L-H transition threshold. Large condensate vortices fed via the turbulent inverse energy cascade, can control both the level of the broadband turbulence by shear decorrelation, and the energy injected into turbulence at the forcing scale via sweeping of the forcing-scale vortices. The interaction between these ingredients of spectrally condensed fluid turbulence is in many aspects similar to the interactions in the zonal flow-GAMs-turbulence system in plasma. In this paper we overview recent results on condensed 2D turbulence and present evidence of interaction between its three components: condensate structures, turbulence and forcing-scale vortices. This is ...

2009-06-01

448

Ovariectomy-induced changes in aged beagles : histomorphometry of rib cortical bone.  

Energy Technology Data Exchange (ETDEWEB)

Bone loss associated with estrogen depletion is well documented in cancellous bone but less well characterized in cortical bone. The effects of ovariectomy on the aged beagle skeleton were studied by histomorphometric analysis of the cortical bone in sequential rib biopsies. Biopsies were taken from each ovariectomized or sham-operated dog at the time of surgery and at 1, 4, and 8.5 months after surgery. Just prior to each postoperative biopsy, tetracycline, calcein, and xylenol orange, respectively, were administered by a fluorochrome labeling procedure (2d-10d-2d) to provide markers of bone formation. Analysis of sequential rib biopsies provided a means to follow the ovariectomy response over time and to compare each animal against its own baseline. Though ovariectomy did not influence histomorphometric indices at 1 month after surgery, a transient increase in cortical bone formation occurred ...

1998-03-01

449

OPTICAL FIBRE ARRAY MANUFACTURE (OFAM)  

Environmental Research Database

Objectives1. The study of the automatic alignment of electrically charged optical fibres.~%~~%~2. The design and construction of a prototype system for assembly of the fibres.~%~~%~3. The fabrication of a proof-of-principle 4-by-4 fibre array.~%~~%~4. The test and characterisation of the prototype fibre bundle in terms of translational and angular positioning accuracy.~%~~%~5. A paper design of a full-scale automated system.~%~~%~6. Enable commercial exploitation.~%~DescriptionThis multidisciplinary programme aims to investigate and develop an 'adventurous' process for manufacturing 2-D optical fibre arrays, with at least an order of magnitude improvement in the positional and angular tolerances of the mono-mode fibres compared to conventional techniques. Manufacturable, dense 2-D optical fibre arrays are essential ...

2002-01-31

450

L'exercice physique d'endurance est plus efficace que l'exercice aerobie pour le controle par la pression arterielle sur 24heures chez des diabetiques de type 2  

British Library Electronic Table of Contents (United Kingdom)

Aim: The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise. Methods: Ten adults with T2D (age: 55.8+/-7.7 years; weight: 79.4+/-14.0kg; fasting glucose: 133.0+/-36.7mg.dL^-^1) underwent: (1) AER: 20min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO2, respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interve...

2011-01-01

451

Investigation of local-dimensional galvanic distortion on MT data in the central part of Northeastern Japan; Tohoku chiho no MT data ni mirareru kyokushoteki sanjigensei no eikyo  

Energy Technology Data Exchange (ETDEWEB)

Groom-Bailey decomposition analysis was carried out to investigate regional 3-D galvanic distortion on MT data in the central part of Northeastern Japan. Measuring sites were located nearly along the east-west line crossing Northeastern Japan. Three measuring lines (A, B, C) from the north to the south were prepared, and only data on the C line were analyzed in this paper. As a result, twist and shear were estimated to be not zero depending on local distortion in most of the sites. It was thus clarified that this method is not always perfect. This method was effective for regional 2-D structures, however, its application was doubtful to complicated 3-D underground structures in Japan. In order to obtain more accurate results, 2-D analysis using the impedance including no local distortion effect was necessary after the preliminary Groom-Bailey decomposition analysis. The direction of the wide area ...

1996-10-01

452

Influence of Ce0.9Gd0.1O2-d particles on microstructure and oxygen permeability of Ba0.5Sr0.5Co0.8Fe0.2O3-d composite membrane  

British Library Electronic Table of Contents (United Kingdom)

This study examined the oxygen permeation behavior of Ce0.9Gd0.1O2-d (Gadolinium-Doped Ceria, GDC)/Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF) composite membranes fabricated using a conventional sintering technique. GDC/BSCF composite membranes with a relative density >95% could be obtained when a green compact of BSCF and GDC was sintered at 1150^oC for 5h. It appears that GDC serves as a grain growth inhibitor because the average grain size of the composite decreased with increasing GDC content. The oxygen permeability of the BSCF and GDC/BSCF composite membranes strongly depends on the grain size and membrane thickness. The addition of GDC to BSCF resulted in a small grain size, low thermal expansion coefficient and high hardness. However, it is believed that oxygen permeation was blocked by GDC, a...

