WorldWideScience
1

High speed optical coherence microscopy with autofocus adjustment and a miniaturized endoscopic imaging probe  

UK PubMed Central (United Kingdom)

Optical coherence microscopy (OCM) is a promising technique or high resolution cellular imaging in human tissues. An OCM system for high-speed en face cellular resolution imaging...Full Text Available

2010-03-01

2

Grain size effects on the tensile properties and deformation mechanisms of a magnesium alloy, AZ31B, sheet  

International Nuclear Information System (INIS)

The grain size dependence of the tensile properties and the deformation mechanisms responsible for those properties are examined for Mg alloy, AZ31B, sheet. Specifically, the Hall-Petch effect and strain anisotropy (r-value) are characterized experimentally, and interpreted using polycrystal plasticity modeling. {1 0 . 2} extension twins, {1 0 . 1} contraction twins, and so-called 'double-twins' are observed via microscopy and diffraction-based techniques, and the amount of twinning is found to increase with increasing grain size. For the sheet texture and tensile loading condition examined, {1 0 . 2} extension twinning is not expected, yet the polycrystal plasticity model predicts the observed behavior, including this 'anomalous' tensile twinning. The analysis shows that the Hall-Petch strength dependence, of the polycrystal as a whole, is primarily determined by the grain size dependence of the strength of the prismatic ...

2008-07-15

3

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

UK PubMed Central (United Kingdom)

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

2010-02-03

4

Atom-probe field-ion microscopy investigation of CMSX-4 Ni-base superalloy laser beam welds  

Energy Technology Data Exchange (ETDEWEB)

CMSX-4 superalloy laser beam welds were investigated by transmission electron microscopy and atom probe field-ion microscopy (APFIM). The weld microstructure consisted of fine (10- to 50-nm) irregularly shaped {gamma}` precipitates (0.65 to 0.75 volume fraction) within the {gamma} matrix. APFIM compositions of the {gamma} and {gamma}` phases were found to be different from those in the base metal. Concentration profiles across the {gamma} and {gamma}` phases showed extensive variations of Cr, Co and Al concentrations as a function of distance within the {gamma} phase. Calculated lattice misfits near the {gamma}/{gamma}` interface in the welds are positive values compared to the negative values for base metal. (orig.).

1996-09-01

5

Wavelength-Dependent Differential Interference Contrast Microscopy: Selectively Imaging Nanoparticle Probes in Live Cells  

Energy Technology Data Exchange (ETDEWEB)

Gold and silver nanoparticles display extraordinarily large apparent refractive indices near their plasmon resonance (PR) wavelengths. These nanoparticles show good contrast in a narrow spectral band but are poorly resolved at other wavelengths in differential interference contrast (DIC) microscopy. The wavelength dependence of DIC contrast of gold/silver nanoparticles is interpreted in terms of Mie's theory and DIC working principles. We further exploit this wavelength dependence by modifying a DIC microscope to enable simultaneous imaging at two wavelengths. We demonstrate that gold/silver nanoparticles immobilized on the same glass slides through hybridization can be differentiated and imaged separately. High-contrast, video-rate images of living cells can be recorded both with and without illuminating the gold nanoparticle probes, providing definitive probe identification. Dual-wavelength DIC ...

2009-11-15

6

Evaluation of heterogeneity in thickness of passive films on pure iron by scanning electrochemical microscopy  

Energy Technology Data Exchange (ETDEWEB)

Scanning electrochemical microscopy (SECM) was applied to evaluate the heterogeneity of a passive film formed on a pure iron electrode in deaerated pH 8.4 borate solution. A probe current image of SECM was measured with a tip-generation/sub-strate-collection (TO/SC) mode in deaerated pH 8.4 borate solution containing 0.03 moldm{sup -3} Fe(CN){sub 6}{sup 4-} as a mediator. The difference in thickness of passive films formed on two iron plates at different potentials could be evaluated from the probe current image. The probe current image of the passivated iron surface with distinctive crystal grains was composed of the patch patterns, the shapes of which coincided completely with the shapes of the substrate crystal grains. The probe current flowed above the grain surface oriented to {l_brace}100{r_brace} plane was less than that above the grain surface oriented to ...

1999-04-01

7

Investigation of the magnetic field response from eddy current inspection of defects  

British Library Electronic Table of Contents (United Kingdom)

Eddy current testing is one of the most widely used methods in non-destructive testing for the inspection of conductive materials. Numerical modelling of eddy current testing has emerged as an important approach alongside experimental studies. This paper investigates an application of numerical modelling and experimental study as a means of the quantitative non-destructive evaluation (QNDE) of defects in conductive samples. There are two methods of measuring eddy current response, more commonly by measuring the change in impedance of the eddy current probe coil, or as used in this work, by measuring the change in magnetic field directly using magnetic field sensors such as superconducting quantum interference devices, giant magneto resistance, or as in this case Hall sensors. Specifically,...

2011-01-01

8

Construction and alignment experience of Indus-1 SRS in C.A.T  

International Nuclear Information System (INIS)

A 450 MeV Synchrotron Radiation Source, Indus-1 is being constructed at Centre for Advanced Technology at Indore in central India. This paper narrates our experience in construction and alignment of synchrotron machines which was first of its kind for most of us. Careful design, planning and execution of the work yielded modest results so that alignment accuracies between 0.1 to 0.3 mm could be achieved (in booster synchrotron) and, which have proved to be adequate up till now. The building of the SRS complex was constructed such that machine rings have their foundations isolated from rest of the building. A number of 100 x 150 mm size steel plates were embedded in the concrete of floor and walls to serve as base for reference surveying marks which were established later. The pre-injector and booster ring are enclosed in a radiation shielding zone with separate ventilation system. Dipoles, quadrupoles and a few sextupoles were fiducialised during their field mappings; on a CNC ...

1996-01-01

9

Nanostructured p-CuIn3Se5/n-CdS heterojunction engineered using simple wet chemical approach at room temperature for photovoltaic application  

British Library Electronic Table of Contents (United Kingdom)

Herein, we report engineering of nanostructured p-CuIn3Se5/n-CdS heterojunction thin film on a glass substrate, which is prepared at room temperature using simple wet chemical approach involving ion exchange reactions between CdS and Cu^+, In^3^+ and Se^2^- ions in alkaline medium. The uniform deposition of heterojunction thin films is achieved by optimizing the pH, temperature and molarity of the reactant bath. The as-deposited thin-films were annealed at 200^oC in air for 1h and further characterized for structural, optical and electrical properties using UV-Vis spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Hall effect for type of conductivity, and I-V measurement to investigate the char...

2011-01-01

10

Metallurgical Investigation of a Prematurely Failed Concentric Reducer Tube Used in a Hot-Rolling Mill  

British Library Electronic Table of Contents (United Kingdom)

A concentric reducer tube, which was a part of the top exit roughing hydraulic descaler in a hot strip mill failed prematurely under working pressure. A detailed metallurgical investigation comprising physical examination, optical microscopy, scanning electron microscopy, and electron probe microanalysis was carried out to find out the genesis of the failure. Physical examination revealed cracks located symmetrically around the circumference of the tube that ran along its full length, up to the weld beads at both ends. Optical microscopy of etched samples revealed a banded ferrite-pearlite structure and the existence of forging folds near the change-in-section(160? fillets). Cracks were found to initiate from these forging folds. No structural abnormalities were found in the weld beads and...

2007-01-01

11

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

International Nuclear Information System (INIS)

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

2010-05-01

12

Morphology evolution of Ir-Nb-X (X = Hf, Ta, or Ti) ternary alloys  

Energy Technology Data Exchange (ETDEWEB)

The microstructure evolution of nine samples from three Ir-base ternary systems, Ir-Nb-Hf, Ir-Nb-Ta, and Ir-Nb-Ti, was investigated by microstructure observation using scanning electron microscopy (SEM), composition map-analysis using electron probe microscopy analysis (EPMA), and phase determination using X-ray diffraction (XRD) patterns. The fcc/L1{sub 2} two-phase structure was detected in all the samples. Lattice misfits between fcc and L1{sub 2} phases were calculated. Ir-Nb-Ta and Ir-Nb-Ti alloys exhibited a microstructure quite similar to that of Ni-base superalloys, and the cuboidal L1{sub 2} precipitates in Ir-Nb-Ta and Ir-Nb-Ti alloys could maintain up to 1900 {sup o}C.

2007-01-31

13

Local thermal property analysis by scanning thermal microscopy of an ultrafine-grained copper surface layer produced by surface mechanical attrition treatment  

International Nuclear Information System (INIS)

Scanning thermal microscopy (SThM) was used to map thermal conductivity images in an ultrafine-grained copper surface layer produced by surface mechanical attrition treatment (SMAT). It is found that the deformed surface layer shows different thermal conductivities that strongly depend on the grain size of the microstructure: the thermal conductivity of the nanostructured surface layer decreases obviously when compared with that of the coarse-grained matrix of the sample. The role of the grain boundaries in thermal conduction is analyzed in correlation with the heat conduction mechanism in pure metal. A theoretical approach, based on this investigation, was used to calculate the heat flow from the probe tip to the sample and then estimate the thermal conductivities at different scanning positions. Experimental results and theoretical calculation demonstrate that SThM can be used as a tool for the thermal property and microstructural analysis of ...

2006-06-15

14

On the possible relation between the absence of superconductivity in Au and Pd-Ag alloys and the negative sign of the Hall coefficient  

International Nuclear Information System (INIS)

Available data are presented which support the supposition that metals and alloys with a negative low-temperature Hall coefficient are apparently not superconducting. (author).

1983-01-01

15

Experimental Verification of the Hall Effect during Magnetic Reconnection in a Laboratory Plasma  

Energy Technology Data Exchange (ETDEWEB)

In this letter we report a clear and unambiguous observation of the out-of-plane quadrupole magnetic field suggested by numerical simulations in the reconnecting current sheet in the Magnetic Reconnection Experiment (MRX). Measurements show that the Hall effect is large in collisionless regime and becomes small as the collisionality increases, indicating that the Hall effect plays an important role in collisionless reconnection.

2005-06-16

16

PROBE FOR FLOW PASSAGE INSPECTION  

J-STORE (Japan)

Full Text Available

2007-05-11

18

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

International Nuclear Information System (INIS)

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

2005-06-01

19

Hall mobility minimum of temperature dependence in polycrystalline silicon  

Science.gov (United States)

Molten zone recrystallized as well as sheet grown polycrystalline silicon has shown a minimum in the temperature dependence of the Hall mobility. In order to explain this experimental finding a new model is proposed, which is based on negatively charged grain boundaries for the p-type silicon material under study. This results in a potential well at the grain boundaries instead of the more generally observed potential barrier. A key feature in the model is that the space charge density at the grain boundary depends on the Fermi level position and therefore on temperature. In addition, the change in the measured Hall mobility before and after hydrogen passivation of the grain boundaries is discussed.

1998-01-01

20

NASA Project Inducted Into Space Technology Hall of  

Science.gov (United States)

Apr 9, 2003 ... Adam Kissiah Jr., a retired KSC engineer, will be honored for his development of the digital hearing aid technology that led to the cochlear ...

21

ELECTRIC AND GALVANOMAGNETIC PROPERTIES OF ...  

Science.gov (United States)

... Abstract : The electric resistance in weak (diluted) solid solutions of the Pd-Ag and Fe-W systems, as wellAS THE Hall effect in a Pd-Ag system ...

1961-06-27

22

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

International Nuclear Information System (INIS)

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

2010-08-01

23

Pore formation during hybrid laser-tungsten inert gas arc welding of magnesium alloy AZ31B--mechanism and remedy  

International Nuclear Information System (INIS)

One of the major concerns during high speed welding of magnesium alloys is the presence of porosity in the weld metal that can deteriorate mechanical properties. This study seeks to analyze the presence method and quantity of pore during hybrid laser-tungsten inert gas arc (TIG) welding of magnesium alloy AZ31B by radiography, optical microscopy and electron probe microanalysis (EMPA). At the same time, it identifies both the mechanism of pore formation and a remedy for this problem. The experimental results indicate that lacking of shielding gas for laser beam is the dominant cause of macroporosity formation during the hybrid of laser-TIG welding of magnesium Alloys AZ31B plate, and hydrogen is not main cause to form large pores. A favorable weld without porosity can be obtained by appending lateral shielding gas for laser beam.

2005-01-15

24

Morphology, structure, and conductivity of polypyrrole prepared in the presence of mixed surfactants in aqueous solutions  

British Library Electronic Table of Contents (United Kingdom)

Polypyrrole (PPy) was prepared from different mixed-surfactant solutions with ammonium persulfate as an oxidant. Three types of combinations were selected, including cationic/anionic, cationic/nonionic, and anionic/nonionic mixed-surfactant solutions. The surfactants used in the experiments included cetyltrimethylammonium bromide (cationic surfactant), sodium dodecyl sulfate (anionic surfactant), sodium dodecyl sulfonic acid salt (anionic surfactant), poly(vinyl pyrrolidone) (nonionic surfactant), and poly(ethylene glycol) (nonionic surfactant). The morphology, structure, and conductivity of the resulting PPy were investigated in detail with scanning electron microscopy, Fourier transform infrared spectra, and the typical four-probe method, respectively. The results showed that the interac...

2007-01-01

25

Effects of stress on radiation hardening and microstructural evolution in A533B steel  

British Library Electronic Table of Contents (United Kingdom)

Bent specimens of A533B steel (0.16wt% Cu) were irradiated at 290degreeC to 1dpa with 6.4MeV Fe3+ ions. Calculated tensile stresses at the irradiated surface were set to 0, 250, 500 and 750MPa. The specimens were subjected to hardness measurements, transmission electron microscopy (TEM) observations and three-dimensional atom probe (3DAP) analysis. The radiation-induced hardening decreased with increasing stress to 500MPa which was near the yield strength. TEM and 3DAP results showed that well-defined dislocation loops and solute clusters were formed. The diameter of dislocation loops increased and the number density decreased when the stress was applied, whereas the diameter and number density of solute clusters decreased. The hardening was mainly attributed to solute cluster formation. A...

2010-01-01

26

Design and microstructural analysis of magnesium alloys for dynamical applications  

British Library Electronic Table of Contents (United Kingdom)

A microanalytical characterization of cast magnesium alloys of eutectic origin based on the Mg?Al?Ca ternary matrix system has been carried out in order to investigate the influence of alloying elements on their microstructure as well as microchemistry-processing-microstructural relations using structure-sensitive techniques of electron microscopy, mechanical spectroscopy (internal friction), X-ray diffractometry, and advanced microanalytical methods including electron probe compositional analysis. Following the data obtained here there is direct correlation of microstructure with creep properties of the new experimental magnesium alloys. The creep and heat-induced properties of the multicomponent magnesium alloys containing low range of inexpensive additions of titanium (0.07?0.2%) or str...

2011-01-01

27

Structure and Function Evolution of Thiolate Monolayers on Gold  

Energy Technology Data Exchange (ETDEWEB)

The use of n-alkanethiolate self-assembled monolayers on gold has blossomed in the past few years. These systems have functioned as models for common interfaces. Thiolate monolayers are ideal because they are easily modified before or after deposition. The works contained within this dissertation include interfacial characterization (inbred reflection absorption spectroscopy, ellipsometry, contact angle, scanning probe microscopy, and heterogeneous electron-transfer kinetics) and various modeling scenarios. The results of these characterizations present ground-breaking insights into the structure, function, and reproducible preparation of these monolayers. Surprisingly, three interfacial properties (electron-transfer, contact angle, and ellipsometry) were discovered to depend directly on the odd-even character of the monolayer components. Molecular modeling was utilized to investigate adlayer orientation, and suggests that these effects are ...

2006-05-01

28

Physico-chemical, optical and electrochemical properties of iron oxide thin films prepared by spray pyrolysis  

International Nuclear Information System (INIS)

Iron oxide thin films were prepared by spray pyrolysis technique onto glass substrates from iron chloride solution. They were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and (UV-vis) spectroscopy. The films deposited at T _s #<=# 450 deg. C were amorphous; while those produced at T _s_u_b = 500 deg. C were polycrystalline #alpha#-Fe_2O_3 with a preferential orientation along the (1 0 4) direction. By observing scanning electron microscopy (SEM), it was seen that iron oxide films were relatively homogeneous uniform and had a good adherence to the glass substrates. The grain size was found (by RX) between 19 and 25 nm. The composition of these films was examined by X-ray photoelectron spectroscopy and electron probe microanalysis (EPMA). These films exhibited also a transmittance value about 80% in the visible and infrared range. The cyclic ...

2006-12-15

29

Magnetic imaging of ion-irradiation patterned Co/Pt multilayers using complementary electron and photon probes  

Energy Technology Data Exchange (ETDEWEB)

The three-dimensional magnetic structure and reversal mechanism of patterned Co/Pt multilayers, were imaged using complementary Lorentz transmission electron microscopy (LTEM) (in-plane component) and magnetic transmission x-ray microscopy (M-TXM) (perpendicular magnetization). The Co/Pt films with perpendicular anisotropy were patterned by ion irradiation through a stencil mask to produce in-plane magnetization in the irradiated regions. The boundaries of the patterns, defined by the transition from out-of-plane to in-plane magnetization, were found to be determined by the stencil mask, whilst the scale of the magnetic reversal by the physical microstructure. The nucleation fields were substantially reduced to 50 Oe for the in-plane regions and 1 kOe for the perpendicular regions, comparing to 4.5 kOe for the as-grown film. The perpendicular reversals were found to always originate at the pattern boundaries.

2001-04-01

30

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-03-25

31

INFLATABLE EDDY CURRENT INSPECTION PROBE FOR ...  

Science.gov (United States)

... INTERMEDIATE TO THE CENTRALIZERS IS A SENSING SECTION COMPRISED OF MULTIPLE EDDY CURRENT PROBES ON FLEXIBLE ...

1981-12-01

32

Defect engineering via ion implantation to control B diffusion in Si  

International Nuclear Information System (INIS)

The processes which are currently studied in the fabrication of B-doped ultra shallow junctions (USJ) usually involve a preamorphization step to reduce B channelling effect during implantation and to improve B electrical activation. At this stage a high amount of Si interstitial atoms (Is), which dramatically increases the B diffusivity, is introduced. The introduction of voids in Si is a promising tool to control B transient enhanced diffusion (TED), because of their ability to capture Is. In this work the efficiency of a cavity band to reduce B TED is checked in silicon interstitial supersaturation conditions, obtained by high dose Si implantation. He is implanted either at 10 keV or at 50 keV with a fluence of 5 x 10"1"6 cm"-"2. Conventional techniques to introduce and activate the B (conventional ion implantation and rapid thermal annealing (RTA)) are applied in order to have a better control of the technological process to focus on the benefit of the cavity layer. The samples were ...

2009-03-15

33

Ferromagnetism in Mn-doped GaAs layers: Effects of laser annealing  

Energy Technology Data Exchange (ETDEWEB)

The properties of Mn-doped GaAs layers grown by laser deposition were investigated with measurements of Hall effect and magneto-optical Kerr effect (MOKE). The electrical and magnetic parameters of the layers were defined by growth temperature and quantity of sputtered Mn. It was shown that room-temperature ferromagnetism is revealed by MOKE and, after ruby laser 25 ns pulse annealing, by Hall effect measurements.

2006-05-15

34

Energy analysis for Fort McNair, Marshall Hall  

Science.gov (United States)

Marshall Hall was selected by the US Army Corps of Engineers to participate in the Energy Efficiency Analysis Program. The objective of this program is to assist military installations in identifying energy usage and cost saving projects at their facilities and possibly provide funding for projects. Entech Engineering, Inc. was selected to perform this study.

1995-08-01

35

Probe-Flaw Interactions with Eddy Current Array Probes  

Science.gov (United States)

... The development of various modeling methods for conventional eddy current probes (absolute, differential, two-port, etc.) has led to a general ...

36

#omega#-Assisted nucleation and growth of #alpha# precipitates in the Ti-5Al-5Mo-5V-3Cr-0.5Fe #beta# titanium alloy  

International Nuclear Information System (INIS)

This paper discusses the structural and compositional changes at the nanometer scale associated with the nucleation and growth of #alpha# precipitates in the #beta# titanium alloy Ti-5553 (Ti-5Al-5Mo-5 V-3Cr-0.5Fe) with #omega# precipitates acting as heterogeneous nucleation sites. The microstructural evolution in this alloy, during #beta#-solutionizing, quenching and aging type heat-treatments, has been investigated by combining results from scanning electron microscopy, orientation imaging microscopy, transmission electron microscopy, high-resolution TEM and three-dimensional atom probe (3DAP) tomography. Athermal #omega# precipitates form in this alloy on quenching from above the #beta# transus temperature. On isothermal annealing at low temperatures, these #omega# precipitates coarsen to form chemically ordered #omega# precipitates, accompanied by the nucleation of the stable #alpha# phase. ...

2009-04-01

38

Resistivity, Hall effect, and magnetic susceptibility of UPd_2Si_2  

International Nuclear Information System (INIS)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd_2Si_2 have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd_2Si_2 is Curie-Wiess-like along the c axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

39

Resistivity, Hall effect, and magnetic susceptibility of UPd[sub 2]Si[sub 2  

Energy Technology Data Exchange (ETDEWEB)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd[sub 2]Si[sub 2] have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd[sub 2]Si[sub 2] is Curie-Wiess-like along the [ital c] axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

1993-12-15

40

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-08-01

41

BOUNDARY LAYER FLOW AND DOUBLE DIFFUSION OVER AN UNSTEADY STRETCHING SURFACE WITH HALL EFFECT  

British Library Electronic Table of Contents (United Kingdom)

The present investigation is concerned with the effect of Hall currents on boundary layer flow, and heat and mass transfer of an electrically conducting fluid over an unsteady stretching sheet in the presence of a strong magnetic field. The electron-atom collision frequency is assumed to be relatively high, so that the Hall effect is assumed to exist, while the induced magnetic field is neglected. The governing time-dependent boundary layer equations for momentum, thermal energy, and concentration are reduced using a similarity transformation to a set of coupled ordinary differential equations. The similarity ordinary differential equations are then solved numerically by the successive linearization method together with the Chebyshev pseudo-spectral collocation method. Effects of the Prand...

2011-01-01

42

SPECIAL EDDY CURRENT PROBES FOR HEAT ...  

Science.gov (United States)

... Accession Number : ADD326926. Title : SPECIAL EDDY CURRENT PROBES FOR HEAT EXCHANGER INSPECTION. Corporate Author : ...

1986-11-01

43

OPTIMIZATION OF EDDY CURRENT PROBES FOR NDT OF ...  

Science.gov (United States)

... Accession Number : ADD321199. Title : OPTIMIZATION OF EDDY CURRENT PROBES FOR NDT OF CARBON FIBER COMPOSITES. ...

1985-04-01

44

Multiple-Element Eddy Current Probes for Enhanced ...  

Science.gov (United States)

... Accession Number : ADD335251. Title : Multiple-Element Eddy Current Probes for Enhanced Inspection,. Corporate Author : ...

1993-07-01

45

Characterization of Absolute-Resonant Eddy Current Probes,  

Science.gov (United States)

... Accession Number : ADD335809. Title : Characterization of Absolute-Resonant Eddy Current Probes,. Corporate Author : ...

46

Advanced Nondestructive Evaluation (NDE) for Retirement for ...  

Science.gov (United States)

... 21 2.3 Eddy Current Probes ..... 22 2.3.1 Improved Probe Internal ...

2000-08-01

47

Weinstein and Harry W. - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Oxydes d'Uranium et de Plutonium. J. Nucl. Mat., vol. 33, no. 1, Oct. 1969, pp. 40-51. 21. Hall, A. R.: Elastic Moduli and Internal Friction of Some Uranium ...

48

Thermal State-of-Charge in Solar Heat Receivers - NASA Technical ...  

Science.gov (United States)

Thermal Cavity Receivers,". JPL. Publication. 83-97,. 1983. 5Hall, III, C.A., Glakpe, E.K., Cannon,. J.N., and. Kerslake,. T.W., "Modeling ...

49

NAME=\\  

Wastenet

...links ensure all of our managed accommodation is easily accessible to both campus sites and our special student arrangement makes travelling on the Metro rapid transit system easily affordable. Our halls are comfortable and they are very reasonable. Download the rents table here Rents 2009-2010 Students living in ...

50

APOD: January 25, 1997 - M51: The Whirlpool Galaxy  

Science.gov (United States)

on the picture will download the highest resolution version available. M51: The Whirlpool Galaxy Credit: W. Keel (U. Alabama), 1.1-meter Hall Telescope, Lowell Observatory...

2011-10-07

51

APOD: December 18, 1995 - M51: The Whirlpool Galaxy  

Science.gov (United States)

on the picture will download the highest resolution version available. M51: The Whirlpool Galaxy Credit: 1.1 Meter Hall Telescope, Lowell Observatory, Bill Keel (U. Alabama)...

2011-10-07

52

/flJ /k/-C&  

Science.gov (United States)

nt method for the Stefan problem, Int. J. Num. Meth. in . . (25) G. STKANG AND G.J. FIX, A n v s i s of the F U L L. Element, Prentice-Hall, 1973. ...

53

Understanding and controlling transient enhanced dopant diffusion in silicon  

Energy Technology Data Exchange (ETDEWEB)

Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during initial annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, the authors have used B doping marker layers in Si to probe the injection of interstitials from near-surface, non-amorphizing Si implants during annealing. The in-diffusion of interstitials is limited by trapping at impurities and has an activation energy of {approximately}3.5 eV. Substitutional C is the dominant trapping center with a binding energy of 2--2.5 eV. The high interstitial supersaturation adjacent to the implant damage drives substitutional B into metastable clusters at concentrations below the B solid solubility limit. Transmission electron microscopy shows that the interstitials driving TED are emitted from {l_brace}311{r_brace} defect clusters in the damage region at a rate which also exhibits an activation energy of 3.6 ...

1995-12-31

54

Understanding and controlling transient enhanced dopant diffusion in silicon  

International Nuclear Information System (INIS)

Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during initial annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, the authors have used B doping marker layers in Si to probe the injection of interstitials from near-surface, non-amorphizing Si implants during annealing. The in-diffusion of interstitials is limited by trapping at impurities and has an activation energy of #approx#3.5 eV. Substitutional C is the dominant trapping center with a binding energy of 2--2.5 eV. The high interstitial supersaturation adjacent to the implant damage drives substitutional B into metastable clusters at concentrations below the B solid solubility limit. Transmission electron microscopy shows that the interstitials driving TED are emitted from #left brace#311#right brace# defect clusters in the damage region at a rate which also exhibits an activation energy of 3.6 ...

55

Surface modification of titanium by radio frequency plasma nitriding  

Energy Technology Data Exchange (ETDEWEB)

Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti{sub 2}N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 {mu}m{sup 2}/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near ...

2006-02-21

56

Surface modification of titanium by radio frequency plasma nitriding  

International Nuclear Information System (INIS)

Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti_2N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 #mu#m"2/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near to the ...

2006-02-21

57

Surface hardening utilizing high-density plasma nitriding on stainless steel alloys  

Energy Technology Data Exchange (ETDEWEB)

By using a plasma nitriding procedure at the PUPR Mirror Cusp Plasma machine, surface hardness is increased in 302/304-type stainless steel samples by exposing them to high-ion-density plasma at high vacuum. This method successfully dopes the surface of the material with strengthening nitrogen ions, without the use of chemical procedures that sacrifice the resistance to corrosion of the given material. A 500 V negative bias is placed on the sample exposed to the nitrogen plasma, where high-energy ions are therefore attracted and immersed into the metallic matrix microns into the surface of the stainless steel. This potential maintains a constant surface temperature at approximately 800 deg. C. The plasma parameters including ion density and plasma temperature were diagnosed using single Langmuir probes. The stainless steel samples were then tested using scanning electron microscopy (SEM), and Vickers micro-hardness testing to determine the ...

2008-10-15

58

Surface hardening utilizing high-density plasma nitriding on stainless steel alloys  

International Nuclear Information System (INIS)

By using a plasma nitriding procedure at the PUPR Mirror Cusp Plasma machine, surface hardness is increased in 302/304-type stainless steel samples by exposing them to high-ion-density plasma at high vacuum. This method successfully dopes the surface of the material with strengthening nitrogen ions, without the use of chemical procedures that sacrifice the resistance to corrosion of the given material. A 500 V negative bias is placed on the sample exposed to the nitrogen plasma, where high-energy ions are therefore attracted and immersed into the metallic matrix microns into the surface of the stainless steel. This potential maintains a constant surface temperature at approximately 800 deg. C. The plasma parameters including ion density and plasma temperature were diagnosed using single Langmuir probes. The stainless steel samples were then tested using scanning electron microscopy (SEM), and Vickers micro-hardness testing to determine the ...

2008-10-01

59

Some computer simulations of semiconductor thin film growth and strain relaxation in a unified atomistic and kinetic model  

Energy Technology Data Exchange (ETDEWEB)

An overview is provided of an evolving atomistic and kinetic model of semiconductor growth that unifies the main features of strain relaxation in low and high lattice misfit heteroepitaxy. The model reveals a kinetic pathway for dislocation formation during growth with little or no energy cost at low misfits, thus providing a way out of the longstanding dilemma of too high dislocation nucleation energies predicted by classical theories of the equilibrium behavior of a fixed number of particles at low misfits. The essential kinetic process underlying the model are identified on the basis of comparison of the predictions of kinetic Monte-Carlo simulations of growth with real-time or in-situ data obtained in such experiments as reflection high-energy electron diffraction (RHEED) and scanning probe microscopy (SPM). Relative significance of these atomistic kinetic processes is shown to naturally lead to strain relaxation via defect initiation at ...

1996-12-31

60

Sol-gel coatings with phosphonate functionalities for surface modification of magnesium alloys  

International Nuclear Information System (INIS)

Hybrid organic-inorganic coatings with phosphonate functionalities have been synthesized and evaluated as prospective surface treatments for magnesium materials. These coatings have been processed via a sol-gel route by hydrolysis and condensation of a mixture of diethylphosphonatoethyltriethoxy-silane and tetraethoxy-silane with variable molar ratios. The coatings morphology and the surface chemistry at the coating/substrate interface have been characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, "3"1P nuclear magnetic resonance spectroscopy, and time-of-flight secondary ion mass spectrometry. The corrosion protection performance of the coatings deposited on magnesium alloy AZ31B has been examined by a group of electrochemical techniques including potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, a scanning Kelvin probe technique has been used to investigate interfacial ...

2006-08-30

61

Review of progress in quantitative NDE. Abstracts  

Energy Technology Data Exchange (ETDEWEB)

The meeting was arranged into the following sessions: introductory; advanced ceramics and ceramic composites; ceramic and metal matrix composites; electronic materials and devices; acoustoelasticity, stress, and texture; composites-porosity, strength, and UT propagation; process modeling and monitoring; thermal wave physics; material properties, composites, surfaces, and interfaces; acoustic emission; ferromagnetic materials; new sensors; NDE reliability assessment; elastic wave scattering and propagation; image analysis, data storage, and signal processing; UT transducers; weldments and bonded materials; eddy current models; unified life cycle engineering; x rays, CT, and NMR; eddy current probes and instruments; acoustic microscopy imaging, and reconstruction; signal processing, measurement techniques, and systems; NDE applications of artificial intelligence; crack behavior influenced by history; inversion procedures for UT and EC; process ...

1986-01-01

62

Micromachining using a focused ion beam miller  

International Nuclear Information System (INIS)

Full text: The focused ion beam (FIB) miller is becoming well established as a machine for the structural analysis of materials and for the rapid preparation of transmission electron microscope specimens. It has also been used for some time in the semiconducting materials industry for the analysis, repair and redesign of device materials. However, one emerging technique is the use of the FIB for micromachining. The FIB software can also be used to manufacture and machine components. This process can occur through converting software, typically in the form of bitmaps or TIF files, to proprietary 'stream' files. These files allow, often complex, patterns to be generated and milled into the specimen and thus the generation of micro-electromechanical systems. Frequently, this involves largely two-dimensional patterns and structures, however, more complex patterns and file types can be generated which allow, for example, device prototyping or the preparation of three-dimensional structures ...

2002-02-01

63

How epitaxial are Pd/sub 2/Si-Si interfaces  

Energy Technology Data Exchange (ETDEWEB)

Pd/sub 2/Si layers produced by evaporation or sputtering onto silicon substrates were examined by high resolution electron microscopy, microdiffraction, X-ray, energy loss and Auger spectroscopy. The Si-Pd/sub 2/Si interfaces produced by evaporation were in all cases rougher and more polycrystalline than those produced by sputtering. X-ray microanalysis showed the predictable variation in palladium distribution across the interface but quantification did not produce the expected palladium-to-silicon ratios, primarily because of probe broadening and X-ray-induced fluorescence. Energy loss spectra showed plasmon energy shifts and changes in Si L edge shape due to bond formation with palladium. Auger data provided evidence for a small amount of oxygen at the Si-Pd/sub 2/Si interface. Electrical measurements of the ideality factor for Schottky barriers made from the materials produced higher values for the rougher evaporation-formed interfaces ...