2010-01-01

453

How initial and boundary conditions affect protoplanetary migration in a turbulent sub-Keplerian accretion disc: 2D SPH simulations  

CERN Document Server

Current theories on planetary formation establish that giant planet formation should be contextual to their quick migration towards the central star due to the protoplanets-disc interactions on a timescale of the order of $10^5$ years, for objects of nearly 10 terrestrial masses. Such a timescale should be smaller by an order of magnitude than that of gas accretion onto the protoplanet during the hierarchical growing-up of protoplanets by collisions with other minor objects. These arguments have recently been analysed using N-body and/or fluid-dynamics codes or a mixing of them. In this work, inviscid 2D simulations are performed, using the SPH method, to study the migration of one protoplanet, to evaluate the effectiveness of the accretion disc in the protoplanet dragging towards the central star, as a function of the mass of the planet itself, of disc tangential kinematics and of the presence of a planet ``pseudo-atmosphere''. To this ...

2009-01-01

454

Histamine Molecule and Dianion Oxalate are Efficient Blocks for Building 2D Supramolecular Networks  

British Library Electronic Table of Contents (United Kingdom)

One salt and two Cu(II) complexes (H2hsm)(ox), 1, [Cu(hsm)(ox)], 2, and [Cu(hsm)(ox)H2O], 3, have been synthesized and X-ray characterized (hsm is histamine and ox2? is the oxalate dianion). Starting from the prochiral tetracoordinated complex 2, pentacoordinated complex 3 crystallizes as a racemic mixture of the enantiomeric ? and ? isomers, in space group P21/c. In all cases, the side chain of the hsm group is gauche, allowing the formation of strong hydrogen bonds in the salt 1, and to chelate the metal center in complexes 2 and 3. The combination hsm/ox seems to favor the formation of 2D supramolecular structures (planes or wavy planes), through efficient networks of N?H???O hydrogen bonds. Cell parameters: 1, P21/c, a?=?6.260 (2) ?, b?=?11.500 (4) ?, c?=?12.525 (4) ?, ??=?104.047 (17)...

2011-01-01

455

Gas and stellar dynamics in NGC 1068. Probing the galactic gravitational potential  

CERN Document Server

We present Sauron 2D spectrography of the central 1.5 kpc of the nearby Sey2 galaxy NGC1068, encompassing the well-known NIR inner bar. We have successively disentangled the respective contributions of the ionized gas and stars, thus deriving their 2D distribution and kinematics. The [OIII] and Hbeta emission lines exhibit very different spatial distribution and kinematics, the latter following inner spiral arms with clumps associated with star formation. Strong inwards streaming motions are observed in both the Hbeta and [OIII] kinematics. The stellar kinematics also exhibit clear signatures of a non-axisymmetric tumbling potential, with a twist in both the velocity and h3 fields. We re-examined the long-slit data of Shapiro et al (2003) using pPXF: a strong decoupling of h3 is revealed, and the central decrease in h4 hinted in the Sauron data is confirmed. These data also suggest that NGC1068 is a ...

2006-01-01

456

Functional MRI of the pharynx in obstructive sleep apnea (OSA) with rapid 2-D flash sequences  

International Nuclear Information System (INIS)

Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager ('Vision', Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of ...

457

Expression of cyclin D{sub 1} during endotoxin-induced aleveolar type II cell hyperplasia in rat lung and the detection of apoptotic cells during the remodeling process  

Energy Technology Data Exchange (ETDEWEB)

Our studies have shown that endotoxin intratracheally instilled into the rat lung induces proliferation of alveolar type II cells. In that study, the alveolar type II cells. In that study, the alveolar type II cell hyperplasia occurred 2 d after instillation of endotoxin and persisted for a further 2 d. After hyperplasia, the lung remodeled and returned to a normal state within 24-48 h. Understanding the mechanisms involved in the remodeling process of this transient hyperplasia may be useful to identify molecular changes that are altered in neoplasia. The purpose of the present study was to corroborate induction of epithelial cell hyperplasia by endotoxin and to delineate mechanisms involved in tissue remodeling after endotoxin-induced alveolar type II cell hyperplasia. In conclusion, immonostaining with cyclin D1 and cytokeratin shows that endotoxin induced epithelial cell proliferation and resulted ...

1995-12-01

458

Excitation cross sections of Cd"+ ions for the upper and lower states of the Cd II 441.6-nm laser line by electron impact  

International Nuclear Information System (INIS)

The excitation cross sections by electron impact from the Cd II ground state to the laser upper state 5s_2 _2D/sub 5/2/ (Beutler state) and the laser lower state 5p _2P/sub 3/2/ (resonance state) have been measured by using a crossed-beam method of electrons and Cd"+ ions and a photon-counting method. The electron-energy region investigated was from the threshold energy (5.8 eV) for the excitation of the 5p _2P/sub 3/2/ state to 20 eV. It has been shown that the excitation cross section for the ionic Beutler state 5s_2 _2D/sub 5/2/ is of the order of 10"-_1_5 cm_2 and has a sharp peak near the threshold energy for the excitation. The excitation cross section for the resonance state 5p _2P/sub 3/2/ has also been of the order of 10"-_1_5 cm_2 and has a relatively broad maximum.