1983-06-17

64

Effect of substrate temperature on structural properties and corrosion resistance of carbon thin films used as bipolar plates in polymer electrolyte membrane fuel cells  

International Nuclear Information System (INIS)

In this work, the effects of substrate temperature that was changed from 100 to 500 "oC on the structural, chemical and electrical properties of carbon films, prepared by direct current magnetron sputtering technique, on 316L stainless steel as bipolar plate had been investigated. Raman spectroscopy and scanning electron microscopy (SEM) were performed to study the structure and the morphology of the deposited films, respectively. The corrosion resistance and the electrical resistivity were carried out by using corrosion tests and four point-probe technique. The results show that the carbon films change the structure from amorphous to graphite-like by increasing temperatures. At the temperatures higher than 300 "oC, the holes and porosities are formed on the film indicating a decrease of film quality. According to our results, corrosion resistance and electrical properties are depended strongly on the substrate temperature.

2010-07-23

65

Deposition of Cu film on SiO_2 using a partially ionized beam  

International Nuclear Information System (INIS)

Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO_2 substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio I(111)/I(200) reaches its maximum value indicating a strong left-angle 111 right-angle texture, while the impurity concentration and resisitivity are minimum. The correlation between the structural, compositional and electrical properties ...

1990-01-01

66

Deposition of Cu film on SiO sub 2 using a partially ionized beam  

Energy Technology Data Exchange (ETDEWEB)

Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. The correlation between the structural, compositional and ...

1990-05-01

67

Deposition of Cu film on SiO sub 2 using a partially ionized beam  

Science.gov (United States)

Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. The correlation between the structural, compositional and ...

1990-05-01

68

Characterization of spent fuel approved testing material--ATM-104  

Energy Technology Data Exchange (ETDEWEB)

The characterization data obtained to date are described for Approved Testing Material 104 (ATM-104), which is spent fuel from Assembly DO47 of the Calvert Cliffs Nuclear Power Plant (Unit 1), a pressurized-water reactor. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory (PNL) on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well-characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) Program. ATM-104 consists of 128 full-length irradiated fuel rods with rod-average burnups of about 42 MWd/kgM and expected fission gas release of about 1%. A variety of analyses were performed to investigate cladding characteristics, radionuclide inventory, and redistribution of fission products. Characterization data include (1) fabricated fuel design, irradiation history, and subsequent storage and handling history; (2) isotopic ...

1991-12-01

69

Alloys and oxides on carbon-supported Pt-Sn electrocatalysts for ethanol oxidation  

Energy Technology Data Exchange (ETDEWEB)

This work reports studies of ethanol oxidation on Pt-Sn/C catalysts with nearly the same particle size and identical overall composition having different amounts of oxide and alloyed phases. Results of characterization of physical properties by transmission electron microscopy (TEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), X-ray photoelectron spectroscopy (XPS), and in situ dispersive X-ray absorption spectroscopy (DXAS) are presented. The variation in the amount of oxide and alloyed phases, promoted by heat treatments in mild temperature conditions, does not produce any significant particle growth. Cyclic voltammetry and oxidation of adsorbed CO in acid medium are used to probe the surface conditions. Data on the electrocatalytic activity towards ethanol oxidation, obtained by potential sweeps and chronoamperometry, are discussed and correlate well with the physical properties. This study, carried out in the absence ...

2010-06-01

70

Daya Bay Neutrino Experiment: Goal, Progress and Schedule  

CERN Document Server

Daya Bay Neutrino Experiment is dedicated to measuring the last unobserved neutrino mixing angle theta_13. The predicted precision on sin^2(2theta_13) is 0.01 at 90% confidence level. This document briefly reviews the measurement method and detector construction status. The first two anti-neutrino detectors' dry run result is also discussed. The Daya Bay near hall data taking is expected to commence in the summer of 2011 and the data taking of all of the three halls in the summer of 2012.

2011-01-01

71

High Resolution Eddy Current Probes for Non Destructive Testing  

Science.gov (United States)

New industrial Non Destructive Testing requires the development of new probes: technologies such as high spatial resolution probes for small breaking flaws detection or flexible probes for complex curved surfaces inspection. The CEA/LIST has designed and integrated 2 probes to answer industrial's constraints. The first one is based on Giant Magneto-Resistance and is able to detect 50 ?m3 flaws. The second one is based on micro-coils etched on kapton and its flexibility is adapted to curved surfaces inspection. Both are multi-elements probes, allowing fast inspection. This paper presents those new probes, their design and their performances.

2008-02-01

72

Surfactant based sol-gel approach to nanostructured LiFePO{sub 4} for high rate Li-ion batteries  

Energy Technology Data Exchange (ETDEWEB)

Porous nanostructured LiFePO{sub 4} powder with a narrow particle size distribution (100-300nm) for high rate lithium-ion battery cathode application was obtained using an ethanol based sol-gel route employing lauric acid as a surfactant. The synthesized LiFePO{sub 4} powders comprised of agglomerates of crystallites <65nm in diameter exhibiting a specific surface area ranging from 8m{sup 2}g{sup -1} to 36m{sup 2}g{sup -1} depending on the absence or presence of the surfactant. The LiFePO{sub 4} obtained using lauric acid resulted in a specific capacity of 123mAhg{sup -1} and 157mAhg{sup -1} at discharge rates of 10C and 1C with less than 0.08% fade per cycle, respectively. Structural and microstructural characterization were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray (EDX) analysis while electronic conductivity and ...

2007-01-01

73

Array coil probe: Final report  

Energy Technology Data Exchange (ETDEWEB)

Nuclear steam generator tubes have become flawed in ways that challenge conventional eddy current probes. In response to the shortcomings of conventional probes, array probes have been developed to improve measurement capabilities. However, the commercially available array probes have exhibited several weaknesses that offset the advantages and limit the applications in steam generator inspections. A primary weakness is the relatively high rate of probe failure coupled with the high unit cost for each probe. This can be costly for a utility in the time lost for probe replacement and increased radiation exposure in addition to the probe costs. Other weaknesses which make array probes undesirable for routine use are: poor mechanical and electrical characteristics; difficulty in operation and ...

1987-03-01

74

The development of multiple probe microdialysis sampling in the stomach  

UK PubMed Central (United Kingdom)

A multiple probe approach of implanting microdialysis probes into each separate tissue layer would better represent sampling from the stomach. Presently, microdialysis sampling experiments are...Full Text Available

2008-09-10

75

Characterizing Differential Air-Core Eddy Current Probes  

Science.gov (United States)

... Accession Number : ADD331250. Title : Characterizing Differential Air-Core Eddy Current Probes. Corporate Author : Personal ...

76

Breakdown of the lattice polaron picture in La{sub 0.7}Ca{sub 0.3}MnO{sub 3} single crystals  

Energy Technology Data Exchange (ETDEWEB)

When heated through the magnetic transition at T{sub C}, La{sub 0.7}Ca{sub 0.3}MnO{sub 3} changes from a band metal to a polaronic insulator. The Hall constant R{sub H}, through its activated behavior and sign anomaly, provides key evidence for polaronic behavior. We use R{sub H} and the Hall mobility to demonstrate the breakdown of the polaron phase. Above 1.4T{sub C}, the polaron picture holds in detail, while below, the activation energies of both R{sub H} and the mobility deviate strongly from their polaronic values. These changes reflect the presence of metallic, ferromagnetic fluctuations, in the volume of which the Hall effect develops additional contributions tied to quantal phases. (c) 2000 The American Physical Society.

2000-04-01

77

Study of silicon damage caused by ultra-low energy boron implantation  

International Nuclear Information System (INIS)

Ultra-shallow junction formation in deep submicron Si devices is limited by anomalous diffusion of the dopant, which is related to the release of interstitials from defect clusters formed during the implantation of energetic ions or the subsequent annealing. The work described in this dissertation is concerned with the effects of low energy B ion implantation, especially damage formation, clustering and its annealing. After a review of the stopping and ranges of energetic ions in Si, the formation of implant damage, in particular of point defects, their migration, agglomeration and annihilation, including the involvement of dopant ions, is considered. A description of the Salford ultra low energy implanter is given and the main analysis technique, medium ion energy scattering (MEIS) reviewed. Additional analytical techniques used, such as secondary ion mass spectrometry (SIMS), 4-point probe and cross section transmission microscopy (XTEM) as ...

78

Spin polarisation and anomalous Hall effect in NiMnSb films  

International Nuclear Information System (INIS)

NiMnSb has attracted a great deal of interest as a spin injector/detector in spintronic devices because it has a Curie temperature of 728 K and is predicted to be half-metallic (100% spin polarized). NiMnSb has been reported to have greatly reduced surface polarization, and to lose its half metallicity above 80 K. Here we report the investigation of the surface polarisation and electronic structure of NiMnSb by measurement of the transport spin polarization using point contact Andreev reflection spectroscopy, and anomalous Hall effect in thin films on Si(0 0 1). A comparison to bulk properties is made.

2004-05-01

79

Police in the Dorms: Student Safety or Privacy Infringement?  

Science.gov (United States)

Since 1970, officers on the Seattle campus have regularly patrolled the hallways of dormitories of the University of Washington. It is a community-policing strategy, a low-key way to engage students. However, the practice might cease this fall. In June, the state's Court of Appeals ruled that students have the same right to privacy in dormitory hallways as they do in their rooms. Therefore, the court concluded, campus police officers lack the legal authority to randomly patrol residence halls. Although the closely watched ruling bears on only one state, it reveals the tension between privacy and security in dormitories everywhere. Residence halls are legally complex spaces, where crime often creeps in and where residents, perhaps more than ever, expect administrators and police officers to ensure their safety.

2008-07-25

80

Magnetic and electronic properties of Mn{sub 4}Si{sub 7}  

Energy Technology Data Exchange (ETDEWEB)

We present a systematic study of the magnetization, Hall effect and specific heat on single crystals of Mn{sub 4}Si{sub 7}. Curie-Weiss law is observed above 43 K. At low-temperature moments order in an anisotropic helical state and are aligned above 1 T. We observe an anomalous Hall effect in both {rho}{sub H} vs. B and in R{sub H} vs. T curves and a field dependence of the low T specific heat due to spin fluctuations. The magnetic moments (p{sub eff} and p{sub sat}) are the lowest reported for similar itinerant magnetic systems, this suggests that Mn{sub 4}Si{sub 7} is a good candidate to observe critical quantum fluctuations expected for a marginal Fermi liquid.

2004-05-01

81

Transmit-receive eddy current probes for heat exchanger inspection  

International Nuclear Information System (INIS)

This paper describes various eddy current probes, and their performance, which were developed at the Chalk River Laboratories of Atomic Energy of Canada. Included are probes for detecting defects at tubesheet regions in heat exchanger tubes, defects at expansion-transition regions in finned tubes, and defects in ferromagnetic tubes. All of these probes can be used with conventional commercially available instruments. (author).

1987-09-01

83

Probing Neutron Star Evolution with Gamma Rays  

Science.gov (United States)

The research sponsored by this grant was conducted in two fields of high-energy astrophysics:

1996-01-01

84

Optic probe for semiconductor characterization  

Energy Technology Data Exchange (ETDEWEB)

Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

2008-09-02

87

Field trial of a fast single-pass transmit-receive probe during Gentilly II steam generator tube inspection  

International Nuclear Information System (INIS)

A new generation of transmit-receive single-pass probes, denoted as C6 or X probe, was field tested during the Gentilly II, 2000 steam generator tube inspection. This probe has a performance equivalent to rotating probes and can be used for tubesheet and full-length inspection at an inspection speed equivalent to that of bobbin probes. Existing C3 transmit-receive probes have been demonstrated to be effective in detecting circumferential cracks. The C5 probe can detect both circumferential and axial cracks and volumetric defects but cannot discriminate between them. The C6 probe expands on the capabilities of both probes in a single probe head. It can simultaneously detect and discriminate between circumferential and axial cracks to satisfy different plugging criteria. It has ...

2000-11-19

89

Device for the inspection of curved pipes in steam raising units  

Energy Technology Data Exchange (ETDEWEB)

The chain of eddy current probes and a film cassette probe, which responds to radiation from a radio-active source in one of the heat exchanger pipes is examined. The probes are moved by nylon pipes on both ends of the chain through the pipe to be examined. The nylon pipes are bent off load. In this way the probes on the chain will adjust near to the plane of bending of the pipes to be tested.

1980-01-03

90

Single parameter analysis of hysteretic magnetic flux trapping in high T{sub c} superconductor ribbon  

Energy Technology Data Exchange (ETDEWEB)

This paper described the application of an AC surface probe, similar to presently used eddy current probes, to the measurement of DC transport critical currents and critical state dissipation in high {Tc} superconductors. It has been shown that the probe can provide quantitative measurement of the full field penetration in superconducting samples by measuring the response of AC induced screening currents for superconducting materials in the form of tapes with overlayers of silver. In this manner, the AC probe can be used to replace the contact DC probe for determining critical currents in a noncontacting and local manner suitable for scanning over or along the sample.

1992-10-01

91

Single parameter analysis of hysteretic magnetic flux trapping in high T_c superconductor ribbon  

International Nuclear Information System (INIS)

This paper described the application of an AC surface probe, similar to presently used eddy current probes, to the measurement of DC transport critical currents and critical state dissipation in high T_c superconductors. It has been shown that the probe can provide quantitative measurement of the full field penetration in superconducting samples by measuring the response of AC induced screening currents for superconducting materials in the form of tapes with overlayers of silver. In this manner, the AC probe can be used to replace the contact DC probe for determining critical currents in a noncontacting and local manner suitable for scanning over or along the sample.

1992-07-19

92

Single parameter analysis of hysteretic magnetic flux trapping in high T[sub c] superconductor ribbon  

Energy Technology Data Exchange (ETDEWEB)

This paper described the application of an AC surface probe, similar to presently used eddy current probes, to the measurement of DC transport critical currents and critical state dissipation in high [Tc] superconductors. It has been shown that the probe can provide quantitative measurement of the full field penetration in superconducting samples by measuring the response of AC induced screening currents for superconducting materials in the form of tapes with overlayers of silver. In this manner, the AC probe can be used to replace the contact DC probe for determining critical currents in a noncontacting and local manner suitable for scanning over or along the sample.

1992-01-01

93

Plasma flow measurement using directional Langmuir probe under weakly ion-magnetized conditions  

Energy Technology Data Exchange (ETDEWEB)

It is both experimentally and theoretically demonstrated that ion flow velocity at an arbitrary angle with respect to the magnetic field can be measured with a directional Langmuir probe. Based on the symmetry argument, we show that the effect of magnetic field on directional probe current is exactly canceled in determining the ion flow velocity, and obtain the generalized relation between flow velocity and directional probe currents valid for any flowing direction. The absolute value of the flow velocity is determined by an in situ calibration method of the probe. The applicability limit of the present method to a strongly ion-magnetized plasma is experimentally examined. (author)

2000-07-01

94

From Quantitative Microscopy to Automated Image Understanding  

UK PubMed Central (United Kingdom)

Quantitative microscopy has been extensively used in biomedical research and has provided significant insights into structure and dynamics at the cell and tissue level. The entire procedure...Full Text Available

2004-01-01

95

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

96

The molybdenum iron-sulphur protein from Desulfovibrio gigas as a form of aldehyde oxidase.  

UK PubMed Central (United Kingdom)

The molybdenum iron-sulphur protein originally isolated from Desulfovibrio gigas by Moura, Xavier, Bruschi, Le Gall, Hall & Cammack [(1976) Biochem. Biophys. Res. Commun. 72, 782-789] has been...Full Text Available

1987-05-01

97

Spin-up of He II in a cylindrical vessel of finite height  

Energy Technology Data Exchange (ETDEWEB)

The spin-up problem of He II in a cylindrical container of infinite and finite height is considered on the basis of the Hall-Vinen-Bekarevich-Khalatnikov equations. The boundary conditions include the assumption of the generation of superfluid vorticity at the walls of the container. In the lowest order approximation with respect to viscosity, the problem is reduced to a Stefan problem for a single diffusion-type equation. Examples of solutions are given which show that the method used gives a good insight into the physical development of the spin-up flow.

1990-01-01

98

SSHS - Departments - Taught Courses - Undergraduate Prospectus - Loughborough University  

Wastenet

... Indoor facilities include a 50 metre swimming pool, various sports halls, a netball and badminton centre, a dance studio, a high performance athletics centre, the ECB National Cricket Academy, and the National Gymnastics Performance and Research Centre, whilst outdoors there are floodlit all-weather areas, a water-based ...

99

THE EFFECT OF INTERSTITIAL N ON GRAIN BOUNDARY COHESIVE STRENGTH IN Fe  

Energy Technology Data Exchange (ETDEWEB)

Increased nitrogen levels have been correlated with decreased ductility and elevated ductile-to-brittle transition temperature in pressure vessel steels [1]. However, the exact role played by nitrogen in the embrittlement of steels remains unclear. Miller and Burke have reported atom probe ion microscopy findings from neutron-irradiated low-alloy pressure vessel steel showing the presence of a 1 to 2 ruonolayer thick film of Mo, N, and C at prior austenitic grain boundaries (GB's) [2], suggesting a role for nitrogen as an intergranular embrittler. It is of interest for the development of mitigation strategies whether nitrogen must combine with other impurities to form nitride precipitates in order to exert an embrittling effect. Briant et al [1] have associated the embrittling effect of N in steels exclusively with intergranular nitride formation. This association suggests that high nitrogen levels may be acceptable if nitride ...

2003-09-22

100

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

International Nuclear Information System (INIS)

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

2004-05-15

101

Performance of a high Cr and Ni austenitic stainless steel plates in PEMFC working environments  

Energy Technology Data Exchange (ETDEWEB)

The high cost of proton exchange membrane fuel cells (PEMFCs) poses a significant challenges to their commercial uptake. The bipolar plates connect the anode and cathodes of cells and separate the reactant gases, and are the most expensive components in PEMFCs. Although stainless steel can be used as a low-cost alternative in bipolar plate construction, steel is prone to electrochemical corrosion in the highly acidic PEMFC operation process. This study examined the polarization curves and ICR as a function of compaction force of a high Cr and Ni austenitic stainless steel in an environment simulating the bipolar plate under PEMFC operating conditions. The 3-electrode system consisted of a platinum (Pt) sheet, a saturated calomel electrode with a Luggin capillary contract with the used solution and the work electrode. All polarization curves were measured in a solution of H{sub 2}SO{sub 4} in order to simulate the aggressive PEMFC environment. Surface morphologies of the steels were ...

2006-07-01

102

Microscopic properties of passive films on Ti and Zr from optical, electrochemical and SXM-measurements  

International Nuclear Information System (INIS)

A combined application of several microtechniques is presented and discussed with the Ti/TiO_2 and Zr/ZrO_2-systems as an example. All measurements were carried out on single grains of technical materials in order to detect and quantify the effect of substrate microstructure on the properties of anodic passive films formed potentiodynamically in 0.5 M H_2SO_4 (dU/dt = 20 mVs"-"1). Anisotropy-micro-ellipsometry (AME) was employed to determine the crystallographic orientation of the substrate grains along with passive film thickness and crystallinity in dependence on the anodization potential. Both the isotropic (amorphous) TiO_2- and the anisotropic (crystalline) ZrO_2-films exhibit a systematic dependence of film thickness on the grain orientation. Local LASER-scanning photocurrent measurements (#lambda#=257 nm) on the same grains likewise show a heterogeneity of the photoelectrochemical reactivity in all cases. This is quantitatively explained by the results from local electrochemical ...

1998-03-01

103

Investigating the formation mechanism of soot-like materials present in blast furnace coke samples  

Science.gov (United States)

An attempt to gain an understanding of the formation mechanism of these 'soot-like' materials has been made by means of tracing the changes in the molecular-mass distribution and molecular structure of the NMP-extractable materials from an injectant coal as well as its partially gasified chars and its pyrolytic tars. Variations in the SEC chromatograms provide clues about changes in the apparent molecular-mass distributions of these NMP extracts. Results suggest that the build-up of 'soot-like' materials follows from the secondary reactions of tars evolved from the injectant coal. The likely secondary-reaction pathways have been probed by collating structural information on these NMP extracts. The time-resolved 13-16 and 22-25 min elution fractions from the SEC column have been characterized using UV fluorescence (UV F) spectroscopy. Greater concentrations of larger aromatic ring systems are found present in samples formed under ...

2008-09-15

104

Interface engineering in chalcopyrite thin film solar devices  

Energy Technology Data Exchange (ETDEWEB)

Successful interface engineering requires compositional and electronic material characterization as a prerequisite for understanding and intentionally generating interfaces in photovoltaic devices. The paper gives an overview with several examples, all referring to Cu(In,Ga)(S,Se){sub 2} ('CIGSSe')-based solar cells, with an emphasis on characterization using highly specialized methods, such as elastic recoil detection analysis, X-ray emission spectroscopy and photoelectron spectroscopy using synchrotron and ultraviolet light for excitation, inverse photoemission spectroscopy and Kelvin probe force microscopy. First, the determination of the depth profile of the band gap energy E{sub g} in the absorber layer is demonstrated. The modification of E{sub g} towards both interfaces is discussed in terms of beneficial electronic effects. Next, the interface between absorber and buffer layers with alternative and promising non-toxic ...

2006-06-15

105

Characterization of aluminum surfaces: Sorption and etching  

Science.gov (United States)

Aluminum, due to its low density and low cost, is a key material for future lightweight applications. However, like other structural materials, aluminum is subject to various forms of corrosion damage that annually costs the United States approximately 5% of its GNP [1]. The main goal is to investigate the effects of various solution anions on aluminum surfaces, and specifically probe pit initiation and inhibition. Using surface analysis techniques including X-ray photoelectron spectroscopy, Auger electron spectroscopy, and scanning electron microscopy, results have been correlated with those obtained from electrochemical methods and a radiolabeling technique developed in the Wieckowski laboratory. Analysis of data has indicated that important variables include type of anion, solution pH, and applied electrode potential. While aggressive anions such as chloride are usually studied to elucidate corrosion processes to work ultimately toward ...

2001-01-01

106

A study of radiation embrittlement using simulation irradiation  

International Nuclear Information System (INIS)

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

2008-10-13

107

Computer modelling of eddy current probes  

International Nuclear Information System (INIS)

Computer programs have been developed for modelling impedance and transmit-receive eddy current probes in two-dimensional axis-symmetric configurations. These programs, which are based on analytic equations, simulate bobbin probes in infinitely long tubes and surface probes on plates. They calculate probe signal due to uniform variations in conductor thickness, resistivity and permeability. These signals depend on probe design and frequency. A finite element numerical program has been procured to calculate magnetic permeability in non-linear ferromagnetic materials. Permeability values from these calculations can be incorporated into the above analytic programs to predict signals from eddy current probes with permanent magnets in ferromagnetic tubes. These programs were used to test various probe designs for new testing applications. ...

1992-10-01

108

Evaluation of surgical gamma probes for sentinel node localisation in cervical and vulvar cancer  

International Nuclear Information System (INIS)

Sentinel node (SN) scintigraphy for cervical and vulvar cancer guides the gynaecological oncologist in finding the metastatic lymph nodes during lymphadenectomy. The role of the surgical gamma probe in the sentinel node concept in gynaecological oncology is to localise (SN) both intra-operatively and transcutaneously. Intra-operative hand-held collimated gamma probes are increasingly used for detection of the sentinel lymph node. A comparative evaluation of handheld gamma probes: Neoprobe 1500, Europrobe, Gamma Finder, Gamma Ray Prospector GRP1 and GPR2 was performed using different detection methods. Laboratory tests were performed in which sensitivity, spatial resolution and angular sensitivity were evaluated. The results for each gamma probe were summarised and discussed. Awareness of a gamma probes capabilities and limitations should be considered in the appropriate selection of ...

111

Transmit-receive eddy current probes for circumferential cracks in heat exchanger tubes  

Energy Technology Data Exchange (ETDEWEB)

Conventional eddy current bobbin probes are known to be ineffectual in detecting circumferential cracks in tubing. Multi-pancake and/or rotating pancake probes are required to detect circumferential cracks. It has recently been demonstrated in CANDU steam generator tubes, with deformation, ferromagnetic deposits, and copper deposits, that multi-channel probes with transmit-receive (T/R) coils are superior to those using surface impedance coils. Unlike rotating probes, the design of a new probe denoted as C3 permits fast, single-scan inspection of a full-length tube at inspection speeds comparable to conventional bobbin probes. Since 1992, the probe has been used routinely for steam generator in-service inspection at 4 CANDU plants. Defective tubes have been plugged and the units returned to service, and they continue to operate without ...

1996-01-01

112

Transmit-receive eddy current probes for circumferential cracks in heat exchanger tubes  

International Nuclear Information System (INIS)

Conventional eddy current bobbin probes are known to be ineffectual in detecting circumferential cracks in tubing. Multi-pancake and/or rotating pancake probes are required to detect circumferential cracks. It has recently been demonstrated in CANDU steam generator tubes, with deformation, ferromagnetic deposits, and copper deposits, that multi-channel probes with transmit-receive (T/R) coils are superior to those using surface impedance coils. Unlike rotating probes, the design of a new probe denoted as C3 permits fast, single-scan inspection of a full-length tube at inspection speeds comparable to conventional bobbin probes. Since 1992, the probe has been used routinely for steam generator in-service inspection at 4 CANDU plants. Defective tubes have been plugged and the units returned to service, and they continue to operate without ...

1992-01-01

113

chipD: a web tool to design oligonucleotide probes for high-density tiling arrays  

UK PubMed Central (United Kingdom)

chipD is a web server that facilitates design of DNA oligonucleotide probes for high-density tiling arrays, which can be used in a number of genomic applications such as ChIP-chip or gene-expression...Full Text Available

2010-07-01

114

Use of synthetic oligoribonucleotides to probe RNA-protein interactions in the MS2 translational operator complex.  

UK PubMed Central (United Kingdom)

Synthetic oligoribonucleotides have been used to probe the interaction of MS2 coat protein with the translational operator of the MS2 replicase gene. We have investigated the possible formation of a...Full Text Available

1990-06-25

115

Use of synthetic oligonucleotide DNA probes for identification and direct detection of Bacteroides forsythus in plaque samples.  

UK PubMed Central (United Kingdom)

Oligonucleotide DNA probes complementary to the hypervariable region of the 16S rRNA of Bacteroides forsythus were tested for their specificity and sensitivity against reference and clinical isolates...Full Text Available

1991-10-01

116

Use of an alkaline phosphatase-labeled synthetic oligonucleotide probe for detection of Campylobacter jejuni and Campylobacter coli.  

UK PubMed Central (United Kingdom)

A commercially available synthetic nucleic acid probe (SNAP) conjugated to alkaline phosphatase was compared with standard culture techniques for detecting Campylobacter species. The SNAP was able to...Full Text Available

1990-07-01

117

Rapid aneuploidy detection with multiplex ligation-dependent probe amplification: a prospective study of 4000 amniotic fluid samples  

UK PubMed Central (United Kingdom)

The introduction of prenatal screening requires rapid high-throughput diagnosis of common aneuploidies. Multiplex ligation-dependent probe amplification (MLPA) allows for quick, easily automated multiplex...Full Text Available

2009-01-01

118

Near Infrared-Fluorescent and Magnetic Resonance Imaging Molecular Probe with High T1 Relaxivity for In Vivo Multimodal Imaging  

UK PubMed Central (United Kingdom)

A new gadolinium chelating NIR fluorescent molecular probe increases T1 relaxivity of water protons, facilitating combined optical and magnetic resonance imaging.

2010-06-07

119

Improved eddy-current inspection for steam generator tubing  

Energy Technology Data Exchange (ETDEWEB)

Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generator test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking and IGA. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe ...

1989-01-01

120

Field experience with eddy current X-probes in CANDU steam generators and heat exchangers  

Energy Technology Data Exchange (ETDEWEB)

CANDU steam generators and heat exchangers have been afflicted with a significant variety of degradation mechanisms. Until recently, detection and characterization of most of the varieties of flaws required usage of several different eddy current techniques. Tubes needed to be scanned multiple times to ensure they were inspected for all possible degradation mechanisms. The time required to deploy so many different types of techniques to inspect the steam generator tubes has had a significant impact on the inspection schedules. The X-Probe was designed with an array of eddy current coils capable of detecting, characterizing and sizing axial, circumferential and volumetric flaws. The X-Probe is a fast-scanning probe with scanning speed equivalent to speeds typically used for simple bobbin coil probes. With its capability of fulfilling most if not all of the functions of the other tube-testing eddy current ...

2006-07-01

121

Field experience with eddy current X-probes in CANDU steam generators and heat exchangers  

International Nuclear Information System (INIS)

CANDU steam generators and heat exchangers have been afflicted with a significant variety of degradation mechanisms. Until recently, detection and characterization of most of the varieties of flaws required usage of several different eddy current techniques. Tubes needed to be scanned multiple times to ensure they were inspected for all possible degradation mechanisms. The time required to deploy so many different types of techniques to inspect the steam generator tubes has had a significant impact on the inspection schedules. The X-Probe was designed with an array of eddy current coils capable of detecting, characterizing and sizing axial, circumferential and volumetric flaws. The X-Probe is a fast-scanning probe with scanning speed equivalent to speeds typically used for simple bobbin coil probes. With its capability of fulfilling most if not all of the functions of the other tube-testing eddy current ...

2005-11-20

122

Electrostatic probe vacuum system for TCA BR tokamak  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the technical design and performance of the diagnostic system installed in the tokamak TCABR to measure parameters of the plasma edge. The system consists of four Langmuir probes under remote control. (author)

1999-12-01

123

Eddy Current Inspection of Mildly Ferromagnetic Tubing.  

Science.gov (United States)

The past decade has seen the development of eddy current probes for inspection of the mildly ferro-magnetic alloy Monel 400. Due to the rapid advances in permanent magnet technology similar probes have been upgraded to magnetically saturate, and hence ins...

1984-01-01

124

Detection and Analysis of Tumor Fluorescence Using a Two-Photon Optical Fiber Probe  

UK PubMed Central (United Kingdom)

The utility of a two-photon optical fiber fluorescence probe (TPOFF) for sensing and quantifying tumor fluorescent signals was tested in vivo. Xenograft tumors were developed in athymic mice using MCA207...Full Text Available

2004-06-01

125

5-Fluorodeoxyuridine as an alternative to the synthesis of mixed hybridization probes for the detection of specific gene sequences.  

UK PubMed Central (United Kingdom)

Synthetic complementary oligonucleotides are useful hybridization probes for the detection of mRNAs and genes encoding proteins for which only a partial amino acid sequence is known. Usually this involves...Full Text Available

1988-03-01

126

Synchrotron Probes of Emergent Electronic States of Matter in Solids  

ScienceCinema

...of this article he quotes um i am told by my english ...

127

Some Properties of Australian Produced Explosive ...  

Science.gov (United States)

... The rounds were initiated by an exploding bridgewire detonator (EBW) and the ionisation probes were progressively cloud by the detonation front. ...

1987-10-01

128

Signal simulator for the calibration of eddy current probes  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a signal simulator which is designed to calibrate eddy current probes. By using simultaneously an excitation coil and an electrically conducting plane, the simulator can emulate signals which correspond to spot welds with different flaws. The presence of a conducting plane allows a wide variation of the amplitude and phase of the excitation coil voltage during the calibration of a probe. A mathematical model for the simulator is derived and used to study the variation of the impedance change upon the parameters of the probe. Numerical computation shows that the impedance change depends in an important way on the frequency of the excitation coil current.

1994-01-01

130

EFFECTS OF SHIELDING ON PROPERTIES OF EDDY ...  

Science.gov (United States)

... Accession Number : ADD323869. Title : EFFECTS OF SHIELDING ON PROPERTIES OF EDDY CURRENT PROBES WITH FERRITE CUP CORES. ...

1986-08-01

131

EDDY CURRENT SIZING OF CASE DEPTH IN BEARING ...  

Science.gov (United States)

... HARDENED CUP AND CARBURIZED AND HARDENED CORES HAVE BEEN PROFILED USING 2 TYPES OF EDDY CURRENT PROBES. ...

1986-07-01

132

Simultaneous absolute and differential operation of eddy current bobbin probes for heat exchanger tube inspection  

Energy Technology Data Exchange (ETDEWEB)

Here the authors try to dissolve some commonly held misconceptions about the operation of eddy current probes used for inspecting heat exchanger tubes. With the help of computer model results, the authors demonstrate that, for optimized operation, absolute/differential probes should be operated with coil current flowing in phase with another. This month's feature should be of interest to researchers as well as for NDT field personnel.

2000-05-01

133

Evaluation of phased array UT conditions using ultrasonic visualization technique  

International Nuclear Information System (INIS)

Phased array provides many advantages over conventional ultrasonic testing method, but phased array has also limitations. This paper describes typical results of the experimental sound field analysis generated from the array probe. A photo-elastic ultrasonic visualization technique was applied in this study. The sound fields of shear wave generated from the array probe was equivalent to that from the fixed angle probe. (author)

2008-07-01

134

Array coil probe design optimization  

International Nuclear Information System (INIS)

To overcome the limitations of conventional bobbin style eddy-current probes, it has become common practice to perform some portion of a steam generator tube inspection program with array coil probes. Typically, eight surface-riding pancake coils are utilized in a probe head, either as eight independent coils (8 x 1) or in a parallel combination of four serially connected coils (4 x 4). The advantages of the array coils are improved sensitivity to intergranular attack (IGA), reduced interference from tube denting, and improved sensitivity to circumferential cracking. The current status of commercially available probes is such that several weaknesses in array coils have limited the widespread application of this technology. Task S 301-6 was conceived to address each of the weaknesses in order to produce a more reliable and cost-effective probe. The emphasis was on reliability, since ...