459

Enhanced defect detection and sizing accuracy using matrix phased array ultrasonic tools  

Energy Technology Data Exchange (ETDEWEB)

Although ultrasonic testing inspection technology and tools have improved significantly, there is still a need for more reliable detection, monitoring, and accurate sizing of crack-like and planar defects, complex corrosion damage, and detection of secondary features within deformed pipe. Ultrasonic two dimensional (2D) matrix phased array technology offers some unique advantages that make the technology promising for improving detection and sizing of pipeline flaws resulting from welding or from in-service damage. Ultrasonic modeling and simulation has been conducted to evaluate the detection and sizing capabilities of 2D matrix arrays for various pipeline inspection concepts. Simulations have been performed using both flexible and rigid array probes. Inspection concepts using rigid probes were evaluated for inspections from both the outside and inside pipe surfaces, while flexible probes were ...

2009-07-01

460

Durability of bare and anodised aluminium in atmosphere of very different corrosivities I. Bare aluminium; Durabilidad del aluminio desnudo y anodizado en atmosferas de muy diferentes corrosividades. I. Aluminio desnudo  

Energy Technology Data Exchange (ETDEWEB)

The behaviour of bare aluminium is studied in atmospheric exposure at 11 natural testing stations with salinity levels ranging between 2.1 and 684 mg Cl''- m''-2 d''-1. In atmospheres of low or moderate aggressivity aluminium behaves as a passive material, though the insignificant corrosion that is produced is sufficient to spoil its appearance. In contrast, at salinity levels of 50 mg Cl''- m''-2 ''-1 or above, aluminium is susceptible to pitting corrosion even in the first year of atmospheric exposure, or in the second year at salinities of {<=} 10 mg Cl''- m''-2 d''-1. For comparative purposes, results are included for aluminium protected with an anodic film of 28 {mu}m thickness exposed at the same testing stations. A 28 {mu}m anodic ...

2004-07-01

461

Constituents of fruit pulp of Maytenus salicifolia and complete 1D/2D NMR data of 3?-hydroxy-D:B-friedo-olean-5-ene  

British Library Electronic Table of Contents (United Kingdom)

A mixture of long-chain hydrocarbons constituted by nonacosane (29C, 7.5%), hentriacontane (31C, 48.3%), and tritriacontane (33C, 30.1%), the ester 1?-acetyloxymethylpentacosa-20?-enyl 10-hydroxydecanoate (2), ?-amyrin (3), friedelin (4), and lupeol (5), and 3?-hydroxy-D:B-friedo-olean-5-ene (6) were identified as constituents of fruits of Maytenus salicifolia Reissek (Celastraceae). The structural formula and the stereochemistry of compound 6 were established by the data obtained through 1H and 13C NMR spectroscopy, including DEPT-135 and 2D (HMQC, HMBC, and NOESY) experiments. By analysis of the spectral data, it was possible to correct seven chemical shift assignments of compound 6, which were erroneous attributed and published in the scientific literature.

2010-01-01

462

CFD analysis on the flow distribution of steam generator of SMART-P  

Energy Technology Data Exchange (ETDEWEB)

The Computational Fluid Dynamics(CFD) study was conducted to assess the new design concept introduced to solve the issues on the flow deviation between SG cassettes and the supporting structure design of the flow distributing plate subjected to the flow induced vibration. Flow field from MCP to the bottom of SG was modeled for 2-dimensional(2D) CFD analysis and then sensitivity analysis on major design parameters was conducted using commercial CFD code, Fluent. The cases for detailed 3D analysis were selected based on the result of 2D analysis and the detailed 3-dimensional(3D) analysis was conducted for these selected cases using Fluent code. Flow field was modeled by RNG model and wall function, 2nd upwind scheme, porous model, structured or hybrid grid. The analysis result shows that the maximum deviation of flow distribution between SG cassettes was reduced upto about 0.1% and the pressure loss from ...

2003-12-01

463

Blending of nanoscale and microscale in uniform large-area sculptured thin-film architectures  

CERN Document Server

The combination of large thickness ($>3$ $\\mu$m), large--area uniformity (75 mm diameter), high growth rate (up to 0.4 $\\mu$m/min) in assemblies of complex--shaped nanowires on lithographically defined patterns has been achieved for the first time. The nanoscale and the microscale have thus been blended together in sculptured thin films with transverse architectures. SiO$_x$ ($x\\approx 2$) nanowires were grown by electron--beam evaporation onto silicon substrates both with and without photoresist lines (1--D arrays) and checkerboard (2--D arrays) patterns. Atomic self--shadowing due to oblique--angle deposition enables the nanowires to grow continuously, to change direction abruptly, and to maintain constant cross--sectional diameter. The selective growth of nanowire assemblies on the top surfaces of both 1--D and 2--D arrays can be understood and predicted using simple geometrical shadowing ...