1987-07-01

135

Vanishing integrals for Hall-Littlewood polynomials  

CERN Document Server

It is well known that if one integrates a Schur function indexed by a partition $\\lambda$ over the symplectic (resp. orthogonal) group, the integral vanishes unless all parts of $\\lambda$ have even multiplicity (resp. all parts of $\\lambda$ are even). In a recent paper of Rains and Vazirani, Macdonald polynomial generalizations of these identities and several others were developed and proved using Hecke algebra techniques. However at $q=0$ (the Hall-Littlewood level), these approaches do not work, although one can obtain the results by taking the appropriate limit. In this paper, we develop a direct approach for dealing with this special case. This technique allows us to prove some identities that were not amenable to the Hecke algebra approach, as well as to explicitly control the nonzero values. Moreover, we are able to generalize some of the identities by introducing extra parameters. This leads us to a finite-dimensional analog of a recent result of Warnaar, ...

2010-01-01

136

Measurements of the Alfven wave spectrum in TCA  

International Nuclear Information System (INIS)

The modular and periodic antenna structure in TCA is shown to produce an extremely pure spectrum of excited waves. This purity, together with precise measurements of the antenna loading in different parts of the spectrum, has allowed us to demonstrate that it is essential to include both toroidal coupling and the Hall effect (#omega#/#omega#/sub c//sub i/not =0) in order to explain our results. We show that toroidicity produces coupling from the directly excited Vertical BarmVertical Bar = 1 wave to Vertical BarmVertical Bar = 0,2 waves. Discrete Alfven Waves are also seen for Vertical BarmVertical Bar = 0,2 in addition to the directly driven Vertical BarmVertical Bar = 1. The importance of the Hall effect is most visible when a travelling wave is excited, in which case the antenna loading depends on the direction of the wave imposed. We present the antenna loading found with different excitation structures and discuss the implications on the ...

1985-05-13

137

Liberalisation of energy markets and integration of information technology; Energiemarkt-Liberalisierung und IT-Integration. Erfolgsfaktoren und Projekterfahrungen  

Energy Technology Data Exchange (ETDEWEB)

The liberalisation of the energy markets requires completely new demands to the information processing procedure of energy supply enterprises. These requirements are to be understood as chances for strengthening of the terms of competition. In the following contribution to this subject the actual status of the concept as converted by the Electricity Supply Company of Halle (Saale) including their departments of district heating, gas and electricity supply will be presented. This concept are comprising all experiences as gathered so far as well as intended further actions to be executed. (orig.) [German] Die Liberalisierung der Energiemaerkte stellt fuer Versorgungsunternehmen voellig neue Anforderungen an die Informationsverarbeitung. Diese Anforderungen sind als Chancen zur Staerkung der Wettbewerbsfaehigkeit zu verstehen. Die Verfasser erlaeutern den aktuellen Stand des in der EVH GmbH Halle (Saale) im Querverbund der Sparten Fernwaerme, Gas ...

2003-05-19

138

Hilbert problem for a multiply connected circular domain and the analysis of the Hall effect in a plate  

CERN Document Server

In this paper we analyze the Hilbert boundary-value problem of the theory of analytic functions for an $(N+1)$-connected circular domain. An exact series-form solution has already been derived for the case of continuous coefficients. Motivated by the study of the Hall effect in a multiply connected plate we extend these results by examining the case of discontinuous coefficients. The Hilbert problem maps into the Riemann-Hilbert problem for symmetric piece-wise meromorphic functions invariant with respect to a symmetric Schottky group. The solution to this problem is derived in terms of two analogues of the Cauchy kernel, quasiautomorphic and quasimultiplicative kernels. The former kernel is known for any symmetry Schottky group. We prove the existence theorem for the second, quasimultiplicative, kernel for any Schottky group (its series representation is known for the first class groups only). We also show that the use of an automorphic kernel requires the ...

2009-01-01

139

Compressors for compressed air technique at the Hanover Fair; Komprimiertes Angebot - Kompressoren fuer die Drucklufttechnik auf der Hannover Messe  

Energy Technology Data Exchange (ETDEWEB)

Suppliers of systems and components for compressed air technique were shown at the Hanover Fair 94 in Hall 5. On about 6000 m{sup 2} floor area, they showed their product range, which covered the whole range of compressed air technique from compressors via equipment for providing and storing the compressed air to compressed air tools. (orig.) [Deutsch] Die Anbieter von Systemen und Komponenten fuer die Drucklufttechnik waren auf der Hannover-Messe `94 in der Halle 5 zu finden. Dort zeigten sie auf rund 6000 m{sup 2} ihre Produktpalette, die von Kompressoren ueber die Geraete zum Aufbereiten und Speichern der Druckluft bis zu Druckluftwerkzeugen reichte und den gesamten Bereich der Drucklufttechnik abdeckte. (orig.)

1994-06-20

140

Special eddy current probes for heat exchanger inspection  

International Nuclear Information System (INIS)

Until a decade ago, only the differential bobbin type eddy current probe was considered necessary for reliable heat exchanger tube inspection. The introduction of different tube materials, manufacturing processes and a variety of service induced failures has greatly increased the demands of eddy current testing. Optimized probe designs enhanced by improved instrumentation can help satisfy some of these demands. Some of the more difficult inspection problems are detection of circumferential cracks, fretting wear under non-ferromagnetic support plates and shallow internal defects. Reliable detection and sizing of such defects is often made more difficult by the fact they frequently occur in defect prone regions such as under tubesheets or support plates and in transition regions of finned tubes. Probe designs effective in overcoming these difficulties exist. This paper describes a number of such probes ...

1986-11-17

141

The hunt for ?13 at the Daya Bay nuclear power plant  

International Nuclear Information System (INIS)

The Daya Bay reactor neutrino experiment is located at the Daya Bay nuclear power plant in Shenzhen, China. The experiment deploys eight 'identical' antineutrino detectors to measure antineutrino fluxes from six 2.9 GWth reactor cores in three underground experimental halls at different distances. The target zone of the Daya Bay detector is filled with 20 t 0.1% Gd doped LAB liquid scintillator. The baseline uncorrelated detector uncertainty is ?0.38% using current experimental techniques. Daya Bay can reach a sensitivity of sin22?13<0.01 with baseline uncertainties after 3 years of data taking.

2010-03-30

142

Proton and deuteron spin structure function measurements in the resonance region  

Energy Technology Data Exchange (ETDEWEB)

The RSS collaboration has measured the spin structure functions of the proton and the deuteron at Jefferson Lab using the Hall C HMS spectrometer, a polarized electron beam and a polarized solid target. The asymmetries A and A were measured in the region of the nucleon resonances (0.82 GeV < W < 1.98 GeV) at an average four momentum transfer of Q2 = 1.3 GeV2. The extracted spin structure functions and their kinematic dependence will make a significant contribution in the study of higher-twist effects and polarized duality tests. A description of the experiment and the latest findings of the analysis will be presented.

2003-07-01

143

Present State of Radioactive Waste Management and Treatment Technology at the Research Centre Seibersdorf  

International Nuclear Information System (INIS)

Since 1976 the Austrian Research Centre Seibersdorf has the task to collect, treat and store radioactive waste (Radwaste) arising in Austria. Within the Department of Waste Management a variety of appropriate treatment systems are installed. For storing unconditioned and conditioned waste proper storage-halls are available. The collection of Radwaste is carried out using 100 l drums, for the conditioned waste the 200 l drum concept is used. The interim storage of conditioned waste is done at Seibersdorf until a final repository is built. The present plan foresees one to be in operation at the year 2012. (author).

1996-10-07

144

Magnetic structure of Ce(Ru_0_._9_6Pd_0_._0_4)_2Si_2  

International Nuclear Information System (INIS)

The magnetic structure of a tetragonal Ce(Ru_0_._9_6Pd_0_._0_4)_2Si_2 single crystal, determined by neutron diffraction measurements, is similar to that observed in Rh doped alloys. The magnetic moments are oriented and modulated along the c-axis. Here the wave vector is incommensurate: k=(0,0,0.38). At 1.5 K, the moment is estimated to about 0.3 #mu#_B. Magnetization, magnetoresistance and Hall effect measurements performed on this alloy are also reported. (orig.).

145

Evaluation of tritiated water retention capacity of fusion reactor concrete building  

Energy Technology Data Exchange (ETDEWEB)

In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.

1992-03-01

146

Evaluation of tritiated water retention capacity of fusion reactor concrete building  

International Nuclear Information System (INIS)

In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.

147

Evaluation of the residual radiation field in the proton accelerator facility of the Proton Engineering Frontier Project (PEFP) in Korea  

British Library Electronic Table of Contents (United Kingdom)

In Korea, the Proton Engineering Frontier Project (PEFP) is building a proton linear accelerator facility with energy up to 100MeV and a beam current of 20mA. In this study, a radiation field after shutdown in the accelerator facility of the PEFP was evaluated for the purpose of the radiation shielding by using MCNPX code. A facility modeling was performed for the accelerator tunnel building, accelerator chain, target rooms and beam experiment hall. And radiation source terms were evaluated in the facility. With this facility, model and radiation source terms, the concentration of 41Ar was evaluated and the cooling time satisfying regulation in Korea was calculated.

2007-01-01

148

Basic Design Report of DC-TOF Inelastic Neutron Spectrometer  

Energy Technology Data Exchange (ETDEWEB)

We made Basic designs of neutron guide, choppers, and detectors in order to optimize the design parameters of DC-TOF to be built in the HANARO Cold Neutron Guide Hall. In addition, we calculated the expected performance of DC-TOF using Monte Carlo simulations and evaluated the properties of neutron beam. Based on the results we obtained, we have compared the expected performance of the DC-TOF with those of existing instruments overseas. In conclusion, we believe that we will be able to construct the DC-TOF at HANARO as one of the best instruments of its kinds and it will become an invaluable instrument to researchers in the related field.

2006-04-15

149

Luminescence of Strontianite (SrCO{sub 3}) from Strontian (Scotland, UK)  

Energy Technology Data Exchange (ETDEWEB)

An historic Strontianite-type specimen from Strontian, Scotland, UK, was characterized to broaden our knowledge on luminescence properties of common carbonates. These fibrous aggregates are Strontianite (Sr{sub x}Ca{sub 1-x}CO{sub 3}) with circa 6% of CaO, interfacial water, hydrosilicate anions and substitutional divalent cations, e.g., Ca{sup 2+}, Mn{sup 2+}, Fe{sup 2+} in structural Sr{sup 2+} positions. The specimen was analyzed by X-ray Fluorescence Spectrometry (XRF), Environmental Scanning Electron Microscopy coupled with an Energy Dispersive X-ray Spectroscopy (ESEM-EDS) probe, Spatially-resolved Cathodoluminescence under the Scanning Electron Microscope (SEM-CL), Differential-Thermal Analyses (DTA), Thermogravimetry (TG), Thermoluminescence (TL), Radioluminescence (RL) and High Resolution Spectra Thermoluminescence (3DTL), to gain an overview of the spectral emissions, the defect linkages were modified by heating from room temperature ...

2009-04-15

150

Mathematical modeling of x-probe eddy current array coils used in tube inspection  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a mathematical model that calculates eddy current signals from laterally spaced transmit-receive pancake coils. This model was validated by comparing calculations with laboratory measurements and it has been applied to evaluating design variations in X-Probe eddy current array coils. This model was used to quantify detection capabilities of probe designs with different numbers of coils. The current standard X-Probe design for 13 mm (0.5 inch) diameter steam generator tubes uses 3 rows of coils with 8 coils per row. This design is commonly referred to as the '8 coil X-Probe'. A significant improvement in detection capability was predicted for an X-Probe with 12 coils per row (called the '12 coil X-Probe') detecting short circumferential crack-like flaws. Based on these calculations, a prototype 12 coil ...

2004-11-15

151

Characteristics Testing of the ECT Bobbin Probe for S/G Tube Inspection  

Energy Technology Data Exchange (ETDEWEB)

The bobbin probe technique is basically one of the important ECT methods for the steam generator tube integrity assessment that is practiced during each plant outage. The bobbin probe also is the essential component which consists of the whole ECT examination system, and provides a decisive data for the evaluation of tube integrity in compliance with acceptance criteria described in specific procedures. The selection of probe is especially important because the quality of acquired ECT data is determined by the probe design characteristics, such as geometry and operation frequency, and has an important effect on examination results. The Electric Power Research Institute (EPRI) has recently defined the procedures for the qualification of eddy current hardware and technique. These procedures provide two basic methods for qualification. Flawed tube removed from operation, or artificial flaw is required for ...

2010-05-15

152

Characteristics Testing of the ECT Bobbin Probe for S/G Tube Inspection  

International Nuclear Information System (INIS)

The bobbin probe technique is basically one of the important ECT methods for the steam generator tube integrity assessment that is practiced during each plant outage. The bobbin probe also is the essential component which consists of the whole ECT examination system, and provides a decisive data for the evaluation of tube integrity in compliance with acceptance criteria described in specific procedures. The selection of probe is especially important because the quality of acquired ECT data is determined by the probe design characteristics, such as geometry and operation frequency, and has an important effect on examination results. The Electric Power Research Institute (EPRI) has recently defined the procedures for the qualification of eddy current hardware and technique. These procedures provide two basic methods for qualification. Flawed tube removed from operation, or artificial flaw is required for ...

2010-05-01

153

Research and development on probe inserting method into steam generator helically coiled tubes for in-service inspection  

International Nuclear Information System (INIS)

Helically coiled tubes of steam generators (SG) in FBR are boundaries between sodium and water/steam. Therefore, to assure the integrity of tubes, it is necessary to inspect the tubes nondestructively for in service or after a sodium-water reaction accident. In order to make it possible to conduct in-service inspection of SG tubes, we have studied on eddy current probes and probe inserting methods. As for the probe inserting method, IHI designed a fluid driving type which consists of a model probe and signal cable with float balls and driven by air pressure force. Presented in this paper is the authors' report, which describes the fluid driving type as an effective method to insert an eddy current probe into helically coiled tubes. The outline of the test results is as follows: 1. It was possible to insert the probe into 65 meter length helically coiled tubes. ...

1979-01-01

154

Performance evaluation of corrosion probes in simulated WVNS tank 8D-2 waste: WVNS tank farm process support  

Energy Technology Data Exchange (ETDEWEB)

Five corrosion probes were received from West Valley Nuclear Services for evaluation in simulated tank 8D-2 3rd-stage sludge wash slurry. The same waste slurry simulated was also used in a series of ongoing corrosion studies assessing the effects of in-tank sludge washing on the integrity of tank 8D-2. Two of the corrosion probes were installed in the coupon corrosion test vessels operating at {approximately}150{degrees}F to compare performance of the probes with that observed by coupon tests conducted in the same vessels. Corrosion rate data calculated from electrical resistance measurements of the corrosion probes were evaluated for this study using two slightly different approaches. One approach uses the total length of exposure of the probe to give a ``time-averaged`` value of the corrosion rate. The other approach uses a shorter period of time (relative to the length of the ...

1994-07-01

155

Improvement of detectability for circumferential crack of Steam Generator tube by eddy current and ultrasonic testing method  

International Nuclear Information System (INIS)

Steam Generator (SG) tubes in PWR plant are periodically inspected using eddy current testing (ECT) method. In Japan, bobbin coil type dual function probe is used for full length inspection, but the detectability for circumferential crack is very poor, and to improve detectability for circumferential crack and supplement regular ECT, various kinds of multi segment eddy current probes and multi transducer ultrasonic testing (UT) method have been developed. ECT probes are constructed of multiple surfaceriding special winding differential type coils and UT probe consists of 16 transducers which are spaced equally around the probe circumference for 360deg wall coverage. Both of those EC and UT probes are designed effective to detect circumferential crack. On the other hand, various kinds of laboratory induced circumferential cracks have been made and destroyed to ...

1991-08-01

156

Design of the electromagnetic fluctuations diagnostic for MFTF-B  

Energy Technology Data Exchange (ETDEWEB)

The Electromagnetic Fluctuations (EMF) diagnostic will be used to monitor ion fluctuations which could be unstable in MFTF-B. Each probe assembly includes a high impedance electrostatic probe to measure potential fluctuations, and a group of nested, single turn loops to measure magnetic fluctuations in three directions. Eventually, more probes and loops will be added to each probe assembly for making more detailed measurements. The sensors must lie physically close to the plasma edge and are radially positionable. Also, probes at separate axial locations can be positioned to connect along the same magnetic field line. These probes are similar in concept to the rf probes used on TMX, but the high thermal load for 30-second shots on MFTF-B requires a water-cooled design along with temperature monitors. Each signal channel has a bandwidth of ...

1983-11-28

157

Transparent thermal insulation for a fabrication hall of LHB, Salzgitter; Transparent gedaemmte Fertigungshalle bei LHB in Salzgitter  

Energy Technology Data Exchange (ETDEWEB)

Many industrial workshops in Germany were erected during the 40s and 50s, especially at the beginning of the economic boom. After more than 40 years, these facilities are in need of structural and production-technical modernization. A case in point is the carriage fabrication workshop of the Salzgitter-based company Linke-Hoffmann-Busch. The characteristic features of this type of building are large glazed areas, free uncontrolled ventilation and substantial height. Opportunities for energy-oriented and light-technical modernization are demonstrated at this Salzgitter workshop in exemplary form, the emphasis being on the use of solar energy components and, particularly, transparent thermal insulation. (orig.) [Deutsch] In der Bundesrepublik Deutschland gibt es viele Produktionshallen, die in den vierziger und fuenfziger Jahren, insbesondere zu Beginn des wirtschaftlichen Aufschwungs, errichtet wurden. Diese Hallen sind nach ueber vierzig Jahren sowohl aus baulichen als auch ...

1997-12-31

158

The Performance Evaluation of a Hot Water Layer using a Numerical Simulation  

International Nuclear Information System (INIS)

Most of all research reactors are immerged in the deep water pool to be a ultimate heat sink. At the neighbor of the reactor, some radio-active matters, such as Na-24, Ar-41, Mg-27, Al-28 and etc, may be generated by the neutron irradiation. Those radio-active isotopes may rise up to the pool water surface through the natural convection flow, which can make the radioactivity in the reactor hall rise high enough to concern about the health of people working in the reactor hall. When the irradiation test facilities are loaded or unloaded during a normal operation, the highly radio-activated primary coolant may flow out through the irradiation test holes on the top of the reactor. This also may be a main hazard source to make the working environment of the reactor hall bad. Making a hot water layer 1.5 ? 2.0 m thick at the top of reactor pool would be a good measure to resolve that problem. The hot water layer is formed by a ...

2009-05-01

159

Structure of first- and second-stage mineralized elements in teeth of the sea urchin Lytechinus variegatus  

UK PubMed Central (United Kingdom)

Microstructure of the teeth of the sea urchin Lytechinus variegatus was investigated using optical microscopy, SEM (scanning electron microscopy) and SIMS (secondary ion mass...Full Text Available

2009-12-01

160

Peptides of human bronchial mucus glycoproteins. Size determination by electron microscopy and by biosynthetic experiments.  

UK PubMed Central (United Kingdom)

Secreted human bronchial mucins, directly collected from macroscopically healthy bronchial mucosa, were prepared in the presence of six proteinase inhibitors, and analysed by electron microscopy. These...Full Text Available

1987-11-15

161

Multi-focal optical-resolution photoacoustic microscopy in vivo  

UK PubMed Central (United Kingdom)

Although ultrasound arrays were exploited in photoacoustic imaging to improve imaging speed, ultrasound-array-based optical-resolution photoacoustic microscopy (OR-PAM) has never been achieved...Full Text Available

2011-04-01

162

Morphology and Ultrastructure of Maternal Seed Tissues of Soybean in Relation to the Import of Photosynthate  

UK PubMed Central (United Kingdom)

Cytological observations were made on developing seeds of soybean (Glycine max (L.) Merr. “Amsoy 71”) using scanning and transmission electron microscopy and light microscopy....Full Text Available

1981-05-01

163

Development and evaluation of a virtual microscopy application for automated assessment of Ki-67 expression in breast cancer  

UK PubMed Central (United Kingdom)

BackgroundThe aim of the study was to develop a virtual microscopy enabled method for assessment of Ki-67 expression and to study the prognostic value of the automated analysis in...Full Text Available

164

Conventional Microscopy vs. Computer Imagery in Chiropractic Education  

UK PubMed Central (United Kingdom)

Purpose:As human tissue pathology slides become increasingly difficult to obtain, other methods of teaching microscopy in educational laboratories must be considered. The purpose...Full Text Available

2008-01-01

165

Compact Image Slicing Spectrometer (ISS) for hyperspectral fluorescence microscopy  

UK PubMed Central (United Kingdom)

An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated...Full Text Available

2009-07-20

166

Transmit-receive eddy current probes  

International Nuclear Information System (INIS)

In the last two decades, due to increased inspection demands, eddy current instrumentation has advanced from single-frequency, single-output instruments to multifrequency, computer-aided systems. This has significantly increased the scope of eddy current testing, but, unfortunately, it has also increased the cost and complexity of inspections. In addition, this approach has not always improved defect detectability or signal-to-noise. Most eddy current testing applications are still performed with impedance probes, which have well known limitations. However, recent research at AECL has led to improved eddy current inspections through the design and development of transmit-receive (T/R) probes. T/R eddy current probes, with laterally displaced transmit and receive coils, present a number of advantages over impedance probes. They have improved signal-to-noise ratio in the presence of variable lift-off ...

1997-10-27

169

Experimental studies on a structure of eddy current probe for detection of magnetic flux disturbed by a flaw  

International Nuclear Information System (INIS)

Bobbin-coil-type eddy current probes, which are conventionally used for nondestructive inspection of steam generator tubes in pressurized-water-type nuclear power plants, have poor detectability for circumferential flaws. Hence a new type of eddy current probe was proposed to detect effectively the magnetic flux component disturbed by a flaw and thus to eliminate the flaw direction dependency on the flaw detectability. In the course of development of the proposed method, structures of the probe were investigated based on the measurement of magnetic fields induced by exciting flat coils with several shapes. The new type of probe proposed here consists of differential pick-up coils detecting magnetic flux and exciting coils having a parallelogrammic shape, and its structure was fabricated experimentally in order to detect flaws independently of their directions. Nondestructive flaw detection tests was ...

1995-01-01

170

Understanding the operation and use of high temperature electrochemical corrosion rate probes  

Energy Technology Data Exchange (ETDEWEB)

Electrochemical corrosion rate probes were constructed and tested along with mass loss coupons in a N2/O2/CO2 plus water vapor environment. Temperatures ranged from 450 to 600 C. Corrosion rates for ash-covered mild steel, 304L SS, and 316L SS probes using electrochemical techniques were a function of time, temperature, and process environment. Correlation between electrochemical and mass loss corrosion rates was good.

2004-01-01

171

The electron current to a Langmuir Probe in a flowing high-pressure plasma  

International Nuclear Information System (INIS)

This paper reports on the electron current to a Langmuir probe in a moving high-pressure plasma. The plasma is an atmospheric-pressure propane flame, and the probe's speed relative to the plasma is varied from 10 to 30 ms"-"1. The current is linearly dependent on the speed and appears to be comprised of two components - one driven by diffusion and the other by convection. A model is devised which can be used to measure the electron density. By comparing the density computed from this model to that measured from the ion current, it has been possible to measure the electron mobility in the flame gases. The value obtained here is in good agreement with theoretical calculations found in the literature.

172

Finite element prediction of differential eddy current probe signals from Fe _30_4 deposits in PWR steam generators  

International Nuclear Information System (INIS)

The paper is concerned with the simulation of practical testing situations which are too difficult and/or expensive to replicate in a laboratory environment. Numerical experiments are described which simulate the differential eddy current probe response to the build-up and chemical flushing of magnetite in the crevice gap of a PWR steam generator unit. The simulation results agree well with the only experimental data available to the authors and lead to the conclusion that conventional differential eddy current probes should be capable of characterizing crevice gap conditions with respect to the presence of magnetite. (author).

1985-01-01

173

D-brane probe and closed string tachyons  

International Nuclear Information System (INIS)

We consider a D-brane probe in the unstable string background associated with flux branes. The twist in the spacetime metric reponsible for supersymmetry breaking is shown to manifest itself in the mixing of open Wilson lines with the phases of some adjoint matter fields, resulting in a nonlocal and nonsupersymmetric form of Yang-Mills theory as the probe dynamics. This provides a setup where one can study the fate of a large class of unstable closed string theories that includes as a limit type 0 theories and various orbifolds of type II and type 0 theories. We discuss the limit of C/Z_n orbifold in some detail and speculate on the couplings with closed string tachyons.

2002-04-15

174

NEXAFS microscopy of polymeric materials: Successes and challenges encountered when characterizing organic devices  

Energy Technology Data Exchange (ETDEWEB)

We summarize recent developments in x-ray microscopy of polymers by focusing on the characterization of organic electronic devices. The quantitative compositions of model polymer blends have been mapped at a resolution of {approx}35 nm. Since it could be inferred that these devices have structures smaller than 35 nm, quantitative compositional mapping at length scales below the present resolution limit of x-ray microscopy is required. Organic devices thus serve to both highlight the success of NEXAFS microscopy to date, but to also outline the very real need for higher spatial resolution. New approaches to create improved optics or different acquisition modalities are required if x-ray microscopy is to make sustained contributions to such an important area of research as organic devices.

2009-09-01

175

hh911.cpr  

Science.gov (United States)

"ID# ","Measurement ID Number " "DATE ","Date " "JDATE ","Julian Date " "TIME ", "Local Time " "GMT ","Greenwich Mean Time " "BAND ","Dielectric Probe Band ...

176

X-ray Emission as a Probe of the Wind-Driven Shock in WR 140  

Science.gov (United States)

single star evolution. To understand the evolution of massive stars and their role in shaping the galaxy, understanding of the distribution of ...

177

X-15 Research Results: Chapter 9  

Science.gov (United States)

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

179

SQUID Eddy Current Technique Applying Conformable Eddy ...  

Science.gov (United States)

... Accession Number : ADD344580. Title : SQUID Eddy Current Technique Applying Conformable Eddy Current Probes,. Corporate Author : ...

180

SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP - LAMBDA - NASA  

Science.gov (United States)

of the determinant of the parameter covariance matrix for each ... parameter covariance matrix, as obtained from the Markov chains. The basic set ...

181

Performance Evaluation of Several Types of Pulsed Eddy Current Probes for Detecting Wall Thickness Reduction  

Science.gov (United States)

In this paper, four different types of pulsed eddy current (PEC) probe are designed and their performance of detecting wall thickness reduction is compared. By using the backward difference method in time and the finite element method in space, PEC signals from various thickness and materials are numerically calculated and three features of the signal are selected. Since PEC signals and features are obtained by various types and sizes of probe, the comparison is made through the normalized features which reflect the sensitivity of the feature to thickness reduction. The normalized features indicate that the shielded reflection probe provides the best sensitivity to wall thickness reduction for all three signal features. Results show that the best sensitivity to thickness reduction is achieved by the peak value, but also suggest that the time to peak can be a good candidate because of its linear relationship with the ...

2010-02-01

182

Molecular spectroscopy and planetary atmospheres  

Energy Technology Data Exchange (ETDEWEB)

With the improvements accomplished during the past 15 years in detection techniques and instrumentation and with the opening of space exploration, molecular spectroscopy has become a very efficient way to probe planetary atmospheres.

1984-01-01

183

Improved eddy-current inspection for steam generator tubing  

International Nuclear Information System (INIS)

Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generators test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking, and intergranular attack. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different ...

1990-03-01

184

Final Report of OT-45, PVM-8, and RVTO Weather ...  

Science.gov (United States)

... A second hydrometeor sampler (MRI Model 1220 ... The cloud particle probe normally installed in ... to the northeast showed no significant movement. ...

1975-07-01

185

Development of a Suite of Luciferase Gene Probes for the ...  

Science.gov (United States)

... between 2 strains is acquired by adding the lengths of the connecting branches, using the scale which depicts 1 amino acid substitution per 10 ...

2011-05-15

186

Development of a FeCoNb Alloy to be used in Eddy Current ...  

Science.gov (United States)

... Accession Number : ADD336001. Title : Development of a FeCoNb Alloy to be used in Eddy Current Probes for Testing Ferromagnetic Tubes,. ...

187

Development of New Ground Inspection Techniques for the ...  

Science.gov (United States)

Integration of Eddy Current probes with MAUS scanning system has been demonstrated to produce scan rates of 36 sqft/hour. System will be designed to ...

188

Deep Space Probe Science Experiment  

Science.gov (United States)

Briefly, 48 MOS microparticle sensors (essentially the same as those flown on .... at the Naval Research Lab to interpret the polarization of the incoming radio .... Adapter Satellite, to be published in Journal of Spacecraft and Rockets, 1994. ...

189

Automated Eddy Current Inspection of Space Shuttle APV ...  

Science.gov (United States)

... perform the inspection in the extremely limited space between adjacent blades and at the blade root, miniature eddy current probes were developed ...

190

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

191

Transport properties of Nd{sub 7}Ni{sub 3}  

Energy Technology Data Exchange (ETDEWEB)

Electrical resistivity of Nd{sub 7}Ni{sub 3} shows anomalies at the Neel temperature T{sub N} = 29 K and the Curie temperature T{sub C} = 14 K but does not show any change at the spin reorientation temperature T{sub R} = 8.7 K. The thermoelectric power has also bro[ humps around 250 and 50 K as well as a sharp break at T{sub N} and a minimum at 10 K. The corresponding Hall coefficient shows anomalies at T{sub N}, T{sub C} and T{sub R}, following the Curie-Weiss-law-like behavior above T{sub N}. (orig.) 7 refs.

1998-01-01

192

The Effect of Contacts on the Counting Characteristics of Heavily Doped Normal-Type Cadmium-Telluride  

Science.gov (United States)

Cadmium telluride single crystals were grown heavily doped with chloride by the THM method. The resulting crystals were n-type with free carrier concentrations of the order of 10('12)/cm at room temperature. Hall effect studies revealed room temperature mobilities between 30 and 350 cm('2)/v-sec and resistivites between 2 x 10('3) and 10('4) ohm-cm. Studies were made of the gamma and alpha counting characteristics of these crystals with metal, metal-semiconductor, and metal-insulator electrodes. It was found that the MIS and MSS structures resulted in significant improvement over the MS structures in counting, signal-to-noise and energy resolution.

1985-01-01

193

Study of duality in the transition region at Jlab  

Energy Technology Data Exchange (ETDEWEB)

Inclusive double spin asymmetries obtained by scattering polarized electrons off polarized protons and deuterons have been analyzed to address the issue of quark-hadron duality in the polarized spin structure functions g^p_1 and g^d_1. A polarized electron beam, solid polarized NH_3 and ND_3 targets and the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B were used to collect the data. The resulting g^p_1 and g^d_1 were averaged over the nucleon resonance energy region (M < W < 2.00 GeV), and three lowest lying resonances individually for tests of global and local duality.

2007-01-01

194

Social involvement and development as a response to the campus student culture  

British Library Electronic Table of Contents (United Kingdom)

Given the widely accepted notion of whole person education in Confucian societies such as Hong Kong, Mainland China and Singapore, it is surprising that research literature originated in these societies pays little attention to how students learn and develop through out-of-class experiences at university. There is little research evidence on how the prevailing culture among student social communities (residential halls and student societies/clubs) influences students? social involvement and development. This paper examines 42 Chinese students? social experiences and development during their freshman year at a Hong Kong university. The majority of them were intensively involved in out-of-class activities. Their active social involvement was both a response to the culture of student communit...

2011-01-01

195

Reliability-based robustness analysis for a Croatian sports hall  

British Library Electronic Table of Contents (United Kingdom)

This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness and a simplified mechanical system modelling of a timber truss system. A complex timber structure with a large number of failure modes is modelled with only a few dominant failure modes. First, a component based robustness analysis is performed based on the reliability indices of the remaining elements after the removal of selected critical elements. The robustness is expressed and evaluated by a robustness index. Next, the robustness is assessed using system reliability indices where the probabilistic failure model is modelled by a series system of parallel systems.

2011-01-01

196

Progress Report Towards the ICANOE Detector  

CERN Document Server

We present a proposal for a combined ICARUS & NOE general purpose detector, to be installed in Hall B of the Gran Sasso Laboratory.The main scientific goal is the one of elucidating in a comprehensive way the pattern of neutrino $9 masses and mixings, following both (1) the S-KAM results and (2) the predictions on atmospheric neutrinos of the large solution of the Solar Neutrinos deficit. To achieve these goals, the experimental method is based upon the $9 complementary and simultaneous detection of CERN beam (CNGS) and cosmic ray (CR) events. This is made possible because of the complete isotropy of the detection technique. For the currently allowed values of the S-KAM results, both $9 CNGS and cosmic ray data will give independent measurements and provide a precise $(sin^{2}2\\theta; \\Delta m^{2})$ determination rather than a wide band of allowed values. Since we can observe and unambiguously identify $9 $\

1999-01-01

197

Planar QED at finite temperature and density: Hall conductivity, Berry's phases and minimal conductivity of graphene  

CERN Document Server

We study 1-loop effects for massless Dirac fields in two spatial dimensions, coupled to homogeneous electromagnetic backgrounds, both at zero and at finite temperature and density. In the case of a purely magnetic field, we analyze the relationship between the invariance of the theory under large gauge transformations, the appearance of Chern-Simons terms and of different Berry's phases. In the case of a purely electric background field, we show that the effective Lagrangian is independent of the chemical potential and of the temperature. More interesting: we show that the minimal conductivity, as predicted by the quantum field theory, is the right multiple of the conductivity quantum and is, thus, consistent with the value measured for graphene, with no extra factor of pi in the denominator.