2003-01-01

464

Atmospheric lifetimes and ozone depletion potentials of methyl bromide (CH3Br) and dibromomethane (CH2Br2)  

Energy Technology Data Exchange (ETDEWEB)

The rate coefficients for the reactions of OH radical with CH3Br and CH2Br2 were measured as functions of temperature using the laser photolysis - laser induced fluorescence method. This data was incorporated into a semiempirical model (Solomon et al., 1992) and a 2D model to calculate the steady-state ozone depletion potentials (ODP) and atmospheri lifetimes, tau, with greatly improved accuracy as compared to earlier studies. The calculated ODPs and tau are 0.65 and 1.7 years and 0.17 and 0.41 years for CH3Br and CH2Br2, respectively, using the semiempirical model. These lifetimes agree well with those calculated using a 2D model. This study better quantifies the ODPs and tau of these species which are needed inputs for discussion of possible regulation of human emissions currently under international considerations. 29 refs.

1992-10-01

465

Research and development of photovoltaic power system. Study on structural defects in silicon-based amorphous materials; Taiyoko hatsuden system no kenkyu kaihatsu. Amorphous silicon kei zairyo no kozo kekkan ni kansuru kenkyu  

Energy Technology Data Exchange (ETDEWEB)

Described herein are the results of the FY1994 research program for structural defects of silicon-based amorphous materials for solar cells. The study on light generation defects of the a-Si:H system and rejuvenation process by annealing establishes the effects of light irradiation time on changed neutral dangling bond density as a result of light irradiation at varying temperature of 77K, room temperature and 393K. The study on annealing to rejuvenate light generation defects of various types of a-Si-H systems establishes the activation energy distribution with respect to annealing to remove light-induced defects, showing that hydrogen affects the distribution of light-induced defects. The study on decaying process of light-induced ESR for undoped and N-doped a-Si:H systems observes the decaying process of light-induced ...

1994-12-01

466

[Experimental and kinetic modeling of acid/base and redox reactions over oxide catalysts  

Energy Technology Data Exchange (ETDEWEB)

The research has involved the characterization of catalyst acidity, [sup 2]D NMR studies of Bronsted acid sites, and kinetic, calorimetric, and spectroscopic studies of methylamine synthesis and related reactions over acid catalysts. Approach of this work was to explore quantitative correlations between factors that control the generation, type, strength, and catalytic properties of acid sites on zeolite catalysts. Microcalorimetry, thermogravimetric analysis, IR spectroscopy, and NMR spectroscopy have provided information about the nature and strength of acid sites in zeolites. This was vital in understanding the catalytic cycles involved in methylamine synthesis and related reactions over zeolite catalysts.

1993-01-01

467

The rare earth antimonates: spectroscopic properties, crystal field and paramagnetic susceptibility simulations  

Energy Technology Data Exchange (ETDEWEB)

The rare earth antimonates RE{sub 3}Sb{sub 5}O{sub 12} constitute an isostructural series, where the rare earth site symmetry is S{sub 4}. The spectroscopic properties of pure or doped compounds of this family are studied in order to derive their energy level schemes and to simulate them through the crystal field theory, by using the approximated D{sub 2d} potential. The paramagnetic susceptibilities are calculated with the derived wavefunctions and compared to experiment.

1991-01-01

468

Surface doping of conjugated polymers by graphene oxide and its application for organic electronic devices  

Energy Technology Data Exchange (ETDEWEB)

Surface doping of conjugated polymers is realized by depositing a thin layer of graphene oxide (GO) on top of the polymers. The high proton density and the unique 2D structure of GO facilitate the protonic surface doping of conjugated polymers to achieve high conductivities. This finding represents a new strategy for improving charge transport across the metal/conjugated polymer interface to achieve much improved performance in organic solar cells. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

2011-04-26

469

Submonolayer nucleation and growth and the initial stage of multilayer kinetic roughening during Ag/Ag (100) homoepitaxy  

Energy Technology Data Exchange (ETDEWEB)

A comprehensive Scanning Tunneling Microscopy (STM) study of submonolayer nucleation and growth of 2D islands in Ag/Ag(100) homoepitaxy for temperature between 295K and 370K is presented. The initial stages of multilayer kinetic roughening is also studied. Analysis of an appropriate model for metal (100) homoepitaxy, produces estimates of 350 meV for the terrace diffusion barrier, 400 meV for the adatom bond energy, and 25 meV for the additional Ehrlich-Schwoebel step-edge barrier.

1996-08-01

470

Spiral Structure in IP Peg Confronting Theory and Observations  

CERN Document Server

Steeghs et al. (1997) have found the first convincing evidence for spiral structure in the accretion disc in IP Pegasi. We perform two kinds of 2D hydrodynamic simulations, a SFS finite volume scheme and a SPH scheme, in the case of mass ratio of 0.5. Both results agree well each other. We construct the Doppler maps and line flux-binary phase relation based on the density distributions. Both of our results agree well with those obtained by the observation.