2009-01-01

198

Microstructure and mechanical behaviour of an elevated temperature Mg-rare earth based alloy  

International Nuclear Information System (INIS)

AM-SC1 is a heat treatable magnesium alloy that has been specifically developed to achieve the elevated temperature strength and creep properties necessary for engine block applications. This paper describes the interrelationship between the microstructure and the mechanical properties of AM-SC1. The compressive and tensile strengths are relatively insensitive to temperature up to and including 450 K and the tensile yield behaviour deviates from a standard Hall-Petch relationship at grain sizes below 200 ?m. The microstructural features contributing to the creep resistance are both inter- and intra-granular in nature and are on length scales from nanometers to micrometers. The creep behaviour at 423 K and 450 K is diffusion controlled, with any contribution from the grain boundaries being negligible.

2009-04-15

199

Hydromagnetic free convection currents effects on boundary layer thickness  

Energy Technology Data Exchange (ETDEWEB)

In this study we discuss an unsteady free convection MHD flow past semi-infinite vertical porous plate. We have considered the flow in the presence of a strong magnetic field and therefore the electromagnetic force is very large. This brings in the phenomenon of Hall and Ion-slip currents. The effects of these two parameters together with that of viscous dissipation and radiation absorption among others on velocity, temperature and concentration profiles are presented. The profiles are presented graphically. As the partial differential equations governing this problem are highly non-linear they are solved numerically by a finite difference method. It is found that in presence of heating of the plate by free convection current the velocity boundary layer thickness decreases.

2010-06-15

200

Hydromagnetic free convection currents effects on boundary layer thickness  

British Library Electronic Table of Contents (United Kingdom)

In this study we discuss an unsteady free convection MHD flow past semi-infinite vertical porous plate. We have considered the flow in the presence of a strong magnetic field and therefore the electromagnetic force is very large. This brings in the phenomenon of Hall and Ion-slip currents. The effects of these two parameters together with that of viscous dissipation and radiation absorption among others on velocity, temperature and concentration profiles are presented. The profiles are presented graphically. As the partial differential equations governing this problem are highly non-linear they are solved numerically by a finite difference method. It is found that in presence of heating of the plate by free convection current the velocity boundary layer thickness decreases.

2010-01-01

201

Fractional domain walls from on-site softening in dipolar bosons  

CERN Document Server

We study dipolar bosons in a 1D optical lattice and identify a region in parameter space---strong coupling but relatively weak on-site repulsion---hosting a series of stable CDW states whose low-energy excitations, built from "fractional domain walls", are remarkably similar to those of non-abelian fractional quantum Hall states. Here, a conventional domain wall between translated CDW's may split by inserting strings of degenerate, but inequivalent, CDW states. Outside these insulating regions, we find numerous supersolids as well as a superfluid regime. The mentioned phases should be accessible experimentally, and in particular, the fractional domain walls can be created in the ground state using single-site addressing, i.e. by locally changing the chemical potential.

2011-01-01

202

British Nuclear Fuels PLC: report and accounts 1988-89  

International Nuclear Information System (INIS)

This item covers a meeting held between members of the United Kingdom government's energy committee and representatives of British Nuclear Fuels (BNFL) to discuss their Annual Report and Accounts for the year 1988-89. The committee explored the reasons for escalating predictions of the costs of nuclear power and why decommissioning costs are so difficult to estimate accurately so as to include them in cost per kilowatt hour of generated electricity. The relationship between BNFL and the Ministry of Defence (MoD) was explored, as was the MoD's relationship with the United States Department of Defense. BNFL's financial position should improve when the thermal oxide reprocessing plant at Sellafield becomes operational, and the Chapelcross and Calder Hall reactors may contribute income from electricity generation. (UK).

203

Bloch-Boltzmann analysis of electrical transport in intermetallic compounds: ReO[sub 3], BaPbO[sub 3], CoSi[sub 2], and Pd[sub 2]Si  

Energy Technology Data Exchange (ETDEWEB)

The shape and magnitude of the electrical resistivity [rho]([ital T]) is analyzed for four intermetallic compounds, and electron-phonon coupling constants [lambda] are extracted. ReO[sub 3] is particularly interesting because a sharp departure from the Bloch-Grueneisen shape can be attributed to high-frequency optical vibrations. The [lambda] values for the oxide metals seem too large to be consistent with the absence of superconductivity, but the results generally agree well with a conventional Fermi-liquid interpretation. The Hall coefficient [ital R][sub [ital H

1993-06-01

204

Ageing of fibre reinforced polymer composite selected as a bearing material for Rams of 540 MWe fuelling machine  

International Nuclear Information System (INIS)

Fibre-reinforced-polymer-composite material has been suggested as a bearing material to overcome tribological problems witnessed during the testing of Ram assembly of the 540 MWe fuelling machine at RTD. After successful trials at B-Ram the composite material has been adapted for B-RAM, C-Ram and RDB head at fuelling machines being tested at RTD, Hall 7 and at Tarapur. Laboratory evaluations were also carried out at Tribology Lab RTD to study effect of radiation on the composite. Paper deals with the various aspects of life prediction of this material in term of wear and radiation damage. (author)

2006-11-01

205

Advanced Neutron Source: Plant Design Requirements  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this PDR document and the set of SDD documents will define and ...

1990-07-01

206

A phenomenological model for the macroscopic characteristics of irradiated silicon  

International Nuclear Information System (INIS)

The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.

207

Use of Eu"3"+ as an oxygen environment probe in alkali-alkaline earth-lanthanide phosphates with the #beta#-K_2SO_4 structure  

International Nuclear Information System (INIS)

The use of europium as a local structural probe allows the various phases appearing in the NaCaPO_4-Na_3Eu(PO_4)_2 and NaSrPO_4-Na_3Eu(PO_4)_2 systems to be detected. The broadening of the europium emission lines in going from the calcium to the strontium phases illustrates the ease of displacement of the PO_4 groups. (Auth.).

1983-09-01

208

The fatty acid analogue 11-(dansylamino)undecanoic acid is a fluorescent probe for the bilirubin-binding sites of albumin and not for the high-affinity fatty acid-binding sites.  

UK PubMed Central (United Kingdom)

1. The fluorescent fatty acid probe 11-(dansylamino)undecanoic acid (DAUDA) binds with high affinity to bovine and human serum albumin (BSA and HSA) at three sites. 2. The Kd of the primary binding...Full Text Available

1990-08-15

209

Surface probe measurements in ISX-B and EBT-S  

Energy Technology Data Exchange (ETDEWEB)

Surface deposition probe techniques have been shown to be an effective means of determining the characteristics of the plasma edge region of magnetic confinement devices. Experimental results on ISX-B and EBT-S have led to a consistent picture of the edge plasma and the dominant impurity introduction mechanisms. This picture is supported by numerous other measurements and emphasizes the importance of concentrating several techniques on the complex problems of plasma fusion.

1982-12-01

210

Non-destructive measurement of corrosion effects on high temperature coatings  

Energy Technology Data Exchange (ETDEWEB)

Non-destructive methods for measuring the remaining anticorrosive or antioxidative ability of coatings are investigated. For anticorrosive chromium coatings the increasing ferromagnetism caused by loss of chromium is measured by a permeability probe. Measured values on blades after operation are correlated with the progress of corrosion as determined by metallographic methods. For antioxidative aluminum coatings the diminishing layer thickness is taken as indication for the exhaustion of their protection ability. The layer thickness is measured eddy current probes, especially developed for this application.

1990-01-01

211

Hybridization with synthetic oligonucleotides  

Science.gov (United States)

Procedures are described for the use of synthetic oligonucleotides for Southern blot experiments and gene bank screening, and the effect of various mismatches on the efficiency of hybridization is demonstrated. The following topics are discussed: sensitivity vs. specificity, hybridization of a 12-mer to the lambda endolysin gene; hybridization of oligonucleotide probes to the E. coli lac operator; hybridization of synthetic probes to the CYC1 gene of yeast; and cloning eucaryotic genes. (HLW)

1978-01-01

212

Experimental study on the uses of SQUID magnetometers as sensitive, low-frequency eddy current probes for non-destructive materials evaluation. Final report  

International Nuclear Information System (INIS)

The results show that the SQUID device eddy current testing system is a suitable tool for NDE. Due to the high low-frequency sensitivity of the SQUID sensor, the SQUID device eddy current testing system permits lower examination frequencies than the conventional eddy current probe system. The SQUID system enhances fault detection in even deeper materials layers. (orig./MM).

1996-01-01

213

Eddy current testing of CFRP; New probes and techniques. Wirbelstrompruefung von Kohlefaser-Kompositen; Neue Sonden und Messverfahren  

Energy Technology Data Exchange (ETDEWEB)

Nondestructive inspection of carbon fibre-reinforced plastics (CRFP) using eddy current methods is based not only on the conductivity of the fibres. High frequencies (up to 10 MHz) give access to capacitive effects reflecting properties of the matrix. The paper presents a method using rotating eddy current probes to measure the anisotropic electrical properties. Potential applications of this method are the structural identification of laminates and the estimating of its degradation. (orig.)

1994-01-01

214

Diagnosis of early human myocardial ischemic damage with electron probe microanalysis  

Energy Technology Data Exchange (ETDEWEB)

We determined the Na/K x-ray intensity ratio in frozen sections of myocardial tissues obtained at autopsy from patients who died from various causes, using electron probe analysis. We have been able to distinguish between the ischemically injured and normal cells. The method is simple, fast, and dependable even when the duration of ischemia is only 30 minutes.

1983-03-01

215

Characterization of eddy current probes used in steam generator tubes inspection  

International Nuclear Information System (INIS)

In in-service inspection of steam-generator tubes, the need for reproducibility of the measurement results and for comparison of these results over two successive inspections has led EDF to specify the main characteristics of the eddy-current probes and to design equipment to measure them. This equipment is presented here and the electrical and magnetic results are correlated with those obtained by testing tubes with reference defects.

1985-02-01

216

Characterization of Eddy Current probes used in steam generator tubes inspection  

International Nuclear Information System (INIS)

In in-service inspection of steam-generator tubes, the need for reproducibility of the measurement results and for comparison of these results over two successive inspections has led EDF to specify the main characteristics of the Eddy-Current probes and to design equipment to measure them. This equipment is presented here and the electrical and magnetic results are correlated with those obtained by testing tubes with reference defects. 5 refs.

1985-02-01

217

A study of the eddy-current method of testing the level of molten steel in the thin-slab crystallization process  

British Library Electronic Table of Contents (United Kingdom)

An eddy current probe of the level of molten metal is considered for a sectional machine of continuous casting of steel. The advantages of electromagnetic probes of the level over radiometric ones lie in their insensitivity to the layer of dross and high speed. The results and directions of further studies are given.

2009-01-01

218

Use of DNA probes to study tetracycline resistance determinants in gram-negative bacteria from swine  

Energy Technology Data Exchange (ETDEWEB)

Specific {sup 32}P-labeled DNA probes were prepared and used to evaluate the distribution of tetracycline resistance determinants carried by gram-negative enteric bacteria isolated from pigs in 3 swine herds with different histories of antibiotic exposure. Plasmid DNA, ranging in size from 2.1 to 186 Kb, was observed in over 84% of 114 isolates studied. Two of 78 tetracycline resistant strains did not harbor plasmids. The DNA probes were isolated from plasmids pSL18, pRT29/Tn10, pBR322 and pSL106, respectively, and they represented class A, B, C and D tetracycline resistance determinants. Hybridization conditions using 0.5X SSPE at 65{degrees}C minimize cross-hybridization between the different class of tetracycline resistance genes. Cross-hybridization between class A and class C determinants could be distinguished by simultaneous comparison of the intensity of their hybridization signals. Plasmids from over 44% of the tetracycline resistant ...

1989-01-01

219

Geometrically anisotropic probes: an improved eddy current technique  

Energy Technology Data Exchange (ETDEWEB)

Geometrically anisotropic eddy current probes are a type of separate function probes especially fit to the detection of defects showing a preferential direction. This kind of flaw induces a coupling between the transmitter and the receiver by guiding eddy currents from the one to the other. On the other hand, this coupling will be almost non-existent in the presence of defects or spurious effects not displaying this geometrical particularity. Basic studies on an elementary two-coil set-up allow the acknowledgment of the intrinsic qualities of such probes: good signal-to-noise ratio, influence field practically constant on the whole defect length, ability to detect bridged defects, insensitivity to lift off. These results can be improved by achieving multicoils probes adapted to different kinds of problems. An application to continuous casting slabs testing yields very interesting results in the ...

1987-06-01

220

abstract - 2008 NASA Carbon Cycle and Ecosystems Joint Science ...  

Science.gov (United States)

Microscopy and chemotaxonomy from HPLC analysis of phytoplankton pigments initiated in 2003 suggest that Noctiluca miliaris blooms are becoming more intense ...

221

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

International Nuclear Information System (INIS)

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

2006-02-22

222

The determination of particulate contamination in miniature ball bearings  

Energy Technology Data Exchange (ETDEWEB)

A method is described for determining the particulate contamination in miniature ball bearings in which the bearing is flushed with a solvent that is then filtered. The particles that are collected on the filter are examined by optical microscopy.

1992-12-01

223

Scanning Electron Microscopy of Sarcophagid (Diptera) Larvae Recovered from a Case of Human Cutaneous Myiasis  

Science.gov (United States)

... point dried and mounted on aluminum stubs using colloidal silver paste. Mounted specimens were observed and photographed using ... ...

224

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

225

Molecular Microscopy of Brain Gangliosides: Illustrating their Distribution in Hippocampal Cell Layers  

UK PubMed Central (United Kingdom)

Gangliosides are amphiphilic molecules found in the outer layer of plasma membranes of all vertebrate...Full Text Available

2011-02-21

226

Medium voltage analytical electron microscopy microanalysis versus radiation damage  

Energy Technology Data Exchange (ETDEWEB)

The kinetic energy transferred to some elements by an electron of kinetic energy 100 to 400 kV is discussed. The displacement rates are compared to the signal generation. (DCL)

1985-09-01

227

High-energy x-ray microscopy techniques for laser-fusion plasma research at the National Ignition Facility  

Energy Technology Data Exchange (ETDEWEB)

Multi-kilo-electron-volt x-ray microscopy will be an important laser-produced plasma diagnostic at future megajoule facilities such as the National Ignition Facility (NIF). However, laser energies and plasma characteristics imply that x-ray microscopy will be more challenging at NIF than at existing facilities. We use analytical estimates and numerical ray tracing to investigate several instrumentation options in detail, and we conclude that near-normal-incidence single spherical or toroidal crystals may offer the best general solution for high-energy x-ray microscopy at NIF and similar large facilities. Apertured Kirkpatrick{endash}Baez microscopes using multilayer mirrors may also be good options, particularly for applications requiring one-dimensional imaging over narrow fields of view. {copyright} 1998 Optical Society of America

1998-04-01

228

(Hadamard transform imaging)  

Science.gov (United States)

This report describes the design of, and image reconstruction capacity of a Hadamard Raman Microscopic imager. Microscopy of benzoic acid and graphite electrodes, as well as electrophoretic blotting, are described. (CBS)

1990-01-01

229

Yttrium doped La_1_-_xY_xO_0_._9F_0_._1FeAs superconductors: Hall and thermopower studies  

International Nuclear Information System (INIS)

The effect of yttrium substitution at the lanthanum site on the superconducting properties of La_1_-_xY_xO_0_._9F_0_._1FeAs ('x' = 0, 0.10, 0.20, 0.30, 0.50 and 0.60) oxypnictides has been studied. Powder X-ray diffraction studies confirm single phases till x = 0.1 beyond which minor amount of Y_2O_3 is observed. The temperature dependence of resistivity measurements confirm the superconducting transition temperature (T_c) of 34.8 (#+-#0.05) K and corresponding Meissner transition at 34.3 K in the 'x' = 0.3 composition which is higher than that reported for the parent phase (LaO_0_._9F_0_._1FeAs (T_c = 28 K)). Further increase in the concentration of yttrium leads to broadening and suppression of the superconducting transition. The value of H_c_2 at zero temperature is estimated to be about 60.5 T. The Seebeck coefficient (S) shows a negative sign indicating that the major contribution to the conductivity is by electrons. The Hall coefficient (R_H) also remains ...

2010-06-01

230

Si and Si/P implants in In{sub 0.5}Ga{sub 0.5}P and In{sub 0.5}Al{sub 0.5}P  

Science.gov (United States)

Si and Si/P ion implantation doping of In{sub 0.5}Ga{sub 0.5}P and In{sub 0.5}Al{sub 0.5}P has been studied for several Si and P doses at energies of 90 and 100 keV, respectively. For single Si implants in InGaP a maximum Hall sheet electron concentration of 1.33{times}10{sup 13} cm{sup {minus}2} is achieved for a Si dose of 5{times}10{sup 13} cm{sup {minus}2}. When an optimum dose (2.5{times}10{sup 13} cm{sup {minus}2}) P coimplant is performed this electron concentration is increased by 65{percent}. The same dose Si implants in InAlP show a maximum effective activation of 3.9{percent} with no P coimplantation and 5.2{percent} with a P-implant dose 1.5 times the silicon dose. The apparent donor ionization energies are estimated from variable temperature Hall measurements to be 2{endash}5 meV for InGaP and {approximately}80 meV for InAlP. The deeper level in InAlP is attributed to the DX level found in the Al-containing material. The reduction ...

1996-06-01

231

Electronic topological transition in an n-BiSb semiconductor alloy in the quantum limit range of magnetic fields for H-parallel C{sub 2}  

Science.gov (United States)

The galvanomagnetic properties of single-crystal samples of the Bi{sub 0.93}Sb{sub 0.07} semiconductor alloy with the electron density n = 1.6 x 10{sup 17} cm{sup -3} in magnetic fields up to 14 T at T = 1.6 K have been investigated. The resistivity {rho} and Hall coefficient R have been measured as functions of the magnetic field directed along the binary axis of a crystal for a current flowing through a sample along the bisector axis; i.e., the components {rho}{sub 22} and R{sub 32,1} have been measured. The strong anisotropy of the electron spectrum of the samples makes it possible to separately observe quantum oscillations of the magnetoresistance {rho}{sub 22}(H) for H -parallel C{sub 2} in low magnetic fields for two equivalent ellipsoids with small extremal cross sections (secondary ellipsoids) and in high magnetic fields for electrons of the ellipsoid with a large extremal cross section (main ellipsoid). An increase in the energy of the electrons of ...

2010-08-15

232

Analysis of enclosed sodium pool fire scenario in sodium fire experimental facility  

International Nuclear Information System (INIS)

Liquid sodium is used as coolant in Fast Breeder Reactors (FBR). There is a likelyhood of sodium spillage in ambient air in the Steam Generator Building (SGB) of the FBR plant. Due to high chemical reactivity with oxygen, especially at temperatures greater than 573 K, it catches fire very easily. In order to carryout safety related experimental studies for different modes of sodium fires and to develop suitable mathematical models for the assessment of their consequences, an experimental facility (SFEF, Sodium Fire Experimental Facility) is being setup a IGCAR, Kalpakkam. The SFEF is having a 540 m"3 volume experimental hall. Stainless steel linear will be provided on the inside surfaces of experimental hall walls, ceiling and floor. Analysis has been carried out for enclosed sodium pool fire scenarios in SFEF by using sodium pool fire code SOFIRE II, which estimates the thermal transients like pressure rise, gas temperature rise, cell wall ...

2007-04-22

233

Eddy current array probe for detection of surface breaking cracks in the extrados of feeder bends  

Energy Technology Data Exchange (ETDEWEB)

A new eddy current array probe has been implemented as a straightforward and promising technique for detection of outer diameter (OD) surface-breaking cracks on the extrados of feeder bends. The design is based on previous work performed at AECL, which had demonstrated that eddy current probes with laterally displaced transmit-receive coils can overcome some of the limitations of inspecting ferritic steel components for surface-breaking cracks. The Feeder Integrity Joint Program-CANDU Owners Group Inc. (FIJP-COG) Non-Destructive Evaluation (NDE) Team members commissioned AECL to work in collaboration with the probe manufacturer ZETEC, to develop a field usable eddy current array probe. The objective was to acquire a technique with the following capabilities: fast scanning non-contact inspection technique for surface breaking discontinuities; full inspection of the bend extrados OD surface in a single ...

2006-07-01

234

Eddy current array probe for detection of surface breaking cracks in the extrados of feeder bends  

International Nuclear Information System (INIS)

A new eddy current array probe has been implemented as a straightforward and promising technique for detection of outer diameter (OD) surface-breaking cracks on the extrados of feeder bends. The design is based on previous work performed at AECL, which had demonstrated that eddy current probes with laterally displaced transmit-receive coils can overcome some of the limitations of inspecting ferritic steel components for surface-breaking cracks. The Feeder Integrity Joint Program-CANDU Owners Group Inc. (FIJP-COG) Non-Destructive Evaluation (NDE) Team members commissioned AECL to work in collaboration with the probe manufacturer ZETEC, to develop a field usable eddy current array probe. The objective was to acquire a technique with the following capabilities: fast scanning non-contact inspection technique for surface breaking discontinuities; full inspection of the bend extrados OD surface in a single ...

2005-11-20

235

Characterization of axial probes used in eddy current testing; Caracterisation des sondes axiales utilisees en courants de foucault  

Energy Technology Data Exchange (ETDEWEB)

Customized reference tubes reduced sensitivity discrepancies able to be observed from one probe to the other, due to the gain setting adjustment required for a pre-definite level in amplitude response of the artificial notch. The use of a reference circuit in place of a reference part, makes characterization of the probe matched to its generator more accurate: - the material dependence is cancelled during the compensation process, - the reference signal can be adjusted more accurately in amplitude and phase response, - the manufacturing cost is reduced compared to the one necessary for machining the reference part, - the amplitude and phase response of the reference circuit can be simply modelled by using the transformer relations, such as one can appreciate the variations of the probe definition parameters and its connexion to the generator, and makes them optimal for use. The method proposed by ALSTOM for the ...

2001-07-01

236

Sequential injection system for phospholipase A2 activity evaluation: Studies on liposomes using an environment-sensitive fluorescent probe  

British Library Electronic Table of Contents (United Kingdom)

This work reports the development of an automatic methodology based on the use of 1-anilinonaphthalene-8-sulfonate (ANS) as an interfacial fluorescent probe for detecting the hydrophobic environment shift around the probe, caused by the hydrolytic action of PLA2 on the liposomes. The implementation of this reaction in a sequential injection analysis (SIA) system along with the use of the mixing chambers permitted the evaluation of PLA2 activity and assessment of the inhibitory effect of the non-steroidal anti-inflammatory drugs (NSAIDs) on PLA2 activity. Several studies were performed with the aim of establishing the appropriate flow system configuration: the liposome substrate; PLA2 and ANS optimum concentrations and incubation times before and after the enzyme addition. Based on these st...

2009-01-01

237

Probing anomalous quartic couplings in e{gamma} and {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

We analyze the potential of the e{sup +}e{sup -} linear colliders, operating in the e{gamma} and {gamma}{gamma} modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2){sub L}(circle times)U(1){sub Y} chiral operators of order p{sup 4} that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e{gamma} and {gamma}{gamma} modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10{sup -2} at 90% C.L. Moreover, the information gathered in the e{gamma} mode can be used to reduce the ambiguities of the e{sup +}e{sup -} mode.

2001-10-01

238

Probing anomalous quartic couplings in e#gamma# and #gamma##gamma# colliders  

International Nuclear Information System (INIS)

We analyze the potential of the e"+e"- linear colliders, operating in the e#gamma# and #gamma##gamma# modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2)_L(circle times)U(1)_Y chiral operators of order p"4 that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e#gamma# and #gamma##gamma# modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10"-"2 at 90% C.L. Moreover, the information gathered in the e#gamma# mode can be used to reduce the ambiguities of the e"+e"- mode.

2001-10-01

239

Microtiter plate assay for phosphate using a europium-tetracycline complex as a sensitive luminescent probe  

Energy Technology Data Exchange (ETDEWEB)

A new luminescent europium probe is presented for the determination of phosphate (P) in microtiter plate format. The assay is based on the quenching of the luminescence of the europium-tetracycline (EuTc) 1:1 complex by phosphate using a reagent concentration of 20.8 {mu}mol/L. The probe is excited at 400 nm and displays a large Stokes' shift of 210 nm. The emission maximum is located at 616 nm. The system works best at neutral pH 7 and is therefore suitable for phosphate determination in biological and biochemical systems. The linear range of the calibration plot is from 5 x 10{sup -6} mol/L to 7.5 x 10{sup -4} mol/L of phosphate, and the limit of detection is 3 {mu}mol/L.

2006-01-12

240

Extra-dimensional gravity and dijet production at {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

In this Brief Report, we consider dijet production at {gamma}{gamma} colliders as a probe of recently proposed, large extra-dimensional gravity models. The exchange of virtual, spin-2 graviton towers (Kaluza-Klein excitations) significantly modifies the cross section, as compared to the standard model predictions. We find that, in order to maximize the value of the effective scale that can be probed at a given center-of-mass energy, a very severe p{sub T} cut should be applied; in general, a p{sub T} equal to approximately 46% of the e{sup +}e{sup -} beam energy gives the highest reach. We find that we can probe the effective mass scale from about 2.7 TeV to 11.1 TeV, depending on the center-of-mass energy and assumptions about the model. (c) 2000 The American Physical Society.

2000-06-01

241

Extra-dimensional gravity and dijet production at #gamma##gamma# colliders  

International Nuclear Information System (INIS)

In this Brief Report, we consider dijet production at #gamma##gamma# colliders as a probe of recently proposed, large extra-dimensional gravity models. The exchange of virtual, spin-2 graviton towers (Kaluza-Klein excitations) significantly modifies the cross section, as compared to the standard model predictions. We find that, in order to maximize the value of the effective scale that can be probed at a given center-of-mass energy, a very severe p_T cut should be applied; in general, a p_T equal to approximately 46% of the e"+e"- beam energy gives the highest reach. We find that we can probe the effective mass scale from about 2.7 TeV to 11.1 TeV, depending on the center-of-mass energy and assumptions about the model. (c) 2000 The American Physical Society

2000-06-01

242

Eddy current probe development based on a magnetic sensor array; Developpement d'un imageur magnetique pour le controle non destructif par courants de Foucault  

Energy Technology Data Exchange (ETDEWEB)

This research deals with in the study of the use of innovating magnetic sensors in eddy current non destructive inspection. The author reports an analysis survey of magnetic sensor performances. This survey enables the selection of magnetic sensor technologies used in non destructive inspection. He presents the state-of-the-art of eddy current probes exploiting the qualities of innovating magnetic sensors, and describes the methods enabling the use of these magnetic sensors in non destructive testing. Two main applications of innovating magnetic sensors are identified: the detection of very small defects by means of magneto-resistive sensors, and the detection of deep defects by means of giant magneto-impedances. Based on the use of modelling, optimization, signal processing tools, probes are manufactured for these both applications.

2007-06-15

243

Development of In-Service Inspection system for heat transfer tubes in the primary pressurized water cooler in the HTTR  

International Nuclear Information System (INIS)

The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)

1999-08-22

244

Development of In-Service Inspection system for heat transfer tubes in the primary pressurized water cooler in the HTTR  

Energy Technology Data Exchange (ETDEWEB)

The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)

1999-08-01

245

Optical in situ size determination of single lanthanide-ion doped oxide nanoparticles  

Science.gov (United States)

We show that the size of a lanthanide-ion doped nanoparticle can be accurately determined from its luminosity. The optically determined size distribution is in very good agreement with the distribution obtained from transmission electron microscopy. These data confirm that single nanoparticles are visualized in microscopy experiments. Nanoparticles as small as 13 nm are detectable with integration times of 500 ms.

2006-12-01

246

Fractal dimension determination of sol-gel powders using transmission electron microscopy images  

Energy Technology Data Exchange (ETDEWEB)

SiO{sub 2}, TiO{sub 2} and AlO(OH) powders obtained by the sol-gel method were investigated by transmission electron microscopy. The mass-radius relation was used to determine the fractal dimensions from the images. These fractal dimensions were corrected in order to obtain the powder fractal dimensions. The results indicate a good fractal behavior and high fractal dimensions.

2004-09-15

247

Barrier filter for fluorescence microscopy of strongly autofluorescent plant tissues. Application to actin cables in Chara.  

Science.gov (United States)

A liquid barrier filter for use in fluorescence microscopy of strongly autofluorescent plant tissues is described. The filter consists of a methanol solution of cupric chloride and ferric chloride and isolates fluorescein fluorescence from the strong red autofluorescence of photosynthetic plant tissues. Subcortical actin cables in the giant alga Chara are being visualized through use of this filter together with heavy meromyosin labeling. PMID:90068

1979-05-01

248

Analysis of microstructure of materials using a combination of a focused ion beam and transmission electron microscopy  

Energy Technology Data Exchange (ETDEWEB)

Recent development in application of a focused ion beam (FIB) technique to preparation of thin foil specimens for transmission electron microscopy (TEM) observation has been reviewed. Combined technique of FIB/TEM enables one to analyze those microstructures which have been almost impossible or very difficult to analyze so far. (author)

2002-03-01

249

Analysis of active site distribution in ZSM-5 crystals by infrared microscopy  

Science.gov (United States)

The acid site distribution over large ZSM-5 crystals was analyzed using FTIR microscopy. Results of the analysis of the OH-stretching vibrations and of vibrations of pyridine adsorbed on Bronsted and Lewis acid sites were found to be in good agreement. The resolution which can be obtained using this novel technique is about 10-20 [mu]m. This limits the application to large crystals as analyzed in this study. Comparison of the results of IR microscopy with aluminum distributions obtained by electron microprobe analysis revealed that IR microscopy cannot resolve inhomogeneities on a scale smaller than the above-state limits. The results of both methods on a larger scale, however, are in very good agreement. Using a combination of both techniques, it is possible to obtain a clearer picture of the distribution of acid sites in large zeolite crystals, where electron microprobing gives the higher resolution, and IR ...

1993-10-01

250

Validating eddy current array probes for inspecting steam generator tubes  

International Nuclear Information System (INIS)

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for calculating POD curves ...

1997-11-16

251

Validating eddy current array probes for inspecting steam generator tubes  

Energy Technology Data Exchange (ETDEWEB)

A CANDU nuclear reactor was shut down for over one year because steam generator (SG) tubes had failed with outer diameter stress-corrosion cracking (ODSCC) in the U-bend section. Novel, single-pass eddy current transmit-receive probes, denoted as C3, were successful in detecting all significant cracks so that the cracked tubes could be plugged and the unit restarted. Significant numbers of tubes with SCC were removed from a SG in order to validate the results of the new probe. Results from metallurgical examinations were used to obtain probability-of-detection (POD) and sizing accuracy plots to quantify the performance of this new inspection technique. Though effective, the above approach of relying on tubes removed from a reactor is expensive, in terms of both economic and radiation-exposure costs. This led to a search for more affordable methods to validate inspection techniques and procedures. Methods are presented for calculating POD curves ...

1997-07-01

252

The efflux of a fluorescent probe is catalyzed by an ATP-driven extrusion system in Lactococcus lactis.  

UK PubMed Central (United Kingdom)

Many bacteria, both gram positive and gram negative, extrude in an energy-dependent manner the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5[and -6]-carboxyfluorescein (BCECF) (D. Molenaar,...Full Text Available

1992-05-01

253

The direct comparison of health and ulcerated stomach tissue: A multiple probe microdialysis sampling approach  

UK PubMed Central (United Kingdom)

The ability to directly compare gastric ulcerated and healthy tissue would aid in the understanding of the physiological differences between these tissue types. Presently, these comparisons...Full Text Available

2008-09-10

254

Strategies for the uses of lanthanide NMR shift probes in the determination of protein structure in solutio. Application to the EF calcium binding site of carp parvalbumin.  

UK PubMed Central (United Kingdom)

The homologous sequences observed for many calcium binding proteins such as parvalbumin, troponin C, the myosin light chains, and calmodulin has lead to the hypothesis that these proteins have homologous...Full Text Available

1980-10-01

255

Rapid technique of DNA-DNA in situ hybridisation on formalin fixed tissue sections using microwave irradiation.  

UK PubMed Central (United Kingdom)

The relative sensitivities of different protocols for detecting cytomegalovirus nucleic acid sequences in histological specimens, using a biotinylated cDNA probe, were assessed. Several commonly used...Full Text Available

1987-08-01

257

Probing the structural hierarchy and energy landscape of an RNA T-loop hairpin  

UK PubMed Central (United Kingdom)

The T-loop motif is an important recurrent RNA structural building block consisting of a U-turn sub-motif and a UA trans Watson–Crick/Hoogsteen base pair. In the presence of...Full Text Available

2007-11-01

258

Probing the Mechanisms of an Air Amplifier using a LTQ-FT-ICR-MS and Fluorescence Spectroscopy  

UK PubMed Central (United Kingdom)

We report the first quantitative assessment of electrosprayed droplet/ion focusing enabled by the use of a voltage-assisted air amplifier between an electrospray ionization emitter and a hybrid...Full Text Available

2007-11-01

259

Probing active galactic nuclei with H2O megamasers.  