1998-01-01

471

Spiral CT with three-dimensional and multiplanar reconstruction in the diagnosis of anterior chest wall joint and bone disorders  

Energy Technology Data Exchange (ETDEWEB)

Twenty-seven patients with symptoms or clinical findings suggesting joint or bone disorders of the anterior chest wall (ACW) were evaluated by spiral CT with 3-dimensional (3-D) and multiplanar reconstructions. Preceding conventional ACW tomography was performed in 10 patients. ACW joint and bone changes were visualized more adequately by coronal 2-D reconstructions based on spiral CT than by conventional tomography. In addition, nonossified costal cartilages and soft tissue lesions were demonstrated. 3-D reconstructions sometimes added information, especially in patients with fracture and dislocation. (orig.).

1994-09-01

472

Simulation of concrete perforation based on a continuum damage model  

Energy Technology Data Exchange (ETDEWEB)

Numerical simulation of dynamic fracture of concrete slabs, impacted by steel projectiles, was carried out in this study. The concrete response was described by a continuum damage model. This continuum damage model was originally developed to study rock fragmentation and was modified in the present study with an emphasis on the post-limit structural response. The model was implemented into a transient dynamic explicit finite element code LS-DYNA2D and the code was then used for the numerical simulations. The specific impact configuration of this study follows the experiment series conducted by Hanchak et al. Comparisons between calculated results and measured data were made. Good agreements were found.

1994-10-01

473

Reverse time migration in tilted transversely isotropic media  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a reverse time migration (RTM) method for the migration of shot records in tilted transversely isotropic (TTI) media. It is based on the tilted TI acoustic wave equation that was derived from the dispersion relation. The RTM is a full depth migration allowing for velocity to vary laterally as well as vertically and has no dip limitations. The wave equation is solved by a tenth-order finite difference scheme. Using 2D numerical models, we demonstrate that ignoring the tilt angle will introduce both lateral and vertical shifts in imaging. The shifts can be larger than 0.5 wavelength in the vertical direction and 1.5 wavelength in the lateral direction.

2004-07-01

474

Perturbing the ground ring of 2D string theory  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the authors use free field techniques in D = 2 string theory t calculate the perturbation of the special state algebras when the cosmological constant is turned on. In particular, the authors find that the 'ground cone' preserved by the ring structure is promoted to a three-dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1,1) current algebra of moduli deformations is computed completely, and no simple geometrical interpretation is found. The authors also quote some facts concerning the Liouville matrix a model dictionary in this class of theories.

1992-12-10

475

Particle-hole excitations in N=50 nuclei  

Energy Technology Data Exchange (ETDEWEB)

Energy levels in N=50 nuclei are calculated allowing single-particle excitations from the p{sub 1/2} and g{sub 9/2} shells into the d{sub 5/2}, s{sub 1/2}, d{sub 3/2}, and g{sub 7/2} shells. Important parts of the interaction are determined by least-squares fits to known levels. Agreement with experiment is very good. The high-spin particle-hole states appear to be mainly yrast levels in mass 93 and higher, but are not in {sup 90}Zr. {copyright} {ital 1997} {ital The American Physical Society}

1997-03-01

476

On the 2D Cahn-Hilliard equation with inertial term  

CERN Document Server

P. Galenko et al. proposed a modified Cahn-Hilliard equation to model rapid spinodal decomposition in non-equilibrium phase separation processes. This equation contains an inertial term which causes the loss of any regularizing effect on the solutions. Here we consider an initial and boundary value problem for this equation in a two-dimensional bounded domain. We prove a number of results related to well-posedness and large time behavior of solutions. In particular, we analyze the existence of bounded absorbing sets in two different phase spaces and, correspondingly, we establish the existence of the global attractor. We also demonstrate the existence of an exponential attractor.

2008-01-01

477

Mechanisms of high-T/sub c/ superconductivity in low-dimensional materials  

Energy Technology Data Exchange (ETDEWEB)

High-T/sub c/ superconductivity is due to the action of two mechanisms: (1) plasmon mechanism, i.e., exchange of two-dimensional (2-D) plasmons and (2) strong electron--phonon coupling. The low dimensionality and the small value of the carrier concentration make the plasmon mechanism favorable. The small value of the coherence length leads to a unique opportunity to observe a multigap structure. The proximity effect can be used in order to increase T/sub c/ of A-15 compounds.

1987-11-01

478

Interest of a two-dimensional matrix of detectors for the quality control of beams in static or dynamic mode; Interet d'une matrice bidimensionnelle de detecteurs pour le controle de qualite des faisceaux en mode statique ou dynamique  

Energy Technology Data Exchange (ETDEWEB)

A 2D matrix allows a fairly rapid verification of irradiation parameters transferred on computer processing equipment without expanding the dosimetry means to implement. Associated to 'Multicheck and Verisoft' software it will handle some of the regulatory recommendations of the A.F.S.S.A.P.S. for quality control of accelerators and ensure the traceability of testing carried out. (N.C.)