UK PubMed Central (United Kingdom)

We describe the characteristics of the rapidly rotating molecular disk in the nucleus of the mildly active galaxy NGC4258. The morphology and kinematics of the disk are delineated by the point-like...Full Text Available

1995-12-05

260

Probing a Membrane Matrix Regulating Hormone Action  

UK PubMed Central (United Kingdom)

Auxin-induced pea (Pisum sativum) stem section elongation is enhanced at levels of 3 to 40 micromolar by six new classes of alkane derivatives additional to those described earlier,...Full Text Available

1971-11-01

261

Probing Compulsive and Impulsive Behaviors, from Animal Models to Endophenotypes: A Narrative Review  

UK PubMed Central (United Kingdom)

Failures in cortical control of fronto-striatal neural circuits may underpin impulsive and compulsive acts. In this narrative review, we explore these behaviors from the perspective of neural processes...Full Text Available

2010-02-01

262

Pressure Probe Technique for Measuring Water Relations of Cells in Higher Plants 1  

UK PubMed Central (United Kingdom)

A new method is described for continuously measuring cell turgor pressure (P), hydraulic conductivity (Lp), and volumetric elastic modulus (ε) in higher plant cells, using a pressure...Full Text Available

1978-02-01

263

Osmotically Induced Removal of Water from Fungal Cells as Determined by a Spin Probe Technique 1  

UK PubMed Central (United Kingdom)

Effects of physical environment on plasma membrane semipermeability and osmotic induction of changes in aqueous cytoplasmic volume were studied in vegetative and spore cells of a plant pathogenic fungus,...Full Text Available

1978-11-01

264

New Biomarkers Probing Depth of Cell Senescence Assessed by Laser Scanning Cytometry  

UK PubMed Central (United Kingdom)

The imaging analytical capabilities of laser scanning cytometer (LSC) have been used to assess morphological features considered to be typical of the senescent phenotype. The characteristic “flattening”...Full Text Available

2010-11-01

265

Near Infrared Dyes as Lifetime Solvatochromic Probes for Micropolarity Measurements of Biological Systems  

UK PubMed Central (United Kingdom)

The polarity of biological mediums controls a host of physiological processes such as digestion, signaling, transportation, metabolism, and excretion. With the recent widespread use of near-infrared...Full Text Available

2007-10-15

266

Multiple-element eddy current probes for enhanced inspection  

Energy Technology Data Exchange (ETDEWEB)

Eddy current inspection methods are widely used for the nondestructive evaluation (NDE) of tubular products. Specifically, the sensors and instrumentation are designed to detect and characterize changes in a material's electrical and magnetic properties produced by the presence of discontinuities. A recent major enhancement in eddy current inspection technology has been the development of computer interfacing for data collection, analysis, and display. This breakthrough has led to multiple-frequency testing, eddy current imaging, and automated data interpretation systems that significantly enhance both capabilities and reliability of the eddy current inspection. In addition to the clear advantages in data processing, computer interfacing also permits the design and creation of unique sensors that further enhance eddy current inspection capabilities. Perhaps the most promising area of computer interactive probe design is multiple element sensors. ...

1993-07-01

267

Mercury modeling for PWSCC length sizing. [Primary water stress corrosion cracking  

Science.gov (United States)

This report describes the results of EPRI Program S404-28, titled Experimental Modeling of Eddy Current Response'', conducted by the Westinghouse Science and Technology Center (STC). The Westinghouse STC demonstrates that its mercury modeling technique provides an unique bridge between steam generator eddy current field inspection conditions and predictions obtained using recently developed analytical models. The mercury modeling technique was used systematically to explore factors which contribute to primary water stress corrosion cracking (PWSCC) sizing inaccuracy, including probe design, coil excitation frequency, crack length, and crack morphology. Two new proposed techniques for inverting crack lengths from eddy current data are compared with the technique commonly used in field data analysis for PWSCC. The performance of uniform field eddy current probes is compared with the performance of pancake coil ...

1992-08-01

268

Mercury modeling for PWSCC length sizing. [Primary water stress corrosion cracking  

Energy Technology Data Exchange (ETDEWEB)

This report describes the results of EPRI Program S404-28, titled Experimental Modeling of Eddy Current Response'', conducted by the Westinghouse Science and Technology Center (STC). The Westinghouse STC demonstrates that its mercury modeling technique provides an unique bridge between steam generator eddy current field inspection conditions and predictions obtained using recently developed analytical models. The mercury modeling technique was used systematically to explore factors which contribute to primary water stress corrosion cracking (PWSCC) sizing inaccuracy, including probe design, coil excitation frequency, crack length, and crack morphology. Two new proposed techniques for inverting crack lengths from eddy current data are compared with the technique commonly used in field data analysis for PWSCC. The performance of uniform field eddy current probes is compared with the performance of pancake coil ...

1992-08-01

269

Localization of gold in synovial membrane of rheumatoid arthritis treated with sodium aurothiomalate. Studies by electron microscope and electron probe x-ray microanalysis.  

UK PubMed Central (United Kingdom)

The localization of gold in the synovial membrane of rheumatoid arthritis patients treated with sodium aurothiomalate was examined and quantitative analysis of epon-embedded sections was carried out...Full Text Available

1977-06-01

270

Ion clustering in aqueous solutions probed with vibrational energy transfer  

UK PubMed Central (United Kingdom)

Despite prolonged scientific efforts to unravel the hydration structures of ions in water, many open questions remain, in particular concerning the existences and structures of ion clusters in 1∶1...Full Text Available

2011-03-22

271

Investigation of the hadronic final state in electron-proton interactions at HERA  

Energy Technology Data Exchange (ETDEWEB)

The main subject of this thesis is the study of the hardronic final state in deep-inelastic electron-proton scattering. Theexperiment described in this thesis is performed with such a high resolution that the substructure of the proton is probed by the electron beam with a resolution of less than 10{sup -15} cm. (orig./HSI).

1995-09-18

272

Inspection of PFR steam generators  

International Nuclear Information System (INIS)

The inspection of PFR evaporator tubing, superheater and reheater tubing, and tube plate examinations, are described. Ferritic steel U tubes in the evaporator have been examined by an eddy current system operating at 400 kHz using flexible rotating probes. Surface defects as shallow as 0.1 mm can be detected and sized in the range 0.1 to 0.5 mm deep. An ultrasonic method is under development for wall thickness. Special test coil probes have been developed for examination of the type 316 stainless steel superheater and reheater tubing. Crack-life defects in the bore are detectable at approximately 10% wall thickness and 20% on the outside diameter. Tube plate examinations from the tube holes, have been conducted using eddy current probes which identify surface breaking cracks in the holes. For detecting curtain cracks between tube plate holes, ultrasonic compression wave probes have been used. (U.K.).

1976-03-09

273

In-Space Propulsion Program Advanced Sensor Project - NASA  

Science.gov (United States)

Aug 25, 2004 ... Current Developments in Future Planetary Probe Sensors: .... Data: Outgoing and incoming EIA RS-422 interface for serial data transmission (for electrical purposes only, .... Milos, et. al, Journal of Spacecraft & Rockets 1999 ...

274

In-Situ Atr Ftir Probe Investigation of Selective Organic Synthetic Routes Using Nanoscale Crystal Reactors  

Environmental Research Database

ObjectivesThe overall aim of this work is to use an in-situ FTIR probe to investigate selected heterogeneous catalysts in industrially relevant organic reactions. This approach will be broadly applicable to the UK fine chemical manufacturing base.~%~~%~The project has the following specific objectives:~%~~%~- To demonstrate and develop the use of an in-situ FTIR probe in a batch reactor at elevated temperatures (eg greater than 100 deg C) to monitor reactant usage and product formation.~%~~%~- To validat [continued...]DescriptionThis proposal concerns the in-situ study of catalytic processes and reaction kinetics. The catalysts concerned are microporous materials, such as, zeolites, containing pores and cavities of molecular dimensions. These catalysts constitute crystal reactors on a nanometer scale that are selective on a size and shape basis for organic molecules used in this ...

2003-01-31

275

In service inspection for steam generator tubes  

International Nuclear Information System (INIS)

In this paper the authors show the means putting in place for examination of steam generators tubes. These means (eddy current probes, ultrasonic testing) associated with a knowledge on degradation phenomena allow mapping controlled tubes and limiting undesirable obturations.

1987-11-24

276

Functional pools of oxidative and glycolytic fibers in human muscle observed by 31P magnetic resonance spectroscopy during exercise.  

UK PubMed Central (United Kingdom)

Quantitative probing of heterogeneous regions in muscle is feasible with phosphorus-31 magnetic resonance spectroscopy because of the differentiation of metabolic patterns of glycolytic and oxidative...Full Text Available

1987-12-01

277

Fluorine-19 NMR Chemical Shift Probes Molecular Binding to Lipid Membranes  

UK PubMed Central (United Kingdom)

The binding of amphiphilic molecules to lipid bilayers is followed by 19F NMR using chemical shift and line shape differences between the solution and membrane-tethered states of...Full Text Available

2008-05-22

278

Five-Year Wilkinson Microwave Anisotropy Probe (WMAP1 - LAMBDA - NASA  

Science.gov (United States)

If we decompose C1 using SVD the parameter covariance matrix can be inverted to ... However, we can analyze the parameter covariance matrix directly by ...

279

Fatigue crack detection in aircraft skin structures using eddy current array technique  

International Nuclear Information System (INIS)

Detection of fatigue damage cracks in aircraft skin structures is an ongoing NDT challenge. Cracks growing rate is difficult to predict, and for this reason, it is important to detect them as soon as possible to avoid a catastrophic break. Eddy current methods are known and well-accepted techniques which are relatively simple to carry out. However, with conventional inspection of airframe structures using standard driver-pickup eddy current probes, it is difficult to detect small fatigue cracks initiated in the second layer of the skin and in the shadow region at fastener holes. Such difficulty is related to fasteners length and their spacing which reduces test sensitivity. This report explains the development of improved eddy current probe/technique to detect and visualize fatigue cracks in fasteners. In this study, an eddy current array probe was evaluated and new coil design was suggested. Several tests were conducted on ...

2004-01-01

280

Evaluation of 13C isotopic tracers for metabolic flux analysis in mammalian cells  

UK PubMed Central (United Kingdom)

13C metabolic flux analysis (MFA) is the most comprehensive means of characterizing cellular metabolic states. Uniquely labeled isotopic tracers enable more focused analyses to probe...Full Text Available

2009-11-01

281

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 evaluated primarily for ...

2009-07-01

282

Dissociation dynamics of methylal  

Energy Technology Data Exchange (ETDEWEB)

The dissociation of methylal is investigated using mass spectrometry, combined with a pyrolytic radical source and femtosecond pump probe experiments. Based on preliminary results two reaction paths of methylal dissociation are proposed and discussed. (author) 4 fig., 3 refs.

1999-08-01

283

Development of compression-controlled low-level laser probe system: towards clinical application  

UK PubMed Central (United Kingdom)

Various physico-chemical tissue optical clearing (TOC) methods have been suggested to maximize photon density in tissue. In order to enhance photon density, a compression-controlled low-level...Full Text Available

2010-09-01

284

Detecting variants with Metabolic Design, a new software tool to design probes for explorative functional DNA microarray development  

UK PubMed Central (United Kingdom)

BackgroundMicroorganisms display vast diversity, and each one has its own set of genes, cell components and metabolic reactions. To assess their huge unexploited metabolic potential...Full Text Available

285

Design of 240,000 orthogonal 25mer DNA barcode probes  

UK PubMed Central (United Kingdom)

DNA barcodes linked to genetic features greatly facilitate screening these features in pooled formats using microarray hybridization, and new tools are needed to design large sets of barcodes to allow...Full Text Available

2009-02-17

286

Design and Construction of a Versatile Dual Volume Heteronuclear Double Resonance Microcoil NMR Probe  

UK PubMed Central (United Kingdom)

Improved NMR detection of mass limited samples can be obtained by taking advantage of the mass sensitivity of microcoil NMR, while throughput issues can be addressed using multiple, parallel...Full Text Available

2009-04-01

287

Comparative analysis of nitrifying bacteria associated with freshwater and marine aquaria.  

UK PubMed Central (United Kingdom)

Three nucleic acid probes, two for autotrophic ammonia-oxidizing bacteria of the beta subdivision of the class Proteobacteria and one for alpha subdivision nitrite-oxidizing bacteria, were developed...Full Text Available

1996-08-01

288

Biotin-labeled hairpin oligonucleotides: probes to detect double-strand breaks in DNA in apoptotic cells.  

UK PubMed Central (United Kingdom)

Hairpin oligonucleotides were synthesized with stems ending in a double-stranded structure, which can be ligated to double-strand breaks in DNA, and with loops that contain nucleotides modified by the...Full Text Available

1998-04-01

289

Application of automatic inspection system to nondestructive test of heat transfer tubes of primary pressurized water cooler in the high temperature engineering test reactor. Joint research  

International Nuclear Information System (INIS)

Heat transfer tubes of a primary pressurized water cooled (PPWC) in the high temperature engineering test reactor (HTTR) form the reactor pressure boundary of the primary coolant, therefore are important from the viewpoint of safety. To establish inspection techniques for the heat transfer tubes of the PPWC, an automatic inspection system was developed. The system employs a bobbin coil probe, a rotating probe for eddy current testing (ECT) and a rotating probe for ultrasonic testing (UT). Nondestructive test of a half of the heat transfer tubes of the PPWC was carried out by the automatic inspection system during reactor shutdown period of the HTTR (about 55% in the maximum reactor power in this paper). The nondestructive test results showed that the maximum signal-to-noise ratio was 1.8 in ECT. Pattern and phase of Lissajous wave, which were obtained for the heat transfer tube of the PPWC, were different from those ...

290

An investigation of the distribution of resistivity in single crystal germanium ribbon by the single probe method  

CERN Document Server

Experimental data are reported on the micro-irregularities of resistivity in longitudinal and transverse specimens of germanium 0.5 to 0.8 mm in thickness and 25 to 40 mm in width. These data are correlated with the conditions of growth of the crystals. (16 refs).

1972-01-01

291

AeroSpace Information for a Changing World - NASA Technical ...  

Science.gov (United States)

Probing Neutron Star Evolution with Gamma Rays Online Source: Click to View PDF File [PDF Size: 217 KB] Author: Wijers, Ralph A. M. J. ...

292

A novel fluorescent pH probe for expression in plants  

UK PubMed Central (United Kingdom)

BackgroundThe pH is an important parameter controlling many metabolic and signalling pathways in living cells. Recombinant fluorescent pH indicators (pHluorins) have come into vogue...Full Text Available

293

A Meta-Analysis of Animal Studies on Disruption of Spatial Navigation by Prenatal Cocaine Exposure  

UK PubMed Central (United Kingdom)

Water-maze testing has been used to assess prenatal cocaine (PCOC)- induced deficits in behavioral studies of spatial navigation and memory abilities. Effects of PCOC in acquisition or in probe...Full Text Available

2007-01-01

294

Wilson loops in warped resolved deformed conifolds  

CERN Document Server

We calculate quark-antiquark potentials using the relationship between the expectation value of the Wilson loop and the action of a probe string in the string dual. We review and categorize the possible forms of the dependence of the energy on the separation between the quarks. In particular, we examine the possibility of there being a minimum separation for probe strings which do not penetrate close to the origin of the bulk space, and derive a condition which determines whether this is the case. We then apply these considerations to the flavoured resolved deformed conifold background of Gaillard et al. We suggest that the unusual behaviour we observe in this solution is likely to be related to the IR singularity which is not present in the unflavoured case.

2011-01-01

295

Use of Eu/sup 3 +/ as an oxygen environment probe in alkali-alkaline earth-lanthanide phosphates with the. beta. -K/sub 2/SO/sub 4/ structure  

Energy Technology Data Exchange (ETDEWEB)

The use of europium as a local structural probe allows the various phases appearing in the NaCaPO/sub 4/-Na/sub 3/Eu(PO/sub 4/)/sub 2/ and NaSrPO/sub 4/-Na/sub 3/Eu(PO/sub 4/)/sub 2/ systems to be detected. The broadening of the europium emission lines in going from the calcium to the strontium phases illustrates the ease of displacement of the PO/sub 4/ groups.

1983-09-15

296

The enteral probe nutrition with Cosilat in complex therapy of patients with radiotherapeutic late effects of the colon  

International Nuclear Information System (INIS)

Results are presented applying an enteral nutrition by means of probes with Cosilat in complex therapy of patients with radiotherapeutic late effects of the colon. This nutrition was prescribed with the intention to gave the colon a functional recovery and to guarantee optimal conditions for repair of radiation injuries. Good results were seen in 27 of 28 patients (96.7%), the situation of one patient (3.3%) continued without any change. Cosilat has a high nutritive value, good organoleptic qualities and is well digested without any complications. (author).

297

Principal geological results of petroleum and gas prospecting on Southern Sakhalin  

Energy Technology Data Exchange (ETDEWEB)

Results are given for deep-level petroleum and gas drilling probes in various coastal zones of Southern Sakhalin covering the Poronai depression and the Aniv Bay trough. The exploratory probes indicate that the Middle Miocence deposits of the Boundary trough contain commercial-size deposits of petroleum, that commercial-size gas deposits are in the upper Myocene deposits of the Aliv Bay trough, and that the upper Cretaceous and Cenozoic deposits of the eastern section of Southern Sakhalin lack folded deformations. 7 references, 2 figures.

1981-01-01

298

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-08-01

299

Local secondary-electron emission spectra of graphite and gold surfaces obtained using the Scanning Probe Energy Loss Spectrometer (SPELS)  

International Nuclear Information System (INIS)

Secondary-electron emission (SEE) spectra have been obtained with the Scanning Probe Energy Loss Spectrometer at a tip-sample distance of only 50 nm. Such short working distances are required for the best theoretical spatial resolution (<10 nm). The SEE spectra of graphite, obtained as a function of tip bias voltage, are shown to correspond to unoccupied states in the electronic band structure. The SEE spectra of thin gold films demonstrate the capability of identifying (carbonaceous) surface contamination with this technique.

2009-11-25

300

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

CERN Document Server

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

2007-01-01

301

Detection of EDM defects under Monju support plate using experimental data from remote field eddy current probes and a multi-frequency algorithm  

International Nuclear Information System (INIS)

This paper describes detection of electro-discharged machine (EDM) defects in magnetic steam generator (SG) tubes of Monju fast breeder reactor (FBR). The EDM defects are located under support plate (SP), on the outer tube surface and they are detected by a remote field eddy current probe. Using the experimental measurements and a multi frequency algorithm, the defect signal can be extracted from the SP signal. The parameters of the multi-frequency algorithm were calculated by comparing SP measurements with two-dimensional finite element simulations (FEM). (author)

2006-07-01

302

APSIS - an Artificial Planetary System in Space to probe extra-dimensional gravity and MOND  

CERN Document Server

A proposal is made to test Newton's inverse-square law using the perihelion shift of test masses (planets) in free fall within a spacecraft located at the Earth-Sun L2 point. Such an Artificial Planetary System In Space (APSIS) will operate in a drag-free environment with controlled experimental conditions and minimal interference from terrestrial sources of contamination. We demonstrate that such a space experiment can probe the presence of a "hidden" fifth dimension on the scale of a micron, if the perihelion shift of a "planet" can be measured to sub-arc-second accuracy. Some suggestions for spacecraft design are made.

2006-01-01

303

A truly commercial product  

International Nuclear Information System (INIS)

In one of the first uses of high Tc superconductors in an end-use product, Lake Shore Cryotronics and a Swiss lab have developed a liquid nitrogen level sensor using a high Tc thin film. The probe is manufactured using a seamless stainless steel tube with an yttrium-based zirconium oxide flame-sprayed on the tube. A plasma-sprayed superconductor compound is deposited on top of that. The probe is coated with a sealant that protects the superconducting film from the atmosphere. This manufacturing method has yielded an extremely durable product. Unaffected by ice formation and related mechanical problems, the superconducting level sensor can be kept in the dewar for long periods of time.

304

$B \\to X_{s} \\gamma$ and $B \\to X_{s} l^{+} l^{-}$ decays at LHCb  

CERN Document Server

\\lhcb is one of the four major experiments at the Large Hadron Collider (\\lhc) at CERN. It is custom built to look for CP violation and New Physics in rare decays of heavy flavour hadrons, like the B and D systems. Rare decays that occur via loop diagrams provide a way to probe New Physics at energy scales much higher than can be probed by direct production in experiments. In this article, the \\lhcb prospects for such measurements with exclusive decays of the type $B \\to \\Xs \\gamma$ and $B \\to X_{s} l^{+} l^{-}$ are presented.

2011-01-01

305

$B \\to X_s\\gamma$ and $B\\to X_sl^+l^-$ decays at LHCb  

CERN Document Server

LHC$b$ is one the four major experiments at the Large Hadron Collider (LHC) at CERN. It is custom built to look for CP violation and New Physics in rare decays of heavy flavor hadrons, like the B and D systems. Rare decays that occur via loop diagrams provide a way to probe New Physics at energy scales much higher than can be probed by direct production in experiment. In this article, the LHC$b$ prospects for such measurement with exclusive decays of the type $B \\to X_s\\gamma$ and $B\\to X_sl^+l^-$ are presented.

2011-01-01

306

Visualization and Analysis of Eddy Current Data from D-Probe  

Energy Technology Data Exchange (ETDEWEB)

Eddy current testing (ECT) method is widely used as the non-destructive evaluation (NDE) of the various kinds of material degradation occurring in nuclear power plants (NPPs) components including steam generator (SG) tubes. Detection of any defects or flaws in the steam generator tubes in the early stage is very important in maintenance of NPP for its primary role as the pressure boundary with thin wall thickness. Although the ECT technique provides lots of information for a SG management, it has a generic problem in its reliability due to a low ability in detect of small defects and some difficulty in a signal analysis. For the improvement of these shortcomings in conventional ECT, profile-MRPC (motorized rotating pancake coil) ECT technology was developed in KAERI. The key of this new technology is the development of new eddy current probes, designated as a diagnostic probe (D-probe). The D-probe is ...

2009-05-15

307

Visualization and Analysis of Eddy Current Data from D-Probe  

International Nuclear Information System (INIS)

Eddy current testing (ECT) method is widely used as the non-destructive evaluation (NDE) of the various kinds of material degradation occurring in nuclear power plants (NPPs) components including steam generator (SG) tubes. Detection of any defects or flaws in the steam generator tubes in the early stage is very important in maintenance of NPP for its primary role as the pressure boundary with thin wall thickness. Although the ECT technique provides lots of information for a SG management, it has a generic problem in its reliability due to a low ability in detect of small defects and some difficulty in a signal analysis. For the improvement of these shortcomings in conventional ECT, profile-MRPC (motorized rotating pancake coil) ECT technology was developed in KAERI. The key of this new technology is the development of new eddy current probes, designated as a diagnostic probe (D-probe). The D-probe is ...

2009-05-01

308

Synopsis of moisture monitoring by neutron probe in the unsaturated zone at Area G  

Energy Technology Data Exchange (ETDEWEB)

Moisture profiles from neutron probe data provide valuable information in site characterization and to supplement ground water monitoring efforts. The neutron probe precision error (reproducibility) is found to be about 0.2 vol% under in situ field conditions where the slope in moisture content with depth is varying slowly. This error is about 2 times larger near moisture spikes (e.g., at the vapor phase notch), due to the sensitivity of the probe response to vertical position errors on the order of 0.5 inches. Calibrations were performed to correct the downhole probe response to the volumetric moisture content determined on core samples. Calibration is sensitive to borehole diameter and casing type, requiring 3 separate calibration relations for the boreholes surveyed here. Power law fits were used for calibration in this study to assure moisture content results greater than zero. Findings in the ...

1997-12-31

309

Edge biasing in the WEGA stellarator  

Energy Technology Data Exchange (ETDEWEB)

The WEGA stellarator is used to confine low temperature, overdense (densities exceeding the cut-off density of the heating wave) plasmas by magnetic fields in the range of B=50-500 mT. Microwave heating systems are used to ignite gas discharges using hydrogen, helium, neon or argon as working gases. The produced plasmas have been analyzed using Langmuir and emissive probes, a single-channel interferometer and ultra-high resolution Doppler spectroscopy. For a typical argon discharge in the low field operation, B=56 mT, the maximum electron density is n{sub e}{proportional_to}10{sup 18} m{sup -3} with temperatures in the range of T=4-12 eV. The plasma parameters are determined by using Langmuir probes and are cross-checked with interferometry. It is demonstrated within this work that the joint use of emissive probes and ultra-high resolution Doppler spectroscopy allows a precise measurement of the radial electric field. The ...

2009-02-27

310

Status of non-electric nuclear heat applications: Technology and safety  

International Nuclear Information System (INIS)

Nuclear energy plays an important role in electricity generation, producing 16% of the world's electricity at the beginning of 1999. It has proven to be safe, reliable, economical and has only a minimal impact on the environment. Most of the world's energy consumption, however, is in the form of heat. The market potential for nuclear heat was recognized early. Some of the first reactors were used for heat supply, e.g. Calder Hall (United Kingdom), Obninsk (Russian Federation), and Agesta (Sweden). Now, over 60 reactors are supplying heat for district heating, industrial processes and seawater desalination. But the nuclear option could be better deployed if it would provide a larger share of the heat market. In particular, seawater desalination using nuclear heat is of increasing interest to some IAEA Member States. In consideration of the growing experience being accumulated, the IAEA periodically reviews the progress and new developments in the field of nuclear ...

311

Reflection-Free One-Way Edge Modes in a Gyromagnetic Photonic Crystal  

CERN Document Server

We point out that electromagnetic one-way edge modes analogous to quantum Hall edge states, originally predicted by Raghu and Haldane in 2D gyroelectric photonic crystals possessing Dirac point-derived bandgaps, can appear in more general settings. In particular, we show that the TM modes in a gyromagnetic photonic crystal can be formally mapped to electronic wavefunctions in a periodic electromagnetic field, so that the only requirement for the existence of one-way edge modes is that the Chern number for all bands below a gap is non-zero. In a square-lattice gyromagnetic Yttrium-Iron-Garnet photonic crystal operating at microwave frequencies, which lacks Dirac points, time-reversal breaking is strong enough that the effect should be easily observable. For realistic material parameters, the edge modes occupy a 10% band gap. Numerical simulations of a one-way waveguide incorporating this crystal show 100% transmission across strong defects, such as perfect ...

2007-01-01

312

Mechanical properties and texture evolution of AZ31 Mg alloy during equal channel angular pressing  

Energy Technology Data Exchange (ETDEWEB)

Microstructure and texture evolution in the AZ31 Mg alloy subject to equal channel angular pressing (ECAP) have been investigated and correlated with the mechanical properties. When AZ31 Mg alloy was ECAPed up to 8 passes following the route B{sub c}, grain refinement occurred effectively. Texture was also changed during ECAP. The original fiber texture of the extruded AZ31 Mg alloy changed to a new texture component of (01 anti 11)[5 anti 2 anti 3 anti 1], and the texture of (01 anti 11)[5 anti 2 anti 3 anti 1] orientation was rotated to (13 anti 46)[7 anti 5 anti 20] orientation after 6-pass ECAP process. The variation of the strength with the pass number was explained by the texture and grain size. The strength data of AZ31 Mg alloys followed the standard Hall-Petch relationship when the similar texture was retained during the ECAP process. Otherwise the effect of texture on strength was dominant over the strengthening due to grain refinement. (orig.)

2005-07-01

313

Fabrication, structure and consolidation of NiAl-Al_2O_3 mechanically alloyed nanocomposite powders  

International Nuclear Information System (INIS)

Reactive milling of NiO + Al powder mixture resulted in the formation of NiAl-Al_2O_3 nanocomposite powders, with a crystallite size of about 20 nm. The Hall-Williamson analysis revealed that NiAl showed an orientation dependent crystallite size after short processing time and orientation dependent internal strain after long milling time. Both anisotropies were removed by heating the powders in the differential scanning calorimetry. Calorimetric studies showed one exothermic effect attributed to the reduction reaction of NiO and endothermic one associated with melting of Al. Two methods were applied for powders compaction: resistance sintering and pulse electric discharge. In both cases the densities of abut 90% of the theoretical value were achieved. A significant increase in average NiAl crystallites size in compacted samples was observed, up to several hundreds of nanometers.(author)

2001-09-23

314

Effects of Intensity and Position Modulation On Switched Electrode Electronics Beam Position Monitor Systems at Jefferson Lab  

Energy Technology Data Exchange (ETDEWEB)

Two types of switched electrode electronics beam position monitors are in use at Jefferson Lab. Together they provide accurate beam position to the control system for beam intensities between 50 nA and 2 mA. One version, called the linac style, has a switching frequency of 125 kHz. The other, called the transport type, has a switching frequency of 7 kHz. The basic system provides information to the control system at a 1 Hz update rate. The systems are regularly used to measure the AC component of beam position and energy as well as suppress this motion as part of a fast feedback system. Position data produced by the system are also acquired on an event by event basis as part of the nuclear physics program in two of the experimental halls. This paper will focus on the AC characteristics of the system. These characteristics are affected by analog filter frequencies and a time delay between the measurement of the positive electrode signal and the negative electrode ...

2000-05-01

315

Drying characteristics and nitrogen loss of biogas digestate during drying process  

Energy Technology Data Exchange (ETDEWEB)

The cost of transporting biogas digestate can be decreased by reducing its water content. However, the digestate emits volatile compounds during drying. This study investigated the drying behaviour and the change of digestate composition. Drying took place in a hybrid solar/waste-heat dryer that used solar energy as well as waste heat from a combined heat and power unit (CHP) and the exhaust air of a microturbine. The experiment involved the use of 60 t of liquid digestate. Climatic conditions were measured inside and outside the drying hall. Dry matter (DM) and organic dry matter (ODM) were also measured on a daily basis. In addition, the energy consumption of waste and solar heat were recorded and related to the quantity of dried feedstock. The total nitrogen, ammonium, phosphate, potassium oxide, magnesium oxide and calcium oxide in the digestate were subjected to chemical analysis before and after the drying process. Losses of nitrogen were calculated. Specific ...

2010-07-01

316

Advanced Neutron Source: Plant Design Requirements. Revision 4  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this PDR document and the set of SDD documents will define and ...

1990-07-01

317

A new visitor centre for CMS  

CERN Multimedia

At the inauguration of the new CMS visitor centre. The CMS experiment inaugurated a new visitor centre at its Cessy site on 14 June. This will allow the thousands of people who come to CERN each year to follow the construction of one the Laboratory's flagship experiments first-hand. CERN receives over 20,000 visitors each year. Until recently, many of them were taken on a guided tour of one of the LEP experiments. With the closure of LEP, however, trips underground are no longer possible, and the Visits' Service has put in place a number of other itineraries (Bulletin 46/2000). Since the CMS detector will be almost entirely constructed in a surface hall, it is now taking a big share of the limelight. The CMS visitor centre has been built on a platform overlooking CMS construction. It contains a set of clear descriptive posters describing the experiment, along with a video projection showing animations and movies about CMS construction. In the coming weeks, a ...

2001-01-01

318

A Precision Measurement of the Neutrino Mixing Angle theta_13 using Reactor Antineutrinos at Daya Bay  

CERN Document Server

A reactor-neutrino experiment, Daya Bay, has been proposed to determine the least-known neutrino mixing angle theta_13 using electron antineutrinos produced at the Daya Bay nuclear power complex in China. Daya Bay is an international collaboration with institutions from China, the United States, the Czech Republic, Hong Kong, Russia, and Taiwan. The experiment will use eight identical detectors deployed at three different locations optimized for monitoring the antineutrino rates from the six reactors and for detecting any rate deficit and spectral distortion near the first oscillation maximum. The overburden of the under ground experimental halls, connected with tunnels, ranges from about 250 to 900 meters-water-equivalent so that the cosmogenic background is small compared to the number of observed antineutrino events. Civil construction of tunnels and experimental facilities is planned to start in 2007, with detector construction beginning in 2008. The experiment ...

2007-01-01

319

Development of a method for xenon determination in the microstructure of high burn-up nuclear fuel[Dissertation 17527  

Energy Technology Data Exchange (ETDEWEB)

In nuclear fuel, in approximately one quarter of the fissions, one of the two formed fission products is gaseous. These are mainly the noble gases xenon and krypton with isotopes of xenon contributing up to 90% of the product gases. These noble fission gases do not combine with other species, and have a low solubility in the normally used uranium oxide matrix. They can be dissolved in the fuel matrix or precipitate in nanometer-sized bubbles within the fuel grain, in micrometer-sized bubbles at the grain boundaries, and a fraction also precipitates in fuel pores, coming from fuel fabrication. A fraction of the gas can also be released into the plenum of the fuel rod. With increasing fission, and therefore burn-up, the ceramic fuel material experiences a transformation of its structure in the 'cooler' rim region of the fuel. A subdivision occurs of the original fuel grains of few microns size into thousands of small grains of sub-micron sizes. Additionally, larger ...

2008-07-01

320

X-ray Phase Imaging Microscopy using a Fresnel Zone Plate and a Transmission Grating  

International Nuclear Information System (INIS)

We report on a hard X-ray phase imaging microscopy (a phase-difference microscopy) that consists of an objective and a transmission grating. The simple optical system provides a quantitative phase image, and does not need a wave field mostly coherent on the objective. Our method has a spatial resolution almost same as that of the absorption contrast microscope image obtained by removing the grating. We demonstrate how our approach provides a phase image from experimentally obtained images. Our approach is attractive for easily appending a quantitative phase-sensitive mode to normal X-ray microscopes, and has potentially broad applications in biology and material sciences.

2010-06-23

321

Vessel elements present in the secondary xylem of Trochodendron and Tetracentron (Trochodendraceae)  

British Library Electronic Table of Contents (United Kingdom)

For almost 150 years, the two monotypic genera Trochodendron and Tetracentron (Trochodendraceae) have been considered to share an unusual and primitive feature in angiosperms - the lack of vessels in their wood. Therefore, they have been classified in a basal position in the angiosperms. Our observations by light microscopy, low-vacuum environmental scanning electron microscopy (ESEM) and high-vacuum scanning electron microscopy (SEM) both in fresh and FAA-fixed materials consistently showed the presence of tracheary elements differentiated into two types in both genera. In Trochodendron, the tracheary elements can be divided into perforate vessel elements and imperforate fiber-tracheids and tracheids. The vessel elements show end and lateral walls. The pits on the end walls are elongate- ...

2011-01-01

322

The surface topography of the choroid plexus. Environmental, low and high vacuum scanning electron microscopy  

British Library Electronic Table of Contents (United Kingdom)

Environmental scanning electron microscopy (ESEM) allows the examination of hydrated and dried specimens without a conductive metal coating which could be advantageous in the imaging of biological and medical objects. The aim of this study was to assess the performance and benefits of wet-mode and low vacuum ESEM in comparison to high vacuum scanning electron microscopy (SEM) using the choroid plexus of chicken embryos as a model, an organ of the brain involved in the formation of cerebrospinal fluid in vertebrates. Specimens were fixed with or without heavy metals and examined directly or after critical point drying with or without metal coating. For wet mode ESEM freshly excised specimens without any pre-treatment were also examined. Conventional high vacuum SEM revealed the characterist...

2011-01-01

323

Recent progress in energy-filtered high energy X-ray photoemission electron microscopy using a Wien filter type energy analyzer  

International Nuclear Information System (INIS)

Energy-filtered X-ray photoemission electron microscopy (EXPEEM) is a microscopy technique which has the potential to provide surface chemical mapping during surface chemical processes on the nanometer scale. We studied the possibilities of EXPEEM using a Wien filter type energy analyzer in the high energy X-ray region above 1000 eV. We have successfully observed the EXPEEM images of Au islands on a Ta sheet using Au 3d_5_/_2 and Ta 3d_5_/_2 photoelectron peaks which were excited by 2380 eV X-rays emitted from an undulator (BL2A) at Photon Factory. Our recent efforts to improve the sensitivity of the Wien filter energy analyzer will also be discussed.

2004-10-15

324

Microsporogenesis and pollen formation in cassava  

British Library Electronic Table of Contents (United Kingdom)

This article describes the complete microsporogenesis and pollen formation in cassava (Manihot esculenta Crantz) at the various developmental stages (pollen mother cell, meiosis, tetrads, early free spore, mid uninucleate, late uninucleate, binucleate and mature pollen grain). Light microscopy, transmission electron microscopy and confocal laser scanning microscopy were used for the study. Floral bud size and other inflorescence characteristics were correlated with specific stages of the microspore development. This association allows a rapid selection of floral buds with similar microspore developmental stages, useful when a large number of homogeneous cells are needed for analysis and for in vitro induction of androgenesis. This article also compares methods for digestion the exine wall ...

2011-01-01

325

Electrodeposition and characterization of Ni-Co/SiC nanocomposite coatings  

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

326

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 ...

2009-07-15

327

Borrelia Burgdorferi ''sensu lato'' in Brazil: Occurrence confirmed by immunohistochemistry and focus floating microscopy  

British Library Electronic Table of Contents (United Kingdom)

In the present study, we report the occurrence of Lyme's borreliosis in patients from the Brazilian Amazon Region. Borreliosis was investigated by immunohistochemistry and focus floating microscopy for Borrelia burgdorferi in skin biopsy samples from 22 patients with both clinical and histopathology evidences compatible with Erythema Migrans. Spirochetes were detected by specific immunohistochemistry and focus floating microscopy for B. burgdorferi in samples from five patients. Clinical cure of the cutaneous lesions was observed in all the patients after treatment with doxycycline regimen as proposed by the Center Disease Control guidelines. A limitation of our study was the fact that we were not able to isolate and culture these organisms. These are the first known Brazilian cases of bor...

2010-01-01

328

Beryllium coating on JET Inconel tiles  

International Nuclear Information System (INIS)

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

2009-10-12

329

Using X-ray Microscopy and Hg L3 XANES to study Hg Binding in the Rhizosphere of Spartina Cordgrass  

UK PubMed Central (United Kingdom)

San Francisco Bay has been contaminated historically by mercury from mine tailings as well as contemporary industrial sources. Native Spartina foliosa and non-native S....Full Text Available

2009-10-01

330

Understanding Enzyme Activity Using Single Molecule Tracking (Poster)  

Energy Technology Data Exchange (ETDEWEB)

This poster describes single-molecule tracking and total internal reflection fluorescence microscopy. It discusses whether the carbohydrate-binding module (CBM) moves on cellulose, how the CBM binds to cellulose, and the mechanism of cellulosome assembly.

2009-06-01

331

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

UK PubMed Central (United Kingdom)

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

332

The role of crystallographic and geometrical relationships between #alpha# and #beta# phases in an #alpha#/#beta# titanium alloy  

International Nuclear Information System (INIS)

The present study has examined for #alpha#/#beta#-Ti alloys the relationship between the morphology and crystallography of Widmanstaetten plates of #alpha#-Ti in colonies within a prior grain of #beta#-Ti. Thus, optical metallography, scanning electron microscopy and transmission electron microscopy have been used to characterize the morphological features of the microstructure, whereas orientation-imaging microscopy (OM) and transmission electron microscopy (TEM) have been employed to reveal crystallographic information. It has been discovered that within a prior #beta#-Ti grain, although the growth direction of the Widmanstaetten plates in given colonies may differ by large angles from #alpha#-plates in other colonies, they may exhibit very close crystallographic relationships. For example, inclined #alpha#-plates may share common basal planes and be related by a rotation of #approx#10.5 deg. about ...

2003-09-15

334

Subventricular Zone Cell Migration: Lessons from Quantitative Two-Photon Microscopy  

UK PubMed Central (United Kingdom)

Neuroblasts born in the adult subventricular zone (SVZ) migrate long distances in the rostral migratory stream (RMS) to the olfactory bulbs where they integrate into circuitry as functional interneurons....Full Text Available

335

Study of the crystallographic architecture of corals at the nanoscale by scanning transmission X-ray microscopy and transmission electron microscopy.  

Science.gov (United States)

We have investigated the nanotexture and crystallographic orientation of aragonite in a coral skeleton using synchrotron-based scanning transmission X-ray microscopy (STXM) and transmission electron microscopy (TEM). Polarization-dependent STXM imaging at 40-nm spatial resolution was used to obtain an orientation map of the c-axis of aragonite on a focused ion beam milled ultrathin section of a Porites coral. This imaging showed that one of the basic units of coral skeletons, referred to as the center of calcification (COC), consists of a cluster of 100-nm aragonite globules crystallographically aligned over several micrometers with a fan-like distribution and with the properties of single crystals at the mesoscale. The remainder of the skeleton consists of aragonite single-crystal fibers in crystallographic continuity with the nanoglobules comprising the COC. Our observation provides information on the nm-scale processes that led to biomineral ...

2011-05-05

336

STRUCTURE OF THE MACULA UTRICULI WITH SPECIAL REFERENCE TO DIRECTIONAL INTERPLAY OF SENSORY RESPONSES AS REVEALED BY MORPHOLOGICAL POLARIZATION  

UK PubMed Central (United Kingdom)

The anatomy of the labyrinth and the structure of the macula utriculi of the teleost fish (burbot) Lota vulgaris was studied by dissection, phase contrast, and electron microscopy....Full Text Available

1964-08-01

337

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

UK PubMed Central (United Kingdom)

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

338

Pulmonary endothelial and bronchiolar epithelial lesions induced by 4-ipomeanol in mice.  

UK PubMed Central (United Kingdom)

The morphogenesis of pulmonary edema and bronchiolar injury induced by the toxic furan, 4-ipomeanol, was studied by combined light and transmission electron microscopy. Weanling male CD-1 mice received...Full Text Available

1985-01-01

339

Optical sectioning of microbial biofilms.  

UK PubMed Central (United Kingdom)

Scanning confocal laser microscopy (SCLM) was used to visualize fully hydrated microbial biofilms. The improved rejection of out-of-focus haze and the increased resolution of SCLM made it preferable...Full Text Available

1991-10-01

340

New strain of mouse hepatitis virus as the cause of lethal enteritis in infant mice.  

UK PubMed Central (United Kingdom)

A new strain of mouse hepatitis virus (MHV) was isolated from pooled gut suspensions from an epizootic of lethal enteritis in newborn mice. Negative-contrast electron microscopy showed an abundance...Full Text Available

1979-05-01

341

Mycobacterium tuberculosis Chaperonin 10 Is Secreted in the Macrophage Phagosome: Is Secretion Due to Dissociation and Adoption of a Partially Helical Structure at the Membrane?  

UK PubMed Central (United Kingdom)

To confirm that Mycobacterium tuberculosis chaperonin 10 (Cpn10) is secreted outside the live bacillus, infected macrophages were examined by electron microscopy. This revealed that...Full Text Available

2003-07-01

342

Mapping the Spatiotemporal Dynamics of Calcium Signaling in Cellular Neural Networks Using Optical Flow  

UK PubMed Central (United Kingdom)

An optical flow gradient algorithm was applied to spontaneously forming networks of neurons and glia in culture imaged by fluorescence optical microscopy in order to map functional calcium signaling...Full Text Available

2010-08-01

343

Location of an epitopic site on epiglycanin by molecular immunoelectron microscopy.  

UK PubMed Central (United Kingdom)

Antibodies of the IgM type present in rabbit anti-epiglycanin antiserum were purified by (NH4)2SO4 precipitation and by ion-exchange, affinity and gel-filtration chromatography. After papain treatment...Full Text Available

1985-04-01

344

LED Arrays as Cost Effective and Efficient Light Sources for Widefield Microscopy  

UK PubMed Central (United Kingdom)

New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission...Full Text Available

346

Intra- and extracellular calcium modulates stereocilia stiffness on chick cochlear hair cells.  

UK PubMed Central (United Kingdom)

Segments of the chick basilar papilla were isolated and maintained in culture medium. The sensory hair bundle of individual hair cells was observed with light microscopy and stimulated with a water...Full Text Available

1994-02-01

347

In vivo confocal microscopy of an apparent deep stroma corneal dystrophy: a case report  

UK PubMed Central (United Kingdom)

A 41-year-old white woman was referred to our Department to rule out the presence of a Fuch's corneal dystrophy. On slit-lamp biomicroscopy, small bilateral punctuate opacities appearing mostly in the...Full Text Available

348

Fourier Transform Infrared Imaging and MR Microscopy Studies Detect Compositional and Structural Changes in Cartilage in a Rabbit Model of Osteoarthritis  

UK PubMed Central (United Kingdom)

Assessment of subtle changes in the primary macromolecular components of cartilage, proteoglycan (PG) and collagen, is critical for the diagnosis of early stages of osteoarthritis (OA), but...Full Text Available

2007-03-01

349

Fear and safety learning differentially affect synapse size and dendritic translation in the lateral amygdala  

UK PubMed Central (United Kingdom)

Fear learning is associated with changes in synapse strength in the lateral amygdala (LA). To examine changes in LA dendritic spine structure with learning, we used serial electron microscopy to re-construct...Full Text Available

2010-05-18

350

Examination of the Rotazyme II enzyme immunoassay for the diagnosis of rotavirus gastroenteritis.  

UK PubMed Central (United Kingdom)

Rotazyme II, which is a shorter version of Rotazyme (less than 3 h), was compared with electron microscopy and Rotazyme for sensitivity and specificity on 229 human stool specimens. Compared with electron...Full Text Available

1985-09-01

351

Electronic and Interfacial Properties of Pd/6H-SiC Schottky Diode ...  

Science.gov (United States)

and palladium silicides (Pd,Si) with a total. AES intensity ratio of Pd to Si of 35/65. Scanning Electron Microscopy. (SEM') of the Pd region shows that ...

352

Drug Susceptibility Testing of Mycobacterium tuberculosis by a Nitrate Reductase Assay Applied Directly on Microscopy-Positive Sputum Samples  

UK PubMed Central (United Kingdom)

Current methods for drug susceptibility testing of Mycobacterium tuberculosis are either costly or slow. As the prevalence of multidrug-resistant strains increases, the need for fast,...Full Text Available

2005-07-01

353

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

354

Confocal microscopy for the analysis of siRNA delivery by polymeric nanoparticles  

UK PubMed Central (United Kingdom)

Clinical applications of genetic therapies, including delivery of short, interfering RNAs (siRNAs) for RNA interference (RNAi), are limited due to the difficulty of delivering nucleic acids...Full Text Available

2010-09-01

355

Cogan's microcystic dystrophy of the cornea: ultrastructure and photomicroscopy.  

UK PubMed Central (United Kingdom)

Corneal biopsy specimens from 3 patients with Cogan's microcystic corneal dystrophy were examined by light and electron microscopy. Specimens were taken from corneas showing microcysts, geographic or...Full Text Available

1978-12-01

356

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

UK PubMed Central (United Kingdom)

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

1994-10-01

357

Analysis of Quantitative Interactions between Two Species of Arbuscular Mycorrhizal Fungi, Glomus mosseae and G. intraradices, by Real-Time PCR  

UK PubMed Central (United Kingdom)

Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs, known to play an important role in ecological processes. Conventional light microscopy is the most common method used to detect their presence...Full Text Available

2006-06-01

358

An improved method for undertaking limiting dilution assays for in vitro cloning of Plasmodium falciparum parasites  

UK PubMed Central (United Kingdom)

BackgroundObtaining single parasite clones is required for many techniques in malaria research. Cloning by limiting dilution using microscopy-based assessment for parasite growth...Full Text Available

359

Acoustic transducer for acoustic microscopy  

Energy Technology Data Exchange (ETDEWEB)

A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

1990-01-01

360

Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences  

Energy Technology Data Exchange (ETDEWEB)

To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and sometimes lower (only 2D intermediate window ...

2010-06-15

361

Corrosion probes for fireside monitoring in coal-fired boilers  

Energy Technology Data Exchange (ETDEWEB)

Corrosion probes are being developed and combined with an existing measurement technology to provide a tool for assessing the extent of corrosion of metallic materials on the fireside in coal-fired boilers. The successful development of this technology will provide power plant operators the ability to (1) accurately monitor metal loss in critical regions of the boiler, such as waterwalls, superheaters, and reheaters; and (2) use corrosion rates as process variables. In the former, corrosion data could be used to schedule maintenance periods and in the later, processes can be altered to decrease corrosion rates. The research approach involves laboratory research in simulated environments that will lead to field tests of corrosion probes in coal-fired boilers. Laboratory research has already shown that electrochemically-measured corrosion rates for ash-covered metals are similar to actual mass loss corrosion rates. Electrochemical tests conducted ...

2005-01-01

362

Computer modelling of eddy current probes for ISI of pressure tube/calandria tube assemblies in PHWRs  

International Nuclear Information System (INIS)

Non-destructive Evaluation (NDE) plays a major role in ensuring the safe and reliable operation of PHWRs which are the mainstay of India's nuclear power programme. An important in-service inspection (ISI) requirement in these reactors is carried out through Eddy Current Testing (ECT) of the pressure tube (PT)/calandria tube (CT) assemblies. The material of construction of these assemblies is zircaloy-2. The two main objectives of this ISI are the detection of garter spring between CT and PT and the profiling of gap between CT and PT. The paper discusses the work carried out at the authors' laboratory on the development of ECT probes for ISI of PT/CT assemblies. Emphasis has been given on the work done on the design and optimisation of the probes using computer modeling. A 2-D finite element code has been developed for this purpose. The code is developed around a diffusion equation which can be derived from Maxwell's equations governing the ...

1991-12-01

363

A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis.  

Science.gov (United States)

We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +/- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +/- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among individual cells by electron ...

1986-01-01

364

A sample preparation for quantitative determination of magnesium in individual lymphocytes by electron probe X-ray microanalysis  

International Nuclear Information System (INIS)

We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among individual cells by electron ...

1986-01-01

365

Transmission electron microscopy of simulated DWPF high level nuclear waste glasses following gamma irradiation  

International Nuclear Information System (INIS)

Thermal analysis testing revealed slight weight changes, which were a function of gamma irradiation, in a highly reduced Defense Waste Processing Facility (DWPF) simulated waste glass. Transmission electron microscopy (TEM) was performed on this glass to determine if the weight change corresponded to microstructural variations. TEM analyses showed that no microstructural changes were attributable to gamma irradiation. Exposure of the samples to the electron beam in the TEM did cause changes in the glass microstructures in some cases. These changes were likely due to localized heating of the glass due to interactions with the transmitted electrons.

1994-04-25

366

The nanoworld through aberration corrected lenses  

International Nuclear Information System (INIS)

The advent of aberration correction for electron microscope lenses has produced a significant advance in the improvement of resolution in microscopy. This improvement, while significant in itself, promises to have its most profound impact in materials science when it delivers quantitative information to challenge models and modellers. This capability for an electron microscope-modelling synergy to deliver useful results at the atomic level is not yet firmly established. For this reason, one of the major challenges for electron microscopy in materials science over this decade is to study systems where electron microscopists and modellers can work collaboratively. This paper explores some examples.

2010-07-01

367

Solution-chemical syntheses of nanostructure HgTe via a simple hydrothermal process  

International Nuclear Information System (INIS)

HgTe rod-shape composed of crystalline particles has been prepared by a hydrothermal method, and characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM). The effects of capping agents, reductants, reaction temperatures, and reaction times on crystal structures and shapes of HgTe have been investigated. The results showed that the CTAB as capping agent plays a crucial role in the hydrothermal process. The synthesis procedure is simple and uses less toxic reagents than the previously reported methods.

2010-06-04

368

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

369

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

International Nuclear Information System (INIS)

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

2001-09-23

370

High resolution transmission electron microscopy of partial states of oxygen order in YBa_2Cu_3O_z  

International Nuclear Information System (INIS)

This paper reports on high resolution electron microscopy used to investigate the effect of electron irradiation induced oxygen loss on the states of partial order in YBa_2Cu_3O_z. Contrast effects visible in the [001] zone image as a result of the degree of the out-of-plane correlation of these ordered states are investigated. Using statistical simulations to aid in the analysis of the HREM images, an interpretation based on a kinetically limited evolution of the variation of long range [001] ordering is proposed.

1990-04-16

371

Environmental scanning electron microscopy  

Energy Technology Data Exchange (ETDEWEB)

The ElectroScan environmental scanning electron microscope (ESEM) is one of the most exciting new developments in the field of Electron Microscopy. The ESEM differs from conventional Scanning Electron Microscopes (SEM) by being able to examine materials including liquids and oils in their natural state with no prior sample preparation. Accessory equipment, cooling, heating and manipulating devices allow the manipulation of samples thus making it possible for the first time to image dynamic processes such as wetting, drying, absorption, corrosion, melting, crystallisation, curing and fracturing at high magnification. Papers concerning the historical development of the ESEM are given in a bibliography at the end of this paper. 24 refs., 18 figs.

1994-12-31

372

Electron microscopy study of thermomechnical deformation conditions effect on the structure of two-phase (#alpha#+#beta#) titanium alloys  

International Nuclear Information System (INIS)

The methods of optical and transmission electron microscopy were used to study the influence of different programmes of hot deformation on the structure formation of (#alpha#+#beta#) titanium alloy VT9. The #beta# alloy VT-15 was studied at the same time in order to simulate the dislocation structure generated in the process of hot deformation. During the hot deformation of two-phase titanium alloys in both #beta# and (#alpha#+#beta#) ranges there is found to be an optimum range of deformation in which a homogeneous, polygonized structure is formed.

373

Direct observations of dislocation substructures formed by nano-indentation of the #alpha#-phase in an #alpha#/#beta# titanium alloy  

International Nuclear Information System (INIS)

Nano-indentation has been used to assess the hardness of equiaxed grains of #alpha#-Ti as a function of orientation. Surface normals of these grains in metallographic sections were assessed using orientation imaging microscopy. Thin membranes of material from below a series of nano-indentations were excised by use of a dual-beam focused ion beam instrument. In this way, the dislocation substructures beneath individual indentations were characterized using transmission electron microscopy, permitting an identification of both statistically stored and geometrically necessary dislocations.

2005-07-25

374

Application of light microscopy to direct coal liquefaction research  

Energy Technology Data Exchange (ETDEWEB)

Light microscopy was used to analyze the effects of added catalyst at different conditions (temperature and reaction times) in liquefaction testing of a low pyritic sulfur bituminous coal. Quantitative changes in vitrinite/vitroplast reflectance of coal and liquefaction residues were shown to be useful markers in analyzing and understanding the role of catalyst during the initial stage of coal particle hydrogenation. Lower reflectance values corresponded to increased conversions up to about the 60 min and 375{degrees}C experimental conditions. Microscopical observation of liquefaction residues also revealed the presence of `wall scales` of varying width.

1998-01-01

375

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 ...

2006-02-22

376

Versatile high intensity plasma sputter heavy negative ion source  

Energy Technology Data Exchange (ETDEWEB)

A multicusp magnetic field plasma surface ion source, normally used for H/sup -/ ion beam formation, has been utilized for the generation of high intensity, pulsed, heavy negative ion beams suitable for a variety of uses including tandem electrostatic accelerator/synchrotron injection applications. Sputter probe voltage limited total ion currents of 5.5, 8.2, 5.1 and 4.5 mA (peak intensity) have been produced from Au, Cu, Ni and CuO sputter probes, respectively. The mass distributions of these ion beams are found to be dominated by Au/sup -/, Cu/sup -/, Ni/sup -/ and O/sup -/ atomic species, respectively. The source offers the interesting prospect of providing cw negative ion beams at mA intensity levels of the commonly used semiconducting material dopants (e.g. B/sup -/, P/sup -/, As/sup -/ and Sb/sup -/) as well as O/sup -/ for isolation barrier formation. Illustrative examples of intensity versus time and the mass distribution of ion beams ...

1988-07-01

377

Monitoring power plant fireside corrosion using corrosion probes  

Energy Technology Data Exchange (ETDEWEB)

The ability to monitor the corrosion degradation of key components in fossil fuel power plants is of utmost importance for Futuregen and ultra-supercritical power plants. Fireside corrosion occurs in the high temperature sections of energy production facilities due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Problems occur when equipment designed for either oxidizing or reducing conditions is exposed to alternating oxidizing and reducing conditions. This can happen especially near the burners. The use of low NOx burners is becoming more commonplace and can produce reducing environments that accelerate corrosion. One method of addressing corrosion of these surfaces is the use of corrosion probes to monitor when process changes cause corrosive conditions. In such a case, corrosion rate could become a process control variable that directs the operation of a coal combustion or coal gasification ...

2005-01-01

378

Electrochemical detection of DNA hybridization based on silver-enhanced gold nanoparticle label  

Energy Technology Data Exchange (ETDEWEB)

An electrochemical detection method for analyzing sequence-specific DNA using gold nanoparticle DNA probes and subsequent signal amplification step by silver enhancement is described. The assay relies on the electrostatic adsorption of target oligonucleotides onto the sensing surface of the glassy carbon electrode (GCE) and its hybridization to the gold nanoparticle-labeled oligonucleotides DNA probe. After silver deposition onto gold nanoparticles, binding events between probe and target were monitored by the differential pulse voltammetry (DPV) signal of the large number of silver atoms anchored on the hybrids at the electrode surface. The signal intensity difference permits to distinguish between the match of two perfectly matched DNA strands and the near-perfect match where just one base pair was wrong. Coupled with this 'nanoparticle-promoted' reduction of silver signal amplification method, the ...

2002-10-03

379

Char particle fragmentation and its effect on unburned carbon during pulverized coal combustion. Quarterly report, October 1, 1993--December 31, 1993  

Energy Technology Data Exchange (ETDEWEB)

The information reported is for the period October I to December 31, 1993. During this quarter, activities were undertaken in Task 2. Oxygen concentrations were measured in the post-flame region of the entrained flow reactor. The sampling probe was used for the hot gas tests to sample the gas stream. Samples were injected into a gas chromatograph to determine the oxygen concentration. Results agreed with thermoequilibrium calculations that yield equilibrium compositions based on the stoichiometry of the feed gases. The axial temperature distribution along the reactor centerline was measured using a silica-coated platinum-rhodium thermocouple. Two coating techniques were tested and it was found that flame-plating silica to the thermocouple wires produced a thinner coating than a ceramic adhesive technique and therefore a smaller radiation correction. Other activities this quarter included the fabrication of a solids sampling probe support ...

1994-02-01

380

Strong laser fields as a probe for fundamental physics  

CERN Document Server

Upcoming high-intensity laser systems will be able to probe the quantum-induced nonlinear regime of electrodynamics. So far unobserved QED phenomena such as the discovery of a nonlinear response of the quantum vacuum to macroscopic electromagnetic fields can become accessible. In addition, such laser systems provide for a flexible tool for investigating fundamental physics. Primary goals consist in verifying so far unobserved QED phenomena. Moreover, strong-field experiments can search for new light but weakly interacting degrees of freedom and are thus complementary to accelerator-driven experiments. I review recent developments in this field, focusing on photon experiments in strong electromagnetic fields. The interaction of particle-physics candidates with photons and external fields can be parameterized by low-energy effective actions and typically predict characteristic optical signatures. I perform first estimates of the accessible new-physics parameter space ...

2008-01-01

381

Properties of different eddy-current probes for steam generator tube testing  

Energy Technology Data Exchange (ETDEWEB)

With steam generator check testing, the numerous types of defect not only have to be detected reliably but also to be identified correctly and classified according to depth. A priori, no signals are provided by the physical eddy-current mechanism, i.e. the disturbance of an excited eddy-current field by a defect, which will allow unambiguous identification and classification of the defects. The task, therefore, consists in designing the eddy-current method in terms of measurement technology in such a way as to obtain useful detection, identification and classification by a translation of the signals as simple and as save as possible. Internal through-flow wils and internal rotating probes were examined for their suitability to fulfill this three-pronged task with steam generator inspection.

1981-01-01

382

Properties of different eddy-current probes for steam generator tube testing  

International Nuclear Information System (INIS)

With steam generator check testing, the numerous types of defect not only have to be detected reliably but also to be identified correctly and classified according to depth. A priori, no signals are provided by the physical eddy-current mechanism, i.e. the disturbance of an excited eddy-current field by a defect, which will allow unambiguous identification and classification of the defects. The task, therefore, consists in designing the eddy-current method in terms of measurement technology in such a way as to obtain useful detection, identification and classification by a translation of the signals as simple and as save as possible. Internal through-flow wils and internal rotating probes were examined for their suitability to fulfill this three-pronged task with steam generator inspection. (orig./RW).

1981-01-01

383

Plasma density measurement of electron cyclotron resonance ion source for neutron generator  

International Nuclear Information System (INIS)

It is a traditional method to diagnose electron-cyclotron-resonance (ECR) plasma source, using a single probe to measure the current-voltage curve of the plasma, based on which and theoretic formula the plasma density can be computed. The article adopts a Langmuir probe having a role of emission electrons to measure two different current-voltage curves with and without emission. It is ease to get the plasma potential via the inflexion of the two curves and compute directly various physical quantities by the assistant computer, such as electron temperature, electron/ion density, plasma potential etc. The deviation is about percent 1.8 between the measurement results by traditional and the new method, but the latter has higher efficiency. (authors)

2007-12-01

384

Metal ion complexation by ionizable crown ethers  

Energy Technology Data Exchange (ETDEWEB)

Research conducted since the last progress report includes the synthesis and characterization of twenty three novel proton-ionizable crown ether compounds. Metal ion complexation behavior of new and previously-synthesized proton-ionizable crown ether compounds has been probed by solvent extraction and transport across polymer-supported liquid membranes. The behavior of neutral polyether and proton-ionizable polyether ligands in polymeric membrane electrodes has been assessed. Studies of the use of proton-ionizable crown ethers for separation of lithium isotopes were initiated. Also, the thermodynamics of interactions between alkali metal cations and ionized crown ethers have been probed by titration calorimetry. 10 refs., 1 tab.

1989-09-01

385

Joule-Thomson cryogenic cooler with extremely high thermal stability  

Science.gov (United States)

An 80-K Joule-Thomson (J-T) cooling system designed for the Probe Infrared Laser Spectrometer (PIRLS) proposed for the Huygens Titan Probe of the Cassini Saturn orbiter mission is presented. The cryogenic cooling requirements of the PIRLS instrument are listed, and the cooler system design including details of a J-T cryostat, cold head, and dewar design is described along with the results of a thermal modeling effort and lab cooler performance testing. It is shown that by using active feedback temperature control of the cold head in combination with the self-regulating action of the J-T cryostat, a temperature stability of less than 0.1 mK/min is achieved by the cooler weighting 1.8 kg.

1991-06-01

386

Gradiometry coexperiments to the gravity probe B and step missions  

Energy Technology Data Exchange (ETDEWEB)

The Gravity Probe-B (GP-B) spacecraft, designed to test predictions of general relativity, will fly in the mid 1990s. It will carry four electrostatically suspended gyroscopes in a cryogenic environment and will have a drag-free control system to minimize disturbances on the gyroscopes. The Stanford Test of Equivalence Principle (STEP) spacecraft, to fly later, will carry a set of test masses under very similar conditions. The possibility of using differential measurements of the GP-B gyroscopes suspension forces and the STEP tests mass displacement readout to form single-axis gravity gradiometers is explored. It is shown that the noise in the suspension systems is sufficiently small in the relevant frequency range, and that enough information is collected to compensate for the spacecrafts' attitude motion. Finally, using Breakwell's flat-earth approximation, these experiments are compared to other geodesy experiments and predict the contribution ...

1990-01-01

387

From dispersion relations to spectral dimension - and back again  

CERN Document Server

The so-called spectral dimension is a scale-dependent number associated with both geometries and field theories that has recently attracted much attention, driven largely though not exclusively by investigations of causal dynamical triangulations (CDT) and Horava gravity as possible candidates for quantum gravity. We advocate the use of the spectral dimension as a probe for the kinematics of these (and other) systems in the region where spacetime curvature is small, and the manifold is flat to a good approximation. In particular, we show how to assign a spectral dimension (as a function of so-called diffusion time) to any arbitrarily specified dispersion relation. We also analyze the fundamental properties of spectral dimension using extensions of the usual Seeley-DeWitt and Feynman expansions, and by saddle point techniques. The spectral dimension turns out to be a useful, robust and powerful probe, not only of geometry, but also of ...

2011-01-01

388

Final report: technical contributions to the development of incipient fault detection/location instrumentation  

Energy Technology Data Exchange (ETDEWEB)

The transmission of electrical energy by use of underground cables is increasing. Fault location techniques have certain limitations; incipient fault detection and location would help reduce the maintenance cost of these lines as well as improve the reliability of service. The report discusses some test results related to RF-probing techniques applied to high-voltage transmission lines. The high-frequency losses and attenuation in high-voltage cables places certain ultimate limitations on RF-probing techniques for incipient fault detection. Time-domain reflectrometry methods were employed to assess the RF-transmission properties of high-voltage cables at frequencies as high as 6 GHz. Fast-Fourier-transform deconvolution was used to obtain loss measurements as a function of frequency. The loss mechanisms were identified. The measurement hardware and methods are discussed as well as analysis approach leading to the conclusions.

1986-04-01

389

Erosive radially-slotted discharge in sheet current mode  

CERN Document Server

New non-stationary non-contracted form of the erosive radially-slotted discharge as a thin round sheet with the current of the azimuth direction have been discovered, its existence beings stipulated by a radial transport-wave fluxes. Characteristic features of this discharge is self-confinement of the discharge current magnitude, corresponding decrease of the current pulse duration and occurrence of an energy and substance ejection with rather unusual properties. Measurements of kinetics of the discharge current, the plasma radiation intensity and an electrical probe signal, as well as the transmission electron microscope investigations of characteristic aerodisperse aggregates arising the erosive phase, have been carried out. The probe signal duration was about 10 times greater than that of the current; its kinetics was complicated suggesting existence in the slot of two components with fundamentally different properties and states of the ...

2001-01-01

390

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants  

International Nuclear Information System (INIS)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostic system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1992-01-01

391

Development of in-vessel reflood instrumentation at ORNL  

International Nuclear Information System (INIS)

A program under the sponsorship of the United States Nuclear Regulatory Commission was intiated at the Oak Ridge National Laboratory (ORNL) in late 1977. The program, Advanced Instrumentation for Reflood Studies (AIRS), is charged with developing instrumentation for measurement of in-vessel fluid phenomena in pressurized water reactor reflood facilities. The goal of the ORNL program is to develop techniques and systems for measuring fluid flow in-core, deentrainment in the upper plenum and liquid fallback from the upper plenum into the core. A large portion of the development at ORNL is devoted to the impedance probes for measurement of two-phase flow velocities and void fractions. Film probe development at ORNL is limited to adapting the present techniques to the environment of a reflood facility. As the development progresses on all the measurement techniques, ORNL will fabricate and supply instrument systems to the reflood facilities ...

2004-09-06

392

Development of SDT sensor based eddy current probe for detection of deep fatigue cracks in multi-layer structure  

British Library Electronic Table of Contents (United Kingdom)

The detection and characterization of deeply buried fatigue damage in thick, multi-layer airframe components pose significant technical challenges to the aviation safety community. Currently, no nondestructive evaluation technique is available to reliably detect such potential damage from the exterior of the airframe, which is highly desirable in light of inspection cost as well as avoidance of structure damage. Recent technological advances in high-sensitivity magnetic sensors, i.e., spin-dependent tunneling (SDT) sensors, make it feasible to employ electromagnetic inspection techniques for deep fatigue crack inspection. In this work, we report on the development and fabrication of a low frequency eddy current probe based on a magnetically shielded SDT pickup sensor concentrically located...