2007-11-15

479

Evaluation of Townsend's first ionization and attachment coefficients from prebreakdown current measurements  

International Nuclear Information System (INIS)

Hitherto in this laboratory, ionization coefficients alpha and attachment coefficients #eta# have been determined from Townsend's discharge experiments by a curve-fitting method. However, the method proved to be laborious, Formulae have been derived in this paper to give value of alpha and #eta# as a function of Isubo, Isub1 and Isub2 where Isubo is the photoelectric current at a gap setting d and Isub2 the current at another gap setting 2 d. The values of alpha and #eta# obtained give currents in agreement to within 3% in the best cases with the observed currents.

480

Chemical constituents of Galianthe brasiliensis (Spreng.) E.L.Cabral and Bacigalupo (Rubiaceae)  

International Nuclear Information System (INIS)

This paper describes the chemical constituents isolated from aerial parts of the plant Galianthe brasiliensis. From a methanol extract, the iridoid glycosides asperuloside, deacetylasperuloside, mixture of Z- and E-6-O-p-coumaroylscandoside methyl ester, the triterpene ursolic acid and the steroids stigmasterol, campesterol, b-sitosterol and 3-O-b-glucopyranosyl sitosterol were isolated. The structures of the natural products were identified on the basis of spectral data, including 2D NMR experiments. The antiproliferative properties of the crude methanolic extract were investigated against a series of nine human cancer cell lines. (author)

481

Advances in imaging THGEM-based detectors  

International Nuclear Information System (INIS)

We report on recent measurements with Thick GEM-like (THGEM)-based imaging detectors. The THGEM is a robust gaseous electron multiplier similar to GEM but with larger dimensions. It has high electron multiplication, of 105 and 107 in single- and double-THGEM structure, respectively, fast signals and ?10MHz/mm2 counting rate capability. It can be produced in any shape and over large area. In view of many possible applications of THGEM-based imaging detectors, in particle physics and beyond, we have recently studied the localization properties of a 2D 10x10cm2 detector. The results of these studies are presented.

2007-03-01

482

A combinatorial spanning tree model for knot Floer homology  

CERN Document Server

We iterate Manolescu's unoriented skein exact triangle in knot Floer homology with coefficients in the fraction field of the group ring (Z/2Z)[Z]. The result is a spectral sequence which converges to a stabilized version of delta-graded knot Floer homology. The (E_2,d_2) page of this spectral sequence is an algorithmically computable chain complex expressed in terms of spanning trees, and we show that there are no higher differentials. This gives the first combinatorial spanning tree model for knot Floer homology.

2011-01-01

483

&C:sIC> uC%m$C C(k6C* 1CFM 2dC% !C3U J*C0! CV$,Co\\ lC$\\JC ...  

Science.gov (United States)

C C*R C" dC*9 4hC2 CX2VCTF CK/XCL` CCNA C?Q C.:FC C?v As1)Ax^IA} AyU$ =FA%WNA AfgJA Aw;ZAzg AyA!A A=!nA> CA!n/A* ? ...

484

Synopsis of some preliminary computational studies related to unsaturated zone transport at Area G  

Energy Technology Data Exchange (ETDEWEB)

Computational transport models are described with applications in three problem areas related to unsaturated zone moisture movement beneath Area G. These studies may be used to support the ongoing maintenance of the site Performance Assessment. The three areas include: a 1-D transient analysis with average tuff hydraulic properties in the near surface region with computed results compared to field data; the influence on near surface transient moisture percolation due to realistic distributions in hydraulic properties derived statistically from the observed variance in the field data; and the west to east moisture flow in a 2-D steady geometry approximation of the Pajarito Plateau. Results indicate that a simple transient model for transport of moisture volume fraction fits field data well compared to a moisture pulse observed in the active disposal unit, pit 37. Using realistic infiltration boundary conditions for summer showers and for spring ...

1998-03-01

485

Depth migration in transversely isotropic media with explicit operators  

Energy Technology Data Exchange (ETDEWEB)

The author presents and analyzes three approaches to calculating explicit two-dimensional (2D) depth-extrapolation filters for all propagation modes (P, SV, and SH) in transversely isotropic media with vertical and tilted axis of symmetry. These extrapolation filters are used to do 2D poststack depth migration, and also, just as for isotropic media, these 2D filters are used in the McClellan transformation to do poststack 3D depth migration. Furthermore, the same explicit filters can also be used to do depth-extrapolation of prestack data. The explicit filters are derived by generalizations of three different approaches: the modified Taylor series, least-squares, and minimax methods initially developed for isotropic media. The examples here show that the least-squares and minimax methods produce filters with accurate extrapolation (measured in the ability to ...

1994-12-01

486

A Fast Parallel Algorithm for Selected Inversion of Structured Sparse Matrices with Application to 2D Electronic Structure Calculations  

Energy Technology Data Exchange (ETDEWEB)

We present an efficient parallel algorithm and its implementation for computing the diagonal of $H^-1$ where $H$ is a 2D Kohn-Sham Hamiltonian discretized on a rectangular domain using a standard second order finite difference scheme. This type of calculation can be used to obtain an accurate approximation to the diagonal of a Fermi-Dirac function of $H$ through a recently developed pole-expansion technique \\cite{LinLuYingE2009}. The diagonal elements are needed in electronic structure calculations for quantum mechanical systems \\citeHohenbergKohn1964, KohnSham 1965,DreizlerGross1990. We show how elimination tree is used to organize the parallel computation and how synchronization overhead is reduced by passing data level by level along this tree using the technique of local buffers and relative indices. We analyze the performance of our implementation by examining its load balance and communication overhead. We show that our implementation ...

2009-09-25

487

Estimate of the scatter component in SPECT  

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

488

Transverse Imaging of the Proton in Exclusive Diffractive pp Scattering  

Energy Technology Data Exchange (ETDEWEB)

In a forthcoming paper we describe a new approach to rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, Higgs, etc.) in exclusive double-gap diffractive pp scattering, pp -> p + H + p. It is based on the idea that hard and soft interactions are approximately independent (QCD factorization), and allows us to calculate the RGS probability in a model-independent way in terms of the gluon generalized parton distributions (GPDs) in the colliding protons and the pp elastic scattering amplitude. Here we focus on the transverse momentum dependence of the cross section. By measuring the ''diffraction pattern'', one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton from the data.

2006-04-20

489

The spatial distribution of argon clusters in gas jet  

International Nuclear Information System (INIS)

The spatial distribution of argon clusters in gas jet is tested using the Rayleigh scattering method. A pulsed laser is used to acquire the whole evolution of the cluster inside one event. The measured results at a fixed axial position show that the argon clusters grow in less than one millisecond after the nozzle is opened and the cluster size keeps constant during the whole open period of 20 ms. Further results show that the scattering signal along the radial direction is almost Gaussian-distributed and the full width half maximum (FWHM) increases almost linearly when the distance from nozzle increases. The scattering signal along the axial direction is Landau-distributed and the area near the nozzle is most effective for laser cluster interaction. (authors)

2010-02-01

490

The microscopic dynamics of condensed parahydrogen  

Energy Technology Data Exchange (ETDEWEB)

We have measured the almost-pure incoherent scattering function of liquid and solid parahydrogen, using inelastic neutron scattering. The experiments were carried out on TOSCA, a time-of-flight, inverse-geometry, crystal-analyzer spectrometer, operating on the pulsed neutron source at ISIS (UK). The experiments have been planned taking advantage of the intrinsic incoherence introduced in the scattering process by the rotational transitions. The measured double-differential cross section gives a direct experimental access to the microscopic dynamics of condensed hydrogen. From the high-energy region of the spectrum, where the impulse approximation for the center of mass motion applies, we have been able to extract the translational mean kinetic energy. In the low-energy region, using the Gaussian approximation, we compare the experimental data in the liquid phase with the results of a model for the velocity autocorrelation ...

2002-07-01

491

Proton scattering by short lived sulfur isotopes  

Energy Technology Data Exchange (ETDEWEB)

Elastic and inelastic proton scattering has been measured in inverse kinematics on the unstable nucleus {sup 40}S. A phenomenological DWBA analysis yields a quadrupole deformation parameter {beta}{sub 2} = 0.35 {+-} 0.05 for the 2{sup +}{sub 1} state. Consistent phenomenological and microscopic proton scattering analyses have been applied to all even-even Sulfur isotopes from A = 32 to A = 40. The microscopic analysis used microscopic collective model densities and a modified Jeukenne-Lejeune-Mahaux effective interaction. This analysis suggests the presence of a neutron skin in the heavy sulfur isotopes. The analysis is consistent with normalization values for {lambda}{sub {upsilon}} and {lambda}{sub {omega}} of 0.95 for both the real and imaginary parts of the JLM potential. (author)

1999-07-01

492

Phenomenological and microscopical description of scattering on different dislocation arrangements  

Energy Technology Data Exchange (ETDEWEB)

Two approaches are used to analyse X-ray or neutron scattering by crystals with different dislocation ensembles. Analogy between the above concepts is discussed. The microscopical approach takes into account the detailed displacement field due to different types of dislocation arrangement in the crystal. Frequently a phenomenological concept operating with the ideas of displacements, strains and stresses arising in the materials under deformation is applied. Unfortunately, the phenomenological concept cannot take into account that similar stress distributions may have significantly different microscopic reasons. The comparison of the results obtained by both phenomenological and microscopic descriptions of scattering enables us to understand the connection between different types of strains and stresses in the crystal with the type of the defects in it. (orig.)

2001-01-01

493

Partial wave expansion of ion-atom elastic scattering in solids  

International Nuclear Information System (INIS)

Elastic scattering cross sections of keV protons in solids (Z=3-82) are calculated using the partial wave expansion technique and the ''muffin-tin'' bound-atom potential. The differential cross sections for small scattering angles of less than 10deg are smaller than those with the Ziegler-Biersack-Littmark potential at all energies and for all solids, although, for larger angles, the two cross sections agree with each other. The mean free paths of the protons in the solids, obtained from the total cross sections, decrease very slowly with decreasing energy. Furthermore, at low energies they approach half the nearest-neighbor distance, which is taken as the radius of the augmented plane wave sphere in the muffin-tin model of crystalline solids. (orig.).