2010-01-01

393

Development and operational experience of traveling in core probe drive for flux scan of 540 MWe PHWR of Tarapur  

International Nuclear Information System (INIS)

TAPP-3 and 4 reactors use large number of Self Powered Neutron Detectors (SPNDs) for Neutronic lower measurement and control. To perform in-situ calibration of these detectors in select locations and to validate the reactor physics codes which predict flux at various points in the core, traveling in-core probes (TIP) are required. The TIP assembly consists of a miniature neutron sensitive detector. The detector is driven in and out of core using a mechanism which facilitates positioning of the detector anywhere inside a vertical tube (Central carrier tube of any of the six select Vertical Flux Units) in the core. TIP is driven through retractable feed mechanism for a stroke of 13 m. This paper describes the developmental efforts and the operational feedback of the retractable feed mechanism for the stroke of 13 m used at TAPP 3 and 4 reactor. (author)

2006-11-13

394

Density measurements of coal samples by different probe gases and their interrelation  

Energy Technology Data Exchange (ETDEWEB)

Density is useful in deducing the spatial structure of coals. In this paper, nitrogen has been used instead of the commonly employed helium, for the gas displacement pycnometer based density determination of a number of coals of Indian origin. The results show that the nitrogen-based densities are always higher than the helium-based ones. Also, empirical relationships between the helium-based and nitrogen-based coal densities have been developed by two modeling methods, namely, multi-variable regression and artificial neural networks. Although the two models have fared well, the neural network model exhibits a relatively better prediction accuracy and generalization performance than the regression model. This study thus demonstrates that nitrogen, which is cheaper and easily available, can be used gainfully as the probe gas for estimating the true density of coals. 23 refs., 1 fig., 3 tabs.

2007-07-15

395

Comparison of fluorescence in situ hybridisation using peptide nucleic acid probes, Gram stain/acridine orange leukocyte cytospin and differential time to positivity methods for detection of catheter related bloodstream infection in patients after haematopoietic stem cell transplantation  

British Library Electronic Table of Contents (United Kingdom)

Abstract In 46 febrile neutropenic patients who had undergone haematopoietic stem cell transplantation, the fluorescence in situ hybridisation using peptide nucleic acid probes (PNA FISH), Gram stain/acridine orange leukocyte cytospin (Gram/AOLC), and differential time to positivity (DTP) methods were performed for detection of catheter related bloodstream infections (CRBSIs). As compared with the DTP method (which detected 11 patients with CRBSI), the PNA FISH and the Gram/AOLC methods detected ten of 11 CRBSI patients, resulting in a sensitivity, specificity, negative predictive value and positive predictive value of 91%, 100%, 97% and 100%, respectively, for the PNA FISH method as well as for the Gram/AOLC method.

2010-01-01

396

Assessing the acid properties of desilicated ZSM-5 by FTIR using CO and 2,4,6-trimethylpyridine (collidine) as molecular probes  

British Library Electronic Table of Contents (United Kingdom)

A series of desilicated ZSM-5 catalysts previously shown to have improved catalytic performance in the MTG (methanol-to-gasoline) reaction [M. Bjorgen, F. Joensen, M.S. Holm, U. Olsbye, K.-P. Lillerud, S. Svelle, Appl. Catal. A 345 (2008) 43] was subjected to thorough examination using FTIR. Clearly, defects represented by internal Si-OH sites are removed upon NaOH treatment. In a parallel manner, free Si-OH sites increase in concentration and the results point to a selective mechanism for formation of mesopores as the framework dissolution preferentially takes place at defective sites in the crystallites. The acid properties of the desilicated materials were investigated by applying CO and collidine (2,4,6-trimethylpyridine) as molecular probes. Monitoring the induced frequency shifts upo...

2009-01-01

397

A pump-probe XFEL particle injector for hydrated samples  

CERN Document Server

We have developed a liquid jet injector system that can be used for hydrated sample delivery at X-ray Free Electron Laser (XFEL) sources and 3rd generation synchrotron sources. The injector is based on the Gas Dynamic Virtual Nozzle (GDVN), which generates a liquid jet with diameter ranging from 300 nm to 20 {\\mu}m without the clogging problems associated with conventional Rayleigh jets. An improved nozzle design is presented here. A differential pumping system protects the vacuum chamber and an in-vacuum microscope allows observation of the liquid jet for diagnostics while it is being exposed to the X-ray beam. A fiber optically coupled pump laser illuminating the jet is incorporated for pump-probe experiments. First results with this injector system have been obtained at the LCLS.

2011-01-01

398

A Network Coding Approach to Loss Tomography  

CERN Document Server

Network tomography aims at inferring internal network characteristics based on measurements at the edge of the network. In loss tomography, in particular, the characteristic of interest is the loss rate of individual links. There is a significant body of work dedicated to this problem using multicast and/or unicast end-to-end probes. Independently, recent advances in network coding have shown that there are several advantages from allowing intermediate nodes to process and combine, in addition to just forward, packets. In this paper, we pose the problem of loss tomography in networks that have network coding capabilities. We design a framework for estimating link loss rates, which leverages network coding capabilities and we show that it improves several aspects of tomography, including the identifiability of links, the tradeoff between estimation accuracy and bandwidth efficiency, and the complexity of probe path selection. We discuss the ...

2010-01-01

399

Vibrational population dynamics in liquids and glasses: IR pump-probe experiments from 10 K to 300 K  

Energy Technology Data Exchange (ETDEWEB)

The temperature dependent vibrational relaxation of the CO stretching mode of Rhodium dicarbonyl acetylacetonate (Rh(CO){sub 2}(acac)) and tungsten hexacarbonyl (W(CO){sub 6}) in dibutylphthalate (DBP) and 2-methylpentane (2-MP) were measured with IR pump and probe (P-P) experiments. The experiments were performed with {approximately}1.5 ps pulses generated by the Stanford superconducting accelerator pumped free electron laser (FEL). Measurements were performed on the Rh(CO){sub 2}(acac) CO asymmetric stretching mode at {lambda} = 4.98{mu}m from 10 K to 300 K. Both the parallel and magic angle probe polarizations decay curves are biexponential over the entire temperature range. The slow component (ranging from 40 ps at 300 K to 55 ps at 10K) is attributed to the population relaxations. For the fast component (ranging from 4-5 ps at 300 K to 13-15 ps at 10K), we propose a mechanism of spectral diffusion, in contrast to the previously proposed ...

1995-12-31

400

Thyroidal uptake of iodine-123 in children using a gamma camera and computer  

Energy Technology Data Exchange (ETDEWEB)

The measurement of thyroidal uptake of radioiodine using a gamma camera and computer is described. In 12 children there was good agreement with simultaneous measurements using a probe, while in a further 14 patients the uptake values were consistent with the clinical diagnosis. The technique should be especially useful for infants and small children.

1985-10-01

401

The Universal Dark Matter  

CERN Document Server

Fragile volatile aggregates with extremely low albedo, gravitationally drawn into the solar system are likely from the dark matter dominating the universal mass. Characteristics of this meteoric population permitted avoiding detection through a half-century's search. Measurements from space probes and in the upper atmosphere prove their existence and confirm their elusive properties.

2006-01-01

402

The Fenton oxidation mechanism: reactivities of biologically relevant substrates with two oxidizing intermediates differ from those predicted for the hydroxyl radical.  

UK PubMed Central (United Kingdom)

The application of kinetic probes that allow one to determine relative reactivities of biologically relevant substrates with oxidizing intermediates in the Fenton reagent (H2O2 plus Fe2+ in acidic aqueous...Full Text Available

1994-07-05

403

The Cause of an Eddy Current Signal Noise from a Steam Generator Tube and its Effect on the Detectability of a Crack  

International Nuclear Information System (INIS)

An eddy current inspection has been applied for a pre-service and in-service examination of a steam generator in nuclear power plants. The experience from the inspection of steam generators showed that many plants had an excessive number of tubes with eddy current noise signals over several hundreds, which originated from manufacturing anomalies. The plants in U.S suffered significant downstream inspection costs, history reviews, and diagnostic testing because some signals resembled flaws and others masked a flaw. These lessens learned resulted in issuing the guidelines for steam generator tubing specifications and repair, in order to reduce the number of anomalous signals in the tubes and also to provide the requirement of a signal to noise ratio by applying a field type examination with bobbin coil eddy current probes at a manufacturing process. Besides the noise signals of a bobbin coil eddy current probe from manufacturing anomalies, the ...

2008-05-01

404

Single Atom Detection With Optical Cavities  

CERN Document Server

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

2008-01-01

405

Radon in soil gas survey in Curitiba (Brazil)  

International Nuclear Information System (INIS)

This work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. After the Probe was inserted, the ground has been tamped down around the probe, to prevent air ...

2002-10-08

406

Radial distribution of bonded fission gas in mixed carbide fuel pins  

International Nuclear Information System (INIS)

The fission gas xenon bonded in bubbles, in pore, and in the lattice of mixed carbide fuels is measured by electron-probe microanalysis. Radial xenon distribution and release curves are determined and are calibrated by gas chromatography of the bonded fission gas and by burnup analysis in the respective pin sections of the irradiation experiments FR2 6A and 6C, Mol 11/K 2, and DFR 330/1. The results are correlated to the microstructure of the fuel, bonding medium, temperature, and burnup. (Auth.).

1979-01-01

407

Radial distribution functions of amorphous silicon  

Energy Technology Data Exchange (ETDEWEB)

Substantial changes in the radial distribution function of amorphous Si films have been observed in neutron-diffraction studies. The spectra indicate changes in short-range order associated with an approx.11% modification in the bond-angle distribution width. The results allow the first direct comparison of structural and vibrational Raman probes of variations in local order in thin-film amorphous solids. Good agreement is obtained between the measured bond-angle variation and that based on Raman estimates.

1989-03-15

408

Platinum(II) complexes as spectroscopic probes for biomolecules  

Energy Technology Data Exchange (ETDEWEB)

The use of platinum(II) complexes as tags and probes for biomolecules is indeed advantageous for their reactivities can be selective for certain purposes through an interplay of mild reaction conditions and of the ligands bound to the platinum. The use of {sup 195}Pt NMR as a method of detecting platinum and its interactions with biomolecules was carried out with the simplest model of platinum(II) tagging to proteins. Variable-temperature {sup 195}Pt NMR spectroscopy proved useful in studying the stereodynamics of complex thioethers like methionine. The complex, Pt(trpy)Cl{sup +}, with its chromophore has a greater potential for probing proteins. It is a noninvasive and selective tag for histidine and cysteine residues on the surface of cytochrome c at pH 5. The protein derivatives obtained are separable, and the tags are easily quantitated and differentiated through the metal-to-ligand charge transfer bands which are sensitive to the ...

1990-09-21

409

Movable genetic elements: detection of changes in maize DNA at the Shrunken locus due to the intervention of Ds elements  

Science.gov (United States)

This report describes our initial attempts at the molecular characterization of a maize controlling element. We have prepared a cDNA probe and used it to detect changes at a locus where Ds elements are found. Evidence of their presence are indicated by changes in the restriction patterns, but there is as yet no information on the physical nature of the controlling elements nor on the kinds of rearrangements they cause.

1980-05-28

410

Molecular characterization of the Spirometra mansonoides genome: renaturation kinetics, methylation, and hybridization to human cDNA probes.  

Science.gov (United States)

High molecular weight DNA from pleroceroid larvae of the tapeworm Spirometra mansonoides was purified from isolated nuclei by conventional techniques. The DNA so isolated has a melting temperature (Tm) of 87 degrees C and a guanine plus cytosine (G/C) content of 44%. 5-Methyl cytosine could not be detected in plerocercoid DNA by HPLC analysis of DNA hydrolysates, by radiolabeling 5'-termini of MspI digests with polynucleotide kinase, or by comparing restriction patterns generated by MspI and HpaII. Renaturation kinetics demonstrated that the genome of S. mansonoides contains repetitive as well as single copy sequences and has a genome size estimated at approx. 1.6 X 10(9) bp. Hybridization was carried out between plerocercoid DNA and cDNAs for human beta-actin, alpha-tubulin and growth hormone (hGH). Rationale for this analysis was based on known homologies among actin and tubulin genes in numerous species and on apparent similarities between hGH and a plerocercoid growth factor that ...

1990-06-21

411

Lagrangian analysis of contaminant dispersal in bounded turbulent shear flows  

Energy Technology Data Exchange (ETDEWEB)

Methods of solving Navier-Stokes equations for turbulent channel flow are given. These numerical solutions utilize either Neumann or Dirichlet boundary conditions. Computer codes were written and tested and are discussed. Digital image processing of flow visualization video sequences, taken simultaneously with vorticity probe measurements in a turbulent boundary layer, were carried out. 4 figs. (GHH)

1991-01-01

412

Isolation, sequence, and expression in Escherichia coli of an unusual thioredoxin gene from the cyanobacterium Anabaena sp. strain PCC 7120.  

UK PubMed Central (United Kingdom)

Two sequences with homology to a thioredoxin oligonucleotide probe were detected by Southern blot analysis of Anabaena sp. strain PCC 7120 genomic DNA. One of the sequences was shown to code for a protein...Full Text Available

1989-01-01

413

High-resolution primary ion beam probe for SIMS  

Energy Technology Data Exchange (ETDEWEB)

High-brightness negative ion beams, especially O{sup -} beams, from a compact gaseous plasma source are studied to evaluate the suitability for high-resolution SIMS. Ion-optical calculations are made using the beam parameters from the new source. Results suggest that sub-100 nm spot with O{sup -} beam current of 10 pA is achievable. Beam focusing, the resulting beam current distributions at the target and the expected instrumental performance are discussed.

2004-06-15

414

High throughput protein fold identification by using experimental constraints derived from intramolecular cross-links and mass spectrometry  

UK PubMed Central (United Kingdom)

We have used intramolecular cross-linking, MS, and sequence threading to rapidly identify the fold of a model protein, bovine basic fibroblast growth factor (FGF)-2. Its tertiary structure was probed...Full Text Available

2000-05-23

415

Fusion of GFP to the M.EcoKI DNA methyltransferase produces a new probe of Type I DNA restriction and modification enzymes  

UK PubMed Central (United Kingdom)

AbstractWe describe the fusion of enhanced green fluorescent protein to the C-terminus of the HsdS DNA sequence-specificity subunit of the Type I DNA modification methyltransferase M.EcoKI....Full Text Available

2010-07-23

416

Electroweak symmetry breaking at photon colliders  

Energy Technology Data Exchange (ETDEWEB)

The electroweak-symmetry-breaking sector of the standard model can be weakly-coupled or can be strongly-coupled, which is characterized by some kinds of strong interaction among the Goldstone bosons of the electroweak-symmetry-breaking sector. In this paper, we summarize an investigation of probing the strong electroweak-symmetry-breaking effects at photon colliders. ((orig.)).

1995-02-01

417

Electroweak symmetry breaking at photon colliders  

International Nuclear Information System (INIS)

The electroweak-symmetry-breaking sector of the standard model can be weakly-coupled or can be strongly-coupled, which is characterized by some kinds of strong interaction among the Goldstone bosons of the electroweak-symmetry-breaking sector. In this paper, we summarize an investigation of probing the strong electroweak-symmetry-breaking effects at photon colliders. ((orig.)).

418

Eddy current signal analysis techniques for assessing degradation of support plate structures in nuclear steam generators  

Energy Technology Data Exchange (ETDEWEB)

The steam generator (SG) is one of the most critical components of the heat transfer system in nuclear generation stations. Testing the structural integrity of SG tubing and SG internals is a key element of the fitness-for-service assessments to assure the safe and continuous operation of nuclear power plants. Recent eddy current (ET) inspections of two nuclear power plants revealed degradation of some of the tube support plate (TSP) structures, which was also confirmed by visual inspection. The phenomena was described as metal loss, caused by flow-accelerated corrosion of the carbon steel trefoil support plate and varying from minor to complete loss of the ligaments. This loss of TSP ligaments results in lack of support for the adjacent tubes making them more susceptible to fretting-wear damage and fatigue cracking. A signal analysis method, based on the responses at low frequency of two types of eddy current probes, has been developed to assess the degree of ...

2006-07-01

419

Eddy current imaging  

Energy Technology Data Exchange (ETDEWEB)

Image representations have gained wide acceptance in displaying data collected during optical, ultrasonic, radiographic, and thermographic inspections. Applying imaging techniques to eddy current testing is explored in this article. The authors show that flaw interpretation and characterization are made considerably simpler when images are used to visualize the impedance changes in eddy current probes.

1993-04-01

420

Development of video probe system for inspection of feeder pipe support in calandria reactor  

Energy Technology Data Exchange (ETDEWEB)

There are 760 feederpipes, which they are connected to inlet/outlet of the 380 pressure tube channels on the front of the calandria, in CANDU-type Reactor of Wolsung Nuclear Power Plant. As an ISI(In-Service Inspection) and PSI (Post- Service Inspection) requirements, maintenance activities of measuring the thickness of curvilinear part of feederpipe and inspecting the feederpipe support area within calandria are needed to ensure continued reliable operation of nuclear power plant. And untrasonic probe is used to measure the thickness of curvilinear part of feederpipe, however workers are exposed to radioactivity irradiation during the measurement period. But, it is impossible to inspect feederpipe support area thoroughlv because of narrow and confined accessibility, that is, an inspection space between the pressure tube channels is less than 100mm and pipes in feederpipe support area are congested. And also, workers involved in inspecting feederpipe support area ...

2000-07-01

421

Design, synthesis, and testing of difluoroboron derivatized curcumins as near infrared probes for in vivo detection of amyloid-? deposits  

UK PubMed Central (United Kingdom)

Amyloid-β (Aβ) deposits have been identified as key players in the progression of Alzheimer’s disease (AD). Recent evidence indicates that the deposits probably precede...Full Text Available

2009-10-28

422

Critical current measurements of high Tc superconductors in a scanning low temperature cryostat  

Energy Technology Data Exchange (ETDEWEB)

Maintaining uniformity of properties over long distances is one of the fabrication problems encountered with the new high {Tc} superconductors. Uniform properties are crucial in long tapes or wires with high critical current since local nonuniformities can limit the current carrying capacity of the whole piece. Transport critical currents in high {Tc} superconductors are conventionally measured with the contact 4-point probe DC current-voltage technique. This technique requires contact with the sample and and spatially averages over the region between the two voltage contacts. Two techniques have been used to infer the critical state model. The first uses the net magnetization of a suitably shaped sample in an external magnetic field. The second combines a DC magnetic field with AC induced currents to infer spatial flux profiles. The AC magnetization technique offers an advantage in that it is noncontacting; however, it also averages the measurement over a large ...

1991-01-01

423

Cloning of rice DNA and identification of tRNA gene clones  

Energy Technology Data Exchange (ETDEWEB)

DNA from 48 hr germinated rice embryos was cut with restriction endonuclease Bam H1 and cloned to the Bam H1 site on plasmid pBR 322. The clones containing recombinant DNA were selected by their sensitivity to tetracycline and resistance to ampicillin. Using /sup 32/P-labelled rice embryos tRNA as a probe two clones were identified to contain tRNA genes by colony hybridization.

1981-10-20

424

Aluminum hydroxide coating thickness measurements and brushing tests on K West Basin fuel elements  

Energy Technology Data Exchange (ETDEWEB)

Aluminum hydroxide coating thicknesses were measured on fuel elements stored in aluminum canisters in K West Basin using specially developed eddy current probes . The results were used to estimate coating inventories for MCO fuel,loading. Brushing tests successfully demonstrated the ability to remove the coating if deemed necessary prior to MCO loading.

1998-09-11

425

Activation and Stiffness of the Inhibited States of F1-ATPase Probed by Single-molecule Manipulation  

UK PubMed Central (United Kingdom)

F1-ATPase (F1), a soluble portion of FoF1-ATP synthase (FoF1), is an ATP-driven motor in which γϵ subunits rotate in...Full Text Available

2010-04-09

426

A tube inspection device. Dispositif de controle de tubes  

Energy Technology Data Exchange (ETDEWEB)

The device, aimed at non destructive control of the inner side of tubes such as steam generator tubes, is composed of a control sensor mounted on a support; the sensor head may rotate in the tube and a measuring system and signal processing allow for the exact determination of the angular position of the sensor head (application to ultrasonic or eddy current probes).

1993-05-07

427

A legal-historical consideration of links between Canadian and South African racial policies  

British Library Electronic Table of Contents (United Kingdom)

Significant recent writings have suggested strong parallels and actual links between the historical legal architectures of Canadian Aboriginal policy and South African apartheid. This article's further probing of these claims shows them to be very doubtful. At the same time, some more limited legal parallels between the two systems shows the importance of undertaking further analysis of the transmission and exchange of legal ideas and norms within the Commonwealth order.

2010-01-01

428

5'-Azido-[3,6-3H2]-1-napthylphthalamic acid, a photoactivatable probe for naphthylphthalamic acid receptor proteins from higher plants: identification of a 23-kDa protein from maize coleoptile plasma membranes.  

UK PubMed Central (United Kingdom)

1-Naphthylphthalamic acid (NPA) is a specific inhibitor of polar auxin transport that blocks carrier-mediated auxin efflux from plant cells. To allow identification of the NPA receptor thought to be...Full Text Available

1992-01-15

429

Value of micro-CT as an Investigative Tool for Osteochondritis Dissecans. A preliminary study with comparison to histology  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To evaluate micro computed tomography (micro-CT) for the assessment of osteochondritis dissecans in comparison with histology. Material and Methods: Osteochondritis dissecans lesions of 3 patients were evaluated using micro-CT (0.125 mA, 40 keV, 60 m slice thickness, 60 m isotropic resolution, entire sample) and light microscopy (toluidine blue, 3-5 m slice thickness). The methods were compared regarding preparation time, detectability of tissue types and morphologic features of bone and cartilage. Results: Non-destructive micro-CT imaging of the entire sample was faster than histologic preparation of a single slice for light microscopy. Morphologic features of bone and cartilage could be imaged in a comparable way to histology. It was not possible to image cells or different tissue types of bone and cartilage with micro-CT. Conclusion: Micro-CT is a fast, non-destructive tool that may be a supplement or, if detailed histologic ...

2003-09-01

430

Value of micro-CT as an Investigative Tool for Osteochondritis Dissecans. A preliminary study with comparison to histology  

International Nuclear Information System (INIS)

Purpose: To evaluate micro computed tomography (micro-CT) for the assessment of osteochondritis dissecans in comparison with histology. Material and Methods: Osteochondritis dissecans lesions of 3 patients were evaluated using micro-CT (0.125 mA, 40 keV, 60 m slice thickness, 60 m isotropic resolution, entire sample) and light microscopy (toluidine blue, 3-5 m slice thickness). The methods were compared regarding preparation time, detectability of tissue types and morphologic features of bone and cartilage. Results: Non-destructive micro-CT imaging of the entire sample was faster than histologic preparation of a single slice for light microscopy. Morphologic features of bone and cartilage could be imaged in a comparable way to histology. It was not possible to image cells or different tissue types of bone and cartilage with micro-CT. Conclusion: Micro-CT is a fast, non-destructive tool that may be a supplement or, if detailed histologic ...

2003-09-01

431

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

International Nuclear Information System (INIS)

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

2005-12-01

432

Surface Topography of 'Hotspot' Regions from a Single Cell SRF Cavity  

Energy Technology Data Exchange (ETDEWEB)

Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitatively low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed the crystal structure surrounding the pits via crystal phase orientation mapping, while 3D ...

2009-05-01

433

Sample preparation for nanoanalytical electron microscopy using the FIB lift-out method and low energy ion milling  

International Nuclear Information System (INIS)

Thinning specimens to electron transparency for electron microscopy analysis can be done by conventional (2-4 kV) argon ion milling or focused ion beam (FIB) lift-out techniques. Both these methods tend to leave 'mottling' visible on thin specimen areas, and this is believed to be surface damage caused by ion implantation and amorphisation. A low energy (250-500 V) Argon ion polish has been shown to greatly improve specimen quality for crystalline silicon samples. Here we investigate the preparation of technologically important materials for nanoanalysis using conventional and lift-out methods followed by a low energy polish in a GentleMill"T"M low energy ion mill. We use a low energy, low angle (6-8 deg.) ion beam to remove the surface damage from previous processing steps. We assess this method for the preparation of technologically important materials, such as steel, silicon and GaAs. For these materials the ability to create specimens from specific sites, and ...

2006-02-22

434

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

435

High resolution scanning electron microscopy of plasmodesmata.  

Science.gov (United States)

Symplastic transport occurs between neighbouring plant cells through functionally and structurally dynamic channels called plasmodesmata (PD). Relatively little is known about the composition of PD or the mechanisms that facilitate molecular transport into neighbouring cells. While transmission electron microscopy (TEM) provides 2-dimensional information about the structural components of PD, 3-dimensional information is difficult to extract from ultrathin sections. This study has exploited high-resolution scanning electron microscopy (HRSEM) to reveal the 3-dimensional morphology of PD in the cell walls of algae, ferns and higher plants. Varied patterns of PD were observed in the walls, ranging from uniformly distributed individual PD to discrete clusters. Occasionally the thick walls of the giant alga Chara were fractured, revealing the surface morphology of PD within. External structures such as spokes, spirals and mesh were observed ...

2011-05-28

436

Failure analysis of surface-micromachined microengines  

Energy Technology Data Exchange (ETDEWEB)

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

1998-11-01

437

Corrosion behaviour of molybdenum-implanted stainless steel  

Energy Technology Data Exchange (ETDEWEB)

A low-molybdenum austenitic stainless steel (UNS S30100) has been surface implanted with molybdenum ions, using various doses of 50 keV and 140 keV ions at room temperature. It is found that in aqueous sulphate/chloride solutions similar to the constitution of sea-waters the implantation does not affect the potentiostatically-determined critical pitting potential, but does change the density and morphology of corrosion pits. Pitting initiation after the addition of chloride at a fixed potential indicates little change in the time for measurable current increase, but the rate of increase of the current is much lower for implanted material. Detailed examination using optical microscopy, scanning electron microscopy, transmission electron microscopy and selected area diffraction suggests that the pits produced in implanted material are hemispherical with smooth covers of unattacked alloy. The use of half-implanted samples ...

1990-01-01

438

Corrosion behaviour of molybdenum-implanted stainless steel  

International Nuclear Information System (INIS)

A low-molybdenum austenitic stainless steel (UNS S30100) has been surface implanted with molybdenum ions, using various doses of 50 keV and 140 keV ions at room temperature. It is found that in aqueous sulphate/chloride solutions similar to the constitution of sea-waters the implantation does not affect the potentiostatically-determined critical pitting potential, but does change the density and morphology of corrosion pits. Pitting initiation after the addition of chloride at a fixed potential indicates little change in the time for measurable current increase, but the rate of increase of the current is much lower for implanted material. Detailed examination using optical microscopy, scanning electron microscopy, transmission electron microscopy and selected area diffraction suggests that the pits produced in implanted material are hemispherical with smooth covers of unattacked alloy. The use of half-implanted samples ...

1989-09-01

439

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

International Nuclear Information System (INIS)

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

2011-05-01

440

X-ray Microdiffraction and Strain Gradient Crystal Plasticity Studies of Geometrically Necessary Dislocations Near a Ni Bicrystal Grain Boundary  

Energy Technology Data Exchange (ETDEWEB)

We compare experimental measurements of inhomogeneous plastic deformation in a Ni bicrystal with crystal-plasticity simulations. Polychromatic X-ray microdiffraction, orientation imaging microscopy and scanning electron microscopy, were used to characterize the geometrically necessary dislocation distribution of the bicrystal after uniaxial tensile deformation. Changes in the local crystallographic orientations within the sample reflect its plastic response during the tensile test. Elastic strain in both grains increases near the grain boundary. Finite element simulations were used to understand the influence of initial grain orientation and structural inhomogeneities on the geometrically-necessary dislocations arrangement and distribution and to understand the underlying materials physics.

2009-01-01

441

Use of polarized light microscopy in porcine reproductive technologies  

British Library Electronic Table of Contents (United Kingdom)

The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) could be useful for a non-invasive evaluation of the meiotic spindle and may allow removal of nuclear structures without fluorochrome staining and ultraviolet exposure. In this study, PLM was used to assess its potential application in porcine reproductive technologies. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein in in vitro-matured porcine oocytes; to examine its effects on the oocyte developmental competence; to select oocytes based on the presence of the meiotic spindle detected by PLM; and to assess the efficiency oocyte enucleation assisted...

2011-01-01

442

Two-step template-free route for synthesis of TiO2 hollow spheres  

British Library Electronic Table of Contents (United Kingdom)

The TiO2 hollow microspheres were prepared by microwave-assisted solvothermal treatment without template. The morphology and the phase of TiO2 hollow microspheres were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and BET surface areas. The results show that the particles have hollow structures and the shell was covered by nanocrystals and have higher specific surface area. The possible formation mechanism of hollow TiO2 spherical structures has simply been proposed. The activity was evaluated by the photocatalytic degradation of methyl orange (MO). The results show that the particles having specific surface area show higher photocatalytic activity. It can be attribute to the doped ...

2011-01-01

443

Transmission electron microscopy characterization of laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft  

Energy Technology Data Exchange (ETDEWEB)

Microstructure characterization is important for controlling the quality of laser welding. In the present work, a detailed microstructure characterization by transmission electron microscopy was carried out on the laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft and an unambiguous identification of phases in the weldment was accomplished. It was found that there are {gamma}-FeCrNiC austenite solid solution dendrites as the matrix, (Nb, Ti) C type MC carbides, fine and dispersed Ni{sub 3} Al {gamma}' phase as well as Laves particles in the interdendritic region of the seam zone. A brief discussion was given for their existence based on both kinetic and thermodynamic principles.

2008-08-11

444

Transmission electron microscopy characterization of laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft  

International Nuclear Information System (INIS)

Microstructure characterization is important for controlling the quality of laser welding. In the present work, a detailed microstructure characterization by transmission electron microscopy was carried out on the laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft and an unambiguous identification of phases in the weldment was accomplished. It was found that there are #gamma#-FeCrNiC austenite solid solution dendrites as the matrix, (Nb, Ti) C type MC carbides, fine and dispersed Ni_3 Al #gamma#' phase as well as Laves particles in the interdendritic region of the seam zone. A brief discussion was given for their existence based on both kinetic and thermodynamic principles.

2008-08-11

445

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

International Nuclear Information System (INIS)

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

2005-11-20

446

Synthesis and enhanced light absorption of alumina matrix nanocomposites containing multilayer oxide nanorods and silver nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

In this paper, multilayer oxide nanorods were deposited in the nanopores of anodic aluminum oxide (AAO) via solution infiltration followed by heat treatment. The nanorods have a core-shell structure. First, the shell (nanotube) with the thickness of about 40nm was made of TiO"2 through the hydrolysis of (NH"4)"2TiF"6. Second, silver nanoparticles with the diameter of about 3nm were added into the TiO"2 layer through thermal decomposition of AgNO"3 at elevated temperatures. Then, cylindrical cores (nanorods) of CoO and ZnO with 200nm diameter were prepared, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and composition of the nanorods. UV-vis light absorption measurements in the wavelength range from 350 to...

2011-01-01

447

Synthesis and characterization of undoped and TM (Co, Mn) doped ZnO nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Antibacterial activity of Transition metals (Mn, Co) doped ZnO nanopowders prepared by a DC thermal plasma method against Escherichia coli and Staphylococcus aureus are investigated. The phase and morphology studies have been carried out by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. All the samples of the present investigation are found to have hexagonal wurtzite structure and crystallite sizes are found to vary from 25nm to 30nm. Our bacteriological study showed the enhanced antibacterial activity of transition metals doped ZnO nanoparticles than undoped ZnO indicating the great potential of ZnO nanoparticles in relevant clinical and biomedical applications.

2011-01-01

448

Quantitation of Cellular Dynamics in Growing Arabidopsis Roots with Light Sheet Microscopy  

CERN Document Server

To understand dynamic developmental processes, living tissues must be imaged frequently and for extended periods of time. Root development is extensively studied at cellular resolution to understand basic mechanisms underlying pattern formation and maintenance in plants. Unfortunately, ensuring continuous specimen access, while preserving physiological conditions and preventing photo-damage, poses major barriers to measurements of cellular dynamics in indeterminately growing organs such as plant roots. We present a system that integrates optical sectioning through light sheet fluorescence microscopy with hydroponic culture that enables us to image at cellular resolution a vertically growing Arabidopsis root every few minutes and for several consecutive days. We describe novel automated routines to track the root tip as it grows, track cellular nuclei and identify cell divisions. We demonstrate the system's capabilities by collecting data on divisions and nuclear ...