494

On the temperature sensing capability of a fibre optic SPR mechanism based on bimetallic alloy nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

In this work, we have investigated the capability of different bimetallic nanoparticle alloy combinations to be used in fibre optic temperature sensing based on the technique of surface plasmon resonance (SPR). The metals considered for the present analysis are silver, gold and aluminium. The analysis is derived mainly from the thermo-optic effect along with some fundamental concepts of metal optics such as surface scattering, phonon-electron scattering and electron-electron scattering. The performance of the sensor with three different bimetallic nanoparticle alloy combinations is evaluated and compared, numerically, in terms of its sensitivity and accuracy. On the basis of the comparison and some logistic criterion, we predict the best possible bimetallic alloy combination along with a requisite alloy composition ratio that simultaneously provides higher values of both sensitivity and accuracy which is not possible with ...

2009-02-21

495

Measurements of vibrational excitation of N_2, CO, and NO by low energy proton impact  

International Nuclear Information System (INIS)

Differential scattering experiments are reported for proton impact on N_2, CO, and NO in the energy range E/sub lab/=30--80 eV. The measurements include the range of very small scattering angles around 0"0 as well as the rainbow region. The vibrationally resolved energy-loss spectra show a relatively low vibrational inelasticity for all three systems. Differential cross sections, transition probabilities, and the mean vibrational energy transfer are presented. Rotational excitation is indicated by the broadening of the energy-loss peaks which is most significant for H"+--NO. The small-angle scattering data for vibrational excitation in CO show good agreement with the impact parameter theory using the known long-range interactions for this system.

1979-07-01

496

Magnetic Order and Crystal Field Excitations in Er2Ru2O7: A Neutron Scattering Study  

Energy Technology Data Exchange (ETDEWEB)

The magnetic pyrochlore Er{sub 2}Ru{sub 2}O{sub 7} has been studied with neutron scattering and susceptibility measurements down to a base temperature of 270 mK. For the low temperature phase in which the Er sublattice orders, new magnetic Bragg peaks are reported which can be indexed with integer (hkl) for a face centered cubic cell. Inelastic measurements reveal a wealth of crystal field levels of the Er ion and a copious amount of magnetic scattering below 15 meV. The three lowest groups of crystal field levels are at 6.7, 9.1 and 18.5 meV.

2009-10-01

497

Investigation of the structure of nano-porous carbon obtained from polycrystal carbides by means of small-angle X-ray diffraction  

International Nuclear Information System (INIS)

The structure of nano-porous carbon, obtained by means of chlorination of carbide compounds with various crystal structure (SiC, TiC, Mo_2C) is studied through the method of small-angle diffraction. The angular dependences of the scattering intensity obtained are interpreted as the result of scattering from the nanoparticles of different size. The functions of the scattering particles distribution by the m(R_g) inertia radii are determined. It is shown that in spite of the source carbide, the highest fraction of the volume in the porous carbon constitute the particles with R_g #approx# 5 A. The nanoparticles in the samples obtained from SiC, wherein the average value of the R_g"a"v < 6 A, are most uniform by size. The nanoparticles in the porous carbon, obtained from Mo_2C, are on the average by two times larger

1999-08-01

498

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

499

Effect of lithium intercalation on the structure of non-graphitizable carbon: small-angle neutron scattering  

Energy Technology Data Exchange (ETDEWEB)

Recent developments in rechargeable Li-ion battery technology include the use of lithium-carbon compounds instead of metallic anodes. Non-graphitizable carbons offer high capacity as the anode material but it's large irreversible capacity must be solved. The ultimate goals of the present work are to understand the origin of the high capacity and large irreversible capacity in conjunction with the structural change due to Li intercalation and thus to establish a scientific basis for optimizing their performance in real batteries. 'House of cards' model is considered and emphasis is given to find out the size of the pores present in the carbon fibers prepared from an isotropic petroleum pitch and heat treated at 1200degC. Small angle neutron scattering and wide angle neutron scattering results provide enlargement of pores and d-spacing of grapheme layers after Li intercalation. (author)

2001-03-01

500

Assessment of the supramolecular structures presents into biological samples by SAXS technique;Avaliacao das estrutras supramoleculares presentes em amostras biologicas atraves da tecnica de SAXS  

Energy Technology Data Exchange (ETDEWEB)

In this work was made an assessment of the supramolecular structures presents into human breast tissue normal and pathological samples, as well as into two types of animals samples (tendon chicken and pork fat) using the small angle x-ray scattering (SAXS) technique. The scattering profiles of the samples were determined at the momentum transfer range O.150nm{sup -1}<=5:q(=4pi.sin({theta}/2)/{lambda})<=8.500nm{sup -1}. In this range, it was possible identify structures corresponding to collagen fibrils (glandular tissue) and to triacylglycerides (adipose tissue) from the correlation between the information extracted from the human breast tissues scattering profiles and those extracted from animals samples. (author)

2009-07-01