2011-01-01

449

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

British Library Electronic Table of Contents (United Kingdom)

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

2008-01-01

450

Preparation and Characterization of a Novel Polyamide Charged Mosaic Membrane  

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

451

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

British Library Electronic Table of Contents (United Kingdom)

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

2010-01-01

452

Photo-emission-electron-microscopy for characterization of an operating organic electronic device  

Energy Technology Data Exchange (ETDEWEB)

Photoemission-electron-microscopy (PEEM) is introduced as a tool for the characterization of organic electronic devices. PEEM-measurements are used for imaging as well as for spectroscopic analyses by illumination with light of a Hg-lamp (4.9 eV), a D2 lamp (7.3 eV), and with synchrotron radiation for resonant photoelectron spectroscopy. We determine the charge carrier concentration inside the channel region of the organic device and its lateral distribution. From resonant photoelectron spectroscopy (RPES) we deduce the electronic states which are accessible with the Hg and D2 illumination. Photoelectron-spectroscopy at selected areas ({mu}-PES) gives information on the absolute values of surface potentials in lateral resolution. We are able to perform these studies with applied voltages at the source- and drain-electrode.

2006-01-20

453

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

454

Nanostructured nickel ferrite: A liquid petroleum gas sensor  

British Library Electronic Table of Contents (United Kingdom)

The present investigation deals with the synthesis of nanostructured nickel ferrite (NiFe2O4) and their liquid petroleum gas-sensing characteristics. The 15-20nm size nickel ferrite has been synthesized at 700degreeC by a simple molten-salt route using sodium chloride as grain growth inhibitor. These nanoparticles exhibit significantly high response towards liquid petroleum gas (LPG) in comparison with ethanol vapor, hydrogen sulfide, ammonia and hydrogen. The gas response towards various gases at their 200ppm concentrations is investigated at 200-450degreeC. Different characterization techniques have been employed, such as differential thermal analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission elec...

2009-01-01

455

Morphology of the first instar of Calliphora vicina, Phormia regina and Lucilia illustris (Diptera, Calliphoridae)  

British Library Electronic Table of Contents (United Kingdom)

Abstract. Scanning electron microscopy documentation of first instar Calliphora vicina Robineau-Desvoidy, Phormia regina (Meigen) and Lucilia illustris (Meigen) (Diptera: Calliphoridae) is presented for the first time, and the following morphological structures are documented: pseudocephalon; antenna; maxillary palpus; facial mask; labial lobe; thoracic and abdominal spinulation; spiracular field; posterior spiracles, and anal pad. Light microscopy documentation and illustrations are provided for the cephaloskeleton in lateral and ventral views. New diagnostic features are revealed in the configuration of the facial mask, cephaloskeleton and posterior spiracles. The first instar morphology of C. vicina, Ph. regina and L. illustris is discussed in the light of existing knowledge about early...

2008-01-01

456

Microstructural characterization of plasma nitrided austenitic stainless steel  

Energy Technology Data Exchange (ETDEWEB)

The microstructure of the layers produced by plasma nitriding austenitic stainless steel at different treatment temperatures (400 and 500 C) were studied by transmission electron microscopy (TEM) together with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the microstructures were composed of 'expanded austenite' ({gamma}{sub N}) and {alpha}(ferrite)+CrN following plasma nitriding at lower and higher treatment temperatures, respectively. The former contains stacking faults and deformed twin substructures, while the latter is made up of colonies displaying a lamellar structure. Kurdjumov-Sachs or Nishiyama-Wassermann orientation relationships between the {alpha} and CrN layer were observed. (orig.)

2000-10-23

457

Microstructural aspects of the corrosion of Alloy 800  

International Nuclear Information System (INIS)

Transmission electron microscopy studies on solution-annealed Alloy 800 revealed small (100-200 nm), spherical-shaped titanium carbide (face centered cubic structure) and large (200 nm-5 #mu#m), faceted titanium nitride (hexagonal structure) particles randomly distributed in the austenite matrix. The volume fraction of former particles was found to be greater than that of the latter. Corrosion studies of the alloy in acidic, chlorides and acidic chloride environments at room temperature indicated that the passivity of Alloy 800 was adversely affected by the addition Cl"- ions. X-ray photoelectron spectroscopy revealed that the surface film formed on the alloy at the onset of passivity consisted of Cr"3"+ (as Cr_2O_3), without any Fe"3"+/Fe"2"+ or Ni"2"+. Scanning electron microscopy studies indicated initiation of pitting at large, faceted particles, not at small, spherical-shaped ones.

2004-12-01

458

Mechanical behavior of self-assembled carbon nanotube reinforced nylon 6,6 fibers  

British Library Electronic Table of Contents (United Kingdom)

The versatile electrospinning technique was used to successfully align and disperse multiwalled carbon nanotubes (MWCNT) in nylon 6,6 matrix to obtain composite fibers. The morphology of the composite fibers and the dispersion of the CNTs within the fibers were analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. TEM analysis revealed that the CNTs were well-dispersed, separated and aligned along the fiber axis. The thermal and mechanical properties of the composite fibers were characterized as a function of weight fraction of the CNTs. Incorporation of the CNTs in the fibers resulted in an increase in glass-transition temperature (Tg) by 7degreeC, indicating that the addition of CNTs has restricted the mobility of the polymer chains a...

2010-01-01

459

Influence of the strain-relaxation induced defect creation on the leakage current of embedded Si{sub 1-x}Ge{sub x} source/drain junctions  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to evaluate the role of the strain-relaxation processes on the leakage current of embedded SiGe S/D junctions. Current-voltage (I-V) and capacitance-voltage (C-V) characteristics were measured to further investigate the relaxation degree of embedded SiGe S/D junctions in the regime where partial relaxation by misfits dislocations is assumed, yielding a reduction of the leakage current density. Further, the impact of the ion implantation-related defects on the electrical performance is discussed. The analysis is complemented with structural characterization based on High Resolution Transmission Electron Microscopy (HRTEM) and Nomarski microscopy. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2009-08-15

460

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

International Nuclear Information System (INIS)

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

2010-08-02

461

In situ ultrahigh vacuum transmission electron microscopy studies of palladium silicide island formation on silicon (111) 7x7 surface  

International Nuclear Information System (INIS)

Pd was deposited onto Si (111) 7x7 surface at approximately 700 K inside an ultrahigh vacuum transmission electron microscope. Plan-viewed transmission electron microscopy (TEM) observation indicated that the islands have two kinds of shapes, round and rectangular (one-dimensional) ones. In a diffraction pattern for the rectangular islands, extra spots along the <110> direction of the Si surface, spacing of which is 1/8 times as long as that of Si (220) spots, were seen. A high resolution TEM image showed the corresponding superstructure in the rectangular islands. In situ observation of the growing process of the rectangular islands showed repeat of introduction and relief of strains during the growth, suggesting that such superstructure would be constructed by stacking compositionally different phases or introducing defects so that the periodically maximized strain is relieved.

2003-01-22

462

Improvement of the fatigue strength of AISI 4140 steel by an ion nitriding process  

Energy Technology Data Exchange (ETDEWEB)

The influence of plasma nitriding on the fatigue behaviour of AISI 4140 low-alloy steel was investigated under varying process conditions of temperature (500-600 C), time (1-12 h), heat treatment before ion nitriding (quenched and tempered, normalized) and gas mixture (50% H{sub 2}-50% N{sub 2}). A rotating bending fatigue machine was used to determine the fatigue strength. It was found that the plasma nitriding improves the fatigue strength and increases the fatigue limit depending on the surface hardness of the case depth. The microstructure of surface and diffusion layers was examined by optical microscopy. The fracture surface of specimens and the origin of fatigue cracks were observed by scanning electron microscopy.

1995-06-01

463

Hydriding properties of a mechanically milled Mg-50 wt.% ZrFe{sub 1.4}Cr{sub 0.6} composite  

Energy Technology Data Exchange (ETDEWEB)

The ball-milling method was used to produce Mg-50 wt.% ZrFe{sub 1.4}Cr{sub 0.6} composite. The thermodynamic, kinetic, and cycling properties, as well as the resistance to oxidation were examined. This composite possesses excellent kinetic properties, even at moderate temperature. Scanning electron microscopy, energy-dispersive spectrum, transmission electron microscopy and X-ray diffraction were used to characterize the composite before and after hydriding. The fine ZrFe{sub 1.4}Cr{sub 0.6} particles covering Mg particles acting as a ''catalytic film'', a significant amount of imperfections and some alloy powder in the Mg matrix introduced by ball milling all contributed to the enhanced absorption/desorption rate. (orig.)

2000-02-02

464

High speed inverted optical-resolution photoacoustic microscopy  

Science.gov (United States)

Photoacoustic microscopy (PAM) offers label-free, optical absorption contrast. A high-speed, high-resolution PAM system in an inverted microscope configuration with a laser pulse repetition rate of 100,000 Hz and a stationary ultrasonic transducer was built. Four-dimensional in vivo imaging of microcirculation in mouse skin was achieved at 18 three-dimensional volumes per second with repeated two-dimensional raster scans of 100 by 50 points. The corresponding twodimensional B-scan (50 A-lines) frame rate was 1800 Hz, and the one-dimensional A-scan rate was 90,000 Hz. The lateral resolution is 0.23+/-0.03 ?m for Au nano-wire imaging, which is 2.0 times below the diffraction limit.

2011-02-01

465

High resolution electron microscopy study of as-prepared and annealed tungsten-carbon multilayers  

International Nuclear Information System (INIS)

A series of sputtered tungsten-carbon multilayer structures with periods ranging from 2 to 12 nm in the as-prepared state and after annealing at 500 degrees C for 4 hours has been studied with high resolution transmission electron microscopy. The evolution with annealing of the microstructure of these multilayers depends on their period.As-prepared structures appear predominantly amorphous from TEM imaging and diffraction. Annealing results in crystallization of the W-rich layers into WC in the larger period samples, and less complete or no crystallization in the smaller period samples. X-ray scattering reveals that annealing expands the period in a systematic way. The layers remain remarkably well-defined after annealing under these conditions.

466

Heparin binding sites on Ross River virus revealed by electron cryo-microscopy  

International Nuclear Information System (INIS)

Cell surface glycosaminoglycans play important roles in cell adhesion and viral entry. Laboratory strains of two alphaviruses, Sindbis and Semliki Forest virus, have been shown to utilize heparan sulfate as an attachment receptor, whereas Ross River virus (RRV) does not significantly interact with it. However, a single amino acid substitution at residue 218 in the RRV E2 glycoprotein adapts the virus to heparan sulfate binding and expands the host range of the virus into chicken embryo fibroblasts. Structures of the RRV mutant, E2 N218R, and its complex with heparin were determined through the use of electron cryo-microscopy and image reconstruction methods. Heparin was found to bind at the distal end of the RRV spikes, in a region of the E2 glycoprotein that has been previously implicated in cell-receptor recognition and antibody binding.

2005-02-20

467

Extracellular matrix of plant callus tissue visualized by ESEM and SEM  

British Library Electronic Table of Contents (United Kingdom)

Actinidia deliciosa endosperm-derived callus culture is stable over a long period of culture. This system was used to investigate the ultrastructure of extracellular matrix occurring in morphogenic tissue. Specimens were prepared by different biological techniques (chemical fixation, liquid nitrogen fixation, glycerol substitution, critical-point drying, lyophilization) and observed by scanning electron microscopy (SEM). Fresh and wet samples were analyzed with the use of environmental scanning electron microscopy (ESEM). Extracellular matrix was observed on the surface of cell clusters as a membranous layer or reticulated network, shrunken or wrinkled, depending on the procedure. Generally, shrunken membranous layers with a globular appearance and fibrils were noted after critical-point d...

2010-01-01

468

Efficient elimination of sweetpotato little leaf phytoplasma from sweetpotato by cryotherapy of shoot tips  

British Library Electronic Table of Contents (United Kingdom)

Shoot tips with 3-4 leaf primordia were excised from in vitro-grown sweetpotato plants (Ipomoea batatas) infected with little leaf phytoplasma (Candidatus Phytoplasma aurantifolia) and subjected to cryotherapy. All plants regenerated from the cryo-treated shoot tips were free of phytoplasma, whereas shoot tip culture or dehydration of shoot tips without subsequent cryotherapy resulted in phytoplasma-free plants at a frequency of only 7-10%. Histological and ultrastructural studies with light and transmission electron microscopy, respectively, indicated that cryotherapy was lethal to all cells except those in the apical dome of the meristem and the two youngest leaf primordia. These surviving parts of the shoot tip contained vascular tissue and sieve elements, but electron microscopy showed...

2008-01-01

469

Effects of modification on microstructure and properties of ultrahigh carbon (1.9wt.% C) steel  

British Library Electronic Table of Contents (United Kingdom)

The effects of a modifier that contains Rare Earths (RE), low melting point alloy (Al-Bi-Sb) and Ca-Si alloy on an ultrahigh carbon steel containing 1.9wt.% C were studied. Microstructure characterization was carried out with optical microscopy (OM) and scanning electronic microscopy (SEM) combined with energy-dispersive spectrometry (EDS). Upon modification, the continuous eutectic carbide network structure was broken up and changed to a partly isolated and finer blocky structure in the as-cast alloy. Differential scanning calorimetry (DSC) revealed that the eutectoid temperature increased and the eutectic temperature decreased for the modified alloy. Modification also improved the impact toughness of the tempered steel, with a significant increase from 6.5 to 12.6Jcm^-^2, despite the har...

2011-01-01

470

Degradation of the corrosion resistance of anodic oxide films through immersion in the anodising electrolyte  

Energy Technology Data Exchange (ETDEWEB)

The deterioration of AA2024, AA6061 and AA7475 anodised in an environmentally-compliant tartaric acid/sulphuric acid electrolyte has been examined as a function of the immersion time in the electrolyte after termination of anodising. By transmission electron microscopy and scanning electron microscopy, degradation of the porous oxide film was qualitatively observed on AA2024. Electrochemical impedance spectroscopy revealed that AA2024 and AA7075 were more sensitive to prolonged immersion in the anodising electrolyte compared with AA6061, due to increased barrier layer thinning rates and increased susceptibility to localized corrosion. Salt spray tests confirmed the previous, indicating decay of anticorrosion performance for AA2024 and AA7075.

2010-07-15

471

Chemically produced nanostructured ODS-lanthanum oxide-tungsten composites sintered by spark plasma  

British Library Electronic Table of Contents (United Kingdom)

High purity W and W-0.9La2O3 (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous solutions. High resolution electron microscopy investigations revealed that the tungstate particles were coated with oxide precipitates. The precursor powder was reduced to tungsten metal with dispersed lanthanum oxide. Powders were consolidated by spark plasma sintering (SPS) at 1300 and 1400degreeC to suppress grain growth during sintering. The final grain size relates to the SPS conditions, i.e. temperature and heating rate, regardless of the starting powder particle size. Scanning electron microscopy revealed that oxide phases were mainly accumulated at grain boundaries while the tungsten matrix ...

2011-01-01

472

Chemical, electrical and electrochemical characterization of hybrid organic/inorganic polypyrrole/PW12O40^3^- coating deposited on polyester fabrics  

British Library Electronic Table of Contents (United Kingdom)

A study of the stability of conducting fabrics of polyester (PES) coated with polypyrrole/PW12O40^3^- (organic/inorganic hybrid material) in different pH solutions (1, 7, 13) has been done. Washing tests were also done in views of its possible application in electronic textiles such as antistatic clothing. X-ray photoelectron spectroscopy (XPS) studies have been done to quantify the amount of counter ion that remains in the polymer matrix and determine the doping ratio (N^+/N) after the different tests. Scanning electron microscopy (SEM) was also used to observe morphological differences after the different tests. Surface resistivity changes were measured by means of electrochemical impedance spectroscopy (EIS). Scanning electrochemical microscopy (SECM) was employed to measure changes in ...

2011-01-01

473

Biological and morphological characterization of human neonatal fibroblast cell culture B-HNF-1  

British Library Electronic Table of Contents (United Kingdom)

In the present study, human neonatal fibroblasts were isolated from a two-month-old human male. The purpose of the present investigation was the analysis of the morphology (light and transmission electron microscopy), karyotype and growth characteristics of the human neonatal fibroblast cell culture B-HNF-1. Moreover, STR typing and mitochondrial DNA amplification and sequencing was also performed. Analysis of chromosomes count showed that B-HNF-1 cell culture is diploid and has normal male karyotype 46, XY, which was stable during cultivation. The transmission electron microscopy demonstrated the ultra-structure of the B-HNF-1 cells; they have typical morphological features of proteosynthesis-active cells. Large number of fibroblasts bearing different shapes and surface characteristics ad...

2010-01-01

474

Automated motion estimation of root responses to sucrose in two Arabidopsis thaliana genotypes using confocal microscopy  

British Library Electronic Table of Contents (United Kingdom)

Root growth is a highly dynamic process influenced by genetic background and environment. This paper reports the development of R scripts that enable root growth kinematic analysis that complements a new motion analysis tool: PlantVis. Root growth of Arabidopsis thaliana expressing a plasma membrane targeted GFP (C24 and Columbia 35S:LTI6b-EGFP) was imaged using time-lapse confocal laser scanning microscopy. Displacement of individual pixels in the time-lapse sequences was estimated automatically by PlantVis, producing dense motion vector fields. R scripts were developed to extract kinematic growth parameters and report displacement to ?0.1 pixel. In contrast to other currently available tools, Plantvis-R delivered root velocity profiles without interpolation or averaging across the root s...

2011-01-01

475

Applications of environmental scanning electron microscopy (ESEM) in the study of novel drying latex films  

Energy Technology Data Exchange (ETDEWEB)

We have employed Environmental Scanning Electron Microscopy (ESEM) and Energy Dispersive X-ray (EDX) analysis to study the microstructural evolution of acrylic latex stabilised with a novel polysaccharide derived from agricultural waste. The analysis revealed that the micro structure of the latex in the 'wet' state consists of individual particles and clusters. Upon evaporation a discontinuous film is formed, with voids present within its structure, which is inconsistent with the conventional descriptions of film formation. Further ESEM examination of 'dry' specimens revealed that aging resulted in the formation of dendritic structures on the surfaces of the latex films, which EDX analysis confirmed to have been formed via crystallisation of salt. The experimental evidence suggests that the clusters, which are part of the structure of the latex, may act as nucleation centres that would allow the dendrites to form.

2008-08-15

476

Anisotropy of the structure and mechanical properties of low-alloy tungsten  

Energy Technology Data Exchange (ETDEWEB)

The authors examine the relationship of the structure and mechanical properties of similar alloys of tungsten with rhenium produced by the powder metallurgy method by sintering powders. Since the alloys were deformed by rolling, we examine the effect of the resultant anisotropy of the structure on the properties of the metal in various directions. The tests were conducted on an alloy of tungsten with 2 wt.% rhenium and, for comparison purposes, an alloy of tungsten with additions of oxides of yttrium and hafnium. The mechanical properties of the alloys, i.e., strength, cracking resistance, cold shortness temperature, were determined in the bend test. Structural examination was carried out using an optical microscope, electron scanning microscopy, and the method of transmission electron microscopy.

1987-12-01

477

Robotics and remote systems for hazardous environments  

International Nuclear Information System (INIS)

This is the first volume in a series of books to be published by Prentice Hall on Environmental and Intelligent Manufacturing Systems. The editors have assembled an interdisciplinary collection of authors from industry, government, and academia, that provide a broad range of expertise on robotics and remote systems. Readily accessible to practicing engineers, the book provides case studies and introduces new technology applicable to remote operations in unstructured and/or hazardous environments. Chapter 1 gives an overview of the US Environmental Protection Agency's efforts to apply robotic technology to assist in the operations at hazardous waste sites. The next chapter focuses on the theory and implementation of robust impedance control for robotic manipulators. Chapter 3 presents a discussion on the integration of failure tolerance into robotic systems. The next two chapters address the issue of sensory feedback and its indispensable role in remote and/or ...

478

Recent progress of the JAERI free electron laser driven by a compact superconducting RF linac  

International Nuclear Information System (INIS)

A prototype for a quasi-cw, and high-average power free electron laser (FEL) driven by a 15 MeV superconducting rf linac has been developed, and constructed at Tokai, JAERI since 1989. Cryogenic and accelerating fields' performances of four JAERI superconducting accelerator modules have been realized without any serious problem in the FEL accelerator vault and experimental hall. Since modification and related maintenance of the cryogenic refrigerator system for the driver were completed in the middle of October 1995, the system has run with no trouble, and the driver has been continuously run very successfully up to now. The optical resonator system and related electron beam transport system have been modified to realize larger acceptance than the old for both of the undulator radiation and energetic electron beam in 1995 Japanese fiscal year. In the modification, an alignment and distance measurement system has been newly developed, and successfully applied to ...

1997-02-28

479

Production and characterisation of the transition metal chalcogenides MoS[sub 2], MoSe[sub 2], WS[sub 2] and WSe[sub 2] as thin films in photovoltaics. Herstellung und Charakterisierung der Uebergangsmetallchalkogenide MoS[sub 2], MoSe[sub 2], WS[sub 2] und WSe[sub 2] als Duennfilme fuer die Photovoltaik  

Energy Technology Data Exchange (ETDEWEB)

The production and characterisation of thin films made from molybdenum sulphide, molybdenum selenide, tungsten sulphide and tungsten selenide are described. The electronic properties of the thin films were examined by Hall measurements and by thermal sensors. For the MoSe[sub 2] films, the majority of the samples were n-conducting and p-conduction was only found for a few examples. All the other films (MoS[sub 2], WS[sub 2], WSe[sub 2]) were p-conducting. The electrical transport properties of the thin films are comparable to those of single crystals. With these thin films as absorber materials, it was possible for the first time to produce the polycrystalline solid n-ZnO/p-MoSe[sub 2], n-ZnO/WSe[sub 2], n-ZnO/WS[sub 2]- and n-ITO/WS[sub 2] solar cells. In spite of not yet optimized diode geometry (lateral build-up), a maximum short circuit current of I[sub SC] = 18 mA/cm[sup 2] was achieved for the MoSe[sub 2] diode. (orig.)

1993-01-01

480

Influence of cobalt doping on the crystalline structure, optical and mechanical properties of ZnO thin films  

International Nuclear Information System (INIS)

Uniform and transparent thin films of Zn_1_-_xCo_xO (0 #=# 0.035, CoO (cubic) was detected as the secondary phase. Influence of Co addition on the volume fraction of grain boundaries has been interpreted. Increase in Co content in the range 0 #<=# x #<=# 0.10 led to quenching of near-band edge and blue emissions, decrease in band gap energy (E_g) from 3.36 eV to 3.26 eV, decrease in film thickness and refractive index and an increase in extinction coefficient of Zn_1_-_xCo_xO thin films. The change in nature of stress from compressive to tensile with lower to higher doping of Co is corroborative with the angular peak shift of (002) plane of ZnO lattice. An overall increase in microhardness of Zn_1_-_xCo_xO thin films up to x = 0.05 is attributed to change in microstructure and evolution of secondary phase and as the secondary phase separates out the overall stress is released leading to lowering of hardness after this concentration. Hall-Petch behavior is ...

2010-07-01

481

High-temperature ferromagnetism in laser-deposited layers of silicon and germanium doped with manganese or iron impurities  

Energy Technology Data Exchange (ETDEWEB)

The paper reports on the results of a study of the synthesis conditions effects on magnetic and transport properties of nanosized layers of high-T{sub c} diluted magnetic semiconductors (DMS), such as Ge:Mn, Si:Mn and Si:Fe, fabricated by laser-plasma deposition over a wide range of the growth temperature, T{sub g}=(20-550) deg. C on single-crystal GaAs or Al{sub 2}O{sub 3} substrates. Ferromagnetism of the layers was detected by measurement data of the magneto-optical Kerr effect, anomalous Hall effect, negative magnetoresistance and ferromagnetic resonance (FMR) at 5-500 K. The optimum growth temperature, T{sub g}, for Si:Mn/GaAs layers with T{sub c}{approx}400 K is shown to be about 400 deg. C. The Si:Mn/Al{sub 2}O{sub 3} layers with 35% of Mn have the metal-type of conductivity with manifestation of magnetization up to room temperature. Different types of uniformly doped structures and digital alloys have been investigated. In contrast to GaSb:Mn films, ...

2009-04-15

482

Forced and mixed convection heat transfer to supercritical CO{sub 2} vertically flowing in a uniformly-heated circular tube  

Science.gov (United States)

An experiment of heat transfer to CO{sub 2}, which flows upward and downward in a circular tube with an inner diameter of 6.32 mm, was carried out with mass flux of 285-1200 kg/m{sup 2} s and heat flux of 30-170 kW/m{sup 2} at pressures of 7.75 and 8.12 MPa, respectively. The corresponding Reynolds number at the tube test section inlet ranges from 1.8 x 10{sup 4} to 3.8 x 10{sup 5}. The tube inner diameter corresponds to the equivalent hydraulic diameter of the fuel assembly sub-channel, which is being studied at KAERI. Among the tested correlations, the Bishop correlation predicted the experimental data most accurately, but only 66.9% of normal heat transfer data were predicted within {+-}30% error range. The Watts and Chou correlation, which is claimed to be valid for both the normal and deteriorated heat transfer regime, showed unsatisfactory performance. A significant decrease in Nusselt number was observed in the range of 10{sup -6}

2010-11-15

483

Experimental Study of Hypernuclei Electroproduction by High Precision Spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Jlab experiment E01-011, carried out in 2005 in JLab Hall C, is the second generation of the hypernuclear spectroscopy experiments by the (e,e{prime}K{sup +}) reaction. The (e,e{prime}K{sup +}) reaction is complimentary to the associated production reactions (K{sup -},{pi}{sup -}), ({pi}{sup +},K{sup +}) since, due to a larger momentum transfer to a hyperon, excitations of both spin-non-flip and spin-flip states are possible. The experiment uses high quality and continuous primary electron beam to produce neutron rich hypernuclei on various targets by the electroproduction. The experimental setup consists of splitter magnet, high resolution kaon spectrometer (HKS) and electron spectrometer (Enge) implemented in new configuration, the so called 'Tilt Method'. Production data was taken on multiple targets: CH{sub 2}, {sup 6}Li, {sup 7}Li, {sup 9}Be, {sup 10}B, {sup 12}C and {sup 28}Si. In present study the analysis of CH{sub 2}, {sup 12}C and {sup ...

2009-12-01

484

Analysis and design of an ultra-high-temperature, hydrogen-fueled MHD generator as an open cycle power supply  

Energy Technology Data Exchange (ETDEWEB)

The theoretical analysis of a partially-ionized hydrogen gas flow (gas temperatures of approximately 10,000 to 20,000 K) through a particular class of magnetohydrodynamic (MHD) generators and the preliminary design of these MHD generators as open cycle, electric power supplies are performed. Analysis of the gas flow through these ultra-high temperature MHD generators requires a coupled gas dynamics/radiative heat transfer solution. Gas dynamics are modeled by a set of quasi-one-dimensional, nonlinear differential equations which account for friction, convective and radiative heat transfer and the interaction between the ionized gas and applied magnetic field. Radiative heat transfer is modeled using non-gray, absorbing-emitting two- and three-dimensional P-1 approximations which permit an arbitrary variation of the spectral absorption coefficient with frequency. Gas dynamics and radiative heat transfer are coupled through the energy equation, and through the temperature-and ...

1990-01-01

485

(Evaluation of the high intensity plasma sputer negative ion source and to test the response of the University of Tsukuba 13-MV tandem accelerator to mA intensity level pulsed mode heavy negative ion beams)  

Energy Technology Data Exchange (ETDEWEB)

A working visit was made to the National Laboratory for High Energy Physics, Tsukuba, Japan, during the time periods May 16, 1988--June 15, 1988 for the purposes of further evaluation of the high intensity plasma sputter negative ion source and to test the response of the University of Tsukuba 13-MV tandem accelerator to mA intensity level pulsed mode heavy negative ion beams. During the visit, the traveler worked in collaboration with Japanese scientists in installing and testing of the source on the University of Tsukuba tandem electrostatic accelerator injector. During the course of preliminary testing of the ion source and prior to actual injection into the accelerator, sparking began in one or more tube sections, which ultimately led to the decision to replace the damaged tube sections. This problem led to postponement of the scheduled tandem accelerator tests. The traveler attended the Seventh International Conference on Ion Implantation Technology held in the International ...

1988-07-06

486

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

International Nuclear Information System (INIS)

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

2003-09-15

487

Regulatory T cells inhibit stable contacts between CD4+ T cells and dendritic cells in vivo  

UK PubMed Central (United Kingdom)

Regulatory T (T reg) cells exert powerful down-modulatory effects on immune responses, but it is not known how they act in vivo. Using intravital two-photon laser scanning microscopy we determined that,...Full Text Available

2006-03-20

488

Quality engineering and control semiannual progress report November and December 1976 and January--April 1977  

International Nuclear Information System (INIS)

Research and development activities are reported on absorption spectroscopy, calorimetry, electrolysis, emission spectroscopy, fluorimetry gas chromatography, infrared spectroscopy, liquid chromatography, liquid scintillation counting, mass spectroscopy, microscopy, radiometric analysis, and thermal analysis. A group of miscellaneous projects are also described.

489

Plan-view transmission electron microscopy of crack tips in bulk materials  

Energy Technology Data Exchange (ETDEWEB)

A focused ion beam (FIB) system has been applied to prepare a thin foil specimen of Si, MgO and alumina which contained cracks in the plan of foil. It was possible to observe a much larger area at and near a crack tip than has been hitherto possible. FIB was also applied to observation of microstructure near a crack tip evolved during severe rolling contact fatigue in a steel.

1996-12-01

490

Phase-plate electron microscopy: a novel imaging tool to reveal close-to-life nano-structures  

UK PubMed Central (United Kingdom)

After slow progress in the efforts to develop phase plates for electron microscopes, functional phase plate using thin carbon film has been reported recently. It permits collecting high-contrast images...Full Text Available

2009-03-01

491

Nonformity of the electron density in amorphous silicon films  

Energy Technology Data Exchange (ETDEWEB)

The authors study the nonuniformity of a-Si:H films obtained by the method of vacuum condensation, with the help of x-ray small-angle scattering (SLS) and transmission electron microscopy. Films of hydrogenated amorphous silicon are greatest interest, because the electronic properties of this material can be controlled by doping. As a result of the compensation of the ruptured bonds, and possibly, effects of melting, the properties of such films are analogous to those of singlecrystalline silicon. XLS enables a quantitative determination of the prameters of the regions of low electron density (RLD) in such objects.

1985-12-01

492

Microstructural evolution in several casts of alloy 800 during creep tests  

International Nuclear Information System (INIS)

The creep behaviour of different casts of Alloy 800, supplied by different sources, has been determined in multispecimen furnaces at 650, 750 and 800"0C and at different stress levels up to about 14,000 hs; the environment was initially helium and then air. The microstructural investigations were carried out by transmission electron microscopy. (Auth.).

493

Micromachining using focused ion beams  

Energy Technology Data Exchange (ETDEWEB)

Focused ion beam (FIB) systems prove to be useful precision micromachining tools for a wide variety of applications. This micromachining technique includes scanning ion microscopy (SIM), micromachining by physical sputtering, and the ion-beam induced surface chemistry for etching and deposition. This technique is applied to image and modify IC's, to micromechanical applications, to modify the tip shape of tungsten emitters, and to prepare cross sections of selected regions for inspection in a transmission electron microscope (TEM). (orig.)

1994-11-16

494

Kinetics of low-temperature radiation hardening of metallic materials under irradiation  

British Library Electronic Table of Contents (United Kingdom)

A formula is obtained which describes the kinetics of low-temperature radiation hardening caused by creation of dislocation loops of interstitial type during irradiation. The radiation hardening of aluminum and vanadium is estimated using this formula and results of experiments on studying processes of nucleation and growth of interstitial dislocation loops in these materials by transparent electron microscopy. It is shown that the proposed formula is valid for description of the kinetics of low-temperature radiation hardening.

2011-01-01

495

Fouling Study of Silicon Oxide Pores Exposed to Tap Water  

Energy Technology Data Exchange (ETDEWEB)

We report on the fouling of Focused Ion Beam (FIB)-fabricated silicon oxide nanopores after exposure to tap water for two weeks. Pore clogging was monitored by Scanning Electron Microscopy (SEM) on both bare silicon oxide and chemically functionalized nanopores. While fouling occurred on hydrophilic silicon oxide pore walls, the hydrophobic nature of alkane chains prevented clogging on the chemically functionalized pore walls. These results have implications for nanopore sensing platform design.

2007-07-12

496

Dielectric barrier discharge using corona-modified silicone rubber  

Science.gov (United States)

Results from scanning electron microscopy, Fourier transform infrared spectroscopy and the measurement of thermally stimulated current show that a high density of the physical defects and the chemical defects are introduced into the surface of the silicone rubber plates after they are treated by corona discharge plasma. These defects behave electrically as shallow electron traps, leading to the formation of a uniform discharge in air at higher pressure when the corona-modified silicone rubber is used in dielectric barrier discharge.

2008-10-01

497

Clinical translation of ultraviolet autofluorescence microscopy towards endomicroscopy for early detection of cancer  

Science.gov (United States)

The non-invasiveness of autofluorescence technology may reduce sampling error and time delay for histopathology diagnosis. We establish biophotonic methods and guidelines to visualize and interpret early epithelial tissue changes that signify disease. Flexible and rigid fiber endomicroscopy instrumentation design parameters feasible for translation towards clinical use are in development.

2010-12-01

498

Biodegradability of polyurethane/polysaccharide blends  

Energy Technology Data Exchange (ETDEWEB)

Biodegradable polymers for use in environmental waste-management has been the subject of much discussion over the last few years. Polyurethane mixtures with polysaccharide (80/20 and 90/10 w/w ) have been prepared and films obtained. These films were inoculated, according to ASTM G22-76 rule and analysed by thermogravimetry and scanning electronic microscopy (SEM). The results are discussed in terms of thermal degradation and biodegradability. (author)

2001-07-01